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Selective medium for Pseudomonas cepacia containing 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan and polymyxin
Abstract:
Contamination of solutions and lotions with Pseudomonas cepacia is a growing concern among health professionals. The identification of P. cepacia usually requires a long series of biochemical tests. In an effort to develop a more direct method, we evaluated plate count agar containing 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan and polymyxin B sulfate at respective concentrations of 1 and 75 micrograms/ml as a medium for selectively isolating P. cepacia. The medium inhibited the growth of all gram-negative bacilli and gram-positive cocci tested except P. cepacia and Serratia marcescens. These two microorganisms could easily be differentiated by their colony morphology and their reactions in the oxidase test. When nonsterilized water samples were inoculated with P. cepacia and spread or streaked on the selective medium, all P. cepacia organisms were recovered. These results demonstrate the usefulness of 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan and polymyxin B sulfate in the detection of P. cepacia. We believe that this selective medium could be useful in isolating P. cepacia from mixed bacterial flora that might be present in environmental water and water-related samples, such as solutions and lotions.
Insights
A new selective medium effectively isolates Pseudomonas cepacia from contaminated solutions and lotions. This method simplifies detection, aiding healthcare professionals in identifying this growing bacterial concern.
Area of Science:
- Microbiology
- Clinical Diagnostics
- Bacterial Pathogenesis
Background:
- Pseudomonas cepacia contamination poses a significant risk in healthcare settings.
- Current identification methods for P. cepacia are time-consuming and complex.
- Development of rapid and selective isolation techniques is crucial.
Purpose of the Study:
- To evaluate a novel selective agar medium for the direct isolation of Pseudomonas cepacia.
- To assess the efficacy of specific antimicrobial agents in inhibiting non-target organisms.
Main Methods:
- Plate count agar supplemented with 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan and polymyxin B sulfate was utilized.
- The medium's inhibitory effects on various bacterial species were tested.
- Recovery rates of P. cepacia from spiked environmental water samples were determined.
Main Results:
- The selective medium successfully inhibited Gram-negative bacilli and Gram-positive cocci, excluding P. cepacia and Serratia marcescens.
- P. cepacia and S. marcescens were readily distinguishable by colony morphology and oxidase test results.
- 100% recovery of P. cepacia from inoculated non-sterilized water samples was achieved.
Conclusions:
- The developed selective medium containing 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan and polymyxin B sulfate is effective for P. cepacia detection.
- This medium offers a valuable tool for isolating P. cepacia from diverse environmental and product samples.
- The simplified detection method can aid healthcare professionals in managing P. cepacia contamination concerns.