Laboratory diagnosis ofMycoplasma pneumoniaeinfection: 1. Direct detection of antigen in respiratory exudates by enzyme immunoassay.

Abstract

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.

Laboratory diagnosis ofMycoplasma pneumoniaeinfection: 3. Detection of IgM antibodies toM. pneumoniaeby a modified indirect haemagglutination test

“…However Reagents & Quality Control, 61 C(olindale Avenue, London, NW9 5HT, or grown in the laboratory from prototype strains (1,16,17).…”

“…It is conveniently incorporated into a battery of CF tests and since some patients with 1M. pneumoniae infection present to the doctor in mid disease (1). it may give an answer more rapidly than the slow and insensitive culture method.…”

Development and evaluation of a loop-mediated isothermal amplification assay for rapid detection of Mycoplasma pneumoniae

“…Culture is time-consuming, taking several weeks to produce results and is relatively insensitive (Dorigo-Zetsma et al, 1999;Harris et al, 1988;Kok et al, 1988). Serological methods are insufficiently sensitive and require paired serum samples from the acute and convalescent phases of the disease, thus only allowing a retrospective diagnosis (Dorigo-Zetsma et al, 1999;Chia et al, 1988;Sillis, 1990;Fedorko et al, 1995).…”

Laboratory diagnosis ofMycoplasma pneumoniaeinfection: 2. Comparison of methods for the direct detection of specific antigen or nucleic acid sequences in respiratory exudates

“…In a previous paper (Kok et al 1988) we have outlined the clinical importance of Mycoplasma pneumoniae infection and the shortcomings of existing methods for its laboratory diagnosis. It also described the development and validation of an indirect enzyme immunoassay (Ag-EIA) for the detection of M. pneumoniae antigen in samples of nasopharyngeal mucus or sputum from suspected cases of infection.…”