Throat swabs from patients with pharyngitis and sputum specimens from patients with atypical pneumonia were tested for the presence of a Mycoplasma pneumoniae polypeptide with a molecular weight of 43,000 with the use of an M. pneumoniae species-specific monoclonal antibody in an immunoblot assay. This 43,000-dalton polypeptide was detectable in 33 of 33 throat swabs from patients with pharyngitis that were positive for M. pneumoniae by conventional culture as well as a culture-amplified enzyme immunoassay. The 43,000-dalton polypeptide was also detected in three of three M. pneumoniae culture-positive sputum specimens. It was not detected in 3 sputum specimens culture-confirmed for Legionella pneumophila, 10 sputum specimens from normal persons, or 25 throat swabs also from normal persons. This immunoblot assay could be completed within five hours and may be an alternative method for detecting M. pneumoniae antigen directly in sputum or throat swab specimens.

A murine immunoglobulin GI monoclonal antibody was produced that binds to a protease-sensitive, periodate-insensitive epitope on a 43,000-molecular-weight Mycoplasma pneumoniae membrane polypeptide. The 43,000-molecular-weight polypeptide appeared to be a major antigenic component of M. pneumoniae, as determined by immunoblot analysis. This monoclonal antibody reacted with 33 different clinical isolates of M. pneumoniae, but not with normal-flora Mycoplasma species or 18 other microorganisms potentially inhabiting the normal or diseased human respiratory tract. This apparent species-specific monoclonal antibody may have application for the detection of M. pneumoniae antigen in clinical specimens.

No abstract

Calbiochem-Behring, Enzygnost-Rubella is an enzyme-linked immunosorbent assay (ELISA) for the determination of IgG antibodies to rubella virus. Two procedures, screening and quantitative, were used for the measurement of rubella antibodies in a characterized panel of sera and in random, premarital serum specimens. Using the screening procedure, no false-positive or false-negative results were observed in testing a panel of 40 sera previously characterized by human "O" cell and chick cell hemagglutination-inhibition (HI) tests. Additional testing of 323 random, premarital serum samples resulted in 99.4% agreement with HI tests in identifying positive and negative specimens. In the evaluation of the quantitative procedure, a coefficient of correlation (r) of 0.93 between ELISA titers and the geometric mean HI titers was obtained when testing the panel of 40 characterized sera. Furthermore, 100% agreement with HI test was obtained in the detection of titer rises in 20 pairs of acute and convalescent sera. The average within-run coefficients of variation for the screening and quantitative procedures were determined to be 11.2% and 15.6%, respectively. It is concluded that the Enzygnost-Rubella reagents are sensitive, specific, and provide objective means for assessing immunestatus and detecting rises in antibody titers to rubella virus.