716. Characterization of Azole Susceptibility Profiles of Aspergillus spp. Isolates Obtained From Immunocompromised Patients in Cali, Colombia

Abstract

Abstract Background Aspergillus spp. are opportunistic filamentous fungi causing a spectrum of diseases described aspergillosis. Aspergillosis is treated with triazole antifungals of second-generation, mostly voriconazole or itraconazole, which inhibit the ergosterol synthesis, an important component of the fungal membrane. However, the efficacy of these drugs has been affected by the presence of resistance found in different Aspergillus spp. species, as a mutations in CYP51 gene We describe the azole susceptibility profiles of Aspergillus spp., isolated from clinical samples in a hospital in Cali, Colombia. Methods A total of 63 Aspergillus spp. clinical isolates were identified at a phenotypic and protein level through matrix-assisted laser ionization (MALDI-TOF-MS), susceptibility profiles against voriconazole and itraconazole were subsequently characterized. Following the guidelines for susceptibility determination issued by EUCAST, 96-well plates were prepared with the azole antifungals itraconazole (ITZ) and voriconazole(VCZ), using concentrations ranging from 0.06 to 32 mg/L. Each well was then inoculated with 100μL of the fungal inoculum previously diluted in distilled water and 20% tween adjusted to a concentration of 0.5 on the Mcfarland scale. The plates were incubated at 37 °C and readings were taken after 48 hours of incubation. Results A total of 63 clinical isolates of Aspergillus spp were collected, of these 44% corresponded to isolates of A. fumigatus, 25% A. flavus/oryzae, 18% A. niger, 5% A. parasiticus, 3% A. terreus and 3% A. versicolor. In vitro characterization of the susceptibility profiles revealed variable phenotypes, with a predominance of susceptible strains for the two antifungals tested, however, of the total isolates, 8% (5/63) were resistant to itraconazole (ITZ), and 6% (4/63) to voriconazole (VRZ). Figure 1. Distribution or Frequency of Aspergillus spp. Species and Their Resistance Profiles Conclusion Azole resistance was low 6-8% . Susceptibility profiles of the strains isolated from clinical samples is important to carry out an accurate identification of each one of the agents involved in infections caused by Aspergillus spp in order to differentiate common species from cryptic ones, since these have increasingly acquired importance at the clinical level,. Disclosures All Authors: No reported disclosures