PRESUMPTIVE IDENTIFICATION OF COMMON ADENOVIRUS SEROTYPES BY THE DEVELOPMENT OF DIFFERENTIAL CYTOPATHIC EFFECTS IN THE HUMAN LUNG CARCINOMA-(A549) CELL-CULTURE

The neutralization test is commonly used in clinical virology laborato ries for the identification by serotype of adenovirus isolates. In an effort to conserve reagents and reduce the amount of time in the perfo rmance of this assay, we evaluated the significance of differential cy topathic effects for the presumptive identification of lower-numbered adenovirus serotypes that are commonly encountered in the clinical set ting. Utilizing the human lung carcinoma (A549) cell culture as our in dicator system, two viral induced monolayer degenerations (i.e., cytop athic effects or CPEs) were recognized. Among our wild and the laborat ory adapted (i.e., ATCC) adenovirus isolates tested in this study, ser otypes 1, 2, 4, 5, 6, 8, 11, 19, 21, 27, and 31 were expectedly charac terized by the typically enlarged, rounded, and refractile cells, whic h eventually aggregated into irregular 'grape-like' clusters. Adenovir us types 3 and 7, however, were characterized by the development of di stinct intranuclear inclusions, a flattening and then a web or net-lik e monolayer degeneration. Differences in the intensity of intranuclear granulation were related by electron microscopy to differences in the quantity of viral crystalline aggregates within the host cell nucleus . A presumptive identification of the commonly encountered adenovirus serotypes 3 and 7 prior to the performance of the neutralization test would result in a conservation of type-specific antiserum, a decreased use of cell cultures and medium, and lastly, reduced medical technolo gist workload.