RESUMO
Flavivirus (family Flaviviridae) and Alphavirus (family Togaviridae) are mosquito-borne viruses that poses a significant risk to public health worldwide. Examples of these viruses include Dengue virus (DENV) and Zika virus (ZIKV) in the Flavivirus genus, and Chikungunya virus (CHIKV) in the Alphavirus genus. The potential contribution of bats in the mosquito-to-human transmission cycle of these viral genera in the tropics has not been studied. Here, a total of 144 bats belonging to three families (Emballonuridae, Phyllostomidae, and Molossidae) and six species were captured for one year using mist nets in sites with different landscapes (forest and grassland) in the state of Yucatan, southeastern Mexico. Blood samples and rectal and oral swabs were collected to detect Flavivirus and Alphavirus RNA genomes through RT-PCR. Flavivirus RNA was detected in 53 individuals (36.8%; 95% CI: 29.4%-44.9%), and Alphavirus RNA was detected in 59 individuals (40.1%; 95% CI: 33.2%-49.2%). The sequences obtained were consistent with ZIKV and DENV, into the Flavivirus, and CHIKV into the Alphavirus positive samples. The prevalence of both Flavivirus and Alphavirus was higher during the dry season compared with the rainy season. This high positivity rate, highlighted in both Flavivirus and Alphavirus, suggests a potential contribution of bats in the circulation of these viral genera in sylvatic environments. Seasonal variation in viral genera prevalence, with higher prevalence during dry seasons than rainy seasons, may suggest specific viral activity patterns in response to climatic conditions.
RESUMO
An inventory of parasites infecting the jaguar (Panthera onca) across its distribution range is relevant for the conservation of this threatened big cat. In this study, we report the occurrence of helminths in a jaguar from Mexico using morphological techniques (cleared and stained mounts and scanning electron microscopy) and partial sequences of the 28S ribosomal RNA (28S rRNA) gene and the cytochrome c oxidase 1 mitochondrial (COI) gene. We also provide an updated list of helminth species reported in jaguars in the Americas. Three helminth taxa are identified in the jaguar examined from Mexico: Toxocara cati, Physaloptera sp., and Taenia sp. The new 28S rRNA sequences of To. cati, Physaloptera sp., and Taenia sp. and the COI sequence of Taenia sp. corroborate the identity of the helminths isolated from this host. One hundred and twenty-nine records of helminths parasitizing jaguars from 49 studies up to May 2023 were identified in the Americas. In most of these studies (73.6%), helminths were identified using coproparasitological techniques. Sixteen helminths (7 nematodes, 5 cestodes, 3 acanthocephalans, and 1 trematode) were identified at the species level in free-ranging and captive jaguars. The study demonstrates the value of an integrative taxonomy approach to increase the accuracy of parasite identification in wildlife, especially when helminth specimens are scarce or poorly fixed.
Assuntos
Helmintos , Nematoides , Panthera , Animais , Panthera/genética , México/epidemiologia , RNA Ribossômico 28S/genética , Helmintos/genéticaRESUMO
To date, 23 species of trematodes have been reported in bats from Mexico. However, in some regions of Mexico, such as the Yucatan Peninsula, many species of bats do not have helminthological records. Here, we sampled bats in four localities in Southeastern Mexico from April 2017 to February 2022. Parasites were collected from the intestine of four species of bats: Pteronotus fulvus, Eumops nanus, Noctilio leporinus and Nyctinomops laticaudatus. Conventional morphological techniques and molecular tools with the 28S ribosomal gene were used to describe the helminths. We discovered that our parasites represent three new species and a new combination of trematodes. We found that the new species have morphological differences with their congeneric species, and we complement this information whit molecular data. Furthermore, we found morphological and molecular evidence that places Dicrocoelium rileyi within the genus Brachylecithum. This study points out the importance of comparing morphological and phylogenetic information.
Assuntos
Quirópteros , Dicrocoeliidae , Parasitos , Trematódeos , Animais , México , Filogenia , Especificidade da EspécieRESUMO
Helminth species of Neotropical bats are poorly known. In Mexico, few studies have been conducted on helminths of bats, especially in regions such as the Yucatan Peninsula where Chiroptera is the mammalian order with the greatest number of species. In this study, we characterized morphologically and molecularly the helminth species of bats and explored their infection levels and parasitehost interactions in the Yucatan Peninsula, Mexico. One hundred and sixty-three bats (representing 21 species) were captured between 2017 and 2022 in 15 sites throughout the Yucatan Peninsula. Conventional morphological techniques and molecular tools were used with the 28S gene to identify the collected helminths. Hostparasite network analyses were carried out to explore interactions by focusing on the level of host species. Helminths were found in 44 (26.9%) bats of 12 species. Twenty helminth taxa were recorded (7 trematodes, 3 cestodes and 10 nematodes), including 4 new host records for the Americas. Prevalence and mean intensity of infection values ranged from 7.1 to 100% and from 1 to 56, respectively. Molecular analyses confirmed the identity of some helminths at species and genus levels; however, some sequences did not correspond to any of the species available on GenBank. The parasitehost network suggests that most of the helminths recorded in bats were host-specific. The highest helminth richness was found in insectivorous bats. This study increases our knowledge of helminths parasitizing Neotropical bats, adding new records and nucleotide sequences.
Assuntos
Quirópteros , Helmintíase Animal , Helmintos , Nematoides , Parasitos , Animais , Quirópteros/parasitologia , México/epidemiologia , Helmintos/genética , Interações Hospedeiro-Parasita , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologiaRESUMO
In this survey, we inventoried the helminths of heteromyid and cricetid rodents captured in the Yucatan Peninsula from 2017 to 2019. Helminths were identified using morphological techniques (clearing, staining, and scanning electron microscopy). Also, the 28S rRNA gene of individuals from several helminth taxa was successfully amplified and sequenced. To confirm the identification at the generic level, and in some cases at the specific level, and the genealogical relationships of the parasites, phylogenetic analyses were performed with the new 28S sequences. We identified 22 species of helminths including three trematodes (Brachylaimidae, Dicrocoeliidae, and Microphallidae), five cestodes (Davaineidae, Hymenolepididae, and Taeniidae), and 14 nematodes (Trichuridae, Ancylostomatidae, Ornithostrongylidae, Heligmonellidae, and Oxyuridae) from Heteromys gaumeri (Heteromyidae), Ototylomys phyllotis, Oligoryzomys fulvescens, Peromyscus yucatanicus, Sigmodon toltecus, and Reithrodontomys gracilis (Cricetidae). The overall frequency of infection in small rodents was 84.1% (143/170); all specimens of H. gaumeri, S. toltecus and Ol. fulvescens were infected with helminths. In total, we provided 46 new sequences of the 28S gene from 17 species of helminths. Seven species are likely undescribed species, six are reported for the first time in rodents from Mexico, and 12 are new host records in the Americas. Before this study, 87 taxa of helminths had been reported from 35 cricetid and 12 heteromyid species in 21 Mexican states. Our findings increase to 93 the helminth taxa in these rodents, and to 36 the cricetid species parasitized by helminths. This large scale-survey is the first to use an integrative approach to inventory the helminths of wild small rodents in Mexico.