[Mucous (M) mutants of enteropathogenic, septicemic and saprophytic E. coli (author's transl)]

Area of Science:

• Microbiology
• Bacteriology
• Molecular Biology

Background:

• Escherichia coli (E. coli) exists in various forms, including Smooth (S), Rough (R), and Mucoid (M) mutants.
• Understanding the characteristics of E. coli mutants is crucial for studying bacterial pathogenesis and host-pathogen interactions.

Purpose of the Study:

• To characterize Mucoid M mutants of E. coli isolated from different sources (enteropathogenic, septicemic, saprophytic).
• To investigate the enzymatic activity, biochemical properties, and antigenic-serological behavior of these E. coli M mutants.

Main Methods:

• Isolation of M mutants through prolonged culturing of E. coli strains in normal horse serum.
• Enzymatic-biochemical testing to assess enzyme activity.
• Antigenic-serological analysis using agglutination tests with homologous sera.
• Observation of colony morphology and reversion characteristics.

Main Results:

• Identified M mutants with full enzymatic activity, comparable to S and R forms.
• Observed M mutants with significantly reduced enzymatic activity.
• Found M mutants agglutinable by homologous sera at varying titers.
• Discovered a group of non-agglutinable M mutants, even after autoclaving.
• Noted reversion of some M mutants to S colonies with full biochemical and antigenic activity after extended broth culturing.

Conclusions:

• E. coli M mutants display diverse enzymatic and antigenic profiles.
• Some M mutants exhibit instability, capable of reverting to the S form.
• The non-agglutinable nature of certain M mutants suggests alterations in surface antigens.