Chitinophaga vietnamensis sp. nov., a multi-drug resistant bacterium infecting humans.

We describe a new multidrug resistant Chitinophaga species that was isolated from patients with type 2 diabetes in Vietnam. Strain BD 01T was cultivated in 2017 from a blood sample of a patient suffering from bacteremia. Strain VP 7442 was isolated in 2018 from a pleural fluid sample of a patient who had presented with lung abscess and pleural effusion. Both strains are aerobic, Gram-negative, non-motile and non-spore-forming. The 16S rRNA gene sequences of both strains are 100 % similar and share a highest 16S sequence identity with Chitinophaga polysaccharea MRP-15T of 97.42 %. Their predominant fatty acid is iso-C15 : 0 (73.8 % for strain BD 01T and 79.8 % for strain VP 7442). The draft genome sizes of strains BD 01T and VP 7442 are 6 308 408 and 6 308 579 bp, respectively. They are resistant to beta-lactams, aminoglycosides, fluoroquinolones, metronidazole, fosfomycin, vancomycin and macrolides, and exhibit 20 and 18 antimicrobial resistance-related genes, respectively. Using the multiphasic taxonogenomic approach, we propose that strains BD 01T (=CSUR P9622=VTCC 70981) and VP 7442 (=CSUR P9623=VTCC 70982) represent a new species, for which we propose the name Chitinophaga vietnamensis sp. nov. Strain BD 01T was chosen as type strain of C. vietnamensis sp. nov.