Use of pilocarpine-induced alimentary secretions to measure intestinal shedding of Salmonella enteritidis in chickens.

A technique has been developed that uses the parasympathomimetic drug pilocarpine to induce alimentary secretions in chickens for measuring local immune responses to Salmonella enteritidis strain SE6. A study was conducted to determine if these secretions could also be used to detect intestinal SE6 shedding. White leghorn chickens infected with 1 x 10(9) SE6 were samples weekly using cloacal swabs, and the isolation rates from these samples were compared with alimentary secretions induced by oral administration of phosphate-buffered saline followed 45 minutes later with an intraperitoneal injection of 5% pilocarpine. At 9 days postinfection, isolation rates from the alimentary secretions were significantly higher than isolation rates from the swabs, and by day 16 they were double those from the swabs. In separate small experiments, alimentary secretions induced by pilocarpine alone also had significantly more SE6 isolations than did cloacal swabs on two of three sampling times examined. Direct culture of feces resulted in numerically but not significantly greater SE6 isolations than did cloacal swabs on two of three sampling times. These results indicate that induced intestinal material is a better sample source than cloacal swabs for detecting S. enteritidis intestinal infections in chickens and could have many applications in intestinal pathogenesis research.