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

1997 ◽  
Vol 41 (4) ◽  
pp. 808-811 ◽  
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.

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

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
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.

scholarly journals Susceptibility Patterns and Molecular Identification of Trichosporon Species

2005 ◽  
Vol 49 (10) ◽  
pp. 4026-4034 ◽  
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.

scholarly journals 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

2017 ◽  
Vol 55 (6) ◽  
pp. 1812-1820 ◽  
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.

scholarly journals Relationship between the Antifungal Susceptibility Profile and the Production of Virulence-Related Hydrolytic Enzymes in Brazilian Clinical Strains ofCandida glabrata

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Maria Helena Galdino Figueiredo-Carvalho ◽  
Lívia de Souza Ramos ◽  
Leonardo Silva Barbedo ◽  
Jean Carlos Almeida de Oliveira ◽  
André Luis Souza dos Santos ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Antifungal Susceptibility ◽  
Hydrolytic Enzymes ◽  
Antifungal Drug ◽  
Clinical Strains ◽  
Antifungal Drug Resistance ◽  
Opportunistic Fungal Pathogen ◽  
Esterase Production ◽  
In Vitro Antifungal Susceptibility

Candida glabratais a facultative intracellular opportunistic fungal pathogen in human infections. Several virulence-associated attributes are involved in its pathogenesis, host-pathogen interactions, modulation of host immune defenses, and regulation of antifungal drug resistance. This study evaluated the in vitro antifungal susceptibility profile to five antifungal agents, the production of seven hydrolytic enzymes related to virulence, and the relationship between these phenotypes in 91 clinical strains ofC. glabrata. AllC. glabratastrains were susceptible to flucytosine. However, some of these strains showed resistance to amphotericin B (9.9%), fluconazole (15.4%), itraconazole (5.5%), or micafungin (15.4%). Overall,C. glabratastrains were good producers of catalase, aspartic protease, esterase, phytase, and hemolysin. However, caseinase and phospholipase in vitro activities were not detected. Statistically significant correlations were identified between micafungin minimum inhibitory concentration (MIC) and esterase production, between fluconazole and micafungin MIC and hemolytic activity, and between amphotericin B MIC and phytase production. These results contribute to clarify some of theC. glabratamechanisms of pathogenicity. Moreover, the association between some virulence attributes and the regulation of antifungal resistance encourage the development of new therapeutic strategies involving virulence mechanisms as potential targets for effective antifungal drug development for the treatment ofC. glabratainfections.

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

2021 ◽  
Author(s):  
Xue Ting Tan ◽  
Nurliyana binti Mohd Shuhairi ◽  
Stephanie Jane Ginsapu ◽  
Surianti Binti Shukor ◽  
Fairuz Binti Amran
Keyword(s):  
Amphotericin B ◽  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Etiologic Agent ◽  
Mycelial Form ◽  
In Vitro Susceptibility ◽  
Terbinafine Hydrochloride ◽  
Acquired Immunodeficiency ◽  
Immunodeficiency Syndrome

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.

scholarly journals Molecular Identification and Antifungal Susceptibility Patterns of Candida Species Isolated from Candidemia Patients in Yasuj, Southwestern Iran

2021 ◽  
Vol 14 (7) ◽  
Author(s):  
Shaghayegh Rostami Yasuj ◽  
Maral Gharaghani ◽  
Seyed Sajjad Khoramrooz ◽  
Marjan Salahi ◽  
Ali Keshtkari ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Amphotericin B ◽  
Molecular Identification ◽  
Candida Species ◽  
Antifungal Susceptibility ◽  
Hospitalized Patients ◽  
Susceptibility Tests ◽  
In Vitro Antifungal Susceptibility ◽  
Susceptibility Patterns

Background: Candidemia is the most common systemic infection in hospitalized patients causing high mortality. Hence, the diagnosis of this infection in the early stage with appropriate antifungal therapy is paramount. Objectives: The study aimed at molecular identification of Candida species isolated from candidemia patients and evaluation of the in vitro antifungal susceptibility patterns of these strains to fluconazole, amphotericin B, and caspofungin. Methods: In the present study, 800 hospitalized patients who were suspected to have candidemia were sampled. Candida species were isolated and identified based on morphological characteristics and PCR-sequencing of the ITS1-5.8S-ITS2 region. Antifungal susceptibility tests for fluconazole, amphotericin B, and caspofungin were performed according to the Clinical and Laboratory Standards Institute protocol M27-A3. Also, clinical data were recorded from the patients' records. Results: Twenty-seven patients among the sample of hospitalized patients were found to have candidemia. A total of 33.3% of candidemia patients were treated with amphotericin B, in which case the mortality rate was 14.8%. The majority of patients (59%) were from the neonatal intensive care unit, and premature birth was the most common underlying condition. Candida albicans (n = 18; 66.6%) was the most common species isolated from blood cultures, followed by C. parapsilosis (n = 7; 25.9%), C. pelliculosa (n = 1; 3.7%), and C. tropicalis (n = 1; 3.7%). Only one C. albicans isolate resistant to fluconazole (minimum inhibitory concentration = 32 µg/mL). Conclusions: Generally, C. albicans has been the most frequent causative agent of candidemia. Resistance to antifungal drugs among candidemia agents was rare. Also, the identification of Candida isolates at the species level with in vitro antifungal susceptibility tests helps manage candidemia patients better and decrease the mortality rate among them.

scholarly journals Genetic Diversity and In Vitro Antifungal Susceptibility of 200 Clinical and Environmental Aspergillus flavus Isolates

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Mojtaba Taghizadeh-Armaki ◽  
Mohammad Taghi Hedayati ◽  
Saham Ansari ◽  
Saeed Mahdavi Omran ◽  
Sasan Saber ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Aspergillus Flavus ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Content Type ◽  
Microdilution Method ◽  
Microsatellite Genotype ◽  
Broth Microdilution Method ◽  
In Vitro Antifungal Susceptibility

ABSTRACT Aspergillus flavus has been frequently reported as the leading cause of invasive aspergillosis in certain tropical and subtropical countries. Two hundred A. flavus strains originating from clinical and environmental sources and collected between 2008 and 2015 were phylogenetically identified at the species level by analyzing partial β-tubulin and calmodulin genes. In vitro antifungal susceptibility testing was performed against antifungals using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution method. In addition, genotyping was performed using a short-tandem-repeat (STR) assay of a panel of six microsatellite markers (A. flavus 2A, 2B, 2C, 3A, 3B, and 3C), in order to determine the genetic variation and the potential relationship between clinical and environmental isolates. The geometric means of the minimum inhibitory concentrations/minimum effective concentrations (MICs/MECs) of the antifungals across all isolates were (in increasing order): posaconazole, 0.13 mg/liter; anidulafungin, 0.16 mg/liter; itraconazole, 0.29 mg/liter; caspofungin, 0.42 mg/liter; voriconazole, 0.64 mg/liter; isavuconazole, 1.10 mg/liter; amphotericin B, 3.35 mg/liter; and flucytosine, 62.97 mg/liter. All of the clinical isolates were genetically different. However, an identical microsatellite genotype was found between a clinical isolate and two environmental strains. In conclusion, posaconazole and anidulafungin showed the greatest in vitro activity among systemic azoles and echinocandins, respectively. However, the majority of the A. flavus isolates showed reduced susceptibility to amphotericin B. Antifungal susceptibility of A. flavus was not linked with the clinical or environmental source of isolation. Microsatellite genotyping may suggest an association between clinical and environmental strains, although this requires further investigation.

scholarly journals Antifungal Susceptibility In Vitro Determined by the Etest(r) for Candida Obtained from the Oral Cavity of Irradiated and Elderly Individuals

2015 ◽  
Vol 26 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Edimilson Martins de Freitas ◽  
Larissa Cavalcanti Monteiro ◽  
Michelle Bonfim da Silva Fernandes ◽  
Hercílio Martelli Junior ◽  
Paulo Rogério Ferreti Bonan ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Candida Species ◽  
Antifungal Susceptibility ◽  
Culture Collection ◽  
Morphological Criteria ◽  
Group 2 ◽  
In Vitro Antifungal Susceptibility ◽  
Mic Minimum Inhibitory Concentration ◽  
Dose Dependent

This study aimed to evaluate the in vitro antifungal susceptibility of Candida species of head-and-neck-irradiated patients (Group 1), non-institutionalized (Group 2) and institutionalized elders (Group 3) using Etest(r) methodology. Candida was isolated from saliva and presumptively identified by CHROMagar Candida(r), confirmed by morphological criteria, carbohydrate assimilation (API 20C AUX(r)) and genetic typing (OPE 18). The collection was made from 29, 34 and 29 individuals (Groups 1, 2 and 3, respectively) with 67 isolates. Etest(r) strips (ketoconazole, itraconazole, fluconazole, amphotericin B and flucytosine) on RPMI (Roswell Park Memorial Institute) agar, on duplicate, were used to evaluate susceptibility. ATTC (American Type Culture Collection) 10231 (Candida albicans) was used as quality control. Among the 67 isolates of Candida species, most were susceptible to azoles, flucytosine and amphotericin B. None of the isolates showed resistance and dose-dependent susceptibility to amphotericin B. There were nine strains resistant to itraconazole, six to fluconazole and two to ketoconazole and ten dose-dependent, mainly to flucytocine. The highest MIC (minimum inhibitory concentration) to C. albicans, C. tropicalis, C. parapsilosis was 2.671 μg.mL-1, 8.104 μg.mL-1, 4.429 μg.mL-1, all for flucytosine. C. krusei and C. glabrata were associated with higher MIC for azoles and C. glabrata with higher MIC to flucytosine. In summary, susceptibility to all tested antifungal agents was evident. The isolates were more resistant to itraconazole and dose-dependent to flucytosine. A comparison of C. albicans in the three groups showed no outliers. Higher MIC was associated with C. krusei and C. glabrata.

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