Ecological and laboratory assessment of the resistance spectrum and antibacterial susceptibility of Vibrio cholerae strains isolated in the Caspian region of Kazakhstan

Given Kazakhstan’s geographical proximity to the Caspian Sea and the detection of V. cholerae in river systems connected to the Caspian basin, this study also contributes to a broader understanding of cholera ecology and antimicrobial resistance within the region. For the first time, this study identified and thoroughly examined the role of genetic and biochemical factors contributing to the development of resistance in Vibrio cholerae strains under the conditions of the Republic of Kazakhstan. A comprehensive analysis was conducted on the antibiotic resistance of V. cholerae strains isolated in Kazakhstan from ۱۹۹۷ to ۲۰۲۳, with a focus on their potential for persistence, adaptation, and spread within the broader Caspian ecological network. Molecular and biochemical mechanisms underlying the development of resistance were investigated, and their potential impact on the epidemiological situation and biological safety was assessed.  Phenotypic susceptibility testing of V. cholerae (n = ۱۳) conducted in vitro demonstrated high sensitivity to cefotaxime, tetracycline, doxycycline, ciprofloxacin, and kanamycin. A similarly high level of susceptibility was observed for gentamicin, chloramphenicol, ampicillin, and rifampicin (۹۶.۲% of isolates). Real-time PCR results revealed no presence of resistance genes to glycopeptide or beta-lactam antibiotics in the tested V. cholerae strains. However, vanA/B genes (Ct = ۹.۱۶۶, FAM channel) and the tem gene (Ct = ۳۴.۶۰, CY۵ channel) were detected in the control strains Escherichia coli ATCC ۲۵۹۲۲ and Pseudomonas aeruginosa ATCC ۹۰۲۷ (Ct = ۸.۹۵۴ and ۲۴.۸۵, respectively). In conclusion, the absence of resistance to major classes of antimicrobial agents among all ۱۳ V. cholerae isolates indicates the continued high clinical efficacy of these antibiotics in the treatment of cholera. These findings are of critical importance in the context of potential epidemic outbreaks and environmental persistence of V. cholerae in Caspian-associated aquatic systems, as they provide clinicians and public health officials with a reliable basis for empirical therapy selection and regional preparedness planning.

کلیدواژه ها:

Cholera strains ، Antibiotics ، Resistance ، Sensitivity ، Statistics