ORF3 protein, the single accessory protein encoded by porcine epidemic diarrhea virus (PEDV), is related to viral pathogenicity. In order to determine the cytoplasmic location signal of PEDV ORF3, we constructed a series of recombinant plasmids carrying full-length or truncated segments of PEDV DR13 ORF3 protein. When the acquired plasmids were transfected into Vero cells, expression and distribution of the EGFP-fused full-length ORF3 protein and its truncated forms in the cells were observed by laser confocal microscopy. The results showed that ORF3 protein or their truncated forms containing 40-91 aa segment including two transmembrane domains were localized in the cytoplasm, whereas ORF3 truncated peptides without the 40-91 aa segment were distributed in the whole cell (in both cytoplasm and nucleus). This suggests that the 40-91 aa is the key structural domain determining cytoplasmic location of PEDV ORF3 protein. The discovery provides reference for further clarifying intracellular transport and biological function of PEDV ORF3 protein.
Amino Acid Sequence ; Animals ; Chlorocebus aethiops ; Coronavirus Infections ; virology ; Cytoplasm ; virology ; Porcine epidemic diarrhea virus ; genetics ; Protein Domains ; Swine ; Vero Cells ; Viral Proteins ; chemistry ; metabolism

OBJECTIVES: To analyze the clinical characteristics of fecal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid-positive in patients with coronavirus dasease 2019 (COVID-19) and to provide a scientific basis for the prevention and control of this disease. METHODS: The clinical data of 16 patients with fecal SARS-CoV-2 nucleic acid positive, who hospitalized in the North Branch of the First Hospital of Changsha (Changsha Public Health Rescue Center) from January to February 2020, were retrospectively analyzed. Their clinical manifestations, laboratory data and imaging data were summarized. RESULTS: Among the 16 patients, there were 9 males (56.25%) and 7 females (43.75%), the ratio of males to females was 1∶1.29. The age of onset was (43.3±14.6) years. There were 15 patients with contact history of Wuhan, 1 patient with contact history of local patient.Twelve patients were common type (75%), and 4 patients were severe type (25%). Clinical symptoms included fever in 14 patients (87.5%), cough in 12 patients (75%), shortness of breath in 5 patients (31.25%), pharyngalgia in 10 patients (62.5%), fatigue in 7 patients (43.75%), and diarrhea in 4 patients (25%). There were 14 patients (87.5%) with normal or decreased white blood cell count, 11 patients (68.75%) with decreased lymphocyte count, 15 patients (93.75%) with increased erythrocyte sedimentation rate, 13 patients (81.25%) with increased hypersensitivity C-reactive protein, 5 patients (31.25%) with increased procalcitonin, and 8 patients (50%) with increased serum ferritin in peripheral blood, and stool routine was basically normal. Compared with the common type, there was significant difference in the white blood cell and lymphocyte counts in the severe type (<0.01); the infection indicators, such as hypersensitivity C-reactive protein and serum ferritin, were significantly increased, with significant difference (all <0.01); but the procalcitonin and erythrocyte sedimentation rate was not significantly different (both >0.05). Chest CT mainly showed patchy shadows and interstitial changes. According to imaging examination, 4 patients (25%) showed unilateral pneumonia and 12 patients (75%) showed bilateral pneumonia. CONCLUSIONS The patients have the clinical symptoms of COVID-19, but gastrointestinal symptoms (such as diarrhea) are more common, and the changes of white blood cell count, lymphocyte count, hypersensitivity C-reactive protein, ferritin are more obvious in severe patients.The positivity of fecal nucleic acid suggests the possibility of digestive tract transmission of SARS-CoV-2, and fecal nucleic acid testing can be used as a routine testing method in clinical practice.
Adult ; Betacoronavirus ; isolation & purification ; C-Reactive Protein ; analysis ; China ; Coronavirus Infections ; diagnosis ; physiopathology ; Diarrhea ; virology ; Feces ; virology ; Female ; Ferritins ; analysis ; Humans ; Leukocyte Count ; Male ; Middle Aged ; Pandemics ; Pneumonia, Viral ; diagnosis ; physiopathology ; Retrospective Studies

Porcine epidemic diarrhea virus (PEDV) is a highly infectious pathogen that can cause severe diseases in pigs and result in enormous economic losses in the worldwide swine industry. Previous studies revealed that PEDV exhibits an obvious capacity for modulating interferon (IFN) signaling or expression. The newly discovered type III IFN, which plays a crucial role in antiviral immunity, has strong antiviral activity against PEDV proliferation in IPEC-J2 cells. In this study, we aimed to investigate the effect of PEDV nucleocapsid (N) protein on type III IFN-λ. We found that the N proteins of ten PEDV strains isolated between 2013 and 2017 from different local farms shared high nucleotide identities, while the N protein of the CV777 vaccine strain formed a monophyletic branch in the phylogenetic tree. The N protein of the epidemic strain could antagonize type III IFN, but not type I or type II IFN expression induced by polyinosinic-polycytidylic acid (poly(I:C)) in IPEC-J2 cells. Subsequently, we demonstrated that the inhibition of poly(I:C)-induced IFN-λ3 production by PEDV N protein was dependent on the blocking of nuclear factor-κB (NF-κB) nuclear translocation. These findings might help increase understanding of the pathogenesis of PEDV and its mechanisms for evading the host immune response.
Active Transport, Cell Nucleus ; Animals ; Coronavirus Infections ; immunology ; veterinary ; virology ; Genes, Viral ; Host-Pathogen Interactions ; immunology ; Interferons ; antagonists & inhibitors ; biosynthesis ; genetics ; Interleukins ; antagonists & inhibitors ; biosynthesis ; genetics ; NF-kappa B ; metabolism ; Nucleocapsid Proteins ; genetics ; immunology ; physiology ; Porcine epidemic diarrhea virus ; genetics ; pathogenicity ; physiology ; Promoter Regions, Genetic ; Swine ; Swine Diseases ; immunology ; virology

Objective: To understand the etiological characteristics of bacterial diarrhea in different areas, including large cities, mid-sized/small cities and rural area, in China. Methods: A cross-sectional surveillance was conducted in 17 provinces of China from 2010 to 2014. The acute diarrhea outpatients were selected from clinics or hospitals in large cities, mid-sized/small cities, including rural-urban fringe zones, and rural areas. The demographical and clinical characteristics of the patients were collected by using questionnaire, and stool samples were taken from them for laboratory detection of 17 kinds of bacteria. The differences in pathogen positive rates (PPR) and pathogen spectrum across the cases from three-type areas were compared. The different infection risk in different cases were analyzed with unconditional logistic regression model. Results: In our study, we enrolled 9 253 cases from large cities, 5 138 cases from rural areas and 13 683 cases from midsized/small cites. The pathogen with largest differences in infection rate across the three-type areas was Shigella (S.) flexneri (rural area: 5.81%, mid-sized/small city: 2.78%, large city: 0.46%), followed by Aeromonas (A.) hydrophila (rural area: 2.14%, mid-sized/small city: 0.96%, large city: 0.48%). Compared with cases in large cities, the cases in mid-sized/small cities and rural areas had higher infection risks for S. flexneri (mid-sized/small city: OR=6.481, 95%CI: 4.666-9.002, rural area: OR=11.304, 95%CI: 8.018-15.938) and A. hydrophila (mid-sized/small city: OR=1.992, 95%CI:1.401-2.832, rural area: OR=4.083, 95%CI: 2.833-5.884). The constituent ratio of diarrheagenic Escherichia coli and Salmonella increased with the urbanization development, while the ratios of Shigella and A. hydrophila had an opposite trend. S. sonnei (60.00%) was the predominant serogroup of Shigella in urban infections, while S. flexneri (77.37%) was the predominant serogroup in rural infections. Conclusion: The differences in pathogen spectrum of bacterial diarrhea were obvious across large cities, mid-sized/small cities and rural areas in China, especially the differences in the infection rates of S. flexneri and A. hydrophila.
Adolescent ; Adult ; Bacterial Infections/microbiology* ; Child ; China/epidemiology* ; Cross-Sectional Studies ; Diarrhea/microbiology* ; Dysentery/epidemiology* ; Escherichia coli/pathogenicity* ; Feces/virology* ; Female ; Humans ; Male ; Middle Aged ; Prevalence ; Rural Population ; Salmonella/pathogenicity* ; Shigella/pathogenicity* ; Suburban Population ; Urban Population

BACKGROUNDAcute diarrhea remains the serious problem in developing countries, especially among children under 5 years of age. Currently, only two or three common diarrhea pathogens were screened at most hospitals in China. The aim of this study was to provide a wide variety of diarrhea pathogens and their antimicrobial resistance patterns in children under 5 years of age.

METHODSTotally 381 stool samples collected from Tongji Hospital between July 1, 2014 and June 30, 2015 were tested by culture and/or polymerase chain reaction for eight kinds of bacteria and five kinds of viruses. An antimicrobial sensitivity test was performed using dilution method recommended by the Clinical and Laboratory Standards Institute.

RESULTSViral infections were mainly identified in infants (0-11 months), whereas bacterial infections were more prevalent in the age of 24-59 months. About 69.8% of samples were positive for at least one pathogen, 51.7% of samples were virus positive, followed by bacteria positive cases (19.4%), and 12.6% of cases displayed co-infections with two viruses or a virus and a bacterium. Rotavirus was the most prevalent pathogen, followed closely by norovirus, while Salmonella was the most commonly isolated bacteria, followed by diarrheagenic Escherichia coli (DEC) and Campylobacter. More than 40% of Salmonella spp. and DEC isolates were resistant to first-line antibiotics (ampicillin, trimethoprim-sulfamethoxazole, and tetracycline). Around 10% of Salmonella spp. isolates were resistant to ceftriaxone and ciprofloxacin simultaneously. Campylobacter spp. displayed high resistance to ciprofloxacin but kept low resistance to azithromycin and doxycycline.

CONCLUSIONSThe etiology of acute diarrhea varies in children of different age groups. The high frequency of infection with viruses suggests the urgent demand for new viral vaccine development. Proper use of antibiotics in the treatment of acute diarrhea is crucial due to the high level of antibiotic resistance.

Acute Disease ; Anti-Bacterial Agents ; therapeutic use ; Azithromycin ; therapeutic use ; Campylobacter ; drug effects ; pathogenicity ; Child, Preschool ; China ; Ciprofloxacin ; therapeutic use ; Diarrhea ; drug therapy ; etiology ; microbiology ; virology ; Doxycycline ; therapeutic use ; Escherichia coli ; drug effects ; pathogenicity ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Salmonella ; drug effects ; pathogenicity

OBJECTIVETo investigate the prevalence of adenoviruses (AdV) and their genotypes in infants and young children with diarrhea.

METHODSA total of 380 children with diarrhea aged less than 3 years were enrolled. The genomic DNA was extracted from stool and PCR was used to detect AdV. Clone sequencing and genotyping were performed for DNA in AdV-positive specimens.

RESULTSAdV was detected in 24 out of 380 specimens, and the detection rate was 6.3% (24/380). A majority of children with positive AdV were aged 2-3 years. The viral sequence analysis of positive specimens showed that the detection rates of enteric AdV41 and non-enteric AdV were 4.2% (16/380) and 2.1% (8/380), respectively, and among the children with non-enteric AdV, there were 2 with AdV1, 2 with AdV2, 1 with AdV7, 2 with AdV12, and 1 with AdV31.

CONCLUSIONSDiarrhea caused by AdV is commonly seen in children aged 2-3 years, and AdV41 is the major predominant strain.

Adenoviridae ; classification ; genetics ; Child, Preschool ; Diarrhea ; virology ; Female ; Genotype ; Humans ; Infant ; Infant, Newborn ; Male

Norovirus (NoV) is a pathogen that commonly causes viral diarrhea in children. Studies indicate that NoV recognizes human histo-blood group antigens (HBGAs) as cell attachment factors. In order to explore the correlation between of NoV infection and HBGAs, a cross-sectional study was conducted in children less than five years old who were hospitalized with diarrhea in two areas of China between November 2014 and February 2015. Of the paired stool and saliva samples taken from 424 children, NoV was detected in 24 (6%) children, with viral genotypes GII.3 (n=5), GII.4 (n=14), GII.12 (n=1), and GII.17 (n=4). All of the individuals having NoV infection were either secretors (Lea-b+/Lex-y+) or partial secretors (Lea+b+/Lex+y+) except one GII.3 infection of a non-secretor (Lea+b-/Lex+y-). These results suggest that secretor positive is associated with NoV infection, although non-secretors are not absolutely protected from NoV infection.
Blood Group Antigens ; genetics ; Caliciviridae Infections ; blood ; complications ; virology ; Child, Preschool ; China ; Cross-Sectional Studies ; Diarrhea ; blood ; etiology ; virology ; Feces ; virology ; Gastroenteritis ; blood ; virology ; Genotype ; Humans ; Infant ; Norovirus ; physiology

The deltacoronavirus is a new member of the subfamily Coronaviridae of the family Coronaviridae. Deltacoronaviruses can infect birds and mammals. Deltacoronaviruses were detected in early 2007 in Asian leopard cats and Chinese ferret badgers. In 2014, porcine deltacoronavirus (PDCoV) infection spread rapidly in the USA. Moreover, cell culture-adapted PDCoV has been obtained from infected piglets. Animal experiments have confirmed that the isolated PDCoV is highly pathogenic and causes severe diarrhea in piglets. Thus, the PDCoV can be considered to be a good model to study the deltacoronavirus. In this review, we discuss the etiology, epidemiology, pathogenicity, culture, and diagnostic methods of the PDCoV.
Animals ; Coronavirus ; classification ; genetics ; isolation & purification ; Coronavirus Infections ; veterinary ; virology ; Diarrhea ; veterinary ; virology ; Phylogeny ; Swine ; Swine Diseases ; virology

We wished to select a cold-adapted genotype G1P[8] ZTR-68 rotavirus (China southwest strain) in MA104 cells for possible use as a live vaccine. ZTR-68 was recovered originally from children with diarrhea. The virus was cultivated at 37 degrees C at the first passage. Then, the cultivation temperature was decreased stepwise by 3 degrees C per eight passages. In total, the virus was passaged 32 times, and cultivation was terminated at 28 degrees C. Biological characteristics of the virus were analyzed during serial passages. There was no difference between the migration patterns of genomic dsRNA segments according to polyacrylamide gel electrophoresis of original and cold-adapted viruses. Infectious and red cell-agglutination titers of cold-adapted virus were lower than those of the parent virus. Also, the virus formed small-size plaques with irregular shapes at 31 degrees C and 28 degrees C. These results suggested that a genetically stable attenuated virus can be obtained through serial cold-adapted passages. Thus, an alternative strategy is provided by cold-adaption for development of attenuated live rotavirus vaccines.
Adaptation, Physiological ; China ; Cold Temperature ; Diarrhea ; virology ; Female ; Genotype ; Humans ; Infant ; Male ; Rotavirus ; genetics ; growth & development ; isolation & purification ; physiology ; Serial Passage ; Virus Cultivation ; Virus Replication

In this study, a novel resequencing pathogen microarray (RPM)-based multi-pathogen detection assay was developed to simultaneously detect 14 rotaviruses, 7 caliciviruses, 8 astroviruses, 28 enteroviruses, and 16 rare diarrhea viruses in patients with diarrhea syndrome. The specificity of the assay was examined using confirmed virus-positive specimens, and the sensitivity was evaluated by serial ten-fold dilutions of in vitro transcribed RNA. RPM assay could detect and differentiate virus types/subtypes at 20-2000 copies/microL. The detection threshold of RPM was determined by adjusting the reference concentration, and the detection steps were optimized to type Enterovirus. The nucleic acids of 10 stool samples from patients with unexplained diarrhea were screened, and 6 of them showed positive results. The RPM results were further verified by singleplex PCR followed by sequencing, and no difference was found between the two assays. In conclusion, we have established a high-throughput RPM assay with high specificity and sensitivity, which demonstrates a great potential for the identification of pathogens in patients with unexplained diarrhea and the management of emerging epidemic.
DNA Primers ; genetics ; Diarrhea ; virology ; Feces ; virology ; High-Throughput Screening Assays ; methods ; Humans ; Oligonucleotide Array Sequence Analysis ; methods ; Sensitivity and Specificity ; Viruses ; classification ; genetics ; isolation & purification