Mumps Virus: Properties of the Virus, Virus Isolation

Mumps Virus

Mumps is an acute infectious disease of children, character-ized by acute, nonsuppurative, painful swelling of the salivary glands, caused by mumps virus.

Properties of the Virus

◗ Morphology

Mumps virus shows following features:

·           Mumps virus is a typical paramyxovirus containing a single-stranded, negative-sense RNA surrounded by an envelope.

·           It has two major surface glycoproteins: (a) one with both hemagglutinin and neuraminidase and (b) the other with cell-fusion protein. 

·       The hemagglutinin agglutinates the RBCs of fowl, guinea pigs, humans, and many other species. The hemagglutina-tion is followed by hemolysis and elution at 37°C.

·           The F protein is responsible for fusion of lipid membrane of the virus to the host cell.

◗ Viral replication

Viral replication is similar to that of measles virus.

◗ Antigenic and genomic properties

Only one antigenic type of mumps virus is known. Neutralizing antibodies are produced against the hemagglutinin. It has an internal nucleocapsid soluble (S) antigen, which is detected by the complement fixation test.

◗ Other properties

The mumps virus is a heat-labile virus. It is sensitive to heat and rapidly inactivated at room temperature. Treatment with form-aldehyde, ether, or ultraviolet light also inactivates the virus. The virus can be stored for a longer period by lyophilization at 270°C.

Virus Isolation

◗ Cell culture

The virus grows well in PMK tissue culture, Hep-2 cells, and H292 cells. The CPE consists of multinucleated giant cells and acidophilic cytoplasmic inclusions. The growth of virus in the cells can be detected by direct immunofluorescence and hemadsorption. The virus also grows well in amniotic cavity of 6–8 days’ old embryonated egg.