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Preparation of typing antisera specific for O antigens of Pseudomonas aeruginosa
Abstract:
Results of serotyping 966 clinical isolates of Pseudomonas aeruginosa showed that 72% agglutinated specifically in one or another of the 16 typing antisera, but 28% agglutinated in two or more and often in as many as 10 antisera; this polyagglutinability correlated with a high incidence of cross-reactivity among the antisera. Absorption of each typing antiserum with either cell suspensions of five O-type strains or with a suspension of a particular polyagglutinable strain (SMC 247) abolished cross-reactivity in the typing antisera without significantly reducing titers against the homologous strains. All but four of the polyagglutinable strains agglutinated specifically in one or another absorbed antisera. The cross-reactions of unabsorbed antisera were interpreted to have been caused by antibodies directed not against specific O antigens but against thermostable specificities that remain undefined.
Insights
Pseudomonas aeruginosa serotyping revealed polyagglutinability in 28% of isolates due to cross-reactive antisera. Absorption techniques resolved these cross-reactions, enabling specific O-antigen identification.
Area of Science:
- Microbiology
- Immunology
Background:
- Pseudomonas aeruginosa is an opportunistic pathogen.
- Accurate serotyping is crucial for epidemiological studies of P. aeruginosa.
Purpose of the Study:
- To investigate the cause of polyagglutinability and cross-reactivity in Pseudomonas aeruginosa serotyping.
- To develop a method to improve the specificity of P. aeruginosa serotyping.
Main Methods:
- Serotyping of 966 clinical isolates of P. aeruginosa using 16 typing antisera.
- Absorption of antisera with specific O-type strains or a polyagglutinable strain (SMC 247).
- Evaluation of agglutination patterns before and after antiserum absorption.
Main Results:
- 72% of isolates showed specific agglutination, while 28% were polyagglutinable.
- Polyagglutinability correlated with high cross-reactivity among antisera.
- Antiserum absorption eliminated cross-reactivity, allowing specific identification of most polyagglutinable strains.
Conclusions:
- Cross-reactivity in P. aeruginosa serotyping is caused by antibodies to undefined thermostable specificities, not specific O antigens.
- Antiserum absorption is an effective method to improve the specificity of P. aeruginosa serotyping.
- This method enhances the reliability of P. aeruginosa epidemiological studies.