Alternative cell line for virus isolation

A human lung carcinoma cell line (A549) was compared with various other cell lines to determine susceptibility to viral growth. In the first phase of the study, A549 cells were compared with human embryonic kidney (HEK) and cynomolgus monkey kidney (CMK) cells for isolation of upper-respiratory disease viruses by using 1,248 throat swab specimens from basic-combat trainees. Of the 552 virus isolates, 507 were adenoviruses, 41 were polioviruses, and 4 were herpes simplex viruses (HSV). Of the isolates, 518 (93.8%) were isolated in A549 cells, 480 (87.0%) were isolated in HEK cells, and 262 (47.5%) were isolated in CMK cells (P less than 0.001). In the second phase of the study, A549 cells were compared with a human diploid fibroblast cell strain (MRC-5) and Vero monkey kidney (VMK) cells for the isolation of HSV from 1,157 specimens submitted for culture. Of the 227 HSV isolates, 210 (92.5%) were isolated in A549 cells, 202 (89.0%) were isolated in VMK cells (P greater than 0.1 for A549 versus VMK cells), and 167 (73.6%) were isolated in MRC-5 cells (P less than 0.001 for A549 versus MRC-5 cells). These results suggest that A549 cells are more susceptible to adenovirus infection and at least as susceptible to HSV infection compared with the other cell cultures evaluated. Detracting factors for the use of A549 cells were a slight loss of sensitivity to adenovirus at passage 120 and a concurrent change in the morphology of the cells. The A549 cell line proved to be an efficient, practical, and economical alternative cell system for the isolation of adenovirus and HSV in particular. Initial indications are that other clinically significant viruses may be grown in A549 cells; however, additional studies need to be performed.