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Microbial Food-borne Diseases Due to Climate Change
Published in Javid A. Parray, Suhaib A. Bandh, Nowsheen Shameem, Climate Change and Microbes, 2022
John Mohd War, Anees Un Nisa, Abdul Hamid Wani, Mohd Yaqub Bhat
Viruses are obligate parasitic infectious agents made of deoxyribose nucleic acid (DNA) or ribose nucleic acid (RNA) as a genetic material, fenced by a protein covering called capsid. Capsid is made of subunits termed as capsomeres. They are positioned between living and nonliving environments. They cannot multiply in outside environment like bacteria; they proliferate exclusively in living cells of other organisms and are responsible for the large number of diseases that may even cause the death of an organism. The transmission of viruses is mainly due personal contact, contaminated foods, and water or contact with inanimate objects. Food-borne transmission of virus occurs either by infected food handler that is not hygienic, or by contact of foods with human and animal sewages, polluted water or by animals (for zoonotic viruses) upon consuming animal origin products (meat, fishes, etc.) that are contaminated with virus (Vasickova et al., 2010). The main source of food-borne viruses are the human and animal intestines. The feces shed by the infected person becomes the sources of infection. A number of viruses linked with food-borne illness include Hepatitis A, Norovirus, Hepatitis E virus, Rotavirus, Astroviruses, Aichi virus, Coxsackievirus A and B, parvoviruses, adenoviruses serotypes 40 and 41, Sapoviruses, and other picornaviruses and enteroviruses (D’Souza et al., 2007; Jaykus et al., 2013).
Virus-Based Nanobiotechnology
Published in Yubing Xie, The Nanobiotechnology Handbook, 2012
Magnus Bergkvist, Brian A. Cohen
The structure of most viruses can be described simply as a protein shell, better known as a capsid, that surrounds and protects the genetic material during its transfer from one host cell to another. The simplest form of a capsid is one that self-assembles from multiple copies of one single coat protein component. One implication of the nanoscale size of viruses is that the genetic information that codes for the coat proteins must not overwhelm the genetic storage capacity afforded by the internal viral volume. The result of this constraint is that virus capsids are highly repetitive macromolecular structures.
Introduction to virology
Published in Amine Kamen, Laura Cervera, Bioprocessing of Viral Vaccines, 2023
A capsid is a protein shell required to protect the viral genome from host nucleases. For some viruses, during infection, the capsid is responsible for attachment to the specific receptors exposed on the host cellular surface. A capsid can be either single- or double-protein shells containing few structural proteins. Hence, multiple copies of the capsid must self-assemble to form the 3D capsid structure, allowing different viruses to have wide ranges of shape and structure.
Incorporating viruses into soil ecology: A new dimension to understand biogeochemical cycling
Published in Critical Reviews in Environmental Science and Technology, 2023
Xiaolong Liang, Mark Radosevich, Jennifer M. DeBruyn, Steven W. Wilhelm, Regan McDearis, Jie Zhuang
Viruses are composed of a protein capsid containing a DNA or RNA genome. Some viruses also include a lipid envelope, but the majority do not. The size of virus particles that infect prokaryotes (i.e., bacteriophages or phages) varies widely but most have viral capsid diameter ranging from 20 nm to 70 nm and the length up to 200 nm in the tailed phages. On the smaller end of the range, a single-stranded DNA phage, vBRpoMi-Mini, was observed by Zhan and Chen (2019) to have a 22 nm diameter and contains only four open reading frames in its genome. Viruses are the smallest biological agents in soil, and their volume is generally 8000–125,000 times smaller than the volume of bacterial cells (Kuzyakov & Mason-Jones, 2018). Some groups of viruses may be much larger than phages. The “giant viruses”, a unique group of nucleocytoplasmic large DNA viruses (NCLVDs) that are commonly found in aquatic environments, but were recently found in soil (Legendre et al., 2014; Rigou et al., 2022). Giant viruses have large particle sizes, ranging from around 100 nm to over 300 nm, and genome length up to ∼400 kb.
HIV-1 immature virion and other networks formation with simple patchy disks
Published in Molecular Physics, 2022
Anthony B. Gutiérrez, Brian Ignacio Machorro-Martínez, Jaqueline Quintana, Julio C. Armas-Pérez, Paola Mendoza, Juan Marcos Esparza Lucero, Gustavo A. Chapela
Virus capsids are closed structures formed by their proteins. Inside this structure they travel, in a protected way, from one host cell to another, carrying with them the genetic material necessary for their reproduction, spreading the infection [1]. There are two distinct phases in the formation of the capsid. First the proteins attach to the cell lipid wall forming a hexagonal lattice. These proteins take the surrounding membrane and detach from the host cell. This structure separates from the host cell forming an immature virion, which is a closed environment with the cell membrane and the attached hexagonal structure of the proteins. These are then cut in several sections and the middle one forms the mature capsid, encapsulating the reproductive materials of the virus. This mature structure is formed by, not only, a hexagonal lattice but also some pentagons (12 to be precise) to allow the capsid to close.
Chlorine and ozone disinfection and disinfection byproducts in postharvest food processing facilities: A review
Published in Critical Reviews in Environmental Science and Technology, 2022
Adam M.-A. Simpson, William A. Mitch
Despite more than 100 years of experience employing chlorine to control pathogens in drinking water, the detailed mechanisms responsible for microbial inactivation remain poorly understood. Viruses consist of genomic material surrounded by a protein-based capsid associated with attachment to hosts and injection of genomic material into hosts. Wigginton et al. (2012) found that roughly half of the inactivation of bacteriophage MS2 was associated with chlorine reactions with the genome, with the remainder attributable to chlorine reactions with proteins involved in injection of the genome. By comparison, all of the inactivation of MS2 by chlorine dioxide was attributable to reactions with proteins involved in attachment to the host. For UV disinfection, 80% of the inactivation was associated with UV-mediated alterations to the genome, and the remainder to modifications to proteins involved with genome injection. A similar study evaluated inactivation of phage Phi6, an enveloped virus containing an outer lipid layer (Ye et al., 2018). While inactivation was associated with alterations to the genome during UV disinfection, damage to proteins dominated inactivation by chlorine.