Background: Shewanella genus, as an important carrier of resistance genes, has the potential to transmit resistance to many antimicrobials in many circumstances, especially in aquatic environment. The aim of the study was to describe the risk of Shewanella xiamenensis in hospital environment through analysis of genomic comparison and resistance status.
Methods: Seven S. xiamenensis strains were isolated from hospital wastewater. PCR and Sanger sequencing were carried out for detection of common carbapenemase genes. Antimicrobial susceptibility testing was performed to determine the antimicrobial profile. Whole genome sequencing was applied, and sequences were further used for genomic analysis.
Results: Seven Shewanella xiamenensis were all positive for bla _NDM and bla _OXA-48. Antimicrobial susceptibility testing showed all Shewanella xiamenensis were resistant to cefotaxime, ceftazidime, imipenem, meropenem, gentamycin and trimethoprim-sulfamethoxazole. Whole genome sequencing and phylogenetic analysis demonstrated the diversity of Shewanella xiamenensis despite isolating from one wastewater pool.
Conclusion: To the best of our knowledge, this is the first report of detection of three types bla _OXA-48-like genes in one hospital in China. And we have detected multi-drug resistant S. xiamenensis from hospital wastewater. This emphasizes that the presence of naturally existing carbapenemases in the environment may be significantly overlooked and that the bla _OXA-48-like genes in China may originate through the horizontal gene transfer from S. xiamenensis to Enterobacterales rather than import from other countries.
Keywords: OXA-48, NDM, Shewanella xiamenensis , hospital wastewater, reservoir, horizontal transmission, surveillance, New Delhi metallo-β-Lactamase