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Kevin J Olival - One of the best experts on this subject based on the ideXlab platform.
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Lack of population genetic structure and host specificity in the bat fly, Cyclopodia horsfieldi, across species of Pteropus bats in Southeast Asia
Parasites & Vectors, 2013Co-Authors: Kevin J Olival, Katharina Dittmar, Nancy B. Simmons, Susan L. Perkins, Peter Daszak, Carl W Dick, Juan Carlos Morales, Don J Melnick, Rob DesalleAbstract:Background Population-level studies of parasites have the potential to elucidate patterns of host movement and cross-species interactions that are not evident from host genealogy alone. Bat flies are obligate and generally host-specific blood-feeding parasites of bats. Old-World flies in the family Nycteribiidae are entirely wingless and depend on their hosts for long-distance dispersal; their population genetics has been unstudied to date. Methods We collected a total of 125 bat flies from three Pteropus species ( Pteropus vampyrus, P. hypomelanus , and P. lylei ) from eight localities in Malaysia, Cambodia, and Vietnam. We identified specimens morphologically and then sequenced three mitochondrial DNA gene fragments (CoI, CoII, cytB; 1744 basepairs total) from a subset of 45 bat flies. We measured genetic diversity, molecular variance, and population genetic subdivision (F_ST), and used phylogenetic and haplotype network analyses to quantify parasite genetic structure across host species and localities. Results All flies were identified as Cyclopodia horsfieldi with the exception of two individuals of Eucampsipoda sundaica . Low levels of population genetic structure were detected between populations of Cyclopodia horsfieldi from across a wide geographic range (~1000 km), and tests for isolation by distance were rejected. AMOVA results support a lack of geographic and host-specific population structure, with molecular variance primarily partitioned within populations. Pairwise F_ST values from flies collected from island populations of Pteropus hypomelanus in East and West Peninsular Malaysia supported predictions based on previous studies of host genetic structure. Conclusions The lack of population genetic structure and morphological variation observed in Cyclopodia horsfieldi is most likely due to frequent contact between flying fox species and subsequent high levels of parasite gene flow. Specifically, we suggest that Pteropus vampyrus may facilitate movement of bat flies between the three Pteropus species in the region. We demonstrate the utility of parasite genetics as an additional layer of information to measure host movement and interspecific host contact. These approaches may have wide implications for understanding zoonotic, epizootic, and enzootic disease dynamics. Bat flies may play a role as vectors of disease in bats, and their competence as vectors of bacterial and/or viral pathogens is in need of further investigation.
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lack of population genetic structure and host specificity in the bat fly cyclopodia horsfieldi across species of Pteropus bats in southeast asia
Parasites & Vectors, 2013Co-Authors: Katharina Dittmar, Nancy B. Simmons, Kevin J Olival, Carl W Dick, Juan Carlos Morales, Don J MelnickAbstract:Population-level studies of parasites have the potential to elucidate patterns of host movement and cross-species interactions that are not evident from host genealogy alone. Bat flies are obligate and generally host-specific blood-feeding parasites of bats. Old-World flies in the family Nycteribiidae are entirely wingless and depend on their hosts for long-distance dispersal; their population genetics has been unstudied to date. We collected a total of 125 bat flies from three Pteropus species (Pteropus vampyrus, P. hypomelanus, and P. lylei) from eight localities in Malaysia, Cambodia, and Vietnam. We identified specimens morphologically and then sequenced three mitochondrial DNA gene fragments (CoI, CoII, cytB; 1744 basepairs total) from a subset of 45 bat flies. We measured genetic diversity, molecular variance, and population genetic subdivision (FST), and used phylogenetic and haplotype network analyses to quantify parasite genetic structure across host species and localities. All flies were identified as Cyclopodia horsfieldi with the exception of two individuals of Eucampsipoda sundaica. Low levels of population genetic structure were detected between populations of Cyclopodia horsfieldi from across a wide geographic range (~1000 km), and tests for isolation by distance were rejected. AMOVA results support a lack of geographic and host-specific population structure, with molecular variance primarily partitioned within populations. Pairwise FST values from flies collected from island populations of Pteropus hypomelanus in East and West Peninsular Malaysia supported predictions based on previous studies of host genetic structure. The lack of population genetic structure and morphological variation observed in Cyclopodia horsfieldi is most likely due to frequent contact between flying fox species and subsequent high levels of parasite gene flow. Specifically, we suggest that Pteropus vampyrus may facilitate movement of bat flies between the three Pteropus species in the region. We demonstrate the utility of parasite genetics as an additional layer of information to measure host movement and interspecific host contact. These approaches may have wide implications for understanding zoonotic, epizootic, and enzootic disease dynamics. Bat flies may play a role as vectors of disease in bats, and their competence as vectors of bacterial and/or viral pathogens is in need of further investigation.
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characterization of nipah virus from naturally infected Pteropus vampyrus bats malaysia
Emerging Infectious Diseases, 2010Co-Authors: Sohayati Abdul Rahman, Kevin J Olival, Sharifah Syed Hassan, Maizan Mohamed, Liyen Chang, Latiffah Hassan, Norsharina M Saad, Syamsiah A Shohaimi, Zaini C Mamat, Jonathan H. EpsteinAbstract:We isolated and characterized Nipah virus (NiV) from Pteropus vampyrus bats, the putative reservoir for the 1998 outbreak in Malaysia, and provide evidence of viral recrudescence. This isolate is monophyletic with previous NiVs in combined analysis, and the nucleocapsid gene phylogeny suggests that similar strains of NiV are co-circulating in sympatric reservoir species.
Hume Field - One of the best experts on this subject based on the ideXlab platform.
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Hematology and Plasma Biochemistry of Wild Spectacled Flying Foxes ( Pteropus conspicillatus) in Australia.
Journal of Wildlife Diseases, 2018Co-Authors: Lee Mcmichael, Joanne Meers, Adam Mckeown, David G. Mayer, Steven R. Kopp, Cecilia A. Sánchez, Hume FieldAbstract:The spectacled flying fox (Pteropus conspicillatus) is listed as vulnerable to extinction in Australia. The species' restricted population is in decline, putatively attributed to decreasing habitat, climatic extremes, anthropogenic activities, and more recently, mass mortality events associated with tick paralysis and neonatal cleft palate syndrome. Knowledge of fundamental physiologic parameters of the species is limited. To address this knowledge gap, we sampled 50 wild-caught adult spectacled flying foxes in June (winter) in Far North Queensland, Australia. Hematologic and plasma biochemistry reference ranges were established, and a suite of urine biochemistry analytes were measured. Analyte values were compared within spectacled flying fox sex cohorts and between the spectacled flying fox and the paraphyletic black flying fox (Pteropus alecto). Significant differences in multiple analytes (including erythrocyte, leucocyte, plasma, and urine biochemistry) were found between spectacled flying fox sex cohorts. The majority of spectacled flying fox analyte values did not differ significantly from black flying fox values. Of those analytes that differed between species (erythrocyte, platelet, eosinophil, liver enzyme, and triglyceride levels), the majority were plausibly explained by intraerythrocyte parasite burden and food resource type. Our findings provide baseline data essential to measure and meaningfully interpret flying fox population health in ecologic, conservation, and epidemiologic contexts.
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Phylogeny of Hepatocystis parasites of Australian flying foxes reveals distinct parasite clade
Elsevier, 2018Co-Authors: Juliane Schaer, Lee Mcmichael, Anita N Gordon, Hume Field, Daniel Russell, Kai Matuschewski, Susan L. Perkins, Michelle PowerAbstract:Hepatocystis parasites are close relatives of mammalian Plasmodium species and infect a range of primates and bats. Here, we present the phylogenetic relationships of Hepatocystis parasites of three Australian flying fox species. Multilocus phylogenetic analysis revealed that Hepatocystis parasites of Pteropus species from Australia and Asia form a distinct clade that is sister to all other Hepatocystis parasites of primates and bats from Africa and Asia. No patterns of host specificity were recovered within the Pteropus-specific parasite clade and the Hepatocystis sequences from all three Australian host species sampled fell into two divergent clades. Keywords: Haemosporida, Hepatocystis, Chiroptera, Malaria, Pteropus, Australi
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genetic diversity and phylogeny of the christmas island flying fox Pteropus melanotus natalis
Journal of Mammalogy, 2017Co-Authors: David N Phalen, Carol De Jong, Gayathri Ganesh, Ashlie Hartigan, Craig Smith, Hume Field, Jane Hall, Karrie RoseAbstract:The Christmas Island flying fox (Pteropus melanotus natalis) is thought to be declining to critically low levels. Mitochondrial sequences of the cytochrome oxidase 1 (CO1) and cytochrome b (Cytb) genes and the D-loop were generated from 28 animals and used with maximum likelihood, Bayesian inference, and maximum parsimony methods to determine its relationship to other Pteropus species. In all analyses, P. m. natalis mapped to a large clade containing Pacific Ocean island and Australian Pteropus species. Analysis using the large numbers of available Cytb sequences for Pteropus showed that P. m. natalis maps to a subclade that contains P. hypomelanus sequences from bats originating from Pulau Panjang, an island off the northeast coast of Java. P. hypomelanus was found to be polyphyletic, mapping to 3 separate subclades. These 3 genetically and geographically defined populations are likely to represent 3 separate species. Eighteen D-loop haplotypes were identified, suggesting that P. m. natalis maintains a degree of genetic diversity similar to other insular flying fox species.
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PHYSIOLOGIC BIOMARKERS AND HENDRA VIRUS INFECTION IN AUSTRALIAN BLACK FLYING FOXES (Pteropus ALECTO).
Journal of Wildlife Diseases, 2016Co-Authors: Lee Mcmichael, Daniel Edson, Joanne Meers, David G. Mayer, Alice Broos, Steven R. Kopp, Hume FieldAbstract:Abstract Bats of the genus Pteropus (Pteropodidae), colloquially known as flying foxes, are recognized as the natural reservoir of Hendra virus, a zoonotic paramyxovirus responsible for mortality in horses and humans. Some previous studies have suggested that physiologic and ecologic factors promote Hendra virus infection in flying foxes, and by extension, spillover to horses and humans. However, the impact of Hendra virus infection on relevant physiologic biomarkers in flying foxes has not been measured. Over 12 mo in eastern Australia, we captured and sampled 446 individual black flying foxes (Pteropus alecto), a putative primary reservoir host species, and measured a suite of hematologic, plasma biochemistry, and urinary biomarkers. All mean hematologic and biochemical values in both Hendra virus–positive and virus–negative cohorts were within the published reference ranges for black flying foxes. We found no association between Hendra virus infection (as indicated by PCR detection of Hendra virus RNA)...
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RESEARCH ARTICLE Haematology and Plasma Biochemistry of
2016Co-Authors: Wild Black Flying-foxes, Lee Mcmichael, Joanne Meers, Amanda Mclaughlin, David Mayer, Hume FieldAbstract:This paper establishes reference ranges for hematologic and plasma biochemistry values in wild Black flying-foxes (Pteropus alecto) captured in South East Queensland, Australia. Val-ues were found to be consistent with those of other Pteropus species. Four hundred and forty-seven animals were sampled over 12 months and significant differences were found be-tween age, sex, reproductive and body condition cohorts in the sample population. Mean val-ues for each cohort fell within the determined normal adult reference range, with the exception of elevated levels of alkaline phosphatase in juvenile animals. Hematologic and biochemistry parameters of injured animals showed little or no deviation from the normal ref-erence values for minor injuries, while two animals with more severe injury or abscessation showed leucocytosis, anaemia, thrombocytosis, hyperglobulinemia and hypoalbuminemia
Katharina Dittmar - One of the best experts on this subject based on the ideXlab platform.
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bartonella spp in fruit bats and blood feeding ectoparasites in madagascar
PLOS Neglected Tropical Diseases, 2015Co-Authors: Cara E Brook, Hafaliana C Ranaivoson, Andrew P Dobson, Michael Y Kosoy, Lynn M Osikowicz, Katharina DittmarAbstract:We captured, ectoparasite-combed, and blood-sampled cave-roosting Madagascan fruit bats (Eidolon dupreanum) and tree-roosting Madagascan flying foxes (Pteropus rufus) in four single-species roosts within a sympatric geographic foraging range for these species in central Madagascar. We describe infection with novel Bartonella spp. in sampled Eidolon dupreanum and associated bat flies (Cyclopodia dubia), which nest close to or within major known Bartonella lineages; simultaneously, we report the absence of Bartonella spp. in Thaumapsylla sp. fleas collected from these same bats. This represents the first documented finding of Bartonella infection in these species of bat and bat fly, as well as a new geographic record for Thaumapsylla sp. We further relate the absence of both Bartonella spp. and ectoparasites in sympatrically sampled Pteropus rufus, thus suggestive of a potential role for bat flies in Bartonella spp. transmission. These findings shed light on transmission ecology of bat-borne Bartonella spp., recently demonstrated as a potentially zoonotic pathogen.
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Lack of population genetic structure and host specificity in the bat fly, Cyclopodia horsfieldi, across species of Pteropus bats in Southeast Asia
Parasites & Vectors, 2013Co-Authors: Kevin J Olival, Katharina Dittmar, Nancy B. Simmons, Susan L. Perkins, Peter Daszak, Carl W Dick, Juan Carlos Morales, Don J Melnick, Rob DesalleAbstract:Background Population-level studies of parasites have the potential to elucidate patterns of host movement and cross-species interactions that are not evident from host genealogy alone. Bat flies are obligate and generally host-specific blood-feeding parasites of bats. Old-World flies in the family Nycteribiidae are entirely wingless and depend on their hosts for long-distance dispersal; their population genetics has been unstudied to date. Methods We collected a total of 125 bat flies from three Pteropus species ( Pteropus vampyrus, P. hypomelanus , and P. lylei ) from eight localities in Malaysia, Cambodia, and Vietnam. We identified specimens morphologically and then sequenced three mitochondrial DNA gene fragments (CoI, CoII, cytB; 1744 basepairs total) from a subset of 45 bat flies. We measured genetic diversity, molecular variance, and population genetic subdivision (F_ST), and used phylogenetic and haplotype network analyses to quantify parasite genetic structure across host species and localities. Results All flies were identified as Cyclopodia horsfieldi with the exception of two individuals of Eucampsipoda sundaica . Low levels of population genetic structure were detected between populations of Cyclopodia horsfieldi from across a wide geographic range (~1000 km), and tests for isolation by distance were rejected. AMOVA results support a lack of geographic and host-specific population structure, with molecular variance primarily partitioned within populations. Pairwise F_ST values from flies collected from island populations of Pteropus hypomelanus in East and West Peninsular Malaysia supported predictions based on previous studies of host genetic structure. Conclusions The lack of population genetic structure and morphological variation observed in Cyclopodia horsfieldi is most likely due to frequent contact between flying fox species and subsequent high levels of parasite gene flow. Specifically, we suggest that Pteropus vampyrus may facilitate movement of bat flies between the three Pteropus species in the region. We demonstrate the utility of parasite genetics as an additional layer of information to measure host movement and interspecific host contact. These approaches may have wide implications for understanding zoonotic, epizootic, and enzootic disease dynamics. Bat flies may play a role as vectors of disease in bats, and their competence as vectors of bacterial and/or viral pathogens is in need of further investigation.
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lack of population genetic structure and host specificity in the bat fly cyclopodia horsfieldi across species of Pteropus bats in southeast asia
Parasites & Vectors, 2013Co-Authors: Katharina Dittmar, Nancy B. Simmons, Kevin J Olival, Carl W Dick, Juan Carlos Morales, Don J MelnickAbstract:Population-level studies of parasites have the potential to elucidate patterns of host movement and cross-species interactions that are not evident from host genealogy alone. Bat flies are obligate and generally host-specific blood-feeding parasites of bats. Old-World flies in the family Nycteribiidae are entirely wingless and depend on their hosts for long-distance dispersal; their population genetics has been unstudied to date. We collected a total of 125 bat flies from three Pteropus species (Pteropus vampyrus, P. hypomelanus, and P. lylei) from eight localities in Malaysia, Cambodia, and Vietnam. We identified specimens morphologically and then sequenced three mitochondrial DNA gene fragments (CoI, CoII, cytB; 1744 basepairs total) from a subset of 45 bat flies. We measured genetic diversity, molecular variance, and population genetic subdivision (FST), and used phylogenetic and haplotype network analyses to quantify parasite genetic structure across host species and localities. All flies were identified as Cyclopodia horsfieldi with the exception of two individuals of Eucampsipoda sundaica. Low levels of population genetic structure were detected between populations of Cyclopodia horsfieldi from across a wide geographic range (~1000 km), and tests for isolation by distance were rejected. AMOVA results support a lack of geographic and host-specific population structure, with molecular variance primarily partitioned within populations. Pairwise FST values from flies collected from island populations of Pteropus hypomelanus in East and West Peninsular Malaysia supported predictions based on previous studies of host genetic structure. The lack of population genetic structure and morphological variation observed in Cyclopodia horsfieldi is most likely due to frequent contact between flying fox species and subsequent high levels of parasite gene flow. Specifically, we suggest that Pteropus vampyrus may facilitate movement of bat flies between the three Pteropus species in the region. We demonstrate the utility of parasite genetics as an additional layer of information to measure host movement and interspecific host contact. These approaches may have wide implications for understanding zoonotic, epizootic, and enzootic disease dynamics. Bat flies may play a role as vectors of disease in bats, and their competence as vectors of bacterial and/or viral pathogens is in need of further investigation.
Jonathan H. Epstein - One of the best experts on this subject based on the ideXlab platform.
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Duration of Maternal Antibodies against Canine Distemper Virus and Hendra Virus in Pteropid Bats
2016Co-Authors: Jonathan H. Epstein, Michelle L. Baker, Carlos Zambrana-torrelio, Jennifer Barr Edward A. Dubovi, Allyson Walsh, Katey Pelican, Mark D. Fielder, Angela J. Davies, Linfa WangAbstract:Old World frugivorous bats have been identified as natural hosts for emerging zoonotic viruses of significant public health concern, including henipaviruses (Nipah and Hendra virus), Ebola virus, and Marburg virus. Epidemiological studies of these viruses in bats often utilize serology to describe viral dynamics, with particular attention paid to juveniles, whose birth increases the overall susceptibility of the population to a viral outbreak once maternal immunity wanes. However, little is understood about bat immunology, including the duration of maternal antibodies in neonates. Understanding duration of maternally derived immunity is critical for characterizing viral dynamics in bat populations, which may help assess the risk of spillover to humans. We conducted two separate studies of pregnant Pteropus bat species and their offspring to measure the half-life and duration of antibodies to 1) canine distemper virus antigen in vaccinated captive Pteropus hypomelanus; and 2) Hendra virus in wild-caught, naturally infected Pteropus alecto. Both of these pteropid bat species are known reservoirs for henipaviruses. We found that in both species, antibodies were transferred from dam to pup. In P. hypomelanu
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roosting behaviour and habitat selection of Pteropus giganteus reveal potential links to nipah virus epidemiology
Journal of Applied Ecology, 2014Co-Authors: Micah B Hahn, Jonathan H. Epstein, Peter Daszak, Emily S Gurley, Mohammad Shahidul Islam, Stephen P Luby, Jonathan A PatzAbstract:Summary 1. Flying foxes Pteropus spp. play a key role in forest regeneration as seed dispersers and are also the reservoir of many viruses, including Nipah virus in Bangladesh. Little is known about their habitat requirements, particularly in South Asia. Identifying Pteropus habitat preferences could assist in understanding the risk of zoonotic disease transmission broadly and, in Bangladesh, could help explain the spatial distribution of human Nipah virus cases. 2. We analysed characteristics of Pteropus giganteus roosts and constructed an ecological niche model to identify suitable habitat in Bangladesh. We also assessed the distribution of suitable habitat in relation to the location of human Nipah virus cases. 3. Compared to non-roost trees, P. giganteus roost trees are taller with larger diameters and are more frequently canopy trees. Colony size was larger in densely forested regions and smaller in flood-affected areas. Roosts were located in areas with lower annual precipitation and higher human population density than non-roost sites. 4. We predicted that 2–17% of Bangladesh’s land area is suitable roosting habitat. Nipah virus outbreak villages were 26 times more likely to be located in areas predicted as highly suitable habitat for P. giganteus compared to non-outbreak villages. 5. Synthesis and applications. Habitat suitability modelling may help identify previously undocumented Nipah outbreak locations and improve our understanding of Nipah virus ecology by highlighting regions where there is suitable bat habitat but no reported human Nipah virus. Conservation and public health education is a key component of P. giganteus management in Bangladesh due to the general misunderstanding and fear of bats that are a reservoir of Nipah virus. Affiliation between Old World fruit bats (Pteropodidae) and people is common throughout their range, and in order to conserve these keystone bat species and prevent emergence of zoonotic viruses, it is imperative that we continue to improve our understanding of Pteropus resource requirements and routes of virus transmission from bats to people. Results presented here can be utilized to develop land management strategies and conservation policies that simultaneously protect fruit bats and public health.
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Henipavirus Infection in Fruit Bats (Pteropus giganteus), India
2013Co-Authors: Jonathan H. Epstein, Craig S Smith, Hume E. Field, Greer Meehan, Vibhu Prakash, Peter Daszak, A B. Mclaughlin, Andrew A. CunninghamAbstract:We tested 41 bats for antibodies against Nipah and Hendra viruses to determine whether henipaviruses circulate in pteropid fruit bats (Pteropus giganteus) in northern India. Twenty bats were seropositive for Nipah virus, which suggests circulation in this species, thereby extending the known distribution of henipaviruses in Asia westward by>1,000 km. Nipah virus (NiV) and Hendra virus (HeV) are zoonotic paramyxoviruses (genus Henipavirus) that have caused human deaths in Australia, Malaysia, Singapore, India, and Bangladesh (1–4). Known reservoirs for henipaviruses are Pteropus spp. fruit bats, which are distributed across the Indo-Pacific region from Madagascar eastward to the South Pacific islands (5). Evidence of henipavirus infection has been reported in Pteropus bats from Malaysia
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duration of maternal antibodies against canine distemper virus and hendra virus in pteropid bats
PLOS ONE, 2013Co-Authors: Michelle L. Baker, Victoria Boyd, Jennifer A Barr, Jonathan H. Epstein, Carlos Zambranatorrelio, Edward J Dubovi, Brian Pope, Shawn ToddAbstract:Old World frugivorous bats have been identified as natural hosts for emerging zoonotic viruses of significant public health concern, including henipaviruses (Nipah and Hendra virus), Ebola virus, and Marburg virus. Epidemiological studies of these viruses in bats often utilize serology to describe viral dynamics, with particular attention paid to juveniles, whose birth increases the overall susceptibility of the population to a viral outbreak once maternal immunity wanes. However, little is understood about bat immunology, including the duration of maternal antibodies in neonates. Understanding duration of maternally derived immunity is critical for characterizing viral dynamics in bat populations, which may help assess the risk of spillover to humans. We conducted two separate studies of pregnant Pteropus bat species and their offspring to measure the half-life and duration of antibodies to 1) canine distemper virus antigen in vaccinated captive Pteropus hypomelanus; and 2) Hendra virus in wild-caught, naturally infected Pteropus alecto. Both of these pteropid bat species are known reservoirs for henipaviruses. We found that in both species, antibodies were transferred from dam to pup. In P. hypomelanus pups, titers against CDV waned over a mean period of 228.6 days (95% CI: 185.4-271.8) and had a mean terminal phase half-life of 96.0 days (CI 95%: 30.7-299.7). In P. alecto pups, antibodies waned over 255.13 days (95% CI: 221.0-289.3) and had a mean terminal phase half-life of 52.24 days (CI 95%: 33.76-80.83). Each species showed a duration of transferred maternal immunity of between 7.5 and 8.5 months, which was longer than has been previously estimated. These data will allow for more accurate interpretation of age-related Henipavirus serological data collected from wild pteropid bats.
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characterization of nipah virus from naturally infected Pteropus vampyrus bats malaysia
Emerging Infectious Diseases, 2010Co-Authors: Sohayati Abdul Rahman, Kevin J Olival, Sharifah Syed Hassan, Maizan Mohamed, Liyen Chang, Latiffah Hassan, Norsharina M Saad, Syamsiah A Shohaimi, Zaini C Mamat, Jonathan H. EpsteinAbstract:We isolated and characterized Nipah virus (NiV) from Pteropus vampyrus bats, the putative reservoir for the 1998 outbreak in Malaysia, and provide evidence of viral recrudescence. This isolate is monophyletic with previous NiVs in combined analysis, and the nucleocapsid gene phylogeny suggests that similar strains of NiV are co-circulating in sympatric reservoir species.
Linfa Wang - One of the best experts on this subject based on the ideXlab platform.
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The Distribution of Henipaviruses in Southeast Asia and Australasia: Is Wallace’s Line a Barrier to Nipah Virus? PLoS One 2013
2016Co-Authors: Andrew C Breed, Joanne Meers, Jennifer A Barr, Linfa Wang, Katharine N. Bossart, Indrawati Sendow, Ina Smith, Supaporn Wacharapluesadee, Hume E. FieldAbstract:Nipah virus (NiV) (Genus Henipavirus) is a recently emerged zoonotic virus that causes severe disease in humans and has been found in bats of the genus Pteropus. Whilst NiV has not been detected in Australia, evidence for NiV-infection has been found in pteropid bats in some of Australia’s closest neighbours. The aim of this study was to determine the occurrence of henipaviruses in fruit bat (Family Pteropodidae) populations to the north of Australia. In particular we tested the hypothesis that Nipah virus is restricted to west of Wallace’s Line. Fruit bats from Australia, Papua New Guinea, East Timor and Indonesia were tested for the presence of antibodies to Hendra virus (HeV) and Nipah virus, and tested for the presence of HeV, NiV or henipavirus RNA by PCR. Evidence was found for the presence of Nipah virus in both Pteropus vampyrus and Rousettus amplexicaudatus populations from East Timor. Serology and PCR also suggested the presence of a henipavirus that was neither HeV nor NiV in Pteropus alecto and Acerodon celebensis. The results demonstrate the presence of NiV in the fruit bat populations on the eastern side of Wallace’s Line and within 500 km of Australia. They indicate the presence of non-NiV, non-HeV henipaviruses in fruit bat populations of Sulawesi and Sumba and possibly in Papua New Guinea. It appears that NiV is present where P. vampyrus occurs, such as in the fruit bat populations of Timor, but where this bat species is absent other henipaviruses may be present, as on Sulawesi and Sumba. Evidence was obtained for the presenc
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Duration of Maternal Antibodies against Canine Distemper Virus and Hendra Virus in Pteropid Bats
2016Co-Authors: Jonathan H. Epstein, Michelle L. Baker, Carlos Zambrana-torrelio, Jennifer Barr Edward A. Dubovi, Allyson Walsh, Katey Pelican, Mark D. Fielder, Angela J. Davies, Linfa WangAbstract:Old World frugivorous bats have been identified as natural hosts for emerging zoonotic viruses of significant public health concern, including henipaviruses (Nipah and Hendra virus), Ebola virus, and Marburg virus. Epidemiological studies of these viruses in bats often utilize serology to describe viral dynamics, with particular attention paid to juveniles, whose birth increases the overall susceptibility of the population to a viral outbreak once maternal immunity wanes. However, little is understood about bat immunology, including the duration of maternal antibodies in neonates. Understanding duration of maternally derived immunity is critical for characterizing viral dynamics in bat populations, which may help assess the risk of spillover to humans. We conducted two separate studies of pregnant Pteropus bat species and their offspring to measure the half-life and duration of antibodies to 1) canine distemper virus antigen in vaccinated captive Pteropus hypomelanus; and 2) Hendra virus in wild-caught, naturally infected Pteropus alecto. Both of these pteropid bat species are known reservoirs for henipaviruses. We found that in both species, antibodies were transferred from dam to pup. In P. hypomelanu
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Analysis of cathepsin and furin proteolytic enzymes involved in viral fusion protein activation in cells of the bat reservoir host.
PloS one, 2015Co-Authors: Farah El Najjar, Michelle L. Baker, Levi M Lampe, Linfa WangAbstract:Bats of different species play a major role in the emergence and transmission of highly pathogenic viruses including Ebola virus, SARS-like coronavirus and the henipaviruses. These viruses require proteolytic activation of surface envelope glycoproteins needed for entry, and cellular cathepsins have been shown to be involved in proteolysis of glycoproteins from these distinct virus families. Very little is currently known about the available proteases in bats. To determine whether the utilization of cathepsins by bat-borne viruses is related to the nature of proteases in their natural hosts, we examined proteolytic processing of several viral fusion proteins in cells derived from two fruit bat species, Pteropus alecto and Rousettus aegyptiacus. Our work shows that fruit bat cells have homologs of cathepsin and furin proteases capable of cleaving and activating both the cathepsin-dependent Hendra virus F and the furin-dependent parainfluenza virus 5 F proteins. Sequence analysis comparing Pteropus alecto furin and cathepsin L to proteases from other mammalian species showed a high degree of conservation; however significant amino acid variation occurs at the C-terminus of Pteropus alecto furin. Further analysis of furin-like proteases from fruit bats revealed that these proteases are catalytically active and resemble other mammalian furins in their response to a potent furin inhibitor. However, kinetic analysis suggests that differences may exist in the cellular localization of furin between different species. Collectively, these results indicate that the unusual role of cathepsin proteases in the life cycle of bat-borne viruses is not due to the lack of active furin-like proteases in these natural reservoir species; however, differences may exist between furin proteases present in fruit bats compared to furins in other mammalian species, and these differences may impact protease usage for viral glycoprotein processing.
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IRF7 in the Australian Black Flying Fox, Pteropus alecto - Table 1 : Evidence for a Unique Expression Pattern and Functional Conservation
2014Co-Authors: Peng Zhou, Christopher Cowled, Linfa Wang, Ashley Mansell, Paul Monaghan, Diane Green, Zhengli Shi, Michelle L. BakerAbstract:IRF7 in the Australian Black Flying Fox, Pteropus alecto - Table 1 : Evidence for a Unique Expression Pattern and Functional Conservation
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The Distribution of Henipaviruses in Southeast Asia and Australasia: Is Wallace's Line a Barrier to Nipah Virus?
PloS one, 2013Co-Authors: Andrew C Breed, Joanne Meers, Jennifer A Barr, Linfa Wang, Katharine N. Bossart, Indrawati Sendow, Ina Smith, Supaporn Wacharapluesadee, Hume FieldAbstract:Nipah virus (NiV) (Genus Henipavirus) is a recently emerged zoonotic virus that causes severe disease in humans and has been found in bats of the genus Pteropus. Whilst NiV has not been detected in Australia, evidence for NiV-infection has been found in pteropid bats in some of Australia's closest neighbours. The aim of this study was to determine the occurrence of henipaviruses in fruit bat (Family Pteropodidae) populations to the north of Australia. In particular we tested the hypothesis that Nipah virus is restricted to west of Wallace's Line. Fruit bats from Australia, Papua New Guinea, East Timor and Indonesia were tested for the presence of antibodies to Hendra virus (HeV) and Nipah virus, and tested for the presence of HeV, NiV or henipavirus RNA by PCR. Evidence was found for the presence of Nipah virus in both Pteropus vampyrus and Rousettus amplexicaudatus populations from East Timor. Serology and PCR also suggested the presence of a henipavirus that was neither HeV nor NiV in Pteropus alecto and Acerodon celebensis. The results demonstrate the presence of NiV in the fruit bat populations on the eastern side of Wallace's Line and within 500 km of Australia. They indicate the presence of non-NiV, non-HeV henipaviruses in fruit bat populations of Sulawesi and Sumba and possibly in Papua New Guinea. It appears that NiV is present where P. vampyrus occurs, such as in the fruit bat populations of Timor, but where this bat species is absent other henipaviruses may be present, as on Sulawesi and Sumba. Evidence was obtained for the presence henipaviruses in the non-Pteropid species R. amplexicaudatus and in A. celebensis. The findings of this work fill some gaps in knowledge in geographical and species distribution of henipaviruses in Australasia which will contribute to planning of risk management and surveillance activities.
