Comparação genotípica e fenotípica de isolados de Corynebacterium pseudotuberculosis de caprinos e ovinos do sertão de Pernambuco, Brasil

Abstract

The main purpose of this study was to compare genotypically samples of Corynebacterium pseudotuberculosis obtained from the abscesses of sheep and goats diagnosed with caseous lymphadenitis proceeding from the semi-arid region of Pernambuco, Brazil. The RFLP-PCR technique was used to fingerprint the genes rpoB and pld, with the restriction enzymes Hpy-Ch4 and MspI; and PstI and MspI applied, respectively. The banding pattern observed through eletrophoreses was similar in all samples for both genes studied, independently of the restriction enzyme utilized. The in vitro sensitivity profile was also analyzed by testing the samples with 14 different antimicrobials. Initially, the contents of the abscesses were cultivated in blood-agar and the isolated colonies obtained were identified using the API-Coryne biochemical identification kit (Bio-Merieux, France), and selecting Gram-positive and nitrate-negative samples, which were classified as Corynebacterium pseudotuberculosis. The disk diffusion technique was used to perform antibiogramsand the results showed that 96.8% of the samples were sensitive to chloramphenicol and ciprofloxacin; 93.5% were sensitive to norfloxacin and cefazolin; 90.3% to amoxicillin and tetracycline; 87.1% to sulfa-trimethoprim; 83.9% to orbifloxacin; 77.4% to ampicillin, lincomycin and penicillin; 32% to gentamicin; 12.9% to novobiocin and 9.7% to neomycin. It was also noted that 87.1% of the samples were resistant to novobiocin; 80.6% to neomycin; 41.9% to gentamicin; 19.3% to lincomycin; 16.1% to ampicillin, orbifloxacin and penicillin; 12.9% to sulfatrimethoprim; 6.4% to cefazolin, norfloxacin and amoxicillin, and 3.2% to ciprofloxacin, chloramphenicol and tetracycline. For all samples, with the exception of one, was found some degree of multiple resistances with 16% of them being multiresistant to approximately 50% of the antimicrobial drugs tested. Based on those results, it is possible to conclude that there is a phenotypic variation among the samples analyzed, which could be associated to one or more resistance genes. Thegenotypic results did not demonstrate any difference on the band fragmentation pattern among the samples when analyzing the genes pld and rpoB, regardless of the host species origin or geographic area, indicating a homogeneous genotypic profile of the infection in the region of study.