Use of Slide Agglutination Technique for Serogrouping of Campylobacter jejuni/coli Isolates from the Outbreaks and Sporadic Cases in Japan

In view of a necessity to have a national reference system for Campylobacter serotyping in Japan, 8 local institutes of public health have embarked upon a joint work to obtain a typing system to be used in Japan until the completion of an international system is developed. This paper describes the serotyping results of Campylobacter jejuni isolated from human subjects throughout Japan by a slide agglutination test developed by the Tokyo Metropolitan Research Laboratory of Public Health (TCK system). The 33 typing sera numbered TCK 1 through TCK 33 have successfully been used to type 282 strains (84.2%) out of 335 isolates from 37 outbreaks of C. jejuni gastroenteritis throughout Japan, leaving 53 strains (15.8%) untypable. Out of those strains, 242 reacted with only single serum, while 40 strains with 2 or more. In 14 outbreaks, all isolates from one outbreak were found to have the same serogroup, while 2 serograoups were detected in each of the 10 outbreaks and 3 or more in each of the 13 outbreaks. Out of 1, 064 strains isolated from sporadic cases of gastroenteritis, 714 (67.1%) were typed and 340 (32.0%) were nontypable. The remaining 10 strains were not typed since they deteriorated into a rough form. The most common serogroups include TCK 1 (12.8%), 20 (12.3%), 4 (8.2%), 7 (6.8%) and 24 (6.6%) and no geographical bias was noted in their distribution. The next common serogroups were TCK 26, 21, 6, 12, and 10. Ninety five out of 714 strains (13.3%) have reacted with more than one typing serum. On the basis of these results, the authors believe that this serotyping system will serve the purpose till the establishment of the international system.