Bruno Marques Teixeira

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses with a worldwide distribution and great impact on the health of domestic cats. The Jericoacoara National Park is a region of environmental protection, in the State of Ceará, and contains the Jericoacoara Village, which is an important tourist destination in Brazil. The aims of this study were to verify the prevalence of FIV and FeLV in domestic cats from Jericoacoara Village, as well as the risk factors, clinical signals and hematological changes associated with infection with these feline retroviruses. Samples from 113 cats were collected and tested using anti-FIV antibody and FeLV p27 screening; sequencing and phylogenetic analysis of the gag gene were performed to confirm the FIV subtype. Fourteen cats (12.4%) tested positive for FIV and twelve (10.6%) tested positive for FeLV. The analysis of risk factors for FIV showed that age was a statistically significant risk factor (p=0.001). Dehydration (p=0.008) and hyperproteinemia (p=0.041) were statistically associated with FIV infection. The analysis of risk factors for FeLV showed that cats from high density environments are more likely to become infected than cats from houses with few animals, stray cats, and community cats (p=0.001). No statistical association was found between the clinical and hematological alterations with FeLV infection. The phylogenetic analysis of sequences from nine FIV-positive animals revealed that samples belonged to FIV subtype B. The data found in the study suggest the need to intensify the control of these feline retroviruses in this environmental protection area.

In Brazil, 19 species of the genus Ornithodoros (Acari: Argasidae) have been reported. The medical and veterinary importance of Ornithodoros ticks has increased substantially in recent decades, with the discovery of various relapsing fever Borrelia infecting Ornithodoros ticks. Herein, argasid ticks were collected during 2019–2020 from caves, abandoned nests and homes in various regions of Ceará State, Brazilian semiarid—Caatinga biome. In total, 289 ticks were collected and identified into five species: Ornithodoros cavernicolous (176 specimens), Ornithodoros fonsecai (81), Ornithodoros mimon (12), Ornithodoros rietcorreai (4), and a fifth species provisionally retained as Ornithodoros sp. Ubajara. Tick identifications were corroborated by a phylogenetic analysis inferred using the 16S rRNA gene. To extend the molecular characterization, DNA samples were tested by an additional PCR assay targeting the nuclear Histone 3 (H3) gene. Because there were no H3 sequences of argasids in GenBank, we extended this PCR assay for additional Ornithodoros species, available in our laboratory. In total, 15 partial sequences of the H3 gene were generated for 10 Ornithodoros species, showing 0% intraspecific polymorphism, and 1.5–11.6% interspecific polymorphism. Phylogenetic analyses inferred segregated Ornithodoros sp. Ubajara as a potential novel species. Our results also highlight the potential of the H3 gene for deeper phylogenetic analyses of argasids. The present study provides new data for argasid ticks of the genus Ornithodoros in the Caatinga biome. Because some of these tick species are human-biting ticks, active surveillance for the incidence of human infection due to Ornithodoros-borne agents is imperative in the Caatinga biome.