Comparison of a commercial test for serotyping heat-stable antigens of Campylobacter jejuni with genotyping by pulsed-field gel electrophoresis

A new commercial serotyping set based on heat-stable Penner's antigens was compared with pulsed-field gel electrophoresis (PFGE) with SmaI and SacII r estriction endonucleases. Among 50 isolates of Campylobacter jejuni from Fi nnish patients, which represented predominant PFGE patterns selected from i solates from sporadic cases and isolates associated with small outbreaks, 1 1 different serotypes were demonstrated from 43 typable isolates. Several P FGE patterns could be found within one serotype; on the other hand, several serotypes could be demonstrated within one PFGE type. Most isolates origin ated from sporadic cases; however, some isolates were epidemiologically ass ociated and showed identical serotypes and PFGE patterns. Although the new serotyping set would have been useful in the few epidemic cases studied, se veral isolates (14%) representing the major PFGE patterns remained untypabl e or gave weakly positive agglutination reactions only suggesting a plausib le serotype (18%). This might restrict the use of the novel serotyping set, at least in Finland.