Detection of the toxin gene in sheep with and without small intestinal adenocarcinoma.

To determine if presence of the toxin () gene, a molecular marker of colonic carriage of entertoxigenic (ETBF) in humans, was associated with a finding of small intestinal adenocarcinomas (SIA) in sheep in New Zealand. Samples of jejunal tissue were collected from the site of tumours and from grossly normal adjacent tissue in 20 sheep, in different consignments, diagnosed with SIA based on gross examination of viscera following slaughter. Two jejunal samples were also collected from a control sheep in the same consignment that had no gross evidence of SIA. A PCR assay was used to detect the presence of the gene in the samples. Of the sheep with SIA, the gene was amplified from one or both samples from 7/20 (35%) sheep, and in sheep that had no gross evidence of SIA the gene was amplified from at least one sample in 11/20 (55%) sheep (RR 0.61; 95% CI = 0.30-1.25; p = 0.34). Of 11 positive samples analysed, ETBF subtype -1 was detected in one, -2 was detected in 10, and none were -3. There was a high prevalence of detection of the gene in both SIA-affected and non-affected sheep, but there was no apparent association between carriage of ETBF, evidenced by detection of the gene, and the presence of SIA. ETBF are increasingly implicated in the aetiology of human colorectal cancer, raising the possibility that sheep may provide a zoonotic reservoir of this potentially carcinogenic bacterium. : toxin; ETBF: Enterotoxigenic ; SIA: Small intestinal adenocarcinoma.