SEQUENCE VARIATION IN THE HEMAGGLUTININ-NEURAMINIDASE GENE OF HUMAN PARAINFLUENZA VIRUS TYPE-3 ISOLATES IN THE UK

The sequence variation in a 934 base-pair region of the gene encoding the haemagglutinin-neuraminidase of five human parainfluenza virus typ e 3 (HPIV3) isolates was determined together with that of a prototype UK strain. All of the clinical isolates were from the Manchester area of the UK and were obtained in 1990, 1991 and 1993. The gene segment w as amplified by the polymerase chain reaction using HPIV3-specific oli gonucleotide primers. The nucleotide homology of the strains was high, around 99 % and specific differences in the UK sequences when compare d with that of the US prototype strain were identified. In addition, a number of isolate-specific differences were seen. No correlation was detected between the observed nucleotide mutations and the year of iso lation, which support the hypothesis that HPIV3 shows cocirculation of a heterogeneous population of viruses rather than varying with time i n a linear fashion. However, the data suggested that geographically-de fined genetic lineages of HPIV3 may exist.