Utilização de antimicrobianos em galinhas de postura e avaliação do perfil de resistência de micro-organismos isolados da casca dos ovos

Abstract

To assess the presence of Salmonella spp. and Enterococcus spp. on eggshells, from hens treated with antimicrobials in the diet and to evaluate the resistance profile of these micro-organisms, 450 laying hens were used, raised in 26 days, including the day zero, five-day of treatment of the animals and 20 days for evaluations of the depletion period. The treatments were defined according to the drug administered to the diet of birds, were the following: control group and groups of chickens treated with doxycycline, lincomycin, oxytetracycline and enrofloxacin. For each organism studied, six replications were collected composed of a pool of five eggs per treatment on days zero, three, six, 15 and 25. The results of the search for Enterococcus spp. demonstrated that this micro-organism is present in high frequency in the eggshell, unlike Salmonella spp. which was not isolated from any sample. Among the 150 samples analyzed, 97.3% had a count for Enterococcus spp. and no significant differences were observed (p> 0.05) between the treatments. The assessment of Enterococcus spp sensitivity profile from the eggshells has demonstrated the existence of bacterial resistance to the four classes of antimicrobials tested regardless of treatment of birds.