An insight into the genome of extensively drug-resistant and uropathogenic Citrobacter werkmanii.J Glob Antimicrob Resist. 2020 Jun 30 [Online ahead of print]JG
Carbapenemase producing bacteria poses serious threat to public. This study was performed to understand the emergence and genetic features of NDM-producers in hospital setting.
MATERIALS AND METHODS
Samples were collected from tertiary care hospital. Isolate identification was carried out by 16S rRNA sequencing. The genome of Citrobacter werkmanii (AK-8) was sequenced on Illumina-NextSeq-500 platform. Resistant determinants and pathogenicity islands were determined by ResFinder and PathogenFinder, respectively. MLST, two-component system and transcription factors were identified by P2RP server, while, variant calling and insertion sequences were determined by Galaxy and ISfinder, respectively. AK-8 genome was compared with Escherichia coli (536-UPEC).
It is the first report on whole genome analysis of extensively drug-resistant NDM-6 producing uropathogenic Citrobacter werkmanii, ST-104. Resistance genes for all antibiotics except colistin, fosfomycin, fusidic-acid, nitroimidazole, oxazolidinones, tetracycline and glycopeptides were detected in the isolated strain. The genome analysis of AK-8 led us to identify BaeSR two-component system, regulating the production of multidrug efflux proteins. The virulence was found to be regulated by CpxRA, ZraRS, RstAB, UhpAB, AcrAB, RcsBc, and UvrY whereas, Bar-UvrY was found to control carbon metabolism, flagellum biosynthesis and biofilm formation. AK-8 genome encodes 21 chemoreceptors, helping in colonization and pathogenesis. Fur family transcriptional regulator, cAMP receptor protein and RpoS were found to increase virulence of AK-8. ntBLAST analysis showed 69.60% genetic identity with E. coli 536 as an adaptive feature acquired for survival.
The emergence of extensively drug-resistant and pathogenic Citrobacter werkmanii is alarming and it should not be ignored as commensal.