TDK conference 2008

Corynebacterium pseudotuberculosis is the etiologic agent of caseous lymphadenitis (CLA) in ruminants and ulcerative lymphangitis in horses. CLA is a chronic contagious disease, which can be found all over the world. In Hungary it was noticed in many goat populations in the 1980’s. Today is a rarely diagnosed infectious disease, but it can be seen regularly in sheep and goat flocks in Hungary.

The aim of our study was the comparison and evaluation of different diagnostic methods including the API Coryne test (bioMerieux Inc., France), Biolog system (BIOLOG Inc., USA) (metabolic fingerprint) and the sequence analysis of 16S ribosomal RNA gene for the identification of Hungarian C. pseudotuberculosis isolates. All together 20 C. pseudotuberculosis isolates, 17 belonged to the strain collection of the Department of Microbiology and Infectious Diseases (Szent István University, Faculty of Veterinary Science, Budapest) and 3 type-strains, received from DSMZ (German Collection of Microorganisms and Cell Cultures Ltd., Germany), were involved in our study. These strains were isolated from different animal species (sheep, goat, swine and horse).

As a first step extraction of DNA, amplification and sequence analysis of a partial (450 bp) 16S ribosomal RNA gene were carried out. On the basis of sequence analysis out of the 20 isolates 17 were identified as C. pseudotuberculosis. The results of the identification by sequence analysis corresponded to the results of the API Coryne system in 15 cases, but only in 3 cases to the Biolog system. Identification of the Hungarian C. pseudotuberculosis isolates with the API Coryne test proved to be more effective at the present than with the Biolog system. On the basis of our results the database of Biolog system should be corrected in the case of C. pseudotuberculosis and several related species (C. diphteriae, C. ulcerans).