Investigation of fecal coliform and typical enteric virus in representative beaches of China

Through investigating ten recreational marine beaches in China, we aimed to detect the occurrence of human enteric viruses in coastal bathing beaches and find a correlationship, if any, between the presence of enteric viruses in surface seawater and the concentrations of fecal coliforms, the conventional indicator of fecal pollution. In this study, twenty seawater samples were assayed for fecal coliforms and human pathogenic enteric viruses （hepatitis A viruses, rotaviruses, polioviruses） analysis. Enteric viruses were detected by RT-PCR, in 20 sample sites, 5%, 40%, 40% were positive for the presence of human hepatitis A viruses, rotaviruses, polioviruses, respectively. Seven of 20 sites are suffering from severe fecal contamination, based on traditional plate counts of fecal coliform outnumbering the established thresholds for recreation. Additionally, statistical analysis presented that no correlation was found between bacterial indicators and viruses in surface seawaters. The data confirmed that indicator bacteria in water are not reflective of the presence of enteric viruses in marine waters. Thus, current recreational water quality standards of both bacterial and viral indices should be reevaluated.

Molecular Characterization of the Duck Enteritis Virus UL4 Gene

Duck enteritis virus(DEV) is a herpesvirus that causes an acute,contagious and fatal disease. In the present article,the DEV UL4 gene was cloned and sequenced from a vaccine virus. A degenerate oligonucleotide primer for the consensus site of herpesvirus UL3 gene and a specific primer located in UL5 were used in the polymerase chain reaction(PCR) to amplify a DNA product 2 086 bp in size. DNA sequence analysis revealed that a 714 bp open reading frame(ORF) of DEV encoding a 237 amino acid polypeptide is homologous to the family of herpesvirus UL4 proteins and therefore has been characterized as a DEV UL4 gene. Alignment of the DEV UL4 protein sequence with those of other alphaherpesviruses showed that 10 amino acid residues are completely conserved. Phylogenetic tree analysis showed that the seventeen alphaherpesviruses viruses analyzed were classified into four large groups,and the duck enteritis virus branched separately,closely related to the Mardiviruses group comprising Gallid herpesvirus 2(GaHV-2) ,Gallid herpesvirus 3(GaHV-3) and Meleagrid herpesvirus 1(MeHV-1) . The present study showed that the evolutionary relationship of the UL4 protein could be used for classification of alphaherpesviruses.

Diagnosis and Prevention of Duck Virus Enteritis

The characteristics of duck virus enteritis(DVE)are introduced from the aspects of pathogen,epidemiology,clinical symptoms,autopsy pathological changes,etc.,and clinical comprehensive diagnosis and laboratory diagnosis methods are given.The disease is distinguished from similar diseases including duck necrotic enteritis,duck candidiasis,duck hemorrhage,duck coccidiosis and duck vitamin A deficiency.Eventually,the prevention and treatment measures of the disease are put forward.

Occurrence of human pathogenic viruses in drinking water and in its sources:A review

Since many waterborne diseases are caused by human pathogenic viruses,virus monitoring of drinking water(DW)and DW sources is crucial for public health.Therefore,the aim of this review was to describe the occurrence of human pathogenic viruses in DW and DW sources;the occurrence of two viruses proposed as novel indicators of human faecal contamination(Peppermild mottle virus and Tobacco mosaic virus)was also reported.This research was focused on articles that assessed viral occurrence using molecular methods in the surface water used for DW production(SW-D),groundwater used for DW production(GW-D),DW and bottled-DW(BW).A total of 1544 studies published in the last 10 years were analysed,and 79 were ultimately included.In considering the detection methods,filtration is the most common concentration technique,while quantitative polymerase chain reaction is the most common quantification technique.Regarding virus occurrence in SW-D,GW-D,and DW,high percentages of positive samples were reported for adenovirus,polyomavirus and Pepper mild mottle virus.Viral genomes were frequently detected in SW-D and rarely in GW-D,suggesting that GW-D may be a safe DW source.Viral genomes were also detected in DW,posing a possible threat to human health.The lowest percentages of positive samples were found in Europe,while the highest were found in Asia and South America.Only three articles assessed viral occurrence in BW.This review highlights the lack of method standardization and the need for legislation updates.

Enteric transmission of transfusion-transmitted virus

Objective To detect the virus in the feces and sera of patients in an outbreak of enterically transmitted non-A,non-E hepatitis,and this review covers the epidemiologic features and experimental infection of this novel virus.Data sources Data sources come from our own work on this subject,published and unpublished.Study selection Mainly our own work is included,and related literature is collected.Results In an outbreak of enterically transmitted non-A-E hepatitis among students,a total of 381 cases (60.7%)were documented.Viral fragments identical to transfusion transmitted virus(TTV)were detected in both serum and stool samples.Asymptomatic virus carriers among the staff had positive serum(32.1%)and feces(24.6%),clearly a potential source of infection.This viral infection prevalence in 2 remote villages in northern and southern China was 9.2% and 10.6%,respectively,suggesting that China is an endemic area.In this study,groups of 3 Rhesus monkeys were infected via oral or intravenous inoculation with patient feces.Two additional monkeys were infected by passage.The virus was detected in serum,peripheral blood mononuclear cell(PBMC),liver,spleen and small intestine,while the virus positive single strand,which might be a replicative intermediate,was only in liver,intestine and PBMC of all animals.Conclusions This nonenveloped DNA virus might be transmitted both by blood and enteric routes.Considering its wide distribution and high prevalence,we suppose that nonparenteral transmission is more important.

Microbial sensing in the intestine

The gut microbiota plays a key role in host health and disease,particularly through their interactions with the immune system.Intestinal homeostasis is dependent on the symbiotic relationships between the host and the diverse gut microbiota,which is influenced by the highly co-evolved immune-microbiota interactions.The first step of the interaction between the host and the gut microbiota is the sensing of the gut microbes by the host immune system.In this review,we describe the cells of the host immune system and the proteins that sense the components and metabolites of the gut microbes.We further highlight the essential roles of pattern recognition receptors(PRRs),the G protein-coupled receptors(GPCRs),aryl hydrocarbon receptor(AHR)and the nuclear receptors expressed in the intestinal epithelial cells(IECs)and the intestine-resident immune cells.We also discuss the mechanisms by which the disruption of microbial sensing because of genetic or environmental factors causes human diseases such as the inflammatory bowel disease(IBD).