scholarly journals Regional Differences in Antifungal Susceptibility of the Prevalent Dermatophyte Trichophyton rubrum

2020 ◽  
Vol 186 (1) ◽  
pp. 53-70
Author(s):  
Y. Jiang ◽  
W. Luo ◽  
P. E. Verweij ◽  
Y. Song ◽  
B. Zhang ◽  
...  

AbstractIn vitro susceptibility testing for Trichophyton rubrum has shown resistance to terbinafine, azoles and amorolfine, locally, but epidemiological cutoffs are not available. In order to assess the appropriateness of current first-line antifungal treatment for T. rubrum in China, we characterized antifungal susceptibility patterns of Chinese T. rubrum strains to nine antifungals and also described the upper limits of wild-type (WT) minimal inhibitory concentrations (MIC) (UL-WT) based on our study and another six studies published during the last decades. Sixty-two clinical isolates originating from seven provinces in China were identified as T. rubrum sensu stricto; all Chinese strains showed low MICs to eight out of nine antifungal drugs. Terbinafine (TBF) showed the lowest MICs of all antifungal classes tested in both the Chinese and global groups, with a 97.5% UL-WT MIC-value of 0.03 mg/L. No non-WT isolates were observed for TBF in China, but were reported in 18.5% of the global group. Our study indicated that TBF was still the most active drug for Chinese T. rubrum isolates, and all strains were within the WT-population. TBF therefore remains recommended for primary therapy to dermatophytosis caused by T. rubrum in China now, but regular surveillance of dermatophytes and antifungal susceptibility is recommended.

2014 ◽  
Vol 8 (08) ◽  
pp. 1037-1043 ◽  
Author(s):  
Olivia Cometti Favalessa ◽  
Daphine Ariadne Jesus De Paula ◽  
Valeria Dutra ◽  
Luciano Nakazato ◽  
Tomoko Tadano ◽  
...  

Introduction: Cryptococcosis is a systemic fungal infection that affects humans and animals, mainly due to Cryptococcus neoformans and Cryptococcus gattii. Following the epidemic of acquired immunodeficiency syndrome (AIDS), fungal infections by C. neoformans have become more common among immunocompromised patients. Cryptococcus gattii has primarily been isolated as a primary pathogen in healthy hosts and occurs endemically in northern and northeastern Brazil. We to perform genotypic characterization and determine the in vitro susceptibility profile to antifungal drugs of the Cryptococcus species complex isolated from HIV-positive and HIV-negative patients attended at university hospitals in Cuiabá, MT, in the Midwestern region of Brazil. Methodology: Micromorphological features, chemotyping with canavanine-glycine-bromothymol blue (CGB) agar and genotyping by URA5-RFLP were used to identify the species. The antifungal drugs tested were amphotericin B, fluconazole, flucytosine, itraconazole and voriconazole. Minimum inhibitory concentrations (MICs) were determined according to the CLSI methodology M27-A3. Results: Analysis of samples yelded C. neoformans AFLP1/VNI (17/27, 63.0%) and C. gattii AFLP6/VGII (10/27, 37.0%). The MICs ranges for the antifungal drugs were: amphotericin B (0.5-1 mg/L), fluconazole (1-16 mg/L), flucytosine (1-16 mg/L), itraconazole (0.25-0.12 mg/L) and voriconazole (0.06-0.5 mg/L). Isolates of C. neoformans AFLP1/VNI were predominant in patients with HIV/AIDS, and C. gattii VGII in HIV-negative patients. The genotypes identified were susceptible to the antifungal drugs tested. Conclusion: It is worth emphasizing that AFLP6/VGII is a predominant genotype affecting HIV-negative individuals in Cuiabá. These findings serve as a guide concerning the molecular epidemiology of C. neoformans and C. gattii in the State of Mato Grosso.


2014 ◽  
Vol 2 (1) ◽  
Author(s):  
K R Reddy ◽  
S Ram Reddy

Investigations on antifungal drug susceptibility were carried out on 90 clinical isolates of Trichophyton rubrum, and Trichophyton mentagrophytes with four antifungal drugs, namely griseofulvin, fluconazole, itraconazole and terbinafine as suggested by National Committee for Clinical Laboratory Standards (NCCLS) M27–A (1997) document by broth macrodilution method to standardize in vitro antifungal susceptibility testing and to find out the Minimum Inhibitory Concentration (MIC) of the drugs. In this study, terbinafine was found to be the most efficient drug for all isolates. Terbinafine had the lowest MIC range of 0.001 g/ml to 0.09 g/ml and MIC50 was low at 0.005 g/ml and MIC90 was also low at 0.04 g/ml against T.rubrum; and MIC range of 0.001μg/ml to 0.19μg/ml with a MIC50 of 0.01μg/ml and MIC90 at 0.09μg/ml against T.mentagrophytes. Itraconazole showed antifungal activity superior to that of fluconazole, with a MIC range of 0.04g/ml to 1.56g/ml, with MIC50 at 0.19μg/ml and MIC90 at 1.56g/ml against T.rubrum; and MIC range of 0.04μg/ml to 1.56μg/ml, with MIC50 at 0.19μg/ml and MIC90 at 0.78μg/ml against T.mentagrophytes. Griseofulvin appears to be still a potent drug for management of dermatophytoses. Griseofulvin had a MIC range of 0.15g/ml to 5.07 g/ml with MIC50 at1.26 g/ml and MIC90 at 2.53 g/ml against T.rubrum; and MIC range of 0.31μg/ml to 5.07μg/ml with MIC50 at 1.26μg/ml and MIC90 at 2.53μg/ml against T.mentagrophytes. Fluconazole showed a high MIC range of 0.19 g/ml to 50 g/ml and MIC50 was high at 1.56g/ml and MIC90 was also high at 12.5 g/ml against T.rubrum; and a high MIC range of 0.09μg/ml to 25.0μg/ml, with MIC50 at 1.56μg/ml and MIC90 at 12.5μg/ml towards T.mentagrophytes. The technique was found to be easy to perform and reliable with consistent results.


2014 ◽  
Vol 89 (4) ◽  
pp. 581-586 ◽  
Author(s):  
Christiane Venske de Almeida Azambuja ◽  
Luciana Alves Pimmel ◽  
Gabriel Baracy Klafke ◽  
Melissa Orzechowski Xavier

2021 ◽  
Vol 12 ◽  
Author(s):  
Najwa Al-Odaini ◽  
Xiu-ying Li ◽  
Bing-kun Li ◽  
Xing-chun Chen ◽  
Chun-yang Huang ◽  
...  

This study analyzed the in vitro drug sensitivity of Cryptococcus spp. from Guangxi, Southern China. One hundred three strains of Cryptococcus were recovered from 86 patients; 14 were HIV positive and 72 were HIV negative. Ninety-two strains were identified as Cryptococcus neoformans var. grubii, while 11 strains were identified as Cryptococcus gattii (5 C. gattii sensu stricto and 6 Cryptococcus deuterogattii). The recovered strains were tested against commonly used antifungal drugs (fluconazole, amphotericin B, 5-fluorocytosine, itraconazole, and voriconazole) and to novel antifungal drugs (posaconazole and isavuconazole) using CLSI M27-A4 method. The results showed that all isolates were susceptible to most antifungal drugs, of which the minimum inhibitory concentration (MIC) ranges were as follows: 0.05–4 μg/ml for fluconazole, 0.25–1 μg/ml for amphotericin B; 0.0625–2 μg/ml for 5-fluorocytosine, 0.0625–0.25 μg/ml for itraconazole, 0.0078–0.25 μg/ml for voriconazole, 0.0313–0.5 μg/ml for posaconazole, 0.0020–0.125 μg/ml for isavuconazole for C. neoformans var. grubii isolates, and 1–16 μg/ml for fluconazole, 0.125–1 μg/ml for 5-fluorocytosine, 0.25–1 μg/ml for amphotericin B, 0.0625–0.25 μg/ml for itraconazole, 0.0156–0.125 μg/ml for voriconazole, 0.0156–0.25 μg/ml for posaconazole, and 0.0078–0.125 μg/ml for isavuconazole for C. gattii isolates. Furthermore, some C. neoformans var. grubii isolates were found to be susceptible-dose dependent to 5-fluorocytosine and itraconazole. In addition, a reduction in the potency of fluconazole against C. gattii is possible. We observed no statistical differences in susceptibility of C. neoformans var. grubii and C. gattii in the tested strains. Continuous observation of antifungal susceptibility of Cryptococcus isolates is recommended to monitor the emergence of resistant strains.


2007 ◽  
Vol 49 (5) ◽  
pp. 293-295 ◽  
Author(s):  
E.I. Nweze ◽  
C.C. Ogbonna ◽  
J.I. Okafor

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.


2014 ◽  
Vol 1 (4) ◽  
pp. 26-28
Author(s):  
KR Reddy ◽  
SR Reddy

Investigations on antifungal drug susceptibility were carried out on 90 clinical isolates of Trichophyton rubrum, and Trichophyton mentagrophytes with four antifungal drugs, namely griseofulvin, fluconazole, itraconazole and terbinafine as suggested by National Committee for Clinical Laboratory Standards (NCCLS) M27A (1997) document by broth macrodilution method to standardize in vitro antifungal susceptibility testing and to find out the Minimum Inhibitory Concentration (MIC) of the drugs. In this study, terbinafine was found to be the most efficient drug for all isolates. Terbinafine had the lowest MIC range of 0.001 g/mlto 0.09 g/ml and MIC50 was low at 0.005 g/ml and MIC90 was also low at 0.04 g/ml against T. rubrum; and MIC range of 0.001pg/ml to 0.19pg/ml with a MIC50 of 0.01pg/ml and MIC90 at 0.09 pg/ml against T. mentagrophytes. Itraconazole showed antifungal activity superior to that of fluconazole, with a MIC range of 0.04g/ml to l.56g/ml, with MIC50 at 0.19pg/m land MIC90 at l.56g/ml against T. rubrum; and MIC range of 0.04.g/ml to 1.56pg/ml, with MIC50 at 0.19pg/ml and MIC90 at 0.78pg/ml against T. mentagrophytes. Griseofulvin appears to be still a potent drug for management of dermatophytoses. Griseofulvin had a MIC range of 0.15g/ml to 5.07 g/ml with MIC50 at l.26 g/ml and MIC90 at 2.53 g/ml against T. rubrum; and MIC range of 0.31pg/ml to 5.07pg/ml with MIC50 at 1.26pg/ml and MIC90 at 2.53pg/ml against T. mentagrophytes. Fluconazole showed a high MIC range of 0.19 g/ml to 50 g/ml and MIC50 was high at 1.56g/ml and MIC90 was also high at 12.5 g/ml against T. rubrum; and a high MIC range of 0.09pg/ml to 25.0pg/ml, with MIC50 at 1.56pg/ml and MIC90 at 12.5pg/ml towards T. mentagrophytes. The technique was found to be easy to perform and reliable with consistent results.DOI: http://dx.doi.org/10.3126/jucms.v1i4.9569 Journal of Universal College of Medical Sciences (2013) Vol.1 No.04: 26-28


Author(s):  
Smita S. Kulkarni ◽  
Jayshree B. Bhakre ◽  
Ajit S. Damle

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xue Xu ◽  
Ali Naseri ◽  
Jos Houbraken ◽  
Farzaneh Akbari ◽  
Xiaodong Wang ◽  
...  

AbstractAspergillus species are emerging causative agents of non-dermatophyte mold onychomycosis. In this study, 48 Aspergillus isolates were obtained from patients with onychomycosis in Mashhad, Iran, during 2015–2018. The aim is to identify the Aspergillus isolates to the species level by using partial calmodulin and beta-tubulin gene sequencing and MALDI-TOF MS, and to evaluate their in vitro susceptibility to ten antifungal drugs: terbinafine, itraconazole, voriconazole, posaconazole, ravuconazole, isavuconazole, caspofungin, micafungin, anidulafungin and amphotericin B according to CLSI M38-A3. Our results indicate that A.flavus (n = 38, 79%) is the most common Aspergillus species causing onychomycosis in Mashhad, Iran. Other detected species were A. terreus (n = 3), A. tubingensis (n = 2), A. niger (n = 1), A. welwitschiae (n = 1), A. minisclerotigenes (n = 1), A. citrinoterreus (n = 1) and A. ochraceus (n = 1). Aspergillus flavus, A. terreus and A. niger isolates were correctly identified at the species level by MALDI-TOF MS, while all cryptic species were misidentified. In conclusion, A. flavus is the predominant Aspergillus species causing onychomycosis due to Aspergillus spp. in Mashhad, Iran. MALDI-TOF MS holds promise as a fast and accurate identification tool, particularly for common Aspergillus species. It is important that the current database of reference spectra, representing different Aspergillus species is expanded to increase the precision of the species-level identification. Terbinafine, posaconazole and echinocandins were in vitro most active against the studies Aspergillus isolates and terbinafine could be the first choice for treatment of onychomycosis due to Aspergillus.


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