In Vitro Susceptibility of Talaromyces Marneffei In Malaysia: Comparison of Yeast and Mycelial Phases

Abstract Talaromyces marneffei is an etiologic agent of talaromycosis. It can cause serious complications and death in immunocompromised patients, particularly in acquired immunodeficiency syndrome (AIDS) patients. This infectious disease is endemic in Southeast Asia including Malaysia. To date, published reports on the antifungal susceptibility profile of T. marneffei is very limited. The objective of this study is to determine the minimum inhibitory concentration (MIC) of T. marneffei in yeast and mycelial phases in Malaysia. In the year 2020, 27 clinical strains of T. marneffei were received from various hospitals in Malaysia. The identification was carried out using microscopic, macroscopic and molecular methods. Following that, the susceptibility of each isolate in both yeast and mycelial form to thirteen common antifungals was performed according to the broth microdilution in Clinical & Laboratory Standards Institute (CLSI) M38 method. The antifungals tested were anidulafungin, micafungin sodium, caspofungin diacetate, 5-fluorocytosine, amphotericin B and terbinafine hydrochloride, posaconazole, voriconazole, itraconazole, ketoconazole, ravuconazole, clotrimazole and isavuconazole. The geometric mean of all antifungals other than anidulafungin, micafungin sodium, caspofungin diacetate and 5-fluorocytosine against T. marneffei mould (mycelial) were >2 μg/ml. However, the geometric mean of all antifungals against T. marneffei yeast was <2 μg/ml. Our in vitro data suggests promising activities of amphotericin B, terbinafine hydrochloride, posaconazole, voriconazole, itraconazole, ketoconazole, ravuconazole, clotrimazole and isavuconazole against yeast and mould phases of T. marneffei.

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MICs and minimum fungicidal concentrations of amphotericin B, itraconazole, posaconazole and terbinafine in Sporothrix schenckii

Journal of Medical Microbiology ◽

10.1099/jmm.0.007609-0 ◽

2009 ◽

Vol 58 (12) ◽

pp. 1607-1610 ◽

Cited By ~ 32

Author(s):

Carolina Pereira Silveira ◽

Josep M. Torres-Rodríguez ◽

Eidi Alvarado-Ramírez ◽

Francisca Murciano-Gonzalo ◽

Maribel Dolande ◽

...

Keyword(s):

Amphotericin B ◽

Latin American ◽

Geometric Mean ◽

Sporothrix Schenckii ◽

Mycelial Form ◽

Appropriate Treatment ◽

Inappropriate Treatment ◽

Immunosuppressed Patients ◽

Identification Of Species

The in vitro susceptibility of 62 isolates of Sporothrix schenckii in its mycelial form, from Latin-American countries (Peru, Venezuela, Brazil and Uruguay) and Spain, to amphotericin B (AB), itraconazole (IZ), posaconazole (PZ) and terbinafine (TB) was determined by measuring the MICs and minimum fungicidal concentrations (MFCs) using a standardized Clinical and Laboratory Standards Institute method. In general, TB was the most active drug, with the lowest geometric mean (GM) MIC and MFC values amongst isolates from the five countries tested. IZ and PZ showed almost the same activity against all strains tested, except for isolates from Uruguay where IZ gave the highest GM MIC (10.68 mg l−1). AB showed the widest MIC range (0.03–16.0 mg l−1); however, this drug was less active against 79 % of isolates (MICs above 1 mg l−1). MFCs were 5 to 20 times higher than the MICs, but the lowest GM MFC and range values were found for TB. IZ and PZ gave the highest GM MFC. MFC may be a better predictor of therapeutic response than MIC, especially in immunosuppressed patients, making the use of IZ and PZ an inappropriate treatment. There were some differences in susceptibility according to the geographical source of the isolates, with the MIC being lower for TB in Venezuelan strains (P=0.066) and the MFC higher for PZ in Peruvian strains (P=0.02). Thus, geographical origin may be important for appropriate treatment, and may relate to the identification of species of the S. schenckii complex.

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Susceptibility Patterns and Molecular Identification of Trichosporon Species

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.10.4026-4034.2005 ◽

2005 ◽

Vol 49 (10) ◽

pp. 4026-4034 ◽

Cited By ~ 124

Author(s):

Juan L. Rodriguez-Tudela ◽

Teresa M. Diaz-Guerra ◽

Emilia Mellado ◽

Virginia Cano ◽

Cecilia Tapia ◽

...

Keyword(s):

Amphotericin B ◽

Geometric Mean ◽

Antifungal Susceptibility ◽

Intergenic Spacer ◽

Clinical Isolates ◽

Rrna Genes ◽

Correct Identification ◽

Its Sequencing ◽

Trichosporon Species

ABSTRACT The physiological patterns, the sequence polymorphisms of the internal transcriber spacer (ITS), and intergenic spacer regions (IGS) of the rRNA genes and the antifungal susceptibility profile were evaluated for their ability to identify Trichosporon spp. and their specificity for the identification of 49 clinical isolates of Trichosporon spp. Morphological and biochemical methodologies were unable to differentiate among the Trichosporon species. ITS sequencing was also unable to differentiate several species. However, IGS1 sequencing unambiguously identified all Trichosporon isolates. Following the results of DNA-based identification, Trichosporon asahii was the species most frequently isolated from deep sites (15 of 25 strains; 60%). In the main, other Trichosporon species were recovered from cutaneous samples. The majority of T. asahii, T. faecale, and T. coremiiforme clinical isolates exhibited resistance in vitro to amphotericin B, with geometric mean (GM) MICs >4 μg/ml. The other species of Trichosporon did not show high MICs of amphotericin B, and GM MICs were <1 μg/ml. Azole agents were active in vitro against the majority of clinical strains. The most potent compound in vitro was voriconazole, with a GM MIC ≤0.14 μg/ml. The sequencing of IGS correctly identified Trichosporon isolates; however, this technique is not available in many clinical laboratories, and strains should be dispatched to reference centers where these complex methods are available. Therefore, it seems to be more practical to perform antifungal susceptibility testing of all isolates belonging to Trichosporon spp., since correct identification could take several weeks, delaying the indication of an antifungal agent which exhibits activity against the infectious strain.

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In VitroAntifungal Susceptibility of Yeast and Mold Phases of Isolates of Dimorphic Fungal Pathogen Emergomyces africanus (Formerly Emmonsia sp.) from HIV-Infected South African Patients

Journal of Clinical Microbiology ◽

10.1128/jcm.02524-16 ◽

2017 ◽

Vol 55 (6) ◽

pp. 1812-1820 ◽

Cited By ~ 23

Author(s):

Tsidiso G. Maphanga ◽

Erika Britz ◽

Thokozile G. Zulu ◽

Ruth S. Mpembe ◽

Serisha D. Naicker ◽

...

Keyword(s):

Amphotericin B ◽

Fungal Pathogen ◽

Geometric Mean ◽

Antifungal Susceptibility ◽

Outcome Data ◽

Internal Transcribed Spacer Region ◽

Content Type ◽

Susceptibility Data ◽

Custom Made

ABSTRACTDisseminated emmonsiosis is an important AIDS-related mycosis in South Africa that is caused byEmergomycesafricanus, a newly described and renamed dimorphic fungal pathogen.In vitroantifungal susceptibility data can guide management. Identification of invasive clinical isolates was confirmed phenotypically and by sequencing of the internal transcribed spacer region. Yeast and mold phase MICs of fluconazole, voriconazole, itraconazole, posaconazole, caspofungin, anidulafungin, micafungin, and flucytosine were determined with custom-made frozen broth microdilution (BMD) panels in accordance with Clinical and Laboratory Standards Institute recommendations. MICs of amphotericin B, itraconazole, posaconazole, and voriconazole were determined by Etest. Fifty uniqueE. africanusisolates were tested. The yeast and mold phase geometric mean (GM) BMD and Etest MICs of itraconazole were 0.01 mg/liter. The voriconazole and posaconazole GM BMD MICs were 0.01 mg/liter for both phases, while the GM Etest MICs were 0.001 and 0.002 mg/liter, respectively. The fluconazole GM BMD MICs were 0.18 mg/liter for both phases. The GM Etest MICs of amphotericin B, for the yeast and mold phases were 0.03 and 0.01 mg/liter. The echinocandins and flucytosine had very limitedin vitroactivity. Treatment and outcome data were available for 37 patients; in a multivariable model including MIC data, only isolation from blood (odds ratio [OR], 8.6; 95% confidence interval [CI], 1.3 to 54.4;P= 0.02) or bone marrow (OR, 12.1; 95% CI, 1.2 to 120.2;P= 0.03) (versus skin biopsy) was associated with death.In vitrosusceptibility data support the management of disseminated emmonsiosis with amphotericin B, followed by itraconazole, voriconazole, or posaconazole. Fluconazole was a relatively less potent agent.

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Accuracy in clinical examinations for the diagnosis of vulvovaginitis by CANDIDA SPP. and IN VITRO susceptibility to the main antifungals

Revista de Patologia Tropical / Journal of Tropical Pathology ◽

10.5216/rpt.v49i3.64233 ◽

2020 ◽

Vol 49 (3) ◽

Author(s):

Andressa Santana Santos ◽

Ana Laura Sene Amancio Zara ◽

Fábio Silvestre Ataídes ◽

Elisangela Gomes da Silva ◽

Vivianny Aparecida Queiroz Freitas ◽

...

Keyword(s):

Amphotericin B ◽

Clinical Diagnosis ◽

High Resistance ◽

Antifungal Susceptibility ◽

Vulvovaginal Candidiasis ◽

Vaginal Mucosa ◽

Candida Spp ◽

In Vitro Susceptibility ◽

Gynecology And Obstetrics

Vulvovaginal candidiasis (VVC) is a common infection. This work aims to determine the positive predictive value (PPV) of the clinical diagnosis of VVC and to characterize Candida species isolated from the vaginal mucosa. This cross-sectional study was conducted from February 2016 to February 2017 at the Gynecology and Obstetrics Outpatient Clinic of the Hospital das Clínicas, in Goiânia, Goiás State, Brazil. The study included samples of vaginal secretion from 55 women who complained of vaginal discharge and itching as their main symptoms. The PPV of the clinical diagnosis of VVC was estimated in comparison to the laboratory culture method. The phenotypic methods and molecular tests were performed to identify Candida spp. In vitro susceptibility of Candida spp. isolates to fluconazole, itraconazole, clotrimazole, nystatin, and amphotericin B was determined using the broth microdilution assay. Yeast growth using the enzymes protease, phospholipase, and hemolysin was carried out in media containing respectively bovine albumin, egg yolk, and sheep erythrocytes. A PPV of 61.8% (34/55) was determined. Among the 55 vulvovaginal samples collected, we identified 36 isolates in whichC. albicans was the most common species. High resistance to fluconazole and low minimal inhibitory concentration (MIC) values for clotrimazole, nystatin and amphotericin B were observed. All isolates were proteinase and hemolysin producers, while seven strains were phospholipase negative. The clinical diagnosis of VVC presented a moderate PPV, which meant that cultures had to be conducted in the laboratory to confirm infection. The high resistance to fluconazole and itraconazole indicated the importance of the in vitro susceptibility test.KEY WORDS: Vulvovaginal candidiasis; antifungal susceptibility; enzymatic activity

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In vitro susceptibility of isolates ofSporothrix schenckiito amphotericin B, itraconazole, and terbinafine: comparison of yeast and mycelial forms

Canadian Journal of Microbiology ◽

10.1139/w06-040 ◽

2006 ◽

Vol 52 (9) ◽

pp. 843-847 ◽

Cited By ~ 20

Author(s):

Lidiane Meire Kohler ◽

Betânia Maria Soares ◽

Daniel de Assis Santos ◽

Maria Elisabete Da Silva Barros ◽

Júnia Soares Hamdan

Keyword(s):

Amphotericin B ◽

Clinical Laboratory ◽

Sporothrix Schenckii ◽

Clinical Findings ◽

In Vitro Tests ◽

Mycelial Form ◽

In Vitro Susceptibility ◽

Significant Difference ◽

Different Levels

Forty-three clinical isolates of Sporothrix schenckii derived from humans and animals were evaluated in vitro for their susceptibility to amphotericin B, itraconazole, and terbinafine. MICs were determined by the method of micro dilution in liquid media, using protocols M27-A2 for the yeast form and M38-A for the mycelial form, both standardized by the Clinical Laboratory Standards Institute. In general, higher MICs were found for the mycelial form (intervals of up to two dilutions). In the case of amphotericin B, a significant difference in activity was observed, with higher values (p < 0.05) found for the mycelial form. MICs for itraconazole and terbinafine were similar for both yeast and mycelial forms but slightly higher for mycelia. Although data presented here indicate different levels of susceptibility when both growth forms were compared, indicating an intrinsic difference between them, it is still difficult to draw a consensus as to which form correlates better with clinical findings. More studies are necessary to determine the criteria for in vitro tests that will lead to efficient therapeutic choices.Key words: Sporothrix schenckii, susceptibility testing, antifungal drug.

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Molecular typing and in vitro antifungal susceptibility of Cryptococcus spp from patients in Midwest Brazil

The Journal of Infection in Developing Countries ◽

10.3855/jidc.4446 ◽

2014 ◽

Vol 8 (08) ◽

pp. 1037-1043 ◽

Cited By ~ 13

Author(s):

Olivia Cometti Favalessa ◽

Daphine Ariadne Jesus De Paula ◽

Valeria Dutra ◽

Luciano Nakazato ◽

Tomoko Tadano ◽

...

Keyword(s):

Amphotericin B ◽

Fungal Infections ◽

Antifungal Susceptibility ◽

Cryptococcus Gattii ◽

Antifungal Drugs ◽

Northeastern Brazil ◽

In Vitro Susceptibility ◽

Mato Grosso ◽

Hiv Negative

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.

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In Vitro Activity of Novel Antifungal Olorofim against Filamentous Fungi and Comparison to Eight Other Antifungal Agents

Journal of Fungi ◽

10.3390/jof7050378 ◽

2021 ◽

Vol 7 (5) ◽

pp. 378

Author(s):

Ourania Georgacopoulos ◽

Natalie S. Nunnally ◽

Eric M. Ransom ◽

Derek Law ◽

Mike Birch ◽

...

Keyword(s):

Antifungal Activity ◽

Amphotericin B ◽

Fungal Infections ◽

Fusarium Species ◽

Geometric Mean ◽

Treatment Options ◽

Antifungal Susceptibility ◽

Dihydroorotate Dehydrogenase ◽

Drug Classes

Olorofim is a novel antifungal drug that belongs to the orotomide drug class which inhibits fungal dihydroorotate dehydrogenase (DHODH), thus halting pyrimidine biosynthesis and ultimately DNA synthesis, cell growth and division. It is being developed at a time when many invasive fungal infections exhibit antifungal resistance or have limited treatment options. The goal of this study was to evaluate the in vitro effectiveness of olorofim against a large collection of recently isolated, clinically relevant American mold isolates. In vitro antifungal activity was determined for 246 azole-susceptible Aspergillus fumigatus isolates, five A. fumigatus with TR34/L98H-mediated resistance, 19 Rhizopus species isolates, 21 Fusarium species isolates, and one isolate each of six other species of molds. Olorofim minimum inhibitory concentrations (MICs) were compared to antifungal susceptibility testing profiles for amphotericin B, anidulafungin, caspofungin, isavuconazole, itraconazole, micafungin, posaconazole, and voriconazole. Olorofim MICs were significantly lower than those of the echinocandin and azole drug classes and amphotericin B. A. fumigatus wild type and resistant isolates shared the same MIC50 = 0.008 μg/mL. In non-Aspergillus susceptible isolates (MIC ≤ 2 μg/mL), the geometric mean (GM) MIC to olorofim was 0.54 μg/mL with a range of 0.015–2 μg/mL. Olorofim had no antifungal activity (MIC ≥ 2 μg/mL) against 10% of the collection (31 in 297), including some isolates from Rhizopus spp. and Fusarium spp. Olorofim showed promising activity against A. fumigatus and other molds regardless of acquired azole resistance.

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Comparison of in vitro susceptibility of different azoles agents against dermatophytes

10.21203/rs.2.19976/v1 ◽

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).

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Effects of incubation temperature, inoculum size, and time of reading on broth microdilution susceptibility test results for amphotericin B fgainst Fusarium.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.41.4.808 ◽

1997 ◽

Vol 41 (4) ◽

pp. 808-811 ◽

Cited By ~ 18

Author(s):

I Pujol ◽

J Guarro ◽

J Sala ◽

M D Riba

Keyword(s):

Amphotericin B ◽

Incubation Time ◽

Incubation Temperature ◽

Geometric Mean ◽

Antifungal Susceptibility ◽

Inoculum Size ◽

Test Results ◽

Fusarium Spp ◽

In Vitro Antifungal Susceptibility

In vitro antifungal susceptibility testing for filamentous fungi remains unstandardized and is unreliable for determining adequate therapy. A study was performed to evaluate the effect of inoculum size (10(2), 10(3), 10(4), and 10(5) conidia/ml), incubation time (48 and 72 h), and temperature (25, 30, and 35 degrees C) on MICs of amphotericin B for Fusarium spp. (20 strains). The inoculum size showed the clearest effect: when the inoculum was varied from 10(2) to 10(5) conidia/ml, the geometric mean MICs showed increases of between 10- and 19-fold in all the combined conditions of temperature and incubation time assayed. Time of incubation had less effect (increases of between two- and threefold in approximately half of the geometric mean MICs), and temperature especially had little effect (the increases were no higher than twofold). The effects of interaction between inoculum size and temperature on MICs were not statistically significant, while the combined effects of inoculum size and time of reading and of time of reading and temperature produced systematic variation in MICs.

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In Vitro Antifungal Susceptibility ofCandidaSpecies Isolated from Iranian Patients with Denture Stomatitis

BioMed Research International ◽

10.1155/2018/3086586 ◽

2018 ◽

Vol 2018 ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

Saeid Mahdavi Omran ◽

Maryam Rezaei Dastjerdi ◽

Maryam Zuashkiani ◽

Vahid Moqarabzadeh ◽

Mojtaba Taghizadeh-Armaki

Keyword(s):

Amphotericin B ◽

Geometric Mean ◽

Antifungal Susceptibility ◽

Restriction Enzymes ◽

Denture Stomatitis ◽

Pcr Rflp ◽

Causative Agents ◽

In Vitro Antifungal Susceptibility ◽

Iranian Patients

Background.Candida-associated denture stomatitis (CADS) is a common fungal infection in people who wear dentures. The main objective of this study was to make molecular identification of causative agents of CADS and in vitro antifungal susceptibility testing (AFST) in the Iranian patients with denture stomatitis.Methods. A total of 134Candidaspp. were obtained from patients with denture stomatitis. TheCandidaspp. were identified using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) involving the universal internal transcribed spacer (ITS1 and ITS4) primers, which were subjected to digestion with MspI and BlnI restriction enzymes. The in vitro antifungal susceptibility ofCandidaspp. to fluconazole (FLC), terbinafine (TRB), itraconazole (ITC), voriconazole (VRC), posaconazole (POS), ketoconazole (KET), amphotericin B (AMB), and caspofungin (CAS) was evaluated using the Clinical and Laboratory Standards Institute M27-A3 and M27-S4 guidelines.Results. Overall,C. albicanswas the most commonly isolated species (n=84; 62.6%), followed byC. glabrata(n=23; 17.2%),C. tropicalis(n=16; 12%), andC. parapsilosis(n=11; 8.2%). Posaconazole had the lowest geometric mean minimum inhibitory concentration (MIC) (0.03 μg/ml), followed by AMB (0.05 μg/ml), ITC (0.08 μg/ml), VRC (0.11 μg/ml), CAS (0.12 μg/ml), KET (0.15 μg/ml), and FLC (0.26 μg/ml).Discussion. Our study showed thatC. albicanswas most prevalent in Iranian patients with CADS and was susceptible to both azoles and amphotericin B. In addition, POS could be an appropriate alternative to the current antifungal agents used for the treatment of CADS, as well as in the treatment of recurrent candidiasis.

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