Bat flies (Diptera: Nycteribiidae and Streblidae) infesting cave-dwelling bats in Gabon: Diversity, dynamics and potential role in Polychromophilus melanipherus transmission

Background Evidence of haemosporidian infections in bats and bat flies has motivated a growing interest in characterizing their transmission cycles. In Gabon (Central Africa), many caves house massive colonies of bats that are known hosts of Polychromophilus Dionisi parasites, presumably transmitted by blood-sucking bat flies. However, the role of bat flies in bat malaria transmission remains under-documented. Methods An entomological survey was carried out in four caves in Gabon to investigate bat fly diversity, infestation rates and host preferences and to determine their role in Polychromophilus parasite transmission. Bat flies were sampled for 2–4 consecutive nights each month from February to April 2011 (Faucon and Zadie caves) and from May 2012 to April 2013 (Kessipoughou and Djibilong caves). Bat flies isolated from the fur of each captured bat were morphologically identified and screened for infection by haemosporidian parasites using primers targeting the mitochondrial cytochrome b gene. Results Among the 1,154 bats captured and identified as Miniopterus inflatus Thomas (n = 354), Hipposideros caffer Sundevall complex (n = 285), Hipposideros gigas Wagner (n = 317), Rousettus aegyptiacus Geoffroy (n = 157, and Coleura afra Peters (n = 41), 439 (38.0 %) were infested by bat flies. The 1,063 bat flies recovered from bats belonged to five taxa: Nycteribia schmidlii scotti Falcoz, Eucampsipoda africana Theodor, Penicillidia fulvida Bigot, Brachytarsina allaudi Falcoz and Raymondia huberi Frauenfeld group. The mean infestation rate varied significantly according to the bat species (ANOVA, F (4,75) = 13.15, P < 0.001) and a strong association effect between bat fly species and host bat species was observed. Polychromophilus melanipherus Dionisi was mainly detected in N. s. scotti and P. fulvida and less frequently in E. africana, R. huberi group and B. allaudi bat flies. These results suggest that N. s. scotti and P. fulvida could potentially be involved in P. melanipherus transmission among cave-dwelling bats. Sequence analysis revealed eight haplotypes of P. melanipherus. Conclusions This work represents the first documented record of the cave-dwelling bat fly fauna in Gabon and significantly contributes to our understanding of bat fly host-feeding behavior and their respective roles in Polychromophilus transmission. (Résumé d'auteur

Patterns of foraging activity and fidelity in a Southeast Asian flying fox

Background: Improved understanding of the foraging ecology of bats in the face of ongoing habitat loss and modification worldwide is essential to their conservation and maintaining the substantial ecosystem services they provide. It is also fundamental to assessing potential transmission risks of zoonotic pathogens in human-wildlife interfaces. We evaluated the influence of environmental and behavioral variables on the foraging patterns of Pteropus lylei (a reservoir of Nipah virus) in a heterogeneous landscape in Cambodia. Methods: We employed an approach based on animal-movement modeling, which comprised a path-segmentation method (hidden Markov model) to identify individual foraging-behavior sequences in GPS data generated by eight P. lylei. We characterized foraging localities, foraging activity, and probability of returning to a given foraging locality over consecutive nights. Generalized linear mixed models were also applied to assess the influence of several variables including proxies for energetic costs and quality of foraging areas. Results: Bats performed few foraging bouts (area-restricted searches) during a given night, mainly in residential areas, and the duration of these decreased during the night. The probability of a bat revisiting a given foraging area within 48 h varied according to the duration previously spent there, its distance to the roost site, and the corresponding habitat type. We interpret these fine-scale patterns in relation to global habitat quality (including food-resource quality and predictability), habitat-familiarity and experience of each individual. Conclusions: Our study provides evidence that heterogeneous human-made environments may promote complex patterns of foraging-behavior and short-term re-visitation in fruit bat species that occur in such landscapes. This highlights the need for similarly detailed studies to understand the processes that maintain biodiversity in these environments and assess the potential for pathogen transmission in human-wildlife interfaces

Emerging viral threats in Gabon: health capacities and response to the risk of emerging zoonotic diseases in Central Africa

Emerging infectious diseases (EID) are currently the major threat to public health worldwide and most EID events have involved zoonotic infectious agents. Central Africa in general and Gabon in particular are privileged areas for the emergence of zoonotic EIDs. Indeed, human incursions in Gabonese forests for exploitation purposes lead to intensified contacts between humans and wildlife thus generating an increased risk of emergence of zoonotic diseases. In Gabon, 51 endemic or potential endemic viral infectious diseases have been reported. Among them, 22 are of zoonotic origin and involve 12 families of viruses. The most notorious are dengue, yellow fever, ebola, marburg, Rift Valley fever and chikungunya viruses. Potential EID due to wildlife in Gabon are thereby plentiful and need to be inventoried. The Gabonese Public Health system covers geographically most of the country allowing a good access to sanitary information and efficient monitoring of emerging diseases. However, access to treatment and prevention is better in urban areas where medical structures are more developed and financial means are concentrated even though the population is equally distributed between urban and rural areas. In spite of this, Gabon could be a good field for investigating the emergence or re-emergence of zoonotic EID. Indeed Gabonese health research structures such as CIRMF, advantageously located, offer high quality researchers and facilities that study pathogens and wildlife ecology, aiming toward a better understanding of the contact and transmission mechanisms of new pathogens from wildlife to human, the emergence of zoonotic EID and the breaking of species barriers by pathogens

Evidence for Novel Hepaciviruses in Rodents

Hepatitis C virus (HCV) is among the most relevant causes of liver cirrhosis and hepatocellular carcinoma. Research is complicated by a lack of accessible small animal models. The systematic investigation of viruses of small mammals could guide efforts to establish such models, while providing insight into viral evolutionary biology. We have assembled the so-far largest collection of small-mammal samples from around the world, qualified to be screened for bloodborne viruses, including sera and organs from 4,770 roden

Bartonella gabonensis sp. nov., a new bartonella species from savannah rodent Lophuromys sp. in Franceville, Gabon

International audienceWe describe a new strain named Bartonella gabonensis sp. nov. strain 669T (CSURB1083). The entire genome of this strain is described here. It was isolated from a savannah rodent, a brush-furred rat (Lophuromys sp.), trapped the city of Franceville in Gabon, in Central Africa. B. gabonensis is an aerobic, rod-shaped and Gram-negative bacterium. On the basis of the organism's features, and following a taxonogenomic approach, we propose the creation of the species Bartonella gabonensis sp. nov

Foraging and mating behaviors of Hypsignathus monstrosus at the bat-human interface in a central African rainforest

International audienceStudying wildlife space use in human-modified environments contributes to characterize wildlife-human interactions to assess potential risks of zoonotic-pathogens transmission, and to pinpoint conservation issues. In central African rainforests with human dwelling and activities, we conducted a telemetry study on a group of males of Hypsignathus monstrosus, a lek-mating fruit bat identified as a potential maintenance host for Ebola virus. During a lekking season in 2020, we investigated the foraging-habitat selection and the individual nighttime space use during both mating and foraging activities close to villages and their surrounding agricultural landscape. At night, marked individuals strongly selected agricultural lands and more generally areas near watercourses to forage, where they spent more time compared to forest ones. Furthermore, the probability and duration of the presence of bats in the lek during nighttime decreased with the distance to their roost site but remained relatively high within a 10 km radius. Individuals adjusted foraging behaviors according to mating activity by reducing both the overall time spent in foraging areas and the number of forest areas used to forage when they spent more time in the lek. Finally, the probability of a bat revisiting a foraging area in the following 48 hours increased with the previous time spent in that foraging area. These behaviors occurring close to or in human-modified habitats can trigger direct and indirect bat-human contacts, which could thus facilitate pathogen transmission such as Ebola virus

Results of real-time PCR on organs from <i>Coleura afra</i> individuals.

<p>Numbers indicate the cycle threshold (C<i>t</i>). ND, not done because of missing samples.</p><p>Undet, C<i>t</i> undetermined.</p><p>Results of real-time PCR on organs from <i>Coleura afra</i> individuals.</p

Overview of specimens collected in Belinga caves and tested by specific BelPV qPCR assay.

<p>Overview of specimens collected in Belinga caves and tested by specific BelPV qPCR assay.</p

Phylogenetic tree based on a 439-basepair fragment of the polymerase gene (L) of members of the <i>Paramyxoviridae</i> family.

<p>Sequences generated in this study are highlighted in red. Bayesian posterior probabilities are shown; values <0.80 were removed for clarity. The viruses are designated as follows (virus abbreviation/typical host/accession numbers of reference sequences in brackets): HeV  =  Hendra virus, NiV  =  Nipah virus, BatPV  =  Bat paramyxovirus, BeiPV  =  Beilong virus, JPV  = J virus, MosPV  =  Mossman virus, TupPV  =  Tupaia paramyxovirus, NarPV  =  Nariva virus, PDV  =  Phocine distemper virus, CDV  =  Canine distemper virus, CeMV DMV  =  Cetacean morbillivirus strain dolphin morbillivirus, MeV  =  Measles virus, PPRV  =  Peste-des-petits ruminants virus, RPV  =  Rinderpest virus, FdlPV  =  Fer-de-lance virus, PSPV  =  Pacific salmon paramyxovirus, ASPV  =  Atlantic salmon paramyxovirus, SeV  =  Sendai virus, bPIV3  =  Bovine parainfluenza virus 3, hPIV1  =  Human parainfluenza virus 1, hPIV3  =  Human parainfluenza virus 3, SwPIV3  =  Swine parainfluenza virus 3, NDV  =  Newcastle disease virus, PigeonPMV  =  Pigeon paramyxovirus, AMPV9  =  Avian paramyxovirus type 9, AMPV6  =  Avian paramyxovirus type 6, AMPV2  =  Avian paramyxovirus type 2, AMPV3  =  Avian paramyxovirus type 3, AMPV4  =  Avian paramyxovirus type 4, PIV5  =  parainfluenza virus 5, SV41  =  Simian virus 41, MenPV  =  Menangle paramyxovirus, MprPV  =  Mapuera virus, MuV  =  Mumpsvirus, PorPV  =  Porcine rubulavirus, TioPV  =  Tioman paramyxovirus, hPIV2  =  Human parainfluenza virus 2, hMPV  =  Human metapneumovirus, MPV  =  Murine pneumonia virus, bRSV  =  Bovine respiratory syncytial virus, hRSV  =  Human respiratory syncytial virus, APV  =  Avian Pneumovirus, ThkPV-1  =  Tuhoko virus 1, ThkPV-2  =  Tuhoko virus 2, ThkPV-3  =  Tuhoko virus 3.</p