Rotavirus infection and the current status of rotavirus vaccines

Spray-dried plasma protects against rotavirus-induced gastroenteritis via regulating macrophage and T cells divergence in weanling pigs

Infectious gastroenteritis is the major cause for diarrhea in piglets. The protection of spray-dried plasma (SDP) on viral gastroenteritis during the progression of rotavirus (RV) infection remain unclear. In this study, 64 weanling piglets were randomly assigned to control diets (n = 40) and SDP diets (n = 24) for 14 days, and then pigs were challenged with RV on day 15. Pigs were sacrificed on day 14 (normal condition), day 18 (manifestation stage), and day 21 (convalescent stage) of the trial. Prior to RV infection, SDP increased ADG, M1 macrophages and CD4+ T cells in different organs without increasing proinflammatory cytokines, indicating a more robust immunity with less inflammation. During the manifestation of infection, SDP enhanced mucosal immunity by increasing M1 macrophages, M1/M2 ratio and cytokines in mucosa and increasing intraepithelial CD8+ T cells for RV clearance. During the convalescence, SDP promoted M2 macrophage polarization and reduced pro-inflammatory cytokines to facilitate intestinal repair and prevent prolonged inflammation. Collectively, SDP enhanced mucosal immunity to promote viral clearance and maintained immune homeostasis to prevent long-lasting inflammation as a therapeutically approach for infectious gastroenteritis.

Epidemiology of group A rotavirus in children under five years of age with gastroenteritis in N'Djamena, Chad

BACKGROUND

Group A Rotaviruses (RVA) is one of the most common causes of severe diarrhoea in infants and children under 5 years of age. Unlike many countries in the world where RVA surveillance/control is active, in Chad , there is currently no applied RVA immunization program and surveillance strategy. The present study aims to determine the prevalence and associated risk factors of RVA gastroenteritis among children under five years of age in N'Djamena.

METHOD

This study comprised two parts: (1) A cross-sectional study carried in four hospitals in N'Djamena between August and November 2019, to determine infection risk factors and evidence of RVA infection among children aged five and below, consulted or hospitalized for diarrhea. An ELISA based RVA VP6 protein detection was used to determine RVA infection prevalence. Infection results and sociodemographic data were statistically analysed to determine RVA infection risk factors. (2) A retrospective study that consisted of analysing the records of stool examinations of the period from January 2016 to December 2018, to determine the prevalence of infectious gastroenteritis among the target population.

RESULTS

For the cross-sectional study, RVA infection prevalence was 12.76% (18/141) with males (61.11%) being more affected (sex ratio: 1.57). Children below 12 months were the most affected age group (44.44%) and 44.4% were malnourished. The mean Vesikari score shows that 38.8% of children have a high severity level and 41.1% have a moderate level. For the retrospective study, 2,592 cases of gastroenteritis hospitalization were analysed; 980 out of 2,592 cases (37.81%) of hospitalization due to diarrhoea were due to diarrhoeagenic pathogens including Emtamoeba hystolitica, Gardia lamblia, Trichomonas hominis, Hymenolepis nana, Escherichia coli, Shigella spp, Proteus mirabilis, and Klebsiella oxytoca. Cases of diarrhoea with negative pathogen search were 1,612 cases (62.19%). The diarrhoea peak was observed during the dry seasons, and the age group under 11 months was the most affected was (57.3%).

CONCLUSION

This study describes the evidence of RVA infection among diarrhoeic children below five years of age in N'Djamena, thus indicates a serious health burden. Malnourishment younger age was the higher risk factor. Further studies are needed to determine the circulating strains prior to considering introduction of RVA vaccine and setup a routine rotavirus surveillance in Chad.

Established and new rotavirus vaccines: a comprehensive review for healthcare professionals

Robust scientific evidence related to two rotavirus (RV) vaccines available worldwide demonstrates their significant impact on RV disease burden. Improving RV vaccination coverage may result in better RV disease control. To make RV vaccination accessible to all eligible children worldwide and improve vaccine effectiveness in high-mortality settings, research into new RV vaccines continues. Although current and in-development RV vaccines differ in vaccine design, their common goal is the reduction of RV disease risk in children <5 years old for whom disease burden is the most significant. Given the range of RV vaccines available, informed decision-making is essential regarding the choice of vaccine for immunization. This review aims to describe the landscape of current and new RV vaccines, providing context for the assessment of their similarities and differences. As data for new vaccines are limited, future investigations will be required to evaluate their performance/added value in a real-world setting.

Potential zoonotic swine enteric viruses: The risk ignored for public health

Swine could serve as a natural reservoir for a large variety of viruses, including potential zoonotic enteric viruses. The presence of viruses with high genetic similarity between porcine and human strains may result in the emergence of zoonotic or xenozoonotic infections. Furthermore, the globalization and intensification of swine industries exacerbate the transmission and evolution of zoonotic viruses among swine herds and individuals working in swine-related occupations. To effectively prevent the public health risks posed by zoonotic swine enteric viruses, designing, and implementing a comprehensive measure for early diagnosis, prevention, and mitigation, requires interdisciplinary a collaborative ''One Health" approach from veterinarians, environmental and public health professionals, and the swine industry. In this paper, we reviewed the current knowledge of selected potential zoonotic swine enteric viruses and explored swine intensive production and its associated public health risks.

iTRAQ-based proteome analysis of porcine group A rotavirus-infected porcine IPEC-J2 intestinal epithelial cells

Porcine rotavirus (PoRV), particularly group A, is one of the most important swine pathogens, causing substantial economic losses in the animal husbandry industry. To improve understanding of host responses to PoRV infection, we applied isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantitatively identify the differentially expressed proteins in PoRV-infected IPEC-J2 cells and confirmed the differentially accumulated proteins (DAPs) expression differences by performing RT-qPCR and Western blot analysis. Herein, in PoRV- and mock-infected IPEC-J2 cells, relative quantitative data were identified for 4724 proteins, 223 of which were DAPs (125 up-accumulated and 98 down-accumulated). Bioinformatics analyses further revealed that a majority of the DAPs are involved in numerous crucial biological processes and signaling pathways, such as metabolic process, immune system process, amino acid metabolism, energy metabolism, immune system, MHC class I peptide loading complex, Hippo signaling pathway, Th1 and Th2 cell differentiation, antigen processing and presentation, and tubule bicarbonate reclamation. The cellular localization prediction analysis indicated that these DAPs may be located in the Golgi apparatus, nucleus, peroxisomal, cytoplasm, mitochondria, extracellular, plasma membrane, and endoplasmic reticulum (ER). Expression levels of three up-accumulated (VAMP4, IKBKE, and TJP3) or two down-accumulated (SOD3 and DHX9) DAPs upon PoRV infection, were further validated by RT-qPCR and Western blot analysis. Collectively, this work is the first time to investigate the protein profile of PoRV-infected IPEC-J2 cells using quantitative proteomics; these findings provide valuable information to better understand the mechanisms underlying the host responses to PoRV infection in piglets. SIGNIFICANCE: The proteomics analysis of this study uncovered the target associated with PoRV-induced innate immune response or cellular damage, and provided relevant insights into the molecular functions, biological processes, and signaling pathway in these targets. Out of these 223 DAPs, the expression levels of three up-accumulated (VAMP4, IKBKE, and TJP3) and two down-accumulated (SOD3 and DHX9) DAPs upon PoRV infection, have been further validated using RT-qPCR and Western blot analysis. These outcomes could uncover how PoRV manipulated the cellular machinery, which could further our understanding of PoRV pathogenesis in piglets.

The Long-Term Impact of Rotavirus Vaccines in Korea, 2008-2020; Emergence of G8P[8] Strain

This study evaluated the long-term impact of rotavirus vaccination on prevalence, seasonality, and genotype distribution in Gwangju, Korea for 13 seasons. Rotavirus was identified using ELISA and then sequenced for G and P genotypes by Reverse Transcription Polymerase Chain Reactions for diarrhoeagenic patient specimens from local hospitals between January 2008 and August2020. Of 26,902 fecal samples, 2919 samples (10.9%) were ELISA positive. The prevalence declined from 16.3% in pre-vaccine era to 5.4% in post-vaccine era. In the pre-vaccine period, G1P[8] was the most common genotype, followed by G2P[4], G3P[8], and G9P[8], etc. In the transitional period, the proportion of G2P[4] became the dominant genotype and G1P[8] was still commonly identified. In contrast, the novel genotype G8P[8] was predominant in the post-vaccine period. Meanwhile, G2P[4] and G8P[8] were major genotypes in both Rotarix and RotaTeq groups. The substantial decline of G1P[8] prevalence, reemergence of G1P[8], G3P[8], and G2P[4] rotavirus strains, and surge of the rare G8P[8] after vaccine introduction were interesting points to note. The continuous surveillance on the genotypes of RV will be needed to understand rotavirus epidemiology and their evolutionary patterns, as caution is required when interpreting temporal changes in RV genotype dynamic.

Rotavirus infection induces glycan availability to promote ileum-specific changes in the microbiome aiding rotavirus virulence

Multiple studies have identified changes within the gut microbiome in response to diarrheal-inducing bacterial pathogens. However, examination of the microbiome in response to viral pathogens remains understudied. Compounding this, many studies use fecal samples to assess microbiome composition; which may not accurately mirror changes within the small intestine, the primary site for most enteric virus infections. As a result, the functional significance of small intestinal microbiome shifts during infection is not well defined. To address these gaps, rotavirus-infected neonatal mice were examined for changes in bacterial community dynamics, host gene expression, and tissue recovery during infection. Profiling bacterial communities using 16S rRNA sequencing suggested significant and distinct changes in ileal communities in response to rotavirus infection, with no significant changes for other gastrointestinal (GI) compartments. At 1-d post-infection, we observed a loss in Lactobacillus species from the ileum, but an increase in Bacteroides and Akkermansia, both of which exhibit mucin-digesting capabilities. Concomitant with the bacterial community shifts, we observed a loss of mucin-filled goblet cells in the small intestine at d 1, with recovery occurring by d 3. Rotavirus infection of mucin-producing cell lines and human intestinal enteroids (HIEs) stimulated release of stored mucin granules, similar to in vivo findings. In vitro, incubation of mucins with Bacteroides or Akkermansia members resulted in significant glycan degradation, which altered the binding capacity of rotavirus in silico and in vitro. Taken together, these data suggest that the response to and recovery from rotavirus-diarrhea is unique between sub-compartments of the GI tract and may be influenced by mucin-degrading microbes.

Clinical and Environmental Surveillance of Rotavirus Common Genotypes Showed High Prevalence of Common P Genotypes in Egypt

The objective of this study was to compare the prevalence of human rotavirus group A common G and P genotypes in human Egyptian stool specimens and raw sewage samples to determine the most common genotypes for future vaccine development. From 1026 stool specimens of children with acute diarrhea and using nested RT-PCR, 250 samples (24.37%) were positive for human rotavirus group A. Using multiplex RT-PCR, rotavirus common P and G genotypes were detected as 89.20% and 46.40% of the positive clinical specimens respectively. This low percentage of common G genotypes frequency may affect the efficiency of the available live attenuated oral rotavirus vaccines [Rotarix® (human rotavirus G1P[8]) and RotaTeq® (reassortant bovine-human rotavirus G1-4P[5] and G6P[8])], however the percentage of clinical specimens which were negative for common G genotypes but positive for P[8] genotype was 12.00%. From 24 positive raw sewage samples for rotavirus group A VP6 collected from Zenin and El-Gabal El-Asfar wastewater treatment plants (WWTPs), 21 samples (87.50%) were typeable for common P genotypes while 13 samples (54.17%) were typeable for common G genotypes. Phylogenetic analysis of a VP8 partial gene of 45 P-typeable clinical isolates and 20 P-typeable raw sewage samples showed high similarity to reference strains and the majority of mutations were silent and showed lower to non-significant similarity with the two vaccine strains. This finding is useful for determining the most common antigens required for future vaccine development.

Rotavirus and Cryptosporidium pathogens as etiological proxies of gastroenteritis in some pastoral communities of the Amathole District Municipality, Eastern Cape, South Africa

Objective

Cryptosporidium and Rotavirus agents have been associated with severe diarrheal illnesses and remain as one of the worst human health burdens in most developing regions. In the present study, we evaluated the incidences of Cryptosporidium and Rotavirus in diarrheal stool specimens of patients in some rural settlements of the Amathole District Municipality in the Eastern Cape Province, South Africa. Stool specimens from diarrheal children and elderly individuals were collected from clinics and hospitals within the rural communities of the region over a period of 21 months (February 2017–November 2018). Commercial enzyme-immuno-assays were used for the detection of Rotavirus and Cryptosporidium pathogens from processed diarrheal stool specimens.

Results

A total of 53 fresh stool samples from diarrheal patients were screened and 36% of the diarrheagenic stool specimens tested positive for Group A Rotavirus antigens, while 5.7% tested positive for Cryptosporidium antigens. Our findings reveal Rotavirus and Cryptosporidium pathogens as important etiological agents associated with diarrheal illnesses in children, among the rural hinterlands of the Amathole District Municipality.

Vaccines the tugboat for prevention-based animal production

The world population is growing at a faster rate day-by-day and the demands for animal products are also increasing to meet the food security worldwide. For sustained production of animals products, healthy livestock and poultry farming are the major concerns as animals are susceptible to various infectious agents viz. bacteria, virus, and parasites leading to huge economical losses in the form of livestock’s morbidity and mortality. Besides, zoonotic nature of some infectious pathogens of animals is also raising concern for human safety. Vaccination of animals against various diseases present in different geographical regions is a best known strategy for prevention of different disease outbreaks both in organized and unorganized livestock and poultry sectors. Vaccines had played a major role in eradication of different dreaded diseases of livestock sectors globally. In this article we have discussed different vaccine types, various vaccine strategies used for the development of more efficacious and safe vaccines and commercially available vaccines for livestock and poultry.

Emergence of rotavirus G9 in 2012, as the dominant genotype in Turkish children with diarrhea, in a university hospital in Ankara

Introduction: Rotavirus infection is a major cause of morbidity and mortality in infants and young children with diarrhea throughout the world.

Material and Methods: In this study, we aimed to determine the detection rate of rotavirus infection in 181 children less than 5 years of age presenting with acute gastroenteritis and admitted to a tertiary care hospital in Ankara, Turkey, from April to November 2012. We documented the epidemiological data by elucidating the prevalent genotypes. Stool specimens were collected, and rotavirus antigen in the samples was detected using ELISA. G and P genotypes were determined by RT-PCR via type specific primers. The nucleotide sequence of the concerned genes was determined by Sanger sequencing and phylogenetic analysis was performed by neighbor-joining method.

Results: Of the 181 samples, 28 (15.5%) were positive for the rotavirus antigen. Twenty-seven samples were positive for G genotypes and 21 were positive for P genotypes. Genotypes G1 (7.1%), G2 (7.1%), G3 (7.1%), G4 (3.6%), G9 (71.5%) and P4 (3.6%), P8 (71.4%) were identified. Genotype G9P[8] (50%) was predominant in the combination of G and P genotypes. Most of the G9 strains of this study formed an independent cluster in Lineage III, except two strains which clustered with an Ethiopian G9 strain of 2012.

Conclusions: It seems that during 2012 season, genotype G9P[8] increased significantly in Ankara due to a new circulating strain of G9.

Rotavirus Double Infection Model to Study Preventive Dietary Interventions

Rotaviruses are the main cause of acute diarrhea among young children worldwide with an increased frequency of reinfection. Several life style factors, such as dietary components, may influence such processes by affecting the outcome of the first rotavirus infection and therefore having a beneficial impact on the anti-rotavirus immune responses during any subsequent reinfections. The aim of this research was to develop a double-infection model in rat that mimics real-life clinical scenarios and would be useful in testing whether nutritional compounds can modulate the rotavirus-associated disease and immune response. Three experimental designs and a preventive dietary-like intervention were conducted in order to achieve a differential response in the double-infected animals compared to the single-infected ones and to study the potential action of a modulatory agent in early life. Diarrhea was only observed after the first infection, with a reduction of fecal pH and fever. After the second infection an increase in body temperature was also found. The immune response against the second infection was regulated by the preventive effect of the dietary-like intervention during the first infection in terms of specific antibodies and DTH. A rotavirus-double-infection rat model has been developed and is suitable for use in future preventive dietary intervention studies.

Bifidobacterium adolescentis (DSM 20083) and Lactobacillus casei (Lafti L26-DSL): Probiotics Able to Block the In Vitro Adherence of Rotavirus in MA104 Cells

Rotavirus is the leading worldwide cause of gastroenteritis in children under five years of age. Even though there are some available vaccines to prevent the disease, there are limited strategies for challenging diarrhea induced by rotavirus infection. For this reason, researchers are constantly searching for other approaches to control diarrhea by means of probiotics. In order to demonstrate the ability of some probiotic bacteria to interfere with the in vitro rotavirus infection in MA104 cells, strains of Lactobacillus sp. and Bifidobacterium sp. were tested in MA104 cells before the viral infection. As a preliminary assay, a blocking effect treatment was performed with viable bacteria. In this screening assay, four of initial ten bacteria showed a slight reduction of the viral infection (measured by percentage of infection). L. casei (Lafti L26-DSL), L. fermentum(ATCC 9338), B. adolescentis (DSM 20083), and B. bifidum (ATCC 11863) were used in further experiments. Three different treatments were tested in order to evaluate protein-based metabolites obtained from mentioned bacteria: (i) cell exposure to the protein-based metabolites before viral infection, (ii) exposure to protein-based metabolites after viral infection, and (iii) co-incubation of the virus and protein-based metabolites before viral infection to the cell culture. The best effect performed by protein-based metabolites was observed during the co-incubation assay of the virus and protein-based metabolites before adding them into the cell culture. The results showed 25 and 37% of infection in the presence of L. casei and B. adolescentis respectively. These results suggest that the antiviral effect may be occurring directly with the viral particle instead of making a blocking effect of the cellular receptors that are needed for the viral entrance.

Rotavirus Vaccination and the Global Burden of Rotavirus Diarrhea Among Children Younger Than 5 Years

IMPORTANCE

Rotavirus infection is the global leading cause of diarrhea-associated morbidity and mortality among children younger than 5 years.

OBJECTIVES

To examine the extent of rotavirus infection among children younger than 5 years by country and the number of deaths averted because of the rotavirus vaccine.

DESIGN, SETTING, AND PARTICIPANTS

This report builds on findings from the Global Burden of Disease Study 2016, a cross-sectional study that measured diarrheal diseases and their etiologic agents. Models were used to estimate burden in data-sparse locations.

EXPOSURE

Diarrhea due to rotavirus infection.

MAIN OUTCOMES AND MEASURES

Rotavirus-associated mortality and morbidity by country and year and averted deaths attributable to the rotavirus vaccine by country.

RESULTS

Rotavirus infection was responsible for an estimated 128 500 deaths (95% uncertainty interval [UI], 104 500-155 600) among children younger than 5 years throughout the world in 2016, with 104 733 deaths occurring in sub-Saharan Africa (95% UI, 83 406-128 842). Rotavirus infection was responsible for more than 258 million episodes of diarrhea among children younger than 5 years in 2016 (95% UI, 193 million to 341 million), an incidence of 0.42 cases per child-year (95% UI, 0.30-0.53). Vaccine use is estimated to have averted more than 28 000 deaths (95% UI, 14 600-46 700) among children younger than 5 years, and expanded use of the rotavirus vaccine, particularly in sub-Saharan Africa, could have prevented approximately 20% of all deaths attributable to diarrhea among children younger than 5 years.

CONCLUSIONS AND RELEVANCE

Rotavirus-associated mortality has decreased markedly over time in part because of the introduction of the rotavirus vaccine. This study suggests that prioritizing vaccine introduction and interventions to reduce diarrhea-associated morbidity and mortality is necessary in the continued global reduction of rotavirus infection.

Preventive Effect of a Synbiotic Combination of Galacto- and Fructooligosaccharides Mixture With Bifidobacterium breve M-16V in a Model of Multiple Rotavirus Infections

Rotavirus (RV) causes morbidity and mortality among infants worldwide, and there is evidence that probiotics and prebiotics can have a positive influence against infective processes such as that due to RV. The aim of this study was to evidence a preventive role of one prebiotic mixture (of short-chain galactooligosaccharide/long-chain fructooligosaccharide), the probiotic Bifidobacterium breve M-16V and the combination of the prebiotic and the probiotic, as a synbiotic, in a suckling rat double-RV infection model. Hyperimmune bovine colostrum was used as protection control. The first infection was induced with RV SA11 and the second one with EDIM. Clinical variables and immune response were evaluated after both infections. Dietary interventions ameliorated clinical symptoms after the first infection. The prebiotic and the synbiotic significantly reduced viral shedding after the first infection, but all the interventions showed higher viral load than in the RV group after the second infection. All interventions modulated ex vivo antibody and cytokine production, gut wash cytokine levels and small intestine gene expression after both infections. In conclusion, a daily supplement of the products tested in this preclinical model is highly effective in preventing RV-induced diarrhea but allowing the boost of the early immune response for a future immune response against reinfection, suggesting that these components may be potential agents for modulating RV infection in infants.

Prevalence and genotypes of Rotavirus among children under 5 years presenting with diarrhoea in Moshi, Tanzania: a hospital based cross sectional study

Background

Diarrhoea is a main cause of morbidity and mortality in children under 5 responsible for approximately four billion cases and 1.1 million deaths annually. In developing countries, it causes two million deaths each year. The major causative organism responsible is Rotavirus which is responsible for one-third of hospitalizations with approximately 40% mortality.

Results

The prevalence of Rotavirus infection was 26.4% (73/277). The predominant strain of Rotavirus found was G1 21/73 (53.8%), followed by G8 9/73 (23.1%), G12 5/73 (12.8%), G9 3/73(7.7%) and G4 1/73 (2.6%). All serotypes identified were in children who had completed Rotavirus vaccination except for one who had G8 in whom the vaccine was introduced after they had completed immunizations.

Conclusion

The overall prevalence of rotavirus has reduced from 33.2% in 2009 to 26.4% in 2016. We have found G1 to be the predominant serotype as well as other circulating serotypes namely G4, G8, G9 and G12. Despite a reduction in prevalence, there is a need for further rotavirus surveillance in the region.

Electronic supplementary material

The online version of this article (10.1186/s13104-017-2883-3) contains supplementary material, which is available to authorized users.

Update on the epidemiology of rotavirus in the Middle East and North Africa

Rotavirus (RV) is the leading cause of severe acute gastroenteritis (AGE) worldwide. Consequently, we conducted a systematic literature review on articles studying RV in the 25 countries of the MENA region during the past 15years (2000-2015). The methods and reporting were set according to the 2015 preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) and based on the elements from the international prospective register of systematic reviews (PROSPERO). Our literature search identified 169 studies meeting our predefined inclusion criteria. Studies reporting on RV were conducted in 19 out of the 24 countries of the MENA region. The largest number of studies was reported in Turkey (n=32), Iran (n=31), Saudi Arabia (n=19) and Egypt (n=17). The majority of studies reporting on RV gastroenteritis rates were clinical observational studies. In 115 studies out of 169, RV was reported among in-patients whereas 35 studies reported RV among outpatients. The predominantly reported RV genotype in the region was G1[P8] followed by G2[P4] and G9[P8]. The majority of studies (n=108) were conducted among children less than 5years of age whereas the remaining studies reported on AGE among other age groups and rarely adults. In MENA countries, RV infection was reported all year round with peaks described in cold as well as hot months. This systematic review provides a current update on the epidemiology of RV-associated gastroenteritis in countries of the MENA region and draws attention to the major gaps existing in the continuous monitoring of RV.

Detection of Acute Gastroenteritis Etiology in Hospitalized Young Children: Associated Factors and Outcomes

BACKGROUND

The decision to test for the etiology of diarrhea is a challenging question for practicing pediatricians.

METHODS

The main goal of this retrospective cohort study was to identify factors associated with testing for and diagnosis of rotavirus, Clostridium difficile, or other bacterial infections, as well as the length of stay (LOS) for children with acute gastroenteritis who were hospitalized at a single institution. Patients aged 6 to 60 months with acute diarrhea (<14 days) and no underlying gastrointestinal conditions were included. Data were analyzed by using multivariate logistic and linear regression models.

RESULTS

Stool testing was performed in 73.1% of the 331 patients studied. The majority were tested for multiple pathogens, including rotavirus (65.9%), C difficile (30.8%), and other bacteria (63.4%), with recovery rates of 33.0%, 9.8%, and 6.7%, respectively. Rotavirus was more often identified in older patients with dehydration and vomiting. Although testing for C difficile was more likely with prolonged diarrhea, no vomiting, and recent antibiotic use, no factors were associated with C difficile recovery. Patients who were diagnosed with C difficile were more likely to receive probiotics than those who received negative test results. LOS was not associated with stool testing or recovery of any tested pathogens.

CONCLUSIONS

Although children with acute gastroenteritis underwent frequent stool testing for diarrheal etiology, detection of a pathogen was uncommon and not associated with a change in LOS. Experimental research will be needed to make additional conclusions about the efficacy of testing for diarrheal etiology in the inpatient practice of acute pediatric diarrhea.

Detailed analysis of BALB/c mice challenged with wild type rotavirus EDIM provide an alternative for infection model of rotavirus

Mouse is one of the infection animal models for rotavirus. Since the optimal age of mouse sensitive to rotavirus infection thus far has not been unified, we elucidated clinical symptoms, immune responses and pathological changes of mice in different ages after challenged by murine rotavirus wild strain EDIM (Epidemic Diarrhea of Infant Mice) to provide data for the estimation. One-week-old, two-week-old, and three-week-old BALB/c mice were inoculated with EDIM in the challenge dose of 235 ID50, 470 ID50 and 705 ID50 respectively and were compared to mock-infected controls. Diarrhea illness, mobility, bodyweight were recorded, viral shedding and immune responses including serum IgA, fecal sIgA were detected, and small intestine tissue was evaluated for virus distribution and pathological changes. All the mice in one-week-old and two-week-old groups were completely unavoidable to be infected by EDIM and have been found to be malaise, activity reduced and even diarrhea, while three-week-old mice partly resist the challenge with 40% mice free from diarrhea. Meanwhile, EDIM infection has greater impact to the bodyweight of two-week-old group than those of one-week-old, three-week-old (0.9860 vs 1.2340, 1.2375g/day). One peak of virus shedding in three groups was observed in day 1-2 post infection, but the duration shortened with age increase. Feces sIgA in both two-week-old and three-week-old groups began to increase in day 4, 2-3days earlier than that in one-week-old group, and grow to the peak in day 8, which is about 2 fold of that in one-week-old group. Stronger serum IgA response was found in two-week-old group, it increased to the peak in day 15 and the level was 2 fold of three-week-old group and 4 fold of one-week-old group. The pathological changes included vacuolar degeneration, edema and congestion of intestinal wall, integrity destruction of enteric epithelium, and the changes relieved with the increase of age. Besides, rotavirus particles were found in small intestine tissues, especially in the surface and crypt of villi. In conclusion, the two-week-old mice were more sensitive to EDIM infection and initiated more effective immune response. In combination with that 14days old mice equals to 2 months infant when the first dose of rotavirus vaccine should be administrated, two-week-old mice is preferred to be used as infection model for the study of pathogenicity and immunogenicity of rotavirus.

The prevalence and genotype distribution of rotavirus A infection among children with acute gastroenteritis in Kunming, China

The aim of this study was to determine the prevalence of rotavirus A (RVA) infections in children from Kunming, China, and the RVA genotypes present. A total of 16,311 children with acute gastroenteritis were recruited for the study, and 33.1 % (5,394/16,311) were RVA positive. Children under 24 months of age were more susceptible to RVA infection, with an infection rate of 87.4 % (4,712/5,394). The most prevalent genotype was G9P[8] (85/107, 79.4 %), which showed high sequence similarity to G9P[8] strains from other regions of China and neighbouring countries, but not to the licensed vaccine strain LLR. These findings should be useful for the prevention of RVA infections.

Effects of lactadherin on plasma D-lactic acid and small intestinal MUC2 and claudin-1 expression levels in rats with rotavirus-induced diarrhea

The aim of the present study was to investigate the effects of lactadherin on plasma D-lactic acid and small intestinal mucin (MUC) 2 and claudin-1 expression levels in rats with diarrhea induced by rotavirus (RV) infection. A total of 75 seven-day-old healthy Sprague-Dawley rats were randomly divided into the following five groups: Control (C), RV infection (RVI), lactadherin before rotavirus infection (LBRI), lactadherin after rotavirus infection (LARI), and blank (B). On day 4 of artificial feeding, the rats in groups RVI, LBRI and LARI were intragastric administered 1×106 PFU RV; whereas the rats in groups C and B were intragastrically administered an equal volume of maintenance solution from the RV supernatant and normal saline, respectively. In the LBRI and LARI groups, rats received daily intragastric administration of 0.25 mg lactadherin for three days prior to and following infection with RV, respectively. The course of diarrheal symptoms was observed in each group and samples were collected on days 1, 4, and 7 post-infection in order to determine the mucosal morphology, plasma D-lactic acid levels and the expression levels of MUC2 and the intracellular junction protein, claudin-1, in the small intestine. On day 4 post-infection, the rats in group RVI demonstrated severely damaged small intestines and typical diarrheal characteristics, as detected by light microscopy; whereas rats in groups LBRI and LARI demonstrated intact small intestinal villi with partial vacuolation of epithelial cells and changes in the position of their nuclei. Electron microscopy demonstrated that the rats in the RVI group had sparse, shortened, disordered intestinal microvilli and widened intercellular junctions; whereas those in groups LBRI and LARI had long intestinal microvilli sparser compared with groups B and C and slightly widened intercellular junctions. Plasma D-lactic acid levels were increased in groups RVI, LBRI and LARI, as compared with groups B and C, and the greatest levels were detected in the RVI group on days 1, 4 and 7 post-infection. In addition to maintaining intestinal permeability, lactadherin enhanced the expression levels of MUC2 and reduced the expression of claudin-1; therefore, further protecting the intestinal epithelial barrier, which may contribute to the prevention and treatment of diarrhea induced by infection with RV.

Antiviral effects of Lactobacillus ruminis SPM0211 and Bifidobacterium longum SPM1205 and SPM1206 on rotavirus-infected Caco-2 cells and a neonatal mouse model

Rotavirus is worldwide cause of severe gastroenteritis including severe diarrhea and fatal dehydration in infants and young children. There is an available vaccination program for preventing rotavirus infection, but it has limits and restrictions. Probiotics therapy could be an alternative method of antiviral prevention and modulation against rotavirus infection. In this study, we screened the antiviral activity of probiotic bacteria such as 3 Lactobacillus spp. and 14 Bifidobacterium spp. isolated from young Korean. Three of the bacteria, Lactobacillus ruminis SPM0211, Bifidobacterium longum SPM1205, and SPM1206, inhibited human strain Wa rotavirus infection in Caco-2 cells. Furthermore, these bacterial strains inhibited rotavirus replication in a rotavirus-infected neonatal mouse model. To clarify the mechanism of inhibition, we investigated gene expression of Interferon (IFN)-signaling components and IFN-inducible antiviral effectors. All 3 probiotics increased IFN-α and IFN-β levels compared with the control. Gene expression of IFNsignaling components and IFN-inducible antiviral effectors also increased. Overall, these results indicate that L. ruminis SPM0211, B. longum SPM1205 and 1206 efficiently inhibit rotavirus replication in vitro and in vivo. Especially, the antiviral effect of Lactobacillus ruminis SPM0211 is worthy of notice. This is the first report of L. ruminis with antiviral activity. Anti-rotaviral effects of the 3 probiotics are likely due to their modulation of the immune response through promoting type I IFNs, which are key regulators in IFN signaling pathway.

Comparative In Vitro and In Vivo Studies of Porcine Rotavirus G9P[13] and Human Rotavirus Wa G1P[8]

The changing epidemiology of group A rotavirus (RV) strains in humans and swine, including emerging G9 strains, poses new challenges to current vaccines. In this study, we comparatively assessed the pathogenesis of porcine RV (PRV) G9P[13] and evaluated the short-term cross-protection between this strain and human RV (HRV) Wa G1P[8] in gnotobiotic pigs. Complete genome sequencing demonstrated that PRV G9P[13] possessed a human-like G9 VP7 genotype but shared higher overall nucleotide identity with historic PRV strains. PRV G9P[13] induced longer rectal virus shedding and RV RNAemia in pigs than HRV Wa G1P[8] and generated complete short-term cross-protection in pigs challenged with HRV or PRV, whereas HRV Wa G1P[8] induced only partial protection against PRV challenge. Moreover, PRV G9P[13] replicated more extensively in porcine monocyte-derived dendritic cells (MoDCs) than did HRV Wa G1P[8]. Cross-protection was likely not dependent on serum virus-neutralizing (VN) antibodies, as the heterologous VN antibody titers in the sera of G9P[13]-inoculated pigs were low. Thus, our results suggest that heterologous protection by the current monovalent G1P[8] HRV vaccine against emerging G9 strains should be evaluated in clinical and experimental studies to prevent further dissemination of G9 strains. Differences in the pathogenesis of these two strains may be partially attributable to their variable abilities to replicate and persist in porcine immune cells, including dendritic cells (DCs). Additional studies are needed to evaluate the emerging G9 strains as potential vaccine candidates and to test the susceptibility of various immune cells to infection by G9 and other common HRV/PRV genotypes.

IMPORTANCE

The changing epidemiology of porcine and human group A rotaviruses (RVs), including emerging G9 strains, may compromise the efficacy of current vaccines. An understanding of the pathogenesis and genetic, immunological, and biological features of the new emerging RV strains will contribute to the development of new surveillance and prevention tools. Additionally, studies of cross-protection between the newly identified emerging G9 porcine RV strains and a human G1 RV vaccine strain in a susceptible host (swine) will allow evaluation of G9 strains as potential novel vaccine candidates to be included in porcine or human vaccines.

Detection of rotavirus and other enteropathogens in children hospitalized with acute gastroenteritis in Havana, Cuba

The aim of the study was to diagnose infections with rotavirus and other enteric pathogens in children under five years old with acute gastroenteritis and to identify the most common epidemiological and clinical characteristics of these pathogens. The study was conducted using 110 stool samples from the same number of children under five years old who were inpatients at three paediatric hospitals in Havana, Cuba, between October and December 2011. The samples were tested for rotavirus and other enteric pathogens using traditional and molecular microbiological methods. Pathogens were detected in 85 (77.3 %) of the children. Rotavirus was the most commonly found, appearing in 54.5 % of the children, followed by bacteria (29 %) and parasites (10.9 %). Other viral pathogens detected included adenovirus (6.4 %) and astrovirus (3.6 %). In rotavirus-positives cases, at least one other pathogen was detected, usually a bacterium (26.6 %). More than three episodes of watery diarrhea in 24 hours were observed in 78.3 % of the cases. Dehydration was found in 30 (50 %) rotavirus-positive children, of whom seven (11.6 %) were transferred to an intensive care unit due to complications of metabolic acidosis. Rotavirus was most commonly observed among children under 12 months old (65 %). The highest incidence of infection occurred in children who were under the care of a relative at home (78.3 %), had not been breastfed (65 %), or had been breastfed for less than six months (28.3 %). The genotype combinations most frequently found were G9P8 (28.3 %) and G1P8 (10 %). This study demonstrates the presence of rotavirus and other enteric pathogens as causes of gastroenteritis in hospitalized infants and young children in Cuba.

Unusual rotavirus genotypes among children with acute diarrhea in Saudi Arabia

Background

Human rotavirus A (human RV-A) is the most common cause of viral gastroenteritis in infants. The objective of the study was to characterize the G and P genotypes among clinical rotavirus isolates from children with acute diarrhea admitted to a tertiary care hospital in Riyadh, Saudi Arabia.

Methods

From 2011 to 2012, 541 pediatric patients with acute diarrhea were tested for rotavirus infection. RNA extractions from the fecal specimens were done by commercial kit. RT-PCR and sequencing techniques were used to detect the prevalent genotypes. Phylogenetic analysis by Maximum Likelihood method was used to study the clustering of the circulating genotypes.

Results

The data showed that 171/541 (31.6%) faecal samples were positive for human RVA and majority were children aged below 2 years. From the G and P [types] detected it was seen that (a) 171 minus 43 ie. 128 rotavirus positives were G typed successfully (b) 171 minus 20 ie. 151 rotavirus positives were P typed successfully; (c) overall G [P] nature was determined for 113 rotavirus positives out of 171. VP4 genotyping showed that majority of the positives 146/151 (96.7%) were P [8]; 4/151 (2.6%) were P [4]; 1/151 (0.66%) was P [6]. The dominant strains included G1P [8] 70/113 (61.9%); G9P [8] 19/113 (16.8%); G12P [8] 7/113 (6.2%) and G3P [8] 5/113 (4.4%) while the uncommon strains detected from Saudi Arabia during the study were G1P [4] 1/113 (0.88%) and G12P [6] 1/113 (0.88%). Phylogenetic tree, based on VP4/VP7 sequence analysis, revealed that G1P [8] was distinctly related to homologous strains included in human RV-A vaccine strains. Nevertheless, the uncommon genotypes G1P [4] and G12P [6] were clustered with isolates from other countries such as Bangladesh, China, Japan, Thailand and Philippines.

Conclusions

More studies will be required to further focus on newly emerging genotypes in our region together with the seasonality of rotavirus infection in the region, especially after January 2013 when the rotavirus vaccination has become part of routine childhood immunizations.

Efficacy of probiotic use in acute rotavirus diarrhea in children: A systematic review and meta-analysis

BACKGROUND

Probiotic therapies with different strains demonstrated some beneficial effects, although some studies did not show any significant effects. This study assessed systematically the current knowledge on the effect of probiotic bacteria on duration of acute rotavirus diarrhea in children compared with control.

METHODS

The PubMed, Cochrane Controlled Trial Register (CCTR) and Ovid (Wolters Kluwer Health) were searched between 1980 to June 15, 2013. Randomized controlled trials including the administration of probiotics for treatment of rotavirus diarrhea in infants and children were reviewed.

RESULTS

A total number of 1244 articles were found through the aforementioned search. 203 articles were selected after the first screening of title and abstract. The intervention group included subjects who received probiotic strains and dosage in any conditions. Placebo or any similar vehicle without probiotic was used in the controlled trials. Finally, 14 articles were selected. The outcomes from each study were considered in the duration of diarrhea. Statistical analyses were performed with Stata software. The pooled estimate of efficacy of probiotics in prevention or treatment of disease yielded in all studies a mean difference of 0.41 (CI 95%: -0.56 to -0.25; p<0.001). The pooled estimate of efficacy of lactobacillus rhamnosus GG and other probiotics significantly reduced the duration of diarrhea. Among trials, the overall reduction of LGG was 0.47 (CI 95%: -0.80 to -0.14; P= 0.020).

CONCLUSION

In conclusion, probiotics exert positive effect in reducing the duration of acute rotavirus diarrhea compared with control.

Flagellin in fusion with human rotavirus structural proteins exerts an adjuvant effect when delivered with replicating but non-disseminating adenovectors through the intrarectal route

Human rotavirus (HRV) is the worldwide leading cause of gastroenteritis in young children. Two live attenuated HRV vaccines have been approved since 2006. However, these live vaccines still have potential risks including reversion of virulence. Adenoviruses are suitable vectors for mucosal administration of subunit vaccines. In addition to the adjuvant effect of certain adenovirus components, the use of an adjuvant like flagellin is also another means to increase the immune response to the immunogen. The aim of this study was to determine whether flagellin in fusion with HRV structural proteins stimulates the innate immune response and enhances the HRV-specific immune response when delivered through the intrarectal route with replicating but non-disseminating adenovector (R-AdV). Salmonella typhimurium flagellin B (FljB) in fusion with HRV VP4Δ::VP7 protein induced IL-1β production in J774A.1 macrophages exposed to the R-AdV. Intrarectal administration of R-AdVs expressing either VP4Δ::VP7 or VP4Δ::VP7::FljB in BALB/c mice resulted in HRV-specific mixed Th1/Th2 immune responses. The HRV-specific antibody response elicited with the use of R-AdV expressing VP4Δ::VP7::FljB was higher than that with R-AdV expressing VP4Δ::VP7. The results also show that the replication capability of R-AdVs contributed to enhance the HRV-specific immune response as compared with that obtained with non-replicative AdVs. This work lays the foundation for using the R-AdV system and FljB-adjuvanted formulation to elicit a mucosal immune response specific to HRV.

Simultaneous detection of five enteric viruses associated with gastroenteritis by use of a PCR assay: a single real-time multiplex reaction and its clinical application

We developed a highly sensitive reverse transcription and multiplex real-time PCR (rtPCR) assay that can identify five viruses, including six genogroups, in a single reaction: norovirus genogroups I and II; sapovirus genogroups I, II, IV, and V; human rotavirus A; adenovirus serotypes 40 and 41; and human astrovirus. In comparison to monoplex rtPCR assays, the sensitivities and specificities of the multiplex rtPCR ranged from 75% to 100% and from 99% to 100%, respectively, evaluated on 812 clinical stool specimens.

Expression of human rotavirus chimeric fusion proteins from replicating but non disseminating adenovectors and elicitation of rotavirus-specific immune responses in mice

The aim of this study was to evaluate the usefulness of replicating but non disseminating adenovirus vectors (AdVs) as vaccine vector using human rotavirus (HRV) as a model pathogen. HRV VP7, VP4, or VP4Δ (N-terminal 336 amino acids of VP4) structural proteins as well as the VP4Δ::VP7 chimeric fusion protein were expressed in mammalian cells when delivered with the AdVs. A preliminary experiment demonstrated that VP4Δ was able to induce a HRV-specific IgG response in BALB/c mice inoculated intramuscularly with AdVs expressing the rotaviral protein. Moreover, an AdV-prime/plasmid DNA-boost regimen of vectors resulted in VP4Δ-specific antibody (Ab) titers ~4 times higher than those obtained from mice immunized with AdVs alone. Subsequently, the various HRV protein-encoding AdVs were compared using the AdV-prime/plasmid DNA-boost regimen. Higher IgG and IgA responses to HRV were obtained when VP4Δ::VP7 fusion protein was used as an immunogen as compared to VP7 or VP4 alone or to a mix of both proteins delivered independently by AdVs. A synergetic effect in terms of Ab was obtained with VP4Δ::VP7. In conclusion, this study demonstrated for the first time the suitability of using replicating but non disseminating AdVs as vaccine vector and the VP4Δ::VP7 fusion protein as an immunogen for vaccination against HRV.