Author(s): PACHECO, L. G. C.; PENA, R. R.; CASTRO, T. L. P.; DORELLA, F. A.; BAHIA, R. C.; CARMINATI, R.; FROTA, M. N. L.; OLIVEIRA, S. C.; MEYER, R.; ALVES, F. S. F.; MIYOSHI, A.; AZEVEDO, V.

Summary: Abstract: Corynebacterium pseudotuberculosis is the aetiological agent of caseous lymphadenitis (CLA), a debilitating disease of sheep and goats. Accurate diagnosis of CLA primarily relies on microbiological examination, followed by biochemical identification of isolates. In an effort to facilitate C. pseudotuberculosis detection, a multiplex PCR (mPCR) assay was developed targeting three genes of this bacterium: the 16S rRNA gene, rpoB and pld. This method allowed efficient identification of 40 isolates of this bacterium that had been identified previously by biochemical testing. Analysis of taxonomically related species did not generate the C. pseudotuberculosis mPCR amplification profile, thereby demonstrating the assay's specificity. As little as 1 pg of C. pseudotuberculosis genomic DNA was detected by this mPCR assay, demonstrating the sensitivity of the method. The detection limit in clinical samples was estimated to be 103 c.f.u. C. pseudotuberculosis could be detected directly in pus samples from infected sheep and goats (n=56) with a high diagnostic sensitivity (94.6 %). The developed assay significantly improves rapid C. pseudotuberculosis detection and could supersede bacteriological culture for microbiological and epidemiological diagnosis of CLA.

Publication year: 2007

Types of publication: Journal article

Unit: Embrapa Goats & Sheep

Keywords: Bacterial diseases, Base eequence, CLA, Caprino, Caseous lymphadenitis, Corynebacterium Infections, Corynebacterium Pseudotuberculosis, Linfadenite Caseosa, Lymph nodes, Molecular sequence data, Ovino, PCR, Polymerase chain reaction, RNA bacterial, Sheep diseases