Polioviruses

Polio vaccine Pokovims Poliovirus, type 1 Polishes... 

Figure 16.14 Schematic diagrams of three different viral coat proteins, viewed in approximately the same direction. Beta strands I through 8 form the common jelly roll barrel core, (a) Satellite tobacco necrosis virus coat protein, (b) Subunit VPl from poliovirus.

I ilman, D.J., et al. Structural factors that control conformational transitions and serotype specificity in type 3 poliovirus. EMBO J. 8 1567-1579, 1989. 

Hogle, J.M., Chow, M., Filman, D.J. Three-dimensional structure of poliovirus at 2.9 A resolution. Science 229 1358-1365, 1985. 

The circumstances under which water becomes contaminated are as varied as the ways water is taken internally. It is then conceivable that almost any virus could be transmitted through the water route. The increased use of water for recreational purposes increases the incidence of human contact with bodies of water and, consequently, with waterborne viruses and bacteria. The major waterborne viruses among pathogens, and the most likely candidates for water transmission, are the picornaviruses (from pico, meaning very small, and RNA, referring to the presence of nucleic acid). The characteristics of picornaviruses are shown in Table 1. Among the picornaviruses are the enteroviruses (polioviruses, coxsackieviruses. 

Ozone is more effective than chlorine in deactivating poliovirus, Cryptosporidium parvum, Giardia lamblia, and other protozoa. It also improves the color, taste, and odor of water dramatically. However, since no residual amount remains, it is always necessary to add a small amount of a more stable disinfectant as well (sodium hypochlorite, chlorine dioxide, etc.). 

Active immunization against poliovirus Rare malaise, nausea, diarrhea, fever Three doses 0.5 mL PO at specified intervals... 

Active immunizations for the poliovirus Same as for BCG vaccine Three doses of 0.5 mL SC at 2 months, 4 months, and 12-15 months chidren receive a booster dose before entering school... 

Vaccine diphtheria and tetanus toxoids and acellular pertussis adsorbed, hepatitis B (recombinant) and inactivated poliovirus combined Pediarix Active immunization against diphtheria, tetanus, pertussis and all known subtypes of hepatitis B virus, and poliomyelitis immunization Sfee adverse reactions against individual vaccines. Primary immunization series 3 doses of 0.5 mLat 6-to 8-week intervals IM (first dose is 2 months of age, but may be given as early as 6 weeks of age)... 

Some of the pathogens in Table 2, infect only humans (e.g., Vibrio cholerae. Salmonella typhi. Shigella dysenteriae, poliovirus, hepatitis A virus), whereas others, known as zoonotic, infect both humans and animals Salmonella no thypi. Shigella no dysenteriae, Campylobacter, enteropathogenic Escherichia coli such as for example the biotype 0157 H7, Cryptosporidium, etc.). The control of those that only infect humans is easier than the control of the zoonotic ones. Thus, some of them (S, typhi, S. dysenteriae, poliovirus, etc.) have practically been eradicated in many developed countries, whereas the eradication, and even the control below certain levels, of the zoonotic ones is a very difficult task. 

Rhinovirus, like poliovirus, synthesizes a large precursor protein from which all of the mature viral proteins are generated. Two viral proteases are involved in these cleavages 2A protease cleaves the polyprotein precursor at its own N terminus, while the 3C protease is responsible for additional cleavage events to generate the mature viral proteins. Both proteases can release themselves from the polyprotein precursor. Cleavage by 3C occurs between Gln/Gly, but flanking sequences affect efficiency (reviewed in Racaniello 2001). 

Figure 38-10. Picornavimses disrupt the 4F complex. The 4E-4G complex (4F) directs the 40S ribosomal subunit to the typical capped mRNA (see text). 4G alone is sufficient for targeting the 40S subunit to the internal ribosomal entry site (IRES) of viral mRNAs. To gain selective advantage, certain viruses (eg, poliovirus) have a protease that cleaves the 4E binding site from the amino terminal end of 4G. This truncated 4G can direct the 40S ribosomal subunit to mRNAs that have an IRES but not to those that have a cap. The widths of the arrows indicate the rate of translation initiation from the AUG codon in each example.

Whereas a bacterial cell like a staphylococcus might be lOOOnm in diameter, the largest of the human pathogenic viruses, the poxviruses, measure only 250 nm along their longest axis, and the smallest, the poliovirus, is only 28 nm in diameter. They are mostly, therefore, beyond the limit of resolution of the light microscope and have to be visualized with the electron microscope. 

Picomaviruses Poliovirus Naked icosahedral particles 28 nm in diameter One of a group of enteroviruses common in the gut of humans. The primary site of multiplication is the lymphoid tissue of the alimentary tract. Only rarely do they cause systemic infections or serious neurological conditions like encephalitis or poliomyelitis... 

Plaque assays, at present, apply to only a very limited number of viruses, e.g. poliovirus, herpes virus, human rotavirus. The principle ofthese assays is as follows test virus is dried on to coverslips which are immersed in various concentrations oftest disinfectant... 

Poliomyelitis (inactivated)t (Salktype) Human diploid cell cultures infected with each of the three serotypes of poliovirus 1 Clarification 2 Inactivation with formalin 3 Concentration 4 Blending of virus of each serotype Induction of antibodies to polioviruses in chicks or guinea-pigs Inoculation of cell cultures and monkey spinal cords to exclude live virus... 

Poliomyelitis (live or oral) (Sabin type) Cell cultures infected with attenuated poliovirus of each of the three serotypes 1 Clarification 2 Blending of virus of three serotypes in stabilizing medium Infectivity titration of each of three virus serotypes Test for attenuation by Inoculation of spinal cords of monkeys and comparison of lesions with those produced by a reference vaccine... 

Viral vaccines present problems of safety testing far more complex than those experienced with bacterial vaccines. With killed viral vaccines the potential hazards are those due to incomplete virus inactivation and the consequent presence of residual live virus in the preparation. The tests used to detect such live virus consist of the inoculation of susceptible tissue cultures and of susceptible animals. The cultures are examined for cytopathic effects and the animals for symptoms of disease and histological evidence of infection at autopsy. This test is of particular importance in inactivated poliomyelitis vaccine, the vaccine being injected intraspinally into monkeys. At autopsy, sections of brain and spinal cord are examined microscopically for the histological lesions indicative of proliferating poliovirus. 

Polio is the only disease, at present, for which both hve and killed vaccines compete. Since the introduction of the killed vims (Salk) in 1956 and the live attenuated virus (Sabin) in 1962 there has been a remaikable decline in the incidence of poliomyelitis (Fig. 16.1). The inactivated polio vaccine (TPV) contains formalin-killed poliovirus of all three serotypes. On injection, the vaccine stimulates the production of antibodies of the IgM and IgG class which neutrahze the vims in the second stage of infection. A course of three injections at monthly intervals produces long-lasting immunity to all three poliovirus types. 

The structure/activity relationships for the methisazone, 3a, derivatives against adenoviruses and poxviruses have been shown to be similar [78]. Pearson and Zimmerman [79] demonstrated that all three types of polioviruses are inhibited by 2-acetylpyridine JV-dibutylthiosemicarbazone, which is similar to 3a, by blocking viral RNA synthesis. A 3-substituted triazinoindole derivative of isatin was effective against several strains of rhinovirus in tissue culture the mechanism of action is unknown [80]. 

Rubella Vaccine, Live Mumps Vaccine, rDNA Hepatitis B Vaccine, Oral Poliovirus Vaccine, Erythropoietin, and Factor IX etcetera. 

Bae, J. and Schwab, K. J. (2008). Evaluation of murine norovirus, feline calicivirus, poliovirus, and MS2 as surrogates for human norovirus in a model of viral persistence in surface water and groundwater. Appl. Environ. Microbiol. 74, 477- 84. 

Kitajima, M., Tohya, Y., Matsubara, K., Haramoto, E., Utagawa, E., and Katayama, H. (2010). Chlorine inactivation of human norovirus, murine norovirus and poliovirus in drinking water. Lett. Appl. Microbiol. 51,119-121. 

Poliovirus, inactivated IPV 0.5 mL Intramuscular, subcutaneous Allergic reaction to neomycin, streptomycin, polymyxin B... 

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