In-vitro activity of polyhexamethylene biguanide (PHMB) against fungal isolates associated with infective keratitis

Extract

J Antimicrob Chemother 1999; 44: 297–298

Sir,

Fungal keratitis is an infection that is difficult both to diagnose and to treat. Candida albicans, other yeasts and the septate moulds, Fusariumspp. and Aspergillus spp., are common causes of this disease. Treatment options are limited and include topical formulations of natamycin (5%), amphotericin B (0.15%) and fluconazole (1%). However, the efficacies of these agents are compromised by poor ocular penetration, poor tolerability and/or poor in-vitro activity. ¹ Polyhexamethylene biguanide (PHMB), which is currently used as an environmental biocide and contact lens disinfectant, has been shown to have excellent in-vitro activity against a broad range of fungal pathogens ² and to be effective and well tolerated at concentrations of 200 mg/L (0.02%) when used as treatment of patients with keratitis caused by Acanthamoeba spp. ³ The present study was undertaken to evaluate the in-vitro activity of PHMB against fungal isolates associated with infective keratitis.