We have tested 508 strains belonging to 24 species of dermatophytes against 10 antifungal drugs following mainly the NCCLS (M38-P) standard for filamentous fungi. However, several important factors, such as the temperature (28 versus 35°C) and time of incubation (4 to 10 days versus 21 to 74 h), have been modified. The antifungals used were itraconazole, ketoconazole, miconazole, clotrimazole, voriconazole, terbinafine, amphotericin B, fluconazole, UR-9825, and G-1. In general, with the exception of fluconazole and G-1, all antifungals were shown to be highly effective.Dermatophytes are a specialized group of fungi which affect keratinous tissue of humans and of other vertebrates, causing superficial infections. In recent years the number of infections caused by these fungi has increased considerably (7, 15), causing particular concern when they infect immunocompromised patients where atypical manifestations and more severe, extensive lesions can be produced (1,14). Dermatophytoses generally respond well to topical antifungal therapy, although local therapy may be inappropriate for extensive infections or for infections affecting the nails or scalp. In recent years, a number of safe and highly effective antifungal agents have been introduced into clinical practice. Among them, terbinafine (TF), itraconazole (ITZ), fluconazole (FCZ), and more recently, voriconazole (VCZ) and the new triazole UR-9825, still under clinical investigation, are probably the most promising. However, their activity against significant number of strains, representing a wide spectrum of dermatophyte species and following standard procedures, has not yet been investigated. Consequently, the aim of this study has been to evaluate the in vitro activity of the traditionally available antifungal drugs and of some of the newer ones against a significant number of strains of dermatophytes by following mainly the NCCLS guidelines for testing filamentous fungi (11). MATERIALS AND METHODS Strains.A total of 508 strains of dermatophytes belonging to 24 species were tested. They were Epidermophyton floccosum (n ϭ 22), Microsporum audouinii (n ϭ 8), Microsporum canis (n ϭ 105), Microsporum cookei (n ϭ 1), Microsporum ferrugineum (n ϭ 4), Microsporum fulvum (n ϭ 1), Microsporum gallinae (n ϭ 1), Microsporum gypseum (n ϭ 32), Microsporum nanum (n ϭ 1), Microsporum praecox (n ϭ 1), Microsporum racemosum (n ϭ 1), Trichophyton ajelloi (n ϭ 2), Trichophyton balcaneum (n ϭ 2), Trichophyton concentricum (n ϭ 2), Trichophyton erinacei (n ϭ 7), Trichophyton interdigitale (n ϭ 21), Trichophyton mentagrophytes (n ϭ 122), Trichophyton phaseoliforme (n ϭ 1), Trichophyton rubrum (n ϭ 144), Trichophyton schoenleinii (n ϭ 2), Trichophyton simii (n ϭ 2), Trichophyton tonsurans (n ϭ 18), Trichophyton verrucosum (n ϭ 1), and Trichophyton violaceum (n ϭ 7). The majority of strains were clinical isolates from different hospitals in Spain and the United Kingdom, and numerous reference strains from the Centraalbureau voor Schimmelcultures were also tested. The fungi were mai...
The colorimetric method appears to be a suitable alternative procedure for antifungal susceptibility testing of Aspergillus spp. and is able to detect resistance to itraconazole. The range of MICs for amphotericin B by Etest is wider and for some strains is >16 mg/L, suggesting that this method could be useful for detecting resistant strains as occur in yeasts.
The susceptibilities of 63 isolates of Aspergillus spp. to voriconazole were evaluated by a modified NCCLS M38-A method and the Sensititre YeastOne method. The overall agreement was 82.5%, ranging from 100% for Aspergillus niger and Aspergillus terreus to 62.5% for Aspergillus flavus. Discrepancies between the methods were due to higher Sensititre MICs. The Sensititre YeastOne method could have potential value for susceptibility testing of Aspergillus spp. to voriconazole.Over the past decades, the incidence of invasive fungal infections has increased, especially those caused by Aspergillus species (18). The treatment of choice for infected patients remains amphotericin B, although alternative drugs with activities against Aspergillus species are becoming available for clinical use, including antifungal azoles and echinocandins (6,18). Because the number of serious infections caused by Aspergillus spp. has increased, as has the resistance of Aspergillus spp. to established agents, determination of the in vitro susceptibilities of Aspergillus isolates to both established and investigational agents is necessary (6).There is a great need for an easier and reproducible method for in vitro susceptibility testing of filamentous fungi as a guide to selecting and monitoring antifungal therapy. Alternatives to the NCCLS method are currently under investigation, including two commercial methods, E-test and Sensititre YeastOne, which have been evaluated for yeast and molds (1,3,5,6,9,10,11,(13)(14)(15)(16)(17).Our study represents an evaluation of the suitability of Sensititre YeastOne for determining the susceptibilities of Aspergillus spp. isolates to voriconazole. This test is a commercial colorimetric panel that consists of a disposable tray which contains dried serial dilutions of five antifungal agents in individual wells. The wells also contain an oxidation-reduction indicator (Alamar Blue) to generate clear-cut endpoints based on a visually detectable color change. MICs obtained by this method were compared to those obtained by the modified reference broth microdilution method (14).A total of 63 clinical Aspergillus isolates, comprising 24 Aspergillus fumigatus isolates, 16 Aspergillus flavus isolates, 9 Aspergillus terreus isolates, 8 Aspergillus niger isolates, 4 Aspergillus glaucus isolates, and 2 Aspergillus nidulans isolates, were included in this study. These isolates were recovered from clinical specimens of patients at the Valme University Hospital, Seville, Spain, and the Division of Infectious Diseases, Medical College of Virginia, Virginia Commonwealth University, Richmond.Culture, identification, and preservation of strains were done by using routine mycological methods (4, 7). Candida krusei ATCC 6258 and Candida parapsilosis ATCC 22019 were used as quality control strains for susceptibility testing procedures, and Aspergillus fumigatus ATCC 204305 and Aspergillus flavus ATCC 204304 were used as reference strains.The broth microdilution method was performed according to modified NCCLS standard M38-A gu...
BackgroundIn Spain, the influenza vaccine effectiveness (VE) was estimated in the last three seasons using the observational study cycEVA conducted in the frame of the existing Spanish Influenza Sentinel Surveillance System. The objective of the study was to estimate influenza vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza-like illness (ILI) among the target groups for vaccination in Spain in the 2011–2012 season. We also studied influenza VE in the early (weeks 52/2011-7/2012) and late (weeks 8-14/2012) phases of the epidemic and according to time since vaccination.MethodsMedically attended patients with ILI were systematically swabbed to collect information on exposure, laboratory outcome and confounding factors. Patients belonging to target groups for vaccination and who were swabbed <8 days after symptom onset were included. Cases tested positive for influenza and controls tested negative for any influenza virus. To examine the effect of a late season, analyses were performed according to the phase of the season and according to the time between vaccination and symptoms onset.ResultsThe overall adjusted influenza VE against A(H3N2) was 45% (95% CI, 0–69). The estimated influenza VE was 52% (95% CI, -3 to 78), 40% (95% CI, -40 to 74) and 22% (95% CI, -135 to 74) at 3.5 months, 3.5-4 months, and >4 months, respectively, since vaccination. A decrease in VE with time since vaccination was only observed in individuals aged ≥ 65 years. Regarding the phase of the season, decreasing point estimates were only observed in the early phase, whereas very low or null estimates were obtained in the late phase for the shortest time interval.ConclusionsThe 2011–2012 influenza vaccine showed a low-to-moderate protective effect against medically attended, laboratory-confirmed influenza in the target groups for vaccination, in a late season and with a limited match between the vaccine and circulating strains. The suggested decrease in influenza VE with time since vaccination was mostly observed in the elderly population. The decreasing protective effect of the vaccine in the late part of the season could be related to waning vaccine protection because no viral changes were identified throughout the season.
On the basis of our results, it appears that the disc diffusion test is a useful method for testing the activity of voriconazole against Aspergillus spp.
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