scholarly journals Antifungal Susceptibility of Dermatophytes Isolated From Cutaneous Fungal Infections: The Vietnamese Experience

2019 ◽  
Vol 7 (2) ◽  
pp. 247-249
Author(s):  
Chau Van Tro ◽  
Khuong Ho Thi Ngoc ◽  
Thuong Nguyen Van ◽  
Khang Tran Hau ◽  
Marco Gandolfi ◽  
...  

AIM: Evaluate the resistance of dermatophytes to systemic antifungal drugs in the Vietnamese population. METHODS: We enrolled 101 patients with cutaneous dermatophytosis at the Dermato-Venereology hospital in HCMC from August 2016 to March 2017. All the specimens were subjected to direct examination (10% KOH mount) and culture on Sabouraud dextrose agar. In vitro antifungal sensitivity testing was done on species isolated from a culture with broth microdilution method. RESULTS: Direct microscopy was positive for dermatophytes in all patients. However this pathogen was found in fungal cultures in only 61.38% of patients. The main causative agent isolated was Trichophyton spp. (90.3%), followed by Microsporum spp. (8%) and Epidermophyton spp. (1.7%). Trichophyton spp. Has shown resistance to fluconazole, griseofulvin, ketoconazole, and itraconazole in 92.9%, 46.4%, 5.4% and 1.8% of strains, respectively. All Microsporum spp. Strains were found resistant to fluconazole and griseofulvin while resistance to ketoconazole was demonstrated in only 20% of strains and none of them was resistant to itraconazole. Epidermophyton spp strains were all resistant to fluconazole, griseofulvin, ketoconazole while none of them was resistant to itraconazole. CONCLUSION: Based upon our results, Itraconazole shows the greatest probability of efficacy in the treatment of cutaneous dermatophytosis in Vietnamese patients.

2015 ◽  
Vol 59 (6) ◽  
pp. 3675-3682 ◽  
Author(s):  
B. Risslegger ◽  
C. Lass-Flörl ◽  
G. Blum ◽  
M. Lackner

ABSTRACTFor antifungal susceptibility testing of nonsporulating or poorly sporulating dermatophytes, a fragmented-mycelium inoculum preparation method was established and compared to broth microdilution testing according to CLSI and EUCAST guidelines. Moreover, thein vitroactivity of new antifungal agents against dermatophytes was evaluated. Agreement between the mycelial inoculum method and the CLSI broth microdilution method was high (93% to 100%). Echinocandins (minimal effective concentration [MEC], ≤0.5 mg/liter) and posaconazole (MIC, ≤3.00 mg/liter) showed good activity against all tested dermatophytes.


2016 ◽  
Vol 7 (1) ◽  
pp. 11
Author(s):  
Sultana Razia ◽  
Shahida Anwar ◽  
Md. Ruhul Amin Miah ◽  
Najmun Nahar ◽  
Ripon Barua

<p><strong>Background:</strong> With increasing fungal disease many newer antifungal drugs are available with different spectrum of activ­ity. Antifungal susceptibility test will help clinicians for selection of effective drug and thereby treatment of patient.<strong> </strong></p><p><strong>Objective:</strong> The study was undertaken to perform a simple screening drug susceptibility test of T. rnbrum by Semi Solid Agar Antifungal Susceptibility (SAAS) <strong></strong></p><p><strong>Method:</strong> Perfonnance of susceptibility method was assessed by comparing the MICs of three commonly prescribed antifungal agents namely- tluconazole (FCZ), itraconazole (ITZ) and terbinafine (TER) to the CLSI (Clinical and Laboratory Standard Institute) recommended M-38, a broth microdilution method. <strong></strong></p><p><strong>Results:</strong> In SAAS method, among twenty nine T. rubrum, twenty five (86.2%) were susceptible (MIC range 0.5-64 µg/ml) to Fluconazole (FCZ) and four (13.7%) were resistant (MIC value &gt;64 µg/ml). In broth microdilution method, among twenty nine T. rubrum, twenty six (89.6%) were susceptible (MIC range 0.3-64 µg/ml) to FCZ and three (10.3%) were resistant (MIC value &gt;64 µg/ml). In case of both ITZ and TER, all were susceptible (MIC range 0.3-64 µg/ml) to both methods. The SAAS method demonstrated the susceptibility pattern of T. rubrum against FCZ, ITZ and TER usually within 72 to 96 hours after organism isolation and results were concordance with the results of CLSI broth microdilution method. <strong></strong></p><p><strong>Conclusion:</strong> Though it is a newer method with proper standardization of the test method, SAAS method is simple and easily applicable screening method for susceptibility testing of antifungal agents against dermatophytes in any microbiology laboratories.</p>


2002 ◽  
Vol 46 (10) ◽  
pp. 3236-3242 ◽  
Author(s):  
Robert S. Liao ◽  
Robert P. Rennie ◽  
James A. Talbot

ABSTRACT This report presents a fluorescent carboxyfluorescein diacetate (CFDA)-modified microdilution method used for the susceptibility testing of Candida albicans to amphotericin B, fluconazole, ketoconazole, itraconazole, voriconazole, and flucytosine. Four different broth microdilution susceptibility testing methods were simultaneously evaluated at 24 and 48 h. The MICs determined using the CFDA-modified method (MICcfda) were compared to those obtained by the standard broth microdilution method (MICvisual) and a procedure employing the indicator Alamar blue (MICalamar). The reference MIC was determined visually as recommended by the NCCLS M27-A protocol, and then quantified spectrophotometrically following agitation (MICspec). The CFDA-modified microdilution method was demonstrated to effectively determine the MICs for all the antifungal drugs tested at both 24 and 48 h. The results from both the MICspec and MICcfda methods yielded >80% agreement within ±1 dilution and >90% agreement within ±2 dilutions at 24 h in comparison to the reference MICvisual method, respectively. The trailing growth phenomenon that occurs with azole antifungal drugs and many strains of C. albicans did not inhibit the effectiveness of the MICspec and MICcfda methods. The MICspec and MICcfda methods shared 92.8% agreement within ±1 dilution at 24 h and 87.6% agreement within ±1 dilution at 48 h.


2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Shuwen Deng ◽  
Saham Ansari ◽  
Macit Ilkit ◽  
Haleh Rafati ◽  
Mohammad T. Hedayati ◽  
...  

ABSTRACT Trichophyton schoenleinii is an anthropophilic dermatophyte mainly causing tinea favosa of the scalp in certain regions of the world, especially Africa and Asia. We investigated the in vitro susceptibilities of 55 T. schoenleinii isolates collected over the last 30 years from Iran, Turkey, and China to 12 antifungals using the CLSI broth microdilution method. Our results revealed that terbinafine and ketoconazole were the most potent antifungal agents among those tested, independently of the geographic regions where strains were isolated.


2019 ◽  
Vol 16 (31) ◽  
pp. 12-17
Author(s):  
Gustavo Lima SOARES ◽  
Brenda Lavínia Calixto dos SANTOS ◽  
Brenna Ravena Araújo LUZ ◽  
Wylly Araújo de OLIVEIRA

Aspergillus species are a cause of a high number of fungal infections of difficult treatment, presenting an expressive number of deaths due to the complications in the severe cases of infection. The objective was to evaluate the antifungal action of carvacrol against Aspergillus species, as well as to evaluate the interactions when associated with amphotericin B or ketoconazole. The antifungal activity of carvacrol was evaluated by the broth microdilution method. The combinations of the substances were performed by the checkerboard methodology, to determine the Index of Fractional Inhibitory Concentration. Carvacrol showed antifungal activity against all Aspergillus strains used in the trials. In combinations of substances, only a combination of carvacrol and amphotericin B presented satisfactory results. Combinations of carvacrol and ketoconazole have not shown good. It is concluded that carvacrol is a good candidate for the antifungal drug because of its good activity against Aspergillus demonstrated in the present study, as well as in other studies in the literature. Their combination in vitro with amphotericin B or ketoconazole did not present any advantages over the use of antifungal drugs alone.


2019 ◽  
Vol 63 (7) ◽  
Author(s):  
Christiaan A. Rees ◽  
Ruina Bao ◽  
Michael E. Zegans ◽  
Robert A. Cramer

ABSTRACT The in vitro activities of two antifungal drugs in combination with four nonantifungal ophthalmic agents were evaluated using a broth microdilution method and a collection of eight Fusarium ocular isolates that exhibited resistance to both natamycin (MICs, 14 to 32 μg/ml) and voriconazole (MICs, 4 to >128 μg/ml). Synergistic and indifferent interactions were observed for natamycin and 5-fluorouracil and natamycin with timolol dependent on the Fusarium isolate tested. Isolate-dependent synergistic and indifferent interactions were also observed for natamycin with EDTA and natamycin with dorzolamide. Synergistic or indifferent interactions were observed for voriconazole with timolol and voriconazole with 5-fluorouracil depending on Fusarium isolate. Taken together, these data suggest that commonly used ophthalmic agents enhance the in vitro activity of antifungal drugs against drug-recalcitrant ocular fungal pathogens.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Fahriye Eksi ◽  
Efgan Dogan Gayyurhan ◽  
Iclal Balci

This study was performed to determine the distribution ofCandidaspecies isolated from the blood cultures of the patients hospitalized in our hospital and to investigate their antifungal susceptibility.Candidastrains were identified at species level by using classical methods and API ID 32C (bioMerieux, France) identification kits. The susceptibility of the strains to amphotericin B, fluconazole, voriconazole, and caspofungin was evaluated by using the reference broth microdilution method in document M27-A3 of the Clinical and Laboratory Standards Institute. Of the 111Candidastrains isolated, 47.7% were identified asC. albicansand 52.3% as non-albicansCandidastrains. The MIC ranges were 0.03–1 μg/mL for amphotericin B, 0.125–≥64 μg/mL for fluconazole, 0.03–16 μg/mL for voriconazole, and 0.015–0.25 μg/mL for caspofungin. AllCandidastrains were susceptible to amphotericin B and caspofungin. 10.8% isolates were resistant to fluconazole and 8.1% isolates were dose-dependent susceptible. While 0.9% isolate was resistant to voriconazole, 0.9% isolate was dose-dependent susceptible. In our study,C. albicansandC. parapsilosiswere the most frequently encountered agents of candidemia and it was detected that voriconazole with a low resistance rate might also be used with confidence in the treatment of infections occurring with these agents, primarily besides amphotericin B and caspofungin.


2011 ◽  
Vol 55 (6) ◽  
pp. 2606-2611 ◽  
Author(s):  
Nelesh P. Govender ◽  
Jaymati Patel ◽  
Marelize van Wyk ◽  
Tom M. Chiller ◽  
Shawn R. Lockhart ◽  
...  

ABSTRACTCryptococcus neoformansis the most common cause of meningitis among adult South Africans with HIV infection/AIDS. Widespread use of fluconazole for treatment of cryptococcal meningitis and other HIV-associated opportunistic fungal infections in South Africa may lead to the emergence of isolates with reduced fluconazole susceptibility. MIC testing using a reference broth microdilution method was used to determine if isolates with reduced susceptibility to fluconazole or amphotericin B had emerged among cases of incident disease. Incident isolates were tested from two surveillance periods (2002-2003 and 2007-2008) when population-based surveillance was conducted in Gauteng Province, South Africa. These isolates were also tested for susceptibility to flucytosine, itraconazole, voriconazole, and posaconazole. Serially collected isolate pairs from cases at several large South African hospitals were also tested for susceptibility to fluconazole. Of the 487 incident isolates tested, only 3 (0.6%) demonstrated a fluconazole MIC of ≥16 μg/ml; all of these isolates were from 2002-2003. All incident isolates were inhibited by very low concentrations of amphotericin B and exhibited very low MICs to voriconazole and posaconazole. Of 67 cases with serially collected isolate pairs, only 1 case was detected where the isolate collected more than 30 days later had a fluconazole MIC value significantly higher than the MIC of the corresponding incident isolate. Although routine antifungal susceptibility testing of incident isolates is not currently recommended in clinical settings, it is still clearly important for public health to periodically monitor for the emergence of resistance.


2006 ◽  
Vol 50 (12) ◽  
pp. 4027-4029 ◽  
Author(s):  
Lucio Vera-Cabrera ◽  
Barbara A. Brown-Elliott ◽  
Richard J. Wallace ◽  
Jorge Ocampo-Candiani ◽  
Oliverio Welsh ◽  
...  

ABSTRACT DA-7867 and DA-7157 are oxazolidinones active against pathogenic aerobic actinomycetes including Nocardia spp. and Mycobacterium tuberculosis. However, the activity of these drugs against nontuberculous mycobacterium (NTM) species is not known. In this work, we compared the susceptibilities of 122 clinical isolates and 29 reference species of both rapidly growing and slowly growing mycobacteria to linezolid, DA-7867, and DA-7157 by the broth microdilution method. The MICs for 50 and 90% of the strains tested (MIC50s and MIC90s, respectively) of DA-7867 and DA-7157 were lower than those of linezolid. In all of the cases, a MIC90 of <8 μg/ml was observed for all of the species tested in both groups of NTM. For M. kansasii and M. marinum isolates, the MIC90s of both DA-7867 and DA-7157 were less than 0.5 μg/ml. These results demonstrate the potential of these compounds to treat NTM infections.


2021 ◽  
Author(s):  
Xue Ting Tan ◽  
Stephanie Jane Ginsapu ◽  
Fairuz binti Amran ◽  
Salina binti Mohamed Sukur ◽  
Surianti binti Shukor

Abstract Background: Voriconazole is a trizaole antifungal to treat fungal infection. In this study, the susceptibility pattern of voriconazole against filamentous fungi was studied using Sensititre® YeastOne and Clinical & Laboratory Standards Institute (CLSI) M38 broth microdilution method. Methods: The suspected cultures of Aspergillus niger, A. flavus, A. fumigatus, A. versicolor, A. sydowii, A. calidoutus, A. creber, A. ochraceopetaliformis, A. tamarii, Fusarium solani, F. longipes, F. falciferus, F. keratoplasticum, Rhizopus oryzae, R. delemar, R. arrhizus, Mucor sp., Poitrasia circinans, Syncephalastrum racemosum and Sporothrix schenckii were received from hospitals. Their identification had been confirmed in our lab and susceptibility tests were performed using Sensititre® YeastOne and CLSI M38 broth microdilution method. The significant differences between two methods were calculated using Wilcoxon Sign Rank test.Results: Mean of the minimum inhibitory concentrations (MIC) for Aspergillus spp. and Fusarium were within 0.25 μg/mL-2.00 μg/mL by two methods except A. calidoutus, F. solani and F. keratoplasticum. Moreover, mean of MIC for S. schenkii were around 3.00 μg/mL by two methods. In contrast, mean of MIC for Rhizopus spp., Mucor sp., P. circinans and S. racemosum were ≥6.00 μg/mL by two methods. Generally, the MIC obtained by Sensititre YeastOne was one two-fold increase or decrease compared with the results obtained by CLSI method. The overall agreement between Sensititre YeastOne and CLSI methods to test susceptibility testing of voricaonazole was more than 70% except A. sydowii. The significant differences between two methods were significant when tested on A. niger, A. flavus, A. fumigatus, A. versicolor, A. sydowii, F. solani and S. schenkii. Conclusions: In conclusion, Sensititre YeastOne method appears to be an alternative procedure for antifungal susceptibility testing for some Malaysian moulds.


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