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Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction
04:25

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction

Published on: February 24, 2014

SEROLOGICAL RELATIONSHIP BETWEEN PNEUMOCOCCUS TYPE I AND AN ENCAPSULATED STRAIN OF ESCHERICHIA COLI

L A Barnes1, E C Wight

  • 1Antitoxin and Vaccine Laboratory, Massachusetts Department of Public Health, Boston.

The Journal of Experimental Medicine
|October 30, 2009
PubMed

Insights

This study details a specific Escherichia coli strain, showing hemolytic and pathogenic traits. It demonstrates heterogenetic specificity through unique serological reactions with Type I antipneumococcic serum.

Area of Science:

  • Microbiology
  • Immunology
  • Bacteriology

Background:

  • An encapsulated strain of Escherichia coli exhibiting hemolytic and pathogenic properties was isolated.
  • This isolate provides further evidence for the concept of heterogenetic specificity in microbial interactions.

Purpose of the Study:

  • To investigate the serological relationship between an encapsulated Escherichia coli strain and antipneumococcic serums.
  • To elucidate the nature of heterogenetic specificity using this specific bacterial isolate.

Main Methods:

  • Serological testing, including agglutination and precipitation assays.
  • Utilized various antipneumococcic horse and rabbit serums (Types I, II, III), normal horse serum, and immune horse serums.
  • Cross-reactivity tests were performed between the colon bacillus, Type I pneumococci, and their respective soluble substances.

Main Results:

  • The isolated Escherichia coli strain showed specific serological reactions exclusively with Type I antipneumococcic horse serum.
  • No agglutination occurred with Type I antipneumococcic rabbit serum, Types II and III antipneumococcic horse serums, or other tested serums.
  • Immune serum against the colon bacillus agglutinated the homologous organism and precipitated its soluble substance but did not cross-react with Type I pneumococci.

Conclusions:

  • The findings suggest a limited heterogenetic specificity between this Escherichia coli strain and Type I antipneumococcic horse serum.
  • This relationship is analogous to the known cross-reactivity between Type II pneumococcus and Friedländer's bacillus Type B.

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