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Production by various Pseudomonas species of a factor modifying the enterobacterial common antigen
Abstract:
The enterobacterial common antigen (ECA) is a common determinant shared by almost all members of the family Enterobacteriaceae. The antigen modifies erythrocytes for agglutination by ECA antibodies. Previously it was reported that Pseudomonas aeruginosa produces a factor (PF) which destroys the erythrocyte-modifying capacity of ECA. The present investigation was undertaken to determine whether other species of this genus also produce PF. The passive bacterial hemagglutination and hemagglutination inhibition tests were used. It was observed that 47 strains belonging to 8 species of the genus Pseudomonas produce this factor and 34 strains representing 12 other species do not. Multiple strains of a given species gave concordant results. Mucoid variants of P. aeruginosa produced more of this factor than did nonmucoid isolates recovered from the identical sputum specimens from patients with cystic fibrosis. ECA treated with PF no longer modifies erythrocytes for agglutination by ECA antibodies and exerts less antibody-neutralizing capacity than untreated antigen.
Insights
Pseudomonas species produce a factor that inactivates the enterobacterial common antigen (ECA). This factor, found in 8 of 20 tested Pseudomonas species, impacts bacterial interactions and immune responses.
Area of Science:
- Microbiology
- Immunology
Background:
- Enterobacterial common antigen (ECA) is a shared determinant in Enterobacteriaceae, modifying erythrocytes for antibody agglutination.
- Pseudomonas aeruginosa produces a factor (PF) that diminishes ECA's erythrocyte-modifying capacity.
Purpose of the Study:
- To investigate the prevalence of PF production across different species within the Pseudomonas genus.
- To understand the impact of PF on ECA's function.
Main Methods:
- Passive bacterial hemagglutination assays.
- Hemagglutination inhibition tests.
- Comparison of mucoid and nonmucoid variants of P. aeruginosa.
Main Results:
- PF production was confirmed in 47 strains across 8 Pseudomonas species.
- 34 strains from 12 other species did not produce PF.
- Mucoid P. aeruginosa variants produced more PF than nonmucoid isolates.
- PF-treated ECA lost its erythrocyte-modifying ability and reduced antibody-neutralizing capacity.
Conclusions:
- Multiple Pseudomonas species produce a factor that inactivates ECA.
- PF production varies among Pseudomonas species and is higher in mucoid variants.
- This factor has implications for bacterial interactions and immune evasion strategies.