Development of a Novel Genus-specific Real-time PCR Assay for Detection and Differentiation of Bartonella Species and Genotypes.

Diaz MH, Bai Y, Malania L, Winchell JM, Kosoy MY.

Source

Respiratory Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30333.

Abstract

The genus Bartonella includes numerous species with varied host association, including several that infect humans. Development of a molecular diagnostic method capable of detecting the diverse repertoire of Bartonella species while maintaining genus specificity has been a challenge. We developed a novel real-time PCR assay targeting a 301 bp region of the ssrA gene of Bartonella and demonstrated specific amplification in over 30 Bartonella species, subspecies, and strains. Subsequent analysis of ssrA sequences was sufficient to discriminate Bartonella species and provided phylogenetic data consistent with that of gltA, a commonly used gene for differentiating Bartonella genotypes. Using this assay we identified Bartonella DNA in 29% and 47% of blood specimens from elk in Wyoming and cattle in the Republic of Georgia, respectively. Sequence analysis of a subset of genotypes from elk specimens revealed a cluster most closely related to B. capreoli, and genotypes from cattle were identified as B. bovis, both Bartonella species commonly found in wild and domestic ruminants. Considering the widespread geographic distribution and infectivity potential to a variety of hosts, this assay may be an effective diagnostic method for identification of Bartonella infections in humans and have utility in Bartonella surveillance studies.