A case of severe pneumonia caused by COVID-19 and secondary Lichtheimia ramosa infection in a diabetic patient undergoing hemodialysis

A case of severe pneumonia caused by COVID-19 and secondary Lichtheimia ramosa infection in a diabetic patient undergoing hemodialysis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report A case of severe pneumonia caused by COVID-19 and secondary Lichtheimia ramosa infection in a diabetic patient undergoing hemodialysis Juan Tian, Ruiguang Liu, Baojian Liu, Rui Ye, Lu Yang, Mou Yi, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7413088/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Purpose Mucormycosis caused by Lichtheimia ramosa (L. ramosa) is an opportunistic fungal infection that occurs more frequently in immunocompromised individuals. Case Presentation: We present the case of a 62-year-old man with diabetes mellitus, hypertension, and chronic kidney disease on regular hemodialysis. He was hospitalized for coronavirus disease 2019 (COVID-19) pneumonia and treated with broad-spectrum antibiotics and corticosteroids. Forty days later, the patient developed worsening hypoxemia requiring intensive care unit (ICU) transfer. Bronchoalveolar lavage fluid (BALF) culture was used to grow a fungal isolate, which was later confirmed as L. ramosa by next-generation sequencing (NGS). Despite antifungal therapy with liposomal amphotericin B, the patient progressed to multiorgan failure and died. Conclusion This study reports a case of severe pneumonia caused by secondary L. ramosa infection following COVID-19. The patient, who had comorbid diabetes mellitus and maintenance hemodialysis, presented with relatively rare clinical manifestations. NGS plays a pivotal role in rapidly identifying this secondary fungal infection, confirming the clinical utility of this technology in diagnosing rare opportunistic fungal infections in COVID-19 patients. Mucormycosis Lichtheimia ramosa COVID-19 Hemodialysis Case report Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Mucormycosis (CAM) ranks as the third most prevalent invasive fungal infection after candidiasis and aspergillosis. This life-threatening infection is caused by fungi of the order Mucorales , including genera such as Mucor , Rhizopus , and Lichtheimia . Human transmission typically occurs through three main routes: inhalation of spores, ingestion of contaminated substances, or direct cutaneous inoculation. CAM primarily affects immunocompromised individuals and progresses rapidly, with a reported mortality rate as high as 49%[ 1 ]. Global epidemiological surveillance data on CAM remain scarce, with reported incidence rates varying from 0.005 to 16 cases per million people across different regions during the past two decades [ 2 , 3 ]. The COVID-19 pandemic triggered a significant global increase in COVID-19-associated CAM cases. Significant geographical disparities exist, with developing nations demonstrating substantially higher disease burdens than industrialized countries do. An American study revealed that CAM patients require an average hospital stay of 17 days, with a mean total cost of $ 112,419 per admission and a mean daily cost of $ 4,096 [ 4 ]. Therefore, early diagnosis and prompt treatment are critically important for patient outcomes. CAM predominantly affects immunocompromised individuals with specific comorbidities. Major risk factors include uncontrolled diabetes mellitus (particularly with ketoacidosis or a hyperosmolar hyperglycemic state), hematological malignancies, solid organ or hematopoietic stem cell transplantation, prolonged corticosteroid therapy, iron overload syndrome, advanced HIV infection, and major burn injuries [ 5 ]. The prophylactic use of antifungal agents lacking Mucorales coverage (e.g., voriconazole) may further increase susceptibility. Healthcare-associated transmission occurs through contaminated medical devices (catheters, tongue depressors), wound care materials, and airborne exposure from compromised ventilation systems [ 6 ]. Early diagnosis of pulmonary CAM remains challenging because nonspecific radiological manifestations overlap with those of bacterial pneumonia or COVID-19-associated pulmonary injury. Conventional diagnostic methods (e.g., culture and histopathology) exhibit limited sensitivity, which is attributable to the fastidious growth requirements and tissue-invasive characteristics of these fungi. In this context, NGS demonstrates exceptional diagnostic performance, achieving 85%-100% accuracy [ 7 ], enabled by its high-throughput capacity and rapid turnaround time (24–48 hours) for comprehensive microbial identification. This technology enables precise speciation of Mucorales through targeted analysis of conserved genomic regions, including the 18S rRNA gene and internal transcribed spacer (ITS) sequences. Current clinical practice guidelines advocate a multimodal diagnostic approach that integrates NGS with galactomannan immunoassays and computed tomography (CT) imaging to optimize diagnostic accuracy, reflecting its increasing incorporation into standardized diagnostic protocols. While the global incidence of both aspergillosis and CAM continues to increase, L. ramosa is an exceptionally rare pulmonary pathogen within the Mucorales order, with only sporadic cases reported worldwide[ 8 , 9 ]. We present a case of severe pulmonary CAM caused by a secondary L. ramosa infection following SARS-CoV-2 infection in a patient with multiple comorbidities, including diabetes mellitus and chronic renal disease, who required regular hemodialysis. Case Presentation A 62-year-old male with a history of diabetes, hypertension, and chronic kidney disease was admitted to the neurosurgery department of a tertiary hospital in Guiyang, Guizhou Province, on December 31, 2022. The patient had COVID-19 exposure and tested positive on a self-administered antigen test. Despite taking oral ibuprofen, his symptoms persisted, including productive cough with yellow sputum, generalized myalgia, sore throat, orthopnea, and fever (peak temperature 39.1°C). Physical examination revealed Grade 1 tonsillar hypertrophy and bilateral coarse breath sounds. Hematological tests revealed a white blood cell (WBC) count of 6.29 × 10^9/L, a neutrophil percentage (NEUT%) of 79.4% (Fig. 1 ), a hemoglobin level of 82.0 g/L, a red blood cell (RBC) count of 3.28 × 10^12/L, and a blood platelet count of 151.0 × 10^9/L. Biochemical tests revealed a serum glucose level of 6.34 mmol/L, urea level of 33.58 mmol/L, creatine kinase level of 893 U/L, and creatinine level of 1358.50 µmol/L. Nasopharyngeal swab samples tested positive via real-time reverse transcription polymerase chain reaction (RT‒PCR) tests. CT findings revealed increased lung markings in both lungs, with bilateral patchy and ground-glass opacities. No enlarged lymph nodes were observed in the mediastinum. Bilateral pleural effusions are present (left effusion depth of approximately 42 mm), with adjacent pulmonary atelectasis (Fig. 2 a). The patient was preliminarily diagnosed with COVID-19 pneumonia, type 2 diabetes, secondary hypertension, and chronic renal failure. The patient was initially started on empirical anti-infective therapy consisting of cefoperazone-sulbactam (3.0 g intravenous [IV] q8h for 7 days), dexamethasone (6 mg IV qd for 7 days) and budesonide (1 mg via inhalation for 20 days). Management also included glucose-lowering agents (repaglinide/insulin), antihypertensive therapy (levamlodipine), anti-heart failure treatment with brain natriuretic peptide, and regular in-hospital hemodialysis. Three days after initiating treatment, antiviral therapy was supplemented with azvudine (5 mg orally once daily for 17 days). Despite continued treatment, the patient maintained persistent fever with poorly controlled pulmonary infection. Cytokine profiling revealed elevated levels of the following: interleukin-6 (IL-6): 33.6 pg/mL; interleukin-10 (IL-10): 22.9 pg/mL; and interferon-gamma (IFN-γ): 168.9 pg/mL. On Day 7, the antibiotic regimen was escalated to etimicin (0.3 g IV qd for 13 days) and meropenem (MEM) (1.0 g IV q8h for 13 days). Additionally, betamethasone (2 ml IV qd for 13 days) was administered as anti-inflammatory therapy. The patient was transferred to the nephrology department due to renal failure on day 20. The troponin level was 4.893 ng/mL, the WBC count was 3.39×109/L, the NEUT% was 88.60%, the erythrocyte sedimentation rate (ESR) was 91 mm/h, and the PCT level was 0.62 ng/ml. SARS-CoV-2 PCR testing returned negative results. Repeat chest CT imaging revealed the following: A) Mildly increased bilateral pulmonary markings. B) Bilateral patchy opacities showing predominantly ground-glass attenuation associated with interlobular septal thickening (manifesting as grid-like shadows). C) Radiographic progression is demonstrated by an increased extent of ground‒glass opacities and the development of new areas of involvement, which have worsened compared with those of the previous examination (Fig. 2 c). The patient was diagnosed with chronic renal failure (uremic stage), severe community-acquired pneumonia, and type 2 diabetes mellitus. Sputum cultures remained negative for bacterial growth. In light of elevated troponin levels (4.893 ng/mL) and ongoing clinical deterioration, vancomycin therapy (500 mg IV three times weekly for 19 days) was initiated to extend the coverage of gram-positive cocci. On day 29 of hospitalization, the course of corticosteroid therapy was completed, and treatment was de-escalated to ceftriaxone(CRO) (1 g IV daily). On day 33, the patient developed fever (38.7°C). Chest CT revealed the following: A) Bilateral mildly increased lung markings. B) Progressive patchy and ground-glass opacities. C) Asymmetric pleural changes (right-sided effusion progression and left-sided regression). D) Adjacent atelectasis (consistent with worsening pulmonary involvement) (Fig. 2 e). Despite persistently negative microbiological results: A) sputum cultures: No growth. B) Lipopolysaccharide (LPS): Negative. C) (1,3)-β-D-glucan assay (G-test): Negative. The clinical team initiated empirical escalation of therapy with piperacillin‒tazobactam (TZP) (4.5 g IV every 12 h for 5 days), fluconazole (Flu) (0.2 g IV once daily for 6 days), and methylprednisolone (20 mg IV once daily for 6 days) for suspected polymicrobial infection. On day 40, the patient developed acute respiratory failure complicating severe pneumonia, characterized by sudden onset of chest tightness, dyspnea, wheezing, orthopnea, and progressive hypoxemia. Arterial blood gas analysis revealed severe hypoxemia (SpO₂ 70%) with compensated respiratory alkalosis: pH 7.43, PaO₂ 55 mmHg, PaCO₂ 25.4 mmHg, HCO₃⁻ 17.2 mmol/L, and base excess − 6.3. Despite the severity of pulmonary infection suggested by these findings, the microbiological workup remained negative, including sputum cultures showing no growth, negative LPS, and a negative G test. In light of the clinical, radiological and microbiological discrepancy, antimicrobial therapy was intensified with MEM (1 g IVq8h for 2 days), Flu (0.4 g IV qd for 3 days) every 24 hours for 3 days, and TGC (100 mg IV) every 12 hours for 2 days. On day 42, the patient developed respiratory failure with severe hypoxemia (SpO₂ 62–80%), necessitating endotracheal intubation and mechanical ventilation. BALF was collected and sent for bacterial and fungal culture, as well as next-generation sequencing (NGS). Conventional cultures grew Pseudomonas aeruginosa (PA) and carbapenem-resistant Acinetobacter baumannii (CRAB), while NGS additionally identified L. ramosa , confirming fungal pneumonia. Antimicrobial therapy was initiated with TGC 100 mg IV every 12 hours for 2 days and ertapenem (ETP) 1 g IV once daily for 3 days. Antifungal treatment with amphotericin B cholesteryl sulfate complex (ABCS) was started on day 43 at 50 mg IV, with doses increasing to 100 mg on day 44 and 150 mg on day 45. On day 45, the patient’s chest CT image revealed the progression of preexisting bilateral pulmonary abnormalities, characterized by the following: A) Persistent disorganization of pulmonary vascular markings. B) Worsening ground-glass opacities and consolidations in the upper lobes and left lower lobe. C) Partial resolution of other pulmonary lesions (Fig. 2 g). In response to this ongoing clinical deterioration, polymyxin B (POL) 500,000 IU IV every 12 hours and TZP 3.75 g IV every 8 hours were added to the regimen. Unfortunately, the patient died from multiple organ dysfunction syndrome, and the temporal progression of clinical events is summarized in Fig. 3 . Microbiological and Molecular Identification of L. ramosa We performed comprehensive laboratory testing on the BALF, including smear microscopy, microbial culture, and next-generation sequencing (NGS). Gross inspection revealed that the sanguineous, cloudy, and thick in consistency (Fig. 4 a). Gram staining revealed slender, irregularly branched, nonsept hyphae under light microscopy (Fig. 4 b). Fluorescence staining further highlighted the hyphal structures alongside round sporangiospores (Fig. 4 c). The BALF was inoculated onto Sabouraud dextrose agar (SDA) and blood agar, followed by incubation at 35°C. After 3 days, large, cottony, white colonies with rapid growth were observed on SDA (Figs. 4 d, 4 e). Lactophenol cotton blue staining of the colonies revealed characteristic pear-shaped sporangia with prominent apophyses and sporangiospores, which is consistent with the morphology of L. ramosa (Fig. 4 f). The isolate was subcultured on SDA at 28°C for 5 days to obtain pure growth. DNA extraction was performed via the Fungal Genomic DNA Extraction Kit (Beijing Kinko's Biotechnology Co. Ltd.). PCR amplification of the ITS region was performed via the following universal primers: ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 (5′-TCCTCCGCTTATTGATATGC-3′). The 30 µL PCR mixture contained the following mixture: DNA template (1 µL), PCR mixture (15 µL), ITS1 primer (1 µL), ITS4 primer (1 µL), ddH₂O (12 µL), and PCR conditions: 94°C for 5 min (initial denaturation); 35 cycles of 94°C for 30 sec, 55°C for 30 sec, and 72°C for 1 min; 72°C for 7 min (final extension); and holding at -20°C. After analysis by agarose gel electrophoresis (2 µL sample + 6 µL bromophenol blue; 300 V, 12 min) (Supplementary Fig. 1A), the PCR products were sequenced (Beijing Prime Biotechnology Co., Ltd., Chengdu Branch). The isolate was identified as L. ramosa , exhibiting > 86% similarity with the type strains of this species in GenBank (Supplementary Fig. 1B). Antifungal Susceptibility Testing Antifungal susceptibility testing was conducted in strict accordance with the Clinical and Laboratory Standards Institute (CLSI) M60 guidelines. The detailed experimental procedure was as follows: Initially, the fungal suspension was adjusted to match the 0.5 McFarland standard turbidity using sterile saline. Subsequently, 100 µL of this standardized suspension was inoculated into 11 mL of RPMI 1640 liquid medium (pH adjusted to 7.0 ± 0.1 with MOPS buffer), thoroughly mixed, and then inoculated onto antifungal sensitivity plates that had been preimpregnated with gradient concentrations of antimicrobial agents. Two drug concentration ranges were used. Echinocandins (including micafungin, caspofungin, and anidulafungin) were tested at concentrations ranging from 0.008 to 4 µg/mL, and the results were read after 24 hours of incubation. Other antifungals, including amphotericin B, triazoles, and flucytosine, were tested at concentrations ranging from 0.031 to 16 µg/mL and incubated at 35 ± 1°C for 48 hours. Quality control was maintained throughout the experiment using standard reference strains ( Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258), with all control results falling within the CLSI-defined acceptable ranges. The susceptibility testing results demonstrated the following: the test strain exhibited good antifungal activity against amphotericin B, itraconazole, isavuconazole, and posaconazole. However, varying degrees of resistance were observed for triazoles (voriconazole and Flu) and echinocandins (micafungin, caspofungin, and anidulafungin). Additionally, significantly reduced antimicrobial activity was noted for the pyrimidine analog flucytosine (Table 1 ). Table 1 Antifungal drug susceptibility of Lichtheimia ramosa Antifungal drugs MIC(µg/ml) Interpretation according to CLSI M60 guidelines* Amphotericin B 1.00 Susceptible Itraconazole 0.25 Susceptible Voriconazole 8.00 Resistant Fluconazole 256.00 Resistant Isavuconazole 0.50 Susceptible Posaconazole 0.50 Susceptible Micafungin 8.00 Resistant Caspofungin 4.00 Resistant Anidulafungin 8.00 Resistant Fluorocytosine 32.00 Resistant *: Mucorales-specific epidemiological cutoff values (ECVs): amphotericin B ≤ 2 µg/mL, posaconazole ≤ 0.5 µg/mL, and isavuconazole≤ 1 µg/mL. Discussion We report a case of a patient with a history of diabetes who received regular hemodialysis and who was hospitalized due to SARS-CoV-2 infection. On day 42 after hospitalization, PA and CRAB were detected in the BALF, which was concurrently complicated by infection with L. ramosa , resulting in severe pneumonia. Similar cases of L. ramosa infection have been reported globally. In Iran, a 79-year-old diabetic female presented with COVID-19-associated rhino-orbital-cerebral CAM caused by L. ramosa [ 10 ]. In India, a low-birth-weight infant with cutaneous CAM developed from necrotizing fasciitis caused by L. ramosa [ 11 ]. A 3-year-old patient with hematologic malignancy in Sichuan, China, developed pulmonary CAM from L. ramosa infection[ 12 ]. A retrospective analysis of a 6-year-old child in Shanghai, China, who underwent chemotherapy for neuroblastoma developed rhinocerebral CAM due to L. ramosa [ 13 ]. A 65-year-old diabetic woman in Qingdao, China, presented with gastrointestinal CAM caused by L. Ramosa [ 14 ]. CAM caused by L. ramosa is reported less frequently than that caused by other Mucorales genera (e.g., Mucor, Rhizopus ). Therefore, this case adds to the limited body of literature and underscores the need for clinical vigilance regarding L. ramosa infection in patients with multiple risk factors, rather than suggesting it is a common occurrence. The patient in this case had multiple risk factors for CAM, including diabetes mellitus, regular hemodialysis, severe acute respiratory syndrome coronavirus 2 (SARS-CoV−2) infection, and the use of corticosteroids[ 15 , 16 ]. These factors collectively created an environment highly conducive to invasive fungal infection. Following SARS-CoV-2 infection, a repeat PCR test on day 19 of hospitalization was negative for the virus. However, the pulmonary infection persisted and progressed to severe pneumonia. This may be related to the damage to pulmonary epithelial cells caused by SARS-CoV-2 and the strong inflammatory response triggered by the cytokine storm, which increases the risk of fungal infection, which is consistent with previous research findings[ 17 ]. Additionally, the patient received corticosteroid anti-inflammatory treatment (including dexamethasone, betamethasone, and methylprednisolone) for up to 35 days. While corticosteroids can suppress pulmonary inflammatory responses, they concurrently increase the risk of infection with pathogens such as bacteria and fungi. Studies indicate that the use of corticosteroids for more than 3 weeks may significantly increase the risk of developing CAM[ 18 ]. Notably, this patient suffered from chronic renal failure and was on long-term hemodialysis. The occurrence of L. ramosa- induced severe pneumonia in hemodialysis patients is relatively uncommon. Research has shown that diabetic patients who are receiving long-term corticosteroid therapy and regular hemodialysis often present elevated serum iron levels. High iron concentrations can increase the pathogenicity of Mucorales fungi, accelerating their growth and hyphal development[ 19 ]. Severe pneumonia caused by L. ramosa CAM poses significant diagnostic challenges. The patient initially presented with nonspecific symptoms such as fever, cough, and sputum production. Moreover, characteristic imaging findings, including nodules, masses, consolidations, cavities, or reverse halo signs, were notably absent. Although clinicians suspected a fungal infection, diagnostic tests yielded negative results for both the serum G test and LPS. Furthermore, the patient showed no clinical improvement following empirical treatment with Flu. These factors collectively complicate the clinical diagnosis and management of this disease. Following admission to the ICU, BAL was performed. Microscopic examination of the BALF obtained via conventional culture revealed fungal structures morphologically consistent with L. ramosa , specifically pyriform sporangia and sporangiospores, suggesting a presumptive diagnosis of fungal infection. Subsequent NGS analysis of the BALF revealed L. ramosa , confirming the definitive diagnosis of pulmonary CAM due to L. ramosa . Consistent with most CAM infections, this case demonstrated nonspecific clinical manifestations, a lack of characteristic radiographic features, and a negative G test. These findings underscore that in this patient, BALF provided a superior diagnostic yield compared to sputum samples and highlight the utility of NGS as a valuable tool for the rapid and accurate identification of rare pathogens like L. ramosa in complex clinical scenarios.Therefore, in cases with high clinical suspicion but conventional negative tests, rapid and accurate pathogen identification is crucial for initiating appropriate early treatment. Antifungal susceptibility testing revealed that the L. ramosa isolate was susceptible to amphotericin B, itraconazole, isavuconazole, and posaconazole. On hospital day 43, antifungal therapy was initiated via ABCSs. The dosage was dynamically adjusted on the basis of the patient's clinical response and renal function. However, the patient's condition continued to deteriorate, and multiorgan dysfunction likely contributed to treatment failure and further complicated antifungal treatment. The management of L. ramosa -induced CAM requires a multidisciplinary approach, encompassing early diagnosis, aggressive antifungal therapy, and surgical intervention when necessary. Furthermore, relevant studies indicate that CAM may be transmitted via contaminated medical devices[ 6 ]. Therefore, proper handling of mucoralean pathogens within the hospital environment is crucial for preventing fungal infections. This study has certain limitations. Firstly, as the conclusions are based on a single case, the findings lack generalizability and cannot be readily extended to broader populations. Secondly, the definitive diagnosis of L. ramosa was established only at a late stage of the disease, which delayed targeted antifungal treatment and may have adversely affected the patient’s prognosis. Conclusion We report a fatal case of severe pneumonia caused by L. ramosa infection. This patient presented with multiple risk factors, including SARS-CoV-2 infection, diabetes mellitus, regular hemodialysis, and corticosteroid use. The clinical presentation and radiographic features were nonspecific, and both the G test and LPS test yielded negative results, rendering clinical recognition challenging. A definitive diagnosis of pulmonary CAM due to L. ramosa was established posthumously through cultivation of BALF and subsequent confirmation via NGS. Treatment with ABCS was initiated based on susceptibility results, but the patient's condition had already progressed to an irreversible stage, ultimately succumbing to multiorgan failure. This case highlights the diagnostic challenges and high mortality of L. ramosa infection in critically ill COVID-19 patients with comorbid conditions, underscoring the need for high clinical vigilance and early application of advanced diagnostic techniques such as NGS in this vulnerable population. Abbreviations CAM mucormycosis COVID-19 coronavirus disease 2019 BALF bronchoalveolar lavage fluid NGS next-generation sequencing WBC white blood cell RBC red blood cell RT‒PCR real-time reverse transcription polymerase chain reaction CT computed tomography CSL cefoperazone/sulbactam IL-6, interleukin-6 MEM meropenem Van vancomycin CRO ceftriaxone Flu fluconazole ICU intensive care unit TGC tigecycline PA Pseudomonas aeruginosa CRAB carbapenem-resistant Acinetobacter baumannii ETP ertapenem AMB amphotericin B POL polymyxin B TZP piperacillin‒tazobactam SDA Sabouraud Dextrose Agar CLSI Clinical and Laboratory Standards Institute, ABCS:amphotericin B cholesteryl sulfate complex Declarations Ethics approval and consent to participate This study was conducted in accordance with the Declaration of Helsinki and approved by the Medical Ethics Committee of The First People's Hospital of Guiyang (Approval No.: G2024-S022). Due to the retrospective nature of the study and the use of anonymized patient data, the requirement for informed consent was waived. Consent for publication Written informed consent for publication of this case report and any accompanying images was obtained from the patient's next-of-kin. The signed consent form is available for editorial review and has been provided as a supplementary submission file. Availability of Data and Materials The datasets generated during the current study are available in the GenBank repository under the temporary submission ID SUB0006711. The formal accession number will be assigned upon manuscript acceptance and the data will become publicly accessible upon publication. The accession number will be updated in the manuscript promptly once available. Competing Interests The authors declare that they have no competing interests. Funding This work was supported by grants from the Zhu Ke He Tong [2021]-43-25, Zhu Ke He Tong [2020]-10-6 and Zhu Ke He TongGCC[2023]030 from Science and Technology Department of Guiyang city of Guizhou Province, and the Science and Technology Plan Project of Sichuan Province (2024YFFK0049). The funders had no role in the design of the study; collection, analysis, or interpretation of data; writing of the manuscript; or decision to publish. Authors' contributions Juan Tian and Ruiguang Liu completed the manuscript writing, data analysis, and manuscript revision.Wang Yu conceptualized the manuscript framework and contributed to manuscript revision. Liu Baojian, Ye Rui, Mou Yi, and Yang Lu performed the laboratory testing. Li Jun conducted the analysis of imaging reports. All authors have reviewed and given final approval to the version submitted for publication, consented to its submission to the target journal, and agreed to be accountable for all aspects of the work. Acknowledgments The authors gratefully acknowledge the clinical, laboratory, and radiology departments of The First People’s Hospital of Guiyang for their technical and operational support. We also thank the patient’s family for their consent and cooperation. References Hoenigl M, Seidel D, Sprute R, et al. COVID-19-associated fungal infections. Nat Microbiol. 2022;7(8):1127–40. 10.1038/s41564-022-01172-2 . Almyroudi MP, Akinosoglou K, Rello J, et al. Clinical Phenotypes of COVID-19 Associated Mucormycosis (CAM): A Comprehensive Review. Diagnostics (Basel). 2022;12(12):3092. 10.3390/diagnostics12123092 . Skiada A, Drogari-Apiranthitou M, Pavleas I, et al. Global Cutaneous Mucormycosis: A Systematic Review. J Fungi (Basel). 2022;8(2):194. 10.3390/jof8020194 . Kontoyiannis DP, Yang H, Song J, et al. Prevalence, clinical and economic burden of mucormycosis-related hospitalizations in the United States: a retrospective study. BMC Infect Dis. 2016;16(1):730. 10.1186/s12879-016-2023-z . 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Curr Opin Infect Dis. 2023;36(6):427–35. 10.1097/QCO.0000000000000976 . Sharma A, Goel A. Mucormycosis: risk factors, diagnosis, treatments, and challenges during COVID-19 pandemic. Folia Microbiol (Praha). 2022;67(3):363–87. 10.1007/s12223-021-00934-5 . Upadhayay P, Bansal K, Goyal A, Epidemiology. Risk Factors, Diagnosis and Treatment of Mucormycosis (Black Fungus): A Review. Curr Pharm Biotechnol. 2023;24(13):1645–56. 10.2174/1389201024666230320111644 . Gupta I, Baranwal P, Singh G, Gupta V. Mucormycosis, past and present: a comprehensive review. Future Microbiol. 2023;18:217–34. 10.2217/fmb-2022-0141 . Abd El-Baky RM, Shady ER, Yahia R, et al. COVID-19 associated Mucormycosis among ICU patients: risk factors, control, and challenges. AMB Express. 2023;13(1):99. 10.1186/s13568-023-01599-8 . Huang SF, Wu AYJ, Lee SSJ, et al. COVID-19 associated mold infections: Review of COVID-19 associated pulmonary aspergillosis and mucormycosis. J Microbiol Immunol Infect. 2023;56(3):442–54. 10.1016/j.jmii.2022.12.004 . Additional Declarations No competing interests reported. Supplementary Files SupplementFig1.tiff Supplementary Fig. 1 Molecular identification of L. ramosa Notes: (a) Gel electrophoresis image of L. ramosa (markers from top to bottom: 5000 bp, 3000 bp, 2000 bp, 1000 bp, 750 bp, 500 bp, 250 bp, and 100 bp). (b) BLAST alignment of the ITS sequence of L. ramosa against GenBank database Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 31 Mar, 2026 Reviews received at journal 26 Mar, 2026 Reviewers agreed at journal 26 Mar, 2026 Reviewers agreed at journal 25 Mar, 2026 Reviews received at journal 13 Oct, 2025 Reviewers agreed at journal 30 Sep, 2025 Reviewers invited by journal 30 Sep, 2025 Editor assigned by journal 22 Sep, 2025 Editor invited by journal 08 Sep, 2025 Submission checks completed at journal 05 Sep, 2025 First submitted to journal 05 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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2","display":"","copyAsset":false,"role":"figure","size":656299,"visible":true,"origin":"","legend":"\u003cp\u003eChest computed tomography scans of a patient with \u003cem\u003eL. ramosa at \u003c/em\u003eadmission (a-g)\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-7413088/v1/7ef0b76591ef010eda1eab9d.png"},{"id":93540845,"identity":"c2f7d736-f8b5-4992-8545-23156dcb2662","added_by":"auto","created_at":"2025-10-15 02:24:25","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":538151,"visible":true,"origin":"","legend":"\u003cp\u003eTimeline of clinical events and interventions for the patient infected with\u003cem\u003e L. ramosa\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003eAbbreviations: ICU, intensive care unit; PCR, polymerase chain reaction; NGS, next-generation sequencing; BALF, bronchoalveolar lavage fluid; CRAB, carbapenem-resistant \u003cem\u003eAcinetobacter baumannii\u003c/em\u003e; PA, \u003cem\u003ePseudomonas aeruginosa\u003c/em\u003e; CSL, cefoperazone/sulbactam; MEM, meropenem; CRO, ceftriaxone; Van, vancomycin; Flu, fluconazole; TGC, tigecycline; ETP, ertapenem; AMB, amphotericin B; POL, polymyxin B; TZP, piperacillin/tazobactam.\u003c/p\u003e","description":"","filename":"Fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-7413088/v1/5904674eb9c4e228d952626e.png"},{"id":93540831,"identity":"8f605d7f-511a-4ac3-b6ff-0736e8d24191","added_by":"auto","created_at":"2025-10-15 02:24:24","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":705286,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Bloody and thick bronchoalveolar lavage fluid; (b) slender mycelium observed after Gram staining under a light microscope; (c) slender mycelium with round spores visible after fluorescence staining under a fluorescence microscope; (d \u0026amp; e) large white colonies observed in SDA medium; (f) pear-shaped sporangia seen after staining with lactophenol cotton blue staining under a light microscope.\u003c/p\u003e","description":"","filename":"Fig4.png","url":"https://assets-eu.researchsquare.com/files/rs-7413088/v1/7b642ee22e4d21f6b6fc0b21.png"},{"id":93541507,"identity":"761b7d81-1bbc-4a88-ade5-d787592de093","added_by":"auto","created_at":"2025-10-15 02:32:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2922294,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7413088/v1/ea54c753-7817-4847-abca-481bed3ff209.pdf"},{"id":93540787,"identity":"e3432445-fe31-4690-95e0-12c32549e7d1","added_by":"auto","created_at":"2025-10-15 02:24:19","extension":"tiff","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":6221172,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Fig. 1 Molecular identification of\u003cem\u003e L. ramosa\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eNotes: (a) Gel electrophoresis image of\u003cem\u003e L. ramosa\u003c/em\u003e (markers from top to bottom: 5000 bp, 3000 bp, 2000 bp, 1000 bp, 750 bp, 500 bp, 250 bp, and 100 bp). (b) BLAST alignment of the ITS sequence of L. ramosa against GenBank database\u003c/p\u003e","description":"","filename":"SupplementFig1.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7413088/v1/28f475d545b496015c2c4304.tiff"}],"financialInterests":"No competing interests reported.","formattedTitle":"A case of severe pneumonia caused by COVID-19 and secondary Lichtheimia ramosa infection in a diabetic patient undergoing hemodialysis","fulltext":[{"header":"Introduction","content":"\u003cp\u003eMucormycosis (CAM) ranks as the third most prevalent invasive fungal infection after candidiasis and aspergillosis. This life-threatening infection is caused by fungi of the order \u003cem\u003eMucorales\u003c/em\u003e, including genera such as \u003cem\u003eMucor\u003c/em\u003e, \u003cem\u003eRhizopus\u003c/em\u003e, and \u003cem\u003eLichtheimia\u003c/em\u003e. Human transmission typically occurs through three main routes: inhalation of spores, ingestion of contaminated substances, or direct cutaneous inoculation. CAM primarily affects immunocompromised individuals and progresses rapidly, with a reported mortality rate as high as 49%[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Global epidemiological surveillance data on CAM remain scarce, with reported incidence rates varying from 0.005 to 16 cases per million people across different regions during the past two decades [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. The COVID-19 pandemic triggered a significant global increase in COVID-19-associated CAM cases. Significant geographical disparities exist, with developing nations demonstrating substantially higher disease burdens than industrialized countries do. An American study revealed that CAM patients require an average hospital stay of 17 days, with a mean total cost of \u003cspan\u003e$\u003c/span\u003e112,419 per admission and a mean daily cost of \u003cspan\u003e$\u003c/span\u003e4,096 [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Therefore, early diagnosis and prompt treatment are critically important for patient outcomes.\u003c/p\u003e\u003cp\u003eCAM predominantly affects immunocompromised individuals with specific comorbidities. Major risk factors include uncontrolled diabetes mellitus (particularly with ketoacidosis or a hyperosmolar hyperglycemic state), hematological malignancies, solid organ or hematopoietic stem cell transplantation, prolonged corticosteroid therapy, iron overload syndrome, advanced HIV infection, and major burn injuries [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. The prophylactic use of antifungal agents lacking \u003cem\u003eMucorales\u003c/em\u003e coverage (e.g., voriconazole) may further increase susceptibility. Healthcare-associated transmission occurs through contaminated medical devices (catheters, tongue depressors), wound care materials, and airborne exposure from compromised ventilation systems [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eEarly diagnosis of pulmonary CAM remains challenging because nonspecific radiological manifestations overlap with those of bacterial pneumonia or COVID-19-associated pulmonary injury. Conventional diagnostic methods (e.g., culture and histopathology) exhibit limited sensitivity, which is attributable to the fastidious growth requirements and tissue-invasive characteristics of these fungi. In this context, NGS demonstrates exceptional diagnostic performance, achieving 85%-100% accuracy [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], enabled by its high-throughput capacity and rapid turnaround time (24\u0026ndash;48 hours) for comprehensive microbial identification. This technology enables precise speciation of \u003cem\u003eMucorales\u003c/em\u003e through targeted analysis of conserved genomic regions, including the 18S rRNA gene and internal transcribed spacer (ITS) sequences. Current clinical practice guidelines advocate a multimodal diagnostic approach that integrates NGS with galactomannan immunoassays and computed tomography (CT) imaging to optimize diagnostic accuracy, reflecting its increasing incorporation into standardized diagnostic protocols.\u003c/p\u003e\u003cp\u003eWhile the global incidence of both aspergillosis and CAM continues to increase, \u003cem\u003eL. ramosa\u003c/em\u003e is an exceptionally rare pulmonary pathogen within the \u003cem\u003eMucorales\u003c/em\u003e order, with only sporadic cases reported worldwide[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. We present a case of severe pulmonary CAM caused by a secondary \u003cem\u003eL. ramosa\u003c/em\u003e infection following SARS-CoV-2 infection in a patient with multiple comorbidities, including diabetes mellitus and chronic renal disease, who required regular hemodialysis.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eA 62-year-old male with a history of diabetes, hypertension, and chronic kidney disease was admitted to the neurosurgery department of a tertiary hospital in Guiyang, Guizhou Province, on December 31, 2022. The patient had COVID-19 exposure and tested positive on a self-administered antigen test. Despite taking oral ibuprofen, his symptoms persisted, including productive cough with yellow sputum, generalized myalgia, sore throat, orthopnea, and fever (peak temperature 39.1\u0026deg;C). Physical examination revealed Grade 1 tonsillar hypertrophy and bilateral coarse breath sounds. Hematological tests revealed a white blood cell (WBC) count of 6.29 \u0026times; 10^9/L, a neutrophil percentage (NEUT%) of 79.4% (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), a hemoglobin level of 82.0 g/L, a red blood cell (RBC) count of 3.28 \u0026times; 10^12/L, and a blood platelet count of 151.0 \u0026times; 10^9/L. Biochemical tests revealed a serum glucose level of 6.34 mmol/L, urea level of 33.58 mmol/L, creatine kinase level of 893 U/L, and creatinine level of 1358.50 \u0026micro;mol/L. Nasopharyngeal swab samples tested positive via real-time reverse transcription polymerase chain reaction (RT‒PCR) tests. CT findings revealed increased lung markings in both lungs, with bilateral patchy and ground-glass opacities. No enlarged lymph nodes were observed in the mediastinum. Bilateral pleural effusions are present (left effusion depth of approximately 42 mm), with adjacent pulmonary atelectasis (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea). The patient was preliminarily diagnosed with COVID-19 pneumonia, type 2 diabetes, secondary hypertension, and chronic renal failure. The patient was initially started on empirical anti-infective therapy consisting of cefoperazone-sulbactam (3.0 g intravenous [IV] q8h for 7 days), dexamethasone (6 mg IV qd for 7 days) and budesonide (1 mg via inhalation for 20 days). Management also included glucose-lowering agents (repaglinide/insulin), antihypertensive therapy (levamlodipine), anti-heart failure treatment with brain natriuretic peptide, and regular in-hospital hemodialysis. Three days after initiating treatment, antiviral therapy was supplemented with azvudine (5 mg orally once daily for 17 days). Despite continued treatment, the patient maintained persistent fever with poorly controlled pulmonary infection. Cytokine profiling revealed elevated levels of the following: interleukin-6 (IL-6): 33.6 pg/mL; interleukin-10 (IL-10): 22.9 pg/mL; and interferon-gamma (IFN-γ): 168.9 pg/mL. On Day 7, the antibiotic regimen was escalated to etimicin (0.3 g IV qd for 13 days) and meropenem (MEM) (1.0 g IV q8h for 13 days). Additionally, betamethasone (2 ml IV qd for 13 days) was administered as anti-inflammatory therapy.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe patient was transferred to the nephrology department due to renal failure on day 20. The troponin level was 4.893 ng/mL, the WBC count was 3.39\u0026times;109/L, the NEUT% was 88.60%, the erythrocyte sedimentation rate (ESR) was 91 mm/h, and the PCT level was 0.62 ng/ml. SARS-CoV-2 PCR testing returned negative results. Repeat chest CT imaging revealed the following: A) Mildly increased bilateral pulmonary markings. B) Bilateral patchy opacities showing predominantly ground-glass attenuation associated with interlobular septal thickening (manifesting as grid-like shadows). C) Radiographic progression is demonstrated by an increased extent of ground‒glass opacities and the development of new areas of involvement, which have worsened compared with those of the previous examination (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec). The patient was diagnosed with chronic renal failure (uremic stage), severe community-acquired pneumonia, and type 2 diabetes mellitus. Sputum cultures remained negative for bacterial growth. In light of elevated troponin levels (4.893 ng/mL) and ongoing clinical deterioration, vancomycin therapy (500 mg IV three times weekly for 19 days) was initiated to extend the coverage of gram-positive cocci. On day 29 of hospitalization, the course of corticosteroid therapy was completed, and treatment was de-escalated to ceftriaxone(CRO) (1 g IV daily). On day 33, the patient developed fever (38.7\u0026deg;C). Chest CT revealed the following: A) Bilateral mildly increased lung markings. B) Progressive patchy and ground-glass opacities. C) Asymmetric pleural changes (right-sided effusion progression and left-sided regression). D) Adjacent atelectasis (consistent with worsening pulmonary involvement) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee). Despite persistently negative microbiological results: A) sputum cultures: No growth. B) Lipopolysaccharide (LPS): Negative. C) (1,3)-β-D-glucan assay (G-test): Negative. The clinical team initiated empirical escalation of therapy with piperacillin‒tazobactam (TZP) (4.5 g IV every 12 h for 5 days), fluconazole (Flu) (0.2 g IV once daily for 6 days), and methylprednisolone (20 mg IV once daily for 6 days) for suspected polymicrobial infection.\u003c/p\u003e\u003cp\u003eOn day 40, the patient developed acute respiratory failure complicating severe pneumonia, characterized by sudden onset of chest tightness, dyspnea, wheezing, orthopnea, and progressive hypoxemia. Arterial blood gas analysis revealed severe hypoxemia (SpO₂ 70%) with compensated respiratory alkalosis: pH 7.43, PaO₂ 55 mmHg, PaCO₂ 25.4 mmHg, HCO₃⁻ 17.2 mmol/L, and base excess \u0026minus;\u0026thinsp;6.3. Despite the severity of pulmonary infection suggested by these findings, the microbiological workup remained negative, including sputum cultures showing no growth, negative LPS, and a negative G test. In light of the clinical, radiological and microbiological discrepancy, antimicrobial therapy was intensified with MEM (1 g IVq8h for 2 days), Flu (0.4 g IV qd for 3 days) every 24 hours for 3 days, and TGC (100 mg IV) every 12 hours for 2 days. On day 42, the patient developed respiratory failure with severe hypoxemia (SpO₂ 62\u0026ndash;80%), necessitating endotracheal intubation and mechanical ventilation. BALF was collected and sent for bacterial and fungal culture, as well as next-generation sequencing (NGS). Conventional cultures grew \u003cem\u003ePseudomonas aeruginosa\u003c/em\u003e (PA) and carbapenem-resistant \u003cem\u003eAcinetobacter baumannii\u003c/em\u003e (CRAB), while NGS additionally identified \u003cem\u003eL. ramosa\u003c/em\u003e, confirming fungal pneumonia. Antimicrobial therapy was initiated with TGC 100 mg IV every 12 hours for 2 days and ertapenem (ETP) 1 g IV once daily for 3 days. Antifungal treatment with amphotericin B cholesteryl sulfate complex (ABCS) was started on day 43 at 50 mg IV, with doses increasing to 100 mg on day 44 and 150 mg on day 45. On day 45, the patient\u0026rsquo;s chest CT image revealed the progression of preexisting bilateral pulmonary abnormalities, characterized by the following: A) Persistent disorganization of pulmonary vascular markings. B) Worsening ground-glass opacities and consolidations in the upper lobes and left lower lobe. C) Partial resolution of other pulmonary lesions (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eg). In response to this ongoing clinical deterioration, polymyxin B (POL) 500,000 IU IV every 12 hours and TZP 3.75 g IV every 8 hours were added to the regimen. Unfortunately, the patient died from multiple organ dysfunction syndrome, and the temporal progression of clinical events is summarized in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eMicrobiological and Molecular Identification of\u003c/b\u003e \u003cb\u003eL. ramosa\u003c/b\u003e\u003c/p\u003e\u003cp\u003eWe performed comprehensive laboratory testing on the BALF, including smear microscopy, microbial culture, and next-generation sequencing (NGS). Gross inspection revealed that the sanguineous, cloudy, and thick in consistency (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea). Gram staining revealed slender, irregularly branched, nonsept hyphae under light microscopy (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb). Fluorescence staining further highlighted the hyphal structures alongside round sporangiospores (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec). The BALF was inoculated onto Sabouraud dextrose agar (SDA) and blood agar, followed by incubation at 35\u0026deg;C. After 3 days, large, cottony, white colonies with rapid growth were observed on SDA (Figs.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ed, \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ee). Lactophenol cotton blue staining of the colonies revealed characteristic pear-shaped sporangia with prominent apophyses and sporangiospores, which is consistent with the morphology of \u003cem\u003eL. ramosa\u003c/em\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ef).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe isolate was subcultured on SDA at 28\u0026deg;C for 5 days to obtain pure growth. DNA extraction was performed via the Fungal Genomic DNA Extraction Kit (Beijing Kinko's Biotechnology Co. Ltd.). PCR amplification of the ITS region was performed via the following universal primers: ITS1 (5\u0026prime;-TCCGTAGGTGAACCTGCGG-3\u0026prime;) and ITS4 (5\u0026prime;-TCCTCCGCTTATTGATATGC-3\u0026prime;). The 30 \u0026micro;L PCR mixture contained the following mixture: DNA template (1 \u0026micro;L), PCR mixture (15 \u0026micro;L), ITS1 primer (1 \u0026micro;L), ITS4 primer (1 \u0026micro;L), ddH₂O (12 \u0026micro;L), and PCR conditions: 94\u0026deg;C for 5 min (initial denaturation); 35 cycles of 94\u0026deg;C for 30 sec, 55\u0026deg;C for 30 sec, and 72\u0026deg;C for 1 min; 72\u0026deg;C for 7 min (final extension); and holding at -20\u0026deg;C. After analysis by agarose gel electrophoresis (2 \u0026micro;L sample\u0026thinsp;+\u0026thinsp;6 \u0026micro;L bromophenol blue; 300 V, 12 min) (Supplementary Fig.\u0026nbsp;1A), the PCR products were sequenced (Beijing Prime Biotechnology Co., Ltd., Chengdu Branch). The isolate was identified as \u003cem\u003eL. ramosa\u003c/em\u003e, exhibiting\u0026thinsp;\u0026gt;\u0026thinsp;86% similarity with the type strains of this species in GenBank (Supplementary Fig.\u0026nbsp;1B).\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eAntifungal Susceptibility Testing\u003c/h2\u003e\u003cp\u003eAntifungal susceptibility testing was conducted in strict accordance with the Clinical and Laboratory Standards Institute (CLSI) M60 guidelines. The detailed experimental procedure was as follows: Initially, the fungal suspension was adjusted to match the 0.5 McFarland standard turbidity using sterile saline. Subsequently, 100 \u0026micro;L of this standardized suspension was inoculated into 11 mL of RPMI 1640 liquid medium (pH adjusted to 7.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1 with MOPS buffer), thoroughly mixed, and then inoculated onto antifungal sensitivity plates that had been preimpregnated with gradient concentrations of antimicrobial agents. Two drug concentration ranges were used. Echinocandins (including micafungin, caspofungin, and anidulafungin) were tested at concentrations ranging from 0.008 to 4 \u0026micro;g/mL, and the results were read after 24 hours of incubation. Other antifungals, including amphotericin B, triazoles, and flucytosine, were tested at concentrations ranging from 0.031 to 16 \u0026micro;g/mL and incubated at 35\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u0026deg;C for 48 hours. Quality control was maintained throughout the experiment using standard reference strains (\u003cem\u003eCandida parapsilosis\u003c/em\u003e ATCC 22019 and \u003cem\u003eCandida krusei\u003c/em\u003e ATCC 6258), with all control results falling within the CLSI-defined acceptable ranges. The susceptibility testing results demonstrated the following: the test strain exhibited good antifungal activity against amphotericin B, itraconazole, isavuconazole, and posaconazole. However, varying degrees of resistance were observed for triazoles (voriconazole and Flu) and echinocandins (micafungin, caspofungin, and anidulafungin). Additionally, significantly reduced antimicrobial activity was noted for the pyrimidine analog flucytosine (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eAntifungal drug susceptibility of Lichtheimia ramosa\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAntifungal drugs\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMIC(\u0026micro;g/ml)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eInterpretation according to CLSI M60 guidelines*\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAmphotericin B\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSusceptible\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eItraconazole\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSusceptible\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVoriconazole\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eResistant\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFluconazole\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e256.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eResistant\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIsavuconazole\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSusceptible\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePosaconazole\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSusceptible\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMicafungin\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eResistant\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCaspofungin\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eResistant\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAnidulafungin\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eResistant\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFluorocytosine\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e32.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eResistant\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e*: Mucorales-specific epidemiological cutoff values (ECVs): amphotericin B\u0026thinsp;\u0026le;\u0026thinsp;2 \u0026micro;g/mL, posaconazole\u0026thinsp;\u0026le;\u0026thinsp;0.5 \u0026micro;g/mL, and isavuconazole\u0026le;\u0026thinsp;1 \u0026micro;g/mL.\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eWe report a case of a patient with a history of diabetes who received regular hemodialysis and who was hospitalized due to SARS-CoV-2 infection. On day 42 after hospitalization, PA and CRAB were detected in the BALF, which was concurrently complicated by infection with \u003cem\u003eL. ramosa\u003c/em\u003e, resulting in severe pneumonia. Similar cases of \u003cem\u003eL. ramosa\u003c/em\u003e infection have been reported globally. In Iran, a 79-year-old diabetic female presented with COVID-19-associated rhino-orbital-cerebral CAM caused by \u003cem\u003eL. ramosa\u003c/em\u003e [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In India, a low-birth-weight infant with cutaneous CAM developed from necrotizing fasciitis caused by \u003cem\u003eL. ramosa\u003c/em\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. A 3-year-old patient with hematologic malignancy in Sichuan, China, developed pulmonary CAM from \u003cem\u003eL. ramosa\u003c/em\u003e infection[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. A retrospective analysis of a 6-year-old child in Shanghai, China, who underwent chemotherapy for neuroblastoma developed rhinocerebral CAM due to \u003cem\u003eL. ramosa\u003c/em\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. A 65-year-old diabetic woman in Qingdao, China, presented with gastrointestinal CAM caused by \u003cem\u003eL. Ramosa\u003c/em\u003e [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. CAM caused by \u003cem\u003eL. ramosa\u003c/em\u003e is reported less frequently than that caused by other Mucorales genera (e.g., \u003cem\u003eMucor, Rhizopus\u003c/em\u003e). Therefore, this case adds to the limited body of literature and underscores the need for clinical vigilance regarding L. ramosa infection in patients with multiple risk factors, rather than suggesting it is a common occurrence.\u003c/p\u003e\u003cp\u003eThe patient in this case had multiple risk factors for CAM, including diabetes mellitus, regular hemodialysis, severe acute respiratory syndrome coronavirus 2 (SARS-CoV\u0026minus;2) infection, and the use of corticosteroids[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. These factors collectively created an environment highly conducive to invasive fungal infection. Following SARS-CoV-2 infection, a repeat PCR test on day 19 of hospitalization was negative for the virus. However, the pulmonary infection persisted and progressed to severe pneumonia. This may be related to the damage to pulmonary epithelial cells caused by SARS-CoV-2 and the strong inflammatory response triggered by the cytokine storm, which increases the risk of fungal infection, which is consistent with previous research findings[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Additionally, the patient received corticosteroid anti-inflammatory treatment (including dexamethasone, betamethasone, and methylprednisolone) for up to 35 days. While corticosteroids can suppress pulmonary inflammatory responses, they concurrently increase the risk of infection with pathogens such as bacteria and fungi. Studies indicate that the use of corticosteroids for more than 3 weeks may significantly increase the risk of developing CAM[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Notably, this patient suffered from chronic renal failure and was on long-term hemodialysis. The occurrence of \u003cem\u003eL. ramosa-\u003c/em\u003einduced severe pneumonia in hemodialysis patients is relatively uncommon. Research has shown that diabetic patients who are receiving long-term corticosteroid therapy and regular hemodialysis often present elevated serum iron levels. High iron concentrations can increase the pathogenicity of \u003cem\u003eMucorales\u003c/em\u003e fungi, accelerating their growth and hyphal development[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eSevere pneumonia caused by \u003cem\u003eL. ramosa\u003c/em\u003e CAM poses significant diagnostic challenges. The patient initially presented with nonspecific symptoms such as fever, cough, and sputum production. Moreover, characteristic imaging findings, including nodules, masses, consolidations, cavities, or reverse halo signs, were notably absent. Although clinicians suspected a fungal infection, diagnostic tests yielded negative results for both the serum G test and LPS. Furthermore, the patient showed no clinical improvement following empirical treatment with Flu. These factors collectively complicate the clinical diagnosis and management of this disease. Following admission to the ICU, BAL was performed. Microscopic examination of the BALF obtained via conventional culture revealed fungal structures morphologically consistent with \u003cem\u003eL. ramosa\u003c/em\u003e, specifically pyriform sporangia and sporangiospores, suggesting a presumptive diagnosis of fungal infection. Subsequent NGS analysis of the BALF revealed \u003cem\u003eL. ramosa\u003c/em\u003e, confirming the definitive diagnosis of pulmonary CAM due to \u003cem\u003eL. ramosa\u003c/em\u003e. Consistent with most CAM infections, this case demonstrated nonspecific clinical manifestations, a lack of characteristic radiographic features, and a negative G test. These findings underscore that in this patient, BALF provided a superior diagnostic yield compared to sputum samples and highlight the utility of NGS as a valuable tool for the rapid and accurate identification of rare pathogens like L. ramosa in complex clinical scenarios.Therefore, in cases with high clinical suspicion but conventional negative tests, rapid and accurate pathogen identification is crucial for initiating appropriate early treatment.\u003c/p\u003e\u003cp\u003eAntifungal susceptibility testing revealed that the \u003cem\u003eL. ramosa\u003c/em\u003e isolate was susceptible to amphotericin B, itraconazole, isavuconazole, and posaconazole. On hospital day 43, antifungal therapy was initiated via ABCSs. The dosage was dynamically adjusted on the basis of the patient's clinical response and renal function. However, the patient's condition continued to deteriorate, and multiorgan dysfunction likely contributed to treatment failure and further complicated antifungal treatment.\u003c/p\u003e\u003cp\u003eThe management of \u003cem\u003eL. ramosa\u003c/em\u003e-induced CAM requires a multidisciplinary approach, encompassing early diagnosis, aggressive antifungal therapy, and surgical intervention when necessary. Furthermore, relevant studies indicate that CAM may be transmitted via contaminated medical devices[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Therefore, proper handling of mucoralean pathogens within the hospital environment is crucial for preventing fungal infections.\u003c/p\u003e\u003cp\u003eThis study has certain limitations. Firstly, as the conclusions are based on a single case, the findings lack generalizability and cannot be readily extended to broader populations. Secondly, the definitive diagnosis of L. ramosa was established only at a late stage of the disease, which delayed targeted antifungal treatment and may have adversely affected the patient\u0026rsquo;s prognosis.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eWe report a fatal case of severe pneumonia caused by \u003cem\u003eL. ramosa\u003c/em\u003e infection. This patient presented with multiple risk factors, including SARS-CoV-2 infection, diabetes mellitus, regular hemodialysis, and corticosteroid use. The clinical presentation and radiographic features were nonspecific, and both the G test and LPS test yielded negative results, rendering clinical recognition challenging. A definitive diagnosis of pulmonary CAM due to \u003cem\u003eL. ramosa\u003c/em\u003e was established posthumously through cultivation of BALF and subsequent confirmation via NGS. Treatment with ABCS was initiated based on susceptibility results, but the patient's condition had already progressed to an irreversible stage, ultimately succumbing to multiorgan failure. This case highlights the diagnostic challenges and high mortality of L. ramosa infection in critically ill COVID-19 patients with comorbid conditions, underscoring the need for high clinical vigilance and early application of advanced diagnostic techniques such as NGS in this vulnerable population.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCAM\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003emucormycosis\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCOVID-19\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ecoronavirus disease 2019\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eBALF\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ebronchoalveolar lavage fluid\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eNGS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003enext-generation sequencing\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eWBC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ewhite blood cell\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eRBC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ered blood cell\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eRT‒PCR\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ereal-time reverse transcription polymerase chain reaction\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCT\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ecomputed tomography\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCSL\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ecefoperazone/sulbactam\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIL-6, interleukin-6\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eMEM\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003emeropenem\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eVan\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003evancomycin\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCRO\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eceftriaxone\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eFlu\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003efluconazole\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eICU\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eintensive care unit\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eTGC\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003etigecycline\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003ePA\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003e\u003cem\u003ePseudomonas aeruginosa\u003c/em\u003e\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCRAB\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ecarbapenem-resistant \u003cem\u003eAcinetobacter baumannii\u003c/em\u003e\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eETP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eertapenem\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eAMB\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eamphotericin B\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003ePOL\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003epolymyxin B\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eTZP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003epiperacillin‒tazobactam\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eSDA\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eSabouraud Dextrose Agar\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCLSI\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eClinical and Laboratory Standards Institute, ABCS:amphotericin B cholesteryl sulfate complex\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was conducted in accordance with the Declaration of Helsinki and approved by the Medical Ethics Committee of The First People\u0026apos;s Hospital of Guiyang (Approval No.: G2024-S022). Due to the retrospective nature of the study and the use of anonymized patient data, the requirement for informed consent was waived.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent for publication of this case report and any accompanying images was obtained from the patient\u0026apos;s next-of-kin. The signed consent form is available for editorial review and has been provided as a supplementary submission file.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of Data and Materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated during the current study are available in the GenBank repository under the temporary submission ID SUB0006711. The formal accession number will be assigned upon manuscript acceptance and the data will become publicly accessible upon publication. The accession number will be updated in the manuscript promptly once available.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by grants from the Zhu Ke He Tong [2021]-43-25, Zhu Ke He Tong [2020]-10-6 and Zhu Ke He TongGCC[2023]030 from Science and Technology Department of Guiyang city of Guizhou Province, and the Science and Technology Plan Project of Sichuan Province (2024YFFK0049). The funders had no role in the design of the study; collection, analysis, or interpretation of data; writing of the manuscript; or decision to publish.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJuan Tian and Ruiguang Liu completed the manuscript writing, data analysis, and manuscript revision.Wang Yu conceptualized the manuscript framework and contributed to manuscript revision. Liu Baojian, Ye Rui, Mou Yi, and Yang Lu performed the laboratory testing. Li Jun conducted the analysis of imaging reports. All authors have reviewed and given final approval to the version submitted for publication, consented to its submission to the target journal, and agreed to be accountable for all aspects of the work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors gratefully acknowledge the clinical, laboratory, and radiology departments of The First People\u0026rsquo;s Hospital of Guiyang for their technical and operational support. We also thank the patient\u0026rsquo;s family for their consent and cooperation.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHoenigl M, Seidel D, Sprute R, et al. COVID-19-associated fungal infections. 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J Microbiol Immunol Infect. 2023;56(3):442\u0026ndash;54. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jmii.2022.12.004\u003c/span\u003e\u003cspan address=\"10.1016/j.jmii.2022.12.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pulmonary-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pulm","sideBox":"Learn more about [BMC Pulmonary Medicine](http://bmcpulmmed.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pulm/default.aspx","title":"BMC Pulmonary Medicine","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Mucormycosis, Lichtheimia ramosa, COVID-19, Hemodialysis, Case report","lastPublishedDoi":"10.21203/rs.3.rs-7413088/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7413088/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMucormycosis caused by \u003cem\u003eLichtheimia ramosa (L. ramosa)\u003c/em\u003e is an opportunistic fungal infection that occurs more frequently in immunocompromised individuals.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase Presentation:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe present the case of a 62-year-old man with diabetes mellitus, hypertension, and chronic kidney disease on regular hemodialysis. He was hospitalized for coronavirus disease 2019 (COVID-19) pneumonia and treated with broad-spectrum antibiotics and corticosteroids. Forty days later, the patient developed worsening hypoxemia requiring intensive care unit (ICU) transfer. Bronchoalveolar lavage fluid (BALF) culture was used to grow a fungal isolate, which was later confirmed as \u003cem\u003eL. ramosa\u003c/em\u003e by next-generation sequencing (NGS). Despite antifungal therapy with liposomal amphotericin B, the patient progressed to multiorgan failure and died.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study reports a case of severe pneumonia caused by secondary \u003cem\u003eL. ramosa\u003c/em\u003e infection following COVID-19. The patient, who had comorbid diabetes mellitus and maintenance hemodialysis, presented with relatively rare clinical manifestations. NGS plays a pivotal role in rapidly identifying this secondary fungal infection, confirming the clinical utility of this technology in diagnosing rare opportunistic fungal infections in COVID-19 patients.\u003c/p\u003e","manuscriptTitle":"A case of severe pneumonia caused by COVID-19 and secondary Lichtheimia ramosa infection in a diabetic patient undergoing hemodialysis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-15 02:23:59","doi":"10.21203/rs.3.rs-7413088/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-03-31T05:31:30+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-26T12:42:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"14532975143774552060515781875164285237","date":"2026-03-26T10:51:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"143053323231530501263777314809352409822","date":"2026-03-25T15:16:42+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-13T14:31:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"214854296240306582679273928149240341225","date":"2025-09-30T16:09:34+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-30T12:59:21+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-22T09:33:09+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-09-08T13:53:54+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-05T18:16:29+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pulmonary Medicine","date":"2025-09-05T18:13:18+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pulmonary-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pulm","sideBox":"Learn more about [BMC Pulmonary Medicine](http://bmcpulmmed.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pulm/default.aspx","title":"BMC Pulmonary Medicine","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"4f276b22-eb22-46d2-b68a-762c9c058a0d","owner":[],"postedDate":"October 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-10-15T02:23:59+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-15 02:23:59","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7413088","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7413088","identity":"rs-7413088","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}