RESUMO
Phylogenetic analysis of 22 Black queen cell virus (BQCV) genotypes collected from honeybee colonies in Poland, Austria and Hungary was performed on a partial helicase enzyme coding region (ORF1) and on a partial structural polypeptide coding region (ORF2). While the phylogeny based on the ORF2 region showed--with the exception of one strain from Poland--clustering of the genotypes corresponding to their geographic origin, the ORF1-based tree exhibited a completely different distribution of the Polish strains: three of them clustered within a branch clearly separated from all other central European BQCVs, while four other Polish strains remained well within the central European BQCV genotypes. In order to investigate this discrepancy in more detail, the nearly complete genome sequences of the three differing Polish strains were determined, together with one Hungarian sample. The sequences were aligned to each other and to the reference strain from South-Africa. Comparison of the different genome regions revealed that the 5'-UTR and the intergenic regions of the BQCV genome are highly conserved with longer homologous sections. ORF1 (non-structural protein coding region) was found more variable compared to ORF2 (structural protein coding region). The 5'-proximal third of ORF1 was particularly variable and contained several deletions/insertions. The sudden changes in the similarity levels of BQCV strains in different genomic regions are indicative of preceding recombination events.
Assuntos
Abelhas/virologia , Dicistroviridae/genética , Genoma Viral , Filogenia , Animais , Áustria , Sequência de Bases , Evolução Molecular , Geografia , Humanos , Hungria , Dados de Sequência Molecular , PolôniaRESUMO
Honeybees originating from 10 different countries (Austria, Poland, Germany, Hungary, Slovenia, Nepal, Sri Lanka, the United Arab Emirates, Canada, and New Zealand) located on four continents were analyzed for the presence of deformed wing virus (DWV) nucleic acid by reverse transcription-PCR. Two target regions within the DWV genome were selected for PCR amplification and subsequent sequencing, i.e., a region within the putative VP2 and VP4 structural-protein genes and a region within the RNA helicase enzyme gene. DWV nucleic acid was amplified from 34 honeybee samples representing all the above-mentioned countries with the notable exception of New Zealand. The amplification products were sequenced, and phylogenetic analyses of both genomic regions were performed independently. The phylogenetic analyses included all sequences determined in this study as well as previously published DWV sequences and the sequences of two closely related viruses, Kakugo virus (KGV) and Varroa destructor virus 1 (VDV-1). In the sequenced regions, the DWV genome turned out to be highly conserved, independent of the geographic origins of the honeybee samples: the partial sequences exhibited 98 to 99% nucleotide sequence identity. Substitutions were most frequently observed at the same positions in the various DWV sequences. Due to the high level of sequence conservation, no significant clustering of the samples in the phylogenetic trees could be identified. On the other hand, the phylogenetic analyses support a genetic segregation of KGV and VDV-1 from DWV.
Assuntos
Abelhas/virologia , Filogenia , Vírus de RNA/genética , RNA Viral/genética , Animais , Sequência Conservada/genética , Evolução Molecular , Genoma Viral/genética , Genótipo , Dados de Sequência Molecular , Mutação Puntual/genética , RNA Helicases/genética , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Homologia de Sequência , Proteínas não Estruturais Virais/genética , Proteínas Estruturais Virais/genéticaRESUMO
Nosema ceranae was discovered in Apis cerana, Eastern honeybee first. Until recently A. cerana has been considered the only host to this parasite. A few years ago N. ceranae was recorded in honey bee Apis mellifera. It appeared that N. ceranae is more pathogenic for A. mellifera than Nosema apis. This parasite can cause significant losses in bee colonies. Bees die without symptoms observed in nosemosis caused by N. apis such as diarrhea.
Assuntos
Abelhas/classificação , Abelhas/parasitologia , Nosema/isolamento & purificação , Animais , Nosema/patogenicidade , Especificidade da EspécieRESUMO
Reverse transcription-PCR assays have been established for a quick, sensitive, and specific diagnosis of acute bee paralysis virus (ABPV), a common virus of the honeybee (Apis mellifera), directly from clinical samples. A 3,071-nucleotide fragment of the ABPV genome, which includes the entire capsid polyprotein gene, was amplified from Austrian, German, Polish, and Hungarian ABPV samples and sequenced, and the sequences were compared. The alignment of a smaller fragment with ABPV sequences from the United States and the United Kingdom revealed nucleotide identity rates between 89 and 96%, respectively. Phylogenetic trees which display the molecular relationship between the viruses of different geographic origin were constructed.
