Human Astrovirus Research Articles

Deletion of the s2m RNA Structure in the Avian Coronavirus Infectious Bronchitis Virus and Human Astrovirus Results in Sequence Insertions.

Coronaviruses infect a wide variety of host species, resulting in a range of diseases in both humans and animals. The coronavirus genome consists of a large positive-sense single-stranded molecule of RNA containing many RNA structures. One structure, denoted s2m and consisting of 41 nucleotides, is located within the 3' untranslated region (3' UTR) and is shared between some coronavirus species, including infectious bronchitis virus (IBV), severe acute respiratory syndrome coronavirus (SARS-CoV), and SARS-CoV-2, as well as other pathogens, including human astrovirus. Using a reverse genetic system to generate recombinant viruses, we investigated the requirement of the s2m structure in the replication of IBV, a globally distributed economically important Gammacoronavirus that infects poultry causing respiratory disease. Deletion of three nucleotides predicted to destabilize the canonical structure of the s2m or the deletion of the nucleotides corresponding to s2m impacted viral replication in vitro. In vitro passaging of the recombinant IBV with the s2m sequence deleted resulted in a 36-nucleotide insertion in place of the deletion, which was identified to be composed of a duplication of flanking sequences. A similar result was observed following serial passage of human astrovirus with a deleted s2m sequence. RNA modeling indicated that deletion of the nucleotides corresponding to the s2m impacted other RNA structures present in the IBV 3' UTR. Our results indicated for both IBV and human astrovirus a preference for nucleotide occupation in the genome location corresponding to the s2m, which is independent of the specific s2m sequence. IMPORTANCE Coronaviruses infect many species, including humans and animals, with substantial effects on livestock, particularly with respect to poultry. The coronavirus RNA genome consists of structural elements involved in viral replication whose roles are poorly understood. We investigated the requirement of the RNA structural element s2m in the replication of the Gammacoronavirus infectious bronchitis virus, an economically important viral pathogen of poultry. Using reverse genetics to generate recombinant IBVs with either a disrupted or deleted s2m, we showed that the s2m is not required for viral replication in cell culture; however, replication is decreased in tracheal tissue, suggesting a role for the s2m in the natural host. Passaging of these viruses as well as human astrovirus lacking the s2m sequence demonstrated a preference for nucleotide occupation, independent of the s2m sequence. RNA modeling suggested deletion of the s2m may negatively impact other essential RNA structures.

Discovery of novel Mamastroviruses in Bactrian camels and dromedaries reveals complex recombination history.

Virus emergence may occur through interspecies transmission and recombination of viruses coinfecting a host, with potential to pair novel and adaptive gene combinations. Camels are known to harbor diverse ribonucleic acid viruses with zoonotic and epizootic potential. Among them, astroviruses are of particular interest due to their cross-species transmission potential and endemicity in diverse host species, including humans. We conducted a molecular epidemiological survey of astroviruses in dromedaries from Saudi Arabia and Bactrian camels from Inner Mongolia, China. Herein, we deployed a hybrid sequencing approach coupling deep sequencing with rapid amplification of complementary deoxyribonucleic acid ends to characterize two novel Bactrian and eight dromedary camel astroviruses, including both partial and complete genomes. Our reported sequences expand the known diversity of dromedary camel astroviruses, highlighting potential recombination events among the astroviruses of camelids and other host species. In Bactrian camels, we detected partially conserved gene regions bearing resemblance to human astrovirus types 1, 4, and 8 although we were unable to recover complete reading frames from these samples. Continued surveillance of astroviruses in camelids, particularly Bactrian species and associated livestock, is highly recommended to identify patterns of cross-species transmission and to determine any epizootic threats and zoonotic risks posed to humans. Phylogenomic approaches are needed to investigate complex patterns of recombination among the astroviruses and to infer their evolutionary history across diverse host species.

Diversity of human astroviruses in Germany 2018 and 2019

Aim of this study was to investigate the molecular diversity of human astroviruses (HAstV) in Germany. A follow-up study was performed with human stool samples collected in 2018–2019, which were genotyped retrospectively. A total of 2645 stool samples, collected between January 2018 and December 2019 from sporadic cases and outbreaks of acute gastroenteritis were analyzed. An algorithm of PCR systems was used to characterize human astrovirus. Human astroviruses were found in 40 samples (positive rate: 1.6%). During the study period, children aged 1–2 years (48%) were most affected by HAstV. Genotyping revealed a number of nine circulating genotypes representing four human Mamastrovirus species. Strain MLB1 was predominant in the study population with a detection rate of 25% followed by HAstV1 with a positive rate of 20%. The diversity of astrovirus genotypes seems to be rather stable in Germany in the last years. A clustering of regionally and/or temporally linked human astroviruses in Germany was not detectable.

Detection of Six Different Human Enteric Viruses Contaminating Environmental Water in Chiang Mai, Thailand.

A 2-year surveillance study into enteric viruses contaminating environmental water samples was conducted in the city of Chang Mai, Thailand. The aim of the study was to investigate the prevalence of six different human enteric viruses, specifically, adenovirus (AdV), astrovirus (AstV), enteroviruses (EVs), human parechovirus (HPeV), rotavirus (RV), and saffold virus (SAFV), contaminating several types of environmental water using PCR and reverse transcription-PCR (RT-PCR) methods. All targeted viruses were detected with different levels of prevalence. The levels ranged from 0.8 to 4.8% (AdV, 0.8%; AstV, 4.8%; EV, 0.8%; HPeV, 3.2%; RV, 0.8%; SAFV, 3.2%). A wide variety of human enteric virus genotypes, including AdV-41, AstV-MLB1, coxsackievirus A, HPeV1, 5, and 6, RV G4[P8], and SAFV-2 and 3 were detected. The overall picture of the 13 human enteric viruses that were detected in environmental water in Chiang Mai, Thailand, is also summarized in this study. The data and the findings of this study will provide a better understanding of the viral dynamics in environmental water. The detection of these viruses in environmental water indicates there is the potential for human infection from this source. IMPORTANCE Human enteric viruses are a major cause of gastrointestinal illness, and these viruses can be introduced into environmental water through various routes. Viral contamination in water could play a significant role in human health. This study demonstrated the prevalence of six different enteric viruses, adenovirus, astrovirus, enteroviruses, human parechovirus, rotavirus, and saffold virus, contaminating environmental water. We also analyzed the overall prevalence of other enteric viruses that were in this area, and the findings revealed a wide diversity of the enteric viruses contaminating environmental water. The data provide a better understanding of the epidemiologic importance of viral contamination of the water and highlight the need for better management of wastewater disposal and effective environmental water treatment to prevent the human population from infection.

Comparison of the risk of infection of human rotavirus and astrovirus according to fishing and swimming activities at Las Cañas beach, Uruguay.

To estimate the risk of human rotavirus (RV) and astrovirus (HAstV) infections for swimmers and fishers at Las Cañas beach, Uruguay. Surface water samples were collected monthly for 1 year. The dose-response models used were β-Poisson and 1 F1 hypergeometric for RV and HAstV, respectively. The probabilities of infection were calculated using a kernel density estimate to fitting the data and then sampling from this distribution (Monte Carlo simulation). The probability of RV infection for fishers was between 0 and 65% and for swimmers was between 0 and 50% (<18 years old) and between 0 and 38% (>18 years old). For HAstV, the probability of infection for fishers was between 0% and 45% and for swimmers was between 0 and 38% (<18 years old) and between 0 and 18% (>18 years old). This study suggests that fishers are at higher risk of infection for both viruses compared with swimmers mainly due to higher viral frequency and concentration at the site for fishing activities.

Structure of the divergent human astrovirus MLB capsid spike

Despite their worldwide prevalence and association with human disease, the molecular bases of human astrovirus (HAstV) infection and evolution remain poorly characterized. Here, we report the structure of the capsid protein spike of the divergent HAstV MLB clade (HAstV MLB). While the structure shares a similar folding topology with that of classical-clade HAstV spikes, it is otherwise strikingly different. We find no evidence of a conserved receptor-binding site between the MLB and classical HAstV spikes, suggesting that MLB and classical HAstVs utilize different receptors for host-cell attachment. We provide evidence for this hypothesis using a novel HAstV infection competition assay. Comparisons of the HAstV MLB spike structure with structures predicted from its sequence reveal poor matches, but template-based predictions were surprisingly accurate relative to machine-learning-based predictions. Our data provide a foundation for understanding the mechanisms of infection by diverse HAstVs and can support structure determination in similarly unstudied systems.

An annoying enteric virus: A systematic review and meta-analysis of human astroviruses and gastrointestinal complications in children.

Human astroviruses (HAstVs) have frequently been detected in individuals with acute gastroenteritis (AGE). However, a precise estimate of the overall prevalence of the virus in children with AGE as well as the possible association of the virus with gastrointestinal complications is not available up to now. The present study estimated the overall prevalence of HAstVs in children with gastrointestinal complications as well as the association between the virus and symptoms. We systematically searched four international databases (PubMed, Scopus, Web of Science, and Google scholar) to find studies on the prevalence of HAstVs in people with AGE published between Jan 2000 and Sep 2021. Analysis of the 223 included studies presented a 4.2% (95% CI 3.8%-4.8%) prevalence of the virus in AGE individuals. Based on case-control studies, a significant association between these viruses and AGE was detected (OR: 2.059, 95% CI; 1.438-2.949). HAstV-1 and HAstV-VA-2 is the most and least common genotypes in the AGE patients, respectively (59.0%, 95% CI: 52.1%-65.6% vs. 4.9%, 95% CI: 2.6%-9.1%). Due to the statistically significant association between HAstV and gastrointestinal complications, more attention should be paid to these viruses in people with AGE and more studies should employ case-control design.

Differentiation between Wild-Type Group A Rotaviruses and Vaccine Strains in Cases of Suspected Horizontal Transmission and Adverse Events Following Vaccination.

Human group A rotaviruses (RVA) are important enteric pathogens, as they are a leading cause of acute gastroenteritis (AGE) in children worldwide. Since 2013, the German Standing Committee on vaccination recommended the routine rotavirus vaccination for infants in Germany. While vaccination has significantly decreased RVA cases and worldwide mortality, in some cases, infants can develop acute gastroenteritis as an adverse reaction after immunization with an attenuated live vaccine. Pediatricians, as well as clinicians and diagnostic laboratories, contacted the Consultant Laboratory for Rotaviruses and inquired whether cases of RVA-positive AGE after vaccination were associated with vaccine or with wild-type RVA strains. A testing algorithm based on distinguishing PCRs and confirmative sequencing was designed, tested, and applied. Diagnostic samples from 68 vaccinated children and six cases where horizontal transmission was suspected were investigated in this study. Using a combination of real-time PCR, fragment-length analysis of amplicons from multiplex PCRs and confirmative sequencing, vaccine-like virus was detected in 46 samples and wild-type RVA was detected in 6 samples. Three mixed infections of vaccine and wild-type RVA were detectable, no RVA genome was found in 19 samples. High viral loads (>1.0 × 107 copies/g stool) were measured in most RVA-positive samples. Furthermore, information on co-infections with other AGE pathogens in the vaccinated study population was of interest. A commercial multiplex PCR and in-house PCRs revealed three co-infections of vaccinated infants with bacteria (two samples with Clostridioides difficile and one sample with enteropathogenic E. coli) and six co-infections with norovirus in a subset of the samples. Human astrovirus was detected in one sample, with suspected horizontal transmission. The cases of suspected horizontal transmission of vaccine RVA strains could not be confirmed, as they either involved wild-type RVA or were RVA negative. This study shows that RVA-positive AGE after vaccination is not necessarily associated with the vaccine strain and provides a reliable workflow to distinguish RVA vaccine strains from wild-type strains.

Human Astrovirus VA1 Encephalitis in Pediatric Patients With Cancer: Report of 2 Cases and Review of the Literature

Novel human astroviruses (HAstVs) have recently been implicated as rare causes of fatal encephalitis in immunocompromised patients, for which there is no proven treatment. We report 2 cases from our institution in which HAstV-VA1 was detected in the cerebrospinal fluid by metagenomic next-generation sequencing after the initial evaluation revealed no etiology.

Predicting the concentrations of enteric viruses in urban rivers running through the city center via an artificial neural network

Viral waterborne diseases are widespread in cities due largely to the occurrence of enteric viruses in urban rivers, which pose a significant concern to human health. Yet, the application of rapid detection technology for enteric viruses in environmental water remains undeveloped globally. Here, multiple linear regression (MLR) modeling and artificial neural network (ANN) modeling, which used frequently measured physicochemical parameters in river water, were constructed to predict the concentration of enteric viruses including human enteroviruses (EnVs), rotaviruses (HRVs), astroviruses (AstVs), noroviruses GⅡ (HuNoVs GⅡ), and adenoviruses (HAdVs) in rivers. After training, testing, and validating, ANN models showed better performance than any MLR model for predicting the viral concentration in Jinhe River. All determined R-values for ANN models exceeded 0.89, suggesting a strong correlation between the predicted and measured outputs for target enteric viruses. Furthermore, ANN models provided a better congruence between the observed and predicted concentrations of each virus than MLR models did. Together, these findings strongly suggest that ANN modeling can provide more accurate and timely predictions of viral concentrations based on frequent (or routine) measurements of physicochemical parameters in river water, which would improve assessments of waterborne disease prevalence in cities.

The Capsid Precursor Protein of Astrovirus VA1 Is Proteolytically Processed Intracellularly.

Human astrovirus VA1 has been associated with neurological disease in immunocompromised patients, and its recent propagation in cell culture has opened the possibility to study its biology. Unlike classical human astroviruses, VA1 growth was found to be independent of trypsin during virus replication in vitro. In this work, we show that despite its independence on trypsin activation for cell infection, the VA1 capsid precursor protein, of 86 kDa (VP86), is processed intracellularly, and this proteolytic processing is important for astrovirus VA1 infectivity. Antibodies raised against different regions of the capsid precursor showed that the polyprotein can be processed starting at either its amino- or carboxy-terminal end, and they allowed us to identify those proteins of about 33 (VP33) and 38 (VP38) kDa constitute the core and the spike proteins of the mature infectious virus particles, respectively. The amino-terminal end of the spike protein was found to be Thr-348. Whether the protease involved in intracellular cleavage of the capsid precursor is of viral or cellular origin remains to be determined, but the cleavage is independent of caspases. Also, trypsin is able to degrade the capsid precursor but has no effect on VP33 and VP38 proteins when assembled into virus particles. These studies provide the basis for advancement of the knowledge of astrovirus VA1 cell entry and replication. IMPORTANCE Human astrovirus VA1 has been associated with neurological disease in immunocompromised patients. Its recent propagation in cell culture has facilitated the study of its biology. In this work, we show that despite the ability of this virus to grow in the absence of trypsin, a marked feature of human classical astroviruses, the capsid precursor protein of astrovirus VA1 is cleaved intracellularly to yield the mature infectious particles, formed by two polypeptides, VP33 that constitutes the core domain of the virus particle, and VP38 that forms the spike of the virus. These studies provide a platform to advance our knowledge on astrovirus VA1 cell entry and replication.

The Association of Human Astrovirus with Extracellular Vesicles Facilitates Cell Infection and Protects the Virus from Neutralizing Antibodies.

Viral gastroenteritis has a global distribution and represents a high risk for vulnerable population and children under 5 years due to acute diarrhea, fever and dehydration. Human astroviruses (HAstV) have been identified as the third most important cause of viral gastroenteritis in pediatric and immunocompromised patients. Furthermore, HAstV has been reported in biopsies taken from patients with encephalitis, meningitis and acute respiratory infection, yet it is not clear how the virus reaches these organs. In this work we have tested the possibility that the released astrovirus particles could be associated with extracellular vesicles. Comparison between vesicles purified from HAstV Yuc8 infected and mock-infected cells showed that infection enhances production of vesicles larger than 150 nm. These vesicles contain CD63 and Alix, two markers of vesicular structures. Almost 70% of the extracellular virus present in clarified supernatant at 18 h postinfection was found associated with vesicular membranes, and this association facilitates cell infection in the absence of trypsin activation and protects virions from neutralizing antibodies. Our findings suggest a new pathway for HAstV spread and might represent an explanation for the extra-intestinal presence of some astrovirus strains. IMPORTANCE Astroviruses are an important cause of diarrhea in vulnerable population, particularly children; recently some reports have found these viruses in extra-intestinal organs, including the central nervous system, causing unexpected clinical disease. In this work, we found that human astrovirus strain Yuc8 associates with extracellular vesicles, possibly during or after their cell egress. The association with vesicles doubled astrovirus infectivity in less susceptible cells and rendered virus particles insensitive to neutralization by antibodies. These data suggest that extracellular vesicles could represent a novel pathway for astrovirus to disseminate outside the gastrointestinal tract.

Detection of Novel Human Astrovirus MLB1 by a Commercial Viral Gastroenteritis Multiplex Assay

Detection of Novel Human Astrovirus MLB1 by a Commercial Viral Gastroenteritis Multiplex Assay

Detection of multiple human astroviruses in sewage by next generation sequencing

Human astrovirus (HAstV) composes of classic HAstV serotypes 1–8 and recently discovered novel HAstV-MLB and HAstV-VA strains. A number of studies have demonstrated that wastewater analysis is an effective approach to understand the prevalence and diversity of enteric viruses in local population. However, a comprehensive analysis of classic and novel HAstVs in sewage is still lacking. In this study, sewage samples were collected monthly from Jinan, China during 2018–2019. Quantification of HAstV genomes was performed by real-time quantitative PCR. Different from previous studies which focused on partial ORF1b or ORF2 gene, complete ORF2 region of HAstV was amplified from sewage concentrates, and amplicons were subjected to next generation sequencing (NGS) and genetic analysis. This methodology allowed detection of 18 astroviruses, of which 7 (HAstV-1, -2, -4, -5, VA1, VA2, and VA3) were detected in all sewage samples. A new strain VA6 mapped to the HMO clade was identified in 20.8% of samples, with 82.4%–83.3% nucleotide identities to the closest strain VA5. The viral load of classic, MLB and VA clades in sewage samples ranged from 3.7 × 104 to 4.6 × 107, 3.4 × 104 to 3.9 × 106, and 3.3 × 104 to 4.1 × 106 copies per liter, respectively. Phylogenetic analysis based on complete ORF2 region reflected local HAstVs within each genotype constituted multiple co-circulating lineages. Existence of several new lineages composed exclusively or predominantly of Chinese sequences was observed as well. These results demonstrate sewage contains astroviruses with considerable high diversities. NGS based environmental surveillance greatly improves the understanding of HAstV circulation and should be encouraged.

Inactivation of foodborne viruses by the cold plasma technology

Cold plasma (CP) is an innovative non-thermal food processing method. CP refers to a partially or completely ionized gas containing reactive chemical species, which are active against microorganisms, including viruses or enzymes of foods. CP has a minimal effect on the quality attributes of foods and can also elongate the shelf life of foods. Foodborne outbreaks caused by viruses have been increased in various countries in recent years. The research works on the inactivation effect of CP against viruses including foodborne viruses have been also increased in recent years. The most important foodborne viruses are human norovirus (HuNoV) and hepatitis A virus (HAV), involved in several outbreaks worldwide. Human astrovirus (HAstV), human adenovirus (HuAdV), Aichi virus (AiV), sapovirus (SaV) and enterovirus (EV) are also notable foodborne viruses and were associated in sporadic cases. The CP treatment proved efficient for the inactivation of foodborne viruses such as HuNoV and HAV. The present work reviews the CP as a non-thermal food processing technology and present the published data on the effect of CP process on foodborne viruses in foods.

Astrovirus-induced epithelial-mesenchymal transition via activated TGF-β increases viral replication.

Human astroviruses (HAstV), positive sense single-stranded RNA viruses, are one of the leading causes of diarrhea worldwide. Despite their high prevalence, the cellular mechanisms of astrovirus pathogenesis remain ill-defined. Previous studies showed HAstV increased epithelial barrier permeability by causing a re-localization of the tight junction protein, occludin. In these studies, we demonstrate that HAstV replication induces epithelial-mesenchymal transition (EMT), by upregulating the transcription of EMT-related genes within 8 hours post-infection (hpi), followed by the loss of cell-cell contacts and disruption of polarity by 24 hpi. While multiple classical HAstV serotypes, including clinical isolates, induce EMT, the non-classical genotype HAstV-VA1 and two strains of reovirus are incapable of inducing EMT. Unlike the re-localization of tight junction proteins, HAstV-induced EMT requires productive replication and is dependent transforming growth factor-β (TGF-β) activity. Finally, inhibiting TGF-β signaling and EMT reduces viral replication, highlighting its importance in the viral life cycle. This finding puts classical strains of HAstV-1 in an exclusive group of non-oncogenic viruses triggering EMT.

Monitoring Human Viral Pathogens Reveals Potential Hazard for Treated Wastewater Discharge or Reuse

Wastewater discharge to the environment or its reuse after sanitization poses a concern for public health given the risk of transmission of human viral diseases. However, estimating the viral infectivity along the wastewater cycle presents technical challenges and still remains underexplored. Recently, human-associated crAssphage has been investigated to serve as viral pathogen indicator to monitor fecal impacted water bodies, even though its assessment as biomarker for infectious enteric viruses has not been explored yet. To this end, the occurrence of potentially infectious norovirus genogroup I (GI), norovirus GII, hepatitis A virus (HAV), rotavirus A (RV), and human astrovirus (HAstV) along with crAssphage was investigated in influent and effluent water sampled in four wastewater treatment plants (WWTPs) over 1 year by a PMAxx-based capsid integrity RT-qPCR assay. Moreover, influent and effluent samples of a selected WWTP were additionally assayed by an in situ capture RT-qPCR assay (ISC-RT-qPCR) as estimate for viral infectivity in alternative to PMAxx-RT-qPCR. Overall, our results showed lower viral occurrence and concentration assessed by ISC-RT-qPCR than PMAxx-RT-qPCR. Occurrence of potentially infectious enteric virus was estimated by PMAxx-RT-qPCR as 88–94% in influent and 46–67% in effluent wastewaters with mean titers ranging from 4.77 to 5.89, and from 3.86 to 4.97 log10 GC/L, with the exception of HAV that was sporadically detected. All samples tested positive for crAssphage at concentration ranging from 7.41 to 9.99 log10 GC/L in influent and from 4.56 to 6.96 log10 GC/L in effluent wastewater, showing higher mean concentration than targeted enteric viruses. Data obtained by PMAxx-RT-qPCR showed that crAssphage strongly correlated with norovirus GII (ρ = 0.67, p < 0.05) and weakly with HAstV and RV (ρ = 0.25–0.30, p < 0.05) in influent samples. In effluent wastewater, weak (ρ = 0.27–0.38, p < 0.05) to moderate (ρ = 0.47–0.48, p < 0.05) correlations between crAssphage and targeted viruses were observed. Overall, these results corroborate crAssphage as an indicator for fecal contamination in wastewater but a poor marker for either viral occurrence and viral integrity/infectivity. Despite the viral load reductions detected in effluent compared to influent wastewaters, the estimates of viral infectivity based on viability molecular methods might pose a concern for (re)-using of treated water.

Molecular Detection of Enteric Viruses in Under-Five Children with Diarrhea in Debre Tabor, Northwest Ethiopia.

BackgroundViral gastroenteritis belongs to the major public health problems of infant and children worldwide. The largest proportion of morbidity and mortality occurs in Sub-Saharan Africa.PurposeAimed to assess the burden and genetic diversity of enteric viruses among children with diarrhea.Patients and MethodsA cross-sectional study was undertaken from December 2015 to April 2016 in Debre Tabor. A total of thirty-eight children, who presented with diarrhea at Debre Tabor health centers, were included. Fecal samples were collected and screened for enteric viruses by RT-PCR. Data were analyzed using SPSS software. Descriptive summary techniques were used to display the findings.ResultsOut of thirty-eight children screened, 52.6% were positive for at least one enteric virus. Six (30.0%) of the children had mixed enteric virus infections. Human adenovirus (HAdV) 7 (18.4%) was predominant followed by noroviruses (NoVs) 5 (13.2%), enterovirus (EV) 5 (13.2%), rotavirus A (RVA) 4 (10.5%), human astrovirus (HAstV) 2 (5.3%), and human parechovirus (HPeV) 1 (2.6%). Overall, nineteen different types of enteric virus genotypes were identified. Diverse adenovirus within species A (HAdV-12,-31), B (HAdV-3), C (HAdV-2), and F (HAdV-4) were detected. Norovirus II (GII.4 and GII.6) and norovirus I (GI.2, GI.3, and GI.5) genotypes were found. Sapovirus genotypes within genogroup II (GII.1, GII.5, and GII.6) were identified. Wild-type rotavirus G9 and P[8] genotypes were detected in one of the rotavirus positive samples. Non-polio enteroviruses within species A (coxsackie A virus (CAV) 5, CAV6, and CAV14) and C (enterovirus (EV-C) 99) were also identified. In two of the fecal samples classic HAstV-2 was detected.ConclusionDiverse enteric viruses were detected in fecal samples from under-five children with diarrhea. The detection of heterogeneous enteric viruses in this small data set highlights the need for extended multicenter studies to describe the burden and genetic diversity of enteric virus.

Molecular Epidemiology of Human Adenovirus, Astrovirus, and Sapovirus Among Outpatient Children With Acute Diarrhea in Chongqing, China, 2017-2019.

ObjectiveTo investigate the epidemiology of human adenovirus (HAdV), human astrovirus (HAstV), and sapovirus (SaV), children with acute diarrhea in Chongqing, China from 2017 to 2019 were enrolled. Improved surveillance could provide better guidance for diarrhea prevention.MethodsBetween 2017 and 2019, fecal specimens were collected from children <14 years of age presenting with acute diarrhea for treatment at the outpatient department of the Children’s Hospital, Chongqing Medical University. Human HAdV in the fecal specimens was detected by PCR, while RT-PCR was adopted for the detection of HAstV and SaV.ResultsA total of 1,352 fecal specimens were screened in this study. The detection rate of HAdV was 4.44% (60/1352), HAstV was 2.81% (38/1352), and SaV was 1.04% (14/1352). The prevalence of enteric viruses in males was not significantly different to females (p > 0.05). We found 96.67% (58/60) of the HAdV-positive cases, 92.11% (35/38) of the HAstV-positive cases, and 100% (14/14) of the SaV-positive cases among the children under 4 years old. HAdV cases were identified throughout the year, while the infection of HAstV peaked from March to May every year. By contrast, SaV was detected in May, July, and from September to December. In total, 41 strains of HAdV-F were identified, including F41 (39/60) and F40 (2/60). Furthermore, A31, B3, B7, C1, C2, C5, and C6 were also detected in the study. In addition, we detected two genotypes of HAstV, HAstV-1 (34/38) and HAstV-5 (4/38), and two genotypes of SaV, GI0.1 (13/14), GI0.2 (1/14).ConclusionThe enteric viruses HAdV, HAstV, and SaV contribute to the overall burden of diarrhea in Chongqing, especially in children <4 years of age. Two genotypes were identified for HAstV (HAstV-1 and HAstV-5) and SaV (GI.1 and GI.2) with an additional nine genotypes detected in HAdV cases. While the F41 HAdV strain was predominant, HAdV-A31 was also detected in 10% of cases. The study results along with continuous surveillance of enteric viruses will aid in the design and implementation of future enteric vaccines and diarrhea mitigation strategies.

The EPICC Family of Anti-Inflammatory Peptides: Next Generation Peptides, Additional Mechanisms of Action, and In Vivo and Ex Vivo Efficacy.

The EPICC peptides are a family of peptides that have been developed from the sequence of the capsid protein of human astrovirus type 1 and previously shown to inhibit the classical and lectin pathways of complement. The EPICC peptides have been further optimized to increase aqueous solubility and identify additional mechanisms of action. Our laboratory has developed the lead EPICC molecule, PA-dPEG24 (also known as RLS-0071), which is composed of a 15 amino acid peptide with a C-terminal monodisperse 24-mer PEGylated moiety. RLS-0071 has been demonstrated to possess other mechanisms of action in addition to complement blockade that include the inhibition of neutrophil-driven myeloperoxidase (MPO) activity, inhibition of neutrophil extracellular trap (NET) formation as well as intrinsic antioxidant activity mediated by vicinal cysteine residues contained within the peptide sequence. RLS-0071 has been tested in various ex vivo and in vivo systems and has shown promise for the treatment of both immune-mediated hematological diseases where alterations in the classical complement pathway plays an important pathogenic role as well as in models of tissue-based diseases such as acute lung injury and hypoxic ischemic encephalopathy driven by both complement and neutrophil-mediated pathways (i.e., MPO activity and NET formation). Next generation EPICC peptides containing a sarcosine residue substitution in various positions within the peptide sequence possess aqueous solubility in the absence of PEGylation and demonstrate enhanced complement and neutrophil inhibitory activity compared to RLS-0071. This review details the development of the EPICC peptides, elucidation of their dual-acting complement and neutrophil inhibitory activities and efficacy in ex vivo systems using human clinical specimens and in vivo efficacy in animal disease models.