Is Susceptibility Testing of Aspergillus Useful to Clinical Management?
Successful testing methodology has advanced substantially in the last 5 years. Resistance in A fumigatus has been described in the literature,[15-17] and is present in many different countries. However, the frequency of resistance to itraconazole appears to be low possibly 1% to 3%. Optimal methods for testing susceptibility to Aspergillus have yet to be agreed upon, although numerous methods do detect resistance. Most isolates resistant to itraconazole are not resistant to the new azoles. Amphotericin B resistance appears to be universal in A terreus.[18,19] Some amphotericin B-resistant isolates of A fumigatus and A flavus have been identified, as defined by extremely poor responses in animal models, but a testing methodology for use in the typical microbiology laboratory has yet to be developed. In summary, significant advances have been made in invasive aspergillosis over the last 5 years. The introduction of active new drugs such as caspofungin, variconazole, and posaconazole shou
