Comparison of Biological and Genetic Characteristics Between Sucrose-Fermenting and Sucrose-Nonfermenting Vibrio vulnificus Isolates

ABSTRACT

Twelve strains of V. vulnificus isolated from clinical specimens in 2002~2004 in Jeollado province were determined for their biologic groups, serotypes, presence of vvhA (hemolysin/cytolysin) gene, DNA sequence, and PFGE patterns of NotI-restricted genomic DNA. The following results were obtained. All 12 isolates were biogroup 1, and API 20E profiles were 5146105 for 5 (41.7%) isolates, and 5148125 for 2 isolates with sucrose fermentation. Ten (83.3%) of the 12 isolates was V. vulnificus serotype O4A, and two sucrose-fermenting isolates belonged to serotype O2. Alleles of cytolysin-hemolysin gene were detected in all 12 isolates. The nucleotide sequences of vvhA genes from strains WKHC 212 and WKHC 221 showed 94~97% similarity compared with those from previously reported 7 strains, YJ016, CMCP6, L-180, CDC B3547, IF Vv10, CIP 75.4T and CNRVC 970121. PFGE of NotI-restricted genomic DNA from the 12 isolates showed approximately 48.5 to 873-kb fragments and they were clustered to five (A to E) patterns. Two sucrose-fermenting isolates belonged to pattern D with 95% similarity with each other. Two strains isolated from two different patients had two identical patterns C and D. It is concluded that sucrose-fermenting strains also exist among clinical isolates of V. vulnificus in Korea, and they can be identified by using API 20E system, and by detecting vvhA gene. DNA sequences and PFGE pattern of NotI-restricted genomic DNA suggested that the two sucrose-fermenting isolates belonged to an identical clone, and two strains each isolated from two different patients belonged to two identical clones.