BIOLOGY OF COXSACKIE-A VIRUSES

This chapter discusses the biology of coxsackie A viruses (CAV). Coxsackie A viruses are a large group of human pathogens that are classified together on the basis of their similar pathogenicity in suckling mice. However, this subgroup is highly diverse both in clinical and molecular terms. Some of the serotypes, including CAV-21 resemble polioviruses at the sequence level although they mainly cause mild respiratory infections. Because receptor specificity is determined by the capsid proteins, these viruses may represent recombinants between two virus groups. The other completely sequenced serotype, CAV-9 was found to be a close relative of the coxsackie B viruses. In dendrograms this virus cannot be distinguished from CBVs despite the fact that in newborn mice CAV-9 is able to show pathogenicity typical of coxsackie A viruses. This similarity in sequence terms provides the interesting possibility of studying the molecular basis of tissue tropism at the molecular level, because it is probable that recombinants between full-length infectious cDNA copies of CAV-9 and CBV genomes are viable. Diagnostic procedures used in the detection of CAVs are at present both laborious and ineffective. This is due to difficulties in growing most of the isolates using standard cell culture conditions and to the lack of standardized reagents for serological assays. © 1993, Academic Press Inc.