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Introduction Group A rotaviruses (RVs) are non-enveloped, double-stranded, segmented RNA viruses with a triple-layered particle (TLP) composed of inner layer (VP2), intermedia layer (VP6), and outer layer (VP7, VP4) proteins [...], We previously generated 32 rotavirus-specific (RV-specific) recombinant monoclonal antibodies (mAbs) derived from B cells isolated from human intestinal resections. Twenty-four of these mAbs were specific for the [VP8.sup.*] fragment of RV VP4, and most (20 of 24) were non-neutralizing when tested in the conventional MA104 cell-based assay. We reexamined the ability of these mAbs to neutralize RVs in human intestinal epithelial cells, including ileal enteroids and HT-29 cells. Most (18 of 20) of the "non-neutralizing" [VP8.sup.*] mAbs efficiently neutralized human RV in HT-29 cells or enteroids. Serum RV neutralization titers in adults and infants were significantly higher in HT-29 than MA104 cells and adsorption of these sera with recombinant [VP8.sup.*] lowered the neutralization titers in HT-29 but not MA104 cells. [VP8.sup.*] mAbs also protected suckling mice from diarrhea in an in vivo challenge model. X-ray crystallographic analysis of one [VP8.sup.*] mAb (mAb9) in complex with human RV [VP8.sup.*] revealed that the mAb interaction site was distinct from the human histo-blood group antigen binding site. Since MA104 cells are the most commonly used cell line to detect anti-RV neutralization activity, these findings suggest that prior vaccine and other studies of human RV neutralization responses may have underestimated the contribution of [VP8.sup.*] antibodies to the overall neutralization titer. more...

Author(s): Charlotte Nyblade[sup.1], Viviana Parreno[sup.1,3], Peng Zhou[sup.1], Casey Hensley[sup.1], Vanessa Oakes[sup.1], Hassan M. Mahsoub[sup.1,4], Kelsey Kiley[sup.1], Maggie Frazier[sup.1], Annie Frazier[sup.1], Yongrong Zhang[sup.2], Hanping Feng[sup.2] and Lijuan Yuan[sup.1,4] Background Clostridioides difficile [...], Clostridioides difficile (C. difficile) is a gram-positive, spore-forming, anaerobic bacterium known to be the most common cause of hospital-acquired and antibiotic-associated diarrhea. C. difficile infection rates are on the rise worldwide and treatment options are limited, indicating a clear need for novel therapeutics. Gnotobiotic piglets are an excellent model to reproduce the acute pseudomembranous colitis (PMC) caused by C. difficile due to their physiological similarities to humans and high susceptibility to infection. Here, we established a gnotobiotic pig model of C. difficile infection and disease using a hypervirulent strain. C. difficile-infected pigs displayed classic signs of C. difficile infection, including severe diarrhea and weight loss. Inoculated pigs had severe gross and microscopic intestinal lesions. C. difficile infection caused an increase in pro-inflammatory cytokines in samples of serum, large intestinal contents, and pleural effusion. C. difficile spores and toxins were detected in the feces of inoculated animals as tested by anaerobic culture and cytotoxicity assays. Successful establishment of this model is key for future work as therapeutics can be evaluated in an environment that accurately mimics what happens in humans. The model is especially suitable for evaluating potential prophylactics and therapeutics, including vaccines and passive immune strategies. Keywords: Clostridioides difficile infection/illness (CDI), Gnotobiotic pigs, Pseudomembranous colitis (PMC) more...

Author(s): Weihong Li[sup.1], Hanqiu Yan[sup.1], Baiwei Liu[sup.1], Yi Tian[sup.1], Yanwei Chen[sup.1], Lei Jia[sup.1], Zhiyong Gao[sup.1] and Quanyi Wang[sup.1] Background Despite substantially decreased incidence in recent decades, diarrheal disease remains the [...], Background Human noroviruses are the leading cause of sporadic cases and outbreaks of viral acute gastroenteritis in all age groups worldwide. Methods Epidemiological data and fecal specimens were collected between January 2011 and December 2018 from 4911 children < 5 years of age with diarrhea in three districts of Beijing. From 2011 to 2013, One-Step Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to detect noroviruses, and from January 2014 to December 2018, norovirus GI and GII were screened using duplex quantitative real-time RT-PCR (qRT-PCR). One-Step RT-PCR and RT-seminested PCR were performed to amplify the RNA-dependent polymerase and capsid genes of noroviruses in positive sample. Amplified products were sequenced directly; norovirus was typed using the online Norovirus Genotyping Tool v2.0 and phylogenetic analyses were conducted using MEGA-X. Results From 2011 to 2018, noroviruses were detected in 16.5% of specimens from children with diarrhea. The highest prevalence was observed in children aged 12 to 23 months (22.4%, 319/1421), followed by children aged 6 to 11 months (17.6%, 253/1441). The highest prevalence of norovirus infections occurred in autumn followed by winter, spring, and summer. From 2011 to 2018, the most prevalent dual types (genotype and polymerase type) were GII.4 Sydney[P31] (51.6%, 239/463), followed by GII.3[P12] (24.0%, 111/463), GII.4 2006b[P4 2006b] (7.3%, 34/463), GII.2[P16] (5.0%, 23/463), GII.17[P17] (2.6%, 12/463) and GII.6[P7] (2.6%, 12/463). GII.4 2006b[P4 2006b] predominated in 2011 and 2012. GII.4 Sydney[P31] predominated from 2013 to 2018. In total, 15 genotypes, 15 P-types and 19 dual types were detected in this study, reflecting the genetic diversity. Conclusions There were significant epidemiological characteristics and genetic diversity among outpatient children with norovirus infections < 5 years of age in Beijing from 2011 to 2018. These characteristics differ from those of norovirus outbreaks in Beijing. The complete genome sequences of each genotype are needed to better understand norovirus evolutionary mechanisms. Keywords: Norovirus, Children, Outpatient, Diarrhea, Genotypes more...

Author(s): Aline Lamien-Meda[sup.1], Renate Schneider[sup.1], Julia Walochnik[sup.1], Herbert Auer[sup.1], Ursula Wiedermann[sup.1] and David Leitsch[sup.1] Background Human intestinal protozoan infections can lead to significant morbidity and mortality when not diagnosed timely [...], Background Intestinal parasitic diseases occur worldwide, and their diagnosis poses considerable challenges. Cryptosporidium spp., Entamoeba histolytica, Giardia intestinalis, (and, arguably, Dientamoeba fragilis and Blastocystis spp.) are among the most important and common parasitic protozoans causing diarrhea. Several multiplex real-time PCR assays have been developed for the synchronous detection of these parasites. However, most assays include the use of hydrolysis probes, increasing the cost of stool examination. In this study, we designed and evaluated a real-time PCR protocol, based on high-resolution melting (HRM) curve analysis, to simultaneously detect and differentiate five gastrointestinal parasites. Results Using a blinded panel of 143 clinical samples with laboratory diagnostic data to evaluate the method, we obtained a 95.8% concordance with conventional methods. Moreover, 4.2% of the samples were positive for D. fragilis and 2.8% additional Cryptosporidium infections were found with our multiplex assay. Our method is sensitive and specific for the selected parasites with the additional possibility of being run in single-plex as a backup control for mixed infections. Conclusions The assay is a convenient and cost-effective method that could contribute to a quicker and accurate diagnosis as well as to more targeted therapies of parasite-derived diarrhea. Finally, this new multiplex PCR assay could also be instrumental in epidemiology studies on these parasites. Keywords: Diarrhea, qPCR-HRM, Dientamoeba, Entamoeba, Cryptosporidium, Blastocystis, Giardia more...

Introduction Diarrhea is the fourth leading cause of death of children In India, diarrhea causes an estimated 3.65% of disability adjusted life-years (DALYs) lost (7.1% of DALYs lost in children [...], Background: The effects of weather on diarrhea could influence the health impacts of climate change. Children have the highest diarrhea incidence, especially in India, where many lack safe water and sanitation. Objectives: In a prospective cohort of 1,284 children under 5 y of age from 900 households across 25 villages in rural Tamil Nadu, India, we examined whether high temperature and heavy rainfall was associated with increased all-cause diarrhea and water contamination. Methods: Seven-day prevalence of diarrhea was assessed monthly for up to 12 visits from January 2008 to April 2009, and hydrogen sulfide ([H.sub.2]S) presence in drinking water, a fecal contamination indicator, was tested in a subset of households. We estimated associations between temperature and rainfall exposures and diarrhea and [H.sub.2]S using binomial regressions, adjusting for potential confounders, random effects for village, and autoregressive-1 error terms for study week. Results: There were 259 cases of diarrhea. The prevalence of diarrhea during the 7 d before visits was 2.95 times higher (95% CI: 1.99, 4.39) when mean temperature in the week before the 7-d recall was in the hottest versus the coolest quartile of weekly mean temperature during 1 December 2007 to 15 April 2009. Diarrhea prevalence was 1.50 times higher when the 3 weeks before the diarrhea recall period included >1 d (vs. 0 d) with rainfall of >16.82 mm (95% CI: 1.12, 2.02), and 2.60 times higher (95% CI: 1.55, 4.36) for heavy rain weeks following a 60-d dry period. The [H.sub.2]S prevalence in household water was not associated with heavy rain prior to sample collection. Conclusions: The results suggest that, in rural Tamil Nadu, heavy rainfall may wash pathogens that accumulate during dry weather into child contact. Higher temperatures were positively associated with diarrhea 1-3 weeks later. Our findings suggest that diarrhea morbidity could worsen under climate change without interventions to reduce enteric pathogen transmission through multiple pathways. https://doi.org/10.1289/EHP3711 more...

Porcine epidemic diarrhea (PED) is an acute and highly contagious enteric disease of swine that results in severe enteritis, diarrhea, vomiting, and dehydration (1). Porcine epidemic diarrhea virus (PEDV), the [...] more...

Porcine epidemic diarrhea virus (PEDV) is an alphacoronavirus that causes enteric disease in swine. The disease, PED, is characterized by acute vomiting and watery diarrhea and causes high mortality rates [...] more...

Porcine epidemic diarrhea (PED), a devastating swine disease, is characterized by watery diarrhea, followed by dehydration, and a high death rate among suckling pigs (1,2). The disease was first recognized [...] more...

The list of emerging viral pathogens is ever-changing. The recognition that an increasing number of diseases that were once unexplained are caused by infectious agents has increased substantially in recent [...] more...

In summer and autumn 2011, farmers and veterinarians in North Rhine-Westphalia, Germany, and in the Netherlands reported to the animal health services, local diagnostic laboratories, and national research institutes an [...] more...