Evaluation of direct antifungal susceptibility testing methods of <i>Candida</i> spp. from positive blood culture bottles

Oz, Yasemin; Gokbolat, Egemen

doi:10.1002/jcla.22297

Cited by 7 publications

(7 citation statements)

References 12 publications

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“…In this context, the thiosulfinates derived from Allium spp., such as allicin, have demonstrated broad antifungal activity in numerous in vitro studies against yeasts of the genus Candida [ 21 , 22 , 23 ]. In the present work, the MICs obtained for antifungals were similar to those obtained in previous research, both in our geographical area [ 24 , 25 ] and in more remote areas [ 19 , 26 , 27 , 28 , 29 ]. The lowest MICs were obtained for C. albicans and C. tropicalis ; the highest for C. glabrata and C. krusei , especially in the case of azoles, which indicates that Candida species remain susceptible to commonly used antifungals and do not represent a problem for the therapeutic approach.…”

Section: Discussionsupporting

confidence: 90%

Antibacterial and Antifungal Activity of Propyl-Propane-Thiosulfinate and Propyl-Propane-Thiosulfonate, Two Organosulfur Compounds from Allium cepa: In Vitro Antimicrobial Effect via the Gas Phase

et al. 2020

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Propyl-propane thiosulfinate (PTS) and propyl-propane thiosulfonate (PTSO) are two volatile compounds derived from Allium cepa with a widely documented antimicrobial activity. The aim of this study was to evaluate their anti-candidiasis activity and the ability of its gaseous phase to inhibit bacterial and yeast growth in vitro. The minimum inhibitory concentration of various antifungal products (including PTS and PTSO) was determined versus 203 clinical isolates of Candida spp. through broth microdilution assay. Additionally, the antimicrobial activity through aerial diffusion of PTS and PTSO was evaluated over the growth of a collection of bacteria and yeasts cultivated in agar plates. All yeasts were susceptible to the antifungals tested, except C. glabrata and C. krusei, that showed azole resistance. PTSO (MIC50 and MIC90 ranged from 4 to 16 mg/L and 8 to 32 mg/L, respectively) was significantly more active against yeasts than PTS (MIC50 and MIC90 ranged from 16 to 64 mg/L and 32 to 64 mg/L). Values were higher than those obtained for antifungal drugs. Gaseous phases of PTS and PTSO generated growth inhibition zones whose diameters were directly related to the substances concentration and inversely related to the microbial inoculum. The quantification of PTS and PTSO levels reached in the growth media through aerial diffusion displayed a concentration gradient from the central zone to the periphery. Only P. aeruginosa ATCC 27853 showed resistance, while yeasts (C. albicans ATCC 200955 and C. krusei ATCC 6258) presented the higher susceptibility to both compounds. These results suggest that PTS and PTSO display antibacterial and anti-candidiasis activity in vitro through aerial diffusion, having potential use in human therapy.

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Section: Discussionsupporting

confidence: 90%

Antibacterial and Antifungal Activity of Propyl-Propane-Thiosulfinate and Propyl-Propane-Thiosulfonate, Two Organosulfur Compounds from Allium cepa: In Vitro Antimicrobial Effect via the Gas Phase

et al. 2020

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“…To date, only three studies have directly evaluated DDT use for assessing fluconazole susceptibility in Candida species isolated from positive blood cultures [ 10 , 11 , 24 ]. These studies reported excellent CA between conventional (using colonies subcultured from positive blood cultures) and direct (using blood culture broth) DDT of fluconazole susceptibility [ 10 , 11 ].…”

Section: Discussionmentioning

confidence: 99%

“…Disk diffusion testing (DDT), one of the oldest approaches to susceptibility testing, is still widely used in clinical laboratories because of its low cost and technical simplicity [ 8 ]. DDT has recently been used for the direct testing of bacterial or fungal susceptibility in positive blood cultures [ 9 – 11 ]. Methods for shortening the incubation times for DDT have recently been reported for several common bacterial pathogens, enabling faster reporting of antimicrobial susceptibility test results from positive blood cultures [ 9 , 12 ].…”

Section: Introductionmentioning

confidence: 99%

Disk Diffusion Susceptibility Testing for the Rapid Detection of Fluconazole Resistance in Candida Isolates

et al. 2021

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Background: Given the increased fluconazole resistance (FR) among Candida isolates, we assessed the suitability of disk diffusion susceptibility testing (DDT) for the early detection of FR using well-characterized Candida isolates.Methods: In total, 188 Candida isolates, including 66 C. albicans (seven Erg11 mutants), 69 C. glabrata (33 Pdr1 mutants), 29 C. parapsilosis (15 Erg11 mutants), and 24 C. tropicalis (eight Erg11 mutants) isolates, were tested in this study. FR was assessed using DDT according to the standard CLSI M44-ED3 method, except that two cell suspensions, Mc-Farland 0.5 (standard inoculum) and 2.5 (large inoculum), were used, and the inhibition zones were read at 2-hour intervals from 10 hours to 24 hours.Results: DDT results for the standard inoculum were readable after 14 hours (C. albicans, C. glabrata, and C. tropicalis) and 20 hours (C. parapsilosis) for > 95% of the isolates, whereas the results for the large inoculum were readable after 12 hours (C. glabrata and C. tropicalis), 14 hours (C. albicans), and 16 hours (C. parapsilosis) for > 95% of the isolates. Compared with the results produced using the CLSI M27-ED4 broth microdilution method, the first readable results from the DDT method for each isolate exhibited an agreement of 97.0%, 98.6%, 72.4%, and 91.7% for the standard inoculum and 100%, 98.6%, 96.6%, and 95.8% for the large inoculum for C. albicans, C. glabrata, C. parapsilosis, and C. tropicalis, respectively.Conclusions: DDT using large inoculum may detect FR rapidly and reliably in the four most common Candida species.

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“…The current methods for the rapid detection of resistance include molecular-based analyses [ 49 , 50 ], flow cytometry [ 51 ] or porous aluminum oxide (PAO)-based cultures [ 52 , 53 ], which deliver results within a few hours. Furthermore, the improvement of the conventional methods by the direct inoculation of standard tests with positive blood cultures [ 54 ] or shortening the time to result by automated approaches such as as the Vitek 2 yeast panel [ 55 , 56 , 57 ] have been investigated. However, all of these methods have their own limitations of applicability, diagnostic accuracy or time to result.…”

Section: Discussionmentioning

confidence: 99%

Rapid Antifungal Susceptibility Testing of Yeasts and Molds by MALDI-TOF MS: A Systematic Review and Meta-Analysis

Knoll

Ulmer

Lass‐Flörl

2021

JoF

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Due to the growing burden of fungal infections and a recent rise in antifungal resistance, antifungal susceptibility testing (AFST) is of increasing importance. The common methods of AFST have turnaround times of 24 to 48 h, and the available rapid methods are limited by applicability, cost-efficiency or accuracy. Given the urgency of adequate antifungal treatment in invasive mycoses, the need for the rapid and reliable detection of resistance is evident. In this systematic review and meta-analysis, we evaluated the diagnostic accuracy of AFST based on matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). Twelve studies were reviewed, and data for the comparative analysis of their accuracy and methodology were systematically extracted. Compared to broth dilution as the gold standard, MALDI-TOF MS-based AFST reached a pooled sensitivity and specificity of 91% (95% Confidence Interval [CI], 84% to 96%) and 95% (95% CI, 90% to 98%), respectively. A comparative analysis showed that the sensitivity was higher for the semi-quantitative matrix-assisted laser desorption ionization Biotyper antibiotic susceptibility test rapid assay (MBT ASTRA) technique (96%) than for the correlate composite index (CCI) approach (85%), which is based on spectrum changes. Turnaround times below eight hours reached better diagnostic values than longer incubation periods, qualifying MALDI-TOF MS-based AFST as a rapid and accurate method for the detection of antifungal resistance.

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Evaluation of direct antifungal susceptibility testing methods of Candida spp. from positive blood culture bottles

Cited by 7 publications

References 12 publications

Antibacterial and Antifungal Activity of Propyl-Propane-Thiosulfinate and Propyl-Propane-Thiosulfonate, Two Organosulfur Compounds from Allium cepa: In Vitro Antimicrobial Effect via the Gas Phase

Antibacterial and Antifungal Activity of Propyl-Propane-Thiosulfinate and Propyl-Propane-Thiosulfonate, Two Organosulfur Compounds from Allium cepa: In Vitro Antimicrobial Effect via the Gas Phase

Disk Diffusion Susceptibility Testing for the Rapid Detection of Fluconazole Resistance in Candida Isolates

Rapid Antifungal Susceptibility Testing of Yeasts and Molds by MALDI-TOF MS: A Systematic Review and Meta-Analysis

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