Genomic insights of beta-lactamase producing Klebsiella quasipneumoniae subsp. similipneumoniae belonging to sequence type 1699 from retail market fish, India.

Klebsiella quasipneumoniae is a recently described species and often misidentified as Klebsiella pneumoniae. Here, we report the genomic characterization of Klebsiella quasipneumoniae subsp. similipneumoniae (India238 strain) isolated from fish. The annotated genome acknowledged the presence of blaCTX-M-15, blaOKP-B-1, fosA5, oqxAB and virulence genes. The strain with ST1699 and serotypes KL52 and OL103 also harboured insertion sequences (ISs): ISKpn26 and ISEc9. Three complete phage genomes were identified in contigs 1 and 6 of the bacterial genome, enhancing the prospects of genome manipulation. The study highlights the pitfall of conventional microbiological identification methods to distinguish K. pneumoniae and K. quasipneumoniae. This is the first Indian study documenting the incidence of extended-spectrum beta-lactamase (ESBL)-producing K. quasipneumoniae subsp. similipneumoniae from a non-clinical environment, equipped with virulomes and associated mobile genetic elements. Given that fish can act as a potential vector for transmission of antimicrobial resistance genes, our findings have paramount importance on human health.