Science.gov

Sample records for agar antifungal susceptibility

  1. In vitro antifungal susceptibility testing of Scopulariopsis brevicaulis strains using agar diffusion method.

    PubMed

    Skóra, Magdalena; Macura, Anna B

    2011-01-01

    The genus Scopulariopsis is a common soil saprotroph and has been isolated from air, organic waste and also from plant, animal and human tissues. Scopulariopsis has mainly been associated in humans with superficial mycoses, but it has also been described as the cause of subcutaneous and invasive infections. The most common aetiological agent of infections in humans is Scopulariopsis brevicaulis. This species has been reported to be resistant in vitro to broad-spectrum antifungal agents available today. The aim of the study was to establish in vitro antifungal susceptibility of 35 S. brevicaulis strains against amphotericin B (AMB), flucytosine (FC), caspofungin (CAS), terbinafine (TER), ciclopirox (CIC), voriconazole (VOR), clotrimazole (CTR), miconazole (MCZ), econazole (ECO), ketoconazole (KET), itraconazole (ITR), and fluconazole (FLU). Antifungal susceptibility tests were evaluated by an agar diffusion method (Neo-Sensitabs, Rosco, Denmark). AMB, FC, CAS, ITR and FLU showed no antifungal activity against S. brevicaulis. TER, CIC, CTR, KET, VOR, ECO, and MCZ revealed inhibitory activity for S. brevicaulis, but it varied for each of the drugs. The best antifungal effect was observed for TER and CIC. All isolates had large inhibition zones for TER and CIC. CTR was also inhibitory for all tested S. brevicaulis isolates, but the diameters of inhibition zones were smaller than for TER and CIC. Nearly 89% isolates showed inhibition zones for KET and the mean diameter of the inhibition zone was comparable to CTR. The least antifungal activity exhibited VQR, ECO and MCZ. Because of the multiresistance of S. brevicaulis, infections due to this species may not respond to particular antifungal treatment and other therapeutic approaches should be considered, e.g., combined therapy and/or surgery. PMID:21682097

  2. In vitro antifungal susceptibility testing of Scopulariopsis brevicaulis strains using agar diffusion method.

    PubMed

    Skóra, Magdalena; Macura, Anna B

    2011-01-01

    The genus Scopulariopsis is a common soil saprotroph and has been isolated from air, organic waste and also from plant, animal and human tissues. Scopulariopsis has mainly been associated in humans with superficial mycoses, but it has also been described as the cause of subcutaneous and invasive infections. The most common aetiological agent of infections in humans is Scopulariopsis brevicaulis. This species has been reported to be resistant in vitro to broad-spectrum antifungal agents available today. The aim of the study was to establish in vitro antifungal susceptibility of 35 S. brevicaulis strains against amphotericin B (AMB), flucytosine (FC), caspofungin (CAS), terbinafine (TER), ciclopirox (CIC), voriconazole (VOR), clotrimazole (CTR), miconazole (MCZ), econazole (ECO), ketoconazole (KET), itraconazole (ITR), and fluconazole (FLU). Antifungal susceptibility tests were evaluated by an agar diffusion method (Neo-Sensitabs, Rosco, Denmark). AMB, FC, CAS, ITR and FLU showed no antifungal activity against S. brevicaulis. TER, CIC, CTR, KET, VOR, ECO, and MCZ revealed inhibitory activity for S. brevicaulis, but it varied for each of the drugs. The best antifungal effect was observed for TER and CIC. All isolates had large inhibition zones for TER and CIC. CTR was also inhibitory for all tested S. brevicaulis isolates, but the diameters of inhibition zones were smaller than for TER and CIC. Nearly 89% isolates showed inhibition zones for KET and the mean diameter of the inhibition zone was comparable to CTR. The least antifungal activity exhibited VQR, ECO and MCZ. Because of the multiresistance of S. brevicaulis, infections due to this species may not respond to particular antifungal treatment and other therapeutic approaches should be considered, e.g., combined therapy and/or surgery.

  3. 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

  4. Antifungal susceptibility testing.

    PubMed Central

    Rex, J H; Pfaller, M A; Rinaldi, M G; Polak, A; Galgiani, J N

    1993-01-01

    Unlike antibacterial susceptibility testing, reliable antifungal susceptibility testing is still largely in its infancy. Many methods have been described, but they produce widely discrepant results unless such factors as pH, inoculum size, medium formulation, incubation time, and incubation temperature are carefully controlled. Even when laboratories agree upon a common method, interlaboratory agreement may be poor. As a result of numerous collaborative projects carried out both independently and under the aegis of the Subcommittee on Antifungal Susceptibility Testing of the National Committee for Clinical Laboratory Standards, the effects of varying these factors have been extensively studied and a standard method which minimizes interlaboratory variability during the testing of Candida spp. and Cryptococcus neoformans has been proposed. This review summarizes this work, reviews the strengths and weaknesses of the proposed susceptibility testing standard, and identifies directions for future work. PMID:8269392

  5. Antifungal susceptibility of Malassezia pachydermatis biofilm.

    PubMed

    Figueredo, Luciana A; Cafarchia, Claudia; Otranto, Domenico

    2013-11-01

    Antifungal resistance has been associated with biofilm formation in many microorganisms, but not yet in Malassezia pachydermatis. This saprophytic yeast can cause otitis and dermatitis in dogs and has emerged as an important human pathogen, responsible for systemic infections in neonates in intensive care units. This study aims to evaluate the in vitro antifungal susceptibility of M. pachydermatis strains, in both their planktonic and sessile forms, to fluconazole, miconazole, ketoconazole, itraconazole, posaconazole, terbinafine and voriconazole using the XTT assay and Clinical and Laboratory Standards Institute (CLSI) microdilution method. The minimum inhibitory concentration (MIC) values recorded for each drug were significantly higher for sessile cells relative to planktonic cells to the extent that ≥ 90% of M. pachydermatis strains in their sessile form were classified as resistant to all antifungal agents tested. Data suggest that M. pachydermatis biofilm formation is associated with antifungal resistance, paving the way towards investigating drug resistance mechanisms in Malassezia spp. PMID:23834283

  6. Antifungal Susceptibility Testing with Etest for Candida Species Isolated from Patients with Oral Candidiasis

    PubMed Central

    Song, You Bum; Ha, Gyoung Yim; Kim, Heesoo

    2015-01-01

    Background The necessity of performing antifungal susceptibility tests is recently increasing because of frequent cases of oral candidiasis caused by antifungal-resistant Candida species. The Etest (BioMerieux, Marcy l'Etoile, France) is a rapid and easy-to-perform in vitro antifungal susceptibility test. Objective The purpose of this study was to determine the minimal inhibitory concentrations (MICs) of antifungal agents by using the Etest for Candida species isolated from patients with oral candidiasis. Methods Forty-seven clinical isolates of Candida species (39 isolates of Candida albicans, 5 isolates of C. glabrata, and 3 isolates of C. tropicalis) were tested along with a reference strain (C. albicans ATCC 90028). The MIC end points of the Etest for fluconazole, itraconazole, voriconazole, and amphotericin B susceptibility were read after the 24-hour incubation of each isolate on RPMI 1640 agar. Results All Candida isolates were found susceptible to voriconazole and amphotericin B. However, all five isolates of C. glabrata were resistant to itraconazole, among which two isolates were also resistant to fluconazole. Conclusion This study revealed that the Etest represented a simple and efficacious method for antifungal susceptibility testing of Candida species isolated from oral candidiasis patients. Therefore, voriconazole and amphotericin B should be recommended as effective alternatives for the treatment of oral candidiasis. PMID:26719641

  7. Antifungal susceptibility profile of cryptic species of Aspergillus.

    PubMed

    Alastruey-Izquierdo, Ana; Alcazar-Fuoli, Laura; Cuenca-Estrella, Manuel

    2014-12-01

    The use of molecular tools has led to the description of new cryptic species among different Aspergillus species complexes. Their frequency in the clinical setting has been reported to be between 10 and 15%. The susceptibility to azoles and amphotericin B of many of these species is low, and some of them, such as Aspergillus calidoustus or Aspergillus lentulus, are considered multi-resistant. The changing epidemiology, the frequency of cryptic species, and the different susceptibility profiles make antifungal susceptibility testing an important tool to identify the optimal antifungal agent to treat the infections caused by these species.

  8. 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.

  9. Blood agar validation for susceptibility testing of isoniazid, rifampicin, ethambutol, and streptomycin to Mycobacterium tuberculosis isolates.

    PubMed

    Coban, Ahmet Yilmaz

    2013-01-01

    In recent studies, it was shown that blood agar can be used at least as effectively as Löwenstein-Jensen medium for growing Mycobacterium tuberculosis. It was also shown that susceptibility testing can be performed on blood agar. Additional validation of blood agar was performed on regional M. tuberculosis isolates from Turkey to determine critical concentrations of isoniazid (INH), rifampicin (RIF), ethambutol (ETM), and streptomycin (STR). In the current study, 40 M. tuberculosis clinical isolates were tested. H37Rv, which is susceptible to all antituberculosis agents, ATCC 35822 (INH-resistant), ATCC 35838 (RIF-resistant), ATCC 35837 (ETM-resistant), and ATCC 35820 (STR-resistant) quality control strains were used as control strains. Proportion method on 7H11 agar was considered as gold standard in the study. MIC values of the control strains and clinical isolates were detected on blood and 7H11 agar. Categorical agreements were 100% for each antibiotic, and essential agreements were 100%, 97.5%, 82.5%, and 95% for INH, RIF, ETM, and STR, respectively. According to the data, 0.2 µg/mL for INH, 1 µg/mL for RIF, 4 µg/mL for ETM, and 2 µg/mL for STR were appropriate breakpoint values for susceptibility testing on blood agar. Blood agar may be recommended for use in both developed and developing countries for the susceptibility testing of M. tuberculosis isolates to primary antituberculosis drugs.

  10. Isolation, Identification, and In Vitro Antifungal Susceptibility Testing of Dermatophytes from Clinical Samples at Sohag University Hospital in Egypt

    PubMed Central

    Shalaby, Mona Fattouh Mohamed; El-din, Asmaa Nasr; El-Hamd, Mohammed Abu

    2016-01-01

    Aim The objective of this study was to isolate, identify, and explore the in-vitro antifungal susceptibility pattern of dermatophytes isolated from clinically suspected cases of dermatophytosis (tinea infections) attending the Dermatology Outpatient Clinic. Methods This study was conducted at Sohag University Hospital from December 2014 to December 2015. Clinical samples (e.g., skin scrapings and hair stumps) were collected under aseptic precautions. The identification of dermatophytes was performed through microscopic examination using 10% potassium hydroxide (KOH) with 40% dimethyl sulphoxide (DMSO) mounts and culture on Sabouraud dextrose agar (SDA) and on Dermasel agar base media, both supplemented with chloramphenicol and cycloheximide. All dermatophytes isolates were subjected to antifungal susceptibility testing using the agar-based disk diffusion (ABDD) method against Clotrimazole, Miconazole, Fluconazole, and Griseofulvin. Data were analyzed via SPSS 16, using Chi square and a screening test (cross-tabulation method). Results A total of 110 patients of dermatophytosis were studied. The patients were clinically diagnosed and mycologically confirmed as having tinea capitis (49), tinea corporis (30), tinea pedis (16), tinea cruris (9), or tinea barbae (6). The dermatophytes isolates belonged to 4 species: Microsporum canis 58 (52.7%), Microsporum gypseum 23 (20.9%), Trichophyton mentagrophytes 18 (16.4%), and Microsporum audouinii 11 (10%). The most effective antifungal drugs tested were Clotrimazole, followed by Miconazole (95.5% and 84.5% of isolates were susceptible, respectively). Conclusion Every patient with a tinea infection should be properly studied for a mycological examination and should be treated accordingly. Dermasel agar is more useful as an identification medium in the isolation of dermatophytes. The ABDD method appears to be a simple, cost-effective, and promising method for the evaluation of antifungal susceptibility of dermatophytes. PMID

  11. Ceftibuten-containing agar plate for detecting group B streptococci with reduced penicillin susceptibility (PRGBS).

    PubMed

    Kamiya, Chitose; Kimura, Kouji; Doyama, Yo; Miyazaki, Akira; Morimoto, Makiko; Banno, Hirotsugu; Nagano, Noriyuki; Jin, Wanchun; Wachino, Jun-ichi; Yamada, Keiko; Arakawa, Yoshichika

    2015-08-01

    Penicillins remain first-line agents for treatment of group B Streptococcus (Streptococcus agalactiae; GBS) infections; however, several reports have confirmed the existence of GBS with reduced penicillin susceptibility (PRGBS). Because no selective agar plates for detection of PRGBS are available to date, in this investigation, we developed the selective agar plate for detection of PRGBS. We used 19 genetically well-confirmed PRGBS isolates and 38 penicillin-susceptible GBS isolates identified in Japan. For preparation of trial PRGBS-selective agar plates, we added 1 of antimicrobial agents (among oxacillin, ceftizoxime, and ceftibuten) to a well-established GBS-selective agar plate. Among 12 trial PRGBS-selective agar plates, Muller-Hinton agar containing 128 μg/mL ceftibuten with 5% sheep blood, 8 μg/mL gentamicin, and 12 μg/mL nalidixic acid was the most appropriate selective agar for PRGBS, showing 100% sensitivity and 81.6% specificity. In cases of potential nosocomial spread of PRGBS, the selective agar plate could be useful and reliable.

  12. Susceptibilities of Mycobacterium tuberculosis to isoniazid and rifampin on blood agar.

    PubMed

    Coban, Ahmet Yilmaz; Bilgin, Kemal; Uzun, Meltem; Tasdelen Fisgin, Nuriye; Akgunes, Alper; Cihan, Cigdem Cekic; Birinci, Asuman; Durupinar, Belma

    2005-04-01

    In this study, blood agar was used instead of 7H10 agar for the susceptibility testing of 34 clinical isolates of Mycobacterium tuberculosis to isoniazid (INH) and rifampin (RIF) in accordance with the NCCLS. The BACTEC 460 TB system (Becton Dickinson, Sparks, Md.) was used as a "gold standard." Results for both media were in agreement for RIF and INH at 100 and 94.1%, respectively. For INH, the specificity, sensitivity, positive predictive value, and negative predictive value were found to be 71.4, 100, 93.1, and 100%, respectively, while these values were 100% for RIF. In addition, the results of the susceptibility test performed with blood agar were obtained on day 14 of incubation. In conclusion, results were obtained much earlier with blood agar (2 weeks) than with 7H10 agar (3 weeks), and the results of this study suggest that blood agar may be used as an alternative medium for the susceptibility testing of M. tuberculosis to INH and RIF.

  13. Sporothrix schenckii complex in Iran: Molecular identification and antifungal susceptibility.

    PubMed

    Mahmoudi, Shahram; Zaini, Farideh; Kordbacheh, Parivash; Safara, Mahin; Heidari, Mansour

    2016-08-01

    Sporotrichosis is a global subcutaneous fungal infection caused by the Sporothrix schenckii complex. Sporotrichosis is an uncommon infection in Iran, and there have been no phenotypic, molecular typing or antifungal susceptibility studies of Sporothrix species. This study aimed to identify nine Iranian isolates of the S. schenckii complex to the species level using colony morphology, carbohydrate assimilation tests, and PCR-sequencing of the calmodulin gene. The antifungal susceptibilities of these Sporothrix isolates to five antifungal agents (amphotericin B (AMB), voriconazole (VRC), itraconazole (ITC), fluconazole (FLC), and terbinafine (TRB)) were also evaluated according to the M27-A3 and M38-A2 protocols of the Clinical and Laboratory Standards Institute for yeast and mycelial phases, respectively. Five of seven clinical isolates were identified as S. schenckii, and two clinical and two environmental isolates were identified as S. globosa. This is the first report of S. globosa in Iran. There was significant agreement (73%) between the results of the phenotypic and genotypic identification methods. TRB and ITC were the most effective antifungals against the Sporothrix isolates. The minimum inhibitory concentration (MIC) values of TRB for the yeast and mycelial phases of S. schenckii differed significantly. There was also a significant difference in the minimum fungicidal concentration (MFC) values of AMB and TRB for the two phases. Considering the low efficacy of VRC and FLC and the wide MIC ranges of AMB (1-16 μg/ml and 1-8 μg/ml for yeast and mycelial forms, respectively) observed in the present study, in vitro antifungal susceptibility testing should be performed to determine appropriate therapeutic regimens.

  14. Spectrum and the In Vitro Antifungal Susceptibility Pattern of Yeast Isolates in Ethiopian HIV Patients with Oropharyngeal Candidiasis

    PubMed Central

    Moges, Birhan; Bitew, Adane; Shewaamare, Aster

    2016-01-01

    Background. In Ethiopia, little is known regarding the distribution and the in vitro antifungal susceptibility profile of yeasts. Objective. This study was undertaken to determine the spectrum and the in vitro antifungal susceptibility pattern of yeasts isolated from HIV infected patients with OPC. Method. Oral pharyngeal swabs taken from oral lesions of study subjects were inoculated onto Sabouraud Dextrose Agar. Yeasts were identified by employing conventional test procedures and the susceptibility of yeasts to antifungal agents was evaluated by disk diffusion assay method. Result. One hundred and fifty-five yeast isolates were recovered of which 91 isolates were from patients that were not under HAART and 64 were from patients that were under HAART. C. albicans was the most frequently isolated species followed by C. glabrata, C. tropicalis, C. krusei, C. kefyr, Cryptococcus laurentii, and Rhodotorula species. Irrespective of yeasts isolated and identified, 5.8%, 5.8%, 12.3%, 8.4%, 0.6%, and 1.3% of the isolates were resistant to amphotericin B, clotrimazole, fluconazole, ketoconazole, miconazole, and nystatin, respectively. Conclusion. Yeast colonization rate of 69.2% and 31% resistance to six antifungal agents was documented. These highlight the need for nationwide study on the epidemiology of OPC and resistance to antifungal drugs. PMID:26880925

  15. Phylogenetic Relationships Matter: Antifungal Susceptibility among Clinically Relevant Yeasts

    PubMed Central

    Schmalreck, A. F.; Becker, K.; Fegeler, W.; Czaika, V.; Ulmer, H.; Lass-Flörl, C.

    2014-01-01

    The objective of this study was 2-fold: to evaluate whether phylogenetically closely related yeasts share common antifungal susceptibility profiles (ASPs) and whether these ASPs can be predicted from phylogeny. To address this question, 9,627 yeast strains were collected and tested for their antifungal susceptibility. Isolates were reidentified by considering recent changes in taxonomy and nomenclature. A phylogenetic (PHYLO) code based on the results of multilocus sequence analyses (large-subunit rRNA, small-subunit rRNA, translation elongation factor 1α, RNA polymerase II subunits 1 and 2) and the classification of the cellular neutral sugar composition of coenzyme Q and 18S ribosomal DNA was created to group related yeasts into PHYLO groups. The ASPs were determined for fluconazole, itraconazole, and voriconazole in each PHYLO group. The majority (95%) of the yeast strains were Ascomycetes. After reclassification, a total of 23 genera and 54 species were identified, resulting in an increase of 64% of genera and a decrease of 5% of species compared with the initial identification. These taxa were assigned to 17 distinct PHYLO groups (Ascomycota, n = 13; Basidiomycota, n = 4). ASPs for azoles were similar among members of the same PHYLO group and different between the various PHYLO groups. Yeast phylogeny may be an additional tool to significantly enhance the assessment of MIC values and to predict antifungal susceptibility, thereby more rapidly initiating appropriate patient management. PMID:24366735

  16. Species Distribution and In Vitro Antifungal Susceptibility of Vulvovaginal Candida Isolates in China

    PubMed Central

    Wang, Feng-Juan; Zhang, Dai; Liu, Zhao-Hui; Wu, Wen-Xiang; Bai, Hui-Hui; Dong, Han-Yu

    2016-01-01

    Background: Vulvovaginal candidiasis (VVC) was a common infection associated with lifelong harassment of woman's social and sexual life. The purpose of this study was to describe the species distribution and in vitro antifungal susceptibility of Candida species (Candida spp.) isolated from patients with VVC over 8 years. Methods: Species which isolated from patients with VVC in Peking University First Hospital were identified using chromogenic culture media. Susceptibility to common antifungal agents was determined using agar diffusion method based on CLSI M44-A2 document. SPSS software (version 14.0, Inc., Chicago, IL, USA) was used for statistical analysis, involving statistical description and Chi-square test. Results: The most common strains were Candida (C.) albicans, 80.5% (n = 1775) followed by C. glabrata, 18.1% (n = 400). Nystatin exhibited excellent activity against all species (<4% resistant [R]). Resistance to azole drugs varied among different species. C. albicans: clotrimazole (3.1% R) < fluconazole (16.6% R) < itraconazole (51.5% R) < miconazole (54.0% R); C. glabrata: miconazole (25.6% R) < clotrimazole (50.5% R) < itraconazole (61.9% R) < fluconazole (73.3% R); Candida krusei: clotrimazole (0 R) < fluconazole (57.7% R) < miconazole (73.1% R) < itraconazole (83.3% R). The susceptibility of fluconazole was noticeably decreasing among all species in the study period. Conclusions: Nystatin was the optimal choice for the treatment of VVC at present. The species distribution and in vitro antifungal susceptibility of Candida spp. isolated from patients with VVC had changed over time. PMID:27174323

  17. Diversity and antifungal susceptibility of Norwegian Candida glabrata clinical isolates

    PubMed Central

    Andersen, Kari-Mette; Kristoffersen, Anne Karin; Ingebretsen, André; Vikholt, Katharina Johnsen; Örtengren, Ulf Thore; Olsen, Ingar; Enersen, Morten; Gaustad, Peter

    2016-01-01

    Background Increasing numbers of immunocompromised patients have resulted in greater incidence of invasive fungal infections with high mortality. Candida albicans infections dominate, but during the last decade, Candida glabrata has become the second highest cause of candidemia in the United States and Northern Europe. Reliable and early diagnosis, together with appropriate choice of antifungal treatment, is needed to combat these challenging infections. Objectives To confirm the identity of 183 Candida glabrata isolates from different human body sites using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and VITEK®2, and to analyze isolate protein profiles and antifungal susceptibility. The minimum inhibitory concentration (MIC) of seven antifungal drugs was determined for the isolates to elucidate susceptibility. Design A total of 183 C. glabrata isolates obtained between 2002 and 2012 from Norwegian health-care units were analyzed. For species verification and differentiation, biochemical characterization (VITEK®2) and mass spectrometry (MALDI–TOF) were used. MIC determination for seven antifungal drugs was undertaken using E-tests®. Results Using VITEK®2, 92.9% of isolates were identified as C. glabrata, while all isolates (100%) were identified as C. glabrata using MALDI-TOF. Variation in protein spectra occurred for all identified C. glabrata isolates. The majority of isolates had low MICs to amphotericin B (≤1 mg/L for 99.5%) and anidulafungin (≤0.06 mg/L for 98.9%). For fluconazole, 18% of isolates had MICs >32 mg/L and 82% had MICs in the range ≥0.016 mg/L to ≤32 mg/L. Conclusions Protein profiles and antifungal susceptibility characteristics of the C. glabrata isolates were diverse. Clustering of protein profiles indicated that many azole resistant isolates were closely related. In most cases, isolates had highest susceptibility to amphotericin B and anidulafungin. The results confirmed previous observations of high

  18. Assessment of Etest as an alternative to agar dilution for antimicrobial susceptibility testing of Neisseria gonorrhoeae.

    PubMed

    Liu, Hsi; Taylor, Thomas H; Pettus, Kevin; Trees, David

    2014-05-01

    We studied whether the Etest can be used as an alternative to agar dilution to determine antimicrobial susceptibilities of ceftriaxone, cefixime, and cefpodoxime in Neisseria gonorrhoeae surveillance. One hundred fifteen clinical and laboratory isolates of N. gonorrhoeae were tested following the Clinical Laboratory Improvement Amendments (CLIA)-approved CLSI standard agar dilution method and, separately, by the Etest according to the manufacturer's recommendations. The MICs were determined and compared. Ten laboratory-generated mutants were used to simulate substantially nonsusceptible specimens. The Etest and agar dilution methods were well correlated. Statistical tests produced regression R2 values of 88%, 82%, and 85% and Pearson correlation coefficients of 92%, 91%, and 92% for ceftriaxone, cefixime, and cefpodoxime, respectively. When paired comparisons were made, the two tests were 88.7%, 80%, and 87% within 1 log2 dilution from each other for ceftriaxone, cefixime, and cefpodoxime, respectively. The within-2-log2 agreements were 99.1%, 98.3%, and 94.8% for ceftriaxone, cefixime, and cefpodoxime, respectively. Notwithstanding the good correlations and the within-2-log2 general agreement, the Etest results produced slightly lower MICs than the agar dilution results. In conclusion, we found that the Etest can be effectively used as an alternative to agar dilution testing to determine the susceptibility of N. gonorrhoeae to ceftriaxone, cefixime, and cefpodoxime, although we recommend further research into extremely resistant isolates. For isolates within the typical range of clinical MICs, reexamination of the Etest interpretation of susceptible and nonsusceptible categories would likely allow for successful transition from agar dilution to the Etest.

  19. Distribution and antifungal susceptibility of Candida species causing nosocomial candiduria.

    PubMed

    Ozhak-Baysan, Betil; Ogunc, Dilara; Colak, Dilek; Ongut, Gozde; Donmez, Levent; Vural, Tumer; Gunseren, Filiz

    2012-07-01

    The aim of the study was to investigate the distribution of Candida species isolated from urine specimens of hospitalized patients in Akdeniz University Hospital, Antalya, Turkey, as well as their susceptibilities to antifungal agents. A total of 100 patients who had nosocomial candiduria between March 2003 and May 2004 at the facility were included in the study. Organisms were identified by conventional methods and the use of API ID 32C strips. Susceptibilities of the isolates to amphotericin B were determined by Etest, whereas the minimum inhibitory concentration (MIC) values of these same strains to fluconazole, voriconazole and caspofungin were assessed using the broth microdilution method. The most common species recovered was C. albicans 44% of all yeasts, followed by C. tropicalis (20%), C. glabrata (18%), C. krusei (6%), C. famata (5%), C. parapsilosis (4%), C. kefyr (2%) and C. guilliermondii (1%). A total of nine (9%) of the isolates, including five C. krusei and four C. glabrata isolates were susceptible dose-dependent (SDD) to fluconazole. In constrast, only two C. glabrata and one C. krusei isolates were resistant to this antifungal. The voriconazole MICs for all Candida isolates were ≤0.5 μg/ml, except for one C. glabrata isolate with a MIC value of 2 μg/ml. Among all isolates, 94% were susceptible to amphotericin B with MIC values of <1 μg/ml and all isolates were susceptible to caspofungin with MIC values of ≤0.5 μg/ml. Future studies are needed to define better treatment regimens for those patients who have fluconazole-resistant Candida urinary tract infections.

  20. Microcolonies in fluoroquinolone agar proportion susceptibility testing of Mycobacterium tuberculosis: an indicator of drug resistance

    PubMed Central

    Blackman, A.; May, S.; Devasia, R. A.; Maruri, F.; Stratton, C.

    2014-01-01

    Microcolony growth of Mycobacterium tuberculosis on agar proportion susceptibility testing is neither well-defined nor previously reported with fluoroquinolone susceptibility testing. We describe here M. tuberculosis microcolony growth with fluoroquinolones, and assess its clinical significance. We screened 797M. tuberculosis isolates for ofloxacin resistance (2.0 µg/mL) by agar proportion; 19 ofloxacin-resistant and 38 ofloxacin-susceptible isolates were selected for more detailed susceptibility testing with ofloxacin, ciprofloxacin, levofloxacin (all at 2.0 µg/mL) and moxifloxacin (0.5 µg/mL). The 57 isolates were also tested at two concentrations both above and below the critical concentrations. Microcolonies were defined as colonies 0.2–0.4 mm in diameter; confirmed microcolonies were present on repeat testing. Of the 57 isolates tested in detail, 7 grew microcolonies, of which 2 (0.3% of all isolates tested) had confirmed microcolonies on repeat testing (6 tests performed, and microcolonies were present on at least 4). Both M. tuberculosis isolates were ofloxacin-resistant on screening, and had ofloxacin minimum inhibitory concentration (MIC) >8 µg/mL. The five other isolates were ofloxacin-susceptible on screening, but had regular colony growth (i.e., resistance) at the drug concentration that initially resulted in microcolonies (ofloxacin 0.5 or 1.0 µg/mL). Microcolonies were observed infrequently with fluoroquinolone susceptibility testing, but when confirmed, they were associated with drug resistance. PMID:22322359

  1. 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

  2. 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.

  3. Rapid Isolation and Susceptibility Testing of Leptospira spp. Using a New Solid Medium, LVW Agar

    PubMed Central

    Wuthiekanun, Vanaporn; Amornchai, Premjit; Paris, Daniel H.; Langla, Sayan; Thaipadunpanit, Janjira; Chierakul, Wirongrong; Smythe, Lee D.; White, Nicholas J.; Day, Nicholas P. J.; Peacock, Sharon J.

    2013-01-01

    Pathogenic Leptospira spp., the causative agents of leptospirosis, are slow-growing Gram-negative spirochetes. Isolation of Leptospira from clinical samples and testing of antimicrobial susceptibility are difficult and time-consuming. Here, we describe the development of a new solid medium that facilitates more-rapid growth of Leptospira spp. and the use of this medium to evaluate the Etest's performance in determining antimicrobial MICs to drugs in common use for leptospirosis. The medium was developed by evaluating the effects of numerous factors on the growth rate of Leptospira interrogans strain NR-20157. These included the type of base agar, the concentration of rabbit serum (RS), and the concentration and duration of CO2 incubation during the initial period of culture. The highest growth rate of NR-20157 was achieved using a Noble agar base supplemented with 10% RS (named LVW agar), with an initial incubation at 30°C in 5% CO2 for 2 days prior to continuous culture in air at 30°C. These conditions were used to develop the Etest for three species, L. interrogans (NR-20161), L. kirschnerii (NR-20327), and L. borgpetersenii (NR-20151). The MICs were read on day 7 for all samples. The Etest was then performed on 109 isolates of pathogenic Leptospira spp. The MIC90 values for penicillin G, doxycycline, cefotaxime, ceftriaxone, and chloramphenicol were 0.64 units/ml and 0.19, 0.047, 0.5, and 2 μg/ml, respectively. The use of LVW agar, which enables rapid growth, isolation of single colonies, and simple antimicrobial susceptibility testing for Leptospira spp., provides an opportunity for new areas of fundamental and applied research. PMID:23114772

  4. [In vitro antifungal susceptibility, in vivo antifungal activity and security from a natural product obtained from sunrise oil (AMO3) against dermatophytes].

    PubMed

    Thomson M, Pamela; Anticevic C, Sonia; Rodríguez B, Héctor; Silva V, Víctor

    2011-12-01

    This work studied safety and antifungal activity of ozonized sunflower oil (AMO3) against dermatophytes. AMO3 was prepared through a new original process that modifies the oil before ozonation by alcoholic catalytic esterification. Susceptibility was studied in 41 dermatophytes by agar diffusion and broth microdilution tests. The experimental model to assess the topical safety of the oil included 60 CF1 mice divided in three groups that were treated with vaseline (control), 1% AMO3 and 50% AMO3 (overdose), respectively. Then, experimental dermatophytosis was induced in CF1 mice. Seventy-five individuals were selected and divided in 5 groups that were treated once a day with placebo, cream with 1%, 2% and 3% AMO3 plus an untreated control group. This new natural product showed antifungal activity against all strains studied. The MIC ranged between was 0,125 and 1%, while minimum fungicidal concentration (MFC) was 2%. The application of vaseline and AMO3 1% and 50% did not produce clinical or histopathological lesions. The mice with dermatophytosis that were treated with 1%, 2% and 3% AMO3 showed 100% clinical cure and 94% average mycological cure, exceeding placebo and control groups (p < 0,05). This product exhibits high antifungal activity and could be a safe alternative for ringworm topical treatment. PMID:22286673

  5. Tetrazolium reduction as an aid for streptococcal growth detection with agar dilution susceptibility testing.

    PubMed Central

    Coudron, P E; Ford, J M; Dalton, H P

    1983-01-01

    A dye reduction method for determining a definitive endpoint with agar dilution susceptibility testing has been developed. Bacterial growth was determined by applying to the inoculum spot a dye solution containing 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride and phenazine methosulfate. Viable colonies reduced the tetrazolium salt to a visible red color within 3 to 5 min. The minimum inhibitory concentrations of six antimicrobial agents tested against 167 clinical streptococcal isolates were recorded before and after the addition of the tetrazolium-phenazine methosulfate solution. A total of 252 discrepancies (25%) were observed, and of these, 30 (12%) differed by more than one tested antibiotic concentration. Endpoint reproducibility of the dye procedure was assessed by four technologists in a double-blind study. A 2.7-fold reduction in disagreement was observed when the dye was used. Use of the tetrazolium-phenazine methosulfate solution involves little deviation from standard antimicrobial susceptibility test procedures and yields more accurate, as well as reproducible, susceptibility results. PMID:6630459

  6. 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.

  7. In vitro antifungal susceptibility of Malassezia pachydermatis from dogs with and without skin lesions.

    PubMed

    Cafarchia, Claudia; Figueredo, Luciana A; Iatta, Roberta; Montagna, Maria Teresa; Otranto, Domenico

    2012-03-23

    Canine Malassezia dermatitis is frequently treated with systemic ketoconazole (KTZ) and itraconazole (ITZ). However, no information is available on the antifungal susceptibility to azoles and allilamine of Malassezia pachydermatis isolates from dogs with or without skin lesions. The present study was designed to evaluate the in vitro antifungal susceptibility of M. pachydermatis strains from dogs with or without skin lesions to KTZ, ITZ, miconazole (MICO), fluconazole (FLZ), posaconazole (POS), voriconazole (VOR) and terbinafine (TER) using the Clinical and Laboratory Standards Institute reference Broth Microdilution Method (CLSI M27-A2). The association between the susceptibility to antifungal compounds and the origin of M. pachydermatis, from skin with or without lesions has been also assessed. A total of 62 M. pachydermatis strains from healthy dogs (i.e., Group A=30) or with skin lesions (i.e., Group B=32) were tested. ITZ, KTZ and POS showed the highest activity against M. pachydermatis strains, whereas MICO TER and FLZ the lowest. A higher number of Malassezia resistant strains were registered among isolates from Group B than those from Group A. This study indicates that M. pachydermatis strains were susceptible to ITZ, KTZ, and POS. However, dogs with lesions may harbour strains with low susceptibility to antifungal agents and displaying cross-resistance phenomena to azole. The antifungal therapy in Malassezia infections requires careful appraisal of choice of drugs especially in cases of unresponsiveness to antifungal treatment or recurrent infections. PMID:21962411

  8. In Vitro Antifungal Susceptibilities of Five Species of Sporothrix▿

    PubMed Central

    Marimon, Rita; Serena, Carolina; Gené, Josepa; Cano, Josep; Guarro, Josep

    2008-01-01

    Ninety-two isolates belonging to five species of the Sporothrix schenckii complex were tested in vitro against 12 antifungal agents, using a reference microdilution method. There were significant differences among the species; Sporothrix brasiliensis was the species that showed the best response to antifungals, and S. mexicana had the worst response. In general, terbinafine was the most active drug, followed by ketoconazole and posaconazole. PMID:18039919

  9. Rapid Direct Testing of Susceptibility of Mycobacterium tuberculosis to Isoniazid and Rifampin on Nutrient and Blood Agar in Resource-Starved Settings

    PubMed Central

    Ikram, Aamer; Coban, Ahmet Yilmaz; Martin, Anandi

    2012-01-01

    In this study, we evaluated the performance of blood agar (by macroscopic growth) and nutrient agar (by a microcolony detection method) for drug susceptibility testing of Mycobacterium tuberculosis against rifampin (RIF) and isoniazid (INH), using 67 smear-positive sputum specimens. The direct proportion method on Lowenstein-Jensen (LJ) medium was used as the “gold standard.” Compared with LJ medium, results for both media were in 100% agreement for RIF, while for INH the agreement levels for blood agar and nutrient agar were 98% and 95%, respectively. Within 2 weeks, 100% of specimens yielded results on blood agar, while 96.8% of specimens yielded results on nutrient agar. Our study showed that blood agar and nutrient agar can be used as alternative media for direct susceptibility testing of RIF and INH, especially in resource-poor settings. PMID:22357498

  10. Rapid direct testing of susceptibility of Mycobacterium tuberculosis to isoniazid and rifampin on nutrient and blood agar in resource-starved settings.

    PubMed

    Satti, Luqman; Ikram, Aamer; Coban, Ahmet Yilmaz; Martin, Anandi

    2012-05-01

    In this study, we evaluated the performance of blood agar (by macroscopic growth) and nutrient agar (by a microcolony detection method) for drug susceptibility testing of Mycobacterium tuberculosis against rifampin (RIF) and isoniazid (INH), using 67 smear-positive sputum specimens. The direct proportion method on Lowenstein-Jensen (LJ) medium was used as the "gold standard." Compared with LJ medium, results for both media were in 100% agreement for RIF, while for INH the agreement levels for blood agar and nutrient agar were 98% and 95%, respectively. Within 2 weeks, 100% of specimens yielded results on blood agar, while 96.8% of specimens yielded results on nutrient agar. Our study showed that blood agar and nutrient agar can be used as alternative media for direct susceptibility testing of RIF and INH, especially in resource-poor settings.

  11. Quantitative Microplate-Based Growth Assay for Determination of Antifungal Susceptibility of Histoplasma capsulatum Yeasts

    PubMed Central

    Goughenour, Kristie D.; Balada-Llasat, Joan-Miquel

    2015-01-01

    Standardized methodologies for determining the antifungal susceptibility of fungal pathogens is central to the clinical management of invasive fungal disease. Yeast-form fungi can be tested using broth macrodilution and microdilution assays. Reference procedures exist for Candida species and Cryptococcus yeasts; however, no standardized methods have been developed for testing the antifungal susceptibility of yeast forms of the dimorphic systemic fungal pathogens. For the dimorphic fungal pathogen Histoplasma capsulatum, susceptibility to echinocandins differs for the yeast and the filamentous forms, which highlights the need to employ Histoplasma yeasts, not hyphae, in antifungal susceptibility tests. To address this, we developed and optimized methodology for the 96-well microtiter plate-based measurement of Histoplasma yeast growth in vitro. Using optical density, the assay is quantitative for fungal growth with a dynamic range greater than 30-fold. Concentration and assay reaction time parameters were also optimized for colorimetric (MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] reduction) and fluorescent (resazurin reduction) indicators of fungal vitality. We employed this microtiter-based assay to determine the antifungal susceptibility patterns of multiple clinical isolates of Histoplasma representing different phylogenetic groups. This methodology fulfills a critical need for the ability to monitor the effectiveness of antifungals on Histoplasma yeasts, the morphological form present in mammalian hosts and, thus, the form most relevant to disease. PMID:26246483

  12. Update from the Laboratory: Clinical Identification and Susceptibility Testing of Fungi and Trends in Antifungal Resistance.

    PubMed

    Albataineh, Mohammad T; Sutton, Deanna A; Fothergill, Annette W; Wiederhold, Nathan P

    2016-03-01

    Despite the availability of new diagnostic assays and broad-spectrum antifungal agents, invasive fungal infections remain a significant challenge to clinicians and are associated with marked morbidity and mortality. In addition, the number of etiologic agents of invasive mycoses has increased accompanied by an expansion in the immunocompromised patient populations, and the use of molecular tools for fungal identification and characterization has resulted in the discovery of several cryptic species. This article reviews various methods used to identify fungi and perform antifungal susceptibility testing in the clinical laboratory. Recent developments in antifungal resistance are also discussed. PMID:26739605

  13. Evaluation of agar-based medium with sheep sera for testing of drug susceptibility of Mycobacterium tuberculosis to Isoniazid, Rifampin, Ethambutol, and Streptomycin.

    PubMed

    Coban, Ahmet Yilmaz; Uzun, Meltem; Bozdogan, Bulent

    2013-12-01

    The performance of sheep sera instead of sheep blood in agar-based media was investigated for susceptibility testing of Mycobacterium tuberculosis against primary drugs. The levels of agreement between agar-based medium supplemented with sheep sera and the proportion method on Middlebrook 7H11 agar as the reference method for determining susceptibility to isoniazid (INH), rifampin (RIF), ethambutol (EMB), and streptomycin (STR) were 98.4, 98.4, 95.3, and 100%, respectively.

  14. Virulence factors and antifungal susceptibility of Candida albicans isolates from oral candidosis patients and control individuals.

    PubMed

    Koga-Ito, Cristiane Yumi; Lyon, Juliana Pereira; Vidotto, Valerio; de Resende, Maria Aparecida

    2006-04-01

    Sixty isolates of Candida albicans, 30 obtained from the oral cavity of denture wearers presenting signs of candidosis and 30 obtained from the oral cavity of denture wearers with normal palatal mucosa were assayed for phospholipase and proteinase production, as well as for adherence to buccal epithelial cells. Likewise, susceptibility of the isolates to antifungals was determined by the NCCLS reference method and the E-test method. Proteinase activity was increased among the strains obtained from oral candidosis patients. In contrast, no significant differences between the two groups of isolates were observed in their adherence ability in vitro, in phospholipase production, and susceptibility to antifungal drugs.

  15. Comparison of E-test with agar dilution methods in testing susceptibility of N. gonorrhoeae to azithromycin.

    PubMed

    Yasin, R M; Suan, K A; Meng, C Y

    1997-05-01

    A single dose of a new antibiotic, azithromycin, has been shown to be effective in the treatment of uncomplicated Neisseria gonorrhoeae. A clinical study was conducted to assess the in vitro susceptibility of N gonorrhoeae to azithromycin and compare the reliability of results obtained using the new E-test methodology for determination of the minimum inhibitory concentration (MIC) of antibiotic with those obtained through the standard agar dilution method. 135 clinical isolates of N gonorrhoeae were obtained from patients attending hospital-based sexually transmitted disease clinics in five geographic locations in Malaysia. 76 of the isolates were penicillinase-producing N gonorrhoeae and 69 were high-level tetracycline-resistant N gonorrhoeae. All isolates were susceptible to azithromycin based on the susceptible MIC breakpoint of 2.0 mcg/ml. The MICs ranged from 0.0078-0.25 mcg/ml by agar dilution method and from 0.016-0.50 mcg/ml by E-test. Agreement between these two methods was 97.8%. The single-dose regime and good antigonococcal and antichlamydial activity of azithromycin make this antibiotic a suitable treatment choice. Moreover, the findings of this study suggest that the simpler, faster E-test is as reliable as the agar dilution method. Given the tendency of the antimicrobial susceptibility pattern of N gonorrhoeae to change rapidly, it is important to monitor MICs to detect the emergence of resistance.

  16. Susceptibility of a polycaprolactone-based root canal filling material to degradation using an agar-well diffusion assay

    PubMed Central

    Hiraishi, Noriko; Sadek, Fernanda T.; King, Nigel M.; Ferrari, Marco; Pashley, David H.; Tay, Franklin R

    2013-01-01

    Purpose Cholesterol esterase is both a component of salivary hydrolases as well as an inflammatory cell-derived enzyme and has been shown to cause biodegradation of methacrylate-based resin composites. This study examined whether Resilon, a polycaprolactone-based thermoplastic root filling material is susceptible to biodegradation by cholesterol esterase using agar-well diffusion assay of serially-diluted aqueous Resilon emulsions that were dispersed in agar. Materials and methods Emulsions of Resilon and polycaprolactone were prepared and dispersed in agar on culture plates. Two different concentrations of a cholesterol esterase (0.3 and 1.2 U/mL) were prepared and fed to wells prepared in the agar plates using an agar-well diffusion assay for examination the degradation of polymeric materials. Results Degradation of the emulsified Resilon was manifested as the formation of clear zones of different sizes around the agar wells. No clear zones were observed in agar wells that contain sterile distilled water as the negative control. Clinical significance Although dispersion Resilon into an emulsion is not the way in which this material is employed as a root filling material, the potential for Resilon to be degraded by cholesterol esterase is of potential concern as one cannot limit the degradation of extruded Resilon from a root apex by monocyte-derived macrophages to just the anatomical root apex. As the present study employed a high concentration of cholesterol esterase, further studies should be directed to examining the degradation of Resilon using macrophage cell cultures. PMID:18578181

  17. 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.

  18. Species distribution & antifungal susceptibility pattern of oropharyngeal Candida isolates from human immunodeficiency virus infected individuals

    PubMed Central

    Das, Partha Pratim; Saikia, Lahari; Nath, Reema; Phukan, Sanjib Kumar

    2016-01-01

    Background & objectives: The changing spectrum of Candida species in causation of oropharyngeal candidiasis and their antifungal susceptibility pattern among the HIV infected individuals has made the identification to species level mandatory and detection of drug resistance necessary for patient care. The present study was carried out to determine the species distribution and antifungal susceptibility profile of oral Candida isolates colonizing or infecting both HIV seropositive and seronegative individuals. Methods: A case-control study was conducted including 141 consecutive, non-repeat HIV-seropositive individuals and an equal number of sex and age matched HIV-seronegative control. Speciation of the oropharyngeal Candida isolates was done using standard yeast identification protocol. Antifungal susceptibility testing was done by the disk-diffusion method as well as by Fungitest method. Results: From the 59 culture positive HIV seropositive cases, 61 Candida isolates were recovered; Candida albicans (n=47, 77.0%), C. dubliniensis (n=9, 14.7%), C. parapsilosis (n=2, 3.2%), C. glabrata (n=2, 3.2%), and C. famata (n=1, 1.6%). Candida colonization in HIV-seropositive individuals was significantly higher than that of HIV-seronegative (control) group. Antifungal susceptibility testing revealed (n=6, 9.3%) C. albicans isolates resistant to voriconazole and fluconazole by disk-diffusion method whereas no resistance was seen by Fungitest method. Interpretation & conclusions: C. albicans was the commonest Candida species infecting or colonizing HIV seropositive individuals. Oropharyngeal Candida isolates had high level susceptibility to all the major antifungals commonly in use. Increased level of immunosuppression in HIV-seropositives and drug resistance of non-albicans Candida species makes identification and susceptibility testing of Candida species necessary in different geographical areas of the country. PMID:27377507

  19. Critical review on retrospective and prospective changes in antifungal susceptibility testing for dermatophytes.

    PubMed

    Thatai, Purva; Sapra, Bharti

    2016-10-01

    Antifungal susceptibility testing is a progressive field of mycology with respect to dermatophytes as well as non-dermatophytes. Documentation and approval regarding standardisation of in vitro susceptibility testing have been done by different governing bodies such as Clinical and Laboratory Standards Institute, European Committee on Antimicrobial Susceptibility Testing and British Society of Antimicrobial Chemotherapy. The process of standardisation and approval started in 1985 with certain amendments in 2002 and 2004. In case of dermatophytes, antifungal susceptibility testing protocol has been approved recently in 2008; however, the approved standardisation also needs certain amendments/modifications due to the limitations of an existing method. In the present review, we have compiled these standardisation techniques along with the limitations and advantages and the amendments that have been proposed at different time periods by different researchers and regulatory agencies. PMID:27292456

  20. Antifungal susceptibilities of non-Aspergillus filamentous fungi causing invasive infection in Australia: support for current antifungal guideline recommendations.

    PubMed

    Halliday, Catriona L; Chen, Sharon C-A; Kidd, Sarah E; van Hal, Sebastian; Chapman, Belinda; Heath, Christopher H; Lee, Andie; Kennedy, Karina J; Daveson, Kathryn; Sorrell, Tania C; Morrissey, C Orla; Marriott, Deborah J; Slavin, Monica A

    2016-10-01

    Antifungal susceptibilities of non-Aspergillus filamentous fungal pathogens cannot always be inferred from their identification. Here we determined, using the Sensititre(®) YeastOne(®) YO10 panel, the in vitro activities of nine antifungal agents against 52 clinical isolates of emergent non-Aspergillus moulds representing 17 fungal groups in Australia. Isolates comprised Mucorales (n = 14), Scedosporium/Lomentospora spp. (n = 18) and a range of hyaline hyphomycetes (n = 9) and other dematiaceous fungi (n = 11). Excluding Verruconis gallopava, echinocandins demonstrated poor activity (MICs generally >8 mg/L) against these moulds. Lomentospora prolificans (n = 4) and Fusarium spp. (n = 6) demonstrated raised MICs to all antifungal drugs tested, with the lowest being to voriconazole and amphotericin B (AmB), respectively (geometric mean MICs of 3.4 mg/L and 2.2 mg/L, respectively). All Scedosporium apiospermum complex isolates (n = 14) were inhibited by voriconazole concentrations of ≤0.25 mg/L, followed by posaconazole and itraconazole at ≤1 mg/L. Posaconazole and AmB were the most active agents against the Mucorales, with MIC90 values of 1 mg/L and 2 mg/L, respectively, for Rhizopus spp. For dematiaceous fungi, all isolates were inhibited by itraconazole and posaconazole concentrations of ≤0.5 mg/L (MIC90, 0.12 mg/L and 0.25 mg/L, respectively), but voriconazole and AmB also had in vitro activity (MIC90, 0.5 mg/L and 1 mg/L, respectively). Differences in antifungal susceptibility within species and between species within genera support the need for testing individual patient isolates to guide therapy. The Sensititre(®) YeastOne(®) offers a practical alternative to the reference methodology for susceptibility testing of moulds.

  1. Cell-on-hydrogel platform made of agar and alginate for rapid, low-cost, multidimensional test of antimicrobial susceptibility.

    PubMed

    Sun, Han; Liu, Zhengzhi; Hu, Chong; Ren, Kangning

    2016-08-01

    Antimicrobial resistance (AMR) is a rapidly increasing threat to the effective treatment of infectious diseases worldwide. The two major remedies include: (1) using narrow-spectrum antibiotics based on rapid diagnosis; and (2) developing new antibiotics. A key part of both remedies is the antimicrobial susceptibility test (AST). However, the current standard ASTs that monitor colony formation are costly and time-consuming and the new strategies proposed are not yet practical to be implemented. Herein, we report a strategy to fabricate whole-hydrogel microfluidic chips using alginate-doped agar. This agar-based microfabrication makes it possible to prepare inexpensive hydrogel devices, and allows a seamless link between microfluidics and conventional agar-based cell culture. Different from common microfluidic systems, in our system the cells are cultured on top of the device, similar to normal agar plate culture; on the other hand, the microfluidic channels inside the hydrogel allow precise generation of linear gradient of drugs, thus giving a better performance than the conventional disk diffusion method. Cells in this system are not exposed to any shear flow, which allows the reliable tracking of individual cells and AST results to be obtained within 2-3 hours. Furthermore, our system could test the synergistic effect of drugs through two-dimensional gradient generation. Finally, the platform could be directly implemented to new drug discovery and other applications wherein a fast, cost-efficient method for studying the response of microorganisms upon drug administration is desirable. PMID:27452345

  2. 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.

  3. Comparison of Citrated Human Blood, Citrated Sheep Blood, and Defibrinated Sheep Blood Mueller-Hinton Agar Preparations for Antimicrobial Susceptibility Testing of Streptococcus pneumoniae Isolates ▿

    PubMed Central

    Satzke, Catherine; Seduadua, Anna; Chandra, Reginald; Carapetis, Jonathan R.; Mulholland, E. Kim; Russell, Fiona M.

    2010-01-01

    The use of Mueller-Hinton agar supplemented with citrated human or citrated sheep blood was compared with the use of routinely used Mueller-Hinton agar supplemented with defibrinated sheep blood for antimicrobial susceptibility testing of Streptococcus pneumoniae. The alternate supplements were found to be unsatisfactory, particularly for testing resistant isolates, and therefore are not recommended. PMID:20668133

  4. Characterization of multidrug-resistant group B streptococci with reduced penicillin susceptibility forming small non-Beta-hemolytic colonies on sheep blood agar plates.

    PubMed

    Banno, Hirotsugu; Kimura, Kouji; Tanaka, Yosuke; Kitanaka, Hiromitsu; Jin, Wanchun; Wachino, Jun-ichi; Yamada, Keiko; Shibayama, Keigo; Arakawa, Yoshichika

    2014-06-01

    We isolated and characterized three multidrug-resistant clinical isolates of group B streptococci with reduced penicillin susceptibility (PRGBS) that formed small non-beta-hemolytic colonies on sheep blood agar plates but grew well on chocolate agar plates. They can be overlooked in the bacterial identification step, leading to clinical misdiagnosis and treatment failure.

  5. Comparison of citrated human blood, citrated sheep blood, and defibrinated sheep blood Mueller-Hinton agar preparations for antimicrobial susceptibility testing of Streptococcus pneumoniae isolates.

    PubMed

    Satzke, Catherine; Seduadua, Anna; Chandra, Reginald; Carapetis, Jonathan R; Mulholland, E Kim; Russell, Fiona M

    2010-10-01

    The use of Mueller-Hinton agar supplemented with citrated human or citrated sheep blood was compared with the use of routinely used Mueller-Hinton agar supplemented with defibrinated sheep blood for antimicrobial susceptibility testing of Streptococcus pneumoniae. The alternate supplements were found to be unsatisfactory, particularly for testing resistant isolates, and therefore are not recommended.

  6. ANTIFUNGAL SUSCEPTIBILITY TESTING AND GENOTYPING CHARACTERIZATION OF Cryptococcus neoformans AND gattii ISOLATES FROM HIV-INFECTED PATIENTS OF RIBEIRÃO PRETO, SÃO PAULO, BRAZIL

    PubMed Central

    FIGUEIREDO, Thais Pandini; de LUCAS, Rosymar Coutinho; CAZZANIGA, Rodrigo Anselmo; FRANÇA, Carolina Nunes; SEGATO, Fernando; TAGLIALEGNA, Rafael; MAFFEI, Claudia Maria Leite

    2016-01-01

    SUMMARY Cryptococcosis is a leading invasive fungal infection in immunocompromised patients. Considering the high prevalence and severity of these infections in immunocompromised patients attended at HC-FMRP-USP, the present research aimed to characterize the clinical isolates of Cryptococcus strains by biochemical and molecular methods and evaluate antifungal susceptibility of clinical isolates. Fifty isolates from 32 HIV-positive patients were obtained at HC-FMRP-USP. Most of the isolates (78.1%) were identified as C. neoformans, and 100% of C. neoformans and C. gattii strains were susceptible to amphotericin B, ketoconazole and fluconazole. All isolates were classified as serotype A (grubbii variety) by PCR and most of them were characterized in mating type MATa. PCR analysis of specific M13 microsatellite sequence revealed that VNI type was predominant among C. neoformans, while VGII was predominant among C. gattii. The strains did not show a significant resistance to the antifungals tested, and Canavanine-Glycine-Bromthymol Blue Agar (CGB) proved to be a reliable test presenting a good correlation with the molecular characterization. C. neoformans isolated from disseminated infections in the same patient showed molecular identity when different anatomical sites were compared; besides, the studied strains did not present a significant increase in resistance to antifungal agents. In addition, the homogeneity of the molecular types and detection of the mating types suggested a low possibility of crossing among the strains. PMID:27680174

  7. Antifungal Susceptibility and Phylogeny of Opportunistic Members of the Order Mucorales

    PubMed Central

    Vitale, Roxana G.; de Hoog, G. Sybren; Schwarz, Patrick; Dannaoui, Eric; Deng, Shuwen; Machouart, Marie; Voigt, Kerstin; van de Sande, Wendy W. J.; Dolatabadi, Somayeh; Meis, Jacques F.

    2012-01-01

    The in vitro susceptibilities of 66 molecularly identified strains of the Mucorales to eight antifungals (amphotericin B, terbinafine, itraconazole, posaconazole, voriconazole, caspofungin, micafungin, and 5-fluorocytosine) were tested. Molecular phylogeny was reconstructed based on the nuclear ribosomal large subunit to reveal taxon-specific susceptibility profiles. The impressive phylogenetic diversity of the Mucorales was reflected in susceptibilities differing at family, genus, and species levels. Amphotericin B was the most active drug, though somewhat less against Rhizopus and Cunninghamella species. Posaconazole was the second most effective antifungal agent but showed reduced activity in Mucor and Cunninghamella strains, while voriconazole lacked in vitro activity for most strains. Genera attributed to the Mucoraceae exhibited a wide range of MICs for posaconazole, itraconazole, and terbinafine and included resistant strains. Cunninghamella also comprised strains resistant to all azoles tested but was fully susceptible to terbinafine. In contrast, the Lichtheimiaceae completely lacked strains with reduced susceptibility for these antifungals. Syncephalastrum species exhibited susceptibility profiles similar to those of the Lichtheimiaceae. Mucor species were more resistant to azoles than Rhizopus species. Species-specific responses were obtained for terbinafine where only Rhizopus arrhizus and Mucor circinelloides were resistant. Complete or vast resistance was observed for 5-fluorocytosine, caspofungin, and micafungin. Intraspecific variability of in vitro susceptibility was found in all genera tested but was especially high in Mucor and Rhizopus for azoles and terbinafine. Accurate molecular identification of etiologic agents is compulsory to predict therapy outcome. For species of critical genera such as Mucor and Rhizopus, exhibiting high intraspecific variation, susceptibility testing before the onset of therapy is recommended. PMID:22075600

  8. Antifungal Susceptibility Analysis of Clinical Isolates of Candida parapsilosis in Iran

    PubMed Central

    LOTFALI, Ensieh; KORDBACHEH, Parivash; MIRHENDI, Hossein; ZAINI, Farideh; GHAJARI, Ali; MOHAMMADI, Rasoul; NOORBAKHSH, Fatemeh; MOAZENI, Maryam; FALLAHI, Aliakbar; REZAIE, Sassan

    2016-01-01

    Background: Candida parapsilosis is an emergent agent of invasive fungal infections. This yeast is one of the five most widespread yeasts concerned in invasive candidiasis. C. parapsilosis stands out as the second most common yeast species isolated from patients with bloodstream infections especially in neonates with catheter. Recently several reports suggested that its reduced susceptibility to azoles and polyene might become a cause for clinical concern, although C. parapsilosis is not believed to be intensely prone to the development of antifungal resistance. Methods: In the present report, One hundred and twenty clinical isolates of C. parapsilosis complex were identified and differentiated by using PCR-RFLP analysis. The isolates were then analyzed to determine their susceptibility profile to fluconazole (FLU), itraconazole (ITC) and amphotericin B. The minimum inhibitory concentration (MIC) results were analyzed according to the standard CLSI guide. Results: All of isolates were identified as C. parapsilosis. No C. metapsilosis and C. orthopsilosis strains were found. Evaluation of the antifungal susceptibility profile showed that only three (2.5%) C. parapsilosis were resistant to fluconazole, three (2.5%) C. parapsilosis were resistant to itraconazole and two (1.7%) C. parapsilosis were amphotericin B resistant. Conclusion: Profiles in clinical isolates of C. parapsilosis can provide important information for the control of antifungal resistance as well as distribution and susceptibility profiles in populations. PMID:27141494

  9. Microdilution in vitro Antifungal Susceptibility Patterns of Candida Species, From Mild Cutaneous to Bloodstream Infections

    PubMed Central

    Rezazadeh, Elham; Sabokbar, Azar; Moazeni, Maryam; Rezai, Mohammad Sadegh; Badali, Hamid

    2016-01-01

    Background Candida species, as opportunistic organisms, can cause various clinical manifestations, ranging from mild cutaneous infections to systemic candidiasis in otherwise healthy individuals. Remarkably, the incidence and mortality rates of candidemia have significantly increased worldwide, even after advances in medical interventions and the development of novel antifungal drugs. Objectives Given the possible resistance to antifungal agents, susceptibility testing can be useful in defining the activity spectrum of antifungals and determining the appropriate treatment regime. Materials and Methods The in vitro susceptibilities of molecularly identified Candida strains (n = 150) belonging to seven species recovered from clinical specimens, including vaginal, cutaneous, sputum, bronchoalveolar lavage (BAL), and blood samples, were determined for six antifungal drugs (amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, and caspofungin), based on the clinical and laboratory standards institute’s M27-A3 and M27-S4 documents. Results Candida albicans was the most frequently isolated species (44.66%), followed by non-albicans Candida, including C. glabrata (20%), C. parapsilosis (13.33%), C. krusei (8%), C. tropicalis (7.3%), C. dubliniensis (4%), and C. africana (3.33%). Posaconazole had the lowest geometric mean minimum inhibitory concentration (MIC) (0.0122 µg/ml), followed by amphotericin B (0.0217 µg/mL), voriconazole (0.1022 µg/mL), itraconazole (0.1612 µg/mL), caspofungin (0.2525 µg/mL), and fluconazole (0.4874 µg/mL) against all isolated Candida species. Candida africana and C. parapsilosis were significantly more susceptible to fluconazole, compared to C. albicans and other Candida species (P < 0.001). However, their clinical effectiveness in the treatment of Candida infections remains to be determined. Conclusions These findings highlight the importance of precise and correct species identification of clinical yeast isolates via

  10. Testing susceptibility of multidrug-resistant Mycobacterium tuberculosis to second-line drugs by use of blood agar.

    PubMed

    Satana, Dilek; Coban, Ahmet Yilmaz; Uzun, Meltem

    2010-11-01

    In this study, the susceptibilities of 35 multidrug-resistant (MDR) Mycobacterium tuberculosis clinical isolates to second-line drugs, including kanamycin (KM), rifabutin (RBU), ofloxacin (OFX), p-aminosalicylic acid (PAS), capreomycin (CAP), clofazimine (CFM), and ethionamide (ETH), were investigated on blood agar according to CLSI recommendations. Compared with the results of the Bactec 460 TB system, agreement was 100, 100, 97, 100, 100, 100, and 86% for KM, RBU, OFX, PAS, CAP, CFM, and ETH, respectively. Compared with the results of the proportion method, agreement was 100, 100, 97, 100, 97, 100, and 77% for KM, RBU, OFX, PAS, CAP, CFM, and ETH, respectively.

  11. Antifungal susceptibilities and identification of species of the Sporothrix schenckii complex isolated in Brazil.

    PubMed

    Ottonelli Stopiglia, Cheila Denise; Magagnin, Cibele Massotti; Castrillón, Mauricio Ramírez; Mendes, Sandra Denise Camargo; Heidrich, Daiane; Valente, Patricia; Scroferneker, Maria Lúcia

    2014-01-01

    Sporotrichosis is a subacute or chronic mycosis caused worldwide by the dimorphic species complex, Sporothrix schenckii. We studied 85 isolates recovered in Brazil to verify their identification and evaluate their in vitro antifungal susceptibility patterns. Based on phenotypic tests (microscopic features, ability to grow at 30°C and 37°C, colony diameters, as well as assimilation of sucrose and raffinose) and molecular assays (amplification of a fragment of the calmodulin gene), the strains were identified as S. schenckii, S. brasiliensis and S. globosa, with a predominance of S. schenckii isolates. There was 37.7% disagreement between the phenotypic and genotypic identification methodologies. In general, terbinafine was the most active drug, followed by ketoconazole and itraconazole, and the less active fluconazole and voriconazole. Five isolates (one S. globosa and four S. schenckii) were found to be itraconazole-resistant strains but, in general, there were no differences in the in vitro antifungal susceptibility profiles among the Sporothrix species.

  12. 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.

  13. 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

  14. 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

  15. In vitro antifungal susceptibility profile and correlation of mycelial and yeast forms of molecularly characterized Histoplasma capsulatum strains from India.

    PubMed

    Kathuria, Shallu; Singh, Pradeep K; Meis, Jacques F; Chowdhary, Anuradha

    2014-09-01

    The antifungal susceptibility profiles of the mycelial and yeast forms of 23 Histoplasma capsulatum strains from pulmonary and disseminated histoplasmosis patients in India are reported here. The MIC data of this dimorphic fungus had good agreement between both forms for azoles, amphotericin B, and caspofungin. Therefore, the use of mycelial inocula for H. capsulatum antifungal susceptibility testing is suggested, which is less time-consuming vis-à-vis the yeast form, which requires 6 to 8 weeks for conversion. PMID:24982084

  16. Comparison of agar dilution and antibiotic gradient strip test with broth microdilution for susceptibility testing of swine Brachyspira species.

    PubMed

    Mirajkar, Nandita S; Gebhart, Connie J

    2016-03-01

    Production-limiting diseases in swine caused by Brachyspira are characterized by mucohemorrhagic diarrhea (B. hyodysenteriae and "B. hampsonii") or mild colitis (B. pilosicoli), while B. murdochii is often isolated from healthy pigs. Emergence of novel pathogenic Brachyspira species and strains with reduced susceptibility to commonly used antimicrobials has reinforced the need for standardized susceptibility testing. Two methods are currently used for Brachyspira susceptibility testing: agar dilution (AD) and broth microdilution (BMD). However, these tests have primarily been used for B. hyodysenteriae and rarely for B. pilosicoli. Information on the use of commercial susceptibility testing products such as antibiotic gradient strips is lacking. Our main objective was to validate and compare the susceptibility results, measured as the minimum inhibitory concentration (MIC), of 6 antimicrobials for 4 Brachyspira species (B. hyodysenteriae, "B. hampsonii", B. pilosicoli, and B. murdochii) by BMD and AD (tiamulin, valnemulin, lincomycin, tylosin, and carbadox) or antibiotic gradient strip (doxycycline) methods. In general, the results of a high percentage of all 4 Brachyspira species differed by ±1 log2 dilution or less by BMD and AD for tiamulin, valnemulin, lincomycin, and tylosin, and by BMD and antibiotic gradient strip for doxycycline. The carbadox MICs obtained by BMD were 1-5 doubling dilutions different than those obtained by AD. BMD for Brachyspira was quicker to perform with less ambiguous interpretation of results when compared with AD and antibiotic gradient strip methods, and the results confirm the utility of BMD in routine diagnostics. PMID:26965233

  17. Standardized Method for In Vitro Antifungal Susceptibility Testing of Candida albicans Biofilms

    PubMed Central

    Ramage, Gordon; Vande Walle, Kacy; Wickes, Brian L.; López-Ribot, José L.

    2001-01-01

    Candida albicans is implicated in many biomaterial-related infections. Typically, these infections are associated with biofilm formation. Cells in biofilms display phenotypic traits that are dramatically different from those of their free-floating planktonic counterparts and are notoriously resistant to antimicrobial agents. Consequently, biofilm-related infections are inherently difficult to treat and to fully eradicate with normal treatment regimens. Here, we report a rapid and highly reproducible microtiter-based colorimetric assay for the susceptibility testing of fungal biofilms, based on the measurement of metabolic activities of the sessile cells by using a formazan salt reduction assay. The assay was used for in vitro antifungal susceptibility testing of several C. albicans strains grown as biofilms against amphotericin B and fluconazole and the increased resistance of C. albicans biofilms against these antifungal agents was demonstrated. Because of its simplicity, compatibility with a widely available 96-well microplate platform, high throughput, and automation potential, we believe this assay represents a promising tool for the standardization of in vitro antifungal susceptibility testing of fungal biofilms. PMID:11502517

  18. Variations in DNA subtype, antifungal susceptibility, and slime production among clinical isolates of Candida parapsilosis.

    PubMed

    Pfaller, M A; Messer, S A; Hollis, R J

    1995-01-01

    Candida parapsilosis is an important nosocomial pathogen that can proliferate in high concentrations of glucose and form biofilms on prosthetic materials. We investigated the genotypic diversity, slime production, and antifungal susceptibility among 60 isolates of C. parapsilosis from 44 patients and 10 patient care providers from five different medical centers. Molecular typing was performed using macrorestriction digest profiles with BssHII followed by pulsed-field gel electrophoresis (REAG) and by electrophoretic karyotyping (EK). Slime production was evaluated by growing the organisms in Sabouraud broth with 8% glucose and examining the walls of the tubes for the presence of an adherent slime layer. Antifungal susceptibility to amphotericin B, 5-fluorocytosine, fluconazole, and itraconazole was determined using National Committee for Clinical Laboratory Standards proposed standard methods. Overall 28 different DNA types were identified by REAG and EK methods. MIC90 values ranged from 0.12 microgram/ml for itraconazole to 1.0 microgram/ml for fluconazole and amphotericin B. Sixty-five percent of the isolates produced slime: 37% were moderately to strongly positive, 28% were weakly positive, and 35% were negative. Overall, 83% of blood and catheter isolates were slime positive versus 53% of isolates from all other sites (P < 0.05). These data underscore the genetic diversity and susceptibility of C. parapsilosis to antifungal agents. Slime production may be important in enabling C. parapsilosis to cause catheter-related bloodstream infections. PMID:7789100

  19. Susceptibilities of Candida albicans mouth isolates to antifungal agents, essentials oils and mouth rinses.

    PubMed

    Carvalhinho, Sara; Costa, Ana Margarida; Coelho, Ana Cláudia; Martins, Eugénio; Sampaio, Ana

    2012-07-01

    Forty Candida albicans strains isolated from patient's mouth with fixed orthodontic appliances were analyzed to their susceptibilities to antifungal agents, mouth rinses and essential oils. Susceptibility to fluconazole, econazole, miconazole and ketoconazole, amphotericin B and nystatin was assessed by the disk diffusion (DD) method based on the Clinical and Laboratory Standards Institute M44-A protocol, and by Etest (fluconazole and amphotericin B). The susceptibilities to mouth rinses and essential oils were also determined by the DD technique. All isolates tested were susceptible (S) to amphotericin B, nystatin and fluconazole. The overall concordance between the DD and the Etest was 100% for amphotericin and fluconazole. One isolate was resistant to econazole (2.5%) and the other to ketoconazole (2.5%). Econazole and ketoconazole had the highest percentages of susceptible dose dependent (SDD), 55 and 95%, respectively. Regarding to the susceptibility isolates profile, seven phenotypes were detected, and the 3 more represented (90% of the isolates) of them were SDD to one, two or three azoles. The study of mouth rinses showed a high variability of efficacy against C. albicans. The results showed that the isolates susceptibility to essential oils differed (P < 0.05). The profile activity was: cinnamon > laurel > mint > eucalyptus > rosemary > lemon > myrrh > tangerine. The main finding was that the susceptibility to cinnamon and laurel varied among the three more representative antifungal phenotypes (P < 0.05). The susceptibility of econazole-SDD isolates to cinnamon and lemon was higher than those of the econazole-S yeasts (P < 0.05). In contrast, econazole-SDD isolates were less affected by laurel than econazole-S counterparts (P < 0.05).

  20. Virulence Attributes and Antifungal Susceptibility Profile of Opportunistic Fungi Isolated from Ophthalmic Infections.

    PubMed

    Sav, Hafize; Ozdemir, Havva Gül; Altınbas, Rabiye; Kiraz, Nuri; Ilkit, Macit; Seyedmousavi, Seyedmojtaba

    2016-10-01

    Investigations of both virulence factors and antifungal susceptibility profiles are crucial for understanding the pathogenesis and prognosis of ophthalmic mycoses. In this study, we investigated the in vitro antifungal susceptibility of amphotericin B (AMB), voriconazole (VRC), and natamycin (NAT) against a set of 50 fungal isolates obtained from patients with ocular mycoses using the Clinical and Laboratory Standards Institute broth microdilution method. In addition, putative virulence factor, such as secretory phospholipases and proteinases, and biofilm formation activity were analyzed. The geometric means (GMs) of the minimum inhibitory concentrations (MICs) of the antifungals across all isolates were the following (in increasing order): VRC (0.70 μg/mL), AMB (0.81 μg/mL), and NAT (1.05 μg/mL). The highest activity against 14 Aspergillus strains was exhibited by VRC (GM MIC: 0.10 μg/mL), followed by AMB and NAT (GM MICs: 0.21 and 0.27 μg/mL), respectively. However, for 12 Fusarium spp., the GM MIC of VRC (2.66) was higher than those of NAT and AMB (GM MICs 1.3 and 0.8 μg/mL, respectively). Proteinase and phospholipase activity were observed in 30 % and 42 % of the isolates, respectively, whereas only 8 % of the isolates were able to produce biofilms. Phospholipase activity was observed in all Fusarium isolates, but not in any of the Aspergillus isolates. In contrast, biofilm-forming capability was detected in 25 % of the Fusarium isolates, but none of the Aspergillus isolates. The differences in the MICs of AMB, VRC, and NAT, biofilm-forming ability and proteinase and phospholipase activities among the isolates were not significant (p > 0.05). Overall, our study suggests no significant correlation between the antifungal susceptibility profiles and virulence attributes of ocular fungal isolates.

  1. 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

  2. Genetic relatedness and antifungal susceptibility profile of Candida albicans isolates from fungaemia patients.

    PubMed

    Costa-de-Oliveira, Sofia; Sousa, Inês; Correia, Alexandra; Sampaio, Paula; Pais, Célia; Rodrigues, Acácio Gonçalves; Pina-Vaz, Cidália

    2011-04-01

    A prospective study to assess fungaemia was conducted for 12 months at a Portuguese University Hospital. A total of 35 Candida albicans isolates obtained from 12 patients with fungaemia were compared by a multiplex PCR system using four microsatellite loci. Blood isolates were evaluated against concomitant isolates from urine, lower respiratory secretions and central venous catheters, as well as with successive isolates recovered from recurrent episodes of fungaemia. The data analyzed included the department of admission, underlying diseases and antifungal therapy. The susceptibility phenotypes of all isolates to amphotericin B, fluconazole, itraconazole, voriconazole and caspofungin were determined according to the CLSI M27-A3 protocol. We observed a high degree of similarity between successive blood isolates and between blood and concomitant isolates from other sites of the same patient. This is suggestive of the recurrence of fungaemia and was due to the same strain, possibly as a result of the failure of antifungal therapy. The genetic similarity observed between some strains isolated from different patients suggested the likelihood that they were hospital acquired. Distinct patients were infected by the same strain at different time periods, and an increase in antifungal resistance was observed over time for some of these strains. Hospital-acquired exogenous nosocomial infections can be associated with higher risks of antifungal resistance and need to be closely monitored. Particular attention should also be given to endogenous non-blood Candida isolates which can be critical in high risk patients, as they often can become invasive in immunodeficient individuals.

  3. 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

  4. Evaluation of agar dilution and broth microdilution methods to determine the disinfectant susceptibility.

    PubMed

    Wu, Guoyan; Yang, Qianru; Long, Mei; Guo, Lijuan; Li, Bei; Meng, Yue; Zhang, Anyun; Wang, Hongning; Liu, Shuliang; Zou, Likou

    2015-11-01

    A variety of disinfectants have been widely used in veterinary hygiene, food industries and environments, which could induce the development of bacterial resistance to disinfectants. The methods used to investigate antimicrobial effects of disinfectant vary considerably among studies, making comparisons difficult. In this study, agar dilution and broth microdilution methods were used to compare the antimicrobial activities of four quaternary ammonium compounds (QACs) against foodborne and zoonotic pathogens. The potential relationship between the presence of QACs resistance genes and phenotypic resistance to QACs was also investigated. Our results indicated that the minimum inhibitory concentrations (MICs) determined by two methods might be different depended upon different QACs and bacteria applied. Regardless of the testing methods, Klebsiella pneumoniae was more tolerant among Gram-negative strains to four QACs, followed by Salmonella and Escherichia coli. The agreement between MICs obtained by the two methods was good, for benzalkonium chloride (78.15%), didecyldimethylammonium chloride (DDAC) (82.35%), cetylpyridinium chloride (CTPC) (97.48%) and cetyltrimethylammonium bromide (CTAB) (99.16%), respectively. Among all Gram-negative bacteria, 94.55% (n=52) of qacEΔ1-positive strains showed higher MICs (512 mg l(-1)) to CTAB. The qacEΔ1 gene was highly associated (P<0.05) with the high MICs of QACs (⩾512 mg l(-1)). In addition, DDAC remained as the most effective disinfectant against both Gram-positive and Gram-negative bacteria. This is the first study that compared the agar dilution and broth microdilution methods to assess the antimicrobial activity of QACs. The study demonstrated the need to standardize method that would be used in evaluating QACs antimicrobial properties in the future.

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

    SciTech Connect

    Neuhof, Torsten . E-mail: t.neuhof@gmx.de; Seibold, Michael; Thewes, Sascha; Laue, Michael; Han, Chang-Ok; Hube, Bernhard; Doehren, Hans von

    2006-10-20

    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 the 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.

  6. [Regional laboratory network for surveillance of invasive fungal infections and antifungal susceptibility in Latin America].

    PubMed

    Cuenca-Estrella, Manuel; Rodríguez-Tudela, Juan L; Córdoba, Susana; Melhem, Marcia C; Szeszs, María W; Castañeda, Elizabeth; Martínez, Gerardo; Gabastou, Jean-Marc

    2008-02-01

    This article describes the general objectives of the Regional Laboratory Network for Surveillance of Invasive Fungal Infections and Antifungal Susceptibility in Latin America. Formation of the Network was coordinated by the Essential Medicines, Vaccines, and Health Technologies Unit of the Pan American Health Organization, with the technical and financial support of the National Center for Microbiology of the Carlos III Health Institute (Spain), and the technical support of the Microbiology Department of the Dr. C. Malbrán National Institute on Infectious Diseases (Argentina) and the Microbiology Unit of the Parasitology Service of the Adolfo Lutz Institute (Brazil). The Network's principle objectives are epidemiological surveillance of invasive fungal infections through detection of antifungal resistance and identification of emergent, invasive fungal infections; establishment of norms and common protocols for early diagnosis of mycoses; and strengthening coordination, communications, and transference mechanisms among countries. The Network must be gradually implemented and must include staff training, a systematic process for sharing technology, evaluation of diagnostic techniques, identification of fungal species, and standardized tests for antifungal susceptibility.

  7. Sentinel surveillance of invasive candidiasis in Spain: epidemiology and antifungal susceptibility.

    PubMed

    Nieto, M C; Tellería, O; Cisterna, R

    2015-01-01

    In order to know the epidemiology and the changes of antifungal resistance in invasive candidiasis (IC) we carried out this prospective study of Candida strains belonging to patients admitted to 26 Spanish hospitals from June 2011 to June 2012 diagnosed with IC. Clinical information and the identity of the Candida species were collected and antifungal susceptibility was tested using broth microdilution in five agents: amphotericin B, fluconazole, voriconazole, caspofungin and anidulafungin. A total of 705 cases-isolates were documented. Most of the patients suffered from candidemia and several underlying diseases and more than half of them were neutropenic or under immunosuppressive therapy, factors associated with higher mortality. Thirty percent of global mortality was documented. C. albicans was the most frequently isolated species, although an increase of non-C. albicans species was observed. Resistance to fluconazole was of 3.4%, lower than in previous years (6.3%). C. parapsilosis presented a higher MIC90 of echinocandins compared to other species.

  8. Mycotic Keratitis Due to Curvularia senegalensis and In Vitro Antifungal Susceptibilities of Curvularia spp.

    PubMed Central

    Guarro, Josep; Akiti, Tiyomi; Horta, Roberto Almada-; Morizot Leite-Filho, L. A.; Gené, Josepa; Ferreira-Gomes, Sueli; Aguilar, Carme; Ortoneda, Montserrat

    1999-01-01

    A case of mycotic keratitis due to Curvularia senegalensis is reported. This case represents the third known reported infection caused by this rare species. Fungal hyphae were detected in corneal scrapings, and repeated cultures were positive for this fungi. The patient was presumed cured after a corneal transplant and treatment with itraconazole, but the infection recurred and the patient is waiting for a keratoplasty. The in vitro antifungal susceptibilities of the case strain and another 24 strains belonging to seven species of Curvularia were tested for six antifungal agents. With the exception of flucytosine, and occasionally fluconazole, the other drugs assayed (amphotericin B, miconazole, itraconazole, and ketoconazole) were highly effective in vitro. PMID:10565956

  9. Molecular Characterization and In Vitro Antifungal Susceptibility of 316 Clinical Isolates of Dermatophytes in Iran.

    PubMed

    Ansari, Saham; Hedayati, Mohammad T; Zomorodian, Kamiar; Pakshir, Keyvan; Badali, Hamid; Rafiei, Abdollah; Ravandeh, Mostafa; Seyedmousavi, Seyedmojtaba

    2016-02-01

    Dermatophytosis is a common mycotic infection of the skin, nail, and hair, associated with major public health concern worldwide. Various species of dermatophytes show significant differences in susceptibility to antifungals. Here, we present the antifungal susceptibility of a large collection of molecularly identified dermatophyte isolates obtained from tropical region of south of Iran. A total of 9485 patients clinically suspected to have cutaneous fungal infections were examined. Dermatophytosis was confirmed in 1502 cases by direct microscopy and culture. Three hundred and sixteen isolates recovered in culture were identified to species level using PCR sequencing of ITS region and RFLP. Tinea corporis was the most prevalent type of clinical manifestation (35.2 %), followed by tinea cruris (17 %), tinea capitis (12.8 %), tinea pedis (11.3 %), tinea manuum (11 %), tinea unguium (6.9 %), and tinea barbae (5.8 %). Trichophyton interdigitale was the most common isolate (49.36 %), followed by Trichophyton rubrum (18.98 %), Epidermophyton floccosum (13.29 %), Microsporum canis (9.17 %), Arthroderma benhamiae (T. anamorph of A. benhamiae; 5.38 %), and Trichophyton tonsurans (3.79 %). Overall, irrespective of the geographical region, terbinafine was the most potent antifungal against all isolates, with an MIC range of 0.002-0.25 μg/mL, followed by itraconazole (0.004-0.5 μg/mL), griseofulvin (0.125-8 μg/mL), and fluconazole (4-128 μg/mL). Analysis of our data revealed a significant increase in the frequency of A.benhamiae, which definitely warrants further investigation to explore source of this infection in south of Iran. Moreover, terbinafine was the most effective antifungal against all isolates, in vitro. PMID:26369643

  10. Molecular Characterization and In Vitro Antifungal Susceptibility of 316 Clinical Isolates of Dermatophytes in Iran.

    PubMed

    Ansari, Saham; Hedayati, Mohammad T; Zomorodian, Kamiar; Pakshir, Keyvan; Badali, Hamid; Rafiei, Abdollah; Ravandeh, Mostafa; Seyedmousavi, Seyedmojtaba

    2016-02-01

    Dermatophytosis is a common mycotic infection of the skin, nail, and hair, associated with major public health concern worldwide. Various species of dermatophytes show significant differences in susceptibility to antifungals. Here, we present the antifungal susceptibility of a large collection of molecularly identified dermatophyte isolates obtained from tropical region of south of Iran. A total of 9485 patients clinically suspected to have cutaneous fungal infections were examined. Dermatophytosis was confirmed in 1502 cases by direct microscopy and culture. Three hundred and sixteen isolates recovered in culture were identified to species level using PCR sequencing of ITS region and RFLP. Tinea corporis was the most prevalent type of clinical manifestation (35.2 %), followed by tinea cruris (17 %), tinea capitis (12.8 %), tinea pedis (11.3 %), tinea manuum (11 %), tinea unguium (6.9 %), and tinea barbae (5.8 %). Trichophyton interdigitale was the most common isolate (49.36 %), followed by Trichophyton rubrum (18.98 %), Epidermophyton floccosum (13.29 %), Microsporum canis (9.17 %), Arthroderma benhamiae (T. anamorph of A. benhamiae; 5.38 %), and Trichophyton tonsurans (3.79 %). Overall, irrespective of the geographical region, terbinafine was the most potent antifungal against all isolates, with an MIC range of 0.002-0.25 μg/mL, followed by itraconazole (0.004-0.5 μg/mL), griseofulvin (0.125-8 μg/mL), and fluconazole (4-128 μg/mL). Analysis of our data revealed a significant increase in the frequency of A.benhamiae, which definitely warrants further investigation to explore source of this infection in south of Iran. Moreover, terbinafine was the most effective antifungal against all isolates, in vitro.

  11. 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.

  12. Antifungal Susceptibility Patterns of Candida Species Recovered from Endotracheal Tube in an Intensive Care Unit.

    PubMed

    Baghdadi, Elham; Khodavaisy, Sadegh; Rezaie, Sassan; Abolghasem, Sara; Kiasat, Neda; Salehi, Zahra; Sharifynia, Somayeh; Aala, Farzad

    2016-01-01

    Aims. Biofilms formed by Candida species which associated with drastically enhanced resistance against most antimicrobial agents. The aim of this study was to identify and determine the antifungal susceptibility pattern of Candida species isolated from endotracheal tubes from ICU patients. Methods. One hundred forty ICU patients with tracheal tubes who were intubated and mechanically ventilated were surveyed for endotracheal tube biofilms. Samples were processed for quantitative microbial culture. Yeast isolates were identified to the species level based on morphological characteristics and their identity was confirmed by PCR-RFLP. Antifungal susceptibility testing was determined according to CLSI document (M27-A3). Results. Ninety-five strains of Candida were obtained from endotracheal tubes of which C. albicans (n = 34; 35.7%) was the most frequently isolated species followed by other species which included C. glabrata (n = 24; 25.2%), C. parapsilosis (n = 16; 16.8%), C. tropicalis (n = 12; 12.6%), and C. krusei (n = 9; 9.4%). The resulting MIC90 for all Candida species were in increasing order as follows: caspofungin (0.5 μg/mL); amphotericin B (2 μg/mL); voriconazole (8.8 μg/mL); itraconazole (16 μg/mL); and fluconazole (64 μg/mL). Conclusion. Candida species recovered from endotracheal tube are the most susceptible to caspofungin.

  13. Antifungal Susceptibility Patterns of Candida Species Recovered from Endotracheal Tube in an Intensive Care Unit

    PubMed Central

    Baghdadi, Elham; Rezaie, Sassan; Abolghasem, Sara; Kiasat, Neda; Salehi, Zahra; Sharifynia, Somayeh

    2016-01-01

    Aims. Biofilms formed by Candida species which associated with drastically enhanced resistance against most antimicrobial agents. The aim of this study was to identify and determine the antifungal susceptibility pattern of Candida species isolated from endotracheal tubes from ICU patients. Methods. One hundred forty ICU patients with tracheal tubes who were intubated and mechanically ventilated were surveyed for endotracheal tube biofilms. Samples were processed for quantitative microbial culture. Yeast isolates were identified to the species level based on morphological characteristics and their identity was confirmed by PCR-RFLP. Antifungal susceptibility testing was determined according to CLSI document (M27-A3). Results. Ninety-five strains of Candida were obtained from endotracheal tubes of which C. albicans (n = 34; 35.7%) was the most frequently isolated species followed by other species which included C. glabrata (n = 24; 25.2%), C. parapsilosis (n = 16; 16.8%), C. tropicalis (n = 12; 12.6%), and C. krusei (n = 9; 9.4%). The resulting MIC90 for all Candida species were in increasing order as follows: caspofungin (0.5 μg/mL); amphotericin B (2 μg/mL); voriconazole (8.8 μg/mL); itraconazole (16 μg/mL); and fluconazole (64 μg/mL). Conclusion. Candida species recovered from endotracheal tube are the most susceptible to caspofungin.

  14. Antifungal Susceptibility Patterns of Candida Species Recovered from Endotracheal Tube in an Intensive Care Unit

    PubMed Central

    Baghdadi, Elham; Rezaie, Sassan; Abolghasem, Sara; Kiasat, Neda; Salehi, Zahra; Sharifynia, Somayeh

    2016-01-01

    Aims. Biofilms formed by Candida species which associated with drastically enhanced resistance against most antimicrobial agents. The aim of this study was to identify and determine the antifungal susceptibility pattern of Candida species isolated from endotracheal tubes from ICU patients. Methods. One hundred forty ICU patients with tracheal tubes who were intubated and mechanically ventilated were surveyed for endotracheal tube biofilms. Samples were processed for quantitative microbial culture. Yeast isolates were identified to the species level based on morphological characteristics and their identity was confirmed by PCR-RFLP. Antifungal susceptibility testing was determined according to CLSI document (M27-A3). Results. Ninety-five strains of Candida were obtained from endotracheal tubes of which C. albicans (n = 34; 35.7%) was the most frequently isolated species followed by other species which included C. glabrata (n = 24; 25.2%), C. parapsilosis (n = 16; 16.8%), C. tropicalis (n = 12; 12.6%), and C. krusei (n = 9; 9.4%). The resulting MIC90 for all Candida species were in increasing order as follows: caspofungin (0.5 μg/mL); amphotericin B (2 μg/mL); voriconazole (8.8 μg/mL); itraconazole (16 μg/mL); and fluconazole (64 μg/mL). Conclusion. Candida species recovered from endotracheal tube are the most susceptible to caspofungin. PMID:27642628

  15. Molecular epidemiology and antifungal susceptibility of Cryptococcus neoformans isolates from Ugandan AIDS patients.

    PubMed

    Pfaller, M; Zhang, J; Messer, S; Tumberland, M; Mbidde, E; Jessup, C; Ghannoum, M

    1998-11-01

    Little is known of the antifungal susceptibility patterns and molecular epidemiology of Cryptococcus neoformans from tropical regions. We studied 164 clinical isolates of C. neofomans from 120 Ugandan AIDS patients with cryptococcal meningitis by analyzing their electrophoretic karyotypes and antifungal susceptibility profiles. Computer-assisted analysis of karyotype patterns was performed to generate dendrograms. MICs of fluconazole and flucytosine were determined by reference methods. A total of 43 distinguishable DNA types were identified among the 164 isolates. Only 30 patients (25%) were infected with their own unique strain of c. neoformans, whereas 75% of the patients shared their infecting strain with at least one other patient. Among 17 patients with more than one CSF isolate of C. neoformans, sequential isolates were identical or highly related in 12 (71%) and were different in five patients (29%). The isolates were susceptible to both fluconazole and flucytosine and there were no instances in which a stepwise increase in either fluconazole or flucytosine MICs was observed among serial isolates. These findings suggest that the epidemiology of cryptococcal disease in AIDS patients from tropical regions may be somewhat different from that observed in more temperate climates.

  16. Antifungal Susceptibility Patterns of Candida Species Recovered from Endotracheal Tube in an Intensive Care Unit.

    PubMed

    Baghdadi, Elham; Khodavaisy, Sadegh; Rezaie, Sassan; Abolghasem, Sara; Kiasat, Neda; Salehi, Zahra; Sharifynia, Somayeh; Aala, Farzad

    2016-01-01

    Aims. Biofilms formed by Candida species which associated with drastically enhanced resistance against most antimicrobial agents. The aim of this study was to identify and determine the antifungal susceptibility pattern of Candida species isolated from endotracheal tubes from ICU patients. Methods. One hundred forty ICU patients with tracheal tubes who were intubated and mechanically ventilated were surveyed for endotracheal tube biofilms. Samples were processed for quantitative microbial culture. Yeast isolates were identified to the species level based on morphological characteristics and their identity was confirmed by PCR-RFLP. Antifungal susceptibility testing was determined according to CLSI document (M27-A3). Results. Ninety-five strains of Candida were obtained from endotracheal tubes of which C. albicans (n = 34; 35.7%) was the most frequently isolated species followed by other species which included C. glabrata (n = 24; 25.2%), C. parapsilosis (n = 16; 16.8%), C. tropicalis (n = 12; 12.6%), and C. krusei (n = 9; 9.4%). The resulting MIC90 for all Candida species were in increasing order as follows: caspofungin (0.5 μg/mL); amphotericin B (2 μg/mL); voriconazole (8.8 μg/mL); itraconazole (16 μg/mL); and fluconazole (64 μg/mL). Conclusion. Candida species recovered from endotracheal tube are the most susceptible to caspofungin. PMID:27642628

  17. Detection of intermediately vancomycin-susceptible and heterogeneous Staphylococcus aureus isolates: comparison of Etest and Agar screening methods.

    PubMed

    Riederer, K; Shemes, S; Chase, P; Musta, A; Mar, A; Khatib, R

    2011-06-01

    Detection of Staphylococcus aureus isolates with intermediate vancomycin susceptibility (VISA) and heteroresistance (hVISA) remains problematic. The population analysis profile/area under the curve (PAP/AUC) is the gold standard but is cumbersome. We compared the performance of two Etest screening methods (macromethod [MAC] and glycopeptide resistance detection [GRD]) plus brain heart infusion (BHI) agars supplemented with 3 (BHI-V3) or 4 (BHI-V4) mg/liter vancomycin in detecting hVISA and/or VISA phenotypes. Etest hVISA screenings were done in parallel for 485 saved methicillin-resistant S. aureus (MRSA) blood isolates according to the manufacturer's instructions. The PAP/AUC was measured for all isolates according to the modified method. PAP/AUC test isolate/Mu3 ratios of <0.9, 0.9 to 1.3, and >1.3 were considered positive for susceptible MRSA (S-MRSA), hVISA, and VISA, respectively. PAP/AUC revealed seven VISA and 33 hVISA phenotypes. MAC screening was positive for 30 (75.0%) hVISA/VISA and 49 (11.0%) S-MRSA isolates. GRD screening was positive for 28 (70.0%) hVISA/VISA and 63 (14.2%) S-MRSA isolates. Growth on BHI-V3 was noted in all hVISA/VISA and 24 (5.4%) S-MRSA isolates. Growth on BHI-V4 was noted in all VISA and four (12.1%) hVISA isolates. None of the S-MRSA isolates grew on BHI-V4 agar. The sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values were 75.0%, 89.0%, 38.0%, and 97.5% for MAC; 70.0%, 85.8%, 30.8%, and 97.0% for GRD; 100%, 94.6%, 62.5%, and 100% for BHI-V3; and 100, 99.2%, 63.6%, and 100% for BHI-V4 (for detecting VISA). These findings suggest that both Etest screening methods have excellent NPV, but positive results require confirmation. BHI-V3 and BHI-V4 agars provide more precise identification of hVISA and VISA, respectively; they may be reasonable alternatives to PAP/AUC.

  18. A case of Exophiala spinifera infection in Southern Brazil: Molecular identification and antifungal susceptibility.

    PubMed

    Daboit, Tatiane Caroline; Duquia, Rodrigo Pereira; Magagnin, Cibele Massotti; Mendes, Sandra Denise Camargo; Castrillón, Mauricio Ramírez; Steglich, Raquel; Dos Santos, Inajara Silveira; Vettorato, Gerson; Valente, Patrícia; Scroferneker, Maria Lúcia

    2012-01-01

    We report a case of an 80-year-old Brazilian man, farmer, with lesions on the dorsum of the hand. A direct mycological examination, cultivation and microculture slide observation was performed. The sequencing of ITS1-5.8S rDNA-ITS2 region was carried out and the etiological agent confirmed as Exophiala spinifera. The in vitro susceptibility of this isolate to antifungal agents alone and in combination was evaluated. This is the third case of phaeohyphomycosis caused by Exophiala spinifera in Brazil. PMID:24371743

  19. 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.

  20. Candidiasis in Pediatrics; Identification and In vitro Antifungal Susceptibility of the Clinical Isolates

    PubMed Central

    Mohammadi, R; Ataei, B

    2016-01-01

    Background Candida species are normal microflora of oral cavity, vagina, and gastrointestinal tract. They are the third most prevalent cause of pediatric health care–associated bloodstream fungal infection. This study aimed to provide an epidemiological feature of candidiasis and also presents an antifungal susceptibility profile of clinical Candida isolates among children. Materials and Methods During July 2013 to February 2015, 105 patients from different hospitals of Isfahan, Iran, were examined for candidiasis by phenotypic tests. Samples were obtained from nail clippings, blood, thrush, BAL, urine, oropharynx, skin, and eye discharge. The age range of patients was between 18 days to 16 years. Genomic DNA of isolates was extracted and ITS1-5.8SrDNA-ITS2 region was amplified by ITS1 and ITS2 primers. The PCR products were digested using the restriction enzyme MspI. Minimum inhibitory concentration (MICs) was determined using microdilution broth method according to the clinical and laboratory standards institute (CLSI) M27-A3 and M27-S4 documents. Results Forty-three patients (40.9%) had Candida infection.The most clinical strains were isolated from nail infections (39.5%), and candidemia (13.9%). Candida albicans was the most prevalent species (46.5%). MICs ranges for amphotericin B, fluconazole, and itraconazole were (0.025-0.75 µg/ml), (0.125-16 µg/ml), and (0.094-2 µg/ml), respectively. Conclusion Due to high incidence of Candida infections among children, increasing of fatal infection like candidemia, and emersion of antifungal resistance Candida isolates, early and precise identification of the Candida species and determination of antifungal susceptibility patterns of clinical isolates may lead to better management of the infection. PMID:27222702

  1. First description of Candida nivariensis in Brazil: antifungal susceptibility profile and potential virulence attributes

    PubMed Central

    Figueiredo-Carvalho, Maria Helena Galdino; Ramos, Livia de Souza; Barbedo, Leonardo Silva; Chaves, Alessandra Leal da Silva; Muramoto, Ilda Akemi; dos Santos, André Luis Souza; Almeida-Paes, Rodrigo; Zancopé-Oliveira, Rosely Maria

    2016-01-01

    This study evaluated the antifungal susceptibility profile and the production of potential virulence attributes in a clinical strain of Candida nivariensis for the first time in Brazil, as identified by sequencing the internal transcribed spacer (ITS)1-5.8S-ITS2 region and D1/D2 domains of the 28S of the rDNA. For comparative purposes, tests were also performed with reference strains. All strains presented low planktonic minimal inhibitory concentrations (PMICs) to amphotericin B (AMB), caspofungin (CAS), and voriconazole. However, our strain showed elevated planktonic MICs to posaconazole (POS) and itraconazole, in addition to fluconazole resistance. Adherence to inert surfaces was conducted onto glass and polystyrene. The biofilm formation and antifungal susceptibility on biofilm-growing cells were evaluated by crystal violet staining and a XTT reduction assay. All fungal strains were able to bind both tested surfaces and form biofilm, with a binding preference to polystyrene (p < 0.001). AMB promoted significant reductions (≈50%) in biofilm production by our C. nivariensis strain using both methodologies. This reduction was also observed for CAS and POS, but only in the XTT assay. All strains were excellent protease producers and moderate phytase producers, but lipases were not detected. This study reinforces the pathogenic potential of C. nivariensis and its possible resistance profile to the azolic drugs generally used for candidiasis management. PMID:26814644

  2. Trends in antifungal susceptibility and virulence of Candida spp. from the nasolacrimal duct of horses.

    PubMed

    Brilhante, Raimunda Sâmia Nogueira; Bittencourt, Paula Vago; Castelo-Branco, Débora de Souza Collares Maia; de Oliveira, Jonathas Sales; Alencar, Lucas Pereira de; Cordeiro, Rossana de Aguiar; Pinheiro, Mariana; Nogueira-Filho, Evilázio Fernandes; Pereira-Neto, Waldemiro de Aquino; Sidrim, José Júlio Costa; Rocha, Marcos Fábio Gadelha

    2016-02-01

    This was a cross-sectional study to investigate the antifungal susceptibility and production of virulence factors in strains of Candida isolated from the outlet and the lumen of the nasolacrimal duct of horses in the state of Ceará, Brazil. The samples were obtained from 103 horses. Sterile cotton swabs were used to collect the material from the outlet of the nasolacrimal duct and urethral probes, for the instillation of 2 ml of saline solution, were used to collect samples from the lumen of the nasolacrimal duct. A total of 77 Candida isolates were obtained, with C. famata, C. tropicalis, C. guilliermondii, and C. parapsilosis sensu lato as the most prevalent species. One isolate (C. glabrata) was resistant to caspofungin. One isolate was resistant only to fluconazole (C. parapsilosis sensu lato), 11 were resistant only to itraconazole (7 C. tropicalis, 2 C. guilliermondii, 1 C. famata, 1 C. parapsilosis sensu lato), while eight C. tropicalis showed resistance to both azoles. Overall, 28 isolates produced phospholipases and 12 produced proteases. These results highlight the importance of investigating the antifungal susceptibility and virulence trends of Candida spp. from the microbiota of the nasolacrimal duct of horses.

  3. Effectual detection of group B streptococci with reduced penicillin susceptibility (PRGBS) by commercially available methicillin-resistant-Staphylococcus aureus (MRSA)-selective agar.

    PubMed

    Fukigai, Shinako; Morimoto, Makiko; Kimura, Kouji; Doyama, Yo; Miyazaki, Akira; Kamiya, Chitose; Banno, Hirotsugu; Morishima, Eriko; Onoda, Tomohiro; Nagano, Noriyuki; Jin, Wanchun; Wachino, Jun-Ichi; Yamada, Keiko; Arakawa, Yoshichika

    2016-07-01

    We evaluated the feasibility and efficacy of a commercially available methicillin-resistant Staphylococcus aureus (MRSA)-selective agar, chromID(™) MRSA, to detect group B streptococci with reduced penicillin susceptibility (PRGBS) in this study. The results showed 72.4% (21/29) sensitivity and 98.4% (60/61) specificity to detect PRGBS using this method.

  4. [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

  5. [Neonatal Candida infections and the antifungal susceptibilities of the related Candida species].

    PubMed

    Altuncu, Emel; Bilgen, Hülya; Cerikçioğlu, Nilgün; Ilki, Arzu; Ulger, Nurver; Bakır, Mustafa; Akman, Ipek; Ozek, Eren

    2010-10-01

    Among nosocomial infections in the newborns, the incidence of fungal infections has been rising over the last decades. Fluconazole has been a new option for treatment however, expanded use of the drug brought up the development of resistance. In this study, species of the Candida isolates from neonates with candida infections, their antifungal susceptibilities and the effectiveness of the therapy were evaluated. All the species of Candida isolates from blood, urine and sterile body fluids of 54 neonates and their antifungal susceptibilities were evaluated retrospectively over the 13-year period. Demographic characteristics, risk factors, infection foci, Candida species causing infection and their in vitro susceptibilities for fluconazole (FCZ) and amphotericin B (AMB) and treatment responses were analyzed. The antifungal susceptibility testing of isolates was performed by microdilution technique. The median birth weight and gestational age of the study groups were 1735 (660-3990) g and 33 (24-40) weeks, respectively. Among the patients, 19 (35%) were term, while 35 (65%) were preterm [< 32 weeks n = 20 (37%), < 28 weeks n = 7 (13%)]. The percentage of low birth weight infants was 65% (42% was < 1500 g, 13% was < 1000 g). Candida spp. were isolated mostly from blood samples (63%), followed by urine (46%), cerebrospinal fluid (CSF; 5%), peritoneal fluid (3%) and endotracheal aspirate (2%). Multifocal growth was determined in 10 (18%) cases. The isolated species were C.albicans (n =36) as being the most common isolate followed by C.parapsilosis (n = 12), C.tropicalis (n = 1), C.kefyr (n = 1), C.lusitaniae (n = 1), C.pelluculosa (n = 1) and Candida spp. (n = 2). Prior antibiotic use, long term hospitalization, total parenteral nutrition and use of lipid solutions, prematurity and catheter use were determined as the most frequently associated factors causing candidal infections. A congenital abnormality, mainly myeloschisis and hydrocephaly, was detected in 18 (33%) of

  6. Neonatal invasive candidiasis in Tunisian hospital: incidence, risk factors, distribution of species and antifungal susceptibility.

    PubMed

    Ben Abdeljelil, J; Saghrouni, F; Nouri, S; Geith, S; Khammari, I; Fathallah, A; Sboui, H; Ben Saïd, M

    2012-11-01

    The aim of our study was to assess epidemiological features of neonatal invasive candidiasis in Farhat Hached hospital of Sousse, Tunisia, including incidence, risk factors, mortality, species distribution and antifungal susceptibility. Laboratory data from 1995 to 2010 and medical records of 127 invasive candidiasis cases were reviewed. We tested the susceptibility of 100 Candida sp isolates by using ATB fungus(®) 3 and to fluconazole by using E-test(®) strips. A total of 252 cases of neonatal invasive candidiasis occurred over the study period. The incidence increased 1.8-fold from 1995 to 2006 and decreased fourfold from 2007 to 2010. Candida albicans was the predominant species up to 2006 and a shift in the species spectrum was observed with increase of the non-albicans species mainly C. parapsilosis. The agreement between the ATB Fungus(®) and the E-test(®) for determining fluconazole susceptibility was high. All tested isolates were susceptible to fluconazole, flucytosine, amphotéricine B and voriconazole and the itraconazole resistance rate was 5%. The mortality rate was 63%. The invasive candidiasis incidence increased from 1995 to 2006 and decreased from 2007 to 2010. The spectrum of Candida species and the lack of fluconazole-resistant strains argue for the usefulness of fluconazole as an empiric treatment.

  7. Standardization of disk diffusion and agar dilution susceptibility tests for Neisseria gonorrhoeae: interpretive criteria and quality control guidelines for ceftriaxone, penicillin, spectinomycin, and tetracycline.

    PubMed Central

    Jones, R N; Gavan, T L; Thornsberry, C; Fuchs, P C; Gerlach, E H; Knapp, J S; Murray, P; Washington, J A

    1989-01-01

    A six-laboratory study developed a standardized method for determining the susceptibilities of Neisseria gonorrhoeae strains to penicillin, tetracycline, spectinomycin, and ceftriaxone. Three quality control organisms were also selected, and quality assurance guidelines were initially generated for the disk diffusion and agar dilution methods. The medium recommended for gonococcal susceptibility testing was GC agar with a defined "XV-like" supplement. The supplement should be free of cysteine, a component implicated in the inactivation of some newer beta-lactam compounds. Penicillin, tetracycline, spectinomycin, and ceftriaxone were stable in agar plates stored at 3 to 5 degrees C for at least 2 weeks. Numerous GC agar and drug disk lots were used during the trials without significant variation in test results. Several other gonococcal strains were recommended for additional medium quality assurance. The disk quality control zone limits were established for N. gonorrhoeae ATCC 49226 (formerly CDC F-18) and Staphylococcus aureus ATCC 25923. MIC quality control ranges were also developed for N. gonorrhoeae ATCC 49226 and S. aureus ATCC 29213. The interpretive criteria for penicillin were as follows: susceptibility, greater than or equal to 47 mm (diameter of inhibition zone) (less than or equal to 0.06 micrograms/ml [MIC]); resistance, less than or equal to 26 mm (greater than or equal to 2 micrograms/ml). For tetracycline they were as follows: susceptibility, greater than or equal to 38 mm (less than or equal to 0.25 microgram/ml); resistance, less than or equal to 30 mm (greater than or equal to 2 micrograms/ml). For spectinomycin they were as follows: susceptibility, >/= 18 mm (/= 128 micrograms/ml). For ceftriaxone susceptibility, the criterion was >/= 35 mm (

  8. Agar Diffusion Procedures for Susceptibility Testing of Malassezia pachydermatis: Evaluation of Mueller-Hinton Agar Plus 2 % Glucose and 0.5 µg/ml Methylene Blue as the Test Medium.

    PubMed

    Pasquetti, M; Chiavassa, E; Tizzani, P; Danesi, P; Peano, A

    2015-10-01

    Aim of this study was to verify whether Mueller-Hinton agar supplemented with 2 % glucose and methylene blue (MH-GM), which is used for disk diffusion susceptibility testing of Candida species by the Clinical and Laboratory Standards Institute, is suitable for testing Malassezia pachydermatis. A variant of the disk diffusion procedure utilizing a 9-mm tablet was used to test 31 isolates against clotrimazole and miconazole using MH-GM as test medium. The MH-GM agar optimally supported the growth of all M. pachydermatis isolates, provided that the yeast inoculum was prepared with a lipid source (Tween 40 and 80). Zone edges were frequently definite and clear, facilitating the measurement of zone size and minimizing subjectivity. The inhibition zones correlated with MIC values obtained in a broth dilution assay. The agar diffusion method with MH-GM as the test medium appears as a suitable procedure for testing the susceptibility of M. pachydermatis to CTZ and MCZ in clinical laboratories. This test format may allow processing a large number of isolates in epidemiological studies. This may in turn facilitate clarifying to what extent the problem "drug resistance" accounts for cases of treatment failure in dogs with Malassezia otitis and dermatitis. PMID:26138434

  9. Antifungal Susceptibility in Serum and Virulence Determinants of Candida Bloodstream Isolates from Hong Kong

    PubMed Central

    Seneviratne, Chaminda J.; Rajan, Suhasini; Wong, Sarah S. W.; Tsang, Dominic N. C.; Lai, Christopher K. C.; Samaranayake, Lakshman P.; Jin, Lijian

    2016-01-01

    Candida bloodstream infections (CBI) are one of the most common nosocomial infections globally, and they account for a high mortality rate. The increasing global prevalence of drug-resistant Candida strains has also been posing a challenge to clinicians. In this study, we comprehensively evaluated the biofilm formation and production of hemolysin and proteinase of 63 CBI isolates derived from a hospital setting in Hong Kong as well as their antifungal susceptibility both in the presence and in the absence of human serum, using standard methodology. Candida albicans was the predominant species among the 63 CBI isolates collected, and non-albicans Candida species accounted for approximately one third of the isolates (36.5%). Of them, Candida tropicalis was the most common non-albicans Candida species. A high proportion (31.7%) of the CBI isolates (40% of C. albicans isolates, 10% of C. tropicalis isolates, 11% of C. parapsilosis isolates, and 100% of C. glabrata isolates) were found to be resistant to fluconazole. One of the isolates (C. tropicalis) was resistant to amphotericin B. A rising prevalence of drug-resistance CBI isolates in Hong Kong was observed with reference to a previous study. Notably, all non-albicans Candida species, showed increased hemolytic activity relative to C. albicans, whilst C. albicans, C. tropicalis, and C. parapsilosis exhibited proteinase activities. Majority of the isolates were capable of forming mature biofilms. Interestingly, the presence of serum distorted the yeast sensitivity to fluconazole, but not amphotericin B. Taken together, our findings demonstrate that CBI isolates of Candida have the potential to express to varying extent their virulence attributes (e.g., biofilm formation, hemolysin production, and proteinase activity) and these, together with perturbations in their antifungal sensitivity in the presence of serum, may contribute to treatment complication in candidemia. The effect of serum on antifungal activity

  10. Invasive candidiasis in Pakistan: clinical characteristics, species distribution and antifungal susceptibility

    PubMed Central

    Farooqi, J. Q.; Jabeen, K.; Saeed, N.; Iqbal, N.; Malik, B.; Lockhart, S. R.; Zafar, A.; Brandt, M. E.; Hasan, R.

    2015-01-01

    This study reports for the first time, to our knowledge, descriptive epidemiological data for 18 invasive Candida isolates from Pakistan, including species identification and antifungal susceptibility against fluconazole, itraconazole, voriconazole, caspofungin, micafungin, anidulafungin and amphotericin. Risk factors for invasive candidiasis (IC) were determined for 96 patients from Karachi, Pakistan. In adults and neonates, Candida tropicalis (38 and 36 %, respectively) was the most common species, followed in adults by Candida parapsilosis (17.8 %), Candida glabrata (15.9 %) and Candida albicans (12.3 %). C. albicans (21 %) was the second most common in neonates. In children, C. albicans (31.9 %), C. tropicalis (26.4 %) and C. parapsilosis (19.4 %) were the most common. C. albicans IC was significantly associated with paediatric age [crude odds ratio (COR) 3.46, 95% confidence interval (CI) 1.63–7.32]. Rare species made up 17.5% of the total isolates studied. Resistance to fluconazole was seen in C. glabrata (15.0%) and Candida krusei (100.0%). Only one isolate (C. glabrata) was resistant to all three echinocandins. Low MICs of fluconazole for 98% (184/188) of isolates tested support its continued use as an empiric therapy for IC. Non-C. albicans IC was associated with the use of β lactam inhibitor combinations (COR 3.16, 95% CI 1.05–9.57). Use of healthcare devices was documented in 85.4% of IC patients, whilst 75.0% had been admitted to special care units. Surprisingly, 66.7% of patients with IC were not obviously immunosuppressed. The high frequency of modifiable risk factors in this population indicates that candidaemia can be reduced with stringent antibiotic and infection control measures. These data will be useful for empiric selection of antifungals in Karachi, and contribute to global assessments of antifungal resistance. PMID:23105021

  11. Identification and Antifungal Susceptibility of Penicillium-Like Fungi from Clinical Samples in the United States.

    PubMed

    Guevara-Suarez, Marcela; Sutton, Deanna A; Cano-Lira, José F; García, Dania; Martin-Vicente, Adela; Wiederhold, Nathan; Guarro, Josep; Gené, Josepa

    2016-08-01

    Penicillium species are some of the most common fungi observed worldwide and have an important economic impact as well as being occasional agents of human and animal mycoses. A total of 118 isolates thought to belong to the genus Penicillium based on morphological features were obtained from the Fungus Testing Laboratory at the University of Texas Health Science Center in San Antonio (United States). The isolates were studied phenotypically using standard growth conditions. Molecular identification was made using two genetic markers, the internal transcribed spacer (ITS) and a fragment of the β-tubulin gene. In order to assess phylogenetic relationships, maximum likelihood and Bayesian inference assessments were used. Antifungal susceptibility testing was performed according to CLSI document M38-A2 for nine antifungal drugs. The isolates were identified within three genera, i.e., Penicillium, Talaromyces, and Rasamsonia The most frequent species in our study were Penicillium rubens, P. citrinum, and Talaromyces amestolkiae The potent in vitro activity of amphotericin B (AMB) and terbinafine (TRB) and of the echinocandins against Penicillium and Talaromyces species might offer a good therapeutic alternative for the treatment of infections caused by these fungi.

  12. 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.

  13. 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.

  14. Evaluation of Virulence Factors and Antifungal Susceptibility in Yeast Isolates from Postmortem Specimens.

    PubMed

    Yagmur, Gulhan; Sav, Hafize; Ziyade, Nihan; Elgormus, Neval; Sen, Sumeyye; Akkoyun Bilgi, Esma; Atan, Yusuf; Buyuk, Yalcin; Kiraz, Nuri

    2016-07-01

    Invasive fungal infections are a leading cause of morbidity and mortality in immunocompromised patients, especially in cases requiring a prolonged stay in the intensive care unit. A total of 99 yeast strains were isolated from 42 postmortem cases. In this study, virulence factors and antifungal susceptibility of these species were evaluated. The isolates were identified as Candida albicans (54), C. tropicalis (15), C. glabrata (12), C. parapsilosis (6), C. lipolytica (3), C. utilis (3), C. krusei (2), C. kefyr (1), and Cryptococcus neoformans (3). The most commonly isolated species was C. albicans, and no resistant species were determined. Despite the equal number of specimens, no secretion of significant virulence factors was associated with the postmortem specimen in the Candida species. Postmortem fungal investigations in forensic autopsies are useful in explaining cause of death in such cases, also may lead to protocols for the treatment of fungal infections and contribute to fungal pathogenesis and epidemiological data. PMID:27364280

  15. Phylogeny of the clinically relevant species of the emerging fungus Trichoderma and their antifungal susceptibilities.

    PubMed

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

    2014-06-01

    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.

  16. 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

  17. Candida urinary tract infection and Candida species susceptibilities to antifungal agents.

    PubMed

    Osawa, Kayo; Shigemura, Katsumi; Yoshida, Hiroyuki; Fujisawa, Masato; Arakawa, Soichi

    2013-11-01

    The purpose of this study is to review Candida isolation from urine of urinary tract infection (UTI) patients over the recent 3 years at the Kobe University Hospital. We recorded the type of strain, the department where the patient was treated such as the intensive care unit (ICU), and combined isolation of Candida with other microorganisms. We investigated Candida isolation and susceptibilities to antifungal agents and analyzed the risk factors for combined isolation with other microorganisms. The most frequently isolated Candida was Candida albicans, which showed good (100%) susceptibilities to 5-fluorocytosine (5-FC) and fluconazole (FLCZ) but not to voriconazole (VRCZ), followed by C. glabrata. ICU was the greatest source of Candida-positive samples, and the most relevant underlying diseases of ICU patients were pneumonia followed by renal failure and post liver transplantation status. Combined isolation with other bacteria was seen in 27 cases (42.9%) in 2009, 25 (33.3%) in 2010 and 31 (31.3%) in 2011 and comparatively often seen in non-ICU patients. Other candidas than C. albicans showed significantly decreased susceptibility to FLCZ over these 3 years (P=0.004). One hundred (97.1%) of 103 ICU cases were given antibiotics at the time of Candida isolation, and the most often used antibiotics were cefazolin or meropenem. In conclusion, C. albicans was representatively isolated in Candida UTI and showed good susceptibilities to 5-FC, FLCZ and VRCZ, but other candidas than C. albicans showed significantly decreased susceptibility to FLCZ in the change of these 3 years.

  18. Clinical evaluation of a frozen commercially prepared microdilution panel for antifungal susceptibility testing of seven antifungal agents, including the new triazoles posaconazole, ravuconazole, and voriconazole.

    PubMed

    Pfaller, M A; Diekema, D J; Messer, S A; Boyken, L; Huynh, H; Hollis, R J

    2002-05-01

    A commercially prepared frozen broth microdilution panel (Trek Diagnostic Systems, Westlake, Ohio) was compared with a reference microdilution panel for antifungal susceptibility testing of two quality control (QC) strains and 99 clinical isolates of Candida spp. The antifungal agents tested included amphotericin B, flucytosine, fluconazole, itraconazole, posaconazole, ravuconazole, and voriconazole. Microdilution testing was performed according to NCCLS recommendations. MIC endpoints were read visually after 48 h of incubation and were assessed independently for each microdilution panel. The MICs for the QC strains were within published limits for both the reference and Trek microdilution panels. Discrepancies among MIC endpoints of no more than 2 dilutions were used to calculate the percent agreement. Acceptable levels of agreement between the Trek and reference panels were observed for all antifungal agents tested against the 99 clinical isolates. The overall agreement for each antifungal agent ranged from 96% for ravuconazole to 100% for amphotericin B. The Trek microdilution panel appears to be a viable alternative to frozen microdilution panels prepared in-house. PMID:11980944

  19. Candiduria in children and susceptibility patterns of recovered Candida species to antifungal drugs in Ahvaz

    PubMed Central

    Seifi, Zahra; Azish, Maryam; Salehi, Zahra; Zarei Mahmoudabadi, Ali; Shamsizadeh, Ahmad

    2013-01-01

    Background: Candiduria presents as an increasingly common nosocomial infection, which may involves urinary tract. Spectrum of disease is varying from asymptomatic candiduria to clinical sepsis. Disease is most commonly caused by Candida albicans. Objectives: The aim of the present study was to determine the frequency of candiduria in children attending Abuzar Pediatrics Hospital. Patients and Methods: Urine samples were collected from 402 patients attending to the Abuzar Pediatrics Hospital, Ahvaz. 10µl of each urine sample was cultured on CHROMagar Candida plates and incubated at 37°C. Ketoconazole, amphotericine B, clotrimazole, fluconazole, miconazole and nystatin disks were used for determination of susceptibility. Results: In the present study, 402 patients with the age range <1-14 years were sampled (59.2% males and 40.8% females). Prevalence of Candida among enrolled patients was found to be 5.2% (71.4% males and 28.6% females). In our study C. albicans was identified in 19 cases as the most common yeast followed by nine C. glabrata and one C. krusei. Urine cultures were yielded more than 10000 CFU/ml in 14.3% of the cases followed by 600-10000 CFU/ml (28.5%) and 100-600 CFU/ml (57.2%). Antifungal susceptibility testing revealed that only one isolate of C. glabrata and seven isolates of C. albicans were resistant to nystatin and ketoconazole, respectively.  However, all tested isolates were resistance to fluconazole. Conclusion: Asymptomatic candiduria is relatively more prevalent among children in Ahvaz and the most common agent is C. albicans. In addition, isolated Candida species were sensitive to use antifungals, with exception to fluconazole. PMID:24475438

  20. Multicenter evaluation of a broth macrodilution antifungal susceptibility test for yeasts.

    PubMed Central

    Fromtling, R A; Galgiani, J N; Pfaller, M A; Espinel-Ingroff, A; Bartizal, K F; Bartlett, M S; Body, B A; Frey, C; Hall, G; Roberts, G D

    1993-01-01

    Thirteen laboratories collaborated to optimize interlaboratory agreement of results of a broth macrodilution procedure for testing three classes of antifungal drugs against pathogenic yeasts. The activities of amphotericin B, flucytosine, and ketoconazole were tested against 100 coded isolates of Candida albicans, Candida tropicalis, Candida parapsilosis, Candida lusitaniae, Torulopsis (Candida) glabrata, and Cryptococcus neoformans. Two starting yeast inoculum sizes (5 x 10(4) and 2.5 x 10(3) cells per ml) were compared, and readings were taken after 24 and 48 h of incubation. All other test conditions were standardized. The resultant turbidities in all tubes were estimated visually on a scale from 0 to 4+ turbidity, and MIC-0, MIC-1, and MIC-2 were defined as the lowest drug concentrations that reduced growth to 0, 1+, or 2+ turbidity, respectively. For flucytosine, agreement among laboratories varied between 57 and 87% for different inocula, times of incubation, and end point criteria. Agreement was maximized (85%) when the lower inoculum was incubated for 2 days and the MICs were defined as 1+ turbidity or less. For amphotericin B, variations in test conditions produced much smaller differences in interlaboratory agreement. For ketoconazole, interlaboratory agreement was poorer by all end point criteria. However, MIC-2 endpoints distinguished T. glabrata as resistant compared with the other species. Overall, the studies indicated that readings from the lower inoculum obtained on the second day of reading result in the greatest interlaboratory agreement. In combination with data from previous multicenter studies (National Committee for Clinical Laboratory Standards, Antifungal Susceptibility Testing: Committee Report, Vol. 5, No. 17, 1988; M. A. Pfaller, L. Burmeister, M. S. Bartlett, and M. G. Rinaldi, J. Clin. Microbiol. 26:1437-1441, 1988; M. A. Pfaller, M. G. Rinaldi, J. N. Galgiani, M. S. Bartlett, B.A. Body, A. Espinel-Ingroff, R.A. Fromtling, G.S. Hall, C

  1. Prevalence and antifungal susceptibility of Candida parapsilosis complex isolates collected from oral cavities of HIV-infected individuals.

    PubMed

    Moris, D V; Melhem, M S C; Martins, M A; Souza, L R; Kacew, S; Szeszs, M W; Carvalho, L R; Pimenta-Rodrigues, M V; Berghs, H A M; Mendes, R P

    2012-12-01

    At present, few data are available on the prevalence and antifungal susceptibility of Candida parapsilosis complex isolates from HIV-infected individuals. The C. parapsilosis complex comprises three species, C. parapsilosis sensu stricto, C. metapsilosis and C. orthopsilosis. Fifteen of 318 Candida isolates were identified as members of the C. parapsilosis complex by PCR and restriction fragment length polymorphism (RFLP). The prevalence of C. parapsilosis complex isolates was 4.7 %, 2.2 % being identified as C. parapsilosis sensu stricto and 2.5 % as C. metapsilosis, while no C. orthopsilosis was isolated. This is believed to be the first study that has identified isolates of C. metapsilosis obtained from the oral cavity of HIV-infected individuals. Antifungal susceptibility tests indicated that all the isolates were susceptible to amphotericin B (AMB), fluconazole (FLC), ketoconazole (KTC), itraconazole (ITC), voriconazole (VRC) and caspofungin (CASPO). Although isolates of C. parapsilosis sensu stricto and C. metapsilosis were susceptible to FLC, isolates of C. metapsilosis showed a tendency for higher MICs (≥1.0 µg ml(-1)). Based upon the frequency of candidiasis and the fact that certain isolates of the C. parapsilosis complex respond differently to FLC therapy, our data may be of therapeutic relevance with respect to susceptibility and potential resistance to specific antifungal agents. Our data suggest that C. metapsilosis can be a human commensal; its importance as a pathogen has yet to be confirmed. PMID:22956748

  2. 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.

  3. Identification of Candida species and susceptibility testing with Sensititre YeastOne microdilution panel to 9 antifungal agents

    PubMed Central

    Kucukates, Emine; Gultekin, Nuh N.; Alisan, Zeynep; Hondur, Nur; Ozturk, Recep

    2016-01-01

    Objectives: To determine the species incidence and susceptibility pattern to 9 antifungal agents of yeasts isolated from various clinical specimens of colonized or infected patients treated in the coronary and surgical intensive care units (ICU). Methods: A total of 421 ICU patients were treated at the Cardiology Institute, Istanbul University, Istanbul, Turkey between June 2013 and May 2014, and 44 Candida species were isolated from blood, urine, endotracheal aspiration fluid, sputum, and wounds of 16 ICU patients. Identification of Candida was performed using CHROMagar. Antifungal susceptibility was determined by a Sensititre YeastOne colorimetric microdilution panel. Results: Candida albicans (C. albicans) was the most commonly observed microorganism 23 (54%); the other microorganisms isolated were Candida tropicalis 12 (27%), Candida glabrata 5 (11%), Candida parapsilosis 1 (2%), Candida lusitaniae 1 (2%), Candida sake 1 (2%), and Geotrichum capitatum 1 (2%). All isolates were susceptible to amphotericin B and 5-flucytosine. Geotrichum capitatum excepted, the other isolates were also susceptible to anidulafungin, micafungin, and caspofungin. Candida parapsilosis was found to be susceptible to all the studied antifungals. High MIC rates for azole group of antifungal drugs were found for C. albicans, C. tropicalis, and C. glabrata. The rate of colonisation was 3.8% (16/421). Only 0.7% (3/421) patients out of a total of 421 developed candidemia. Conclusion: We found that the yeast colonization and infection rates of patients in our ICUs are very low. Candida albicans is still the most common species. We detected a decreasing susceptibility to azole compounds. PMID:27381534

  4. 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

  5. Veronaea botryosa: molecular identification with amplified fragment length polymorphism (AFLP) and in vitro antifungal susceptibility.

    PubMed

    Badali, Hamid; Yazdanparast, Seyed Amir; Bonifaz, Alexandro; Mousavi, Bita; de Hoog, G Sybren; Klaassen, Corné H W; Meis, Jacques F

    2013-06-01

    Inter- and intraspecific genomic variability of 18 isolates of Veronaea botryosa originating from clinical and environmental sources was studied using amplified fragment length polymorphism (AFLP). The species was originally described from the environment, but several severe cases of disseminated infection in apparently healthy individuals have been reported worldwide. All tested strains of V. botryosa, identified on the basis of sequencing and phenotypic and physiological criteria prior to our study, were confirmed by AFLP analysis, yielding a clear separation of V. botryosa as a rather homogeneous group from related species. In vitro antifungal susceptibility testing resulted in MIC90s across all strains in increasing order posaconazole (0.25 μg/ml), itraconazole (1 μg/ml), voriconazole (4 μg/ml), terbinafine (4 μg/ml), caspofungin (8 μg/ml), anidulafungin (8 μg/ml), isavuconazole (16 μg/ml), amphotericin B (16 μg/ml), and fluconazole (32 μg/ml). Overall, the isolates showed a uniform pattern of low MICs of itraconazole and posaconazole, but high MICs for remaining agents. The echinocandins (caspofungin and anidulafungin) had no activity against V. botryosa. There was no statistically significant difference between susceptibilities of environmental (n = 11) and clinical (n = 7) isolates of V. botryosa (P > 0.05).

  6. Antimicrobial susceptibility testing for Helicobacter pylori isolates from Brazilian children and adolescents: Comparing agar dilution, E-test, and disk diffusion

    PubMed Central

    Ogata, Silvio Kazuo; Gales, Ana Cristina; Kawakami, Elisabete

    2014-01-01

    Antimicrobial susceptibility testing for Helicobacter pylori is increasingly important due to resistance to the most used antimicrobials agents. Only agar dilution method is approved by CLSI, but it is difficult to perform routinely. We evaluated the reliability of E-test and disk diffusion comparing to agar dilution method on Helicobacter pylori antimicrobial susceptibility testing. Susceptibility testing was performed for amoxicillin, clarithromycin, furazolidone, metronidazole and tetracycline using E-test, disk-diffusion and agar dilution method in 77 consecutive Helicobacter pylori strains from dyspeptic children and adolescents. Resistance rates were: amoxicillin - 10.4%, 9% and 68.8%; clarithromycin - 19.5%, 20.8%, 36.3%; metronidazole - 40.2%33.7%, 38.9%, respectively by agar dilution, E-test and disk diffusion method. Furazolidone and tetracycline showed no resistance rates. Metronidazole presented strong correlation to E-test (r = 0.7992, p < 0.0001) and disk diffusion method (r=-0.6962, p < 0.0001). Clarithromycin presented moderate correlation to E-test (r = 0.6369, p < 0.0001) and disk diffusion method (r=−0.5656, p < 0.0001). Amoxicillin presented weak correlation to E-test (r = 0.3565, p = 0.0015) and disk diffusion (r=−0.3565, p = 0.0015). Tetracycline presented weak correlation with E-test (r = 0.2346, p = 0.04) and furazolidone to disk diffusion (r=−0.0288, p = 0.8038). E-test presented better agreement with gold standard. It is an easy and reliable method for Helicobacter pylori susceptibility testing. Disk diffusion method presented high disagreement and high rates of major errors. PMID:25763052

  7. A case of relapsed chromoblastomycosis due to Fonsecaea monophora: antifungal susceptibility and phylogenetic analysis.

    PubMed

    Daboit, Tatiane Caroline; Magagnin, Cibele Massotti; Heidrich, Daiane; Castrillón, Mauricio Ramírez; Mendes, Sandra Denise Camargo; Vettorato, Gerson; Valente, Patrícia; Scroferneker, Maria Lúcia

    2013-08-01

    Chromoblastomycosis is a chronic cutaneous and subcutaneous mycosis. The management of this infection continues to be challenging because there is no consensus on the therapeutic regimen. We report here a case of a 69-year-old male patient with cauliflower-like lesions on his left leg and foot. He had already been treated with itraconazole at a dose of 200 mg/day for 5 months, with mycological cure for all the affected areas. However, the lesions relapsed at both sites, and treatment with itraconazole was resumed at the dose previously used. Initially, direct mycological examination, cultural, and microculture slide observation were performed. Afterward, sequencing of the ITS1-5.8S rDNA-ITS2 region of the fungal DNA and evaluation of its susceptibility to antifungal agents alone and in combination were performed. In direct mycological examination, the presence of sclerotic cells was verified, and the fungus was identified as Fonsecaea based on cultural and microscopic examinations. Identification as Fonsecaea monophora was confirmed after sequencing of the ITS region and phylogenetic analysis. The isolate was susceptible to itraconazole and terbinafine. The combinations of amphotericin B and terbinafine and terbinafine and voriconazole were synergistic. The use of drugs for which the causative agent is susceptible to singly or in combination may be an alternative for the treatment of mycosis. Furthermore, the identification of the agent by molecular techniques is important for epidemiological purposes. To the best of our knowledge, this is the first case of relapsed chromoblastomycosis caused by F. monophora in Brazil. PMID:23645135

  8. Antifungal susceptibility patterns of a global collection of fungal isolates: results of the SENTRY Antifungal Surveillance Program (2013).

    PubMed

    Castanheira, Mariana; Messer, Shawn A; Rhomberg, Paul R; Pfaller, Michael A

    2016-06-01

    Among 1846 fungal clinical isolates from 31 countries, echinocandin resistance in Candida spp. ranged from 0.0% to 2.8% (highest for anidulafungin versus Candida glabrata), and fluconazole resistance was noted among 11.9% and 11.6% of the C. glabrata and Candida tropicalis, respectively. Two isolates of Aspergillus fumigatus displayed elevated MICs for itraconazole and carried cyp51a mutations encoding TR34 L98H. All Cryptococcus neoformans had azole MIC values below epidemiological cutoff values. The increasing resistance among certain species and more frequent reports of breakthrough infections in patients undergoing antifungal therapy highlights the importance of antifungal surveillance to guide therapy for patients with invasive fungal infections. PMID:27061369

  9. 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. PMID:26868903

  10. Agreement of Direct Antifungal Susceptibility Testing from Positive Blood Culture Bottles with the Conventional Method for Candida Species

    PubMed Central

    Kumar, Haresh; Farooqi, Joveria; Mehboob, Raunaq; Brandt, Mary E.; Zafar, Afia

    2015-01-01

    Early availability of antifungal susceptibilities can ensure timely institution of targeted therapy in candidemia, which can improve patient outcomes. This study prospectively determines the agreement between the results of direct testing of antifungal susceptibilities from blood culture bottles by disk diffusion and Etest and the results of standardized susceptibility testing methods; direct testing would allow susceptibility results to be available 1 to 2 days earlier. A total of 104 blood cultures with different Candida species (28% C. albicans, 27% C. parapsilosis, 26% C. tropicalis, etc.) were evaluated between January 2012 and May 2013 for agreement of fluconazole, voriconazole, and amphotericin B susceptibility results by disk diffusion. Agreement in MICs obtained by Etest was determined for fluconazole (21 isolates), voriconazole (28 isolates), amphotericin (29 isolates), and caspofungin (29 isolates). The kappa scores for categorical agreement were highest for fluconazole by disk diffusion (0.902, standard error [SE] = 0.076) and Etest (1.00, SE = 0.218) and for amphotericin B by disk diffusion (1.00, SE = 0.098). The Pearson correlation (r) of zone diameters was strongest for fluconazole (0.69) and amphotericin (0.70) and moderate for voriconazole (0.60), and the Pearson correlation of MICs was strongest for fluconazole (0.94) and caspofungin (0.88). However, the moderate correlation of amphotericin MICs with zone diameters (−0.42) precludes the use of amphotericin B disk diffusion for susceptibility testing. There were no very major errors; however, there were 1 (1%) major and 5 (4.8%) minor errors with disk diffusion and 4 (13.3%) minor errors with Etest. Thus, antifungal disk diffusion directly from blood culture bottles is a rapid and easy method for fluconazole and voriconazole susceptibility testing for timely tailoring of candidemia therapy. PMID:26607985

  11. Agreement of Direct Antifungal Susceptibility Testing from Positive Blood Culture Bottles with the Conventional Method for Candida Species.

    PubMed

    Jabeen, Kauser; Kumar, Haresh; Farooqi, Joveria; Mehboob, Raunaq; Brandt, Mary E; Zafar, Afia

    2016-02-01

    Early availability of antifungal susceptibilities can ensure timely institution of targeted therapy in candidemia, which can improve patient outcomes. This study prospectively determines the agreement between the results of direct testing of antifungal susceptibilities from blood culture bottles by disk diffusion and Etest and the results of standardized susceptibility testing methods; direct testing would allow susceptibility results to be available 1 to 2 days earlier. A total of 104 blood cultures with different Candida species (28% C. albicans, 27% C. parapsilosis, 26% C. tropicalis, etc.) were evaluated between January 2012 and May 2013 for agreement of fluconazole, voriconazole, and amphotericin B susceptibility results by disk diffusion. Agreement in MICs obtained by Etest was determined for fluconazole (21 isolates), voriconazole (28 isolates), amphotericin (29 isolates), and caspofungin (29 isolates). The kappa scores for categorical agreement were highest for fluconazole by disk diffusion (0.902, standard error [SE] = 0.076) and Etest (1.00, SE = 0.218) and for amphotericin B by disk diffusion (1.00, SE = 0.098). The Pearson correlation (r) of zone diameters was strongest for fluconazole (0.69) and amphotericin (0.70) and moderate for voriconazole (0.60), and the Pearson correlation of MICs was strongest for fluconazole (0.94) and caspofungin (0.88). However, the moderate correlation of amphotericin MICs with zone diameters (-0.42) precludes the use of amphotericin B disk diffusion for susceptibility testing. There were no very major errors; however, there were 1 (1%) major and 5 (4.8%) minor errors with disk diffusion and 4 (13.3%) minor errors with Etest. Thus, antifungal disk diffusion directly from blood culture bottles is a rapid and easy method for fluconazole and voriconazole susceptibility testing for timely tailoring of candidemia therapy.

  12. Prevalence, Distribution, and Antifungal Susceptibility Profiles of Candida parapsilosis, C. orthopsilosis, and C. metapsilosis in a Tertiary Care Hospital▿

    PubMed Central

    Silva, Ana P.; Miranda, Isabel M.; Lisboa, Carmen; Pina-Vaz, Cidália; Rodrigues, Acácio G.

    2009-01-01

    Candida parapsilosis, an emergent agent of nosocomial infections, was previously made up of a complex of three genetically distinct groups (groups I, II, and III). Recently, the C. parapsilosis groups have been renamed as distinct species: C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis. In Portugal, no data pertaining to the distribution and antifungal susceptibility of these Candida species are yet available. In the present report, we describe the incidence and distribution of C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis among 175 clinical and environmental isolates previously identified by conventional methods as C. parapsilosis. We also evaluated the in vitro susceptibilities of the isolates to fluconazole, voriconazole, posaconazole, amphotericin B, and two echinocandins, caspofungin and anidulafungin. Of the 175 isolates tested, 160 (91.4%) were identified as C. parapsilosis sensu stricto, 4 (2.3%) were identified as C. orthopsilosis, and 5 (2.9%) were identified as C. metapsilosis. Six isolates corresponded to species other than the C. parapsilosis group. Interestingly, all isolates from blood cultures corresponded to C. parapsilosis sensu stricto. Evaluation of the antifungal susceptibility profile showed that only nine (5.6%) C. parapsilosis sensu stricto strains were susceptible-dose dependent or resistant to fluconazole, and a single strain displayed a multiazole-resistant phenotype; two (1.3%) C. parapsilosis sensu stricto strains were amphotericin B resistant. All C. orthopsilosis and C. metapsilosis isolates were susceptible to azoles and amphotericin B. A high number of strains were nonsusceptible to the echinocandins (caspofungin and anidulafungin). PMID:19494078

  13. Candida haemulonii and closely related species at 5 university hospitals in Korea: identification, antifungal susceptibility, and clinical features.

    PubMed

    Kim, Mi-Na; Shin, Jong Hee; Sung, Heungsup; Lee, Kyungwon; Kim, Eui-Chong; Ryoo, Namhee; Lee, Jin-Sol; Jung, Sook-In; Park, Kyung Hwa; Kee, Seung Jung; Kim, Soo Hyun; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook

    2009-03-15

    Background. Candida haemulonii, a yeast species that often exhibits antifungal resistance, rarely causes human infection. During 2004-2006, unusual yeast isolates with phenotypic similarity to C. haemulonii were recovered from 23 patients (8 patients with fungemia and 15 patients with chronic otitis media) in 5 hospitals in Korea. Methods. Isolates were characterized using D1/D2 domain and ITS gene sequencing, and the susceptibility of the isolates to 6 antifungal agents was tested in vitro. Results. Gene sequencing of the blood isolates confirmed C. haemulonii group I (in 1 patient) and Candida pseudohaemulonii (in 7 patients), whereas all isolates recovered from the ear were a novel species of which C. haemulonii is its closest relative. The minimum inhibitory concentration (MIC) ranges of amphotericin B, fluconazole, itraconazole, and voriconazole for all isolates were 0.5-32 microg/mL (MIC(50), 1 microg/mL), 2-128 microg/mL (MIC(50), 4 microg/mL), 0.125-4 microg/mL (MIC(50), 0.25 microg/mL), and 0.03-2 microg/mL (MIC(50), 0.06 microg/mL), respectively. All isolates were susceptible to caspofungin (MIC, 0.125-0.25 microg/mL) and micafungin (MIC, 0.03-0.06 microg/mL). All cases of fungemia occurred in patients with severe underlying diseases who had central venous catheters. Three patients developed breakthrough fungemia while receiving antifungal therapy, and amphotericin B therapeutic failure, which was associated with a high MIC of amphotericin B (32 microg/mL), was observed in 2 patients. Conclusions. Candida species that are closely related to C. haemulonii are emerging sources of infection in Korea. These species show variable patterns of susceptibility to amphotericin B and azole antifungal agents.

  14. Resistance Surveillance in Candida albicans: A Five-Year Antifungal Susceptibility Evaluation in a Brazilian University Hospital

    PubMed Central

    Peron, Isabela Haddad; Reichert-Lima, Franqueline; Busso-Lopes, Ariane Fidelis; Nagasako, Cristiane Kibune; Lyra, Luzia; Moretti, Maria Luiza

    2016-01-01

    Candida albicans caused 44% of the overall candidemia episodes from 2006 to 2010 in our university tertiary care hospital. As different antifungal agents are used in therapy and also immunocompromised patients receive fluconazole prophylaxis in our institution, this study aimed to perform an antifungal susceptibility surveillance with the C.albicans bloodstream isolates and to characterize the fluconazole resistance in 2 non-blood C.albicans isolates by sequencing ERG11 gene. The study included 147 C. albicans bloodstream samples and 2 fluconazole resistant isolates: one from oral cavity (LIF 12560 fluconazole MIC: 8μg/mL) and one from esophageal cavity (LIF-E10 fluconazole MIC: 64μg/mL) of two different patients previously treated with oral fluconazole. The in vitro antifungal susceptibility to amphotericin B (AMB), 5-flucytosine (5FC), fluconazole (FLC), itraconazole (ITC), voriconazole (VRC), caspofungin (CASP) was performed by broth microdilution methodology recommended by the Clinical and Laboratory Standards Institute documents (M27-A3 and M27-S4, CLSI). All blood isolates were classified as susceptible according to CLSI guidelines for all evaluated antifungal agents (MIC range: 0,125–1.00 μg/mL for AMB, ≤0.125–1.00 μg/mL for 5FC, ≤0.125–0.5 μg/mL for FLC, ≤0.015–0.125 μg/mL for ITC, ≤0.015–0.06 μg/mL for VRC and ≤0.015–0.125 μg/mL for CASP). In this study, we also amplified and sequenced the ERG11 gene of LIF 12560 and LIF-E10 C.albicans isolates. Six mutations encoding distinct amino acid substitutions were found (E116D, T128K, E266D, A298V, G448V and G464S) and these mutations were previously described as associated with fluconazole resistance. Despite the large consumption of antifungals in our institution, resistant blood isolates were not found over the trial period. Further studies should be conducted, but it may be that the very prolonged direct contact with the oral antifungal agent administered to the patient from which

  15. Geographic and Temporal Trends in Isolation and Antifungal Susceptibility of Candida parapsilosis: a Global Assessment from the ARTEMIS DISK Antifungal Surveillance Program, 2001 to 2005▿

    PubMed Central

    Pfaller, M. A.; Diekema, D. J.; Gibbs, D. L.; Newell, V. A.; Ng, K. P.; Colombo, A.; Finquelievich, J.; Barnes, R.; Wadula, J.

    2008-01-01

    We examined data from the ARTEMIS DISK Antifungal Surveillance Program to describe geographic and temporal trends in the isolation of Candida parapsilosis from clinical specimens and the in vitro susceptibilities of 9,371 isolates to fluconazole and voriconazole. We also report the in vitro susceptibility of bloodstream infection (BSI) isolates of C. parapsilosis to the echinocandins, anidulafungin, caspofungin, and micafungin. C. parapsilosis represented 6.6% of the 141,383 isolates of Candida collected from 2001 to 2005 and was most common among isolates from North America (14.3%) and Latin America (9.9%). High levels of susceptibility to both fluconazole (90.8 to 95.8%) and voriconazole (95.3 to 98.1%) were observed in all geographic regions with the exception of the Africa and Middle East region (79.3 and 85.8% susceptible to fluconazole and voriconazole, respectively). C. parapsilosis was most often isolated from blood and skin and/or soft tissue specimens and from patients hospitalized in the medical, surgical, intensive care unit (ICU) and dermatology services. Notably, isolates from the surgical ICU were the least susceptible to fluconazole (86.3%). There was no evidence of increasing azole resistance over time among C. parapsilosis isolates tested from 2001 to 2005. Of BSI isolates tested against the three echinocandins, 92, 99, and 100% were inhibited by concentrations of ≤2 μg/ml of anidulafungin (621 isolates tested), caspofungin (1,447 isolates tested), and micafungin (539 isolates tested), respectively. C. parapsilosis is a ubiquitous pathogen that remains susceptible to the azoles and echinocandins; however, both the frequency of isolation and the resistance of C. parapsilosis to fluconazole and voriconazole may vary by geographic region and clinical service. PMID:18199791

  16. Yeast vaginitis during pregnancy: susceptibility testing of 13 antifungal drugs and boric acid and the detection of four virulence factors.

    PubMed

    Kalkanci, Ayşe; Güzel, Ahmet Bariş; Khalil, Israa Ibrahim Jabban; Aydin, Merve; Ilkit, Macit; Kuştimur, Semra

    2012-08-01

    A higher prevalence of vulvovaginal candidiasis (VVC) is seen in pregnant women compared with those who are not pregnant. Recurrence is also more common in pregnant women, and therapeutic responses are reduced. In this investigation, 207 vaginal yeast isolates recovered from pregnant women were tested for susceptibility to 13 antifungal drugs and boric acid and through these studies four virulence factors were also determined. The isolates were recovered from vaginal samples of patients with acute VVC [AVVC, (n = 73)], symptomatic recurrent VVC [RVVC, (n = 89)], asymptomatic RVVC (n = 27), and those without signs and symptoms (n = 18). Candida albicans was the most common species found (59.9%), followed by C. glabrata (19.8%), other Candida spp., (19.8%), and Saccharomyces cerevisiae (0.5%). Antifungal susceptibility testing was performed as described in CLSI document M27-A3. Additionally, we examined phospholipase and proteinase production, adhesion to vaginal epithelial cells and hemolytic activity. Notably, the MIC values of Candida spp. isolates derived from patients with VVC were no different from those of the controls (P > 0.05). In addition, Candida isolates derived from patients with AVVC or RVVC produced significantly higher amounts of phospholipase and proteinase compared with the controls (P < 0.05). Antifungal testing and the determination of virulence factors may lead to the effective and prompt treatment of VVC, particularly in pregnant women.

  17. Candida glabrata susceptibility to antifungals and phagocytosis is modulated by acetate.

    PubMed

    Mota, Sandra; Alves, Rosana; Carneiro, Catarina; Silva, Sónia; Brown, Alistair J; Istel, Fabian; Kuchler, Karl; Sampaio, Paula; Casal, Margarida; Henriques, Mariana; Paiva, Sandra

    2015-01-01

    Candida glabrata is considered a major opportunistic fungal pathogen of humans. The capacity of this yeast species to cause infections is dependent on the ability to grow within the human host environment and to assimilate the carbon sources available. Previous studies have suggested that C. albicans can encounter glucose-poor microenvironments during infection and that the ability to use alternative non-fermentable carbon sources, such as carboxylic acids, contributes to the virulence of this fungus. Transcriptional studies on C. glabrata cells identified a similar response, upon nutrient deprivation. In this work, we aimed at analyzing biofilm formation, antifungal drug resistance, and phagocytosis of C. glabrata cells grown in the presence of acetic acid as an alternative carbon source. C. glabrata planktonic cells grown in media containing acetic acid were more susceptible to fluconazole and were better phagocytosed and killed by macrophages than when compared to media lacking acetic acid. Growth in acetic acid also affected the ability of C. glabrata to form biofilms. The genes ADY2a, ADY2b, FPS1, FPS2, and ATO3, encoding putative carboxylate transporters, were upregulated in C. glabrata planktonic and biofilm cells in the presence of acetic acid. Phagocytosis assays with fps1 and ady2a mutant strains suggested a potential role of FPS1 and ADY2a in the phagocytosis process. These results highlight how acidic pH niches, associated with the presence of acetic acid, can impact in the treatment of C. glabrata infections, in particular in vaginal candidiasis. PMID:26388859

  18. Biofilm formation by and antifungal susceptibility of Candida isolates from urine.

    PubMed

    Jain, N; Kohli, R; Cook, E; Gialanella, P; Chang, T; Fries, B C

    2007-03-01

    Biofilm formation (BF) in the setting of candiduria has not been well studied. We determined BF and MIC to antifungals in Candida spp. isolates grown from urine samples of patients and performed a retrospective chart review to examine the correlation with risk factors. A total of 67 Candida spp. isolates were grown from urine samples from 55 patients. The species distribution was C. albicans (54%), C. glabrata (36%), and C. tropicalis (10%). BF varied greatly among individual Candida isolates but was stable in sequential isolates during chronic infection. BF also depended on the growth medium and especially in C. albicans was significantly enhanced in artificial urine (AU) compared to RPMI medium. In nine of the C. albicans strains BF was 4- to 10-fold higher in AU, whereas in three of the C. albicans strains and two of the C. glabrata strains higher BF was measured in RPMI medium than in AU. Determination of the MICs showed that planktonic cells of all strains were susceptible to amphotericin B (AMB) and caspofungin (CASPO) and that three of the C. glabrata strains and two of the C. albicans strains were resistant to fluconazole (FLU). In contrast, all biofilm-associated adherent cells were resistant to CASPO and FLU. The biofilms of 14 strains (28%) were sensitive to AMB (MIC(50) of <1 mug/ml). Correlation between degree of BF and MIC of AMB was not seen in RPMI grown biofilms but was present when grown in AU. A retrospective chart review demonstrated no correlation of known risk factors of candiduria with BF in AU or RPMI. We conclude that BF is a stable characteristic of Candida strains that varies greatly among clinical strains and is dependent on the growth medium. Resistance to AMB is associated with higher BF in AU, which may represent the more physiologic medium to test BF. Future studies should address whether in vitro BF can predict treatment failure in vivo.

  19. 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

  20. Fungal peritonitis in patients undergoing peritoneal dialysis (PD) in Brazil: molecular identification, biofilm production and antifungal susceptibility of the agents.

    PubMed

    Giacobino, Juliana; Montelli, Augusto Cezar; Barretti, Pasqual; Bruder-Nascimento, Ariane; Caramori, Jacqueline Teixeira; Barbosa, Luciano; Bagagli, Eduardo

    2016-10-01

    This paper presents data on fungal peritonitis (FP) in patients undergoing peritoneal dialysis (PD) at the University Hospital of Botucatu Medical School, São Paulo, Brazil. In a total of 422 patients, 30 developed FP, from which the medical records and the fungal isolates of 23 patient cases were studied. All patients presented abdominal pain, cloudy peritoneal effluent, needed hospitalization, had the catheter removed and were treated with fluconazole or fluconazole plus 5-flucitosine; six of them died due to FP. Concerning the agents, it was observed that Candida parapsilosis was the leading species (9/23), followed by Candida albicans (5/23), Candida orthopsilosis (4/23), Candida tropicalis (3/23), Candida guilliermondii (1/23), and Kodamaea ohmeri (1/23). All the isolates were susceptible to amphotericin B, voriconazole and caspofungin whereas C. albicans isolates were susceptible to all antifungals tested. Resistance to fluconazole was observed in three isolates of C. orthopsilosis, and dose-dependent susceptibility to this antifungal was observed in two isolates of C. parapsilosis and in the K. ohmeri isolate. Biofilm production estimates were high or moderate in most isolates, especially in C. albicans species, and low in C. parapsilosis species, with a marked variation among the isolates. This Brazilian study reinforces that FP in PD is caused by a diverse group of yeasts, most prevalently C. parapsilosis sensu stricto species. In addition, they present significant variation in susceptibility to antifungals and biofilm production, thus contributing to the complexity and severity of the clinical features.

  1. Species level identification and antifungal susceptibility of yeasts isolated from various clinical specimens and evaluation of Integral System Yeasts Plus.

    PubMed

    Bicmen, Can; Doluca, Mine; Gulat, Sinem; Gunduz, Ayriz T; Tuksavul, Fevziye

    2012-07-01

    It is essential to use easy, standard, cost-effective and accurate methods for identification and susceptibility testing of yeasts in routine practice. This study aimed to establish the species distribution and antifungal susceptibility of yeast isolates and also to evaluate the performance of the colorimetric and commercially available Integral System Yeasts Plus (ISYP). Yeast isolates (n=116) were identified by conventional methods and ISYP. Antifungal susceptibility testing was performed by the microdilution method according to the standards of CLSI M27-A3 and ISYP. Candida albicans (50%) was the most common species isolated, followed by C. parapsilosis (25%) (mostly in blood samples). According to the CLSI M27-S3 criteria, resistance rates for amphotericin B, flucytosine, fluconazole, itraconazole, and voriconazole were 0%, 0%, 4.6%, 4.5% and 1.8%, respectively. Resistance for miconazole (MIC >1 mg/L) was found as 17.9%. Sixty-two (53.4%) of the isolates which were analyzed by ISYP showed disagreement with those identified by the conventional methods and API ID 32C identification kit or a specific identification code could not be assigned by ISYP. The performance of ISYP could be indicated as low for all antifungal drugs tested according to the ROC analysis (AUC: 0.28-0.56). As the current version of ISYP displays a poor performance, it is recommended to use the other commercial systems whose results are approved as reliable and in agreement with those of the reference methods in identification and susceptibility testing of yeasts. PMID:22842602

  2. Standardized methods and quality control limits for agar and broth microdilution susceptibility testing of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum.

    PubMed

    Waites, Ken B; Duffy, Lynn B; Bébéar, Cécile M; Matlow, Anne; Talkington, Deborah F; Kenny, George E; Totten, Patricia A; Bade, Donald J; Zheng, Xiaotian; Davidson, Maureen K; Shortridge, Virginia D; Watts, Jeffrey L; Brown, Steven D

    2012-11-01

    An international multilaboratory collaborative study was conducted to develop standard media and consensus methods for the performance and quality control of antimicrobial susceptibility testing of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum using broth microdilution and agar dilution techniques. A reference strain from the American Type Culture Collection was designated for each species, which was to be used for quality control purposes. Repeat testing of replicate samples of each reference strain by participating laboratories utilizing both methods and different lots of media enabled a 3- to 4-dilution MIC range to be established for drugs in several different classes, including tetracyclines, macrolides, ketolides, lincosamides, and fluoroquinolones. This represents the first multilaboratory collaboration to standardize susceptibility testing methods and to designate quality control parameters to ensure accurate and reliable assay results for mycoplasmas and ureaplasmas that infect humans.

  3. Oxacillin susceptibility testing of Staphylococcus saprophyticus using disk diffusion, agar dilution, broth microdilution, and the Vitek GPS-105 card.

    PubMed

    Ramotar, K; Woods, W; Toye, B

    2001-08-01

    Eighty-three mecA negative isolates of S. saprophyticus had oxacillin zone diameters agar dilution, broth microdilution, or the Vitek GPS-105 card. Greater than 90% of these isolates would be considered resistant using NCCLS M7-A5, M100-S10 criteria. These results suggest that the current NCCLS MIC and zone diameter breakpoints for oxacillin resistance in coagulase-negative Staphylococci are not appropriate for S. saprophyticus as they do not correlate with the presence of the mecA gene.

  4. Nectar yeasts of the Metschnikowia clade are highly susceptible to azole antifungals widely used in medicine and agriculture.

    PubMed

    Álvarez-Pérez, Sergio; de Vega, Clara; Pozo, María I; Lenaerts, Marijke; Van Assche, Ado; Herrera, Carlos M; Jacquemyn, Hans; Lievens, Bart

    2016-02-01

    The widespread use of azole antifungals in medicine and agriculture and the resulting long-persistent residues could potentially affect beneficial fungi. However, there is very little information on the tolerance of non-target environmental fungi to azoles. In this study, we assessed the susceptibility of diverse plant- and insect-associated yeasts from the Metschnikowia clade, including several ecologically important species, to widely used medical and agricultural azoles (epoxiconazole, imazalil, ketoconazole and voriconazole). A total of 120 strains from six species were tested. Minimum inhibitory concentrations (MICs) were determined by the EUCAST broth microdilution procedure after some necessary modifications were made. The majority of species tested were highly susceptible to epoxiconazole, ketoconazole and voriconazole (>95% of strains showed MICs ≤ 0.125 mg l(-1)). Most strains were also very susceptible to imazalil, although MIC values were generally higher than for the other azoles. Furthermore, certain Metschnikowia reukaufii strains displayed a 'trailing' phenotype (i.e. showed reduced but persistent growth at antifungal concentrations above the MIC), but this characteristic was dependent on test conditions. It was concluded that exposure to azoles may pose a risk for ecologically relevant yeasts from the Metschnikowia clade, and thus could potentially impinge on the tripartite interaction linking these fungi with plants and their insect pollinators.

  5. Nectar yeasts of the Metschnikowia clade are highly susceptible to azole antifungals widely used in medicine and agriculture.

    PubMed

    Álvarez-Pérez, Sergio; de Vega, Clara; Pozo, María I; Lenaerts, Marijke; Van Assche, Ado; Herrera, Carlos M; Jacquemyn, Hans; Lievens, Bart

    2016-02-01

    The widespread use of azole antifungals in medicine and agriculture and the resulting long-persistent residues could potentially affect beneficial fungi. However, there is very little information on the tolerance of non-target environmental fungi to azoles. In this study, we assessed the susceptibility of diverse plant- and insect-associated yeasts from the Metschnikowia clade, including several ecologically important species, to widely used medical and agricultural azoles (epoxiconazole, imazalil, ketoconazole and voriconazole). A total of 120 strains from six species were tested. Minimum inhibitory concentrations (MICs) were determined by the EUCAST broth microdilution procedure after some necessary modifications were made. The majority of species tested were highly susceptible to epoxiconazole, ketoconazole and voriconazole (>95% of strains showed MICs ≤ 0.125 mg l(-1)). Most strains were also very susceptible to imazalil, although MIC values were generally higher than for the other azoles. Furthermore, certain Metschnikowia reukaufii strains displayed a 'trailing' phenotype (i.e. showed reduced but persistent growth at antifungal concentrations above the MIC), but this characteristic was dependent on test conditions. It was concluded that exposure to azoles may pose a risk for ecologically relevant yeasts from the Metschnikowia clade, and thus could potentially impinge on the tripartite interaction linking these fungi with plants and their insect pollinators. PMID:26703195

  6. Antifungal susceptibility of clinical and environmental isolates of Cryptococcus neoformans to four antifungal drugs determined by two techniques.

    PubMed

    Moraes, E M P; Prímola, N S; Hamdan, Júnia Soares

    2003-06-01

    A total of 64 Cryptococcus neoformans strains, including clinical and environmental Brazilian isolates var. neoformans and var. gattii, were tested for susceptibility to amphotericin B, 5-flucytosine, fluconazole and itraconazole. The tests were performed according to the recommendations of National Committee of Clinical Laboratory Standards and the method of macrodilution in liquid medium of Shadomy et al. [Manual de Microbiologia Clínica, 4th ed. Buenos Aires: Editorial Medica Panamericana, 1987: 1229-38]. For most drugs there was a significant difference between the readings taken at 24 and 48 h with both methods. When the minimum inhibitory concentrations obtained by the two techniques were compared, significant differences were observed for amphotericin B and fluconazole. Overall, differences in drug susceptibility with respect to the origin of the isolates or the variety of the fungus were not observed. As an exception, the gattii variety exhibited a high resistance rate to amphotericin B when the technique of Shadomy et al. was applied, a fact possibly related to the greater difficulty for treatment of the disease caused by this fungal variety.

  7. Collaborative investigation of broth microdilution and semisolid agar dilution for in vitro susceptibility testing of Candida albicans.

    PubMed

    Shawar, R; Paetznick, V; Witte, Z; Ensign, L G; Anaissie, E; LaRocco, M

    1992-08-01

    A study was performed in two laboratories to evaluate the effect of growth medium and test methodology on inter- and intralaboratory variations in the MICs of amphotericin B (AMB), flucytosine (5FC), fluconazole (FLU), itraconazole (ITRA), and the triazole Sch 39304 (SCH) against 14 isolates of Candida albicans. Testing was performed by broth microdilution and semisolid agar dilution with the following media, buffered to pH 7.0 with morpholinepropanesulfonic acid (MOPS): buffered yeast nitrogen base (BYNB), Eagle's minimal essential medium (EMEM), RPMI 1640 medium (RPMI), and synthetic amino acid medium for fungi (SAAMF). Inocula were standardized spectrophotometrically, and endpoints were defined by the complete absence of growth for AMB and by no more than 25% of the growth in the drug-free control for all other agents. Comparative analyses of median MICs, as determined by each test method, were made for all drug-medium combinations. Both methods yielded similar (+/- 1 twofold dilution) median MICs for AMB in EMEM and RPMI, 5FC in all media, and FLU in EMEM, RPMI, and SAAMF. In contrast, substantial between-method variations in median MICs were seen for AMB in BYNB and SAAMF, FLU In BYNB, and ITRA and SCH in all media. Interlaboratory concordance of median MICs was good for AMB, 5FC, and FLU but poor for ITRA and SCH in all media. Endpoint determinations were analyzed by use of kappa statistical analyses for evaluating the strength of observer agreement. Moderate to almost perfect interlaboratory agreement occurred with AMB and 5FC in all media and with FLU in EMEM, RPMI, and SAAMF, irrespective of the test method. Slight to almost perfect interlaboratory agreement occurred with ITRA and SCH in EMEM, RPMI, and SAAMF when tested by semisolid agar dilution but not broth microdilution. Kappa values assessing intralaboratory agreement between methods were high for 5FC in all media, for AMB in BYNB, ENEM, and RPMI, and for FLU in EMEM, RPMI, and SAAMF. One laboratory

  8. Collaborative investigation of broth microdilution and semisolid agar dilution for in vitro susceptibility testing of Candida albicans.

    PubMed Central

    Shawar, R; Paetznick, V; Witte, Z; Ensign, L G; Anaissie, E; LaRocco, M

    1992-01-01

    A study was performed in two laboratories to evaluate the effect of growth medium and test methodology on inter- and intralaboratory variations in the MICs of amphotericin B (AMB), flucytosine (5FC), fluconazole (FLU), itraconazole (ITRA), and the triazole Sch 39304 (SCH) against 14 isolates of Candida albicans. Testing was performed by broth microdilution and semisolid agar dilution with the following media, buffered to pH 7.0 with morpholinepropanesulfonic acid (MOPS): buffered yeast nitrogen base (BYNB), Eagle's minimal essential medium (EMEM), RPMI 1640 medium (RPMI), and synthetic amino acid medium for fungi (SAAMF). Inocula were standardized spectrophotometrically, and endpoints were defined by the complete absence of growth for AMB and by no more than 25% of the growth in the drug-free control for all other agents. Comparative analyses of median MICs, as determined by each test method, were made for all drug-medium combinations. Both methods yielded similar (+/- 1 twofold dilution) median MICs for AMB in EMEM and RPMI, 5FC in all media, and FLU in EMEM, RPMI, and SAAMF. In contrast, substantial between-method variations in median MICs were seen for AMB in BYNB and SAAMF, FLU In BYNB, and ITRA and SCH in all media. Interlaboratory concordance of median MICs was good for AMB, 5FC, and FLU but poor for ITRA and SCH in all media. Endpoint determinations were analyzed by use of kappa statistical analyses for evaluating the strength of observer agreement. Moderate to almost perfect interlaboratory agreement occurred with AMB and 5FC in all media and with FLU in EMEM, RPMI, and SAAMF, irrespective of the test method. Slight to almost perfect interlaboratory agreement occurred with ITRA and SCH in EMEM, RPMI, and SAAMF when tested by semisolid agar dilution but not broth microdilution. Kappa values assessing intralaboratory agreement between methods were high for 5FC in all media, for AMB in BYNB, ENEM, and RPMI, and for FLU in EMEM, RPMI, and SAAMF. One laboratory

  9. Collaborative investigation of broth microdilution and semisolid agar dilution for in vitro susceptibility testing of Candida albicans.

    PubMed

    Shawar, R; Paetznick, V; Witte, Z; Ensign, L G; Anaissie, E; LaRocco, M

    1992-08-01

    A study was performed in two laboratories to evaluate the effect of growth medium and test methodology on inter- and intralaboratory variations in the MICs of amphotericin B (AMB), flucytosine (5FC), fluconazole (FLU), itraconazole (ITRA), and the triazole Sch 39304 (SCH) against 14 isolates of Candida albicans. Testing was performed by broth microdilution and semisolid agar dilution with the following media, buffered to pH 7.0 with morpholinepropanesulfonic acid (MOPS): buffered yeast nitrogen base (BYNB), Eagle's minimal essential medium (EMEM), RPMI 1640 medium (RPMI), and synthetic amino acid medium for fungi (SAAMF). Inocula were standardized spectrophotometrically, and endpoints were defined by the complete absence of growth for AMB and by no more than 25% of the growth in the drug-free control for all other agents. Comparative analyses of median MICs, as determined by each test method, were made for all drug-medium combinations. Both methods yielded similar (+/- 1 twofold dilution) median MICs for AMB in EMEM and RPMI, 5FC in all media, and FLU in EMEM, RPMI, and SAAMF. In contrast, substantial between-method variations in median MICs were seen for AMB in BYNB and SAAMF, FLU In BYNB, and ITRA and SCH in all media. Interlaboratory concordance of median MICs was good for AMB, 5FC, and FLU but poor for ITRA and SCH in all media. Endpoint determinations were analyzed by use of kappa statistical analyses for evaluating the strength of observer agreement. Moderate to almost perfect interlaboratory agreement occurred with AMB and 5FC in all media and with FLU in EMEM, RPMI, and SAAMF, irrespective of the test method. Slight to almost perfect interlaboratory agreement occurred with ITRA and SCH in EMEM, RPMI, and SAAMF when tested by semisolid agar dilution but not broth microdilution. Kappa values assessing intralaboratory agreement between methods were high for 5FC in all media, for AMB in BYNB, ENEM, and RPMI, and for FLU in EMEM, RPMI, and SAAMF. One laboratory

  10. Epidemiology and Antifungal Susceptibility of Bloodstream Fungal Isolates in Pediatric Patients: a Spanish Multicenter Prospective Survey ▿

    PubMed Central

    Pemán, Javier; Cantón, Emilia; Linares-Sicilia, María José; Roselló, Eva María; Borrell, Nuria; Ruiz-Pérez-de-Pipaon, María Teresa; Guinea, Jesús; García, Julio; Porras, Aurelio; García-Tapia, Ana María; Pérez-del-Molino, Luisa; Suárez, Anabel; Alcoba, Julia; García-García, Inmaculada

    2011-01-01

    Data on fungemia epidemiology and antifungal susceptibility of isolates from children are scarce, leading frequently to pediatric empirical treatment based on available adult data. The present study was designed to update the epidemiological, mycological, and in vitro susceptibility data on fungal isolates from children with fungemia in Spain. All fungemia episodes were identified prospectively by blood culture over 13 months at 30 hospitals. Tests of susceptibility to amphotericin B, flucytosine, fluconazole, itraconazole, posaconazole, voriconazole, anidulafungin, caspofungin, and micafungin were performed at participant institutions by a microdilution colorimetric method. New species-specific clinical breakpoints for fluconazole, voriconazole, and echinocandins were also applied. A total of 203 episodes of fungemia in 200 children were identified. A higher proportion of fungal isolates was from general wards than intensive care units (ICU). Candida parapsilosis (46.8%), Candida albicans (36.5%), Candida tropicalis (5.9%), Candida glabrata (3.9%), and Candida guilliermondii (2.5%) were the leading species. C. parapsilosis was the predominant species except in neonates. C. albicans was the most frequent in neonatal ICU settings (51.9%). Intravascular catheter (79.3%), surgery (35%), prematurity (30%), and neutropenia (11%) were the most frequent predisposing factors. Most Candida isolates (95.1%) were susceptible to all antifungals. When the new species-specific clinical breakpoints were applied, all C. parapsilosis isolates were susceptible to echinocandins except one, which was micafungin resistant. This is the largest published series of fungemia episodes in the pediatric setting. C. parapsilosis is the most prevalent species in Spain, followed by C. albicans and C. tropicalis. Resistance to azole and echinocandin agents is extremely rare among Candida species. The fluconazole resistance rate in Spain has decreased in the last 10 years. PMID:22012014

  11. In Vitro Susceptibilities of Clinical Yeast Isolates to the New Antifungal Eberconazole Compared with Their Susceptibilities to Clotrimazole and Ketoconazole

    PubMed Central

    Torres-Rodríguez, Josep M.; Mendez, Raúl; López-Jodra, Olga; Morera, Yolanda; Espasa, Mateu; Jimenez, Teresa; Lagunas, Carme

    1999-01-01

    The antifungal activity of eberconazole, a new imidazole derivative, against 124 clinical isolates of Candida comprising eight different species and to 34 isolates of Cryptococcus neoformans was compared to those of clotrimazole and ketoconazole. MICs of eberconazole, determined by the National Committee for Clinical Laboratory Standards standardized microbroth method, were equal to or lower than those of other azoles, especially for Candida krusei and Candida glabrata, which are usually resistant to triazoles. PMID:10223946

  12. The clinical spectrum of Exophiala jeanselmei, with a case report and in vitro antifungal susceptibility of the species.

    PubMed

    Badali, H; Najafzadeh, M J; van Esbroeck, M; van den Enden, E; Tarazooie, B; Meis, J F G M; de Hoog, G S

    2010-03-01

    Exophiala jeanselmei is clinically redefined as a rare agent of subcutaneous lesions of traumatic origin, eventually causing eumycetoma. Mycetoma is a localized, chronic, suppurative subcutaneous infection of tissue and contiguous bone after a traumatic inoculation of the causative organism. In advanced stages of the infection, one finds tumefaction, abscess formation and draining sinuses. The species has been described as being common in the environment, but molecular methods have only confirmed its occurrence in clinical samples. Current diagnostics of E. jeanselmei is based on sequence data of the Internal Transcribed Spacer (ITS) region of ribosomal DNA (rDNA), which sufficiently reflects the taxonomy of this group. The first purpose of this study was the re-identification of all clinical (n=11) and environmental strains (n=6) maintained under the name E. jeanselmei, and to establish clinical preference of the species in its restricted sense. Given the high incidence of eumycetoma in endemic areas, the second goal of this investigation was the evaluation of in vitro susceptibility of E.jeanselmei to eight conventional and new generations of antifungal drugs to improve antifungal therapy in patients. As an example, we describe a case of black grain mycetoma in a 43-year-old Thai male with several draining sinuses involving the left foot. The disease required extensive surgical excision coupled with intense antifungal chemotherapy to achieve cure. In vitro studies demonstrated that posaconazole and itraconazole had the highest antifungal activity against E. jeanselmei and E. oligosperma for which high MICs were found for caspofungin. However, their clinical effectiveness in the treatment of Exophiala infections remains to be determined. PMID:19642051

  13. Antifungal Susceptibility and Phylogeny of Opportunistic Members of the Genus Fusarium Causing Human Keratomycosis in South India.

    PubMed

    Hassan, Anamangadan Shafeeq; Al-Hatmi, Abdullah M S; Shobana, Coimbatore Subramanian; van Diepeningen, Anne D; Kredics, László; Vágvölgyi, Csaba; Homa, Mónika; Meis, Jacques F; de Hoog, G Sybren; Narendran, Venkatapathy; Manikandan, Palanisamy

    2016-03-01

    Fusarium species are reported frequently as the most common causative agents of fungal keratitis in tropical countries such as India. Sixty-five fusaria isolated from patients were subjected to multilocus DNA sequencing to characterize the spectrum of the species associated with keratitis infections in India. Susceptibilities of these fusaria to ten antifungals were determined in vitro by the broth microdilution method. An impressive phylogenetic diversity of fusaria was reflected in susceptibilities differing at species level. Typing results revealed that the isolates were distributed among species in the species complexes (SCs) of F. solani (FSSC; n = 54), F. oxysporum (FOSC; n = 1), F. fujikuroi (FFSC; n = 3), and F. dimerum (FDSC; n = 7). Amphotericin B, voriconazole, and clotrimazole proved to be the most effective drugs, followed by econazole.

  14. Antifungal susceptibility and molecular typing of 115 Candida albicans isolates obtained from vulvovaginal candidiasis patients in 3 Shanghai maternity hospitals.

    PubMed

    Ying, Chunmei; Zhang, Hongju; Tang, Zhenhua; Chen, Huifen; Gao, Jing; Yue, Chaoyan

    2016-05-01

    In our multicenter study, we studied the distribution of Candida species in vulvovaginal candidiasis patients and investigated antifungal susceptibility profile and genotype of Candida albicans in vaginal swab. A total of 115 Candida albicans strains were detected in 135 clinical isolates. Minimum inhibitory concentration determinations showed that 83% and 81% of the 115 Candida albicans strains were susceptible to fluconazole and voriconazole. Randomly amplified polymorphic DNA analysis (RAPD) was applied to identify clonally related isolates from different patients at the local level. All tested strains were classified into genotype A (77.4%), genotype B (18.3%), and genotype C (4.3%). Genotype A was further classified into five subtypes and genotype B into two subtypes.Candida albicans was the dominant pathogen of vulvovaginal candidiasis, the majority belonging to genotype A in this study. Exposure to azoles is a risk factor for the emergence of azole resistance among Candida albicans isolated from VVC patients.

  15. Validation of the Use of Middlebrook 7H10 Agar, BACTEC MGIT 960, and BACTEC 460 12B Media for Testing the Susceptibility of Mycobacterium tuberculosis to Levofloxacin

    PubMed Central

    Sanders, Cynthia A.; Nieda, Rachel R.; Desmond, Edward P.

    2004-01-01

    Levofloxacin, the active l-isomer of the quinolone ofloxacin, is now widely accepted for treatment of multidrug-resistant tuberculosis. Because the drug is now widely used, we sought to establish susceptibility test conditions for Mycobacterium tuberculosis against levofloxacin by the traditional reference method, agar proportion (AP), the commonly used BACTEC 460 radiometric system, and the newer BACTEC MGIT 960 method. To determine the stability of levofloxacin in the two newer test systems (BACTEC 460 and BACTEC MGIT 960), media containing subinhibitory levels of levofloxacin were prepared and stored at 4 and 37°C for 14 days. The stored media were inoculated with H37Rv, and the drug activity was compared to freshly prepared media. Results show that levofloxacin is stable over the course of testing. Next, optimum levofloxacin test concentrations were determined for AP, BACTEC 460, and BACTEC MGIT 960 methods. MICs were determined for 32 pan-susceptible isolates of M. tuberculosis obtained from presumably untreated patients and 14 quinolone-resistant isolates. The levofloxacin-resistant strains either were isolated from patients who remained culture-positive despite treatment with a quinolone agent (six strains) or contained known mutations in gyrA (eight strains). Levofloxacin MICs resulted in a bimodal pattern with values for resistant strains consistently higher than those for pan-susceptible strains. Results show that levofloxacin concentrations of 2 μg/ml (BACTEC 460 and BACTEC MGIT 960) and 1 μg/ml (AP) inhibited the growth of all pan-susceptible strains while permitting the growth of all levofloxacin-resistant strains. Confirmatory tests with a subset of pan-susceptible and levofloxacin-resistant isolates validated the selected test concentrations. PMID:15528718

  16. Reduced turn-around time for Mycobacterium tuberculosis drug susceptibility testing with a proportional agar microplate assay.

    PubMed

    Nguyen, V A T; Nguyen, H Q; Vu, T T; Nguyen, N A T; Duong, C M; Tran, T H T; Nguyen, H V; Dang, D A; Bañuls, A-L

    2015-12-01

    Multidrug-resistant tuberculosis is a major issue worldwide; however, accessibility to drug susceptibility testing (DST) is still limited in developing countries, owing to high costs and complexity. We developed a proportion method on 12-well microplates for DST. The assay reduced the time to results to <12 days and <10 days when bacterial growth was checked with the naked eye or a microscope, respectively. Comparison with the Canetti-Grosset method showed that the results of the two assays almost overlapped (kappa index 0.98 (95% CI 0.91-1.00) for isoniazid, rifampicin, streptomycin; and kappa index 0.92 (95% CI 0.85-0.99) for ethambutol). The sequencing of genes involved in drug resistance showed similar level of phenotype-genotype agreement between techniques. Finally, measurement of the MICs of rifampicin and ethambutol suggests that the currently used critical ethambutol concentration should be revised, and that the current molecular drug susceptibility tests for rifampicin need to be re-evaluated, as in vitro rifampicin-sensitive isolates could harbour drug resistance-associated mutation(s). PMID:26348263

  17. Candida guilliermondii, an Opportunistic Fungal Pathogen with Decreased Susceptibility to Fluconazole: Geographic and Temporal Trends from the ARTEMIS DISK Antifungal Surveillance Program

    PubMed Central

    Pfaller, M. A.; Diekema, D. J.; Mendez, M.; Kibbler, C.; Erzsebet, P.; Chang, S.-C.; Gibbs, D. L.; Newell, V. A.

    2006-01-01

    Although a rare cause of invasive candidiasis, Candida guilliermondii has been reported to exhibit decreased susceptibility to antifungal agents. Aside from case reports and small surveys, there is little information regarding the epidemiology and antifungal susceptibility profile of C. guilliermondii. We report geographic and temporal trends in the isolation and antifungal susceptibilities of 1,029 C. guilliermondii clinical isolates collected from 127 medical centers as part of the ARTEMIS DISK Antifungal Surveillance Program. In addition, we report the in vitro susceptibility of 132 bloodstream isolates of C. guilliermondii to caspofungin. C. guilliermondii represented 1.4% of the 75,761 isolates collected from 2001 to 2003 and was most common among isolates from Latin America (3.7% versus 0.6 to 1.1%). Decreased susceptibility to fluconazole was noted (75% susceptible; range, 68 to 77% across regions), and voriconazole was more active in vitro against C. guilliermondii than fluconazole (91% susceptible; range, 88 to 93% across regions). Fluconazole was least active against isolates from dermatology (58%) and surgical (69%) services and against isolates associated with skin and soft tissue infection (68%, compared to 85% susceptible for bloodstream isolates). There was no evidence of increasing azole resistance over time among C. guilliermondii isolates tested from 2001 to 2003. Of 132 bloodstream isolates of C. guilliermondii tested against caspofungin, most were inhibited by ≤2 μg/ml (96%; MIC50/MIC90, 0.5/1.0 μg/ml). C. guilliermondii, a species that exhibits reduced susceptibility to fluconazole, is the sixth most frequently isolated Candida species from this large survey and may be an emerging pathogen in Latin America. PMID:17021081

  18. Candida parapsilosis (sensu lato) isolated from hospitals located in the Southeast of Brazil: Species distribution, antifungal susceptibility and virulence attributes.

    PubMed

    Ziccardi, Mariangela; Souza, Lucieri O P; Gandra, Rafael M; Galdino, Anna Clara M; Baptista, Andréa R S; Nunes, Ana Paula F; Ribeiro, Mariceli A; Branquinha, Marta H; Santos, André L S

    2015-12-01

    Candida parapsilosis (sensu lato), which represents a fungal complex composed of three genetically related species - Candida parapsilosis sensu stricto, Candida orthopsilosis and Candida metapsilosis, has emerged as an important yeast causing fungemia worldwide. The goal of the present work was to assess the prevalence, antifungal susceptibility and production of virulence traits in 53 clinical isolates previously identified as C. parapsilosis (sensu lato) obtained from hospitals located in the Southeast of Brazil. Species forming this fungal complex are physiologically/morphologically indistinguishable; however, polymerase chain reaction followed by restriction fragment length polymorphism of FKS1 gene has solved the identification inaccuracy, revealing that 43 (81.1%) isolates were identified as C. parapsilosis sensu stricto and 10 (18.9%) as C. orthopsilosis. No C. metapsilosis was found. The geographic distribution of these Candida species was uniform among the studied Brazilian States (São Paulo, Rio de Janeiro and Espírito Santo). All C. orthopsilosis and almost all C. parapsilosis sensu stricto (95.3%) isolates were susceptible to amphotericin B, fluconazole, itraconazole, voriconazole and caspofungin. Nevertheless, one C. parapsilosis sensu stricto isolate was resistant to fluconazole and another one was resistant to caspofungin. C. parapsilosis sensu stricto isolates exhibited higher MIC mean values to amphotericin B, fluconazole and caspofungin than those of C. orthopsilosis, while C. orthopsilosis isolates displayed higher MIC mean to itraconazole compared to C. parapsilosis sensu stricto. Identical MIC mean values to voriconazole were measured for these Candida species. All the isolates of both species were able to form biofilm on polystyrene surface. Impressively, biofilm-growing cells of C. parapsilosis sensu stricto and C. orthopsilosis exhibited a considerable resistance to all antifungal agents tested. Pseudohyphae were observed in 67.4% and 80

  19. EUCAST technical note on isavuconazole breakpoints for Aspergillus, itraconazole breakpoints for Candida and updates for the antifungal susceptibility testing method documents.

    PubMed

    Arendrup, M C; Meletiadis, J; Mouton, J W; Guinea, J; Cuenca-Estrella, M; Lagrou, K; Howard, S J

    2016-06-01

    The Subcommittee on Antifungal Susceptibility Testing (AFST) of the ESCMID European Committee for Antimicrobial Susceptibility Testing (EUCAST) has determined breakpoints for isavuconazole and Aspergillus and for itraconazole and Candida spp., released a new document summarizing existing and new minimum inhibitory concentration ranges for quality control strains and revised the method documents for yeast and mould susceptibility testing. This technical note is based on the EUCAST isavuconazole and itraconazole rationale documents, version 1.0 of the routine and extended internal quality control for antifungal susceptibility testing as recommended by EUCAST, and the E.Def 7.3, E.Def 9.2 and E.Def 9.3 method documents (http://www.eucast.org). PMID:26851656

  20. Antifungal susceptibility of clinical and environmental Cryptococcus neoformans and Cryptococcus gattii isolates in Jabalpur, a city of Madhya Pradesh in Central India

    PubMed Central

    Gutch, Ruchi Sethi; Nawange, Shesh Rao; Singh, Shankar Mohan; Yadu, Ruchika; Tiwari, Aditi; Gumasta, Richa; Kavishwar, Arvind

    2015-01-01

    In this study, we present antifungal susceptibility data of clinical and environmental isolates of Central Indian Cryptococcus neoformans (Serotype A, n = 8 and n = 50 respectively) and Cryptococcus gattii (Serotype B, n = 01 and n = 04 respectively). Susceptibilities to fluconazole, itraconazole and ketoconazole were determined by using NCCLS broth micro-dilution methodology. The total number of resistant strains for fluconazole in case of C. neoformans and C. gattii showed a significant difference by using chi-square test (p < 0.05*), while considering fisher's exact p value was nonsignificant (p > 0.05). However, the total number of resistant strains for itraconazole and ketoconazole was not found statistically significant. A comparison of geometric means of clinical and environmental strains of C. gattii and C. neoformans was not found statistically significant using student ‘t’ test (p value > 0.05 NS). Though less, the antifungal data obtained in this study suggests that primary resistance among environmental and clinical isolates of C. neoformans and C. gattii against tested antifungal was present and C. gattii comparatively was less susceptible than C. neoformans var. grubii isolates to fluconazole than to itraconazole and ketoconazole. A continuous surveillance of antifungal susceptibility of clinical and environmental isolates of C. neoformans and C. gattii is desirable to monitor the emergence of any resistant strains for better management of cryptococcosis patients. PMID:26691471

  1. Oral Candidiasis among Cancer Patients Attending a Tertiary Care Hospital in Chennai, South India: An Evaluation of Clinicomycological Association and Antifungal Susceptibility Pattern.

    PubMed

    Jayachandran, Abirami Lakshmy; Katragadda, Radhika; Thyagarajan, Ravinder; Vajravelu, Leela; Manikesi, Suganthi; Kaliappan, Shanmugam; Jayachandran, Balaji

    2016-01-01

    Oropharyngeal candidiasis is one of the common manifestations seen in cancer patients on cytotoxic therapy and invasion into deeper tissues can occur if not treated promptly. Emergence of antifungal drug resistance is of serious concern owing to the associated morbidity and mortality. The present study aims at evaluation of clinicomycological association and antifungal drug susceptibility among the 180 recruited patients with cancer on chemotherapy and/or radiotherapy with signs or symptoms suggestive of oral candidiasis. Speciation and antifungal susceptibility was done by Microbroth dilution method for fluconazole, Itraconazole, and Amphotericin B as per standard microbiological techniques. Chi-square test was used for statistical analysis (p < 0.05 was considered statistically significant). Candida albicans was the predominant species isolated (94) (58%) followed by Candida tropicalis (34) (20.9%). Fluconazole and Itraconazole showed an overall resistance rate of 14% and 14.8%, respectively. All the isolates were susceptible to Amphotericin B. There was a significant association between the presence of dry mouth and isolation of Candida (p < 0.001). Such clinicomicrobiological associations can help in associating certain symptoms with the isolation of Candida. Species level identification with in vitro antifungal susceptibility pattern is essential to choose the appropriate drug and to predict the outcome of therapy.

  2. Multicenter comparison of the ISO standard 20776-1 and the serial 2-fold dilution procedures to dilute hydrophilic and hydrophobic antifungal agents for susceptibility testing.

    PubMed

    Gomez-Lopez, Alicia; Arendrup, Maiken Cavling; Lass-Floerl, Cornelia; Rodriguez-Tudela, Juan-Luis; Cuenca-Estrella, Manuel

    2010-05-01

    A multicenter study was conducted to assess the accuracy of the ISO standard 20776-1 and the serial 2-fold dilution procedures for antifungal susceptibility testing. Fluconazole trays can be accurately prepared by following ISO and serial dilution schemes. However, itraconazole trays showed a significant lack of reproducibility that was independent of which method was followed.

  3. Oral Candidiasis among Cancer Patients Attending a Tertiary Care Hospital in Chennai, South India: An Evaluation of Clinicomycological Association and Antifungal Susceptibility Pattern

    PubMed Central

    Katragadda, Radhika; Thyagarajan, Ravinder; Vajravelu, Leela; Manikesi, Suganthi; Kaliappan, Shanmugam

    2016-01-01

    Oropharyngeal candidiasis is one of the common manifestations seen in cancer patients on cytotoxic therapy and invasion into deeper tissues can occur if not treated promptly. Emergence of antifungal drug resistance is of serious concern owing to the associated morbidity and mortality. The present study aims at evaluation of clinicomycological association and antifungal drug susceptibility among the 180 recruited patients with cancer on chemotherapy and/or radiotherapy with signs or symptoms suggestive of oral candidiasis. Speciation and antifungal susceptibility was done by Microbroth dilution method for fluconazole, Itraconazole, and Amphotericin B as per standard microbiological techniques. Chi-square test was used for statistical analysis (p < 0.05 was considered statistically significant). Candida albicans was the predominant species isolated (94) (58%) followed by Candida tropicalis (34) (20.9%). Fluconazole and Itraconazole showed an overall resistance rate of 14% and 14.8%, respectively. All the isolates were susceptible to Amphotericin B. There was a significant association between the presence of dry mouth and isolation of Candida (p < 0.001). Such clinicomicrobiological associations can help in associating certain symptoms with the isolation of Candida. Species level identification with in vitro antifungal susceptibility pattern is essential to choose the appropriate drug and to predict the outcome of therapy. PMID:27403171

  4. Comparative evaluation of the VITEK 2, disk diffusion, etest, broth microdilution, and agar dilution susceptibility testing methods for colistin in clinical isolates, including heteroresistant Enterobacter cloacae and Acinetobacter baumannii strains.

    PubMed

    Lo-Ten-Foe, Jerome R; de Smet, Anne Marie G A; Diederen, Bram M W; Kluytmans, Jan A J W; van Keulen, Peter H J

    2007-10-01

    Increasing antibiotic resistance in gram-negative bacteria has recently renewed interest in colistin as a therapeutic option. The increasing use of colistin necessitates the availability of rapid and reliable methods for colistin susceptibility testing. We compared seven methods of colistin susceptibility testing (disk diffusion, agar dilution on Mueller-Hinton [MH] and Isosensitest agar, Etest on MH and Isosensitest agar, broth microdilution, and VITEK 2) on 102 clinical isolates collected from patient materials during a selective digestive decontamination or selective oral decontamination trial in an intensive-care unit. Disk diffusion is an unreliable method to measure susceptibility to colistin. High error rates and low levels of reproducibility were observed in the disk diffusion test. The colistin Etest, agar dilution, and the VITEK 2 showed a high level of agreement with the broth microdilution reference method. Heteroresistance for colistin was observed in six Enterobacter cloacae isolates and in one Acinetobacter baumannii isolate. This is the first report of heteroresistance to colistin in E. cloacae isolates. Resistance to colistin in these isolates seemed to be induced upon exposure to colistin rather than being caused by stable mutations. Heteroresistant isolates could be detected in the broth microdilution, agar dilution, Etest, or disk diffusion test. The VITEK 2 displayed low sensitivity in the detection of heteroresistant subpopulations of E. cloacae. The VITEK 2 colistin susceptibility test can therefore be considered to be a reliable tool to determine susceptibility to colistin in isolates of genera that are known not to exhibit resistant subpopulations. In isolates of genera known to (occasionally) exhibit heteroresistance, an alternative susceptibility testing method capable of detecting heteroresistance should be used.

  5. Optimizing a Candida Biofilm Microtiter Plate Model for Measurement of Antifungal Susceptibility by Tetrazolium Salt Assay▿

    PubMed Central

    Nett, Jeniel E.; Cain, Michael T.; Crawford, Kyler; Andes, David R.

    2011-01-01

    Candida spp. infect medical devices, such as venous and urinary catheters, by adhering to the surface and forming a community of drug-resistant cells surrounded by a matrix. The ability to measure drug activity during this biofilm mode of growth is of interest for the investigation of resistance mechanisms and novel antifungal therapies. The tetrazolium salt (XTT) reduction assay is the test most commonly used to estimate viable biofilm growth and to examine the impact of biofilm therapies. The primary goal of the current experiments was to identify assay variables that affect the XTT assay result in order to improve assay reproducibility, sensitivity, and throughput for the study of antifungal activity. The species used in the current studies included Candida albicans, C. parapsilosis, and C. glabrata. The assay variables that were studied included the impact of culture conditions, the duration of biofilm growth, the timing and frequency of drug administration, the XTT source and concentration, and the duration of XTT incubation. The conditions that impacted the assay readout and altered assay sensitivity included the duration of biofilm growth, the frequency of drug dosing, and the duration of XTT incubation. Several factors were found to reduce time and assay expense, including the elimination of washing steps, the shortening of incubation times, and the use of lower XTT concentrations. A description of assay pitfalls and troubleshooting is included. Recognition of these technical variables should allow investigators to better design reproducible biofilm therapeutic studies. PMID:21227984

  6. 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

  7. Multicenter evaluation of commercial frozen plates for microdilution broth antifungal susceptibility testing of yeasts and comparison of MIC limits recommended in NCCLS M27-A2.

    PubMed

    Makimura, Koichi; Oguri, Toyoko; Mikami, Yuzuru; Kume, Hikaru; Hanazawa, Ryo; Abe, Michiko; Ikeda, Reiko; Shinoda, Takako

    2005-01-01

    A commercial kit, Frozen Plate for Antifungal Susceptibility Testing of Yeasts, Eiken (Eiken Chemical Co., Ltd., Tokyo), was tested in a multi-institute study to evaluate the agreement between interinstitute MICs and National Committee for Clinical Laboratory Standards (NCCLS) M27-A2 recommendation limits of MIC value. The kit was reported as a method equivalent to the standardized guidelines for antifungal susceptibility testing by the Committee for Clinical Laboratory Standards-1994, the Japanese Society for Medical Mycology, and which is widely used in Japan for amphotericin B, flucytosine, fluconazole, miconazole, and itraconazole. The degrees of inter-institute and NCCLS agreements were good to excellent especially with 48-hr incubation for all antifungal agents. However, the percent agreements to NCCLS recommendations against itraconazole were poor. Overall, MIC values obtained using the frozen plate antifungal susceptibility testing kit, with 48-hr incubation, were thought to be reliable and convenient alternatives to the data obtained by the NCCLS M27-A2 reference macrodilution and microdilution method. This kit will allow matching of results between international laboratories. However, the MIC value for itraconazole requires careful interpretation. PMID:15722594

  8. Osmotin, a plant antifungal protein, subverts signal transduction to enhance fungal cell susceptibility.

    PubMed

    Yun, D J; Ibeas, J I; Lee, H; Coca, M A; Narasimhan, M L; Uesono, Y; Hasegawa, P M; Pardo, J M; Bressan, R A

    1998-05-01

    The plant pathogenesis-related protein osmotin is an antifungal cytotoxic agent that causes rapid cell death in the yeast S. cerevisiae. We show here that osmotin uses a signal transduction pathway to weaken defensive cell wall barriers and increase its cytotoxic efficacy. The pathway activated by osmotin includes the regulatory elements of the mating pheromone response STE4, STE18, STE20, STE5, STE11, STE7, FUS3, KSS1, and STE12. Neither the pheromone receptor nor its associated G protein alpha subunit GPA1 are required for osmotin action. However, mutation of SST2, a negative regulator of G alpha proteins, resulted in supersensitivity to osmotin. Phosphorylation of STE7 was rapidly stimulated by osmotin preceding any changes in cell vitality or morphology. These results demonstrate that osmotin subverts target cell signal transduction as part of its mechanism of action. PMID:9660964

  9. Prevalence and antifungal susceptibility of Candida albicans and its related species Candida dubliniensis and Candida africana isolated from vulvovaginal samples in a hospital of Argentina.

    PubMed

    Theill, Laura; Dudiuk, Catiana; Morano, Susana; Gamarra, Soledad; Nardin, María Elena; Méndez, Emilce; Garcia-Effron, Guillermo

    2016-01-01

    Candida africana taxonomical status is controversial. It was proposed as a separate species within the Candida albicans species complex; however, phylogenetic analyses suggested that it is an unusual variety of C. albicans. The prevalence of C. albicans-related species (Candida dubliniensis and C. africana) as vulvovaginal pathogens is not known in Argentina. Moreover, data on antifungal susceptibility of isolates causing vulvovaginal candidiasis is scarce. The aims of this study were to establish the prevalence of C. dubliniensis and C. africana in vaginal samples and to evaluate the antifungal susceptibilities of vaginal C. albicans species complex strains. We used a molecular-based method coupled with a new pooled DNA extraction methodology to differentiate C. dubliniensis and C. africana in a collection of 287 strains originally identified as C. albicans isolated from an Argentinian hospital during 2013. Antifungal susceptibilities to fluconazole, clotrimazole, itraconazole, voriconazole, nystatin, amphotericin B and terbinafine were evaluated by using the CLSI M27-A3 and M27-S4 documents. Of the 287 isolates, 4 C. dubliniensis and one C. africana strains (1.39% and 0.35% prevalence, respectively) were identified. This is the first description of C. africana in Argentina and its identification was confirmed by sequencing the ITS2 region and the hwp1 gene. C. dubliniensis and C. africana strains showed very low MIC values for all the tested antifungals. Fluconazole-reduced-susceptibility and azole cross-resistance were observed in 3.55% and 1.41% of the C. albicans isolates, respectively. These results demonstrate that antifungal resistance is still a rare phenomenon in this kind of isolates.

  10. Prevalence and antifungal susceptibility of Candida albicans and its related species Candida dubliniensis and Candida africana isolated from vulvovaginal samples in a hospital of Argentina.

    PubMed

    Theill, Laura; Dudiuk, Catiana; Morano, Susana; Gamarra, Soledad; Nardin, María Elena; Méndez, Emilce; Garcia-Effron, Guillermo

    2016-01-01

    Candida africana taxonomical status is controversial. It was proposed as a separate species within the Candida albicans species complex; however, phylogenetic analyses suggested that it is an unusual variety of C. albicans. The prevalence of C. albicans-related species (Candida dubliniensis and C. africana) as vulvovaginal pathogens is not known in Argentina. Moreover, data on antifungal susceptibility of isolates causing vulvovaginal candidiasis is scarce. The aims of this study were to establish the prevalence of C. dubliniensis and C. africana in vaginal samples and to evaluate the antifungal susceptibilities of vaginal C. albicans species complex strains. We used a molecular-based method coupled with a new pooled DNA extraction methodology to differentiate C. dubliniensis and C. africana in a collection of 287 strains originally identified as C. albicans isolated from an Argentinian hospital during 2013. Antifungal susceptibilities to fluconazole, clotrimazole, itraconazole, voriconazole, nystatin, amphotericin B and terbinafine were evaluated by using the CLSI M27-A3 and M27-S4 documents. Of the 287 isolates, 4 C. dubliniensis and one C. africana strains (1.39% and 0.35% prevalence, respectively) were identified. This is the first description of C. africana in Argentina and its identification was confirmed by sequencing the ITS2 region and the hwp1 gene. C. dubliniensis and C. africana strains showed very low MIC values for all the tested antifungals. Fluconazole-reduced-susceptibility and azole cross-resistance were observed in 3.55% and 1.41% of the C. albicans isolates, respectively. These results demonstrate that antifungal resistance is still a rare phenomenon in this kind of isolates. PMID:26922471

  11. In vitro susceptibilities of clinical and environmental isolates of Cryptococcus neoformans to five antifungal drugs.

    PubMed Central

    Franzot, S P; Hamdan, J S

    1996-01-01

    A total of 53 Cryptococcus neoformans strains, including clinical and environmental Brazilian isolates, were tested for their susceptibilities to amphotericin B, 5-flucytosine, ketoconazole, fluconazole, and itraconazole. The tests were performed according to the National Committee of Clinical Laboratory Standards recommendations (document M27-P). In general, there was a remarkable homogeneity of results for all strains, and comparable MICs were found for environmental and clinical isolates. This paper represents the first contribution in which susceptibility data for Brazilian C. neoformans isolates are provided. PMID:8851624

  12. Human Immunodefeciency Virus Associated Cryptococcal Meningitis at a Tertiary Care Centre: Diagnostic Tools and Antifungal Susceptibility Testing

    PubMed Central

    Munivenkataswamy, Rashmi; Gopi, Anjana; Usman, Shaik Mohammed; Jagadeesh

    2013-01-01

    Context: Cryptococcal meningitis has emerged as a leading cause of the infectious morbidity and mortality in HIV sero-reactive subjects and it is the second most common cause of the opportunistic neuroinfections in it. As this is a indistinguishable from other causes of meningitis, its early diagnosis is the key to the therapeutic success. Objectives: This study was undertaken to know the incidence of Cryptococcal meningitis in HIV sero–reactive individuals and to assess the role of the microbiological parameters in its specific diagnosis, with a perspective of evaluating the anti–fungal resistance. Material and Methods: A total of 66 CSF samples from suspected cases of meningoencephalitis were subjected to standard microbiological procedures. The Cryptococcal isolates were identified by microscopy, the cultural characteristics, melanin production on Niger Seed agar, urea hydrolysis, the Nitrate assimilation test and by capsular antigen detection by latex agglutination. The Cryptoccal isolates were further biotyped by using Canavanine–Glycine–Bromothymol blue agar. The Minimum Inhibitory Concentrations (MIC) of Amphotericin B and Fluconazole for the isolates were detected. Results: The incidence of Cryptococcal meningitis in our study group was 18.2% (12/66). The Cryptococcal antigen was detected in all the 12 cases, whereas microscopy was positive only in 9 cases and Cryptococcus was isolated by culture in 10 cases. All the isolates were sensitive to Amphotericin B and 90% of the isolates were sensitive to Fluconazole. The CD4counts ranged between 22-138 cells /μl. Conclusion: A high incidence of Cryptococcal meningitis in HIV sero-reactive subjects necessitates the importance of a precise and an early microbiological diagnosis for better management of such subjects. Due to the growing concern of emerging drug resistance, the testing for the anti–fungal susceptibility has to be encouraged in all the cases. PMID:24086857

  13. [Evaluation of the VITEK 2 system (AST-YSO1 cards) for antifungal susceptibility testing against different Candida species].

    PubMed

    Ochiuzzi, María E; Arechavala, Alicia; Guelfand, Liliana; Maldonado, Ivana; Soloaga, Rolando

    2014-01-01

    The aim of this investigation was to evaluate the results of antifungal susceptibility for various Candida species using the Vitek 2 semi-automated system (AST-YSO1 cards, bioMérieux), and to compare them with those obtained by the CLSI (Clinical and Laboratory Standards Institute) broth microdilution reference method (Document M27-A3,2008). The essential agreement (EA) was > 90%, except for Candida glabrata against voriconazole (VCZ); and for Candida krusei against fluconazole (FCZ). The overall categorical agreement (CA) was > 90% when FCZ was evaluated and 89.5% at 24h and 80.7% at 48 h for VCZ. The average time for obtaining results was 15.5h. Minor errors were 7.8% at 24h and 6.1% at 48 h for FCZ, and 10.5% at 24h and 19.3% at 48 h for VCZ. There was only one very major error for FCZ against Candida parapsilosis and no major errors were observed. For amphotericin B, only three isolates showed MICs ≥ 2 μg/ml. The Vitek 2 system detected the MIC value for various Candida species and showed excellent agreement with the reference method proposed by the CLSI.

  14. Conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans: influence of growth conditions and antifungal susceptibility profiles.

    PubMed

    Mello, Thaís Pereira de; Aor, Ana Carolina; Oliveira, Simone Santiago Carvalho de; Branquinha, Marta Helena; Santos, André Luis Souza Dos

    2016-06-27

    In the present study, we have investigated some growth conditions capable of inducing the conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans. Germination in Sabouraud medium (pH 7.0, 37ºC, 5% CO2) showed to be a typically time-dependent event, reaching ~75% in S. minutisporum and > 90% in S. apiospermum, S. aurantiacum and L. prolificans after 4 h. Similar germination rate was observed when conidia were incubated under different media and pHs. Contrarily, temperature and CO2 tension modulated the germination. The isotropic conidial growth (swelling) and germ tube-like projection were evidenced by microscopy and cytometry. Morphometric parameters augmented in a time-dependent fashion, evidencing changes in size and granularity of fungal cells compared with dormant 0 h conidia. In parallel, a clear increase in the mitochondrial activity was measured during the transformation of conidia-into-germinated conidia. Susceptibility profiles to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin varied regarding each morphotype and each fungal species. Overall, the minimal inhibitory concentrations for hyphae were higher than conidia and germinated conidia, except for caspofungin. Collectively, our study add new data about the conidia-into-hyphae transformation in Scedosporium and Lomentospora species, which is a relevant biological process of these molds directly connected to their antifungal resistance and pathogenicity mechanisms. PMID:27355215

  15. 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.

  16. Molecular Characterization of Gβ-Like Protein CpcB Involved in Antifungal Drug Susceptibility and Virulence in A. fumigatus

    PubMed Central

    Cai, Zhendong; Chai, Yanfei; Zhang, Caiyun; Feng, Ruoyun; Sang, Hong; Lu, Ling

    2016-01-01

    Aspergillus fumigatus is an airborne human fungal pathogen that can survive in a wide range of environmental condition. G protein complex transduces external signals from a variety of stimuli outside a cell to its interior effectors in all eukaryotes. Gβ-like CpcB (cross pathway control B) belongs to a WD40 repeat protein family with the conserved G–H and W–D residues. Previous studies have demonstrated that Gβ-like proteins cooperate with related signal transduction proteins to function during many important developmental processes in A. fumigatus. However, the molecular characteristics of Gβ-like CpcB have not yet been identified. In this study, we demonstrated that the G–H residues in WD repeat 1, 2, 3, and the W–D residue in WD repeat 2 of CpcB are required not only to control normal hyphal growth and conidiation but also to affect antifungal drug susceptibility. The enhanced drug resistance might be due to reduced intracellular drug accumulation and altered ergosterol component. Moreover, we find that the first G–H residue of CpcB plays an important role in the virulence of A. fumigatus. To our knowledge, this is the first report for finding the importance of the conserved G–H and W–D residues for a Gβ-like protein in understanding of G protein functions. PMID:26903985

  17. Conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans: influence of growth conditions and antifungal susceptibility profiles

    PubMed Central

    de Mello, Thaís Pereira; Aor, Ana Carolina; de Oliveira, Simone Santiago Carvalho; Branquinha, Marta Helena; dos Santos, André Luis Souza

    2016-01-01

    In the present study, we have investigated some growth conditions capable of inducing the conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans. Germination in Sabouraud medium (pH 7.0, 37ºC, 5% CO2) showed to be a typically time-dependent event, reaching ~75% in S. minutisporum and > 90% in S. apiospermum, S. aurantiacum and L. prolificans after 4 h. Similar germination rate was observed when conidia were incubated under different media and pHs. Contrarily, temperature and CO2 tension modulated the germination. The isotropic conidial growth (swelling) and germ tube-like projection were evidenced by microscopy and cytometry. Morphometric parameters augmented in a time-dependent fashion, evidencing changes in size and granularity of fungal cells compared with dormant 0 h conidia. In parallel, a clear increase in the mitochondrial activity was measured during the transformation of conidia-into-germinated conidia. Susceptibility profiles to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin varied regarding each morphotype and each fungal species. Overall, the minimal inhibitory concentrations for hyphae were higher than conidia and germinated conidia, except for caspofungin. Collectively, our study add new data about the conidia-into-hyphae transformation in Scedosporium and Lomentospora species, which is a relevant biological process of these molds directly connected to their antifungal resistance and pathogenicity mechanisms. PMID:27355215

  18. Use of the VITEK 2 system to identify and test the antifungal susceptibility of clinically relevant yeast species.

    PubMed

    Melhem, M S C; Bertoletti, A; Lucca, H R L; Silva, R B O; Meneghin, F A; Szeszs, M W

    2013-12-01

    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

  19. 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

  20. 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.

  1. 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. PMID:25737146

  2. Studies in Phylogeny, Development of Rapid IdentificationMethods, Antifungal Susceptibility, and Growth Rates of Clinical Strains of Sporothrix schenckii Complex in Japan.

    PubMed

    Suzuki, Rumi; Yikelamu, Alimu; Tanaka, Reiko; Igawa, Ken; Yokozeki, Hiroo; Yaguchi, Takashi

    2016-01-01

    Sporotrichosis is a fungal infection caused by the Sporothrix species, which have distinct virulence profiles and geographic distributions. We performed a phylogenetic study in strains morphologically identified as Sporothrix schenckii from clinical specimens in Japan, which were preserved at the Medical Mycology Research Center, Chiba University. In addition, we examined the in vitro antifungal susceptibility and growth rate to evaluate their physiological features. Three hundred strains were examined using sequence analysis of the partial calmodulin gene, or polymerase chain reaction(PCR)method using newly designed species-specific primers; 291 strains were Sporothrix globosa and 9 strains were S. schenckii sensu stricto (in narrow sense, s. s.). S. globosa strains were further clustered into two subclades, and S. schenckii s. s. strains were divided into three subclades. In 38 strains of S. globosa for which antifungal profiles were determined, 4 strains (11%) showed high minimal inhibitory concentration (MIC) value for itraconazole. All tested strains of S. schenckii s. s. and S. globosa showed low sensitivity for amphotericin B. These antifungals are used for treatment of sporotrichosis when infection is severe. S. schenckii s. s. grew better than S. globosa; wherein S. globosa showed restricted growth at 35℃ and did not grow at 37℃. Our molecular data showed that S. globosa is the main causal agent of sporotrichosis in Japan. It is important to determine the antifungal profiles of each case, in addition to accurate species-level identification, to strategize the therapy for sporotrichosis.

  3. Studies in Phylogeny, Development of Rapid IdentificationMethods, Antifungal Susceptibility, and Growth Rates of Clinical Strains of Sporothrix schenckii Complex in Japan.

    PubMed

    Suzuki, Rumi; Yikelamu, Alimu; Tanaka, Reiko; Igawa, Ken; Yokozeki, Hiroo; Yaguchi, Takashi

    2016-01-01

    Sporotrichosis is a fungal infection caused by the Sporothrix species, which have distinct virulence profiles and geographic distributions. We performed a phylogenetic study in strains morphologically identified as Sporothrix schenckii from clinical specimens in Japan, which were preserved at the Medical Mycology Research Center, Chiba University. In addition, we examined the in vitro antifungal susceptibility and growth rate to evaluate their physiological features. Three hundred strains were examined using sequence analysis of the partial calmodulin gene, or polymerase chain reaction(PCR)method using newly designed species-specific primers; 291 strains were Sporothrix globosa and 9 strains were S. schenckii sensu stricto (in narrow sense, s. s.). S. globosa strains were further clustered into two subclades, and S. schenckii s. s. strains were divided into three subclades. In 38 strains of S. globosa for which antifungal profiles were determined, 4 strains (11%) showed high minimal inhibitory concentration (MIC) value for itraconazole. All tested strains of S. schenckii s. s. and S. globosa showed low sensitivity for amphotericin B. These antifungals are used for treatment of sporotrichosis when infection is severe. S. schenckii s. s. grew better than S. globosa; wherein S. globosa showed restricted growth at 35℃ and did not grow at 37℃. Our molecular data showed that S. globosa is the main causal agent of sporotrichosis in Japan. It is important to determine the antifungal profiles of each case, in addition to accurate species-level identification, to strategize the therapy for sporotrichosis. PMID:27581775

  4. Sporothrix schenckii COMPLEX:SUSCEPTIBILITIES TO COMBINED ANTIFUNGAL AGENTS AND CHARACTERIZATION OF ENZYMATIC PROFILES.

    PubMed

    Oliveira, Daniele Carvalho; de Loreto, Érico Silva; Mario, Débora Alves Nunes; Lopes, Paulo G Markus; Neves, Louise Vignolles; da Rocha, Marta Pires; Santurio, Janio Morais; Alves, Sydney Hartz

    2015-01-01

    Sporothrix schenckii was reclassified as a complex encompassing six cryptic species, which calls for the reassessment of clinical and epidemiological data of these new species. We evaluated the susceptibility of Sporothrix albicans(n = 1) , S. brasiliensis(n = 6) , S. globosa(n = 1), S. mexicana(n = 1) and S. schenckii(n = 36) to terbinafine (TRB) alone and in combination with itraconazole (ITZ), ketoconazole (KTZ), and voriconazole (VRZ) by a checkerboard microdilution method and determined the enzymatic profile of these species with the API-ZYM kit. Most interactions were additive (27.5%, 32.5% and 5%) or indifferent (70%, 50% and 52.5%) for TRB+KTZ, TRB+ITZ and TRB+VRZ, respectively. Antagonisms were observed in 42.5% of isolates for the TRB+VRZ combination. Based on enzymatic profiling, the Sporothrix schenckii strains were categorized into 14 biotypes. Leucine arylamidase (LA) activity was observed only for S. albicans and S. mexicana. The species S. globosa and S. Mexicana were the only species without β-glucosidase (GS) activity. Our results may contribute to a better understanding of virulence and resistance among species of the genus Sporothrix in further studies.

  5. Sporothrix schenckii COMPLEX: SUSCEPTIBILITIES TO COMBINED ANTIFUNGAL AGENTS AND CHARACTERIZATION OF ENZYMATIC PROFILES

    PubMed Central

    OLIVEIRA, Daniele Carvalho; de LORETO, Érico Silva; MARIO, Débora Alves Nunes; LOPES, Paulo G. Markus; NEVES, Louise Vignolles; da ROCHA, Marta Pires; SANTURIO, Janio Morais; ALVES, Sydney Hartz

    2015-01-01

    SUMMARY Sporothrix schenckiiwas reclassified as a complex encompassing six cryptic species, which calls for the reassessment of clinical and epidemiological data of these new species. We evaluated the susceptibility of Sporothrix albicans (n = 1) , S. brasiliensis (n = 6) , S. globosa (n = 1), S. mexicana(n = 1) and S. schenckii(n = 36) to terbinafine (TRB) alone and in combination with itraconazole (ITZ), ketoconazole (KTZ), and voriconazole (VRZ) by a checkerboard microdilution method and determined the enzymatic profile of these species with the API-ZYM kit. Most interactions were additive (27.5%, 32.5% and 5%) or indifferent (70%, 50% and 52.5%) for TRB+KTZ, TRB+ITZ and TRB+VRZ, respectively. Antagonisms were observed in 42.5% of isolates for the TRB+VRZ combination. Based on enzymatic profiling, the Sporothrix schenckii strains were categorized into 14 biotypes. Leucine arylamidase (LA) activity was observed only for S. albicans and S. mexicana. The species S. globosaand S. mexicanawere the only species without β-glucosidase (GS) activity. Our results may contribute to a better understanding of virulence and resistance among species of the genus Sporothrixin further studies. PMID:26422151

  6. [Investigation of the correlation between biofilm forming ability of urinary Candida isolates with the use of urinary catheters and change of antifungal susceptibility in the presence of biofilm].

    PubMed

    Aslan, Hacer; Gülmez, Dolunay

    2016-04-01

    Frequency of Candida species causing urinary tract infections is increasing, and this increase is outstanding in nosocomial urinary tract infections especially in intensive care units. The ability of biofilm formation that is contributed to the virulence of the yeast, plays a role in the pathogenesis of biomaterial-related infections and also constitutes a risk for treatment failure. The aims of this study were to compare biofilm forming abilities of Candida strains isolated from urine cultures of patients with and without urinary catheters, and to investigate the change of antifungal susceptibility in the presence of biofilm. A total of 50 Candida strains isolated from urine cultures of 25 patients with urinary catheters (10 C.tropicalis, 6 C.glabrata, 4 C.albicans, 4 C.parapsilosis, 1 C.krusei) and 25 without urinary catheters (8 C.tropicalis, 6 C.albicans, 4 C.krusei, 3 C.parapsilosis, 2 C.kefyr, 1 C.glabrata, 1 C.lusitaniae) were included in the study. Biofilm forming ability was tested by Congo red agar (CRA) and microplate XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction methods. Fluconazole (FLU) and amphotericin B (AMP-B) susceptibilities of the isolates were determined by reference microdilution method recommended by Clinical and Laboratory Standards Institute for planktonic cells and by XTT reduction assay in case of biofilm presence. Biofilm formation was detected in 12 (24%) by CRA and 50 (100%) of the isolates by XTT reduction method. None of the C.albicans (n= 10) and C.tropicalis (n= 18) strains were detected as biofilm positive by CRA, however, these strains were strongly positive by XTT reduction method. No statistically significant correlation was detected between the presence of urinary catheter and biofilm forming ability of the isolate (p> 0.05). This might be caused by the advantage of biofilm forming strains in adhesion to bladder mucosa at the initial stages of infection. For all of the isolates in

  7. [Investigation of the correlation between biofilm forming ability of urinary Candida isolates with the use of urinary catheters and change of antifungal susceptibility in the presence of biofilm].

    PubMed

    Aslan, Hacer; Gülmez, Dolunay

    2016-04-01

    Frequency of Candida species causing urinary tract infections is increasing, and this increase is outstanding in nosocomial urinary tract infections especially in intensive care units. The ability of biofilm formation that is contributed to the virulence of the yeast, plays a role in the pathogenesis of biomaterial-related infections and also constitutes a risk for treatment failure. The aims of this study were to compare biofilm forming abilities of Candida strains isolated from urine cultures of patients with and without urinary catheters, and to investigate the change of antifungal susceptibility in the presence of biofilm. A total of 50 Candida strains isolated from urine cultures of 25 patients with urinary catheters (10 C.tropicalis, 6 C.glabrata, 4 C.albicans, 4 C.parapsilosis, 1 C.krusei) and 25 without urinary catheters (8 C.tropicalis, 6 C.albicans, 4 C.krusei, 3 C.parapsilosis, 2 C.kefyr, 1 C.glabrata, 1 C.lusitaniae) were included in the study. Biofilm forming ability was tested by Congo red agar (CRA) and microplate XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction methods. Fluconazole (FLU) and amphotericin B (AMP-B) susceptibilities of the isolates were determined by reference microdilution method recommended by Clinical and Laboratory Standards Institute for planktonic cells and by XTT reduction assay in case of biofilm presence. Biofilm formation was detected in 12 (24%) by CRA and 50 (100%) of the isolates by XTT reduction method. None of the C.albicans (n= 10) and C.tropicalis (n= 18) strains were detected as biofilm positive by CRA, however, these strains were strongly positive by XTT reduction method. No statistically significant correlation was detected between the presence of urinary catheter and biofilm forming ability of the isolate (p> 0.05). This might be caused by the advantage of biofilm forming strains in adhesion to bladder mucosa at the initial stages of infection. For all of the isolates in

  8. 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. PMID:27527785

  9. Comparative evaluation of macrodilution and alamar colorimetric microdilution broth methods for antifungal susceptibility testing of yeast isolates.

    PubMed Central

    To, W K; Fothergill, A W; Rinaldi, M G

    1995-01-01

    A comparative evaluation of the macrodilution method and the Alamar colorimetric method for the susceptibility testing of amphotericin B, fluconazole, and flucytosine was conducted with 134 pathogenic yeasts. The clinical isolates included 28 Candida albicans, 17 Candida tropicalis, 15 Candida parapsilosis, 12 Candida krusei, 10 Candida lusitaniae, 9 Candida guilliermondii, 18 Torulopsis glabrata, and 25 Cryptococcus neoformans isolates. The macrodilution method was performed and interpreted according to the recommendations of the National Committee for Clinical Laboratory Standards (document M27-P), and the Alamar colorimetric method was performed according to the manufacturer's instructions. For the Alamar colorimetric method, MICs were determined at 24 and 48 h of incubation for Candida species and T. glabrata and at 48 and 72 h of incubation for C. neoformans. The overall agreement within +/- 1 dilution for Candida species and T. glabrata against the three antifungal agents was generally good, with the values for amphotericin B, fluconazole, and flucytosine being 85.3, 77.9, and 86.2%, respectively, at the 24-h readings and 69.3, 65.2, and 97.2%, respectively, at the 48-h readings. Most disagreement was noted with fluconazole against C. tropicalis and T. glabrata. Our studies indicate that determination of MICs at 24 h by the Alamar colorimetric method is a valid alternate method for testing amphotericin B, fluconazole, and flucytosine against Candida species but not for testing fluconazole against C. tropicalis and T. glabrata. For flucytosine, much better agreement can be demonstrated against Candida species and T. glabrata at the 48-h readings by the Alamar method.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8567901

  10. 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. PMID:27061834

  11. Antifungal Susceptibility Profiles of Bloodstream Yeast Isolates by Sensititre YeastOne over Nine Years at a Large Italian Teaching Hospital

    PubMed Central

    Posteraro, Brunella; Spanu, Teresa; Fiori, Barbara; De Maio, Flavio; De Carolis, Elena; Giaquinto, Alessia; Prete, Valentina; De Angelis, Giulia; Torelli, Riccardo; D'Inzeo, Tiziana; Vella, Antonietta; De Luca, Alessio; Tumbarello, Mario; Ricciardi, Walter

    2015-01-01

    Sensititre YeastOne (SYO) is an affordable alternative to the Clinical and Laboratory Standards Institute (CLSI) reference method for antifungal susceptibility testing. In this study, the MICs of yeast isolates from 1,214 bloodstream infection episodes, generated by SYO during hospital laboratory activity (January 2005 to December 2013), were reanalyzed using current CLSI clinical breakpoints/epidemiological cutoff values to assign susceptibility (or the wild-type [WT] phenotype) to systemic antifungal agents. Excluding Candida albicans (57.4% of all isolates [n = 1,250]), the most predominant species were Candida parapsilosis complex (20.9%), Candida tropicalis (8.2%), Candida glabrata (6.4%), Candida guilliermondii (1.6%), and Candida krusei (1.3%). Among the non-Candida species (1.9%), 7 were Cryptococcus neoformans and 17 were other species, mainly Rhodotorula species. Over 97% of Candida isolates were susceptible (WT phenotype) to amphotericin B and flucytosine. Rates of susceptibility (WT phenotype) to fluconazole, itraconazole, and voriconazole were 98.7% in C. albicans, 92.3% in the C. parapsilosis complex, 96.1% in C. tropicalis, 92.5% in C. glabrata, 100% in C. guilliermondii, and 100% (excluding fluconazole) in C. krusei. The fluconazole-resistant isolates consisted of 6 C. parapsilosis complex isolates, 3 C. glabrata isolates, 2 C. albicans isolates, 2 C. tropicalis isolates, and 1 Candida lusitaniae isolate. Of the non-Candida isolates, 2 C. neoformans isolates had the non-WT phenotype for susceptibility to fluconazole, whereas Rhodotorula isolates had elevated azole MICs. Overall, 99.7% to 99.8% of Candida isolates were susceptible (WT phenotype) to echinocandins, but 3 isolates were nonsusceptible (either intermediate or resistant) to caspofungin (C. albicans, C. guilliermondii, and C. krusei), anidulafungin (C. albicans and C. guilliermondii), and micafungin (C. albicans). However, when the intrinsically resistant non-Candida isolates were included

  12. 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. PMID:26333353

  13. Echinocandin and triazole antifungal susceptibility profiles for clinical opportunistic yeast and mold isolates collected from 2010 to 2011: application of new CLSI clinical breakpoints and epidemiological cutoff values for characterization of geographic and temporal trends of antifungal resistance.

    PubMed

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

    2013-08-01

    The SENTRY Antimicrobial Surveillance Program monitors global susceptibility and resistance rates of newer and established antifungal agents. We report the echinocandin and triazole antifungal susceptibility patterns for 3,418 contemporary clinical isolates of yeasts and molds. The isolates were obtained from 98 laboratories in 34 countries during 2010 and 2011. Yeasts not presumptively identified by CHROMagar, the trehalose test, or growth at 42°C and all molds were sequence identified using internal transcribed spacer (ITS) and 28S (yeasts) or ITS, translation elongation factor (TEF), and 28S (molds) genes. Susceptibility testing was performed against 7 antifungals (anidulafungin, caspofungin, micafungin, fluconazole, itraconazole, posaconazole, and voriconazole) using CLSI methods. Rates of resistance to all agents were determined using the new CLSI clinical breakpoints and epidemiological cutoff value criteria, as appropriate. Sequencing of fks hot spots was performed for echinocandin non-wild-type (WT) strains. Isolates included 3,107 from 21 Candida spp., 146 from 9 Aspergillus spp., 84 from Cryptococcus neoformans, 40 from 23 other mold species, and 41 from 9 other yeast species. Among Candida spp., resistance to the echinocandins was low (0.0 to 1.7%). Candida albicans and Candida glabrata that were resistant to anidulafungin, caspofungin, or micafungin were shown to have fks mutations. Resistance to fluconazole was low among the isolates of C. albicans (0.4%), Candida tropicalis (1.3%), and Candida parapsilosis (2.1%); however, 8.8% of C. glabrata isolates were resistant to fluconazole. Among echinocandin-resistant C. glabrata isolates from 2011, 38% were fluconazole resistant. Voriconazole was active against all Candida spp. except C. glabrata (10.5% non-WT), whereas posaconazole showed decreased activity against C. albicans (4.4%) and Candida krusei (15.2% non-WT). All agents except for the echinocandins were active against C. neoformans, and the

  14. Molecular Identification and Antifungal Susceptibility of Yeast Isolates Causing Fungemia Collected in a Population-Based Study in Spain in 2010 and 2011

    PubMed Central

    Guinea, Jesús; Zaragoza, Óscar; Escribano, Pilar; Martín-Mazuelos, Estrella; Pemán, Javier; Sánchez-Reus, Ferrán

    2014-01-01

    We report the molecular identifications and antifungal susceptibilities of the isolates causing fungemia collected in the CANDIPOP population-based study conducted in 29 Spanish hospitals. A total of 781 isolates (from 767 patients, 14 of them having mixed fungemia) were collected. The species found most frequently were Candida albicans (44.6%), Candida parapsilosis (24.5%), Candida glabrata (13.2%), Candida tropicalis (7.6%), Candida krusei (1.9%), Candida guilliermondii (1.7%), and Candida lusitaniae (1.3%). Other Candida and non-Candida species accounted for approximately 5% of the isolates. The presence of cryptic species was low. Compared to findings of previous studies conducted in Spain, the frequency of C. glabrata has increased. Antifungal susceptibility testing was performed by using EUCAST and CLSI M27-A3 reference procedures; the two methods were comparable. The rate of fluconazole-susceptible isolates was 80%, which appears to be a decrease compared to findings of previous studies, explained mainly by the higher frequency of C. glabrata. Using the species-specific breakpoints and epidemiological cutoff values, the rate of voriconazole and posaconazole in vitro resistance was low (<2%). In the case of C. tropicalis, using the EUCAST procedure, the rate of azole resistance was around 20%. There was a correlation between the previous use of azoles and the presence of fluconazole-resistant isolates. Resistance to echinocandins was very rare (2%), and resistance to amphotericin B also was very uncommon. The sequencing of the hot spot (HS) regions from FKS1 or FKS2 genes in echinocandin-resistant isolates revealed previously described point mutations. The decrease in the susceptibility to fluconazole in Spanish isolates should be closely monitored in future studies. PMID:24366741

  15. In Vitro Antifungal Susceptibility and Molecular Characterization of Clinical Isolates of Fusarium verticillioides (F. moniliforme) and Fusarium thapsinum▿

    PubMed Central

    Azor, Mónica; Gené, Josepa; Cano, Josep; Sutton, Deanna A.; Fothergill, Annette W.; Rinaldi, Michael G.; Guarro, Josep

    2008-01-01

    A microdilution method was used to test 11 antifungal drugs against clinical isolates of Fusarium thapsinum and three different phylogenetic clades of Fusarium verticillioides that were characterized by sequencing a region of the β-tubulin gene. Terbinafine was the most-active drug against both species, followed by posaconazole against F. verticillioides. PMID:18391027

  16. Cryptococcus neoformans isolates from Yaoundé human immunodeficiency virus-infected patients exhibited intra-individual genetic diversity and variation in antifungal susceptibility profiles between isolates from the same patient.

    PubMed

    Kammalac Ngouana, Thierry; Drakulovski, Pascal; Krasteva, Donika; Kouanfack, Charles; Reynes, Jacques; Delaporte, Eric; Boyom, Fabrice Fekam; Mallié, Michèle; Bertout, Sebastien

    2016-07-01

    Cryptococcal meningitis is a dreadful opportunistic fungal infection amongst human immunodeficiency virus (HIV)-infected patients. One complication in the management of the disease is the possible infection of a patient by two or more different strains of Cryptococcus neoformans. This study investigated the intra-individual genetic diversity and antifungal susceptibility of C. neoformans isolates from Yaoundé (Cameroon) HIV-infected patients with cryptococcal meningitis. Twenty-five clinical isolates were obtained during a prospective study. Five colonies were randomly collected from each initial sample. The 150 isolates obtained (125 colonies and 25 initial samples) were submitted to serotyping by multiplex PCR. Genotyping analyses were achieved using RFLP, and minisatellite- and microsatellite-length polymorphism. The antifungal susceptibility testing was carried out using a Sensititre YeastOne kit. Seven antifungals were tested: itraconazole, fluconazole, amphotericin B, ketoconazole, 5-fluorocytosine, posaconazole and voriconazole. The 150 isolates were identified as C. neoformans serotype A and genotype VNI. The microsatellite and minisatellite sequence analyses generated 15 genotypes. Six out of 25 (24 %) patients were found to be infected by two different genotypes. Antifungal susceptibility showed several profiles: posaconazole (0.015-0.25 µg ml-1), amphotericin B (0.06-1 µg ml-1), fluconazole (0.5-16 µg ml-1), itraconazole (0.008-0.12 µg ml-1), ketoconazole (0.008-0.12 µg ml-1), 5-fluorocytosine (0.25-16 µg ml-1) and voriconazole (0.008-0.12 µg ml-1). It was noted that isolates from the same patient might present different susceptibility profiles to an antifungal drug with differences of more than four dilutions. The results achieved highlighted the possible presence of isolates with different genotypes in a patient with dissimilar antifungal susceptibility profiles during a single episode of cryptococcal meningitis. PMID:27100672

  17. Point prevalence, microbiology and antifungal susceptibility patterns of oral Candida isolates colonizing or infecting Mexican HIV/AIDS patients and healthy persons.

    PubMed

    Sánchez-Vargas, Luis Octavio; Ortiz-López, Natalia Guadalupe; Villar, María; Moragues, María Dolores; Aguirre, José Manuel; Cashat-Cruz, Miguel; Lopez-Ribot, Jose Luis; Gaitán-Cepeda, Luis Alberto; Quindós, Guillermo

    2005-06-01

    We have conducted a longitudinal study over a 3-year period to address the point prevalence, microbiological characteristics and antifungal susceptibility patterns of yeast isolates colonizing or infecting the oral cavities of 111 HIV-infected (51 adults, 60 children) and 201 non HIV-infected (109 adults, 92 children) Mexican persons. Regarding the epidemiology of oral candidiasis, Candida albicans was the most frequent species isolated. Seventy-one out of 85 isolates from colonized persons were C. albicans (83.5%), 27 isolates of them were from HIV-infected children and 44 from non HIV-infected patients. Sixty-two isolates belonged to serotype A which was the most prevalent serotype of C. albicans. Non-albicans species (Candida glabrata, Candida tropicalis and Candida parapsilosis, and Saccharomyces cerevisiae) were isolated from 16.5% of colonized patients and from 38.5% patients with candidiasis or Candida-related lesions. There were nine episodes of infection or colonization by at least 2 different yeast species. In the case of HIV/AIDS patients, it was determined that yeast carriage was not associated with the number of CD4+ cells or the viral load, but HAART reduced the prevalence of oral candidiasis. Overall, most patients harbored strains in vitro susceptible to fluconazole, however 10.8% of the yeasts were resistant to one or more azole antifungal agents and 29% were intermediate susceptible to them. On the contrary, 5-fluorocytosine was very active against all isolates tested, and amphotericin B was active against 97.9% of them.

  18. The diversity and antifungal susceptibility of the yeasts isolated from coconut water and reconstituted fruit juices in Brazil.

    PubMed

    Maciel, Natália O P; Piló, Fernanda B; Freitas, Larissa F D; Gomes, Fátima C O; Johann, Susana; Nardi, Regina M D; Lachance, Marc-André; Rosa, Carlos A

    2013-01-01

    The aims of this study were to characterise the yeasts present in the reconstituted fruit juices and coconut water extracted with "coconut machines", both collected from commercial outlets in a Brazilian city, and to investigate the antifungal resistance of isolates from these beverages that were able to grow at 37°C. The yeast population counts in the coconut water samples ranged from 1.7 to >6.5logcfu/ml, and in the reconstituted fruit juices, the counts ranged from 1.5 to >5.5logcfu/ml. Aureobasidium pullulans, Candida boidinii, Candidaintermedia, Candidaoleophila, Candidaparapsilosis, Candidasantamariae, Candidatropicalis, Clavispora lusitaniae, Kloeckera apis, Lachancea fermentati, Pichia fermentans and Rhodotorula mucilaginosa were the most frequent species isolated from these beverages. At least 18 yeast species isolated from these beverages have been reported as opportunistic pathogens. Eight yeast isolates were resistant to fluconazole, seven were resistant to itraconazole, and 26 to amphotericin B. Some yeast species were resistant to more than one of the antifungal drugs tested. Two isolates of C. tropicalis from the reconstituted fruit juices exhibited resistance to all three drugs. The presence of yeast strains that are resistant to commonly used antifungal drugs suggests a potential risk, at least to immunocompromised individuals who consume these beverages.

  19. 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

  20. Antifungal polypeptides

    DOEpatents

    Altier, Daniel J.; Ellanskaya, Irina; Ellanskaya, legal representative, Natalia; Gilliam, Jacob T.; Hunter-Cevera, Jennie; Presnail, James K.; Schepers, Eric; Simmons, Carl R.; Torok, Tamas; Yalpani, Nasser

    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.

  1. 21 CFR 582.7115 - Agar-agar.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Agar-agar. 582.7115 Section 582.7115 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7115 Agar-agar. (a) Product. Agar-agar. (b) Conditions of use. This substance is generally recognized as safe when used...

  2. 21 CFR 582.7115 - Agar-agar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Agar-agar. 582.7115 Section 582.7115 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7115 Agar-agar. (a) Product. Agar-agar. (b) Conditions of use. This substance is generally recognized as safe when used...

  3. Diversity and antifungal susceptibility of yeasts isolated by multiple-tube fermentation from three freshwater lakes in Brazil.

    PubMed

    Brandão, Luciana R; Medeiros, Adriana O; Duarte, Mariana C; Barbosa, Anne C; Rosa, Carlos A

    2010-06-01

    The diversity and antifungal resistance of yeasts able to grow at 37 degrees C and the occurrence of bacterial indicators of water quality were studied in three lakes in Southeastern Brazil. The densities of yeasts, Escherichia coli, Enterococcus spp. and Pseudomonas aeruginosa were determined by the multiple-tube fermentation technique, and counts of heterotrophic bacteria were determined using the pour plate method. The yeasts were identified using physiological and molecular techniques and their resistance to amphotericin B, itraconazole and fluconazole was tested. Yeast occurrence was significantly correlated only with the density of fecal coliforms. Candida krusei, C. guilliermondii and C. tropicalis, the most frequently isolated yeast species, are associated with fecal contamination of water by warm-blooded animals. Yeast isolates were most resistant to amphotericin B (21.7%), followed by itraconazole (20%) and then fluconazole (2.8%). In addition to tests for the fecal coliform group, the density of yeasts grown at 37 degrees C could be used as a complementary microbial indicator that aquatic environments contain organic matter of human origin. The incidence of yeast species resistant to three antifungal drugs shows that these microorganisms could pose a health risk to the people who use these lakes for recreation. PMID:20154391

  4. Subculture on potato dextrose agar as a complement to the broth microdilution assay for Malassezia pachydermatis.

    PubMed

    Prado, Marilena R; Brito, Erika H S; Brilhante, Raimunda S N; Cordeiro, Rossana A; Leite, João J G; Sidrim, José J C; Rocha, Marcos F G

    2008-10-01

    The main aim of this study was to verify the efficacy of subculture on potato dextrose agar (PDA) as a complement to the in vitro susceptibility test for Malassezia pachydermatis strains by a broth microdilution method, as well as to determine the MIC and MFC of azole derivatives, amphotericin B and caspofungin. The microdilution assay was performed in 96-well plates using a modified RPMI 1640 medium. The M. pachydermatis strains were resistant to caspofungin. All strains (n=50) had shown MIC values of <0.03, <0.03, 2.0, 4.0 and 4.0 microg/ml for itraconazole, ketoconazole, voriconazole, fluconazole and amphotericin B, respectively. Thus, the subculture on PDA improved the analysis of the in vitro antifungal susceptibility of M. pachydermatis.

  5. Prospective Multicenter Study of the Epidemiology, Molecular Identification, and Antifungal Susceptibility of Candida parapsilosis, Candida orthopsilosis, and Candida metapsilosis Isolated from Patients with Candidemia ▿

    PubMed Central

    Cantón, Emilia; Pemán, Javier; Quindós, Guillermo; Eraso, Elena; Miranda-Zapico, Ilargi; Álvarez, María; Merino, Paloma; Campos-Herrero, Isolina; Marco, Francesc; de la Pedrosa, Elia Gomez G.; Yagüe, Genoveva; Guna, Remedios; Rubio, Carmen; Miranda, Consuelo; Pazos, Carmen; Velasco, David

    2011-01-01

    A 13-month prospective multicenter study including 44 hospitals was carried out to evaluate the epidemiology of Candida parapsilosis complex candidemia in Spain. Susceptibility to amphotericin B, flucytosine, fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, caspofungin, and micafungin was tested by the microdilution colorimetric method. A total of 364 C. parapsilosis complex isolates were identified by molecular methods: C. parapsilosis (90.7%), Candida orthopsilosis (8.2%), and Candida metapsilosis (1.1%). Most candidemias (C. parapsilosis, 76.4%; C. orthopsilosis, 70.0%; C. metapsilosis, 100%) were observed in adults. No C. orthopsilosis or C. metapsilosis candidemias occurred in neonates. C. parapsilosis was most frequent in adult intensive care unit (28.8%), surgery (20.9%), and internal medicine (19.7%) departments; and C. orthopsilosis was most frequent in hematology (28.6%), pediatrics (12.0%), and neonatology (11.5%) departments. The geographic distribution of C. orthopsilosis and C. metapsilosis was not uniform. According to CLSI clinical breakpoints, all C. orthopsilosis and C. metapsilosis isolates were susceptible to the nine agents tested. Resistance (MICs > 1 mg/liter) was observed only in C. parapsilosis: amphotericin B, posaconazole, itraconazole, and caspofungin (0.3% each), anidulafungin (1.9%), and micafungin (2.5%). Applying the new species-specific fluconazole and echinocandin breakpoints, the rates of resistance to fluconazole for C. parapsilosis and C. orthopsilosis increased to 4.8% and 0.3%, respectively; conversely, for C. parapsilosis they shifted from 1.9 to 0.6% (anidulafungin) and from 2.5 to 0.6% (micafungin). Our study confirms the different prevalence of C. parapsilosis complex candidemia among age groups: neither C. orthopsilosis nor C. metapsilosis was isolated from neonates; interestingly, C. metapsilosis was isolated only from adults and the elderly. The disparity in antifungal susceptibility among species

  6. Antifungal agent susceptibilities and interpretation of Malassezia pachydermatis and Candida parapsilosis isolated from dogs with and without seborrheic dermatitis skin.

    PubMed

    Yurayart, Chompoonek; Nuchnoul, Noppawan; Moolkum, Pornsawan; Jirasuksiri, Supitcha; Niyomtham, Waree; Chindamporn, Ariya; Kajiwara, Susumu; Prapasarakul, Nuvee

    2013-10-01

    Malassezia pachydermatis and Candida parapsilosis are recognized as commensal yeasts on the skin of healthy dogs but also causative agents of eborrheic dermatitis, especially in atopic dogs. We determined and compared the susceptibility levels of yeasts isolated from dogs with and without seborrheic dermatitis (SD) using the disk diffusion method (DD) for itraconazole (ITZ), ketoconazole (KTZ), nystatin (NYS), terbinafine (TERB) and 5-fluorocytosine (5-FC) and the broth microdilution method (BMD) for ITZ and KTZ. The reliability between the methods was assessed using an agreement analysis and linear regression. Forty-five M. pachydermatis and 28 C. parapsilosis isolates were identified based on physiological characteristics and an approved molecular analysis. By DD, all tested M. pachydermatis isolates were susceptible to ITZ, KTZ, NYS and TERB but resistant to 5-FC. Only 46 - 60% of the tested C. parapsilosis isolates were susceptible to KTZ, TERB and 5-FC, but ITZ and NYS were effective against all. By BMD, over 95% of M. pachydermatis isolates were susceptible to KTZ and ITZ with an MIC90 < 0.03 and 0.12 μg/ml, respectively. The frequency of KTZ- and ITZ-resistant C. parapsilosis was 29% and 7%, and the MIC90 values were 1 μg/ml and 0.5-1 μg/ml, respectively. Regarding the agreement analysis, 2.2% of minor errors were observed in M. pachydermatis and 0.2-1% of very major errors occurred among C. parapsilosis. There were no significant differences in the yeast resistance rates between dogs with and without SD. KTZ and ITZ were still efficacious for M. pachydermatis but a high rate of KTZ resistant was reported in C. parapsilosis. PMID:23547880

  7. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1115 Agar-agar. (a) Agar-agar (CAS Reg. No. PM 9002-18-0) is a...

  8. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1115 Agar-agar. (a) Agar-agar (CAS Reg. No. PM 9002-18-0) is a...

  9. Trends in frequency and in vitro antifungal susceptibility patterns of Candida isolates from women attending the STD outpatients clinic of a tertiary care hospital in Northern Italy during the years 2002-2007.

    PubMed

    Asticcioli, Sara; Sacco, Laura; Daturi, Rossana; Matti, Cecilia; Nucleo, Elisabetta; Zara, Francesca; Pagani, Laura

    2009-04-01

    Vulvovaginal candidiasis is a common mucosal infection caused by saprophytic and opportunistic yeasts belonging to the Candida genus. 518 vaginal swabs, with positive fungal culture were collected from unselected women attending the Sexually Transmitted Disease clinic of an Italian tertiary care hospital over a six year period to determine the pathogen prevalence in vulvovaginal candidiasis and to evaluate in vitro the antifungal susceptibilities of yeast recovered by Sensititre YeastOne antifungal panel plates according to CLSI document M27-A2. The isolates belonging to the genus Candida were 495 (95.5%) with Candida albicans percentage equal to 61.2%. Voriconazole was highly active (MIC50 0.008; MIC90 0.5 microg/ml), regardless of the species tested. On the contrary, fluconazole susceptibility was based upon the species. The intrinsic resistance to fluconazole of C. krusei was confirmed.

  10. Contribution of molecular typing methods and antifungal susceptibility testing to the study of a candidemia cluster in a burn care unit.

    PubMed Central

    Bart-Delabesse, E; van Deventer, H; Goessens, W; Poirot, J L; Lioret, N; van Belkum, A; Dromer, F

    1995-01-01

    We investigated a cluster of cases of Candida septicemia diagnosed in four burn patients. Twenty clinical isolates of Candida albicans and two of Candida parapsilosis, plus eight isolates of C. albicans recovered from nurses' clothes, were analyzed by antifungal susceptibility testing and three genotyping methods (restriction fragment length polymorphism analysis with EcoRI and HinfI, arbitrarily primed PCR, and karyotyping). The high MICs of the azoles for all of the C. albicans isolates tested suggest either a natural resistance of the endogenous flora or the transmission of isolates with acquired resistance. The genotyping methods demonstrated the involvement of four different strains, cross-infections with one C. albicans strain and one C. parapsilosis strain, and identity between some of the strains from the patients and nurses. The origins of the strains remain unclear. Our results show that the use of a combination of at least two different methods such as those used in the present study is recommended for C. albicans typing. PMID:8586717

  11. Association of genotypes with infection types and antifungal susceptibilities in Candida albicans as revealed by recent molecular typing strategies

    PubMed Central

    Bai, Feng-Yan

    2014-01-01

    Candida albicans is a commensal microorganism in the mucosa of healthy individuals, but is also the most common opportunistic fungal pathogen of humans. It causes from benign infections such as oral and vaginal candidiasis to fatal, systematic diseases in immunocompromised or critically ill patients. In addition to improved therapy, the rapid and accurate identification of the disease-causing strains is crucial for diagnosis, clinical treatment and epidemiological studies of candidiasis. A variety of methods for strain typing of C. albicans have been developed. The most commonly used methods with the focus on recently developed molecular typing or DNA-fingerprinting strategies and the recent findings in the association of specific and genetically similar genotypes with certain infection types and the correlation between azole susceptibilities and certain genotypes of C. albicans from China are reviewed. PMID:24772369

  12. Etiologic Agents and Antifungal Susceptibility of Oral Candidosis from Romanian patients with HIV-infection or type 1 diabetes mellitus.

    PubMed

    Minea, Bogdan; Nastasa, Valentin; Kolecka, Anna; Mares, Magdalena; Marangoci, Narcisa; Rosca, Irina; Pinteala, Mariana; Hancianu, Monica; Mares, Mihai

    2016-01-01

    This is the first Romanian investigation of oral candidosis in patients suffering of HIV-infection or type 1 diabetes mellitus (T1DM). Candida albicans was the dominant species in both types of isolates: n = 14 (46.7%) in T1DM, n = 60 (69.8%) in HIV. The most frequent non-albicans Candida spp. were Candida kefyr (n = 6; 20%) in T1DM and Candida dubliniensis (n = 8; 9.3%) in HIV. Resistance to fluconazole was detected only in the HIV non-albicans Candida group (n = 8; 9.3%). All isolates were susceptible to VOR. The experimental drug MXP had MIC values equal or close to the ones of VOR. Echinocandin resistance was more frequent than azole resistance. PMID:27282005

  13. Screening for Intermediately Vancomycin-Susceptible and Vancomycin-Heteroresistant Staphylococcus aureus by Use of Vancomycin-Supplemented Brain Heart Infusion Agar Biplates: Defining Growth Interpretation Criteria Based on Gold Standard Confirmation.

    PubMed

    Khatib, Riad; Riederer, Kathleen; Sharma, Mamta; Shemes, Stephen; Iyer, Sugantha P; Szpunar, Susan

    2015-11-01

    BHI agars supplemented with vancomycin 4 (BHI-V4) and 3 (BHI-V3) mg/liter have been proposed for screening vancomycin intermediately susceptible Staphylococcus aureus (VISA) and heteroresistant (hVISA) phenotypes, respectively, but growth interpretation criteria have not been established. We reviewed the growth results (CFU) during population analysis profile-area under the curve (PAP-AUC) of consecutive methicillin-resistant Staphylococcus aureus (MRSA) blood isolates, which were saved intermittently between 1996 and 2012. CFU counts on BHI-V4 and BHI-V3 plates were stratified according to PAP-AUC interpretive criteria: <0.90 (susceptible [S-MRSA]), 0.90 to 1.3 (hVISA), and >1.3 (VISA). CFU cutoffs that best predict VISA and hVISA were determined with the use of receiver operating characteristic (ROC) curves. Mu3, Mu50, and methicillin-susceptible S. aureus (MSSA) controls were included. We also prospectively evaluated manufacturer-made BHI-V3/BHI-V4 biplates for screening of 2010-2012 isolates. The PAP-AUC of 616 clinical samples was consistent with S-MRSA, hVISA, and VISA in 550 (89.3%), 48 (7.8%), and 18 (2.9%) instances, respectively. For VISA screening on BHI-V4, a cutoff of 2 CFU/droplet provided 100% sensitivity and 97.7% specificity. To distinguish VISA from hVISA, a cutoff of 16 CFU provided 83.3% sensitivity and 94.7% specificity; the specificity was lowered to 89.5% with a 12-CFU cutoff. For detecting hVISA/VISA on BHI-V3, a 2-CFU/droplet cutoff provided 98.5% sensitivity and 93.8% specificity. These results suggest that 2-CFU/droplet cutoffs on BHI-V4 and BHI-V3 best approximate VISA and hVISA gold standard confirmation, respectively, with minimal overlap in samples with borderline PAP-AUC. Simultaneous screening for VISA/hVISA on manufacturer-made BHI-V4/BHI-V3 biplates is easy to standardize and may reduce the requirement for PAP-AUC confirmation. PMID:26311860

  14. Screening for Intermediately Vancomycin-Susceptible and Vancomycin-Heteroresistant Staphylococcus aureus by Use of Vancomycin-Supplemented Brain Heart Infusion Agar Biplates: Defining Growth Interpretation Criteria Based on Gold Standard Confirmation.

    PubMed

    Khatib, Riad; Riederer, Kathleen; Sharma, Mamta; Shemes, Stephen; Iyer, Sugantha P; Szpunar, Susan

    2015-11-01

    BHI agars supplemented with vancomycin 4 (BHI-V4) and 3 (BHI-V3) mg/liter have been proposed for screening vancomycin intermediately susceptible Staphylococcus aureus (VISA) and heteroresistant (hVISA) phenotypes, respectively, but growth interpretation criteria have not been established. We reviewed the growth results (CFU) during population analysis profile-area under the curve (PAP-AUC) of consecutive methicillin-resistant Staphylococcus aureus (MRSA) blood isolates, which were saved intermittently between 1996 and 2012. CFU counts on BHI-V4 and BHI-V3 plates were stratified according to PAP-AUC interpretive criteria: <0.90 (susceptible [S-MRSA]), 0.90 to 1.3 (hVISA), and >1.3 (VISA). CFU cutoffs that best predict VISA and hVISA were determined with the use of receiver operating characteristic (ROC) curves. Mu3, Mu50, and methicillin-susceptible S. aureus (MSSA) controls were included. We also prospectively evaluated manufacturer-made BHI-V3/BHI-V4 biplates for screening of 2010-2012 isolates. The PAP-AUC of 616 clinical samples was consistent with S-MRSA, hVISA, and VISA in 550 (89.3%), 48 (7.8%), and 18 (2.9%) instances, respectively. For VISA screening on BHI-V4, a cutoff of 2 CFU/droplet provided 100% sensitivity and 97.7% specificity. To distinguish VISA from hVISA, a cutoff of 16 CFU provided 83.3% sensitivity and 94.7% specificity; the specificity was lowered to 89.5% with a 12-CFU cutoff. For detecting hVISA/VISA on BHI-V3, a 2-CFU/droplet cutoff provided 98.5% sensitivity and 93.8% specificity. These results suggest that 2-CFU/droplet cutoffs on BHI-V4 and BHI-V3 best approximate VISA and hVISA gold standard confirmation, respectively, with minimal overlap in samples with borderline PAP-AUC. Simultaneous screening for VISA/hVISA on manufacturer-made BHI-V4/BHI-V3 biplates is easy to standardize and may reduce the requirement for PAP-AUC confirmation.

  15. Results from the ARTEMIS DISK Global Antifungal Surveillance Study, 1997 to 2005: an 8.5-Year Analysis of Susceptibilities of Candida Species and Other Yeast Species to Fluconazole and Voriconazole Determined by CLSI Standardized Disk Diffusion Testing▿

    PubMed Central

    Pfaller, M. A.; Diekema, D. J.; Gibbs, D. L.; Newell, V. A.; Meis, J. F.; Gould, I. M.; Fu, W.; Colombo, A. L.; Rodriguez-Noriega, E.

    2007-01-01

    Fluconazole in vitro susceptibility test results for 205,329 yeasts were collected from 134 study sites in 40 countries from June 1997 through December 2005. Data were collected for 147,776 yeast isolates tested with voriconazole from 2001 through 2005. All investigators tested clinical yeast isolates by the CLSI M44-A disk diffusion method. Test plates were automatically read and results recorded with a BIOMIC image analysis system. Species, drug, zone diameter, susceptibility category, and quality control results were collected quarterly. Duplicate (same patient, same species, and same susceptible-resistant biotype profile during any 7-day period) and uncontrolled test results were not analyzed. Overall, 90.1% of all Candida isolates tested were susceptible (S) to fluconazole; however, 10 of the 22 species identified exhibited decreased susceptibility (<75% S) on the order of that seen with the resistant (R) species C. glabrata and C. krusei. Among 137,487 isolates of Candida spp. tested against voriconazole, 94.8% were S and 3.1% were R. Less than 30% of fluconazole-resistant isolates of C. albicans, C. glabrata, C. tropicalis, and C. rugosa remained S to voriconazole. The non-Candida yeasts (8,821 isolates) were generally less susceptible to fluconazole than Candida spp. but, aside from Rhodotorula spp., remained susceptible to voriconazole. This survey demonstrates the broad spectrum of these azoles against the most common opportunistic yeast pathogens but identifies several less common yeast species with decreased susceptibility to antifungal agents. These organisms may pose a future threat to optimal antifungal therapy and emphasize the importance of prompt and accurate species identification. PMID:17442797

  16. Candida albicans bloodstream isolates in a German university hospital are genetically heterogenous and susceptible to commonly used antifungals.

    PubMed

    Huyke, Johanna; Martin, Ronny; Walther, Grit; Weber, Michael; Kaerger, Kerstin; Bougnoux, Marie-Elisabeth; Elias, Johannes; Kurzai, Oliver

    2015-10-01

    From an eight-year-span, 99 Candida bloodstream isolates were collected at the University Hospital Wuerzburg, Germany. In this study, all strains were analyzed using molecular and phenotypic typing methods. Confirmatory species identification revealed three isolates that were initially diagnosed as C. albicans to be actually C. dubliniensis. Two isolates contained a mixed culture of C. albicans and C. glabrata, in one of the specimens both species could be separated while it was not possible to recover C. albicans in the other sample. The remaining 95 C. albicans isolates were profiled by multilocus sequence typing (MLST). Phylogenetic analyses showed a highly heterogenous collection of strains, associated with many different clades and constituting a set of new diploid sequence types (DST). For all strains with identical DST, patient data were reviewed for potential nosocomial transmission. In addition, all isolates were tested for their susceptibility to amphotericin B, caspofungin, fluconazole, itraconazole, posaconazole and voriconazole. No clinically relevant resistance could be detected. Furthermore, these data underline that correlation between minimal inhibitory concentrations for caspofungin and anidulafungin is low.

  17. Candida colonization in urine samples of ICU patients: determination of etiology, antifungal susceptibility testing and evaluation of associated risk factors.

    PubMed

    Singla, Nidhi; Gulati, Neelam; Kaistha, Neelam; Chander, Jagdish

    2012-08-01

    The presence of Candida in urine presents a therapeutic challenge for the physician as it is often asymptomatic, and management guidelines have not been clearly laid down on this issue. The presence of Candida in urine may represent contamination of clinical sample, actual colonization of the lower urinary tract or may be a true indicator of invasive infection of lower and/or upper urinary tract. In a clinical setting like the ICU, multiple risk factors for Candida colonization may be present in the same patient, thereby increasing the chances of candiduria, manifold. In the present study on 80 patients in ICU, high rate of Candida colonization (57.5%) was found in urine samples of ICU patients with C. tropicalis (57.3%) being the predominant species. We also isolated 8 strains of Trichosporon species, all of these presented as a mixed infection along with Candida species. Among the various risk factors studied, urinary catheterization and previous antibiotic therapy were identified as statistically significant (P value <0.05). The minimum inhibitory concentration of the isolates was determined for amphotericin B, fluconazole and itraconazole by E-test. Most of the isolates were susceptible to amphotericin B. The C. parapsilosis strains did not show any drug resistance; however, resistance to fluconazole was observed 18.6, 27.27, 50 and 25% in C. tropicalis, C. albicans, C. glabrata and Trichosporon species, respectively.

  18. Genotyping of Fusarium Isolates from Onychomycoses in Colombia: Detection of Two New Species Within the Fusarium solani Species Complex and In Vitro Antifungal Susceptibility Testing.

    PubMed

    Guevara-Suarez, Marcela; Cano-Lira, José Francisco; de García, María Caridad Cepero; Sopo, Leticia; De Bedout, Catalina; Cano, Luz Elena; García, Ana María; Motta, Adriana; Amézquita, Adolfo; Cárdenas, Martha; Espinel-Ingroff, Ana; Guarro, Josep; Restrepo, Silvia; Celis, Adriana

    2016-04-01

    Fusariosis have been increasing in Colombia in recent years, but its epidemiology is poorly known. We have morphologically and molecularly characterized 89 isolates of Fusarium obtained between 2010 and 2012 in the cities of Bogotá and Medellín. Using a multi-locus sequence analysis of rDNA internal transcribed spacer, a fragment of the translation elongation factor 1-alpha (Tef-1α) and of the RNA-dependent polymerase subunit II (Rpb2) genes, we identified the phylogenetic species and circulating haplotypes. Since most of the isolates studied were from onychomycoses (nearly 90 %), we carried out an epidemiological study to determine the risk factors associated with such infections. Five phylogenetic species of the Fusarium solani species complex (FSSC), i.e., F. falciforme, F. keratoplasticum, F. lichenicola, F. petroliphilum, and FSSC 6 as well as two of the Fusarium oxysporum species complex (FOSC), i.e., FOSC 3 and FOSC 4, were identified. The most prevalent species were FOSC 3 (38.2%) followed by F. keratoplasticum (33.7%). In addition, our isolates were distributed into 23 haplotypes (14 into FOSC and nine into FSSC). Two of the FSSC phylogenetic species and two haplotypes of FSSC were not described before. Our results demonstrate that recipients of pedicure treatments have a lower probability of acquiring onychomycosis than those not receiving such treatments. The antifungal susceptibility of all the isolates to five clinically available agents showed that amphotericin B was the most active drug, while the azoles exhibited lower in vitro activity. PMID:26943726

  19. Genotyping of Fusarium Isolates from Onychomycoses in Colombia: Detection of Two New Species Within the Fusarium solani Species Complex and In Vitro Antifungal Susceptibility Testing.

    PubMed

    Guevara-Suarez, Marcela; Cano-Lira, José Francisco; de García, María Caridad Cepero; Sopo, Leticia; De Bedout, Catalina; Cano, Luz Elena; García, Ana María; Motta, Adriana; Amézquita, Adolfo; Cárdenas, Martha; Espinel-Ingroff, Ana; Guarro, Josep; Restrepo, Silvia; Celis, Adriana

    2016-04-01

    Fusariosis have been increasing in Colombia in recent years, but its epidemiology is poorly known. We have morphologically and molecularly characterized 89 isolates of Fusarium obtained between 2010 and 2012 in the cities of Bogotá and Medellín. Using a multi-locus sequence analysis of rDNA internal transcribed spacer, a fragment of the translation elongation factor 1-alpha (Tef-1α) and of the RNA-dependent polymerase subunit II (Rpb2) genes, we identified the phylogenetic species and circulating haplotypes. Since most of the isolates studied were from onychomycoses (nearly 90 %), we carried out an epidemiological study to determine the risk factors associated with such infections. Five phylogenetic species of the Fusarium solani species complex (FSSC), i.e., F. falciforme, F. keratoplasticum, F. lichenicola, F. petroliphilum, and FSSC 6 as well as two of the Fusarium oxysporum species complex (FOSC), i.e., FOSC 3 and FOSC 4, were identified. The most prevalent species were FOSC 3 (38.2%) followed by F. keratoplasticum (33.7%). In addition, our isolates were distributed into 23 haplotypes (14 into FOSC and nine into FSSC). Two of the FSSC phylogenetic species and two haplotypes of FSSC were not described before. Our results demonstrate that recipients of pedicure treatments have a lower probability of acquiring onychomycosis than those not receiving such treatments. The antifungal susceptibility of all the isolates to five clinically available agents showed that amphotericin B was the most active drug, while the azoles exhibited lower in vitro activity.

  20. Antifungal and cytotoxic activities of Nannorrhops ritchiana roots extract.

    PubMed

    Rashid, Rehana; Mukhtar, Farah; Khan, Abida

    2014-01-01

    This atudy was designed to evaluate the antifungal and cytotoxic activities of the Nannorrhops ritchiana (Mazari Palm) 80% methanol extract (NR-M) and its four crude extracts i.e., petroleum ether (NR-A), dichloromethane (NR-B), ethyl acetate (NR-C) and butanol (NR-D). The antifungal activity was determined by agar tube dilution method against nine fungal strains; Aspergillus flavus, Trichophyton longifusis, Trichophyton mentagrophytes, Aspergillus flavus and Microsporum canis were susceptible to the extracts with percentage inhibition of (70-80%). Extracts exhibited significant and good antifungal activity against various fungal strains. The results were deduced by comparing with those for miconazole, amphotericin B and ketoconazole as standard drugs. The fractions of methanolic extract were assayed for their brine shrimp cytotoxic activity. They exhibited low toxicity with LC50 values ranging from 285.7 to 4350.75 μg/mL at the concentration of obtained results warrant follow up through bioassay guided isolation of the active principles, future antiinfectious research. PMID:25362807

  1. Antifungal and Antibacterial Metabolites from a French Poplar Type Propolis

    PubMed Central

    Boisard, Séverine; Le Ray, Anne-Marie; Landreau, Anne; Kempf, Marie; Cassisa, Viviane; Flurin, Catherine; Richomme, Pascal

    2015-01-01

    During this study, the in vitro antifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains: Candida albicans, C. glabrata, and Aspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains including Staphylococcus aureus. Organic extracts showed a significant antifungal activity against C. albicans and C. glabrata (MIC80 between 16 and 31 µg/mL) but only a weak activity towards A. fumigatus (MIC80 = 250 µg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially against S. aureus (SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC100 30–97 µg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study. PMID:25873978

  2. Performance of the EUCAST disk diffusion method, the CLSI agar screen method, and the Vitek 2 automated antimicrobial susceptibility testing system for detection of clinical isolates of Enterococci with low- and medium-level VanB-type vancomycin resistance: a multicenter study.

    PubMed

    Hegstad, Kristin; Giske, Christian G; Haldorsen, Bjørg; Matuschek, Erika; Schønning, Kristian; Leegaard, Truls M; Kahlmeter, Gunnar; Sundsfjord, Arnfinn

    2014-05-01

    Different antimicrobial susceptibility testing methods to detect low-level vancomycin resistance in enterococci were evaluated in a Scandinavian multicenter study (n=28). A phenotypically and genotypically well-characterized diverse collection of Enterococcus faecalis (n=12) and Enterococcus faecium (n=18) strains with and without nonsusceptibility to vancomycin was examined blindly in Danish (n=5), Norwegian (n=13), and Swedish (n=10) laboratories using the EUCAST disk diffusion method (n=28) and the CLSI agar screen (n=18) or the Vitek 2 system (bioMérieux) (n=5). The EUCAST disk diffusion method (very major error [VME] rate, 7.0%; sensitivity, 0.93; major error [ME] rate, 2.4%; specificity, 0.98) and CLSI agar screen (VME rate, 6.6%; sensitivity, 0.93; ME rate, 5.6%; specificity, 0.94) performed significantly better (P=0.02) than the Vitek 2 system (VME rate, 13%; sensitivity, 0.87; ME rate, 0%; specificity, 1). The performance of the EUCAST disk diffusion method was challenged by differences in vancomycin inhibition zone sizes as well as the experience of the personnel in interpreting fuzzy zone edges as an indication of vancomycin resistance. Laboratories using Oxoid agar (P<0.0001) or Merck Mueller-Hinton (MH) agar (P=0.027) for the disk diffusion assay performed significantly better than did laboratories using BBL MH II medium. Laboratories using Difco brain heart infusion (BHI) agar for the CLSI agar screen performed significantly better (P=0.017) than did those using Oxoid BHI agar. In conclusion, both the EUCAST disk diffusion and CLSI agar screening methods performed acceptably (sensitivity, 0.93; specificity, 0.94 to 0.98) in the detection of VanB-type vancomycin-resistant enterococci with low-level resistance. Importantly, use of the CLSI agar screen requires careful monitoring of the vancomycin concentration in the plates. Moreover, disk diffusion methodology requires that personnel be trained in interpreting zone edges.

  3. [Comparison of the results of determining antibiotic sensitivity on AGV medium and on Mueller-Hinton and isosensitest agars].

    PubMed

    Kozlov, R S; Strachunskiĭ, L S; Livermor, D M; Stetsiuk, O U; Shavrikova, E P

    1996-01-01

    To evaluate the adequacy of AGV agar for antimicrobial susceptibility testing, the susceptibility of a range of bacteria to 10 antimicrobials on AGV, Mueller-Hinton and isoSensitest agars, all supplemented with 5 per cent lyzed horse blood was determined. Disc tests were used. In general, AGV agar gave identical susceptibility results to Mueller-Hinton and isoSensitest agars for common gram positive and gram negative bacteria with most of the tested microbials excluding sulphonamides and trimethoprim. With those latter antimicrobials inhibition zones for susceptible organisms were not formed on AGV agar whereas large zones were present on Mueller-Hinton and isoSensitest agars. This discrepancy probably can be explained by the presence of high levels of thymidine in AGV agar; too high to be corrected even by the addition of 5 per cent lysed horse blood. AGV agar is possible to use for susceptibility testing with most of the microbials excluding trimethoprim and sulphonamides.

  4. Syneresis in agar hydrogels.

    PubMed

    Boral, Shilpi; Saxena, Anita; Bohidar, H B

    2010-03-01

    Agar hydrogels exhibit syneresis which creates internal osmotic stress on the physical network. It was observed that such a stress gives rise to characteristic pulsating modes (breathing modes). Experiments carried over a period of 60-day revealed that the network deformations grew monotonously when the solvent released by syneresis was removed periodically from gel surface. However, when the solvent was not withdrawn, the gel exhibited very slowly relaxing breathing modes. The swelling-deswelling dynamics has been discussed in the generalized framework of a dissipative damped oscillator.

  5. Antifungal activity of Cynara scolymus L. extracts.

    PubMed

    Zhu, X F; Zhang, H X; Lo, R

    2005-01-01

    Chloroform, ethanol and ethyl acetate extracts of Cynara scolymus L. leaves, heads and stems were tested for their antifungal activity using the agar-well diffusion assay technique. The leaves extracts and the ethanol fractions were found to be the most effective extract against all the tested organisms.

  6. Molecular Epidemiology and In-Vitro Antifungal Susceptibility of Aspergillus terreus Species Complex Isolates in Delhi, India: Evidence of Genetic Diversity by Amplified Fragment Length Polymorphism and Microsatellite Typing

    PubMed Central

    Kathuria, Shallu; Sharma, Cheshta; Singh, Pradeep Kumar; Agarwal, Puneet; Agarwal, Kshitij; Hagen, Ferry; Meis, Jacques F.; Chowdhary, Anuradha

    2015-01-01

    Aspergillus terreus is emerging as an etiologic agent of invasive aspergillosis in immunocompromised individuals in several medical centers in the world. Infections due to A. terreus are of concern due to its resistance to amphotericin B, in vivo and in vitro, resulting in poor response to antifungal therapy and high mortality. Herein we examined a large collection of molecularly characterized, geographically diverse A. terreus isolates (n = 140) from clinical and environmental sources in India for the occurrence of cryptic A. terreus species. The population structure of the Indian A. terreus isolates and their association with those outside India was determined using microsatellite based typing (STR) technique and Amplified Fragment Length Polymorphism analysis (AFLP). Additionally, in vitro antifungal susceptibility of A. terreus isolates was determined against 7 antifungals. Sequence analyses of the calmodulin locus identified the recently described cryptic species A. hortai, comprising 1.4% of Aspergillus section Terrei isolates cultured from cases of aspergilloma and probable invasive aspergillosis not reported previously. All the nine markers used for STR typing of A. terreus species complex proved to be highly polymorphic. The presence of high genetic diversity revealing 75 distinct genotypes among 101 Indian A. terreus isolates was similar to the marked heterogeneity noticed in the 47 global A. terreus population exhibiting 38 unique genotypes mainly among isolates from North America and Europe. Also, AFLP analysis showed distinct banding patterns for genotypically diverse A. terreus isolates. Furthermore, no correlation between a particular genotype and amphotericin B susceptibility was observed. Overall, 8% of the A. terreus isolates exhibited low MICs of amphotericin B. All the echinocandins and azoles (voriconazole, posaconazole and isavuconazole) demonstrated high potency against all the isolates. The study emphasizes the need of molecular

  7. 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. PMID:15619579

  8. 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.

  9. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  10. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  11. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD... ingredient meets the specifications of the “Food Chemicals Codex,” 3d Ed. (1981), p. 11, which...

  12. Isavuconazole, micafungin, and 8 comparator antifungal agents' susceptibility profiles for common and uncommon opportunistic fungi collected in 2013: temporal analysis of antifungal drug resistance using CLSI species-specific clinical breakpoints and proposed epidemiological cutoff values.

    PubMed

    Pfaller, M A; Rhomberg, P R; Messer, S A; Jones, R N; Castanheira, M

    2015-08-01

    The in vitro activities of isavuconazole, micafungin, and 8 comparator antifungal agents were determined for 1613 clinical isolates of fungi (1320 isolates of Candida spp., 155 of Aspergillus spp., 103 of non-Candida yeasts, and 35 non-Aspergillus molds) collected during a global survey conducted in 2013. The vast majority of the isolates of the 21 different species of Candida, with the exception of Candida glabrata (MIC90, 2 μg/mL), Candida krusei (MIC90, 1 μg/mL), and Candida guilliermondii (MIC90, 8 μg/mL), were inhibited by ≤0.25 μg/mL of isavuconazole. C. glabrata and C. krusei were largely inhibited by ≤1 μg/mL of isavuconazole. Resistance to fluconazole was seen in 0.5% of Candida albicans isolates, 11.1% of C. glabrata isolates, 2.5% of Candida parapsilosis isolates, 4.5% of Candida tropicalis isolates, and 20.0% of C. guilliermondii isolates. Resistance to the echinocandins was restricted to C. glabrata (1.3-2.1%) and C. tropicalis (0.9-1.8%). All agents except for the echinocandins were active against 69 Cryptococcus neoformans isolates, and the triazoles, including isavuconazole, were active against the other yeasts. Both the mold active triazoles as well as the echinocandins were active against 155 Aspergillus spp. isolates belonging to 10 species/species complex. In general, there was low resistance levels to the available systemically active antifungal agents in a large, contemporary (2013), global collection of molecularly characterized yeasts and molds. Resistance to azoles and echinocandins was most prominent among isolates of C. glabrata, C. tropicalis, and C. guilliermondii.

  13. Antifungal activity from Ocimum gratissimum L. towards Cryptococcus neoformans.

    PubMed

    Lemos, Janine de Aquino; Passos, Xisto Sena; Fernandes, Orionalda de Fátima Lisboa; Paula, José Realino de; Ferri, Pedro Henrique; Souza, Lúcia Kioko Hasimoto E; Lemos, Aline de Aquino; Silva, Maria do Rosário Rodrigues

    2005-02-01

    Cryptococcal infection had an increased incidence in last years due to the explosion of acquired immune deficiency syndrome epidemic and by using new and effective immunosuppressive agents. The currently antifungal therapies used such as amphotericin B, fluconazole, and itraconazole have certain limitations due to side effects and emergence of resistant strains. So, a permanent search to find new drugs for cryptococcosis treatment is essential. Ocimum gratissimum, plant known as alfavaca (Labiatae family), has been reported earlier with in vitro activity against some bacteria and dermatophytes. In our work, we study the in vitro activity of the ethanolic crude extract, ethyl acetate, hexane, and chloroformic fractions, essential oil, and eugenol of O. gratissimum using an agar dilution susceptibility method towards 25 isolates of Cryptococcus neoformans. All the extracts of O. gratissimum studied showed activity in vitro towards C. neoformans. Based on the minimal inhibitory concentration values the most significant results were obtained with chloroformic fraction and eugenol. It was observed that chloroformic fraction inhibited 23 isolates (92%) of C. neoformans at a concentration of 62.5 microg/ml and eugenol inhibited 4 isolates (16%) at a concentration of 0.9 microg/ml. This screening may be the basis for the study of O. gratissimum as a possible antifungal agent. PMID:15867965

  14. Results from the ARTEMIS DISK Global Antifungal Surveillance Study: a 6.5-Year Analysis of Susceptibilities of Candida and Other Yeast Species to Fluconazole and Voriconazole by Standardized Disk Diffusion Testing

    PubMed Central

    Pfaller, M. A.; Diekema, D. J.; Rinaldi, M. G.; Barnes, R.; Hu, B.; Veselov, A. V.; Tiraboschi, N.; Nagy, E.; Gibbs, D. L.

    2005-01-01

    Fluconazole in vitro susceptibility test results for 140,767 yeasts were collected from 127 participating investigators in 39 countries from June 1997 through December 2003. Data were collected on 79,343 yeast isolates tested with voriconazole from 2001 through 2003. All investigators tested clinical yeast isolates by the CLSI (formerly NCCLS) M44-A disk diffusion method. Test plates were automatically read and results were recorded with the BIOMIC Vision Image Analysis System. Species, drug, zone diameter, susceptibility category, and quality control results were collected quarterly via e-mail for analysis. Duplicate (the same patient, same species, and same susceptible-resistant biotype profile during any 7-day period) and uncontrolled test results were not analyzed. The 10 most common species of yeasts all showed less resistance to voriconazole than to fluconazole. Candida krusei showed the largest difference, with over 70% resistance to fluconazole and less than 8% to voriconazole. All species of yeasts tested were more susceptible to voriconazole than to fluconazole, assuming proposed interpretive breakpoints of ≥17 mm (susceptible) and ≤13 mm (resistant) for voriconazole. MICs reported in this study were determined from the zone diameter in millimeters from the continuous agar gradient around each disk, which was calibrated with MICs determined from the standard CLSI M27-A2 broth dilution method by balanced-weight regression analysis. The results from this investigation demonstrate the broad spectrum of the azoles for most of the opportunistic yeast pathogens but also highlight several areas where resistance may be progressing and/or where previously rare species may be “emerging.” PMID:16333066

  15. Antifungal Activity of Cinnamon Oil and Olive Oil against Candida Spp. Isolated from Blood Stream Infections

    PubMed Central

    Rohilla, Hina; Singh, Gajender; Punia, Parul

    2016-01-01

    Introduction Recently non-albicans Candida has emerged as a major cause of morbidity and mortality in blood stream infections. Some species of the Candida are becoming increasingly resistant to first line and second line antifungals such as echinocandins and fluconazole. In view of increasing global antifungal resistance, role of alternative and better antifungals like natural plant products need to be explored. Essential oils are known to exhibit antimicrobial activity against various fungi. Hence, we evaluated the efficacy of cinnamon oil and olive oil against Candida spp. Aim To evaluate the invitro antifungal activity of olive oil and cinnamon oil against blood stream Candida isolates. Materials and Methods The present prospective observational study was conducted in the Department of Microbiology at a tertiary care teaching hospital during one year June 2011-July 2012. Blood samples were collected from 1376 patients clinically suspected to have fungal septicaemia, out of which 100 (7.2%) Candida isolates obtained, were speciated by conventional methods. Antifungal susceptibility testing of all the isolates was done against fluconazole, voriconazole as per NCCL (M27-A2) and against olive oil and cinnamon oil by agar well diffusion method. Results Prevalence of Candidemia was 7.26%. C. albicans (85.3%) and C. parapsilosis (85.7%) were most sensitive to fluconazole followed by C. tropicalis (67.4%). All isolates were 100% sensitive to voriconazole. Both oils were found to be effective against nearly 50% of the Candida isolates. About 55.5% of fluconazole resistant C. krusei strains were sensitive to olive and cinnamon oil. Conclusion Fluconazole resistant non-albicans Candida has emerged as major cause of Candidemia. Cinnamon and olive oil show marked sensitivity against albicans and non-albicans spp. PMID:27656437

  16. A Prospective Surveillance Study of Candidaemia: Epidemiology, Risk Factors, Antifungal Treatment and Outcome in Hospitalized Patients

    PubMed Central

    Rajendran, Ranjith; Sherry, Leighann; Deshpande, Ashutosh; Johnson, Elizabeth M.; Hanson, Mary F.; Williams, Craig; Munro, Carol A.; Jones, Brian L.; Ramage, Gordon

    2016-01-01

    This study provide an up-to-date overview of the epidemiology and risk factors for Candida bloodstream infection in Scotland in 2012/2013, and the antifungal susceptibility of isolates from blood cultures from 11 National Health Service boards within Scotland. Candida isolates were identified by chromogenic agar and confirmed by MALDI–TOF methods. Survival and associated risk factors for patients stratified as albicans and non-albicans cases were assessed. Information on the spectrum of antifungals used was collected and summarized. The isolates sensitivity to different antifungals was tested by broth microdilution method and interpreted according to CLSI/EUCAST guidelines. Forty one percent of candidaemia cases were associated with Candida albicans, followed by C. glabrata (35%), C. parapsilosis (11.5%), and remainder with other Candida spp. C. albicans and C. glabrata infections were associated with 20.9 and 16.3% mortality, respectively. Survival of patients with C. albicans was significantly lower compared to non-C. albicans and catheter line removal in C. albicans patients significantly increases the survival days. Predisposing factors such as total parenteral nutrition, and number of days on mechanical ventilation or in intensive care, were significantly associated with C. albicans infections. Fluconazole was used extensively (64.5%) for treating candidaemia cases followed by echinocandins (33.8%). Based on CLSI breakpoints, MIC test found no resistance to any antifungals tested except 5.26% fluconazole resistance among C. glabrata isolates. Moreover, by comparing to EUCAST breakpoints we found 3.95% of C. glabrata isolates were resistant to anidulafungin. We have observed a shift in Candida spp. with an increasing isolation of C. glabrata. Delay and choice of antifungal treatment are associated with poor clinical outcomes. PMID:27379047

  17. 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. PMID:23111348

  18. As a bacterial culture medium, citrated sheep blood agar is a practical alternative to citrated human blood agar in laboratories of developing countries.

    PubMed

    Russell, F M; Biribo, S S N; Selvaraj, G; Oppedisano, F; Warren, S; Seduadua, A; Mulholland, E K; Carapetis, J R

    2006-09-01

    Human blood agar (HuBA) is widely used in developing countries for the isolation of bacteria from clinical specimens. This study compared citrated sheep blood agar (CSBA) and HuBA with defibrinated horse blood agar and defibrinated sheep blood agar (DSBA) for the isolation and antibiotic susceptibility testing of reference and clinical strains of Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus. Reference and clinical strains of all organisms were diluted in brain heart infusion and a clinical specimen of cerebrospinal fluid and cultured on all agars. Viable counts, colony morphology, and colony size were recorded. Susceptibility testing for S. pneumoniae and S. pyogenes was performed on defibrinated sheep blood Mueller-Hinton agar, citrated sheep blood Mueller-Hinton agar (CSB MHA), and human blood Mueller-Hinton agar plates. For all organisms, the colony numbers were similar on all agars. Substantially smaller colony sizes and absent or minimal hemolysis were noted on HuBA for all organisms. Antibiotic susceptibility results for S. pneumoniae were similar for the two sheep blood agars; however, larger zone sizes were displayed on HuBA, and quality control for the reference strain failed on HuBA. For S. pyogenes, larger zone sizes were demonstrated on HuBA and CSBA than on DSBA. Poor hemolysis made interpretation of the zone sizes difficult on HuBA. CSBA is an acceptable alternative for the isolation of these organisms. The characteristic morphology is not evident, and hemolysis is poor on HuBA; and so HuBA is not recommended for use for the isolation or the susceptibility testing of any of these organisms. CSB MHA may be suitable for use for the susceptibility testing of S. pneumoniae.

  19. [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.

  20. 48 CFR 401.371 - AGAR Advisories.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false AGAR Advisories. 401.371... ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 401.371 AGAR Advisories. The SPE may issue AGAR Advisories, consistent with the policies of the FAR and the AGAR, for the following purposes: (a)...

  1. 48 CFR 401.371 - AGAR Advisories.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false AGAR Advisories. 401.371... ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 401.371 AGAR Advisories. The SPE may issue AGAR Advisories, consistent with the policies of the FAR and the AGAR, for the following purposes: (a)...

  2. 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. PMID:27135278

  3. Antifungal properties of halofumarate esters.

    PubMed

    Gershon, H; Shanks, L

    1978-04-01

    Alkyl esters (C1--C4) of the four halofumaric acids were tested for antifungal activity against Candida albicans, Aspergillus niger, Mucor mucedo, and Trichophyton mentagrophytes at pH 5.6 and 7.0 in the absence and presence of 10% beef serum in Sabouraud dextrose agar. The most toxic compound to each organism was: C. albicans, ethyl iodofumarate (0.054 mmole/liter); A. niger, methyl bromofumarate (0.090 mmole/liter); M. mucedo, methyl fluorofumarate (0.037 mmole/liter); and T. mentagrophytes, ethyl iodofumarate (0.020 mmole/liter). The order of overall activity of the six most toxic compounds was: ethyl iodofumarate greater than ethyl chlorofumarate greater than methyl iodofumarate = methyl bromofumarate greater than methyl chlorofumarate greater than bromofumarate.

  4. Laboratory tests of antifungal drugs.

    PubMed Central

    Holt, R J

    1975-01-01

    The procedures evolved in the author's laboratory over the past 20 years for the microbiological assessment of antifungal drugs are described; methods are detailed for the estimation of the sensitivity of pathogenic fungi to therapeutic agents and for the assay of those agents in body fluids. The preparation and maintenance of stock reference solutions of the drugs, the culture media used, and the incubation temperature and time are discussed. Sensitivity tests by paper disc and by liquid titration for minimal inhibitory and cidal concentrations estimated are described, and the importance of standardized initial inocula is emphasized. Two groups of assay procedures are given, the liquid dilution and the agar diffusion methods, and suitable indicator organisms for both methods are named. The paper concludes with a discussion on the problem of differential assays when two antimycotic agents are in simultaneous clinical use. Images PMID:765359

  5. Standard Nutrient Agar 1 as a substitute for blood-supplemented Müller-Hinton agar for antibiograms in developing countries.

    PubMed

    Niederstebruch, N; Sixt, D

    2013-02-01

    In the industrial world, the agar diffusion test is a standard procedure for the susceptibility testing of bacteria isolates. Beta-hemolytic Streptococcus spp. are tested with Müller-Hinton agar supplemented with 5 % blood, a so-called blood agar. The results are interpreted using standardized tables, which only exist for this type of nutrient matrix. Because of a number difficulties, both with respect to technical issues and to manual skills, blood agar is not a feasible option in many developing countries. Beta-hemolytic Streptococcus spp. also grow on Standard Nutrient Agar 1 (StNA1). This suggests using that type of nutrient medium for running agar diffusion tests. However, there are no standardized tables that can be used for interpreting the diameters of the zones of inhibition on StNA1 1. Using the existing standardized tables for blood agar to interpret cultures on StNA1 1 would be of great benefit under such circumstances where blood agar is not available. With this in mind, we conducted comparative tests to evaluate the growth characteristics of beta-hemolytic Streptococcus spp. on StNA1 1 compared to Müller-Hinton agar supplemented with 5 % sheep blood. In this study, we were able to show that beta-hemolytic Streptococcus spp. develop similar zones of inhibition on blood agar and on StNA1 1. Therefore, it is suggested that, for the interpretation of antibiograms of beta-hemolytic Streptococcus spp. performed on StNA1 1, the standard tables for blood agar can be used.

  6. Standard Nutrient Agar 1 as a substitute for blood-supplemented Müller-Hinton agar for antibiograms in developing countries.

    PubMed

    Niederstebruch, N; Sixt, D

    2013-02-01

    In the industrial world, the agar diffusion test is a standard procedure for the susceptibility testing of bacteria isolates. Beta-hemolytic Streptococcus spp. are tested with Müller-Hinton agar supplemented with 5 % blood, a so-called blood agar. The results are interpreted using standardized tables, which only exist for this type of nutrient matrix. Because of a number difficulties, both with respect to technical issues and to manual skills, blood agar is not a feasible option in many developing countries. Beta-hemolytic Streptococcus spp. also grow on Standard Nutrient Agar 1 (StNA1). This suggests using that type of nutrient medium for running agar diffusion tests. However, there are no standardized tables that can be used for interpreting the diameters of the zones of inhibition on StNA1 1. Using the existing standardized tables for blood agar to interpret cultures on StNA1 1 would be of great benefit under such circumstances where blood agar is not available. With this in mind, we conducted comparative tests to evaluate the growth characteristics of beta-hemolytic Streptococcus spp. on StNA1 1 compared to Müller-Hinton agar supplemented with 5 % sheep blood. In this study, we were able to show that beta-hemolytic Streptococcus spp. develop similar zones of inhibition on blood agar and on StNA1 1. Therefore, it is suggested that, for the interpretation of antibiograms of beta-hemolytic Streptococcus spp. performed on StNA1 1, the standard tables for blood agar can be used. PMID:22926453

  7. Identification by Molecular Methods and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry and Antifungal Susceptibility Profiles of Clinically Significant Rare Aspergillus Species in a Referral Chest Hospital in Delhi, India.

    PubMed

    Masih, Aradhana; Singh, Pradeep K; Kathuria, Shallu; Agarwal, Kshitij; Meis, Jacques F; Chowdhary, Anuradha

    2016-09-01

    Aspergillus species cause a wide spectrum of clinical infections. Although Aspergillus fumigatus and Aspergillus flavus remain the most commonly isolated species in aspergillosis, in the last decade, rare and cryptic Aspergillus species have emerged in diverse clinical settings. The present study analyzed the distribution and in vitro antifungal susceptibility profiles of rare Aspergillus species in clinical samples from patients with suspected aspergillosis in 8 medical centers in India. Further, a matrix-assisted laser desorption ionization-time of flight mass spectrometry in-house database was developed to identify these clinically relevant Aspergillus species. β-Tubulin and calmodulin gene sequencing identified 45 rare Aspergillus isolates to the species level, except for a solitary isolate. They included 23 less common Aspergillus species belonging to 12 sections, mainly in Circumdati, Nidulantes, Flavi, Terrei, Versicolores, Aspergillus, and Nigri Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) identified only 8 (38%) of the 23 rare Aspergillus isolates to the species level. Following the creation of an in-house database with the remaining 14 species not available in the Bruker database, the MALDI-TOF MS identification rate increased to 95%. Overall, high MICs of ≥2 μg/ml were noted for amphotericin B in 29% of the rare Aspergillus species, followed by voriconazole in 20% and isavuconazole in 7%, whereas MICs of >0.5 μg/ml for posaconazole were observed in 15% of the isolates. Regarding the clinical diagnoses in 45 patients with positive rare Aspergillus species cultures, 19 (42%) were regarded to represent colonization. In the remaining 26 patients, rare Aspergillus species were the etiologic agent of invasive, chronic, and allergic bronchopulmonary aspergillosis, allergic fungal rhinosinusitis, keratitis, and mycetoma. PMID:27413188

  8. [Presumptive identification of Candida spp. and other clinically important yeasts: usefulness of Brilliance Candida Agar].

    PubMed

    Alfonso, Claudia; López, Mónica; Arechavala, Alicia; Perrone, María Del Carmen; Guelfand, Liliana; Bianchi, Mario

    2010-06-30

    Fungal infections caused by yeasts have increased during the last decades and invasive forms represent a serious problem for human health. Candida albicans is the species most frequently isolated from clinical samples. However, other emerging yeast pathogens are increasingly responsible for mycotic infections, and some of them are resistant to some antifungal drugs. Consequently, it is necessary to have methods that can provide a rapid presumptive identification at species level. Numerous chromogenic agar media have been shown to be of value as diagnostic tools. We have compared a chromogenic medium, Brilliance Candida Agar, with CHROMagar Candida, the chromogenic medium most used in our country. A multicentre study was conducted in 16 Hospitals belonging to the Mycology Net of Buenos Aires City Government. A total of 240 yeast isolates were included in this research. The new chromogenic agar showed results very similar to those obtained with CHROMagar Candida.

  9. Crystal formation in furunculosis agar

    USGS Publications Warehouse

    Bullock, G.L.; Ross, A.J.

    1964-01-01

    SINCE ITS INTRODUCTION SOME MONTHS AGO, FURUNCULOSIS AGAR has been employed in the diagnosis of suspect furunculosis and also as a general purpose medium. During our work with this medium we have noticed discrete "colonies," of crystalline material, which very closely resemble microbial colonies. These crystal colonies are compact and appear on both the surface and subsurface; they occur in inoculated slants and plates incubated for long periods (2 to 3 weeks), as well as in uninoculated stored medium. As the crystal colonies could be confusing to workers using this medium, we decided to attempt to identify them and also to determine whether storage conditions and different lots of medium affect crystal formation.

  10. Antifungal activity of three mouth rinses--in vitro study.

    PubMed

    Abirami, C P; Venugopal, Pankajalakshmi V

    2005-01-01

    Mouthrinses are nowadays routinely included in the home care oral hygiene maintenance besides dentifrice/tooth paste. Mouthrinses prevent bacterial attachment and prevent or slow down bacterial proliferation. Fungal organisms have now gained more importance due to increased incidence of AIDS/HIV. This has necessitated for mouthrinses to possess antifungal activity also. The mouthrinses used were Povidone iodine ( Wokadine), Thymol with Eucalyptol and Benzoic acid (Listerine) and fluoride with Triclosan (Colgate Plax), which were tested against oral isolates of different species of Candida. The agar diffusion test was used to evaluate the inhibitory activity of the mouthrinses and all of them exhibited antifungal activity especially against Candida albicans. PMID:16758789

  11. Antifungal activity of three mouth rinses--in vitro study.

    PubMed

    Abirami, C P; Venugopal, Pankajalakshmi V

    2005-01-01

    Mouthrinses are nowadays routinely included in the home care oral hygiene maintenance besides dentifrice/tooth paste. Mouthrinses prevent bacterial attachment and prevent or slow down bacterial proliferation. Fungal organisms have now gained more importance due to increased incidence of AIDS/HIV. This has necessitated for mouthrinses to possess antifungal activity also. The mouthrinses used were Povidone iodine ( Wokadine), Thymol with Eucalyptol and Benzoic acid (Listerine) and fluoride with Triclosan (Colgate Plax), which were tested against oral isolates of different species of Candida. The agar diffusion test was used to evaluate the inhibitory activity of the mouthrinses and all of them exhibited antifungal activity especially against Candida albicans.

  12. Multidrug-Resistant Candida auris Misidentified as Candida haemulonii: Characterization by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry and DNA Sequencing and Its Antifungal Susceptibility Profile Variability by Vitek 2, CLSI Broth Microdilution, and Etest Method.

    PubMed

    Kathuria, Shallu; Singh, Pradeep K; Sharma, Cheshta; Prakash, Anupam; Masih, Aradhana; Kumar, Anil; Meis, Jacques F; Chowdhary, Anuradha

    2015-06-01

    Candida auris is a multidrug-resistant yeast that causes a wide spectrum of infections, especially in intensive care settings. We investigated C. auris prevalence among 102 clinical isolates previously identified as Candida haemulonii or Candida famata by the Vitek 2 system. Internal transcribed spacer region (ITS) sequencing confirmed 88.2% of the isolates as C. auris, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) easily separated all related species, viz., C. auris (n = 90), C. haemulonii (n = 6), C. haemulonii var. vulnera (n = 1), and Candida duobushaemulonii (n = 5). The in vitro antifungal susceptibility was determined using CLSI broth microdilution (CLSI-BMD), the Vitek 2 antifungal susceptibility test, and the Etest method. C. auris isolates revealed uniformly elevated fluconazole MICs (MIC50, 64 μg/ml), and an alarming percentage of isolates (37%) exhibited elevated caspofungin MICs by CLSI-BMD. Notably, 34% of C. auris isolates had coexisting elevated MICs (≥2 μg/ml) for both fluconazole and voriconazole, and 10% of the isolates had elevated coexisting MICs (≥2 μg/ml) to two additional azoles, i.e., posaconazole and isavuconazole. In contrast to reduced amphotericin B MICs by CLSI-BMD (MIC50, 1 μg/ml) for C. auris, elevated MICs were noted by Vitek 2 (MIC50, 8 μg/ml), which were statistically significant. Candida auris remains an unnoticed pathogen in routine microbiology laboratories, as 90% of the isolates characterized by commercial identification systems are misidentified as C. haemulonii. MALDI-TOF MS proved to be a more robust diagnostic technique for rapid identification of C. auris. Considering that misleading elevated MICs of amphotericin B by the Vitek AST-YS07 card may lead to the selection of inappropriate therapy, a cautionary approach is recommended for laboratories relying on commercial systems for identification and antifungal susceptibility testing of rare yeasts.

  13. Chromogenic medium for direct susceptibility testing of Candida spp. isolated from urine.

    PubMed

    de Vasconcelos, Antônio Alexandre; Menezes, Everardo Albuquerque; Cunha, Francisco Afrânio

    2011-08-01

    Currently, there has been an increased frequency of fungal infections. Candida albicans and other Candida spp. have been proven to be major causes for urinary tract infection. Increased resistance to antifungals indicates the need to develop strategies in order to prevent the spread of resistance. Chromogenic medium have been proven to be useful in the detection of yeasts in clinical specimens containing mixed cultures of Candida. The aim of this study was to compare the results of antifungal susceptibility testing with fluconazole and amphotericin B on strains of Candida spp. isolated from urine, conducted on a Mueller-Hinton Agar with Glucose and Methylene Blue (MHAGMB) medium and on a Hicrome Candida® Agar with 2% Glucose (HCAG) medium. We used 40 samples of Candida spp. isolated from urine samples from inpatients and outpatients. The results showed that both media presented high rates of agreement, above 94%. The use of the HCAG medium decreases the release time of the results by 24-48 h, which may be decisive for initiating the correct drug treatment.

  14. Improved method for azole antifungal susceptibility testing.

    PubMed Central

    Gordon, M A; Lapa, E W; Passero, P G

    1988-01-01

    A reproducible method is described for the determination of the MICs of ketoconazole, miconazole, fluconazole, and itraconazole with sharp endpoints when employed with either yeasts or molds. A semisolid medium is used with controlled pH and standardized inoculum. The time of reading results is a critical factor in the conduct of this test. The medium is simple to prepare and has a relatively long refrigerator shelf life in a user-ready state, requiring only the addition of a freshly prepared inoculum after restoration to room temperature. Images PMID:2846651

  15. Antifungal nanoparticles and surfaces.

    PubMed

    Paulo, Cristiana S O; Vidal, Maria; Ferreira, Lino S

    2010-10-11

    Nosocomial fungal infections, an increasing healthcare concern worldwide, are often associated with medical devices. We have developed antifungal nanoparticle conjugates that can act in suspension or attach to a surface, efficiently killing fungi. For that purpose, we immobilized covalently amphotericin B (AmB), a potent antifungal agent approved by the FDA, widely used in clinical practice and effective against a large spectrum of fungi, into silica nanoparticles. These antifungal nanoparticle conjugates are fungicidal against several strains of Candida sp., mainly by contact. In addition, they can be reused up to 5 cycles without losing their activity. Our results show that the antifungal nanoparticle conjugates are more fungistatic and fungicidal than 10 nm colloidal silver. The antifungal activity of the antifungal nanoparticle conjugates is maintained when they are immobilized on a surface using a chemical adhesive formed by polydopamine. The antifungal nanocoatings have no hemolytic or cytotoxic effect against red blood cells and blood mononuclear cells, respectively. Surfaces coated with these antifungal nanoparticle conjugates can be very useful to render medical devices with antifungal properties. PMID:20845938

  16. Antibacterial and antifungal activities of crude plant extracts from Colombian biodiversity.

    PubMed

    Niño, Jaime; Mosquera, Oscar M; Correa, Yaned M

    2012-12-01

    On a global scale, people have used plants to treat diseases and infections, and this has raised interest on the plant biodiversity potencial in the search of antimicrobial principles. In this work, 75 crude n-hexanes, dichloromethane and methanol extracts from the aerial parts of 25 plants belonging to four botanical families (Asteraceae, Euphorbiaceae, Rubiaceae and Solanaceae), collected at the Natural Regional Park Ucumari (Risaralda, Colombia), were evaluated for their antibacterial and antifungal activities by the agar well diffusion method. The antibacterial activities were assayed against two Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis, and three Gram-negative ones named, Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa. In addition, the same plant extracts were tested against the yeast Candida albicans and the fungi Aspergillus fumigatus and Fusarium solani. Overall, the plant extracts examined displayed better bactericide rather than fungicide activities. In general, the best antibacterial activity was showed by the plant extracts from the Rubiaceae family, followed in order by the extracts from the Euphorbiaceae and Solanaceae ones. It is important to emphasize the great activity displayed by the methanol extract of Alchornea coelophylla (Euphorbiaceae) that inhibited four out of five bacteria tested (B. Subtilis, P. aeruginosa, S. aureus and E. coli). Furthermore, the best Minimal Inhibitory Concentration for the extracts with antifungal activities were displayed by the dichloromethane extracts from Acalypha diversifolia and Euphorbia sp (Euphorbiaceae). The most susceptible fungus evaluated was F. Solani since 60% and 20% of the dichloromethane and methanol extracts evaluated inhibited the growth of this phytopathogenic fungus. The antimicrobial activity of the different plant extracts examined in this work could be related to the secondary metabolites contents and their interaction and susceptibility of

  17. 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. PMID:24334863

  18. Antifungal and anthelmintic activities of Cleistopholis patens (Annonaceae).

    PubMed

    Akendengué, Blandine; Champy, Pierre; Nzamba, Joseph; Roblot, François; Loiseau, Philippe M; Bories, Christian

    2009-08-01

    Basic CH2Cl2 extract of the trunk bark of Cleistopholis patens (Annonaceae) exhibited antifungal activities against Candida albicans, C. parapsilosis, and C. glabrata using an agar well-diffusion assay method. Bioassay-guided fractionation of the extract led to the isolation of 8-hydroxysampangine. The methanolic extract displayed anthelmintic activity against Rhabditis pseudoelongata. Purification of the neutral CH2Cl2 extract yielded bornyl-p-transcoumarate and bornyl-p-cis-coumarate.

  19. Antifungal activity of tuberose absolute and some of its constituents.

    PubMed

    Nidiry, Eugene Sebastian J; Babu, C S Bujji

    2005-05-01

    The antifungal activity of the absolute of tuberose (Polianthes tuberosa ) and some of its constituents were evaluated against the mycelial growth of Colletotrichum gloeosporioides on potato-dextrose-agar medium. Tuberose absolute showed only mild activity at a concentration of 500 mg/L. However, three constituents present in the absolute, namely geraniol, indole and methyl anthranilate exhibited significant activity showing total inhibition of the mycelial growth at this concentration.

  20. Antifungal effect and mechanism of garlic oil on Penicillium funiculosum.

    PubMed

    Li, Wen-Ru; Shi, Qing-Shan; Liang, Qing; Huang, Xiao-Mo; Chen, Yi-Ben

    2014-10-01

    Garlic oil is a kind of fungicide, but little is known about its antifungal effects and mechanism. In this study, the chemical constituents, antifungal activity, and effects of garlic oil were studied with Penicillium funiculosum as a model strain. Results showed that the minimum fungicidal concentrations (MFCs, v/v) were 0.125 and 0.0313 % in agar medium and broth medium, respectively, suggesting that the garlic oil had a strong antifungal activity. The main ingredients of garlic oil were identified as sulfides, mainly including disulfides (36 %), trisulfides (32 %) and monosulfides (29 %) by gas chromatograph-mass spectrometer (GC/MS), which were estimated as the dominant antifungal factors. The observation results by transmission electron microscope (TEM) and scanning electron microscope (SEM) indicated that garlic oil could firstly penetrate into hyphae cells and even their organelles, and then destroy the cellular structure, finally leading to the leakage of both cytoplasm and macromolecules. Further proteomic analysis displayed garlic oil was able to induce a stimulated or weakened expression of some key proteins for physiological metabolism. Therefore, our study proved that garlic oil can work multiple sites of the hyphae of P. funiculosum to cause their death. The high antifungal effects of garlic oil makes it a broad application prospect in antifungal industries.

  1. Agar polysaccharides from Gracilaria species (Rhodophyta, Gracilariaceae).

    PubMed

    Marinho-Soriano, E

    2001-07-26

    Yield, physical and chemical properties of agar from three agarophytes species (Gracilaria gracilis, G. dura and G. bursa-pastoris) were determined. The agar yield from the three species varied significantly (P<0.01). The highest yields of agar (34.8%) and the lowest (30%) were obtained from G. bursa-pastoris and G. gracilis, respectively. Highest gel strength (630+/-15 g cm(-2)) was obtained from agar extracted from G. gracilis and lowest from G. bursa-pastoris (26+/-3.6 g cm(-2)). The values of 3,6-anhydrogalactose were similar for G. gracilis and G. dura and there were no significant differences among the species. The sulfate contents varied significantly (P<0.01) and the higher value was obtained from G. bursa-pastoris. Among the three species, G. gracilis showed superior agar quality than the other two species, hence it can be considered a good potential source for industrial use.

  2. Comparison of antifungal activities of Vietnamese citrus essential oils.

    PubMed

    Van Hung, Pham; Chi, Pham Thi Lan; Phi, Nguyen Thi Lan

    2013-03-01

    Citrus essential oils (EOs) are volatile compounds from citrus peels and widely used in perfumes, cosmetics, soaps and aromatherapy. In this study, inhibition of citrus EOs extracted from Vietnamese orange (Citrus sinensis), mandarin (Citrus reticulata Blanco), pomelo (Citrus grandis Osbeck) and lime (Citrus aurantifolia Swingle) on the growth of plant pathogenic fungi, Mucor hiemalis, Penicillium expansum and Fusarium proliferatum was investigated. The EOs of the citrus peels were obtained by cold-pressing method and the antifungal activity of EOs was evaluated using the agar dilution method. The results show that the EOs had significant antifungal activity. Lime EO was the best inhibitor of M. hiemalis and F. proliferatum while pomelo EO was the most effective against P. expansum. These results indicate that citrus EOs can be used as antifungal natural products in the food, pharmaceutical and cosmetic industries.

  3. In vitro antifungal effect of human milk.

    PubMed

    Mete, Emin; Bavbek, Nüket; Dayi, Sabriye; Erkmen, Mehtap; Andiran, Fatih

    2006-01-01

    A lower incidence of infection occurs among breast-fed babies because of the presence of antibacterial, antiviral, and antiparasitic effects, but little is known about the antifungal effects to fungi other than Candida albicans. This study was undertaken to assess the antifungal effect of human milk to the fungi in the environmental air, which also may be allergenic. Milk samples were obtained from lactating mothers of healthy term infants between the 3rd and 8th days of lactation. Ninety-six Sabouraud agar petri dishes were separated into three groups, closed, and incubated in the same location after 15 minutes uncovered. The first group (group 1, n=48 dishes) was used to detect the fungal flora of the environmental air. The second group (group 2, n=24 dishes) was rubbed with a thin layer of human milk by a sterile pipette. The last group (group 3, n=24 dishes) was rubbed with 0.9% NaCIlsolution. After 7 days of incubation, the colony-forming fungal growths of all dishes were evaluated by a microbiologist who did not know the groups of the dishes. The number offungal colonies grown in human milk-rubbed dishes in group 2 was less than both of the other groups (group 1 and 3; p < 0.001 and p < 0.001, respectively). These results indicated that human milk may have antifungal effects to fungi present in the environmental air as tested by Sabouraud agar petri dishes. To prevent infections and allergic diseases, human milk must be considered the ideal food for newborns. PMID:17063672

  4. Evaluation of an automated agar plate streaker.

    PubMed Central

    Tilton, R C; Ryan, R W

    1978-01-01

    An automated agar plate streaker was evaluated. The Autostreaker mechanizes the agar plate streaking process by providing storage for plates, labeling and streaking one or more plates for either isolation or quantitation, and stacking in one of several racks for subsequent incubation. Results showed the Autostreaker to produce agar plates with well-separated colonies and accurate colony counts. A total of 1,930 clinical specimens were processed either in parallel with manual methods or solely by the Autostreaker. Technologist acceptance of machine-streaked plates was outstanding. Images PMID:348722

  5. Comparison of echinocandin antifungals

    PubMed Central

    Eschenauer, Gregory; DePestel, Daryl D; Carver, Peggy L

    2007-01-01

    The incidence of invasive fungal infections, especially those due to Aspergillus spp. and Candida spp., continues to increase. Despite advances in medical practice, the associated mortality from these infections continues to be substantial. The echinocandin antifungals provide clinicians with another treatment option for serious fungal infections. These agents possess a completely novel mechanism of action, are relatively well-tolerated, and have a low potential for serious drug–drug interactions. At the present time, the echinocandins are an option for the treatment of infections due Candida spp (such as esophageal candidiasis, invasive candidiasis, and candidemia). In addition, caspofungin is a viable option for the treatment of refractory aspergillosis. Although micafungin is not Food and Drug Administration-approved for this indication, recent data suggests that it may also be effective. Finally, caspofungin- or micafungin-containing combination therapy should be a consideration for the treatment of severe infections due to Aspergillus spp. Although the echinocandins share many common properties, data regarding their differences are emerging at a rapid pace. Anidulafungin exhibits a unique pharmacokinetic profile, and limited cases have shown a potential far activity in isolates with increased minimum inhibitory concentrations to caspofungin and micafungin. Caspofungin appears to have a slightly higher incidence of side effects and potential for drug–drug interactions. This, combined with some evidence of decreasing susceptibility among some strains of Candida, may lessen its future utility. However, one must take these findings in the context of substantially more data and use with caspofungin compared with the other agents. Micafungin appears to be very similar to caspofungin, with very few obvious differences between the two agents. PMID:18360617

  6. Some Experiments With Agar-Grown Seedlings

    ERIC Educational Resources Information Center

    Freeland, P. W.

    1973-01-01

    Two percent agar gel is reported as a better medium for germination and growth studies. Students can be encouraged to undertake many simple experiments and make precise observations by using this medium. (PS)

  7. Characterization of physicochemical properties of carboxymethyl agar.

    PubMed

    Cao, Mingzhao; Liu, Xin; Luan, Jimei; Zhang, Xiaodong

    2014-10-13

    A series of carboxymethyl agars (CMAs) with different degree of substitution (DS) were prepared, and their properties were determined and analyzed. The results showed that with the increase of DS, the dissolving temperature, the gelling temperature, the gel melting temperature, the gel strength, the gel hardness, the gel fracturability, and the solution apparent viscosity of CMA all decreased, except that its gel cohesiveness and gel springiness increased. The variation process of agar molecules in solution from coil to helix could be observed by measuring the optical rotation of the solution at such a low concentration, at which even the solution could not form a gel. The gel skeleton microstructures of both agar and CMA were of porous network structure, and the pore size of CMA became smaller and denser with the increase of its DS. After carboxymethylation, the agar hygroscopicity was improved, but its thermal stability was lowered.

  8. Development of a novel in vitro onychomycosis model for the evaluation of topical antifungal activity.

    PubMed

    Sleven, Reindert; Lanckacker, Ellen; Boulet, Gaëlle; Delputte, Peter; Maes, Louis; Cos, Paul

    2015-05-01

    A novel in vitro onychomycosis model was developed to easily predict the topical activity potential of novel antifungal drugs. The model encompasses drug activity and diffusion through bovine hoof slices in a single experimental set-up. Results correspond well with the antifungal susceptibility assay and Franz cell diffusion test.

  9. Antifungal compounds from cyanobacteria.

    PubMed

    Shishido, Tânia K; Humisto, Anu; Jokela, Jouni; Liu, Liwei; Wahlsten, Matti; Tamrakar, Anisha; Fewer, David P; Permi, Perttu; Andreote, Ana P D; Fiore, Marli F; Sivonen, Kaarina

    2015-04-13

    Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders.

  10. Antifungal Compounds from Cyanobacteria

    PubMed Central

    Shishido, Tânia K.; Humisto, Anu; Jokela, Jouni; Liu, Liwei; Wahlsten, Matti; Tamrakar, Anisha; Fewer, David P.; Permi, Perttu; Andreote, Ana P. D.; Fiore, Marli F.; Sivonen, Kaarina

    2015-01-01

    Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders. PMID:25871291

  11. Agar agar-stabilized milled zerovalent iron particles for in situ groundwater remediation.

    PubMed

    Velimirovic, Milica; Schmid, Doris; Wagner, Stephan; Micić, Vesna; von der Kammer, Frank; Hofmann, Thilo

    2016-09-01

    Submicron-scale milled zerovalent iron (milled ZVI) particles produced by grinding macroscopic raw materials could provide a cost-effective alternative to nanoscale zerovalent iron (nZVI) particles for in situ degradation of chlorinated aliphatic hydrocarbons in groundwater. However, the aggregation and settling of bare milled ZVI particles from suspension presents a significant obstacle to their in situ application for groundwater remediation. In our investigations we reduced the rapid aggregation and settling rate of bare milled ZVI particles from suspension by stabilization with a "green" agar agar polymer. The transport potential of stabilized milled ZVI particle suspensions in a diverse array of natural heterogeneous porous media was evaluated in a series of well-controlled laboratory column experiments. The impact of agar agar on trichloroethene (TCE) removal by milled ZVI particles was assessed in laboratory-scale batch reactors. The use of agar agar significantly enhanced the transport of milled ZVI particles in all of the investigated porous media. Reactivity tests showed that the agar agar-stabilized milled ZVI particles were reactive towards TCE, but that their reactivity was an order of magnitude less than that of bare, non-stabilized milled ZVI particles. Our results suggest that milled ZVI particles could be used as an alternative to nZVI particles as their potential for emplacement into contaminated zone, their reactivity, and expected longevity are beneficial for in situ groundwater remediation.

  12. Standard operating procedure to prepare agar phantoms

    NASA Astrophysics Data System (ADS)

    Souza, R. M.; Santos, T. Q.; Oliveira, D. P.; Souza, R. M.; Alvarenga, A. V.; Costa-Felix, R. P. B.

    2016-07-01

    Agar phantoms are widely used as soft tissue mimics and some preparation techniques are described in the literature. There are also standards that describe the recipe of a soft tissue mimicking material (TMM). However some details of manufacture process are not clearly defined. The standardization of the phantom's preparation can produce a metrological impact on the results of the acoustic properties measured. In this direction, this paper presents a standard operating procedure (SOP) to prepare the agar TMM described on the IEC 60601-237.

  13. 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

  14. [Laboratory-based evaluation of a selective X-SA agar medium supplemented with chromogenic substrate for Staphylococcus aureus].

    PubMed

    Nakasone, Isamu; Yamane, Nobuhisa

    2005-01-01

    The newly developed culture medium, X-SA agar medium (Nissui Pharmaceuticals Co., Ltd., Tokyo) selective for Staphylococcus aureus was evaluated for its ability to detect clinical isolates of S. aureus. Besides S. aureus, X-SA agar media allowed the growth of coagulase-negative staphylococci, Bacillus cereus and some isolates of corynebacteria. However, those species were easily distinguishable from the blue and convex colonies of S. aureus. When compared to the traditional egg yolk mannitol salt agar, selectivity for the species other than S. aureus was more specific, and growth support for S. aureus was more comparable to sheep blood agar. Also, when various phenotypic variants of S. aureus were inoculated, visible colonies of mucoid colony variants and attenuated growth variants on Mueller-Hinton agar appeared on X-SA agar plates after 24 hour-incubation, but it required 48 hour-incubation for small colony variants. The fully automated microbiology system, RAISUS (Nissui Pharmaceuticals Co., Ltd.) gave comparable species-identification and antimicrobial susceptibility test results when cell suspension directly prepared from X-SA agar media was tested. However, species-identification for phenotypic variants of S. aureus was more complicated for RAISUS testing and detection of coagulase. With these results, it could be concluded that the X-SA agar medium supplemented with chromogenic substrate is superior to the traditional selective media for the detection of S. aureus, and is widely applicable for clinical microbiology as well as food microbiology.

  15. Experimental evaluation of antifungal and antiseptic agents against Rhodotorula spp.

    PubMed

    Preney, L; Théraud, M; Guiguen, C; Gangneux, J P

    2003-12-01

    We studied the susceptibility of 21 strains of Rhodotorula rubra and nine strains of R. glutinis to eight antifungals and tested eight antiseptic agents on one strain of R. rubra. The tested strains were susceptible to ketoconazole, 5-fluorocytosine, amphotericin B, and nystatin, intermediate to econazole and resistant to fluconazole, itraconazole and miconazole. After 5-min contact, six of the eight antiseptic agents tested showed a fungicidal activity on the tested R. rubra strain.

  16. Use of agar agar stabilized milled zero-valent iron particles for in situ groundwater remediation

    NASA Astrophysics Data System (ADS)

    Schmid, Doris; Velimirović, Milica; Wagner, Stephan; Micić Batka, Vesna; von der Kammer, Frank; Hofmann, Thilo

    2015-04-01

    A major obstacle for use of nanoscale zero-valent iron (nZVI) particles as a nontoxic material for effective in situ degradation of chlorinated aliphatic hydrocarbons (CAHs) is the high production cost. For that reason, submicro-scale milled zero-valent iron particles were recently developed (milled ZVI, UVR-FIA, Germany) by grinding macroscopic raw materials of elementary iron as a cheaper alternative to products produced by solid-state reduction. However, milled ZVI particles tend to aggregate and due to the rather large particle size (d50= 11.9 µm) also rapidly sediment. To prevent aggregation and consequently sedimentation of milled ZVI particles and therefore improve the mobility after in situ application, the use of a stabilizer is considered in literature as a most promising option. In this study, milled ZVI particles (1 g L-1 of particle concentration) were stabilized by environmentally friendly polymer agar agar (>0.5 g L-1), which had a positive impact on the milled ZVI stability. Sedimentation rate was significantly decreased by increasing the suspension viscosity. Column transport experiments were performed for bare and agar agar stabilized milled ZVI particles in commercially available fine grained quartz sand (DORSILIT® Nr.8, Gebrüder Dorfner GmbH Co, Germany) and different porous media collected from brownfields. The experiments were carried out under field relevant injection conditions of 100 m d-1. The maximal travel distance (LT) of less than 10 cm was determined for non-stabilized suspension in fine grained quartz sand, while agar agar (1 g L-1) stabilized milled ZVI suspension revealed LT of 12 m. Similar results were observed for porous media from brownfields showing that mobility of agar agar stabilized particle suspensions was significantly improved compared to bare particles. Based on the mobility data, agar agar stabilized milled zero-valent iron particles could be used for in situ application. Finally, lab-scale batch degradation

  17. Luminescent DNA- and agar-based membranes.

    PubMed

    Leones, R; Fernandes, M; Ferreira, R A S; Cesarino, I; Lima, J F; Carlos, L D; Bermudez, V de Zea; Magon, C J; Donoso, J P; Silva, M M; Pawlicka, A

    2014-09-01

    Luminescent materials containing europium ions are investigated for different optical applications. They can be obtained using bio-macromolecules, which are promising alternatives to synthetic polymers based on the decreasing oil resources. This paper describes studies of the DNA- and Agar-europium triflate luminescent membranes and its potential technological applications are expanded to electroluminescent devices. Polarized optical microscopy demonstrated that the samples are birefringent with submicrometer anisotropy. The X-ray diffraction analysis revealed predominantly amorphous nature of the samples and the atomic force microscopy images showed a roughness of the membranes of 409.0 and 136.1 nm for the samples of DNA10Eu and Agar1.11Eu, respectively. The electron paramagnetic resonance spectra of the DNA(n)Eu membranes with the principal lines at g ≈ 2.0 and g ≈ 4.8 confirmed uniform distribution of rare earth ions in a disordered matrix. Moreover, these strong and narrow resonance lines for the samples of DNA(n)Eu when compared to the Agar(n)Eu suggested a presence of paramagnetic radicals arising from the DNA matrix. The emission spectra suggested that the Eu3+ ions occupy a single local environment in both matrices and the excitation spectra monitored around the Eu emission lines pointed out that the Eu3+ ions in the Agar host were mainly excited via the broad band component rather than by direct intra-4f(6) excitation, whereas the opposite case occurred for the DNA-based sample.

  18. Antifungal activity of Mexican oregano (Lippia berlandieri Shauer).

    PubMed

    Portillo-Ruiz, Martha Cristina; Viramontes-Ramos, Sabina; Muñoz-Castellanos, Laila Nayzzel; Gastélum-Franco, María Guadalupe; Nevárez-Moorillón, Guadalupe Virginia

    2005-12-01

    Antifungal and sensorial properties of spices have been recognized for years. The antifungal compounds are products of the plant's secondary metabolism, and the action of those compounds could be used to inhibit the growth of spoilage and pathogenic microorganisms in food. Mexican oregano (Lippia berlandieri) grows wildly in the desert zone of Mexico and is usually added to regional foods. The goal of this study was to evaluate the antifungal activity of Mexican oregano versus food-contaminant fungi. Fungi were isolated from spoiled fruit and vegetables and identified according to morphological characteristics. The antifungal activity of oregano was evaluated by radial growth measurement on potato dextrose agar added with dried oregano (0.25 to 4.0%). The essential oil antifungal activity of oregano was also evaluated by the diffusion well test. Twenty-one fungal strains were isolated, which included Penicillium, Geotrichum, Aspergillus, and Bipolaris. In seven of the 21 strains, no inhibitory effect was observed at either concentration of oregano. An increase in growth at the lower or higher concentrations of oregano, when compared to the control, was observed in two fungal strains; in 12 strains, a strong inhibitory effect of oregano was evident. The oregano essential oil was inhibitory to all fungal strains, but there were differences in the extent of the effect. Although the antifungal effect of oregano is strongly established, there was a differential effect with the fungal strains studied. Besides pathogenic fungi and bacteria, microbial spoilage flora should be considered when the addition of spices for food preservation is proposed. PMID:16355848

  19. Antifungal activity of diethyldithiocarbamate.

    PubMed

    Allerberger, F; Reisinger, E C; Söldner, B; Dierich, M P

    1989-10-01

    Sodium diethyldithiocarbamate (DTC) was evaluated for its ability to combat four different species of fungi in vitro. Using a microtiter-broth-dilution method we were able to demonstrate an antifungal activity against Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus and Mucor mucedo in doses achievable by intravenous administration in man.

  20. The Soft Agar Colony Formation Assay

    PubMed Central

    Borowicz, Stanley; Van Scoyk, Michelle; Avasarala, Sreedevi; Karuppusamy Rathinam, Manoj Kumar; Tauler, Jordi; Bikkavilli, Rama Kamesh; Winn, Robert A.

    2014-01-01

    Anchorage-independent growth is the ability of transformed cells to grow independently of a solid surface, and is a hallmark of carcinogenesis. The soft agar colony formation assay is a well-established method for characterizing this capability in vitro and is considered to be one of the most stringent tests for malignant transformation in cells. This assay also allows for semi-quantitative evaluation of this capability in response to various treatment conditions. Here, we will demonstrate the soft agar colony formation assay using a murine lung carcinoma cell line, CMT167, to demonstrate the tumor suppressive effects of two members of the Wnt signaling pathway, Wnt7A and Frizzled-9 (Fzd-9). Concurrent overexpression of Wnt7a and Fzd-9 caused an inhibition of colony formation in CMT167 cells. This shows that expression of Wnt7a ligand and its Frizzled-9 receptor is sufficient to suppress tumor growth in a murine lung carcinoma model. PMID:25408172

  1. Luminescent DNA- and agar-based membranes.

    PubMed

    Leones, R; Fernandes, M; Ferreira, R A S; Cesarino, I; Lima, J F; Carlos, L D; Bermudez, V de Zea; Magon, C J; Donoso, J P; Silva, M M; Pawlicka, A

    2014-09-01

    Luminescent materials containing europium ions are investigated for different optical applications. They can be obtained using bio-macromolecules, which are promising alternatives to synthetic polymers based on the decreasing oil resources. This paper describes studies of the DNA- and Agar-europium triflate luminescent membranes and its potential technological applications are expanded to electroluminescent devices. Polarized optical microscopy demonstrated that the samples are birefringent with submicrometer anisotropy. The X-ray diffraction analysis revealed predominantly amorphous nature of the samples and the atomic force microscopy images showed a roughness of the membranes of 409.0 and 136.1 nm for the samples of DNA10Eu and Agar1.11Eu, respectively. The electron paramagnetic resonance spectra of the DNA(n)Eu membranes with the principal lines at g ≈ 2.0 and g ≈ 4.8 confirmed uniform distribution of rare earth ions in a disordered matrix. Moreover, these strong and narrow resonance lines for the samples of DNA(n)Eu when compared to the Agar(n)Eu suggested a presence of paramagnetic radicals arising from the DNA matrix. The emission spectra suggested that the Eu3+ ions occupy a single local environment in both matrices and the excitation spectra monitored around the Eu emission lines pointed out that the Eu3+ ions in the Agar host were mainly excited via the broad band component rather than by direct intra-4f(6) excitation, whereas the opposite case occurred for the DNA-based sample. PMID:25924317

  2. Susceptibility Testing and Molecular Classification of Paecilomyces spp.▿

    PubMed Central

    Castelli, Maria Victoria; Alastruey-Izquierdo, Ana; Cuesta, Isabel; Monzon, Araceli; Mellado, Emilia; Rodriguez-Tudela, Juan L.; Cuenca-Estrella, Manuel

    2008-01-01

    In vitro susceptibility profiles of 58 Paecilomyces clinical isolates are reported. Amphotericin B, itraconazole, and echinocandins showed poor activity against Paecilomyces lilacinus, while the new triazoles were active against it. Paecilomyces variotii exhibited a different susceptibility pattern, being susceptible to most antifungal agents apart from voriconazole and ravuconazole. PMID:18519716

  3. The calcineurin inhibitor cyclosporin A exhibits synergism with antifungals against Candida parapsilosis species complex.

    PubMed

    Cordeiro, Rossana de Aguiar; Macedo, Ramila de Brito; Teixeira, Carlos Eduardo Cordeiro; Marques, Francisca Jakelyne de Farias; Bandeira, Tereza de Jesus Pinheiro Gomes; Moreira, José Luciano Bezerra; Brilhante, Raimunda Sâmia Nogueira; Rocha, Marcos Fábio Gadelha; Sidrim, José Júlio Costa

    2014-07-01

    Candida parapsilosis complex comprises three closely related species, C. parapsilosis sensu stricto, Candida metapsilosis and Candida orthopsilosis. In the last decade, antifungal resistance to azoles and caspofungin among C. parapsilosis sensu lato strains has been considered a matter of concern worldwide. In the present study, we evaluated the synergistic potential of antifungals and the calcineurin inhibitor cyclosporin A (Cys) against planktonic and biofilms of C. parapsilosis complex from clinical sources. Susceptibility assays with amphotericin, fluconazole, voriconazole, caspofungin and Cys were performed by microdilution in accordance with Clinical and Laboratory Standards Institute guidelines. Synergy testing against planktonic cells of C. parapsilosis sensu lato strains was assessed by the chequerboard method. Combinations formed by antifungals with Cys were evaluated against mature biofilms in microtitre plates. No differences in the antifungal susceptibility pattern among species were observed, but C. parapsilosis sensu stricto strains were more susceptible to Cys than C. orthopsilosis and C. metapsilosis. Synergism between antifungals and Cys was observed in C. parapsilosis sensu lato strains. Combinations formed by antifungals and Cys were able to prevent biofilm formation and showed an inhibitory effect against mature biofilms of C. parapsilosis sensu stricto, C. metapsilosis and C. orthopsilosis. These results strengthen the potential of calcineurin inhibition as a promising approach to enhance the efficiency of antifungal drugs. PMID:24722799

  4. Antifungal activity of Lactobacillus paracasei ssp. tolerans isolated from a sourdough bread culture.

    PubMed

    Hassan, Yousef I; Bullerman, Lloyd B

    2008-01-15

    Lactic acid bacteria were isolated from four different sourdough bread cultures previously investigated for antifungal activity. A total of 116 isolates were obtained and screened for antifungal activity against a battery of molds. The most inhibitory isolate obtained was identified by API 50 CHL and 16s ribosomal RNA genotyping and found to be Lactobacillus paracasei ssp. tolerans. This isolate completely inhibited the growth of Fusarium proliferatum M 5689, M 5991 and Fusarium graminearum R 4053 compared to controls in a dual agar plate assay.

  5. In Vitro Antifungal Activities against Moulds Isolated from Dermatological Specimens

    PubMed Central

    Mohd Nizam, Tzar; Binting, Rabiatul Adawiyah AG.; Mohd Saari, Shafika; Kumar, Thivyananthini Vijaya; Muhammad, Marianayati; Satim, Hartini; Yusoff, Hamidah; Santhanam, Jacinta

    2016-01-01

    Background This study aimed to determine the minimum inhibitory concentrations (MICs) of various antifungal agents against moulds isolated from dermatological specimens. Methods We identified 29 moulds from dermatological specimens between October 2012 and March 2013 by conventional methods. We performed antifungal susceptibility testing on six antifungal agents, amphotericin B, clotrimazole, itraconazole, ketoconazole, miconazole and terbinafine, according to the Clinical and Laboratory Standards Institute guidelines contained in the M38-A2 document. Results Most antifungal agents were active against the dermatophytes, except for terbinafine against Trichophyton rubrum (geometric mean MIC, MICGM 3.17 μg/mL). The dematiaceous moulds were relatively susceptible to amphotericin B and azoles (MICGM 0.17–0.34 μg/mL), but not to terbinafine (MICGM 3.62 μg/mL). Septate hyaline moulds showed variable results between the relatively more susceptible Aspergillus spp. (MICGM 0.25–4 μg/mL) and the more resistant Fusarium spp. (MICGM 5.66–32 μg/mL). The zygomycetes were susceptible to amphotericin B (MICGM 0.5 μg/mL) and clotrimazole (MICGM 0.08 μg/mL), but not to other azoles (MICGM 2.52–4 μg/mL). Conclusion Amphotericin B and clotrimazole were the most effective antifungal agents against all moulds excepting Fusarium spp., while terbinafine was useful against dermatophytes (except T. rubrum) and Aspergillus spp. However, a larger study is required to draw more solid conclusions. PMID:27418867

  6. Comparison of recovery of airborne microorganisms in a dairy cattle facility using selective agar and thin agar layer resuscitation media.

    PubMed

    Crozier-Dodson, Beth Ann; Fung, Daniel Y C

    2002-09-01

    Thin agar layer (TAL) medium was developed at Kansas State University to improve the resuscitation of injured cells and has been shown to result in higher recovery than is obtained with selective media alone for cold-, heat-, salt-, and acid-injured cells. The experiment presented here was designed to determine the effectiveness of the TAL method for the recovery of possibly injured organisms from air. Eleven agar media were used for the experiment: tryptic soy agar (TSA), MacConkey sorbitol agar (MSA), TAL-MSA, Baird-Parker (BP) agar, TAL-BP agar, modified Oxford (MOX) agar, TAL-MOX agar, xylose lysine sodium desoxycholate (XLD) agar, TAL-XLD agar, Yersinia-selective (CIN) agar, and TAL-CIN agar. The TAL plates were prepared by pipetting 6 ml of selective agar into a BBL Rodac plate (65 by 15 mm). Selective agar was allowed to solidify, and then each plate was overlaid with 6 ml of TSA. Selective agar plates were prepared by pipetting 12 ml of agar into BBL Rodac plates and allowing the agar to solidify. Samples were taken at an indoor cattle facility at five separate locations with a BioScience SAS air-sampling instrument. For each plate, 60 liters of air was sampled. Three replications of the experiment were performed. The TAL method resulted in higher counts of microorganisms on all media tested. In addition, 175 isolates were selected randomly and identified in order to test the selectivity of TAL and the selective media for target organisms. The data obtained in this study show that the TAL resuscitation method is effective and necessary for the recovery of airborne organisms that may be injured.

  7. Evaluation of the chromogenic agar chromID C. difficile.

    PubMed

    Eckert, Catherine; Burghoffer, Béatrice; Lalande, Valérie; Barbut, Frederic

    2013-03-01

    Three selective media (chromID C. difficile agar, taurocholate cycloserine cefoxitin agar [TCCA; homemade], and CLO medium) were compared from 406 stool samples of patients suspected of having Clostridium difficile infection. The sensitivities of chromID C. difficile agar at 24 h and 48 h, CLO medium, and TCCA were 74.1%, 87%, 85.2%, and 70.4%, respectively.

  8. Antifungal activity of alkyl gallates against plant pathogenic fungi.

    PubMed

    Ito, Shinsaku; Nakagawa, Yasutaka; Yazawa, Satoru; Sasaki, Yasuyuki; Yajima, Shunsuke

    2014-04-01

    The antifungal activity of alkyl gallates against plant pathogenic fungi was evaluated. All of the fungi tested in this study were susceptible to some alkyl gallates, and the effect of linear alkyl gallates against plant pathogenic fungi was similar to the previously reported effects against Gram-negative and Gram-positive bacteria. We found that branched alkyl gallates showed stronger activity than did linear alkyl gallates with similar logP values. In addition, the antifungal activity of alkyl gallates was correlated with gallate-induced inhibition of the activity of mitochondrial complex II. The antifungal activity of alkyl gallates likely originates, at least in part, from their ability to inhibit the membrane respiratory chain.

  9. Antifungal drug resistance among Candida species: mechanisms and clinical impact.

    PubMed

    Sanguinetti, Maurizio; Posteraro, Brunella; Lass-Flörl, Cornelia

    2015-06-01

    The epidemiology of Candida infections has changed in recent years. Although Candida albicans is still the main cause of invasive candidiasis in most clinical settings, a substantial proportion of patients is now infected with non-albicans Candida species. The various Candida species vary in their susceptibility to the most commonly used antifungal agents, and the intrinsic resistance to antifungal therapy seen in some species, along with the development of acquired resistance during treatment in others, is becoming a major problem in the management of Candida infection. A better understanding of the mechanisms and clinical impact of antifungal drug resistance is essential for the efficient treatment of patients with Candida infection and for improving treatment outcomes. Herein, we report resistance to the azoles and echinocandins among Candida species.

  10. Syneresis and delayed detachment in agar plates

    NASA Astrophysics Data System (ADS)

    Divoux, Thibaut; Mao, Bosi; Snabre, Patrick

    Biogels made of crosslinked polymers such as proteins or polysaccharides behave as porous soft solids and store large amount of solvent. These gels undergo spontaneous aging, called syneresis that consists in the shrinkage of the gel matrix and the progressive expulsion of the solvent. As a result, a biogel originally casted in a container often lose contact with the container sidewalls, and the detachment time is a priori difficult to anticipate since it may occur over variable time spans (from hours to days). Here we report on the syneresis phenomena in agar plates that consist in Petri dishes filled with a gel mainly composed of agar. Direct observations and speckle pattern correlation analysis allow us to rationalize the delayed detachment of the gel from the sidewall of the Petri dish. The detachment time $t^*$ is surprisingly not controlled by the mass loss as one would intuitively expect. Instead, $t^*$ is strongly correlated to the gel minimum thickness $e_{min}$ measured along the sidewall of the plate, and increases as a robust function of $e_{min}$ independently of the prior mass-loss history. Time-resolved correlation spectroscopy atypically applied to such weakly diffusive media gives access to the local thinning rate of the gel. This technique also allows us to detect the gel micro-displacements that are triggered by the water evaporation prior to the detachment, and even to anticipate the latter from a few hours. Our work provides observables to predict the detachment time of agar gels in dishes, and highlights the relevance of speckle pattern correlation analysis for the quantitative investigation of the syneresis dynamics in biopolymer gels.

  11. Syneresis and delayed detachment in agar plates.

    PubMed

    Divoux, Thibaut; Mao, Bosi; Snabre, Patrick

    2015-05-14

    Biogels made of crosslinked polymers such as proteins or polysaccharides behave as porous soft solids and store large amounts of solvent. These gels undergo spontaneous aging, called syneresis, which consists of the shrinkage of the gel matrix and the progressive expulsion of solvent. As a result, a biogel originally casted in a container often loses contact with the container sidewalls, and the detachment time is difficult to anticipate a priori, since it may occur over variable time spans (from hours to days). Here we report on syneresis phenomena in agar plates, which consist of Petri dishes filled with a gel mainly composed of agar. Direct observations and speckle pattern correlation analysis allow us to rationalize the delayed detachment of the gel from the sidewall of the Petri dish. The detachment time t* is surprisingly not controlled by the mass loss as one would intuitively expect. Instead, t* is strongly correlated to the gel minimum thickness emin measured along the sidewall of the plate, and increases as a robust function of emin, independently of the prior mass-loss history. Time-resolved correlation spectroscopy atypically applied to such weakly diffusive media gives access to the local thinning rate of the gel. This technique also allows us to detect the gel micro-displacements that are triggered by water evaporation prior to the detachment, and even to anticipate the latter from a few hours. Our work provides observables to predict the detachment time of agar gels in dishes, and highlights the relevance of speckle pattern correlation analysis for the quantitative investigation of the syneresis dynamics in biopolymer gels.

  12. Syneresis and delayed detachment in agar plates.

    PubMed

    Divoux, Thibaut; Mao, Bosi; Snabre, Patrick

    2015-05-14

    Biogels made of crosslinked polymers such as proteins or polysaccharides behave as porous soft solids and store large amounts of solvent. These gels undergo spontaneous aging, called syneresis, which consists of the shrinkage of the gel matrix and the progressive expulsion of solvent. As a result, a biogel originally casted in a container often loses contact with the container sidewalls, and the detachment time is difficult to anticipate a priori, since it may occur over variable time spans (from hours to days). Here we report on syneresis phenomena in agar plates, which consist of Petri dishes filled with a gel mainly composed of agar. Direct observations and speckle pattern correlation analysis allow us to rationalize the delayed detachment of the gel from the sidewall of the Petri dish. The detachment time t* is surprisingly not controlled by the mass loss as one would intuitively expect. Instead, t* is strongly correlated to the gel minimum thickness emin measured along the sidewall of the plate, and increases as a robust function of emin, independently of the prior mass-loss history. Time-resolved correlation spectroscopy atypically applied to such weakly diffusive media gives access to the local thinning rate of the gel. This technique also allows us to detect the gel micro-displacements that are triggered by water evaporation prior to the detachment, and even to anticipate the latter from a few hours. Our work provides observables to predict the detachment time of agar gels in dishes, and highlights the relevance of speckle pattern correlation analysis for the quantitative investigation of the syneresis dynamics in biopolymer gels. PMID:25812667

  13. Characteristic features and dye degrading capability of agar-agar gel immobilized manganese peroxidase.

    PubMed

    Bilal, Muhammad; Asgher, Muhammad; Shahid, Muhammad; Bhatti, Haq Nawaz

    2016-05-01

    Immobilization of enzymes has been regarded as an efficient approach to develop biocatalyst with improved activity and stability characteristics under reaction conditions. In the present study, purified manganese peroxidase (MnP) from Ganoderma lucidum IBL-05 was immobilized in agar-agar support using entrapment technique. Maximum immobilization yield was accomplished at 4.0% agar-agar gel. The immobilized MnP exhibited better resistance to changes in pH and temperature than the free enzyme, with optimal conditions being pH 6.0 and 50 °C. The kinetic parameters Km and Kcat/Km for free and entrapped MnP were calculated to be 65.6 mM and 6.99 M(-1) s(-1), and 82 mM and 8.15 M(-1) s(-1), respectively. Thermo-stability was significantly improved after immobilization. After 120 h, the insolubilized MnP retained its activity up to 71.9% and 60.3% at 30 °C and 40 °C, respectively. It showed activity until 10th cycle and retained 74.3% residual activity after 3th cycle. The effects of H2O2, ionic strength and potential inhibitors on activity of free and immobilized enzyme were investigated. Moreover, the decolorization of three structurally different dyes was monitored in order to assess the degrading capability of the entrapped MnP. The decolorization efficiencies for all the tested dyes were 78.6-84.7% after 12h. The studies concluded that the toxicity of dyes aqueous solutions was significantly reduced after treatment. The remarkable catalytic, thermo-stability and re-cycling features of the agar-agar immobilized MnP display a high potential for biotechnological applications. PMID:26854887

  14. 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

  15. Biological treatment of textile dyes by agar-agar immobilized consortium in a packed bed reactor.

    PubMed

    Patel, Yogesh; Gupte, Akshaya

    2015-03-01

    The decolorization of Acid Maroon V was investigated using bacterial consortium EDPA containing Enterobacter dissolvens AGYP1 and Pseudomonas aeruginosa AGYP2 immobilized in different entrapment matrices. The consortium displayed 96% removal of dye (100 mg/l) within 6 h when immobilized in agar-agar. Under optimum concentrations of agar-agar (3.0% w/v) and cell biomass (0.9 g% w/v), the consortium displayed decolorization for 18 successive batches of Acid Maroon V and also decolorized 14 other different textile dyes. A packed bed reactor under batch mode showed 89% decolorization of dye after 56 repetitive cycles. Under continuous flow mode, maximum color removal was achieved with bed length of 36 cm, hydraulic retention time of 2.66 h, and dye concentration of 100 mg/l. Additionally, the reactor decolorized relatively higher concentrations (100-2000 mg/l) of dye. The synthetic dye wastewater containing five textile dyes was decolorized 92% with 62% COD reduction using an immobilized consortium.

  16. Screening fungicides for use in fish culture: Evaluation of the agar plug transfer, cellophane transfer, and agar dilution methods

    USGS Publications Warehouse

    Bailey, Tom A.

    1983-01-01

    The reliability, reproducibility, and usefulness of three screening methods -- the cellophane transfer, the agar plug transfer, and the agar dilution -- to screen aquatic fungicides were evaluated. Achlya flagellata and Saprolegnia hypogyna were exposed to 1, 10, and 100 mg/L of malachite green to test each method. The cellophane transfer and agar plug transfer techniques had similar reliability and reproducibility in rating fungicidal activity, and were both superior to the agar dilution technique. The agar plug transfer and agar dilution techniques adequately projected in vivo activity of malachite green, but the cellophane transfer technique overestimated its activity. Overall, the agar plug transfer technique most accurately rated the activity of malachite green and was the easiest test to perform. It therefore appears to be the method of choice for testing aquatic fungicides.

  17. Recovery of spores of Clostridium botulinum in yeast extract agar and pork infusion agar after heat treatment.

    PubMed

    Odlaug, T E; Pflug, I J

    1977-10-01

    Yeast extract agar, pork infusion agar, and modifications of these media were used to recover heated Clostridium botulinum spores. The D- and z-values were determined. Two type A strains and one type B strain of C. botulinum were studied. In all cases the D-values were largest when the spores were recovered in yeast extract agar, compared to the D-values for spores recovered in pork infusion agar. The z-values for strains 62A and A16037 were largest when the spores were recovered in pork infusion agar. The addition of sodium bicarbonate and sodium thioglycolate to pork infusion agar resulted in D-values for C. botulinum 62A spores similar to those for the same spores recovered in yeast extract agar. The results suggest that sodium bicarbonate and sodium thioglycolate should be added to recovery media for heated C. botulinum spores to obtain maximum plate counts. PMID:335970

  18. Chemical composition, phytotoxic and antifungal properties of Ruta chalepensis L. essential oils.

    PubMed

    Bouabidi, Wafa; Hanana, Mohsen; Gargouri, Samia; Amri, Ismail; Fezzani, Tarek; Ksontini, Mustapha; Jamoussi, Bassem; Hamrouni, Lamia

    2015-01-01

    The chemical composition, and phytotoxic and antifungal activities of the essential oils isolated by using hydrodistillation from the aerial parts of Tunisian rue were evaluated. Significant variations were observed among harvest periods. The analysis of the chemical composition by gas chromatography/mass spectrometry showed that 2-undecanone (33.4-49.8%), 2-heptanol acetate (13.5-15.4%) and α-pinene (9.8-11.9%) were the main components. The antifungal ability of rue essential oils was tested by using disc agar diffusion against ten plant pathogenic fungi. A high antifungal activity was observed for the essential oil isolated at flowering developmental phase. Furthermore, rue essential oils showed high level of herbicidal activity against several weeds.

  19. Chalcone derivatives as potential antifungal agents: Synthesis, and antifungal activity

    PubMed Central

    Gupta, Deepa; Jain, D. K.

    2015-01-01

    Much research has been carried out with the aim to discover the therapeutic values of chalcone derivatives. Chalcones possess wide range of pharmacological activity such as antibacterial, antimalarial, antiprotozoal, antitubercular, anticancer, and antifungal agents etc. The presence of reactive α,β-unsaturated keto group in chalcones is found to be responsible for their biological activity. The rapid developments of resistance to antifungal agents, led to design, and synthesize the new antifungal agents. The derivatives of chalcones were prepared using Claisen–Schmidt condensation scheme with appropriate tetralone and aldehyde derivatives. Ten derivatives were synthesized and were biologically screened for antifungal activity. The newly synthesized derivatives of chalcone showed antifungal activity against fungal species, Microsporum gypseum. The results so obtained were superior or comparable to ketoconazole. It was observed that none of the compounds tested showed positive results for fungi Candida albicans nor against fungi Aspergillus niger. Chalcone derivatives showed inhibitory effect against M. gypseum species of fungus. It was found that among the chalcone derivatives so synthesized, two of them, that is, 4-chloro derivative, and unsubstituted derivative of chalcone showed antifungal activity superior to ketoconazole. Thus, these can be the potential new molecule as antifungal agent. PMID:26317075

  20. Improving agar electrospinnability with choline-based deep eutectic solvents.

    PubMed

    Sousa, Ana M M; Souza, Hiléia K S; Uknalis, Joseph; Liu, Shih-Chuan; Gonçalves, Maria P; Liu, LinShu

    2015-09-01

    Very recently our group has produced novel agar-based fibers by an electrospinning technique using water as solvent and polyvinyl alcohol (PVA) as co-blending polymer. Here, we tested the deep eutectic solvent (DES), (2-hydroxyethyl)trimethylammonium chloride/urea prepared at 1:2 molar ratio, as an alternative solvent medium for agar electrospinning. The electrospun materials were collected with an ethanol bath adapted to a previous electrospinning set-up. One weight percent agar-in-DES showed improved viscoelasticity and hence, spinnability, when compared to 1 wt% agar-in-water and pure agar nanofibers were successfully electrospun if working above the temperature of sol-gel transition (∼80 °C). By changing the solvent medium we decreased the PVA concentration (5 wt% starting solution) and successfully produced composite fibers with high agar contents (50/50 agar/PVA). Best composite fibers were formed with the 50/50 and 30/70 agar/PVA solutions. These fibers were mechanically resistant, showed tailorable surface roughness and diverse size distributions, with most of the diameters falling in the sub-micron range. Both nano and micro forms of agar fibers (used separately or combined) may have potential for the design of new and highly functional agar-based materials. PMID:26116384

  1. Triazole Susceptibilities in Thermotolerant Fungal Isolates from Outdoor Air in the Seoul Capital Area in South Korea.

    PubMed

    Lee, Seungeun; Xu, Siyu; Bivila, Chemmeri Padasseri; Lee, Hyeyoung; Park, Myung Soo; Lim, Young Woon; Yamamoto, Naomichi

    2015-01-01

    Emerging fungi resistant to triazoles are a concern because of the increased use of medical triazoles and exposure to agricultural triazoles. However, little is known about the levels of triazole susceptibility in outdoor airborne fungi making it difficult to assess the risks of inhalation exposure to airborne, antifungal-resistant fungi. This study examined triazole susceptibilities of the airborne thermotolerant fungi isolated from the ambient air of the Seoul Capital Area of South Korea. We used impactor air sampling with triazole-containing nutrient agar plates as the collection substrates to screen for airborne fungal isolates based on their triazole susceptibilities. This study estimated that 0.17% of all the culturable fungi belong to the pathogenic thermotolerant taxa, among which each isolate of Aspergillus niger and Aspergillus tubingensis showed a minimum inhibitory concentration (MIC) of 2 μg/mL or greater for itraconazole. Their concentration in air was 0.4 CFU/m3. Seven human pathogenic Paecilomyces variotii isolates had MICs of 32 μg/mL or greater and lower than 2 μg/mL for the agricultural fungicide tebuconazole and the medical triazole itraconazole, respectively. Though the concentration was low, our results confirm the presence of airborne fungi with high MICs for itraconazole in ambient air. Inhalation is an important exposure route because people inhale more than 10 m3 of air each day. Vigilance is preferred over monitoring for the emergence of triazole-resistant fungal pathogens in ambient outdoor air.

  2. Triazole Susceptibilities in Thermotolerant Fungal Isolates from Outdoor Air in the Seoul Capital Area in South Korea

    PubMed Central

    Lee, Seungeun; Xu, Siyu; Bivila, Chemmeri Padasseri; Lee, Hyeyoung; Park, Myung Soo; Lim, Young Woon; Yamamoto, Naomichi

    2015-01-01

    Emerging fungi resistant to triazoles are a concern because of the increased use of medical triazoles and exposure to agricultural triazoles. However, little is known about the levels of triazole susceptibility in outdoor airborne fungi making it difficult to assess the risks of inhalation exposure to airborne, antifungal-resistant fungi. This study examined triazole susceptibilities of the airborne thermotolerant fungi isolated from the ambient air of the Seoul Capital Area of South Korea. We used impactor air sampling with triazole-containing nutrient agar plates as the collection substrates to screen for airborne fungal isolates based on their triazole susceptibilities. This study estimated that 0.17% of all the culturable fungi belong to the pathogenic thermotolerant taxa, among which each isolate of Aspergillus niger and Aspergillus tubingensis showed a minimum inhibitory concentration (MIC) of 2 μg/mL or greater for itraconazole. Their concentration in air was 0.4 CFU/m3. Seven human pathogenic Paecilomyces variotii isolates had MICs of 32 μg/mL or greater and lower than 2 μg/mL for the agricultural fungicide tebuconazole and the medical triazole itraconazole, respectively. Though the concentration was low, our results confirm the presence of airborne fungi with high MICs for itraconazole in ambient air. Inhalation is an important exposure route because people inhale more than 10 m3 of air each day. Vigilance is preferred over monitoring for the emergence of triazole-resistant fungal pathogens in ambient outdoor air. PMID:26405807

  3. Antifungal and antibacterial activity of marine microorganisms.

    PubMed

    El Amraoui, B; El Amraoui, M; Cohen, N; Fassouane, A

    2014-03-01

    In order to explore marine microorganisms with pharmaceutical potential, marine bacteria, collected from different coastal areas of the Moroccan Atlantic Ocean, were previously isolated from seawater, sediment, marine invertebrates and seaweeds. The antimicrobial activities of these microorganisms were investigated against the pathogens involved in human pathologies. Whole cultures of 34 marine microorganisms were screened for antimicrobial activities using the method of agar diffusion against three Gram-positive bacteria, two Gram-negative bacteria, and against yeast. The results showed that among the 34 isolates studied, 28 (82%) strains have antimicrobial activity against at least one pathogen studied, 11 (32%) strains have antifungal activity and 24 (76%) strains are active against Gram-positive bacteria, while 21 (62%) strains are active against Gram-negative bacteria. Among isolates having antimicrobial activity, 14 were identified and were assigned to the genera Acinetobacter, Aeromonas, Alcaligenes, Bacillus, Chromobacterium, Enterococcus, Pantoea and Pseudomonas. Due to a competitive role for space and nutrient, the marine microorganisms can produce antibiotic substance; therefore, these marine microorganisms were expected to be potential resources of natural antibiotic products.

  4. Mechanisms of echinocandin antifungal drug resistance

    PubMed Central

    Perlin, David S.

    2015-01-01

    Fungal infections due to Candida and Aspergillus species cause extensive morbidity and mortality, especially among immunosuppressed patients, and antifungal therapy is critical to patient management. Yet only a few drug classes are available to treat invasive fungal diseases, and this problem is compounded by the emergence of antifungal resistance. Echinocandin drugs are the preferred choice to treat candidiasis. They are the first cell wall–active agents and target the fungal-specific enzyme glucan synthase, which catalyzes the biosynthesis of β-1,3-glucan, a key cell wall polymer. Therapeutic failures occur rarely among common Candida species, with the exception of Candida glabrata, which are frequently multidrug resistant. Echinocandin resistance in susceptible species is always acquired during therapy. The mechanism of resistance involves amino acid changes in hot-spot regions of Fks subunits of glucan synthase, which decrease the sensitivity of the enzyme to drug. Cellular stress response pathways lead to drug adaptation, which promote the formation of resistant fks strains. Clinical factors promoting echinocandin resistance include empiric therapy, prophylaxis, gastrointestinal reservoirs, and intra-abdominal infections. A better understanding of the echinocandin resistance mechanism, along with cellular and clinical factors promoting resistance, will promote more effective strategies to overcome and prevent echinocandin resistance. PMID:26190298

  5. Antifungal suscepitibility profile of candida spp. oral isolates obtained from denture wearers

    PubMed Central

    Lyon, J.P.; Moreira, L.M.; Cardoso, M.A.G.; Saade, J.; Resende, M.A.

    2008-01-01

    Denture stomatitis is an inflammatory condition that occurs in denture wearers and is frequently associated with Candida yeasts. Antifungal susceptibility profiles have been extensively evaluated for candidiasis patients or immunosupressed individuals, but not for healthy Candida carriers. In the present study, fluconazole, itraconazole, voriconazole, terbinafine and 5-flucytosin were tested against 109 oral Candida spp. isolates. All antifungal agents were effective against the samples tested except for terbinafine. This work might provide epidemiological information about Candida spp. drug susceptibility in oral healthy individuals. PMID:24031286

  6. Susceptibility Testing

    MedlinePlus

    ... page helpful? Also known as: Sensitivity Testing; Drug Resistance Testing; Culture and Sensitivity; C & S; Antimicrobial Susceptibility Formal name: Bacterial and Fungal Susceptibility Testing Related tests: Urine Culture ; ...

  7. Antifungal Potential of Extracellular Metabolites Produced by Streptomyces hygroscopicus against Phytopathogenic Fungi

    PubMed Central

    Prapagdee, Benjaphorn; Kuekulvong, Chutima; Mongkolsuk, Skorn

    2008-01-01

    Indigenous actinomycetes isolated from rhizosphere soils were assessed for in vitro antagonism against Colletotrichum gloeosporioides and Sclerotium rolfsii. A potent antagonist against both plant pathogenic fungi, designated SRA14, was selected and identified as Streptomyces hygroscopicus. The strain SRA14 highly produced extracellular chitinase and β-1,3-glucanase during the exponential and late exponential phases, respectively. Culture filtrates collected from the exponential and stationary phases inhibited the growth of both the fungi tested, indicating that growth suppression was due to extracellular antifungal metabolites present in culture filtrates. The percentage of growth inhibition by the stationary culture filtrate was significantly higher than that of exponential culture filtrate. Morphological changes such as hyphal swelling and abnormal shapes were observed in fungi grown on potato dextrose agar that contained the culture filtrates. However, the antifungal activity of exponential culture filtrates against both the experimental fungi was significantly reduced after boiling or treatment with proteinase K. There was no significant decrease in the percentage of fungal growth inhibition by the stationary culture filtrate that was treated as above. These data indicated that the antifungal potential of the exponential culture filtrate was mainly due to the presence of extracellular chitinase enzyme, whereas the antifungal activity of the stationary culture filtrate involved the action of unknown thermostable antifungal compound(s). PMID:18825279

  8. Antifungal characteristics of a fluorescent Pseudomonas strain involved in the biological control of Rhizoctonia solani.

    PubMed

    Pal, K K; Tilak, K V; Saxena, A K; Dey, R; Singh, C S

    2000-09-01

    A plant growth-promoting isolate of a fluorescent Pseudomonas spp. EM85 was found strongly antagonistic to Rhizoctonia solani, a causal agent of damping-off of cotton. The isolate produced HCN (HCN+), siderophore (Sid+), fluorescent pigments (Flu+) and antifungal antibiotics (Afa+). Tn5::lacZ mutagenesis of isolate EM85 resulted in the production of a series of mutants with altered production of HCN, siderophore, fluorescent pigments and antifungal antibiotics. Characterisation of these mutants revealed that the fluorescent pigment produced in PDA and the siderophore produced in CAS agar were not the same. Afa- and Flu- mutants had a smaller inhibition zone when grown with Rhizoctonia solani than the EM85 wild type. Sid- and HCN mutants failed to inhibit the pathogen in vitro. In a pot experiment, mutants deficient in HCN and siderophore production could suppress the damping-off disease by 52%. However, mutants deficient in fluorescent pigments and antifungal antibiotics failed to reduce the disease severity. Treatments with mutants that produced enhanced amounts of fluorescent pigments and antibiotics compared with EM85 wild type, exhibited an increase in biocontrol efficiency. Monitoring of the mutants in the rhizosphere using the lacZ marker showed identical proliferation of mutants and wild type. Purified antifungal compounds (fluorescent pigment and antibiotic) also inhibited the fungus appreciably in a TLC bioassay. Thus, the results indicate that fluorescent pigment and antifungal antibiotic of the fluorescent Pseudomonas spp. EM85 might be involved in the biological suppression of Rhizoctonia-induced damping-off of cotton.

  9. Antifungal potential of extracellular metabolites produced by Streptomyces hygroscopicus against phytopathogenic fungi.

    PubMed

    Prapagdee, Benjaphorn; Kuekulvong, Chutima; Mongkolsuk, Skorn

    2008-01-01

    Indigenous actinomycetes isolated from rhizosphere soils were assessed for in vitro antagonism against Colletotrichum gloeosporioides and Sclerotium rolfsii. A potent antagonist against both plant pathogenic fungi, designated SRA14, was selected and identified as Streptomyces hygroscopicus. The strain SRA14 highly produced extracellular chitinase and beta-1,3-glucanase during the exponential and late exponential phases, respectively. Culture filtrates collected from the exponential and stationary phases inhibited the growth of both the fungi tested, indicating that growth suppression was due to extracellular antifungal metabolites present in culture filtrates. The percentage of growth inhibition by the stationary culture filtrate was significantly higher than that of exponential culture filtrate. Morphological changes such as hyphal swelling and abnormal shapes were observed in fungi grown on potato dextrose agar that contained the culture filtrates. However, the antifungal activity of exponential culture filtrates against both the experimental fungi was significantly reduced after boiling or treatment with proteinase K. There was no significant decrease in the percentage of fungal growth inhibition by the stationary culture filtrate that was treated as above. These data indicated that the antifungal potential of the exponential culture filtrate was mainly due to the presence of extracellular chitinase enzyme, whereas the antifungal activity of the stationary culture filtrate involved the action of unknown thermostable antifungal compound(s). PMID:18825279

  10. Synthesis of isosteric triterpenoid derivatives and antifungal activity.

    PubMed

    Innocente, Adrine; Casanova, Bruna B; Klein, Fernanda; Lana, Aline D; Pereira, Dariane; Muniz, Mauro N; Sonnet, Pascal; Gosmann, Grace; Fuentefria, Alexandre M; Gnoatto, Simone C B

    2014-03-01

    Dermatomycoses are among the most widespread and common superficial and cutaneous fungal infections in humans. There is an urgent need to develop efficient and non-toxic antimycotic agents with a specific spectrum of activity. Triterpenes have been demonstrated to exhibit a wide range of biological activities, including antifungal activities. In this study, through hemisynthesis, we aimed to obtain triterpene-isosteric molecules from betulinic and ursolic acids to improve the antifungal activity and spectrum of action of these compounds. Six compounds were resynthesized and tested against eleven mucocutaneous and cutaneous mycotic agents. The results of the susceptibility assays were expressed as the minimal inhibitory concentration (MIC). The MIC values of the piperazinyl derivatives of ursolic and betulinic acids that were active against pathogenic yeasts were in the range of 16-32 μg/mL and 4-16 μg/mL, respectively, whereas fungicidal effects were observed at concentrations ranging from 16 to 128 μg/mL and 8 to 128 μg/mL, respectively. The piperazinyl derivative of betulinic acid exhibited an antifungal profile similar to that of terbinafine and was the most effective derivative against dermatophytes. This strategy led to a promising candidate for the development of a new antifungal agent.

  11. Comparison of inhibitory mold agar to Sabouraud dextrose agar as a primary medium for isolation of fungi.

    PubMed

    Scognamiglio, Theresa; Zinchuk, Riva; Gumpeni, Pramod; Larone, Davise H

    2010-05-01

    Clinical specimens cultured on two selective fungal media, inhibitory mold agar (IMA) and Sabouraud dextrose agar (SDA), were compared with respect to recovery of fungi. Of the 840 fungal isolates recovered, 69.3% grew on both IMA and SDA; 24.9% grew only on IMA; and 5.8% grew only on SDA, showing that IMA is superior (P=0.003).

  12. An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus.

    PubMed

    Cold, Emma R; Freyria, Nastasia J; Martínez Martínez, Joaquín; Fernández Robledo, José A

    2016-01-01

    The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham's F12-5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1) Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham's F12-5% FBS- 0.75% agar plates, which could be further propagated in liquid medium; 2) Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3) Chemical susceptibility: Infusing the DME: Ham's F12-5% FBS- 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications.

  13. An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus

    PubMed Central

    Cold, Emma R.; Freyria, Nastasia J.; Martínez Martínez, Joaquín; Fernández Robledo, José A.

    2016-01-01

    The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham’s F12–5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1) Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham’s F12–5% FBS– 0.75% agar plates, which could be further propagated in liquid medium; 2) Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3) Chemical susceptibility: Infusing the DME: Ham’s F12–5% FBS– 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications. PMID:27149378

  14. An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus.

    PubMed

    Cold, Emma R; Freyria, Nastasia J; Martínez Martínez, Joaquín; Fernández Robledo, José A

    2016-01-01

    The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham's F12-5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1) Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham's F12-5% FBS- 0.75% agar plates, which could be further propagated in liquid medium; 2) Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3) Chemical susceptibility: Infusing the DME: Ham's F12-5% FBS- 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications. PMID:27149378

  15. Acetoxychavicol Acetate, an Antifungal Component of Alpinia galanga1.

    PubMed

    Janssen, A M; Scheffer, J J

    1985-12-01

    The essential oils from fresh and dried rhizomes of ALPINIA GALANGA showed an antimicrobial activity against gram-positive bacteria, a yeast and some dermatophytes, using the agar overlay technique. The main components of the oils were also tested and terpinen-4-ol was found most active. An N-pentane/diethyl ether extract of dried rhizomes was active against TRICHOPHYTON MENTAGROPHYTES. 1'-Acetoxychavicol acetate, 1'-acetoxyeugenol acetate and 1'-hydroxychavicol acetate identified by MS and NMR were found in the antifungally active fractions obtained by LSC. Acetoxychavicol acetate was active against the seven fungi tested and its MIC value for dermatophytes ranged from 50 to 250 microg/ml. Dried sliced rhizomes contained 1.5% of this compound. The compound was not found in rhizomes of ALPINIA OFFICINARUM, ZINGIBER OFFICINALE and KAEMPFERIA GALANGA.

  16. Differentiation of Candida dubliniensis from Candida albicans on rosemary extract agar and oregano extract agar.

    PubMed

    de Loreto, Erico Silva; Pozzatti, Patrícia; Alves Scheid, Liliane; Santurio, Deise; Morais Santurio, Janio; Alves, Sydney Hartz

    2008-01-01

    Candida dubliniensis is a recently described pathogenic species which shares many phenotypic features with Candida albicans and therefore, may be misidentified in microbiological laboratories. Because molecular methods can be onerous and unfeasible in routine mycological laboratories with restricted budgets such as those in developing countries, phenotypic techniques have been encouraged in the development of differential media for the presumptive identification of these species. We examined the colony morphology and chlamydospore production of 30 C. dubliniensis isolates and 100 C. albicans isolates on two new proposed media: rosemary (Rosmarinus officinalis) extract agar (REA) and oregano (Origanum vulgare) extract agar (OEA). These substrates are traditionally used as spices and medicinal herbs. In both of these media, all C. dubliniensis isolates (100%) showed rough colonies with peripheral hyphal fringes and abundant chlamydospores after 24 to 48 hr of incubation at 25 degrees C. In contrast, under the same conditions, all isolates of C. albicans (100%) showed smooth colonies without hyphal fringes or chlamydospores. In conclusion, REA and OEA offer a simple, rapid, and inexpensive screening media for the differentiation of C. albicans and C. dubliniensis.

  17. 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

  18. In vitro and in vivo activity of a novel antifungal small molecule against Candida infections.

    PubMed

    Wong, Sarah Sze Wah; Kao, Richard Yi Tsun; Yuen, Kwok Yong; Wang, Yu; Yang, Dan; Samaranayake, Lakshman Perera; Seneviratne, Chaminda Jayampath

    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

  19. Antibacterial, Antifungal and antioxidant activities of some medicinal plants.

    PubMed

    Wazir, Asma; Mehjabeen, -; Jahan, Noor; Sherwani, Sikander Khan; Ahmad, Mansoor

    2014-11-01

    The purpose of this study was to evaluate the antibacterial, antifungal and antioxidant activities of medicinal plants. The antibacterial activity of methanolic extracts of three medicinal plants (Swertia chirata, Terminalia bellerica and Zanthoxylum armatum) were tested against Gentamicin (standard drug) on eleven gram positive and seventeen gram negative bacteria by agar well method. It was revealed that seven-gram negative and six gram positive bacterial species were inhibited by these plant extracts. Minimum inhibitory concentrations (MIC) of the extracts were determined by broth micro-dilution method. The significant MIC value of Swertia chirata was 20mg/ml against Serratia marcesens, Zanthoxylum armatum was 10 mg/ml against Aeromonas hydrophila and Terminali bellerica was 20mg/ml against Acinetobacter baumanii as well as Serratia marcesens. Antifungal screening was done for methanolic extracts of these plants by agar well method with the 6 saprophytic, 5 dermatophytic and 6 yeasts. In this case Griseofulvin was used as a standard. All saprophytes and dermatophytes were showed resistance by these plants extracts except Microsporum canis, which was inhibited by Z. armatum and S. chirata extracts. The significant MIC value of Zanthoxylum armatum was 10mg/ml against Microsporum canis and Swertia chirata was 10mg/ml against Candida tropicalis. The anti-oxidant study was performed by DPPH free radical scavenging assay using ascorbic acid as a reference standard. Significant antioxidant activities were observed by Swertia chirata and Zanthoxylum armatum at concentration 200μg/ml was 70% DPPH scavenging activity (EC50=937.5μg/ml) while Terminalia bellerica showed 55.6% DPPH scavenging activity (EC50=100μg/ml). This study has shown that these plants could provide potent antibacterial compounds and may possible preventive agents in ROS related ailments.

  20. Direct Protocol for Ambient Mass Spectrometry Imaging on Agar Culture.

    PubMed

    Angolini, Célio Fernando F; Vendramini, Pedro Henrique; Araújo, Francisca D S; Araújo, Welington L; Augusti, Rodinei; Eberlin, Marcos N; de Oliveira, Luciana Gonzaga

    2015-07-01

    Herein we describe a new protocol that allows direct mass spectrometry imaging (IMS) of agar cultures. A simple sample dehydration leads to a thin solid agar, which enables the direct use of spray-based ambient mass spectrometry techniques. To demonstrate its applicability, metal scavengers siderophores were imaged directly from agar culture of S. wadayamensis, and well resolved and intense images were obtained using both desorption electrospray ionization (DESI) and easy ambient sonic-spray ionization (EASI) with well-defined selective spatial distributions for the free and the metal-bound molecules, providing clues for their roles in cellular metabolism.

  1. Nationwide study of candidemia, antifungal use, and antifungal drug resistance in Iceland, 2000 to 2011.

    PubMed

    Asmundsdottir, Lena Ros; Erlendsdottir, Helga; Gottfredsson, Magnus

    2013-03-01

    Candidemia is often a life-threatening infection, with highly variable incidence among countries. We conducted a nationwide study of candidemia in Iceland from 2000 to 2011, in order to determine recent trends in incidence rates, fungal species distribution, antifungal susceptibility patterns, and concurrent antifungal consumption. A total of 208 infection episodes in 199 patients were identified. The average incidence during the 12 years was 5.7 cases/100,000 population/year, which was significantly higher than that from 1990 to 1999 (4.3/100,000/year; P = 0.02). A significant reduction in the use of blood cultures was noted in the last 3 years of the study, coinciding with the economic crisis in the country (P < 0.001). Age-specific incidence rates were highest among patients at the extremes of age, 20.7/100,000 for <1 year of age and 18.1/100,000 for >60 years, and varied by gender. Age-specific incidence among males >80 years old was 28.6/100,000/year, and it was 8.3/100,000/year for females in this age group (P = 0.028). The 30-day survival rate among adult patients remained unchanged compared to that from 1990 to 1999 (70.4% versus 69.5%, P = 0.97). Candida albicans was the predominant species (56%), followed by C. glabrata (16%) and C. tropicalis (13%). The species distribution remained stable compared to that from previous decades. Fluconazole use increased 2.4-fold from 2000 to 2011, with no increase in resistance. In summary, the incidence of candidemia in Iceland has continued to increase but may have reached a steady state, and no increase in antifungal drug resistance has been noted. Decreased use of blood cultures toward the end of the study may have influenced detection rates.

  2. Nationwide Study of Candidemia, Antifungal Use, and Antifungal Drug Resistance in Iceland, 2000 to 2011

    PubMed Central

    Asmundsdottir, Lena Ros; Erlendsdottir, Helga

    2013-01-01

    Candidemia is often a life-threatening infection, with highly variable incidence among countries. We conducted a nationwide study of candidemia in Iceland from 2000 to 2011, in order to determine recent trends in incidence rates, fungal species distribution, antifungal susceptibility patterns, and concurrent antifungal consumption. A total of 208 infection episodes in 199 patients were identified. The average incidence during the 12 years was 5.7 cases/100,000 population/year, which was significantly higher than that from 1990 to 1999 (4.3/100,000/year; P = 0.02). A significant reduction in the use of blood cultures was noted in the last 3 years of the study, coinciding with the economic crisis in the country (P < 0.001). Age-specific incidence rates were highest among patients at the extremes of age, 20.7/100,000 for <1 year of age and 18.1/100,000 for >60 years, and varied by gender. Age-specific incidence among males >80 years old was 28.6/100,000/year, and it was 8.3/100,000/year for females in this age group (P = 0.028). The 30-day survival rate among adult patients remained unchanged compared to that from 1990 to 1999 (70.4% versus 69.5%, P = 0.97). Candida albicans was the predominant species (56%), followed by C. glabrata (16%) and C. tropicalis (13%). The species distribution remained stable compared to that from previous decades. Fluconazole use increased 2.4-fold from 2000 to 2011, with no increase in resistance. In summary, the incidence of candidemia in Iceland has continued to increase but may have reached a steady state, and no increase in antifungal drug resistance has been noted. Decreased use of blood cultures toward the end of the study may have influenced detection rates. PMID:23269738

  3. Antifungal Prophylaxis in Immunocompromised Patients.

    PubMed

    Vazquez, Lourdes

    2016-01-01

    Invasive fungal infections (IFIs) represent significant complications in patients with hematological malignancies. Chemoprevention of IFIs may be important in this setting, but most antifungal drugs have demonstrated poor efficacy, particularly in the prevention of invasive aspergillosis. Antifungal prophylaxis in hematological patients is currently regarded as the gold standard in situations with a high risk of infection, such as acute leukemia, myelodysplastic syndromes, and autologous or allogeneic hematopoietic stem cell transplantation. Over the years, various scientific societies have established a series of recommendations for antifungal prophylaxis based on prospective studies performed with different drugs. However, the prescription of each agent must be personalized, adapting its administration to the characteristics of individual patients and taking into account possible interactions with concomitant medication. PMID:27648203

  4. Haloprogin: a Topical Antifungal Agent

    PubMed Central

    Harrison, E. F.; Zwadyk, P.; Bequette, R. J.; Hamlow, E. E.; Tavormina, P. A.; Zygmunt, W. A.

    1970-01-01

    Haloprogin was shown to be a highly effective agent for the treatment of experimentally induced topical mycotic infections in guinea pigs. Its in vitro spectrum of activity also includes yeasts, yeastlike fungi (Candida species), and certain gram-positive bacteria. The in vitro and in vivo antifungal activity of haloprogin against dermatophytes was equal to that observed with tolnaftate. The striking differences between the two agents were the marked antimonilial and selective antibacterial activities shown by haloprogin, contrasted with the negligible activities found with tolnaftate. Addition of serum decreased the in vitro antifungal activity of haloprogin to a greater extent than that of tolnaftate; however, diminished antifungal activity was not observed when haloprogin was applied topically to experimental dermatophytic infections. Based on its broad spectrum of antimicrobial activity, haloprogin may prove to be a superior topical agent in the treatment of dermatophytic and monilial infections in man. PMID:5422306

  5. Antifungal Prophylaxis in Immunocompromised Patients

    PubMed Central

    Vazquez, Lourdes

    2016-01-01

    Invasive fungal infections (IFIs) represent significant complications in patients with hematological malignancies. Chemoprevention of IFIs may be important in this setting, but most antifungal drugs have demonstrated poor efficacy, particularly in the prevention of invasive aspergillosis. Antifungal prophylaxis in hematological patients is currently regarded as the gold standard in situations with a high risk of infection, such as acute leukemia, myelodysplastic syndromes, and autologous or allogeneic hematopoietic stem cell transplantation. Over the years, various scientific societies have established a series of recommendations for antifungal prophylaxis based on prospective studies performed with different drugs. However, the prescription of each agent must be personalized, adapting its administration to the characteristics of individual patients and taking into account possible interactions with concomitant medication.

  6. Antifungal Prophylaxis in Immunocompromised Patients

    PubMed Central

    Vazquez, Lourdes

    2016-01-01

    Invasive fungal infections (IFIs) represent significant complications in patients with hematological malignancies. Chemoprevention of IFIs may be important in this setting, but most antifungal drugs have demonstrated poor efficacy, particularly in the prevention of invasive aspergillosis. Antifungal prophylaxis in hematological patients is currently regarded as the gold standard in situations with a high risk of infection, such as acute leukemia, myelodysplastic syndromes, and autologous or allogeneic hematopoietic stem cell transplantation. Over the years, various scientific societies have established a series of recommendations for antifungal prophylaxis based on prospective studies performed with different drugs. However, the prescription of each agent must be personalized, adapting its administration to the characteristics of individual patients and taking into account possible interactions with concomitant medication. PMID:27648203

  7. Treating chromoblastomycosis with systemic antifungals.

    PubMed

    Bonifaz, Alexandro; Paredes-Solís, Vanessa; Saúl, Amado

    2004-02-01

    Chromoblastomycosis is a subcutaneous mycosis for which there is no treatment of choice but rather, several treatment options, with low cure rates and many relapses. The choice of treatment should consider several conditions, such as the causal agent (the most common one being Fonsecaea pedrosoi ), extension of the lesions, clinical topography and health status of the patient. Most oral and systemic antifungals have been used; the best results have been obtained with itraconazole and terbinafine at high doses, for a mean of 6 - 12 months. In extensive and refractory cases, chemotherapy with oral antifungals may be associated with thermotherapy (local heat and/or cryosurgery). Limited or early cases may be managed with surgical methods, always associated with oral antifungal agents. It is important to determine the in vitro sensitivity of the major causal agents to the various drugs, by estimating the minimum inhibitory concentration, as well as drug tolerability and drug interactions.

  8. Antitumor and antifungal activities of organic extracts of seacucumber Holothuria atra from the southeast coast of India

    NASA Astrophysics Data System (ADS)

    Dhinakaran, Devaraj Isaac; Lipton, Aaron Premnath

    2015-02-01

    In phylum Echinodermata, the family Holothuridae is distinguished by its capacity of bioactive compounds. Sea cucumber Holothuria atra is commonly known as the lollyfish. The antifungal activity was detected using agar well diffusion method against the various fungal strains such as Trichoderma viride, Aspergillus niger, Aspergillus flavis, Candida albicans and Penicillium chrysogenum. Relatively high antifungal activity was seen against Candida albicans at 100 μL-1 concentration of extracts. Zone of inhibition was measured at 18 mm of diameter. The anti-tumor activities were detected against the Vero and Hep2 cell lines using MTT assay. The cells were treated with H. atra extract at concentrations 0.078-10mg mL-1. The extract showed high proliferative activity against the Hep2 cells. The body wall extracts of sea cucumber ( H. atra) showed effective antifungal and antitumor activities. All these findings suggest that the extracts could be used for the development of drugs.

  9. Automated counting of bacterial colony forming units on agar plates.

    PubMed

    Brugger, Silvio D; Baumberger, Christian; Jost, Marcel; Jenni, Werner; Brugger, Urs; Mühlemann, Kathrin

    2012-01-01

    Manual counting of bacterial colony forming units (CFUs) on agar plates is laborious and error-prone. We therefore implemented a colony counting system with a novel segmentation algorithm to discriminate bacterial colonies from blood and other agar plates.A colony counter hardware was designed and a novel segmentation algorithm was written in MATLAB. In brief, pre-processing with Top-Hat-filtering to obtain a uniform background was followed by the segmentation step, during which the colony images were extracted from the blood agar and individual colonies were separated. A Bayes classifier was then applied to count the final number of bacterial colonies as some of the colonies could still be concatenated to form larger groups. To assess accuracy and performance of the colony counter, we tested automated colony counting of different agar plates with known CFU numbers of S. pneumoniae, P. aeruginosa and M. catarrhalis and showed excellent performance.

  10. A novel antifungal protein of Bacillus subtilis B25.

    PubMed

    Tan, Zhiqiong; Lin, Baoying; Zhang, Rongyi

    2013-01-01

    Bacillus subtilis B25 was isolated from banana rhizosphere soil. It has been confirmed for B25 to have stronger antagonism against Fusarium oxysporum f.sp.cubense, Additionally B25 has good inhibitory to plant pathogens, including Corynespora cassiicola, Alternaria solani, Botrytis cinerea and Colletotrichum gloeosporioides on potato dextrose agar (PDA) plates. The antagonistic substance can be extracted from cell-free culture broth supernatants by 70% (w/v) (NH4)2 SO4 saturation. Clear blank band was observed between the protein and a pathogen. The examination of antagonistic mechanism under light microscope showed that the antifungal protein of B25 appeared to inhibit pathogens by leading to mycelium and spores tumescence, distortion, abnormality. The isolation procedure comprised ion exchange chromatography on DEAE-Sephadex Fast Flow and gel filtration chromatography on SephadexG-100. The purified antifungal fraction showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The active fraction was identified by NanoLC-ESI-MS/MS The amino acid sequences of 17 peptides segments were obtained. The analysis of the protein suggested that it was a hypothetical protein (gi154685475), with a relative molecular mass of 38708.67 Da and isoelectric point (pI) of 5.63. PMID:24255843

  11. [Evaluation of blood agar medium for the growth of mycobacteria].

    PubMed

    Coban, Ahmet Yılmaz; Akgüneş, Alper; Durupınar, Belma

    2011-10-01

    This study was aimed to evaluate the performance of blood agar for the growth of mycobacteria from clinical specimens sent to Mycobacteriology Laboratory of Samsun Chest Diseases Hospital. One hundred fifty six clinical specimens including 123 sputum, 28 bronchoalveolar lavage (BAL) and 5 pleural fluid specimens were inoculated in Löwenstein-Jensen (LJ), BACTEC MGIT 960 system (Becton Dickinson, USA) and blood agar following decontamination process. The specimens were also simultaneously examined for the presence of acid-fast bacilli (AFB). Thirty five mycobacteria strains (33 Mycobacterium tuberculosis and 2 atypical mycobacteria) grew in blood agar, 38 (36 M.tuberculosis and 2 atypical mycobacteria) in LJ media and 46 (44 M.tuberculosis and 2 atypical mycobacteria) in BACTEC MGIT 960 system. Among 29 AFB negative specimens, 20 revealed growth in both blood agar and LJ medium and 27 in MGIT system. AFB positive 20 samples yielded growth in 15 samples in blood agar, 18 in LJ medium and 19 in MGIT system. Among the total of 156 samples, contamination was observed in 15 (9.6%) samples in blood agar, 16 (10.2%) in LJ medium and 18 (11.5%) in MGIT system. Growth time was 5-35 days (mean 18 ± 7.4), 11-35 days (mean 19 ± 5.9) and 5-15 days (mean 10 ± 2.4) for blood agar, LJ medium and BACTEC MGIT 960 system, respectively. The three samples which revealed contamination in BACTEC MGIT 960 system, grew successfully in both blood agar and LJ medium without contamination. In one sample, growth was observed only in LJ medium but neither in blood agar nor BACTEC MGIT 960 system. However, in another sample, growth was observed only in blood agar while no growth was detected in LJ or BACTEC MGIT 960 system. Six samples yielded mycobacteria only in BACTEC MGIT 960 system. These results indicated that simultaneous use of one liquid and one solid medium to grow mycobacteria from the clinical samples seemed to be complementary. Blood agar was a promising choice since it was found

  12. [Assessment of 2 automated microdilution techniques compared to an agar dilution method in determining sensitivity to fosfomycin in strains of carbapenem-resistant Pseudomonas aeruginosa].

    PubMed

    Gil-Romero, Yolanda; Regodón-Domínguez, Marta; Wilhelmi de Cal, Isabel; López-Fabal, Fátima; Gómez-Garcés, José Luis

    2016-01-01

    Carbapenems-resistance in Pseudomonas aeruginosa isolates has been widely reported. Fosfomycin has been shown to act synergistically with other antimicrobials. The agar dilution method was approved for susceptibility testing for fosfomycin and Pseudomonas aeruginosa. However, broth microdilution methods are the basis of systems currently used in clinical microbiology laboratories. The results of this study indicate that these methods are acceptable as susceptibility testing methods for fosfomycin against these organisms.

  13. Detection of amphotericin B resistance in Candida haemulonii and closely related species by use of the Etest, Vitek-2 yeast susceptibility system, and CLSI and EUCAST broth microdilution methods.

    PubMed

    Shin, Jong Hee; Kim, Mi-Na; Jang, Sook Jin; Ju, Min Young; Kim, Soo Hyun; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook

    2012-06-01

    The emerging fungal pathogens Candida haemulonii and Candida pseudohaemulonii often show high-level resistance to amphotericin B (AMB). We compared the utilities of five antifungal susceptibility testing methods, i.e., the Etest using Mueller-Hinton agar supplemented with glucose and methylene blue (Etest-MH), the Etest using RPMI agar supplemented with glucose (Etest-RPG), the Vitek-2 yeast susceptibility system, and the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution methods, for the detection of AMB-resistant isolates of C. haemulonii and closely related species. Thirty-eight clinical isolates (8 C. haemulonii, 10 C. pseudohaemulonii, and 20 Candida auris isolates) were analyzed. Of the 18 C. haemulonii and C. pseudohaemulonii isolates, 18, 15, 18, 10, and 9 exhibited AMB MICs of >1 μg/ml by the Etest-MH, Etest-RPG, Vitek-2, CLSI, and EUCAST methods, respectively. All 20 C. auris isolates showed AMB MICs of ≤1 μg/ml by all five methods. Of the methods, the Etest-MH generated the broadest distribution of AMB MICs for all 38 isolates and showed the best discrimination between the C. haemulonii and C. pseudohaemulonii isolates (4 to 32 μg/ml) and those of C. auris (0.125 to 0.5 μg/ml). Taking the Etest-MH as the reference method, the essential agreements (within two dilutions) for the Etest-RPG, Vitek-2, CLSI, and EUCAST methods were 84, 92, 55, and 55%, respectively; the categorical agreements were 92, 92, 79, and 76%, respectively. This study provides the first data on the efficacy of the Etest-MH and its excellent agreement with Vitek-2 for discriminating AMB-resistant from AMB-susceptible isolates of these Candida species.

  14. Polyglycolic acid microneedles modified with inkjet-deposited antifungal coatings.

    PubMed

    Boehm, Ryan D; Daniels, Justin; Stafslien, Shane; Nasir, Adnan; Lefebvre, Joe; Narayan, Roger J

    2015-01-01

    In this study, the authors examined use of piezoelectric inkjet printing to apply an antifungal agent, voriconazole, to the surfaces of biodegradable polyglycolic acid microneedles. Polyglycolic acid microneedles with sharp tips (average tip radius = 25 ± 3 μm) were prepared using a combination of injection molding and drawing lithography. The elastic modulus (9.9 ± 0.3 GPa) and hardness (588.2 ± 33.8 MPa) values of the polyglycolic acid material were determined using nanoindentation and were found to be suitable for use in transdermal drug delivery devices. Voriconazole was deposited onto the polyglycolic acid microneedles by means of piezoelectric inkjet printing. It should be noted that voriconazole has poor solubility in water; however, it is readily soluble in many organic solvents. Optical imaging, scanning electron microscopy, energy dispersive x-ray spectrometry, and Fourier transform infrared spectroscopy were utilized to examine the microneedle geometries and inkjet-deposited surface coatings. Furthermore, an in vitro agar plating study was performed on the unmodified, vehicle-modified, and voriconazole-modified microneedles. Unlike the unmodified and vehicle-modified microneedles, the voriconazole-modified microneedles showed antifungal activity against Candida albicans. The unmodified, vehicle-modified, and voriconazole-modified microneedles did not show activity against Escherichia coli, Pseudomonas aeruginosa, or Staphylococcus aureus. The results indicate that piezoelectric inkjet printing may be useful for loading transdermal drug delivery devices such as polyglycolic acid microneedles with antifungal pharmacologic agents and other pharmacologic agents with poor solubility in aqueous solutions.

  15. Polyglycolic acid microneedles modified with inkjet-deposited antifungal coatings.

    PubMed

    Boehm, Ryan D; Daniels, Justin; Stafslien, Shane; Nasir, Adnan; Lefebvre, Joe; Narayan, Roger J

    2015-01-01

    In this study, the authors examined use of piezoelectric inkjet printing to apply an antifungal agent, voriconazole, to the surfaces of biodegradable polyglycolic acid microneedles. Polyglycolic acid microneedles with sharp tips (average tip radius = 25 ± 3 μm) were prepared using a combination of injection molding and drawing lithography. The elastic modulus (9.9 ± 0.3 GPa) and hardness (588.2 ± 33.8 MPa) values of the polyglycolic acid material were determined using nanoindentation and were found to be suitable for use in transdermal drug delivery devices. Voriconazole was deposited onto the polyglycolic acid microneedles by means of piezoelectric inkjet printing. It should be noted that voriconazole has poor solubility in water; however, it is readily soluble in many organic solvents. Optical imaging, scanning electron microscopy, energy dispersive x-ray spectrometry, and Fourier transform infrared spectroscopy were utilized to examine the microneedle geometries and inkjet-deposited surface coatings. Furthermore, an in vitro agar plating study was performed on the unmodified, vehicle-modified, and voriconazole-modified microneedles. Unlike the unmodified and vehicle-modified microneedles, the voriconazole-modified microneedles showed antifungal activity against Candida albicans. The unmodified, vehicle-modified, and voriconazole-modified microneedles did not show activity against Escherichia coli, Pseudomonas aeruginosa, or Staphylococcus aureus. The results indicate that piezoelectric inkjet printing may be useful for loading transdermal drug delivery devices such as polyglycolic acid microneedles with antifungal pharmacologic agents and other pharmacologic agents with poor solubility in aqueous solutions. PMID:25732934

  16. Biochemical approaches to selective antifungal activity. Focus on azole antifungals.

    PubMed

    Vanden Bossche, H; Marichal, P; Gorrens, J; Coene, M C; Willemsens, G; Bellens, D; Roels, I; Moereels, H; Janssen, P A

    1989-01-01

    Azole antifungals (e.g. the imidazoles: miconazole, clotrimazole, bifonazole, imazalil, ketoconazole, and the triazoles: diniconazole, triadimenol, propiconazole, fluconazole and itraconazole) inhibit in fungal cells the 14 alpha-demethylation of lanosterol or 24-methylenedihydrolanosterol. The consequent inhibition of ergosterol synthesis originates from binding of the unsubstituted nitrogen (N-3 or N-4) of their imidazole or triazole moiety to the heme iron and from binding of their N-1 substituent to the apoprotein of a cytochrome P-450 (P-450(14)DM) of the endoplasmic reticulum. Great differences in both potency and selectivity are found between the different azole antifungals. For example, after 16h of growth of Candida albicans in medium supplemented with [14C]-acetate and increasing concentrations of itraconazole, 100% inhibition of ergosterol synthesis is achieved at 3 x 10(-8) M. Complete inhibition of this synthesis by fluconazole is obtained at 10(-5) M only. The agrochemical imidazole derivative, imazalil, shows high selectivity, it has almost 80 and 98 times more affinity for the Candida P-450(s) than for those of the piglet testes microsomes and bovine adrenal mitochondria, respectively. However, the topically active imidazole antifungal, bifonazole, has the highest affinity for P-450(s) of the testicular microsomes. The triazole antifungal itraconazole inhibits at 10(-5) M the P-450-dependent aromatase by 17.9, whereas 50% inhibition of this enzyme is obtained at about 7.5 x 10(-6)M of the bistriazole derivative fluconazole. The overall results show that both the affinity for the fungal P-450(14)DM and the selectivity are determined by the nitrogen heterocycle and the hydrophobic N-1 substituent of the azole antifungals. The latter has certainly a greater impact. The presence of a triazole and a long hypdrophobic nonligating portion form the basis for itraconazole's potency and selectivity.

  17. Use of antifungal drugs in hematology

    PubMed Central

    Nucci, Marcio

    2012-01-01

    Invasive fungal disease represents a major complication in hematological patients. Antifungal agents are frequently used in hematologic patients for different purposes. In neutropenic patients, antifungal agents may be used as prophylaxis, as empiric or preemptive therapy, or to treat an invasive fungal disease that has been diagnosed. The hematologist must be familiar with the epidemiology, diagnostic tools and strategies of antifungal use, as well as the pharmacologic proprieties of the different antifungal agents. In this paper the principal antifungal agents used in hematologic patients will be discussed as will the clinical scenarios where these agents have been used. PMID:23125547

  18. Enhanced chlorine resistance of tap water-adapted Legionella pneumophila as compared with agar medium-passaged strains.

    PubMed Central

    Kuchta, J M; States, S J; McGlaughlin, J E; Overmeyer, J H; Wadowsky, R M; McNamara, A M; Wolford, R S; Yee, R B

    1985-01-01

    Previous studies have shown that bacteria maintained in a low-nutrient "natural" environment such as swimming pool water are much more resistant to disinfection by various chemical agents than strains maintained on rich media. In the present study a comparison was made of the chlorine (Cl2) susceptibility of hot-water tank isolates of Legionella pneumophila maintained in tap water and strains passaged on either nonselective buffered charcoal-yeast extract or selective differential glycine-vancomycin-polymyxin agar medium. Our earlier work has shown that environmental and clinical isolates of L. pneumophila maintained on agar medium are much more resistant to Cl2 than coliforms are. Under the present experimental conditions (21 degrees C, pH 7.6 to 8.0, and 0.25 mg of free residual Cl2 per liter, we found the tap water-maintained L. pneumophila strains to be even more resistant than the agar-passaged isolates. Under these conditions, 99% kill of tap water-maintained strains of L. pneumophila was usually achieved within 60 to 90 min compared with 10 min for agar-passaged strains. Samples from plumbing fixtures in a hospital yielded legionellae which were "super"-chlorine resistant when assayed under natural conditions. After one agar passage their resistance dropped to levels of comparable strains which had not been previously exposed to additional chlorination. These studies more closely approximate natural conditions than our previous work and show that tap water-maintained L. pneumophila is even more resistant to Cl2 than its already resistant agar medium-passaged counterpart. PMID:3896142

  19. Resistance to antifungal agents in the critical care setting: problems and perspectives.

    PubMed

    Martins, M D; Rex, J H

    1996-08-01

    As is the case with antibacterial agents, the increasing use of antifungal agents has led to development of antifungal resistance, the most clinically important of which is the resistance of Candida to fluconazole. While mutation to high-level fluconazole resistance is possible, the most important aspect of fluconazole resistance for patients in the ICU is the possibility of an epidemiologic shift away from such susceptible species as C. albicans and C. parapsilosis toward the most resistant species, such as C. glabrata and C. krusei. Resistance to amphotericin B by Candida is also possible, but less frequent. Strategies for treating invasive Candida infections must consider the relative rates of non-C. albicans Candida infection and the likelihood of antifungal resistance. The agents that cause invasive mold infections in the ICU are intrinsically moderately resistant to the available antifungal agents, and therapy depends less on the choice of antifungal therapy than on the correction of predisposing factors. The role of susceptibility testing as a guide in selecting appropriate therapy for all of these infections is as yet incompletely defined, but testing for resistance to fluconazole may soon be ready for clinical use. PMID:8856751

  20. Candida tropicalis Antifungal Cross-Resistance Is Related to Different Azole Target (Erg11p) Modifications

    PubMed Central

    Forastiero, A.; Mesa-Arango, A. C.; Alastruey-Izquierdo, A.; Alcazar-Fuoli, L.; Bernal-Martinez, L.; Pelaez, T.; Lopez, J. F.; Grimalt, J. O.; Gomez-Lopez, A.; Cuesta, I.; Zaragoza, O.

    2013-01-01

    Candida tropicalis ranks between third and fourth among Candida species most commonly isolated from clinical specimens. Invasive candidiasis and candidemia are treated with amphotericin B or echinocandins as first-line therapy, with extended-spectrum triazoles as acceptable alternatives. Candida tropicalis is usually susceptible to all antifungal agents, although several azole drug-resistant clinical isolates are being reported. However, C. tropicalis resistant to amphotericin B is uncommon, and only a few strains have reliably demonstrated a high level of resistance to this agent. The resistance mechanisms operating in C. tropicalis strains isolated from clinical samples showing resistance to azole drugs alone or with amphotericin B cross-resistance were elucidated. Antifungal drug resistance was related to mutations of the azole target (Erg11p) with or without alterations of the ergosterol biosynthesis pathway. The antifungal drug resistance shown in vitro correlated very well with the results obtained in vivo using the model host Galleria mellonella. Using this panel of strains, the G. mellonella model system was validated as a simple, nonmammalian minihost model that can be used to study in vitro-in vivo correlation of antifungals in C. tropicalis. The development in C. tropicalis of antifungal drug resistance with different mechanisms during antifungal treatment has potential clinical impact and deserves specific prospective studies. PMID:23877676

  1. Antifungal resistance in yeast vaginitis.

    PubMed Central

    Dun, E.

    1999-01-01

    The increased number of vaginal yeast infections in the past few years has been a disturbing trend, and the scientific community has been searching for its etiology. Several theories have been put forth to explain the apparent increase. First, the recent widespread availability of low-dosage, azole-based over-the-counter antifungal medications for vaginal yeast infections encourages women to self-diagnose and treat, and women may be misdiagnosing themselves. Their vaginitis may be caused by bacteria, parasites or may be a symptom of another underlying health condition. As a result, they may be unnecessarily and chronically expose themselves to antifungal medications and encourage fungal resistance. Second, medical technology has increased the life span of seriously immune compromised individuals, yet these individuals are frequently plagued by opportunistic fungal infections. Long-term and intense azole-based antifungal treatment has been linked to an increase in resistant Candida and non-Candida species. Thus, the future of limiting antifungal resistance lies in identifying the factors promoting resistance and implementing policies to prevent it. PMID:10907778

  2. Antifungal activity of juniper extracts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sawdust from three species of Juniperus (i.e., J. virginianna, J. occidentalis, and J. ashei) were extracted with hexane or ethanol and the extracts tested for antifungal activity against four species of wood-rot fungi. These species studied represent the junipers with the greatest potential for co...

  3. PRELIMIARY PHYTOCHEMICAL ANALYSIS AND ANTIFUNGAL ACTIVITIES OF CRUDE EXTRACTS OF ZALEYA PENTANDRA AND CORCHORUS DEPRESSUS LINN.

    PubMed

    Afzal, Samina; Chaudhary, Bashir Ahmad; Ahmad, Ashfaq; Afzali, Khurram

    2015-01-01

    Zaleya pentandra (Zp) and Cochoms depressus Linn. (Cd) have been considered as herbs with potential therapeutic benefits. Zp and Cd belong to the important family Aizoaceae and Tiliaceae, respectively. The extractions were carried out successively with methanol and dichloromethane at room temperature for 24 h. Preliminary phytochemical screening of Zp and Cd revealed the presence of steroids, alkaloids, saponins, and anthraquinones. The methanolic and dichloromethane extracts of selected plants were subjected to examination of antifungal activity by using agar tube dilution. The extracts were tested against different fungi such as A. nigeir, A. flavus, F. solani, A. funigatis and Mucor. The dichloromethane extract of aerial parts of Cd showed high antifungal activity against A. niger as compared to all other tested extracts. PMID:26642683

  4. Antibacterial and antifungal activity of Iranian propolis against Staphylococcus aureus and Candida albicans.

    PubMed

    Ghasem, Yousef-Beigi; Ownagh, Abdolghaffar; Hasanloei, M

    2007-04-15

    Propolis samples from West North region of Iran were studied for their antibacterial (against Staphylococcus aureus) and antifungal (against Candida albicans) activities. In this article, yield of extracts and their pH values were measured. Antibacterial and antifungal activities of Ethanol-Extracted Propolis (EEP) were investigated by Petri dish bioassay method. Dilutions of EPP in agar with serial concentrations ranging from 0/04 to 10% (W/V) were prepared and antimicrobial activities were determined as Minimal Inhibitory Concentrations (MIC). All samples were active against the fungal and bacterial test strains. MIC values for different propolis samples against Staphylococcus aureus were, respectively 4, 3 and 1.5% (W/V) and against Candida albicans were, respectively 2, 4 and 3% (W/V).

  5. Comparison of the BBL CHROMagar Staph aureus Agar Medium to Conventional Media for Detection of Staphylococcus aureus in Respiratory Samples

    PubMed Central

    Flayhart, Diane; Lema, Clara; Borek, Anita; Carroll, Karen C.

    2004-01-01

    Screening for Staphylococcus aureus has become routine in certain patient populations. This study is the first clinical evaluation of the BBL CHROMagar Staph aureus agar (CSA) medium (BD Diagnostics, Sparks, Md.) for detection of S. aureus in nasal surveillance cultures and in respiratory samples from cystic fibrosis (CF) patients. S. aureus colonies appear mauve on CSA. Other organisms are inhibited or produce a distinctly different colony color. S. aureus was identified from all media by slide coagulase, exogenous DNase, and mannitol fermentation assays. Susceptibility testing was performed using the agar dilution method. A total of 679 samples were evaluated. All samples were inoculated onto CSA. Nasal surveillance cultures were inoculated onto sheep blood agar (SBA) (BD Diagnostics), and samples from CF patients were inoculated onto mannitol salt agar (MSA) (BD Diagnostics). Of the 679 samples cultured, 200 organisms produced a mauve color on CSA (suspicious for S. aureus) and 180 were positive for S. aureus on SBA or MSA. Of 200 CSA-positive samples 191 were identified as S. aureus. Nine mauve colonies were slide coagulase negative and were subsequently identified as Staphylococcus lugdunensis (one), Staphylococcus epidermidis (three), Staphylococcus haemolyticus (one), and Corynebacterium species (four). CSA improved the ability to detect S. aureus by recovering 12 S. aureus isolates missed by conventional media. Of the 192 S. aureus isolates recovered, 122 were methicillin susceptible and 70 were methicillin resistant. Overall, the sensitivity and specificity of CSA in this study were 99.5 and 98%, respectively. There was no difference in the performance of the slide coagulase test or in susceptibility testing performed on S. aureus recovered from CSA compared to SBA or MSA. Our data support the use of CSA in place of standard culture media for detection of S. aureus in heavily contaminated respiratory samples. PMID:15297498

  6. Comparison of the BBL CHROMagar Staph aureus agar medium to conventional media for detection of Staphylococcus aureus in respiratory samples.

    PubMed

    Flayhart, Diane; Lema, Clara; Borek, Anita; Carroll, Karen C

    2004-08-01

    Screening for Staphylococcus aureus has become routine in certain patient populations. This study is the first clinical evaluation of the BBL CHROMagar Staph aureus agar (CSA) medium (BD Diagnostics, Sparks, Md.) for detection of S. aureus in nasal surveillance cultures and in respiratory samples from cystic fibrosis (CF) patients. S. aureus colonies appear mauve on CSA. Other organisms are inhibited or produce a distinctly different colony color. S. aureus was identified from all media by slide coagulase, exogenous DNase, and mannitol fermentation assays. Susceptibility testing was performed using the agar dilution method. A total of 679 samples were evaluated. All samples were inoculated onto CSA. Nasal surveillance cultures were inoculated onto sheep blood agar (SBA) (BD Diagnostics), and samples from CF patients were inoculated onto mannitol salt agar (MSA) (BD Diagnostics). Of the 679 samples cultured, 200 organisms produced a mauve color on CSA (suspicious for S. aureus) and 180 were positive for S. aureus on SBA or MSA. Of 200 CSA-positive samples 191 were identified as S. aureus. Nine mauve colonies were slide coagulase negative and were subsequently identified as Staphylococcus lugdunensis (one), Staphylococcus epidermidis (three), Staphylococcus haemolyticus (one), and Corynebacterium species (four). CSA improved the ability to detect S. aureus by recovering 12 S. aureus isolates missed by conventional media. Of the 192 S. aureus isolates recovered, 122 were methicillin susceptible and 70 were methicillin resistant. Overall, the sensitivity and specificity of CSA in this study were 99.5 and 98%, respectively. There was no difference in the performance of the slide coagulase test or in susceptibility testing performed on S. aureus recovered from CSA compared to SBA or MSA. Our data support the use of CSA in place of standard culture media for detection of S. aureus in heavily contaminated respiratory samples.

  7. Anti-Candida and anti-Cryptococcus antifungal produced by marine microorganisms.

    PubMed

    El Amraoui, B; El Amraoui, M; Cohen, N; Fassouane, A

    2014-12-01

    In order to search for antifungal from biological origin, we performed a screening of marine microorganisms isolated from seawater, seaweed, sediment and marine invertebrates collected from different coastal areas of the Moroccan Atlantic Ocean. The antifungal activities of these isolates were investigated against the pathogenic yeasts involved in medical mycology. Whole cultures of 34 marine microorganisms were screened for antifungal activities using the method of agar diffusion against four yeasts. The results showed that among the 34 isolates studied, 13 (38%) strains have antifungal activity against at least one out of four yeast species, 11 isolates have anti-Candida albicans CIP 48.72 activity, 12 isolates have anti-C. albicans CIP 884.65 activity, 13 isolates have anti-Cryptococcus neoformans activity and only 6 isolates are actives against Candida tropicalis R2 resistant to nystatin and amphotericin B. Nine isolates showed strong fungicidal activity. Fourteen microorganisms were identified and assigned to the genera Acinetobacter, Aeromonas, Alcaligenes, Bacillus, Chromobacterium, Enterococcus, Pantoea, and Pseudomonas. Due to a competitive role for space and nutrient, the marine microorganisms could produce more antimicrobials; therefore these marine microorganisms were expected to be potential resources of natural products such as those we research: anti-Candida and anti-Cryptococcus fungicides.

  8. Application of antifungal CFB to increase the durability of cement mortar.

    PubMed

    Park, Jong-Myong; Park, Sung-Jin; Kim, Wha-Jung; Ghim, Sa-Youl

    2012-07-01

    Antifungal cement mortar or microbiological calcium carbonate precipitation on cement surface has been investigated as functional concrete research. However, these research concepts have never been fused with each other. In this study, we introduced the antifungal calciteforming bacteria (CFB) Bacillus aryabhattai KNUC205, isolated from an urban tunnel (Daegu, South Korea). The major fungal deteriogens in urban tunnel, Cladosporium sphaerospermum KNUC253, was used as a sensitive fungal strain. B. aryabhattai KNUC205 showed CaCO3 precipitation on B4 medium. Cracked cement mortar pastes were made and neutralized by modified methods. Subsequently, the mixture of B. aryabhattai KNUC205, conidiospore of C. sphaerospermum KNUC253, and B4 agar was applied to cement cracks and incubated at 18 degrees C for 16 days. B. aryabhattai KNUC205 showed fungal growth inhibition against C. sphaerospermum. Furthermore, B. aryabhattai KNUC205 showed crack remediation ability and water permeability reduction of cement mortar pastes. Taken together, these results suggest that the CaCO3 precipitation and antifungal properties of B. aryabhattai KNUC205 could be used as an effective sealing or coating material that can also prevent deteriorative fungal growth. This study is the first application and evaluation research that incorporates calcite formation with antifungal capabilities of microorganisms for an environment-friendly and more effective protection of cement materials. In this research, the conception of microbial construction materials was expanded.

  9. Agar/collagen membrane as skin dressing for wounds.

    PubMed

    Bao, Lei; Yang, Wei; Mao, Xuan; Mou, Shansong; Tang, Shunqing

    2008-12-01

    Agar, a highly hydrophilic polymer, has a special gel property and favorable biocompatibility, but moderate intension strength in an aqueous condition and a low degradation rate. In order to tailor both properties of mechanical intension and degradation, type I collagen was composited with agar in a certain ratio by drying at 50 degrees C or by a freeze-dry process. Glutaraldehyde was chosen as a crosslinking agent, and the most favorable condition for crosslinking was that the weight ratio of agar to glutaraldehyde was 66.7 and the pH value about 5. Dynamic mechanical analysis results showed that the single agar membrane had a modulus value between 640 MPa and 1064 MPa, but it was between 340 MPa and 819 MPa after being composited with type I collagen. It was discovered under an optical microscope that the pores were interconnected in the composite scaffolds instead of the honeycomb-like pores in a single type I collagen scaffold or the laminated gaps in a single agar scaffold. The results of an acute toxicity test disclosed that the composites were not toxic to mice although the composites were crosslinked with a certain concentration of glutaraldehyde. The results of gross examinations showed that when the composite membranes or scaffolds were applied to a repair rabbit skin lesion, the composites had a good repair effect without infection, liquid exudation or visible scar in the lesion covered with them. But in the control group, the autologous skin showed necrosis and there were a lot of scar tissues in the lesion site. H&E staining results showed that the repair tissue was similar to the normal one and very few scaffolds or membranes were left without degradation after 2 or 3 weeks. In conclusion, it is proved that type I collagen increases the toughness of the agar membrane, and the agar/type I collagen composites are promising biomaterials as wound dressings for healing burns or ulcers.

  10. 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. PMID:27474467

  11. Natamycin as a selective antifungal agent in media for growth of Legionella spp.

    PubMed Central

    Edelstein, P H; Edelstein, M A

    1996-01-01

    The growth of 18 different Legionella sp. strains and 76 different yeast isolates was tested on buffered charcoal yeast extract medium supplemented with alpha-ketoglutarate (BCYE alpha medium) and with natamycin, an antifungal agent. Bacterial growth was no different on BCYE alpha medium made with or without natamycin, whereas complete inhibition of yeasts occurred in BCYE alpha medium containing 200 to 500 micrograms of natamycin per ml. Selective BCYE alpha media made with natamycin rather than anisomycin had no (formulation with vancomycin, polymyxin B, and agar) or little (formulation with cefamandole, polymyxin B, and agar) inhibitory effect on the growth of 14 different Legionella sp. bacteria. Natamycin is an inexpensive alternative to anisomycin in the formulation of selective BCYE alpha media. PMID:8748300

  12. Antifungal activity of topical microemulsion containing a thiophene derivative

    PubMed Central

    Guimarães, Geovani Pereira; de Freitas Araújo Reis, Mysrayn Yargo; da Silva, Dayanne Tomaz Casimiro; Junior, Francisco Jaime Bezerra Mendonça; Converti, Attílio; Pessoa, Adalberto; de Lima Damasceno, Bolívar Ponciano Goulart; da Silva, José Alexsandro

    2014-01-01

    Fungal infections have become a major problem of worldwide concern. Yeasts belonging to the Candida genus and the pathogenic fungus Cryptococcus neoformans are responsible for different clinical manifestations, especially in immunocompromised patients. Antifungal therapies are currently based on a few chemotherapeutic agents that have problems related to effectiveness and resistance profiles. Microemulsions are isotropic, thermodynamically stable transparent systems of oil, water and surfactant that can improve the solubilization of lipophilic drugs. Taking into account the need for more effective and less toxic drugs along with the potential of thiophene derivatives as inhibitors of pathogenic fungi growth, this study aimed to evaluate the antifungal activity of a thiophene derivative (5CN05) embedded in a microemulsion (ME). The minimum inhibitory concentration (MIC) was determined using the microdilution method using amphotericin B as a control. The formulations tested (ME- blank and ME-5CN05) showed physico-chemical properties that would allow their use by the topical route. 5CN05 as such exhibited moderate or weak antifungal activity against Candida species (MIC = 270–540 μg.mL−1) and good activity against C. neoformans (MIC = 17 μg.mL−1). Candida species were susceptible to ME-5CN05 (70–140 μg.mL−1), but C. neoformans was much more, presenting a MIC value of 2.2 μg.mL−1. The results of this work proved promising for the pharmaceutical industry, because they suggest an alternative therapy against C. neoformans. PMID:25242940

  13. Antifungal and antibacterial activities of Streptomyces polymachus sp. nov. isolated from soil.

    PubMed

    Nguyen, Tuan Manh; Kim, Jaisoo

    2015-08-01

    Strain T258T was isolated from forest soil at Bongnae Falls, South Korea. The strain exhibited antimicrobial and antifungal activity against the following strains: Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Paenibacillus larvae, Escherichia coli, Candida albicans and Aspergillus niger. Growth occurred on all ISP media tested (2, 3, 4, 5, 6 and 7), Czapek-Dox agar, potato dextrose agar, trypticase soy agar, Bennett's modified agar and nutrient agar at 28 °C. Aerial spores were produced solely on ISP Medium 4; the colour of the aerial mycelium was white and the substrate mycelium was ivory. Melanin production was negative on peptone-yeast extract iron agar (ISP Medium 6). The cell-wall peptidoglycan contained ll-diaminopimelic acid, glutamic acid, alanine and glycine. Whole-cell hydrolysates contained glucose, ribose and galactose. The predominant menaquinones were MK-9(H6) and MK-9(H8) while the minor menaquinone was MK-10(H2). The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids (>10%) were C16 : 0 (29.8%), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (15.1%), anteiso-C15 : 0 (13.5%) and iso-C15 : 0 (10.3%). DNA-DNA similarity with other strains ranged between 37.84 ± 1.15% and 50.25 ± 1.91 %. On the basis of these data, we suggest that strain T258T represents a novel species that belong to the genus Streptomyces, for which we propose a name Streptomyces polymachus sp. nov. The type strain is T258T ( = KACC 18247T = KEMB 9005-212T = NBRC 110905T). PMID:25899502

  14. Antifungal and antibacterial activities of Streptomyces polymachus sp. nov. isolated from soil.

    PubMed

    Nguyen, Tuan Manh; Kim, Jaisoo

    2015-08-01

    Strain T258T was isolated from forest soil at Bongnae Falls, South Korea. The strain exhibited antimicrobial and antifungal activity against the following strains: Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Paenibacillus larvae, Escherichia coli, Candida albicans and Aspergillus niger. Growth occurred on all ISP media tested (2, 3, 4, 5, 6 and 7), Czapek-Dox agar, potato dextrose agar, trypticase soy agar, Bennett's modified agar and nutrient agar at 28 °C. Aerial spores were produced solely on ISP Medium 4; the colour of the aerial mycelium was white and the substrate mycelium was ivory. Melanin production was negative on peptone-yeast extract iron agar (ISP Medium 6). The cell-wall peptidoglycan contained ll-diaminopimelic acid, glutamic acid, alanine and glycine. Whole-cell hydrolysates contained glucose, ribose and galactose. The predominant menaquinones were MK-9(H6) and MK-9(H8) while the minor menaquinone was MK-10(H2). The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids (>10%) were C16 : 0 (29.8%), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (15.1%), anteiso-C15 : 0 (13.5%) and iso-C15 : 0 (10.3%). DNA-DNA similarity with other strains ranged between 37.84 ± 1.15% and 50.25 ± 1.91 %. On the basis of these data, we suggest that strain T258T represents a novel species that belong to the genus Streptomyces, for which we propose a name Streptomyces polymachus sp. nov. The type strain is T258T ( = KACC 18247T = KEMB 9005-212T = NBRC 110905T).

  15. Blood agar and Mycobacterium tuberculosis: the end of a dogma.

    PubMed

    Drancourt, M; Carrieri, P; Gévaudan, M-J; Raoult, D

    2003-04-01

    Incidental blood agar-based recovery of Mycobacterium tuberculosis led us to further investigate this routine medium for primary isolation and culture of M. tuberculosis. Fifteen respiratory tract and eight lymph node Ziehl-Neelsen-positive specimens were inoculated in parallel into tubes containing egg-based medium and 5% sheep blood agar. Colonies appeared sooner on this medium than on the egg-based medium, but this difference was not significant (P = 0.11, analysis of variance [ANOVA] test). Further experiments compared the growth of 38 respiratory and lymph node M. tuberculosis isolates when subcultured on the two media. After 6 days of incubation, 21 of 38 isolates had grown on blood agar, and the mean number of colonies was significantly greater on blood agar than on the egg-based medium (P < 0 0.001, ANOVA test). These results demonstrate that M. tuberculosis grows easily on blood agar within 1to 2 weeks, indicating that this basic medium is suitable for laboratory diagnosis of tuberculosis in addition to other media. Laboratories that routinely use prolonged incubations of blood plates, for example, for the recovery of Bartonella species, should consider the potential safety implications of encountering this highly infectious pathogen.

  16. Evaluation of the OSIRIS video reader as an automated measurement system for the agar disk diffusion technique.

    PubMed

    Kolbert, M; Chegrani, F; Shah, P M

    2004-05-01

    Measurement of inhibition zones by the automated OSIRIS system was compared with manual measurement. In total, 14 176 measurements were made with 352 staphylococcal and 80 Enterobacteriaceae isolates, involving four panels of antibiotics on round and square Mueller-Hinton agar plates, according to the German DIN 58940 recommendations. Variations of +/- 3 mm in zone size measurements were defined as tolerable. Very major errors (i.e., classification of a resistant isolate as susceptible by the OSIRIS system) occurred in < 1% of tests. With staphylococci, the best concordance was recorded for rifampicin (91.3%), moxifloxacin (88.1%), and gentamicin (86.3%), while the concordance on square plates for vancomycin, pristinamycin and kanamycin was 97.2%, 96.1% and 96.0%, respectively. The poorest concordance was for cefuroxime (43.7%) and novobiocin (47.0%) on round plates, and fosfomycin (36.5%) and chloramphenicol (84.0%) on square plates. With Enterobacteriaceae, 100% concordance was recorded for ampicillin, gentamicin and ciprofloxacin on round agar plates, and for gentamicin, cefoxitin and nalidixic acid on square plates. The poorest results were recorded for nalidixic acid (32.5%) and piperacillin (82.5%) on round plates, and for nitrofurantoin (72.5%) and amoxycillin (82.5%) on square plates. It was concluded that the OSIRIS system was a rapid and reliable system for measuring disk susceptibility test results on round and square agar plates.

  17. Photothermal characterization of the gelation process in Gelidium robustum Agar

    NASA Astrophysics Data System (ADS)

    Freile-Pelegrín, Y.; Bante, J.; Alvarado-Gil, J. J.; Yánez-Limón, J. M.

    2005-06-01

    Agar is a hydrophilic colloid formed by polysaccharides, whose ability to form reversible gels simply by cooling hot aqueous solutions is the most important property and can be regarded as the prototype and model for all gelling systems. In this paper the evolution of the gelation process of agar obtained from algae of the species Gelidium robustum, using the photopyroelectric technique is reported. It is shown that thermal effusivity increase when the agar is cooled, reaching a maximum value around 37°C. The increase in thermal effusivity can be related to the increasing of the bondings in the gel as temperature decreases, reaching the maximum at the gelation point. The decrease of the thermal effusivity at lower temperature could be due to the syneresis process involving a gradual release of water after gelation.

  18. Fly agaric (Amanita muscaria) poisoning, case report and review.

    PubMed

    Satora, Leszek; Pach, Dorota; Butryn, Beata; Hydzik, Piotr; Balicka-Slusarczyk, Barbara

    2005-06-01

    Gathering and eating mushrooms and other plants containing psychoactive substances has become increasingly popular among young people experimenting with drugs. Dried fly agaric Amanita muscaria fruiting bodies were eaten by five young persons (18-21 years of age) at a party in order to evoke hallucinations. Visual and auditory hallucinations occurred in four of them, whereas a 18-year-old girl lost consciousness. The following morning, she went to the Clinic of Toxicology. Due to the fact that not all the active substances present in the fly agaric have been identified, and some of them have an effect after a period of latency, the patient was admitted for several days of observation during which check-up examinations were performed. After four days without any problems, she was discharged. The poisoning regressed with no organ complications. The remaining persons who had eaten the fly agaric were free from any complaints. PMID:15904689

  19. Antifungal activity against Candida albicans of starch Pickering emulsion with thymol or amphotericin B in suspension and calcium alginate films.

    PubMed

    Cossu, Andrea; Wang, Min S; Chaudhari, Amol; Nitin, Nitin

    2015-09-30

    Conventional antifungal treatments against Candida albicans in the oral cavity often result in increased cytotoxicity. The goal of this study was to determine the potential of starch Pickering emulsion as a delivery vehicle for an antifungal natural phenolic compound such as thymol in simulated saliva fluid (SSF) compared to amphotericin B. An oil-in-water (o/w) emulsion was stabilized using starch particles. Physical stability of the emulsion and disruption induced by α-amylase activity in SSF was evaluated. Encapsulated thymol in o/w emulsion was compared to encapsulated amphotericin B for antifungal activity against C. albicans in suspension using emulsions or zone inhibition assay on agar plates using emulsions dispersed in alginate films. Results showed that the emulsions were stable for at least three weeks. Digestion of the emulsion by α-amylase led to coalescence of emulsion droplets. The antifungal activity of thymol and amphotericin B in emulsion formulation was enhanced upon incubation with α-amylase. Results from the zone inhibition assay demonstrated efficacy of the emulsions dispersed in alginate films. Interestingly, addition of α-amylase to the alginate films resulted in a decreased inhibitory effect. Overall, this study showed that starch Pickering emulsions have a potential to deliver hydrophobic antifungal compounds to treat oral candidiasis. PMID:26231107

  20. Antifungal activity against Candida albicans of starch Pickering emulsion with thymol or amphotericin B in suspension and calcium alginate films.

    PubMed

    Cossu, Andrea; Wang, Min S; Chaudhari, Amol; Nitin, Nitin

    2015-09-30

    Conventional antifungal treatments against Candida albicans in the oral cavity often result in increased cytotoxicity. The goal of this study was to determine the potential of starch Pickering emulsion as a delivery vehicle for an antifungal natural phenolic compound such as thymol in simulated saliva fluid (SSF) compared to amphotericin B. An oil-in-water (o/w) emulsion was stabilized using starch particles. Physical stability of the emulsion and disruption induced by α-amylase activity in SSF was evaluated. Encapsulated thymol in o/w emulsion was compared to encapsulated amphotericin B for antifungal activity against C. albicans in suspension using emulsions or zone inhibition assay on agar plates using emulsions dispersed in alginate films. Results showed that the emulsions were stable for at least three weeks. Digestion of the emulsion by α-amylase led to coalescence of emulsion droplets. The antifungal activity of thymol and amphotericin B in emulsion formulation was enhanced upon incubation with α-amylase. Results from the zone inhibition assay demonstrated efficacy of the emulsions dispersed in alginate films. Interestingly, addition of α-amylase to the alginate films resulted in a decreased inhibitory effect. Overall, this study showed that starch Pickering emulsions have a potential to deliver hydrophobic antifungal compounds to treat oral candidiasis.

  1. A Prototype Antifungal Contact Lens

    PubMed Central

    Ciolino, Joseph B.; Hudson, Sarah P.; Mobbs, Ashley N.; Hoare, Todd R.; Iwata, Naomi G.; Fink, Gerald R.

    2011-01-01

    Purpose. To design a contact lens to treat and prevent fungal ocular infections. Methods. Curved contact lenses were created by encapsulating econazole-impregnated poly(lactic-co-glycolic) acid (PLGA) films in poly(hydroxyethyl methacrylate) (pHEMA) by ultraviolet photopolymerization. Release studies were conducted in phosphate-buffered saline at 37°C with continuous shaking. The contact lenses and their release media were tested in an antifungal assay against Candida albicans. Cross sections of the pre- and postrelease contact lenses were characterized by scanning electron microscopy and by Raman spectroscopy. Results. Econazole-eluting contact lenses provided extended antifungal activity against Candida albicans fungi. Fungicidal activity varied in duration and effectiveness depending on the mass of the econazole-PLGA film encapsulated in the contact lens. Conclusions. An econazole-eluting contact lens could be used as a treatment for fungal ocular infections. PMID:21527380

  2. Growth of Desulfovibrio on the Surface of Agar Media

    PubMed Central

    Iverson, Warren P.

    1966-01-01

    Growth of Desulfovibrio desulfuricans (API strain) was found to take place in an atmosphere of hydrogen on the agar surface of complex media, including yeast extract (Difco), and Trypticase Soy Agar (BBL) without any added reducing agents. For growth on a 2% yeast extract-agar surface in the absence of hydrogen (nitrogen atmosphere), sodium lactate was required in the medium. Growth on the surface of Trypticase Soy Agar (TSA) under nitrogen took place readily in the absence of an added hydrogen donor. A medium (TSA plus salts) is described based upon the addition of sodium lactate (4 ml per liter), magnesium sulfate (2 g per liter), and ferrous ammonium sulfate (0.05%) to TSA, which appears suitable for the isolation and growth of Desulfovibrio on the surface of agar plates in an atmosphere of hydrogen. Sodium lactate does not appear to be essential in this medium for good growth and sulfate reduction in a hydrogen atmosphere, but is essential in a nitrogen atmosphere. Growth of Desulfovibrio (hydrogen atmosphere) on the agar surface of media commonly used for its cultivation as well as on an inorganic medium containing bicarbonate as a source of carbon is poor and erratic unless inoculated (Desulfovibrio) plates of TSA plus salts are incubated in the same container with plates of these media. This stimulatory effect of incubation with inoculated plates of TSA plus salts medium appears to be due to as yet unidentified volatile material produced by D. desulfuricans when growing on this medium. Another volatile material, or possibly the identical material, appears to act similarly to a hydrogen donor. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:5955798

  3. Method for Measuring Changes in Surface Tension on Agar

    PubMed Central

    Weisberg, David S.; Dworkin, Martin

    1983-01-01

    The surface tension of agar surfaces was determined by measuring the contact angles formed by drops of various hydrophobic liquids on the surface and then calculating the composite surface free energy function by solving a series of simultaneous equations derived from these data. This method was used to measure the change in the surface tension of agar produced by the addition of various concentrations of albumin. The resulting curve was typical of the effect of increasing concentrations of surfactants on surface tension. The method was compared with other methods of determining surface tension of solids, and it was concluded that the technique used here provided the most reliable results. PMID:16346273

  4. Defensins: antifungal lessons from eukaryotes

    PubMed Central

    Silva, Patrícia M.; Gonçalves, Sónia; Santos, Nuno C.

    2014-01-01

    Over the last years, antimicrobial peptides (AMPs) have been the focus of intense research toward the finding of a viable alternative to current antifungal drugs. Defensins are one of the major families of AMPs and the most represented among all eukaryotic groups, providing an important first line of host defense against pathogenic microorganisms. Several of these cysteine-stabilized peptides present a relevant effect against fungi. Defensins are the AMPs with the broader distribution across all eukaryotic kingdoms, namely, Fungi, Plantae, and Animalia, and were recently shown to have an ancestor in a bacterial organism. As a part of the host defense, defensins act as an important vehicle of information between innate and adaptive immune system and have a role in immunomodulation. This multidimensionality represents a powerful host shield, hard for microorganisms to overcome using single approach resistance strategies. Pathogenic fungi resistance to conventional antimycotic drugs is becoming a major problem. Defensins, as other AMPs, have shown to be an effective alternative to the current antimycotic therapies, demonstrating potential as novel therapeutic agents or drug leads. In this review, we summarize the current knowledge on some eukaryotic defensins with antifungal action. An overview of the main targets in the fungal cell and the mechanism of action of these AMPs (namely, the selectivity for some fungal membrane components) are presented. Additionally, recent works on antifungal defensins structure, activity, and cytotoxicity are also reviewed. PMID:24688483

  5. Antibacterial and Antifungal Compounds from Marine Fungi

    PubMed Central

    Xu, Lijian; Meng, Wei; Cao, Cong; Wang, Jian; Shan, Wenjun; Wang, Qinggui

    2015-01-01

    This paper reviews 116 new compounds with antifungal or antibacterial activities as well as 169 other known antimicrobial compounds, with a specific focus on January 2010 through March 2015. Furthermore, the phylogeny of the fungi producing these antibacterial or antifungal compounds was analyzed. The new methods used to isolate marine fungi that possess antibacterial or antifungal activities as well as the relationship between structure and activity are shown in this review. PMID:26042616

  6. A rapid detection of multidrug-resistant Mycobacterium tuberculosis by a nitrate reductase assay on blood agar.

    PubMed

    Coban, Ahmet Yilmaz; Cayci, Yeliz Tanriverdi; Deveci, Aydin; Akgunes, Alper; Uzun, Meltem; Durupinar, Belma

    2011-05-01

    The susceptibility of 49 Mycobacterium tuberculosis clinical isolates to isoniazid (INH) and rifampisin (RIF) (28 multi-drug resistant-tuberculosis samples) was determined by a nitrate reductase assay (NRA) on blood agar. Agreement between the NRA and other testing methods was found to be 93.8% for both INH and RIF. The sensitivity, specificity, positive predictive value and negative predictive value for INH were 92.8%, 94.2%, 86.6% and 97%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value for RIF were 90.4%, 96.4%, 95% and 93.1%. In conclusion, we show here that blood agar can be used effectively for the NRA test.

  7. Is blood agar an alternative to sabouraud dextrose agar for the isolation of fungi in patients with mycotic keratitis.

    PubMed

    Reddy, Ashok Kumar; Brahmaiah, Upputuri; Narayen, Nitesh; Reddy, Ravi Kumar; Reddy, Rupak Kumar; Chitta, Meghraj; Prasad, Srinivas; Swarup, Rishi; Mohiuddin, Syed Maaz; Reddy, Madhukar; Aasuri, Murali K; Murthy, B S R; Bhide, Milind; Ahmed, Sajid

    2013-06-01

    To compare the blood agar (BA), sabouraud dextrose agar (SDA) and chocolate agar (CA) for the isolation of fungi in patients with mycotic keratitis. Corneal Scrapings of 229 patients with clinically diagnosed microbial keratitis were inoculated on BA, SDA, CA. The culture media were evaluated for the rate and time taken for the fungal growth. Seventy six of 229 patients had fungal keratitis. Fungus grew on BA in 60/76(78.9 %), on SDA in 76/76 (100 %), on CA in 40/76(52.6 %) patients. The fungi which grew on BA (60/76) also grown on SDA at the same time. The colony morphologies of different fungi were better on SDA than BA/CA. Among the different culture media, SDA is essential for the isolation fungi in patients with mycotic keratitis.

  8. Topical antifungals for seborrhoeic dermatitis

    PubMed Central

    Okokon, Enembe O; Verbeek, Jos H; Ruotsalainen, Jani H; Ojo, Olumuyiwa A; Bakhoya, Victor Nyange

    2015-01-01

    Background Seborrhoeic dermatitis is a chronic inflammatory skin condition that is distributed worldwide. It commonly affects the scalp, face and flexures of the body. Treatment options include antifungal drugs, steroids, calcineurin inhibitors, keratolytic agents and phototherapy. Objectives To assess the effects of antifungal agents for seborrhoeic dermatitis of the face and scalp in adolescents and adults. A secondary objective is to assess whether the same interventions are effective in the management of seborrhoeic dermatitis in patients with HIV/AIDS. Search methods We searched the following databases up to December 2014: the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 11), MEDLINE (from 1946), EMBASE (from 1974) and Latin American Caribbean Health Sciences Literature (LILACS) (from 1982). We also searched trials registries and checked the bibliographies of published studies for further trials. Selection criteria Randomised controlled trials of topical antifungals used for treatment of seborrhoeic dermatitis in adolescents and adults, with primary outcome measures of complete clearance of symptoms and improved quality of life. Data collection and analysis Review author pairs independently assessed eligibility for inclusion, extracted study data and assessed risk of bias of included studies. We performed fixed-effect meta-analysis for studies with low statistical heterogeneity and used a random-effects model when heterogeneity was high. Main results We included 51 studies with 9052 participants. Of these, 45 trials assessed treatment outcomes at five weeks or less after commencement of treatment, and six trials assessed outcomes over a longer time frame. We believe that 24 trials had some form of conflict of interest, such as funding by pharmaceutical companies. Among the included studies were 12 ketoconazole trials (N = 3253), 11 ciclopirox trials (N = 3029), two lithium trials (N = 141

  9. Evaluation of Brilliance ESBL agar, a novel chromogenic medium for detection of extended-spectrum-beta- lactamase-producing Enterobacteriaceae.

    PubMed

    Huang, Te-Din; Bogaerts, Pierre; Berhin, Catherine; Guisset, Amelie; Glupczynski, Youri

    2010-06-01

    The aim of this study was to evaluate the performance of Brilliance ESBL agar (OX; Oxoid, Basingstoke, United Kingdom), a novel chromogenic agar for the selective isolation and the presumptive identification of extended-spectrum-beta-lactamase (ESBL)-producing Enterobacteriaceae. A panel of 200 clinical Gram-negative Enterobacteriaceae and nonfermenting isolates with defined resistance mechanisms was inoculated onto OX and onto ChromID ESBL agar (BM; bioMérieux, Marcy l'Etoile, France) chromogenic medium in the first part of the study to evaluate the growth selectivity and chromogenic features of these two media. Of the 156 Enterobacteriaceae challenge isolates, 8 fully susceptible isolates were inhibited, all 98 ESBL producers were detected, and 50 isolates harboring other resistance mechanisms were recovered on both chromogenic agars. In the second phase, 528 clinical samples (including 344 fecal specimens) were plated onto OX, BM, and MacConkey agar with a ceftazidime disk (MCC) for the screening of ESBL-producing Enterobacteriaceae. Growth on at least one medium was observed with 144 (27%) of the clinical samples screened. A total of 182 isolates, including 109 (60%) of Enterobacteriaceae, were recovered and 70 of these (from 59 specimens) were confirmed as ESBL-producing isolates. The sensitivities of MCC, BM, and OX were 74.6%, 94.9%, and 94.9%, respectively. The specificities of MCC, BM, and OX by specimens reached 94.9%, 95.5%, and 95.7%, respectively, when only colored colonies were considered on the two selective chromogenic media. The high negative predictive value (99.3%) found for OX suggests that this medium may constitute an excellent screening tool for the rapid exclusion of patients not carrying ESBL producers.

  10. Susceptibility of Pittsburgh pneumonia agent (Legionella micdadei) and other newly recognized members of the genus Legionella to nineteen antimicrobial agents.

    PubMed Central

    Pasculle, A W; Dowling, J N; Weyant, R S; Sniffen, J M; Cordes, L G; Gorman, G M; Feeley, J C

    1981-01-01

    The susceptibilities of 11 strains representing the five recognized species of Legionella were determined by agar dilution testing on buffered charcoal-yeast extract agar. All of the legionellae tested were susceptible to rifampin, erythromycin, rosaramycin, chloramphenicol, and the aminoglycosides and were resistant to clindamycin and vancomycin. Susceptibilities to penicillins and cephalosporins were variable. Legionella micdadei, Legionella bozemanii, and Legionella gormanii were susceptible to these agents, but minimal inhibitory concentrations for each species were different. Legionella dumoffii resembled Legionella pneumophila in being resistant to penicillin, cephalothin, and cephamandole and susceptible to moxalactam and cefoxitin. All species except L. micdadei produced beta-lactamase. PMID:7325645

  11. Recovery of Sublethally Injured Bacteria Using Selective Agar Overlays.

    ERIC Educational Resources Information Center

    McKillip, John L.

    2001-01-01

    This experiment subjects bacteria in a food sample and an environmental sample to conditions of sublethal stress in order to assess the effectiveness of the agar overlay method to recover sublethally injured cells compared to direct plating onto the appropriate selective medium. (SAH)

  12. Fusobacterium necrophorum- detection and identification on a selective agar.

    PubMed

    Bank, Steffen; Nielsen, Hanne Merete; Mathiasen, Boris Hoyer; Leth, Dorte Christiansen; Kristensen, Lena Hagelskjaer; Prag, Jørgen

    2010-12-01

    Within the last decade, Fusobacterium necrophorum subsp. funduliforme has been considered a clinically important pathogen causing pharyngitis especially in adolescents and young adults. F. necrophorum pharyngitis can progress into Lemierre's syndrome, which is a severe and life-threatening infection. However, throat swabs are not cultured anaerobically in the routine and even if cultured anaerobically, it can be difficult to identify F. necrophorum from the normal flora of the throat. F. necrophorum is therefore often overlooked as the cause of pharyngitis. In our laboratory, a F. necrophorum selective agar has been developed containing vancomycin and nalidixin, which inhibit the growth of most Gram-positive and many Gram-negative bacteria, respectively. β-haemolysis of horse blood can be detected, which further facilitates the detection and identification of F. necrophorum. The F. necrophorum selective agar was evaluated against a quantitative real-time polymerase chain reaction assay and shown to have a significantly higher sensitivity for detecting F. necrophorum than the anaerobic agar commonly used in Denmark. Furthermore, the F. necrophorum selective agar does not require experienced laboratory technicians, require fewer subcultures, is probably less expensive and is faster to perform than other culture methods.

  13. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  14. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  15. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  16. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  17. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  18. Improving agar electrospinnability with choline-based deep eutectic solvents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One percent agar (% wt) was dissolved in the deep eutectic solvent (DES), (2-hydroxyethyl) trimethylammonium chloride/urea at a 1:2 molar ratio, and successfully electrospun into nanofibers. An existing electrospinning set-up, operated at 50 deg C, was adapted for use with an ethanol bath to collect...

  19. Growth kinetics of three species of Tetrahymena on solid agar

    SciTech Connect

    Dobra, K.W.; McArdle, E.W.; Ehret, C.F.

    1980-01-01

    A nutrient-agar method without liquid overlay has been developed for cultivation of ciliates. Three species of Tetrahymena-T. pyriformis strain W, T. rostrata strain UNI, and T. vorax strain V/sub 2/S, representing the 3 main groups of Tetrahymena species, were used; however the method should apply to other ciliates. Growth on the surface of the agar was facilitated by an optimal surface-to-volume ratio yielding a high density of ciliates and short generation times. At the highest density achieved, the cells became irregularly hexagonal and formed a monolayer tissue on the agar. Ciliates grown on agar were like those in liquid culture, typical oral ciliature, food-vacuole formation, and typical cortical patterns being retained. Advantages of this method include high cell density, easy recovery, and optimal O/sub 2/ supply. The organisms can also be cultivated on the surface of sterile cellulose-nitrate filters, facilitating in situ fixation and staining as well as transfer into different media by transfer of filters with cells, without prior centrifugation and resuspension.

  20. Screening of Pharmacologically Active Small Molecule Compounds Identifies Antifungal Agents Against Candida Biofilms

    PubMed Central

    Watamoto, Takao; Egusa, Hiroshi; Sawase, Takashi; Yatani, Hirofumi

    2015-01-01

    Candida species have emerged as important and common opportunistic human pathogens, particularly in immunocompromised individuals. The current antifungal therapies either have toxic side effects or are insufficiently effect. The aim of this study is develop new small-molecule antifungal compounds by library screening methods using Candida albicans, and to evaluate their antifungal effects on Candida biofilms and cytotoxic effects on human cells. Wild-type C. albicans strain SC5314 was used in library screening. To identify antifungal compounds, we screened a small-molecule library of 1,280 pharmacologically active compounds (LOPAC1280TM) using an antifungal susceptibility test (AST). To investigate the antifungal effects of the hit compounds, ASTs were conducted using Candida strains in various growth modes, including biofilms. We tested the cytotoxicity of the hit compounds using human gingival fibroblast (hGF) cells to evaluate their clinical safety. Only 35 compounds were identified by screening, which inhibited the metabolic activity of C. albicans by >50%. Of these, 26 compounds had fungistatic effects and nine compounds had fungicidal effects on C. albicans. Five compounds, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate, ellipticine and CV-3988, had strong fungicidal effects and could inhibit the metabolic activity of Candida biofilms. However, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate and ellipticine were cytotoxic to hGF cells at low concentrations. CV-3988 showed no cytotoxicity at a fungicidal concentration. Four of the compounds identified, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate and ellipticine, had toxic effects on Candida strains and hGF cells. In contrast, CV-3988 had fungicidal effects on Candida strains, but low cytotoxic effects on hGF cells. Therefore, this screening reveals agent, CV-3988 that was previously unknown to be antifungal agent, which could be a novel therapies for superficial mucosal candidiasis. PMID

  1. Evaluation of use of a new chromogenic agar in detection of urinary tract pathogens.

    PubMed

    Samra, Z; Heifetz, M; Talmor, J; Bain, E; Bahar, J

    1998-04-01

    CHROMagar Orientation, a new chromogenic medium, was evaluated for the detection and differentiation of gram-positive and gram-negative pathogenic microorganisms in 900 urine samples from hospitalized patients. Performance characteristics of the medium were evaluated in comparison to those of 5% sheep blood and MacConkey agars by direct inoculation of the urine samples on the three media. Four gram-negative and two gram-positive strains as well as one yeast control strain from the American Type Culture Collection were used to ensure quality control. CHROMagar Orientation succeeded in detecting all the urine pathogens that were detected by the reference media, including gram-negative bacilli, staphylococci, streptococci, and yeasts. Colony color and morphology on CHROMagar Orientation accurately differentiated Escherichia coli, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, and Acinetobacter spp. Owing to the similarity in the pigmentation produced by Klebsiella, Enterobacter, and Citrobacter isolates, the medium failed to distinguish among them; however, these isolates were easily recognized as coliforms because of their metallic blue coloration. Staphylococci were clearly perceptible: S. aureus and S. epidermidis grow in regular-size colonies that range from opaque white to yellowish, and S. saprophyticus produces opaque pink colonies. All streptococcus strains, including those from groups B and C, were detected. They grow as undifferentiated flat dry diffused colonies, and additional tests were required for identification. Enterococci were easily discriminated by their strong turquoise pigmentation and their typical growth on the agar's surface. Yeast grow in typical creamy wet convex colonies. The accuracy of antibiotic susceptibility determinations according to standard methods was also tested by picking isolates directly from CHROMagar Orientation. The results showed excellent correlation with those obtained with microorganisms picked from

  2. 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. PMID:24506036

  3. Antifungal property of hibicuslide C and its membrane-active mechanism in Candida albicans.

    PubMed

    Hwang, Ji Hong; Jin, Qinglong; Woo, Eun-Rhan; Lee, Dong Gun

    2013-10-01

    In this study, the antifungal activity and mode of action(s) of hibicuslide C derived from Abutilon theophrasti were investigated. Antifungal susceptibility testing showed that hibicuslide C possessed potent activities toward various fungal strains and less hemolytic activity than amphotericin B. To understand the antifungal mechanism(s) of hibicuslide C in Candida albicans, flow cytometric analysis with propidium iodide was done. The results showed that hibicuslide C perturbed the plasma membrane of the C. albicans. The analysis of the transmembrane electrical potential with 3,3'-dipropylthiacarbocyanine iodide [DiSC3(5)] indicated that hibicuslide C induced membrane depolarization. Furthermore, model membrane studies were performed with calcein encapsulating large unilamellar vesicles (LUVs) and FITC-dextran (FD) loaded LUVs. These results demonstrated that the antifungal effects of hibicuslide C on the fungal plasma membrane were through the formation of pores with radii between 2.3 nm and 3.3 nm. Finally, in three dimensional flow cytometric contour plots, a reduced cell sizes by the pore-forming action of hibicuslide C were observed. Therefore, the present study suggests that hibicuslide C exerts its antifungal effect by membrane-active mechanism.

  4. Development of a selective agar plate for the detection of Campylobacter spp. in fresh produce.

    PubMed

    Yoo, Jin-Hee; Choi, Na-Young; Bae, Young-Min; Lee, Jung-Su; Lee, Sun-Young

    2014-10-17

    This study was conducted to develop a selective medium for the detection of Campylobacter spp. in fresh produce. Campylobacter spp. (n=4), non-Campylobacter (showing positive results on Campylobacter selective agar) strains (n=49) isolated from fresh produce, indicator bacteria (n=13), and spoilage bacteria isolated from fresh produce (n=15) were plated on four Campylobacter selective media. Bolton agar and modified charcoal cefoperazone deoxycholate agar (mCCDA) exhibited higher sensitivity for Campylobacter spp. than did Preston agar and Hunt agar, although certain non-Campylobacter strains isolated from fresh produce by using a selective agar isolation method, were still able to grow on Bolton agar and mCCDA. To inhibit the growth of non-Campylobacter strains, Bolton agar and mCCDA were supplemented with 5 antibiotics (rifampicin, polymyxin B, sodium metabisulfite, sodium pyruvate, ferrous sulfate) and the growth of Campylobacter spp. (n=7) and non-Campylobacter strains (n=44) was evaluated. Although Bolton agar supplemented with rifampicin (BR agar) exhibited a higher selectivity for Campylobacter spp. than did mCCDA supplemented with antibiotics, certain non-Campylobacter strains were still able to grow on BR agar (18.8%). When BR agar with various concentrations of sulfamethoxazole-trimethoprim were tested with Campylobacter spp. (n=8) and non-Campylobacter (n=7), sulfamethoxazole-trimethoprim was inhibitory against 3 of 7 non-Campylobacter strains. Finally, we validated the use of BR agar containing 50mg/L sulfamethoxazole (BRS agar) or 0.5mg/L ciprofloxacin (BRCS agar) and other selective agars for the detection of Campylobacter spp. in chicken and fresh produce. All chicken samples were positive for Campylobacter spp. when tested on mCCDA, BR agar, and BRS agar. In fresh produce samples, BRS agar exhibited the highest selectivity for Campylobacter spp., demonstrating its suitability for the detection of Campylobacter spp. in fresh produce.

  5. [Pattern of antimicrobial susceptibility of enterococci strains].

    PubMed

    Hoyos, A; Gutiérrez, J; Piédrola, G

    1995-04-01

    Enterococci resistance to antimicrobials has increased lately. We studied the susceptibility to 12 antimicrobials of 150 enterococci strains coming from hospitalized and outpatients, using the agar dilution method. Teicoplanin, followed by imipenem and amoxicilin-clavulanic acid had the lower minimal inhibitory concentrations. No strains of E faecalis was resistant to ampicillin, whereas 14% of E faecium had minimal inhibitory concentrations over 8 micrograms/ml. The high minimal inhibitory concentrations of cefpirome (64 micrograms/ml) renders this antimicrobial useless in the treatment of enterococcal infections. Betalactamase production and resistance to glucopeptides were not detected. Antimicrobial susceptibility of strains coming for hospitalized or outpatients were similar.

  6. Antifungal activity of extracts from Atacama Desert fungi against Paracoccidioides brasiliensis and identification of Aspergillus felis as a promising source of natural bioactive compounds

    PubMed Central

    Mendes, Graziele; Gonçalves, Vívian N; Souza-Fagundes, Elaine M; Kohlhoff, Markus; Rosa, Carlos A; Zani, Carlos L; Cota, Betania B; Rosa, Luiz H; Johann, Susana

    2016-01-01

    Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values≤ 125.0 µg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 µg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 µg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity. PMID:27008375

  7. Antifungal activity of extracts from Atacama Desert fungi against Paracoccidioides brasiliensis and identification of Aspergillus felis as a promising source of natural bioactive compounds.

    PubMed

    Mendes, Graziele; Gonçalves, Vívian N; Souza-Fagundes, Elaine M; Kohlhoff, Markus; Rosa, Carlos A; Zani, Carlos L; Cota, Betania B; Rosa, Luiz H; Johann, Susana

    2016-03-01

    Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values ≤ 125.0 µg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 µg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 µg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity. PMID:27008375

  8. Antifungal activity of extracts from Atacama Desert fungi against Paracoccidioides brasiliensis and identification of Aspergillus felis as a promising source of natural bioactive compounds.

    PubMed

    Mendes, Graziele; Gonçalves, Vívian N; Souza-Fagundes, Elaine M; Kohlhoff, Markus; Rosa, Carlos A; Zani, Carlos L; Cota, Betania B; Rosa, Luiz H; Johann, Susana

    2016-03-01

    Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values ≤ 125.0 µg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 µg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 µg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity.

  9. Evaluation of antifungal activity of free fatty acids methyl esters fraction isolated from Algerian Linum usitatissimum L. seeds against toxigenic Aspergillus

    PubMed Central

    Abdelillah, Amrouche; Houcine, Benmehdi; Halima, Dalile; Meriem, Chabane sari; Imane, Zaaboub; Eddine, Smahi Djamal; Abdallah, Moussaoui; Daoudi, Chabane sari

    2013-01-01

    Objective The aim of this study was to evaluate the antifungal activity of the major fraction of fatty acids methyl esters (FAMEs) isolated from Linum usitatissimum L. seeds oil collected from Bechar department (Algeria). Methods The assessment of antifungal activity was carried out in terms of percentage of radial growth on solid medium (potatoes dextrose agar PDA) and biomass growth inhibition on liquid medium (potatoes dextrose broth PDB) against two fungi. Results The FAMEs was found to be effective in inhibiting the radial mycelial growth of Aspergillus flavus more than Aspergillus ochraceus on all tested concentrations. The highest antifungal index was found to be (54.19%) compared to Aspergillus ochraceus (40.48%). The results of the antifungal activity of the FAMEs inhibition of biomass on liquid medium gave no discounted results, but this does not exclude the antifungal activity. Conclusions We can assume that the observed antifungal potency may be due to the abundance of linoleic and α-linolenic acids in linseed oil which appears to be promising to treat fungal infections, storage fungi and food spoilage in food industry field. PMID:23730556

  10. Total Antioxidant Capacity of Serum Determined Using the Potassium Permanganate Agar Method Based on Serum Diffusion in Agar

    PubMed Central

    Zhou, Ying; Zhang, Meijuan; Liu, Hui

    2015-01-01

    Objectives. To develop a new method for determining total antioxidants in serum and to evaluate the total antioxidant capacity of organisms. Design and Methods. Sodium hyposulfite (Na2S2O3) and serum were used to evaluate the linearity and precision of the potassium permanganate agar method. The area of serum diffusion in samples from 30 intensive care unit (ICU) patients compared with 44 healthy subjects was determined by the potassium permanganate agar method. Results. The linearity (R2 in the linear experiment of Na2S2O3 was 0.994; R2 in the linear experiment of serum was 0.987) and precision (coefficient of variation of area of high level serum diffusion within-run, between-run, and between-day and coefficient of variation of area of low serum diffusion within-run, between-run, and between-day were all less than 10%) were acceptable using the potassium permanganate agar method. Total antioxidants of serum between the ICU group and the healthy group were different (p = 0.002, two tailed). Conclusions. Total antioxidants in serum can be determined by the potassium permanganate agar method. The total antioxidant capacity of an organism can be evaluated by the amount of total antioxidants in serum. PMID:26347595

  11. Agar-agar entrapment increases the stability of endo-β-1,4-xylanase for repeated biodegradation of xylan.

    PubMed

    Bibi, Zainab; Shahid, Faiza; Ul Qader, Shah Ali; Aman, Afsheen

    2015-04-01

    Microbial xylanases, specially endo-β-1,4-xylanase catalyzes the hydrolysis of xylan, is considered one of the most significant hydrolases. It has numerous applications but most extensively is utilized in paper and pulp industry as a bio-bleaching agent. Immobilization technique is comprehensively studied with the expectation of modifying and improving enzyme stability and characteristics for commercial purposes. Currently, matrix entrapment technique is applied to immobilize endo-β-1,4-xylanase within agar-agar gel beads produced by Geobacillus stearothermophilus KIBGE-IB29. Maximal enzyme immobilization yield was achieved at 2.5% of agar-agar concentration. Optimized conditions demonstrated an increase in the optimal reaction time from 05 min to 30 min and incubation temperature from 50 °C to 60 °C with reference to free enzyme whereas; no effect was observed for optimum pH. Entrapment technique uniquely changed the kinetic parameters of immobilized endo-β-1,4-xylanase (Km: 0.5074 mg min(-1) to 0.5230 mg min(-1) and Vmax: 4773 U min(-1) to 968 U min(-1)) as compared to free enzyme. However, immobilized enzyme displayed broad thermal stability and retained 79.0% of its initial activity at 80 °C up to 30 min whereas; free enzyme completely lost its activity at this temperature. With respect to economic feasibility, the immobilized enzyme showed impressive recycling efficiency up to six reaction cycles. PMID:25603143

  12. Thermal-induced ageing of agar solutions: impact on the structural and mechanical properties of agar gels

    NASA Astrophysics Data System (ADS)

    Mao, Bosi; Bentaleb, Ahmed; Louerat, Frédéric; Divoux, Thibaut; Snabre, Patrick

    Numerous hydrogels are prepared by cooling down to ambient temperature, aqueous polymer solutions brought to a boil. Although the incubation time of the polymer solution at such a high temperature could be used as a tuning parameter, its impact on the subsequent gelation has been poorly investigated. Here we study the effect of prolonged heating at 80°C on a 1.5% wt solution of agar, a natural polysaccharide. The incubation time is varied from a few hours up to five days. We show that the agar sol. continuously degrades as the result of both the hydrolysis and the intermolecular oxidation of the polymer chains. Furthermore, electronic microscopy and X-ray diffraction experiments reveal that gels formed from older agar sols display an increasingly coarser microstructure composed of micron-sized aggregated pieces of polysaccharides, in contrast with the fibrous-like structure of gels made from fresh sols. Along with structural changes prolonged incubation time leads to weaker gels of lower shear elastic modulus. Finally, macro-indentation experiments coupled to direct visualization show that increasing the incubation time of the agar sol. decreases the yield strain of the gel by a factor of three, while the rupture scenario turns continuously from brittle to ductile-like. Acknowledging funding from BioMérieux & CNRS.

  13. 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.

  14. 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

  15. Endogenous nitric oxide accumulation is involved in the antifungal activity of Shikonin against Candida albicans

    PubMed Central

    Liao, Zebin; Yan, Yu; Dong, Huaihuai; Zhu, Zhenyu; Jiang, Yuanying; Cao, Yingying

    2016-01-01

    The aim of the present study was to investigate the role of nitric oxide (NO) in the antifungal activity of Shikonin (SK) against Candida albicans (C. albicans) and to clarify the underlying mechanism. The results showed that the NO donors S-nitrosoglutathione (GSNO) and L-arginine could enhance the antifungal activity of SK, whereas the NO production inhibitor Nω-nitro-L-arginine methyl ester (L-NAME) attenuated antifungal action. Using the fluorescent dye 3-amino,4-aminomethyl-2′, 7-difluorescein, diacetate (DAF-FM DA), we found that the accumulation of NO in C. albicans was increased markedly by SK in a time- and dose-dependent manner. In addition, the results of real-time reverse transcription-PCR (RT-PCR) demonstrated that the transcription level of YHB1 in C. albicans was greatly increased upon incubation of SK. Consistently, the YHB1-null mutant (yhb1Δ/Δ) exhibited a higher susceptibility to SK than wild-type cells. In addition, although the transcription level of CTA4 in C. albicans was not significantly changed when exposed to SK, the CTA4-null mutant (cta4Δ/Δ) was more susceptible to SK. Collectively, SK is the agent found to execute its antifungal activity directly via endogenous NO accumulation, and NO-mediated damage is related to the suppression of YHB1 and the function of CTA4. PMID:27530748

  16. Infected nail plate model made of human hair keratin for evaluating the efficacy of different topical antifungal formulations against Trichophyton rubrum in vitro.

    PubMed

    Lusiana; Reichl, Stephan; Müller-Goymann, Christel C

    2013-08-01

    A novel model of infected nail plate for testing the efficacy of topical antifungal formulations has been developed. This model utilized keratin film made of human hair keratin as a nail plate model. Subsequent to infection by Trichophyton rubrum, the common causative agent of onychomycosis, keratin films as infected nail plate models were treated with selected topical formulations, that is cream, gel, and nail lacquer. Bovine hoof was compared to keratin film. In contrast to the common antifungal susceptibility test, the antifungal drugs tested were applied as ready-to-use formulations because the vehicle may modify and control the drug action both in vitro and in vivo. Extrapolating the potency of an antifungal drug from an in vitro susceptibility test only would not be representative of the in vivo situation since these drugs are applied as ready-to-use formulations, for example as a nail lacquer. Although terbinafine has been acknowledged to be the most effective antifungal agent against T. rubrum, its antifungal efficacy was improved by its incorporation into an optimal formulation. Different gels proved superior to cream. Therefore, this study is able to discriminate between efficacies of different topical antifungal formulations based on their activities against T. rubrum. PMID:23419812

  17. Infected nail plate model made of human hair keratin for evaluating the efficacy of different topical antifungal formulations against Trichophyton rubrum in vitro.

    PubMed

    Lusiana; Reichl, Stephan; Müller-Goymann, Christel C

    2013-08-01

    A novel model of infected nail plate for testing the efficacy of topical antifungal formulations has been developed. This model utilized keratin film made of human hair keratin as a nail plate model. Subsequent to infection by Trichophyton rubrum, the common causative agent of onychomycosis, keratin films as infected nail plate models were treated with selected topical formulations, that is cream, gel, and nail lacquer. Bovine hoof was compared to keratin film. In contrast to the common antifungal susceptibility test, the antifungal drugs tested were applied as ready-to-use formulations because the vehicle may modify and control the drug action both in vitro and in vivo. Extrapolating the potency of an antifungal drug from an in vitro susceptibility test only would not be representative of the in vivo situation since these drugs are applied as ready-to-use formulations, for example as a nail lacquer. Although terbinafine has been acknowledged to be the most effective antifungal agent against T. rubrum, its antifungal efficacy was improved by its incorporation into an optimal formulation. Different gels proved superior to cream. Therefore, this study is able to discriminate between efficacies of different topical antifungal formulations based on their activities against T. rubrum.

  18. Antifungal activity of Curcuma longa grown in Thailand.

    PubMed

    Wuthi-udomlert, M; Grisanapan, W; Luanratana, O; Caichompoo, W

    2000-01-01

    Curcuma longa Linn. or turmeric (Zingiberaceae) is a medicinal plant widely used and cultivated in tropical regions. According to Thai traditional texts, fresh and dried rhizomes are used as peptic ulcer treatment, carminatives, wound treatment and anti-inflammatory agent. Using hydro distillation, 1.88% and 7.02% (v/w) volatile oils were extracted from fresh and dried rhizomes, respectively, and 6.95% (w/w)crude curcuminoids were extracted from dried rhizomes. Dried powder was extracted with 95% ethanol and yielded 29.52% (w/w) crude ethanol extract composed of curcumin (11.6%), demethoxycurcumin (10.32%) and bisdemethoxycurcumin (10.77%). These extracts were tested for antifungal activity by agar disc diffusion method against 29 clinical strains of dermatophytes. It was found that crude ethanol extract exhibited an inhibition zone range of 6.1 to 26.0 mm. There was no inhibition activity from crude curcuminoids while curcumin, demethoxycurcumin and bisdemethoxycutcumin gave different inhibition zone diameters ranging from 6.1 to 16.0 mm. Although antifungal activity of undiluted freshly distilled oil and 18-month-old oil revealed some differences, the inhibition zone diameters for both extracts varied within 26.1 to 46.0 mm. With 200 mg/ml ketoconazole, the activities of the standard agent were similar to the oil, both freshly distilled and 18-month-old, but were significantly different from those of curcuminoid compounds and crude ethanol extracts (p < 0.01). Turmeric oil was also tested for its minimum inhibitory concentration (MIC) by broth dilution method. The MICs of freshly distilled and 18-month-old oils were 7.8 and 7.2 mg/ml respectively. PMID:11414453

  19. Antifungal properties of silver nanoparticles against indoor mould growth.

    PubMed

    Ogar, Anna; Tylko, Grzegorz; Turnau, Katarzyna

    2015-07-15

    The presence of moulds in indoor environments causes serious diseases and acute or chronic toxicological syndromes. In order to inhibit or prevent the growth of microorganisms on building materials, the disruption of their vital processes or the reduction of reproduction is required. The development of novel techniques that impair the growth of microorganisms on building materials is usually based on silver nanoparticles (AgNPs). It makes them an alternative to other biocides. AgNPs have proven antibacterial activity and became promising in relation to fungi. The aim of the study was to assess growth and morphology of mycelia of typical indoor fungal species: Penicillium brevicompactum, Aspergillus fumigatus, Cladosporium cladosporoides, Chaetomium globosum and Stachybotrys chartarum as well as Mortierella alpina, cultured on agar media. The antifungal activity of AgNPs was also tested in relation to C. globosum and S. chartarum grown on the surface of gypsum drywall. It was found that the presence of AgNPs in concentrations of 30-200mg/l significantly decreased the growth of fungi. However, in the case of M. alpina, AgNPs stimulated its growth. Moreover, strong changes in moulds morphology and colour were observed after administration of AgNPs. Parameters of conidiophores/sporangiophores varied depending on mould region and changed significantly after treatment with AgNPs. The experiments have shown antifungal properties of AgNPs against common indoor mould species. Their application to building materials could effectively protect indoor environments from mould development. However, consideration must be given to the fact that the growth of some fungal strains might be stimulated by AgNPs.

  20. Antifungal Activity of C-27 Steroidal Saponins

    PubMed Central

    Yang, Chong-Ren; Zhang, Ying; Jacob, Melissa R.; Khan, Shabana I.; Zhang, Ying-Jun; Li, Xing-Cong

    2006-01-01

    As part of our search for new antifungal agents from natural resources, 22 C-27 steroidal saponins and 6 steroidal sapogenins isolated from several monocotyledonous plants were tested for their antifungal activity against the opportunistic pathogens Candida albicans, Candida glabrata, Candida krusei, Cryptococcus neoformans, and Aspergillus fumigatus. The results showed that the antifungal activity of the steroidal saponins was associated with their aglycone moieties and the number and structure of monosaccharide units in their sugar chains. Within the 10 active saponins, four tigogenin saponins (compounds 1 to 4) with a sugar moiety of four or five monosaccharide units exhibited significant activity against C. neoformans and A. fumigatus, comparable to the positive control amphotericin B. The antifungal potency of these compounds was not associated with cytotoxicity to mammalian cells. This suggests that the C-27 steroidal saponins may be considered potential antifungal leads for further preclinical study. PMID:16641439

  1. Natural and synthetic peptides with antifungal activity.

    PubMed

    Ciociola, Tecla; Giovati, Laura; Conti, Stefania; Magliani, Walter; Santinoli, Claudia; Polonelli, Luciano

    2016-08-01

    In recent years, the increase of invasive fungal infections and the emergence of antifungal resistance stressed the need for new antifungal drugs. Peptides have shown to be good candidates for the development of alternative antimicrobial agents through high-throughput screening, and subsequent optimization according to a rational approach. This review presents a brief overview on antifungal natural peptides of different sources (animals, plants, micro-organisms), peptide fragments derived by proteolytic cleavage of precursor physiological proteins (cryptides), synthetic unnatural peptides and peptide derivatives. Antifungal peptides are schematically reported based on their structure, antifungal spectrum and reported effects. Natural or synthetic peptides and their modified derivatives may represent the basis for new compounds active against fungal infections. PMID:27502155

  2. Comparison of Results Obtained by Testing with Three Different Agar Media and by the NCCLS M27-A Method for In Vitro Testing of Fluconazole against Candida spp.

    PubMed Central

    Rubio, M. Carmen; Gil, Joaquina; de Ocáriz, Inmaculada Ramírez; Benito, Rafael; Rezusta, Antonio

    2003-01-01

    Fluconazole susceptibilities of 150 Candida isolates were determined by a 25-μg fluconazole disk diffusion agar test and compared with the microdilution NCCLS M27-A method. The agar test used three different media and was read at 24 and 48 h. When only the susceptible and nonsusceptible categories were used, disk diffusion with Müeller-Hinton agar supplemented with 2% glucose and 0.5 μg of methylene blue (MHGM) per ml had a 95.37% correlation with the MIC method at 24 h, followed by RPMI 1640-2% of glucose agar (correlation, 94%) and Shadomy medium (SHDM) (correlation, 92.6%). The growth of microcolonies inside the inhibition zones was common (>63%) in the RPMI and SHDM media and minimal with MHGM (8.7%). At 48 h, MHGM and SHDM still had a >91% correlation with the MIC, while RPMI results had dropped to 75%. The best overall agreement was obtained with C. dubliniensis (100%). PMID:12791899

  3. In vitro susceptibilities of Mycoplasma genitalium to antibiotics.

    PubMed Central

    Renaudin, H; Tully, J G; Bebear, C

    1992-01-01

    The susceptibilities of seven clinical isolates of Mycoplasma genitalium and three strains of Mycoplasma pneumoniae to a variety of antibiotics were examined by an agar dilution method. Macrolides, pristinamycin, and tetracyclines were very active against both species. Sparfloxacin was the most active quinolone tested. None of the 21 antibiotics tested had differential activity toward the two organisms. PMID:1503451

  4. 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.

  5. Diversities in virulence, antifungal activity, pigmentation and DNA fingerprint among strains of Burkholderia glumae.

    PubMed

    Karki, Hari S; Shrestha, Bishnu K; Han, Jae Woo; Groth, Donald E; Barphagha, Inderjit K; Rush, Milton C; Melanson, Rebecca A; Kim, Beom Seok; Ham, Jong Hyun

    2012-01-01

    Burkholderia glumae is the primary causal agent of bacterial panicle blight of rice. In this study, 11 naturally avirulent and nine virulent strains of B. glumae native to the southern United States were characterized in terms of virulence in rice and onion, toxofalvin production, antifungal activity, pigmentation and genomic structure. Virulence of B. glumae strains on rice panicles was highly correlated to virulence on onion bulb scales, suggesting that onion bulb can be a convenient alternative host system to efficiently determine the virulence of B. glumae strains. Production of toxoflavin, the phytotoxin that functions as a major virulence factor, was closely associated with the virulence phenotypes of B. glumae strains in rice. Some strains of B. glumae showed various levels of antifungal activity against Rhizoctonia solani, the causal agent of sheath blight, and pigmentation phenotypes on casamino acid-peptone-glucose (CPG) agar plates regardless of their virulence traits. Purple and yellow-green pigments were partially purified from a pigmenting strain of B. glumae, 411gr-6, and the purple pigment fraction showed a strong antifungal activity against Collectotrichum orbiculare. Genetic variations were detected among the B. glumae strains from DNA fingerprinting analyses by repetitive element sequence-based PCR (rep-PCR) for BOX-A1R-based repetitive extragenic palindromic (BOX) or enterobacterial repetitive intergenic consensus (ERIC) sequences of bacteria; and close genetic relatedness among virulent but pigment-deficient strains were revealed by clustering analyses of DNA fingerprints from BOX-and ERIC-PCR.

  6. Identification and production of Azotobacter vinelandii and its antifungal activity against Fusarium oxysporum.

    PubMed

    Bhosale, H J; Kadam, T A; Bobade, A R

    2013-03-01

    The phytopathogenic Fusarium species are one of the leading causes of loss in agricultural productivity. In search of an efficient bacterial antagonist, 19 soil isolates of Azotobacter sp. were screened for antagonistic activity against Fusarium oxysporum by agar well diffusion assay. The potential strain was identified as Azotobacter vinelandii by 16S rRNA sequencing. Optimum conditions for culturing A. vinelandii to obtain maximum antifungal activity were determined by varying temperature, pH, incubation period and NaCl and sucrose concentration. Maximum inhibition of F. oxysporum was observed at pH 7 and 8, 1% NaCI and 2% sucrose concentration and after 72 hr of incubation at 30 degrees C temperature. A. vinelandii showed 44% higher yield of antifungal metabolite under optimized conditions. The minimum inhibitory concentration was 10 microg ml(-1) for F. oxysporum. The FTIR analysis of purified metabolite showed presence of aldehyde, C-N, ester, aromatic ring, P-H stretch, and C-N stretch of alkyl amine in the structure. The purified antifungal metabolite of A. vinelandii showed effect on spore germination and mycelia morphology of F. oxysporum. The study revealed significance of A. vinelandii in controlling F. oxysporum and its promising application as a biocontrol agent in agriculture.

  7. Antifungal activity, toxicity and chemical composition of the essential oil of Coriandrum sativum L. fruits.

    PubMed

    Soares, Bruna V; Morais, Selene M; dos Santos Fontenelle, Raquel Oliveira; Queiroz, Vanessa A; Vila-Nova, Nadja S; Pereira, Christiana M C; Brito, Edy S; Neto, Manoel A S; Brito, Erika H S; Cavalcante, Carolina S P; Castelo-Branco, Débora S C M; Rocha, Marcos F G

    2012-01-01

    The aims of this study were to test the antifungal activity, toxicity and chemical composition of essential oil from C. sativum L. fruits. The essential oil, obtained by hydro-distillation, was analyzed by gas chromatography/mass spectroscopy. Linalool was the main constituent (58.22%). The oil was considered bioactive, showing an LC₅₀ value of 23 μg/mL in the Artemia salina lethality test. The antifungal activity was evaluated against Microsporum canis and Candida spp. by the agar-well diffusion method and the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) were established by the broth microdilution method. The essential oil induced growth inhibition zones of 28 ± 5.42 and 9.25 ± 0.5 for M. canis and Candida spp. respectively. The MICs and MFCs for M. canis strains ranged from 78 to 620 and 150 to 1,250 μg/mL, and the MICs and MFCs for Candida spp strains ranged from 310 to 620 and 620 to 1,250 μg/mL, respectively. C. sativum essential oil is active in vitro against M. canis and Candida spp. demonstrating good antifungal activity.

  8. Active packaging with antifungal activities.

    PubMed

    Nguyen Van Long, N; Joly, Catherine; Dantigny, Philippe

    2016-03-01

    There have been many reviews concerned with antimicrobial food packaging, and with the use of antifungal compounds, but none provided an exhaustive picture of the applications of active packaging to control fungal spoilage. Very recently, many studies have been done in these fields, therefore it is timely to review this topic. This article examines the effects of essential oils, preservatives, natural products, chemical fungicides, nanoparticles coated to different films, and chitosan in vitro on the growth of moulds, but also in vivo on the mould free shelf-life of bread, cheese, and fresh fruits and vegetables. A short section is also dedicated to yeasts. All the applications are described from a microbiological point of view, and these were sorted depending on the name of the species. Methods and results obtained are discussed. Essential oils and preservatives were ranked by increased efficacy on mould growth. For all the tested molecules, Penicillium species were shown more sensitive than Aspergillus species. However, comparison between the results was difficult because it appeared that the efficiency of active packaging depended greatly on the environmental factors of food such as water activity, pH, temperature, NaCl concentration, the nature, the size, and the mode of application of the films, in addition to the fact that the amount of released antifungal compounds was not constant with time.

  9. Active packaging with antifungal activities.

    PubMed

    Nguyen Van Long, N; Joly, Catherine; Dantigny, Philippe

    2016-03-01

    There have been many reviews concerned with antimicrobial food packaging, and with the use of antifungal compounds, but none provided an exhaustive picture of the applications of active packaging to control fungal spoilage. Very recently, many studies have been done in these fields, therefore it is timely to review this topic. This article examines the effects of essential oils, preservatives, natural products, chemical fungicides, nanoparticles coated to different films, and chitosan in vitro on the growth of moulds, but also in vivo on the mould free shelf-life of bread, cheese, and fresh fruits and vegetables. A short section is also dedicated to yeasts. All the applications are described from a microbiological point of view, and these were sorted depending on the name of the species. Methods and results obtained are discussed. Essential oils and preservatives were ranked by increased efficacy on mould growth. For all the tested molecules, Penicillium species were shown more sensitive than Aspergillus species. However, comparison between the results was difficult because it appeared that the efficiency of active packaging depended greatly on the environmental factors of food such as water activity, pH, temperature, NaCl concentration, the nature, the size, and the mode of application of the films, in addition to the fact that the amount of released antifungal compounds was not constant with time. PMID:26803804

  10. Comparison of dosimetry gels prepared by agar and bovine gelatine

    NASA Astrophysics Data System (ADS)

    Sağsöz, M. E.; Korkut, Ö.; Alemdar, N.; Aktaş, S.; Çalı, E. B.; Kantarcı, M.

    2016-04-01

    Gel dosimeters are unique materials capable of showing three dimensional (3D) dose distributions of therapeutic or diagnostic exposures. Fricke gel dosimeters can be considered as chemical dosimeters that rely on a radiation-induced chemical reaction. Dose distribution of Fricke solutions containing Fe+2 ions determines the transformation of acidic, oxygen saturated Fe+2 ions to Fe+3 ions by the ionizing radiation in aqueous solutions. In this study we produced two different types of gel dosimeters using agar and bovine gelatin with similar fabrication methods. We compared the magnetic resonance (MR) T1 imaging responses of these two gel dosimeters to acquire a dose dependency of MR intensities. In conclusion agar gel dosimeters found to be produced easily and more consistent.

  11. A modified agar plate method for detection of Strongyloides stercoralis.

    PubMed

    Koga, K; Kasuya, S; Khamboonruang, C; Sukhavat, K; Ieda, M; Takatsuka, N; Kita, K; Ohtomo, H

    1991-10-01

    The agar plate method is a new technique with high detection rates for coprological diagnosis of human strongyloidiasis. This report details modifications of the technique and establishes a standardized procedure. We recommend that all plates should be carefully observed using a microscope because macroscopic observation can lead to false negative results. It is also advisable to pour formalin solution directly into microscopically positive dishes to collect worms by sedimentation. This procedure enables one to observe worms otherwise hidden. Sealing dishes with adhesive tape prevents larvae from crawling out of the dishes, eliminating any possibility in the reduction of detection rates, and greatly improves the safety conditions for the technician performing the procedure. We consider the agar plate method to be superior to the filter paper method in detecting Strongyloides, and we believe that it will eventually become the technique of choice. PMID:1951861

  12. Mupirocin-mucin agar for selective enumeration of Bifidobacterium bifidum.

    PubMed

    Pechar, Radko; Rada, Vojtech; Parafati, Lucia; Musilova, Sarka; Bunesova, Vera; Vlkova, Eva; Killer, Jiri; Mrazek, Jakub; Kmet, Vladimir; Svejstil, Roman

    2014-11-17

    Bifidobacterium bifidum is a bacterial species exclusively found in the human intestinal tract. This species is becoming increasingly popular as a probiotic organism added to lyophilized products. In this study, porcine mucin was used as the sole carbon source for the selective enumeration of B. bifidum in probiotic food additives. Thirty-six bifidobacterial strains were cultivated in broth with mucin. Only 13 strains of B. bifidum utilized the mucin to produce acids. B. bifidum was selectively enumerated in eight probiotic food supplements using agar (MM agar) containing mupirocin (100 mg/L) and mucin (20 g/L) as the sole carbon source. MM agar was fully selective if the B. bifidum species was presented together with Bifidobacterium animalis subsp. lactis, Bifidobacterium breve, and Bifidobacterium longum subsp. longum species and with lactic acid bacteria (lactobacilli, streptococci). Isolated strains of B. bifidum were identified using biochemical, PCR, MALDI-TOF procedures and 16S rRNA gene sequencing. The novel selective medium was also suitable for the isolation of B. bifidum strains from human fecal samples.

  13. Modeling development of inhibition zones in an agar diffusion bioassay

    PubMed Central

    Chandrasekar, Vaishnavi; Knabel, Stephen J; Anantheswaran, Ramaswamy C

    2015-01-01

    A two-temperature agar diffusion bioassay is commonly used to quantify the concentration of nisin using Micrococcus luteus as the indicator microorganism. A finite element computational model based on Fick's second law of diffusion was used to predict the radius of the inhibition zone in this diffusion bioassay. The model developed was used to calculate nisin concentration profiles as a function of time and position within the agar. The minimum inhibitory concentration (MIC) of nisin against M. luteus was determined experimentally. The critical time (Tc) for growth of M. luteus within the agar diffusion bioassay was experimentally determined using incubation studies with nisin. The radius of the inhibition zone was predicted from the computational model as the location where the predicted nisin concentration at Tc was equal to MIC. The MIC was experimentally determined to be 0.156 μg mL−1, and Tc was determined to be 7 h. Good agreement (R2 = 0.984) was obtained between model-predicted and experimentally determined inhibition zone radii. PMID:26405525

  14. Mupirocin-mucin agar for selective enumeration of Bifidobacterium bifidum.

    PubMed

    Pechar, Radko; Rada, Vojtech; Parafati, Lucia; Musilova, Sarka; Bunesova, Vera; Vlkova, Eva; Killer, Jiri; Mrazek, Jakub; Kmet, Vladimir; Svejstil, Roman

    2014-11-17

    Bifidobacterium bifidum is a bacterial species exclusively found in the human intestinal tract. This species is becoming increasingly popular as a probiotic organism added to lyophilized products. In this study, porcine mucin was used as the sole carbon source for the selective enumeration of B. bifidum in probiotic food additives. Thirty-six bifidobacterial strains were cultivated in broth with mucin. Only 13 strains of B. bifidum utilized the mucin to produce acids. B. bifidum was selectively enumerated in eight probiotic food supplements using agar (MM agar) containing mupirocin (100 mg/L) and mucin (20 g/L) as the sole carbon source. MM agar was fully selective if the B. bifidum species was presented together with Bifidobacterium animalis subsp. lactis, Bifidobacterium breve, and Bifidobacterium longum subsp. longum species and with lactic acid bacteria (lactobacilli, streptococci). Isolated strains of B. bifidum were identified using biochemical, PCR, MALDI-TOF procedures and 16S rRNA gene sequencing. The novel selective medium was also suitable for the isolation of B. bifidum strains from human fecal samples. PMID:25217723

  15. Modeling development of inhibition zones in an agar diffusion bioassay.

    PubMed

    Chandrasekar, Vaishnavi; Knabel, Stephen J; Anantheswaran, Ramaswamy C

    2015-09-01

    A two-temperature agar diffusion bioassay is commonly used to quantify the concentration of nisin using Micrococcus luteus as the indicator microorganism. A finite element computational model based on Fick's second law of diffusion was used to predict the radius of the inhibition zone in this diffusion bioassay. The model developed was used to calculate nisin concentration profiles as a function of time and position within the agar. The minimum inhibitory concentration (MIC) of nisin against M. luteus was determined experimentally. The critical time (T c) for growth of M. luteus within the agar diffusion bioassay was experimentally determined using incubation studies with nisin. The radius of the inhibition zone was predicted from the computational model as the location where the predicted nisin concentration at T c was equal to MIC. The MIC was experimentally determined to be 0.156 μg mL(-1), and T c was determined to be 7 h. Good agreement (R (2) = 0.984) was obtained between model-predicted and experimentally determined inhibition zone radii.

  16. Antibacterial and Antifungal Activity of Biopolymers Modified with Ionic Liquid and Laponite.

    PubMed

    Sharma, Anshu; Prakash, Prem; Rawat, Kamla; Solanki, Pratima R; Bohidar, H B

    2015-09-01

    In the present study, the antimicrobial properties of modified biopolymers such as gelatin and agar have been investigated. These biopolymers (agar and gelatin) are modified by dissolving in ionic liquid (IL) [1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]) and 1-octyl-3-methyl imidazolium chloride ([C8mim][Cl])] solutions. It was noticed that agar-ionogel (Ag-IL), gelatin-ionogel (GB-IL), and gelatin organogel (gelatin-glycerol solution along with laponite, nanoclay) nanocomposite (GA-NC) formed are highly stable, optically clear, and transparent without any air bubbles. The antimicrobial activity of these (Ag-IL), (GB-IL), and GA-NC were analyzed for both gram-negative (Escherichia coli, Klebsiella pneumoniae) and gram-positive bacterial strains (Staphylococcus aureus and Staphylococcus pyogenes) and fungus A. niger, C. albicans. Antibacterial and antifungal activity studies were carried out at different dilutions such as 100, 99, and 90 % (v/v). It was found that Ag-IL, GB-IL, and individual IL ([C8mim][Cl]) exhibited superior antimicrobial activities, indicating that longer IL chain enhance the cell membrane permeability of S. aureus, S. pyogenes, and E. coli cells. However, GA-NC nanocomposite and [C2mim][Cl]-based composites does not exhibit any bacterial inhibition activity for all bacterial strains. PMID:26142901

  17. Antibacterial and Antifungal Activity of Biopolymers Modified with Ionic Liquid and Laponite.

    PubMed

    Sharma, Anshu; Prakash, Prem; Rawat, Kamla; Solanki, Pratima R; Bohidar, H B

    2015-09-01

    In the present study, the antimicrobial properties of modified biopolymers such as gelatin and agar have been investigated. These biopolymers (agar and gelatin) are modified by dissolving in ionic liquid (IL) [1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]) and 1-octyl-3-methyl imidazolium chloride ([C8mim][Cl])] solutions. It was noticed that agar-ionogel (Ag-IL), gelatin-ionogel (GB-IL), and gelatin organogel (gelatin-glycerol solution along with laponite, nanoclay) nanocomposite (GA-NC) formed are highly stable, optically clear, and transparent without any air bubbles. The antimicrobial activity of these (Ag-IL), (GB-IL), and GA-NC were analyzed for both gram-negative (Escherichia coli, Klebsiella pneumoniae) and gram-positive bacterial strains (Staphylococcus aureus and Staphylococcus pyogenes) and fungus A. niger, C. albicans. Antibacterial and antifungal activity studies were carried out at different dilutions such as 100, 99, and 90 % (v/v). It was found that Ag-IL, GB-IL, and individual IL ([C8mim][Cl]) exhibited superior antimicrobial activities, indicating that longer IL chain enhance the cell membrane permeability of S. aureus, S. pyogenes, and E. coli cells. However, GA-NC nanocomposite and [C2mim][Cl]-based composites does not exhibit any bacterial inhibition activity for all bacterial strains.

  18. The antifungal action of dandruff shampoos.

    PubMed

    Bulmer, A C; Bulmer, G S

    1999-01-01

    The disease commonly known as "dandruff" is caused by numerous host factors in conjunction with the normal flora yeast Malassezia furfur (Pityrosporum ovale). Indeed, clinical studies have shown that administration of antifungal agents correlates with an improved clinical condition. Almost all commercially available hair shampoos publicize that they contain some form of antifungal agent(s). However, few studies have been published in which antifungal activity of commercially available hair shampoos have been contrasted experimentally. In this study six commercially available shampoos (in the Philippines) were assessed for antifungal activity against a human (dandruff) isolate of M. furfur: (a) Head & Shoulders (Proctor & Gamble); (b) Gard Violet (Colgate-Palmolive); (c) Nizoral 1% (Janssen); (d) Nizoral 2% (Janssen); (e) Pantene Blue (Proctor & Gamble); and (f) Selsun Blue (Abbott). The results demonstrated that all six of the assayed hair shampoos have some antifungal effect on the test yeast. However, there was consider variation in potency of antifungal activity. Nizoral 1% and Nizoral 2% shampoo preparations were the most effective. The 1% Nizoral shampoo was consistently 10X better at killing yeast cells than the next closest rival shampoo. The 2% Nizoral shampoo was 10X better than the Nizoral 1% product and 100 times better than any of the other products assayed. The study demonstrated that shampoos containing a proven antifungal compound were the most effective in controlling the causative yeast.

  19. Antifungal activity of topical microemulsion containing a thiophene derivative.

    PubMed

    Guimarães, Geovani Pereira; de Freitas Araújo Reis, Mysrayn Yargo; da Silva, Dayanne Tomaz Casimiro; Junior, Francisco Jaime Bezerra Mendonça; Converti, Attílio; Pessoa, Adalberto; de Lima Damasceno, Bolívar Ponciano Goulart; da Silva, José Alexsandro

    2014-01-01

    Fungal infections have become a major problem of worldwide concern. Yeasts belonging to the Candida genus and the pathogenic fungus Cryptococcus neoformans are responsible for different clinical manifestations, especially in immunocompromised patients. Antifungal therapies are currently based on a few chemotherapeutic agents that have problems related to effectiveness and resistance profiles. Microemulsions are isotropic, thermodynamically stable transparent systems of oil, water and surfactant that can improve the solubilization of lipophilic drugs. Taking into account the need for more effective and less toxic drugs along with the potential of thiophene derivatives as inhibitors of pathogenic fungi growth, this study aimed to evaluate the antifungal activity of a thiophene derivative (5CN05) embedded in a microemulsion (ME). The minimum inhibitory concentration (MIC) was determined using the microdilution method using amphotericin B as a control. The formulations tested (ME- blank and ME-5CN05) showed physico-chemical properties that would allow their use by the topical route. 5CN05 as such exhibited moderate or weak antifungal activity against Candida species (MIC = 270-540 μg . mL(-1)) and good activity against C. neoformans (MIC = 17 μg . mL(-1)). Candida species were susceptible to ME-5CN05 (70-140 μg . mL(-1)), but C. neoformans was much more, presenting a MIC value of 2.2 μg . mL(-1). The results of this work proved promising for the pharmaceutical industry, because they suggest an alternative therapy against C. neoformans. PMID:25242940

  20. Essential oil composition, phytotoxic and antifungal activities of Ruta chalepensis L. leaves from High Atlas Mountains (Morocco).

    PubMed

    Bouajaj, Sana; Romane, Abderrahmane; Benyamna, Abdennaji; Amri, Ismail; Hanana, Mohsen; Hamrouni, Lamia; Romdhane, Mehrez

    2014-01-01

    This study aimed at the determination of chemical composition of essential oil obtained by hydrodistillation, and to evaluate their phytotoxic and antifungal activities. Leaves of Ruta chalepensis L. were collected from the region of Tensift Al Haouz (High Atlas Mountains) Marrakech, Morocco. The essential oil (oil yield is 0.56%) was analysed by GC-FID and GC/MS. Twenty-two compounds were identified and accounted for 92.4% of the total oil composition. The major components were undecan-2-one (49.08%), nonan-2-one (33.15%), limonene (4.19%) and decanone (2.71%). Antifungal ability of essential oils was tested by disc agar diffusion against five plant pathogenic fungi: Fusarium proliferatum, Fusarium pseudograminearum, Fusarium culmorum, Fusarium graminearum and Fusarium polyphialidicum. The oils were also tested in vitro for herbicidal activity by determining their influence on the germination and the shoot and root growth of two weed species, Triticum durum and Phalaris canariensis L.

  1. Synthesis of organometallic-based biologically active compounds: In vitro antibacterial, antifungal and cytotoxic properties of some sulfonamide incorporated ferrocences.

    PubMed

    Chohan, Zahid H

    2009-02-01

    Sulfonamides incorporated ferrocene (SIF) have been synthesized by the condensation reaction of sulfonamides (sulfanilamide, sulfathiazole or sulfamethaxazole) with 1,1'-diacetylferrocene. The synthesized compounds (SIF(1)-SIF(4)) have been characterized by their physical, spectral and analytical properties and have been screened for their in vitro antibacterial properties against pathogenic bacterial strains e.g., Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis Staphylococcus aureus and Salmonella typhi and for antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata using Agar-well diffusion method. Most of the compounds showed good antibacterial activity whereas, all the compounds exhibited significant antifungal activity. Brine shrimp bioassay was also carried out for in vitro cytotoxic properties against Artemia salina. PMID:18608785

  2. [Titration of Ebola and Marburg viruses by plaque formation under semi liquid agar].

    PubMed

    Ustinova, E N; Shestopalov, A M; Bakulina, L F; Chepurnov, A A

    2003-01-01

    The method of titration of Ebola and Marburg viruses using plaque formation under semifluid agar cover is considered. Advantages of this method over conventional method of titration of these viruses with the use of hard agar cover are discussed.

  3. Evaluation of PCR-based screening for vancomycin-resistant enterococci compared with a chromogenic agar-based culture method.

    PubMed

    Seo, Ja Young; Kim, Pyung-Whan; Lee, Jang-Ho; Song, Jae-Hoon; Peck, Kyong-Ran; Chung, Doo-Ryeon; Kang, Cheol-In; Ki, Chang-Seok; Lee, Nam Yong

    2011-07-01

    Rapid detection of vancomycin-resistant enterococci (VRE) infection is very important for control and prevention of nosocomial spread of these bacteria. A multiplex PCR method for rapid screening of VRE has recently been developed. We performed a prospective study of VRE screening tests to compare the performance of PCR to that of a chromogenic agar-based culture method. From January to December 2009, a total of 8815 rectal swab specimens were tested simultaneously for VRE by VRE selective culture and by PCR. The specimens were inoculated onto ChromID VRE agar containing 8 µg vancomycin ml⁻¹ and examined after 24 and 48 h of incubation. Identification and antibiotic susceptibility tests were performed using the automated VITEK-2 system and a supplementary E-test and disk diffusion test. Detection of the vanA and vanB genes was performed with the Seeplex VRE detection kit. Specimens were inoculated in enterococcosel broth for 16-24 h before PCR for enrichment of VRE. VRE were isolated from 741 of the 8815 specimens by chromogenic agar-based culture (8.4 %). vanA and vanB genotypes were detected in 758 (8.6 %) and 3 (0.03 %) specimens, respectively, by multiplex PCR. Sensitivity, specificity, positive predictive value and negative predictive value of PCR for detection of VRE were 98.2 %, 99.6 %, 95.7 %, and 99.8 %. No VRE were isolated from vanB-positive specimens. The overall performance of PCR is comparable to that of a chromogenic agar-based culture method for screening of VRE, so PCR could be an alternative or supportive method for effective control of nosocomial VRE infection.

  4. Nest sanitation through defecation: antifungal properties of wood cockroach feces

    NASA Astrophysics Data System (ADS)

    Rosengaus, Rebeca B.; Mead, Kerry; Du Comb, William S.; Benson, Ryan W.; Godoy, Veronica G.

    2013-11-01

    The wood cockroach Cryptocercus punctulatus nests as family units inside decayed wood, a substrate known for its high microbial load. We tested the hypothesis that defecation within their nests, a common occurrence in this species, reduces the probability of fungal development. Conidia of the entomopathogenic fungus, Metarhizium anisopliae, were incubated with crushed feces and subsequently plated on potato dextrose agar. Relative to controls, the viability of fungal conidia was significantly reduced following incubation with feces and was negatively correlated with incubation time. Although the cockroach's hindgut contained abundant β-1,3-glucanase activity, its feces had no detectable enzymatic function. Hence, these enzymes are unlikely the source of the fungistasis. Instead, the antifungal compound(s) of the feces involved heat-sensitive factor(s) of potential microbial origin. When feces were boiled or when they were subjected to ultraviolet radiation and subsequently incubated with conidia, viability was "rescued" and germination rates were similar to those of controls. Filtration experiments indicate that the fungistatic activity of feces results from chemical interference. Because Cryptocercidae cockroaches have been considered appropriate models to make inferences about the factors fostering the evolution of termite sociality, we suggest that nesting in microbe-rich environments likely selected for the coupling of intranest defecation and feces fungistasis in the common ancestor of wood cockroaches and termites. This might in turn have served as a preadaptation that prevented mycosis as these phylogenetically related taxa diverged and evolved respectively into subsocial and eusocial organizations.

  5. Nest sanitation through defecation: antifungal properties of wood cockroach feces.

    PubMed

    Rosengaus, Rebeca B; Mead, Kerry; Du Comb, William S; Benson, Ryan W; Godoy, Veronica G

    2013-11-01

    The wood cockroach Cryptocercus punctulatus nests as family units inside decayed wood, a substrate known for its high microbial load. We tested the hypothesis that defecation within their nests, a common occurrence in this species, reduces the probability of fungal development. Conidia of the entomopathogenic fungus, Metarhizium anisopliae, were incubated with crushed feces and subsequently plated on potato dextrose agar. Relative to controls, the viability of fungal conidia was significantly reduced following incubation with feces and was negatively correlated with incubation time. Although the cockroach's hindgut contained abundant β-1,3-glucanase activity, its feces had no detectable enzymatic function. Hence, these enzymes are unlikely the source of the fungistasis. Instead, the antifungal compound(s) of the feces involved heat-sensitive factor(s) of potential microbial origin. When feces were boiled or when they were subjected to ultraviolet radiation and subsequently incubated with conidia, viability was "rescued" and germination rates were similar to those of controls. Filtration experiments indicate that the fungistatic activity of feces results from chemical interference. Because Cryptocercidae cockroaches have been considered appropriate models to make inferences about the factors fostering the evolution of termite sociality, we suggest that nesting in microbe-rich environments likely selected for the coupling of intranest defecation and feces fungistasis in the common ancestor of wood cockroaches and termites. This might in turn have served as a preadaptation that prevented mycosis as these phylogenetically related taxa diverged and evolved respectively into subsocial and eusocial organizations. PMID:24271031

  6. Calcium signaling mediates antifungal activity of triazole drugs in the Aspergilli.

    PubMed

    Liu, Fei-fei; Pu, Li; Zheng, Qing-qing; Zhang, Yuan-wei; Gao, Rong-sui; Xu, Xu-shi; Zhang, Shi-zhu; Lu, Ling

    2015-08-01

    Azoles are widely applied and largely effective as antifungals; however, the increasing prevalence of clinically resistant isolates has yet to be matched by approaches to improve the efficacy of antimicrobial therapy. In this study, using the model fungus Aspergillus nidulans and one of the most common human pathogen Aspergillus fumigatus as research materials, we present the evidence that calcium signaling is involved in the azole-antifungals-induced stress-response reactions. In normal media, antifungal-itraconazole (ITZ) is able to induce the [Ca(2+)]c increased sharply but the addition of calcium chelator-EGTA or BAPTA almost blocks the calcium influx responses, resulted in the dramatically decreasing of [Ca(2+)]c transient. Real-time PCR analysis verified that six-tested Ca(2+)-inducible genes-two calcium channels (cchA/midA), a calmodulin-dependent phosphatase-calcineurin (cnaA), a transcription factor-crzA, and two calcium transporters (pmrA/pmcA)-could be transiently up-regulated by adding ITZ, indicating these components are involved in the azole stress-response reaction. Defect of cnaA or crzA caused more susceptibility to azole antifungals than did single mutants or double deletions of midA and cchA. Notably, EGTA may influence Rh123 accumulation as an azole-mimicking substrate through the process of the drug absorption. In vivo studies of a Galleria mellonella model identified that the calcium chelator works as an adjunct antifungal agent with azoles for invasive aspergillosis. Most importantly, combination of ITZ and EGTA or ITZ with calcium signaling inhibitor-FK506 greatly enhances the ITZ efficacy. Thus, our study provides potential clues that specific inhibitors of calcium signaling could be clinically useful adjuncts to conventional azole antifungals in the Aspergilli.

  7. Antifungal proteins: More than antimicrobials?

    PubMed Central

    Hegedüs, Nikoletta; Marx, Florentine

    2013-01-01

    Antimicrobial proteins (AMPs) are widely distributed in nature. In higher eukaryotes, AMPs provide the host with an important defence mechanism against invading pathogens. AMPs of lower eukaryotes and prokaryotes may support successful competition for nutrients with other microorganisms of the same ecological niche. AMPs show a vast variety in structure, function, antimicrobial spectrum and mechanism of action. Most interestingly, there is growing evidence that AMPs also fulfil important biological functions other than antimicrobial activity. The present review focuses on the mechanistic function of small, cationic, cysteine-rich AMPs of mammals, insects, plants and fungi with antifungal activity and specifically aims at summarizing current knowledge concerning additional biological properties which opens novel aspects for their future use in medicine, agriculture and biotechnology. PMID:23412850

  8. Novel, Synergistic Antifungal Combinations that Target Translation Fidelity.

    PubMed

    Moreno-Martinez, Elena; Vallieres, Cindy; Holland, Sara L; Avery, Simon V

    2015-11-17

    There is an unmet need for new antifungal or fungicide treatments, as resistance to existing treatments grows. Combination treatments help to combat resistance. Here we develop a novel, effective target for combination antifungal therapy. Different aminoglycoside antibiotics combined with different sulphate-transport inhibitors produced strong, synergistic growth-inhibition of several fungi. Combinations decreased the respective MICs by ≥8-fold. Synergy was suppressed in yeast mutants resistant to effects of sulphate-mimetics (like chromate or molybdate) on sulphate transport. By different mechanisms, aminoglycosides and inhibition of sulphate transport cause errors in mRNA translation. The mistranslation rate was stimulated up to 10-fold when the agents were used in combination, consistent with this being the mode of synergistic action. A range of undesirable fungi were susceptible to synergistic inhibition by the combinations, including the human pathogens Candida albicans, C. glabrata and Cryptococcus neoformans, the food spoilage organism Zygosaccharomyces bailii and the phytopathogens Rhizoctonia solani and Zymoseptoria tritici. There was some specificity as certain fungi were unaffected. There was no synergy against bacterial or mammalian cells. The results indicate that translation fidelity is a promising new target for combinatorial treatment of undesirable fungi, the combinations requiring substantially decreased doses of active components compared to each agent alone.

  9. Antifungal and antioxidant activities of the phytomedicine pipsissewa, Chimaphila umbellata.

    PubMed

    Galván, Imelda J; Mir-Rashed, Nadereh; Jessulat, Matthew; Atanya, Monica; Golshani, Ashkan; Durst, Tony; Petit, Philippe; Amiguet, Virginie Treyvaud; Boekhout, Teun; Summerbell, Richard; Cruz, Isabel; Arnason, John T; Smith, Myron L

    2008-02-01

    Bioassay-guided fractionation of Chimaphila umbellata (L.) W. Bart (Pyrolaceae) ethanol extracts led to the identification of 2,7-dimethyl-1,4-naphthoquinone (chimaphilin) as the principal antifungal component. The structure of chimaphilin was confirmed by 1H and 13C NMR spectroscopy. The antifungal activity of chimaphilin was evaluated using the microdilution method with Saccharomyces cerevisiae (0.05mg/mL) and the dandruff-associated fungi Malassezia globosa (0.39mg/mL) and Malassezia restricta (0.55mg/mL). Pronounced antioxidant activity of C. umbellata crude extract was also identified using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, suggesting this phytomedicine has an antioxidant function in wound healing. A chemical-genetic profile was completed with chimaphilin using approximately 4700 S. cerevisiae gene deletion mutants. Cellular roles of deleted genes in the most susceptible mutants and secondary assays indicate that the targets for chimaphilin include pathways involved in cell wall biogenesis and transcription. PMID:17950387

  10. Differential recovery of Streptococcus mutans from various mitis-salivarius agar preparations.

    PubMed Central

    Liljemark, W F; Okrent, D H; Bloomquist, C G

    1976-01-01

    Recoveries of Streptococcus mutans from human dental plaque were lower when plated on mitis-salivarius agar obtained from Baltimore Biological Laboratories as compared with mitis-salivarius agar obtained from Difco Laboratories. However, no difference in recoveries of established laboratory strains of S. mutans was observed between these two agar preparations. PMID:956358

  11. Agar underlay method for recovery of sublethally heat-injured bacteria.

    PubMed

    Kang, D H; Siragusa, G R

    1999-12-01

    A method of recovering sublethally heat-injured bacteria was developed. The procedure (termed the agar underlay method) uses a nonselective agar underlaid with a selective medium. In a two-chambered petri dish, the Lutri plate (LP), a nonselective agar is inoculated with a population of sublethally heat-injured bacteria. After a 2-h repair incubation period, selective agar is added to the bottom chamber of the LP and incubated. By diffusing through the nonselective top agar, selective agents from the underlay medium impart selectivity to the system. By the agar underlay method, recovery rates of the heat-injured food-borne pathogens Escherichia coli O157:H7 and Salmonella typhimurium were not different (P > 0. 05) from recovery rates determined with nonselective media. Sublethally heat-injured cells (60 degrees C for 1.5 min in buffer or 80 degrees C for 30 s on meat surfaces) grew and produced a typical colony morphology and color reaction when the agar underlay procedure was used with the appropriate respective selective agars. Unlike agar overlay methods for injury repair, the agar underlay procedure allows the typical selective-medium colony morphology to develop and allows colonies to be more easily picked for further characterization. Higher recovery rates of heat-injured fecal enterococci from bovine fecal samples and total coliforms from animal waste lagoons were obtained by the agar underlay method with selective agars than by direct plating on the respective selective media. PMID:10583985

  12. Electrospinning of agar/PVA aqueous solutions and its relation with rheological properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this work, we report the successful fabrication of agar-based nanofibers by an electrospinning technique using water as the solvent media. A tubeless spinneret was attached inside the electrospinning chamber, operated at 50 deg C, to avoid agar gelation. Pure agar solution 1% (w/w) showed inadequ...

  13. Replica plating of colonies from Listeria-selective agars to blood agar to improve the isolation of Listeria monocytogenes from foods.

    PubMed

    Cassiday, P K; Graves, L M; Swaminathan, B

    1990-07-01

    Bacterial colonies from Listeria-selective agars were replica plated to sheep blood agar to screen for beta-hemolysis. By using the replica plating method to test for the beta-hemolytic characteristic of all the colonies growing on Listeria-selective agars instead of picking 3 to 10 suspected colonies for further testing, we recovered Listeria monocytogenes from 59 of 142 Listeria-selective agar plates which contained colonies of hemolytic and nonhemolytic Listeria species and were negative when tested by conventional colony picks.

  14. Topical antifungals for seborrhoeic dermatitis

    PubMed Central

    Okokon, Enembe O; Verbeek, Jos H; Ruotsalainen, Jani H; Ojo, Olumuyiwa A; Bakhoya, Victor Nyange

    2015-01-01

    Background Seborrhoeic dermatitis is a chronic inflammatory skin condition that is distributed worldwide. It commonly affects the scalp, face and flexures of the body. Treatment options include antifungal drugs, steroids, calcineurin inhibitors, keratolytic agents and phototherapy. Objectives To assess the effects of antifungal agents for seborrhoeic dermatitis of the face and scalp in adolescents and adults. A secondary objective is to assess whether the same interventions are effective in the management of seborrhoeic dermatitis in patients with HIV/AIDS. Search methods We searched the following databases up to December 2014: the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 11), MEDLINE (from 1946), EMBASE (from 1974) and Latin American Caribbean Health Sciences Literature (LILACS) (from 1982). We also searched trials registries and checked the bibliographies of published studies for further trials. Selection criteria Randomised controlled trials of topical antifungals used for treatment of seborrhoeic dermatitis in adolescents and adults, with primary outcome measures of complete clearance of symptoms and improved quality of life. Data collection and analysis Review author pairs independently assessed eligibility for inclusion, extracted study data and assessed risk of bias of included studies. We performed fixed-effect meta-analysis for studies with low statistical heterogeneity and used a random-effects model when heterogeneity was high. Main results We included 51 studies with 9052 participants. Of these, 45 trials assessed treatment outcomes at five weeks or less after commencement of treatment, and six trials assessed outcomes over a longer time frame. We believe that 24 trials had some form of conflict of interest, such as funding by pharmaceutical companies. Among the included studies were 12 ketoconazole trials (N = 3253), 11 ciclopirox trials (N = 3029), two lithium trials (N = 141

  15. 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. PMID:24618110

  16. Antifungal effect of some spice hydrosols.

    PubMed

    Boyraz, Nuh; Ozcan, Musa

    2005-12-01

    The antifungal effects of rosemary, cumin, sater (savory), basil and pickling herb hydrosols were investigated against Rhizoctonia solani, Fusarium oxysporum f. sp tulipae, Botrytis cinerea and Alternaria citri. Hydrosols of sater and pickling herb showed the most relevant fungicidal activity.

  17. Microbial susceptibility to calcium hydroxide pastes and their vehicles.

    PubMed

    Gomes, Brenda Paula Figueiredo de Almeida; Ferraz, Caio Cezar Randi; Garrido, Fabio Devora; Rosalen, Pedro Luiz; Zaia, Alexandre Augusto; Teixeira, Fabricio Batista; de Souza-Filho, Francisco José

    2002-11-01

    The aim of this study was to investigate the susceptibility of some microorganisms commonly isolated from root canals to calcium hydroxide in combination with several vehicles by the agar diffusion method. Stainless-steel cylinders were placed on each inoculated agar medium. The test medications and their controls were placed inside the cylinders. The zones of growth inhibition were measured and recorded after the incubation period for each plate, and the results were analyzed statistically. Enterococcus faecalis was most resistant, whereas the anaerobic Porphyromonas endodontalis was more susceptible to all medications, followed by P. gingivalis and Prevotella intermedial intermedia. Ca(OH)2 + CMCP + glycerin showed significantly larger mean zones of inhibition when compared with the other medications. We conclude that anaerobic Gram-negative bacteria are more susceptible to calcium hydroxide pastes than facultative Gram-positive microorganisms. PMID:12470019

  18. Antifungal activities of some indole derivatives.

    PubMed

    Xu, Hui; Wang, Qin; Yang, Wen-Bin

    2010-01-01

    Nine indole derivatives were evaluated in vitro against Fusarium graminearum, Alternaria alternata, Helminthosporium sorokinianum, Pyricularia oryzae, Fusarium oxysporum f. sp. vasinfectum, Fusarium oxysporum f. sp. cucumarinum, and Alternaria brassicae. Most of the compounds were found to possess antifungal activities. Especially compounds 2, 5, 8, and 9 exhibited broad-spectrum antifungal activities against the above-mentioned seven phytopathogenic fungi, and showed more potent activities than hymexazole, a commercial agricultural fungicide. PMID:20737910

  19. Agar-Gel Precipitin Technique in Anthrax Antibody Determinations1

    PubMed Central

    Ray, John G.; Kadull, Paul J.

    1964-01-01

    A modification of the agar-gel precipitation inhibition technique of Thorne and Belton for detecting anthrax antibodies reduces inconsistency of visually determined end points on the same sera observed by different technicians. Determination of the minimal reacting concentrations of the anthrax antigen and antibody reagents, modifications of the visualization apparatus, methods for combining reagents, and length of incubation periods contribute to the ease of the end-point determinations and the uniformity of results. When compared with the previous technique, the modified procedure is less time-consuming while retaining satisfactory reproducibility, simplicity, specificity, and sensitivity. Images FIG. 1 FIG. 2 PMID:14201088

  20. Culture of Piscirickettsia salmonis on enriched blood agar.

    PubMed

    Mauel, Michael J; Ware, Cynthia; Smith, Pedro A

    2008-03-01

    Piscirickettsia salmonis is the etiologic agent of piscirickettsiosis, an economically significant disease of fish. Isolation of P. salmonis by culturing on fish cell lines has been the standard technique since the initial isolation of the organism. The ability to grow P. salmonis on artificial media would relieve facilities of the cost of maintaining cell lines, permit isolation at fish culture sites with fewer contamination problems, and allow easier transport of isolates to diagnostic facilities for confirmation assays. This report describes the successful culture of P. salmonis on enriched blood agar. PMID:18319435

  1. Population-based survey of filamentous fungi and antifungal resistance in Spain (FILPOP Study).

    PubMed

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

    2013-07-01

    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 0.016/1,000 inhabitants [corrected]. 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

  2. Breakthrough candidaemia in the era of broad-spectrum antifungal therapies.

    PubMed

    Cuervo, G; Garcia-Vidal, C; Nucci, M; Puchades, F; Fernández-Ruiz, M; Obed, M; Manzur, A; Gudiol, C; Pemán, J; Aguado, J M; Ayats, J; Carratalà, J

    2016-02-01

    We aimed to assess the characteristics, treatment, risk factors and outcome of patients with breakthrough candidaemia (BrC) in the era of broad-spectrum antifungal therapies. We carried out a multicentre study of hospitalized adults with candidaemia at six hospitals in three countries. BrC episodes were compared with the remaining episodes (non-BrC). Of 409 episodes of candidaemia, 37 (9%) were BrC. Among them, antifungal treatment was administered as prophylaxis in 26 severely immunosuppressed patients (70%) and as a fever-driven approach in 11 (30%). Candida albicans was significantly less common in patients with BrC (24% versus 46%, p 0.010) whereas Candida krusei was more frequent (16% versus 2.4%, p < 0.001). BrC was associated with infections caused by fluconazole non-susceptible isolates (50% versus 18%, p < 0.001). Candida albicans BrC was associated with previous fluconazole treatment whereas Candida parapsilosis candidaemia was mostly catheter-related and/or associated with previous echinocandin therapy. The empirical antifungal therapy was more often appropriate in the non-BrC group (57% versus 74%, p 0.055). No significant differences were found in outcomes (early and overall mortality: 11% versus 13% p 0.802 and 40% versus 40% p 0.954, respectively). Fluconazole non-susceptibility was independently associated with the risk of BrC (adjusted OR 5.57; 95% CI 1.45-21.37). In conclusion, BrC accounted for 9% of the episodes in our multicentre cohort. The Candida spp. isolated were different depending on the previous antifungal therapy: previous azole treatment was associated with fluconazole non-susceptible strains and previous echinocandin treatment was associated with BrC caused by C. parapsilosis. These results should be taken into account to improve the empirical treatment of BrC.

  3. 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

  4. In vitro susceptibility of Capnocytophaga strains to 18 antimicrobial agents.

    PubMed Central

    Sutter, V L; Pyeatt, D; Kwok, Y Y

    1981-01-01

    Twenty-seven strains of capnocytophaga were tested for their susceptibility to 18 antimicrobial agents by an agar dilution technique. All strains were susceptible to achievable blood levels of penicillin G, cefaclor, cefoxitin, cefoperazone, moxalactam, clindamycin, chloramphenicol, and tetracycline. Most were susceptible to achievable levels of cefamandole, erythromycin, and metronidazole, and more than 10% were resistant to achievable levels of cephalexin and cephradine. With antimicrobial agents used in selective media, all strains were resistant to colistin, kanamycin, and nalidixic acid at commonly recommended concentrations of bacitracin and vancomycin. PMID:7283424

  5. Melanin protects Paracoccidioides brasiliensis from the effects of antimicrobial photodynamic inhibition and antifungal drugs.

    PubMed

    Baltazar, Ludmila Matos; Werneck, Silvia Maria Cordeiro; Soares, Betânia Maria; Ferreira, Marcus Vinicius L; Souza, Danielle G; Pinotti, Marcos; Santos, Daniel Assis; Cisalpino, Patrícia Silva

    2015-07-01

    Paracoccidioidomycosis (PCM) is a public health concern in Latin America and South America that when not correctly treated can lead to patient death. In this study, the influence of melanin produced by Paracoccidioides spp. on the effects of treatment with antimicrobial photodynamic inhibition (aPI) and antifungal drugs was evaluated. aPI was performed using toluidine blue (TBO) as a photosensitizer and a 630-nm light-emitting diode (LED) light. The antifungals tested were itraconazole and amphotericin B. We evaluated the effects of each approach, aPI or antifungals, against nonmelanized and melanized yeast cells by performing susceptibility tests and by quantifying oxidative and nitrosative bursts during the experiments. aPI reduced nonmelanized cells by 3.0 log units and melanized cells by 1.3 log units. The results showed that melanization protects the fungal cell, probably by acting as a scavenger of nitric oxide and reactive oxygen species, but not of peroxynitrite. Melanin also increased the MICs of itraconazole and amphotericin B, and the drugs were fungicidal for nonmelanized and fungistatic for melanized yeast cells. Our study shows that melanin production by Paracoccidioides yeast cells serves a protective function during aPI and treatment with itraconazole and amphotericin B. The results suggest that melanin binds to the drugs, changing their antifungal activities, and also acts as a scavenger of reactive oxygen species and nitric oxide, but not of peroxynitrite, indicating that peroxynitrite is the main radical that is responsible for fungal death after aPI.

  6. 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. PMID:24506041

  7. 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.

  8. Borelli's lactritmel agar induces conidiation in rare-macroconidia producing dermatophytic fungi.

    PubMed

    Ilkit, Macit; Gümral, Ramazan; Döğen, Aylin

    2012-10-01

    Macroconidia are among the most important indicators used to identify dermatophytic fungi, but several do not usually sporulate and/or produce macroconidia on Sabouraud glucose agar. Specifically, Microsporum audouinii, M. ferrugineum, Trichophyton concentricum, T. schoenleinii, T. verrucosum, and T. violaceum (including T. soudanense and T. yaoundei) rarely form macroconidia and, therefore, cannot be easily identified. In this study, we investigated the production of macroconidia on nine common laboratory media, including Borelli's lactritmel agar (BLA), modified Borelli's lactritmel agar (MBLA), brain heart infusion agar (BHIA), Christensen's urease agar in Petri dishes (UPA), cornmeal dextrose agar (CMDA), Lowenstein-Jensen agar (LJA), malt extract agar (MEA), oatmeal agar (OA), and potato dextrose agar (PDA). The performance of these media was evaluated using 18 rare-macroconidia producing isolates, including representative of the six species mentioned above. All cultures in this study were incubated at 26°C on the bench, and conidia formation on each was investigated at 5, 10, 15, 20, 25, and 30 days of incubation. BLA apparently improved macroconidia production after 15 days and was the most useful nutrient agar medium to induce these phenotypic characters in daily practice, closely followed by OA, PDA, and MBLA. PMID:22563856

  9. Physicochemical properties of biodegradable polyvinyl alcohol-agar films from the red algae Hydropuntia cornea.

    PubMed

    Madera-Santana, Tomás J; Robledo, Daniel; Freile-Pelegrín, Yolanda

    2011-08-01

    Agar obtained from the red alga Hydropuntia cornea was blended with polyvinyl alcohol (PVOH) in order to produce biodegradable films. In this study, we compare the properties of biopolymeric films formulated with agars extracted from H. cornea collected at different seasons (rainy and dry) in the Gulf of Mexico coast and PVOH as synthetic matrix. The films were prepared at different agar contents (0%, 25%, 50%, 75%, and 100%) and their optical, mechanical, thermal, and morphological properties analyzed. The tensile strength of PVOH-agar films increased when agar content was augmented. The formulation with 50% agar from rainy season (RS) had a significant higher tensile strength when compared to those from dry season (DS; p < 0.05). Tensile modulus also displayed an increasing trend and likewise, for 50% and 75% agar blends from RS showed higher values than those from DS (p < 0.05). In contrast, elongation at break decreased as the agar content increased, independently of the season. Environmental scanning electron microscopy images of PVOH-agar 75% biofilms from RS showed a homogeneous structure with good interfacial adhesion between the two components. The changes evidenced in the FTIR spectrum of this blend suggest that hydrogen bonding is taking place between the agar ether linkages (C-O-C) and the hydroxyl groups (OH) of the PVOH. Based on the above mentioned results, blends of PVOH and 75% agar from H. cornea collected in rainy season showed good properties for applications in the biodegradable packaging industry.

  10. [Clinical utility of Pourmedia GBS agar on screening for vaginal colonization of Group B Streptococcus].

    PubMed

    Kaneda, Mitsunori; Nagasaki, Hiromi; Tasaki, Megumi; Kamiyama, Kiyoshi

    2014-01-01

    Group B Streptococcus (GBS) are normal flora of the vagina and intestinal, but if the pregnant woman was infected with GBS in the vagina, miscarriage or premature would occur or the newborn would be developed to severe GBS infection. It is recommended that the inspection of GBS on all pregnant women by Japan Society of Obstetrics and Gynecology (JSOG) and Center for Disease Control and Prevention (CDC). We examined the comparison of detection rate between Pourmedia GBS agar (Eiken Chemical Co., Ltd.) and Nissui Separated Plate Sheep Blood Agar/BTB Lactose Agar medium (Nissui Pharmaceutical Co., Ltd.) on 112 sample. The positive rate of Pourmedia GBS agar was 21.4% (24/112 samples), Whereas Nissui Separated Plate Sheep Blood Agar/BTB Lactose Agar medium was 17.8% (20/112 samples). It was found that the detection rate was improved by using Pourmedia GBS agar on GBS screening test of vaginal swab.

  11. Agar Medium for Differential Enumeration of Lactic Streptococci1

    PubMed Central

    Reddy, M. S.; Vedamuthu, E. R.; Washam, C. J.; Reinbold, G. W.

    1972-01-01

    An agar medium containing arginine and calcium citrate as specific substrates, diffusible (K2HPO4) and undiffusible (CaCO3) buffer systems, and bromocresol purple as the pH indicator was developed to differentiate among lactic streptococci in pure and mixed cultures. Milk was added as the sole source of carbohydrate (lactose) and to provide growth-stimulating factors. Production of acid from lactose caused developing bacterial colonies to seem yellow. Subsequent arginine utilization by Streptococcus lactis and S. diacetilactis liberated ammonia, resulting in a localized pH shift back toward neutrality and a return of the original purple indicator hue. The effects of production of acid from lactose and ammonia were fixed around individual colonies by the buffering capacity of CaCO3. After 36 hr at 32 C in a candle oats jar, colonies of S. cremoris were yellow, whereas colonies of S. lactis and S. diacetilactis were white. S. diacetilactis, on further incubation, utilized suspended calcium citrate, and, after 6 days, the citrate-degrading colonies exhibited clear zoning against a turbid background, making them easily distinguishable from the colonies of the other two species. The medium proved suitable for quantitative differential enumeration when compared with another widely used general agar medium for lactic streptococci. Images PMID:16349952

  12. Assessment of Antifungal Activity of Bakuchiol on Oral-Associated Candida spp.

    PubMed Central

    Nordin, Mohd-Al-Faisal; Abdul Razak, Fathilah; Himratul-Aznita, Wan Harun

    2015-01-01

    Bakuchiol is an active component of Psoralea glandulosa and Psoralea corylifolia, used in traditional Chinese medicine. The study aimed at investigating the antifungal activity of bakuchiol on planktonic and biofilm forms of orally associated Candida species. The antifungal susceptibility testing was determined by the broth micro dilution technique. Growth kinetics and cell surface hydrophobicity (CSH) of Candida were measured to assess the inhibitory effect of bakuchiol on Candida planktonic cells. Biofilm biomass and cellular metabolic activity were quantitatively estimated by the crystal violet (CV) and the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) assays. All Candida strains have been shown to be susceptible to bakuchiol with the MIC ranges from 12.5 to 100 μg/mL. Significant decrease in specific growth rates and viable counts demonstrates the inhibitory effect of bakuchiol on Candida planktonic cells. A brief exposure to bakuchiol also reduced CSH of Candida (P < 0.05), indicating altered surface properties of yeast cells towards hydrophobic interfaces. Biofilm biomass and cell metabolic activity were mostly decreased, except for C. glabrata (P = 0.29). The antifungal properties of bakuchiol on Candida species in this in vitro study may give insights into the application in therapeutic strategy against Candida infections. PMID:26633986

  13. Antifungal Activity of 14-Helical β-Peptides against Planktonic Cells and Biofilms of Candida Species.

    PubMed

    Raman, Namrata; Lee, Myung-Ryul; Lynn, David M; Palecek, Sean P

    2015-01-01

    Candida albicans is the most prevalent cause of fungal infections and treatment is further complicated by the formation of drug resistant biofilms, often on the surfaces of implanted medical devices. In recent years, the incidence of fungal infections by other pathogenic Candida species such as C. glabrata, C. parapsilosis and C. tropicalis has increased. Amphiphilic, helical β-peptide structural mimetics of natural antimicrobial α-peptides have been shown to exhibit specific planktonic antifungal and anti-biofilm formation activity against C. albicans in vitro. Here, we demonstrate that β-peptides are also active against clinically isolated and drug resistant strains of C. albicans and against other opportunistic Candida spp. Different Candida species were susceptible to β-peptides to varying degrees, with C. tropicalis being the most and C. glabrata being the least susceptible. β-peptide hydrophobicity directly correlated with antifungal activity against all the Candida clinical strains and species tested. While β-peptides were largely ineffective at disrupting existing Candida biofilms, hydrophobic β-peptides were able to prevent the formation of C. albicans, C. glabrata, C. parapsilosis and C. tropicalis biofilms. The broad-spectrum antifungal activity of β-peptides against planktonic cells and in preventing biofilm formation suggests the promise of this class of molecules as therapeutics. PMID:26287212

  14. 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.

  15. Dermatophyte susceptibility varies towards antimicrobial textiles.

    PubMed

    Hammer, Timo R; Mucha, Helmut; Hoefer, Dirk

    2012-07-01

    Dermatophytoses are a widespread problem worldwide. Textiles in contact with infected skin can serve as a carrier for fungus propagation. Hitherto, it is unknown, whether antifungal textiles could contribute in controlling dermatophytes e.g. by disrupting the chain of infection. Testing of antimicrobial fabrics for their antifungal activities therefore is a fundamental prerequisite to assess the putative clinical relevance of textiles for dermatophyte prevention. Fabrics finished with either didecyldimethylammonium chloride (DDAC), poly-hexamethylenbiguanide, copper and two silver chloride concentrations were tested for their antifungal activity against Trichophyton rubrum, Trichophyton mentagrophytes and Candida albicans. To prove dermatophyte susceptibility towards the textiles, swatches were subjected to DIN EN 14199 (Trichophyton sp.) or DIN EN ISO 20743 (C. albicans) respectively. In addition, samples were embedded, and semi-thin sections were analysed microscopically. While all samples showed a clear inhibition of C. albicans, activity against Trichophyton sp. varied significantly: For example, DDAC completely inhibited T. rubrum growth, whereas T. mentagrophytes growth remained unaffected even in direct contact to the fibres. The results favour to add T. mentagrophytes as a test organism in textile dermatophyte efficacy tests. Microscopic analysis of swatches allowed detailed evaluation of additional parameters like mycelium thickness, density and hyphae penetration depth into the fabric.

  16. Comparison of Fecal Coliform Agar and Violet Red Bile Lactose Agar for Fecal Coliform Enumeration in Foods

    PubMed Central

    Leclercq, A.; Wanegue, C.; Baylac, P.

    2002-01-01

    A 24-h direct plating method for fecal coliform enumeration with a resuscitation step (preincubation for 2 h at 37 ± 1°C and transfer to 44 ± 1°C for 22 h) using fecal coliform agar (FCA) was compared with the 24-h standardized violet red bile lactose agar (VRBL) method. FCA and VRBL have equivalent specificities and sensitivities, except for lactose-positive non-fecal coliforms such as Hafnia alvei, which could form typical colonies on FCA and VRBL. Recovery of cold-stressed Escherichia coli in mashed potatoes on FCA was about 1 log unit lower than that with VRBL. When the FCA method was compared with standard VRBL for enumeration of fecal coliforms, based on counting carried out on 170 different food samples, results were not significantly different (P > 0.05). Based on 203 typical identified colonies selected as found on VRBL and FCA, the latter medium appears to allow the enumeration of more true fecal coliforms and has higher performance in certain ways (specificity, sensitivity, and negative and positive predictive values) than VRBL. Most colonies clearly identified on both media were E. coli and H. alvei, a non-fecal coliform. Therefore, the replacement of fecal coliform enumeration by E. coli enumeration to estimate food sanitary quality should be recommended. PMID:11916678

  17. Evaluation of eight agar media for the isolation of shiga toxin-Producing Escherichia coli.

    PubMed

    Gill, Alexander; Huszczynski, George; Gauthier, Martine; Blais, Burton

    2014-01-01

    The growth characteristics of 96 shiga toxin-producing Escherichia coli (STEC) strains representing 36 different O-types (including priority O types O26, O45, O103, O111, O121, O145 and O157) on commercial and in-house agar media were studied. The ability of the strains to grow on agar media with varying selective supplement formulations was evaluated using MacConkey Agar (MAC); Rainbow® Agar O157 (RBA); Rainbow® Agar O157 with manufacturer-recommended selective supplements (RBA-NT); Rainbow® Agar O157 with USDA-recommended selective supplements (RBA-USDA); CHROMagar STEC™ (CH STEC); Tryptone Bile agar containing cefixime and tellurite (TBA-CT); Tryptone Bile agar containing cefixime, tellurite, eosin and methylene blue (TBA-EM); and VTEC agar. All of the strains were able to grow on MAC, RBA and VTEC agar, whereas a number of strains (including some non-O157 priority O types) were unable to grow on the highly selective media CH STEC, RBA-NT, RBA-USDA, TBA-EM and TBA-CT. Only RBA-NT and CH STEC exhibited significant inhibition of background flora from ground beef enrichment. Significant inhibition of background flora from beef trim enrichment was observed with RBA-NT, RBA-USDA, CH STEC, TBA-EM and VTEC agar. With exception of E. coli O157, several different colony morphologies were observed on the differential plating media among strains of the same O type, indicating that this colony morphology is not a reliable means of identifying target STEC. These results suggest that an approach to maximize the recovery of target STEC from beef enrichment cultures is dual plating on lesser (RBA, MAC, VTEC agar) and more highly (RBA-NT, CH STEC) selective agars.

  18. ASDCD: antifungal synergistic drug combination database.

    PubMed

    Chen, Xing; Ren, Biao; Chen, Ming; Liu, Ming-Xi; Ren, Wei; Wang, Quan-Xin; Zhang, Li-Xin; Yan, Gui-Ying

    2014-01-01

    Finding effective drugs to treat fungal infections has important clinical significance based on high mortality rates, especially in an immunodeficient population. Traditional antifungal drugs with single targets have been reported to cause serious side effects and drug resistance. Nowadays, however, drug combinations, particularly with respect to synergistic interaction, have attracted the attention of researchers. In fact, synergistic drug combinations could simultaneously affect multiple subpopulations, targets, and diseases. Therefore, a strategy that employs synergistic antifungal drug combinations could eliminate the limitations noted above and offer the opportunity to explore this emerging bioactive chemical space. However, it is first necessary to build a powerful database in order to facilitate the analysis of drug combinations. To address this gap in our knowledge, we have built the first Antifungal Synergistic Drug Combination Database (ASDCD), including previously published synergistic antifungal drug combinations, chemical structures, targets, target-related signaling pathways, indications, and other pertinent data. Its current version includes 210 antifungal synergistic drug combinations and 1225 drug-target interactions, involving 105 individual drugs from more than 12,000 references. ASDCD is freely available at http://ASDCD.amss.ac.cn.

  19. Characterization of Leptospiral Chemoreceptors Using a Microscopic Agar Drop Assay.

    PubMed

    Affroze, Samia; Islam, Md Shafiqul; Takabe, Kyosuke; Kudo, Seishi; Nakamura, Shuichi

    2016-08-01

    Bacterial chemotaxis is induced by sensing chemical stimuli via chemoreceptors embedded in the cytoplasmic membrane, enabling the cells to migrate toward nutrients or away from toxins. The chemoreceptors of Escherichia coli and Salmonella spp. have been well studied and are functionally classified on the basis of detectable substrates. The spirochete Leptospira possesses more than ten chemoreceptors and shows attractive or repellent responses against some sugars, amino acids, and fatty acids. However, the roles of these chemoreceptors have not been investigated. In this study, we conducted a chemotaxis assay called microscopic agar drop assay in combination with competition experiments, determining whether two kinds of attractants are recognized by the same type of chemoreceptor in the saprophytic Leptospira strain, Leptospira biflexa. Analyzing the competition effect observed between several pairs of chemicals, we found that L. biflexa senses sugars via chemoreceptors different from those that sense amino acids and fatty acids.

  20. Synthesis and biological evaluation of fluconazole analogs with triazole-modified scaffold as potent antifungal agents.

    PubMed

    Hashemi, Seyedeh Mahdieh; Badali, Hamid; Irannejad, Hamid; Shokrzadeh, Mohammad; Emami, Saeed

    2015-04-01

    In order to find new azole antifungals, we have recently designed a series of triazole alcohols in which one of the 1,2,4-triazol-1-yl group in fluconazole structure has been replaced with 4-amino-5-aryl-3-mercapto-1,2,4-triazole motif. In this paper, we focused on the structural refinement of the primary lead, by removing the amino group from the structure to achieve 5-aryl-3-mercapto-1,2,4-triazole derivatives 10a-i and 11a-i. The in vitro antifungal susceptibility testing of title compounds demonstrated that most compounds had potent inhibitory activity against Candida species. Among them, 5-(2,4-dichlorophenyl)triazole analogs 10h and 11h with MIC values of <0.01 to 0.5μg/mL were 4-256 times more potent than fluconazole against Candida species.

  1. Evaluation of Use of a New Chromogenic Agar in Detection of Urinary Tract Pathogens

    PubMed Central

    Samra, Z.; Heifetz, M.; Talmor, J.; Bain, E.; Bahar, J.

    1998-01-01

    CHROMagar Orientation, a new chromogenic medium, was evaluated for the detection and differentiation of gram-positive and gram-negative pathogenic microorganisms in 900 urine samples from hospitalized patients. Performance characteristics of the medium were evaluated in comparison to those of 5% sheep blood and MacConkey agars by direct inoculation of the urine samples on the three media. Four gram-negative and two gram-positive strains as well as one yeast control strain from the American Type Culture Collection were used to ensure quality control. CHROMagar Orientation succeeded in detecting all the urine pathogens that were detected by the reference media, including gram-negative bacilli, staphylococci, streptococci, and yeasts. Colony color and morphology on CHROMagar Orientation accurately differentiated Escherichia coli, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, and Acinetobacter spp. Owing to the similarity in the pigmentation produced by Klebsiella, Enterobacter, and Citrobacter isolates, the medium failed to distinguish among them; however, these isolates were easily recognized as coliforms because of their metallic blue coloration. Staphylococci were clearly perceptible: S. aureus and S. epidermidis grow in regular-size colonies that range from opaque white to yellowish, and S. saprophyticus produces opaque pink colonies. All streptococcus strains, including those from groups B and C, were detected. They grow as undifferentiated flat dry diffused colonies, and additional tests were required for identification. Enterococci were easily discriminated by their strong turquoise pigmentation and their typical growth on the agar’s surface. Yeast grow in typical creamy wet convex colonies. The accuracy of antibiotic susceptibility determinations according to standard methods was also tested by picking isolates directly from CHROMagar Orientation. The results showed excellent correlation with those obtained with microorganisms picked from

  2. The Hsp90 Co-chaperones Sti1, Aha1, and P23 Regulate Adaptive Responses to Antifungal Azoles

    PubMed Central

    Gu, Xiaokui; Xue, Wei; Yin, Yajing; Liu, Hongwei; Li, Shaojie; Sun, Xianyun

    2016-01-01

    Heat Shock Protein 90 (Hsp90) is essential for tumor progression in humans and drug resistance in fungi. However, the roles of its many co-chaperones in antifungal resistance are unknown. In this study, by susceptibility test of Neurospora crassa mutants lacking each of 18 Hsp90/Calcineurin system member genes (including 8 Hsp90 co-chaperone genes) to antifungal drugs and other stresses, we demonstrate that the Hsp90 co-chaperones Sti1 (Hop1 in yeast), Aha1, and P23 (Sba1 in yeast) were required for the basal resistance to antifungal azoles and heat stress. Deletion of any of them resulted in hypersensitivity to azoles and heat. Liquid chromatography–mass spectrometry (LC-MS) analysis showed that the toxic sterols eburicol and 14α-methyl-3,6-diol were significantly accumulated in the sti1 and p23 deletion mutants after ketoconazole treatment, which has been shown before to led to cell membrane stress. At the transcriptional level, Aha1, Sti1, and P23 positively regulate responses to ketoconazole stress by erg11 and erg6, key genes in the ergosterol biosynthetic pathway. Aha1, Sti1, and P23 are highly conserved in fungi, and sti1 and p23 deletion also increased the susceptibility to azoles in Fusarium verticillioides. These results indicate that Hsp90-cochaperones Aha1, Sti1, and P23 are critical for the basal azole resistance and could be potential targets for developing new antifungal agents. PMID:27761133

  3. Antifungal and antibacterial activities of Taxus wallichiana Zucc.

    PubMed

    Nisar, Muhammad; Khan, Inamullah; Ahmad, Bashir; Ali, Ihsan; Ahmad, Waqar; Choudhary, Muhammad Iqbal

    2008-04-01

    Current study was undertaken to evaluate the in vitro antifungal and antibacterial potential of methanol extract and subsequent fractions obtained after partitioning in organic solvents with variable polarity of the aerial parts of the tree Taxus wallichiana Zucc. Traditionally, this plant is often used in folk medicines in Pakistan for treating microbial infections. In order to rationalize the traditional use, methanol extracts of leaf, bark, and heartwood of Taxus wallichiana Zucc. were tested against six bacteria and six fungal strains using the Hole diffusion and macro-dilution methods. All extracts and fractions displayed significant antimicrobial effect. Only three fungal strains, Trichophyton longifusus, Microspoum canis, and Fusarium solani were susceptible to the extracts and fractions with MICs ranging from 0.08 to 200 mg/mL. In case of bacterial strains, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi were susceptible to the extracts and fractions with MICs ranging from 0.08 to 200 mg/mL. Comparison results were carried out using imipinem, miconazole and amphotericin B as standard antibiotics. PMID:18343912

  4. Antifungal drug discovery: the process and outcomes

    PubMed Central

    Calderone, Richard; Sun, Nuo; Gay-Andrieu, Francoise; Groutas, William; Weerawarna, Pathum; Prasad, Sridhar; Alex, Deepu; Li, Dongmei

    2014-01-01

    New data suggest that the global incidence of several types of fungal diseases have traditionally been under-documented. Of these, mortality caused by invasive fungal infections remains disturbingly high, equal to or exceeding deaths caused by drug-resistant tuberculosis and malaria. It is clear that basic research on new antifungal drugs, vaccines and diagnostic tools is needed. In this review, we focus upon antifungal drug discovery including in vitro assays, compound libraries and approaches to target identification. Genome mining has made it possible to identify fungal-specific targets; however, new compounds to these targets are apparently not in the antimicrobial pipeline. We suggest that ‘repurposing’ compounds (off patent) might be a more immediate starting point. Furthermore, we examine the dogma on antifungal discovery and suggest that a major thrust in technologies such as structural biology, homology modeling and virtual imaging is needed to drive discovery. PMID:25046525

  5. 21 CFR 333.210 - Antifungal active ingredients.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Antifungal active ingredients. 333.210 Section 333.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Antifungal Drug Products § 333.210 Antifungal active ingredients. The active ingredient of the...

  6. 21 CFR 333.210 - Antifungal active ingredients.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Antifungal active ingredients. 333.210 Section 333.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Antifungal Drug Products § 333.210 Antifungal active ingredients. The active ingredient of the...

  7. 21 CFR 333.210 - Antifungal active ingredients.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Antifungal active ingredients. 333.210 Section 333.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Antifungal Drug Products § 333.210 Antifungal active ingredients. The active ingredient of the...

  8. 21 CFR 333.210 - Antifungal active ingredients.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Antifungal active ingredients. 333.210 Section 333.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Antifungal Drug Products § 333.210 Antifungal active ingredients. The active ingredient of the...

  9. 21 CFR 333.210 - Antifungal active ingredients.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Antifungal active ingredients. 333.210 Section 333.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Antifungal Drug Products § 333.210 Antifungal active ingredients. The active ingredient of the...

  10. Effect of Different Commerical Agar Preparations on the Inhibitory Activities of Phenols

    PubMed Central

    Sands, J. G.; Bennett, E. O.

    1966-01-01

    The minimal inhibitory concentrations of 11 phenolic inhibitors were compared in five commercial agars and in nutrient broth. It was found that the brand of agar affected the end point obtained for a particular inhibitor, and that the degree of antagonism varied with each compound studied. The results indicate that there are at least two deleterious factors present in agar, one of which is water-soluble and one which is not. The major portion of the total antagonism was due to the water-soluble factor, which could be removed by washing the agar in warm distilled water prior to use in the test medium. PMID:5959856

  11. Bacterial pathogens of otitis media and sinusitis: detection in the nasopharynx with selective agar media.

    PubMed

    Dudley, S; Ashe, K; Winther, B; Hendley, J O

    2001-11-01

    Carriage rates for the bacterial pathogens associated with otitis media (Streptococcus pneumoniae [SP], Hemophilus influenzae [HI], and Moraxella catarrhalis [MC]) are of interest. Culture on three selective agars was compared with culture on two standard agars to determine the more accurate method for detection of these species in the nasopharynx of healthy children. Weekly samples were obtained in winter from 18 healthy children (ages 1 through 9 years) as part of a longitudinal study. A 0.1-mL sample of 116 nasopharyngeal aspirate/washes was inoculated onto each of five agars. Two were standard (sheep blood and chocolate), and three were selective (blood with gentamicin for SP; chocolate with vancomycin, bacitracin, and clindamycin for HI; blood with amphotericin B, vancomycin, trimethoprim, and acetazolamide for MC). One technician read the standard plates and another the selective; both were blinded to the results of the other. SP was found in 44% of samples with selective agar versus 25% with standard agar; HI was found in 31% with selective versus 9% with standard; MC was found in 56% with selective versus 37% with standard. Overall, 80% of samples had one or more pathogens detected with selective agars as compared with 58% with standard agars (P =.0004). Selective agars were more accurate than standard agars for detecting otitis pathogens in the nasopharynx, where they are a common part of normal flora in healthy children.

  12. Residual Agar Determination in Bacterial Spores by Electrospray Ionization Mass Spectrometry

    SciTech Connect

    Wahl, Karen L.; Colburn, Heather A.; Wunschel, David S.; Petersen, Catherine E.; Jarman, Kristin H.; Valentine, Nancy B.

    2010-02-15

    Presented here is an analytical method to detect residual agar from a bacterial spore sample as an indication of culturing on an agar plate. This method is based on the resolubilization of agar polysaccharide from a bacterial spore sample, enzymatic digestion, followed by electrospray ionization tandem mass spectrometry (ESI-MSn) analysis for detection of a specific agar fragment ion. A range of Bacillus species and strains were selected to demonstrate the effectiveness of this approach. The characteristic agar fragment ion was detected in the spores grown on agar that were washed from 1 to 5 times, irradiated or non-irradiated and not in the spores grown in broth. A sample containing approximately 108 spores is currently needed for confident detection of residual agar from culture on agar plates in the presence of bacterial spores with a limit of detection of approximately 1 ppm agar spiked into a broth-grown spore sample. The results of a proficiency test with 42 blinded samples are presented demonstrating the utility of this method with no false positives and only 3 false negatives for samples that were below the detection level of the method as documented.

  13. Detection of toxigenic isolates of Aspergillus flavus and related species on coconut cream agar.

    PubMed

    Dyer, S K; McCammon, S

    1994-01-01

    A new readily-prepared medium, coconut cream agar, was developed for the detection of aflatoxin production by isolates of Aspergillus flavus and related species. Coconut cream agar, which comprised coconut cream (50%) and agar (1.5%), detected isolates of A. flavus more effectively than the synthetic media tested and was as effective as media containing desiccated coconut. Fluorescence colouring of colonies grown on coconut cream agar could be used to differentiate A. flavus from A. parasiticus and A. nomius. In addition, conidial colour of A. flavus and A. nomius was quite distinct from that of A. parasiticus.

  14. Antifungal and Antiproliferative Protein from Cicer arietinum: A Bioactive Compound against Emerging Pathogens

    PubMed Central

    Kumar, Suresh; Kapoor, Vaishali; Gill, Kamaldeep; Singh, Kusum; Xess, Immaculata; Das, Satya N.

    2014-01-01

    The emergence of epidemic fungal pathogenic resistance to current antifungal drugs has increased the interest in developing alternative antibiotics from natural sources. Cicer arietinum is well known for its medicinal properties. The aim of this work was to isolate antimicrobial proteins from Cicer arietinum. An antifungal protein, C-25, was isolated from Cicer arietinum and purified by gel filtration. C-25 protein was tested using agar diffusion method against human pathogenic fungi of ATCC strains and against clinical isolates of Candida krusei, Candida tropicalis, and Candida parapsilosis, and MIC values determined were varied from 1.56 to 12.5 μg/mL. The SEM study demonstrated that C-25 induces the bleb-like surface changes, irregular cell surface, and cell wall disruption of the fungi at different time intervals. Cytotoxic activity was studied on oral cancer cells and normal cells. It also inhibits the growth of fungal strains which are resistant to fluconazole. It reduced the cell proliferation of human oral carcinoma cells at the concentration of 37.5 μg/mL (IC50) and no toxic effect was found on normal human peripheral blood mononuclear cells even at higher concentration of 600 μg/mL. It can be concluded that C-25 can be considered as an effective antimycotic as well as antiproliferative agent against human oral cancer cells. PMID:24963482

  15. 2,3-Dideoxyglucosides of selected terpene phenols and alcohols as potent antifungal compounds.

    PubMed

    James Bound, D; Murthy, Pushpa S; Srinivas, P

    2016-11-01

    The antifungal activities of novel 2,3-unsaturated and 2,3-dideoxy 1-O-glucosides of carvacrol, thymol, and perillyl alcohol were tested against Aspergillus flavus, Aspergillus ochraceus, Fusarium oxysporum, Saccharomyces cerevisiae and Candida albicans. In the agar well diffusion tests, zones of inhibition for the derivatives of carvacrol, thymol and perillyl alcohol were higher (15-30mm) in the case of filamentous fungi than those for the parent compounds. Their MIC and MFC values indicated that the 2,3-unsaturated and 2,3-dideoxy 1-O-glucosides of carvacrol and thymol exhibited more fungicidal activity than the other compounds. Further, the 2,3-dideoxyglucosides of carvacrol and thymol, exhibited antitoxigenic effects against A. ochraceus and A. flavus and inhibited the production of ochratoxin and aflatoxin-B2. Propidium iodide influx assay demonstrated the lysis of C. albicans cells by carvacrol and its 2,3-unsaturated 1-O-glucoside and the loss of the membrane integrity. These new 2,3-dideoxyglucosides can be useful as antifungal agents and condiments in foods. PMID:27211660

  16. Antifungal and antiproliferative protein from Cicer arietinum: a bioactive compound against emerging pathogens.

    PubMed

    Kumar, Suresh; Kapoor, Vaishali; Gill, Kamaldeep; Singh, Kusum; Xess, Immaculata; Das, Satya N; Dey, Sharmistha

    2014-01-01

    The emergence of epidemic fungal pathogenic resistance to current antifungal drugs has increased the interest in developing alternative antibiotics from natural sources. Cicer arietinum is well known for its medicinal properties. The aim of this work was to isolate antimicrobial proteins from Cicer arietinum. An antifungal protein, C-25, was isolated from Cicer arietinum and purified by gel filtration. C-25 protein was tested using agar diffusion method against human pathogenic fungi of ATCC strains and against clinical isolates of Candida krusei, Candida tropicalis, and Candida parapsilosis, and MIC values determined were varied from 1.56 to 12.5 μg/mL. The SEM study demonstrated that C-25 induces the bleb-like surface changes, irregular cell surface, and cell wall disruption of the fungi at different time intervals. Cytotoxic activity was studied on oral cancer cells and normal cells. It also inhibits the growth of fungal strains which are resistant to fluconazole. It reduced the cell proliferation of human oral carcinoma cells at the concentration of 37.5 μg/mL (IC50) and no toxic effect was found on normal human peripheral blood mononuclear cells even at higher concentration of 600 μg/mL. It can be concluded that C-25 can be considered as an effective antimycotic as well as antiproliferative agent against human oral cancer cells.

  17. The non-Geldanamycin Hsp90 inhibitors enhanced the antifungal activity of fluconazole

    PubMed Central

    Li, Liping; An, Maomao; Shen, Hui; Huang, Xin; Yao, Xueya; Liu, Jian; Zhu, Fang; Zhang, Shiqun; Chen, Simin; He, Lijuan; Zhang, Jundong; Zou, Zui; Jiang, Yuanying

    2015-01-01

    The molecular chaperone heat shock protein 90 (Hsp90) is highly conserved in eukaryotes and facilitates the correct folding, productive assembly and maturation of a diverse cellular proteins. In fungi, especially the most prevalent human fungal pathogen Candida albicans, Hsp90 influences development and modulates drug resistance. Here, we mainly explore the effect of non-Geldanamycin Hsp90 inhibitor HSP990 on the activity of fluconazole (FLC) against Candida albicans and investigate the underlying mechanism. We demonstrate that HSP990 has potent synergistic antifungal activity with FLC against FLC-resistant C. albicans through the checkerboard microdilution assay,agar diffusion tests and time-kill curves, and shows low cytotoxicity to human umbilical vein endothelial cells. Further study shows that the activity of FLC against C. albicans biofilm formation in vitro is significantly enhanced when used in combination with HSP990. In a murine model of disseminated candidiasis, the therapeutic efficacy of FLC is also enhanced by the pharmacological inhibition of C. albicans Hsp90 function with HSP990. Thus, the combined use of small molecule compound and existing antifungal drugs may provide a potential therapeutic strategy for fungal infectious disease. PMID:26885259

  18. Cell viability of Candida albicans against the antifungal activity of thymol.

    PubMed

    de Vasconcelos, Laís César; Sampaio, Fabio Correia; Albuquerque, Allan de Jesus dos Reis; Vasconcelos, Laurylene César de Souza

    2014-01-01

    Candida albicans is a commensal fungus, but circumstantially it may cause superficial infections of the mucous membranes, such as denture stomatitis, when a biofilm is formed on the surface of dental prostheses. This study evaluated the cell viability of C. albicans biofilms against the antifungal activity of thymol when compared with miconazole, by the fluorescence imaging using SYTO 9 and propidium iodide dyes, and counting of colony forming units. C. albicans standard strains (ATCC 11006) were used. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of drugs were determined by broth microdilution tests and the inoculum was standardized to match 0.5 on the McFarland scale (106 cfu/mL). Biofilms were grown on the surface of acrylic resin disks in parallel flow chambers from Sabouraud broth supplemented with 10% dextrose. For counting of colony forming units, the fungal solution was sequentially diluted and plated in Sabouraud dextrose agar. Data were analyzed using two-way ANOVA and Tukey's test (a=5%). Biofilms treated with thymol and miconazole presented low numbers of viable cells at the evaluated exposure times. There was statistically significant difference (p<0.05) when compared with control, and the mean value of the exposure times between miconazole and thymol did not differ significantly (p>0.05). In conclusion, both drugs have similar efficiency as antifungal agents against biofilms of C. albicans formed on acrylic surfaces. PMID:25250489

  19. Functional properties and antifungal activity of films based on gliadins containing cinnamaldehyde and natamycin.

    PubMed

    Balaguer, Mari Pau; Fajardo, Paula; Gartner, Hunter; Gomez-Estaca, Joaquin; Gavara, Rafael; Almenar, Eva; Hernandez-Munoz, Pilar

    2014-03-01

    Gliadin films cross-linked with cinnamaldehyde (1.5, 3, and 5%) and incorporated with natamycin (0.5%) were prepared by casting, and their antifungal activity, water resistance, and barrier properties were characterized. Incorporation of natamycin gave rise to films with greater water uptake, weight loss and diameter gain, and higher water vapor and oxygen permeabilities. These results may be associated to a looser packing of the protein chains as a consequence of the presence of natamycin. The different cross-linking degree of the matrices influenced the natamycin migration to the agar test media, increasing from 13.3 to 23.7 (μg/g of film) as the percentage of cinnamaldehyde was reduced from 5% to 1.5%. Antifungal activity of films was assayed against common food spoilage fungi (Penicillium species, Alternaria solani, Colletotrichum acutatum). The greatest effectiveness was obtained for films containing natamycin and treated with 5% of cinnamaldehyde. The level of cinnamaldehyde reached in the head-space of the test assay showed a diminishing trend as a function of time, which was in agreement with fungal growth and cinnamaldehyde metabolization. Developed active films were used in the packaging of cheese slices showing promising results for their application in active packaging against food spoilage. PMID:24412960

  20. Antifungal activity of the aqueous extract of Ilex paraguariensis against Malassezia furfur.

    PubMed

    Filip, Rosana; Davicino, Roberto; Anesini, Claudia

    2010-05-01

    Malassezia furfur is a lipodependent, dimorphic and saprophyte fungus which causes pityriasis versicolor, dandruff and seborrheic dermatitis in humans. The drugs available to treat this fungal infection are few. These drugs are highly toxic and are costly when used in prolonged treatments. For these reasons, it is necessary to find new compounds to treat these infections. Ilex paraguariensis St Hilaire is a plant that grows in Argentina, Brazil and Paraguay. The aim of this study was to evaluate the effect of the aqueous extract of Ilex paraguariensis on the growth of M. furfur. High performance liquid chromatography (HPLC) was employed to identify and isolate compounds of I. paraguariensis and the agar-well diffusion method was used to assess the antifungal activity of the extract. The fungicidal/fungistatic effect was evaluated by the modified Thompson assay. The results demonstrated that the aqueous extract of Ilex paraguariensis (1000 mg/ml) possesses inhibitory activity against M. furfur. This antimalassezial activity was equivalent to 2.7 microg/ml of ketoconazole. Therefore, the topical use of Ilex paraguariensis extract as alternative antifungal agent can be suggested. PMID:19827026

  1. Laccase Catalyzed Synthesis of Iodinated Phenolic Compounds with Antifungal Activity

    PubMed Central

    Ihssen, Julian; Schubert, Mark; Thöny-Meyer, Linda; Richter, Michael

    2014-01-01

    Iodine is a well known antimicrobial compound. Laccase, an oxidoreductase which couples the one electron oxidation of diverse phenolic and non-phenolic substrates to the reduction of oxygen to water, is capable of oxidizing unreactive iodide to reactive iodine. We have shown previously that laccase-iodide treatment of spruce wood results in a wash-out resistant antimicrobial surface. In this study, we investigated whether phenolic compounds such as vanillin, which resembles sub-structures of softwood lignin, can be directly iodinated by reacting with laccase and iodide, resulting in compounds with antifungal activity. HPLC-MS analysis showed that vanillin was converted to iodovanillin by laccase catalysis at an excess of potassium iodide. No conversion of vanillin occurred in the absence of enzyme. The addition of redox mediators in catalytic concentrations increased the rate of iodide oxidation ten-fold and the yield of iodovanillin by 50%. Iodinated phenolic products were also detected when o-vanillin, ethyl vanillin, acetovanillone and methyl vanillate were incubated with laccase and iodide. At an increased educt concentration of 0.1 M an almost one to one molar ratio of iodide to vanillin could be used without compromising conversion rate, and the insoluble iodovanillin product could be recovered by simple centrifugation. The novel enzymatic synthesis procedure fulfills key criteria of green chemistry. Biocatalytically produced iodovanillin and iodo-ethyl vanillin had significant growth inhibitory effects on several wood degrading fungal species. For Trametes versicolor, a species causing white rot of wood, almost complete growth inhibition and a partial biocidal effect was observed on agar plates. Enzymatic tests indicated that the iodinated compounds acted as enzyme responsive, antimicrobial materials. PMID:24594755

  2. Antifungal activity and acute toxicity of stem bark extracts of Drypetes gossweileri S. Moore-euphorbiaceae from Cameroon.

    PubMed

    Ngouana, Vincent; Fokou, Patrick Valère Tsouh; Foudjo, Brice Ulrich Saha; Ngouela, Silvère Augustin; Boyom, Fabrice Fekam; Zollo, Paul Henri Amvam

    2011-01-01

    Drypetes gossweilleri S. Moore is a plant used in traditional medicine in Cameroon. The antifungal properties of its stem-bark crude extract and fractions DG(1), DG(2), DG(3), DG(4), DG(5), DG(6), DG(7), DG(8) and DG(9) were assayed by agar and broth dilution methods on solid and liquid media against C. Krusei, C. albicans, C. glabrata, T. mentagerophytes, M. langeroinii, M. gypeum, M. audouini, T. rubrum, T. soudanense, T. terrestre, A. flavus and A. niger. The results revealed a substantial antifungal effect with minimal inhibitory concentrations ranging respectively from 24.11µg/ml to 1562µg/ml for yeasts and from 3125µg/ml to 12500µg/ml for filamentous fungi. Among the fractions, fraction DG4 exerted the highest antifungal activity. Moreover, no toxic effect was noticed in male and female albinos Wistar rats treated per os with the crude stem bark's extract of Drypetes gossweileri at a dose up to 12g/kg of body weight. The phytochemical screening of the crude extract and fractions showed the presence of alkaloids, phenols, flavonoids, saponins, anthocyanines, anthraquinones, sterols, lipids and essential oils. Therefore, Drypetes gossweileri may be safe as phytomedecine for the treatment of fungal infections. PMID:22468013

  3. Essential oil composition and antifungal activity of aerial parts of Ballota nigra ssp foetida collected at flowering and fruiting times.

    PubMed

    Fraternale, Daniele; Ricci, Donata

    2014-07-01

    The present study reports the results of gas chromatographic-mass spectrometric (GC/MS) analyses of the essential oils from the aerial parts of Ballota nigra L. ssp foetida (Lamiaceae) collected at flowering and fruiting times, as well as their in vitro antifungal activity against nine plant pathogenic fungi. Moreover, the essential oils were evaluated for their antifungal activity using the agar dilution method, and also MICs (minimum inhibitory concentrations) and MFCs (minimum fungicidal concentrations) were determined. The major compounds identified in the flowering and fruiting aerial parts oils respectively were beta-caryophyllene (22.6% and 21.8%), caryophyllene oxide (18.0% and 20.5%) and germacrene-D (16.5 and 13.1%). The oils showed in vitro antifungal activity against some species of Fusarium, Botrytis cinerea, and Alternaria solani. Our study indicates that the oil of B. nigra ssp foetida could be used as a control agent for plant pathogenic fungi in natural formulations. PMID:25230517

  4. Glucose-sucrose-potassium tellurite-bacitracin agar, an alternative to mitis salivarius-bacitracin agar for enumeration of Streptococcus mutans.

    PubMed Central

    Tanzer, J M; Börjesson, A C; Laskowski, L; Kurasz, A B; Testa, M

    1984-01-01

    An agar medium for selective recovery and enumeration of Streptococcus mutans was developed as an alternative to mitis salivarius-bacitracin (MSB) agar. Combinations of dyes, antibiotics, and tellurite were added to a nonselective medium which, because of its sucrose content, allowed easy recognition of S. mutans colonies. Candle jar incubation for 2 days, by comparison with anaerobic incubation, reduced background flora but did not diminish S. mutans recoveries from clinical samples. Quantitative comparisons were made of the simultaneous recoveries of a number of authentic S. mutans serotype representatives and fresh clinical isolates, using various glucose-sucrose-potassium tellurite-bacitracin (GSTB) formulations and mitis salivarius, MSB, and blood agars. Mitis salivarius counts were not detectably different from blood counts, but counts on MSB were distinctly lower. A formulation of the new medium containing 5% glucose 5% sucrose, 0.001% potassium tellurite, 0.3 U of bacitracin per ml (hence GSTB), and 2% agar gave recoveries nearly equal to those on mitis salivarius agar and much greater than those on MSB. The medium yielded readily recognized S. mutans colonies and facilitated detection of intracellular polysaccharide formers upon flooding with I2 reagent. Freshly isolated serotype c, E, and f colonies could often be distinguished from serotype d and g colonies, a distinction made reliable by testing for intracellular polysaccharide. A study of 300 salivary samples revealed GSTB to give significantly higher recoveries than MSB. About 72% of all samples were substantially underestimated for S. mutans with MSB, and 6.7% of samples were falsely negative for S. mutans with MSB. Recovery of background flora on GSTB was as low or lower than on MSB, and both types of agar could be stored for at least 9 weeks without notable change of selectivity. Thus, GSTB agar appears to be simple and reliable to use and requires no anaerobic incubation. Caution is voiced about

  5. Antifungal activities of the essential oils in Syzygium aromaticum (L.) Merr. Et Perry and Leptospermum petersonii Bailey and their constituents against various dermatophytes.

    PubMed

    Park, Mi-Jin; Gwak, Ki-Seob; Yang, In; Choi, Won-Sil; Jo, Hyun-Jin; Chang, Je-Won; Jeung, Eui-Bae; Choi, In-Gyu

    2007-10-01

    This study was carried out in order to investigate the potential of using plant oils derived from Leptospermum petersonii Bailey and Syzygium aromaticum L. Merr. Et Perry as natural antifungal agents. The antifungal effects of essential oils at concentrations of 0.05, 0.1, 0.15, and 0.2 mg/ml on the dermatophytes Microsporum canis (KCTC 6591), Trichophyton mentagrophytes (KCTC 6077), Trichophyton rubrum (KCCM 60443), Epidermophyton floccosum (KCCM 11667), and Microsporum gypseum were evaluated using the agar diffusion method. The major constituents of the active fraction against the dermatophytes were identified by gas chromatography-mass spectrometry and high-performance liquid chromatography analysis. The antifungal activities of S. aromaticum oil (clove oil) against the dermatophytes tested were highest at a concentration of 0.2 mg/ml, with an effectiveness of more than 60%. Hyphal growth was completely inhibited in T. mentagrophytes, T. rubrum, and M. gypseum by treatment with clove oil at a concentration of 0.2 mg/ml. Eugenol was the most effective antifungal constituent of clove oil against the dermatophytes T. mentagrophytes and M. canis. Morphological changes in the hyphae of T. mentagrophytes, such as damage to the cell wall and cell membrane and the expansion of the endoplasmic reticulum, after treatment with 0.11 mg/ml eugenol were observed by transmission electron microscopy (TEM). At a concentration of 0.2 mg/ml, L. petersonii oil (LPO) was more than 90% effective against all of the dermatophytes tested, with the exception of T. rubrum. Geranial was determined to be the most active antifungal constituent of L. petersonii oil. Taken together, the results of this study demonstrate that clove and tea tree oils exhibited significant antifungal activities against the dermatophytes tested in this study.

  6. Cinnamaldehyde and its derivatives, a novel class of antifungal agents.

    PubMed

    Shreaz, Sheikh; Wani, Waseem A; Behbehani, Jawad M; Raja, Vaseem; Irshad, Md; Karched, Maribasappa; Ali, Intzar; Siddiqi, Weqar A; Hun, Lee Ting

    2016-07-01

    The last few decades have seen an alarming rise in fungal infections, which currently represent a global health threat. Despite extensive research towards the development of new antifungal agents, only a limited number of antifungal drugs are available in the market. The routinely used polyene agents and many azole antifungals are associated with some common side effects such as severe hepatotoxicity and nephrotoxicity. Also, antifungal resistance continues to grow and evolve and complicate patient management, despite the introduction of new antifungal agents. This suitation requires continuous attention. Cinnamaldehyde has been reported to inhibit bacteria, yeasts, and filamentous molds via the inhibition of ATPases, cell wall biosynthesis, and alteration of membrane structure and integrity. In this regard, several novel cinnamaldehyde derivatives were synthesized with the claim of potential antifungal activities. The present article describes antifungal properties of cinnamaldehyde and its derivatives against diverse classes of pathogenic fungi. This review will provide an overview of what is currently known about the primary mode of action of cinnamaldehyde. Synergistic approaches for boosting the effectiveness of cinnamaldehyde and its derivatives have been highlighted. Also, a keen analysis of the pharmacologically active systems derived from cinnamaldehyde has been discussed. Finally, efforts were made to outline the future perspectives of cinnamaldehyde-based antifungal agents. The purpose of this review is to provide an overview of current knowledge about the antifungal properties and antifungal mode of action of cinnamaldehyde and its derivatives and to identify research avenues that can facilitate implementation of cinnamaldehyde as a natural antifungal. PMID:27259370

  7. Antifungal activity of ajoene derived from garlic.

    PubMed

    Yoshida, S; Kasuga, S; Hayashi, N; Ushiroguchi, T; Matsuura, H; Nakagawa, S

    1987-03-01

    The antifungal activity of six fractions derived from garlic was investigated in an in vitro system. Ajoene had the strongest activity in these fractions. The growth of both Aspergillus niger and Candida albicans was inhibited by ajoene at less than 20 micrograms/ml.

  8. Efflux-Mediated Antifungal Drug Resistance†

    PubMed Central

    Cannon, Richard D.; Lamping, Erwin; Holmes, Ann R.; Niimi, Kyoko; Baret, Philippe V.; Keniya, Mikhail V.; Tanabe, Koichi; Niimi, Masakazu; Goffeau, Andre; Monk, Brian C.

    2009-01-01

    Summary: Fungi cause serious infections in the immunocompromised and debilitated, and the incidence of invasive mycoses has increased significantly over the last 3 decades. Slow diagnosis and the relatively few classes of antifungal drugs result in high attributable mortality for systemic fungal infections. Azole antifungals are commonly used for fungal infections, but azole resistance can be a problem for some patient groups. High-level, clinically significant azole resistance usually involves overexpression of plasma membrane efflux pumps belonging to the ATP-binding cassette (ABC) or the major facilitator superfamily class of transporters. The heterologous expression of efflux pumps in model systems, such Saccharomyces cerevisiae, has enabled the functional analysis of efflux pumps from a variety of fungi. Phylogenetic analysis of the ABC pleiotropic drug resistance family has provided a new view of the evolution of this important class of efflux pumps. There are several ways in which the clinical significance of efflux-mediated antifungal drug resistance can be mitigated. Alternative antifungal drugs, such as the echinocandins, that are not efflux pump substrates provide one option. Potential therapeutic approaches that could overcome azole resistance include targeting efflux pump transcriptional regulators and fungal stress response pathways, blockade of energy supply, and direct inhibition of efflux pumps. PMID:19366916

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

    PubMed Central

    ALASTRUEY-IZQUIERDO, Ana; MELHEM, Marcia S.C.; BONFIETTI, Lucas X.; RODRIGUEZ-TUDELA, Juan L.

    2015-01-01

    SUMMARY 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. PMID:26465371

  10. Antifungal drug resistance pattern of Candida. spp isolated from vaginitis in Ilam-Iran during 2013-2014

    PubMed Central

    Mohamadi, Jasem; Havasian, Mohamad Reza; Panahi, Jafar; Pakzad, Iraj

    2015-01-01

    Vaginal Candidiasis is the most common and important opportunistic fungal infection in women. By increasing use of antifungal drugs in recent years, it has caused drug resistance. This study aims to evaluate antifungal drugs susceptibility of Candida. spp isolated of women with vaginitis from Ilam-Iran during 2013-2014. samples were collected and cultured from 385 women with vaginitis, then Candida.spp was diagnosed by standard method. Antifungal drug susceptibility test for nystatin 100 unit/disk, fluconazole 10µg/disk, itraconazole 10µg/disk, ketoconazole 10µg/disk, amphotericinB 20µg/disk, clotrimazole 10µg/disk, posaconazole 5µg/disk, and voriconazole 1µg/disk were carried out by M44-A method(CLSI). From all culture positive samples, 150 isolates were Candida albicans and 89 isolates were non-albicans. The resistance to fluconazole, itraconazole, ketoconazole, clotrimazole, voriconazole, posaconazole, nystatin and amphotericin B was 76%, 62%, 72%, 55%, 6%, 7%, 1% and 0%. The highest resistance was seen for fluconazole , itraconazole, and the highest susceptible was seen for nystatin and amphotericin B. These results indicate nystatin and amphotericin B can be used as the first line for empirical therapy of vaginal candidiasis in the district. PMID:26124561

  11. Evaluation of antifungal activity in essential oil of the Syzygium aromaticum (L.) by extraction, purification and analysis of its main component eugenol

    PubMed Central

    Rana, Inder Singh; Rana, Aarti Singh; Rajak, Ram Charan

    2011-01-01

    Antifungal properties of some essential oils have been well documented. Clove oil is reported to have strong antifungal activity against many fungal species. In this study we have evaluated antifungal potential of essential oil of Syzygium aromaticum (L.) against some common fungal pathogens of plants and animals namely, Fusarium moniliforme NCIM 1100, Fusarium oxysporum MTCC 284, Aspergillus sp., Mucor sp., Trichophyton rubrum and Microsporum gypseum. All fungal species were found to be inhibited by the oil when tested through agar well diffusion method. Minimum inhibitory concentration (MIC) was determined for all the species. Column chromatography was performed to separate the eugenol rich fraction from clove oil. Out of seven fractions maximum activity was obtained in column fraction II. TLC and HPLC data confirmed presence of considerable Eugenol in fraction II and clove oil. Microscopic study on effect of clove oil and column fraction II on spores of Mucor sp. and M. gypseum showed distortion and shrinkage while it was absent in other column fractions. So it can be concluded that the antifungal action of clove oil is due to its high eugenol content. PMID:24031751

  12. Evaluation of antifungal activity in essential oil of the Syzygium aromaticum (L.) by extraction, purification and analysis of its main component eugenol.

    PubMed

    Rana, Inder Singh; Rana, Aarti Singh; Rajak, Ram Charan

    2011-10-01

    Antifungal properties of some essential oils have been well documented. Clove oil is reported to have strong antifungal activity against many fungal species. In this study we have evaluated antifungal potential of essential oil of Syzygium aromaticum (L.) against some common fungal pathogens of plants and animals namely, Fusarium moniliforme NCIM 1100, Fusarium oxysporum MTCC 284, Aspergillus sp., Mucor sp., Trichophyton rubrum and Microsporum gypseum. All fungal species were found to be inhibited by the oil when tested through agar well diffusion method. Minimum inhibitory concentration (MIC) was determined for all the species. Column chromatography was performed to separate the eugenol rich fraction from clove oil. Out of seven fractions maximum activity was obtained in column fraction II. TLC and HPLC data confirmed presence of considerable Eugenol in fraction II and clove oil. Microscopic study on effect of clove oil and column fraction II on spores of Mucor sp. and M. gypseum showed distortion and shrinkage while it was absent in other column fractions. So it can be concluded that the antifungal action of clove oil is due to its high eugenol content. PMID:24031751

  13. Use of cefoperazone MacConkey agar for selective isolation of Laribacter hongkongensis.

    PubMed

    Lau, Susanna K P; Woo, Patrick C Y; Hui, Wai-ting; Li, Maria W S; Teng, Jade L L; Que, Tak-Lun; Luk, Wei-Kwang; Lai, Raymond W M; Yung, Raymond W H; Yuen, Kwok-yung

    2003-10-01

    A new selective medium, cefoperazone MacConkey agar (CMA), was developed for primary isolation of Laribacter hongkongensis from stool. Its performance in quantitative recovery and in a clinical evaluation of 4,741 human diarrheal stool specimens was superior to that of charcoal cefoperazone deoxycholate agar. In addition, with CMA, Arcobacter butzleri was unexpectedly isolated from the stools of six patients.

  14. Evaluation of a chromogenic agar for detection of group B streptococcus in pregnant women.

    PubMed

    Craven, Robin R; Weber, Carol J; Jennemann, Rebecca A; Dunne, W Michael

    2010-09-01

    We compared ChromID Strepto B agar (STRB; bioMérieux, Inc.), a selective and differential medium for group B streptococcus, with culture using neomycin-nalidixic acid agar (NNA) and LIM broth. STRB alone was more sensitive (87.7%) than NNA alone (79.0%), while each had a sensitivity of 100% when used in conjunction with LIM broth.

  15. Effect of refrigerated storage on cefaclor in Mueller-Hinton agar.

    PubMed Central

    Surprenant, A M; Preston, D A

    1985-01-01

    Cefaclor is less stable than most cephalosporins in media at 35 degrees C. We demonstrated that the activity of cefaclor in Mueller-Hinton agar diminishes continuously at 4 degrees C, resulting in a loss of two-thirds of the activity within 21 days. We recommend that agar dilution plates for this cephalosporin be prepared on the day of their use. PMID:3968200

  16. Agar composition affects in vitro screening of biocontrol activity of antagonistic microorganisms.

    PubMed

    Bosmans, L; De Bruijn, I; De Mot, R; Rediers, H; Lievens, B

    2016-08-01

    Agar-based screening assays are the method of choice when evaluating antagonistic potential of bacterial biocontrol-candidates against pathogens. We showed that when using the same medium, but different agar compositions, the activity of a bacterial antagonist against Agrobacterium was strongly affected. Consequently, results from in vitro screenings should be interpreted cautiously. PMID:27166668

  17. High Concentrations of Manganese in Mueller-Hinton Agar Increase MICs of Tigecycline Determined by Etest▿

    PubMed Central

    Fernández-Mazarrasa, Carlos; Mazarrasa, Olav; Calvo, Jorge; del Arco, Asunción; Martínez-Martínez, Luis

    2009-01-01

    MICs of tigecycline determined by Etest were 4 to 12 times (three ATCC strains) and 2 to 8 times (50 clinical isolates) higher in Mueller-Hinton agar from Merck than in Mueller-Hinton agar from either Oxoid or Difco. This was related to a much higher concentration of manganese in the medium from Merck. PMID:19144806

  18. Effects of season on the yield and quality of agar from Gracilaria species (Gracilariaceae, Rhodophyta).

    PubMed

    Marinho-Soriano, E; Bourret, E

    2003-12-01

    The effect of season on yield and physical properties of agars extracted from Gracia gracilis and G. bursa-pastoris were determined. The agar yield from G. gracilis was maximum during spring (30%) and minimum during autumn (19%). In G. bursa-pastoris, the agar yield was greatest in summer (36%) and lowest in winter (23%). Agar yield from G. bursa-pastoris was positively correlated with temperature (r=0.94; P<0.01) and salinity (r=0.97; P<0.01) and negatively with nitrogen content (r=-0.93; P<0.01). Agar gel strengths fluctuated from 229 to 828 gcm(-2) and 23 to 168 gcm(-2) for G. gracilis and G. bursa-pastoris, respectively. The gelling temperature showed significant seasonal variation for both species. Chemical analysis of agar from the two seaweeds indicated variation in 3,6-anhydrogalactose and sulfate content (P<0.01). Furthermore, there was an inverse correlation between the two chemical variables. In general, agar extracted from G. gracilis possessed better qualities than agar extracted from G. bursa-pastoris and can be considered a candidate for industrial use.

  19. Development of novel agar media for isolating guaiacol producing Alicyclobacillus spp.

    PubMed

    Chang, S S; Park, S H; Kang, D H

    2013-06-01

    The purpose of this study is to develop a selective and differential medium (SK2 agar) for isolating guaiacol producing Alicyclobacillus. Forty-one selected dyes and vanillic acid were incorporated in SK agar for screening selective and differential agents. Two guaiacol producing (1016, 1101) and two non-guaiacol producing (19220, C-GD 1-1) Alicyclobacillus isolates were streaked onto media and color differentiation of the isolates was assessed. Among 41 tested dyes, Chrome Azurol S (CAS) allowed color differentiation of the two types of Alicyclobacillus. Colonies of guaiacol producing Alicyclobacillus isolates appeared as dark purple to royal blue color with yellow background, whereas non-guaiacol producing Alicyclobacillus isolates produced cream colored colonies with yellow background. Vanillic acid not only served as a precursor for guaiacol formation but also inhibited non-guaiacol producing Alicyclobacillus. Non-guaiacol producing isolates did not grow on SK agar containing more than 70 ppm vanillic acid, whereas the recovery of guaiacol producing isolates was unaffected. When compared with other Alicyclobacillus isolation media, not only was SK2 agar capable of selectively recovering guaiacol-producing Alicyclobacillus, the degree of growth was also approximately equal if not better than orange serum agar, potato dextrose agar, and K agar. The development of SK2 agar provides the fruit juice industry with an inexpensive, simple to use alternative for the detection of guaiacol producing Alicyclobacillus.