Bartonella infections were investigated in seven species of bats from four regions of the Republic of Georgia. Of the 236 bats that were captured, 212 (90%) specimens were tested for Bartonella infection. Colonies identified as Bartonella were isolated from 105 (49.5%) of 212 bats Phylogenetic analysis based on sequence variation of the gltA gene differentiated 22 unique Bartonella genogroups. Genetic distances between these diverse genogroups were at the level of those observed between different Bartonella species described previously. Twenty-one reference strains from 19 representative genogroups were characterized using four additional genetic markers. Host specificity to bat genera or families was reported for several Bartonella genogroups. Some Bartonella genotypes found in bats clustered with those identified in dogs from Thailand and humans from Poland.

The recent discovery of genetically distinct hantaviruses in multiple species of shrews and moles prompted a further exploration of their host diversification by analyzing frozen, ethanol-fixed and RNAlater®-preserved archival tissues and fecal samples from 533 bats (representing seven families, 28 genera and 53 species in the order Chiroptera), captured in Asia, Africa and the Americas in 1981–2012, using RT-PCR. Hantavirus RNA was detected in Pomona roundleaf bats (Hipposideros pomona) (family Hipposideridae), captured in Vietnam in 1997 and 1999, and in banana pipistrelles (Neoromicia nanus) (family Vespertilionidae), captured in Côte d’Ivoire in 2011. Phylogenetic analysis, based on the full-length S- and partial M- and L-segment sequences using maximum likelihood and Bayesian methods, demonstrated that the newfound hantaviruses formed highly divergent lineages, comprising other recently recognized bat-borne hantaviruses in Sierra Leone and China. The detection of bat-associated hantaviruses opens a new era in hantavirology and provides insights into their evolutionary origins.

Bats are important reservoirs for many zoonotic pathogens. However, no surveys of bacterial pathogens in bats have been performed in the Caucasus region. To understand the occurrence and distribution of bacterial infections in these mammals, 218 bats belonging to eight species collected from four regions of Georgia were examined for Bartonella, Brucella, Leptospira, and Yersinia using molecular approaches. Bartonella DNA was detected in 77 (35%) bats from all eight species and was distributed in all four regions. The prevalence ranged 6–50% per bat species. The Bartonella DNA represented 25 unique genetic variants that clustered into 21 lineages. Brucella DNA was detected in two Miniopterus schreibersii bats and in two Myotis blythii bats, all of which were from Imereti (west-central region). Leptospira DNA was detected in 25 (13%) bats that included four M. schreibersii bats and 21 M. blythii bats collected from two regions. The Leptospira sequences represented five genetic variants with one of them being closely related to the zoonotic pathogen L. interrogans (98.6% genetic identity). No Yersinia DNA was detected in the bats. Mixed infections were observed in several cases. One M. blythii bat and one M. schreibersii bat were co-infected with Bartonella, Brucella, and Leptospira; one M. blythii bat and one M. schreibersii bat were co-infected with Bartonella and Brucella; 15 M. blythii bats and three M. schreibersii bats were co-infected with Bartonella and Leptospira. Our results suggest that bats in Georgia are exposed to multiple bacterial infections. Further studies are needed to evaluate pathogenicity of these agents to bats and their zoonotic potential.