Laboratory diagnosis of Mycoplasma pneumoniae infection. 1. Direct detection of antigen in respiratory exudates by enzyme immunoassay.
Direct and indirect antigen capture enzyme immunoassays (Ag-EIA) have been developed for the detection of Mycoplasma pneumoniae in nasopharyngeal aspirates or sputum from respiratory infection. The sensitivity of the two Ag-EIA were similar, but the indirect method using polyclonal rabbit and guinea-pig antisera was more convenient. The Ag-EIA had a detection limit of 10(4-4.5) colony-forming units/ml of sample. It was specific for M. pneumoniae and gave a low level response with M. genitalium. There were no cross-reactions with 10 other species of mycoplasmas. Tests with a wide range of bacteria and chlamydia group antigen, representing agents sometimes found in the respiratory tract, were also negative. At the current level of development, the Ag-EIA detected about 90% of specimens that were also positive for culture; 43% of specimens from culture-negative--seropositive patients gave a positive result. The overall pattern of results indicated that while antigen detection is a quick and effective substitute for the slow culture method, serological examination for specific IgM antibody is also necessary to give a complete diagnostic coverage.
Kok
T W
TW
Division of Medical Virology, Institute of Medical and Veterinary Science, Adelaide.
Varkanis
G
G
Marmion
B P
BP
Martin
J
J
Esterman
A
A
D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000032:analysis*; D006801:Humans; D007124:Immunoenzyme Techniques; D009177:Mycoplasma pneumoniae / Q000276:immunology*; D009305:Nasopharynx / Q000382:microbiology; D011019:Pneumonia, Mycoplasma / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D012698:Serologic Tests; D013045:Species Specificity
D000942:Antigens, Bacterial