Investigation of the Presence of bla-AmpC (FOX) beta-lactamase in Klebsiella pneumonia isolates collected from different Clinical Specimens in Mazandran province, north Iran

Background: Klebsiella pneumoniae (Kp) is a major opportunistic pathogen responsible for diverse clinical infections. Research on AmpC genes is widespread; however, data on the prevalence of bla-AmpC (FOX) and its impact on pneumonia isolates from hospitalized patients are limited. The aim of this study was to evaluate the antimicrobial resistance profiles and presence of blaFOX in Kp strains recovered from hospitalized patients in Mazandaran province. Methods: ۱۰۰ Kp isolates were collected from clinical specimens, including urine (۴۹%), blood (۲۷%), sputum (۱۳%), wound (۵%), cerebrospinal fluid (۲%), and others (۴%). Antibiotic susceptibility testing was performed to assess resistance patterns. The combined disk test (CDT) was used to identify AmpC and β-lactamase producers. PCR analysis was conducted to detect AmpC production and the presence of the blaFOX gene among cefoxitin-resistant isolates. Resistance rates were compared with previous studies. Results: Resistance rates were highest for aztreonam (۷۷%), cefotaxime (۶۹%), and piperacillin (۶۸%). CDT confirmed AmpC and β-lactamase production in all isolates. Among ۶۱ cefoxitin-resistant isolates, PCR detected AmpC production in ۲۶ (۴۲.۶%), with ۱۴ (۲۲.۹۵%) harboring the blaFOX gene. Resistance rates to imipenem (۵۹%) and aztreonam (۷۷%) showed significant increases compared to earlier studies. Conclusion: The elevated antibiotic resistance in Kp strains underscores the need for effective antimicrobial stewardship and surveillance to manage and prevent the spread of resistant isolates.

کلیدواژه ها:

Klebsiella pneumonia ، ESBL ، Antimicrobial resistance ، CDT ، AmpC gene