Location: Meat Safety & Quality ResearchTitle: Effect of lysozyme or antibiotics on fecal zoonotic pathogens in nursery pigs Author
|Wells, James - Jim|
|Kalchayanand, Norasak - Nor|
|Kim, M - Former ARS Employee|
Submitted to: Journal of Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2015
Publication Date: 6/1/2015
Publication URL: http://handle.nal.usda.gov/10113/60934
Citation: Wells, J., Berry, E.D., Kalchayanand, N., Rempel, L.A., Kim, M., Oliver, W.T. 2015. Effect of lysozyme or antibiotics on fecal zoonotic pathogens in nursery pigs. Journal of Applied Microbiology. 118:1489-1497.
Interpretive Summary: Antibiotics have been utilized in animal feeds for more than 50 years to improve performance. However, the use of antibiotics in animal feeds has been questioned extensively in recent years. Recently weaned piglets have benefited from antibiotics in the nursery diet, and the need for an alternative by producers is greatest for these young pigs. Lysozyme is an enzyme with antimicrobial activity and previous research indicated that lysozyme improved animal performance. In nursery swine, Campylobacter are pathogens excreted in the feces, and dietary lysozyme reduced prevalence of this pathogen in feces nearly 50% when compared to piglets fed diets without and with antibiotics. Lysozyme appears to be a natural growth promoter that can be supplemented to the nursery piglet diet and also can decrease shedding of Campylobacter in the feces when piglets are most susceptible to colonization.
Technical Abstract: The objective of this study was to determine the effect of lysozyme and antibiotics on zoonotic pathogen shedding in feces from nursery pigs housed without and with an indirect disease challenge. Two replicates of 600 pigs each were weaned and randomly assigned to one of 24 pens in either a nursery room that had been fully disinfected or a nursery room left unclean. Pigs were randomly assigned to control diet (Control), control diet + antibiotics (Antibiotic; chlortetracycline and tiamulin), or control diet + lysozyme (Lysozyme; 100 mg/kg diet). Rectal swab samples were collected on d 0 and 28 of treatment, and enriched and cultured for Campylobacter spp. and shigatoxigenic Escherichia coli. Enrichments from rectal swab samples also were analyzed for presence of enterohemorrhagic E. coli (EHEC) virulence genes (hlyA, eae, stx1, and stx2). Room hygiene had little effect on d 28 results, except the percentage positives for hlyA were greater and for eae were less in the unclean rooms. Percentage of samples culture positive for Campylobacter spp. was lowest for lysozyme diets, but similar for control and antibiotic diets (43.2, 83.7, and 84.8.respectively; P<0.01). Diet had little effect on the EHEC virulence genes hlyA or eae (P>0.1), but there was a tendency for fewer samples positive for stx1/stx2 in antibiotic or lysozyme diet groups compared to control diet (5.8, 1.2, and 2.1%, respectively; P<0.07). The specific STEC types tested were rarely detected. Thus, lysozyme in the diet can reduce fecal shedding of Campylobacter spp. from nursery swine.