Prevalence of virulence markers of enteric Campylobacter in France and Tunisia.

Forty-nine strains of Campylobacter jejuni and C. coli were isolated from the stools of 49 patients clinically documented for diarrhoea and fever, and living either in the Paris metropolitan area (30) or in the Tunis area (19). The strains were identified biotyped, serotyped and studied for association with HeLa cells and the ability to elongate Chinese ovary cells (CHO). The C. jejuni biotype I was more frequent among Tunisian strains and the C. jejuni biotype II was more frequent among French strains. Twenty-four strains associated with HeLa cells (A phenotype) and 21 elongated CHO (E phenotype). These 2 phenotypes were independently distributed in individual strains and were not related to the biotypes. We defined 4 pathovars according to the presence (A and E) or absence (a and e) of these 2 markers. The prevalence of the 4 pathovars was not correlated with the origin of the strain. The lack of a virulence marker (phenotype a/e) was correlated with the lack of clinical signs of diarrhoea and fever (p = 4 x 10(-5)). We concluded that at least 1 of the 2 in vitro virulence markers is related to the pathogenicity of the strains in the humans.