PCR-BASED RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM (RFLP) ANALYSIS AND SEROTYPING OF CAMPYLOBACTER-JEJUNI ISOLATES FROM DIARRHEIC PATIENTS IN CHINA AND JAPAN

A molecular typing approach for Campylobacter jejuni was applied with restriction fragment length polymorphism (RFLP) analysis of a 702-bp P CR-amplified portion of the flagellin-A (flaA) gene. We analyzed a tot al of 179 strains, including 69 independent clinical isolates from dia rrheic patients in Japan, 85 isolates in China, and 25 heat-stable (HS ) serotype strains by Penner and Hennessy ((1980) J. Clin. Microbiol. 12, 732-737). Six AfaI, seven MboI, and five HaeIII RFLPs were found i n the 702-bp flaA segment from the 179 strains. Using a combination of these three enzymes, 25 separate RFLP groups were recognized. While 5 9 of 154 (38.3%) strains obtained in Japan and China were nontypeable by the HS antigenic scheme, all but two of 154 (98.7%) could be typed by RFLP typing. All 11 isolates of HS-19 strains, which are frequently isolated from Guillain-Barre syndrome (GBS) patients, showed an ident ical RFLP pattern (Cj-1), and Cj-1 consisted only of HS-19 strains. Th is suggests that the HS-19:Cj-1 strain is distinct among C. jejuni str ains. This molecular typing method provides a rapid and reliable typin g scheme for epidemiological studies of C. jejuni, and may also be use ful for the analysis of C. jejuni subtypes from GBS patients.