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Updated: Oct 6, 2026

Use of Artificial Sputum Medium to Test Antibiotic Efficacy Against Pseudomonas aeruginosa in Conditions More Relevant to the Cystic Fibrosis Lung
07:46

Use of Artificial Sputum Medium to Test Antibiotic Efficacy Against Pseudomonas aeruginosa in Conditions More Relevant to the Cystic Fibrosis Lung

Published on: June 5, 2012

Small-colony variants of Pseudomonas aeruginosa in cystic fibrosis

S Häussler1, B Tümmler, H Weissbrodt

  • 1Institut für Medizinische Mikrobiologie, Medizinische Hochschule Hannover, Germany.

Clinical Infectious Diseases : an Official Publication of the Infectious Diseases Society of America
|October 26, 1999
PubMed

Insights

Small-colony variants (SCVs) of Pseudomonas aeruginosa were found in 33 cystic fibrosis patients. These SCVs are linked to poorer lung function and specific antibiotic treatments.

Area of Science:

  • Microbiology
  • Pulmonary Medicine
  • Infectious Diseases

Background:

  • Chronic Pseudomonas aeruginosa infection is common in cystic fibrosis (CF).
  • The mucoid phenotype is the most studied P. aeruginosa form in CF.
  • Small-colony variants (SCVs) represent an alternative phenotype of P. aeruginosa.

Purpose of the Study:

  • To investigate the prevalence of P. aeruginosa SCVs in CF patients.
  • To identify clinical factors associated with the presence of SCVs.
  • To analyze the antimicrobial susceptibility of SCVs compared to revertants.

Main Methods:

  • Respiratory specimens from 86 P. aeruginosa-positive CF patients were analyzed over 2 years.
  • Isolation and characterization of P. aeruginosa SCVs and their revertants.
  • Determination of Minimum Inhibitory Concentrations (MICs) for various antipseudomonas agents.

Main Results:

  • P. aeruginosa SCVs were isolated from 33 out of 86 CF patients.
  • SCVs showed 2- to 8-fold higher MICs for antipseudomonas agents compared to revertants.
  • SCV recovery correlated with indicators of poor lung function and specific inhaled antibiotic use (tobramycin, colistin).

Conclusions:

  • P. aeruginosa SCVs are present in a significant proportion of CF patients.
  • SCVs are associated with worse clinical outcomes and specific inhaled antibiotic therapies.
  • The increased antimicrobial resistance of SCVs may impact treatment strategies for CF lung infections.

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