Identification of novel Bartonella spp. in bats and evidence of Asian gray shrew as a new potential reservoir of Bartonella

Abstract

Many studies indicated that small mammals are important reservoirs for Bartonella species. Using molecular methods, several studies have documented that bats could harbor Bartonella. This study was conducted to investigate the relationship of Bartonella spp. identified in bats and small mammals living in the same ecological environment. During May 2009 and March 2010, a total of 102 blood specimens were collected. By whole blood culture and molecular identification, a total of 6 bats, 1 rodent and 9 shrews were shown to be infected by Bartonella species. After sequencing and phylogenetic analyses of the sequences of gltA, ftsZ, rpoB and ribC genes, these specific isolates from bats were not similar to the known Bartonella species (the similarity values were less than 91.2%, 90.5%, 88.8%, and 82.2%, respectively); these isolates formed an independent clade away from other known Bartonella type strains. The Bartonella spp. isolated from small mammals, which were closely related to Bartonella tribocorum, Bartonella elizabethae, Bartonella grahamii, Bartonella rattimassiliensis and Bartonella queenslandensis, were similar to the findings in previous studies worldwide. Therefore, the results implied that the species of Bartonella strains isolated from small mammals were different from those identified in bats. Our results strongly suggested that the bat isolate could be a new Bartonella species. This study is also the first one to isolate Bartonella organisms from Asian gray shrews, Crocidura attenuata tanakae.

Fig. 1

Phylogenetic analysis of different Bartonella species on the basis of partial DNA sequences of the gltA gene. The phylogenetic relationship was constructed by using the maximum-parsimony method of the PHYLIP version 3.6 program, and bootstrap analysis was performed with 1000 trials of bootstrap data (bootstrap values not shown if lower than 70%).

Fig. 2

Phylogenetic analysis of different Bartonella species based on the sequences of a merged set of concatenated sequences of five genes (16S rRNA, ftsZ, gltA, ribC and rpoB genes). The phylogenetic relationship was constructed by using the maximum-parsimony method of the PHYLIP version 3.6 program, and bootstrap analysis was performed with 1000 trials of bootstrap data (bootstrap values not shown if lower than 70%).