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Background: Carbapenemase-producing Enterobacterales (CPE) are spreading in hospitals, environment and retail foods in Yangon, Myanmar., Objectives: To investigate whether CPE colonize healthy individuals living in Yangon and whether clinical-related strains are spreading in the community., Methods: CPE was isolated from faecal samples obtained from healthy Japanese residents of Yangon with no history of hospitalization. Isolates were subjected to WGS using short- and long-read sequencers and compared with those previously isolated in Yangon., Results: Six Escherichia coli strains harbouring blaNDM-1 or blaNDM-5 belonging to five different STs-ST10, ST38, ST48, ST410 and ST8453-were isolated from 69 volunteers. The ST38 isolates were related to those previously isolated from retail food in Yangon. The ST410 and ST8453 isolates were highly related to previous Yangon isolates including those of clinical and food origins., Conclusions: The analysis suggested the acquisition of blaNDM-positive E. coli, which are disseminating in a clinical setting and through retail foods, by healthy residents in Yangon., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Shewanella sp., the progenitors of bla OXA-48 -like genes are increasingly reported with the possession of different bla OXA-48 -like variants. This study aims to characterize bla OXA-731 , a new variant of a bla OXA-48 -like gene identified in Shewanella sp. isolated from the aquatic environment in Myanmar. Phylogenetic analysis of the bla OXA-731 sequence with other bla OXA-48 -like variants showed that it has the highest nucleotide identity of 86.09% with bla OXA-48 . However, the active site motifs in OXA-731 were 100% identical to that in OXA-48. Whole-genome sequencing analysis showed that bla OXA-731 is not surrounded by any mobile genetic elements. The genetic context of bla OXA-731 was found as similar to other bla OXA-48 -like genes previously identified in Shewanella sp. S1 nuclease pulsed-field gel electrophoresis followed by Southern blotting confirmed the location of bla OXA-731 in the chromosome of the Shewanella genome. Cloning and expression studies showed that OXA-731 has β-lactamase activity similar to OXA-48 and OXA-181, but it has no significant carbapenemase activity. Our results showed the significance of bla OXA-48 -like-carrying Shewanella sp. in the spreading of bla OXA-48 -like genes in the community., (© 2020 Society for Applied Microbiology and John Wiley & Sons Ltd.)

The spread of carbapenemase-producing Enterobacteriaceae (CPE) poses a serious threat to clinical practice and public health. These bacteria are present both in clinical settings and non-clinical environments. The presence of CPE in food stuffs has been reported, but sporadically so. Here, we screened for CPE in meat, seafood, and vegetable samples from local markets of Yangon, Myanmar. We obtained 27 CPE isolates from 93 food samples and identified 13 as Escherichia coli, six as Klebsiella pneumoniae, seven as Enterobacter cloacae complex, and one as Serratia marcescens. All except the E. cloacae complex harboured the carbapenemase genes bla NDM-1 or bla NDM-5 , while all Enterobacter isolates carried the carbapenemase gene bla IMI-1 . The bla IMI-1 gene was located in putative mobile elements EcloIMEX-2, -3, or -8. Using multi-locus sequence typing, E. coli, K. pneumoniae, and E. cloacae complex isolates were classified into 10, six, and five different sequence types, respectively. Our results demonstrate that diverse organisms with various carbapenemase genes are widespread in the market foods in Yangon, highlighting the need for promoting proper food hygiene and effective measures to prevent further dissemination.

The spread of carbapenemase-producing Enterobacteriaceae (CPE), contributing to widespread carbapenem resistance, has become a global concern. However, the specific dissemination patterns of carbapenemase genes have not been intensively investigated in developing countries, including Myanmar, where NDM-type carbapenemases are spreading in clinical settings. In the present study, we phenotypically and genetically characterized 91 CPE isolates obtained from clinical ( n = 77) and environmental ( n = 14) samples in Yangon, Myanmar. We determined the dissemination of plasmids harboring genes encoding NDM-1 and its variants using whole-genome sequencing and plasmid analysis. IncFII plasmids harboring bla NDM-5 and IncX3 plasmids harboring bla NDM-4 or bla NDM-7 were the most prevalent plasmid types identified among the isolates. The IncFII plasmids were predominantly carried by clinical isolates of Escherichia coli , and their clonal expansion was observed within the same ward of a hospital. In contrast, the IncX3 plasmids were found in phylogenetically divergent isolates from clinical and environmental samples classified into nine species, suggesting widespread dissemination of plasmids via horizontal transfer. Half of the environmental isolates were found to possess IncX3 plasmids, and this type of plasmid was confirmed to transfer more effectively to recipient organisms at a relatively low temperature (25°C) compared to the IncFII plasmid. Moreover, various other plasmid types were identified harboring bla NDM-1 -harboring plasmids among CPE isolates in Myanmar, contributing to a better understanding of their molecular epidemiology and dissemination in a setting of endemicity.2 , among clinical isolates of Klebsiella pneumoniae or Enterobacter cloacae complex. Overall, our results highlight three distinct patterns of the dissemination of bla NDM -harboring plasmids among CPE isolates in Myanmar, contributing to a better understanding of their molecular epidemiology and dissemination in a setting of endemicity., (Copyright © 2019 American Society for Microbiology.)

The bacterial enzyme New Delhi metallo-β-lactamase hydrolyzes almost all β-lactam antibiotics, including carbapenems, which are drugs of last resort for severe bacterial infections. The spread of carbapenem-resistant Enterobacteriaceae that carry the New Delhi metallo-β-lactamase gene, blaNDM, poses a serious threat to public health. In this study, we genetically characterized eight carbapenem-resistant Escherichia coli isolates from a tertiary care hospital in Yangon, Myanmar. The eight isolates belonged to five multilocus-sequence types and harbored multiple antimicrobial-resistance genes, resulting in resistance against nearly all of the antimicrobial agents tested, except colistin and fosfomycin. Nine plasmids harboring blaNDM genes were identified from these isolates. Multiple blaNDM genes were found in the distinct Inc-replicon types of the following plasmids: an IncA/C2 plasmid harboring blaNDM-1 (n = 1), IncX3 plasmids harboring blaNDM-4 (n = 2) or blaNDM-7 (n = 1), IncFII plasmids harboring blaNDM-4 (n = 1) or blaNDM-5 (n = 3), and a multireplicon F plasmid harboring blaNDM-5 (n = 1). Comparative analysis highlighted the diversity of the blaNDM-harboring plasmids and their distinct characteristics, which depended on plasmid replicon types. The results indicate circulation of phylogenetically distinct strains of carbapenem-resistant E. coli with various plasmids harboring blaNDM genes in the hospital.