PCR detection of Bartonella bovis and Bartonella henselae in the blood of beef cattle

Abstract

Although an organism primarily associated with non-clinical bacteremia in domestic cattle and wild ruminants, Bartonella bovis was recently defined as a cause of bovine endocarditis. The purpose of this study was to develop a B. bovis species-specific PCR assay that could be used to confirm the molecular prevalence of Bartonella spp. infection. Blood samples from 142 cattle were tested by conventional PCR targeting the Bartonella 16S-23S intergenic spacer (ITS) region. Overall, Bartonella DNA was detected in 82.4% (117/142) of the cattle using either Bartonella genus primers or B. bovis species-specific primers. Based upon size, 115 of the 117 Bartonella genus ITS PCR amplicons were consistent with B. bovis infection, which was confirmed by PCR using B. bovis species-specific primers and by sequencing three randomly selected, appropriately sized Bartonella genus PCR amplicons. By DNA sequencing, Bartonella henselae was confirmed as the two remaining amplicons, showing sequence similarity to B. henselae URBHLIE 9 (AF312496) and B. henselae Houston 1 (NC_005956), respectively. Following pre-enrichment blood culture of 12 samples in Bartonella alpha Proteobacteria growth medium (BAPGM) B. henselae infection was found in another three cows. Four of the five cows infected with B. henselae were co-infected with B. bovis. To our knowledge this study describes the first detection of B. henselae in any large ruminant species in the world and supports the need for further investigation of prevalence and pathogenic potential of B. henselae and B. bovis in cattle.