First Clinical Isolation of an Azole-Resistant Aspergillus fumigatus Isolate Harboring a TR46 Y121F T289A Mutation in South America.

One of the most recently described Aspergillus fumigatusCYP51A-mediated azole resistance mechanisms is TR46 Y121F T289A. Clinical A. fumigatus strains harboring these substitutions have been reported worldwide, with the exception of South America. We describe the first clinical A. fumigatus strain with this resistance mechanism isolated from an Argentinian patient. The strain was isolated in 2009 (1 year after the first-described mutant in United States), demonstrating that these alleles were scattered worldwide earlier than previously thought.

Phenotypic and Molecular Evaluation of Echinocandin Susceptibility of Candida glabrata, Candida bracarensis, and Candida nivariensis Strains Isolated during 30 Years in Argentina.

The echinocandin susceptibilities of 122 Candida glabrata complex strains (including 5 Candida nivariensis and 3 Candida bracarensis strains) were evaluated by microdilution and compared with the results from a molecular tool able to detect FKS mutations. No echinocandin resistance was detected. The PCR results coincide with the MIC data in 99.25% of the cases (1 C. glabrata strain was misidentified as resistant) but were 20 h faster. C. nivariensis FKS genes were sequenced and showed differences with C. glabrataFKS genes.

kMucormicosys due to Saksenaea vasiformis in a dog.

A 2-year-old female Border collie was examined for dermatitis with a partial alopecic zone around her left front member. Six months later the lesion became swollen, alopecic with ulcerated areas. Microscopy analysis of samples showed numerous non-septate, branching, thin-walled and irregular shaped hyphal elements. Fungal cultures and molecular studies identified Saksenaea vasiformis. Treatments with griseofulvin, itraconazole and surgical debridement were used, however, fourteen months later the dog was euthanatized because of the unfavorable clinical outcome.

Antifungal susceptibility testing of Malassezia yeast: comparison of two different methodologies.

All Malassezia species are lipophilic; thus, modifications are required in susceptibility testing methods to ensure their growth. Antifungal susceptibility of Malassezia species using agar and broth dilution methods has been studied. Currently, few tests using disc diffusion methods are being performed. The aim was to evaluate the in vitro susceptibility of Malassezia yeast against antifungal agents using broth microdilution and disc diffusion methods, then to compare both methodologies. Fifty Malassezia isolates were studied. Microdilution method was performed as described in reference document and agar diffusion test was performed using antifungal tablets and discs. To support growth, culture media were supplemented. To correlate methods, linear regression analysis and categorical agreement was determined. The strongest linear association was observed for fluconazole and miconazole. The highest agreement between both methods was observed for itraconazole and voriconazole and the lowest for amphotericin B and fluconazole. Although modifications made to disc diffusion method allowed to obtain susceptibility data for Malassezia yeast, variables cannot be associated through a linear correlation model, indicating that inhibition zone values cannot predict MIC value. According to the results, disc diffusion assay may not represent an alternative to determine antifungal susceptibility of Malassezia yeast.

Candida glabrata species complex prevalence and antifungal susceptibility testing in a culture collection: First description of Candida nivariensis in Argentina.

The presence of the cryptic species belonging to the Candida glabrata complex has not been studied in Argentina. We analyzed a collection of 117 clinical isolates of C. glabrata complex belonging to a National Culture Collection of Instituto Nacional de Microbiología "Dr. Carlos G. Malbrán" from Argentina (40 isolates from blood samples, 18 from other normally sterile sites, 20 from vagina, 14 from urine, 7 from oral cavity, 3 from catheter, 1 from a stool sample and 14 isolates whose clinical origin was not recorded). The aims of this work were to determine the prevalence of the cryptic species Candida nivariensis and Candida bracarensis and to evaluate the susceptibility profile of isolates against nine antifungal drugs. Identification was carried out by using classical phenotypic tests, CHROMagar™ Candida, PCR and MALDI-TOF. The minimal inhibitory concentrations of amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, voriconazole, ketoconazole, posaconazole, caspofungin and anidulafungin were determined according to the EDef 7.3 (EUCAST) reference document. Of the 117 isolates, 114 were identified as C. glabrata and three as C. nivariensis by using PCR and MALDI-TOF. There were no major differences between C. nivariensis and C. glabrata susceptibility profiles. No resistant strains were found to echinocandins. We have found that the percentage of C. nivariensis in our culture collection was 2.56. This is the first description of C. nivariensis in Argentina, and data obtained could contribute to the knowledge of the epidemiology of this cryptic species.

Epidemiología de la candidemia y sensibilidad in vitro frente a azoles, anfotericina B y caspofungina en una institución de salud de Valledupar, Colombia / Epidemiology of candidemia and in vitro susceptibility to azoles, amphotericin B and caspofungin in a health institution of Valledupar, Colombia

Introducción: la candidemia es una enfermedad grave, con elevada morbi-mortalidad y cuyo tratamientono siempre conduce a la cura. La distribución de especies de Candida y la sensibilidad antifúngica varía según el área geográfica, incluso entre centros de salud de una misma región. Objetivo:establecer la distribución de especies de Candida y su sensibilidad in vitro frente a diferentes antifúngicos. Materiales y métodos: se realizó un estudio descriptivo, prospectivo y transversal entre noviembre de 2013 y mayo de 2014 de casos de candidemias en una institución de salud de Valledupar,Colombia. Las Concentraciones Inhibitorias Mínimas (CIM) se determinaron según el protocolo estándar M27-A3-S4. Resultados: Se estudiaron 40 aislados clínicos de Candida spp. obtenidos de sangre (97,5%) y médula ósea (2,5%). Del total, 15 (37,5%) fueron caracterizados como Candida tropicalis, 13 (32,5%) del Complejo Candida albicans, cinco (12,5%) del Complejo Candida glabrata, tres (7,5%) como Candida guilliermondii, tres (7,5%) del Complejo Candida parapsilosis y uno (2,5%) como Candida krusei. No se observó resistencia a la anfotericina B ni al voriconazol en ninguno de los aislados, pero sí al fluconazol en uno (6,6%) de Candida tropicalis y uno (33,3%) del Complejo Candida parapsilosis y a la caspofungina en el aislado de Candida krusei y en uno (20%) del Complejo Candida glabrata...

Introduction: candidemia is a serious disease with high morbidity and mortality whose treatment does not always lead to a cure. Candida species distribution and antifungal susceptibility varies by geographic area, even in health centers in a given region. Objective: To establish Candida species distributionand in vitro susceptibility to different antifungal agents. Material and methods: A descriptive, prospective, and cross-sectional study of candidemia cases was performed at a health institution in Valledupar, Colombia between November 2013 and May 2014. The Minimum Inhibitory Concentrations(MIC) were determined following the M27-A3-S4 standard protocol. Results: 40 isolates of Candida spp. obtained from blood (97.5%) and bone marrow (2.5%) were analyzed. Candida tropicalis, 15 (37.5%), Candida albicans Complex, 13 (32.5%), Candida glabrata Complex, five (12.5%), Candida guilliermondii, three (7.5%), Candida parapsilosis Complex 3 (7.5%) and Candida krusei, one (2.5%) were isolated. No resistance of isolates to amphotericin B and voriconazole was observed; in contrast, one (6.6%) isolate of Candida tropicalis and one (33.3%) of Candida parapsilosisComplex showed resistance to fluconazole and a single isolate of Candida krusei and one (20%) of Candida glabrata Complex to caspofungin...

Antifungal susceptibility of Malassezia furfur, Malassezia sympodialis, and Malassezia globosa to azole drugs and amphotericin B evaluated using a broth microdilution method.

We studied the in vitro activity of fluconazole (FCZ), ketoconazole (KTZ), miconazole (MCZ), voriconazole (VCZ), itraconazole (ITZ) and amphotericin B (AMB) against the three major pathogenic Malassezia species, M. globosa, M. sympodialis, and M. furfur. Antifungal susceptibilities were determined using the broth microdilution method in accordance with Clinical and Laboratory Standards Institute reference document M27-A3. To support lipid-dependent yeast development, glucose, peptone, ox bile, malt extract, glycerol, and Tween supplements were added to Roswell Park Memorial Institute RPMI 1640 medium. The supplemented medium allowed good growth of all three species studied. The minimal inhibitory concentrations (MICs) were recorded after 72 h of incubation at 32ºC. The three species showed different susceptibility profiles for the drugs tested. Malassezia sympodialis was the most susceptible and M. furfur the least susceptible species. KTZ, ITZ, and VCZ were the most active drugs, showing low variability among isolates of the same species. FCZ, MCZ, and AMB showed high MICs and wide MIC ranges. Differences observed emphasize the need to accurately identify and evaluate antifungal susceptibility of Malassezia species. Further investigations and collaborative studies are essential for correlating in vitro results with clinical outcomes since the existing limited data do not allow definitive conclusions.