Biology subjects

Cappelle, J.

Publications and source records attributed to Cappelle, J..

7 recordsLinked to original sources

bioRxiv2026

Sarbecovirus-associated gut microbiome instability in a natural bat reservoir

Sarbecoviruses, a subgenus of Betacoronavirus, display both respiratory and gastrointestinal tropism, suggesting potential interactions with host gut microbial communities. However, ecological signatures of infection in wild bats remain poorly understood. We investigated associations between Sarbecovirus infection status, gut microbiome structure, and diet composition in Rhinolophus shameli roosting in northeastern Cambodia. Fecal samples collected across dry and wet seasons (2023-2024) were subject to full-length 16S rRNA gene sequencing and arthropod DNA metabarcoding. Sarbecovirus-positive bats exhibited stable alpha diversity but consistent shifts in gut community composition and increased interindividual variability consistent with the Anna Karenina Principle, suggesting infection-associated destabilization of community assembly rather than diversity erosion. Infection status was associated with enrichment of Shigella and Escherichia species, taxa linked to inflammatory or epithelial stress states in bats. In contrast, dietary composition showed no strong global structuring by infection status and weak coupling with bacterial community structure, suggesting that trophic ecology is unlikely to be the main driver of the infection-associated microbiome signal. Although causal directionality cannot be inferred, our results reveal measurable and consistent microbiome restructuring associated with Sarbecovirus detection in a natural reservoir host and highlight the potential of microbiome profiling for monitoring wildlife disease processes.

ecology↗

bioRxiv2025

Characterization and evolutionary history of novel SARS-CoV-2-related viruses in bats from Cambodia

Circulating bat coronaviruses present a significant pandemic threat, yet our understanding of their genetic diversity and evolutionary dynamics remains limited. Over 3 years, we sampled 1,462 bats in Cambodias Steung Treng province, identifying extensive and diverse coronaviruses co-circulation. Using metatranscriptomic and amplicon sequencing, we generated 33 complete sarbecovirus genomes, revealing novel lineages that cluster into four distinct groups, each associated with different Rhinolophus bat species. Our analysis highlights rapid migration and recombination of sarbecovirus lineages over short distances and timescales. Of note, the receptor-binding domains of two novel viral groups exhibit high similarity to SARS-CoV-2, and pseudovirus assays confirmed the ability of this spike protein to mediate entry into cells expressing human ACE2, suggesting a potential zoonotic risk. The observed genetic diversity underscores the urgent need for continuous surveillance to identify high-risk animal-to-human interfaces and inform pandemic preparedness.

microbiology↗

bioRxiv2024

Pear (Pyrus communis L. cv. Conference) has shade-tolerant features allowing for consistent agrivoltaic crop yield

Transitioning to a fossil fuel free society requires an increase in solar energy production. However, expanding solar power to farmland competes with food production. Additionally, climate change threatens food security and leads increasingly to yield losses. Agrivoltaics (AV) systems produce solar energy and food on the same field, while sheltering crops. In AV systems, crops grow in a modified environment with reduced solar irradiance, a tempered microclimate and a potential physical cover protecting against hail damage. This research describes pear production under an AV pilot with 24% light reduction for 3 consecutive seasons. AV pear trees yielded 14% less than the reference. Flowering and fruit set was unchanged while AV reduced leaf flavonoid levels. The leaf photosynthetic light response was identical, yet a delayed leaf senescence under AV suggests an adaptation to the modified environment. AV impacted fruit shape, as there was an increase in the number of bottle shaped pears and a reduction in caliber. Other fruit quality traits were broadly unaffected, yet postharvest ethylene production was higher for AV fruit in 2022 than for the control. This study demonstrates that AV systems hold potential for pear production under temperate climates and highlights plant adaptations that make this possible. HighlightPear cultivation in agrivoltaic systems integrates renewable energy and sustainable fruit production. This study provides insights into crop yield, fruit quality, and plant adaptation towards an agrivoltaic environment.

plant biology↗

bioRxiv2023

Effects of biological and environmental factors on filovirus serology in bats in Guinea

BackgroundOutbreaks of Ebola disease emerge regularly in human populations on the African continent. This highly virulent haemorrhagic fever can be caused by different orthoebolaviruses from the Filoviridae family. Several bat species are believed to carry and transmit some of these viruses to people or other animal species. However, clear evidence is still lacking. Natural circulation and zoonotic transmissions of viruses are generally complex as they often involve several host species and are influenced by biological, environmental and anthropogenic factors. A better understanding of the role of bats and other wildlife in the emergence of Ebola disease outbreaks is crucial for their prevention and early detection. MethodsIn this longitudinal study we searched for antibodies against orthoebolaviruses in fruit bats in order to explore some of the factors which might influence their natural circulation. We performed serological tests on populations of 4 bat species (Eidolon helvum, Hypsignathus monstrosus, Myonycteris angolensis and Rousettus aegyptiacus) sampled longitudinally for 18 months (2018-2020) in Guinea. The analysis of 1,427 bat samples for antibodies directed against different orthoebolavirus species allowed us to test the influence of biological and environmental variables on seropositivity by using GLMM. ResultsResults showed that the presence of antibodies against one of the orthoebolaviruses antigen is more frequent in the Eidolon helvum and Rousettus aegyptiacus species, in males, in sexually immature adults, and during the dry season. ConclusionOur results suggest that host species, sex, age, reproductive life-cycle and season may play an important role in the circulation of filoviruses. This information can be used to guide further sampling to specifically characterize the orthoebolavirus species underlying the production of these antibodies and to adjust surveillance protocols at the interface between bats, humans and other animals.

microbiology↗

bioRxiv2023

A Bayesian analysis of birth pulse effects on the probability of detecting Ebola virus in fruit bats

Since 1976 various species of Ebolavirus have caused a series of zoonotic outbreaks and public health crises in Africa. Bats have long been hypothesised to function as important hosts for ebolavirus maintenance, however the transmission ecology for these viruses remains poorly understood. Several studies have demon-strated rapid seroconversion for ebolavirus antibodies in young bats, yet paradoxically few PCR studies have confirmed the identity of the circulating viral species causing these seroconversions. The current study presents an age-structured epidemiological model that characterises the effects of seasonal birth pulses on ebolavirus transmission within a colony of African straw-coloured fruit bats (Eidolon helvum). Bayesian calibration is performed using previously published serological data collected from Cameroon, and age-structure data from Ghana. The model predicts that annual birth pulses most likely give rise to annual outbreaks, although more complex dynamic patterns - including skip years, multi-annual cycles and chaos - may be possible. Weeks 30 to 31 of each year were estimated to be the most likely period for isolating the circulating virus in Cameroon. The probability that a previous PCR campaign failed to detect Ebola virus, assuming that it was circulating, was estimated to be one in two thousand. This raises questions such as (1) what can we actually learn from ebolavirus serology tests performed without positive controls? (2) are current PCR tests sufficiently sensitive? (3) are swab samples really appropriate for ebolavirus detection? The current results provide important insights for the design of future field studies aiming to detect Ebola viruses from sylvatic hosts, and can contribute to risk assessments concerning the timing of zoonotic outbreaks.

ecology↗

bioRxiv2023

Longitudinal Survey of Astrovirus infection in different bat species in Zimbabwe: Evidence of high genetic Astrovirus diversity

Astroviruses (AstVs) have been discovered in over 80 animal species including diverse bat species and avian species. A study on Astrovirus circulation and diversity in different insectivorous and frugivorous chiropteran species roosting in trees, caves and building basements was carried out at 11 different sites across Zimbabwe. Pooled and individual faecal sampling methods were used for this study, with collection dates ranging from June 2016 to July 2021. In two sites, Magweto and Chirundu, sampling was carried out at monthly intervals from August 2020 to July 2021. Astroviruses and bat mitochondrial genes were amplified using pan-AstVs and CytB /12S RNA PCR systems respectively. Phylogenetic analysis of the RdRp Astrovirus sequences revealed a high genetic diversity of astroviruses. All the bat astroviruses tested in this study clustered with the Mamastrovirus genus. Two distinct groups of amplified sequences were identified. One group was comprised of sequences isolated from Hipposideros, Rhinolophus and Eidolon helvum spp. clustered with Human Astrovirus strains: HuAstV types1-6, HuAstV-MLB1-3 and HuAstV-VA-1. The second group comprising the majority of the sequences clustered with different strains of Bat AstVs. Results from the longitudinal study at Magweto and Chirundu showed an overall AstV prevalence of 13.7% and 10.4% respectively. Peaks of AstV infection at Chirundu coincided with the period when juveniles are 4-6 months old. By combining data from our previous work on Coronaviruses, we also anaylzed co-infection of bats with Coronaviruses and Astroviruses at Magweto and Chirundu sites for which the prevalence of co-infection was 2.6% and 3.5% respectively.

molecular biology↗

bioRxiv2018

Modelling and assessment of combining gilt vaccination, vector control and pig herd management to control Japanese Encephalitis virus transmission in Southeast Asia

Despite existence of human vaccines, Japanese Encephalitis (JE) remains a prominent public health problem in Southeast Asia (SEA). JE is caused by a Flavivirus which is transmitted between pigs, the main amplifying hosts, by Culex mosquito bites. Therefore, sow vaccination, pig herd management and vector control -or a combination of these three potential control measures, might constitute additional control measures contributing to reduce JE health impact in humans, and economic losses in pig farms. We built a deterministic metapopulation model, combining a pig and a Culex mosquito vector population, to represent JE virus (JEV) transmission dynamic within a pig herd. The dynamic of the epidemiological systems resulted from an infectious process, operating in continuous time, combined with the pig breeding process that was modeled based on discrete events occurring instantaneously. We used this model to simulate JEV transmission within a continuum of plausible pig breeding systems encountered in SEA, ranging from backyards to semi-commercial systems. We then analyzed the joint effects of the three tested control measures, namely sow vaccination, pig herd management and vector control, on several indicators characterizing (i) the ability of different pig breeding systems to be simultaneously profitable and allow JEV eradication in the herd, (ii) the impact of JE on pig production and the profitability of gilt vaccination, and (iii) the risk for human beings living in the vicinity of pig herds and/or near pig slaughterhouses. According to our model, herd management has no effect on JEV circulation. Vector control alone is a major control tool but shows paradoxical effects that should be considered in any mosquito based control strategy. Combining sow vaccination and vector control could be an alternative or an additional measure to human vaccination to efficiently reduce both JE incidence in humans and the economic impact of JE infection on pig farms.\n\nAuthor summaryJapanese Encephalitis (JE) still has an important impact on human health in Southeast Asia. Human vaccination is an efficient tool to protect humans but it may not be effective against emerging strains, and poor or remote population may not be able to afford it. Severe outbreaks still occur. JE virus (JEV) is primarily transmitted between pigs and mosquitoes. When infected after sexual maturity, pigs show reproduction disorders leading to economic losses. We propose a modelling approach to investigate the joint effect of three additional control measures, namely sow vaccination, vector control, and pig herd management on JEV transmission dynamic, risk for humans and pigs, and pig breeding sustainability. According to our results, vector control, associated or not with sow vaccination, may be an efficient tool to reduce JE incidence in both human and pigs.

epidemiology↗