Resumo

Caseous lymphadenitis is an infectious disease of sheep and goats caused by Corynebacterium pseudotuberculosis and characterized by abscesses in superficial and visceral lymph nodes. This pathogen has also been isolated from several species, including pigs, buffaloes, deers, porcupines, llamas, camels and rarely humans. C. pseudotuberculosis strains isolated from sheep and goats have been shown to be very difficult to type by the existing methods. Thus, the aim of this study was to evaluate the potential of the Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) as a tool for molecular typing of C. pseudotuberculosis strains isolated from Minas Gerais State, Brazil. One hundred and twenty eitght strains of C. pseudotuberculosis were isolated from lesions suggestive of caseous lymphadenitis collected from sheep at the slaughterhouse. The sheep were from 24 flocks in 13 municipalities of the Minas Gerais State. Species identification of the isolates were performed by routine biochemical tests and pld PCR. Fingerprint was performed by RAPD using ERIC-1R, ERIC-2 and ERIC-1R+ERIC-2 primers. Seventeen different genotypes were generated by ERIC 1-PCR, 21 genotypes by ERIC 2-PCR and another 21 genotypes by ERIC 1+2-PCR. The Hunter and Gaston Discriminatory Index (HGDI) found for ERIC 1, ERIC 2, ERIC 1+2 PCR were 0.69, 0.87, and 0.84, respectively. For all assays, ERIC-PCR indicated that the majority of the herds showed at most three different genotypes, however a few flocks showed between four and nine genotypes per flock. Our results show that ERIC – PCR has good discriminatory power and many advantages over other DNA-based typing methods, making it a useful tool to discriminate C. pseudotuberculosis isolates.