scholarly journals Comparison of in vitro susceptibility of different azoles agents against dermatophytes

2020 ◽  
Author(s):  
Jie Liu ◽  
Lanting Liu ◽  
Xiaoyun Liu ◽  
Bo Yu ◽  
Xiaoping Hu
Keyword(s):  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Antifungal Resistance ◽  
Antifungal Susceptibility Testing ◽  
In Vitro Susceptibility

Abstract The research on antifungal resistance in dermatophytoses lags behind that on systemic mycose. Lack of datas of antifungal susceptibility testing in dermatophytoses is one reasion. 121 clinical dermatophytes isolates were tested against 6 azole antifungal agents according to the Clinical and Laboratory Standards Institute (CLSI) method. Geometric mean MIC of all isolates were in increasing order: isavuconazole (GM 0.06 mg/L), posaconazole (GM 0.10 mg/L), itraconazole (GM 0.22 mg/L), voriconazole (GM 0.32 mg/L), ketoconazole (GM 0.40 mg/L), fluconazole (GM 10.18 mg/L).

scholarly journals The Emerging Terbinafine-Resistant Trichophyton Epidemic: What Is the Role of Antifungal Susceptibility Testing?

Dermatology ◽  
2021 ◽  
pp. 1-20
Author(s):  
Julia J. Shen ◽  
Maiken C. Arendrup ◽  
Shyam Verma ◽  
Ditte Marie L. Saunte
Keyword(s):  
Gene Mutation ◽  
Susceptibility Testing ◽  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Squalene Epoxidase ◽  
Exclusion Criteria ◽  
Huge Variation

<b><i>Background:</i></b> Dermatophytosis is commonly encountered in the dermatological clinics. The main aetiological agents in dermatophytosis of skin and nails in humans are <i>Trichophyton</i> (<i>T</i>.) <i>rubrum</i>, <i>T. mentagrophytes</i> and <i>T. interdigitale</i> (former <i>T. mentagrophytes-</i>complex). Terbinafine therapy is usually effective in eradicating infections due to these species by inhibiting their squalene epoxidase (SQLE) enzyme, but increasing numbers of clinically resistant cases and mutations in the SQLE gene have been documented recently. Resistance to antimycotics is phenotypically determined by antifungal susceptibility testing (AFST). However, AFST is not routinely performed for dermatophytes and no breakpoints classifying isolates as susceptible or resistant are available, making it difficult to interpret the clinical impact of a minimal inhibitory concentration (MIC). <b><i>Summary:</i></b> PubMed was systematically searched for terbinafine susceptibility testing of dermatophytes on October 20, 2020, by two individual researchers. The inclusion criteria were <i>in vitro</i> terbinafine susceptibility testing of <i>Trichophyton (T.) rubrum</i>, <i>T. mentagrophytes</i> and <i>T. interdigitale</i> with the broth microdilution technique. The exclusion criteria were non-English written papers. Outcomes were reported as MIC range, geometric mean, modal MIC and MIC<sub>50</sub> and MIC<sub>90</sub> in which 50 or 90% of isolates were inhibited, respectively. The reported MICs ranged from &#x3c;0.001 to &#x3e;64 mg/L. The huge variation in MIC is partly explained by the heterogeneity of the <i>Trichophyton</i> isolates, where some originated from routine specimens (wild types) whereas others came from non-responding patients with a known SQLE gene mutation. Another reason for the great variation in MIC is the use of different AFST methods where MIC values are not directly comparable. High MICs were reported particularly in isolates with SQLE gene mutation. The following SQLE alterations were reported: F397L, L393F, L393S, H440Y, F393I, F393V, F415I, F415S, F415V, S443P, A448T, L335F/A448T, S395P/A448T, L393S/A448T, Q408L/A448T, F397L/A448T, I121M/V237I and H440Y/F484Y in terbinafine-resistant isolates.

scholarly journals ANTIFUNGAL SUSCEPTIBILITY TESTING: CURRENT ROLE FROM THE CLINICAL LABORATORY PERSPECTIVE

2014 ◽  
Vol 6 (1) ◽  
pp. e2014030 ◽  
Author(s):  
Brunella Posteraro ◽  
Riccardo Torelli ◽  
Elena De Carolis ◽  
Patrizia Posteraro ◽  
Maurizio Sanguinetti
Keyword(s):  
Drug Exposure ◽  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Clinical Resistance ◽  
Therapeutic Decision Making ◽  
Short Time

Despite availability of many antifungal agents, antifungal clinical resistance occurs, perhaps as a result of an infecting organism found to be resistant in vitro to one or more antifungals tested. Thus, antifungal susceptibility testing (AFST) results, if timely generated by the clinical microbiology and communicated to clinicians, can aid them in the therapeutic decision making, especially for difficult-to-treat invasive candidiasis and aspergillosis. Although recently refined AFST methods are commercially available to allow a close antifungal resistance surveillance in many clinical setting, novel assays, relying on short-time antifungal drug exposure of fungal isolates, are upcoming tools for AFST. Based on emerging technologies such as flow cytometry, MALDI-TOF mass spectrometry, and isothermal microcalorimetry, these assays could provide a reliable means for quicker and sensitive assessment of AFST.

scholarly journals In vitro susceptibility testing of dermatophytes isolated from pediatric cases in Nigeria against five antifungals

2007 ◽  
Vol 49 (5) ◽  
pp. 293-295 ◽  
Author(s):  
E.I. Nweze ◽  
C.C. Ogbonna ◽  
J.I. Okafor
Keyword(s):  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Antifungal Activities ◽  
Nigerian Children ◽  
In Vitro Susceptibility Testing

The antifungal activities of itraconazole, ketoconazole, fluconazole, terbinafine and griseofulvin were tested by broth microdilution methods against 71 isolates of dermatophytes isolated from Nigerian children. Most drugs were very active against all the dermatophytes and the MIC 90 ranged from 0.03 to 8.0 µg/mL. This appears to be the first documented data on the antifungal susceptibility testing of isolates of dermatophytes from Nigerian children.

scholarly journals Antifungal Susceptibility Testing of Dermatophytes: Establishing a Medium for Inducing Conidial Growth and Evaluation of Susceptibility of Clinical Isolates

2000 ◽  
Vol 38 (1) ◽  
pp. 341-344
Author(s):  
C. J. Jessup ◽  
J. Warner ◽  
N. Isham ◽  
I. Hasan ◽  
M. A. Ghannoum
Keyword(s):  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Antifungal Susceptibility Testing ◽  
Optimal Conditions ◽  
In Vitro Susceptibility ◽  
Conidial Formation ◽  
The Mean ◽  
Optimal Medium

ABSTRACT A standardized reference method for dermatophyte in vitro susceptibility testing is lacking. In a previous study, Norris et al. (H. A. Norris, B. E. Elewski, and M. A. Ghannoum, J. Am. Acad. Dermatol. 40(6, part 2):S9–S13) established the optimal medium and other growth variables. However, the earlier study did not address two issues: (i) selection of an optimal medium for conidial formation by dermatophytes and (ii) validation of the method with a large number of dermatophytes. The present study addresses these two points. To select which agar medium best supported conidial growth, representative isolates of dermatophytes were grown on different agars. Preliminary experiments showed that only oatmeal cereal agar supported the production of conidia by Trichophyton rubrum . We tested the abilities of 251 T. rubrum isolates to form conidia using three different cereal agars and potato dextrose agar. Overall, oatmeal cereal and rice agar media were comparable in their abilities to support T. rubrum conidial growth. Next, we used the oatmeal cereal agar for conidial formation along with the optimal conditions for dermatophyte susceptibility testing proposed by Norris et al. and determined the antifungal susceptibilities of 217 dermatophytes to fluconazole, griseofulvin, itraconazole, and terbinafine. Relative to the other agents tested, terbinafine possessed the highest antifungal activity against all of the dermatophytes. The mean ± standard error of the mean MICs of fluconazole, itraconazole, terbinafine, and griseofulvin were 2.07 ± 0.29, 0.13 ± 0.01, 0.002 ± 0.0003, and 0.71 ± 0.05 μg/ml, respectively. This study is the first step in the identification of optimal conditions that could be used for the standardization of the antifungal susceptibility testing method for dermatophytes. Inter- and intralaboratory agreement as well as clinical correlations need to be established.

Antifungal susceptibility testing and resistance

2017 ◽  
Author(s):  
Elizabeth M. Johnson
Keyword(s):  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Invasive Disease ◽  
Fungal Species ◽  
Antifungal Susceptibility Testing ◽  
Limiting Factors ◽  
Antifungal Drug Resistance

The availability of choice of systemically active antifungal agents and the proliferation in the number of fungal species implicated in invasive disease have meant that clinicians are increasingly looking for guidance from clinical laboratory results to help select the most appropriate agent. There are now well-established and predictable patterns of innate in vitro resistance to one or more antifungal agents associated with many yeast and mould species. This chapter provides definitions for the most frequently used terminology and outlines some of the issues surrounding antifungal susceptibility testing with yeast and mould isolates. Reference methods published by the Clinical Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) are discussed. Both innate and emergent antifungal drug resistance are increasingly recognized as limiting factors in the selection of antifungal agents, and the epidemiology and mechanisms of resistance are described for each of the major classes of antifungal agent.

scholarly journals In vitro susceptibility testing of four antifungal drugs against fungal isolates in onychomycosis

2018 ◽  
Vol 6 (8) ◽  
pp. 2774 ◽  
Author(s):  
Smita S. Kulkarni ◽  
Jayshree B. Bhakre ◽  
Ajit S. Damle
Keyword(s):  
Amphotericin B ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
Antifungal Drugs ◽  
Etiological Agent ◽  
Diffusion Method ◽  
In Vitro Susceptibility ◽  
Broth Macrodilution

Background: Onychomycosis is chronic fungal infection of fingernails and toenails. Variety of fungi cause onychomycosis. Due to importance of high prevalence rate of onychomycosis this study was conducted.Methods: In this study 100 patients suspected of onychomycosis were examined. Diagnosis of onychomycosis was based on the patient’s history, physical examination, microscopy and culture of nail specimens.Results: Direct microscopy of the nail clippings in 20% KOH solution was positive in 61% and culture was positive in 54% cases. The common etiological agent was dermatophytes (79.6% cases) followed by non dermatophyte moulds (11.1% cases) and yeasts (9.2% cases). Amongst dermatophytes, T. rubrum was found to be commonest etiological agent (57.6%) followed by T. mentagrophytes. We had performed the in vitro antifungal susceptibility testing of isolated fungal species against Amphotericin B, Fluconazole, Itraconazole and Terbinafine according to standard guidelines recommended by the CLSI. Antifungal susceptibility testing of dermatophytes and non-dermatophyte moulds was performed by broth macrodilution method. For Candida species we used broth macrodilution method as well as disk diffusion method. All three Candida albicans isolates were sensitive to amphotericin B, fluconazole and itraconazole. Two strains of Candida krusei were sensitive to amphotericin B and resistant to fluconazole and itraconazole. Two isolates of T. rubrum had MIC >64µg/ml and one T. Mentagrophytes isolate had MIC 32µg/ml for fluconazole. Among non dermatophyte moulds, Aspergillus niger and one isolate of Fusarium oxysporum showed high MICs against fluconazole.Conclusions: Terbinafine exhibited the lowest MICs among all the tested antifungal drugs.

Use of spectrophotometric reading for in vitro antifungal susceptibility testing ofAspergillusspp.

1999 ◽  
Vol 45 (10) ◽  
pp. 871-874 ◽  
Author(s):  
Eric Dannaoui ◽  
Florence Persat ◽  
Marie-France Monier ◽  
Elisabeth Borel ◽  
Marie-Antoinette Piens ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Antifungal Susceptibility Testing ◽  
Aspergillus Species ◽  
National Committee ◽  
Broth Microdilution Method

A comparative study of visual and spectrophotometric MIC endpoint determinations for antifungal susceptibility testing of Aspergillus species was performed. A broth microdilution method adapted from the National Committee for Clinical Laboratory Standards (NCCLS) was used for susceptibility testing of 180 clinical isolates of Aspergillus species against amphotericin B and itraconazole. MICs were determined visually and spectrophotometrically at 490 nm after 24, 48, and 72h of incubation, and MIC pairs were compared. The agreement between the two methods was 99% for amphotericin B and ranged from 95 to 98% for itraconazole. It is concluded that spectrophotometric MIC endpoint determination is a valuable alternative to the visual reference method for susceptibility testing of Aspergillus species.Key words: antifungal, susceptibility testing, Aspergillus, spectrophotometric reading.

Vaginitis Due To Pichia fermentans in a Patient Affected by Endometrial Cancer: A Novel Case Report

2021 ◽  
Vol 17 ◽  
Author(s):  
Zarifeh Adampour ◽  
Malihe Hasanzadeh ◽  
Hossein Zarrinfar ◽  
Maryam Nakhaei ◽  
Monika Novak Babič
Keyword(s):  
Endometrial Cancer ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Female Genital Tract ◽  
Antifungal Susceptibility Testing ◽  
Vein Thrombosis ◽  
Microbial Infections ◽  
Life Threatening ◽  
In Vitro Antifungal Susceptibility

Introduction: Endometrial cancer is one of the most common malignancies of the female genital tract, which can be serious or life-threatening. Microbial infections can be one of the underlying causes of this type of cancer. Case Presentation: The present study describes the isolation of Pichia fermentans (Candida firmentaria var. firmentaria) from the vaginal secretions of a 61-year-old woman affected by endometrial cancer. She reported abdominal pain and vaginal discharge for 3 months, and had a history of diabetes, hypertension, Deep Vein Thrombosis (DVT), and Acute Myeloid Leukemia (AML). The isolated yeast was identified based on nuclear ribosomal internal transcribed spacer (ITS1-ITS2 rDNA) sequence analysis. The in vitro antifungal susceptibility testing showed a higher effect for ketoconazole against P. fermentans than fluconazole, itraconazole and voriconazole. Conclusion: Correct differentiation between P. fermentans and other yeast should be considered. The in vitro antifungal susceptibility testing is recommended for rare yeast, and will help the physicians in providing the best treatment.

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