scholarly journals Antifungal Drug Susceptibility Profile of Pichia anomala Isolates from Patients Presenting with Nosocomial Fungemia

2007 ◽  
Vol 51 (4) ◽  
pp. 1573-1576 ◽  
Author(s):  
Vânia Lúcia Ribeiro da Matta ◽  
Márcia de Souza Carvalho Melhem ◽  
Arnaldo Lopes Colombo ◽  
Maria Luiza Moretti ◽  
Laura Rodero ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Amphotericin B ◽  
Drug Susceptibility ◽  
Antifungal Drugs ◽  
Pichia Anomala ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
High Drug ◽  
Drug Concentrations

ABSTRACT In vitro susceptibility of 58 isolates of Pichia anomala to five antifungal drugs using two broth microdilution methods (CLSI and EUCAST) was analyzed. Low susceptibility to itraconazole was observed. Fluconazole, voriconazole, amphotericin B, and caspofungin showed good antifungal activity, although relatively high drug concentrations were necessary to inhibit the isolates.

scholarly journals Molecular Studies Reveal Frequent Misidentification of Aspergillus fumigatus by Morphotyping

2006 ◽  
Vol 5 (10) ◽  
pp. 1705-1712 ◽  
Author(s):  
S. Arunmozhi Balajee ◽  
David Nickle ◽  
Janos Varga ◽  
Kieren A. Marr
Keyword(s):  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Distinct Species ◽  
Enzyme Polymorphism ◽  
Antifungal Drugs ◽  
Clinical Isolates ◽  
Polymorphism Analysis ◽  
In Vitro Susceptibility ◽  
Epidemiological Surveys

ABSTRACT Aspergillus fumigatus has been understood to be the most common cause of invasive aspergillosis (IA) in all epidemiological surveys. However, recent studies have uncovered a large degree of genetic heterogeneity between isolates morphologically identified as A. fumigatus, leading to the description of a new species, Aspergillus lentulus. Here, we examined the genetic diversity of clinical isolates identified as A. fumigatus using restriction enzyme polymorphism analysis and sequence-based identification. Analysis of 50 clinical isolates from geographically diverse locations recorded the presence of at least three distinct species: A. lentulus, Aspergillus udagawae, and A. fumigatus. In vitro, A. lentulus isolates demonstrated decreased susceptibility to antifungal drugs currently used for IA, including amphotericin B, voriconazole, and caspofungin; A. udagawae isolates demonstrated decreased in vitro susceptibility to amphotericin B. Results of the present study demonstrate that current phenotypic methods to identify fungi do not differentiate between genetically distinct species in the A. fumigatus group. Differential antifungal susceptibilities of these species may account for some of the reported poor outcomes of therapy in clinical studies.

scholarly journals Phenotypic aspects of oral strains of Candida albicans in children with down's syndrome

2006 ◽  
Vol 66 (3) ◽  
pp. 939-944 ◽  
Author(s):  
E. L. Ribeiro ◽  
M. L. Scroferneker ◽  
M. S. Cavalhaes ◽  
C. C. Campos ◽  
G. M. Nagato ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Down's Syndrome ◽  
Test Group ◽  
Down’S Syndrome ◽  
Antifungal Drugs ◽  
Control Group ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Biological Aspects

The aim of this article is to characterize the biological aspects of oral strains of C. albicans in children with Down's syndrome. These yeasts were analyzed as to their macromorphological and enzymatic aspects and were tested as to their in vitro susceptibility to antifungal drugs using broth microdilution to determine the minimum inhibitory concentration (MIC). The morphotyping revealed that all oral C. albicans isolates from children with Down's syndrome promoted the formation of fringes regardless of size, while the control group presented smaller fringes. All oral C. albicans strains produced proteinase, but those with phospholipolytic activity showed greater enzyme capacity in the test group. In vitro susceptibility showed that all oral C. albicans isolates were sensitive to the drugs used.

scholarly journals Amphotericin B-conjugated polypeptide hydrogels as a novel innovative strategy for fungal infections

2018 ◽  
Vol 5 (3) ◽  
pp. 171814 ◽  
Author(s):  
Chang Shu ◽  
Tengfei Li ◽  
Wen Yang ◽  
Duo Li ◽  
Shunli Ji ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antifungal Activity ◽  
Amphotericin B ◽  
Fungal Infections ◽  
Antifungal Drugs ◽  
Water Soluble ◽  
Naphthalene Acetic Acid ◽  
Innovative Strategy ◽  
Molecular Arrangement

The present work is focused on the design and development of novel amphotericin B (AmB)-conjugated biocompatible and biodegradable polypeptide hydrogels to improve the antifungal activity. Using three kinds of promoting self-assembly groups (2-naphthalene acetic acid (Nap), naproxen (Npx) and dexamethasone (Dex)) and polypeptide sequence (Phe-Phe-Asp-Lys-Tyr, FFDKY), we successfully synthesized the Nap-FFDK(AmB)Y gels, Npx-FFDK(AmB)Y gels and Dex-FFDK(AmB)Y gels. The AmB-conjugated hydrogelators are highly soluble in different aqueous solutions. The cryo-transmission electron microscopy and scanning electron microscopy micrographs of hydrogels afford nanofibres with a width of 20–50 nm. Powder X-ray diffraction analyses demonstrate that the crystalline structures of the AmB and Dex are changed into amorphous structures after the formation of hydrogels. Circular dichroism spectra of the solution of blank carriers and the corresponding drug deliveries further help elucidate the molecular arrangement in gel phase, indicating the existence of turn features. The in vitro drug releases suggest that the AmB-conjugated hydrogels are suitable as drug-controlled release vehicles for hydrophobic drugs. The antifungal effect of AmB-conjugated hydrogels significantly exhibits the antifungal activity against Candida albicans . The results of the present study indicated that the AmB-conjugated hydrogels are suitable carriers for poorly water soluble drugs and for enhancement of therapeutic efficacy of antifungal drugs.

scholarly journals Evaluation of Amphotericin B Interpretive Breakpoints for Candida Bloodstream Isolates by Correlation with Therapeutic Outcome

2006 ◽  
Vol 50 (4) ◽  
pp. 1287-1292 ◽  
Author(s):  
Benjamin J. Park ◽  
Beth A. Arthington-Skaggs ◽  
Rana A. Hajjeh ◽  
Naureen Iqbal ◽  
Meral A. Ciblak ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
National Committee ◽  
Restricted Range ◽  
Broth Microdilution ◽  
Therapeutic Success ◽  
In Vitro Susceptibility ◽  
In Vitro Susceptibility Testing

ABSTRACT One hundred seven Candida bloodstream isolates (51 C. albicans, 24 C. glabrata, 13 C. parapsilosis, 13 C. tropicalis, 2 C. dubliniensis, 2 C. krusei, and 2 C. lusitaniae strains) from patients treated with amphotericin B alone underwent in vitro susceptibility testing against amphotericin B using five different methods. Fifty-four isolates were from patients who failed treatment, defined as death 7 to 14 days after the incident candidemia episode, having persistent fever of ≥5 days' duration after the date of the incident candidemia, or the recurrence of fever after two consecutive afebrile days while on antifungal treatment. MICs were determined by using the Clinical Laboratory Standards Institute (formally National Committee for Clinical Laboratory Standards) broth microdilution procedure with two media and by using Etest. Minimum fungicidal concentrations (MFCs) were also measured in two media. Broth microdilution tests with RPMI 1640 medium generated a restricted range of MICs (0.125 to 1 μg/ml); the corresponding MFC values ranged from 0.5 to 4 μg/ml. Broth microdilution tests with antibiotic medium 3 produced a broader distribution of MIC and MFC results (0.015 to 0.25 μg/ml and 0.06 to 2 μg/ml, respectively). Etest produced the widest distribution of MICs (0.094 to 2 μg/ml). However, none of the test formats studied generated results that significantly correlated with therapeutic success or failure.

scholarly journals Effect of pH on the In Vitro Activities of Amphotericin B, Itraconazole, and Flucytosine against Aspergillus Isolates

2004 ◽  
Vol 48 (8) ◽  
pp. 3147-3150 ◽  
Author(s):  
D. T. A. Te Dorsthorst ◽  
J. W. Mouton ◽  
C. J. P. van den Beukel ◽  
H. A. L. van der Lee ◽  
J. F. G. M. Meis ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Poor Correlation ◽  
Yeast Nitrogen Base ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Nitrogen Base ◽  
The Poor

ABSTRACT The in vitro susceptibilities of 21 Aspergillus isolates were tested against three antifungal agents in RPMI 1640 and yeast nitrogen base at pH 5.0 and 7.0 by a broth microdilution format of the NCCLS method. The MICs of amphotericin B and itraconazole were higher, while those of flucytosine were lower, at pH 5.0 than at pH 7.0. The poor correlation between in vitro results and clinical outcome could be due to a difference in pH between the in vitro susceptibility test and at the site of infection.

Comparative antifungal susceptibility analyses of Cryptococcus neoformans VNI and Cryptococcus gattii VGII from the Brazilian Amazon Region by the Etest, Vitek 2, and the Clinical and Laboratory Standards Institute broth microdilution methods

2019 ◽  
Vol 57 (7) ◽  
pp. 864-873 ◽  
Author(s):  
Marília Martins Nishikawa ◽  
Rodrigo Almeida-Paes ◽  
Fabio Brito-Santos ◽  
Carlos Roberto Nascimento ◽  
Miguel Madi Fialho ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Antifungal Susceptibility ◽  
Amazon Region ◽  
Antifungal Drugs ◽  
Epidemiological Surveillance ◽  
Broth Microdilution ◽  
Wild Type ◽  
Brazilian Amazon Region ◽  
Vitek 2

AbstractEarly diagnosis, efficient clinical support, and proper antifungal therapy are essential to reduce death and sequels caused by cryptococcosis. The emergence of resistance to the antifungal drugs commonly used for cryptococcosis treatment is an important issue of concern. Thus, the in vitro antifungal susceptibility of clinical strains from northern Brazil, including C. neoformans VNI (n = 62) and C. gattii VGII (n = 37), to amphotericin B (AMB), 5-flucytosine, fluconazole, voriconazole, and itraconazole was evaluated using the Etest and Vitek 2 systems and the standardized broth microdilution (CLSI-BMD) methodology. According to the CLSI-BMD, the most active in vitro azole was voriconazole (C. neoformans VNI modal MIC of 0.06 μg/ml and C. gattii VGII modal MIC of 0.25 μg/ml), and fluconazole was the least active (modal MIC of 4 μg/ml for both fungi). Modal MICs for amphotericin B were 1 μg/ml for both fungi. In general, good essential agreement (EA) values were observed between the methods. However, AMB presented the lowest EA between CLSI-BMD and Etest for C. neoformans VNI and C. gattii VGII (1.6% and 2.56%, respectively, P < .05 for both). Considering the proposed Cryptococcus spp. epidemiological cutoff values, more than 97% of the studied isolates were categorized as wild-type for the azoles. However, the high frequency of C. neoformans VNI isolates in the population described here that displayed non-wild-type susceptibility to AMB is noteworthy. Epidemiological surveillance of the antifungal resistance of cryptococcal strains is relevant due to the potential burden and the high lethality of cryptococcal meningitis in the Amazon region.

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

2014 ◽  
Vol 8 (08) ◽  
pp. 1037-1043 ◽  
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.

scholarly journals In Vitro and In Vivo Antifungal Activity of Amphotericin B Lipid Complex: Are Phospholipases Important?

1998 ◽  
Vol 42 (4) ◽  
pp. 767-771 ◽  
Author(s):  
Christine E. Swenson ◽  
Walter R. Perkins ◽  
Patricia Roberts ◽  
Imran Ahmad ◽  
Rachel Stevens ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Amphotericin B ◽  
Vascular Tissue ◽  
Therapeutic Index ◽  
Test Material ◽  
Lipid Complex ◽  
In Vitro Susceptibility ◽  
Amphotericin B Lipid Complex

ABSTRACT Amphotericin B lipid complex for injection (ABLC) is a suspension of amphotericin B complexed with the lipidsl-α-dimyristoylphosphatidylcholine (DMPC) andl-α-dimyristoylphosphatidylglycerol. ABLC is less toxic than amphotericin B deoxycholate (AmB-d), while it maintains the antifungal activity of AmB-d. Active amphotericin B can be released from ABLC by exogenously added (snake venom, bacteria, orCandida-derived) phospholipases or by phospholipases derived from activated mammalian vascular tissue (rat arteries). Such extracellular phospholipases are capable of hydrolyzing the major lipid in ABLC. Mutants of C. albicans that were resistant to ABLC but not AmB-d in vitro were deficient in extracellular phospholipase activity, as measured on egg yolk agar or as measured by their ability to hydrolyze DMPC in ABLC. ABLC was nevertheless effective in the treatment of experimental murine infections produced by these mutants. Isolates of Aspergillus species, apparently resistant to ABLC in vitro (but susceptible to AmB-d), were also susceptible to ABLC in vivo. We suggest that routine in vitro susceptibility tests with ABLC itself as the test material may not accurately predict the in vivo activity of ABLC and that the enhanced therapeutic index of ABLC relative to that of AmB-d in vivo may be due, in part, to the selective release of active amphotericin B from the complex at sites of fungal infection through the action of fungal or host cell-derived phospholipases.

scholarly journals Antifungal Activity of Brazilian Propolis Microparticles against Yeasts Isolated from Vulvovaginal Candidiasis

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Kelen Fátima Dalben Dota ◽  
Marcia Edilaine Lopes Consolaro ◽  
Terezinha Inez Estivalet Svidzinski ◽  
Marcos Luciano Bruschi
Keyword(s):  
Antifungal Activity ◽  
Amphotericin B ◽  
Biological Activities ◽  
Small Variation ◽  
Vulvovaginal Candidiasis ◽  
Antifungal Drugs ◽  
Broth Microdilution Method ◽  
Brazilian Propolis ◽  
Dose Dependent

Propolis, a resinous compound produced byApis melliferaL. bees, is known to possess a variety of biological activities and is applied in the therapy of various infectious diseases. The aim of this study was to evaluate thein vitroantifungal activity of propolis ethanol extract (PE) and propolis microparticles (PMs) obtained from a sample of Brazilian propolis against clinical yeast isolates of importance in the vulvovaginal candidiasis (VVC). PE was used to prepare the microparticles. Yeast isolates (n=89), obtained from vaginal exudates of patients with VVC, were exposed to the PE and the PMs. Moreover, the main antifungal drugs used in the treatment of VVC (Fluconazole, Voriconazole, Itraconazole, Ketoconazole, Miconazole and Amphotericin B) were also tested. Minimum inhibitory concentration (MIC) was determined according to the standard broth microdilution method. SomeCandida albicansisolates showed resistance or dose-dependent susceptibility for the azolic drugs and Amphotericin B. Non-C. albicansisolates showed more resistance and dose-dependent susceptibility for the azolic drugs thanC. albicans. However, all of them were sensitive or dose-dependent susceptible for Amphotericin B. All yeasts were inhibited by PE and PMs, with small variation, independent of the species of yeast. The overall results provided important information for the potential application of PMs in the therapy of VVC and the possible prevention of the occurrence of new symptomatic episodes.

scholarly journals In Vitro-Clinical Correlations for Amphotericin B Susceptibility in AIDS-Associated Cryptococcal Meningitis

2006 ◽  
Vol 51 (1) ◽  
pp. 343-345 ◽  
Author(s):  
R. A. Larsen ◽  
M. Bauer ◽  
A. E. Brouwer ◽  
A. Sanchez ◽  
A. M. Thomas ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Strong Correlation ◽  
Cryptococcal Meningitis ◽  
Drug Susceptibility ◽  
In Vitro Susceptibility ◽  
Broth Macrodilution ◽  
Clinical Correlations ◽  
Quantitative Response

ABSTRACT Reliable measures of antifungal drug susceptibility are needed. We tested the susceptibility of Cryptococcus neoformans from patients treated with amphotericin B. In vitro susceptibility employed a modified broth macrodilution method. We demonstrate a strong correlation between the quantitative measures of in vitro amphotericin B susceptibility and the quantitative response observed in patients.

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