Introduction: The bacterium Bartonella is transmitted by fleas, ticks, and animals, and can cause severe disease in mammals. This bacteria has been identified in bats all over the world; recently, a human case in the USA was... [ view full abstract ]
Introduction: The bacterium Bartonella is transmitted by fleas, ticks, and animals, and can cause severe disease in mammals. This bacteria has been identified in bats all over the world; recently, a human case in the USA was associated with a novel Bartonella species, which was traced back to bats in Finland. Little is known about the presence of Bartonella species in bats, and no current studies have been conducted in Georgia. In this study, Bartonella species were isolated and investigated in seven different species of bats from four regions in Georgia.
In total, 212 bats where collected and Bartonella spp. were isolated from blood samples: Kvemo kartli (n=46), Davit Gareja (n=46), Imereti (n=66), and Samegrelo (n=49). We also used five genetic loci (ftsZ, gltA, nuoG, rpoB, and groEL) that have been used for Bartonella spp. characterization. Sequencing was performed with an ABI 3130 Genetic Analyzer, and reads were assembled into consensus sequences with the SeqMan Pro program in Lasergene v.11. Alignment was performed with MAFFT v7.187 using the local, accurate L-INS-i method. No codon partitioning was used because gltA sequences represents only a 367-base pair fragment of the entire gene. For Bayesian phylogeny analysis of our sequences, we used BEAST v1.8. Positive sequences were aligned with Bartonella reference sequences (from GenBank), which included sequences obtained from various bats that were included in previous studies.
From our samples, 21 isolates were identified based on variation of the gltA gene. The Bayesian analysis indicated that most gltA sequences from Georgian bats cluster closely with each other as distinct genogroups from known Bartonella species. The phylogeny based on concatenated sequences from five genetic loci confirmed that most Bartonella genogroups from Georgian bats formed well-supported clades (posterior probability > 90%) with other Bartonella genogroups identified in bats. Host specificity to bat genera or families were reported for several Bartonella genogroups.
Some Bartonella genotypes found in Georgian bats, clustered with those identified in dogs from Thailand and humans from Poland. Our study suggests that Bartonella surveillance should include several mammal species as reservoirs, in order to better understand the risks of disease transmission and the true genotypes circulating in Georgia.
