The severe Ebola virus disease epidemic occurring in West Africa stems from a single zoonotic transmission event to a 2-year-old boy in Meliandou, Guinea. We investigated the zoonotic origins of the epidemic using wildlife surveys, interviews, and molecular analyses of bat and environmental samples. We found no evidence for a concurrent outbreak in larger wildlife. Exposure to fruit bats is common in the region, but the index case may have been infected by playing in a hollow tree housing a colony of insectivorous free-tailed bats (Mops condylurus). Bats in this family have previously been discussed as potential sources for Ebola virus outbreaks, and experimental data have shown that this species can survive experimental infection. These analyses expand the range of possible Ebola virus sources to include insectivorous bats and reiterate the importance of broader sampling efforts for understanding Ebola virus ecology.
As the only volant mammals, bats are captivating for their high taxonomic diversity, for their vital roles in ecosystems-particularly as pollinators and insectivores-and, more recently, for their important roles in the maintenance and transmission of zoonotic viral diseases. Genome sequences have identified evidence for a striking expansion of and positive selection in gene families associated with immunity. Bats have also been known to be hosts of malaria parasites for over a century, and as hosts, they possess perhaps the most phylogenetically diverse set of hemosporidian genera and species. To provide a molecular framework for the study of these parasites, we surveyed bats in three remote areas of the Upper Guinean forest ecosystem. We detected four distinct genera of hemosporidian parasites: Plasmodium, Polychromophilus, Nycteria, and Hepatocystis. Intriguingly, the two species of Plasmodium in bats fall within the clade of rodent malaria parasites, indicative of multiple host switches across mammalian orders. We show that Nycteria species form a very distinct phylogenetic group and that Hepatocystis parasites display an unusually high diversity and prevalence in epauletted fruit bats. The diversity and high prevalence of novel lineages of chiropteran hemosporidians underscore the exceptional position of bats among all other mammalian hosts of hemosporidian parasites and support hypotheses of pathogen tolerance consistent with the exceptional immunology of bats.Haemosporida | Chiroptera | vector-borne disease | molecular phylogeny | host-pathogen coevolution
Hunting and loss of natural habitats increasingly threaten tropical biodiversity and ecosystems, particularly in Southeast Asia. Flying foxes often persist in anthropogenic areas where other wildlife has vanished, and where they play a significant ecological role in vegetation regeneration in disturbed habitats. Detailed knowledge on the foraging behavior of flying foxes is crucial for understanding how they survive in degraded habitats and for the management of human-wildlife conflicts. Thailand still harbors large colonies (several thousand individuals) of Lyle's flying fox (Pteropus lylei), a species ranked as Vulnerable on the International Union for Conservation of Nature (IUCN) Red List, at temples situated in agricultural landscapes. We used high-resolution global positioning system (GPS) loggers to study the movement and foraging behavior of this species at 2 temples in central Thailand during 2 seasons. We analyzed GPS and acceleration data of 19 tagged individuals, and assessed habitat use and diet. Foraging individuals commuted between day roosts and foraging areas each night, followed by small-scale movements in foraging areas, and showed high site fidelity during the study period. Maximum linear distances between day roosts and foraging areas varied greatly between individuals (2.2-23.6 km) but were similar between seasons. Tracked bats mostly foraged in farmland, plantations, and gardens, yet our data indicate that small mangrove remnants constitute important habitat components for Lyle's flying fox. We recorded a highly diverse diet of 34 food plant species, comprised of exotic crops and native plants as available. Our results suggest that conservation and landscape managers should preserve remaining native trees and natural vegetation in the study area as resources for Lyle's flying fox, at the same time reducing potential for conflicts between bats and humans on crops. They can further be used for public information campaigns integrating the potential of Lyle's flying fox as dispersers of useful plants and the human health risks through zoonotic diseases associated with hunting and consumption of this species.
Parasitic protozoan parasites have evolved many co-evolutionary paths towards stable transmission to their host population. Plasmodium spp., the causative agents of malaria, and related haemosporidian parasites are dipteran-borne eukaryotic pathogens that actively invade and use vertebrate erythrocytes for gametogenesis and asexual development, often resulting in substantial morbidity and mortality of the infected hosts. Here, we present results of a survey of insectivorous bats from tropical Africa, including new isolates of species of the haemosporidian genus Nycteria. A hallmark of these parasites is their capacity to infect bat species of distinct families of the two evolutionary distant chiropteran suborders. We did detect Nycteria parasites in both rhinolophid and nycterid bat hosts in geographically separate areas of Sub-Saharan Africa, however our molecular phylogenetic analyses support the separation of the parasites into two distinct clades corresponding to their host genera, suggestive of ancient co-divergence and low levels of host switching. For one clade of these parasites, cytochrome b genes could not be amplified and cytochrome oxidase I sequences showed unusually high rates of evolution, suggesting that the mitochondrial genome of these parasites may have either been lost or substantially altered. This haemosporidian parasite-mammalian host system also highlights that sequential population expansion in the liver and gametocyte formation is a successful alternative to intermediate erythrocytic replication cycles.
Bats are suspected to be a reservoir of several bacterial and viral pathogens relevant to animal and human health, but studies on Escherichia coli in these animals are sparse. We investigated the presence of E. coli in tissue samples (liver, lung and intestines) collected from 50 fruit bats of five different species (Eidolon helvum, Epomops franqueti, Hypsignathus monstrosus, Myonycteris torquata, Rousettus aegyptiacus) of two different areas in the Republic of Congo between 2009 and 2010. To assess E. coli pathotypes and phylogenetic relationships, we determined the presence of 59 virulence associated genes and multilocus sequence types (STs). Isolates were further tested for their susceptibility to several antimicrobial substances by agar disk diffusion test and for the presence of an Extended-Spectrum Beta-Lactamase phenotype. E. coli was detected in 60% of the bats analysed. The diversity of E. coli strains was very high, with 37 different STs within 40 isolates. Occasionally, we detected sequence types (e.g. ST69, ST127, and ST131) and pathotypes (e.g. ExPEC, EPEC and atypical EPEC), which are known pathogens in human and/or animal infections. Although the majority of strains were assigned to phylogenetic group B2 (46.2%), which is linked with the ExPEC pathovar, occurrence of virulence-associated genes in these strains were unexpectedly low. Due to this, and as only few of the E. coli isolates showed intermediate resistance to certain antimicrobial substances, we assume a rather naïve E. coli population, lacking contact to humans or domestic animals. Future studies featuring in depth comparative whole genome sequence analyses will provide insights into the microevolution of this interesting strain collection.
The tree. Trees in the genus Carapa (Meliaceae) grow in all African tropical forests along the Equator, from the Albertine Rift region to Southern Senegal and Mali. In Africa, as well as in South America, carapa trees are the source of valuable timber and non-timber forest products (NTFP). Fruit and seeds. A typical carapa fruit consists of a capsule with four to five valves, each enclosing two to five seeds, i.e., a total of eight to twenty seeds per fruit. Oil extraction. Village inhabitants strive to collect seeds that have fallen to the ground before they get infested or germinate, which is detrimental to oil quality. The oil is extracted after the seeds have been boiled. Carapa oil has a broad application range and is used more frequently than the extracts from leaves, bark or root. Market. The carapa oil trade in Africa has a primarily local orientation, and the commercialization of the oil is rudimentary. However, the use of carapa oil as a natural repellent in the cultivation of organic cotton is expected to create an increased demand for oil production. Discussion. With regard to the high economic potential of carapa oil, its commercialization needs to provide the producers with equitable revenue for the efforts to render it profitable. Measures to protect carapa populations and their habitats are needed to allow for the long-term production of carapa oil. The plantation of trees appears to be a sustainable approach for the conservation of natural carapa tree stands. Mali / Senegal / WestAfrica / Carapa / non-wood forest products / plant oils / traditional uses / cotton / botanical insecticides L'huile de carapa (Carapa spp. Meliaceae) en Afrique de l'Ouest : utilisations et implications dans la conservation des peuplements naturels.
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