Detection of salmonella infection in herds by examination of slurry.

Abstract

An examination was carried out on the slurry system of the Animal Quarantine Service for 9 months to find the degree of contamination with Salmonella. Ready-made tampons were placed in the slurry for 5 to 7 days and submitted for detection of Salmonella. Tampons and samples of settled sludge were collected about two times a month at fixed sites along the slurry system. Salmonella organisms were recovered from 80 (62.5%) of 128 tampons, and also from 40 (34.8%) of 115 samples of settled sludge. The serovars isolated were S. cerro, S. newport, S. muenster, S. stanley, S. heidelberg, S. infantis, S. drypool, S. typhimurium, S. panama and S. arizonae (61:k:1, 5, 7). Seventy-one (98.6%) of 72 samples of slurry from which Salmonella organisms had been isolated by the tampon method contained less than 100 organisms as most probable number (MPN) per 100 ml. Thirty-four (91.9%) of 37 samples of settled sludge contained these organisms at the rate of less than 100/100 ml. Further examination was carried out on the slurry of pits and gutters beside animal houses and kennel during a period of two months when a large number of animals were put into quarantine. As a result, the states of Salmonella contamination could be clarified in each animal house. The tampon method is simple, inexpensive and reliable for the isolation of Salmonella organisms from the slurry which contains less than 1 organism 100 ml, as compared with such method of examination for fecal samples from many individual animals and a large quantity of slurry.