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

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

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

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.</jats:p

Data from: Two novel genera and one new species of treefrog (Anura: Rhacophoridae) highlight cryptic diversity in the Western Ghats of India

Amphibian diversity in the Western Ghats-Sri Lanka biodiversity hotspot is extremely high, especially for such a geo-graphically restricted area. Frogs in particular dominate these assemblages, and the family Rhacophoridae is chief among these, with hundreds of endemic species. These taxa continue to be described at a rapid pace, and several groups have recently been found to represent unique evolutionary clades at the genus level. Here, we report DNA sequences, larval and breeding data for two species of rhacophorid treefrog (Polypedates bijui and a new, hitherto undescribed species). Re-markably, they represent unique, independent clades which form successive sister groups to the Pseudophilautus (Sri Lan-ka) + Raorchestes (India, China & Indochina) clades. We place these species into two new genera (Beddomixalus gen. nov. and Mercurana gen. nov.). Both of these genera exhibit a distinct reproductive mode among Rhacophoridae of pen-insular India and Sri Lanka, with explosive breeding and semiterrestrial, unprotected, non-pigmented eggs oviposited in seasonal swamp pools, which hatch into exotrophic, free-living aquatic tadpoles. Relationships and representation of re-productive modes in sister taxa within the larger clade into which these novel genera are placed, is also discussed. These results suggest that more undescribed taxa may remain to be discovered in South Asia, and the crucial importance of con-serving remaining viable habitats

Host–Pathogen–Vector Continuum in a Changing Landscape: Potential Transmission Pathways for Bartonella in a Small Mammal Community

ABSTRACT Bacterial infections account for a large proportion of zoonoses. Our current understanding of zoonotic spillover, however, is largely based on studies from viral systems. Small mammals such as rodents and their ectoparasites present a unique system for studying several bacterial pathogens and mapping their spillover pathways. Using Bartonella spp. (a Gram‐negative bacteria) as a model system within a rainforest human‐use landscape, we investigated (1) ecological correlates of Bartonella prevalence in small mammal hosts and (2) evolutionary relationships between Bartonella spp. and various hosts and ectoparasites to gain insight into pathogen movement pathways within ecological communities. We detected Bartonella in five out of eight small mammal species and in 86 (40.56%) out of 212 individuals, but prevalence varied widely among species (0%–75.8%). Seven of the ten ectoparasite species found on these small mammals were positive for Bartonella. Interestingly, while Bartonella genotypes (15) in small mammals were host‐specific, ectoparasites had nonspecific associations, suggesting the possibility for vector‐mediated cross‐species transmission. We also found that Bartonella prevalence in hosts was positively correlated with their aggregated ectoparasite loads, further emphasizing the crucial role that ectoparasites may play in these transmission pathways. Our cophylogenetic analysis and ancestral trait (host) reconstruction revealed incongruence between small mammal and Bartonella phylogenies, indicating historic host shifts and validating the potential for contemporary spillover events. We found that small mammal hosts in this fragmented landscape often move across habitat boundaries, creating a transmission pathway (via shared ectoparasites) to novel hosts, which may include synanthropic species like Rattus rattus. Our results highlight the necessity to disentangle the complex relationship among hosts, ectoparasites, and bacterial pathogens to understand the implications of undetected spillover events

Supplementary file 1

Breeding chorus of Beddomixalus biju

Whole genome sequencing of rabies virus from archived human and canine brain tissues from southern India using Nanopore technology

Rabies, a fatal zoonotic viral encephalitis kills tens of thousands of people each year in India, representing one third of the estimated global rabies burden. A detailed understanding of the molecular epidemiology of the Rabies lyssavirus (RABV) in India is limited due to the low availability of sequences from the country. In this study we examined the feasibility of direct sequencing of clinical samples (archived human and canine brain tissues, 10 each), for detection and recovery of whole genome sequences of RABV, on the MinION – single molecule nanopore sequencing device. Using an amplicon-based approach, complete RABV genomes were recovered from all the 20 samples, archived from 2003 to 2019, from 4 southern states of India. Phylogenetic analysis revealed that all 20 sequences from this study belonged to the Arctic-like (AL) 1a lineage. Divergence estimation of sequences revealed that all the circulating RABV strains within India are diverged in last 60 years from the previous ancestor. The genetic relatedness and close clustering of the sequences in the study suggests the continued propagation of AL1a in the region, across state boundaries. Genomic surveillance can provide unique insights into rabies spread and persistence that can direct control efforts in India.</jats:p

Supplementary file 2

Advertisement call of Mercurana myristicapalustri

Health Heatmap of India: An Open Data Platform

AbstractHealth Heatmap of India is an open data platform built for bringing together data from diverse sources and facilitating visualization, analysis, and insight building from such data. In this paper, we describe the context and need for such an open data platform and describe the technical aspects of building it. The beta site of the portal is available at http://healthheatmapindia.org</jats:p