Effects of cold stress on the antimicrobial drug resistance of Escherichia coli of the intestinal flora of swine.
Faecal samples were initially collected from pigs of different age groups, over periods considered to be seasonally normal and stable (baseline), and during times in which drastic drops in environmental temperature (cold stress) occurred. Baseline bacterial resistance to ampicillin and tetracycline were significantly higher (P < 0.05) in younger than in older pigs. Also, when animals were exposed to excessively cold conditions, there was a significant (P < 0.05) increase in ampicillin and tetracycline resistance in Escherichia coli for animals of all age groups. These results may indicate that factors other than feeding or use of antibiotics may play a role in establishing or maintaining the antibiotic resistance microflora of pigs, especially in those operations where animals are maintained outdoors, with minimal protection against extreme weather conditions.
Moro
M H
MH
Department of Microbiology, Immunology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, USA.
Beran
G W
GW
Hoffman
L J
LJ
Griffith
R W
RW
D000367:Age Factors; D000667:Ampicillin / Q000494:pharmacology; D000821:Animal Feed; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology; D003080:Cold Temperature; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology; D005243:Feces / Q000382:microbiology; D007422:Intestines / Q000382:microbiology*; D013412:Sulfadimethoxine / Q000494:pharmacology; D013552:Swine; D013752:Tetracycline / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D013412:Sulfadimethoxine; D000667:Ampicillin; C053503:ceftiofur; D013752:Tetracycline