Estudo soro-epidemiológico e molecular da infecção por Rickettsia spp. em cães do ambiente urbano e rural na mesorregião do Oeste maranhense, Microrregião de Imperatriz, Brasil

Abstract

Rickettsiae are obligate intracellular parasites responsible for several human diseases known as rickettsial diseases, which are transmitted through the bite of arthropod vectors such as ticks, fleas and lice. Therefore, study the prevalence of infection with Rickettsia spp. in dogs and biological vectors of urban and rural environment in the microregion of Imperatriz, State Maranhão through serological and molecular techniques. 300 dogs sera were collected and tested against antigens riquetsiais by indirect immunofluorescence assay (IFA). Ectoparasites were collected from infected animals, and identified according to morphological characteristics, then we performed DNA extraction from ticks and fleas, and processed by polymerase chain reaction (PCR) to investigate the gene gltA and ompA, followed by characterization through molecular genetic sequencing. The results of the IFA showed that 1,67% (5/300) of the samples contained antibodies that reacted to a type of Rickettsia, it was determined R. rickettsii and R. amblyommii as probable antigen responsible for the infection. Ctenocephalides felis, Heterodoxus spininger and Riphicephalus sanguineus were identified infesting 50% of dogs (150/300). 369 ticks R. sanguineus we collected, of which 235 specimens were subjected to PCR, all sample were negative. 106 fleas C. felis collected, of then subjected to PCR, and of these 78,30% (83/106) were positive for gltA gene research, and these samples 61,45% (51/83) remained positive in ompA2. The amplified products were the two strands of DNA sequenced and showed similarity with the nucleotide sequence of Rickettsia felis. The data obtained showed that infection by Rickettsia spp. Occurs in dogs from rural and urban environment of the microregion Imperatriz.