A family of very small (20–30 nm) ether-resistant, nonenveloped viruses having a core of positive sense single-stranded infectious RNA enclosed in a capsid of icosahedral symmetry with 60 capsomeres. Numerous species (including the polioviruses, coxsackieviruses, and echoviruses) are included in the family. There are five accepted genera : Enterovirus, Rhinovirus, Hepatovirus, Cardiovirus, and Aphthovirus. [It. piccolo, very small, + RNA + -viridae]
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Pi·cor·na·vi·ri·dae (.)pē-.kȯr-nə-'vir-ə-.dē n pl a family of small single-stranded RNA viruses that have an icosahedral virion with no envelope and that include the causative agents of avian encephalomyelitis, encephalomyocarditis, hepatitis A, poliomyelitis, foot-and-mouth disease, and hand, foot and mouth disease see coxsackievirus, echovirus, enterovirus, rhinovirus
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Pi·cor·na·vi·ri·dae (pĭ-kor″nə-virґĭ-de) the picornaviruses: a family of RNA viruses having a nonenveloped icosahedral virion 22–30 nm in diameter without surface features. The genome consists of a single molecule of positive-sense single-stranded RNA (MW approximately 2.5 Ч 106, size 7.2–8.5 kb). Viruses contain four major polypeptides and are resistant to lipid solvents but sensitive to ultraviolet radiation. Replication and assembly occur in the cytoplasm; virions are released by cell destruction. Host range is narrow and transmission is chiefly mechanical. Genera of medical or veterinary importance include Aphthovirus, Cardiovirus, Enterovirus, Hepatovirus, Parechovirus, and Rhinovirus.Medical dictionary. 2011.