A nucleotide sequence comparison of coxsackievirus B4 isolates from aquatic samples and clinical specimens

Abstract
SUMMARY Ten coxsackievirus B4 (CVB4) strains isolated from clinical and environmental sources in Northern Ireland in 1985–7, were compared at the nucleotide sequence level. Dideoxynucleotide sequencing of a polymerase chain reaction (PCR) amplified fragment, spanning the VP1/P2A genomic region, classified the isolates into two distinct groups or genotypes as defined by Rico-Hesse and colleagues for poliovirus type 1. Isolates within each group shared approximately 99% sequence identity at the nucleotide level whereas ≤86% sequence identity was shared between groups. One isolate derived from a clinical specimen in 1987 was grouped with six CVB4 isolates recovered from the aquatic environment in 1986–7. The second group comprised CVB4 isolates from clinical specimens in 1985–6. Both groups were different at the nucleotide level from the prototype strain isolated in 1950. It was concluded that the method could be used to sub-type CVB4 isolates and would be of value in epidemiological studies of CVB4. Predicted amino acid sequences revealed non-conservation of the tyrosine residue at the VP1/P2A cleavage site but were of little value in distinguishing CVB4 variants.