Evaluation of antifungal combination against Cryptococcus spp

The second cause of death among systemic mycoses, cryptococcosis treatment represents a challenge since that 5-flucytosine is not currently available in Brazil. Looking for alternatives, this study evaluated antifungal agents, alone and combined, correlating susceptibility to genotypes. Eighty Cryptococcus clinical isolates were genotyped by URA5 gene restriction fragment length polymorphism. Antifungal susceptibility was assessed following CLSI-M27A3 for amphotericin (AMB), 5-flucytosine (5FC), fluconazole (FCZ), voriconazole (VRZ), itraconazole (ITZ) and terbinafine (TRB). Drug interaction chequerboard assay evaluated: AMB + 5FC, AMB + FCZ, AMB + TRB and FCZ + TRB. Molecular typing divided isolates into 14 C. deuterogattii (VGII) and C. neoformans isolates were found to belong to genotype VNI (n = 62) and VNII (n = 4). C. neoformans VNII was significantly less susceptible than VNI (P = 0.0407) to AMB; C. deuterogattii was significantly less susceptible than VNI and VNII to VRZ (P < 0.0001). C. deuterogattii was less susceptible than C. neoformans VNI for FCZ (P = 0.0170), ITZ (P < 0.0001) and TRB (P = 0.0090). The combination FCZ + TRB showed 95.16% of synergistic effect against C. neoformans genotype VNI isolates and all combinations showed 100% of synergism against genotype VNII isolates, suggesting the relevance of cryptococcal genotyping as it is widely known that the various genotypes (now species) have significant impact in antifungal susceptibilities and clinical outcome. In difficult-to-treat cryptococcosis, terbinafine and different antifungal combinations might be alternatives to 5FC599585593JICA (Japan International Cooperation Agency); SATREPS (Science and Technology Research Partnership for Sustainable Development

MIC range (μg/mL) of LIF 12560 and LIF-E10 against amphotericin B, 5-flucytosine, fluconazole, itraconazole and voriconazole.

<p>MIC range (μg/mL) of LIF 12560 and LIF-E10 against amphotericin B, 5-flucytosine, fluconazole, itraconazole and voriconazole.</p

MICs Distribution (μg/mL) of 143 <i>Candida albicans</i> bloodstream isolates against amphotericin B, 5-flucytosine, fluconazole, itraconazole, voriconazole and caspofungin.

<p>MICs Distribution (μg/mL) of 143 <i>Candida albicans</i> bloodstream isolates against amphotericin B, 5-flucytosine, fluconazole, itraconazole, voriconazole and caspofungin.</p

Resistance Surveillance in <i>Candida albicans</i>: A Five-Year Antifungal Susceptibility Evaluation in a Brazilian University Hospital

<div><p><i>Candida albicans</i> caused 44% of the overall candidemia episodes from 2006 to 2010 in our university tertiary care hospital. As different antifungal agents are used in therapy and also immunocompromised patients receive fluconazole prophylaxis in our institution, this study aimed to perform an antifungal susceptibility surveillance with the <i>C</i>.<i>albicans</i> bloodstream isolates and to characterize the fluconazole resistance in 2 non-blood <i>C</i>.<i>albicans</i> isolates by sequencing <i>ERG11</i> gene. The study included 147 <i>C</i>. <i>albicans</i> bloodstream samples and 2 fluconazole resistant isolates: one from oral cavity (LIF 12560 fluconazole MIC: 8μg/mL) and one from esophageal cavity (LIF-E10 fluconazole MIC: 64μg/mL) of two different patients previously treated with oral fluconazole. The <i>in vitro</i> antifungal susceptibility to amphotericin B (AMB), 5-flucytosine (5FC), fluconazole (FLC), itraconazole (ITC), voriconazole (VRC), caspofungin (CASP) was performed by broth microdilution methodology recommended by the Clinical and Laboratory Standards Institute documents (M27-A3 and M27-S4, CLSI). All blood isolates were classified as susceptible according to CLSI guidelines for all evaluated antifungal agents (MIC range: 0,125–1.00 μg/mL for AMB, ≤0.125–1.00 μg/mL for 5FC, ≤0.125–0.5 μg/mL for FLC, ≤0.015–0.125 μg/mL for ITC, ≤0.015–0.06 μg/mL for VRC and ≤0.015–0.125 μg/mL for CASP). In this study, we also amplified and sequenced the <i>ERG11</i> gene of LIF 12560 and LIF-E10 <i>C</i>.<i>albicans</i> isolates. Six mutations encoding distinct amino acid substitutions were found (E116D, T128K, E266D, A298V, G448V and G464S) and these mutations were previously described as associated with fluconazole resistance. Despite the large consumption of antifungals in our institution, resistant blood isolates were not found over the trial period. Further studies should be conducted, but it may be that the very prolonged direct contact with the oral antifungal agent administered to the patient from which was isolated LIF E-10, may have contributed to the development of resistance.</p></div

Nucleotide mutations and amino acid substitutions.

<p>Nucleotide mutations and amino acid substitutions.</p