Serotype G9 rotavirus infections in adults in Sweden

Prevalence and Genetic Diversity of Group A Rotavirus Genotypes in Moscow (2019-2020)

Group A rotavirus (RVA) infection is the leading cause of hospitalization of children under 5 years old, presenting with symptoms of acute gastroenteritis. The aim of our study was to explore the genetic diversity of RVA among patients admitted to Moscow Infectious Disease Clinical Hospital No. 1 with symptoms of acute gastroenteritis. A total of 653 samples were collected from May 2019 through March 2020. Out of them, 135 (20.67%) fecal samples were found to be positive for rotavirus antigen by ELISA. RT-PCR detected rotavirus RNA in 80 samples. Seven G-genotypes (G1, G2, G3, G4, G8, G9, and G12) and three P-genotypes (P[8], P[4], and P[6]) formed 9 different combinations. The most common combination was G9P[8]. However, for the first time in Moscow, the combination G3P[8] took second place. Moreover, all detected viruses of this combination belonged to Equine-like G3P[8] viruses that had never been detected in Russia before. The genotype G8P[8] and G9P[4] rotaviruses were also detected in Moscow for the first time. Among the studied rotaviruses, there were equal proportions of Wa and DS-1-like strains; previous studies showed that Wa-like strains accounted for the largest proportion of rotaviruses in Russia.

Unexpected predominance of rotavirus G9P[8] strain in Tunisian adult diarrheal patients

Introduction. Group A Rotavirus (RVA) is known to be a major cause of acute gastroenteritis (AGE) in children but its role as a potential pathogen in immunocompetent adults is probably underestimated.Aim. To compare RVA infections in patients from different age groups.Methodology. Fecal samples were collected from patients aged from birth to 65 years, hospitalized or consulting for AGE between 2015 and 2017. All samples were screened by RT-PCR for the detection of VP6 gene specific of RVA. RVA-positive samples were VP7 and VP4 genotyped using multiplex semi-nested RT-PCR. Full-length VP7 gene of G9-positive strains were sequenced and submitted for phylogenetic analysis.Results. Of 1371 stool specimens collected from children (<5 years; n=454), older children (5 to <15 years; n=316) and adults (15-65 years; n=601), 165 (12.0 %) were RVA-positive. RVA detection rates were significantly higher in children and adults than in older children (15.8 % and 12.1 Vs 6.3 %, respectively; P<0.001). While RVA infections were mostly detected during the coldest months in children, they were observed all year-round in patients aged >5 years. Although G1P[8] remained the most prevalent combination (41.7 %) detected in children, G9P[8] strains widely predominated in adults (58.1 %), followed by G2P[4] (12.9 %). All characterized G9 strains clustered in the modern lineage III.Conclusion. RVA play an important role in AGE not only in children but also in adults. The findings of a wide G9 predominance in patients >5 years highlights the need for continuing surveillance in both pediatric and mature populations.

The Interactions between Host Glycobiology, Bacterial Microbiota, and Viruses in the Gut

Rotavirus (RV) and norovirus (NoV) are the major etiological agents of viral acute gastroenteritis worldwide. Host genetic factors, the histo-blood group antigens (HBGA), are associated with RV and NoV susceptibility and recent findings additionally point to HBGA as a factor modulating the intestinal microbial composition. In vitro and in vivo experiments in animal models established that the microbiota enhances RV and NoV infection, uncovering a triangular interplay between RV and NoV, host glycobiology, and the intestinal microbiota that ultimately influences viral infectivity. Studies on the microbiota composition in individuals displaying different RV and NoV susceptibilities allowed the identification of potential bacterial biomarkers, although mechanistic data on the virus-host-microbiota relation are still needed. The identification of the bacterial and HBGA interactions that are exploited by RV and NoV would place the intestinal microbiota as a new target for alternative therapies aimed at preventing and treating viral gastroenteritis.

Species A rotaviruses isolated from hospitalized patients over 5 years of age in Kolkata, India, in 2012/13

In hospital-based diarrhoeal disease surveillance at Infectious Diseases & Beliaghata-General Hospital (May-2012 to April-2013), Kolkata, India, stool samples were collected from patients < 5 years (n = 830) and > 5 years of age (n = 728) hospitalized with diarrhea. Group-A rotavirus (GARV) was identified by ELISA followed by multiplex RT-PCR. In children < 5 years of age, 53.4% of the samples were positive for GARV. In patients > 5 years to 90 years old, only 6.04% (n = 44) tested positive for GARV. G2P[4] strains (n = 16 [36.36%]) were the most prevalent, followed by G9P[4] strains (n = 13 [29.54%]), while P[4]-(n = 30 [68.18%]) was most prevalent among the P genotypes. The GARV strains G2, G9 and P[4] detected in adults clustered together in the phylogenetic tree with the GARV strains identified in children (< 5 years) during the same period. Rotavirus positivity was high among female patients (75%), suggesting that caregivers (mother/grandmother/older-siblings) may get infected through young children or may act as carriers for transmission.

Detection of diarrheal viruses circulating in adult patients in Thailand

A total of 332 fecal specimens collected during January-December 2008 from adult patients with diarrhea were screened for group A and C rotaviruses, noroviruses GI and GII, sapovirus, Aichi virus, human parechovirus, enterovirus, adenovirus and astrovirus by RT-multiplex PCR. The detection rate for diarrheal viruses was 4.2 %. Adenovirus and enterovirus were equally detected as the most predominant viruses, with prevalence of 1.2 %, followed by Aichi virus (0.9 %) and norovirus GII (0.6 %). Mixed infection with norovirus GII and human parechovirus was also detected (0.3 %). This study provides epidemiological data for a wide variety of diarrheal viruses circulating in adult patients with diarrhea in Chiang Mai, Thailand.

Molecular characterization of group A rotavirus found in elderly patients in Ireland; predominance of G1P[8], continued presence of G9P[8], and emergence of G2P[4]

Rotavirus is a major cause of gastroenteritis in young children worldwide. There have been several recent reports concerning rotavirus isolation from adults, particularly in the elderly, presenting with gastroenteritis. In this study, the authors report on rotavirus outbreaks in five separate elderly care facilities between April, and June 2011 in Ireland. The following genotypes were detected; G1P[8] (n = 5/11), G2P[4] (n = 2/11), and G9P[8] (n = 2/11). Thus, similarities to previous reports were found in that G1P[8] predominated, G9P[8] was still detected but G2P[4] was detected for the first time in a geriatric population in Ireland. Here also described is the detection of Group 2 lineage IIC rotavirus in Ireland for the first time.

Rotavirus infection and its genetic characterization in non-hospitalized adults with acute gastroenteritis in Shanghai, China

Rotavirus is a major cause of acute gastroenteritis in infants and young children, while its role as a pathogen in adults has long been underappreciated. In order to describe the epidemiological patterns and genetic characteristics of rotavirus causing sporadic acute gastroenteritis in adults, hospital-based surveillance of rotavirus infections was conducted in Shanghai, China, between June 2010 and May 2011. Stool specimens were collected from outpatients with acute gastroenteritis admitted to three local hospitals. Rotavirus was detected using a colloidal gold test device. G and P genotyping were performed by multiplex PCR assays, and the VP7 gene of G9 strains were sequenced for further genetic characterization. Of 1,479 adult diarrheal stool samples examined during the 1-year surveillance period, 138 (9.3 %) were found to be rotavirus positive. G1 appeared to be the predominant genotype (35.5 %), suggesting a shift from genotype G3 to G1 in the study population in Shanghai. Meanwhile, a high frequency of genotype G9 (27.5 %) was also observed, and G9 was also predominant (38.1 %) in the small number of children (n=123) involved in the present study. Other specificities detected in adults were G2 (12.3 %) and G3 (13.8 %). For P genotyping, only two types, P[8] and P[4], were detected. P[8] was dominant in both children and adults. Sequence and phylogenetic analysis revealed that these strains could be divided into two different groups, with clustering within G9 lineage 3 and the subcluster of Japanese and Chinese G9 strains, respectively. In comparison to the previous data, G9 strains established themselves in a short time span as an important genotype in Shanghai, China.

Molecular characterization of group A rotaviruses detected in children with gastroenteritis in Ireland in 2006–2009

Community and hospital-acquired cases of human rotavirus are responsible for millions of gastroenteritis cases in children worldwide, chiefly in developing countries, and vaccines are now available. During surveillance activity for human rotavirus infections in Ireland, between 2006 and 2009, a total of 420 rotavirus strains were collected and analysed. Upon either PCR genotyping and sequence analysis, a variety of VP7 (G1–G4 and G9) and VP4 (P[4], P[6], P[8] and P[9]) genotypes were detected. Strains G1P[8] were found to be predominant throughout the period 2006–2008, with slight fluctuations seen in the very limited samples available in 2008–2009. Upon either PCR genotyping and sequence analysis of selected strains, the G1, G3 and G9 viruses were found to contain E1 (Wa-like) NSP4 and I1 VP6 genotypes, while the analysed G2 strains possessed E2 NSP4 and I2 VP6 genotypes, a genetic make-up which is highly conserved in the major human rotavirus genogroups Wa- and Kun-like, respectively. Upon sequence analysis of the most common VP4 genotype, P[8], at least two distinct lineages were identified, both unrelated to P[8] Irish rotaviruses circulating in previous years, and more closely related to recent European humans rotaviruses. Moreover, sequence analysis of the VP7 of G1 rotaviruses revealed the onset of a G1 variant, previously unseen in the Irish population.

Characterization of group A rotavirus infections in adolescents and adults from Pune, India: 1993-1996 and 2004-2007

A total of 1,591 fecal specimens were collected in 1993-1996 and 2004-2007 from adolescents and adults with acute gastroenteritis in Pune, India for detection and characterization of rotavirus. At the two time points, group A rotavirus was detected in 8.6% and 16.2% of the adolescents and 5.2% and 17.2% of the adults, respectively. Reverse transcription-PCR with consensus primers followed by multiplex genotyping PCR detected common strains G1P[8], G2P[4], G3P[8], and G4P[8] in a total of 53.1% of the samples from 1993 to 1996, while the only prevalent strain identified in 2004-2007 was G2P[4] (23.5% of total). Uncommon rotavirus strains (G1P[4], G2P[8] G9P[6]/P[4]) increased from 7.8% (1993-1996) to 41.2% (2004-2007), while the prevalence of mixed rotavirus infections was high (39%/35%) at both time points. Mixed infections detected by multiplex PCR were confirmed by sequencing two or more individual genotype-specific PCR products of the VP7 and VP4 genes from the same sample. Phylogenetic analysis of the sequences showed circulation of a heterogeneous rotavirus strain population comprising genotypes G1 (lineages I and IIb), G2 (lineages I and IIb), G4 (lineage Ia), P[4] (lineages P[4]-5 and P[4]-1), P[8] (lineages P[8]-II and P[8]-III), and P[6] (M37-like lineage). The VP6 gene sequences of the nontypeable strains were most homologous to animal strains. This study documents the molecular epidemiology of rotavirus strains in adolescents and adults in India, and suggests that it may be important to monitor these strains over time for the potential impact on rotavirus vaccines under development for use in the Indian population. J. Med. Virol. 82:519-527, 2010. (c) 2010 Wiley-Liss, Inc.

[Predominance of G9 rotavirus in Valencia and Castellón between 2005 and 2007]

INTRODUCTION

Rotavirus is the leading cause of acute gastroenteritis in young children worldwide. Effective vaccines to prevent rotavirus infections are currently available, although their clinical use is still limited, and rotavirus still causes many episodes of infantile gastroenteritis, mainly during the winter seasons.

OBJECTIVE

To characterise G (VP7) and P (VP4) genotypes of rotaviruses causing acute gastroenteritis in children and to determine the prevalence of genotype G9 rotavirus in three public health areas in the provinces of Valencia and Castellon.

PATIENTS AND METHODS

Five-hundred and forty-one stool samples were prospectively collected from infants and children with gastroenteritis in the period between October 2005 and September 2008. They were analysed for rotavirus by ELISA or by immunochromatography. G and P genotyping was performed by reverse transcription and PCR (RT-PCR).

RESULTS

G and P rotavirus genotypes were characterised in a total of 525 faecal samples (97%), resulting in a global predominance of strains G9P[8] (56.5%) and G1P[8] (29.9%). During the period of time studied, G9P[8] was the G/P combination most frequently detected during the rotavirus seasons 2005-2006 and 2006-2007, being present in 81.2% and 64.7% of the patients, respectively. However, during the 2007-2008 season, G1P[8] strains were the most frequently found (68.8%), with a sharp decrease in G9P[8] strains to 7.2% of the samples.

CONCLUSIONS

Rotavirus G9P[8] have spread rapidly and widely during the 2005-2006 and 2006-2007 seasons, replacing other previously dominant genotypes (G1, G4) in our geographic area. Its incidence has declined sharply in 2007-2008, in which G1P[8] was again the predominating genotype.

Detection and genotyping of human rotavirus VP4 and VP7 genes by reverse transcriptase PCR and reverse hybridization

Rotavirus infections can be diagnosed in stool samples by serological and molecular methods. We developed a novel reverse transcriptase PCR (RT-PCR) method for the amplification of rotavirus RNA and a reverse hybridization assay on a strip to detect amplimers and identify the specific G and P genotypes present in human stool specimens. An additional aim was to permit specific identification of the rotavirus G1P[8] strain, used in the Rotarix vaccine. Novel broad-spectrum PCR primers were developed for both VP4 and VP7, permitting the amplification of a wide range of rotavirus genotypes. Primer sets comprise mixtures of defined primer sequences. For the identification of G and P genotypes, two reverse hybridization strip assays were developed. Both the VP4 and the VP7 strip contain universal probes for the detection of VP4 and VP7 sequences, irrespective of the G or P genotype. The VP4 strip contains type-specific probes for P[4], P[6], P[8], P[9], and P[10]. The VP7 strip contains type-specific probes for G1, G2, G3, G4, G5, G6, G8, and G9. In addition, probes to distinguish between wild-type G1 and G1 vaccine strain sequences were present. Testing by analysis of multiple reference strains confirmed that both RT-PCR methods allowed the detection of a broad spectrum of genotypes. RT-PCR for VP7 was more sensitive than RT-PCR for VP4, but all samples identified as positive for rotavirus antigen by an enzyme-linked immunosorbent assay (ELISA) were also positive for both VP4 and VP7. The high specificity of the reverse hybridization method was confirmed by sequence analysis as well as by type-specific PCR, and the vaccine strain could also be specifically identified. The reverse hybridization method permits accurate identification of mixed infections with different genotypes. Rotavirus genotypes for which no type-specific probes were present on the strip were adequately identified by the universal detection probes. The assay was formally validated by analyses of specificity, sensitivity, precision, accuracy, and robustness. In a panel of 149 ELISA-positive stool samples, comparison with conventional type-specific RT-PCR methods revealed the superiority of the novel method, mainly in cases of mixed rotavirus infections. This novel method permits highly accurate detection and identification of human rotavirus infections in stool samples. This validated assay could be useful for large-scale epidemiological and clinical trials.

The ever-changing landscape of rotavirus serotypes

Rotavirus is a double-stranded RNA virus that is characterized by substantial genetic diversity. The various serotypes of rotavirus have been determined by the presence of neutralizing epitopes on the outer capsid of the protein shell. At present, 5 rotavirus serotypes (G1, G2, G3, G4, G9) are the predominant circulating strains, accounting for approximately 95% of strains worldwide, although there is considerable geographic variability. Incidence rates for various serotypes also vary temporally with seasonal and year-to-year fluctuations. Unusual serotypes are generally uncommon, but new serotypes can emerge. In particular, G9[P8], a reassortment virus, was first identified in 1983 and in the last 10 to 15 years has become widely distributed worldwide. Indeed, G9[P8] has become highly prevalent in many countries in Europe and Australia, with somewhat lower incidence rates in South America, Africa, and Asia. The heterogeneity and ever-changing epidemiology of rotavirus underscores the need for continued surveillance to ensure that vaccination programs provide optimal protection.

Phylogeny of G9 rotavirus genotype: a possible explanation of its origin and evolution

BACKGROUND

G9 rotavirus genotype was isolated in the 1980s and re-emerged without a clear explanation in the mid-1990s as one of the most frequently occurring genotypes with distinct genetic and molecular characteristics.

OBJECTIVES

To study the G9 genotype sequence polymorphisms in Spain and compare them with the human and porcine G9 VP7 genes from the rest of the world. Complete phylogenetic analyses have been done to better characterize G9 genotypes, their relationships and evolution.

STUDY DESIGN

Twelve G9 VP7 genes from Spanish patients were sequenced and compared with 240 G genotype sequences. Nucleotide and amino acid sequence similarity percentages and neighbour-joining dendrograms were used to establish a new phylogenetic analysis.

RESULTS

Eight of the 12 Spanish sequenced samples had different nucleotide translated region sequences, which yielded only five different proteins. New nucleotide and amino acid sequence comparisons were made that differed from previously described results.

CONCLUSIONS

Spanish G9 genotype sequences have similar structure of those belonging to lineage III as the majority of the G9 sequences and share amino acid motifs with other sequences. The phylogenetic analyses of G9 genotypes confirmed the existence of 6 lineages, but did not confirm the 11 sublineages previously reported.

Unexpected substitution of dominant rotavirus G genotypes in French hospitalized children over five consecutive seasons

The study was designed to evaluate the circulation of group A rotaviruses in French hospitalized children, and to detect unusual strains. This prospective study was conducted from 2001 to 2006 in children consulting for acute diarrhea at the pediatric emergency department in three French University Hospitals. The rotaviruses were detected by rapid test and genotyped by RT-PCR on the basis of their outer capsid proteins VP4 (P-type) and VP7 (G-type). The stools from 757 children were analyzed. G1P[8] strains were predominant (44.0%), followed by G9P[8] (17.7%), G3P[8] 13.1%, G4P[8] (9.5%), and G2P[4] (1.8%); mixed rotavirus infections occurred in 2.3%. G9 rotaviruses emerged during the 2004-2005 season (73.4%) and remained the second most prevalent strains. Few unusual strains, G6, G8, G12 and P[6]-types, were detected. The monitoring of rotavirus infections should be maintained to document strain distribution and to assess the emergence of new reassortants that may not respond to current rotavirus vaccines.

Design of a multiplex nested PCR for genotyping of the NSP4 from group A rotavirus

A novel PCR method was developed to discriminate amongst genotypes A-C of the rotavirus non-structural protein 4 (NSP4). Genotype-specific primers were designed that correctly identified the NSP4 genotype when evaluated as a multiplex PCR with cell culture adapted rotavirus strains. Rotavirus strains B223 SGIG6P6[1], NCDV SGIG6P6[1] and SA11 SGIG3P5B[2] were used as control for NSP4 genotype A; A34 SGIG5P14[23], Gottfried SGIIG4P2B[6] and Wa SGIIG1P1A[8] for NSP4 genotype B; RRV SGIG3P5B[3] for NSP4 genotype C. Subsequently, the same set of specific primers was used to genotype a set of 77 Swedish clinical samples. The results showed that all human clinical samples analyzed belong to the NSP4 genotype B and the VP6 subgroup II.

Group A rotavirus genotypes in Germany during 2005/2006

During the 2005/2006 winter season a total of 802 group A positive rotavirus specimens of patients from different regions throughout Germany were genotyped. Amplicons from a one-tube RT-PCR were typed by analysis of their (type-specific) size using type-specific primers, fluorescent consensus primers and a capillary sequencer for detection. While G1P[8] was predominant (45.8%), G9P[8] has emerged as the second most frequent genotype combination (37.7%). The distribution of genotypes was heterogeneous, regional frequencies regarding G1 and G9 were ranging from 15.0 to 89.3% and from 7.1 to 67.7%, respectively. Furthermore, a few human rotavirus G10P[6] and G10P[8] infections were observed.

Mutated G4P[8] rotavirus associated with a nationwide outbreak of gastroenteritis in Nicaragua in 2005

During February and March 2005, one of the largest national recorded outbreaks of severe acute gastroenteritis occurred in Nicaragua, affecting >or=64,000 individuals and causing >or=56 deaths, predominantly in children under 5 years of age. Through a nationwide laboratory-based study, stool samples were collected and investigated for rotavirus. Of 108 stool samples examined, 72 (67%) were positive for rotavirus. While 69% (50/72) of the positive samples were found in children less than 2 years of age, 50% (6/12) of the adult samples were positive. A mutated G4P[8] strain was the most commonly recognized strain (85%), followed by mixed G strains (8%) and G9P[8] (7%) strains. Phylogenetic analysis of the VP7 gene revealed that the G4 strains belonged to the emerging lineage Ic and was distantly related to the ST3 and VA70 G4 strains. Secondary structure predictions of the VP7 G4 protein revealed an insert of an asparagine residue in position 76, which, combined with additional mutations, surprisingly modified two downstream beta-sheets at amino acid positions 80 to 85 and 115 to 119. The 2005 G4P[8] strain compared to a G4P[8] strain from 2002 had a substitution of an asparagine residue for threonine (Asn-->Thr) at position 96 within antigenic region A, thus eliminating a potential glycosylation site. The mutated G4 virus was introduced in Nicaragua after 2002 and probably emerged from Brazil, Argentina, or Uruguay.

Brazilian P[8],G1, P[8],G5, P[8],G9, and P[4],G2 rotavirus strains: Nucleotide sequence and phylogenetic analysis

Rotavirus epidemiological surveys with molecular analysis of strains are required for gastroenteritis control and prevention. Twenty-nine human rotavirus strains detected in Rio de Janeiro, Brazil, from 1986 to 2004 were characterized as P[8],G1, P[8],G5, P[8],G9, and P[4],G2 genotypes. The VP7 genes were sequenced and phylogenetic analysis was performed. Strains of genotype G1 revealed two distinct lineages, G1-3 and G1-4; strains of genotype G2 grouped in lineage G2-1; G5 strains clustered with other Brazilians G5 strains and G9 strains were closely related to each other in lineage G9-3, distinct from the original G9 strains detected in 1980s. The VP4 genes were analyzed and P[8] strains fell into two major genetic lineages, P[8]-2 and P[8]-3. Our findings document an intragenotype diversity represented by lineages and sublineages within rotavirus circulating in Rio de Janeiro from 1986 to 2004, before application of a vaccine (Rotarix) in Brazil. This report emphasizes the importance of continuing monitor genotypes to verify if uncommon strains or newly strains are emerging to be specifically addressed in future vaccine trials.

Nitazoxanide in the treatment of viral gastroenteritis: a randomized double-blind placebo-controlled clinical trial

BACKGROUND

Enteric viruses including noroviruses and rotavirus are leading causes of diarrhoeal disease and gastroenteritis worldwide, and there is no effective treatment.

AIM

To evaluate nitazoxanide, a thiazolide anti-infective agent, in treating viral gastroenteritis in adults and adolescents.

METHODS

50 out-patients at least 12 years of age (mean 33.5 years) presenting with diarrhoea and stool-positive by enzyme-linked immunosorbent assay for norovirus, rotavirus or adenovirus were enrolled in a double-blind, placebo-controlled clinical trial. Patients were randomly assigned either nitazoxanide 500 mg or placebo twice daily for 3 days. The primary end point was time from first dose to resolution of symptoms. Analysis was modified intent-to-treat for 45 patients, excluding five patients with other identified enteropathogens at baseline.

RESULTS

The median time from first dose to resolution of symptoms was 1.5 days (IQR: 0.5-2.5) for nitazoxanide-treated patients and 2.5 days (IQR: 1.5-4.5) for the placebo group. Significant reductions in time to resolution of symptoms were observed for all patients analysed (P < 0.0001) and for subsets of patients with rotavirus (P = 0.0052) and norovirus (P = 0.0295). The number of patients with adenovirus (n = 5) was too small to draw any conclusion. No significant adverse events were reported.

CONCLUSIONS

Nitazoxanide may play an important role in managing viral gastroenteritis in adults.

Rotavirus infection is not associated with small intestinal fluid secretion in the adult mouse

In contrast to humans, adult but not infant small animals are resistant to rotavirus diarrhea. The pathophysiological mechanism behind this age-restricted diarrhea is currently unresolved, and this question was investigated by studying the secretory state of the small intestines of adult mice infected with rotavirus. Immunohistochemistry and histological examinations revealed that rotavirus (strain EDIM) infects all parts of the small intestines of adult mice, with significant numbers of infected cells in the ilea at 2 and 4 days postinfection. Furthermore, quantitative PCR revealed that 100-fold more viral RNA was produced in the ilea than in the jejuna or duodena of adult mice. In vitro perfusion experiments of the small intestine did not reveal any significant changes in net fluid secretion among mice infected for 3 days or 4 days or in those that were noninfected (37 +/- 9 microl . h(-1) . cm(-1), 22 +/- 13 microl . h(-1) . cm(-1), and 33 +/- 6 microl . h(-1) . cm(-1), respectively) or in transmucosal potential difference (4.0 +/- 0.3 mV versus 3.9 +/- 0.4 mV), a marker for active chloride secretion, between control and rotavirus-infected mice. In vivo experiments also did not show any differences in potential difference between uninfected and infected small intestines. Furthermore, no significant differences in weight between infected and uninfected small intestines were found, nor were any differences in fecal output observed between infected and control mice. Altogether, these data suggest that rotavirus infection is not sufficient to stimulate chloride and water secretion from the small intestines of adult mice.

Rotavirus diarrhea in children and adults in a southern city of Brazil in 2003: Distribution of G/P types and finding of a rare G12 strain

Between May and August in 2003, a total of 251 fecal samples were collected from children and adults with diarrhea (5 inpatients and 246 outpatients) at a private hospital in the city of Ponta Grossa, the state of Paraná, Brazil. Group A rotavirus was detected in 71 of 251 (28.3%) specimens: 55 (77.5%) from children under 5 years of age and 16 (22.5%) from individuals aged 6-72 years. All 71 strains exhibited a "long" RNA pattern when analyzed by PAGE. Sixty-one positive samples that yielded enough RNA were submitted to PCR genotyping. The most frequent G/P genotype combination detected was G1P[8] (86.9%; 53/61) followed by G9P[8] (3.3%; 2/61) and G12P[9] (1.6%; 1/61). Rotaviruses with G2, G3, G4, P[4], or P[6] specificity were not detected. For three strains (4.9%) bearing G1 genotype, the VP4 specificity could no be determined, and two specimens (3.3%) remained G/P non-typeable. One rotavirus strain (HC91) bearing G12P[9] genotype with a "long" electropherotype was isolated from an 11-month-old boy with diarrhea for the first time in Brazil. The cell-culture grown HC91 strain was shown to belong to serotype G12 by neutralization.

Association of the G4 rotavirus genotype with gastroenteritis in adults

Rotavirus is the most common etiological cause of acute viral gastroenteritis in infants and young children worldwide, yet its role in the adult population is less well understood. We have recently identified rotavirus as the causative agent of severe diarrhea in adults, specifically in two gastroenteritis outbreaks in separate care for the elderly homes. Strain typing has shown the continued presence of P[8]G1, the emergence of P[8]G9, and the reemergence of P[8]G4. A total of 26 community cases and 6 outbreak cases of rotavirus infection, positive via a molecular screening assay, were subsequently amplified using VP4 and VP7 specific primers (Con2/Con3 and 1A/1B primer sets, respectively). The age range of patients investigated was from <1 year to 89 years. The resulting PCR products were cloned into TOPO10 PCR IV vector and sequenced to give the P- and G-type accordingly. All sequence data were subjected to BLAST analysis. Three different rotavirus types P[8]G1, P[8]G4, and P[8]G9 were identified. Types P[8]G1 and P[8]G9 were identified as circulating within the community, whereas the third type P[8]G4 was identified only in an elderly care outbreak. The identification of G9 rotaviruses supports evidence of emergence of the genotype on a global scale.

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

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.