Recombination Resulting in Virulence Shift in Avian Influenza Outbreak, Chile

Suarez, David L.; Senne, Dennis A.; Banks, Jill; Brown, Ian H.; Essen, Steve; Lee, Chang-Won; Manvell, R. J.; Mathieu-Benson, Christian; Moreno, Valentina; Pedersen, Janice C.; Panigrahy, B.; Rojas, Hernán; Spackman, Erica; Alexander, D. J.

doi:10.3201/eid1004.030396

Cited by 305 publications

(244 citation statements)

References 26 publications

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“…Recombination plays an important role in the evolution of pathogens, especially contributing to virulence (Joseph et al, 2011;Sangal et al, 2010;Suarez et al, 2004;Wirth et al, 2006). Several factors including restriction-modification systems and CRISPR-Cas systems are involved in regulating gene flow between strains by providing immunity against the invading DNA.…”

Section: Discussionmentioning

confidence: 99%

“…The emergence of nontoxigenic strains may indicate a change in evolutionary dynamics as a result of strong selection by the vaccine. Alterations in virulence have often been associated with high frequencies of recombination in pathogens (Joseph et al, 2011;Suarez et al, 2004;Wirth et al, 2006) and this also appears to be playing an important role in the evolution of C. diphtheriae (Bolt et al, 2010;Mokrousov, 2009). It is now clear that the primary niche of C. diphtheriae in humans, the upper respiratory tract, is a hotbed of horizontal gene transfer between pathogens (Marks et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

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Novel configurations of type I and II CRISPR–Cas systems in Corynebacterium diphtheriae

2013

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Clustered regularly interspaced short palindromic repeats (CRISPRs) are major barriers to recombination through recognition of invading nucleic acids, such as phage and plasmids, and promoting their degredation through the action of CRISPR associated (Cas) proteins. The genomic comparison of 17 Corynebacterium diphtheriae strains led to the identification of three novel CRISPR-Cas system variants, based on the Type II (Type II-C) or type I-E systems. The type II-C system was the most common (11/17 isolates) but it lacked the csn2 and cas4 genes that are involved in spacer acquisition. We also identified that this variant type II-C CRISPR-Cas system is present in other bacteria, and the first system was recently characterized in Neisseria meningitidis. In the remaining isolates, the type II-C system was replaced by a variant of type I-E (I-E-a), where the repeat arrays are inserted between the cas3 and cse1 genes. Three isolates with the type II-C system also possess an additional variant of type I-E (I-E-b), elsewhere in the genome, that exhibits a novel divergent gene organization within the cas operon. The nucleotide sequences of the palindromic repeats and the cas1 gene were phylogenetically incongruent to the core genome. The G+C content of the systems is lower (46.0-49.5 mol%) than the overall DNA G+C content (53 mol%), and they are flanked by mobile genetic elements, providing evidence that they were acquired in three independent horizontal gene transfer events. The majority of spacers lack identity with known phage or plasmid sequences, indicating that there is an unexplored reservoir of corynebacteriophages and plasmids. These novel CRISPR-Cas systems may represent a unique mechanism for spacer acquisitions and defence against invading DNA.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Novel configurations of type I and II CRISPR–Cas systems in Corynebacterium diphtheriae

2013

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“…Despite likely limited sampling, recent outbreaks of AI infections have been documented in South America. For example, a highly pathogenic H7N3 outbreak was reported among poultry in Chile during 2002, antibodies to H1N1 and H3N2 have been reported in wild and domestic birds in Brazil, and a H9 influenza strain has been detected among poultry in Colombia 2 , 3 . In Peru, the presence of AIV has never been reported.…”

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confidence: 99%

Avian influenza and poultry workers, Peru, 2006

Ortiz

Kochel

Capuano

et al. 2007

Influenza Resp Viruses

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Background Currently numerous countries in Asia, Africa and Europe are encountering highly pathogenic avian influenza (AI) infections in poultry and humans. In the Americas, home of the world’s largest poultry exporters, contingency plans are being developed and evaluated in preparation for the arrival of these viral strains. Objectives With this cross‐sectional study, to our knowledge the first in its kind in Central or South America, we sought to learn whether Peruvian poultry workers had evidence of previous AI infection and if so, to determine the risk factors for infection. Methods We performed a cross‐sectional seroprevalence study among 149 workers on a Peruvian poultry farm (132 exposed to poultry and 17 non‐exposed controls), serum samples were tested for human influenza virus exposure using a hemagglutination inhibition (HI) assay. Microneutralization assays were performed on all serum samples to detect antibodies against prototypic AI strains H4 through H12. Results Using multivariate proportional odds modeling we found that the prevalence of elevated titers against AI viruses was low in both groups, exposed and non‐exposed controls. Conclusions No evidence of previous AI infection among Peruvian poultry workers was found in this first cross‐sectional study performed in South America. This first occupational study of AI in Latin America was encouraging, but it likely reflects the sector of poultry production with higher biosecurity.

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“…There are some sero-epidemiological studies performed in cormorants and penguins of Ecuador, seashore birds and giant petrels of Argentina, evidencing the exposure of these birds to the virus, but no viral isolations were performed in the assessed species (Uhart et al 2003, Travis et al 2006a, 2006b, D'Amico et al 2007). In an avian influenza outbreak in commercial poultry farms in Chile, in 2002, it was concluded that it was caused by influenza A virus subtype H7N3 (Suarez et al 2004). Later on, an ancestor was identified from a resident bird of Bolivia (Anas cyanoptera orinmous) collected in 2001.…”

Section: Americamentioning

confidence: 99%

Avian influenza: Eco-epidemiological aspects of the virus in its natural hosts, the migratory waterfowls

Montalvo-Corral

Reyes‐Leyva

Hernández

2010

Rev. chil. hist. nat.

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Avian influenza viruses produce mainly respiratory and intestinal diseases. Their relevance in the generation of pandemic strains has led to a large amount of research to understand their distribution in nature, as well as the relations that become established for the effective transmission among different hosts. Waterfowl have been recognized as their natural reservoir and they play an important role in the propagation and generation of the diversity of these viruses. The emergence of new influenza viruses with pandemic potential among the human population (H5N1 of avian origin or recombinant H1N1 with avian segments) point our lack of information on many aspects of the ecology and epidemiology of these viruses in their natural hosts to enable the implementation of more effective prevention and control measures. In this review, we attempt to make a critical essay on the current state of knowledge on the biotic and abiotic factors that influence the ecology and epidemiology of the influenza A viruses in wild birds.Key words: avian influenza, ecology, epidemiology, migratory birds. RESUMENLos virus influenza ocasionan enfermedades respiratorias e intestinales. Su importancia en la generación de cepas pandémicas ha conducido a la realización de intensa investigación científica para entender y conocer su distribución en la naturaleza, así como las relaciones que se establecen para la transmisión efectiva entre diferentes hospederos. Las aves acuáticas principalmente del orden Anseriformes, se han reconocido como el reservorio de estos virus y tienen una participación crucial en la propagación y generación de diversidad de estos virus. La emergencia de nuevos virus influenza con potencial pandémico entre la población humana (H5N1 de origen aviar y el actual virus pandémico H1N1 que presenta segmentos aviares), resalta la falta de información sobre muchos aspectos de la ecología y epidemiología de estos virus en sus hospederos naturales, que permitan la implementación de medidas más efectivas de prevención y control. En esta contribución revisamos el estado del arte del conocimiento sobre los factores bióticos y abióticos que influyen en la ecología y epidemiología de los virus influenza en aves silvestres.

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Recombination Resulting in Virulence Shift in Avian Influenza Outbreak, Chile

Cited by 305 publications

References 26 publications

Novel configurations of type I and II CRISPR–Cas systems in Corynebacterium diphtheriae

Novel configurations of type I and II CRISPR–Cas systems in Corynebacterium diphtheriae

Avian influenza and poultry workers, Peru, 2006

Avian influenza: Eco-epidemiological aspects of the virus in its natural hosts, the migratory waterfowls

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