Isolation and Characterization of Campylobacter Strains from Diarrheal Patients in Central and Suburban Bangkok, Thailand.

Campylobacter-induced diarrhea is increasingly recognized worldwide. However, little information is available regarding the Campylobacter strains associated with diarrheal patients in Thailand. In this study, we attempted to isolate Campylobacter strains from diarrheal patients in Thailand and to characterize the species using a cytolethal distending toxin (cdt) gene-based C. jejuni, C. coli, and C. fetus-specific multiplex PCR assay. Campylobacter species were also confirmed using 16S rRNA gene sequencing and hipO gene detection. From 2,500 diarrheal stool specimens, 76 Campylobacter-like organisms were isolated and identified via conventional culture methods. Among these 76 organisms, 73 were identified as Campylobacter species (43 C. jejuni, 29 C. coli, and 1 C. fetus) via multiplex PCR, whereas 3 remained unidentified. Two Campylobacter-like organisms yielded 2 amplicons corresponding to cdt genes from C. jejuni and C. coli. Subsequently, C. jejuni and C. coli were reisolated from each sample. The third isolate was identified as C. hyointestinalis via 16S rRNA gene sequencing. To our knowledge, this is the first report on the isolation of C. hyointestinalis from a diarrheal patient in Thailand. These data indicate that C. jejuni (58%) and C. coli (40%) are prevalent among diarrheal patients in Thailand.