Field trial evaluating the influence of prophylactic and therapeutic antimicrobial administration on antimicrobial resistance of fecal Escherichia coli in dairy calves.
Appl Environ Microbiol
; 72(6): 3872-8, 2006 Jun.
Article
em En
| MEDLINE
| ID: mdl-16751491
ABSTRACT
The objective of this study was to describe the influence of in-feed and therapeutic antimicrobials on resistance in commensal fecal Escherichia coli isolated from preweaned calves. Four groups of 30, day-old calf-ranch calves were enrolled and raised until 4 weeks of age. Groups 1 to 3 were raised without antimicrobials in the feed. Group 1 was isolated from the other groups and received no antimicrobial therapy. Group 2 was housed on the calf ranch and did not receive antimicrobial therapy, whereas groups 3 and 4 could be treated with antimicrobials. Group 4 was fed neomycin and tetracycline HCl in the milk replacer. Fecal samples were collected from calves on days 1, 14, and 28. Three E. coli isolates per sample were evaluated for susceptibility to 12 antimicrobials. Cluster analysis was used to group isolates having similar susceptibility patterns. Cumulative logistic regression was used to evaluate factors associated with increasing levels of multiple antimicrobial resistance. In-feed antimicrobials were associated with higher levels of multiple antimicrobial resistance in fecal E. coli.f In calves not receiving in-feed antimicrobials, older calves had higher levels of resistance compared to day-old calves. Individual antimicrobial therapy increased resistance in these calves but appeared to be transient. There was no environmental influence on resistance in E. coli populations among study groups.
Texto completo:
1
Base de dados:
MEDLINE
Métodos Terapêuticos e Terapias MTCI:
Plantas_medicinales
Assunto principal:
Indústria de Laticínios
/
Farmacorresistência Bacteriana
/
Escherichia coli
/
Fezes
Idioma:
En
Revista:
Appl Environ Microbiol
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Estados Unidos