Salmonella entericain Commercial Swine Feed and Subsequent Isolation of Phenotypically and Genotypically Related Strains from Fecal Samples

Abstract

The purpose of this study was to determine the occurrence and genotypic relatedness of Salmonella enterica isolates recovered from feed and fecal samples in commercial swine production units. Of 275 feed samples, Salmonella was detected in 10 feed samples that originated from 8 of 36 (22.2%) barns, with a prevalence of 3.6% (10/275 samples). In fecal samples, a prevalence of 17.2% was found at the early finishing stage (1,180/6,880 samples), with a significant reduction in prevalence (7.4%) when pigs reached market age (392/5,321 samples). Of the 280 Salmonella isolates systematically selected for further characterization, 50% of the feed isolates and 55.3% of the isolates of fecal origin showed similar phenotypes based on antimicrobial resistance patterns and serogrouping. About 44% of the isolates were multidrug resistant. Pulsed-field gel electrophoresis (PFGE) genotyping grouped the 46 representative isolates into five genotypic clusters, of which four of the clusters consisted of genotypically related isolates recovered from feed and fecal samples. The occurrence of genotypically related and, in some cases, clonal strains, including multidrug-resistant isolates in commercially processed feed and fecal samples, suggests the high significance of commercial feed as a potential vehicle of Salmonella transmission.

Salmonella serovars isolated for the first time in Poland, 1995–2007

“…Thirteen of these first isolations were made only from human and 34 only from non-human sources. Five serovars, namely Salmonella Mississippi, Salmonella Hvittingfoss, Salmonella Isaszeg, Salmonella Lindern and Salmonella IV (11:z 4 ,z 24 :−) were isolated from both sources. The biochemical behaviour of all the strains was regular and Salmonella enterica subsp.…”

“…Animal feed is a recognized source of pathogenic microorganisms for animals [16]. It is still relatively common to find evidence of contamination of domestic and imported feed and animal-feed ingredients [17][18][19][20][21][22][23][24][25][26]. Salmonella can be isolated regularly from feedstuffs and feed ingredients, including both animal and vegetable proteins, such as soya, rape, palm kernel, rice bran and cottonseed.…”

Prevalence of Porcine Noroviruses, Molecular Characterization of Emerging Porcine Sapoviruses from Finisher Swine in the United States, and Unified Classification Scheme for Sapoviruses

“…Pig fecal samples were from a major time-nested longitudinal study of Salmonella infection in finisher pigs (32). Three different vertically integrated commercial swine production systems (BC1 to -3), located in North Carolina, were sampled during March to November 2009 and resulted in a total of 1,874 pig fecal specimens across all systems (see Table S1 in the supplemental material).…”

Review. Dairy farm management and production practices associated with the presence of Listeria monocytogenes in raw milk and beef

“…For instance, Mohammed et al (2009) found twice the incidence of L. monocytogenes in drinking troughs, feeders and cow beds (66%, 65%, and 55%, respectively) than in silage (30%). Although pathogen control procedures such as heat treatment or the addition of chemicals can be used in the feed manufacturing process, Molla et al (2010) strongly question the conventional wisdom that processed feed is not a source of bacterial contamination.…”