In Vitro Effect of Local Anesthetics on Candida albicans Germ Tube Formation

OBJECTIVE This study was planned to clarify the in vitro effect of lidocaine and bupivacaine on germ tube formation by Candida albicans isolates from cases of clinical vaginal candidiasis. METHODS Fourteen C. albicans strains (clinical vaginal isolates) were grown on Sabouraud agar for 24 h at 37 and tested as follows: 100 microl of a yeast suspension [10(5) colony forming units (CFU)/ml of phosphate buffered saline (PBS)] was added to 500 microl of fresh human serum with lidocaine or bupivacaine (pure salts) in serial concentrations. The test was run in duplicate. Controls were prepared for each strain. After 4 h of incubation at 37, samples were taken from each vial and 200 yeasts were counted in a counting chamber. The pH of each suspension was measured. RESULTS The results are given as the mean of the 2 readings and are expressed as the percentage of blastoconidia with germ tubes/total blastoconidia. CONCLUSIONS Our experiments show that both lidocaine and bupivacaine have a dose-dependent inhibitory effect, pH-independent, on germ tube formation by C. albicans and that both drugs seem to be promising in the treatment of genital candidiasis due to the combination of anesthetic and antifungal properties.