Multilocus sequence analysis of Bartonella strains isolated from small rodents

In the ecosystem rodents play an important role as they are the main carriers of various infectious diseases causative agents. Rodents are considered the reservoir hosts for several Bartonella spp. According to the latest data, more than 20 Bartonella spp. have been detected in small rodents and at least 6 of them are associated with human diseases. The aim of our study was to investigate the presence and genetic diversity of Bartonella strains in small rodents using multilocus sequence analysis. We analysed 324 spleen samples, obtained from seven small rodent species (A. flavicollis, A. agrarius, M. minutus, M. glareolus, M. oeconomus, M. agrestis, M. musculus), trapped in Lithuania during 2015–2016. The presence of Bartonella DNA was detected by using real-time PCR targeting the ssrA gene. Characterization of genetic diversity of Bartonella strains were based on sequences analysis of two housekeeping genes (groEL, rpoB) and the 16S-23S rRNA intergenic spacer region (ITS). Bartonella pathogens were detected in 136 (42 %) individuals. Phylogenetic analysis of Bartonella isolates demonstrated the presence of six genetically different clades associated with human pathogenic B. grahamii, B.rochalimae and B. tribocorum species, and other species B. taylorii, B. coopersplainsensis and B. doshiae which pathogenicity to humans is still unknown. Bartonella strains belonged to B. grahamii and B. taylorii clades were heterogenic. Phylogenetic analysis based on each of the targets demonstrated high variability of B. taylorii and B. grahamii strains between different and either same rodent species. The frequent distribution and high genetic diversity of Bartonella species in rodents suggest that they may contribute to unidentified clinical infections, that shows the importance of further investigationsBiologijos katedraGamtos mokslų fakultetasGamtos tyrimų centrasVilniaus universitetasVytauto Didžiojo universiteta