Considering the difficulty to differentiate the species of Rhodococcus by biochemical tests, a Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) has been developed to distinguish the species of the genus Rhodococcus. R. equi, R. rhodnii and other bacterial samples were cultured on Blood agar and BHI at 26 and 37°C. The obtained DNA was amplified with the primers described by Hypsa and Dale. Products of amplification were submitted to digestion with multiple restriction enzymes and the restriction patterns were confirmed by using in silico analysis. The expected amplification fragment of 1300 pb was obtained in all tested samples. R. equi was distinguished from R. rhodnii by using endonucleases such as PstI and HindIII, and from other bacteria with endonucleases PstI, HindIII, SstI, BamHI and EcoRI. The obtained restriction patterns were confirmed by using in silico analysis. This PCR-RFLP establishes an alternative for the differentiation among species of the genus Rhodococcus such as R. equi and R. rhodnii.
