42 results on '"Vizzi E"'
Search Results
2. Calicivirus infection in human immunodeficiency virus seropositive children and adults
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Rodríguez-Guillén, L., Vizzi, E., Alcalá, A.C., Pujol, F.H., Liprandi, F., and Ludert, J.E.
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- 2005
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3. Distribution of VP7 serotypes and VP4 genotypes among rotavirus strains recovered from Italian children with diarrhea
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Arista, S., Vizzi, E., Ferraro, D., Cascio, A., and Di Stefano, R.
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- 1997
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4. High incidence of G9P[8] rotavirus infections in Italian children during the winter season 1999–2000
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Arista, S., Vizzi, E., Migliore, M. C., rosa, E. Di, and Cascio, A.
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- 2002
5. Detection and characterization of waterborne gastroenteritis viruses in urban sewage and sewage-polluted river waters in Caracas, Venezuela
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Rodriguez-Diaz, J., Querales, L., Caraballo, L., Vizzi, E., Liprandi, F., Takiff, H., and Betancourt, W.Q.
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Caracas, Venezuela -- Environmental aspects ,Gastroenteritis -- Research ,Water pollution -- Venezuela ,Water pollution -- Research ,Biological sciences - Abstract
The detection and molecular characterization method is used for providing an overview of the epidemiology of waterborne gastroenteritis viruses circulating in urban areas of Caracas, Venezuela. The studies have disclosed relevant epidemiological data on the distribution and persistence of human pathogenic viruses in sewage-polluted waters and have addressed the potential health risks associated with transmission of these viruses through water-related environmental routes.
- Published
- 2009
6. DETECTION OF ENTERIC ADENOVIRUS 40 AND 41 IN STOOL SPECIMENS BY MONOCLONAL-BASED ENZYME IMMUNOASSAYS
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Vizzi, E., Ferraro, D., Antonio Cascio, Di Stefano, R., Arista, S., VIZZI E, FERRARO D, A. CASCIO, DI STEFANO R, and ARISTA S
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adenovirus - Abstract
o examine the role of enteric adenoviruses (Ad40 and Ad41) in children with acute gastroenteritis, we evaluated 273 children with diarrhoea and 137 without enteric symptoms in Palermo, Italy, during an 8-month period. Stools were tested by two home-made monoclonal-based ELISAs to detected genus-specific adenovirus antigen and to type Ad40 and Ad41. Twenty-five samples (6.1%) were found to contain adenovirus, 18 of which were grown in Graham 293 and in HEp-2 cells. Ad40 and Ad41 were detected in 2.6% of children with diarrhoea and in none in the control group, while non-enteric adenoviruses were obtained from both patients (3.2%) and controls (6.5%). Samples containing Ad40 and Ad41 were positive by the virus isolation procedure in Graham and in HEp-2 cells, showing no distinct growth pattern in these cell lines. The evaluation of a latex agglutination test (Adenolex) and of a commercial ELISA (Adenoclone), respectively available for the detection of genus adenovirus antigen and for the typing of Ad40 and Ad41 suggests that both tests enable the identification of enteric adenoviruses in stool specimens, giving results comparable to our ELISAs.
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- 1996
7. First identification in italy of picobirnavirus from faeces of immunocompetent children suffering from acute diarrhea
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Cascio, Antonio, Bosco, M, Vizzi, E, and Arista, A.
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- 1994
8. CARATTERIZZAZIONE ANTIGENICA DI ROTAVIRUS UMANI RISCONTRATI A PALERMO NEGLI ANNI 1989-92
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Vizzi, E., Cascio, Antonio, and Arista, S.
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rotavirus - Published
- 1994
9. APPLICAZIONE DEGLI ANTICORPI MONOCLONALI NELLO STUDIO DELLA VARIABILITA' ANTIGENICA DEI ROTAVIRUS
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Arista, S., Vizzi, E., and Cascio, Antonio
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rotavirus - Published
- 1994
10. Introduction of a new lineage VP7 of rotavirus G1 in the Venezuelan population
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Vizzi, E., primary, Piñeros, O., additional, Alcala, A.C., additional, Naranjo, L., additional, Suarez, J.A., additional, and Liprandi, F., additional
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- 2010
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11. Temporal variation of human rotavirus types circulating in Caracas during 2007-2008
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Vizzi, E., primary, Piñeros, O., additional, Alcala, A.C., additional, Oropeza, M.D., additional, Naranjo, L., additional, Suarez, J.A., additional, Zambrano, J.L., additional, and Liprandi, F., additional
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- 2010
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12. Rotavirus Gastroenteritis in Italian Children: Can Severity of Symptoms Be Related to the Infecting Virus?
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Cascio, A., primary, Vizzi, E., additional, Alaimo, C., additional, and Arista, S., additional
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- 2001
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13. Detection of enteric adenoviruses 40 and 41 in stool specimens by monoclonal antibody-based enzyme immunoassays
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Vizzi, E., primary, Ferraro, D., additional, Cascio, A., additional, Di Stefano, R., additional, and Arista, S., additional
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- 1996
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14. Detection of IgM antibodies specific for measles virus by capture and indirect enzyme immunoassays
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Arista, S., primary, Ferraro, D., additional, Cascio, A., additional, Vizzi, E., additional, and di Stefano, R., additional
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- 1995
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15. Circulation of Chikungunya virus in Aragua state (Venezuela) during the year 2014,Circulación de virus Chikungunya en el estado Aragua (Venezuela) durante el año 2014
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Camacho García, D., Celis, A., Moros, Z., Osorio, J. R., Araujo, R., Alcántara, A., Guerrero, V. P., Tarazón, A., Blanco, R., Vizzi, E., Liprandi, F., Negredo, A. A. I., MARIA PAZ SANCHEZ-SECO, and Pérez, G. C.
16. [Molecular identification of bovine enteric calciviruses in Venezuela]
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ANA ALCALA, Ma, Hidalgo, Obando C, Vizzi E, Liprandi F, and Je, Ludert
17. Distribution of VP7 serotypes and VP4 genotypes among rotavirus strains recovered from Italian children with diarrhea
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Antonio Cascio, Esmeralda Vizzi, R. Di Stefano, Serenella Arista, Donatella Ferraro, ARISTA S, VIZZI E, FERRARO D, A. CASCIO, and DI STEFANO R
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Diarrhea ,Serotype ,medicine.medical_specialty ,Genotype ,Reoviridae ,Biology ,medicine.disease_cause ,Polymerase Chain Reaction ,Rotavirus Infections ,law.invention ,Capsid ,Medical microbiology ,law ,Virology ,Rotavirus ,medicine ,Humans ,UNIQUE VP4 ,Serotyping ,Child ,Antigens, Viral ,Polymerase chain reaction ,Molecular epidemiology ,General Medicine ,POLYMERASE CHAIN-REACTION ,biology.organism_classification ,Gastroenteritis ,rotavirus ,Italy ,Child, Preschool ,RNA, Viral ,Capsid Proteins ,medicine.symptom - Abstract
108 rotavirus strains obtained from children with diarrhea hospitalized in Palermo, Italy, in the years 1990-1994, were examined by seminested PCR to study the relative frequency and distribution of the four most common alleles of the gene 4. Such strains were selected from 344 human rotavirus strains recovered in palermo during those years after characterization by electropherotyping, subgrouping and G serotyping. One hundred and seven of the 108 strains could be classified into P types, the P[8], G1 (38.3%) and the P[8], G4 (52.3%) types being predominant. The unique strain whose P genotype could not be identified showed an unusual combination of long migration electrophoretic pattern and subgroup I specificity.
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- 1997
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18. Identification of picobirnavirus from faeces of Italian children suffering from acute diarrhea
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Serenella Arista, Antonio Cascio, Michele Bosco, Donatella Ferraro, Anna Giammanco, Esmeralda Vizzi, A. CASCIO, BOSCO M, VIZZI E, GIAMMANCO A, FERRARO D, and ARISTA S
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Diarrhea ,Male ,Acute diarrhea ,Epidemiology ,Picobirnavirus ,Microbiology ,Feces ,Picobirnavirus, Gastroenteritis, PAGE ,Humans ,Medicine ,Child ,Polyacrylamide gel electrophoresis ,Gel electrophoresis ,biology ,business.industry ,Brief Report ,biology.organism_classification ,Gastroenteritis ,PAGE ,Italy ,Virus Diseases ,RNA, Viral ,Electrophoresis, Polyacrylamide Gel ,Female ,Viral disease ,medicine.symptom ,business - Abstract
Polyacrylamide gel electrophoresis of nucleic acid extracted from stool samples of diarrhoeic children revealed in 3 out of 690 (0.43 %) specimens two electrophoretic bands with a migration pattern characteristic of picobirnavirus ds-RNA. In none of the 92 control children were similar bands detected. No other potential enteric pathogens were found in the patients with picobirnavirus infection.
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- 1996
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19. High incidence of G9P[8] rotavirus infections in Italian children during the winter season 1999-2000
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E Di Rosa, Antonio Cascio, M. C. Migliore, Serenella Arista, Esmeralda Vizzi, ARISTA S, VIZZI E, MIGLIORE MC, DI ROSA E, and A. CASCIO
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Serotype ,Pediatrics ,medicine.medical_specialty ,biology ,Epidemiology ,business.industry ,Incidence (epidemiology) ,diarrhea ,Reoviridae ,biology.organism_classification ,medicine.disease_cause ,Virology ,Diarrhea ,rotavirus ,El Niño ,Italy ,Rotavirus ,Medicine ,gastroenteriti ,medicine.symptom ,business ,Feces - Abstract
We report a significant high incidence of infection with G9P[8] rotavirus in Italian children during the winter epidemic season 1999-2000. The study was carried out on 439 children < 4 years hospitalized with acute diarrhea in Palermo. G9P[8] strains constituted 19% of all rotavirus identified and were not associated with more severe forms of gastroenteritis.
- Published
- 2003
20. Rotavirus gastroenteritis in Italian children: can severity of symptoms be related to the infecting virus?
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Esmeralda Vizzi, Serenella Arista, Cristina Alaimo, Antonio Cascio, A. CASCIO, VIZZI E, ALAIMO C, and ARISTA S
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Microbiology (medical) ,Diarrhea ,Male ,Rotavirus ,medicine.medical_specialty ,Time Factors ,Fever ,Vomiting ,Reoviridae ,medicine.disease_cause ,Severity of Illness Index ,Virus ,Rotavirus Infections ,Child, Rotavirus ,rotavirus ,gastroenteritis ,Epidemiology ,medicine ,Humans ,Typing ,Child ,biology ,business.industry ,Infant, Newborn ,Infant ,biology.organism_classification ,Virology ,Gastroenteritis ,Infectious Diseases ,Italy ,Child, Preschool ,Immunology ,Female ,Viral disease ,medicine.symptom ,business - Abstract
The aim of our study was to determine whether the severity of rotavirus gastroenteritis may be related to the different characteristics of infecting viral strains. The severity of clinical symptoms in 401 children with acute rotavirus gastroenteritis was assessed using a scoring system for frequency and duration of vomiting, diarrhea, and fever, as well as the patients' requirements for intravenous rehydration. Rotavirus strains were characterized by determining the electropherotype of their double-stranded RNA, the G type and subgroup by a panel of monoclonal antibodies, and the P type by reverse transcription-polymerase chain reaction. Strains with a short electropherotype, G2P[4] type, and subgroup I were associated with more-severe gastroenteritis and affected children older than those infected with strains with a long electropherotype, G1P[8] or G4P[8] type, and subgroup II. Minor differences in clinical symptoms were also detected in children infected with different long electropherotypes and with G1P[8] and G4P[8] specificities.
- Published
- 2000
21. Identification of human rotavirus strains with the P[14] genotype by PCR
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Cristina Alaimo, Daniela Palermo, Serenella Arista, Antonio Cascio, Esmeralda Vizzi, ARISTA S, VIZZI E, ALAIMO C, PALERMO D, and A. CASCIO
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Microbiology (medical) ,Genetics ,Rotavirus ,Reoviridae ,virus diseases ,Genome, Viral ,Biology ,medicine.disease_cause ,biology.organism_classification ,Virology ,Polymerase Chain Reaction ,Virus ,law.invention ,Capsid ,law ,Genotype ,medicine ,Humans ,Typing ,Polymerase chain reaction ,Southern blot ,ROTAVIRUS, GASTROENTERITIS - Abstract
A seminested PCR typing assay has been extended to identify rotavirus strains with the P[14] genotype. The specificity of the method was confirmed by Southern hybridization and by restriction analysis with the enzyme Alu I. One out of four human rotavirus (HRV) strains with unusual subgroup-electropherotype linkage but none out of 50 HRV strains with usual linkage was typed as P[14].
- Published
- 1999
22. Detection of IgM antibodies specific for measles virus by capture and indirect enzyme immunoassays
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Antonio Cascio, Esmeralda Vizzi, Donatella Ferraro, Serenella Arista, R. Di Stefano, ARISTA S, FERRARO D, A. CASCIO, VIZZI E, and DI STEFANO R
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Adult ,Time Factors ,Anti-nuclear antibody ,Paramyxoviridae ,Adolescent ,Immunology ,Enzyme-Linked Immunosorbent Assay ,Antibodies, Viral ,Measles ,Sensitivity and Specificity ,Serology ,Disease Outbreaks ,Measles virus ,Immunoenzyme Techniques ,Morbillivirus ,Antibody Specificity ,Virology ,Chlorocebus aethiops ,medicine ,Animals ,Humans ,Child ,Vero Cells ,biology ,medicine.diagnostic_test ,Infant ,biology.organism_classification ,medicine.disease ,Rash ,Immunoglobulin M ,Evaluation Studies as Topic ,Immunoassay ,Child, Preschool ,Reagent Kits, Diagnostic ,medicine.symptom ,Capture EIA, IgM, Indirect EIA - Abstract
Summary During a measles outbreak, 112 serum specimens from 88 hospitalized patients were received in our laboratory for investigation of a morbilliform rash. These specimens (88 acute- and 24 convalescent-phase) were tested for the presence of measles-specific IgM antibodies by a capture EIA (enzyme immunoassay) using peroxidase-conjugated measles virus antigens and by an indirect EIA. Commercially available indirect EIA kits for measles-specific IgM antibodies were also used and compared with our homemade EIAs. Specificity studies included a collection of serum specimens containing rheumatoid factor, antinuclear antibodies or IgM antibodies specific to other viruses, and sera from blood donors and healthy children. Sensitivity of capture EIA and indirect EIA to detect measles IgM was 91.8 and 90.3%, respectively, and specificity was 98.2% for both tests. Specific IgM antibodies were detected in 70.5% of serum specimens at the first day after rash onset and were present for a month following the rash. Among the commercial measles IgM detection assays, EIA “Behring” was found to be a valid alternative for detection of measles virus-specific IgM.
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- 1995
23. Detection and diversity of gastrointestinal viruses in wastewater from Caracas, Venezuela, 2021-2022.
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Zamora-Figueroa A, Rosales RE, Fernández R, Ramírez V, Bastardo M, Farías A, and Vizzi E
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- Humans, Wastewater, Venezuela epidemiology, Pandemics, Antigens, Viral, Adenoviridae, Feces, Rotavirus, Gastroenteritis diagnosis, Enterovirus, Picornaviridae, Enterovirus Infections epidemiology
- Abstract
Gastrointestinal viruses (GIV) are an important cause of childhood morbidity and mortality, particularly in developing countries. Their epidemiological impact in Venezuela during the COVID-19 pandemic remains unclear. GIV can also be detected in domestic sewage. Ninety-one wastewater samples from urban areas of Caracas collected over 12 months and concentrated by polyethylene-glycol-precipitation, were analyzed by multiplex reverse-transcription-PCR for rotavirus/calicivirus/astrovirus and enterovirus/klassevirus/cosavirus, and monoplex-PCR for adenovirus and Aichi virus. The overall frequency of virus detection was 46.2%, fluctuating over months, and peaking in the rainy season. Adenoviruses circulated throughout the year, especially type F41, and predominated (52.7%) over caliciviruses (29.1%) that peaked in the rainy months, rotaviruses (9.1%), cosaviruses (5.5%), astroviruses and enteroviruses (1.8%). Aichi-virus and klassevirus were absent. Rotavirus G9/G12, and P[4]/P[8]/P[14] predominated. The occurrence of GIV in wastewater reflects transmission within the population of Caracas and the persistence of a potential public health risk that needs to be adequately monitored., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2024
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24. Molecular characterization of human adenovirus causing infantile acute gastroenteritis in Venezuela before and after rotavirus vaccine implementation.
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Blanco R, Alcalá AC, Fernández R, Ramírez V, Rosales RE, Páez MG, Alemán H, González R, Zerpa J, Maldonado AJ, and Vizzi E
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- Female, Humans, Infant, Feces, Phylogeny, Venezuela epidemiology, Male, Adenoviruses, Human genetics, Gastroenteritis epidemiology, Rotavirus genetics, Rotavirus Vaccines
- Abstract
Human adenoviruses (HAdV) of species F are commonly involved in pediatric acute gastroenteritis (AGE). The real impact on Venezuelan health is unknown. To investigate the prevalence and molecular diversity of HAdV in Venezuela, 630 fecal samples collected from children with AGE in 3 cities, from 2001 to 2013, were tested by PCR. Species F and types F40/41 were identified by REA. HAdV was detected in 123 cases (19.5%), most from outpatient females under 24 months old. A progressive and substantial increase in the detection rate was observed over time, significantly higher in rotavirus vaccinated than unvaccinated children (28.4% vs. 9.5%, P = 0.00019). Phylogenetic analysis of 28 randomly selected genomes showed high similarity among HAdV-F40/41 and those worldwide. HAdV-F of type 41 prevailed (79.8%) and clustered into 2 intratypic major clades. The significant involvement of HAdV-F41 in AGE suggests the importance of actively monitoring viral agents other than rotavirus, especially after vaccine introduction., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Published by Elsevier Inc.)
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- 2023
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25. Introduction and rapid dissemination of SARS-CoV-2 Gamma Variant of Concern in Venezuela.
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Jaspe RC, Loureiro CL, Sulbaran Y, Moros ZC, D'Angelo P, Rodríguez L, Zambrano JL, Hidalgo M, Vizzi E, Alarcón V, Aguilar M, Garzaro DJ, Rangel HR, and Pujol FH
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- Genome, Viral, Humans, Mutation, Polymerase Chain Reaction, Prevalence, Reinfection virology, SARS-CoV-2 isolation & purification, SARS-CoV-2 pathogenicity, Venezuela epidemiology, Whole Genome Sequencing, COVID-19 epidemiology, COVID-19 virology, Phylogeny, SARS-CoV-2 genetics
- Abstract
In less than two years since SARS-CoV-2 emerged, the new coronavirus responsible for COVID-19, has accumulated a great number of mutations. Many of these mutations are located in the Spike protein and some of them confer to the virus higher transmissibility or partial resistance to antibody mediated neutralization. Viral variants with such confirmed abilities are designated by WHO as Variants of Concern (VOCs). The aim of this study was to monitor the introduction of variants and VOCs in Venezuela. A small fragment of the viral genome was sequenced for the detection of the most relevant mutations found in VOCs. This approach allowed the detection of Gamma VOC. Its presence was confirmed by complete genome sequencing. The Gamma VOC was detected in Venezuela since January 2021, and in March 2021 was predominant in the East and Central side of the country, representing more than 95% of cases sequenced in all the country in April-May 2021. In addition to the Gamma VOC, other isolates carrying the mutation E484K were also detected. The frequency of this mutation has been increasing worldwide, as shown in a survey of sequences carrying E484K mutation in GISAID, and was detected in Venezuela in many probable cases of reinfection. Complete genome sequencing of these cases allowed us to identify E484K mutation in association with Gamma VOC and other lineages. In conclusion, the strategy adopted in this study is suitable for genomic surveillance of variants for countries lacking robust genome sequencing capacities. In the period studied, Gamma VOC seems to have rapidly become the dominant variant throughout the country., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2021
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26. HUMAN COSAVIRUS INFECTION IN HIV SUBJECTS WITH DIARRHOEA: PERSISTENT DETECTION ASSOCIATED WITH FATAL OUTCOME.
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Vizzi E, Fernández R, Angulo LA, Blanco R, and Pérez C
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- Diarrhea epidemiology, Feces, Humans, Infant, Male, Phylogeny, HIV Infections complications, Picornaviridae, Picornaviridae Infections
- Abstract
Background: Human cosavirus (HCoSV) is a new member of the Picornaviridae family, geographically widespread among humans. It has been suggested as a causative agent of acute gastroenteritis, but its pathogenicity is not currently certain. In HIV-infected subjects, diarrhoea is one of the most frequent gastrointestinal manifestations, whose aetiology remains often unexplained., Objectives: To identify the cause of viral diarrhoea among HIV infected patients by molecular assays., Study Design: A total of 143 stool samples from HIV subjects with and without diarrhoea, were screened for conventional enteric viruses (rotavirus, adenovirus, norovirus and astrovirus) by molecular assays. The presence of HCoSV genome was investigated by nested RT-PCR for the 5'UTR region. Positive samples were further characterized by sequencing and phylogenetic analysis., Results: Enteric viruses were more frequently found in diarrhoea cases (9/82) than controls (0/61) (p=0.007). HCoSV was detected in five (3.5%) of the subjects affected by diarrhoea. Phylogenetic analysis revealed the predominance of the HCoSV species D. One patient suffered a persistent cosavirus infection with a same strain and after eight months he had a fatal outcome. No other pathogens could be detected., Conclusions: The results suggest a role of non-conventional enteric viruses, as HCoSV, as a potential opportunistic agent causing persistent infection and deterioration of the clinical conditions in HIV-infected patients. Screening procedures and monitoring including such viruses would be helpful in the clinical management of such patients., (Copyright © 2021 Elsevier B.V. All rights reserved.)
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- 2021
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27. Molecular detection of human enteric viruses circulating among children with acute gastroenteritis in Valencia, Venezuela, before rotavirus vaccine implementation.
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Alcalá AC, Pérez K, Blanco R, González R, Ludert JE, Liprandi F, and Vizzi E
- Abstract
Background: The role of rotavirus as main etiologic agent of diarrhea has been well documented worldwide, including in Venezuela. However, information about the prevalence of gastrointestinal viruses such as calicivirus, adenovirus and astrovirus is limited and the contribution of other agents as Aichi virus and klassevirus is largely unknown. To explore the etiological spectrum of diarrhea associated with agents other than rotaviruses, 227 stool samples from children under 5 years old with acute gastroenteritis, collected in Valencia (Venezuela) from 2001 to 2005, and previously tested as rotavirus-negative, were analyzed for caliciviruses, adenoviruses, astroviruses, Aichi viruses, klasseviruses, picobirnaviruses and enteroviruses by specific RT-PCRs., Results: At least one viral agent was detected in 134 (59%) of the samples analyzed, mainly from children under 24 months of age and most of them belonging to the lowest socioeconomic status. Overall, enterovirus was identified as the most common viral agent (37.9%), followed by calicivirus (23.3%), adenovirus (11.5%), astrovirus (3.5%), klassevirus (1.3%) and Aichi virus (0.4%), while no picobirnavirus was detected. Klasseviruses were found during 2004 and 2005 and Aichi viruses only in 2005, indicating their circulation in Venezuela; meanwhile, the rest of the viruses were detected during the whole study period. Coinfections with two or more viruses were found in 39 (29.1%) of the infected children, most under 24 months of age. Adenovirus was involved as the coinfecting agent in at least 46.9% of the cases, but no differences concerning socio-demographic variables were observed between the coinfected and the single infected children., Conclusions: The results show that various enteric viruses, including enteroviruses, caliciviruses and adenoviruses, accounted for a significant proportion of infantile diarrhea cases in Venezuela before rotavirus vaccine implementation. In addition, emerging viruses as Aichi virus and klassevirus were found, indicating the need to continue monitoring their spreading into the communities. Efforts are needed to develop more accurate methods to identify the major causes of diarrhea and to provide tools for more effective preventive measures.
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- 2018
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28. Human rotavirus strains circulating in Venezuela after vaccine introduction: predominance of G2P[4] and reemergence of G1P[8].
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Vizzi E, Piñeros OA, Oropeza MD, Naranjo L, Suárez JA, Fernández R, Zambrano JL, Celis A, and Liprandi F
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- Female, Genotyping Techniques, Humans, Infant, Male, Molecular Epidemiology, Multiplex Polymerase Chain Reaction, Prevalence, Reverse Transcriptase Polymerase Chain Reaction, Rotavirus isolation & purification, Rotavirus Infections prevention & control, Rotavirus Vaccines administration & dosage, Venezuela epidemiology, Genotype, Rotavirus classification, Rotavirus genetics, Rotavirus Infections epidemiology, Rotavirus Infections virology, Rotavirus Vaccines immunology
- Abstract
Background: Rotavirus (RV) is the most common cause of severe childhood diarrhea worldwide. Despite Venezuela was among the first developing countries to introduce RV vaccines into their national immunization schedules, RV is still contributing to the burden of diarrhea. Concerns exist about the selective pressure that RV vaccines could exert on the predominant types and/or emergence of new strains., Results: To assess the impact of RV vaccines on the genotype distribution 1 year after the vaccination was implemented, a total of 912 fecal specimens, collected from children with acute gastroenteritis in Caracas from February 2007 to April 2008, were screened, of which 169 (18.5%) were confirmed to be RV positive by PAGE. Rotavirus-associated diarrhea occurred all year-round, although prevailed during the coolest and driest months among unvaccinated children under 24 months old. Of 165 RV strains genotyped for G (VP7) and P (VP4) by seminested multiplex RT-PCR, 77 (46.7%) were G2P[4] and 63 (38.2%) G1P[8]. G9P[8], G3P[8] and G2P[6] were found in a lower proportion (7.3%). Remarkable was also the detection of <5% of uncommon combinations (G8P[14], G8P[4], G1P[4] and G4P[4]) and 3.6% of mixed infections. A changing pattern of G/P-type distribution was observed during the season studied, with complete predominance of G2P[4] from February to June 2007 followed by its gradual decline and the reemergence of G1P[8], predominant since January 2008. Phylogenetic analysis of VP7 and VP4 genes revealed a high similarity among G2P[4] and global strains belonging to G2-II and P[4]-V lineages. The amino acid substitution 96D → N, related with reemergence of the G2 genotype elsewhere, was observed. The G1P[8] strains from Caracas were grouped into the lineages G1-I and P[8]-III, along with geographically remote G1P[8] rotaviruses, but they were rather distant from Rotarix
® vaccine and pre-vaccine strains. Unique amino acid substitutions observed on neutralization domains of the VP7 sequence from Venezuelan post-vaccine G1P[8] could have conditioned their re-emergence and a more efficient dissemination into susceptible population., Conclusions: The results suggest that natural fluctuations of genotypes in combination with forces driving the genetic evolution could determine the spread of novel strains, whose long-term effect on the efficacy of available vaccines should be determined.- Published
- 2017
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29. Prevalence and molecular characterization of G6PD deficiency in two Plasmodium vivax endemic areas in Venezuela: predominance of the African A-(202A/376G) variant.
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Vizzi E, Bastidas G, Hidalgo M, Colman L, and Pérez HA
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- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, DNA Mutational Analysis, Female, Glucosephosphate Dehydrogenase Deficiency genetics, Humans, Infant, Male, Middle Aged, Venezuela epidemiology, Young Adult, Malaria, Vivax epidemiology, Malaria, Vivax genetics, Plasmodium vivax genetics, Plasmodium vivax pathogenicity
- Abstract
Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency causes acute haemolytic anaemia triggered by oxidative drugs such as primaquine (PQ), used for Plasmodium vivax malaria radical cure. However, in many endemic areas of vivax malaria, patients are treated with PQ without any evaluation of their G6PD status., Methods: G6PD deficiency and its genetic heterogeneity were evaluated in northeastern and southeastern areas from Venezuela, Cajigal (Sucre state) and Sifontes (Bolívar state) municipalities, respectively. Blood samples from 664 randomly recruited unrelated individuals were screened for G6PD activity by a quantitative method. Mutation analysis for exons 4-8 of G6PD gen was performed on DNA isolated from G6PD-deficient (G6PDd) subjects through PCR-RFLP and direct DNA sequencing., Results: Quantitative biochemical characterization revealed that overall 24 (3.6%) subjects were G6PDd (average G6PD enzyme activity 4.5 ± 1.2 U/g Hb, moderately deficient, class III), while DNA analysis showed one or two mutated alleles in 19 of them (79.2%). The G6PD A-(202A/376G) variant was the only detected in 17 (70.8%) individuals, 13 of them hemizygous males and four heterozygous females. Two males carried only the 376A → G mutation. No other mutation was found in the analysed exons., Conclusions: The G6PDd prevalence was as low as that one shown by nearby countries. This study contributes to the knowledge of the genetic background of Venezuelan population, especially of those living in malaria-endemic areas. Despite the high degree of genetic mixing described for Venezuelan population, a net predominance of the mild African G6PD A-(202A/376G) variant was observed among G6PDd subjects, suggesting a significant flow of G6PD genes from Africa to Americas, almost certainly introduced through African and/or Spanish immigrants during and after the colonization. The data suggest that 1:27 individuals of the studied population could be G6PDd and therefore at risk of haemolysis under precipitating factors. Information about PQ effect on G6PDd individuals carrying mild variant is limited, but since the regimen of 45 mg weekly dose for prevention of malaria relapse does not seem to be causing clinically significant haemolysis in people having the G6PD A-variant, a reasoned weighing of risk-benefit for its use in Venezuela should be done, when implementing public health strategies of control and elimination.
- Published
- 2016
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30. [Selection of heparin-sensitive dengue virus variants in BHK-21 cells].
- Author
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Celis A, Moros Z, Gerder M, Pagano F, Vizzi E, and Liprandi F
- Subjects
- Aedes cytology, Animals, Cell Line, Chlorocebus aethiops, Cricetinae, Dengue Virus growth & development, Kidney cytology, Mesocricetus, Models, Molecular, Mutation, Mutation, Missense, Protein Binding, Protein Conformation, RNA, Viral genetics, Sequence Analysis, RNA, Vero Cells, Viral Envelope Proteins chemistry, Viral Envelope Proteins physiology, Viral Plaque Assay, Virus Cultivation, Virus Replication, Dengue Virus drug effects, Heparin pharmacology, Selection, Genetic, Viral Envelope Proteins genetics
- Abstract
Several studies have shown that adaptation of various viruses to grow in certain cell lines of vertebrates, leads to the selection of virus variants that bind heparan sulfate (HS) with high affinity. In this study we investigated the susceptibility of strains of dengue virus (DENV) to oversulfated heparin an analogue of HS after passages in BHK-21 cells. Field isolates of the four serotypes of DENV with a limited number of passes in mosquito cells C6/36HT were serially passaged eight times in BHK-21 cells. The adaptation of the DENV to the cell culture selected viral variants with an increased replicative capacity in BHK-21 cells and an increased susceptibility to heparin compared with the original not adapted strains, with a more significant inhibition of the infectivity in DENV-2 and DENV-4.The E protein of the adapted strains showed changes in the amino acid sequence, particularly at the position K204R to DENV-1, N67K to DENV-2, K308R and V452A for DENV-3 and E327G to DENV-4. These substitutions implicated a gain of basic residues that increased the net positive charge of the protein. These results suggest that adaptation of DENV strains to BHK-21 cells implies changes in the envelope protein, changes associated to the protein reactivity with heparin, the inhibitory effectiveness of this compound varying depending on the viral strain. In addition, these results suggest that the HS can play an important role in the infectivity of the DENV strains adapted to vertebrate cell culture, but not in the infectivity of non-adapted DENV isolates.
- Published
- 2014
31. [Enteropathogens responsible for gastrointestinal disorders in HIV patients].
- Author
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Vizzi E and Angulo Medina LA
- Subjects
- AIDS-Related Opportunistic Infections microbiology, AIDS-Related Opportunistic Infections parasitology, AIDS-Related Opportunistic Infections virology, Bacterial Infections complications, Bacterial Infections microbiology, CD4 Lymphocyte Count, Diarrhea microbiology, Diarrhea parasitology, Diarrhea virology, Gastrointestinal Diseases complications, Gastrointestinal Diseases diagnosis, Humans, Immunocompromised Host, Intestinal Diseases, Parasitic complications, Intestinal Diseases, Parasitic parasitology, Mycoses complications, Mycoses microbiology, Virus Diseases complications, Virus Diseases microbiology, Gastrointestinal Diseases microbiology, Gastrointestinal Diseases parasitology, Gastrointestinal Diseases virology, HIV Infections complications
- Abstract
Gastrointestinal disorders or GID are debilitating conditions common in individuals infected by the human immunodeficiency virus (HIV), capable of leading to death. Numerous etiological agents and pathophysiological mechanisms have been involved in this status. Although the use of highly active antiretroviral therapy (HAART) in many countries has greatly reduced the prevalence of gastrointestinal infections, enteric pathogens such as bacteria, parasites, fungi and viruses may still act as opportunist agents in these patients. Cytomegalovirus, adenovirus, calicivirus, astrovirus, rotavirus, enterovirus, picobirnavirus and some more recently described, like bocavirus and Aichi virus, have been detected in HIV patients. However, except for cytomegalovirus, which is an established etiological agent of GID in these patients, the role of the other viruses remains unclear. Several species of Cryptosporidium, microsporidia, Salmonella, atipical mycobacteria and Campylobacter jejuni, have also been recognized as important causes of GID in HIV patients. The progressive incorporation of increasingly sensitive immunological and molecular assays for antigen, antibody and pathogens detection from faeces, has improved the diagnosis of diarrhea and contributed to clarify the etiological significance of some microorganisms in immunocompetent patients. In Venezuela, some information is available about the prevalence of enteric pathogens in immunocompromised patients infected with HIV. The identification of the etiologic agent responsible for this condition may be useful for the management and treatment of these patients, for whom viral enteritis is a disease, which reduces their quality of life and causes a high public health spending.
- Published
- 2013
32. Rotavirus infection of cells in culture induces activation of RhoA and changes in the actin and tubulin cytoskeleton.
- Author
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Zambrano JL, Sorondo O, Alcala A, Vizzi E, Diaz Y, Ruiz MC, Michelangeli F, Liprandi F, and Ludert JE
- Subjects
- Actin Cytoskeleton drug effects, Animals, Antibodies, Monoclonal immunology, Antibodies, Neutralizing immunology, Calcium metabolism, Cells, Cultured, Chelating Agents pharmacology, Chlorocebus aethiops, Enzyme Activation drug effects, Gene Silencing drug effects, Glycoproteins metabolism, Microtubules drug effects, Microtubules metabolism, Models, Biological, Phosphorylation drug effects, RNA, Small Interfering metabolism, Rotavirus drug effects, Rotavirus physiology, Stress Fibers drug effects, Stress Fibers metabolism, Time Factors, Toxins, Biological metabolism, Viral Nonstructural Proteins metabolism, Virion immunology, Actin Cytoskeleton metabolism, Actins metabolism, Rotavirus Infections enzymology, Tubulin metabolism, rhoA GTP-Binding Protein metabolism
- Abstract
Rotavirus infection induces an increase in [Ca(2+)](cyto), which in turn may affect the distribution of the cytoskeleton proteins in the infected cell. Changes in microfilaments, including the formation of stress fibers, were observed starting at 0.5 h.p.i. using fluorescent phalloidin. Western blot analysis indicated that RhoA is activated between 0.5 and 1 h.p.i. Neither the phosphorylation of RhoA nor the formation of stress fibers were observed in cells infected with virions pre-treated with an anti-VP5* non-neutralizing mAb, suggesting that RhoA activation is stimulated by the interaction of the virus with integrins forming the cell receptor complex. In addition, the structure of the tubulin cytoskeleton was also studied. Alterations of the microtubules were evident starting at 3 h.p.i. and by 7 h.p.i. when microtubules were markedly displaced toward the periphery of the cell cytoplasm. Loading of rotavirus-infected cells with either a Ca(2+) chelator (BAPTA) or transfection with siRNAs to silence NSP4, reversed the changes observed in both the microfilaments and microtubules distribution, but not the appearance of stress fibers. These results indicate that alterations in the distribution of actin microfilaments are initiated early during infection by the activation of RhoA, and that latter changes in the Ca(2+) homeostasis promoted by NSP4 during infection may be responsible for other alterations in the actin and tubulin cytoskeleton.
- Published
- 2012
- Full Text
- View/download PDF
33. Genotyping of human rotaviruses circulating among children with diarrhea in Valencia, Venezuela.
- Author
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Vizzi E, Piñeros O, González GG, Zambrano JL, Ludert JE, and Liprandi F
- Subjects
- Child, Preschool, Dehydration epidemiology, Diarrhea complications, Diarrhea epidemiology, Diarrhea pathology, Diarrhea virology, Enzyme-Linked Immunosorbent Assay, Feces virology, Female, Gastroenteritis complications, Gastroenteritis epidemiology, Gastroenteritis pathology, Gastroenteritis virology, Genotype, Humans, Infant, Male, Molecular Epidemiology, RNA, Viral genetics, Reverse Transcriptase Polymerase Chain Reaction, Rotavirus isolation & purification, Sequence Analysis, DNA, Venezuela epidemiology, Rotavirus classification, Rotavirus genetics, Rotavirus Infections epidemiology, Rotavirus Infections virology
- Abstract
Rotavirus infection is the most common cause of severe gastroenteritis during childhood worldwide, especially in developing countries. Two rotavirus vaccines are available for childhood immunization programs. Evaluation of the vaccine performance will benefit from knowledge of the epidemiological features of rotavirus infection in regional settings. Limited information on the molecular characteristics of the rotavirus types circulating in Venezuela is available. Eighty seven (89.7%) of the 97 ELISA rotavirus positive stool samples collected from children with diarrhea aged <5 years during 2003 in Valencia (Carabobo State), were G-, P- and NSP4-genotyped by RT-PCR and/or automated sequencing. Four common combinations, G3P[8]/NSP4-E1, G2P[4]/NSP4-E2, G9P[8]/NSP4-E1, and G1P[8]/NSP4-E1 were responsible for 50.6%, 35.6%, 5.7%, and 1.1%, respectively of cases of rotavirus diarrhea, most of them (66%) in children ≤12 months. One uncommon G8P[14]/NSP4-E2 strain was also detected. Temporal fluctuation of genotype distribution occurred, but no differences by age, diarrhea severity score, sex, treatment type or patient medical attention were observed, except for the G3P[8]/NSP4-E1, associated with a more severe dehydration than any other type (P < 0.01). The results confirm the broad diversity among rotavirus strains circulating in Venezuela prior to vaccine implementation, showing the predominance of G3, significant proportion of G2 and moderate circulation of G9 strains. Epidemiological surveillance is needed to detect the emergence of new genotypes that could escape protection induced by vaccination., (Copyright © 2011 Wiley Periodicals, Inc.)
- Published
- 2011
- Full Text
- View/download PDF
34. Seroepidemiology of porcine enteric sapovirus in pig farms in Venezuela.
- Author
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Alcalá AC, Rodríguez-Díaz J, de Rolo M, Vizzi E, Buesa J, Liprandi F, and Ludert JE
- Subjects
- Age Factors, Animals, Baculoviridae genetics, Capsid Proteins genetics, Capsid Proteins immunology, Recombinant Proteins immunology, Recombinant Proteins isolation & purification, Sapovirus isolation & purification, Seroepidemiologic Studies, Virion isolation & purification, Antibodies, Viral blood, Sapovirus chemistry, Swine virology
- Abstract
Porcine enteric sapovirus (PES) has been shown to cause diarrhea under experimental conditions in gnotobiotic piglets. However, the role of PES as enteric pathogens in porcine farms remains unclear. To further understand the PES-host interactions under field conditions, a serological survey was carried out. To this end the capsid gene of a PES isolate was cloned in the baculovirus expression system and an ELISA was developed based on virus-like particles from the baculovirus-expressed PES capsid protein. A total of 85 serum samples collected from pigs ranging from 8 weeks to over 54 weeks of age were analyzed. An overall seroprevalence to PESs of 62% was found, with significant differences (p<0.05) found between ages. Pigs younger than 10 weeks old and older than 12 weeks old showed high seroprevalences (70-100%), while pigs aged 10-12 weeks showed no detectable serum antibodies levels. Our results suggest that PES infections are common in pigs and that passively acquired maternal antibodies are soon replaced by actively acquired antibodies, whose titers increase gradually with age and that probably are maintained during lifetime., ((c) 2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
35. Molecular detection and characterization of Aichi viruses in sewage-polluted waters of Venezuela.
- Author
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Alcalá A, Vizzi E, Rodríguez-Díaz J, Zambrano JL, Betancourt W, and Liprandi F
- Subjects
- Cluster Analysis, Genotype, Molecular Sequence Data, RNA, Viral genetics, Sequence Analysis, DNA, Sequence Homology, Urban Population, Venezuela, Kobuvirus classification, Kobuvirus isolation & purification, Sewage virology, Water Microbiology
- Abstract
The circulation of Aichi virus in a major urban area was demonstrated using molecular detection with samples recovered from a major river polluted with sewage discharges in Caracas, Venezuela. Five out of 11 water samples studied were positive, being classified by phylogenetic analysis as genotype B. Analysis of sewage waters appears to be a useful methodology to uncover the presence of a hitherto undetected fecal pathogen in a given geographical area.
- Published
- 2010
- Full Text
- View/download PDF
36. Silencing of rotavirus NSP4 or VP7 expression reduces alterations in Ca2+ homeostasis induced by infection of cultured cells.
- Author
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Zambrano JL, Díaz Y, Peña F, Vizzi E, Ruiz MC, Michelangeli F, Liprandi F, and Ludert JE
- Subjects
- Animals, Antibodies, Monoclonal metabolism, Antigens, Viral genetics, COS Cells, Calcium Radioisotopes metabolism, Capsid Proteins genetics, Chlorocebus aethiops, Fluorescent Antibody Technique, Indirect, Glycoproteins genetics, Homeostasis, RNA, Small Interfering metabolism, Toxins, Biological genetics, Transfection, Viral Nonstructural Proteins genetics, Antigens, Viral metabolism, Calcium metabolism, Capsid Proteins metabolism, Gene Silencing, Glycoproteins metabolism, Rotavirus physiology, Toxins, Biological metabolism, Viral Nonstructural Proteins metabolism
- Abstract
Rotavirus infection of cells in culture induces major changes in Ca(2+) homeostasis. These changes include increases in plasma membrane Ca(2+) permeability, cytosolic Ca(2+) concentration, and total cell Ca(2+) content and a reduction in the amount of Ca(2+) released from intracellular pools sensitive to agonists. Various lines of evidence suggest that the nonstructural glycoprotein NSP4 and possibly the major outer capsid glycoprotein VP7 are responsible for these effects. In order to evaluate the functional roles of NSP4 and other rotavirus proteins in the changes in Ca(2+) homeostasis observed in infected cells, the expressions of NSP4, VP7, and VP4 were silenced using the short interfering RNA (siRNA) technique. The transfection of specific siRNAs resulted in a strong and specific reduction of the expression of NSP4, VP7, and VP4 and decreased the yield of new viral progeny by more than 90%. Using fura-2 loaded cells, we observed that knocking down the expression of NSP4 totally prevented the increase in Ca(2+) permeability of the plasma membrane and cytosolic Ca(2+) concentration measured in infected cells. A reduction in the levels of VP7 expression partially reduced the effect of infection on plasma membrane Ca(2+) permeability and Ca(2+) pools released by agonist (ATP). In addition, the increase of total Ca(2+) content (as measured by (45)Ca(2+) uptake) observed in infected cells was reduced to the levels in mock-infected cells when NSP4 and VP7 were silenced. Finally, when the expression of VP4 was silenced, none of the disturbances of Ca(2+) homeostasis caused by rotaviruses in infected cells were affected. These data altogether indicate that NSP4 is the main protein responsible for the changes in Ca(2+) homeostasis observed in rotavirus-infected cultured cells. Nevertheless, VP7 may contribute to these effects.
- Published
- 2008
- Full Text
- View/download PDF
37. Mutation analysis of the HFE gene associated with hereditary hemochromatosis in a Venezuelan sample.
- Author
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Vizzi E, Loureiro CL, Gerder M, de las Nieves Garcia-Casal M, Rodríguez-Larralde A, Gerace L, Ludert JE, Liprandi F, and Pujol FH
- Subjects
- Adolescent, Adult, Alleles, Child, DNA Mutational Analysis, Female, Ferritins blood, Gene Frequency, Hemochromatosis blood, Hemochromatosis Protein, Heterozygote, Histocompatibility Antigens Class I metabolism, Humans, Iron blood, Male, Membrane Proteins metabolism, Middle Aged, Random Allocation, Venezuela, Amino Acid Substitution, Hemochromatosis genetics, Histocompatibility Antigens Class I genetics, Membrane Proteins genetics, Point Mutation, Polymorphism, Restriction Fragment Length
- Abstract
The frequency of the C282Y, H63D and S65C alleles of the HFE gene was determined in a sample of the Venezuelan population. Two new sets of primers were tested for amplifying the regions mapping these mutations, and genotyping was performed by restriction fragment length polymorphism (RFLP). DNA sequencing was used to validate the RFLP analysis. Serum ferritin levels were also determined. Two hundred and fourteen individuals were tested, extracting DNA from whole blood cells (n=177) or from serum (n=37). The frequency of heterozygous subjects was 3.7, 18.2 and 1.7% for the C282Y, H63D and S65C mutations, respectively, and the allele frequencies were 0.019+/-0.01 for C282Y, 0.119+/-0.016 for H63D and 0.009+/-0.005 for S65C. The results suggest that the admixture of native populations with subjects of South European origin might have had an important role in the diffusion of HFE alleles in Venezuela. C282Y homozygous subjects were not found in this study. No HFE genotype studied here was associated with a significant elevation of serum ferritin concentrations, except for C282Y/H63D compound heterozygote found in one asymptomatic male. This finding supports the theory that the H63D mutation could be involved in alterations of iron parameters when inherited together with C282Y. Our results indicate that C282Y homozygotes will be rarely detected. Performance of HFE mutation analysis in individuals with high iron determinations would be recommended.
- Published
- 2005
- Full Text
- View/download PDF
38. Evaluation of serum antibody responses against the rotavirus nonstructural protein NSP4 in children after rhesus rotavirus tetravalent vaccination or natural infection.
- Author
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Vizzi E, Calviño E, González R, Pérez-Schael I, Ciarlet M, Kang G, Estes MK, Liprandi F, and Ludert JE
- Subjects
- Adolescent, Adult, Case-Control Studies, Diarrhea prevention & control, Diarrhea virology, Drug Evaluation, Enzyme-Linked Immunosorbent Assay, Female, Glycoproteins therapeutic use, Humans, Male, Middle Aged, Retrospective Studies, Rotavirus chemistry, Rotavirus immunology, Toxins, Biological therapeutic use, Viral Nonstructural Proteins therapeutic use, Antibodies, Viral blood, Antibody Formation, Glycoproteins immunology, Rotavirus Infections immunology, Rotavirus Vaccines immunology, Toxins, Biological immunology, Viral Nonstructural Proteins immunology
- Abstract
The immune response elicited by the rotavirus nonstructural protein NSP4 and its potential role in protection against rotavirus disease are not well understood. We investigated the serological response to NSP4 and its correlation with disease protection in sera from 110 children suffering acute diarrhea, associated or not with rotavirus, and from 26 children who were recipients of the rhesus rotavirus tetravalent (RRV-TV) vaccine. We used, as antigens in an enzyme-linked immunosorbent assay (ELISA), affinity-purified recombinant NSP4 (residues 85 to 175) from strains SA11, Wa, and RRV (genotypes A, B, and C, respectively) fused to glutathione S-transferase. Seroconversion to NSP4 was observed in 54% (42/78) of the children who suffered from natural rotavirus infection and in 8% (2/26) of the RRV-TV vaccine recipients. Our findings indicate that NSP4 evokes significantly (P < 0.05) higher seroconversion rates after natural infection than after RRV-TV vaccination. The serum antibody levels to NSP4 were modest (titers of < or = 200) in most of the infected and vaccinated children. A heterotypic NSP4 response was detected in 48% of the naturally rotavirus-infected children with a detectable response to NSP4. Following natural infection or RRV-TV vaccination, NSP4 was significantly less immunogenic than the VP6 protein when these responses were independently measured by ELISA. A significant (P < 0.05) proportion of children who did not develop diarrhea associated with rotavirus had antibodies to NSP4 in acute-phase serum, suggesting that serum antibodies against NSP4 might correlate with protection from rotavirus diarrhea. In addition, previous exposures to rotavirus did not affect the NSP4 seroconversion rate.
- Published
- 2005
- Full Text
- View/download PDF
39. [Molecular identification of bovine enteric calciviruses in Venezuela].
- Author
-
Alcalá AC, Hidalgo MA, Obando C, Vizzi E, Liprandi F, and Ludert JE
- Subjects
- Animals, Caliciviridae isolation & purification, Caliciviridae Infections virology, Cattle, Feces virology, Humans, Phylogeny, Reverse Transcriptase Polymerase Chain Reaction, Caliciviridae genetics, Caliciviridae Infections veterinary, RNA, Viral genetics
- Abstract
Caliciviruses are a well-established cause of respiratory, vesicular and hemorrhagic diseases in animals. In addition, these viruses are an important cause of enteric diseases in humans. Recently, molecular analysis of several bovine enteric calicivirus isolates indicated that they are genetically close to human enteric calicivirus. To investigate if bovine enteric caliciviruses circulate in Venezuela, 129 stool samples collected between 1994 and 2000 were assayed by reverse transcription-polymerase chain reaction amplification. The presence of calicivirus was confirmed in one of the samples analyzed, collected in the Lara State from a healthy calf, 2 months old. Phylogenetic studies based on partial RNA polymerase sequences indicated that the Venezuelan isolate (Bo/NV/Lara/2000/VE) is most closely related to the genogroup III, genus Noroviruses.
- Published
- 2003
40. Identification of human rotavirus strains with the P[14] genotype by PCR.
- Author
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Arista S, Vizzi E, Alaimo C, Palermo D, and Cascio A
- Subjects
- Capsid genetics, Humans, Polymerase Chain Reaction, Rotavirus classification, Rotavirus isolation & purification, Genome, Viral, Rotavirus genetics
- Abstract
A seminested PCR typing assay has been extended to identify rotavirus strains with the P[14] genotype. The specificity of the method was confirmed by Southern hybridization and by restriction analysis with the enzyme AluI. One out of four human rotavirus (HRV) strains with unusual subgroup-electropherotype linkage but none out of 50 HRV strains with usual linkage was typed as P[14].
- Published
- 1999
- Full Text
- View/download PDF
41. Chronic intestinal infection due to subgenus F type 40 adenovirus in a patient with AIDS.
- Author
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Dionisio D, Arista S, Vizzi E, Manneschi LI, Di Lollo S, Trotta M, Sterrantino G, Mininni S, and Leoncini F
- Subjects
- AIDS-Related Opportunistic Infections pathology, Adenovirus Infections, Human pathology, Adult, Chronic Disease, Diarrhea virology, Duodenal Diseases pathology, Duodenal Diseases virology, Duodenum ultrastructure, Duodenum virology, Feces virology, Humans, Intestinal Diseases pathology, Intestinal Mucosa ultrastructure, Intestinal Mucosa virology, Male, Microscopy, Electron, AIDS-Related Opportunistic Infections virology, Adenovirus Infections, Human virology, Adenoviruses, Human isolation & purification, Intestinal Diseases virology
- Abstract
A case of chronic intestinal infection due to adenovirus type 40 lasting for 13 months in a patient with AIDS is described. Adenovirus particles were detected by electron microscopy in biopsy samples taken from the duodenum 3 months after the onset of diarrhoea. The virus was identified as adenovirus type 40 in stool samples by ELISA monoclonal antibodies to adenovirus group antigen (MAd-g2) and types 40 and 41 (MA 40-1 and MA 41-1). No other enteropathogens were found. These data support a causal relationship between adenovirus 40 and the gastrointestinal symptoms of the patient. This is the first reported case of intestinal infection caused by adenovirus type 40 in a patient with AIDS.
- Published
- 1997
- Full Text
- View/download PDF
42. Identification of picobirnavirus from faeces of Italian children suffering from acute diarrhea.
- Author
-
Cascio A, Bosco M, Vizzi E, Giammanco A, Ferraro D, and Arista S
- Subjects
- Child, Electrophoresis, Polyacrylamide Gel, Female, Gastroenteritis virology, Humans, Italy epidemiology, Male, RNA, Viral analysis, Diarrhea virology, Feces virology, Picobirnavirus isolation & purification, Virus Diseases virology
- Abstract
Polyacrylamide gel electrophoresis of nucleic acid extracted from stool samples of diarrhoeic children revealed in 3 out of 690 (0.43%) specimens two electrophoretic bands with a migration pattern characteristic of picobirnavirus ds-RNA. In none of the 92 control children were similar bands detected. No other potential enteric pathogens were found in the patients with picobirnavirus infection.
- Published
- 1996
- Full Text
- View/download PDF
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