RESUMO
To examine the epidemiology of rotaviruses in Buenos Aires, Argentina, we screened 1,212 stool samples from children with diarrhea in the southern district of Buenos Aires from 1999 to 2003. We identified 187 samples (15.4%) that were positive for group A rotavirus by use of antigen enzyme-linked immunosorbent assay. Among these specimens, 112 were available for typing: 93 (83.0%) were single-type infections, 9 (8.0%) were mixed-type infections with more than one G or P type, and 10 (8.9%) were G and/or P nontypeable. In contrast to the findings in our last study, from 1996 to 1998, genotype P[4], G2 strains were almost completely absent and P[8], G1 and P[8], G4 strains were dominant, representing more than 80% of the G and P types found. Genotypes G2 and G9 were detected in few samples, and type G3 was completely absent. We identified several uncommon genotype G12 strains, representing the first detections outside of Asia and the United States, by sequencing. Using a genotype G12-specific reverse transcription-PCR, we identified eight (6.7%) positive samples for the 1999 to 2003 period. The high degree of sequence identity between recent G12 isolates from Argentina, the United States, and Asian countries suggests a relatively recent introduction(s) of these strains into humans from a common progenitor. The Argentinean G12 strains belonged to genotype P[9], similar to most of the recently described Asian G12 strains. The finding of G12 strains in several other regions of the world raises the possibility that G12 may be emerging globally and suggests that surveillance for this strain should be conducted routinely.
Assuntos
Diarreia/epidemiologia , Epidemiologia Molecular , Infecções por Rotavirus/epidemiologia , Rotavirus/classificação , Rotavirus/genética , Antígenos Virais/genética , Argentina/epidemiologia , Proteínas do Capsídeo/genética , Criança , Pré-Escolar , Diarreia/virologia , Fezes/virologia , Genótipo , Humanos , Dados de Sequência Molecular , Vigilância da População , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/isolamento & purificação , Infecções por Rotavirus/virologia , Análise de Sequência de DNARESUMO
In the course of characterizing 103 rotaviruses from children in Mexico, we found that the majority of strains were globally common types (55.4% of total), while uncommon types represented 5.7%, mixed infections with common types represented 14.8%, and partially or fully nontypeable isolates represented about 24%. Serotype G9 was detected for the first time in Mexico. We sequenced a subset of strains that were G nontypeable by reverse transcriptase PCR and found surprisingly that two strains having common human rotavirus P genotypes (8 and 6) had serotype G3 and G4 VP7 gene sequences that shared closer homology with canine and porcine strains, respectively, than with human strains, suggesting that these isolates represented reassortants between human and animal rotaviruses.
Assuntos
Antígenos Virais , Proteínas do Capsídeo/genética , Cães/virologia , Rotavirus/classificação , Suínos/virologia , Animais , Sequência de Bases , Criança , Genótipo , Humanos , México , Dados de Sequência Molecular , RNA Viral/análise , Vírus Reordenados/genética , Rotavirus/genéticaRESUMO
Rotaviruses (RV) are important etiological agents of acute gastroenteritis in infants and young children, as well as the young of a variety of animals worldwide. These viruses belong to Reoviridae family and contain a genome of 11 segments of double-stranded RNA (dsRNA). Two major proteins, VP4 and VP7, encoded by genome segments 4 and 7, 8 or 9, respectively, evoke a neutralizing antibody response and form the basis for the current classification of group (gp) A rotavirus into P (VP4) and G (VP7) serotypes. Although much recent progress has been made on the molecular biology of gp C RV, routine methods to detect and discriminate human, porcine, and bovine strains are not available widely. In this study, a multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) and digoxigenin-labeled (dig) oligonucleotide probes using chemiluminescence has been developed to detect and discriminate VP7 genes from culture-adapted and field isolates of human, porcine and bovine gp C RV. The multiplex RT-PCR and dig-probes were specific for the VP7 genes of human, porcine and bovine gp C RV and allowed detection and characterization of single and mixed infections of porcine gp C RV with porcine gp A or gp B rotaviruses. Detection rates for gp C RV were more than 50% when compared with polyacrylamide gel electrophoresis. These new diagnostic assays may help determine the epidemiological importance of these viruses in human and animal infections.
Assuntos
Antígenos Virais , Proteínas do Capsídeo , Técnicas de Sonda Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Rotavirus/genética , Rotavirus/isolamento & purificação , Virologia/métodos , Animais , Sequência de Bases , Capsídeo/genética , Bovinos , Pré-Escolar , Primers do DNA/genética , Digoxigenina , Gastroenterite/diagnóstico , Gastroenterite/epidemiologia , Gastroenterite/virologia , Genes Virais , Humanos , Lactente , Epidemiologia Molecular , Sondas de Oligonucleotídeos , Rotavirus/classificação , Infecções por Rotavirus/diagnóstico , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia , SuínosRESUMO
To evaluate enteropathogens and other factors associated with severe disease in children with diarrhea, 381 children <5 years of age with diarrhea and moderate to severe dehydration (in-patients) and 381 age-, sex-, and date-of-visit-matched children with mild diarrhea (out-patients) presenting to a hospital in Peru, were studied. Rotavirus was detected in 52% of the in-patients and 35% of the out-patients (odds ratio [OR]=2.3, 95% confidence interval [95% CI]= 1.6-3.2); 95% of the rotaviruses among in-patients were of serotypes G1-G4. The risk of severe diarrhea was particularly great in children who were not exclusively breast-fed in early infancy and who also lacked piped water in their homes (for children with both characteristics OR=6.8, 95% CI=3.6-12.8). The high prevalence of rotavirus and its association with severe diarrhea underscores the need for rotavirus vaccines. Interventions to educate mothers and improve access to safe water should augment the impact of rotavirus vaccines in preventing severe diarrhea.
Assuntos
Diarreia/etiologia , Infecções por Rotavirus/epidemiologia , Animais , Pré-Escolar , Diarreia/microbiologia , Diarreia/parasitologia , Diarreia/virologia , Eucariotos/isolamento & purificação , Fezes/microbiologia , Fezes/parasitologia , Fezes/virologia , Bactérias Gram-Negativas/isolamento & purificação , Infecções por Bactérias Gram-Negativas/diagnóstico , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Lactente , Recém-Nascido , Análise por Pareamento , Peru/epidemiologia , Infecções por Protozoários/diagnóstico , Infecções por Protozoários/epidemiologia , Infecções por Protozoários/parasitologia , Fatores de Risco , Rotavirus/isolamento & purificação , Infecções por Rotavirus/diagnóstico , Infecções por Rotavirus/virologiaRESUMO
Group C rotaviruses are fastidious in their in vitro cell culture requirements. Recent serosurveys indicate that antibody to group C rotavirus is present in 3-45 per cent of the human population in certain geographic locations, suggesting that rotavirus group C infection is more prevalent than previously believed and that the low rate of detection of these agents is probably due to the lack of sensitive diagnostic assays. From March to December 1994, 406 fecal specimens were collected from children under five years of age who were outpatients at the emergency services of nine public hospitals in Brasília, Federal District, Brazil. In addition to the samples from children, one public outpatient unit requested virological investigation of a stool sample from an HIV-seropositive adult male with diarrhea of sudden onset. All samples were analyzed by enzyme immunoassay for group A rotavirus and adenovirus (EIARA) and by polyacrylamide gel electrophoresis (PAGE). One hundred and seven (26 per cent) were positive for group A rotavirus. Four samples from children and the sample from the HIV-seropositive patient, although negative by EIARA, showed a group C rotavirus profile by PAGE and were positive for rotavirus by electron microscopy. Using specific VP6 and VP7 primers for group C rotavirus, a reverse transcriptase-polymerase chain reaction (RT-PCR) was performed and products were detected by agarose gel electrophoresis and ethidium bromide staining. These products were confirmed to be specific for group C rotavirus by using digoxigenin-oligonucleotide probes, Southern hybridization and chemiluminescent detection. The five positive group C rotavirus samples were detected in August (3 samples) and September (2 samples). To the best of our knowledge, this is the first report of group C rotavirus detected in the Federal District, Brazil and in an HIV-seropositive patient with acute gastroenteritis.
Assuntos
Humanos , Recém-Nascido , Lactente , Pré-Escolar , Masculino , Adulto , Diarreia Infantil/virologia , Infecções por Rotavirus/diagnóstico , Rotavirus/isolamento & purificação , Brasil , Eletroforese em Gel de Poliacrilamida , HIV , Técnicas Imunoenzimáticas , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Group C rotaviruses are fastidious in their in vitro cell culture requirements. Recent serosurveys indicate that antibody to group C rotavirus is present in 3-45% of the human population in certain geographic locations, suggesting that rotavirus group C infection is more prevalent than previously believed and that the low rate of detection of these agents is probably due to the lack of sensitive diagnostic assays. From March to December 1994, 406 fecal specimens were collected from children under five years of age who were outpatients at the emergency services of nine public hospitals in Brasília, Federal District, Brazil. In addition to the samples from children, one public outpatient unit requested virological investigation of a stool sample from an HIV-seropositive adult male with diarrhea of sudden onset. All samples were analyzed by enzyme immunoassay for group A rotavirus and adenovirus (EIARA) and by polyacrylamide gel electrophoresis (PAGE). One hundred and seven (26%) were positive for group A rotavirus. Four samples from children and the sample from the HIV-seropositive patient, although negative by EIARA, showed a group C rotavirus profile by PAGE and were positive for rotavirus by electron microscopy. Using specific VP6 and VP7 primers for group C rotavirus, a reverse transcriptase-polymerase chain reaction (RT-PCR) was performed and products were detected by agarose gel electrophoresis and ethidium bromide staining. These products were confirmed to be specific for group C rotavirus by using digoxigenin-oligonucleotide probes, Southern hybridization and chemiluminescent detection. The five positive group C rotavirus samples were detected in August (3 samples) and September (2 samples). To the best of our knowledge, this is the first report of group C rotavirus detected in the Federal District, Brazil and in an HIV-seropositive patient with acute gastroenteritis.
Assuntos
Diarreia Infantil/virologia , Infecções por Rotavirus/diagnóstico , Rotavirus/isolamento & purificação , Adulto , Brasil , Pré-Escolar , Humanos , Lactente , Recém-Nascido , MasculinoRESUMO
We report the molecular characterization of rotavirus genotype P[8]G5 strains found in fecal specimens collected in four different regions of Brazil, using digoxigenin(dig)-labeled oligonucleotide probes, sequence analysis, and RNA-RNA hybridization. The closest sequence relationships of the neutralization antigens of these strains were to the VP4 protein of P1A[8]G1 strain KU (93.3% identity in amino acids 11 to 282) and to the VP7 protein of G serotype 5 strain OSU (87.6% identity in amino acids 8 to 232). Based on VP7 sequence differences, we designed dig-probes that allowed us to discriminate porcine OSU-like strains from G5 strains isolated from Brazilian infants. The genetic relationships of two P[8]G5 isolates to other rotavirus genogroups were analyzed by RNA-RNA hybridization with [32P]-GTP probes representative of serotypes P1A[8]G1 (Wa), P[8]G3 (AU17), and P9[7]G5 (OSU). The Brazilian P[8]G5 strains showed sequence homology with genes of Wa-like and OSU-like strains, suggesting that these two strains were naturally occurring reassortants between members of the Wa and porcine rotavirus genogroups. The identification of these strains in diverse geographic areas of Brazil underscores their stability and demonstrates the emergence of clinically important rotavirus diarrhea strains by reassortment.
Assuntos
Proteínas do Capsídeo , RNA Viral/análise , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/genética , Rotavirus/genética , Sequência de Aminoácidos , Antígenos Virais/genética , Antígenos Virais/imunologia , Brasil/epidemiologia , Capsídeo/genética , Capsídeo/imunologia , Células Cultivadas , Pré-Escolar , Fezes/virologia , Genes Virais , Humanos , Lactente , Recém-Nascido , Epidemiologia Molecular , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase , RNA Viral/genética , Alinhamento de Sequência , Análise de Sequência de RNA , Homologia de Sequência de AminoácidosRESUMO
We used reverse transcription-polymerase chain reaction (RT-PCR) to determine the P and G genotypes of 130 culture-adapted rotavirus strains isolated from 181 fecal specimens of children under 5 years of age from 9 states and the Federal District of Brazil. The 4 genotypes found most commonly worldwide were also common in Brazil and P[8]G1 was the most prevalent (43%), followed by P[4]G2 (12%), P[8]G3 (6%), and P[8]G4 (6%). However, unusual types P[8]G5, P[6]G2, P[9]G1, P[9]G3, and mixed infections were responsible for 12% and 21% of the cases, respectively. Genotype G5 strains were detected in specimens collected in all 9 areas surveyed from all 4 regions of Brazil. The unusual strain diversity in Brazil suggests that when tetravalent rotavirus vaccines currently being developed are introduced into Brazil, laboratory surveillance will be essential to monitor protection against unusual strains, particularly those of genotype 5, as well as emergence of novel reassortants that may evolve from the large pool of children with mixed infections.
PIP: Rotavirus is an important cause of acute gastroenteritis in many species of animals and humans, and is responsible for about 870,000 deaths annually among children under 5 years old, mostly in developing countries. Rotavirus disease will most likely be controlled through the development and widespread use of an effective vaccine. In anticipation of the possible use of such a vaccine in Brazil, the authors characterized the most common strains of rotavirus in circulation in the country. Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the P and G genotypes of 130 culture-adapted rotavirus strains isolated from 181 fecal specimens of children under age 5 years from 9 states and the Federal District of Brazil. The 4 genotypes found most commonly worldwide were also common in Brazil, with P[8]G1 being the most prevalent in 43% of cases, followed by P[4]G2 (12%), P[8]G3 (6%), and P[8]G4 (6%). The unusual types P[8]G5, P[6]G2, P[9]G1, and P[9]G3 were responsible for 12% of the cases, and mixed infections were responsible for 21% of cases. Genotype G5 strains were detected in specimens collected in all 9 areas surveyed from all 4 regions of Brazil. This unusual strain diversity in Brazil suggests that when tetravalent rotavirus vaccines currently being developed are introduced into Brazil, laboratory surveillance will be key to monitoring protection against unusual strains, especially those of genotype 5, as well as new reassortants which may evolve from the pool of children with mixed infections.