Pesquisa de Rickettsia spp., Ehrlichia spp. e Anaplasma spp. em carrapatos de vida livre nas mesorregiões Sul Fluminense e Metropolitana do Rio de Janeiro, RJ

Abstract

Ticks are arthropods, mostly obligate ectoparasites, and important pathogens vectors, including viruses, bacteria, protozoa and helminths. This study aimed to identify bacteria of the Rickettsia, Ehrlichia and Anaplasma genus in free-living ticks. The research was conducted in five area located in mesoregions Sul Fluminense and Metropolitana do Rio de Janeiro: Universidade Federal Rural do Rio de Janeiro, National Forest Mario Xavier, both in Seropedica; Itatiaia National Park in Itatiaia; Ammunition Deposit Center in Paracambi; and Training Center of Marambaia Island in Mangaratiba. During the collections drag flannel, chemical trap CO2 and manual scavenging on the clothes and researchers' body were used. The collected ticks were identified and subjected to PCR for Rickettsia spp., Ehrlichia spp. and Anaplasma spp. 14,469 samples of ticks were collected in all the surveyed areas. 9,353 ticks were selected to analysis, and distributed in 372 pools, according to taxonimic classification, evolutionary stage, area, and year of collection. This total consists of 7,273 larvae of Amblyomma, 1 larvae of R. (B.) microplus, 1,952 of Amblyomma nymphs, 120 adults of A. sculptum, 4 adults of A. brasiliense, and 3 adults of A. dubitatum. Among these pools, only two were positive in the screening, one pool being composed of three larvae of Amblyomma spp. collected in the National Forest Mario Xavier and the other pool of 20 nymphs of A. sculptum collected on a place called Sino's beach located in the Island of Marambaia. Data analysis by PCR-RFLP showed that the bands observed in the analysis are Rickettsia bellii. The positivity to R. bellii found in this study is 0.25%. With this result, is possible to confirm that there is Rickettsia circulation in two areas of collection. In both areas which R. bellii circulation was found, there was a presence of capybaras and horses. The molecular search for Ehrlichia and Anaplasma genus revealed negative results for both genus. The occurrence and distribution of ticks observed in this study can be attributed to the environmental conditions, composition of vegetation, and vertebrate hosts' activity; these are related to the different human activities conducted in each collection point throughout the study