NONSURGICAL TRANSPLANTATION OF OESOPHAGOSTOMUM-DENTATUM TO RECIPIENT PIGS VIA RECTAL INTUBATION

This experiment was designed to evaluate a new transplantation method, which employs a non-invasive rather than a surgical technique for tra nsplanting Oesophagostomum dentatum worms to recipient pigs. Four grou ps of pigs were used. Group A (four pigs) served as a donor group, and these pigs were each inoculated with 6000 L(3) of O. dentatum. Groups B, C, and D (five pigs each) served as helminth naive recipient pigs. On Day 28 post inoculation, the donor pigs were slaughtered, and the worms recovered by an agar-gel technique. Within 3-4 h after slaughter of the donor animals, a mean of 357 worms (male/female = 1.0) were tr ansferred to each of the sedated recipient pigs via a PVC tube inserte d approximately 50 cm up into the rectum and colon descendens. The inf ection was then monitored by weekly faecal egg counts and by killing t he recipient pigs at Week 1 (group B), Week 2 (group C), and Week 3 (g roup D) post transplantation. The majority of the recovered worms were found in the proximal third of the colon, i.e. the normal predilectio n site of O. dentatum. The mean worm recovery for groups B and D was 8 5%, whereas from group C it was only 23%. The faecal egg counts were p ositive throughout the experiment, although low in group C at the time of slaughter 2 weeks post transplantation. The male/female ratios cha nged from an initial 1.0 to 1.5 in group C, whereas there was little o r no change in groups B and D. The reason for the deviating results in group C are obscure. This method is less traumatic to animals when co mpared with surgical transfer techniques, is rapid to perform, and wil l allow studies on a larger scale.