Detecção e caracterização molecular do Poxvírus Aviário em Culex sp. coletados no peridomicílio de áreas rurais e periurbanas no município de Seropédica, Estado do Rio de Janeiro

Abstract

Avian Pox is a highly contagious viral disease whose largest geographical range of cases covers tropical and subtropical regions, affecting both domestic and wild birds. Experimental studies show that the main form of transmission occurs during blood feeding by vectors of the genus Culex, previously fed with the blood of infected birds. Therefore, the aim of this study was to establish the frequency of Culex sp. with Avipoxvirus DNA through PCR assay, in the municipality of Seropédica, Rio de Janeiro and then perform a phylogenetic analysis based on the p4b gene from positive samples. In this study, 2839 mosquitoes belonging to Anopheles, Aedes and Culex genera were collected, with the Culex sp. genus being the most abundant, comprising 96.23% (2732/2839) of the total amount, where the Avipoxvirus detection was conducted on 300 fed females from the neighborhoods: São Miguel, Valão das Louças and Campo Lindo. Of the collected specimens, a total of 13.66% (41/300) of the samples of females tested were positive in the detection reaction, where 13.63% of the positives (21/154) were collected at Campo Lindo neighborhood, 16.67% (16/96) at São Miguel and 12% (6/50) at Valão das Louças. There was no significant difference in the frequency of Avipoxvirus in Culex sp. among the neighborhoods analyzed (p>0.05).The phylogenetic analysis was performed comparing 347 sequences available in GenBank, in order to group the subclades A1 to A7, B1 to B3 and C, and, for the first time in Brazil, it was possible to report the presence of subclade A1 in samples of Culex sp. with Avipoxvirus DNA. The evolutionary distance of the p4b gene of the sequenced samples, compared between the evaluated areas, was able to demonstrate larger genetic divergence in rural areas (0.0061±0.0021) when compared to periurban areas (0.0038±0.0016) in this study. This work enabled the improvement of an effective PCR technique for the detection of Avipoxvirus directly in Culex sp. DNA, in addition to complementing data on vector biology and improving the monitoring and control techniques of Avian Pox in the State of Rio de Janeiro