Acanthamoeba-Induced LETM Mimicking NMOSD: A Rare Case Scenario

Acanthamoeba-Induced LETM Mimicking NMOSD: A Rare Case Scenario | 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 Acanthamoeba -Induced LETM Mimicking NMOSD: A Rare Case Scenario Remya Prakash, Aravind Reghukumar, Rammohan K, Jaichand Johnson, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8385294/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract We report a unique case of Acanthamoeba -induced longitudinally extensive transverse myelitis in a pregnant woman without classical epidemiologic risk factors. Cerebrospinal fluid (CSF) wet-mount microscopy and DNA PCR confirmed Acanthamoeba spp. Coinfections with Aspergillus spp. and tuberculous meningitis were also identified, highlighting the 'Trojan horse’ phenomenon. Parasitology Neurology Infectious Diseases Acanthamoeba longitudinally extensive transverse myelitis hypoglycorrhachia free-living amoebae NMOSD Aspergillus Mycobacterium FLA PCR wet mount trophozoite Trojan horse genetic melting pot Figures Figure 1 Figure 2 Figure 3 Introduction Free-living amoeba (FLA) are ubiquitous protozoa causing devastating central nervous system (CNS) infections. Naegleria fowleri infections manifest as fulminant primary amoebic meningoencephalitis (PAM) while Acanthamoeba and Balamuthia mandrillaris result in subacute/chronic CNS infections manifesting as granulomatous amoebic encephalitis (GAE), typically in immunocompromised individuals 1 .Though infarction of the spinal cord is documented, acanthamoebic myelitis is rare 2 . Longitudinally extensive transverse myelitis (LETM) has not yet been reported. We report a case of Acanthamoeba -induced LETM in a pregnant woman, masquerading as neuromyelitis optica spectrum disorder (NMOSD), complicated by co-infections. Case Presentation A 25-year-old primigravida (26 weeks of gestation) was referred to our obstetrics wing with a two-week history of progressive bilateral lower limb weakness. Initial MRI spine showed myelitis involving D2-D4 segments. Detailed etiologic evaluation was unyielding. With an initial diagnosis of seronegative NMOSD, she was treated with IV methylprednisolone and immunoglobulin. Other symptoms were limited to mild headaches. Despite treatment, weakness progressed (grade II to 0), and the patient developed bilateral papilledema and lateral rectus palsy. CSF study showed lymphocytic pleocytosis (92 cells/cmm), with normal glucose and protein (58 mg/dl and 48 mg/dl respectively). Four sessions of plasma exchange were done. Following fetal bradycardia, emergency LSCS was done at 34 weeks of gestation. In view of clinical deterioration despite immunomodulation, mild hypoglycorrhachia (CSF:Serum ratio 0.55) and elevated opening pressure (56 cm H2O); workup for infectious etiologies was repeated. MRI study of the brain and MR venogram were normal, while the spinal cord showed diffuse enlargement (from cervicomedullary junction to conus) with patchy enhancement (Fig. 1). CSF wet mount showed motile trophozoites (Fig. 2a), and DNA PCR tested positive for Acanthamoeba spp (Fig. 2b). Anti-amoebic therapy (amphotericin B, miltefosine, voriconazole, cotrimoxazole, and azithromycin) was initiated but later modified due to transaminitis. Subsequently; CSF culture grew Aspergillus (culture positive, species unidentified) and Mycobacterium tuberculosis (Fig. 3a, b). Intraventricular CSF Gene Xpert (CBNAAT) was also positive. Persistent elevated intracranial pressure (> 55 cm of H2O) necessitated external ventricular drain placement. Despite maximal support, including modified ATT and intraventricular amphotericin B, she succumbed 9 weeks after symptom onset She belonged to a rural household with access to borewell and municipal water supplies. She had a habit of dipping feet into a fish tank at home (fish spa) Other than that exposure to stagnant water or soil was lacking. PCR of a water sample from her house tested positive for Balamuthia and Paravahlkampfia spp. Discussion This case represents a novel presentation of Acanthamoeba infection as LETM in a pregnant woman, expanding the spectrum beyond GAE. The complex immune modulation in pregnancy, with controlled shift towards tolerance and TH2-like responses, increases susceptibility to opportunistic infections 3 . Although GAE has been reported in immunocompetent individuals also, disseminated disease and GAE is far more common in immunocompromised individuals, especially those with HIV, malnutrition, diabetes, kidney failure, cirrhosis, steroid use, chemotherapy, lymphoproliferative disorders, solid or bone marrow transplants, and agammaglobulinemia 1 . The diagnostic dilemma stemmed from the subacute onset and lymphocytic pleocytosis, with repeated CSF CBNAAT and autoimmune evaluations yielding negative results. The combination of fulminant intracranial pressure elevation, mild hypoglycorrhachia, and absence of an alternate etiology—features noted during the recent outbreak of Acanthamoeba CNS infections in Kerala, India—ultimately guided the diagnosis in this patient. Diagnostic Challenges Amoebic trophozoites are best appreciated on fresh, unfixed samples at room temperature and may be mistaken for macrophages 4 .Standard light microscopy lacks the resolution to clearly distinguish the spiculated appearance 5. .Amoebic load and trophozoite movements may also be variable, and repeated testing may be required 5 . Thus, microbiological identification of acanthamoeba is tedious in resource-limited settings. For our patient, the diagnosis was based on the species-specific 18S rRNA PCR method, developed by the molecular diagnostics division of The State Public Health Lab, Kerala, India. DNA extraction was performed using the Roche MagNA Pure automated nucleic acid extraction system and the amoebae were detected by single plex real-time TaqMan PCR; using the previously published primers and probes targeting the 18S rRNA gene for Acanthamoeba spp 6 . Naegleria fowleri 6 Balamuthia mandrillaris 6 Paravahlkampfia francinae 7 ; and Vermamoeba vermiformis 8 . Additionally, a newly designed TaqMan probe was used for Vermamoeba vermiformis . The concentrations of primers and probes were maintained as previously published, and assays amplified using Quant Studio 5 real time PCR system (Applied Biosystems). The primer used for acanthamoeba spp. was 18S_F 5’-CCC AGA TCG TTT ACC GTG AA-3’, Aca 18S_R 5’-TAA ATA TTA ATG CCC CCA ACT ATC C-3’ and probe was 18S_P 5’-FAM-CTG CCA CCG AAT ACA TTA GCA TGG-BHQ1-3’. Positive and negative controls were included in each run. Using this method, the presence of Acanthamoeba spp. was confirmed in our patient's CSF sample. Therapeutic Challenges The treatment of nervous system infections by Acanthamoeba spp. is also challenging due to endosymbiosis 9 . The endosymbionts include bacteria like Campylobacter jejuni, Escherichia coli, Legionella, Rickettsiales, Listeria , yeasts, giant viruses, algae, and protozoa 9 . There is evidence that Acanthamoeba can harbor atypical mycobacteria and even Mycobacterium tuberculosis 10 . Acanthamoeba can act as a “trojan horse” for microorganisms, which force their entry into amoebae, resist amoeba-mediated killing, and are hence protected by acanthamoeba’s ability to resist extreme temperatures, pH, and osmolarity 11,12 . Acanthamoeba is also used as a reservoir, and several organisms in environmental niches can multiply inside the trophozoites 12 . Failure to identify the Aspergillus species in our patient may be because it is unrepresented in the MALDI-TOF database due to its environmental origin. Acanthamoeba also exhibits a “genetic melting pot” phenomenon whereby exchange of genetic material between intracellular bacteria leads to the development of virulence traits 13 . The genome of intra-amoeba microorganisms is significantly larger than that of their relatives which also suggest this. 13 Public Health Challenges The patient's only documented water exposure was through fish-spa activities and household water use, without traditional high-risk behaviours such as swimming in warm freshwater bodies or exposure to contaminated soil. This profile indicates that epidemiologic links may be more diverse and ubiquitous than previously recognized. Early molecular testing for FLA should be integrated into diagnostic algorithms for atypical neurological presentations, especially in resource-limited settings where these amoebae may be more prevalent in water systems. Key Learning Points Having pleocytosis in the CSF does not necessarily indicate an inflammatory demyelinating disorder of the nervous system. Hypoglycorrhachia, refractory intracranial hypertension, and atypical natural history of the disease should prompt consideration of infectious etiologies. Clinicians should maintain high suspicion for free-living amoebae (FLA) in atypical neurological presentations, particularly in immunomodulated states. Molecular diagnostics are essential due to the low sensitivity of wet-mount microscopy. Importantly, exposure to stagnant water is not always necessary—household water sources may harbor FLA. Declarations DISCLOSURES The manuscript is original, and has been submitted to the Emerging Infectious Diseases; a publication of CDC ( manuscript number: EID-25-1853 ). We declare no conflicts of interest. Written informed consent was obtained from relative of the patient. Human Ethics Committee of Government Medical College Thiruvananthapuram, Kerala, India has approved the original study (HEC NO:27/16/2025/MCT) from which this data has been taken as specified in the protocol Use of AI tools : used Grammarly to check the grammar and improve readability. Informed consent for publication of this case report was obtained from the patient's husband following the patient's death. As the legal next of kin, the husband provided written consent for the use of clinical data and publication of this case. All efforts have been made to maintain patient confidentiality and anonymity. References Visvesvara GS, Moura H, Schuster FL (2007) Pathogenic and opportunistic free-living amoebae: Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri, and Sappinia diploidea. FEMS Immunol Med Microbiol 50(1):1–26. 10.1111/j.1574-695X.2007 00232.x Schumacher DJ, Tien RD, Lane K (2025) Neuroimaging findings in rare amebic infections of the central nervous system. Published online April 1, 1995. Accessed October 21. https://www.ajnr.org/content/16/4/930.long Narayan B, Nelson-Piercy C (2020) Physiological Changes of the Immune System During Pregnancy. 10.1007/978-3-030-43477-9_15 F MC GC (2025) Acanthamoeba spp. as agents of disease in humans. PubMed . Accessed November 16. https://pubmed.ncbi.nlm.nih.gov/12692099/ Laboratory Diagnosis of Primary Amoebic Meningoencephalitis | Laboratory Medicine | Oxford Academic. Accessed November 2 (2025) https://academic.oup.com/labmed/article/54/5/e124/6987229 Gs YQ, Aj da VRS (2025) S. Multiplex real-time PCR assay for simultaneous detection of Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri. PubMed . Accessed November 8. https://pubmed.ncbi.nlm.nih.gov/17021087/ Gs V et al (2025) R S, Y Q,. Paravahlkampfia francinae n. sp. masquerading as an agent of primary amoebic meningoencephalitis. PubMed . Accessed November 8. https://pubmed.ncbi.nlm.nih.gov/19602081/ Mw K, Rm V, Ba W, van der HBHSD (2025) K. Quantitative detection of the free-living amoeba Hartmannella vermiformis in surface water by using real-time PCR. PubMed . Accessed November 8. https://pubmed.ncbi.nlm.nih.gov/16957190/ Mungroo MR, Siddiqui R, Khan NA (2021) War of the microbial world: Acanthamoeba spp. interactions with microorganisms. Folia Microbiol (Praha) 66(5):689–699. 10.1007/s12223-021-00889-7 Looking in amoebae as a source of mycobacteria. 10.1016/j.micpath.2014.07.001 Barker J, Brown MRW (1994) Trojan Horses of the microbial world: protozoa and the survival of bacterial pathogens in the environment. Microbiology 140(6):1253–1259. 10.1099/00221287-140-6-1253 Siddiqui R, Khan NA (2012) Biology and pathogenesis of Acanthamoeba. Parasit Vectors 5(1):1–13. 10.1186/1756-3305-5-6 Moliner C, Fournier PE, Raoult D (2010) Genome analysis of microorganisms living in amoebae reveals a melting pot of evolution. FEMS Microbiol Rev 34(3):281–294. 10.1111/j.1574-6976.2009.00209.x Additional Declarations The authors declare potential competing interests as follows: We declare no conflicts of interest Supplementary Files SupplementaryTable.docx Fig 1: Timeline of Patient Care for Acanthamoeba-Induced LETM Cite Share Download PDF Status: Posted Version 1 posted 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8385294","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":561764997,"identity":"d8d63bb1-265d-4899-890e-c6134854dfe7","order_by":0,"name":"Remya Prakash","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9UlEQVRIiWNgGAWjYDADCQYGNoYPQAYbOylaGGeAtDCTooWZB8QipMW8vTtN4ueOe/KS7cefPbb5tU2ej5mB8cPHHNxaZM6c3SbZe6bYcDZPjrlxbt9twzZmBmbJmdvwuEcid5sEb1sC4zyGHDbp3J7bjEAtbMy8+LTIv90m+bctwX4e//Nn0pY9t+0Ja5Hg3SYNtCVxtkSCmTTDj9uJhLXw5G62lj2TkDxzxhszyd6G28ltzIzN+P3Cfnbjzbc7EmxnnE9/JvHjz23b+e3NBz98xKMFCFgkGBugTMY2MNmAUy0UMH9AqPlDSPEoGAWjYBSMRAAAZqZN8oK2pGoAAAAASUVORK5CYII=","orcid":"","institution":"Government Medical College,Thiruvananthapuram","correspondingAuthor":true,"prefix":"","firstName":"Remya","middleName":"","lastName":"Prakash","suffix":""},{"id":561764998,"identity":"b8457410-f63d-4238-a05a-81beffde6dd0","order_by":1,"name":"Aravind Reghukumar","email":"","orcid":"","institution":"Government Medical College,Thiruvananthapuram","correspondingAuthor":false,"prefix":"","firstName":"Aravind","middleName":"","lastName":"Reghukumar","suffix":""},{"id":561764999,"identity":"a6f2e658-98e2-4aa0-a97b-4700a4881cbd","order_by":2,"name":"Rammohan K","email":"","orcid":"","institution":"Government Medical College,Thiruvananthapuram","correspondingAuthor":false,"prefix":"","firstName":"Rammohan","middleName":"","lastName":"K","suffix":""},{"id":561765000,"identity":"ac17da9a-3ab1-4c8a-a706-137b5caf38e0","order_by":3,"name":"Jaichand Johnson","email":"","orcid":"","institution":"State Clinical and Public Health Lab","correspondingAuthor":false,"prefix":"","firstName":"Jaichand","middleName":"","lastName":"Johnson","suffix":""},{"id":561765001,"identity":"b6a0dee1-1bdd-489e-ba62-a10ce4111df2","order_by":4,"name":"Swapna R.Nath","email":"","orcid":"","institution":"Regional Cancer Centre,Thiruvananthapuram","correspondingAuthor":false,"prefix":"","firstName":"Swapna","middleName":"","lastName":"R.Nath","suffix":""},{"id":561765002,"identity":"aad3c1b4-e9ea-46e7-bb9e-15e5c66c740a","order_by":5,"name":"Saritha Narayanankutty","email":"","orcid":"","institution":"Government Medical College,Thiruvananthapuram","correspondingAuthor":false,"prefix":"","firstName":"Saritha","middleName":"","lastName":"Narayanankutty","suffix":""},{"id":561765003,"identity":"e14944aa-0155-4a31-831b-5b19e9e3bcee","order_by":6,"name":"Chithra Latha Raveendran","email":"","orcid":"","institution":"Intermediate Reference Laboratory for TB,State TB cell","correspondingAuthor":false,"prefix":"","firstName":"Chithra","middleName":"Latha","lastName":"Raveendran","suffix":""},{"id":561765004,"identity":"edfd403f-5fbc-4d5e-b27a-47d119c7803b","order_by":7,"name":"Jyothy Rajahamsan","email":"","orcid":"","institution":"Government Medical College,Thiruvananthapuram","correspondingAuthor":false,"prefix":"","firstName":"Jyothy","middleName":"","lastName":"Rajahamsan","suffix":""},{"id":561765005,"identity":"0c196329-9ce1-4823-af0e-9b9038ef718d","order_by":8,"name":"Sharmad M.S.","email":"","orcid":"","institution":"Government Medical College,Thiruvananthapuram","correspondingAuthor":false,"prefix":"","firstName":"Sharmad","middleName":"","lastName":"M.S.","suffix":""},{"id":561765006,"identity":"bde4ece8-2511-440d-b72e-8a50de85f163","order_by":9,"name":"Anil Sathyadas","email":"","orcid":"","institution":"Government Medical College,Thiruvananthapuram","correspondingAuthor":false,"prefix":"","firstName":"Anil","middleName":"","lastName":"Sathyadas","suffix":""},{"id":561765007,"identity":"323fc49c-2d43-4129-a896-45227c88fe6f","order_by":10,"name":"Anoop P","email":"","orcid":"","institution":"Government Medical College,Thiruvananthapuram","correspondingAuthor":false,"prefix":"","firstName":"Anoop","middleName":"","lastName":"P","suffix":""},{"id":561765008,"identity":"0903112f-1a48-462c-b649-de1fd5f5d948","order_by":11,"name":"Deepthi Somarajan","email":"","orcid":"","institution":"Government Medical College,Thiruvananthapuram","correspondingAuthor":false,"prefix":"","firstName":"Deepthi","middleName":"","lastName":"Somarajan","suffix":""},{"id":561765009,"identity":"b19cb9fd-e44e-4c0d-941a-ea4e7f11d342","order_by":12,"name":"Fida Ali","email":"","orcid":"","institution":"Government Medical College,Thiruvananthapuram","correspondingAuthor":false,"prefix":"","firstName":"Fida","middleName":"","lastName":"Ali","suffix":""}],"badges":[],"createdAt":"2025-12-17 11:44:50","currentVersionCode":1,"declarations":{"humanSubjects":true,"vertebrateSubjects":false,"conflictsOfInterestStatement":true,"humanSubjectEthicalGuidelines":true,"humanSubjectConsent":true,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-8385294/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8385294/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":98780604,"identity":"3aa3a007-afec-4dec-9dbb-b24f4920cfbd","added_by":"auto","created_at":"2025-12-22 12:31:30","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2293118,"visible":true,"origin":"","legend":"","description":"","filename":"DRAFT.docx","url":"https://assets-eu.researchsquare.com/files/rs-8385294/v1/4c5fec1acdfdf0efa41bae77.docx"},{"id":98779272,"identity":"60585045-59a1-42c2-bdab-d73dfbca9c16","added_by":"auto","created_at":"2025-12-22 12:30:08","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":342,"visible":true,"origin":"","legend":"","description":"","filename":"rs8385294.json","url":"https://assets-eu.researchsquare.com/files/rs-8385294/v1/5ab20b993559a14811e8960f.json"},{"id":98763944,"identity":"e82d9ba8-4eaf-40f2-898c-98392c5b50e5","added_by":"auto","created_at":"2025-12-22 10:07:26","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":30493,"visible":true,"origin":"","legend":"","description":"","filename":"rs83852940enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-8385294/v1/c3e6024bb7d5b0b5bd08d750.xml"},{"id":98779523,"identity":"f1e0459e-c181-47ae-ba8b-e07b78cdd615","added_by":"auto","created_at":"2025-12-22 12:30:26","extension":"xml","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":29396,"visible":true,"origin":"","legend":"","description":"","filename":"rs83852940structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8385294/v1/b932bf98d9f598fe4531ed8d.xml"},{"id":98763942,"identity":"cbfdbd84-035e-462a-9b33-40dba84baa70","added_by":"auto","created_at":"2025-12-22 10:07:26","extension":"html","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":35590,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8385294/v1/beeb693864cef555bc7943b7.html"},{"id":98779261,"identity":"905c4207-03f1-412a-837e-8a12432c8337","added_by":"auto","created_at":"2025-12-22 12:30:06","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":55339,"visible":true,"origin":"","legend":"\u003cp\u003eMRI of the whole spine: T2-weighted sequence; sagittal section showing LETM\u003c/p\u003e","description":"","filename":"Fig1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8385294/v1/0eac746787101179ae7470f4.jpg"},{"id":98763937,"identity":"278c50bd-01ee-431d-a2f3-0e6f8ef6be31","added_by":"auto","created_at":"2025-12-22 10:07:26","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":243738,"visible":true,"origin":"","legend":"\u003cp\u003ea: Wet-mount microscopy showing motile trophozoites with spiculated appearance\u003c/p\u003e\n\u003cp\u003eb: Real-time PCR amplification plot showing differential detection of and other free-living amoeba species\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-8385294/v1/2f46adddf76c8ae6156dcae7.png"},{"id":98763938,"identity":"ec25ab10-be3c-4a1a-a65c-10481dc96255","added_by":"auto","created_at":"2025-12-22 10:07:26","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":50294,"visible":true,"origin":"","legend":"\u003cp\u003ea: Lactophenol Cotton Blue (LCB) mount showing septate hyphae with conidiophores, vesicles, phialides and chains of conidia consistent with the morphology of Aspergillus species.\u003c/p\u003e\n\u003cp\u003eb: MGIT fluorescence-based culture system showing positivity, indicating mycobacterial growth.\u003c/p\u003e","description":"","filename":"Fig3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8385294/v1/f670643906ec9b74da68c4f5.jpg"},{"id":98783570,"identity":"db7b5f8f-c066-41b6-a059-ebf38e16c008","added_by":"auto","created_at":"2025-12-22 12:42:15","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":657759,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8385294/v1/82c29e30-913f-4aed-8386-08b3d056ea90.pdf"},{"id":98778823,"identity":"9150bad3-2931-4368-9cb7-5c678ddb3d37","added_by":"auto","created_at":"2025-12-22 12:29:41","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":154869,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFig 1: Timeline of Patient Care for Acanthamoeba-Induced LETM\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"SupplementaryTable.docx","url":"https://assets-eu.researchsquare.com/files/rs-8385294/v1/b0de599199dfc0b485e1afe6.docx"}],"financialInterests":"The authors declare potential competing interests as follows: We declare no conflicts of interest","formattedTitle":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eAcanthamoeba\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e-Induced LETM Mimicking NMOSD: A Rare Case Scenario\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eFree-living amoeba (FLA) are ubiquitous protozoa causing devastating central nervous system (CNS) infections. \u003cem\u003eNaegleria fowleri\u003c/em\u003e infections manifest as fulminant primary amoebic meningoencephalitis (PAM) while \u003cem\u003eAcanthamoeba\u003c/em\u003e and \u003cem\u003eBalamuthia mandrillaris\u003c/em\u003e result in subacute/chronic CNS infections manifesting as granulomatous amoebic encephalitis (GAE), typically in immunocompromised individuals\u003csup\u003e1\u003c/sup\u003e.Though infarction of the spinal cord is documented, acanthamoebic myelitis is rare\u003csup\u003e2\u003c/sup\u003e. Longitudinally extensive transverse myelitis (LETM) has not yet been reported.\u003c/p\u003e\n\u003cp\u003eWe report a case of \u003cem\u003eAcanthamoeba\u003c/em\u003e-induced LETM in a pregnant woman, masquerading as neuromyelitis optica spectrum disorder (NMOSD), complicated by co-infections.\u0026nbsp;\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eA 25-year-old primigravida (26 weeks of gestation) was referred to our obstetrics wing with a two-week history of progressive bilateral lower limb weakness. Initial MRI spine showed myelitis involving D2-D4 segments. Detailed etiologic evaluation was unyielding. With an initial diagnosis of seronegative NMOSD, she was treated with IV methylprednisolone and immunoglobulin. Other symptoms were limited to mild headaches.\u003c/p\u003e \u003cp\u003eDespite treatment, weakness progressed (grade II to 0), and the patient developed bilateral papilledema and lateral rectus palsy. CSF study showed lymphocytic pleocytosis (92 cells/cmm), with normal glucose and protein (58 mg/dl and 48 mg/dl respectively). Four sessions of plasma exchange were done. Following fetal bradycardia, emergency LSCS was done at 34 weeks of gestation.\u003c/p\u003e \u003cp\u003eIn view of clinical deterioration despite immunomodulation, mild hypoglycorrhachia (CSF:Serum ratio 0.55) and elevated opening pressure (56 cm H2O); workup for infectious etiologies was repeated. MRI study of the brain and MR venogram were normal, while the spinal cord showed diffuse enlargement (from cervicomedullary junction to conus) with patchy enhancement (Fig.\u0026nbsp;1). CSF wet mount showed motile trophozoites (Fig.\u0026nbsp;2a), and DNA PCR tested positive for \u003cem\u003eAcanthamoeba\u003c/em\u003e spp (Fig.\u0026nbsp;2b). Anti-amoebic therapy (amphotericin B, miltefosine, voriconazole, cotrimoxazole, and azithromycin) was initiated but later modified due to transaminitis.\u003c/p\u003e \u003cp\u003eSubsequently; CSF culture grew \u003cem\u003eAspergillus\u003c/em\u003e (culture positive, species unidentified) and \u003cem\u003eMycobacterium tuberculosis\u003c/em\u003e (Fig.\u0026nbsp;3a, b). Intraventricular CSF Gene Xpert (CBNAAT) was also positive. Persistent elevated intracranial pressure (\u0026gt;\u0026thinsp;55 cm of H2O) necessitated external ventricular drain placement. Despite maximal support, including modified ATT and intraventricular amphotericin B, she succumbed 9 weeks after symptom onset\u003c/p\u003e \u003cp\u003eShe belonged to a rural household with access to borewell and municipal water supplies. She had a habit of dipping feet into a fish tank at home (fish spa) Other than that exposure to stagnant water or soil was lacking. PCR of a water sample from her house tested positive for \u003cem\u003eBalamuthia\u003c/em\u003e and \u003cem\u003eParavahlkampfia\u003c/em\u003e spp.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis case represents a novel presentation of \u003cem\u003eAcanthamoeba\u003c/em\u003e infection as LETM in a pregnant woman, expanding the spectrum beyond GAE. The complex immune modulation in pregnancy, with controlled shift towards tolerance and TH2-like responses, increases susceptibility to opportunistic infections\u003csup\u003e3\u003c/sup\u003e. Although GAE has been reported in immunocompetent individuals also, disseminated disease and GAE is far more common in immunocompromised individuals, especially those with HIV, malnutrition, diabetes, kidney failure, cirrhosis, steroid use, chemotherapy, lymphoproliferative disorders, solid or bone marrow transplants, and agammaglobulinemia\u003csup\u003e1\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eThe diagnostic dilemma stemmed from the subacute onset and lymphocytic pleocytosis, with repeated CSF CBNAAT and autoimmune evaluations yielding negative results. The combination of fulminant intracranial pressure elevation, mild hypoglycorrhachia, and absence of an alternate etiology—features noted during the recent outbreak of \u003cem\u003eAcanthamoeba\u003c/em\u003e CNS infections in Kerala, India—ultimately guided the diagnosis in this patient.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eDiagnostic Challenges\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAmoebic trophozoites are best appreciated on fresh, unfixed samples at room temperature and may be mistaken for macrophages\u003csup\u003e4\u003c/sup\u003e.Standard light microscopy lacks the resolution to clearly distinguish the spiculated appearance\u003csup\u003e5.\u003c/sup\u003e.Amoebic load and trophozoite movements may also be variable, and repeated testing may be required\u003csup\u003e5\u003c/sup\u003e. Thus, microbiological identification of acanthamoeba is tedious in resource-limited settings.\u003c/p\u003e\n\u003cp\u003eFor our patient, the diagnosis was based on the species-specific 18S rRNA PCR method, developed by the molecular diagnostics division of The State Public Health Lab, Kerala, India. DNA extraction was performed using the Roche MagNA Pure automated nucleic acid extraction system and\u0026nbsp;the amoebae were detected by single plex real-time TaqMan PCR; using the previously published primers and probes targeting the 18S rRNA gene for\u0026nbsp;\u003c/p\u003e\n\u003col style=\"list-style-type: lower-alpha;\"\u003e\n \u003cli\u003e\u003cem\u003eAcanthamoeba\u003c/em\u003e spp\u003csup\u003e6\u003c/sup\u003e.\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eNaegleria fowleri\u003c/em\u003e\u003csup\u003e6\u003c/sup\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eBalamuthia mandrillaris\u003c/em\u003e\u003csup\u003e6\u003c/sup\u003e\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eParavahlkampfia francinae\u003csup\u003e7\u003c/sup\u003e\u003c/em\u003e; and\u0026nbsp;\u003c/li\u003e\n \u003cli\u003e\u003cem\u003eVermamoeba vermiformis\u003c/em\u003e\u003csup\u003e8\u003c/sup\u003e.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eAdditionally, a newly designed TaqMan probe was used for \u003cem\u003eVermamoeba vermiformis\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003eThe concentrations of primers and probes were maintained as previously published, and assays amplified using Quant Studio 5 real time PCR system (Applied Biosystems). The primer used for acanthamoeba spp. was 18S_F 5’-CCC AGA TCG TTT ACC GTG AA-3’, Aca 18S_R 5’-TAA ATA TTA ATG CCC CCA ACT ATC C-3’ and probe was 18S_P 5’-FAM-CTG CCA CCG AAT ACA TTA GCA TGG-BHQ1-3’. Positive and negative controls were included in each run. Using this method, the presence of \u003cem\u003eAcanthamoeba\u003c/em\u003e spp. was confirmed in our patient's CSF sample.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eTherapeutic Challenges\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe treatment of nervous system infections by \u003cem\u003eAcanthamoeba spp.\u003c/em\u003e is also challenging due to endosymbiosis\u003csup\u003e9\u003c/sup\u003e. The endosymbionts include bacteria like \u003cem\u003eCampylobacter jejuni, Escherichia coli, Legionella, Rickettsiales, Listeria\u003c/em\u003e, yeasts, giant viruses, algae, and protozoa \u003csup\u003e9\u003c/sup\u003e. There is evidence that \u003cem\u003eAcanthamoeba\u003c/em\u003e can harbor atypical mycobacteria and even \u003cem\u003eMycobacterium tuberculosis\u003c/em\u003e\u003csup\u003e10\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eAcanthamoeba can act as a “trojan horse” for microorganisms, which force their entry into amoebae, resist amoeba-mediated killing, and are hence protected by acanthamoeba’s ability to resist extreme temperatures, pH, and osmolarity\u003csup\u003e11,12\u003c/sup\u003e. Acanthamoeba is also used as a reservoir, and several organisms in environmental niches can multiply inside the trophozoites\u003csup\u003e12\u003c/sup\u003e. Failure to identify the \u003cem\u003eAspergillus\u0026nbsp;\u003c/em\u003especies in our patient may be because it is unrepresented in the MALDI-TOF database due to its environmental origin.\u003c/p\u003e\n\u003cp\u003eAcanthamoeba also exhibits a “genetic melting pot” phenomenon whereby exchange of genetic material between intracellular bacteria leads to the development of virulence traits\u003csup\u003e13\u003c/sup\u003e. The genome of intra-amoeba microorganisms is significantly larger than that of their relatives which also suggest this.\u003csup\u003e13\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003ePublic Health Challenges\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe patient's only documented water exposure was through fish-spa activities and household water use, without traditional high-risk behaviours such as swimming in warm freshwater bodies or exposure to contaminated soil. This profile indicates that epidemiologic links may be more diverse and ubiquitous than previously recognized. Early molecular testing for FLA should be integrated into diagnostic algorithms for atypical neurological presentations, especially in resource-limited settings where these amoebae may be more prevalent in water systems.\u003c/p\u003e\n\n"},{"header":"Key Learning Points","content":"\u003col\u003e\n \u003cli\u003eHaving pleocytosis in the CSF does not necessarily indicate an inflammatory demyelinating disorder of the nervous system.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eHypoglycorrhachia, refractory intracranial hypertension, and atypical natural history of the disease should prompt consideration of infectious etiologies.\u003c/li\u003e\n \u003cli\u003eClinicians should maintain high suspicion for free-living amoebae (FLA) in atypical neurological presentations, particularly in immunomodulated states.\u003c/li\u003e\n \u003cli\u003eMolecular diagnostics are essential due to the low sensitivity of wet-mount microscopy.\u003c/li\u003e\n \u003cli\u003eImportantly, exposure to stagnant water is not always necessary—household water sources may harbor FLA.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Declarations","content":"\u003ch4\u003eDISCLOSURES\u003c/h4\u003e\n\u003cp\u003eThe manuscript is original, and has been submitted to the Emerging Infectious Diseases; a publication of CDC (\u003cem\u003emanuscript number: EID-25-1853\u003c/em\u003e). We declare no conflicts of interest.\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from relative of the patient. Human Ethics Committee of Government Medical College Thiruvananthapuram, Kerala, India has approved the original study (HEC NO:27/16/2025/MCT) from which this data has been taken as specified in the protocol\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUse of AI tools\u003c/strong\u003e: used Grammarly to check the grammar and improve readability.\u003c/p\u003e\n\u003cp\u003eInformed consent for publication of this case report was obtained from the patient's husband following the patient's death. As the legal next of kin, the husband provided written consent for the use of clinical data and publication of this case. All efforts have been made to maintain patient confidentiality and anonymity.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eVisvesvara GS, Moura H, Schuster FL (2007) Pathogenic and opportunistic free-living amoebae: Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri, and Sappinia diploidea. FEMS Immunol Med Microbiol 50(1):1\u0026ndash;26. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/j.1574-695X.2007\u003c/span\u003e\u003cspan address=\"10.1111/j.1574-695X.2007\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e00232.x\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchumacher DJ, Tien RD, Lane K (2025) Neuroimaging findings in rare amebic infections of the central nervous system. Published online April 1, 1995. Accessed October 21. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ajnr.org/content/16/4/930.long\u003c/span\u003e\u003cspan address=\"https://www.ajnr.org/content/16/4/930.long\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNarayan B, Nelson-Piercy C (2020) Physiological Changes of the Immune System During Pregnancy. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/978-3-030-43477-9_15\u003c/span\u003e\u003cspan address=\"10.1007/978-3-030-43477-9_15\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eF MC GC (2025) Acanthamoeba spp. as agents of disease in humans. \u003cem\u003ePubMed\u003c/em\u003e. Accessed November 16. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/12692099/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/12692099/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaboratory Diagnosis of Primary Amoebic Meningoencephalitis | Laboratory Medicine | Oxford Academic. Accessed November 2 (2025) \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://academic.oup.com/labmed/article/54/5/e124/6987229\u003c/span\u003e\u003cspan address=\"https://academic.oup.com/labmed/article/54/5/e124/6987229\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGs YQ, Aj da VRS (2025) S. Multiplex real-time PCR assay for simultaneous detection of Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri. \u003cem\u003ePubMed\u003c/em\u003e. Accessed November 8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/17021087/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/17021087/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGs V et al (2025) R S, Y Q,. Paravahlkampfia francinae n. sp. masquerading as an agent of primary amoebic meningoencephalitis. \u003cem\u003ePubMed\u003c/em\u003e. Accessed November 8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/19602081/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/19602081/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMw K, Rm V, Ba W, van der HBHSD (2025) K. Quantitative detection of the free-living amoeba Hartmannella vermiformis in surface water by using real-time PCR. \u003cem\u003ePubMed\u003c/em\u003e. Accessed November 8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://pubmed.ncbi.nlm.nih.gov/16957190/\u003c/span\u003e\u003cspan address=\"https://pubmed.ncbi.nlm.nih.gov/16957190/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMungroo MR, Siddiqui R, Khan NA (2021) War of the microbial world: Acanthamoeba spp. interactions with microorganisms. Folia Microbiol (Praha) 66(5):689\u0026ndash;699. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s12223-021-00889-7\u003c/span\u003e\u003cspan address=\"10.1007/s12223-021-00889-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLooking in amoebae as a source of mycobacteria. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.micpath.2014.07.001\u003c/span\u003e\u003cspan address=\"10.1016/j.micpath.2014.07.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarker J, Brown MRW (1994) Trojan Horses of the microbial world: protozoa and the survival of bacterial pathogens in the environment. Microbiology 140(6):1253\u0026ndash;1259. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1099/00221287-140-6-1253\u003c/span\u003e\u003cspan address=\"10.1099/00221287-140-6-1253\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSiddiqui R, Khan NA (2012) Biology and pathogenesis of Acanthamoeba. Parasit Vectors 5(1):1\u0026ndash;13. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/1756-3305-5-6\u003c/span\u003e\u003cspan address=\"10.1186/1756-3305-5-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoliner C, Fournier PE, Raoult D (2010) Genome analysis of microorganisms living in amoebae reveals a melting pot of evolution. FEMS Microbiol Rev 34(3):281\u0026ndash;294. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/j.1574-6976.2009.00209.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1574-6976.2009.00209.x\" 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":true,"hideJournal":true,"highlight":"","institution":"Government Medical College,Thiruvananthapuram","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Acanthamoeba, longitudinally extensive transverse myelitis, hypoglycorrhachia, free-living amoebae, NMOSD, Aspergillus, Mycobacterium, FLA PCR, wet mount, trophozoite, Trojan horse, genetic melting pot","lastPublishedDoi":"10.21203/rs.3.rs-8385294/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8385294/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eWe report a unique case of \u003cem\u003eAcanthamoeba\u003c/em\u003e-induced longitudinally extensive transverse myelitis in a pregnant woman without classical epidemiologic risk factors. Cerebrospinal fluid (CSF) wet-mount microscopy and DNA PCR confirmed \u003cem\u003eAcanthamoeba\u003c/em\u003e spp. Coinfections with \u003cem\u003eAspergillus \u003c/em\u003espp. and tuberculous meningitis were also identified, highlighting the 'Trojan horse’ phenomenon.\u003c/p\u003e","manuscriptTitle":"Acanthamoeba-Induced LETM Mimicking NMOSD: A Rare Case Scenario","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-22 10:07:21","doi":"10.21203/rs.3.rs-8385294/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"8aa9c249-0dff-4583-87ff-5a92fcdf4c0f","owner":[],"postedDate":"December 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":59814441,"name":"Parasitology"},{"id":59814442,"name":"Neurology"},{"id":59814443,"name":"Infectious Diseases"}],"tags":[],"updatedAt":"2025-12-22T10:07:22+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-22 10:07:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8385294","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8385294","identity":"rs-8385294","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}