Monitoring of Bartonella spp. in Iberian bats from Spain

Chiroptera play a key role in the environment by providing pivotal ecosystem services. However, bats can be hosts of several zoonotic pathogens, including bacteria belonging to the Bartonella genus. This molecular study aimed to fill the notable lack of information concerning Bartonella spp. in bats from the Iberian Peninsula. We investigated the occurrence, risk factors and molecular characterization of this pathogen in 240 live bats sampled in northern, central, and southern areas of Spain during 2020-2021. Blood DNA samples from 22 bat species of Miniopteridae, Vespertilionidae and Rhinolophidae were analyzed using PCR assays and Sanger sequencing. The results showed a Bartonella spp. prevalence of 17.1 % (41/240), with at least one positive individual in 13 bat species of six genera. Miniopterus schreibersii showed the highest prevalence (40.5 %; 95 % CI: 24.7-56.4), and to the authors' knowledge, Bartonella spp. is reported for the first time in Barbastella barbastellus, Nyctalus lasiopterus and Nyctalus leisleri. Infestation with ectoparasites (ticks, bat flies and/or mites) and bat family (Miniopteridae) were significantly associated with Bartonella prevalence. Sequencing revealed genetic similarities with Bartonella sp. sequences reported from bats and bat ectoparasites of various regions (e.g. Finland, France, South Korea, China, Georgia, Czech Republic or United Kingdom). Moreover, potential new species, distant from all other published sequences, were identified. In conclusion, Bartonella spp. infection is widely distributed within bat populations across peninsular Spain, and further work should be conducted to better understand the Bartonella species diversity circulating in Iberian bats.