Whole-Genome Sequencing and Analysis of Chryseobacterium arthrosphaerae from Rana nigromaculata

Chryseobacterium arthrosphaerae strain FS91703 was isolated from Rana nigromaculata in our previous study. To investigate the genomic characteristics, pathogenicity-related genes, antimicrobial resistance, and genetic evolutionary relationships of this strain, PacBio RS II and Illumina HiSeq 2000 platforms were used for the whole genome sequencing. The genome size of strain FS91703 was 5,435,691 bp and GC content was 37.78%. A total of 4,951 coding genes were predicted; 52 virulence factors and 94 virulence genes were identified, with the most relevant genes involved in the virulence factor of immune regulation. Analysis of antibiotic resistance genes revealed that strain FS91703 harbored 10 antibiotic resistance genes in 6 categories and 2 multidrug-resistant efflux pump genes, including adeG and farA. Strain FS91703 was sensitive to β-lactam combination drugs, cephem, monobactam and carbapenems, intermediately resistant to phenicol, and resistant to penicillin, aminoglycosides, tetracycline, fluoroquinolones, and folate pathway inhibitors. Phylogenetic and ANI analyses suggested that strain FS91703 had the closest genetic relationship to the C. arthrosphaerae species; 16S rRNA sequencing revealed that both species were on the same branch of the evolutionary tree; FS91703 and FDAARGOS 519 ( C. arthrosphaerae ) or ED882-96 ( C. arthrosphaerae ) had ANI values of 96.69% or 96.13%, respectively. Thus, C. arthrosphaerae (FS91703) is a multidrug-resistant and highly virulent bacterium, providing theoretical support for the etiology and disease control due to C. arthrosphaerae in Rana nigromaculata . The results of this study are presented in the following pages.