Serotypes and typability of Campylobacter jejuni and Campylobacter coli isolated from poultry products

Campylobacter infection is one of the most common bacterial enteric pathoge ns. Campylobacter jejuni and Campylobacter coli infections are mostly food- and waterborne and especially poultry is often assumed to be an important source. The heat-stable serotyping system (the 'Penner' scheme) was used to study the serotype distribution of C. jejuni and C. coli isolated from dif ferent food products of poultry origin sampled from retail outlets in Denma rk. A total of 156 isolates were serotyped, 85% of these were C. jejuni and 15% were C. coli. The most common C. jejuni serotypes were O:2 (30%), O:1, 44 (12%) and the O:4-complex (8%). O:46 was the most frequent serotype amon g C. coli isolates. These serotypes are also common among Danish clinical i solates and isolates from broiler chickens and cattle. Differences in serot ype distribution were seen for different kinds of poultry products. Isolate s from chicken products covered a large selection of serotypes. In contrast , the majority of the isolates from other product groups (turkey, poussin, wild birds) were concentrated on 1-3 serotypes. Using the standard procedur e for antigen preparation and serotyping, 25 of the 156 strains (16%) were nontypable. This rate of nontypable isolates is significantly higher than e xperienced for isolates from other sources than food products, i.e faecal s amples from animals and humans. Subculturing and re-typing of the nontypabl e isolates improved the typability. After two, five and 10 subcultures 16, six and one isolate became typable, respectively. Only three isolates (2%) remained nontypable after 10 subcultures. (C) 1999 Elsevier Science B.V. Al l rights reserved.