TABLE 2.

Cytopathogenic effect in standard cell cultures of human viral pathogens common in the United Statesa

VirusCytopathogenic effect in:Final identification of isolates
FibroblastsA549 cellsbRhMK cellsOtherc
AdenovirusSome produce clustersGrape-like clusters or “lacy” pattern; 5-8 daysSome produce clustersHNK: grape-like clusters; 5-7 daysIF for group, neutralization for type
CMVFoci of contiguous rounded cells; 10-30 daysNoneNoneUse shell vials for rapid detectionCPE alonee
EnterovirusesSome produce CPE, same as in RhMK cells; 2-5 daysInfrequent, degenerativeSmall, round cells with cytoplasmic tails; 2-5 daysIF for groups, neutralization for type
HSVRounded large cells; 2-6 daysRounded large cells; 1-4 daysSome produce CPE, same as in A549 cells, 4-8 daysRK or HNK: rounded large cells; 1-4 daysIF
Influenza virusNoneNoneUndifferentiated CPE, cellular granulation; 4-8 daysHAD-positive with GPIF
Parainfluenza virusNoneNoneRounded cells, some syncytia; 4-8 daysHAD-positive with GPIF
RhinovirusDegeneration, rounding; 7-10 daysNoneNoneIncubate fibroblasts at 33°CCPE onlyf (difficult to differentiate from enteroviruses)
RSVInfrequent, granular degenerationInfrequentSyncytia; 4-10 daysHEp-2d: syncytia; 4-10 daysIF
VZVSome CPE; small, round cells; 6-8 daysSmall, round cells; 6-8 daysNoneHNK: small, round cells; 6-8 daysIF
  • a Measles, mumps, and rubella viruses are seldom encountered in the United States at present. Measles virus produces large syncytia in RhMK cells in 7 to 10 days and is hemadsorption positive with Rh cells. Virus identification may be confirmed by IF. Mumps virus produces rounded cells with large syncytia in RhMK cells in 6 to 8 days and is hemadsorption positive with guinea pig erythrocytes, and its identification may be confirmed by IF. Rubella virus requires special cultures such as African green monkey kidney, rabbit kidney, or BSC-1 cells and does not produce CPE; special detection by interference challenge or another method is needed.

  • b Human lung carcinoma.

  • c GP, guinea pig erythrocytes; HAD, hemadsorption; HNK, human neonatal kidney cells, RK, rabbit kidney cells.

  • d Human laryngeal carcinoma.

  • e Some laboratories may base final identification of CMV on characteristic CPE alone. Others may inoculate shell vials and stain for CMV early antigen to confirm the identification.

  • f Some laboratories may base final identification of rhinovirus on CPE, which is similar to that of the enteroviruses but appears in fibroblast lines rather than RhMk cells. The term “rhino-like virus” is sometimes used for reporting when the identification is based on CPE alone. Others may test for acid lability to differentiate rhinoviruses from the enteroviruses.