The use of MDCK, MEK and LLC-MK2 cell lines with enzyme immunoassay for the isolation of influenza and parainfluenza viruses from clinical specimens.

Primary Monkey Kidney (PMK) epithelial cells or egg inoculation have been traditionally used for the culture of influenza and parainfluenza viruses. The high cost and variability of obtaining high quality PMK cells prompted us to investigate the use of other cell strains for the growth of these viruses. For this study we investigated three cell lines viz. MDCK, MEK and LLC-MK2 for the culture of influenza A and B and parainfluenza 1, 2 and 3 viruses. Clinical specimens were spun onto cell monolayers in microtitre wells. The growth of these viruses was then identified by specific antibodies in an enzyme immunoassay (EIA). The LLC-MK2 and MDCK cell lines were found to provide optimal growth of parainfluenza and influenza viruses respectively. During the period from November, 1990 to July, 1992, 6501 respiratory specimens were tested. There were 100 influenza A, 36 influenza B and 261 parainfluenza virus isolates. The influenza isolates were further subtyped by the WHO Influenza Reference Centre. The use of these cell lines and the EIA provided an effective method for the routine culture of these viruses.