H6N8 avian influenza virus in Antarctic seabirds demonstrates connectivity between South America and Antarctica.

Wild aquatic birds are the natural reservoirs of avian influenza viruses (AIVs). It is estimated that 100 million seabirds live in the Antarctic Peninsula and adjacent islands, regularly encountering migratory birds that use the islands to nest. Between 2010 and 2013, we collected samples from 865 seabirds in Elephant, King George and Livingston islands, around Antarctica Peninsula: chinstrap penguin (n = 143); gentoo penguin (n = 208); Adelie penguin (n = 46); brown skua (n = 90); Cape petrel (n = 115) and southern giant petrel (n = 263). Serum (n = 673) samples were analysed by competitive ELISA and swabs (n = 614) were tested by one step real-time RT-PCR for avian influenza virus (AIV). Sera from 30 chinstrap penguins, 76 brown skuas and a single Adelie penguin were seropositive for AIV. Thirteen swab samples were AIV positive by RT-PCR, and complete genome sequences of H6N8 AIVs isolated from brown skua and chinstrap penguin in 2011 were obtained. Phylogenetic analyses indicated that all gene segments of the H6N8 viruses were closely related to Argentinian and Chilean AIVs. The prevalence with which we identified evidence for AIVs infection in various Antarctic seabirds suggest viral circulation in Antarctic avifauna and interspecies viral transmission in the sub-Antarctic region.

Bovine leukaemia virus genotypes 5 and 6 are circulating in cattle from the state of São Paulo, Brazil.

PURPOSE: Enzootic bovine leucosis (EBL) is a silent disease caused by a retrovirus [bovine leukaemia virus (BLV)]. BLV is classified into almost 10 genotypes that are distributed in several countries. The present research aimed to describe two BLV gp51 env sequences of strains detected in the state of São Paulo, Brazil and perform a phylogenetic analysis to compare them to other BLV gp51 env sequences of strains around the world. METHODOLOGY: Two bovines from different herds were admitted to the Bovine and Small Ruminant Hospital, School of Veterinary Medicine and Animal Science, University of São Paulo, Brazil. In both, lymphosarcoma was detected and the presence of BLV was confirmed by nested PCR. The neighbour-joining algorithm distance method was used to genotype the BLV sequences by phylogenetic reconstruction, and the maximum likelihood method was used for the phylogenetic reconstruction. The phylogeny estimates were calculated by performing 1000 bootstrap replicates. RESULTS: Analysis of the partial envelope glycoprotein (env) gene sequences from two isolates (25 and 31) revealed two different genotypes of BLV. Isolate 25 clustered with ten genotype 6 isolates from Brazil, Argentina, Thailand and Paraguay. On the other hand, isolate 31 clustered with two genotype 5 isolates (one was also from São Paulo and one was from Costa Rica). The detected genotypes corroborate the results of previous studies conducted in the state of São Paulo, Brazil. The prediction of amino acids showed substitutions, particularly between positions 136 and 150 in 11 out of 13 sequences analysed, including sequences from GenBank. CONCLUSION: BLV is still important in Brazil and this research should be continued.