High prevalence of carbapenem resistance and clonal expansion of blaNDM gene in Klebsiella pneumoniae isolates in an Iranian referral pediatric hospital

Abstract

BackgroundThe increasing global concern regarding antibiotic resistance necessitates in-depth studies to comprehend the phenotypic and genotypic characteristics of resistant bacterial strains. This study aimed to investigate the prevalence, antibiotic resistance profiles, and molecular characteristics of carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates in an Iranian referral pediatrics hospital. Methods: In this study, we examined CRKP isolates collected from hospitalized pediatric patients across various wards. The isolates underwent antimicrobial susceptibility testing, the polymerase chain reaction (PCR) analysis for carbapenemase genes (blaNDM, blaVIM and blaIMP), and genetic relatedness assessment using pulsed-field gel electrophoresis (PFGE).ResultsAmong 166 K. pneumoniae isolates, 54 (32.5%) exhibited resistance to carbapenems. Notably, all these resistant isolates were resistant to imipenem, with 35 (65%) displaying resistance to both imipenem and meropenem. Of the 54 CRKP isolates, 24 (44%) were metallo-β-lactamases (MBL)-producing. The prevalence of the blaNDM gene among CKCP and MBL-producing isolates was 20% (n = 11) and 44% (n = 24), respectively. The blaVIM and blaIMP genes were not detected in any of the isolates. Twenty-six CRKP isolates (48%) were recovered from ICUs. PFGE analysis of CRKP isolates revealed 20 clusters, with cluster S being the most prevalent, comprising 24% of the total (n = 13).ConclusionOur study reveals a concerning prevalence of carbapenem resistance in K. pneumoniae isolates. Specifically, the detection of the blaNDM gene in 20% of CRKP isolates, with a significant proportion (82%) observed in isolated CRKP from the ICUs and emergency departments, underscores the potential clonal expansion of these resistant strains within these critical hospital wards.