Cellular Fatty Acid Analysis of Vibrio vulnificus Strains Isolated from Korea

ABSTRACT

Vibrio vulnificus infection is one of the most fatal diseases in Korea. This study was undertaken to determine the cellular fatty acid (CFA) compositions of ninety-five clinical strains of V. vulnificus isolated from Korea during 1985-1995. We compared these results with the CFA profile of V. vulnificus in the Microbial Identification System (MIS) (CLIN library version 3.9; Microbial ID Inc., Newark, Del.), and also evaluated the MIS ability to identify V. vulnificus. Subgrouping of V. vulnificus by CFA analysis was performed and its results were compared with those of serotyping. Most of the CFAs in V. vulnificus strains were similar to the CFA profile of V. vulnificus in the MIS, but some distinctive differences were observed. First, means of two major CFAs, 16:0 and 16:1w7c, were 22.16% and 18.26% in this study, but 23.52% and 25.44% in the MIS respectively. Second, all isolates had 11:Oiso3OH, which was not present in the MIS. Eighty-five strains (89.5%) disclosed the first choice identification of V. vulnificus by the MIS, but only two strains (2.1%) were identified with SI values of 0.6. Remaining ten strains (10.5%) showed 'NO MATCH' results. Cluster analysis of CFA could separate V. vulnificus into nine subgroups, and predominant subgroups were subgroup VII (45 strains) and V (36 strains). There was heterogeny between subgroups by CFA and serotypes of V. vulnificus. The strains of 04 serotype which accounted for 80% (76/95) of the isolates were distributed into six different subgroups such as VII (40 strains), V (27 strains), III (4 strains), I (2 strains) and VI (1 strain). These showed that V. vulnificus strains isolated from Korea had different characteristics in the CFA composition in comparison with the MIS V. vulnificus library. Subgrouping by the CFA analysis might be a useful tool for the epidemiological study of V. vulnificus infection in Korea.