Specific detection and differentiation of Ochrobactrum anthropi, Ochrobactrum intermedium and Brucella spp. by a multi-primer PCR that targets the recA gene.

Ochrobactrum anthropi, Ochrobactrum intermedium and Brucella spp. are phenotypically and genetically closely related pathogens that may cause disease with similar clinical presentation. Consequently, difficulties in their identification and differentiation have been reported. In this study, a sensitive recA gene-based multi-primer single-target PCR (MP-ST-PCR) was developed that allowed the specific detection and differentiation of these clinically relevant pathogens. The specificity of the assay was evaluated using a representative panel of 50 O. anthropi and 16 O. intermedium strains and the type strains of all Brucella spp. Detection limits for purified DNA from O. anthropi, O. intermedium and Brucella melitensis were 100, 10 and 100 fg, respectively. Brucella DNA was also successfully detected in various clinical specimens from a human patient with culture-proven brucellosis and from a Brucella-infected sheep and its aborted fetuses. The sensitivity of the MP-ST-PCR was comparable to that of an evaluated in-house Brucella real-time PCR assay. The developed assay closes a diagnostic gap and provides a simple but robust tool for the sensitive detection and correct identification of O. anthropi, O. intermedium and Brucella spp.