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Updated: Aug 9, 2026

Production and Visualization of Bacterial Spheroplasts and Protoplasts to Characterize Antimicrobial Peptide Localization
10:13

Production and Visualization of Bacterial Spheroplasts and Protoplasts to Characterize Antimicrobial Peptide Localization

Published on: August 11, 2018

Conditions affecting the viability of spheroplasts in urine

H Gnarpe1, L Edebo

  • 1Institute of Medical Microbiology, Department of Bacteriology, University of Uppsala, Uppsala, Sweden.

Infection and Immunity
|March 1, 1970
PubMed

Insights

Penicillin treatment at low pH protects bacteria like Escherichia coli from osmotic lysis. Under specific conditions, these bacteria can form L-type colonies, impacting penicillin therapy strategies.

Area of Science:

  • Microbiology
  • Bacterial Physiology
  • Antibiotic Action

Background:

  • Penicillin induces spheroplast formation in bacteria.
  • Spheroplasts are susceptible to osmotic lysis, especially at neutral pH.
  • Understanding bacterial response to penicillin under varying conditions is crucial.

Purpose of the Study:

  • To investigate the viability of penicillin-induced spheroplasts under hypotonic conditions and acidic pH.
  • To examine the morphological changes and growth of Escherichia coli and Proteus vulgaris in the presence of penicillin at low pH.
  • To discuss the implications of these findings for penicillin therapy.

Main Methods:

  • Induction of spheroplasts using penicillin in Escherichia coli and Proteus vulgaris.
  • Assessment of spheroplast viability in low osmolality media at acidic pH (5.0-5.5).
  • Cultivation of bacteria in liquid media and on hypotonic agar with penicillin at pH 5.0-5.2.

Main Results:

  • Penicillin-induced spheroplasts retained viability in low osmolality media at pH 5.0-5.5.
  • Escherichia coli maintained rod form without significant growth in liquid media with penicillin at pH 5.0.
  • Bacteria grew as L-type colonies on hypotonic agar with penicillin at pH 5.2.

Conclusions:

  • Acidic pH (5.0-5.5) enhances the osmotic resistance of penicillin-induced spheroplasts.
  • Penicillin's effect on bacterial morphology and growth is pH-dependent.
  • Findings suggest potential modifications to penicillin therapy to improve efficacy.

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