Prevalence of Metallo-β-Lactamase Genes in Clinical Isolates of Klebsiella pneumoniae in Health Care Centers in Mazandaran Province

Background: Klebsiella pneumoniae is one of the most important causes of opportunistic infections, includinglobar pneumonia, urinary tract infection (UTIs), and wound infection. Treatment of disease caused by thisbacterium has also become a challenge, as many strains are resistant to all β-lactam antibiotics. Metallo-β-lactamases hydrolyze most β-lactam antibiotics, especially carbapenems, but cannot inactivate monobactams.This study aimed to determine the prevalence of Metallo-β-lactamase genes (blaIMP, blaVIM, and blaNDM) in K.pneumoniae isolated from clinical specimens.Methods: Clinical samples were collected from hospitals of Mazandaran province. Among ۵۰۰ clinical samplescollected, only ۴۰ Klebsiella pneumoniae isolates were detected by culture and biochemical tests. Antimicrobialsusceptibility testing was performed on all isolates by the Kirby-Bauer method. The polymerase chain reaction(PCR) technique was used for the identification of blaIMP, blaVIM, and blaNDM genes.Results: Antibiogram by disk diffusion method showed that ۲۱ (۵۲%) and ۱۹ (۴۸%) isolates were classified asimipenem resistant and sensitive, respectively. Of all the samples, ۳۰ (۷۵%), ۷ (۱۷.۵%), and ۳۶ (۹۰%) containedblaVIM, blaIMP, and blaNDM genes, respectively. The co-existence of the blaVIM and blaNDM genes was observed in۲۲ (۵۵%) isolates. The presence of both blaIMP and blaNDM genes was confirmed in ۲ (۵%) of the isolates. Fourisolates (۱۰%) had blaNDM, blaIMP, and blaVIM genes simultaneously, but none of these genes were present in oneisolate (۲.۵%).Conclusions: This study showed that the prevalence of metallo-β-lactamase genes in K. pneumoniae isolatedfrom clinical specimens is very high, so it is recommended that physicians treat patients based on phenotypicand genotypic characteristics.

Keywords:

Metallo-β-lactamase , Resistance gene , Klebsiella pneumoniae , Clinical samples