Antifungal susceptibility testing of Malassezia yeast: comparison of two different methodologies.

PubMed

Rojas, Florencia D; Córdoba, Susana B; de Los Ángeles Sosa, María; Zalazar, Laura C; Fernández, Mariana S; Cattana, María E; Alegre, Liliana R; Carrillo-Muñoz, Alfonso J; Giusiano, Gustavo E

2017-02-01

All Malassezia species are lipophilic; thus, modifications are required in susceptibility testing methods to ensure their growth. Antifungal susceptibility of Malassezia species using agar and broth dilution methods has been studied. Currently, few tests using disc diffusion methods are being performed. The aim was to evaluate the in vitro susceptibility of Malassezia yeast against antifungal agents using broth microdilution and disc diffusion methods, then to compare both methodologies. Fifty Malassezia isolates were studied. Microdilution method was performed as described in reference document and agar diffusion test was performed using antifungal tablets and discs. To support growth, culture media were supplemented. To correlate methods, linear regression analysis and categorical agreement was determined. The strongest linear association was observed for fluconazole and miconazole. The highest agreement between both methods was observed for itraconazole and voriconazole and the lowest for amphotericin B and fluconazole. Although modifications made to disc diffusion method allowed to obtain susceptibility data for Malassezia yeast, variables cannot be associated through a linear correlation model, indicating that inhibition zone values cannot predict MIC value. According to the results, disc diffusion assay may not represent an alternative to determine antifungal susceptibility of Malassezia yeast. © 2016 Blackwell Verlag GmbH.

Keratitis-associated fungi form biofilms with reduced antifungal drug susceptibility.

PubMed

Zhang, Xiaoyan; Sun, Xuguang; Wang, Zhiqun; Zhang, Yang; Hou, Wenbo

2012-11-21

To investigate the biofilm-forming capacity of Fusarium solani, Cladosporium sphaerospermum, and Acremonium implicatum, and the activities of antifungal agents against the three keratitis-associated fungi. The architecture of biofilms was analyzed using scanning electron microscopy and confocal scanning laser microscopy (CSLM). Susceptibility against six antifungal drugs was measured using the CLSI M38-A method and XTT reduction assay. Time course analyses of CSLM revealed that biofilm formation occurred in an organized fashion through four distinct developmental phases: adhesion, germling formation, microcolony formation, and biofilm maturation. Scanning electron microscopy revealed that mature biofilms displayed a complex three-dimensional structure, consisting of coordinated network of hyphal structures glued by the extracellular matrix (ECM). The antifungal susceptibility testing demonstrated a time-dependent decrease in efficacy for all six antifungal agents as the complexity of fungal hyphal structures developed. Natamycin (NAT), amphotericin B (AMB), and NAT were the most effective against F. solani, C. sphaerospermum, and A. implicatum biofilm, respectively. Corneal isolates of F. solani, C. sphaerospermum, and A. implicatum could produce biofilms that were resistant to antifungal agents in vitro.

In vitro susceptibility of antifungal drugs against Sporothrix brasiliensis recovered from cats with sporotrichosis in Brazil.

PubMed

Brilhante, Raimunda Sâmia Nogueira; Rodrigues, Anderson Messias; Sidrim, José Júlio Costa; Rocha, Marcos Fábio Gadelha; Pereira, Sandro Antonio; Gremião, Isabella Dib Ferreira; Schubach, Tânia Maria Pacheco; de Camargo, Zoilo Pires

2016-03-01

Sporotrichosis is an important subcutaneous mycosis of humans and animals. Classically, the disease is acquired upon traumatic inoculation of Sporothrix propagules from contaminated soil and plant debris. In addition, the direct horizontal transmission of Sporothrix among animals and the resulting zoonotic infection in humans highlight an alternative and efficient rout of transmission through biting and scratching. Sporothrix brasiliensis is the most virulent species of the Sporothrix schenckii complex and is responsible for the long-lasting outbreak of feline sporotrichosis in Brazil. However, antifungal susceptibility data of animal-borne isolates is scarce. Therefore, this study evaluated the in vitro activity of amphotericin B, caspofungin, itraconazole, voriconazole, fluconazole, and ketoconazole against animal-borne isolates of S. brasiliensis. The susceptibility tests were performed through broth microdilution (M38-A2). The results show the relevant activity of itraconazole, amphotericin B, and ketoconazole against S. brasiliensis, with the following MIC ranges: 0.125-2, 0.125-4 and 0.0312-2 μg/ml, respectively. Caspofungin was moderately effective, displaying higher variation in MIC values (0.25-64 μg/ml). Voriconazole (2-64 μg/ml) and fluconazole (62.5-500 μg/ml) showed low activity against S. brasiliensis strains. This study contributed to the characterization of the in vitro antifungal susceptibility of strains of S. brasiliensis recovered from cats with sporotrichosis, which have recently been considered the main source of human infections. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

PubMed

Favalessa, Olivia Cometti; de Paula, Daphine Ariadne Jesus; Dutra, Valeria; Nakazato, Luciano; Tadano, Tomoko; Lazera, Marcia dos Santos; Wanke, Bodo; Trilles, Luciana; Walderez Szeszs, Maria; Silva, Dayane; Hahn, Rosane Christine

2014-08-13

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. 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. 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. 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.

Antifungal Susceptibility Patterns of Opportunistic Fungi in the Genera Verruconis and Ochroconis

PubMed Central

Samerpitak, K.; Rijs, A. J. M. M.; Melchers, W. J. G.; Mouton, J. W.; Verweij, P. E.; de Hoog, G. S.

2014-01-01

Species of Verruconis and species of Ochroconis are dematiaceous fungi generally found in the environment but having the ability to infect humans, dogs, cats, poultry, and fish. This study presents the antifungal susceptibility patterns of these fungi at the species level. Forty strains originating from clinical and environmental sources were phylogenetically identified at the species level by using sequences of the ribosomal DNA internal transcribed spacer (rDNA ITS). In vitro antifungal susceptibility testing was performed against eight antifungals, using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. The geometric mean MICs for amphotericin B (AMB), flucytosine (5FC), fluconazole (FLC), itraconazole (ITC), voriconazole (VRC), and posaconazole (POS) and minimum effective concentrations (MECs) for caspofungin (CAS) and anidulafungin (AFG) across the Ochroconis and Verruconis species were as follows, in increasing order. For Verruconis species, the values (μg/ml) were as follows: AFG, 0.04; POS, 0.25; ITC, 0.37; AMB, 0.50; CAS, 0.65; VRC, 0.96; 5FC, 10.45; and FLC, 47.25. For Ochroconis species, the values (μg/ml) were as follows: AFG, 0.06; POS, 0.11; CAS, 0.67; VRC, 2.76; ITC, 3.94; AMB, 5.68; 5FC, 34.48; and FLC, 61.33. Antifungal susceptibility of Ochroconis and Verruconis was linked with phylogenetic distance and thermotolerance. Echinocandins and POS showed the greatest in vitro activity, providing possible treatment options for Ochroconis and Verruconis infections. PMID:24687495

[Fungi isolated from the vagina and their susceptibility to antifungals].

PubMed

Macura, Anna B; Skóra, Magdalena

2012-06-01

Because of the presence of various fungi and changes in their spectrum in the mycosis of vagina it is necessary to perform periodic overviews including testing their susceptibility to antifungal agents. The objective of the study was to evaluate susceptibility of the fungi isolated from vaginas to antifungal drugs and to analyse the fungi responsible for vaginal mycosis in patients referred during a 7-year study The study was carried out in a group of patients suspected of vaginal mycosis between January 1, 2005 and December 31, 2011. An analysis of the fungi isolated from their vaginas was performed. The susceptibility of the fungi to six antifungals (5-fluorocytosine, amphotericin B, miconazole, ketoconazole, itraconazole and fluconazole) was evaluated using a semiquantitative Fungitest. A total of 4775 mycological test results were evaluated. Fungi were present in 30.6% of the material. C. albicans was the most frequently isolated fungal species (80.2%), followed by C. glabrata (5.8%), and S. cerevisiae (5.5%). Itraconazole turned out to be the least effective drug. C. krusei. was the species most resistant to antifungals, including fluconazole. 1. C. albicans is the species most frequently isolated from a vagina. It is highly susceptible to azoles, the antimycotics generally used in the treatment of vaginal mycosis. 2. Out of the azoles under study ketoconazole was the most active against fungi in vitro while itraconazole was the least active. 3. The Candida non-albicans species, and particularly C. krusei, are less susceptible to antimycotics. 4. Amphotericin B and 5-fluorocytosine are most effective against Candida strains and S. cerevisiae, however they are not used in the treatment of vaginal mycosis because of their high toxicity

In vitro susceptibility of Sporothrix schenckii to six antifungal agents determined using three different methods.

PubMed

Alvarado-Ramírez, Eidi; Torres-Rodríguez, Josep M

2007-07-01

The in vitro susceptibility of Sporothrix schenckii to antifungal drugs has been determined with three different methods. Nineteen Peruvian clinical isolates of S. schenckii were tested against amphotericin B (AB), flucytosine (FC), fluconazole (FZ), itraconazole (IZ), voriconazole (VZ), and ketoconazole (KZ). Modified NCCLS M38-A, Sensititre YeastOne (SYO), and ATB Fungus 2 (ATBF2) methods were used to determine the MICs. ATCC isolates of Candida parapsilosis, Candida krusei, and Aspergillus flavus were used for quality control. Sporothrix inocula were prepared with the mycelial form growing on potato dextrose agar at 28 +/- 2 degrees C. MICs of AB, FC, FZ, and IZ were determined with all three methods, VZ with M38-A and SYO, and KZ with only SYO. The three methods showed high MICs of FZ and FC (MIC(90) of 0.5 microg/ml), being homogeneously lower than those of IZ and KZ. The M38-A method showed a variable MIC range of VZ (4.0 to 16 microg/ml); the geometric mean (GM) was 9.3 mug/ml. The MIC range of AB was wide (0.06 to 16 microg/ml), but the GM was 1.2 microg/ml, suggesting that the MIC is strain dependent. Agreement (two log(2) dilutions) between commercial techniques and the modified M38-A method was very high with FZ, IZ, and FC. In AB and VZ, the agreement was lower, being related to the antifungal concentrations of each method. The highest activity against S. schenckii was found with IZ and KZ. Lack of activity was observed with FZ, VZ, and FC. When AB is indicated for sporotrichosis, the susceptibility of the strain must be analyzed. Commercial quantitative antifungal methods have a limited usefulness in S. schenckii.

[Prevalence of vaginal candidiasis in pregnant women. Identification of yeasts and susceptibility to antifungal agents].

PubMed

García Heredia, M; García, S D; Copolillo, E F; Cora Eliseth, M; Barata, A D; Vay, C A; de Torres, R A; Tiraboschi, N; Famiglietti, A M R

2006-01-01

Pregnant women are more susceptible to both vaginal colonization and infection by yeast. Our objectives were to determine the prevalence in pregnant women of yeasts isolated from vaginal exudates and their susceptibility to current antifungal drugs. A total of 493 patients was studied between December 1998 and February 2000. The prevalence of Candida spp. was 28% (Candida albicans 90.4%; Candida glabrata 6.3%; Candida parapsilosis 1.1%, Candida kefyr 1.1 %; unidentified species 1.1 %). The diffusion test in Shadomy agar was employed to determine the susceptibility to fluconazole, ketoconazole, itraconazole and nistatine. All C. albicans, C. kefyr and C. parapsilosis isolates were susceptible in vitro to the antifungal agents tested, while 1 in 6 C. glabrata isolates showed resistance to azole drugs; all strains were susceptible to nistatine. In pregnant women, C. albicans was the yeast most frequently isolated from vaginal exudates; it continues to be highly susceptible to antifungal drugs. Azole resistance was detected only among C. glabrata isolates. Identification to the species level is recommended, specially in cases of treatment failure and recurrent or chronic infection.

Antifungal susceptibilities of Candida species isolated from the patients with vaginal candidiasis.

PubMed

Nagashima, Masahito; Yamagishi, Yuka; Mikamo, Hiroshige

2016-02-01

There have been the current Japanese data on susceptibility testing for Candida isolates from vaginal candidiasis. The in vitro activities of therapeutic antifungal drugs for vulvovaginal candidiasis (VVC); miconazole (MCZ), itraconazole (ITCZ), fluconazole (FLCZ), clotrimazole (CTZ), oxiconazole (OCZ), isoconazole (ICZ) and bifonazole (BFZ) against vaginal isolates. Fifty-four strains Candida albicans and 19 strains of Candida glabrata were evaluated using a broth microdilution method specified by Clinical Laboratories Standard Institute (CLSI) document M27-A3. The MIC90 of each drug, MCZ, ITCZ, FLCZ, CTZ, OCZ, ICZ and BFZ, against C. albicans and C. glabrata isolates were 0.25, 0.12, 1, 0.06, 0.12, 0.12 and 1 μg/ml and 1, 1, 8, 0.5, 0.25, 0.5 and 1 μg/ml respectively. The activities of these drugs, except for BFZ, against C. glabrata were lower than that of C. albicans. There was one azole-resistant isolate in C. glabrata of which MIC of FLCZ is > 64 μg/ml and this isolate had cross resistance to other antifungal drugs tested. These results suggest that antifungal drugs for treatment of VVC continues to have potent antifungal activities against C. albicans and C. glabrata isolates from vaginitis. CTZ, OCZ and ICZ susceptibility of FLCZ low susceptibility C. glabrata are relatively higher than MCZ, ITCZ and FLCZ. Copyright © 2015. Published by Elsevier Ltd.

Relationships between Respiration and Susceptibility to Azole Antifungals in Candida glabrata

PubMed Central

Brun, Sophie; Aubry, Christophe; Lima, Osana; Filmon, Robert; Bergès, Thierry; Chabasse, Dominique; Bouchara, Jean-Philippe

2003-01-01

Over the past two decades, the incidence of infections due to Candida glabrata, a yeast with intrinsic low susceptibility to azole antifungals, has increased markedly. Respiratory deficiency due to mutations in mitochondrial DNA (mtDNA) associated with resistance to azoles frequently occurs in vitro in this species. In order to specify the relationships between respiration and azole susceptibility, the effects of respiratory chain inhibitors on a wild-type isolate of C. glabrata were evaluated. Respiration of blastoconidia was immediately blocked after extemporaneous addition of potassium cyanide, whereas a 4-h preincubation was required for sodium azide. Antifungal susceptibility determined by a disk diffusion method on Casitone agar containing sodium azide showed a significant decrease in the susceptibility to azoles. Biweekly subculturing on Casitone agar supplemented with sodium azide was therefore performed. This resulted after 40 passages in the isolation of a respiration-deficient mutant, as suggested by its lack of growth on glycerol-containing agar. This respiratory deficiency was confirmed by flow cytometric analysis of blastoconidia stained with rhodamine 123 and by oxygraphy. Moreover, transmission electron microscopy and restriction endonuclease analysis of the mtDNA of mutant cells demonstrated the mitochondrial origin of the respiratory deficiency. Finally, this mutant exhibited cross-resistance to all the azoles tested. In conclusion, blockage of respiration in C. glabrata induces decreased susceptibility to azoles, culminating in azole resistance due to the deletion of mtDNA. This mechanism could explain the induction of petite mutations by azole antifungals which have been demonstrated to act directly on the mitochondrial respiratory chain. PMID:12604511

Candidal colonization, strain diversity, and antifungal susceptibility among adult diabetic patients.

PubMed

Al-Attas, Safia A; Amro, Soliman O

2010-01-01

Candidal colonization in diabetics is a matter of debate. The aim of this study is to investigate oral candidal colonization, strain diversity, antifungal susceptibility, and the influence of local and systemic host factors on candidal colonization in adult diabetics. We conducted a case-control study that compared 150 diabetics (49 type 1, 101 type 2) with 50 healthy controls. Two salivary samples were collected, using the oral rinse sampling method: one for salivary flow rate and pH determination, and the other for candidal colonization assessment. The candidal isolates were identified and tested in vitro for antifungal susceptibility using the commercial kit, Candifast. The relationship between specific host factors and candidal colonization was also investigated. Diabetics had a higher candidal carriage rate compared to controls, but not density. Candida albicans was the most frequently isolated species, but diabetics had a variety of other candidal species present. None of the control samples were resistant to any tested antifungal, while the diabetic samples had differing resistances to azole antifungals. Although there was a significant positive correlation between glycemic control and candidal colonization in type 2 diabetics, there was a negative correlation between salivary pH and candidal carriage in the controls versus density in type 2 diabetics. Diabetic patients not only had a higher candidal carriage rate, but also a variety of candidal species that were resistant to azole antifungals. Oral candidal colonization was significantly associated with glycemic control, type of diabetes, and salivary pH.

Genetic diversity and antifungal susceptibility of Fusarium isolates in onychomycosis.

PubMed

Rosa, Priscila D; Heidrich, Daiane; Corrêa, Carolina; Scroferneker, Maria Lúcia; Vettorato, Gerson; Fuentefria, Alexandre M; Goldani, Luciano Z

2017-09-01

Fusarium species have emerged as an important human pathogen in skin disease, onychomycosis, keratitis and invasive disease. Onychomycosis caused by Fusarium spp. The infection has been increasingly described in the immunocompetent and immunosuppressed hosts. Considering onychomycosis is a difficult to treat infection, and little is known about the genetic variability and susceptibility pattern of Fusarium spp., further studies are necessary to understand the pathogenesis and better to define the appropriate antifungal treatment for this infection. Accordingly, the objective of this study was to describe the in vitro susceptibility to different antifungal agents and the genetic diversity of 35 Fusarium isolated from patients with onychomycosis. Fusarium spp. were isolated predominantly from female Caucasians, and the most frequent anatomical location was the nail of the hallux. Results revealed that 25 (71.4%) of isolates belonged to the Fusarium solani species complex, followed by 10 (28.5%) isolates from the Fusarium oxysporum species complex. Noteworthy, the authors report the first case of Neocosmospora rubicola isolated from a patient with onychomycosis. Amphotericin B was the most effective antifungal agent against the majority of isolates (60%, MIC ≤4 μg/mL), followed by voriconazole (34.2%, MIC ≤4 μg/mL). In general, Fusarium species presented MIC values >64 μg/mL for fluconazole, itraconazole and terbinafine. Accurate pathogen identification, characterisation and susceptibility testing provide a better understanding of pathogenesis of Fusarium in onychomycosis. © 2017 Blackwell Verlag GmbH.

Multilocus phylogeny and antifungal susceptibility of Aspergillus section Circumdati from clinical samples and description of A. pseudosclerotiorum sp. nov.

USDA-ARS?s Scientific Manuscript database

A multilocus phylogenetic study was carried out to assess the species distribution in a set of 34 clinical isolates of Aspergillus section Circumdati from the USA and their in vitro antifungal susceptibility were determined against eight antifungal drugs. The genetic markers used were ITS, BenA, CaM...

In vitro antifungal susceptibility profiles of Cryptococcus species isolated from HIV-associated cryptococcal meningitis patients in Zimbabwe.

PubMed

Nyazika, Tinashe K; Herkert, Patricia F; Hagen, Ferry; Mateveke, Kudzanai; Robertson, Valerie J; Meis, Jacques F

2016-11-01

Cryptococcus neoformans is the leading cause of cryptococcosis in HIV-infected subjects worldwide. Treatment of cryptococcosis is based on amphotericin B, flucytosine, and fluconazole. In Zimbabwe, little is known about antifungal susceptibility of Cryptococcus. Sixty-eight genotyped Cryptococcus isolates were tested for antifungal profiles. Amphotericin B, isavuconazole, and voriconazole showed higher activity than other triazoles. Fluconazole and flucytosine were less effective, with geometric mean MICs of 2.24 and 2.67mg/L for C. neoformans AFLP1/VNI, 1.38 and 1.53mg/L for C. neoformans AFLP1A/VNB/VNII and AFLP1B/VNII, and 1.85 and 0.68mg/L for Cryptococcus tetragattii, respectively. A significant difference between flucytosine geometric mean MICs of C. neoformans and C. tetragattii was observed (P=0.0002). The majority of isolates (n=66/68; 97.1%) had a wild-type MIC phenotype of all antifungal agents. This study demonstrates a favorable situation with respect to the tested antifungals agents. Continued surveillance of antifungal susceptibility profiles is important due to the high burden of cryptococcosis in Africa. Copyright © 2016 Elsevier Inc. All rights reserved.

[In vitro antifungal resistance in Candida albicans from HIV-infected patients with and without oral candidosis.].

PubMed

Ceballos Salobreña, A; Gaitán Cepeda, L A; Orihuela Cañada, F; Olea Barrionuevo, D; Ceballos García, L; Quindós, G

1999-12-01

The main purpose of this study has been to determine the in vitro antifungal susceptibility of clinical isolates from HIV-infected or AIDS patients, depending on the presence of oral candidosis. The oral cavity of 307 HIV-infected or AIDS patients was examined and an oral swab was cultured on Sabouraud glucose agar and studied by conventional mycological methods. In vitro antifungal susceptibility to amphotericin B, nystatin, fluconazole, itraconazole and ketoconazole was tested by disk diffusion with Neo-Sensitabs tablets (Rosco Diagnostica, Dinamarca). One hundred and thirty five Candida albicans isolates (91 serotype A, 38 serotype B, three C. albicans variety stellatoidea and three untyped isolates), three Candida krusei and two Candida glabrata were obtained. All the isolates were susceptible to nystatin and amphotericin B. However, 7.9% isolates were resistant to fluconazole and 2.9% isolates were resistant to ketoconazole or itraconazole. Nearly all C. krusei and C. glabrata isolates, 31% patients with candidosis and 20% Candida-colonized patients showed decreased susceptibility to azoles. This study shows that polyenes had a great in vitro efficacy against clinical isolates from HIV-infected patients and that in vitro resistance to azoles is not as high as observed in other countries.

Candida tropicalis from veterinary and human sources shows similar in vitro hemolytic activity, antifungal biofilm susceptibility and pathogenesis against Caenorhabditis elegans.

PubMed

Brilhante, Raimunda Sâmia Nogueira; Oliveira, Jonathas Sales de; Evangelista, Antônio José de Jesus; Serpa, Rosana; Silva, Aline Lobão da; Aguiar, Felipe Rodrigues Magalhães de; Pereira, Vandbergue Santos; Castelo-Branco, Débora de Souza Collares Maia; Pereira-Neto, Waldemiro Aquino; Cordeiro, Rossana de Aguiar; Sidrim, José Júlio Costa; Rocha, Marcos Fábio Gadelha

2016-08-30

The aim of this study was to evaluate the in vitro hemolytic activity and biofilm antifungal susceptibility of veterinary and human Candida tropicalis strains, as well as their pathogenesis against Caenorhabditis elegans. Twenty veterinary isolates and 20 human clinical isolates of C. tropicalis were used. The strains were evaluated for their hemolytic activity and biofilm production. Biofilm susceptibility to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin was assessed using broth microdilution assay. The in vivo evaluation of strain pathogenicity was investigated using the nematode C. elegans. Hemolytic factor was observed in 95% of the strains and 97.5% of the isolates showed ability to form biofilm. Caspofungin and amphotericin B showed better results than azole antifungals against mature biofilms. Paradoxical effect on mature biofilm metabolic activity was observed at elevated concentrations of caspofungin (8-64μg/mL). Azole antifungals were not able to inhibit mature C. tropicalis biofilms, even at the higher tested concentrations. High mortality rates of C. elegans were observed when the worms were exposed to with C. tropicalis strains, reaching up to 96%, 96h after exposure of the worms to C. tropicalis strains. These results reinforce the high pathogenicity of C. tropicalis from veterinary and human sources and show the effectiveness of caspofungin and amphotericin B against mature biofilms of this species. Copyright © 2016 Elsevier B.V. All rights reserved.

Multicenter surveillance of species distribution and antifungal susceptibilities of Candida bloodstream isolates in South Korea.

PubMed

Jung, Sook-In; Shin, Jong Hee; Song, Jae-Hoon; Peck, Kyong Ran; Lee, Kyungwon; Kim, Mi-Na; Chang, Hyun Ha; Moon, Chi Sook

2010-06-01

Multicenter data on in vitro susceptibility of Candida bloodstream isolates to echinocandin antifungal agents is still lacking in South Korea. We performed a prospective multicenter study to determine the species distribution of Candida bloodstream isolates and their susceptibility to five antifungal agents, including caspofungin and micafungin. A total of 639 isolates were collected from 20 tertiary hospitals between September 2006 and August 2007. Antifungal susceptibilities were determined through the use of the CLSI broth microdilution method M27-A3. The overall species distribution was as follows; Candida albicans (38%), Candida parapsilosis (26%), Candia tropicalis (20%), Candida glabrata (11%), and miscellaneous Candida species (5%). Although C. parapsilosis and miscellaneous Candida species were less susceptible to both echinocandins, all 639 isolates were susceptible to both caspofungin and micafungin (MIC, antifungals, including two echinocandins, are still low among bloodstream isolates in South Korea.

Molecular characterization and antifungal susceptibility testing of Cryptococcus neoformans sensu stricto from southern Brazil.

PubMed

Herkert, Patricia Fernanda; Meis, Jacques F; Lucca de Oliveira Salvador, Gabriel; Rodrigues Gomes, Renata; Aparecida Vicente, Vania; Dominguez Muro, Marisol; Lameira Pinheiro, Rosangela; Lopes Colombo, Arnaldo; Vargas Schwarzbold, Alexandre; Sakuma de Oliveira, Carla; Simão Ferreira, Marcelo; Queiroz-Telles, Flávio; Hagen, Ferry

2018-04-01

Cryptococcosis is acquired from the environment by the inhalation of Cryptococcus cells and may establish from an asymptomatic latent infection into pneumonia or meningoencephalitis. The genetic diversity of a Cryptococcus neoformans species complex has been investigated by several molecular tools, such as multi-locus sequence typing, amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism and microsatellite analysis. This study aimed to investigate the genotype distributions and antifungal susceptibility profiles of C. neoformans sensu lato isolates from southern Brazil. We studied 219 C. neoformans sensu lato isolates with mating- and serotyping, AFLP fingerprinting, microsatellite typing and antifungal susceptibility testing.Results/Key findings. Among the isolates, 136 (69 %) were from HIV-positive patients. Only C. neoformans mating-type α and serotype A were observed. AFLP fingerprinting analysis divided the isolates into AFLP1/VNI (n=172; 78.5 %), AFLP1A/VNII (n=19; 8.7 %), AFLP1B/VNII (n=4; 1.8 %) and a new AFLP pattern AFLP1C (n=23; 10.5 %). All isolates were susceptible to tested antifungals and no correlation between antifungal susceptibility and genotypes was observed. Through microsatellite analysis, most isolates clustered in a major microsatellite complex and Simpson's diversity index of this population was D=0.9856. The majority of C. neoformans sensu stricto infections occurred in HIV-positive patients. C. neoformans AFLP1/VNI was the most frequent genotype and all antifungal drugs had high in vitro activity against this species. Microsatellite analyses showed a high genetic diversity within the regional C. neoformans sensu stricto population, and correlation between environmental and clinical isolates, as well as a temporal and geographic relationship.

Antifungal susceptibilities of Candida species isolated from urine culture.

PubMed

Toka Özer, Türkan; Durmaz, Süleyman; Yula, Erkan

2016-09-01

Candida spp. are the most common opportunistic mycosis worldwide. Although Candida albicans is the most common cause of urinary tract infections, the frequency of non-albicans Candida species is increasing with common use of antifungal in the prophylaxis and treatment. This may lead to difficulties in treatment. Antifungal tests should be applied with identification of species for effective treatment. In this study, identification of Candida species isolated from urine culture and investigation of susceptibility of these strains to amphotericin B, flucytosine, fluconazole, voriconazole was aimed. In this study, 58 Candida strains isolated from urine cultures at Osmaniye State Hospital between January 2012 and April 2013 were included. Urine culture and antifungal susceptibility tests were applied. Incidence rate of Candida spp. was determined as C. albicans (56.9%), Candida glabrata (20.6%), Candida tropicalis (10.3%), Candida parapsilosis (7%), Candida krusei (3.4%), Candida kefyr (1.8%). Most of the isolates were susceptible to amphotericin B, flucytosine, fluconazole, voriconazole. Twenty three (39.7%) Candida strains were isolated from internal medical branches and Intensive Care Unit and 12 (20.6%) from the Surgical Medical Branches. C. albicans and C. glabrata species were isolated most frequently as a candiduria factor in this hospital between January 2012 and April 2013. The analysis of antifungal susceptibility profile shows no significant resistance to antifungals. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

[In vitro activity of voriconazole and three other antifungal agents against dermatophytes].

PubMed

Serrano-Martino, María del Carmen; Chávez-Caballero, Mónica; Valverde-Conde, Anastasio; Claro, Rosa María; Pemán, Javier; Martín-Mazuelos, Estrella

2003-11-01

The increase in infections due to dermatophytes in recent years led us to study the effectiveness of new antifungal formulations against these microorganisms. The in vitro activity of a new antifungal agent, voriconazole, was compared with three other antifungal agents, itraconazole, fluconazole and terbinafine, against 120 dermatophytes belonging to four species (61 Trichophyton mentagrophytes, 34 Microsporum canis, 13 M. gypseum and 12 T. rubrum). A broth microdilution method was used following the recommendations of the NCCLS document M38-P with some modifications. Terbinafine was the most active agent against the dermatophytes studied (MIC90 < or = 0.03 mg/ml), followed by voriconazole (MIC90, 0.25 micro g/ml) and itraconazole (MIC90, 0.5 micro g/ml). Fluconazole was the least active antifungal agent. The most susceptible species was M. canis. Voriconazole was found to have effective activity against dermatophytes.

Invasive candidiasis in intensive care units in China: in vitro antifungal susceptibility in the China-SCAN study.

PubMed

Liu, Wei; Tan, Jingwen; Sun, Jimei; Xu, Zhijiang; Li, Min; Yang, Qing; Shao, Haifeng; Zhang, Liyan; Liu, Weixia; Wan, Zhe; Cui, Wei; Zang, Bin; Jiang, Dongpo; Fang, Qiang; Qin, Bingyu; Qin, Tiehe; Li, Weiqin; Guo, Fengmei; Liu, Dawei; Guan, Xiandong; Yu, Kaijiang; Qiu, Haibo; Li, Ruoyu

2014-01-01

The objectives of this study were to determine species distribution and in vitro antifungal susceptibility of Candida isolates identified in the multicentre China-SCAN study of invasive Candida infection (ICI) in intensive care units (ICUs) across China. Candida isolates from patients in the China-SCAN study with documented ICI were evaluated by a central laboratory. Species were identified using chromogenic culture media or the API 20C AUX kit. Susceptibility to fluconazole, voriconazole, itraconazole, caspofungin and amphotericin B was determined using the CLSI broth microdilution method (M27-A3) and updated clinical breakpoints or epidemiological cut-off values. A total of 389 isolates from 244 patients were analysed. Species identified most frequently were Candida albicans (40.1%), Candida parapsilosis (21.3%), Candida tropicalis (17.2%) and Candida glabrata (12.9%). Rarer species such as Lodderomyces elongisporus and Candida ernobii were also identified. Fluconazole susceptibility was evident in 85.9% (134/156) of C. albicans, 62.7% (42/67) of C. tropicalis and 48.2% (40/83) of C. parapsilosis isolates. Susceptibility to voriconazole was ≥ 90% among all species. All isolates were susceptible to amphotericin B and caspofungin except C. glabrata [86.0% (43/50) susceptible to caspofungin]. Cross-resistance between fluconazole and voriconazole was observed for C. parapsilosis and C. glabrata. Although C. albicans was the predominant single species, non-albicans species constituted >50% of isolates. Fluconazole susceptibility was lower in most non-albicans species, indicating that fluconazole resistance should be closely monitored. Susceptibility to voriconazole, amphotericin B and caspofungin is encouraging. Differences between these data and those from other regions emphasize the importance of assessing regional variations.

Molecular epidemiology and in vitro antifungal susceptibility testing of 108 clinical Cryptococcus neoformans sensu lato and Cryptococcus gattii sensu lato isolates from Denmark.

PubMed

Hagen, Ferry; Hare Jensen, Rasmus; Meis, Jacques F; Arendrup, Maiken Cavling

2016-09-01

Cryptococcosis is mainly caused by members of the Cryptococcus gattii/Cryptococcus neoformans species complexes. Here, we report the molecular characterisation and in vitro antifungal susceptibility of Danish clinical cryptococcal isolates. Species, genotype, serotype and mating type were determined by amplified fragment length polymorphism (AFLP) fingerprinting and qPCR. EUCAST E.Def 7.2 MICs were determined for amphotericin B, flucytosine, fluconazole, voriconazole and isavuconazole. Most isolates were C. neoformans (serotype A; n = 66) and belonged to genotype AFLP1/VNI (n = 61) or AFLP1B/VNII (n = 5) followed by Cryptococcus deneoformans (serotype D; genotype AFLP2, n = 20), C. neoformans × C. deneoformans hybrids (serotype AD; genotype AFLP3, n = 13) and Cryptococcus curvatus (n = 2). Six isolates were C. gattii sensu lato, and one isolate was a C. deneoformans × C. gattii hybrid (genotype AFLP8). All isolates were amphotericin B susceptible. Flucytosine susceptibility was uniform MIC50 of 4-8 mg l(-1) except for C. curvatus (MICs >32 mg l(-1) ). Cryptococcus gattii sensu lato isolates were somewhat less susceptible to the azoles. MICs of fluconazole (>32 mg l(-1) ), voriconazole (≥0.5 mg l(-1) ) and isavuconazole (0.06 and 0.25 mg l(-1) respectively) were elevated compared to the wild-type population for 1/19 C. deneoformans and 1/2 C. curvatus isolates. Flucytosine MIC was elevated for 1/61 C. neoformans (>32 mg l(-1) ). Antifungal susceptibility revealed species-specific differential susceptibility, but suggested acquired resistance was an infrequent phenomenon. © 2016 Blackwell Verlag GmbH.

In view of an optimal gut antifungal therapeutic strategy: an in vitro susceptibility and toxicity study testing a novel phyto-compound.

PubMed

Metugriachuk, Yussef; Kuroi, Olivia; Pavasuthipaisit, Kanok; Tsuchiya, Junji; Minelli, Emilio; Okura, Ruichi; Fesce, Edoardo; Marotta, F

2005-01-01

In view of the raising concern for gut fungal infection, the aim of the present research was to carry out a systematic in vitro study testing the antifungal activity and possible toxicity of a polygodyal-anethole compound (Kolorex) in several strains of Candida albicans and in other fungal pathogens. The in vitro susceptibility tests were carried out on 4 strains of C. albicans (C. krusei, C. lipolytica, C. tropicalis, C. utilis), Aspergillus flavus and A. fumigatus. Cultures were also analyzed by varying medium, pH and inoculum size, and a time-course killing test was carried out. In the present study the polygodyal-anethole compound showed remarkable in vitro activity against the most common fungi, which was significantly better than polygodyal alone. Moreover, such mixture compound was shown to exert its activity against a wide spectrum of fungi, including C. lipolytica and C. tropicalis, which required significantly higher MIC of polygodyal to be unfeasible in clinical application. The activity of the polygodyal-anethole compound was significantly better than polygodyal alone with high inoculum size and low pH. Moreover, it proved to exert a significantly faster biological activity against low inoculum. This study suggests that the mixture compound Kolorex has a very good profile of antifungal activity in terms of effectiveness and spectrum of action while being devoid of any significant toxicity.

Determination of antifungal susceptibility patterns among the environmental isolates of Aspergillus fumigatus in Iran

PubMed Central

Mohammadi, Faezeh; Dehghan, Parvin; Nekoeian, Shahram; Hashemi, Seyed Jamal

2016-01-01

Background: In recent years, triazole-resistant environmental isolates of Aspergillus fumigatus have emerged in Europe and Asia. Azole resistance has been reported in patients who are treated with long-term azole therapy or exposure of the fungus spores to the azole fungicides used in agriculture. To date, a wide range of mutations in A. fumigatus have been described conferring azole-resistance, which commonly involves modifications in the cyp51A gene. We investigated antifungal susceptibility pattern of environmental isolates of A. fumigatus. Materials and Methods: In this study, 170 environmental samples collected from indoors surfaces of three hospitals in Iran. It was used β-tubulin gene to confirm the all of A. fumigatus isolates, which was identified by conventional methods. Furthermore, the antifungal susceptibility of itraconazole, voriconazole, and posaconazole was investigated using broth microdilution test, according to European Committee on Antimicrobial Susceptibility testing reference method. Results: From a total of 158 environmental molds fungi obtained from the hospitals, 58 isolates were identified as A. fumigatus by amplification of expected size of β-tubulin gene (~500 bp). In this study, in vitro antifungal susceptibility testing has shown that there were not high minimum inhibitory concentration values of triazole antifungals in all of the 58 environmental isolates of A. fumigatus. Conclusion: Our findings demonstrated that there was not azole-resistant among environmental isolates of A. fumigatus. Medical triazoles compounds have structural similarity with triazole fungicide compounds in agriculture, therefore, resistance development through exposure to triazole fungicide compounds in the environment is important but it sounds there is not a serious health problem in drug resistance in environmental isolates in Iran. PMID:27656605

Aspergillus--classification and antifungal susceptibilities.

PubMed

Buzina, Walter

2013-01-01

Aspergillus is one of the most important fungal genera for the man, for its industrial use, its ability to spoil food and not least its medical impact as cause of a variety of diseases. Currently hundreds of species of Aspergillus are known; nearly fifty of them are able to cause infections in humans and animals. Recently, the genus Aspergillus is subdivided into 8 subgenera and 22 sections. The spectrum of diseases caused by Aspergillus species varies from superficial cutaneous to invasive and systemic infections. All species of Aspergillus investigated so far are resistant against the antifungals fluconazole and 5-fluorocytosine, the range of susceptibilities to currently available antifungals is discussed in this paper.

Etest Cannot Be Recommended for In Vitro Susceptibility Testing of Mucorales

PubMed Central

Caramalho, Rita; Maurer, Elisabeth; Binder, Ulrike; Araújo, Ricardo; Dolatabadi, Somayeh; Lass-Flörl, Cornelia

2015-01-01

Amphotericin B and posaconazole susceptibility patterns were determined for the most prevalent Mucorales, following EUCAST (European Committee on Antimicrobial Susceptibility Testing) broth microdilution guidelines. In parallel, Etest was performed and evaluated against EUCAST. The overall agreement of MICs gained with Etest and EUCAST was 75.1%; therefore, Etest cannot be recommended for antifungal susceptibility testing of Mucorales. Amphotericin B was the most active drug against Mucorales species in vitro, while the activities of posaconazole were more restricted. PMID:25845881

Antifungal susceptibility of 175 Aspergillus isolates from various clinical and environmental sources.

PubMed

Sabino, Raquel; Carolino, Elisabete; Veríssimo, Cristina; Martinez, Marife; Clemons, Karl V; Stevens, David A

2016-10-01

Some environmental Aspergillus spp. isolates have been described as resistant to antifungals, potentially causing an emerging medical problem. In the present work, the antifungal susceptibility profile of 41 clinical and 134 environmental isolates of Aspergillus was determined using the CLSI microdilution method. The aim of this study was to compare environmental and clinical isolates with respect to their susceptibility, and assess the potential implications for therapy of isolates encountered in different environments. To our knowledge, this is the first report comparing antifungal susceptibility profiles of Aspergillus collected from different environmental sources (poultries, swineries, beach sand, and hospital environment). Significant differences were found in the distribution of the different species sections for the different sources. Significant differences were also found in the susceptibility profile of the different Aspergillus sections recovered from the various sources. Clear differences were found between the susceptibility of clinical and environmental isolates for caspofungin, amphotericin B and posaconazole, with clinical isolates showing overall greater susceptibility, except for caspofungin. In comparison to clinical isolates, hospital environmental isolates showed significantly less susceptibility to amphotericin B and posaconazole. These data indicate that species section identity and the site from which the isolate was recovered influence the antifungal susceptibility profile, which may affect initial antifungal choices. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Antifungal resistance in mucorales.

PubMed

Dannaoui, E

2017-11-01

The order Mucorales, which includes the agents of mucormycosis, comprises a large number of species. These fungi are characterised by high-level resistance to most currently available antifungal drugs. Standardised antifungal susceptibility testing methods are now available, allowing a better understanding of the in vitro activity of antifungal drugs against members of Mucorales. Such tests have made apparent that antifungal susceptibility within this group may be species-specific. Experimental animal models of mucormycosis have also been developed and are of great importance in bridging the gap between in vitro results and clinical trials. Amphotericin B, posaconazole and isavuconazole are currently the most active agents against Mucorales; however, their activity remains suboptimal and new therapeutic strategies are needed. Combination therapy could be a promising approach to overcome resistance, but further studies are required to confirm its benefits and safety for patients. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

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

PubMed Central

de Oliveira, Jean Carlos Almeida

2017-01-01

Candida glabrata is 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 of C. glabrata. All C. glabrata strains 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. glabrata strains 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 the C. glabrata mechanisms 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 of C. glabrata infections. PMID:28814823

In Vitro Antifungal Susceptibility Testing of Candida Isolates with the EUCAST Methodology, a New Method for ECOFF Determination.

PubMed

Meletiadis, J; Curfs-Breuker, I; Meis, J F; Mouton, J W

2017-04-01

The in vitro susceptibilities of 1,099 molecularly identified clinical Candida isolates against 8 antifungal drugs were determined using the EUCAST microdilution method. A new simple, objective, and mathematically solid method for determining epidemiological cutoff values (ECOFFs) was developed by derivatizing the MIC distribution and determining the derivatized ECOFF (dECOFF) as the highest MIC with the maximum second derivative. The dECOFFs were similar (95% agreement within 1 dilution) to the EUCAST ECOFFs. Overall, low non-wild-type/resistance rates were found. The highest rates were found for azoles with C. parapsilosis (2.7 to 9.8%), C. albicans (7%), and C. glabrata (1.7 to 2.3%) and for echinocandins with C. krusei (3.3%), C. albicans (1%), and C. tropicalis (1.7%). Copyright © 2017 American Society for Microbiology.

In Vitro and In Vivo Activity of a Novel Antifungal Small Molecule against Candida Infections

PubMed Central

Yuen, Kwok Yong; Wang, Yu; Yang, Dan; Samaranayake, Lakshman Perera

2014-01-01

Candida is the most common fungal pathogen of humans worldwide and has become a major clinical problem because of the growing number of immunocompromised patients, who are susceptible to infection. Moreover, the number of available antifungals is limited, and antifungal-resistant Candida strains are emerging. New and effective antifungals are therefore urgently needed. Here, we discovered a small molecule with activity against Candida spp. both in vitro and in vivo. We screened a library of 50,240 small molecules for inhibitors of yeast-to-hypha transition, a major virulence attribute of Candida albicans. This screening identified 20 active compounds. Further examination of the in vitro antifungal and anti-biofilm properties of these compounds, using a range of Candida spp., led to the discovery of SM21, a highly potent antifungal molecule (minimum inhibitory concentration (MIC) 0.2 – 1.6 µg/ml). In vitro, SM21 was toxic to fungi but not to various human cell lines or bacterial species and was active against Candida isolates that are resistant to existing antifungal agents. Moreover, SM21 was relatively more effective against biofilms of Candida spp. than the current antifungal agents. In vivo, SM21 prevented the death of mice in a systemic candidiasis model and was also more effective than the common antifungal nystatin at reducing the extent of tongue lesions in a mouse model of oral candidiasis. Propidium iodide uptake assay showed that SM21 affected the integrity of the cell membrane. Taken together, our results indicate that SM21 has the potential to be developed as a novel antifungal agent for clinical use. PMID:24465737

Species-specific antifungal susceptibility patterns of Scedosporium and Pseudallescheria species.

PubMed

Lackner, Michaela; de Hoog, G Sybren; Verweij, Paul E; Najafzadeh, Mohammad J; Curfs-Breuker, Ilse; Klaassen, Corné H; Meis, Jacques F

2012-05-01

Since the separation of Pseudallescheria boydii and P. apiosperma in 2010, limited data on species-specific susceptibility patterns of these and other species of Pseudallescheria and its anamorph Scedosporium have been reported. This study presents the antifungal susceptibility patterns of members affiliated with both entities. Clinical and environmental isolates (n = 332) from a wide range of sources and origins were identified down to species level and tested according to CLSI M38-A2 against eight antifungal compounds. Whereas P. apiosperma (geometric mean MIC/minimal effective concentration [MEC] values of 0.9, 2.4, 7.4, 16.2, 0.2, 0.8, 1.5, and 6.8 μg/ml for voriconazole, posaconazole, isavuconazole, itraconazole, micafungin, anidulafungin, caspofungin, and amphotericin B, respectively) and P. boydii (geometric mean MIC/MEC values of 0.7, 1.3, 5.7, 13.8, 0.5, 1.4, 2.3, and 11.8 μg/ml for voriconazole, posaconazole, isavuconazole, itraconazole, micafungin, anidulafungin, caspofungin, and amphotericin B, respectively) had similar susceptibility patterns, those for S. aurantiacum, S. prolificans, and S. dehoogii were different from each other. Voriconazole was the only drug with significant activity against S. aurantiacum isolates. The MIC distributions of all drugs except voriconazole did not show a normal distribution and often showed two subpopulations, making a species-based prediction of antifungal susceptibility difficult. Therefore, antifungal susceptibility testing of all clinical isolates remains essential for targeted antifungal therapy. Voriconazole was the only compound with low MIC values (MIC(90) of ≤ 2 μg/ml) for P. apiosperma and P. boydii. Micafungin and posaconazole showed moderate activity against the majority of Scedosporium strains.

Species-Specific Antifungal Susceptibility Patterns of Scedosporium and Pseudallescheria Species

PubMed Central

Lackner, Michaela; de Hoog, G. Sybren; Verweij, Paul E.; Najafzadeh, Mohammad J.; Curfs-Breuker, Ilse; Klaassen, Corné H.

2012-01-01

Since the separation of Pseudallescheria boydii and P. apiosperma in 2010, limited data on species-specific susceptibility patterns of these and other species of Pseudallescheria and its anamorph Scedosporium have been reported. This study presents the antifungal susceptibility patterns of members affiliated with both entities. Clinical and environmental isolates (n = 332) from a wide range of sources and origins were identified down to species level and tested according to CLSI M38-A2 against eight antifungal compounds. Whereas P. apiosperma (geometric mean MIC/minimal effective concentration [MEC] values of 0.9, 2.4, 7.4, 16.2, 0.2, 0.8, 1.5, and 6.8 μg/ml for voriconazole, posaconazole, isavuconazole, itraconazole, micafungin, anidulafungin, caspofungin, and amphotericin B, respectively) and P. boydii (geometric mean MIC/MEC values of 0.7, 1.3, 5.7, 13.8, 0.5, 1.4, 2.3, and 11.8 μg/ml for voriconazole, posaconazole, isavuconazole, itraconazole, micafungin, anidulafungin, caspofungin, and amphotericin B, respectively) had similar susceptibility patterns, those for S. aurantiacum, S. prolificans, and S. dehoogii were different from each other. Voriconazole was the only drug with significant activity against S. aurantiacum isolates. The MIC distributions of all drugs except voriconazole did not show a normal distribution and often showed two subpopulations, making a species-based prediction of antifungal susceptibility difficult. Therefore, antifungal susceptibility testing of all clinical isolates remains essential for targeted antifungal therapy. Voriconazole was the only compound with low MIC values (MIC90 of ≤2 μg/ml) for P. apiosperma and P. boydii. Micafungin and posaconazole showed moderate activity against the majority of Scedosporium strains. PMID:22290955

In vitro antifungal susceptibility and molecular identity of 99 clinical isolates of the opportunistic fungal genus Curvularia.

PubMed

da Cunha, Keith C; Sutton, Deanna A; Fothergill, Annette W; Gené, Josepa; Cano, Josep; Madrid, Hugo; Hoog, Sybren de; Crous, Pedro W; Guarro, Josep

2013-06-01

The in vitro antifungal susceptibility of a set of 99 clinical isolates of Curvularia was tested against 9 drugs using a reference microdilution method. The isolates had been identified previously to species level by comparing their ITS rDNA and glyceraldehyde-3-phosphate dehydrogenase gene sequences with those of reference strains. We were able to reliably identify 73.2% of the isolates, the most frequent species being Curvularia aeria, Curvularia geniculata/Curvularia senegalensis, Curvularia lunata, Curvularia inaequalis, Curvularia verruculosa, and Curvularia borreriae. Most of these isolates had been recovered from nasal sinus, which is generally considered one of the most frequent sites of infection by these fungi. In addition, at least 3 phylogenetic species that have not yet been formally described were detected. The most active drugs were the echinocandins, amphotericin B, and posaconazole, whereas voriconazole and itraconazole showed poor activity. Copyright © 2013 Elsevier Inc. All rights reserved.

Infection and colonisation due to Scedosporium in Northern Spain. An in vitro antifungal susceptibility and molecular epidemiology study of 60 isolates.

PubMed

Lackner, M; Rezusta, A; Villuendas, M C; Palacian, M P; Meis, J F; Klaassen, C H

2011-10-01

Since the latest taxonomical changes in the genus Scedosporium by Gilgado et al. in 2010, no species-specific studies on epidemiology and antifungal susceptibility patterns (AFSP) have so far been published. This study aimed to provide qualitative epidemiological data of Scedosporium spp. isolated from cystic fibrosis (CF) patients and immunocompromised patients from Northern Spain. Isolates were identified by using amplified fragment length polymorphism (AFLP), and species-specific AFSP were generated for all currently available antifungal compounds. AFLP was a useful tool for identification to species-level and for the discrimination of inter- and intra-patient isolates. Scedosporium prolificans represents the most prevalent species in the respiratory tract of CF patients and immunocompromised patients in Northern-Spain, followed by Pseudallescheria boydii, P. apiosperma, and P. ellipsoidea. CF patients were exclusively colonised with either P. boydii or S. prolificans. Patients were colonised over years exclusively with isolates affiliated to one species, but some patients were colonised with multiple strains with different AFSP. The sum of those co-colonising strains in one patient, may appear in vitro and in vivo as a multi-resistant S. prolificans isolate, as strains are morphologically identical and might therefore be regarded as only one strain. A majority of Scedosporium strains (with exception of S. prolificans) were found susceptible for voriconazole and micafungin. © 2011 Blackwell Verlag GmbH.

Etest cannot be recommended for in vitro susceptibility testing of mucorales.

PubMed

Caramalho, Rita; Maurer, Elisabeth; Binder, Ulrike; Araújo, Ricardo; Dolatabadi, Somayeh; Lass-Flörl, Cornelia; Lackner, Michaela

2015-01-01

Amphotericin B and posaconazole susceptibility patterns were determined for the most prevalent Mucorales, following EUCAST (European Committee on Antimicrobial Susceptibility Testing) broth microdilution guidelines. In parallel, Etest was performed and evaluated against EUCAST. The overall agreement of MICs gained with Etest and EUCAST was 75.1%; therefore, Etest cannot be recommended for antifungal susceptibility testing of Mucorales. Amphotericin B was the most active drug against Mucorales species in vitro, while the activities of posaconazole were more restricted. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

In vitro antifungal activity of silver nanoparticles against ocular pathogenic filamentous fungi.

PubMed

Xu, Yan; Gao, Chuanwen; Li, Xiaohua; He, Yi; Zhou, Lutan; Pang, Guangren; Sun, Shengtao

2013-03-01

Fungal keratitis is emerging as a major cause of vision loss in a developing country such as China because of higher incidence and the unavailability of effective antifungals. It is urgent to explore broad-spectrum antifungals to effectively suppress ocular fungal pathogens, and to develop new antifungal eye drops to combat this vision-threatening infection. The aim of this study is to investigate the antifungal activity of silver nanoparticles (nano-Ag) in comparison with that of natamycin against ocular pathogenic filamentous fungi in vitro. Susceptibility tests were performed against 216 strains of fungi isolated from patients with fungal keratitis from the Henan Eye Institute in China by broth dilution antifungal susceptibility test of filamentous fungi approved by the Clinical and Laboratory Standards Institute M38-A document. The isolates included 112 Fusarium isolates (82 Fusarium solani species complex, 20 Fusarium verticillioides species complex, and 10 Fusarium oxysporum species complex), 94 Aspergillus isolates (61 Aspergillus flavus species complex, 11 Aspergillus fumigatus species complex, 12 Aspergillus versicolor species complex, and 10 Aspergillus niger species complex), and 10 Alternaria alternata isolates. The minimum inhibitory concentration (MIC) range and mode, the MIC for 50% of the strains tested (MIC50 value), and the MIC90 value were provided for the isolates with the SPSS statistical package. MIC50 value of nano-Ag were 1, 0.5, and 0.5 μg/mL for Fusarium spp., Aspergillus spp., and Al. alternata, respectively. MIC90 values of nano-Ag were 1, 1, and 1 μg/mL for Fusarium spp., Aspergillus spp., and Al. alternata, respectively. MIC50 values of natamycin were 4, 32, and 4 μg/mL for Fusarium spp., Aspergillus spp., and Al. alternata, respectively. MIC90 values of natamycin were 8, 32, and 4 μg/mL for Fusarium spp., Aspergillus spp., and Al. alternata, respectively. Nano-Ag, relative to natamycin, exhibits potent in vitro activity against

Time-Kill Kinetics and In Vitro Antifungal Susceptibility of Non-fumigatus Aspergillus Species Isolated from Patients with Ocular Mycoses.

PubMed

Öz, Yasemin; Özdemir, Havva Gül; Gökbolat, Egemen; Kiraz, Nuri; Ilkit, Macit; Seyedmousavi, Seyedmojtaba

2016-04-01

Aspergillus species can cause ocular morbidity and blindness, and thus, appropriate antifungal therapy is needed. We investigated the in vitro activity of itraconazole, voriconazole, posaconazole, caspofungin, anidulafungin, and amphotericin B against 14 Aspergillus isolates obtained from patients with ocular mycoses, using the CLSI reference broth microdilution methodology. In addition, time-kill assays were performed, exposing each isolate separately to 1-, 4-, and 16-fold concentrations above the minimum inhibitory concentration (MIC) of each antifungal agent. A sigmoid maximum-effect (E max) model was used to fit the time-kill curve data. The drug effect was further evaluated by measuring an increase/decrease in the killing rate of the tested isolates. The MICs of amphotericin B, itraconazole, voriconazole, and posaconazole were 0.5-1.0, 1.0, 0.5-1.0, and 0.25 µg/ml for A. brasiliensis, A. niger, and A. tubingensis isolates, respectively, and 2.0-4.0, 0.5, 1.0 for A. flavus, and 0.12-0.25 µg/ml for A. nomius isolates, respectively. A. calidoustus had the highest MIC range for the azoles (4.0-16.0 µg/ml) among all isolates tested. The minimum effective concentrations of caspofungin and anidulafungin were ≤0.03-0.5 µg/ml and ≤0.03 µg/ml for all isolates, respectively. Posaconazole demonstrated maximal killing rates (E(max) = 0.63 h(-1), r(2) = 0.71) against 14 ocular Aspergillus isolates, followed by amphotericin B (E(max) = 0.39 h(-1), r(2) = 0.87), voriconazole (E(max) = 0.35 h(-1), r(2) = 0.098), and itraconazole (E(max) = 0.01 h(-1), r(2) = 0.98). Overall, the antifungal susceptibility of the non-fumigatus Aspergillus isolates tested was species and antifungal agent dependent. Analysis of the kinetic growth assays, along with consideration of the killing rates, revealed that posaconazole was the most effective antifungal against all of the isolates.

In vitro susceptibility of Scedosporium isolates to N-acetyl-L-cysteine alone and in combination with conventional antifungal agents.

PubMed

Homa, Mónika; Galgóczy, László; Tóth, Eszter; Virágh, Máté; Chandrasekaran, Muthusamy; Vágvölgyi, Csaba; Papp, Tamás

2016-10-01

In recent years, Scedosporium species have been more commonly recognized from severe, difficult-to-treat human infections, such as upper respiratory tract and pulmonary infections. To select an appropriate therapeutic approach for these infections is challenging, because of the commonly observed resistance of the causative agents to several antifungal drugs. Therefore, to find a novel strategy for the treatment of pulmonary Scedosporium infections the in vitro antifungal effect of a mucolytic agent, N-acetyl-L-cysteine and its in vitro combinations with conventional antifungals were investigated. Synergistic and indifferent interactions were registered in 23 and 13 cases, respectively. Antagonism was not revealed between the compounds. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Methodological Issues in Antifungal Susceptibility Testing of Malassezia pachydermatis

PubMed Central

Peano, Andrea; Pasquetti, Mario; Tizzani, Paolo; Chiavassa, Elisa; Guillot, Jacques; Johnson, Elizabeth

2017-01-01

Reference methods for antifungal susceptibility testing of yeasts have been developed by the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antibiotic Susceptibility Testing (EUCAST). These methods are intended to test the main pathogenic yeasts that cause invasive infections, namely Candida spp. and Cryptococcus neoformans, while testing other yeast species introduces several additional problems in standardization not addressed by these reference procedures. As a consequence, a number of procedures have been employed in the literature to test the antifungal susceptibility of Malassezia pachydermatis. This has resulted in conflicting results. The aim of the present study is to review the procedures and the technical parameters (growth media, inoculum preparation, temperature and length of incubation, method of reading) employed for susceptibility testing of M. pachydermatis, and when possible, to propose recommendations for or against their use. Such information may be useful for the future development of a reference assay. PMID:29371554

Correlation between In Vitro and In Vivo Antifungal Activities in Experimental Fluconazole-Resistant Oropharyngeal and Esophageal Candidiasis

PubMed Central

Walsh, Thomas J.; Gonzalez, Corina E.; Piscitelli, Steven; Bacher, John D.; Peter, Joanne; Torres, Richard; Shetti, Daiva; Katsov, Victoria; Kligys, Kristina; Lyman, Caron A.

2000-01-01

Oropharyngeal and esophageal candidiasis (OPEC) is a frequent opportunistic mycosis in immunocompromised patients. Azole-resistant OPEC is a refractory form of this infection occurring particularly in human immunodeficiency virus (HIV)-infected patients. The procedures developed by the Antifungal Subcommittee of the National Committee for Clinical Laboratory Standards (NCCLS) are an important advance in standardization of in vitro antifungal susceptibility methodology. In order to further understand the relationship between NCCLS methodology and antifungal therapeutic response, we studied the potential correlation between in vitro susceptibility to fluconazole and in vivo response in a rabbit model of fluconazole-resistant OPEC. MICs of fluconazole were determined by NCCLS methods. Three fluconazole-susceptible (FS) (MIC, ≤0.125 μg/ml) and three fluconazole-resistant (FR) (MIC, ≥64 μg/ml) isolates of Candida albicans from prospectively monitored HIV-infected children with OPEC were studied. FR isolates were recovered from children with severe OPEC refractory to fluconazole, and FS isolates were recovered from those with mucosal candidiasis responsive to fluconazole. Fluconazole at 2 mg/kg of body weight/day was administered to infected animals for 7 days. The concentrations of fluconazole in plasma were maintained above the MICs for FS isolates throughout the dosing interval. Fluconazole concentrations in the esophagus were greater than or equal to those in plasma. Rabbits infected with FS isolates and treated with fluconazole had significant reductions in oral mucosal quantitative cultures (P < 0.001) and tissue burden of C. albicans in tongue, soft palate, and esophagus (P < 0.001). In comparison, rabbits infected with FR isolates were unresponsive to fluconazole and had no reduction in oral mucosal quantitative cultures or tissue burden of C. albicans versus untreated controls. We conclude that there is a strong correlation between in vitro fluconazole

Correlation between in vitro and in vivo antifungal activities in experimental fluconazole-resistant oropharyngeal and esophageal candidiasis.

PubMed

Walsh, T J; Gonzalez, C E; Piscitelli, S; Bacher, J D; Peter, J; Torres, R; Shetti, D; Katsov, V; Kligys, K; Lyman, C A

2000-06-01

Oropharyngeal and esophageal candidiasis (OPEC) is a frequent opportunistic mycosis in immunocompromised patients. Azole-resistant OPEC is a refractory form of this infection occurring particularly in human immunodeficiency virus (HIV)-infected patients. The procedures developed by the Antifungal Subcommittee of the National Committee for Clinical Laboratory Standards (NCCLS) are an important advance in standardization of in vitro antifungal susceptibility methodology. In order to further understand the relationship between NCCLS methodology and antifungal therapeutic response, we studied the potential correlation between in vitro susceptibility to fluconazole and in vivo response in a rabbit model of fluconazole-resistant OPEC. MICs of fluconazole were determined by NCCLS methods. Three fluconazole-susceptible (FS) (MIC, /=64 microgram/ml) isolates of Candida albicans from prospectively monitored HIV-infected children with OPEC were studied. FR isolates were recovered from children with severe OPEC refractory to fluconazole, and FS isolates were recovered from those with mucosal candidiasis responsive to fluconazole. Fluconazole at 2 mg/kg of body weight/day was administered to infected animals for 7 days. The concentrations of fluconazole in plasma were maintained above the MICs for FS isolates throughout the dosing interval. Fluconazole concentrations in the esophagus were greater than or equal to those in plasma. Rabbits infected with FS isolates and treated with fluconazole had significant reductions in oral mucosal quantitative cultures (P < 0.001) and tissue burden of C. albicans in tongue, soft palate, and esophagus (P < 0.001). In comparison, rabbits infected with FR isolates were unresponsive to fluconazole and had no reduction in oral mucosal quantitative cultures or tissue burden of C. albicans versus untreated controls. We conclude that there is a strong correlation between in vitro

Species Identification and In Vitro Antifungal Susceptibility of Aspergillus terreus Species Complex Clinical Isolates from a French Multicenter Study.

PubMed

Imbert, S; Normand, A C; Ranque, S; Costa, J M; Guitard, J; Accoceberry, I; Bonnal, C; Fekkar, A; Bourgeois, N; Houzé, S; Hennequin, C; Piarroux, R; Dannaoui, E; Botterel, F

2018-05-01

Aspergillus section Terrei is a species complex currently comprised of 14 cryptic species whose prevalence in clinical samples as well as antifungal susceptibility are poorly known. The aims of this study were to investigate A. Terrei clinical isolates at the species level and to perform antifungal susceptibility analyses by reference and commercial methods. Eighty-two clinical A. Terrei isolates were collected from 8 French university hospitals. Molecular identification was performed by sequencing parts of beta-tubulin and calmodulin genes. MICs or minimum effective concentrations (MECs) were determined for 8 antifungal drugs using both EUCAST broth microdilution (BMD) methods and concentration gradient strips (CGS). Among the 79 A. Terrei isolates, A. terreus stricto sensu ( n = 61), A. citrinoterreus ( n = 13), A. hortai ( n = 3), and A. alabamensis ( n = 2) were identified. All strains had MICs of ≥1 mg/liter for amphotericin B, except for two isolates (both A. hortai ) that had MICs of 0.25 mg/liter. Four A. terreus isolates were resistant to at least one azole drug, including one with pan-azole resistance, yet no mutation in the CYP51A gene was found. All strains had low MECs for the three echinocandins. The essential agreements (EAs) between BMD and CGS were >90%, except for those of amphotericin B (79.7%) and itraconazole (73.4%). Isolates belonging to the A section Terrei identified in clinical samples show wider species diversity beyond the known A. terreus sensu stricto Azole resistance inside the section Terrei is uncommon and is not related to CYP51A mutations here. Finally, CGS is an interesting alternative for routine antifungal susceptibility testing. Copyright © 2018 American Society for Microbiology.

Epidemiology and antifungal susceptibilities of yeasts causing vulvovaginitis in a teaching hospital.

PubMed

Gamarra, Soledad; Morano, Susana; Dudiuk, Catiana; Mancilla, Estefanía; Nardin, María Elena; de Los Angeles Méndez, Emilce; Garcia-Effron, Guillermo

2014-10-01

Vulvovaginal candidiasis is one of the most common mycosis. However, the information about antifungal susceptibilities of the yeasts causing this infection is scant. We studied 121 yeasts isolated from 118 patients with vulvovaginal candidiasis. The isolates were identified by phenotypic and molecular methods, including four phenotypic methods described to differentiate Candida albicans from C. dubliniensis. Antifungal susceptibility testing was performed according to CLSI documents M27A3 and M27S4 using the drugs available as treatment option in the hospital. Diabetes, any antibacterial and amoxicillin treatment were statistically linked with vulvovaginal candidiasis, while oral contraceptives were not considered a risk factor. Previous azole-based over-the-counter antifungal treatment was statistically associated with non-C.albicans yeasts infections. The most common isolated yeast species was C. albicans (85.2 %) followed by C. glabrata (5 %), Saccharomyces cerevisiae (3.3 %), and C. dubliniensis (2.5 %). Fluconazole- and itraconazole-reduced susceptibility was observed in ten and in only one C. albicans strains, respectively. All the C. glabrata isolates showed low fluconazole MICs. Clotrimazole showed excellent potency against all but seven isolates (three C. glabrata, two S. cerevisiae, one C. albicans and one Picchia anomala). Any of the strains showed nystatin reduced susceptibility. On the other hand, terbinafine was the less potent drug. Antifungal resistance is still a rare phenomenon supporting the use of azole antifungals as empirical treatment of vulvovaginal candidiasis.

Evaluation of virulence factors and antifungal susceptibility patterns of different Candida species isolated from the female camel (Camelus dromedarius) genital tract.

PubMed

Sharifzadeh, Aghil; Soltani, Minoo; Shokri, Hojjatollah

2015-08-01

The purposes of this study were to investigate the enzymatic activity of different Candida species and their antifungal susceptibility patterns. The study involved a total of 83 isolates of Candida from the genital tract of the female Camelus dromedarius. After species identification, the isolates were analysed for the production/activity of phospholipase, proteinase and haemolysin. In addition, the agar disc diffusion method was performed on the basis of CLSI guidelines M44-A2 protocol for antifungal susceptibility testing. All the isolates were able to produce phospholipase, proteinase and haemolysin. A total of 35.48%, 87.09% and 64.51% of C. albicans isolates exhibited very high phospholipase, proteinase and haemolytic activities, respectively, whereas very high phospholipase, proteinase and haemolytic activities were determined in 5.76%, 23.07% and 45.16% of non-C. albicans isolates respectively. Overall, 61 (73.5%) of Candida isolates were susceptible to fluconazole, 70 (84.3%) susceptible to clotrimazole, 82 (98.8%) susceptible to voriconazole, 76 (91.6%) susceptible to itraconazole, 75 (90.4%) susceptible to ketoconazole, 83 (100%) susceptible to amphotericin B, 81 (97.6%) susceptible to nystatin and 36 (43.4%) susceptible to flucytosine. Candida isolates showed higher haemolytic activity than that of other secreted hydrolases among vaginal Candida species. In addition, amphotericin B was the most in vitro effective antifungal drug and flucytosine had the poorest activity under such conditions. © 2015 Blackwell Verlag GmbH.

Spectrophotometric reading of EUCAST antifungal susceptibility testing of Aspergillus fumigatus.

PubMed

Meletiadis, J; Leth Mortensen, K; Verweij, P E; Mouton, J W; Arendrup, M C

2017-02-01

Given the increasing number of antifungal drugs and the emergence of resistant Aspergillus isolates, objective, automated and high-throughput antifungal susceptibility testing is important. The EUCAST E.Def 9.3 reference method for MIC determination of Aspergillus species relies on visual reading. Spectrophotometric reading was not adopted because of concern that non-uniform filamentous growth might lead to unreliable and non-reproducible results. We therefore evaluated spectrophotometric reading for the determination of MICs of antifungal azoles against Aspergillus fumigatus. Eighty-eight clinical isolates of A. fumigatus were tested against four medical azoles (posaconazole, voriconazole, itraconazole, isavuconazole) and one agricultural azole (tebuconazole) with EUCAST E.Def 9.3. The visually determined MICs (complete inhibition of growth) were compared with spectrophotometrically determined MICs and essential (±1 twofold dilution) and categorical (susceptible/intermediate/resistant or wild-type/non-wild-type) agreement was calculated. Spectrophotometric data were analysed with regression analysis using the E max model, and the effective concentration corresponding to 5% (EC 5 ) was estimated. Using the 5% cut-off, high essential (92%-97%) and categorical (93%-99%) agreement (<6% errors) was found between spectrophotometric and visual MICs. The EC 5 also correlated with the visually determined MICs with an essential agreement of 83%-96% and a categorical agreement of 90%-100% (<5% errors). Spectrophotometric determination of MICs of antifungal drugs may increase objectivity, and allow automation and high-throughput of EUCAST E.Def 9.3 antifungal susceptibility testing of Aspergillus species. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Antifungal susceptibility of invasive Candida bloodstream isolates from the Asia-Pacific region.

PubMed

Tan, Thean Yen; Hsu, Li Yang; Alejandria, Marissa M; Chaiwarith, Romanee; Chinniah, Terrence; Chayakulkeeree, Methee; Choudhury, Saugata; Chen, Yen Hsu; Shin, Jong Hee; Kiratisin, Pattarachai; Mendoza, Myrna; Prabhu, Kavitha; Supparatpinyo, Khuanchai; Tan, Ai Ling; Phan, Xuan Thi; Tran, Thi Thanh Nga; Nguyen, Gia Binh; Doan, Mai Phuong; Huynh, Van An; Nguyen, Su Minh Tuyet; Tran, Thanh Binh; Van Pham, Hung

2016-07-01

Bloodstream infections caused by Candida species are of increasing importance and associated with significant mortality. We performed a multi-centre prospective observational study to identify the species and antifungal susceptibilities of invasive bloodstream isolates of Candida species in the Asia-Pacific region. The study was carried out over a two year period, involving 13 centers from Brunei, Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam. Identification of Candida species was performed at each study center, and reconfirmed at a central laboratory. Susceptibility testing was performed using a commercial broth dilution panel (Sensititre YeastOne YST-010, Thermofisher, United Kingdom) with susceptibility categorisation (S = susceptible, S-DD = susceptible dose-dependent) applied using breakpoints from the Clinical Laboratory Standards Institute. Eight hundred and sixty-one Candida isolates were included in the study. The most common species were C. albicans (35.9%), C. tropicalis (30.7%), C. parapsilosis (15.7%), and C. glabrata (13.6%). Non-albicans species exceeded C. albicans species in centers from all countries except Taiwan. Fluconazole susceptibility was almost universal for C. albicans (S = 99.7%) but lower for C. tropicalis (S = 75.8%, S-DD = 6.1%), C. glabrata (S-DD = 94.9%), and C. parapsilosis (S = 94.8%). Echinocandins demonstrated high rates of in vitro susceptibility (S>99%) against C. albicans, C. tropicalis, and C. parapsilosis This study demonstrates that non-albicans species are the most common isolates from bloodstream infections in most countries in the Asia-Pacific region, with C. tropicalis as the predominant species. Because of the prevalence of reduced susceptibility to fluconazole in non-albicans species, the study indicates that echinocandins should be the antifungal of choice in clinically unstable or high-risk patients with documented candidemia. © The Author 2016. Published by Oxford

Use of phylogenetical analysis to predict susceptibility of pathogenic Candida spp. to antifungal drugs.

PubMed

Maheux, Andrée F; Sellam, Adnane; Piché, Yves; Boissinot, Maurice; Pelletier, René; Boudreau, Dominique K; Picard, François J; Trépanier, Hélène; Boily, Marie-Josée; Ouellette, Marc; Roy, Paul H; Bergeron, Michel G

2016-12-01

Successful treatment of a Candida infection relies on 1) an accurate identification of the pathogenic fungus and 2) on its susceptibility to antifungal drugs. In the present study we investigated the level of correlation between phylogenetical evolution and susceptibility of pathogenic Candida spp. to antifungal drugs. For this, we compared a phylogenetic tree, assembled with the concatenated sequences (2475-bp) of the ATP2, TEF1, and TUF1 genes from 20 representative Candida species, with published minimal inhibitory concentrations (MIC) of the four principal antifungal drug classes commonly used in the treatment of candidiasis: polyenes, triazoles, nucleoside analogues, and echinocandins. The phylogenetic tree revealed three distinct phylogenetic clusters among Candida species. Species within a given phylogenetic cluster have generally similar susceptibility profiles to antifungal drugs and species within Clusters II and III were less sensitive to antifungal drugs than Cluster I species. These results showed that phylogenetical relationship between clusters and susceptibility to several antifungal drugs could be used to guide therapy when only species identification is available prior to information pertaining to its resistance profile. An extended study comprising a large panel of clinical samples should be conducted to confirm the efficiency of this approach in the treatment of candidiasis. Copyright © 2016. Published by Elsevier B.V.

Molecular identification and antifungal susceptibility of Curvularia australiensis, C. hawaiiensis and C. spicifera isolated from human eye infections.

PubMed

Krizsán, Krisztina; Tóth, Eszter; Nagy, László G; Galgóczy, László; Manikandan, Palanisamy; Chandrasekaran, Muthusamy; Kadaikunnan, Shine; Alharbi, Naiyf S; Vágvölgyi, Csaba; Papp, Tamás

2015-10-01

A reliable identification method was developed for three closely related Curvularia species, which are frequently isolated from human keratomycoses. Since the traditionally used morphological method and the increasingly used internal transcribed spacer (ITS)-based molecular method proved to be insufficient to discern C. australiensis, C. hawaiiensis and C. spicifera, other molecular targets, such as β-tubulin, translation elongation factor 1-α and the nuclear ribosomal intergenic spacer (IGS), were tested. Among them, the use of the highly divergent IGS sequence is suggested and the species-specific discriminating characters were determined in appropriate reference strains. It was also concluded that C. hawaiiensis and C. spicifera can be predominantly isolated from eye infections among the three species. The in vitro antifungal susceptibility of 10 currently used antifungal agents against 32 Curvularia isolates was also investigated. MICs were determined in each case. Isolates of C. spicifera proved to be less susceptible to the tested antifungals than those of C. hawaiiensis, which underline the importance of the correct identification of these species. © 2015 Blackwell Verlag GmbH.

An in vitro study of antifungal drug susceptibility of Candida species isolated from human immunodeficiency virus seropositive and human immunodeficiency virus seronegative individuals in Lucknow population Uttar Pradesh.

PubMed

Dar, Mohammad Shafi; Sreedar, Gadiputi; Shukla, Abhilasha; Gupta, Prashant; Rehan, Ahmad Danish; George, Jiji

2015-01-01

Candidiasis is the most common opportunistic infection in human immunodeficiency virus (HIV) seropositive patients, starting from asymptomatic colonization to pathogenic forms and gradual colonization of non-albicans in patients with advanced immunosuppression leads to resistance for azole group of antifungal drugs with high rate of morbidity and mortality. To isolate the Candida species and determine of antifungal drug susceptibility against fluconazole, itraconazole, nystatin, amphotericin B, and clotrimazolein HIV seropositive and control individuals, with or without clinical oropharyngeal candidiasis (OPC). Includes samples from faucial region of 70 subjects with and without clinical candidiasis in HIV seropositive and controls were aseptically inoculated onto Sabaraud's Dextrose Agar media and yeasts were identified for the specific species by Corn Meal Agar, sugar fermentation and heat tolerance tests. Antifungal drug susceptibility of the isolated species was done against above-mentioned drugs by E-test and disc diffusion method. The commonly isolated species in HIV seropositive and controls were Candida albicans, Candida glabrata and Candida tropicalis Candida guilliermondii and Candida dubliniensis isolated only in HIV seropositive patients. Susceptibility against selected antifungal drugs was observed more in HIV-negative individuals whereas susceptible dose-dependent and resistance were predominant in HIV-positive patients. Resistance is the major problem in the therapy of OPC, especially in HIV seropositive patients due to aggressive and prolonged use of antifungal agents, therefore, our study emphasizes the need for antifungal drug susceptibility testing whenever antifungal treatment is desired, especially in HIV-infected subjects.

In Vitro Susceptibilities of Malassezia Species to a New Triazole, Albaconazole (UR-9825), and Other Antifungal Compounds

PubMed Central

Garau, Margarita; Pereiro, Jr., Manolo; del Palacio, Amalia

2003-01-01

The in vitro activity of the new triazole albaconazole (UR-9825) in comparison with those of flucytosine, fluconazole, ketoconazole, itraconazole, and voriconazole against 70 strains of Malassezia spp. was determined by a microdilution method using a colorimetric indicator for metabolic activity. Albaconazole showed an in vitro profile similar to those of the different antifungals tested (MIC ≤ 0.06 μg/ml for all the strains). PMID:12821494

Biofilm production and antifungal susceptibility of co-cultured Malassezia pachydermatis and Candida parapsilosis isolated from canine seborrheic dermatitis.

PubMed

Bumroongthai, K; Chetanachan, P; Niyomtham, W; Yurayart, C; Prapasarakul, N

2016-07-01

The yeasts Malassezia (M.) pachydermatis and Candida (C.) parapsilosis are often co-isolated in case of canine seborrhea dermatitis (SD) and also are emerging as opportunistic pathogens of immunocompromised human beings. Increased information about how their relationship results in biofilm production and an antifungal response would be useful to inform treatment and control. This study was designed to investigate biofilm production derived from co-culture of M. pachydermatis and C. parapsilosis from dog skin and to determine their in vitro antifungal susceptibility. We demonstrated that regardless of yeast strain or origin all single and dual cultures produced biofilms within 24 hours, and the greatest amount was present after 72 hours. Biofilm production from mixed cultures was greater than for single strains (P < .05). All sessile forms of the single and dual cultures were resistant to the tested antifungals itraconazole and ketoconazole, whereas planktonic forms were susceptible. The study suggests that dual cultures produce stronger biofilms that are likely to enhance persistence in skin lesions in dogs and result in greater resistance to antifungal treatment. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

In vitro antifungal sensitivity of fluconazole, clotrimazole and nystatin against vaginal candidiasis in females of childbearing age.

PubMed

Khan, Fouzia; Baqai, Rakhshanda

2010-01-01

Vaginal candidiasis is the most common infection of females. A large variety of antifungal drugs are used for treatment. The objective of this study was isolation and identification of Candida from high vaginal swabs and in vitro antifungal activity of Clotrimazole, Fluconazole and Nystatin against Candida. Two hundred and fifty high vaginal swabs were collected from females reporting at different hospitals of Karachi. Wet mount was performed to observe the budding cells of Candida. Vaginal swabs were cultured on Sabouraud's dextrose agar with added antibiotics. Plates were incubated at room temperature for seven days. Chlamydospores of Candida albicans were identified on corn meal agar. Species of Candida were identified on Biggy agar. In vitro antifungal activity of Clotrimazole, Fluconazole and Nystatin was performed by MIC (Minimum inhibitory concentration), well diffusion method and disc diffusion method. Out of 250 high vaginal swabs, Candida species were isolated in 100 (40%) of cases. Out of 100, C. albican 30 (30%), C. tropicalis 21 (21%), C. parapsillosis 10 (10%), C. parakrusi 8 (8%), C. glabrata 8 (8%), C. krusei 3 (3%) were isolated. In vitro antifungal activity indicated Clotrimazole (MIC 16 and 8 microg/ml) effective against 68 (70%) of Candida SPP, Fluconazole (MIC 64 and 32 microg/ml) effective against 29 (36.2%) and Nystatin disc (100 units) was 51 (63.5%) effective. C. albicans was mainly isolated. Clotrimazole was more effective as compared to Fluconazole and Nystatin. Antifungal susceptibility testing should be determined before therapy to avoid treatment failures.

Synergistic effects of tacrolimus and azole antifungal compounds in fluconazole-susceptible and fluconazole-resistant Candida glabrata isolates.

PubMed

Denardi, Laura Bedin; Mario, Débora Alves Nunes; Loreto, Érico Silva; Santurio, Janio Morais; Alves, Sydney Hartz

2015-03-01

In vitro interaction between tacrolimus (FK506) and four azoles (fluconazole, ketoconazole, itraconazole and voriconazole) against thirty clinical isolates of both fluconazole susceptible and -resistant Candida glabrata were evaluated by the checkerboard microdilution method. Synergistic, indifferent or antagonism interactions were found for combinations of the antifungal agents and FK506. A larger synergistic effect was observed for the combinations of FK506 with itraconazole and voriconazole (43%), followed by that of the combination with ketoconazole (37%), against fluconazole-susceptible isolates. For fluconazole-resistant C. glabrata , a higher synergistic effect was obtained from FK506 combined with ketoconazole (77%), itraconazole (73%), voriconazole (63%) and fluconazole (60%). The synergisms that we observed in vitro , notably against fluconazole-resistant C. glabrata isolates, are promising and warrant further analysis of their applications in experimental in vivo studies.

Antifungal susceptibilities of Candida, Cryptococcus neoformans and Aspergillus fumigatus from the Asia and Western Pacific region: data from the SENTRY antifungal surveillance program (2010-2012).

PubMed

Pfaller, Michael A; Messer, Shawn A; Jones, Ronald N; Castanheira, Mariana

2015-09-01

The SENTRY Antifungal Surveillance Program monitors global susceptibility rates of newer and established antifungal agents. We report the in vitro activity of seven antifungal agents against 496 contemporary clinical isolates of yeasts and molds. The isolates were obtained from 20 laboratories in the Asia-Western Pacific (APAC) region during 2010 through 2012. Anidulafungin, caspofungin, micafungin, fluconazole, itraconazole, posaconazole and voriconazole were susceptibility tested using CLSI methods and species-specific interpretive criteria. Sequencing of fks hot spots was performed for echinocandin-resistant strains. Isolates included 13 species of Candida (n=460), 5 species of non-Candida yeasts (21), 5 species of Aspergillus (11) and 4 other molds. Echinocandin resistance was uncommon among eight species of Candida and was only detected in three isolates of Candida glabrata, two from Australia harboring mutations in fks1 (F625S) and fks2 (S663P). Resistance to the azoles was much more common and was observed among all species with the exception of Candida dubliniensis. Fluconazole resistance rates observed with C. glabrata (6.8%) was comparable to that seen with Candida parapsilosis (5.7%) and Candida tropicalis (3.6%). Cross resistance among the triazoles was seen with each of these three species. The mold-active azoles and the echinocandins were all active against isolates of Aspergillus fumigatus. Azole resistance was not detected among the isolates of Cryptococcus neoformans. Antifungal resistance is uncommon among isolates of fungi causing invasive fungal infections in the APAC region. As in other regions of the world, emerging resistance to the echinocandins among invasive isolates of C. glabrata bears close monitoring.

Biofilms and Antifungal Susceptibility Testing.

PubMed

Simitsopoulou, Maria; Chatzimoschou, Athanasios; Roilides, Emmanuel

2016-01-01

Yeasts and filamentous fungi both exist as single cells and hyphal forms, two morphologies used by most fungal organisms to create a complex multilayered biofilm structure. In this chapter we describe the most widely used assays for the determination of biofilm production and assessment of susceptibility of biofilms to antifungal agents or host phagocytes as various methods, the most frequent of which are staining, confocal laser scanning microscopy, quantification of extracellular DNA and protein associated with extracellular matrix and XTT metabolic reduction assay. Pathway-focused biofilm gene expression profiling is assessed by real-time reverse transcriptase polymerase chain reaction.

Evaluation of Candida species and antifungal susceptibilities among children with invasive candidiasis

PubMed Central

Sütçü, Murat; Acar, Manolya; Genç, Gonca Erköse; Kökçü, İlknur; Aktürk, Hacer; Atay, Gürkan; Törun, Selda Hançerli; Salman, Nuran; Erturan, Zayre; Somer, Ayper

2017-01-01

Aim Non-albicans Candida species and resistant microorganisms have been more commonly isolated in invasive candidiasis in recent years. The aim of this study was to evaluate the distrubution of Candida spp and antifungal resistance in our clinic. Material and Methods Fifty-four Candida isolates and antifungal susceptibility results obtained from patients diagnosed as having invasive candidiasis between December 2012 and June 2016 were included. Clinical and laboratory data were retrospectively analyzed. E-test method was used in order to determine antifungal susceptibilities of Candida spp for amphotericin B, fluconazole, voriconazole, ketoconazole, itraconazole, anidulafungin, caspofungin, and flucytosine. Results The clinical diagnoses of the patients were candidemia (n=27, 50%), catheter-related blood stream infection (n=1, 1.8%), urinary tract infection (n=13, 24%), surgical site infection (n=4, 7.4%), intraabdominal infection (n=3, 5.5%), empyema (n=2, 3.7%), and pneumonia (n=4, 7.4%). The most common isolated agent was C. albicans (n=27, 50%) and the others were C. parapsilosis (n=13, 24%), C. tropicalis (n=6, 11.1%), C. glabrata (n=3, 5.6%), C. lusitaniae (n=2, 3.7%), and unspecified Candida spp. (n=3, 5.6%). Fluconazole resistance was 7.4% among all isolates. Resistance against itraconazole, ketoconazole, anidulafungin, voriconazole and caspofungin were 33.3%, 12.5%, 11.1%, 5%, and 2.5%, respectively. Isolates presented intermediate resistance against itraconazole (41.7%), voriconazole (5.6%), and amphotericin B (3.7%) to varying extents. All of the isolates were susceptible to flucytosine. Conclusions In our clinic, C. albicans and non-albicans Candida species were equally distributed and antifungal susceptibilities against major antifungal agents such as fluconazole, amphotericin B, and caspofungin were found considerably high. PMID:29062248

Species distribution and antifungal susceptibility of Candida spp. isolated from superficial candidiasis in outpatients in Iran.

PubMed

Razzaghi-Abyaneh, M; Sadeghi, G; Zeinali, E; Alirezaee, M; Shams-Ghahfarokhi, M; Amani, A; Mirahmadi, R; Tolouei, R

2014-06-01

Candidiasis is the most prevalent fungal infection affecting human and animals all over the world. This study represents the epidemiological aspects of superficial candidiasis in outpatients and in vitro antifungal susceptibility of etiologic Candida species. Clinical samples were taken from 173 patients including skin and nail scrapings (107; 61.8%), vaginal discharge (28; 16.2%), sputum (20; 11.6%), oral swabs (7; 4.0%), bronchoalveolar lavage (6; 3.5%) and 1 specimen (0.6%) of each eye tumor, gastric juice, urine, biopsy and urinary catheter and confirmed as candidiasis by direct microscopy, culture and histopathology. Susceptibility patterns of the isolated Candida species were determined using the disk diffusion and broth microdilution methods. Among 173 Candida isolates, C. albicans (72.3%) was the most prevalent species followed by C. parapsilosis (11.5%). Other identified species were C. glabrata, C. krusei, C. tropicalis, C. guilliermondii, C. intermedia and C. sake. Majority of the Candida isolates were susceptible to fluconazole (95.4%) followed by 5-flucytosine (89.6%), voriconazole (78.6%) itraconazole (48.0%) and ketoconazole (42.8%). Caspofungin was the most potent antifungal drug against C. albicans (MICs; 0.062-1 μg/mL), ketoconazole for C. parapsilosis and C. tropicalis (MICs; 0.031-0.25 μg/mL) and itraconazole for C. krusei, C. glabrata and C. guilliermondii (MICs; 0.031-1 μg/mL). This study reinforces the significance of superficial candidiasis as an important fungal infection with multiple clinical presentations. Our results further indicate that susceptibility testing to commonly used antifungals is crucial in order to select the appropriate therapeutic strategies which minimize complications while improving patients' life. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Water quality and antifungal susceptibility of opportunistic yeast pathogens from rivers.

PubMed

Monapathi, M E; Bezuidenhout, C C; Rhode, O H J

2017-03-01

Yeasts from water sources have been associated with diseases ranging from superficial mucosal infections to life threatening diseases. The aim of this study was to determine the water quality as well as diversity and antifungal susceptibility of yeasts from two rivers. Yeast levels and physico-chemical parameter data were analyzed by principal component analysis to determine correlations between physico-chemical data and yeast levels. Yeast morphotypes were identified by biochemical tests and 26S rRNA gene sequencing. Disk diffusion antifungal susceptibility tests were conducted. Physico-chemical parameters of the water were within target water quality range (TWQR) for livestock farming. For irrigational use, total dissolved solids and nitrates were not within the TWQR. Yeast levels ranged between 27 ± 10 and 2,573 ± 306 cfu/L. Only non-pigmented, ascomycetous yeasts were isolated. Saccharomyces cerevisiae and Candida glabrata were most frequently isolated. Several other opportunistic pathogens were also isolated. A large number of isolates were resistant to azoles, especially fluconazole, but also to other antifungal classes. Candida species were resistant to almost all the antifungal classes. These water sources are used for recreation and religious as well as for watering livestock and irrigation. Of particular concern is the direct contact of individuals with opportunistic yeast, especially the immune-compromised. Resistance of these yeast species to antifungal agents is a further health concern.

The In Vitro Efficacy of Essential Oils and Antifungal Drugs Against Prototheca zopfii.

PubMed

Grzesiak, Barbara; Głowacka, Anna; Krukowski, Henryk; Lisowski, Andrzej; Lassa, Henryka; Sienkiewicz, Monika

2016-08-01

The algae of the genus Prototheca are environmental pathogens whose main reservoir is the habitat of cows. They can cause protothecosis in domestic and wild animals, as well as human beings, with the main etiological agents being Prototheca zopfii in animals and Prototheca wickerhamii in humans. The aim of the study was to evaluate the in vitro activity of selected essential oils and antifungal antibiotics against P. zopfii isolates. The material consisted of nine P. zopfii strains isolated from the milk of cows suffering from mastitis. Eight essential oils produced by POLLENA-AROMA, Poland, and nine antifungal agents were tested. The effects of essential oils on P. zopfii were evaluated by microdilution with liquid Sabouraud dextrose broth, and susceptibility to antifungal agents was tested using the disk-diffusion method. All used essential oils inhibited the activity of P. zopfii isolates, with MIC values ranging from 0.2 to 10.5 μl/ml. Cinnamon, clove, and thyme demonstrated the highest activity against the tested P. zopfii strains at concentrations ranging from 0.6 to 1.0 μl/ml. Of the antifungal agents, the tested strains were the most sensitive to nystatin (100 %). The tested essential oils can be used to complement protothecosis therapy in animals and human beings.

Diversity, in-vitro virulence traits and antifungal susceptibility pattern of gastrointestinal yeast flora of healthy poultry, Gallus gallus domesticus.

PubMed

Subramanya, Supram Hosuru; Sharan, Nawal Kishor; Baral, Bharat Prasad; Hamal, Deependra; Nayak, Niranjan; Prakash, Peralam Yegneswaran; Sathian, Brijesh; Bairy, Indira; Gokhale, Shishir

2017-05-15

Poultry farming and consumption of poultry (Gallus gallus domesticus) meat and eggs are common gastronomical practices worldwide. Till now, a detailed understanding about the gut colonisation of Gallus gallus domesticus by yeasts and their virulence properties and drug resistance patterns in available literature remain sparse. This study was undertaken to explore this prevalent issue. A total of 103 specimens of fresh droppings of broiler chickens (commercial G domesticus) and domesticated chickens (domesticated G domesticus) were collected from the breeding sites. The isolates comprised of 29 (33%) Debaryozyma hansenii (Candida famata), 12 (13.6%) Sporothrix catenata (C. ciferrii), 10 (11.4%) C. albicans, 8 (9.1%) Diutnia catenulata (C. catenulate), 6 (6.8%) C. tropicalis, 3 (3.4%) Candida acidothermophilum (C. krusei), 2 (2.3%) C. pintolopesii, 1 (1.1%) C. parapsilosis, 9 (10.2%) Trichosporon spp. (T. moniliiforme, T. asahii), 4 (4.5%) Geotrichum candidum, 3 (3.4%) Cryptococcus macerans and 1 (1%) Cystobasidium minuta (Rhodotorula minuta). Virulence factors, measured among different yeast species, showed wide variability. Biofilm cells exhibited higher Minimum Inhibitory Concentration (MIC) values (μg/ml) than planktonic cells against all antifungal compounds tested: (fluconazole, 8-512 vs 0.031-16; amphotericin B, 0.5-64 vs 0.031-16; voriconazole 0.062-16 vs 0.062-8; caspofungin, 0.062-4 vs 0.031-1). The present work extends the current understanding of in vitro virulence factors and antifungal susceptibility pattern of gastrointestinal yeast flora of G domesticus. More studies with advanced techniques are needed to quantify the risk of spread of these potential pathogens to environment and human.

Antifungal susceptibility of Malassezia furfur, Malassezia sympodialis, and Malassezia globosa to azole drugs and amphotericin B evaluated using a broth microdilution method.

PubMed

Rojas, Florencia D; Sosa, María de los A; Fernández, Mariana S; Cattana, María E; Córdoba, Susana B; Giusiano, Gustavo E

2014-08-01

We studied the in vitro activity of fluconazole (FCZ), ketoconazole (KTZ), miconazole (MCZ), voriconazole (VCZ), itraconazole (ITZ) and amphotericin B (AMB) against the three major pathogenic Malassezia species, M. globosa, M. sympodialis, and M. furfur. Antifungal susceptibilities were determined using the broth microdilution method in accordance with Clinical and Laboratory Standards Institute reference document M27-A3. To support lipid-dependent yeast development, glucose, peptone, ox bile, malt extract, glycerol, and Tween supplements were added to Roswell Park Memorial Institute RPMI 1640 medium. The supplemented medium allowed good growth of all three species studied. The minimal inhibitory concentrations (MICs) were recorded after 72 h of incubation at 32ºC. The three species showed different susceptibility profiles for the drugs tested. Malassezia sympodialis was the most susceptible and M. furfur the least susceptible species. KTZ, ITZ, and VCZ were the most active drugs, showing low variability among isolates of the same species. FCZ, MCZ, and AMB showed high MICs and wide MIC ranges. Differences observed emphasize the need to accurately identify and evaluate antifungal susceptibility of Malassezia species. Further investigations and collaborative studies are essential for correlating in vitro results with clinical outcomes since the existing limited data do not allow definitive conclusions. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The European Confederation of Medical Mycology (ECMM) survey of candidaemia in Italy: in vitro susceptibility of 375 Candida albicans isolates and biofilm production.

PubMed

Tortorano, Anna Maria; Prigitano, Anna; Biraghi, Emanuela; Viviani, Maria Anna

2005-10-01

To investigate the in vitro antifungal susceptibility pattern of 375 Candida albicans bloodstream isolates recovered during the European Confederation of Medical Mycology survey of candidaemia performed in Lombardia, Italy and to test the ability to form biofilm. In vitro susceptibility to flucytosine, fluconazole, itraconazole, posaconazole, voriconazole and caspofungin was performed by broth microdilution following the NCCLS guidelines. Biofilm production was measured using the XTT reduction assay in 59 isolates selected as representative of different patterns of susceptibility to flucytosine and azoles. MICs (mg/L) at which 90% of the strains were inhibited were < or =0.25 for flucytosine, 0.25 for caspofungin, 4 for fluconazole and 0.06 for itraconazole, voriconazole and posaconazole. Flucytosine resistance was detected in five isolates and was associated with serotype B in 2/29 and serotype A in 3/346. Resistance to fluconazole was detected in 10 isolates; nine of these exhibited reduced susceptibility to the other azoles. Among the 10 patients with fluconazole-resistant C. albicans bloodstream infection, only one, an AIDS patient, had been previously treated with fluconazole. Biofilm production was observed in 23 isolates (39%) and was significantly associated with serotype B. No relationship was detected with the pattern of antifungal susceptibility. Resistance is uncommon in C. albicans isolates recovered from blood cultures, while biofilm production is a relatively frequent event. Periodic surveillance is warranted to monitor the incidence of in vitro antifungal resistance as well as of biofilm production.

[Susceptibility to antifungal agents of Candida sp. and biofilm formation].

PubMed

Ciok-Pater, Emilia; Białucha, Agata; Gospodarek, Eugenia; Ostafin, Agnieszka

2011-01-01

In recent years the increase in frequency of fungal infections with Candida sp. was noticed. These infections are connected with ability of Candida sp. to form biofilm on surfaces of biomaterials used in medicine. Furthermore fungal infections make serious therapeutic problems because ofbiofilm resistance to antifungal agents actually. The aim of the study was to evaluate the susceptibility to antifungal agents of Candida sp. and their ability to form biofilm on different biomaterials. 50 strains of Candida sp. isolated from patients of University Hospital No. 1 of dr A. Jurasz in Bydgoszcz were examined. API Candida (bioMérieux) tests were used to identify Candida sp. strains. The susceptibility of the yeast strains to antifungal agents was evaluated by ATB FUNGUS 2 INT (bioMérieux) tests. The susceptibility of examined strains to voriconazole, posaconazole, caspofungin and anidulafungin was assessed by means ofEtests (AB BIODISK) method employing drug concentrations from 0,002 to 32 microg/ml. All analysed strains were susceptible to amphotericin B and caspofungin. Biofilm formation on different biomaterials (silicon, latex, polychloride vinyl, polypropylene, nylon) was measured after 72 hour incubation at 37 degrees C. All examined yeasts formed biofilm on all analysed biomaterials. The highest number of strains formed biofilm on surface of polychloride vinyl: 23 (92,0%) by C. albicans strains and 24 (96,0%) Candida non-albicans strains. The lowest number of the strains formed biofilm on the surface of nylon: 12 (48,0%) of C. albicans strains and 9 (36,0%) of Candida non-albicans strains. The studied strains resistant to azoles and anidulafungin display stronger ability to form biofilm on surfaces of all analysed biomaterials.

Evaluation of Virulence Factors In vitro, Resistance to Osmotic Stress and Antifungal Susceptibility of Candida tropicalis Isolated from the Coastal Environment of Northeast Brazil

PubMed Central

Zuza-Alves, Diana L.; de Medeiros, Sayama S. T. Q.; de Souza, Luanda B. F. C.; Silva-Rocha, Walicyranison P.; Francisco, Elaine C.; de Araújo, Maria C. B.; Lima-Neto, Reginaldo G.; Neves, Rejane P.; Melo, Analy S. de Azevedo; Chaves, Guilherme M.

2016-01-01

Several studies have been developed regarding human health risks associated with the recreational use of beaches contaminated with domestic sewage. These wastes contain various micro-organisms, including Candida tropicalis. In this context, the objective of this study was to characterize C. tropicalis isolates from the sandy beach of Ponta Negra, Natal, Rio Grande do Norte, Brazil, regarding the expression of in vitro virulence factors, adaptation to osmotic stress and susceptibility to antifungal drugs. We analyzed 62 environmental isolates and observed a great variation among them for the various virulence factors evaluated. In general, environmental isolates were more adherent to human buccal epithelial cells (HBEC) than C. tropicalis ATCC13803 reference strain, and they also showed increased biofilm production. Most of the isolates presented wrinkled phenotypes on Spider medium (34 isolates, 54.8%). The majority of the isolates also showed higher proteinase production than control strains, but low phospholipase activity. In addition, 35 isolates (56.4%) had high hemolytic activity (hemolysis index > 0.55). With regard to C. tropicalis resistance to osmotic stress, 85.4% of the isolates were able to grow in a liquid medium containing 15% sodium chloride. The strains were highly resistant to the azoles tested (fluconazole, voriconazole and itraconazole). Fifteen strains were resistant to the three azoles tested (24.2%). Some strains were also resistant to amphotericin B (14 isolates; 22.6%), while all of them were susceptible for the echinocandins tested, except for a single strain of intermediate susceptibility to micafungin. Our results demonstrate that C. tropicalis isolated from the sand can fully express virulence attributes and showed a high persistence capacity on the coastal environment; in addition of showing high minimal inhibitory concentrations to several antifungal drugs used in current clinical practice, demonstrating that environmental isolates may

Evaluation of Virulence Factors In vitro, Resistance to Osmotic Stress and Antifungal Susceptibility of Candida tropicalis Isolated from the Coastal Environment of Northeast Brazil.

PubMed

Zuza-Alves, Diana L; de Medeiros, Sayama S T Q; de Souza, Luanda B F C; Silva-Rocha, Walicyranison P; Francisco, Elaine C; de Araújo, Maria C B; Lima-Neto, Reginaldo G; Neves, Rejane P; Melo, Analy S de Azevedo; Chaves, Guilherme M

2016-01-01

Several studies have been developed regarding human health risks associated with the recreational use of beaches contaminated with domestic sewage. These wastes contain various micro-organisms, including Candida tropicalis . In this context, the objective of this study was to characterize C. tropicalis isolates from the sandy beach of Ponta Negra, Natal, Rio Grande do Norte, Brazil, regarding the expression of in vitro virulence factors, adaptation to osmotic stress and susceptibility to antifungal drugs. We analyzed 62 environmental isolates and observed a great variation among them for the various virulence factors evaluated. In general, environmental isolates were more adherent to human buccal epithelial cells (HBEC) than C. tropicalis ATCC13803 reference strain, and they also showed increased biofilm production. Most of the isolates presented wrinkled phenotypes on Spider medium (34 isolates, 54.8%). The majority of the isolates also showed higher proteinase production than control strains, but low phospholipase activity. In addition, 35 isolates (56.4%) had high hemolytic activity (hemolysis index > 0.55). With regard to C. tropicalis resistance to osmotic stress, 85.4% of the isolates were able to grow in a liquid medium containing 15% sodium chloride. The strains were highly resistant to the azoles tested (fluconazole, voriconazole and itraconazole). Fifteen strains were resistant to the three azoles tested (24.2%). Some strains were also resistant to amphotericin B (14 isolates; 22.6%), while all of them were susceptible for the echinocandins tested, except for a single strain of intermediate susceptibility to micafungin. Our results demonstrate that C. tropicalis isolated from the sand can fully express virulence attributes and showed a high persistence capacity on the coastal environment; in addition of showing high minimal inhibitory concentrations to several antifungal drugs used in current clinical practice, demonstrating that environmental isolates

Luliconazole, an alternative antifungal agent against Aspergillus terreus.

PubMed

Zargaran, M; Taghipour, S; Kiasat, N; Aboualigalehdari, E; Rezaei-Matehkolaei, A; Zarei Mahmoudabadi, A; Shamsizadeh, F

2017-09-01

Aspergillus terreus is the fourth leading cause of invasive and non-invasive aspergillosis and one of the causative agents of morbidity and mortality among immunocompromised and high-risk patients. A. terreus appears to have increased as a cause of opportunistic fungal infections from superficial to serious invasive infections. Although, invasive aspergillosis is often treated empirically with amphotericin B, most A. terreus isolates are resistant both in vivo and in vitro to some antifungal drugs. In this study, we aimed to evaluate antifungals susceptibility profiles of the different strains of A. terreus against amphotericin B, caspofungin, fluconazole, voriconazole, posaconazole and luliconazole. Forty A. terreus strains originating from environmental sources (air and soil) were identified using by macroscopic and microscopic features. Six antifungals including, amphotericin B, caspofungin, fluconazole, voriconazole, posaconazole and luliconazole were applied for susceptibility tests. Our results show that tested isolates had different susceptibility to antifungals. The lowest MIC GM related to luliconazole (0.00236μg/ml), followed by posaconazole (0.18621μg/ml), voriconazole (0.22925μg/ml), caspofungin (0.86μg/ml), fluconazole (8μg/ml) and amphotericin B (11.12μg/ml). This study demonstrated that luliconazole had an excellent in vitro activity against all tested isolates of A. terreus, with MIC GM 0.00236μg/mL than other tested antifungals. As a result, luliconazole could be a possible alternative antifungal for the treatment of aspergillosis due to A. terreus. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

[In vitro antifungal activity of azoles and amphotericin B against Malassezia furfur by the CLSI M27-A3 microdilution and Etest® methods].

PubMed

Galvis-Marín, Juan Camilo; Rodríguez-Bocanegra, María Ximena; Pulido-Villamarín, Adriana Del Pilar; Castañeda-Salazar, Rubiela; Celis-Ramírez, Adriana Marcela; Linares-Linares, Melva Yomary

Malassezia furfur is a human skin commensal yeast that can cause skin and opportunistic systemic infections. Given its lipid dependant status, the reference methods established by the Clinical and Laboratory Standards Institute (CLSI) to evaluate antifungal susceptibility in yeasts are not applicable. To evaluate the in vitro susceptibility of M. furfur isolates from infections in humans to antifungals of clinical use. The susceptibility profile to amphotericin B, itraconazole, ketoconazole and voriconazole of 20 isolates of M. furfur, using the broth microdilution method (CLSI M27-A3) and Etest ® , was evaluated. Itraconazole and voriconazole had the highest antifungal activity against the isolates tested. The essential agreement between the two methods for azoles antifungal activity was in the region of 60-85% and the categorical agreement was around 70-80%, while the essential and categorical agreement for amphotericin B was 10%. The azoles were the compounds that showed the highest antifungal activity against M. furfur, as determined by the two techniques used; however more studies need to be performed to support that Etest ® is a reliable method before its implementation as a routine clinical laboratory test. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

In vitro antifungal activity of antipsychotic drugs and their combinations with conventional antifungals against Scedosporium and Pseudallescheria isolates.

PubMed

Homa, Mónika; Galgóczy, László; Tóth, Eszter; Tóth, Liliána; Papp, Tamás; Chandrasekaran, Muthusamy; Kadaikunnan, Shine; Alharbi, Naiyf S; Vágvölgyi, Csaba

2015-11-01

In the present study, in vitro antifungal activities of five antipsychotic drugs (i.e., chlorpromazine hydrochloride, CPZ; trifluoperazine hydrochloride, TPZ; amantadine hydrochloride; R-(-)-deprenyl hydrochloride, and valproic acid sodium salt) and five conventional antifungal drugs (i.e., amphotericin B, AMB; caspofungin, CSP; itraconazole; terbinafine, TRB and voriconazole, VRC) were investigated in broth microdilution tests against four clinical and five environmental Scedosporium and Pseudallescheria isolates. When used alone, phenothiazines CPZ and TPZ exerted remarkable antifungal effects. Thus, their in vitro combinations with AMB, CSP, VRC, and TRB were also examined against the clinical isolates. In combination with antifungal agents, CPZ was able to act synergistically with AMB and TRB in cases of one and two isolates, respectively. In all other cases, indifferent interactions were revealed. Antagonism was not observed between the tested agents. These combinations may establish a more effective and less toxic therapy after further in vitro and in vivo studies for Scedosporium and Pseudallescheria infections. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

In vitro antifungal activity of three geophytic plant extracts against three post-harvest pathogenic fungi.

PubMed

Maswada, Hanafey F; Abdallah, Sabry A

2013-12-01

Plant extracts appear to be one of the most effective alternative methods of plant diseases control which are less harmful to human beings and environment. In vitro antifungal activity of methanolic extracts of three promising wild geophytic plants against three post-harvest pathogenic fungi using radial growth technique was conducted. These extracts included the shoot system (S) and underground parts (R) of Asparagus stipularis, Cyperus capitatus and Stipagrostis lanata. The tested fungi were Alternaria solani, Aspergillus niger and Rhizopus stolonifer. The results exhibited that, all plant extracts had antifungal activity against the tested fungi. The antifungal activity greatly varied depending on plant parts and/or plant species. R. stolonifer was the most susceptible fungus to the tested plant extracts followed by A. niger and then A. solani. On the other hand, the most effective plant extracts against tested fungi were S. lanata (S) and A. stipularis (R). The most effective plant extracts against R. stolonifer were S. lanata (R) and C. capitatus (S). While, the extracts of A. stipularis (R) and S. lanata (S) were the most effective against A. niger. The extracts of C. capitatus (S) and S. lanata (S) exhibited the highest antifungal activity against A. solani. The results demonstrated that, the methanolic extracts of A. stipularis, C. capitatus and S. lanata had potential antifungal activity against A. solani, A. niger and R. stolonifer.

In vitro susceptibility of 137 Candida sp. isolates from HIV positive patients to several antifungal drugs.

PubMed

Magaldi, S; Mata, S; Hartung, C; Verde, G; Deibis, L; Roldán, Y; Marcano, C

2001-01-01

Oropharyngeal candidiasis caused by various species of Candida is one of the most common infections in HIV seropositive or AIDS patients. Drug resistance among these yeasts is an increasing problem. We studied the frequency of resistance profile to fluconazole, itraconazole, ketoconazole, amphotericin B and terbinafine of 137 isolates of Candida sp. From HIV positive or AIDS patients with oropharyngeal candidiasis at Instituto de Inmunología, U.C.V. and the Hospital "Jose Ignacio Baldó", Caracas Venezuela, using the well diffusion susceptibility test (Magaldi et al.). We found that nearly 10% of C. albicans isolates were primarily fluconazole resistant, 45% of C. albicans isolates from patients with previous treatment were resistant to fluconazole, of which 93% showed cross-resistance to itraconazole, and even about 30% of C. tropicalis (n = 13) were resistant to fluconazole and/or itraconazole. To this respect, several recent reports have been described antifungal cross-resistance among azoles. Therefore, we consider that C. tropicalis should be added to the growing list of yeast in which antifungal drug resistance is common. This report could be useful for therapeutic aspect in AIDS patients with oral candidiasis.

Rapid antifungal susceptibility testing by matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis.

PubMed

Vella, Antonietta; De Carolis, Elena; Vaccaro, Luisa; Posteraro, Patrizia; Perlin, David S; Kostrzewa, Markus; Posteraro, Brunella; Sanguinetti, Maurizio

2013-09-01

The widespread use of antifungal agents, which is likely to expand with their enhanced availability, has promoted the emergence of drug-resistant strains. Antifungal susceptibility testing (AFST) is now an essential procedure for guiding appropriate antifungal therapy. Recently, we developed a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based method that enables the detection of fungal isolates with reduced echinocandin susceptibility, relying on the proteome changes that are detectable after a 15-h exposure of fungal cells to serial drug concentrations. Here, we describe a simplified version of this approach that facilitates discrimination of the susceptible and resistant isolates of Candida albicans after a 3-h incubation in the presence of "breakpoint" level drug concentrations of the echinocandin caspofungin (CSF). Spectra at concentrations of 0 (null), 0.03 (intermediate), and 32 (maximal) μg/ml of CSF were used to create individual composite correlation index (CCI) matrices for 65 C. albicans isolates, including 13 fks1 mutants. Isolates are then classified as susceptible or resistant to CSF if the CCI values of spectra at 0.03 and 32 μg/ml are higher or lower, respectively, than the CCI values of spectra at 0.03 and 0 μg/ml. In this way, the drug resistance of C. albicans isolates to echinocandin antifungals can be quickly assessed. Furthermore, the isolate categorizations determined using MALDI-TOF MS-based AFST (ms-AFST) were consistent with the wild-type and mutant FKS1 genotypes and the AFST reference methodology. The ms-AFST approach may provide a rapid and reliable means of detecting emerging antifungal resistance and accelerating the initiation of appropriate antifungal treatment.

New record of Scedosporium dehoogii from Chile: Phylogeny and susceptibility profiles to classic and novel putative antifungal agents.

PubMed

Alvarez, Eduardo; Sanhueza, Camila

Scedosporium species are considered emerging agents causing illness in immunocompromised patients. In Chile, only Scedosporium apiospermum, Scedosporium boydii and Lomentospora prolificans haven been reported previously. The study aimed to characterize genetically Scedosporium dehoogii strains from Chilean soil samples, and assessed the antifungal susceptibility profile to classic and novel putative antifungal molecules. In 2014, several samples were obtained during a survey of soil fungi in urban areas from Chile. Morphological and phylogenetic analyses of the internal transcribed spacer region (ITS), tubulin (TUB), and calmodulin (CAL) sequences were performed. In addition, the susceptibility profiles to classic antifungal and new putative antifungal molecules were determined. Four strains of Scedosporium dehoogii were isolated from soil samples. The methodology confirmed the species (reported here as a new record for Chile). Antifungal susceptibility testing demonstrates the low activity of terpenes (α-pinene and geraniol) against this species. Voriconazole (VRC), posaconazole (PSC), and the hydroxyquinolines (clioquinol, and 5,7-dibromo-8-hydroxyquinoline) showed the best antifungal activity. Our results demonstrate that Scedosporium dehoogii is present in soil samples from Chile. This study shows also that hydroxyquinolines have potential as putative antifungal molecules. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

Candidaemia and antifungal susceptibility testing in a teaching hospital.

PubMed

Tzar, M N; Shamim, A S

2009-03-01

We reviewed cases of candidaemia at Universiti Kebangsaan Malaysia Medical Centre from 1st January 2005 to 30th June 2006. All blood cultures positive for Candida species or its teleomorphs within the study period were identified and antifungal susceptibility testing was performed. Out of 50 blood isolates, 20 (40%) were identified as Candida albicans, 16 (32%) C. tropicalis, five (10%) C. parapsilosis, three (6%) C. famata, two (4%) C. glabrata, two (4%) Pichia ohmeri, one (2%) C. krusei and one (2%) P. etchell/carsonii. Susceptibility to amphotericin B was 100%, fluconazole 90%, itraconazole 40%, ketoconazole 88%, 5-flucytosine 98% and voriconazole 98%.

Risk of Fungemia Due to Rhodotorula and Antifungal Susceptibility Testing of Rhodotorula Isolates

PubMed Central

Zaas, Aimee K.; Boyce, Molly; Schell, Wiley; Lodge, Barbara Alexander; Miller, Jackie L.; Perfect, John R.

2003-01-01

Rhodotorula infections occur among patients with immunosuppression and/or central venous catheters. Using standardized methods (NCCLS M27-A), we determined the antifungal susceptibilities of 10 Rhodotorula bloodstream infection isolates. Patient information was collected for clinical correlation. The MICs of amphotericin B and posaconazole were the lowest, and the MICs of triazoles and echinocandins were higher than those of other antifungal agents. PMID:14605170

Molecular identification and antifungal susceptibility profile of Candida species isolated from patients with vulvovaginitis in Tehran, Iran.

PubMed

Sharifynia, Somayeh; Falahati, Mehraban; Akhlaghi, Lame; Foroumadi, Alireza; Fateh, Roohollah

2017-01-01

Rapid and accurate identification and evaluation of antifungal susceptibility pattern of Candida isolates are crucial to determine suitable antifungal drugs for the treatment of patients with vulvovaginitis candidiasis. Vaginal samples were collected from 150 women with suspicious vaginal candidiasis, and then cultured on Sabouraoud's Dextrose Agar with chloramphenicol to isolate Candida species. After identification of Candida isolates using polymerase chain reaction-restriction fragment length polymorphism technique, antifungal susceptibility testing of four azolic antifungal drugs was carried out using broth microdilution method according to the CLSI M27-A3. Candida species were isolated from eighty suspected patients (61.79%). The most common pathogen was Candida albicans (63.75%). Resistance to fluconazole and ketoconazole was observed in 27.5% and 23.75% of Candida isolates, respectively, and only 2% of Candida isolates were resistant to miconazole. Interestingly, resistance to fluconazole in C. albicans was more than other Candida species. The results indicated that therapy should be selected according to the antifungal susceptibility tests for the prevention of treatment failure and miconazole therapy can be considered as the best therapeutic choice in the management of vulvovaginitis.

Molecular identification and antifungal susceptibility profile of Candida species isolated from patients with vulvovaginitis in Tehran, Iran

PubMed Central

Sharifynia, Somayeh; Falahati, Mehraban; Akhlaghi, Lame; Foroumadi, Alireza; Fateh, Roohollah

2017-01-01

Background: Rapid and accurate identification and evaluation of antifungal susceptibility pattern of Candida isolates are crucial to determine suitable antifungal drugs for the treatment of patients with vulvovaginitis candidiasis. Materials and Methods: Vaginal samples were collected from 150 women with suspicious vaginal candidiasis, and then cultured on Sabouraoud's Dextrose Agar with chloramphenicol to isolate Candida species. After identification of Candida isolates using polymerase chain reaction-restriction fragment length polymorphism technique, antifungal susceptibility testing of four azolic antifungal drugs was carried out using broth microdilution method according to the CLSI M27-A3. Results: Candida species were isolated from eighty suspected patients (61.79%). The most common pathogen was Candida albicans (63.75%). Resistance to fluconazole and ketoconazole was observed in 27.5% and 23.75% of Candida isolates, respectively, and only 2% of Candida isolates were resistant to miconazole. Interestingly, resistance to fluconazole in C. albicans was more than other Candida species. Conclusion: The results indicated that therapy should be selected according to the antifungal susceptibility tests for the prevention of treatment failure and miconazole therapy can be considered as the best therapeutic choice in the management of vulvovaginitis. PMID:29387119

Potato Dextrose Agar Antifungal Susceptibility Testing for Yeasts and Molds: Evaluation of Phosphate Effect on Antifungal Activity of CMT-3

PubMed Central

Liu, Yu; Tortora, George; Ryan, Maria E.; Lee, Hsi-Ming; Golub, Lorne M.

2002-01-01

The broth macrodilution method (BMM) for antifungal susceptibility testing, approved by the National Committee for Clinical Laboratory Standards (NCCLS), was found to have deficiencies in testing of the antifungal activity of a new type of antifungal agent, a nonantibacterial chemically modified tetracycline (CMT-3). The high content of phosphate in the medium was found to greatly increase the MICs of CMT-3. To avoid the interference of phosphate in the test, a new method using potato dextrose agar (PDA) as a culture medium was developed. Eight strains of fungi, including five American Type Culture Collection strains and three clinical isolates, were used to determine the MICs of amphotericin B and itraconazole with both the BMM and the PDA methods. The MICs of the two antifungal agents determined with the PDA method showed 99% agreement with those determined with the BMM method within 1 log2 dilution. Similarly, the overall reproducibility of the MICs with the PDA method was above 97%. Three other antifungal agents, fluconazole, ketoconazole, and CMT-3, were also tested in parallel against yeasts and molds with both the BMM and the PDA methods. The MICs of fluconazole and ketoconazole determined with the PDA method showed 100% agreement within 1 log2 dilution of those obtained with the BMM method. However, the MICs of CMT-3 determined with the BMM method were as high as 128 times those determined with the PDA method. The effect of phosphate on the antifungal activity of CMT-3 was evaluated by adding Na2HPO4 to PDA in the new method. It was found that the MIC of CMT-3 against a Penicillium sp. increased from 0.5 μg/ml (control) to 2.0 μg/ml when the added phosphate was used at a concentration of 0.8 mg/ml, indicating a strong interference of Na2HPO4 with the antifungal activity of CMT-3. Except for fluconazole, all the other antifungal agents demonstrated clear end points among the yeasts and molds tested. Nevertheless, with its high reproducibility, good

Antifungal Susceptibility Testing of Malassezia spp. with an Optimized Colorimetric Broth Microdilution Method.

PubMed

Leong, Cheryl; Buttafuoco, Antonino; Glatz, Martin; Bosshard, Philipp P

2017-06-01

Malassezia is a genus of lipid-dependent yeasts. It is associated with common skin diseases such as pityriasis versicolor and atopic dermatitis and can cause systemic infections in immunocompromised individuals. Owing to the slow growth and lipid requirements of these fastidious yeasts, convenient and reliable antifungal drug susceptibility testing assays for Malassezia spp. are not widely available. Therefore, we optimized a broth microdilution assay for the testing of Malassezia that is based on the CLSI and EUCAST assays for Candida and other yeasts. The addition of ingredients such as lipids and esculin provided a broth medium formulation that enabled the growth of all Malassezia spp. and could be read, with the colorimetric indicator resazurin, by visual and fluorescence readings. We tested the susceptibility of 52 strains of 13 Malassezia species to 11 commonly used antifungals. MIC values determined by visual readings were in good agreement with MIC values determined by fluorescence readings. The lowest MICs were found for the azoles itraconazole, posaconazole, and voriconazole, with MIC 90 values of 0.03 to 1.0 μg/ml, 0.06 to 0.5 μg/ml, and 0.03 to 2.0 μg/ml, respectively. All Malassezia spp. were resistant to echinocandins and griseofulvin. Some Malassezia spp. also showed high MIC values for ketoconazole, which is the most widely recommended topical antifungal to treat Malassezia skin infections. In summary, our assay enables the fast and reliable susceptibility testing of Malassezia spp. with a large panel of different antifungals. Copyright © 2017 American Society for Microbiology.

Antifungal Susceptibility Testing of Malassezia spp. with an Optimized Colorimetric Broth Microdilution Method

PubMed Central

Leong, Cheryl; Buttafuoco, Antonino

2017-01-01

ABSTRACT Malassezia is a genus of lipid-dependent yeasts. It is associated with common skin diseases such as pityriasis versicolor and atopic dermatitis and can cause systemic infections in immunocompromised individuals. Owing to the slow growth and lipid requirements of these fastidious yeasts, convenient and reliable antifungal drug susceptibility testing assays for Malassezia spp. are not widely available. Therefore, we optimized a broth microdilution assay for the testing of Malassezia that is based on the CLSI and EUCAST assays for Candida and other yeasts. The addition of ingredients such as lipids and esculin provided a broth medium formulation that enabled the growth of all Malassezia spp. and could be read, with the colorimetric indicator resazurin, by visual and fluorescence readings. We tested the susceptibility of 52 strains of 13 Malassezia species to 11 commonly used antifungals. MIC values determined by visual readings were in good agreement with MIC values determined by fluorescence readings. The lowest MICs were found for the azoles itraconazole, posaconazole, and voriconazole, with MIC90 values of 0.03 to 1.0 μg/ml, 0.06 to 0.5 μg/ml, and 0.03 to 2.0 μg/ml, respectively. All Malassezia spp. were resistant to echinocandins and griseofulvin. Some Malassezia spp. also showed high MIC values for ketoconazole, which is the most widely recommended topical antifungal to treat Malassezia skin infections. In summary, our assay enables the fast and reliable susceptibility testing of Malassezia spp. with a large panel of different antifungals. PMID:28381607

Comparative study of the in vitro activity of various antifungal drugs against Scedosporium spp. in aerobic and hyperbaric atmosphere versus normal atmosphere.

PubMed

Farina, C; Marchesi, G; Passera, M; Diliberto, C; Russello, G

2012-06-01

Scedosporium spp. have been observed with increasing frequency over the last decade in immunocompromised patients and trauma patients. This mould is often multi-drug resistant and its mortality rate remains very high. The primary goal of this study was to obtain data concerning the in vitro susceptibility of 13 Scedosporium strains comparing the in vitro incubation in aerobic versus hyperbaric conditions. Chemosensitivity of thirteen Scedosporium strains was evaluated after a 72h-incubation in a normoxic (21% O2) normobaric (1 ATA) atmosphere versus a hyperoxic (100% O2) hyperbaric (2-3 ATA), and after a re-incubation at room temperature for an additional 72h. All S. apiospermum and S. prolificans strains showed no growth after incubation in hyperbaric hyperoxic atmosphere. However, when plates were then maintained at room temperature in aerobic conditions, growth was systematically observed from 36 to 96h, and Minimal inhibitory concentration (MIC) values were the same obtained after incubation in aerobic conditions. These results suggest impressive in vitro fungistatic activity of the hyperoxic hyperbaric atmosphere, even if its effect is strictly time-dependent. This preliminary in vitro study has potential clinical relevance because it focuses on examining in vitro combination therapy using hyperoxic hyperbaric conditions plus a single antifungal agent, rather than using combinations of different antifungal drugs, to potentially increase the antifungal activity. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Molecular Identification, Antifungal Susceptibility Profile, and Biofilm Formation of Clinical and Environmental Rhodotorula Species Isolates

PubMed Central

Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona e

2013-01-01

Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC50/MIC90, 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula species

Molecular identification, antifungal susceptibility profile, and biofilm formation of clinical and environmental Rhodotorula species isolates.

PubMed

Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona E; Colombo, Arnaldo Lopes

2013-01-01

Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC(50)/MIC(90), 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula

In Vitro Activity of E1210, a Novel Antifungal, against Clinically Important Yeasts and Molds▿

PubMed Central

Miyazaki, Mamiko; Horii, Takaaki; Hata, Katsura; Watanabe, Nao-aki; Nakamoto, Kazutaka; Tanaka, Keigo; Shirotori, Syuji; Murai, Norio; Inoue, Satoshi; Matsukura, Masayuki; Abe, Shinya; Yoshimatsu, Kentaro; Asada, Makoto

2011-01-01

E1210 is a new antifungal compound with a novel mechanism of action and broad spectrum of antifungal activity. We investigated the in vitro antifungal activities of E1210 compared to those of fluconazole, itraconazole, voriconazole, amphotericin B, and micafungin against clinical fungal isolates. E1210 showed potent activities against most Candida spp. (MIC90 of ≤0.008 to 0.06 μg/ml), except for Candida krusei (MICs of 2 to >32 μg/ml). E1210 showed equally potent activities against fluconazole-resistant and fluconazole-susceptible Candida strains. E1210 also had potent activities against various filamentous fungi, including Aspergillus fumigatus (MIC90 of 0.13 μg/ml). E1210 was also active against Fusarium solani and some black molds. Of note, E1210 showed the greatest activities against Pseudallescheria boydii (MICs of 0.03 to 0.13 μg/ml), Scedosporium prolificans (MIC of 0.03 μg/ml), and Paecilomyces lilacinus (MICs of 0.06 μg/ml) among the compounds tested. The antifungal action of E1210 was fungistatic, but E1210 showed no trailing growth of Candida albicans, which has often been observed with fluconazole. In a cytotoxicity assay using human HK-2 cells, E1210 showed toxicity as low as that of fluconazole. Based on these results, E1210 is likely to be a promising antifungal agent for the treatment of invasive fungal infections. PMID:21825291

Antifungal Susceptibility Testing of Fluconazole by Flow Cytometry Correlates with Clinical Outcome

PubMed Central

Wenisch, Christoph; Moore, Caroline B.; Krause, Robert; Presterl, Elisabeth; Pichna, Peter; Denning, David W.

2001-01-01

Susceptibility testing of fungi by flow cytometry (also called fluorescence-activated cell sorting [FACS]) using vital staining with FUN-1 showed a good correlation with the standard M27-A procedure for assessing MICs. In this study we determined MICs for blood culture isolates from patients with candidemia by NCCLS M27-A and FACS methods and correlated the clinical outcome of these patients with in vitro antifungal resistance test results. A total of 24 patients with candidemia for whom one or more blood cultures were positive for a Candida sp. were included. Susceptibility testing was performed by NCCLS M27-A and FACS methods. The correlation of MICs (NCCLS M27-A and FACS) and clinical outcome was calculated. In 83% of the cases, the MICs of fluconazole determined by FACS were within 1 dilution of the MICs determined by the NCCLS M27-A method. For proposed susceptibility breakpoints, there was 100% agreement between the M27-A and FACS methods. In the FACS assay, a fluconazole MIC of <1 μg/ml was associated with cure (P < 0.001) whereas an MIC of ≥1 μg/ml was associated with death (P < 0.001). The M27-A-derived fluconazole MICs did not correlate with outcome (P = 1 and P = 0.133). PMID:11427554

Process Analysis of Variables for Standardization of Antifungal Susceptibility Testing of Nonfermentative Yeasts ▿

PubMed Central

Zaragoza, Oscar; Mesa-Arango, Ana C.; Gómez-López, Alicia; Bernal-Martínez, Leticia; Rodríguez-Tudela, Juan Luis; Cuenca-Estrella, Manuel

2011-01-01

Nonfermentative yeasts, such as Cryptococcus spp., have emerged as fungal pathogens during the last few years. However, standard methods to measure their antifungal susceptibility (antifungal susceptibility testing [AST]) are not completely reliable due to the impaired growth of these yeasts in standard media. In this work, we have compared the growth kinetics and the antifungal susceptibilities of representative species of nonfermentative yeasts such as Cryptococcus neoformans, Cryptococcus gattii, Cryptococcus albidus, Rhodotorula spp., Yarrowia lipolytica, Geotrichum spp., and Trichosporon spp. The effect of the growth medium (RPMI medium versus yeast nitrogen base [YNB]), glucose concentration (0.2% versus 2%), nitrogen source (ammonium sulfate), temperature (30°C versus 35°C), shaking, and inoculum size (103, 104, and 105 cells) were analyzed. The growth rate, lag phase, and maximum optical density were obtained from each growth experiment, and after multivariate analysis, YNB-based media demonstrated a significant improvement in the growth of yeasts. Shaking, an inoculum size of 105 CFU/ml, and incubation at 30°C also improved the growth kinetics of organisms. Supplementation with ammonium sulfate and with 2% glucose did not have any effect on growth. We also tested the antifungal susceptibilities of all the isolates by the reference methods of the CLSI and EUCAST, the EUCAST method with shaking, YNB under static conditions, and YNB with shaking. MIC values obtained under different conditions showed high percentages of agreement and significant correlation coefficient values between them. MIC value determinations according to CLSI and EUCAST standards were rather complicated, since more than half of isolates tested showed a limited growth index, hampering endpoint determinations. We conclude that AST conditions including YNB as an assay medium, agitation of the plates, reading after 48 h of incubation, an inoculum size of 105 CFU/ml, and incubation at 30�

Species diversity of Aspergillus section Versicolores in clinical samples and antifungal susceptibility.

PubMed

Siqueira, João Paulo Zen; Sutton, Deanna A; García, Dania; Gené, Josepa; Thomson, Pamela; Wiederhold, Nathan; Guarro, Josep

2016-11-01

Aspergillus section Versicolores includes species of clinical relevance and many others that have been poorly studied but are occasionally found in clinical samples. The aim of this study was to investigate, using a multilocus phylogenetic approach, the spectrum of species of the section Versicolores and to determine their in vitro antifungal susceptibility. The study was based on a set of 77 clinical isolates from different USA medical centres, which had been previously identified as belonging to this section. The genetic markers used were internal transcribed spacer (ITS), β-tubulin (BenA), calmodulin (CaM), and RNA polymerase II second largest subunit (RPB2), and the drugs tested, following the CLSI guidelines, were amphotericin B (AMB), itraconazole, posaconazole, voriconazole, anidulafungin, caspofungin, micafungin, terbinafine (TBF), and flucytosine (5FC). The most frequent species were Aspergillus sydowii (26 %), Aspergillus creber (22 %), and Aspergillus amoenus (18.2 %), followed by Aspergillus protuberus (13 %), Aspergillus jensenii (10.4 %), and Aspergillus tabacinus (5.2 %); while Aspergillus cvjetkovicii, Aspergillus fructus, Aspergillus puulaauensis, and Aspergillus versicolor were represented by only one isolate each (1.3 %). This is the first time that A. jensenii and A. puulaauensis have been reported from clinical samples. Considering the high number of isolates identified as belonging to this fungal group in this study, its clinical relevance should not be overlooked. Aspergillus versicolor, traditionally considered one of the most common species in this section in a clinical setting, was only rarely recovered in our study. The in vitro antifungal results showed that echinocandins and TBF were the most potent drugs, the azoles showed variable results, AMB was poorly active, and 5FC was the less active. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

In vitro susceptibility of Sporothrix brasiliensis: Comparison of yeast and mycelial phases.

PubMed

Sanchotene, Karine Ortiz; Brandolt, Tchana Martinez; Klafke, Gabriel Baracy; Poester, Vanice Rodrigues; Xavier, Melissa Orzechowski

2017-11-01

Sporothrix brasiliensis has emerged as an important cause of sporotrichosis, particularly associated with feline and zoonotic cases. Owing to the paucity of data on antifungal activity against this species, the present study aimed to evaluate the in vitro susceptibility of clinical isolates of S. brasiliensis in the mycelial and yeast phases to itraconazole (ITZ), terbinafine (TRB), and amphotericin B (AMB). Thirty-five isolates from an outbreak of feline sporotrichosis in Southern Brazil were used. All of them were assessed in the yeast and filamentous phases using the broth microdilution technique in accordance with the respective reference protocols M27-A3 and M38-A2 of the Clinical and Laboratory Standards Institute (CLSI). In our study, TRB was the most active antifungal against both the filamentous and yeast phases, showing GM of the MIC of 0.343 μg/ml and 0.127 μg/ml, respectively. In the yeast phase, the GM of the MIC for TRB was significantly lower than that for both ITZ (P = .009) and AMB (P < .001). However, in the filamentous phase, the GM of the MIC for TRB was significantly lower than that of AMB (P < .001), but not different from that of ITZ (P = .091). AMB was the antifungal with the highest GM of the MIC for both phases (1.486 μg/ml for the filamentous phase and 0.660 μg/ml for the yeast). Our results may contribute to a better understanding of antifungal susceptibility profiles of clinical isolates of S. brasiliensis in the mycelial and yeast phases in further studies. © The Author 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

In vitro susceptibility and multilocus sequence typing of Fusarium isolates causing keratitis.

PubMed

Dallé da Rosa, P; Nunes, A; Borges, R; Batista, B; Meneghello Fuentefria, A; Goldani, L Z

2018-05-17

Fungal keratitis is recognized as a significant cause of ocular morbidity and blindness especially in developing countries. In this study, we aimed to present the molecular identification and susceptibility of Fusarium isolates causing fungal keratitis in a university hospital in southern Brazil. The samples were identified using the second largest subunit of the RNA polymerase gene (RPB2) and the translation elongation factor 1-alpha (TEF1), while the antifungal susceptibility was tested by the broth microdilution method according to the Clinical and Laboratory Standards Institute (CLSI) methodology. The majority of the isolates belonged to the Fusarium solani species complex (F. solani, F. keratoplasticum and F. falciforme) and Fusarium oxysporum species complex. Antifungal susceptibility has shown that amphotericin B and natamycin were the most effective antifungals across all isolates, followed by voriconazole. Variation among Fusarium complexes in their antifungal sensitivities was observed in our study. The identification of Fusarium species from human samples is important not only from an epidemiological viewpoint, but also for choosing the appropriate antifungal agent for difficult-to-treat Fusarium infections such as keratitis. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Multilocus Phylogeny and Antifungal Susceptibility of Aspergillus Section Circumdati from Clinical Samples and Description of A. pseudosclerotiorum sp. nov.

PubMed Central

Siqueira, J. P. Z.; Sutton, D. A.; García, D.; Wiederhold, N.; Peterson, S. W.; Guarro, J.

2017-01-01

ABSTRACT A multilocus phylogenetic study was carried out to assess species identity of a set of 34 clinical isolates from Aspergillus section Circumdati from the United States and to determine their in vitro antifungal susceptibility against eight antifungal drugs. The genetic markers used were the internal transcribed spacer (ITS) region, and fragments of the beta-tubulin (BenA), calmodulin (CaM), and RNA polymerase II second largest subunit (RPB2) genes. The drugs tested were amphotericin B, itraconazole, posaconazole, voriconazole, anidulafungin, caspofungin, micafungin, and terbinafine. The most common species sampled was A. westerdijkiae (29.4%), followed by a novel species, which was described here as A. pseudosclerotiorum (23.5%). Other species identified were A. sclerotiorum (17.6%), A. ochraceus (8.8%), A. subramanianii (8.8%), and A. insulicola and A. ochraceopetaliformis, with two isolates (5.9%) of each. The drugs that showed the most potent activity were caspofungin, micafungin, and terbinafine, while amphotericin B showed the least activity. PMID:28053212

Multilocus Phylogeny and Antifungal Susceptibility of Aspergillus Section Circumdati from Clinical Samples and Description of A. pseudosclerotiorum sp. nov.

PubMed

Siqueira, J P Z; Sutton, D A; Gené, J; García, D; Wiederhold, N; Peterson, S W; Guarro, J

2017-03-01

A multilocus phylogenetic study was carried out to assess species identity of a set of 34 clinical isolates from Aspergillus section Circumdati from the United States and to determine their in vitro antifungal susceptibility against eight antifungal drugs. The genetic markers used were the internal transcribed spacer (ITS) region, and fragments of the beta-tubulin ( BenA ), calmodulin ( CaM ), and RNA polymerase II second largest subunit ( RPB2 ) genes. The drugs tested were amphotericin B, itraconazole, posaconazole, voriconazole, anidulafungin, caspofungin, micafungin, and terbinafine. The most common species sampled was A. westerdijkiae (29.4%), followed by a novel species, which was described here as A. pseudosclerotiorum (23.5%). Other species identified were A. sclerotiorum (17.6%), A. ochraceus (8.8%), A. subramanianii (8.8%), and A. insulicola and A. ochraceopetaliformis , with two isolates (5.9%) of each. The drugs that showed the most potent activity were caspofungin, micafungin, and terbinafine, while amphotericin B showed the least activity. Copyright © 2017 American Society for Microbiology.

Epidemiology and antifungal susceptibilities of yeast isolates causing invasive infections across urban Beijing, China.

PubMed

Guo, Li-Na; Xiao, Meng; Cao, Bin; Qu, Fen; Zhan, Yu-Liang; Hu, Yun-Jian; Wang, Xin-Ru; Liang, Guo-Wei; Gu, Hai-Tong; Qi, Jun; Yuan, Hui; Min, Rong; Wang, Fei-Yan; Liu, Lin-Juan; Wang, Hai-Bin; Jiang, Wei; Duan, Xue-Guang; Xu, Wen-Jian; Yu, Yan-Hua; Su, Jian-Rong; Zhang, Jian-Zhong; Nong, Jin-Qing; Liu, Shu-Mei; Li, Jun; Liu, Jun-Ting; Yue, Zhi-Gang; Yang, Duo; Guo, Jie; Zhao, Rui; Zhang, Ya-Nan; Yang, Xi-Ming; Liu, Xiao-Qing; Hsueh, Po-Ren; Xu, Ying-Chun

2017-09-01

To investigate the species distribution and antifungal susceptibility profiles of yeast isolates causing invasive infections across Beijing. A total of 1201 yeast isolates recovered from blood and other sterile body fluids were correctly identified by matrix-assisted laser desorption/ionization TOF MS supplemented by DNA sequencing. Antifungal susceptibility testing was performed according to the Clinical and Laboratory Standards Institute broth microdilution method. Candida (95.5%) remained the most common yeast species isolated; Candida albicans (38.8%) and Candida parapsilosis (22.6%) were the leading species of candidemia. Azole resistances were mainly observed in Candida glabrata and Candida tropicalis isolates. This study outlined the epidemiologic data of invasive yeast infections and highlighted the need for continuous monitoring of azole resistances among C. glabrata and C. tropicalis isolates in Beijing.

In vitro susceptibility testing of Aspergillus spp. against voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin.

PubMed

Shi, Jun-yan; Xu, Ying-chun; Shi, Yi; Lü, Huo-xiang; Liu, Yong; Zhao, Wang-sheng; Chen, Dong-mei; Xi, Li-yan; Zhou, Xin; Wang, He; Guo, Li-na

2010-10-01

During recent years, the incidence of serious infections caused by opportunistic fungi has increased dramatically due to alterations of the immune status of patients with hematological diseases, malignant tumors, transplantations and so forth. Unfortunately, the wide use of triazole antifungal agents to treat these infections has lead to the emergence of Aspergillus spp. resistant to triazoles. The present study was to assess the in vitro activities of five antifungal agents (voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin) against different kinds of Aspergillus spp. that are commonly encountered in the clinical setting. The agar-based Etest MIC method was employed. One hundred and seven strains of Aspergillus spp. (5 species) were collected and prepared according to Etest Technique Manuel. Etest MICs were determined with RPMI agar containing 2% glucose and were read after incubation for 48 hours at 35°C. MIC(50), MIC(90) and MIC range were acquired by Whonet 5.4 software. The MIC(90) of caspofungin against A. fumigatus, A. flavus and A. nidulans was 0.094 µg/ml whereas the MIC(90) against A. niger was 0.19 µg/ml. For these four species, the MIC(90) of caspofungin was the lowest among the five antifungal agents. For A. terrus, the MIC(90) of posaconazole was the lowest. For A. fumigatus and A. flavus, the MIC(90) in order of increasing was caspofungin, posaconazole, voriconazole, itraconazole, and amphotericin B. The MIC of amphotericin B against A. terrus was higher than 32 µg/ml in all 7 strains tested. The in vitro antifungal susceptibility test shows the new drug caspofungin, which is a kind of echinocandins, has good activity against the five species of Aspergillus spp. and all the triazoles tested have better in vitro activity than traditional amphotericin B.

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

PubMed

Maphanga, Tsidiso G; Britz, Erika; Zulu, Thokozile G; Mpembe, Ruth S; Naicker, Serisha D; Schwartz, Ilan S; Govender, Nelesh P

2017-06-01

Disseminated emmonsiosis is an important AIDS-related mycosis in South Africa that is caused by Emergomyces africanus , a newly described and renamed dimorphic fungal pathogen. In vitro antifungal 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 unique E. africanus isolates 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 limited in vitro activity. 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 vitro susceptibility data support the management of disseminated emmonsiosis with amphotericin B, followed by itraconazole, voriconazole, or posaconazole. Fluconazole was a relatively less potent agent. Copyright © 2017 American Society for Microbiology.

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

PubMed Central

Britz, Erika; Zulu, Thokozile G.; Mpembe, Ruth S.; Naicker, Serisha D.; Schwartz, Ilan S.

2017-01-01

ABSTRACT Disseminated emmonsiosis is an important AIDS-related mycosis in South Africa that is caused by Emergomyces africanus, a newly described and renamed dimorphic fungal pathogen. In vitro antifungal 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 unique E. africanus isolates 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 limited in vitro activity. 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 vitro susceptibility data support the management of disseminated emmonsiosis with amphotericin B, followed by itraconazole, voriconazole, or posaconazole. Fluconazole was a relatively less potent agent. PMID:28356416

In vitro antifungal activity of coumarin extracted from Loeselia mexicana Brand.

PubMed

Navarro-García, Victor M; Rojas, Gabriela; Avilés, Margarita; Fuentes, Macrina; Zepeda, Gerardo

2011-09-01

The bis-coumarin daphnoretin and its monomeric precursors scopoletin and umbelliferone were isolated for the first time from the aerial part of Loeselia mexicana Brand (a vegetal species used in Mexican traditional medicine) using chromatographic techniques. The structures of these compounds were determined by (1) H and (13) C NMR analyses. These coumarins were evaluated for in vitro antifungal activity. The three compounds tested showed significant antifungal activity. © 2011 Blackwell Verlag GmbH.

Microscopic Evaluation, Molecular Identification, Antifungal Susceptibility, and Clinical Outcomes in Fusarium, Aspergillus and, Dematiaceous Keratitis

PubMed Central

Gajjar, Devarshi U.; Pal, Anuradha K.; Ghodadra, Bharat K.; Vasavada, Abhay R.

2013-01-01

Purpose. Fusarium, Aspergillus, and Dematiaceous are the most common fungal species causing keratitis in tropical countries. Herein we report a prospective study on fungal keratitis caused by these three fungal species. Methodology. A prospective investigation was undertaken to evaluate eyes with presumed fungal keratitis. All the fungal isolates (n = 73) obtained from keratitis infections were identified using morphological and microscopic characters. Molecular identification using sequencing of the ITS region and antifungal susceptibility tests using microdilution method were done. The final clinical outcome was evaluated in terms of the time taken for resolution of keratitis and the final visual outcome. The results were analyzed after segregating the cases into three groups, namely, Fusarium, Aspergillus, and Dematiaceous keratitis. Results. Diagnosis of fungal keratitis was established in 73 (35.9%) cases out of 208 cases. The spectra of fungi isolated were Fusarium spp. (26.6%), Aspergillus spp. (21.6%), and Dematiaceous fungi (11.6%). The sequence of the ITS region could identify the Fusarium and Aspergillus species at the species complex level, and the Dematiaceous isolates were accurately identified. Using antifungal agents such as fluconazole, natamycin, amphotericin B, and itraconazole, the minimum inhibitory concentrations (MICs) for Fusarium spp. were >32 μg/mL, 4–8 μg/mL, 0.5–1 μg/mL, and >32 μg/mL, respectively. Antifungal susceptibility data showed that Curvularia spp. was highly resistant to all the antifungal agents. Overall, natamycin and amphotericin B were found to be the most effective antifungal agents. The comparative clinical outcomes in all cases showed that the healing response in terms of visual acuity of the Dematiaceous group was significantly good when compared with the Fusarium and Aspergillus groups (P < 0.05). The time required for healing in the Fusarium group was statistically significantly less when compared with

Species spectrum and antifungal susceptibility profile of vaginal isolates of Candida in Kuwait.

PubMed

Alfouzan, W; Dhar, R; Ashkanani, H; Gupta, M; Rachel, C; Khan, Z U

2015-03-01

The study was undertaken to determine the prevalence of vulvovaginal candidiasis (VVC) among patients with vaginitis, frequency of different Candida species, and their susceptibility profile. Over six months period, high vaginal swabs were cultured on Sabouraud's dextrose agar and isolates were identified by culture on CHROMagar Candida and Vitek2 yeast identification system or/and API 20C (BioMerieux, France). Antifungal susceptibility of the Candida isolates was determined by E-test against amphotericin B, flucytosine, fluconazole, voriconazole, posaconazole and caspofungin. One thousand seven hundred and fifty-two women with vaginitis were screened for the prevalence of Candida spp. Vaginal swab cultures of 231 (13.2%) women yielded Candida spp. The isolation rates of different species were as follows: Candida albicans (73.9%), Candida glabrata (19.8%), Candida kefir (1.94%), Candida tropicalis (0.96%), Candida parapsilosis (0.96%), Candida krusei (0.96%), Candida guilliermondii (0.96%), and Saccharomyces cerevisiae (0.52%). All strains of C. albicans and non-C. albicans were susceptible to most of the antifungal agents tested. The high frequency with which C. albicans was recovered and its azole susceptibility support the continued use of azole agents for empirical therapy of uncomplicated VVC. However, a larger controlled study is required to determine the role of non-C. albicans in recurrent VVC. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Antifungal susceptibility profile of diferent yeasts isolates from wild animals, cow's milk with subclinical mastitis and hospital environment.

PubMed

Mendes, J F; Gonçalves, C L; Ferreira, G F; Esteves, I A; Freitas, C H; Villarreal, J P V; Mello, J R B; Meireles, M C A; Nascente, P S

2018-02-01

Yeast infections have acquired great importance due to increasing frequency in immunocompromised patients or patients undergoing invasive diagnostic and therapeutic techniques, and also because of its high morbidity and mortality. At the same time, it has been seen an increase in the emergence of new pathogenic species difficult to diagnose and treat. The aim of this study was to determine the in vitro susceptibility of 89 yeasts from different sources against the antifungals amphotericin B, voriconazole, fluconazole and flucytosine, using the VITEK® 2 Compact system. The antifungal susceptibility was performed automatically by the Vitek® 2 Compact system. The origin of the yeasts was: Group 1 - microbiota of wild animals (W) (26/89), 2 - cow's milk with subclinical mastitis (M) (27/89) and 3 - hospital enviorment (H) (36/89). Of the 89 yeasts submitted to the Vitek® 2 test, 25 (20.9%) were resistant to fluconazole, 11 (12.36%) to amphotericin B, 3 (3.37%) to voriconazole, and no sample was resistant to flucytosine. Regarding the minimum inhibitory concentration (MIC), fluconazole showed an MIC between 1 and 64 mg/mL for the three groups, voriconazole had an MIC between 0.12 and 8 mg/mL, amphotericin B had an MIC between 0.25 and 4 mg/mL for group H and group W respectively, between 0.25 and 16 mg/mL for group M and flucytosine had an MIC equal to 1μg/mL for all groups. The yeasts isolated from the H group showed the highest resistance to fluconazole 12/89 (13.49%), followed by group W (7.87%) and group M (5.62%). The more resistant group to voriconazole was followed by the M and H groups, the W group showed no resistance to this antifungal. Group H was the least resistant (2.25%) to amphotericin.

Prevalence and epidemiology of tinea pedis and toenail onychomycosis and antifungal susceptibility of the causative agents in patients with type 2 diabetes in Turkey.

PubMed

Oz, Yasemin; Qoraan, Iman; Oz, Ali; Balta, Ilknur

2017-01-01

Diabetes patients are particularly susceptible to fungal infections because their vascular and immunological systems are compromised. The present study aimed to determine prevalences of tinea pedis and onychomycosis, factors predisposing to their development, and antifungal susceptibilities of causative fungal species against fluconazole, itraconazole, and terbinafine in patients with type 2 diabetes mellitus (DM). Study groups were defined according to hemoglobin A1C rates of ≥6.5% for the diabetes group and ≤5.7% for control subjects. A total of 600 diabetes subjects and 152 control subjects were evaluated. Rates of onychomycosis and tinea pedis in diabetes patients, and associations with age, gender, blood glucose level, duration of diabetes and serum lipid profile were investigated, as were the distribution and antifungal susceptibility of agents isolated. Patients with onychomycosis and/or tinea pedis numbered 85 in the diabetes group and nine in the control group (P = 0.006). The development of onychomycosis or tinea pedis was significantly related to increasing age and male gender. Although the most common agents were dermatophytes, non-dermatophyte fungal isolates were not uncommon. Terbinafine was the most effective drug against dermatophytes but was invalid for non-dermatophyte isolates by in vitro antifungal susceptibility testing. The development of onychomycosis or tinea pedis was significantly related to type 2 DM, increasing age, and male gender. The most common isolate was Trichophyton rubrum. The isolation and identification of the fungus is important to the effective management of tinea pedis and onychomycosis in diabetes patients because non-dermatophyte fungi can cause these infections. © 2016 The International Society of Dermatology.

Posaconazole exhibits in vitro and in vivo synergistic antifungal activity with caspofungin or FK506 against Candida albicans.

PubMed

Chen, Ying-Lien; Lehman, Virginia N; Averette, Anna F; Perfect, John R; Heitman, Joseph

2013-01-01

The object of this study was to test whether posaconazole, a broad-spectrum antifungal agent inhibiting ergosterol biosynthesis, exhibits synergy with the β-1,3 glucan synthase inhibitor caspofungin or the calcineurin inhibitor FK506 against the human fungal pathogen Candida albicans. Although current drug treatments for Candida infection are often efficacious, the available antifungal armamentarium may not be keeping pace with the increasing incidence of drug resistant strains. The development of drug combinations or novel antifungal drugs to address emerging drug resistance is therefore of general importance. Combination drug therapies are employed to treat patients with HIV, cancer, or tuberculosis, and has considerable promise in the treatment of fungal infections like cryptococcal meningitis and C. albicans infections. Our studies reported here demonstrate that posaconazole exhibits in vitro synergy with caspofungin or FK506 against drug susceptible or resistant C. albicans strains. Furthermore, these combinations also show in vivo synergy against C. albicans strain SC5314 and its derived echinocandin-resistant mutants, which harbor an S645Y mutation in the CaFks1 β-1,3 glucan synthase drug target, suggesting potential therapeutic applicability for these combinations in the future.

Antifungal activity of low molecular weight chitosan against clinical isolates of Candida spp.

PubMed

Alburquenque, Claudio; Bucarey, Sergio A; Neira-Carrillo, Andrónico; Urzúa, Blanca; Hermosilla, Germán; Tapia, Cecilia V

2010-12-01

Chitosan is a natural polymer derived from chitin, a structural component of fungi, insects and shrimp, which exerts antimicrobial effects against bacteria and fungi. The aim of this study was to investigate the in vitro antifungal activity of low molecular weight chitosan (LMWC), and the potential synergy between chitosan and a currently used antifungal drug, fluconazole. The in vitro minimal inhibitory concentrations (MICs) of chitosan and fluconazole against 105 clinical Candida isolates were measured by the broth microdilution method. LMWC exhibited a significant antifungal activity, inhibiting over 89.9% of the clinical isolates examined (68.6% of which was completely inhibited). The species included several fluconazole-resistant strains and less susceptible species such as C. glabrata, which was inhibited at a concentration of 4.8 mg/l LMWC. Although some strains were susceptible at pH 7.0, a greater antifungal activity of LMWC was observed at pH 4.0. There was no evidence of a synergistic effect of the combination of LMWC and fluconazole at pH 7.0. This is the first report in which the antifungal activity of LMWC was investigated with clinical Candida strains. The use of LMWC as an antifungal compound opens new therapeutic perspectives, as the low toxicity of LMWC in humans supports its use in new applications in an environment of pH 4.0-4.5, such as a topical agent for vulvovaginal candidiasis.

SUSCEPTIBILITY TEST FOR FUNGI: CLINICAL AND LABORATORIAL CORRELATIONS IN MEDICAL MYCOLOGY.

PubMed

Alastruey-Izquierdo, Ana; Melhem, Marcia S C; Bonfietti, Lucas X; Rodriguez-Tudela, Juan L

2015-09-01

During recent decades, antifungal susceptibility testing has become standardized and nowadays has the same role of the antibacterial susceptibility testing in microbiology laboratories. American and European standards have been developed, as well as equivalent commercial systems which are more appropriate for clinical laboratories. The detection of resistant strains by means of these systems has allowed the study and understanding of the molecular basis and the mechanisms of resistance of fungal species to antifungal agents. In addition, many studies on the correlation of in vitro results with the outcome of patients have been performed, reaching the conclusion that infections caused by resistant strains have worse outcome than those caused by susceptible fungal isolates. These studies have allowed the development of interpretative breakpoints for Candida spp. and Aspergillus spp., the most frequent agents of fungal infections in the world. In summary, antifungal susceptibility tests have become essential tools to guide the treatment of fungal diseases, to know the local and global disease epidemiology, and to identify resistance to antifungals.

Addition of DNase Improves the In Vitro Activity of Antifungal Drugs against Candida albicans Biofilms

PubMed Central

Martins, Margarida; Henriques, Mariana; Lopez-Ribot, José L.; Oliveira, Rosário

2011-01-01

SUMMARY Background Cells within Candida albicans biofilms display decreased susceptibility to most clinically used antifungal agents. We recently demonstrated that extracellular DNA (eDNA) plays an important role in biofilm integrity, as a component of the biofilm matrix. Objective To gain insight into the contributions of eDNA to C. albicans biofilms antifungal susceptibility by the investigation of the impact of the combined use of deoxyribonuclease I (DNase) and antifungals to treat biofilms. Methods C. albicans biofilms were formed using a simple and reproducible 96-well plate-based method. The activity of the combined use of 0.13 mg l−1 DNase and antifungals was estimated by the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) reduction assay, and total viable counts. Results and Conclusions Here we report the improved efficacy of amphotericin B when in combination with DNase against C. albicans biofilms, as assessed by XTT readings and viable counts. Furthermore, although DNase increased the efficacy of caspofungin in the reduction of mitochondrial activity, no changes were observed in terms of culturable cells. DNase did not affect biofilm cells susceptibility to fluconazole. This work suggests that agents that target processes affecting the biofilm structural integrity may have potential use as adjuvants of a catheter–lock therapy. PMID:21668524

[INVESTIGATION ON ANTIFUNGAL SUSCEPTIBILITY OF CANDIDA YEASTS IN PREGNANT PATIENTS WITH CONFIRMED VULVOVAGINAL CANDIDIASIS AND THEIR NEWBORNS.

PubMed

Chokoeva, A; Kouzmanov, A; Ivanova, Z; Zisova, L; Amalie, G; Petleshkova, P; Miteva-Katrandzhieva, Ts; Krasteva, M; Uchikova, E

Background Vulvovaginal candidiasis (VVU) is considered as a special risk factor during pregnancy, with important influence on the reproductive function of the patients and on the morbidity in the newborns from mothers with VVC. Maternal VVC is a major risk factor for the development of candida-colonization of the infant, which in turn is the first step towards the development of mucocutaneous or systemic candidiasis and Candida-septicemia in the newborn. In pregnant patients, the possible applicable local and systemic medications are limited, while the therapeutic resistance in chronic recurrent forms of VVC increases, facts that require precision of the diagnosic approach to optimize the therapeutic recommendations in pregnant patients, considered as a high risk group. The aim of this study was to investigate in vitro antifungal susceptibility of Candida yeasts to current antifungal agents in pregnant patients with confirmed VVC before the act of birth. Material and Methods Vaginal secretions of 23 healthy pregnant women with proven Candida vaginitis were taken within 48 hours before birth and the presence of yeasls of Candida was confirmed by culture examination. Between 47-72 hours after birth, samples were taken for Candida colonization of the oralmucosa and feces of their newborns. Samples were plated on Sabouraud agar and cultured in an incubator for 2 to 3 days at a temperature of 25° C. Species identification of the isolated yeasts were performed by commercial API Candida test - API 20C AUX (BioMerieux, Marcy-l'Etoile, France). Part of the isolates was identified by commercial whale AUXACOLOR (BioRad, Mames la Coquette, France). Antifungal sensitivity of isolated strains was examined by applying commercial solicitation ready kit and methods of disc diffusion and E-test, as the aim of the authors was to assess their potential for use in the diagnosis, and the correlation between them. Results Candida albicans was the prevalent etiological agent in pregnant

Antifungal Activity of Propolis Against Yeasts Isolated From Blood Culture: In Vitro Evaluation.

PubMed

Mutlu Sariguzel, Fatma; Berk, Elife; Koc, Ayes Nedret; Sav, Hafize; Demir, Gonca

2016-09-01

Due to the failure of available antifungal agents in the treatment of candidemia and the toxic activities of these drugs, a lot of researches are being conducted to develop new nontoxic and effective antifungal agents for optimal control of fungal pathogens. The aim of this study is to evaluate the in vitro antifungal activity of propolis against yeasts isolated from the blood cultures of intensive care unit patients. Seventy-six strains were included in this study. The in vitro antifungal activity of propolis, fluconazole (FLU), and itraconazole (ITR) was investigated by the microdilution broth methods (CLSI guidelines M27-A3 for yeast). The propolis sample was collected from Kayseri, Turkey. Of the 76 isolates, 33 were identified as Candida albicans while 37 were C. parapsilosis, three were C. tropicalis, and three were identified as C. glabrata. The geometric mean range for MIC (μg/ml) with regard to all isolates was 0.077 to 3 μg/ml for FLU and ITR, and 0.375 to 0.70 μg/ml for propolis. It was shown that propolis had significant antifungal activity against all Candida strains and the MIC range of propolis was determined as 0185 to 3 μg/ml. This study demonstrated that propolis had significant antifungal activity against yeasts isolated from blood culture compared with FLU and ITR. The propolis MIC in azole-resistant strains such as C. glabrata was found lower than the FLU MIC. © 2015 Wiley Periodicals, Inc.

Genotyping and antifungal susceptibility testing of multiple Malassezia pachydermatis isolates from otitis and dermatitis cases in pets: is it really worth the effort?

PubMed

Álvarez-Pérez, Sergio; García, Marta E; Peláez, Teresa; Blanco, José L

2016-01-01

A total of 216 colonies of Malassezia pachydermatis from 28 cases of fungal otitis or dermatitis in pets were genotyped by M13 fingerprinting and tested for antifungal susceptibility. A huge genetic diversity was found (157 M13 types in total), with all animals having a polyclonal pattern of infection (5.4 ± 1.5 genotypes/sample). Furthermore, analysis of molecular variance (AMOVA) revealed that most genetic diversity (44%) was found at the within sample level. In contrast, variability in antifungal susceptibility among isolates from the same sample was less important, with different M13 types displaying in most cases identical or very similar MIC results. Most isolates displayed high in vitro susceptibility to amphotericin B, terbinafine and all azoles tested except fluconazole, for which MIC values were always ≥4 μg/ml and a 26.9% of isolates displayed values ≥32 μg/ml. We conclude that although characterization of multiple yeast isolates results in a considerable increase in laboratory workload and expenses, it may help to get a better understanding of the epidemiology of M. pachydermatis in a given patient population. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Adhesion, biofilm formation, cell surface hydrophobicity, and antifungal planktonic susceptibility: relationship among Candida spp.

PubMed

Silva-Dias, Ana; Miranda, Isabel M; Branco, Joana; Monteiro-Soares, Matilde; Pina-Vaz, Cidália; Rodrigues, Acácio G

2015-01-01

We have performed the characterization of the adhesion profile, biofilm formation, cell surface hydrophobicity (CSH) and antifungal susceptibility of 184 Candida clinical isolates obtained from different human reservoirs. Adhesion was quantified using a flow cytometric assay and biofilm formation was evaluated using two methodologies: XTT and crystal violet assay. CSH was quantified with the microbial adhesion to hydrocarbons test while planktonic susceptibility was assessed accordingly the CLSI protocol for yeast M27-A3 S4. Yeast cells of non-albicans species exhibit increased ability to adhere and form biofilm. However, the correlation between adhesion and biofilm formation varied according to species and also with the methodology used for biofilm assessment. No association was found between strain's site of isolation or planktonic antifungal susceptibility and adhesion or biofilm formation. Finally CSH seemed to be a good predictor for biofilm formation but not for adhesion. Despite the marked variability registered intra and inter species, C. tropicalis and C. parapsilosis were the species exhibiting high adhesion profile. C. tropicalis, C. guilliermondii, and C. krusei revealed higher biofilm formation values in terms of biomass. C. parapsilosis was the species with lower biofilm metabolic activity.

Adhesion, biofilm formation, cell surface hydrophobicity, and antifungal planktonic susceptibility: relationship among Candida spp.

PubMed Central

Silva-Dias, Ana; Miranda, Isabel M.; Branco, Joana; Monteiro-Soares, Matilde; Pina-Vaz, Cidália; Rodrigues, Acácio G.

2015-01-01

We have performed the characterization of the adhesion profile, biofilm formation, cell surface hydrophobicity (CSH) and antifungal susceptibility of 184 Candida clinical isolates obtained from different human reservoirs. Adhesion was quantified using a flow cytometric assay and biofilm formation was evaluated using two methodologies: XTT and crystal violet assay. CSH was quantified with the microbial adhesion to hydrocarbons test while planktonic susceptibility was assessed accordingly the CLSI protocol for yeast M27-A3 S4. Yeast cells of non-albicans species exhibit increased ability to adhere and form biofilm. However, the correlation between adhesion and biofilm formation varied according to species and also with the methodology used for biofilm assessment. No association was found between strain's site of isolation or planktonic antifungal susceptibility and adhesion or biofilm formation. Finally CSH seemed to be a good predictor for biofilm formation but not for adhesion. Despite the marked variability registered intra and inter species, C. tropicalis and C. parapsilosis were the species exhibiting high adhesion profile. C. tropicalis, C. guilliermondii, and C. krusei revealed higher biofilm formation values in terms of biomass. C. parapsilosis was the species with lower biofilm metabolic activity. PMID:25814989

Roles of Calcineurin and Crz1 in Antifungal Susceptibility and Virulence of Candida glabrata▿

PubMed Central

Miyazaki, Taiga; Yamauchi, Shunsuke; Inamine, Tatsuo; Nagayoshi, Yosuke; Saijo, Tomomi; Izumikawa, Koichi; Seki, Masafumi; Kakeya, Hiroshi; Yamamoto, Yoshihiro; Yanagihara, Katsunori; Miyazaki, Yoshitsugu; Kohno, Shigeru

2010-01-01

A Candida glabrata calcineurin mutant exhibited increased susceptibility to both azole antifungal and cell wall-damaging agents and was also attenuated in virulence. Although a mutant lacking the downstream transcription factor Crz1 displayed a cell wall-associated phenotype intermediate to that of the calcineurin mutant and was modestly attenuated in virulence, it did not show increased azole susceptibility. These results suggest that calcineurin regulates both Crz1-dependent and -independent pathways depending on the type of stress. PMID:20100876

In vitro susceptibility of filamentous fungi to itraconazole, voriconazole and posaconazole by Clinical and Laboratory Standards Institute reference method and E-test.

PubMed

Kondori, N; Svensson, E; Mattsby-Baltzer, I

2011-09-01

The use of anti-fungal agents has increased dramatically in recent years and new drugs have been developed. Several methods are available for determinations of their specific biological activities, i.e. the standard method for minimum inhibitory concentration-determination is described in M-38 [Clinical and Laboratory Standards Institute document M-38 (CLSI M-38)]. However, alternative methods, such as the E-test, are currently available in Mycology laboratories. The susceptibilities of clinical isolates of Aspergillus spp. (n = 29), Fusarium spp. (n = 5), zygomycetes (n = 21) and Schizophyllum (n = 1) were determined for itraconazole, voriconazole and posaconazole, using the CLSI M-38-A broth dilution method and also by the E-test. A good overall agreement (83.7%) between the two methods for all drugs and organisms was observed. Analyses of voriconazole showed a better agreement (93%) between the methods than posaconazole and itraconazole (85% and 74% respectively). Aspergillus spp. were the most susceptible fungi to the anti-fungal agents tested in this study. Posaconazole was the most active drug against filamentous fungi in vitro, followed by itraconazole and voriconazole. The latter (voriconazole) demonstrated no significant in vitro activity against zygomycetes. © 2010 Blackwell Verlag GmbH.

Oropharyngeal candidiasis in head and neck cancer patients in Iran: Species identification, antifungal susceptibility and pathogenic characterization.

PubMed

Jahanshiri, Z; Manifar, S; Moosa, H; Asghari-Paskiabi, F; Mahmoodzadeh, H; Shams-Ghahfarokhi, M; Razzaghi-Abyaneh, M

2018-06-01

Oropharyngeal candidiasis (OPC) is the most frequent opportunistic fungal infection in head and neck cancer patients. This study was done to identify the Candida species, which cause OPC, and to evaluate their antifungal susceptibility pattern and pathogenic characteristics in Iranian head and neck cancer patients treated by radiotherapy. The oral clinical samples were determined by culturing on CHROMagar, carbohydrate assimilation and ITS sequencing methods. Biofilm formation, phospholipase and proteinase activity and antifungal susceptibility were examined too. Among 54 patients with confirmed OPC, 39 (72.22%) patients were male and 15 (27.77%) were female. The most frequently Candida species from a total of 60 isolates was C. albicans (53.3%), followed by C. tropicalis (21.66%), C. glabrata (15%), C. kefyr (5%) and C. dubliniensis (1.66%). All the isolates were high-producers of biofilm. All of Candida isolates were proteinase positive and 47 isolates (81.04%) represented phospholipase activity. The maximum and minimum rates of antifungal resistance belonged to ketoconazole (93.75% of C. albicans and 89.28% of Candida non-albicans) and fluconazole (62.50% and 42.85% of C. albicans and Candida non-albicans), respectively. The most effective antifungal against all candida isolates was fluconazole. Our data can estimate abundance of OPC in male and female head and neck cancer patients and is helpful to use effective strategies for antifungal treatment, prophylaxis, and preventive therapies in these patients. Copyright © 2018. Published by Elsevier Masson SAS.

Species distribution and antifungal susceptibility patterns of Candida isolates from a public tertiary teaching hospital in the Eastern Cape Province, South Africa.

PubMed

Mnge, P; Okeleye, B I; Vasaikar, S D; Apalata, T

2017-05-15

Candida species are the leading cause of invasive fungal infections, and over the past decade there has been an increased isolation of drug resistant Candida species. This study aimed to identify the species distribution of Candida isolates and to determine their unique antifungal susceptibility and resistance patterns. During a cross-sectional study, 209 Candida isolates (recovered from 206 clinical samples) were collected and their species distribution was determined using ChromAgar Candida. The Vitek-2 system (Biomerieux, South Africa) was used to determine minimum inhibitory concentrations (MICs) to azoles (fluconazole, voriconazole), echinocandins (caspofungin, micafungin), polyenes (amphotericin B) and flucytosine. Four species of Candida were isolated, of which C. albicans was the most frequent, isolated in 45.4% (95/209) of the isolates, followed by C. glabrata: 31.1% (65/209). The MICs of the different antifungal drugs varied amongst the species of Candida. From the 130 isolates tested for MICs, 90.77% (112/130) were susceptible to all antifungal drugs and 6.9% (9/130) of the isolates were multi-drug resistant. C. dubliniensis (n=2) isolates were susceptible to all the above mentioned antifungal drugs. There was no significant difference in species distribution amongst clinical specimens and between patients' genders (P>0.05). An increase in MIC values for fluconazole and flucytosine towards the resistance range was observed. To our knowledge, this is the first report on surveillance of Candida species distribution and antifungal susceptibility at a public tertiary teaching hospital in Eastern Cape, South Africa.

Multicentre Etest evaluation of in vitro activity of conventional antifungal drugs against European bovine mastitis Prototheca spp. isolates.

PubMed

Jagielski, Tomasz; Buzzini, Pietro; Lassa, Henryka; Malinowski, Edward; Branda, Eva; Turchetti, Benedetta; Polleichtner, Angela; Roesler, Uwe; Lagneau, Paul-Emile; Marques, Sara; Silva, Eliane; Thompson, Gertrude; Stachowiak, Radosław; Bielecki, Jacek

2012-08-01

Bovine mammary protothecosis is a serious pathology that entails high economic losses in the dairy industry. The disease, the frequency of which has recently been increasing worldwide, is caused by unicellular, achlorophyllous, yeast-like algae of two species: Prototheca zopfii and Prototheca blaschkeae. The objective of this study was to investigate the in vitro activity of a panel of conventional antifungal drugs against Prototheca spp. isolates. A total of 144 P. zopfii genotype 2 and P. blaschkeae strains isolated from milk of mastitic cows were subjected to drug susceptibility testing by Etest methodology. Five out of ten antifungal drugs tested exhibited no activity against Prototheca spp. isolates. The best activity against Prototheca spp. was demonstrated by amphotericin B (MIC₉₀ of 1.5 mg/L). The MICs differed significantly (P < 0.01) between P. zopfii genotype 2 and P. blaschkeae, with the latter species being more susceptible to amphotericin B and azoles. Marked differences (P < 0.05) in azole and amphotericin B activities were noted among Prototheca spp. isolates originating from different European countries. Based on the correlation coefficients, a considerable cross-interaction was found among MICs of azoles and between MICs of azoles and amphotericin B for Prototheca spp. (P < 0.03). This study represents the largest, cross-European evaluation of antifungal activity against Prototheca spp. to date. The activity of amphotericin B against Prototheca spp. validates its potential use as a therapeutic agent against bovine protothecosis. For laboratory testing of drug activity against Prototheca spp., the Etest method is encouraged, due to its technical simplicity, rapidity and high intra- and inter-laboratory reproducibility.

Comparison of susceptibility and transcription profile of the new antifungal hassallidin A with caspofungin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neuhof, Torsten; Seibold, Michael; Thewes, Sascha

This is First report on the antifungal effects of the new glycolipopeptide hassallidin A. Due to related molecular structure moieties between hassallidin A and the established antifungal drug caspofungin we assumed parallels in the effects on cell viability. Therefore we compared hassallidin A with caspofungin by antifungal susceptibility testing and by analysing the genome-wide transcriptional profile of Candida albicans. Furthermore, we examined modifications in ultracellular structure due to hassallidin A treatment by electron microscopy. Hassallidin A was found to be fungicidal against all tested Candida species and Cryptococcus neoformans isolates. MICs ranged from 4 to 8 {mu}g/ml, independently from themore » species. Electron microscopy revealed noticeable ultrastructural changes in C. albicans cells exposed to hassallidin A. Comparing the transcriptional profile of C. albicans cells treated with hassallidin A to that of cells exposed to caspofungin, only 20 genes were found to be similarly up- or down-regulated in both assays, while 227 genes were up- or down-regulated induced by hassallidin A specifically. Genes up-regulated in cells exposed to hassallidin A included metabolic and mitotic genes, while genes involved in DNA repair, vesicle docking, and membrane fusion were down-regulated. In summary, our data suggest that, although hassallidin A and caspofungin have similar structures, however, the effects on susceptibility and transcriptional response to yeasts seem to be different.« less

Antifungal activity of medicinal plant extracts; preliminary screening studies.

PubMed

Webster, Duncan; Taschereau, Pierre; Belland, René J; Sand, Crystal; Rennie, Robert P

2008-01-04

In the setting of HIV and organ transplantation, opportunistic fungal infections have become a common cause of morbidity and mortality. Thus antifungal therapy is playing a greater role in health care. Traditional plants are a valuable source of novel antifungals. To assess in vitro antifungal activity of aqueous plant extracts. The minimum inhibitory concentrations were determined for each extract in the setting of human pathogenic fungal isolates. Plants were harvested and identification verified. Aqueous extracts were obtained and antifungal susceptibilities determined using serial dilutional extracts with a standardized microdilution broth methodology. Twenty-three fungal isolates were cultured and exposed to the plant extracts. Five known antifungals were used as positive controls. Results were read at 48 and 72 h. Of the 14 plants analyzed, Fragaria virginiana Duchesne, Epilobium angustifolium L. and Potentilla simplex Michx. demonstrated strong antifungal potential overall. Fragaria virginiana had some degree of activity against all of the fungal pathogens. Alnus viridis DC., Betula alleghaniensis Britt. and Solidago gigantea Ait. also demonstrated a significant degree of activity against many of the yeast isolates. Fragaria virginiana, Epilobium angustifolium and Potentilla simplex demonstrate promising antifungal potential.

Phylogeny of the Clinically Relevant Species of the Emerging Fungus Trichoderma and Their Antifungal Susceptibilities

PubMed Central

Sandoval-Denis, Marcelo; Sutton, Deanna A.; Cano-Lira, José F.; Fothergill, Annette W.; Wiederhold, Nathan P.; Guarro, Josep

2014-01-01

A set of 73 isolates of the emerging fungus Trichoderma isolated from human and animal clinical specimens were characterized morphologically and molecularly using a multilocus sequence analysis that included the internal transcribed spacer (ITS) regions of the nuclear ribosomal DNA and fragments of the translation elongation factor 1 alpha (Tef1), endochitinase CHI18-5 (Chi18-5), and actin 1 (Act1) genes. The most frequent species was Trichoderma longibrachiatum (26%), followed by Trichoderma citrinoviride (18%), the Hypocrea lixii/Trichoderma harzianum species complex (15%), the newly described species Trichoderma bissettii (12%), and Trichoderma orientale (11%). The most common anatomical sites of isolation in human clinical specimens were the respiratory tract (40%), followed by deep tissue (30%) and superficial tissues (26%), while all the animal-associated isolates were obtained from superficial tissue samples. Susceptibilities of the isolates to eight antifungal drugs in vitro showed mostly high MICs, except for voriconazole and the echinocandins. PMID:24719448

In vitro susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole and the correlation between triazoles susceptibility: Results from a five-year study.

PubMed

Lei, J; Xu, J; Wang, T

2018-06-01

Candida spp. is a common cause of invasive fungal disease. The aim of this study was to examine the susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole and explore the correlation between triazoles susceptibility. The antifungal susceptibility in the present study was measured by ATB Fungus 3 method, and the potential relationship was examined by obtaining the correlation of measured minimal inhibitory concentrations (MICs) of Candida spp. isolates. A total of 2099 clinical isolates of Candida spp. from 1441 patients were analyzed. The organisms included 1435 isolates of Candida albicans, 207 isolates of Candida glabrata, 65 isolates of Candida parapsilosis, 31 isolates of Candida krusei, 268 isolates of Candida tropicalis. Voriconazole and itraconazole were more active than fluconazole and against Candida spp. in vitro. The fluconazole, itraconazole and voriconazole MIC 90 (MIC for 90% of the isolates) for all Candida spp. isolates was 4mg/L, 1mg/L and 0.25mg/L, respectively. There was a moderate correlation between the fluconazole MIC s for Candida spp. isolates and this for voriconazole (R 2 =0.475; P<0.01) and itraconazole (R 2 =0.431; P<0.01). Voriconazole MICs for the Candida spp. isolates also correlated with those for itraconazole (R 2 =0.401; P<0.01). These observations suggest that the in vitro susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole exhibits a moderate correlation. Published by Elsevier Masson SAS.

Comparison of two in vitro antifungal sensitivity tests and monitoring during therapy of Sporothrix schenckii sensu stricto in Malaysian cats.

PubMed

Han, Hock Siew; Kano, Rui; Chen, Charles; Noli, Chiara

2017-02-01

Feline sporotrichosis is common in Malaysia. Thermosensitivity and effects of azole treatment on fungal susceptibility are unknown. To evaluate thermotolerance and antifungal susceptibility of feline Malaysian Sporothrix isolates, compare microdilution (MD) and E-test results, and investigate changes in susceptibility during azole therapy. Sporothrix schenckii sensu stricto was isolated from 44 cats. Thermotolerance was determined via culture at 37°C for 7 days. Susceptibility to itraconazole (ITZ), ketoconazole (KTZ) and terbinafine (TRB) was assessed in 40 isolates by MD; to amphotericin B (AMB), KTZ, ITZ, fluconazole (FLC) and posaconazole (POS) by E-test. Results were statistically compared by Pearson's Product Moment. In eight ketoconazole treated cats, susceptibility testing to itraconazole and ketoconazole was repeated every two months for six months. Thermotolerance was observed in 36 of 44 (82%) isolates. Assuming that isolates growing at antifungal concentrations ≥4 mg/mL were resistant, all were resistant on E-test to FLC and AMB, 11 (28%) to POS, 6 (15%) to ITZ and 1 (3%) to KTZ. On MD, 27 of 40 (68%) were resistant to TRB, 2 (5%) to ITZ and 3 (8%) to KTZ. There was no correlation between E-test and MD results (KTZ r = 0.10, P = 0.54, and ITZ r = 0.11, P = 0.48). MD values for ITZ and KTZ did not exceed 4 mg/L during KTZ therapy. The majority of feline isolates in Malaysia are thermosensitive. Lack of correlation between E-test and MD suggests that the E-test is unreliable to test antifungal susceptibility for Sporothrix spp. compared to MD. KTZ was the antifungal drug with the lowest MIC. Prolonged KTZ administration may not induce changes in antifungal susceptibility. © 2017 ESVD and ACVD.

In vitro susceptibility of Trichomonas vaginalis to 50 antimicrobial agents.

PubMed Central

Sears, S D; O'Hare, J

1988-01-01

We determined the susceptibilities of five strains of Trichomonas vaginalis, one of which was metronidazole resistant, to 50 antimicrobial agents. For the metronidazole-susceptible strains, the most active agents were metronidazole, tinidazole, mebendazole, furazolidone, and anisomycin. Against the resistant strain mebendazole, furazolidone, and anisomycin were the most active. Antifungal agents, beta-lactams, macrolides, aminoglycosides, and folic acid antagonists were ineffective against all strains. PMID:3258142

Broth Microdilution In Vitro Screening: An Easy and Fast Method to Detect New Antifungal Compounds.

PubMed

de-Souza-Silva, Calliandra Maria; Guilhelmelli, Fernanda; Zamith-Miranda, Daniel; de Oliveira, Marco Antônio; Nosanchuk, Joshua Daniel; Silva-Pereira, Ildinete; Albuquerque, Patrícia

2018-02-14

Fungal infections have become an important medical condition in the last decades, but the number of available antifungal drugs is limited. In this scenario, the search for new antifungal drugs is necessary. The protocol reported here details a method to screen peptides for their antifungal properties. It is based on the broth microdilution susceptibility test from the Clinical and Laboratory Standards Institute (CLSI) M27-A3 guidelines with modifications to suit the research of antimicrobial peptides as potential new antifungals. This protocol describes a functional assay to evaluate the activity of antifungal compounds and may be easily modified to suit any particular class of molecules under investigation. Since the assays are performed in 96-well plates using small volumes, a large-scale screening can be completed in a short amount of time, especially if carried out in an automation setting. This procedure illustrates how a standardized and adjustable clinical protocol can help the bench-work pursuit of new molecules to improve the therapy of fungal diseases.

The Role of In Vitro Susceptibility Testing in the Management of Candida and Aspergillus.

PubMed

Ostrosky-Zeichner, Luis; Andes, David

2017-08-15

Antifungal susceptibility testing has evolved from a research technique to a standardized and well-validated tool for the clinical management of fungal infections and for epidemiological studies. Genetic mutations and phenotypic resistance in vitro have been shown to correlate with clinical outcomes and treatment failures, and this in turn has led to the creation of clinical breakpoints and, more recently, epidemiological cutoff values for clinically relevant fungal pathogens. Resistance mechanisms for Candida and Aspergillus species have been extensively described and their corresponding genetic mutations can now be readily detected. Epidemiological studies have been able to detect the emergence of regional clonal and nonclonal resistance in several countries. The clinical microbiology laboratory is expected to transition from culture and traditional susceptibility testing to molecular methods for detection, identification, and resistance profiling over the next 5-10 years. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Antifungal Activity of Gallic Acid In Vitro and In Vivo.

PubMed

Li, Zhi-Jian; Liu, Meng; Dawuti, Gulina; Dou, Qin; Ma, Yu; Liu, Heng-Ge; Aibai, Silafu

2017-07-01

Gallic acid (GA) is a polyphenol natural compound found in many medicinal plant species, including pomegranate rind (Punica granatum L.), and has been shown to have antiinflammatory and antibacterial properties. Pomegranate rind is used to treat bacterial and fungal pathogens in Uyghur and other systems of traditional medicine, but, surprisingly, the effects of GA on antifungal activity have not yet been reported. In this study, we aimed to investigate the inhibitory effects of GA on fungal strains both in vitro and in vivo. The minimal inhibitory concentration (MIC) was determined by the NCCLS (M38-A and M27-A2) standard method in vitro, and GA was found to have a broad spectrum of antifungal activity, with MICs for all the tested dermatophyte strains between 43.75 and 83.33 μg/mL. Gallic acid was also active against three Candida strains, with MICs between 12.5 and 100.0 μg/mL. The most sensitive Candida species was Candida albicans (MIC = 12.5 μg/mL), and the most sensitive filamentous species was Trichophyton rubrum (MIC = 43.75 μg/mL), which was comparable in potency to the control, fluconazole. The mechanism of action was investigated for inhibition of ergosterol biosynthesis using an HPLC-based assay and an enzyme linked immunosorbent assay. Gallic acid reduced the activity of sterol 14α-demethylase P450 (CYP51) and squalene epoxidase in the T. rubrum membrane, respectively. In vivo model demonstrated that intraperitoneal injection administration of GA (80 mg/kg d) significantly enhanced the cure rate in a mice infection model of systemic fungal infection. Overall, our results confirm the antifungal effects of GA and suggest a mechanism of action, suggesting that GA has the potential to be developed further as a natural antifungal agent for clinical use. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Comparison of the Vitek 2 Antifungal Susceptibility System with the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) Broth Microdilution Reference Methods and with the Sensititre YeastOne and Etest Techniques for In Vitro Detection of Antifungal Resistance in Yeast Isolates ▿ ‖

PubMed Central

Cuenca-Estrella, Manuel; Gomez-Lopez, Alicia; Alastruey-Izquierdo, Ana; Bernal-Martinez, Leticia; Cuesta, Isabel; Buitrago, Maria J.; Rodriguez-Tudela, Juan L.

2010-01-01

The commercial technique Vitek 2 system for antifungal susceptibility testing of yeast species was evaluated. A collection of 154 clinical yeast isolates, including amphotericin B- and azole-resistant organisms, was tested. Results were compared with those obtained by the reference procedures of both the CLSI and the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Two other commercial techniques approved for clinical use, the Etest and the Sensititre YeastOne, were included in the comparative exercise as well. The average essential agreement (EA) between the Vitek 2 system and the reference procedures was >95%, comparable with the average EAs observed between the reference procedures and the Sensititre YeastOne and Etest. The EA values were >97% for Candida spp. and stood at 92% for Cryptococcus neoformans. Intraclass correlation coefficients (ICC) between the commercial techniques and the reference procedures were statistically significant (P < 0.01). Percentages of very major errors were 2.6% between Vitek 2 and the EUCAST technique and 1.6% between Vitek 2 and the CLSI technique. The Vitek 2 MIC results were available after 14 to 18 h of incubation for all Candida spp. (average time to reading, 15.5 h). The Vitek 2 system was shown to be a reliable technique to determine antifungal susceptibility testing of yeast species and a more rapid and easier alternative for clinical laboratories than the procedures developed by either the CLSI or EUCAST. PMID:20220169

Antifungal activity of essential oils from Iranian plants against fluconazole-resistant and fluconazole-susceptible Candida albicans

PubMed Central

Sharifzadeh, Aghil; Shokri, Hojjatollah

2016-01-01

Objective: The purpose of this study was to assay the antifungal activity of selected essential oils obtained from plants against both fluconazole (FLU)-resistant and FLU-susceptible C. albicans strains isolated from HIV positive patients with oropharyngeal candidiasis (OPC). Materials and Methods: The essential oils were obtained by hydrodistillation method from Myrtus communis (My. communis), Zingiber officinale roscoe (Z. officinale roscoe), Matricaria chamomilla (Ma. chamomilla), Trachyspermum ammi (T. ammi) and Origanum vulgare (O. vulgare). The susceptibility test was based on the M27-A2 methodology. The chemical compositions of the essential oils were obtained by gas chromatography- mass spectroscopy (GC-MS). Results: In GC-MS analysis, thymol (63.40%), linalool (42%), α-pinene (27.87%), α-pinene (22.10%), and zingiberene (31.79%) were found to be the major components of T. ammi, O. vulgare, My. communis, Ma. chamomilla and Z. officinale roscoe, respectively. The results showed that essential oils have different levels of antifungal activity. O. vulgare and T. ammi essential oils were found to be the most efficient (P<0.05). The main finding was that the susceptibilities of FLU-resistant C. albicans to essential oils were higher than those of the FLU-susceptible yeasts. Conclusion: Results of this study indicated that the oils from medicinal plants could be used as potential anti FLU-resistant C. albicans agents. PMID:27222835

Commonly used oncology drugs decrease antifungal effectiveness against Candida and Aspergillus species.

PubMed

Butts, Arielle; Reitler, Parker; Ge, Wenbo; Fortwendel, Jarrod R; Palmer, Glen E

2018-04-30

The incidence of invasive fungal infections has risen significantly in recent decades as medical interventions have become increasingly aggressive. These infections are extremely difficult to treat due to the extremely limited repertoire of systemic antifungals, the development of drug resistance, and the extent of to which the patient's immune function is compromised. Even when the appropriate antifungal therapies are administered in a timely fashion, treatment failure is common, frequently even in the absence of in vitro microbial resistance. In this study, we screened a small collection of FDA approved oncolytic agents for compounds that impact the efficacy of the two most widely used classes of system antifungals against Candida albicans, Candida glabrata , and Aspergillus fumigatus We have identified several drugs that enhance fungal growth in the presence of the azole antifungals and examine the potential that these drugs directly affect fungal fitness, specifically antifungal susceptibility, and may be contributing to clinical treatment failure. Copyright © 2018 American Society for Microbiology.

Yeasts from Scarlet ibises (Eudocimus ruber): A focus on monitoring the antifungal susceptibility of Candida famata and closely related species.

PubMed

Brilhante, Raimunda Sâmia Nogueira; Silva, Aline Lobão da; Monteiro, Frederico Ozanan Barros; Guedes, Glaucia Morgana de Melo; Sales, Jamille Alencar; Oliveira, Jonathas Sales de; Maia Junior, José Erisvaldo; Miranda, Stefânia Araújo; Sidrim, José Júlio Costa; Alencar, Lucas Pereira de; Castelo-Branco, Débora Souza Collares Maia; Cordeiro, Rossana de Aguiar; Pereira Neto, Waldemiro de Aquino; Rocha, Marcos Fábio Gadelha

2017-10-01

This study aimed to identify yeasts from the gastrointestinal tract of scarlet ibises (Eudocimus ruber) and from plant material collected from the environment where they live. Then, the isolates phenotypically identified as Candida famata were submitted to molecular identification of their closely related species and evaluated for their antifungal susceptibility and possible resistance mechanisms to antifungal drugs. Cloacal swabs from 20 scarlet ibises kept in captivity at Mangal das Garças Park (Brazil), pooled stool samples (n = 20) and samples of trunks and hollow of trees (n = 20) obtained from their enclosures were collected. The samples were seeded on Sabouraud agar supplemented with chloramphenicol. The 48 recovered isolates were phenotypically identified as 15 Candida famata, 13 Candida catenulata, 2 Candida intermedia, 1 Candida lusitaniae, 2 Candida guilliermondii, 1 Candida kefyr, 1 Candida amapae, 1 Candida krusei, 8 Trichosporon spp., and 4 Rhodotorula spp. The C. famata isolates were further identified as 3 C. famata, 8 Debaryomyces nepalensis, and 4 C. palmioleophila. All C. famata and C. palmioleophila were susceptible to caspofungin and itraconazole, while one D. nepalensis was resistant to fluconazole and voriconazole. This same isolate and another D. nepalensis had lower amphotericin B susceptibility. The azole resistant strain had an increased efflux of rhodamine 6G and an alteration in the membrane sterol content, demonstrating multifactorial resistance mechanism. Finally, this research shows that scarlet ibises and their environment harbor C. famata and closely related species, including antifungal resistant isolates, emphasizing the need of monitoring the antifungal susceptibility of these yeast species. © The Author 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Molecular characterization and antifungal susceptibility of Cryptococcus neoformans strains collected from a single institution in Lima, Peru.

PubMed

Bejar, Vilma; Tello, Mercedes; García, Ruth; Guevara, José M; Gonzales, Sofia; Vergaray, German; Valencia, Esther; Abanto, Enma; Ortega-Loayza, Alex G; Hagen, Ferry; Gutierrez, Ericson L

2015-01-01

Cryptococcosis is a fungal infection with a worldwide distribution, mainly caused by Cryptococcus neoformans and Cryptococcus gattii. To molecularly characterize the mating-types, serotypes, genotypes and antifungal susceptibility profiles of a set of retrospectively isolated C. neoformans strains from Lima, Peru. A set of 32 Cryptococcus spp. strains from the Institute of Tropical Medicine of the National University of San Marcos, Lima, Peru, were included in this retrospective study. Twenty-four strains were isolated from patients, while the remaining 8 were isolated from the environment. Using conventional PCR, 27 (84.4%) of the isolates were identified as C. neoformans var. grubii mating-type alpha and serotype A. Using the AFLP fingerprinting, it was shown that 16 (50%) of the C. neoformans strains were genotype AFLP1, 13 (40.6%) were genotype AFLP1B, 2 (6.3%) were genotype AFLP2, and 1 (3.1%) was found to be a hybrid between both C. neoformans varieties (genotype AFLP3). The antifungal susceptibility profiles for amphotericin B, fluconazole and voriconazole showed that all the 32 C. neoformans are sensitive to these antifungal compounds. In this study we observed that C. neoformans var. grubii (AFLP1 and AFLP1B) and C. neoformans var. neoformans (AFLP2) were the only cryptococcal varieties involved. All strains were found to be sensitive to the antifungals tested, results that are consistent with those found in the international literature. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Anti-fungal activity of Morinda citrifolia (noni) extracts against Candida albicans: an in vitro study.

PubMed

Barani, K; Manipal, Sunayana; Prabu, D; Ahmed, Adil; Adusumilli, Preethi; Jeevika, C

2014-01-01

The aim of this study was to investigate the anti-fungal activity of Morinda citrifolia fruit extract on Candida albicans. Juice extract from M. citrifolia fruit was lyophilized and used in anti-fungal testing. Anti-fungal activity of M. citrifolia fruit extract against C. albicans was tested in vitro at various concentrations. The inhibitory effect of M. citrifolia extract on C. albicans was determined by agar culture and applied broth dilution test. M. citrifolia extract at 1000 μg/ml concentration effectively inhibited the growth of C. albicans (16.6 ± 0.3) compared with the positive control - amphotericin B (20.6 ± 0.6). It was found to be a dose-dependent reaction. M. citrifolia fruit extract had an anti-fungal effect on C. albicans and the inhibitory effect varied with concentration.

Unexpected effects of azole transporter inhibitors on antifungal susceptibility in Candida glabrata and other pathogenic Candida species

PubMed Central

Nagayoshi, Yohsuke; Shimamura, Shintaro; Nakayama, Hironobu; Minematsu, Asuka; Yamauchi, Shunsuke; Takazono, Takahiro; Nakamura, Shigeki; Yanagihara, Katsunori; Kohno, Shigeru; Mukae, Hiroshi; Izumikawa, Koichi

2017-01-01

The pathogenic fungus Candida glabrata is often resistant to azole antifungal agents. Drug efflux through azole transporters, such as Cdr1 and Cdr2, is a key mechanism of azole resistance and these genes are under the control of the transcription factor Pdr1. Recently, the monoamine oxidase A (MAO-A) inhibitor clorgyline was shown to inhibit the azole efflux pumps, leading to increased azole susceptibility in C. glabrata. In the present study, we have evaluated the effects of clorgyline on susceptibility of C. glabrata to not only azoles, but also to micafungin and amphotericin B, using wild-type and several mutant strains. The addition of clorgyline to the culture media increased fluconazole susceptibility of a C. glabrata wild-type strain, whereas micafungin and amphotericin B susceptibilities were markedly decreased. These phenomena were also observed in other medically important Candida species, including Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida krusei. Expression levels of CDR1, CDR2 and PDR1 mRNAs and an amount of Cdr1 protein in the C. glabrata wild-type strain were highly increased in response to the treatment with clorgyline. However, loss of Cdr1, Cdr2, Pdr1, and a putative clorgyline target (Fms1), which is an ortholog of human MAO-A, or overexpression of CDR1 did not affect the decreased susceptibility to micafungin and amphotericin B in the presence of clorgyline. The presence of other azole efflux pump inhibitors including milbemycin A4 oxime and carbonyl cyanide 3-chlorophenylhydrazone also decreased micafungin susceptibility in C. glabrata wild-type, Δcdr1, Δcdr2, and Δpdr1 strains. These findings suggest that azole efflux pump inhibitors increase azole susceptibility but concurrently induce decreased susceptibility to other classes of antifungals independent of azole transporter functions. PMID:28700656

Unexpected effects of azole transporter inhibitors on antifungal susceptibility in Candida glabrata and other pathogenic Candida species.

PubMed

Nagayoshi, Yohsuke; Miyazaki, Taiga; Shimamura, Shintaro; Nakayama, Hironobu; Minematsu, Asuka; Yamauchi, Shunsuke; Takazono, Takahiro; Nakamura, Shigeki; Yanagihara, Katsunori; Kohno, Shigeru; Mukae, Hiroshi; Izumikawa, Koichi

2017-01-01

The pathogenic fungus Candida glabrata is often resistant to azole antifungal agents. Drug efflux through azole transporters, such as Cdr1 and Cdr2, is a key mechanism of azole resistance and these genes are under the control of the transcription factor Pdr1. Recently, the monoamine oxidase A (MAO-A) inhibitor clorgyline was shown to inhibit the azole efflux pumps, leading to increased azole susceptibility in C. glabrata. In the present study, we have evaluated the effects of clorgyline on susceptibility of C. glabrata to not only azoles, but also to micafungin and amphotericin B, using wild-type and several mutant strains. The addition of clorgyline to the culture media increased fluconazole susceptibility of a C. glabrata wild-type strain, whereas micafungin and amphotericin B susceptibilities were markedly decreased. These phenomena were also observed in other medically important Candida species, including Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida krusei. Expression levels of CDR1, CDR2 and PDR1 mRNAs and an amount of Cdr1 protein in the C. glabrata wild-type strain were highly increased in response to the treatment with clorgyline. However, loss of Cdr1, Cdr2, Pdr1, and a putative clorgyline target (Fms1), which is an ortholog of human MAO-A, or overexpression of CDR1 did not affect the decreased susceptibility to micafungin and amphotericin B in the presence of clorgyline. The presence of other azole efflux pump inhibitors including milbemycin A4 oxime and carbonyl cyanide 3-chlorophenylhydrazone also decreased micafungin susceptibility in C. glabrata wild-type, Δcdr1, Δcdr2, and Δpdr1 strains. These findings suggest that azole efflux pump inhibitors increase azole susceptibility but concurrently induce decreased susceptibility to other classes of antifungals independent of azole transporter functions.

Candida profiles and antifungal resistance evolution over a decade in Lebanon.

PubMed

Araj, George Farah; Asmar, Rima George; Avedissian, Aline Zakaria

2015-09-27

Infection with and antifungal resistance of Candida species have been on the rise globally. Relevant data on these pathogens are relatively few in our region, including Lebanon, thus warranting this study. This retrospective study of Candida spp. profiles and their in vitro antifungal susceptibility was based on analysis requests for 186 Candida non-albicans and 61 C. albicans during three periods (2005-2007, 2009-2011, and 2012-2014) over the span of the last 10 years at the American University of Beirut Medical Center (AUBMC), a major tertiary care center in Lebanon. Identification of Candida was done using the API 20C AUX system, and the E-test was used to determine the minimum inhibitory concentrations (MICs) of antifungal agents. Among the 1,300-1,500 Candida isolates recovered yearly, C. albicans rates decreased from 86% in 2005 to around 60% in 2014. Simultaneously, the non-albicans rates increased from 14% in 2005 to around 40% in 2014, revealing 11 species, the most frequent of which were C. tropicalis, C. glabrata, and C. parapsilosis. All these demonstrated high resistance (35%-79%) against itraconazole, but remained uniformly susceptible (100%) to amphotericin B. Though C. albicans and the other species maintained high susceptibility against fluconazole and voriconazole, their MIC90 showed an elevated trend over time, and C. glabrata had the highest resistance rates. The observed rise in resistance among Candida spp. in Lebanon mandates the need for close surveillance and monitoring of antifungal drug resistance for both epidemiologic and treatment purposes.

Searching new antifungals: The use of in vitro and in vivo methods for evaluation of natural compounds.

PubMed

Scorzoni, Liliana; Sangalli-Leite, Fernanda; de Lacorte Singulani, Junya; de Paula E Silva, Ana Carolina Alves; Costa-Orlandi, Caroline Barcelos; Fusco-Almeida, Ana Marisa; Mendes-Giannini, Maria José Soares

2016-04-01

In the last decades, the increased number of immunocompromised patients has led to the emergence of many forms of fungal infections. Furthermore, there are a restricted arsenal of antifungals available and an increase in the development of resistance to antifungal drugs. Because of these disadvantages, the search for new antifungal agents in natural sources has increased. The development of these new antifungal drugs involves various steps and methodologies. The evaluation of the in vitro antifungal activity and cytotoxicity are the first steps in the screening. There is also the possibility of antifungal combinations to improve the therapy and reduce toxicity. Despite that, the application of the new antifungal candidate could be used in association with photodynamic therapy or using nanotechnology as an ally. In vivo tests can be performed to evaluate the efficacy and toxicity using conventional and alternative animal models. In this work, we review the methods available for the evaluation of the antifungal activity and safety of natural products, as well as the recent advances of new technology in the application of natural products for antifungal therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

Deletion of the Candida glabrata ERG3 and ERG11 genes: effect on cell viability, cell growth, sterol composition, and antifungal susceptibility.

PubMed Central

Geber, A; Hitchcock, C A; Swartz, J E; Pullen, F S; Marsden, K E; Kwon-Chung, K J; Bennett, J E

1995-01-01

We have cloned and sequenced the structural genes encoding the delta 5,6 sterol desaturase (ERG3 gene) and the 14 alpha-methyl sterol demethylase (ERG11 gene) from Candida glabrata L5 (leu2). Single and double mutants of these genes were created by gene deletion. The phenotypes of these mutants, including sterol profiles, aerobic viabilities, antifungal susceptibilities, and generation times, were studied. Strain L5D (erg3 delta::LEU2) accumulated mainly ergosta-7,22-dien-3 beta-ol, was aerobically viable, and remained susceptible to antifungal agents but had a slower generation time than its parent strain. L5LUD (LEU2 erg11 delta::URA3) strains required medium supplemented with ergosterol and an anaerobic environment for growth. A spontaneous aerobically viable mutant, L5LUD40R (LEU erg11 delta::URA3), obtained from L5LUD (LEU2 erg11 delta::URA3), was found to accumulate lanosterol and obtusifoliol, was resistant to azole antifungal agents, demonstrated some increase in resistance to amphotericin B, and exhibited a 1.86-fold increase in generation time in comparison with L5 (leu2). The double-deletion mutant L5DUD61 (erg3 delta::LEU2 erg11 delta::URA3) was aerobically viable, produced mainly 14 alpha-methyl fecosterol, and had the same antifungal susceptibility pattern as L5LUD40R (LEU2 erg11 delta::URA3), and its generation time was threefold greater than that of L5 (leu2). Northern (RNA) analysis revealed that the single-deletion mutants had a marked increase in message for the undeleted ERG3 and ERG11 genes. These results indicate that differences in antifungal susceptibilities and the restoration of aerobic viability exist between the C. glabrata ergosterol mutants created in this study and those sterol mutants with similar genetic lesions previously reported for Saccharomyces cerevisiae. PMID:8593007

Study of strains of Candida spp. Isolated from catheters in UHC of Oran (Algeria): Identification and antifungal susceptibility.

PubMed

Bendjelloul, M; Boucherit-Otmani, Z; Boucherit, K

2016-09-01

The increasing incidence of Candida spp., and the vital prognosis often compromise for patients with Candida species make urgent the exact knowledge of their distribution worldwide and exhaust action antifungals currently used in clinical. That why we carry out an epidemiological study of Candida species and testing their susceptibility against two antifungals: amphotericin B and caspofungin. Samplings of peripheral venous catheters (PVC) were carried out from during 8months on the services of Internal medicine, Surgery A and Neonatology of Oran's University Hospital Center (UHC). The study of the susceptibility of Candida species to antifungal agents was performed according to the Clinical Laboratory Standards Institute (CLSI 2008). From 300 samples, 25 yeasts were isolated. The rate of colonization PVC was 8.33% by Candida spp. The most isolated strains were Candida parapsilosis with 64% of cases, followed by Candida albicans (12%) then 8% for Candida glabrata and Candida krusei. However, only 4% of isolates were Candida famata or Candida lusitaniae. Furthermore all isolated strains were susceptible to amphotericin B with Minimum Inhibitory Concentrations (MIC) ranging from 0.25 to 1μg/mL. MIC obtained with caspofungin vary from 0.0625 to 2μg/mL for all strains. Moreover, one strain of C. krusei is resistant to caspofungin with a MIC superior to 8μg/mL. All though caspofungin is at least as effective as amphotericin B, it is better tolerated for the treatment of invasive fungal infections. Copyright © 2016. Published by Elsevier Masson SAS.

Diversity and Antifungal Drug Susceptibility of Cryptococcus Isolates in Thailand.

PubMed

Worasilchai, Navaporn; Tangwattanachuleeporn, Marut; Meesilpavikkai, Kornvalee; Folba, Claudia; Kangogo, Mourine; Groß, Uwe; Weig, Michael; Bader, Oliver; Chindamporn, Ariya

2017-08-01

Yeasts of the Cryptococcus species complex are the causative agent of cryptococcosis, especially in human immunodeficiency virus (HIV) positive individuals. Cerebral or disseminated cryptococcosis has a very high mortality rate worldwide, including in Thailand. Additionally, an increasing rate of antifungal drug resistant cryptococcal isolates has been reported in several neighboring countries, complicating therapeutic approaches. To understand the situation of this infection in Thailand, we retrospectively investigated the molecular epidemiology and antifungal drug resistance in a collection of 74 clinical, 52 environmental and two veterinary isolates using the URA5-RFLP for typing and the EUCAST guideline for susceptibility testing. Where no EUCAST breakpoints (AMB and 5FC) were available, CLSI epidemiologic cutoff values were used for interpretation. Cryptococcal molecular type diversity showed most isolates were C. grubii, molecular type VNI. One clinical isolate was C. deuterogattii (mol. type VGII) and another C. grubii (mol. type VNII). One strain from environment was classified as C. grubii (mol. type VNII). No resistant strains were detected in this retrospective study for either of the antimycotics tested; however, monitoring of the epidemiology of Cryptococcus species in infected patients in Thailand needs to be continued to detect emergence of resistance. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Antifungal Drug Susceptibility of Candida Species Isolated from HIV-Positive Patients Recruited at a Public Hospital in São Luís, Maranhão, Brazil.

PubMed

Terças, Ana L G; Marques, Sirlei G; Moffa, Eduardo B; Alves, Márcia B; de Azevedo, Conceição M P S; Siqueira, Walter L; Monteiro, Cristina A

2017-01-01

Oropharyngeal candidiasis is the most common fungal infection in hospitalized patients with acquired immune deficiency syndrome (AIDS). Its progression results in invasive infections, which are a significant cause of morbidity and mortality. This study aimed to quickly and accurately identify Candida spp. from oral mucosa of AIDS patients recruited at Presidente Vargas Hospital, in São Luís city, Brazil and to evaluate the sensitivity profile of these fungi to antifungals by using an automated system. Isolates were collected from oropharyngeal mucosa of 52 hospitalized AIDS patients, under anti-viral and antifungal therapies. Patients were included in research if they were HIV-positive, above 18 years of age and after obtaining their written consent. CHROMagar ® Candida and the automated ViteK-2 ® system were used to isolate and identify Candida spp., respectively. Antifungal susceptibility testing was performed using the ViteK-2 ® system, complemented with the Etest ® , using the drugs amphotericin B, fluconazole, flucytosine, and voriconazole. Oropharyngeal candidiasis had a high prevalence in these hospitalized AIDS patients (83%), and the most prevalent species was Candida albicans (56%). Antifungal susceptibility test showed that 64.7% of the Candida spp. were susceptible, 11.8% were dose-dependent sensitive, and 23.5% were resistant. All the Candida krusei and Candida famata isolates and two of Candida glabrata were resistant to fluconazole. Most of AIDS patients presented oropharyngeal candidiasis and C. albicans was the most frequently isolated species. The results showed high variability in resistance among isolated species and indicates the need to identify the Candida spp. involved in the infection and the need to test antifungal susceptibility as a guide in drug therapy in patients hospitalized with AIDS. This is the first relate about AIDS patients monitoring in a public hospital in São Luís concerning the precise identification and

Saccharomyces cerevisiae biofilm tolerance towards systemic antifungals depends on growth phase.

PubMed

Bojsen, Rasmus; Regenberg, Birgitte; Folkesson, Anders

2014-12-04

Biofilm-forming Candida species cause infections that can be difficult to eradicate, possibly because of antifungal drug tolerance mechanisms specific to biofilms. In spite of decades of research, the connection between biofilm and drug tolerance is not fully understood. We used Saccharomyces cerevisiae as a model for drug susceptibility of yeast biofilms. Confocal laser scanning microscopy showed that S. cerevisiae and C. glabrata form similarly structured biofilms and that the viable cell numbers were significantly reduced by treatment of mature biofilms with amphotericin B but not voriconazole, flucytosine, or caspofungin. We showed that metabolic activity in yeast biofilm cells decreased with time, as visualized by FUN-1 staining, and mature, 48-hour biofilms contained cells with slow metabolism and limited growth. Time-kill studies showed that in exponentially growing planktonic cells, voriconazole had limited antifungal activity, flucytosine was fungistatic, caspofungin and amphotericin B were fungicidal. In growth-arrested cells, only amphotericin B had antifungal activity. Confocal microscopy and colony count viability assays revealed that the response of growing biofilms to antifungal drugs was similar to the response of exponentially growing planktonic cells. The response in mature biofilm was similar to that of non-growing planktonic cells. These results confirmed the importance of growth phase on drug efficacy. We showed that in vitro susceptibility to antifungal drugs was independent of biofilm or planktonic growth mode. Instead, drug tolerance was a consequence of growth arrest achievable by both planktonic and biofilm populations. Our results suggest that efficient strategies for treatment of yeast biofilm might be developed by targeting of non-dividing cells.

EUCAST breakpoints for antifungals.

PubMed

Rodríguez-Tudela, Juan L; Arendrup, Maiken C; Cuenca-Estrella, Manuel; Donnelly, J Peter; Lass-Flörl, Cornelia

2010-03-01

Susceptibility testing of fungi and development of interpretative breakpoints has become increasingly important due to the growing incidence of invasive fungal infections, the number and classes of antifungals, and the emerging reports of acquired resistance. The subcommittee on antifungal susceptibility testing of the European Committee on Antibiotic Susceptibility Testing (EUCAST) has developed standards for susceptibility testing of fermentative yeasts and molds as well as proposing breakpoints for fluconazole and voriconazole against Candida. The aim of this work is to describe the EUCAST process of setting breakpoints for antifungals. Five aspects are evaluated during the process of developing breakpoints: 1) the most common dosage used in each European country, 2) the definition of the wild-type population for each target microorganism at the species level and the determination of epidemiological cutoffs, 3) the drug's pharmacokinetics and 4) pharmacodynamics, including Monte Carlo simulations, and 5) the correlation of MICs with clinical outcome of patients treated with the compound. When insufficient data are available (e.g., due to lack of information on the clinical outcome of infections caused by isolates with an elevated MIC), epidemiological cutoff values, rather than breakpoints, are recommended until the necessary information becomes available. Copyright 2010 Prous Science, S.A.U. or its licensors. All rights reserved.

Antifungal activity of geldanamycin alone or in combination with fluconazole against Candida species.

PubMed

Zhang, Jinqing; Liu, Wei; Tan, Jingwen; Sun, Yi; Wan, Zhe; Li, Ruoyu

2013-04-01

A standardized broth microdilution method was used to test the antifungal activity of geldanamycin (GA), an inhibitor of heat shock protein 90 (Hsp90), alone or in combination with the antifungal agent fluconazole (FLC) against 32 clinical isolates of Candida spp. In addition, a disk diffusion test was also used to evaluate the antifungal effect of these two drugs against Candida spp. by measuring the inhibition zone diameters. We found that the range of minimal inhibitory concentrations (MICs) for GA alone against Candida spp. was 3.2-12.8 mg/L and the geometric mean of MICs was 6.54 mg/L. In addition, the combination of GA with FLC showed synergistic effects in vitro against 2 FLC-susceptible and 6 FLC-resistant isolates of C. albicans. As for the other isolates, indifference but no antagonism was observed. In the disk diffusion assay, the diameter of inhibition zones for FLC combined with GA against FLC-resistant C. albicans isolates was 30 mm, while no inhibition was observed with FLC alone. These results demonstrate that GA possesses antifungal activity against Candida spp., and the combination of GA with FLC shows in vitro synergistic activity against some C. albicans isolates, especially those resistant to FLC.

In vitro and in vivo antifungal activities of selected Cameroonian dietary spices.

PubMed

Dzoyem, Jean Paul; Tchuenguem, Roland T; Kuiate, Jules R; Teke, Gerald N; Kechia, Frederick A; Kuete, Victor

2014-02-17

Spices and herbs have been used in food since ancient times to give taste and flavor and also as food preservatives and disease remedies. In Cameroon, the use of spices and other aromatic plants as food flavoring is an integral part of dietary behavior, but relatively little is known about their antifungal potential.The present work was designed to assess the antifungal properties of extracts from spices used in Cameroonian dietary. The in vitro antifungal activities of twenty three extracts from twenty one spices were assessed by the broth micro-dilution method against eight fungi. Also, the in vivo activity of Olax subscorpioidea extract (the most active extract) was evaluated in rat model of disseminated candidiasis due to Candida albicans by estimating the fungal burden in blood and kidney. Seven extracts (30%) exhibited moderate to significant antifungal activities, inhibiting the growth of the microorganisms at concentrations ranging from 0.048 to 0.39 mg/mL. Olax subscorpioidea extract exhibited the highest antifungal activity particularly against Candida albicans and Candida tropicalis (MIC of 0.097 mg/mL and 0.048 mg/mL respectively). Sixteen extracts (70%) were weakly active (MICs > 6.25 mg/mL). Oral administration of O. subscorpioidea extract at the dose 2 g/kg of body weight (bw) to artificially infected rats revealed a drop in the number of colony forming units per milliliter (cfu/mL) of Candida albicans cells in the blood below the detection limit (100 cfu/mL) while a modest decrease was observed in the kidney. The present work shows that some of the spices studied possess interesting antifungal properties and could be used to treat candidiasis. Among the plant species tested, Olax subscorpioidea displayed the most promising result.

In Vitro and In Vivo antifungal activities of selected Cameroonian dietary spices

PubMed Central

2014-01-01

Background Spices and herbs have been used in food since ancient times to give taste and flavor and also as food preservatives and disease remedies. In Cameroon, the use of spices and other aromatic plants as food flavoring is an integral part of dietary behavior, but relatively little is known about their antifungal potential. The present work was designed to assess the antifungal properties of extracts from spices used in Cameroonian dietary. Methods The in vitro antifungal activities of twenty three extracts from twenty one spices were assessed by the broth micro-dilution method against eight fungi. Also, the in vivo activity of Olax subscorpioidea extract (the most active extract) was evaluated in rat model of disseminated candidiasis due to Candida albicans by estimating the fungal burden in blood and kidney. Results Seven extracts (30%) exhibited moderate to significant antifungal activities, inhibiting the growth of the microorganisms at concentrations ranging from 0.048 to 0.39 mg/mL. Olax subscorpioidea extract exhibited the highest antifungal activity particularly against Candida albicans and Candida tropicalis (MIC of 0.097 mg/mL and 0.048 mg/mL respectively). Sixteen extracts (70%) were weakly active (MICs > 6.25 mg/mL). Oral administration of O. subscorpioidea extract at the dose 2 g/kg of body weight (bw) to artificially infected rats revealed a drop in the number of colony forming units per milliliter (cfu/mL) of Candida albicans cells in the blood below the detection limit (100 cfu/mL) while a modest decrease was observed in the kidney. Conclusion The present work shows that some of the spices studied possess interesting antifungal properties and could be used to treat candidiasis. Among the plant species tested, Olax subscorpioidea displayed the most promising result. PMID:24533718

The Celecoxib Derivative AR-12 Has Broad-Spectrum Antifungal Activity In Vitro and Improves the Activity of Fluconazole in a Murine Model of Cryptococcosis

PubMed Central

Koselny, Kristy; Green, Julianne; DiDone, Louis; Halterman, Justin P.; Fothergill, Annette W.; Wiederhold, Nathan P.; Patterson, Thomas F.; Cushion, Melanie T.; Rappelye, Chad; Wellington, Melanie

2016-01-01

Only one new class of antifungal drugs has been introduced into clinical practice in the last 30 years, and thus the identification of small molecules with novel mechanisms of action is an important goal of current anti-infective research. Here, we describe the characterization of the spectrum of in vitro activity and in vivo activity of AR-12, a celecoxib derivative which has been tested in a phase I clinical trial as an anticancer agent. AR-12 inhibits fungal acetyl coenzyme A (acetyl-CoA) synthetase in vitro and is fungicidal at concentrations similar to those achieved in human plasma. AR-12 has a broad spectrum of activity, including activity against yeasts (e.g., Candida albicans, non-albicans Candida spp., Cryptococcus neoformans), molds (e.g., Fusarium, Mucor), and dimorphic fungi (Blastomyces, Histoplasma, and Coccidioides) with MICs of 2 to 4 μg/ml. AR-12 is also active against azole- and echinocandin-resistant Candida isolates, and subinhibitory AR-12 concentrations increase the susceptibility of fluconazole- and echinocandin-resistant Candida isolates. Finally, AR-12 also increases the activity of fluconazole in a murine model of cryptococcosis. Taken together, these data indicate that AR-12 represents a promising class of small molecules with broad-spectrum antifungal activity. PMID:27645246

Comparison of two antifungal susceptibility testing of Candida sp. isolates using agar diffusion method: Neo-sensitabs® tablets and Bio-rad® disks.

PubMed

Uwingabiye, J; Iken, M; Zohoun, A G; Boumhil, L; Lemkhente, Z; Naoui, H; Bouchrik, M; Lmimouni, B

2016-03-01

The aim of our study was to evaluate the concordance between the two antifungal susceptibility testing of Candida sp. isolates using agar diffusion method: Neo-Sensitabs(®) tablets and Bio-Rad(®) disks. This is a prospective study conducted in the Laboratory of Parasitology and Mycology of the Mohammed V military teaching hospital from February to August 2012. Upon receiving blood cultures and peripheral sites samples, the identification of Candida isolates performed using routine phenotypic standard tests and the realization of the antifungal susceptibility was carried out on Neo-sensitabs(®) tablets and Bio-Rad(®) disks. A total of 38 Candida strains were isolated: 15 C. albicans (39%), 13 C. glabrata (34%), 5 C. tropicalis (13%), 4 C. krusei (11%) and 1 C. dubliniensis (3%). There were no significant difference (P>0.05) in susceptibility rate between both methods for all antifungal agents tested except for 5-fluorocytosine. The concordance percentage between two methods was 100% for amphotericin B, 97.4% for fluconazole, 94.7% for voriconazole and 73% for 5-fluorocytosine. Both methods are easy to perform, rapid and cost effective. Our results showed the best agreement between the two methods for testing the susceptibility of Candida isolates to amphotericin B, fluconazole and voriconazole while for the 5-fluorocytosine, the concordance rate was low. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Effects of antifungal agents alone and in combination against Candida glabrata strains susceptible or resistant to fluconazole.

PubMed

Alves, Izabel Almeida; Bandeira, Laíssa Arévalo; Mario, Débora Alves Nunes; Denardi, Laura Bedin; Neves, Louise Vignoles; Santurio, Janio Morais; Alves, Sydney Hartz

2012-09-01

The rise of Candida spp. resistant to classic triazole antifungal agents has led to a search for new therapeutic options. Here, we evaluated combinations of antifungals in a checkerboard assay against two groups of Candida glabrata strains: one containing fluconazole-susceptible clinical isolates (FS) and another containing fluconazole-resistant laboratory derivative (FR). The most synergistic combination observed was amphotericin B + flucytosine (synergistic for 61.77 % of FS strains and 76.47 % of FR strains). The most antagonistic combination observed was ketoconazole + flucytosine (FS 61.77 % and FR 55.88 %). Surprisingly, most combinations evidenced indifferent interactions, and the best synergism appeared when amphotericin B and flucytosine were combined against both groups of isolates.

Central nervous system infection due to Cryptococcus gattii sensu lato in India: Analysis of clinical features, molecular profile and antifungal susceptibility.

PubMed

Lahiri Mukhopadhyay, Shayanki; Bahubali, Veenakumari H; Manjunath, Netravathi; Swaminathan, Aarthi; Maji, Sayani; Palaniappan, Marimuthu; Parthasarathy, Satishchandra; Chandrashekar, Nagarathna

2017-11-01

Cryptococcus gattii species complex has evolved as a pathogen in the last two decades causing infection among both immunocompetent and immunocompromised hosts. We aimed to analyse the clinical features of CNS infection caused by C. gattii sensu lato, molecular and antifungal susceptibility profile of this pathogen. Cases diagnosed to have CNS cryptococcosis were included in the study. Cryptococcus recovered from patient's specimen was identified by standard protocol. Species confirmation, mating type and molecular type determination were performed by PCR based methods. Antifungal susceptibility was tested in VITEK2C to amphotericin B, 5-flucytosine, fluconazole and voriconazole. Among 199 cases, 20 (10%) were due to C. gattii, comprising of 75% cryptococcal meningitis and 25% cryptococcoma cases. Young adult males were commonly affected. Headache and vomiting were prominent symptoms and 50% were immunocompromised. Among the isolates, 75%, 20% and 5% were C. tetragattii, C. gattii sensu stricto and C. bacillisporus respectively and all had mating type α. Four (20%) isolates of C. tetragattii and the only isolate of C. bacillisporus were resistant to fluconazole. The most common species isolated from south India is C. tetragattii. The study contributes to the epidemiology of C. gattii and reiterates the need for genotyping and antifungal susceptibility testing. © 2017 Blackwell Verlag GmbH.

Genetic diversity and antifungal susceptibility profiles in causative agents of sporotrichosis

PubMed Central

2014-01-01

Background Sporotrichosis is a chronic subcutaneous mycosis of humans and animals, which is typically acquired by traumatic inoculation of plant material contaminated with Sporothrix propagules, or via animals, mainly felines. Sporothrix infections notably occur in outbreaks, with large epidemics currently taking place in southeastern Brazil and northeastern China. Pathogenic species include Sporothrix brasiliensis, Sporothrix schenckii s. str., Sporothrix globosa, and Sporothrix luriei, which exhibit differing geographical distribution, virulence, and resistance to antifungals. The phylogenetically remote species Sporothrix mexicana also shows a mild pathogenic potential. Methods We assessed a genetically diverse panel of 68 strains. Susceptibility profiles of medically important Sporothrix species were evaluated by measuring the MICs and MFCs for amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), voriconazole (VRC), posaconazole (PCZ), flucytosine (5FC), and caspofungin (CAS). Haplotype networks were constructed to reveal interspecific divergences within clinical Sporothrix species to evaluate genetically deviant isolates. Results ITC and PCZ were moderately effective against S. brasiliensis (MIC90 = 2 and 2 μg/mL, respectively) and S. schenckii (MIC90 = 4 and 2 μg/mL, respectively). PCZ also showed low MICs against the rare species S. mexicana. 5FC, CAS, and FLC showed no antifungal activity against any Sporothrix species. The minimum fungicidal concentration ranged from 2 to >16 μg/mL for AMB against S. brasiliensis and S. schenckii, while the MFC90 was >16 μg/mL for ITC, VRC, and PCZ. Conclusion Sporothrix species in general showed high degrees of resistance against antifungals. Evaluating a genetically diverse panel of strains revealed evidence of multidrug resistant phenotypes, underlining the need for molecular identification of etiologic agents to predict therapeutic outcome. PMID:24755107

Evaluation of antifungal combination against Cryptococcus spp.

PubMed

Reichert-Lima, Franqueline; Busso-Lopes, Ariane F; Lyra, Luzia; Peron, Isabela Haddad; Taguchi, Hideaki; Mikami, Yuzuru; Kamei, Katsuiko; Moretti, Maria Luiza; Schreiber, Angelica Z

2016-09-01

The second cause of death among systemic mycoses, cryptococcosis treatment represents a challenge since that 5-flucytosine is not currently available in Brazil. Looking for alternatives, this study evaluated antifungal agents, alone and combined, correlating susceptibility to genotypes. Eighty Cryptococcus clinical isolates were genotyped by URA5 gene restriction fragment length polymorphism. Antifungal susceptibility was assessed following CLSI-M27A3 for amphotericin (AMB), 5-flucytosine (5FC), fluconazole (FCZ), voriconazole (VRZ), itraconazole (ITZ) and terbinafine (TRB). Drug interaction chequerboard assay evaluated: AMB + 5FC, AMB + FCZ, AMB + TRB and FCZ + TRB. Molecular typing divided isolates into 14 C. deuterogattii (VGII) and C. neoformans isolates were found to belong to genotype VNI (n = 62) and VNII (n = 4). C. neoformans VNII was significantly less susceptible than VNI (P = 0.0407) to AMB; C. deuterogattii was significantly less susceptible than VNI and VNII to VRZ (P < 0.0001). C. deuterogattii was less susceptible than C. neoformans VNI for FCZ (P = 0.0170), ITZ (P < 0.0001) and TRB (P = 0.0090). The combination FCZ + TRB showed 95.16% of synergistic effect against C. neoformans genotype VNI isolates and all combinations showed 100% of synergism against genotype VNII isolates, suggesting the relevance of cryptococcal genotyping as it is widely known that the various genotypes (now species) have significant impact in antifungal susceptibilities and clinical outcome. In difficult-to-treat cryptococcosis, terbinafine and different antifungal combinations might be alternatives to 5FC. © 2016 Blackwell Verlag GmbH.

VT-1161 protects mice against oropharyngeal candidiasis caused by fluconazole-susceptible and -resistant Candida albicans

PubMed Central

Break, Timothy J; Desai, Jigar V; Ferre, Elise M N; Henderson, Christina; Zelazny, Adrian M; Siebenlist, Ulrich; Hoekstra, William J; Schotzinger, Robert J; Garvey, Edward P; Lionakis, Michail S

2018-01-01

Abstract Background Candida albicans, the most common human fungal pathogen, causes chronic mucosal infections in patients with inborn errors of IL-17 immunity that rely heavily on chronic, often lifelong, azole antifungal agents for treatment. However, a rise in azole resistance has predicated a need for developing new antifungal drugs. Objectives To test the in vitro and in vivo efficacy of VT-1161 and VT-1129 in the treatment of oropharyngeal candidiasis with azole-susceptible or -resistant C. albicans strains. Methods MICs of VT-1161, VT-1129 and nine licensed antifungal drugs were determined for 31 Candida clinical isolates. The drug concentrations in mouse serum and tongues were measured following oral administration. IL-17-signalling-deficient Act1−/− mice were infected with fluconazole-susceptible or fluconazole-resistant C. albicans strains, and the amount of mucosal fungal burden was determined after fluconazole or VT-1161 treatment. Results Fourteen isolates (45%) were not fluconazole susceptible (MIC ≥4 mg/L). VT-1161 and VT-1129 showed significant in vitro activity against the majority of the 31 mucosal clinical isolates (MIC50 0.03 and 0.06 mg/L, respectively), including Candida glabrata (MIC50, 0.125 and 0.25 mg/L, respectively). After oral doses, VT-1161 and VT-1129 concentrations in mouse serum and tongues were well above their MIC50 values. VT-1161 was highly effective as treatment of both fluconazole-susceptible and -resistant oropharyngeal candidiasis in Act1−/− mice. Conclusions VT-1129 and VT-1161 exhibit significant in vitro activity against Candida strains, including fluconazole-resistant C. albicans and C. glabrata. VT-1161 administration in mice results in significant mucosal drug accumulation and eradicates infection caused by fluconazole-susceptible and -resistant Candida strains. PMID:29040636

Candida vaginitis during contraceptive use: the influence of methods, antifungal susceptibility and virulence patterns.

PubMed

Güzel, A B; Küçükgöz-Güleç, U; Aydin, M; Gümral, R; Kalkanci, A; Ilkit, M

2013-11-01

No consensus exists about whether contraceptives cause an increased risk of vaginitis, including vulvovaginal candidosis (VVC). We investigated 495 women (252 who used contraceptives; 243 who did not) for the presence of VVC. Antifungal susceptibility testing was performed for five antifungal agents and for boric acid, and three virulence factors were also examined. We recovered 129 (26.1%) monofungal populations from vaginal samples of women with acute VVC (AVVC, n = 18), symptomatic recurrent VVC (RVVC, n = 22) and asymptomatic RVVC (n = 28), as well as of other contraceptive users who carried Candida in their vaginas (n = 61). It is important to note that the women who had VVC used the same contraceptive methods (p > 0.05). Candida albicans was the most common species isolated (45%), followed by C. glabrata (40.3%). Most of the vaginal yeast isolates exhibited low minimum inhibitory concentration levels for the five antifungals tested. However, this was not the case for boric acid. In addition, the yeast fungi that was derived from the AVVC and RVVC patients showed higher amounts of haemolytic activity than the yeast fungi found among the controls (p < 0.05). The use of contraception does not predispose women to VVC (p > 0.05). Also, both host- and organism-related factors were required to achieve optimal clinical treatment for VVC.

Environmental isolation, biochemical identification, and antifungal drug susceptibility of Cryptococcus species.

PubMed

Teodoro, Valter Luis Iost; Gullo, Fernanda Patrícia; Sardi, Janaína de Cássia Orlandi; Torres, Edson Maria; Fusco-Almeida, Ana Marisa; Mendes-Giannini, Maria José Soares

2013-01-01

The incidence of opportunistic fungal infections has increased in recent years and is considered an important public health problem. Among systemic and opportunistic mycoses, cryptococcosis is distinguished by its clinical importance due to the increased risk of infection in individuals infected by human immunodeficiency virus. To determine the occurrence of pathogenic Cryptococcus in pigeon excrement in the City of Araraquara, samples were collected from nine environments, including state and municipal schools, abandoned buildings, parks, and a hospital. The isolates were identified using classical tests, and susceptibility testing for the antifungal drugs (fluconazole, itraconazole, voriconazole, and amphotericin B) independently was also performed. After collection, the excrement samples were plated on Niger agar and incubated at room temperature. A total of 87 bird dropping samples were collected, and 66.6% were positive for the genus Cryptococcus. The following species were identified: Cryptococcus neoformans (17.2%), Cryptococcus gattii (5.2%), Cryptococcus ater (3.5%), Cryptococcus laurentti (1.7%), and Cryptococcus luteolus (1.7%). A total of 70.7% of the isolates were not identified to the species level and are referred to as Cryptococcus spp. throughout the manuscript. Although none of the isolates demonstrated resistance to antifungal drugs, the identification of infested areas, the proper control of birds, and the disinfection of these environments are essential for the epidemiological control of cryptococcosis.

In Vitro Susceptibility of Malassezia pachydermatis Isolates from Canine Skin with Atopic Dermatitis to Ketoconazole and Itraconazole in East Asia

PubMed Central

WATANABE, Shion; KOIKE, Anna; KANO, Rui; NAGATA, Masahiko; CHEN, Charles; HWANG, Cheol-Yong; HASEGAWA, Atsuhiko; KAMATA, Hiroshi

2013-01-01

ABSTRACT Topical or oral azole antifungals are commonly used in canine atopic dermatitis (AD), as the lipophilic yeast Malassezia pachydermatis exacerbates canine AD. To examine whether canine AD lesions harbor azole-resistant M. pachydermatis isolates in East Asia, we investigated the in vitro susceptibility of M. pachydermatis isolates to ketoconazole (KTZ) and itraconazole (ITZ) obtained from AD lesions of canines in Japan, Korea and Taiwan. The minimum inhibitory concentrations (MICs) of KTZ and ITZ were measured by the E-test using Sabouraud dextrose agar with 0.5% Tween 40. The MICs of KTZ and ITZ for isolates from canines with AD were significantly higher than the MICs for isolates from healthy canines. Our findings suggested that the clinical isolates from canine AD skin lesions were less susceptible to azoles than those from normal canine skin in East Asia. PMID:24334863

In vitro susceptibility of Malassezia pachydermatis isolates from canine skin with atopic dermatitis to ketoconazole and itraconazole in East Asia.

PubMed

Watanabe, Shion; Koike, Anna; Kano, Rui; Nagata, Masahiko; Chen, Charles; Hwang, Cheol-Yong; Hasegawa, Atsuhiko; Kamata, Hiroshi

2014-04-01

Topical or oral azole antifungals are commonly used in canine atopic dermatitis (AD), as the lipophilic yeast Malassezia pachydermatis exacerbates canine AD. To examine whether canine AD lesions harbor azole-resistant M. pachydermatis isolates in East Asia, we investigated the in vitro susceptibility of M. pachydermatis isolates to ketoconazole (KTZ) and itraconazole (ITZ) obtained from AD lesions of canines in Japan, Korea and Taiwan. The minimum inhibitory concentrations (MICs) of KTZ and ITZ were measured by the E-test using Sabouraud dextrose agar with 0.5% Tween 40. The MICs of KTZ and ITZ for isolates from canines with AD were significantly higher than the MICs for isolates from healthy canines. Our findings suggested that the clinical isolates from canine AD skin lesions were less susceptible to azoles than those from normal canine skin in East Asia.

Secondary metabolite profiles and antifungal drug susceptibility of Aspergillus fumigatus and closely related species, Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans.

PubMed

Tamiya, Hiroyuki; Ochiai, Eri; Kikuchi, Kazuyo; Yahiro, Maki; Toyotome, Takahito; Watanabe, Akira; Yaguchi, Takashi; Kamei, Katsuhiko

2015-05-01

The incidence of Aspergillus infection has been increasing in the past few years. Also, new Aspergillus fumigatus-related species, namely Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans, were shown to infect humans. These fungi exhibit marked morphological similarities to A. fumigatus, albeit with different clinical courses and antifungal drug susceptibilities. The present study used liquid chromatography/time-of-flight mass spectrometry to identify the secondary metabolites secreted as virulence factors by these Aspergillus species and compared their antifungal susceptibility. The metabolite profiles varied widely among A. fumigatus, A. lentulus, A. udagawae, and A. viridinutans, producing 27, 13, 8, and 11 substances, respectively. Among the mycotoxins, fumifungin, fumiquinazoline A/B and D, fumitremorgin B, gliotoxin, sphingofungins, pseurotins, and verruculogen were only found in A. fumigatus, whereas auranthine was only found in A. lentulus. The amount of gliotoxin, one of the most abundant mycotoxins in A. fumigatus, was negligible in these related species. In addition, they had decreased susceptibility to antifungal agents such as itraconazole and voriconazole, even though metabolites that were shared in the isolates showing higher minimum inhibitory concentrations than epidemiological cutoff values were not detected. These strikingly different secondary metabolite profiles may lead to the development of more discriminative identification protocols for such closely related Aspergillus species as well as improved treatment outcomes. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

In vitro antifungal activity of isavuconazole against 345 mucorales isolates collected at study centers in eight countries.

PubMed

Verweij, P E; González, G M; Wiedrhold, N P; Lass-Flörl, C; Warn, P; Heep, M; Ghannoum, M A; Guinea, J

2009-06-01

Although mucormycoses (formerly zygomycoses) are relatively uncommon, they are associated with high mortality and treatment options are limited. Isavuconazole is a novel, water soluble, broad-spectrum azole in clinical development for the treatment of invasive aspergillosis and candidiasis. The objective of this report was to collate data on the in vitro activity of isavuconazole against a collection of 345 diverse mucorales isolates, collected and tested at eight study centers in europe, mexico and North America. Each study center undertook minimum inhibitory concentration (MIC) susceptibility testing of their isolates, according to EUCAST or CLSI guidelines. Across all study centers, isavuconazole exhibited MIC(50 )values of 1-4 mg/l and MIC(90 )values of 4-16 mg/l against the five genera. There were also marked differences in MIC distributions, which could be ascribed to differences in inoculum and/or endpoint. EUCAST guidelines appeared to generate modal MICs 2-fold higher than CLSI. These results confirm that isavuconazole possesses at least partial antifungal activity against mucorales.

Chemical composition and in vitro antifungal and antioxidant activity of the essential oil and methanolic extract of Teucrium sauvagei Le Houerou.

PubMed

Salah, K Bel Hadj; Mahjoub, M A; Chaumont, J P; Michel, L; Millet-Clerc, J; Chraeif, I; Ammar, S; Mighri, Z; Aouni, M

2006-10-01

The chemical composition and the in vitro antifungal and antioxidant activity of the essential oil and the methanolic leaf extracts of Teucrium sauvagei Le Houerou, an endemic medicinal plant growing in Tunisia, have been studied. More than 35 constituents having an abundance >or=0.2% were identified in the oil. beta-Eudesmol, T-cadinol, alpha-thujene, gamma-cadinene, and sabinene were the prevalent constituents. Results of the antifungal activity tests indicated that the methanolic extract inhibited the in vitro growth of seven dermatophytes, whereas the essential oil showed average inhibition against only three dermatophytes. In vitro antioxidant properties of the essential oil and the methanolic extract were determined by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid)) assays and compared to those of the synthetic antioxidant Trolox. Due to their antifungal and antioxidant properties, the essential oil and the methanolic extract of T. sauvagei may be of use as natural preservative ingredients in food and/or pharmaceutical industries.

Isothermal microcalorimetry for antifungal susceptibility testing of Mucorales, Fusarium spp., and Scedosporium spp.

PubMed

Furustrand Tafin, Ulrika; Meis, Jacques F; Trampuz, Andrej

2012-08-01

We evaluated isothermal microcalorimetry for real-time susceptibility testing of non-Aspergillus molds. MIC and minimal effective concentration (MEC) values of Mucorales (n = 4), Fusarium spp. (n = 4), and Scedosporium spp. (n = 4) were determined by microbroth dilution according to the Clinical Laboratory Standard Institute M38-A2 guidelines. Heat production of molds was measured at 37 °C in Sabouraud dextrose broth inoculated with 2.5 × 10(4) spores/mL in the presence of amphotericin B, voriconazole, posaconazole, caspofungin, and anidulafungin. As determined by microcalorimetry, amphotericin B was the most active agent against Mucorales (MHIC 0.06-0.125 μg/mL) and Fusarium spp. (MHIC 1-4 μg/mL), whereas voriconazole was the most active agent against Scedosporium spp. (MHIC 0.25 to 8 μg/mL). The percentage of agreement (within one 2-fold dilution) between the MHIC and MIC (or MEC) was 67%, 92%, 75%, and 83% for amphotericin B, voriconazole, posaconazole, and caspofungin, respectively. Microcalorimetry provides additional information on timing of antifungal activity, enabling further investigation of drug-mold and drug-drug interaction, and optimization of antifungal treatment. Copyright © 2012 Elsevier Inc. All rights reserved.

Argentinean propolis from Zuccagnia punctata Cav. (Caesalpinieae) exudates: phytochemical characterization and antifungal activity.

PubMed

Agüero, María Belén; Gonzalez, Mariela; Lima, Beatriz; Svetaz, Laura; Sánchez, Marianela; Zacchino, Susana; Feresin, Gabriela Egly; Schmeda-Hirschmann, Guillermo; Palermo, Jorge; Wunderlin, Daniel; Tapia, Alejandro

2010-01-13

This paper reports the in vitro antifungal activity of propolis extracts from the province of Tucuman (Argentina) as well as the identification of their main antifungal compounds and botanical origin. The antifungal activity was determined by the microdilution technique, using reference microorganisms and clinical isolates. All dermatophytes and yeasts tested were strongly inhibited by different propolis extracts (MICs between 16 and 125 microg mL(-1)). The most susceptible species were Microsporum gypseum, Trichophyton mentagrophytes, and Trichophyton rubrum. The main bioactive compounds were 2',4'-dihydroxy-3'-methoxychalcone 2 and 2',4'-dihydroxychalcone 3. Both displayed strong activity against clinical isolates of T. rubrum and T. mentagrophytes (MICs and MFCs between 1.9 and 2.9 microg mL(-1)). Additionally, galangin 5, pinocembrin 6, and 7-hydroxy-8-methoxyflavanone 9 were isolated from propolis samples and Zuccagnia punctata exudates, showing moderate antifungal activity. This is the first study matching the chemical profile of Z. punctata Cav. exudates with their corresponding propolis, giving strong evidence on the botanical origin of the studied propolis.

The patterns of colonization and antifungal susceptibility of Candida, isolated from preterm neonates in Khorramabad, South West of Iran.

PubMed

Kooshki, P; Rezaei-Matehkolaei, A; Mahmoudabadi, A Z

2018-06-01

Usually, 7-20% of preterm neonates colonized by Candida species present invasive candidiasis. Candida albicans, and several non-albicans species cause invasive infection with C. albicans being the most dominant agent. In the last two decades, infection due to non-albicans have been increased dramatically due to their low sensitivity to antifungal drugs such as fluconazole. The aim of present study was to evaluate Candida colonization pattern and antifungal susceptibility among preterm neonates from Khorramabad, South west of Iran. Samples were collected from 80 preterm neonates, cultured on CHROMagar Candida and incubated at 37°C. All recovered isolates were primarily screened based on classical methods and identified by PCR-RFLP targeting the ITS-rDNA regions. Antifungal susceptibility testing of all isolates was performed according to the CLSI method against amphotericin B, caspofungin, itraconazole, fluconazole and voriconazole. Totally 23 isolates of Candida species were recovered from 20 patients (female: male, 50:50) including, C. albicans (18), C. parapsilosis (2) and C. glabrata (1). Furthermore, the blood cultures from two patients were yielded C. albicans and C. parapsilosis so that patient with C. albicans died after five days. Generally, in this study, 9 (39.1%) isolates were resistant to amphotericin B including; 7 (30.4%) C. albicans and 2 (8.7%) C. parapsilosis. In addition, 2 (8.7%) and 4 (17.4%) isolates were also resistant to itraconazole and caspofungin, respectively. In conclusion, Candida colonization among preterm neonates is still an important issue in hospitals. In addition, in spite of a significant amphotericin B resistant Candida, voriconazole, fluconazole, and itraconazole are valuable antifungals, due to fully sensitivity to Candida. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Synthesis and Spectral Characterization of Antifungal Sensitive Schiff Base Transition Metal Complexes

PubMed Central

Sakthivel, A.; Rajasekaran, K.

2007-01-01

New N2O2 donor type Schiff base has been designed and synthesized by condensing acetoacetanilido-4-aminoantipyrine with 2-aminobenzoic acid in ethanol. Solid metal complexes of the Schiff base with Cu(II), Ni(II), Co(II), Mn(II), Zn(II), VO(IV), Hg(II) and Cd(II) metal ions were synthesized and characterized by elemental analyses, magnetic susceptibility, molar conduction, fast atom bombardment (FAB) mass, IR, UV-Vis, and 1H NMR spectral studies. The data show that the complexes have the composition of ML type. The UV-Vis. and magnetic susceptibility data of the complexes suggest a square-planar geometry around the central metal ion except VO(IV) complex which has square-pyramidal geometry. The in vitro antifungal activities of the compounds were tested against fungi such as Aspergillus niger, Aspergillus flavus, Rhizopus stolonifer, Candida albicans, Rhizoctonia bataicola and Trichoderma harizanum. All the metal complexes showed stronger antifungal activities than the free ligand. The minimum inhibitory concentrations (MIC) of the metal complexes were found in the range of 10~31 µg/ml. PMID:24015086

In Vitro Antifungal Activity of Hexahydropyrimidine Derivatives against the Causative Agents of Dermatomycosis

PubMed Central

Caneschi, César A.; Senra, Mônica P.; Carvalho, Gustavo S. G.; da Silva, Adilson D.

2017-01-01

Nitrogenated heterocyclic compounds are present in both natural and synthetic drugs, and hexahydropyrimidine derivatives may prove to be efficient in treating dermatomycosis causing fungi. This study evaluated the antifungal activity of four hexahydropyrimidine derivatives against the dermatomycosis causing fungi. These derivatives were synthesized, characterized, and assessed in terms of their activity against Trichophyton mentagrophytes, Microsporum canis, Microsporum gypseum, Trichophyton rubrum, Fusarium oxysporum, and Epidermophyton floccosum between concentrations 7.8 and 1,000 μg mL−1. Scanning electron micrographs were assessed for the active derivatives and reference drugs, and these micrographs revealed that new agents cause morphological changes in fungi. The derivatives HHP1, HHP3, and HHP4 revealed poor activity against the four fungal strains (MICs range 500–1000 μg mL−1). Compound HHP3 was found to be the best potential antifungal agent among those tested and was the most effective among all the active derivatives that caused morphological changes in the susceptible strains. PMID:29226215

Colonization and antifungals susceptibility patterns of Candida species isolated from hospitalized patients in ICUs and NICUs.

PubMed

Zarei Mahmoudabadi, Ali; Rezaei-Matehkolaei, Ali; Navid, Mojgan; Torabizadeh, Mehdi; Mazdarani, Shahnam

2015-07-01

Several studies have shown that there are an increasing in invasive candidiasis during 2-3 last decades. Although, Candida albicans is considered as the most common candidiasis agents, other non-albicans such as C. glabrata, C. krusei, C. parapsilosis, and C. tropicalis were raised as infectious agents. Resistance to fluconazole among non-albicans species is an important problem for clinicians during therapy and prophylaxis. The aim of current study was to detect the Candida species from hospitalized neonatal and children in intensive care units (ICUs) and neonatal intensive care units (NICUs). In addition, the susceptibility of isolated agents were also evaluated against three antifungals. In the present study 298 samples including 98 blood samples, 100 urines and 100 swabs from oral cavity were inoculated on CHROMagar Candida. Initial detection was done according to the coloration colonies on CHROMagar Candida . Morphology on cornmeal agar, germ tube formation and growth at 45°C were confirmed isolates. Amphotericin B, fluconazole and terbinafine (Lamisil) were used for the susceptibility tests using microdilution method. In the present study 21% and 34% of urines and swabs from oral cavity were positive for Candida species, respectively. The most common species was C. albicans (62.5%) followed by C. tropicalis (15.6%), C. glabrata (6.3%) and Candida species (15.6%). Our study indicated that the most tested species of Candida, 70.3% were sensitive to fluconazole at the concentration of ≤8 μg/mL. Whereas 9 (14.1%) of isolates were resistant to amphotericine B at ≥8 μg/mL. This study demonstrates the importance of species identification and antifungals susceptibility testing for hospitalized patients in ICUs and NICUs wards.

Susceptibility testing of terbinafine alone and in combination with amphotericin B, itraconazole, or voriconazole against conidia and hyphae of dematiaceous molds.

PubMed

Biancalana, Fernanda Simas Corrêa; Lyra, Luzia; Moretti, Maria Luiza; Schreiber, Angélica Zaninelli

2011-12-01

Studies have demonstrated excellent in vivo efficacy of terbinafine combined with other antifungal agents against dematiaceous molds; however, there is a lack of in vitro studies. Most studies evaluated conidia inocula, but susceptibility testing of hyphae could mimic the fungal status in infected tissues and might reflect the therapeutic potential of the agent. We investigated the in vitro susceptibility of terbinafine alone and in combination with amphotericin B, itraconazole, or voriconazole against conidia by microdilution and dynamic measurement of hyphae growth of dematiaceous molds. The MIC values for hyphae were, until 3 dilutions, below the MIC obtained for conidia. The results indicated 100% synergistic interactions between terbinafine and azoles or amphotericin B in all tests, but lower MICs for hyphae. In conclusion, our findings allow us to say that the hyphal form of tested dematiaceous molds showed high susceptibility to all antifungal agents evaluated, alone and in combination with terbinafine. Copyright © 2011 Elsevier Inc. All rights reserved.

Antifungal susceptibility testing of Candida species isolated from the immunocompromised patients admitted to ten university hospitals in Iran: comparison of colonizing and infecting isolates.

PubMed

Badiee, Parisa; Badali, Hamid; Boekhout, Teun; Diba, Kambiz; Moghadam, Abdolkarim Ghadimi; Hossaini Nasab, Ali; Jafarian, Hadis; Mohammadi, Rasoul; Mirhendi, Hossein; Najafzadeh, Mohammad Javad; Shamsizadeh, Ahmad; Soltani, Jafar

2017-11-21

Antifungal susceptibility testing is a subject of interest in the field of medical mycology. The aim of the present study were the distributions and antifungal susceptibility patterns of various Candida species isolated from colonized and infected immunocompromised patients admitted to ten university hospitals in Iran. In totally, 846 Candida species were isolated from more than 4000 clinical samples and identified by the API 20 C AUX system. Antifungal susceptibility testing was performed by broth microdilution method according to CLSI. The most frequent Candida species isolated from all patients was Candida albicans (510/846). The epidemiological cutoff value and percentage of wild-type species for amphotericin B and fluconazole in Candida albicans, Candida tropicalis, Candida glabrata and Candida krusei were 0.5 μg/ml (95%) and 4 μg/ml (96%); 1 μg/ml (95%) and 8 μg/ml (95%); 0.5 μg/ml (99%) and 19 μg/ml (98%); and 4 μg/ml (95%) and 64 μg/ml (95%), respectively. The MIC90 and epidemiological cutoff values to posaconazole in Candida krusei were 0.5 μg/ml. There were significant differences between infecting and colonizing isolates of Candida tropicalis in MIC 90 values of amphotericin B, and isolates of Candida glabrata in values of amphotericin B, caspofungin, and voriconazole (P < 0.05). Our findings suggest that the susceptibility patterns of Candida species (colonizing and infecting isolates) in immunocompromised patients are not the same and acquired resistance was seen in some species.

In vitro antifungal activity of fatty acid methyl esters of the seeds of Annona cornifolia A.St.-Hil. (Annonaceae) against pathogenic fungus Paracoccidioides brasiliensis.

PubMed

Lima, Luciana Alves Rodrigues dos Santos; Johann, Susana; Cisalpino, Patrícia Silva; Pimenta, Lúcia Pinheiro Santos; Boaventura, Maria Amélia Diamantino

2011-01-01

Fatty acids are abundant in vegetable oils. They are known to have antibacterial and antifungal properties. Antifungal susceptibility was evaluated by broth microdilution assay following CLSI (formerly the NCCLS) guidelines against 16 fungal strains of clinical interest. In this work, fatty acid methyl esters (FAME) was able to inhibit 12 clinical strains of the pathogenic fungus Paracoccidioides brasiliensis and were also active in the bioautographic assay against Cladosporium sphaerospermum. FAME was a more potent antifungal than trimethoprim-sulfamethoxazole against P. brasiliensis under the experimental conditions tested.

Correlation between microdilution, Etest, and disk diffusion methods for antifungal susceptibility testing of fluconazole against Candida sp. blood isolates.

PubMed

Menezes, Everardo Albuquerque; Vasconcelos Júnior, Antônio Alexandre de; Ângelo, Maria Rozzelê Ferreira; Cunha, Maria da Conceição dos Santos Oliveira; Cunha, Francisco Afrânio

2013-01-01

Antifungal susceptibility testing assists in finding the appropriate treatment for fungal infections, which are increasingly common. However, such testing is not very widespread. There are several existing methods, and the correlation between such methods was evaluated in this study. The susceptibility to fluconazole of 35 strains of Candida sp. isolated from blood cultures was evaluated by the following methods: microdilution, Etest, and disk diffusion. The correlation between the methods was around 90%. The disk diffusion test exhibited a good correlation and can be used in laboratory routines to detect strains of Candida sp. that are resistant to fluconazole.

Susceptibility Testing of Common and Uncommon Aspergillus Species against Posaconazole and Other Mold-Active Antifungal Azoles Using the Sensititre Method

PubMed Central

Mello, Enrica; Posteraro, Brunella; Vella, Antonietta; De Carolis, Elena; Torelli, Riccardo; D'Inzeo, Tiziana; Verweij, Paul E.

2017-01-01

ABSTRACT We tested 59 common and 27 uncommon Aspergillus species isolates for susceptibility to the mold-active azole antifungal agents itraconazole, voriconazole, and posaconazole using the Sensititre method. The overall essential agreement with the CLSI reference method was 96.5% for itraconazole and posaconazole and was 100% for voriconazole. By the Sensititre method as well as the CLSI reference method, all of 10 A. fumigatus isolates with a cyp51 mutant genotype were classified as being non-wild-type isolates (MIC > epidemiological cutoff value [ECV]) with respect to triazole susceptibility. PMID:28416538

Neglected and emerging fungal infections: review of hyalohyphomycosis by Paecilomyces lilacinus focusing in disease burden, in vitro antifungal susceptibility and management.

PubMed

Antas, Paulo R Z; Brito, Marcelly M S; Peixoto, Érika; Ponte, Carlos G G; Borba, Cíntia M

2012-01-01

Paecilomyces lilacinus is an emerging pathogenic fungus that can cause different clinical manifestations ranging from cutaneous and sub-cutaneous infections to severe oculomycosis. This review discusses infections caused by P. lilacinus, as well as their symptoms and correlates of immune responses, morphological characteristics of the fungus, therapies, in vitro susceptibility tests, laboratory diagnosis and the experimental models available. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Colonization and antifungals susceptibility patterns of Candida species isolated from hospitalized patients in ICUs and NICUs

PubMed Central

Zarei Mahmoudabadi, Ali; Rezaei-Matehkolaei, Ali; Navid, Mojgan; Torabizadeh, Mehdi; Mazdarani, Shahnam

2015-01-01

Background: Several studies have shown that there are an increasing in invasive candidiasis during 2-3 last decades. Although, Candida albicans is considered as the most common candidiasis agents, other non-albicans such as C. glabrata, C. krusei, C. parapsilosis, and C. tropicalis were raised as infectious agents. Resistance to fluconazole among non-albicans species is an important problem for clinicians during therapy and prophylaxis. Objectives: The aim of current study was to detect the Candida species from hospitalized neonatal and children in intensive care units (ICUs) and neonatal intensive care units (NICUs). In addition, the susceptibility of isolated agents were also evaluated against three antifungals. Materials and Methods: In the present study 298 samples including 98 blood samples, 100 urines and 100 swabs from oral cavity were inoculated on CHROMagar Candida. Initial detection was done according to the coloration colonies on CHROMagar Candida . Morphology on cornmeal agar, germ tube formation and growth at 45°C were confirmed isolates. Amphotericin B, fluconazole and terbinafine (Lamisil) were used for the susceptibility tests using microdilution method. Results: In the present study 21% and 34% of urines and swabs from oral cavity were positive for Candida species, respectively. The most common species was C. albicans (62.5%) followed by C. tropicalis (15.6%), C. glabrata (6.3%) and Candida species (15.6%). Our study indicated that the most tested species of Candida, 70.3% were sensitive to fluconazole at the concentration of ≤8 μg/mL. Whereas 9 (14.1%) of isolates were resistant to amphotericine B at ≥8 μg/mL. Conclusions: This study demonstrates the importance of species identification and antifungals susceptibility testing for hospitalized patients in ICUs and NICUs wards. PMID:26312235

Epidemiology and antifungal susceptibility of bloodstream Candida isolates in Quebec: Report on 453 cases between 2003 and 2005

PubMed Central

St-Germain, Guy; Laverdière, Michel; Pelletier, René; René, Pierre; Bourgault, Anne-Marie; Lemieux, Claude; Libman, Michael

2008-01-01

BACKGROUND Between May 2003 and April 2005, a population-based surveillance of Candida bloodstream infections was conducted in Quebec. A total of 453 episodes of candidemia (464 yeast isolates) from 54 participating hospitals were studied. RESULTS The annual incidence rate was three per 100,000 population. Global hospital mortality was 38%. The most common predisposing factors were the presence of an intravascular catheter (80%), use of antibacterial therapy (67%), stay in an intensive care unit (49%), use of parenteral nutrition (32%) and intra-abdominal surgery (31%). Fluconazole alone or in association with other antifungals was used for treatment in over 80% of cases. Candida albicans comprised 62% of isolates, followed by Candida glabrata (17%), Candida parapsilosis (9%), Candida tropicalis (5%), Candida lusitaniae (3%) and Candida krusei (3%). Of the 288 C albicans isolates, seven (2%) were resistant to flucytosine, one to fluconazole and none to itraconazole or voriconazole. Of the 75 non-C albicans species isolates with reduced susceptibility to fluconazole (minimum inhibitory concentration [MIC] 16 μg/mL or greater), none were susceptible to itraconazole (MIC 0.12 mg/L or lower), whereas 71 (95%) were susceptible to voriconazole (MIC 1 μg/mL or lower). However, only five of 12 (42%) fluconazole-resistant isolates were susceptible to voriconazole. Posaconazole, ravuconazole and caspofungin displayed a broad spectrum of activity against these isolates, with MICs of 1 mg/L or lower in 56%, 92% and 100% of isolates, respectively. Overall, a correlation (r2>0.87) was observed among increasing fluconazole MICs and the geometric mean MICs of itraconazole, voriconazole, posaconazole and ravuconazole. CONCLUSIONS These surveillance results when compared with those of the 1993 to 1995 survey confirm little variation in the distribution of species causing invasive Candida infection over a 10-year period in Quebec, as well as the continuous excellent overall in

In vitro activity of the novel antifungal compound F901318 against difficult-to-treat Aspergillus isolates.

PubMed

Buil, J B; Rijs, A J M M; Meis, J F; Birch, M; Law, D; Melchers, W J G; Verweij, P E

2017-09-01

F901318 is a new antifungal agent with a novel mechanism of action with activity against Aspergillus species. We investigated the in vitro activity of F901318 against a collection of Aspergillus isolates. A total of 213 Aspergillus isolates were used in this study. A total of 143 Aspergillus fumigatus sensu stricto isolates were used, of which 133 were azole resistant [25 TR34/L98H; 25 TR46/Y121F/T289A; 33 A. fumigatus with cyp51A-associated point mutations (25 G54, 1 G432 and 7 M220); and 50 azole-resistant A. fumigatus without known resistance mechanisms]. Ten azole-susceptible A. fumigatus isolates were used as WT controls. The in vitro activity was also determined against Aspergillus calidoustus (25 isolates), Aspergillus flavus (10), Aspergillus nidulans (10) and Aspergillus tubingensis (25). F901318 activity was compared with that of itraconazole, voriconazole, posaconazole, isavuconazole, amphotericin B and anidulafungin. Minimum effective concentrations and MICs were determined using the EUCAST broth microdilution method. F901318 was active against all tested isolates: A. fumigatus WT, MIC90 0.125 mg/L (range 0.031-0.125); TR34/L98H,TR46/Y121F/T289A and azole resistant without known resistance mechanisms, MIC90 0.125 mg/L (range 0.031-0.25); A. fumigatus with cyp51A-associated point mutations, MIC90 0.062 mg/L (range 0.015-0.125); and other species, A. calidoustus MIC90 0.5 mg/L (range 0.125-0.5), A. flavus MIC90 0.062 mg/L (range 0.015-0.62), A. nidulans MIC90 0.125 mg/L (range 0.062-0.25) and A. tubingensis MIC90 0.062 mg/L (range 0.015-0.25). F901318 showed potent and consistent in vitro activity against difficult-to-treat Aspergillus spp. with intrinsic and acquired antifungal resistance due to known and unknown resistance mechanisms, suggesting no significant implications of azole resistance mechanisms for the mode of action of F901318. © The Author 2017. Published by Oxford University Press on behalf of the British Society for

Antifungal activity of Cleome gynandra L. aerial parts for topical treatment of Tinea capitis: an in vitro evaluation.

PubMed

Imanirampa, Lawrence; Alele, Paul E

2016-07-08

Cleome gynandra L. (Capparaceae) is an edible weed used in Uganda topically for its presumed antifungal activity against Tinea capitis. The goal of this study was to determine if this plant possesses antifungal activity in vitro, since T. capitis is a pervasive infection among especially rural children. Antifungal activity assay was performed by Broth dilution method, and testing done on clinical isolates of three common Tinea capitis-causing fungal strains. Evaluation of in vitro antifungal activity of the ethanol and water extracts of C. gynandra was done to determine the minimum inhibitory concentrations (MICs) and the minimum fungicidal concentrations (MFCs) of the extracts. The MIC of C. gynandra ethanol extract ranged from 0.0313 to 0.0625 mg/ml for Trichophyton rubrum, and from 0.25 to 0.5 mg/ml for both Microsporum canis and Trichophyton mentagrophytes. The MICs of C. gynandra aqueous extract ranged between 0.125 to 0.25 mg/ml for T. rubrum, and 0.25 to 0.5 mg/ml for both M. canis and T. mentagrophytes. T. rubrum was more sensitive than M. canis (p < 0.002) and more sensitive than T. mentagrophytes (p < 0.035) to the antifungal activity of C. gynandra. T. rubrum was 6.9 times (95 % CL: 1.15 - 41.6) more likely to have a better outcome (more sensitive) than T. mentagrophytes. Cleome gynandra aqueous extract had MFC of ≥0.0313 mg/ml for M. canis, ≥0.0156 mg/ml for T. mentagropyhtes, and ≥0.0625 mg/ml for T. rubrum. Cleome gynandra ethanol extract showed MFCs of ≥0.5 mg/ml for M. canis and T. mentagrophytes, and ≥0.125 mg/ml for T. rubrum. Both plant extracts demonstrated antifungal activity, shown by the MIC and MFC for the different extracts, which varied with the type of organism of the clinical fungal isolates. The ethanol extract exhibited comparable antifungal activity to the aqueous extract indicated by the MIC values seen. Conversely, after subculturing the fungal isolates, MFCs were lower for the aqueous than for the

Antifungal Susceptibilities of Candida Species Causing Vulvovaginitis and Epidemiology of Recurrent Cases

PubMed Central

Richter, Sandra S.; Galask, Rudolph P.; Messer, Shawn A.; Hollis, Richard J.; Diekema, Daniel J.; Pfaller, Michael A.

2005-01-01

There are limited data regarding the antifungal susceptibility of yeast causing vulvovaginal candidiasis, since cultures are rarely performed. Susceptibility testing was performed on vaginal yeast isolates collected from January 1998 to March 2001 from 429 patients with suspected vulvovaginal candidiasis. The charts of 84 patients with multiple positive cultures were reviewed. The 593 yeast isolates were Candida albicans (n = 420), Candida glabrata (n = 112), Candida parapsilosis (n = 30), Candida krusei (n = 12), Saccharomyces cerevisiae ( n = 9), Candida tropicalis (n = 8), Candida lusitaniae (n = 1), and Trichosporon sp. (n = 1). Multiple species suggesting mixed infection were isolated from 27 cultures. Resistance to fluconazole and flucytosine was observed infrequently (3.7% and 3.0%); 16.2% of isolates were resistant to itraconazole (MIC ≥ 1 μg/ml). The four imidazoles (econazole, clotrimazole, miconazole, and ketoconazole) were active: 94.3 to 98.5% were susceptible at ≤1 μg/ml. Among different species, elevated fluconazole MICs (≥16 μg/ml) were only observed in C. glabrata (15.2% resistant [R], 51.8% susceptible-dose dependent [S-DD]), C. parapsilosis (3.3% S-DD), S. cerevisiae (11.1% S-DD), and C. krusei (50% S-DD, 41.7% R, considered intrinsically fluconazole resistant). Resistance to itraconazole was observed among C. glabrata (74.1%), C. krusei (58.3%), S. cerevisiae (55.6%), and C. parapsilosis (3.4%). Among 84 patients with recurrent episodes, non-albicans species were more common (42% versus 20%). A ≥4-fold rise in fluconazole MIC was observed in only one patient with C. parapsilosis. These results support the use of azoles for empirical therapy of uncomplicated candidal vulvovaginitis. Recurrent episodes are more often caused by non-albicans species, for which azole agents are less likely to be effective. PMID:15872235

Susceptibility Testing of Common and Uncommon Aspergillus Species against Posaconazole and Other Mold-Active Antifungal Azoles Using the Sensititre Method.

PubMed

Mello, Enrica; Posteraro, Brunella; Vella, Antonietta; De Carolis, Elena; Torelli, Riccardo; D'Inzeo, Tiziana; Verweij, Paul E; Sanguinetti, Maurizio

2017-06-01

We tested 59 common and 27 uncommon Aspergillus species isolates for susceptibility to the mold-active azole antifungal agents itraconazole, voriconazole, and posaconazole using the Sensititre method. The overall essential agreement with the CLSI reference method was 96.5% for itraconazole and posaconazole and was 100% for voriconazole. By the Sensititre method as well as the CLSI reference method, all of 10 A. fumigatus isolates with a cyp51 mutant genotype were classified as being non-wild-type isolates (MIC > epidemiological cutoff value [ECV]) with respect to triazole susceptibility. Copyright © 2017 American Society for Microbiology.

Antifungal Susceptibility Testing in HIV/AIDS Patients: a Comparison Between Automated Machine and Manual Method.

PubMed

Nelwan, Erni J; Indrasanti, Evi; Sinto, Robert; Nurchaida, Farida; Sosrosumihardjo, Rustadi

2016-01-01

to evaluate the performance of Vitek2 compact machine (Biomerieux Inc. ver 04.02, France) in reference to manual methods for susceptibility test for Candida resistance among HIV/AIDS patients. a comparison study to evaluate Vitek2 compact machine (Biomerieux Inc. ver 04.02, France) in reference to manual methods for susceptibility test for Candida resistance among HIV/AIDS patient was done. Categorical agreement between manual disc diffusion and Vitek2 machine was calculated using predefined criteria. Time to susceptibility result for automated and manual methods were measured. there were 137 Candida isolates comprising eight Candida species with C.albicans and C. glabrata as the first (56.2%) and second (15.3%) most common species, respectively. For fluconazole drug, among the C. albicans, 2.6% was found resistant on manual disc diffusion methods and no resistant was determined by Vitek2 machine; whereas 100% C. krusei was identified as resistant on both methods. Resistant patterns for C. glabrata to fluconazole, voriconazole and amphotericin B were 52.4%, 23.8%, 23.8% vs. 9.5%, 9.5%, 4.8% respectively between manual diffusion disc methods and Vitek2 machine. Time to susceptibility result for automated methods compared to Vitex2 machine was shorter for all Candida species. there is a good categorical agreement between manual disc diffusion and Vitek2 machine, except for C. glabrata for measuring the antifungal resistant. Time to susceptibility result for automated methods is shorter for all Candida species.

Candida antifungal drug resistance in sub-Saharan African populations: A systematic review

PubMed Central

Africa, Charlene Wilma Joyce; Abrantes, Pedro Miguel dos Santos

2017-01-01

Background: Candida infections are responsible for increased morbidity and mortality rates in at-risk patients, especially in developing countries where there is limited access to antifungal drugs and a high burden of HIV co-infection.  Objectives: This study aimed to identify antifungal drug resistance patterns within the subcontinent of Africa.  Methods: A literature search was conducted on published studies that employed antifungal susceptibility testing on clinical Candida isolates from sub-Saharan African countries using Pubmed and Google Scholar.  Results: A total of 21 studies from 8 countries constituted this review. Only studies conducted in sub-Saharan Africa and employing antifungal drug susceptibility testing were included. Regional differences in Candida species prevalence and resistance patterns were identified.  Discussion: The outcomes of this review highlight the need for a revision of antifungal therapy guidelines in regions most affected by Candida drug resistance.  Better controls in antimicrobial drug distribution and the implementation of regional antimicrobial susceptibility surveillance programmes are required in order to reduce the high Candida drug resistance levels seen to be emerging in sub-Saharan Africa. PMID:28154753

In vitro antifungal activity of terpinen-4-ol, eugenol, carvone, 1,8-cineole (eucalyptol) and thymol against mycotoxigenic plant pathogens.

PubMed

Morcia, C; Malnati, M; Terzi, V

2012-01-01

The aim of this study was to examine the effect of five naturally occurring compounds from essential oils on 10 different species of mycotoxigenic fungi involved in several plant diseases. The antifungal activities of terpinen-4-ol, eugenol, carvone, 1,8-cineole (eucalyptol) and thymol were observed in vitro on Fusarium subglutinans, Fusarium cerealis, Fusarium verticillioides, Fusarium proliferatum, Fusarium oxysporum, Fusarium sporotrichioides, Aspergillus tubingensis, Aspergillus carbonarius, Alternaria alternata and Penicillium sp. The naturally occurring compounds tested showed toxic effects on in vitro mycelium growth of all fungal species but with different level of potency. The results are encouraging for further investigations of in planta antifungal activities of these essential oils components.

Susceptibility of Candida albicans biofilms to azithromycin, tigecycline and vancomycin and the interaction between tigecycline and antifungals.

PubMed

Ku, Tsun Sheng N; Palanisamy, Suresh K A; Lee, Samuel A

2010-11-01

Despite growing data on antimicrobial lock therapy (ALT) in treating bacterial catheter-related bloodstream infections (CR-BSIs), ALT has not been established as a treatment option for CR-BSI caused by Candida albicans. Based on our finding that high-dose doxycycline exhibited antifungal activity against mature C. albicans biofilms, we evaluated additional antibacterial agents with Gram-positive activity [azithromycin, tigecycline (TIG) and vancomycin]. After screening these antibiotics, it was found that TIG had substantial antifungal activity against mature C. albicans biofilms. Therefore, TIG was assayed alone and in combination with fluconazole (FLC), amphotericin B (AmB) or caspofungin (CAS). TIG at 2048 μg/mL resulted in a >50% reduction in the growth of planktonic C. albicans cells. TIG inhibited the formation of biofilms from 128 μg/mL. Against mature biofilms, 2048 μg/mL TIG reduced metabolic activity by 84.2%. Furthermore, addition of 512 μg/mL TIG to FLC at all concentrations tested provided additional reduction in the metabolic activity of mature biofilms. However, this was not superior to 512 μg/mL TIG alone. TIG at 512 μg/mL increased the antifungal effect of lower concentrations of AmB (0.03125-0.25 μg/mL), but at 0.03125 μg/mL and 0.0625 μg/mL this effect was not superior to 512 μg/mL TIG alone. TIG inhibited the antifungal effect of higher concentrations of AmB (≥ 2 μg/mL). TIG at 512 μg/mL inhibited the antifungal activity of CAS at lower concentrations (0.25-8 μg/mL). These data indicate that high-dose TIG is highly active in vitro against planktonic cells, forming biofilms and mature biofilms of C. albicans. Published by Elsevier B.V.

Pharmacokinetics and Pharmacodynamics of Fluconazole for Cryptococcal Meningoencephalitis: Implications for Antifungal Therapy and In Vitro Susceptibility Breakpoints

PubMed Central

Sudan, Ajay; Livermore, Joanne; Howard, Susan J.; Al-Nakeeb, Zaid; Sharp, Andrew; Goodwin, Joanne; Gregson, Lea; Warn, Peter A.; Felton, Tim W.; Perfect, John R.; Harrison, Thomas S.

2013-01-01

Fluconazole is frequently the only antifungal agent that is available for induction therapy for cryptococcal meningitis. There is relatively little understanding of the pharmacokinetics and pharmacodynamics (PK-PD) of fluconazole in this setting. PK-PD relationships were estimated with 4 clinical isolates of Cryptococcus neoformans. MICs were determined using Clinical and Laboratory Standards Institute (CLSI) methodology. A nonimmunosuppressed murine model of cryptococcal meningitis was used. Mice received two different doses of fluconazole (125 mg/kg of body weight/day and 250 mg/kg of body weight/day) orally for 9 days; a control group of mice was not given fluconazole. Fluconazole concentrations in plasma and in the cerebrum were determined using high-performance liquid chromatography (HPLC). The cryptococcal density in the brain was estimated using quantitative cultures. A mathematical model was fitted to the PK-PD data. The experimental results were extrapolated to humans (bridging study). The PK were linear. A dose-dependent decline in fungal burden was observed, with near-maximal activity evident with dosages of 250 mg/kg/day. The MIC was important for understanding the exposure-response relationships. The mean AUC/MIC ratio associated with stasis was 389. The results of the bridging study suggested that only 66.7% of patients receiving 1,200 mg/kg would achieve or exceed an AUC/MIC ratio of 389. The potential breakpoints for fluconazole against Cryptococcus neoformans follow: susceptible, ≤2 mg/liter; resistant, >2 mg/liter. Fluconazole may be an inferior agent for induction therapy because many patients cannot achieve the pharmacodynamic target. Clinical breakpoints are likely to be significantly lower than epidemiological cutoff values. The MIC may guide the appropriate use of fluconazole. If fluconazole is the only option for induction therapy, then the highest possible dose should be used. PMID:23571544

In Vitro Antimicrobial Susceptibility of Brachyspira pilosicoli Isolates from Humans

PubMed Central

Brooke, C. J.; Hampson, D. J.; Riley, T. V.

2003-01-01

The in vitro antimicrobial susceptibility of the anaerobic intestinal spirochete Brachyspira pilosicoli was investigated by an agar dilution method. Human (n = 123) and porcine (n = 16) isolates were susceptible to metronidazole, ceftriaxone, meropenem, tetracycline, moxifloxacin, and chloramphenicol; erythromycin and ciprofloxacin were not active. Resistance to amoxicillin and clindamycin varied. Amoxicillin susceptibility was restored by clavulanic acid. PMID:12821498

Anti-fungal activity of cold and hot water extracts of spices against fungal pathogens of Roselle (Hibiscus sabdariffa) in vitro.

PubMed

Touba, Eslaminejad Parizi; Zakaria, Maziah; Tahereh, Eslaminejad

2012-02-01

Crude extracts of seven spices, viz. cardamom, chilli, coriander, onion, garlic, ginger, and galangale were made using cold water and hot water extraction and they were tested for their anti-fungal effects against the three Roselle pathogens i.e. Phoma exigua, Fusarium nygamai and Rhizoctonia solani using the 'poisoned food technique'. All seven spices studied showed significant anti-fungal activity at three concentrations (10, 20 and 30% of the crude extract) in-vitro. The cold water extract of garlic exhibited good anti-fungal activity against all three tested fungi. In the case of the hot water extracts, garlic and ginger showed the best anti-fungal activity. Of the two extraction methods, cold water extraction was generally more effective than hot water extraction in controlling the pathogens. Against P. exigua, the 10% cold water extracts of galangale, ginger, coriander and cardamom achieved total (100%) inhibition of pathogen mycelial growth. Total inhibition of F. nygamai mycelial growth was similarly achieved with the 10% cold water extracts garlic. Against R. solani, the 10% cold water extract of galangale was effective in imposing 100% inhibition. Accordingly, the 10% galangale extract effectively controlled both P. exigua and R. solani in vitro. None of the hot water extracts of the spices succeeded in achieving 100% inhibition of the pathogen mycelial growth. Copyright © 2011 Elsevier Ltd. All rights reserved.

Molecular Identification and Antifungal Susceptibility Pattern of Non-albicans Candida Species Isolated from Vulvovaginal Candidiasis

PubMed Central

Nejat, Ziba Abbasi; Farahyar, Shirin; Falahati, Mehraban; Khozani, Mahtab Ashrafi; Hosseini, Aga Fateme; Faiazy, Azamsadat; Ekhtiari, Masoome; Hashemi-Hafshenjani, Saeideh

2018-01-01

Background: Vulvovaginal candidiasis (VVC) is an important health problem caused by Candida spp. The aim of this study was molecular identification, phylogenetic analysis, and evaluation of antifungal susceptibility of non-albicans Candida isolates from VVC. Methods: Vaginal secretion samples were collected from 550 vaginitis patients at Sayyad Shirazi Medical and Educational Center of Gorgan (Golestan Province, Iran) from May to October 2015. Samples were analyzed using conventional mycological and molecular approaches. Clinical isolates were analyzed with specific PCR using CGL primers, and the internal transcribed spacer region and the D1-D2 domain of the large-subunit rRNA gene were amplified and sequenced. Susceptibility to amphotericin B, fluconazole, itraconazole, and clotrimazole was determined by the guidelines of the Clinical and Laboratory Standard Institute. Results: In total, 35 non-albicans Candida isolates were identified from VVC patients. The isolates included 27 strains of Candida glabrata (77.1%), 5 Candida krusei (Pichia kudriavzevii; 14.3%), 2 Candida kefyr (Kluyveromyces marxianus; 5.7%), and 1 Candida lusitaniae (Clavispora lusitaniae; 2.9%). The fungicides itraconazole and amphotericin B were effective against all species. One isolate of C. glabrata showed resistance to fluconazole and clotrimazole, and 26 isolates of C. glabrata indicated dose-dependent susceptibility to fluconazole. C. lusitaniae was susceptible in a dose-dependent manner to fluconazole and resistant to clotrimazole. Conclusions: Non-albicans Candida spp. are common agents of vulvovaginitis, and C. glabrata is the most common species in the tested patients. PMID:28688376

Molecular Identification and Antifungal Susceptibility Patterns of Clinical Dermatophytes Following CLSI and EUCAST Guidelines

PubMed Central

Dabas, Yubhisha; Xess, Immaculata; Singh, Gagandeep; Pandey, Mragnayani; Meena, Suneeta

2017-01-01

Dermatophytes are associated with superficial infections in humans worldwide. The aim of the present study was to determine the species distribution and susceptibility patterns of clinical dermatophytes. Samples received for routine mycological processing from 124 suspected cases attending a dermatologic clinic in a tertiary care hospital were included in the study. On direct microscopy, 74.1% (92/124) were positive and 53.2% (66/124) grew on culture. The isolates were comprised of Trichophyton interdigitale (56%) followed by Trichophyton tonsurans (25.7%), Trichophyton rubrum (7.5%), Trichophyton violaceum (4.5%), Microsporum gypseum (4.5%), and Trichophyton verrucosum (1.5%). Conventional mycological identification was concordant with ITS sequencing except for T. mentagrophytes. High minimum inhibitory concentration (MIC) values (geometric mean, >1 µg/mL) were observed for T. tonsurans and T. rubrum to terbinafine and griseofulvin. This study highlights the shift in epidemiology from T. rubrum to T. interdigitale. It also raises a concern of high MICs of terbinafine and griseofulvin among our isolates. Surveillance of antifungal susceptibility patterns can provide clinicians with local MIC data that can further aid in guiding better management in relapse cases of dermatomycosis. PMID:29371535

In Vitro Activities of Eight Antifungal Drugs against 106 Waterborne and Cutaneous Exophiala Species

PubMed Central

Najafzadeh, M. J.; Saradeghi Keisari, M.; Vicente, V. A.; Feng, P.; Shamsian, S. A. A.; Rezaei-Matehkolaei, A.; de Hoog, G. S.; Curfs-Breuker, I.

2013-01-01

The in vitro activities of eight antifungal drugs against 106 clinical and environmental isolates of waterborne and cutaneous Exophiala species were tested. The MICs and minimum effective concentrations for 90% of the strains tested (n = 106) were, in increasing order, as follows: posaconazole, 0.063 μg/ml; itraconazole, 0.25 μg/ml; micafungin, 1 μg/ml; voriconazole, 2 μg/ml; isavuconazole, 4 μg/ml; caspofungin, 8 μg/ml; amphotericin B, 16 μg/ml; fluconazole, 64 μg/ml. PMID:24100491

[The in vitro antifungal activities of fluconazole against pathogenic yeasts recently isolated from clinical specimens].

PubMed

Yamaguchi, H; Igari, J; Kume, H; Abe, M; Oguri, T; Kanno, H; Kawakami, S; Okuzumi, K; Fukayama, M; Ito, A; Kawata, K; Uchida, K

1997-09-01

The emergence of Candida albicans resistance to azole antifungal agents have been reported in the U. S. and Europe. We examined the in vitro antifungal activities of fluconazole against clinical isolates collected by seven investigators in three years to examine if a tendency existed toward the development of azole-resistance among fungal isolates in Japan. The following results were obtained: 1. Sensitivities to fluconazole (FLCZ) were determined for yeast-like fungi, including 113 strains isolated in 1993, 149 strains isolated in 1994 and 205 strains isolated in 1995. No significant differences in sensitivities in the three years were detected. 2. Minimum inhibitory concentrations of FLCZ were 0.1-0.78 microgram/ml for C. albicans and 3.13-25 micrograms/ml for C. glabrata. Strains with 25 micrograms/ml of FLCZ's MIC were detected; two strains of C. krusei and one strain each of C. krusei, Trichospron beigelii and Hansenula anomala. No strains with higher than 50 micrograms/ml MIC of FLCZ were detected. 3. In vitro activities of FLCZ were compared between clinical strains isolated between 1993 and 1995 and clinical strains isolated before the marketing of FLCZ (up to December 1987) or clinical yeasts isolated between 1991 and 1992. No significant differences were observed, suggesting that no tendency existed toward azole resistance among fungal strains examined.

Chemical Composition and in Vitro Antifungal Activity Screening of the Allium ursinum L. (Liliaceae)

PubMed Central

Bagiu, Radu Vasile; Vlaicu, Brigitha; Butnariu, Monica

2012-01-01

The objective of the study was to summarize the methods for isolating and identifying natural sulfur compounds from Allium ursinum (ramson) and to discuss the active constituents with regard to antifungal action. Using chromatographic techniques, the active constituents were isolated and subsequently identified. Analyses by high-performance liquid chromatography (HPLC) suggested that these compounds were sulfur constituents, with a characteristic absorbance at 250 nm. Gas chromatography-mass spectrometry (GC-MS) analyses allowed the chemical structures of the isolated constituents to be postulated. We adopted the same methods to identify the health-giving profiling of ramsons and the effects are thought to be primarily derived from the presence and breakdown of the alk(en)ylcysteine sulphoxide, alliin and its subsequent breakdown to allicin (sulfur-compounds of ramson) in connection with antifungal action. The aim of the study was the characterization of the chemical composition of ramsons and the testing of the action of the in vitro extracts, on different strains of Candida albicans. The main goal was to highlight the most efficient extracts of Allium ursinum that can provide long-term antifungal activity without remissions. The extracts from Allium ursinum plants, inhibited growth of Candida spp. cells at concentrations ranging from 0.5 to 4.0 mg/mL, while that of adherent cells at concentrations ranging from 1.0 to > 4.0 mg/mL, depending on the yeast and plant species. PMID:22408399

Antifungal susceptibilities of Candida glabrata species complex, Candida krusei, Candida parapsilosis species complex and Candida tropicalis causing invasive candidiasis in China: 3 year national surveillance.

PubMed

Xiao, Meng; Fan, Xin; Chen, Sharon C-A; Wang, He; Sun, Zi-Yong; Liao, Kang; Chen, Shu-Lan; Yan, Yan; Kang, Mei; Hu, Zhi-Dong; Chu, Yun-Zhuo; Hu, Tie-Shi; Ni, Yu-Xing; Zou, Gui-Ling; Kong, Fanrong; Xu, Ying-Chun

2015-03-01

To define the antifungal susceptibility patterns of the most common non-albicans Candida spp. in China. We evaluated the susceptibilities to nine antifungal drugs of Candida parapsilosis species complex, Candida tropicalis, Candida glabrata species complex and Candida krusei isolates from patients with invasive candidiasis at 11 hospitals over 3 years. Isolates were identified by MALDI-TOF MS supplemented by DNA sequencing. MICs were determined by Sensititre YeastOne(TM) using current clinical breakpoints/epidemiological cut-off values to assign susceptibility (or WT), and by CLSI M44-A2 disc diffusion for fluconazole and voriconazole. Of 1072 isolates, 392 (36.6%) were C. parapsilosis species complex. C. tropicalis, C. glabrata species complex and C. krusei comprised 35.4%, 24.3% and 3.7% of the isolates, respectively. Over 99.3% of the isolates were of WT phenotype to amphotericin B and 5-flucytosine. Susceptibility/WT rates to azoles among C. parapsilosis species complex were ≥97.5%. However, 11.6% and 9.5% of C. tropicalis isolates were non-susceptible to fluconazole and voriconazole, respectively (7.1% were resistant to both). Approximately 14.3% of C. glabrata sensu stricto isolates (n = 258) were fluconazole resistant, and 11.6% of C. glabrata sensu stricto isolates were cross-resistant to fluconazole and voriconazole. All C. krusei isolates were susceptible/WT to voriconazole, posaconazole and itraconazole. Overall, 97.7%-100% of isolates were susceptible to caspofungin, micafungin and anidulafungin, but 2.3% of C. glabrata were non-susceptible to anidulafungin. There was no azole/echinocandin co-resistance. Disc diffusion and Sensititre YeastOne(TM) methods showed >95% categorical agreement for fluconazole and voriconazole. In summary, reduced azole susceptibility was seen among C. tropicalis. Resistance to echinocandins was uncommon. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial

Synthesis of natural acylphloroglucinol-based antifungal compounds against Cryptococcus species

USDA-ARS?s Scientific Manuscript database

Thirty-five analogs of naturally occurring acylphloroglucinols were designed and synthesized to identify antifungal compounds against Cryptococcus spp. that causes the life-threatening disseminated cryptococcosis. In vitro antifungal testing showed that 17 compounds were active against C. neoformans...

In vitro and in silico antifungal efficacy of nitrogen-doped carbon nanohorn (NCNH) against Rhizoctonia solani.

PubMed

Dharni, Seema; Sanchita; Unni, SreeKuttan M; Kurungot, Sreekumar; Samad, Abdul; Sharma, Ashok; Patra, Dharani Dhar

2016-01-01

We have investigated in vitro antifungal efficiency of nitrogen-doped carbon nanohorn (NCNH) against Rhizoctonia solani (R. solani) plant pathogenic fungi. NCNH with size of 50-60 nm and concentrations of 10, 50, 100, and 150 μg mL(-1) were used. The results showed that growth of fungi in the presence of NCNH was significantly (p > .05) inhibited at 150 μg mL(-1) (85.13 ± .97) after 72 h. The results were validated through computational approaches. Molecular docking analysis of NCNH with endochitinase protein of R. solani was performed to validate the potential of antifungal activity of NCNH. Docking results showed different conformations of interaction of NCNH with endochitinase enzyme. The conformation with least binding energy -13.54 kcal/mol was considered further. It is likely that NCNH interacts with the pathogens by mechanically wrapping, which may be one of the major toxicity actions of NCNH against R. solani. The analysis showed that NCNH might interwinds to endochitinase of R. solani leading to the deactivation of the enzyme. To best of our knowledge, this is the first report of antifungal efficacy of NCNH against R. solani and provides useful information about the application of NCNH in resisting crop disease.

Antifungal-protein production in maize (Zea mays) suspension cultures.

PubMed

Perri, Fabio; Della Penna, Serena; Rufini, Francesca; Patamia, Maria; Bonito, Mariantonietta; Angiolella, Letizia; Vitali, Alberto

2009-04-01

The growing emergency due to the phenomenon of drug resistance to micro-organisms has pushed forward the search for new potential drug alternatives to those already in use. Plants represent a suitable source of new antifungal molecules, as they produce a series of defensive proteins. Among them are the PRPs (pathogenesis-related proteins), shown to be effective in vitro against human pathogens. An optimized and established cell-suspension culture of maize (Zea mays) was shown to constitutively secrete in the medium a series of PRPs comprising the antifungal protein zeamatin (P33679) with a final yield of approx. 3 mg/litre. The in-vitro-produced zeamatin possessed antifungal activity towards a clinical strain of the human pathogenic yeast Candida albicans, an activity comparable with the one reported for the same protein extracted from maize seeds. Along with zeamatin, other PRPs were expressed: a 9 kDa lipid-transfer protein, a 26 kDa xylanase inhibitor and a new antifungal protein, PR-5. A fast, two-step chromatographic procedure was set up allowing the complete purification of the proteins considered, making this cell line a valuable system for the production of potential antifungal agents in a reliable and easy way.

Activation of murine invariant NKT cells promotes susceptibility to candidiasis by IL-10 induced modulation of phagocyte antifungal activity.

PubMed

Haraguchi, Norihiro; Kikuchi, Norihiro; Morishima, Yuko; Matsuyama, Masashi; Sakurai, Hirofumi; Shibuya, Akira; Shibuya, Kazuko; Taniguchi, Masaru; Ishii, Yukio

2016-07-01

Invariant NKT (iNKT) cells play an important role in a variety of antimicrobial immune responses due to their ability to produce high levels of immune-modulating cytokines. Here, we investigated the role of iNKT cells in host defense against candidiasis using Jα18-deficient mice (Jα18(-/-) ), which lack iNKT cells. Jα18(-/-) mice were more resistant to the development of lethal candidiasis than wild-type (WT) mice. In contrast, treatment of WT mice with the iNKT cell activating ligand α-galactosylceramide markedly enhanced their mortality after infection with Candida albicans. Serum IL-10 levels were significantly elevated in WT mice in response to infection with C. albicans. Futhermore, IL-10 production increased after in vitro coculture of peritoneal macrophages with iNKT cells and C. albicans. The numbers of peritoneal macrophages, the production of IL-1β and IL-18, and caspase-1 activity were also significantly elevated in Jα18(-/-) mice after infection with C. albicans. The adoptive transfer of iNKT cells or exogenous administration of IL-10 into Jα18(-/-) reversed susceptibility to candidiasis to the level of WT mice. These results suggest that activation of iNKT cells increases the initial severity of C. albicans infection, most likely mediated by IL-10 induced modulation of macrophage antifungal activity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Molecular epidemiology and antifungal susceptibility of Candida species isolated from urine samples of patients in intensive care unit].

PubMed

Yüksekkaya, Serife; Fındık, Duygu; Arslan, Uğur

2011-01-01

The aims of this study were to analyse the amphotericin B and fluconazole susceptibility and molecular epidemiology of Candida strains (Candida albicans, Candida tropicalis and Candida glabrata) isolated from the urine samples of patients hospitalized in the intensive care unit. Identification of the isolates was done according to microscopic morphology (chlamydospor, blastospor, pseudohyphae and true hyphae) on cornmeal agar, germ tube formation and carbohydrate assimilation patterns (API ID 32C bioMérieux, France). Antifungal susceptibilities of the isolates were determined by in vitro broth microdilution method recommended by Clinical and Laboratory Standards Institute (CLSI). To investigate the clonal relationship of the isolates, randomly amplified polymorphic DNA (RAPD) analysis was performed by using Cnd3 primer. Of the 56 Candida isolates minimum inhibitory concentration (MIC) ranges, MIC50 and MIC90 values for amphotericin B were 0.125-1 µg/ml, 0.125 and 0.5 µg/ml for C.albicans, 0.125-1 µg/ml, 0.25 and 1 µg/ml for C.tropicalis and 0.125-1 µg/ml, 0.25 and 1 µg/ml for C.glabrata, respectively. Fluconazole MIC ranges, MIC50 and MIC90 values were 0.25-4 µg/ml, 0.25 and 0.5 µg/ml for C.albicans, 0.25-16 µg/ml, 0.5 and 1 µg/ml for C.tropicalis and 0.5-64 µg/ml, 8 and 16 µg/ml for C.glabrata, respectively. For amphotericin B, none of the isolates had high MIC values (MIC > 1 µg/ml). While one of the C.glabrata isolates was resistant to fluconazole (MIC ≥ 64 µg/ml), one C.tropicalis and two C.glabrata isolates were dose-dependent susceptible (MIC: 16-32 µg/ml). The results of RAPD analysis indicated an exogenous spread from two clones for C.albicans, one clone for C.glabrata and one clone for C.tropicalis. This study underlines the importance of molecular epidemiological analysis of clinical samples together with hospital environmental samples in terms of Candida spp. To determine the exogenous origin for the related strains and to prevent

Antifungal Susceptibility Testing of Aspergillus spp. by Using a Composite Correlation Index (CCI)-Based Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Method Appears To Not Offer Benefit over Traditional Broth Microdilution Testing

PubMed Central

Gitman, Melissa R.; McTaggart, Lisa; Spinato, Joanna; Poopalarajah, Rahgavi; Lister, Erin; Husain, Shahid

2017-01-01

ABSTRACT Aspergillus spp. cause serious invasive lung infections, and Aspergillus fumigatus is the most commonly encountered clinically significant species. Voriconazole is considered to be the drug of choice for treating A. fumigatus infections; however, rising resistance rates have been reported. We evaluated a matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS)-based method for the differentiation between wild-type and non-wild-type isolates of 20 Aspergillus spp. (including 2 isolates of Aspergillus ustus and 1 of Aspergillus calidoustus that were used as controls due their intrinsic low azole susceptibility with respect to the in vitro response to voriconazole). At 30 and 48 h of incubation, there was complete agreement between Cyp51A sequence analysis, broth microdilution, and MALDI-TOF MS classification of isolates as wild type or non-wild type. In this proof-of-concept study, we demonstrated that MALDI-TOF MS can be used to accurately detect A. fumigatus strains with reduced voriconazole susceptibility. However, rather than proving to be a rapid and simple method for antifungal susceptibility testing, this particular MS-based method showed no benefit over conventional testing methods. PMID:28404678

Antifungal Susceptibility Testing of Aspergillus spp. by Using a Composite Correlation Index (CCI)-Based Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Method Appears To Not Offer Benefit over Traditional Broth Microdilution Testing.

PubMed

Gitman, Melissa R; McTaggart, Lisa; Spinato, Joanna; Poopalarajah, Rahgavi; Lister, Erin; Husain, Shahid; Kus, Julianne V

2017-07-01

Aspergillus spp. cause serious invasive lung infections, and Aspergillus fumigatus is the most commonly encountered clinically significant species. Voriconazole is considered to be the drug of choice for treating A. fumigatus infections; however, rising resistance rates have been reported. We evaluated a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based method for the differentiation between wild-type and non-wild-type isolates of 20 Aspergillus spp. (including 2 isolates of Aspergillus ustus and 1 of Aspergillus calidoustus that were used as controls due their intrinsic low azole susceptibility with respect to the in vitro response to voriconazole). At 30 and 48 h of incubation, there was complete agreement between Cyp51A sequence analysis, broth microdilution, and MALDI-TOF MS classification of isolates as wild type or non-wild type. In this proof-of-concept study, we demonstrated that MALDI-TOF MS can be used to accurately detect A. fumigatus strains with reduced voriconazole susceptibility. However, rather than proving to be a rapid and simple method for antifungal susceptibility testing, this particular MS-based method showed no benefit over conventional testing methods. © Crown copyright 2017.

Selected Essential Oils as Antifungal Agents Against Antibiotic-Resistant Candida spp.: In Vitro Study on Clinical and Food-Borne Isolates.

PubMed

Rajkowska, Katarzyna; Kunicka-Styczyńska, Alina; Maroszyńska, Marta

2017-01-01

Candida spp. cause significant health problems, inducing various types of superficial and deep-seated mycoses in humans. As a result of the increasing antibiotic resistance among pathogenic yeasts, the interest in alternative agents of antifungal activity is growing. This study evaluated the antimicrobial activity of selected essential oils (EOs) against Candida clinical and food-borne strains, including antibiotic-resistant isolates, in relation to yeast cell surface hydrophobicity (CSH). Candida strains showed different range of susceptibility to tea tree, thyme, peppermint, and clove oils, and peppermint oil demonstrated the lowest anticandidal activity with minimal inhibitory concentrations (MICs) of 0.03-8.0% v/v. MIC values for thyme and clove oils ranged from 0.03% to 0.25% v/v, and for tea tree oil-from 0.12% to 2.0% v/v. The exception was Candida tropicalis food-borne strain, the growth of which was inhibited after application of EOs at concentration of 8% v/v. Due to diverse yeast susceptibility to EOs, isolates were divided into five clusters in a principal component analysis model, each containing both clinical and food-borne strains. Hydrophobic properties of yeast were also diversified, and 37% of clinical and 50% of food-borne strains exhibited high hydrophobicity. The study indicates high homology of clinical and food-borne Candida isolates in relation to their susceptibility to anticandidal agents and hydrophobic properties. The susceptibility of yeasts to EOs could be partially related to their CSH. High antifungal activity of examined EOs, also against antibiotic-resistant isolates, indicates their usefulness as agents preventing the development of Candida strains of different origin.

[Confirming the Utility of RAISUS Antifungal Susceptibility Testing by New-Software].

PubMed

Ono, Tomoko; Suematsu, Hiroyuki; Sawamura, Haruki; Yamagishi, Yuka; Mikamo, Hiroshige

2017-08-15

Clinical and Laboratory Standards Institute (CLSI) methods for susceptibility tests of yeast are used in Japan. On the other hand, the methods have some disadvantage; 1) reading at 24 and 48 h, 2) using unclear scale, approximately 50% inhibition, to determine MICs, 3) calculating trailing growth and paradoxical effects. These makes it difficult to test the susuceptibility for yeasts. Old software of RAISUS, Ver. 6.0 series, resolved problem 1) and 2) but did not resolve problem 3). Recently, new software of RAISUS, Ver. 7.0 series, resolved problem 3). We confirmed that using the new software made it clear whether all these issue were settled or not. Eighty-four Candida isolated from Aichi Medical University was used in this study. We compared the MICs obtained by using RAISUS antifungal susceptibility testing of yeasts RSMY1, RSMY1, with those obtained by using ASTY. The concordance rates (±four-fold of MICs) between the MICs obtained by using ASTY and RSMY1 with the new software were more than 90%, except for miconazole (MCZ). The rate of MCZ was low, but MICs obtained by using CLSI methods and Yeast-like Fungus DP 'EIKEN' methods, E-DP, showed equivalent MICs of RSMY1 using the new software. The frequency of skip effects on RSMY1 using the new software markedly decreased relative to RSMY1 using the old software. In case of showing trailing growth, the new software of RAISUS made it possible to choice the correct MICs and to put up the sign of trailing growth on the result screen. New software of RAISUS enhances its usability and the accuracy of MICs. Using automatic instrument to determine MICs is useful to obtain objective results easily.

In Vitro Susceptibility of the Relapsing-Fever Spirochete Borrelia miyamotoi to Antimicrobial Agents

PubMed Central

Draga, Ronald O. P.; Wagemakers, Alex; Manger, Annemijn; Oei, Anneke; Visser, Caroline E.; Hovius, Joppe W.

2017-01-01

ABSTRACT Hard-tick-borne relapsing fever (HTBRF) is an emerging infectious disease throughout the temperate zone caused by the relapsing-fever spirochete Borrelia miyamotoi. Antibiotic treatment of HTBRF is empirically based on the treatment of Lyme borreliosis; however, the antibiotic susceptibility of B. miyamotoi has not been studied to date. Thus, we set out to determine the in vitro antimicrobial susceptibility of B. miyamotoi. A microdilution method with 96-well microtiter plates was used to determine the antibiotic susceptibilities of two B. miyamotoi strains isolated on two different continents (Asia and North America), two Borrelia burgdorferi sensu lato strains, and one Borrelia hermsii isolate for purposes of comparison. The MIC and minimal bactericidal concentration (MBC) were determined by both microscopy and colorimetric assays. We were able to show that relative to the B. burgdorferi sensu lato isolates, both B. miyamotoi strains and B. hermsii demonstrated greater susceptibility to doxycycline and azithromycin, equal susceptibility to ceftriaxone, and resistance to amoxicillin in vitro. The MIC and MBC of amoxicillin for B. miyamotoi evaluated by microscopy were 16 to 32 mg/liter and 32 to 128 mg/liter, respectively. Since B. miyamotoi is susceptible to doxycycline, azithromycin, and ceftriaxone in vitro, our data suggest that these antibiotics can be used for the treatment of HTBRF. Oral amoxicillin is currently used as an alternative for the treatment of HTBRF; however, since we found that the B. miyamotoi strains tested were resistant to amoxicillin in vitro, this issue warrants further study. PMID:28674060

In Vitro Susceptibility of the Relapsing-Fever Spirochete Borrelia miyamotoi to Antimicrobial Agents.

PubMed

Koetsveld, Joris; Draga, Ronald O P; Wagemakers, Alex; Manger, Annemijn; Oei, Anneke; Visser, Caroline E; Hovius, Joppe W

2017-09-01

Hard-tick-borne relapsing fever (HTBRF) is an emerging infectious disease throughout the temperate zone caused by the relapsing-fever spirochete Borrelia miyamotoi Antibiotic treatment of HTBRF is empirically based on the treatment of Lyme borreliosis; however, the antibiotic susceptibility of B. miyamotoi has not been studied to date. Thus, we set out to determine the in vitro antimicrobial susceptibility of B. miyamotoi A microdilution method with 96-well microtiter plates was used to determine the antibiotic susceptibilities of two B. miyamotoi strains isolated on two different continents (Asia and North America), two Borrelia burgdorferi sensu lato strains, and one Borrelia hermsii isolate for purposes of comparison. The MIC and minimal bactericidal concentration (MBC) were determined by both microscopy and colorimetric assays. We were able to show that relative to the B. burgdorferi sensu lato isolates, both B. miyamotoi strains and B. hermsii demonstrated greater susceptibility to doxycycline and azithromycin, equal susceptibility to ceftriaxone, and resistance to amoxicillin in vitro The MIC and MBC of amoxicillin for B. miyamotoi evaluated by microscopy were 16 to 32 mg/liter and 32 to 128 mg/liter, respectively. Since B. miyamotoi is susceptible to doxycycline, azithromycin, and ceftriaxone in vitro , our data suggest that these antibiotics can be used for the treatment of HTBRF. Oral amoxicillin is currently used as an alternative for the treatment of HTBRF; however, since we found that the B. miyamotoi strains tested were resistant to amoxicillin in vitro , this issue warrants further study. Copyright © 2017 American Society for Microbiology.

In vitro susceptibility of Prototheca spp. to gentamicin.

PubMed Central

Shahan, T A; Pore, R S

1991-01-01

One hundred strains of Prototheca zopfii, Prototheca wickerhamii, Prototheca moriformis, Prototheca stagnora, and Prototheca ulmnea; five strains of Chlorella protothecoides; and two strains of Candida albicans were obtained from a number of different clinical and environmental sources and were tested for their in vitro susceptibility to the antibacterial agent gentamicin. All Prototheca strains were susceptible to gentamicin at concentrations between 0.3 and 0.9 micrograms/ml. A modified macrobroth dilution MIC assay with a colorimeter and a microbroth dilution assay with a 96-well plate reader were the two methods used to determine the MICs. PMID:1804021

Evaluation of the antifungal effect of EDTA, a metal chelator agent, on Candida albicans biofilm.

PubMed

Casalinuovo, I A; Sorge, R; Bonelli, G; Di Francesco, P

2017-03-01

Candida albicans biofilm is frequently found on artificial surfaces and the infections related to biofilm are difficult to eliminate, as they require the removal of artificial devices and treatment with antifungal drugs. Nowadays, fungal growth in biofilms is difficult to eradicate with conventional antifungal drugs such as fluconazole. Among chelating agents, disodium salt-Ethylene Diamine Tetraacetic Acid (EDTA) is known to have antifungal activity. In this study, we examined the in vitro activity of the EDTA and the antifungal drug fluconazole against C. albicans mature biofilm. C. albicans ATCC 20191, fluconazole-susceptible strain, was grown at an inoculum starter of 1 x 106 cells/ml for 72 h in 24-well microtiter plates and was further treated for 24 h with EDTA and/or fluconazole. Antifungal activities in biofilms were expressed as reduction in optical density (OD) determined by a 2,3-bis (2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide (XTT) colorimetric assay and compared to untreated biofilms. Colorimetric readings revealed that EDTA alone (at 25 and 2.5 mM) significantly reduced fungal metabolic activity in preformed biofilms. Also, EDTA combined with fluconazole significantly reduced the growth of biofilm when compared to biofilm treated with fluconazole alone (at 25 and 2.5 µg/ml). Our data suggest that the employment of EDTA or other chemicals destabilizers of the biofilm matrix, in combination with antifungal drugs, could lead to the development of new strategies for the management of infections associated to Candida biofilm. Another relevant result of our study suggests that the initial cell concentration, probably through mechanisms of quorum sensing, affects the cellular viability during the process of biofilm formation.

Breakthrough candidemia after the introduction of broad spectrum antifungal agents: A 5-year retrospective study.

PubMed

Breda, Giovanni L; Tuon, Felipe F; Meis, Jacques F; Herkert, Patricia F; Hagen, Ferry; de Oliveira, Letícia Z; Dias, Viviane de Carvalho; da Cunha, Clóvis Arns; Queiroz-Telles, Flávio

2018-06-01

Candidemia is the main invasive fungal disease among hospitalized patients. Several breakthrough candidemia (BrC) cases have been reported, but few studies evaluate the epidemiology, risk factors, molecular characterization, antifungal susceptibility profile and outcome of those patients, especially in developing countries and including patients using broad spectrum antifungals. We conducted a retrospective study from 2011 to 2016, including patients aged 12 years or older with candidemia. Epidemiological characteristics and risk factors for candidemia were evaluated and compared with patients with BrC using univariate and multivariate analysis. Sequential Candida isolates from BrC were identified by internal transcribed spacer sequencing, genotyped with amplified fragment length polymorphism fingerprinting (AFLP), and tested for antifungal susceptibility. From 148 candidemia episodes, 27 breakthrough episodes (18%) were identified, with neutropenia and mucositis being independent risk factors for BrC. Candida non-albicans was more frequent in the BrC group (P < .001). AFLP showed high correlation with conventional methods of identification among breakthrough isolates and a high genetic similarity among isolates from the same patient was observed. C. albicans was the most susceptible species with low MIC values for all antifungal agents tested. In contrast, we found isolates of C. glabrata, C. parapsilosis and C. tropicalis resistant to triazoles and echinocandins. In conclusion, BrC occurred mainly in severely immunosuppressed patients, with neutropenia and mucositis. Mortality did not differ between the groups. Candida non-albicans species were more recovered from BrC, with C. albicans being the most susceptible to antifungals.

Antifungal activity of Piper diospyrifolium Kunth (Piperaceae) essential oil

PubMed Central

Vieira, Silvia Cristina Heredia; de Paulo, Luis Fernando; Svidzinski, Terezinha Inez Estivaleti; Dias Filho, Benedito Prado; Nakamura, Celso Vataru; de Souza, Amanda; Young, Maria Cláudia Marx; Cortez, Diógenes Aparício Garcia

2011-01-01

In vitro activity of the essential oil from Piper diospyrifolium leaves was tested using disk diffusion techniques. The antifungal assay showed significant potencial antifungal activity: the oil was effective against several clinical fungal strains. The majority compounds in the essential oil were identified as sesquiterpenoids by GC-MS and GC-FID techniques. PMID:24031717

In Vitro Susceptibilities of Mycoplasma hyopneumoniae Field Isolates

PubMed Central

Vicca, J.; Stakenborg, T.; Maes, D.; Butaye, P.; Peeters, J.; de Kruif, A.; Haesebrouck, F.

2004-01-01

The in vitro susceptibilities of 21 Mycoplasma hyopneumoniae field isolates were determined using a broth microdilution technique. One isolate showed acquired resistance to lincomycin, tilmicosin, and tylosin, while five isolates were resistant to flumequine and enrofloxacin. Acquired resistance against these antimicrobials in M. hyopneumoniae field isolates was not reported previously. PMID:15504886

Antifungal activity of Zataria multiflora essential oil-loaded solid lipid nanoparticles in-vitro condition.

PubMed

Nasseri, Mahboobeh; Golmohammadzadeh, Shiva; Arouiee, Hossein; Jaafari, Mahmoud Reza; Neamati, Hossein

2016-11-01

The aim of the present study was to prepare, characterize, and evaluate solid lipid nanoparticles (SLNs) containing Zataria multiflora essential oil (ZEO). In this study, Z. multiflora essential oil-loaded solid lipid nanoparticles (ZE-SLNs) were prepared to improve its efficiency in controlling some fungal pathogens. SLNs containing Z. multiflora essential oil were prepared by high shear homogenization and ultra sound technique. ZEO-SLNs contained 0.03% ZEO in 5% of lipid phase (Glyceryl monostearate-GMS and Precirol® ATO 5). Tween 80 and Poloxamer 188 (2.5% w/v) were used as surfactant in the aqueous phase. The antifungal efficacy of ZE-SLNs and ZEO was compared under in vitro conditions. The particle size of ZE-SLNs was around 255.5±3 nm with PDI of 0.369±0.05 and zeta potential was about -37.8±0.8 mV. Encapsulation efficacy of ZE-SLNs in crystalline form was 84±0.92%. The results showed that the ZEO and ZE-SLNs had 54 and 79% inhibition on the growth of fungal pathogens, respectively. The minimum inhibitory concentration (MIC) under in vitro conditions for the ZEO on the fungal pathogens of Aspergillus ochraceus, Aspergillus niger, Aspergillus flavus, Alternaria solani, Rhizoctonia solani, and Rhizopus stolonifer was 300, 200, 300, 200, 200 and 200 ppm, respectively, for ZE-SLNs, it was 200, 200, 200, 100, 50 and 50 ppm. The antifungal efficacy of ZE-SLNs was significantly more than ZEO. Our results showed that the SLNs were suitable carriers for Z. multiflora essential oil in controlling the fungal pathogens and merits further investigation.

Bovine Serum Albumin Nanoparticles Containing Amphotericin B: Characterization, Cytotoxicity and In Vitro Antifungal Evaluation.

PubMed

Casa, Diani Meza; Karam, Thaysa Ksiaskiewcz; Alves, Aline de Cristo Soares; Zgoda, Aline Aparecida; Khalil, Najeh Maissar; Mainardes, Rubiana Mara

2015-12-01

In this study, nanoparticles based on bovine serum albumin (BSA) containing amphotericin B (AmB) were obtained by the desolvation method and characterized with respect to size, size distribution, AmB encapsulation efficiency, AmB state of aggregation, and AmB in vitro release profile. After, the effect of nanoparticles on the cytotoxicity of human erythrocytes in vitro and efficacy over strains of Candida spp. were evaluated. The mean particle size was 156 nm and the AmB encapsulation efficiency was over 82%. The in vitro release profile revealed a sustained release of approximately 48% of AmB over 5 days. AmB is present in BSA nanoparticles as monomer. AmB-loaded nanoparticles showed very low index of hemolysis (less than 8%) in 72 h of assay compared to free AmB, which presented 100% of hemolysis in 2 h of incubation. The AmB-loaded BSA nanoparticles were as effective as free AmB against Candida albicans and Candida tropicalis, considering their sustained release profile. Thus, BSA nanoparticles are potential carriers for AmB, reducing its molecular aggregation and prolonging its release, resulting in lower cytotoxicity while maintaining its antifungal activity.

Antifungal activity of Andrographis paniculata extracts and active principles against skin pathogenic fungal strains in vitro.

PubMed

Sule, Abubakar; Ahmed, Qamar Uddin; Latip, Jalifah; Samah, Othman Abd; Omar, Muhammad Nor; Umar, Abdulrashid; Dogarai, Bashar Bello S

2012-07-01

Andrographis paniculata Nees. (Acanthaceae) is an annual herbaceous plant widely cultivated in southern Asia, China, and Europe. It is used in the treatment of skin infections in India, China, and Malaysia by folk medicine practitioners. Antifungal activity of the whole plant extracts and isolation of active principles from A. paniculata were investigated. Dichloromethane (DCM) and methanol (MEOH) extracts of A. paniculata whole plant were screened for their antifungal potential using broth microdilution method in vitro against seven pathogenic fungal species responsible for skin infections. Active principles were detected through bioguided assays and isolated using chromatography techniques. Structures of compounds were elucidated through spectroscopy techniques and comparisons were made with previously reported data for similar compounds. DCM extract revealed lowest minimum inhibitory concentration (MIC) value (100 μg/mL) against Microsporum canis, Candida albicans, and Candida tropicalis, whereas MEOH extract revealed lowest MIC (150 µg/mL) against C. tropicalis and Aspergillus niger. DCM extract showed lowest minimum fungicidal concentration (MFC) value (250 µg/mL) against M. canis, C. albicans, C. tropicalis and A. niger, whereas MEOH extract showed lowest MFC (250 µg/mL) against Trichophyton mentagrophytes, Trichophyton rubrum, M. canis, C. albicans, C. tropicalis and A. niger. Bioassay guided isolation from DCM and MEOH extract afforded 3-O-β-d-glucosyl-14-deoxyandrographiside, 14-deoxyandrographolide, and 14-deoxy-11,12-didehydroandrographolide as antifungal compounds. The lowest MIC (50 µg/mL) and MFC (50 µg/mL) was exerted by 14-deoxyandrographolide on M. canis. This is first report on the isolation of antifungal substances through bioassay-guided assay from A. paniculata. Our finding justifies the use of A. paniculata in folk medicines for the treatment of fungal skin infections.

Polymorphism in Mitochondrial Group I Introns among Cryptococcus neoformans and Cryptococcus gattii Genotypes and Its Association with Drug Susceptibility.

PubMed

Gomes, Felipe E E S; Arantes, Thales D; Fernandes, José A L; Ferreira, Leonardo C; Romero, Héctor; Bosco, Sandra M G; Oliveira, Maria T B; Del Negro, Gilda M B; Theodoro, Raquel C

2018-01-01

Cryptococcosis, one of the most important systemic mycosis in the world, is caused by different genotypes of Cryptococcus neoformans and Cryptococcus gattii , which differ in their ecology, epidemiology, and antifungal susceptibility. Therefore, the search for new molecular markers for genotyping, pathogenicity and drug susceptibility is necessary. Group I introns fulfill the requisites for such task because (i) they are polymorphic sequences; (ii) their self-splicing is inhibited by some drugs; and (iii) their correct splicing under parasitic conditions is indispensable for pathogen survival. Here, we investigated the presence of group I introns in the mitochondrial LSU rRNA gene in 77 Cryptococcus isolates and its possible relation to drug susceptibility. Sequencing revealed two new introns in the LSU rRNA gene. All the introns showed high sequence similarity to other mitochondrial introns from distinct fungi, supporting the hypothesis of an ancient non-allelic invasion. Intron presence was statistically associated with those genotypes reported to be less pathogenic ( p < 0.001). Further virulence assays are needed to confirm this finding. In addition, in vitro antifungal tests indicated that the presence of LSU rRNA introns may influence the minimum inhibitory concentration (MIC) of amphotericin B and 5-fluorocytosine. These findings point to group I introns in the mitochondrial genome of Cryptococcus as potential molecular markers for antifungal resistance, as well as therapeutic targets.

Comparison study of broth macrodilution and microdilution antifungal susceptibility tests for the filamentous fungi.

PubMed

Pujol, I; Guarro, J; Llop, C; Soler, L; Fernández-Ballart, J

1996-09-01

An evaluation of broth dilution antifungal susceptibility tests was performed by determining both the micro- and macrodilution MICs of amphotericin B, fluconazole, ketoconazole, 5-fluorocytosine, miconazole, and itraconazole against representative species of opportunistic hyphomycetes (Fusarium spp. and Cladosporium [Cladophialophora] spp.) and ascomycetes (Chaetomium spp.). A total of 78 strains were tested, the majority of them twice and some three times on different days. Both methods were performed according to the recommendations of the National Committee for Clinical Laboratory Standards (Document M27-P), with the exception of the temperature of incubation, which was 25 degrees C in our case. A spectrophotometric method for inoculum preparation, RPMI 1640 medium buffered with morpholinepropanesulfonic acid (pH 7.0), and an additive drug dilution procedure were used. The MICs obtained by the two methods were read after 48, 72, and 96 h of incubation for Fusarium spp. and after 72, 96, and 120 h for the remaining isolates. The kappa test was used to calculate the degree of agreement. Considering the three fungal groups together, a good agreement between the results of both tests was observed with almost all the drugs at the different incubation times. There were no cases of poor agreement. The highest level (kappa index = 1) was observed with ketoconazole at the second-day reading. These results support the further evaluation of the broth microdilution test as an alternative to the reference broth macrodilution susceptibility test.

Comparison study of broth macrodilution and microdilution antifungal susceptibility tests for the filamentous fungi.

PubMed Central

Pujol, I; Guarro, J; Llop, C; Soler, L; Fernández-Ballart, J

1996-01-01

An evaluation of broth dilution antifungal susceptibility tests was performed by determining both the micro- and macrodilution MICs of amphotericin B, fluconazole, ketoconazole, 5-fluorocytosine, miconazole, and itraconazole against representative species of opportunistic hyphomycetes (Fusarium spp. and Cladosporium [Cladophialophora] spp.) and ascomycetes (Chaetomium spp.). A total of 78 strains were tested, the majority of them twice and some three times on different days. Both methods were performed according to the recommendations of the National Committee for Clinical Laboratory Standards (Document M27-P), with the exception of the temperature of incubation, which was 25 degrees C in our case. A spectrophotometric method for inoculum preparation, RPMI 1640 medium buffered with morpholinepropanesulfonic acid (pH 7.0), and an additive drug dilution procedure were used. The MICs obtained by the two methods were read after 48, 72, and 96 h of incubation for Fusarium spp. and after 72, 96, and 120 h for the remaining isolates. The kappa test was used to calculate the degree of agreement. Considering the three fungal groups together, a good agreement between the results of both tests was observed with almost all the drugs at the different incubation times. There were no cases of poor agreement. The highest level (kappa index = 1) was observed with ketoconazole at the second-day reading. These results support the further evaluation of the broth microdilution test as an alternative to the reference broth macrodilution susceptibility test. PMID:8878589

In Vitro antifungal activity of essential oils against Colletotrichum gloeosporioides

NASA Astrophysics Data System (ADS)

Yusoff, Nor Hanis Aifaa; Abdullah, Siti Aisyah; Othman, Zaulia; Zainal, Zamri

2018-04-01

The efficacy of Citrus hystrix, Azadirachta indica and Cymbopogon citratus essential oils were evaluated for controlling the growth of mycelia and spore germination of Colletotrichum gloeosporioides. In order to determine the best essential oil (EO) and suitable concentration of essential oil, in vitro experiment was conducted by preparing a pure culture of antrachnose on Potato Dextrose Agar containing EOs of C. hystrix, A. indica and C. citratus with different concentrations (0.2%, 0.6%, 1% and 1.4% (v/v)). The result shows that C. hystrix essential oil at a concentration of 1.4% (v/v) reduced of mycelia growth of C. gloeosporioides by 29.49%. A second experiment was conducted, but at higher concentration of each essential oils (1.8%, 2.2%, 2.6% and 2.8% (v/v)). Significant difference (p ≤ 0.05) inhibition of mycelia growth was obtained in all treatments except the control. The antifungal index values of essential oils were proportionally increased with concentration of essential oil applied in each treatment. It is concluded that essential oil from C. hystrix are efficient in inhibiting C. gloeosporioides.

Candida species diversity and antifungal susceptibility patterns in oral samples of HIV/AIDS patients in Baja California, Mexico.

PubMed

Clark-Ordóñez, Isadora; Callejas-Negrete, Olga A; Aréchiga-Carvajal, Elva T; Mouriño-Pérez, Rosa R

2017-04-01

Candidiasis is the most common opportunistic fungal infection in HIV patients. The aims of this study were to identify the prevalence of carriers of Candida, Candida species diversity, and in vitro susceptibility to antifungal drugs. In 297 HIV/AIDS patients in Baja California, Mexico, Candida strains were identified by molecular methods (PCR-RFLP) from isolates of oral rinses of patients in Tijuana, Mexicali, and Ensenada. 56.3% of patients were colonized or infected with Candida. In Tijuana, there was a significantly higher percentage of carriers (75.5%). Out of the 181 strains that were isolated, 71.8% were Candida albicans and 28.2% were non-albicans species. The most common non-albicans species was Candida tropicalis (12.2%), followed by Candida glabrata (8.3%), Candida parapsilosis (2.2%), Candida krusei (1.7%), and Candida guilliermondii (1.1%). Candida dubliniensis was not isolated. Two associated species were found in 11 patients. In Mexicali and Ensenada, there was a lower proportion of Candida carriers compared to other regions in Mexico and worldwide, however, in Tijuana, a border town with many peculiarities, a higher carrier rate was found. In this population, only a high viral load was associated with oral Candida carriers. Other factors such as gender, use of antiretroviral therapy, CD4+ T-lymphocyte levels, time since diagnosis, and alcohol/ tobacco consumption, were not associated with Candida carriers. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Heparin-benzyl alcohol enhancement of biofilms formation and antifungal susceptibility of vaginal Candida species isolated from pregnant and nonpregnant Saudi women

PubMed Central

Al-akeel, Raid A; El-kersh, Talat A; Al-Sheikh, Yazeed A; Al-Ahmadey, Ziab Zakey

2013-01-01

Biofilm formation by Candida species is a major contribute to their pathogenic potential.The aim of this study was to determine in vitro effects of EDTA, cycloheximide, and heparin-benzyl alcohol preservative on C. albicans (126) and non-albicans (31)vaginal yeast isolates biofilm formations and their susceptibility against three antifungal Etest strips. Results of the crystal violet-assay, indicated that biofilms formation were most commonly observed [100%] for C. kefyr, C. utilis, C. famata, and Rhodotorula mucilaginosa, followed by C. glabrata [70%], C. tropicalis [50%], C. albicans [29%], Saccharomyces cerevisiae [0.0%]. EDTA (0.3mg/ml) significantly inhibited biofilm formation in both C. albicans and non-albicans isolates (P=0.0001) presumably due to chelation of necessary metal cations for the process-completion. In contrast, heparin (-benzyl alcohol preservative) stimulated biofilm formation in all tested isolates, but not at significant level (P=0.567). Conversely, cycloheximide significantly (P=0.0001) inhibited biofilm formation in all C. albicans strains(126) and its effect was even 3 fold more pronounced than EDTA inhibition, probably due to its attenuation of proteins (enzymes) and/or complex molecules necessary for biofilm formation. Results also showed that all nonalbicans yeasts isolates were susceptible to 5-flucytosine (MIC50, 0.016 µg/ml; MIC90, 0.064 µg/ml), but 14% of C. albicans isolates were resistant (MIC50, 0.064 µg/ml; MIC90 >32 µg/ml). The MIC50 value of amphotricin B for all C. albicans and non-albicans isolates was at a narrow range of 0.023 µg /ml, and the MIC90 values were 0.047 µg/ml and 0.064 µg/ml respectively, thereby confirming its efficacy as a first line empiric- treatment of Candida spp infections. PMID:23750080

Study on chemical analysis, antioxidant and in vitro antifungal activities of essential oil from wild Vitex agnus-castus L. seeds growing in area of Argan Tree of Morocco against clinical strains of Candida responsible for nosocomial infections.

PubMed

Asdadi, A; Hamdouch, A; Oukacha, A; Moutaj, R; Gharby, S; Harhar, H; El Hadek, M; Chebli, B; Idrissi Hassani, L M

2015-12-01

To study the composition, the antioxidant activity and the in vitro antifungal action anti-Candida species of essential oils extracted from seeds of Vite xagnus-castus L. The essential oils were extracted using Clevenger-type apparatus and analyzed by gas chromatography/mass spectrometry (GC/MS). The antioxidant activity was analyzed using the DPPH free radical-scavenging method. Susceptibility tests for Candida albicans (12), C. dubliniensis (1), C. glabrata (3), C. krusei (3), C. parapsilosis (6), C. lusitaniae (1), C. famata (1) and C. tropicalis (3) were expressed as inhibition zone by the disc-diffusion method and as minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) by the broth macrodilution method, compared to amphotricin B and fluconazol as standard drugs. Major components were: 1,8-cineole (19.61%), sabinene (14.57%), α-pinene (9.76%), β-farnesene (6.04%), β-caryophyllene oxide (5.83%) and β-caryophyllene (5.02%). A low antioxidant activity was found (IC50=1.072mg/ml), but it can be exploited. V. agnus-castus seeds essential oils disosed a 35-58mm zone of inhibition (mean: 49mm) against all 30 isolates tested. In broth macrodilution method, all the tested Candida species were susceptible to the essential oils and this activity was concentration-dependent. MIC values varied from 0.13 to 2.13mg/ml V. agnus-castus seeds essential oils. Results of this study indicated that the oils of plant origin could be used as potential anti-Candida species causative agents of nosocomial infections. These oils exhibited a noticeable antifungal activity against the selected fungi. The natural antifungal substances are inexpensive and have fewer side effects, they may represent alternative therapies for candidiasis. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

In vitro and in vivo antifungal efficacy of plant based lawsone against Fusarium oxysporum species complex.

PubMed

Dananjaya, S H S; Udayangani, R M C; Shin, Sang Yeop; Edussuriya, M; Nikapitiya, Chamilani; Lee, Jehee; De Zoysa, Mahanama

2017-08-01

Fusarium oxysporum is an ascomycete facultative fungus which generally affects to plants. However, it is recently known as a serious emerging opportunistic pathogen of human and other animals. F. oxysporum shows broad resistance to commonly used antifungal agents and therefore development of alternative therapeutic agents is required. In this study, we investigated the antifungal efficacy of plant based natural lawsone against pathogenic F. oxysporum. Antifungal susceptibility test determined the concentration dependent growth inhibition of lawsone against F. oxysporum with minimum inhibitory concentration (MIC) at 100μg/mL. Ultra-structural analysis indicates the prominent damage on cell wall of the mycelium after lawsone treatment, and suggests that it could increase the membrane permeability and disintegration of cells leading to cellular death. Propidium iodide (PI) uptake assay results showed the higher level of cell death in lawsone treated F. oxysporum which further confirms the loss of plasma membrane integrity. Also, detection of reactive oxygen species (ROS) using DCFH-DA has clearly indicated that lawsone (100μg/mL) can induce the ROS level in the filaments of F. oxysporum. MTT assay results showed the loss of viability and germination capacity of F. oxysporum spores by lawsone in concentration dependent manner. Moreover, lawsone treatment induced the mRNA expression of two autophagy related genes (ATG1 and ATG8) indicating that lawsone may activate the autophagy related pathways in F. oxysporum due to the oxidative stress generated by ROS. F. oxysporum infected zebrafish has recovered after lawsone therapy as a topical treatment suggesting that lawsone is a potential natural antifusariosis agent. Copyright © 2017 Elsevier GmbH. All rights reserved.

Susceptibility to antifungal agents and enzymatic activity of Candida haemulonii and Cutaneotrichosporon dermatis isolated from soft corals on the Brazilian reefs.

PubMed

Pagani, Danielle M; Heidrich, Daiane; Paulino, Gustavo V B; de Oliveira Alves, Karine; Dalbem, Paula T; de Oliveira, Caroline F; Andrade, Zélia M M; Silva, Carolini; Correia, Monica D; Scroferneker, Maria Lúcia; Valente, Patricia; Landell, Melissa Fontes

2016-12-01

Candida is a common fungus with the capacity to cause infections in humans. However, most studies have concentrated on clinical isolates and little is known about the identity, ecology and drug resistance of free living species/strains. Here, we isolate eight strains of Candida haemulonii and four strains of Cutaneotrichosporon dermatis from three marine cnidarian zoanthids species (Palythoa caribaeorum, Palythoa variabilis and Zoanthus sociatus) collected from Brazilian coral reefs. Strains were identified by sequencing of the D1/D2 domain LSU rDNA and ITS region. We tested these environmental isolates for their capacity to grow in media with increasing concentration of NaCl, capacity to grow in different temperatures, enzymatic activity and antifungal susceptibility. For C. haemulonii, all strains strongly produced gelatinase, esterase and albuminase and were either able to express lipase, phospholipase and keratinase, but not express urease and DNase. The strains were able to grow at 37 °C, but not at 39 °C, and except for LMS 40, all of them could grow in a 10 % NaCl medium. All isolates were resistant to all antifungals tested, with exception for ketoconazole and tioconazole (MIC = 2 µg/mL). For C. dermatis, all strains could grow at 39 °C and could not express phospholipase, keratinase or gelatinase. However, all were capable of expressing urease, lipase and esterase. Three out of four strains could grow in a 10 % NaCl medium, but none grew in a 30 % NaCl medium. The strains showed high values of minimal inhibitory concentration. LMPV 90 was resistant to tioconazole, terbinafine, fluconazole and posaconazole, and LMS 38 was resistant to all antifungal agents tested. We discuss the characterization of C. haemulonii and C. dermatis as a possible emerging pathogen due to its animal-related enzymatic arsenal and antifungal resistance.

Functionalised isocoumarins as antifungal compounds: Synthesis and biological studies.

PubMed

Simic, Milena; Paunovic, Nikola; Boric, Ivan; Randjelovic, Jelena; Vojnovic, Sandra; Nikodinovic-Runic, Jasmina; Pekmezovic, Marina; Savic, Vladimir

2016-01-01

A series of novel 3-substituted isocoumarins was prepared via Pd-catalysed coupling processes and screened in vitro for antifungal activity against Candida species. The study revealed antifungal potential of isocoumarins possessing the azole substituents, which, in some cases, showed biological properties equal to those of clinically used voriconazole. Selected compounds were also screened against voriconazole resistant Candida krusei 6258 and a clinical isolate Candida parapsilosis CA-27. Although the activity against these targets needs to be improved further, the results emphasise additional potential of this new class of antifungal compounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

Species Distribution and In Vitro Azole Susceptibility of Aspergillus Section Nigri Isolates from Clinical and Environmental Settings.

PubMed

Iatta, Roberta; Nuccio, Federica; Immediato, Davide; Mosca, Adriana; De Carlo, Carmela; Miragliotta, Giuseppe; Parisi, Antonio; Crescenzo, Giuseppe; Otranto, Domenico; Cafarchia, Claudia

2016-09-01

Aspergillus section Nigri includes species of interest for animal and human health, although studies on species distribution are limited to human cases. Data on the antifungal susceptibilities and the molecular mechanism of triazole resistance in strains belonging to this section are scant. Forty-two black Aspergillus strains from human patients (16 isolates), animals (14 isolates), and the environment (12 isolates) were molecularly characterized and their in vitro triazole susceptibilities investigated. Aspergillus tubingensis was isolated from humans, animals, and environmental settings, whereas Aspergillus awamori and Aspergillus niger were isolated exclusively from humans. Phylogenetic analyses of β-tubulin and calmodulin gene sequences were concordant in differentiating A. tubingensis from A. awamori and A. niger Voriconazole and posaconazole (PSZ) were the most active triazoles. One A. tubingensis strain was resistant to itraconazole and PSZ and one A. niger strain to PSZ. Sequence analysis of the cyp51A gene revealed different sequence types within a species, and A. tubingensis strains were also phylogenetically distinct from A. awamori/A. niger strains according to the strain origin and susceptibility profile. Genetic analysis of the cyp51A sequences suggests that two nonsynonymous mutations resulting in amino acid substitutions in the CYP51A protein (changes of L to R at position 21 [L21R] and of Q to R at position 228 [Q228R]) might be involved in azole resistance. Though azole resistance in black Aspergillus isolates from animals and rural environments does not represent a threat to public health in Southern Italy, the use of triazoles in the clinical setting needs to better monitored. The cyp51A sequence is useful for the molecular identification of black Aspergillus, and point mutations in protein sequences could be responsible for azole resistance phenomena. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Species Distribution and In Vitro Azole Susceptibility of Aspergillus Section Nigri Isolates from Clinical and Environmental Settings

PubMed Central

Iatta, Roberta; Nuccio, Federica; Immediato, Davide; Mosca, Adriana; De Carlo, Carmela; Miragliotta, Giuseppe; Parisi, Antonio; Crescenzo, Giuseppe; Otranto, Domenico

2016-01-01

Aspergillus section Nigri includes species of interest for animal and human health, although studies on species distribution are limited to human cases. Data on the antifungal susceptibilities and the molecular mechanism of triazole resistance in strains belonging to this section are scant. Forty-two black Aspergillus strains from human patients (16 isolates), animals (14 isolates), and the environment (12 isolates) were molecularly characterized and their in vitro triazole susceptibilities investigated. Aspergillus tubingensis was isolated from humans, animals, and environmental settings, whereas Aspergillus awamori and Aspergillus niger were isolated exclusively from humans. Phylogenetic analyses of β-tubulin and calmodulin gene sequences were concordant in differentiating A. tubingensis from A. awamori and A. niger. Voriconazole and posaconazole (PSZ) were the most active triazoles. One A. tubingensis strain was resistant to itraconazole and PSZ and one A. niger strain to PSZ. Sequence analysis of the cyp51A gene revealed different sequence types within a species, and A. tubingensis strains were also phylogenetically distinct from A. awamori/A. niger strains according to the strain origin and susceptibility profile. Genetic analysis of the cyp51A sequences suggests that two nonsynonymous mutations resulting in amino acid substitutions in the CYP51A protein (changes of L to R at position 21 [L21R] and of Q to R at position 228 [Q228R]) might be involved in azole resistance. Though azole resistance in black Aspergillus isolates from animals and rural environments does not represent a threat to public health in Southern Italy, the use of triazoles in the clinical setting needs to better monitored. The cyp51A sequence is useful for the molecular identification of black Aspergillus, and point mutations in protein sequences could be responsible for azole resistance phenomena. PMID:27413191

Antifungal susceptibilities of Cryptococcus neoformans.

PubMed

Archibald, Lennox K; Tuohy, Marion J; Wilson, Deborah A; Nwanyanwu, Okey; Kazembe, Peter N; Tansuphasawadikul, Somsit; Eampokalap, Boonchuay; Chaovavanich, Achara; Reller, L Barth; Jarvis, William R; Hall, Gerri S; Procop, Gary W

2004-01-01

Susceptibility profiles of medically important fungi in less-developed countries remain uncharacterized. We measured the MICs of amphotericin B, 5-flucytosine, fluconazole, itraconazole, and ketoconazole for Cryptococcus neoformans clinical isolates from Thailand, Malawi, and the United States and found no evidence of resistance or MIC profile differences among the countries.

Evaluation of antifungal activity of standardized extract of Salvia rhytidea Benth. (Lamiaceae) against various Candida isolates.

PubMed

Salari, S; Bakhshi, T; Sharififar, F; Naseri, A; Ghasemi Nejad Almani, P

2016-12-01

Salvia species have long been described in traditional medicine for various indications. Owing to the widespread use of this genus by ethnic populations, especially for various infections ranging from skin disease to gastrointestinal disorders, we were encouraged to determine whether Salvia rhytidea could be effective against fungal infections. Given the increased incidence of candidiasis in the past decade, limits on the use of antifungal drugs, emergence of azole-resistant Candida species and increased incidence of treatment failures, it is necessary to identify a novel agent with antifungal properties. Aim of the study was to evaluate the antifungal properties of S. rhytidea against various Candida isolates. In this study, at first rosmarinic acid content of plant extract was determined. A total of 96 Candida isolates were tested, including the following species: Candida albicans (n=42), Candida glabrata (n=16), Candida tropicalis (n=11), Candida krusei (n=9), Candida parapsilosis (n=9), Candida lusitaniae (n=7) and Candida guilliermondii (n=2). The in vitro antifungal activity of methanolic extracts of S. rhytidea Benth. was evaluated against Candida isolates and compared with that of the standard antifungal drug nystatin by using a broth microdilution method, according to CLSI. Phytochemical screening results showed that the methanolic extract of S. rhytidea Benth. was rich in flavonoids and tannins. The minimal inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of S. rhytidea Benth. ranged from 3.125 to>100μg/ml and 6.25 to>100μg/ml respectively. The growth inhibition value displayed that C. tropicalis, C. krusei and C. albicans isolates were most susceptible to S. rhytidea. Findings show that S. rhytidea possesses an antifungal effect against Candida isolates. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Enzymatic Activity and Susceptibility to Antifungal Agents of Brazilian Environmental Isolates of Hortaea werneckii.

PubMed

Formoso, Andrea; Heidrich, Daiane; Felix, Ciro Ramón; Tenório, Anne Carolyne; Leite, Belize R; Pagani, Danielle M; Ortiz-Monsalve, Santiago; Ramírez-Castrillón, Mauricio; Landell, Melissa Fontes; Scroferneker, Maria L; Valente, Patricia

2015-12-01

Four strains of Hortaea werneckii were isolated from different substrates in Brazil (a salt marsh macrophyte, a bromeliad and a marine zoanthid) and had their identification confirmed by sequencing of the 26S rDNA D1/D2 domain or ITS region. Most of the strains were able to express amylase, lipase, esterase, pectinase and/or cellulase, enzymes that recognize components of plant cells as substrates, but did not express albuminase, keratinase, phospholipase and DNAse, whose substrates are animal-related. Urease production was positive for all isolates, while caseinase, gelatinase and laccase production were variable among the strains. All the strains grew in media containing up to 30% NaCl. We propose that the primary substrate associated with H. werneckii is plant-related, in special in saline environments, where the fungus may live as a saprophyte and decomposer. Infection of animal-associated substrates would be secondary, with the fungus acting as an opportunistic animal pathogen. All strains were resistant to fluconazole and presented high MIC for amphotericin B, while they were susceptible to all the other antifungal agents tested.

Antifungal Susceptibilities of Cryptococcus neoformans

PubMed Central

Tuohy, Marion J.; Wilson, Deborah A.; Nwanyanwu, Okey; Kazembe, Peter N.; Tansuphasawadikul, Somsit; Eampokalap, Boonchuay; Chaovavanich, Achara; Reller, L.Barth; Jarvis, William R.; Hall, Gerri S.; Procop, Gary W.

2004-01-01

Susceptibility profiles of medically important fungi in less-developed countries remain uncharacterized. We measured the MICs of amphotericin B, 5-flucytosine, fluconazole, itraconazole, and ketoconazole for Cryptococcus neoformans clinical isolates from Thailand, Malawi, and the United States and found no evidence of resistance or MIC profile differences among the countries. PMID:15078612

[In vitro antimicrobial, antiadherent and antifungal activity of Brazilian medicinal plants on oral biofilm microorganisms and strains of the genus Candida].

PubMed

Alves, Pollianna Muniz; Queiroz, Lélia Maria Guedes; Pereira, Jozinete Vieira; Pereira, Maria do Socorro Vieira

2009-01-01

The antimicrobial, antifungal and antiadherent activity of aroeira-do-sertão, mallow and guava tree on oral biofilm microorganisms and oral candidiasis was evaluated in vitro. The extracts were shown to be effective in inhibiting the growth of bacteria of the oral biofilm and fungi of oral candidiasis, thus suggesting that these extracts can be used as alternative means of dental therapy.

Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs.

PubMed

Fernandes, Chantal; Prados-Rosales, Rafael; Silva, Branca M A; Nakouzi-Naranjo, Antonio; Zuzarte, Mónica; Chatterjee, Subhasish; Stark, Ruth E; Casadevall, Arturo; Gonçalves, Teresa

2015-12-28

The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs

PubMed Central

Fernandes, Chantal; Prados-Rosales, Rafael; Silva, Branca M. A.; Nakouzi-Naranjo, Antonio; Zuzarte, Mónica; Chatterjee, Subhasish; Stark, Ruth E.; Casadevall, Arturo

2015-01-01

The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis. PMID:26711773

Atmospheric pressure cold plasma as an antifungal therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun Peng; Wu Haiyan; Sun Yi

2011-01-10

A microhollow cathode based, direct-current, atmospheric pressure, He/O{sub 2} (2%) cold plasma microjet was used to inactive antifungal resistants Candida albicans, Candida krusei, and Candida glabrata in air and in water. Effective inactivation (>90%) was achieved in 10 min in air and 1 min in water. Antifungal susceptibility tests showed drastic reduction of the minimum inhibitory concentration after plasma treatment. The inactivation was attributed to the reactive oxygen species generated in plasma or in water. Hydroxyl and singlet molecular oxygen radicals were detected in plasma-water system by electron spin resonance spectroscopy. This approach proposed a promising clinical dermatology therapy.

In vitro investigation of antifungal activity of allicin alone and in combination with azoles against Candida species.

PubMed

Khodavandi, Alireza; Alizadeh, Fahimeh; Aala, Farzad; Sekawi, Zamberi; Chong, Pei Pei

2010-04-01

Candidiasis is a term describing infections by yeasts from the genus Candida, and the type of infection encompassed by candidiasis ranges from superficial to systemic. Treatment of such infections often requires antifungals such as the azoles, but increased use of these drugs has led to selection of yeasts with increased resistance to these drugs. In this study, we used allicin, an allyl sulfur derivative of garlic, to demonstrate both its intrinsic antifungal activity and its synergy with the azoles, in the treatment of these yeasts in vitro. In this study, the MIC(50) and MIC(90) of allicin alone against six Candida spp. ranged from 0.05 to 25 microg/ml. However, when allicin was used in combination with fluconazole or ketoconazole, the MICs were decreased in some isolates. Our results demonstrated the existing synergistic effect between allicin and azoles in some of the Candida spp. such as C. albicans, C. glabrata and C. tropicalis, but synergy was not demonstrated in the majority of Candida spp. tested. Nonetheless, In vivo testing needs to be performed to support these findings.

Natural Killer Cells in Antifungal Immunity.

PubMed

Schmidt, Stanislaw; Tramsen, Lars; Lehrnbecher, Thomas

2017-01-01

Invasive fungal infections are still an important cause of morbidity and mortality in immunocompromised patients such as patients suffering from hematological malignancies or patients undergoing hematopoietic stem cell transplantion. In addition, other populations such as human immunodeficiency virus-patients are at higher risk for invasive fungal infection. Despite the availability of new antifungal compounds and better supportive care measures, the fatality rate of invasive fungal infection remained unacceptably high. It is therefore of major interest to improve our understanding of the host-pathogen interaction to develop new therapeutic approaches such as adoptive immunotherapy. As experimental methodologies have improved and we now better understand the complex network of the immune system, the insight in the interaction of the host with the fungus has significantly increased. It has become clear that host resistance to fungal infections is not only associated with strong innate immunity but that adaptive immunity (e.g., T cells) also plays an important role. The antifungal activity of natural killer (NK) cells has been underestimated for a long time. In vitro studies demonstrated that NK cells from murine and human origin are able to attack fungi of different genera and species. NK cells exhibit not only a direct antifungal activity via cytotoxic molecules but also an indirect antifungal activity via cytokines. However, it has been show that fungi exert immunosuppressive effects on NK cells. Whereas clinical data are scarce, animal models have clearly demonstrated that NK cells play an important role in the host response against invasive fungal infections. In this review, we summarize clinical data as well as results from in vitro and animal studies on the impact of NK cells on fungal pathogens.

Isobolographic Analysis of Pharmacodynamic Interactions between Antifungal Agents and Ciprofloxacin against Candida albicans and Aspergillus fumigatus▿

PubMed Central

Stergiopoulou, Theodouli; Meletiadis, Joseph; Sein, Tin; Papaioannidou, Paraskevi; Tsiouris, Ioannis; Roilides, Emmanuel; Walsh, Thomas J.

2008-01-01

Patients suffering from invasive mycoses often receive concomitant antifungal therapy and antibacterial agents. Assessment of pharmacodynamic interactions between antifungal and antibacterial agents is complicated by the absence of a common antifungal end point for both agents. Ciprofloxacin has no intrinsic antifungal activity but may interact with antifungal agents, since it inhibits DNA gyrase (topoisomerase II), which is abundant in fungi. We therefore employed isobolographic analysis adapted to incorporate a nonactive agent in order to analyze the potential in vitro interaction between the fluoroquinolone ciprofloxacin and several representative antifungal agents against Candida albicans and Aspergillus fumigatus strains by using a microdilution checkerboard technique. In agreement with earlier in vitro studies, conventional fractional inhibitory concentration index analysis was unable to detect interactions between ciprofloxacin and antifungal agents. However, isobolographic analysis revealed significant pharmacodynamic interactions between antifungal agents and ciprofloxacin against C. albicans and A. fumigatus strains. Amphotericin B demonstrated concentration-dependent interactions for both species, with synergy (interaction indices, 0.14 to 0.81) observed at ciprofloxacin concentrations of <10.64 μg/ml. Synergy (interaction indices, 0.10 to 0.86) was also found for voriconazole and caspofungin against A. fumigatus. Isobolographic analysis may help to elucidate the pharmacodynamic interactions between antifungal and non-antifungal agents and to develop better management strategies against invasive candidiasis and aspergillosis. PMID:18299413

Antifungal drug susceptibility and phylogenetic diversity among Cryptococcus isolates from dogs and cats in North America.

PubMed

Singer, Lisa M; Meyer, Wieland; Firacative, Carolina; Thompson, George R; Samitz, Eileen; Sykes, Jane E

2014-06-01

Molecular types of the Cryptococcus neoformans/Cryptococcus gattii species complex that infect dogs and cats differ regionally and with host species. Antifungal drug susceptibility can vary with molecular type, but the susceptibility of Cryptococcus isolates from dogs and cats is largely unknown. Cryptococcus isolates from 15 dogs and 27 cats were typed using URA5 restriction fragment length polymorphism analysis (RFLP), PCR fingerprinting, and multilocus sequence typing (MLST). Susceptibility was determined using a microdilution assay (Sensititre YeastOne; Trek Diagnostic Systems). MICs were compared among groups. The 42 isolates studied comprised molecular types VGI (7%), VGIIa (7%), VGIIb (5%), VGIIc (5%), VGIII (38%), VGIV (2%), VNI (33%), and VNII (2%), as determined by URA5 RFLP. The VGIV isolate was more closely related to VGIII according to MLST. All VGIII isolates were from cats. All sequence types identified from veterinary isolates clustered with isolates from humans. VGIII isolates showed considerable genetic diversity compared with other Cryptococcus molecular types and could be divided into two major subgroups. Compared with C. neoformans MICs, C. gattii MICs were lower for flucytosine, and VGIII MICs were lower for flucytosine and itraconazole. For all drugs except itraconazole, C. gattii isolates exhibited a wider range of MICs than C. neoformans. MICs varied with Cryptococcus species and molecular type in dogs and cats, and MICs of VGIII isolates were most variable and may reflect phylogenetic diversity in this group. Because sequence types of dogs and cats reflect those infecting humans, these observations may also have implications for treatment of human cryptococcosis. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

In Vitro Interactions between Non-Steroidal Anti-Inflammatory Drugs and Antifungal Agents against Planktonic and Biofilm Forms of Trichosporon asahii

PubMed Central

Cong, Lin; Lu, Xuelian

2016-01-01

Increasing drug resistance has brought enormous challenges to the management of Trichosporon spp. infections. The in vitro antifungal activities of non-steroidal anti-inflammatory drugs (NSAIDs) against Candida spp. and Cryptococcus spp. were recently discovered. In the present study, the in vitro interactions between three NSAIDs (aspirin, ibuprofen and diclofenac sodium) and commonly used antifungal agents (fluconazole, itraconazole, voriconazole, caspofungin and amphotericin B) against planktonic and biofilm cells of T. asahii were evaluated using the checkerboard microdilution method. The spectrophotometric method and the XTT reduction assay were used to generate data on biofilm cells. The fractional inhibitory concentration index (FICI) and the ΔE model were compared to interpret drug interactions. Using the FICI, the highest percentages of synergistic effects against planktonic cells (86.67%) and biofilm cells (73.33%) were found for amphotericin B/ibuprofen, and caspofungin/ibuprofen showed appreciable percentages (73.33% for planktonic form and 60.00% for biofilm) as well. We did not observe antagonism. The ΔE model gave consistent results with FICI (86.67%). Our findings suggest that amphotericin B/ibuprofen and caspofungin/ibuprofen combinations have potential effects against T. asahii. Further in vivo and animal studies to investigate associated mechanisms need to be conducted. PMID:27275608

In vitro antifungal activity of hydroxychavicol isolated from Piper betle L.

PubMed

Ali, Intzar; Khan, Farrah G; Suri, Krishan A; Gupta, Bishan D; Satti, Naresh K; Dutt, Prabhu; Afrin, Farhat; Qazi, Ghulam N; Khan, Inshad A

2010-02-03

Hydroxychavicol, isolated from the chloroform extraction of the aqueous leaf extract of Piper betle L., (Piperaceae) was investigated for its antifungal activity against 124 strains of selected fungi. The leaves of this plant have been long in use tropical countries for the preparation of traditional herbal remedies. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of hydroxychavicol were determined by using broth microdilution method following CLSI guidelines. Time kill curve studies, post-antifungal effects and mutation prevention concentrations were determined against Candida species and Aspergillus species "respectively". Hydroxychavicol was also tested for its potential to inhibit and reduce the formation of Candida albicans biofilms. The membrane permeability was measured by the uptake of propidium iodide. Hydroxychavicol exhibited inhibitory effect on fungal species of clinical significance, with the MICs ranging from 15.62 to 500 microg/ml for yeasts, 125 to 500 microg/ml for Aspergillus species, and 7.81 to 62.5 microg/ml for dermatophytes where as the MFCs were found to be similar or two fold greater than the MICs. There was concentration-dependent killing of Candida albicans and Candida glabrata up to 8 x MIC. Hydroxychavicol also exhibited an extended post antifungal effect of 6.25 to 8.70 h at 4 x MIC for Candida species and suppressed the emergence of mutants of the fungal species tested at 2 x to 8 x MIC concentration. Furthermore, it also inhibited the growth of biofilm generated by C. albicans and reduced the preformed biofilms. There was increased uptake of propidium iodide by C. albicans cells when exposed to hydroxychavicol thus indicating that the membrane disruption could be the probable mode of action of hydroxychavicol. The antifungal activity exhibited by this compound warrants its use as an antifungal agent particularly for treating topical infections, as well as gargle mouthwash against oral Candida

Antifungal potential of marine natural products.

PubMed

El-Hossary, Ebaa M; Cheng, Cheng; Hamed, Mostafa M; El-Sayed Hamed, Ashraf Nageeb; Ohlsen, Knut; Hentschel, Ute; Abdelmohsen, Usama Ramadan

2017-01-27

Fungal diseases represent an increasing threat to human health worldwide which in some cases might be associated with substantial morbidity and mortality. However, only few antifungal drugs are currently available for the treatment of life-threatening fungal infections. Furthermore, plant diseases caused by fungal pathogens represent a worldwide economic problem for the agriculture industry. The marine environment continues to provide structurally diverse and biologically active secondary metabolites, several of which have inspired the development of new classes of therapeutic agents. Among these secondary metabolites, several compounds with noteworthy antifungal activities have been isolated from marine microorganisms, invertebrates, and algae. During the last fifteen years, around 65% of marine natural products possessing antifungal activities have been isolated from sponges and bacteria. This review gives an overview of natural products from diverse marine organisms that have shown in vitro and/or in vivo potential as antifungal agents, with their mechanism of action whenever applicable. The natural products literature is covered from January 2000 until June 2015, and we are reporting the chemical structures together with their biological activities, as well as the isolation source. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Orbital abscess bacterial isolates and in vitro antimicrobial susceptibility patterns in dogs and cats.

PubMed

Wang, Annie L; Ledbetter, Eric C; Kern, Thomas J

2009-01-01

To determine bacterial populations, in vitro antimicrobial susceptibility patterns, and sources of microorganisms for dogs and cats with orbital abscess. In total, 34 dogs and 7 cats with orbital abscess participated in the study. Medical records of dogs and cats with a clinical diagnosis of orbital abscess, confirmed by cytologic or histopathologic evaluation of orbital specimens, were reviewed from the years 1990 to 2007. Animal signalment, presumptive source of microorganisms and mechanism of orbital introduction, bacterial isolates, and aerobic bacterial in vitro antimicrobial susceptibility test results were recorded. Percentages of susceptible aerobic bacterial isolates were compared among antimicrobials. Twenty dogs and five cats had positive culture results. The most frequent bacterial genera isolated from dogs were Staphylococcus, Escherichia, Bacteroides, Clostridium and Pasteurella. The most frequent bacterial genera isolated from cats were Pasteurella and Bacteroides. Aerobic bacterial isolates from dogs had the highest percentage of susceptibility to amikacin, ceftiofur, gentamicin, imipenem, ticarcillin and trimethoprim-sulfamethoxazole. Aerobic bacterial isolates from dogs had the lowest percentage of susceptibility to ampicillin, clindamycin, erythromycin and penicillin. Antimicrobial resistance was uncommon among feline aerobic bacterial isolates. The most commonly identified routes of orbital bacteria introduction were extension from adjacent anatomical structures, penetrating exogenous trauma, and foreign bodies. Mixed aerobic and anaerobic bacterial infections of the orbit occur commonly in dogs and cats. On the basis of aerobic and anaerobic bacterial isolates and in vitro susceptibility testing of aerobic bacterial isolates, cephalosporins, extended-spectrum penicillins, potentiated-penicillins and carbapenems are recommended for initial antimicrobial therapy of orbital abscess in dogs and cats.

Susceptibility and molecular characterization of Candida species from patients with vulvovaginitis.

PubMed

Fornari, Gheniffer; Vicente, Vania Aparecida; Gomes, Renata Rodrigues; Muro, Marisol Dominguez; Pinheiro, Rosangela Lameira; Ferrari, Carolina; Herkert, Patricia Fernanda; Takimura, Marcos; Carvalho, Newton Sérgio de; Queiroz-Telles, Flavio

2016-01-01

Vulvovaginal candidiasis affects women of reproductive age, which represents approximately 15-25% of vaginitis cases. The present study aimed to isolate and characterize yeast from the patients irrespective of the presentation of clinical symptoms. The isolates were subjected to in vitro susceptibility profile and characterization by molecular markers, which intended to assess the distribution of species. A total of 40 isolates were obtained and identified through the CHROMagar, API20aux and by ITS and D1/D2 regions sequencing of DNAr gene. Candida albicans strains were genotyped by the ABC system and the isolates were divided into two genotypic groups. The identity of the C. albicans, C. glabrata, C. guilliermondii, C. kefyr and Saccharomyces cerevisiae isolates was confirmed by the multilocus analysis. The strains of Candida, isolated from patients with complications, were found to be resistant to nystatin but sensitive to fluconazole, amphotericin B and ketoconazole, as observed by in vitro sensitivity profile. The isolates from asymptomatic patients, i.e., the colonized group, showed a dose-dependent sensitivity to the anti-fungal agents, fluconazole and amphotericin B. However, the isolates of C. albicans that belong to distinct genotypic groups showed the same in vitro susceptibility profile. Copyright © 2016. Published by Elsevier Editora Ltda.

Antimicrobial Susceptibility of Tinea Capitis in Children from Egypt

PubMed Central

Doss, Reham William; El-Rifaie, Abdel-Aziz; Radi, Nagla; El-Sherif, Aya Yehia

2018-01-01

Background: Dermatophytic fungi of genera Trichophyton and Microsporum are the most important fungal species causing tinea capitis. Choice of treatment for tinea capitis is determined by the species of fungus. Aim: The aim of the study was to investigate the most prevalent fungal species causing tinea capitis in children from Egypt and the most useful antifungal agent for treatment. Patients and Methods: A total of 100 patients diagnosed clinically with tinea capitis were included in the study. Samples were collected and sent to the microbiology and immunology laboratory for sample processing and fungal identification by routine laboratory techniques. A study of antifungal susceptibility to chosen antifungal medications (fluconazole, ketoconazole, clotrimazole, miconazole, amphotericin, caspofungin, itraconazole, terbinafine, and griseofulvin) was done by minimum inhibitory concentration technique. Results: Our analysis revealed that Microsporum canis is the most commonly isolated strain. Amphotericin was the most effective antifungal agent followed by terbinafine. The most sensitive strain to fluconazole and griseofulvin is Microsporum gypseum, while Microsporum audouinii was mostly responsive to terbinafine. Conclusion: Identification and evaluation of the antifungal susceptibility of the pathogenic species in a certain geographic region is important to achieve a good clinical response. PMID:29692458

Antimicrobial Susceptibility of Tinea Capitis in Children from Egypt.

PubMed

Doss, Reham William; El-Rifaie, Abdel-Aziz; Radi, Nagla; El-Sherif, Aya Yehia

2018-01-01

Dermatophytic fungi of genera Trichophyton and Microsporum are the most important fungal species causing tinea capitis. Choice of treatment for tinea capitis is determined by the species of fungus. The aim of the study was to investigate the most prevalent fungal species causing tinea capitis in children from Egypt and the most useful antifungal agent for treatment. A total of 100 patients diagnosed clinically with tinea capitis were included in the study. Samples were collected and sent to the microbiology and immunology laboratory for sample processing and fungal identification by routine laboratory techniques. A study of antifungal susceptibility to chosen antifungal medications (fluconazole, ketoconazole, clotrimazole, miconazole, amphotericin, caspofungin, itraconazole, terbinafine, and griseofulvin) was done by minimum inhibitory concentration technique. Our analysis revealed that Microsporum canis is the most commonly isolated strain. Amphotericin was the most effective antifungal agent followed by terbinafine. The most sensitive strain to fluconazole and griseofulvin is Microsporum gypseum , while Microsporum audouinii was mostly responsive to terbinafine. Identification and evaluation of the antifungal susceptibility of the pathogenic species in a certain geographic region is important to achieve a good clinical response.

Antifungal prophylaxis during neutropenia and immunodeficiency.

PubMed Central

Lortholary, O; Dupont, B

1997-01-01

Fungal infections represent a major source of morbidity and mortality in patients with almost all types of immunodeficiencies. These infections may be nosocomial (aspergillosis) or community acquired (cryptococcosis), or both (candidiasis). Endemic mycoses such as histoplasmosis, coccidioidomycosis, and penicilliosis may infect many immunocompromised hosts in some geographic areas and thereby create major public health problems. With the wide availability of oral azoles, antifungal prophylactic strategies have been extensively developed. However, only a few well-designed studies involving strict criteria have been performed, mostly in patients with hematological malignancies or AIDS. In these situations, the best dose and duration of administration of the antifungal drug often remain to be determined. In high-risk neutropenic or bone marrow transplant patients, fluconazole is effective for the prevention of superficial and/or systemic candidal infections but is not always able to prolong overall survival and potentially selects less susceptible or resistant Candida spp. Primary prophylaxis against aspergillosis remains investigative. At present, no standard general recommendation for primary antifungal prophylaxis can be proposed for AIDS patients or transplant recipients. However, for persistently immunocompromised patients who previously experienced a noncandidal systemic fungal infection, prolonged suppressive antifungal therapy is often indicated to prevent a relapse. Better strategies for controlling immune deficiencies should also help to avoid some potentially life-threatening deep mycoses. When prescribing antifungal prophylaxis, physicians should be aware of the potential emergence of resistant strains, drug-drug interactions, and the cost. Well-designed, randomized, multicenter clinical trials in high-risk immunocompromised hosts are urgently needed to better define how to prevent severe invasive mycoses. PMID:9227863

In vitro combination of antifungal agents against Malassezia pachydermatis.

PubMed

Schlemmer, Karine B; de Jesus, Francielli P K; Loreto, Erico S; Farias, Julia B; Alves, Sydney H; Ferreiro, Laerte; Santurio, Janio M

2018-06-19

The yeast Malassezia pachydermatis is a common commensal and occasional opportunistic pathogen of theskin microbiota of animals and humans. In this study, the susceptibility of M. pachydermatis isolates to fluconazole (FLC), itraconazole (ITZ), ketoconazole (KTZ), clotrimazole (CLZ), and miconazole (MCZ) alone and in combination with terbinafine (TRB), nystatin (NYS), and caspofungin (CSP) was evaluated in vitro based on the M27-A3 technique and the checkerboard microdilution method using Sabouraud dextrose broth with 1% tween 80 (SDB). Based on the mean FICI values, the main synergies observed were combinations of ITZ+CSP and CLZ+CSP (55.17%). The most significant combinations deserve in vivo evaluations because might provide effective alternative treatments against M. pachydermatis due to their synergistic interactions.

In-vitro susceptibility of 400 isolates of Neisseria gonorrhoeae in Vancouver, 1982-84.

PubMed Central

Bowie, W R; Shaw, C E; Chan, D G; Jones, H D; Black, W A

1986-01-01

Consecutive isolates of Neisseria gonorrhoeae obtained at a sexually transmitted disease clinic in Vancouver between June 1982 and June 1984 were tested for in-vitro susceptibility to eight antimicrobial agents. Of the 400 isolates 6 (1.5%) were penicillinase-producing N. gonorrhoeae, and for 25 (6.2%) the minimum inhibitory concentrations (MICs) of penicillin were 1.0 to 4.0 micrograms/ml. Ceftriaxone sodium was the most active agent. The MICs were higher than those reported in a Canadian study in 1973-74, except for tetracycline hydrochloride. The patterns of susceptibility of the isolates to one antimicrobial agent correlated significantly with those to each other agent, although the relation was weakest for trimethoprim-sulfamethoxazole and spectinomycin. The results reinforce the need to evaluate local in-vitro susceptibility patterns, especially since the proportion of isolates with relative and absolute resistance to penicillin is increasing. PMID:3091234

Characterization of Antifungal Activity and Nail Penetration of ME1111, a New Antifungal Agent for Topical Treatment of Onychomycosis

PubMed Central

Takei-Masuda, Naomi; Kubota, Natsuki; Takahata, Sho; Ohyama, Makoto; Kaneda, Kaori; Iida, Maiko; Maebashi, Kazunori

2015-01-01

Fungal nail infection (onychomycosis) is a prevalent disease in many areas of the world, with a high incidence approaching 23%. Available antifungals to treat the disease suffer from a number of disadvantages, necessitating the discovery of new efficacious and safe antifungals. Here, we evaluate the in vitro antifungal activity and nail penetration ability of ME1111, a novel antifungal agent, along with comparator drugs, including ciclopirox, amorolfine, terbinafine, and itraconazole. ME1111 showed potent antifungal activity against Trichophyton rubrum and Trichophyton mentagrophytes (the major etiologic agents of onychomycosis) strains isolated in Japan and reference fungal strains with an MIC range of 0.12 to 0.5 mg/liter and an MIC50 and MIC90 of 0.5 mg/liter for both. Importantly, none of the tested isolates showed an elevated ME1111 MIC. Moreover, the antifungal activity of ME1111 was minimally affected by 5% wool keratin powder in comparison to the other antifungals tested. The ME1111 solution was able to penetrate human nails and inhibit fungal growth in a dose-dependent manner according to the TurChub assay. In contrast, 8% ciclopirox and 5% amorolfine nail lacquers showed no activity under the same conditions. ME1111 demonstrated approximately 60-fold-greater selectivity in inhibition of Trichophyton spp. than of human cell lines. Our findings demonstrate that ME1111 possesses potent antidermatophyte activity, maintains this activity in the presence of keratin, and possesses excellent human nail permeability. These results suggest that ME1111 is a promising topical medication for the treatment of onychomycosis and therefore warrants further clinical evaluation. PMID:26643333

In Vitro Susceptibilities of Isolates of Sporothrix schenckii to Itraconazole and Terbinafine

PubMed Central

Kohler, Lidiane Meire; Monteiro, Paulo César Fialho; Hahn, Rosane Christine; Hamdan, Júnia Soares

2004-01-01

Thirty isolates of the yeast form of Sporothrix schenckii were evaluated for in vitro susceptibility to itraconazole and terbinafine by the recommended NCCLS modified technique (M27-A2). The MICs of itraconazole obtained oscillated between 0.062 and 4.0 μg/ml, and those of terbinafine oscillated between 0.007 and 0.50 μg/ml; therefore, terbinafine showed greater in vitro activity. PMID:15365033

Identification, antifungal susceptibility and scanning electron microscopy of a keratinolytic strain of Rhodotorula mucilaginosa: a primary causative agent of onychomycosis.

PubMed

da Cunha, Marcel M L; dos Santos, Luana P B; Dornelas-Ribeiro, Marcos; Vermelho, Alane B; Rozental, Sonia

2009-04-01

Onychomycosis is a dermatological problem of high prevalence that mainly affects the hallux toenail. Onychomycosis caused by the yeast Rhodotorula mucilaginosa was identified using colony morphology, light microscopy, urease and carbohydrate metabolism in a 57-year-old immunocompetent patient from Rio de Janeiro, Brazil. High-resolution scanning electron microscopy of nail fragments, processed by a noncoating method, led to the observation with fine detail of the structures of both nail and fungus involved in the infection. Yeasts were mainly found inside grooves in the nail. Budding yeasts presented a spiral pattern of growth and blastoconidia were found in the nail groove region. Keratinase assays and keratin enzymography revealed that this isolate was highly capable of degrading keratin. Antifungal susceptibility tests showed that the fungus was susceptible to low concentrations of amphotericin B and 5-flucytosine and resistant to high concentrations of fluconazole, itraconazole, voriconazole and terbinafine. These findings showed data for the first time concerning the interaction of R. mucilaginosa in toenail infection and suggest that this emerging yeast should also be considered an opportunistic primary causative agent of onychomycosis.

Rapamycin exerts antifungal activity in vitro and in vivo against Mucor circinelloides via FKBP12-dependent inhibition of Tor.

PubMed

Bastidas, Robert J; Shertz, Cecelia A; Lee, Soo Chan; Heitman, Joseph; Cardenas, Maria E

2012-03-01

The zygomycete Mucor circinelloides is an opportunistic fungal pathogen that commonly infects patients with malignancies, diabetes mellitus, and solid organ transplants. Despite the widespread use of antifungal therapy in the management of zygomycosis, the incidence of infections continues to rise among immunocompromised individuals. In this study, we established that the target and mechanism of antifungal action of the immunosuppressant rapamycin in M. circinelloides are mediated via conserved complexes with FKBP12 and a Tor homolog. We found that spontaneous mutations that disrupted conserved residues in FKBP12 conferred rapamycin and FK506 resistance. Disruption of the FKBP12-encoding gene, fkbA, also conferred rapamycin and FK506 resistance. Expression of M. circinelloides FKBP12 (McFKBP12) complemented a Saccharomyces cerevisiae mutant strain lacking FKBP12 to restore rapamycin sensitivity. Expression of the McTor FKBP12-rapamycin binding (FRB) domain conferred rapamycin resistance in S. cerevisiae, and McFKBP12 interacted in a rapamycin-dependent fashion with the McTor FRB domain in a yeast two-hybrid assay, validating McFKBP12 and McTor as conserved targets of rapamycin. We showed that in vitro, rapamycin exhibited potent growth inhibitory activity against M. circinelloides. In a Galleria mellonella model of systemic mucormycosis, rapamycin improved survival by 50%, suggesting that rapamycin and nonimmunosuppressive analogs have the potential to be developed as novel antifungal therapies for treatment of patients with mucormycosis.

Antibacterial and antifungal activities from Siamese crocodile blood.

PubMed

Leelawongtawon, Ratree; Siruntawineti, Jindawan; Chaeychomsri, Win; Sattaponpan, Chisanucha

2010-12-01

To evaluate the in vitro antimicrobial activity of the Siamese crocodile blood against bacteria and fungi. Thirty Siamese crocodile blood samples including freeze dried whole blood (FDWB), fresh serum (FS), and freeze dried serum (FDS) were evaluated for antimicrobial susceptibility and MIC values against ATCC-registered strains of nine bacterial species and two fungal species and one fungus isolated from a clinical specimen, by using the standard broth microdilution method and a modified resazurin microtiter plate assay. The result showed that FS (80 mg/ml) and FDS (100 mg/ml) inhibited Gram negative bacteria including Enterobacter aerogenes ATCC 13048, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 27736, Salmonella typhimurium ATCC 13311 and Pseudomonas aeruginosa ATCC 27853 with the susceptibility rate at 23.30%, 10.00%, 40.00%, 70.00%, and 86.67%, respectively for FS, and 30.00%, 10.00%, 43.33%, 76.67% and 90.00%, respectively for FDS. The MIC and MBC were in the range of 12.50-100.00 mg/ml and 25.00-100.00 mg/m1 respectively. FS and FDS also inhibited Cryptococcus neoformans 250309 and Aspergillus niger with the susceptibility rate at 90.00% and 80.00%, respectively for FS and 100.00% and 83.33%, respectively for FDS. The MIC was in the range of 25.00-100.00 mg/ml. However, FS and FDS did not inhibit Gram positive bacteria and did not kill fungi. FDWB (100 mg/ml) could neither inhibit bacteria nor fungi. FS and FDS from Siamese crocodile exhibited potential antibacterial and antifungal activities.

ANTIFUNGAL ACTIVITY OF Cymbopogon nardus (L.) Rendle (CITRONELLA) AGAINST Microsporum canis FROM ANIMALS AND HOME ENVIRONMENT

PubMed Central

CAPOCI, Isis Regina Grenier; da CUNHA, Michele Milano; BONFIM-MENDONÇA, Patricia de Souza; GHIRALDI-LOPES, Luciana Dias; BAEZA, Lilian Cristiane; KIOSHIMA, Erika Seki; SVIDZINSKI, Terezinha Inez Estivalet

2015-01-01

Dermatophytosis is a common zoonosis in urban centers. Dogs and cats have played an important role as its disseminators. Environmental decontamination is essential for the prevention of its propagation to humans and animals. However, sanitizers or disinfectants with antifungal activity, currently available, have high toxicity. The present study evaluated the in vitro effects of an extract of citronella (Cymbopogon nardus) on 31 Microsporum canis isolates from animals and home environments. Susceptibility tests were performed based on document M38-A2 (2008) of the Clinical and Laboratory Standards Institute with modifications for natural products. Although susceptibility variation was observed between the fungus tested, the concentrations that inhibited the growth of 50 and 90% of the microorganisms were low (19.5 and 78 µg/mL, respectively). Thus, this citronella extract showed potent fungistatic and fungicide activities against M. canis isolated from animals and home environments. Therefore, it could be an alternative for dermatophytosis prophylaxis in the home environment. PMID:27049705

In vitro antifungal activity of hydroxychavicol isolated from Piper betle L

PubMed Central

2010-01-01

Background Hydroxychavicol, isolated from the chloroform extraction of the aqueous leaf extract of Piper betle L., (Piperaceae) was investigated for its antifungal activity against 124 strains of selected fungi. The leaves of this plant have been long in use tropical countries for the preparation of traditional herbal remedies. Methods The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of hydroxychavicol were determined by using broth microdilution method following CLSI guidelines. Time kill curve studies, post-antifungal effects and mutation prevention concentrations were determined against Candida species and Aspergillus species "respectively". Hydroxychavicol was also tested for its potential to inhibit and reduce the formation of Candida albicans biofilms. The membrane permeability was measured by the uptake of propidium iodide. Results Hydroxychavicol exhibited inhibitory effect on fungal species of clinical significance, with the MICs ranging from 15.62 to 500 μg/ml for yeasts, 125 to 500 μg/ml for Aspergillus species, and 7.81 to 62.5 μg/ml for dermatophytes where as the MFCs were found to be similar or two fold greater than the MICs. There was concentration-dependent killing of Candida albicans and Candida glabrata up to 8 × MIC. Hydroxychavicol also exhibited an extended post antifungal effect of 6.25 to 8.70 h at 4 × MIC for Candida species and suppressed the emergence of mutants of the fungal species tested at 2 × to 8 × MIC concentration. Furthermore, it also inhibited the growth of biofilm generated by C. albicans and reduced the preformed biofilms. There was increased uptake of propidium iodide by C. albicans cells when exposed to hydroxychavicol thus indicating that the membrane disruption could be the probable mode of action of hydroxychavicol. Conclusions The antifungal activity exhibited by this compound warrants its use as an antifungal agent particularly for treating topical infections, as well as gargle

Antifungal activity of the essential oil from Calendula officinalis L. (asteraceae) growing in Brazil.

PubMed

Gazim, Zilda Cristiane; Rezende, Claudia Moraes; Fraga, Sandra Regina; Svidzinski, Terezinha Inez Estivaleti; Cortez, Diógenes Aparicio Garcia

2008-01-01

This study tested in vitro activity of the essential oil from flowers of Calendula officinalis using disk-diffusion techniques. The antifungal assay results showed for the first time that the essential oil has good potential antifungal activity: it was effective against all 23 clinical fungi strains tested.

In vitro antifungal activity and probable fungicidal mechanism of aqueous extract of Barleria grandiflora.

PubMed

Kumari, Suman; Jain, Preeti; Sharma, Bhawana; Kadyan, Preeti; Dabur, Rajesh

2015-04-01

Barleria grandiflora Dalz. (Acanthaceae) is being used in India to treat different types of disorders including skin infections. Therefore, there are good possibilities to find antifungal compounds in its extracts with novel mechanism of action. The main objectives of the present study were to evaluate the antifungal activity of plant extracts and to study its effects on metabolic pathways of A. fumigatus. The microbroth dilution assay was used to explore antifungal activity and MIC of various extracts. Metabolic profiles of control and treated cultures were collected from Q-TOF-MS interfaced with HPLC. Affected metabolic pathways of A. fumigatus after the treatment were analyzed by discrimination analysis of mass data. Antifungal activities were observed in hot and cold water extracts of the plant. Hot water extract of B. grandiflora showed significant activity against tested fungi in the range 0.625-1.25 mg/mL. Partial least discrimination analysis revealed that the hot water plant extract downregulated amino acid, glyoxylate pathway, and methylcitrate pathways at the same time due to the synergistic effects of secondary metabolites. Hot water extract also downregulated several other metabolic pathways unique to fungi indicating its specific activity toward fungi. B. grandiflora showed promising antifungal activity which can further be exploited by identification of active compounds, to inhibit the specific fungal pathways and development of novel therapeutic antifungal drugs.

Dihydroorotate dehydrogenase inhibitor F901318 has potent in vitro activity against Scedosporium species and Lomentospora prolificans.

PubMed

Wiederhold, Nathan P; Law, Derek; Birch, Michael

2017-07-01

Scedosporium species and Lomentospora prolificans are increasing causes of invasive infections in immunocompromised hosts and many isolates are resistant to available antifungals. Our objective was to assess the in vitro potency of F901318, a member of the orotomide class of antifungals, against Scedosporium species and L. prolificans . The in vitro potency of F901318 was evaluated against 66 Scedosporium and 7 L. prolificans clinical isolates using the CLSI M38-A2 reference standard. Scedosporium species included Scedosporium apiospermum ( n  =   43), Scedosporium aurantiacum ( n  =   6), Scedosporium dehoogii ( n  =   2) and Scedosporium boydii ( n  =   15). Positive comparators included amphotericin B, caspofungin, posaconazole and voriconazole. Against S. apiospermum and S. boydii F901318 geometric mean MICs/MECs (0.079 and 0.046 mg/L, respectively) were significantly lower than those observed with amphotericin (3.404 and 5.595 mg/L), posaconazole (1.937 and 1.823 mg/L), voriconazole (0.784 and 0.630 mg/L) and caspofungin (5.703 and 7.639 mg/L) ( P  <   0.001). Against S. aurantiacum and S. dehoogii the F901318 MIC range (0.12-0.5 mg/L) was also lower than those for the other antifungals (0.5 to >8 mg/L). F901318 also maintained activity against L. prolificans isolates (range 0.12-0.25 mg/L) in contrast to other antifungals, of which none demonstrated in vitro activity. F901318 demonstrated potent in vitro activity against Scedosporium species and L. prolificans . This activity was maintained against isolates that had significantly reduced susceptibility to the other antifungals. Further studies are warranted to evaluate the in vivo efficacy of F901318 against Scedosporium species and L. prolificans . © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Antifungal activity of the essential oil from Calendula officinalis L. (asteraceae) growing in Brazil

PubMed Central

Gazim, Zilda Cristiane; Rezende, Claudia Moraes; Fraga, Sandra Regina; Svidzinski, Terezinha Inez Estivaleti; Cortez, Diógenes Aparicio Garcia

2008-01-01

This study tested in vitro activity of the essential oil from flowers of Calendula officinalis using disk-diffusion techniques. The antifungal assay results showed for the first time that the essential oil has good potential antifungal activity: it was effective against all 23 clinical fungi strains tested. PMID:24031180

In vitro antibacterial, antifungal and cytotoxic activities of some triazole Schiff bases and their oxovanadium(IV) complexes.

PubMed

Sumrra, Sajjad H; Chohan, Zahid H

2013-12-01

The condensation reaction of 3,5-diamino-1,2,4-triazole with methoxy-, chloro-, bromo-, iodo- and nitro-substituted 2-hydroxybenzaldehydes formed triazole Schiff bases (L(1))-(L(6)). The synthesized ligands have been characterized through physical, spectral and analytical data. Furthermore, the reaction of synthesized Schiff bases with the oxovanadium(IV) sulphate in (1:2) (metal:ligand) molar ratio afforded the oxovanadium(IV) complexes (1)-(6). All the complexes were non-electrolytic and showed a square-pyramidal geometry. The synthesized compounds have been screened for in-vitro antibacterial, antifungal and brine shrimp bioassay. The bioactivity data showed the complexes to be more active than the original Schiff bases.

Rapamycin Exerts Antifungal Activity In Vitro and In Vivo against Mucor circinelloides via FKBP12-Dependent Inhibition of Tor

PubMed Central

Bastidas, Robert J.; Shertz, Cecelia A.; Lee, Soo Chan; Heitman, Joseph

2012-01-01

The zygomycete Mucor circinelloides is an opportunistic fungal pathogen that commonly infects patients with malignancies, diabetes mellitus, and solid organ transplants. Despite the widespread use of antifungal therapy in the management of zygomycosis, the incidence of infections continues to rise among immunocompromised individuals. In this study, we established that the target and mechanism of antifungal action of the immunosuppressant rapamycin in M. circinelloides are mediated via conserved complexes with FKBP12 and a Tor homolog. We found that spontaneous mutations that disrupted conserved residues in FKBP12 conferred rapamycin and FK506 resistance. Disruption of the FKBP12-encoding gene, fkbA, also conferred rapamycin and FK506 resistance. Expression of M. circinelloides FKBP12 (McFKBP12) complemented a Saccharomyces cerevisiae mutant strain lacking FKBP12 to restore rapamycin sensitivity. Expression of the McTor FKBP12-rapamycin binding (FRB) domain conferred rapamycin resistance in S. cerevisiae, and McFKBP12 interacted in a rapamycin-dependent fashion with the McTor FRB domain in a yeast two-hybrid assay, validating McFKBP12 and McTor as conserved targets of rapamycin. We showed that in vitro, rapamycin exhibited potent growth inhibitory activity against M. circinelloides. In a Galleria mellonella model of systemic mucormycosis, rapamycin improved survival by 50%, suggesting that rapamycin and nonimmunosuppressive analogs have the potential to be developed as novel antifungal therapies for treatment of patients with mucormycosis. PMID:22210828

In Vitro Susceptibility of Plasmodium vivax to Antimalarials in Colombia

PubMed Central

Fernández, Diana; Segura, César; Arboleda, Margarita; Garavito, Giovanny; Blair, Silvia

2014-01-01

The in vitro susceptibilities of 30 isolates of Plasmodium vivax to a number of antimalarials (chloroquine [CQ], mefloquine, amodiaquine, quinine, and artesunate [AS]) were evaluated. The isolates came from the region of Urabá in Colombia, in which malaria is endemic, and were evaluated by the schizont maturation test. The 50% inhibitory concentration (IC50) was 0.6 nM (95% confidence interval [CI], 0.3 to 1.0 nM) for artesunate, 8.5 nM (95% CI, 5.6 to 13.0 nM) for amodiaquine, 23.3 nM (95% CI, 12.4 to 44.1 nM) for chloroquine, 55.6 nM (95% CI, 36.8 to 84.1 nM) for mefloquine, and 115.3 nM (95% CI, 57.7 to 230.5 nM) for quinine. The isolates were classified according to whether the initial parasites were mature or immature trophozoites (Tfz). It was found that the IC50s for chloroquine and artesunate were significantly different in the two aforementioned groups (P < 0.001). The IC50s of CQ and AS were higher in the isolates from mature Tfz (CQ, 39.3 nM versus 17 nM; AS, 1.4 nM versus 0.3 nM), and 10% of the isolates showed lower susceptibilities to one of the antimalarial drugs, 13.3% to two antimalarial drugs, and 3.3% to more than three antimalarial drugs. It should be highlighted that despite the extensive use of chloroquine in Colombia, P. vivax continues to be susceptible to antimalarials. This is the first report, to our knowledge, showing in vitro susceptibilities of P. vivax isolates to antimalarials in Colombia. PMID:25114141

Population-Based Survey of Filamentous Fungi and Antifungal Resistance in Spain (FILPOP Study)

PubMed Central

Mellado, E.; Peláez, T.; Pemán, J.; Zapico, S.; Alvarez, M.; Rodríguez-Tudela, J. L.; Cuenca-Estrella, M.

2013-01-01

A population-based survey was conducted to investigate the epidemiology of and antifungal resistance in Spanish clinical strains of filamentous fungi isolated from deep tissue samples, blood cultures, and respiratory samples. The study was conducted in two different periods (October 2010 and May 2011) to analyze seasonal variations. A total of 325 strains were isolated in 29 different hospitals. The average prevalence was 0.0016/1,000 inhabitants. Strains were identified by sequencing of DNA targets and susceptibility testing by the European Committee for Antimicrobial Susceptibility Testing reference procedure. The most frequently isolated genus was Aspergillus, accounting for 86.3% of the isolates, followed by Scedosporium at 4.7%; the order Mucorales at 2.5%; Penicillium at 2.2%, and Fusarium at 1.2%. The most frequent species was Aspergillus fumigatus (48.5%), followed by A. flavus (8.4%), A. terreus (8.1%), A. tubingensis (6.8%), and A. niger (6.5%). Cryptic/sibling Aspergillus species accounted for 12% of the cases. Resistance to amphotericin B was found in 10.8% of the isolates tested, while extended-spectrum triazole resistance ranged from 10 to 12.7%, depending on the azole tested. Antifungal resistance was more common among emerging species such as those of Scedosporium and Mucorales and also among cryptic species of Aspergillus, with 40% of these isolates showing resistance to all of the antifungal compounds tested. Cryptic Aspergillus species seem to be underestimated, and their correct classification could be clinically relevant. The performance of antifungal susceptibility testing of the strains implicated in deep infections and multicentric studies is recommended to evaluate the incidence of these cryptic species in other geographic areas. PMID:23669377

Breakpoints for antifungal agents: an update from EUCAST focussing on echinocandins against Candida spp. and triazoles against Aspergillus spp.

PubMed

Arendrup, Maiken C; Cuenca-Estrella, Manuel; Lass-Flörl, Cornelia; Hope, William W

2013-12-01

Candida and Aspergillus infections have emerged as significant pathogens in recent decades. During this same time, broad spectrum triazole and echinocandin antifungal agents have been developed and increasingly used. One consequence of widespread use is leading to the emergence of mutants with acquired resistance mutations. Therefore, accurate susceptibility testing and appropriate clinical breakpoints for the interpretation of susceptibility results have become increasingly important. Here we review the underlying methodology by which breakpoints have been selected by EUCAST (European Committee on Antimicrobial Susceptibility Testing). Five parameters are evaluated: dosing regimens used; EUCAST MIC distributions from multiple laboratories, species and compound specific epidemiological cut off values (upper MIC limits of wild type isolates or ECOFFs), pharmacokinetic/pharmacodynamic relationships and targets associated with outcome and finally clinical data by species and MIC when available. The general principles are reviewed followed by a detailed review of the individual aspects for Candida species and the three echinocandins and for Aspergillus and the three mould-active azoles. This review provides an update of the subcommittee on antifungal susceptibility testing (AFST) of the EUCAST methodology and summarises the current EUCAST breakpoints for Candida and Aspergillus. Recommendations about applicability of antifungal susceptibility testing in the routine setting are also included. Copyright © 2014 Elsevier Ltd. All rights reserved.

In vitro antioxidant, antifungal and antibacterial activities of five international Calibrachoa cultivars.

PubMed

Elansary, Hosam O; Yessoufou, Kowiyou

2016-06-01

The total phenolic, flavonoid and tannin contents in leaf extracts of Calibrachoa x hybrida (C.h.) (Solanaceae) international cultivars, as well as their overall antioxidant activities using DPPH and linoleic acid assays, were investigated. Furthermore, the antifungal and the antibacterial activities were examined against a wide spectrum of micro-organisms. DPPH and linoleic acid assays ranged from 62.1 to 80.1% and of 74.1-93.4%, respectively. C.h. Superbells® Trailing Rose (CHST), C.h. Superbells® Frost Fire, C.h. Superbells® Strawberry Punch, C.h. Superbells® Dreamsicle and C.h. Superbells® Plum (CHSP) varied in their antifungal and the antibacterial activities against a wide spectrum of micro-organisms. CHSP exhibited the highest antioxidant, antifungal and antibacterial activities followed by CHST. These activities might be attributed to the presence of phenolic, flavonoid and tannin compounds, indicating that these cultivars might be potential sources of therapeutic substances.

Effects of alcohols and ciclopirox alamine, an anti-fungal agent, on the peripheral blood lymphocyte functions in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prabhala, R.H.; Maxey, V.; Hicks, M.J.

1986-03-01

Effects of ethanol (1%), propanol (1%) and ciclopirox alamine, an anti-fungal agent, (4 ..mu..g/well), on the peripheral blood lymphocyte functions, including response to T- (Concanavalin A, ConA) and B-cell (Lipopolysaccharide, LPS) mitogens, and presence of functional T-lymphocyte subsets were determined in vitro. Purified human lymphocytes were incubated at 37/sup 0/C for 48 hours with or without test compounds in presence or absence of ConA and LPS. All three compounds suppress the response to T- or B-cell mitogens. The percentage of T-lymphocytes with T-helper characteristics in the presence of ethanol and ciclopirox alamine was increased. All three compounds suppressed the percentagemore » of T-lymphocytes with E-resetting characteristics. Alcohols enhanced the number of natural killer cells, whereas, ciclopirox alamine exhibited the reverse action. Although the alcohols and the anti-fungal agent enhanced the T-helper subpopulation, their response to mitogens was suppressed. This may be due to the suppression of T-cell activating lymphokines. Alcohol metabolite such as acetaldehyde also suppress the number of T-cells and their functions at 0.01% so may also be part of the explanation for immunoalteration.« less

Combination of fluconazole with non-antifungal agents: a promising approach to cope with resistant Candida albicans infections and insight into new antifungal agent discovery.

PubMed

Liu, Shuyuan; Hou, Yinglong; Chen, Xu; Gao, Yuan; Li, Hui; Sun, Shujuan

2014-05-01

The past decades have witnessed a dramatic increase in invasive fungal infections, especially candidiasis. Despite the development of more effective new antifungal agents, fluconazole (FLC) is still widely used in the clinic because of its efficacy and low toxicity. However, as the number of patients treated with FLC has increased, FLC-resistant Candida albicans isolates emerge more frequently. In addition, biofilm-associated infections are commonly encountered and their resistance poses a great challenge to antifungal treatment. Various approaches have been proposed to increase the susceptibility of C. albicans to FLC in order to cope with treatment failures, among which is the combination of FLC with different classes of non-antifungal agents such as antibacterials, calcineurin inhibitors, heat shock protein 90 inhibitors, calcium homeostasis regulators and traditional Chinese medicine drugs. Interestingly, many of these combinations showed synergistic effects against C. albicans, especially resistant strains. The main mechanisms of these synergistic effects appear to be increasing the permeability of the membrane, reducing the efflux of antifungal drugs, interfering with intracellular ion homeostasis, inhibiting the activity of proteins and enzymes required for fungal survival, and inhibiting biofilm formation. These modes of action and the antifungal mechanisms of various compounds referenced in this paper highlight the idea that the reversal of fungal resistance can be achieved through various mechanisms. Studies examining drug interactions will hopefully provide new approaches against antifungal drug resistance as well as insight into antifungal agent discovery. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Susceptibility of phaseolin to in vitro proteolysis is highly variable across common bean varieties (Phaseolus vulgaris).

PubMed

Montoya, Carlos A; Leterme, Pascal; Victoria, Nestor F; Toro, Orlando; Souffrant, Wolfgang B; Beebe, Stephen; Lallès, Jean-Paul

2008-03-26

A study was conducted to investigate the amino acid (AA) composition and the susceptibility to in vitro proteolysis (pepsin, 120 min and pancreatin, 240 min) of a collection of purified phaseolins ( n = 43) in unheated or heat-treated form. The AA composition of phaseolin varied little across bean varieties. At 360 min of in vitro proteolysis, the degree of hydrolysis varied from 11 to 27% for unheated and from 57 to 96% for heated phaseolins ( P < 0.001). Heat treatment markedly increased the susceptibility of phaseolin to proteolysis ( P < 0.001). The AA scores (AAS) and the protein digestibility corrected for AAS indicated S-containing AA as the limiting AA (39 +/- 3 and 30 +/- 5%, respectively). In conclusion, susceptibility to proteolysis of heat-treated phaseolin rather than its AA composition affects the nutritional value of phaseolin estimated in vitro. Therefore, it should be the criterion of choice in breeding programs aimed at improving the nutritional value of common beans for humans.

Rapid susceptibility testing of fungi by flow cytometry using vital staining.

PubMed Central

Wenisch, C; Linnau, K F; Parschalk, B; Zedtwitz-Liebenstein, K; Georgopoulos, A

1997-01-01

A 1-h assay for antifungal susceptibility testing measuring the impairment of fungal metabolic activity was developed. Yeast viability was analyzed by flow cytometry with a novel fluorescent probe, FUN-1, which emits a red fluorescence when the yeast is metabolically active. For nine Candida albicans strains tested, this method yielded results comparable to those obtained by the standard M27 procedure for amphotericin B, flucytosine, fluconazole, and ketoconazole. Whether the flow cytometry antifungal susceptibility test results correlate with the in vivo activities of the drugs remains to determined. PMID:8968873

Antifungal mechanism of a novel antifungal protein from pumpkin rinds against various fungal pathogens.

PubMed

Park, Seong-Cheol; Kim, Jin-Young; Lee, Jong-Kook; Hwang, Indeok; Cheong, Hyeonsook; Nah, Jae-Woon; Hahm, Kyung-Soo; Park, Yoonkyung

2009-10-14

A novel antifungal protein (Pr-2) was identified from pumpkin rinds using water-soluble extraction, ultrafiltration, cation exchange chromatography, and reverse-phase high-performance liquid chromatography. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry indicated that the protein had a molecular mass of 14865.57 Da. Automated Edman degradation showed that the N-terminal sequence of Pr-2 was QGIGVGDNDGKRGKR-. The Pr-2 protein strongly inhibited in vitro growth of Botrytis cinerea, Colletotrichum coccodes, Fusarium solani, Fusarium oxysporum, and Trichoderma harzianum at 10-20 microM. The results of confocal laser scanning microscopy and SYTOX Green uptake demonstrated that its effective region was the membrane of the fungal cell surface. In addition, this protein was found to be noncytotoxic and heat-stable. Taken together, the results of this study indicate that Pr-2 is a good candidate for use as a natural antifungal agent.

[Multiresistant Pseudomonas spp. in vitro susceptibility to a combination of two antibiotics].

PubMed

Pliego-Castañeda, Q F B Amanda; Yánez-Viguri, Jorge Antonio; López-Valle, Tiburcio

2005-01-01

In vitro antibiotic combination testing would guide therapy selection in patients severely affected by multi-drug resistant Pseudomonas. In vitro, a two-antibiotic combination susceptible against multi-drug resistant Pseudomonas isolated at the Laboratorio Clínico of the Hospital de Oncología, Centro Médico Nacional Siglo XXI in Mexico City were analyzed to determine which antibiotic combination showed the best bactericidal activity. During 10 months, 30 multi-drug resistant Pseudomonas strains were tested. An automated method was used, including a diluting solution with a well-known concentration of a second antibiotic. Quality controls recommended by the NCCLS were used. Pseudomonas aeruginosa ATCC 27853; Escherichia coli ATCC 25922; and Escherichia coli ATCC 35218. Combinations were betalactamics-aminoglycosides; carbapenemis-amikacin; fluoroquinolones-cefepime; and ciprofloxacin-ampicillin. Ampicillin-ciprofloxacin combination was bactericidal against 100% of the isolates. Cefazolin, cefixime and ticarcillin with amikacin: <50%; aztreonam, cefoxilin, cefuroxime, cefotaxime, ceftazidime and piperacillin with amikacin: 50-60%; cefepime with gentamicin: 76%; cefepime with amikacin: 86%; imipenem and meropenem with amikacin: 70% and 76%; cefepime with ciprofloxacin: 83%; cefepime with levofloxacin: 73%. In vitro antibiotic combination susceptibilities against multi-drug resistant bacteria would be the only way to guide clinicians to select the best therapy in severe infections. We found that the ampicillin-ciprofloxacin combination showed the best in vitro effect against multi-drug resistant Pseudomonas.

Melanins Protect Sporothrix brasiliensis and Sporothrix schenckii from the Antifungal Effects of Terbinafine.

PubMed

Almeida-Paes, Rodrigo; Figueiredo-Carvalho, Maria Helena Galdino; Brito-Santos, Fábio; Almeida-Silva, Fernando; Oliveira, Manoel Marques Evangelista; Zancopé-Oliveira, Rosely Maria

2016-01-01

Terbinafine is a recommended therapeutic alternative for patients with sporotrichosis who cannot use itraconazole due to drug interactions or side effects. Melanins are involved in resistance to antifungal drugs and Sporothrix species produce three different types of melanin. Therefore, in this study we evaluated whether Sporothrix melanins impact the efficacy of antifungal drugs. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of two Sporothrix brasiliensis and four Sporothrix schenckii strains grown in the presence of the melanin precursors L-DOPA and L-tyrosine were similar to the MIC determined by the CLSI standard protocol for S. schenckii susceptibility to amphotericin B, ketoconazole, itraconazole or terbinafine. When MICs were determined in the presence of inhibitors to three pathways of melanin synthesis, we observed, in four strains, an increase in terbinafine susceptibility in the presence of tricyclazole, a DHN-melanin inhibitor. In addition, one S. schenckii strain grown in the presence of L-DOPA had a higher MFC value when compared to the control. Growth curves in presence of 2×MIC concentrations of terbinafine showed that pyomelanin and, to a lesser extent, eumelanin were able to protect the fungi against the fungicidal effect of this antifungal drug. Our results suggest that melanin protects the major pathogenic species of the Sporothrix complex from the effects of terbinafine and that the development of new antifungal drugs targeting melanin synthesis may improve sporotrichosis therapies.

Quantitative structure-antifungal activity relationships of some benzohydrazides against Botrytis cinerea.

PubMed

Reino, José L; Saiz-Urra, Liane; Hernandez-Galan, Rosario; Aran, Vicente J; Hitchcock, Peter B; Hanson, James R; Gonzalez, Maykel Perez; Collado, Isidro G

2007-06-27

Fourteen benzohydrazides have been synthesized and evaluated for their in vitro antifungal activity against the phytopathogenic fungus Botrytis cinerea. The best antifungal activity was observed for the N',N'-dibenzylbenzohydrazides 3b-d and for the N-aminoisoindoline-derived benzohydrazide 5. A quantitative structure-activity relationship (QSAR) study has been developed using a topological substructural molecular design (TOPS-MODE) approach to interpret the antifungal activity of these synthetic compounds. The model described 98.3% of the experimental variance, with a standard deviation of 4.02. The influence of an ortho substituent on the conformation of the benzohydrazides was investigated by X-ray crystallography and supported by QSAR study. Several aspects of the structure-activity relationships are discussed in terms of the contribution of different bonds to the antifungal activity, thereby making the relationships between structure and biological activity more transparent.

Phenotypic Characterization and Antifungal Susceptibility Pattern to Fluconazole in Candida species Isolated from Vulvovaginal Candidiasis in a Tertiary Care Hospital

PubMed Central

Poongothai, G.K; Sinazer, Annie Rofeena; Kannaiyan, Kavitha; Gurumurthy, Hemalatha; Jaget, Nirmala; Kuthalaramalingam, Sethumadhavan

2014-01-01

Background: Vaginal candidiasis is a common gynecological finding among women worldwide. This study was carried out to determine the prevalence of vulvovaginal candidiasis (VVC) along with speciation of Candida with special reference to its antifungal susceptibility pattern to fluconazole and also to evaluate the risk factors responsible for VVC in patients attending our tertiary care hospital in Puducherry, India. Materials and Methods: This study was carried out in the tertiary care hospital in Puducherry during the period of August 2010 to September 2012.The study group consisted of 180 women between the age group of 15 to 56 years with the complaints of excessive vaginal discharge, pruritis and pain. Materials used for this study consisted of high vaginal swabs from patients with relevant history, attending Obstetrics & Gynecology department. High vaginal swabs were subjected to direct 10% KOH wet mount microscopy, Gram stain, culture onto Sabouraud’s dextrose agar (SDA) & 5% sheep blood agar and susceptibility testing to fluconazole was performed using E-test. Results: Candida was isolated in 40 (22.2 %) women & these consisted of C. albicans 26 (65%), C. glabrata 9 (22.5%), C.tropicalis 3 (7.5%) & C. parapsilosis 2 (5%). Susceptibility test carried out on the 40 isolates revealed that 35 (87.5%) Candida isolates were sensitive to fluconazole, 3 (7.5%) were moderately sensitive and 2 (2.5%) were resistant. Thirty one percent patients had itching as the presenting complaints followed by vaginal discharge (29.4%). Conclusion: The high frequency with which C. albicans was recovered in our study and its susceptibility to fluconazole supports the continued use of azole agents for empirical therapy of uncomplicated candidal vulvovaginitis in the community. PMID:24995172

Antifungal activity of Morinda citrifolia fruit extract against Candida albicans.

PubMed

Jainkittivong, Aree; Butsarakamruha, Tassanee; Langlais, Robert P

2009-09-01

The objective of the study was to investigate the antifungal activity of Morinda citrifolia fruit extract on Candida albicans. Juice extract from M. citrifolia fruit was lyophilized and used in antifungal testing. Antifungal activity of M. citrifolia fruit extract against C. albicans was tested in vitro at various concentrations and for different contact times. The inhibitory effect of M. citrifolia extract on C. albicans was determined by cultures and an applied broth dilution test. Using cultures, growth of C. albicans was not detected with 50 mg/mL of extract at 30-minute contact time or with 60 mg/mL of extract at 15-minute contact time. By the broth dilution test, the minimum fungicidal concentration of extract against C. albicans was 40 mg/mL at 90-minute contact time or with 50 mg/mL at 15-minute contact time. M. citrifolia fruit extract had an antifungal effect on C. albicans and the inhibitory effect varied with concentration and contact time.

In vitro susceptibility testing of Malassezia pachydermatis to gentamicin.

PubMed

Silva, Freddy A; Ferrer, Otilia; Déniz, Soraya; Rosario, Inmaculada; Conde-Felipe, Magnolia; Díaz, Esther L; Acosta-Hernández, Begoña

2017-08-01

Two studies have observed that growth media containing gentamicin can inhibit the growth of the yeast organism Malassezia pachydermatis. The minimum inhibitory concentration (MIC) of this bactericidal antibiotic for this organism has not been previously determined. To evaluate the susceptibility of M. pachydermatis isolates to gentamicin. The MIC of gentamicin was determined using a modified version of the M27-A3 microdilution method following the guidelines of the Clinical and Laboratory Standards Institute. A modified Christensen's urea broth was used to enhance the growth of the M. pachydermatis isolates. Visual and spectrophotometric end-point readings were performed to detect the presence or absence of yeast growth. The MIC50 and MIC90 of gentamicin were 8.12 μg/mL and 32.5 μg/mL, respectively; M. pachydermatis strains were classified as susceptible (S), intermediate (I) and resistant (R). The susceptibility of these isolates to gentamicin in vitro, by visual and spectrophotometric end-point reading, was: S, 54-56%; I, 40-41%; and R, 3-6%. Prospective MICs for M. pachydermatis have been established for gentamicin. © 2017 ESVD and ACVD.

Antifungal adjuvants: Preserving and extending the antifungal arsenal

PubMed Central

Butts, Arielle; Palmer, Glen E.; Rogers, P. David

2017-01-01

ABSTRACT As the rates of systemic fungal infections continue to rise and antifungal drug resistance becomes more prevalent, there is an urgent need for new therapeutic options. This issue is exacerbated by the limited number of systemic antifungal drug classes. However, the discovery, development, and approval of novel antifungals is an extensive process that often takes decades. For this reason, there is growing interest and research into the possibility of combining existing therapies with various adjuvants that either enhance activity or overcome existing mechanisms of resistance. Reports of antifungal adjuvants range from plant extracts to repurposed compounds, to synthetic peptides. This approach would potentially prolong the utility of currently approved antifungals and mitigate the ongoing development of resistance. PMID:27459018

Selective BET bromodomain inhibition as an antifungal therapeutic strategy

PubMed Central

Mietton, Flore; Ferri, Elena; Champleboux, Morgane; Zala, Ninon; Maubon, Danièle; Zhou, Yingsheng; Harbut, Mike; Spittler, Didier; Garnaud, Cécile; Courçon, Marie; Chauvel, Murielle; d'Enfert, Christophe; Kashemirov, Boris A.; Hull, Mitchell; Cornet, Muriel; McKenna, Charles E.; Govin, Jérôme; Petosa, Carlo

2017-01-01

Invasive fungal infections cause significant morbidity and mortality among immunocompromised individuals, posing an urgent need for new antifungal therapeutic strategies. Here we investigate a chromatin-interacting module, the bromodomain (BD) from the BET family of proteins, as a potential antifungal target in Candida albicans, a major human fungal pathogen. We show that the BET protein Bdf1 is essential in C. albicans and that mutations inactivating its two BDs result in a loss of viability in vitro and decreased virulence in mice. We report small-molecule compounds that inhibit C. albicans Bdf1 with high selectivity over human BDs. Crystal structures of the Bdf1 BDs reveal binding modes for these inhibitors that are sterically incompatible with the human BET-binding pockets. Furthermore, we report a dibenzothiazepinone compound that phenocopies the effects of a Bdf1 BD-inactivating mutation on C. albicans viability. These findings establish BET inhibition as a promising antifungal therapeutic strategy and identify Bdf1 as an antifungal drug target that can be selectively inhibited without antagonizing human BET function. PMID:28516956

Augmented antifungal potential of benzothiazol-2-ylcarbamodithioates as hybrid-silver aqua nanoformulations

NASA Astrophysics Data System (ADS)

Sidhu, Anjali; Ghatelwal, Suman R.; Gumber, Khushbu; Bala, Anju

2017-11-01

This study was focused on the preparation of benzothiazol-2-ylcarbamodithioates-silver nanoconjugates (BCDTC-AgNPs) for their in vitro antifungal evaluation against various phytopathogenic fungi viz. Pyricularia grisea, Drechslera oryzae, Fusarium moniliforme and Ustilaginoidea virens. Benzothiazol-2-ylcarbamodithioates (BCDTCs) were used both as capping as well as stabilizing for silver nanoparticles (AgNPs). The prepared nanoconjugates were analysed by UV-visible and TEM studies. The comparative antifungal evaluation of BCDTC-AgNPs with precursor BCDTCs and AgNPs indicated the manifold increase in antifungal potential when applied as nanoconjugates. The promising results were comparable to the standard commercial fungicides Tilt and Bavistin, in most of the cases.

Ethyl p-coumarate exerts antifungal activity in vitro and in vivo against fruit Alternaria alternata via membrane-targeted mechanism.

PubMed

Li, Wusun; Yuan, Shuzhi; Sun, Jing; Li, Qianqian; Jiang, Weibo; Cao, Jiankang

2018-08-02

The fungus Alternaria alternata can cause food contamination by black spot rot and food safety issues due to the production of mycotoxins. In particular, A. alternata can infect many fresh fruits and vegetables and lead to considerable postharvest decay during storage and processing. The use of plant-derived products in postharvest disease management may be an acceptable alternative to traditional chemical fungicides. The aim of this study was to assess the antifungal activity of ethyl p-coumarate (EpCA) against Alternaria alternata in vitro and in vivo, and to determine the underlying mechanism. Results indicated that EpCA exhibited pronounced antifungal activity against in vitro mycelial growth of A. alternata, with half-inhibition concentration of 176.8 μg/mL. Spore germination of the pathogen was inhibited by EpCA in a dose-dependent manner. Moreover, in vivo test confirmed that both 100 and 800 μg/mL EpCA significantly reduced disease development of black spot rot in jujube fruit caused by A. alternata. The EpCA treatments increased plasma membrane permeability as great leakage of intercellular electrolytes, soluble proteins and sugars of A. alternata occurred during incubation. The EpCA treatments also caused increase of the influx of propidium iodide, a fluorescence dye binding nucleus DNA, into the affected spores, indicating the disrupted plasma membrane integrity. Observations of ultrastructure further evidenced the damage to plasma membrane and morphology of A. alternata caused by EpCA, which resulted in distortion, sunken and shrivelled of spores and mycelia of the pathogen. In addition, fluorometric assay by confocal laser scanning microscopy confirmed that the EpCA treatments induced endogenous reactive oxygen species (ROS) formation in the spores of A. alternata, with stronger and more stable accumulation of ROS at higher concentration of EpCA. Therefore, heavy oxidative damage to cellular membranes and organelles might happen as demonstrated

Antifungal Therapy for Systemic Mycosis and the Nanobiotechnology Era: Improving Efficacy, Biodistribution and Toxicity.

PubMed

Souza, Ana C O; Amaral, Andre C

2017-01-01

Fungal diseases have been emerging as an important public health problem worldwide with the increase in host predisposition factors due to immunological dysregulations, immunosuppressive and/or anticancer therapy. Antifungal therapy for systemic mycosis is limited, most of times expensive and causes important toxic effects. Nanotechnology has become an interesting strategy to improve efficacy of traditional antifungal drugs, which allows lower toxicity, better biodistribution, and drug targeting, with promising results in vitro and in vivo . In this review, we provide a discussion about conventional antifungal and nanoantifungal therapies for systemic mycosis.

In vitro antifungal activity and mechanism of essential oil from fennel (Foeniculum vulgare L.) on dermatophyte species.

PubMed

Zeng, Hong; Chen, Xinping; Liang, Jingnan

2015-01-01

Fennel seed essential oil (FSEO) is a plant-derived natural therapeutic against dermatophytes. In this study, the antifungal effects of FSEO were investigated from varied aspects, such as MIC and minimum fungicidal concentration, mycelia growth, spore germination and biomass. The results indicated that FSEO had potent antifungal activities on Trichophyton rubrum ATCC 40051, Trichophyton tonsurans 10-0400, Microsporum gypseum 44693-1 and Trichophyton mentagrophytes 10-0060, which is better than the commonly used antifungal agents fluconazole and amphotericin B. Flow cytometry and transmission electron microscopy experiments suggested that the antifungal mechanism of FSEO was to damage the plasma membrane and intracellular organelles. Further study revealed that it could also inhibit the mitochondrial enzyme activities, such as succinate dehydrogenase, malate dehydrogenase and ATPase. With better antifungal activity than the commonly used antifungal agents and less possibility of inducing drug resistance, FSEO could be used as a potential antidermatophytic agent. © 2015 The Authors.

Effectiveness of Natural Antifungal Compounds in Controlling Infection by Grapevine Trunk Disease Pathogens through Pruning Wounds

PubMed Central

Cobos, Rebeca; Mateos, Rosa María; Álvarez-Pérez, José Manuel; Olego, Miguel Angel; Sevillano, Silvia; González-García, Sandra; Garzón-Jimeno, Enrique

2015-01-01

Grapevine trunk fungal pathogens, such as Diplodia seriata and Phaeomoniella chlamydospora, can infect plants through pruning wounds. They cause grapevine trunk diseases and are involved in grapevine decline. Accordingly, the protection of pruning wounds is crucial for the management of grapevine trunk diseases. The efficacy of different natural antifungals in inhibiting the growth of several fungi causing grapevine trunk diseases was evaluated in vitro. The fungi showing greater in vitro efficacy were tested on autoclaved grape wood assays against D. seriata and P. chlamydospora. Based on results from these assays, chitosan oligosaccharide, vanillin, and garlic extract were selected for further evaluation on pruning wounds inoculated with D. seriata and P. chlamydospora in field trials. A significant decrease in plant mortality was observed after 2 years of growth in the plants treated with the different natural antifungals compared to the mortality rate observed in infected plants that were not treated with antifungals. Also, the infection rate for the inoculated pathogens was significantly reduced in plants treated with the selected natural antifungals. Therefore, natural antifungals represent a promising alternative for disease control and could provide significant economic benefits for the grape-growing industry. PMID:26162882

Candida species isolated from different body sites and their antifungal susceptibility pattern: Cross-analysis of Candida albicans and Candida glabrata biofilms.

PubMed

Cataldi, Valentina; Di Campli, Emanuela; Fazii, Paolo; Traini, Tonino; Cellini, Luigina; Di Giulio, Mara

2017-08-01

Candida species are regular commensal in humans, but-especially in immunocompromised patients-they represent opportunistic pathogens giving rise to systemic infection. The aim of the present work was to isolate and characterize for their antifungal profile Candida species from different body sites and to analyze the biofilms produced by C. albicans and C. glabrata isolates. Eighty-one strains of Candida species from 77 patients were identified. Epidemiological study showed that the most isolated species were C. albicans (44), C. glabrata (13) and C. parapsilosis (13) mainly from Hematology, Infectious Diseases, Medicine, Neonatology and Oncology Divisions, the majority of the biological samples were swabs (44) and blood cultures (16). The analysis of the biofilm formation was performed at 24 and 48-hours comparing resistant and susceptible strains of C. albicans to resistant and susceptible strains of C. glabrata. Candida albicans has a greater ability to form biofilm compared to C. glabrata, both in the susceptible and resistant strains reaching maturity after 24 hours with a complex structure composed of blastospores, pseudohyphae, and hyphae embedded in a matrix. On the contrary, C. glabrata biofilm was composed exclusively of blastospores that in the resistant strain, after 24 hours, were organized in a compact multilayer different to the discontinuous structure observed in the susceptible analyzed strains. In conclusion, the increasing of the incidence of Candida species infection together with their emerging drug resistance also related to the biofilm forming capability underline the need to monitor their distribution and susceptibility patterns for improving the surveillance and for a correct management of the infection. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Potential Use of Alginate-Based Carriers As Antifungal Delivery System

PubMed Central

Spadari, Cristina de Castro; Lopes, Luciana B.; Ishida, Kelly

2017-01-01

Fungal infections have become a major public health problem, growing in number and severity in recent decades due to an increase of immunocompromised patients. The use of therapeutic agents available to treat these fungal infections is limited by their toxicity, low bioavailability, antifungal resistance, and high cost of treatment. Thus, it becomes extremely important to search for new therapeutic options. The use of polymeric systems as drug carriers has emerged as a promising alternative to conventional formulations for antifungals. Alginate is a natural polymer that has been explored in the last decade for development of drug delivery systems due to its non-toxicity, biodegradability, biocompatibility, low cost, mucoadhesive, and non-immunogenic properties. Several antifungal agents have been incorporated in alginate-based delivery systems, including micro and nanoparticles, with great success, displaying promising in vitro and in vivo results for antifungal activities, reduction in the toxicity and the total drug dose used in the treatment, and improved bioavailability. This review aims at discussing the potential use and benefits of alginate-based nanocarriers and other delivery systems containing antifungal agents in the therapy of fungal infections. PMID:28194145

Synergy and antagonism between iron chelators and antifungal drugs in Cryptococcus.

PubMed

Lai, Yu-Wen; Campbell, Leona T; Wilkins, Marc R; Pang, Chi Nam Ignatius; Chen, Sharon; Carter, Dee A

2016-10-01

Fungal infections remain very difficult to treat, and developing new antifungal drugs is difficult and expensive. Recent approaches therefore seek to augment existing antifungals with synergistic agents that can lower the therapeutic dose, increase efficacy and prevent resistance from developing. Iron limitation can inhibit microbial growth, and iron chelators have been employed to treat fungal infections. In this study, chequerboard testing was used to explore combinations of iron chelators with antifungal agents against pathogenic Cryptococcus spp. with the aim of determining how disruption to iron homeostasis affects antifungal susceptibility. The iron chelators ethylenediaminetetraacetic acid (EDTA), deferoxamine (DFO), deferiprone (DFP), deferasirox (DSX), ciclopirox olamine and lactoferrin (LF) were paired with the antifungal agents amphotericin B (AmB), fluconazole, itraconazole, voriconazole and caspofungin. All chelators except for DFO increased the efficacy of AmB, and significant synergy was seen between AmB and LF for all Cryptococcus strains. Addition of exogenous iron rescued cells from the antifungal effect of LF alone but could not prevent inhibition by AmB + LF, indicating that synergy was not due primarily to iron chelation but to other properties of LF that were potentiated in the presence of AmB. Significant synergy was not seen consistently for other antifungal-chelator combinations, and EDTA, DSX and DFP antagonised the activity of azole drugs in strains of Cryptococcus neoformans var. grubii. This study highlights the range of interactions that can be induced by chelators and indicates that most antifungal drugs are not enhanced by iron limitation in Cryptococcus. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Antifungal resistance: current trends and future strategies to combat

PubMed Central

Wiederhold, Nathan P

2017-01-01

Antifungal resistance represents a major clinical challenge to clinicians responsible for treating invasive fungal infections due to the limited arsenal of systemically available antifungal agents. In addition current drugs may be limited by drug–drug interactions and serious adverse effects/toxicities that prevent their prolonged use or dosage escalation. Fluconazole resistance is of particular concern in non-Candida albicans species due to the increased incidence of infections caused by these species in different geographic locations worldwide and the elevated prevalence of resistance to this commonly used azole in many institutions. C. glabrata resistance to the echinocandins has also been documented to be rising in several US institutions, and a higher percentage of these isolates may also be azole resistant. Azole resistance in Aspergillus fumigatus due to clinical and environmental exposure to this class of agents has also been found worldwide, and these isolates can cause invasive infections with high mortality rates. In addition, several species of Aspergillus, and other molds, including Scedosporium and Fusarium species, have reduced susceptibility or pan-resistance to clinically available antifungals. Various investigational antifungals are currently in preclinical or clinical development, including several of them that have the potential to overcome resistance observed against the azoles and the echinocandins. These include agents that also target ergosterol and b-glucan biosynthesis, as well as compounds with novel mechanisms of action that may also overcome the limitations of currently available antifungal classes, including both resistance and adverse effects/toxicity. PMID:28919789

Stress proteins on the yeast cell surface determine resistance to osmotin, a plant antifungal protein.

PubMed

Yun, D J; Zhao, Y; Pardo, J M; Narasimhan, M L; Damsz, B; Lee, H; Abad, L R; D'Urzo, M P; Hasegawa, P M; Bressan, R A

1997-06-24

Strains of the yeast Saccharomyces cerevisiae differ in their sensitivities to tobacco osmotin, an antifungal protein of the PR-5 family. However, cells sensitive to tobacco osmotin showed resistance to osmotin-like proteins purified from the plant Atriplex nummularia, indicating a strict specificity between the antifungal protein and its target cell. A member of a gene family encoding stress proteins induced by heat and nitrogen limitation, collectively called Pir proteins, was isolated among the genes that conveyed resistance to tobacco osmotin to a susceptible strain. We show that overexpression of Pir proteins increased resistance to osmotin, whereas simultaneous deletion of all PIR genes in a tolerant strain resulted in sensitivity. Pir proteins have been immunolocalized to the cell wall. The enzymatic digestion of the cell wall of sensitive and resistant cells rendered spheroplasts equally susceptible to the cytotoxic action of tobacco osmotin but not to other osmotin-like proteins, indicating that the cell membrane interacts specifically with osmotin and facilitates its action. Our results demonstrate that fungal cell wall proteins are determinants of resistance to antifungal PR-5 proteins.

Bacterial and fungal keratitis in Upper Egypt: In vitro screening of enzymes, toxins and antifungal activity

PubMed Central

Gharamah, Abdullah A; Moharram, Ahmed M; Ismail, Mady A; AL-Hussaini, Ashraf K

2014-01-01

Purpose: This work was conducted to study the ability of bacterial and fungal isolates from keratitis cases in Upper Egypt to produce enzymes, toxins, and to test the isolated fungal species sensitivity to some therapeutic agents. Materials and Methods: One hundred and fifteen patients clinically diagnosed to have microbial keratitis were investigated. From these cases, 37 bacterial isolates and 25 fungal isolates were screened for their ability to produce extra-cellular enzymes in solid media. In addition, the ability of fungal isolates to produce mycotoxins and their sensitivity to 4 antifungal agents were tested. Results: Protease, lipase, hemolysins, urease, phosphatase, and catalase were detected respectively in 48.65%, 37.84%, 59.46%, 43.24%, 67.57%, and 100% out of 37 bacterial isolates tested. Out of 25 fungal isolates tested during the present study, 80% were positive for protease, 84% for lipase and urease, 28% for blood hemolysis, and 100% for phosphatase and catalase enzymes. Thirteen fungal isolates were able to produce detectable amounts of 7 mycotoxins in culture medium (aflatoxins (B1, B2, G1, and G2), sterigmatocystin, fumagillin, diacetoxyscirpenol, zearalenone, T-2 toxin, and trichodermin). Among the antifungal agents tested in this study, terbinafine showed the highest effect against most isolates in vitro. Conclusion: In conclusion, the ability of bacterial and fungal isolates to produce extracellular enzymes and toxins may be aid in the invasion and destruction of eye tissues, which, in turn, lead to vision loss. PMID:24008795

Melanins Protect Sporothrix brasiliensis and Sporothrix schenckii from the Antifungal Effects of Terbinafine

PubMed Central

Almeida-Paes, Rodrigo; Figueiredo-Carvalho, Maria Helena Galdino; Brito-Santos, Fábio; Almeida-Silva, Fernando; Oliveira, Manoel Marques Evangelista; Zancopé-Oliveira, Rosely Maria

2016-01-01

Terbinafine is a recommended therapeutic alternative for patients with sporotrichosis who cannot use itraconazole due to drug interactions or side effects. Melanins are involved in resistance to antifungal drugs and Sporothrix species produce three different types of melanin. Therefore, in this study we evaluated whether Sporothrix melanins impact the efficacy of antifungal drugs. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of two Sporothrix brasiliensis and four Sporothrix schenckii strains grown in the presence of the melanin precursors L-DOPA and L-tyrosine were similar to the MIC determined by the CLSI standard protocol for S. schenckii susceptibility to amphotericin B, ketoconazole, itraconazole or terbinafine. When MICs were determined in the presence of inhibitors to three pathways of melanin synthesis, we observed, in four strains, an increase in terbinafine susceptibility in the presence of tricyclazole, a DHN-melanin inhibitor. In addition, one S. schenckii strain grown in the presence of L-DOPA had a higher MFC value when compared to the control. Growth curves in presence of 2×MIC concentrations of terbinafine showed that pyomelanin and, to a lesser extent, eumelanin were able to protect the fungi against the fungicidal effect of this antifungal drug. Our results suggest that melanin protects the major pathogenic species of the Sporothrix complex from the effects of terbinafine and that the development of new antifungal drugs targeting melanin synthesis may improve sporotrichosis therapies. PMID:27031728

Synergy of the antibiotic colistin with echinocandin antifungals in Candida species.

PubMed

Zeidler, Ute; Bougnoux, Marie-Elisabeth; Lupan, Alexandru; Helynck, Olivier; Doyen, Antonia; Garcia, Zacarias; Sertour, Natacha; Clavaud, Cécile; Munier-Lehmann, Hélène; Saveanu, Cosmin; d'Enfert, Christophe

2013-06-01

Candida albicans is the most prevalent fungal pathogen of humans, causing a wide range of infections from harmless superficial to severe systemic infections. Improvement of the antifungal arsenal is needed since existing antifungals can be associated with limited efficacy, toxicity and antifungal resistance. Here we aimed to identify compounds that act synergistically with echinocandin antifungals and that could contribute to a faster reduction of the fungal burden. A total of 38 758 compounds were tested for their ability to act synergistically with aminocandin, a β-1,3-glucan synthase inhibitor of the echinocandin family of antifungals. The synergy between echinocandins and an identified hit was studied with chemogenomic screens and testing of individual Saccharomyces cerevisiae and C. albicans mutant strains. We found that colistin, an antibiotic that targets membranes in Gram-negative bacteria, is synergistic with drugs of the echinocandin family against all Candida species tested. The combination of colistin and aminocandin led to faster and increased permeabilization of C. albicans cells than either colistin or aminocandin alone. Echinocandin susceptibility was a prerequisite to be able to observe the synergy. A large-scale screen for genes involved in natural resistance of yeast cells to low doses of the drugs, alone or in combination, identified efficient sphingolipid and chitin biosynthesis as necessary to protect S. cerevisiae and C. albicans cells against the antifungal combination. These results suggest that echinocandin-mediated weakening of the cell wall facilitates colistin targeting of fungal membranes, which in turn reinforces the antifungal activity of echinocandins.

Terbinafine susceptibility and genotypic heterogeneity in clinical isolates of Trichophyton mentagrophytes by random amplified polymorphic DNA (RAPD).

PubMed

Alipour, M; Mozafari, N A

2015-03-01

The four RAPD systems tested in the present study have aimed at investigating DNA fingerprinting of Trichophyton mentagrophytes strains and the correlation between genotyping and antifungal susceptibility to terbinafine. Twenty-nine clinical isolates of T. mentagrophytes were recovered from patients suspected of having active dermatophytosis who were referred to the laboratory of medical mycology department in Tehran university. Then, they were subjected to conventional examination by performing direct microscopic examination, culture on primary media, physiological tests. The in vitro antifungal susceptibility of twenty-nine T. mentagrophytes isolates against terbinafine was evaluated by modified agar dilution method to determine the minimum inhibitory concentration (MIC). Twenty-one sensitive and eight resistant to terbinafine, were submitted to RAPD using 4 decamer primers (A, B, C, D) with the purpose of encountering a genetic marker to terbinafine sensibility and resistance. The UPGMA-Jaccard's correlation coefficient was used to build up dendogram that could represent clusters of similarity. According to their correlation coefficient, the samples were classified as much related (100%), moderately related (80%) and unrelated (<70%). All amplifications revealed distinct polymorphic bands and a total of 34 band positions was scored (0/1) for the 4 primers tested. Genetic distances between each of the isolates were calculated and cluster analysis was used to generate a dendrogram showing relationships between them. The combined dendrogram at an average similarity value of 65% grouped all strains into 2 (A, B) groups corresponding to their susceptibility reactions to terbinafine. All susceptible samples were properly grouped, but a few numbers of resistant isolates were also included. Nevertheless, further biochemical and molecular biological studies will be required to fully elucidate the point that resistance might be the result of a mutation in the gene

Prevalence, virulence factors and antifungal susceptibility of Candida spp. isolated from bloodstream infections in a tertiary care hospital in Brazil.

PubMed

Canela, Heliara Maria Spina; Cardoso, Bárbara; Vitali, Lucia Helena; Coelho, Harnoldo Colares; Martinez, Roberto; Ferreira, Márcia Eliana da Silva

2018-01-01

Candida spp. are responsible for 80% of all systemic fungal infections and are associated with high mortality rates. This study characterised 79 bloodstream isolates of C. albicans, C. glabrata, C. orthopsilosis, C. parapsilosis and C. tropicalis from patients in a Brazilian hospital. The susceptibility to amphotericin B, caspofungin, fluconazole and voriconazole was determined; virulence factor production was assessed based on haemolysin, phospholipase and proteinase activities, and the patients' clinical characteristics were analysed. C. albicans was the predominant species (44%), followed by C. glabrata (19%), C. tropicalis (19%), C. parapsilosis (14%) and C. orthopsilosis (4%). The candidemia incidence was 1.52 per 1000 admissions, and the crude mortality rate was 52%. One C. albicans isolate was resistant to fluconazole and voriconazole. Moreover, 20.2%, 2.5% and 3.8% of the isolates exhibited dose-dependent susceptibility to fluconazole, voriconazole and caspofungin, respectively. In conclusion, although the C. glabrata incidence was higher than that usually described in Brazil, its increase was previously observed in studies conducted worldwide. Furthermore, the azole resistance of the C. albicans isolate could be due to previous exposure to these antifungals. These results highlight the importance of epidemiological studies and will facilitate an improved understanding of candidemia in the studied hospital. © 2017 Blackwell Verlag GmbH.

Susceptibilities of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum strains to antimicrobial agents in vitro.

PubMed Central

ter Laak, E A; Noordergraaf, J H; Verschure, M H

1993-01-01

The purpose of this study was to determine the susceptibility of various strains of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum, which are prevalent causes of pneumonia in calves, to 16 antimicrobial agents in vitro. The MICs of the antimicrobial agents were determined by a serial broth dilution method for 16 field strains and the type strain of M. bovis, for 19 field strains and the type strain of M. dispar, and for 17 field strains of U. diversum. Final MICs for M. bovis and M. dispar were read after 7 days and final MICs for U. diversum after 1 to 2 days. All strains tested were susceptible to tylosin, kitasamycin, and tiamulin but were resistant to nifuroquine and streptomycin. Most strains of U. diversum were intermediately susceptible to oxytetracycline but fully susceptible to chlortetracycline; most strains of M. bovis and M. dispar, however, were resistant to both agents. Strains of M. dispar and U. diversum were susceptible to doxycycline and minocycline, but strains of M. bovis were only intermediately susceptible. Susceptibility or resistance to chloramphenicol, spiramycin, spectinomycin, lincomycin, or enrofloxacin depended on the species but was not equal for the three species. The type strains of M. bovis and M. dispar were more susceptible to various antimicrobial agents, including tetracyclines, than the field strains. This finding might indicate that M. bovis and M. dispar strains are becoming resistant to these agents. Antimicrobial agents that are effective in vitro against all three mycoplasma species can be considered for treating mycoplasma infections in pneumonic calves. Therefore, tylosin, kitasamycin, and tiamulin may be preferred over oxytetracycline and chlortetracycline. PMID:8452363

Susceptibilities of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum strains to antimicrobial agents in vitro.

PubMed

ter Laak, E A; Noordergraaf, J H; Verschure, M H

1993-02-01

The purpose of this study was to determine the susceptibility of various strains of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum, which are prevalent causes of pneumonia in calves, to 16 antimicrobial agents in vitro. The MICs of the antimicrobial agents were determined by a serial broth dilution method for 16 field strains and the type strain of M. bovis, for 19 field strains and the type strain of M. dispar, and for 17 field strains of U. diversum. Final MICs for M. bovis and M. dispar were read after 7 days and final MICs for U. diversum after 1 to 2 days. All strains tested were susceptible to tylosin, kitasamycin, and tiamulin but were resistant to nifuroquine and streptomycin. Most strains of U. diversum were intermediately susceptible to oxytetracycline but fully susceptible to chlortetracycline; most strains of M. bovis and M. dispar, however, were resistant to both agents. Strains of M. dispar and U. diversum were susceptible to doxycycline and minocycline, but strains of M. bovis were only intermediately susceptible. Susceptibility or resistance to chloramphenicol, spiramycin, spectinomycin, lincomycin, or enrofloxacin depended on the species but was not equal for the three species. The type strains of M. bovis and M. dispar were more susceptible to various antimicrobial agents, including tetracyclines, than the field strains. This finding might indicate that M. bovis and M. dispar strains are becoming resistant to these agents. Antimicrobial agents that are effective in vitro against all three mycoplasma species can be considered for treating mycoplasma infections in pneumonic calves. Therefore, tylosin, kitasamycin, and tiamulin may be preferred over oxytetracycline and chlortetracycline.

Synthesis of inulin derivatives with quaternary phosphonium salts and their antifungal activity.

PubMed

Chen, Yuan; Tan, Wenqiang; Li, Qing; Dong, Fang; Gu, Guodong; Guo, Zhanyong

2018-07-01

Inulin is a kind of renewable and biodegradable carbohydrate with good water solubility and numerous physiological functions. For further utilization of inulin, chemical modification can be applied to improve its bioactivities. In this paper, five novel inulin derivatives were synthesized via chemical modification with quaternary phosphonium salt. Their antifungal activity against three kinds of plant pathogens including Colletotrichum lagenarium, Phomopsis asparagi, and Fusarium oxysporum was assessed with radial growth assay in vitro. Results revealed that all the inulin derivatives exhibited improved antifungal activity compared with inulin. Particularly, inulin modified with triphenylphosphine (TPhPAIL) exhibited the best antifungal activity with inhibitory indices of 80.0%, 78.8%, and 87.4% against Colletotrichum lagenarium, Phomopsis asparagi, and Fusarium oxysporum at 1.0mg/mL respectively. The results clearly showed that chemical modification of inulin with quaternary phosphonium salt could efficiently improve derivatives' antifungal activity. Further analysis of results indicated that the antifungal activity was influenced by alkyl chain length or electron-withdrawing ability of the grafted quaternary phosphonium salts. Longer alkyl chain lengths or the stronger electron-withdrawing groups would lead to enhanced antifungal efficacy. Copyright © 2018 Elsevier B.V. All rights reserved.

In vitro susceptibility of Helicobacter pullorum strains to different antimicrobial agents.

PubMed

Ceelen, Liesbeth; Decostere, Annemie; Devriese, Luc A; Ducatelle, Richard; Haesebrouck, Freddy

2005-01-01

The in vitro activity of 13 antimicrobial agents against 23 Helicobacter pullorum strains from poultry (21) and human (two) origin, and one human H. canadensis strain was tested by the agar dilution method. With the H. pullorum strains, monomodal distributions of Minimum Inhibitory Concentrations (MICs) were seen with lincomycin, doxycycline, gentamicin, tobramycin, erythromycin, tylosin, metronidazole, and enrofloxacin in concentration ranges considered as indicating susceptibility in other bacteria. The normal susceptibility level for nalidixic acid was situated at or slightly above the MIC breakpoints proposed for Campylobacteriaceae. Ampicillin, ceftriaxone, and sulphamethoxazole-trimethoprim showed poor activity against H. pullorum. For the H. canadensis strain, a similar susceptibility pattern was seen, except for nalidixic acid and enrofloxacin, whose MIC of >512 and 8 microg/ml, respectively, indicated resistance of this agent. With spectinomycin, a bimodal distribution of the MICs was noted for the tested strains; eight H. pullorum isolates originating from one flock showed acquired resistance (MIC>512 microg/ml).

Rifaximin disc diffusion test for in vitro susceptibility testing of Clostridium difficile

PubMed Central

Huhulescu, Steliana; Sagel, Ulrich; Fiedler, Anita; Pecavar, Verena; Blaschitz, Marion; Wewalka, Guenther; Allerberger, Franz

2011-01-01

Rifaximin is a rifampicin derivative, poorly absorbed by the gastro-intestinal tract. We studied the in vitro susceptibility to rifamixin of 1082 Clostridium difficile isolates; among these,184 isolates from a strain collection were tested by an in-house rifaximin disc (40 µg) diffusion test, by an in-house rifaximin broth microdilution test, by rifampicin Etest and by rpoB gene sequencing. In the absence of respective CLSI or EUCAST MIC breakpoints for rifaximin and rifampicin against C. difficile we chose MIC ≥32 µg ml−1 as criterion for reduced in vitro susceptibility. To further validate the disc diffusion test 898 consecutive clinical isolates were analysed using the disc diffusion test, the Etest and rpoB gene sequence analysis for all resistant strains. Rifaximin broth microdilution tests of the 184 reference strains yielded rifaximin MICs ranging from 0.001 (n = 1) to ≥1024 µg ml−1 (n = 61); 62 isolates showed a reduced susceptibility (MIC ≥32 µg ml−1). All of these 62 strains showed rpoB gene mutations producing amino acid substitutions; the rifampicin- and rifaximin-susceptible strains showed either a wild-type sequence or silent amino acid substitutions (19 strains). For 11 arbitrarily chosen isolates with rifaximin MICs of >1024 µg ml−1, rifaximin end-point MICs were determined by broth dilution: 4096 µg ml−1 (n = 2), 8192 µg ml−1 (n = 6), 16 384 µg ml−1 (n = 2) and 32 678 µg ml−1 (n = 1). Rifampicin Etests on the 184 C. difficile reference strains yielded MICs ranging from ≤0.002 (n = 117) to ≥32 µg ml−1 (n = 59). Using a 38 mm inhibition zone as breakpoint for reduced susceptibility the use of rifaximin disc diffusion yielded 59 results correlating with those obtained by use of rifaximin broth microdilution in 98.4 % of the 184 strains tested. Rifampicin Etests performed on the 898 clinical isolates revealed that 67 isolates had MICs of ≥32 µg ml−1. There were no

Evaluation of 1,3-benzoxathiol-2-one Derivatives as Potential Antifungal Agents.

PubMed

Terra, Luciana; de L Chazin, Eliza; de S Sanches, Paola; Saito, Max; de Souza, Marcus V N; Gomes, Claudia R B; Wardell, James L; Wardell, Solange M S V; Sathler, Plinio C; Silva, Gabriela C C; Lione, Viviane O; Kalil, Marcos; Joffily, Ana; Castro, Helena C; Vasconcelos, Thatyana R A

2018-01-01

Over the last few years, fungal infections have emerged as a worrisome global public health problem. Candidiasis is a disease caused by Candida species and has been a problem worldwide mainly for immunosuppressed patients. Lately, the resistant strains and side effects have been reported as important issues for treating Candidiasis, which have to be solved by identifying new drugs. The goal of this work was to synthesize a series of 1,3-benzoxathiol-2-one derivatives, XYbenzo[ d][1,3]oxathiol-2-ones, and evaluate their antifungal activity against five Candida species. In vitro antifungal screening test and minimum inhibitory concentration determination were performed according to CLSI protocols using ketoconazole as the reference drug. The cytotoxicity of the most active compounds was evaluated by hemolysis and MTT (Vero cells) assays. Compounds 2 (XY = 6-hydroxy-5-nitro, MIC = 4-32 µg/mL) and 7 (XY = 6-acetoxy-5-nitro, MIC =16-64 µg/mL) showed good results when compared with current antifungals in CLSI values (MIC = 0.04-250 µg/mL). These compounds exhibited a safer cytotoxicity as well as a lower hemolytic profile than ketoconazole. Overall, the in vitro results pointed to the potential of compounds 2 and 7 as new antifungal prototypes to be further explored. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effect of Addition of Antifungal Agents on Physical and Biological Properties of a Tissue Conditioner: An In-Vitro Study.

PubMed

Rawat, Pragati; Agarwal, Swatantra; Tripathi, Siddhi

2017-09-01

Purpose: Tissue conditioners are used for healing of abused oral tissues. They may harbour microorganisms causing oral diseases such as candidiasis compromising the health of the patient. Also, addition of antifungal agents into tissue conditioner may alter its properties. This study compares the anti-fungal property and mechanical properties of tissue conditioner containing different antifungal agents. Methods: Three antifungal agents, one synthetic - fluconazole, and two natural - oregano oil and virgin coconut oil were added into the tissue conditioner (Viscogel) in different concentrations. The antifungal property, tensile bond strength and viscoelasticity of Viscogel containing these antifungal agents were assessed after 24 hours, three days and seven days. Results: While, the highest antifungal activity was shown by Viscogel containing fluconazole, the maximum tensile bond strength was found to be of Viscogel alone (control). Although Viscogel alone and in combination of fluconazole showed deterioration in viscoelasticity, Viscogel in combination of natural agents showed no significant changes over the period of seven days. Conclusion: Incorporation of the natural agents in the tissue conditioner can be used as an effective alternative to systemic or topical synthetic antifungal agents.

Trypanocide, cytotoxic, and antifungal activities of Momordica charantia.

PubMed

Santos, Karla K A; Matias, Edinardo F F; Sobral-Souza, Celestina E; Tintino, Saulo R; Morais-Braga, Maria F B; Guedes, Glaucia M M; Santos, Francisco A V; Sousa, Ana Carla A; Rolón, Miriam; Vega, Celeste; de Arias, Antonieta Rojas; Costa, José G M; Menezes, Irwin R A; Coutinho, Henrique D M

2012-02-01

Chagas disease, caused by Trypanosoma cruzi, is a public health problem. Currently, chemotherapy is the only available treatment for this disease, and the drugs used, nifurtimox and benzonidazol, present high toxicity levels. An alternative for replacing these drugs are natural extracts from Momordica charantia L. (Cucurbitaceae) used in traditional medicine because of their antimicrobial and biological activities. In this study, we evaluated the extract of M. charantia for its antiepimastigote, antifungal, and cytotoxic activities. An ethanol extract of leaves from M. charantia was prepared. To research in vitro antiepimastigote activity, T. cruzi CL-B5 clone was used. Epimastigotes were inoculated at a concentration of 1 × 10(5) cells/mL in 200 µl tryptose-liver infusion. For the cytotoxicity assay, J774 macrophages were used. The antifungal activity was evaluated by microdilution using strains of Candida albicans, Candida tropicalis, and Candida krusei. The effective concentration capable of killing 50% of parasites (IC(50)) was 46.06 µg/mL. The minimum inhibitory concentration (MIC) was ≤ 1024 µg/mL. Metronidazole showed a potentiation of its antifungal effect when combined with an extract of M. charantia. Our results indicate that M. charantia could be a source of plant-derived natural products with antiepimastigote and antifungal-modifying activity with moderate toxicity.

Antifungal Efficacy of an Intravenous Formulation Containing Monomeric Amphotericin B, 5-Fluorocytosine, and Saline for Sodium Supplementation

PubMed Central

Alvarez, Celeste; Andes, David R.; Kang, Jeong Yeon; Krug, Carmen; Kwon, Glen S.

2017-01-01

Purpose Amphotericin B (AmB) and 5-fluorocytosine (5-FC) exhibit additive to synergistic activity against systemic mycoses. Incompatibility of prescribed formulations precludes concomitant IV administration, a route with distinct advantages. Previously, we used PEG-DSPE micelles to produce a reformulation of Fungizone (AmB-SD), AmB solubilized by sodium deoxycholate, called mAmB-90. Herein, we describe a second reformulation that facilitates co-delivery of mAmB-90 and 5-FC, and evaluate the effect of PEG-DSPE micelles on the combination’s activity against Candida albicans. Methods We assessed the effect of 5-FC addition on the stability, in vitro toxicity, and antifungal efficacy of mAmB-90. The aggregation state and particle size of mAmB-90 combined with 5-FC (FmAmB-90) was evaluated over 48 hours. Hemolytic activity was measured in vitro. Antifungal activity was determined in vitro against C. albicans. The efficacy of monotherapy and combination treatment was evaluated in a neutropenic mouse model of disseminated candidiasis. Results The aggregation state, particle size, and hemolytic activity of mAmB-90 were unaffected by 5-FC. While antifungal activity was similar in vitro, mAmB-90 alone and combined with 5-FC was more potent than AmB-SD in vivo. Conclusions Short-term stability and in vivo efficacy of our formulation suggest potential to simultaneously deliver AmB and 5-FC for potent antifungal efficacy. PMID:28205003

Antifungal Efficacy of an Intravenous Formulation Containing Monomeric Amphotericin B, 5-Fluorocytosine, and Saline for Sodium Supplementation.

PubMed

Alvarez, Celeste; Andes, David R; Kang, Jeong Yeon; Krug, Carmen; Kwon, Glen S

2017-05-01

Amphotericin B (AmB) and 5-fluorocytosine (5-FC) exhibit additive to synergistic activity against systemic mycoses. Incompatibility of prescribed formulations precludes concomitant IV administration, a route with distinct advantages. Previously, we used PEG-DSPE micelles to produce a reformulation of Fungizone (AmB-SD), AmB solubilized by sodium deoxycholate, called mAmB-90. Herein, we describe a second reformulation that facilitates co-delivery of mAmB-90 and 5-FC, and evaluate the effect of PEG-DSPE micelles on the combination's activity against Candida albicans. We assessed the effect of 5-FC addition on the stability, in vitro toxicity, and antifungal efficacy of mAmB-90. The aggregation state and particle size of mAmB-90 combined with 5-FC (FmAmB-90) was evaluated over 48 h. Hemolytic activity was measured in vitro. Antifungal activity was determined in vitro against C. albicans. The efficacy of monotherapy and combination treatment was evaluated in a neutropenic mouse model of disseminated candidiasis. The aggregation state, particle size, and hemolytic activity of mAmB-90 were unaffected by 5-FC. While antifungal activity was similar in vitro, mAmB-90 alone and combined with 5-FC was more potent than AmB-SD in vivo. Short-term stability and in vivo efficacy of our formulation suggest potential to simultaneously deliver AmB and 5-FC for potent antifungal efficacy.

Epidemiology, Antifungal Susceptibility, and Pathogenicity of Candida africana Isolates from the United Kingdom

PubMed Central

Szekely, Adrien; Linton, Chistopher J.; Palmer, Michael D.; Brown, Phillipa; Johnson, Elizabeth M.

2013-01-01

Candida africana was previously proposed as a new species within the Candida albicans species complex, together with C. albicans and C. dubliniensis, although further phylogenetic analyses better support its status as an unusual variant within C. albicans. Here we show that C. africana can be distinguished from C. albicans and C. dubliniensis by pyrosequencing of a short region of ITS2, and we have evaluated its occurrence in clinical samples by pyrosequencing all presumptive isolates of C. albicans submitted to the Mycology Reference Laboratory over a 9-month period. The C. albicans complex constituted 826/1,839 (44.9%) of yeast isolates received over the study period and included 783 isolates of C. albicans, 28 isolates of C. dubliniensis, and 15 isolates of C. africana. In agreement with previous reports, C. africana was isolated exclusively from genital specimens, in women in the 18-to-35-year age group. Indeed, C. africana constituted 15/251 (6%) of “C. albicans” isolates from female genital specimens during the study period. C. africana isolates were germ tube positive, grew significantly more slowly than C. albicans and C. dubliniensis on conventional mycological media, could be distinguished from the other members of the C. albicans complex by appearance on chromogenic agar, and were incapable of forming chlamydospores. Here we present the detailed evaluation of epidemiological, phenotypic, and clinical features and antifungal susceptibility profiles of United Kingdom isolates of C. africana. Furthermore, we demonstrate that C. africana is significantly less pathogenic than C. albicans and C. dubliniensis in the Galleria mellonella insect systemic infection model. PMID:23303503

Application of cosmetic nail varnish does not affect the antifungal efficacy of amorolfine 5% nail lacquer in the treatment of distal subungual toenail onychomycosis: results of a randomised active-controlled study and in vitro assays.

PubMed

Sigurgeirsson, B; Ghannoum, M A; Osman-Ponchet, H; Kerrouche, N; Sidou, F

2016-05-01

As onychomycosis is unsightly, this study clinically evaluated whether the antifungal efficacy of amorolfine 5% nail lacquer (NL) was affected by a masking, natural-coloured, cosmetic nail varnish applied 24 h later; in vitro investigations were also performed. Subjects with mild-to-moderate distal subungual toenail onychomycosis were randomised to receive amorolfine 5% NL once weekly with or without cosmetic nail varnish applied 24 h later. After 12-week treatment, antifungal activity of affected toenail clippings was assessed by measurement of zones of inhibition (ZOIs) on Trichophyton mentagrophytes seeded agar plates. Mean diameters were 53.5 mm for the amorolfine 5% NL-alone group (n = 23) and 53.6 mm for amorolfine 5% NL plus cosmetic nail varnish group (n = 25). Also, mycological cultures of subungual debris at week 12 were negative for all subjects in both groups. Most subjects (88%) reported that cosmetic nail varnish masked their infected toenails. Additionally, cadaver human nails coated in vitro with or without cosmetic nail varnish 10 min or 24 h post amorolfine NL application all gave ZOIs on Trichophyton rubrum agar plates representing potent antifungal activity. In conclusion, cosmetic nail varnish applied post amorolfine had no effect on the subungual antifungal activity of amorolfine 5% NL or its penetration through toenails. © 2016 The Authors Mycoses published by Blackwell Verlag GmbH.

Plant latex: a promising antifungal agent for post harvest disease control.

PubMed

Sibi, G; Wadhavan, Rashmi; Singh, Sneha; Shukla, Abhilasha; Dhananjaya, K; Ravikumar, K R; Mallesha, H

2013-12-01

Bioactive compounds from plant latex are potential source of antifungic against post harvest pathogens. Latex from a total of seven plant species was investigated for its phytochemical and antifungal properties. Six fungi namely Aspergillus fumigatus, A. niger, A. terreus, F. solani, P. digitatum and R. arrhizus were isolated from infected fruits and vegetables and tested against various solvent extracts of latex. Analysis of latex extracts with phytochemical tests showed the presence of alkaloids, flavonoids, glycosides, phenols, saponins, steroids, tannins and terpenoids. Antifungal assay revealed the potential inhibitory activity of petroleum ether extracts against the postharvest fungal isolates. Various degree of sensitivity was observed irrespective of plant species studied with A. terreus and P. digitatum as the most susceptible ones. F. solani and A. fumigatus were moderately sensitive to the latex extracts tested. Among the plants, latex of Thevetia peruviana (75.2%) and Artocarpus heterophyllus (64.8%) were having potential antifungal activity against the isolates followed by Manilkara zapota (51.1%). In conclusion, use of plant latex makes interest to control postharvest fungal diseases and is fitting well with the concept of safety for human health and environment.

In Vitro Activities of Five Antifungal Drugs Against Opportunistic Agents of Aspergillus Nigri Complex.

PubMed

Badali, Hamid; Fakhim, Hamed; Zarei, Fereshteh; Nabili, Mojtaba; Vaezi, Afsane; Poorzad, Nafiseh; Dolatabadi, Somayeh; Mirhendi, Hossein

2016-04-01

Black aspergilli, particularly Aspergillus niger and A. tubingensis, are the most common etiological agents of otomycosis followed by onychomycosis, pulmonary aspergillosis and aspergilloma. However, so far there is no systematic study on their antifungal susceptibility profiles. A collection of 124 clinical and environmental species of black aspergilli consisted of A. niger, A. tubingensis, A. uvarum. A. acidus and A. sydowii were verified by DNA sequencing of the partial β-tubulin gene. MICs of amphotericin B, itraconazole, voriconazole, posaconazole, and MECs of caspofungin were performed based on CLSI M38-A2. Posaconazole and caspofungin had the lowest MIC range (0.016-0.125 µg/ml and 0.008-0.031 µg/ml, respectively), followed by amphotericin B (0.25-4 µg/ml), voriconazole (0.125-16 µg/ml) and itraconazole (0.25 to >16) in an increasing order. Some strains of A. niger showed high MIC value for itraconazole and voriconazole (>16 µg/ml), in contrast only environmental isolates of A. tubingensis had high itraconazole MICs (>16 µg/ml). These results confirm that posaconazole and caspofungin are potential drugs for treatment of aspergillosis due to opportunistic agents of Aspergillus Nigri complex. However, in vivo efficacy remains to be determined.

Dynamics of Mixed- Candida Species Biofilms in Response to Antifungals.

PubMed

Vipulanandan, G; Herrera, M; Wiederhold, N P; Li, X; Mintz, J; Wickes, B L; Kadosh, D

2018-01-01

Oral infections caused by Candida species, the most commonly isolated human fungal pathogen, are frequently associated with biofilms. Although Candida albicans is the predominant organism found in patients with oral thrush, a biofilm infection, there is an increasing incidence of oral colonization and infections caused by non- albicans Candida species, including C. glabrata, C. dubliniensis, and C. tropicalis, which are frequently more resistant to antifungal treatment. While single-species Candida biofilms have been well studied, considerably less is known about the dynamics of mixed- Candida species biofilms and how these dynamics are altered by antifungal treatment. To address these questions, we developed a quantitative polymerase chain reaction-based approach to determine the precise species composition of mixed- Candida species biofilms formed by clinical isolates and laboratory strains in the presence and absence of clinically relevant concentrations of 3 commonly used antifungals: fluconazole, caspofungin, and amphotericin B. In monospecies biofilms, fluconazole exposure favored growth of C. glabrata and C. tropicalis, while caspofungin generally favored significant growth of all species to a varying degree. Fluconazole was not effective against preformed mixed- Candida species biofilms while amphotericin B was potent. As a general trend, in mixed- Candida species biofilms, C. albicans lost dominance in the presence of antifungals. Interestingly, presence in mixed versus monospecies biofilms reduced susceptibility to amphotericin B for C. tropicalis and C. glabrata. Overall, our data suggest that antifungal treatment favors the growth of specific non- albicans Candida species in mixed- Candida species biofilms.

Synthesis and antifungal evaluation of PCA amide analogues.

PubMed

Qin, Chuan; Yu, Di-Ya; Zhou, Xu-Dong; Zhang, Min; Wu, Qing-Lai; Li, Jun-Kai

2018-04-18

To improve the physical and chemical properties of phenazine-1-carboxylic acid (PCA) and find higher antifungal compounds, a series of PCA amide analogues were designed and synthesized and their structures were confirmed by 1 H NMR, HRMS, and X-ray. Most compounds showed some antifungal activities in vitro. Particularly, compound 3d exhibited inhibition effect against Pyriculariaoryzac Cavgra with EC 50 value of 28.7 μM and compound 3q exhibited effect against Rhizoctonia solani with EC 50 value of 24.5 μM, more potently active than that of the positive control PCA with its EC 50 values of 37.3 μM (Pyriculariaoryzac Cavgra) and 33.2 μM (Rhizoctonia solani), respectively.

Antifungal susceptibility patterns of colonized Candida species isolates from immunocompromised pediatric patients in five university hospitals.

PubMed

Badiee, Parisa; Choopanizadeh, Maral; Moghadam, Abdolkarim Ghadimi; Nasab, Ali Hossaini; Jafarian, Hadis; Shamsizadeh, Ahmad; Soltani, Jafar

2017-12-01

Colonization of Candida species is common in pediatric patients admitted to hematology-oncology wards. The aim of this study was to identify colonized Candida species and their susceptibility patterns in hematologic pediatric patients. Samples were collected from mouth, nose, urine and stool of the patients admitted to five university hospitals and cultured on sabouraud dextrose agar. The isolates were identified by API 20 C AUX system and their susceptibility patterns were evaluated by CLSI M27-A3 and S4. From 650 patients, 320 (49.2%) were colonized with 387 Candida species. Candida albicans was the most prevalent isolated species, followed by Candida glabrata, Candida tropicalis, Candida famata, Candida kefyr and Candida kuresi . The epidemiological cut off value (ECV) for all Candida species to amphotericin B was ≤0.25 μg except C. krusei (4 μg). The resistance rate to fluconazole in this study in C. albicans was 4.9% with ECV 8 μg/ml, followed by C. tropicalis 8.8% with ECV 0.5 μg/ml. Voriconazole and posaconazole were effective antifungal agents for all Candida isolates. The ECV of C. albicans, Candida parapsilosis, C. tropicalis, C. glabrata and C. krusei for itraconazole were 0.5, 0.25, 0.5, 1 and 2 μg, respectively. The resistant and intermediate rates of Candida species to caspofungin in this study were 2.9%, 5.9%, 18.8%, 47.9%, 0.0% and 16.7% in C. tropicalis, C. glabrata and C. parapsilosis respectively. C. albicans was the most prevalent species in pediatric colonized patients. New azole agents like voriconazole and posaconazole are effective against non-albicans Candida species. Increase in intermediate species is alarming to future emerging resistant species.

Comparison of species-level identification and antifungal susceptibility results from diagnostic and reference laboratories for bloodstream Candida surveillance isolates, South Africa, 2009-2010.

PubMed

Naicker, Serisha D; Govender, Nevashan; Patel, Jaymati; Zietsman, Inge L; Wadula, Jeannette; Coovadia, Yacoob; Kularatne, Ranmini; Seetharam, Sharona; Govender, Nelesh P

2016-11-01

From February 2009 through August 2010, we compared species-level identification of bloodstream Candida isolates and susceptibility to fluconazole, voriconazole, and caspofungin between diagnostic and reference South African laboratories during national surveillance for candidemia. Diagnostic laboratories identified isolates to genus/species level and performed antifungal susceptibility testing, as indicated. At a reference laboratory, viable Candida isolates were identified to species-level using automated systems, biochemical tests, or DNA sequencing; broth dilution susceptibility testing was performed. Categorical agreement (CA) was calculated for susceptibility results of isolates with concordant species identification. Overall, 2172 incident cases were detected, 773 (36%) by surveillance audit. The Vitek 2 YST system (bioMérieux Inc, Marcy l'Etoile, France) was used for identification (360/863, 42%) and susceptibility testing (198/473, 42%) of a large proportion of isolates. For the five most common species (n = 1181), species-level identification was identical in the majority of cases (Candida albicans: 98% (507/517); Candida parapsilosis: 92% (450/488); Candida glabrata: 89% (89/100); Candida tropicalis: 91% (49/54), and Candida krusei: 86% (19/22)). However, diagnostic laboratories were significantly less likely to correctly identify Candida species other than C. albicans versus C. albicans (607/664, 91% vs. 507/517, 98%; P < .001). Susceptibility data were compared for isolates belonging to the five most common species and fluconazole, voriconazole, and caspofungin in 860, 580, and 99 cases, respectively. Diagnostic laboratories significantly under-reported fluconazole resistance in C. parapsilosis (225/393, 57% vs. 239/393, 61%; P < .001) but over-reported fluconazole non-susceptibility in C. albicans (36/362, 10% vs. 3/362, 0.8%; P < .001). Diagnostic laboratories were less likely to correctly identify Candida species other than C. albicans, under

Activities of Available and Investigational Antifungal Agents against Rhodotorula Species

PubMed Central

Diekema, D. J.; Petroelje, B.; Messer, S. A.; Hollis, R. J.; Pfaller, M. A

2005-01-01

Rhodotorula species are emerging pathogens in immunocompromised patients. We report the in vitro activities of eight antifungals against 64 Rhodotorula isolates collected in surveillance programs between 1987 and 2003. Rhodotorula strains are resistant in vitro to fluconazole (MIC at which 50% of the isolates tested are inhibited [MIC50], >128 μg/ml) and caspofungin (MIC50, >8 μg/ml). Amphotericin B (MIC50,1 μg/ml) and flucytosine (MIC50, 0.12 μg/ml) are both active in vitro, and the new and investigational triazoles all have some in vitro activity, with ravuconazole being the most active (MIC50, 0.25 μg/ml). PMID:15635020

Novel method to assess antiretroviral target trough concentrations using in vitro susceptibility data.

PubMed

Acosta, Edward P; Limoli, Kay L; Trinh, Lan; Parkin, Neil T; King, Jennifer R; Weidler, Jodi M; Ofotokun, Ighovwerha; Petropoulos, Christos J

2012-11-01

Durable suppression of HIV-1 replication requires the establishment of antiretroviral drug concentrations that exceed the susceptibility of the virus strain(s) infecting the patient. Minimum plasma drug concentrations (C(trough)) are correlated with response, but determination of target C(trough) values is hindered by a paucity of in vivo concentration-response data. In the absence of these data, in vitro susceptibility measurements, adjusted for serum protein binding, can provide estimations of suppressive in vivo drug concentrations. We derived serum protein binding correction factors (PBCF) for protease inhibitors, nonnucleoside reverse transcriptase inhibitors, and an integrase inhibitor by measuring the effect of a range of human serum concentrations on in vitro drug susceptibility measured with the PhenoSense HIV assay. PBCFs corresponding to 100% HS were extrapolated using linear regression and ranged from 1.4 for nevirapine to 77 for nelfinavir. Using the mean 95% inhibitory concentration (IC(95)) for ≥1,200 drug-susceptible viruses, we calculated protein-bound IC(95) (PBIC(95)) values. PBIC(95) values were concordant with the minimum effective C(trough) values that were established in well-designed pharmacodynamic studies (e.g., indinavir, saquinavir, and amprenavir). In other cases, the PBIC(95) values were notably lower (e.g., darunavir, efavirenz, and nevirapine) or higher (nelfinavir and etravirine) than existing target recommendations. The establishment of PBIC(95) values as described here provides a convenient and standardized approach for estimation of the minimum drug exposure that is required to maintain viral suppression and prevent the emergence of drug-resistant variants, particularly when in vivo concentration-response relationships are lacking.

Novel Method To Assess Antiretroviral Target Trough Concentrations Using In Vitro Susceptibility Data

PubMed Central

Limoli, Kay L.; Trinh, Lan; Parkin, Neil T.; King, Jennifer R.; Weidler, Jodi M.; Ofotokun, Ighovwerha; Petropoulos, Christos J.

2012-01-01

Durable suppression of HIV-1 replication requires the establishment of antiretroviral drug concentrations that exceed the susceptibility of the virus strain(s) infecting the patient. Minimum plasma drug concentrations (Ctrough) are correlated with response, but determination of target Ctrough values is hindered by a paucity of in vivo concentration-response data. In the absence of these data, in vitro susceptibility measurements, adjusted for serum protein binding, can provide estimations of suppressive in vivo drug concentrations. We derived serum protein binding correction factors (PBCF) for protease inhibitors, nonnucleoside reverse transcriptase inhibitors, and an integrase inhibitor by measuring the effect of a range of human serum concentrations on in vitro drug susceptibility measured with the PhenoSense HIV assay. PBCFs corresponding to 100% HS were extrapolated using linear regression and ranged from 1.4 for nevirapine to 77 for nelfinavir. Using the mean 95% inhibitory concentration (IC95) for ≥1,200 drug-susceptible viruses, we calculated protein-bound IC95 (PBIC95) values. PBIC95 values were concordant with the minimum effective Ctrough values that were established in well-designed pharmacodynamic studies (e.g., indinavir, saquinavir, and amprenavir). In other cases, the PBIC95 values were notably lower (e.g., darunavir, efavirenz, and nevirapine) or higher (nelfinavir and etravirine) than existing target recommendations. The establishment of PBIC95 values as described here provides a convenient and standardized approach for estimation of the minimum drug exposure that is required to maintain viral suppression and prevent the emergence of drug-resistant variants, particularly when in vivo concentration-response relationships are lacking. PMID:22964257

Distribution and Drug Susceptibility of Candida spp. Associated With Female Genital Tract Infection, Chongqing, China

PubMed Central

Luo, Xiaodong; Dong, Xiaojing; Pen, Zhi

2015-01-01

Background Vulvovaginal candidiasis is defined as vulvovaginitis associated with vaginal carriage of Candida spp. and is a common problem with a high rate of morbidity. Objectives To investigate the distribution of Candida spp. and evaluate the corresponding antifungal susceptibility in women with genital tract infection in Chongqing, southwestern China. Patients and Methods Samples (n = 2.129) were obtained from female patients with symptoms of genital tract infection. Candida spp. were isolated from the specimens and were identified using a coloration medium and the VITEK 2 Compact automatic microbial identification system. Antifungal susceptibility testing was performed using the ATB FUNGUS drug susceptibility testing system. Results From 2,129 samples, 478 (22.45%) isolates of Candida were isolated, of which 395 (82.64%) were Candida albicans, 39 (8.16%) were C. glabrata, 21 (4.39%) were C. tropicalis, 9 (1.88%) were C. parapsilosis, and 14 (2.93%) were other Candida spp. The resistance of C. albicans, C. glabrata, and C. tropicalis to 5 antifungal drugs (amphotericin B, voriconazole, fluconazole, 5-fluorocytosine, and itraconazole) ranged from 0.5% to 6.4%, 0% to 7.7%, and 0% to 9.6%, respectively. Conclusions Candida albicans was the major pathogen associated with candidiasis of the female genital tract in patients in Chongqing. The results of the antifungal sensitivity of the isolates suggest that it is important for clinicians to administer appropriate antifungals for the treatment of Candida spp. infections. PMID:28138369

Clinical efficacy and health implications of inconsistency in different production batches of antimycotic drugs in a developing country.

PubMed

Ogunshe, Adenike A O; Adepoju, Adedayo A; Oladimeji, Modupe E

2011-01-01

This study aimed at evaluating the in vitro efficacy and health implications of inconsistencies in different production batches of antimycotic drugs. in vitro susceptibility profiles of 36 Candida spp. - C. albicans (19.4%), C. glabrata (30.6%), C. tropicalis (33.3%), and C. pseudotropicalis (16.7%) - obtained from human endocervical and high vaginal swabs (ECS/HVS) to two different batches (B1 and B2) of six antimycotic drugs (clotrimazole, doxycycline, iconazole, itraconazole, metronidazole and nystatin) was determined using modified agar well-diffusion method. None of the Candida strains had entirely the same (100%) susceptibility / resistance profiles in both batches of corresponding antimycotic drugs; while, different multiple antifungal susceptibility (MAS) rates were also recorded in batches 1 and 2 for corresponding antifungals. Only 14.3%, 27.3%, 16.7-33.3%, and 8.3-25.0% of C. albicans, C. glabrata, C. pseudotropicalis, and C. tropicalis strains, respectively, had similar susceptibility/resistance profiles toward coressponding antifungal agents in both batches; while up to 57.1% of C. albicans, 45.5% of C. glabrata, 66.7% of C. pseudotropicalis, and 50.0% of C. tropicalis strains were susceptible to one batch of antifungals but resistant to corresponding antifungals in the second batch. As high as 71.4% (C. albicans), 73.0% (C. glabrata), 50.0% (C. pseudotropicalis), and 66.74% (C. tropicalis) strains had differences of ≥ 10.0 mm among corresponding antimycotic agents. Candida strains exhibited different in vitro susceptibility / resistance patterns toward two batches of corresponding antimycotic agents, which has clinical implications on the efficacy of the drugs and treatment of patients. The findings of the present study will be of benefit in providing additional information in support of submission of drugs for registration to appropriate regulatory agencies.

Clinical efficacy and health implications of inconsistency in different production batches of antimycotic drugs in a developing country

PubMed Central

Ogunshe, Adenike A. O.; Adepoju, Adedayo A.; Oladimeji, Modupe E.

2011-01-01

Objective: This study aimed at evaluating the in vitro efficacy and health implications of inconsistencies in different production batches of antimycotic drugs. Materials and Methods: in vitro susceptibility profiles of 36 Candida spp. – C. albicans (19.4%), C. glabrata (30.6%), C. tropicalis (33.3%), and C. pseudotropicalis (16.7%) – obtained from human endocervical and high vaginal swabs (ECS/HVS) to two different batches (B1 and B2) of six antimycotic drugs (clotrimazole, doxycycline, iconazole, itraconazole, metronidazole and nystatin) was determined using modified agar well-diffusion method. Results: None of the Candida strains had entirely the same (100%) susceptibility / resistance profiles in both batches of corresponding antimycotic drugs; while, different multiple antifungal susceptibility (MAS) rates were also recorded in batches 1 and 2 for corresponding antifungals. Only 14.3%, 27.3%, 16.7-33.3%, and 8.3-25.0% of C. albicans, C. glabrata, C. pseudotropicalis, and C. tropicalis strains, respectively, had similar susceptibility/resistance profiles toward coressponding antifungal agents in both batches; while up to 57.1% of C. albicans, 45.5% of C. glabrata, 66.7% of C. pseudotropicalis, and 50.0% of C. tropicalis strains were susceptible to one batch of antifungals but resistant to corresponding antifungals in the second batch. As high as 71.4% (C. albicans), 73.0% (C. glabrata), 50.0% (C. pseudotropicalis), and 66.74% (C. tropicalis) strains had differences of ≥ 10.0 mm among corresponding antimycotic agents. Conclusions: Candida strains exhibited different in vitro susceptibility / resistance patterns toward two batches of corresponding antimycotic agents, which has clinical implications on the efficacy of the drugs and treatment of patients. The findings of the present study will be of benefit in providing additional information in support of submission of drugs for registration to appropriate regulatory agencies. PMID:21430967

[In vitro synergistic effect of moxifloxacin and amphotericin B combination against Candida strains].

PubMed

Yalçin, Burçe; Kalkanci, Ayşe; Gürelik, Feryal; Fidan, Işil; Kustimur, Semra; Ozdek, Sengül

2010-01-01

Contradictory results such as synergy or indifferent effect, have been reported about the interactions between quinolones and antifungal drugs in different studies. The aim of this study was to investigate the in vitro susceptibilities of Candida spp. to moxifloxacin (MOX) alone and MOX + amphotericin B (AmB) combination. A total of 20 strains were included to the study, of which 19 were clinical isolates (10 Candida albicans, 4 Candida glabrata, 2 Candida parapsilosis, 1 Candida tropicalis, 1 Candida pelliculosa ve 1 Candida sake) and 1 was a standard strain (C. albicans ATCC 90028). In vitro susceptibilities of the strains to MOX with AmB were investigated by broth microdilution method according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI), and in vitro interaction of these drugs were determined by a chequerboard titration method. Minimal inhibitory concentration (MIC) values of Candida spp. for MOX were found > or = 400 microg/ml indicating that MOX, by itself has no antifungal activity. AmB MIC values were found 1 microg/ml in 11 of the clinical isolates, and < or = 0.5 microg/ml in the other 8 clinical isolates and 1 standard strain. The inhibitor activity of AmB was slightly enhanced when combined with MOX, there being a decrease of 1-4 fold dilutions in the AmB MICs against all isolates tested. Synergistic effect between MOX and AmB, defined as a fractional inhibitory concentration (FIC) index as < or = 0.5, was observed in 90% (18/20; all were clinical isolates) of the strains, whereas indifferent effect (FIC = 1) was detected in 10% (2/20; 1 was clinical and 1 was standard strain) of the strains. Antagonistic effect was not observed for this combination even at 48th hours. It was concluded that these preliminary results should be confirmed by large-scaled in vitro and in vivo studies to evaluate MOX + AmB combination as a therapeutic option for the treatment of Candida infections.

8-Amido-Bearing pseudomycin B (PSB) analogue: novel antifungal agents.

PubMed

Zhang, Y Z; Sun, X; Zeckner, D J; Sachs, R K; Current, W L; Chen, S H

2001-01-22

During the course of a structure-activity relationship (SAR) study on novel depsinonapeptide pseudomycin B, we synthesized a total of 12 8-amidopseudomycin analogues via standard two-step sequence from either ZPSB 2 or AllocPSB 3. A number of these amides exhibited good in vitro antifungal activities.

Use of the VITEK 2 system to identify and test the antifungal susceptibility of clinically relevant yeast species

PubMed Central

Melhem, MSC; Bertoletti, A; Lucca, HRL; Silva, RBO; Meneghin, FA; Szeszs, MW

2013-01-01

Eleven quality control isolates (Candida albicans ATCC 64548, C. tropicalis ATCC 200956, C. glabrata ATCC 90030, C. lusitaniae ATCC 200951, C. parapsilosis ATCC 22019, C. krusei ATCC 6258, C. dubliniensis ATCC 6330, Saccharomyces cerevisiae ATCC 9763, Cryptococcus neoformans ATCC 90012, C. gattii FIOCRUZ-CPF 60, and Trichosporon mucoides ATCC 204094) and 32 bloodstream isolates, including C. albicans, C. tropicalis, C. parapsilosis, C. glabrata, C. krusei, C. guilliermondii, C. pelliculosa (Pichia anomala), C. haemulonii, C. lusitaniae, and C. kefyr were identified at the species level by the VITEK 2 system. A set of clinical isolates (32 total) were used as challenge strains to evaluate the ability of the VITEK 2 system to determine the antifungal susceptibility of yeasts compared with the CLSI and EUCAST BMD reference standards. The VITEK 2 system correctly identified 100% of the challenge strains. The identification of yeast species and the evaluation of their susceptibility profiles were performed in an automated manner by the VITEK 2 system after approximately 15 h of growth for most species of Candida. The VITEK 2 system ensures that each test is performed in a standardized manner and provides quantitative MIC results that are reproducible and accurate when compared with the BMD reference methods. This system was able to determine the MICs of amphotericin B, flucytosine, voriconazole, and fluconazole in 15 h or less for the most common clinically relevant Candida species. In addition, the VITEK 2 system could reliably identify resistance to flucytosine, voriconazole, and fluconazole and exhibits excellent quantitative and qualitative agreement with the CLSI or EUCAST broth microdilution reference methods. PMID:24688520

Antifungal polypeptides

DOEpatents

Altier, Daniel J [Waukee, IA; Ellanskaya, Irina [Kyiv, UA; Ellanskaya, legal representative, Natalia; Gilliam, Jacob T [Norwalk, IA; Hunter-Cevera, Jennie [Elliott City, MD; Presnail, James K [Avondale, PA; Schepers, Eric [Port Deposit, MD; Simmons, Carl R [Des Moines, IA; Torok, Tamas [Richmond, CA; Yalpani, Nasser [Johnston, IA

2009-09-15

The invention relates to antifungal compositions and methods for protecting a plant from a fungal pathogen. Compositions including antifungal polypeptides isolated from a fungal fermentation broth are provided.

Development of a phosphorylated Momordica charantia protein system for inhibiting susceptible dose-dependent C. albicans to available antimycotics: An allosteric regulation of protein.

PubMed

Qiao, Yuanbiao; Song, Li; Zhu, Chenchen; Wang, Qian; Guo, Tianyan; Yan, Yanhua; Li, Qingshan

2017-11-15

A regulatory Momordica charantia protein system was constructed allosterically by in vitro protein phosphorylation, in an attempt to evaluate antimycological pluripotency against dose-dependent susceptibilities in C. albicans. Fungal strain lineages susceptible to ketoconazole, econazole, miconazole, 5-flucytosine, nystatin and amphotericin B were prepared in laboratory, followed by identification via antifungal susceptibility testing. Protein phosphorylation was carried out in reactions with 5'-adenylic, guanidylic, cytidylic and uridylic acids and cyclic adenosine triphosphate, through catalysis of cyclin-dependent kinase 1, protein kinase A and protein kinase C respectively. Biochemical analysis of enzymatic reactions indicated the apparent Michaelis-Menten constants and maximal velocity values of 16.57-91.97mM and 55.56-208.33μM·min -1 , together with an approximate 1:1 reactant stoichiometric ratio. Three major protein phosphorylation sites were theoretically predicted at Thr255, Thr102 and Thr24 by a KinasePhos tool. Additionally, circular dichroism spectroscopy demonstrated that upon phosphorylation, protein folding structures were decreased in random coil, β6-sheet and α1-helix partial regions. McFarland equivalence standard testing yielded the concentration-dependent inhibition patterns, while fungus was grown in Sabouraud's dextrose agar. The minimal inhibitory concentrations of 0.16-0.51μM (at 50% response) were obtained for free protein and phosphorylated counterparts. With respect to the 3-cycling susceptibility testing regimen, individuals of total protein forms were administrated in-turn at 0.14μM/cycle. Relative inhibition ratios were retained to 66.13-81.04% of initial ones regarding the ketoconazole-susceptible C. albicans growth. An inhibitory protein system, with an advantage of decreasing antifungal susceptibilities to diverse antimycotics, was proposed because of regulatory pluripotency whereas little contribution to susceptibility in

Antifungal Activity of Eupolauridine and Its Action on DNA Topoisomerases

PubMed Central

Khan, Shabana I.; Nimrod, Alison C.; Mehrpooya, Mohammed; Nitiss, John L.; Walker, Larry A.; Clark, Alice M.

2002-01-01

The azafluoranthene alkaloid eupolauridine has previously been shown to have in vitro antifungal activity and selective inhibition of fungal topoisomerase I. The present study was undertaken to examine further its selectivity and mode of action. Eupolauridine completely inhibits the DNA relaxation activity of purified fungal topoisomerase I at 50 μg/ml, but it does not stabilize the cleavage complex of either human or fungal topoisomerase I. Cleavage complex stabilization is the mode of action of topoisomerase I targeting drugs of the camptothecin family. Also, unlike camptothecin, eupolauridine does not cause significant cytotoxicity in mammalian cells. To determine if the inhibition of topoisomerase I is the principal mode of antifungal action of eupolauridine, Saccharomyces cerevisiae strains with alterations in topoisomerase genes were used in clonogenic assays. The antifungal activity of eupolauridine was not diminished in the absence of topoisomerase I; rather, the cells lacking the enzyme were more sensitive to the drug. Cell-killing activity of eupolauridine was also more pronounced in cells that overexpressed topoisomerase II. In vitro assays with the purified yeast enzyme confirmed that eupolauridine stabilized topoisomerase II covalent complexes. These results indicate that a major target for fungal cell killing by eupolauridine is DNA topoisomerase II rather than topoisomerase I, but does not exclude the possibility that the drug also acts against other targets. PMID:12019091

Antifungal activity of eupolauridine and its action on DNA topoisomerases.

PubMed

Khan, Shabana I; Nimrod, Alison C; Mehrpooya, Mohammed; Nitiss, John L; Walker, Larry A; Clark, Alice M

2002-06-01

The azafluoranthene alkaloid eupolauridine has previously been shown to have in vitro antifungal activity and selective inhibition of fungal topoisomerase I. The present study was undertaken to examine further its selectivity and mode of action. Eupolauridine completely inhibits the DNA relaxation activity of purified fungal topoisomerase I at 50 microg/ml, but it does not stabilize the cleavage complex of either human or fungal topoisomerase I. Cleavage complex stabilization is the mode of action of topoisomerase I targeting drugs of the camptothecin family. Also, unlike camptothecin, eupolauridine does not cause significant cytotoxicity in mammalian cells. To determine if the inhibition of topoisomerase I is the principal mode of antifungal action of eupolauridine, Saccharomyces cerevisiae strains with alterations in topoisomerase genes were used in clonogenic assays. The antifungal activity of eupolauridine was not diminished in the absence of topoisomerase I; rather, the cells lacking the enzyme were more sensitive to the drug. Cell-killing activity of eupolauridine was also more pronounced in cells that overexpressed topoisomerase II. In vitro assays with the purified yeast enzyme confirmed that eupolauridine stabilized topoisomerase II covalent complexes. These results indicate that a major target for fungal cell killing by eupolauridine is DNA topoisomerase II rather than topoisomerase I, but does not exclude the possibility that the drug also acts against other targets.

In Vitro Antibiotic Susceptibilities of Burkholderia mallei (Causative Agent of Glanders) Determined by Broth Microdilution and E-Test

PubMed Central

Heine, Henry S.; England, Marilyn J.; Waag, David M.; Byrne, W. Russell

2001-01-01

In vitro susceptibilities to 28 antibiotics were determined for 11 strains of Burkholderia mallei by the broth microdilution method. The B. mallei strains demonstrated susceptibility to aminoglycosides, macrolides, quinolones, doxycycline, piperacillin, ceftazidime, and imipenem. For comparison and evaluation, 17 antibiotic susceptibilities were also determined by the E-test. E-test values were always lower than the broth dilution values. Establishing and comparing antibiotic susceptibilities of specific B. mallei strains will provide reference information for assessing new antibiotic agents. PMID:11408233

Antifungal activity of diketopiperazines and stilbenes against plant pathogenic fungi in vitro.

PubMed

Kumar, S Nishanth; Nambisan, Bala

2014-01-01

The present study aimed to investigate antifungal activity of a stilbene and diketopiperazine compounds against plant pathogenic fungi, including Phytophthora capsici, P. colocasiae, Botrytis cinerea and Colletotrichum gloeosporioides. Minimal inhibition concentrations (MIC) and minimal fungicidal concentrations (MFC) of stilbenes and diketopiperazines for each fungus were determined using microplate method. Best activity was recorded by stilbenes against P. capsici and P. colocasiae. All four test compounds were effective in inhibiting different stages of the life cycle of test fungi. Stilbenes were more effective than diketopiperazines in inhibiting mycelial growth and inhibiting different stages of the life cycle of P. capsici and P. colocasiae. Rupture of released zoospores induced by stilbenes was reduced by addition of 100 mM glucose. The effects of stilbenes on mycelial growth and zoospore release, but not zoospore rupture, were reduced largely when pH value was above 7. In addition, stilbenes were investigated for its antifungal stability against Phytophthora sp. The results showed that stilbenes maintained strong fungistatic activity over a wide pH range (pH 4–9) and temperature range (70–120 °C). The compound stilbenes exhibited strong and stable broad-spectrum antifungal activity, and had a significant fungicidal effect on fungal cells. Results from prebiocontrol evaluations performed to date are probably useful in the search for alternative approaches to controlling serious plant pathogens.

[Susceptibility to azoles and amphotericin B of isolates of Candida spp. Experience of a university health network, between 2004 and 2010].

PubMed

Porte, Lorena; León, Pilar; Gárate, Cynthia; Guzmán, Ana María; Labarca, Jaime; García, Patricia

2012-04-01

To describe antifungal susceptibility testing surveillance (December 2004-September 2010) in Candida spp., for amphotericin B, fluconazole and voriconazole, at the Laboratorio de Microbiología, Pontificia Universidad Católica de Chile. The study was performed utilizing E test and included yeasts from invasive origin and isolates in which antifungal susceptibility testing was asked for by the patient's physician. The yeasts were mainly recovered from urine samples (n: 64), blood cultures (n: 51) and secretions (n: 24). Two hundred ninety three isolates were studied: C. albicans (38%), C. glabrata (30%), C. tropicalis (11%), C. parapsilosis (10%), C. krusei (4%) and others (7%). All Candida species were 100% susceptible to amphotericin B, except C. krusei (1/12). Fluconazole's global susceptibility in C. albicans was 91.8%, but 100% in isolates from blood cultures versus 76% in isolates from urine. C. tropicalis was 93.9% susceptible to fluconazole, C. parapsilosis, 90% and C. glabrata 30.3%. C. krusei had no susceptible isolates to fluconazole. Voriconazole resistance was mainly present in C. glabrata (11.5%). We recommend the study of antifungal susceptibility in isolates from invasive origin, selected urine strains and C. glabrata. Fluconazole remains effective in C. albicans from blood.

Fungal and Bacterial Infection Mitigation with Antibiotic and Antifungal Loaded Biopolymer Sponges

NASA Astrophysics Data System (ADS)

Parker, Ashley Cox

Musculoskeletal injuries are some of the most prevalent injuries in both civilian and military populations and their infections can be difficult to treat, often resulting in multiple surgeries and increased costs. In both previous and recent military operations, extremity injuries have been the most common battlefield injuries and many involve complex, open fractures. These extremity injuries are especially susceptible to multiple pathogenic, and sometimes drug resistant, bacteria and fungi. Fungal infections have recently become increasingly problematic in both military and civilian populations and have significantly higher amputation rates than those from bacterial infections. Many of these bacterial and fungal strains adhere to tissue and implanted orthopaedic hardware within wounds, forming biofilms. These problematic, often polymicrobial, infections threaten the health of the patient, but the risk also exists of spreading within hospitals to become prominent resistant infections. Local antimicrobial delivery releases high levels of antimicrobials directly to injured wound tissue, overcoming sub-bactericidal or subfungicidal antimicrobial levels present in the avascular wound zones. This research will determine the ability of modified chitosan sponges, buffered with sodium acetate or blended with polyethylene glycol (PEG), to act as short term adjunctive therapies to initial surgical treatment for delivering both antibiotics and/or antifungals for early abatement of infection. The objective of this work was to evaluate both types of modified sponges for in vitro and in vivo material characteristics and device functionality. In vitro analysis demonstrated both the buffered and PEG modified chitosan sponges exhibited increased degradation and functional cytocompatibility. The chitosan/PEG sponges were able to be loaded with hydrophobic antifungals and the sponges released in vitro biologically active concentrations, alone or in combination with the antibiotic

Design, synthesis of novel chitosan derivatives bearing quaternary phosphonium salts and evaluation of antifungal activity.

PubMed

Tan, Wenqiang; Zhang, Jingjing; Luan, Fang; Wei, Lijie; Chen, Yuan; Dong, Fang; Li, Qing; Guo, Zhanyong

2017-09-01

Two novel chitosan derivatives modified with quaternary phosphonium salts were successfully synthesized, including tricyclohexylphosphonium acetyl chitosan chloride (TCPACSC) and triphenylphosphonium acetyl chitosan chloride (TPPACSC), and characterized by FTIR, 1 H NMR, and 13 C NMR spectra. The degree of substitution was also calculated by elemental analysis results. Their antifungal activities against Colletotrichum lagenarium, Watermelon fusarium, and Fusarium oxysporum were investigated in vitro using the radial growth assay, minimal inhibitory concentration, and minimum bactericidal concentration assay. The fungicidal assessment revealed that the synthesized chitosan derivatives had superior antifungal activity compared with chitosan. Especially, TPPACSC exhibited the best antifungal property with inhibitory indices of over 75% at 1.0mg/mL. The results obviously showed that quaternary phosphonium groups could effectively enhance antifungal activity of the synthesized chitosan derivatives. Meanwhile, it was also found that their antifungal activity was influenced by electron-withdrawing ability of the quaternary phosphonium salts. The synthetic strategy described here could be utilized for the development of chitosan as antifungal biomaterials. Copyright © 2017 Elsevier B.V. All rights reserved.

Expression in Escherichia coli, purification, refolding and antifungal activity of an osmotin from Solanum nigrum

PubMed Central

Campos, Magnólia de A; Silva, Marilia S; Magalhães, Cláudio P; Ribeiro, Simone G; Sarto, Rafael PD; Vieira, Eduardo A; Grossi de Sá, Maria F

2008-01-01

Background Heterologous protein expression in microorganisms may contribute to identify and demonstrate antifungal activity of novel proteins. The Solanum nigrum osmotin-like protein (SnOLP) gene encodes a member of pathogenesis-related (PR) proteins, from the PR-5 sub-group, the last comprising several proteins with different functions, including antifungal activity. Based on deduced amino acid sequence of SnOLP, computer modeling produced a tertiary structure which is indicative of antifungal activity. Results To validate the potential antifungal activity of SnOLP, a hexahistidine-tagged mature SnOLP form was overexpressed in Escherichia coli M15 strain carried out by a pQE30 vector construction. The urea solubilized His6-tagged mature SnOLP protein was affinity-purified by immobilized-metal (Ni2+) affinity column chromatography. As SnOLP requires the correct formation of eight disulfide bonds, not correctly formed in bacterial cells, we adapted an in vitro method to refold the E. coli expressed SnOLP by using reduced:oxidized gluthatione redox buffer. This method generated biologically active conformations of the recombinant mature SnOLP, which exerted antifungal action towards plant pathogenic fungi (Fusarium solani f. sp.glycines, Colletotrichum spp., Macrophomina phaseolina) and oomycete (Phytophthora nicotiana var. parasitica) under in vitro conditions. Conclusion Since SnOLP displays activity against economically important plant pathogenic fungi and oomycete, it represents a novel PR-5 protein with promising utility for biotechnological applications. PMID:18334031

A novel 96-well gel-based assay for determining antifungal activity against filamentous fungi.

PubMed

Troskie, Anscha Mari; Vlok, Nicolas Maré; Rautenbach, Marina

2012-12-01

In recent years the global rise in antibiotic resistance and environmental consciousness lead to a renewed fervour to find and develop novel antibiotics, including antifungals. However, the influence of the environment on antifungal activity is often disregarded and many in vitro assays may cause the activity of certain antifungals to be overestimated or underestimated. The general antifungal test assays that are economically accessible to the majority of scientists primarily rely on visual examination or on spectrophotometric analysis. The effect of certain morphogenic antifungals, which may lead to hyperbranching of filamentous fungi, unfortunately renders these methods unreliable. To minimise the difficulties experienced as a result of hyperbranching, we developed a straightforward, economical 96-well gel-based method, independent of spectrophotometric analysis, for highly repeatable determination of antifungal activity. For the calculation of inhibition parameters, this method relies on the visualisation of assay results by digitisation. The antifungal activity results from our novel micro-gel dilution assay are comparable to that of the micro-broth dilution assay used as standard reference test of The Clinical and Laboratory Standard Institute. Furthermore, our economical assay is multifunctional as it permits microscopic analysis of the preserved assay results, as well as rendering highly reliable data. Copyright © 2012 Elsevier B.V. All rights reserved.

In Vitro Activities of 35 Double Combinations of Antifungal Agents against Scedosporium apiospermum and Scedosporium prolificans▿

PubMed Central

Cuenca-Estrella, Manuel; Alastruey-Izquierdo, Ana; Alcazar-Fuoli, Laura; Bernal-Martinez, Leticia; Gomez-Lopez, Alicia; Buitrago, Maria J.; Mellado, Emilia; Rodriguez-Tudela, Juan L.

2008-01-01

Activities of 35 combinations of antifungal agents against Scedosporium spp. were analyzed by a checkerboard microdilution design and the summation of fractional concentration index. An average indifferent effect was detected apart from combinations of azole agents and echinocandins against Scedosporium apiospermum. Antagonism was absent for all antifungal combinations against both species. PMID:18195067

Determination of antifungal activities in serum samples from mice treated with different antifungal drugs allows detection of an active metabolite of itraconazole.

PubMed

Maki, Katsuyuki; Watabe, Etsuko; Iguchi, Yumi; Nakamura, Hideko; Tomishima, Masaki; Ohki, Hidenori; Yamada, Akira; Matsumoto, Satoru; Ikeda, Fumiaki; Tawara, Shuichi; Mutoh, Seitaro

2006-01-01

To establish an in vitro method of predicting in vivo efficacy of antifungal drugs against Candida albicans and Aspergillus fumigatus, the antifungal activities of fluconazole, itraconazole, and amphotericin B were determined in mouse serum. The minimum inhibitory concentration (MIC) of each drug was measured using mouse serum as a diluent. For C. albicans, the assay endpoint of azoles was defined as inhibition of mycelial extension (mMIC) and for A. fumigatus, as no growth (MIC). The MICs of amphotericin B for both pathogens were defined as the MIC at which no mycelial growth occurred. Serum MIC or mMIC determinations were then used to estimate the concentration of the drugs in serum of mice treated with antifungal drugs by multiplying the antifungal titer of the serum samples by the serum (m)MIC. The serum drug concentrations were also determined by HPLC. The serum concentrations estimated microbiologically showed good agreement with those determined by HPLC, except for itraconazole. Analysis of the serum samples from itraconazole-treated mice by a sensitive bioautography revealed the presence of additional spots, not seen in control samples of itraconazole. The bioautography assay demonstrated that the additional material detected in serum from mice treated with itraconazole was an active metabolite of itraconazole. The data showed that the apparent reduction in the itraconazole serum concentration as determined by HPLC was the result of the formation of an active metabolite, and that the use of a microbiological method to measure serum concentrations of drugs can provide a method for prediction of in vivo efficacy of antifungal drugs.

Overcoming antifungal resistance

PubMed Central

Srinivasan, Anand; Lopez-Ribot, Jose L.; Ramasubramanian, Anand K.

2014-01-01

Fungal infections have become one of the major causes of morbidity and mortality in immunocompromised patients. Despite increased awareness and improved treatment strategies, the frequent development of resistance to the antifungal drugs used in clinical settings contributes to the increasing toll of mycoses. Although a natural phenomenon, antifungal drug resistance can compromise advances in the development of effective diagnostic techniques and novel antifungals. In this review, we will discuss the advent of cellular-microarrays, microfluidics, genomics, proteomics and other state-of-the art technologies in conquering antifungal drug resistance. PMID:24847655

Antifungal activity of synthetic antiseptics and natural compounds against Candida dubliniensis before and after in vitro fluconazole exposure.

PubMed

Reginato, Cássia Franco; Bandeira, Laíssa Arévalo; Zanette, Régis Adriel; Santurio, Janio Morais; Alves, Sydney Hartz; Danesi, Cristiane Cademartori

2017-01-01

This study evaluated the susceptibilities of oral candidiasis-derived Candida albicans, fluconazole-resistant (FR) Candida dubliniensis, and fluconazole-susceptible (FS) C. dubliniensis to synthetic antiseptics [chlorhexidine gluconate (CHX), cetylpyridinium chloride (CPC), and triclosan (TRC)] and natural compounds (carvacrol, eugenol and thymol). Susceptibility tests were performed based on the M27-A3 reference method. The fluconazole-resistant C. dubliniensis strains were obtained after prolonged in vitro exposure to increasing fluconazole concentrations. The geometric mean values for minimum inhibitory concentrations and minimum fungicidal concentrations were compared among the groups. Fluconazole-susceptible C. dubliniensis was more sensitive to CPC and TRC than FR C. dubliniensis and C. albicans were. However, eugenol and thymol were more active against FR C. dubliniensis. The fungicidal activities of CHX and TRC were similar for the three groups, and FR C. dubliniensis and C. albicans had similar sensitivities to CPC. The resistance of C. dubliniensis to fluconazole affects its sensitivity the synthetic antiseptics and natural compounds that were tested.

Genetic diversity of Aspergillus species isolated from onychomycosis and Aspergillus hongkongensis sp. nov., with implications to antifungal susceptibility testing.

PubMed

Tsang, Chi-Ching; Hui, Teresa W S; Lee, Kim-Chung; Chen, Jonathan H K; Ngan, Antonio H Y; Tam, Emily W T; Chan, Jasper F W; Wu, Andrea L; Cheung, Mei; Tse, Brian P H; Wu, Alan K L; Lai, Christopher K C; Tsang, Dominic N C; Que, Tak-Lun; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

2016-02-01

Thirteen Aspergillus isolates recovered from nails of 13 patients (fingernails, n=2; toenails, n=11) with onychomycosis were characterized. Twelve strains were identified by multilocus sequencing as Aspergillus spp. (Aspergillus sydowii [n=4], Aspergillus welwitschiae [n=3], Aspergillus terreus [n=2], Aspergillus flavus [n=1], Aspergillus tubingensis [n=1], and Aspergillus unguis [n=1]). Isolates of A. terreus, A. flavus, and A. unguis were also identifiable by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The 13th isolate (HKU49(T)) possessed unique morphological characteristics different from other Aspergillus spp. Molecular characterization also unambiguously showed that HKU49(T) was distinct from other Aspergillus spp. We propose the novel species Aspergillus hongkongensis to describe this previously unknown fungus. Antifungal susceptibility testing showed most Aspergillus isolates had low MICs against itraconazole and voriconazole, but all Aspergillus isolates had high MICs against fluconazole. A diverse spectrum of Aspergillus species is associated with onychomycosis. Itraconazole and voriconazole are probably better drug options for Aspergillus onychomycosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Essential oil of Psidium cattleianum leaves: antioxidant and antifungal activity.

PubMed

Castro, Micheli R; Victoria, Francine N; Oliveira, Daniela H; Jacob, Raquel G; Savegnago, Lucielli; Alves, Diego

2015-02-01

Psidium cattleianum Sabine (Myrtacea) is rich in vitamin C and phenolic compounds, including epicatechin and gallic acid as the main components. To evaluate the antifungal and antioxidant capacity in vitro of the essential oil of araçá (EOA). The acute toxicity of the EOA also was evaluated in mice. The leaves of the P. cattleianum were extracted by steam distillation. The antioxidant capacity was evaluated by in vitro tests [1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS), ferric ion reducing antioxidant power (FRAP), linoleic acid oxidation, thiobarbituric acid reactive species (TBARS)], and ex vivo analysis [TBARS, δ-aminulevunilate dehydratase (δ-Ala-D) and catalase activity, non-protein thiols (NPSH), and ascorbic acid levels]. The toxicity was studied in mice by a single oral administration of EOA; and the antifungal activity was performed with five strains of fungi. The EOA exhibited antioxidant activity in the FRAP assay and reduced lipid peroxidation in the cortex (Imax = 32.90 ± 2.62%), hippocampus (IC50 = 48.00 ± 3.00 µg/ml and Imax = 32.90 ± 2.62%), and cerebellum (Imax = 45.40 ± 14.04%) of mice. Acute administration of the EOA by the oral route did not cause toxicological effects in mice (LD50 > 500 µg/ml). The EOA also showed antifungal activity through of the determination minimum inhibitory concentration (MIC) values ranging from 41.67 ± 18.04 to 166.70 ± 72.17 µg/ml for tested strains. The results of present study indicate that EOA possess antioxidant properties, antifungal and not cause toxicity at tested doses.

In silico, in vitro and antifungal activity of the surface layers formed on zinc during this biomaterial degradation

NASA Astrophysics Data System (ADS)

Alves, Marta M.; Marques, Luísa M.; Nogueira, Isabel; Santos, Catarina F.; Salazar, Sara B.; Eugénio, Sónia; Mira, Nuno P.; Montemor, M. F.

2018-07-01

Zinc (Zn) has been proposed as an alternative metallic biodegradable material to support transient wound-healing processes. Once a Zn piece is implanted inside the organism the degradation will depend upon the physiological surrounding environment. This, by modulating the composition of the surface layers formed on Zn devices, will govern the subsequent interactions with the surrounding living cells (e.g. biocompatibility and/or antifungal behaviour). In silico simulation of an implanted Zn piece at bone-muscle interface or inside the bone yielded the preferential precipitation of simonkolleite or zincite, respectively. To study the impact of these surface layers in the in vitro behaviour of Zn biomaterials, simonkolleite and zincite where synthesised. The successful production of simonkolleite or zincite was confirmed by an extensive physicochemical characterization. An in vitro layer formed on the top of these surface layers revealed that simonkolleite was rather inert, while zincite yielded a complex matrix containing hydroxyapatite, an important bone analogue. When analysing the "anti-biofilm" activity simonkolleite stood out for its activity against an important pathogenic fungi involved in implant-device infections, Candida albicans. The possible physiological implications of these findings are discussed.

Antifungal activity of acetone extracts from Punica granatum L., Quercus suber L. and Vicia faba L.

PubMed

Akroum, S

2017-03-01

Human and animal mycoses become more frequent and more resistant to traditional treatments. In this work, we tested the in vitro antifungal activity of acetonic extracts of Punica granatum L., Quercus suber L. and Vicia faba L. against seven pathogen fungi and the in vivo antifungal activity against Candida albicans and Trichophyton mentagrophytes. The phytochemical screening was also carried out and showed that the extracts contained mainly proanthocyanidins. Other polyphenols were also present but in low quantity. The acetone extract of V. faba L. gave a good in vitro inhibition of yeasts and was the most active for treating candidiasis in mice. It decreased the percentage of mortality with only 20μg. But the in vivo antifungal activity of this extract on T. mentagrophytes was low. It only showed a small diminution of crusting and erythema after the administration of 100μg. On the contrary, the acetone extracts of P. granatum L. had a poor activity against yeasts and a better one against moulds. It gave the best in vivo antifungal activity against T. mentagrophytes by healing animals with 40μg. The extract of P. granatum L. gave also an interesting in vivo antifungal activity against T. mentagrophytes with an active dose of 80μg. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Synthesis and in vitro antifungal efficacy of oleoyl-chitosan nanoparticles against plant pathogenic fungi.

PubMed

Xing, Ke; Shen, Xiaoqiang; Zhu, Xiao; Ju, Xiuyun; Miao, Xiangmin; Tian, Jun; Feng, Zhaozhong; Peng, Xue; Jiang, Jihong; Qin, Sheng

2016-01-01

An antifungal dispersion system was prepared by oleoyl-chitosan (O-chitosan) nanoparticles, and the antifungal activity against several plant pathogenic fungi was investigated. Under scanning electron microscopy, the nanoparticles formulation appeared to be uniform with almost spherical shape. The particle size of nanoparticles was around 296.962 nm. Transmission electron microscopy observation showed that nanoparticles could be well distributed in potato dextrose agar medium. Mycelium growth experiment demonstrated that Nigrospora sphaerica, Botryosphaeria dothidea, Nigrospora oryzae and Alternaria tenuissima were chitosan-sensitive, while Gibberella zeae and Fusarium culmorum were chitosan-resistant. The antifungal index was increased as the concentration of nanoparticles increased for chitosan-sensitive fungi. Fatty acid analyses revealed that plasma membranes of chitosan-sensitive fungi were shown to have lower levels of unsaturated fatty acid than chitosan-resistant fungi. Phylogenetic analysis based on ITS gene sequences indicated that two chitosan-resistant fungi had a near phylogenetic relationship. Results showed that O-chitosan nanoparticles could be a useful alternative for controlling pathogenic fungi in agriculture. Copyright © 2015 Elsevier B.V. All rights reserved.

In Vitro Antifungal Activity of Burkholderia gladioli pv. agaricicola against Some Phytopathogenic Fungi

PubMed Central

Elshafie, Hazem S.; Camele, Ippolito; Racioppi, Rocco; Scrano, Laura; Iacobellis, Nicola S.; Bufo, Sabino A.

2012-01-01

The trend to search novel microbial natural biocides has recently been increasing in order to avoid the environmental pollution from use of synthetic pesticides. Among these novel natural biocides are the bioactive secondary metabolites of Burkholderia gladioli pv. agaricicola (Bga). The aim of this study is to determine antifungal activity of Bga strains against some phytopathogenic fungi. The fungicidal tests were carried out using cultures and cell-free culture filtrates against Botrytis cinerea, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, Sclerotinia sclerotiorum and Phytophthora cactorum. Results demonstrated that all tested strains exert antifungal activity against all studied fungi by producing diffusible metabolites which are correlated with their ability to produce extracellular hydrolytic enzymes. All strains significantly reduced the growth of studied fungi and the bacterial cells were more bioactive than bacterial filtrates. All tested Bulkholderia strains produced volatile organic compounds (VOCs), which inhibited the fungal growth and reduced the growth rate of Fusarium oxysporum and Rhizoctonia solani. GC/MS analysis of VOCs emitted by strain Bga 11096 indicated the presence of a compound that was identified as 1-methyl-4-(1-methylethenyl)-cyclohexene, a liquid hydrocarbon classified as cyclic terpene. This compound could be responsible for the antifungal activity, which is also in agreement with the work of other authors. PMID:23208371

Multicenter Comparison of the Etest and EUCAST Methods for Antifungal Susceptibility Testing of Candida Isolates to Micafungin

PubMed Central

Bougnoux, M.-E.; Accoceberry, I.; Angoulvant, A.; Bailly, E.; Botterel, F.; Chevrier, S.; Chouaki, T.; Dalle, F.; Datry, A.; Dupuis, A.; Fekkar, A.; Gangneux, J. P.; Guitard, J.; Hennequin, C.; Le Govic, Y.; Le Pape, P.; Maubon, D.; Sautour, M.; Sendid, B.; Chandenier, J.

2016-01-01

In vitro susceptibility of 933 Candida isolates, from 16 French hospitals, to micafungin was determined using the Etest in each center. All isolates were then sent to a single center for determination of MICs by the EUCAST reference method. Overall essential agreement between the two tests was 98.5% at ±2 log2 dilutions and 90.2% at ±1 log2 dilutions. Categorical agreement was 98.2%. The Etest is a valuable alternative to EUCAST for the routine determination of micafungin MICs in medical mycology laboratories. PMID:27297480

Candida glabrata species complex prevalence and antifungal susceptibility testing in a culture collection: First description of Candida nivariensis in Argentina.

PubMed

Morales-López, Soraya Eugenia; Taverna, Constanza G; Bosco-Borgeat, María Eugenia; Maldonado, Ivana; Vivot, Walter; Szusz, Wanda; Garcia-Effron, Guillermo; Córdoba, Susana B

2016-12-01

The presence of the cryptic species belonging to the Candida glabrata complex has not been studied in Argentina. We analyzed a collection of 117 clinical isolates of C. glabrata complex belonging to a National Culture Collection of Instituto Nacional de Microbiología "Dr. Carlos G. Malbrán" from Argentina (40 isolates from blood samples, 18 from other normally sterile sites, 20 from vagina, 14 from urine, 7 from oral cavity, 3 from catheter, 1 from a stool sample and 14 isolates whose clinical origin was not recorded). The aims of this work were to determine the prevalence of the cryptic species Candida nivariensis and Candida bracarensis and to evaluate the susceptibility profile of isolates against nine antifungal drugs. Identification was carried out by using classical phenotypic tests, CHROMagar™ Candida, PCR and MALDI-TOF. The minimal inhibitory concentrations of amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, voriconazole, ketoconazole, posaconazole, caspofungin and anidulafungin were determined according to the EDef 7.3 (EUCAST) reference document. Of the 117 isolates, 114 were identified as C. glabrata and three as C. nivariensis by using PCR and MALDI-TOF. There were no major differences between C. nivariensis and C. glabrata susceptibility profiles. No resistant strains were found to echinocandins. We have found that the percentage of C. nivariensis in our culture collection was 2.56. This is the first description of C. nivariensis in Argentina, and data obtained could contribute to the knowledge of the epidemiology of this cryptic species.

Syntheses of new rare earth complexes with carboxymethylated polysaccharides and evaluation of their in vitro antifungal activities.

PubMed

Sun, Xiaobo; Jin, Xiaozhe; Pan, Wei; Wang, Jinping

2014-11-26

In the present paper, La, Eu and Yb were selected to represent light, middle and heavy rare earths to form complexes with polysaccharides through chelating coordination of carboxyl groups, which were added into polysaccharide chains by means of carboxymethylation. Their antifungal activities against plant pathogenic fungi were evaluated using growth rate method. These rare earth complexes exhibited various antifungal activities against the tested fungi, depending on rare earth elements, polysaccharide types and fungal species. Among these three metal elements (i.e. La, Eu and Yb), Yb formed the complexes with the most effective antifungal properties. Furthermore, the results showed that ligands of carboxymethylated polysaccharides played a key role in promoting cytotoxicity of the rare earth complexes. Carboxymethylated Ganoderma applanatum polysaccharide (CGAP) was found to be the most effective ligand to form complexes with antifungal activities, followed by carboxymethylated lentinan (CLNT) and carboxymethylated Momordica charantia polysaccharide (CMCP). Copyright © 2014 Elsevier Ltd. All rights reserved.

Essential oil composition, antioxidant and antifungal activities of Salvia sclarea L. from Munzur Valley in Tunceli, Turkey.

PubMed

Yuce, E; Yildirim, N; Yildirim, N C; Paksoy, M Y; Bagci, E

2014-06-15

The essential oil composition and in vitro antioxidant and antifungal activity of the Salvia sclarea L. from Munzur Valley in Tunceli, Turkey were evaluated in this research. The in vitro antifungal activity of ethanol, hexane and aqueous extracts of S. sclarea against pathogen fungi Epicoccum nigrum and Colletotrichum coccodes were investigated. The essential oil of aerial parts of S. sclarea was obtained by hydrodistillation and was analysed by GC and GC—MS. Total antioxidant status was determined by using Rel assay diagnostics TAS assay kit (Lot.RL024) by Multiscan FC (Thermo). 33 compounds were identified representing the 85.0% of the total oil. The most abundant components (>5%) of the S. sclarea essential oils were caryophyllene oxide (24.1%), sclareol (11.5%), spathulenol (11.4%), 1H-naphtho (2,1,6) pyran (8.6%) and b—caryophyllene (5.1%). The best antifungal and antioxidant effect was seen in ethanolic S. sclarea extract. It can be said that Salvia sclerae could be used as natural antioxidant.

Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp.

PubMed

Moussa, Ahmed; Noureddine, Djebli; Saad, Aissat; Abdelmelek, Meslem; Abdelkader, Benhalima

2012-07-01

To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7-23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09-93.48)% and (4.90-99.70)% v/v, respectively. This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans.

Inhibitors of amino acids biosynthesis as antifungal agents.

PubMed

Jastrzębowska, Kamila; Gabriel, Iwona

2015-02-01

Fungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit growth defect or at least reduced virulence under in vivo conditions. Several chemical compounds inhibiting activity of one of these enzymes exhibit good antifungal in vitro activity in minimal growth media, which is not always confirmed under in vivo conditions. This article provides a comprehensive overview of the present knowledge on pathways of amino acids biosynthesis in fungi, with a special emphasis put on enzymes catalyzing particular steps of these pathways as potential targets for antifungal chemotherapy.

Antifungal activity of n-tributyltin acetate against some common yam rot fungi.

PubMed Central

Olurinola, P F; Ehinmidu, J O; Bonire, J J

1992-01-01

The antifungal activity of n-tributyltin acetate (TBTA) was examined in relation to combating yam rot disease. TBTA exhibited a significant effect in vitro and in vivo on four yam rot fungal isolates tested. However, the in vitro toxicity of TBTA was drastically reduced when 2.5% Tween 80 was the solvent instead of 25% acetone, as indicated by the MICs of 156.0 and 5.0 micrograms/ml, respectively. PMID:1610202

Fungal CYP51 Inhibitors VT-1161 and VT-1129 Exhibit Strong In Vitro Activity against Candida glabrata and C. krusei Isolates Clinically Resistant to Azole and Echinocandin Antifungal Compounds.

PubMed

Schell, W A; Jones, A M; Garvey, E P; Hoekstra, W J; Schotzinger, R J; Alexander, B D

2017-03-01

The in vitro activities of fungal CYP51 inhibitors VT-1161 and VT-1129 were determined for Candida glabrata ( n = 34) and C. krusei ( n = 50). C. glabrata isolates were screened for FKS gene mutations. All isolates were resistant clinically and/or in vitro to at least one standard antifungal compound. VT-1161 and VT-1129 MICs for all isolates were at least 5-fold below achievable human plasma levels for VT-1161. VT-1161 and VT-1129 are promising for the treatment of resistant C. glabrata and C. krusei infections. Copyright © 2017 American Society for Microbiology.

Etest and Sensititre YeastOne Susceptibility Testing of Echinocandins against Candida Species from a Single Center in Austria.

PubMed

Aigner, Maria; Erbeznik, Thomas; Gschwentner, Martin; Lass-Flörl, Cornelia

2017-08-01

Candida species were tested for susceptibility to caspofungin, anidulafungin, and micafungin in order to evaluate the roles of Etest and Sensititre YeastOne in antifungal susceptibility testing for daily routines and to survey resistance. A total of 104 Candida species isolates detected from blood cultures were investigated. With EUCAST broth microdilution as the reference method, essential agreement (EA), categorical agreement (CA), very major errors (VME), major errors (ME), and minor (MIN) errors were assessed by reading MICs at 18, 24, and 48 h. By use of EUCAST broth microdilution and species-specific clinical breakpoints (CBPs), echinocandin resistance was not detected during the study period. Using EUCAST CBPs, MIC readings at 24 h for the Etest and Sensititre YeastOne resulted in CA levels of 99% and 93% for anidulafungin and 99% and 97% for micafungin. Using revised CLSI CBPs for caspofungin, CA levels were 92% and 99% for Etest and Sensititre YeastOne. The Etest proved an excellent, easy-to-handle alternative method for testing susceptibility to anidulafungin and micafungin. Due to misclassifications, the Etest is less suitable for testing susceptibility to caspofungin (8% of isolates falsely tested resistant). The CA levels of Sensititre YeastOne were 93% and 97% for anidulafungin and micafungin (24 h) by use of EUCAST CBPs and increased to 100% for both antifungals if CLSI CBPs were applied and to 100% and 99% if Sensititre YeastOne epidemiological cutoff values (ECOFFs) were applied. No one echinocandin could be demonstrated to be superior to another in vitro Since resistance was lacking among our Candida isolates, we cannot derive any recommendation from accurate resistance detection by the Etest and Sensititre YeastOne. Copyright © 2017 American Society for Microbiology.

[A study for testing the antifungal susceptibility of yeast by the Japanese Society for Medical Mycology (JSMM) method. The proposal of the modified JSMM method 2009].

PubMed

Nishiyama, Yayoi; Abe, Michiko; Ikeda, Reiko; Uno, Jun; Oguri, Toyoko; Shibuya, Kazutoshi; Maesaki, Shigefumi; Mohri, Shinobu; Yamada, Tsuyoshi; Ishibashi, Hiroko; Hasumi, Yayoi; Abe, Shigeru

2010-01-01

The Japanese Society for Medical Mycology (JSMM) method used for testing the antifungal susceptibility of yeast, the MIC end point for azole antifungal agents, is currently set at IC(80). It was recently shown, however that there is an inconsistency in the MIC value between the JSMM method and the CLSI M27-A2 (CLSI) method, in which the end- point was to read as IC(50). To resolve this discrepancy and reassess the JSMM method, the MIC for three azoles, fluconazole, itraconazole and voriconazole were compared to 5 strains of each of the following Candida species: C. albicans, C. glabrata, C. tropicalis, C. parapsilosis and C. krusei, for a total of 25 comparisons, using the JSMM method, a modified JSMM method, and the CLSI method. The results showed that when the MIC end- point criterion of the JSMM method was changed from IC(80) to IC(50) (the modified JSMM method) , the MIC value was consistent and compatible with the CLSI method. Finally, it should be emphasized that the JSMM method, using a spectrophotometer for MIC measurement, was superior in both stability and reproducibility, as compared to the CLSI method in which growth was assessed by visual observation.

Modulating effects of plasma containing anti-malarial antibodies on in vitro anti-malarial drug susceptibility in Plasmodium falciparum.

PubMed

Monatrakul, Preeyaporn; Mungthin, Mathirut; Dondorp, Arjen M; Krudsood, Srivicha; Udomsangpetch, Rachanee; Wilairatana, Polrat; White, Nicholas J; Chotivanich, Kesinee

2010-11-16

The efficacy of anti-malarial drugs is determined by the level of parasite susceptibility, anti-malarial drug bioavailability and pharmacokinetics, and host factors including immunity. Host immunity improves the in vivo therapeutic efficacy of anti-malarial drugs, but the mechanism and magnitude of this effect has not been characterized. This study characterized the effects of 'immune' plasma to Plasmodium falciparumon the in vitro susceptibility of P. falciparum to anti-malarial drugs. Titres of antibodies against blood stage antigens (mainly the ring-infected erythrocyte surface antigen [RESA]) were measured in plasma samples obtained from Thai patients with acute falciparum malaria. 'Immune' plasma was selected and its effects on in vitro parasite growth and multiplication of the Thai P. falciparum laboratory strain TM267 were assessed by light microscopy. The in vitro susceptibility to quinine and artesunate was then determined in the presence and absence of 'immune' plasma using the 3H-hypoxanthine uptake inhibition method. Drug susceptibility was expressed as the concentrations causing 50% and 90% inhibition (IC50 and IC90), of 3H-hypoxanthine uptake. Incubation with 'immune' plasma reduced parasite maturation and decreased parasite multiplication in a dose dependent manner. 3H-hypoxanthine incorporation after incubation with 'immune' plasma was decreased significantly compared to controls (median [range]; 181.5 [0 to 3,269] cpm versus 1,222.5 [388 to 5,932] cpm) (p= 0.001). As a result 'immune' plasma reduced apparent susceptibility to quinine substantially; median (range) IC50 6.4 (0.5 to 23.8) ng/ml versus 221.5 (174.4 to 250.4) ng/ml (p = 0.02), and also had a borderline effect on artesunate susceptibility; IC50 0.2 (0.02 to 0.3) ng/ml versus 0.8 (0.2 to 2.3) ng/ml (p = 0.08). Effects were greatest at low concentrations, changing the shape of the concentration-effect relationship. IC90 values were not significantly affected; median (range) IC90 448.0 (65

Synthesis and antifungal evaluation of (1,2,3-triazol-4-yl)methyl nicotinate chitosan.

PubMed

Qin, Yukun; Liu, Song; Xing, Ronge; Li, Kecheng; Yu, Huahua; Li, Pengcheng

2013-10-01

With an aim to discover novel chitosan derivatives with significant activities against crop-threatening fungi, (1,2,3-triazol-4-yl)methyl nicotinate chitosan (TAMNCS) was prepared via azide-alkyne click reaction. Its structure was characterized by FT-IR, (1)H NMR, elemental analysis, DSC, and SEM. In vitro antifungal properties of TAMNCS against Rhizoctonia solani Kühn (R. solani), Stemphylium solani weber (S. solani), and Alternaria porri (A. porri) were studied at the concentrations ranged from 0.25 mg/mL to 1.0 mg/mL. Experiments conducted displayed the derivative had obviously enhanced antifungal activity after chemical modification compared with original chitosan. Moreover, it was shown that TAMNCS can 94.2% inhibit growth of A. porri at 1.0 mg/mL, while dose at which the fungicide triadimefon had lower inhibitory index (62.2%). The primary antifungal results described here indicate this derivative may be a promising candidate as an antifungal agent. Copyright © 2013 Elsevier B.V. All rights reserved.

Antifungal activity of amphotericin B and voriconazole against the biofilms and biofilm-dispersed cells of Candida albicans employing a newly developed in vitro pharmacokinetic model.

PubMed

El-Azizi, Mohamed; Farag, Noha; Khardori, Nancy

2015-04-03

Candida albicans is a common cause of a variety of superficial and invasive disseminated infections the majority of which are associated with biofilm growth on implanted devices. The aim of the study is to evaluate the activity of amphotericin B and voriconazole against the biofilm and the biofilm-dispersed cells of Candida albicans using a newly developed in vitro pharmacokinetic model which simulates the clinical situation when the antifungal agents are administered intermittently. RPMI medium containing 1-5 X 10(6) CFU/ml of C. albicans was continuously delivered to the device at 30 ml/h for 2 hours. The planktonic cells were removed and biofilms on the catheter were kept under continuous flow of RPMI medium at 10 ml/h. Five doses of amphotericin B or voriconazole were delivered to 2, 5 and 10 day-old biofilms at initial concentrations (2 and 3 μg/ml respectively) that were exponentially diluted. Dispersed cells in effluents from the device were counted and the adherent cells on the catheter were evaluated after 48 h of the last dose. The minimum inhibitory concentration of voriconazole and amphotericin B against the tested isolate was 0.0325 and 0.25 μg/ml respectively. Amphotericin B significantly reduced the dispersion of C. albicans cells from the biofilm. The log10 reduction in the dispersed cells was 2.54-3.54, 2.30-3.55, and 1.94-2.50 following addition of 5 doses of amphotericin B to 2-, 5- and 10-day old biofilms respectively. The number of the viable cells within the biofilm was reduced by 18 (±7.63), 5 and 4% following addition of the 5 doses of amphotericin B to the biofilms respectively. Voriconazole showed no significant effect on the viability of C. albicans within the biofilm. Both antifungal agents failed to eradicate C. albicans biofilm or stop cell dispersion from them and the resistance progressed with maturation of the biofilm. These findings go along with the need for removal of devices in spite of antifungal therapy in patients

Susceptibility of 100 filamentous fungi: comparison of two diffusion methods, Neo-Sensitabs and E-test, for amphotericin B, caspofungin, itraconazole, voriconazole and posaconazole.

PubMed

Colosi, Ioana A; Faure, Odile; Dessaigne, Bérangére; Bourdon, Cécile; Lebeau, Bernadette; Colosi, Horaţiu A; Pelloux, Hervé

2012-05-01

We compared the E-test method to that of the Neo-Sensitabs tablet diffusion assay for evaluating the in vitro susceptibility of 100 clinical isolates of filamentous fungi (Aspergillus spp., Fusarium spp., Scedosporium spp., zygomycetes and other molds) to amphotericin B, itraconazole, voriconazole, caspofungin, and posaconazole. We determined the categorical agreement level between E-test minimum inhibitory concentrations (MIC) and tablet end-points, as opposed to the following disagreement parameters: very major error - resistant parameter (R) in E-test and susceptible (S) in tablet; major error - S by E-test and R by tablet; minor error - shifts between S and susceptible dose-dependent (S-DD) or S-DD and R. We also performed linear regression analyses and computed Pearson's correlation coefficients (R values) between the log transforms of MICs and the inhibition zone diameters of the five studied antifungal agents. For itraconazole we obtained 97% categorical agreement and R = -0.727. Categorical agreement for caspofungin and voriconazole was 96% and R =-0.821 and R = -0.789, respectively. For posaconazole the categorical agreement was 94% and R =-0.743. Amphotericin B exhibited a lower degree of agreement (76%, R = -0.672), especially in studies of Aspergillus spp. Our results suggest a potential value of the Neo-Sensitabs assay for in vitro susceptibility testing of molds to itraconazole, voriconazole, caspofungin and posaconazole, while amphotericin B exhibited an overall lower degree of agreement.

In-vitro assessment of the probiotic potential of Lactobacillus plantarum KCC-24 isolated from Italian rye-grass (Lolium multiflorum) forage.

PubMed

Vijayakumar, Mayakrishnan; Ilavenil, Soundharrajan; Kim, Da Hye; Arasu, Mariadhas Valan; Priya, Kannappan; Choi, Ki Choon

2015-04-01

The aim of the present study was to determine the probiotic potential of the lactic acid bacteria Lactobacillus plantarum KCC-24 (L. plantarum KCC-24), that was isolated and characterized from Italian ryegrass (Lolium multiflorum) forage. The following experiments were performed to assess the probiotic characteristics such as antifungal activity, antibiotic susceptibility, resistance to low pH, stimulated gastric juice and bile salts, proteolytic activity, auto-aggregation, cell surface hydrophobicity, and in vitro antioxidant property. The isolated L. plantarum KCC-24 exhibited significant antifungal activity against the various fungal strains of Aspergillus fumigatus (73.43%), Penicillium chrysogenum (59.04%), Penicillium roqueforti (56.67%), Botrytis elliptica (40.23%), Fusarium oxysporum (52.47%) and it was susceptible to numerous antibiotics, survived in low pH, was resistant to stimulated gastric juices and bile salts (0.3% w/v). Moreover, L. plantarum KCC-24 exhibited good proteolytic activity. In addition L. plantarum KCC-24 showed potent antioxidant and hydrogen peroxide resistant property. In conclusion, the isolated L. plantarum KCC-24 exhibited several characteristics to prove it's excellent as a potential probiotic candidate for developing quality food for ruminant animals and human. Copyright © 2015 Elsevier Ltd. All rights reserved.

Econazole imprinted textiles with antifungal activity.

PubMed

Hossain, Mirza Akram; Lalloz, Augustine; Benhaddou, Aicha; Pagniez, Fabrice; Raymond, Martine; Le Pape, Patrice; Simard, Pierre; Théberge, Karine; Leblond, Jeanne

2016-04-01

In this work, we propose pharmaceutical textiles imprinted with lipid microparticles of Econazole nitrate (ECN) as a mean to improve patient compliance while maintaining drug activity. Lipid microparticles were prepared and characterized by laser diffraction (3.5±0.1 μm). Using an optimized screen-printing method, microparticles were deposited on textiles, as observed by scanning electron microscopy. The drug content of textiles (97±3 μg/cm(2)) was reproducible and stable up to 4 months storage at 25 °C/65% Relative Humidity. Imprinted textiles exhibited a thermosensitive behavior, as witnessed by a fusion temperature of 34.8 °C, which enabled a larger drug release at 32 °C (temperature of the skin) than at room temperature. In vitro antifungal activity of ECN textiles was compared to commercial 1% (wt/wt) ECN cream Pevaryl®. ECN textiles maintained their antifungal activity against a broad range of Candida species as well as major dermatophyte species. In vivo, ECN textiles also preserved the antifungal efficacy of ECN on cutaneous candidiasis infection in mice. Ex vivo percutaneous absorption studies demonstrated that ECN released from pharmaceutical textiles concentrated more in the upper skin layers, where the fungal infections develop, as compared to dermal absorption of Pevaryl®. Overall, these results showed that this technology is promising to develop pharmaceutical garments textiles for the treatment of superficial fungal infections. Copyright © 2016 Elsevier B.V. All rights reserved.

In Vitro Activity of Miltefosine against Candida albicans under Planktonic and Biofilm Growth Conditions and In Vivo Efficacy in a Murine Model of Oral Candidiasis

PubMed Central

Chaturvedi, Ashok K.; Rozental, Sonia

2015-01-01

The generation of a new antifungal against Candida albicans biofilms has become a major priority, since biofilm formation by this opportunistic pathogenic fungus is usually associated with an increased resistance to azole antifungal drugs and treatment failures. Miltefosine is an alkyl phospholipid with promising antifungal activity. Here, we report that, when tested under planktonic conditions, miltefosine displays potent in vitro activity against multiple fluconazole-susceptible and -resistant C. albicans clinical isolates, including isolates overexpressing efflux pumps and/or with well-characterized Erg11 mutations. Moreover, miltefosine inhibits C. albicans biofilm formation and displays activity against preformed biofilms. Serial passage experiments confirmed that miltefosine has a reduced potential to elicit resistance, and screening of a library of C. albicans transcription factor mutants provided additional insight into the activity of miltefosine against C. albicans growing under planktonic and biofilm conditions. Finally, we demonstrate the in vivo efficacy of topical treatment with miltefosine in the murine model of oropharyngeal candidiasis. Overall, our results confirm the potential of miltefosine as a promising antifungal drug candidate, in particular for the treatment of azole-resistant and biofilm-associated superficial candidiasis. PMID:26416861

In vitro selection of Staphylococcus aureus mutants resistant to tigecycline with intermediate susceptibility to vancomycin.

PubMed

Herrera, Melina; Di Gregorio, Sabrina; Fernandez, Silvina; Posse, Graciela; Mollerach, Marta; Di Conza, José

2016-03-08

Tigecycline (TIG) is an antibiotic belonging to the glycylcyclines class and appears to be a good choice to fight infections caused by Staphylococcus aureus. To date, TIG exhibits good activity against this microorganism. The aim of this work was to obtain in vitro mutants of S. aureus resistant to TIG and evaluate possible changes in their susceptibility patterns to other antibiotics. Two mutants of S. aureus resistant to TIG (MIC = 16 µg/mL) were selected in vitro from clinical isolates of methicillin-resistant S. aureus. In both mutants, corresponding to different lineage (ST5 and ST239), an increase of efflux activity against TIG was detected. One mutant also showed a reduced susceptibility to vancomycin, corresponding to the VISA phenotype (MIC = 4 µg/mL), with a loss of functionality of the agr locus. The emergence of the VISA phenotype was accompanied by an increase in oxacillin and cefoxitin MICs. This study demonstrates that, under selective pressure, the increase of efflux activity in S. aureus is one of the mechanisms that may be involved in the emergence of tigecycline resistance. The emergence of this phenotype may eventually be associated to changes in susceptibility to other antibiotics such oxacillin and vancomycin.

Antifungal Effect of a Dental Tissue Conditioner Containing Nystatin-Loaded Alginate Microparticles.

PubMed

Kim, Hyun-Jin; Son, Jun Sik; Kwon, Tae-Yub

2018-02-01

In this in vitro study, nystatin-alginate microparticles were successfully fabricated to control the release of nystatin from a commercial dental tissue conditioner. These nystatin-alginate microparticles were spherical and had a slightly rough surface. The microparticles incorporated into the tissue conditioner were distributed homogeneously throughout the tissue conditioner matrix. The incorporation of the microparticles did not deteriorate the mechanical properties of the original material. The agar diffusion test results showed that the tissue conditioner containing the microparticles had a good antifungal effect against Candida albicans. The nystatin-alginate microparticles efficiently controlled the release of nystatin from the tissue conditioner matrix over the experimental period of 14 days. Moreover, the nystatin-alginate microparticles incorporated in the tissue conditioner showed effective antifungal function even at lower concentrations of nystatin. The current study suggests that the tissue conditioner containing the nystatin-alginate microparticle carrier system has potential as an effective antifungal material.

In vitro susceptibility of filamentous fungi from mycotic keratitis to azole drugs.

PubMed

Shobana, C S; Mythili, A; Homa, M; Galgóczy, L; Priya, R; Babu Singh, Y R; Panneerselvam, K; Vágvölgyi, C; Kredics, L; Narendran, V; Manikandan, P

2015-03-01

The in vitro antifungal activities of azole drugs viz., itraconazole, voriconazole, ketoconazole, econazole and clotrimazole were investigated in order to evaluate their efficacy against filamentous fungi isolated from mycotic keratitis. The specimen collection was carried out from fungal keratitis patients attending Aravind eye hospital and Post-graduate institute of ophthalmology, Coimbatore, India and was subsequently processed for the isolation of fungi. The dilutions of antifungal drugs were prepared in RPMI 1640 medium. Minimum inhibitory concentrations (MICs) were determined and MIC50 and MIC90 were calculated for each drug tested. A total of 60 fungal isolates were identified as Fusarium spp. (n=30), non-sporulating moulds (n=9), Aspergillus flavus (n=6), Bipolaris spp. (n=6), Exserohilum spp. (n=4), Curvularia spp. (n=3), Alternaria spp. (n=1) and Exophiala spp. (n=1). The MICs of ketoconazole, clotrimazole, voriconazole, econazole and itraconazole for all the fungal isolates ranged between 16 μg/mL and 0.03 μg/mL, 4 μg/mL and 0.015 μg/mL, 8 μg/mL and 0.015 μg/mL, 8 μg/mL and 0.015 μg/mL and 32 μg/mL and 0.06 μg/mL respectively. From the MIC50 and MIC90 values, it could be deciphered that in the present study, clotrimazole was more active against the test isolates at lower concentrations (0.12-5 μg/mL) when compared to other drugs tested. The results suggest that amongst the tested azole drugs, clotrimazole followed by voriconazole and econazole had lower MICs against moulds isolated from mycotic keratitis. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Multicenter Comparison of the Etest and EUCAST Methods for Antifungal Susceptibility Testing of Candida Isolates to Micafungin.

PubMed

Bougnoux, M-E; Dannaoui, E; Accoceberry, I; Angoulvant, A; Bailly, E; Botterel, F; Chevrier, S; Chouaki, T; Cornet, M; Dalle, F; Datry, A; Dupuis, A; Fekkar, A; Gangneux, J P; Guitard, J; Hennequin, C; Le Govic, Y; Le Pape, P; Maubon, D; Ranque, S; Sautour, M; Sendid, B; Chandenier, J

2016-08-01

In vitro susceptibility of 933 Candida isolates, from 16 French hospitals, to micafungin was determined using the Etest in each center. All isolates were then sent to a single center for determination of MICs by the EUCAST reference method. Overall essential agreement between the two tests was 98.5% at ±2 log2 dilutions and 90.2% at ±1 log2 dilutions. Categorical agreement was 98.2%. The Etest is a valuable alternative to EUCAST for the routine determination of micafungin MICs in medical mycology laboratories. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp.

PubMed Central

Moussa, Ahmed; Noureddine, Djebli; Saad, Aissat; Abdelmelek, Meslem; Abdelkader, Benhalima

2012-01-01

Objective To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Methods Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. Results The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7–23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09–93.48)% and (4.90–99.70)% v/v, respectively. Conclusions This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans. PMID:23569970

In vitro antibiotic susceptibilities of Neisseria gonorrhoeae isolates in the Philippines.

PubMed Central

Clendennen, T E; Hames, C S; Kees, E S; Price, F C; Rueppel, W J; Andrada, A B; Espinosa, G E; Kabrerra, G; Wignall, F S

1992-01-01

Antibiotic susceptibility surveillance testing was performed on clinical isolates of Neisseria gonorrhoeae collected in September 1989 in the Philippines. beta-Lactamase was produced by 77 (55%) of 140 isolates. In vitro MIC testing revealed significant resistance to penicillin (MIC for 90% of isolates [MIC90], greater than 64 micrograms/ml), tetracycline (MIC90, 4 micrograms/ml), and cefmetazole (MIC90, 8 micrograms/ml). Spectinomycin resistance was rare (10 of 117), but the MIC90 was 32 micrograms/ml. Isolates were susceptible to fluoroquinolones and cephalosporins at the time of this survey, as evidenced by the MIC90s of ciprofloxacin (0.25 microgram/ml), norfloxacin (2.0 micrograms/ml), ofloxacin (0.625 microgram/ml), cefpodoxime (2.0 micrograms/ml), cefotaxime (1.0 microgram/ml), ceftazidime (0.25 microgram/ml), ceftizoxime (0.25 microgram/ml), and ceftriaxone (0.06 microgram/ml). To date, ceftriaxone resistance has not emerged, despite the widespread use of this antibiotic in the Philippines. PMID:1605592

In vitro evaluation of BacT/Alert FA blood culture bottles and T2Candida assay for the detection of Candida in the presence of antifungals.

PubMed

Beyda, Nicholas D; Amadio, Jonathan; Rodriguez, Jose R; Malinowski, Karen; Garey, Kevin W; Wanger, Audrey; Ostrosky-Zeichner, Luis

2018-06-13

The T2Candida assay is a novel, non-culture based assay for the diagnosis of candidemia directly from whole blood. The impact of antifungals on the performance of the T2Candida assay and blood culture bottles have not been well described. In this study, the performance of the T2Candida assay was compared to that of blood culture in detecting Candida spp. in spiked blood cultures with or without the presence of antifungals. Clinical bloodstream isolates of Candida spp. were inoculated into human whole blood at low (1 - 5 cells/mL) and high (10-50 cells/mL) concentrations with or without presence of caspofungin and fluconazole. Time to detection (TTD) was assessed for prepared samples using BacTAlert FA aerobic blood culture bottles or the T2Candida assay. In the absence of antifungals, T2Candida assay sensitivity was comparable to that of blood culture at both the low and high inoculum (95% vs. 97.5% and 100% vs. 100%, respectively) and had an average TTD that was significantly faster (5.1 hrs vs 27.2 - 30 hrs, respectively). Neither caspofungin nor fluconazole was observed to impact the sensitivity or TTD of the T2Candida assay, while fluconazole reduced overall blood culture sensitivity by 7.5% - 12.5% (at low and high inoculum, respectively) and significantly prolonged the TTD of C. albicans, C. tropicalis , and C. parapsilosis by 14.8 - 67 hrs. Neither caspofungin nor fluconazole impacted the performance of the T2Candida assay in-vitro and may be useful for the diagnosis of candidemia in patients receiving antifungal therapy. Copyright © 2018 American Society for Microbiology.

Citral and carvone chemotypes from the essential oils of Colombian Lippia alba (Mill.) N.E. Brown: composition, cytotoxicity and antifungal activity.

PubMed

Mesa-Arango, Ana Cecilia; Montiel-Ramos, Jehidys; Zapata, Bibiana; Durán, Camilo; Betancur-Galvis, Liliana; Stashenko, Elena

2009-09-01

Two essential oils of Lippia alba (Mill.) N.E. Brown (Verbenacea), the carvone and citral chemotypes and 15 of their compounds were evaluated to determine cytotoxicity and antifungal activity. Cytotoxicity assays for both the citral and carvone chemotypes were carried out with tetrazolium-dye, which showed a dose-dependent cytotoxic effect against HeLa cells. Interestingly, this effect on the evaluated cells (HeLa and the non-tumoural cell line, Vero) was lower than that of commercial citral alone. Commercial citral showed the highest cytotoxic activity on HeLa cells. The antifungal activity was evaluated against Candida parapsilosis, Candida krusei, Aspergillus flavus and Aspergillus fumigatus strains following the standard protocols, Antifungal Susceptibility Testing Subcommittee of the European Committee on Antibiotic Susceptibility Testing and CLSI M38-A. Results demonstrated that the most active essential oil was the citral chemotype, with geometric means-minimal inhibitory concentration (GM-MIC) values of 78.7 and 270.8 microg/mL for A. fumigatus and C. krusei, respectively. Commercial citral showed an antifungal activity similar to that of the citral chemotype (GM-MIC values of 62.5 microg/mL for A. fumigatus and 39.7 microg/mL for C. krusei). Although the citronellal and geraniol were found in lower concentrations in the citral chemotype, they had significant antifungal activity, with GM-MIC values of 49.6 microg/mL for C. krusei and 176.8 microg/mL for A. fumigatus.

An Azole-Tolerant Endosomal Trafficking Mutant of Candida albicans Is Susceptible to Azole Treatment in a Mouse Model of Vaginal Candidiasis

PubMed Central

Peters, Brian M.; Luna-Tapia, Arturo; Tournu, Hélène; Rybak, Jeffrey M.; Rogers, P. David

2017-01-01

ABSTRACT We recently reported that a Candida albicans endosomal trafficking mutant continues to grow after treatment with the azole antifungals. Herein, we report that the vps21Δ/Δ mutant does not have a survival advantage over wild-type isolates after fluconazole treatment in a mouse model of vaginal candidiasis. Furthermore, loss of VPS21 does not synergize with established mechanisms of azole resistance, such as overexpression of efflux pumps or of Erg11p, the target enzyme of the azoles. In summary, although loss of VPS21 function enhances C. albicans survival after azole treatment in vitro, it does not seem to affect azole susceptibility in vivo. PMID:28348159

[Activity of butenafine against ocular pathogenic filamentous fungi in vitro].

PubMed

Xu, Yan; Pang, Guang-ren; Zhao, Dong-qing; Gao, Chuan-wen; Zhou, Lu-tan; Sun, Sheng-tao; Wang, Bing-liang; Chen, Zu-ji

2010-01-01

To investigate antifungal activity of butenafine in comparison with that of natamycin, amphotericin B and fluconazole against ocular pathogenic filamentous fungi in vitro. It was an experimental study. Susceptibility tests were performed against 260 isolates of ocular pathogenic filamentous fungi by broth dilution antifungal susceptibility test of filamentous fungi approved by the Clinical and Laboratory Standards Institute (CLSI) M38-A document. The isolates included Fusarium spp. (136), Aspergillus spp. (98), Alternaria alternata (9), Curvularia lunata (3), and unusual ocular pathogens (14). Final concentration ranged from 0.008 to 16.000 mg/L for butenafine, from 0.031 to 16.000 mg/L for amphotericin B and natamycin, and from 0.5 to 256.0 mg/L for fluconazole. Following incubation at 35 degrees C for 48 h, minimal inhibitory concentration (MIC) was determined according to the CLSI M38-A document. For amphotericin B and natamycin, the MIC was defined as the lowest drug concentration that prevented any discernible growth. For butenafine and fluconazole, the MIC was defined as the lowest concentration in which an approximately 75% reduction compared to the growth of the control was observed. Candida parapsilosis ATCC22019 was used as quality control strains to validated the results. Mean MIC and MIC range, the MIC at which 50% of the isolates tested were inhibited (MIC(50)) and the MIC at which 90% of the isolates tested were inhibited (MIC(90)), were provided for all the isolates tested by using descriptive statistical analysis with the statistical SPSS package (version 13.0). MIC(90) of butenafine, natamycin, amphotericin B and fluconazole were 4, 8, 2 and 512 mg/L for Fusarium spp., respectively; 0.063, 32.000, 2.000 and 256.000 mg/L for Aspergillus spp., respectively; 0.5, 8.0, 2.0 and 128.0 mg/L for Alternaria alternate, respectively; 0.125, 2.000, 0.500 and 4.000 mg/L for Curvularia lunata, respectively; and 1, 4, 1 and 256 mg/L for unusual ocular pathogens

Anti-inflammatory activity of Vismia guianensis (Aubl.) Pers. extracts and antifungal activity against Sporothrix schenckii.

PubMed

Oliveira, A H; de Oliveira, G G; Carnevale Neto, F; Portuondo, D F; Batista-Duharte, A; Carlos, I Z

2017-01-04

Vismia guianensis (Aubl.) Pers. is traditionally used in North and Northeast of Brazil for the treatment of dermatomycoses. Since the strategy associating immunomodulators with antifungal drugs seems to be promissory to improve the treatment efficacy in fungal infections, we aimed to investigate the antifungal activity of V. guianensis ethanolic extract of leaves (VGL) and bark (VGB) against Sporothrix schenckii ATCC 16345 and their antinflammatory activities. The extracts were analyzed by HPLC-DAD-IT MS/MS for in situ identification of major compounds. Antifungal activity was evaluated in vitro (microdilution test) and in vivo using a murine model of S. schenckii infection. The production of TNF-α, IFN-γ, IL-4, IL-10 and IL-12 by measured by ELISA, as well as measured the production and inhibition of the NO after treatment with the plant extracts or itraconazole (ITR). Two O-glucosyl-flavonoids and 16 prenylated benzophenone derivatives already described for Vismia were detected. Both VGL and VGB showed significant antifungal activity either in in vitro assay of microdilution (MIC=3.9µg/mL) and in vivo model of infection with reduction of S. schenckii load in spleen. It was also observed a predominance of reduction in the production of NO and the proinflammatory cytokines evaluated except TNFα, but with stimulation of IL-10, as evidence of a potential anti-inflammatory effect associated. The results showed that both VGL and VGB have a significant antifungal against S. schenckii and an anti-inflammatory activity. These results can support the use of these extracts for alternative treatment of sporotrichosis. Copyright © 2016 Elsevier B.V. All rights reserved.

The Candida albicans Ddr48 protein is essential for filamentation, stress response, and confers partial antifungal drug resistance.

PubMed

Dib, Leila; Hayek, Peter; Sadek, Helen; Beyrouthy, Berna; Khalaf, Roy A

2008-06-01

Candida albicans is a dimorphic pathogenic fungus that causes mucosal and systemic infections. C. albicans pathogenicity is attributed to its ability to exist in different morphologic states and to respond to stress by up regulating several key genes. DDR48 is a stress-associated gene involved in DNA repair and in response to antifungal drug exposure. One allele of DDR48 was knocked out by homologous recombination that inserted a marker cassette in its position. Furthermore, reintroducing DDR48 on a plasmid created a revertant strain. Strains were grown on filamentation inducing and noninducing media, subjected to an oxidative stress challenge, injected into mice to assess virulence, and assayed for antifungal susceptibility by the E-test method. DDR48 was found to be haploid insufficient and possibly essential, since only a heterozygote, but not a homozygous, null mutant was generated. The mutant was filamentation defective on all hyphal media tested including serum and corn meal agar. Discrepancies in drug resistance profiles also were present: compared with the parental strain, DDR48/ddr48 heterozygote strain was susceptible in a dose-dependent manner to itraconazole and fluconazole and susceptible to ketoconazole. The mutant also appeared to be hypersensitive to a potentially lethal hydrogen peroxide challenge. However, no reduction in virulence of the mutant was observed. The present findings provide evidence that DDR48 is essential for filamentation, stress response, and possibly viability of C. albicans, making it a prime target for antifungal drug design.

Antifungal activity of food additives in vitro and as ingredients of hydroxypropyl methylcellulose-lipid edible coatings against Botrytis cinerea and Alternaria alternata on cherry tomato fruit.

PubMed

Fagundes, Cristiane; Pérez-Gago, María B; Monteiro, Alcilene R; Palou, Lluís

2013-09-16

The antifungal activity of food additives or 'generally recognized as safe' (GRAS) compounds was tested in vitro against Botrytis cinerea and Alternaria alternata. Radial mycelial growth of each pathogen was measured in PDA Petri dishes amended with food preservatives at 0.2, 1.0, or 2.0% (v/v) after 3, 5, and 7 days of incubation at 25 °C. Selected additives and concentrations were tested as antifungal ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings. The curative activity of stable coatings was tested in in vivo experiments. Cherry tomatoes were artificially inoculated with the pathogens, coated by immersion about 24 h later, and incubated at 20 °C and 90% RH. Disease incidence and severity (lesion diameter) were determined after 6, 10, and 15 days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. In general, HPMC-lipid antifungal coatings controlled black spot caused by A. alternata more effectively than gray mold caused by B. cinerea. Overall, the best results for reduction of gray mold on cherry tomato fruit were obtained with coatings containing 2.0% of potassium carbonate, ammonium phosphate, potassium bicarbonate, or ammonium carbonate, while 2.0% sodium methylparaben, sodium ethylparaben, and sodium propylparaben were the best ingredients for coatings against black rot. © 2013 Elsevier B.V. All rights reserved.

In vitro production and antifungal activity of peptide ABP-dHC-cecropin A.

PubMed

Zhang, Jiaxin; Movahedi, Ali; Xu, Junjie; Wang, Mengyang; Wu, Xiaolong; Xu, Chen; Yin, Tongming; Zhuge, Qiang

2015-04-10

The antimicrobial peptide ABP-dHC-cecropin A is a small cationic peptide with potent activity against a wide range of bacterial species. Evidence of antifungal activity has also been suggested; however, testing of this peptide has been limited due to the low expression of cecropin proteins in Escherichia coli. To improve expression of this peptide in E. coli, ABP-dHC-cecropin A was cloned into a pSUMO vector and transformed into E. coli, resulting in the production of a pSUMO-ABP-dHC-cecropin A fusion protein. The soluble form of this protein was then purified by Ni-IDA chromatography, yielding a total of 496-mg protein per liter of fermentation culture. The SUMO-ABP-dHC-cecropin A fusion protein was then cleaved using a SUMO protease and re-purified by Ni-IDA chromatography, yielding a total of 158-mg recombinant ABP-dHC-cecropin A per liter of fermentation culture at a purity of ≥94%, the highest yield reported to date. Antifungal activity assays performed using this purified recombinant peptide revealed strong antifungal activity against both Candida albicans and Neurospora crassa, as well as Rhizopus, Fusarium, Alternaria, and Mucor species. Combined with previous analyses demonstrating strong antibacterial activity against a number of important bacterial pathogens, these results confirm the use of ABP-dHC-cecropin A as a broad-spectrum antimicrobial peptide, with significant therapeutic potential. Copyright © 2015 Elsevier B.V. All rights reserved.

An ancient plant Lawsonia inermis (henna): determination of in vitro antifungal activity against dermatophytes species.

PubMed

Gozubuyuk, G S; Aktas, E; Yigit, N

2014-12-01

World is endowed with a rich wealth of medicinal plants. There is a widespread belief that green medicines are healthier and more harmless or safer than synthetic ones. Medicinal plants have been used to cure a number of diseases. The ancient plant Lawsonia inermis or henna is used as medicinal plant because of its attributed strong fungicidal, anti-inflammatory, analgesic, antibacterial, virucidal, antiparasitic, antiamoebiasis, astringent, antihemorrhagic, hypotensive, sedative, anticancer effect and possible anti-sweating properties. In this study, we investigated antifungal activity of L. inermis against clinical dermatophytes species. This study was carried out using 70 clinical isolates of dermatophytes representing six different species; 44 Trichophyton rubrum, 8 Trichophyton mentagrophytes, 6 Microsporum canis, 6 Trichophyton tonsurans, 4 Epidermophyton floccosum, and 2 Trichophyton violaceum. The antifungal activity of L. inermis (henna) was determined by agar diffusion method and henna was used as paste form. Henna paste showed the high antifungal activity against all dermatophytes species (20 to 50mm inhibition zone). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Role of Pfmdr1 in In Vitro Plasmodium falciparum Susceptibility to Chloroquine, Quinine, Monodesethylamodiaquine, Mefloquine, Lumefantrine, and Dihydroartemisinin

PubMed Central

Wurtz, Nathalie; Fall, Bécaye; Pascual, Aurélie; Fall, Mansour; Baret, Eric; Camara, Cheikhou; Nakoulima, Aminata; Diatta, Bakary; Fall, Khadidiatou Ba; Mbaye, Pape Saliou; Diémé, Yaya; Bercion, Raymond; Wade, Boubacar

2014-01-01

The involvement of Pfmdr1 (Plasmodium falciparum multidrug resistance 1) polymorphisms in antimalarial drug resistance is still debated. Here, we evaluate the association between polymorphisms in Pfmdr1 (N86Y, Y184F, S1034C, N1042D, and D1246Y) and Pfcrt (K76T) and in vitro responses to chloroquine (CQ), mefloquine (MQ), lumefantrine (LMF), quinine (QN), monodesethylamodiaquine (MDAQ), and dihydroartemisinin (DHA) in 174 Plasmodium falciparum isolates from Dakar, Senegal. The Pfmdr1 86Y mutation was identified in 14.9% of the samples, and the 184F mutation was identified in 71.8% of the isolates. No 1034C, 1042N, or 1246Y mutations were detected. The Pfmdr1 86Y mutation was significantly associated with increased susceptibility to MDAQ (P = 0.0023), LMF (P = 0.0001), DHA (P = 0.0387), and MQ (P = 0.00002). The N86Y mutation was not associated with CQ (P = 0.214) or QN (P = 0.287) responses. The Pfmdr1 184F mutation was not associated with various susceptibility responses to the 6 antimalarial drugs (P = 0.168 for CQ, 0.778 for MDAQ, 0.324 for LMF, 0.961 for DHA, 0.084 for QN, and 0.298 for MQ). The Pfmdr1 86Y-Y184 haplotype was significantly associated with increased susceptibility to MDAQ (P = 0.0136), LMF (P = 0.0019), and MQ (P = 0.0001). The additional Pfmdr1 86Y mutation increased significantly the in vitro susceptibility to MDAQ (P < 0.0001), LMF (P < 0.0001), MQ (P < 0.0001), and QN (P = 0.0026) in wild-type Pfcrt K76 parasites. The additional Pfmdr1 86Y mutation significantly increased the in vitro susceptibility to CQ (P = 0.0179) in Pfcrt 76T CQ-resistant parasites. PMID:25199781

In vitro antimicrobial susceptibility of Mycoplasma bovis isolated in Israel from local and imported cattle.

PubMed

Gerchman, Irena; Levisohn, Sharon; Mikula, Inna; Lysnyansky, Inna

2009-06-12

Monitoring of susceptibility to antibiotics in field isolates of pathogenic bovine mycoplasmas is important for appropriate choice of treatment. Our study compared in vitro susceptibility profiles of Mycoplasma bovis clinical strains, isolated during 2005-2007 from Israeli and imported calves. Minimal inhibitory concentration (MIC) values were determined for macrolides by the microbroth dilution test, for aminoglycosides by commercial Etest, and for fluoroquinolones and tetracyclines by both methods. Notably, although correlation between the methods was generally good, it was not possible to determine the MIC endpoint for enrofloxacin-resistant strains (MIC > or =2.5 microg/ml in the microtest) by Etest. Comparison of antibiotic susceptibility profiles between local and imported M. bovis strains revealed that local strains were significantly more resistant to macrolides than most isolates from imported animals, with MIC(50) of 128 microg/ml vs. 2 microg/ml for tilmicosin and 8 microg/ml vs. 1 microg/ml for tylosin, respectively. However, local strains were more susceptible than most imported strains to fluoroquinolones and spectinomycin. Difference in susceptibility to tetracycline, doxycycline and oxytetracycline between local and imported strains was expressed in MIC(90) values for imported strains in the susceptible range compared to intermediate susceptibility for local strains. The marked difference in susceptibility profiles of M. bovis strains isolated from different geographical regions seen in this study emphasizes the necessity for performing of the antimicrobial susceptibility testing periodically and on a regional basis.

In vitro antifungal potentials of bioactive compound oleic acid, 3-(octadecyloxy) propyl ester isolated from Lepidagathis cristata Willd. (Acanthaceae) inflorescence.

PubMed

Abubacker, Maghdu Nainamohamed; Devi, Palaniyappan Kamala

2014-09-01

To identify bioactive compound oleic acid, 3-(octadecyloxy) propyl ester from Lepidagathis cristata Willd. (L. cristata) and to assess antifungal potentials of the isolated compound. Aqueous extracts of L. cristata inflorescence were used for this study. The major bioactive compound isolated was tested for antifungal activities. The major bioactive compound oleic acid, 3-(octadecyloxy) propyl ester was isolated from the inflorescence of L. cristata. The bioactive compound was tested for antifungal potentials and found to be highly effective to plant pathogenic fungi Colletotrichum fulcatum NCBT 146, Fusarium oxysporum NCBT 156 and Rhizoctonia solani NCBT 196 as well as for the human pathogenic fungi Curvularia lunata MTCC 2030 and Microsporum canis MTCC 2820. The results justify the antifungal potentials of both plant and human pathogenic fungi. The plant bioactive compound will be helpful in herbal antifungal formulations. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Reversal of efflux mediated antifungal resistance underlies synergistic activity of two monoterpenes with fluconazole.

PubMed

Ahmad, Aijaz; Khan, Amber; Manzoor, Nikhat

2013-01-23

Thymol (THY) and carvacrol (CARV), the principal chemical components of thyme oil have long been known for their wide use in medicine due to antimicrobial and disinfectant properties. This study, however, draws attention to a possible synergistic antifungal effect of these monoterpenes with azole antimycotic-fluconazole. Resistance to azoles in Candida albicans involves over-expression of efflux-pump genes MDR1, CDR1, CDR2 or mutations and over-expression of target gene ERG11. The inhibition of drug efflux pumps is considered a feasible strategy to overcome clinical antifungal resistance. To put forward this approach, we investigated the combination effects of these monoterpenes and FLC against 38 clinically obtained FLC-sensitive, and eleven FLC-resistant Candida isolates. Synergism was observed with combinations of THY-FLC and CARV-FLC evaluated by checkerboard microdilution method and nature of the interactions was calculated by FICI. In addition, antifungal activity was assessed using agar-diffusion and time-kill curves. The drug efflux activity was determined using two dyes, Rhodamine6G (R6G) and fluorescent Hoechst 33342. No significant differences were observed in dye uptakes between FLC-susceptible and resistant isolates, incubated in glucose free buffer. However, a significantly higher efflux was recorded in FLC-resistant isolates when glucose was added. Both monoterpenes inhibited efflux by 70-90%, showing their high potency to block drug transporter pumps. Significant differences, in the expression levels of CDR1 and MDR1, induced by monoterpenes revealed reversal of FLC-resistance. The selectively fungicidal characteristics and ability to restore FLC susceptibility in resistant isolates signify a promising candidature of THY and CARV as antifungal agents in combinational treatments for candidiasis. Copyright © 2012 Elsevier B.V. All rights reserved.

A case of Candida albicans fungus balls in the urinary tract appeared during the course of antifungal treatment for Candida endophthalmitis.

PubMed

Onozawa, Kyoko; Miyake, Noriko; Iwasaki, Noriko; Nishida, Ruriko; Chong, Yong; Shimoda, Shinji; Shimono, Nobuyuki; Akashi, Koichi

2015-09-01

Fungus balls have been rarely implicated as a cause of urinary tract obstruction. Here, we report a case of Candida albicans fungus balls in the urinary tract after the treatment of Candida endophthalmitis that has enough periods and adequate amount of antifungal agents. The patient completely recovered from this rare complication by irrigating through single-J stent and changing antifungal agents. Here we emphasize that we should take into account not only the susceptibility test results but also the difference in excretion route and tissue distribution of antifungal agents. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

In vitro antifungal, probiotic, and antioxidant functional properties of a novel Lactobacillus paraplantarum isolated from fermented dates in Saudi Arabia.

PubMed

Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah

2017-12-01

Fermented foods produced using dates are used in Gulf countries as beneficial and healthful foods. The beneficial microbial flora in fermented dates contributes to maintaining the nutritional properties of dates by preventing the growth of spoilage fungi. Here, we examined the antifungal, probiotic, and antioxidant properties of the novel Lactobacillus strain D-3 isolated from fermented dates. Analyzing the morphological, physiological, and biochemical characteristics of this strain demonstrated that it was similar to Lactobacillus species, and molecular-level amplification of the 16S rRNA gene showed that it belonged to Lactobacillus paraplantarum. Under shake flask cultivation using date juice, the strain produced significant amounts of ethanol and lactic, succinic, and acetic acids. Purification of benzoic acid extracted from the extracellular fermentation medium was confirmed by nuclear magnetic resonance, and infrared and mass spectral data revealed minimum inhibitory concentration values of 10, 20, 10, 5, and 10 mg mL -1 for Aspergillus fumigates, Curvularia lunata, Fusarium oxysporum, Gibberella moniliformis, and Penicillium chrysogenum, respectively. The strain showed several advantages, including the ability to survive under conditions similar to the gastrointestinal tract (low pH, bile salts, and antimicrobial susceptibility) and high levels of extracellular enzyme activities. The strain's growth patterns under various concentrations of H 2 O 2 and its scavenging properties towards hydroxyl radical (64.85%) and DPPH (84.97%) were also interesting properties. The antifungal, probiotic, and antioxidant properties of L. paraplantarum D3 may provide health benefits to consumers. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Cyclization Reaction of Acyl Thiourea Chitosan: Enhanced Antifungal Properties via Structural Optimization.

PubMed

Qin, Yukun; Liu, Weixiang; Xing, Ronge; Liu, Song; Li, Kecheng; Li, Pengcheng

2018-03-06

In this study, 3-methyl-1,2,4-triazolyl chitosan (MTACS) and 3-chloromethyl-1,2,4-triazolyl chitosan (CMTACS) were prepared via cyclization of acyl thiourea chitosan (TUCS). Their structures were confirmed by FT-IR, ¹H-NMR, elemental analysis, DSC, XRD, and SEM. The conformations were predicted using the Gaussian 09 program. Additionally, the antifungal properties of MTACS and CMTACS against Stemphylium solani weber ( S. solani ), Alternaria porri ( A. porri ), and Gloeosporium theae-sinensis ( G. theae-sinensis ) were assayed in vitro and ranged from 250 μg/mL to 1000 μg/mL. The results showed that MTACS and CMTACS exhibited enhanced inhibitory effect on the selected fungi compared to the original chitosan and TUCS. In particular, they displayed better antifungal activities against A. porri and G. theae-sinensis than that of the positive control, Triadimefon. The findings described here may lead to them being used as antifungal agents for crop protection.

Prevalence of Candida species in the buccal cavity of diabetic and non-diabetic individuals in and around Pondicherry.

PubMed

Lydia Rajakumari, M; Saravana Kumari, P

2016-12-01

The aim of the present study was to determine the prevalence of Candida in the buccal cavity of diabetic and non-diabetic individuals in and around Pondicherry, India and to analyse the antifungal susceptibility profile of the selected isolates. A total of 400 buccal samples, 200 each from diabetic and non-diabetic healthy individuals were included in the study. Sabouraud's dextrose agar was used for isolation of Candida species. Identification was performed through microscopy, germ tube test, sugar fermentation test, sugar assimilation test and by using Hichrome agar. Distinct and phenotypically representative colonies were selected and subjected to ITS analysis. In vitro antifungal susceptibility testing for the isolated Candida species was performed using E-test. Results revealed that the prevalence of Candida species in diabetic individuals was higher when compared with non-diabetic healthy individuals. The most predominantly isolated species in diabetic and non-diabetic individuals from buccal cavity was Candida albicans. C. tropicalis was predominant among the non-albicans Candida isolated from both diabetic and non-diabetic individuals. Among denture wearers C. glabrata was predominant. In vitro antifungal susceptibility testing shows that ketoconazole, fluconazole and itraconazole were effective against the isolated Candida species. The rate of candidal carriage in diabetic individuals is higher. Different species of Candida are present in the oral cavity of diabetic individuals. There may be a positive correlation between glycemic control and candidal colonization. In vitro antifungal susceptibility testing of Candia species are required for proper management and treatment of candidal infections. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Screening of antifungal agents using ethanol precipitation and bioautography of medicinal and food plants.

PubMed

Schmourlo, Gracilene; Mendonça-Filho, Ricardo R; Alviano, Celuta Sales; Costa, Sônia S

2005-01-15

In the search for bioactive compounds, bioautography and ethanol precipitation of macromolecules (proteins, polysaccharides, etc.) of plant aqueous extracts were associated in an antifungal screening. Thus, the supernatants, precipitates (obtained by ethanol precipitation) and aqueous extracts were investigated of medicinal and fruit bearing plants used against skin diseases by the Brazilian population. The agar diffusion and broth dilution methods were used to assess the activity against three fungi: Candida albicans, Trichophyton rubrum and Cryptococcus neoformans. The results, evaluated by the diameter of the inhibition zone of fungal growth, indicate that six plant species, among the 16 investigated, showed significant antifungal activity. The minimal inhibitory concentration (MIC) was determined on plant extracts that showed high efficacy against the tested microorganisms. The most susceptible yeast was Trichophyton rubrum and the best antifungal activity was shown by Xanthosoma sagittifolium supernatant. The bioautography was performed only for the aqueous extracts and supernatants of those plants that showed antifungal activity against Candida albicans and Cryptococcus neoformans, using n-butanol/acetic acid/water (BAW) 8:1:1 to develop silica gel TLC plates. Clear inhibition zones were observed for aqueous extracts of Schinus molle (R(f) 0.89) and Schinus terebinthifolius (R(f) 0.80) against Candida albicans, as for supernatant of Anacardium occidentale (R(f) 0.31) against Cryptococcus neoformans. The separation of macromolecules from metabolites, as in the case of Anacardium occidentale, Solanum sp. and Xanthosoma sagittifolium, enhances antifungal activity. In other cases, the antifungal activity is destroyed, as observed for Momordica charantia, Schinus molle and Schinus terebinthifolius.

Synthesis, Structure-Activity Relationships (SAR) and in Silico Studies of Coumarin Derivatives with Antifungal Activity

PubMed Central

de Araújo, Rodrigo S. A.; Guerra, Felipe Q. S.; de O. Lima, Edeltrudes; de Simone, Carlos A.; Tavares, Josean F.; Scotti, Luciana; Scotti, Marcus T.; de Aquino, Thiago M.; de Moura, Ricardo O.; Mendonça, Francisco J. B.; Barbosa-Filho, José M.

2013-01-01

The increased incidence of opportunistic fungal infections, associated with greater resistance to the antifungal drugs currently in use has highlighted the need for new solutions. In this study twenty four coumarin derivatives were screened in vitro for antifungal activity against strains of Aspergillus. Some of the compounds exhibited significant antifungal activity with MICs values ranging between 16 and 32 μg/mL. The structure-activity relationships (SAR) study demonstrated that O-substitutions are essential for antifungal activity. It also showed that the presence of a short aliphatic chain and/or electron withdrawing groups (NO2 and/or acetate) favor activity. These findings were confirmed using density functional theory (DFT), when calculating the LUMO density. In Principal Component Analysis (PCA), two significant principal components (PCs) explained more than 60% of the total variance. The best Partial Least Squares Regression (PLS) model showed an r2 of 0.86 and q2cv of 0.64 corroborating the SAR observations as well as demonstrating a greater probe N1 interaction for active compounds. Descriptors generated by TIP correlogram demonstrated the importance of the molecular shape for antifungal activity. PMID:23306152

A new cadmium(II) complex with bridging dithiolate ligand: Synthesis, crystal structure and antifungal activity study

NASA Astrophysics Data System (ADS)

Singh, Mahesh Kumar; Sutradhar, Sanjit; Paul, Bijaya; Adhikari, Suman; Laskar, Folguni; Butcher, Raymond J.; Acharya, Sandeep; Das, Arijit

2017-07-01

A new polymeric complex of Cd(II) with 1,1-dicyanoethylene- 2,2-dithiolate [ i-MNT2- = {S2C:C(CN)2}2- ] as a bridging ligand has been synthesized and characterized on the basis of spectroscopy and single-crystal X-ray diffraction analysis. Single crystal X-ray diffraction analysis reveals that the Cadmium (II) complex is six coordinated 1D polymeric in nature. Biological screening effects in vitro of the synthesized polymeric complex has been tested against five fungi Synchitrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans(ATCC10231), Trichophyton mentagrophytes by the disc diffusion method. In vitro antifungal screening indicates that the complex exhibits fungistatic and fungicidal antifungal activity whereas K2i-MNT.H2O became silent on Synchitrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans (ATCC10231), Trichophyton mentagrophytes.

Rational Discovery of (+) (S) Abscisic Acid as a Potential Antifungal Agent: a Repurposing Approach.

PubMed

Khedr, Mohammed A; Massarotti, Alberto; Mohamed, Maged E

2018-06-04

Fungal infections are spreading widely worldwide, and the types of treatment are limited due to the lack of diverse therapeutic agents and their associated side effects and toxicity. The discovery of new antifungal classes is vital and critical. We discovered the antifungal activity of abscisic acid through a rational drug design methodology that included the building of homology models for fungal chorismate mutases and a pharmacophore model derived from a transition state inhibitor. Ligand-based virtual screening resulted in some hits that were filtered using molecular docking and molecular dynamic simulations studies. Both in silico methods and in vitro antifungal assays were used as tools to select and validate the abscisic acid repurposing. Abscisic acid inhibition assays confirmed the inhibitory effect of abscisic acid on chorismate mutase through the inhibition of phenylpyruvate production. The repositioning of abscisic acid, the well-known and naturally occurring plant growth regulator, as a potential antifungal agent because of its suggested action as an inhibitor to several fungal chorismate mutases was the main result of this work.

Identification and quantification of antifungal compounds produced by lactic acid bacteria and propionibacteria.

PubMed

Le Lay, Céline; Coton, Emmanuel; Le Blay, Gwenaëlle; Chobert, Jean-Marc; Haertlé, Thomas; Choiset, Yvan; Van Long, Nicolas Nguyen; Meslet-Cladière, Laurence; Mounier, Jérôme

2016-12-19

Fungal growth in bakery products represents the most frequent cause of spoilage and leads to economic losses for industrials and consumers. Bacteria, such as lactic acid bacteria and propionibacteria, are commonly known to play an active role in preservation of fermented food, producing a large range of antifungal metabolites. In a previous study (Le Lay et al., 2016), an extensive screening performed both in vitro and in situ allowed for the selection of bacteria exhibiting an antifungal activity. In the present study, active supernatants against Penicillium corylophilum and Aspergillus niger were analyzed to identify and quantify the antifungal compounds associated with the observed activity. Supernatant treatments (pH neutralization, heating and addition of proteinase K) suggested that organic acids played the most important role in the antifungal activity of each tested supernatant. Different methods (HPLC, mass spectrometry, colorimetric and enzymatic assays) were then applied to analyze the supernatants and it was shown that the main antifungal compounds corresponded to lactic, acetic and propionic acids, ethanol and hydrogen peroxide, as well as other compounds present at low levels such as phenyllactic, hydroxyphenyllactic, azelaic and caproic acids. Based on these results, various combinations of the identified compounds were used to evaluate their effect on conidial germination and fungal growth of P. corylophilum and Eurotium repens. Some combinations presented the same activity than the bacterial culture supernatant thus confirming the involvement of the identified molecules in the antifungal activity. The obtained results suggested that acetic acid was mainly responsible for the antifungal activity against P. corylophilum and played an important role in E. repens inhibition. Copyright © 2016 Elsevier B.V. All rights reserved.

The anti-Malassezia furfur activity in vitro and in experimental dermatitis of six imidazole antifungal agents: bifonazole, clotrimazole, flutrimazole, ketoconazole, miconazole and sertaconazole.

PubMed

Van Gerven, F; Odds, F C

1995-01-01

Bifonazole, clotrimazole, flutrimazole, ketoconazole, miconazole and sertaconazole were tested for their activity against 23 isolates of Malassezia furfur by agar dilution in vitro. Topical formulations of the same agents were evaluated for efficacy against M. furfur skin infections in guinea pigs in vivo. The most potent inhibitor in vitro was ketoconazole (geometric mean minimum inhibitory concentration 0.51 microgram ml-1), followed by bifonazole (8.1 micrograms ml-1), then miconazole (14 micrograms ml-1), clotrimazole (15 micrograms ml-1) and flutrimazole (16 micrograms ml-1), with sertaconazole the least active (52 micrograms ml-1). In animal experiments involving three consecutive days of topical treatments, bifonazole 1% cream, clotrimazole 1% cream, flutrimazole 1% and 2% creams, ketoconazole 2% cream and shampoo and miconazole 2% cream all reduced M. furfur dermatitis lesion severity below that of untreated control animals; however, sertaconazole 2% gel and cream showed no reduction in lesion severity below control. The results confirm that ketoconazole is a more potent inhibitor of M. furfur in vitro than other topical antifungal agents of its class and suggest that sertaconazole is the least effective of such agents among those tested.

Synthesis, molecular modeling studies and evaluation of antifungal activity of a novel series of thiazole derivatives.

PubMed

Lino, Cleudiomar Inácio; Gonçalves de Souza, Igor; Borelli, Beatriz Martins; Silvério Matos, Thelma Tirone; Santos Teixeira, Iasmin Natália; Ramos, Jonas Pereira; Maria de Souza Fagundes, Elaine; de Oliveira Fernandes, Philipe; Maltarollo, Vinícius Gonçalves; Johann, Susana; de Oliveira, Renata Barbosa

2018-05-10

In the search for new antifungal agents, a novel series of fifteen hydrazine-thiazole derivatives was synthesized and assayed in vitro against six clinically important Candida and Cryptococcus species and Paracoccidioides brasiliensis. Eight compounds showed promising antifungal activity with minimum inhibitory concentration (MIC) values ranging from 0.45 to 31.2 μM, some of them being equally or more active than the drug fluconazole and amphotericin B. Active compounds were additionally tested for toxicity against human embryonic kidney (HEK-293) cells and none of them exhibited significant cytotoxicity, indicating high selectivity. Molecular modeling studies results corroborated experimental SAR results, suggesting their use in the design of new antifungal agents. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Antifungal potential of triphala churna ingredients against Aspergillus species associated with them during storage.

PubMed

Gautam, Ajay K; Avasthi, Shubhi; Sharma, Anu; Bhadauria, Rekha

2012-03-01

The present study describes the antifungal potential of fruit and powdered ingredients of triphala churna, i.e. Emblica officinalis (Garetn.) (Amla), Terminalia bellirica (Gaertn.) Roxb. (Baheda) and Terminalia chebula (Retz.) (Harada), collected from the market of Gwalior (M.P.), India. Water extracts of all the fruits and powdered samples were tested (in vitro) for their antifungal activities by poisoned food technique against different Aspergillus species (A. flavus, A. fumigatus, A. versicolor, A. terreus and A. niger) associated with them during storage. All extracts displayed varied levels i.e. very low to very high antifungal activities on four Aspergillus species. The aqueous extracts of fresh fruits (37.96 +/- 7.59%) was observed to be most effective than dry fruits (34.95 +/- 7.59%) and powder (25.07 +/- 6.05%). Terminalia chebula (fresh and dry) extracts were found most active against the four Aspergillus species with 49.15 and 40.8% inhibition, respectively. None of the extracts were found effective against the growth of A. niger. All fruits and powdered aqueous extracts were observed to be ineffective against the A. niger. The variability in antifungal activity of aqueous extracts in the present study may be useful to study the relationship between antifungal potential of herbal drugs and prevalence of fungal contaminant during their storage.

Anti-Candida albicans natural products, sources of new antifungal drugs: A review.

PubMed

Zida, A; Bamba, S; Yacouba, A; Ouedraogo-Traore, R; Guiguemdé, R T

2017-03-01

Candida albicans is the most prevalent fungal pathogen in humans. Due to the development of drug resistance, there is today a need for new antifungal agents for the efficient management of C. albicans infections. Therefore, we reviewed antifungal activity, mechanisms of action, possible synergism with antifungal drugs of all natural substances experimented to be efficient against C. albicans for future. An extensive and systematic review of the literature was undertaken and all relevant abstracts and full-text articles analyzed and included in the review. A total of 111 documents were published and highlighted 142 anti-C. albicans natural products. These products are mostly are reported in Asia (44.37%) and America (28.17%). According to in vitro model criteria, from the 142 natural substances, antifungal activity can be considered as important for 40 (28.20%) and moderate for 24 (16.90%). Sixteen products have their antifungal activity confirmed by in vivo gold standard experimentation. Microbial natural products, source of antifungals, have their antifungal mechanism well described in the literature: interaction with ergosterol (polyenes), inhibition 1,3-β-d-glucan synthase (Echinocandins), inhibition of the synthesis of cell wall components (chitin and mannoproteins), inhibition of sphingolipid synthesis (serine palmitoyltransferase, ceramide synthase, inositol phosphoceramide synthase) and inhibition of protein synthesis (sordarins). Natural products from plants mostly exert their antifungal effects by membrane-active mechanism. Some substances from arthropods are also explored to act on the fungal membrane. Interestingly, synergistic effects were found between different classes of natural products as well as between natural products and azoles. Search for anti-C. albicans new drugs is promising since the list of natural substances, which disclose activity against this yeast is today long. Investigations must be pursued not only to found more new anti

Antifungal activity of the essential oil of Angelica major against Candida, Cryptococcus, Aspergillus and dermatophyte species.

PubMed

Cavaleiro, Carlos; Salgueiro, Lígia; Gonçalves, Maria-José; Hrimpeng, Karnjana; Pinto, Jéssica; Pinto, Eugénia

2015-04-01

The composition and antifungal activity of the essential oil (EO) of Angelica major and its main components α-pinene and cis-β-ocimene against clinically relevant yeasts and moulds were evaluated. EO from the plant's aerial parts was obtained by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The oil showed high contents of α-pinene (21.8 %) and cis-β-ocimene (30.4 %). Minimum inhibitory concentrations (MICs) were measured according to the broth macrodilution protocols by the Clinical and Laboratory Standards Institute (CLSI). The EO, α-pinene and cis-β-ocimene displayed low MICs and minimum fungicidal concentrations (MFCs) against dermatophytes and Cryptococcus neoformans, with α-pinene being the most active. Regarding Candida species, the EO susceptibility profiles seem to be diverse and not correlated with fluconazole susceptibility patterns. Moreover, an inhibition of yeast-mycelium transition was demonstrated at sub-inhibitory concentrations of the EO, α-pinene and cis-β-ocimene in C. albicans. In addition, their haemolytic activity was low. The activity displayed by A. major EO and its main components associated with low cytotoxic activity confirms their potential as an antifungal agent against fungal species frequently implicated in human mycoses, particularly cryptococcosis and dermatophytosis. The association with commercial antifungal compounds could bring benefits, by the effect on germ tube formation, and be used in mucocutaneous candidiasis treatment.

Yeasts as important agents of onychomycosis: in vitro activity of propolis against yeasts isolated from patients with nail infection.

PubMed

Khosravi, Ali Reza; Shokri, Hojjatollah; Nikaein, Donya; Mansouri, Parvin; Erfanmanesh, Ahmad; Chalangari, Reza; Katalin, Martis

2013-01-01

The purposes of this study were to determine the frequency of the yeast species obtained from patients with clinical features of onychomycosis and the in vitro antifungal susceptibility of the yeast species to propolis. A prospective study was carried out at the Mycology Research Center in Iran from 2010 to 2011. Clinical diagnosis was performed by direct microscopic examination and culture. Different yeast species were identified by morphological and biochemical tests. An antifungal susceptibility test to fluconazole (FLU) and propolis by the broth microdilution method was performed on each isolate. One hundred and twenty-eight fungal isolates were obtained. The most prevalent fungi were yeasts (81, 63.2%), dermatophytes (36, 28.1%), and nondermatophyte fungi (11, 8.6%). Fingernails were more affected than toenails (65.4% vs. 19.8%, respectively). The most frequently found species was Candida albicans (38.5%), followed by Candida spp. (23.1%), C. tropicalis (10.8%), C. kefyr (6.2%), C. krusei (3.1%), Malassezia globosa (4.6%), M. slooffiae (4.6%), and M. pachydermatis (1.5%). Of all yeast isolates (65), seven showed resistance to FLU. The average MIC of propolis for FLU-susceptible isolates was 5.8 μg/mL, whereas this value was 12.25 μg/mL for FLU-resistant isolates. Our results proved that the propolis inhibits the growth of pathogenic yeasts and confirmed the efficiency of propolis as an anti-Candida and anti-Malassezia agent.

Small cysteine-rich antifungal proteins from radish: their role in host defense.

PubMed Central

Terras, F R; Eggermont, K; Kovaleva, V; Raikhel, N V; Osborn, R W; Kester, A; Rees, S B; Torrekens, S; Van Leuven, F; Vanderleyden, J

1995-01-01

Radish seeds have previously been shown to contain two homologous, 5-kD cysteine-rich proteins designated Raphanus sativus-antifungal protein 1 (Rs-AFP1) and Rs-AFP2, both of which exhibit potent antifungal activity in vitro. We now demonstrate that these proteins are located in the cell wall and occur predominantly in the outer cell layers lining different seed organs. Moreover, Rs-AFPs are preferentially released during seed germination after disruption of the seed coat. The amount of released proteins is sufficient to create a microenvironment around the seed in which fungal growth is suppressed. Both the cDNAs and the intron-containing genomic regions encoding the Rs-AFP preproteins were cloned. Transcripts (0.55 kb) hybridizing with an Rs-AFP1 cDNA-derived probe were present in near-mature and mature seeds. Such transcripts as well as the corresponding proteins were barely detectable in healthy uninfected leaves but accumulated systemically at high levels after localized fungal infection. The induced leaf proteins (designated Rs-AFP3 and Rs-AFP4) were purified and shown to be homologous to seed Rs-AFPs and to exert similar antifungal activity in vitro. A chimeric Rs-AFP2 gene under the control of the constitutive cauliflower mosaic virus 35S promoter conferred enhanced resistance to the foliar pathogen Alternaria longipes in transgenic tobacco. The term "plant defensins" is proposed to denote these defense-related proteins. PMID:7780308

Evaluation of Antifungal Effect of Silver Nanoparticles Against Microsporum canis, Trichophyton mentagrophytes and Microsporum gypseum

PubMed Central

Ayatollahi Mousavi, Seyyed Amin; Salari, Samira; Hadizadeh, Sanaz

2015-01-01

Background Dermatophytosis is the common cutaneous infections in humans and animals, which is caused by the keratinophylic fungus called dermatophytes. In recent years, drugs resistance in pathogenic fungi, including dermatophyte strains to the current antifungals have been increased. Objectives The aim of this study was to evaluate the antifungal efficacy of AgNPs against Microsporum canis, Trichophyton mentagrophytes , and Microsporum gypseum. Materials and Methods The antifungal susceptibility of nanosilver particles compared with griseofulvin (GR). Its efficacy was investigated against three strains of dermatophytes by both agar dilution and broth microdilution test (BMD). Results The average minimum inhibitory concentration (MIC) AgNPs on M. canis, T. mentagrophytes and M. gypseum were 200, 180 and 170 μg.mL-1, respectively. Whereas these strains showed MIC of 25, 100 and 50 μg.mL-1 for GR. Conclusions Our finding indicated that the AgNPs was less active than GR but it had anti-dermatophytic effect. PMID:28959308

Yeast Colonization and Drug Susceptibility Pattern in the Pediatric Patients With Neutropenia

PubMed Central

Haddadi, Pedram; Zareifar, Soheila; Badiee, Parisa; Alborzi, Abdolvahab; Mokhtari, Maral; Zomorodian, Kamiar; Pakshir, Keyvan; Jafarian, Hadis

2014-01-01

Background: Pediatric patients with neutropenia are vulnerable to invasive Candida infections. Candida is the primary cause of fungal infections, particularly in immunosuppressed patients. Candida albicans has been the most common etiologic agent of these infections, affecting 48% of patients Objectives: The aim of this study was to identify Candida spp. isolated from children with neutropenia and determine the antifungal susceptibility pattern of the isolated yeasts. Patients and Methods: In this study 188 children with neutropenia were recruited, fungal surveillance cultures were carried out on nose, oropharynx, stool, and urine samples. Identification of Candida strains was performed using germ tube and chlamydospore production tests on an API 20 C AUX system. Susceptibility testing on seven antifungal agents was performed using the agar-based E-test method. Results: A total of 229 yeasts were isolated. Among those, C. albicans was the most common species followed by C. krusei, C. parapsilosis, C. glabrata, C. tropicalis, C. famata, C. dubliniensis, C. kefyr, and other Candida species. C. glabrata was the most resistant isolated yeasts, which was 70% resistant to fluconazole and 50% to itraconazole, 7.5% to amphotericin B and 14% to ketoconazole. All the tested species were mostly sensitive to caspofungin. Conclusions: Knowledge about the susceptibility patterns of colonized Candida spp. can be helpful for clinicians to manage pediatric patients with neutropenia. In this study, caspofungin was the most effective antifungal agent against the colonized Candida spp. followed by conventional amphotericin B. PMID:25485060

In silico and in vitro screening to identify structurally diverse non-azole CYP51 inhibitors as potent antifungal agent.

PubMed

Singh, Aarti; Paliwal, Sarvesh Kumar; Sharma, Mukta; Mittal, Anupama; Sharma, Swapnil; Sharma, Jai Prakash

2016-01-01

The problem of resistance to azole class of antifungals is a serious cause of concern to the medical fraternity and thus there is an urgent need to identify non-azole scaffolds with high affinity for lanosterol 14α-demethylase (CYP51). In view of this we have attempted to identify novel non-azole CYP51 inhibitors through the application of pharmacophore based virtual screening and in vitro evaluation. A rigorously validated pharmacophore model comprising of 2 hydrogen bond acceptor and 2 hydrophobic features has been developed and used to mine NCI database. Out of 265 retrieved hits, NSC 1215 and 1520 have been chosen on the basis of Lipinski's rule of five, fit and estimated values. Both the hits were docked into the active site of CYP51. In view of high fit value and CDocker score, NSC 1215 and 1520 have been subjected to in vitro microbiological assay. The result reveals that NSC 1215 and 1520 are active against Candida albicans, Candida parapsilosis, Candida tropicalis, and Aspergillus niger. In addition to this the absorption characteristics of both the hits have also been determined using the rat sac technique and permeation in order of NSC 1520>NSC 1215 has been observed. Copyright © 2015 Elsevier Inc. All rights reserved.

In Vitro Activities of Four Novel Triazoles against Scedosporium spp.

PubMed Central

Carrillo, A. J.; Guarro, J.

2001-01-01

In order to develop new approaches to the treatment of the severe and usually fatal infections caused by Scedosporium spp., the in vitro antifungal activities of four novel triazoles (posaconazole, ravuconazole, voriconazole, and UR-9825) and some current antifungals (amphotericin B, ketoconazole, itraconazole, and nystatin) were determined. The latter group was clearly ineffective against the two species tested. The four new antifungals showed activity against Scedosporium apiospermum, and UR-9825 and voriconazole were active against S. prolificans. PMID:11408242

Biofilm-forming capacity of blood-borne Candida albicans strains and effects of antifungal agents.

PubMed

Turan, Hanni; Demirbilek, Müge

Infections related to Candida albicans biofilms and subsequent antifungal resistance have become more common with the increased use of indwelling medical devices. Regimens for preventing fungal biofilm formation are needed, particularly in high-risk patients. In this study, we investigated the biofilm formation rate of multiple strains of Candida albicans (n=162 clinical isolates), their antifungal susceptibility patterns, and the efficacy of certain antifungals for preventing biofilm formation. Biofilm formation was graded using a modified Christensen's 96-well plate method. We further analyzed 30 randomly chosen intense biofilm-forming isolates using the XTT method. Minimum biofilm inhibition concentrations (MBIC) of caspofungin, micafungin, anidulafungin, fluconazole, voriconazole, posaconazole, itraconazole, and amphotericin B were determined using the modified Calgary biofilm method. In addition, the inhibitory effects of antifungal agents on biofilm formation were investigated. Our study showed weak, moderate, and extensive biofilm formation in 29% (n=47), 38% (n=61), and 23% (n=37) of the isolates, respectively. We found that echinocandins had the lowest MBIC values and that itraconazole inhibited biofilm formation in more isolates (26/32; 81.3%) than other tested agents. In conclusion, echinocandins were most effective against formed biofilms, while itraconazole was most effective for preventing biofilm formation. Standardized methods are needed for biofilm antifungal sensitivity tests when determining the treatment and prophylaxis of C. albicans infections. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Identification and Antifungal Susceptibility Testing of Candida Species: A Comparison of Vitek-2 System with Conventional and Molecular Methods.

PubMed

Kaur, Ravinder; Dhakad, Megh Singh; Goyal, Ritu; Haque, Absarul; Mukhopadhyay, Gauranga

2016-01-01

Candida infection is a major cause of morbidity and mortality in immunocompromised patients; an accurate and early identification is a prerequisite need to be taken as an effective measure for the management of patients. The purpose of this study was to compare the conventional identification of Candida species with identification by Vitek-2 system and the antifungal susceptibility testing (AST) by broth microdilution method with Vitek-2 AST system. A total of 172 Candida isolates were subjected for identification by the conventional methods, Vitek-2 system, restriction fragment length polymorphism, and random amplified polymorphic DNA analysis. AST was carried out as per the Clinical and Laboratory Standards Institute M27-A3 document and by Vitek-2 system. Candida albicans (82.51%) was the most common Candida species followed by Candida tropicalis (6.29%), Candida krusei (4.89%), Candida parapsilosis (3.49%), and Candida glabrata (2.79%). With Vitek-2 system, of the 172 isolates, 155 Candida isolates were correctly identified, 13 were misidentified, and four were with low discrimination. Whereas with conventional methods, 171 Candida isolates were correctly identified and only a single isolate of C. albicans was misidentified as C. tropicalis . The average measurement of agreement between the Vitek-2 system and conventional methods was >94%. Most of the isolates were susceptible to fluconazole (88.95%) and amphotericin B (97.67%). The measurement of agreement between the methods of AST was >94% for fluconazole and >99% for amphotericin B, which was statistically significant ( P < 0.01). The study confirmed the importance and reliability of conventional and molecular methods, and the acceptable agreements suggest Vitek-2 system an alternative method for speciation and sensitivity testing of Candida species infections.

Do bacteria isolated from ICU patients 'ESKAPE' antibiotic treatment? In vitro susceptibility of the Enterobacteriaceae family to tigecycline.

PubMed

Talaga-Ćwiertnia, Katarzyna; Krzyściak, Paweł; Bulanda, Małgorzata

2017-01-01

Enterobacteriaceae are currently causing the majority of healthcare-associated infections (HAI) and simultaneously expressing increasing levels of antibiotic resistance. The purpose of this study is to assess the in vitro sensitivity of MDR strains from the family Enterobacteriaceae to tigecycline in relation to their origin from patients hospitalized in intensive care units (ICUs) and non-ICUs. The study involved 156 clinically significant strains of the Enterobacteriaceae family isolated from patients with complicated intraabdominal infections (cIAIs) and/or complicated skin and skin structure infections (cSSSIs) hospitalized in ICUs and other surgical departments. Tigecycline MICs were determined by Etest. The highest percentage of tigecycline non-susceptible (intermediate + resistant strains) in vitro strains among the Enterobacteriaceae species were observed for Serratia spp. 77.3%, followed by Citrobacter spp. (76.9%) and Enterobacter spp. (70%); whereas K. pneumoniae and E. coli showed 73-73.8% tigecycline susceptibility rates. Tigecycline demonstrates a high level of antimicrobial in vitro activity when tested against E. coli and K. pneumoniae, even those with the ESBL-phenotype. Tigecycline retained activity against merely 22-30% of Enterobacter, Citrobacter and Serratia genera.

An Azole-Tolerant Endosomal Trafficking Mutant of Candida albicans Is Susceptible to Azole Treatment in a Mouse Model of Vaginal Candidiasis.

PubMed

Peters, Brian M; Luna-Tapia, Arturo; Tournu, Hélène; Rybak, Jeffrey M; Rogers, P David; Palmer, Glen E

2017-06-01

We recently reported that a Candida albicans endosomal trafficking mutant continues to grow after treatment with the azole antifungals. Herein, we report that the vps21 Δ/Δ mutant does not have a survival advantage over wild-type isolates after fluconazole treatment in a mouse model of vaginal candidiasis. Furthermore, loss of VPS21 does not synergize with established mechanisms of azole resistance, such as overexpression of efflux pumps or of Erg11p, the target enzyme of the azoles. In summary, although loss of VPS21 function enhances C. albicans survival after azole treatment in vitro , it does not seem to affect azole susceptibility in vivo . Copyright © 2017 American Society for Microbiology.

Metal based new triazoles: Their synthesis, characterization and antibacterial/antifungal activities

NASA Astrophysics Data System (ADS)

Sumrra, Sajjad H.; Chohan, Zahid H.

2012-12-01

A series of new triazoles and their oxovanadium(IV) complexes have been synthesized, characterized and evaluated for antibacterial/antifungal properties. The new Schiff bases ligands (L1)-(L5) were prepared by the condensation reaction of 3,5-diamino-1,2,4-triazole with 2-hydroxy-1-naphthaldehyde, pyrrole-2-carboxaldehyde, pyridine-2-carboxaldehyde, 2-acetyl pyridine and 2-methoxy benzaldehyde. The structures of the ligands have been established on the basis of their physical, spectral (IR, 1H and 13C NMR and mass spectrometry) and elemental analytical data. The prepared ligands were used to synthesize their oxovanadium(IV) complexes (1)-(5) which were also characterized by their physical, spectral and analytical data and proposed to have a square pyramidal geometry. The ligands and their complexes were screened for in vitro antibacterial activity against six bacterial species such as, Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus, and Bacillus subtilis and for in vitro antifungal activity against six fungal strains, Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, and Candida glabrata. Cytotoxic nature of the compounds was also reported using brine shrimp bioassay method against Artemia salina.

In vitro antimicrobial activities of animal-used quinoxaline 1,4-di-N-oxides against mycobacteria, mycoplasma and fungi.

PubMed

Zhao, Yan; Cheng, Guyue; Hao, Haihong; Pan, Yuanhu; Liu, Zhenli; Dai, Menghong; Yuan, Zonghui

2016-09-06

The quinoxaline 1,4-di-N-oxides (QdNOs) were known as potent antibacterial agents. For the purpose of evaluating the bioactivity of existing animal-used QdNOs drugs against representative pathogenic microorganism, the representative drugs of quinoxalines including cyadox, mequindox, quinocetone and their metabolites were submitted to the in vitro evaluation for antituberculosis, antimycoplasma, antifungal and antiviral activities. In antituberculosis assays, the prototype compounds were active (MIC = 4 ~ 8 μg/mL) against Mycobacterium tuberculosis H37Rv and M. bovis. Combined antimicrobial susceptibility test indicated that cyadox, mequindox and quinocetone combined with rifampicin had additive effect against M. tuberculosis complex with Fractional Inhibitory Concentration Index (FIC) of 0.75. Results of antifungal assays showed that quinocetone was active against Microsporum canis with MIC of 8 μg/mL. Antimycoplasma screening showed a generally good activity of quinocetone against Mycoplasma gallisepticum and Mycoplasma hyopneumoniae, with MIC between 8 and 16 μg/mL. As shown from the combined antimicrobial susceptibility test, cyadox, mequindox and quinocetone combined with tetracycline had additive effect against Mycoplasma gallisepticum with FIC of 0.75. These compounds were also submitted to antiviral assay against infectious bursal disease virus, porcine reproductive and respiratory syndrome virus, porcine parvovirus and classical swine fever virus. The results obtained showed that these QdNOs and their metabolites have no inhibitory activity against these viruses in vitro. QdNOs exhibit antimicrobial activities against mycobacteria, mycoplasma and fungi. This study gives new insight in further application of QdNOs and offers a way to promote the healthcare of animal husbandry.

In Vitro Susceptibility of Sporothrix brasiliensis to Essential Oils of Lamiaceae Family.

PubMed

Waller, Stefanie Bressan; Madrid, Isabel Martins; Silva, Anna Luiza; Dias de Castro, Luciana Laitano; Cleff, Marlete Brum; Ferraz, Vanny; Meireles, Mário Carlos Araújo; Zanette, Régis; de Mello, João Roberto Braga

2016-12-01

This study evaluated the chemical, cytotoxic and anti-Sporothrix brasiliensis properties of commercial essential oils of rosemary (Rosmarinus officinalis L.), oregano (Origanum vulgare L.) and marjoram (Origanum majorana L.). Chemical composition of the oils was identified through gas chromatography with flame ionization detector, and cytotoxicity was performed through MTT assay in VERO cell line. Anti-S. brasiliensis activity was performed according to the CLSI M38-A2 guidelines using isolates obtained from cats and dogs. The major compounds found were carvacrol in the oregano oil (73.9 %) and 1,8-cineole in rosemary and marjoram oils (49.4 and 20.9 %, respectively). All S. brasiliensis isolates were susceptible to the plant oils, including itraconazole-resistant ones. Marjoram and rosemary oils showed MIC 90 of 0.56 and 1.12 mg ml -1 , and MFC 90 of 4.5 and 9 mg ml -1 , respectively. For oregano oil, a strong antifungal activity was observed with MIC 90 and MFC 90 values ≤0.07 mg ml -1 . The weakest cytotoxicity was observed for rosemary oil. Further studies should be undertaken to evaluate the safety and efficacy of these essential oils in sporotrichosis.

In vitro antifungal effect of black cumin seed quinones against dairy spoilage yeasts at different acidity levels.

PubMed

Halamova, Katerina; Kokoska, Ladislav; Flesar, Jaroslav; Sklenickova, Olga; Svobodova, Blanka; Marsik, Petr

2010-12-01

The antiyeast activity of the black cumin seed (Nigella sativa) quinones dithymoquinone, thymohydroquinone (THQ), and thymoquinone (TQ) were evaluated in vitro with a broth microdilution method against six dairy spoilage yeast species. Antifungal effects of the quinones were compared with those of preservatives commonly used in milk products (calcium propionate, natamycin, and potassium sorbate) at two pH levels (4.0 and 5.5). THQ and TQ possessed significant antiyeast activity and affected the growth of all strains tested at both pH levels, with MICs ranging from 8 to 128 μg/ml. With the exception of the antibiotic natamycin, the inhibitory effects of all food preservatives against the yeast strains tested in this study were strongly affected by differences in pH, with MICs of ≥16 and ≥512 μg/ml at pH 4.0 and 5.5, respectively. These findings suggest that HQ and TQ are effective antiyeast agents that could be used in the dairy industry as chemical preservatives of natural origin.

Viridepyronone, a new antifungal 6-substituted 2H-pyran-2-one produced by Trichoderma viride.

PubMed

Evidente, Antonio; Cabras, Annalisa; Maddau, Lucia; Serra, Salvatorica; Andolfi, Anna; Motta, Andrea

2003-11-19

A new antifungal 6-substituted 2H-pyran-2-one, named viridepyronone, has been isolated from a cultural filtrate of a strain of Trichoderma viride showing antagonistic activity in vitro toward Sclerotium rolfsii, which is the causal agent of crown and stem rot of artichoke. Viridepyronone was characterized as 6-(4-oxopentyl)-2H-pyran-2-one 2 with spectroscopic methods. Bioassays showed that viridepyronone had a good antifungal activity against S. rolfsii, and its minimum inhibitory concentration (over 90% inhibition) was found to be 196 microg/mL. This is the first report of viridepyronone produced by any species of fungi.

Design and formulation of a topical hydrogel integrating lemongrass-loaded nanosponges with an enhanced antifungal effect: in vitro/in vivo evaluation.

PubMed

Aldawsari, Hibah M; Badr-Eldin, Shaimaa M; Labib, Gihan S; El-Kamel, Amal H

2015-01-01

Lemongrass oil (LGO) is a volatile oil extracted from the leaves of Cymbopogon citratus that has become one of the most important natural oils in the pharmaceutical industry because of its diverse pharmacologic and clinical effects. However, LGO suffers from low aqueous solubility, which could lead to a reduced effect. Moreover, the instability of its major active constituent, citral, could lead to volatilization, reaction with other formulation ingredients, and consequently, skin irritation. To surmount these problems, this research aims to formulate lemongrass-loaded ethyl cellulose nanosponges with a topical hydrogel with an enhanced antifungal effect and decreased irritation. The minimal inhibitory concentration and minimal fungicidal concentration of LGO against Candida albicans strain ATC 100231, determined using the broth macrodilution method, were found to be 2 and 8 μL/mL, respectively. The emulsion solvent evaporation technique was used for the preparation of the nanosponges. The nanosponge dispersions were then integrated into carbopol hydrogels (0.4%). Nine formulations were prepared based on a 32 full factorial design employing the ethyl cellulose:polyvinyl alcohol ratio and stirring rate as independent variables. The prepared formulations were evaluated for particle size, citral content, and in vitro release. Results revealed that all the nanosponge dispersions were nanosized, with satisfactory citral content and sustained release profiles. Statistical analysis revealed that both ethyl cellulose:polyvinyl alcohol ratio and stirring rate have significant effects on particle size and percentage released after 6 hours; however, the effect of the stirring rate was more prominent on both responses. The selected hydrogel formulation, F9, was subjected to surface morphological investigations, using scanning and transmission electron microscopy, where results showed that the nanosponges possess a spherical uniform shape with a spongy structure, the integrity

Design and formulation of a topical hydrogel integrating lemongrass-loaded nanosponges with an enhanced antifungal effect: in vitro/in vivo evaluation

PubMed Central

Aldawsari, Hibah M; Badr-Eldin, Shaimaa M; Labib, Gihan S; El-Kamel, Amal H

2015-01-01

Lemongrass oil (LGO) is a volatile oil extracted from the leaves of Cymbopogon citratus that has become one of the most important natural oils in the pharmaceutical industry because of its diverse pharmacologic and clinical effects. However, LGO suffers from low aqueous solubility, which could lead to a reduced effect. Moreover, the instability of its major active constituent, citral, could lead to volatilization, reaction with other formulation ingredients, and consequently, skin irritation. To surmount these problems, this research aims to formulate lemongrass-loaded ethyl cellulose nanosponges with a topical hydrogel with an enhanced antifungal effect and decreased irritation. The minimal inhibitory concentration and minimal fungicidal concentration of LGO against Candida albicans strain ATC 100231, determined using the broth macrodilution method, were found to be 2 and 8 μL/mL, respectively. The emulsion solvent evaporation technique was used for the preparation of the nanosponges. The nanosponge dispersions were then integrated into carbopol hydrogels (0.4%). Nine formulations were prepared based on a 32 full factorial design employing the ethyl cellulose:polyvinyl alcohol ratio and stirring rate as independent variables. The prepared formulations were evaluated for particle size, citral content, and in vitro release. Results revealed that all the nanosponge dispersions were nanosized, with satisfactory citral content and sustained release profiles. Statistical analysis revealed that both ethyl cellulose:polyvinyl alcohol ratio and stirring rate have significant effects on particle size and percentage released after 6 hours; however, the effect of the stirring rate was more prominent on both responses. The selected hydrogel formulation, F9, was subjected to surface morphological investigations, using scanning and transmission electron microscopy, where results showed that the nanosponges possess a spherical uniform shape with a spongy structure, the integrity

Trehalose pathway as an antifungal target.

PubMed

Perfect, John R; Tenor, Jennifer L; Miao, Yi; Brennan, Richard G

2017-02-17

With an increasing immunocompromised population which is linked to invasive fungal infections, it is clear that our present 3 classes of antifungal agents may not be sufficient to provide optimal management to these fragile patients. Furthermore, with widespread use of antifungal agents, drug-resistant fungal infections are on the rise. Therefore, there is some urgency to develop the antifungal pipeline with the goal of new antifungal agent discovery. In this review, a simple metabolic pathway, which forms the disaccharide, trehalose, will be characterized and its potential as a focus for antifungal target(s) explained. It possesses several important features for development of antifungal agents. First, it appears to have fungicidal characteristics and second, it is broad spectrum with importance across both ascomycete and basidiomycete species. Finally, this pathway is not found in mammals so theoretically specific inhibitors of the trehalose pathway and its enzymes in fungi should be relatively non-toxic for mammals. The trehalose pathway and its critical enzymes are now in a position to have directed antifungal discovery initiated in order to find a new class of antifungal drugs.

Changes in In Vitro Susceptibility Patterns of Aspergillus to Triazoles and Correlation With Aspergillosis Outcome in a Tertiary Care Cancer Center, 1999-2015.

PubMed

Heo, Sang Taek; Tatara, Alexander M; Jiménez-Ortigosa, Cristina; Jiang, Ying; Lewis, Russell E; Tarrand, Jeffrey; Tverdek, Frank; Albert, Nathaniel D; Verweij, Paul E; Meis, Jacques F; Mikos, Antonios G; Perlin, David S; Kontoyiannis, Dimitrios P

2017-07-15

Azole-resistant aspergillosis in high-risk patients with hematological malignancy or hematopoietic stem cell transplantation (HSCT) is a cause of concern. We examined changes over time in triazole minimum inhibitory concentrations (MICs) of 290 sequential Aspergillus isolates recovered from respiratory sources during 1999-2002 (before introduction of the Aspergillus-potent triazoles voriconazole and posaconazole) and 2003-2015 at MD Anderson Cancer Center. We also tested for polymorphisms in ergosterol biosynthetic genes (cyp51A, erg3C, erg1) in the 37 Aspergillus fumigatus isolates isolated from both periods that had non-wild-type (WT) MICs. For the 107 patients with hematologic cancer and/or HSCT with invasive pulmonary aspergillosis, we correlated in vitro susceptibility with 42-day mortality. Non-WT MICs were found in 37 (13%) isolates and was only low level (MIC <8 mg/L) in all isolates. Higher-triazole MICs were more frequent in the second period and were Aspergillus-species specific, and only encountered in A. fumigatus. No polymorphisms in cyp51A, erg3C, erg1 genes were identified. There was no correlation between in vitro MICs with 42-day mortality in patients with invasive pulmonary aspergillosis, irrespective of antifungal treatment. Asian race (odds ratio [OR], 20.9; 95% confidence interval [CI], 2.5-173.5; P = .005) and azole exposure in the prior 3 months (OR, 9.6; 95% CI, 1.9-48.5; P = .006) were associated with azole resistance. Non-WT azole MICs in Aspergillus are increasing and this is associated with prior azole exposure in patients with hematologic cancer or HSCT. However, no correlation of MIC with outcome of aspergillosis was found in our patient cohort. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

In Vitro Susceptibilities of Shigella flexneri and Streptococcus pyogenes to Inner Gel of Aloe barbadensis Miller

PubMed Central

Ferro, Valerie A.; Bradbury, Fiona; Cameron, Pamela; Shakir, Eisin; Rahman, Sabita R.; Stimson, William H.

2003-01-01

Aloe barbadensis Miller (or Aloe vera) has widespread use in health products, and despite numerous reports on the whole plant, little work has been performed on the inner gel, which has been used extensively in these products. This report describes the in vitro susceptibilities of two bacteria to this component. PMID:12604556

Antifungal Activity of Amphotericin B Conjugated to Nanosized Magnetite in the Treatment of Paracoccidioidomycosis

PubMed Central

Saldanha, Camila Arruda; Garcia, Mônica Pereira; Iocca, Diego Cesar; Rebelo, Luciana Guilherme; Souza, Ana Camila Oliveira; Bocca, Anamélia Lorenzetti; Almeida Santos, Maria de Fátima Menezes; Morais, Paulo Cesar; Azevedo, Ricardo Bentes

2016-01-01

This study reports on in vitro and in vivo tests that sought to assess the antifungal activity of a newly developed magnetic carrier system comprising amphotericin B loaded onto the surface of pre-coated (with a double-layer of lauric acid) magnetite nanoparticles. The in vitro tests compared two drugs; i.e., this newly developed form and free amphotericin B. We found that this nanocomplex exhibited antifungal activity without cytotoxicity to human urinary cells and with low cytotoxicity to peritoneal macrophages. We also evaluated the efficacy of the nanocomplex in experimental paracoccidioidomycosis. BALB/c mice were intratracheally infected with Paracoccidioides brasiliensis and treated with the compound for 30 or 60 days beginning the day after infection. The newly developed amphotericin B coupled with magnetic nanoparticles was effective against experimental paracoccidioidomycosis, and it did not induce clinical, biochemical or histopathological alterations. The nanocomplex also did not induce genotoxic effects in bone marrow cells. Therefore, it is reasonable to believe that amphotericin B coupled to magnetic nanoparticles and stabilized with bilayer lauric acid is a promising nanotool for the treatment of the experimental paracoccidioidomycosis because it exhibited antifungal activity that was similar to that of free amphotericin B, did not induce adverse effects in therapeutic doses and allowed for a reduction in the number of applications. PMID:27303789

In vivo application of a small molecular weight antifungal protein of Penicillium chrysogenum (PAF)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palicz, Zoltán; Jenes, Ágnes; Gáll, Tamás

2013-05-15

The antifungal protein of Penicillium chrysogenum (PAF) inhibits the growth of important pathogenic filamentous fungi, including members of the Aspergillus family and some dermatophytes. Furthermore, PAF was proven to have no toxic effects on mammalian cells in vitro. To prove that PAF could be safely used in therapy, experiments were carried out to investigate its in vivo effects. Adult mice were inoculated with PAF intranasally in different concentrations, up to 2700 μg·kg{sup −1} daily, for 2 weeks. Even at the highest concentration – a concentration highly toxic in vitro for all affected molds – used, animals neither died due tomore » the treatment nor were any side effects observed. Histological examinations did not find pathological reactions in the liver, in the kidney, and in the lungs. Mass spectrometry confirmed that a measurable amount of PAF was accumulated in the lungs after the treatment. Lung tissue extracts from PAF treated mice exerted significant antifungal activity. Small-animal positron emission tomography revealed that neither the application of physiological saline nor that of PAF induced any inflammation while the positive control lipopolysaccharide did. The effect of the drug on the skin was examined in an irritative dermatitis model where the change in the thickness of the ears following PAF application was found to be the same as in control and significantly less than when treated with phorbol-12-myristate-13-acetate used as positive control. Since no toxic effects of PAF were found in intranasal application, our result is the first step for introducing PAF as potential antifungal drug in therapy. - Highlights: • PAF, the antifungal protein of Penicillium chrysogenum, was not toxic in mice. • Its intranasal application didn't induce pathological reactions in the lung. • PAF retained its antifungal activity in lung extracts. • Its application on the skin did not cause inflammation.« less

New azole antifungals. 2. Synthesis and antifungal activity of heterocyclecarboxamide derivatives of 3-amino-2-aryl-1-azolyl-2-butanol.

PubMed

Bartroli, J; Turmo, E; Algueró, M; Boncompte, E; Vericat, M L; Conte, L; Ramis, J; Merlos, M; García-Rafanell, J; Forn, J

1998-05-21