Analyse cellulaire et moléculaire de l'autophagie (effets de carences en carbone chez la plante modèle Arabidopsis thaliana et la plante d'intérêt économique Vigna unguiculata)

Une approche biochimique, cytologique et moléculaire a été utilisée pour étudier l'autophagie, un processus catabolique par lequel les cellules détruisent des portions de leur propre cytoplasme. L'autophagie a été induite par la privation de sucre des cellules d'Arabidopsis thaliana et de Vigna unguiculata cultivées en suspension. Le dénombrement des structures d'autophagie (autophagosomes et structures pré-autophagosomales) montre que les cellules répondent au stress de carence par une poussée autophagique rapide et massive. Nous avons montré que les gènes d'autophagie AtATG3, AtATG4a, AtATG4b, AtATG7 and AtATG8a-i, impliqués dans la voie de lipidation d'ATG8, semblable à une ubiquitination, sont régulés positivement de manière coordonnée au tout début de la carence. Ils sont exprimés par vagues successives parallèlement aux remodelages cytologiques et biochimiques. Une approche pharmacologique préliminaire suggère que la voie TOR (target of rapamycine) joue un rôle important dans la signalisation de l'autophagie.Biochemical, cytological and molecular methods have been used to study autophagy, a catabolic process by which cells degrade parts of their own cytoplasm. Autophagy was induced in Arabidopsis thaliana and Vigna unguiculata suspension-cultured cells by carbon starvation. Quantification of autophagy-related structures (autophagosomes and pre-autophagosomat structures) shows that cells respond to the stress signal by a rapid and massive burst of autophagic activity. It is shown that the autophagy-related genes AtATG3, AtATG4a, AtATG4b, AtATG7 and AtATG8a-i, involved in the ATG8 ubiquitination-like conjugation pathway, are up-regulated in a coordinated manner at the onset of starvation. They are expressed in successive waves that parallel the biochemical and cytological remodeling that takes place. A preliminary pharmacological approach suggests that the TOR (target of rapamycin) pathway can play an important role in autophagy signalling.DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

Emerging Infectious Diseases

p. 1843-1846Analysis of 27 rotavirus strains from vaccinated and unvaccinated children revealed reassortment events in 3 strains: a gene derived from a vaccine; a gene acquired from a circulating strain; and reassortment between circulating strains. Data suggest that the widespread use of this monovalent rotavirus vaccine may introduce vaccine genes into circulating human rotaviruses or vice versa

Infection, Genetics and Evolution

Texto completo: acesso restrito. p. 395–402In 2009 the World Health Organization recommended the use of group A rotavirus (RVA) vaccines in all national immunization programs (NIPs) in order to control severe RVA gastroenteritis disease. In Brazil, Rotarix™ was introduced in the NIP in March 2006, and a significant reduction in mortality rates among children ⩽5 years old was observed, especially in the Northern and Northeastern Brazil. In the current study the 11 gene segments of six Brazilian G1P[6] RVA strains, isolated in 2009 and 2010 from vaccinated children, were analyzed in order to investigate if the genetic composition of these strains might help to elucidate why they were able to cause acute gastroenteritis in vaccinated children. All six Brazilian RVA strains revealed a complete Wa-like genotype constellation: G1-P[6]-I1-R1-C1-M1-A1-N1-T1-E1-H1. Phylogenetic analysis showed that all six strains were nearly identical and showed a close genetic relationship with contemporary typical human Wa-like RVA strains. These results suggests that the fact that these strains were able to cause acute gastroenteritis in vaccinated children is likely not due to the genetic background of the strains, but rather to other factors such as host relating factors, co-infecting pathogens or vaccine efficacy. P[6] RVA strains are detected rather occasionally in humans in most regions of the world, except for South Asia and Sub-Saharan Africa. However, recently two studies conducted in Brazil showed the circulation of G12P[6] and G2P[6]. This is the first report on the detection and complete genome analyses of G1P[6] RVA strains in Brazil. Surveillance studies will be crucial to further investigate the prevalence of this genotype in the Brazilian population, and the efficacy of current licensed vaccines, which do not contain the P[6] genotype

Evidence of Vaccine-related Reassortment of Rotavirus, Brazil, 2008–2010

Analysis of 27 rotavirus strains from vaccinated and unvaccinated children revealed reassortment events in 3 strains: a gene derived from a vaccine; a gene acquired from a circulating strain; and reassortment between circulating strains. Data suggest that the widespread use of this monovalent rotavirus vaccine may introduce vaccine genes into circulating human rotaviruses or vice versa

Distinct evolutionary origins of G12P[8] and G12P[9] group A rotavirus strains circulating in Brazil

Program of Research Excellence (PROEP – IOC/Fiocruz/CNPq), the National Council for Scientific and Technological Development (CNPq), project PAPES VI/FIOCRUZ – CNPq, Oswaldo Cruz Institute (IOC/FIOCRUZ), Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES) – project CAPES-MERCOSUL PPCP 023/2011, the General Coordination of Public Health Laboratories – Secretary of Health Surveillance (CGLAB/SVS), and Carlos Chagas Filho Foundation for Research Support of Rio de Janeiro State (FAPERJ). M.Z. was supported by the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT Vlaanderen).Oswaldo Cruz Foundation. Oswaldo Cruz Institute. Laboratory of Comparative and Environmental Virology. Rio de Janeiro, RJ, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Oswaldo Cruz Foundation. Oswaldo Cruz Institute. Laboratory of Comparative and Environmental Virology. Rio de Janeiro, RJ, Brazil.Oswaldo Cruz Foundation. Oswaldo Cruz Institute. Laboratory of Comparative and Environmental Virology. Rio de Janeiro, RJ, Brazil.Oswaldo Cruz Foundation. Oswaldo Cruz Institute. Laboratory of Comparative and Environmental Virology. Rio de Janeiro, RJ, Brazil.University of Leuven. Rega Institute for Medical Research. Department of Microbiology and Immunology. Laboratory of Clinical and Epidemiological. Leuven, Belgium.University of Leuven. Rega Institute for Medical Research. Department of Microbiology and Immunology. Laboratory of Clinical and Epidemiological. Leuven, Belgium.University of Leuven. Rega Institute for Medical Research. Department of Microbiology and Immunology. Laboratory of Clinical and Epidemiological. Leuven, Belgium.Oswaldo Cruz Foundation. Oswaldo Cruz Institute. Laboratory of Comparative and Environmental Virology. Rio de Janeiro, RJ, Brazil.G12 group A rotavirus (RVA) are currently recognized as a globally emerging genotype and have been described in combination with several P-types. In Brazil, G12 RVA strains have been described in the Southern (2003) and Northern (2008 2010) regions, in combination with the P[9] and P[6] genotype, respectively. To date, few complete genomes of G12 RVA strains have been described (none from Brazilian strains), considering G12P[9] genotype just one strain, RVA/Human-tc/THA/T152/1998/G12P[9], has their 11 gene segments characterized. This study aims to determine the genomic constellation of G12P[9] and G12P[8] RVA strains detected in Brazil between 2006 and 2011. Therefore, the eleven gene segments of five Brazilian G12 RVA strains were amplified and sequenced, and the genotype of each gene segment was assigned using phylogenetic analysis. Complete genome analyses of G12 RVA strain circulating between 2006 and 2011 in Brazil revealed a conserved Wa-like genomic constellation for three G12P[8] RVA strains; whereas the two G12P[9] strains possessed distinct reassorted AU-1-like genomic constellations, closely related to the reference strain RVA/Human-tc/THA/T152/1998/G12P [9] in most genes. The results obtained in the current study suggest that G12P [9] (AU-1-like) and G12P[8] (Wa-like) strains detected in different regions of Brazil do not share a common origin. Moreover, while Brazilian G12P[8] RVA strains showed a complete Wa-like human constellation, both G12P[9] strains possessed an NSP1 gene of bovine origin (NSP1), and RVA/Human-wt/BRA/PE18974/2010/G12P[9] also possessed a VP3 gene of canine/feline origin

Distinct evolutionary origins of G12P[8] and G12P[9] group A rotavirus strains circulating in Brazil

G12 group A rotavirus (RVA) are currently recognized as a globally emerging genotype and have been described in combination with several P-types. In Brazil, G12 RVA strains have been described in the Southern (2003) and Northern (2008-2010) regions, in combination with the P[9] and P[6] genotype, respectively. To date, few complete genomes of G12 RVA strains have been described (none from Brazilian strains), considering G12P[9] genotype just one strain, RVA/Human-tc/THA/T152/1998/G12P[9], has their 11 gene segments characterized. This study aims to determine the genomic constellation of G12P[9] and G12P[8] RVA strains detected in Brazil between 2006 and 2011. Therefore, the eleven gene segments of five Brazilian G12 RVA strains were amplified and sequenced, and the genotype of each gene segment was assigned using phylogenetic analysis. Complete genome analyses of G12 RVA strain circulating between 2006 and 2011 in Brazil revealed a conserved Wa-like genomic constellation for three G12P[8] RVA strains; whereas the two G12P[9] strains possessed distinct reassorted AU-1-like genomic constellations, closely related to the reference strain RVA/Human-tc/THA/T152/1998/G12P[9] in most genes. The results obtained in the current study suggest that G12P[9] (AU-1-like) and G12P[8] (Wa-like) strains detected in different regions of Brazil do not share a common origin. Moreover, while Brazilian G12P[8] RVA strains showed a complete Wa-like human constellation, both G12P[9] strains possessed an NSP1 gene of bovine origin (NSP1), and RVA/Human-wt/BRA/PE18974/2010/G12P[9] also possessed a VP3 gene of canine/feline origin.publisher: Elsevier articletitle: Distinct evolutionary origins of G12P[8] and G12P[9] group A rotavirus strains circulating in Brazil journaltitle: Infection, Genetics and Evolution articlelink: http://dx.doi.org/10.1016/j.meegid.2014.04.007 content_type: article copyright: Copyright © 2014 Elsevier B.V.status: publishe

Emerging Infectious Diseases

p. 1843-1846Analysis of 27 rotavirus strains from vaccinated and unvaccinated children revealed reassortment events in 3 strains: a gene derived from a vaccine; a gene acquired from a circulating strain; and reassortment between circulating strains. Data suggest that the widespread use of this monovalent rotavirus vaccine may introduce vaccine genes into circulating human rotaviruses or vice versa

A decade of G3P[8] and G9P[8] rotaviruses in Brazil: Epidemiology and evolutionary analyses

Made available in DSpace on 2015-06-12T13:57:53Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) mariela_gomezetal_IOC_2014.pdf: 1463430 bytes, checksum: 6fecb6e3589ffd45639b062915a313ad (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Comparada e Ambiental. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Comparada e Ambiental. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Comparada e Ambiental. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Comparada e Ambiental. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Comparada e Ambiental. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Comparada e Ambiental. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Comparada e Ambiental. Rio de Janeiro, RJ, Brasil.University of Leuven. Rega Institute for Medical Research. Department of Microbiology and Immunology. Laboratory of Clinical and Epidemiological. Leuven, Belgium.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Comparada e Ambiental. Rio de Janeiro, RJ, Brasil.This study aims to estimate the frequency of group A rotaviruses (RVA) infection with genotypes G3P[8] and G9P[8] in children that suffered from diarrheal disease (DD) between 2001 and 2011 in different Brazilian regions. In addition, the genetic diversity of G3P[8] and G9P[8] RVA strains recovered from vaccinated and non-vaccinated children was assessed. Laboratory-based RVA surveillance included 15,115 cases of DD, and RVA was detected by enzyme immune-assay and/or polyacrylamide gel electrophoresis in 3357 (22%) samples. RVA was genotyped by the semi-nested RT-PCR and among RVA-positive samples, 100 (2.9%) were G3 (63 G3P[8], 32 G3P not typed [NT], and 5 G3P[6]) and 378 (16.2%) were G9 (318 G9P[8], 59 G9P[NT], and 1 G9P[6]). From the G3 and G9 positive samples, 16 and 12, respectively, were obtained from children aged 4–48 months vaccinated with the monovalent vaccine (Rotarix , RV1). Phylogenetic analyses of the VP7 and VP8⁄ encoding genes were performed for 26 G3P[8] and 48 G9P[8] strains. VP8⁄ phylogenetic analysis revealed that all strains analyzed belonged to P[8] lineage III, whereas RV1 belongs to P[8]-I lineage. VP7 analysis revealed that all G3 and G9 strains belonged to G3-lineage III and G9-lineage III. The comparison of the VP7 and VP8⁄ antigenic epitopes regions of Brazilian strains with RV1 strain revealed several amino acid changes. However, no particular differences among Brazilian strains detected before and after vaccine introduction were observed, or among strains detected from vaccinated and non-vaccinated children. Complete genome characterization of four G3P[8] and seven G9P[8] strains revealed a typical conserved human Wa-like genomic constellation. Changes in the genetic diversity of G3P[8] and G9P[8] RVA detected from 2001 to 2011 in Brazil seemed not be related to RV1 introduction in Brazil

The role of human adenoviruses type 41 in acute diarrheal disease in Minas Gerais after rotavirus vaccination

Abstract Human adenovirus species F (HAdV-F) type 40 and 41 are commonly associated with acute diarrheal disease (ADD) across the world. Despite being the largest state in southeastern Brazil and having the second largest number of inhabitants, there is no information in the State of Minas Gerais regarding the role of HAdV-F in the etiology of ADD. This study was performed to determine the prevalence, to verify the epidemiological aspects of infection, and to characterize the strains of human adenoviruses (HAdV) detected. A total of 377 diarrheal fecal samples were obtained between January 2007 and August 2011 from inpatient and outpatient children of age ranging from 0 to 12 years. All samples were previously tested for rotavirus, norovirus, and astrovirus, and 314 of 377 were negative. The viral DNA was extracted, amplified using the polymerase chain reaction and the HAdV-positive samples were sequenced and phylogenetically analyzed. Statistical analyses were performed using the Chi-square test (p < 0.05), considering two conditions: the total of samples tested (377) and the total of negative samples for the remaining viruses tested (314). The overall prevalence of HAdV was 12.47% (47/377); and in 76.60% (36/47) of the positive samples, this virus was the only infectious agent detected. The phylogenetic analysis of partial sequences of 32 positive samples revealed that they all clustered with the HAdV-F type 41. The statistical analysis showed that there was no correlation between the onset of the HAdV infection and the origin of the samples (inpatients or outpatients) in the two conditions tested: the total of samples tested (p = 0.598) and the total of negative samples for the remaining viruses tested (p = 0.614). There was a significant association in the occurrence of infection in children aged 0&#8211;12 months for the condition 1 (p = 0.030) as well as condition 2 (p = 0.019). The occurrence of infections due to HAdV did not coincide with a pattern of seasonal distribution. These data indicate the significant involvement of HAdV-F type 41 in the etiology of ADD in Minas Gerais, which demonstrates the importance of other viral agents in the development of the disease after the introduction of rotavirus vaccine immunization