High prevalence and diversity of Bartonella in small mammals from the biodiverse Western Ghats

Abstract

Bartonella species are recognized globally as emerging zoonotic pathogens. Small mammals such as rodents and shrews are implicated as major natural reservoirs for these microbial agents. Nevertheless, in several tropical countries, like India, the diversity of Bartonella in small mammals remain unexplored and limited information exists on the natural transmission cycles (reservoirs and vectors) of these bacteria. Using a multi-locus sequencing approach, we investigated the prevalence, haplotype diversity, and phylogenetic affinities of Bartonella in small mammals and their associated mites in a mixed-use landscape in the biodiverse Western Ghats in southern India. We sampled 141 individual small mammals belonging to eight species. Bartonella was detected in five of the eight species, including three previously unknown hosts. We observed high interspecies variability of Bartonella prevalence in the host community. However, the overall prevalence (52.5%) and haplotype diversity (0.9) was high for the individuals tested. Of the seven lineages of Bartonella identified in our samples, five lineages were phylogenetically related to putative zoonotic species–B. tribocorum, B. queenslandensis, and B. elizabethae. Haplotypes identified from mites were identical to those identified from their host species. This indicates that these Bartonella species may be zoonotic, but further work is necessary to confirm whether these are pathogenic and pose a threat to humans. Taken together, these results emphasize the presence of hitherto unexplored diversity of Bartonella in wild and synanthropic small mammals in mixed-use landscapes. The study also highlights the necessity to assess the risk of spillover to humans and other incidental hosts.

Serological and Molecular Detection of Bartonella henselae in Cats and Humans From Egypt: Current Status and Zoonotic Implications

“…However, the influence of flea infestation, which is more likely in warm and humid areas than in cold areas, should also be considered ( 52 , 53 ). Furthermore, other factors, including sample size, environmental conditions, hygienic practices and socioeconomic level, type of diagnostic method (either serological or molecular), type of PCR and primers used, and the studied population (stray vs. household cats), might influence the differences in the reported rates of infection by B. henselae among cats in different countries ( 35 , 54 – 58 ). It is evident that the molecular detection of B. henselae is more reliable and sensitive than culture techniques to identify the microorganism, as documented in several previous studies ( 47 , 59 , 60 ).…”

Host-pathogen-vector continuum in a changing landscape: Drivers ofBartonellaprevalence and evidence of historic spillover in a multi-host community

“…fernandoni as M. musculus and M. cf. famulus and M. cf terricolor as M. booduga [43]. Phylogenetic analysis and genetic distances suggest that these are distinct lineages related to M. fernandoni , M. famulus , and M. terricolor , respectively.…”

“…To detect Bartonella in small mammals, DNA was extracted using QIAamp DNA Mini Kit (Qiagen) from the dried blood spots (DBS) collected in 2018 (Kadamane) and 2021 (Kudremukh), and screened for Bartonella specific rpoB gene (825 bp) using conventional PCR [42]. Bartonella prevalence in the Kadamane samples was reported previously [43]. To detect Bartonella in ectoparasites, ectoparasite were pooled, mechanically homogenised, and DNA was extracted using DNeasy Blood & Tissue Kit (Qiagen).…”

“…Within Kadamane, forests and rested plantations also had an analogous community, dominated by R. satarae. [43]. Due to the similarity between these two habitats, we treated them as functionally equivalent, enabling us to better estimate small mammal densities and comprehensively explore habitat associations and Bartonella prevalence.…”

Molecular Survey of Bartonella Species in Stray Cats and Dogs, Humans, and Questing Ticks from Portugal

“…Multilocus sequence typing (MLST) studies have been conducted on Bartonella spp. contributing to clarifying phylogenetic relationships, host specificity, diversity and the discovery of novel species [ 21 , 27 , 28 , 29 ].…”