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Updated: Nov 10, 2025
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A Platform of Anti-biofilm Assays Suited to the Exploration of Natural Compound Libraries
Published on: December 27, 2016
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BIOFILM FORMING ACTIVITY OF NON-FERMENTING GRAM-NEGATIVE BACTERIA
Valentyn P Kovalchuk1, Oleksandr A Nazarchuk1, Vita M Burkot1
1NATIONAL PIROGOV MEMORIAL MEDICAL UNIVERSITY, VINNYTSIA, UKRAINE.
Wiadomosci Lekarskie (Warsaw, Poland : 1960)
|April 4, 2021
Summary
Pseudomonas aeruginosa and Acinetobacter baumannii form protective biofilms under nutrient-poor, antibiotic-present, or high osmotic pressure conditions. However, high salt concentrations stimulate biofilm formation in Acinetobacter but inhibit it in Pseudomonas.
Area of Science:
- Microbiology
- Environmental Science
Background:
- Pseudomonas aeruginosa and Acinetobacter baumannii are opportunistic pathogens known for forming biofilms.
- Biofilm formation contributes to microbial persistence and resistance to environmental stressors and antimicrobial agents.
Purpose of the Study:
- To investigate the impact of various chemical and physical factors on the biofilm-forming capabilities of P. aeruginosa and A. baumannii.
- To understand the environmental conditions that promote or inhibit biofilm development in these bacterial species.
Main Methods:
- Studied biofilm formation in 10 isolates each of P. aeruginosa and A. baumannii.
- Utilized nutrient media of varying compositions.
- Employed a 96-well plate assay with crystal violet staining and spectrophotometry (620 nm) for quantification.
Main Results:
- High biofilm formation was observed in standard media for 90% of P. aeruginosa and 60% of A. baumannii isolates.
- A. baumannii formed biofilms even in sterile water.
- Urease-positive P. aeruginosa showed increased biofilm activity with 1.0% urea.
- Both species enhanced biofilm production in 5% serum or sub-bacteriostatic levofloxacin concentrations.
- High sodium chloride concentrations inhibited biofilm activity in P. aeruginosa but stimulated it in A. baumannii.
Conclusions:
- P. aeruginosa and A. baumannii exhibit adaptive biofilm formation under adverse conditions like nutrient limitation, high osmotic pressure, and antibiotic presence.
- Environmental factors differentially influence biofilm formation; high salt stimulates Acinetobacter but inhibits Pseudomonas biofilm activity.
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