| Title | Changes in antimicrobial resistance among faecal enterococci isolated from growing broilers prophylactically medicated with three commercial antimicrobials. | | Author(s) | Costa PM, Bica A, Vaz-Pires P, Bernardo F | | Institution | ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Largo Professor Abel Salazar, 2, 4099-003 Porto, Portugal; CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal. | | Source | Prev Vet Med 2009 Oct 10. | | Abstract | A controlled environment poultry house (1600m(2)) was divided into two separated compartments. Three hundred twenty chick containers (each containing 100 chicks) were randomly allocated to each compartment. Antimicrobial products were provided (via drinking water) to one broiler group in three different growth phases for prophylactic purposes: lincomycin associated with spectinomycin from day 1 to day 3, trimethoprim associated with sulfamethoxazole from day 19 to day 21, and tylosin from day 26 to day 28. Feed and faecal samples from both groups were obtained on days 0, 4, 9, 14, 18, 22, 25, 29 and 33. One sample of the drinking water and samples from the broiler house environment were obtained one day before bird placement. A maximum of 16 enterococci isolated from Kanamycin Aesculin Azide Agar were tested for resistance using the disk diffusion method. A high prevalence of resistance to drugs such as tetracycline, erythromycin and nitrofurantoin was detected in enterococcal isolates from medicated and unmedicated flocks. Resistance occurrence in the non-medicated group revealed a shift in resistance profiles with the gradual change of the initial strains, isolated from the day-old chicks' cloacal swabs, by others displaying a different phenotype. Resistance phenotypes obtained from faecal strains were correlated with those isolated from the farm environment and feeds. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19822372 |
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