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.