Predominance of NDM and OXA‐48 Carbapenemase Coharboring Among Carbapenem Nonsusceptible Enterobacterales Isolates From Clinical Specimens at a Tertiary Hospital in Vietnam
Loan Hong Luong, Tuyen Thanh Ha, Quynh Nguyen, Phu Thien Truong, Duy Thanh Pham, Tuan Minh Huynh, My Dung JusselmeBackground
Antimicrobial resistance has emerged as a growing global public health threat. The increasing of carbapenem‐resistant Enterobacterales limits treatment options. A better understanding of the phenotype and genotype distribution of carbapenemase‐producing Enterobacterales is essential to prevent, reduce and control infection. This study is aimed at characterizing the phenotypic and genotypic carbapenemase profiles of carbapenem nonsusceptible Enterobacterales isolates collected from the diverse clinical specimens at a tertiary hospital in Ho Chi Minh City.
Methods
A total of 619 carbapenem nonsusceptible Enterobacterales strains were isolated from 548 clinical specimens. Species identification and antimicrobial susceptibility testing were performed using the BD Phoenix M50 system. Carbapenemase production was assessed using the modified Carbapenem Inactivation Method (mCIM). Carbapenemase‐encoding genes, including bla KPC , bla NDM , bla IMP , bla OXA-23 , and bla OXA-48 , in isolates with positive or inconclusive mCIM results (559 of 619) were detected by multiplex RT‐PCR.
Results
The results showed that median patient age was 71 years (IQR 60–81), with 55.7% of patient being male and 28.3% admitted to the intensive care unit. Klebsiella pneumoniae predominated (56.5%), followed by Klebsiella aerogenes (14.7%) and E. coli (14.4%). Resistance rates were 87.7% for ertapenem and 78.7% for meropenem. mCIM positivity was high in K. pneumoniae (92.9%), K. aerogenes (93.4%), and Serratia marcescens (92.7%), but lower in E. coli (59.6%) and E. cloacae (40.0%). All 9 carbapenemase‐gene‐positive isolates with inconclusive mCIM carried bla OXA-48 alone. In K. pneumoniae , bla NDM ‐ bla OXA-48 co‐carriage was most common (39.3%), followed by bla OXA-48 alone (26.2%), bla KPC alone (11.9%), and bla NDM alone (8.3%). E. coli and K. aerogenes predominantly harbored bla OXA-48 alone (66.7% and 58.1%).
Conclusion
The findings show a high burden of carbapenem nonsusceptible Enterobacterales in a Vietnamese tertiary hospital, largely driven by K. pneumoniae coharboring bla NDM and bla OXA-48 . Continuous molecular surveillance and strengthened antimicrobial stewardship are urgently needed to limit their dissemination in Vietnam.