Detection, epidemiology and characterization of VP6 and VP7 genes of group D rotavirus in broiler chickens

Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, BrasilMinistério da Agricultura. Laboratório Nacional Agropecuário. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Rotaviruses infect humans and animals and are classified into eight groups (A to H). Group D rotavirus (RVD) has been described in birds, although relatively few reports are available. The present study focused on RVD, including epidemiological and molecular aspects of samples collected from broiler chickens in the state of Pará, Brazil. A total of 85 faecal samples were collected between 2008 and 2011 from 37 chicken farms located in eight different municipalities. The viral double-stranded RNA was extracted from faecal suspensions and analysed using polyacrylamide gel electrophoresis (PAGE), followed by reverse transcriptase-polymerase chain reaction (RTPCR) and nucleotide sequencing of the VP6 and VP7 genes. Comparing the positive results, 16.5 per cent (14/85) were obtained by PAGE and 35.3 per cent (30/85) by RT-PCR. Samples from seven of eight municipalities were positive for RVD and infections were recorded in 17 (45.9 per cent) of 37 chicken farms. The RVD infection rate was significantly higher in the 16-day to 30-day age group (62.2 per cent; 23/37) compared with other ages. No consistent relationship was found between the infection rate and either the population density in poultry houses or the climatic conditions. The nucleotide sequences of the VP6 gene were 89.9 to 90.9 per cent similar to the prototype strain 05V0049 and were 88.3 to 100 per cent similar among themselves; VP7 gene nucleotide sequences were 84.3 to 85.4 per cent similar to the prototype strain 05V0049 and 93.8 to 100 per cent similar among themselves. Overall, this study provides new insights into the epidemiology and genome characterization of group D rotaviruse