Short Communication: Rotavirus Group A Occurrence in Rural Water Source Samples in a Midwest Region State of Brazil, Comparing Wet and Dry Seasons.

Identified as a potential reference pathogen by the WHO Guidelines for Drinking-Water Quality, Rotavirus (RV) is among the main enteric viruses that cause waterborne diseases. The aim of this study was to identify and correlate the presence of RV in collective and individual water sources of rural communities in the state of Goiás, within the seasons in which the collections were made (rainy and dry seasons). For this, 86 water samples in the dry period and 160 samples in the rainy period were collected. Concentration of water samples, extraction of viral genetic material and molecular tests were performed. When analyzing the presence of RV in the samples, taking into consideration the period studied, RV was found to be more prevalent in the dry season (54.7%) than in the rainy season (20%), showing a strong statistical association with the dry season (p-value < 0.001). The presence of pathogenic microorganisms in water is a public risk issue, enabling the emergence of outbreaks, endemics and epidemics. In the present research, there was an association between the presence of Rotavirus and the dry period of the year when compared to the rainy period.

Rotavirus-Specific Maternal Serum Antibodies and Vaccine Responses to RV3-BB Rotavirus Vaccine Administered in a Neonatal or Infant Schedule in Malawi.

High titres of rotavirus-specific maternal antibodies may contribute to lower rotavirus vaccine efficacy in low- and middle-income countries (LMICs). RV3-BB vaccine (G3P[6]) is based on a neonatal rotavirus strain that replicates well in the newborn gut in the presence of breast milk. This study investigated the association between maternal serum antibodies and vaccine response in infants administered the RV3-BB vaccine. Serum was collected antenatally from mothers of 561 infants enrolled in the RV3-BB Phase II study conducted in Blantyre, Malawi, and analysed for rotavirus-specific serum IgA and IgG antibodies using enzyme-linked immunosorbent assay. Infant vaccine take was defined as cumulative IgA seroconversion (≥3 fold increase) and/or stool vaccine shedding. Maternal IgA or IgG antibody titres did not have a negative impact on vaccine-like stool shedding at any timepoint. Maternal IgG (but not IgA) titres were associated with reduced take post dose 1 (p < 0.005) and 3 (p < 0.05) in the neonatal vaccine schedule group but not at study completion (week 18). In LMICs where high maternal antibodies are associated with low rotavirus vaccine efficacy, RV3-BB in a neonatal or infant vaccine schedule has the potential to provide protection against severe rotavirus disease.

Molecular Design of Encapsulin Protein Nanoparticles to Display Rotavirus Antigens for Enhancing Immunogenicity.

Rotavirus considerably threatens global health, particularly for children <5 years. Current, licensed oral attenuated vaccine formulations have limitations including insufficient efficacy in children in low- and middle-income countries, warranting urgent development of novel vaccines with improved efficacy and safety profiles. Herein, we present a novel approach utilizing an encapsulin (ENC) nanoparticle (NP)-based non-replicating rotavirus vaccine. ENC, originating from bacteria, offers a self-assembling scaffold that displays rotavirus VP8* antigens on its surface. To enhance the correct folding and soluble expression of monomeric antigens and their subsequent assembly into NP, we adopted an RNA-interacting domain (RID) of mammalian transfer RNA synthetase as an expression tag fused to the N-terminus of the ENC-VP8* fusion protein. Using the RID-ENC-VP8* tripartite modular design, insertion of linkers of appropriate length and sequence and the universal T cell epitope P2 remarkably improved the production yield and immunogenicity. Cleavage of the RID rendered a homogenous assembly of ENC-P2-VP8* into protein NPs. Immunization with ENC-P2-VP8* induced markedly higher levels of VP8*-specific antibodies and virus neutralization titers in mice than those induced by P2-VP8* without ENC. Altogether, these results highlight the potential of the designed ENC NP-based rotavirus vaccine as an effective strategy against rotavirus disease to address global health challenges.

Effects of Rotavirus NSP4 on the Immune Response and Protection of Rotavirus-Norovirus Recombinant Subunit Vaccines in Different Immune Pathways.

Diarrheal disease continues to be a major cause of global morbidity and mortality among children under 5 years of age. To address the current issues associated with oral attenuated rotavirus vaccines, the study of parenteral rotavirus vaccines has promising prospects. In our previous study, we reported that rotavirus nonstructural protein 4 (NSP4) did not increase the IgG antibody titer of co-immune antigen but did have a protective effect against diarrhea via the intramuscular injection method. Here, we explored whether NSP4 can exert adjuvant effects on mucosal immune pathways. In this study, we immunized mice via muscle and nasal routes, gavaged them with the rotavirus Wa strain or the rotavirus SA11 strain, and then tested the protective effects of immune sera against both viruses. The results revealed that the serum-specific VP8* IgG antibody titers of the mice immunized via the nasal route were much lower than those of the mice immunized by intramuscular injection, and the specific IgA antibodies were almost undetectable in the bronchoalveolar lavage fluid (BALF). NSP4 did not increase the titer of specific VP8* antibodies in either immune pathway. Therefore, in the two vaccines (PP-NSP4-VP8* and PP-VP8*+NSP4) used in this study, NSP4 was unable to perform its potential adjuvant role through the mucosal immune pathway. Instead, NSP4 was used as a co-immunized antigen to stimulate the mice to produce specific binding antibodies that play a protective role against diarrhea.

Passive Immunotherapy of Cynomolgus Monkeys with Anti-Rotavirus IgY.

Immunoglobulins Y (IgY) purified from egg yolks of hens represents an attractive, cost-effective alternative for the development of new diagnostic and therapeutic platforms. In this study, we evaluated the therapeutic efficacy of rotavirus-specific IgY in a cynomolgus monkey (Macaca fascicularis) model. Animals were experimentally infected with human rotavirus Group A (RVA), the most common cause of severe acute diarrhoea among young children worldwide. Animals were administered human RVA (3.1 × 107 FFU/mL) by oral gavage, challenged with 2.5 mg of anti-RVA IgY orally, and monitored for five days according to clinical, haematological and biochemical parameters; serum electrolyte levels; viral shedding; and histopathological changes. Immunotherapy with anti-RVA IgY had a protective effect against severe rotavirus-induced enteritis in four of the ten treated monkeys, as evidenced by histopathological findings. Although only one animal had diarrhoea, all but one exhibited virus shedding regardless of the treatment.

Isolation, Genomic Characterization and Evolution of Six Porcine Rotavirus A Strains in a Pig Farming Group.

Porcine rotavirus (PoRV) is a significant enteric pathogen causing gastroenteritis in piglets, which causes huge economic loss to the Chinese pig industry. In this study, six porcine rotavirus A strains were isolated from three adjacent sow farms belonging to the same company within one year, which suffered severe diarrhea outbreaks. AHBZ2303 (G11P[7]) and AHBZ2305 (G9P[23]), AHBZ2304 (G9P[23]) and AHBZ2312 (G4P[6]), AHBZ2310 (G9P[23]) and AHBZ2402 (G5P[23]) were isolated from Farm A, B and C, respectively. All six isolates were related to human rotavirus through complete genome analysis, suggesting the potential cross-species infection between humans and pigs. Evolutionary analysis revealed that AHBZ2303 and AHBZ2304 likely emerged simultaneously in Farm A and B, and then AHBZ2304 was introduced to Farm A and C, leading to the emergence of AHBZ2305 and AHBZ2310. Recombination and large variation were identified for AHBZ2312 and AHBZ2402. These findings provided insights into the transmission and evolution of PoRV among farms and underscored the need for enhanced monitoring to mitigate the risk of outbreaks from novel variants.

Full genome sequence analysis of the predominant and uncommon G9P[4] rotavirus strains circulating in Tehran, Iran, 2021-2022: Evidence for inter and intra-genotype recombination.

Group A rotaviruses (RVAs) are a major cause of acute gastroenteritis in children under 5 years of age worldwide. Herein, the genetic sequences of 11 RNA segments from three uncommon G9P[4] RVA strains found in the stool samples of children under 5 years of age in Iran were analyzed using next-generation sequencing (NGS) technology. The genomic constellations of these three uncommon G9P[4] strains indicated the presence of the double and quadruple reassortants of two G9P[4] strains, containing the VP7/NSP2 and VP7/VP2/NSP2/NSP4 genes on a DS-1-like genetic background, respectively. The genome of one strain indicated a Wa-like genetic backbone in a single-reassortant with the VP4 of the DS1-like human strains. With the exception of VP1, VP2, VP7, NSP2, NSP3, and NSP4 genes, which clustered with RVA of human origins belonging to cognate gene sequences of genogroup 1/2 genotypes/lineages, the remaining five genes (VP8/VP4, VP3, VP6, NSP1, NSP5) displayed direct evidence of recombination. It is presumed that the presence of uncommon G9P[4] strains in Iran is not linked to vaccination pressure, but rather to the high prevalence of RVA co-infection or the direct import of these uncommon RVA reassortants strains from other countries (especially those that have implemented RV vaccination).

The Frequency of Rotavirus Gastroenteritis in Children from West of Iran and Genotyping of Rotavirus Isolates: A Suggestion for Further Changes in Childhood Immunization Program.

BACKGROUND: Rotavirus is the most common cause of gastroenteritis among children. Currently, four oral live-attenuated vaccines are available to prevent rotavirus infection. The World Health Organization (WHO) has recommended including rotavirus vaccination in national immunization programs; however, it has not been introduced to the Iranian national immunization program. The study aimed to assess the frequency of rotavirus gastroenteritis in the west of Iran and investigate the necessity of rotavirus vaccination. Study Design: A case series study. METHODS: In this case series study, 284 cases under six years of age who presented with acute gastroenteritis from March 2021 to 2022 to a referral hospital in the west of Iran were evaluated. Data on baseline characteristics, clinical manifestations, results of stool test, ELISA for rotavirus detection, and polymerase chain reaction (PCR) test for genotyping of rotavirus-positive samples were recorded. RESULTS: Results showed that the prevalence of rotavirus infection was 36.6%. The highest frequency was observed among children aged 6-12 months and during the autumn. According to the PCR results, G1P[8], G9P[8], G9P[4], and G1P [4] were the dominant genotypes, and 33.75% of samples were infected with multiple rotavirus genotypes. CONCLUSION: The study highlights the considerable prevalence of rotavirus infection among cases of acute gastroenteritis in children under six years of age who were referred to a referral hospital in the west of Iran and the high diversity of rotavirus genotypes in the targeted community. Consequently, physicians and health policymakers should prioritize strategies for the prevention and control of this infection, particularly by considering the rotavirus vaccine as a priority for the Iranian national immunization program.

Systematic literature review and meta-analysis on the prevalence of rotavirus genotypes in Europe and the Middle East in the post-licensure period.

Previous systematic literature reviews of rotavirus genotype circulation in Europe and the Middle East are limited because they do not include country-specific prevalence data. This study documents country-specific evidence on the prevalence of rotavirus genotypes in Europe and the Middle East to enable more precise epidemiological modeling and contribute to the evidence-base about circulating rotavirus genotypes in the post-vaccination era. This study systematically searched PubMed, Embase and Scopus for all empirical epidemiological studies that presented genotype-specific surveillance data for countries in Europe and the Middle East published between 2006 and 2021. The STROBE checklist was used to assess the quality of included studies. Proportional meta-analysis was conducted using the generic inverse variance method with arcsine transformation and generalized linear-mixed models to summarize genotype prevalence. Our analysis estimated the genotype prevalence by country across three date categories corresponding with rotavirus seasons: 2006-2010, 2011-2015, 2016-2021. A total of 7601 deduplicated papers were identified of which 88 studies were included in the final review. Rotavirus genotypes exhibited significant variability across regions and time periods, with G1P[8], G2P[4], G3P[8], G4P[8], G9P[8], and, to a lesser extent G12P[8], being the most prevalent genotypes through different regions and time-periods. Uncommon genotypes included G3P[9] in Poland, G2P[6] in Iraq, G4P[4] in Qatar, and G9P[4] as reported by the European Rotavirus Network. There was high genotype diversity with routinely identified genotypes being G1P[8], G2P[4], G3P[8], G4P[8], and G9P[8]; there was high variability across time periods and regions. Continued surveillance at the national and regional levels is relevant to support further research and inform public health decision-making.

This study synthesizes data from rotavirus surveillance studies to characterize genotype-specific prevalence of rotavirus in Europe and the Middle East following the licensure of rotavirus vaccines in 2006. In line with previous pan-European studies, results highlight the lack of a single dominant genotype across this time period. There was high genotype diversity with G1P[8], G2P[4], G3P[8], G4P[8], and G9P[8] being the most commonly identified genotypes through different regions and time-periods.

Safety of Rotavirus Vaccination in Infants That Were Exposed to Biologics In Utero: A Systematic Review.

BACKGROUND: In infants that were exposed to biologics in utero, gastroenterology societal guidelines have either recommended against administration of the live rotavirus vaccine until 6-12 months of age or until serum biologic levels are undetectable. We performed a systematic review to evaluate the safety of rotavirus vaccination in biologic-exposed infants. METHODS: EMBASE, PubMed, Scopus, and Cochrane databases were searched from 2006 to 2024 for original data reporting on the safety of rotavirus vaccination in infants that were exposed to anti-tumor necrosis factors (TNFs) (ie, infliximab, adalimumab, golimumab, certolizumab) and non-TNF biologics (ie, vedolizumab, ustekinumab, rizankizumab, mirikizumab) in utero. RESULTS: A database search yielded 7185 screening results of which 10 studies met inclusion criteria. There were over 300 instances of rotavirus vaccination in biologic-exposed infants (n = 162 exposed to anti-TNFs, n = 142 exposed to non-TNF biologics). Biologic-exposed infants were not at an increased risk of severe adverse events or adverse events of any severity related to rotavirus vaccination. CONCLUSIONS: Administration of the live rotavirus vaccine appears to be safe in biologic-exposed infants. As such, with careful examination of the risks and benefits, there may be a role for rotavirus vaccination in this population.

We performed a systematic review evaluating the safety of rotavirus vaccination in infants that were exposed to anti-TNFs and non-TNF biologics in utero. There was no increased risk of adverse events associated with rotavirus vaccination in this population.

Effect of HDAC9-induced deacetylation of glycolysis-related GAPDH lysine 219 on rotavirus replication in rotavirus-infected Caco-2 cells.

Post-translational modifications (PTMs), as epigenetic modifications, are significant in the interaction between virus and its host. However, it is unclear whether rotavirus (RV) causes changes in both the host cell epigenetic protein modification and the regulatory mechanism of viral replication. Here, we analyzed the proteome of Caco-2 cells to determine if acetylation modification occurred within the cells after RV infection. We found that glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a protein involved in glycolysis, was deacetylated at lysine 219 via histone deacetylase 9 (HDAC9) in 50 h after the RV infection. Remarkably, the deacetylation of GAPDH promoted RV replication. Finally, we found that glycolysis was alterable in Caco-2 cells by RV or the deacetylation of GAPDH lysine 219, using the Seahorse XF Glycolysis Stress Test. In conclusion, our results demonstrate for the first time that RV infection promoted deacetylation of GAPDH at lysine 219 in order to increase its own viral replication in Caco-2 cells.

Health impact of rotavirus vaccination in China.

Rotavirus (RV) vaccines have demonstrated substantial effectiveness in reducing the healthcare burden caused by gastroenteritis (RVGE) worldwide. This study aims to understand the differential impact of RV vaccination in reducing RVGE burden in children under 7 years old in China. A Markov Model was used to investigate the health impact of introducing two different RV vaccines into the Chinese population. The analysis was conducted for RV5, a live pentavalent human-bovine reassortant vaccine, and Lanzhou Lamb RV (LLR), a live-attenuated monovalent RV vaccine, separately, by comparing the strategy of each vaccine to no vaccination within a Chinese birth cohort, including 100,000 children modeled until 7 years of age. The vaccination scenario assumed a vaccination coverage of 2.5%, 2.5%, 90% and 5% for doses one, two, three and no vaccine, respectively, for both vaccines. Strategies with RV5, LLR, and no vaccination were associated with 9,895, 49,069, and 64,746 symptomatic RV infections, respectively. RV5 and LLR were associated with an 85% and 24% reduction in the total symptomatic RV infections, respectively, suggesting that the health benefits of RV5 are at least three-fold greater than those associated with the LLR. Further, strategies with RV5 and LLR resulted in an estimated 206 and 59-year increase in quality-adjusted life years (QALYs), respectively. Sensitivity and scenario analyses supported the robustness of the base-case findings. Use of RV vaccine is expected to improve RV-associated health outcomes and its adoption will help alleviate the burden of RVGE in China. RV5 use will result in significantly better health outcomes.

Effectiveness of Lanzhou Lamb Rotavirus Vaccine and RotaTeq Against Hospitalized Rotavirus Infections Among Children During 2020-2023 in Guangdong Province, China: A Test-Negative Case-Control Study.

INTRODUCTION: The evidence regarding the effectiveness of Lanzhou Lamb Rotavirus Vaccine (LLR) and RotaTeq (RV5) against gastroenteritis (RVGE) caused by emerging genotypes in Chinese children remains limited. METHODS: We conducted a test-negative case-control study using gastroenteritis surveillance data from four cities (2020-2023) in Guangdong Province, China. Children aged 2 months to 5 years hospitalized with acute gastroenteritis were enrolled. Cases were rotavirus-positive; controls were rotavirus-negative. Vaccine effectiveness (VE) was estimated using multivariable logistic regressions. RESULTS: Among 2650 children, 218 (8.2%) were rotavirus-positive, predominantly G8P[8]. Also, 1543 (58.23%) children were unvaccinated, while 632 (23.85%) and 475 (17.92%) received at least one dose of RV5 and LLR, respectively. Adjusted RV5 VE against any RVGE severity was 51.7% [95% confidence interval (CI) - 58.1-85.3%]) for one dose, 37.6% (95% CI - 58.5-75.4%) for two doses, and 64.1% (95% CI 38.0-79.2%) for three doses. For LLR, VE against any RVGE severity was 38.7% (95% CI 5.7-60.2%) for one dose, 74.6% (95% CI 35.3-90.0%) for two doses, and 58.8% (95% CI - 217.6-94.6%) for three doses. Against severe RVGE, RV5 VE was 67.2% (95% CI - 144.7-95.6%) for one dose, 74.0% (95% CI - 92.1-96.5%) for two doses, and 86.6% (95% CI 56.8-95.9%) for three doses. For LLR, VE against severe RVGE was 57.7% (95% CI 20.3-77.6%) for one dose, 73.4% (95% CI 11.9-92.0%) for two doses, and - 27.8% (95% CI - 949.7-84.4%) for three doses. CONCLUSIONS: Both RV5 and LLR provided protection against RVGE, including the emerging G8P[8] genotype. Three doses of RV5 offered strong protection, while two doses of LLR also appeared to be an effective strategy against rotavirus infection.

Rotavirus is a common cause of severe diarrhea in young children, and vaccines are crucial in preventing this illness. This study looked at how well two rotavirus vaccines, Lanzhou Lamb Rotavirus Vaccine (LLR) and RotaTeq (RV5), protect children against rotavirus gastroenteritis (RVGE), including infections caused by a new strain called G8P[8]. We analyzed data from children aged 2 months to 5 years who were hospitalized between 2020 and 2023. We compared children who tested positive for rotavirus (cases) with those who tested negative (controls) to determine how well the vaccines worked. Our results showed that both RV5 and LLR vaccines provided protection against RVGE. For RV5, three doses provided strong protection, while for LLR, two doses provided good protection. Against severe RVGE, three doses of RV5 were effective, while two doses of LLR also showed good protection.

Monovalent rotavirus vaccine effectiveness and long-term impact among children <5 years old in Antananarivo, Madagascar, 2010-2022.

BACKGROUND: Monovalent rotavirus vaccine substantially reduced rotavirus disease burden after introduction (May 2014) in Madagascar. We examined the effectiveness and long-term impact on acute watery diarrhea and rotavirus-related hospitalizations among children <5 years old at two hospitals in Antananarivo, Madagascar (2010-2022). METHODS: We used a test-negative case-control design to estimate monovalent rotavirus vaccine effectiveness (VE) against laboratory-confirmed rotavirus hospitalizations among children age 6-23 months with documented vaccination status adjusted for year of symptom onset, rotavirus season, age group, nutritional status, and clinical severity. To evaluate the impact, we expanded to children age 0-59 months with acute watery diarrhea. First, we used admission logbook data to compare the proportion of all hospitalizations attributed to diarrhea in the pre-vaccine (January 2010-December 2013), transition period (January 2014-December 2014), and post-vaccine (January 2015-December 2022) periods. Second, we used active surveillance data (June 2013-May 2022) to describe rotavirus positivity and detected genotypes by vaccine introduction period and surveillance year (1 June-31 May). RESULT: Adjusted VE of at least one dose against hospitalization due to rotavirus diarrhea among children age 6-23 months was 61 % (95 % CI: -39 %-89 %). The annual median proportion of hospitalizations attributed to diarrhea declined from 28 % in the pre-vaccine to 10 % in the post-vaccine period. Rotavirus positivity among hospitalized children age 0-59 months with acute watery diarrhea was substantially higher during the pre-vaccine (59 %) than the post-vaccine (23 %) period. In the pre-vaccine period, G3P[8] (76 %) and G2P[4] (12 %) were the dominant genotypes detected. Although genotypes varied by surveillance year, G1P[8] and G2P[4] represented >50 % of the genotypes detected post-introduction. CONCLUSIONS: Rotavirus vaccine has been successfully implemented in Madagascar's routine childhood immunization program and had a large impact on rotavirus disease burden, supporting continued use of rotavirus vaccines in Madagascar.

Virus-like Particles vaccine based on co-expression of G5 Porcine rotavirus VP2-VP6-VP7 induces a powerful immune protective response in mice.

Porcine rotavirus (PoRV), a member of the Reoviridae family, constitutes a principal etiological agent of acute diarrhea in piglets younger than eight weeks of age, and it is associated with considerable morbidity and mortality within the swine industry. The G5 genotype rotavirus strain currently predominates in circulation. To develop a safe and effective porcine rotavirus vaccine, we generated an insect cell-baculovirus expression system, and successfully expressed these three viral proteins and assembled them into virus-like particles (VLPs) co-displaying VP2, VP6, and VP7. Transmission electron microscopy (TEM) analysis revealed that the VP2-VP6-VP7 VLPs exhibited a "wheeled" morphology resembling that of native rotavirus particles, with an estimated diameter of approximately 65 nm. To evaluate the immunogenicity and protective efficacy of these VP2-VP6-VP7 VLPs, we immunized BALB/C mice with four escalating doses of the VLPs, ranging from 5 to 40 µg of VLP protein per dose. ELISA-based assessments of PoRV-specific antibodies and T cell cytokines, including IL-4, IL-2, and IFN-γ, demonstrate that immunization with VP2-VP6-VP7 VLPs can effectively elicit both humoral and cellular immune responses in mice, resulting in a notable induction of neutralizing antibodies. On days 4, 6, 8, and 10 post-infection (dpi), the VLP-vaccinated group exhibited significantly reduced levels of PoRV RNA copy numbers when compared to the PBS controls. Histological examination of the duodenum, ileum, and kidneys revealed that VP2-VP6-VP7 VLPs provided effective protection against PoRV induced intestinal injury. Collectively, these findings indicate that the VLPs generated in this study possess strong immunogenicity and suggest the considerable promise of the VLP-based vaccine candidate in the prevention and containment of Porcine Rotavirus infections.

Shigella and ETEC have replaced rotavirus as main causes of childhood diarrhea in Rwanda after ten years of rotavirus vaccination.

The causes of diarrhea after ten years of rotavirus vaccination in Rwanda were investigated in 496 children with and 298 without diarrhea using a real-time PCR. Rotavirus was detected in 11% of children with diarrhea (OR 2.48, P=0.002). Comparison of population attributable fractions (PAF) show that Shigella (PAF=11%) and ETEC-eltB (PAF=12%) have replaced rotavirus as the main causative agents. The PAF for rotavirus had declined from 41% pre-vaccination to 6.5%, indicating that rotavirus has become one among several similarly important causes of childhood diarrhea in Rwanda. A rotavirus genotype shift to G3P[8] points at the importance of continued genotype surveillance.

Factors associated with antibiotic use in children hospitalized for acute viral gastroenteritis and the relation to rotavirus vaccination.

Evidence on unnecessary antibiotic use in children with acute viral gastroenteritis (AGE) is scarce. We characterized the extent and correlates of antibiotic use among children hospitalized with viral AGE. A single-center study enrolled children aged 0-59 months hospitalized for AGE between 2008 and 2015 in Israel. Information was collected on laboratory tests, diagnoses, antibiotic treatment, and rotavirus vaccination. Stool samples were tested for rotavirus antigen, GII-norovirus, and stool cultures were performed for bacterial enteropathogens. Data from 2240 children were analyzed. Rotavirus vaccine was given to 79% of eligible children. Rotavirus test was performed on 1419 (63.3%) children. Before the introduction of universal rotavirus vaccination (2008-2010), rotavirus positivity in stool samples was 37.0%, which declined to 17.3% during the universal vaccination years (2011-2015). Overall, 1395 participants had viral AGE. Of those, 253 (18.1% [95% CI 16.1-20.2]) had unnecessary antibiotic treatment, mostly penicillin 46.6%, ceftriaxone 34.0% and azithromycin 21.7%. A multivariable analysis showed an inverse association between rotavirus vaccination and unnecessary antibiotic treatment (odds ratio = 0.53 [95% CI 0.31-0.91]), while positive associations were found with performing chest-X-ray test (3.00 [1.73-5.23]), blood (3.29 [95% CI 1.85-5.86]) and urine cultures (7.12 [3.77-13.43]), levels of C-reactive protein (1.02 [1.01-1.02]) and leukocytes (1.05 [1.01-1.09]). The results were consistent in an analysis of children with laboratory-confirmed rotavirus or norovirus AGE, or after excluding children with CRP > 50 mg/L. In conclusion, antibiotic prescription was common among hospitalized children with viral AGE, which was inversely related to rotavirus vaccination, possibly due to less severe illness in the vaccinated children.

Detection and molecular characterization of major enteric pathogens in calves in central Ethiopia.

BACKGROUND: Calf diarrhea is a major cause of morbidity and mortality in the livestock sector worldwide and it can be caused by multiple infectious agents. In Ethiopia, cattle are the most economically important species within the livestock sector, but at the same time the young animals suffer from high rates of morbidity and mortality due to calf diarrhea. However, studies including both screening and molecular characterization of bovine enteric pathogens are lacking. Therefore, we aimed to both detect and molecularly characterize four of the major enteric pathogens in calf diarrhea, Enterotoxigenic Escherichia coli (E. coli K99 +), Cryptosporidium spp., rotavirus A (RVA), and bovine coronavirus (BCoV) in calves from central Ethiopia. Diarrheic and non-diarrheic calves were included in the study and fecal samples were analyzed with antigen-ELISA and quantitative real-time PCR (qPCR). Positive samples were further characterized by genotyping PCRs. RESULTS: All four pathogens were detected in both diarrheic and non-diarrheic calves using qPCR and further characterization showed the presence of three Cryptosporidium species, C. andersoni, C. bovis and C. ryanae. Furthermore, genotyping of RVA-positive samples found a common bovine genotype G10P[11], as well as a more unusual G-type, G24. To our knowledge this is the first detection of the G24 RVA genotype in Ethiopia as well as in Africa. Lastly, investigation of the spike gene revealed two distinct BCoV strains, one classical BCoV strain and one bovine-like CoV strain. CONCLUSIONS: Our results show that Cryptosporidium spp., E. coli K99 + , RVA and BCoV circulate in calves from central Ethiopia. Furthermore, our findings of the rare RVA G-type G24 and a bovine-like CoV demonstrates the importance of genetic characterization.

Unravelling aggregation propensity of rotavirus A VP6 expressed as E. coli inclusion bodies through in silico prediction.

The inner capsid protein of rotavirus, VP6, emerges as a promising candidate for next-generation vaccines against rotaviruses owing to its abundance in virion particles and high conservation. However, the formation of inclusion bodies during prokaryotic VP6 expression poses a significant hurdle to rotavirus research and applications. Here, we employed experimental and computational approaches to investigate inclusion body formation and aggregation-prone regions (APRs). Heterologous recombinant VP6 expression in Escherichia coli BL21(DE3) cells resulted in inclusion body formation, confirmed by transmission electron microscopy revealing amorphous aggregates. Thioflavin T assay demonstrated incubation temperature-dependent aggregation of VP6 inclusion bodies. Computational predictions of APRs in rotavirus A VP6 protein were performed using sequence-based tools (TANGO, AGGRESCAN, Zyggregator, Waltz, FoldAmyloid, ANuPP, Camsol intrinsic) and structure-based tools (SolubiS, CamSol structurally corrected, Aggrescan3D). A total of 24 consensus APRs were identified, with 21 of them being surface-exposed in VP6. All identified APRs display a predominance of hydrophobic amino acids, ranging from 33 to 100%. Computational identification of these APRs corroborates our experimental observation of VP6 inclusion body or aggregate formation. Characterization of VP6's aggregation propensity facilitates understanding of its behaviour during prokaryotic expression and opens avenues for protein engineering of soluble variants, advancing research on rotavirus VP6 in pathology, therapy, and diagnostics.

Towards the Development of a Minigenome Assay for Species A Rotaviruses.

RNA virus polymerases carry out multiple functions necessary for successful genome replication and transcription. A key tool for molecular studies of viral RNA-dependent RNA polymerases (RdRps) is a 'minigenome' or 'minireplicon' assay, in which viral RdRps are reconstituted in cells in the absence of full virus infection. Typically, plasmids expressing the viral polymerase protein(s) and other co-factors are co-transfected, along with a plasmid expressing an RNA encoding a fluorescent or luminescent reporter gene flanked by viral untranslated regions containing cis-acting elements required for viral RdRp recognition. This reconstitutes the viral transcription/replication machinery and allows the viral RdRp activity to be measured as a correlate of the reporter protein signal. Here, we report on the development of a 'first-generation' plasmid-based minigenome assay for species A rotavirus using a firefly luciferase reporter gene.