Search

Background: The dengue, Zika, and Chikungunya arboviruses have spread in America in the past year, thus becoming global health issues. These viruses are maintained in nature in two transmission cycles: an urban cycle, transmitted from hematophagous mosquitoes to humans, and a wild cycle, recorded only in Africa and Asia, involving mosquitoes and nonhuman primates as natural hosts. The evidence shows that these arboviruses infect other wild mammals in America, such as rodents, marsupials, and bats. This study aimed to determine the potential natural infection of arboviruses in bats captured in contrasting sites (tropical forests, urban areas, and caves) in Oaxaca, Mexico. Materials and Methods: Liver samples were collected from some bats and tested for RNA from dengue, Zika, and Chikungunya with the quantitative real-time PCR assay. We analyzed 162 samples that encompassed 23 bat species. Results: No natural infection with any of the three arboviruses was detected in any sample tested. Conclusion: The existence of a wild cycle of the three arboviruses in the American continent is not ruled out. However, owing to the low or zero prevalence recorded in other studies and the present study, bats are likely involved in the arbovirus transmission cycle as accidental hosts. [ABSTRACT FROM AUTHOR]

Alopecia, or alopecia syndrome is the partial or complete loss of hair from an animal's body. Following a previous report on bats with alopecia, in this work we complemented the list of bat species with alopecia available in the literature through 2023, adding phyllostomids (Artibeus planirostris, Carollia perspicillata), an emballonurid (Peropteryx pallidoptera), molossids (Molossus rufus, Nyctinomops macrotis), and vespertilionids (Corynorhinus rafinesquii, Eptesicus fuscus, Nycticeius humeralis, Myotis austroriparius, M. grisescens, M. velifer). We also explored factors that may explain alopecia in the first records of this condition in ten Pteronotus mesoamericanus females from Oaxaca, southeastern Mexico, recorded from November 2020 to January 2022. In those individuals, hair loss was observed on the back and head; six of them were lactating and four showed no evidence of reproductive activity. In addition, we documented alopecia on the thorax in four individuals of three species: Artibeus lituratus (one pregnant female and one male with scrotal testes), Pteronotus fulvus (one pregnant female), and Artibeus toltecus (one pregnant female). The alopecic bats presented mild alopecia (the affected area ranged from 1–5 cm2), and only one female showed moderate alopecia (8.1 cm2). Alopecia in P. mesoamericanus, P. fulvus, A. toltecus, and A. lituratus may be due to hormonal or nutritional imbalances associated with reproduction. In addition, in A. lituratus it may also be the result of environmental stress when foraging in an urban area. The causal agents of alopecia in bats are still not fully known, and it is probably a multifactorial phenomenon. La alopecia, o síndrome de alopecia es la pérdida parcial o total del pelo del cuerpo de un animal. Siguiendo un informe previo sobre murciélagos con alopecia, en este trabajo complementamos la lista de especies de murciélagos con alopecia disponibles en la literatura hasta 2023, agregando filostómidos (Artibeus planirostris, Carollia perspicillata), un embalonúrido (Peropteryx pallidoptera), molósidos (Molossus rufus, Nyctinomops macrotis) y vespertiliónidos (Corynorhinus rafinesquii, Eptesicus fuscus, Nycticeius humeralis, Myotis austroriparius, M. grisescens, M. velifer). También exploramos los factores que pueden explicar la alopecia en los primeros registros de esta condición en diez hembras de Pteronotus mesoamericanus de Oaxaca, sureste de México, registradas desde noviembre de 2020 hasta enero de 2022. En esos individuos se observó pérdida de pelo en el dorso y la cabeza; seis de ellos estaban lactando y cuatro no mostraron evidencia de actividad reproductiva. Además, documentamos alopecia en el tórax en cuatro individuos de tres especies: Artibeus lituratus (una hembra gestante y un macho con testículos escrotados), Pteronotus fulvus (una hembra gestante) y Artibeus toltecus (una hembra gestante). Los murciélagos alopécicos presentaron alopecia leve (el área afectada osciló entre 1–5 cm2), y solo una hembra presentó alopecia moderada (8.1 cm2). La alopecia en P. mesoamericanus, P. fulvus, A. toltecus y A. lituratus puede deberse a desequilibrios hormonales o nutricionales asociados con la reproducción. Además, en A. lituratus también puede ser el resultado del estrés ambiental cuando se alimenta en un área urbana. Los agentes causales de la alopecia en murciélagos aún no se conocen por completo, y probablemente se trate de un fenómeno multifactorial. [ABSTRACT FROM AUTHOR]

The movement of individuals between roosts allows gene flow and influences the spatial distribution, dynamics, and genetic structure of populations. The objectives of this study were to describe the patterns of movement of the bats Mormoops megalophylla, Pteronotus fulvus, and Pteronotus mesoamericanus, between a mine (La Mina) and two caves (El Apanguito and Cerro Huatulco) and explore some drivers for the movements in Oaxaca, México using capture-recapture methods. From July 2016 to June 2017, we captured 5082 individuals (2369 P. fulvus, 1868 P. mesoamericanus, and 845 M. megalophylla). We obtained 292 recaptures, including 57 recaptures represented inter-roost movements (34 by P. fulvus, 18 by P. mesoamericanus, and 5 by M. megalophylla). Brownie's Multistate model showed that the movements among roosts were species-specific and were determined only by the roost occupied before capture for P. mesoamericanus, by the roosts used before and after capture for P. fulvus, or only by seasonality for M. megalophylla. The results showed that the reproductive condition could have influenced the movements between roosts in the three mormoopids, mainly due to the formation of maternity colonies of P. mesoamericanus and P. fulvus in the El Apanguito cave and exclusive colonies of M. megalophylla males in Cerro Huatulco. Due to the importance of the reproductive events that occur in the roosts studied, we suggest that the three roosts should be considered as part of the group of Important Sites for the Conservation of Bats in the state of Oaxaca. [ABSTRACT FROM AUTHOR]

Dengue fever, caused by the dengue virus (DENV), is one of the most important reemerging viral diseases transmitted by arthropods worldwide. DENV is maintained in nature in two transmission cycles: urban and sylvatic. The latter has only been recorded in Africa and Asia and involves nonhuman primates as natural hosts, although it has been suggested that other mammals may play a secondary role as potential reservoir host, including bats. The objective of this article is to review the current state of knowledge about DENV-positive bats in the Americas and to determine what ecological and human impact variables could favor DENV infection in bats. We performed a search of published studies on natural and experimental DENV infection in bats. From 1952 to 2019, 14 studies have been carried out (71.4% in the last decade) examining DENV infection in bats in seven countries of the Americas. DENV infection was examined in 1884 bats of 63 species and DENV was detected in 19 of these species. Clench's model estimated that more than 75 species could be carriers of DENV; therefore, considering that at least 350 species of bats are distributed in the Americas, to detect 95% of the DENV-bearing species, it would be necessary to examine about 10,206 bats of ∼287 species that have not been analyzed until 2019. The species with the highest number of positive cases were Molossus sinaloae and Artibeus jamaicensis. Species, colony size, mean annual temperature, mean annual precipitation, human population size, and bat collection site (site inhabited by humans, vegetation cover, and caves) contributed to explain the variation in DENV detection in bats in the Americas. These results provide evidence on the exposure of bats to DENV in different geographic areas of the Americas and a bat sylvatic transmission cycle is very likely to be occurring, where bats may be either accidental hosts, dead-end hosts, or potential reservoir hosts for DENV. [ABSTRACT FROM AUTHOR]

Introduction: Group or colony size is an important variable that is related to biological, ecological, and conservation aspects of bats. However, estimating the size of each colony or group in roosts used by more than one species is particularly difficult, especially when recapture rates are very low (< 10 %). Objective: Estimate the colony size of 14 species of bats: one emballonurid, one natalid, four mormoopids, seven phyllostomids, and one vespertilionid, which roosted throughout one year (July 2016 to June 2017) in a mine and two caves -Cerro Huatulco and El Apanguito- in the Sierra Sur and Costa of the state of Oaxaca. Methods: We constructed capture-recapture histories per species and roost, and for species for which we obtained recaptures that represented at least 10 % of the captures, we used the probabilistic Cormack-Jolly-Seber model. In the case of species with no recaptures or with a recapture proportion lower than 10 %, we estimated the number of individuals per roost by applying the same proportion between the number of captured specimens and the estimated number for species with recaptures greater than 10 % and that they belonged to the same family or trophic guild. Results: The total estimated number of bats in the three studied roosts was 20 105. The highest colony size estimates were for the mormoopids Pteronotus fulvus and P. mesoamericanus from El Apanguito and P. fulvus from Cerro Huatulco, with 6609, 4092 and 2 212 individuals, respectively. Conclusions: The methodology used in this study allowed estimating the colony size for all registered species, even though only for 21.42 % the recapture rates were greater than 10 %. Therefore, we consider that this methodology represents a viable alternative to estimate colony size in other roosts. This information, together with the high species richness and importance for reproductive processes, allow us to propose these sites as Bat Protection and Conservation Areas in Mexico. [ABSTRACT FROM AUTHOR]

Pigmentation abnormalities in fur or wings membranes have been reported in >100 bat species worldwide. In the case of the Mormoopidae family, abnormalities have been documented in Pteronotus mesoamericanus, Pteronotus quadridens, and Mormoops megalophylla. This work represents the first record of Pteronotus fulvus with a coloration pattern different from the one commonly reported in their entire range. [ABSTRACT FROM AUTHOR]

Introduction: Reproduction is a critical phase for most living organisms and in bats the reproductive strategies exhibit considerable complexity and variability. Objective: To describe the reproductive patterns and population dynamics of seven bat species (Artibeus toltecus, Carollia perspicillata, Glossophaga soricina, Mormoops megalophylla, Pteronotus fulvus, Pteronotus mesoamericanus and Natalus mexicanus) that roost in one mine (La Mina) and two caves (El Apanguito and Cerro Huatulco) in the State of Oaxaca, in Southeastern México. Methods: Sampling was conducted monthly from July 2016 to June 2017. Bats were captured using a harp trap, which was placed at the entrance of the roosts. The captured bats were identified using taxonomic keys, marked with an aluminum ring, sex and age class were also determined. Reproductive activity was modeled through 63 GLMs for each species (504 in total). The best model was selected according to the Akaike Information Criterion (AIC). Results: A total of 5 836 bats were captured and marked, classified into 14 species, 10 genera, and five families. The most abundant species were: P. fulvus and P. mesoamericanus, representing 41 % and 32.3 % of the captures, respectively. The mormopids M. megalophylla, P. fulvus, P. mesoamericanus, together with N. mexicanus showed a restricted seasonal monoestrous pattern, while the phyllostomids A. toltecus, C. perspicillata, and G. soricina showed a seasonal bimodal polyoestry pattern. The monthly abundance of species fluctuated significantly (H= 13, df= 11, P= 0.044) in the three roosts throughout the entire study period and the best supported GLM that included the seven species showed that the six chosen variables (season, sex, roost, temperature, precipitation and humidity) were positively associated with reproductive activity. Conclusions: The reproductive activity of each species seems to be synchronized with the end of the dry season and the beginning of the rainy season, as well as influenced by factors such as temperature, humidity and roost site. [ABSTRACT FROM AUTHOR]

The SARS-CoV-2 coronavirus is the focus of attention as it has caused more than three million human deaths globally. This and other coronaviruses, such as MERS-CoV, have been suggested to be related to coronaviruses that are hosted in bats. This work shows, through a bibliographic review, the frequency of detection of coronavirus in bats species of the Americas. The presence of coronavirus in bats has been examined in 25 investigations in 11 countries of the Americas between 2007 and 2020. Coronaviruses have been explored in 9371 individuals from 160 species of bats, and 187 coronavirus sequences have been deposited in GenBank distributed in 43 species of bats. While 91% of the coronaviruses sequences identified infect a single species of bat, the remainder show a change of host, dominating the intragenera change. So far, only Mex-CoV-6 is related to MERS-CoV, a coronavirus pathogenic for humans, so further coronavirus research effort in yet unexplored bat species is warranted. [ABSTRACT FROM AUTHOR]