Resistência a antibióticos em bactérias comensais de bovino de leite

• Autor(a) principal: Costa, Leonardo Emanuel de Oliveira
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5338
• topic: Antibióticos; Diversidade genética; Rúmen; Fezes; Bovino; RAPD; Antibiotics; Genetic diversity; Rumen; Feces; Bovine; RAPD; CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA MOLECULAR E DE MICROORGANISMOS

Ninety seven bacteria from the rumen and eighty seven ones from the feces were isolated from three dairy cows, feeding ration (24% protein) and corn ensilage. The resistance of the isolates to antibiotics were evaluated by using the agar dilution procedure for the following antimicrobials: nalidixic acid (NAL), ampicillin (AMP), chloramphenicol (CHL), erythromycin (ERY), streptomycin (STR), penicillin (PEN) and tetracycline (TET). The genetic diversity of 29 isolates from the rumen and 28 isolates from the feces were evaluated by Randomly Amplified Polymorphic DNA (RAPD). Approximately fifty seven percent isolates were obtained from animal one, thirteen percent from animal two, and twenty nine percent from animal three. The percent isolates obtained from feces were 62.1; 10.3; 27.6 for animal one, two and three, respectively. Considering all rumen isolates, the percent isolates resistant to the antimicrobial under test were: NAL 100 %; AMP 59.8 %; CHL 3.1 %; ERY 21.6 %; SRT 10.3 %; PEN 97.9 %; and TET 78.3 %. The overall resistance of the isolates from the feces were: NAL 100 %; AMP 54.0 %; ERY 20.7 %; STR 2.3 %; PEN 96.5 %; and TET 32.2 %. No isolates from the rumen or feces were simultaneously resistant to all antibiotics. The rumen isolates presenting the highest number of resistance marks were simultaneously resistant to six antibiotics, whereas the feces isolates were simultaneously resistant to five antibiotics. Among the rumen isolates showing six or five marks, neither one was resistant to chloramphenicol. Most isolates showing four marks were simultaneously resistant to the nalidixic acid, ampicillin, penicillin and tetracycline, whereas most isolates showing three marks were resistant to the nalidixic acid, ampicillin and penicillin. Those data suggest the profile resistant of the isolates from the rumen to be related to the resistance pattern of the isolates from the feces, relative to nalidixic acid, ampicillin, erythromycin, penicillin and tetracycline. The values of the genetic distance for rumen isolates ranged from 58% to 100%, therefore indicating high genetic diversity among those isolates. The values of the genetic distance among the feces isolates ranged from 16% to 96%, so indicating a high genetic diversity among isolates, as being those values lower, compared to rumen isolates.