In vitro synergistic interaction of colistin and other antimicrobials against intrinsic colistin-resistant
Morganella morganii isolates.
3 Biotech 2023;
13:127. [PMID:
37064006 PMCID:
PMC10097849 DOI:
10.1007/s13205-023-03551-w]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 04/04/2023] [Indexed: 04/18/2023] Open
Abstract
Morganella morganii, a non-negligent opportunistic pathogen of the family Enterobacteriaceae, enlisted recently in the global priority pathogens by WHO for its swift propensity to acquire drug-resistant genes, engendering enhanced death rates. A combination of diverse antimicrobials could be recycled to overcome the ongoing acquisition of resistance mechanisms by M. morganii. Herein, we investigated the in vitro synergistic effect of colistin with meropenem, rifampicin, minocycline and linezolid against three intrinsic colistin-resistant M. morganii strains collected from critical departments of tertiary care hospitals. The strains were identified and tested for antimicrobial susceptibility by VITEK 2 automated system. The 16S rRNA sequencing was used to reconfirm the species identification. Minimum inhibitory concentrations (MICs) of colistin, meropenem, rifampicin, minocycline and linezolid were determined by the broth microdilution method. Synergistic interactions were studied by checkerboard and time-kill assay. The VITEK 2 identification and 16S rRNA sequencing confirmed that the strains were M. morganii. The automated antimicrobial susceptibility test revealed that all three isolates were multi-drug resistant. The checkerboard analysis demonstrated the synergy of all four combinations with FICI values ranging from 0.06 to 0.31 in all three isolates. These results suggest a potential role of meropenem as an adjuvant for treating M. morganii infections. The current work presented the first evidence of synergy between colistin and other antibiotics against M. morganii infection, which needs validation through in vitro and in vivo studies using a larger number of isolates.
Supplementary Information
The online version contains supplementary material available at 10.1007/s13205-023-03551-w.
Collapse