Resumo

Corynebacterium pseudotuberculosis, a gram-positive bacillus, is the etiological agent of caseous lymphadenitis, a chronic infection characterized by formation of granulomas in sheep and goats. This study aimed to compare fourteen different wild samples of Corynebacterium pseudotuberculosis isolated from superficial granulomas of goats from the state of Bahia with a naturally attenuated strain (T1), and to compare the use of two culture media in the disk diffusion test sensitivity to antimicrobials, as well as to evaluate the resistance profile of these wild samples and T1 strain. The biochemical characterization was tested by production of urease and catalase and fermentation of glucose, sucrose, lactose and maltose. All samples studied were positive for urease, glucose, catalase, and negative for lactose and sucrose. Only 20% of the wild samples tested were positive for maltose. Gentamicin, ciprofloxacin, penicillin G, tetracycline, norfloxacin, ampicillin and chloramphenicol were used to study the profile of resistance. Samples were plated in BHI agar and Müeller-Hinton agar supplemented with 5% sheep blood. A Staphylococcus aureus strain (ATCC 25923) was used as control test. All samples were sensitive to all antibiotics tested, in both media used. After statistical analysis by the software SPSS 15.0, using nonparametric Mann-Whitney test, was possible to demonstrate that there was a statistically significant difference between the diameters of inhibition zones of bacterial growth in two culture media for the antimicrobial agents gentamicin, ciprofloxacin, penicillin G, tetracycline, and norfloxacin. However, all the inhibition areas had larger diameters than those obtained with Staphylococcus aureus strain used as control, leading to the conclusion that both media can be used to evaluate the profile of resistance.