Comparative Evaluation of Disc Diffusion and E-test with Broth Micro-dilution in Susceptibility testing of Amphotericin B, Voriconazole and Caspofungin against Clinical Aspergillus isolates

Fungal infections especially by filamentous fungi are on rise due to increase in the risk factors like use of drugs to suppress immune system causing neutropenia (steroids, anticancer chemotherapy, and anti-rejection drugs) and disorders like AIDS, diabetes, immunological diseases, COPD etc.The incidence of invasive aspergillosis is highly variable depending on the patient population. In solid organ transplant the incidence of invasive aspergillosis may be up to 3.5% depending on the type of transplant recipients [1]. XessI et al., from New Delhi, India had reported an incidence of 2.43 % for Aspergillosis [2]. Among Aspergillus spp., A.fumigatus is responsible for majority of infections, although other molds have also emerged as an important aetiological agent causing invasive fungal infections [3]. Amphotericin B is the most common antifungal agent being used worldwide for the treatment of filamentous fungal infections. Over the last few years voriconazole and caspofungin have also been approved for its treatment. Rise in MIC values to various antifungals in A. fumigates and non-fumigatus are increasingly being reported. A study done by Shivprakash et al., in India had reported 3 strains of A. flavus with high MIC values of 2 mg/l for AMB and 4 mg/l for VCZ [4].