ABSTRACT
@#Abstract: Objective To investigate the molecular characteristics and drug resistance of non-O1/non-O139 Vibrio cholerae in Zhongshan City, and to provide laboratory basis for cholera prevention and control. Methods The strains of non-O1/non-O139 Vibrio cholerae isolated from sporadic patients and aquatic products from 2015 to 2021 in Zhongshan city were collected. The identification and cluster analysis of the strains were analyzed by matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), the ctxA virulence gene of strains were detected by real-time fluorescence quantitative PCR, the cluster analysis of the strains was analyzed by pulsed-field gel electrophoresis (PFGE), and the drug resistance of the strains were analyzed by microbroth dilution method. Results From 2015 to 2021, 33 strains of non-O1/non-O139 Vibrio cholerae were isolated from Zhongshan City, including 28 strains from sporadic patients and 5 strains from aquatic products. Through MALDI-TOF-MS identification, 33 strains of non-O1/non-O139 Vibrio cholera can be identified to the level of species, and the identification results were all Vibrio cholerae. Among 33 non-O1/non-O139 Vibrio cholerae strains, 1 strain carried the ctxA virulence gene. The drug-resistant strains accounted for 69.7% (23/33), and the multidrug resistant strains accounted for 18.2% (6/33). A total of 7 kinds of drug resistance spectrum were produced, including 3 kinds of multidrug resistant spectrum, and showed drug resistance to 8 antibiotics, among which the resistance rates to streptomycin, cefazolin and compound sulfamethoxazole were above 30%. The 33 strains of non-O1/non-O139 Vibrio cholerae were divided into 32 PFGE fingerprints with a similarity ranging from 61.7% to 100%. MALDI-TOF-MS cluster analysis divided 33 non-O1/non-O139 Vibrio cholerae strains into two clusters. Conclusions The results of molecular typing of non-O1/non-O139 Vibrio cholerae in Zhongshan City presented diversity, and no significant correlation was found between PFGE and MALDI-TOF-MS cluster analysis. The strains demonstrated various degrees of resistance to certain antibiotics, and there were multidrug-resistant and toxigenic strains. Therefore, it is necessary to alert to the harmfulness of non-O1/non-O139 Vibrio cholerae and enhance monitoring.