Genetic features of blaNDM-1 harboring Klebsiella pneumoniae isolates from Kerman, Iran.

BACKGROUND

The genetic features of harboring Klebsiella pneumoniae isolates from Kerman, Iran, are important to investigate, as they can reveal the genetic diversity, resistance mechanisms, and potential virulence of these clinically significant strains, contributing to better understanding and control of their spread in both local and global contexts.

METHODS

In this study, we report the genetic features of 37 NDM-1-harboring K. pneumoniae, including the ability to biofilm formation, resistance genes, virulence factors, toxin-antitoxin systems (TAs), class of integrons, gene mapping of the blaNDM-1, and genetic relationships using polymerase chain reaction (PCR) and sequencing.

RESULTS

All isolates were biofilm producers, and serotype K20 was the most common capsular type. Various virulence factors were detected among the NDM-1-harboring K. pneumoniae, but they were not hypervirulent K. pneumoniae (hv-KP). Class I integrons were identified in all isolates, and 62% (23/37) of the isolates carried at least one gene in the variable region of the class 1 integron. The pemI/pemK, ccdA/ccdB, and hok/sok TAs were found in 100% (37/37) of the isolates. The downstream region sequences of the blaNDM-1 were the same in the isolates, while a high diversity was observed in the upstream region sequences of blaNDM-1. Based on ERIC-PCR, 23 isolates were divided into 7 clusters, and 14 isolates were identified as a single genotype.

CONCLUSION

Our study revealed genetic diversity, high pathogenicity, and resistance to various antibiotic agents in NDM-1-harboring K. pneumoniae, which can cause significant concern in hospital settings.