A Molecular Epidemiologic Study by Plasmid DNA and Random Amplified Polymorphic DNA Analyses of Salmonella enterica serotype Enteritidis Isolated in Food Borne Outbreaks in Gwangju, 1997 / 감염과화학요법

ABSTRACT

BACKGROUND: During the past 10 years, there has been an increased incidence of gastrointestinal infections caused by salmonellae in Korea. In 1999, there were several outbreaks and sporadic occurrences of food borne infections due to Salmonella enterica serotype Enteritidis in Gwangju. Thus, there is a need for careful monitoring of its occurrence. METHODS: Salmonella Enteritidis were isolated from feces samples of patients with foodborne diarrhea in Gwangju, 1999. We performed antigen typing, examination of biochemical properties, anibiotic susceptibility test, plasmid typing and RAPD analysis to characterize of S. Enteritidis isolates. RESULTS: There were three Salmonella outbreaks (April, July, October), and 203 isolates of S. Enteritidis were isolated from the 286 patients. Eighteen isolates were obtained from the patients of sporadic occurrences. Antigenic types of the isolates were O antigen; D1 (1, 9, 12), H antigen phase 1; (g, m), serotype; Enteritidis. The isolates were susceptible to most of the antibiotics. We performed plasmid DNA analysis of the isolates, and the results showed 3 plasmids (8, 6, 3.8 kb) in 14 of 14 strains from outbreaks; 3 plasmids (8, 6, 3.8 kb) in 2 isolates from sporadic cases; 4 plasmids (8, 6, 3.8, 2 kb) in 10 isolates from sporadic occurrences, and 2 isolates from food specimens. However, 1 isolate from patients and 2 isolates from Ham-Yang, Kyung Nam, did not contain plasmids. RAPD analysis showed that all isolates from Gwangju in 1999 showed relatively uniform characteristics which were different from those derived from Ham-Yang, Kyung-Nam. CONCLUSION: The present data demonstrated that most food poisoning cases by S. Enteritidis in Gwangju, 1999, were originated from the same Salmonella Enteritidis strains.