Frequency of Beta-lactamase Genes (blaSHV, blaTEM, blaCTX-M-15, blaKPC, blaOXA-48) in Multidrug-resistant Klebsiella pneumoniae

Document Type : Research Article

Authors

• Masoumeh Lak Hondori
• maryam Mohammadi-Sichani
• Mozhgan Ghiasian

Department of Microbiology, Fal. C., Islamic Azad University, Isfahan, Iran

10.22034/ijmcm.2025.710258

Abstract

The global spread of multidrug-resistant (MDR) strains of Klebsiella pneumoniae is a significant public health concern. This study aims to investigate the prevalence of beta-lactamase genes blaSHV, blaTEM, blaCTX-M-15, blaKPC, and blaOXA-48 in MDR K. pneumoniae isolates obtained from nosocomial infections in Isfahan, Iran. Ninety-six K. pneumoniae isolates were collected from clinical infections. After confirming the identity of the isolates through biochemical tests, their antibiotic sensitivity was assessed using the disk diffusion method. Extended-spectrum beta-lactamase production was evaluated with the combination disk method, utilizing cefotaxime and cefotaxime/clavulanic acid. The presence of beta-lactamase genes was detected using specific primers and PCR. All isolates were resistant to amoxicillin. Additionally, resistance was observed in 56.25% of isolates to imipenem, 57.29% to cephalothin, 52.08% to ciprofloxacin, and 52.08% to cefotaxime. Conversely, the highest sensitivity was recorded for tetracycline (64.58%), followed by chloramphenicol (61.45%), gentamicin (56.25%), and nitrofurantoin (54.16%). Phenotypic testing revealed that all 96 isolates were positive for broad-spectrum beta-lactamases. Moreover, 44 isolates were classified as MDR, exhibiting resistance to at least three different antibiotic classes. The frequencies of the blaKPC, blaOXA-48, blaCTX-M-15, blaTEM, and blaSHV genes among MDR strains were 45.45%, 50%, 72.72%, 84.09%, and 86.36%, respectively. The presence of MDR isolates and broad-spectrum beta-lactamase genes, particularly in K. pneumoniae, highlights the need for cautious management of these infections.

Keywords

• Klebsiella
• Multidrug resistant
• antibiotic resistance
• beta lactamase
• Polymerase chain reaction

Main Subjects

• Clinical Microbiology

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