Virus Isolation and Animal Susceptibility - Influenza Viruses

Virus Isolation and Animal Susceptibility

Influenza viruses are isolated from respiratory secretions by growing in chick embryos or tissue cultures (monkey kidney or baboon kidney cell lines).

◗ Chick embryos

The influenza viruses grow in the allantoic and amniotic cavity of the chick embryos. After an incubation period of 3 days, the fluid is tested for hemagglutination activities of the viruses.

◗ Cell culture

Cell lines are widely used for culture of influenza viruses. They can grow in several primary and continuous cell lines. Rhesus Monkey kidney cell lines (LLC-MK2) and Madin–Darby canine kidney (MDCK) are the continuous cell lines frequently used to isolate influenza viruses.

◗ Laboratory animals

Human influenza virus causes experimental infections in a variety of animals. Intracerebral inoculation of mice by neuro-trophic strains produces fatal encephalitis. It causes an acute respiratory disease on intranasal inoculation in ferrets.