Isolation of four carbapenem-resistant gram-negative species from a single fly

Abstract

Abstract The widespread occurrence of carbapenem-resistant organisms has garnered significant public attention. Arthropods, including flies, are important vectors of multidrug-resistant bacteria. In this study, we reported the simultaneous carriage of four carbapenem-resistant isolates from different species, namely, Escherichia coli (E. coli), Providencia manganoxydans (P. manganoxydan), Myroides odoratimimus (M. odoratimimus) and Proteus mirabilis (P. mirabilis), from a single fly in China. These isolates were characterized through antimicrobial susceptibility testing, conjugation assays, whole-genome sequencing, and bioinformatics analysis. M. odoratimimus showed intrinsic resistance to carbapenems. The mechanisms of carbapenem resistance in E. coli, P. manganoxydans, and P. mirabilis were due to the production of NDM-5, NDM-1 and NDM-1, respectively. Genetic context of the bla NDM genes in these three isolates varied. The bla NDM-5 gene in E. coli was located on an IncHI2/HI2A multidrug-resistant plasmid, which was conjugatively transferable. The bla NDM-1 gene in P. mirabilis resided on the pPM14-NDM_123k-like nonconjugative plasmid. The bla NDM-1 gene in P. manganoxydans was found in a nonconjugatively transferable, multidrug-resistant region. The results of this study enhance our understanding of the dissemination of carbapenem-resistant organisms and suggest the need for a more comprehensive approach to antibiotic resistance research encompassing humans, animals, and the environment.

Keywords

• Fly
• Carbapenem-resistant organism
• Whole-genome sequencing
• Phenotypic characterization
• bla NDM