Sequence variation within the carboxyl terminus of the nucleoprotein gene of mumps virus strains.
BACKGROUND
On rare occasions, clinically apparent mumps virus infection and meningitis can be caused by vaccine virus as well as wild type strains. This has been shown by nucleotide sequencing of short regions of the viral genome.


OBJECTIVE
We wished to confirm and extended these findings by investigating for strain differences within the carboxyl terminus of the nucleoprotein (NP) gene, which is known to be highly variable amongst paramyxoviruses in general.


METHODS
A 576 bp carboxyterminal fragment of NP was amplified by reverse transcriptase (RT) PCR from several different strains and was sequenced directly.


RESULTS
Three Urabe vaccine variants and five clinical isolates previously classified as Urabe strains revealed the same carboxyterminal pattern for NP. Three other isolates and the Leningrad-3 vaccine strain showed characteristic differences of up to 5% compared to the Urabe strains, with U/C substitutions being predominant.


CONCLUSIONS
The carboxyterminal sequence of NP varies significantly between mumps virus strains such that it can be used for differentiating between vaccine and wild-type isolates.
Boriskin
Y S
YS
Department of Medical Microbiology, St. George's Hospital Medical School, London, UK.
Booth
J C
JC
Yamada
A
A