Fruit Bats Research Articles

Histopathological survey of free-ranging neotropical bats with dermatitis.

Bats have a fundamental ecological role, and no wildlife disease has decimated more individuals than white-nose syndrome (WNS). This impactful mycosis has raised the importance of monitoring disease threats to bat populations. In this study, we aimed to investigate gross skin lesions in neotropical bats by histopathology to survey the occurrence of dermatitis that could resemble WNS cases in Brazil. Eleven species of free-ranging bats were sampled from the rabies surveillance program in 9 municipalities of Northern Paraná. Members of the Molossidae family were the most frequent ones among the 126 analyzed individuals, and 4 cases of dermatitis in 2 black mastiff bats (Molossus rufus), 1 great fruit-eating bat (Artibeus lituratus), and a big free-tailed bat (Nyctinomops macrotis) were detected. Gross lesions included alopecia, macules, discoloration, and hyperkeratosis. Among the bats with gross lesions, dermal thickening and mild inflammation were observed histologically. Two M. rufus bats had dermal fungal invasion; however, none resembled WNS.

Morphological, Anatomical, and Physiological Signs of Senescence in the Great Fruit-Eating Bat (Artibeus lituratus)

The longevity of bats is longer than expected based on their small body sizes and high metabolic rate. However, signs of senescence have been poorly studied for free-living bats, especially for Neotropical species, because elderly individuals are challenging to find in the wild, and long-term mark-recapture studies are lacking. Here, we present the first record of a free-living Neotropical frugivorous bat, a female Artibeus lituratus (family Phyllostomidae), with impressive signs of senescence. We compare the elderly bat with conspecific juveniles and non-elderly adults morphologically, anatomically, and physiologically. The most noticeable signs of senescence were a significant loss of fur, dark spots on the skin, excessive dental wear, and reduced ability to assimilate sugar. These traits indicate that bats' challenges as they get old can be associated with reduced thermal insulation, ability to chew, and nutrient assimilation. However, by reducing extrinsic causes of mortality, flying capability in old bats with clear signs of senescence may represent a vital survival trait associated with the long lifespan of these animals.

Influence of Environmental Parameters on the Breeding of an Endemic Malagasy Fruit Bat, Rousettus madagascariensis (Pteropodidae)

The breeding biology of bats is in part regulated by environmental parameters, which in certain cases result in considerable intraspecific variation in reproduction periods. Few details are available on the reproductive behavior of Malagasy bats and this study focuses on parameters related to the mating and parturition periods in the endemic frugivorous and cave-roosting Rousettus madagascariensis (Pteropodidae). The birth period was estimated based on observations of mating behavior and presence of neonates in video recordings made at Ankarana (northern Madagascar) during different seasonal periods in 2017 and 2018. Based on animals captured in the same cave between 2014 and 2022, we also estimated the age of neonates in order to evaluate annual variation in parturition periodicity. Based on video recordings, mating was mainly observed (ordered based on highest frequency) in September, July, and January. This behavior, which generally took place during the dry season, was negatively correlated with temperature and rainfall, and had a low positive correlation with cave relative humidity. With most mating taking place between July and September, one parturition period occurs just before or during the wet season (between December and February), the period of highest fruit abundance in Ankarana. For cases of mating in January, excluding the possibility of sperm storage or delayed implantation, another parturition would occur in mid-April, a time of low fruit availability; however, no neonate was filmed or trapped in April and video recording data indicated that neonates were present between July and September, suggesting a parturition taking place from July to September. Parturition periods show some annual variation and appear to be mainly regulated by climatic aspects including rainfall and principally temperature; however, this variation was less pronounced as compared to other non-Malagasy pteropodid species. Further research on Malagasy fruit bats should focus on possible sperm storage or delayed embryonic development and, if found, associated correlations with environmental parameters.

Surveillance, isolation and genomic characterization of Pteropine orthoreovirus of probable bat origin among patients with acute respiratory infection in Malaysia.

Pteropine orthoreovirus (PRV), an emerging bat-borne virus, has been linked to cases of acute respiratory infections (ARI) in humans. The prevalence, epidemiology and genomic diversity of PRV among ARI of unknown origin were studied. Among 632 urban outpatients tested negative for all known respiratory viruses, 2.2% were PRV-positive. Patients mainly presented with moderate to severe forms of cough, sore throat and muscle ache, but rarely with fever. Phylogenetic analysis revealed that over 90% of patients infected with the Melaka virus (MelV)-like PRV, while one patient infected with the Pulau virus previously found only in fruit bats. Human oral keratinocytes and nasopharyngeal epithelial cells were susceptible to clinical isolates of PRV, including the newly isolated MelV-like 12MYKLU1034. Whole genome sequence of 12MYKLU1034 using Nanopore technique revealed a novel reassortant strain. Evolutionary analysis of the global PRV strains suggests the continuous evolution of PRV through genetic reassortment among PRV strains circulating in human, bats and non-human primate hosts, creating a spectrum of reassortant lineages with complex evolutionary characteristics. In summary, the role of PRV as a common etiologic agent of ARI is evident. Continuous monitoring of PRV prevalence, pathogenicity and diversity among human and animal hosts is important to trace the emergence of novel reassortants.

SARS-CoV-2 in animals: susceptibility of animal species, risk for animal and public health, monitoring, prevention and control.

The epidemiological situation of SARS-CoV-2 in humans and animals is continually evolving. To date, animal species known to transmit SARS-CoV-2 are American mink, raccoon dog, cat, ferret, hamster, house mouse, Egyptian fruit bat, deer mouse and white-tailed deer. Among farmed animals, American mink have the highest likelihood to become infected from humans or animals and further transmit SARS-CoV-2. In the EU, 44 outbreaks were reported in 2021 in mink farms in seven MSs, while only six in 2022 in two MSs, thus representing a decreasing trend. The introduction of SARS-CoV-2 into mink farms is usually via infected humans; this can be controlled by systematically testing people entering farms and adequate biosecurity. The current most appropriate monitoring approach for mink is the outbreak confirmation based on suspicion, testing dead or clinically sick animals in case of increased mortality or positive farm personnel and the genomic surveillance of virus variants. The genomic analysis of SARS-CoV-2 showed mink-specific clusters with a potential to spill back into the human population. Among companion animals, cats, ferrets and hamsters are those at highest risk of SARS-CoV-2 infection, which most likely originates from an infected human, and which has no or very low impact on virus circulation in the human population. Among wild animals (including zoo animals), mostly carnivores, great apes and white-tailed deer have been reported to be naturally infected by SARS-CoV-2. In the EU, no cases of infected wildlife have been reported so far. Proper disposal of human waste is advised to reduce the risks of spill-over of SARS-CoV-2 to wildlife. Furthermore, contact with wildlife, especially if sick or dead, should be minimised. No specific monitoring for wildlife is recommended apart from testing hunter-harvested animals with clinical signs or found-dead. Bats should be monitored as a natural host of many coronaviruses.

Home ranges, directionality and the influence of moon phases on the movement ecology of Indian flying fox males in southern India.

Flying foxes of the genus Pteropus are amongst the largest fruit bats and potential long-range pollinators and seed dispersers in the paleotropics. Pteropus giganteus (currently P. medius) is the only flying fox that is distributed throughout the Indian mainland, including in urban and rural areas. Using GPS telemetry, we mapped the home ranges and examined flight patterns in P. giganteus males across moon phases in a semi-urban landscape in southern India. Home range differed between the tracked males (n=4), likely due to differences in their experience in the landscape. We found that nightly time spent outside the roost, distance commuted and the number of sites visited by tracked individuals did not differ significantly between moon phases. In 61% of total tracked nights across bats, the first foraging site was within 45˚ of the emergence direction. At the colony-level, scan-based observations showed emergence flights were mostly in the northeast (27%), west (22%) and southwest (19%) directions that could potentially be related to the distribution of foraging resources. The movement ecology of fruit bats in relation to the pollination and seed dispersal services they provide requires to be investigated in future studies. This article has an associated First Person interview with the first author of the paper.

Potential Mammalian Vector-Borne Diseases in Live and Wet Markets in Indonesia and Myanmar

Vector-borne diseases spread from wild animals and their associated ectoparasites to humans and domesticated animals. Wildlife markets are recognized as important areas where this transfer can take place. We assessed the potential for spreading vector-borne diseases in two live and wet markets in Myanmar (Mong La, on the Myanmar-China border) and Indonesia (Sukahaji in Bandung on the island of Java) by making an inventory of all live and freshly killed wild mammals for sale. For eight mammal families, we quantified the number of animals on offer, and we used a heatmap cluster analysis to map vector-borne diseases that these families may carry. In Myanmar, we observed large numbers of wild pigs and deer (potentially carrying West Nile and various encephalitis viruses) whereas in Indonesia we observed Old World fruit bats (potentially carrying Chikungunya and encephalitis viruses) and squirrels (potentially carrying West Nile and encephalitis viruses). The trade in Indonesia was dominated by live mammals offered for sale as pets, and only Old World fruit bats and squirrels traded for traditional Asian medicine were killed in the markets. The trade in Myanmar was more geared towards wild meat (e.g., wild pigs, deer, primates) and traditional Asian medicine (squirrels). The combined risks of vector-borne diseases spreading from traded animals to human health highlight the need for an integrated approach protecting public health, economic interests and biodiversity.

Genetic diversity within and among populations of the fulvous fruit bat Rousettus leschenaulti using RAPD analysis

Genetic diversity within and among populations of the fulvous fruit bat Rousettus leschenaulti using RAPD analysis

Ebola Virus Disease (Evd): Nigeria Perspective

The deadly but uncommon Ebola virus disease affects both humans and primates (EVD). The Ebola virus causes a severe form of hemorrhagic fever in which the victim’s blood clots abnormally, leading to internal bleeding. After initial contact with the virus, "dry" symptoms such as fever, aches and pains, and exhaustion typically appear, followed by "wet" symptoms such as diarrhoea and vomiting anywhere from two to twenty-one days (on average, eight to ten) later Virologists believe Laupland and Valiquette are hosting the virus. It is believed that the onlyway for the Ebola virus to spread is through direct contact between people and blood or other body fluids from a person showing symptoms of the disease. Saliva, mucus, vomit, faeces, tears, perspiration, breast milk, urine, and sperm all contain the Ebola virus. The term "spillover" is used to describe the zoonotic spread of the Ebola virus from infected hosts like the fruit bat or nonhuman primates to other animals. The Ebola virus is amember of the viral family known as Filoviridae in the order of Mononegavirales the Marburg virus is also. Ebola virus infection can be diagnosed through a variety of techniques, including electron microscopy, antigen capture detection tests, serum neutralisation tests, reverse transcriptase polymerase chain reaction (RT PCR) assays, antibody-capture enzyme-linked immunosorbent assays (ELISAs), and virus isolation through cell culture. The term "Ebola vaccine" refers to both already available and planned vaccines against the virus. Only Zaire ebolavirus and rVSV-ZEBOV vaccines are effective against this disease. Treatment that is purely supportive, such as relieving patients of their symptoms and giving them water orally or intravenously, does not improve prognosis. This research intends to give Nigerians an up-to-date picture of the spread of EVD in the country in the wake of the recent pandemic in neighboring Uganda.

Molecular evidence of Borrelia spp. in bats from Córdoba Department, northwest Colombia

BackgroundThe genus Borrelia is composed of two well-defined monophyletic groups, the Borrelia burgdorferi sensu lato complex (Bb) and the relapsing fever (RF) group borreliae. Recently, a third group, associated with reptiles and echidnas, has been described. In general, RF group borreliae use rodents as reservoir hosts; although neotropical bats may also be involved as important hosts, with scarce knowledge regarding this association. The objective of this study was to detect the presence of Borrelia spp. DNA in bats from the department of Córdoba in northwest Colombia.MethodsDuring September 2020 and June 2021, 205 bats were captured in six municipalities of Córdoba department, Colombia. Specimens were identified using taxonomic keys and DNA was extracted from spleen samples. A Borrelia-specific real-time PCR was performed for the 16S rRNA gene. Fragments of the 16S rRNA and flaB genes were amplified in the positive samples by conventional PCR. The detected amplicons were sequenced by the Sanger method. Phylogenetic reconstruction was performed in IQ-TREE with maximum likelihood based on the substitution model TPM3+F+I+G4 with bootstrap values deduced from 1000 replicates.ResultsOverall, 10.2% (21/205) of the samples were found positive by qPCR; of these, 81% (17/21) and 66.6% (14/21) amplified 16S rRNA and flaB genes, respectively. qPCR-positive samples were then subjected to conventional nested and semi-nested PCR to amplify 16S rRNA and flaB gene fragments. Nine positive samples for both genes were sequenced, and seven and six sequences were of good quality for the 16S rRNA and flaB genes, respectively. The DNA of Borrelia spp. was detected in the insectivorous and fruit bats Artibeus lituratus, Carollia perspicillata, Glossophaga soricina, Phyllostomus discolor, and Uroderma sp. The 16S rRNA gene sequences showed 97.66–98.47% identity with “Borrelia sp. clone Omi3,” “Borrelia sp. RT1S,” and Borrelia sp. 2374; the closest identities for the flaB gene were 94.02–98.04% with “Borrelia sp. Macaregua.” For the 16S rRNA gene, the phylogenetic analysis showed a grouping with “Candidatus Borrelia ivorensis” and “Ca. Borrelia africana,” and for the flaB gene showed a grouping with Borrelia sp. Macaregua and Borrelia sp. Potiretama. The pathogenic role of the Borrelia detected in this study is unknown.ConclusionsWe describe the first molecular evidence of Borrelia spp. in the department of Córdoba, Colombia, highlighting that several bat species harbor Borrelia spirochetes.Graphical

Phylogenetic and genetic variation analysis of lesser short-nosed fruit bat Cynopterus brachyotis (Müller 1838) on Java island, Indonesia, inferred from mitochondrial D-loop

BackgroundCynopterus brachyotis (Müller 1838) is a generalist and widespread fruit bat species which inhabits different types of habitats in Southeast Asia. This species plays an essential role as a seed disperser and pollinator. Morphological study and phylogenetic analysis using mtDNA markers (cyt-b and D-loop) revealed that this species had two different forms in peninsular Malaysia and Borneo and six lineages in Southeast Asia that lead to new species formation. In addition, this species is also reported to have high genetic diversity in Malaysia and Thailand based on the D-loop sequence. However, a phylogenetic and genetic variation study of C. brachyotis in Indonesia has not been conducted yet. These two studies are important as additional information for taxonomic and population genetic studies of this species. Thus, we performed the phylogenetic and genetic diversity analysis of the C. brachyotis population collected from seven habitats on Java island, including open-fragmented habitats (urban, coffee and rubber plantations, pine forest, secondary forest, mangrove forest) and closed habitats (natural forest) using the mtDNA D-loop marker. ResultsThe phylogenetic tree using the Bayesian inference (BI) and genetic distance using the Kimura-2 parameter (K-2P) demonstrated that 33 individuals of C. brachyotis from seven habitats on Java island overlapped between habitats and could not be distinguished according to their habitats and lineage. Intrapopulation and intraspecies analysis revealed high haplotype diversity of this species on Java island (Hd = 0.933–1.000). The haplotype network was split into two haplogroups, showing haplotype sharing between habitats. These phylogenetic and genetic variations analysis of C. brachyotis bats on Java island indicated that this species is widespread and adapt to different habitats. ConclusionsThis study of C. brachyotis on Java island collected from seven different habitats has overlapped and genetically close and has high genetic variation. Our results provide the first reported study of C. brachyotis on Java island and provide data to understand the phylogenetic and genetic diversity of this species in Indonesia.

A compartmental model for the spread of Nipah virus in a periodic environment

<abstract><p>Nipah virus (NiV) is a zoonotic virus that causes outbreaks of fatal disease in humans. Fruit bat, also known as the flying fox, is the animal host reservoir for NiV. It is known to cause illness in pigs, which are considered an intermediate host. In this paper, we propose a model for NiV disease transmission taking into account all human-to-host animal transmission as well as the loss of immunity in those who have recovered. Furthermore, we take into consideration seasonal effects such as varying transmission rate from bats and birth rate of bats. We studied the existence and uniqueness of a disease-free $ \omega $-periodic solution and later deals with the basic reproduction number and stability analysis. To support the analytical results we provide numerical examples and assess the effect of parameter changes on disease dynamics, which might help to understand how to avoid a yearly periodic recurrence of the disease.</p></abstract>

4 Origin Scenarios if a Nipah Virus outbreak occurs outside South/SE Asia

Nipah virus is a bat-borne zoonotic RNA virus discovered in Malaysia during an 1998-1999 outbreak that involved pigs, fruit bats, and humans in Malaysia (1). Clinical manifestations are primarily encephalitis and pneumonia. The case fatality rate of symptomatic cases is 40%-70%. Survivors can have severe neurologic sequelae (2-5). There are no licensed vaccines, antiviral drugs, monoclonal antibodies, or point-of-care rapid diagnostic tests, although extensive work on vaccines and monoclonal antibodies is underway (6). Person-to-person transmission, including a small number of superspreading events, has occurred in Bangladesh and India (7-9). From 1998-2023 all reported outbreaks have been in either southeast (SE) Asia (Malaysia, Singapore, the Philippines), or south Asia (Bangladesh, India) (2, 7-10). It is likely that a future Nipah outbreak, and possibly widespread epidemic, will occur outside south/SE Asia, whether elsewhere in Asia such as China, or on another continent. When it does, then as with the COVID-19 pandemic, multiple questions will be raised regarding the origin of the epidemic. Each of the following four (4) main scenarios could be anticipated to account for the origin of such a geographically-unprecedented Nipah epidemic during analysis on Day 1 of the event by national and international organizations.

Study of Fractional Order Dynamical System of Viral Infection Disease under Piecewise Derivative

This research aims to understand the fractional order dynamics of the deadly Nipah virus (NiV) disease. We focus on using piecewise derivatives in the context of classical and singular kernels of power operators in the Caputo sense to investigate the crossover behavior of the considered dynamical system. We establish some qualitative results about the existence and uniqueness of the solution to the proposed problem. By utilizing the Newtonian polynomials interpolation technique, we recall a powerful algorithm to interpret the numerical findings for the aforesaid model. Here, we remark that the said viral infection is caused by an RNA type virus which can transmit from animals and also from an infected person to person. Fruits bats which are also known as flying foxes are one of the sources of transmission of NiV disease. Here in this work, we investigate its transmission mechanism through some new concepts of fractional calculus for further analysis and prediction. We present the approximate results for different compartments using different fractional orders. By using the piecewise derivative concept, we detect the crossover or multi-steps behavior in the transmission dynamics of the mentioned disease. Therefore, the considered form of the derivative is used to deal with problems exhibiting crossover behaviors.

Loss of biodiversity: a one-way ticket to new emerging diseases?

To feed and house the 8 billion people on this planet, large-scale land use changes are causing biodiversity to decline at an unprecedented rate. The frontier between wildlife, humans and domestic animals is shrinking day by day and favors the passage of pathogens between these different reservoirs. The health crisis caused by the Nipah virus, the result of a viral passage between fruit bats, pigs and humans is a perfect example. The consumption of bushmeat and the sale of wild animals in markets where livestock and wild animals mix amplify these transmission risks. Only a multidisciplinary globalized public health approach can anticipate and reduce the risks of a future pandemic.

Glyphosate Alters Redox Balance and Induces Histomorphological Alterations in the Testes of Fruit-Eating Bats (Artibeus lituratus)

We investigate the effects of Glyphosate (GLY) on the testes of fruit-eating bats (Artibeus lituratus). Our study aimed to evaluate the effects of short-time exposure to GLY herbicide on adult male bats testes. Adult male bats were exposed for three days: Control (fed fresh fruits) and GLY (fed 4 mL / 100 mL GLY-pulverized fruit). Animals fed with contaminated fruits showed a reduction in body mass. Antioxidant enzyme catalase (CAT) activity and carbonylated protein (PCN) levels increased in the teste’s GLY-exposed bats. Histomorphometry revealed an increase in the luminal parameters as well as in the epithelium tubule ratio, which is indicative of a reduction in epithelium area. There was also an increase in the percentage of macrophages and a decrease in the percentage and number of Leydig cells. The results indicate that short term exposure to GLY in frugivorous bats may cause oxidative stress of the tissue that possibly induces testicular morphological changes that may compromise the reproduction and maintenance of the species.

Seasonal changes in the localization of cytokeratin AE1, alpha-smooth muscle actin, and S100 proteins in the testis and epididymis of the African Fruit Bat (Epomops franqueti

Seasonal changes in the localization of cytokeratin AE1, alpha-smooth muscle actin, and S100 proteins in the testis and epididymis of the African Fruit Bat (Epomops franqueti

Overview of Experimental Vaccines and Antiviral Therapeutics for Henipavirus Infection.

Hendra virus (HeV) and Nipah virus (NiV) are highly pathogenic paramyxoviruses, which have emerged in recent decades and cause sporadic outbreaks of respiratory and encephalitic disease in Australia and Southeast Asia, respectively. Over two billion people currently live in regions potentially at risk due to the wide range of the Pteropus fruit bat reservoir, yet there are no approved vaccines or therapeutics to protect against or treat henipavirus disease. In recent years, significant progress has been made toward developing various experimental vaccine platforms and therapeutics. Here, we describe these advances for both human and livestock vaccine candidates and discuss the numerous preclinical studies and the few that have progressed to human phase 1 clinical trial and the one approved veterinary vaccine.

Anatomy and homology of the caudal auricular muscles in greater short-nosed fruit bat (Cynopterus sphinx).

Bats can be phylogenetically classified into three major groups: pteropodids, rhinolophoids, and yangochiropterans. While rhinolophoids and yangochiropterans are capable of laryngeal echolocation, pteropodids lack this ability. Delicate ear movements are essential for echolocation behavior in bats with laryngeal echolocation. Caudal auricular muscles, especially the cervicoauricularis group, play a critical role in such ear movements. Previously, caudal auricular muscles were studied in three species of bats with laryngeal echolocation, but to our knowledge, there have been no studies on non-laryngeal echolocators, the pteropodids. Here, we describe the gross anatomy of the cervicoauricularis muscles and their innervation in Cynopterus sphinx by using diffusible iodine-based contrast-enhanced computed tomography and 3D reconstructions of immunohistochemically stained serial sections. A previous study on bats with laryngeal echolocation reported that rhinolophoids have four cervicoauricularis muscles and yangochiropterans have three. We observed three cervicoauricularis muscles in the pteropodid C. sphinx. The number of cervicoauricularis muscles and their innervation pattern were comparable to those of non-bat boreoeutherian mammals and yangochiropterans, suggesting that pteropodids, and yangochiropterans maintain the general condition of boreoeutherian mammals and that rhinolophoids have a derived condition. The unique nomenclature had been previously applied to the cervicoauricularis muscles of bats with laryngeal echolocation, but given the commonality between non-bat laurasiatherians and bats, with the exception of rhinolophoids, maintaining the conventional nomenclature (i.e., M. cervicoauricularis superficialis, M. cervicoauricularis medius, and M. cervicoauricularis profundus) is proposed for bats.

Nipah Virus: A Threatening Outbreak

Nipah Virus (NiV) first identified in Malaysia in 1998, was found to be a highly pathogenic re-emerging paramyxovirus able to produce febrile encephalitis and respiratory sickness for which there are no vaccinations or approved therapies present. Pteropus species bats act as the main natural reservoir. NiV comes under level-4 in biosafety and most commonly spreads through Pteropus fruit bat saliva or excrement, or through close contact with intermediate hosts such as pigs. This virus is predominantly common in Southeast Asia and is considered one of the deadliest viruses in the world with the highest mortality rates. Different strains of the virus were found to display different epidemiological and clinical features. In order to contain outbreaks, quick diagnosis and infection control measures are needed. For diagnosis and surveillance, varieties of serological and molecular diagnostic approaches have been developed. Here, the authors review the current concepts in NiV genome, structure, replication, epidemiology, different viral strains, pathogenesis, clinical signs and symptoms, diagnosis, treatment, vaccines and prevention in human beings.