ABSTRACT
Campylobacter jejuni and Campylobacter coli are zoonotic bacteria which are frequently associated with human diarrhea. Sharing of the cytolethal distending toxin [cdt] genes in Campylobacter is common and is considered species specific. In this study we focused on detecting the presence of cdt gene in C. jejuni and C. coli isolated from broilers, turkeys and quails of Iran. Cecal samples were randomly collected from 240 broiler chickens, 100 meat type turkeys and 100 quails after slaughtering. We used PCR as a method for detecting cdt genes. In broilers, 93% of 58 C jejuni positive samples possessed cdt gene and in all cases the three different subunits of cdt genes were present. However, only 56% of 14 C. coli isolates in broilers had contained cdt genes, while one fourth having all three subunits present. In turkeys, around 65% of 34 C. jejuni positive samples had cdt gene present with 38% possessing all three subunits of cdt genes. But all 5 C. coli isolates had all three subunits cdt gene. In quails, 67% of 30 C. jejuni positive samples were identified by cdt gene, 20% of those possessed all three gene subunits. On the other hand, all 28 C. coli isolates of quails had cdt gene present while 36% of those held all three gene subunits. Our data is indicating the isolation, culture and cdt PCR amplification approaches in this study seemed to be efficient. However, the presence of different variation of Campylobacter cdt gene types in our sample isolates signifies the necessity of further functional gene studies to elucidate which gene type combinations result in encoding effective toxins
ABSTRACT
Campylobacteriosis is one of the most common bacterial intestinal disorders of humans in many countries. A wide range of domestic and wild bird species have been identified as natural reservoirs. The aim of this study was to determine the Campylobacter spp from pet birds and screen the determined Campylobacters for presence of virulence cytolethal distending toxin [cdt] genes. A total of 660 fecal samples from 32 different species of pet birds were taken and examined for detection of Campylobacter spp. and were investigated for presence of cdt genes. All the samples were collected from clinically healthy birds that were kept in cage, zoological parks, and/ or in zoo of Tehran, the capital of Iran. RESULTS: In total, 20 thermophilic Campylobacter were detected from 8 different avian species. From 20 confirmed Campylobacter spp., 16 samples [80%] were C.jejuni positive and 4 [20%] were C. coli in species-specific PCR test. Furthermore, out of 20 detected Campylobacter, 13 [65%] harbored the various subunits of cdt A, cdtB and cdtC genes, and 7 [35%] were negative for all tested cdt genes. Our findings indicate that the carriage rate of Campylobacter in different species of cage and/or in zoo birds is high and confirm that cdt genes may frequently be present in Campylobacter spp.