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Updated: Aug 13, 2026
Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction
Published on: May 28, 2012
Serological classification and epitope specificity of Proteus penneri S29 lipopolysaccharide
Krystyna Zych1, Małgorzata Siwińska, Zygmunt Sidorczyk
1Department of General Microbiology, Institute of Microbiology and Immunology, University of Łódź, Banacha 12/16, 90-237 Łódź, Poland.
Introduction:
Gram-negative bacteria of genus Proteus are common human intestinal and urinary tract pathogens. In the genus Proteus there are four clinically important named species: P. mirabilis, P. vulgaris, P. penneri, and P. hauseri, and three unnamed Proteus genomospecies: 4, 5, and 6. The clinical significance of P. penneri, described in 1982 as a new species, is poorly documented. The aim of this work is serological characterization and classification of a ceftriaxone-susceptible P. penneri S29 strain isolated from a 34-year-old patient with postneurosurgical meningitis. In this characterization we will also include a ceftriaxonresistant strain, P. penneri R15, isolated from the same patient after 12 days' treatment with ceftriaxon and other antibiotics.
Material/Methods:
Rabbit polyclonal O-antisera were obtained against these two strains and purified and lipopolysaccharides (LPS) were extracted from the bacterial mass of the P. penneri S29 and R15 strains. In the serological investigations the following tests were used: enzyme immunosorbent assay (EIA), passive immunohemolysis (PIH), inhibition of these tests, absorption of rabbit O-antisera with the respective LPS, and repeated PIH, SDS/PAGE, and Western blot techniques.
Results:
The serological studies of the LPS extracted from both P. penneri strains showed the identity of both preparations of O-polysaccharides from LPS. In P. penneri S29 O-antiserum, four different types of antibodies were described and characterized.
Conclusions:
Both investigated P. penneri S29 and R15 strains were classified to the Proteus O31ab serogroup.
Insights
This study serologically characterized two Proteus penneri strains, S29 and R15, isolated from a meningitis patient. Both strains were identified as belonging to the Proteus O31ab serogroup.
Area of Science:
- Clinical microbiology
- Immunology
- Bacteriology
Background:
- Proteus bacteria are common pathogens, with P. penneri being a less understood species.
- P. penneri strains S29 (ceftriaxone-susceptible) and R15 (ceftriaxone-resistant) were isolated from a meningitis patient.
- The clinical significance and serological classification of P. penneri require further investigation.
Purpose of the Study:
- To serologically characterize and classify two distinct P. penneri strains.
- To investigate the serological relationship between ceftriaxone-susceptible and resistant P. penneri isolates from the same patient.
Main Methods:
- Extraction of lipopolysaccharides (LPS) from P. penneri S29 and R15 strains.
- Generation of rabbit polyclonal O-antisera against the P. penneri strains.
- Serological analysis using enzyme immunosorbent assay (EIA), passive immunohemolysis (PIH), and Western blot techniques.
Main Results:
- Serological studies confirmed the identity of O-polysaccharides from both P. penneri strains.
- Four distinct antibody types were identified and characterized in P. penneri S29 O-antiserum.
- The LPS analysis revealed conserved serological properties between the susceptible and resistant strains.
Conclusions:
- Both P. penneri S29 and R15 strains were serologically classified into the Proteus O31ab serogroup.
- This classification provides a basis for understanding the serological diversity within P. penneri.
- The study highlights the utility of serological methods in bacterial classification and understanding antimicrobial resistance development.
