Application of the Mast resistotyping scheme to Campylobacter jejuni and C. coli.

The Mast resistotyping scheme was assessed with 228 strains of Campylobacter jejuni and C. coli from enteric infections in man and from a diverse selection of other sources (livestock, chickens and river water). Most (153 of 158) C. jejuni examined were of the three most common Penner (heat stable, HS) serotypes, HS1, HS2 and HS4 complex. Fourteen resistotypes were identified in the 158 strains of C. jejuni and 16 in the 70 isolates of C. coli. The predominant codes were 00 (44% of C. jejuni; 33% of C. coli) and 40 (21% of both species). The scheme was simple to use but reproducibility and interpretation of sensitivity zones--notably for fluorouracil, triphenyltetrazolium chloride and metronidazole--was occasionally problematic. Overall, resistotypes did not correlate with Penner HS serotypes or with three key genomic markers (ribotype, PFGE macrorestriction-type and fla-type). Although resistotyping offers a rapid means for distinguishing between some strains of C. jejuni and C. coli, discrimination for common resistotypes can be achieved only in combination with other typing methods.