RESUMO
Norovirus outbreaks occur frequently in Denmark and it can be difficult to establish whether apparently independent outbreaks have the same origin. Here we report on six outbreaks linked to frozen raspberries, investigated separately over a period of 3 months. Norovirus from stools were sequence-typed; including extended sequencing of 1138 bp encompassing the hypervariable P2 region of the capsid gene. Norovirus was detected in 27 stool samples. Genotyping showed genotype GI.Pb_GI.6 (polymerase/capsid) with 100% identical sequences. Samples from five outbreaks were furthermore identical over the variable capsid P2 region. In one outbreak at a hospital canteen, frozen raspberries was associated with illness by cohort investigation (relative risk 6·1, 95% confidence interval 3·2-11). Bags of raspberries suspected to be the source were positive for genogroup I and II noroviruses, one typable virus was genotype GI.6 (capsid). These molecular investigations showed that the apparently independent outbreaks were the result of one contamination event of frozen raspberries. The contaminated raspberries originated from a single producer in Serbia and were originally not considered to belong to the same batch. The outbreaks led to consultations and mutual visits between producers, investigators and authorities. Further, Danish legislation was changed to make heat-treatment of frozen raspberries compulsory in professional catering establishments.
Assuntos
Infecções por Caliciviridae/epidemiologia , Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Gastroenterite/epidemiologia , Norovirus/genética , RNA Viral/análise , Dinamarca/epidemiologia , Alimentos Congelados/intoxicação , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rubus/intoxicação , Análise de Sequência de RNARESUMO
We report here new recombinants between the norovirus II.4 Sydney 2012 and the II.4 New Orleans 2009 variants. This demonstrates that the II.4 Sydney 2012 variant is undergoing further diversification and suggests a potential for rapid evolution. We also provide primers, which allow the amplification and sequencing of both the current New Orleans 2009 and Sydney 2012 variants and the new II.4 New Orleans 2009/II.4 Sydney 2012 recombinants for more accurate surveillance and transmission tracking.
Assuntos
Doenças Transmissíveis Emergentes/virologia , Norovirus/genética , Vírus Reordenados/genética , Infecções por Caliciviridae/genética , Doenças Transmissíveis Emergentes/genética , Dinamarca , Variação Genética , Humanos , Norovirus/isolamento & purificação , Vírus Reordenados/isolamento & purificaçãoAssuntos
Doenças Transmissíveis Emergentes/virologia , Surtos de Doenças , Gastroenterite/epidemiologia , Norovirus/genética , Austrália/epidemiologia , Doenças Transmissíveis Emergentes/epidemiologia , DNA Viral/genética , Dinamarca/epidemiologia , Gastroenterite/virologia , Variação Genética , Genótipo , Humanos , Dados de Sequência Molecular , Nova Orleans/epidemiologia , Norovirus/classificação , Norovirus/isolamento & purificação , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estações do Ano , Análise de Sequência de DNARESUMO
Globally, surveillance systems showed an increasein norovirus activity in late 2012. Molecular datashared through the NoroNet network suggest thatthis increase is related to the emergence of a newnorovirus genotype II.4 variant, termed Sydney 2012.Healthcare institutions are advised to be prepared fora severe norovirus season.
Assuntos
Infecções por Caliciviridae/epidemiologia , Gastroenterite/virologia , Norovirus/genética , Sequência de Aminoácidos , Austrália/epidemiologia , Infecções por Caliciviridae/diagnóstico , Infecções por Caliciviridae/virologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/virologia , DNA Viral/genética , Surtos de Doenças , Gastroenterite/diagnóstico , Gastroenterite/epidemiologia , Variação Genética , Genótipo , Humanos , Incidência , Norovirus/classificação , Norovirus/isolamento & purificação , Filogenia , Vigilância da População , RNA Viral/genética , RNA Viral/isolamento & purificação , Análise de Sequência de DNARESUMO
Ageing is associated with a decrease in the ability of cells to cope with environmental challenges. This is due partly to the attenuation of a primordial stress response, the so-called heat shock (HS) response, which induces the expression of heat shock proteins (HSPs), composed of chaperones and proteases. The attenuation of the HS response during ageing may be responsible for the accumulation of damaged proteins as well as abnormal regulation of cell death. Maintenance of the HS response by repeated mild heat stress causes anti-ageing hormetic effects on cells and organisms. Here, we describe the molecular mechanism and the state of the HS response as well as the role of specific HSPs during ageing, and discuss the possibility of hormetic modulation of ageing and longevity by repeated mild stress.