Detection and molecular characterization of Avipoxvirus in Culex sp. naturally infected and collected in peridomiciliar areas in the municipality of Seropédica, State of Rio de Janeiro.
Avian pox; Culex; Phylogeny; Molecular Detection; Avipoxvirus.
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 naturally infected mosquitoes of the Culex sp. by Avipoxvirus 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. 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 all specimens collected, a total of 13.66% (41/300) of the samples tested were considered positive in PCR, where 7% (21/300) were from Campo Lindo, 4.67% (14/300) from São Miguel and 2% (6/300) from Valão das Louças. The phylogenetic analysis was performed comparing 347 sequences available in GenBank, in order to group the subclades A1 to A7 and B1 to B3, and, for the first time in Brazil, it was possible to report the presence of subclade A1 in samples of naturally infected Culex sp. by Avipoxvirus. 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). This work enabled the development of an effective PCR technique for the detection of Avipoxvirus directly in Culex sp., 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.