Effect of Simultaneous Treatment of Quinolones and Antifungal Drugs on Fungal-Bacterial Coculture

Abstract

Purpose: : The most common complications of keratomycosis is superinfection, patients are often treated concomitantly with quinolones and antifungal drugs.¹ In a retrospective study conducted at Institute of Ophthalmology of Mexico City, in samples of patients with keratitis or corneal ulcer, was found that Gram-positive bacterial infections are 20% higher risk of infection by fungus compared those Gram negative.² The aim of the present work was to evaluate in vitro, simultaneous treatment effect with quinolones and antifungal drugs in fungal-bacterial cocultures.

Methods: : Were isolated and identified strains from patients with keratitis. Cocultures were performed between Fusarium oxysporum and Aspergillus fumigatus with S. aureus or S. epidermidis in presence of gatifloxacin or moxifloxacin and amphotericin B, natamycin or itraconazole at minimal inhibitory concentrations (MIC's) determined for every microorganism studied.

Results: : The untreated cocultures showed effects of competition between fungi and bacteria. Amphotericin B inhibited the growth of both fungi. The growth of A. fumigatus was also affected by natamycin. In the simultaneous treatment of the cocultures, quinolones interfere with the effect antifungal except for treatment with itraconazole. In all cases of simultaneous treatment, was observed collaboration between bacteria in the growth of fungus.

Conclusions: : The MIC’s for quinolones used in this work interferes with the antifungal effect. Simultaneous quinolone-antifungal treatment represents stress conditions inducing inter-specie association. References. 1. Parmar P et. al. Curr Opin Infect Dis 2006;20:129-141). 2. Mejía-López, H et. al. ARVO Meeting fort Lauderdale,Florida, EUA; Abril-Mayo 2010.

Keywords: antibiotics/antifungals/antiparasitics • bacterial disease • fungal disease