Clinical and Laboratory Standards Institute (CLSI) conditions for testing the susceptibilities of pathogenic species to antifungal agents are based on a collaborative study that evaluated five clinically relevant isolates of and some antifungal agents. With the advent of molecular identification, there are two basic needs: to confirm the suitability of these testing conditions for all agents and species and to establish species-specific epidemiologic cutoff values (ECVs) or breakpoints (BPs) for the species. We collected available CLSI MICs/minimal effective concentrations (MECs) of amphotericin B, five triazoles, terbinafine, flucytosine, and caspofungin for 301, 486 , 75, and 13 molecularly identified isolates. Data were obtained in 17 independent laboratories (Australia, Europe, India, South Africa, and South and North America) using conidial inoculum suspensions and 48 to 72 h of incubation at 35°C. Sufficient and suitable data (modal MICs within 2-fold concentrations) allowed the proposal of the following ECVs for and , respectively: amphotericin B, 4 and 4 μg/ml; itraconazole, 2 and 2 μg/ml; posaconazole, 2 and 2 μg/ml; and voriconazole, 64 and 32 μg/ml. Ketoconazole and terbinafine ECVs for were 2 and 0.12 μg/ml, respectively. Insufficient or unsuitable data precluded the calculation of ketoconazole and terbinafine (or any other antifungal agent) ECVs for , as well as ECVs for and These ECVs could aid the clinician in identifying potentially resistant isolates (non-wild type) less likely to respond to therapy.

The recent emergence of a multidrug-resistant yeast, Candida auris, has drawn attention to the closely related species from the Candida haemulonii complex that include C. haemulonii, Candida duobushaemulonii, Candida pseudohaemulonii, and the recently identified Candida vulturna. Here, we used antifungal susceptibility testing and whole-genome sequencing (WGS) to investigate drug resistance and genetic diversity among isolates of C. haemulonii complex from different geographic areas in order to assess population structure and the extent of clonality among strains. Although most isolates of all four species were genetically distinct, we detected evidence of the in-hospital transmission of C. haemulonii and C. duobushaemulonii in one hospital in Panama, indicating that these species are also capable of causing outbreaks in healthcare settings. We also detected evidence of the rising azole resistance among isolates of C. haemulonii and C. duobushaemulonii in Colombia, Panama, and Venezuela linked to substitutions in ERG11 gene as well as amplification of this gene in C. haemulonii in isolates in Colombia suggesting the presence of evolutionary pressure for developing azole resistance in this region. Our results demonstrate that these species need to be monitored as possible causes of outbreaks of invasive infection.

The aim of this study was to determine in vitro susceptibility profiles of Venezuelan strains of Candida spp. to four antifungal agents. One hundred and forty five (145) isolates were recovered during a 1-year period (June 2006 to June 2007) from clinical specimens of patients with severe Candida spp. infections in 15 hospitals. In vitro susceptibilities to amphotericin B, fluconazole, itraconazole and voriconazole were determined by modified Etest. Non Candida albicans Candida spp. were the most frequently isolated yeasts (72.4%) in comparison with C. albicans (27.6%). Candida spp. strains showed MIC ranges between <0.002 and 0.5 mug/ml to amphotericin B. While none were found to be resistant to voriconazole, 5.5% and 27.6% of the test strains were resistant to fluconazole and itraconazole, respectively. C. albicans remains the most susceptible of the yeasts studied to fluconazole and itraconazole (P<0.05) when compared with non C. albicans Candida spp. C. krusei showed the greater cross-resistance to azoles, followed by C. glabrata, C. tropicalis and C. parapsilosis, while C. albicans isolates did not demonstrate this characteristic. It is very important to carry out the correct species identification of clinical yeast isolates because they show up variations in both distribution and susceptibility profiles according to the hospital, patient's underlying disease, clinical specimen analyzed, and the geographical region in which the studies were conducted. The Mycology Department of the INHRR is the national reference center responsible for antifungal resistance surveillance, performing the susceptibility tests with isolates recovered from hospitalized patients in public health centres which do not have mycological diagnosis laboratories.

The in vitro susceptibility of 62 isolates of Sporothrix schenckii in its mycelial form, from LatinAmerican countries (Peru, Venezuela, Brazil and Uruguay) and Spain, to amphotericin B (AB), itraconazole (IZ), posaconazole (PZ) and terbinafine (TB) was determined by measuring the MICs and minimum fungicidal concentrations (MFCs) using a standardized Clinical and Laboratory Standards Institute method. In general, TB was the most active drug, with the lowest geometric mean (GM) MIC and MFC values amongst isolates from the five countries tested. IZ and PZ showed almost the same activity against all strains tested, except for isolates from Uruguay where IZ gave the highest GM MIC (10.68 mg l ). MFCs were 5 to 20 times higher than the MICs, but the lowest GM MFC and range values were found for TB. IZ and PZ gave the highest GM MFC. MFC may be a better predictor of therapeutic response than MIC, especially in immunosuppressed patients, making the use of IZ and PZ an inappropriate treatment. There were some differences in susceptibility according to the geographical source of the isolates, with the MIC being lower for TB in Venezuelan strains (P50.066) and the MFC higher for PZ in Peruvian strains (P50.02). Thus, geographical origin may be important for appropriate treatment, and may relate to the identification of species of the S. schenckii complex.

Cryptococcus neoformans is one of the medically important yeast-like fungi. C. neoformans var. gatti has been made a species: C. gatti. In our country, there are few studies about these two species and their serotypes. The aim of this study was to determine the distribution of C. neoformans and C. gattii, and their serotypes in Venezuelan clinical isolates. One hundred and twenty C. neoformans and 12 C. gattii clinical isolates were identified by L-canavanine, glycine, and bromothymol blue agar media (CGB). These were investigated by agglutination and adsorption studies with anticryptococcal sera, which were produced by rabbit immunization. Of the 132 isolates 59.8% were typed serotype A (C. neoformans), followed by 25.8% serotype D (C. neoformans), 5.3% serotype AD (C. neoformans), and 5.3% were typed serotype C (var. gattii). Additionally 3.8% were serotype B (C. gattii).

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Cryptococcosis is a sub-acute or chronic mycosis caused by opportunistic yeasts of the Cryptococcus genus, mainly by the C. neoformans and C.gattii species complex. This disease tends to position itself as one of the first opportunistic conditions associated with AIDS, with a high morbidity in these patients, who frequently develop meningoencephalitis. To date, there are techniques that allow the identification of the eight molecular types associated with these species complex, but there is little information about their circulation in Venezuela. The purpose of this work was to perform the molecular characterization of the C. neoformans and C.gattii species complex by PCR-RFLP. A total of 80 strains were used, 65 of the C. neoformans complex (CNC) and 15 of the C. gattii complex (CGC), following the protocol described by Escandon et al., carrying out the amplification of the URA5 gene and subsequent digestion with the Sau96I and HhaI restriction enzymes, that generated band patterns that allowed the identification of different molecular types. The most prevalent molecular type was VNI with 68.75% (n=55), similar to that reported worldwide;secondly, VGII molecular type with con 15% (n=12), which corresponds to that reported for Latin America, followed by VNII with 11.25% (n=9), VGIII with 2.5% (n=2), VNIII with 1.25% (n=1) and VGI with 1.25% (n=1)). Ninety-two point three percent of CCN (n=60) and 66.7% (n=10) of GCC isolates were from patients with HIV/AIDS. This study provided important epidemiological information on circulating molecular types and allowed to deepen the knowledge of this opportunistic mycosis in Venezuela.

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