SEROTYPING SCHEME FOR CAMPYLOBACTER-JEJUNI AND CAMPYLOBACTER-COLI BASED ON DIRECT AGGLUTINATION OF HEAT-STABLE ANTIGENS

Campylobacter is now the most frequently reported cause of gastrointes tinal disease in England and Wales, yet few isolates are characterized beyond the genus level. The majority of isolates are Campylobacter je juni (90%), with most of the remainder being Campylobacter coli. We de scribe an adaptation pf the Penner serotyping scheme in which passive hemagglutination has been replaced by detection of heat-stable antigen s by direct bacterial agglutination; absorbed antisera are used,where appropriate. This scheme has been used to type 2,407 C. jejuni samples and 182 C. coli samples isolated in Wales between April 1996 and Marc h 1997. Forty-seven C. jejuni serotypes were identified, with the 10 m ost prevalent serotypes accounting for 53% of the isolates tested; 19% of the isolates were untypeable. Only fifteen C. call serotypes were identified, with three serotypes accounting for 69% of the isolates. T his scheme provides a baseline for epidemiological studies of C. jejun i and C. coli.