Comparison of Neo-Sensitabs Tablet Diffusion Assay with CLSI Broth Microdilution M38-A and Disk Diffusion Methods for Testing Susceptibility of Filamentous Fungi with Amphotericin B, Caspofungin, Itraconazole, Posaconazole, and Voriconazole

Espinel-Ingroff, Ana; Cantón, Emilia

doi:10.1128/jcm.01883-07

Cited by 36 publications

(18 citation statements)

References 19 publications

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“…We observed an excellent correlation between the in vitro results obtained with microdilution, disk diffusion, and MFC. In agreement with other authors, our in vitro results suggest that the disk diffusion method could be a good option for determining voriconazole susceptibility (23,24), due to its simplicity, low cost, and high reproducibility. Our MFC data (MFC/MIC Յ 2) confirmed the fungicidal activity of this drug against A. fumigatus (25, 26).…”

Section: Discussionsupporting

confidence: 79%

Evaluation of the In Vitro Activity of Voriconazole As Predictive of In Vivo Outcome in a Murine Aspergillus fumigatus Infection Model

Salas

Pastor

Sutton

et al. 2013

Antimicrob Agents Chemother

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bWe have evaluated the in vitro activity of voriconazole against 61 strains of Aspergillus fumigatus by using broth microdilution, disk diffusion, and minimal fungicidal concentration procedures. We observed an excellent correlation between the results obtained with the three methods. Five percent of the strains showed MICs greater than or equal to the epidemiological cutoff value (ECV; 1 g/ml). To assess whether MICs were predictive of in vivo outcome, we tested the efficacy of voriconazole at 25 mg/kg of body weight daily in an immunosuppressed murine model of disseminated infection using 10 strains representing various patterns of susceptibility to the drug as determined by the in vitro study. Voriconazole prolonged survival and reduced fungal load in the kidneys and brain in those mice infected with strains with MICs of <0.25 g/ml, while in mice infected with strains with MICs of 0.5 to 2 g/ml, the efficacy was varied and strain dependent and in mice infected with the strain with a MIC of 4 g/ml, the antifungal did not show efficacy. Voriconazole reduced galactomannan antigenemia against practically all strains with a MIC of <4 g/ml. Our results demonstrate that some relationship exists between voriconazole MICs and in vivo efficacy; however, further studies testing additional strains are needed to better ascertain which MIC values can predict clinical outcome. Invasive aspergillosis is an important cause of morbidity and mortality in the immunocompromised host, Aspergillus fumigatus being the leading cause of invasive aspergillosis worldwide (1). At present, voriconazole is the first choice in the treatment of such infections (2), and although A. fumigatus is generally susceptible to voriconazole, several studies have demonstrated an increasing number of azole-resistant isolates (3-5). This represents an important problem in the clinical management of invasive aspergillosis because therapeutic options are limited.The development of clinical breakpoints of the most usual antifungal drugs might be useful for predicting the outcomes of fungal infections. However, the available antifungal susceptibility data are only based on in vitro and animal studies (6). A recent important step has been the proposal of epidemiological cutoff values (ECVs) for voriconazole against several Aspergillus spp., including A. fumigatus (ECV ϭ 1 g/ml), and theoretically, those isolates showing MICs higher than the ECV will show resistance (7,8).We have evaluated the efficacy of voriconazole at 25 mg/kg of body weight (9) in a murine model of disseminated infection by A. fumigatus, testing isolates with different MICs in order to ascertain the role of the in vitro data as a predictor of infection outcome. MATERIALS AND METHODSSixty-one clinical strains of Aspergillus fumigatus were tested in the in vitro studies. Their susceptibility to voriconazole was evaluated using a broth microdilution method, carried out according to the CLSI guidelines for filamentous fungi (10), and a disk diffusion method that uses nonsupplemented Mueller-Hi...

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Section: Discussionsupporting

confidence: 79%

Evaluation of the In Vitro Activity of Voriconazole As Predictive of In Vivo Outcome in a Murine Aspergillus fumigatus Infection Model

Salas

Pastor

Sutton

et al. 2013

Antimicrob Agents Chemother

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“…The Neo-Sensitabs tablet diffusion method offers simple, quick and costeffective susceptibility testing for determining the inhibition zone diameter of antifungal agents and is comparable to the Clinical and Laboratory Standards Institution (CLSI) M27-A2 assay for testing for yeasts and filamentous fungi in clinical laboratories (Espinel-Ingroff & Canton, 2008). However, there is limited information regarding the NeoSensitabs method for antifungal susceptibility testing of Candida isolates in patients with VVC (Liu et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Molecular identification and antifungal susceptibility of 186 Candida isolates from vulvovaginal candidiasis in southern China

Shi

Yang

Zhang

et al. 2015

Journal of Medical Microbiology

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There is limited information regarding the molecular epidemiology and antifungal susceptibilities of Candida isolates using the Neo-Sensitabs method in patients with vulvovaginal candidiasis (VVC). From August 2012 to March 2013, 301 non-pregnant patients aged 18-50 years with suspected VVC were prospectively screened at a teaching hospital in southern China. The vaginal isolates were identified by DNA sequencing of internal transcribed spacer and the D1/D2 domain. Antifungal susceptibility testing of seven antifungal agents was performed using the NeoSensitabs tablet diffusion method. Candida species were isolated from 186 cases (61.79 %). The most common pathogen was Candida albicans (91.4 %), followed by Candida glabrata (4.3 %), Candida tropicalis (3.2 %) and Candida parapsilosis (1.1 %). The susceptibility rates to C. albicans were higher for caspofungin, voriconazole and fluconazole than those for itraconazole, miconazole, ketoconazole and terbinafine (P,0.01). The resistance rates to C. albicans were 4.7, 6.5, 7.1, 7.6, 12.3, 27.7 and 74.7 % for caspofungin, miconazole, itraconazole, voriconazole, fluconazole, ketoconazole and terbinafine, respectively. No drugs tested apart from fluconazole exhibited differences in resistance between C. albicans and non-albicans Candida isolates. The results demonstrate that, using DNA sequencing, C. albicans is the most common isolate from Chinese patients with VVC. Caspofungin, voriconazole and fluconazole may be preferable to other azoles and terbinafine in the treatment of VVC.

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“…For the Neo-Sensitabs diffusion method, the isolates were tested on Mueller-Hinton agar plates and by following the guidelines for molds. Tablets 9 mm in diameter containing 5 g of PSC were provided by Rosco Laboratory (6). To determine the MFCs, 20 l of each well that showed complete inhibition (100% inhibition or an optically clear well) was plated onto potato dextrose agar (PDA) plates.…”

Section: Methodsmentioning

confidence: 99%

Correlation between In Vitro Activity of Posaconazole and In Vivo Efficacy against Rhizopus oryzae Infection in Mice

Rodríguez

Pastor

Sutton

et al. 2010

Antimicrob Agents Chemother

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We have evaluated the in vitro activity of posaconazole (PSC) against 50 clinical strains of Rhizopus oryzae using a broth microdilution method, the Neo-Sensitabs tablet diffusion method, and minimal fungicidal concentration (MFC) determination. In general, PSC showed low MICs against this fungus, and the MICs correlated with the inhibition zone diameters. Most of the MFCs, however, were from 1 to 4 dilutions higher than their corresponding MICs. We then investigated the efficacies of several different doses of PSC in a murine model. All treatments began 24 h after challenge and lasted for 7 days. The drug was administered twice a day to mice infected with three strains that showed intermediate PSC susceptibility (MIC ‫؍‬ 2 g/ml) and three PSC-susceptible strains (MIC ‫؍‬ 0.25 g/ml). A dose of 10 mg/kg of body weight was ineffective, while doses of 20 and 30 mg/kg prolonged the survival of the mice. The 50 strains tested were segregated into two groups on the basis of the in vitro data. For the group with the most strains (85%), the strains had low PSC MICs, mice infected with the strains showed higher rates of survival (30 to 40%), and PSC was able to reduce the fungal load in the kidney and less regularly in the brain. For the second group (15% of the strains), the strains had intermediate PSC MICs, mice infected with the strains had lower survival rates (10 to 20%), and PSC treatment resulted in variable and no reductions in the fungal loads in the kidneys and brains, respectively.Infections caused by some fungi of the order Mucorales are highly invasive and potentially fatal, and they mainly affect patients with diabetes mellitus or hematological malignances (20). In a recent survey of the occurrence of Mucorales in clinical samples in the United States, approximately half of the isolates identified belonged to the species Rhizopus oryzae (2). Treatment of Mucorales infections is based on four critical factors: rapid diagnosis, removal of predisposing factors, surgical debridement, and appropriate antifungal therapy, with liposomal amphotericin B (LAMB) being the drug of choice (21). Although posaconazole (PSC) has been demonstrated to be less effective than LAMB for the treatment of human R. oryzae infections and its use is not recommended as the primary treatment, this drug is considered a reasonable option for patients who are refractory to or intolerant of polyenes (8, 22). PSC has been tested as salvage therapy in several clinical trials, 14 to 37% of the patients showed a complete response (8,22). However, even in such cases the actual role of this drug is difficult to assess, as most of these patients had previously been treated with AMB or their lipid formulations. It is also unknown whether these success rates were related to the patients' immune status and/or other conditions or to the susceptibility of the strains involved in these infections. Furthermore, in clinical trials in which PSC has been evaluated, the fungi involved were not identified to the species level, thereby making it impossible t...

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Comparison of Neo-Sensitabs Tablet Diffusion Assay with CLSI Broth Microdilution M38-A and Disk Diffusion Methods for Testing Susceptibility of Filamentous Fungi with Amphotericin B, Caspofungin, Itraconazole, Posaconazole, and Voriconazole

Cited by 36 publications

References 19 publications

Evaluation of the In Vitro Activity of Voriconazole As Predictive of In Vivo Outcome in a Murine Aspergillus fumigatus Infection Model

Evaluation of the In Vitro Activity of Voriconazole As Predictive of In Vivo Outcome in a Murine Aspergillus fumigatus Infection Model

Molecular identification and antifungal susceptibility of 186 Candida isolates from vulvovaginal candidiasis in southern China

Correlation between In Vitro Activity of Posaconazole and In Vivo Efficacy against Rhizopus oryzae Infection in Mice

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