Eduardo M. Volotão

Rotavirus Strains Bearing Genotype G9 or P[9] Recovered from Brazilian Children with Diarrhea from 1997 to 1999

ABSTRACT Human rotavirus strains belonging to genotype G9 or P[9] were detected in a collection of stool specimens from children with diarrhea in two cities of the state of Rio de Janeiro, Brazil, between March 1997 and December 1999. G9 strains were first detected in April 1997 and remained prevalent until the end of the study, at a frequency of 15.9% (n = 157). A high percentage of VP7 nucleotide (99.0 to 99.5%) and deduced amino acid identity (98.6 to 99.1%) was found between three randomly selected Brazilian G9 strains and the American G9 strain US1205. A novel G9:P[4] genotype combination was detected in addition to G9:P[8] and G9:P[6], demonstrating that this G genotype may undergo constant genetic reassortment in nature. The P[9] rotavirus strains constituted 10.2%, the majority of which were detected between April and July 1997. The RNA electrophoretic migration pattern of the G3:P[9] strains resembled that of AU-1 virus (G3:P3[9]), suggesting a genetic similarity between the Brazilian G3:P[9] strains and the Japanese virus, which is similar to a feline rotavirus genetically.

Predominance of Rotavirus Genotype G9 during the 1999, 2000, and 2002 Seasons among Hospitalized Children in the City of Salvador, Bahia, Brazil: Implications for Future Vaccine Strategies

ABSTRACT Two hundred eight of 648 (32%) diarrheal stool samples collected from hospitalized children under 5 years of age during a 3-year period (1999, 2000, and 2002) in the city of Salvador, in the state of Bahia, Brazil, were rotavirus positive. One hundred sixty-four of 208 (78.8%) rotavirus-positive samples had genotype G9 specificity, predominantly in association with P[8]. Other specificities detected were G1 (12.0%) and G4 (1.4%). Viruses with G2, G3, or P[4] specificity were not detected. Rotavirus genotype G9 predominated during each of the three seasons studied; it represented 89.2% of rotavirus strains detected in 1999, 85.3% in 2000, and 74.5% in 2002. G1 viruses (the globally most common G type) have a unique epidemiological characteristic of maintaining predominance during multiple consecutive rotavirus seasons. We have shown in this study for the first time that the G9 viruses also have a similar epidemiological characteristic, albeit for a shorter period of surveillance. The next generation of rotavirus vaccines will need to provide adequate protection against disease caused by G9 viruses.

VP7 gene polymorphism of serotype G9 rotavirus strains and its impact on G genotype determination by PCR

Rotaviruses are the single most important etiologic agents of severe diarrhea of infants and young children worldwide. Surveillance of rotavirus serotypes/genotypes (both VP7[G] and VP4[P]) is in progress globally in which polymerase chain reaction (PCR) has been the assay of choice. We investigated polymorphism of the VP7 gene of serotype G9 rotavirus strains and its impact on the determination of VP7 gene genotype by PCR assay. By VP7 gene sequence analysis, we and others have previously shown that the G9 rotavirus strains belong to one of three VP7 gene lineages. By PCR assay using three different sets of commonly used primers specific for G1-4, 8 and 9, 23 Brazilian G9 strains and 5 well-characterized prototype G9 strains which collectively represented all three VP7 gene lineages were typed as: (i). G3; (ii). G4; (iii). G9; (iv). G3 and G9; or (v). G9 and G4 depending on a primer pool employed. This phenomenon appeared to be due to: (i). a VP7 gene lineage-specific polymorphism, more specifically mutation(s) in the primer binding region of the VP7 gene of G9 strain; and (ii). the magnitude of difference in nucleotide homology at respective primer binding site between homotypic (G9) and heterotypic (G3 or G4) primers present in a primer pool employed.

Surveillance of Rotavirus Strains in Rio de Janeiro, Brazil, from 1997 to 1999

ABSTRACT One hundred fifty-seven (23%; n = 678) rotavirus-positive stool samples were collected between March 1997 and December 1999 in the cites of Rio de Janeiro and Niterói. Rotaviruses in 143 (91%) samples were genotyped by reverse transcription-PCR for G and/or P specificity. Rotaviruses in the majority of G-P-typeable samples (73.3%; 74 of 101) were identified as having globally common genotypes G1P[8], G2P[4], G3P[8], and G4P[8]. Unusual strains such as G1P[9], G2[P8], G3P[9], and G9P[4] strains were detected in 8.9% (9 of 101) of the samples. Genotypes G9P[8], G9P[6], and a mixture of G9 and other G or P types represented 15.9% (25 of 157) of the isolates. Mixed infections were detected in 25 (15.9%) samples, and rotaviruses in 15 samples (9.6%) were not typed.

Prevalence of enteric adenoviruses among children with diarrhea in four Brazilian cities

BACKGROUND Enteric adenoviruses are related to child diarrhea and appear to be spread worldwide. OBJECTIVES The aim of the present study was to determine the prevalence of enteric adenovirus infection among children in four Brazilian cities. STUDY DESIGN stool specimens were collected from children under 5 years of age with acute diarrhea. RESULTS AND CONCLUSIONS Enteric adenoviruses were detected in 1.55% (n=1420) of the samples analyzed indicating the circulation of these viruses among Brazilian children in association to diarrheal disease. These agents were isolated throughout the year demonstrating no specific seasonal distribution. Also, no pattern of serotype distribution between the cities was observed.

Genotyping of enteric adenoviruses by using single-stranded conformation polymorphism analysis and heteroduplex mobility assay.

ABSTRACT Single-stranded conformation polymorphism (SSCP) analysis and heteroduplex mobility assays (HMAs) were used to identify and genotype enteric adenoviruses (EAd). The results were compared to those of restriction endonuclease assays, species-specific PCRs, and direct nucleotide sequence analyses. Of the 31 stool samples tested, 15 isolates were identified as EAd and 7 were identified as nonenteric Ad by all methods. An agreement of 100% was found between the SSCP and HMA results.

Adenoviruses isolated from civilian and military personnel in the city of Rio de Janeiro, Brazil

Adenovirus are important pathogen primarily associated to respiratory infections of children and military personnel, even though it is also associated to cases of conjunctivitis and keratoconjunctivitis. We analyzed respiratory secretion collected from subjects with and without respiratory infection symptoms, being 181 civilians and 221 military subjects. The samples were inoculated in HEp-2 and/or A549 tissue cultures for viral isolation. Samples presenting cytopathogenic effect (CPE) in any tissue culture were tested by a polymerase chain reaction (PCR) assay to confirm adenovirus isolation. The isolates confirmed as adenovirus were further analyzed by restriction endonuclease assay for determination of viral species. Three isolates were identified as specie A (two from civilian and one from military), one isolate from military was identified as specie C, and one isolate from civilian was identified as specie D. For two isolates the specie could not be identified.