Effects of tylosin administration on C-reactive protein concentration and carriage of Salmonella enterica in pigs.
OBJECTIVE
To evaluate the effects of tylosin on C-reactive protein concentration, carriage of Salmonella enterica, and antimicrobial resistance genes in commercial pigs.


METHODS
120 pigs on 2 commercial farms.


METHODS
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.


RESULTS
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
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.


CONCLUSIONS
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.
Department of Veterinary and Biomedical Science, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108.
Hyeun Bum
HB
Kim
Randall S
RS
Singer
Klaudyna
K
Borewicz
Bryan A
BA
White
Srinand
S
Sreevatsan
Timothy J
TJ
Johnson
Luis A
LA
Espejo
Richard E
RE
Isaacson
D000704:Analysis of Variance; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002097:C-Reactive Protein / Q000378:metabolism*; D015331:Cohort Studies; D024881:Drug Resistance, Bacterial / Q000187:drug effects* / Q000235:genetics; D005243:Feces / Q000737:chemistry; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D016015:Logistic Models; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D012481:Salmonella Infections, Animal / Q000188:drug therapy*; D019779:Salmonella enterica / Q000187:drug effects*; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy*; D015645:Tylosin / Q000008:administration & dosage*
D000900:Anti-Bacterial Agents; D002097:C-Reactive Protein; D015645:Tylosin