Abstract:

Objective   To identify strains isolated from one cholera case in Jining of Shandong Province, China in 2013 and to study their drug resistance and etiological characteristics. Methods  Samples from watery diarrhea and cooking utensils were cultured and isolated to get individual bacterial colonies. Gram′s staining, O1/O139 group serum agglutination and biochemical reaction were performed and virulence genes, antibiotic resistance profiles and related resistance genes were determined. Molecular subtyping was carried out by pulsed-field gel electrophoresis (PFGE). Results  All the 3 strains isolated from watery diarrhea and cooking utensils were identified as V. cholerae O139 strains and their PFGE patterns were exactly identical. Cluster analysis also showed that the PFGE pattern of the 3 strains was similar to that of one V. cholerae O139 strain separated from Jining in 2005 with a homology of 93.3%. The 3 strains harbored virulence genes， hlyA， ctxAB， toxR， tcpI， rtxA and tcpA， and antibiotic-resistance genes, intI1, intI4 and sxt. Besides, they were all resistant to trimethoprim-sulfamethoxazole, kanamycin and doxycycline, and sensitive to other 8 kinds of antibiotics. Conclusion  This cholera was caused by infection of V. cholerae O139 strain with a strong virulence and multi-drug resistance from cooking utensils. Strains of V. cholerae exist in environment all the time, so prevention and control of cholera still need consistent efforts.

Key words: Cholera, Antibiotic resistance, Pulsed-field gel electrophoresis, Virulence