blaNDM-5 is the predominant variant of blaNDM gene in Klebsiella species detected in Mississippi, USA
Year: 2025
Type: article
Abstract: • Monitoring emerging antibiotic resistance depends on real-time genomic surveillance • Dominance of bla NDM-5 in Klebsiella poses a public health threat in Mississippi • Genomic surveillance can contribute to understanding pathogenicity and virulence mechanisms • Role of plasmids in antimicrobial resistance and virulence dissemination implicated The Mississippi Public Health Laboratory conducts active surveillance of carbapenem-resistant Enterobacterales (CRE) infections as part of the Antimicrobial Resistance Laboratory Network (ARLN) program implemented by the United States Centers for Disease Control and Prevention (CDC). Here, we describe the prevalence of New Delhi Metallo-β-lactamase ( bla NDM ) genes in Klebsiella , a major pathogen of the Enterobacterales order linked to nosocomial infections, between January 2022 and June 2025. Carbapenemase activity was confirmed using the Modified Carbapenem Inactivation Method (mCIM). PCR was then performed on carbapenemase-positive isolates to detect bla NDM genes. Whole-genome sequencing (WGS) was performed on 35 bla NDM -positive isolates to identify bla NDM gene variants, other antimicrobial resistance (AMR) determinants, virulence factors, and plasmids. Antibiotic susceptibility testing (AST) was determined by the Kirby-Bauer disk diffusion assay. Among the 35 NDM-positive Klebsiella species, the bla NDM-5 variant was identified in 23 (65.7%) isolates, followed by bla NDM-1 and bla NDM-7 genes which were identified in 6/35 (17%) and 6/35 (17%) cases, respectively. A significant proportion of bla NDM-5 cases also harbored additional β-lactamase genes such as bla SHV family (18/23; 78%) and bla TEM-1 (9/23; 39%) indicating multi-drug resistance. All 23 bla NDM-5 -positive isolates were resistant to carbapenems and broad-spectrum cephalosporins, but 13/23 (56.5%) remained susceptible to aztreonam. PlasmidFinder analysis identified IncX3 (20/23) and IncFIB(K) (19/23) as the predominant plasmid replicons among these isolates. The emergence and spread of bacteria carrying bla NDM-5 gene poses a significant threat to public health in Mississippi. Our dataset warrants further study to investigate the potential role of plasmids in bla NDM-5 dissemination.
Authors: Srimadhav Nallani, Saihou Ceesay, Abiye Iyo, Lucersia Nichols, Daphne Ware, Beata Karolewicz
Institution: Mississippi State Department of Health
Language: English
Subfield: Molecular Medicine
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $1,890
OpenAlex ID: W4415426710