Detection of Campylobacter jejuni by Multiplex PCR and Patterns of Pulsed-Field Gel Electrophoresis

Lee, Jae Kyoo; Kim, Kwang Yup; Koo, Myoung Sook; Yong, Dong Eun; Kim, Eui Chong

Abstract

BACKGROUND: Campylobacter is the most common bacterial cause of food-borne infection in developed countries, and handling or eating of contaminated poultry products was reported as the major cause of human campylobacteriosis in sporadic cases. This study was performed to investigate the prevalence of Campylobacter in patients with diarrhea and raw chickens of grocery, and identify the species by multiplex PCR and determine the genotypes of isolates by SmaI pulsedfield gel electrophoresis(PFGE) profiles.
METHODS
Eight hundred and fifty six stool specimens obtained from 773 hospitalized patients with diarrhea and 16 raw chickens purchased from grocery were tested. Karmali's charcoal based selective medium and Campylobacter enrichment broth were used for isolation of Campylobacter from patients and chicken, respectively. And membrane filter method with sheep blood agar was also used in both two cases. Isolates were indentified with PCR, PCR-RFLP, and biochemical test. And genotypes were determined with SmaI PFGE profile analysis.
RESULTS
A total of 13 Campylobacter strains(1.7%) were isolated from 856 stool specimens of 773 patients with diarrhea, nine isolates were C. jejuni and four were C. coli. All of 16 raw chickens were contaminated with Campylobacter spp., and both of C. jejuni and C. coli were detected from eight chickens. From the SmaI-digested PFGE profile analysis of nine C. jejuni strains and four C. coli strains isolated from patients, eight types and four types of PFGE profile were obtained, respectively. And 15 types and seven types of PFGE profile were obtained from 23 of C. jejuni and 11 of C. coli which strains were isolated from chicken samples, respectively. The several isolates showing the different PFGE patterns were detected in the same chicken. Three PFGE patterns of C. jejuni isolated from patients were observed in the chickens. One type of C. coli PFGE profiles of the patient's isolates were the same as that of chicken.
CONCLUSIONS
The prevalence of Campylobacter infection is not high compared to the other countries, but most of raw chickens are contaminated with Campylobacter spp. Several genotypes of C. jejuni and C. coli are contaminated in the single chicken. The PFGE patterns of some human isolates are the same as those of chicken so that human infection may be originated from the chicken. But the reason of low infection rate in human in spite of the very high contamination rate of chicken should be clarified in the near future