Comparison of the Penner and Lior methods for serotyping Campylobacter spp.

We compared two Campylobacter serotyping systems by using 1,405 isolates of Campylobacter collected from human, animal, and environmental sources during epidemiologic investigations and special studies. We found 96.1% of isolates to be typable by the Penner method for heat-stable antigens, which involved the use of an indirect hemagglutination technique, and 92.1% of isolates to be typable by the Lior method for heat-labile antigens, which involved the use of a slide agglutination technique and absorbed antisera. Absorbed antisera were not required for the Penner method, making that method less difficult to implement. The Lior method was simpler to perform and gave more rapid results than did the Penner method. Cultures frequently reacted in multiple antisera with the Penner method, whereas multiple reactions were rare with the Lior method. Thus, results were easier to interpret with the Lior system. Strains of a single serotype in one system were sometimes found to be multiple serotypes in the other system; hence, the two methods have the potential to be complementary. Both systems were comparable in serotyping isolates from human and nonhuman sources and for evaluating the relationship of strains collected during outbreak investigations.