Isolation and Characterization of <i>Campylobacter</i> Strains from Diarrheal Patients in Central and Suburban Bangkok, Thailand

Abstract

SUMMARY: 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 (58z) and C. coli (40z) are prevalent among diarrheal patients in Thailand.

A new variant of cytolethal distending toxin in a clinical isolate of Campylobacter hyointestinalis

“…The nucleotide sequence of the cdt gene cluster in C. hyointestinalis strain Ch022, an isolate from a patient with diarrhoea in Thailand (Samosornsuk et al, 2015), was analysed by genome walking. A 13 965 bp DNA sequence including the entire cdt gene cluster and its flanking regions was determined as described in Fig.…”

“…C. hyointestinalis strain Ch022, isolated from a diarrhoeal patient in Thailand (Samosornsuk et al, 2015), and C. jejuni strains 81-176 (Pickett et al, 1996) and K328 (Kabir et al, 2011) were used in this study. Campylobacter strains were grown on blood agar [blood agar base no.…”

“…Subsequently, this isolate was identified as C. hyointestinalis by 16S rRNA gene sequence analysis (Samosornsuk et al, 2015).…”

Multiplex PCR Assay for Identifi cation and Differentiation of Campylobacter jejuni and Campylobacter coli Isolates

“…However, the phenotypic differentiation is not always accurate. [7][8][9][10]16 To address this shortcoming we optimized a genetic method -the multiplex PCR -to identify the two species, which is more accurate and reliable than the phenotypic test. We used primers for detecting conservative genes: cadF -for all types of Campylobacter genus, hipO -for C. jejuni and asp for C. coli.…”

Campylobacter hyointestinalis Isolated from Pigs Produces Multiple Variants of Biologically Active Cytolethal Distending Toxin

“…Asakura et al have reported that cdt genes are ubiquitously present in C. jejuni, C. coli, and C. fetus and are highly homologous within species but less homologous among species (18; N. Hatanaka, unpublished). Based on these findings, a cdt gene-based multiplex PCR assay for the detection of C. jejuni, C. coli, and C. fetus has been developed (19) and utilized for the identification of these species from poultry and diarrheal patients (20,21). Furthermore, Kamei et al developed a cdtB gene-based PCR-restriction fragment length polymorphism (RFLP) assay for the detection and differentiation of 7 Campylobacter species, i.e., C. jejuni, C. coli, C. fetus, C. hyointestinalis, C. lari, C. helveticus, and C. upsaliensis, and successfully identified the species of 132 Campylobacter strains, failing to identify only 3 C. hyointestinalis strains (22).…”