RESUMEN

BACKGROUND: Arthropod-borne flaviviruses like dengue virus (DENV) and yellow fever virus (YFV) are major human pathogens. In Latin America, YFV is maintained in sylvatic cycles involving non-human primates (NHP) and forest-dwelling mosquitos. YFV supposedly does not circulate north of Panama. METHODS: We conducted a serologic study for flaviviruses and other emerging viruses in NHP from southeastern Mexico. A total of thirty sera of black-handed spider monkeys (Ateles geoffroyi, n = 25), black howler monkeys (Alouatta pigra, n = 3), and mantled howler monkeys (Al. palliata, n = 2) sampled in 2012 and 2018 were screened by an indirect immunofluorescence assay (IFA) to detected IgG antibodies against DENV, YFV, Zika virus (ZIKV), West Nile virus (WNV), Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus, Middle East respiratory syndrome coronavirus, and Zaire Ebola virus, and confirmed by plaque reduction neutralization tests (PRNT90) representing all mosquito-borne flavivirus serocomplexes circulating in the Americas. RESULTS: A total of 16 sera (53.3%; 95% CI, 34.3-71.7) showed IFA reactivity to at least one tested flavivirus with end-point titers ranging from 1:100 to 1:1000. No serum reacted with other viruses. Monotypic and high mean PRNT90 endpoint YFV titers of 1:246 were found in 3 black-handed spider monkey sera (10.0%; 95% CI, 2.1-26.5) sampled in 2018 in Tabasco, compared to all other flaviviruses tested. Monotypic endpoint PRNT90 titers of 1:28 for Ilheus virus and 1:22 for WNV in serum of black howler monkeys sampled in 2018 in Tabasco suggested additional flavivirus exposure. CONCLUSIONS: Our findings may suggest unnoticed YFV circulation. Intensification of YFV surveillance in NHP and vectors is warranted in Mexico and potentially other areas considered free of yellow fever.

RESUMEN

Bats are important natural reservoir hosts of a diverse range of viruses that can be transmitted to humans and have been suggested to play an important role in the Zika virus (ZIKV) transmission cycle. However, the exact role of these animals as reservoirs for flaviviruses is still controversial. To further expand our understanding of the role of bats in the ZIKV transmission cycle in Latin America, we carried out an experimental infection in wild-caught Artibeus lituratus bats and sampled several free-living neotropical bats across three countries of the region. Experimental ZIKV infection was performed in wild-caught adult bats (4 females and 5 males). The most relevant findings were hemorrhages in the bladder, stomach and patagium. Significant histological findings included inflammatory infiltrate consisting of a predominance of neutrophils and lymphocytes, in addition to degeneration in the reproductive tract of males and females. This suggests that bat reproduction might be at some level affected by ZIKV. Leukopenia was also observed in some inoculated animals. Hemorrhages, genital alterations, and leukopenia are suggested to be caused by ZIKV; however, since these were wild-caught bats, we cannot exclude other agents. Detection of ZIKV by qPCR was observed at low concentrations in only two urine samples in two inoculated animals. All other animals and tissues tested were negative. Finally, no virus-neutralizing antibodies were found in any animal. To determine ZIKV infection in nature, the blood of a total of 2056 bats was sampled for ZIKV detection by qPCR. Most of the sampled individuals belonged to the genus Pteronotus sp. (23%), followed by the species Carollia sp. (17%), Anoura sp. (14%), and Molossus sp. (13.7%). No sample of any tested species was positive for ZIKV by qPCR. These results together suggest that bats are not efficient amplifiers or reservoirs of ZIKV and may not have an important role in ZIKV transmission dynamics.

Asunto(s)

RESUMEN

Rodents and bats are the most diverse mammal group that host Bartonella species. In the Americas, they were described as harboring Bartonella species; however, they were mostly characterized to the genotypic level. We describe here Bartonella isolates obtained from blood samples of one rodent (Peromyscus yucatanicus from San José Pibtuch, Yucatan) and two bat species (Desmodus rotundus from Progreso, and Pteronotus parnellii from Chamela-Cuitzmala) from Mexico. We sequenced and described the genomic features of three Bartonella strains and performed phylogenomic and pangenome analyses to decipher their phylogenetic relationships. The mouse-associated genome was closely related to Bartonella vinsonii. The two bat-associated genomes clustered into a single distinct clade in between lineages 3 and 4, suggesting to be an ancestor of the rodent-associated Bartonella clade (lineage 4). These three genomes showed <95% OrthoANI values compared to any other Bartonella genome, and therefore should be considered as novel species. In addition, our analyses suggest that the B. vinsonii complex should be revised, and all B. vinsonii subspecies need to be renamed and considered as full species. The phylogenomic clustering of the bat-associated Bartonella strains and their virulence factor profile (lack of the Vbh/TraG conjugation system remains of the T4SS) suggest that it should be considered as a new lineage clade (L5) within the Bartonella genus.

RESUMEN

Introduction: Field work with bats is an important contribution to many areas of research in environmental biology and ecology, as well as microbiology. Work with bats poses hazards such as bites and scratches, and the potential for exposure to infectious pathogens such as rabies virus. It also exposes researchers to many other potential hazards inherent to field work, such as environmental conditions, delayed emergency responses, or challenging work conditions. Methods: This article discusses the considerations for a thorough risk assessment process around field work with bats, pre- and post-occupational health considerations, and delves into specific considerations for areas related to biosafety concerns-training, personal protective equipment, safety consideration in field methods, decontamination, and waste. It also touches on related legal and ethical issues that sit outside the realm of biosafety, but which must be addressed during the planning process. Discussion: Although the focal point of this article is bat field work located in northern and central America, the principles and practices discussed here are applicable to bat work elsewhere, as well as to field work with other animal species, and should promote careful considerations of how to safely conduct field work to protect both researchers and animals.

RESUMEN

In pre-Hispanic Mexico, dogs were not identified as an important source of rabies. We know from codexes and chronicles of the conquerors that at that time, rabies cases in humans and domestic animals were caused by local wildlife species such as bats. Canine-rabies virus variant seems to have arrived with Europeans. The first documented case of canine rabies in the Americas is found in Mexico in the Annals of the Holy Inquisition (16th century). During Mexico's independence, cases were frequently reported. In the 19th century the first attempts to control human rabies were made through sanitary measures such as elimination of rabid dogs and applying postexposure vaccination. During the first half of the 20th century, the efficacy of canine vaccination to prevent human rabies was established. However, in Mexico, despite reports of numerous human cases (>70/year), canine vaccination did not have enough coverage. It was only during the 1990s that Mexico made a serious commitment to eliminate dog-transmitted human rabies. Since the beginning, vaccination campaigns have been free and massive. Coverage increased from 7,100,000 doses in 1990 to more than 18,000,000 since 2017. This culminated in the elimination of dog-mediated human rabies cases since 2006. Subsequently, the epidemiology of rabies had changed. Nowadays, it is wildlife species (mainly bats and skunks) that are the source of human rabies. As a mega-biodiverse country Mexico has numerous wildlife species with potential to transmit rabies virus. Thus it is paramount to remain vigilant with respect to canine vaccination campaigns and to promote rabies research in wildlife.

Asunto(s)

RESUMEN

In 2019, the World Health Organization (WHO) and the Pan-American Health Organization (PAHO) recognized Mexico as a country free of human rabies transmitted by dogs. Nevertheless, the sylvatic cycle remains as a public health concern in the country. Although cougars (Puma concolor) are not reservoirs of any rabies virus variant (RVV), these felines could act as vectors at the top of the food chain, and their relationships with other organisms must be considered important for the regulatory effect on their prey's populations. In this study, genetic and antigenic characterization was performed on all cougar rabies cases diagnosed at the Rabies Laboratory Network of the Ministry of Health (RLNMH) in Mexico from 2000 to 2021. Samples from other species, a skunk, a horse (Equus caballus) (attacked by a cougar), and a gray fox (Urocyon cineroargenteus), were included as reference. Rabies cases in cougars were restricted to two Northern states of Mexico (Sonora and Chihuahua). Five out of six samples of cougars were RVV7 (Arizona gray fox RVV) and one from Sonora was RVV1. Interestingly, there is no evidence of RVV1 in dogs in the Northern states since the 1990s but skunk species now harbor this RVV1 in this region of the country.

RESUMEN

In humans, co-infection of hepatitis B and C viruses (HBV, HCV) is common and aggravates disease outcome. Infection-mediated disease aggravation is poorly understood, partly due to lack of suitable animal models. Carnivores are understudied for hepatitis virus homologues. We investigated Mexican carnivores (ringtails, Bassariscus astutus) for HBV and HCV homologues. Three out of eight animals were infected with a divergent HBV termed ringtail HBV (RtHBV) at high viral loads of 5 × 109 -1.4 × 1010 copies/ml serum. Two of the RtHBV-infected animals were co-infected with a divergent hepacivirus termed ringtail hepacivirus (RtHV) at 4 × 106 -7.5 × 107 copies/ml in strain-specific qRT-PCR assays. Immunofluorescence assays relying on HBV core and RtHV NS3/4a proteins indicated that none of the animals had detectable hepadnavirus core-specific antibodies, whereas one RtHV-infected animal had concomitant RtHV-specific antibodies at 1:800 end-point titre. RtHBV and RtHV complete genomes showed typical HBV and HCV structure and length. All RtHBV genomes were identical, whereas RtHV genomes showed four amino acid substitutions located predominantly in the E1/E2-encoding genomic regions. Both RtHBV (>28% genomic nucleotide sequence distance) and RtHV (>30% partial NS3/NS5B amino acid sequence distance) formed new species within their virus families. Evolutionary analyses showed that RtHBV grouped with HBV homologues from different laurasiatherian hosts (carnivores, bats, and ungulates), whereas RtHV grouped predominantly with rodent-borne viruses. Ancestral state reconstructions showed that RtHV, but not RtHBV, likely emerged via a non-recent host switch involving rodent-borne hepacivirus ancestors. Conserved hepatitis virus infection patterns in naturally infected ringtails indicate that carnivores may be promising animal models to understand HBV/HCV co-infection.

Asunto(s)

RESUMEN

Canine Distemper Virus (CDV) can produce a fatal multisystem disease in carnivores and other mammals and is an important threat for wildlife conservation. However, integrative and comparative studies in wild carnivores are scarce and some areas of the world lack of genetic studies. We explore the dynamic of host-CDV in a procyonid community during an outbreak. This study reports for the first time an index case occurred in a common raccoon (Procyon lotor) and for which a complete CDV diagnosis was performed. The long-term epidemiological analysis in two sympatric populations of common raccoons and white-nosed coatis (Nasua narica) was achieved through seroneutralization, RT-PCR and direct immunofluorescence assays. Additionally, hematologic analyses were performed and phylogenetic reconstruction of CDV was done using molecular data from this study. Overall prevalence for white-nosed coatis was 19.6 % and for common raccoons was 25.3 % by seroneutralization, and 13.3 % and 17.3 % by RT-PCR. Antibodies titer average for white-nosed coatis was 1:512 and 1:156 for common raccoons. Significant difference in prevalence between white-nosed coatis and common raccoons was detected during one season (summer 2013). White-nosed coatis showed differences in erythrocytes and monocytes counts between positives and negative animals. A 100 % similarity was found between CDV of white-nosed coati and CDV of common raccoon and is a new CDV sequence not previously described; this sequence is close to Asian and European lineage. An endemic state of distemper in both species was observed but showed different dynamics over time per host species. Differences in cellular and humoral responses were also detected between procyonids. The evidence found here may have serious implications for CDV understanding in wild carnivores, it reveals clear differences in the response over time to the same CDV strain, in two close related carnivore species.

Asunto(s)

RESUMEN

Coatis (Nasua narica) and raccoons (Procyon lotor) potentially play an important role in zoonotic diseases because they may carry pathogens and can transmit them to humans. To date, our understanding of the immune function of these two carnivores is deficient. The aim of this study was to compare the number of leucocyte subtypes and the phagocytic capacity between the coati and the raccoon. Blood samples were collected, and leucocyte subtypes were characterized and counted by flow cytometry and microscopy, respectively. Phagocytosis was analysed by kinetic assay. Differences in leucocytes between these two species were found; the total count of neutrophils was higher in raccoons than in coatis, but lymphocytes and eosinophils were higher in coatis than in raccoons. Antigen reduction was more rapid for the coatis. However, raccoons had a higher efficient endocytic process than coatis. This study provides the basis for understanding the procyonid immune system, which informs conservation, particularly since some procyonids are imperilled.

RESUMEN

INTRODUCTION: The biological test established by the World Health Organization to isolate and amplify the rabies virus consists in inoculating lactating mice by intracranial route and detecting rabies signs for 21 days. OBJECTIVE: To verify viral transmission in mothers of rabies virus-inoculated lactating mice. METHOD: Twenty-seven Mexican rabies virus isolates were inoculated by intracranial route in lactating mice, which were observed for 21 days. The mothers were observed for 60 days. The diagnosis was established by immunofluorescence in brain tissue. The virus was characterized by sequencing and with monoclonal antibodies. RESULTS: All litters showed rabies at between 7 and 15 days post-inoculation (p. i.). Three of the 27 females (11 %) had developed rabies at days 33, 37 and 39 p. i. of their litters. Viral characterization showed that the mothers were infected with the same variant of their offspring, two of them stemming from hematophagous bat and one from dog. The liters that transmitted rabies to their mothers were nine individuals. CONCLUSIONS: In nature, the rabies virus could be preserved by transmission from neonates (more susceptible to contracting and amplifying the rabies virus) to their mothers.

INTRODUCCIÓN: La prueba biológica establecida por la Organización Mundial de la Salud para aislar y amplificar el virus de la rabia consiste en inocular vía intracraneal ratones lactantes para detectar signos de rabia en un periodo de 21 días. OBJETIVO: Constatar el contagio viral en las madres de ratones lactantes inoculados con virus de la rabia. MÉTODO: Veintisiete aislados mexicanos de virus de la rabia se inocularon vía intracraneal en ratones lactantes, los cuales fueron observados por 21 días y sus madres, por 60 días. El diagnóstico se llevó a cabo mediante inmunofluorescencia en cerebro. El virus se caracterizó por secuenciación y anticuerpos monoclonales. RESULTADOS: Todas las camadas presentaron rabia entre siete y 15 días posinoculación (p. i.); tres de las 27 hembras (11 %), a los días 33, 37 y 39 p. i. de sus crías. La caracterización viral mostró que las madres se infectaron con la misma variante de sus crías, dos procedían de murciélago hematófago y una de perro. Las camadas que trasmitieron rabia a sus madres fueron nueve individuos. CONCLUSIONES: En la naturaleza, el virus de la rabia podría preservarse mediante la transmisión de los neonatos (más susceptibles de contraer y amplificar el virus) a sus madres.

Asunto(s)

RESUMEN

Animal microbiomes play an important role in dietary adaptation, yet the extent to which microbiome changes exhibit parallel evolution is unclear. Of particular interest is an adaptation to extreme diets, such as blood, which poses special challenges in its content of proteins and lack of essential nutrients. In this study, we assessed taxonomic signatures (by 16S rRNA amplicon profiling) and potential functional signatures (inferred by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt)) of haematophagy in birds and bats. Our goal was to test three alternative hypotheses: no convergence of microbiomes, convergence in taxonomy and convergence in function. We find a statistically significant effect of haematophagy in terms of microbial taxonomic convergence across the blood-feeding bats and birds, although this effect is small compared to the differences found between haematophagous and non-haematophagous species within the two host clades. We also find some evidence of convergence at the predicted functional level, although it is possible that the lack of metagenomic data and the poor representation of microbial lineages adapted to haematophagy in genome databases limit the power of this approach. The results provide a paradigm for exploring convergent microbiome evolution replicated with independent contrasts in different host lineages. This article is part of the theme issue 'Convergent evolution in the genomics era: new insights and directions'.

Asunto(s)

RESUMEN

Resumen Introducción: La prueba biológica establecida por la Organización Mundial de la Salud para aislar y amplificar el virus de la rabia consiste en inocular vía intracraneal ratones lactantes para detectar signos de rabia en un periodo de 21 días. Objetivo: Constatar el contagio viral en las madres de ratones lactantes inoculados con virus de la rabia. Método: Veintisiete aislados mexicanos de virus de la rabia se inocularon vía intracraneal en ratones lactantes, los cuales fueron observados por 21 días y sus madres, por 60 días. El diagnóstico se llevó a cabo mediante inmunofluorescencia en cerebro. El virus se caracterizó por secuenciación y anticuerpos monoclonales. Resultados: Todas las camadas presentaron rabia entre siete y 15 días posinoculación (p. i.); tres de las 27 hembras (11 %), a los días 33, 37 y 39 p. i. de sus crías. La caracterización viral mostró que las madres se infectaron con la misma variante de sus crías, dos procedían de murciélago hematófago y una de perro. Las camadas que trasmitieron rabia a sus madres fueron nueve individuos. Conclusiones: En la naturaleza, el virus de la rabia podría preservarse mediante la transmisión de los neonatos (más susceptibles de contraer y amplificar el virus) a sus madres.

Abstract Introduction: The biological test established by the World Health Organization to isolate and amplify the rabies virus consists in inoculating lactating mice by intracranial route and detecting rabies signs for 21 days. Objective: To verify viral transmission in mothers of rabies virus-inoculated lactating mice. Method: Twenty-seven Mexican rabies virus isolates were inoculated by intracranial route in lactating mice, which were observed for 21 days. The mothers were observed for 60 days. The diagnosis was established by immunofluorescence in brain tissue. The virus was characterized by sequencing and with monoclonal antibodies. Results: All litters showed rabies at between 7 and 15 days post-inoculation (p. i.). Three of the 27 females (11 %) had developed rabies at days 33, 37 and 39 p. i. of their litters. Viral characterization showed that the mothers were infected with the same variant of their offspring, two of them stemming from hematophagous bat and one from dog. The liters that transmitted rabies to their mothers were nine individuals. Conclusions: In nature, the rabies virus could be preserved by transmission from neonates (more susceptible to contracting and amplifying the rabies virus) to their mothers.

Asunto(s)

RESUMEN

Bats can host pathogenic organisms such as viruses and fungi, but little is known about the pathogenicity of their parasites. Hemoparasites are frequently recorded in Neotropical bats, particularly Litomosoides (Filarioidea: Onchocercidae), but their pathogenic effect on bats is scarcely known. In this work, Litomosoides microfilariae were identified in four (8%) out of 51 sampled frugivorous bats belonging to three different species: Artibeus aztecus, Artibeus jamaicensis, and Artibeus lituratus, which are located in Yautepec, Morelos, Mexico. Two infected animals showed weakness, tachypnoea, and ecchymosis on their wings. In these animals, histopathology revealed microfilariae in the blood vessels of the lung, liver, and spleen. Both animals presented exudative pneumonia with congestion and concomitant edema, in addition to moderate arterial hypertrophy. Parasitemia was quantified in blood samples of the infected animals (>3000 parasites/mL). Phylogenetic analysis placed the obtained sequence inside the Litomosoides genus, reaching over 98% identity to the related species. Due to the relevance of bats in ecosystems, any new record of their parasite repertoire offers noteworthy insights into our understanding of the ecology and impact of new parasite species in bats.

RESUMEN

Bartonella spp. have been identified in many bat species worldwide, including the zoonotic species, Candidatus Bartonella mayotimonensis. The common vampire bat (Desmodus rotundus) preys preferentially on livestock in Latin America and is frequently infected with Bartonella spp. To determine the potential role of D. rotundus in transmitting Bartonella to livestock, common vampire bats and bat-bitten domestic ruminants from Mexico were tested for Bartonella infection by blood culture or conventional PCR. Furthermore, to explore the possibility of bite transmission during blood feeding, saliva swabs from 35 D. rotundus known to be either Bartonella bacteremic (N = 17) or blood culture negative (N = 18) were tested by PCR to detect the presence of Bartonella DNA. Twenty (17.1%) of 117 sheep and 16 (34.8%) of 46 cattle were Bartonella bacteremic by PCR testing. However, none of them were infected with Bartonella strains previously isolated from vampire bats and none of the 35 D. rotundus saliva swabs tested were PCR positive for Bartonella. All but two animals among those which were Bartonella culture and/or PCR positive, were infected with either B. bovis (cattle) or B. melophagi (sheep). Two sheep were infected by a possible new species, Candidatus Bartonella ovis, being phylogenetically closer to B. bovis than B. melophagi. This study does not support the role of D. rotundus as a reservoir of Bartonella species infecting livestock, which could be transmitted via bite and blood feeding and therefore suggest limited risk of zoonotic transmission of Bartonella from common vampire bats to humans.

Asunto(s)

RESUMEN

Bartonellae are emerging blood-borne bacteria that have been recovered from a wide range of mammalian species and arthropod vectors around the world. Bats are now recognized as a potential wildlife reservoir for a diverse number of Bartonella species, including the zoonotic Candidatus B. mayotimonensis. These bat-borne Bartonella species have also been detected in the obligate ectoparasites of bats, such as blood-feeding flies, which could transmit these bacteria within bat populations. To better understand this potential for transmission, we investigated the relatedness between Bartonella detected or isolated from bat hosts sampled in Mexico and their ectoparasites. Bartonella spp. were identified in bat flies collected on two bat species, with the highest prevalence in Trichobius parasiticus and Strebla wiedemanni collected from common vampire bats (Desmodus rotundus). When comparing Bartonella sequences from a fragment of the citrate synthase gene (gltA), vector-associated strains were diverse and generally close to, but distinct from, those recovered from their bacteremic bat hosts in Mexico. Complete Bartonella sequence concordance was observed in only one bat-vector pair. The diversity of Bartonella strains in bat flies reflects the frequent host switch by bat flies, as they usually do not live permanently on their bat host. It may also suggest a possible endosymbiotic relationship with these vectors for some of the Bartonella species carried by bat flies, whereas others could have a mammalian host.

Asunto(s)

RESUMEN

Rabies DNA vaccines based on full-length glycoprotein (G) induce virus neutralizing antibody (VNA) responses and protect against the virus challenge. Although conformational epitopes of G are the main target of VNAs, some studies have shown that a polypeptide linear epitope G5 is also able to induce VNAs. However, a G5 DNA vaccine has not been explored. While multiple doses of DNA vaccines are required in order to confer a protective immune response, this could be overcome by the inclusion of C3d-P28, a molecular adjuvant is know to improve the antibody response in several anti-viral vaccine models. To induce and enhance the immune response against rabies in mice, we evaluated two DNA vaccines based on the linear epitope G5 of Rabies Virus (RABV) glycoprotein (pVaxG5 vaccine) and another vaccine consisting of G5 fused to the molecular adjuvant C3d-P28 (pVaxF1 vaccine). VNA responses were measured in mice immunized with both vaccines. The VNA levels from the group immunized with pVaxG5 decreased gradually, while those from the group vaccinated with pVaxF1 remained high throughout the experimental study. After challenge with 22 LD50 of the Challenge Virus Strain (CVS), the survival rate of mice immunized with pVaxG5 and pVaxF1 was increased by 27% and 50% respectively, in comparison to the PBS group. Furthermore, the in vitro proliferation of anti-rabies specific spleen CD4+ and CD8+ T cells from mice immunized with pVaxF1 was observed. Collectively, these results suggest that the linear G5 epitope is a potential candidate vaccine. Furthermore, the addition of a C3d-P28 adjuvant contributed to enhanced protection, the sustained production of VNAs, and a specific T-cell proliferative response.

Asunto(s)

RESUMEN

A redescription, with a discussion of new features and illustrations, for all life stages is presented for the parasitic mite Periglischrus herrerai Machado-Allison associated with the common vampire bat Desmodus rotundus (Geoffoy), including a description of the heteromorphic female and the first description of its female deutonymph. In addition, the morphological variation of P. herrerai is evaluated by morphometric analysis of the adults, concluding that there is an evident geographic variation throughout the neotropics. This study was possible by using type material of P. herrerai from the Machado-Allison collection, and voucher specimens from other collections, and specimens from an extensive surveying of hematophagous bats in some localities of the Pacific and Atlantic versants, and central Mexico.

Asunto(s)

RESUMEN

Blood-feeding arthropods play a major role in the transmission of several flaviviruses, which represent an important problem for human health. Currently, dengue is one of the most important arboviral emerging diseases worldwide. Furthermore, some previous studies have reported the presence of viral nucleic acids and antibodies against dengue virus (DENV) in wild animals. Our knowledge of the role played by wildlife reservoirs in the sylvatic transmission and maintenance of DENV remains limited. Our objective was to screen blood-feeding ectoparasites (bat flies) and their common vampire bat (Desmodus rotundus) hosts, for flaviviruses in Hidalgo, Mexico. We detected Flavivirus sequences in 38 pools of ectoparasites (Diptera: Streblidae, Strebla wiedemanni and Trichobius parasiticus) and 8 tissue samples of D. rotundus by RT-PCR and semi-nested PCR using FlaviPF1S, FlaviPR2bis, and FlaviPF3S primers specific for NS5, a gene highly conserved among flaviviruses. Phylogenetic inference analysis performed using the maximum likelihood algorithm implemented in PhyML showed that six sequences clustered with DENV (bootstrap value = 53.5%). Although this study supports other reports of DENV detection in bats and arthropods other than Aedes mosquitoes, the role of these ectoparasitic flies and of hematophagous bats in the epidemiology of DENV still warrants further investigation.

Asunto(s)

RESUMEN

Ecological, immunological, and epidemiological factors enable bats to transmit an increasingly recognized spectrum of zoonotic agents, and bartonellae are among those emerging pathogens identified in bats and their arthropod ectoparasites. Current data reveal a multifaceted disease ecology where diverse host species distributed around the world interact with a number of Bartonella spp. and several potential vectors. This review summarizes the methods and findings of studies conducted since 2005 to illustrate that Bartonella bacteremia varies by bat species, location, and other potential variables, such as diet with a very high prevalence in hematophagous bats. Among bat families, Bartonella prevalence ranged from 7.3% among Nycteridae to 54.4% in Miniopteridae. Further research can build on these current data to better determine risk factors associated with Bartonella infection in bat populations and the role of their ectoparasites in transmission.

Asunto(s)

RESUMEN

Experimental infection of Artibeus intermedius, the great fruit-eating bat, was performed with vampire bat rabies isolates. Bats (n=35) were captured in the wild and quarantined prior to experimental infection. No rabies antibodies were detected by rapid fluorescent focus inhibition test (RFFIT) prior to infection. Three doses of rabies virus (RV) and three different routes of infection were used. One out of 35 bats died without showing any clinical signs at day 14 and was positive for rabies. None of the 34 other bats showed clinical signs for rabies, but high antibody titers were detected post-inoculation, suggesting either innate immune response to the vampire bat rabies virus or possible pre-exposure to RV and inoculation leading to a booster effect. Rabies virus was detected by hemi-nested RT-PCR (hnRT-PCR) in the brain (n=3), stomach (n=1) of bats that were negative by immunofluorescence and that survived rabies infection. The bat that died on day 14 was positive by hnRT-PCR on the brain, heart and liver. These results suggest that either previous non-lethal exposure to RV or natural low susceptibility to vampire bat viruses somehow protected Artibeus intermedius from clinical rabies infection leading to a marginal lethality effect on this bats species population in the wild.

Asunto(s)