Antibiotic Resistance of Surface Water Vibrio Cholerae non-O1/non-O139 Isolates

Abstract

Introduction: V. cholerae non-O1/non-O139 strains are etiological agents of acute intestinal infections of various severity. Monitoring of antibacterial drug resistance of their environmental isolates circulating in specific areas is of great importance for local disease prediction and prevention as well as for an effective choice of drugs for etiotropic therapy. Objective: To study antibacterial drug resistance of V. cholerae non-O1/non-O139 strains isolated from surface water sam­ ples within the annual monitoring of cholera at the Reference Center of the Rostov-on-Don Anti-Plague Research Institute in 2019–2020. Materials and methods: We tested 263 and 87 V. cholerae non-O1/non-O139 strains isolated from surface water samples in the years 2019 and 2020, respectively, for susceptibility and/or resistance to antibacterial drugs recommended for emergency cholera prevention and treatment using the method of serial dilutions in Mueller–Hinton agar. Results and discussion: All the isolates were typical non-toxigenic V. cholerae strains containing hlyA genes and lacking wbe-, wbf-, ctxA, tcpA- ones. When comparing the annual proportions of Vibrio cholerae species resistant to different antibiotics, we observed statistically significant changes in the share of those resistant to ampicillin (from 39.2 % to 98.8 %), cefotaxime (from 1.5 % to 5.7 %), and rifampicin (from 31.2 % to 8.0 %). All the studied vibrios remained susceptible to gentamicin and doxycy­ cline. The data for 2019–2020 indicate a statistical increase in the proportion of multidrug-resistant strains. Conclusion: Our findings substantiate the necessity of further monitoring studies to understand the spread of antibacterial drug resistance among V. cholerae non-O1/nonO-139 strains.