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Resumen Los objetivos de este trabajo fueron estudiar la sensibilidad antibiótica de aislamientos de Corynebacterium pseudotuberculosis procedentes de pequeños rumiantes e investigar la presencia de integrones que contienen genes de resistencia. Se estudiaron 15 aislamientos de diferentes fuentes por los métodos de difusión y dilución. Por el método de difusión, amoxicilina-clavulánico, ampicilina, cefotaxima, cefoxitina, ciprofloxacina, cloranfenicol, eritromicina, estreptomicina, gentamicina, imipenem, kanamicina, norfloxacina, penicilina, rifampicina, tetraciclina, trimetroprima-sulfametoxazol y vancomicina fueron activos frente al 100% de los aislamientos, mientras que amicacina presentó resultados variables. En los aislamientos que desarrollaron frente a amicacina se investigó la presencia de integrones de clase 1. El resultado fue negativo, sugiriendo la ausencia del integrón. Utilizando el método de dilución, los antibióticos más activos correspondieron a los grupos de cefalosporinas, gluco-péptidos, macrólidos, quinolonas y tetraciclinas. Se demostró menor actividad de p-lactámicos y aminoglucósidos. No se registró variabilidad en los perfiles antibióticos en los aislamientos procedentes de diferentes fuentes.

Abstract The aims of this work were to study the antibiotic susceptibility in Corynebacterium pseudotuberculosis isolated from small ruminants and to determine the presence of integrons that contain resistance genes. Fifteen isolates of different sources were analysed using the diffusion and the dilution methods. When the diffusion method was performed, amoxicillin-clavulanic, ampicillin, cefotaxime, cefoxitin, ciprofloxacin, chloramphenicol, erythromycin, streptomycin, gentamicin, imipenem, kanamycin, norfloxacin, penicillin, rifampicin, tetracycline, trimethoprim-sulfamethoxazole and vancomycin were effective against the 100% of isolates, while amikacin showed variable results. The isolates that were able to grow with amikacin, were studied in relation to the presence of integron class 1. The result was negative, suggesting the absence of integron. Using dilution method, the antibiotics belonging to the cephalosporin, glycopeptide, macrolide, quinolone, and tetracycline groups were the most active ones for the C. pseudotuberculosis biovar ovis isolates. Less activity of p-lactam and aminoglycosides were observed. There was no observation of variability in the antibiotic patterns in the strains coming from different sources.

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The aims of this work were to study the antibiotic susceptibility in Corynebacterium pseudotuberculosis isolated from small ruminants and to determine the presence of integrons that contain resistance genes. Fifteen isolates of different sources were analysed using the diffusion and the dilution methods. When the diffusion method was performed, amoxicillin-clavulanic, ampicillin, cefotaxime, cefoxitin, ciprofloxacin, chloramphenicol, erythromycin, streptomycin, gentamicin, imipenem, kanamycin, norfloxacin, penicillin, rifampicin, tetracycline, trimethoprim-sulfamethoxazole and vancomycin were effective against the 100% of isolates, while amikacin showed variable results. The isolates that were able to grow with amikacin, were studied in relation to the presence of integron class1. The result was negative, suggesting the absence of integron. Using dilution method, the antibiotics belonging to the cephalosporin, glycopeptide, macrolide, quinolone, and tetracycline groups were the most active ones for the C.pseudotuberculosis biovar ovis isolates. Less activity of ß-lactam and aminoglycosides were observed. There was no observation of variability in the antibiotic patterns in the strains coming from different sources.

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Introdução: corynebacterium pseudotuberculosis é uma bactéria com importância em medicina veterinária por ser o agente etiológico da Linfadenite Caseosa (LC) em pequenos ruminantes. A doença leva a perdas econômicas devido a condenação de carcaças, diminuição de produtividade e redução do valor comercial do couro dos animais acometidos. O tratamento da doença é pouco eficaz, pois os agentes antimicrobianos não conseguem atravessar a barreira dos granulomas, mas tem sido proposta a inoculação intracapsular de antibióticos como tratamento e como medida de prevenção de contaminação ambiental. Objetivo: devido a esse fato, o presente estudo teve como objetivo avaliar a sensibilidade in vitro de isolados clínicos de Corynebacterium pseudotuberculosis isolados de animais da região Centro-Norte do estado da Bahia. Metodologia: foram retirados material de granulomas de 11 animais de uma fazenda na região acima mencionada, e as bactérias foram isoladas a partir desse material. Esses isolados então foram submetidos a metodologia de difusão em disco de ágar utilizando-se discos impregnados com doze antibióticos diferentes. Resultados: 90,9% (10/11) dos isolados foram resistentes a oxacilina. Com relação à sensibilidade, 100% dos isolados foram sensíveis a ampicilina, amicacina, amoxicilina, cefalotina, ceftriaxona, ciprofloxacina, enrofloxacina, neomicina e penicilina, enquanto 90,9% destes apresentaram sensibilidade a bactericina e doxiciclina. Conclusão: pode-se concluir que os isolados de C. pseudotuberculosis da região estudada apresentam sensibilidade a diversos antibióticos, o que pode facilitar na escolha de um antimicrobiano com menor toxicidade para fins de tratamento com inoculação intracapsular do medicamento.

Background: corynebacterium pseudotuberculosisis important bacteria in veterinary medicine because it is the Etiologic Agent of Caseous Lymphadenitis (CL) in small ruminants. The disease leads to economic losses due to condemnation of carcasses, productivity decrease and leather commercial value reduction of affected animals affected. The treatment of the disease is not very effective, because antimicrobial agents cannot cross the barrier of granulomas, but it has been proposed the intracapsular inoculation of antibiotics as treatment and as a measure of prevention of environmental contamination. Objective: due to this fact, the present study aimed to evaluate the in vitro susceptibility of clinical isolates of Corynebacterium pseudotuberculosis isolated from animals in the North Central region of the State of Bahia. Methodology: granuloma material were removed from 11 animals from a farm in the above mentioned area, and the bacteria were isolated from this material. These isolated bacteria were then subjected to disk diffusion method of agar using disks impregnated with twelve different antibiotics. Results: 90,9% (10/11) the isolated bacteria were resistant to oxacillin.With respect to sensitivity, 100% of the isolates bacteria were susceptible to amikacin, ampicillin, amoxicillin, cephalotin, ceftriaxone, ciprofloxacin, enrofloxacin, neomycin and penicillin, while 90.9% of these showed sensitivity to bacitracin and doxycycline. Conclusion: it can be concluded that the isolated bacteria of C. pseudotuberculosis from the region studied present sensitivity to different antibiotics, which can facilitate the choice of a less toxic antimicrobial for treating with intracapsular inoculation of the medicine.

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Resumo: O ensaio imunoenzimático (ELISA) foi utilizado para mensurar os níveis de anticorpos contra a exotoxina, linfadenina e os antigenos solúveis extraídos por SDS e por ultr-som do Corynebacterium pseudotuberculosis, nos soros de caprinos normais e naturalmente infectados. Nossos resultados indicam a exotoxina e a linfadenina como os melhores antigenos, dentre os estudados, para detectar anticorpos específicos contra o Corynebacterium pseudotuberculosis (au)

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