Effects of tylosin administration on C-reactive protein concentration and carriage of Salmonella enterica in pigs
Kim HB, Singer RS, Borewicz K, White BA, Sreevatsan S, Johnson TJ, Espejo LA, Isaacson RE
To evaluate the effects of tylosin on C-reactive protein concentration, carriage of Salmonella enterica, and antimicrobial resistance genes in commercial pigs.
120 pigs on 2 commercial farms.
A cohort of sixty 10-week-old pigs in 4 pens/farm (15 pigs/pen) was randomly selected. Equal numbers of pigs were given feed containing tylosin (40 μg/g of feed) for 0, 6, or 12 weeks. C-reactive protein concentrations were measured, microbial culture for S enterica in feces was performed, and antimicrobial resistance genes in feces were quantified.
No significant associations were detected between C-reactive protein concentration or S enterica status and tylosin treatment. During the 12 weeks of tylosin administration, increased levels of 6 antimicrobial resistance genes did not occur.
CONCLUSIONS AND CLINICAL RELEVANCE:
Treatment of pigs with tylosin did not affect C-reactive protein concentration or reduce carriage or load of S enterica. There was no evidence that pigs receiving tylosin had increased carriage of the 6 antimicrobial resistance genes measured.
IMPACT FOR HUMAN MEDICINE:
S enterica is a public health concern. Use of the antimicrobial growth promoter tylosin did not pose a public health risk by means of increased carriage of S enterica.
American Journal of Veterinary Research 75:460-467