Coinfection of enteric Helicobacter spp. and Campylobacter spp. in cats

During a 6-year period, 64 of 227 commercially reared cats had microaerobic bacteria isolated from their feces. All the isolates were initially identi fied as Campylobacter-like organisms based on biochemical and phenotypic ch aracteristics. DNA extractions from 51 of these isolates were subjected to PCR using primers specific for Helicobacter spp. and Campylobacter spp. Of the isolates, 92% (47 of 51 isolates) were positive for Campylobacter spp,, 41% (21 of 51 isolates) were positive for Helicobacter spp., 33% (17 of 51 isolates) were positive for both genera, 59% (30 of 51 isolates) were posi tive only for Campylobacter spp., and 8% (4 of 51) were positive only for H elicobacter spp. Sixteen of the 47 Campylobacter-positive cultures were pos itive for more than one Campylobacter. spp. Based on a species-specific PCR assay, 83% of the isolates were identified as Campylobacter helveticus, 47 % of the isolates were identified as Campylobacter upsaliensis, and 6% of t he isolates were classified as Campylobacter jejuni. The 1.2-kb PCR product s of the 16S rRNA genes of 19 Helicobacter species isolates were subjected to restriction fragment length polymorphism (RFLP) analysis. Of the five di fferent RFLP patterns obtained, two clustered with Helicobacter ("Flexispir a") taxon 8, one clustered with Helicobacter bilis, one clustered with Heli cobacter canis, and the remaining pattern was closely related to a novel He licobacter sp. strain isolated from a woodchuck. The sequence data for the 16S rRNA genes of 10 Helicobacter spp. validated the RFLP-based identificat ion of these isolates. This study demonstrated that biochemical and phenoty pic characteristics of microaerobic organisms in cat feces were insufficien t to characterize mixed Helicobacter and Campylobacter infections. Molecula r structure-based diagnostics using genus- and species-specific PCR, RFLP a nalysis, and 16S rRNA sequence analysis enabled the identification of multi ple microaerobic species in individual animals. The clinical relevance of e nteric Helicobacter and Campylobacter coinfection in cats will require furt her studies.