Differentiation of Brucella species by random amplified polymorphic DNA analysis

Random amplification of polymorphic DNA (RAPD) was used for discrimination between 46 Brucella strains and 14 representatives of the alpha-2 and alpha-1 subgroups of Proteobacteria. To evaluate a relatively quick and exact method for Brucella identification, the authors specified the most suitable conditions for RAPD amplification of Brucella DNA with two 10-mer primers, containing lower and higher percentages of G and C. The software package PHYLIP 3.1 was used for cluster analysis of the RAPD fingerprints. The optimization of RAPD conditions resulted in PCR mixes suitable for reliable typing of Brucellae. The distance-based methods (Fitch-Margoliash, UPGMA and Neighbour-joining) gave clear discrimination between Brucella species. The constructed dendrograms put Br. canis and Br. suis bv. 1 in the same cluster and differentiated Brucella strains according to their host preferences. RAPD can be useful method to distinguish related bacterial species, and under strictly established conditions the reaction appears to be a simple, quick and sensitive technique for the epidemiological investigation of brucellosis.