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

This study aims to describe the natural Leptospira occurrence in small mammals from Yucatan, Mexico, and to explore the relation between the characteristics of the capture sites and the Leptospira occurrence. Bats and rodents were captured in five sites of Yucatan state, and from them, a kidney fragment was collected that was used in the genomic DNA extraction. Leptospira DNA was identified by PCR targeting the 16S-rRNA and LipL32 genes. Additionally, a bioinformatic analysis was carried out to know the Leptospira species and was corroborated with a phylogenetic tree. The assemblage of small mammals was compound of 82 (51.2 %) bats and 78 (48.8 %) rodents. A global frequency (bats plus rodents) of Leptospira occurrence of 21.2 % (34/160) was observed; in bats, it was 21.9 % (18/82), and in rodents, 20.5 % (16/78). The phylogenetic trees based on LipL32 gene showed that the recovered sequences most closely resemble the species L. borgpetersenii and L. noguchii. The ordination of the capture sites with tropical deciduous forests as original vegetation is more related to the abundance of Leptospira-infected rodents. The ordination of the capture sites with tropical sub-deciduous forests as original vegetation is more related to the diversity of Leptospira-infected bat species. The canonical ordering of the capture sites is by the original vegetation type and the diversity and abundance of Leptospira-infected bat and rodent species.

Assuntos

Quirópteros , Leptospira , Leptospirose , Animais , Leptospira/genética , Leptospirose/epidemiologia , Leptospirose/veterinária , México/epidemiologia , Roedores , Filogenia , DNA Bacteriano/genética

RESUMO

Rickettsia parkeri belongs to the spotted fever group (SFG) of the Rickettsia genus. This bacterium causes mild rickettsiosis in humans and is mainly transmitted by Amblyomma ticks. Its medical importance is emerging in the Americas, including Mexico. Synanthropic rodents and domiciled dogs participate as accidental hosts in epidemiological cycles of Rickettsia of the SFG. The aim is to report the presence of R. parkeri in synanthropic rodents and domiciled dogs from a rural community of Yucatán, Mexico. Rodents were captured, and plasma samples were taken from dogs in 48 households from Ucú, Yucatán, Mexico. A spleen sample (rodents) and plasma (dogs) were used in the propagation of Rickettsia on Vero cells. These infected cells were used in the extraction of genomic DNA. Rickettsia DNA was identified using a semi-nested PCR (snPCR); some products were sent for sequencing. The recovered sequences were analysed with bioinformatics programs, and a phylogenetic tree was built to determine the Rickettsia species. One hundred animals were sampled: 36 synanthropic rodents and 64 dogs. The snPCR evidenced the presence of Rickettsia DNA in 10 rodents (10/36, 27.8%) and 18 dogs (18/64, 28.1%), which represents a global frequency of 28% (28/100) in this study. The bioinformatics analysis yielded homology to R. parkeri and was demonstrated in the phylogenetic tree. The first evidence of the presence of R. parkeri in synanthropic rodents (Mus musculus) from Mexico is presented; likewise, the participation of domestic dogs in the transmission cycle of this bacterium with potential importance in public health is confirmed.