China
Africa
Explore chapters and articles related to this topic
Ecology
Published in Paul Pumpens, Single-Stranded RNA Phages, 2020
The relationships between bacteriological and viral indicators of sewage pollution, including the FRNA phages, and environmental variables in coastal water and weather were studied in the bathing waters of Gipuzkoa, the Basque Country (Serrano et al. 1998; Ibarluzea et al. 2007). The fates of the FRNA phages and bacterial pollution indicators were compared in the Moselle River, France (Skraber et al. 2002). Large microbial source tracking, which included the FRNA phage genotyping, was performed at three French estuaries in Brittany and Normandy (Gourmelon et al. 2007). The FRNA phages were detected in 71% of water samples, and group II and III representatives were present in 64% of these water samples, mainly in areas downstream of urban activities. Group I was detected only in three sampling sites with sufficient phage concentrations, and no phage from group IV was detected in any of the water samples. Remarkably, when present, group I represented a high proportion of the total phages, namely 50%–100% of hybridized phages (Gourmelon et al. 2007). Later, an extensive study including detection of the FRNA phage groups was completed in the large Daoulas catchment, Brittany, on the west coast of France (Mauffret et al. 2012). The phage MS2 was monitored not long ago by large-scale survey in the Seine River, together with enteric viruses, such as adenovirus, aichivirus, astrovirus, cosavirus, enterovirus, hepatitis A and E viruses, norovirus of genogroups I and II, rotavirus A, and salivirus, highlighting therefore the health status of the local population (Prevost et al. 2015).
Enterovirus
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Taxonomically, the genus Enterovirus falls under the family Picornaviridae, which currently consists of 35 genera of small, nonenveloped, single-stranded positive-sense ribonucleic acid (RNA) viruses, including Ampivirus, Aphthovirus, Aquamavirus, Avihepatovirus, Avisivirus, Cardiovirus, Cosavirus, Dicipivirus, Enterovirus, Erbovirus, Gallivirus, Harkavirus, Hepatovirus, Hunnivirus, Kobuvirus, Kunsagivirus, Limnipivirus, Megrivirus, Mischivirus, Mosavirus, Oscivirus, Parechovirus, Pasivirus, Passerivirus, Potamipivirus, Rabovirus, Rosavirus, Sakobuvirus, Salivirus, Sapelovirus, Senecavirus, Sicinivirus, Teschovirus, Torchivirus, and Tremovirus [6,7].
Vaccines against gastroenteritis, current progress and challenges
Published in Gut Microbes, 2020
Hyesuk Seo, Qiangde Duan, Weiping Zhang
Progress has been also made in vaccine development for the other enteric viruses including astroviruses (Astroviridae), adenoviruses (Adenoviridae), and sapoviruses (Caliciviridae). Other Astroviridae members such as VA-Like and MLB-like astroviruses, Picornaviridae (silivirus, cosavirus), and Parvoviridae families (bocaviruses, bufaviruses) are also isolated from patients (usually in infants and children) with gastroenteritis. Several subunit vaccines have been investigated for prevention against astrovirus infections. In particular, a trivalent subunit vaccine for hepatitis E virus, norovirus, and astrovirus was generated by fusing together the dimeric P domains of the three viruses to form a tetramer.93 When intranasally administered to mice, this trivalent product induced significant neutralizing antibody responses to the P domains of all three viruses. Another subunit astrovirus vaccine candidate used the capsid protein (CP) of mink astrovirus elicited high levels of serum anti-CP antib odies and lymphoproliferation responses and also stimulated IFN-γ levels in mice.94 Importantly, it was observed that virus shedding was suppressed and clinical signs including severe diarrhea were reduced in the litters born to the immunized mink mothers when challenged with a heterogeneous astrovirus strain.94 Future human volunteer studies and clinical trials are needed to assess the efficacy of these vaccine candidates against viral gastroenteritis.
The potential of plant-made vaccines to fight picornavirus
Published in Expert Review of Vaccines, 2020
Omayra C. Bolaños-Martínez, Sergio Rosales-Mendoza
Picornaviridae is one of the largest viral families, which according to the International Committee on Taxonomy of Viruses (ICTV) comprise 35 genera enclosing 80 viral species; many other are on the list to be classified. All members are ~30-32 nm in diameter with an icosahedral structure composed of 60 identical units (protomers) [1]. The members of this family have a genome composed of a single-stranded, positive-sense, and non-segmented RNA; with a length ranging 6.7–10.1 kb. The ORF is flanked by two untranslated regions (UTR); with the 5´end containing diverse RNA secondary structures implicated in replication and associated with the VPg protein that plays an important role in translation. The 3´UTR contains a poly (A) tail that mimics mRNA from the host providing genome stability (Figure 1). Picornaviruses possess four capsid proteins having b-barrel folding and code for a polyprotein that is processed by virus-encoded cysteine proteinases; their replication is performed by an RNA-dependent RNA polymerase containing the YGDD sequence motif. Picornaviruses are transmitted through the oral-fecal or aerial routes and many of them affect humans and animals; causing subclinical infections, mild febrile illness, and mild diseases in the gastrointestinal or respiratory tracts; as well as severe heart, liver, and central nervous system diseases. Picornaviruses of the genera Cardiovirus, Cosavirus, Enterovirus, Hepatovirus, Kobuvirus, Parechovirus, and Salivirus infect humans [2].
Molecular characterisation of emerging pathogens of unexplained infectious disease syndromes
Published in Expert Review of Molecular Diagnostics, 2019
Xin Li, Susanna K. P. Lau, Patrick C. Y. Woo
In addition to the use of single or multiple gene amplification and sequencing, the use of deep sequencing has helped us make one step further in detection and characterization of emerging microbes causing unexplained infectious disease syndromes. In contrast to PCR/RT-PCR where part of the target gene sequence has to be known for the design of PCR primers, deep sequencing allows detection of microbes when we have minimal idea on which type of microorganism is involved, allowing pathogen identification and typing using a single protocol. For example, using unbiased high-throughput sequencing of random-primer PCR amplification products, increasing numbers of human viruses are identified to account for previously unexplained infectious conditions, including the transplant-associated arenavirus [53], cosavirus [54], klassevirus [55], Saffold virus [56], and novel members of polyomavirus, astrovirus, picobirnavirus, papillomavirus, and bocavirus [57–62]. High-throughput genomic approach also provides a useful tool for outbreak investigation, including identification of the infectious species, strain type, virulence factor, resistance mechanisms and tracking the transmission at hospital, community, or even global scale. In addition, genomic analysis allows the design of target-specific primers for rapid case identification and outbreak control. Well-known examples include hospital outbreaks of Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, and carbapenem-resistant Klebsiella pneumonia [63–65], and community outbreak of Shiga toxin-producing Escherichia coli O104:H4 in Germany in 2011 [66,67]. The cost of next-generation sequencing (NGS) has decreased dramatically in the past decade, allowing migration of this technology from the research field into the clinical microbiology or public health laboratories. More data on the correlation between metagenomic data and microbial phenotype, as well as lowering the instrument and running cost will enable wider adoption in routine clinical practice.