Virus classification

When contemplating the problem of virus classification, we can be truly impressed with the enormous diversity of viruses. Undoubtedly, many new viruses are awaiting discovery, although most undiscovered viruses will probably be considered members of existing virus families. 

Antiviral agents, 3 135-182 77 867 HBV therapy, 3 153-159 HCV therapy, 3 159-164 HIV therapy, 3 146-153 nucleoside analogues, 3 142-145 viral infection process, 3 139-142 virus classification, 3 135-138 WNV therapy, 3 164-168 Antiwear lubricant additives, 75 213, 223-224... 

Terms used for virus classification related to the biological of interest and the manufacturing processing are relevant viruses, specific model viruses, and nonspecific model viruses. The first refers to a virus that is likely to be present in the initial crude starting biological material, the second is a model... 

In a brief book by former well-known herbalist and author Hanna Kroeger of Boulder, Colorado, titled Free Your Body of Tumors and Cysts, it was stated that tumors are caused by fungi as well as viruses. Among those caused by fungi she lists hard tumors, a tumor formed by the fungus maduromycates as found in India, and prostate cancer. As for the kinds caused by viruses, she lists the following four virus classifications papilloma and papilloma combined with Epstein-Barr, Epstein-Barr with herpes, herpes with another virus, and retroviruses. 

As classified in the Third Report of the International Committee on Taxonomy of Viruses Classification and Nomenclature of Viruses, R. E. F. Matthews (Ed.), Intervirology 12 (129-296), 1979. 

Matthews, R.KE, Ed., Third report of the international cottunittee on taxonomy of viruses classification... 

Fig. 1 Classification of viruses by their genome replication strategy according to Baltimore (Baltimore 1971), Examples for important human pathogens falling into the respective class are listed above, Black DNA, gray RNA arrows to the right (+) strand polarity (i,e, corresponding to mRNA) arrows to the left (—(strands asterisk enveloped viruses...

As we have noted, viruses can be classified into broad groups depending on their hosts. For instance, there are plant viruses, animal viruses, and bacterial viruses. A number of viruses infecting insects are also known and although viruses are known for fungi, protozoa, and algae, these viruses have been so little studied that no classification has been developed. In the present chapter, we discuss only the animal (primarily mammalian) and bacterial viruses, and we discuss here briefly how these two groups of viruses are classified. 

Classification of bacterial viruses In the bacterial viruses, a formal classification scheme is rarely used. Rather, each bacterial virus is designated in terms of its principal bacterial host, followed by an arbitrary alphanumeric. Thus, we speak of T4 virus of Escherichia coli or P22 virus of Salmonella typhimurium. An overview of some of the major types of bacterial viruses is given later. We should note, however, that although a bacterial virus may be designated in reference to its principal host, the actual host range of the virus may be broader. Thus, bacteriophage Mu, generally studied with Escherichia coli, also infects Citrobacter and Salmonella. 

Classification of animal viruses Most of the animal viruses which have been studied in any detail have been those which have been amenable to cultivation in cell cultures. As seen, animal viruses are known with either single-stranded or doublestranded DNA or RNA. Some animal viruses are enveloped, others are naked. Size varies greatly, from those large enough to be just visible in the light microscope, to those so tiny that they are hard to see well even in the electron microscope. In the following sections, we will discuss characteristics and manner of multiplication of some of the most important and best-studied animal viruses. 

Shanmukh, S. Jones, L. Zhao, Y. P. Driskell, J. D. Tripp, R. A. Dluhy, R. A., Identifica tion and classification of respiratory syncytial virus (RSV) strains by surface enhanced Raman spectroscopy and multivariate statistical techniques, Anal. Bioanal. Chem. 2008, 390, 1551 1555... 

The typical person is influenced by both an optimistic bias and an illusion of control (Frewer et al., 1994). When these are lost or compromised, panic can occur. While panic disorder can afflict an individual, panic also occurs as a collective phenomena. While it has been thought that emotional instability will lead some people to be more likely to panic, this is not always found. However, people who are emotionally unstable are more likely to attach importance to information provided during the crises than more emotionally stable individuals (Verbeke and Van Kenhove, 2002). Furthermore, some people are more likely to believe they are sick or affected than others. Feldman et al. (1999) examined the panic predisposition of people based on their classification by the big five personality factors. People were inoculated with a common cold virus, and those who were classified as neurotic were more likely to report unfounded illness and more symptoms than other groups. In contrast to this, openness to experience was associated with reporting unfounded symptoms in those with verifiable colds, whereas conscientiousness was associated with reporting unfounded illness in those who were not ill (Feldman et al, 1999). 

Hao M. Li Y. Wang Y. Zhang S. A classification study of respiratory syncytial virus (RSV) inhibitors by variable selection with random forest. International Journal of Molecular Sciences, 2011, 12 (2), 1259-1280. 

T. Hirschfeld, M. J. Block, and W. Mueller, Virometer An optical instrument for visual observation, measurement and classification of free viruses, J. Histochem. Cytochem. 25, 719-723 (1977). 

Virases are much simpler organisms than bacteria, and they are made from protein substances and nucleic acid. A single nucleoprotein molecule formed from molecules of nucleic acid that are chemically bound to a bulky protein molecule can be considered a simple viral particle. The protein molecule plays the role of a protective membrane. Thus the virus can be schematically described as a nucleic acid insert that is protected by a protein covering. A virus can contain either ribonucleic acid or deoxyribonucleic acid, but it never contains both of them together. The type of nucleic acid is the basis of one of the classifications of viruses. Viruses are obligatory intracellular parasites, which, upon entering a cell (i.e. after being infected) use many biochemical systems of the host cell. 

This classification is based on various criteria, including shape of the bacterium (rod, cocci) and the ability of the bacteria to be stained with a crystal violet-iodine complex in the presence of alcohol (Gram staining). This classification system also contains rickettsiae and chlamydiae both of these tend to be at the interface with viruses in that they are intracellular bacteria. 

Bhudevi, B. Weinstock, D. Fluorogenic RT-PCR assay (TaqMan) for detection and classification of bovine viral diarrhea virus. Vet. Microbiol. 2001, 33(1), 1-10. 

Several methods of viral classification are in use. Classification based upon epidemiological criteria, such as enteric or respiratory viruses, is useful, but of more significance are schemes based upon the morphology of the virion (symmetry, envelope, etc.) and lype of nucleic acid (DNA, RNA, number of strands, polarity, etc.)... 

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