Rotavirus, Norovirus and Astrovirus in Children Aged 0 - 5 Years: Evolution of Prevalence over 10 Years (2013-2023) Following the Introduction of Rotavirus Vaccines in Burkina Faso

Rotaviruses, noroviruses, and astroviruses are responsible for gastroenteritis in children under 5 years old. The objective of our study was to estimate the evolution of prevalence of rotavirus, norovirus and astrovirus infections in children aged 0 to 5 years with gastroenteritis, after the introduction of rotavirus vaccines in Burkina Faso. This cross-sectional study was conducted between January and December 2023, collecting 100 stool samples from children with gastroenteritis at Saint Camille Hospital in Ouagadougou and the Charles De Gaulle University Paediatric Hospital. Noroviruses and astroviruses were detected using multiplex real-time PCR with a Sacace biotechnology detection kit. Data analysis was performed with Stata statistical software, version 16.0. The prevalence of norovirus infections was 14% and astrovirus infections were 9%. Rotavirus infections were found at prevalence of 15%. The age group most affected by norovirus and astrovirus infections was 0 - 12 months, with respective prevalence rates of 73.34% and 55.56%. The most frequently observed clinical signs in children infected with astrovirus were fever (77.78%), diarrhea (55.56%), and vomiting (44.44%). The introduction of rotavirus vaccines has reduced rotavirus-related infections. However, this has not significantly impacted the prevalence of norovirus and astrovirus infections in Burkina Faso.

The protective role of prebiotics and probiotics on diarrhea and gut damage in the rotavirus-infected piglets

Rotavirus is one of the pathogenic causes that induce diarrhea in young animals, especially piglets, worldwide. However, nowadays, there is no specific drug available to treat the disease, and the related vaccines have no obvious efficiency in some countries. Via analyzing the pathogenesis of rotavirus, it inducing diarrhea is mainly due to disturb enteric nervous system, destroy gut mucosal integrity, induce intracellular electrolyte imbalance, and impair gut microbiota and immunity. Many studies have already proved that prebiotics and probiotics can mitigate the damage and diarrhea induced by rotavirus infection in hosts. Based on these, the current review summarizes and discusses the effects and mechanisms of prebiotics and probiotics on rotavirus-induced diarrhea in piglets. This information will highlight the basis for the swine production utilization of prebiotics and probiotics in the prevention or treatment of rotavirus infection in the future.

Epidemiological Surveillance: Genetic Diversity of Rotavirus Group A in the Pearl River Delta, Guangdong, China in 2019

Objective This study aimed to understand the epidemic status and phylogenetic relationships of rotavirus group A(RVA)in the Pearl River Delta region of Guangdong Province,China.Methods This study included individuals aged 28 days–85 years.A total of 706 stool samples from patients with acute gastroenteritis collected between January 2019 and January 2020 were analyzed for 17 causative pathogens,including RVA,using a Gastrointestinal Pathogen Panel,followed by genotyping,virus isolation,and complete sequencing to assess the genetic diversity of RVA.Results The overall RVA infection rate was 14.59%(103/706),with an irregular epidemiological pattern.The proportion of co-infection with RVA and other pathogens was 39.81%(41/103).Acute gastroenteritis is highly prevalent in young children aged 0–1 year,and RVA is the key pathogen circulating in patients 6–10 months of age with diarrhea.G9P[8](58.25%,60/103)was found to be the predominant genotype in the RVA strains,and the 41 RVA-positive strains that were successfully sequenced belonged to three different RVA genotypes in the phylogenetic analysis.Recombination analysis showed that gene reassortment events,selection pressure,codon usage bias,gene polymorphism,and post-translational modifications(PTMs)occurred in the G9P[8]and G3P[8]strains.Conclusion This study provides molecular evidence of RVA prevalence in the Pearl River Delta region of China,further enriching the existing information on its genetics and evolutionary characteristics and suggesting the emergence of genetic diversity.Strengthening the surveillance of genotypic changes and gene reassortment in RVA strains is essential for further research and a better understanding of strain variations for further vaccine development.

Exploring the impact of rotavirus vaccination on antibiotic prescription and resistance:A comprehensive systematic review

BACKGROUND Rotavirus is a highly contagious virus responsible for a significant burden of acute gastroenteritis,particularly among infants and young children worldwide,however,vaccination against this viral agent is available.Several studies have hypothesized that rotavirus vaccination has been linked to lower rates of antibiotic resistance.AIM To assess the relationship between rotavirus vaccination and antibiotic resistance.METHODS The present systematic review was tailored based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines.Several electronic databases(PubMed/MEDLINE,Scopus and Web of Science)were searched independently by two investigators in order to retrieve relevant publications published until April 2023 that investigated the aforementioned research question.RESULTS The comprehensive database search identified a total of 91 records.After the duplicates were removed(n=75),we screened the titles and abstracts of 16 potentially eligible publications.After the irrelevant records were excluded(n=5),we screened the full texts of 11 manuscripts.Finally,5 studies were entered into the qualitative and quantitative analysis.CONCLUSION In conclusion,all the studies support the idea that vaccinations can reduce the need for antibiotic prescriptions which could potentially contribute to mitigating antibiotic resistance.However,to fully comprehend the mechanisms of antibiotic resistance,enhance treatment guidelines,and consider diverse demographic situations,further research is necessary to use evidence-based strategies to fight antibiotic misuse and resistance.

Driving forces of continuing evolution of rotaviruses

Rotaviruses are non-enveloped double-stranded RNA virus that causes acute diarrheal diseases in children(<5 years).More than 90%of the global rotavirus infection in humans was caused by Rotavirus group A.Rotavirus infection has caused more than 200000 deaths annually and predominantly occurs in the low-income countries.Rotavirus evolution is indicated by the strain dynamics or the emergence of the unprecedented strain.The major factors that drive the rotavirus evolution include the genetic shift that is caused by the reassortment mechanism,either in the intra-or the inter-genogroup.However,other factors are also known to have an impact on rotavirus evolution.This review discusses the structure and types,epidemiology,and evolution of rotaviruses.This article also reviews other supplemental factors of rotavirus evolution,such as genetic reassortment,mutation rate,glycan specificity,vaccine introduction,the host immune respo-nses,and antiviral drugs.

Frequency of Rotavirus among under 5 Children Admitted to Wad Madani Pediatric Teaching Hospital with Diarrhea, Gezira State, Sudan (2021-2022)

Rotavirus is the leading cause of acute gastroenteritis and responsible for 20% of death in children under 5 years of age approximately 111 million episodes of gastroenteritis due to Rotavirus in under 5 children, which result in 25 million visits to clinic, 2 million hospitalization and 352,000 - 592,000 deaths. Children in the poorest countries account 82% of rotaviruses death. Diarrhea disease are major cause of death and disease among children under five years, a child on average suffers 2 to 3 attacks of diarrhea every year. Stools samples were collected from 196 children suffering from diarrhea and were tested for rotaviruses by immune chromatography test antigen (ICT-Ag), ELISA and RT PCR The data were analyzed using statistical package for the Social Sciences (SPSS). The results showed that prevalence of rotavirus was 26/196 (13.3%) by ICT Ag and ELISA and confirmed by RT-PC R. 87.8% of the children were vaccinated by Rota vaccine, 70% of their mothers not using soap for cleaning the children and thought diarrhea not infectious disease and believed it was caused by teething. In conclusion there was a decrease in prevalence of diarrhea by Rotavirus due to insertion of Rota vaccine in routine vaccination, rotavirus infection mostly occurs in poor family that not able to provide safe water and due to poor sanitation and low education of mother beside that some children suffered from malnutrition, so it recommended to incorporate ELISA as a diagnostic tool in routine diagnosis of rotavirus among children suffered from gastroenteritis.

Involvement of aquaporins in a mouse model of rotavirus diarrhea

Rotavirus diarrhea is a major worldwide cause of infantile gastroenteritis; however, the mechanism responsible for intestinal fluid loss remains unclear. Water transfer across the intestinal epithelial membrane seems to occur because of aquaporins(AQPs). Accumulating evidence indicates that alterations in AQPs may play an important role in pathogenesis. Here, we focus on changes in AQPs in a mouse model of rotavirus diarrhea. In the present study, 32 of 35 mice developed diarrhea and mild dehydration within 24 hours after infection with rotavirus strain SA11. Intestinal epithelial cells demonstrated cytoplasmic vacuolation, malaligned villi, and atrophy. AQP1 expression was significantly attenuated in the ileum and colon in comparison with controls; likewise, AQP4 and-8 protein expression were significantly decreased in the colon of rotavirus diarrhea-infected mice. In contrast, AQP3 protein expression was significantly increased in the colon of rotavirus-infected mice in comparison with controls. These results indicate that rotavirus diarrhea is associated with the downregulation of AQP1,-4, and-8 expression. Therefore, AQPs play an important role in rotavirus diarrhea.

Prevalence and Genotypes of Rotavirus A and Human Adenovirus among Hospitalized Children with Acute Gastroenteritis in Fujian, China, 2009-2017

Gastroenteritis is an infectious diarrhea that has been considered as an important cause of hospitalizations and death in children aged < 5 years, particularly in developing countries. Unsanitary water, contaminated food, poor hygiene, and inadequate disposal of waste and feces are all risk factors for gastroenteritis, resulting in the higher incidence in developing countries. Gastroenteritis is generally caused by viral infections, among which rotavirus (RV) infections have been reported to be the most common, especially among young children aged < 5 years with acute gastroenteritis in Asia and Africa[1]. Other viruses associated with acute gastroenteritis include human Adenovirus (HAdV), Norovirus, Sapovirus (SaV), human Astrovirus (HAstV), and Aichi virus. Recent research has reported that adenovirus types 40 and 41, belonging to species F, cause gastroenteritis and were therefore termed as enteric adenoviruses. In addition, non-enteric HAdV species such as A, B, C, and D have been associated with diarrheal.

Protein-loosing enteropathy associated with rotavirus infection in an infant

Rotavirus is an acute enteric pathogen in infants and children. We reported a rare case of a 6-mo-old infant with protein-loosing enteropathy (PLE) caused by rotavirus gastroenteritis, and evaluated the immunological profile in peripheral blood lymphocytes. Laboratory examinations showed lymphopenia, hypoproteinemia, hypoalbuminemia, hypogammaglobulinemia, and elevation of alpha-1-antitrypsin (α1-AT) clearance. Lymphocytes subpopulation study revealed the reversal of CD4+/CD8+ ratio with the selective decrease of CD4- positive lymphocytes. Moreover, the excessive increase of T cells producing IFN-gamma (IFN-γ) was found, which plays an important role in the protection against viral infection. The primary or secondary activation of immune system by rotavirus may influence structural integrity and vascular permeability, which may play a triggering role in protein-loosing enteropathy.

Lentinan administration alleviates diarrhea of rotavirus-infected weaned pigs via regulating intestinal immunity

Background:Lentinan(LNT)may regulate many important physiological functions of human and animals.This study aimed to verify whether LNT administration could relieve diarrhea via improving gut immunity in rotavirus(RV)-challenged weaned pigs.Methods:Twenty-eight weaned pigs were randomly fed 2 diets containing 0 or 84 mg/kg LNT product for 19 d(n=14).RV infection was executed on d 15.After extracting polysaccharides from LNT product,its major monosaccharides were analyzed.Then,LNT polysaccharide was used to administrate RV-infected IPEC-J2 cells.Results:Dietary LNT supplementation supported normal function of piglets even when infected with RV,as reflected by reduced growth performance loss and diarrhea prevalence,and maintained gut immunity(P<0.05).The polysaccharide was isolated from LNT product,which molecular weight was 5303 Da,and major monosaccharides included glucose,arabinose and galactose.In RV-infected IPEC-J2 cells,this polysaccharide significantly increased cell viability(P<0.05),and significantly increased anti-virus immunity via regulating pattern recognition receptors and host defense peptides(P<0.05).Conclusion:Those results suggest that LNT administration increases the piglets’resistance to RV-induced stress,likely by supporting intestinal immunity.

Acute effects of rotavirus and malnutrition on intestinal barrier function in neonatal piglets

AIM: To investigate the effect of protein-energy malnutrition on intestinal barrier function during rotavirus enteritis in a piglet model.METHODS: Newborn piglets were allotted at day 4 of age to the following treatments:(1) full-strength formula(FSF)/noninfected;(2) FSF/rotavirus infected;(3) half-strength formula(HSF)/noninfected;or(4) HSF/rotavirus infected.After one day of adjustment to the feeding rates,pigs were infected with rotavirus and acute effects on growth and diarrhea were monitored for 3 d and jejunal samples were collected for Ussingchamber analyses.RESULTS: Piglets that were malnourished or infected had lower body weights on days 2 and 3 post-infection(P < 0.05).Three days post-infection,marked diarrhea and weight loss were accompanied by sharp reductions in villus height(59%) and lactase activity(91%) and increased crypt depth(21%) in infected compared with non-infected pigs(P < 0.05).Malnutrition also increased crypt depth(21%) compared to full-fed piglets.Villus:crypt ratio was reduced(67%) with viral infection.There was a trend for reduction in transepithelial electrical resistance with rotavirus infection and malnutrition(P = 0.1).3H-mannitol flux was significantly increased(50%;P < 0.001) in rotavirus-infected piglets compared to non-infected piglets,but there was no effect of nutritional status.Furthermore,rotavirus infection reduced localization of the tight junction protein,occludin,in the cell membrane and increased localization in the cytosol.CONCLUSION: Overall,malnutrition had no additive effects to rotavirus infection on intestinal barrier function at day 3 post-infection in a neonatal piglet model.

Expression of NF-kappaB in rotavirus-induced damage to the liver and biliary tract in neonatal mice

BACKGROUND: Biliary atresia, the etiology of which still remains unclear, occurs exclusively in newborns and most are infected with rotavirus. In this study, we aimed to investigate the histopathological patterns of different kinds of rotavirus in the liver and biliary tract of neonatal mice and the expression of NF-kappa B in the liver and biliary tract of infected mice. METHODS: Twenty-three adult mice (8 were male and 15 female) were divided into 8 breeding pairs, and each pair (I male and 2 females) was housed in a cage in a laminar flow hood. Newborn mice, 24-48 hours old were randomly divided into A, B and C groups. The A and B groups were respectively inoculated with MMU18006 and SA11 rotavirus through the intraperitoneal route, while group C as blank control was only inoculated with culture medium. The liver was dissected after 5, 10, 15, 21 and 28 days; the weight of each mouse and the histopathological patterns in the liver were recorded. The expression of NF-kappa B in the liver and intrahepatic bile ducts was detected by immunohistochemical staining and the expression intensity was analyzed with a GT-2 imaging instrument. RESULTS: The average increase in weight of infected mice was significantly slower than that of the normal control, while the growth rate of group A (injected with MMU18006 rotavirus) was slower than that of group B (SA11 rotavirus). In infected mice, the acute and chronic inflammation of liver and intra- and extra-hepatic bile ducts was more significant in group A. Stenosis was found in most intrahepatic bile ducts, and sporadically in extrahepatic bile ducts. The expression of NF-kappa B in infected mice was dramatically higher than that of the normal control, while the expression in group A was higher than in group B. CONCLUSIONS: Significant damage to the liver and biliary tract of neonatal mice can be induced by inoculating MMU18006 rotavirus through the intraperitoneal route, which is very similar to the pathology of biliary atresia in the newborn human. Similar inoculation with SA11 rotavirus can only result in moderate impairment that disappears quickly. The difference of pathogenicity between the two rotaviruses may depend on their differing capacities to increase the expression of NF-kappa B in the liver and biliary tract.

Inflammatory and oxidative stress in rotavirus infection

Rotaviruses are the single leading cause of life-threatening diarrhea affecting children under 5 years of age. Rotavirus entry into the host cell seems to occur by sequential interactions between virion proteins and various cell surface molecules. The entry mechanisms seem to involve the contribution of cellular molecules having binding, chaperoning and oxido-reducing activities. It appears to be that the receptor usage and tropism of rotaviruses is determined by the species, cell line and rotavirus strain. Rotaviruses have evolved functions which can antagonize the host innate immune response, whereas are able to induce endoplasmic reticulum(ER) stress, oxidative stress and inflammatory signaling. A networking between ER stress, inflammation and oxidative stress is suggested, in which release of calcium from the ER increases the generation of mitochondrial reactive oxygen species(ROS) leading to toxic accumulation of ROS within ER and mitochondria. Sustained ER stress potentially stimulates inflammatory response through unfolded protein response pathways. However, the detailed characterization of the molecular mechanisms underpinning these rotavirus-induced stressful conditions is still lacking. The signaling events triggered by host recognition of virusassociated molecular patterns offers an opportunity for the development of novel therapeutic strategies aimed at interfering with rotavirus infection. The use of N-acetylcysteine, non-steroidal anti-inflammatory drugs and PPARγ agonists to inhibit rotavirus infection opens a new way for treating the rotavirus-induced diarrhea and complementing vaccines.

Protective effects of sodium butyrate on rotavirus inducing endoplasmic reticulum stress-mediated apoptosis via PERK-eIF2αsignaling pathway in IPEC-J2 cells

Background:Rotavirus(RV)is a major pathogen that causes severe gastroenteritis in infants and young animals.Endoplasmic reticulum(ER)stress and subsequent apoptosis play pivotal role in virus infection.However,the protective mechanisms of intestinal damage caused by RV are poorly defined,especially the molecular pathways related to enterocytes apoptosis.Thus,the aim of this study was to investigate the protective effect and mechanism of sodium butyrate(SB)on RV-induced apoptosis of IPEC-J2 cells.Results:The RV infection led to significant cell apoptosis,increased the expression levels of ER stress(ERS)markers,phosphorylated protein kinase-like ER kinase(PERK),eukaryotic initiation factor 2 alpha(eIF2α),caspase9,and caspase3.Blocking PERK pathway using specific inhibitor GSK subsequently reversed RV-induced cell apoptosis.The SB treatment significantly inhibited RV-induced ERS by decreasing the expression of glucose regulated protein 78(GRP78),PERK,and eIF2α.In addition,SB treatment restrained the ERS-mediated apoptotic pathway,as indicated by downregulation of C/EBP homologous protein(CHOP)mRNA level,as well as decreased cleaved caspase9 and caspase3 protein levels.Furthermore,siRNA-induced GPR109a knockdown significantly suppressed the protective effect of SB on RV-induced cell apoptosis.Conclusions:These results indicate that SB exerts protective effects against RV-induced cell apoptosis through inhibiting ERS mediated apoptosis by regulating PERK-eIF2αsignaling pathway via GPR109a,which provide new ideas for the prevention and control of RV.

Development of a human rotavirus induced diarrhea model in Chinese mini-pigs

AIM: to establish a new animal model for the research of human rotavirus(HRV) infection, its pathogenesis and immunity and evaluation of potential vaccines.METHODS: 5-d, 30-d and 60-d-old Chinese mini-pigs, Guizhou and bamma, were inoculated with a single oral dose of attenuated strain Wa, G1, G3 of HRV, and PbS(control), respectively, and fecal samples of pigs from 0 to 7 d post infection(DPI) were collected individually. Enzyme linked immunosorbent assay was used to detect HRV antigen in feces. the HRV was tested by real-time PCR(Rt-PCR). the sections of the intestinal tissue were stained with hematoxylin and eosin to observe the morphologic variation by microscopy. Immunofluorescence was used to determine the HRV in intestinal tissue. HRV particles in cells of the ileum were observed by electron micrography.RESULTS: When inoculated with HRV, mini-pigs younger than 30 d developed diarrhea in an agedependent manner and shed HRV antigen of the sameinoculum, as demonstrated by Rt- PCR.Histopathological changes were observed in HRV inoculated mini-pigs including small intestinal cell tumefaction and necrosis. HRV that was distributed in the small intestine was restricted to the top part of the villi on the internal wall of the ileum, which was observed by immunofluorescence and transmission electron microscopy. Virus particles were observed in Golgi like follicles in HRV-infected neonatal minipigs. Guizhou mini-pigs were more sensitive to HRV than bamma with respect to RV antigen shedding and clinical diarrhea.CONCLUSION: these results indicate that we have established a mini-pig model of HRV induced diarrhea. Our findings are useful for the understanding of the pathogenic mechanisms of HRV infection.

Effects of the viability of Lactobacillus rhamnosus GG on rotavirus infection in neonatal rats

AIM:To study the effects of live and dead Lactobacillus rhamnosus GG(GG) on rotavirus infection in a neonatal rat model.METHODS:At the age of 2 d,suckling Lewis rat pups were supplemented with either live or dead GG and the treatment was continued daily throughout the experi-ment.At the age of 5 and 6 d the pups received oral rotavirus(RV) SA-11 strain.The pups were sacrificed at the age of 7 or 8 d by decapitation.The gastrointestinal tract was removed and macroscopic observations were done.The consistency of feces in the colon was classified using a four-tier system.RV was detected from the plasma,small intestine,colon and feces by real-time quantitative polymerase chain reaction(PCR).RESULTS:In this neonatal rat model,RV induced a mild-to-moderate diarrhea in all except one pup of the RV-inoculated rats.RV moderately reduced body weight development from day 6 onwards.On day 7,after 2 d of RV infection,live and dead GG groups gained significantly more weight than the RV group without probiotics [36%(P = 0.001) and 28%(P = 0.031),respectively].In addition,when compared with the RV control group,both live and dead GG reduced the weight ratio of colon/animal body weight to the same level as in the healthy control group,with reductions of 22%(P = 0.002) and 28%(P < 0.001),respectively.Diarrhea increased moderately in both GG groups.However,the diarrhea incidence and severity in the GG groups were not statistically significantly different as compared with the RV control group.Moreover,observed diarrhea did not provoke weight loss or death.The RV control group had the largest amount of RV PCR-positive samples among the RV-infected groups,and the live GG group had the smallest amount.Rats receiving live GG had significantly less RV in the colon(P = 0.027) when compared with the RV control group.Live GG was also more effective over dead GG in reducing the quantity of RV from plasma(P = 0.047).CONCLUSION:Both live and dead GG have beneficial effects in RV infection.GG may increase RV clearance from the body and reduce colon swelling.

Epidemiological and Clinical Features of Rotavirus and Adenovirus Related Gastroenteritis in Beijing:A Retrospective Case-control Study in Pediatric Patients

Rotavirus(RV)is the most common cause of viral gastroenteritis among children younger than 5-yearold worldwide.RV has nine groups(Group A to I)and Group A(RVA)is the main cause of severe gastroenteritis disease in children.Human adenovirus(HAdV)consists of 7 species(HAdV-A through HAdV-G)including over 70 serotypes,and group F serotypes 40 and 41 are related to gastroenteritis[1].There were reports that revealed co-infection of AdV with RVA and Norovirus[2].Here we report an epidemiological and clinical analysis of RVA and AdV infection through a single-centered retrospective case-control study.

Neonatal rhesus monkeys as an animal model for rotavirus infection

AIM To establish a rotavirus(RV)-induced diarrhea model using RV SA11 in neonatal rhesus monkeys for the study of the pathogenic and immune mechanisms of RV infection and evaluation of candidate vaccines.METHODS Neonatal rhesus monkeys with an average age of 15-20 d and an average weight of 500 g ± 150 g received intragastric administration of varying doses of SA11 RV( 107 PFUs/mL, 106 PFUs/mL, or 105 PFUs/mL, 10 mL/animal) to determine whether the SA11 strain can effectively infect these animals by observing their clinical symptoms, fecal shedding of virus antigen by ELISA, distribution of RV antigen in the organs by immunofluorescence, variations of viral RNA load in the organs by qRT-PCR, histopathological changes in the small intestine by HE staining, and apoptosis of small intestinal epithelial cells by TUNEL assay.RESULTS The RV monkey model showed typical clinical diarrhea symptoms in the 108 PFUs SA11 group, where we observed diarrhea 1-4 d post infection(dpi) and viral antigen shed in the feces from 1-7 dpi. RV was found in jejunal epithelial cells. We observed a viral load of approximately 5.85 × 103 copies per 100 mg in the jejunum at 2 dpi, which was increased to 1.09 × 105 copies per 100 mg at 3 dpi. A relatively high viral load was also seen in mesenteric lymph nodes at 2 dpi and 3 dpi. The following histopathological changes were observed in the small intestine following intragastric administration of SA11 RV: vacuolization, edema, and atrophy. Apoptosis in the jejunal villus epithelium was also detectable at 3 dpi.CONCLUSION Our results indicate that we have successfully established a RV SA11 strain diarrhea model in neonatal rhesus monkeys. Future studies will elucidate the mechanisms underlying the pathogenesis of RV infection, and we will use the model to evaluate the protective effect of candidate vaccines.

EXPRESSION AND GLYCOSYLATION OF ROTAVIRUS STRAIN SA11 VP4 PROTEIN IN A RECOMBINANT ADENOVIRUS

Objective. Using a recombinant human adenovirus to express modified VP4 gene of rotavirus SA11 strain. Methods. A whole VP4 gene was obtained with PCR and induced the signal peptide at the gene N terminal. The chimera gene was cloned into pCMV plasmid that consists of human cytomegalovirus promoter, and then the gene was cloned to the transfer vector of human adenovirus type 5. Homologous recombination was performed by co- transfection to 293 cell lines with recombinant plasmid and viral genome using CaPO4 precipitation. Results. No mutation was found in the whole VP4 gene sequence of 2362 base pair. The expressed product in recombinant adenovirus was confirmed to be specific and more antigenicity by indirect immunofluorescence assay. Both the Western blot and immunoprecipitation assay showed that the molecular mass of the expressed protein was higher than the wild type VP4 protein, and that the modified product was corresponding to a glycosylation of VP4 protein. Conclusion. To modify the target gene might be an effective method to enhance the stability, antigenicity and immunogenicity of expressed protein.

Molecular characterization of VP4,VP6,VP7 and NSP4 genes of group B rotavirus strains from outbreaks of gastroenteritis

Objective:To characterize VP4,VP6,VP7 and NSP4 genes of representative GBR strains(NIV- 005625.MV-04622 and NIV-094456) delected as the major eliolngic agenl in the outbreaks of gastroenteritis in western India.Methods:Fecal specimens collected during the outbreaks of gastroenteritis were processed for RNA isolation.RT-PCR using GBR VP4.VP6.VP7 and NSP4 gene specific primers,nucleotide sequencing of the amplicons and phylogenetic analysis of the sequences.Results:Phylogenetic analysis of all of the VP4.VP6.VP7 and NSP4 gene sequences revealed clustering of GBR strains in Indian-Bangladeshi lineage of genotype G2 with 95.8%- 99.4%nucleotide and 97.3%-100.0%amino acid identities.However,all three strains showed the presence of unique amino acid substitutions in the VP4 protein suggesting alteration in the antigenicity of outbreak strains of GBR.The VP8* and VP5* regions of VP4 proteins showed respectively 0.5%-6.3%and 0.2%-1.1%amino acid divergence from human GBR strains of Indian-Bangladeshi lineage.Conclusions:These data confirm the reported variability of VP8* region and suggest the possible role of this region in the perpetuation of GBR infections in the environment.This is the first study to document the phylogenetic relationship of VP4,VP6.VP7 and NSP4 genes of GBR strains detected in the outbreaks of gastroenteritis from India with the CBR strains from other parts of world.