Application of a solid-phase immunofluorometric assay to the selection of monoclonal antibody specific for the adenovirus group-reactive hexon antigen

Hexon denaturation of human adenoviruses by different groups of biocides

Human adenoviruses have often been used as surrogates for testing broad-spectrum virucidal efficacy of biocides. However, recent studies have shown that members of this group of viruses have quite different chemical sensitivities and only serotypes 5 and 44 can be recommended as model viruses. In this study, the hexon protein of the serotypes 1, 2, 5, 6 and 8 was exposed to biocides and subsequently detected by western blotting and the RPS Adeno Detector. Only peracetic acid (PAA) at a relatively high concentration of 0.5% led to complete denaturation of hexon protein within 60 min. This effect was uniform for all adenoviruses tested and was not observed after exposure to 0.05-2.5% povidone-iodine (PVP-I) or 0.7% formaldehyde. However, viral infectivity and genome integrity were influenced by PVP-I and formaldehyde and lower concentrations of PAA. In conclusion, the hexon protein of human adenoviruses shows an unexpectedly high and uniform resistance to chemical biocides. The different chemical sensitivities of adenoviruses cannot be explained by the sensitivity of this main structural compound, but the present findings provide new insights into the virucidal action of disinfectants.

Time-resolved fluoroimmunoassays with monoclonal antibodies for rapid identification of parainfluenza type 4 and mumps viruses

Monoclonal antibodies were prepared to the F and M proteins of parainfluenza 4A and 4B and to mumpsvirus to obtain reagents that could be configured into type-specific yet broadly-reactive IFA, EIA, and TR-FIA tests. Several antibodies to parainfluenza 4A also detected subtype 4B, although to a somewhat lower signal, and thus were well suited to generic parainfluenza type 4 tests that were comparable to similar tests previously described for parainfluenza types 1, 2, and 3. Monoclonals to subtype 4B were less able to detect 4A because of high background problems in one or another test. Monoclonals to mumpsvirus F protein were completely type-specific. These antibodies were screened by IFA and EIA for broad reactivity with diverse strains of each virus and were configured into optimized EIA and TR-FIA tests. The all-monoclonal tests were then compared to polyclonal tests in terms of their ability to detect virus in clinical specimens. The all-monoclonal TR-FIA was uniformly the most sensitive, detecting virus in 80% of culture-positive parainfluenza 4A specimens, 67% of parainfluenza 4B specimens, and 90% of mumps specimens, compared to 40-67% for the monoclonal EIA tests and 33-60% for the polyclonal EIA tests. For parainfluenza 4 TR-FIA, mean P/N values were 379 for subtype 4A cell culture fluids (228 for subtype 4B cultures) and 57 for 4A clinical specimens (43 for 4B specimens). For mumpsvirus TR-FIA, mean P/N values were 27 for culture fluids and 32 for clinical specimens. The sensitivities of the TR-FIA were determined with purified virus to be 0.28 ng virus per well for parainfluenza 4A and 0.70 ng virus per well for mumpsvirus.

An epidemic of adenovirus 7a infection in a neonatal nursery: course, morbidity, and management

An epidemic of adenovirus 7a in our neonatal intensive care nursery and intermediate care nursery in July and August 1987 caused the death of two patients. Significant symptomatic infection possibly due to the virus occurred in nine patients, ten staff, and three parents, of whom three patients, three staff, and one parent were positive by culture. As a direct consequence of the outbreak, 58 staff days of work were lost; the intensive care nursery had to be closed to admissions for 19 days and the intermediate care nursery for 14 days. Seventeen newborns were transferred to other hospitals and four mothers were sent elsewhere for delivery. Control measures, which included cohorting of patients, use of gloves, gowns and goggles, and exclusion of symptomatic staff from the unit, appeared effective. Rapid immunofluorescence testing of virological specimens was of little use in monitoring the outbreak, largely because of poor specimen quality. This outbreak further underlines the ease of transmission and high morbidity of neonatal adenovirus infection.

Comparison of monoclonal time-resolved fluoroimmunoassay with monoclonal capture-biotinylated detector enzyme immunoassay for adenovirus antigen detection

A sensitive time-resolved fluoroimmunoassay (TR-FIA), adapted from TR-FIA procedures already described, was developed with monoclonal antibodies and compared with several enzyme immunoassays (EIAs) for detecting adenovirus antigens in clinical specimens. The most sensitive EIA was an all-monoclonal assay with biotin-labeled detector antibody and streptavidin-peroxidase conjugate. All tests were evaluated with nasopharyngeal aspirate specimens from respiratory illness, with tissue homogenates from patients with systemic infection, and with stool specimens from gastrointestinal illnesses. For respiratory and tissue specimens, the TR-FIA detected adenovirus in 85% of the specimens positive by culture, which was a sensitivity similar to those of the all-monoclonal biotin-avidin EIA (79%) and the polyclonal-capture biotin-avidin EIA (88%). For stool specimens, the TR-FIA detected adenovirus in 100% of the specimens positive by culture, which was a decidedly higher sensitivity than either EIA format (78 and 75%, respectively). The TR-FIA was shown to be an efficient, flexible, and specific test for large numbers of clinical specimens.

Preparation and characterization of monoclonal antibodies to enteric adenovirus types 40 and 41

We have prepared monoclonal antibodies to each of the enteric adenoviruses types 40 and 41. Three different hybridoma cell lines were selected which produced antibody found to react by radioimmunoprecipitation with adenovirus (Ad) hexon antigens. One was specific for Ad 40, another for Ad 41, and a third one reacted with both types. When tested in an enzyme immunoassay against all 41 known human Ad types, the type-specific monoclonal antibody against Ad 40 reacted homotypically, as did the monoclonal antibody against Ad 41. In addition, these monoclonal antibodies neutralized the homologous enteric Ad type. The monoclonal antibody which reacted with both enteric Ad types also showed lower levels of reactivity with the group C adenoviruses types 2, 5, and 6. The monoclonal antibodies produced will provide a definitive means for rapid identification of specific Ad types, and will be useful in defining the relationship of enteric adenoviruses to other types.

Grouping of monoclonal antibodies to adenovirus hexons by their cross-reactivity

Thirty two mouse ascitic fluids containing monoclonal antibodies (MAbs) directed against the hexon of human adenovirus type 1 were examined. The type and degree of cross-reactivity (CR) of the MAbs were determined by ELISA and hemagglutination methods with 10 heterologous hexon types. The similarity and the dissimilarity of the MAbs was also characterized by the correlation coefficient calculated from their reactivity values. On the basis of these, the 32 MAbs could be divided into five groups and fourteen individual MAbs, which altogether recognized 19 distinct epitopes. One of the recognized epitopes is the genus specific epitope of adenovirus hexons; the others are interspecies specific ones which can be found on the surface of the different hexon types in characteristic, mosaic-like combinations. The type and degree of CR of the MAbs lead to the conclusion that there exists a close antigenic relationship among the members of subgenus C of human adenoviruses and there is also a definite antigenic relationship between subgenera C and D. Hexons belonging to the oncogenic subgenera A and B display a much looser antigenic relationship with subgenus C.