WorldWideScience

Sample records for antifungal susceptibility testing

  1. Spectrophotometric reading of EUCAST antifungal susceptibility testing of Aspergillus fumigatus

    NARCIS (Netherlands)

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

    2017-01-01

    OBJECTIVES: Given the increasing number of antifungal drugs and the emergence of resistant Aspergillus isolates, objective, automated and high-throughput antifungal susceptibility testing is important. The EUCAST E.Def 9.3 reference method for MIC determination of Aspergillus species relies on

  2. Methodological Issues in Antifungal Susceptibility Testing of Malassezia pachydermatis

    Science.gov (United States)

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

    2017-01-01

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

  3. Antifungal susceptibility testing for yeasts: how, when and why, according to the new EUCAST guidelines

    Directory of Open Access Journals (Sweden)

    Esther Manso

    2011-03-01

    Full Text Available Antifungal susceptibility testing of yeasts and the development of interpretive breakpoints are nowadays very important topics both for the increasing incidence of invasive mycoses and number of available antifungal drugs and for the appearance of acquired resistance. The Subcommittee on Antifungal Susceptibility Testing (AFST of the European Committee on Antibiotic Susceptibility Testing (EUCAST has recently released both the operative standards to evaluate the fermenting yeasts susceptibility against antimycotic drugs and the breakpoints for infections due to some Candida species and for some of the available antifungals. Antifungal susceptibility testing is mandatory on a routine base for: 1. therapeutic failure, 2. breakthrough fungemias, 3. on yeasts isolated from patients who recently received prophylactic antifungal treatments, and 4. when the deep-seated infection is due to less common yeasts, with an unknown susceptibility pattern. The Medical Mycology Committee (CoSM of the Italian Society of Clinical Microbiologists (AMCLI adopted the interpretive breakpoints of both CLSI and EUCAST. The operating procedure for antifungal susceptibility testing according to EUCAST is supported by the recommendation to use, when clinically necessary, validated commercial methods (Vitek2, Sensititre, E-test. Finally, the CoSM reports the recommendations for a correct management of antifungal susceptibility testing.

  4. Spectrophotometric reading of EUCAST antifungal susceptibility testing of Aspergillus fumigatus

    DEFF Research Database (Denmark)

    Meletiadis, J.; Leth Mortensen, K.; Verweij, P. E.

    2017-01-01

    Objectives Given the increasing number of antifungal drugs and the emergence of resistant Aspergillus isolates, objective, automated and high-throughput antifungal susceptibility testing is important. The EUCAST E.Def 9.3 reference method for MIC determination of Aspergillus species relies on vis...

  5. Evaluation of semisolid agar method for antifungal susceptibility test of T. rubrum

    Directory of Open Access Journals (Sweden)

    Sultana Razia

    2016-08-01

    Full Text Available Background: With increasing fungal disease many newer antifungal drugs are available with different spectrum of activ­ity. Antifungal susceptibility test will help clinicians for selection of effective drug and thereby treatment of patient. Objective: The study was undertaken to perform a simple screening drug susceptibility test of T. rnbrum by Semi Solid Agar Antifungal Susceptibility (SAAS Method: Perfonnance of susceptibility method was assessed by comparing the MICs of three commonly prescribed antifungal agents namely- tluconazole (FCZ, itraconazole (ITZ and terbinafine (TER to the CLSI (Clinical and Laboratory Standard Institute recommended M-38, a broth microdilution method. Results: In SAAS method, among twenty nine T. rubrum, twenty five (86.2% were susceptible (MIC range 0.5-64 µg/ml to Fluconazole (FCZ and four (13.7% were resistant (MIC value >64 µg/ml. In broth microdilution method, among twenty nine T. rubrum, twenty six (89.6% were susceptible (MIC range 0.3-64 µg/ml to FCZ and three (10.3% were resistant (MIC value >64 µg/ml. In case of both ITZ and TER, all were susceptible (MIC range 0.3-64 µg/ml to both methods. The SAAS method demonstrated the susceptibility pattern of T. rubrum against FCZ, ITZ and TER usually within 72 to 96 hours after organism isolation and results were concordance with the results of CLSI broth microdilution method. Conclusion: Though it is a newer method with proper standardization of the test method, SAAS method is simple and easily applicable screening method for susceptibility testing of antifungal agents against dermatophytes in any microbiology laboratories.

  6. Flow cytometry susceptibility testing for conventional antifungal drugs and Comparison with the NCCLS Broth Macrodilution Test

    Directory of Open Access Journals (Sweden)

    M.J. Najafzadeh

    2009-08-01

    Full Text Available Introduction: During the last decade, the incidence of fungal infection has been increased in many countries. Because of the advent of resistant to antifungal agents, determination of an efficient strategic plan for treatment of fungal disease is an important issue in clinical mycology. Many methods have been introduced and developed for determination of invitro susceptibility tests. During the recent years, flow cytometry has developed to solving the problem and many papers have documented the usefulness of this technique. Materials and methods: As the first step, the invitro susceptibility of standard PTCC (Persian Type of Culture Collection strain and some clinical isolates of Candida consisting of Candida albicans, C. dubliniensis, C. glabrata, C. kefyer and C. parapsilosis were evaluated by macrodilution broth method according to NCCLS (National Committee for Clinical Laboratory Standards guidelines and flow cytometry susceptibility test. Results:  The data indicated that macro dilution broth methods and flow cytometry have the same results in determination of MIC (Minimum Inhibitory Concentration for amphotericin B, clotrimazole, fluconazole, ketoconazole and miconazole in C. albicans PTCC 5027 as well as clinical Candida isolates, such as C.albicans, C.dubliniensis, C.glabrata C.kefyr, and C.parapsilosis. Discussion: Comparing the results obtained by macrodilution broth and flow cytometry methods revealed that flow cytometry was faster. It is suggested that flow cytometry susceptibility test can be used as a powerful tool for determination of MIC and administration of the best antifungal drug in treatment of patients with Candida infections.

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

    Science.gov (United States)

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

    2017-02-01

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

  8. .i.Aspergillus viridinutans./i. complex: polyphasic taxonomy, mating behaviour and antifungal susceptibility testing

    Czech Academy of Sciences Publication Activity Database

    Dudová, Z.; Hubka, V.; Svobodová, L.; Hamal, P.; Nováková, Alena; Matsuzawa, T.; Yaguchi, T.; Kubátová, A.; Kolařík, Miroslav

    2013-01-01

    Roč. 56, Suppl. 3 (2013), s. 162-163 ISSN 0933-7407. [Trends in Medical Mycology /6./. 11.10.2013-14.10.2013, Copenhagen] Institutional support: RVO:60077344 ; RVO:61388971 Keywords : Aspergillus viridinutans * polyphasic taxonomy * mating behaviour * antifungal susceptibility testing Subject RIV: EE - Microbiology, Virology

  9. Antifungal susceptibility testing of Candida species isolated from the immunocompromised patients admitted to ten university hospitals in Iran

    NARCIS (Netherlands)

    Badiee, P.; Badali, H.; Boekhout, T.; Diba, K.; Moghadam, A.G.; Hossaini Nasab, A.; Jafarian, H.; Mohammadi, R.; Mirhendi, H.; Najafzadeh, M.J.; Shamsizadeh, A.; Soltani, J.

    2017-01-01

    Background Antifungal susceptibility testing is a subject of interest in the field of medical mycology. The aim of the present study were the distributions and antifungal susceptibility patterns of various Candida species isolated from colonized and infected immunocompromised patients admitted to

  10. Antifungal susceptibility and test for cure of candida species among ...

    African Journals Online (AJOL)

    Contexte: La résistance aux antimicrobiens chez les espèces de Candida est un problème de santé publique intense. L'objectif de l'étude était de déterminer le schéma de susceptibilité aux antifongiques et le test de guérison des espèces de Candida parmi les femmes en âge de procréer qui ont visité l'hôpital général de ...

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

    Science.gov (United States)

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

    2017-06-01

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

  12. Antifungal susceptibility testing of vaginal candida isolates: the broth microdilution method

    Directory of Open Access Journals (Sweden)

    Mahmoudi Rad M

    2010-02-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Vulvovaginal candidiasis is a common mucosal infection among immunocompetent, healthy women, and is caused by opportunistic yeasts that belong to genus Candida. In this study, we isolated and identified the Candida species in the vagina of patients who admitted in Gynecology Department of Mahdieh Hospital in Tehran, Iran to evaluate the in vitro activities of fluconazole, miconazole, itraconazole and flucytosine against 191 clinical Candida isolates by the NCCLS microdilution method."n"nMethods: 191 Candida were isolated from vaginal secretions and identified with conventional mycological methods in the diagnosis of Candida species. The identity of all strains was confirmed genotypically by multiplex PCR. In vitro susceptibility testing of vaginal Candida isolates was performed by the NCCLS broth microdilution method. The results were read at 48 h."n"nResults: Most C. albicans isolates (>90% were sensitive in vitro to the antifungal agents tested. Most C. glabrata isolates showed sensitivity to miconazole and then flucytosine while they were more resistant to Itraconazole and fluconazole. Many isolates of C. tropicalis were susceptible to miconazole and then fluconazole. They showed a little resistance to

  13. A case of Candida famata sepsis in a very low birth weight infant successfully treated with fluconazole following antifungal susceptibility testing

    Directory of Open Access Journals (Sweden)

    Shilpee Raturi

    2015-01-01

    This case report highlights the growing number of cases arising due to nonalbicans Candida infections in the neonatal intensive care units and the usefulness of antifungal susceptibility testing in deciding optimal antifungal therapy and preventing the emergence of drug resistance.

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

    NARCIS (Netherlands)

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

    2017-01-01

    BACKGROUND: Antifungal susceptibility testing is a subject of interest in the field of medical mycology. The aim of the present study were the distributions and antifungal susceptibility patterns of various Candida species isolated from colonized and infected immunocompromised patients admitted to

  15. Candidemia: Speciation and Antifungal susceptibility testing from a Tertiary Care Hospital in Maharashtra, India

    Directory of Open Access Journals (Sweden)

    Nageswari Rajesh Gandham

    2016-01-01

    Full Text Available Introduction: Invasive fungal infections are an important nosocomial health problem, candidal infections being the most common. Candidal bloodstream infections (BSIs account for one-fourth of the nosocomial BSIs. Candida albicans once the most common has now been replaced by nonalbicans Candida, accounting for majority of cases of candidal infections. The knowledge and understanding of specific risk factors, epidemiology, prophylactic measures, and outcomes with relation to speciation are changing rapidly. Emergence of antifungal resistance is a cause of concern. With this background, a prospective study was undertaken. Aims and Objectives: To isolate Candida spp. from blood cultures of patients with clinically diagnosed or suspected septicemia; to identify and speciate Candida isolates and carry out the antifungal susceptibility test; to determine incidence of candidemia; to find out the crude mortality rate in candidemia patients. Materials and Methods: Blood cultures received in the Department of Microbiology from various critical care units over a 1-year period were included in this study. Samples were cultured on Sabouraud dextrose agar and routine bacteriological cultures. Speciation of suspected Candida growth was done by conventional and automated system. Results: A total of 225 out of 839 blood cultures were culture positive. A total of 196 were bacterial pathogens. Candida spp. were isolated in 29 samples. These included 10 cases of Candida tropicalis, 8 Candida parapsilosis, and three cases each of C. albicans and Candida krusei. Fluconazole resistance was seen (minimum inhibitory concentration ≥64 μg/ml in 4 isolates, 2 of C. krusei and 2 of Candida haemulonii. Incidence of candidemia was 3.46%. Crude mortality rate in the present study was 24%.

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

    Science.gov (United States)

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

    2017-08-15

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

  17. Development of a 96-well catheter-based microdilution method to test antifungal susceptibility of Candida biofilms.

    Science.gov (United States)

    Nweze, Emeka I; Ghannoum, Adam; Chandra, Jyotsna; Ghannoum, Mahmoud A; Mukherjee, Pranab K

    2012-01-01

    Candida biofilms, which are often associated with device-related infections, including catheter-related bloodstream infections, are resistant to commonly used antifungal agents. Current microtitre (96-well) plate-based methods to determine the antifungal susceptibility of these biofilms do not involve clinically relevant substrates (e.g. catheters), and are not well suited for evaluating the surface topography and three-dimensional architecture of biofilms. We describe a simple, reproducible catheter-based microtitre plate method to form biofilms and evaluate their antifungal susceptibility. Biofilms were formed by Candida species on 5 mm catheter discs placed in microtitre plates and quantified using metabolic conversion of a formazan dye (XTT). The morphology, surface topography and three-dimensional architecture of these biofilms were evaluated by fluorescence, confocal scanning laser and scanning electron microscopy, respectively. The optimized XTT method was used to evaluate the antifungal susceptibility of formed Candida biofilms to fluconazole, voriconazole, itraconazole and anidulafungin. Maximum XTT activity was achieved within 90 min. All tested Candida strains formed robust biofilms on catheter discs at both 24 and 48 h (P = 0.66). Biofilms exhibited typical gross morphology, surface topography and architecture, and no difference in biofilm thickness (P = 0.37). The three tested azoles were not active against the biofilms (MIC ≥ 64 mg/L), but anidulafungin possessed potent activity against them (MIC = 0.063-0.125 mg/L). The developed method is simple, rapid and reproducible, and requires relatively small amounts of drug. It can be used to perform both high-resolution microscopic analysis of the topography and architecture of biofilms, and evaluation of their antifungal susceptibility.

  18. Species identification and antifungal susceptibility pattern of ...

    African Journals Online (AJOL)

    Species identification of Candida isolates was done using phenotypic methods including germ tube test, Rice Tween-80 agar, Chrom ID (CAN2) agar and API 20C AUX, while PCR-RFLP was used as the gold standard method. Antifungal susceptibility testing was done using the disk diffusion method. Results: Vaginal swab ...

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

    NARCIS (Netherlands)

    Furustrand Tafin, U.; Meis, J.F.G.M.; Trampuz, A.

    2012-01-01

    We evaluated isothermal microcalorimetry for real-time susceptibility testing of non-Aspergillus molds. MIC and minimal effective concentration (MEC) values of Mucorales (n = 4), Fusarium spp. (n = 4), and Scedosporium spp. (n = 4) were determined by microbroth dilution according to the Clinical

  20. Antifungal susceptibility testing of vulvovaginal Candida species among women attending antenatal clinic in tertiary care hospitals of Peshawar

    Directory of Open Access Journals (Sweden)

    Khan M

    2018-03-01

    Full Text Available Maria Khan,1 Jawad Ahmed,2 Amina Gul,3 Aamer Ikram,1 Farida Khurram Lalani1 1Department of Microbiology, Armed Forces Institute of Pathology, National University of Management Sciences, CMH Rawalpindi, Rawalpindi, Pakistan; 2Department of Microbiology, Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, Pakistan; 3Department of Microbiology, Khyber Medical College, Khyber Medical University, Peshawar, Pakistan Background: Vulvovaginal candidiasis (VVC is considered as a pervasive gynecological problem among women worldwide. Owing to this fact, in the current study, we aimed at assessing the prevalence rate of Candida spp. causing VVC in symptomatic pregnant women and their antifungal susceptibility pattern. Methods: This study was carried out in the tertiary care hospitals of Peshawar during the period of July 1, 2016 to December 31, 2016. The study group included 450 pregnant women in the age group of 17–44 years with symptoms of excessive vaginal discharge, pain and pruritis. In all, 108 pregnant women were culture positive for Candida. Antimicrobial susceptibility testing (AST was conducted on specimens against various azoles and polyene F group of antifungals. Results: Out of 108 Candida spp. isolated from vaginal swabs, there were 45 (41.7% Candida albicans, 18 (16.7% Candida tropicalis, 18 (16.7% Candida krusei, 16 (14.8% Candida glabrata and 11 (10.2% Candida dubliniensis. According to age distribution, 27 years was the mean age. Pregnancy trimester distribution among patients was as follows: 21 (19.4% patients were in their first trimester, 65 (60.2% patients were in their second trimester and 22 (20.4% patients were in the third trimester. Susceptibility of fluconazole was determined as follows: 33.3% of the Candida isolates were sensitive, 4.6% were susceptible dose dependent (SDD and 62% were resistant. Susceptibility of Candida spp. with respect to nystatin in patients with VVC was as follows: 25% were

  1. Antifungal susceptibility testing of Aspergillus species complex in the Clinical Laboratory: how to do it, when to do it, and how to interpret it

    Directory of Open Access Journals (Sweden)

    Esther Manso

    2014-12-01

    Full Text Available The emergence of drug resistance in fungal pathogens has a profound impact on human health given limited number of antifungal drugs. Antifungal resistance in Aspergillus spp. infection can be encountered in the antifungal drug-exposed patient due to selection of intrinsically resistant species or isolates with acquired resistance belonging to species that are normally susceptible. Resistance to triazoles is not common in Aspergillus spp., however, triazole resistance in A. fumigatus appears to be increasing in several European countries in recent years and can be clinically relevant. The Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing have developed breakpoints and epidemiological cutoff values that are now established for Aspergillus spp. Clinical microbiology laboratories will be employed commercial susceptibility assays, rather than reference broth microdilution methods and comparative studies are particularly important.

  2. The role of epidemiological cutoff values (ECVs/ECOFFs) in antifungal susceptibility testing and interpretation for uncommon yeasts and moulds.

    Science.gov (United States)

    Espinel-Ingroff, Ana; Turnidge, John

    2016-01-01

    The role of antimicrobial susceptibility testing is to aid in selecting the best agent for the treatment of bacterial and fungal diseases. This has been best achieved by the setting of breakpoints by Clinical Laboratory Standards Institute (CLSI) for prevalent Candida spp. versus anidulafungin, caspofungin, micafungin, fluconazole, and voriconazole. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) also has set breakpoints for prevalent and common Candida and Aspergillus species versus amphotericin B, itraconazole, and posaconazole. Recently, another interpretive category, the epidemiological cut off value, could aid in the early identification of strains with acquired resistance mechanisms. CLSI has postulated that epidemiological cut off values may, with due caution, aid physicians in managing mycosis by species where breakpoints are not available. This review provides (1) the criteria and statistical approach to establishing and estimating epidemiological cut off values (ECVs), (2) the role of the epidemiological cut off value in establishing breakpoints, (3) the potential role of epidemiological cut off values in clinical practice, (4) and the wide range of CLSI-based epidemiological cut off values reported in the literature as well as EUCAST and Sensititre Yeast One-ECVs. Additionally, we provide MIC/MEC (minimal inhibitory concentrations/minimum effective concentrations) ranges/modes of each pooled distribution used for epidemiological cut off value calculation. We focus on the epidemiological cut off value, the new interpretive endpoint that will identify the non-wild type strains (defined as potentially harboring resistance mechanisms). However, we emphasize that epidemiological cut off values will not categorize a fungal isolate as susceptible or resistant as breakpoints do, because the former do not account for the pharmacology of the antifungal agent or the findings from clinical outcome studies. Copyright © 2016 Asociación Espa

  3. Antifungal susceptibility testing of Candida in the Clinical Laboratory: how to do it, when to do it, and how to interpret it

    Directory of Open Access Journals (Sweden)

    Esther Manso

    2014-06-01

    Full Text Available Significant changes in the management of fungaemia have occurred in the last decade with increased use of fluconazole prophylaxis, of empirical treatment and of echinocandins as first-line agents for documented disease. The emergence of drug resistance in fungal pathogens has a profound impact on human health given limited number of antifungal drugs. Antifungal resistance in Candida may be either intrinsic or acquired and may be encountered in the antifungal drug exposed but also the antifungal drug naïve patient The variation in resistance rates between centers emphasizes that it is essential to have knowledge of the local Candida species distribution and antifungal resistance rates to guide initial therapy for Candida BSI. Moreover, all Candida isolates from blood and normally sterile sites should be identified to the species level. The Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing have developed breakpoints and epidemiological cutoff values that are now established for Candida spp. Clinical microbiology laboratories will be employed commercial susceptibility assays, rather than reference broth microdilution methods and comparative studies are particularly important. Vitek 2®, Etest® and Sensititre YeastOne® provided a high degree of essential agreement and comparable sensitivity and specificity to BMD-RPMI for identifying resistance to azole and echinocandins in Candida spp.

  4. Comparison of EUCAST and CLSI broth microdilution methods for the susceptibility testing of 10 systemically active antifungal agents when tested against Candida spp.

    Science.gov (United States)

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

    2014-06-01

    The antifungal broth microdilution (BMD) method of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) was compared with Clinical and Laboratory Standards Institute (CLSI) BMD method M27-A3 for amphotericin B, flucytosine, anidulafungin, caspofungin, micafungin, fluconazole, isavuconazole, itraconazole, posaconazole, and voriconazole susceptibility testing of 357 isolates of Candida. The isolates were selected from global surveillance collections to represent both wild-type (WT) and non-WT MIC results for the azoles (12% of fluconazole and voriconazole results were non-WT) and the echinocandins (6% of anidulafungin and micafungin results were non-WT). The study collection included 114 isolates of Candida albicans, 73 of C. glabrata, 76 of C. parapsilosis, 60 of C. tropicalis, and 34 of C. krusei. The overall essential agreement (EA) between EUCAST and CLSI results ranged from 78.9% (posaconazole) to 99.6% (flucytosine). The categorical agreement (CA) between methods and species of Candida was assessed using previously determined CLSI epidemiological cutoff values. The overall CA between methods was 95.0% with 2.5% very major (VM) and major (M) discrepancies. The CA was >93% for all antifungal agents with the exception of caspofungin (84.6%), where 10% of the results were categorized as non-WT by the EUCAST method and WT by the CLSI method. Problem areas with low EA or CA include testing of amphotericin B, anidulafungin, and isavuconazole against C. glabrata, itraconazole, and posaconazole against most species, and caspofungin against C. parapsilosis, C. tropicalis, and C. krusei. We confirm high level EA and CA (>90%) between the 2 methods for testing fluconazole, voriconazole, and micafungin against all 5 species. The results indicate that the EUCAST and CLSI methods produce comparable results for testing the systemically active antifungal agents against the 5 most common species of Candida; however, there are several areas where additional

  5. Antifungal susceptibility testing of yeast isolated from corneal infections Teste de susceptibilidade a antifúngicos de leveduras isoladas de infecções corneais

    Directory of Open Access Journals (Sweden)

    Vera Lucia Degaspare Monte Mascaro

    2003-10-01

    Full Text Available PURPOSE: To report the antifungal susceptibility profile of yeast isolates obtained from cases of keratitis. METHODS: Susceptibility testing of 15 yeast strains isolated from corneal infections to amphotericin B, fluconazole, itraconazole and ketoconazole was performed using the NCCLS broth microdilution assay. RESULTS: Most episodes of eye infections were caused by Candida albicans. The antifungal drugs tested showed the following minimal inhibitory concentration values against yeast isolates: 0.125-0.5 µg/ml for amphotericin B; 0.125->64.0 µg/ml for fluconazole; 0.015-1.0 µg/ml for itraconazole and 0.015-0.125 µg/ml for ketoconazole. Despite the fact that all Candida isolates were judged to be susceptible to azoles, one isolate showed a minimal inhibitory concentration value significantly higher than a 90% minimal inhibitory concentration of all tested isolates. Rhodotorula rubra was resistant to fluconazole and itraconazole. CONCLUSIONS: Despite the fact that most yeast isolates from corneal infections are usually susceptible to amphotericin B and azoles, they exhibit a wide range of minimal inhibitory concentration values for antifungal drugs. The identification of strains at species level and their susceptibility pattern to antifungal drugs should be considered before determining the concentration to be used in topical antifungal formulations in order to optimize therapeutic response in eye infections.OBJETIVO: Relatar resultados e avaliar a aplicabilidade do teste de suscetibilidade a antifúngicos de leveduras isoladas de infecções corneais oculares. MÉTODOS: Realizou-se teste de suscetibilidade pelo método de microdiluição em caldo, padronizado pelo NCCLS-EUA, em 15 amostras de leveduras de infecções corneanas a anfotericina B, fluconazol, itraconazol e ketoconazol. RESULTADOS: A maioria dos episódios de infecção corneal foi causada por Candida albicans. As drogas antifúngicas testadas exibiram valores de concentra

  6. Prevalence and Antifungal Susceptibility of Candida Species ...

    African Journals Online (AJOL)

    Candidal vulvovaginitis causes extreme discomfort and affects the well being of women. The aim of this study was to determine the prevalence of Candida infections among women attending gynaecological clinic at the Komfo Anokye Teaching Hospital (KATH) in Kumasi and the antifungal susceptibility patterns of the ...

  7. Molecular identification and in-vitro antifungal susceptibility testing of Candida species isolated from patients with onychomycosis

    Directory of Open Access Journals (Sweden)

    Keyvan Pakshir

    2015-03-01

    Full Text Available Background and Purpose: Candida species are the most opportunistic fungi affecting the nails and resulting in onychomycosis. In this study, we identified and evaluated in-vitro susceptibility of the recovered isolates against fluconazole (FLC, voriconazole (VRC, and clotrimazole (CLT using the Clinical and Laboratory Standards Institute (CLSI M27-A3 document. Materials and Methods: From patients with either clinically or mycologically proven onychomycosis, 97 isolates comprising of seven Candida species were isolated, which were identified by both conventional and molecular techniques such as polymerase chain reaction-restriction fragment length polymorphism. In addition, Candida dubliniensis was confirmed by restriction endonuclease analysis. Antifungal susceptibility of each isolate against the three azoles applied in this study was determined using the CLSI microdilution reference method M27-A3. Results: Candida parapsilosis (C. parapsilosis was the most frequently isolated species (n=44, followed by C. albicans (n=23, C. tropicalis (n=13, C. glabrata (n=7, C. krusei (n=6, C. guilliermondii (n=3, and C. dubliniensis (n=1. All the isolates were susceptible to CLT. VRC had lower minimum inhibitory concentration (MIC values for the isolates compared to FLC. Geometric mean MIC values of VRC, FLC, and CLT for C. parapsilosis isolates were 0.07 µg/ml, 0.8 µg/ml, and 0.35 µg/ml, respectively. Collectively, all species exhibited greater susceptibility to VRC in comparison to C. albicans (P≤0.001. Conclusion: This study showed that non-albicans Candida species were the most common etiologic agents of non-dermatophyte onychomycosis. The major antifungal agents used in clinics to empirically treat yeast onychomycosis are FLC and CLT. Our data suggested that CLT is a better choice for the treatment of Candida onychomycosis, especially in drug resistant cases.

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

    Directory of Open Access Journals (Sweden)

    Parisa Badiee

    2017-11-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2017-11-21

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

  11. Taxonomy and antifungal susceptibility of clinically important Rasamsonia species

    DEFF Research Database (Denmark)

    Houbraken, J.; Giraud, S.; Meijer, M.

    2013-01-01

    In recent years, Geosmithia argillacea has been increasingly reported in humans and animals and can be considered an emerging pathogen. The taxonomy of Geosmithia was recently studied, and Geosmithia argillacea and related species were transferred to the new genus Rasamsonia. The diversity among...... the presence of four species in the Rasamsonia argillacea complex, two of which are newly described here: R. piperina sp. nov. and R. aegroticola sp. nov. In contrast to other related genera, all Rasamsonia species can be identified with ITS sequences. A retrospective identification was performed on recently...... was the least active of the antifungals tested. The phenotypically similar species R. brevistipitata and R. cylindrospora had different antifungal susceptibility profiles, and this indicates that correct species identification is important to help guide appropriate antifungal therapy....

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

    Science.gov (United States)

    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. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Comparative evaluation of three antifungal susceptibility test methods for Candida albicans isolates and correlation with response to fluconazole therapy.

    OpenAIRE

    Ruhnke, M; Schmidt-Westhausen, A; Engelmann, E; Trautmann, M

    1996-01-01

    In vitro susceptibilities were determined for 56 Candida albicans isolates obtained from the oral cavities of 41 patients with human immunodeficiency virus infection. The agents tested included fluconazole, itraconazole, ketoconazole, flucytosine, and amphotericin B. MICs were determined by the broth microdilution technique following National Committee for Clinical Laboratory Standards document M27-P (M27-P micro), a broth microdilution technique using high-resolution medium (HR micro), and t...

  14. [A study for testing the antifungal susceptibility of yeast by the Japanese Society for Medical Mycology (JSMM) method. The proposal of the modified JSMM method 2009].

    Science.gov (United States)

    Nishiyama, Yayoi; Abe, Michiko; Ikeda, Reiko; Uno, Jun; Oguri, Toyoko; Shibuya, Kazutoshi; Maesaki, Shigefumi; Mohri, Shinobu; Yamada, Tsuyoshi; Ishibashi, Hiroko; Hasumi, Yayoi; Abe, Shigeru

    2010-01-01

    The Japanese Society for Medical Mycology (JSMM) method used for testing the antifungal susceptibility of yeast, the MIC end point for azole antifungal agents, is currently set at IC(80). It was recently shown, however that there is an inconsistency in the MIC value between the JSMM method and the CLSI M27-A2 (CLSI) method, in which the end- point was to read as IC(50). To resolve this discrepancy and reassess the JSMM method, the MIC for three azoles, fluconazole, itraconazole and voriconazole were compared to 5 strains of each of the following Candida species: C. albicans, C. glabrata, C. tropicalis, C. parapsilosis and C. krusei, for a total of 25 comparisons, using the JSMM method, a modified JSMM method, and the CLSI method. The results showed that when the MIC end- point criterion of the JSMM method was changed from IC(80) to IC(50) (the modified JSMM method) , the MIC value was consistent and compatible with the CLSI method. Finally, it should be emphasized that the JSMM method, using a spectrophotometer for MIC measurement, was superior in both stability and reproducibility, as compared to the CLSI method in which growth was assessed by visual observation.

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

    NARCIS (Netherlands)

    Vitale, R.G.; de Hoog, G.S.; Schwarz, P.; Dannaoui, E.; Deng, S.; Machouart, M.; Voigt, K.; de Sande, W.W.J.v.; Dolatabadi, S.; Meis, J.F.; Walther, G.

    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

  16. Antifungal susceptibility and phylogeny of opportunistic members of the order Mucorales

    NARCIS (Netherlands)

    R.G. Vitale (Roxana); G.S. de Hoog; P. Schwarz (Peter); E. Dannaoui (Eric); S. Deng (Shuwen); M. Machouart (Marie); K. Voigt (Kerstin); W.W.J. van de Sande (Wendy); S. Dolatabadi (Somayeh); J.F. Meis; G. Walther

    2012-01-01

    textabstractThe 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

  17. Antifungal susceptibility and phylogeny of opportunistic members of the order mucorales.

    NARCIS (Netherlands)

    Vitale, R.G.; Hoog, G.S. de; Schwarz, P.; Dannaoui, E.; Deng, S.; Machouart, M.; Voigt, K.; Sande, W.W. van de; Dolatabadi, S.; Meis, J.F.G.M.; Walther, G.

    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

  18. Antifungal susceptibility of bloodstream Candida isolates in Sfax hospital: Tunisia.

    Science.gov (United States)

    Sellami, A; Sellami, H; Néji, S; Makni, F; Abbes, S; Cheikhrouhou, F; Chelly, H; Bouaziz, M; Hammami, B; Ben Jemaa, M; Khaled, S; Ayadi, A

    2011-06-01

    Invasive candidiasis has emerged as an important nosocomial infection, causing significant morbidity and mortality especially among critically ill patients. The aim of our study was to determine specie distribution and resistance profiles of Candida species isolated from blood cultures. We conducted a retrospective study of all episodes of candidemia diagnosed in our laboratory from January 2006 to May 2009. The susceptibility to antifungal agents of all Candida isolates was tested by using a Sensititre(®) YeastOne panel. A total of 130 Candida isolates were recovered from blood cultures. Candida tropicalis was the most frequent specie (37.7%), followed by C. albicans (22.3%), C. glabrata (19.2%), and C. parapsilosis (12.2%). All the isolates were inhibited by ≤1 μg/ml of amphotericin B and ≤2 μg/ml of caspofungin. For fluconazole, 7.3% of clinical isolates were resistant. It was most active against C. parapsilosis (100% susceptible), C. albicans (95.8% susceptible), and C. tropicalis (94% susceptible). All of the fluconazole-susceptible isolates were susceptible to voriconazole, as were 83.3% of the fluconazole-susceptible-dose-dependent isolates. Among fluconazole-resistant isolates, 85.7% were susceptible to voriconazole. In our institution, C. tropicalis was the most frequent specie isolated from the bloodstream. Caspofungin had an excellent in vitro activity against Candida isolates and was the drug of choice among fluconazole-resistant isolates. © Springer Science+Business Media B.V. 2010

  19. Evaluation of Etest and macrodilution broth method for antifungal susceptibility testing of Candida sp strains isolated from oral cavities of AIDS patients

    Directory of Open Access Journals (Sweden)

    SILVA Maria do Rosário R.

    2002-01-01

    Full Text Available A comparison of the Etest and the reference broth macrodilution susceptibility test for fluconazole, ketoconazole, itraconazole and amphotericin B was performed with 59 of Candida species isolated from the oral cavities of AIDS patients. The Etest method was performed according to the manufacturer's instructions, and the reference method was performed according to National Committee for Clinical Laboratory Standards document M27-A guidelines. Our data showed that there was a good correlation between the MICs obtained by the Etest and broth dilution methods. When only the MIC results at ± 2 dilutions for both methods were considered, the agreement rates were 90.4% for itraconazole, ketoconazole and amphotericin B and 84.6% for fluconazole of the C. albicans tested. In contrast, to the reference method, the Etest method classified as susceptible three fluconazole-resistant isolates and one itraconazole-resistant isolate, representing four very major errors. These results indicate that Etest could be considered useful for antifungal sensitivity evaluation of yeasts in clinical laboratories.

  20. Comparative evaluation of three antifungal susceptibility test methods for Candida albicans isolates and correlation with response to fluconazole therapy.

    Science.gov (United States)

    Ruhnke, M; Schmidt-Westhausen, A; Engelmann, E; Trautmann, M

    1996-01-01

    In vitro susceptibilities were determined for 56 Candida albicans isolates obtained from the oral cavities of 41 patients with human immunodeficiency virus infection. The agents tested included fluconazole, itraconazole, ketoconazole, flucytosine, and amphotericin B. MICs were determined by the broth microdilution technique following National Committee for Clinical Laboratory Standards document M27-P (M27-P micro), a broth microdilution technique using high-resolution medium (HR micro), and the Etest with solidified yeast-nitrogen base agar. The in vitro findings were correlated with in vivo response to fluconazole therapy for oropharyngeal candidiasis. For all C. albicans isolates from patients with oropharyngeal candidiasis not responding to fluconazole MICs were found to be > or = 6.25 micrograms/ml by the M27-P micro method and > or = 25 micrograms/ml by the HR micro method as well as the Etest. However, for several C. albicans isolates from patients who responded to fluconazole therapy MICs found to be above the suggested breakpoints of resistance. The appropriate rank order of best agreement between the M27-P micro method and HR micro method was amphotericin B > fluconazole > flucytosine > ketoconazole > itraconazole. The appropriate rank order with best agreement between the M27-P micro method and the Etest was flucytosine > amphotericin B > fluconazole > ketoconazole > or = itraconazole. It could be concluded that a good correlation between in vitro resistance and clinical failure was found with all methods. However, the test methods used in this study did not necessarily predict clinical response to therapy with fluconazole. PMID:8940474

  1. In vitro antifungal susceptibility of Malassezia furfur from bloodstream infections.

    Science.gov (United States)

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

    2014-11-01

    Fungaemia caused by Malassezia spp. in hospitalized patients requires prompt and appropriate therapy, but standard methods for the definition of the in vitro antifungal susceptibility have not been established yet. In this study, the in vitro susceptibility of Malassezia furfur from bloodstream infections (BSIs) to amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), posaconazole (POS) and voriconazole (VRC) was assessed using the broth microdilution (BMD) method of the Clinical and Laboratory Standards Institute (CLSI) with different media such as modified Sabouraud dextrose broth (SDB), RPMI and Christensen's urea broth (CUB). Optimal broth media that allow sufficient growth of M. furfur, and produce reliable and reproducible MICs using the CLSI BMD protocol were assessed. Thirty-six M. furfur isolates collected from BSIs of patients before and during AMB therapy, and receiving FLC prophylaxis, were tested. A good growth of M. furfur was observed in RPMI, CUB and SDB at 32 °C for 48 and 72 h. No statistically significant differences were detected between the MIC values registered after 48 and 72 h incubation. ITC, POS and VRC displayed lower MICs than FLC and AMB. These last two antifungal drugs showed higher and lower MICs, respectively, when the isolates were tested in SDB. SDB is the only medium in which it is possible to detect isolates with high FLC MICs in patients receiving FLC prophylaxis. A large number of isolates showed high AMB MIC values regardless of the media used. In conclusion, SDB might be suitable to determine triazole susceptibility. However, the media, the drug formulation or the breakpoints herein applied might not be useful for assessing the AMB susceptibility of M. furfur from BSIs. © 2014 The Authors.

  2. Antifungal susceptibility profiles of 1698 yeast reference strains revealing potential emerging human pathogens.

    Directory of Open Access Journals (Sweden)

    Marie Desnos-Ollivier

    Full Text Available New molecular identification techniques and the increased number of patients with various immune defects or underlying conditions lead to the emergence and/or the description of novel species of human and animal fungal opportunistic pathogens. Antifungal susceptibility provides important information for ecological, epidemiological and therapeutic issues. The aim of this study was to assess the potential risk of the various species based on their antifungal drug resistance, keeping in mind the methodological limitations. Antifungal susceptibility profiles to the five classes of antifungal drugs (polyens, azoles, echinocandins, allylamines and antimetabolites were determined for 1698 yeast reference strains belonging to 992 species (634 Ascomycetes and 358 Basidiomycetes. Interestingly, geometric mean minimum inhibitory concentrations (MICs of all antifungal drugs tested were significantly higher for Basidiomycetes compared to Ascomycetes (p<0.001. Twenty four strains belonging to 23 species of which 19 were Basidiomycetes seem to be intrinsically "resistant" to all drugs. Comparison of the antifungal susceptibility profiles of the 4240 clinical isolates and the 315 reference strains belonging to 53 shared species showed similar results. Even in the absence of demonstrated in vitro/in vivo correlation, knowing the in vitro susceptibility to systemic antifungal agents and the putative intrinsic resistance of yeast species present in the environment is important because they could become opportunistic pathogens.

  3. Species identification and antifungal susceptibility pattern of ...

    African Journals Online (AJOL)

    Dalia Saad ElFeky

    2015-10-23

    Oct 23, 2015 ... Abstract Vulvovaginal candidiasis (VVC) remains one of the most common infections of the female genital tract. Correct identification of the isolated Candida species is essential to direct the empirical antifungal therapy. Objectives: This local study was conducted to identify the spectrum of Candida species ...

  4. Susceptibility Testing

    Science.gov (United States)

    ... Gene Mutations Testing Cytomegalovirus (CMV) Tests D-dimer Dengue Fever Testing Des-gamma-carboxy prothrombin (DCP) DHEAS ... can develop resistance to the drugs used to treat them, but that type of testing is performed ...

  5. Antifungal drug susceptibility of Candida albicans | Bii | East African ...

    African Journals Online (AJOL)

    Objective: To determine the susceptibility of clinical isolates of Candida albicans and to establish the minimum inhibitory concentrations (MIC) to commonly used antifungal drugs. Design: Laboratory based experiment. Setting: Mbagathi District Hospital, Nairobi, Kenya. Subjects: Candida albicans isolated between 1998 ...

  6. prevalence and antifungal susceptibility of candida species isolated ...

    African Journals Online (AJOL)

    User

    Nucleo, E., Zara, F. and Pagani, L. (2009). "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." New. Mi- crobiol., 32(2): 199-204. Araj, G. F., Daher, N. K. and Tabborah, ...

  7. Antifungal susceptibility profiles and risk factors of vaginal ...

    African Journals Online (AJOL)

    Antifungal susceptibility results showed a high resistance to fluconazole (82.0%), nystatin (80.0%) and ketoconazole (72.0%), while clotrimazole (50.0%) was the most activeantifungal drug. There was a high prevalence of VC in this study population with previous vaginal infectionbeing important risk factor for reoccurrence.

  8. Determination of antifungal susceptibility patterns among the clinical isolates of Candida species

    Directory of Open Access Journals (Sweden)

    Kamiar Zomorodian

    2011-01-01

    Full Text Available Context: Candida species are opportunistic yeasts that cause infections ranging from simple dermatosis to potentially life-threatening fungemia. The emergence of resistance to antifungal drugs has been increased in the past two decades. Aim: the present study we determined to find out the susceptibility profiles of clinical isolates of Candida species against four antifungal drugs, including amphotericin B, ketoconazole, fluconazole and itraconazole. Materials and Methods: Antifungal susceptibility testing of the yeasts was done in accordance with the proposed guidelines for antifungal disk diffusion susceptibility testing of yeasts based on the CLSI document M44-A. Results: A total of 206 yeast isolates were assessed. Among the evaluated Candida species, the highest rates of resistance to ketoconazole were seen in Candida glabrata (16.6% and Candida albicans (3.2%. Susceptibility and intermediate response to fluconazole were seen in 96.6% and 3.4% of the Candida isolates, respectively. A total of 19 (9.2% yeast isolates showed petite phenomenon including 11 C. glabrata, 3 C. albicans, 2 Candida dubliniensis and one isolate of each Candida krusei and Candida parapsilosis. Conclusion: The high number of petite mutation in the isolated yeasts should be seriously considered since it may be one of the reasons of antifungal treatment failure.

  9. Antimycotics susceptibility testing of dermatophytes

    Directory of Open Access Journals (Sweden)

    Arsić-Arsenijević Valentina

    2010-01-01

    Full Text Available Dermatophytes are moulds that produce infections of the skin, hair and nails of humans and animals. The most common forms among these infections are onychomycosis and tinea pedis affecting 20% of world population. These infections are usually chronic. The treatment of dermatophytoses tends to be prolonged partly because available treatments are not very effective. Antifungal drug consumption and public health expenditure are high worldwide, as well as in Serbia. For adequate therapy, it is necessary to prove infection by isolation of dermatophytes and to test the antifungal susceptibility of isolates. Susceptibility testing is important for the resistance monitoring, epidemiological research and to compare in vitro activities of new antifungal agents. The diffusion and dilution methods of susceptibility tests are used, and technical issues of importance for the proper performance and interpretation of test results are published in the document E.DEF 9.1 (EUCAST and M38-A2 (CLSI. The aim of our paper is to promptly inform the public about technical achievements in this area, as well as the new organization of laboratory for medical mycology in our country. The formation of laboratory networks coordinated by the National Reference Laboratory for the cause of mycosis need to enable interlaboratory studies and further standardization of methods for antifungal susceptibility testing of dermatophytes, reproducibility of tests and clinical correlation monitoring (MIK values and clinical outcome of dermatophytosis. The importance of the new organization is expected efficient improvement in the dermatophytosis therapy at home, better quality of patient's life and the reduction of the cost of treatment.

  10. Isolation of Candida Species from Gastroesophageal Lesions among Pediatrics in Isfahan, Iran: Identification and Antifungal Susceptibility Testing of Clinical Isolates by E-test

    Directory of Open Access Journals (Sweden)

    Fatemeh Salehi

    2017-01-01

    Full Text Available Background: Candida species can become opportunistic pathogens causing local or systemic invasive infections. Gastroesophageal candidiasis may depend on the Candida colonization and local damage of the mucosal barrier. Risk factors are gastric acid suppression, diabetes mellitus, chronic debilitating states such as carcinomas, and the use of systemic antibiotics and corticosteroids. The aim of this study is collection and molecular identification of Candida species from gastroesophageal lesions among pediatrics in Isfahan, and determination of minimum inhibitory concentration (MIC ranges for clinical isolates. Materials and Methods: A total of 200 patients underwent endoscopy (130 specimens from gastritis and 70 samples from esophagitis were included in this study between April 2015 and November 2015. All specimens were subcultured on sabouraud dextrose agar, and genomic DNA of all strains was extracted using boiling method. Polymerase chain reaction and DNA sequencing of the ITS1-5.8SrDNA-ITS2 region were used for the identification of all Candida strains. MIC ranges were determined for itraconazole (ITC, amphotericin B (AmB, and fluconazole (FLU by E-test. Results: Twenty of 200 suspected patients (10% were positive by direct microscopy and culture. Candida albicans was the most common species (60% followed by Candida glabrata (30%, Candida parapsilosis (5%, and Candida kefyr (5%. MIC ranges were determined for FLU (0.125–8 μg/mL, ITC (0.008–0.75 μg/mL, and AmB (0.008–0.75 μg/mL, respectively. Conclusion: Every colonization of Candida species should be considered as a potentially factor of mucocutaneous candidiasis and should be treated with antifungal drugs.

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

    Science.gov (United States)

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

    2017-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Partha Pratim Das

    2016-01-01

    Results: From the 59 culture positive HIV seropositive cases, 61 Candida isolates were recovered; Candidaalbicans (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.

  13. Antifungal susceptibility of invasive yeast isolates in Italy: the GISIA3 study in critically ill patients

    Directory of Open Access Journals (Sweden)

    Mussap Michele

    2011-05-01

    Full Text Available Abstract Background Yeasts are a common cause of invasive fungal infections in critically ill patients. Antifungal susceptibility testing results of clinically significant fungal strains are of interest to physicians, enabling them to adopt appropriate strategies for empiric and prophylactic therapies. We investigated the antifungal susceptibility of yeasts isolated over a 2-year period from hospitalised patients with invasive yeast infections. Methods 638 yeasts were isolated from the blood, central venous catheters and sterile fluids of 578 patients on general and surgical intensive care units and surgical wards. Etest strips and Sensititre panels were used to test the susceptibility of the isolates to amphotericin B, anidulafungin, caspofungin, fluconazole, itraconazole, posaconazole and voriconazole in 13 laboratories centres (LC and two co-ordinating centres (CC. The Clinical and Laboratory Standards Institute (CLSI reference broth microdilution method was used at the CCs for comparison. Results Etest and Sensititre (LC/CC MIC90 values were, respectively: amphotericin B 0.5/0.38, 1/1 mg/L; anidulafungin 2/1.5 and 1/1 mg/L; caspofungin 1/0.75 and 0.5/0.5 mg/L; fluconazole 12/8 and 16/16 mg/L; itraconazole 1/1.5, 0.5/0.5 mg/L; posaconazole 0.5 mg/L and voriconazole 0.25 mg/L for all. The overall MIC90 values were influenced by the reduced susceptibility of Candida parapsilosis isolates to echinocandins and a reduced or lack of susceptibility of Candida glabrata and Candida krusei to azoles, in particular fluconazole and itraconazole. Comparison of the LC and CC results showed good Essential Agreement (90.3% for Etest and 92.9% for Sensititre, and even higher Categorical Agreement (93.9% for Etest and 96% for Sensititre; differences were observed according to the species, method, and antifungal drug. No cross-resistance between echinocandins and triazoles was detected. Conclusions Our data confirm the different antifungal susceptibility

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

    Science.gov (United States)

    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.

  15. In Vitro Antifungal Susceptibility of Oral Candida Isolates from Patients Suffering from Caries and Chronic Periodontitis.

    Science.gov (United States)

    De-la-Torre, Janire; Ortiz-Samperio, María Esther; Marcos-Arias, Cristina; Marichalar-Mendia, Xabier; Eraso, Elena; Echebarria-Goicouria, María Ángeles; Aguirre-Urizar, José Manuel; Quindós, Guillermo

    2017-06-01

    Caries and chronic periodontitis are common oral diseases where a higher Candida colonization is reported. Antifungal agents could be adjuvant drugs for the therapy of both clinical conditions. The aim of the current study has been to evaluate the in vitro activities of conventional and new antifungal drugs against oral Candida isolates from patients suffering from caries and/or chronic periodontitis. In vitro activities of amphotericin B, fluconazole, itraconazole, miconazole, nystatin, posaconazole and voriconazole against 126 oral Candida isolates (75 Candida albicans, 18 Candida parapsilosis, 11 Candida dubliniensis, six Candida guilliermondii, five Candida lipolytica, five Candida glabrata, four Candida tropicalis and two Candida krusei) from 61 patients were tested by the CLSI M27-A3 method. Most antifungal drugs were highly active, and resistance was observed in less than 5% of tested isolates. Miconazole was the most active antifungal drug, being more than 98% of isolates susceptible. Fluconazole, itraconazole, and the new triazoles, posaconazole and voriconazole, were also very active. Miconazole, fluconazole and voriconazole have excellent in vitro activities against all Candida isolates and could represent suitable treatment for a hypothetically adjunctive therapy of caries and chronic periodontitis.

  16. Antifungal susceptibility patterns of yeasts and filamentous fungi isolated from nail infection.

    Science.gov (United States)

    Ataides, F S; Chaul, M H; El Essal, F E; Costa, C R; Souza, L K H; Fernandes, O F L; Silva, M R R

    2012-12-01

    Onychomycosis is the nail infection caused by a wide spectrum of fungi species, including yeasts, dermatophytes and filamentous fungi non-dermatophytes (FFND). This fungal infection represents an important medical problem because it involves the patient's life quality. The aim was to isolate and identify the fungal agents of onychomycosis, and to determine the in vitro susceptibility to antifungal agents. During the period of March 2008 to March 2009, 114 patients clinically suspected of having onychomycosis were examined. Demographic data, mainly age and gender were obtained from each patient. The nail samples collected (136) were submitted to direct examination with potassium hydroxide 20% and grown on Sabouraud dextrose agar. The in vitro antifungal susceptibility testing was performed according to the method of broth microdilution, recommended by the Clinical Laboratory Standards Institute (CLSI). Onychomycosis was observed in 95 (83.3%) patients, including 16 men (16.8%) and 79 women (83.2%), with mean age of 48.1 years. Candida parapsilosis, Trichophyton rubrum and Fusarium spp were the fungi most frequently isolated. The most of the isolated yeasts showed susceptibility to antifungal agents studied. Among filamentous fungi, high MIC values to itraconazole were found for T. rubrum and T. mentagrophytes, while Fusarium spp showed decreased susceptibility to itraconazole and voriconazole. C. parapsilosis was the most common fungal species isolated from patients with onychomycosis. The different response obtained by in vitro susceptibility testing to drugs shows the importance of these methods to assist clinicians in choosing the best therapeutic option. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

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

    International Nuclear Information System (INIS)

    Neuhof, Torsten; Seibold, Michael; Thewes, Sascha; Laue, Michael; Han, Chang-Ok; Hube, Bernhard; Doehren, Hans von

    2006-01-01

    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 μg/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

  18. Reduced Antifungal Susceptibility of Vulvovaginal Candida Species at Normal Vaginal pH Levels: Clinical Implications.

    Science.gov (United States)

    Spitzer, Mark; Wiederhold, Nathan P

    2018-02-28

    The aims of the study were to assess for differences in antifungal in vitro potency at pH 7 and pH 4 and to discuss any potential clinical implications of that difference. A retrospective analysis of 217 first positive yeast cultures from 217 patients. Yeast isolates underwent antifungal susceptibility testing, with minimum inhibitory concentrations (MICs) (microgram per milliliter) measured at pH 7 and pH 4 for fluconazole, itraconazole, miconazole, clotrimazole, terconazole, and nystatin. Only the first isolates collected from each patient were included in the analysis. Yeast first isolates included 173 Candida albicans, 15 Candida glabrata, and 29 isolates from 8 other species. Geometric mean (GM) MIC values for all antifungals were significantly higher when tested at pH 4 (p pH 7 vs 6.17 pH 4) and clotrimazole (0.04 vs 0.24). For terconazole, 97.7% of the isolates had a MIC of 1 or less at pH 7 but 83.2% had a MIC of 4 or higher at pH 4. For C. glabrata, terconazole (GM MIC = 0.26 pH 7 vs >64 pH 4), clotrimazole (0.13 vs 6.96), miconazole (0.06 vs 0.76), and fluconazole (3.17 vs 26.6) were most affected. All C. glabrata isolates had a MIC of 1 or less for terconazole at pH 7 and one had a MIC of 8 at pH 4, whereas all the rest were highly resistant (MIC > 64). Antifungals have reduced in vitro potency when tested at lower pH. Candida glabrata is more affected than C. albicans. The impact may be greatest for the antifungal terconazole and against C. glabrata isolates.

  19. Cotrimoxazole enhances the in vitro susceptibility of Coccidioides posadasii to antifungals

    Directory of Open Access Journals (Sweden)

    Rossana de Aguiar Cordeiro

    2011-12-01

    Full Text Available The aim of the present study was to evaluate the effect of cotrimoxazole on the in vitro susceptibility of Coccidioides posadasii strains to antifungals. A total of 18 strains of C. posadasii isolated in Brazil were evaluated in this study. The assays were performed in accordance with the Clinical and Laboratory Standards Institute guidelines and the combinations were tested using the checkerboard method. The minimum inhibitory concentrations were reduced by 11, 2.4, 4.3 and 3.5 times for amphotericin B, itraconazole, fluconazole and voriconazole, respectively. Moreover, it was seen that cotrimoxazole itself inhibited C. posadasii strains in vitro. The impairment of folic acid synthesis may be a potential antifungal target for C. posadasii.

  20. Cotrimoxazole enhances the in vitro susceptibility of Coccidioides posadasii to antifungals.

    Science.gov (United States)

    Cordeiro, Rossana de Aguiar; Astete-Medrano, Delia Jessica; Marques, Francisca Jakelyne de Farias; Andrade, Heuziwanne Tavares Leite; Perdigão Neto, Lauro Vieira; Tavares, Juliane Lira; de Lima, Rita Amanda Chaves; Patoilo, Kharla Kharolyni Nobre Rabelo; Monteiro, Andre Jalles; Brilhante, Raimunda Sâmia Nogueira; Rocha, Marcos Fábio Gadelha; de Camargo, Zoilo Pires; Sidrim, José Júlio Costa

    2011-12-01

    The aim of the present study was to evaluate the effect of cotrimoxazole on the in vitro susceptibility of Coccidioides posadasii strains to antifungals. A total of 18 strains of C. posadasii isolated in Brazil were evaluated in this study. The assays were performed in accordance with the Clinical and Laboratory Standards Institute guidelines and the combinations were tested using the checkerboard method. The minimum inhibitory concentrations were reduced by 11, 2.4, 4.3 and 3.5 times for amphotericin B, itraconazole, fluconazole and voriconazole, respectively. Moreover, it was seen that cotrimoxazole itself inhibited C. posadasii strains in vitro. The impairment of folic acid synthesis may be a potential antifungal target for C. posadasii.

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

    NARCIS (Netherlands)

    Cunha, da K.C.; Sutton, D.A.; Fothergill, A.W.; Gené, J.; Cano, J.; Madrid, H.; Hoog, de G.S.; Crous, P.W.; Guarro, J.

    2013-01-01

    The in vitro antifungal susceptibility of a set of 99 clinical isolates of Curvularia was tested against 9 drugs using a reference microdilution method. The isolates had been identified previously to species level by comparing their ITS rDNA and glyceraldehyde-3-phosphate dehydrogenase gene

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

    Science.gov (United States)

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

    2014-06-01

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

  3. In vitro antifungal susceptibility of clinical species belonging to Aspergillus genus and Rhizopus oryzae.

    Science.gov (United States)

    Kachuei, R; Khodavaisy, S; Rezaie, S; Sharifynia, S

    2016-03-01

    Among filamentous fungal pathogens, Aspergillus spp. and zygomycetes account for highest rates of morbidity and mortality among immunocompromised patients. Recently developed antifungal drugs offer the potential to improve management and therapeutic outcomes of fungal infections. The aim of this study was to analyse the in vitro activities of voriconazole, itraconazole, amphotericin B and caspofungin against clinical isolates of Aspergillus spp. and Rhizopus oryzae. The in vitro antifungal susceptibility of 54 isolates belonging to different clinical isolates of Aspergillus spp. and R. oryzae was tested for four antifungal agents using a microdilution reference method (CLSI, M38-A2). All isolates were identified by typical colony and microscopic characteristics, and also characterized by molecular methods. Caspofungin (MEC range: 0.008-0.25 and MEC50: 0.0023μg/mL) was the most active drug in vitro against Aspergillus spp., followed by voriconazole (MIC range: 0.031-8 and MIC50: 0.5μg/mL), itraconazole (MIC range: 0.031-16 and MIC50: 0.25μg/mL), and amphotericin B (MIC range: 0.125-4 and MIC50: 0.5μg/mL), in order of decreasing activity. The caspofungin, voriconazole, and itraconazole demonstrated poor in vitro activity against R. oryzae isolates evaluated, followed by amphotericin B. This study demonstrates that caspofungin had good antifungal activity and azole agents had better activity than amphotericin B against Aspergillus species. Although, azole drugs are considered ineffective against R. oryzae. This result is just from a small scale in vitro susceptibility study and we did not take other factors into consideration. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. Epidemiology and antifungal susceptibility of Candida species in a tertiary care hospital, Kolkata, India

    Directory of Open Access Journals (Sweden)

    Partha Bhattacharjee

    2016-06-01

    Conclusion: Species-level identification of Candida and their antifungal sensitivity testing should to be performed to achieve better clinical result and to select an appropriate and effective antifungal therapy. High resistance to antifungal agents is an alarming sign to the healthcare professionals.

  5. Cotrimoxazole enhances the in vitro susceptibility of Coccidioides posadasii to antifungals

    OpenAIRE

    Cordeiro,Rossana de Aguiar; Astete-Medrano,Delia Jessica; Marques,Francisca Jakelyne de Farias; Andrade,Heuziwanne Tavares Leite; Perdigão Neto,Lauro Vieira; Tavares,Juliane Lira; Lima,Rita Amanda Chaves de; Patoilo,Kharla Kharolyni Nobre Rabelo; Monteiro,Andre Jalles; Brilhante,Raimunda Sâmia Nogueira; Rocha,Marcos Fábio Gadelha; Camargo,Zoilo Pires de; Sidrim,José Júlio Costa

    2011-01-01

    The aim of the present study was to evaluate the effect of cotrimoxazole on the in vitro susceptibility of Coccidioides posadasii strains to antifungals. A total of 18 strains of C. posadasii isolated in Brazil were evaluated in this study. The assays were performed in accordance with the Clinical and Laboratory Standards Institute guidelines and the combinations were tested using the checkerboard method. The minimum inhibitory concentrations were reduced by 11, 2.4, 4.3 and 3.5 times for amp...

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

    Science.gov (United States)

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

    2016-11-01

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

  7. Species identification and antifungal susceptibility pattern of Candida isolates in cases of vulvovaginal

    Directory of Open Access Journals (Sweden)

    Dalia Saad ElFeky

    2016-09-01

    Full Text Available Vulvovaginal candidiasis (VVC remains one of the most common infections of the female genital tract. Correct identification of the isolated Candida species is essential to direct the empirical antifungal therapy. Objectives: This local study was conducted to identify the spectrum of Candida species associated with VVC using different phenotypic and genotypic methods and assess their antifungal susceptibility pattern. Materials and methods: High vaginal swabs were collected from 125 patients presenting with a clinical picture suggestive of VVC. Swabs were subjected to Gram-stain and culture on Sabouraud dextrose agar. Species identification of Candida isolates was done using phenotypic methods including germ tube test, Rice Tween-80 agar, Chrom ID (CAN2 agar and API 20C AUX, while PCR-RFLP was used as the gold standard method. Antifungal susceptibility testing was done using the disk diffusion method. Results: Vaginal swab cultures yielded Candida growth in 63 cases (50.4%. Candida albicans was the predominant isolated species (60.3% while the most common non-albicans species was Candida glabrata (12.7%. Forty-five (71.4% and fifty-five (87.3% Candida isolates were correctly speciated by Rice Tween-80 Agar and API 20C AUX, respectively, while fifty-seven isolates (90.5% were correctly assigned into the 3 groups of yeasts identified by CAN2 agar. Amphotericin B was more effective than azoles against vaginal Candida isolates. Conclusion: C. albicans is the most common species associated with VVC. API 20C AUX was the most accurate phenotypic method for the proper identification of most Candida species whereas PCR-RFLP could properly confirm Candida species identification genotypically.

  8. Molecular identification and antifungal susceptibility profiles of Candida parapsilosis complex species isolated from culture collection of clinical samples

    Directory of Open Access Journals (Sweden)

    Fábio Silvestre Ataides

    2015-08-01

    Full Text Available AbstractINTRODUCTION:Candida parapsilosis is a common yeast species found in cases of onychomycosis and candidemia associated with infected intravascular devices. In this study, we differentiated Candida parapsilosis sensu stricto, Candida orthopsilosis , and Candida metapsilosis from a culture collection containing blood and subungual scraping samples. Furthermore, we assessed the in vitro antifungal susceptibility of these species to fluconazole, itraconazole, voriconazole, posaconazole, amphotericin B, and caspofungin.METHODS:Differentiation of C. parapsilosis complex species was performed by amplification of the secondary alcohol dehydrogenase (SADH gene and digestion by the restriction enzyme Ban I. All isolates were evaluated for the determination of minimal inhibitory concentrations using Etest, a method for antifungal susceptibility testing.RESULTS:Among the 87 isolates, 78 (89.7% were identified as C. parapsilosis sensu stricto , five (5.7% were identified as C. orthopsilosis , and four (4.6% were identified as C. metapsilosis . Analysis of antifungal susceptibility showed that C. parapsilosis sensu strictoisolates were less susceptible to amphotericin B and itraconazole. One C. parapsilosis sensu stricto isolate was resistant to amphotericin B and itraconazole. Moreover, 10.2% of C. parapsilosis sensu stricto isolates were resistant to caspofungin. Two C. parapsilosis sensu strictoisolates and one C. metapsilosis isolate were susceptible to fluconazole in a dose-dependent manner.CONCLUSIONS:We reported the first molecular identification of C. parapsilosiscomplex species in State of Goiás, Brazil. Additionally, we showed that although the three species exhibited differences in antifungal susceptibility profiles, the primary susceptibility of this species was to caspofungin.

  9. Species distribution and antifungal susceptibility of candidemia at a multispecialty center in North India

    Directory of Open Access Journals (Sweden)

    Maria Thomas

    2016-01-01

    Full Text Available Introduction: Fungi have emerged as major opportunistic pathogens. Candida species account for nearly 96% of all opportunistic mycoses and is an important cause of bloodstream infections. There has been a progressive shift from the predominance of Candida albicans to nonalbicans Candida species as the major cause of candidemia all over the world. Resistance to antifungal drugs is more in nonalbicans Candida species. Hence, speciation and antifungal susceptibility testing is the need of the hour. Materials and Methods: This retrospective study was conducted in a multispecialty center in North India from January 1, 2014 to March 31, 2015. The blood culture samples that were positive for Candida species were processed further. Species identification was done by standard microbiological techniques. Antifungal drug susceptibility was done by disk diffusion method (Clinical and Laboratory Standards Institute M44-A2. Results: A total of 10893 samples were processed, 1440 (13.2% blood cultures were positive. Candida species was isolated from 105 (7.3% samples, of which 15 (14.3% were C. albicans and 90 (85.7% were nonalbicans Candida. Nonalbicans Candida included Candida tropicalis (50.5%, Candida glabrata (19.0%, Candida parapsilosis (14.3% and one isolate each of Candida guillermondi and Candida krusei. Majority of the Candida spp. isolates were resistant to clotrimazole (55.5% fluconazole (42% and itraconazole (69% and and ketoconazole (38%. All isolates were uniformly sensitive to amphotericin B. Conclusion: There is predominance of nonalbicans Candida species in hospital setting. A high index of suspicion, early diagnosis, and a prompt and appropriate therapy remains the cornerstone of treatment.

  10. Diagnosis of oral fungal infection in patients undergoing head and neck cancer radiation. Antifungal susceptibility of isolates

    International Nuclear Information System (INIS)

    Bulacio, L.; Paz, M.; Ramadan, S.; Ramos, L.; Marozzi, M.L.; Sortino, M.; Escovich, L.; Lopez, C.

    2008-01-01

    Radiotherapy adverse effects are very common, they contribute to development of opportunistic infections. Genus Candida is often associated with oral diseases in susceptible patients. The aim of this study was to study the presence of yeast in oral lesions, in patients receiving radiotherapy for head and neck cancer, and to evaluate antifungal susceptibility of isolates. Swabs of oral mucosal lesions of 76 patients were studied. Antifungal susceptibility of the isolates was evaluated, with ATB Fungus-3 method, which tests 5-fluorcitosine (5-FC), amphotericin B (AMB), fluconazole (FCA), itraconazole (ITR) and voriconazole (VRC); and allows the estimation of the minimum inhibitory concentration (MIC). Yeasts were isolated in 74% of samples, being Candida albicans, most frequent specie (53%), followed by C.tropicalis (24%), C.parapsilosis (14%), C.krusei (5%), C.dubliniensis (2%) and Saccharomyces cerevisiae (2%). All strains were susceptible to VRC. For other antifungals, there were resistant or dose-dependent-susceptible strains. Only C.krusei was resistant to the FCA. About AMB, 2 isolates of C. tropicalis presented a value of 2 mg/l MIC, dose with high incidence of adverse effects. These studies are important to establish early and suitable therapy, wich contribute to achieve lowers rates of disseminated forms of candidiasis, and to reduce the difficulties in food intake that carries the presence of oral lesions. (authors)

  11. Species distribution and in vitro antifungal susceptibility of oral yeast isolates from Tanzanian HIV-infected patients with primary and recurrent oropharyngeal candidiasis

    Directory of Open Access Journals (Sweden)

    Rijs Antonius JMM

    2008-08-01

    Full Text Available Abstract Background In Tanzania, little is known on the species distribution and antifungal susceptibility profiles of yeast isolates from HIV-infected patients with primary and recurrent oropharyngeal candidiasis. Methods A total of 296 clinical oral yeasts were isolated from 292 HIV-infected patients with oropharyngeal candidiasis at the Muhimbili National Hospital, Dar es Salaam, Tanzania. Identification of the yeasts was performed using standard phenotypic methods. Antifungal susceptibility to fluconazole, itraconazole, miconazole, clotrimazole, amphotericin B and nystatin was assessed using a broth microdilution format according to the guidelines of the Clinical and Laboratory Standard Institute (CLSI; M27-A2. Results Candida albicans was the most frequently isolated species from 250 (84.5% patients followed by C. glabrata from 20 (6.8% patients, and C. krusei from 10 (3.4% patients. There was no observed significant difference in species distribution between patients with primary and recurrent oropharyngeal candidiasis, but isolates cultured from patients previously treated were significantly less susceptible to the azole compounds compared to those cultured from antifungal naïve patients. Conclusion C. albicans was the most frequently isolated species from patients with oropharyngeal candidiasis. Oral yeast isolates from Tanzania had high level susceptibility to the antifungal agents tested. Recurrent oropharyngeal candidiasis and previous antifungal therapy significantly correlated with reduced susceptibility to azoles antifungal agents.

  12. Prevalence, distribution and antifungal susceptibility profiles of Candida parapsilosis, Candida orthopsilosis and Candida metapsilosis bloodstream isolates.

    Science.gov (United States)

    Bonfietti, Lucas Xavier; Martins, Marilena dos Anjos; Szeszs, Maria Walderez; Pukiskas, Sandra Brasil Stolf; Purisco, Sonia Ueda; Pimentel, Fabiana Cortez; Pereira, Graziella Hanna; Silva, Dayane Cristina; Oliveira, Lidiane; Melhem, Marcia de Souza Carvalho

    2012-07-01

    The Candida parapsilosis group encompasses three species: C. parapsilosis, Candida orthopsilosis and Candida metapsilosis. These species are phenotypically indistinguishable, and molecular methods are needed for their detection. We analysed 152 unique blood culture isolates of the C. parapsilosis group obtained during 1997-2011. The isolates were screened by PCR amplification of the gene encoding secondary alcohol dehydrogenase, followed by digestion with the restriction enzyme BanI. Isolates with RFLP patterns distinct from those of the C. parapsilosis group were characterized as C. parapsilosis sensu stricto (90.8 %), C. orthopsilosis (8.6 %) and C. metapsilosis (0.6 %). Antifungal susceptibility tests indicated that all isolates were susceptible to itraconazole, amphotericin B and caspofungin. Although C. orthopsilosis and C. metapsilosis isolates were susceptible to fluconazole, higher MICs (≥2 mg l(-1)) were observed for C. orthopsilosis. Three isolates (2.0 %) of C. parapsilosis sensu stricto were resistant to voriconazole. Five C. parapsilosis isolates (3.3 %) were intermediate, and a single isolate (0.7 %) was resistant (MIC 16 mg l(-1)) to fluconazole. These data were confirmed using reference strains. It was observed that C. parapsilosis isolates were less susceptible to all triazoles, and this finding deserves further attention to assess the appearance of cross-resistance phenomena. In conclusion, C. metapsilosis and C. orthopsilosis are involved in a small but significant number of invasive infections in Brazil.

  13. Speciation and antifungal susceptibility of esophageal candidiasis in cancer patients in a tertiary care hospital in South India

    Directory of Open Access Journals (Sweden)

    J. Abirami Lakshmy

    2016-01-01

    Full Text Available Esophageal candidiasis is the most common opportunistic infection in patients with altered immunity such as Human Immunodeficiency Virus (HIV infection, cancer patients on chemotherapy and radiotherapy. Neutropenia, irradiation and chemotherapy will facilitate deeper mucosal invasion leading to esophageal candidiasis. Empirical treatment of esophageal candidiasis without antifungal susceptibility testing will lead to the emergence of drug resistant species increasing the morbidity and mortality associated with cancer. The present study aimed to study the frequency of esophageal candida in individuals with cancer, species level identification and antifungal susceptibility pattern. Scrapings of whitish appearing lesions were obtained from a total of thirty five cases of endoscopically identified esophageal candidiasis were obtained from cancer patients. Identification of the Candida isolates were done by cultivation in Sabouraud dextrose agar (SDA, Gram staining, germ tube test, colony morphology in Chrom agar and corn meal agar, sugar assimilation and fermentation tests. Antifungal susceptibility was done by Microbroth dilution method for Fluconazole, Itraconazole and Amphotericin B. We found that Candida albicans was the predominant species isolated followed by Candida tropicalis and Candida glabrata. Sensitivity rates were 94%, 96% and 100% for Fluconazole, Itraconazole and Amphotericin B. Species level identification of Candida isolated from esophageal candidiasis and their antifungal sensitivity testing should be performed for early identification of resistant strains and for promptly treating the cases there by preventing the dissemination of infection in case of immune-compromised individuals. Further the susceptibility pattern will facilitate therapeutic guidance especially in individuals prone to relapse. [J Med Allied Sci 2016; 6(1: 29-34

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

    Directory of Open Access Journals (Sweden)

    Valter Luis Iost Teodoro

    2013-12-01

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

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

    Science.gov (United States)

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

    2016-03-01

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

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

    Science.gov (United States)

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

    2016-07-01

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

  17. Antifungal susceptibility and distribution of Candida spp. isolates from the University Hospital in the municipality of Dourados, State of Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Adriana Araujo de Almeida

    2013-06-01

    Full Text Available Introduction Hospital infections caused by Candida spp. are a leading cause of morbidity and mortality in hospitalized patients, particularly those that are critically ill or immunocompromised. In this study, the distribution of Candida species in isolates from the University Hospital of the Federal University at Grande Dourados and their in vitro susceptibility to antifungal drugs were analyzed. Methods Yeasts were phenotypically identified using classical methodologies. Antifungal susceptibility tests to amphotericin B and fluconazole were performed using the broth microdilution technique. Results A total of 50 Candida isolates were obtained from hospitalized patients during the study period. We analyzed yeast isolates from urine (n=31; 62%, blood (n=12; 24%, and tracheal secretions (n=7; 14%. The following Candida species were identified: C. tropicalis (n=21; 42%, C. albicans (n=18; 36%, C. glabrata (n=10; 20%, and C. krusei (n=1; 2%. Antifungal susceptibility tests demonstrated that C. albicans was susceptible to both antifungal agents. However, 31.2% of the non-C. albicans Candida isolates displayed dose-dependent susceptibility to fluconazole, and 3.1% were resistant to amphotericin B. Conclusions In contrast to previous reports, our results indicated that C. tropicalis was the most commonly isolated yeast species among the hospital patients. The predominance of non-C. albicans Candida infections confirms the importance of species-level identification for implementing appropriate antifungal therapies.

  18. In vitro susceptibility testing of dermatophytes isolated from pediatric cases in Nigeria against five antifungals Teste de susceptibilidade in vitro de dermatófitos isolados de casos pediátricos na Nigéria contra cinco antifúngicos

    Directory of Open Access Journals (Sweden)

    E.I. Nweze

    2007-10-01

    Full Text Available The antifungal activities of itraconazole, ketoconazole, fluconazole, terbinafine and griseofulvin were tested by broth microdilution methods against 71 isolates of dermatophytes isolated from Nigerian children. Most drugs were very active against all the dermatophytes and the MIC 90 ranged from 0.03 to 8.0 µg/mL. This appears to be the first documented data on the antifungal susceptibility testing of isolates of dermatophytes from Nigerian children.Atividades antifúngicas de itraconazole, ketoconazole, fluconazole, terbinafine e griseofulvina foram testadas por métodos de microdiluição em caldo contra 71 isolados de dermatófitos de crianças nigerianas. A maioria das drogas foi muito ativa contra todos os dermatófitos e o MIC 90 variou de 0,03 a 8,0 µg/mL. Estes parecem ser os primeiros dados documentados sobre os testes de susceptibilidade antifúngica de isolados de dermatófitos de crianças nigerianas.

  19. Clinico-mycological and Antifungal Susceptibility Profiles of Candiduria in A Tertiary Care Hospital From South India

    Directory of Open Access Journals (Sweden)

    Dinoop Korol Ponnambath

    2017-10-01

    Full Text Available Introduction: Candida is one of the common causative agent of Urinary Tract Infections (UTI worldwide. The most common reported species causing UTI is Candida albicans. Incidence of UTI due to non-albicans Candida species. is on rise in recent years because of their better adaptability and increased resistance to antifungals. Susceptibility profile reports of various Candida species. to newer azoles like voriconazole and betaglucan inhibitors (e.g., caspofungin are deficient in India, since the reference broth microdilution method is not widely utilized. In this study, a rapid reliable and easier alternative, VITEK 2 compact system was utilized to determine the antifungal susceptibility profile. Aim: To analyse the clinical and mycological profile with determination of drug susceptibility pattern of Candida isolates from urine samples. Materials and Methods: This observational study was conducted in PSG Institute of Medical Sciences and Research, during April to September 2015. Candida isolated with a colony count of ≥103 CFU/ml of urine from clinically suspected cases of UTI were included in the study. Urine samples (n=3821 from clinically suspected UTI cases (n=3821 were subjected to microscopic examination and semi quantitative estimation of yeast culture obtained by inoculated of calibrated volume of urine onto blood, Mac-conkey and HiCrome UTI agar. Clinical parameters of the cases were obtained for analysis. Speciation of Candida was performed using germ tube test, observation of morphology in corn-meal agar and pigment production in HiChrome Candida differential agar. Confirmation of the species identification and anti-fungal susceptibility profile were obtained using VITEK-2 compact system. Results: Total 101 patients were identified with significant candiduria. Community-Acquired Candiduria (CAC was seen in 11 (10.8% of the cases. 23 (22.7% cases of candiduria were associated with pyuria. Concomitant candidemia was observed in 4 (3

  20. Species distribution and antifungal susceptibility profile of Candida ...

    African Journals Online (AJOL)

    Candiduria refers to the presence of Candida species in urine, It is a common nosocomial infection afflicting the urinary tract. The aim of our study was to determine the prevalence of candiduria in hospitalized patients in Dschang District Hospital, and to evaluate the susceptibility patterns of Candida spp isolated from some ...

  1. Antifungals susceptibility pattern of Candida spp . isolated from ...

    African Journals Online (AJOL)

    The highest susceptibility of the isolates was seen for nystatin 62 (83.78%), ketoconazole 61 (82.43%) and fluconazole 60 (81.08%). Conclusion: Despite the noticeable resistance of Candida spp. isolates to miconazole and itraconazole, the results indicate that nystatin, ketoconazole and fluconazole are the drugs of choice ...

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

    Science.gov (United States)

    Sharifzadeh, Aghil; Shokri, Hojjatollah

    2016-01-01

    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). 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). 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. Results of this study indicated that the oils from medicinal plants could be used as potential anti FLU-resistant C. albicans agents.

  3. Antifungal Susceptibilities of Sporothrix albicans, S. brasiliensis, and S. luriei of the S. schenckii Complex Identified in Brazil▿

    Science.gov (United States)

    Oliveira, Daniele C.; Lopes, Paulo G. Markus; Spader, Tatiana B.; Mahl, Camila D.; Tronco-Alves, Giordano R.; Lara, Valeria M.; Santurio, Janio M.; Alves, Sydney Hartz

    2011-01-01

    We studied 40 strains of the species complex formerly classified as the single species Sporothrix schenckii to identify new species within this complex and evaluate their antifungal susceptibility profiles. Based on phenotypic tests (ability to grow at 37°C, colony diameters, and pigmentation of the colonies, as well as assimilation of sucrose and raffinose) and molecular assays (amplification of a fragment of the calmodulin gene), here we report the identification of S. albicans, S. brasiliensis, S. luriei, and S. schenckii; two isolates of these species were detected as itraconazole-resistant strains. PMID:21653757

  4. Epidemiology and antifungal susceptibility of candidemia isolates of non-albicans Candida species from cancer patients

    Science.gov (United States)

    Wu, Ping-Feng; Liu, Wei-Lun; Hsieh, Min-Han; Hii, Ing-Moi; Lee, Yu-Lin; Lin, Yi-Tsung; Ho, Mao-Wang; Liu, Chun-Eng; Chen, Yen-Hsu; Wang, Fu-Der

    2017-01-01

    Candidemia is a growing concern worldwide, and its species distribution has shifted toward non-albicans Candida in recent decades, especially in patients with malignancy. This study aimed to update the epidemiology and antifungal susceptibility of non-albicans candidemia isolates from the cancer patients. Adult cancer patients with non-albicans candidemia were recruited, and clinical data were retrospectively collected from five medical centers in Taiwan from 1 July 2011 to 30 June 2014. In vitro susceptibility was determined by the broth dilution method using a Sensititre YeastOne system and interpreted according to the guidelines of the Clinical and Laboratory Standards Institute. A total of 346 episodes of non-albicans candidemia were identified in cancer patients. Candida tropicalis was the most common species (n=145, 41.9%) and had the highest resistance rate to fluconazole (n=17, 13.9%) among all the preserved isolates, including C. tropicalis, Candida glabrata and Candida parapsilosis. A higher Charlson comorbidity index, non-albicans candidemia due to C. tropicalis, neutropenia and septic shock were independent predictors of 28-day mortality. In conclusion, the species distribution and antifungal susceptibility of non-albicans candidemia isolates in our study differed from those in Western countries, providing useful information about local epidemiology for the selection of empirical antifungal agents for cancer patients. PMID:29018251

  5. [Distribution and antifungal susceptibility of Candida clinical isolations coming from six health care centers in the metropolitan area of Caracas, Venezuela (years 2003-2005)].

    Science.gov (United States)

    Dolande Franco, Maribel E; Reviákina, Vera; Panizo, María Mercedes; Macero, Carolina; Moreno, Xiomara; Calvo, Alberto; Selgrad, Sofía; Papatzikos, Juana; Vergara, Vivian; Mendoza, María José

    2008-03-01

    The aim of this study was to investigate the frequency and antifungal susceptibility of Candida clinical isolations coming from patients with candidiasis in six health care centers of Caracas, Venezuela metropolitan area. The laboratory reports were retrospectively revised from January 2003 through August 2005. The isolated yeasts identification was carried out by conventional methods and antifungal susceptibility was evaluated by ATB-fungus (bioMérieux, France) and Etest (AB Biodisk, Solna, Sweden). One thousand nine hundred seventy seven (1.977) yeasts were studied and their susceptibility testing were carried out only in 1,414 of them. C. albicans was the most isolated yeast (46.7%) and none-albicans Candida-species represented more than half of the isolations (53.4%). All the isolated yeasts evaluated presented CMIsanfotericina B and showed variable susceptibility percentages to fluconazole (91.5%), itraconazole (80%) and voriconazole (98.6%).

  6. In vitro susceptibility testing of dermatophytes isolated in Goiania, Brazil, against five antifungal agents by broth microdilution method Teste de suscetibilidade in vitro de dermatófitos isolados em Goiânia, Brasil, contra cinco agentes antifúngicos pelo método de microdiluição em caldo

    Directory of Open Access Journals (Sweden)

    Crystiane Rodrigues Araújo

    2009-02-01

    Full Text Available The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 ºC allowing a reading of the minimal inhibitory concentration (MIC after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 µg/mL were found for 33.3%, 31.6% and 15% of isolates for itraconazole, ketoconazole and terbinafine, respectively.Atividades antifúngicas de fluconazol, itraconazol, cetoconazol, terbinafina e griseofulvina foram testadas pelo método de microdiluição em caldo contra 60 isolados de dermatófitos. Os resultados mostraram que todos os isolados produziram crescimento claramente detectável a 28 ºC e a concentração inibitória mínima (CIM foi determinada após quatro dias de incubação para Trichophyton mentagrophytes e cinco dias para T. rubrum e Microsporum canis. A maioria dos isolados teve um padrão uniforme de suscetibilidade para os agentes antifúngicos testados. Baixos valores de CIM como 0,03 µg/mL foram encontrados para 33,3%, 31,6% e 15% dos isolados para itraconazol, cetoconazol e terbinafina, respectivamente.

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

    Science.gov (United States)

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

    2016-09-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

  9. Epidemiology, Species Distribution, Antifungal Susceptibility, and Outcome of Candidemia across Five Sites in Italy and Spain

    Science.gov (United States)

    Merelli, Maria; Righi, Elda; Diaz-Martin, Ana; Rosello, Eva Maria; Luzzati, Roberto; Parra, Anna; Trecarichi, Enrico Maria; Sanguinetti, Maurizio; Posteraro, Brunella; Garnacho-Montero, Jose; Sartor, Assunta; Rello, Jordi; Tumbarello, Mario

    2013-01-01

    Candidemia has become an important bloodstream infection that is frequently associated with high rates of mortality and morbidity, and its growing incidence is related to complex medical and surgical procedures. We conducted a multicenter study in five tertiary care teaching hospitals in Italy and Spain and evaluated the epidemiology, species distribution, antifungal susceptibilities, and outcomes of candidemia episodes. In the period of 2008 to 2010, 995 episodes of candidemia were identified in these hospitals. The overall incidence of candidemia was 1.55 cases per 1,000 admissions and remained stable during the 3-year analysis. Candida albicans was the leading agent of infection (58.4%), followed by Candida parapsilosis complex (19.5%), Candida tropicalis (9.3%), and Candida glabrata (8.3%). The majority of the candidemia episodes were found in the internal medicine department (49.6%), followed by the surgical ward, the intensive care unit (ICU), and the hemato-oncology ward. Out of 955 patients who were eligible for evaluation, 381 (39.9%) died within 30 days from the onset of candidemia. Important differences in the 30-day mortality rates were noted between institutions: the lowest mortality rate was in the Barcelona hospital, and the highest rate was in the Udine hospital (33.6% versus 51%, respectively; P = 0.0005). Overall, 5.1% of the 955 isolates tested were resistant or susceptible dose dependent (SDD) to fluconazole, with minor differences between the hospitals in Italy and Spain (5.7% versus 3.5%, respectively; P = 0.2). Higher MICs for caspofungin were found, especially with C. parapsilosis complex (MIC90, 1 μg/ml). Amphotericin B had the lowest MICs. This report shows that candidemia is a significant source of morbidity in Europe, causing a substantial burden of disease and mortality. PMID:24108614

  10. In Vitro Antifungal Susceptibility of Neoscytalidium dimidiatum Clinical Isolates from Malaysia.

    Science.gov (United States)

    James, Jasper Elvin; Santhanam, Jacinta; Lee, Mei Chen; Wong, Choon Xian; Sabaratnam, Parameswari; Yusoff, Hamidah; Tzar, Mohd Nizam; Razak, Mohd Fuat Abdul

    2017-04-01

    Neoscytalidium dimidiatum is an opportunistic fungus causing cutaneous infections mostly, which are difficult to treat due to antifungal resistance. In Malaysia, N. dimidiatum is associated with skin and nail infections, especially in the elderly. These infections may be mistaken for dermatophyte infections due to similar clinical appearance. In this study, Neoscytalidium isolates from cutaneous specimens, identified using morphological and molecular methods (28 Neoscytalidium dimidiatum and 1 Neoscytalidium sp.), were evaluated for susceptibility towards antifungal agents using the CLSI broth microdilution (M38-A2) and Etest methods. Amphotericin B, voriconazole, miconazole and clotrimazole showed high in vitro activity against all isolates with MIC ranging from 0.0313 to 1 µg/mL. Susceptibility towards fluconazole and itraconazole was noted in up to 10% of isolates, while ketoconazole was inactive against all isolates. Clinical breakpoints for antifungal drugs are not yet available for most filamentous fungi, including Neoscytalidium species. However, the results indicate that clinical isolates of N. dimidiatum in Malaysia were sensitive towards miconazole, clotrimazole, voriconazole and amphotericin B, in vitro.

  11. Comparison of Quantitative Antifungal Testing Methods for Textile Fabrics.

    Science.gov (United States)

    Imoto, Yasuo; Seino, Satoshi; Nakagawa, Takashi; Yamamoto, Takao A

    2017-01-01

     Quantitative antifungal testing methods for textile fabrics under growth-supportive conditions were studied. Fungal growth activities on unfinished textile fabrics and textile fabrics modified with Ag nanoparticles were investigated using the colony counting method and the luminescence method. Morphological changes of the fungi during incubation were investigated by microscopic observation. Comparison of the results indicated that the fungal growth activity values obtained with the colony counting method depended on the morphological state of the fungi on textile fabrics, whereas those obtained with the luminescence method did not. Our findings indicated that unique characteristics of each testing method must be taken into account for the proper evaluation of antifungal activity.

  12. In vitro susceptibility of Trichosporon beigelii to antifungal agents.

    Science.gov (United States)

    Perparim, K; Nagai, H; Hashimoto, A; Goto, Y; Tashiro, T; Nasu, M

    1996-12-01

    The minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of amphotericin B, flucytosine, miconazole, fluconazole and itraconazole against 21 isolates of Trichosporon beigelii in RPMI-1640 medium were determined using National Committee for Clinical Laboratory Standards (NCCLS) methodology in microdilution method. Most isolates were sensitive to miconazole (MIC90 0.78 microgram/ml), fluconazole (MIC90 6.25 micrograms/ml), and itraconazole (MIC90 0.19 microgram/ml), with the former being the most active agent tested (MFC90 3.12 mu/ml). Although amphotericin B inhibited most strains (MIC range, 0.78-3.12 micrograms/ml), poor fungicidal activity was observed (MFC range, 1.56-12.5 micrograms/ml) showing a pattern of relative resistance in vitro. Flucytosine showed generally poor activity against most isolates tested. These in vitro findings confirm the resistance of T.beigelii to amphotericin B and suggest that azoles may be an alternative to the former for the treatment of disseminated trichosporonosis. However, in vivo studies would better validate these in vitro findings.

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

    Directory of Open Access Journals (Sweden)

    Aghil Sharifzadeh

    2016-03-01

    Full Text Available Objectives: 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

  14. Species distribution and antifungal susceptibility profile of Candida spp. bloodstream isolates from Latin American hospitals

    Directory of Open Access Journals (Sweden)

    Godoy Patrício

    2003-01-01

    Full Text Available From March 1999 to March 2000, we conducted a prospective multicenter study of candidemia involving five tertiary care hospitals from four countries in Latin America. Yeast isolates were identified by classical methods and the antifungal susceptibility profile was determined according to the National Committee for Clinical Laboratory Standards microbroth assay method. During a 12 month-period we were able to collect a total of 103 bloodstream isolates of Candida spp. C. albicans was the most frequently isolated species accounting for 42% of all isolates. Non-albicans Candida species strains accounted for 58% of all episodes of candidemia and were mostly represented by C. tropicalis (24.2% and C. parapsilosis (21.3%. It is noteworthy that we were able to identify two cases of C. lusitaniae from different institutions. In our casuistic, non-albicans Candida species isolates related to candidemic episodes were susceptible to fluconazole. Continuously surveillance programs are needed in order to identify possible changes in the species distribution and antifungal susceptibility patterns of yeasts that may occurs after increasing the use of azoles in Latin American hospitals.

  15. Antifungal susceptibility of Candida species isolated from patients with candidemia in southern Taiwan, 2007-2012: impact of new antifungal breakpoints.

    Science.gov (United States)

    Chen, Yi-Chun; Kuo, Shu-Fang; Chen, Fang-Ju; Lee, Chen-Hsiang

    2017-02-01

    The Clinical and Laboratory Standard Institute (CLSI) revised the clinical breakpoints (CBPs) for the azoles and echinocandins against Candida species in 2012. We aimed to report the epidemiology of candidemia and antifungal susceptibility of Candida species and evaluate the impact of new CBPs on antifungal susceptibility in our region. All blood isolates of Candida species were obtained from 2007 to 2012. The minimum inhibitory concentrations of fluconazole, voriconazole, echinocandins and flucytosine against Candida isolates were determined by Sensititre YeastOne system. Differences in susceptibility rates between the CBPs of previous and revised versions of CLSI were examined. Of 709 Candida isolates, the fluconazole-susceptible rate was 96.5% in Candida albicans, 85.8% in Candida tropicalis and 92.1% in Candida parapsilosis by the revised CBPs. Compared with the susceptibility results by previous CBPs, the marked reductions in susceptibility of C. albicans, C. tropicalis and C. parapsilosis to fluconazole, that of C. tropicalis and C. parapsilosis to voriconazole, that of C. tropicalis and Candida glabrata to anidulafungin and that of C. tropicalis, C. glabrata and Candida krusei to caspofungin by revised CBPs were found. In conclusion, Candida albicans and C. parapsilosis remain highly susceptible to fluconazole. The non-susceptible rates of Candida species to azoles and echinocandins increase with interpretation by the revised CBPs. © 2016 Blackwell Verlag GmbH.

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

    Science.gov (United States)

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

    2017-05-15

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

  17. 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.

    Science.gov (United States)

    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. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Identification and antifungal susceptibility of Candida species isolated from the urine of patients in a university hospital in Brazil

    Directory of Open Access Journals (Sweden)

    Gláucia Moreira Espíndola Lima

    2017-12-01

    Full Text Available ABSTRACT The aim of this study was to identify Candida spp. isolated from candiduria episodes at a tertiary hospital in the Midwest region of Brazil, and to determine their susceptibility profiles to antifungal compounds. From May 2011 to April 2012, Candida spp. isolated from 106 adult patients with candiduria admitted to the University Hospital of the Federal University of Mato Grosso do Sul were evaluated. Both, species identification and susceptibility testing with fluconazole-FLC, voriconazole-VRC, and amphotericin B-AmB were carried out using the Vitek 2. To discriminate species of the C. parapsilosis complex, a RAPD-PCR technique using the RPO2 primer was performed. From the total of 106 isolates, 42 (39.6% C. albicans and 64 (60.4% Candida non-albicans (CNA - 33 C. tropicalis, 18 C. glabrata, 5 C. krusei, 4 C. parapsilosis sensu stricto, 2 C. kefyr, 1 C. lusitaniae, and 1 C. guilliermondii were identified. All isolates were susceptible to AmB and VRC, whereas all C. glabrata isolates presented either resistance (5.6% or dose-dependent susceptibility (94.4% to FLC. The study of Candida spp. and their resistance profiles may help in tailoring more efficient therapeutic strategies for candiduria.

  19. Correlation of anti-fungal susceptibility with clinical outcomes in patients with cryptococcal meningitis

    Directory of Open Access Journals (Sweden)

    Lee Chen-Hsiang

    2012-12-01

    Full Text Available Abstract Background This study aimed to investigate the correlation of minimum inhibiting concentrations (MICs, obtained by broth micro-dilution, and clinical response in patients with cryptococcal meningitis. Methods Using retrospective analyses covering the period 2001–2010, factors affecting clinical therapeutic cure in patients with cryptococcal meningitis 10 weeks after the start of anti-fungal therapy were identified. Specific emphasis was placed on the role of anti-fungal susceptibility. Results Of 46 patients with cryptococcal meningitis identified, 21 were cured after 10 weeks of treatment. Overall, 12 strains (26.1% were resistant to fluconazole (>8 μg/ml and 8 (17.4% had an MIC >1 μg/ml for amphotericin B. Twenty-three patients received combination amphotericin B and fluconazole as their initial antifungal therapy, 17 were given amphotericin B only, five received fluconazole only, and one received a combination of amphotericin B and flucytosine. After 2 weeks, all patients received fluconazole (400–600 mg daily for 8 weeks at least, then 200 mg daily thereafter. The presence of isolates resistant to fluconazole (MIC >8 μg/ml; 4.8% vs. 44%, p 8 μg/ml, was an independent predictor of therapeutic cure at 10-week evaluation (OR = 15.7; 95% CI: 1.8-135.9; p = 0.01, but higher MIC of amphotericin B (>1 μg/ml was not. Conclusions The MICs of fluconazole, determined by the CLSI method, may be a potential predictor of therapeutic cure in patients with cryptococcal meningitis.

  20. Genetic diversity and antifungal susceptibility profiles in causative agents of sporotrichosis

    Science.gov (United States)

    2014-01-01

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

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

    NARCIS (Netherlands)

    Kathuria, S.; Singh, P.K.; Meis, J.F.G.M.; Chowdhary, A.

    2014-01-01

    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

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

    Science.gov (United States)

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

    2014-08-01

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

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

    Science.gov (United States)

    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.

  4. Identification and functional characterization of Rca1, a transcription factor involved in both antifungal susceptibility and host response in Candida albicans.

    Science.gov (United States)

    Vandeputte, Patrick; Pradervand, Sylvain; Ischer, Françoise; Coste, Alix T; Ferrari, Sélène; Harshman, Keith; Sanglard, Dominique

    2012-07-01

    The identification of novel transcription factors associated with antifungal response may allow the discovery of fungus-specific targets for new therapeutic strategies. A collection of 241 Candida albicans transcriptional regulator mutants was screened for altered susceptibility to fluconazole, caspofungin, amphotericin B, and 5-fluorocytosine. Thirteen of these mutants not yet identified in terms of their role in antifungal response were further investigated, and the function of one of them, a mutant of orf19.6102 (RCA1), was characterized by transcriptome analysis. Strand-specific RNA sequencing and phenotypic tests assigned Rca1 as the regulator of hyphal formation through the cyclic AMP/protein kinase A (cAMP/PKA) signaling pathway and the transcription factor Efg1, but also probably through its interaction with a transcriptional repressor, most likely Tup1. The mechanisms responsible for the high level of resistance to caspofungin and fluconazole observed resulting from RCA1 deletion were investigated. From our observations, we propose that caspofungin resistance was the consequence of the deregulation of cell wall gene expression and that fluconazole resistance was linked to the modulation of the cAMP/PKA signaling pathway activity. In conclusion, our large-scale screening of a C. albicans transcription factor mutant collection allowed the identification of new effectors of the response to antifungals. The functional characterization of Rca1 assigned this transcription factor and its downstream targets as promising candidates for the development of new therapeutic strategies, as Rca1 influences host sensing, hyphal development, and antifungal response.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Science.gov (United States)

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

    2017-02-01

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

  8. Dataset on preparation of the phosphorylated counterparts of a Momordica charantia protein for studying antifungal activities against susceptible dose-dependent C. albicans to antimycotics.

    Science.gov (United States)

    Qiao, Yuanbiao; Song, Li; Zhu, Chenchen; Wang, Qian; Guo, Tianyan; Yan, Yanhua; Li, Qingshan

    2017-12-01

    The data presented here are related to a research article entitled "Development of a phosphorylated Momordica charantia protein system for inhibiting susceptible dose-dependent C. albicans to available antimycotics: An allosteric regulation of protein" (Qiao et al., 2017) [1]. The data set includes three portions: (1) a relationship between reaction velocities of protein phosphorylation as a function of the substrate concentrations, determined in enzymatic reactions in aid of protein kinases; (2) a result of antifungal susceptibility testing of C. albicans after it is selected in antimycotics; and (3) a comparison of protein expression in the susceptible dose-dependent fungus relative to the wild C. albicans . In the first portion, the relationship of reaction velocities and substrate concentrations is expressed as an output from the inverse variation model. All data and analyses are made publicly available and citied in the research article using a style for the Data in Brief.

  9. Comparison between E-test and CLSI broth microdilution method for antifungal susceptibility testing of Candida albicans oral isolates Comparação entre E-test e o método da microdiluição do CLSI para teste de susceptibilidade a antifúngicos de isolados orais de Candida albicans

    Directory of Open Access Journals (Sweden)

    Cristiane Yumi Koga-Ito

    2008-02-01

    Full Text Available Thirty Candida albicans isolated from oral candidosis patients and 30 C. albicans isolated from control individuals were studied. In vitro susceptibility tests were performed for amphotericin B, fluconazole, 5-flucytosine and itraconazole through the Clinical and Laboratorial Standards Institute (CLSI reference method and E test system. The results obtained were analyzed and compared. MIC values were similar for the strains isolated from oral candidosis patients and control individuals. The agreement rate for the two methods was 66.67% for amphotericin B, 53.33% for fluconazole, 65% for flucytosine and 45% for itraconazole. According to our data, E test method could be an alternative to trial routine susceptibility testing due to its simplicity. However, it can not be considered a substitute for the CLSI reference method.Trinta Candida albicans isoladas de pacientes portadores de candidose oral e 30 Candida albicans isoladas de indivíduos controle foram estudadas. Testes de susceptibilidade in vitro foram realizados com anfotericina B, fluconazol, 5-flucitosina e itraconazol pelo método do Clinical and Laboratorial Standars Institute (CLSI e por E-test. Os resultados obtidos foram analisados e comparados. Os valores de CIM foram semelhantes para amostras isoladas de pacientes portadores de candidose oral e indivíduos controle. A concordância entre os dois métodos foi de 66,7% para a anfotericina B, 53,33% para o fluconazol, 65% para a flucitosina e 45% para o itraconazol. De acordo com estes resultados, o método do E-test poderia ser uma alternativa para a triagem de casos de rotina pela sua simplicidade. Entretanto, este método não pode ser considerado como um substituto para o método de referência do CLSI.

  10. Epidemiological data and antifungal susceptibility in invasive fungal infections - a Romanian infectious diseases tertiary hospital’s experience. Preliminary report

    Directory of Open Access Journals (Sweden)

    Agrosoaie Radu

    2017-10-01

    Full Text Available Introduction: Invasive fungal infections have stood as an important research subject for the past 20 years, being considered as a crucial effect of advancing healthcare services. Low identification rates of invasive fungal infections in blood cultures and low sensibility of biomarkers determine empiric treatments which lead to a change in epidemiological data and antifungal susceptibility. The aim: The epidemiological evaluation of invasive fungal infections and the assessment of antifungal resistance related to this condition. Methods and material: An “antifungal stewardship” retrospective study was developed between January 2010 and April 2016. An epidemiological analysis was performed on 79 cases with proven invasive fungal infections in bloodstream, catheter, and cerebrospinal fluid. We considered: age, gender, HIV status, place of residence, and first option in medical practice of antifungal treatment. The laboratory analysis was performed by the Microbiology Laboratory at “Prof. Dr. Matei Bals” National Institute for Infectious Diseases, Bucharest. Minimum inhibitory concentrations (MIC’s of 15 isolates were identified using colorimetric micro broth dilution panel YEASTONE ®YO10 and compared with susceptibilities obtained by VITEK2®C system. Candida parapsilosis ATCC 22019 was used as reference. Results: The incidence of invasive fungal infections was 3.7 on 1000 hospitalized patients. The age of the study population ranged between 12 and 83 years, and most were male (59%. The majority of subjects were from an urban area (84%, and 27% of them were HIV positive. The results obtained in VITEK2C® were similar with those from YEASTONE® YO10 for fluconazole, voriconazole, amphotericin B (100%, without any minor, major or very major errors. The fluconazole was the first option of treatment, followed by voriconazole, caspofungin, anidulafungin. In 37% of cases the first treatment option was replaced with a secondary antifungal

  11. Genotyping of the MTL loci and susceptibility to two antifungal agents of Candida glabrata clinical isolates

    Directory of Open Access Journals (Sweden)

    María Teresa Lavaniegos-Sobrino

    2009-08-01

    Full Text Available The opportunistic fungal pathogen Candida glabrata is the second most common isolate from bloodstream infections worldwide and is naturally less susceptible to the antifungal drug fluconazole than other Candida species. C. glabrata is a haploid yeast that contains three mating-type like loci (MTL, although no sexual cycle has been described. Strains containing both types of mating information at the MTL1 locus are found in clinical isolates, but it is thought that strains containing type a information are more common. Here we investigated if a particular combination of mating type information at each MTLlocus is more prevalent in clinical isolates from hospitalized patients in Mexico and if there is a correlation between mating information and resistance to fluconazole and 5-fluorocytosine. We found that while both types of information at MTL1 are equally represented in a collection of 64 clinical isolates, the vast majority of isolates contain a-type information at MTL2 and α-type at MTL3. We also found no correlation of the particular combination of mating type information at the three MTL loci and resistance to fluconazole.

  12. Yeasts from Macrobrachium amazonicum: a focus on antifungal susceptibility and virulence factors of Candida spp.

    Science.gov (United States)

    Brilhante, Raimunda S N; Paiva, Manoel A N; Sampaio, Célia M S; Teixeira, Carlos E C; Castelo-Branco, Débora S C M; Leite, João J G; Moreira, Camila A; Silva, Liliane P; Cordeiro, Rossana A; Monteiro, André J; Sidrim, José J C; Rocha, Marcos F G

    2011-05-01

    In the present study, it was sought to compare yeast microbiota of wild and captive Macrobrachium amazonicum and evaluate the antifungal susceptibility and production of virulence factors by the recovered isolates of Candida spp. Additionally, cultivation water was monitored for the presence of fungi. Overall, 26 yeast isolates belonging to three genera and seven species were obtained, out of which 24 were Candida spp., with Candida famata as the most prevalent species for both wild and captive prawns. From cultivation water, 28 isolates of filamentous fungi were obtained, with Penicillium spp., Cladosporium spp. and Aspergillus spp. as the most frequent genera. Eight out of 24 Candida spp. isolates were resistant to azole derivatives, out of which four were recovered from wild-harvested prawns. As for production of virulence factors, three (12.5%) and eight (33.3%) isolates presented phospholipase and protease activity, respectively. This is the first comparative study between wild and captive prawns and the first report on yeast microbiota of M. amazonicum. The most relevant finding was the high percentage of resistant Candida spp., including from wild individuals, which suggests the occurrence of an environmental imbalance in the area where these prawns were captured. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Ana ALASTRUEY-IZQUIERDO

    2015-09-01

    Full Text Available SUMMARYDuring 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.

  14. Utility of in-house fluconazole disk diffusion susceptibility testing in the treatment of candidemia.

    Science.gov (United States)

    Kubiak, David W; Farmakiotis, Dimitrios; Arons, Viktoria; Hollins, Randy M; Rostas, Sara E; Weiser, Linda M; Baden, Lindsey R; Marty, Francisco M; Koo, Sophia

    2016-03-01

    Among 302 first candidemia episodes, 210 (69.6%) were initially treated with an echinocandin or polyene (E/P) antifungal drug. In 137 (72.5%) patients with fluconazole-susceptible isolates, treatment was changed to fluconazole based on disk diffusion susceptibility testing. Clinical outcomes were not compromised in patients receiving E/P who were de-escalated to fluconazole for treatment of candidemia based on disk diffusion results. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Antifungal effect of Trachyspermum ammi against susceptible and fluconazole-resistant strains of Candida albicans.

    Science.gov (United States)

    Sharifzadeh, A; Khosravi, A R; Shokri, H; Sharafi, G

    2015-06-01

    Trachyspermum ammi (T. ammi) has been known as having many therapeutic properties and its antimicrobial activity has currently received a renewed interest. This study aimed to verify the effectiveness of T. ammi essential oil to inhibit the growth of Candida albicans (C. albicans) strains isolated from HIV(+) patients with oropharyngeal candidiasis (OPC). The essential oil was obtained by hydrodistillation in a Clevenger apparatus and analyzed by gas chromatography. Susceptibility tests were expressed as inhibition zone by the disk diffusion method and minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) by the broth microdilution method. Thymol (63.4%), p-cymene (19%) and γ-terpinen (16.9%) were found as the most abundant constituents. The disk diffusion results revealed that 67% of oral C. albicans isolates were susceptible, 9% susceptible-dose dependent and 24% resistant to fluconazole. In the broth microdilution method, 68% of isolates were susceptible, 5% susceptible-dose dependent and 27% resistant to fluconazole. The increase in concentration led to a significant reduction in yeasts that were growing in exponential phase. In addition, with increasing in T. ammi oil concentration, the time of remaining cells in lag phase was significantly increased. This study showed that all clinical C. albicans isolates were susceptible to T. ammi essential oil, indicating a significant reduction in the yeast growth in exponential phase. Copyright © 2015. Published by Elsevier Masson SAS.

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

    Science.gov (United States)

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

    2016-12-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  18. [Susceptibility of Candida albicans blood isolates to 3 antifungal drugs: retrospective study in Rio Grande do Sul, Brazil, 1999-2009].

    Science.gov (United States)

    Mattei, Antonella Souza; Alves, Sydney Hartz; Mario, Débora Alves; Watte, Guilherme; Severo, Cecília Bittencourt; Guazzelli, Luciana da Silva; Oliveira, Flávio de Mattos; Severo, Luiz Carlos

    2013-01-01

    Candidiasis is one of the most important among recurrent invasive yeast infections in patients, thus antifungal treatment becomes a challenge. The aim of this study was to evaluate the in vitro activity of clinical Candida albicans isolates from blood cultures to fluconazole, amphotericin B and anidulafungin, in a hospital from Rio Grande do Sul, Brazil. The susceptibility of 153 isolates to the 3 drugs mentioned was tested according to Clinical and Laboratory Standars Institute. Minimal inhibitory and fungicidal concentrations (MIC, MFC, respectively) of each drug were determined, as well as the epidemiological cutoff value (ECV). All of the isolates were susceptible to anidulafungin, MIC and MFC ≤ 1 μg/ml; however, when compared with ECV, 3% of the isolates exhibited higher values against fluconazole, 96% were susceptible, 3% susceptible dose-dependent, and 1% resistant. Also, it was observed that 21% of the isolates exhibited higher values than ECV. One isolate was resistant to amphotericin B; the other ones, susceptible, based on the MFC; furthermore, 1.5% of the isolates exhibited higher values. C. albicans isolates exhibited more susceptibility to anidulafungin, and 90% of them (MIC90) exhibited the lowest values against amphotericin B. Based on ECV and Pfaller classification, isolates could be resistant to fluconazole, demonstrating the importance of the combination of these parameters. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  19. Dermatophyte susceptibilities to antifungal azole agents tested in vitro by broth macro and microdilution methods Suscetibilidade in vitro de dermatófitos a azóis pelos métodos macro e microdiluição em caldo

    Directory of Open Access Journals (Sweden)

    Emerson Roberto Siqueira

    2008-02-01

    Full Text Available The in vitro susceptibility of dermatophytes to the azole antifungals itraconazole, fluconazole and ketoconazole was evaluated by broth macro and microdilution methods, according to recommendations of the CLSI, with some adaptations. Twenty nail and skin clinical isolates, four of Trichophyton mentagrophytes and 16 of T. rubrum were selected for the tests. Itraconazole minimal inhibitory concentrations (MIC varied from Foi avaliada a suscetibilidade in vitro de dermatófitos aos antifúngicos itraconazol, fluconazol e cetoconazol, pelos métodos macro e microdiluição em caldo, de acordo com as recomendações do CLSI, com algumas modificações. Foram estudados 20 isolados clínicos de lesões de unha e pele, sendo quatro Trichophyton mentagrophytes e 16 T. rubrum. A concentração inibitória mínima (CIM para itraconazol variou de < 0,03 a 0,25 µg/mL pelo método da macrodiluição, e de < 0,03 a 0,5 µg/mL pela microdiluição em caldo; de 0,5 a 64 µg/mL e de 0,125 a 16 µg/mL para fluconazol, respectivamente, pela macro e microdiluição; e de < 0,03 a 0,5 µg/mL por ambos os métodos para cetoconazol. A concordância entre os dois métodos (considerando ± uma diluição foi de 70% para itraconazol, 45% para fluconazol e 85% para cetoconazol. Conclui-se que os isolados estudados foram inibidos por concentrações relativamente baixas dos antifúngicos testados, e os dois métodos apresentam boa concordância, especialmente para itraconazol e cetoconazol.

  20. A flow cytometry method for testing the susceptibility of Cryptococcus spp. to amphotericin B.

    Science.gov (United States)

    Benaducci, Tatiane; Matsumoto, Marcelo Teruyuki; Sardi, Janaina Cássia Orlandi; Fusco-Almeida, Ana Marisa; Mendes-Giannini, Maria José Soares

    2015-01-01

    Human fungal infections have increased at an alarming rate in recent years, particularly in immunocompromised individuals. Cryptococcosis is the second most prevalent systemic fungal infection worldwide, and the most prevalent systemic infection in immunocompromised individuals, representing more than 70% of cases. The incidence of cryptococcosis is high in people with HIV/acquired immunodeficiency syndrome (AIDS), with recent estimates indicating that there are one million cases of cryptococcal meningitis globally per year in AIDS patients. The aim of this research was to develop a rapid flow cytometric antifungal susceptibility test and to compare the results with the standard methods. A reference strain and clinical isolates of Cryptococcus neoformans and Cryptococcus gattii were tested for susceptibility to amphotericin B by flow cytometry using propidium iodide as indicator of viability. Flow cytometry (FC) results were compared with the minimum inhibitory concentration (MIC) values determined by microdilution. The antifungal activity of amphotericin B ranged from MICs of 0.06 to 2μg/ml for the 11 isolates studied. The same results were found by FC. The FC method allows same-day results, assisting in the selection of appropriate antifungal therapies. These results demonstrate an excellent correlation between FC and the classic methods of testing for susceptibility to antifungal agents. This rapid diagnosis method makes it possible to quickly administer effective therapeutic interventions, often saving lives. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  1. Antifungal susceptibility and test for cure of candida species among ...

    African Journals Online (AJOL)

    African Journal of Clinical and Experimental Microbiology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 19, No 1 (2018) >. Log in or Register to get access to full text downloads.

  2. Evaluation of Virulence FactorsIn vitro, Resistance to Osmotic Stress and Antifungal Susceptibility ofCandida tropicalisIsolated from the Coastal Environment of Northeast Brazil.

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  4. Antifungal Efficacy during Candida krusei Infection in Non-Conventional Models Correlates with the Yeast In Vitro Susceptibility Profile

    Science.gov (United States)

    Scorzoni, Liliana; de Lucas, Maria Pilar; Mesa-Arango, Ana Cecilia; Fusco-Almeida, Ana Marisa; Lozano, Encarnación; Cuenca-Estrella, Manuel; Mendes-Giannini, Maria Jose; Zaragoza, Oscar

    2013-01-01

    The incidence of opportunistic fungal infections has increased in recent decades due to the growing proportion of immunocompromised patients in our society. Candida krusei has been described as a causative agent of disseminated fungal infections in susceptible patients. Although its prevalence remains low among yeast infections (2–5%), its intrinsic resistance to fluconazole makes this yeast important from epidemiologic aspects. Non mammalian organisms are feasible models to study fungal virulence and drug efficacy. In this work we have used the lepidopteran Galleria mellonella and the nematode Caenorhabditis elegans as models to assess antifungal efficacy during infection by C. krusei. This yeast killed G. mellonella at 25, 30 and 37°C and reduced haemocytic density. Infected larvae melanized in a dose-dependent manner. Fluconazole did not protect against C. krusei infection, in contrast to amphotericin B, voriconazole or caspofungin. However, the doses of these antifungals required to obtain larvae protection were always higher during C. krusei infection than during C. albicans infection. Similar results were found in the model host C. elegans. Our work demonstrates that non mammalian models are useful tools to investigate in vivo antifungal efficacy and virulence of C. krusei. PMID:23555877

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

    Directory of Open Access Journals (Sweden)

    Laura Bedin Denardi

    2015-03-01

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

  6. Comparison of species-level identification and antifungal susceptibility results from diagnostic and reference laboratories for bloodstream Candida surveillance isolates, South Africa, 2009-2010.

    Science.gov (United States)

    Naicker, Serisha D; Govender, Nevashan; Patel, Jaymati; Zietsman, Inge L; Wadula, Jeannette; Coovadia, Yacoob; Kularatne, Ranmini; Seetharam, Sharona; Govender, Nelesh P

    2016-11-01

    From February 2009 through August 2010, we compared species-level identification of bloodstream Candida isolates and susceptibility to fluconazole, voriconazole, and caspofungin between diagnostic and reference South African laboratories during national surveillance for candidemia. Diagnostic laboratories identified isolates to genus/species level and performed antifungal susceptibility testing, as indicated. At a reference laboratory, viable Candida isolates were identified to species-level using automated systems, biochemical tests, or DNA sequencing; broth dilution susceptibility testing was performed. Categorical agreement (CA) was calculated for susceptibility results of isolates with concordant species identification. Overall, 2172 incident cases were detected, 773 (36%) by surveillance audit. The Vitek 2 YST system (bioMérieux Inc, Marcy l'Etoile, France) was used for identification (360/863, 42%) and susceptibility testing (198/473, 42%) of a large proportion of isolates. For the five most common species (n = 1181), species-level identification was identical in the majority of cases (Candida albicans: 98% (507/517); Candida parapsilosis: 92% (450/488); Candida glabrata: 89% (89/100); Candida tropicalis: 91% (49/54), and Candida krusei: 86% (19/22)). However, diagnostic laboratories were significantly less likely to correctly identify Candida species other than C. albicans versus C. albicans (607/664, 91% vs. 507/517, 98%; P Diagnostic laboratories significantly under-reported fluconazole resistance in C. parapsilosis (225/393, 57% vs. 239/393, 61%; P Diagnostic laboratories were less likely to correctly identify Candida species other than C. albicans, under-reported fluconazole resistance for C. parapsilosis and over-reported fluconazole resistance for C. albicans. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Real-Time Optical Antimicrobial Susceptibility Testing

    DEFF Research Database (Denmark)

    Fredborg, Marlene; Andersen, Klaus R; Jørgensen, Erik

    2013-01-01

    , introduces real-time detection of bacterial growth and antimicrobial susceptibility, with imaging material to support the automatically generated graphs. Automated antibiotic susceptibility tests of a monoculture showed statistically significant antibiotic effect within 6 minutes and within 30 minutes...... from multidrug-resistant pathogenic bacteria. The oCelloScope system can be employed for a broad range of applications within bacteriology and may present new vistas as a point-of-care instrument in both clinical and veterinarian settings....

  8. Antianaerobic Antimicrobials: Spectrum and Susceptibility Testing

    Science.gov (United States)

    Wexler, Hannah M.; Goldstein, Ellie J. C.

    2013-01-01

    SUMMARY Susceptibility testing of anaerobic bacteria recovered from selected cases can influence the choice of antimicrobial therapy. The Clinical and Laboratory Standards Institute (CLSI) has standardized many laboratory procedures, including anaerobic susceptibility testing (AST), and has published documents for AST. The standardization of testing methods by the CLSI allows comparisons of resistance trends among various laboratories. Susceptibility testing should be performed on organisms recovered from sterile body sites, those that are isolated in pure culture, or those that are clinically important and have variable or unique susceptibility patterns. Organisms that should be considered for individual isolate testing include highly virulent pathogens for which susceptibility cannot be predicted, such as Bacteroides, Prevotella, Fusobacterium, and Clostridium spp.; Bilophila wadsworthia; and Sutterella wadsworthensis. This review describes the current methods for AST in research and reference laboratories. These methods include the use of agar dilution, broth microdilution, Etest, and the spiral gradient endpoint system. The antimicrobials potentially effective against anaerobic bacteria include beta-lactams, combinations of beta-lactams and beta-lactamase inhibitors, metronidazole, chloramphenicol, clindamycin, macrolides, tetracyclines, and fluoroquinolones. The spectrum of efficacy, antimicrobial resistance mechanisms, and resistance patterns against these agents are described. PMID:23824372

  9. Susceptibility testing of Entamoeba histolytica

    Energy Technology Data Exchange (ETDEWEB)

    Cedeno, J.R.; Krogstad, D.J.

    1983-12-01

    The growth of Entamoeba histolytica in microtiter plates in vitro in a variety of environments with reduced oxygen tensions is reported. With 3% O/sub 2/, 3% CO/sub 2/, and 94% N/sub 2/, the parasite growth in microtiter plates was identical to that in screw-capped culture tubes, as measured by (/sup 3/H)thymidine incorporation and by quantitative parasite counts. There were no significant differences between the drug concentrations necessary to inhibit parasite growth by 50% based on (/sup 3/H)thymidine incorporation vs those defined by quantitative parasite counts for the 15 antimicrobial agents tested (including seven drugs used for the treatment of amebiasis). This technique provides a reproducible method to quantitate the activity of potential antiamebic agents in vitro. The isotopic method should be of particular value in defining the metabolism of the parasite and effects of antimicrobial agents on it, whereas the morphologic method may be more valuable for workers with limited resources available to them.

  10. Molecular basis of antifungal drug resistance in yeasts

    DEFF Research Database (Denmark)

    Morio, Florent; Jensen, Rasmus Hare; Le Pape, Patrice

    2017-01-01

    Besides inherent differences in in vitro susceptibilities, clinically-relevant yeast species may acquire resistance upon exposure to most antifungal drugs used in the clinic. In recent years, major fundamental research studies have been conducted to improve our understanding of the molecular basis......., in the context of antifungal drug resistance. Also included are the methods currently available for in vitro antifungal susceptibility testing and for molecular detection of mutations associated with resistance. Finally, the genetic drivers of antifungal resistance are discussed in light of the spectra...

  11. Species distribution and in vitro antifungal susceptibility of oral yeast isolates from Tanzanian HIV-infected patients with primary and recurrent oropharyngeal candidiasis.

    NARCIS (Netherlands)

    Hamza, O.J.M.; Matee, M.I.N.; Moshi, M.J.; Simon, E.N.; Mugusi, F.; Mikx, F.H.M.; Palenstein Helderman, W.H. van; Rijs, A.J.M.M.; Ven, A.J.A.M. van der; Verweij, P.E.

    2008-01-01

    BACKGROUND: In Tanzania, little is known on the species distribution and antifungal susceptibility profiles of yeast isolates from HIV-infected patients with primary and recurrent oropharyngeal candidiasis. METHODS: A total of 296 clinical oral yeasts were isolated from 292 HIV-infected patients

  12. Epidemiology, species distribution, antifungal susceptibility and outcome of candidemia among Internal Medicine Wards of community hospitals of Udine province, Italy

    Directory of Open Access Journals (Sweden)

    Federico Silvestri

    2014-09-01

    Full Text Available Candidemia is an emerging problem among patients hospitalized in Internal Medicine Wards (IMW. We performed a retrospective study to assess the epidemiology, species distribution, antifungal susceptibility and outcome of candidaemia recorded over a 3-year period (2010-2012 among IMW of community hospitals of Udine province in Italy: forty-eight patients were identified, with an overall incidence of 1.44 cases/1000 hospital admissions/year. Candida albicans was the most frequent species, followed by Candida parapsilosis that accounted for 42.9% of Tolmezzo cases. All isolates were susceptible to amphotericin and caspofungin, while 11.4% of strains were not-susceptible to voriconazole and 14.3% to fluconazole. Crude mortality was 41.7%. In conclusion, in community hospitals overall incidence of candidemia is similar to tertiary care hospitals, but 80% of cases are detected in IMW. Candida species distribution is overlapping, but differences in local epidemiology were found and should be taken into consideration. No resistance to amphotericin and caspofungin was found while resistance to azoles was observed. Knowledge of this data might be useful when planning the best therapeutic strategy.

  13. Surveillance study of species distribution, antifungal susceptibility and mortality of nosocomial candidemia in a tertiary care hospital in China

    Science.gov (United States)

    2013-01-01

    Background Bloodstream infections due to Candida species cause significant morbidity and mortality, and the epidemiology of Candida infection is changing. Surveillance for candidemia is necessary to detect trends in species distribution and antifungal resistance. Methods The medical and electronic records of all patients who had candidemia at the authors’ hospital from 2009 to 2011 were reviewed for demographic data and clinical information, including the infecting Candida species, resistance to antifungals and survival, and the presence of risk factors associated with candidemia. Results A total of 133 distinct episodes of candidemia were identified over the study period. The annual incidence of candidemia ranged between 0.71 and 0.85 cases/1000 hospital discharges. The most frequent Candida species were C. tropicalis (28.6%), followed by C. albicans (23.3%) and C. parapsilosis (19.5%). The rates of susceptibility to antifungal agents were as followed: voriconazole (97.8%), itraconazole (69.5%), fluconazole (46.1%), ketoconazole (38.9%). Out of 131 evaluable patients, 34 (26.0%) died within 30 days from the onset of candidemia. C. tropicalis candidemia was associated with the highest mortality rate (44.7%). Regarding the crude mortality in the different units, patients in Hemato-Oncology ward had the highest mortality rate (66.7%), followed by patients in cardiovascular wards and ICU (57.1% and 25.6%, respectively). Predictors of 30-day mortality were identified by uni- and multivariate analyses. Complicated abdominal surgery, presence of central venous catheter (CVC), neutropenia, candidemia due to C. tropicalis and poor treatment with fluconazole were significantly associated with the 30-day mortality. Presence of CVC (odds ratio[OR] = 4.177; 95% confidence interval [CI] = 1.698 to 10.278; P = 0.002) was the only independent predictor for mortality in the multivariate analysis. Conclusion This report provides baseline data for future

  14. Epidemiology of candidemia and antifungal susceptibility in invasive Candida species in the Asia-Pacific region.

    Science.gov (United States)

    Wang, He; Xu, Ying-Chun; Hsueh, Po-Ren

    2016-10-01

    In the Asia-Pacific region, Candida albicans is the predominant Candida species causing invasive candidiasis/candidemia in Australia, Japan, Korea, Hong Kong, Malaysia, Singapore and Thailand whereas C. tropicalis is the most frequently encountered Candida species in Pakistan and India. Invasive isolates of C. albicans, C. parapsilosis complex and C. tropicalis remain highly susceptible to fluconazole (>90% susceptible). Fluconazole resistance (6.8-15%), isolates with the non-wild-type phenotype for itraconazole susceptibility (3.9-10%) and voriconazole (5-17.8%), and echinocandin resistance (2.1-2.2% in anidulafungin and 2.2% in micafungin) among invasive C. glabrata complex isolates are increasing in prevalence. Moreover, not all isolates of C. tropicalis have been shown to be susceptible to fluconazole (nonsusceptible rate, 5.7-11.6% in China) or voriconazole (nonsusceptible rate, 5.7-9.6% in China).

  15. Susceptibility to antifungal agents of Candida spp. from blood and feces collected in Novi Sad in 3-year period (2008-2010

    Directory of Open Access Journals (Sweden)

    Jelesić Zora Z.

    2011-01-01

    Full Text Available Candidemia is an important emerging nosocomial infection in patients with risk factors. Candida species from nonsterile sites can give insight into the characteristics of strains that may cause invasive disease. The aim of this study was to evaluate antifungal susceptibility of Candida blood and fecal isolates in Novi Sad, Vojvodina. During a 3-year period (2008 to 2010, 424 isolates of Candida spp. were collected, 30 bloodstream isolates and 394 strains from fecal samples. In vitro susceptibility of these isolates to five antifungal agents was established using commercial ATB FUNGUS 3 (Bio-Mérieux. Predominant species was Candida albicans (6 isolates from blood and 269 from feces. Resistance to one or more antifungal agents was less common in Candida albicans (3.63% than in other species (24.83%. Resistance to itraconazole was the most commonly found in both groups of isolates, 9.64% strains from feces and 20% from blood samples. Twelve isolates were multiply resistant, usually to fluconazole, itraconazole, and voriconazole. Resistance to amphotericine B was extremely rare. Although resistance to antimycotics of Candida spp. is rare at present, continued surveillance of antifungal susceptibility is necessary in order to monitor trends, and to choose the right empiric therapy.

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

    Science.gov (United States)

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

    2018-01-01

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

  17. Red Regional de Laboratorios para la Vigilancia de las Infecciones Fúngicas Invasoras y Susceptibilidad a los Antifúngicos Regional Laboratory Network for Surveillance of Invasive Fungal Infections and Antifungal Susceptibility in Latin America

    Directory of Open Access Journals (Sweden)

    Manuel Cuenca-Estrella

    2008-02-01

    Full Text Available 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.

  18. Perfil de suscetibilidade a antifúngicos de dermatófitos isolados de pacientes com insuficiência renal crônica Antifungal susceptibility of dermatophytes isolated from patients with chronic renal failure

    Directory of Open Access Journals (Sweden)

    Cibele Massotti Magagnin

    2011-08-01

    . Treatment requires the use of topical and/or systemic antifungal drugs. The efficacy of antifungal agents for the treatment of dermatophytosis has yet to be evaluated. Studies evaluating the in vitro activity of antifungal agents are rare, particularly in filamentous fungi. OBJECTIVE: To evaluate the susceptibility profile of different species of dermatophytes isolated from patients with chronic renal failure to nine antifungal drugs available on the market for the treatment of dermatophytosis. METHODS: Twenty-six isolates of dermatophytes obtained from patients with chronic renal failure were analyzed with respect to their susceptibility to nine antifungal agents (ketoconazole, ciclopirox olamine, fluconazole, griseofulvin, itraconazole, miconazole, piroctone olamine, terbinafine and tioconazole, using the broth microdilution method proposed by the Clinical and Laboratory Standards Institute (CLSI and adapted for dermatophytes. RESULTS: Of the antifungal agents tested, the best results in terms of sensitivity were found with terbinafine and tioconazole, while the antifungal activity of fluconazole was found to be weak, particularly against strains of M. gypseum. Ciclopirox olamine, although less effective than terbinafine, also yielded satisfactory results. CONCLUSIONS: In general, the sensitivity profile of the antifungal agents tested in this study was similar to results obtained in previous studies, confirming the need to determine which species is causing the dermatophytosis given that antifungal susceptibility varies from one species to another. Furthermore, the present findings show the importance of conducting in vitro sensitivity tests, since the sensitivity profile may differ among isolates of the same species

  19. Madurella mycetomatis is not susceptible to the echinocandin class of antifungal agents

    NARCIS (Netherlands)

    W.W.J. van de Sande (Wendy); A.H. Fahal (Ahmed); I.A.J.M. Bakker-Woudenberg (Irma); A.F. van Belkum (Alex)

    2010-01-01

    textabstractEumycetoma caused by Madurella mycetomatis is treated surgically and with high doses of ketoconazole. Therapeutic responses are poor, and recurrent infections are common. In search of therapeutic alternatives in the treatment of mycetoma, we determined the in vitro susceptibilities of M.

  20. E Test: a novel technique for antimicrobial susceptibility testing

    Directory of Open Access Journals (Sweden)

    Helio Silva Sader

    Full Text Available We describe the applicability of the E test (AB Biodisk Solna, Sweden, a new method for determining minimum inhibitory concentrations of antimicrobial agents against bacteria. This report is based on the literature review and on our own experience using the E test for susceptibility testing of the Xanthomonas maltophilia, Streptococcus pneumoniae and Streptococcus viridans group against eight different drugs.

  1. Decreased susceptibility of Candida albicans to azole antifungals: a complication of long-term treatment in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) patients.

    Science.gov (United States)

    Rautemaa, Riina; Richardson, Malcolm; Pfaller, Michael; Koukila-Kähkölä, Pirkko; Perheentupa, Jaakko; Saxén, Harri

    2007-10-01

    Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, APS1) is an autosomal recessive disease exceptionally common in Finland. Most patients have chronic oral candidiasis from early childhood and this infection has been shown to be carcinogenic. Hence, patients receive repeated treatment and prophylactic courses of antifungals throughout life. In Finland, 92 patients have been diagnosed with APECED and 66 of them are currently alive. Our aim was to study the effect of long-term azole treatment on the candidal colonization of APECED patients and the influence on antifungal susceptibilities. We evaluated the culture reports from 1994 to 2004 of 56 APECED patients followed in Helsinki University Central Hospital. Candida albicans strains of all 11 patients initially reported resistant (n = 27) and 12 patients reported susceptible (n = 16) to fluconazole were re-analysed for their susceptibility to fluconazole. Antifungal usage was analysed up to 30 years back. A total of 162 fungal cultures had been performed. Of these, 75% had been reported positive for Candida and 63% for C. albicans. Eleven patients (31.4%) had been reported to harbour at least once a C. albicans strain resistant to fluconazole. Re-analysis of the stored C. albicans strains originally reported to be resistant to fluconazole revealed a mean MIC of 19.5 mg/L. Multiple courses (>6) of fluconazole annually and low dose prophylaxis are major risk factors for persistent colonization with C. albicans with decreased susceptibility in APECED patients.

  2. [Multicenter Prospective Observational Study of Fungal Keratitis--Identification and Susceptibility Test of Fungi].

    Science.gov (United States)

    Sunada, Atsuko; Asari, Seishi; Inoue, Yoshitsugu; Ohashi, Yuichi; Suzuki, Takashi; Shimomura, Yoshikazu; Fukuda, Masahiko; Sotozono, Chie; Hatano, Hiroshi; Eguchi, Hiroshi; Araki-Sasaki, Kaoru; Hoshi, Saichi; Yaguchi, Takashi; Makimura, Koichi; Yokokura, Shunji; Mochizuki, Kiyofumi; Monden, Yu; Nejima, Ryohei

    2016-01-01

    To investigate the causative fungi of fungal keratitis in Japan and their drug susceptibility. Identification and antifungal susceptibility test for 8 drugs (micafungin, amphotericin B, flucytosine, fluconazole, itraconazole, voriconazole, miconazole and pimaricin) were performed using isolated fungi from patients with fungal keratitis treated at 27 facilities in Japan between November 1, 2011 and October 31, 2013. Fungal strains were detected in 72 (50.7%) out of 142 samples. The major isolates were Fusarium spp. (18), Candida parapsilosis (12), C. albicans (11) and Alternaria spp. (6), in all, fungi of 31 species were identified by gene analysis. In the yeast-like fungi, susceptibility rates were evident for more than 80% in voriconazole, pimaricin, flucytosine, micafungin, amphotericin B and fluconazole. In filamentous fungi, the susceptibility rate was less than 50% except for PMR (90%). Fusarium spp., which were susceptible to amphotericin B and pimaricin, showed lower susceptibility rates compared with other genera. Although various genera and species of fungi cause fungal keratitis, the obtained drug susceptibility data in this study demonstrates the different susceptibility patterns among the major isolates (Fusarium spp., C. parapsilosis, C. albicans and other groups). This is important evidence useful for fungal keratitis treatment.

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

    OpenAIRE

    OLIVEIRA, Daniele Carvalho; de LORETO, ?rico Silva; MARIO, D?bora 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 d...

  4. Comparative antifungal susceptibility analysis of Candida albicans versus non-albicans Candida corneal isolates.

    Science.gov (United States)

    Spierer, Oriel; Dugar, Jyoti; Miller, Darlene; OʼBrien, Terrence P

    2015-05-01

    To compare the in vitro activity of topical amphotericin B (AMB), natamycin, voriconazole, and fluconazole against human corneal isolates of Candida sp. for guidance in the treatment of Candida keratitis. Sixty-eight Candida isolates (37 albicans and 31 non-albicans isolates) recovered from corneal scrapings submitted to rule out microbial keratitis, during the years 2005 to 2011, at the Bascom Palmer Eye Institute, were examined in this study. Corneal isolates were cultured on fungal agars for 48 hours. Each yeast isolate was dispensed into 4 microtiter wells, each containing 100 mL of commercial (natamycin 5%) or compounded (AMB 0.15%, voriconazole 1%, and fluconazole 0.2%) antifungal medications. A comparison of growth patterns was conducted. One hundred percent of the samples showed growth inhibition after treatment exposure with AMB or natamycin. The isolates treated with voriconazole demonstrated an 85% inhibition rate overall, with the Candida albicans samples showing a 77% inhibition rate and the non-albicans sp. a 93% inhibition rate. In the fluconazole group, there was only a 19.6% inhibition rate noted, with a 7.7% inhibition rate observed in the C. albicans group versus a 30% inhibition rate in the non-albicans group. AMB 0.2% and natamycin 5% have equal effectiveness and full inhibition against Candida keratitis isolates. Fluconazole 0.2% is not the drug of choice in both C. albicans and non-albicans keratitis. Voriconazole 1% may need a stronger concentration for higher effectiveness, but potentially may be helpful as a second agent in the treatment of Candida keratitis.

  5. The Aspergillus fumigatus farnesyltransferase β-subunit, RamA, mediates growth, virulence, and antifungal susceptibility

    Science.gov (United States)

    Norton, Tiffany S.; Al Abdallah, Qusai; Hill, Amy M.; Lovingood, Rachel V.; Fortwendel, Jarrod R.

    2017-01-01

    ABSTRACT Post-translational prenylation mechanisms, including farnesylation and geranylgeranylation, mediate both subcellular localization and protein-protein interaction in eukaryotes. The prenyltransferase complex is an αβ heterodimer in which the essential α-subunit is common to both the farnesyltransferase and the geranylgeranyltransferase type-I enzymes. The β-subunit is unique to each enzyme. Farnesyltransferase activity is an important mediator of protein localization and subsequent signaling for multiple proteins, including Ras GTPases. Here, we examined the importance of protein farnesylation in the opportunistic fungal pathogen Aspergillus fumigatus through generation of a mutant lacking the farnesyltransferase β-subunit, ramA. Although farnesyltransferase activity was found to be non-essential in A. fumigatus, diminished hyphal outgrowth, delayed polarization kinetics, decreased conidial viability, and irregular distribution of nuclei during polarized growth were noted upon ramA deletion (ΔramA). Although predicted to be a target of the farnesyltransferase enzyme complex, we found that localization of the major A. fumigatus Ras GTPase protein, RasA, was only partially regulated by farnesyltransferase activity. Furthermore, the farnesyltransferase-deficient mutant exhibited attenuated virulence in a murine model of invasive aspergillosis, characterized by decreased tissue invasion and development of large, swollen hyphae in vivo. However, loss of ramA also led to a Cyp51A/B-independent increase in resistance to triazole antifungal drugs. Our findings indicate that protein farnesylation underpins multiple cellular processes in A. fumigatus, likely due to the large body of proteins affected by ramA deletion. PMID:28489963

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

    Directory of Open Access Journals (Sweden)

    Thaís Pereira de Mello

    2016-01-01

    Full Text Available 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.

  7. Cryptococcus neoformans and C. gattii isolates from both HIV-infected and uninfected patients: antifungal susceptibility and outcome of cryptococcal disease

    Directory of Open Access Journals (Sweden)

    Erika Nascimento

    Full Text Available ABSTRACT One of the factors causing treatment failure in cryptococcosis is the resistance of Cryptococcus spp. to antifungal drugs, which has motivated the susceptibility assessment of isolates from patients with cryptococcosis, different clinical conditions and infections outcomes. Clinical isolates of Cryptococcus spp. from three different groups of patients were studied in the present investigation: 19 HIV-positive patients with relapsing and/or refractory meningitis (Group 1, 30 HIV-positive patients who experienced a single and limited episode of cryptococcosis (Group 2, and 19 HIV-negative patients with cryptococcosis (Group 3. Eighty C. neoformans var. grubii isolates and 7 C. gattii isolates were studied. The minimum inhibitory concentration (MIC of amphotericin B, azole drugs and flucytosine was determined for Cryptococcus spp. by broth microdilution test and E-test. The MIC50 and MIC90 were 0.25 and 0.50 µg/mL for amphotericin B, 4.0 and 8.0 µg /mL for fluconazole, 0.06 and 0.25 µg/mL for itraconazole, 0.25 and 0.50 µg/mL for voriconazole, and 8.0 and 16.0 µg/mL for flucytosine, respectively. Amphotericin B and itraconazole showed higher MICs for C. neoformans var. grubii and C. gattii, respectively. The MICs of fluconazole and itraconazole obtained with the E-test were higher than those obtained with broth microdilution. Isolates from non-HIV coinfected were less sensitive to the azoles. There was no difference in the susceptibility of C. neoformans var. grubii isolates from patients with a favorable or unfavorable outcome or along the episodes of relapsing and/or refractory meningitis.

  8. Prevalencia de candidiasis vaginal en embarazadas: Identificación de levaduras y sensibilidad a los antifúngicos Prevalence of vaginal candidiasis in pregnant women: Identification of yeasts and susceptibility to antifungal agents

    Directory of Open Access Journals (Sweden)

    M. García Heredia

    2006-03-01

    Full Text Available La mujer embarazada es más susceptible tanto a la colonización como a la infección vaginal por levaduras. El objetivo de este trabajo fue determinar la prevalencia de levaduras aisladas de exudados vaginales de mujeres embarazadas y evaluar la sensibilidad a los antifúngicos de uso frecuente. Se estudiaron 493 pacientes en el período comprendido desde diciembre de 1998 hasta febrero de 2000. La prevalencia de Candida spp. fue 28% (Candida albicans 90,4%, Candida glabrata 6,3%, Candida parapsilosis 1,1%, Candida kefyr 1,1%, especies no identificadas 1,1%. Se determinó la sensibilidad a fluconazol, ketoconazol, itraconazol y nistatina por el método de difusión en agar Shadomy. Todos los aislamientos de C. albicans, C. kefyr y C. parapsilosis fueron sensibles in vitro a los antifúngicos probados, mientras que 1 de 6 aislamientos de C. glabrata presentó resistencia extendida a todos los azoles, pero sensibilidad a nistatina. En mujeres embarazadas C. albicans fue la levadura más frecuentemente aislada de exudados vaginales y continúa siendo ampliamente sensible a los antifúngicos; sólo en C. glabrata se observó resistencia a los azoles. Se recomienda la identificación de la levadura a nivel de especie particularmente en el caso de falla terapéutica y en infecciones recidivantes o crónicas.Pregnant women are more susceptible to both vaginal colonization and infection by yeast. Our objectives were to determine the prevalence in pregnant women of yeasts isolated from vaginal exudates and their susceptibility to current antifungal drugs. A total of 493 patients was studied between December 1998 and February 2000. The prevalence of Candida spp. was 28% (Candida albicans 90.4%; Candida glabrata 6.3%; Candida parapsilosis 1.1%, Candida kefyr 1.1%; unidentified species 1.1%. The diffusion test in Shadomy agar was employed to determine the susceptibility to fluconazole, ketoconazole, itraconazole and nistatine. All C. albicans, C. kefyr and

  9. In vitro antifungal activity of topical and systemic antifungal drugs against Malassezia species.

    Science.gov (United States)

    Carrillo-Muñoz, Alfonso Javier; Rojas, Florencia; Tur-Tur, Cristina; de Los Ángeles Sosa, María; Diez, Gustavo Ortiz; Espada, Carmen Martín; Payá, María Jesús; Giusiano, Gustavo

    2013-09-01

    The strict nutritional requirements of Malassezia species make it difficult to test the antifungal susceptibility. Treatments of the chronic and recurrent infections associated with Malassezia spp. are usually ineffective. The objective of this study was to obtain in vitro susceptibility profile of 76 clinical isolates of Malassezia species against 16 antifungal drugs used for topical or systemic treatment. Isolates were identified by restriction fragment length polymorphism. Minimal inhibitory concentrations (MIC) were obtained by a modified microdilution method based on the Clinical Laboratory Standards Institute reference document M27-A3. The modifications allowed a good growth of all tested species. High in vitro antifungal activity of most tested drugs was observed, especially triazole derivatives, except for fluconazole which presented the highest MICs and widest range of concentrations. Ketoconazole and itraconazole demonstrated a great activity. Higher MICs values were obtained with Malassezia furfur indicating a low susceptibility to most of the antifungal agents tested. Malassezia sympodialis and Malassezia pachydermatis were found to be more-susceptible species than M. furfur, Malassezia globosa, Malassezia slooffiae and Malassezia restricta. Topical substances were also active but provide higher MICs than the compounds for systemic use. The differences observed in the antifungals activity and interspecies variability demonstrated the importance to studying the susceptibility profile of each species to obtain reliable information for defining an effective treatment regimen. © 2013 Blackwell Verlag GmbH.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Daniele Carvalho OLIVEIRA

    2015-08-01

    Full Text Available 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.

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

    Science.gov (United States)

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

    2017-04-01

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

  13. Molecular epidemiology and antifungal susceptibility of Saprochaete capitata (Blastoschizomyces capitatus) isolates causing nosocomial infection in Kayseri/Turkey.

    Science.gov (United States)

    Koç, A Nedret; Atalay, M Altay; Timur, Demet; Demir, Gonca; Kaynar, Leylagül

    2016-08-01

    Saprochaete capitata isolates have emerged as important nosocomial pathogens, among immunosuppressed or neutropenic patients, and a rare cause of nosocomial infection in the hematology-bone marrow unit (HBMU) and the intensive care unit (ICU). The purpose of this study was to molecular epidemiology and antifungal susceptibility of S. capitata (Blastoschizomyces capitatus) isolates causing nosocomial infection at Kayseri in Turkey. During a period from 2012 to 2015, a total of 20 S. capitata strains were obtained from patients hospitalized at Erciyes University Hospital. The identification of S. capitata was performed by phenotypic and biochemical methods; this was confirmed by molecular methods by DNA sequencing analysis. Genotyping of S.capitata isolates from different patients was determined to by the repetitive sequence PCR (repPCR) using the DiversiLab System (BioMerieux). More than half of the patients with S. capitata infections were hospitalized in the hematology-oncology unit (60%). The patients mainly included those using intravascular devices (90%), and receiving parenteral antibiotics (85%); the mortality rate was 55%. The microbiological investigation failed to identify S. capitata in the hospital environment. All isolates were resistant to caspofungin (>32). However, the MIC90 values for voriconazole, amphotericin B, and fluconazole against all of the isolates were 0.125, 0.25, and 1μg/ml, respectively. The S. capitata strains belonged to five clones (A-E) which were determined by the use of rep-PCR and Clone C was found to be predominant. S. capitata isolates are an important cause of nosocomial infection in the HBMU and ICUs.

  14. Identificação molecular e suscetibilidade antifúngica de Candida parapsilosis isoladas no Ceará, Brasil Molecular identification and antifungal susceptibility of Candida parapsilosis isolates in Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    Everardo Albuquerque Menezes

    2012-12-01

    Full Text Available INTRODUÇÃO: Candida parapsilosis é a segunda ou terceira levedura mais isolada de hemoculturas em várias partes do mundo. É um patógeno comumente isolado no Brasil e no Ceará. Apresenta capacidade de formar biofilmes em cateteres e outros dispositivos médicos e esses fatores contribuem para a disseminação dessa levedura. OBJETIVOS: Identificar e avaliar a suscetibilidade aos antifúngicos de C. parapsilosis isoladas de amostras de sangue e urina de pacientes atendidos em hospitais no Ceará. MÉTODOS: Foram isoladas e identificadas 57 cepas de C. parapsilosis. As cepas foram identificadas por testes fenotípicos e moleculares. A suscetibilidade foi avaliada pelo método de microdiluição em caldo (protocolo do Clinical and Laboratory Standards Institute [CLSI] M27-A3. Foram avaliados cinco antifúngicos (anfotericina B, caspofungina, fluconazol, itraconazol e voriconazol. RESULTADOS E CONCLUSÃO: As cepas foram identificadas como C. parapsilosis por testes fenotípicos e confirmadas pelos testes moleculares. Quanto ao perfil de sensibilidade, elas se mostraram sensíveis aos antifúngicos testados, sendo a resistência ainda um fenômeno raro entre cepas de C. parapsilosis isoladas no Ceará.INTRODUCTION: C. parapsilosis is the second or third most isolated yeast from blood cultures in various parts of the world. It is a commonly isolated pathogen in Brazil and Ceará. C. parapsilosis is liable to form biofilms on catheters and other medical devices, which contributes to the spread of this yeast. OBJECTIVE: The objective of this study was to identify and assess the antifungal susceptibility of C. parapsilosis isolates from blood and urine samples collected from patients in hospitals in Ceará. METHODS: We isolated and identified 57 strains of C. parapsilosis. The strains were identified by phenotypic and molecular tests. The susceptibility to antifungals was assessed by broth microdilution (Clinical and Laboratory Standards Institute

  15. Drug susceptibility testing of Mycobacterium tuberculosis to fluoroquinolones

    DEFF Research Database (Denmark)

    Johansen, I S; Larsen, A R; Sandven, P

    2003-01-01

    In the first attempt to establish a quality assurance programme for susceptibility testing of Mycobacterium tuberculosis to fluoroquinolones, 20 strains with different fluoroquinolone susceptibility patterns were distributed by the Supranational Reference Laboratory in Stockholm to the other...

  16. Alternative testing strategies for predicting developmental toxicity of antifungal compound

    NARCIS (Netherlands)

    Li, H.

    2016-01-01

    Determination of safe human exposure levels of chemicals in toxicological risk assessments largely relies on animal toxicity data. In these toxicity studies, the highest number of animals are used for reproductive and developmental toxicity testing. Because of economic and ethical reasons, there

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-03-01

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

  19. Evaluation of Malassezia pachydermatis antifungal susceptibility using two different methods Avaliação da sensibilidade da Malassezia pachydermatis frente a antifúngicos através de duas técnicas

    Directory of Open Access Journals (Sweden)

    Patrícia da Silva Nascente

    2003-12-01

    Full Text Available Malassezia pachydermatis is recognized as a normal inhabitant and an opportunistic pathogen of the external ear canal and skin of dogs and cats. In especial clinical conditions, and mainly in the cases of therapeutic failure related to external otitis and dermatitis complicated by this yeast, it is recommended test susceptibility to antifungal drugs. The purpose of this work was to evaluate the susceptibility of 44 isolates of M. pachydermatis from the external ear canal and skin of dogs and cats using two different in vitro antifungal susceptibility methods: the Etest® and the broth microdilution method. Thirty-five samples were tested using the Etest®, twenty-four samples were tested using the broth microdilution method and fifteen samples were tested using both tests. The antifungal agents used were ketoconazole (KTZ, fluconazole (FLZ and itraconazole (ITZ. In the broth microdilution method the yeast was less susceptible to ITZ while KTZ had the strongest activity. On the other hand, the Etest® showed that M. pachydermatis was more susceptible to ITZ while the less active drug was FLZ. The simultaneous evaluation using both methods identified FLZ as the antifungal drug with the highest activity (64.3%, followed by KTZ (57.1% and ITZ (28.6%. These results showed that there is an urgent need to standardize of the values considered as parameters for growth inhibition of this yeast so a simple and efficient method can be used routinely in the laboratory practice.Malassezia pachydermatis é considerada um habitante normal e patógeno oportunista do meato acústico externo e tegumento cutâneo de cães e gatos. Em condições clínicas especiais e nos casos de fracasso terapêutico, comum em casos de otite externa ou dermatite complicadas por esta levedura, é recomendado testar a sensibilidade aos antifúngicos. O objetivo do trabalho foi avaliar a sensibilidade de 44 isolados de M. pachydermatis do meato acústico externo e do tegumento cut

  20. Minimal inhibitory concentration distributions and epidemiological cutoff values of five antifungal agents against Sporothrix brasiliensis

    OpenAIRE

    Almeida-Paes, Rodrigo; Brito-Santos, Fábio; Figueiredo-Carvalho, Maria Helena Galdino; Machado, Ana Caroline Sá; Oliveira, Manoel Marques Evangelista; Pereira, Sandro Antonio; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria

    2017-01-01

    BACKGROUND Sporothrix brasiliensis is the most virulent sporotrichosis agent. This species usually responds to antifungal drugs, but therapeutic failure can occur in some patients. Antifungal susceptibility tests have been performed on this species, but no clinical breakpoints (CBPs) are available. In this situation, minimal inhibitory concentration (MIC) distributions and epidemiological cutoff values (ECVs) support the detection of identification of resistant strains. OBJECTIVES To study ...

  1. Invitro antifungal susceptibilities of Candida species to liposomal amphotericin B, determined using CLSI broth microdilution, and amphotericin B deoxycholate, measured using the Etest.

    Science.gov (United States)

    Lovero, Grazia; De Giglio, Osvalda; Rutigliano, Serafina; Diella, Giusy; Caggiano, Giuseppina; Montagna, Maria Teresa

    2017-03-01

    The antifungal susceptibilities of 598 isolates of Candida spp. (bloodstream and other sterile sites) to liposomal amphotericin B (L-AmB) versus amphotericin B (AmB) were determined. MICs were calculated using the Clinical and Laboratory Standards Institute broth microdilution (M27-A3) method for L-AmB and the Etest method for AmB. The MIC50/MIC90 (µg ml-1) values for L-AmB broth microdilution and AmB Etest were 0.25/1 and 0.19/0.5, respectively. The overall essential agreement (±2 dilutions) was 91.5 %, ranging from 37.5 % (Candida lusitaniae) to 100 % (Candida glabrata and Candida krusei). Categorical agreement between the two methods was categorized based on a previously published breakpoint (susceptible/resistant MIC cut-off of 1 µg ml-1). The overall categorical agreement at the 48 h reading was 97.3 %, ranging from 72.7 % (C. krusei) to 100 % (Candida albicans). Major and very major discrepancies occurred in 2.3 and 0.3 %, respectively. Spearman's ρ was 0.48 (PCandida spp. to L-AmB and thus to support its use in antifungal treatment.

  2. Usefulness of Routine Antibacterial Susceptibility Testing Results for ...

    African Journals Online (AJOL)

    The objective was to evaluate the usefulness and reliability of routine antibacterial susceptibility testing data in antibacterial resistance surveillance in Lagos Metropolis. The antibacterial susceptibility testing results of 3,961 clinical isolates of bacteria from four highly rated hospitals in Lagos metropolis were collated and ...

  3. Caspofungin Etest susceptibility testing of Candida species

    DEFF Research Database (Denmark)

    Arendrup, Maiken Cavling; Pfaller, Michael A; Rosenvinge, Flemming Schønning

    2012-01-01

    The purpose of this study was to evaluate the performance of caspofungin Etest and the recently revised CLSI breakpoints. A total of 497 blood isolates, of which 496 were wild-type isolates, were included. A total of 65/496 susceptible isolates (13.1%) were misclassified as intermediate (I) or re...

  4. A prospective survey of Aspergillus spp. in respiratory tract samples: prevalence, clinical impact and antifungal susceptibility

    DEFF Research Database (Denmark)

    Mortensen, K L; Johansen, H K; Fuursted, Kurt

    2011-01-01

    for routine microbiologic investigation were examined for Aspergillus following routine procedures and with extended incubation (5 days). Identification was done by morphologic criteria and susceptibility testing using EUCAST method for azoles and amphotericin B E-test. Invasive aspergillosis (IA......) was evaluated using modified EORTC/MSG criteria. A total of 11,368 airway samples were received. Growth of Aspergillus spp. was found in 129 and 151 patients using routine and extended incubation, respectively. Three patients had proven IA (2%), 11 probable (7%), four had allergic bronchopulmonary aspergillosis...... μg/ml (3/112 A. fumigatus, 1/2 A. terreus). In conclusion, Aspergillus appears to be an important pathogen in Denmark. Elevated itraconazole MICs were detected in 4% of the isolates including a multi-azole resistant isolate....

  5. In vitro susceptibility to antifungal agents of clinical and environmental Cryptococcus neoformans isolated in Southern of Brazil Suscetibilidade in vitro a antifúngicos, de amostras clínicas e ambientais de Cryptococcus neoformans isoladas no sul do Brasil

    Directory of Open Access Journals (Sweden)

    Sydney Hartz ALVES

    2001-10-01

    Full Text Available The purpose of the present study was to compare the susceptibility to four antifungal agents of 69 Cryptococcus neoformans strains isolated from AIDS patients with that of 13 C. neoformans strains isolated from the environment. Based on the NCCLS M27-A methodology the Minimal Inhibitory Concentrations (MICs obtained for amphotericin B, itraconazole and ketoconazole were very similar for clinical and environmental isolates. Clinical isolates were less susceptible to fluconazole than environmental isolates. The significance of these findings and aspects concerning the importance, role and difficulties of C. neoformans susceptibility testing are also discussed.Comparou-se a suscetibilidade de 69 amostras de C. neoformans isoladas de pacientes com SIDA com 13 amostras de C. neoformans isoladas do meio ambiente, frente a quatro agentes antifúngicos. Com base na metodologia preconizada pelo NCCLS (M27-A as concentrações inibitórias mínimas (CIMs obtidas para a anfotericina B, itraconazol e cetoconazol foram muito semelhantes nos dois grupos estudados. Todavia, frente ao fluconazol, os isolados clínicos evidenciaram menor sensibilidade do que os provenientes do meio ambiente. Alguns aspectos envolvendo a importância e dificuldades dos testes de suscetibilidade com Cryptococcus neoformans são também discutidos pelos autores.

  6. Antimicrobial resistance and susceptibility testing of anaerobic bacteria.

    Science.gov (United States)

    Schuetz, Audrey N

    2014-09-01

    Infections due to anaerobic bacteria can be severe and life-threatening. Susceptibility testing of anaerobes is not frequently performed in laboratories, but such testing is important to direct appropriate therapy. Anaerobic resistance is increasing globally, and resistance trends vary by geographic region. An overview of a variety of susceptibility testing methods for anaerobes is provided, and the advantages and disadvantages of each method are reviewed. Specific clinical situations warranting anaerobic susceptibility testing are discussed. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Identification, isolation and in vitro antimicrobial susceptibility testing ...

    African Journals Online (AJOL)

    Identification, isolation and in vitro antimicrobial susceptibility testing of Aeromonas veronii associated with an acute death of Channel Catfish (Ictalurus lunetas) in China. X Huang, K Wang, D Zong-Jun, Y Geng, Y Deng ...

  8. Personalized Genetic Testing and Norovirus Susceptibility

    Directory of Open Access Journals (Sweden)

    Natalie Prystajecky

    2014-01-01

    Full Text Available BACKGROUND: The availability of direct-to-consumer personalized genetic testing has enabled the public to access and interpret their own genetic information. Various genetic traits can be determined including resistance to norovirus through a nonsense mutation (G428A in the FUT2 gene. Although this trait is believed to confer resistance to the most dominant norovirus genotype (GII.4, the spectrum of resistance to other norovirus strains is unknown. The present report describes a cluster of symptomatic norovirus GI.6 infection in a family identified to have norovirus resistance through personalized genetic testing.

  9. Rapid susceptibility testing and microcolony analysis of Candida spp. cultured and imaged on porous aluminum oxide.

    Directory of Open Access Journals (Sweden)

    Colin J Ingham

    Full Text Available BACKGROUND: Acquired resistance to antifungal agents now supports the introduction of susceptibility testing for species-drug combinations for which this was previously thought unnecessary. For pathogenic yeasts, conventional phenotypic testing needs at least 24 h. Culture on a porous aluminum oxide (PAO support combined with microscopy offers a route to more rapid results. METHODS: Microcolonies of Candida species grown on PAO were stained with the fluorogenic dyes Fun-1 and Calcofluor White and then imaged by fluorescence microscopy. Images were captured by a charge-coupled device camera and processed by publicly available software. By this method, the growth of yeasts could be detected and quantified within 2 h. Microcolony imaging was then used to assess the susceptibility of the yeasts to amphotericin B, anidulafungin and caspofungin (3.5 h culture, and voriconazole and itraconazole (7 h culture. SIGNIFICANCE: Overall, the results showed good agreement with EUCAST (86.5% agreement; n = 170 and E-test (85.9% agreement; n = 170. The closest agreement to standard tests was found when testing susceptibility to amphotericin B and echinocandins (88.2 to 91.2% and the least good for the triazoles (79.4 to 82.4%. Furthermore, large datasets on population variation could be rapidly obtained. An analysis of microcolonies revealed subtle effects of antimycotics on resistant strains and below the MIC of sensitive strains, particularly an increase in population heterogeneity and cell density-dependent effects of triazoles. Additionally, the method could be adapted to strain identification via germ tube extension. We suggest PAO culture is a rapid and versatile method that may be usefully adapted to clinical mycology and has research applications.

  10. [Antimicrobial susceptibility testing of anaerobic bacteria].

    Science.gov (United States)

    García-Sánchez, José E; García-Sánchez, Enrique; García-García, María Inmaculada

    2014-02-01

    The anaerobic bacteria resistance to antibiotics is increasing, and even has appeared against the most active of those, like metronidazol and carbapenems. This fact forces to make and periodical sensibility tests -at least in the most aggressive and virulent species, in cases that they are isolated from life locations and in the absence of therapeutic response- to check the local sensibility and to establish suitable empiric therapies, all based on multicentric studies carried out in order to this or well to check the activity of new antibiotics. For the laboratory routine, the easiest sensibility method is the E-test/MIC evaluator. Another alternative is microdilution, that's only normalized for Bacteroides. There are preliminary facts that allow the use of disc diffusion method in some species of Bacteroides and Clostridium. For the temporal and multicentric studies, the procedure is dilution in agar plate, the reference method. Copyright © 2014 Elsevier España, S.L. All rights reserved.

  11. Antimicrobial resistance in campylobacter: susceptibility testing methods and resistance trends.

    Science.gov (United States)

    Ge, Beilei; Wang, Fei; Sjölund-Karlsson, Maria; McDermott, Patrick F

    2013-10-01

    Most Campylobacter infections are self-limiting but antimicrobial treatment (e.g., macrolides, fluoroquinolones) is necessary in severe or prolonged cases. Susceptibility testing continues to play a critical role in guiding therapy and epidemiological monitoring of resistance. The methods of choice for Campylobacter recommended by the Clinical and Laboratory Standards Institute (CLSI) are agar dilution and broth microdilution, while a disk diffusion method was recently standardized by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Macrolides, quinolones, and tetracyclines are among the common antimicrobials recommended for testing. Molecular determination of Campylobacter resistance via DNA sequencing or PCR-based methods has been performed. High levels of resistance to tetracycline and ciprofloxacin are frequently reported by many national surveillance programs, but resistance to erythromycin and gentamicin in Campylobacter jejuni remains low. Nonetheless, variations in susceptibility observed over time underscore the need for continued public health monitoring of Campylobacter resistance from humans, animals, and food. Published by Elsevier B.V.

  12. Susceptibility testing of fish cell lines for virus isolation

    DEFF Research Database (Denmark)

    Ariel, Ellen; Skall, Helle Frank; Olesen, Niels Jørgen

    2009-01-01

    compare susceptibility between cell lines and between lineages within a laboratory and between laboratories (Inter-laboratory Proficiency Test). The objective being that the most sensitive cell line and lineages are routinely selected for diagnostic purposes.In comparing cell lines, we simulated "non......-cell-culture-adapted" virus by propagating the virus in heterologous cell lines to the one tested. A stock of test virus was produced and stored at - 80 °C and tests were conducted biannually. This procedure becomes complicated when several cell lines are in use and does not account for variation among lineages. In comparing...... cell lineages, we increased the number of isolates of each virus, propagated stocks in a given cell line and tested all lineages of that line in use in the laboratory. Testing of relative cell line susceptibility between laboratories is carried out annually via the Inter-laboratory Proficiency Test...

  13. In Vitro-Clinical Correlations for Amphotericin B Susceptibility in AIDS-Associated Cryptococcal Meningitis▿ †

    Science.gov (United States)

    Larsen, R. A.; Bauer, M.; Brouwer, A. E.; Sanchez, A.; Thomas, A. M.; Rajanuwong, A.; Chierakul, W.; Peacock, S. J.; Day, N.; White, N. J.; Rinaldi, M. G.; Harrison, T. S.

    2007-01-01

    Reliable measures of antifungal drug susceptibility are needed. We tested the susceptibility of Cryptococcus neoformans from patients treated with amphotericin B. In vitro susceptibility employed a modified broth macrodilution method. We demonstrate a strong correlation between the quantitative measures of in vitro amphotericin B susceptibility and the quantitative response observed in patients. PMID:17060519

  14. In Vitro Susceptibility Test of Different Clinical Isolates against Ceftriaxone

    Directory of Open Access Journals (Sweden)

    Syed Hakim Masood

    2010-06-01

    Full Text Available Objectives: Because of the prevailing penicillin resistance in microorganisms, broad spectrum cephalosporins are used empirically specially in developing countries. The aim of this study is to determine the susceptibility pattern of different gram positive and gram negative pathogens against third generation cephalosporin-ceftriaxone to explore the existing effectiveness of this antibiotic.Methods: 180 clinical isolates of different gram positive and gram negative pathogens including P.mirabilis, S. typhi P.aeruginosa, E. coli, S. aureus and Klebsiella were collected from blood and urine samples of in-patients. 30 isolates of all species were tested against each of six brands of ceftriaxone using in vitro sensitivity tests by disc diffusion method (NCCLS criteria. The susceptibility limit was ≥21 mm zone of inhibition, while moderately susceptible was considered at 20-14 mm, and those isolates which showed >13 mm or no zone of inhibition were resistant to this antibacterial drug.Results: Ceftriaxone was found most effective against S. aureus. While 96.1% of the isolates showed susceptibility towards ceftriaxone, followed by E. coli (95%, P. aeruginosa (92.7%, K. pneumonia (89.4% and S. typhi (87.2%. P. mirabilis showed lowest susceptibility amongst all the test organisms (83.8%.Conclusion: Ceftriaxone can be used as a drug of choice in infections caused by S. aureus, E. coli, P. aurigenosa, K. pneumonia and S. typhi. However, it should be used with other antimicrobial agents in order to increase its effectiveness against P. mirabilis.

  15. Antimycobacterial susceptibility testing methods for natural products research

    Directory of Open Access Journals (Sweden)

    Juan Gabriel Bueno Sánchez

    2010-06-01

    Full Text Available The emergence of multidrug-resistant strains of Mycobacterium tuberculosis underscores the need of continuous developments on new and efficient methods to determine the susceptibility of isolates of M. tuberculosis in the search for novel antimicrobial agents. Natural products constitute an important source of new drugs, but design and implementation of antimycobacterial susceptibility testing methods are necessary for evaluate the different extracts and compounds. A number of biological assay methodologies are in current use, ranging from the classical disk diffusion and broth dilution assay format, to radiorespirometric (BACTEC, dye-based, and fluorescent/luminescence reporter assays. This review presents an analysis on the in vitro susceptibility testing methods developed for determinate antitubercular activity in natural products and related compounds (semi-synthetic natural products and natural products-derived compounds and the criteria to select the adequate method for determination of biological activity of new natural products.

  16. Evaluation of the BIOGRAM antimicrobial susceptibility test system.

    OpenAIRE

    D'Amato, R F; Hochstein, L; Vernaleo, J R; Cleri, D J; Wallman, A A; Gradus, M S; Thornsberry, C

    1985-01-01

    BIOGRAM is an antimicrobial susceptibility test system for the determination of MICs from the standard disk diffusion test zone diameters. The system was challenged with 511 recent clinical isolates of members of the family Enterobacteriaceae, nonfermentative gram-negative bacteria, staphylococci, and enterococci. Results were compared with those obtained with the broth microdilution method. Appropriate control organisms were included with each test series. A total of 10,085 organism-drug com...

  17. Antifungal activity of leaf extract of Crassocephalum repidiodes on ...

    African Journals Online (AJOL)

    The susceptibility profile of the dermatophytes tested was T. mentagrophytes. > T. rubrum > M. audouinii. The phytochemical studies of the extracts revealed that the aqueous extract lacked terpenes and anthraquinone while terpenes were absent in ethanolic extract. KEY WORDS: Antifungal, Dermatophytes, Extract, ...

  18. Agar dilution method for susceptibility testing of Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Marta C de Castillo

    1996-12-01

    Full Text Available The antibiotic susceptibilities of Neisseria gonorrhoeae isolates obtained from patients attending a clinic for sexually transmitted diseases in Tucumán, Argentina, were determined by the agar dilution method (MIC. 3.5% of the isolates produced ²-lactamase. A total of 96.5% of ²-lactamase negative isolates tested were susceptible to penicillin (MIC < 2 µgml-1; 14.03% of the tested isolates were resistant to tetracycline (MIC < 2 µgml-1, and 98% of the tested isolates were susceptible to spectinomycin (MIC < 64 µgml-1. The MICs for 95% of the isolates, tested for other drugs were: < 2 µgml-1 for cefoxitin, < 0.06 µgml-1 for cefotaxime, < 0.25 µgml-1 for norfloxacin, < 10 µgml-1 for cephaloridine, < 10 µgml-1 for cephalexin, and < 50 µgml-1 for kanamycin. Antibiotic resistance among N. gonorrhoeae isolates from Tucumán, Argentina, appeared to be primarily limited to penicillin and tetracycline, which has been a general use against gonorrhoeae in Tucumán since 1960. Periodic monitoring of the underlying susceptibility profiles of the N. gonorrhoeae strains prevalent in areas of frequent transmission may provide clues regarding treatment options and emerging of drug resistance.

  19. suitability of vitek 2 system in identification and susceptibility testing

    African Journals Online (AJOL)

    2014-04-01

    Apr 1, 2014 ... errors that would not have had any clinical impact. Conclusion:These data suggest that direct Vitek would provide acceptable identification and antimicrobial susceptibility testing results for Gram-negative bacilli. Compared to the standard method, the direct Vitek method would reduce turnaround time by at.

  20. Antiobiotics susceptibility of Salmonella isolates from Wdal Test ...

    African Journals Online (AJOL)

    Antiobiotics susceptibility of Salmonella isolates from Wdal Test Positive Patients at the Federal Medical Center, Gusau. SB Manga, IG Ameh, S Bashir, AG Muazu, B Danjuma, ML Ibrahim, K Abdullahi, J Mawak. Abstract. No Abstract Supplied. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD ...

  1. Rapid identification and susceptibility testing of Candida spp. from positive blood cultures by combination of direct MALDI-TOF mass spectrometry and direct inoculation of Vitek 2.

    Directory of Open Access Journals (Sweden)

    Evgeny A Idelevich

    Full Text Available Fungaemia is associated with high mortality rates and early appropriate antifungal therapy is essential for patient management. However, classical diagnostic workflow takes up to several days due to the slow growth of yeasts. Therefore, an approach for direct species identification and direct antifungal susceptibility testing (AFST without prior time-consuming sub-culturing of yeasts from positive blood cultures (BCs is urgently needed. Yeast cell pellets prepared using Sepsityper kit were used for direct identification by MALDI-TOF mass spectrometry (MS and for direct inoculation of Vitek 2 AST-YS07 card for AFST. For comparison, MALDI-TOF MS and Vitek 2 testing were performed from yeast subculture. A total of twenty four positive BCs including twelve C. glabrata, nine C. albicans, two C. dubliniensis and one C. krusei isolate were processed. Applying modified thresholds for species identification (score ≥ 1.5 with two identical consecutive propositions, 62.5% of BCs were identified by direct MALDI-TOF MS. AFST results were generated for 72.7% of BCs directly tested by Vitek 2 and for 100% of standardized suspensions from 24 h cultures. Thus, AFST comparison was possible for 70 isolate-antifungal combinations. Essential agreement (minimum inhibitory concentration difference ≤ 1 double dilution step was 88.6%. Very major errors (VMEs (false-susceptibility, major errors (false-resistance and minor errors (false categorization involving intermediate result amounted to 33.3% (of resistant isolates, 1.9% (of susceptible isolates and 1.4% providing 90.0% categorical agreement. All VMEs were due to fluconazole or voriconazole. This direct method saved on average 23.5 h for identification and 15.1 h for AFST, compared to routine procedures. However, performance for azole susceptibility testing was suboptimal and testing from subculture remains indispensable to validate the direct finding.

  2. Genotyping and In Vitro Antifungal Susceptibility Testing of Fusarium Isolates from Onychomycosis in India

    NARCIS (Netherlands)

    Gupta, Chhavi; Jongman, Marit; Das, Shukla; Snehaa, K; Bhattacharya, S N; Seyedmousavi, S; van Diepeningen, Anne D

    Onychomycosis refers to fungal infection of the nail and is commonly caused by dermatophytes, while yeasts and non-dermatophytic molds (NDM) are increasingly recognized as pathogens in nail infections. The present study was done to delineate molecular epidemiology of Fusarium onychomycosis in India.

  3. Genotyping and In Vitro Antifungal Susceptibility Testing of Fusarium Isolates from Onychomycosis in India

    NARCIS (Netherlands)

    Gupta, C.; Jongman, M.; Das, S.; Snehaa, K.; Bhattacharya, S.N.; Seyedmousavi, S.; Diepeningen, A.D. van

    2016-01-01

    Onychomycosis refers to fungal infection of the nail and is commonly caused by dermatophytes, while yeasts and non-dermatophytic molds (NDM) are increasingly recognized as pathogens in nail infections. The present study was done to delineate molecular epidemiology of Fusarium onychomycosis in India.

  4. Antifungal activity of extracts and isolated compounds from Buchenavia tomentosa on Candida albicans and non-albicans.

    Science.gov (United States)

    Teodoro, Guilherme R; Brighenti, Fernanda L; Delbem, Alberto C Botazzo; Delbem, Ádina Cléia B; Khouri, Sonia; Gontijo, Aline Vidal L; Pascoal, Aislan Crf; Salvador, Marcos J; Koga-Ito, Cristiane Y

    2015-01-01

    This study aimed to evaluate the antifungal activity of Buchenavia tomentosa extract and bioactive compounds on six Candida species. The antimicrobial activity of extract was evaluated using standard strains and clinical isolates. Cytotoxicity was tested in order to evaluate cell damage caused by the extract. Extract was chemically characterized and the antifungal activity of its compounds was evaluated. Extract showed antifungal activity on Candida species. Candida non-albicans were more susceptible than Candida albicans. Low cytotoxicity for extract was observed. The isolated compounds presented antifungal activity at least against one Candida spp. and all compounds presented antifungal effect on Candida glabrata. Extracts from Buchenavia tomentosa showed promising antifungal activity on Candida species with low cytotoxicity. Gallic acid, corilagin and ellagic acid showed promising inhibitory activity on Candida glabrata.

  5. Improved method for testing susceptibility of Mycobacterium tuberculosis to pyrazinamide.

    OpenAIRE

    Butler, W R; Kilburn, J O

    1982-01-01

    The acid medium required to test susceptibility of Mycobacterium tuberculosis to pyrazinamide (PZA) is a major problem in obtaining reliable test results. Satisfactory growth is usually obtained on Middlebrook and Cohn 7H10 medium at pH 5.5 if albumin-dextrose-catalase (ADC) supplement rather than oleic acid-albumin-dextrose-catalase is used; however, some lots of ADC supplement still fail to support growth at this low pH. A rapid turbidimetric test was developed to determine the growth-suppo...

  6. In Vitro Susceptibility Testing of Tedizolid against Nontuberculous Mycobacteria

    OpenAIRE

    Brown-Elliott, Barbara A.; Wallace, Richard J.

    2017-01-01

    Tedizolid is a new oxazolidinone with improved in vitro and intracellular potency against Mycobacterium tuberculosis, including multidrug-resistant strains, and some species of nontuberculous mycobacteria (NTM) compared with that of linezolid. Using the current Clinical and Laboratory Standards Institute (CLSI)-recommended method of broth microdilution, susceptibility testing of 170 isolates of rapidly growing mycobacteria showed equivalent or lower (1- to 8-fold) MIC50 and/or MIC90 values fo...

  7. Accuracy of susceptibility testing of Pasteurella multocida and Mannheimia haemolytica.

    Science.gov (United States)

    Catry, Boudewijn; Dewulf, Jeroen; de Kruif, Aart; Vanrobaeys, Mia; Haesebrouck, Freddy; Decostere, Annemie

    2007-01-01

    The accuracy of antimicrobial susceptibility determinations relies on the bacterial species identification and the test methodology that is being used. In the present study, both aspects were investigated for 141 Pasteurella multocida and 34 Mannheimia haemolytica sensu lato isolates recovered from the upper respiratory tract of healthy calves. This was performed on the one hand by comparing of classical phenotyping with tDNA-PCR genotyping and on the other hand by pairwise comparison of disk diffusion with agar dilution results for seven antimicrobial compounds (ampicillin, ceftiofur, oxytetracycline, gentamicin, florfenicol, enrofloxacin, and the combination trimethoprim-sulfonamides). Phenotyping and genotyping correlated well (>90%). The pairwise comparisons of the susceptibility methods were investigated traditionally by means of error binding rates and sensitivity and specificity test characteristics. Obtained sensitivities (indication for absence of false susceptible results) were often lower than 85%, especially for older antimicrobial agents (oxytetracycline, gentamicin, trimethoprim-sulfonamides) and when M. haemolytica sensu lato was considered. Specificities (indication for absence of false-resistant results) exceeded 90% for almost all antimicrobial-bacterial combinations. The calculated test characteristics (sensitivities and specificities) were subsequently used in a second dataset of Pasteurellaceae from intensively (n = 99) and extensively housed calves (n = 196), to modify the apparent prevalence of antimicrobial resistance based upon disk diffusion results into an estimated true prevalence. It was concluded that the disk diffusion method is reliable in epidemiological studies like surveillance programs if resistance is sparse, whereas it needs to be interpreted with caution in situations where resistance is abundantly present.

  8. High-throughput metal susceptibility testing of microbial biofilms.

    Science.gov (United States)

    Harrison, Joe J; Turner, Raymond J; Ceri, Howard

    2005-10-03

    Microbial biofilms exist all over the natural world, a distribution that is paralleled by metal cations and oxyanions. Despite this reality, very few studies have examined how biofilms withstand exposure to these toxic compounds. This article describes a batch culture technique for biofilm and planktonic cell metal susceptibility testing using the MBEC assay. This device is compatible with standard 96-well microtiter plate technology. As part of this method, a two part, metal specific neutralization protocol is summarized. This procedure minimizes residual biological toxicity arising from the carry-over of metals from challenge to recovery media. Neutralization consists of treating cultures with a chemical compound known to react with or to chelate the metal. Treated cultures are plated onto rich agar to allow metal complexes to diffuse into the recovery medium while bacteria remain on top to recover. Two difficulties associated with metal susceptibility testing were the focus of two applications of this technique. First, assays were calibrated to allow comparisons of the susceptibility of different organisms to metals. Second, the effects of exposure time and growth medium composition on the susceptibility of E. coli JM109 biofilms to metals were investigated. This high-throughput method generated 96-statistically equivalent biofilms in a single device and thus allowed for comparative and combinatorial experiments of media, microbial strains, exposure times and metals. By adjusting growth conditions, it was possible to examine biofilms of different microorganisms that had similar cell densities. In one example, Pseudomonas aeruginosa ATCC 27853 was up to 80 times more resistant to heavy metalloid oxyanions than Escherichia coli TG1. Further, biofilms were up to 133 times more tolerant to tellurite (TeO3(2-)) than corresponding planktonic cultures. Regardless of the growth medium, the tolerance of biofilm and planktonic cell E. coli JM109 to metals was time

  9. Susceptibilidad "in vitro" de cepas de Cryptococcus a 5 drogas antifungicas "In vitro" susceptibility of Cryptococcus strains to 5 antifungal drugs

    Directory of Open Access Journals (Sweden)

    A. J. Bava

    1989-10-01

    Full Text Available Se estudió la susceptibilidad "in vitro" de 24 cepas de 3 especies del género Cryptococcus a 5 drogas antifúngicas (anfotericina B, 5 fluorocitosina, ketoconazol, itraconazol y miconazol. Las mismas se agruparon según su especie, variedad y origen de aislamiento. Para determinar la concentración inhibitoria mínima (C.I.M. de cada droga se empleó el método de dilución en agar con el medio básico nitrogenado para levaduras, adicionado de glucosa. Se obtuvo además la media geométrica de estos valores para cada grupo y se comparó cada uno de ellos. Los resultados obtenidos fueron homogéneos con la sola excepción de las cepas de Cryptococcus sp (no neoformans, en las cuales se detectaron elevados valores de C.I.M. para la 5 fluorocitosina.A comparative study of the "in vitro" susceptibility of 24 Cryptococcus strains to 5 antifungal drugs (amphotericin B, 5 fluorocytosine, miconazole, itraconazole and ketoconazole, was carried out. These strains were grouped according to species, varieties and isolation's origins. The minimum inhibitory concentration (M.I.C. was determinated by the agar dilution technique in yeast nitrogen base agar with dextrose. The mean geometrical of the M.I.C. values of each group was compared with the others. The results obtained were homogeneous with the only exception of the "non neoformans" strains, in which, higher M.I.C. to 5 fluorocytosine values were detected.

  10. Genetic susceptibility testing for beryllium: worker knowledge, beliefs, and attitudes.

    Science.gov (United States)

    Silver, Ken; Kukulka, Gary; Gorniewicz, John; Rayman, Kathleen; Sharp, Richard

    2011-07-01

    We sought to gain insight into workers' knowledge, beliefs, and attitudes on the subject of testing for genetic susceptibility to beryllium. Five focus groups were held with 30 current and former beryllium workers and nine family members. Audio recordings were transcribed and assessed by hierarchical coding using an inductive approach. Some workers were unclear about the distinction between genotoxicity and heritability. A key finding is that they perceived the benefits of a positive test result to be related to enhanced autonomous decision-making. The major concern cited by participants was potential abuse of genetic information by employers. Complete financial separation of a prospective testing entity from the employer was seen as crucial. A window of opportunity exists to create regional partnerships for translational research on genetic susceptibility testing. Such partnerships would involve labor, management, public health scientists, primary care professionals, and other stakeholders. They would be critical to identifying testing strategies that maximize worker autonomy along with the public health advantages of genetic testing. Copyright © 2011 Wiley-Liss, Inc.

  11. Electrochemical tests for pitting and crevice corrosion susceptibility

    International Nuclear Information System (INIS)

    Postlethwaite, J.

    1983-01-01

    Passive metals are being considered as container materials for the disposal of nuclear waste by deep burial. Localized corrosion is a potential problem and electrochemical techniques have an important role in the assessment of the susceptibility of these container materials to crevice and pitting corrosion. This paper critically reviews both the theoretical background and the experimental details of the electrochemical test methods presently used in both industrial and scientific studies of localized corrosion in both halide and non-halide solutions and identifies those areas where theory and experimental behaviour are in agreement and those areas for which there is neither well established theory nor an experimental test method

  12. A new approach for pyrazinamide susceptibility testing in Mycobacterium tuberculosis.

    Science.gov (United States)

    Zimic, Mirko; Loli, Sebastian; Gilman, Robert H; Gutierrez, Andrés; Fuentes, Patricia; Cotrina, Milagros; Kirwan, Daniela; Sheen, Patricia

    2012-08-01

    Pyrazinamide (PZA) is an important drug in the treatment of tuberculosis. Microbiological methods of PZA susceptibility testing are controversial and have low reproducibility. After conversion of PZA into pyrazinoic acid (POA) by the bacterial pyrazinamidase enzyme, the drug is expelled from the bacteria by an efflux pump. To evaluate the rate of POA extrusion from Mycobacterium tuberculosis as a parameter to detect PZA resistance. The rate of POA extrusion and PZA susceptibility determined by BACTEC 460 were measured for 34 strains in a previous study. PZA resistance was modeled in a logistic regression with the pyrazinoic efflux rate. POA efflux rate predicted PZA resistance with 70.83%-92.85% sensitivity and 100% specificity compared with BACTEC 460. POA efflux rate could be a useful tool for predicting PZA resistance in M. tuberculosis. Further exploration of this approach may lead to the development of new tools for diagnosing PZA resistance, which may be of public health importance.

  13. Atmospheric pressure cold plasma as an antifungal therapy

    International Nuclear Information System (INIS)

    Sun Peng; Wu Haiyan; Sun Yi; Liu Wei; Li Ruoyu; Zhu Weidong; Lopez, Jose L.; Zhang Jue; Fang Jing

    2011-01-01

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

  14. Antimicrobial susceptibility testing of bacteria that cause gastroenteritis.

    Science.gov (United States)

    Humphries, Romney M; Schuetz, Audrey N

    2015-06-01

    Gastroenteritis due to enteric pathogens is generally a self-limiting disease for which antimicrobial treatment is not required. However, treatment should be considered for cases of severe or prolonged diarrhea, extraintestinal isolation of bacteria, or diarrhea in immunocompromised hosts, the elderly, and infants. Various resistance trends and current issues concerning antimicrobial susceptibility testing of enteric pathogens are reviewed in this article, including Campylobacter, Salmonella, Shigella, Vibrio, Aeromonas, Plesiomonas, and Clostridium difficile. Updated interpretive criteria from breakpoint-setting organizations are reviewed, along with explanations for recent changes in antimicrobial breakpoints. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics

    DEFF Research Database (Denmark)

    Rathe, Mathias; Lise, Kristensen,; Ellermann-Eriksen, Svend

    Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics......Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics...

  16. Antifungal compounds from cyanobacteria.

    Science.gov (United States)

    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.

  17. Assessment of diagnostics and antimicrobial susceptibility testing of Brachyspira species using a ring test

    DEFF Research Database (Denmark)

    Rasback, T.; Fellstrøm, C.; Bergsjo, B.

    2005-01-01

    There is no ring test for quality assessment available in Europe for diagnostics and antimicrobial susceptibility testing of the fastidious, anaerobic bacteria of the genus Brachyspira. Therefore, an international ring test for Brachyspira spp. was performed once a year during 2002-2004. Two sets...

  18. Candidemia in a Brazilian tertiary care hospital: species distribution and antifungal susceptibility patterns Candidemia em hospital terciário brasileiro: distribuição das espécies e padrões de susceptibilidade aos antifúngicos

    Directory of Open Access Journals (Sweden)

    Ana Graciela Ventura Antunes

    2004-10-01

    Full Text Available Recent studies have shown differences in the epidemiology of invasive infections caused by Candida species worldwide. In the period comprising August 2002 to August 2003, we performed a study in Santa Casa Complexo Hospitalar, Brazil, to determine Candida species distribution associated with candidemia and their antifungal susceptibility profiles to amphotericin B, fluconazole and itraconazole. Antifungal susceptibility was tested according to the broth microdilution method described in the NCCLS (M27A-2 method. Only one sample from each patient was analyzed (the first isolate. Most of the episodes had been caused by species other than C. albicans (51.6%, including C. parapsilosis (25.8%, C. tropicalis (13.3%, C. glabrata (3.3%, C. krusei (1.7%, and others (7.5%. Dose-dependent susceptibility to itraconazole was observed in 14.2% of strains, and dose-dependent susceptibility to fluconazole was found in 1.6%. Antifungal resistance was not found, probably related to low use of fluconazole. Further epidemiological surveillance is needed.Estudos realizados em diferentes países têm mostrado diferença na epidemiologia das infecções invasivas por Candida spp. No período de agosto de 2002 a agosto de 2003, foi conduzido estudo na Santa Casa Complexo Hospitalar, Porto Alegre, Brasil, para determinar a distribuição das espécies de Candida associadas a candidemia e o perfil de susceptibilidade das mesmas aos antifúngicos anfotericina B, fluconazol e itraconazol. Os testes de susceptibilidade foram realizados de acordo com a metodologia M27-A2 padronizada pelo NCCLS. Foi incluído no estudo o primeiro isolado de hemocultivo de cada paciente. A maioria dos episódios (51,6% ocorreu por espécies outras que C. albicans, incluindo C. parapsilosis (25,8%, C. tropicalis (13,3%, C. glabrata (3,3%, C. krusei (1,7% e outras espécies (7,5%. Não foi encontrada resistência aos antifúngicos testados, possivelmente devido ao baixo consumo de fluconazol na

  19. Microbial sensor for drug susceptibility testing of Mycobacterium tuberculosis.

    Science.gov (United States)

    Zhang, Z-T; Wang, D-B; Li, C-Y; Deng, J-Y; Zhang, J-B; Bi, L-J; Zhang, X-E

    2018-01-01

    Drug susceptibility testing (DST) of clinical isolates of Mycobacterium tuberculosis is critical in treating tuberculosis. We demonstrate the possibility of using a microbial sensor to perform DST of M. tuberculosis and shorten the time required for DST. The sensor is made of an oxygen electrode with M. tuberculosis cells attached to its surface. This sensor monitors the residual oxygen consumption of M. tuberculosis cells after treatment with anti-TB drugs with glycerine as a carbon source. In principle, after drug pretreatment for 4-5 days, the response differences between the sensors made of drug-sensitive isolates are distinguishable from the sensors made of drug-resistant isolates. The susceptibility of the M. tuberculosis H37Ra strain, its mutants and 35 clinical isolates to six common anti-TB drugs: rifampicin, isoniazid, streptomycin, ethambutol, levofloxacin and para-aminosalicylic acid were tested using the proposed method. The results agreed well with the gold standard method (LJ) and were determined in significantly less time. The whole procedure takes approximately 11 days and therefore has the potential to inform clinical decisions. To our knowledge, this is the first study that demonstrates the possible application of a dissolved oxygen electrode-based microbial sensor in M. tuberculosis drug resistance testing. This study used the microbial sensor to perform DST of M. tuberculosis and shorten the time required for DST. The overall detection result of the microbial sensor agreed well with that of the conventional LJ proportion method and takes less time than the existing phenotypic methods. In future studies, we will build an O 2 electrode array microbial sensor reactor to enable a high-throughput drug resistance analysis. © 2017 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of The Society for Applied Microbiology.

  20. [Rapid test for detection of susceptibility to cefotaxime in Enterobacteriaceae].

    Science.gov (United States)

    Jiménez-Guerra, Gemma; Hoyos-Mallecot, Yannik; Rodríguez-Granger, Javier; Navarro-Marí, José María; Gutiérrez-Fernández, José

    In this work an "in house" rapid test based on the change in pH that is due to hydrolysis for detecting Enterobacteriaceae susceptible to cefotaxime is evaluated. The strains of Enterobacteriaceae from 1947 urine cultures were assessed using MicroScan panels and the "in house" test. This rapid test includes red phenol solution and cefotaxime. Using MicroScan panels, 499 Enterobacteriaceae isolates were evaluated, which included 27 isolates of Escherichia coli producing extended-spectrum beta-lactamases (ESBL), 16 isolates of Klebsiella pneumoniae ESBL and 1 isolate of Klebsiella oxytoca ESBL. The "in house" test offers the following values: sensitivity 98% and specificity 97%, with negative predictive value 100% and positive predictive value 78%. The "in house" test based on the change of pH is useful in our area for detecting presumptively cefotaxime-resistant Enterobacteriaceae strains. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Separation, determination and antifungal activity test of the products from a new Bacillus amyloliquefaciens.

    Science.gov (United States)

    Wang, Tao; Wu, Mian-Bin; Chen, Zheng-Jie; Lin, Jian-Pin; Yang, Li-Rong

    2016-01-01

    A new Bacillus amyloliquefaciens named ZJU-2011 was discovered, and the culture supernatant showed a strong inhibitory effect against Candida albicans. In this study, a novel method was developed to purify the antifungal compounds in high purity. The obtained products were analysed by high performance liquid chromatography and proven to be of high purity. Mass spectrometry showed that the molecular weights of the two bioactive components were 270 and 288, respectively, and their structures were determined to be bacilysin and chlorotetaine by using (1)H and (13)C nuclear magnetic resonance spectroscopy. To the best of our knowledge, this is the first time that B. amyloliquefaciens has been reported to produce bacilysin and chlorotetaine simultaneously. The minimum inhibitory concentration of chlorotetaine against six common fungal pathogens were determined to be in the range of 1.8-7.8 μg/mL.

  2. Antifungal pharmacodynamics: Latin America's perspective.

    Science.gov (United States)

    Gonzalez, Javier M; Rodriguez, Carlos A; Agudelo, Maria; Zuluaga, Andres F; Vesga, Omar

    The current increment of invasive fungal infections and the availability of new broad-spectrum antifungal agents has increased the use of these agents by non-expert practitioners, without an impact on mortality. To improve efficacy while minimizing prescription errors and to reduce the high monetary cost to the health systems, the principles of pharmacokinetics (PK) and pharmacodynamics (PD) are necessary. A systematic review of the PD of antifungals agents was performed aiming at the practicing physician without expertise in this field. The initial section of this review focuses on the general concepts of antimicrobial PD. In vitro studies, fungal susceptibility and antifungal serum concentrations are related with different doses and dosing schedules, determining the PD indices and the magnitude required to obtain a specific outcome. Herein the PD of the most used antifungal drug classes in Latin America (polyenes, azoles, and echinocandins) is discussed. Copyright © 2016 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

  3. Antifungal pharmacodynamics: Latin America's perspective

    Directory of Open Access Journals (Sweden)

    Javier M. Gonzalez

    2017-01-01

    Full Text Available The current increment of invasive fungal infections and the availability of new broad-spectrum antifungal agents has increased the use of these agents by non-expert practitioners, without an impact on mortality. To improve efficacy while minimizing prescription errors and to reduce the high monetary cost to the health systems, the principles of pharmacokinetics (PK and pharmacodynamics (PD are necessary. A systematic review of the PD of antifungals agents was performed aiming at the practicing physician without expertise in this field. The initial section of this review focuses on the general concepts of antimicrobial PD. In vitro studies, fungal susceptibility and antifungal serum concentrations are related with different doses and dosing schedules, determining the PD indices and the magnitude required to obtain a specific outcome. Herein the PD of the most used antifungal drug classes in Latin America (polyenes, azoles, and echinocandins is discussed.

  4. In vitro activities of antifungal drugs against environmental Exophiala isolates and review of the literature.

    Science.gov (United States)

    Gülmez, Dolunay; Doğan, Özlem; Boral, Barış; Döğen, Aylin; İlkit, Macit; de Hoog, G Sybren; Arikan-Akdagli, Sevtap

    2018-04-03

    Exophiala is a genus of black fungi isolated worldwide from environmental and clinical specimens. Data on antifungal susceptibility of Exophiala isolates are limited and the methodology on susceptibility testing is not yet standardized. In this study, we investigated in vitro antifungal susceptibilities of environmental Exophiala isolates. A total of 87 Exophiala isolated from dishwashers or railway ties were included. CLSI M38-A2 microdilution method with modifications was used to determine antifungal susceptibility for fluconazole, voriconazole, posaconazole, itraconazole, amphotericin B, and terbinafine. Minimum inhibitory concentration (MIC) values were determined visually at 48h, 72h, and 96h. MIC-0 endpoint (complete inhibition of growth) was used for amphotericin B and azoles, except fluconazole, for which MIC-2 endpoint (~50% inhibition compared to growth control) was used. Both MIC-0 and MIC-1 (~80% inhibition compared to growth control) results were analysed for terbinafine, to enable comparison with previous studies. Fungal growth was sufficient for determination of MICs at 48h for all isolates except two Exophiala dermatitidis strains. At 72h, most active antifungal agents according to GM MIC were voriconazole and terbinafine, followed by posaconazole, itraconazole, and amphotericin B in rank order of decreasing activity. While amphotericin B displayed adequate in vitro activity despite relatively high MICs, fluconazole showed no meaningful antifungal activity against Exophiala. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. Children's differential susceptibility to parenting : An experimental test of “for better and for worse”

    NARCIS (Netherlands)

    Slagt, Meike; Dubas, Judith Semon; van Aken, Marcel; Ellis, Bruce J.; Dekovic, Maja

    2017-01-01

    Differential susceptibility theory proposes that a subset of individuals exist who display enhanced susceptibility to both negative (risk-promoting) and positive (development-enhancing) environments. This experiment represents the first attempt to directly test this assumption by exposing children

  6. In Vitro Susceptibility Testing of Tedizolid against Isolates of Nocardia.

    Science.gov (United States)

    Brown-Elliott, Barbara A; Wallace, Richard J

    2017-12-01

    There is a paucity of efficacious antimicrobials (especially oral) against clinically relevant species of Nocardia To date, all species of Nocardia have been susceptible to linezolid, the first commercially available oxazolidinone. Tedizolid is a new oxazolidinone with previously reported improved in vitro and in vivo (intracellular) potency against multidrug-resistant strains of Mycobacterium sp. and Nocardia brasiliensis Using the current Clinical and Laboratory Standards Institute-recommended broth microdilution method, 101 isolates of Nocardia spp., including 29 Nocardia cyriacigeorgica , 17 Nocardia farcinica , 13 Nocardia nova complex, 21 Nocardia brasiliensis , 5 Nocardia pseudobrasiliensis , and 5 Nocardia wallacei isolates and 11 isolates of less common species, were tested for susceptibility to tedizolid and linezolid. For the most common clinically significant species of Nocardia , tedizolid MIC 50 values were 0.25 μg/ml for N. nova complex, N. brasiliensis , N. pseudobrasiliensis , and N. wallacei , compared to linezolid MIC 50 values of 1, 2, 0.5, and 1 μg/ml, respectively. Tedizolid and linezolid MIC 90 values were 2 μg/ml for N. nova complex and N. brasiliensis Tedizolid MIC 50 and MIC 90 values for both N. cyriacigeorgica and N. farcinica were 0.5 μg/ml and 1 μg/ml, respectively, compared to linezolid MIC 50 and MIC 90 values of 2 and 4 μg/ml, respectively. Based on MIC 90 values, this study showed that tedizolid was 2- to 3-fold more active than linezolid in vitro against most common species of Nocardia , with the exception of the N. nova complex and N. brasiliensis , for which values were the same. These results may warrant evaluation of tedizolid as a potential treatment option for Nocardia infections. Copyright © 2017 American Society for Microbiology.

  7. Rapid drug susceptibility test of mycobacterium tuberculosis by bioluminescence sensor

    Science.gov (United States)

    Lu, Bin; Xu, Shunqing; Chen, Zifei; Zhou, Yikai

    2001-09-01

    With the persisting increase of drug-resistant stains of M. Tuberculosis around the world, rapid and sensitive detection of antibiotic of M. Tuberculosis is becoming more and more important. In the present study, drug susceptibility of M. tuberculosis were detected by recombination mycobacteriophage combined with bioluminescence sensor. It is based on the use of recombination mycobacteriophage which can express firefly luciferase when it infects viable mycobacteria, and can effectively produce quantifiable photon. Meanwhile, in mycobacterium cells treated with active antibiotic, no light is observed. The emitted light is recorded by a bioluminscence sensor, so the result of drug-resistant test can be determined by the naked eye. 159 stains of M. tuberculosis were applied to this test on their resistant to rifampin, streptomycin and isoniazid. It is found that the agreement of this assay with Liewenstein- Jensen slat is: rifampin 95.60 percent, isoniazid 91.82 percent, streptomycin 88.68 percent, which showed that it is a fast and practical method to scene and detect drug resistant of mycobacterium stains.

  8. Testing anti-fungal activity of a soil-like substrate for growing plants in bioregenerative life support systems

    Science.gov (United States)

    Nesterenko, E. V.; Kozlov, V. A.; Khizhnyak, S. V.; Manukovsky, N. S.; Kovalev, V. S.; Gurevich, Yu. L.; Liu, Hong; Xing, Yidong; Hu, Enzhu

    2009-10-01

    The object of this research is to study a soil-like substrate (SLS) to grow plants in a Bioregenerative Life Support System (BLSS). Wheat and rice straw were used as raw materials to prepare SLS. Anti-fungal activity of SLS using test cultures of Bipolaris sorokiniana, a plant-pathogenic fungus which causes wheat root rot was studied. Experiments were conducted with SLS samples, using natural soil and sand as controls. Infecting the substrates, was performed at two levels: the first level was done with wheat seeds carrying B. sorokiniana and the second level with seeds and additional conidia of B. sorokiniana from an outside source. We measured wheat disease incidence and severity in two crop plantings. Lowest disease incidence values were obtained from the second planting, SLS: 26% and 41% at the first and the second infection levels, respectively. For soil the values were 60% and 82%, respectively, and for sand they were 67% and 74%, respectively. Wheat root rot in the second crop planting on SLS, at both infection levels was considerably less severe (9% and 13%, respectively) than on natural soil (20% and 33%) and sand (22% and 32%). SLS significantly suppressed the germination of B. sorokiniana conidia. Conidia germination was 5% in aqueous SLS suspension, and 18% in clean water. No significant differences were found regarding the impact on conidia germination between the SLS samples obtained from wheat and rice straw. The anti-fungal activity in SLS increased because of the presence of worms. SLS also contained bacteria stimulating and inhibiting B. sorokiniana growth.

  9. Improvement of mupirocin E-test for susceptibility testing of Staphylococcus aureus.

    Science.gov (United States)

    Mondino, Pedro Juan José; Dos Santos, Kátia Regina Netto; de Freire Bastos, Maria do Carmo; Giambiagi-deMarval, Marcia

    2003-05-01

    Interpretation of the mupirocin E-test for low-level mupirocin-resistant Staphylococcus aureus strains has been improved by adding the indicator dye tetrazolium. E-tests were compared with agar dilution methods for assessing mupirocin susceptibility. MICs obtained by the agar dilution method and E-tests showed 89.3% agreement within 2 log(2) dilution criteria. The agreement between MICs increased to 100% in the 1 log(2) dilution definition when the indicator dye tetrazolium was added to the E-test. The use of the E-test with tetrazolium reduction is more accurate for determining mupirocin MICs for S. aureus strains.

  10. 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.

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Factors affecting griseofulvin susceptibility testing of Trichophyton rubrum in microcultures.

    Science.gov (United States)

    Granade, T C; Artis, W M

    1982-01-01

    A microculture broth assay system for griseofulvin susceptibility testing of Trichophyton rubrum was further characterized. The effects of mass and number of colony-forming units of a fragmented mycelial inoculum, 5- or 8-day incubation periods, 25 or 32 degrees C incubation temperatures, and the solvents used to dissolve griseofulvin on the minimal inhibitory concentration (MIC) of griseofulvin were determined. An inoculum density with an absorbance of 0.600 at 450 nm ensured successful inoculation of all microcultures. Reduction of the inoculum mass to an absorbance of 0.200 lowered the number of colony-forming units in the inoculum by 60 to 80%. This decreased the efficiency of inoculation but did not alter the resulting MIC. There was no correlation between MIC and the number of colony-forming units used to initiate growth. Neither incubation temperature nor the length of incubation affected the MIC. The use of either acetone or ethanol to solubilize griseofulvin likewise had no effect on the MIC. The mean reproducibility of the MICs determined with the microculture method was 96%. Images PMID:7161372

  12. Family Matters: Adjustment to genetic cancer susceptibility testing

    OpenAIRE

    Oostrom, Iris

    2006-01-01

    textabstractCancer is generally feared because it is associated with death and severe physical suffering. It is one of the most common causes of death in the Netherlands. Breast and colon cancer are the most prevalent types of cancer among women. Frequently occurring types in men are cancer of colon, lung and prostate. About 5% of colorectal and breast cancer arises as a result of a mutation in an inherited cancer susceptibility gene. Knowledge about these cancer susceptibility genes has been...

  13. In Vitro Susceptibility Testing of Tedizolid against Nontuberculous Mycobacteria.

    Science.gov (United States)

    Brown-Elliott, Barbara A; Wallace, Richard J

    2017-06-01

    Tedizolid is a new oxazolidinone with improved in vitro and intracellular potency against Mycobacterium tuberculosis , including multidrug-resistant strains, and some species of nontuberculous mycobacteria (NTM) compared with that of linezolid. Using the current Clinical and Laboratory Standards Institute (CLSI)-recommended method of broth microdilution, susceptibility testing of 170 isolates of rapidly growing mycobacteria showed equivalent or lower (1- to 8-fold) MIC 50 and/or MIC 90 values for tedizolid compared with that for linezolid. The tedizolid MIC 90 values for 81 isolates of M. abscessus subsp. abscessus and 12 isolates of M. abscessus subsp. massiliense were 8 μg/ml and 4 μg/ml, respectively, compared with linezolid MIC 90 values of 32 μg/ml for both. The MIC 90 values for 20 isolates of M. fortuitum were 2 μg/ml for tedizolid and 4 μg/ml for linezolid. Twenty-two isolates of M. chelonae had tedizolid and linezolid MIC 90 s of 2 μg/ml and 16 μg/ml, respectively. One hundred forty-two slowly growing NTM, including 7/7 M. marinum , 7/7 M. kansasii , and 7/11 of other less commonly isolated species, had tedizolid MICs of ≤1 μg/ml and linezolid MICs of ≤4 μg/ml. One hundred isolates of Mycobacterium avium complex and eight M. simiae isolates had tedizolid MIC 50 s of 8 μg/ml and linezolid MIC 50 s 32 and 64 μg/ml, respectively. Nine M. arupense isolates had MIC 50 s of 4 μg/ml and 16 μg/ml for tedizolid and linezolid, respectively. These findings demonstrate a greater in vitro potency of tedizolid than linezolid against NTM and suggest that an evaluation of tedizolid as a potential treatment agent for infections caused by selected NTM is warranted. Copyright © 2017 American Society for Microbiology.

  14. Whole Genome Sequencing of Candida glabrata for Detection of Markers of Antifungal Drug Resistance.

    Science.gov (United States)

    Biswas, Chayanika; Chen, Sharon C-A; Halliday, Catriona; Martinez, Elena; Rockett, Rebecca J; Wang, Qinning; Timms, Verlaine J; Dhakal, Rajat; Sadsad, Rosemarie; Kennedy, Karina J; Playford, Geoffrey; Marriott, Deborah J; Slavin, Monica A; Sorrell, Tania C; Sintchenko, Vitali

    2017-12-28

    Candida glabrata can rapidly acquire mutations that result in drug resistance, especially to azoles and echinocandins. Identification of genetic mutations is essential, as resistance detected in vitro can often be correlated with clinical failure. We examined the feasibility of using whole genome sequencing (WGS) for genome-wide analysis of antifungal drug resistance in C. glabrata. The aim was torecognize enablers and barriers in the implementation WGS and measure its effectiveness. This paper outlines the key quality control checkpoints and essential components of WGS methodology to investigate genetic markers associated with reduced susceptibility to antifungal agents. It also estimates the accuracy of data analysis and turn-around-time of testing. Phenotypic susceptibility of 12 clinical, and one ATCC strain of C. glabrata was determined through antifungal susceptibility testing. These included three isolate pairs, from three patients, that developed rise in drug minimum inhibitory concentrations. In two pairs, the second isolate of each pair developed resistance to echinocandins. The second isolate of the third pair developed resistance to 5-flucytosine. The remaining comprised of susceptible and azole resistant isolates. Single nucleotide polymorphisms (SNPs) in genes linked to echinocandin, azole and 5-flucytosine resistance were confirmed in resistant isolates through WGS using the next generation sequencing. Non-synonymous SNPs in antifungal resistance genes such as FKS1, FKS2, CgPDR1, CgCDR1 and FCY2 were identified. Overall, an average of 98% of the WGS reads of C. glabrata isolates mapped to the reference genome with about 75-fold read depth coverage. The turnaround time and cost were comparable to Sanger sequencing. In conclusion, WGS of C. glabrata was feasible in revealing clinically significant gene mutations involved in resistance to different antifungal drug classes without the need for multiple PCR/DNA sequencing reactions. This represents a

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

    Directory of Open Access Journals (Sweden)

    Deepa Gupta

    2015-01-01

    Full Text Available 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.

  16. In vitro susceptibility testing of Yersinia species to eight plant ...

    African Journals Online (AJOL)

    AJL

    2012-05-24

    May 24, 2012 ... V. amygdalina Del against Y. enterocolitica 0:03 to 17.7 mm for Citrus aurantifolia (christim) Swingle .... The inhibitory effect of neat ethanolic plant extracts and some natural antimicrobials against Yersinia sp. .... Susceptibility pattern of Yersinia sp. to the various antimicrobial agents (ethanolic extracts).

  17. Comparing the disk-diffusion and agar dilution tests for Neisseria gonorrhoeae antimicrobial susceptibility testing

    Directory of Open Access Journals (Sweden)

    Hsi Liu

    2016-11-01

    Full Text Available Abstract Background We assessed the validity of testing for antimicrobial susceptibility of clinical and mutant Neisseria gonorrhoeae (GC isolates by disk diffusion in comparison to agar dilution, and Etest® (bioMerieux, France, respectively, for three third generation extended spectrum cephalosporins (ESC: ceftriaxone (CRO, cefixime (CFX, and cefpodoxime (CPD. Methods One hundred and five clinical isolates and ten laboratory-mutants were tested following Clinical Laboratory Standard Institute (CLSI and manufacturer’s standards for each of the three methods. The measured diameters by the disk diffusion method were tested for correlation with the MIC values by agar dilution. In addition, comparisons with the Etest® were made. Categorical results for concordance, based on standard CLSI cutoffs, between the disk diffusion and the other two methods, respectively, were tested using the Chi-square statistics. Reproducibility was tested for CFX across a 6-month interval by repeated disk tests. Results Across all 115 specimens, the disk diffusion tests produced good categorical agreements, exhibiting concordance of 93.1%, 92.1%, and 90.4% with agar dilution and 93.0%, 92.1%, and 90.4% with Etest®, for CRO, CFX, and CPD, respectively. Pearson correlations between disk-diffusion diameters and agar dilution MIC’s were -0.59, -0.67, and -0.81 for CRO, CFX, and CPD, respectively. The correlations between disk diffusion and Etest® were -0.58, -0.73, and -0.49. Pearson correlation between the CFX disk readings over a 6-month interval was 91%. Conclusions Disk diffusion tests remain to be a useful, reliable and fast screening method for qualitative antimicrobial susceptibility testing for ceftriaxone, cefixime, and cefpodoxime.

  18. First report of environmental isolation of Cryptococcus neoformans and other fungi from pigeon droppings in Makkah, Saudi Arabia and in vitro susceptibility testing

    Directory of Open Access Journals (Sweden)

    Hussein Hasan Abulreesh

    2015-08-01

    Full Text Available Objective: To verify the occurrence of Cryptococcus neoformans (C. neoformans and other fungi in samples of pigeon droppings collected from Makkah city, Saudi Arabia. Methods: One hundred and twelve withered pigeon dropping samples were collected from 12 different districts. Using the dilution plate technique, samples were cultured on Sabouraud dextrose agar and esculin agar. Colonies were examined microscopically and C. neoformans identification is confirmed by India ink preparation, observation of urease activity and brown pigmentation on esculin medium. Susceptibility patterns of five yeast species and four molds against five antifungal drugs were tested using agar disk diffusion method. Results: C. neoformans was recovered from 38 samples (34%. Na'aman valley was recorded to be the highest contaminated site (66.7% with C. neoformans, while the samples collected from Al Awaly district were considered as the lowest contaminated samples (6.7%. Also, twenty species related to sixteen genera of fungi other than C. neoformans were recovered from which, three yeast genera were recorded. The antifungal susceptibility testing showed that the nine tested fungal species were sensitive to Mycosat, while Fungican exerted inhibition zones of four species only. C. neoformans was moderately sensitive towards all tested compounds but it can resist Flucoral where no inhibition zone could be detected. Conclusions: Our results are considered to be the first report on the environmental prevalence of C. neoformans in pigeon feces in Makkah, Saudi Arabia. The data indicated that pigeon droppings can be considered as a potential source of this basidiomycetous yeast in addition to other fungal species in this region.

  19. The comparative study of antifungal activity of Syzygium aromaticum, Punica granatum and nystatin on Candida albicans; an in vitro study.

    Science.gov (United States)

    Mansourian, A; Boojarpour, N; Ashnagar, S; Momen Beitollahi, J; Shamshiri, A R

    2014-12-01

    Candida species are opportunistic fungi, among which, Candida albicans is the most important species responsible for infections in immunocompromised patients with invasive fungal disease. Resistance of Candida species to antifungal drugs has led scientists to pay more attention to traditional medicine herbs. Due to the limitations in the treatment of fungal diseases such as shortages, high prices, antifungal side effects and drug resistance or reduced susceptibility to fungal drugs we decided to study the antifungal effects of herbal extracts of Syzygium aromaticum and Punica granatum. Twenty-one isolates of oral C. albicans in patients with denture stomatitis referred to prosthesis department, Dental faculty of Tehran University of Medical Sciences were prepared and cultured. Plant extracts were prepared from the herbs market. Tests on patient samples and standard strains 5027ATCC (PTCC10231) yeast C. albicans were performed via well diffusion method. In addition, nystatin and methanol were used as positive and negative control, respectively. Finally, the antifungal effect of extracts using Statistical Repeated measurement ANOVA test was investigated. Both S. aromaticum and P. granatum showed noticeable antifungal activity in well method. Syzygium aromaticum showed better anti candida activity than nystatin (Pgranatum showed good antifungal effects (P-value<0.001). S. aromaticum (inhibition zone diameter: 29.62) showed better antifungal effects than nystatin (inhibition zone diameter: 28.48). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  20. Adhesion and biofilm formation in artificial saliva and susceptibility of yeasts isolated from chronic kidney patients undergoing haemodialysis.

    Science.gov (United States)

    Queiroz, Paula Assis; Godoy, Janine Silva Ribeiro; Mendonça, Patrícia de Souza Bonfim; Pedroso, Raíssa Bocchi; Svidzinski, Terezinha Inez Estivalet; Negri, Melyssa

    2015-09-01

    Yeasts of the genera Candida and Saccharomyces are opportunist pathogens and cause oral lesions, especially in immunocompromised patients. This study assessed yeasts isolated from chronic kidney patients undergoing haemodialysis for their adhesion capacity, biofilm formation and susceptibility to antifungal agents. Ten isolates of Candida spp. and one isolate of Saccharomyces cerevisiae were tested for adhesion to buccal epithelial cells (BECs), adhesion and formation of biofilm in artificial saliva and their susceptibility profile to antifungal agents. Adhesion and biofilm formation were undertaken in polystyrene plates with artificial saliva, whilst susceptibility to antifungal agents was evaluated by broth microdilution. Candida parapsilosis had the highest adhesion index in BECs (154.55 ± 22.13) and Candida rugosa was the species with the highest adhesion capacity (18 398  Abs cm(-2)) in abiotic surface with artificial saliva. Candida albicans provided the greatest biofilm formation (2035  Abs cm(-2) ± 0.09) but was revealed to be susceptible to the five antifungal agents under analysis. However, some non-albicans Candida isolates showed a lower susceptibility for the antifungal agents itraconazole, fluconazole and voriconazole. All of the species were sensitive to amphotericin B and nystatin. The current analysis showed that yeasts isolated from the mouth of chronic kidney patients undergoing haemodialysis varied significantly with regard to their capacity for adherence, biofilm formation and susceptibility to antifungal agents, underscoring the high virulence of non-albicans Candida species.

  1. Development of EUCAST disk diffusion method for susceptibility testing of the Bacteroides fragilis group isolates

    DEFF Research Database (Denmark)

    Nagy, Elisabeth; Justesen, Ulrik Stenz; Eitel, Zsuzsa

    2015-01-01

    With the emergence of antibiotic resistance among Bacteroides fragilis group isolates the need of susceptibility testing in routine laboratories is increasing. The aims of the present study were to evaluate the disk diffusion method for susceptibility testing in case of different clinical isolates...... of Bacteroides spp by comparing zone diameter results with MICs obtained earlier during an Europe-wide antibiotic susceptibility surveillance, and to propose zone diameter breakpoints, which correlate for the EUCAST MIC breakpoints. We tested 381 clinical isolates of the B. fragilis group to amoxicillin...... testing of B. fragilis group isolates for most relevant antibiotics in routine laboratories....

  2. The Antifungal Inhibitory Concentration Effectiveness Test From Ethanol Seed Arabica Coffee (Coffea arabica) Extract Against The Growth Of Candida albicans Patient Isolate With In Vitro Method

    Science.gov (United States)

    Satria Rakatama, Adam; Pramono, Andri; Yulianti, Retno

    2018-03-01

    Candida albicans are the most frequent cause of Vulvovaginalis Candidiasis infection. Its treatment using antifungal drugs, are oftenly caused side effects. The reduction of C.albicans growth and the reduction of antifungal drugs side effect, were our main purposed. Our study objective is determine the effectiveness of inhibitory power of arabica coffee seed ethanol extract on the growth of C.albicans patient isolates. The type of this research is experimental research. Kirby-bauer method with the Saboraud Dextrose Agar (SDA) media was used in this experiment. Inhibitory zone was observed around the disc, to determine the inhibitory power. The results showed that the inhibitory zone was formed on arabica coffee seed ethanol extract on 10%, 20%, 40%, and 80% concentration. Kruskal-Wallis test results (palbicans patient isolates were smaller compared with C.albicans ATCC 90028 as gold standard. This showed that the virulence of C.albicans from patients isolates were higher. We concluded that arabica coffee seed ethanol extract could inhibiting the growth of C.albicans patient isolates. Optimization of coffee seed ethanol extract to obtain maximum active ingredients still needs to be done. This knowledge is expected to be used for the beginning manufacturer antifungal drug from natural product.

  3. Susceptibility to heat and antifungal agents of Cryptococcus neoformans var. neoformans (serotype D isolated from Eucalyptus spp in Rio Grande do Sul, Brazil Susceptibilidade de Cryptococcus neoformans var. neoformans (sorotipo D isolados de Eucalyptus spp., no Rio Grande do Sul (Brasil, frente ao calor e a agentes antifúngicos

    Directory of Open Access Journals (Sweden)

    Jorge A Horta

    2005-03-01

    Full Text Available In this work we studied the susceptibility to heat and antifungal agents of the first strains of environmental Cryptococcus neoformans var neoformans (serotype D isolated in the state of Rio Grande do Sul, Brazil. In order to achieve a rigorous analysis, we employed the methodology recommended by NCCLS, Yeast Nitrogen Base (YNB proposed by Ghannoum et al (YNB-1, Antibiotic medium 3 (AM3 indicated by others, YNB adjusted to the NCCLS methodology (YNB-2 and Etest. Our results indicate that all strains were susceptible to amphotericin B (0.0625-0.5 µg/mL, fluconazole (0.125-8.0 µg/mL, itraconazole (0.031-0.25 µg/mL and flucytosine (0.125-4.0 µg/mL. The C. neoformans serotype D strains were more susceptible to heat (47ºC/30 min than C. neoformans serotype A.Este estudo foi realizado com os primeiros isolados ambientais de C. neoformans sorotipo D, obtidos no Rio Grande do Sul. Objetivando-se avaliar a susceptibilidade a agentes antifúngicos de forma mais rigorosa, utilizou-se a técnica de referência proposta pelo NCCLS, Caldo Yeast Nitrogen Base (YNB proposto por Ghannoum et al., Antibiotic medium 3, caldo YNB adequado à metodologia do NCCLS e o E-test. Os resultados indicaram que todos os isolados foram sensíveis à anfotericina B (0,0625-0,5 µg/mL, fluconazol (0,125-4,0 µg/mL, itraconazol (0,031-0,25 µg/ml e fluorocitosina (0,125-4,0 µg/mL através das técnicas empregadas. Nos testes de termotolerância (47ºC/30 min, observou-se que as culturas de C. neoformans sorotipo D são mais sensíveis do que as de C. neoformans sorotipo A.

  4. Susceptibility testing of Streptococcus pneumoniae and Viridans streptococcal isolates against: quinolones, oxazolidinones and glycopeptides.

    Science.gov (United States)

    Băncescu, Gabriela; Neagu, Amalia-Sofia; Radu-Popescu, Manuela; Nica, Maria; Dascălu, Amalia; Nistor, Irina; Bărbuceanu, Stefania-Felicia; Băncescu, A

    2012-01-01

    The aim of this study was to test the susceptibility of 100 strains (pneumococci and viridans streptococci) isolated from oral and respiratory tract infections and their complications, against one antibiotic of each of the following classes: quinolones, oxazolidinones and glycopeptides. The Etest has been used in order to investigate the susceptibility of the isolates against levofloxacin, linezolid and vancomycin. As expected, the results of the study indicated that all isolates were susceptible to linezolid and vancomycin. In contrast to the pneumococcal isolates, which were all susceptible to levofloxacin, 10% of the viridans strains showed resistance to this quinolone. When fluoroquinolones are needed as an alternative to the beta-lactam antibiotics in infections in which oral streptococci are involved, the in vitro susceptibility testing is required.

  5. In vitro susceptibility of Paracoccidioides brasiliensis yeast form to antifungal agents Susceptibilidad in vitro de la forma levaduriforme de Paracoccidioides brasiliensis a los agentes antifungicos

    Directory of Open Access Journals (Sweden)

    Angela Restrepo

    1984-12-01

    Full Text Available A study was conducted to determine the susceptibility of P. brasiliensis yeast form to amphotericin B (A, ketoconazole (K, 5-fluorocytosine (5-FC and rifampin (R. The three isolates tested produced minimal inhibitory concentrations (MICs (mcg/ml in the following range: A: 0.09-0.18; K: 0.001-0.007; 5-FC: 62.5-250 and R: 40-80. The minimal fungicidal concentrations (MFC were several times higher than the corresponding MICs. Precise MFC for 5-FC were not obtained (> 500 mcg/ml. Combination of K plus A proved synergic, with the fractional inhibitory concentration (FIC indices revealing synergy when the drugs were combined at the 1 to 1 and 1 to 5 MIC ratios. R (40 mcg/ml appeared to antagonize K. These results indicate promise for the combined use of K plus A as a therapeutical regimen.Se realizó un estudio con el objeto de determinar la susceptibilidad de la fase levaduri-forme del P. brasiliensis a la Anfotericina B (A, el Ketoconazol (K, la 5-fluorocitosina (5-FC y la rifampicina. Las 3 cepas estudiadas tuvieron las siguientes concentraciones inhibitorias mínimas (MIC (mcg/ml A: 0.09-0.18; K: 0.001-0.007; 5-FC: 62.5-250 y R: 40-80. Las concentraciones fungicidas mínimas (MFC resultaron más altas que las MICs correspondientes. En el caso de la 5-FC no se obtuvo una cifra MFC precisa (> 500 mcg/ml. La combinación de K más A mostró ser sinérgica al combinarse las drogas en relación 1:1 y 1:5 de los MICs respectivos. R (40 mcg/ml se mostró antagonista del K. Los resultados indican que la combinación A + K pudiera constituir un adecuado régimen terapéutico en ciertos pacientes.

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

    Science.gov (United States)

    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.

  7. Family system characteristics and psychological adjustment to cancer susceptibility genetic testing : a prospective study

    NARCIS (Netherlands)

    van Oostrom, I.; Meijers-Heijboer, H.; Duivenvoorden, H. J.; Brocker-Vriends, A. H. J. T.; van Asperen, C. J.; Sijmons, R. H.; Seynaeve, C.; Van Gool, A. R.; Klijn, J. G. M.; Tibben, A.

    This study examined prospectively the contribution of family functioning, differentiation to parents, family communication and support from relatives to psychological distress in individuals undergoing genetic susceptibility testing for a known familial pathogenic BRCA1/2 or Hereditary nonpolyposis

  8. Auditory Tests for the Early Detection of Noise-Susceptible Individuals - A Literature Study

    National Research Council Canada - National Science Library

    Vos, Joos

    2005-01-01

    ... of persons who are less susceptible to noise. The Netherlands Ministry of Defense contracted TNO Human Factors to investigate whether, at present, reliable auditory tests are available to determine at an early stage (i.e...

  9. A Novel Hypoxia Challenge Test Demonstrates Cardiovascular and Pulmonary Susceptibility to Acrolein Gas in Hypertensive Rats.

    Science.gov (United States)

    High levels of air pollution increase the risk of cardiovascular morbidity and mortality, especially in susceptible populations including those with hypertension. Stress tests are useful for manifesting latent effects of exposure, particularly at low concentrations, often when no...

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

    Science.gov (United States)

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

    2016-10-01

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

  11. Routine disc diffusion antimicrobial susceptibility testing of Clostridium difficile and association with PCR ribotype 027

    DEFF Research Database (Denmark)

    Holt, H M; Danielsen, T K; Justesen, U S

    2015-01-01

    Reduced susceptibility to metronidazole and vancomycin in Clostridium difficile has been reported, which emphasises the need for simple antimicrobial susceptibility testing methods. The aim of this study was to apply a published disc diffusion method and zone diameter breakpoint correlates...... to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) epidemiological minimum inhibitory concentration (MIC) cut-off values in a routine setting. Metronidazole and vancomycin zone diameters from 2702 isolates were recorded. Fifteen isolates had a metronidazole zone diameter below...... the published breakpoint (vancomycin zone diameter below the published breakpoint (

  12. Antifungal potential of thyme essential oil as a preservative for storage of wheat seeds

    OpenAIRE

    Anžlovar, Sabina; Likar, Matevž; Dolenc Koce, Jasna

    2017-01-01

    Plant essential oils are potential food preservatives due to their inhibitory effects on bacterial and fungal growth. Antifungal activities of common thyme (Thymus vulgaris) essential oil were tested against endophytic fungi grown from wheat (Triticum aestivum) grain, molecularly identified as Alternaria alternata, Alternaria infectoria, Aspergillus fl avus, Epicoccum nigrum and Fusarium poae. Their susceptibility to thyme essential oil was tested in vitro, and ranged from fungicidal to fu...

  13. Suscetibilidade a antifúngicos de cepas de Candida albicans isoladas de pacientes com estomatite protética Susceptibility to antifungal drugs of Candida albicans strains isolated from patients with denture stomatitis

    Directory of Open Access Journals (Sweden)

    Jéssica Moreira BATISTA

    1999-12-01

    Full Text Available Pacientes portadores de próteses totais, apresentam, com freqüência a chamada estomatite protética, com a qual associa-se Candida albicans determinando a chamada candidíase eritematosa. Assim, procuramos avaliar a suscetibilidade dessa levedura a agentes antifúngicos. A suscetibilidade de dezenove cepas de Candida albicans isoladas de pacientes apresentando estomatite protética foi estudada frente a: um derivado poliênico representado, pela anfotericina B (AnB, e dois derivados azóicos, cetoconazol e miconazol. A atividade antifúngica foi estudada a partir da determinação da concentração inibitória mínima (CIM e da concentração fungicida mínima (CFM, pela técnica de diluição em ágar. Os resultados obtidos, mostraram baixos valores de CIMs e CFMs (mg/ml para a AnB frente a todas as leveduras. Para o miconazol e o cetoconazol, foram observadas CIMs invariavelmente £ 4,00 mg/ml; para as CFMs, foram obtidos valores ³ 16,00 mg/ml frente a maioria das cepas. Conclui-se que a AnB apresentou maior ação fungicida in vitro enquanto os azóis demonstraram ação fungistática mas não fungicida. Acreditamos que a pesquisa de novas drogas, principalmente de uso tópico ainda é necessária, a fim de se tratar, com sucesso, a candidíase eritematosa, comumente observada nas chamadas estomatites protéticas.Users of total prosthesis present in general a high frequency of the so called denture stomatitis, associated to erythematous candidiasis. So, we evaluated the susceptibility of oral yeast to three antifungal agents. Strains of Candida albicans isolated from patients with denture stomatitis were evaluated in relation to the susceptibility of the antifungal drugs as amphotericin B (polyenic derivatives, and azole agents as ketoconazole and miconazole. The antifungal activity was evaluated, and the minimal inhibitory concentration (MIC and minimal fungicide concentration (MFC were determined utilizing the agar dilution method. The

  14. Correlation of Etest and Neo-Sensitabs diffusion assays on Mueller-Hinton-methylene blue agar with broth microdilution reference method (CLSI-M27-A2) for testing susceptibilities of Cryptococcus neoformans to amphotericin B and fluconazole.

    Science.gov (United States)

    Ochiuzzi, Maria Eugenia; Santiso, Gabriela María; Arechavala, Alicia Irene

    2010-09-01

    Cryptococcus neoformans causes disseminated infection in 7-8% of HIV positive patients admitted to Hospital F. J. Muñiz in Buenos Aires. Meningoencephalitis is the most frequent clinical manifestation and is one of the main causes of death in those patients with AIDS. The standard treatment for this mycosis consists of amphotericin B followed by fluconazole until two successive cultures of CFS are negative. Although resistance to these drugs is infrequent, minimal inhibitory concentrations (MIC) of some antifungals can be high. Since it is important to know the susceptibility levels of this fungus to the antifungal drugs usually employed in our institution, we analyzed the susceptibility test results of C. neoformans with two diffusion methods (Etest and NeoSensitabs tablets) employing Mueller-Hinton agar with 2% glucose and 0.5 microg/ml methylene blue. These results were compared with MICs obtained through the use of the broth microdilution reference method (CLSI). Results showed good agreement with the reference method, with no very major errors and only two major errors for fluconazole using NeoSensitabs tablets. For all the above mentioned, we confirm the usefulness of Mueller-Hinton agar to evaluate C. neoformans susceptibility to amphotericin B and fluconazole with these two agar diffusion methods.

  15. Adherence to HeLa cells, typing by killer toxins and susceptibility to antifungal agents of Candida dubliniensis strains Adesão a células HeLa, tipagem pelas toxinas "killer" e sensibilidade a antifúngicos de cepas de Candida dubliniensis

    Directory of Open Access Journals (Sweden)

    Gismari Miranda da Silva

    2007-03-01

    Full Text Available The aim of this study was to evaluate the adherence capability to HeLa cells, the susceptibility to killer toxins and the in vitro susceptibility to antifungal agents (eTest? method - AB Biodisk, Solna, Sweden of 9 Candida dubliniensis isolates recovered from HIV+ and AIDS patients. The adherence test was strongly positive for strain ATCC 777 and positive for all other strains. Typing by killer toxins revealed two different biotypes among the 9 isolates studied: 888 and 688. Only biotype 688 (ATCC 777 was susceptible to the K2 toxin. There was a significant inverse correlation between adherence and killer toxin susceptibility (r = -0.8525 - p = 0.0035. No strains presented resistance to fluconazole, itraconazole, ketoconazole, voriconazole, flucytosine or amphotericin-B. With the exception of ATCC 777, all the other isolates presented similar behavior.O objetivo do presente trabalho foi avaliar o comportamento de cepas de Candida dubliniensis recuperadas de pacientes HIV+ e com AIDS por meio da pesquisa de capacidade de adesão a células HeLa, susceptibilidade a toxinas "Killer" e resistência in vitro a antifúngicos (eTest® AB Biodisk, Solna, Suécia. O ensaio de adesão foi fortemente aderente para a amostra padrão ATCC 777, e aderente para os demais isolados. Os testes de tipagem das amostras frente às cepas-padr��o produtoras de toxinas "Killer" mostraram dois biótipos diferentes dos 9 isolados estudados: 888 e 688. Somente o biótipo 688 (ATCC 777 de C. dubliniensis foi sensível à toxina K2. Houve correlação inversa significativa entre adesão e sensibilidade a toxinas "killer" (r = -0,8525 - p = 0,0035. Em relação à pesquisa de resistência a antifúngicos, as amostras de C. dubliniensis foram sensíveis ao fluconazol, itraconazol, cetoconazol, voriconazol, à flucitosina e anfotericina B. Com exceção da amostra ATCC 777, todas as demais mostraram comportamento similar.

  16. Bacterial Cytological Profiling (BCP as a Rapid and Accurate Antimicrobial Susceptibility Testing Method for Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    D.T. Quach

    2016-02-01

    Full Text Available Successful treatment of bacterial infections requires the timely administration of appropriate antimicrobial therapy. The failure to initiate the correct therapy in a timely fashion results in poor clinical outcomes, longer hospital stays, and higher medical costs. Current approaches to antibiotic susceptibility testing of cultured pathogens have key limitations ranging from long run times to dependence on prior knowledge of genetic mechanisms of resistance. We have developed a rapid antimicrobial susceptibility assay for Staphylococcus aureus based on bacterial cytological profiling (BCP, which uses quantitative fluorescence microscopy to measure antibiotic induced changes in cellular architecture. BCP discriminated between methicillin-susceptible (MSSA and -resistant (MRSA clinical isolates of S. aureus (n = 71 within 1–2 h with 100% accuracy. Similarly, BCP correctly distinguished daptomycin susceptible (DS from daptomycin non-susceptible (DNS S. aureus strains (n = 20 within 30 min. Among MRSA isolates, BCP further identified two classes of strains that differ in their susceptibility to specific combinations of beta-lactam antibiotics. BCP provides a rapid and flexible alternative to gene-based susceptibility testing methods for S. aureus, and should be readily adaptable to different antibiotics and bacterial species as new mechanisms of resistance or multidrug-resistant pathogens evolve and appear in mainstream clinical practice.

  17. Parasiticidal, antifungal and antibacterial activities of Onosma ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... neubauer counting chamber and IC50 values of compounds pos- sessing antileishmanial activity were calculated by Software Ezfit. 5.03 Perella Scientific. IC50 values of different fractions against the test pathogen are mentioned in Table 1. Antifungal activity. Similarly antifungal activity was evaluated by ...

  18. Perceived susceptibility and self-protective behavior: a field experiment to encourage home radon testing

    International Nuclear Information System (INIS)

    Weinstein, N.D.; Sandman, P.M.; Roberts, N.E.

    1991-01-01

    Tested in a field experiment (N = 647) the hypothesis that perceptions of personal susceptibility are important in decisions to test one's home for radioactive radon gas. Experimental group subjects received a personal telephone call to tell them they lived in a high-risk area and a personal letter to reinforce the telephone message. After the intervention, experimental subjects were significantly more likely than minimal-treatment subjects to acknowledge the possibility of high radon levels in their homes. Perceptions of susceptibility and illness severity were significantly correlated with orders of radon test kits and with testing intentions. Nevertheless, there were no differences between groups in test orders or intentions. Results are discussed in terms of the difficulty of getting people to acknowledge susceptibility and the factors other than risk perceptions that influence self-protective behavior

  19. Selection of media for antimicrobial susceptibility testing of fish pathogenic bacteria

    DEFF Research Database (Denmark)

    Dalsgaard, Inger

    2001-01-01

    The available data concerning antimicrobial susceptibility testing of fish pathogens showed that there is no consensus to the basal medium currently being employed. Different media recommended for susceptibility testing of human pathogens (Mueller-Hinton Agar, Tryptone Soya Agar, Antibiotic Medium...... normally used for cultivation of pathogens with specific growth requirements like Flavobacterium species and Renibacterium salmoninarum have been used for susceptibility testing. The Mueller-Hinton Agar and different modifications of this medium was used most frequently in published studies on resistant...... 3, Diagnostic Sensitivity Test Agar) have been used in addition to media (Brain Heart Infusion Agar, Heart Infusion Agar, Columbia Blood Agar) normally utilized for cultivating fastidious bacteria. When testing marine pathogens, sodium chloride or seawater has been included in the media. Media...

  20. Selection of media for antimicrobial susceptibility testing of fish pathogenic bacteria

    DEFF Research Database (Denmark)

    Dalsgaard, Inger

    2001-01-01

    normally used for cultivation of pathogens with specific growth requirements like Flavobacterium species and Renibacterium salmoninarum have been used for susceptibility testing. The Mueller-Hinton Agar and different modifications of this medium was used most frequently in published studies on resistant......The available data concerning antimicrobial susceptibility testing of fish pathogens showed that there is no consensus to the basal medium currently being employed. Different media recommended for susceptibility testing of human pathogens (Mueller-Hinton Agar, Tryptone Soya Agar, Antibiotic Medium...... 3, Diagnostic Sensitivity Test Agar) have been used in addition to media (Brain Heart Infusion Agar, Heart Infusion Agar, Columbia Blood Agar) normally utilized for cultivating fastidious bacteria. When testing marine pathogens, sodium chloride or seawater has been included in the media. Media...

  1. Selection of media for antimicrobial susceptibility testing of fish pathogenic bacteria

    DEFF Research Database (Denmark)

    Dalsgaard, Inger

    2001-01-01

    The available data concerning antimicrobial susceptibility testing of fish pathogens showed that there is no consensus to the basal medium currently being employed. Different media recommended for susceptibility testing of human pathogens (Mueller-Hinton Agar, Tryptone Soya Agar, Antibiotic Medium...... 3, Diagnostic Sensitivity Test Agar) have been used in addition to media (Brain Heart Infusion Agar, Heart Infusion Agar, Columbia Blood Agar) normally utilized for cultivating fastidious bacteria. When testing marine pathogens, sodium chloride or seawater has been included in the media. Media...... normally used for cultivation of pathogens with specific growth requirements like Flavobacterium species and Renibacterium salmoninarum have been used for susceptibility testing. The Mueller-Hinton Agar and different modifications of this medium was used most frequently in published studies on resistant...

  2. Antifungal activity of essential oils of Origanum vulgare and Rosmarinus officinalis against three Candida albicans strains

    Directory of Open Access Journals (Sweden)

    Delić Dafina N.

    2013-01-01

    Full Text Available Due to general growing resistance and side effects to common antifungal drugs nowadays, there have been many studies reported on the use of herbal essential oils as antifungal agents in recent years. In this study, essential oils of Origanum vulgare and Rosmarinus officinalis (Lamiaceae were examined for their in vitro antifungal activity against three Candida albicans strains (laboratory - CAL, human pulmonary - CAH, and reference ATCC10231-CAR in comparison to Nystatin (0.30 mg/ml and Fluconazole (2 mg/ml as standard antifungal agents. The antifungal activity was evaluated by comparing inhibition zone diameters obtained both by disc-and well-diffusion assays, as well as by comparing MIC and MBC values detected by microdilution assay. Diffusion test results revealed stronger antifungal effect of O. vulgare against all analyzed C. albicans strains identifying CAL strain as the most susceptible one. Inhibition zones ranged from 12.65 to 25.10 mm depending on the concentrations applied. The highest concentrations of Rosemary essential oil (5.00 mg/ml demonstrated activity against two strains: CAL and CAR ATCC 10231 in both diffusion assays applied, while no antifungal activity was recorded against CAH isolate. Microdilution assay showed that both oils demonstrated the same MIC values for all tested strains (0.11 mg/ml, except MIC value against ATCC strain (0.23 mg/ml obtained for Rosemary essential oil. The obtained results indicated that oregano and rosemary essential oils might be highly effective in the natural prevention treatment of candidiasis, although toxicity assays should be previously preformed. [Projekat Ministarstva nauke Republike Srbije, br. 172058

  3. Screening of pharmacologically active small molecule compounds identifies antifungal agents against Candida biofilms

    Directory of Open Access Journals (Sweden)

    Takao eWatamoto

    2015-12-01

    Full Text Available 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 C. 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 9 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

  4. A Simplified Test for Blanching Susceptibility of Copper Alloys

    Science.gov (United States)

    Thomas-Ogbuji, Linus U.; Humphrey, Donald; Setlock, John

    2003-01-01

    GRCop-84 (Cu-8Cr-4Nb) is a dispersion-strengthened alloy developed for space-launch rocket engine applications, as a liner for the combustion chamber and nozzle ramp. Its main advantage over rival alloys, particularly NARloy-Z (Cu-Ag-Zr), the current liner alloy, is in high temperature mechanical properties. Further validation required that the two alloys be compared with respect to service performance and durability. This has been done, under conditions resembling those expected in reusable launch engine applications. GRCop-84 was found to have a superior resistance to static and cyclic oxidation up to approx. 700 C. In order to improve its performance above 700 C, Cu-Cr coatings have also been developed and evaluated. The major oxidative issue with Cu alloys is blanching, a mode of degradation induced by oxidation-reduction fluctuations in hydrogen-fueled engines. That fluctuation cannot be addressed with conventional static or cyclic oxidation testing. Hence, a further evaluation of the alloy substrates and Cu-Cr coating material necessitated our devising a test protocol that involves oxidaton-reduction cycles. This paper describes the test protocols used and the results obtained.

  5. In vitro antifungal susceptibility of Candida spp. isolates from patients with chronic periodontitis and from control patients Suscetibilidade in vitro aos antifúngicos em cepas de Candida spp. isoladas de pacientes com periodontite crônica e de indivíduos controle

    Directory of Open Access Journals (Sweden)

    Cristiane Yumi Koga Ito

    2004-03-01

    Full Text Available Superinfection by Candida can be refractory to conventional periodontal treatments in specific situations, such as in immunocompromised patients. In these cases, the systemic therapy with antifungal drugs could be indicated. The aim of this study was to analyse antifungal susceptibility of Candida spp. strains isolated from chronic periodontitis patients and from control individuals. A total of 39 C. albicans isolates, 9 C. tropicalis, 2 C. glabrata and 5 Candida spp. from control individuals and 30 C. albicans, 3 C. tropicalis and 2 C. glabrata from periodontitis patients were tested. In the control group, 1 isolate of C. glabrata was resistant to ketoconazole and 1 Candida spp. was resistant to amphotericin B, ketoconazole and miconazole. Among the isolates of periodontitis group, 1 (3.33% C. albicans isolate was resistant to flucytosine and ketoconazole. According to the obtained results, it could be concluded that fluconazole was the most effective drug against the several Candida species studied. There were not expressive differences in the susceptibility of isolates from periodontitis patients or from control individuals.Em certas situações, tal como em pacientes imunocomprometidos, superinfecção por Candida pode ocorrer e ser refratária ao tratamento periodontal convencional. Nesses casos, a terapia sistêmica com antifúngicos pode ser indicada. O objetivo deste trabalho foi estudar a suscetibilidade aos antifúngicos de cepas de leveduras do gênero Candida isoladas de pacientes com periodontite crônica e de indivíduos controle. Um total de 39 isolados de C. albicans, 9 de C. tropicalis, 2 de C. glabrata e 5 de Candida spp. provenientes de indivíduos controle e 30 de C. albicans, 3 de C. tropicalis e 2 de C. glabrata de pacientes com periodontite foram testados. No grupo controle, uma amostra de C. glabrata foi resistente ao cetoconazol e uma de Candida spp. mostrou-se resistente a anfotericina B, cetoconazol e miconazol. Dentre

  6. Rubella, rubeola, and mumps in pregnant women: susceptibilities and strategies for testing and vaccinating.

    Science.gov (United States)

    Haas, David M; Flowers, Coy A; Congdon, Christine L

    2005-08-01

    To estimate rubella, rubeola, and mumps (MMR) susceptibilities in pregnant women and determine the percentage not immune to rubeola or mumps, depending on rubella immunity status. A secondary objective was to assess costs of vaccination and testing programs aimed at eliminating these viral susceptibilities to determine an optimal strategy. This was an observational study of women presenting for prenatal care. All women had MMR antibody titers measured. Viral susceptibilities were compared by age, gravidity, parity, and recall of vaccine booster. A logistic regression was performed to assess for predictors of MMR immunity. A cost comparison of different screening and vaccination strategies was performed. Overall, 91 (9.4%) women were susceptible to rubella, 161 (16.5%) to rubeola, and 159 (16.3%) to mumps. Three hundred seventeen (32.6%) were susceptible to at least 1 virus, whereas only 17 (1.7%) were susceptible to all 3. Of the women who were immune to rubella, a large percentage were not immune to either rubeola or mumps (n = 226, 25.6%). Only 74.2% of women who knew they had a booster vaccine were immune to all components of the MMR vaccine. Receiving a booster was predictive of immunity to all 3 viruses. A cost analysis demonstrated that broader screening strategies are more comprehensive and more expensive. The current screening and vaccine program has left many reproductive-aged women susceptible to rubella, rubeola, and mumps infections. Perhaps a more comprehensive viral screening program is needed to ensure immunity.

  7. Clinico-mycological study of dermatophytic infections and their sensitivity to antifungal drugs in a tertiary care center

    Directory of Open Access Journals (Sweden)

    Soniya Mahajan

    2017-01-01

    Conclusion: Inadequate and irregular use of antifungal drugs has led to the emergence of resistant strains, which cause poor treatment outcomes. Thus, it is very important to test for antifungal sensitivity to check for resistance to antifungals.

  8. A fatal case of AIDS-defining meningoencephalitis by C. Neoformans, sensitive to antifungal therapy

    Directory of Open Access Journals (Sweden)

    Mohammad-Khani S

    2010-11-01

    Full Text Available Abstract Cryptococcus neoformans is the most common cause of life threatening meningoencephalitis in HIV-infected patients. Diagnosis is based on tests for cryptoccocal antigen in serum and cerebrospinal fluid, and on culture of the organism. We present a case of AIDS-related cryptococcal meningoencephalitis unresponsive to antifungal combination therapy, despite of evidence of fungal susceptibility in vitro. Significant decreases in cryptococcal antigen titers in serum and cerebrospinal fluid did not correlate with progress in disease and fatal outcome.

  9. Standardization of a broth microdilution susceptibility testing method to determine minimum inhibitory concentrations of aquatic bacteria

    DEFF Research Database (Denmark)

    Miller, R.A.; Walker, R.D.; Carson, J.

    2005-01-01

    antimicrobial susceptibility testing methods for bacterial isolates from aquatic animal species. QC ranges were established for Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658 when testing at 22, 28 and 35 degrees C (E. coli only) for 10 different antimicrobial agents...

  10. Sequence variant classification and reporting: recommendations for improving the interpretation of cancer susceptibility genetic test results.

    NARCIS (Netherlands)

    Plon, S.E.; Eccles, D.M.; Easton, D.F.; Foulkes, W.D.; Genuardi, M.; Greenblatt, M.S.; Hogervorst, F.B.L.; Hoogerbrugge, N.; Spurdle, A.B.; Tavtigian, S.V.

    2008-01-01

    Genetic testing of cancer susceptibility genes is now widely applied in clinical practice to predict risk of developing cancer. In general, sequence-based testing of germline DNA is used to determine whether an individual carries a change that is clearly likely to disrupt normal gene function.

  11. Standard versus biofilm antimicrobial susceptibility testing to guide antibiotic therapy in cystic fibrosis.

    Science.gov (United States)

    Waters, Valerie; Ratjen, Felix

    2017-10-05

    The antibiotics used to treat pulmonary infections in people with cystic fibrosis are typically chosen based on the results of antimicrobial susceptibility testing performed on bacteria traditionally grown in a planktonic mode (grown in a liquid). However, there is considerable evidence to suggest that Pseudomonas aeruginosa actually grows in a biofilm (or slime layer) in the airways of people with cystic fibrosis with chronic pulmonary infections. Therefore, choosing antibiotics based on biofilm rather than conventional antimicrobial susceptibility testing could potentially improve response to treatment of Pseudomonas aeruginosa in people with cystic fibrosis. This is an update of a previously published Cochrane Review. To compare biofilm antimicrobial susceptibility testing-driven therapy to conventional antimicrobial susceptibility testing-driven therapy in the treatment of Pseudomonas aeruginosa infection in people with cystic fibrosis. We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. Most recent search: 19 June 2017.We also searched two ongoing trials registries and the reference lists of relevant articles and reviews. Most recent searches: 24 August 2017 and 05 September 2017. Randomized controlled trials of antibiotic therapy based on biofilm antimicrobial susceptibility testing compared to antibiotic therapy based on conventional antimicrobial susceptibility testing in the treatment of Pseudomonas aeruginosa pulmonary infection in people with cystic fibrosis. Both authors independently selected trials, assessed their risk of bias and extracted data from eligible trials. Additionally, the review authors contacted the trial investigators to obtain further information. The quality of the evidence was assessed using the GRADE criteria. The searches identified two multicentre, randomized, double-blind controlled clinical trials eligible for inclusion

  12. Harmonization of antimicrobial susceptibility testing among veterinary diagnostic laboratories in the five Nordic countries

    DEFF Research Database (Denmark)

    Petersen, A.; Aarestrup, Frank Møller; Hofshagen, Merete

    2003-01-01

    Committee of Clinical Laboratory Standards breakpoints, the percentage of concordant results increased to 98.4% and the performance between laboratories varied between 94.2 and 99.4% concordant results. For E. coli, S., aureus, and Salmonella, all laboratories except one had more than 97% concordant results......A total of 100 bacterial strains (25 Escherichia coli, 25 Salmonella enterica, 25 Staphylococcus aureus, and 25 Enterococcus strains) and four reference strains were tested for susceptibility toward 8-12 antimicrobial agents in 12 veterinary diagnostic laboratories in the five Nordic countries......, whereas for Enterococcus spp., two laboratories had less than 90 % concordant results. Susceptibility testing of Salmonella to fluoroquinolones gave rise to almost 0.5% nonconcordant results and susceptibility testing of S. aureus to vancomycin resulted in that 1.8% of the strains were incorrectly...

  13. Evaluation of a radiometric method for pyrazinamide susceptibility testing of Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Tarrand, J.J.; Spicer, A.D.; Groeschel, D.H.

    1986-01-01

    Pyrazinamide susceptibility testing of Mycobacterium tuberculosis requires an acid environment. By controlling the method of acidification and the quality and quantity of the inoculum, the test can be performed with the BACTEC radiometric system (Johnston Laboratories, Towson, Md.). We acidified BACTEC 7H12 medium with buffered phosphoric acid and adjusted the test inoculum to 1/10 of that usually employed in BACTEC protocols; after 5 days of growth we correctly identified 36 of 36 strains susceptible to 50 micrograms of pyrazinamide per ml. All 18 resistant strains were classified as pyrazinamide resistant. (Susceptibility or resistance had been determined by standard plate assays.) The test was able to detect small resistant populations in artificial mixtures of 1 or 2% resistant bacteria with a susceptible strain (10 mixtures each). We tested 70 M. tuberculosis strains in acidified BACTEC 7H12 medium and by the plate dilution test at pH 5.5. All strains grew in the BACTEC medium, but three strains failed to grow on plates and were not tested further; the results of both methods agreed for the remaining strains

  14. Minimal inhibitory concentration distributions and epidemiological cutoff values of five antifungal agents against Sporothrix brasiliensis.

    Science.gov (United States)

    Almeida-Paes, Rodrigo; Brito-Santos, Fábio; Figueiredo-Carvalho, Maria Helena Galdino; Machado, Ana Caroline Sá; Oliveira, Manoel Marques Evangelista; Pereira, Sandro Antonio; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria

    2017-05-01

    Sporothrix brasiliensis is the most virulent sporotrichosis agent. This species usually responds to antifungal drugs, but therapeutic failure can occur in some patients. Antifungal susceptibility tests have been performed on this species, but no clinical breakpoints (CBPs) are available. In this situation, minimal inhibitory concentration (MIC) distributions and epidemiological cutoff values (ECVs) support the detection of identification of resistant strains. To study the MIC distributions of five antifungal drugs against S. brasiliensis and to propose tentative ECVs. MICs of amphotericin B (AMB), itraconazole (ITR), ketoconazole (KET), posaconazole (POS), and terbinafine (TRB) against 335 S. brasiliensis strains were determined by the Clinical and Laboratory Standards Institute broth microdilution method. The proposed ECV, in µg/mL, for AMB, ITR, KET, POS, and TRB were 4.0, 2.0, 1.0, 2.0, and 0.25, respectively. Percentages of wild-type strains in our population for the above antifungal drugs were 98.48, 95.22, 95.33, 100, and 97.67%, respectively. These ECVs will be useful to detect strains with resistance, to define CBPs, and to elaborate specific therapeutic guidelines for S. brasiliensis. Rational use of antifungals is strongly recommended to avoid the emergence of resistant strains and ensure the therapeutic effectiveness of sporotrichosis.

  15. Minimal inhibitory concentration distributions and epidemiological cutoff values of five antifungal agents against Sporothrix brasiliensis

    Directory of Open Access Journals (Sweden)

    Rodrigo Almeida-Paes

    Full Text Available BACKGROUND Sporothrix brasiliensis is the most virulent sporotrichosis agent. This species usually responds to antifungal drugs, but therapeutic failure can occur in some patients. Antifungal susceptibility tests have been performed on this species, but no clinical breakpoints (CBPs are available. In this situation, minimal inhibitory concentration (MIC distributions and epidemiological cutoff values (ECVs support the detection of identification of resistant strains. OBJECTIVES To study the MIC distributions of five antifungal drugs against S. brasiliensis and to propose tentative ECVs. METHODS MICs of amphotericin B (AMB, itraconazole (ITR, ketoconazole (KET, posaconazole (POS, and terbinafine (TRB against 335 S. brasiliensis strains were determined by the Clinical and Laboratory Standards Institute broth microdilution method. FINDINGS The proposed ECV, in µg/mL, for AMB, ITR, KET, POS, and TRB were 4.0, 2.0, 1.0, 2.0, and 0.25, respectively. Percentages of wild-type strains in our population for the above antifungal drugs were 98.48, 95.22, 95.33, 100, and 97.67%, respectively. MAIN CONCLUSIONS These ECVs will be useful to detect strains with resistance, to define CBPs, and to elaborate specific therapeutic guidelines for S. brasiliensis. Rational use of antifungals is strongly recommended to avoid the emergence of resistant strains and ensure the therapeutic effectiveness of sporotrichosis.

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

    Science.gov (United States)

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

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

  17. Sporothrix schenckii associated with armadillo hunting in Southern Brazil: epidemiological and antifungal susceptibility profiles Sporothrix schenckii relacionado à caça ao tatu no Sul do Brasil: aspectos epidemiológicos e suscetibilidade dos isolados aos antifúngicos

    Directory of Open Access Journals (Sweden)

    Sydney Hartz Alves

    2010-10-01

    Full Text Available INTRODUCTION: Sporotrichosis is the most common subcutaneous mycosis observed in Brazil and it is generally consequent to a little trauma caused by vegetal particles or spines which inoculate the fungi in the subcutaneous area. Although sporotrichosis had been frequently mentioned with armadillo hunting this form has not been widely reported in Brazil until now. In this study we report ten cases of sporotrichosis evolving the armadillo's hunting diagnosed in some towns located in the central and west regions of Rio Grande do Sul State. METHODS: The cases were established based on clinical and classic mycological laboratorial techniques. The susceptibility tests were conducted by microdilution technique according to M38-A2 CLSI documents. RESULTS: Ten cases of sporotrichosis associated with armadillo hunting detected in the State of Rio Grande do Sul were diagnosed by mycological methods. The susceptibility tests of Sporothrix schenckii isolates to antifungal agents itraconazole, ketoconazole and terbinafine showed that all the isolates were susceptible. CONCLUSIONS: The paper discusses some cultural aspects related to hunting of this wild animal as well as possible causes of this unexpected occurrence in southern Brazil.INTRODUÇÃO: A esporotricose constitui-se na micose subcutânea mais frequentemente observada e, na maioria dos casos, a infecção é decorrente de pequenos traumas envolvendo fragmentos vegetais ou espinhos que inoculam o fungo no tecido subcutâneo. Embora frequentemente relacionada a caça a tatus, esta ocorrência tem sido raramente relatada no Brasil. Neste estudo relatamos dez casos envolvendo esta prática, observados em várias cidades das regiões centro e oeste do Estado do Rio Grande do Sul. MÉTODOS: o diagnóstico clínico foi confirmado pelos métodos clássicos de cultura em ágar Mycobiotic, identificação micromorfológica seguida de reversão a fase leveduriforme em ágar BHI. Os testes de suscetibilidade

  18. Children's differential susceptibility to parenting: An experimental test of "for better and for worse".

    Science.gov (United States)

    Slagt, Meike; Dubas, Judith Semon; van Aken, Marcel A G; Ellis, Bruce J; Deković, Maja

    2017-02-01

    Differential susceptibility theory proposes that a subset of individuals exist who display enhanced susceptibility to both negative (risk-promoting) and positive (development-enhancing) environments. This experiment represents the first attempt to directly test this assumption by exposing children in the experimental group to both negative and positive feedback using puppet role-plays. It thereby serves as an empirical test as well as a methodological primer for testing differential susceptibility. Dutch children (N=190, 45.3% girls) between the ages of 4 and 6years participated. We examined whether negative and positive feedback would differentially affect changes in positive and negative affect, in prosocial and antisocial intentions and behavior, depending on children's negative emotionality. Results show that on hearing negative feedback, children in the experimental group increased in negative affect and decreased in positive affect more strongly than children in the control group. On hearing positive feedback, children in the experimental group tended to increase in positive affect and decrease in prosocial behavior. However, changes in response to negative or positive feedback did not depend on children's negative emotionality. Moreover, using reliable change scores, we found support for a subset of "vulnerable" children but not for a subset of "susceptible" children. The findings offer suggestions to guide future differential susceptibility experiments. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Rapid antibiotic susceptibility testing of Mycobacterium tuberculosis : Its utility in resource poor settings

    Directory of Open Access Journals (Sweden)

    Poojary A

    2006-01-01

    Full Text Available Purpose: To compare the rapid colorimetric nitrate reductase based antibiotic susceptibility (CONRAS test performed on Mycobacterium tuberculosis isolates with the conventional method i.e., the proportion method. Methods: One hundred clinical isolates of M. tuberculosis were tested for susceptibility to isoniazid (INH and rifampicin (RIF by the conventional proportion method and CONRAS in Middlebrook 7H9 liquid medium enriched with growth supplements (MB7H9S. Results: The performance of the CONRAS test was evaluated using proportion method as the gold standard. The sensitivity (ability to detect true drug resistance and specificity (ability to detect true drug susceptibility of the CONRAS test to INH was 93.75 and 98.52% and for RIF it was 96.10 and 100% respectively. The mean time for reporting was 6.3 days and the test showed excellent reproducibility. The kappa (k value for INH was 0.92 and for RIF was 0.99, indicating excellent agreement between the two methods. Conclusions: CONRAS test is a rapid and reliable method of drug susceptibility for M. tuberculosis.

  20. [Susceptibility testing of Mycobacterium tuberculosis isolates to primary antituberculous drugs on chocolate agar: a preliminary study].

    Science.gov (United States)

    Coban, Ahmet Yilmaz; Bilgin, Kemal; Akgüneş, Alper; Durupinar, Belma

    2008-07-01

    The aim of this study was to evaluate the use of chocolate agar as an alternative medium instead of Middlebrook 7H10 agar, for the susceptibility testing of Mycobacterium tuberculosis strains against isoniazid (INH), rifampicin (RIF), streptomycin (STR) and ethambutol (ETM). The susceptibility results obtained by chocolate agar were compared with the results of BACTEC 460 TB (Becton Dickinson, Sparks, MD, USA) system which was accepted as the reference method. A total of 25 M. tuberculosis clinical isolates were included to the study and susceptibility testing was performed on malachite green added-chocolate agar with some modifications of proportion method recommended by NCCLS. In our study when comparing the results obtained by chocolate agar with the results of BACTEC 460 TB system, the concordance rates for INH, STR, RIF and ETM were found as 88%, 88%, 84% and 72%, respectively. The specificity, sensitivity, positive and negative predictive values of susceptibility testing on chocolate agar have been detected as 82.3%, 100%, 72.7% and 100% for INH; 78.5%, 100%, 78.5% and 100% for RIF; 83.3%, 84.2%, 94.1% and 62.5% for STR; 25%, 94.1%, 72.7% and 66.6% for ETM, respectively. The results of the susceptibility testing performed on chocolate agar were obtained on the 21st day of incubation for all isolates. In conclusion, the data from our study suggested that chocolate agar can be used as an alternative medium for the susceptibility testing of M. tuberculosis, however, further studies with more isolates are needed for the standardisation of the method.

  1. Evaluation of susceptibility of high strength steels to delayed fracture by using cyclic corrosion test and slow strain rate test

    International Nuclear Information System (INIS)

    Li Songjie; Zhang Zuogui; Akiyama, Eiji; Tsuzaki, Kaneaki; Zhang Boping

    2010-01-01

    To evaluate susceptibilities of high strength steels to delayed fracture, slow strain rate tests (SSRT) of notched bar specimens of AISI 4135 with tensile strengths of 1300 and 1500 MPa and boron-bearing steel with 1300 MPa have been performed after cyclic corrosion test (CCT). During SSRT the humidity around the specimen was kept high to keep absorbed diffusible hydrogen. The fracture stresses of AISI 4135 steels decreased with increment of diffusible hydrogen content which increased with CCT cycles. Their delayed fracture susceptibilities could be successfully evaluated in consideration of both influence of hydrogen content on mechanical property and hydrogen entry.

  2. Change of antibiotic susceptibility testing guidelines from CLSI to EUCAST: influence on cumulative hospital antibiograms.

    Directory of Open Access Journals (Sweden)

    Aline Wolfensberger

    Full Text Available OBJECTIVE: We studied whether the change in antibiotic susceptibility testing (AST guidelines from CLSI to EUCAST influenced cumulative antibiograms in a tertiary care hospital in Switzerland. METHODS: Antibiotic susceptibilities of non-duplicate isolates collected within a one-year period before (period A and after (period B changing AST interpretation from CLSI 2009 to EUCAST 1.3 (2011 guidelines were analysed. In addition, period B isolates were reinterpreted according to the CLSI 2009, CLSI 2013 and EUCAST 3.1 (2013 guidelines. RESULTS: The majority of species/drug combinations showed no differences in susceptibility rates comparing periods A and B. However, in some gram-negative bacilli, decreased susceptibility rates were observed when comparing CLSI 2009 with EUCAST 1.3 within period B: Escherichia coli / cefepime, 95.8% (CLSI 2009 vs. 93.1% (EUCAST 1.3, P=0.005; Enterobacter cloacae / cefepime, 97.0 (CLSI 2009 vs. 90.5% (EUCAST 1.3, P=0.012; Pseudomonas aeruginosa / meropenem, 88.1% (CLSI 2009 vs. 78.3% (EUCAST 1.3, P=0.002. These differences were still evident when comparing susceptibility rates according to the CLSI 2013 guideline with EUCAST 3.1 guideline. For P. aeruginosa and imipenem, a trend towards a lower antibiotic susceptibility rate in ICUs compared to general wards turned into a significant difference after the change to EUCAST: 87.9% vs. 79.8%, P=0.08 (CLSI 2009 and 86.3% vs. 76.8%, P=0.048 (EUCAST 1.3. CONCLUSIONS: The change of AST guidelines from CLSI to EUCAST led to a clinically relevant decrease of susceptibility rates in cumulative antibiograms for defined species/drug combinations, particularly in those with considerable differences in clinical susceptibility breakpoints between the two guidelines.

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

    Science.gov (United States)

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

    2016-08-01

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

  4. Antimicrobial susceptibility testing of bovine digital dermatitis treponemes identifies macrolides for in vivo efficacy testing.

    Science.gov (United States)

    Evans, N J; Brown, J M; Hartley, C; Smith, R F; Carter, S D

    2012-12-07

    Digital dermatitis (DD) is a major infectious lameness of dairy cattle and sheep considered to be caused by treponemes. The aim of this study was to identify antibiotics effective against DD treponemes that might be useful in the treatment of ruminant DD in the future or to identify antibiotics useful in isolation studies. Here, a microdilution method was used to identify in vitro antimicrobial susceptibility of treponemes cultured from DD lesions to eight relevant antibiotics. DD treponemes exhibited highest susceptibility to amoxicillin, azithromycin and gamithromycin. Unfortunately, amoxicillin whilst having potential for DD treatment in other animals (e.g. sheep) would require milk withhold periods in dairy cattle. DD treponemes were not particularly susceptible to two cephalosporins: cefalexin and ceftiofur, which do not require milk withhold. The bacteria demonstrated low susceptibility to trimethoprim and especially colistin suggesting these antimicrobials may be particularly useful in isolation of DD treponemes. The most promising high susceptibility results for macrolides indicate a rationale to consider veterinary licensed macrolides as DD treatments. Furthermore, given the DD treponeme antibiotic susceptibility similarities to established treatments for human treponematoses, identification of treponemacidal, long acting β-lactam analogues not requiring milk withhold may allow for development of a successful treatment for dairy cattle DD. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Suscetibilidade a antifúngicos in vitro de Candida spp. em pacientes do Hospital Universitário Regional de Maringá-PR Antifungal susceptibility of Candida spp. in vitro among patients from Regional University Hospital of Maringá-PR

    Directory of Open Access Journals (Sweden)

    Fernanda de Oliveira Demitto

    2012-10-01

    Full Text Available INTRODUÇÃO: No ambiente hospitalar, são frequentes as infecções por leveduras do gênero Candida spp., o que torna esse assunto um importante alvo de estudos. OBJETIVO: Avaliar o perfil de suscetibilidade aos antifúngicos de espécies de Candida de pacientes internados no Hospital Universitário Regional de Maringá-PR (HURM. MATERIAL E MÉTODOS: As amostras foram submetidas ao teste de microdiluição em caldo (MD, segundo o documento M27-A3 para determinação da concentração inibitória mínima (CIM, e ao teste de difusão em disco de acordo com o documento M44-A2, ambos do Clinical Laboratory Standarts Institute (CLSI. RESULTADOS E DISCUSSÃO: Foram obtidos 91 isolados provenientes de amostras de urina, hemocultura, ponta de cateter, secreção orotraqueal, entre outros, sendo 38 Candida albicans, 23 C. tropicalis, 16 C. gabrata, 10 C. parapsilosis e quatro C. krusei. Dos antifúngicos testados, anfotericina B, voriconazol e anidulafungina foram os mais eficazes. CONCLUSÃO: A comparação entre as metodologias de microdiluição em caldo e disco difusão (DD mostrou boa correlação para fluconazol para a maioria das espécies de Candida spp., sendo possível destacar que a DD é útil para triagem dos principais antifúngicos usados na prática clínica. No entanto, casos de resistência detectados por DD devem ser confirmados por meio do método de MD, evitando, assim, resultados falsos resistentes, melhorando a eficácia e a segurança do tratamento.INTRODUCTION: Due to the ubiquity of nosocomial yeast infections of the genus Candida spp., studies in this area have become increasingly relevant. OBJECTIVE: To evaluate the antifungal Candida spp. susceptibility profile of hospitalized patients from the Regional University Hospital of Maringá-PR (HURM. MATERIAL AND METHODS: The samples were submitted to broth microdilution test (MD according to protocol M27-A3 in order to determine the minimum inhibitory concentration (MIC and disk

  6. Comparison of manual mycobacteria growth indicator tube and epsilometer test with agar proportion method for susceptibility testing of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    N Karabulut

    2014-01-01

    Full Text Available Background and Objectives: Antimycobacterial susceptibility tests take weeks, and delayed therapy can lead to spread of Mycobacterium tuberculosis. Therefore, rapid, accurate and cost-effective methods are required for proper therapy selection. In this study, the Mycobacteria growth indicator tube (MGIT and epsilometer test (Etest methods were compared to the agar proportion method for susceptibility testing of Mycobacterium tuberculosis. Materials and Methods: The susceptibility tests against isoniazid (INH, rifampin (RIF, streptomycin (STM and ethambutol (ETM of 51 M. tuberculosis complex isolates were analyzed by the MGIT, Etest and agar proportion methods. Results: The concordance between MGIT/Etest and agar proportion methods was 98% for INH and 100% for RIF, STM, ETM. There were not statistically significant differences in results of the susceptibility tests between MGIT/Etest and the reference agar proportion method. Conclusion: The results have shown that MGIT and Etest methods can be used instead of the agar proportion method, because these two methods are more rapid and easier than the agar proportion method.

  7. Antifungal activity of topical microemulsion containing a thiophene derivative

    Directory of Open Access Journals (Sweden)

    Geovani Pereira Guimarães

    2014-06-01

    Full Text Available 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.

  8. Evaluation of rapid radiometric method for drug susceptibility testing of Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Siddiqi, S.H.; Libonati, J.P.; Middlebrook, G.

    1981-01-01

    A total of 106 isolates of Mycobacterium tuberculosis were tested for drug susceptibility by the conventional 7H11 plate method and by a new rapid radiometric method using special 7H12 liquid medium with 14 C-labeled substrate. Results obtained by the two methods were compared for rapidity, sensitivity, and specificity of the new test method. There was 98% overall agreement between the results obtained by the two methods. Of a total of 424 drug tests, only 8 drug results did not agree, mostly in the case of streptomycin. This new procedure was found to be rapid, with 87% of the tests results reportable within 4 days and 98% reportable within 5 days as compared to the usual 3 weeks required with the conventional indirect susceptibility test method. The results of this preliminary study indicate that the rapid radiometric method seems to have the potential for routine laboratory use and merits further investigations

  9. Comparison of E-test with other conventional susceptibility testing methods for ciprofloxacin and gentamicin against gram negative enteric bacilli.

    Science.gov (United States)

    Ogbolu, D O; Terry-Alli, O A; Daini, O A; Olabiyi, F A; Igharo, E A

    2012-06-01

    Increasing antibiotic resistance in Gram negative bacteria has led to the need for a faster and reliable method for determining antimicrobial susceptibility testing. In a resource poor setting like ours, it's also important to look for methods that will be clinically and economically beneficial to the patient. This study was aimed at evaluating the Epsilometer test (E-test) and conventional methods for determining antimicrobial susceptibility of isolates of Gram-negative enteric bacteria to ciprofloxacin and gentamicin. Disc diffusion, E-test, broth dilution and agar dilution methods were performed on 54 bacterial isolates. Using the E-test, 88.9% of bacterial isolates were resistant to ciprofloxacin, 92.6% were resistant using broth microdilution, 96.3% were resistant using agar dilution and 72.2% were resistant using disc diffusion. Minimum inhibitory concentration (MIC50) of isolates for gentamicin showed significant difference for all the techniques (p 0.05). Both E-test and broth dilution methods showed high levels of agreement (p > 0.05), there were low levels of agreement between E-test and agar dilution method (p < 0.05), especially at MIC50. The E-test can therefore be considered a reliable method to determine antimicrobial susceptibility testing and it gives results which are at least as accurate as those obtained by the broth dilution method.

  10. Interpretive criteria for mupirocin susceptibility testing of Staphylococcus spp. using CLSI guidelines.

    LENUS (Irish Health Repository)

    Creagh, S

    2012-02-03

    Mupirocin is an antimicrobial agent commonly used to treat staphylococcal infection or to eliminate persistent carriage. To date, interpretive criteria have not been established to define susceptibility or resistance when performing mupirocin susceptibility testing. In this evaluation, using CLSI guidelines, a total of 502 staphylococci comprising 219 methicillin-sensitive Staphylococcus aureus, 222 methicillin-resistant S. aureus and 61 coagulase-negative staphylococci are tested by broth microdilution, disc diffusion and E-test. Disc diffusion using 5 microg mupirocin discs was found to be a reliable method to distinguish susceptible and resistant strains. Minimum inhibitory concentration (MIC) determination was required to differentiate low-level and high-level resistance to mupirocin. E-test was found to be an accurate alternative to broth microdilution for the routine determination of MIC values of staphylococci to mupirocin. Broth microdilution and disc-diffusion results were plotted on a scattergram, and error rates were calculated. No errors were found using susceptibility criteria of < 4 microg\\/mL (MIC) and > 19 mm (zone diameter).

  11. Alignment of new tuberculosis drug regimens and drug susceptibility testing: a framework for action

    NARCIS (Netherlands)

    Wells, William A.; Boehme, Catharina C.; Cobelens, Frank G. J.; Daniels, Colleen; Dowdy, David; Gardiner, Elizabeth; Gheuens, Jan; Kim, Peter; Kimerling, Michael E.; Kreiswirth, Barry; Lienhardt, Christian; Mdluli, Khisi; Pai, Madhukar; Perkins, Mark D.; Peter, Trevor; Zignol, Matteo; Zumla, Alimuddin; Schito, Marco

    2013-01-01

    New tuberculosis drug regimens are creating new priorities for drug susceptibility testing (DST) and surveillance. To minimise turnaround time, rapid DST will need to be prioritised, but developers of these assays will need better data about the molecular mechanisms of resistance. Efforts are

  12. Cost-effectiveness of rapid susceptibility testing against second-line drugs for tuberculosis

    NARCIS (Netherlands)

    Dowdy, D. W.; van't Hoog, A.; Shah, M.; Cobelens, F.

    2014-01-01

    Drug susceptibility testing (DST) against second-line tuberculosis drugs (SLDs) is essential for improving outcomes among multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) cases. To evaluate the potential cost-effectiveness of rapid DST for SLDs. We constructed a

  13. New recommendations for disk diffusion antimicrobial susceptibility tests for methicillin-resistant (heteroresistant) staphylococci.

    Science.gov (United States)

    McDougal, L K; Thornsberry, C

    1984-01-01

    The agar disk diffusion susceptibility test was reevaluated for its ability to discriminate between susceptible and resistant Staphylococcus aureus (128 strains) and coagulase-negative staphylococci (19 strains) when tested with methicillin, oxacillin, and nafcillin. The results show that the current recommendations for disk potencies and interpretive zone diameters do not fit well with MIC correlates that we now recommend. Based on data from this study, we suggest that these parameters of the test be changed. For methicillin, we recommend a 10-micrograms disk with breakpoints of less than or equal to 11 mm (greater than or equal to 16 micrograms/ml) to indicate resistance and greater than or equal to 15 mm (less than or equal to 4 micrograms/ml) to indicate susceptibility. For oxacillin and nafcillin, we recommend 4-micrograms disks with breakpoints of less than or equal to 12 mm (greater than or equal to 8 micrograms/ml) to indicate resistance and greater than or equal to 16 mm (less than or equal to 2 micrograms/ml) to indicate susceptibility. MIC breakpoints were from a broth microdilution system which used a medium containing salt. If one of these three penicillins were to be selected for routine tests, we would recommend oxacillin, based on our data, but we recognize that this may depend upon the population of staphylococci within a particular hospital. Images PMID:6562125

  14. Simple Sample Preparation Method for Direct Microbial Identification and Susceptibility Testing From Positive Blood Cultures

    Directory of Open Access Journals (Sweden)

    Hong-wei Pan

    2018-03-01

    Full Text Available Rapid identification and determination of the antibiotic susceptibility profiles of the infectious agents in patients with bloodstream infections are critical steps in choosing an effective targeted antibiotic for treatment. However, there has been minimal effort focused on developing combined methods for the simultaneous direct identification and antibiotic susceptibility determination of bacteria in positive blood cultures. In this study, we constructed a lysis-centrifugation-wash procedure to prepare a bacterial pellet from positive blood cultures, which can be used directly for identification by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS and antibiotic susceptibility testing by the Vitek 2 system. The method was evaluated using a total of 129 clinical bacteria-positive blood cultures. The whole sample preparation process could be completed in <15 min. The correct rate of direct MALDI-TOF MS identification was 96.49% for gram-negative bacteria and 97.22% for gram-positive bacteria. Vitek 2 antimicrobial susceptibility testing of gram-negative bacteria showed an agreement rate of antimicrobial categories of 96.89% with a minor error, major error, and very major error rate of 2.63, 0.24, and 0.24%, respectively. Category agreement of antimicrobials against gram-positive bacteria was 92.81%, with a minor error, major error, and very major error rate of 4.51, 1.22, and 1.46%, respectively. These results indicated that our direct antibiotic susceptibility analysis method worked well compared to the conventional culture-dependent laboratory method. Overall, this fast, easy, and accurate method can facilitate the direct identification and antibiotic susceptibility testing of bacteria in positive blood cultures.

  15. Rapid bacterial antibiotic susceptibility test based on simple surface-enhanced Raman spectroscopic biomarkers

    Science.gov (United States)

    Liu, Chia-Ying; Han, Yin-Yi; Shih, Po-Han; Lian, Wei-Nan; Wang, Huai-Hsien; Lin, Chi-Hung; Hsueh, Po-Ren; Wang, Juen-Kai; Wang, Yuh-Lin

    2016-03-01

    Rapid bacterial antibiotic susceptibility test (AST) and minimum inhibitory concentration (MIC) measurement are important to help reduce the widespread misuse of antibiotics and alleviate the growing drug-resistance problem. We discovered that, when a susceptible strain of Staphylococcus aureus or Escherichia coli is exposed to an antibiotic, the intensity of specific biomarkers in its surface-enhanced Raman scattering (SERS) spectra drops evidently in two hours. The discovery has been exploited for rapid AST and MIC determination of methicillin-susceptible S. aureus and wild-type E. coli as well as clinical isolates. The results obtained by this SERS-AST method were consistent with that by the standard incubation-based method, indicating its high potential to supplement or replace existing time-consuming methods and help mitigate the challenge of drug resistance in clinical microbiology.

  16. Mycobacterium abscessus subsp. abscessus Lung Disease: Drug Susceptibility Testing in Sputum Culture Negative Conversion

    Directory of Open Access Journals (Sweden)

    Takehiko Kobayashi

    2018-01-01

    Full Text Available Background: Among Mycobacterium abscessus complex infections, patients with M. abscessus subsp. abscessus (MAA lung disease are difficult to treat and no standard therapy has been established. Few reports have investigated the drug susceptibility of these strains. We retrospectively investigated how in vitro drug susceptibility testing (DST of MAA affects the induction of sputum conversion using pharmacotherapy. Methods: Patients with MAA lung disease diagnosed and treated between 2010 and 2014 at our hospital were enrolled and divided into Group A (sputum conversion without relapse within 1 year and Group B (persistent positive cultured or negative conversion with relapse. MAA was identified in M. abscessus using sequence with genotyping, and DST of MAA was performed. Results: We assessed 23 patients (9 males and 14 females. There were 8 patients in Group A and 15 in Group B. Higher prevalence of susceptible isolates for clarithromycin (CAM susceptibility on day 14 was noted in Group A than in Group B (P = 0.03 and no significant difference observed in the two groups for other drugs. Conclusions: In vitro DST of MAA, especially CAM susceptibility on day 14, affected the results of negative conversion. No other drugs were found to affect sputum culture negative conversion.

  17. Microbial colonization of irradiated pathogenic yeast to catheter surfaces: Relationship between adherence, cell surface hydrophobicity, biofilm formation and antifungal susceptibility. A scanning electron microscope analysis.

    Science.gov (United States)

    Farrag, Hala Abdallah; A-Karam El-Din, Alzahraa; Mohamed El-Sayed, Zeinab Galal; Abdel-Latifissa, Soheir; Kamal, Mona Mohamed

    2015-06-01

    Technological advances such as long-term indwelling catheters have created milieu in which infections are a major complication. Thus it is essential to be able to recognize, diagnose, and treat infections occurring in immunocompromised patients. Adherence assay and quantitation of biofilms was performed by a spectrophotometric method, hydrophobicity was evaluated by adhesion to p-xylene. The minimum inhibitory concentration (MIC) of Nystatin was carried out by a well dilution method. Out of 100 bladder cancer patients, 23 pathogenic yeast isolates were identified. The samples were taken from urinary catheters and urine collected from their attached drainage bags. Pathogenic yeast identified were species of Candida, Cryptococcus, Saccharomyces, Blastoschizomyces, Trichosporn, Hansenula, Prototheca and Rhodotorula. With the exception of Rhodotorula minuta, the yeast were sensitive to the antimycotic agent (Nystatin) used before and after in vitro gamma irradiation at 24.41 Gy as measured by a disc diffusion method. All tested yeast strains were slime producers and showed positive adherence reactions. There were considerable differences in adherence measurements after irradiation. An increase in adherence measurement values (using a spectrophotometric method) after irradiation were detected in four strains whereas eight other strains showed a reduction in their adherence reaction. The cell surface hydrophobicity (CSH) was evaluated by adhesion to p-xylene. Candida tropicalis showed a hydrophobic reaction with an increase in the cell surface hydrophobicity after irradiation. Scanning electron microscopy of irradiated C. tropicalis showed marked abnormalities in cell shape and size with significant reduction in adherence ability at the MIC level of Nystatin (4 μg/ml). More basic research at the level of pathogenesis and catheter substance is needed to design novel strategies to prevent fungal adherence and to inhibit biofilm formation.

  18. Development of a test method for determining the cracking susceptibility of resistance spot welded high strength steel sheets

    OpenAIRE

    Rethmeier, Michael; Suwala, Hubert

    2014-01-01

    In this study a test method for determining the cracking susceptibility of resistance spot welded high strength steel sheets was investigated. The development of a suitable test procedure is based on the External-Loaded Hot Crack Test (PVC-Test). The test modification for resistance spot welding contains a constant tensile force load. The test method for determining the cracking susceptibility was experimentally verified for a high strength steel, a transformation induced plasticity steel (TR...

  19. Consumers' use of web-based information and their decisions about multiplex genetic susceptibility testing.

    Science.gov (United States)

    Kaphingst, Kimberly A; McBride, Colleen M; Wade, Christopher; Alford, Sharon Hensley; Brody, Lawrence C; Baxevanis, Andreas D

    2010-09-29

    Few data exist to inform concerns raised by online direct-to-consumer marketing of genetic susceptibility tests, such as those offered by commercial entities like 23andme, Navigenics, and DNA Direct. The Multiplex Initiative, a population-based study of healthy adults, provides the first opportunity to evaluate how use of a Web-based decision tool that conveyed information about a genetic susceptibility test influenced individuals' test decisions. To inform the ongoing debate over whether individuals offered genetic susceptibility testing without the involvement of a health care provider (eg, through direct-to-consumer testing) can make informed decisions about testing when guided by online decision aids. Participants were 526 members of a large health maintenance organization aged 25 to 40 years old who visited a study website. Multivariate logistic regression models were tested to examine the association of website usage with downstream test decisions. Participants viewed an average of 2.9 of the 4 pages introducing the multiplex test, 2.2 of the 8 pages describing the health conditions, and 3.2 of the 15 pages describing the genes. For each page viewed, participants were more likely to describe their decision-making as easy (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.01-1.07) and to decide to be tested (OR 1.08, 95% CI 1.05-1.11). Healthy adults in this study perceived Web-based genomic information presented using evidence-based communications approaches to be helpful in supporting both decisions to test and not to test. Continued research is needed to ensure that these results generalize to target groups with lower literacy and less Internet savvy.

  20. Antimicrobial susceptibility testing of 230 Helicobacter pylori strains: importance of medium, inoculum, and incubation time

    DEFF Research Database (Denmark)

    Hartzen, S H; Andersen, L P; Bremmelgaard, A

    1997-01-01

    with those of others, and apart from metronidazole, the MIC of which for approximately 25% of the strains tested was >8 microg/ml, resistance was low in Denmark. The situation might, however, quickly change when and if the number of indications for antibiotic therapy for H. pylori infections increase....... Consequently, susceptibility testing of all H. pylori strains is recommended in order to survey the development of resistance, and in our hands the described methodology was relatively easy to perform and the results were easy to read.......No standardized method of susceptibility testing for Helicobacter pylori is currently available, so before a large agar dilution study comprising 230 H. pylori strains belonging to more than 80 genetically different groups was initiated, we performed a relatively small preliminary study...

  1. In vitro susceptibility of amphotericin-B, voriconazole and caspofungin against Candida guilliermondii biofilms, isolated from dentals units water pipes, under different growth phases.

    Science.gov (United States)

    Mazari, W; Boucherit-Otmani, Z; Boucherit, K

    2015-03-01

    The dental units water pipes are a favorable medium for biofilms formation because of the small diameter of the pipe and the duration of water stagnation, but the question which arises is the nature of the biofilms which are formed inside? This article gives a progress report on the nature of this microbial contamination and precisely the fungal biofilms formation by examining their susceptibility to antifungal agents under different growth phases. Sixteen samples of dental units water pipes were taken from public dental clinic and from stomatology unit at the university hospital of Tlemcen (Algeria). The isolated strains were identified by the conventional mycological methods and were analyzed to determine their minimal concentrations inhibiting their growth (planktonic and sessile forms) using three antifungal agents. Five strains type Candida guilliermondii were identified and analyzed for their resistance to antifungal agents. Antifungal susceptibility testing demonstrated the sensitivity of all planktonic Candida guilliermondii cells against amphotericin-B, voriconzole and caspofungin but the sessile cells of these strains revealed a less susceptibility to antifungal agents and even a resistance when the biofilm made mature. Several types of yeast contaminated the dental units water pipes and especially Candida guilliermondii that was the most founded. This specie was susceptible to antifungal agents under planctonic forms and resistance where the biofilm made mature. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  2. Identification and Antimicrobial Susceptibility Testing of Anaerobic Bacteria: Rubik’s Cube of Clinical Microbiology?

    Science.gov (United States)

    Gajdács, Márió; Spengler, Gabriella; Urbán, Edit

    2017-01-01

    Anaerobic bacteria have pivotal roles in the microbiota of humans and they are significant infectious agents involved in many pathological processes, both in immunocompetent and immunocompromised individuals. Their isolation, cultivation and correct identification differs significantly from the workup of aerobic species, although the use of new technologies (e.g., matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, whole genome sequencing) changed anaerobic diagnostics dramatically. In the past, antimicrobial susceptibility of these microorganisms showed predictable patterns and empirical therapy could be safely administered but recently a steady and clear increase in the resistance for several important drugs (β-lactams, clindamycin) has been observed worldwide. For this reason, antimicrobial susceptibility testing of anaerobic isolates for surveillance purposes or otherwise is of paramount importance but the availability of these testing methods is usually limited. In this present review, our aim was to give an overview of the methods currently available for the identification (using phenotypic characteristics, biochemical testing, gas-liquid chromatography, MALDI-TOF MS and WGS) and antimicrobial susceptibility testing (agar dilution, broth microdilution, disk diffusion, gradient tests, automated systems, phenotypic and molecular resistance detection techniques) of anaerobes, when should these methods be used and what are the recent developments in resistance patterns of anaerobic bacteria. PMID:29112122

  3. Identification and Antimicrobial Susceptibility Testing of Anaerobic Bacteria: Rubik's Cube of Clinical Microbiology?

    Science.gov (United States)

    Gajdács, Márió; Spengler, Gabriella; Urbán, Edit

    2017-11-07

    Anaerobic bacteria have pivotal roles in the microbiota of humans and they are significant infectious agents involved in many pathological processes, both in immunocompetent and immunocompromised individuals. Their isolation, cultivation and correct identification differs significantly from the workup of aerobic species, although the use of new technologies (e.g., matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, whole genome sequencing) changed anaerobic diagnostics dramatically. In the past, antimicrobial susceptibility of these microorganisms showed predictable patterns and empirical therapy could be safely administered but recently a steady and clear increase in the resistance for several important drugs (β-lactams, clindamycin) has been observed worldwide. For this reason, antimicrobial susceptibility testing of anaerobic isolates for surveillance purposes or otherwise is of paramount importance but the availability of these testing methods is usually limited. In this present review, our aim was to give an overview of the methods currently available for the identification (using phenotypic characteristics, biochemical testing, gas-liquid chromatography, MALDI-TOF MS and WGS) and antimicrobial susceptibility testing (agar dilution, broth microdilution, disk diffusion, gradient tests, automated systems, phenotypic and molecular resistance detection techniques) of anaerobes, when should these methods be used and what are the recent developments in resistance patterns of anaerobic bacteria.

  4. Genetic Testing for TMEM154 Mutations Associated with Lentivirus Susceptibility in Sheep

    Science.gov (United States)

    Petrik, Dustin T.; Simpson, Barry; Kijas, James W.; Clawson, Michael L.; Chitko-McKown, Carol G.; Harhay, Gregory P.; Leymaster, Kreg A.

    2013-01-01

    In sheep, small ruminant lentiviruses cause an incurable, progressive, lymphoproliferative disease that affects millions of animals worldwide. Known as ovine progressive pneumonia virus (OPPV) in the U.S., and Visna/Maedi virus (VMV) elsewhere, these viruses reduce an animal’s health, productivity, and lifespan. Genetic variation in the ovine transmembrane protein 154 gene (TMEM154) has been previously associated with OPPV infection in U.S. sheep. Sheep with the ancestral TMEM154 haplotype encoding glutamate (E) at position 35, and either form of an N70I variant, were highly-susceptible compared to sheep homozygous for the K35 missense mutation. Our current overall aim was to characterize TMEM154 in sheep from around the world to develop an efficient genetic test for reduced susceptibility. The average frequency of TMEM154 E35 among 74 breeds was 0.51 and indicated that highly-susceptible alleles were present in most breeds around the world. Analysis of whole genome sequences from an international panel of 75 sheep revealed more than 1,300 previously unreported polymorphisms in a 62 kb region containing TMEM154 and confirmed that the most susceptible haplotypes were distributed worldwide. Novel missense mutations were discovered in the signal peptide (A13V) and the extracellular domains (E31Q, I74F, and I102T) of TMEM154. A matrix-assisted laser desorption/ionization–time-of flight mass spectrometry (MALDI-TOF MS) assay was developed to detect these and six previously reported missense and two deletion mutations in TMEM154. In blinded trials, the call rate for the eight most common coding polymorphisms was 99.4% for 499 sheep tested and 96.0% of the animals were assigned paired TMEM154 haplotypes (i.e., diplotypes). The widespread distribution of highly-susceptible TMEM154 alleles suggests that genetic testing and selection may improve the health and productivity of infected flocks. PMID:23408992

  5. Genetic testing for TMEM154 mutations associated with lentivirus susceptibility in sheep.

    Directory of Open Access Journals (Sweden)

    Michael P Heaton

    Full Text Available In sheep, small ruminant lentiviruses cause an incurable, progressive, lymphoproliferative disease that affects millions of animals worldwide. Known as ovine progressive pneumonia virus (OPPV in the U.S., and Visna/Maedi virus (VMV elsewhere, these viruses reduce an animal's health, productivity, and lifespan. Genetic variation in the ovine transmembrane protein 154 gene (TMEM154 has been previously associated with OPPV infection in U.S. sheep. Sheep with the ancestral TMEM154 haplotype encoding glutamate (E at position 35, and either form of an N70I variant, were highly-susceptible compared to sheep homozygous for the K35 missense mutation. Our current overall aim was to characterize TMEM154 in sheep from around the world to develop an efficient genetic test for reduced susceptibility. The average frequency of TMEM154 E35 among 74 breeds was 0.51 and indicated that highly-susceptible alleles were present in most breeds around the world. Analysis of whole genome sequences from an international panel of 75 sheep revealed more than 1,300 previously unreported polymorphisms in a 62 kb region containing TMEM154 and confirmed that the most susceptible haplotypes were distributed worldwide. Novel missense mutations were discovered in the signal peptide (A13V and the extracellular domains (E31Q, I74F, and I102T of TMEM154. A matrix-assisted laser desorption/ionization-time-of flight mass spectrometry (MALDI-TOF MS assay was developed to detect these and six previously reported missense and two deletion mutations in TMEM154. In blinded trials, the call rate for the eight most common coding polymorphisms was 99.4% for 499 sheep tested and 96.0% of the animals were assigned paired TMEM154 haplotypes (i.e., diplotypes. The widespread distribution of highly-susceptible TMEM154 alleles suggests that genetic testing and selection may improve the health and productivity of infected flocks.

  6. Direct susceptibility testing by disk diffusion on clinical samples : a rapid and accurate tool for antibiotic stewardship

    NARCIS (Netherlands)

    Coorevits, L.; Boelens, J.; Claeys, G.

    We compared the accuracy of direct susceptibility testing (DST) with conventional antimicrobial susceptibility testing (AST), both using disk diffusion, on clinical samples. A total of 123 clinical samples (respiratory tract samples, urine, vaginal and abdominal abscess discharges, bile fluid and a

  7. Comparative erythromycin and tylosin susceptibility testing of streptococci from bovine mastitis.

    Science.gov (United States)

    Entorf, Monika; Feßler, Andrea T; Kaspar, Heike; Kadlec, Kristina; Peters, Thomas; Schwarz, Stefan

    2016-10-15

    Tylosin, a 16-membered macrolide, is - besides other indications - used for the treatment of bovine mastitis. So far, there is only limited information available on the tylosin susceptibility of streptococci isolated from mastitis. The aim of the present study was to comparatively investigate 303 streptococci from bovine mastitis, including 101 Streptococcus agalactiae, 100 Streptococcus dysgalactiae and 102 Streptococcus uberis, for their tylosin and erythromycin susceptibility by broth microdilution and agar disk diffusion. Both tests followed the recommendations of the Clinical and Laboratory Standards Institute (CLSI). For erythromycin, the results were interpreted using the CLSI-approved clinical breakpoints. Moreover, erythromycin-resistant isolates were tested for the presence of macrolide resistance genes and for inducible macrolide resistance. In general, both testing methods showed a good correlation for the three streptococcal species, although for the erythromycin susceptibility testing 11 S. uberis isolates fell into the very major error category. All but one of the erythromycin-resistant isolates harbored at least one macrolide resistance gene, with the erm(B) gene being most common. Moreover, single isolates of S. agalactiae and S. dysgalactiae proved to be inducibly macrolide-resistant. Since inducible macrolide resistance can easily switch to constitutive resistance, tylosin should not be used for the treatment of infections caused by inducibly resistant streptococci. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. American Society of Clinical Oncology Policy Statement Update: Genetic and Genomic Testing for Cancer Susceptibility.

    Science.gov (United States)

    Robson, Mark E; Bradbury, Angela R; Arun, Banu; Domchek, Susan M; Ford, James M; Hampel, Heather L; Lipkin, Stephen M; Syngal, Sapna; Wollins, Dana S; Lindor, Noralane M

    2015-11-01

    The American Society of Clinical Oncology (ASCO) has long affirmed that the recognition and management of individuals with an inherited susceptibility to cancer are core elements of oncology care. ASCO released its first statement on genetic testing in 1996 and updated that statement in 2003 and 2010 in response to developments in the field. In 2014, the Cancer Prevention and Ethics Committees of ASCO commissioned another update to reflect the impact of advances in this area on oncology practice. In particular, there was an interest in addressing the opportunities and challenges arising from the application of massively parallel sequencing-also known as next-generation sequencing-to cancer susceptibility testing. This technology introduces a new level of complexity into the practice of cancer risk assessment and management, requiring renewed effort on the part of ASCO to ensure that those providing care to patients with cancer receive the necessary education to use this new technology in the most effective, beneficial manner. The purpose of this statement is to explore the challenges of new and emerging technologies in cancer genetics and provide recommendations to ensure their optimal deployment in oncology practice. Specifically, the statement makes recommendations in the following areas: germline implications of somatic mutation profiling, multigene panel testing for cancer susceptibility, quality assurance in genetic testing, education of oncology professionals, and access to cancer genetic services. © 2015 by American Society of Clinical Oncology.

  9. Development of an Accelerated Test Method for the Determination of Susceptibility to Atmospheric Corrosion

    Science.gov (United States)

    Ambrose, John R.

    1991-01-01

    The theoretical rationale is presented for use of a repetitive cyclic current reversal voltammetric technique for characterization of localized corrosion processes, including atmospheric corrosion. Applicability of this proposed experimental protocol is applied to characterization of susceptibility to crevice and pitting corrosion, atmospheric corrosion and stress corrosion cracking. Criteria upon which relative susceptibility is based were determined and tested using two iron based alloys commonly in use at NASA-Kennedy; A36 (a low carbon steel) and 4130 (a low alloy steel). Practicality of the procedure was demonstrated by measuring changes in anodic polarization behavior during high frequency current reversal cycles of 25 cycles per second with 1 mA/sq cm current density amplitude in solutions containing Cl anions. The results demonstrated that, due to excessive polarization which affects conductivity of barrier corrosion product layers, A36 was less resistant to atmospheric corrosion than its 4130 counterpart; behavior which was also demonstrated during exposure tests.

  10. Antimicrobial susceptibility testing of 230 Helicobacter pylori strains: importance of medium, inoculum, and incubation time

    DEFF Research Database (Denmark)

    Hartzen, S H; Andersen, L P; Bremmelgaard, A

    1997-01-01

    No standardized method of susceptibility testing for Helicobacter pylori is currently available, so before a large agar dilution study comprising 230 H. pylori strains belonging to more than 80 genetically different groups was initiated, we performed a relatively small preliminary study....../spot) as the inoculum and 72 h as the incubation time. A modest inoculum effect was noted for amoxicillin and metronidazole. By the methodology derived from our preliminary study, the susceptibilities of 230 H. pylori strains to six antibiotics were subsequently determined. The results were generally in accord...... with those of others, and apart from metronidazole, the MIC of which for approximately 25% of the strains tested was >8 microg/ml, resistance was low in Denmark. The situation might, however, quickly change when and if the number of indications for antibiotic therapy for H. pylori infections increase...

  11. Successful use of broth microdilution in susceptibility tests for methicillin-resistant (heteroresistant) staphylococci.

    Science.gov (United States)

    Thornsberry, C; McDougal, L K

    1983-01-01

    We studied the broth microdilution antimicrobial susceptibility testing procedure to see whether it could be made reliable for determining resistance of staphylococci to methicillin, oxacillin, nafcillin, and cephalothin. With 45 selected strains of Staphylococcus aureus and 12 selected strains of Staphylococcus epidermidis we found that the addition of 2% NaCl to cation-supplemented Mueller-Hinton broth permitted us to discriminate reliably between resistant and susceptible organisms. A screening test in which resistant staphylococci grew on agar containing 4% NaCl and methicillin (10 micrograms/ml), oxacillin (6 micrograms/ml), or nafcillin (6 micrograms/ml) incubated at 35 degrees C for 24 h (additional 24 h if no growth) was also reliable. In vitro cephalothin resistance occurred in heteroresistant S. aureus but usually did not occur in heteroresistant S. epidermidis. PMID:6643661

  12. Rapid antimicrobial susceptibility testing of clinical isolates by digital time-lapse microscopy

    DEFF Research Database (Denmark)

    Fredborg, M; Rosenvinge, F S; Spillum, E

    2015-01-01

    (168 antimicrobial agent-organism combinations) demonstrated 3.6 % minor, no major and 1.2 % very major errors of the oCelloScope system compared to conventional susceptibility testing, as well as a rapid and correct phenotypic detection of strains with methicillin-resistant Staphylococcus aureus (MRSA......Rapid antimicrobial susceptibility testing (AST) is essential for early and appropriate therapy. Methods with short detection time enabling same-day treatment optimisation are highly favourable. In this study, we evaluated the potential of a digital time-lapse microscope system, the o......CelloScope system, to perform rapid AST. The oCelloScope system demonstrated a very high accuracy (96 % overall agreement) when determining the resistance profiles of four reference strains, nine clinical isolates, including multi-drug-resistant isolates, and three positive blood cultures. AST of clinical isolates...

  13. Fluoromycobacteriophages for Rapid, Specific, and Sensitive Antibiotic Susceptibility Testing of Mycobacterium tuberculosis

    Science.gov (United States)

    Piuri, Mariana; Jacobs, William R.; Hatfull, Graham F.

    2009-01-01

    Rapid antibiotic susceptibility testing of Mycobacterium tuberculosis is of paramount importance as multiple- and extensively- drug resistant strains of M. tuberculosis emerge and spread. We describe here a virus-based assay in which fluoromycobacteriophages are used to deliver a GFP or ZsYellow fluorescent marker gene to M. tuberculosis, which can then be monitored by fluorescent detection approaches including fluorescent microscopy and flow cytometry. Pre-clinical evaluations show that addition of either Rifampicin or Streptomycin at the time of phage addition obliterates fluorescence in susceptible cells but not in isogenic resistant bacteria enabling drug sensitivity determination in less than 24 hours. Detection requires no substrate addition, fewer than 100 cells can be identified, and resistant bacteria can be detected within mixed populations. Fluorescence withstands fixation by paraformaldehyde providing enhanced biosafety for testing MDR-TB and XDR-TB infections. PMID:19300517

  14. Multisite reproducibility of the broth microdilution method for susceptibility testing of Nocardia species.

    Science.gov (United States)

    Conville, Patricia S; Brown-Elliott, Barbara A; Wallace, Richard J; Witebsky, Frank G; Koziol, Deloris; Hall, Geraldine S; Killian, Scott B; Knapp, Cindy C; Warshauer, David; Van, Tam; Wengenack, Nancy L; Deml, Sharon; Woods, Gail L

    2012-04-01

    Antimicrobial susceptibility testing (AST) of clinical isolates of Nocardia is recommended to detect resistance to commonly used antimicrobial agents; such testing is complicated by difficulties in inoculum preparation and test interpretation. In this study, six laboratories performed repetitive broth microdilution testing on single strains of Nocardia brasiliensis, Nocardia cyriacigeorgica, Nocardia farcinica, Nocardia nova, and Nocardia wallacei. For each isolate, a total of 30 microdilution panels from three different lots were tested at most sites. The goal of the study was to determine the inter- and intralaboratory reproducibility of susceptibility testing of this group of isolates. Acceptable agreement (>90% agreement at ±1 dilution of the MIC mode) was found for amikacin, ciprofloxacin, clarithromycin, and moxifloxacin. After eliminating MIC values from single laboratories whose results showed the greatest deviation from those of the remaining laboratories, acceptable agreement was also found for amoxicillin-clavulanic acid, linezolid, minocycline, and tobramycin. Results showed unsatisfactory reproducibility of broth microdilution testing of ceftriaxone with N. cyriacigeorgica and N. wallacei, tigecycline with N. brasiliensis and N. cyriacigeorgica, and sulfonamides with N. farcinica and N. wallacei. N. nova ATCC BAA-2227 is proposed as a quality control organism for AST of Nocardia sp., and the use of a disk diffusion test for sulfisoxazole is proposed as a check of the adequacy of the inoculum and to confirm sulfonamide MIC results.

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

    Science.gov (United States)

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

    2016-12-01

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

  16. Screening of antifungal agents using ethanol precipitation and bioautography of medicinal and food plants.

    Science.gov (United States)

    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.

  17. Molecular Identification and Conventional Susceptibility Testing of Iranian Clinical Mycobacterium fortuitum Isolates

    Directory of Open Access Journals (Sweden)

    Parvin Heidarieh

    2010-01-01

    Full Text Available Rapidly growing mycobacteria (RGM are capable of producing diseases in humans. Since mycobacteria vary in their susceptibility, precise identification is critical for adoption of correct drug therapy. The main aim of this study was molecular identification and evaluation of antimicrobial susceptibility pattern of Iranian clinically isolated Myocbacterium fortuitum.Materials and MethodsA total of 72 presumptively identified isolates of clinical atypical mycobacteria collected by Isfahan Research Center for Infectious Diseases & Tropical Medicine during 2006-2008 were included in the current study. A combination of conventional and molecular tests was applied to identify the isolates. Molecular methods including genus and group specific PCR and PCR-Restriction Algorithm (PRA based on hsp65 gene were applied to achieve exact identification of mycobacterial strains. Antimicrobial susceptibility testing on M. fortuitum isolates was performed by in-house prepared broth microdilution test..ResultsOut of 72 collected atypical mycobacteria isolates, we identified 25 strains of M. fortuitum. All strains had the specific molecular markers of mycobacterial identity and similar species specific PRA pattern of the international type strain of M. fortuitum. Drug susceptibility testing showed that the M. fortuitum isolates are sensitive to amikacin, sulfamethoxazole and ciprofloxacin (100%, imipenem (92%, clarithromycin (76%, cefoxitin (56% and doxycycline (16%.ConclusionMolecular identification of atypical mycobacteria based on PRA is a reliable and rapid approach which can identify mycobacterial strains to the species level. Our study showed that M. fortuitum plays a significant role in pulmonary and extrapulmonary infection in patients and should be given proper considerations when clinical samples are processed.

  18. Use of linezolid susceptibility test results as a surrogate for the susceptibility of Gram-positive pathogens to tedizolid, a novel oxazolidinone.

    Science.gov (United States)

    Zurenko, Gary; Bien, Paul; Bensaci, Mekki; Patel, Hina N; Thorne, Grace

    2014-09-20

    Tedizolid is a novel oxazolidinone antibacterial with potent activity against a wide range of Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. Although tedizolid is approved by the US Food and Drug Administration (FDA) for treatment of patients with acute bacterial skin and skin structure infection, commercial susceptibility testing products for tedizolid are not currently available. This study evaluated the usefulness of applying linezolid susceptibility test results as a surrogate for predicting susceptibility to tedizolid in clinically significant Gram-positive pathogens. Gram-positive isolates (N = 10,702) were obtained from annual surveillance programs conducted between 2009 and 2012, from 3 tedizolid clinical trials, and from a preclinical study of the antibacterial activity of tedizolid. Susceptibility testing of linezolid and tedizolid was performed using the reference broth microdilution method in accordance with Clinical and Laboratory Standards Institute methods. The minimum inhibitory concentration (MIC) distribution for tedizolid and linezolid against this set of isolates was consistent with that of previous reports. Scatter plot analysis of relevant subsets of organisms was performed and showed high categorical agreement between linezolid and tedizolid MIC results (>99% for staphylococci and streptococci; >98% for enterococci). Very major error rates (ie, tedizolid false-susceptible errors) were very low and within acceptable limits for a surrogate agent: S. aureus and other staphylococcal species, 0%; Enterococcus spp, 0.2%; and Streptococcus spp, 0%. High categorical agreement between MIC values for tedizolid and linezolid and low very major error rates were shown for all organism groups tested, supporting the use of linezolid as a reliable surrogate for tedizolid susceptibility testing.

  19. New method for rapid Susceptibility Testing on blood culture with HB&L system: preliminary data

    Directory of Open Access Journals (Sweden)

    Vincenzo Rondinelli

    2010-12-01

    Full Text Available Blood culture, although represents the gold standard in detecting the ethiological agent of sepsis, is rather rarely required in relation to the real diagnostic importance. The result of this test depends in fact on many factors (sample volume, time of collection, accuracy, antibiotic therapy, contamination, number of drawings, drawing site, interpretation difficulties, etc. that are often considered by many clinicians so limited as to doubt about their actual value. The disadvantages are therefore represented by the lack of standardization but also by the low sensitivity and above all by the technical times too long for the clinical needs. Blood culture begins with the drawing of samples from the “septic” patient followed incubation of the bottles in automatic thermostated systems. In case of positive result (36 hours, the culture is Gram stained and streaked on solid media in order to obtain isolated colonies for the identification and the susceptibility testing (48 hours from positive result. The long time required for pathogen identification and susceptibility testing involves empirical broad spectrum antibiotic therapy that can promote the increase of bacterial resistance but also patient management costs. A clinically useful report should be available on short notice in order to guide the clinician to choose the most appropriate antibiotic. The microbiologist has therefore the hard work of reviewing the organization and the management of the procedures.We have therefore started to consider the possibility of treating the blood as an biological liquid in order to quickly determine the susceptibility of bacteria to antibiotics.

  20. A two-hour antibiotic susceptibility test by ATP-bioluminescence.

    Science.gov (United States)

    March Rosselló, Gabriel Alberto; García-Loygorri Jordán de Urries, María Cristina; Gutiérrez Rodríguez, María Purificación; Simarro Grande, María; Orduña Domingo, Antonio; Bratos Pérez, Miguel Ángel

    2016-01-01

    The antibiotic susceptibility test (AST) in Clinical Microbiology laboratories is still time-consuming, and most procedures take 24h to yield results. In this study, a rapid antimicrobial susceptibility test using ATP-bioluminescence has been developed. The design of method was performed using five ATCC collection strains of known susceptibility. This procedure was then validated against standard commercial methods on 10 strains of enterococci, 10 staphylococci, 10 non-fermenting gram negative bacilli, and 13 Enterobacteriaceae from patients. The agreement obtained in the sensitivity between the ATP-bioluminescence method and commercial methods (E-test, MicroScan and VITEK2) was 100%. In summary, the preliminary results obtained in this work show that the ATP-bioluminescence method could provide a fast and reliable AST in two hours. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  1. Growth inhibition of Mycobacterium tuberculosis by polyoxyethylene stearate present in the BACTEC pyrazinamide susceptibility test.

    Science.gov (United States)

    Miller, M A; Thibert, L; Desjardins, F; Siddiqi, S H; Dascal, A

    1996-01-01

    We have previously found that approximately 3.5% of 428 clinical isolates of Mycobacterium tuberculosis yield uninterpretable results in the BACTEC pyrazinamide (PZA) susceptibility test system, because of inadequate growth. We tested the hypothesis that polyoxyethylene stearate (POES), the ingredient of the reconstituting fluid for the test, was the cause of this growth inhibition. A total of 15 isolates known for their previously uninterpretable results and 100 randomly chosen clinical isolates were tested in parallel both with and without POES. Repeat testing of the isolates with previously uninterpretable results yielded results in the presence of POES in only seven (47%). In the absence of POES, all gave interpretable results but one such result showed false resistance. For the other 100 clinical isolates, interpretable results were obtained with and without POES, but growth was enhanced in the absence of POES, especially in the PZA-susceptible strains. This was evidenced by a decreased time to attain a growth index of 200 in the control vial (4.9 days without POES versus 5.8 days with POES; P interpretation of the test (7.4% without POES versus 2.2% with POES; P interpretable results indicating PZA resistance are obtained only in the absence of POES, the result should be confirmed by a pyrazinamidase assay or by the conventional proportion method. Routine omission of POES from the BACTEC test for all clinical strains is discouraged because of the unacceptably high false-resistance rates.

  2. Susceptibility testing and reporting of new antibiotics with a focus on tedizolid: an international working group report.

    Science.gov (United States)

    Wilcox, Mark H; Dmitrieva, Natalia; Gales, Ana Cristina; Petukhova, Irina; Al-Obeid, Suleiman; Rossi, Flavia; M Blondeau, Joseph

    2017-12-01

    Inappropriate use and overuse of antibiotics are among the most important factors in resistance development, and effective antibiotic stewardship measures are needed to optimize outcomes. Selection of appropriate antimicrobials relies on accurate and timely antimicrobial susceptibility testing. However, the availability of clinical breakpoints and in vitro susceptibility testing often lags behind regulatory approval by several years for new antimicrobials. A Working Group of clinical/medical microbiologists from Brazil, Canada, Mexico, Saudi Arabia, Russia and the UK recently examined issues surrounding antimicrobial susceptibility testing for novel antibiotics. While commercially available tests are being developed, potential surrogate antibiotics may be used as marker of susceptibility. Using tedizolid as an example of a new antibiotic, this special report makes recommendations to optimize routine susceptibility reporting.

  3. Study on hydrogen assisted cracking susceptibility of HSLA steel by implant test

    Directory of Open Access Journals (Sweden)

    Gopa Chakraborty

    2016-12-01

    Full Text Available DMR-249A is an indigenously developed high strength low alloy steel for Indian ship building industry for making ship-hull and is extensively used in the construction of war ships and submarines. Welding electrodes conforming to SFA 5.5 AWS E8018 C1 has been indigenously developed for welding of this steel using shielded metal arc welding process. In the present study, susceptibility to hydrogen assisted cracking of DMR-249A steel welds made using this electrode has been assessed using implant test. Implant tests were conducted using this electrode at two different levels of diffusible hydrogen, measured using gas chromatography technique. It is observed that both the steel and the welding consumable are not susceptible to hydrogen assisted cracking even with a high diffusible hydrogen level of 9 mL/100g of weld metal. In implant tests, specimen did not fracture even after loading to stress levels higher than the yield strength of the base metal. The good resistance of this steel and the welding consumable, even with high levels of diffusible hydrogen, is attributed to absence of a susceptible microstructure in both the weld metal and heat affected zone. Hence, this study shows that, in the absence of a susceptible microstructure, hydrogen assisted cracking is unlikely to occur even if hydrogen level is high. It also confirms that in welding of DMR-249A with indigenously developed E8018 C1 electrode, hydrogen assisted cracking is not a concern and no preheating is required to avoid it during welding.

  4. Antifungal activity of some tetranortriterpenoids.

    Science.gov (United States)

    Govindachari, T R; Suresh, G; Gopalakrishnan, G; Masilamani, S; Banumathi, B

    2000-06-01

    Natural tetranortriterpenoids such as cedrelone from Toona ciliata, azadiradione from Azadirachta indica, limonin, limonol and nomilinic acid from Citrus medica, along with some cedrelone derivatives were tested for their antifungal activity against Puccinia arachidis, a groundnut rust pathogen. Results show that cedrelone was the most effective in reducing rust pustule emergence. Replacement of functional groups or modification of the A or the B ring in cedrelone reduced the effectiveness indicating the importance of specific structural features for activity.

  5. In-vitro Activity of 10 Antifungal Agents against 320 Dermatophyte Strains Using Microdilution Method in Tehran

    Science.gov (United States)

    Adimi, Parvaneh; Hashemi, Seyed Jamal; Mahmoudi, Mahmood; Mirhendi, Hossein; Shidfar, Mohammad Reza; Emmami, Masood; Rezaei-Matehkolaei, Ali; Gramishoar, Mohsen; Kordbacheh, Parivash

    2013-01-01

    Dermatophyte fungi are the etiologic agents of skin infections commonly referred to as ringworm. These infections are not dangerous but as a chronic cutaneous infections they may be difficult to treat and can also cause physical discomfort for patients. They are considered important as a public health problem as well. No information is available regarding the efficacy of antifungal agents against dermatophytes in Tehran. Therefore, in this study we evaluated the efficacy of 10 systemic and topical antifungal medications using CLSI broth microdilution method (M38-A). The antifungal agents used included griseofulvin, terbinafine, itraconazole, ketoconazole, fluconazole, voriconazole, clotrimazole, ciclopirox olamine, amorolfine and naftifine.Fifteen different species of dermatophytes which were mostly clinical isolates were used as follows; T. mentagrophytes, T. rubrum, E. floccosum, M. canis, T. verrucosum, T. tonsurans, M. gypseum, T. violaceum, M. ferruginum, M. fulvum, T. schoenleinii, M. racemosum, T. erinacei, T. eriotrephon and Arthroderma benhamiae. The mean number of fungi particles (conidia) inoculated was 1.25 ×10⁴ CFU/mL. Results were read after 7 days of incubation at 28 °C. According to the obtained results,itraconazole and terbinafine showed the lowest and fluconazole had the greatest MIC values for the most fungi tested. Based on the results, it is necessary to do more research and design a reliable standard method for determination of antifungal susceptibility to choose proper antibiotics with fewer side effects and decrease antifungal resistance and risk of treatment failure. PMID:24250660

  6. EUCAST recommendations for antimicrobial susceptibility testing applied to the three main Campylobacter species isolated in humans.

    Science.gov (United States)

    Sifré, Elodie; Salha, Ben Amor; Ducournau, Astrid; Floch, Pauline; Chardon, Hubert; Mégraud, Francis; Lehours, Philippe

    2015-12-01

    Antimicrobial susceptibility testing of Campylobacter isolates is of great importance for treatment options especially in systemic diseases. The European Committee for Antimicrobial Susceptibility Testing (EUCAST) recently proposed epidemiological cut-offs (ECOFFs) for a limited number of antimicrobial compounds and for Campylobacter jejuni and Campylobacter coli only. In the present study, the EUCAST method was used after minor modifications to define antimicrobial susceptibility patterns for, 1997 C. jejuni, 419 C. coli and 100 Campylobacter fetus strains received at the French National Reference Center for Campylobacters and Helicobacters. Our results show that the ECOFFs defined by EUCAST for tetracycline and ciprofloxacin can be used for C. jejuni and C. coli. The same ECOFF can be used for erythromycin for the three species. The C. jejuni and C. coli ECOFFs for ciprofloxacin however cannot be applied to C. fetus. We also provide data to categorise two 2 β-lactams of interest for systemic diseases, ampicillin and amoxicillin+clavulanate, for the three species. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Combination antimicrobial susceptibility testing of Burkholderia cepacia complex: significance of species.

    Science.gov (United States)

    Abbott, Felicity K; Milne, Kathleen E N; Stead, David A; Gould, Ian M

    2016-11-01

    The Burkholderia cepacia complex (Bcc) is notorious for the life-threatening pulmonary infections it causes in patients with cystic fibrosis. The multidrug-resistant nature of Bcc and differing infective Bcc species make the design of appropriate treatment regimens challenging. Previous synergy studies have failed to take account of the species of Bcc isolates. Etest methodology was used to facilitate minimum inhibitory concentration (MIC) and antimicrobial combination testing on 258 isolates of Bcc, identified to species level by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). The most active antimicrobials were trimethoprim/sulphamethoxazole, doxycycline and minocycline (52.5%, 46.4% and 45.9% of isolates susceptible, respectively). Synergy was observed in 9.2% of the 1799 combinations tested; the most common synergistic combinations were tobramycin + ceftazidime, meropenem + tobramycin and levofloxacin + piperacillin/tazobactam (35.4%, 32.3% and 22.2% synergy, respectively). Antimicrobial susceptibility analysis revealed differences between Burkholderia cenocepacia and Burkholderia multivorans. Disparity in clinical outcome during infection with these two micro-organisms necessitates further investigation into the clinical outcomes of treatment regimens in light of species identification and in vitro antimicrobial susceptibility studies. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  8. Antimicrobial Disk Susceptibility Testing of Leptospira spp. Using Leptospira Vanaporn Wuthiekanun (LVW) Agar.

    Science.gov (United States)

    Wuthiekanun, Vanaporn; Amornchai, Premjit; Langla, Sayan; White, Nicholas J; Day, Nicholas P J; Limmathurotsakul, Direk; Peacock, Sharon J

    2015-08-01

    Leptospira Vanaporn Wuthiekanun (LVW) agar was used to develop a disk diffusion assay for Leptospira spp. Ten pathogenic Leptospira isolates were tested, all of which were susceptible to 17 antimicrobial agents (amoxicillin/clavulanic acid, amoxicillin, azithromycin, cefoxitin, ceftazidime, ceftriaxone, chloramphenicol, ciprofloxacin, clindamycin, doripenem, doxycycline, gentamicin, linezolid, nitrofurantoin, penicillin, piperacillin/tazobactam, and tetracycline). All 10 isolates had no zone of growth inhibition for four antimicrobials (fosfomycin, nalidixic acid, rifampicin, and trimethoprim/sulfamethoxazole). Of the ten Leptospira, seven had a growth inhibition zone of ≤ 21 mm for aztreonam, the zone diameter susceptibility break point for Enterobacteriaceae. This assay could find utility as a simple screening method during the epidemiological surveillance of antimicrobial resistance in Leptospira spp. © The American Society of Tropical Medicine and Hygiene.

  9. Ten years of antimicrobial susceptibility testing of Salmonella from Danish pig farms

    DEFF Research Database (Denmark)

    Emborg, Hanne-Dorthe; Baggesen, Dorte Lau; Aarestrup, Frank Møller

    2008-01-01

    Objectives: This study analysed the trends in antimicrobial resistance in Salmonella serovars and phage types from pigs in Denmark from 1997 to 2006. Methods: Salmonella isolates collected through the Salmonella surveillance programme in pigs were serotyped and phage-typed, and susceptibilities...... to the following antimicrobials were determined: ampicillin, chloramphenicol, gentamicin, nalidixic acid, colistin, streptomycin, sulphonamide, tetracycline and trimethoprim. Results: No significant development of resistance occurred within the most important serovars, except Salmonella Typhimurium. A major...... decrease in Salmonella Typhimurium DT12 occurred from 46.5% in 1998 to 16.8% in 2006 while DT120, DT170 and DT104 increased. Throughout the study period, 80.9% of the DT12 isolates remained susceptible to the antimicrobials tested despite an increase in antimicrobial consumption in pigs during the period...

  10. Methicillin Resistant Staphylococcus aureus: Inconsistencies in Vancomycin Susceptibility Testing Methods, Limitations and Advantages of each Method.

    Science.gov (United States)

    Himani; Agrawal, Charu; Madan, Molly; Pandey, Anita; Thakuria, Bhaskar

    2015-10-01

    Vancomycin may be ineffective against an increasing proportion of methicillin resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentrations (MICs) well within the susceptible range. On the other hand it is common knowledge that determination of vancomycin MICs is method dependent. Therefore, given the apparent variability in vancomycin MIC results obtained with the different methods, the use of the vancomycin MIC to predict the outcome of serious S. aureus infections needs to take into account the method used and the results of studies using that particular method. Comparative study was carried out to evaluate the MICs obtained by BMD method, E-test, and Vitek 2 method and to detect inconsistencies in these vancomycin for 66 MRSA isolates obtained from various samples of patients attending the OPDs & IPDs within a period of one year. A comparative study was carried out to evaluate the MICs obtained by BMD method, E-test, and Vitek 2 method to detect vancomycin susceptibility in 66 clinical isolates of MRSA obtained from various samples of patients attending the OPDs & IPDs within a period of one year. The study was conducted in Department of Microbiology, Subharti Medical College, Meerut from January to December 2012. On determination of MICs for vancomycin for the MRSA isolates, all were identified as VSSA by BMD, E-Test & Vitek 2 methods. However, the vancomycin MIC values obtained by E-test correlated better with BMD method (correlation factor= 0.6727) than Vitek 2 (correlation factor=0.5316), indicating E-Test to be a better method for determination of vancomycin MICs as compared to Vitek 2. MRSA isolates with higher vancomycin MICs, even within the susceptibility range, are being observed more frequently which result in treatment failures with vancomycin. Because of the discrepancy that exists in vancomycin MIC results from different methods, the prediction of outcome of serious S.aureus infections should take into account the method used

  11. Oropharyngeal candidiasis and resistance to antifungal drugs in patients receiving radiation for head and neck cancer

    Directory of Open Access Journals (Sweden)

    Maryam Rad DMD, MSc

    2012-04-01

    Full Text Available BACKGROUND: Oropharyngeal candidiasis is a common infection in patient receiving radiotherapy for head and neckcancer. Accurate and rapid identification of candida species is very important in clinical laboratory, because theincidence of candidiasis continues to rise after radiotherapy. The genus Candida has about 154 species that showdifferent level of resistance to antifungal drugs and have high degree of phenotypic similarity. The aim of this study wasto investigate oral yeast colonization and infection and resistance to antifungal drugs in these patients.METHODS: Thirty patients receiving a 6-week course of radiation therapy for treatment of head and neck cancer at theOncology Unit in Shafa Hospital, in 2008, were enrolled in the study. Specimens from patients were cultured weeklyfor Candida. All isolates were plated on CHROM agar and RPMI-based medium. They were subcultured and submittedfor antifungal susceptibility testing (nystatin, fluconazole, clotrimazole and ketoconazole and molecular typing.RESULTS: Infection (clinical and microbiological evidence occurred in 50% of the patients and Candida colonization(only microbiological evidence occurred in 70% of subjects in the first week. Candida albicans alone was isolated in94.9% of patient visits with positive cultures. Candida tropicalis was isolated from 5.1% of patient visits with positivecultures. All isolates were susceptible to nystatin, but did not respond to the other antifungal drugsCONCLUSIONS: The irradiation-induced changes of the intraoral environment such as xerostomia lead to increasedintraoral colonization by Candida species. All yeast isolates were susceptible to nystatin. Thus prophylactic therapywith nystatin should be considered for these patients.

  12. The Hsp90 co-chaperones Sti1, Aha1, and P23 regulate adaptive responses to antifungal azoles

    Directory of Open Access Journals (Sweden)

    Xiaokui Gu

    2016-10-01

    Full Text Available 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.

  13. Epidemiology, risk factor, species distribution, antifungal resistance and outcome of Candidemia at a single French hospital: a 7-year study.

    Science.gov (United States)

    Tadec, Laurent; Talarmin, Jean-Philippe; Gastinne, Thomas; Bretonnière, Cédric; Miegeville, Michel; Le Pape, Patrice; Morio, Florent

    2016-05-01

    Candidemia remains a major cause of disease worldwide and is associated with a high mortality rate. We conducted a retrospective study of candidemia at Nantes Hospital, France, between 2004 and 2010. A total of 191 episodes (n = 188 patients) were reviewed. Incidence, demographics, risk factors, antifungal management, species identification, in vitro susceptibility and 12 weeks survival were analysed. Global incidence of candidemia was 0.37‰ admissions. Higher incidences were observed in haematology (6.65‰) and intensive care units (2‰). Central venous catheter and antibiotic exposure were the most frequent risk factors (77% and 76% respectively). Candida albicans was the predominant species (51.8%) followed by C. parapsilosis (14.5%), C. glabrata (9.8%), C. tropicalis (9.8%) and C. krusei (4.1%). However, species distribution differed significantly between medical units with frequency of C. tropicalis being higher in haematology compared to other medical units. Fluconazole and caspofungin were the main antifungals given as first-line therapy. Although not significant, 12 weeks mortality rate was 30.9%, being higher for C. tropicalis (44.4%) than for C. parapsilosis (16%). Acquired azole or echinocandin resistance was noted in some isolates, underlining the need for systematic antifungal susceptibility testing in patients with candidemia. These epidemiological findings will be of interest for antifungal stewardship at our hospital. © 2016 Blackwell Verlag GmbH.

  14. Neuraminidase Inhibitor Susceptibility Testing in Human Influenza Viruses: A Laboratory Surveillance Perspective

    Science.gov (United States)

    Okomo-Adhiambo, Margaret; Sleeman, Katrina; Ballenger, Kristina; Nguyen, Ha T.; Mishin, Vasiliy P.; Sheu, Tiffany G.; Smagala, James; Li, Yan; Klimov, Alexander I.; Gubareva, Larisa V.

    2010-01-01

    Neuraminidase inhibitors (NAIs) are vital in managing seasonal and pandemic influenza infections. NAI susceptibilities of virus isolates (n = 5540) collected during the 2008–2009 influenza season were assessed in the chemiluminescent neuraminidase inhibition (NI) assay. Box-and-whisker plot analyses of log-transformed IC50s were performed for each virus type/subtype and NAI to identify outliers which were characterized based on a statistical cutoff of IC50 >3 interquartile ranges (IQR) from the 75th percentile. Among 1533 seasonal H1N1 viruses tested, 1431 (93.3%) were outliers for oseltamivir; they all harbored the H275Y mutation in the neuraminidase (NA) and were reported as oseltamivir-resistant. Only 15 (0.7%) of pandemic 2009 H1N1 viruses tested (n = 2259) were resistant to oseltamivir. All influenza A(H3N2) (n = 834) and B (n = 914) viruses were sensitive to oseltamivir, except for one A(H3N2) and one B virus, with D151V and D197E (D198E in N2 numbering) mutations in the NA, respectively. All viruses tested were sensitive to zanamivir, except for six seasonal A(H1N1) and several A(H3N2) outliers (n = 22) which exhibited cell culture induced mutations at residue D151 of the NA. A subset of viruses (n = 1058) tested for peramivir were sensitive to the drug, with exception of H275Y variants that exhibited reduced susceptibility to this NAI. This study summarizes baseline susceptibility patterns of seasonal and pandemic influenza viruses, and seeks to contribute towards criteria for defining NAI resistance. PMID:21994620

  15. Termite-Susceptible Species of Wood for Inclusion as a Reference in Indonesian Standardized Laboratory Testing

    Directory of Open Access Journals (Sweden)

    Arinana

    2012-03-01

    Full Text Available Standardized laboratory testing of wood and wood-based products against subterranean termites in Indonesia (SNI 01.7207-2006 (SNI has no requirement for the inclusion of a comparative reference species of wood (reference control. This is considered a weakness of the Indonesian standard. Consequently, a study was undertaken to identify a suitable Indonesian species of community wood that could be used as a reference control. Four candidate species of community woods: Acacia mangium, Hevea brasiliensis, Paraserianthes falcataria and Pinus merkusii were selected for testing their susceptibility to feeding by Coptotermes formosanus. Two testing methods (SNI and the Japanese standard method JIS K 1571-2004 were used to compare the susceptibility of each species of wood. Included in the study was Cryptomeria japonica, the reference control specified in the Japanese standard. The results of the study indicated that P. merkusii is a suitable reference species of wood for inclusion in laboratory tests against subterranean termites, conducted in accordance with the Indonesian standard (SNI 01.7207-2006.

  16. Dermatophyte susceptibility varies towards antimicrobial textiles.

    Science.gov (United States)

    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. © 2011 Blackwell Verlag GmbH.

  17. Rapid susceptibility testing of Mycobacterium tuberculosis by bioluminescence assay of mycobacterial ATP

    International Nuclear Information System (INIS)

    Nilsson, L.E.; Hoffner, S.E.; Ansehn, S.

    1988-01-01

    Mycobacterial growth was monitored by bioluminescence assay of mycobacterial ATP. Cultures of Mycobacterium tuberculosis H37Rv and of 25 clinical isolates of the same species were exposed to serial dilutions of ethambutol, isoniazid, rifampin, and streptomycin. A suppression of ATP, indicating growth inhibition, occurred for susceptible but not resistant strains within 5 to 7 days of incubation. Breakpoint concentrations between susceptibility and resistance were determined by comparing these results with those obtained by reference techniques. Full agreement was found in 99% of the assays with the resistance ratio method on Lowenstein-Jensen medium, and 98% of the assays were in full agreement with the radiometric system (BACTEC). A main advantage of the bioluminescence method is its rapidity, with results available as fast as with the radiometric system but at a lower cost and without the need for radioactive culture medium. The method provides kinetic data concerning drug effects within available in vivo drug concentrations and has great potential for both rapid routine susceptibility testing and research applications in studies of drug effects on mycobacteria

  18. Are Adolescents with ADHD Interested in Genetic Testing for Nicotine Addiction Susceptibility?

    Directory of Open Access Journals (Sweden)

    Linda J. Herbert

    2010-04-01

    Full Text Available It has been well-established that some adolescents diagnosed with attention-deficit/hyperactivity disorder (ADHD are at increased risk for cigarette smoking. Current research on the genetic basis of this association could ultimately translate into genetic tests capable of identifying smoking-prone adolescents with ADHD. In this study we examined 81 ADHD affected adolescents’ (age 13–21 interest in genetic testing for nicotine addiction susceptibility. Fifty-seven percent of adolescents indicated a fair amount of interest or more in testing. Most adolescents indicated that the personal information revealed from testing would be either useful (29% or interesting (37%. Implications for genetically-informed smoking prevention and cessation interventions in high risk adolescents with ADHD are discussed.

  19. Individual susceptibility to UV and ionizing radiations: DNA repair evaluated by the comets test

    International Nuclear Information System (INIS)

    Alapetite, C.

    1999-01-01

    Some patients having a cancer treated by radiotherapy can suffer from an hypersensitivity with respect to UV and ionizing radiations which corresponds to an inter-individual variability of the response to the geno-toxic stress induced by radiations. A predictive approach of this risk has been developed which shows the interest of an analysis of the individual capacities of repair of DNA radio-lesions. This approach uses the alkaline comets test. The application of this test to the patients' lymphocytes shows a high percentage of severe reactions of normal tissues after the radiotherapy course with a high residual level of broken DNA strands which gives evidence for a repair defect. The retrospective application of this test to breast cancers with radiotherapy complications without any genetical predisposition has permitted to validate this test in order to use it as a predictive diagnosis of the individual susceptibility of patients with respect to radiotherapy. (J.S.)

  20. IIn vitro antifungal evaluation of various plant extracts against early ...

    African Journals Online (AJOL)

    Antifungal activities of 27 plant extracts were tested against Alternaria solani (E. & M.) Jones and Grout using radial growth technique. While all tested plant extracts produced some antifungal activities, the results revealed that Circium arvense, Humulus lupulus, Lauris nobilis and Salvia officinalis showed significant ...

  1. Evaluation of a semi-automated reporter phage assay for susceptibility testing of Mycobacterium tuberculosis isolates in South Africa.

    Science.gov (United States)

    Banaiee, Niaz; January, Vanessa; Barthus, Charmaine; Lambrick, Maureen; Roditi, Denise; Behr, Marcel A; Jacobs, William R; Steyn, Lafras M

    2008-01-01

    In a prospective study conducted by laboratory technologists in a diagnostic laboratory in Cape Town, South Africa, a semi-automated phage-based antibiotic susceptibility assay was implemented and the performance of the luciferase reporter mycobacteriophage (LRP) system for susceptibility testing of clinical Mycobacterium tuberculosis complex (MTC) isolates against rifampin and isoniazid was evaluated. Two hundred consecutive clinical MGIT cultures of MTC species were included in this study. Antibiotic susceptibility assays were set up manually for the LRP and BACTEC radiometric systems (BACTEC) and read in a plate luminometer and the BACTEC 460 instrument, respectively. Discrepant susceptibility results were resolved by the conventional agar proportion method. Of the 200 secondary cultures prepared for this study, 9 (4.5%) were lost to contamination (LRP 4, BACTEC 1, both 4). All of the remaining 191 cultures underwent susceptibility testing by both methods and the overall agreement between the LRP and BACTEC was 98.4% (rifampin 100%; isoniazid 96.9%). Of the 6 discrepant cultures tested by the agar proportion method, 2 gave results in agreement with the LRP. The sensitivity of the LRP for detection of drug-resistant isolates was 100% for both rifampin (n=9) and isoniazid (n=12). The median turnaround time for susceptibility testing was 2 days with the LRP and 9 days with BACTEC. In conclusion, the semi-automated LRP-based assay offers a rapid and practical approach for accurate susceptibility testing of M. tuberculosis cultures in diagnostic laboratories with limited financial resources, but with competent technologists.

  2. In vitro susceptibility testing of fluoroquinolone activity against Salmonella: recent changes to CLSI standards

    DEFF Research Database (Denmark)

    Humphries, R. M.; Fang, F. C.; Aarestrup, Frank Møller

    2012-01-01

    this issue by revising the ciprofloxacin break points for Salmonella species. It is critical for clinicians and laboratory workers to be aware of the multiple technical issues surrounding these revised break points. In this article, we review FQ resistance mechanisms in Salmonella, their clinical...... significance, and data supporting the revised ciprofloxacin break points. We encourage clinical laboratories to adopt the revised CLSI ciprofloxacin break points for all Salmonella isolates in which susceptibility testing is indicated and discuss the technical issues for laboratories using commercial...

  3. Evaluation of automated systems for aminoglycosides and fluoroquinolones susceptibility testing for Carbapenem-resistant Enterobacteriaceae

    Directory of Open Access Journals (Sweden)

    Zhichang Zhao

    2017-08-01

    Full Text Available Abstract Background Automated systems (MicroScan WalkAway 96 Plus, Phoenix 100, and Vitek 2 Compact are widely used in clinical laboratories nowadays. The aim of this study is to evaluate the performance of these three systems for susceptibility testing of aminoglycosides and fluoroquinolones against Carbapenem-resistant Enterobacteriaceae (CRE. Methods A total of 75 CRE isolates were used in this study. Quinolone resistance determinants (QRDs (qnrA, qnrB, qnrC, qnrD, qnrS, aac(6′-Ib-cr, oqxAB and qepA and aminoglycoside resistance determinants (ARDs (aac(6′-Ib, armA, npmA, rmtA, rmtB, rmtC, rmtD and rmtE of these CRE were screened by PCR. The MICs of aminoglycosides (gentamicin and amikacin and fluoroquinolones (ciprofloxacin and levofloxacin to CRE obtained with the automated systems were compared with the reference method (agar dilution method. Results Totally, 97.3% (73/75 of CRE harbored QRDs. The qnr gene was the most common QRD determinant identified in 68 (96.7%, followed by aac (6′-Ib-cr in 56 (74.7%, oqxAB in 23 (30.7%, and qepA in 2 (2.7%, respectively. 22.7% (17/75 of CRE harbored ARD determinants. rmtA, rmtB and npmA were identified among these isolates in 6 (8.0%, 6 (8.0% and 5 (6.7%, respectively. A total of 900 results were obtained in this study. Overall, the total error rate was 9.89%. Twenty-eight very major errors (3.11%, 22 major errors (2.44% and 39 minor errors (4.33% were identified against agar dilution method. The very major errors were almost evenly distributed between results for fluoroquinolones (2.89% and aminoglycosides (3.33%, while the major errors and minor errors were more commonly found in the results of fluoroquinolones (3.11% and 6.44%, respectively than aminoglycosides (1.78% and 2.22%, respectively. Conclusions Our study shows that testing difficulties in susceptibility testing do exist in automated systems. We suggest clinical laboratories using automated systems should consider using a second

  4. In vitro antifungal activities of 26 plant extracts on mycelial growth of ...

    African Journals Online (AJOL)

    Antifungal activities of 26 plant extracts were tested against Phytophthora infestans using radial growth technique. While all tested plant extracts produced some antifungal activities Xanthium strumarium, Lauris nobilis, Salvia officinalis and Styrax officinalis were the most active plants that showed potent antifungal activity.

  5. Staphylococcus aureus biofilm formation and antibiotic susceptibility tests on polystyrene and metal surfaces.

    Science.gov (United States)

    Coraça-Huber, D C; Fille, M; Hausdorfer, J; Pfaller, K; Nogler, M

    2012-06-01

    We compared the MBEC™-HTP assay plates made of polystyrene with metal discs composed of TMZF(®) and CrCo as substrates for biofilm formation. Staphylococcus aureus was grown on polystyrene and on metal discs made of titanium and chrome-cobalt. Antibiotic susceptibility was assessed by examining the recovery of cells after antibiotic exposure and by measuring the biofilm inhibitory concentration (BIC). The minimal inhibitory concentration (MIC) was assessed with planktonic cells. Bacterial growth was examined by scanning electron microscopy. The antibiotic concentration for biofilm inhibition (BIC) was higher than the MIC for all antibiotics. Microscopic images showed the biofilm structure characterized by groups of cells covered by a film. All models allowed biofilm formation and testing with several antibiotics in vitro. Gentamicin and rifampicin are the most effective inhibitors of Staph. aureus biofilm-related infections. We recommend MBEC™-HTP assay for rapid testing of multiple substances and TMZF(®) and CrCo discs for low-throughput testing of antibiotic susceptibility and for microscopic analysis. In vitro assays can improve the understanding of biofilms and help developing methods to eliminate biofilms from implant surfaces. One advantage of the TMZF(®) and CrCo discs as biofilm in vitro assay is that these metals are commonly used for orthopaedic implants. These models are usable for future periprosthetic joint infection studies. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  6. A cost-effective smartphone-based antimicrobial susceptibility test reader for drug resistance testing (Conference Presentation)

    Science.gov (United States)

    Feng, Steve W.; Tseng, Derek; Di Carlo, Dino; Garner, Omai B.; Ozcan, Aydogan

    2017-03-01

    Antimicrobial susceptibility testing (AST) is commonly used for determining microbial drug resistance, but routine testing, which can significantly reduce the spread of multi-drug resistant organisms, is not regularly performed in resource-limited and field-settings due to technological challenges and lack of trained diagnosticians. We developed a portable cost-effective smartphone-based colorimetric 96-well microtiter plate (MTP) reader capable of automated AST without the need for a trained diagnostician. This system is composed of a smartphone used in conjunction with a 3D-printed opto-mechanical attachment, which holds a set of inexpensive light-emitting-diodes and fiber-optic cables coupled to the 96-well MTP for enabling the capture of the transmitted light through each well by the smartphone camera. Images of the MTP plate are captured at multiple exposures and uploaded to a local or remote server (e.g., a laptop) for automated processing/analysis of the results using a custom-designed smartphone application. Each set of images are combined to generate a high dynamic-range image and analyzed for well turbidity (indicative of bacterial growth), followed by interpretative analysis per plate to determine minimum inhibitory concentration (MIC) and drug susceptibility for the specific bacterium. Results are returned to the originating device within 1 minute and shown to the user in tabular form. We demonstrated the capability of this platform using MTPs prepared with 17 antibiotic drugs targeting Gram-negative bacteria and tested 82 patient isolate MTPs of Klebsiella pneumoniae, achieving well turbidity accuracy of 98.19%, MIC accuracy of 95.15%, and drug susceptibility interpretation accuracy of 99.06%, meeting the FDA defined criteria for AST.

  7. [Antifungal activity of melanin in clinical isolates of Candida spp].

    Science.gov (United States)

    Fuentes, Marisol; Hernández, Romané; Gordillo, Diego; Amaro, José; Falconer, Mary A; Alburquenque, Claudio; Tapia, Cecilia V

    2014-02-01

    Melanocytes are cells located in epidermis and mucous membranes that synthesize melanin and cytokines. It is known that melanin has antimicrobial activity and that melanocytes are melanized in presence of microbial molecules. To study the antifungal activity of melanin on Candida spp. The minimum inhibitory concentration (MIC) to melanin was determined in 4 Candida ATCC strains (C. albicans SC5314, C. parapsilosis 22019, C. glabrata 2001, C. krusei 6258) and 56 clinical isolates of Candida spp. (33 C. albicans, 12 C. glabrata, 3 C. famata, 3 C. krusei, 3 C. parapsilosis, 2 C. tropicalis) using a broth microdilution method. In addition, the antifungal activity of melanocytes and mice melanoma cells was tested against C. albicans. Melanin inhibited the tested isolates, including the susceptible dose-dependent and fluconazole-resistant strains; MIC range and MIC50 were 0.09-50 μg/mL and 6.25 μg/mL, respectively. Pigmented cells lysates inhibited C. albicans. Melanin is able to inhibit clinical isolates of Candida spp. Melanization could be an important protective mechanism of melanocytes.

  8. Antibacterial and antifungal activities of some Mexican medicinal plants.

    Science.gov (United States)

    Ruiz-Bustos, E; Velazquez, C; Garibay-Escobar, A; García, Z; Plascencia-Jatomea, M; Cortez-Rocha, M O; Hernandez-Martínez, J; Robles-Zepeda, R E

    2009-12-01

    In Mexico about 4,000 plant species have some medicinal use. The aim of this work was to evaluate the antimicrobial activity of six Mexican medicinal plants against fungi and Gram-positive and Gram-negative bacteria. Methanolic extracts were prepared from the Mexican medicinal plants Amphypteringium adstrigens, Castella tortuosa, Coutarea latiflora, Ibervillea sonorae, Jatropha cuneata, and Selaginella lepidophylla. The antibacterial and antifungal activities of the plants were determined by the broth microdilution method and the radial growth inhibition assay, respectively. All Mexican plants tested showed antimicrobial activity. Among the six plant extracts analyzed, J. cuneata showed the highest growth-inhibitory activity against fungi, Gram-positive and Gram-negative bacteria (J. cuneata > A. adstrigens > C. latiflora > C. tortuosa > I. sonorae approximately S. lepidophylla). Shigella flexneri and Staphylococcus aureus were the most susceptible bacteria to plant extracts. Complete inhibition of S. flexneri growth was observed with J. cuneata methanolic extract at 90 microg/mL. This plant extract also showed the strongest antifungal activity against Fusarium verticillioides and Aspergillus niger. Our data suggest that the medicinal plants tested have important antimicrobial properties. This is the first report describing the antimicrobial activities of several of the Mexican medicinal plants used in this study.

  9. Differential susceptibility or diathesis stress? Testing longitudinal associations among parenting, temperament and children’s problem behavior

    NARCIS (Netherlands)

    Stoltz, S.E.M.J.; Beijers, R.; Smeekens, Sanny; Dekovic, M.

    2017-01-01

    In this study we investigated longitudinal associations among parenting, children's temperamental negative affectivity, and internalizing and externalizing behavior. Second, we tested whether findings confirmed the diathesis-stress model or differential susceptibility theory when conducting

  10. Drug susceptibility testing of Mycobacterium Avium subsp. Avium isolates from naturally infected domestic pigeons to avian tuberculosis

    Directory of Open Access Journals (Sweden)

    Kaveh Parvandar

    2016-01-01

    Conclusion: We suggest drug susceptibility testing for more nontuberculous mycobateria, particularly M. avium complex isolated from infected birds and humans, as well as molecular basics of drug sensitivity in order to detect resistance genes of pathogenic M. avium subsp. avium.

  11. Susceptibility testing of Actinobacillus pleuropneumoniae in Denmark. Evaluation of three different media of MIC-determinations and tablet diffusion tests.

    Science.gov (United States)

    Aarestrup, F M; Jensen, N E

    1999-02-12

    This study was conducted to compare the applicability of three different media in sensitivity testing of Actinobacillus pleuropneumoniae by means of MIC and tablet diffusion tests. The media used were: modified PPLO agar, chocolatized Mueller-Hinton-II and Columbia agar supplemented with NAD. Seven antimicrobial agents were tested: ceftiofur, enrofloxacin, penicillin, spectinomycin, tiamulin, trimethoprim + sulfadiazine and tylosin, against 40 randomly selected A. pleuropneumoniae isolates. In general, good agreement was found between results obtained with all combinations of media, most antimicrobials tested and the two-test systems. Some variations between media were observed for spectinomycin, tiamulin and tylosin. For ceftiofur and trimethoprim + sulfadiazine some isolates with low MIC-values were classified as resistant using tablet diffusion, indicating that the break points of resistance for these antimicrobials using the tablet diffusion tests need adjustment. Using current break points for resistance with MIC-determinations, all isolates tested susceptible to ceftiofur, enrofloxacin, penicillin, tiamulin and trimethoprim + sulfadiazine. A larger number of isolates tested resistant to spectinomycin and tylosin on all three media using both MIC determinations and tablet diffusion.

  12. ESBL Detection: Comparison of a Commercially Available Chromogenic Test for Third Generation Cephalosporine Resistance and Automated Susceptibility Testing in Enterobactericeae.

    Directory of Open Access Journals (Sweden)

    Mohamed Ramadan El-Jade

    Full Text Available Rapid detection and reporting of third generation cephalosporine resistance (3GC-R and of extended spectrum betalactamases in Enterobacteriaceae (ESBL-E is a diagnostic and therapeutic priority to avoid inefficacy of the initial antibiotic regimen. In this study we evaluated a commercially available chromogenic screen for 3GC-R as a predictive and/or confirmatory test for ESBL and AmpC activity in clinical and veterinary Enterobacteriaceae isolates. The test was highly reliable in the prediction of cefotaxime and cefpodoxime resistance, but there was no correlation with ceftazidime and piperacillin/tazobactam minimal inhibitory concentrations. All human and porcine ESBL-E tested were detected with exception of one genetically positive but phenotypically negative isolate. By contrast, AmpC detection rates lay below 30%. Notably, exclusion of piperacillin/tazobactam resistant, 3GC susceptible K1+ Klebsiella isolates increased the sensitivity and specificity of the test for ESBL detection. Our data further imply that in regions with low prevalence of AmpC and K1 positive E. coli strains chromogenic testing for 3GC-R can substitute for more time consuming ESBL confirmative testing in E. coli isolates tested positive by Phoenix or VITEK2 ESBL screen. We, therefore, suggest a diagnostic algorithm that distinguishes 3GC-R screening from primary culture and species-dependent confirmatory ESBL testing by βLACTATM and discuss the implications of MIC distribution results on the choice of antibiotic regimen.

  13. New insights into the mechanism of action of pyrazinamide, implications for susceptibility testing, and future regimens*

    Directory of Open Access Journals (Sweden)

    Richard M Anthony

    2016-01-01

    Although the exact mechanism of action of PZA is not known yet, it is widely accepted that PZA is a prodrug requiring transformation to pyrazinoic acid, the active form, by the mycobacterial enzyme encoded by the pncA gene. Most clinical resistance indeed appears to be a result of a diverse range of mutations in this gene and sequencing of the pncA gene has been shown to have excellent predictive power for PZA resistance. The wider availably of pncA sequencing in combination with databases of the phenotypic implications of these mutations has helped make genetic testing for PZA resistance a practical proposition. For the past decades, it has been generally accepted that an extracellular low pH is required for PZA activity but work in our laboratory [1] and others [2] has recently challenged this assumption. Alternative bacterial stresses, apart from a reduced pH of the growth media (such as reduced temperature, can also induce a PZA-susceptible phenotype. The characterization of spontaneous in vitro-resistant pyrazinoic acid mutants selected under neutral pH conditions suggests a key role for the pantothenate/coenzyme A biosynthetic pathway. This has profound implications for the mechanism of action of PZA as well as potentially the bacterial population against which PZA is active in the host. These findings will be discussed as well as their implications for further research and the future of PZA susceptibility testing.

  14. Comparison of Rosco Neo-Sensitabs with Oxoid paper disks in EUCAST disk diffusion antimicrobial susceptibility testing on Mueller-Hinton agar

    DEFF Research Database (Denmark)

    Justesen, U S; Acar, Ziyap; Olsson, K

    2013-01-01

    This study compared Neo-Sensitabs with Oxoid paper disks using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) disk diffusion antimicrobial susceptibility test on Mueller-Hinton agar. The EUCAST-recommended quality control strains (Escherichia coli ATCC 25922, Pseudomonas...... paper disks for EUCAST disk diffusion antimicrobial susceptibility testing on Mueller-Hinton agar....

  15. Vancomycin-resistant Enterococcus spp.: validation of susceptibility testing and in vitro activity of vancomycin, linezolid, tigecycline and daptomycin

    DEFF Research Database (Denmark)

    Rathe, Mathias; Kristensen, Lise; Ellermann-Eriksen, Svend

    2010-01-01

    Vancomycin-resistant enterococci (VRE) have emerged to become a significant nosocomial pathogen. However, detection may be challenging and treatment possibilities are limited. Reports of resistance to linezolide, daptomycin and tigecycline underline the need for reliable susceptibility testing...... with respect to these compounds. We evaluated the in vitro activity of vancomycin, linezolid, daptomycin and tigecycline against a panel of VRE and vancomycin-susceptible enterococci by broth microdilution (BMD). Etest for determination of minimum inhibitory concentration of these four antibiotics and two disc...... diffusion assays for detecting VRE and for susceptibility testing against tigecycline and linezolid were evaluated. Before susceptibility testing, all isolates were classified by polymerase chain reaction as vanA or vanB gene positive or vanA/B gene negative. Linezolid, daptomycin and tigecycline had...

  16. Use of linezolid susceptibility test results as a surrogate for the susceptibility of Gram-positive pathogens to tedizolid, a novel oxazolidinone

    OpenAIRE

    Zurenko, Gary; Bien, Paul; Bensaci, Mekki; Patel, Hina; Thorne, Grace

    2014-01-01

    Background Tedizolid is a novel oxazolidinone antibacterial with potent activity against a wide range of Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. Although tedizolid is approved by the US Food and Drug Administration (FDA) for treatment of patients with acute bacterial skin and skin structure infection, commercial susceptibility testing products for tedizolid are not currently available. This study evaluated the useful...

  17. Contributions of culture and antimicrobial susceptibility tests to the retreatment of patients with pulmonary tuberculosis

    Directory of Open Access Journals (Sweden)

    Bruno Horta Andrade

    2013-08-01

    Full Text Available Introduction This study evaluated the efficacy of retreatment of pulmonary tuberculosis (TB with regard to treatment outcomes and antimicrobial susceptibility testing (ST profiles. Methods This retrospective cohort study analyzed 144 patients treated at a referral hospital in Brazil. All of them had undergone prior treatment, were smear-positive for TB and received a standardized retreatment regimen. Fisher's 2-tailed exact test and the χ2 test were used; RRs and 95% CIs were calculated using univariate and multivariate binary logistic regression. Results The patients were cured in 84 (58.3% cases. Failure was associated with relapsed treatment and abandonment (n=34. Culture tests were obtained for 103 (71.5% cases; 70 (48.6% had positive results. ST results were available for 67 (46.5% cases; the prevalence of acquired resistance was 53.7%. There were no significant differences between those who achieved or not therapeutic success (p=0.988, despite being sensitive or resistant to 1 or more drugs. Rifampicin resistance was independently associated with therapeutic failure (OR: 4.4, 95% CI:1.12-17.37, p=0.034. For those cases in which cultures were unavailable, a 2nd model without this information was built. In this, return after abandonment was significantly associated with retreatment failure (OR: 3.59, 95% CI:1.17-11.06, p=0.026. Conclusions In this cohort, the general resistance profile appeared to have no influence on treatment outcome, except in cases of rifampicin resistance. The form of reentry was another independent predictor of failure. The use of bacterial culture identification and ST in TB management must be re-evaluated. The recommendations for different susceptibility profiles must also be improved.

  18. Nosocomial Candidiasis: Antifungal Stewardship and the Importance of Rapid Diagnosis.

    Science.gov (United States)

    Pfaller, Michael A; Castanheira, Mariana

    2016-01-01

    Candidemia and other forms of candidiasis are associated with considerable excess mortality and costs. Despite the addition of several new antifungal agents with improved spectrum and potency, the frequency of Candida infection and associated mortality have not decreased in the past two decades. The lack of rapid and sensitive diagnostic tests has led to considerable overuse of antifungal agents resulting in increased costs, selection pressure for resistance, unnecessary drug toxicity, and adverse drug interactions. Both the lack of timely diagnostic tests and emergence of antifungal resistance pose considerable problems for antifungal stewardship. Whereas antifungal stewardship with a focus on nosocomial candidiasis should be able to improve the administration of antifungal therapy in terms of drug selection, proper dose and duration, source control and de-escalation therapy, an important parameter, timeliness of antifungal therapy, remains a victim of slow and insensitive diagnostic tests. Fortunately, new proteomic and molecular diagnostic tools are improving the time to species identification and detection. In this review we will describe the potential impact that rapid diagnostic testing and antifungal stewardship can have on the management of nosocomial candidiasis. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. [Derivatives of 4-nitroso-aminopyrazole as antifungal agents].

    Science.gov (United States)

    Giori, P; Mazzotta, D; Vertuani, G; Guarneri, M; Pancaldi, D; Brunelli, A

    1981-12-01

    The synthesis of 4-nitroso-5-amminopyrazoles and of 4-nitroso-5-pyrazolylurethans and -ureas is described. The chemicals were tested for antifungal activity against Erysiphe graminis, Erysiphe cichoracearum, Puccinia recondita, Septoria apii and Rhizoctonia solani. A number of the described compounds showed some antifungal activity.

  20. Identification and antifungal activity of Streptomyces sp. S72 isolated ...

    African Journals Online (AJOL)

    The test of antifungal activity for several pathogens fungi causing invasive aspergillosis and systemic candidiasis revealed that the Streptomyces sp. S72 was a good moderate antifungal compound producer against Aspergillus fumigatus and Candida albicans, and had no activity against Aspergillus flavus, Aspergillus ...

  1. Antifungal activity of crude extracts of Gladiolus dalenii van Geel ...

    African Journals Online (AJOL)

    Bulb extracts of Gladiolus dalenii reportedly used in the treatment of fungal infections in HIV/AIDS patients in the Lake Victoria region were tested for antifungal activity using the disc diffusion assay technique. Commercially used antifungal drugs, Ketaconazole and Griseofulvin (Cosmos Pharmaceuticals) were used as ...

  2. Differential Susceptibility to Social Contexts : Putting "For Better and For Worse" to the test

    NARCIS (Netherlands)

    Slagt, M.I.

    2017-01-01

    The differential susceptibility model asserts that individuals vary in their general susceptibility to environmental influences.Crucially, the very children that are disproportionately vulnerable to harsh and low-quality parenting, may benefit disproportionately from supportive and high-quality

  3. Evaluation of Etest for Susceptibility Testing of Multidrug-Resistant Isolates of Mycobacterium tuberculosis†

    Science.gov (United States)

    Hazbón, Manzour Hernando; del Socorro Orozco, Maria; Labrada, Luz Angela; Tovar, Rafael; Weigle, Kristen A.; Wanger, Audrey

    2000-01-01

    To prescribe effective treatment schemes for patients with tuberculosis, more-efficient susceptibility testing techniques for Mycobacterium tuberculosis are needed, especially in regions with multidrug resistance. Etest (AB BIODISK, Solna, Sweden) is a simple technique that provides quantitative drug susceptibility results for M. tuberculosis in 5 to 10 days from a culture grown at low cost. The performance of Etest was compared to that of the reference proportion method, using 95 M. tuberculosis clinical isolates of which 42.1% (40 of 95) were resistant to at least one antibiotic by the reference method. Overall agreement between Etest and the reference method was 98.9% (94 of 95) for detection of multidrug resistance; for resistance to individual drugs, agreement was 97.9% (93 of 95) for rifampin, 96.0% (92 of 95) for ethambutol, 94.7% (90 of 95) for isoniazid, and 85.3% (81 of 95) for streptomycin. This study supports the utility of Etest for timely detection of drug resistance in M. tuberculosis and for use in tuberculosis control programs. PMID:11101602

  4. Drug susceptibility testing of clinical isolates of streptococci and enterococci by the Phoenix automated microbiology system

    Directory of Open Access Journals (Sweden)

    Sokeng Gertrude

    2007-05-01

    Full Text Available Abstract Background Drug resistance is an emerging problem among streptococcal and enterococcal species. Automated diagnostic systems for species identification and antimicrobial susceptibility testing (AST have become recently available. We evaluated drug susceptibility of clinical isolates of streptococci and enterococci using the recent Phoenix system (BD, Sparks, MD. Diagnostic tools included the new SMIC/ID-2 panel for streptococci, and the PMIC/ID-14 for enterococci. Two-hundred and fifty isolates have been investigated: β-hemolytic streptococci (n = 65, Streptococcus pneumoniae (n = 50, viridans group streptococci (n = 32, Enterococcus faecium (n = 40, Enterococcus faecalis (n = 43, other catalase-negative cocci (n = 20. When needed, species ID was determined using molecular methods. Test bacterial strains were chosen among those carrying clinically-relevant resistance determinants (penicillin, macrolides, fluoroquinolones, glycopeptides. AST results of the Phoenix system were compared to minimal inhibitory concentration (MIC values measured by the Etest method (AB Biodisk, Solna, Sweden. Results Streptococci: essential agreement (EA and categorical agreement (CA were 91.9% and 98.8%, respectively. Major (ME and minor errors (mE accounted for 0.1% and 1.1% of isolates, respectively. No very major errors (VME were produced. Enterococci: EA was 97%, CA 96%. Small numbers of VME (0.9%, ME (1.4% and mE (2.8% were obtained. Overall, EA and CA rates for most drugs were above 90% for both genera. A few VME were found: a teicoplanin and high-level streptomycin for E. faecalis, b high-level gentamicin for E. faecium. The mean time to results (± SD was 11.8 ± 0.9 h, with minor differences between streptococci and enterococci. Conclusion The Phoenix system emerged as an effective tool for quantitative AST. Panels based on dilution tests provided rapid and accurate MIC values with regard to clinically-relevant streptococcal and enterococcal

  5. Evaluation of rapid alternative methods for drug susceptibility testing in clinical isolates of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Luciano Mengatto

    2006-08-01

    Full Text Available A study was carried out to compare the performance of a commercial method (MGIT and four inexpensive drug susceptibility methods: nitrate reductase assay (NRA, microscopic observation drug susceptibility (MODS assay, MTT test, and broth microdilution method (BMM. A total of 64 clinical isolates of Mycobacterium tuberculosis were studied. The Lowenstein-Jensen proportion method (PM was used as gold standard. MGIT, NRA, MODS, and MTT results were available on an average of less than 10 days, whereas BMM results could be reported in about 20 days. Most of the evaluated tests showed excellent performance for isoniazid and rifampicin, with sensitivity and specificity values > 90%. With most of the assays, sensitivity for ethambutol was low (62-87% whereas for streptomycin, sensitivity values ranged from 84 to 100%; NRA-discrepancies were associated with cultures with a low proportion of EMB-resistant organisms while most discrepancies with quantitative tests (MMT and BMM were seen with isolates whose minimal inhibitory concentrations fell close the cutoff. MGIT is reliable but still expensive. NRA is the most inexpensive and easiest method to perform without changing the organization of the routine PM laboratory performance. While MODS, MTT, and BMM, have the disadvantage from the point of view of biosafety, they offer the possibility of detecting partial resistant strains. This study shows a very good level of agreement of the four low-cost methods compared to the PM for rapid detection of isoniazid, rifampicin and streptomycin resistance (Kappa values > 0.8; more standardization is needed for ethambutol.

  6. Lyophilized microculture susceptibility test for ketoconazole, miconazole, clotrimazole, and griseofulvin against dermatophytes.

    Science.gov (United States)

    Granade, T C; Mothershead, M A; Artis, W M

    1983-07-01

    A lyophilized microculture antimycotic susceptibility testing system for ketoconazole, miconazole, griseofulvin, and clotrimazole is described. Microculture plates were loaded with 100 microliters of medium and 10 microliters of appropriate concentrations of the four antimycotics and were lyophilized to complete dryness. The lyophilized plates were stored at -70 degrees C or 4 degrees C or in a desiccator at 25 degrees C. Samples from each storage condition were rehydrated at 1, 2, 3, 4, 5, 6, 8, 10, and 12 months and inoculated with Trichophyton mentagrophytes (Robin) Blanchard ATCC 18748. All of the minimal inhibitory concentrations (MICs) generated from the lyophilized microcultures were within one experimental dilution of MICs derived from fresh microcultures. The ability of reconstituted lyophilized microcultures to consistently produce MICs comparable to MICs derived from fresh microcultures was characterized. Nine dermatophyte isolates were tested five times each over a 70-day period. The MICs derived were reproducible and comparable to MICs determined by freshly prepared microculture tests. Lyophilization of freshly prepared antimycotic-containing microcultures does not alter the MIC resolution of the testing system and provides an effective method of storage of prepared antimycotic tests for ketoconazole, miconazole, clotrimazole, and griseofulvin.

  7. Can disc diffusion susceptibility tests assess the antimicrobial activity of engineered nanoparticles?

    Science.gov (United States)

    Kourmouli, Angeliki; Valenti, Marco; van Rijn, Erwin; Beaumont, Hubertus J. E.; Kalantzi, Olga-Ioanna; Schmidt-Ott, Andreas; Biskos, George

    2018-03-01

    The use of disc diffusion susceptibility tests to determine the antibacterial activity of engineered nanoparticles (ENPs) is questionable because their low diffusivity practically prevents them from penetrating through the culture media. In this study, we investigate the ability of such a test, namely the Kirby-Bauer disc diffusion test, to determine the antimicrobial activity of Au and Ag ENPs having diameters from 10 to 40 nm on Escherichia coli cultures. As anticipated, the tests did not show any antibacterial effects of Au nanoparticles (NPs) as a result of their negligible diffusivity through the culture media. Ag NPs on the other hand exhibited a strong antimicrobial activity that was independent of their size. Considering that Ag, in contrast to Au, dissolves upon oxidation and dilution in aqueous solutions, the apparent antibacterial behavior of Ag NPs is attributed to the ions they release. The Kirby-Bauer method, and other similar tests, can therefore be employed to probe the antimicrobial activity of ENPs related to their ability to release ions rather than to their unique size-dependent properties. [Figure not available: see fulltext.

  8. Genetic testing for breast cancer susceptibility: awareness and interest among women in the general population.

    Science.gov (United States)

    Tambor, E S; Rimer, B K; Strigo, T S

    1997-01-10

    Previous research has suggested that demand for genetic testing for breast cancer susceptibility may be quite high, even among those at relatively low risk of carrying a mutation. This study examined the extent to which a group of female HMO enrollees were aware of the discovery of the BRCA1 gene and, without having received detailed information about the test, whether they would be interested in being tested to find out if they have the gene. Factors associated with awareness of and interest in testing were also examined. Four hundred seventy-three women age 50 and over, almost all of whom did not have an increased risk of breast cancer based on family history, were surveyed by telephone. Fifty-one percent of respondents had heard about the discovery of a breast cancer gene. In logistic regression analysis, women who described themselves as comfortable financially, had at least some college education, and were premenopausal were more likely to have heard of the gene discovery than women who were not comfortable financially, had no more than a high school education, and were postmenopausal. Sixty-nine percent of the respondents said that they would be interested in being tested to find out if they had a breast cancer gene. Women who were younger than 60, white, believed their family would benefit if they had a mammogram, and believed that regular mammograms give them a feeling of control over their health, were more likely to be interested in testing than those who were 60 or older, African-American or other, and did not believe that their family would benefit if they had a mammogram or that mammograms give them a feeling of control over their health. These findings have implications for education and counseling. Women who express an interest in being tested must be made fully aware of the limitations and possible consequences of testing. Special efforts may be needed to make information about testing available to women who have low levels of education.

  9. Medium-dependent zone size discrepancies associated with susceptibility testing of group D streptococci against various cephalosporins.

    OpenAIRE

    Sahm, D F; Baker, C N; Jones, R N; Thornsberry, C

    1983-01-01

    Mueller-Hinton (MH) agar media from various commercial sources, either supplemented or not supplemented with 5% sheep blood, were studied to determine their effect on disk diffusion susceptibility testing results obtained with 90 strains of group D streptococci and four cephalosporins. The cephalosporins investigated included cephalothin, cefamandole, moxalactam, and cefotaxime. Results showed that a number of Streptococcus faecalis and Streptococcus faecium strains were susceptible to cephal...

  10. Design, characterization, teratogenicity testing, antibacterial, antifungal and DNA interaction of few high spin Fe(II) Schiff base amino acid complexes

    Science.gov (United States)

    Abdel-Rahman, Laila H.; El-Khatib, Rafat M.; Nassr, Lobna A. E.; Abu-Dief, Ahmed M.; Lashin, Fakhr El-Din

    2013-07-01

    In this study, new Fe(II) Schiff base amino acid chelates derived from the condensation of o-hydroxynaphthaldehyde with L-alanine, L-phenylalanine, L-aspartic acid, L-histidine and L-arginine were synthesized and characterized via elemental, thermogravimetric analysis, molar conductance, IR, electronic, mass spectra and magnetic moment measurements. The stoichiometry and the stability constants of the complexes were determined spectrophotometrically. Correlation of all spectroscopic data suggested that Schiff bases ligands exhibited tridentate with ONO sites coordinating to the metal ions via protonated phenolic-OH, azomethine-N and carboxylate-O with the general formulae [Fe(HL)2]·nH2O. But in case of L-histidine, the ligand acts as tetradentate via deprotonated phenolic-OH, azomethine-N, carboxylate-O and N-imidazole ring ([FeL(H2O)2]·2H2O), where HL = mono anion and L = dianion of the ligand. The structure of the prepared complexes is suggested to be octahedral. The prepared complexes were tested for their teratogenicity on chick embryos and found to be safe until a concentration of 100 μg/egg with full embryos formation. Moreover, the interaction between CT-DNA and the investigated complexes were followed by spectrophotometric and viscosity measurements. It was found that, the prepared complexes bind to DNA via classical intercalative mode and showed a different DNA activity with the sequence: nhi > nari > nali > nasi > nphali. Furthermore, the free ligands and their complexes are screened for their in vitro antibacterial and antifungal activity against three types of bacteria, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus and three types of anti fungal cultures, Penicillium purpurogenium, Aspergillus flavus and Trichotheium rosium in order to assess their antimicrobial potential. The results show that the metal complexes are more reactive with respect to their corresponding Schiff base amino acid ligands.

  11. Status of NRC approval of EPRI electromagnetic interference susceptibility testing guidelines for digital equipment

    International Nuclear Information System (INIS)

    James, R.W.; Shank, J.W.; Yoder, C.

    1996-01-01

    Historically, nuclear power plants installing digital equipment have been required to conduct expensive, site-specific electromagnetic interference (EMI) surveys to demonstrate that EMI will not affect the operation of sensitive electronic equipment. Consequently, EPRI formed a Utility Working Group which developed a set of generic EMI susceptibility testing guidelines, which were published as an EPRI report in September 1994. These guidelines are based upon EMI survey data obtained from several different plants and include criteria for determining their applicability. The Working Group interacted with NRC staff to obtain NRC approval. In April 1996, the NRC issued a Safety Evaluation Report (SER) endorsing the guidelines as a valid means of demonstrating EMI compatibility. The issuance of this SER was conditional on issuing a revision to the EPRI EMI Guidelines. This paper summarizes the guidelines, the NRC SER, and the current status of Revision 1 to the report

  12. Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes.

    Science.gov (United States)

    Poirel, Laurent; Jayol, Aurélie; Nordmann, Patrice

    2017-04-01

    SUMMARYPolymyxins are well-established antibiotics that have recently regained significant interest as a consequence of the increasing incidence of infections due to multidrug-resistant Gram-negative bacteria. Colistin and polymyxin B are being seriously reconsidered as last-resort antibiotics in many areas where multidrug resistance is observed in clinical medicine. In parallel, the heavy use of polymyxins in veterinary medicine is currently being reconsidered due to increased reports of polymyxin-resistant bacteria. Susceptibility testing is challenging with polymyxins, and currently available techniques are presented here. Genotypic and phenotypic methods that provide relevant information for diagnostic laboratories are presented. This review also presents recent works in relation to recently identified mechanisms of polymyxin resistance, including chromosomally encoded resistance traits as well as the recently identified plasmid-encoded polymyxin resistance determinant MCR-1. Epidemiological features summarizing the current knowledge in that field are presented. Copyright © 2017 American Society for Microbiology.

  13. Specific heat, susceptibility and frequency of inharmonic oscillator a test of the variational methods

    International Nuclear Information System (INIS)

    Silva, L.R. da; Tsallis, C.

    1978-05-01

    The quality of approximation of the Variational Method in Statistical Mechanics is tested in the case of a classical anharmonic oscillator with a potential of the x 2 sup(n)-type and also of the (x 2 )+(x 4 )-type. Comparison between the variational and exact results for the specific heat, the electric susceptibility and the mean oscillation frequence, shows that the Variational Method leads to surprisingly good results in the whole domain of temperatures (from T=0 to T→infinite). In the particular case of the specific heat, this method leads to the exact result for a potential of the x 2 (supn)-type, and gives, for a potential of the (x 2 )+(x 4 )-type, the exact or almost exact asymptotic behaviours (T→0 and T→infinite) [pt

  14. En Route towards European Clinical breakpoints for veterinary antimicrobial susceptibility testing

    DEFF Research Database (Denmark)

    Toutain, Pierre Louis; Bousquet-Mélou, Alain; Damborg, Peter

    2017-01-01

    VetCAST is the EUCAST sub-committee for Veterinary Antimicrobial Susceptibility Testing. Its remit is to define clinical breakpoints (CBPs) for antimicrobial drugs (AMDs) used in veterinary medicine in Europe. This position paper outlines the procedures and reviews scientific options to solve...... cure. For the latter, VetCAST acknowledges the paucity of such data in veterinary medicine. When a CBP cannot be established, VetCAST will recommend use of ECOFF as surrogate. For decision steps, VetCAST will follow EUCAST procedures involving transparency, consensus and independence. Vet...... species breed considerations and several other variable factors not relevant to human medicine. Each CBP will be based on consideration of: (i) an epidemiological cut-off value (ECOFF) - the highest MIC that defines the upper end of the wild-type MIC distribution; (ii) a PK/PD breakpoint obtained from pre...

  15. Ethical, legal and social implications of prenatal and preimplantation genetic testing for cancer susceptibility.

    Science.gov (United States)

    Wang, C-W; Hui, E C

    2009-01-01

    With the progress in cancer genetics and assisted reproductive technologies, it is now possible for cancer gene mutation carriers not only to reduce cancer mortality through the targeting of surveillance and preventive therapies, but also to avoid the birth of at-risk babies through the choice of different means of reproduction. Thus, the incidence of hereditary cancer syndromes may be decreased in the future. The integration of cancer genetic testing and assisted reproductive technologies raises certain ethical, legal and social issues beyond either genetic testing or assisted reproductive technology itself. In this paper, the reproductive decisions/choices of at-risk young couples and the ethical, legal and social concerns of prenatal genetic testing and preimplantation genetic diagnosis for susceptibility to hereditary cancer syndromes are discussed. Specifically, three ethical principles related to the integration of cancer genetic testing and assisted reproductive technologies, i.e. informed choice, beneficence to children and social justice, and their implications for the responsible translation of these medical techniques into common practice of preventive medicine are highlighted.

  16. Miniaturized Antimicrobial Susceptibility Test by Combining Concentration Gradient Generation and Rapid Cell Culturing

    Directory of Open Access Journals (Sweden)

    Samuel C. Kim

    2015-10-01

    Full Text Available Effective treatment of bacterial infection relies on timely diagnosis and proper prescription of antibiotic drugs. The antimicrobial susceptibility test (AST is one of the most crucial experimental procedures, providing the baseline information for choosing effective antibiotic agents and their dosages. Conventional methods, however, require long incubation times or significant instrumentation costs to obtain test results. We propose a lab-on-a-chip approach to perform AST in a simple, economic, and rapid manner. Our assay platform miniaturizes the standard broth microdilution method on a microfluidic device (20 × 20 mm that generates an antibiotic concentration gradient and delivers antibiotic-containing culture media to eight 30-nL chambers for cell culture. When tested with 20 μL samples of a model bacterial strain (E. coli ATCC 25922 treated with ampicillin or streptomycin, our method allows for the determination of minimum inhibitory concentrations consistent with the microdilution test in three hours, which is almost a factor of ten more rapid than the standard method.

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

    Science.gov (United States)

    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

  18. Antifungal activity of linalool in cases of Candida spp. isolated from individuals with oral candidiasis

    Directory of Open Access Journals (Sweden)

    I. J. Dias

    2017-09-01

    Full Text Available Abstract This study analyzed the antifungal activity of phytoconstituents from linalool on Candida spp. strains, in vitro, isolated from patients with clinical diagnoses of oral candidiasis associated with the use of a dental prosthesis. Biological samples were collected from 12 patients using complete dentures or removable partial dentures and who presented mucous with diffuse erythematous or stippled features, indicating a clinical diagnosis of candidiasis. To identify fungal colonies of the genus Candida, samples were plated onto CHROMagar Candida®. The antifungal activity of linalool, a monoterpene unsaturated constituent of basil oil, was performed using the broth microdilution technique. Then, the minimum inhibitory concentration (MIC, the two subsequent stronger concentrations and the positive controls were subcultured on Sabouraud Dextrose Agar plates to determine the minimum fungicidal concentration (MFC. The experiments were performed in triplicate and nystatin was used as a positive control in all tests. Diagnoses of oral candidiasis were verified in eight patients (66.6% and the most prevalent fungal species was Candida albicans (37.5%, followed by Candida krusei (25.0%; and Candida tropicalis (4.2%. The best antifungal activity of linalool was observed on Candida tropicalis (MIC = 500 mg/mL, followed by Candida albicans (MIC = 1.000 mg/mL, and Candida krusei (MIC = 2.000 mg/mL.Under the study conditions and based on the results obtained, it can be concluded that the Candida strains tested were susceptible to linalool.

  19. Multicenter Evaluation of the BD Phoenix Automated Microbiology System for Antimicrobial Susceptibility Testing of Streptococcus Species▿

    Science.gov (United States)

    Richter, Sandra S.; Howard, Wanita J.; Weinstein, Melvin P.; Bruckner, David A.; Hindler, Janet F.; Saubolle, Michael; Doern, Gary V.

    2007-01-01

    This multicenter study evaluated the BD Phoenix Automated Microbiology System STREP panel (BD Diagnostic Systems). Antimicrobial susceptibility testing (AST) with 13 agents was performed on 2,013 streptococci (938 Streptococcus pneumoniae isolates; 396 group B streptococci [GBS]; 369 viridans group streptococci [VGS]; 290 beta-hemolytic streptococcus groups A, C, and G; and 20 other streptococci) with the Phoenix system and a broth microdilution reference method. Clinical and challenge isolates were tested against cefepime, cefotaxime (CTX), ceftriaxone (CTR), clindamycin (CLI), erythromycin (ERY), gatifloxacin, levofloxacin, linezolid, meropenem, penicillin (PEN), tetracycline (TET), trimethoprim-sulfamethoxazole, and vancomycin. Clinical isolates with major errors or very major errors (VMEs) were retested in duplicate by both methods. The final results for clinical isolates showed the following trends. For all of the organism-antimicrobial agent combinations tested, categorical agreement (CA) was 92 to 100%, with one exception—VGS-PEN (87% CA; all errors were minor). For S. pneumoniae, there was one major error with CLI (0.1%) and one or two VMEs with CTX (4%), CTR (4.5%), ERY (0.9%), and TET (0.7%). For groups A, C, and G, the CA was 97 to 100% and the only VMEs were resolved by additional reference laboratory testing. For GBS, there was only one VME (TET, 0.3%) and D-zone testing of 23 isolates with CLI major errors (one isolate unavailable) revealed inducible CLI resistance. For VGS, the major error rates were 0 to 3% and VMEs occurred with seven agents (3.5 to 7.1%). The mean times required for organism groups to generate results ranged from 8.4 to 9.4 h. The Phoenix system provided reliable and rapid AST results for most of the organism-antimicrobial agent combinations tested. PMID:17652483

  20. Correcting a Fundamental Flaw in the Paradigm for Antimicrobial Susceptibility Testing

    Directory of Open Access Journals (Sweden)

    Selvi C. Ersoy

    2017-06-01

    Full Text Available The emergence and prevalence of antibiotic-resistant bacteria are an increasing cause of death worldwide, resulting in a global ‘call to action’ to avoid receding into an era lacking effective antibiotics. Despite the urgency, the healthcare industry still relies on a single in vitro bioassay to determine antibiotic efficacy. This assay fails to incorporate environmental factors normally present during host-pathogen interactions in vivo that significantly impact antibiotic efficacy. Here we report that standard antimicrobial susceptibility testing (AST failed to detect antibiotics that are in fact effective in vivo; and frequently identified antibiotics that were instead ineffective as further confirmed in mouse models of infection and sepsis. Notably, AST performed in media mimicking host environments succeeded in identifying specific antibiotics that were effective in bacterial clearance and host survival, even though these same antibiotics failed in results using standard test media. Similarly, our revised media further identified antibiotics that were ineffective in vivo despite passing the AST standard for clinical use. Supplementation of AST medium with sodium bicarbonate, an abundant in vivo molecule that stimulates global changes in bacterial structure and gene expression, was found to be an important factor improving the predictive value of AST in the assignment of appropriate therapy. These findings have the potential to improve the means by which antibiotics are developed, tested, and prescribed.

  1. Predicament in detection and reporting of extended spectrum beta lactamase production in routine antibiotic susceptibility testing

    International Nuclear Information System (INIS)

    Butt, T.; Butt, E.; Raza, S.

    2017-01-01

    This descriptive and cross-sectional study was planned to determine the dilemma of inadvertent detection of extended spectrum beta lactamase (ESBL) production in Enterobacteriaceaewhen using inhibition zone size of antibiotic disks of Cefotaxime or Aztreonam in routine antibiotic susceptibility testing as recommended by Clinical Laboratory Standards Institute (CLSI). Screening and double disk tests were adopted as per CLSI. Escherichia coli ATCC 25922 was used as control strain. Among total specimens of 5346, there were 348 isolates of Escherichia coli(n=235), Klebsiella pneumonia (n=92), Klebsiella oxytoca(n=3) or Proteus mirabilus(n=18). The screening method recommended by CLSI significantly falsely detected ESBL production in 79 (32.3%) isolates (p<0.0001). ESBL detection is important as its frequency is high and treatment of the infection varies with the presence and absence of ESBL. To avoid false reporting, proper phenotypic detection of ESBL confirmatory method-like double-disk synergy test, should be used routinely. (author)

  2. Drug susceptibility testing of Mycobacterium tuberculosis by the broth microdilution method with 7H9 broth

    Directory of Open Access Journals (Sweden)

    Ahmet Yilmaz Coban

    2004-02-01

    Full Text Available In this study, we have evaluated the broth microdilution method (BMM for susceptibility testing of Mycobacterium tuberculosis. A total of 43 clinical isolates of M. tuberculosis and H37Rv as a control strain were studied. All isolates were tested by the proportion method and the BMM for isoniazid (INH, rifampicin (RIF, streptomycin (STR, and ethambutol (ETM. The proportion method was carried out according to the National Committee for Clinical Laboratory Standards (NCCLS on Löwenstein-Jensen (LJ medium. The BMM was carried out using 7H9 broth with 96 well-plates. All strains were tested at 3.2-0.05 µg/ml, 16-0.25 µg/ml, 32-0.5 µg/ml, and 32-0.5 µg/ml concentrations for INH, RIF, STR, and ETM, respectively. When the BMM was compared with the proportion method, sensitivity was 100, 100, 96.9, and 90.2%, while specificity was 100, 85.7, 90.9, and 100% for INH, RIF, STR, and ETM, respectively. The plates were examined 7, 10, 14, and 21 days after incubation. The majority of the result were obtained at 14th days after incubation, while the proportion method result were ended in 21-28 days. According to our results, it may be suggested that the BMM is suitable for early determining of multidrug-resistance-M. tuberculosis strains in developed or developing countries.

  3. A prospective study of the impact of genetic susceptibility testing for BRCA1/2 or HNPCC on family relationships

    NARCIS (Netherlands)

    van Oostrom, Iris; Meijers-Heijboer, Hanne; Duivenvoorden, Hugo J.; Brocker-Vriends, Annette H. J. T.; van Asperen, Chhstl J.; Sijmons, Rolf H.; Seynaeve, Caroline; Van Gool, Arthur R.; Klijn, Jan G. M.; Riedijk, Samantha R.; van Dooren, Silvia; Tibben, Aad

    This study assessed the impact of genetic testing for cancer susceptibility on family relationships and determinants of adverse consequences for family relationships. Applicants for genetic testing of a known familial pathogenic mutation in BRCA1/2 or a HNPCC related gene (N = 271) rated the

  4. A prospective study of the impact of genetic susceptibility testing for BRCA1/2 or HNPCC on family relationships

    NARCIS (Netherlands)

    van Oostrom, Iris; Meijers-Heijboer, Hanne; Duivenvoorden, Hugo J.; Bröcker-Vriends, Annette H. J. T.; van Asperen, Christi J.; Sijmons, Rolf H.; Seynaeve, Caroline; van Gool, Arthur R.; Klijn, Jan G. M.; Riedijk, Samantha R.; van Dooren, Silvia; Tibben, Aad

    2007-01-01

    This study assessed the impact of genetic testing for cancer susceptibility on family relationships and determinants of adverse consequences for family relationships. Applicants for genetic testing of a known familial pathogenic mutation in BRCA1/2 or a HNPCC related gene (N=271) rated the

  5. A prospective study of the impact of genetic susceptibility testing for BRCA1/2 or HNPCC on family relationships.

    NARCIS (Netherlands)

    Oostrom, I.I.H. van; Meijers-Heijboer, H.; Duivenvoorden, H.J.; Brocker-Vriends, A.H.; Asperen, C.J. van; Sijmons, R.H.; Seynaeve, C.; Gool, A.R. van; Klijn, J.G.M.; Riedijk, S.R.; Dooren, S. van; Tibben, A.

    2007-01-01

    This study assessed the impact of genetic testing for cancer susceptibility on family relationships and determinants of adverse consequences for family relationships. Applicants for genetic testing of a known familial pathogenic mutation in BRCA1/2 or a HNPCC related gene (N=271) rated the

  6. Antifungal Activity of Brazilian Propolis Microparticles against Yeasts Isolated from Vulvovaginal Candidiasis

    Directory of Open Access Journals (Sweden)

    Kelen Fátima Dalben Dota

    2011-01-01

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

  7. Evaluation of the antifungal properties of nystatin-salicylic acid ...

    African Journals Online (AJOL)

    The in vitro antifungal activity of nystatin-salicylic acid combinations against clinical isolates of Candida albicans was investigated separately using the overlay inoculum susceptibility disc, the decimal assay for additively (DDA) and the rate of time kill methods. The minimum inhibitory concentrations (MIC) of the individual ...

  8. The antifungal activity and cytotoxicity of silver containing denture ...

    African Journals Online (AJOL)

    The antifungal activity and cytotoxicity of silver containing denture base material. A Kurt, G Erkose-Genc, M Uzun, Z Emrence, D Ustek, G Isik-Ozkol. Abstract. Objective: Denture base materials are susceptible to fungal adhesion, which is an important etiological issue in the pathogenesis of denture stomatitis. The purpose of ...

  9. Standardization of hyphal growth inhibition rate as a means of evaluating Microsporum spp. in vitro susceptibility to terbinafine, griseofulvin, and ciclopiroxolamine.

    Science.gov (United States)

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

    2011-10-01

    Reference methods for antifungal susceptibility tests recommend the use of conidia as inoculum. However, some isolates produce few conidia, while the invasive form of filamentous fungi in general is hyphae making susceptibility tests infeaseble. These facts suggest that other than conidia broth dilution method is required for susceptibility tests. The aim of this study was to clarify if the hyphal growth inhibition rate could be used as a method of determining the antifungal susceptibility of genus Microsporum. For this reason, a method which traces hyphal tips automatically and measures their growth rate was standardized for Microsporum spp. Control growth curves and test growth curves obtained by real-time observation of the hyphae groups responses to different concentrations of terbinafine, griseofulvin, and ciclopiroxolamine were used to compare with minimum inhibitory concentrations (MICs) obtained by conidia broth microdilution method. A visible reduction in the growth inhibition rate was observed when hyphal activity was evaluated using the third or fourth serial two-fold dilution below the MIC determined by broth microdilution for terbinafine and ciclopiroxolamine. For griseofulvin, this reduction occurred after the fifth dilution below the MIC. This study highlights the importance of the inoculum type used to determine the in vitro susceptibility of Microsporum strains. We conclude that measurement of hyphal growth inhibition, despite being time consuming, could be a suitable method for evaluating antifungal susceptibility, particularly for fungi as Microsporum spp. that produce a small (or not at all) number of conidia.

  10. Bile Culture and Susceptibility Testing of Malignant Biliary Obstruction via PTBD

    Energy Technology Data Exchange (ETDEWEB)

    Yu Haipeng; Guo Zhi, E-mail: jieruke@yahoo.com.cn; Xing Wenge; Guo Xiuying; Liu Fang; Li Baoguo [Tinajin Medical University Cancer Institute and Hospital, Department of Interventional Therapy, Tianjin Key Cancer Prevention and Treatment Laboratory (China)

    2012-10-15

    Purpose: To assess the information obtained by bile culture and susceptibility testing for malignant biliary obstruction by a retrospective one-center study. Methods: A total of 694 patients with malignant biliary obstruction received percutaneous transhepatic biliary drainage during the period July 2003 to September 2010, and subsequently, bile specimens were collected during the procedure. Among the 694 patients, 485 were men and 209 were women, ranging in age from 38 to 78 years (mean age 62 years). Results: A total of 42.9% patients had a positive bile culture (298 of 694). Further, 57 species of microorganisms and 342 strains were identified; gram-positive bacteria accounted for 50.9% (174 of 342) and gram-negative bacteria accounted for 41.5% (142 of 342) of these strains. No anaerobes were obtained by culture during this study. The most common microorganisms were Enterococcus faecalis (41 of 342, 11.9%), Escherichia coli (34 of 342, 9.9%), Klebsiella pneumoniae (28 of 342, 8.2%), Staphylococcus epidermidis (19 of 342, 5.5%), Enterococcus (18 of 342, 5.3%), and Enterobacter cloacae (16 of 342, 4.7%). The percentage of {beta}-lactamase-producing gram-positive bacteria was 27.6% (48 of 174), and the percentage of gram-negative bacteria was 19.7% (28 of 142). The percentage of enzyme-producing Escherichia coli was 61.7% (21 of 34). Conclusion: The bile cultures in malignant biliary obstruction are different from those in the Tokyo Guidelines and other benign biliary obstruction researches, which indicates that a different antibacterial therapy should be applied. Thus, knowledge of the antimicrobial susceptibility data could aid in the better use of antibiotics for the empirical therapy of biliary infection combined with malignant biliary obstruction.

  11. Cryptoccocal meningitis in Yaoundé (Cameroon) HIV infected patients: Diagnosis, frequency and Cryptococcus neoformans isolates susceptibility study to fluconazole.

    Science.gov (United States)

    Kammalac Ngouana, T; Dongtsa, J; Kouanfack, C; Tonfack, C; Fomena, S; Mallié, M; Delaporte, E; Boyom, F-Fekam; Bertout, S

    2015-03-01

    Cryptococcal meningitis is a mycosis encountered especially in patients with Acquired Immunodeficiency Syndrome and is fatal in the absence of treatment. Information on epidemiology, diagnosis and susceptibility profile to antifungal drugs, are scarce in Cameroon. Authors evaluated the diagnosis possibilities of the cryptococcal meningitis in Cameroon, and studied the antifungal susceptibility of isolated strains to fluconazole, used as first line treatment of the disease in Cameroon. Between December 2009 and July 2011, 146 cerebrospinal fluids obtained from HIV patients with suspicion of meningitis were analysed. The diagnosis procedure involved macroscopic and cyto-chemical analysis, India ink test, culture on Sabouraud chloramphenicol medium and antigen latex agglutination test. Antifungal susceptibility testing of isolated strains to fluconazole was done by the E-test(®) method. The diagnosis of cryptococcal meningitis gave 28.08% positive cases. Among these patients, 80% were at stages III and IV and 20% at stage I of the HIV infection, according to the WHO previous classification. Cyto-chemical analysis showed current findings in the case of cryptococcal meningitis. India ink test and latex agglutination test exhibited very high sensitivity and specificity (>94%). Fluconazole antifungal susceptibility testing gave MICs lower than 32μg/mL to 92.7% of isolated strains and MICs greater than this value to 7.3% of isolates. These results showed that cryptococcal meningitis remains a real problem among HIV infected patients in Yaoundé. The emergence of fluconazole reduced susceptibility strains is worrying. Nevertheless, efficacy of rapid detection tests is interesting because this will help in rapid diagnosis and treatment of patients. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  12. [Application of the BACspreader™ Microbe Dispersion Counter in drug susceptibility test onMycobacterium tuberculosis].

    Science.gov (United States)

    Jiang, Y; Li, J; Zhang, Y Y; Wu, J; Wang, L L; Yu, C L; Shen, X; Zhu, G F

    2017-04-12

    Objective: To evaluate the application of the BACspreader™ Microbe Dispersion Counter in drug susceptibility test (DST) on Mycobacterium tuberculosis (MTB). Methods: The MTB strains were dispersed and diluted to 1.0 McFarland standard turbidity, by means of BACspreader™ Microbe Dispersion Counter and manual grinding method, respectively. The bacterial dispersion effect and bacterial activity were tested by microscope and colony counting method. During Jan. 2015 to June 2015, a total of 726 isolates of MTB were collected in all district tuberculosis hospitals of Shanghai. The bacterial suspension dispersed by instrument and manual grinding, were inoculated in slant medium for DST (Proportion Method), and then incubated in 37 ℃ incubator for 28 days and the DST results were reported. The effects of the 2 different bacterial dispersion methods were compared by comparing DST results and counting the bacterial colony which grew in high and low concentration control media. Paired chi-square test was used for statistical analysis, and the significance level was 0.05. Results: Compared to the manual grinding method, the MTB colony could be better dispersed by BACspreader™ Microbe Dispersion Counter, without reducing the bacterial activity. The DST results of 726 mycobacterial isolates were the same by different bacterial dispersion methods. The count of bacterial colony growing in high concentration control medium was significantly different between of the 2 dispersion methods (χ(2)=8.0, P DST results. Introducing the BACspreader™ Microbe Dispersion Counter to MTB DST could automate the DST process, make the testing results objective and standardized, and reduce personal error in the tests.

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

    Directory of Open Access Journals (Sweden)

    Isis Regina Grenier CAPOCI

    2015-12-01

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

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

    Science.gov (United States)

    Capoci, Isis Regina Grenier; Cunha, Michele Milano da; Bonfim-Mendonça, Patricia de Souza; Ghiraldi-Lopes, Luciana Dias; Baeza, Lilian Cristiane; Kioshima, Erika Seki; Svidzinski, Terezinha Inez Estivalet

    2015-12-01

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

  15. Cuticular antifungals in spiders: density- and condition dependence.

    Directory of Open Access Journals (Sweden)

    Daniel González-Tokman

    Full Text Available Animals living in groups face a high risk of disease contagion. In many arthropod species, cuticular antimicrobials constitute the first protective barrier that prevents infections. Here we report that group-living spiders produce cuticular chemicals which inhibit fungal growth. Given that cuticular antifungals may be costly to produce, we explored whether they can be modulated according to the risk of contagion (i.e. under high densities. For this purpose, we quantified cuticular antifungal activity in the subsocial crab spider Diaea ergandros in both natural nests and experimentally manipulated nests of varying density. We quantified the body-condition of spiders to test whether antifungal activity is condition dependent, as well as the effect of spider density on body-condition. We predicted cuticular antifungal activity to increase and body-condition to decrease with high spider densities, and that antifungal activity would be inversely related to body-condition. Contrary to our predictions, antifungal activity was neither density- nor condition-dependent. However, body-condition decreased with density in natural nests, but increased in experimental nests. We suggest that pathogen pressure is so important in nature that it maintains high levels of cuticular antifungal activity in spiders, impacting negatively on individual energetic condition. Future studies should identify the chemical structure of the isolated antifungal compounds in order to understand the physiological basis of a trade-off between disease prevention and energetic condition caused by group living, and its consequences in the evolution of sociality in spiders.

  16. Evaluation of MGIT 960 System for the Second-Line Drugs Susceptibility Testing of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Hyejin Kim

    2013-01-01

    Full Text Available Many laboratories validate DST of the second-line drugs by BACTEC MGIT 960 system. The objective of this study is to evaluate the critical concentration and perform DST for the 2nd line drugs. We evaluated 193 clinical strains of M. tuberculosis isolated from patients in South Korea. Testing the critical concentration of six second-line drugs was performed by MGIT 960 and compared with L-J proportion method. The critical concentration was determined to establish the most one that gave the difference between drug resistance and susceptibility in MGIT960 system. Good agreement of the following concentrations was found: Concordance was 95% for 0.5 μg/mL of moxifloxacin; 93.6%, 1.0 μg/mL of levofloxacin; 97.5%, 2.5 μg/mL of kanamycin; 90.6%, 2.5 μg/mL of capreomycin; 86.2%, 5.0 μg/mL of ethionamide; and 90.8%, 2.0 μg/mL of ρ-aminosalicylic acid. The critical concentrations of the four drugs, moxifloxacin, levofloxacin, kanamycin, and capreomycin, were concordant and reliable for testing 2nd line drug resistance. Further study of ethionamide and ρ-aminosalicylic acid is required.

  17. Spin susceptibility as a test of unitary limit in disordered graphene systems

    Science.gov (United States)

    Grosu, I.; Biter, T.-L.

    2018-03-01

    We analyzed the static spin susceptibility of graphene systems in the presence of disorder and a small energy gap. We considered the case of strong scatterers (unitary limit). The temperature and impurity concentration effects were analyzed. The critical value of the impurity concentration was calculated. The behavior of the spin susceptibility for different values of the impurity concentration is discussed.

  18. New azole derivatives showing antimicrobial effects and their mechanism of antifungal activity by molecular modeling studies.

    Science.gov (United States)

    Doğan, İnci Selin; Saraç, Selma; Sari, Suat; Kart, Didem; Eşsiz Gökhan, Şebnem; Vural, İmran; Dalkara, Sevim

    2017-04-21

    Azole antifungals are potent inhibitors of fungal lanosterol 14α demethylase (CYP51) and have been used for eradication of systemic candidiasis clinically. Herein we report the design, synthesis, and biological evaluation of a series of 1-phenyl/1-(4-chlorophenyl)-2-(1H-imidazol-1-yl)ethanol esters. Many of these derivatives showed fungal growth inhibition at very low concentrations. Minimal inhibition concentration (MIC) value of 15 was 0.125 μg/mL against Candida albicans. Additionally, some of our compounds, such as 19 (MIC: 0.25 μg/mL), were potent against resistant C. glabrata, a fungal strain less susceptible to some first-line antifungal drugs. We confirmed their antifungal efficacy by antibiofilm test and their safety against human monocytes by cytotoxicity assay. To rationalize their mechanism of action, we performed computational analysis utilizing molecular docking and dynamics simulations on the C. albicans and C. glabrata CYP51 (CACYP51 and CGCYP51) homology models we built. Leu130 and T131 emerged as possible key residues for inhibition of CGCYP51 by 19. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Novel Antifungal Compounds Discovered in Medicines for Malaria Venture's Malaria Box.

    Science.gov (United States)

    Jung, Eric H; Meyers, David J; Bosch, Jürgen; Casadevall, Arturo

    2018-01-01

    Similarities in fungal and animal cells make antifungal discovery efforts more difficult than those for other classes of antimicrobial drugs. Currently, there are only three major classes of antifungal drugs used for the treatment of systemic fungal diseases: polyenes, azoles, and echinocandins. Even in situations where the offending fungal organism is susceptible to the available drugs, treatment courses can be lengthy and unsatisfactory, since eradication of infection is often very difficult, especially in individuals with impaired immunity. Consequently, there is a need for new and more effective antifungal drugs. We have identified compounds with significant antifungal activity in the Malaria Box (Medicines for Malaria Ventures, Geneva, Switzerland) that have higher efficacy than some of the currently used antifungal drugs. Our best candidate, MMV665943 (IUPAC name 4-[6-[[2-(4-aminophenyl)-3H-benzimidazol-5-yl]methyl]-1H-benzimidazol-2-yl]aniline), here referred to as DM262, showed 16- to 32-fold-higher activity than fluconazole against Cryptococcus neoformans . There was also significant antifungal activity in other fungal species with known antifungal resistance, such as Lomentospora prolificans and Cryptococcus gattii . Antifungal activity was also observed against a common fungus, Candida albicans . These results are important because they offer a potentially new class of antifungal drugs and the repurposing of currently available therapeutics. IMPORTANCE Much like the recent increase in drug-resistant bacteria, there is a rise in antifungal-resistant strains of pathogenic fungi. There is a need for novel and more potent antifungal therapeutics. Consequently, we investigated a mixed library of drug-like and probe-like compounds with activity in Plasmodium spp. for activity against two common fungal pathogens, Cryptococcus neoformans and Candida albicans , along with two less common pathogenic species, Lomentospora prolificans and Cryptococcus gattii . We

  20. Is antifungal resistance a cause for treatment failure in dermatophytosis: A study focused on tinea corporis and cruris from a tertiary centre?

    Directory of Open Access Journals (Sweden)

    Kabir Sardana

    2018-01-01

    Full Text Available Background: Dermatophytoses are one of the most common skin diseases that have been largely simple to treat. However, in recent years, these infections have become recalcitrant to treatment which can possibly be due to antifungal resistance. Aim: To analyze the resistance pattern of patients with recalcitrant dermatophytoses. Materials and Methods: A cross-sectional evaluation was undertaken of 40 consecutive patients with recalcitrant tinea corporis/cruris/both who had taken systemic antifungal treatment and did not respond completely to therapy or had recurrent lesion within 1 month of stopping the therapy. Terbinafine, fluconazole, itraconazole, ketoconazole, amphotericin B, and voriconazole were the antifungals tested using broth microdilution assay for antifungal susceptibility testing of dermatophytes, and MIC50, 90 values were recorded. Results: KOH mount was positive in 18 (45% patients, culture was positive in 28 (70% patients. Trichophyton mentagrophytes (35% and T. rubrum (27.5% were the predominant isolates. Overall, activity of terbinafine and itraconazole were significantly higher than the other drugs tested. For terbinafine, both T. mentagrophytes and T. rubrum were inhibited at MIC90of 0.125 μg/ml. Itraconazole-inhibited T. mentagrophytes and T. rubrum at MIC90of 0.0625 and 0.25 μg/ml, respectively. All isolates had reduced susceptibility to fluconazole. Conclusion: While MIC seen were higher than western data, in-vitro resistance (>1 μg/ml to antifungals was not seen and probably may not be a cause of treatment failure. Possibly, treatment failure lies in the intricate host fungal interaction and virulence of species which help it to evade host immune response.

  1. Rapid identification and antimicrobial susceptibility testing of positive blood cultures using MALDI-TOF MS and a modification of the standardised disc diffusion test: a pilot study.

    LENUS (Irish Health Repository)

    Fitzgerald, C

    2016-04-27

    In an era when clinical microbiology laboratories are under increasing financial pressure, there is a need for inexpensive, yet effective, rapid microbiology tests. The aim of this study was to evaluate a novel modification of standard methodology for the identification and antimicrobial susceptibility testing (AST) of pathogens in positive blood cultures, reducing the turnaround time of laboratory results by 24 h.

  2. A Low Cost/Low Power Open Source Sensor System for Automated Tuberculosis Drug Susceptibility Testing

    Directory of Open Access Journals (Sweden)

    Kyukwang Kim

    2016-06-01

    Full Text Available In this research an open source, low power sensor node was developed to check the growth of mycobacteria in a culture bottle with a nitrate reductase assay method for a drug susceptibility test. The sensor system reports the temperature and color sensor output frequency change of the culture bottle when the device is triggered. After the culture process is finished, a nitrite ion detecting solution based on a commercial nitrite ion detection kit is injected into the culture bottle by a syringe pump to check bacterial growth by the formation of a pigment by the reaction between the solution and the color sensor. Sensor status and NRA results are broadcasted via a Bluetooth low energy beacon. An Android application was developed to collect the broadcasted data, classify the status of cultured samples from multiple devices, and visualize the data for the end users, circumventing the need to examine each culture bottle manually during a long culture period. The authors expect that usage of the developed sensor will decrease the cost and required labor for handling large amounts of patient samples in local health centers in developing countries. All 3D-printerable hardware parts, a circuit diagram, and software are available online.

  3. Formation of Linear Gradient of Antibiotics on Microfluidic Chips for High-throughput Antibiotic Susceptibility Testing

    Science.gov (United States)

    Kim, Seunggyu; Lee, Seokhun; Jeon, Jessie S.

    2017-11-01

    To determine the most effective antimicrobial treatments of infectious pathogen, high-throughput antibiotic susceptibility test (AST) is critically required. However, the conventional AST requires at least 16 hours to reach the minimum observable population. Therefore, we developed a microfluidic system that allows maintenance of linear antibiotic concentration and measurement of local bacterial density. Based on the Stokes-Einstein equation, the flow rate in the microchannel was optimized so that linearization was achieved within 10 minutes, taking into account the diffusion coefficient of each antibiotic in the agar gel. As a result, the minimum inhibitory concentration (MIC) of each antibiotic against P. aeruginosa could be immediately determined 6 hours after treatment of the linear antibiotic concentration. In conclusion, our system proved the efficacy of a high-throughput AST platform through MIC comparison with Clinical and Laboratory Standards Institute (CLSI) range of antibiotics. This work was supported by the Climate Change Research Hub (Grant No. N11170060) of the KAIST and by the Brain Korea 21 Plus project.

  4. A Low Cost/Low Power Open Source Sensor System for Automated Tuberculosis Drug Susceptibility Testing.

    Science.gov (United States)

    Kim, Kyukwang; Kim, Hyeong Keun; Lim, Hwijoon; Myung, Hyun

    2016-06-22

    In this research an open source, low power sensor node was developed to check the growth of mycobacteria in a culture bottle with a nitrate reductase assay method for a drug susceptibility test. The sensor system reports the temperature and color sensor output frequency change of the culture bottle when the device is triggered. After the culture process is finished, a nitrite ion detecting solution based on a commercial nitrite ion detection kit is injected into the culture bottle by a syringe pump to check bacterial growth by the formation of a pigment by the reaction between the solution and the color sensor. Sensor status and NRA results are broadcasted via a Bluetooth low energy beacon. An Android application was developed to collect the broadcasted data, classify the status of cultured samples from multiple devices, and visualize the data for the end users, circumventing the need to examine each culture bottle manually during a long culture period. The authors expect that usage of the developed sensor will decrease the cost and required labor for handling large amounts of patient samples in local health centers in developing countries. All 3D-printerable hardware parts, a circuit diagram, and software are available online.

  5. A Low Cost/Low Power Open Source Sensor System for Automated Tuberculosis Drug Susceptibility Testing

    Science.gov (United States)

    Kim, Kyukwang; Kim, Hyeong Keun; Lim, Hwijoon; Myung, Hyun

    2016-01-01

    In this research an open source, low power sensor node was developed to check the growth of mycobacteria in a culture bottle with a nitrate reductase assay method for a drug susceptibility test. The sensor system reports the temperature and color sensor output frequency change of the culture bottle when the device is triggered. After the culture process is finished, a nitrite ion detecting solution based on a commercial nitrite ion detection kit is injected into the culture bottle by a syringe pump to check bacterial growth by the formation of a pigment by the reaction between the solution and the color sensor. Sensor status and NRA results are broadcasted via a Bluetooth low energy beacon. An Android application was developed to collect the broadcasted data, classify the status of cultured samples from multiple devices, and visualize the data for the end users, circumventing the need to examine each culture bottle manually during a long culture period. The authors expect that usage of the developed sensor will decrease the cost and required labor for handling large amounts of patient samples in local health centers in developing countries. All 3D-printerable hardware parts, a circuit diagram, and software are available online. PMID:27338406

  6. Direct identification and susceptibility testing of positive blood cultures using high speed cold centrifugation and Vitek II system.

    Science.gov (United States)

    Bazzi, Ali M; Rabaan, Ali A; Fawarah, Mahmoud M; Al-Tawfiq, Jaffar A

    Compared to routine isolated colony-based methods, direct testing of bacterial pellets from positive blood cultures reduces turnaround time for reporting of antibiotic susceptibility. The aim of this study was to compare the accuracy, and precision, of a rapid method for direct identification and susceptibility testing of blood cultures with the routine method used in our laboratory, using Vitek 2. A total of 60 isolates were evaluated using the candidate and the routine method. The candidate method had 100% accuracy for the identification of Gram negative bacteria, Staphylococcus and Enterococcus, 50% for Streptococcus and 33.3% for Corynebacterium species. Susceptibility testing of Gram negative isolates yielded 98-100% essential agreement. For Staphylococcus and Enterococcus isolates, essential agreement was 100% for 17 antibiotics except for moxifloxacin. Direct testing of blood culture samples with Vitek 2 produced reliable identification and susceptibility results 18-24h sooner for aerobic/anaerobic facultative Gram-negative bacteria and Gram-positive Staphylococcus and Enterococcus strains. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  7. Experience of parental cancer in childhood is a risk factor for psychological distress during genetic cancer susceptibility testing

    NARCIS (Netherlands)

    van Oostrom, I.; Meijers-Heijboer, H.; Duivenvoorden, H. J.; Brocker-Vriends, A. H. J. T.; van Asperen, C. J.; Sijmons, R. H.; Seynaeve, C.; Van Gool, A. R.; Klijn, J. G. M.; Tibben, A.

    Background: This study explores the effect of age at the time of parental cancer diagnosis or death on psychological distress and cancer risk perception in individuals undergoing genetic testing for a specific cancer susceptibility. Patients and methods: Cancer-related distress, worry and risk

  8. Experience of parental cancer in childhood is a risk factor for psychological distress during genetic cancer susceptibility testing

    NARCIS (Netherlands)

    van Oostrom, I.; Meijers-Heijboer, H.; Duivenvoorden, H. J.; Bröcker-Vriends, A. H. J. T.; van Asperen, C. J.; Sijmons, R. H.; Seynaeve, C.; van Gool, A. R.; Klijn, J. G. M.; Tibben, A.

    2006-01-01

    This study explores the effect of age at the time of parental cancer diagnosis or death on psychological distress and cancer risk perception in individuals undergoing genetic testing for a specific cancer susceptibility. Cancer-related distress, worry and risk perception were assessed in 271

  9. Impact of Rapid Susceptibility Testing and Antibiotic Selection Strategy on the Emergence and Spread of Antibiotic Resistance in Gonorrhea.

    Science.gov (United States)

    Tuite, Ashleigh R; Gift, Thomas L; Chesson, Harrell W; Hsu, Katherine; Salomon, Joshua A; Grad, Yonatan H

    2017-11-27

    Increasing antibiotic resistance limits treatment options for gonorrhea. We examined the impact of a hypothetical point-of-care (POC) test reporting antibiotic susceptibility profiles on slowing resistance spread. A mathematical model describing gonorrhea transmission incorporated resistance emergence probabilities and fitness costs associated with resistance based on characteristics of ciprofloxacin (A), azithromycin (B), and ceftriaxone (C). We evaluated time to 1% and 5% prevalence of resistant strains among all isolates with the following: (1) empiric treatment (B and C), and treatment guided by POC tests determining susceptibility to (2) A only and (3) all 3 antibiotics. Continued empiric treatment without POC testing was projected to result in >5% of isolates being resistant to both B and C within 15 years. Use of either POC test in 10% of identified cases delayed this by 5 years. The 3 antibiotic POC test delayed the time to reach 1% prevalence of triply-resistant strains by 6 years, whereas the A-only test resulted in no delay. Results were less sensitive to assumptions about fitness costs and test characteristics with increasing test uptake. Rapid diagnostics reporting antibiotic susceptibility may extend the usefulness of existing antibiotics for gonorrhea treatment, but ongoing monitoring of resistance patterns will be critical. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  10. Performance and clinical significance of direct antimicrobial susceptibility testing on urine from hospitalized patients

    NARCIS (Netherlands)

    Breteler, K.B.; Rentenaar, R.J.; Verkaart, G.; Sturm, P.D.J.

    2011-01-01

    BACKGROUND: Urinary tract infections (UTIs) are common infections in the community and the hospital. With increasing antimicrobial resistance, specifically in the Gram-negative uropathogens, reliable, rapid antimicrobial susceptibility data would be useful to guide antimicrobial treatment. Direct

  11. Citral and carvone chemotypes from the essential oils of Colombian Lippia alba (Mill. N.E. Brown: composition, cytotoxicity and antifungal activity

    Directory of Open Access Journals (Sweden)

    Ana Cecilia Mesa-Arango

    2009-09-01

    Full Text Available Two essential oils of Lippia alba (Mill. N.E. Brown (Verbenacea, the carvone and citral chemotypes and 15 of their compounds were evaluated to determine cytotoxicity and antifungal activity. Cytotoxicity assays for both the citral and carvone chemotypes were carried out with tetrazolium-dye, which showed a dose-dependent cytotoxic effect against HeLa cells. Interestingly, this effect on the evaluated cells (HeLa and the non-tumoural cell line, Vero was lower than that of commercial citral alone. Commercial citral showed the highest cytotoxic activity on HeLa cells. The antifungal activity was evaluated against Candida parapsilosis, Candida krusei, Aspergillus flavus and Aspergillus fumigatus strains following the standard protocols, Antifungal Susceptibility Testing Subcommittee of the European Committee on Antibiotic Susceptibility Testing and CLSI M38-A. Results demonstrated that the most active essential oil was the citral chemotype, with geometric means-minimal inhibitory concentration (GM-MIC values of 78.7 and 270.8 μg/mL for A. fumigatus and C. krusei, respectively. Commercial citral showed an antifungal activity similar to that of the citral chemotype (GM-MIC values of 62.5 μg/mL for A. fumigatus and 39.7 μg/mL for C. krusei. Although the citronellal and geraniol were found in lower concentrations in the citral chemotype, they had significant antifungal activity, with GM-MIC values of 49.6 μg/mL for C. krusei and 176.8 μg/mL for A. fumigatus.

  12. Quality assurance for antimicrobial susceptibility testing of Neisseria gonorrhoeae in Latin American and Caribbean countries, 2013-2015.

    Science.gov (United States)

    Sawatzky, Pam; Martin, Irene; Galarza, Patricia; Carvallo, Marıa Elena Trigoso; Araya Rodriguez, Pamela; Cruz, Olga Marina Sanabria; Hernandez, Alina Llop; Martinez, Mario Fabian; Borthagaray, Graciela; Payares, Daisy; Moreno, José E; Chiappe, Marina; Corredor, Aura Helena; Thakur, Sidharath Dev; Dillon, Jo-Anne R

    2018-04-19

    A Neisseria gonorrhoeae antimicrobial susceptibility quality control comparison programme was re-established in Latin America and the Caribbean to ensure antimicrobial susceptibility data produced from the region are comparable nationally and internationally. Three panels, consisting of N. gonorrhoeae isolates comprising reference strains and other characterised isolates were sent to 11 participating laboratories between 2013 and 2015. Antimicrobial susceptibilities for these isolates were determined using agar dilution, Etest or disc diffusion methods. Modal minimum inhibitory concentrations (MICs) for each panel isolate/antibiotic combination were calculated. The guidelines of the Clinical and Laboratory Standards Institute were used for interpretations of antimicrobial susceptibility. The agreement of MICs with the modal MICs was determined for each of the participating laboratories as well as for each of the antibiotics tested. Five of 11 laboratories that participated in at least one panel had an overall average agreement between participants' MIC results and modal MICs of >90%. For other laboratories, agreements ranged from 60.0% to 82.4%. The proportion of agreement between interpretations for all the antibiotics, except penicillin and tetracycline, was >90%. The percentages of agreement between MIC results and their modes for erythromycin, spectinomycin, cefixime and azithromycin were >90%. Tetracycline, ceftriaxone and ciprofloxacin agreement ranged from 84.5% to 89.1%, while penicillin had 78.8% agreement between MICs and modal MICs. The participating laboratories had acceptable results, similar to other international quality assurance programmes. It is important to ensure continuation of the International Gonococcal Antimicrobial Susceptibility Quality Control Comparison Programme to ensure that participants can identify and correct any problems in antimicrobial susceptibility testing for N. gonorrhoeae as they arise and continue to generate reproducible

  13. Antibacterial and antifungal activities of andrachne cordifolia muell.

    Science.gov (United States)

    Ahmad, Bashir; Hassan Shah, S M; Bashir, Shumaila; Nisar, Muhammad; Chaudry, M Iqbal

    2007-12-01

    The crude methanolic extract of Andrachne cordifolia Muell. (Euphorbiaceae) and its various fractions in different solvent systems (chloroform, ethyl acetate and n-butanol) were screened for antibacterial and antifungal activities. Crude extract and subsequent fractions demonstrated moderate to excellent antibacterial activities against the tested pathogens. Highest antibacterial activity was displayed by both chloroform and ethyl acetate fractions (100%) followed by the crude extract (68%) against Salmonella typhi. Similarly, crude extract and its subsequent fractions showed mild to excellent activities in antifungal bioassay with maximum (76%) antifungal activity against Microsporum canis by the chloroform fraction followed by the crude extract (65%).

  14. Design, synthesis, and in vitro evaluation of novel antifungal triazoles.

    Science.gov (United States)

    Xie, Fei; Ni, Tingjunhong; Zhao, Jing; Pang, Lei; Li, Ran; Cai, Zhan; Ding, Zichao; Wang, Ting; Yu, Shichong; Jin, Yongsheng; Zhang, Dazhi; Jiang, Yuanying

    2017-05-15

    Twenty-nine novel triazole analogues of ravuconazole and isavuconazole were designed and synthesized. Most of the compounds exhibited potent in vitro antifungal activities against 8 fungal isolates. Especially, compounds a10, a13, and a14 exhibited superior or comparable antifungal activity to ravuconazole against all the tested fungi. Structure-activity relationship study indicated that replacing 4-cyanophenylthioazole moiety of ravuconazole with fluorophenylisoxazole resulted in novel antifungal triazoles with more effectiveness and a broader-spectrum. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Antifungal effect and action mechanism of antimicrobial peptide polybia-CP.

    Science.gov (United States)

    Wang, Kairong; Jia, Fengjing; Dang, Wen; Zhao, Yanyan; Zhu, Ranran; Sun, Mengyang; Qiu, Shuai; An, Xiaoping; Ma, Zelin; Zhu, Yuanyuan; Yan, Jiexi; Kong, Ziqing; Yan, Wenjin; Wang, Rui

    2016-01-01

    The incidence of life-threatening invasive fungal infections increased significantly in recent years. However, the antifungal therapeutic options are very limited. Antimicrobial peptides are a class of potential lead chemical for the development of novel antifungal agents. Antimicrobial peptide polybia-CP was purified from the venom of the social wasp Polybia paulista. In this study, we synthesized polybia-CP and determined its antifungal effects against a series of Candidian species. Our results showed that polybia-CP has potent antifungal activity and fungicidal activity against the tested fungal cells with a proposed membrane-active action mode. In addition, polybia-CP could induce the increase of cellular reactive oxygen species production, which would attribute to its antifungal activity. In conclusion, the present study suggests that polybia-CP has potential as an antifungal agent or may offer a new strategy for antifungal therapeutic option. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

  16. Liquid and vapour-phase antifungal activities of essential oils against Candida albicans and non-albicans Candida.

    Science.gov (United States)

    Mandras, Narcisa; Nostro, Antonia; Roana, Janira; Scalas, Daniela; Banche, Giuliana; Ghisetti, Valeria; Del Re, Simonetta; Fucale, Giacomo; Cuffini, Anna Maria; Tullio, Vivian

    2016-08-30

    The management of Candida infections faces many problems, such as a limited number of antifungal drugs, toxicity, resistance of Candida to commonly antifungal drugs, relapse of Candida infections, and the high cost of antifungal drugs. Though azole antifungal agents and derivatives continue to dominate as drugs of choice against Candida infections, there are many available data referring to the anticandidal activity of essential oils. Since we have previous observed a good antimicrobial activity of some essential oils against filamentous fungi, the aim of this study was to extend the research to evaluate the activity of the same oils on Candida albicans, C.glabrata and C.tropicalis clinical strains, as well as the effects of related components. Essential oils selection was based both on ethnomedicinal use and on proved antibacterial and/or antifungal activity of some of these oils. Fluconazole and voriconazole were used as reference drugs. The minimum inhibitory concentration (MIC) and the minimal fungicidal concentration (MFC) of essential oils (thyme red, fennel, clove, pine, sage, lemon balm, and lavender) and their major components were investigated by the broth microdilution method (BM) and the vapour contact assay (VC). Using BM, pine oil showed the best activity against all strains tested, though C.albicans was more susceptible than C.glabrata and C.tropicalis (MIC50-MIC90 = 0.06 %, v/v). On the contrary, sage oil displayed a weak activity (MIC50-MIC90 = 1 %, v/v). Thyme red oil (MIC50-MIC90 ≤ 0.0038 %, v/v for C.albicans and C.tropicalis, and 0.0078- Candida spp., including fluconazole/voriconazole resistant strains. These data encourage adequately controlled and randomized clinical investigations. The use in vapour phase could have additional advantages without requiring direct contact, resulting in easy of environmental application such as in hospital, and/or in school.

  17. Photographic and Luminometric Detection of Luciferase Reporter Phages for Drug Susceptibility Testing of Clinical Mycobacterium tuberculosis Isolates

    Science.gov (United States)

    Hazbón, Manzour Hernando; Guarín, Nora; Ferro, Beatriz Eugenia; Rodríguez, Ana Lucía; Labrada, Luz Angela; Tovar, Rafael; Riska, Paul F.; Jacobs, William R.

    2003-01-01

    Luciferase reporter phages (LRPs) have proven to be efficient tools for drug susceptibility testing of Mycobacterium tuberculosis. Luminometric detection of LRP activity offers higher sensitivity and quantitative results, while a Polaroid film detection method offers a “low-tech” inexpensive alternative that is called the Bronx box. In this work we evaluated, improved, and compared the performance of the luminometer and the Bronx box formats for drug susceptibility testing with LRPs by using 51 clinical isolates of M. tuberculosis, with the agar proportion method (PM) serving as reference. The sensitivity in detecting resistance to isoniazid and rifampin, antibiotics that define multidrug resistance (MDR), was 100% for both methods. The turnaround time for results was reduced from 3 weeks for PM to 54 or 94 h for luminometry or the Bronx box, respectively. These results support the utility of LRPs as a screening test for the surveillance of MDR tuberculosis. PMID:14532245

  18. Mechanisms of antifungal drug resistance in Candida dubliniensis.

    LENUS (Irish Health Repository)

    Coleman, David C

    2010-06-01

    Candida dubliniensis was first described in 1995 and is the most closely related species to the predominant human fungal pathogen Candida albicans. C. dubliniensis is significantly less prevalent and less pathogenic than C. albicans and is primarily associated with infections in HIV-infected individuals and other immunocompromised cohorts. The population structure of C. dubliniensis consists of three well-defined major clades and is significantly less diverse than C. albicans. The majority of C. dubliniensis isolates are susceptible to antifungal drugs commonly used to treat Candida infections. To date only two major patterns of antifungal drug resistance have been identified and the molecular mechanisms of these are very similar to the resistance mechanisms that have been described previously in C. albicans. However, significant differences are evident in the predominant antifungal drug mechanisms employed by C. dubliniensis, differences that reflect its more clonal nature, its lower prevalence and characteristics of its genome, the complete sequence of which has only recently been determined.

  19. [Genotyping of Vaginal Candida glabrata Isolates Using Microsatellite Marker Analysis and DNA Sequencing to Identify Mutations Associated with Antifungal Resistance].

    Science.gov (United States)

    Döğen, Aylin; Durukan, Hüseyin; Güzel, Ahmet Barış; Oksüz, Zehra; Kaplan, Engin; Serin, Mehmet Sami; Serin, Ayşe; Emekdaş, Gürol; Aslan, Gönül; Tezcan, Seda; Kalkancı, Ayşe; Ilkit, Macit

    2013-01-01

    Vulvovaginal candidosis is the second most common cause of vaginitis (17-39%) after bacterial vaginosis (22-50%). Since the diagnosis of vulvovaginal candidosis mainly depends on clinical findings without mycologic confirmatory tests and treated empirically, the actual incidence rate of vulvovaginal candidosis is unknown. Approximately 70-90% of vulvovaginal candidosis cases are caused by Candida albicans, however the increasing incidence of C.glabrata infections and its reduced susceptibility to azole drug therapy have generated increasing attention. The epidemiology and population structure of vulvovaginal candidosis due to C.glabrata are poorly characterized. This study was aimed to genotype the C.glabrata strains isolated from vaginal samples in Cukurova region, Turkey by microsatellite markers, to investigate the antifungal susceptibility profiles of the strains and to determine the molecular mechanisms leading to phenotypical azole resistance. A total of 34 unrelated vaginal C.glabrata strains isolated from patients with acute (n= 11) and recurrent (n= 14) vulvovaginal candidosis, control group (n= 9) without vaginitis symptoms, and a reference strain of C.glabrata CBS 138 (ATCC 2001) were included in the study. These isolates were genotyped using multiple-locus variable number tandem repeat analysis of three microsatellite markers (RPM2, MTI, and Cg6). Analysis of microsatellite markers was performed by fragment size determination of RPM2, MTI, and Cg6 PCR products through capillary electrophoresis. For each of the evaluated strains, DNA sequence analysis was performed for one gene (CgERG11) and four loci (CgPDR1, NTM1, TRP1, and URA3) to detect mutations possibly associated with antifungal resistance in each strain. In vitro susceptibility profiles of the strains to 13 antifungals and boric acid were determined according to CLSI document M27-A3 to investigate possible relationships between detected mutations and phenotypic resistance. C.glabrata CBS 138

  20. Effects of maternal sensitivity on low birth weight children's academic achievement: a test of differential susceptibility versus diathesis stress.

    Science.gov (United States)

    Jaekel, Julia; Pluess, Michael; Belsky, Jay; Wolke, Dieter

    2015-06-01

    Differential Susceptibility Theory (DST) postulates that some children are more affected - for better and for worse - by developmental experiences, including parenting, than others. Low birth weight (LBW, 1,500-2,499 g) may not only be a predictor for neurodevelopmental impairment but also a marker for prenatally programmed susceptibility. The aim was to test if effects of sensitive parenting on LBW and very LBW (VLBW, academic achievement are best explained by a differential susceptibility versus diathesis-stress model of person-X-environment interaction. Nine hundred and twenty-two children ranging from 600 g to 5,140 g birth weight were studied as part of a prospective, geographically defined, longitudinal investigation of neonatal at-risk children in South Germany (Bavarian Longitudinal Study). Sensitive parenting during a structured mother-child interaction task was observed and rated at age 6 years. Academic achievement was assessed with standardized mathematic, reading, and spelling/writing tests at age 8 years. Maternal sensitivity positively predicted the academic achievement of both LBW (n = 283) and VLBW (n = 202) children. Confirmatory-comparative and model-fitting analysis (testing LBW vs. NBW and VLBW vs. NBW) indicated that LBW and VLBW children were more susceptible than NBW to the adverse effects of low-sensitive, but not beneficial effects of high-sensitive parenting. Findings proved more consistent with the diathesis stress than differential-susceptibility model of person-X-environment interaction: LBW and VLBW children's exposure to positive parenting predicted catch-up to their NBW peers, whereas exposure to negative parenting predicted much poorer functioning. © 2014 Association for Child and Adolescent Mental Health.

  1. Species distribution and susceptibility profile of Candida species in a Brazilian public tertiary hospital

    Directory of Open Access Journals (Sweden)

    Montelli Augusto

    2010-01-01

    Full Text Available Abstract Background Species identification and antifungal susceptibility tests were carried out on 212 Candida isolates obtained from bloodstream infections, urinary tract infections and dialysis-associated peritonitis, from cases attended at a Brazilian public tertiary hospital from January 1998 to January 2005. Findings Candida albicans represented 33% of the isolates, Candida parapsilosis 31.1%, Candida tropicalis 17.9%,Candida glabrata 11.8%, and others species 6.2%. In blood culture, C. parapsilosis was the most frequently encountered species (48%. The resistance levels to the antifungal azoles were relatively low for the several species, except for C. tropicalis and C. glabrata. Amphotericin B resistance was observed in 1 isolate of C. parapsilosis. Conclusions The species distribution and antifungal susceptibility herein observed presented several epidemiological features common to other tertiary hospitals in Latin American countries. It also exhibited some peculiarity, such as a very high frequency of C. parapsilosis both in bloodstream infections and dialysis-associated peritonitis. C. albicans also occurred in an important number of case infections, in all evaluated clinical sources. C. glabrata presented a high proportion of resistant isolates. The data emphasize the necessity to carry out the correct species identification accompanied by the susceptibility tests in all tertiary hospitals.

  2. Typhoid outbreak in Songkhla, Thailand 2009-2011: clinical outcomes, susceptibility patterns, and reliability of serology tests.

    Directory of Open Access Journals (Sweden)

    Wannee Limpitikul

    Full Text Available OBJECTIVE: To determine the clinical manifestations and outcomes, the reliability of Salmonella enterica serotype Typhi (S ser. Typhi IgM and IgG rapid tests, and the susceptibility patterns and the response to treatment during the 2009-2011 typhoid outbreak in Songkhla province in Thailand. METHOD: The medical records of children aged <15 years with S ser. Typhi bacteremia were analysed. The efficacy of the typhoid IgM and IgG rapid tests and susceptibility of the S ser. Typhi to the current main antibiotics used for typhoid (amoxicillin, ampicillin, cefotaxime, ceftriaxone, co-trimoxazole, and ciprofloxacin, were evaluated. RESULTS: S ser. Typhi bacteremia was found in 368 patients, and all isolated strains were susceptible to all 6 antimicrobials tested. Most of the patients were treated with ciprofloxacin for 7-14 days. The median time (IQR of fever before treatment and duration of fever after treatment were 5 (4, 7 days and 4 (3, 5 days, respectively. Complications of ascites, lower respiratory symptoms, anemia (Hct <30%, and ileal perforation were found in 7, 7, 22, and 1 patients, respectively. None of the patients had recurrent infection or died. The sensitivities of the typhoid IgM and IgG tests were 58.3% and 25.6% respectively, and specificities were 74.1% and 50.5%, respectively. CONCLUSION: Most of the patients were diagnosed at an early stage and treated with a good outcome. All S ser. Typhi strains were susceptible to standard first line antibiotic typhoid treatment. The typhoid IgM and IgG rapid tests had low sensitivity and moderate specificity.

  3. Standard Test Methods for Detecting Susceptibility to Intergranular Corrosion in Wrought, Nickel-Rich, Chromium-Bearing Alloys

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 These test methods cover two tests as follows: 1.1.1 Method A, Ferric Sulfate-Sulfuric Acid Test (Sections 3-10, inclusive)—This test method describes the procedure for conducting the boiling ferric sulfate—50 % sulfuric acid test which measures the susceptibility of certain nickel-rich, chromium-bearing alloys to intergranular corrosion (see Terminology G 15), which may be encountered in certain service environments. The uniform corrosion rate obtained by this test method, which is a function of minor variations in alloy composition, may easily mask the intergranular corrosion components of the overall corrosion rate on alloys N10276, N06022, N06059, and N06455. 1.1.2 Method B, Mixed Acid-Oxidizing Salt Test (Sections 11-18, inclusive)—This test method describes the procedure for conducting a boiling 23 % sulfuric + 1.2 % hydrochloric + 1 % ferric chloride + 1 % cupric chloride test which measures the susceptibility of certain nickel-rich, chromium-bearing alloys to display a step function increa...

  4. [Amides of amino acids and peptides as antifungal agents].

    Science.gov (United States)

    Giori, P; Vertuani, G; Mazzotta, D; Guarneri, M; Pancaldi, D; Brunelli, A

    1982-07-01

    The synthesis of pyrazolyl-amides of aminoacids and peptides is described. The chemicals were tested for antifungal activity against wheat powdery mildew (Erysiphe graminis DC.), cucumber powdery mildew (Erysiphe cichoracearum DC.), wheat brown rust (Puccinia recondita Rob. ex Desm. f. sp. tritici Erikss et Henn.), celery leaf spot (Septoria Apii Briosi ed Cav. Chest.) and collar rot (Rhizoctonia solani Kuhn). Some of these compounds showed antifungal activity.

  5. The Emerging Pathogen Candida auris: Growth Phenotype, Virulence Factors, Activity of Antifungals, and Effect of SCY-078, a Novel Glucan Synthesis Inhibitor, on Growth Morphology and Biofilm Formation.

    Science.gov (United States)

    Larkin, Emily; Hager, Christopher; Chandra, Jyotsna; Mukherjee, Pranab K; Retuerto, Mauricio; Salem, Iman; Long, Lisa; Isham, Nancy; Kovanda, Laura; Borroto-Esoda, Katyna; Wring, Steve; Angulo, David; Ghannoum, Mahmoud

    2017-05-01

    Candida auris , a new multidrug-resistant Candida spp. which is associated with invasive infection and high rates of mortality, has recently emerged. Here, we determined the virulence factors (germination, adherence, biofilm formation, phospholipase and proteinase production) of 16 C. auris isolates and their susceptibilities to 11 drugs belonging to different antifungal classes, including a novel orally bioavailable 1,3-β-d-glucan synthesis inhibitor (SCY-078). We also examined the effect of SCY-078 on the growth, ultrastructure, and biofilm-forming abilities of C. auris Our data showed that while the tested strains did not germinate, they did produce phospholipase and proteinase in a strain-dependent manner and had a significantly reduced ability to adhere and form biofilms compared to that of Candida albicans ( P = 0.01). C. auris isolates demonstrated reduced susceptibility to fluconazole and amphotericin B, while, in general, they were susceptible to the remaining drugs tested. SCY-078 had an MIC 90 of 1 mg/liter against C. auris and caused complete inhibition of the growth of C. auris and C. albicans Scanning electron microscopy analysis showed that SCY-078 interrupted C. auris cell division, with the organism forming abnormal fused fungal cells. Additionally, SCY-078 possessed potent antibiofilm activity, wherein treated biofilms demonstrated significantly reduced metabolic activity and a significantly reduced thickness compared to the untreated control ( P < 0.05 for both comparisons). Our study shows that C. auris expresses several virulence determinants (albeit to a lesser extent than C. albicans ) and is resistant to fluconazole and amphotericin B. SCY-078, the new orally bioavailable antifungal, had potent antifungal/antibiofilm activity against C. auris , indicating that further evaluation of this antifungal is warranted. Copyright © 2017 Larkin et al.

  6. Susceptibility Testing of Malassezia Species Using the Urea Broth Microdilution Method

    Science.gov (United States)

    Nakamura, Yuka; Kano, Rui; Murai, Tae; Watanabe, Shinichi; Hasegawa, Atsuhiko

    2000-01-01

    A urea broth microdilution method to assay the susceptibilities of seven Malassezia species was developed. This method indicated the same sensitivities as the agar plate dilution method for isolates of Malassezia furfur, M. pachydermatis, M. slooffiae, and M. sympodialis. PMID:10898698

  7. Susceptibility and diversity in the therapy-refractory genus scedosporium

    NARCIS (Netherlands)

    Lackner, M.; Hagen, F.; Meis, J.F.G.M.; Gerrits-van den Ende, A.H.; Vu, D.; Robert, V.; Fritz, J.; Moussa, T.A.; Hoog, G.S. de

    2014-01-01

    Scedosporium species show decreased susceptibility to the majority of systemic antifungal drugs. Acquired resistance is likely to disseminate differentially with the mode of exchange of genetic material between lineages. Inter- and intraspecific diversities of Scedosporium species were analyzed for

  8. Susceptibility and Diversity in the Therapy-Refractory Genus Scedosporium

    NARCIS (Netherlands)

    Lackner, M; Hagen, F; Meis, JF; Gerrits van den Ende, Bert; Vu, D; Robert, V; Fritz, J; Moussa, TAA; de Hoog, GS

    2014-01-01

    Scedosporium species show decreased susceptibility to the majority of systemic antifungal drugs. Acquired resistance is likely to disseminate differentially with the mode of exchange of genetic material between lineages. Inter- and intraspecific diversities of Scedosporium species were analyzed for

  9. Drug susceptibility testing in microaerophilic parasites: Cysteine strongly affects the effectivities of metronidazole and auranofin, a novel and promising antimicrobial

    Directory of Open Access Journals (Sweden)

    David Leitsch

    2017-12-01

    Full Text Available The microaerophilic parasites Entamoeba histolytica, Trichomonas vaginalis, and Giardia lamblia annually cause hundreds of millions of human infections which are treated with antiparasitic drugs. Metronidazole is the most often prescribed drug but also other drugs are in use, and novel drugs with improved characteristics are constantly being developed. One of these novel drugs is auranofin, originally an antirheumatic which has been relabelled for the treatment of parasitic infections. Drug effectivity is arguably the most important criterion for its applicability and is commonly assessed in susceptibility assays using in vitro cultures of a given pathogen. However, drug susceptibility assays can be strongly affected by certain compounds in the growth media. In the case of microaerophilic parasites, cysteine which is added in large amounts as an antioxidant is an obvious candidate because it is highly reactive and known to modulate the toxicity of metronidazole in several microaerophilic parasites.In this study, it was attempted to reduce cysteine concentrations as far as possible without affecting parasite viability by performing drug susceptibility assays under strictly anaerobic conditions in an anaerobic cabinet. Indeed, T. vaginalis and E. histolytica could be grown without any cysteine added and the cysteine concentration necessary to maintain G. lamblia could be reduced to 20%. Susceptibilities to metronidazole were found to be clearly reduced in the presence of cysteine. With auranofin the protective effect of cysteine was extreme, providing protection to concentrations up to 100-fold higher as observed in the absence of cysteine. With three other drugs tested, albendazole, furazolidone and nitazoxanide, all in use against G. lamblia, the effect of cysteine was less pronounced. Oxygen was found to have a less marked impact on metronidazole and auranofin than cysteine but bovine bile which is standardly used in growth media for G

  10. Dynamics of Mixed- Candida Species Biofilms in Response to Antifungals.

    Science.gov (United States)

    Vipulanandan, G; Herrera, M; Wiederhold, N P; Li, X; Mintz, J; Wickes, B L; Kadosh, D

    2018-01-01

    Oral infections caused by Candida species, the most commonly isolated human fungal pathogen, are frequently associated with biofilms. Although Candida albicans is the predominant organism found in patients with oral thrush, a biofilm infection, there is an increasing incidence of oral colonization and infections caused by non- albicans Candida species, including C. glabrata, C. dubliniensis, and C. tropicalis, which are frequently more resistant to antifungal treatment. While single-species Candida biofilms have been well studied, considerably less is known about the dynamics of mixed- Candida species biofilms and how these dynamics are altered by antifungal treatment. To address these questions, we developed a quantitative polymerase chain reaction-based approach to determine the precise species composition of mixed- Candida species biofilms formed by clinical isolates and laboratory strains in the presence and absence of clinically relevant concentrations of 3 commonly used antifungals: fluconazole, caspofungin, and amphotericin B. In monospecies biofilms, fluconazole exposure favored growth of C. glabrata and C. tropicalis, while caspofungin generally favored significant growth of all species to a varying degree. Fluconazole was not effective against preformed mixed- Candida species biofilms while amphotericin B was potent. As a general trend, in mixed- Candida species biofilms, C. albicans lost dominance in the presence of antifungals. Interestingly, presence in mixed versus monospecies biofilms reduced susceptibility to amphotericin B for C. tropicalis and C. glabrata. Overall, our data suggest that antifungal treatment favors the growth of specific non- albicans Candida species in mixed- Candida species biofilms.

  11. Antifungal therapy in European hospitals

    DEFF Research Database (Denmark)

    Zarb, P; Amadeo, B; Muller, A

    2012-01-01

    The study aimed to identify targets for quality improvement in antifungal use in European hospitals and determine the variability of such prescribing. Hospitals that participated in the European Surveillance of Antimicrobial Consumption Point Prevalence Surveys (ESAC-PPS) were included. The WHO...... of 40,878 (3.7%) antimicrobials. Antifungals were mainly (54.2%) administered orally. Hospital-acquired infections represented 44.5% of indications for antifungals followed by medical prophylaxis at 31.2%. The site of infection was not defined in 36.0% of cases but the most commonly targeted sites were...... respiratory (19.2%) and gastrointestinal (18.8%). The most used antifungal was fluconazole (60.5%) followed by caspofungin (10.5%). Antifungal-antibacterial combinations were frequently used (77.5%). The predominance of fluconazole use in participating hospitals could result in an increase in prevalence...

  12. Quality-control ranges for antimicrobial susceptibility testing by broth dilution of the Brachyspira hyodysenteriae type strain (ATCC 27164(T))

    DEFF Research Database (Denmark)

    Pringle, M.; Aarestrup, Frank Møller; Bergsjø, B.

    2006-01-01

    There are no approved standards for antimicrobial susceptibility testing of the fastidious spirochete Brachyspira hyodysenteriae. An interlaboratory study was performed to establish MIC quality control ranges for six antimicrobial agents for the type strain of B. hyodysenteriae using broth diluti....... The results showed that B. hyodysenteriae B78(T) ATCC 27164(T) is a suitable quality control strain. This is a first step toward standardization of methods regarding this anaerobe....

  13. Molecular and Growth-Based Drug Susceptibility Testing of Mycobacterium tuberculosis Complex for Ethambutol Resistance in the United States

    Directory of Open Access Journals (Sweden)

    Mitchell A. Yakrus

    2016-01-01

    Full Text Available Ethambutol (EMB is used as a part of drug regimens for treatment of tuberculosis (TB. Susceptibility of Mycobacterium tuberculosis complex (MTBC isolates to EMB can be discerned by DNA sequencing to detect mutations in the embB gene associated with resistance. US Public Health Laboratories (PHL primarily use growth-based drug susceptibility test (DST methods to determine EMB resistance. The Centers for Disease Control and Prevention (CDC provides a service for molecular detection of drug resistance (MDDR by DNA sequencing and concurrent growth-based DST using agar proportion. PHL and CDC test results were compared for 211 MTBC samples submitted to CDC from September 2009 through February 2011. Concordance between growth-based DST results from PHL and CDC was 88.2%. A growth-based comparison of 39 samples, where an embB mutation associated with EMB resistance was detected, revealed a higher percentage of EMB resistance by CDC (84.6% than by PHL (59.0% which was significant (P value = 0.002. Discordance between all growth-based test results from PHL and CDC was also significant (P value = 0.003. Most discordance was linked to false susceptibility using the BACTEC™ MGIT™ 960 (MGIT growth-based system. Our analysis supports coalescing growth-based and molecular results for an informed interpretation of potential EMB resistance.

  14. Task 2 - Limits for High-Frequency Conducted Susceptibility Testing - CS114 (NRC-HQ-60-14-D-0015)

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Richard Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ewing, Paul D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moses, Rebecca J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    A principal focus of Task 2 under this project was for ORNL to evaluate the basis for susceptibility testing against high-frequency conducted interference and to establish recommendations to resolve concerns about the severity of test limits for the conducted susceptibility (CS) test, CS114, from MIL-STD-461. The primary concern about the test limit has been characterized by the EPRI EMI Working Group in the following terms: Demonstrating compliance with the CS114 test limits recommended in TR-102323 has proven to be problematic, even for components that have been tested to commercial standards and demonstrated proper operation in industrial applications [6]. Specifically, EPRI notes that the CS114 limits approved in regulatory documents are significantly higher than those invoked by the US military and similar commercial standards in the frequency range below 200 kHz. For this task, ORNL evaluated the original approach to establishing the test limit, EPRI technical findings from a review of the limit, and the regulatory basis through which the currently approved limits were accepted. Based on this analysis, strategies have been developed regarding changes to the CS114 limit that can resolve the technical concerns raised by the industry. Guided by the principles that reasonable assurance of safety must not be compromised but excessive conservatism should be reduced, recommendations on a suitable basis for a revised limit have been developed and can be incorporated into the planned Revision 2 of RG 1.180.

  15. Synthesis and testing of 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazole derivatives for antifungal activity against selected Candida Species

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Cledualdo S. de; Lira, Bruno F.; Athayde-Filho, Petronio F. de, E-mail: athayde-filho@quimica.ufpb.br [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Quimica; Barbosa-Filho, Jose M.; Lorenzo, Jorge G.F.; Menezes, Camilla P. de; Santos, Jessyca M.C.G. dos; Lima, Edeltrudes de O. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Ciencias Farmaceuticas

    2013-01-15

    A series of 21 1,3,4-oxadiazoline derivatives was synthesized by cyclization of N-acylhydrazones with acetic anhydride and evaluated for their in vitro antifungal activity against six Candida strains: Candida albicans (ATCC 90028 and LM V-42), C. krusei (ATCC 6258 and LM 12 C) and C. tropicalis (ATCC 13803 and LM 14). The Candida strains were found to be sensitive to some of the compounds, which inhibited the growth by 50-90%, with minimum inhibitory concentration (MIC) in the range of 64-512 {mu}g mL{sup -1}. The compounds' structures were fully confirmed and characterized by Fourier transform infrared spectroscopy (FTIR), {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR) and mass spectrometry (MS). (author)

  16. Isolation, cultivation, and in vitro susceptibility testing of Borrelia burgdorferi sensu lato: A review

    Directory of Open Access Journals (Sweden)

    Veinović Gorana

    2013-01-01

    Full Text Available Lyme borreliosis is the most common vector-borne disease in the northern hemisphere. The agents of Lyme borreliosis are borrelia, bacteria of the family Spirochaetaceae, which are grouped in Borrelia burgdorferi sensu lato species complex. Borreliae are fastidious, slow-growing and biochemically inactive bacteria that need special attention and optimal conditions for cultivation. The isolation of Borrelia from clinical material and their cultivation is a time-consuming and demanding procedure. Cultivation lasts from 9 up to 12 weeks, which is much longer than is necessary to grow most other human bacterial pathogens. Although B. burgdorferi sensu lato is susceptible to a wide range of antimicrobial agents in vitro, up to now the susceptibility of individual Borrelia species to antibiotics is defined only partially. [Projekat Ministarstva nauke Republike Srbije, br. 175011

  17. Evaluation of Veterinary-Specific Interpretive Criteria for Susceptibility Testing of Streptococcus equi Subspecies with Trimethoprim-Sulfamethoxazole and Trimethoprim-Sulfadiazine

    DEFF Research Database (Denmark)

    Sadaka, Carmen; Kanellos, Theo; Guardabassi, Luca

    2017-01-01

    Antimicrobial susceptibility test results for trimethoprim-sulfadiazine with Streptococcus equi subspecies are interpreted based on human data for trimethoprim-sulfamethoxazole. The veterinary-specific data generated in this study support a single breakpoint for testing trimethoprim-sulfamethoxaz......Antimicrobial susceptibility test results for trimethoprim-sulfadiazine with Streptococcus equi subspecies are interpreted based on human data for trimethoprim-sulfamethoxazole. The veterinary-specific data generated in this study support a single breakpoint for testing trimethoprim...

  18. Antimicrobial susceptibility testing before first-line treatment for Helicobacter pylori infection in patients with dual or triple antibiotic resistance.

    Science.gov (United States)

    Cosme, Angel; Montes, Milagrosa; Ibarra, Begoña; Tamayo, Esther; Alonso, Horacio; Mendarte, Usua; Lizasoan, Jacobo; Herreros-Villanueva, Marta; Bujanda, Luis

    2017-05-14

    To evaluate the efficacy of antimicrobial susceptibility-guided therapy before first-line treatment for infection in patients with dual or triple antibiotic resistance. A total of 1034 patients infected by Helicobacter pylori ( H. pylori ) during 2013-2014 were tested for antimicrobial susceptibility. 157 of 1034 (15%) patients showed resistance to two (127/1034; 12%) and to three (30/1034; 3%) antibiotics. Sixty-eight patients with dual H. pylori -resistance (clarithromycin, metronidazole or levofloxacin) were treated for 10 d with triple therapies: OAL (omeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and levofloxacin 500 mg b.i.d.) 43 cases, OAM (omeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and metronidazole 500 mg b.i.d.) 12 cases and OAC (omeprazole 20 mg b.id., amoxicillin 1 g b.i.d., and clarithromycin 500 mg b.i.d.) 13 cases based on the antimicrobial susceptibility testing. Twelve patients showed triple H. pylori -resistance (clarithromycin, metronidazole and levofloxacin) and received for 10 d triple therapy with OAR (omeprazole 20 mg b.id., amoxicillin 1 g b.i.d., and rifabutin 150 mg b.i.d.). Eradication was confirmed by 13C-urea breath test. Adverse effects and compliance were assessed by a questionnaire. Intention-to-treat eradication rates were: OAL (97.6%), OAM (91.6%), OAC (92.3%) and OAR (58.3%). Cure rate was significantly higher in naïve patients treated with OAR-10 compared to patients who had two or three previous treatment failures (83% vs 33%). Adverse events rates for OAL, OAM, OAC and OAR were 22%, 25%, 23% and 17%, respectively, all of them mild-moderate. Antimicrobial susceptibility-guided triple therapies during 10 d for first-line treatment leads to an eradication rate superior to 90% in patients with dual antibiotic H. pylori resistance.

  19. Standard practice for slow strain rate testing to evaluate the susceptibility of metallic materials to environmentally assisted cracking

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This practice covers procedures for the design, preparation, and use of axially loaded, tension test specimens and fatigue pre-cracked (fracture mechanics) specimens for use in slow strain rate (SSR) tests to investigate the resistance of metallic materials to environmentally assisted cracking (EAC). While some investigators utilize SSR test techniques in combination with cyclic or fatigue loading, no attempt has been made to incorporate such techniques into this practice. 1.2 Slow strain rate testing is applicable to the evaluation of a wide variety of metallic materials in test environments which simulate aqueous, nonaqueous, and gaseous service environments over a wide range of temperatures and pressures that may cause EAC of susceptible materials. 1.3 The primary use of this practice is to furnish accepted procedures for the accelerated testing of the resistance of metallic materials to EAC under various environmental conditions. In many cases, the initiation of EAC is accelerated through the applic...

  20. Antifungal activity of cinnamaldehyde and eugenol congeners against wood-rot fungi.

    Science.gov (United States)

    Cheng, Sen-Sung; Liu, Ju-Yun; Chang, Ed-Haun; Chang, Shang-Tzen

    2008-07-01

    In this study, the antifungal activities of cinnamaldehyde and eugenol congeners against white-rot fungus Lenzites betulina and brown-rot fungus Laetiporus sulphureus were evaluated and the relationships between the antifungal activity and the chemical structures were also examined. Results from antifungal tests revealed that cinnamaldehyde, alpha-methyl cinnamaldehyde, (E)-2-methylcinnamic acid, eugenol and isoeugenol exhibited strong antifungal activity against all fungi tested. Results derived from the chemical structure-antifungal activity relationship study suggested that compounds with an aldehyde group or an acid group, a conjugated double bond and a length of CH chain outside the ring affect their antifungal properties. Furthermore, the presence of the methyl moiety in the ortho position may have a considerable influence on the inhibitory action against L. betulina and L. sulphureus. In addition, the lipophilicity may play, in part, a crucial role in determining the toxicity of phenylpropenes.

  1. Comparison of Disk Diffusion and E-Test Methods for Doripenem Susceptibility of Nosocomial Acinetobacter Baumannii Strains

    Directory of Open Access Journals (Sweden)

    Yesim Cekin

    2014-03-01

    Full Text Available Aim: Acinetobacter species are amoung the most common two cause of infections isolated from patients of intensive care unit in our hospital. Doripenem which acts by inhibiting cell wall synthesis is resently introduced for use in our country is broad spectrum antibiotic belonging to carbapenems. There are many studies investigating the susceptibility of doripenem of Acinetobacter baumannii which is isolated as a cause of ventilatory associated pneumonia in the literature. We aimed to compare e-test and disc diffusion methods for doripenem susceptibility of acinetobacter baumannii strains as nosocomial infections Acinetobacter baumanni isolates detected as nosocomial infection. Material and Method:. Between January to December, 2009 a total of 94 Acinetobacter baumanni strains isolated from different clinical specimens from intensive care units have been studied for doripenem susceptibility by disc diffusion and E-test methods. Minimal inhibitory consantrations (MIC were accepted as; sensitive %u22641 %u03BCg/ml, intermadiate 2-4 %u03BCg/ml, resistant >4 %u03BCg/ml and diameters of inhibition zone with 10 µg disc; sensitive

  2. Study of Candida Bloodstream Infections in Surgical Intensive Care Unit Patients and Susceptibility Profile of the Isolates

    Directory of Open Access Journals (Sweden)

    Vijaya S. Rajmane

    2015-01-01

    Full Text Available Background: The increased incidence of fungal infections in the past two decades has been overwhelming. Despite the fact that invasive fungal infections are still under-diagnosed and underreported, bloodstream infection due to Candida is now being recognized as an important public health problem especially in ICU patients with considerable morbidity, mortality and health care costs. Objective: To study the incidence, risk factors and antifungal susceptibility of Candida bloodstream infection in our hospital. Material and Methods: In the present study, the blood samples were collected from patients admitted in Surgical ICU. Samples were processed and antifungal susceptibility of the isolates was performed using standard protocol. Results: Out of total 93 patients, 14 (15.05% were positive for candidemia with equal distribution of both C. albicans and nonalbicans Candida spp. The risk factors associated with candidemia showing statistical significance were length of ICU stay > 7 days, mechanical ventilation, central venous catheters and uncontrolled diabetes. Among the patients with candidemia the mortality rate was 78.57 %. Resistance to Amphotericin B was seen in 33.33 % isolates of C. tropicalis and 100 % isolates of C. rugosa. 33.33 % of C. tropicalis and 50 % of C. rugosa showed dose dependent susceptibility to Fluconazole. Conclusion: Early diagnosis and antifungal susceptibility testing is very important in the treatment of candidemia for reducing the mortality rate.

  3. Candidemia epidemiology and susceptibility profile in the largest Brazilian teaching hospital complex

    Directory of Open Access Journals (Sweden)

    Adriana Lopes Motta

    Full Text Available INTRODUCTION: Although the spectrum of fungi causing bloodstream fungal infections continues to expand, Candida spp. remains responsible for the majority of these cases. OBJECTIVE: The purpose of this study was to characterize the candidemia epidemiology, species distribution and antifungal susceptibility patterns at a Brazilian tertiary teaching public hospital with 2,500 beds. METHODS: Records from the microbiology laboratory were used to identify patients with positive blood cultures during 2006. The in vitro activity of amphotericin B, caspofungin, itraconazole, fluconazole, voricanozole, and posaconazole were determined using the Etest method. RESULTS: One hundred and thirty-six cases of candidemia were identified and 100 strains were available for antifungal susceptibility testing. The overall incidence of candidemia was 1.87 cases/1.000 admissions and 0.27 cases/1.000 patient-days. Among the patients, 58.1% were male, and the median age was 40 years old. C. albicans was the most common species (52.2%, followed by C. parapsilosis (22.1%, C. tropicalis (14.8%, and C. glabrata (6.6%. All strains were susceptible to amphotericin B with a MIC90 of 0.5 µg/mL. Overall susceptibility for voriconozole, fluconazole, and caspofungin was > 97% with a MIC90 of 0.064, 4.0 and 1.0 µg/mL, respectively. For itraconazole the susceptibility rate was 81% with a MIC90 of 0.5 µg/mL. Posaconazole also demonstrated good in vitro activity with a MIC90 of 0.25 µg/mL. CONCLUSION: This is the first antifungal susceptibility report in our institution

  4. Comparison of disc diffusion, Etest and broth microdilution for testing susceptibility of carbapenem-resistant P. aeruginosa to polymyxins

    Directory of Open Access Journals (Sweden)

    Fung Liang

    2007-08-01

    Full Text Available Abstract Background Considering the increasing use of polymyxins to treat infections due to multidrug resistant Gram-negative in many countries, it is important to evaluate different susceptibility testing methods to this class of antibiotic. Methods Susceptibility of 109 carbapenem-resistant P. aeruginosa to polymyxins was tested comparing broth microdilution (reference method, disc diffusion, and Etest using the new interpretative breakpoints of Clinical and Laboratory Standards Institute. Results Twenty-nine percent of isolates belonged to endemic clone and thus, these strains were excluded of analysis. Among 78 strains evaluated, only one isolate was resistant to polymyxin B by the reference method (MIC: 8.0 μg/mL. Very major and major error rates of 1.2% and 11.5% were detected comparing polymyxin B disc diffusion with the broth microdilution (reference method. Agreement within 1 twofold dilution between Etest and the broth microdilution were 33% for polymyxin B and 79.5% for colistin. One major error and 48.7% minor errors were found comparing polymyxin B Etest with broth microdilution and only 6.4% minor errors with colistin. The concordance between Etest and the broth microdilution (reference method was respectively 100% for colistin and 90% for polymyxin B. Conclusion Resistance to polymyxins seems to be rare among hospital carbapenem-resistant P. aeruginosa isolates over a six-year period. Our results showed, using the new CLSI criteria, that the disc diffusion susceptibility does not report major errors (false-resistant results for colistin. On the other hand, showed a high frequency of minor errors and 1 very major error for polymyxin B. Etest presented better results for colistin than polymyxin B. Until these results are reproduced with a large number of polymyxins-resistant P. aeruginosa isolates, susceptibility to polymyxins should be confirmed by a reference method.

  5. [Drug susceptibility test guided therapy and novel empirical quadruple therapy for Helicobacter pylori infection: a network Meta-analysis].

    Science.gov (United States)

    Gou, Q Y; Yu, R B; Shi, R H

    2017-05-10

    Objective: To compare the efficacy and the risk of adverse effect of drug susceptibility test guided therapy and novel empirical quadruple therapy for Helicobacter ( H .) pylori infection. Methods: Literature retrieval was conducted by using major databases. Related papers published up to June 2015 were considered eligible if they were randomized control trials comparing different pharmacological formulations for H. pylori infection and used in a network Meta-analysis and a single rate Meta-analysis to evaluate the relative and absolute rates of H. pylori eradication and the risk of adverse effect. The Jadad score was used to evaluate the methodological quality. Funnel plot was constructed to evaluate the risk of publication bias. Begg's rank correlation test or Egger's regression intercept test was done for the asymmetry of funnel plot. Results: Twenty randomized control trials for the treatment of 6 753 initial treated patients with H. pylori infection were included. Drug susceptibility test guided therapy was significantly superior to concomitant therapy, hybrid therapy, sequential therapy and bismuth quadruple therapy. The culture-based therapy had the highest likelihood of improving clinical efficacy, with lowest risk of adverse effect. Concomitant therapy had the highest probability of causing adverse effect despite its effectiveness. Hybrid therapy and bismuth quadruple therapy were associated with lower risk of adverse effect and higher effectiveness. Conclusion: Drug susceptibility test guided therapy showed superiority to other 4 interventions for H. pylori eradication mentioned above. Hybrid therapy and bismuth quadruple therapy might be applied in the settings where the culture-based strategy is not available.

  6. Comparison of direct antimicrobial susceptibility testing methods for rapid analysis of bronchial secretion samples in ventilator-associated pneumonia.

    Science.gov (United States)

    Kontopidou, Flora; Galani, Irene; Panagea, Theofano; Antoniadou, Anastasia; Souli, Maria; Paramythiotou, Elisabeth; Koukos, George; Karadani, Irene; Armaganidis, Apostolos; Giamarellou, Helen

    2011-08-01

    Two hundred and fifty tracheal aspirates were subjected to direct antimicrobial susceptibility testing by disk diffusion, Etest and inoculation on antibiotic-enriched MacConkey agar plates. Results were compared with those obtained using an automated system on microorganisms recovered from standard quantitative culture. A total of 255 microorganisms were isolated from 194 positive samples by the standard quantitative procedure. A total of 85.1%, 82.5% and 72.5% agreement between direct disk diffusion, Etest and antibiotic-enriched MacConkey agar plates, respectively, and the standard procedure was observed in 64 microorganisms obtained from monomicrobial cultures that corresponded to 240 individual microorganism-antimicrobial agent combinations. Three (1.3%) and four (1.7%) very major errors for direct disk diffusion and Etest methods were observed, respectively. The antibiotic-enriched MacConkey agar plate method compared with the standard procedure demonstrated an unacceptable rate of very major (6.7%) and major errors (14.2%). Clinical evaluation of direct susceptibility tests based on the speculative impact on clinical practice by guiding patient's early treatment, if all positive cultures corresponded to infection, was correct in 79.9% for the direct disk diffusion test, 77.8% for the direct Etest method and 68.0% for antibiotic-enriched MacConkey agar plates. Direct diffusion tests (Etest or disk diffusion) applied on respiratory samples are rapid techniques that provide results comparable with standard antimicrobial susceptibility testing in <24 h. Copyright © 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  7. Evaluation of an Automated System for Reading and Interpreting Disk Diffusion Antimicrobial Susceptibility Testing of Fastidious Bacteria.

    Directory of Open Access Journals (Sweden)

    Evgeny A Idelevich

    Full Text Available Results of disk diffusion antimicrobial susceptibility testing depend on individual visual reading of inhibition zone diameters. Therefore, automated reading using camera systems might represent a useful tool for standardization. In this study, the ADAGIO automated system (Bio-Rad was evaluated for reading disk diffusion tests of fastidious bacteria. 144 clinical isolates (68 β-haemolytic streptococci, 28 Streptococcus pneumoniae, 18 viridans group streptococci, 13 Haemophilus influenzae, 7 Moraxella catarrhalis, and 10 Campylobacter jejuni were tested on Mueller-Hinton agar supplemented with 5% defibrinated horse blood and 20 mg/L β-NAD (MH-F, Oxoid according to EUCAST. Plates were read manually with a ruler and automatically using the ADAGIO system. Inhibition zone diameters, indicated by the automated system, were visually controlled and adjusted, if necessary. Among 1548 isolate-antibiotic combinations, comparison of automated vs. manual reading yielded categorical agreement (CA without visual adjustment of the automatically determined zone diameters in 81.4%. In 20% (309 of 1548 of tests it was deemed necessary to adjust the automatically determined zone diameter after visual control. After adjustment, CA was 94.8%; very major errors (false susceptible interpretation, major errors (false resistant interpretation and minor errors (false categorization involving intermediate result, calculated according to the ISO 20776-2 guideline, accounted to 13.7% (13 of 95 resistant results, 3.3% (47 of 1424 susceptible results and 1.4% (21 of 1548 total results, respectively, compared to manual reading. The ADAGIO system allowed for automated reading of disk diffusion testing in fastidious bacteria and, after visual validation of the automated results, yielded good categorical agreement with manual reading.

  8. Antifungal activity of 10 Guadeloupean plants.

    Science.gov (United States)

    Biabiany, Murielle; Roumy, Vincent; Hennebelle, Thierry; François, Nadine; Sendid, Boualem; Pottier, Muriel; Aliouat, El Moukhtar; Rouaud, Isabelle; Lohézic-Le Dévéhat, Françoise; Joseph, Henry; Bourgeois, Paul; Sahpaz, Sevser; Bailleul, François

    2013-11-01

    Screening of the antifungal activities of ten Guadeloupean plants was undertaken to find new extracts and formulations against superficial mycoses such as onychomycosis, athlete's foot, Pityriasis versicolor, as well as the deep fungal infection Pneumocystis pneumonia. For the first time, the CMI of these plant extracts [cyclohexane, ethanol and ethanol/water (1:1, v/v)] was determined against five dermatophytes, five Candida species, Scytalidium dimidiatum, a Malassezia sp. strain and Pneumocystis carinii. Cytotoxicity tests of the most active extracts were also performed on an HaCat keratinocyte cell line. Results suggest that the extracts of Bursera simaruba, Cedrela odorata, Enterolobium cyclocarpum and Pluchea carolinensis have interesting activities and could be good candidates for developing antifungal formulations. Copyright © 2012 John Wiley & Sons, Ltd.

  9. Frequent major errors in antimicrobial susceptibility testing of bacterial strains distributed under the Deutsches Krebsforschungszentrum Quality Assurance Program.

    Science.gov (United States)

    Boot, R

    2012-07-01

    The Quality Assurance Program (QAP) of the Deutsches Krebsforschungszentrum (DKFZ) was a proficiency testing system developed to service the laboratory animal discipline. The QAP comprised the distribution of bacterial strains from various species of animals for identification to species level and antibiotic susceptibility testing (AST). Identification capabilities were below acceptable standards. This study evaluated AST results using the DKFZ compilations of test results for all bacterial strains showing the number of participants reporting the strain as resistant (R), sensitive (S) or intermediate susceptible (I) to each antibiotic substance used. Due to lack of information about methods used, it was assumed that what the majority of the participants reported (R or S) was the correct test result and that an opposite result was a major error (ME). MEs occurred in 1375 of 14,258 (9.7%) of test results and ME% ranged from 0% to 23.2% per bacterial group-agent group combination. Considerable variation in MEs was found within groups of bacteria and within groups of agents. In addition to poor performance in proper species classification, the quality of AST in laboratory animal diagnostic laboratories seems far below standards considered acceptable in human diagnostic microbiology.

  10. Antifungal Efficacy of Myrtus communis Linn

    Directory of Open Access Journals (Sweden)

    Sadeghi Nejad

    2014-08-01

    Full Text Available Background The ethanolic extract of Myrtus communis Linn. leaves was assayed in vitro as a growth inhibitor against opportunistic fungi such as Candida and Aspergillus species. Myrtus communis Linn. (Family, Myrtaceae is an aromatic evergreen shrub or small tree. It is native to the Mediterranean region. Objectives This study aimed to assess antifungal activity (in vitro of the ethanolic extracts of Myrtus communis leaves as a growth inhibitor against 24 clinical isolates of Candida, including C. albicans, C. glabrata, and C. tropicalis also three species of Aspergillus, including A. niger, A. flavus, and A. terreus. Materials and Methods The ethanolic extract of myrtle leaves was prepared by maceration method and minimal inhibitory concentration (MIC of Myrtus communis leaves extract was determined by agar-well diffusion technique. Amphotericin B and clotrimazole were used as the positive control in this assay. Results The minimal inhibitory concentration (MICs values of Myrtus communis leaves extract ranged 0.625-5.0 µg/µL and 5-40 µg/µL against tested Candida spp. and Aspergillus spp., respectively. Conclusions Results revealed that the ethanolic extract of Myrtus communis leaves have antifungal potency against both pathogenic tested fungi, and it can be used as a natural antifungal agent.

  11. WHO global salm-surv external quality assurance system (EQAS): an important step toward improving the quality of Salmonella serotyping and antimicrobial susceptibility testing worldwide

    DEFF Research Database (Denmark)

    Petersen, A.; Aarestrup, Frank Møller; Angulo, F. J.

    2002-01-01

    susceptibility testing through international training courses and an External Quality Assurance System (EQAS). In 2000, 44 WHO Global Salm-Surv member laboratories from 35 countries determined the serotype and antimicrobial susceptibility pattern for eight "blinded" Salmonella isolates. For serotyping, 73...

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

    Science.gov (United States)

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

    2008-01-01

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

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

    Science.gov (United States)

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

    2005-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Ying-Lien Chen

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

  15. Direct nitrate reductase assay versus microscopic observation drug susceptibility test for rapid detection of MDR-TB in Uganda.

    Directory of Open Access Journals (Sweden)

    Freddie Bwanga

    Full Text Available The most common method for detection of drug resistant (DR TB in resource-limited settings (RLSs is indirect susceptibility testing on Lowenstein-Jensen medium (LJ which is very time consuming with results available only after 2-3 months. Effective therapy of DR TB is therefore markedly delayed and patients can transmit resistant strains. Rapid and accurate tests suitable for RLSs in the diagnosis of DR TB are thus highly needed. In this study we compared two direct techniques--Nitrate Reductase Assay (NRA and Microscopic Observation Drug Susceptibility (MODS for rapid detection of MDR-TB in a high burden RLS. The sensitivity, specificity, and proportion of interpretable results were studied. Smear positive sputum was collected from 245 consecutive re-treatment TB patients attending a TB clinic in Kampala, Uganda. Samples were processed at the national reference laboratory and tested for susceptibility to rifampicin and isoniazid with direct NRA, direct MODS and the indirect LJ proportion method as reference. A total of 229 specimens were confirmed as M. tuberculosis, of these interpretable results were obtained in 217 (95% with either the NRA or MODS. Sensitivity, specificity and kappa agreement for MDR-TB diagnosis was 97%, 98% and 0.93 with the NRA; and 87%, 95% and 0.78 with the MODS, respectively. The median time to results was 10, 7 and 64 days with NRA, MODS and the reference technique, respectively. The cost of laboratory supplies per sample was low, around 5 USD, for the rapid tests. The direct NRA and MODS offered rapid detection of resistance almost eight weeks earlier than with the reference method. In the study settings, the direct NRA was highly sensitive and specific. We consider it to have a strong potential for timely detection of MDR-TB in RLS.

  16. Adolescent behavioral and neural reward sensitivity: a test of the differential susceptibility theory.

    Science.gov (United States)

    Richards, J S; Arias Vásquez, A; von Rhein, D; van der Meer, D; Franke, B; Hoekstra, P J; Heslenfeld, D J; Oosterlaan, J; Faraone, S V; Buitelaar, J K; Hartman, C A

    2016-04-05

    Little is known about the causes of individual differences in reward sensitivity. We investigated gene-environment interactions (GxE) on behavioral and neural measures of reward sensitivity, in light of the differential susceptibility theory. This theory states that individuals carrying plasticity gene variants will be more disadvantaged in negative, but more advantaged in positive environments. Reward responses were assessed during a monetary incentive delay task in 178 participants with and 265 without attention-deficit/hyperactivity disorder (ADHD), from N=261 families. We examined interactions between variants in candidate plasticity genes (DAT1, 5-HTT and DRD4) and social environments (maternal expressed emotion and peer affiliation). HTTLPR short allele carriers showed the least reward speeding when exposed to high positive peer affiliation, but the most when faced with low positive peer affiliation or low maternal warmth. DAT1 10-repeat homozygotes displayed similar GxE patterns toward maternal warmth on general task performance. At the neural level, DRD4 7-repeat carriers showed the least striatal activation during reward anticipation when exposed to high maternal warmth, but the most when exposed to low warmth. Findings were independent of ADHD severity. Our results partially confirm the differential susceptibility theory and indicate the importance of positive social environments in reward sensitivity and general task performance for persons with specific genotypes.

  17. Use of the National Committee for Clinical Laboratory Standards Guidelines for Disk Diffusion Susceptibility Testing in New York State Laboratories

    Science.gov (United States)

    Kiehlbauch, Julia A.; Hannett, George E.; Salfinger, Max; Archinal, Wendy; Monserrat, Catherine; Carlyn, Cynthia

    2000-01-01

    Accurate antimicrobial susceptibility testing is vital for patient care and surveillance of emerging antimicrobial resistance. The National Committee for Clinical Laboratory Standards (NCCLS) outlines generally agreed upon guidelines for reliable and reproducible results. In January 1997 we surveyed 320 laboratories participating in the New York State Clinical Evaluation Program for General Bacteriology proficiency testing. Our survey addressed compliance with NCCLS susceptibility testing guidelines for bacterial species designated a problem (Staphylococcus aureus and Enterococcus species) or fastidious (Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria gonorrhoeae) organism. Specifically, we assessed compliance with guidelines for inoculum preparation, medium choice, number of disks per plate, and incubation conditions for disk diffusion tests. We also included length of incubation for S. aureus and Enterococcus species. We found overall compliance with the five characteristics listed above in 80 of 153 responding laboratories (50.6%) for S. aureus and 72 of 151 (47.7%) laboratories for Enterococcus species. The most common problem was an incubation time shortened to less than 24 h. Overall compliance with the first four characteristics was reported by 92 of 221 (41.6%) laboratories for S. pneumoniae, 49 of 163 (30.1%) laboratories for H. influenzae, and 11 of 77 (14.3%) laboratories for N. gonorrhoeae. Laboratories varied from NCCLS guidelines by placing an excess number of disks per plate. Laboratories also reported using alternative media for Enterococcus species, N. gonorrhoeae, and H. influenzae. This study demonstrates a need for education among clinical laboratories to increase compliance with NCCLS guidelines. PMID:10970381

  18. New interpretive criteria for danofloxacin antibacterial susceptibility testing against Mannheimia haemolytica and Pasteurella multocida associated with bovine respiratory disease.

    Science.gov (United States)

    Sweeney, Michael T; Papich, Mark G; Watts, Jeffrey L

    2017-03-01

    Danofloxacin is a fluoroquinolone antibacterial agent approved for use in veterinary medicine to treat and control bovine respiratory disease caused by Mannheimia haemolytica or Pasteurella multocida. Susceptible minimal inhibitory concentration (MIC) breakpoint (≤0.25 µg/mL) and disk diffusion interpretive criteria (≥22 mm) values for danofloxacin against M. haemolytica and P. multocida were first approved by the Clinical and Laboratory Standards Institute (CLSI) in 2003. However, intermediate and resistant breakpoint values were not established because only susceptible wild-type populations were evident at the time of breakpoint approvals. Since then, nonsusceptible isolates of M. haemolytica and P. multocida have been identified. We report danofloxacin intermediate MIC breakpoint (0.5 µg/mL) and disk diffusion interpretive criteria (18-21 mm), as well as danofloxacin-resistant MIC breakpoint (≥1 µg/mL) and disk diffusion interpretive criteria (≤17 mm), based on scattergram plots of MIC values versus disk zone diameters and calculated error-bound rates using M. haemolytica and P. multocida isolates recovered from bovine respiratory disease in North America in 2004-2014. These newly established intermediate and resistant clinical breakpoint values have been endorsed by CLSI and can be used for interpreting results from antibacterial susceptibility testing of danofloxacin against M. haemolytica and P. multocida isolated from bovine respiratory disease.

  19. Multifactor-dimensionality reduction versus family-based association tests in detecting susceptibility loci in discordant sib-pair studies

    Science.gov (United States)

    Meng, Yan; Ma, Qianli; Yu, Yi; Farrell, John; Farrer, Lindsay A; Wilcox, Marsha A

    2005-01-01

    Complex diseases are generally thought to be under the influence of multiple, and possibly interacting, genes. Many association methods have been developed to identify susceptibility genes assuming a single-gene disease model, referred to as single-locus methods. Multilocus methods consider joint effects of multiple genes and environmental factors. One commonly used method for family-based association analysis is implemented in FBAT. The multifactor-dimensionality reduction method (MDR) is a multilocus method, which identifies multiple genetic loci associated with the occurrence of complex disease. Many studies of late onset complex diseases employ a discordant sib pairs design. We compared the FBAT and MDR in their ability to detect susceptibility loci using a discordant sib-pair dataset generated from the simulated data made available to participants in the Genetic Analysis Workshop 14. Using FBAT, we were able to identify the effect of one susceptibility locus. However, the finding was not statistically significant. We were not able to detect any of the interactions using this method. This is probably because the FBAT test is designed to find loci with major effects, not interactions. Using MDR, the best result we obtained identified two interactions. However, neither of these reached a level of statistical significance. This is mainly due to the heterogeneity of the disease trait and noise in the data. PMID:16451606

  20. Multifactor-dimensionality reduction versus family-based association tests in detecting susceptibility loci in discordant sib-pair studies.

    Science.gov (United States)

    Meng, Yan; Ma, Qianli; Yu, Yi; Farrell, John; Farrer, Lindsay A; Wilcox, Marsha A

    2005-12-30

    Complex diseases are generally thought to be under the influence of multiple, and possibly interacting, genes. Many association methods have been developed to identify susceptibility genes assuming a single-gene disease model, referred to as single-locus methods. Multilocus methods consider joint effects of multiple genes and environmental factors. One commonly used method for family-based association analysis is implemented in FBAT. The multifactor-dimensionality reduction method (MDR) is a multilocus method, which identifies multiple genetic loci associated with the occurrence of complex disease. Many studies of late onset complex diseases employ a discordant sib pairs design. We compared the FBAT and MDR in their ability to detect susceptibility loci using a discordant sib-pair dataset generated from the simulated data made available to participants in the Genetic Analysis Workshop 14. Using FBAT, we were able to identify the effect of one susceptibility locus. However, the finding was not statistically significant. We were not able to detect any of the interactions using this method. This is probably because the FBAT test is designed to find loci with major effects, not interactions. Using MDR, the best result we obtained identified two interactions. However, neither of these reached a level of statistical significance. This is mainly due to the heterogeneity of the disease trait and noise in the data.

  1. Fusarium keratitis in Brazil: genotyping, in vitro susceptibilities, and clinical outcomes

    Directory of Open Access Journals (Sweden)

    Oechsler RA

    2013-08-01

    Full Text Available Rafael A Oechsler,1 Tiago M Yamanaka,1 Paulo JM Bispo,1 Juliana Sartori,1 Maria Cecilia Zorat Yu,1 Analy Salles A Melo,2 Darlene Miller,3 Ana Luisa Hofling-Lima1 1Ophthalmology Department, 2Division of Infectious Diseases, Internal Medicine Department, Federal University of São Paulo, São Paulo, Brazil; 3Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA Background: The purpose of this paper is to describe clinical characteristics and determine correlations between clinical outcomes and antifungal susceptibility among molecularly characterized ocular Fusarium isolates in Brazil. Methods: Forty-one Fusarium isolates obtained from 41 eyes of 41 patients were retrieved from the ophthalmic microbiology laboratory at São Paulo Federal University and grown in pure culture. These isolates were genotyped and antifungal susceptibilities determined for each isolate using a broth microdilution method. The corresponding medical records were reviewed to determine clinical outcomes. Results: The 41 isolates were genotypically classified as Fusarium solani species complex (36 isolates, 88%, Fusarium oxysporum species complex (two isolates, 5%, Fusarium dimerum species complex (one isolate, 2% and two isolates that did not group into any of the species complexes. Final best corrected visual acuity varied from 20/20 to light perception and was on average 20/800 (logarithm of the minimum angle of resolution (LogMAR 1.6. A history of trauma was the most common risk factor, being present in 21 patients (51%. Therapeutic penetrating keratoplasty was necessary in 22 patients (54%. Amphotericin B had the lowest minimum inhibitory concentration for 90% of isolates (MIC90 value (2 µg/mL and voriconazole had the highest (16 µg/mL. There was an association between a higher natamycin MIC and need for therapeutic penetrating keratoplasty (Mann–Whitney test, P < 0.005. Conclusion: Trauma was the main risk factor, and

  2. First isolation and antimicrobial susceptibility testing of Chromobacterium violaceum from oysters in Mexico

    Directory of Open Access Journals (Sweden)

    R. Berebichez-Fridman

    2018-04-01

    Full Text Available Introduction: Chromobacterium violaceum is a Gram-negative, facultative, anaerobic, non-sporing, fermentative and oxidase-positive coccobacillus. Human infections caused by Chromobacterium violaceum are infrequent. There are a few reported cases in several countries. Those infections appear after a skin contact with soil or contaminated water. Infections can progress to necrotizing metastatatic lesions and multiple abscesses of the lung, liver, skin, spleen, lymph nodes and brain with fatal septicemia. Infections caused by this bacterium have a high lethality rate, with a low recovery rate among survivors. It has been described that this bacterium is resistant to several antibiotics. Materials and methods: Chromobacterium violaceum was isolated, cultivated, and identified from oysters from thirteen different restaurants in Mexico City and antimicrobial susceptibility testing was performed. Results: Four isolations of Chromobacterium violaceum were obtained from oysters. Three of them corresponded to biotype 36 and all of them had a confidence factor of 0.987. All isolations were resistant to Carbencillin, Cephalothin and Cephotaxime. Two isolations were also resistant to Ampicillin and one was resistant to Amikacin. All isolations were sensitive to Ceftriaxone, Chloramphenicol, Gentamicin, Netilmicin, Nitrofurantoin, Pefloxacine and Trimethoprim-Sulfamethoxazole. Conclusions: The presence of Chromabacterium violaceum in food obtained from salt marshes that usually are eaten fresh (like oysters means a high potential risk for human health because this bacterium has been associated with high morbidity and mortality. In our report, this bacterium showed resistance to several antibacterial agents. Patients should be cautions when eating fresh seafood, and healthcare personnel should suspect an infection caused by Chromobacterium violaceum if the patient presents with sepsis, enteritis or abscesses and they have risk factors for acquiring this

  3. Antimicrobial susceptibility testing of Clostridium difficile using EUCAST epidemiological cut-off values and disk diffusion correlates

    DEFF Research Database (Denmark)

    Erikstrup, Lise Tornvig; Danielsen, T K L; Hall, V

    2012-01-01

    Clin Microbiol Infect ABSTRACT: With the emergence of reduced susceptibility of Clostridium difficile to metronidazole and vancomycin the value of antimicrobial susceptibility testing has increased. The aim of our study was to evaluate disk diffusion for susceptibility testing of C. difficile by ......Clin Microbiol Infect ABSTRACT: With the emergence of reduced susceptibility of Clostridium difficile to metronidazole and vancomycin the value of antimicrobial susceptibility testing has increased. The aim of our study was to evaluate disk diffusion for susceptibility testing of C...... University Hospitals, Denmark. Furthermore, ten clinical isolates of C. difficile from the Anaerobe Reference Laboratory, University Hospital of Wales, with known reduced susceptibility to either metronidazole or vancomycin, were included. Isolates were tested with Etest gradient strips and disk diffusion...... towards metronidazole, vancomycin and moxifloxacin on Brucella Blood Agar supplemented with hemin and vitamin K. We found an excellent agreement between inhibition zone diameter and MICs. For each MIC value, the inhibition zones varied from 0 to 8 mm, with 93% of values within 6 mm for metronidazole, 95...

  4. Assessing the anti-fungal efficiency of filters coated with zinc oxide nanoparticles

    Science.gov (United States)

    Decelis, Stephen; Sardella, Davide; Triganza, Thomas; Brincat, Jean-Pierre; Gatt, Ruben; Valdramidis, Vasilis P.

    2017-05-01

    Air filters support fungal growth, leading to generation of conidia and volatile organic compounds, causing allergies, infections and food spoilage. Filters that inhibit fungi are therefore necessary. Zinc oxide (ZnO) nanoparticles have anti-fungal properties and therefore are good candidates for inhibiting growth. Two concentrations (0.012 M and 0.12 M) were used to coat two types of filters (melt-blown and needle-punched) for three different periods (0.5, 5 and 50 min). Rhizopus stolonifer and Penicillium expansum isolated from spoiled pears were used as test organisms. Conidial suspensions of 105 to 103 spores ml-1 were prepared in Sabouraud dextrose agar at 50°C, and a modified slide-culture technique was used to test the anti-fungal properties of the filters. Penicillium expansum was the more sensitive organism, with inhibition at 0.012 M at only 0.5 min coating time on the needle-punched filter. The longer the coating time, the more effective inhibition was for both organisms. Furthermore, it was also determined that the coating process had only a slight effect on the Young's Moduli of the needle-punched filters, while the Young's Moduli of the melt-blown filters is more susceptible to the coating method. This work contributes to the assessment of the efficacy of filter coating with ZnO nanopaticles aimed at inhibiting fungal growth.

  5. Antifungal Activity of Maytenin and Pristimerin

    Science.gov (United States)

    Gullo, Fernanda P.; Sardi, Janaina C. O.; Santos, Vânia A. F. F. M.; Sangalli-Leite, Fernanda; Pitangui, Nayla S.; Rossi, Suélen A.; de Paula e Silva, Ana C. A.; Soares, Luciana A.; Silva, Julhiany F.; Oliveira, Haroldo C.; Furlan, Maysa; Silva, Dulce H. S.; Bolzani, Vanderlan S.; Mendes-Giannini, Maria José S.; Fusco-Almeida, Ana Marisa

    2012-01-01

    Fungal infections in humans have increased alarmingly in recent years, particularly in immunocompromised individuals. Among the infections systemic candidiasis, aspergillosis, cryptococcosis, paracoccidioidomycosis, and histoplasmosis mortality are more prevalent and more severe in humans. The current high incidence of dermatophytosis is in humans, especially as the main etiologic agents Trichophyton rubrum and Trichophyton mentagrophytes. Molecules pristimerin and maytenin obtained from the plant Maytenus ilicifolia (Celastraceae) are known to show various pharmacological activities. This study aimed to evaluate the spectrum of antifungal activity of maytenin and pristimerin and their cytotoxicity in human keratinocytes (NOK cells of the oral mucosa). It was concluded that the best spectrum of antifungal activity has been shown to maytenin with MIC varying from 0.12 to 125 mg/L, although it is also active with pristimerin MIC ranging between 0.12 and 250 mg/L. Regarding the toxicity, both showed to have high IC50. The SI showed high pristimerin against some species of fungi, but SI maytenin was above 1.0 for all fungi tested, showing a selective action of fungi. However, when comparing the two substances, maytenin also showed better results. The two molecules can be a possible prototype with a broad spectrum of action for the development of new antifungal agents. PMID:22675379

  6. Antifungal Activity of Maytenin and Pristimerin

    Directory of Open Access Journals (Sweden)

    Fernanda P. Gullo

    2012-01-01

    Full Text Available Fungal infections in humans have increased alarmingly in recent years, particularly in immunocompromised individuals. Among the infections systemic candidiasis, aspergillosis, cryptococcosis, paracoccidioidomycosis, and histoplasmosis mortality are more prevalent and more severe in humans. The current high incidence of dermatophytosis is in humans, especially as the main etiologic agents Trichophyton rubrum and Trichophyton mentagrophytes. Molecules pristimerin and maytenin obtained from the plant Maytenus ilicifolia (Celastraceae are known to show various pharmacological activities. This study aimed to evaluate the spectrum of antifungal activity of maytenin and pristimerin and their cytotoxicity in human keratinocytes (NOK cells of the oral mucosa. It was concluded that the best spectrum of antifungal activity has been shown to maytenin with MIC varying from 0.12 to 125 mg/L, although it is also active with pristimerin MIC ranging between 0.12 and 250 mg/L. Regarding the toxicity, both showed to have high IC50. The SI showed high pristimerin against some species of fungi, but SI maytenin was above 1.0 for all fungi tested, showing a selective action of fungi. However, when comparing the two substances, maytenin also showed better results. The two molecules can be a possible prototype with a broad spectrum of action for the development of new antifungal agents.

  7. A survey of methods used for antimicrobial susceptibility testing in veterinary diagnostic laboratories in the United States.

    Science.gov (United States)

    Dargatz, David A; Erdman, Matthew M; Harris, Beth

    2017-09-01

    Antimicrobial resistance is a serious threat to animal and human health worldwide, requiring a collaborative, holistic approach. The U.S. Government has developed a national strategy to address antimicrobial resistance, with one component being to monitor antimicrobial resistance in agricultural settings. We developed a survey to collect information about antimicrobial susceptibility testing (AST) from the veterinary diagnostic laboratory community in the United States, assessing current practices and technologies and determining how AST information is shared. Of the 132 surveys administered, 52 (39%) were returned. Overall, responding laboratories conducted susceptibility tests on 98,788 bacterial isolates in 2014, with Escherichia coli being the most common pathogen tested across all animal species. The 2 most common AST methods employed were the disk diffusion method (71%) and the Sensititre platform broth microdilution system (59%). Laboratories primarily used the Clinical Laboratory Standards Institute (CLSI) VET-01 standard (69%) and the automatically calculated interpretations provided by the commercial AST systems (61%) for interpreting their AST data. Only 22% of laboratories published AST data on a periodic basis, usually via annual reports published on the laboratory's website or through peer-reviewed journals for specific pathogens. Our results confirm that disk diffusion and broth microdilution remain the standard AST methods employed by U.S. veterinary diagnostic laboratories, and that CLSI standards are commonly used for interpreting AST results. This information will help determine the most efficient standardized methodology for future surveillance. Furthermore, the current infrastructure within laboratories, once harmonized, will help provide a mechanism for conducting national surveillance programs.

  8. [Consensus for antimicrobial susceptibility testing for Enterobacteriaceae. Subcommittee on Antimicrobials, SADEBAC (Argentinian Society of Clinical Bacteriology), Argentinian Association of Microbiology].

    Science.gov (United States)

    Famiglietti, A; Quinteros, M; Vázquez, M; Marín, M; Nicola, F; Radice, M; Galas, M; Pasterán, F; Bantar, C; Casellas, J M; Kovensky Pupko, J; Couto, E; Goldberg, M; Lopardo, H; Gutkind, G; Soloaga, R

    2005-01-01

    Taking into account previous recommendations from the National Committee for Clinical Laboratory Standards (NCCLS), the Antimicrobial Committee, Sociedad Argentina de Bacteriología Clínica (SADEBAC), Asociación Argentina de Microbiología (AAM), and the experience from its members and some invited microbiologists, a consensus was obtained for antimicrobial susceptibility testing and interpretation in most frequent enterobacterial species isolated from clinical samples in our region. This document describes the natural antimicrobial resistance of some Enterobacteriaceae family members, including the resistance profiles due to their own chromosomal encoded beta-lactamases. A list of the antimicrobial agents that should be tested, their position on the agar plates, in order to detect the most frequent antimicrobial resistance mechanisms, and considerations on which antimicrobial agents should be reported regarding to the infection site and patient characteristics are included. Also, a description on appropriate phenotypic screening and confirmatory test for detection of prevalent extended spectrum beta-lactamases in our region are presented. Finally, a summary on frequent antimicrobial susceptibility profiles and their probably associated resistance mechanisms, and some infrequent antimicrobial resistance profiles that deserve confirmation are outlined.

  9. Results of Use of WHO Global Salm-Surv External Quality Assurance System for Antimicrobial Susceptibility Testing of Salmonella Isolates from 2000 to 2007

    DEFF Research Database (Denmark)

    Hendriksen, Rene S.; Seyfarth, Anne Mette; Jensen, Arne Bent

    2009-01-01

    to 3% in 2007. Consistent difficulties were observed in susceptibility testing of amoxicillin-clavulanic acid, cefotaxime, ceftazidime, streptomycin, sulfonamides, and tetracycline. Regional variations in performance were observed, with laboratories in central Asia, Africa, and the Middle East...

  10. Loss of C-5 Sterol Desaturase Activity Results in Increased Resistance to Azole and Echinocandin Antifungals in a Clinical Isolate of Candida parapsilosis.

    Science.gov (United States)

    Rybak, Jeffrey M; Dickens, C Michael; Parker, Josie E; Caudle, Kelly E; Manigaba, Kayihura; Whaley, Sarah G; Nishimoto, Andrew T; Luna-Tapia, Arturo; Roy, Sujoy; Zhang, Qing; Barker, Katherine S; Palmer, Glen E; Sutter, Thomas R; Homayouni, Ramin; Wiederhold, Nathan P; Kelly, Steven L; Rogers, P David

    2017-09-01

    Among emerging non- albicans Candida species, Candida parapsilosis is of particular concern as a cause of nosocomial bloodstream infections in neonatal and intensive care unit patients. While fluconazole and echinocandins are considered effective treatments for such infections, recent reports of fluconazole and echinocandin resistance in C. parapsilosis indicate a growing problem. The present study describes a novel mechanism of antifungal resistance in this organism affecting susceptibility to azole and echinocandin antifungals in a clinical isolate obtained from a patient with prosthetic valve endocarditis. Transcriptome analysis indicated differential expression of several genes in the resistant isolate, including upregulation of ergosterol biosynthesis pathway genes ERG2 , ERG5 , ERG6 , ERG11 , ERG24 , ERG25 , and UPC2 Whole-genome sequencing revealed that the resistant isolate possessed an ERG3 mutation resulting in a G111R amino acid substitution. Sterol profiles indicated a reduction in sterol desaturase activity as a result of this mutation. Replacement of both mutant alleles in the resistant isolate with the susceptible isolate's allele restored wild-type susceptibility to all azoles and echinocandins tested. Disruption of ERG3 in the susceptible and resistant isolates resulted in a loss of sterol desaturase activity, high-level azole resistance, and an echinocandin-intermediate to -resistant phenotype. While disruption of ERG3 in C. albicans resulted in azole resistance, echinocandin MICs, while elevated, remained within the susceptible range. This work demonstrates that the G111R substitution in Erg3 is wholly responsible for the altered azole and echinocandin susceptibilities observed in this C. parapsilosis isolate and is the first report of an ERG3 mutation influencing susceptibility to the echinocandins. Copyright © 2017 American Society for Microbiology.

  11. Irradiation Programs and Test Plans to Assess High-Fluence Irradiation Assisted Stress Corrosion Cracking Susceptibility.

    Energy Technology Data Exchange (ETDEWEB)

    Teysseyre, Sebastien [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    . Irradiation assisted stress corrosion cracking (IASCC) is a known issue in current reactors. In a 60 year lifetime, reactor core internals may experience fluence levels up to 15 dpa for boiling water reactors (BWR) and 100+ dpa for pressurized water reactors (PWR). To support a safe operation of our fleet of reactors and maintain their economic viability it is important to be able to predict any evolution of material behaviors as reactors age and therefore fluence accumulated by reactor core component increases. For PWR reactors, the difficulty to predict high fluence behavior comes from the fact that there is not a consensus of the mechanism of IASCC and that little data is available. It is however possible to use the current state of knowledge on the evolution of irradiated microstructure and on the processes that influences IASCC to emit hypotheses. This report identifies several potential changes in microstructure and proposes to identify their potential impact of IASCC. The susceptibility of a component to high fluence IASCC is considered to not only depends on the intrinsic IASCC susceptibility of the component due to radiation effects on the material but to also be related to the evolution of the loading history of the material and interaction with the environment as total fluence increases. Single variation type experiments are proposed to be performed with materials that are representative of PWR condition and with materials irradiated in other conditions. To address the lack of IASCC propagation and initiation data generated with material irradiated in PWR condition, it is proposed to investigate the effect of spectrum and flux rate on the evolution of microstructure. A long term irradiation, aimed to generate a well-controlled irradiation history on a set on selected materials is also proposed for consideration. For BWR, the study of available data permitted to identify an area of concern for long term performance of component. The efficiency of

  12. Same-day identification and antibiotic susceptibility testing on positive blood cultures: a simple and inexpensive procedure.

    Science.gov (United States)

    Maelegheer, K; Nulens, E

    2017-04-01

    Fast diagnostic tools are becoming a hot topic in microbiology, especially in the case of septic patients. Therefore, we attempted to develop a fast, inexpensive, accurate and easy method to identify bacteria and perform an antibiotic susceptibility test directly on positive blood cultures that could be used in a routine laboratory. A procedure based on centrifugation and washing steps was performed on 110 non-duplicated (including nine seeded) positive blood culture bottles. Direct identification (DID) and antimicrobial susceptibility testing (AST) was conducted on the pellet with the MALDI Biotyper and Phoenix, respectively. Identification (ID) to the species level was correct in 44/45 (97%) cases for Gram-negative bacteria and 44/56 (79%) cases for Gram-positive bacteria. In total, 98.9% of the AST results were identical to the routine laboratory result. No very major errors, four major errors and eight minor errors were detected. A reliable identification and a high AST agreement were obtained from blood cultures seeded with multi-resistant bacteria. We simulated the timeline of DID and demonstrated an identification and AST result within 24 h using Escherichia coli- and Staphylococcus aureus-positive blood cultures as examples. We developed an easy, fast and cheap method to generate reliable ID and AST results. Moreover, this method may be used to obtain results within 24 h after incubating the blood culture bottles in the microbiology lab.

  13. Infant temperament, parenting, and externalizing behavior in first grade: a test of the differential susceptibility hypothesis.

    Science.gov (United States)

    Bradley, Robert H; Corwyn, Robert F

    2008-02-01

    This study examines the differential susceptibility hypothesis as it pertains to relations between infant temperament, parenting, and behavior problems in first grade. Data from the NICHD Study of Early Child Care were used in a series of hierarchical regression analyses focused on interactions between three aspects of parenting (harshness, sensitivity, productive activity) and temperament as they affect teacher-reported externalizing behavior in first grade. Step #1 included family income-to-needs, maternal education, gender, life events, and amount of child care as control variables, plus infant temperament and the three parenting variables. Step #2 included a single interaction term, the interaction between one of the key parenting variables and child temperament. Results showed stronger relations between maternal sensitivity and behavior problems for children with difficult temperaments. Likewise, relations between opportunities for productivity and behavior problems were stronger for children with difficult temperaments. Trends were in the same direction for harsh parenting but did not quite reach statistical significance. Having access to experiences that promote coping and build self-regulatory capacities seems particularly valuable for children with difficult temperaments.

  14. Interim susceptibility testing for ceftaroline, a new MRSA-active cephalosporin: selecting potent surrogate β-lactam markers to predict ceftaroline activity against clinically indicated species.

    Science.gov (United States)

    Jones, Ronald N; Flamm, Robert K; Sader, Helio S; Stilwell, Matthew G

    2013-01-01

    Ceftaroline, the bio-active form of parenterally administered ceftaroline fosamil, is a unique broad-spectrum cephalosporin with in vitro and in vivo activity against methicillin-resistant Staphylococcus aureus and was approved for clinical use by the United States Food and Drug Administration in October 2010. In over a year since ceftaroline fosamil approval, no widely used commercial susceptibility test system has added this new compound to its product, therefore requiring use of alternative agar diffusion methods for clinical microbiology laboratories that want to test clinical isolates for ceftaroline susceptibility. An alternative strategy of applying a surrogate β-lactam class marker agent was assessed here, using results from 14,902 organisms (2008-2010) sampled in the USA. Very high and acceptable accuracy (≥ 99.75%) was observed for predicting ceftaroline susceptibility as follows: 1) use of imipenem or meropenem minimum inhibitory concentrations (MICs) at ≤ 8 μg/mL (susceptible and intermediate categories) when testing S. aureus; 2) use of ceftriaxone MIC at ≤ 2 μg/mL (susceptible and intermediate categories) when testing Streptococcus pneumoniae as well as other streptococci (S. pyogenes and S. agalactiae); and 3) use of ceftriaxone, or cefepime, or ceftazidime at ≤ 2 μg/mL (susceptible category) when testing Haemophilus influenzae. Only when testing indicated Enterobacteriaceae species using ceftriaxone susceptibility results did the ceftaroline-nonsusceptible errors increase (4.11%). These presented analyses offer a validated surrogate marker strategy for ceftaroline susceptibility testing, pending development and validation by the commonly used automated systems and agar diffusion commercial methods. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2016-02-01

    Fungal nail infection (onychomycosis) is a prevalent disease in many areas of the world, with a high incidence approaching 23%. Available antifungals to treat the disease suffer from a number of disadvantages, necessitating the discovery of new efficacious and safe antifungals. Here, we evaluate the in vitro antifungal activity and nail penetration ability of ME1111, a novel antifungal agent, along with comparator drugs, including ciclopirox, amorolfine, terbinafine, and itraconazole. ME1111 showed potent antifungal activity against Trichophyton rubrum and Trichophyton mentagrophytes (the major etiologic agents of onychomycosis) strains isolated in Japan and reference fungal strains with an MIC range of 0.12 to 0.5 mg/liter and an MIC50 and MIC90 of 0.5 mg/liter for both. Importantly, none of the tested isolates showed an elevated ME1111 MIC. Moreover, the antifungal activity of ME1111 was minimally affected by 5% wool keratin powder in comparison to the other antifungals tested. The ME1111 solution was able to penetrate human nails and inhibit fungal growth in a dose-dependent manner according to the TurChub assay. In contrast, 8% ciclopirox and 5% amorolfine nail lacquers showed no activity under the same conditions. ME1111 demonstrated approximately 60-fold-greater selectivity in inhibition of Trichophyton spp. than of human cell lines. Our findings demonstrate that ME1111 possesses potent antidermatophyte activity, maintains this activity in the presence of keratin, and possesses excellent human nail permeability. These results suggest that ME1111 is a promising topical medication for the treatment of onychomycosis and therefore warrants further clinical evaluation. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

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

    Science.gov (United States)

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

    2015-01-01

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

  17. Emerging Resistance, New Antimicrobial Agents  …  but No Tests! The Challenge of Antimicrobial Susceptibility Testing in the Current US Regulatory Landscape.

    Science.gov (United States)

    Humphries, R M; Hindler, J A

    2016-07-01

    Accurate and timely performance of antimicrobial susceptibility testing (AST) by the clinical laboratory is paramount to combating antimicrobial resistance. The ability of laboratories in the United States to effectively perform ASTs is challenged by several factors. Some, such as new resistance mechanisms and the associated evolution of testing recommendations and breakpoints, are inevitable. Others are entirely man-made. These include unnecessarily strict US Food and Drug Administration (FDA) limitations on how commercial AST systems can be used for diagnostic testing, the absence of up-to-date performance data on these systems, and the lack of commercially available FDA-cleared tests for newer antimicrobial agents or for older agents with updated breakpoints. This viewpoint will highlight contemporary AST challenges faced by the clinical laboratory, and propose some solutions. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  18. Antifungal susceptibility of Candida albicans isolated from oral mucosa of patients with cancer Suscetibilidade de Candida albicans a antifúngicos: cepas isoladas da mucosa bucal de pacientes com câncer

    Directory of Open Access Journals (Sweden)

    Lino João da COSTA

    1999-07-01

    Full Text Available The increasing number of oral infections due to opportunistic fungi in immunocompromised patients, needs a new evaluation of the drugs in use. The susceptibility in vitro of Candida albicans strains from the oral mucosa of cancer patients to amphotericin B, ketoconazole, miconazole, fluconazole and itraconazole were evaluated. A dilution technique in YNB agar or subculture on Sabouraud agar was utilised for MIC or MFC determinations. With this methodology, the best fungicidal drug for C.albicans collected from the oral mucosa of 40 cancer patients, divided in two groups: one treated by radiotherapy and the other not, the best results were obtained with amphotericin B, presenting low values of MIC compared to azoles and MFC values. However it is important to take into consideration the utilisation in vivo of this polyenic antibiotic and the possible toxic levels necessary to achieve good results. The coexistence of other fungi and the local conditions must also be pondered with these patients, who are mostly undergoing radiotherapy. In order to achieve better results without undesirable consequences, higher levels of MIC are expected with the daily clinical use of new drugs.O crescente número de infecções fúngicas bucais em pacientes imunocomprometidos tem estimulado a pesquisa de drogas mais eficientes. Procuramos, assim, avaliar a suscetibilidade in vitro de cepas de Candida albicans de pacientes com câncer submetidos ou não a radioterapia frente às seguintes drogas: anfotericina B, cetoconazol, miconazol e itraconazol. A técnica de diluição em ágar YNB e o subcultivo em AS foram respectivamente utilizados para determinação da CIM (Concentração Inibitória Mínima e da CFM (Concentração Fungicida Mínima. Com esta metodologia, a droga que mostrou melhor atividade antifúngica para cepas de C. albicans isoladas de qualquer dos grupos de pacientes foi a anfotericina B, apresentando baixos valores de CIM em comparação aos az

  19. Cefoperazone and cefoperazone-sulbactam susceptibility tests with anaerobic bacteria by the thioglycolate disk elution method.

    OpenAIRE

    Barry, A L; Packer, R R; Jones, R N

    1985-01-01

    Tests were performed with 104 anaerobic microorganisms to evaluate the thioglycolate disk elution technique for the detection of resistance to cefoperazone and cefoperazone-sulbactam. An unacceptably high false-resistance rate and a poor reproducibility record make the disk elution procedure unsatisfactory for routine testing of this drug or combination of drugs.

  20. State of the art report on the materials testing capabilities for IASCC susceptibility testing at SCK-CEN

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, R.-W.; Boydens, P.; Vankeerbergen, R.; Van Nieuwenhove, R.; Van Dyck, S

    1999-08-01

    An overview of the current IASCC testing facilities at the Belgian Nuclear Research Centre SCK-CEN is given. The testing techniques are reviewed, and their capabilities as well as their limitations are discussed. Possible future developments in testing techniques are discussed. IASCC is caused by a complex interaction between materials, its environment and mechanical stresses. Characterisation techniques assessing mechanical stresses as well as electrochemical and microstructural characteristics are reported on.

  1. Studies on antimicrobial and antifungal activities of ziziphus mauritiana human clinical bacterial and fungal pathogens

    International Nuclear Information System (INIS)

    Amin, A.; Shah, S.; Khan, M.A.; Khan, M.M.

    2012-01-01

    The antimicrobial and antifungal activities of crude extracts of Ziziphus mauritiana leaves were investigated against six selected bacterial (Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa, Enterobacter, Klebsiella pneumoniae) and one fungal pathogen (Aspel-gillus niger). The crude extract was further fractionated in butanol, choloroform, n-hexane and methanol. Agar well diffusion and agar dilution assay were employed for determination of zones of inhibition and MICs, respectively, whereas MBC was determined using broth dilution test. The butanol fraction presented encouraging antimicrobial activity (15.0%0.02), while methanol (7.03:1:0.05) and chloroform (7.0%0,05) fractions emerged with significantly low susceptibility. The n-hexane fraction was recorded as almost inactive (0%0) against all bacterial pathogens. Unlike the antibacterial activities, all fractions possessed momentous antifungal activities except the methanol fraction (0%0). The n-hexane fraction showed widest zone of inhibition (11:1:0.05) followed by butanol (8.0%0.02) and chloroform (7.0%0.02). (author)

  2. Synthesis, Antimycobacterial, Antifungal and Photosynthesis-Inhibiting Activity of Chlorinated N-phenylpyrazine-2-carboxamides †

    Directory of Open Access Journals (Sweden)

    Katarina Kralova

    2010-11-01

    Full Text Available A series of sixteen pyrazinamide analogues with the -CONH- linker connecting the pyrazine and benzene rings was synthesized by the condensation of chlorides of substituted pyrazinecarboxylic acids with ring-substituted (chlorine anilines. The prepared compounds were characterized and evaluated for their antimycobacterial and antifungal activity, and for their ability to inhibit photosynthetic electron transport (PET. 6-Chloro-N-(4-chlorophenylpyrazine-2-carboxamide manifested the highest activity against Mycobacterium tuberculosis strain H37Rv (65% inhibition at 6.25 μg/mL. The highest antifungal effect against Trichophyton mentagrophytes, the most susceptible fungal strain tested, was found for 6-chloro-5-tert-butyl-N-(3,4-dichlorophenylpyrazine-2-carboxamide (MIC = 62.5 μmol/L. 6-Chloro-5-tert-butyl-N-(4-chlorophenylpyrazine-2-carboxamide showed the highest PET inhibition in spinach chloroplasts (Spinacia oleracea L. chloroplasts (IC50 = 43.0 μmol/L. For all the compounds, the relationships between the lipophilicity and the chemical structure of the studied compounds as well as their structure-activity relationships are discussed.

  3. Phytochemical analysis, antibacterial, and antifungal assessment of aerial parts of Polygonatum verticillatum.

    Science.gov (United States)

    Khan, Haroon; Saeed, Muhammad; Muhammad, Naveed; Perviz, Samreen

    2016-05-01

    The current study was designed to assess the phytochemical profile, antibacterial, and antifungal activities of the crude methanol extract of the aerial parts of Polygonatum verticillatum (PA) and its various subsequent solvent fractions using agar well diffusion, agar tube dilution, and microdilution methods. Phytochemical analysis showed positive for different chemical groups and also contained marked quantity of saponin and flavonoid contents. Significant antibacterial activity was observed against various tested pathogenic bacteria. The only susceptible Gram-positive bacterium was Bacillus subtilis and their minimum inhibitory concentrations (MICs) measured ranged from 11-50 µg/ml. The sensitive Gram-negative bacteria were Salmonella typhi and Shigella flexeneri The estimated MICs were in the range of 2-7 µg/ml and 8-50 µg/ml for S. typhi and S. flexeneri, respectively. However, the antifungal activity of the plant was limited to Microsporum canis and their MICs ranged from 60 to 250 µg/ml. Our study confirmed significant antibacterial potential of the plant and substantiated its folk use in dysentery and pyrexia of multiple origins. © The Author(s) 2013.

  4. Viable quantitative PCR for assessing the response of Candida albicans to antifungal treatment.

    Science.gov (United States)

    Agustí, Gemma; Fittipaldi, Mariana; Morató, Jordi; Codony, Francesc

    2013-01-01

    Propidium monoazide (PMA) or ethidium bromide monoazide (EMA) treatment has been used before nucleic acid detection methods, such as PCR, to distinguish between live and dead cells using membrane integrity as viability criterion. The performance of these DNA intercalating dyes was compared in many studies utilizing different microorganisms. These studies demonstrated that EMA and PMA differ in their abilities to identify nonviable cells from mixed cell populations, depending on the microorganism and the nature of the sample. Due to this heterogeneity, both dyes were used in the present study to specifically distinguish dead from live Candida albicans cells using viable quantitative PCR (qPCR). The viable qPCR was optimized, and the best results were obtained when pre-treating the cells for 10 min in the dark with 25 μM EMA followed by continuous photoactivation for 15 min. The suitability of this technique to distinguish clotrimazole- and fluconazole-treated C. albicans cells from untreated cells was then assessed. Furthermore, the antifungal properties of two commercial essential oils (Thymus vulgaris and Matricaria chamomilla) were evaluated. The viable qPCR method was determined to be a feasible technique for assessing the viability of C. albicans after drug treatment and may help to provide a rapid diagnostic and susceptibility testing method for fungal infections, especially for patients treated with antifungal therapies.

  5. ISOLATION AND ANTIBIOTIC SUSCEPTIBILITY TESTING OF RAPIDLY-GROWING MYCOBACTERIA FROM GRASSLAND SOILS

    Directory of Open Access Journals (Sweden)

    Martina Kyselková

    2013-08-01

    Full Text Available Rapidly growing mycobacteria (RGM are common soil saprophytes, but certain strains cause infections in human and animals. The infections due to RGM have been increasing in past decades and are often difficult to treat. The susceptibility to antibiotics is regularly evaluated in clinical isolates of RGM, but the data on soil RGM are missing. The objectives of this study was to isolate RGM from four grassland soils with different impact of manuring, and assess their resistance to antibiotics and the ability to grow at 37°C and 42°C. Since isolation of RGM from soil is a challenge, a conventional decontamination method (NaOH/malachite green/cycloheximide and a recent method based on olive oil/SDS demulsification were compared. The olive oil/SDS method was less efficient, mainly because of the emulsion instability and plate overgrowing with other bacteria. Altogether, 44 isolates were obtained and 23 representatives of different RGM genotypes were screened. The number of isolates per soil decreased with increasing soil pH, consistently with previous findings that mycobacteria were more abundant in low pH soils. Most of the isolates belonged to the Mycobacterium fortuitum group. The majority of isolates was resistant to 2-4 antibiotics. Multiresistant strains occurred also in a control soil that has a long history without the exposure to antibiotic-containing manure. Seven isolates grew at 37°C, including the species M. septicum and M. fortuitum known for infections in humans. This study shows that multiresistant RGM close to known human pathogens occur in grassland soils regardless the soil history of manuring.

  6. Molecular identification and amphotericin B susceptibility testing of clinical isolates of Aspergillus from 11 hospitals in Korea.

    Science.gov (United States)

    Heo, Min Seok; Shin, Jong Hee; Choi, Min Ji; Park, Yeon Joon; Lee, Hye Soo; Koo, Sun Hoe; Lee, Won Gil; Kim, Soo Hyun; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook

    2015-11-01

    We investigated the species distribution and amphotericin B (AMB) susceptibility of Korean clinical Aspergillus isolates by using two Etests and the CLSI broth microdilution method. A total of 136 Aspergillus isolates obtained from 11 university hospitals were identified by sequencing the internal transcribed spacer (ITS) and β-tubulin genomic regions. Minimal inhibitory concentrations (MICs) of AMB were determined in Etests using Mueller-Hinton agar (Etest-MH) and RPMI agar (Etest-RPG), and categorical agreement with the CLSI method was assessed by using epidemiological cutoff values. ITS sequencing identified the following six Aspergillus species complexes: Aspergillus fumigatus (42.6% of the isolates), A. niger (23.5%), A. flavus (17.6%), A. terreus (11.0%), A. versicolor (4.4%), and A. ustus (0.7%). Cryptic species identifiable by β-tubulin sequencing accounted for 25.7% (35/136) of the isolates. Of all 136 isolates, 36 (26.5%) had AMB MICs of ≥2 μg/mL by the CLSI method. The categorical agreement of Etest-RPG with the CLSI method was 98% for the A. fumigatus, A. niger, and A. versicolor complexes, 87% for the A. terreus complex, and 37.5% for the A. flavus complex. That of Etest-MH was ≤75% for the A. niger, A. flavus, A. terreus, and A. versicolor complexes but was higher for the A. fumigatus complex (98.3%). Aspergillus species other than A. fumigatus constitute about 60% of clinical Aspergillus isolates, and reduced AMB susceptibility is common among clinical isolates of Aspergillus in Korea. Molecular identification and AMB susceptibility testing by Etest-RPG may be useful for characterizing Aspergillus isolates of clinical relevance.

  7. Candida Species Biofilms’ Antifungal Resistance

    Science.gov (United States)

    Silva, Sónia; Rodrigues, Célia F.; Araújo, Daniela; Rodrigues, Maria Elisa; Henriques, Mariana

    2017-01-01

    Candida infections (candidiasis) are the most prevalent opportunistic fungal infection on humans and, as such, a major public health problem. In recent decades, candidiasis has been associated to Candida species other than Candida albicans. Moreover, biofilms have been considered the most prevalent growth form of Candida cells and a strong causative agent of the intensification of antifungal resistance. As yet, no specific resistance factor has been identified as the sole responsible for the increased recalcitrance to antifungal agents exhibited by biofilms. Instead, biofilm antifungal resistance is a complex multifactorial phenomenon, which still remains to be fully elucidated and understood. The different mechanisms, which may be responsible for the intrinsic resistance of Candida species biofilms, include the high density of cells within the biofilm, the growth and nutrient limitation, the effects of the biofilm matrix, the presence of persister cells, the antifungal resistance gene expression and the increase of sterols on the membrane of biofilm cells. Thus, this review intends to provide information on the recent advances about Candida species biofilm antifungal resistance and its implication on intensification of the candidiasis. PMID:29371527

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

    Directory of Open Access Journals (Sweden)

    Jaime Niño

    2012-12-01

    Full Text Available 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

  9. Penetratin and derivatives acting as antifungal agents

    NARCIS (Netherlands)

    Masman, Marcelo F.; Rodriguez, Ana M.; Raimondi, Marcela; Zacchino, Susana A.; Luiten, Paul G. M.; Somlai, Csaba; Kortvelyesi, Tamas; Penke, Botond; Enriz, Ricardo D.

    The synthesis, in vitro evaluation, and conformational study of RQIKTWFQNRRMKWKK-NH(2) (penetratin) and related derivatives acting as antifungal agents are reported. Penetratin and some of its derivatives displayed antifungal activity against the human opportunistic pathogenic standardized ATCC

  10. SHORT COMMUNICATION EVALUATION OF ANTIFUNGAL AND ...

    African Journals Online (AJOL)

    Preferred Customer

    Pakistan) and chloramphenicol from Sigma St. Louis. (USA) was used as standard. Antifungal activity of monoesters. The antifungal activities of the monoesters (1-29) were determined by employing hanging drop method considering ketoconazole ...

  11. Development of laser beam welding transverse-varestraint test for assessment of solidification cracking susceptibility in laser welds

    Science.gov (United States)

    Chun, Eun-Joon; Baba, Hayato; Nishimoto, Kazutoshi; Saida, Kazuyoshi

    2015-05-01

    In order to quantitatively evaluate the solidification cracking susceptibility in laser welds of type 310S stainless steel, a transverse-Varestraint testing system using a laser beam welding apparatus was newly constructed. The timing-synchronization between the laser oscillator, welding robot and hydraulic pressure devices was established by employing high-speed camera observations together with electrical signal control among the three components. Moreover, the yoke-drop time measured by the camera was used to prevent underestimation of the crack length. The laser beam melt-run welding used a variable welding speed from 10.0 to 40.0 mm/s, while the gas tungsten arc welding varied the welding speed from 1.67 to 5.00 mm/s. As the welding speed increased from 1.67 to 40.0mm/s, the solidification brittle temperature range of type 310S stainless steel welds was reduced from 146 to 120 K. It follows that employing the laser beam welding process mitigates the solidification cracking susceptibility for type 310S stainless steel welds.

  12. Resistance to anti-tuberculosis drugs and practices in drug susceptibility testing in Moldova, 1995-1999.

    Science.gov (United States)

    Crudu, V; Arnadottir, Th; Laticevschi, D

    2003-04-01

    To evaluate practices in initial drug susceptibility testing (DST) in Moldova, anti-tuberculosis drug resist