Abstract:
Bartonella bovis is commonly detected in cattle. One B. bovis strain was recently isolated from a cow with
endocarditis in the USA, suggesting its role as an animal pathogen. In the present study, we investigated bartonella
infections in 893 cattle from five countries (Kenya, Thailand, Japan, Georgia, and Guatemala) and 103 water
buffaloes from Thailand to compare the prevalence of the infection among different regions and different bovid hosts.
We developed a multi-locus sequence typing (MLST) scheme based on nine loci (16S rRNA, gltA, ftsZ, groEL, nuoG,
ribC, rpoB, ssrA, and ITS) to compare genetic divergence of B. bovis strains, including 26 representatives from the
present study and two previously described reference strains (one from French cows and another from a cow with
endocarditis in the USA). Bartonella bacteria were cultured in 6.8% (7/103) of water buffaloes from Thailand; all were
B. bovis. The prevalence of bartonella infections in cattle varied tremendously across the investigated regions. In
Japan, Kenya, and the Mestia district of Georgia, cattle were free from the infection; in Thailand, Guatemala, and the
Dusheti and Marneuli districts of Georgia, cattle were infected with prevalences of 10–90%. The Bartonella isolates
from cattle belonged to three species: B. bovis (n=165), B. chomelii (n=9), and B. schoenbuchensis (n=1), with the
latter two species found in Georgia only. MLST analysis suggested genetic variations among the 28 analyzed B.
bovis strains, which fall into 3 lineages (I, II, and III). Lineages I and II were found in cattle while lineage III was
restricted to water buffaloes. The majority of strains (17/28), together with the strain causing endocarditis in a cow in
the USA, belonged to lineage I. Further investigations are needed to determine whether B. bovis causes disease in
bovids.
