Pseudomonas aeruginosa pyocyanin and 1-hydroxyphenazine inhibit fungal growth.
OBJECTIVE
To examine strains of Pseudomonas aeruginosa for specific antifungal factors.


METHODS
Two clinical strains of P aeruginosa with strong in vitro inhibition (by cross streak assay) of Candida albicans and Aspergillus fumigatus were examined. Both strains were isolated from sputum--one from a patient with cystic fibrosis and one from a patient with bronchiectasis. Bacterial extracts were fractionated by high performance liquid chromatography and examined by ultraviolet absorbance and mass spectroscopy. Antifungal activity against C albicans and A fumigatus was determined in a well plate assay.


RESULTS
Pyocyanin was the major antifungal agent of P aeruginosa; 1-hydroxy-phenazine also possessed activity. Pyocyanin MICs for C albicans and A fumigatus were > 64 micrograms/ml. These phenazines were active against nine other yeast species pathogenic for man. Preliminary experiments also suggested possible inhibition of yeast mycelial transformation in C albicans by pyocyanin.


CONCLUSIONS
There may be a role for pyocyanin and 1-hydroxyphenazine in the prevention of pulmonary candidiasis in patients colonised by P aeruginosa.
Kerr
J R
JR
Host Defence Unit, National Heart and Lung Institute, Imperial College, School of Medicine, London, UK.
Taylor
G W
GW
Rutman
A
A
Høiby
N
N
Cole
P J
PJ
Wilson
R
R
D001232:Aspergillus fumigatus / Q000187:drug effects*; D001987:Bronchiectasis / Q000382:microbiology; D002176:Candida albicans / Q000187:drug effects* / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D003550:Cystic Fibrosis / Q000382:microbiology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000378:metabolism*; D011710:Pyocyanine / Q000096:biosynthesis / Q000302:isolation & purification / Q000494:pharmacology*; D013183:Sputum / Q000382:microbiology*
D011710:Pyocyanine