Carrapatos e riquétsias em parque urbano de Uberlândia, Minas Gerais: ecologia e biodiversidade associadas

Abstract

The Parque Municipal do Sabiá is the main public park in Uberlândia and an urban refuge of local biodiversity. Surveys of ticks in mammals and birds and questing ticks were accomplished between March 2011 and May 2013. Free-living ticks were Amblyomma sculptum (648 adults and 747 nymphs) and Amblyomma dubitatum (36 adults and 85 nymphs), and 22 Amblyomma sp larvae clusters. A. sculptum was the most abundant species with 92% of the sample. A. sculptum adults predominated in the rainy season (U = 26, p <0.05) and nymphs in the dry season (U = 4, p <0.05). Thirty-four capybaras were captured and removed from the park during the years 2010 and 2011. Twenty-five (78.1%) capybaras were infested with 1272 ticks of the species A. dubitatum and A. sculptum, being the former the most abundant species (61.2%). Eighteen capybaras were anti-Rickettsia seroreactivity with titles from 64 to 1024. Five animals exhibited homologous reaction against the antigens of R. rickettsii and R. bellii. No Rickettsia was detected by PCR in free living ticks and capybaras. Small mammals were Oecomys sp (n = 59), Rhipidomys sp (n = 6), Rattus norvegicus (n = 8), Oligoryzomys sp. (n = 1), Dasypus novemcinctus (n = 1), Dasyprocta azarae (n = 1), Cavia aperea (n = 3), Didelphis albiventris (n = 30) and Gracilinanus agilis (n = 21). Of these, 33.8% harbored 655 ticks (13 adults, 137 nymphs and 505 larvae). The larvae accounted for 76.9% of ticks and 94.6% of these belong to the genus Amblyomma. Among the nymphs, A. dubitatum corresponded to 71.5% of the sample, while A. sculptum represented 17.5% and I. loricatus 10.9%. The infestation of ticks in small mammals was higher in the dry season than in the rainy season (U = 2256, p <0.05). D. albiventris prevalence was 83.3% and this species harbored 89.7% of all ticks collected. The overall seroprevalence of Rickettsia spp. in small mammals was 45.6% (52 positive in 114 samples tested). Overall, the titers were low (64-2048) and R. bellii was the species with the largest number of homologous reactions (10). Rattus norvegicus presented discrepant serology with high titers for all tested rickettsiae. 320 birds were captured, from 52 species, 22 families (14 of passerine Order and eight non-passerines). The family with the largest number of individuals was Paruliidae. Foraging guild with the highest number of species was omnivorous (n = 21), comprising 158 individuals, followed by insectivores (16 species, 97 individuals) and 57 ticks (39 Amblyomma sp larvae and 18 nymphs Amblyomma longirostre, Amblyomma nodosum and A. sculptum were collected. The overall prevalence of tick infestation was 9.4% (30 individuals in 320 birds examined). Birds foraging in the understory and lower understory were more prevalent than birds foraging at other height. The prevalence of ticks on birds was higher in the dry season compared to the rainy season. The whole results indicate the circulation of Spotted Fever Group Rickettiae and R. bellii in Parque Municipal do Sabiá.