Serotyping and biotyping of Campylobacter jejuni and Campylobacter coli from sporadic cases and outbreaks in Norway.

Of 172 thermophilic campylobacters isolated from human cases of gastroenteritis in Norway, 149 (86.6%) were classified as Campylobacter jejuni, whereas 23 isolates (13.4%) belonged to Campylobacter coli. C. jejuni biotype 1 comprised 66.3% and C. jejuni biotype 2 comprised 20.3% of the total number. Using 50 unabsorbed antisera, we were able to serotype 109 (80.1%) of 136 campylobacters on the basis of heat-stable antigens identified by means of passive hemagglutination. The typable strains fell into 36 different serotypes. A large proportion of the strains were isolated from travellers returning from abroad, a state of affairs which may have influenced the serotype and biotype distribution. Two family outbreaks were found to be caused by a bio-serotype common to all diseased members of the particular families. A third family outbreak and an outbreak among employees at a poultry processing plant each involved two distinct strains.