Lleida Bat Lyssavirus isolation in Miniopterus schreibersii in France

Bat rabies cases are attributed in Europe to five different Lyssavirus species of 16 recognized Lyssavirus species causing rabies. One of the most genetically divergent Lyssavirus spp. has been detected in a dead Miniopterus schreibersii bat in France. Brain samples were found positive for the presence of antigen, infectious virus and viral RNA by classical virological methods and molecular methods respectively. The complete genome sequence was determined by next‐generation sequencing. The analysis of the complete genome sequence confirmed the presence of Lleida bat lyssavirus (LLEBV) in bats in France with 99.7% of nucleotide identity with the Spanish LLEBV strain (KY006983).     

Detection of specific antibody responses to vaccination in variable flying foxes (Pteropus hypomelanus)

Megachiropteran bats are biologically important both as endangered species and reservoirs for emerging human pathogens. Reliable detection of antibodies to specific pathogens in bats is thus epidemiologically critical. Eight variable flying foxes (Pteropus hypomelanus) were immunized with 2,4-dinitrophenylated bovine serum albumin (DNP-BSA). Each bat received monthly inoculations for 2 months. Affinity-purified IgG was used for production of polyclonal and monoclonal anti-variable flying fox IgG antibodies. ELISA and western blot analysis were used to monitor immune responses and for assessment of polyclonal and monoclonal antibody species cross-reactivity. Protein G, polyclonal antibodies, and monoclonal antibodies detected specific anti-DNP antibody responses in immunized variable flying foxes, with protein G being the most sensitive, followed by monoclonal antibodies and then polyclonal antibodies. While the polyclonal antibody was found to cross-react well against IgG of all bat species tested, some non-specific background was observed. The monoclonal antibody was found to cross-react well against IgG of six other species in the genus Pteropus and to cross-react less strongly against IgG from Eidolon helvum or Phyllostomus hastatus. Protein G distinguished best between vaccinated and unvaccinated bats, and these results validate the use of protein G for detection of bat IgG. Monoclonal antibodies developed in this study recognized immunoglobulins from other members of the genus Pteropus well, and may be useful in applications where specific detection of Pteropus IgG is needed.     

Serological evidence of widespread exposure of Grenada fruit bats to chikungunya virus

Antibody detection against selected potentially zoonotic vector‐borne alphaviruses and flaviviruses was conducted on sera from bats from all six parishes in Grenada, West Indies. Sera were tested for (i) antibodies to flaviviruses West Nile virus, St. Louis encephalitis virus, Ilhéus virus, Bussuquara virus (BSQV), Rio Bravo virus and all four serotypes of dengue virus (DENV) by plaque reduction neutralization test (PRNT); (ii) antibodies to alphaviruses western equine encephalitis virus, Venezuelan equine encephalitis virus and eastern equine encephalitis virus by epitope‐blocking enzyme‐linked immunosorbent assay (ELISA); and (iii) antibodies to the alphavirus chikungunya (CHIKV) by PRNT. Two species of fruit bats were sampled, Artibeus jamaicensis and Artibeus lituratus, all roosting in or within 1,000 m of human settlements. Fifteen (36%) of the 42 bats tested for neutralizing antibodies to CHIKV were positive. The CHIKV‐seropositive bats lived in localities spanning five of the six parishes. All 43 bats tested for epitope‐blocking ELISA antibody to the other alphaviruses were negative, except one positive for Venezuelan equine encephalitis virus. All 50 bats tested for neutralizing antibody to flaviviruses were negative, except one that had a BSQV PRNT₈₀ titre of 20. The CHIKV serology results indicate that bats living close to and within human settlements were exposed to CHIKV in multiple locations. Importantly, bats for this study were trapped a year after the introduction and peak of the human CHIKV epidemic in Grenada. Thus, our data indicate that bats were exposed to CHIKV possibly during a time of marked decline in human cases.     

Epizootology and experimental infection of Yokose virus in bats

To reveal whether bats serve as an amplifying host for Yokose virus (YOKV), we conducted a serological survey and experimentally infected fruit bats with YOKV isolated from microbats in Japan. YOKV belongs to the Entebbe bat virus group of vector unknown group within the genus Flavivirus and family Flaviviridae. To detect antibodies against YOKV, we developed an enzyme-linked immunosorbent assay (ELISA) using biotinylated anti-bat IgG rabbit sera. Serological surveillance was conducted with samples collected in the Philippines and the sera supplied from Malaysia. One of the 36 samples from the Philippines (2.7%) and 5 of the 26 samples from Malaysia (19%) had detectable ELISA antibodies. In the experimental infections, no clinical signs of disease were observed. Moreover, no significant viral genome amplification was detected. These findings revealed that YOKV replicates poorly in the fruit bat, suggesting that fruit bats do not seem to serve as an amplifying host for YOKV.     

Seroepidemiology of Selected Alphaviruses and Flaviviruses in Bats in Trinidad

A serosurvey of antibodies against selected flaviviruses and alphaviruses in 384 bats (representing 10 genera and 14 species) was conducted in the Caribbean island of Trinidad. Sera were analysed using epitope‐blocking enzyme‐linked immunosorbent assays (ELISAs) specific for antibodies against West Nile virus (WNV), Venezuelan equine encephalitis virus (VEEV) and eastern equine encephalitis virus (EEEV), all of which are zoonotic viruses of public health significance in the region. Overall, the ELISAs resulted in the detection of VEEV‐specific antibodies in 11 (2.9%) of 384 bats. Antibodies to WNV and EEEV were not detected in any sera. Of the 384 sera, 308 were also screened using hemagglutination inhibition assay (HIA) for antibodies to the aforementioned viruses as well as St. Louis encephalitis virus (SLEV; which also causes epidemic disease in humans), Rio Bravo virus (RBV), Tamana bat virus (TABV) and western equine encephalitis virus (WEEV). Using this approach, antibodies to TABV and RBV were detected in 47 (15.3%) and 3 (1.0%) bats, respectively. HIA results also suggest the presence of antibodies to an undetermined flavivirus(es) in 8 (2.6%) bats. Seropositivity for TABV was significantly (P < 0.05; χ²) associated with bat species, location and feeding preference, and for VEEV with roost type and location. Differences in prevalence rates between urban and rural locations were statistically significant (P < 0.05; χ²) for TABV only. None of the aforementioned factors was significantly associated with RBV seropositivity rates.     

Orthohepadnavirus infection in a neotropical bat (Platyrrhinus lineatus)

Hepatitis B virus (HBV) is the prototype of the Orthohepadnavirus genus and represents an important cause of chronic hepatitis, liver cirrhosis, and hepatic cancer in humans worldwide. To verify the occurrence and genetic variability of orthohepadnavirus among neotropical bats, we tested 81 liver samples of New World bats from São Paulo State, Southeastern Brazil, collected during 2012. PCR, sequencing, and phylogenetic analysis of Surface/Polymerase and Core viral genes confirmed the occurrence of the first isolate of bat orthohepadnavirus detected in South America. These results may contribute to subsequent studies of the origin, variability, host species, and evolution of bat orthohepadnaviruses in South America.     

Preliminary serological characterization of bovine viral diarrhoea virus strains using monoclonal antibodies

Five monoclonal antibodies against the bovine viral diarrhoea (BVD) viral strain NADL were isolated and characterized by an indirect immunofluorescence assay. Extensive cross-reactions were detected when the antibodies were tested with 12 heterologous BVD and four hog cholera (HC) viral strains. One antibody reacted with all strains tested. Two antibodies were specific for cytopathogenic BVD viruses, but failed to react with HC virus. The other antibodies reacted to varying degrees with BVD and HC viral strains.     

Prevalence of bovine viral diarrhea virus infection in bulls in artificial insemination centers in Poland

This study was directed at the evaluation of the prevalence of bovine viral diarrhea virus (BVDV) infection in bulls in artificial insemination centers. Both serological and virological examinations were performed. Blood samples were tested in micro-seroneutralization test for BVDV antibodies. Virus isolation was performed in cell culture and BVDV antigen was detected in an indirect immunofluorescence assay with monoclonal antibodies. One hundred and seventy-five serum samples and 219 whole blood samples for virus isolation were tested. Neutralizing antibodies were found in 86% of the bulls. Persistent infection (PI) was detected in 0.9% of the analyzed blood samples.     

Neotropical primary bat cell lines show restricted dengue virus replication

Dengue is the most widespread arboviral disease affecting humans. Bats are recognized carriers of emerging viral zoonoses and have been proposed as dengue reservoirs, since RNA/NS1 and/or antiviral antibodies have been detected. Yet, experimental inoculation of Artibeus bats failed to show virus replication. This conflicting results prevent drawing further conclusions of whether bats sustain dengue infection. To test bat cellular permissivity to dengue infection, we established primary bat embryonic cells from diverse organs and tissues of Artibeus jamaicensis, Molossus sinaloae, and Desmodus rotundus. We observed a limited serotype-, organ-, and bat species- specific dengue susceptibility. Only some Molossus-derived primary cells sustained poorly initial Dengue serotype-1 replication, though it was latter absent. To elucidate if Molossus bats may play a role in dengue replication, ecological or in vivo experiments must be performed. Taken together our results show that Dengue did not replicate efficiently in cell lines derived from Neotropical bat species.     

Evidence of Australian bat lyssavirus infection in diverse Australian bat taxa

Historically, Australia was considered free of rabies and rabieslike viruses. Thus, the identification of Australian bat lyssavirus (ABLV) in 1996 in a debilitated bat found by a member of the public precipitated both public health consternation and a revision of lyssavirus taxonomy. Subsequent observational studies sought to elaborate the occurrence and frequency of ABLV infection in Australian bats. This paper describes the taxonomic diversity of bat species showing evidence of ABLV infection to better inform public health considerations. Blood and/or brain samples were collected from two cohorts of bats (wild‐caught and diagnostic submissions) from four Australian states or territories between April 1996 and October 2002. Fresh brain impression smears were tested for ABLV antigen using fluorescein‐labelled anti‐rabies monoclonal globulin (CENTOCOR) in a direct fluorescent antibody test; sera were tested for the presence of neutralising antibodies using a rapid fluorescent focus inhibition test. A total of 3,217 samples from 2,633 bats were collected and screened: brain samples from 1,461 wild‐caught bats and 1,086 submitted bats from at least 16 genera and seven families, and blood samples from 656 wild‐caught bats and 14 submitted bats from 14 genera and seven families. Evidence of ABLV infection was found in five of the six families of bats occurring in Australia, and in three of the four Australian states/territories surveyed, supporting the historic presence of the virus in Australia. While the infection prevalence in the wild‐caught cohort is evidently low, the significantly higher infection prevalence in rescued bats in urban settings represents a clear and present public health significance because of the higher risk of human exposure.     

Genetic analysis of European bat lyssavirus type 1 isolates from France

European bat lyssavirus type 1a (EBLV-1a) was first identified in central France from a serotine bat (Eptesicus serotinus) collected at the end of 2002. Rabies was diagnosed by reference rabies diagnosis methods and molecular tools. Phylogenetic analysis of 14 viral isolates obtained from French bats infected with EBLV-1 between 1989 and the end of 2002 against 47 nucleoprotein sequences showed a north-west to east distribution of EBLV-1a virus and a south to north distribution of EBLV-1b virus, isolates of which could be divided into two groups: group 1 in north-eastern France and group 2 in central and north-western France.     

Could bats act as reservoir hosts for Rift Valley fever virus?

The inter-epizootic reservoir host of Rift Valley fever virus (RVFV) remains unknown, although the namaqua rock rat, Aethomys namaquensis, as well as bats have been implicated. Bats can be asymptomatically infected with rabies, as well as several arboviruses; the possibility that they can act as host for RVFV therefore exists. To examine this possibility, 350 different samples (brain, liver, salivary glands and brown fat) obtained from 150 bats (comprising seven species) were tested for RVFV antigen using an enzyme linked immunosorbent assay (ELISA). None of the samples tested positive, but the ELISA proved to have limited sensitivity (> or = 10(3) TCID50/ml). In order to determine whether bats could be infected with RVFV, one Miniopterus schreibersii and two Eptesicus capensis bats were inoculated by the oral or intramuscular route with 100 ml and 30 ml, respectively, of a RVFV suspension with a titre of 10(6) TCID50/ml. None of the bats developed any clinical signs. A low concentration of RVFV antigen was found in the liver and urine of M. schreibersii, but not in brain tissue. A third E. capensis bat was inoculated by the intramuscular route and sacrificed on day 18. A low level of antigen was detected in the brown fat. These results demonstrate that bats can be infected with RVFV, and that further studies should be done to determine the potential of different bat species to act as reservoir hosts for RVFV during inter-epizootic periods.     

An outbreak of vampire bat-transmitted rabies in cattle in northeastern Mexico.

An outbreak of bovine rabies occurred on a ranch when cattle were bitten by vampire bats. Microscopic lesions showed a nonsuppurative encephalitis with intracytoplasmic inclusion bodies. Immunohistochemistry demonstrated viral antigen in the brain, and monoclonal antibodies identified a serotype 1 (vampire strain) of the rabies virus.     

Understanding Ebola virus and other zoonotic transmission risks through human–bat contacts: Exploratory study on knowledge,attitudes and practices in Southern Cameroon

The ecology of Ebola virus (EBV) remains largely unknown, but the previous detection of viral RNA and anti‐EBV antibodies in African bats suggests that they might play a role in the EBV reservoir. Moreover, African bats also carry other potentially zoonotic agents such as Henipah‐like viruses, coronaviruses and lyssaviruses. Today only little information is available on interactions between humans and bats. The objective of our exploratory study was to describe the extent and modes of contacts between humans and bats in southern Cameroon, considered as an area at risk for future EBV outbreaks. The survey was conducted in 11 villages of four distinct rural areas in southern Cameroon. A total of 135 respondents were interviewed using semi‐structured questionnaires, between February and May 2017. The study showed that direct contacts between bats and humans are relatively common. Bat bushmeat appeared to be an occasional meat resource; 40% of respondents consume bats with a median annual consumption of three, and 28% of respondents hunt them. About 22% of the respondents reported children catching bats. Indirect contact also appeared to be common; 55% of hunters use caves as shelters and 67% of interviewees eat fruits previously chewed by bats. Bat consumption varied significantly between regions (from 0% to 87%) and between pygmies and bantus in the extreme south‐east of Cameroon. The study revealed considerable diversity in practices among interviewees, most of them being subsistence cultivators and relying on self‐hunted bushmeat. Geographical diversity of contacts and perceptions regarding bats in Cameroon emphasizes the need to adjust zoonotic pathogen surveillance and education campaigns to the specificities of the communities and their context of interaction with wildlife.     

Comparative analysis of monoclonal antibodies against pestiviruses: report of an international workshop

Thirty-three pestivirus strains were grown in cell culture and characterized by immunostaining with 19 monoclonal antibodies (MAbs) raised against hog cholera virus (HCV), with 42 MAbs against bovine viral diarrhoea virus (BVDV) and with 13 MAbs against border disease virus (BDV). Seven MAbs reacted with all pestivirus strains tested, eight MAbs detected only the seven HCV strains, three detected only the 16 BVDV strains. No MAb was found that was specific for BDV. BVDV and BDV strains were broadly cross-reactive with the MAbs, indicating a close relationship between these two species, whereas HCV strains were characterized as distinct from BVDV and BDV.     

Detection of the Severe Acute Respiratory Syndrome‐Related Coronavirus and Alphacoronavirus in the Bat Population of Taiwan

Bats have been demonstrated to be natural reservoirs of severe acute respiratory syndrome coronavirus (SARS CoV) and Middle East respiratory syndrome (MERS) CoV. Faecal samples from 248 individuals of 20 bat species were tested for partial RNA‐dependent RNA polymerase gene of CoV and 57 faecal samples from eight bat species were tested positive. The highest detection rate of 44% for Scotophilus kuhlii, followed by 30% for Rhinolophus monoceros. Significantly higher detection rates of coronaviral RNA were found in female bats and Scotophilus kuhlii roosting in palm trees. Phylogenetic analysis classified the positive samples into SARS‐related (SARSr) CoV, Scotophilus bat CoV 512 close to those from China and Philippines, and Miniopterus bat CoV 1A‐related lineages. Coronaviral RNA was also detected in bat guano from Scotophilus kuhlii and Myotis formosus flavus on the ground and had potential risk for human exposure. Diverse bat CoV with zoonotic potential could be introduced by migratory bats and maintained in the endemic bat population in Taiwan.     

Molecular detection of bat coronaviruses in three bat species in Indonesia

Bats are an important reservoir of several zoonotic diseases. However, the circulation of bat coronaviruses (BatCoV) in live animal markets in Indonesia has not been reported. Genetic characterization of BatCoV was performed by sequencing partial RdRp genes. Real-time polymerase chain reaction based on nucleocapsid protein (N) gene and Enzyme-linked immunosorbent assay against the N protein were conducted to detect the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA and antibody, respectively. We identified the presence of BatCoV on Cynopterus brachyotis, Macroglossus minimus, and Rousettus amplexicaudatus. The results showed that the BatCoV included in this study are from an unclassified coronavirus group. Notably, SARS-CoV-2 viral RNA and antibodies were not detected in the sampled bats.     

蝙蝠作为流行性乙型脑炎病毒宿主的研究

1986、1988、1990和1997年的7－8月，在云南省共捕获653只蝙蝠，其中棕果蝠（Rousettus leschenaulti)593只，金管鼻蝠（Murina aurata)60只，采集血清及剖取脑组织作病毒分离和抗体检查。用细胞法和乳鼠法分离到6株病毒，带毒率为0．96％，其中从捕自景洪的棕果蝠脑组织中分离到3株，从河口的棕果蝠血清中分离到2株，从捕自耿马的金管鼻蝠脑组织中分离出1株。棕果蝠和金管鼻蝠的带毒率分别为0．84％和1．67％。这6株病毒能引起C6／36和BHK21细胞病变和导致乳小白鼠或3－4周龄小白鼠发病和死亡，并具有典型的嗜神经病毒感染症状，经血凝抑制，补体结合，免疫荧光和中和试验鉴定。新分离的6株病毒均为乙脑病毒（JE virus)。同期用血凝抑制试验对采获的425份棕果蝠血清作乙脑病毒抗体检查。阳性153－份，阳性率为36％，人有较高的感染率，。本次从棕果蝠和金管鼻蝠体内分离出乙脑病毒属具有重要流行病学意义。     

The detection of transmissible gastroenteritis viral antibodies by immunodiffusion.

Precipitating antibodies against transmissible gastroenteritis viral antigens were detected by the immunodiffusion test in two transmissible gastroenteritis viral hyperimmune antisera and in antiserum prepared against haemagglutinating encephalomyelitis virus but not in sera from several species of normal animals, in antisera prepared against a variety of othet viruses and bacteria or sera from swine with bacterial enteritis. When the immunodiffusion test was compared with the virus neutralization test for the detection of transmissible gastroeneritis viral antibodies in 20 swine sera certain samples which contained high titres of virus neutralizing antibodies failed to produce precipitation while other sera were positive in the immunodiffusion test although their virus neutralizing antibody titres were relatively low. Precipitating antibodies were also detected by immunodiffusion in several samples of milk whey from a sow which had been vaccinated with inactivated transmissible gastroenteritis virus.