Unraveling Genetic Diversity and Antibiotic Resistance Mechanisms in Citrobacter freundii Isolates From Meat Products: Implications for Food Safety and Public Health.

Abstract

Citrobacter freundii is a zoonotic bacterium with special public health importance as a carrier and source of multidrug resistance (MDR) genes. Here, the prevalence, genetic heterogeneity, and antimicrobial resistance pattern of C. freundii from chicken and red meat in Shahrekord, Iran, were examined. Cross-sectional design and a combination of molecular methods with random amplified polymorphic DNA (RAPD-PCR), enterobacterial repetitive intergenic consensus (ERIC-PCR), and repetitive extragenic palindromic PCR (REP-PCR) and phenotypic methods were used for identifying genotypic patterns and resistance markers such as blaCTX-M, qnr (within PMQR plasmids), and sul1 genes. RAPD-PCR was the most discriminative and identified significant genetic diversity in the poultry isolates. The findings describe an alarming prevalence of MDR with resistance patterns correlated with farming practice and antibiotic exposure. Seasonal patterns in the degree of contamination were also described, highlighting focused intervention and judicious antimicrobial stewardship. The research emphasises the utilisation of integrated surveillance systems and molecular diagnostic approaches to mitigate the public health issues resulting from C. freundii throughout the food chain.