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[Electrophoretic and immunologic comparative analysis of Mycoplasma pneumoniae and Mycoplasma genitalium proteins]
1Zakład Bakteriologii PZH w Warszawie.
Abstract:
The Mycoplasma pneumoniae FH strain routinely used in our laboratory for over 25 years as antigen in serological tests, 2 reference M. pneumoniae strains from ATCC (29342 and M129) and 3 isolates of M. pneumoniae obtained in 1995 from pneumonia patients were compared by SDS-PAGE, complement fixation test (CFT) and by Western-immunoblotting against human and rabbit serum samples with high level of mycoplasmal antibodies. On SDS-PAGE all M. pneumoniae strains showed the same number of 23 polypeptides on the gel with identical molecular weights. The same strains on immunoblotting against human and rabbit serum samples showed six bands: 170, 89, 75, 55, 38 and 33 kDa with the strongest antibody staining in 170-(P1 protein) and 89-kDa bands. Because of its known antigenic relationships Mycoplasma genitalium was used for comparison. The pattern of M. genitalium proteins on SDS-PAGE was similar to pattern of M. pneumoniae but distinguishable. On immunoblotting six proteins of M. genitalium (135, 127, 110, 95, 75 and 45 kDa) reacted with human and rabbits immunoglobulins for M. pneumoniae antigens. Furthermore in complement fixation test both antigens, prepared from M. pneumoniae and M. genitalium, reacted as well with human and rabbit immunoglobulins for M. pneumoniae and with rabbit immunoglobulins for M. genitalium. These cross-reactions observed in serological techniques could give false positive results in routine diagnosis of M. pneumoniae infections. In such situations showing on immunoblott of presence in tested serum sample of antibodies to 170- and 89 kDa proteins could confirm M. pneumoniae infection.
Insights
This study compared Mycoplasma pneumoniae strains using SDS-PAGE and immunoblotting. Cross-reactions with Mycoplasma genitalium were observed, potentially causing false positives in diagnosing M. pneumoniae infections.
Area of Science:
- Microbiology
- Immunology
- Molecular Biology
Background:
- Mycoplasma pneumoniae is a common cause of respiratory infections.
- Accurate serological diagnosis is crucial for identifying M. pneumoniae infections.
- Cross-reactivity between Mycoplasma species can complicate diagnosis.
Purpose of the Study:
- To compare different strains of Mycoplasma pneumoniae.
- To investigate potential cross-reactions between Mycoplasma pneumoniae and Mycoplasma genitalium antigens.
- To identify specific Mycoplasma pneumoniae antigens for accurate serological diagnosis.
Main Methods:
- Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to analyze protein profiles.
- Complement fixation test (CFT) was employed to assess antigenic relationships.
- Western immunoblotting was performed using human and rabbit serum samples.
Main Results:
- All Mycoplasma pneumoniae strains exhibited identical protein profiles on SDS-PAGE.
- Immunoblotting revealed six common Mycoplasma pneumoniae antigen bands, with strongest reactivity to 170-kDa (P1 protein) and 89-kDa proteins.
- Mycoplasma genitalium showed cross-reactivity with Mycoplasma pneumoniae antigens in both immunoblotting and CFT, potentially leading to false positive results.
Conclusions:
- Cross-reactions between Mycoplasma pneumoniae and Mycoplasma genitalium can interfere with routine serological diagnosis.
- Detection of antibodies against specific Mycoplasma pneumoniae antigens (170-kDa and 89-kDa) can confirm M. pneumoniae infection.
- Further refinement of serological tests is needed to differentiate between Mycoplasma pneumoniae and Mycoplasma genitalium infections.