A rapid microscopic method for the confirmation of rhinoviruses in cell culture.

OBJECTIVE Culture-confirmation of rhinovirus is done using acid lability testing, a laborious and time-consuming method which delays the reporting of patient results by 1-2 days. A fluorescent monoclonal antibody pool (Light Diagnostics Pan-Enterovirus Blend; Millipore Inc., Temecula, Calif., USA) developed to identify various enterovirus isolates in culture was recently reported to also cross-react with rhinoviruses. We evaluated the use of this cross-reacting antibody, used in tandem with non-cross-reacting enterovirus antibodies (D(3) IFA; Diagnostic Hybrids Inc., Athens, Ohio, USA) to rapidly identify rhinoviruses in cell culture. METHODS Microscope slides were prepared from cell cultures of 11 rhinovirus clinical isolates and a variety of other respiratory viruses. Slides were stained using both enterovirus antibody pools and examined for fluorescent activity. RESULTS Positive fluorescence was observed in all the rhinovirus isolates tested using the pan-enterovirus antibody blend, but yielded negative results when stained using the D(3) antibodies. Both antibody products produced positive fluorescence for enterovirus isolates and produced negative results when a variety of other respiratory viruses were examined. CONCLUSION Staining suspected rhinovirus isolates with each antibody pool affords a rapid means of identifying rhinoviruses and distinguishing them from enteroviruses, without the need for acid lability testing.