Sample records for antifungal susceptibility testing

  1. Antifungal Susceptibility Testing of Ascomycetous Yeasts Isolated from Animals.

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


    Recent studies suggest that antifungal resistance in yeast isolates of veterinary origin may be an underdiagnosed threat. We tested a collection of 92 ascomycetous yeast isolates that were obtained in Spain from birds, mammals and insects for antifungal susceptibility. MICs to amphotericin B and azoles were low, and no resistant isolates were detected. Despite these results, and given the potential role of animals as reservoirs of resistant strains, continuous monitoring of antifungal susceptibility in the veterinary setting is recommended. PMID:27216048

  2. Evaluation of antifungal susceptibility testing in Candida isolates by Candifast and disk-diffusion method

    Sidhartha Giri; Anupma Jyoti Kindo


    With the increase in invasive fungal infections due to Candida species and resistance to antifungal therapy, in vitro antifungal susceptibility testing is becoming an important part of clinical microbiology laboratories. Along with broth microdilution and disk diffusion method, various commercial methods are being increasingly used for antifungal susceptibility testing, especially in the developed world. In our study, we compared the antifungal susceptibility patterns of 39 isolates of Candid...

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

    Song, You Bum; Suh, Moo Kyu; Ha, Gyoung Yim; Kim, Heesoo


    Background The necessity of performing antifungal susceptibility tests is recently increasing because of frequent cases of oral candidiasis caused by antifungal-resistant Candida species. The Etest (BioMerieux, Marcy l'Etoile, France) is a rapid and easy-to-perform in vitro antifungal susceptibility test. Objective The purpose of this study was to determine the minimal inhibitory concentrations (MICs) of antifungal agents by using the Etest for Candida species isolated from patients with oral...

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

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


    The broth macrodilution method (BMM) for antifungal susceptibility testing, approved by the National Committee for Clinical Laboratory Standards (NCCLS), was found to have deficiencies in testing of the antifungal activity of a new type of antifungal agent, a nonantibacterial chemically modified tetracycline (CMT-3). The high content of phosphate in the medium was found to greatly increase the MICs of CMT-3. To avoid the interference of phosphate in the test, a new method using potato dextros...

  5. In vitro susceptibility testing of Fonsecaea pedrosoi to antifungals

    BEDOUT Catalina de


    Full Text Available Based on the difficulties experienced in the treatment of chromoblastomycosis, 12 primary human isolates of F. pedrosoi, were tested for their in vitro susceptibility to various antimycotics. We adapted the recommendations of the NCCLS for yeasts and followed the indications for mold testing from other authors in order to determine their MIC?s and the MLC?s. It was found that a significant proportion of the isolates were resistant to 3 of the 4 antimycotics tested, as revealed by high MIC values, as follows: 33% were resistant to amphotericin B (AMB, 58.3% to 5 fluocytosine (5 FC and 66.7% to fluconazole (FLU. Contrarywise, none of the isolates proved resistant to itraconazole (ITZ. Determination of the MLC?s revealed that a larger proportion of the isolates were not killed by AMB, 5 FC (91.7%, FLU (100% or even, ITZ (41.7%. These data indicate that it would be desirable to determine the susceptibility of F. pedrosoi before initiating therapy, in order to choose the more effective antifungal and avoid clinical failure

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

    M.J. Najafzadeh


    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. Microdilution procedure for antifungal susceptibility testing of Paracoccidioides brasiliensis to amphotericin b and itraconazole

    E Takahagi-Nakaira


    Full Text Available In vitro tests employing microdilution to evaluate fungal susceptibility to antifungal drugs are already standardized for fermentative yeasts. However, studies on the susceptibility of dimorphic fungi such as Paracoccidioides brasiliensis employing this method are scarce. The present work introduced some modifications into antifungal susceptibility testing from the European Committee on Antimicrobial Susceptibility Testing (EUCAST, concerning broth medium and reading time, to determine minimal inhibitory concentration (MIC of amphotericin B and itraconazole against Paracoccidioides brasiliensis. Yeast-like cells of P. brasiliensis (Pb18 strain were tested for susceptibility to amphotericin B and itraconazole in RPMI 1640 medium, supplemented with 2% glucose and nitrogen source and incubated at 35°C. The MIC of amphotericin B and itraconazole against Pb18 were respectively 0.25 µg/mL and 0.002 µg/mL. The results of minimal fungicidal concentration (MFC showed that amphotericin B at 0.25 µg/mL or higher concentrations displayed fungicidal activity against Pb18 while itraconazole at least 0.002 µg/mL has a fungistatic effect on P. brasiliensis. In conclusion, our results showed that the method employed in the present study is reproducible and reliable for testing the susceptibility of P. brasiliensis to antifungal drugs.

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

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


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

    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. Five hundred nail samples of Indian patients clinically suspected of onychomycosis were subjected to direct microscopy and fungal culture. Representative Fusarium isolates were further identified to species level by multi-locus sequencing for internal transcribed spacer, translation elongation factor 1 alpha (tef1-α) and RNA polymerase II subunit (rpb2) regions (primer pairs: ITS1/ITS4, EF1/EF2, 5f2/7cr, respectively). These representative strains were also tested for in vitro antifungal susceptibility by the broth microdilution method. Members of the genus Fusarium proved to be the most common NDM responsible for onychomycosis. The Fusarium spp. responsible for onychomycosis belonged to the Fusarium solani species complex (F. keratoplasticum and F. falciforme) and Fusarium fujikuroi species complex (F. proliferatum, F. acutatum and F. sacchari). Antifungal susceptibility results indicated that amphotericin B was the most effective antifungal across all isolates (MIC ranging 0.5-2 mg/L), followed by voriconazole (MIC ranging 1-8 µg/ml). However, a large variation was shown in susceptibility to posaconazole (MIC ranging 0.5 to >16 µg/ml). To conclude, we identified different Fusarium spp. responsible for onychomycosis in India with variation within species in susceptibility to antifungal agents, showing that fusariosis requires correct and prompt diagnosis as well as antifungal susceptibility testing. PMID:27138574

  10. Multilaboratory Evaluation of In Vitro Antifungal Susceptibility Testing of Dermatophytes for ME1111.

    Ghannoum, M; Chaturvedi, V; Diekema, D; Ostrosky-Zeichner, L; Rennie, R; Walsh, T; Wengenack, N; Fothergill, A; Wiederhold, N


    ME1111 is a novel small molecule antifungal agent under development for the topical treatment of onychomycosis. Standardization of the susceptibility testing method for this candidate antifungal is needed. Toward this end, 8 independent laboratories determined the interlaboratory reproducibility of ME1111 susceptibility testing. In addition, we subsequently identified 2 strains as quality control (QC) isolates for the method. In the reproducibility study, 5 blinded clinical strains each of Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum were tested, while the QC study tested 6 blinded T. rubrum or T. mentagrophytes ATCC strains. Testing was performed in frozen microtiter panels according to the Clinical and Laboratory Standards Institute (CLSI) M38-A2 methodology. In the reproducibility study, 9 of 15 clinical strains showed interlaboratory agreement of >90% at the 80% inhibition endpoint, with a range of agreement of 76.2% to 100%. In the QC study, 4 of the 6 ATCC strains showed interlaboratory agreement of >90%. ME1111 demonstrated excellent interlaboratory agreement when tested against dermatophytes. Based on this data, the CLSI Subcommittee on Antifungal Susceptibility Tests approved the susceptibility testing of ME1111 against dermatophytes according to M38-A2 methodology, which stipulates RPMI 1640 as the test medium, an inoculum size of 1 to 3 × 10(3) CFU/ml, and an incubation time and temperature of 96 h at 35°C. The MIC endpoint should be 80% inhibition compared with the growth control. T. rubrum ATCC MYA-4438 and T. mentagrophytes ATCC 28185 were selected as QC isolates, with an acceptable range of 0.12 to 1 μg/ml for the two strains. PMID:26719434

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

    Mahmoudi Rad M


    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

  12. Use of the Sensititre Colorimetric Microdilution Panel for Antifungal Susceptibility Testing of Dermatophytes

    Pujol, I.; Capilla, J.; Fernández-Torres, B.; Ortoneda, M.; Guarro, J.


    The Sensititre YeastOne antifungal panel was used to test 49 dermatophytes belonging to the species Epidermophyton floccosum, Microsporum gypseum, Microsporum canis, Trichophyton tonsurans, Trichophyton rubrum, and Trichophyton mentagrophytes. The MICs of four antifungals obtained with the Sensititre YeastOne antifungal panel were compared with those obtained by the reference NCCLS microdilution method. The levels of agreement between the two methods (≤2 dilutions) were 81.6% with amphoterici...

  13. Antifungal Susceptibility Testing to Determine MIC of Amphotericine B, Fluconazole and Ketoconazole against Ocular Fungal Infection

    Mitesh H. Patel, Avani M. Patel, Sachin M. Patel, Govind L Ninama, Kamlesh R. Patel, Bharti C. Lavingia


    Full Text Available Purpose: To standardize In-vitro antifungal susceptibility testing by agar dilution method to find out minimum inhibitory concentration (MIC of Amphotericine B, fluconazole and ketoconazole against ocular fungal isolates. Methods: A total of 90 isolates (25 yeast & 65 filamentous fungi were included. The drugs were added in serial double dilution in medium containing yeast nitrogen base. The MIC was determined by inhibition of visible growth on lowest concentration of drug containing media as comparing with visible growth on drug free media. Results: Out of 25 yeast isolate, all are sensitive to Amphotericine B, 8 % & 12 % are resistant to Fluconazole & ketoconazole respectively. Out of 65 Filamentous fungi, 3 %, 20 % & 28 % are resistant to Amphotericin B, Fluconazole & Ketoconazole respectively. Conclusion: The methodology used in study is user’s friendly, reliable & cost effective.

  14. Susceptibility of Clinical Candida Species Isolates to Antifungal Agents by E-Test, Southern Iran: A Five Year Study

    A Alborzi


    Full Text Available Background and Objectives: The incidence of fungal infections in immunocompromised patients, especially by Candida species, has increased in recent years. This study was designed to identify Candida species and determine antifungal susceptibility patterns of 595 yeast strains isolated from various clinical specimens.Material and Methods: Identification of the isolates were determined by the API 20 C AUX kit and antifungal susceptibilities of the species to fluconazole, amphotericin B, ketoconazole, itraconazole, voriconazole, and caspofungin were determined by the agar-based E-test method.Results: Candida albicans (48% was the most frequently isolated species, followed by Candida kruzei (16.1%, Candida glabrata (13.5%, Candida kefyr (7.4%, Candida parapsilosis (4.8%, Candida tropicalis (1.7% and other species (8.5%. Resistance varies depending on the species and the respective antifungal agents. Comparing the MIC90 for all the strains, the lower MIC90 was observed for caspofungin (0.5 μg/ml. The MIC90 for all Candida species were 64 μg/ml for fluconazole, 0.75 μg/ml for amphotericin B, 4 μg/ml for ketoconazole, 4 μg/ml for itraconazole, and 2 μg/ml for voriconazole.Conclusions: Species definition and determination of antifungal susceptibility patterns are advised for the proper management and treatment of patients at risk for systemic candidiasis. Resistance to antifungal agents is an alarming sign for the emerging common nosocomial fungal infections.

  15. Comparative Evaluation of FUNGITEST and Broth Microdilution Methods for Antifungal Drug Susceptibility Testing of Candida Species and Cryptococcus neoformans

    Davey, Kate G.; Holmes, Ann D.; Elizabeth M. Johnson; Szekely, Adrien; Warnock, David W.


    The FUNGITEST method (Sanofi Diagnostics Pasteur, Paris, France) is a microplate-based procedure for the breakpoint testing of six antifungal agents (amphotericin B, flucytosine, fluconazole, itraconazole, ketoconazole, and miconazole). We compared the FUNGITEST method with a broth microdilution test, performed according to National Committee for Clinical Laboratory Standards document M27-A guidelines, for determining the in vitro susceptibilities of 180 isolates of Candida spp. (50 C. albica...

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

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


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

  17. Role of Antifungal Susceptibility Testing in Non-Aspergillus Invasive Mold Infections.

    Lamoth, Frédéric; Damonti, Lauro; Alexander, Barbara D


    No clinical breakpoints are available to delineate antifungal drug efficacy in non-Aspergillus invasive mold infections (NAIMIs). In this analysis of 39 NAIMI episodes, the MIC of the first-line antifungal drug was the most important predictor of therapeutic response. For amphotericin B, an MIC of ≤0.5 μg/ml was significantly associated with better 6-week outcomes. PMID:27008871

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

    Esther Manso


    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.

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

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


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

  20. Antifungal Susceptibility Testing of Dermatophytes: Establishing a Medium for Inducing Conidial Growth and Evaluation of Susceptibility of Clinical Isolates

    Jessup, C. J.; Warner, J.; Isham, N.; Hasan, I.; Ghannoum, M. A.


    A standardized reference method for dermatophyte in vitro susceptibility testing is lacking. In a previous study, Norris et al. (H. A. Norris, B. E. Elewski, and M. A. Ghannoum, J. Am. Acad. Dermatol. 40(6, part 2):S9–S13) established the optimal medium and other growth variables. However, the earlier study did not address two issues: (i) selection of an optimal medium for conidial formation by dermatophytes and (ii) validation of the method with a large number of dermatophytes. The present s...

  1. Susceptibility Testing

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

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

    Esther Manso


    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.

  3. Genetic diversity of Aspergillus species isolated from onychomycosis and Aspergillus hongkongensis sp. nov., with implications to antifungal susceptibility testing.

    Tsang, Chi-Ching; Hui, Teresa W S; Lee, Kim-Chung; Chen, Jonathan H K; Ngan, Antonio H Y; Tam, Emily W T; Chan, Jasper F W; Wu, Andrea L; Cheung, Mei; Tse, Brian P H; Wu, Alan K L; Lai, Christopher K C; Tsang, Dominic N C; Que, Tak-Lun; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y


    Thirteen Aspergillus isolates recovered from nails of 13 patients (fingernails, n=2; toenails, n=11) with onychomycosis were characterized. Twelve strains were identified by multilocus sequencing as Aspergillus spp. (Aspergillus sydowii [n=4], Aspergillus welwitschiae [n=3], Aspergillus terreus [n=2], Aspergillus flavus [n=1], Aspergillus tubingensis [n=1], and Aspergillus unguis [n=1]). Isolates of A. terreus, A. flavus, and A. unguis were also identifiable by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The 13th isolate (HKU49(T)) possessed unique morphological characteristics different from other Aspergillus spp. Molecular characterization also unambiguously showed that HKU49(T) was distinct from other Aspergillus spp. We propose the novel species Aspergillus hongkongensis to describe this previously unknown fungus. Antifungal susceptibility testing showed most Aspergillus isolates had low MICs against itraconazole and voriconazole, but all Aspergillus isolates had high MICs against fluconazole. A diverse spectrum of Aspergillus species is associated with onychomycosis. Itraconazole and voriconazole are probably better drug options for Aspergillus onychomycosis. PMID:26658315

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

    Vera Lucia Degaspare Monte Mascaro


    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

  5. Standardization of Antifungal Susceptibility Variables for a Semiautomated Methodology

    Rodríguez-Tudela, Juan L.; Cuenca-Estrella, Manuel; Díaz-Guerra, Teresa M.; Mellado, Emilia


    Recently, the methodology that will serve as a basis of the standard for antifungal susceptibility testing of fermentative yeasts of the European Committee on Antibiotic Susceptibility Testing has been described. This procedure employs a spectrophotometric method for both inoculum adjustment and endpoint determination. However, the utilization of a spectrophotometer requires studies for standardization. The present work analyzes the following parameters: (i) accuracy of inoculum preparation, ...

  6. Antifungal Susceptibilities of Cryptococcus neoformans

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


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

  7. Optimization and Isolation of Dermatophytes from Clinical Samples and In Vitro Antifungal Susceptibility Testing By Disc Diffusion Method

    Amodkumar Yadav


    Full Text Available India is a large subcontinent with remarkably varied topography, situated within the tropical and subtropical belts of the world. In the study patients with Tinea infections were examined clinically by dermatologist. Isolation, confirmatory test were done as per the standard procedure, and Antifungal Susceptibility test was done by Disc diffusion method.Other conditions such as seborrheic dermatitis, psoriasis, alopecia areata, folliculitis and pseudopelade may mimic ringworm of head and other tinea must be identified. A total of sixty six patients of dermatophytosis were studied. Males were predominantly affected 51 (77% cases as compared to females15 (23% cases. Male to female ratio was 3.4:1. Most common age group affected was 21-30 years with 20 cases (23%. Least common age group affected was 61-70 years with 3 cases (4%.Tinea corporis was more common in the age group 21-30 years with 13 cases (37.14% and in males with 29 cases (82.85% than females with 6 cases (17.15%.Tinea unguium was more common in the age group of 31-40 years with 6 cases (37.5% and in males with 10 cases (62.5% than females with 6 cases (37.5%.Tinea cruris was more common in the age group 51-60 years with 2 cases (40% and was more common in males with 5 cases (100%.In tinea pedis, one case was seen in the age group of 11-20 years and the other in the age group of 41-50 and 51-60 years, and was more common in males with 3 cases (100%.Tinea barbae was more common in the age group 21-30 years with 2 cases (66.66% .Tinea capitis was more common in the age group of 31-40 years with 2 cases (66.66% and was more common in females with 3 cases (100%. Tinea manuum was more common in the age group of 31-40 years and in males with 1 case (100%. In males, commonest infection was T. corporis while in female commonest infection was T.corporis.rate of direct microscopy and culture (78.79%. About 89.47% of the dermatophytes grew faster in DTM with compare to SDA, so the growth rate of

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

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


    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. PMID:26933207

  9. Taxonomy and antifungal susceptibility of clinically important Rasamsonia species

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


    set of Rasamsonia argillacea strains, including 28 clinical strains, was studied, and antifungal susceptibility profiles were generated. Data obtained from morphological studies and from phylogenetic analyses of internal transcribed spacer (ITS) and partial _-tubulin and calmodulin sequences revealed...... recently reported clinical isolates from animal or human patients. Susceptibility tests showed that the antifungal susceptibility profiles of the four members of the R. argillacea complex are similar, and caspofungin showed significant activity in vitro, followed by amphotericin B and posaconazole...


    Geeta M Vaghela


    Full Text Available Introduction: The increase in candidaemia is associated with high mortality. A shift has been observed in the relative frequency of each Candida spp. isolated from blood. Options of the antifungal drugs available for treatment of systemic and invasive candidiasis are restricted to polyenes, allylamines, azoles and recently developed echinocandin class of molecules. A rise in the incidence of antifungal resistance to Candida spp. has also been reported over the past decade. Studies on prevalence of infections and antifungal susceptibility testing are useful in deciding clinical strategies. Aims: To do species level identification and detect resistance, if any, among Indian clinical isolates of C. albicans. Methodology: From total 135 patients from a tertiary care hospital of Gujarat, Candida species were isolated from different clinical specimens. The growth of Candida on Sabouraud's dextrose agar was confirmed by Gram staining in which gram positive budding fungal cells were observed. Then its growth was examined for colony morphology on Sabouraud's dextrose agar and chlamydospore production on Corn meal tween 80 agar. Germ tube tests and other biochemical tests like sugar fermentation, sugar assimilation and urease test were performed to identify the species of Candida. Antifungal susceptibility testing was performed by NCCLS M44-A Disc diffusion method. Results: Out of total 135 samples, C. Albicans were isolated from 52 (38.5%. Among Non Albican Candid (NAC, Candida glabrata was 36 (26.7% followed by Candida tropicalis 25(18.5%. C. albicans was found resistant to Fluconazole, Itraconazole and Amphotericine B in 3.8%, 3.8% and 1.9% cases respectively. For NAC, resistance of Fluconazole, Itraconazole and Amphotericine B was found in 4.8%, 3.6% and 2.4% cases respectively. [Natl J Med Res 2015; 5(2.000: 122-126

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

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


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

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

    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.

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

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


    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. PMID:25168965

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

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


    Cryptococcosis is mainly caused by members of the Cryptococcus gattii/Cryptococcus neoformans species complexes. Here, we report the molecular characterisation and in vitro antifungal susceptibility of Danish clinical cryptococcal isolates. Species, genotype, serotype and mating type were determined by amplified fragment length polymorphism (AFLP) fingerprinting and qPCR. EUCAST E.Def 7.2 MICs were determined for amphotericin B, flucytosine, fluconazole, voriconazole and isavuconazole. Most isolates were C. neoformans (serotype A; n = 66) and belonged to genotype AFLP1/VNI (n = 61) or AFLP1B/VNII (n = 5) followed by Cryptococcus deneoformans (serotype D; genotype AFLP2, n = 20), C. neoformans × C. deneoformans hybrids (serotype AD; genotype AFLP3, n = 13) and Cryptococcus curvatus (n = 2). Six isolates were C. gattii sensu lato, and one isolate was a C. deneoformans × C. gattii hybrid (genotype AFLP8). All isolates were amphotericin B susceptible. Flucytosine susceptibility was uniform MIC50 of 4-8 mg l(-1) except for C. curvatus (MICs >32 mg l(-1) ). Cryptococcus gattii sensu lato isolates were somewhat less susceptible to the azoles. MICs of fluconazole (>32 mg l(-1) ), voriconazole (≥0.5 mg l(-1) ) and isavuconazole (0.06 and 0.25 mg l(-1) respectively) were elevated compared to the wild-type population for 1/19 C. deneoformans and 1/2 C. curvatus isolates. Flucytosine MIC was elevated for 1/61 C. neoformans (>32 mg l(-1) ). Antifungal susceptibility revealed species-specific differential susceptibility, but suggested acquired resistance was an infrequent phenomenon. PMID:27061834

  15. 卢立康唑醇质体体外抗真菌活性研究%The antifungal susceptibility test in vitro of luliconazole ethosomes

    樊建峰; 林碧雯; 李恒进


    Objective To study antifungal susceptibility of luliconazole ethosomes in vitro .Methods In vitro ,antifungal activity of luliconazole ethosome,liposome,hydroalcoholic solution:MICs were determined using the micro-broth dilution as-say.Results The MIC of the luliconazole ethosome was lower than that of liposome form or hydroalcoholic solution form.The MIC of luliconazole ethosome to Trichophyton spp.was lower than the sensitive degree to Candida spp.Conclusions In vitro ,the antifungal effect of luliconazole ethosome is better than luliconazole liposome or its hydroalcoholic solution.%目的:检测卢立康唑醇质体体外抗菌活性。方法采用微量液基稀释法检测卢立康唑醇质体、脂质体、45%水醇溶液对皮肤癣菌、念珠菌的体外抗菌活性。结果卢立康唑醇质体对皮肤癣菌及念珠菌的 MIC 值低于脂质体及水醇溶液,且对毛癣菌属较念珠菌属的 MIC 值更低。结论卢立康唑醇质体的体外抗菌性能优于脂质体及水醇溶液。

  16. Molecular identification and antifungal susceptibility of 186 Candida isolates from vulvovaginal candidiasis in southern China.

    Shi, Xiao-Yu; Yang, Yan-Ping; Zhang, Ying; Li, Wen; Wang, Jie-Di; Huang, Wen-Ming; Fan, Yi-Ming


    There is limited information regarding the molecular epidemiology and antifungal susceptibilities of Candida isolates using the Neo-Sensitabs method in patients with vulvovaginal candidiasis (VVC). From August 2012 to March 2013, 301 non-pregnant patients aged 18-50 years with suspected VVC were prospectively screened at a teaching hospital in southern China. The vaginal isolates were identified by DNA sequencing of internal transcribed spacer and the D1/D2 domain. Antifungal susceptibility testing of seven antifungal agents was performed using the Neo-Sensitabs tablet diffusion method. Candida species were isolated from 186 cases (61.79 %). The most common pathogen was Candida albicans (91.4 %), followed by Candida glabrata (4.3 %), Candida tropicalis (3.2 %) and Candida parapsilosis (1.1 %). The susceptibility rates to C. albicans were higher for caspofungin, voriconazole and fluconazole than those for itraconazole, miconazole, ketoconazole and terbinafine (Ptreatment of VVC. PMID:25596116

  17. Standardization of antifungal susceptibility variables for a semiautomated methodology.

    Rodríguez-Tudela, J L; Cuenca-Estrella, M; Díaz-Guerra, T M; Mellado, E


    Recently, the methodology that will serve as a basis of the standard for antifungal susceptibility testing of fermentative yeasts of the European Committee on Antibiotic Susceptibility Testing has been described. This procedure employs a spectrophotometric method for both inoculum adjustment and endpoint determination. However, the utilization of a spectrophotometer requires studies for standardization. The present work analyzes the following parameters: (i) accuracy of inoculum preparation, (ii) correlation between optical density and CFU per milliliter, (iii) influence of the wavelength on the endpoint determination, and (iv) influence of the dimethyl sulfoxide concentration on the growth kinetics. The main results can be summarized as follows: (i) inoculum preparation following the methodology recommended by the National Committee for Clinical Laboratory Standards is an exact procedure; (ii) the relationship between optical density and CFU per milliliter is linear (coefficient of determination, r(2) = 0.84); (iii) MICs obtained by means of spectrophotometric readings at different wavelengths are identical (for amphotericin B, an intraclass correlation coefficient of 0.98 was obtained; for fluconazole, the intraclass correlation coefficient was 1); and (iv) a 2% concentration of dimethyl sulfoxide produces a significantly slower and lower growth curve of Candida spp. than other concentrations. PMID:11427562

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

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


    Vulvovaginal candidiasis is one of the most common mycosis. However, the information about antifungal susceptibilities of the yeasts causing this infection is scant. We studied 121 yeasts isolated from 118 patients with vulvovaginal candidiasis. The isolates were identified by phenotypic and molecular methods, including four phenotypic methods described to differentiate Candida albicans from C. dubliniensis. Antifungal susceptibility testing was performed according to CLSI documents M27A3 and M27S4 using the drugs available as treatment option in the hospital. Diabetes, any antibacterial and amoxicillin treatment were statistically linked with vulvovaginal candidiasis, while oral contraceptives were not considered a risk factor. Previous azole-based over-the-counter antifungal treatment was statistically associated with non-C.albicans yeasts infections. The most common isolated yeast species was C. albicans (85.2 %) followed by C. glabrata (5 %), Saccharomyces cerevisiae (3.3 %), and C. dubliniensis (2.5 %). Fluconazole- and itraconazole-reduced susceptibility was observed in ten and in only one C. albicans strains, respectively. All the C. glabrata isolates showed low fluconazole MICs. Clotrimazole showed excellent potency against all but seven isolates (three C. glabrata, two S. cerevisiae, one C. albicans and one Picchia anomala). Any of the strains showed nystatin reduced susceptibility. On the other hand, terbinafine was the less potent drug. Antifungal resistance is still a rare phenomenon supporting the use of azole antifungals as empirical treatment of vulvovaginal candidiasis. PMID:25005365

  19. Antifungal susceptibility and virulence factors of clinically isolated dermatophytes in Tehran, Iran

    Mohammad Ali Afshari


    Full Text Available Background and Objectives: Dermatophytes possess a wide array of virulence factors and various antifungal susceptibility patterns which influence their pathogenesis in humans and animals. The aim of this study was to evaluate antifungal suscep- tibility and keratinase and proteinase activity of 49 dermatophyte strains from the genera Microsporum, Trichophyton and Epidermophyton which were isolated from human cases of dermatophytosis.Materials and Methods: Forty-nine dermatophyte strains isolated from clinical samples were cultured on general and spe- cific culture media. Keratinase and proteinase activity was screened on solid mineral media and confirmed in liquid cultures. Drug susceptibility toward azoles (fluconazole, ketoconazole and itraconazole, griseofulvin and terbinafine was evaluated using disk diffusion method on Mueller-Hinton agar and minimum inhibitory concentrations (MICs were determined using microbroth dilution assay according to the Clinical and Laboratory Standards Institute (CLSI guidelines.Results: Our results indicated that clinically isolated dermatophytes from 7 major species produced keratinase and protein- ase at different extents. The mean keratinase and proteinase activity was reported as 6.69 ± 0.31 (U/ml and 2.10 ± 0.22 (U/ ml respectively. Disk diffusion and microbroth dilution (MIC results of antifungal susceptibility testing showed that ke- toconazole was the most effective drug against Epidermophyton floccosum and Trichophyton mentagrophytes, itraconazole against T. rubrum and E. floccosum, and griseofulvin and terbinafine against Trichophyton verrucosum. Our results showed that all dermatophyte isolates were resistant to fluconazole. Overall, ketoconazole and itraconazole were the most effective drugs for all dermatophyte species tested.Conclusion: Our results showed that antifungal susceptibility testing is an urgent need to select drugs of choice for treatment of different types of dermatophytosis and




    Full Text Available ACT: Candida , a yeast like ubiquitous fungus , is an endogenous species which produces commonest fungal infection; Candidiasis. Resistance to antifungal agents is an alarming sign for the emerging common nosocomial candidiasis. MATERIALS AND METHODS: Various types of specimens we re collected from the c linically suspected cases of candidiasis. Isolation and characterization of candida sp . was done by standard procedures. Antifungal susceptibility was done by disc diffusion method. RESULT: The candida was isolated from various clinical specimens , vaginal swab (24.66% , skin scraping (13.33% oral swabs (12.66% , ear swabs ( 11.33% , nail scraping (10% , and pus from diabetes foot ulcer and post - operative wound infection ( 8% , sputum ( 6% , urine (4.66% , stool ( 4% , blood ( 2.66% , and eye swabs ( 2.66%. Amon g different species of candida isolated C.albicans was the predominant species (79.33% followed by C tropicalis (19.33% and C.Guilliermondii (1.33%. Antifungal resistance of different species of candida was higher to fluconazole . The least resistance wa s seen with amphotericin - B (1.33%. CONCLUSION: The increased isolation of candida species and development of resistance to commonly used antifungal drugs requires careful interpretation and the in vitro susceptibility testing. This facilitates better pat ient care.


    Crina Saviuc


    Full Text Available The use of natural antifungal compounds has become a viable alternative for fighting fungal infections since high rates of resistance to synthetic antifungal compounds has emerged. Classical techniques aimed to routinely investigate fungal susceptibility are often limited when using natural essential oils, because of their instability and great volatility that may lead to false results. In this study, we report the results obtained by classical antimicrobial susceptibility testing techniques and flow cytometry regarding the effect of some volatile oils on different Candida clinical isolates. The obtained results revealed that flow cytometry is a very useful and precise technique in investigating the influence of essential oils on the fungal cells, surpassing the disadvantage of their volatility and thus reducing false results often obtained by using the classical methods.

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

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


    Background: Vulvovaginal candidiasis (VVC) was a common infection associated with lifelong harassment of woman's social and sexual life. The purpose of this study was to describe the species distribution and in vitro antifungal susceptibility of Candida species (Candida spp.) isolated from patients with VVC over 8 years. Methods: Species which isolated from patients with VVC in Peking University First Hospital were identified using chromogenic culture media. Susceptibility to common antifungal agents was determined using agar diffusion method based on CLSI M44-A2 document. SPSS software (version 14.0, Inc., Chicago, IL, USA) was used for statistical analysis, involving statistical description and Chi-square test. Results: The most common strains were Candida (C.) albicans, 80.5% (n = 1775) followed by C. glabrata, 18.1% (n = 400). Nystatin exhibited excellent activity against all species (treatment of VVC at present. The species distribution and in vitro antifungal susceptibility of Candida spp. isolated from patients with VVC had changed over time. PMID:27174323

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

    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

  4. In vitro susceptibility testing of Candida and Aspergillus spp. to voriconazole and other antifungal agents using Etest: results of a French multicentre study.

    Mallié, M; Bastide, J M; Blancard, A; Bonnin, A; Bretagne, S; Cambon, M; Chandenier, J; Chauveau, V; Couprie, B; Datry, A; Feuilhade, M; Grillot, R; Guiguen, C; Lavarde, V; Letscher, V; Linas, M D; Michel, A; Morin, O; Paugam, A; Piens, M A; Raberin, H; Tissot, E; Toubas, D; Wade, A


    Minimum inhibitory concentrations (MICs) of the antifungal agent voriconazole were determined using the Etest and compared with those of amphotericin B, itraconazole and fluconazole using 1986 clinical isolates of Candida spp. Voriconazole MICs were also compared with those of amphotericin B and itraconazole using 391 clinical isolates of Aspergillus spp. Voriconazole was found to have more potent activity and lower MIC values than amphotericin B, itraconazole and fluconazole against C. albicans, C. tropicalis, C. parapsilosis and C. kefyr. Against C. glabrata and C. krusei, voriconazole was more active than either of the other two azole antifungals but had similar activity to amphotericin B. For species of Aspergillus, MIC values of voriconazole were lower than those of amphotericin B and itraconazole against A. fumigatus and A. flavus, and were similar to those of amphotericin B against A. niger. Against A. terreus, MIC values for voriconazole and itraconazole were similar. A. terreus is known to be resistant to amphotericin B, and this was reflected in higher MIC values compared with those of voriconazole and itraconazole. Voriconazole therefore compares very favourably with other antifungal agents against a large number of clinical isolates of Candida and Aspergillus spp. PMID:15784312

  5. In vitro resistance of clinical Fusarium species to amphotericin B and voriconazole using the EUCAST antifungal susceptibility method.

    Taj-Aldeen, Saad J; Salah, Husam; Al-Hatmi, Abdullah M S; Hamed, Manal; Theelen, Bart; van Diepeningen, Anne D; Boekhout, Teun; Lass-Flörl, Cornelia


    Susceptibility testing using the EUCAST-AFST method against 39 clinical Fusarium strains consecutively collected from local and invasive infections during the last 10years assessed the in vitro activities of amphotericin B (AmB) and triazole antifungal agents. In addition, the susceptibility pattern of 12 reference strains from the CBS-KNAW Fungal Biodiversity Centre (CBS) was evaluated. In particular Fusarium petroliphilum and F. solani sensu lato were involved in disseminated infections and known for treatment failure. AmB displayed the lowest MICs followed by voriconazole VRC, posaconazole (POC). Itraconazole (ITC) showed high MIC values, displaying in vitro resistance. Clinical isolates were significantly (P antifungal therapy. Resistant profiles to AmB and VRC, which are the currently recommended agents in the guidelines for treatments, and a late diagnosis may be associated with high mortality rate in immunocompromised patients. The present antifungal susceptibility profiles showed that species- and strain-specific differences in antifungal susceptibility exist within Fusarium and that susceptibility testing is important and may improve the prognosis of these infections. PMID:27312690

  6. Diversity of Bipolaris species in clinical samples in the United States and their antifungal susceptibility profiles.

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


    A set of 104 isolates from human clinical samples from the United States, morphologically compatible with Bipolaris, were morphologically and molecularly identified through the sequence analysis of the internal transcribed space (ITS) region of the nuclear ribosomal DNA (rDNA). The predominant species was Bipolaris spicifera (67.3%), followed by B. hawaiiensis (18.2%), B. cynodontis (8.6%), B. micropus (2.9%), B. australiensis (2%), and B. setariae (1%). Bipolaris cynodontis, B. micropus, and B. setariae represent new records from clinical samples. The most common anatomical sites where isolates were recovered were the nasal region (30.7%), skin (19.2%), lungs (14.4%), and eyes (12.5%). The antifungal susceptibilities of 5 species of Bipolaris to 9 drugs are provided. With the exception of fluconazole and flucytosine, the antifungals tested showed good activity. PMID:23052310

  7. Antifungal susceptibility testing of isolates from a randomized, multicenter trial of fluconazole versus amphotericin B as treatment of nonneutropenic patients with candidemia. NIAID Mycoses Study Group and the Candidemia Study Group.

    Rex, J. H.; Pfaller, M. A.; Barry, A L; Nelson, P W; Webb, C. D.


    The antifungal susceptibilities of 232 pathogenic blood stream Candida isolates collected during a recently completed trial comparing fluconazole (400 mg/day) with amphotericin B (0.5 mg/kg of body weight per day) as treatment for candidemia in the nonneutropenic patient were determined both by the National committee for Clinical Laboratory Standards M27-P macrobroth methodology and by a less cumbersome broth microdilution methodology. For amphotericin B, M27-P yielded a very narrow range of ...

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

    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


    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. PMID:26591009

  9. Prevalence of Candida Infection and its Antifungal Susceptibility Pattern in Tertiary Care Hospital, Ahmedabad

    Lata R Patel


    Full Text Available Introduction: In the past three decades with the use of potent antibacterial immunosuppressive and cytotoxic drugs, lethal invasive candidiasis has been described with increasing frequency. Patients admitted at tertiary care hospitals have access to very intensive management modalities. This, along with increasing number of immune-compromised patients, has lead to rise in infections caused by candida especially by NCA (Non Candida Albicans. Methodology: Duration of the study was from 1st July- 2011 to 30th June 2012. Candida species isolated from various clinical specimens were subjected to speciation using standard yeast identification protocol and CHROM agar. Antifungal susceptibility testing was done by the disc diffusion method against Amphotericin B and Azole group of antifungals like Fluconazole, Itraconazole, Clotrimazole and Voriconazole. Results: Among the 430 culture positive isolates 161(37.4% were C. albicans and 269 (62.6% were non candida albicans. Among NCA, 176(40.9% were C. tropicalis followed by other species. Susceptibility pattern showed that Azole group 25.5% sensitive among C. albicans and 18.7% sensitive among C. tropicalis while in Amphotericin B sensitivity varies from 75.6% to 100% to all isolated spp. of candida. Conclusion: In this study C. tropicalis was the most common yeast isolated from all the clinical samples. The C. albicans and NCA showed highly susceptible to Amphotericin B, followed by Voriconazole & Clotrimazole, is the drug of choice. [Natl J of Med Res 2012; 2(4.000: 439-441

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

    Maria Helena Galdino Figueiredo-Carvalho


    Full Text Available This study evaluated the antifungal susceptibility profile and the production of potential virulence attributes in a clinical strain of Candida nivariensis for the first time in Brazil, as identified by sequencing the internal transcribed spacer (ITS1-5.8S-ITS2 region and D1/D2 domains of the 28S of the rDNA. For comparative purposes, tests were also performed with reference strains. All strains presented low planktonic minimal inhibitory concentrations (PMICs to amphotericin B (AMB, caspofungin (CAS, and voriconazole. However, our strain showed elevated planktonic MICs to posaconazole (POS and itraconazole, in addition to fluconazole resistance. Adherence to inert surfaces was conducted onto glass and polystyrene. The biofilm formation and antifungal susceptibility on biofilm-growing cells were evaluated by crystal violet staining and a XTT reduction assay. All fungal strains were able to bind both tested surfaces and form biofilm, with a binding preference to polystyrene (p < 0.001. AMB promoted significant reductions (≈50% in biofilm production by our C. nivariensis strain using both methodologies. This reduction was also observed for CAS and POS, but only in the XTT assay. All strains were excellent protease producers and moderate phytase producers, but lipases were not detected. This study reinforces the pathogenic potential of C. nivariensis and its possible resistance profile to the azolic drugs generally used for candidiasis management.

  11. First case of Tritirachium oryzae as agent of onychomycosis and its susceptibility to antifungal drugs.

    Naseri, Ali; Fata, Abdolmajid; Najafzadeh, Mohammad Javad


    The first case of Tritirachium oryzae isolated from an Iranian patient is reported. A 44-year-old woman with a lesion in her fingernail was examined for onychomycosis. Direct microscopic examination of the nail clippings revealed fungal filaments and inoculation of portions of the nail clippings on cultures media yielded T. oryzae after 8 days. The isolate was identified as Tritirachium spp. on the basis of gross morphological characteristics of the fungal colony and microscopic characterization of slide cultures. The diagnosis of T. oryzae was confirmed by PCR sequencing of the internal transcribed spacer domain of the rDNA gene. In vitro antifungal susceptibility test demonstrated that the fungus was susceptible to itraconazole and posaconazole. The patient was treated with oral itraconazole. PMID:23591624

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

    Fábio Silvestre Ataides


    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.

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

    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)

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

    Mohammadi, R; Ataei, B


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

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

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


    Bloodstream infections caused by Candida species are of increasing importance and associated with significant mortality. We performed a multi-centre prospective observational study to identify the species and antifungal susceptibilities of invasive bloodstream isolates of Candida species in the Asia-Pacific region. The study was carried out over a two year period, involving 13 centers from Brunei, Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam. Identification of Candida species was performed at each study center, and reconfirmed at a central laboratory. Susceptibility testing was performed using a commercial broth dilution panel (Sensititre YeastOne YST-010, Thermofisher, United Kingdom) with susceptibility categorisation (S = susceptible, S-DD = susceptible dose-dependent) applied using breakpoints from the Clinical Laboratory Standards Institute. Eight hundred and sixty-one Candida isolates were included in the study. The most common species were C. albicans (35.9%), C. tropicalis (30.7%), C. parapsilosis (15.7%), and C. glabrata (13.6%). Non-albicans species exceeded C. albicans species in centers from all countries except Taiwan. Fluconazole susceptibility was almost universal for C. albicans (S = 99.7%) but lower for C. tropicalis (S = 75.8%, S-DD = 6.1%), C. glabrata (S-DD = 94.9%), and C. parapsilosis (S = 94.8%). Echinocandins demonstrated high rates of in vitro susceptibility (S>99%) against C. albicans, C. tropicalis, and C. parapsilosis This study demonstrates that non-albicans species are the most common isolates from bloodstream infections in most countries in the Asia-Pacific region, with C. tropicalis as the predominant species. Because of the prevalence of reduced susceptibility to fluconazole in non-albicans species, the study indicates that echinocandins should be the antifungal of choice in clinically unstable or high-risk patients with documented candidemia. PMID:26868904

  16. Comparison of Antifungal Susceptibilities to Fluconazole and Voriconazole of Oral Candida glabrata Isolates from Head and Neck Radiation Patients

    Burn, A. K.; Fothergill, A W; Kirkpatrick, W. R.; Coco, B. J.; Patterson, T F; McCarthy, D I; Rinaldi, M.G.; Redding, S W


    The antifungal susceptibilities of 79 oral Candida glabrata isolates to fluconazole and voriconazole were compared. The MICs at which 90% of the isolates tested were inhibited were 1 μg of voriconazole/ml and 32 μg of fluconazole/ml. Oral C. glabrata isolates for which the fluconazole MICs are elevated are commonly those for which the voriconazole MICs are elevated, but these increases may be transient for voriconazole, as they are for fluconazole.

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

    J. Abirami Lakshmy


    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

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

    Valter Luis Iost Teodoro


    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.

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

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


    Penicillium species are some of the most common fungi observed worldwide and have an important economic impact as well as being occasional agents of human and animal mycoses. A total of 118 isolates thought to belong to the genus Penicillium based on morphological features were obtained from the Fungus Testing Laboratory at the University of Texas Health Science Center in San Antonio (United States). The isolates were studied phenotypically using standard growth conditions. Molecular identification was made using two genetic markers, the internal transcribed spacer (ITS) and a fragment of the β-tubulin gene. In order to assess phylogenetic relationships, maximum likelihood and Bayesian inference assessments were used. Antifungal susceptibility testing was performed according to CLSI document M38-A2 for nine antifungal drugs. The isolates were identified within three genera, i.e., Penicillium, Talaromyces, and Rasamsonia The most frequent species in our study were Penicillium rubens, P. citrinum, and Talaromyces amestolkiae The potent in vitro activity of amphotericin B (AMB) and terbinafine (TRB) and of the echinocandins against Penicillium and Talaromyces species might offer a good therapeutic alternative for the treatment of infections caused by these fungi. PMID:27280422

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

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


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

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

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


    Inter- and intraspecific genomic variability of 18 isolates of Veronaea botryosa originating from clinical and environmental sources was studied using amplified fragment length polymorphism (AFLP). The species was originally described from the environment, but several severe cases of disseminated infection in apparently healthy individuals have been reported worldwide. All tested strains of V. botryosa, identified on the basis of sequencing and phenotypic and physiological criteria prior to our study, were confirmed by AFLP analysis, yielding a clear separation of V. botryosa as a rather homogeneous group from related species. In vitro antifungal susceptibility testing resulted in MIC90s across all strains in increasing order posaconazole (0.25 μg/ml), itraconazole (1 μg/ml), voriconazole (4 μg/ml), terbinafine (4 μg/ml), caspofungin (8 μg/ml), anidulafungin (8 μg/ml), isavuconazole (16 μg/ml), amphotericin B (16 μg/ml), and fluconazole (32 μg/ml). Overall, the isolates showed a uniform pattern of low MICs of itraconazole and posaconazole, but high MICs for remaining agents. The echinocandins (caspofungin and anidulafungin) had no activity against V. botryosa. There was no statistically significant difference between susceptibilities of environmental (n = 11) and clinical (n = 7) isolates of V. botryosa (P > 0.05). PMID:23463524

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

    MOHAMMADI, R.; Ataei, B


    Background Candida species are normal microflora of oral cavity, vagina, and gastrointestinal tract. They are the third most prevalent cause of pediatric health care–associated bloodstream fungal infection. This study aimed to provide an epidemiological feature of candidiasis and also presents an antifungal susceptibility profile of clinical Candida isolates among children. Materials and Methods During July 2013 to February 2015, 105 patients from different hospitals of Isfahan, Iran, were ex...

  3. 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

    Crystiane Rodrigues Araújo


    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.

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

    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


    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. PMID:26162643

  5. Use of Fatty Acid RPMI 1640 Media for Testing Susceptibilities of Eight Malassezia Species to the New Triazole Posaconazole and to Six Established Antifungal Agents by a Modified NCCLS M27-A2 Microdilution Method and Etest

    Velegraki, Aristea; Alexopoulos, Evangelos C.; Kritikou, Stavroula; Gaitanis, George


    A novel formulation of RPMI 1640 medium for susceptibility testing of Malassezia yeasts by broth microdilution (BMD) and Etest is proposed. A modification of the NCCLS M27-A2 BMD method was used to test 53 isolates of Malassezia furfur (12 isolates), M. sympodialis (8 isolates), M. slooffiae (4 isolates), M. globosa (22 isolates), M. obtusa (2 isolates), M. restricta (2 isolates), M. pachydermatis (1 isolates), and M. dermatis (2 isolates) against amphotericin B, ketoconazole, itraconazole, f...

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

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


    In our multicenter study, we studied the distribution ofCandidaspecies in vulvovaginal candidiasis patients and investigated antifungal susceptibility profile and genotype ofCandida albicansin vaginal swab. A total of 115Candida albicansstrains were detected in 135 clinical isolates. Minimum inhibitory concentration determinations showed that 83% and 81% of the 115Candida albicansstrains 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 albicanswas 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 amongCandida albicansisolated from VVC patients. PMID:26468549

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

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


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

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

    Aghil Sharifzadeh


    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

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

    Patrício Godoy


    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.

  10. Antifungal susceptibility analysis of berberine, baicalin, eugenol and curcumin on Candida albicans

    Wu Jianhua; Wen Hai


    Objective: To analyze the antifungal effects of Chinese herb monomers, i.e. berberine, baicalin, eugenol and curcumin, on Candida albicans. Methods: After Candida albicans strain Y01-09 was incubated for 48 h in YEPD broth which contained different concentrations of Chinese herb components, the cell cycle, fluorescent intensity and the size of cell volume were detected by flow cytometry. Results: The 4 Chinese herb monomers could affect the cell cycle of Candida albicans in different ranges. The ratio of cells in S-G2-M period decreased as the agents concentration increased, indicating that the cell division was inhibited. The fluorescent intensity of Candida albicans cells became weaker after being incubated, which reflected the loss of DNA fragments. The higher the concentration was, the weaker the fluorescent intensity became. The cell size, cell diopter and particle size changed much as the agents concentration increased. Conclusion: Chinese herb monomers play the antifungal role in inhibiting cell division. FCM could be used to determine the susceptibility of antifungal agents.

  11. In vitro susceptibility patterns of clinically important Trichophyton and Epidermophyton species against nine antifungal drugs.

    Badali, Hamid; Mohammadi, Rasoul; Mashedi, Olga; de Hoog, G Sybren; Meis, Jacques F


    Despite the common, worldwide, occurrence of dermatophytes, little information is available regarding susceptibility profiles against currently available and novel antifungal agents. A collection of sixty-eight clinical Trichophyton species and Epidermophyton floccosum were previously identified and verified to the species level by sequencing the internal transcribed spacer (ITS) regions of rDNA. MICs of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole, terbinafine and MECs of caspofungin and anidulafungin were performed based on CLSI M38-A2. The resulting MIC90 s of all strains were, in increasing order, as follows: terbinafine (0.063 mg l(-1) ); posaconazole (1 mg l(-1) ); isavuconazole and anidulafungin (2 mg l(-1) ); itraconazole, voriconazole, amphotericin B, and caspofungin (4 mg l(-1) ) and fluconazole (>64 mg l(-1) ). These results confirm that terbinafine is an excellent agent for treatment of dermatophytosis due to T. rubrum, T. mentagrophytes, T. verrucosum, T. schoenleinii and E. floccosum. In addition, the new azoles POS and ISA are potentially useful antifungals to treat dermatophytosis. However, the clinical effectiveness of these novel antifungals remains to be determined. PMID:25757042

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

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


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




    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. 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

    Cristiane Yumi Koga-Ito


    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.

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

    Sharifzadeh, Aghil; Shokri, Hojjatollah


    Objective: The purpose of this study was to assay the antifungal activity of selected essential oils obtained from plants against both fluconazole (FLU)-resistant and FLU-susceptible C. albicans strains isolated from HIV positive patients with oropharyngeal candidiasis (OPC). Materials and Methods: The essential oils were obtained by hydrodistillation method from Myrtus communis (My. communis), Zingiber officinale roscoe (Z. officinale roscoe), Matricaria chamomilla (Ma. chamomilla), Trachysp...

  16. Antifungal susceptibility evaluation of Candida albicans isolated from buccal lesions of hiv-positive and HIV-negative patients

    Amanda Latercia Tranches DIAS


    Full Text Available The antifungal minimal inhibitory concentrations (MIC were determined to 35 samples of Candidaalbicans; 14 of them were isolated from HIV-positive patients, and 21 from HIV-negative patients with oral erythematouscandidosis. The aim of this study was to evaluate the performance of agar dilution method in the determination ofsusceptibility of Candida albicans isolated from buccal lesions of HIV-positive and negative patients to some antifungalsand compare the results with the plasmatic concentration reached by each one of these drugs. The samples were evaluated invitro by the agar dilution method and showed higher MIC values to ketoconazole, fluconazole, itraconazole andamphotericin B than the concentrations achieved by these antifungals in plasma. 88.9% of the samples presented in vitroresistance to ketoconazole and the plasmatic levels of this antifungal varied from 1 to 8 μg/mL. Regarding fluconazole anditraconazole, most samples presented MIC larger than 128 μg/mL and plasmatic concentration varying from 0.4 to 8 μg/mL.Only 11.9% of the samples were susceptible in vitro to fluconazole and 2.7% of them to itraconazol. The usageconcentrations prescribed for the topical antifungals nystatin, fenticonazole and miconazole are markedly higher than thevalues of MIC obtained. Related to nystatin, it was verified that its MIC values were between 1 and 4 μg /mL. Theplasmatic levels to this drug are extremely low. Fenticonazole presented a MIC value larger than 128 μg/mL. Relating tomiconazole, the plasmatic levels vary from 1 to 8 μg/mL and 11.9% of the samples presented in vitro susceptibility to thisdrug. No significant differences (p<0.05 were found in the susceptibility profiles of the samples obtained from HIVpositiveand HIV-negative patients.

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

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


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

  18. 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

    Emerson Roberto Siqueira


    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.

  19. Establishing a Method of Inoculum Preparation for Susceptibility Testing of Trichophyton rubrum and Trichophyton mentagrophytes

    Santos, D. A.; Barros, M. E. S.; J. S. Hamdan


    A total of 92 clinical isolates of dermatophytes (52 of Trichophyton rubrum and 40 of Trichophyton mentagrophytes) were selected for testing with six antifungal drugs (terbinafine, griseofulvin, clotrimazole, miconazole, isoconazole, and fluconazole) and two pairs of drug combinations (ketoconazole-cyclopiroxolamine and itraconazole-cyclopiroxolamine). Two methods of inoculum preparation for susceptibility testing were evaluated that used (i) inocula consisting only of microconidia of dermato...


    Ragini Ananth


    Full Text Available ABSTRACT: BACKGROUND AND OBJECTIVES: Fungal urinary tract infections have become frequent, as a result of increased use of broad spec trum antibiotics, corticosteroids, immunosuppressive drugs and bladder catheters in acut e care settings. The associated risk factors which are seen in cases of candiduria are: antibiotic therapy, female gender, urinary catheterization, surgical procedure and extended hos pitalization. Candiduria has become a potential source of morbidity and mortality if untre ated. We undertook a prospective study to note the incidence of non-Candida albicans in patien ts with urinary tract infection with special reference to speciation, antifungal susceptibility an d the associated risk factors. METHODS: Candida species isolated from urine samples of patient s with urinary tract infection were subjected to speciation using standard yeast identif ication protocol and CHROM agar. Antifungal Susceptibility testing was done by the disc diffusio n method to amphotericin B and fluconazole. Clinical details and risk factors of the patients we re noted down. RESULTS: Among the 60 culture positive cases, six Candida species which wer e isolated are : C.tropicalis (66.66%, C.albicans (13.33%, C.parapsilosis (8.33%, C.glabr ata (6.66%, C.kefyr (3.33% and C.guilliermondii (1.66% The susceptibility pattern s howed, that of the 60 isolates, 40% were resistant to fluconazole. No resistance was seen to amphotericin B. CONCLUSION: Isolation of non-Candida albicans species was more than Candida a lbicans. Candida tropicalis was the predominant isolate. The following risk factors were noted: 43.33 % of the patients had diabetes mellitus, 30%had history of prolonged antib iotics (cephalosporin and aminoglycosides, 16.66% had underlying renal pathol ogy, 3.33% had post –renal transplant status, 1.66% were on steroids, 1.66%had pregnancy a nd 3.33% had no identifiable risk factors.20% patients had an indwelling catheter in them. The antifungal

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

    Laura Bedin Denardi


    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.

  2. Real-Time Optical Antimicrobial Susceptibility Testing

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


    Rapid antibiotic susceptibility testing is in highly demand in health-care fields as antimicrobial resistant bacterial strains emerge and spread. Here we describe an optical screening system (oCelloScope), which based on time-lapse imaging of 96 bacteria-antibiotic combinations at a time......, 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 in...... complex samples from pigs suffering from catheter associated urinary tract infections. The oCelloScope system provides a fast high-throughput screening method to detect bacterial susceptibility that may entail earlier diagnosis and introduction of appropriate targeted therapy and thus combat the threat...

  3. In vitro susceptibility testing of anaerobic bacteria.

    Washington, J A


    In vitro susceptibility testing of anaerobic bacteria should be limited to isolates from persistent or recurrent infections that have been treated adequately and appropriately with antimicrobial agents and, in reference centers, to collections of isolates in order to monitor alterations in susceptibility of species to various antimicrobial agents. An agar dilution reference method is being evaluated currently; however, practicality limits sporadic testing of single isolates to disk elution or broth dilution techniques. No single disk diffusion method has yet been found to be acceptable for testing anaerobic bacteria, and the results obtained with standardized procedures for aerobic and facultatively anaerobic bacteria are not applicable to anaerobic bacteria. PMID:288163

  4. Susceptibility testing of Entamoeba histolytica

    The growth of Entamoeba histolytica in microtiter plates in vitro in a variety of environments with reduced oxygen tensions is reported. With 3% O2, 3% CO2, and 94% N2, the parasite growth in microtiter plates was identical to that in screw-capped culture tubes, as measured by [3H]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 [3H]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

  5. Susceptibility testing of Entamoeba histolytica

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


    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.

  6. Epidemiology, species distribution, antifungal susceptibility, and ERG11 mutations of Candida species isolated from pregnant Chinese Han women.

    Yang, L; Su, M Q; Ma, Y Y; Xin, Y J; Han, R B; Zhang, R; Wen, J; Hao, X K


    The widespread use of antifungal agents has led to increasing azole resistance in Candida species. A major azole-resistance mechanism involves point mutations in the ERG11 gene, which encodes cytochrome P450 lanosterol 14a-demethylase. In this study, vaginal swabs were obtained from 657 pregnant Chinese Han women and cultured appropriately. The open reading frame of the obtained fungal species were amplified by PCR and sequenced; additionally, the ERG11 gene of the isolated Candida species was amplified and sequenced, and the antifungal susceptibility of the isolated species was determined. The vaginal swabs of 124 women produced fungal cultures; five species of Candida were isolated from the patients, among which Candida albicans was predominant. Twelve C. albicans isolates (13.8%) were resistant to fluconazole and 2 (2.2%) were resistant to itraconazole. Seventeen mutations, including 9 silent and 8 missense mutations, were identified in the ERG11 gene of 31 C. albicans isolates. Our findings suggest that infection caused by C. albicans and non-C. albicansis common in Chinese Han women of reproductive age. Moreover, the relationship between Candida infection and certain epidemiological factors emphasizes the need to educate women about the precise diagnosis and punctual treatment of vaginitis. PMID:27173274

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

    Federico Silvestri


    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.

  8. Next-Generation Antimicrobial Susceptibility Testing

    Belkum, Alex van; Dunne, W. Michael


    Antimicrobial resistance has emerged as one of the most-significant health care problems of the new millennium, and the clinical microbiology laboratory plays a central role in optimizing the therapeutic management of patients with infection. This minireview explores the potential value of innovative methods for antimicrobial susceptibility testing of microorganisms that could provide valuable alternatives to existing methodologies in the very near future.

  9. Molecular characterisation and antifungal susceptibility of clinical Trichosporon isolates in India.

    Rastogi, Vijaylatha; Honnavar, Prasanna; Rudramurthy, Shivaprakash M; Pamidi, Umabala; Ghosh, Anup; Chakrabarti, Arunaloke


    In Asian countries, Trichosporon infection is a well-known disease in Japan. In India, the infection is increasingly recognised. The study was conducted to characterise the clinical Trichosporon isolates from India by phenotypic and molecular techniques. A total of 31 Trichosporon clinical isolates, recovered from patients of 14 hospitals across India were sequenced (ITS and IGS1 regions of rDNA). In vitro drug susceptibility testing of the isolates was performed against amphotericin-B, fluconazole, itraconazole, voriconazole and posaconazole. IGS1, rather than ITS sequences, correctly identified the isolates: Trichosporon asahii, 20; Trichosporon ovoides, 3; Trichosporon inkin, 2; Trichosporon asteroides, 1; Trichosporon mucoides, 1; Trichosporon loubieri, 1; Trichosporon debeurmannianum, 1; and Trichosporon dermatis, 1. Trichosporon asahii genotype III was the most common type, followed by genotype I and VII. Both these targets did not help to identify one Trichosporon to the species level. Trichosporon debeurmannianum, T. dermatis and T. asteroides were isolated for the first time from a human disease in India. The minimum inhibitory concentrations for voriconazole and posaconazole were within effective range. The study highlights the presence of wide range of Trichosporon species causing infection in India. Voriconazole or posaconazole may be the better drugs to treat such patients. PMID:27144725

  10. In vitro Antifungal Activity of Cucumis melo on Candida albicans

    Issa Gholampour-Azizi; Samaneh Rouhi; Fahimeh Yahyayi


    Background: With respect to the emergence of susceptibility of some fungi to antifungal agents, making use of medicinal plants is progressing. Objectives: The aim of this study was to verify the anti-fungal characteristics of mature and immature Cucumis melo fruit on Candida albicans. Materials and Methods: In this descriptive study, antifungal activity of aqueous, ethnolic and methanolic extracts of C. melo fruits were tested on C. albicans; also results were obtained by disc and well ...

  11. 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

    Cibele Massotti Magagnin


    . 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

  12. Epidemiology and antifungal resistance in invasive candidiasis

    Rodloff AC


    Full Text Available Abstract The epidemiology of Candida infections has changed over the last two decades: The number of patients suffering from such infections has increased dramatically and the Candida species involved have become more numerous as Candida albicans is replaced as an infecting agent by various non-C. albicans species (NAC. At the same time, additional antifungal agents have become available. The different Candida species may vary in their susceptibility for these various antifungals. This draws more attention to in vitro susceptibility testing. Unfortunately, several different test methods exist that may deliver different results. Moreover, clinical breakpoints (CBP that classify test results into susceptible, intermediate and resistant are controver- sial between CLSI and EUCAST. Therefore, clinicians should be aware that interpretations may vary with the test system being followed by the microbiological laboratory. Thus, knowledge of actual MIC values and pharmacokinetic properties of individual antifungal agents is important in delivering appropriate therapy to patients

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

    Thaís Pereira de Mello


    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.

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

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


    Invariant NKT (iNKT) cells play an important role in a variety of antimicrobial immune responses due to their ability to produce high levels of immune-modulating cytokines. Here, we investigated the role of iNKT cells in host defense against candidiasis using Jα18-deficient mice (Jα18(-/-) ), which lack iNKT cells. Jα18(-/-) mice were more resistant to the development of lethal candidiasis than wild-type (WT) mice. In contrast, treatment of WT mice with the iNKT cell activating ligand α-galactosylceramide markedly enhanced their mortality after infection with Candida albicans. Serum IL-10 levels were significantly elevated in WT mice in response to infection with C. albicans. Futhermore, IL-10 production increased after in vitro coculture of peritoneal macrophages with iNKT cells and C. albicans. The numbers of peritoneal macrophages, the production of IL-1β and IL-18, and caspase-1 activity were also significantly elevated in Jα18(-/-) mice after infection with C. albicans. The adoptive transfer of iNKT cells or exogenous administration of IL-10 into Jα18(-/-) reversed susceptibility to candidiasis to the level of WT mice. These results suggest that activation of iNKT cells increases the initial severity of C. albicans infection, most likely mediated by IL-10 induced modulation of macrophage antifungal activity. PMID:27151377

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

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


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

  16. Characterization of Candida spp. isolated from vaginal fluid: identification, antifungal susceptibility, and virulence profile - doi: 10.4025/actascihealthsci.v35i1.13557

    Terezinha Inez Estivalet Svidzinski


    Full Text Available A total of 101 (20.0% yeast samples were isolated from vaginal fluids of 504 non-hospitalized patients in Maringá, Paraná State, Brazil and Candida albicans was more frequent specie (93.1% identified by seminested PCR method. All the isolates were susceptible to amphotericin B and nystatin, and 93.1% of them were susceptible to fluconazole. The acid proteinase, hemolytic and phospholipase activities were observed in 99.0, 90.0, and 88.0% of Candida spp., respectively. Around 67.0% of the strains had adherence indexes of 0.5 to 1.5 yeasts by Vero cell, and most of them showed a hydrophilic profile. Correlation studies indicated hydrophilic yeasts presented higher adherence index, proteinase, and phospholipase activities; and a positive correlation between all enzymes was also observed. In addition, the isolates with high hemolytic activity were less susceptible to fluconazole and amphotericin B. These results of Candida prevalence and antifungal susceptibility corroborate with literature’s datas and correlation between virulence factors and MIC values suggest Candida isolates from vaginal fluid less susceptible to antifungal and with higher extracellular enzymes production can be more virulent to cause tissue damage.  

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

    SHI Jun-yan; WANG He; GUO Li-na; XU Ying-chun; SHI Yi; L(U) Huo-xiang; LIU Yong; ZHAO Wang-sheng; CHEN Dong-mei; XI Li-yan; ZHOU Xin


    Background During recent years, the incidence of serious infections caused by opportunistic fungi has increased dramatically due to alterations of the immune status of patients with hematological diseases, malignant tumors,transplantations and so forth. Unfortunately, the wide use of triazole antifungal agents to treat these infections has lead to the emergence of Aspergillus spp. resistant to triazoles. The present study was to assess the in vitro activities of five antifungal agents (voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin) against different kinds of Aspergillus spp. that are commonly encountered in the clinical setting.Methods The agar-based Etest MIC method was employed. One hundred and seven strains of Aspergillus spp. (5 species) were collected and prepared according to Etest Technique Manuel. Etest MICs were determined with RPMI agar containing 2% glucose and were read after incubation for 48 hours at 35℃. MIC50, MIC90 and MIC range were acquired by Whonet 5.4 software.Results The MIC90 of caspofungin against A. fumigatus, A. flavus and A. nidulans was 0.094 μg/ml whereas the MIC90 against A. niger was 0.19 μg/ml. For these four species, the MlC90 of caspofungin was the lowest among the five antifungal agents. For A. terrus, the MIC90 of posaconazole was the lowest. For A. fumigatus and A. flavus, the MlC90in order of increasing was caspofungin, posaconazole, voriconazole, itraconazole, and amphotericin B. The MIC of amphotericin B against A. terrus was higher than 32 μg/ml in all 7 strains tested.Conclusions The in vitro antifungal susceptibility test shows the new drug caspofungin, which is a kind of echinocandins, has good activity against the five species of Aspergillus spp. and all the triazoles tested have better in vitro activity than traditional amphotericin B.

  18. Disk susceptibility testing of slow-growing anaerobic bacteria.

    Kwok, Y Y; Tally, F P; Sutter, V L; Finegold, S M


    The susceptibility of 55 strains of slow-growing anaerobes to eight clinically useful or potentially useful antibiotics was determined by agar dilution and disk diffusion tests. Strains of the genera Peptococcus, Peptostreptococcus, Megasphaera, Veillonella, Eubacterium, Bifidobacterium, Clostridium, and Fusobacterium were included. All strains were susceptible to chloramphenicol, but varied in their susceptibility to penicillin, lincomycin, clindamycin, tetracyclines, and vancomycin. Correlation between minimal inhibitory concentration and inhibition zone diameters was generally good. Prediction of susceptibility based on zone diameter measurements appeared satisfactory. Although routine susceptibility testing of anaerobic bacteria is not recommended, there are circumstances where such testing is relevant to the clinical situation. For those laboratories ill-equipped to do dilution tests, a disk diffusion test would give relatively accurate preliminary information. Quantitative susceptibility tests could then be done by a reference laboratory. PMID:1137353

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

    Li, H.


    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 is large interest in the development of in vitro and/or in silico test systems as alternatives for the animal studies. The aim of the present thesis was to evaluate the applicability of combined in vi...

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

    Li, H.


    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 is

  1. Inhibition of heat-shock protein 90 enhances the susceptibility to antifungals and reduces the virulence of Cryptococcus neoformans/Cryptococcus gattii species complex.

    Cordeiro, Rossana de Aguiar; Evangelista, Antonio José de Jesus; Serpa, Rosana; Marques, Francisca Jakelyne de Farias; Melo, Charlline Vládia Silva de; Oliveira, Jonathas Sales de; Franco, Jônatas da Silva; Alencar, Lucas Pereira de; Bandeira, Tereza de Jesus Pinheiro Gomes; Brilhante, Raimunda Sâmia Nogueira; Sidrim, José Júlio Costa; Rocha, Marcos Fébio Gadelha


    Heat-shock proteins (Hsps) are chaperones required for the maintenance of cellular homeostasis in different fungal pathogens, playing an important role in the infectious process. This study investigated the effect of pharmacological inhibition of Hsp90 by radicicol on the Cryptococcus neoformans/Cryptococcus gattii species complex - agents of the most common life-threatening fungal infection amongst immunocompromised patients. The influence of Hsp90 inhibition was investigated regarding in vitro susceptibility to antifungal agents of planktonic and sessile cells, ergosterol concentration, cell membrane integrity, growth at 37 °C, production of virulence factors in vitro, and experimental infection in Caenorhabditis elegans. Hsp90 inhibition inhibited the in vitro growth of planktonic cells of Cryptococcus spp. at concentrations ranging from 0.5 to 2 μg ml- 1 and increased the in vitro inhibitory effect of azoles, especially fluconazole (FLC) (P biofilm formation and mature biofilms of Cryptococcus spp., notably for Cryptococcus gattii. Furthermore, Hsp90 inhibition compromised the permeability of the cell membrane, and reduced planktonic growth at 37 °C and the capsular size of Cryptococcus spp. In addition, Hsp90 inhibition enhanced the antifungal activity of FLC during experimental infection using Caenorhabditis elegans. Therefore, our results indicate that Hsp90 inhibition can be an important strategy in the development of new antifungal drugs. PMID:26645478

  2. Update on antifungal drug resistance mechanisms of Aspergillus fumigatus.

    Chamilos, G; Kontoyiannis, D P


    Although the arsenal of agents with anti-Aspergillus activity has expanded over the last decade, mortality due to invasive aspergillosis (IA) remains unacceptably high. Aspergillus fumigatus still accounts for the majority of cases of IA; however less susceptible to antifungals non-fumigatus aspergilli began to emerge. Antifungal drug resistance of Aspergillus might partially account for treatment failures. Recent advances in our understanding of mechanisms of antifungal drug action in Aspergillus, along with the standardization of in vitro susceptibility testing methods, has brought resistance testing to the forefront of clinical mycology. In addition, molecular biology has started to shed light on the mechanisms of resistance of A. fumigatus to azoles and the echinocandins, while genome-based assays show promise for high-throughput screening for genotypic antifungal resistance. Several problems remain, however, in the study of this complex area. Large multicenter clinical studies--point prevalence or longitudinal--to capture the incidence and prevalence of antifungal resistance in A. fumigatus isolates are lacking. Correlation of in vitro susceptibility with clinical outcome and susceptibility breakpoints has not been established. In addition, the issue of cross-resistance between the newer triazoles is of concern. Furthermore, in vitro resistance testing for polyenes and echinocandins is difficult, and their mechanisms of resistance are largely unknown. This review examines challenges in the diagnosis, epidemiology, and mechanisms of antifungal drug resistance in A. fumigatus. PMID:16488654

  3. Species distribution and antifungal susceptibility of 143 Candida strains%143株念珠菌菌种分布及对5种抗真菌药物的敏感性分析

    黄云昆; 朱雯梅; 高辉; 徐敏; 许丽虹; 王杨


    Objective To analyze the species distribution and antifungal susceptibility of 143 Candida strains isolated from clinical specimens. Methods A comprehensive study was carried out to analyze the species distribution of Candida spp. and their susceptibility to five commonly used antifungal agents. A total of 143 isolates were collected from Yan' an Hospital between 2005 and 2009. Antifungal susceptibility testing was conducted with ATB-Fungus-3 strip. Results Candida albicans accounted for 39. 2% (56/143), and non-albicans Candida spp. 60.8% (87/143), including Candida glabrata 24.5% (35/143), Candida tropicalis 7. 7% (11/143) and Candida parapsilosis 5.6% (8/143). Of the 143 Candida isolates, the overall percentage of strains susceptible to flucytosine, amphotericin B, fluconazole, itraconazole, and voriconazole was 86. 0%, 100%, 90.9%, 69.9%, and 93.5 %, respectively. About 91. l%, 100%, 96.4%, 82. 1 %, and 96.3% of the 56 Candida a lbicans strains were susceptible to these five antifungal agents. Of the 87 non-albicans Candida spp. isolates, the susceptibility rates were 82.8%, 100%, 87. 4%, 62. 1 %, and 92. 0%, respectively. Conclusions Candida albicans remains a common species in Candida infections. Non-albicans Candida spp. is also increasing. Candida albicans isolates are still highly susceptible to the common antifungal agents. Non-albicans Candida species are more resistant than Candida albicans. Clinical antifungal therapy should be based on the results of pathogen identification and antifungal susceptibility testing.%目的 分析临床标本中念珠菌属的菌种分布及对常用抗真菌药物的敏感性,为临床合理用药提供依据.方法 总结分析昆明市延安医院2005-2009年念珠菌属的菌种分布及其对5种常用抗真菌药物的敏感性.药敏试验采用ATB-Fungus-3微量稀释法.结果 在2005-2009年分离的共143株念珠菌中,白念珠菌占39.2%(56/143),非白念珠菌占60

  4. Reliability of provocative tests of motion sickness susceptibility

    Calkins, D. S.; Reschke, M. F.; Kennedy, R. S.; Dunlop, W. P.


    Test-retest reliability values were derived from motion sickness susceptibility scores obtained from two successive exposures to each of three tests: (1) Coriolis sickness sensitivity test; (2) staircase velocity movement test; and (3) parabolic flight static chair test. The reliability of the three tests ranged from 0.70 to 0.88. Normalizing values from predictors with skewed distributions improved the reliability.

  5. Caspofungin Etest susceptibility testing of Candida species

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


    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...... resistant (R). Such misclassifications were most commonly observed for Candida krusei (73.1%) and Candida glabrata (33.1%). The revised breakpoints cannot be safely adopted for these two species....

  6. [Internal quality control for antimicrobial susceptibility test: an experience feedback].

    Vedy, Serge


    Internal quality control (IQC) position in antimicrobial susceptibility testing must be evaluated attentively before using. Ours S. aureus ATCC 25923 use during year 2011 has given precious information that can be useful for other laboratories. First, IQC should never be used before checking that all the realisation process steps are controlled. It will then appear that reagents are the most susceptible to give false results. That's what happens in 2.74% of antimicrobial susceptibility test. IQC is then useful to limit their clinical's impact. However, IQC use also shows that quality improvement will be difficult without industrial producer's involvement. PMID:22826843

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

    Aslan, Hacer; Gülmez, Dolunay


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

  8. Are Creativity Tests Susceptible to Coaching?

    Fairweather, Elizabeth C.; Cramond, Bonnie; Landis, Rebecca Nordin


    Critics of creativity tests, some of which are used widely in determining student eligibility for special educational opportunities such as gifted programs, claim that scores on these tests can be improved with specific training on the scoring components of the tests. However, we could find no empirical evidence supporting this claim. So, we…

  9. Antifungal tests in phytochemical investigations: comparison of bioautographic methods using phytopathogenic and human pathogenic fungi.

    Rahalison, L; Hamburger, M; Monod, M; Frenk, E; Hostettmann, K


    The detection limits in two bioautographic assays have been determined for a series of antifungal compounds, including clinically used antimycotics, fungicidal agrochemicals, and various classes of secondary plant metabolites. Target organisms were the filamentous fungus Cladosporium cucumerinum and the yeast Candida albicans. For clinical agents and agrochemicals, the detection limits in the two assays reflected to a certain extent their known spectrum of activity. Most of the plant-derived compounds tested showed a positive response in both assays, but with detection limits varying by a factor up to tenfold. For screening purposes, it is thus advisable to use both tests, as some activities would otherwise go undetected. The MIC values of these substances were determined in order to verify a possible correlation with the detection limit in the bioautographic assays. PMID:8134415

  10. Susceptibility testing of fish cell lines for virus isolation

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


    Passage of cell cultures may adversely influence cell susceptibility to virus infection through selection of cell clones that thrive in vitro but may not necessarily display high sensitivity to virus infection. Susceptibility to a given virus can therefore vary not only between cell lines and......-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...

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

    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.

  12. Antifungal activity of traditional medicinal plants from Tamil Nadu, India

    Duraipandiyan V; Ignacimuthu S


    Objective:To assess the antifungal activity of hexane, ethyl acetate and methanol extracts of 45 medicinal plants and to determine the minimum inhibitory concentration for each extract against human pathogenic fungi. Methods:A total of 45 medicinal plants were collected from different places of Tamil Nadu and identified. Hexane, ethyl acetate and methanol extracts of 45 medicinal plants were assessed for antifungal susceptibility using broth microdilution method. Two known antifungal agents were used as positive controls. Results: Most of the extracts inhibited more than four fungal strains. From the evaluation we found that ethyl acetate extracts inhibited large number of fungal growth. Hexane extracts also nearly showed the same level of inhibition against fungal growth. Methanol extracts showed the minimum antifungal activity. Among the 45 plants tested, broad spectrum antifungal activity was detected in Albizzia procera (A. procera), Atalantia monophylla, Asclepias curassavica, Azima tetracantha, Cassia fistula (C. fistula), Cinnomomum verum, Costus speciosus (C. speciosus), Nymphaea stellata, Osbeckia chinensis, Piper argyrophyllum, Punica granatum, Tinospora cordifolia and Toddalia asiatica (T. asiatica). Promising antifungal activity was seen in A. procera, C. speciosus, C. fistula and T. asiatica. Conclusions:It can be concluded that the plant species assayed possess antifungal properties. Further phytochemical research is needed to identify the active principles responsible for the antifungal effects of some of these medicinal plants.

  13. Personalized Genetic Testing and Norovirus Susceptibility

    Natalie Prystajecky


    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.

  14. [Antimicrobial susceptibility testing of anaerobic bacteria].

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


    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. PMID:24630580

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

    Syed Hakim Masood


    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.

  16. Aerobic and anaerobic susceptibility tests with three tetracyclines. Reassessment of the "class concept" of disk testing.

    Barry, A L; Draper, D L; Wong, M K


    Both aerobic and anaerobic susceptibility tests were performed with tetracycline, doxycycline, and minocycline, using disk diffusion and agar dilution technics. The data were examined in order to reassess the concept of testing a single disk, representative of the tetracycline class of antimicrobics. All strains that were susceptible to a tetracycline disk were predictably susceptible to the tetracycline analogs. Some strains that gave zones in the resistant or intermediate range were susceptible or moderately susceptible to doxycycline and minocycline by agar dilution methods. However, disk tests with the more active analogs were often unproductive, since most tetracycline-resistant strains gave indeterminate results with doxycycline or minocycline disks. It was concluded that the "class concept" of disk testing is still appropriate and that tests with tetracycline disks predict susceptibility to the other tetracycline analogs reasonably well. PMID:717289

  17. Effect of incubation conditions on anaerobic susceptibility testing results.

    Murray, P R; Niles, A C


    We determined the effect of performing antimicrobial susceptibility tests in five different anaerobic incubation systems: GasPak jar, large GasPak jar, evacuated-gassed anaerobic jar, anaerobic chamber, and Bio-Bag. Growth of the anaerobes was equivalent in all five incubation systems. The results of testing 38 anaerobes against 11 antimicrobial agents were comparable for the anaerobic jars and anaerobic chamber. However, discordant results were observed for metronidazole and cefamandole test...

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

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


    A three-month laboratory-based prospective survey was conducted at four major university hospitals covering one-third of the Danish population in order to determine the prevalence, significance, and susceptibility pattern of aspergilli in airway samples. Samples received in January-March 2007 for...

  19. Agar dilution method for susceptibility testing of Neisseria gonorrhoeae

    Marta C de Castillo


    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.

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

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


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




    Full Text Available PURPOSE: Fungal infections with candida species are an import ant cause of morbidity and mortality 1 . Situation is further worsened by increasing resis tance to antifungal drugs 2 .The objective of this study was to evaluate antifu ngal susceptibility pattern of Candida species to fluconazole by disc diffusion and agar di lution method and compare these two methods as far as fluconazole is concerned. MATERIAL & METHODS: Between January 2006 to December 2006, 119 Candida species were isolated fro m 225 sputum samples of patients of pulmonary tuberculosis and immunocomprised patients. RESULTS: Of the 119 Candida isolates 33 (27.73% were Candida albicans, 32 (26.89% were Candida gullermondi, 27 (22.68% Candida tropicalis, 14 (11.76% Candida pseudotropica lis, 7 (5.88% Candida parapsilosis and 6 (5.04% were Candida krusei. The Candida isolates w ere tested for fluconazole by disc diffusion method on Muller hinton agar with 2% glucose and 0. 5 microgram of methylene blue 3 .Amongst the 119 Candida isolates, 17 (14.28% isolates were resistant to fluconazole by disc diffusion method. MIC done by agar dilution method using CLSI guidelines 4. Candida isolates showed growth of 15 (88 .23% Candida strains upto 8 micro gram / ml with 80% inhibition of growth whereas 2 (1.7% isolates showed MIC upto 64 microgr am/ ml. CONCLUSIONS: Candida albicans though a common species other species were i solated in significant number. The results of disc diffusion for fluconazole do not co rrelate with agar dilution method. To cater the need of resource constrained laboratories, it is im portant to have results that correspond to the clinical outcome of antifungal treatment and show c o-relation to those obtained with the reference method as recommended by CLSI guidelines and also be reproducible 5 . Further critical studies are needed

  2. Susceptibility of anaerobic bacteria to sulfamethoxazole/trimethoprim and routine susceptibility testing.

    Wüst, J; Wilkins, T D


    The minimal inhibitory concentrations (MICs) of sulfamethoxazole and trimethoprim against 144 strains of obligately anaerobic bacteria were determined on Diagnostic Sensitivity Test agar (Oxoid) or in prereduced Diagnostic Sensitivity Test broth, both supplemented with sodium pyruvate (1 mg/ml), hemin (5 mug/ml), and vitamin K(1) (1 mug/ml). Fifty-eight percent of the strains were susceptible to sulfamethoxazole alone (MIC disk test proposed by Wilkins and Thiel, modified by using prereduced Diagnostic Sensitivity Test broth instead of brain heart infusion broth and by using a smaller inoculum, there was over 90% correlation with the MICs. Poor results were found when the broth-disk tests were performed in brain heart infusion broth. There was very poor correlation between inhibition zone diameters by an agar diffusion method and MICs. PMID:708016

  3. Antimicrobial susceptibility testing of less commonly isolated Haemophilus species using Haemophilus test medium.

    Jorgensen, J H; Howell, A W; Maher, L A


    Haemophilus test medium (HTM) was developed recently for dilution and disk diffusion antimicrobial agent susceptibility testing of Haemophilus influenzae. The application of HTM to the testing of other, less frequently encountered Haemophilus species recovered from humans was evaluated in this study by using commercially prepared HTM (BBL Microbiology Systems, Cockeysville, Md.) in broth microdilution and agar disk diffusion susceptibility tests with 18 antimicrobial agents. A total of 93.3% ...

  4. Susceptibility testing with the sensititer breakpoint broth microdilution system.

    Doern, G V; Dascal, A; Keville, M


    The antimicrobial susceptibility profiles of a total of 318 aerobic and facultatively anaerobic bacteria (255 gram-negative bacilli and 63 gram-positive cocci) were determined, using a new commercially available breakpoint broth microdilution procedure (Sensititer Breakpoint System (SBS), Gibco Diagnostics, Inc., Madison, WI) that categorizes test results in the form of susceptibility categories: susceptible, intermediate, and resistant. Results obtained with the SBS were compared with those achieved with a standardized disk diffusion procedure. Among a total of 4,414 organism-antimicrobic comparisons, concordance between the results of the SBS and the disk diffusion procedure was observed in 3,888 cases (88.1%). Four hundred twenty-three (9.6%) minor discrepancies, 45 (1.0%) major discrepancies, and 58 (1.3%) very major discrepancies were noted. Arbitration of major and very major discrepancies with a full-range minimum inhibitory concentration (MIC) procedure confirmed the results of the SBS in 53.4% of cases. A single organism-antimicrobial combination, the nonenterococcal streptococci tested against the aminoglycosides, yielded a significant number of very major errors which were arbitrated in favor of the disk diffusion result. These errors were probably due to poor growth of the test organism in the broth medium used for performing the SBS test (i.e., cation-supplemented Mueller-Hinton broth). With this exception, the SBS was found to be at least as accurate as the standardized disk diffusion procedure. PMID:3922668

  5. In vitro susceptibility testing of Paracoccidioides brasiliensis to sulfonamides.

    Restrepo, A; Arango, M D


    A total of 60 clinical isolates of Paracoccidioides brasiliensis were tested for susceptibility to sulfadiazine and sulfadimethoxyne by the agar dilution technique. A modification of the Mueller-Hinton medium was devised which gave good growth of the yeast form. The minimum inhibitory concentrations for only 51.6% of the isolates were in the range of the recommended blood serum concentration (50 micrograms/ml). For 6 to 8% of the isolates, the minimum inhibitory concentrations were above 200 ...

  6. Evaluation of the disc diffusion method with a comparison study for fluconazole susceptibility of Candida strains


    Objective To performance susceptibility testing of antifungal agents. Due to the increasing number of resistant strains, susceptibility testing of antifungal agents is gaining importance. Methods We compared the results of standard macrotube dilution reference method with two different microdilution methods, as well as the disc diffusion method in order to test the susceptibility of 150 Candida strains to fluconazole. Results Overall correlation between microdilution and macrodilution methods was 86%. It was 91% between the Minimal Inhibitory Concentrations obtained from macrodilution and disc diffusion zone diameters. Conclusion The disc diffusion test was evaluated as a low-cost, reproducible, and efficient way of assessing the in vitro susceptibility of Candida strains to fluconazole.

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

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


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

  8. 含有额外拷贝黄曲霉cyp51同源基因的烟曲霉对抗真菌药物的敏感性测定%Antifungal susceptibility of the A.fumigatus transformants containing extra copies of A.flavus cyp51 gene homologues to the common antifungal drugs

    刘伟霞; 孙毅; 万喆; 李若瑜; 刘伟


    Objective To investigate the effect of Aspergillus flavus cyp51 genes on antifungal susceptibility by cloning and constucting the extra copies of Aspergillus flavus cyp51 genes. Methods A.flavus cyp5l gene homologues were identified by tblastn searches inA. flavus genome database. PCR fragments composed of the 5'flanking sequence (approximately 1 000 bp) ofcyp51 ,cyp51 ORF, and its 3'flanking sequence (approximately 1 000 bp), were subcloned into shuttle plasmid pRG3-AMAl-NotI to produce recombinant plasmids. These plasmids and empty plasmid pRG3-AMA1-Notl were transformed into A.fumigatus strain AF293.1 (pyrG-) respectively to produce transformants. The Clinical Laboratory Standard Institute broth microdilution method M38-A2 and E-test method were used to assay the minimal inhibitory concentrations (MICs) of itraconazole ( ITC), voriconazole ( VRC), amphotericin B (AMB), and posaconazole (POS), or minimal effect concentration (MEC) of caspofungin (CAS), against these transformants. Results A. flavus genome contains three cyp51 gene homologues, cyp51A ,cyp51B and cyp51 C, of which the ORF size are 1 400-2 000 bp. When these genes were subcloned into shuttle plasmid pRG3-AMA1-NotI, we get plasmids pRG3-AMA1-CYP51 A, pRG3-AMA1-CYP51B and pRG3-AMA1-CYP51C. These plasmids and empty plasmid were transformed into A.fumigatus strain AF293.1 (pyrG-) to produce transformants rCYP51A, rCYP51B, rCYP51C and rpRG. The antifungal susceptibility of these A.fumigatus transformants to the antifungal drugs by broth microdilution assaying and E-test method showed that, rCYP51A and rCYP51B were cross-resistant to VRC and ITC, susceptible to both AM B and CAS; rCYP51C and rpRG were intermediate to ITC and VRC, susceptible to both A MB and CAS. Conclusion In A. fumigatus , extra copies of A.flavus ' cyp51A gene or cyp51B gene have effect on antifungal susceptibility to azoles, have no effect on AMB and CAS. Extra copy ofcyp51C has no obvious effect on all the tested drugs.%目的

  9. High-throughput metal susceptibility testing of microbial biofilms

    Turner Raymond J


    Full Text Available Abstract Background 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. Results 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 (TeO32- than corresponding planktonic cultures. Regardless of the growth medium, the tolerance of biofilm and planktonic

  10. Inoculum Standardization for Antifungal Susceptibility Testing of Filamentous Fungi Pathogenic for Humans

    Petrikkou, Eva; Rodríguez-Tudela, Juan L.; Cuenca-Estrella, Manuel; Gómez, Alicia; Molleja, Ana; Mellado, Emilia


    Two methods of inoculum preparation for filamentous fungi were compared: counting with a hematocytometer and spectrophotometric adjustment. One hundred eighty-two filamentous fungi pathogenic for humans were used. Colony counts were done for all inoculum preparations. The agreement between the hematocytometer counts and the colony counts (CFU per milliliter) was 97.2%. The reproducibility between the hematocytometer counts and the colony counts by means of an intraclass correlation coefficien...

  11. Atmospheric pressure cold plasma as an antifungal therapy

    A microhollow cathode based, direct-current, atmospheric pressure, He/O2 (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.

  12. Performance of the microscopic observation drug susceptibility assay in pyrazinamide susceptibility testing for Mycobacterium tuberculosis

    HUANG Zi-kun; LUO Qing; JIANG Bi-xia; LI Wei-ting; XU Xiao-meng; XIONG Guo-liang; LI Jun-ming


    Background Drug susceptibility assay is very important in tuberculosis therapy.Pyrazinamide is a first line antituberculosis drug and diagnosis of its resistance in Mycobacterium tuberculosis (M.tuberculosis) is difficult and time consuming by conventional methods.In this study,we aimed to evaluate the performance of the microscopic observation drug susceptibility (MODS) assay in the detection of pyrazinamide resistance in M.tuberculosis relative to the conventional Wayne assay and Lowenstein-Jensen (L J) proportion method.Methods M.tuberculosis clinical isolates (n=132) were tested by the MODS and the Wayne assay:the results were compared with those obtained by the LJ proportion method.Mutations in the gene were identified by direct sequencing of the pncA genes of all isolates in which pyrazinamide resistance was detected by any of the three methods.Results Compared to the LJ results,the sensitivity and specificity of the MODS assay were 97.8% and 96.5% respectively; the sensitivity and specificity of the Wayne assay were 87.0% and 97.7% respectively.Mutations in the pncA gene were found in 41 of 46 strains that were pyrazinamide resistant (3 tests),in 1 of the 4 strains (LJ only),in 42 of 48 strains (at least 1 test),but no mutations in 1 strain sensitive according to the MODS assay only.The MODS assay,Wayne assay and LJ proportion method provided results in a median time of 6,7 and 26 days respectively.Conclusions MODS assay offers a rapid,simple and reliable method for the detection of pyrazinamide resistance in M.tuberculosis and is an optimal alternative method in resource limited countries.

  13. Screening of Embelia ribes for Antifungal Activity

    Maulik Suthar


    Full Text Available The fruits of Embelia ribes reported to contain mainly benzoquinone derivatives such as Embelin (2, 5-dihydroxy-3-undecyl-2, 5-cyclohexadiene-1, 4-benzoquinone. Chemical structure of Embelin is having quite resemblance with the structure of natural Coenzyme Q10 (ubiquinones and the role of this is well defined in various biochemical protective mechanism. Aim of the present study was to evaluate the antifungal activity of Embelia ribes (Myrsinaceae plant extracts using standard in vitro antifungal susceptibility test methods like NCCLS M27- A2 protocol (The National Committee for Clinical Laboratory Standards , USA and EUCAST (European Committee for Antifungal Susceptibility Tests. Values of the MIC50 obtained by NCCLS method revealed that Methanol extract and Embelin exhibited lowest MIC50 values against C. albican (183 which was 120 mg/L. Embelin's MIC50 values were below 700 mg/L for C. albican, C. tropicalis, C. parapsilosis, C. albidus and A. flavus. Diethyl ether extract, petroleum ether extract, methanol extract and embelin obtained MIC50 in range of 300-700 mg/L against C. albican and C. parapsilosis. Petroleum ether extract showed lowest MIC50 values for C. parapsilosis (250 mg/L; C. laurintis (360 mg/L; I.orientalis (180 mg/L and A. fumigatus(170 mg/L.

  14. Susceptibility of anaerobic bacteria to metronidazole, ornidazole, and tinidazole and routine susceptibility testing by standardized methods.

    Wust, J


    A total of 114 strains of anaerobic bacteria were examined for their susceptibility to metronidazole, ornidazole, and tinidazole by measuring the minimum inhibitory concentration (MIC) and minimum bactericidal concentration in different media. All strains, with the exception of the isolates of Propionibacterium acnes, were inhibited by 3.1 mug each and killed by 6.3 mug each of all three nitroimidazole compounds per ml. No significant differences in MIC values were found among metronidazole, ornidazole, and tinidazole. Only minor differences were detected by comparing MIC values obtained in brain heart infusion agar with and without sheep blood, brucella agar, and Mueller-Hinton agar (both containing blood). When the strains were tested by the modified broth-disk method proposed by the Anaerobe Laboratory of the Virginia Polytechnic Institute (VPI), there was good correlation with the MIC values (97.4% agreement for metronidazole and 94.7% for ornidazole and tinidazole). For routine testing, use of a 30-mug-class disk of either nitroimidazole derivative is proposed for the broth-disk method, resulting in a final concentration of 6 mug/ml in the test tubes, a concentration easily attainable in body fluids. In contrast to the broth-disk method, there was very poor correlation between inhibition zone diameters by the standardized VPI agar diffusion test and MIC values. PMID:856015

  15. Susceptibility

    Petrovský, Eduard

    Dordrecht: Springer, 2007 - (Gubbins, D.; Herrero-Bervera, E.), s. 931-933. (Encyclopedia of Earth sciences series). ISBN 978-1-4020-3992-8 Institutional research plan: CEZ:AV0Z30120515 Keywords : magnetic susceptibility * magnetic field * magnetization curve Subject RIV: DE - Earth Magnetism, Geodesy, Geography

  16. Disk diffusion susceptibility testing of the Bacteroides fragilis group.

    Horn, R; Bourgault, A M; Lamothe, F


    The susceptibilities of 225 isolates of the Bacteroides fragilis group to six antibiotics were determined by a new disk diffusion test in Wilkins-Chalgren agar and by the standard agar dilution method. For disk diffusion, the bacteria were directly suspended in saline and immediately swabbed onto 15-cm agar plates. Disks of cefoxitin (30 micrograms), chloramphenicol (30 micrograms), clindamycin (2 micrograms), moxalactam (30 micrograms), imipenem (10 micrograms), and ticarcillin (75 micrograms) were applied, and the plates were incubated at 37 degrees C in an anaerobic atmosphere. Zone sizes were measured at 24 h. The results of disk diffusion and agar dilution were compared by regression analysis by the method of least squares and by the error rate-bounded method. Zones were easily measured for 216 strains (96%). The correlation between the MICs and diameters of inhibition for cefoxitin, clindamycin, moxalactam, and ticarcillin was generally good. A correlation could not be established for chloramphenicol and imipenem, as there were too few resistant strains. With the recommended resistance breakpoints, the following susceptible and resistant zone diameter breakpoints could be established: cefoxitin, less than or equal to 19 and greater than or equal to 21 mm; clindamycin, less than or equal to 14 and greater than or equal to 18 mm; moxalactam, less than or equal to 21 and greater than or equal to 25 mm; and ticarcillin, less than or equal to 15 and greater than or equal to 16 mm. By applying these zone criteria, the percentage of false-susceptible strains was less than 1% and of false-resistant strains was less than 4% for the drugs tested. PMID:3481247

  17. Antifungal activity of TiO2 photocatalysis against Penicillium expansum in vitro and in fruit tests.

    Maneerat, Chamorn; Hayata, Yasuyoshi


    The antifungal activity of TiO2 photocatalytic reaction in the form of TiO2 powder and TiO2 coated on a plastic film against Penicillium expansum was investigated in vitro and in fruit tests. The mixture of P. expansum conidial suspension and TiO2 powder was added to potato dextrose agar (PDA) plates for vitro test. The TiO2 photocatalytic reaction reduced conidial germination of the fungal pathogen. It was found that the ability of the TiO2 photocatalytic reaction to suppress P. expansum growth correlated to the amount of TiO2 added. Lower numbers of viable colonies of P. expansum were observed with increasing amount of TiO2. Regardless of the kind of selected fruit inoculated with P. expansum, both TiO2 powder and TiO2-coated film exhibited antifungal activity to control fruit rot. Development of Penicillium rot in apple was significantly (P = 0.05) retarded by the TiO2 photocatalytic reaction. Similarly the TiO2 photocatalytic reaction was the only treatment where no tomato fruit rot was noticeable after 1 week of storage. TiO2-coated film also decreased brown lesions and Penicillium rot infection in lemons. The mean severity fruit rot scores (browning and softening flesh) were 3.2 and 1.9 for uncoated and TiO2-coated film, respectively. Our findings suggest that "TiO2 photocatalytic reaction" shows antifungal activity against P. expansum which may have potential for postharvest disease control. PMID:16269195

  18. Comprehensive approach for the detection of antifungal compounds using a susceptible strain of Candida albicans and confirmation of in vivo activity with the Galleria mellonella model.

    Favre-Godal, Quentin; Dorsaz, Stéphane; Queiroz, Emerson Ferreira; Conan, Céline; Marcourt, Laurence; Wardojo, Bambang Prajogo Eko; Voinesco, Francine; Buchwalder, Aurélie; Gindro, Katia; Sanglard, Dominique; Wolfender, Jean-Luc


    An efficient screening strategy for the identification of potentially interesting low-abundance antifungal natural products in crude extracts that combines both a sensitive bioautography assay and high performance liquid chromatography (HPLC) microfractionation was developed. This method relies on high performance thin layer chromatography (HPTLC) bioautography with a hypersusceptible engineered strain of Candida albicans (DSY2621) for bioactivity detection, followed by the evaluation of wild type strains in standard microdilution antifungal assays. Active extracts were microfractionated by HPLC in 96-well plates, and the fractions were subsequently submitted to the bioassay. This procedure enabled precise localisation of the antifungal compounds directly in the HPLC chromatograms of the crude extracts. HPLC-PDA-mass spectrometry (MS) data obtained in parallel to the HPLC antifungal profiles provided a first chemical screening about the bioactive constituents. Transposition of the HPLC analytical conditions to medium-pressure liquid chromatography (MPLC) allowed the efficient isolation of the active constituents in mg amounts for structure confirmation and more extensive characterisation of their biological activities. The antifungal properties of the isolated natural products were evaluated by their minimum inhibitory concentration (MIC) in a dilution assay against both wild type and engineered strains of C. albicans. The biological activity of the most promising agents was further evaluated in vitro by electron microscopy and in vivo in a Galleria mellonella model of C. albicans infection. The overall procedure represents a rational and comprehensive means of evaluating antifungal activity from various perspectives for the selection of initial hits that can be explored in more in-depth mode-of-action studies. This strategy is illustrated by the identification and bioactivity evaluation of a series of antifungal compounds from the methanolic extract of a Rubiaceae

  19. In vitro antifungal effect of EDTA disodium salt in tested black aspergilli

    Abrunhosa, Luís; Venâncio, Armando


    The antifungal effect of Na2EDTA on an Aspergillus carbonarius, an A. ibericus, an ochratoxigenic A. niger and a non-ochratoxigenic A. niger strain was studied. Also, the effect of Na2EDTA on the production of ochratoxin A by A. carbonarius and the ochratoxigenic A. niger was evaluated. The poisoned food technique was used with CYA medium supplemented with 0, 1 and 10 mmol L-1 of Na2EDTA. The colony diameters were recorded daily and the amount of ochratoxin A produced was quantified every two...

  20. Static NLO susceptibilities testing approximation schemes against exact results

    Del Freo, L; Painelli, A; Freo, Luca Del; Terenziani, Francesca; Painelli, Anna


    The reliability of the approximations commonly adopted in the calculation of static optical (hyper)polarizabilities is tested against exact results obtained for an interesting toy-model. The model accounts for the principal features of typical nonlinear organic materials with mobile electrons strongly coupled to molecular vibrations. The approximations introduced in sum over states and finite field schemes are analyzed in detail. Both the Born-Oppenheimer and the clamped nucleus approximations turn out to be safe for molecules, whereas for donor-acceptor charge transfer complexes deviations from adiabaticity are expected. In the regime of low vibrational frequency, static susceptibilities are strongly dominated by the successive derivatives of the potential energy and large vibrational contributions to hyperpolarizabilities are found. In this regime anharmonic corrections to hyperpolarizabilities are very large, and the harmonic approximation, exact for the linear polarizability, turns out totally inadequate ...

  1. Characterization of Renibacterium salmoninarum with reduced susceptibility to macrolide antibiotics by a standardized antibiotic susceptibility test.

    Rhodes, Linda D; Nguyen, Oanh T; Deinhard, Rebecca K; White, Teresa M; Harrell, Lee W; Roberts, Marilyn C


    Three cohorts of juvenile and subadult Chinook salmon Oncorhynchus tshawytscha received multiple treatments with macrolide antibiotics for bacterial kidney disease (BKD) during rearing in a captive broodstock program. A total of 77 mortalities among the cohorts were screened for Renibacterium salmoninarum, the etiologic agent of BKD, by agar culture from kidney, and isolates from 7 fish were suitable for growth testing in the presence of macrolide antibiotics. The minimum inhibitory concentration (MIC) of erythromycin and azithromycin was determined by a modification of the standardized broth assay using defined medium. The American Type Culture Collection (ATCC) type strain 33209 exhibited a MIC of 0.008 microg m(-1) to either erythromycin or azithromycin. Isolates from 3 fish displayed MICs identical to the MICs for the ATCC type strain 33209. In contrast, isolates from 4 fish exhibited higher MICs, ranging between 0.125 and 0.250 microg ml(-1) for erythromycin and between 0.016 and 0.031 microg ml(-1) for azithromycin. Sequence analysis of the mutational hotspots for macrolide resistance in the 23S rDNA gene and the open reading frames of ribosomal proteins L4 and L22 found identical sequences among all isolates, indicating that the phenotype was not due to mutations associated with the drug-binding site of 23S rRNA. These results are the first report of R. salmoninarum with reduced susceptibility to macrolide antibiotics isolated from fish receiving multiple antibiotic treatments. PMID:18814542

  2. High-Throughput Intracellular Antimicrobial Susceptibility Testing of Legionella pneumophila.

    Chiaraviglio, Lucius; Kirby, James E


    Legionella pneumophila is a Gram-negative opportunistic human pathogen that causes a severe pneumonia known as Legionnaires' disease. Notably, in the human host, the organism is believed to replicate solely within an intracellular compartment, predominantly within pulmonary macrophages. Consequently, successful therapy is predicated on antimicrobials penetrating into this intracellular growth niche. However, standard antimicrobial susceptibility testing methods test solely for extracellular growth inhibition. Here, we make use of a high-throughput assay to characterize intracellular growth inhibition activity of known antimicrobials. For select antimicrobials, high-resolution dose-response analysis was then performed to characterize and compare activity levels in both macrophage infection and axenic growth assays. Results support the superiority of several classes of nonpolar antimicrobials in abrogating intracellular growth. Importantly, our assay results show excellent correlations with prior clinical observations of antimicrobial efficacy. Furthermore, we also show the applicability of high-throughput automation to two- and three-dimensional synergy testing. High-resolution isocontour isobolograms provide in vitro support for specific combination antimicrobial therapy. Taken together, findings suggest that high-throughput screening technology may be successfully applied to identify and characterize antimicrobials that target bacterial pathogens that make use of an intracellular growth niche. PMID:26392509

  3. High-Throughput Intracellular Antimicrobial Susceptibility Testing of Legionella pneumophila

    Chiaraviglio, Lucius


    Legionella pneumophila is a Gram-negative opportunistic human pathogen that causes a severe pneumonia known as Legionnaires' disease. Notably, in the human host, the organism is believed to replicate solely within an intracellular compartment, predominantly within pulmonary macrophages. Consequently, successful therapy is predicated on antimicrobials penetrating into this intracellular growth niche. However, standard antimicrobial susceptibility testing methods test solely for extracellular growth inhibition. Here, we make use of a high-throughput assay to characterize intracellular growth inhibition activity of known antimicrobials. For select antimicrobials, high-resolution dose-response analysis was then performed to characterize and compare activity levels in both macrophage infection and axenic growth assays. Results support the superiority of several classes of nonpolar antimicrobials in abrogating intracellular growth. Importantly, our assay results show excellent correlations with prior clinical observations of antimicrobial efficacy. Furthermore, we also show the applicability of high-throughput automation to two- and three-dimensional synergy testing. High-resolution isocontour isobolograms provide in vitro support for specific combination antimicrobial therapy. Taken together, findings suggest that high-throughput screening technology may be successfully applied to identify and characterize antimicrobials that target bacterial pathogens that make use of an intracellular growth niche. PMID:26392509

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

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


    Rifaximin is a rifampicin derivative, poorly absorbed by the gastro-intestinal tract. We studied the in vitro susceptibility to rifamixin of 1082 Clostridium difficile isolates; among these,184 isolates from a strain collection were tested by an in-house rifaximin disc (40 µg) diffusion test, by an in-house rifaximin broth microdilution test, by rifampicin Etest and by rpoB gene sequencing. In the absence of respective CLSI or EUCAST MIC breakpoints for rifaximin and rifampicin against C. dif...

  5. Effects of the association of antifungal drugs on the antimicrobial action of endodontic sealers

    Paulo Henrique WECKWERTH


    Full Text Available This in vitro study aimed to determine the susceptibility of oral specimens and ATCC lineages of Candida albicans for five endodontic sealers, which were pure and associated with two antifungal drugs, and to analyze their effect on the physical properties. For this purpose, 30 lineages of C. albicans, collected from the oral cavity of patients assisted at the endodontics clinic of the Universidade Sagrado Coração, were analyzed. Yeasts susceptibility to the sealers was tested by diffusion on agar plates. Physical properties were evaluated according to the ADA specification no. 57. The pure versions of the Sealer 26, AH Plus, Endofill, Fillapex, and Sealapex demonstrated antifungal activity, with Endofill presenting the greatest inhibition zones. All cements, except for Endofill, had their antifungal actions enhanced by addition of ketoconazole and fluconazole (p < 0.05, and the AH Plus presented the best antifungal activity. The addition of antifungal drugs did not interfere with the setting time and flowability of the sealers. It was concluded that the addition of antifungals to endodontic sealers enhanced the antimicrobial action of most cements tested without altering their physical properties.

  6. Transcriptional regulation of drug-resistance genes in Candida albicans biofilms in response to antifungals.

    Watamoto, T; Samaranayake, L P; Egusa, H; Yatani, H; Seneviratne, C J


    Biofilm formation is a major virulence attribute of Candida albicans and is directly associated with therapeutic failure. One method by which Candida acquires antifungal resistance is the expression of drug-resistance genes. This study aimed to evaluate the transcriptional regulation of several genes associated with antifungal resistance of C. albicans under planktonic, recently adhered and biofilm growth modes and in C. albicans biofilms in response to antifungal agents. Initially, the antifungal susceptibility of C. albicans cultures in different growth modes was evaluated by standard antifungal susceptibility testing. Next, to assess CDR1, CDR2, MDR1, ERG11, FKS1 and PIL1 expression, RNA was harvested from cells in each growth mode, and from biofilms after drug treatment, and subjected to quantitative real-time RT-PCR (qRT-PCR). Biofilm C. albicans was more resistant to antifungals than recently adhered cells and stationary-phase planktonic cultures. Transcriptional expression of CDR1, CDR2, MDR1, ERG11 and FKS1 was lower in recently adhered C. albicans than in the stationary-phase planktonic cultures. In contrast, PIL1 levels were significantly increased in recently adhered and biofilm modes of growth. The expression of MDR1 in biofilms greatly increased on challenge with amphotericin B but not with the other drugs tested (PERG11 was significantly upregulated by ketoconazole (PCandida biofilms, and lay a foundation for future large-scale genome-wide expression analysis. PMID:21474609

  7. Molecular epidemiology and in-vitro antifungal susceptibility of Aspergillus terreus species complex isolates in Delhi, India: evidence of genetic diversity by amplified fragment length polymorphism and microsatellite typing.

    Shallu Kathuria

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

  8. BSAC standardized disc susceptibility testing method (version 8).

    Andrews, J M


    azithromycin, clarithromycin, erythromycin and telithromycin (Table 15); clarithromycin and erythromycin MIC and zone diameter BPs for Moraxella catarrhalis (Table 16); azithromycin MIC BPs for Neisseria gonorrhoeae (Table 17); chloramphenicol and rifampicin MIC BPs for Neisseria meningitidis (Table 18); azithromycin MIC BPs for Haemophilus influenzae (Table 19); MIC BPs for metronidazole for Bacteroides fragilis, Bacteroides thetaiotaomicron and Clostridium perfringens (Tables 23-25, respectively); susceptibility testing of Listeria spp. (Appendix 3); the acceptable range for ATCC 25923 to a 10 microg tobramycin disc (Table 26). PMID:19587067

  9. 21 CFR 866.1700 - Culture medium for antimicrobial susceptibility tests.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Culture medium for antimicrobial susceptibility tests. 866.1700 Section 866.1700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND....1700 Culture medium for antimicrobial susceptibility tests. (a) Identification. A culture medium...

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

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


    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. PMID:26297016

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

    Deepa Gupta


    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.

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

    Gupta, Deepa; Jain, D K


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

  13. Test of Fuzzy Logic Rules for Landslide Susceptibility Assessment

    Thiery, Yannick; Malet, Jean-Philippe; Maquaire, Olivier


    Landslide Susceptibility Assessment (LSA) is defined as the spatial probability for a landslide to be generated in an area for many environmental factors. Currently, two approaches are used: (i) the qualitative approach based on expert opinion and knowledge of the relationship between the observed phenomenon and some predisposing factors and (ii) the statistical approach based on the statistical analysis of the relationship between the observed landslide and some predisposing factors. This pa...

  14. Use of a constant deflection test to evaluate susceptibility to irradiation-assisted stress corrosion cracking

    A constant deflection test was developed to evaluate the susceptibility of irradiated stainless steel (SS) to irradiation-assisted stress corrosion cracking. The test was shown useful in supplementing constant extension rate tensile or slow strain rate tensile, constant load, and swelling mandrel tests that have been used in the past. Preliminary data showing the susceptibility of commercial-purity type 304 SS (UNS S30400) as a function of stress, strain, and fast neutron fluence (E > 1 MeV) were presented

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

    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

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

    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...

  17. Susceptibility testing of sequential isolates of Aspergillus fumigatus recovered from treated patients.

    Danaoui, E.; Meletiadis, J.; Tortorano, A.M.; Symoens, F.; Nolard, N.; Viviani, M.A.; Piens, M.A.; Lebeau, B.; Verweij, P.E.; Grillot, R.


    Two-hundred sequential Aspergillus fumigatus isolates recovered from 26 immunocompromised patients with invasive aspergillosis or bronchial colonization were tested for their in vitro susceptibility to posaconazole, itraconazole, voriconazole, terbinafine and amphotericin B. Twenty-one patients were

  18. 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

    Jorge A Horta


    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.

  19. 抗真菌药物治疗外阴阴道念珠菌病敏感性的临床研究%Clinical Research of Susceptibility to Antifungal Agents in the Treatment of Vulvovaginal Candidiasis



    目的 探讨外阴阴道念珠菌病(VVC)的临床特征及抗真菌药物治疗VVC的敏感性.方法 对我院自2008年1月至2011年8月收治的1000例妇科门诊患者的VVC发病情况进行回顾性分析,观察念珠菌对抗真菌药物的敏感性.结果 通过分离1000株念珠菌,白念珠菌为610例(61%),非白念珠菌为390例(39%).白念珠菌及非白念珠菌对氟康唑和伊曲康唑的敏感度比较差异有统计学意义(P<0.05);对酮康唑和两性霉素B的敏感度比较,差异无统计学意义(P>0.05).结论 白念珠菌是VVC的主要致病菌,非白念珠菌的药物敏感性较白念珠菌低,白念珠菌对抗真菌药物的耐药性不常见.%Objective To discuss the clinical features of vulvovaginal candidiasis( VVC )and the susceptibility to antifungal agents in the treatment. Methods Retrospective analysis of VVC incidence of 1000 gynecological outpatients of our hospital from January 2008 to August 2011 was done, Candida albicans sensitivity to antifungal agents was observed. Results Among the 1000 cases,610 patients( 61% )had Candida albicans,and 390 patients( 39% )had non-Candida albicans. Sensitivity of Candida albicans and non-Candida albicans to fluconazole and itraconazole werestatistically significantly different^ P 0. 05 ). Conclusion The main pathogen of VCC is Candida albicans, non-Candida albicans drug sensitivity is lower than Candida albicans, antifungal drug resistance is not common in Candida albicans.

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

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


    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 to determ....... 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....

  1. A preliminary study on radiation treatment of chitosan for enhancement of antifungal activity tested on fruit - spoiling strains

    Chitosan samples were irradiated at doses ranging from 20 to 200 kGy, and then were supplemented to liquid medium for growth of fungi. Method of fungal cultivation using liquid medium showed that it has higher sensitivity compared with the cultivation on agar plate. Our study indicated that degree of deacetylation of chitosan clearly affects its antifungal activity, the higher the deacetylation of chitosan, stronger antifungal activity can be observed. Radiation treatment at doses higher than 20 kGy increased clearly the antifungal activity of chitosan. In addition, dose of 60-75 kGy where the viscosity-average molecular weight reduced to 110,000, expressed the highest activity. (author)

  2. Antifungal Activity of C-27 Steroidal Saponins

    Yang, Chong-Ren; Zhang, Ying; Jacob, Melissa R.; Khan, Shabana I.; Zhang, Ying-Jun; Li, Xing-Cong


    As part of our search for new antifungal agents from natural resources, 22 C-27 steroidal saponins and 6 steroidal sapogenins isolated from several monocotyledonous plants were tested for their antifungal activity against the opportunistic pathogens Candida albicans, Candida glabrata, Candida krusei, Cryptococcus neoformans, and Aspergillus fumigatus. The results showed that the antifungal activity of the steroidal saponins was associated with their aglycone moieties and the number and struct...

  3. Antifungal activity of triterpenoid isolated from Azima tetracantha leaves

    The present study was designed to evaluate the antifungal activity of Azima tetracantha extracts and isolated compound (friedelin) against fungi. Antifungal activity was carried out using broth micro dilution method and fractions were collected using (silica gel) column chromatography. The antifungal activity of Azima tetracantha crude extracts and isolated compound (friedelin) were evaluated using the micro dilution method. Hexane extract showed some antifungal activity. The compound also exhibited antifungal activity against tested fungi. The lowest MIC against Trichophyton rubrum (296) was 62.5 micro g/ml and the MIC for Curvularia lunata was 62.5 micro g/ml. These results suggest that Friedelin is a promising antifungal agent. (authors)

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

    D.T. Quach


    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.

  5. Effect of physiological heterogeneity of E. coli population on antibiotic susceptivity test


    According to the instantaneous growth rate (dN/dt) of E. coli CVCC249 growing in batch culture, the entire growth progress was distinguished into four phases: accelerating growth phase, constant growth phase, decelerating growth phase and declining phase, in each of which obvious variation in physiological and biochemical properties was detected, including total DNA, total protein, and MTT-dehydrogenase activity, etc., that led to difference in their antibiotic susceptivity. Antibiotic susceptivity of the population sampled from each phase was tested by Concentration-killing Curve (CKC) approach following the formula N=N0/{1+exp[r((x-BC50)]}, showing as normal distribution at the individual cell level for an internal population, in which the median bactericidal concentration BC50 represents the mean level of susceptivity, while the bactericidal span BC1-99=(2lnN0)/r indicates the variation degree of the antibiotic susceptivity. Furthermore, tested by CKC approach, the antibiotic susceptivity of E. coli CVCC249 population in each physiological phase to gentamicin or enoxacin was various: susceptivity of the population in the constant growth phase and declining phase all increased compared with that in the accelerating growth phase for gentamicin but declined for enoxacin. The primary investigations revealed that the physiological phase should be taken into account in the context of antibiotic susceptivity and research into antimicrobial mechanism. However there are few reports concerned with this study. Further research using different kinds of antibiotics with synchronized continuous culture of different bacterial strains is required.

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

    Quach, D T; Sakoulas, G; Nizet, V; Pogliano, J; Pogliano, K


    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. PMID:26981574

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

    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

  8. 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

    Gismari Miranda da Silva


    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.

  9. Antimicrobial susceptibility testing of Clostridium difficile using EUCAST epidemiological cut-off values and disk diffusion correlates

    Erikstrup, L T; Hall, Vanessa Jane; Kahlmeter, G;


    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 ...

  10. Antifungal agents.

    Ryder, N S


    At this year's ICAAC Meeting, new data on approximately 20 different antifungal agents were presented, while no new agents were disclosed. Drugs in late development include the triazoles, voriconazole (Pfizer Ltd) and Sch-56592 (Schering-Plough Corp), and the echinocandins, caspofungin (Merck & Co Inc) and FK-463 (Fujisawa Pharmaceutical Co Ltd). In contrast to previous years, presentations on these and earlier developmental compounds were relatively modest in scope, with few significant new data. Little new information appeared on the most recent novel class of agents, the sordarins (Glaxo Wellcome plc). Early clinical results were presented for FK-463, showing acceptable tolerability and dose-dependent efficacy in AIDS-associated esophageal candidiasis. A new liposomal formulation of nystatin (Nyotran; Aronex Pharmaceuticals Inc) was shown to be equivalent to conventional amphotericin B in empiric therapy of presumed fungal infection in neutropenic patients, but with reduced toxicity. Intravenous itraconazole (Janssen Pharmaceutica NV) was an effective prophylactic therapy in invasive pulmonary aspergillosis, while oral itraconazole was discussed as a treatment for fungal infection in heart and liver transplant patients. The allylamine compound, terbinafine (Novartis AG), showed good clinical efficacy against fungal mycetoma, a serious tropical infection. A major highlight was the first presentation of inhibitors of fungal efflux pumps as a strategy for overcoming resistance. MC-510027 (milbemycin alpha-9; Microcide Pharmaceuticals Inc) and its derivatives, potentiated the antifungal activity of triazoles and terbinafine in a number of Candida spp. Another pump inhibitor, MC-005172 (Microcide Pharmaceuticals Inc) showed in vivo potentiation of fluconazole in a mouse kidney infection model. Microcide Pharmaceuticals Inc also presented inhibitors of bacterial efflux pumps. PMID:16113946

  11. Accelerated electrochemical test of 14Kh17N2 steel susceptibility to ICC

    Description of the accelerated electrochemical technique used to determine susceptibility 14Kh17N2 steel of ferrite-martensite type to intercrystallite corrosion under the drop of electrolyte, is given. Convergence of the results obtained due to accelerated techniques with those of tests using the All-Union Standards 6032-84 constitutes 95%. These results demonstrate possibility to use data of the accelerated techniques for rapid estimation of susceptibility to ICC of martensite-ferrite steel-14Kh17N2

  12. Multicenter Evaluation of a Nonweekend Reading Schedule for Radiometric Pyrazinamide Susceptibility Testing of Mycobacterium tuberculosis

    Madison, B.; Gross, W.; George, I.; Sloutsky, A.; Washabaugh, G.; Robinson-Dunn, B.; Lipman, H; Metchock, B; Mazurek, G; Ridderhof, J.


    Pyrazinamide (PZA) is an integral component of the short-course chemotherapy regimen for tuberculosis. The BACTEC 460TB PZA susceptibility test for Mycobacterium tuberculosis with a daily (D) reading schedule has been available for more than 10 years, but weekend laboratory staffing is necessary. A nonweekend (NW) reading schedule has not been validated in a multicenter study. This prospective multicenter study compares the interlaboratory reproducibility of PZA susceptibility results by foll...

  13. Comparison of an Automated System with Conventional Identification and Antimicrobial Susceptibility Testing

    Shalini Duggal; Rajni Gaind; Neha Tandon; Manorama Deb; Tulsi Das Chugh


    The present study was designed to compare a fully automated identification/antibiotic susceptibility testing (AST) system BD Phoenix (BD) for its efficacy in rapid and accurate identification and AST with conventional manual methods and to determine if the errors reported in AST, such as the (very major errors) VME (false susceptibility), (major errors) ME (false resistance), and (minor errors) MiE (intermediate category interpretation) were within the range certified by FDA. Identification a...

  14. 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

    Jéssica Moreira BATISTA


    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

  15. A Counselling Model for BRCA1/2 Genetic Susceptibility Testing

    van Oostrom Iris


    Full Text Available Abstract When BRCA1/2 genetic susceptibility testing was introduced in the clinic in the mid-nineties, the "Huntington protocol" was used in the counselling of individuals applying for genetic testing. This protocol includes at least three sessions with a certain reflection period before blood sampling. Evidence on the psychological impact of BRCA1/2 genetic susceptibility testing has been accumulating in the last years. We will give a short overview of these psychological studies in order to reflect the need of using the extensive Huntington protocol in the counselling of individuals applying for BRCA1/2 genetic susceptibility testing. A shortened and more flexible BRCA1/2 counselling protocol is delineated, in which the attention is focused on the needs and strengths of the individual.

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

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


    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. Genet

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

    Miller, R.A.; Walker, R.D.; Carson, J.; Coles, M.; Coyne, R.; Dalsgaard, Inger; Gieseker, C.; Hsu, H.M.; Mathers, J.J.; Papapetropoulou, M.; Petty, B.; Teitzel, C.; Reimschuessel, R.


    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...

  18. Impact of New Antifungal Breakpoints on Antifungal Resistance in Candida Species

    Fothergill, Annette W.; Sutton, Deanna A.; McCarthy, Dora I.; Wiederhold, Nathan P.


    We reviewed our antifungal susceptibility data for micafungin, anidulafungin, fluconazole, and voriconazole against Candida species and compared resistance rates determined by the previous and recently revised CLSI antifungal breakpoints. With the new breakpoints, resistance was significantly increased for micafungin (from 0.8% to 7.6%), anidulafungin (from 0.9% to 7.3%), and voriconazole (from 6.1% to 18.4%) against Candida glabrata. Resistance was also increased for fluconazole against Cand...

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

    Petersen, A.; Aarestrup, Frank Møller; Hofshagen, Merete; Sipila, H.; Franklin, A.; Gunnarsson, E.


    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...... reported as vancomycin resistant. Ten laboratories identified the Enterococcus spp. to species level. All five Enterococcus faecium and 10 Enterococcus faecalis selected from the strain collection at the Danish Veterinary Institute were correctly identified by all laboratories, whereas some problems were...

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

    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


    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. PMID:25979598

  1. In vitro antifungal activity of four medicinal plants used in Iranian Traditional Medicine

    S. J. Hashemi; J. Asgarpanah; Z. Alaee; Sadeghian, S.; Hasani, H.; A. Azimi


    Evaluating the in vitro antifungal activity of Phlomis lanceolata, Rhynchocorys elephas, Otostegia persica and Eremurus persicus, four species used in Iranian Traditional Medicine, has been performed on the clinical isolates of the pathogenic fungi Aspergillus fumigatus, A. flavus, Trichophyton mentagrophytes, T. rubrum, T. verrucosum, Microsporum canis, M. gypseum and Epidermophyton floccosum and the yeast Candida albicans. The susceptibility tests were done by agar disc diffusion method and...

  2. Evaluation of a direct blood culture disk diffusion antimicrobial susceptibility test.

    Doern, G V; Scott, D R; Rashad, A L; Kim, K S


    A total of 556 unique blood culture isolates of nonfastidious aerobic and facultatively anaerobic bacteria were examined by direct and standardized disk susceptibility test methods (4,234 antibiotic-organism comparisons). When discrepancies which could be accounted for by the variability inherent in disk diffusion susceptibility tests were excluded, the direct method demonstrated 96.8% overall agreement with the standardized method. A total of 1.6% minor, 1.5% major, and 0.1% very major discrepancies were noted. PMID:7325634

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

    Poojary A


    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.

  4. Antibiotic Susceptibility Testing of the Gram-Negative Bacteria Based on Flow Cytometry.

    Saint-Ruf, Claude; Crussard, Steve; Franceschi, Christine; Orenga, Sylvain; Ouattara, Jasmine; Ramjeet, Mahendrasingh; Surre, Jérémy; Matic, Ivan


    Rapidly treating infections with adequate antibiotics is of major importance. This requires a fast and accurate determination of the antibiotic susceptibility of bacterial pathogens. The most frequently used methods are slow because they are based on the measurement of growth inhibition. Faster methods, such as PCR-based detection of determinants of antibiotic resistance, do not always provide relevant information on susceptibility, particularly that which is not genetically based. Consequently, new methods, such as the detection of changes in bacterial physiology caused by antibiotics using flow cytometry and fluorescent viability markers, are being explored. In this study, we assessed whether Alexa Fluor® 633 Hydrazide (AFH), which targets carbonyl groups, can be used for antibiotic susceptibility testing. Carbonylation of cellular macromolecules, which increases in antibiotic-treated cells, is a particularly appropriate to assess for this purpose because it is irreversible. We tested the susceptibility of clinical isolates of Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, to antibiotics from the three classes: β-lactams, aminoglycosides, and fluoroquinolones. In addition to AFH, we used TO-PRO®-3, which enters cells with damaged membranes and binds to DNA, and DiBAC4 (3), which enters cells with depolarized membranes. We also monitored antibiotic-induced morphological alterations of bacterial cells by analyzing light scattering signals. Although all tested dyes and light scattering signals allowed for the detection of antibiotic-sensitive cells, AFH proved to be the most suitable for the fast and reliable detection of antibiotic susceptibility. PMID:27507962

  5. Comparison of Disk Diffusion and Agar Dilution Methods for Erythromycin and Ciprofloxacin Susceptibility Testing of Campylobacter jejuni subsp. jejuni▿

    Gaudreau, Christiane; Girouard, Yves; Ringuette, Louise; Tsimiklis, Catherine


    Disk diffusion was a reliable, easy, and inexpensive method for testing the susceptibility of Campylobacter jejuni to erythromycin (215 susceptible and 45 resistant isolates) and to ciprofloxacin (154 susceptible, two intermediate, and 124 resistant isolates) using, respectively, an erythromycin disk and ciprofloxacin and nalidixic acid disks.

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

    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.

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

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


    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 isol...

  8. Modified broth-disk method for testing the antibiotic susceptibility of anaerobic bacteria.

    Wilkins, T D; Thiel, T


    The most commonly used method for testing the antibiotic susceptibility of aerobic and facultative bacteria is the disk diffusion method. However, some anaerobic bacteria do not grow well enough in anaerobic jars for performance of disk diffusion tests. A modification of the broth-disk method of Schneierson allowed us to determine antibiotic susceptibility in a completely anaerobic environment. Commercial antibiotic disks were added anaerobically to tubes of prereduced brain heart infusion broth to achieve a concentration of each antibiotic approximating that attainable in blood. The tubes were then inoculated and incubated for 18 h. Resistance or susceptibility to each antibiotic was determined according to the amount of growth in each tube as compared with a control culture without the antibiotic. There was good correlation between results obtained by this broth-disk method and minimal inhibitory concentrations. PMID:4790595

  9. Negative temperament as a moderator of intervention effects in infancy: testing a differential susceptibility model.

    Anzman-Frasca, Stephanie; Stifter, Cynthia A; Paul, Ian M; Birch, Leann L


    A consideration of potential moderators can highlight intervention effects that are attenuated when investigating aggregate results. Differential susceptibility is one type of interaction, where susceptible individuals have poorer outcomes in negative environments and better outcomes in positive environments, compared to less susceptible individuals, who have moderate outcomes regardless of environment. In the current study, we provide rationale for investigating this type of interaction in the context of a behavioral childhood obesity preventive intervention and test whether infant negativity moderated intervention effects on infant self-regulation and weight gain and on two aspects of mothers' parenting competence: parenting self-efficacy and parenting satisfaction. Results showed that infants' negative temperament at 3 weeks moderated intervention effects on some, but not all, outcomes. The intervention led to greater parenting satisfaction in mothers with highly negative infants but did not affect parenting satisfaction in mothers with less negative infants, consistent with a model of differential susceptibility. There was also a trend toward less weight gain in highly negative intervention group infants. In contrast, there was a main effect of the intervention on infant self-regulation at 1 year, such that the intervention group had higher observed self-regulation, across levels of infant negativity. Results support the importance of incorporating tests of moderation into evaluations of obesity interventions and also illustrate that individuals may be differentially susceptible to environmental effects on some outcomes but not others. PMID:23832637

  10. Susceptibility testing of Propionibacterium acnes comparing agar dilution with E test.

    Smith, M.A.; Alperstein, P; France, K.; Vellozzi, E M; Isenberg, H D


    Propionibacterium acnes has been identified as a significant agent of nosocomial infections, including endophthalmitis. Data concerning susceptibility of P. acnes to newer beta-lactam antibiotics and fluoroquinolones are limited. Recent reports suggest that quinolones have activity against these organisms sufficient to warrant further study. We undertook a study to select appropriate antimicrobial agents for use in a rabbit model of P. acnes endophthalmitis. We compared the antibiotic suscept...

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

    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 14C-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

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

    N Karabulut


    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.

  13. Agar diffusion tests with cefuroxime disks for predicting ceftriaxone susceptibility among isolates of Streptococcus pneumoniae

    Dias Cícero A.G.


    Full Text Available The performance of agar diffusion tests using disks of cefuroxime (30µg for predicting ceftriaxone susceptibility in 33 isolates of Streptococcus pneumoniae was studied. All 7 resistant isolates to ceftriaxone (MIC ³1.0 µg/ml exhibited zones of inhibition <28mm. The procedure can be easily adapted to clinical laboratories.

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

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


    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 ...

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

    Creagh, S


    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).

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

    Dalsgaard, Inger

    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...

  17. Evaluation of Ciprofloxacin as a Representative of Veterinary Fluoroquinolones in Susceptibility Testing

    Riddle, Christa; Lemons, Carol L.; Papich, Mark G.; Altier, Craig


    Currently in veterinary medicine, ciprofloxacin is often used in susceptibility testing to represent the entire class of fluoroquinolone antimicrobials. Using quality control organisms as well as clinical isolates, we compared the MIC of ciprofloxacin to those of three other fluoroquinolones used in animals and found that ciprofloxacin is not an adequate representative of other members of this class.

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

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


    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/clavulanic acid, cefoxitin, clindamycin, imipenem, metronidazole, moxifloxacin, piperacillin/tazobactam, tigecycline by agar dilution method previously. The inhibition zones of the same antibiotics including meropenem disc were determined by the disc diffusion on Brucella blood agar supplemented with haemin and vitamin K1. Plates were incubated at 37 °C in an anaerobic atmosphere for 24 h. The zone diameters were read at 100% inhibition. In case of discrepant results MICs were determined by gradient test and compared with the inhibition zones on the same plate. We found a good agreement between the inhibition zone diameters and the MICs for imipenem, metronidazole, moxifloxacin and tigecyclin. The inhibition zone diameters of meropenem also separated clearly the isolates, which can be considered wild-type isolates. In case of amoxicillin/clavulanic acid and piperacillin/tazobactam intermediate and susceptible isolates according to the MIC determination, overlap during the zone diameter determination. Isolates with an inhibition zone disk diffusion can be an option for susceptibility testing of B. fragilis group isolates for most relevant antibiotics in routine laboratories. PMID:25464140

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

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


    -Hinton broth. These QC ranges were accepted by the CLSI/NCCLS Subcommittee on Veterinary Antimicrobial Susceptibility Testing in January 2004. This broth microdilution testing method represents the first standardized method for determining MICs of bacterial isolates whose preferred growth temperatures......A multiple laboratory study was conducted in accordance with the standards established by the Clinical and Laboratory Standards Institute (CLSI), formerly the National Committee for Clinical Laboratory Standards (NCCLS), for the development of quality control (QC) ranges using dilution...... 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...

  20. Antifungal activity of topical microemulsion containing a thiophene derivative

    Geovani Pereira Guimarães


    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.

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

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


    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...... published breakpoint (<23 mm) and five isolates had a vancomycin zone diameter below the published breakpoint (<19 mm), most of which were polymerase chain reaction (PCR) ribotype 027. The total number of PCR ribotype 027 was 29 (1.1 %). Overall, C. difficile PCR ribotype 027 isolates had smaller zone...... diameters than non-027 isolates. The disc diffusion method is very simple and inexpensive, and the published zone diameter breakpoints will detect C. difficile isolates with reduced susceptibility to metronidazole and vancomycin....

  2. Antimicrobial Susceptibility Testing of Acinetobacter spp. by NCCLS Broth Microdilution and Disk Diffusion Methods

    Swenson, Jana M.; Killgore, George E.; Tenover, Fred C.


    Although both broth microdilution (BMD) and disk diffusion (DD) are listed by NCCLS as acceptable methods for testing Acinetobacter spp. for antimicrobial susceptibility, few studies have compared the results generated by the two methods. We tested 196 isolates of Acinetobacter spp. from nine U.S. hospitals and from the Centers for Disease Control culture collection by using BMD and DD and clinically appropriate antimicrobial agents. Categorical results for amikacin, ciprofloxacin, gatifloxac...

  3. Antifungal Activity of Ellagic Acid In Vitro and In Vivo.

    Li, Zhi-Jian; Guo, Xin; Dawuti, Gulina; Aibai, Silafu


    Ellagic acid (EA) has been shown to have antioxidant, antibacterial, and anti-inflammatory activities. In Uighur traditional medicine, Euphorbia humifusa Willd is used to treat fungal diseases, and recent studies suggest that it is the EA content which is responsible for its therapeutic effect. However, the effects of EA on antifungal activity have not yet been reported. This study aimed to investigate the inhibitory effect of EA on fungal strains both in vitro and in vivo. The minimal inhibitory concentration (MIC) was determined by the National Committee for Clinical Laboratory Standards (M38-A and M27-A2) standard method in vitro. EA had a broad spectrum of antifungal activity, with MICs for all the tested dermatophyte strains between 18.75 and 58.33 µg/ml. EA was also active against two Candida strains, with MICs between 25.0 and 75.0 µg/ml. It was inactive against Candida glabrata. The susceptibility of six species of dermatophytes to EA was comparable with that of the commercial antifungal, fluconazole. The most sensitive filamentous species was Trichophyton rubrum (MIC = 18.75 µg/ml). Studies on the mechanism of action using an HPLC-based assay and an enzyme linked immunosorbent assay showed that EA inhibited ergosterol biosynthesis and reduced the activity of sterol 14α-demethylase P450 (CYP51) in the Trichophyton rubrum membrane, respectively. An in vivo test demonstrated that topical administration of EA (4.0 and 8.0 mg/cm(2) ) significantly enhanced the cure rate in a guinea-pig infection model of Trichophyton rubrum. The results suggest that EA has the potential to be developed as a natural antifungal agent. PMID:25919446

  4. Direct antimicrobial drug susceptibility testing of Mycobacterium tuberculosis by the radiometric method

    Direct-drug-susceptibility tests were performed on clinical specimens positive for acid-fast bacilli by either Ziehl-Neelsen or fluorochrome staining. The results of conventional agar dilution and a modified radiometric (BACTEC) method were compared. A total of 580 smear-positive specimens were tested by the BACTEC method at three separate sites. Three hundred and seventy-seven of these were culture positive for M. tuberculosis, and 343 (91%) yielded acceptable direct-susceptibility-test results. We used the conventional method to determine that 343 of 519 smear-positive specimens were culture positive for M. tuberculosis, and 212 (62%) produced acceptable results within 3 wks. Conventional results were reported in 3-4 wks, while the time required to obtain results with the BACTEC method ranged from 5 to 21 days (average 11.5 days). Results indicate that the radiometric method provides reportable results more frequently with time savings as compared to the conventional method

  5. Synthesis of Pyridazinonethiadiazoles as Possible Antifungal Agents


    Several 5-[1-aryl-1,4-dihydro-6-methylpyridazin-4-one-3-yl]-2-arylamino-1,3,4-thia diazoles were synthesized.The preliminary bio-active test shows that these compounds exhibit high antifungal activity.

  6. A rapid antimicrobial susceptibility test based on single-cell morphological analysis.

    Choi, Jungil; Yoo, Jungheon; Lee, Mincheol; Kim, Eun-Geun; Lee, Ji Soo; Lee, Seungok; Joo, Seik; Song, Sang Hoon; Kim, Eui-Chong; Lee, Jung Chan; Kim, Hee Chan; Jung, Yong-Gyun; Kwon, Sunghoon


    A rapid antibiotic susceptibility test (AST) is desperately needed in clinical settings for fast and appropriate antibiotic administration. Traditional ASTs, which rely on cell culture, are not suitable for urgent cases of bacterial infection and antibiotic resistance owing to their relatively long test times. We describe a novel AST called single-cell morphological analysis (SCMA) that can determine antimicrobial susceptibility by automatically analyzing and categorizing morphological changes in single bacterial cells under various antimicrobial conditions. The SCMA was tested with four Clinical and Laboratory Standards Institute standard bacterial strains and 189 clinical samples, including extended-spectrum β-lactamase-positive Escherichia coli and Klebsiella pneumoniae, imipenem-resistant Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococci from hospitals. The results were compared with the gold standard broth microdilution test. The SCMA results were obtained in less than 4 hours, with 91.5% categorical agreement and 6.51% minor, 2.56% major, and 1.49% very major discrepancies. Thus, SCMA provides rapid and accurate antimicrobial susceptibility data that satisfy the recommended performance of the U.S. Food and Drug Administration. PMID:25520395

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

    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


    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. PMID:26324357

  8. Electromagnetic Compatibility Testing for Conducted Susceptibility Along Interconnecting Signal Lines. Final report

    Ewing, P. D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wood, R. T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Korsah, K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shourbaji, A. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, T. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Beets, B. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)


    This document presents recommendations and the associated technical basis for addressing the effects of conducted electromagnetic interference (EMI) and radio-frequency interference (RFI) along interconnecting signal lines in safety-related instrumentation and control (I&C) systems. Oak Ridge National Laboratory has been engaged in assisting the U.S. Nuclear Regulatory Commission Office of Nuclear Regulatory Research in developing the technical basis for regulatory guidance on EMIIRFI immunity and power surge withstand capability (SWC). Previous research efforts have provided recommendations on (1) electromagnetic compatibility design and installation practices, (2) the endorsement of EMI/RFI and SWC test criteria and test methods, (3) the determination of ambient electromagnetic conditions at nuclear power plants, and (4) the development of recommended electromagnetic operating envelopes applicable to locations where safety-related I&C systems will be installed. The current research focuses on the susceptibility of l&C systems to conducted EMIIRFI along interconnecting signal lines. Coverage of signal line susceptibility was identified as an open issue in previous research on establishing the technical basis for EMIIRFI and SWC in safety-related I&C systems. Research results provided in this report will be used to establish the technical basis for endorsing U.S. Department of Defense and European Committee for Electrotechnical Standardization test criteria and test methods that address signal-line susceptibility. In addition, recommendations on operating envelopes are presented based on available technical information.

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

    Ambrose, John R.


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

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


    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...... using routine methodology. In addition, the 25 Enterococcus strains were identified to species level. A total of 22,598 (97.2%) out of 23,259 test results were in accordance when the data were categorized as susceptible or resistant. When the reported results were categorized according to the National...... reported as vancomycin resistant. Ten laboratories identified the Enterococcus spp. to species level. All five Enterococcus faecium and 10 Enterococcus faecalis selected from the strain collection at the Danish Veterinary Institute were correctly identified by all laboratories, whereas some problems were...

  11. Isolation,Identification and Antibiotics Susceptibility Test of Citrobacter freundii from Procambarus clarkia

    Chen; Honglian; Song; Guangtong; He; Jixiang; Hou; Guanjun; Wang; Yongjie


    This experiment was conducted to clarify species and drug resistance of pathogen from the diseased Procambarus clarkia. Pathogenic bacteria from hepatopancreas of the diseased P. clarkia were examined using conventional methods,and then were isolated. The further tests and analysis of the isolated strain were developed,including the regression experiment to P. clarkia,the morphology,physiological and biochemical characteristics,sequence analysis of their 16 S rRNA and gyr B genes,and the susceptibility test to antibiotics. Large colonies with similar morphology and color were obtained. Strain X120523 was identified as Citrobacter freundii,proved to have strong pathogenicity,and was susceptible to quinolones and aminoglycosides.

  12. Assessment of Etest as an Alternative to Agar Dilution for Antimicrobial Susceptibility Testing of Neisseria gonorrhoeae

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


    We studied whether the Etest can be used as an alternative to agar dilution to determine antimicrobial susceptibilities of ceftriaxone, cefixime, and cefpodoxime in Neisseria gonorrhoeae surveillance. One hundred fifteen clinical and laboratory isolates of N. gonorrhoeae were tested following the Clinical Laboratory Improvement Amendments (CLIA)-approved CLSI standard agar dilution method and, separately, by the Etest according to the manufacturer's recommendations. The MICs were determined a...

  13. Multicenter Evaluation of the MB/BACT System for Susceptibility Testing of Mycobacterium tuberculosis

    Bemer, Pascale; Bodmer, Thomas; Munzinger, Juerg; Perrin, Monique; Vincent, Véronique; Drugeon, Henri


    The reliability of the MB/BACT system for susceptibility testing of Mycobacterium tuberculosis to pyrazinamide, rifampin, isoniazid, streptomycin, and ethambutol was compared to the BACTEC 460TB system. The proportion method was used to resolve discrepant results by an independent arbiter. Two interpretative methods were used, with an undiluted control (direct control) and a diluted control (10−1 control). As no significant difference was observed between the two controls, the method with the...

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

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


    Fluoroquinolone (FQ) resistance in Salmonella enterica is a significant clinical concern. Recognition of resistance by the clinical laboratory is complicated by the multiple FQ resistance mechanisms found in Salmonella. The Clinical Laboratory Standards Institute (CLSI) recently addressed...... 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...

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

    Vincenzo Rondinelli


    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.

  16. Rapid antibiotic susceptibility testing via electrochemical measurement of ferricyanide reduction by Escherichia coli and Clostridium sporogenes.

    Ertl, P; Robello, E; Battaglini, F; Mikkelsen, S R


    Electrochemical measurement of respiratory chain activity allows rapid and reliable screening for antibiotic susceptibility in microorganisms. Chronoamperometry and chronocoulometry of suspensions of aerobically cultivated E. coli combined with the non-native oxidant potassium hexacyanoferrate(III) (ferricyanide) yield signals for reoxidation of the reduction product ferrocyanide that are much smaller if the E. coli has been incubated briefly with an effective antibiotic compound. Chronocoulometric results, obtained following 20-min incubation with antibiotic and 2-min measurement in assay buffer containing 50 mM ferricyanide and 10 mM succinate, at +0.50 V vs Ag/AgCl at a Pt working electrode, were compared with traditional disk diffusion susceptibility testing, which requires overnight incubation on agar plates; the results show significantly lower accumulation of ferrocyanide in all cases in which growth inhibition was observed in the disk diffusion assay. A range of antibiotic compounds (13) were examined that possess different mechanisms of action. Quantitative determination of IC50 values for penicillin G and chloramphenicol yielded values that were 100-fold higher than those obtained by standard turbidity methods after 10-h incubation; this is likely a result of the very brief (10 min) exposure time to the antibiotics. Addition of 5 microM 2,6-dichlorophenolindophenol, a hydrophobic electron-transfer mediator, to the assay mixture allowed susceptibility testing of a Gram-positive obligate anaerobe, Clostridium sporogenes. This rapid new assay will facilitate clinical susceptibility testing, allowing appropriate treatment virtually as soon as a clinical isolate can be obtained. PMID:11055715

  17. Antimicrobial Susceptibility Testing for Escherichia coli Strains to Fluoroquinolones, in Urinary Tract Infections

    FA Nakhjavani


    Full Text Available Background: Urinary Tract Infections (UTIs are one of the most common infectious diseases diagnosed all over the world. Meanwhile most episode of UTIs are caused by Escherichia coli (up to 85% and frequently fluoroquinolones are preferred as initial agents for empiric therapy of UTIs. Widespread use of fluoroquinolones has resulted in an increasing incidence of resistance these agents all over the world. The aim of this study was to assess, susceptibility of Escherichia coli strains from UTI patients against common fluoroquinolones. Methods: Antimicrobial susceptibility testing was determined by disk agar diffusion (DAD and Minimal Inhibitory Concentration methods as described by the National Committee for Clinical Laboratory Standards (NCCLS. Results: One hundred sixty four clinical isolates of E. coli were collected by urine cultures from patients with UTI. The extent of resistant to nalidixic acid, ofloxacin, norfloxacin and ciprofloxacin, by disk diffusion method was 49.3%, 44.5%, 41.4% and 40.2%, respectively. Resistance to ciprofloxacin by MIC method was 4.9%. Conclusion: This study represents high level resistant of E. coli isolates from UTI patients. It is because of inappropriate and incorrect administration of antimicrobial agents in blind cases. This problem remarks significance of performing antimicrobial susceptibility testing before empiric antibiotic therapy. To overcome this problem use of unnecessary antibiotics therapy should be limited.

  18. Direct susceptibility testing for multi drug resistant tuberculosis: A meta-analysis

    Hoffner Sven


    Full Text Available Abstract Background One of the challenges facing the tuberculosis (TB control programmes in resource-limited settings is lack of rapid techniques for detection of drug resistant TB, particularly multi drug resistant tuberculosis (MDR TB. Results obtained with the conventional indirect susceptibility testing methods come too late to influence a timely decision on patient management. More rapid tests directly applied on sputum samples are needed. This study compared the sensitivity, specificity and time to results of four direct drug susceptibility testing tests with the conventional indirect testing for detection of resistance to rifampicin and isoniazid in M. tuberculosis. The four direct tests included two in-house phenotypic assays – Nitrate Reductase Assay (NRA and Microscopic Observation Drug Susceptibility (MODS, and two commercially available tests – Genotype® MTBDR and Genotype® MTBDRplus (Hain Life Sciences, Nehren, Germany. Methods A literature review and meta-analysis of study reports was performed. The Meta-Disc software was used to analyse the reports and tests for sensitivity, specificity, and area under the summary receiver operating characteristic (sROC curves. Heterogeneity in accuracy estimates was tested with the Spearman correlation coefficient and Chi-square. Results Eighteen direct DST reports were analysed: NRA – 4, MODS- 6, Genotype MTBDR® – 3 and Genotype® MTBDRplus – 5. The pooled sensitivity and specificity for detection of resistance to rifampicin were 99% and 100% with NRA, 96% and 96% with MODS, 99% and 98% with Genotype® MTBDR, and 99% and 99% with the new Genotype® MTBDRplus, respectively. For isoniazid it was 94% and 100% for NRA, 92% and 96% for MODS, 71% and 100% for Genotype® MTBDR, and 96% and 100% with the Genotype® MTBDRplus, respectively. The area under the summary receiver operating characteristic (sROC curves was in ranges of 0.98 to 1.00 for all the four tests. Molecular tests were

  19. An Agar Medium Designed for Pyrazinamide Susceptibility Testing Of the Mycobacterium Tuberculosis Strains

    M Najafi Mosleh


    Full Text Available Background: Pyrazinamide (PZA is an important front-line antituberculosis agent. This drug plays a unique role in shortening the therapy, besides of metabolically active and replicating bacilli; it kills a population of semi-dormant organisms that are not killed by other first-line antituberculosis drugs. The activity of PZA correlates with the acidity of the medium, being most active at PH 5.5 less active at PH 6 and inactive at neutral PH. The problem is that such an acidic environment is quite unfavorable for Mycobacterium tuberculosis growth. Therefore the PZA susceptibility testing is difficult and often unreliable because of the acid PH requirement for drug activity. For this reason, many clinical microbiology laboratories do not perform PZA susceptibility testing and most drug-resistance surveys do not have PZA resistance data. For this reason a special condition which could be to support the optimal growth of organisms & allow to performing PZA susceptibility testing at favorable PH has been developed. Methods: The continuously buffered Middlebrook 7H10 agar base with an acidic PH of 6.0 used, to provide optimal conditions for PZA acidity, it also differs from conventional 7H10 medium in that supplemented with animal serum instead of oleic acid to support optimal growth of organism at low PH of 6.0. Individual critical concentrations of PZA were used according to the Hassle- Bausch´s enzyme- substrate activity correlation in this medium made it possible to differentiate between PZA-susceptible and PZA-resistant clinical isolates. Results: During two years survey following results was obtained; approximately 2.6٪ of isolated were identified as PZA-resistance together other drugs resistance, with about 1٪ only PZA-resistance. PZA positive & PZA negative standard strains as control shown the method was used in this study obtains reliable results. Conclusion: Compared to a liquid medium this agar medium also has the following advantages

  20. Patients' understanding of genetic susceptibility testing in mainstream medicine: qualitative study on thrombophilia

    Shepherd Maggie H


    Full Text Available Abstract Background UK and US policy initiatives have suggested that, in the future, patients and clinicians in mainstream medicine could use genetic information to prevent common illnesses. There are no studies on patients' experience and understanding of the process of testing for common genetic susceptibilities in mainstream medicine. Methods Qualitative interviews with 42 individuals who had undergone testing for a genetic susceptibility for deep vein thrombosis in primary and secondary care in the UK. Results Some participants, often from higher social classes, had a good understanding of the test and its implications. They had often sought additional information on thrombophilia from relatives and from the Internet. Others, often from less privileged backgrounds, had a poorer understanding of the test – seven individuals were unaware of having had the genetic test. Features of genetic information led to misunderstandings: (i at referral, (ii when communicating results, and (iii when making sense of the implications of testing. Participants' accounts indicated that non-specialist doctors may feel obliged to refer a patient for a genetic test they know little about, because a patient requests it after a relative had tested positive. Sometimes a referral for a genetic test was lost under information overload when multiple tests and issues were considered. The inconsistent and informal ways of communicating test results – for example by phone – in mainstream medicine also led to confusion. Participants did not generally overestimate their risk, but some were uncertain about whether they were taking the right preventive actions and/or whether their children were at risk. Information about genetic susceptibilities was difficult to make sense of, as it related to ambiguous risks for participants and family members, complicated and unfamiliar terminology and multiple genes and preventive strategies. Conclusion Policy visions of clinicians

  1. Activity of fosfomycin and comparison of several susceptibility testing methods against contemporary urine isolates.

    Hirsch, Elizabeth B; Raux, Brian R; Zucchi, Paola C; Kim, Yisu; McCoy, Christopher; Kirby, James E; Wright, Sharon B; Eliopoulos, George M


    Fosfomycin is recommended as first-line treatment for acute uncomplicated cystitis in women. It has demonstrated in vitro activity against a variety of pathogens; however, a paucity of data are available from the USA. We determined the susceptibility of a collection of urine isolates to fosfomycin and compared multiple methods of susceptibility testing. Consecutive non-duplicate Enterobacteriaceae, enterococci and Pseudomonas aeruginosa isolates were collected from the clinical microbiology laboratory between August 2013 and January 2014. Isolates represented hospitalised or emergency department patients with monomicrobial bacteriuria. Fosfomycin MICs were determined in duplicate, on separate days, by Etest and disk diffusion and results were compared with agar dilution. Nitrofurantoin and ciprofloxacin were used as comparators. MIC results were categorised using Clinical and Laboratory Standards Institute interpretive criteria for Escherichia coli and Enterococcus faecalis. Correlation between the three testing methods was evaluated. Overall susceptibility to fosfomycin was 94.4%, 93.5% and 87.9% by agar dilution, disk diffusion and Etest, respectively. Five fosfomycin-resistant isolates were identified, including two Morganella morganii, one P. aeruginosa, one Proteus mirabilis and one Enterobacter aerogenes. Across all organisms, rates of essential agreement, categorical agreement, minor errors, major errors and very major errors for Etest/disk diffusion compared with agar dilution were 77.3%/NA, 89.5/93.8%, 7.1/5.0%, 3.6/1.3% and 0/0%, respectively. Fosfomycin displayed fairly consistent activity against a majority of isolates collected when using the susceptibility breakpoint of 64 μg/mL. MICs for E. coli were particularly low (≤2 μg/mL). These data lend support to current guidelines that recommend fosfomycin as empirical first-line therapy for uncomplicated UTI. PMID:26498988

  2. Reverberation Chamber Uniformity Validation and Radiated Susceptibility Test Procedures for the NASA High Intensity Radiated Fields Laboratory

    Koppen, Sandra V.; Nguyen, Truong X.; Mielnik, John J.


    The NASA Langley Research Center's High Intensity Radiated Fields Laboratory has developed a capability based on the RTCA/DO-160F Section 20 guidelines for radiated electromagnetic susceptibility testing in reverberation chambers. Phase 1 of the test procedure utilizes mode-tuned stirrer techniques and E-field probe measurements to validate chamber uniformity, determines chamber loading effects, and defines a radiated susceptibility test process. The test procedure is segmented into numbered operations that are largely software controlled. This document is intended as a laboratory test reference and includes diagrams of test setups, equipment lists, as well as test results and analysis. Phase 2 of development is discussed.

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

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


    This paper reports the in vitro antifungal activity of propolis extracts from the province of Tucuman (Argentina) as well as the identification of their main antifungal compounds and botanical origin. The antifungal activity was determined by the microdilution technique, using reference microorganisms and clinical isolates. All dermatophytes and yeasts tested were strongly inhibited by different propolis extracts (MICs between 16 and 125 microg mL(-1)). The most susceptible species were Microsporum gypseum, Trichophyton mentagrophytes, and Trichophyton rubrum. The main bioactive compounds were 2',4'-dihydroxy-3'-methoxychalcone 2 and 2',4'-dihydroxychalcone 3. Both displayed strong activity against clinical isolates of T. rubrum and T. mentagrophytes (MICs and MFCs between 1.9 and 2.9 microg mL(-1)). Additionally, galangin 5, pinocembrin 6, and 7-hydroxy-8-methoxyflavanone 9 were isolated from propolis samples and Zuccagnia punctata exudates, showing moderate antifungal activity. This is the first study matching the chemical profile of Z. punctata Cav. exudates with their corresponding propolis, giving strong evidence on the botanical origin of the studied propolis. PMID:19916546

  4. Direct Susceptibility Testing of Mycobacterium tuberculosis for Pyrazinamide by Use of the Bactec MGIT 960 System

    Demers, Anne-Marie; Venter, Amour; Friedrich, Sven O.; Rojas-Ponce, Gabriel; Mapamba, Daniel; Jugheli, Levan; Sasamalo, Mohammed; Almeida, Deepak; Dorasamy, Afton; Jentsch, Ute; Gibson, Mara; Everitt, Daniel; Diacon, Andreas H.


    Pyrazinamide (PZA) is a key antituberculosis drug, yet no rapid susceptibility test is commercially available. PZA drug susceptibility testing (DST) was performed directly on sputum samples from 327 patients and compared with the indirect method by using the Bactec MGIT 960 system in the context of patient screening for participation in a drug trial. Compared to standard indirect PZA DST, direct DST was successful in only 59% of cases, but results obtained were highly accurate and available faster. Agreement between the direct and indirect methods varied from 90 to 100% in each laboratory. The median times for obtaining PZA results from the time when the specimen was collected ranged from 11 to 16 days for the direct test and 18 to 95 days for the indirect test across laboratories. The direct method is accurate and reproducible across laboratories. It can be expected to accelerate results in >50% of cases, but it cannot replace indirect DST for PZA. Phenotypic methods remain the gold standard for DST in drug trials. If future studies can optimize the method to decrease the number of uninterpretable results, direct MGIT DST could be the new phenotypic DST standard for clinical trials, providing more rapid detection of resistance to new drugs in experimental regimens. PMID:26912751

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



    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.

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

    Arinana; Tsunoda, Kunio; Herliyana, Elis N; Hadi, Yusuf S


    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). PMID:26466532

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

    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

  8. Genetic antimicrobial susceptibility testing in Gram-negative sepsis - impact on time to results in a routine laboratory.

    Kommedal, Øyvind; Aasen, Johanne Lind; Lindemann, Paul Christoffer


    Diagnostic testing of positive blood cultures is among the most critical tasks performed by clinical microbiology laboratories, and the total analysis time from sampling to results should be kept as short as possible. By providing identification of pelleted bacteria directly from positive blood-cultures, MALDI-TOF MS opens for relatively low-complex species-adjusted genetic susceptibility testing from the same bacterial pellet. In our lab routine, we prospectively evaluated a rapid in-house real-time PCR targeting the most common aminoglycoside and cephalosporin resistance genes in Escherichia coli and Klebsiella pneumoniae and measured time to preliminary susceptibility reporting for 138 samples. The results were compared to direct phenotypic susceptibility testing with interpretation after 6 h and overnight incubation respectively. Results from the genetic susceptibility testing were available for 69.5% (96/138) of the positive blood cultures within 24 h after sample collection. No phenotypic susceptibility results were available at this time. Compared to overnight direct susceptibility testing, the average time from sample collection to preliminary susceptibility reporting was reduced with 43%, from 45 h and 5 min to 25 h and 44 min, providing an earlier adjustment of antimicrobial therapy for 12 patients. Minor logistic adjustments have the potential to save yet another 4 h. PMID:27197792

  9. In vitro and in vivo antifungal activity, liver profile test, and mutagenic activity of five plants used in traditional Mexican medicine

    Jorge Cornejo-Garrido


    Full Text Available Berberis hartwegii Benth., Berberidaceae, Hamelia patens Jacq., Rubiaceae, Dendropanax arboreus (L. Decne & Planch., Araliaceae, Erythrina herbacea L., Fabaceae, and Zanthoxylum caribaeum Lam., Rutaceae, acetone extracts were selected on the basis of their use in traditional Mexican medicine to treat scabies or skin diseases. Anti-dermatophyte activity in vitro was evaluated using the agar dilution assay, and the therapeutic efficacy of B. hartwegii and Z. caribaeum were tested against experimental tinea pedis. The infected animals were treated intragastrically daily for seven days with 2.5 and 5 mg/kg of acetone extracts. The acetone extract of H. patens exhibited 100% growth inhibition against T. mentagrophytes and E. floccosum at 100.0 and 50.0 µg/ml, respectively, and B. hartwegii inhibited growth of M. canis and T. mentagrophytes at 100.0 µg/ml. Effective treatments with 2.5 mg/kg of Z. caribaeum and B. hartwegii extract were comparable with 1 mg/kg of clotrimazole in mice. Liver profile tests and histological analyses did not exhibit any signs of toxicity and the Ames test indicated that both extracts were safe when evaluated in strains TA98, TA100 and TA102. Our results suggest the potential for the future development of new antifungal drugs from B. hartwegii or Z. caribaeum.

  10. Antifungals of acromyrmex, allomerus, and tetraponera ant- and cultivarassociated bacteria

    Barke, Joerg


    The central purpose of this thesis is to test the utility of ant-microbe associations for discovering antifungal compounds with novel molecular (sub-) structures. Novel antifungals displaying reduced adverse side-effects, increased water-solubilities, and/or strong fungicidal properties would be helpful in medical science for responding to the rising prevalence of human mycoses and for solving problems with adverse side-effects in currently used antifungal drugs. Host-symbiont systems m...


    P Nilani; Duraisamy, B.; Dhanabal, P.S.; khan, Saleemullah; Suresh, B.; Shankar, V; Kavitha, K.Y.; Syamala, G.


    The in vitro antifungal activity of solvent extracts of Coleus forskohlii, Coleus blumei and Coleus barbatus were compared by testing against some pathogenic fungi like Aspergillus niger, Aspergillus fumigatus, Aspergillus ruantii, Proteus vulgaris and Candida albicans. The petroleum ether extract of Coleus forskohlii and Coleus barbatus exhibited significant antifungal activity against all the selected organisms. The extracts of Coleus blumei did not show any significant antifungal activity ...

  12. Standard Test Method for Determination of the Susceptibility of Metallic Materials to Hydrogen Gas Embrittlement (HGE)

    American Society for Testing and Materials. Philadelphia


    1.1 This test method covers the quantitative determination of the susceptibility of metallic materials to hydrogen embrittlement, when exposed to high pressure gaseous hydrogen. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  13. New Agar Medium for Testing Susceptibility of Mycobacterium tuberculosis to Pyrazinamide

    Heifets, Leonid; Sanchez, Tracy


    A new agar medium to perform pyrazinamide (PZA) susceptibility testing with Mycobacterium tuberculosis has been developed. This medium has an acidic pH of 6.0 instead of the usual for agar media, pH 6.8, to provide optimal conditions for PZA activity, and it also differs from conventional Middlebrook 7H10/7H11 agar in that animal serum (fetal or calf bovine or fetal equine serum) is used instead of oleic acid-albumin-dextrose-catalase to support good growth of M. tuberculosis at the low pH of...

  14. Bedaquiline susceptibility testing of Mycobacterium tuberculosis in an automated liquid culture system

    Torrea, Gabriela; Coeck, Nele; Desmaretz, Christel; Van De Parre, Tim; Van Poucke, Tijs; Lounis, Nacer; de Jong, Bouke C.; Rigouts, Leen


    Abstract: Objectives: The objective of this study was to evaluate the performance of the BACTEC MGIT960 system to test the susceptibility to bedaquiline for Mycobacterium tuberculosis complex. Methods: We determined the quality control (QC) range of bedaquiline using the M. tuberculosis H37Rv reference strain and the epidemiological cut-off (ECOFF) in MGIT960 and on Middlebrook 7H11 agar (M7H11) using 47 strains from bedaquiline treatment-naive patients. The accuracy of MGIT960 was evaluated ...

  15. 我院2009-2011年老年真菌感染菌种分布及其对抗真菌药敏感性分析%Analysis of Species Distribution and Drug Susceptibility to Antifungal Agents in the Aged with Fungal Infection of Our Hospital during 2009-2011

    张慧儿; 裘莉佩


    目的:探讨临床老年患者标本中所分离的假丝酵母菌属的菌种分布及其对临床常用抗真菌药的敏感性,为老年人使用抗真菌药提供参考.方法:对我院2009-2011年从老年体内分离的213例假丝酵母菌进行回顾性分析,分析其菌种分布情况以及对5种抗真菌药的敏感性.结果:在213株假丝酵母菌中,白假丝酵母菌占42.3%(90/213),非白假丝酵母菌占57.7% (123/213);5-氟胞嘧啶、两性霉素B、氟康唑、伊曲康唑和伏立康唑的总敏感率分别为87.8%、100%、93.2%、85.9%和95.9%;90株白假丝酵母菌对上述5种抗真菌药的敏感率分别为93.3%、100%、95.4%、92.2%和96.3%,123株非白假丝酵母菌分别为83.7%、100%、91.6%、81.3%和95.6%.结论:在老年感染假丝酵母菌中最常见的菌种仍是白假丝酵母菌,但其比例较已报道的非老年感染者比例有所下降;白假丝酵母菌对常用抗真菌药仍有较高的敏感性,非白假丝酵母菌的耐药性则高于白假丝酵母菌.%OBJECTIVE: To discuss the species distribution and drug susceptibility to antifungal agent of isolated Candida, and to provide reference for the use of antifungal agent in the aged. METHODS: A total of 213 isolates were collected from our hospital during 2009 — 2011 were analyzed statistically, and the species distribution of Candida and drug resistance to 5 commonly used antifungal agents were analyzed. RESULTS: Among 213 Candida, Candida albicans accounted for 42.3% (90/213) and non-Candida albicans accounted for 57.7% (123/213). The overall percentage of strains susceptible to 5-flucytosine, amphotericin B, flucytosine, itraconazole and voriconazole were 87.8% , 100% , 93.2% , 85.9% and 95.9% , respectively. About 93.3% , 100%, 95.4% , 92.2% and 96.3% of 90 strains of Candida albicans were susceptible to these 5 antifungal agents. The susceptibility rates of 123 non-Candida albicans isolates were 83.7%, 100

  16. Physically-based landslide susceptibility modelling: geotechnical testing and model evaluation issues

    Marchesini, Ivan; Mergili, Martin; Schneider-Muntau, Barbara; Alvioli, Massimiliano; Rossi, Mauro; Guzzetti, Fausto


    We used the software r.slope.stability for physically-based landslide susceptibility modelling in the 90 km² Collazzone area, Central Italy, exploiting a comprehensive set of lithological, geotechnical, and landslide inventory data. The model results were evaluated against the inventory. r.slope.stability is a GIS-supported tool for modelling shallow and deep-seated slope stability and slope failure probability at comparatively broad scales. Developed as a raster module of the GRASS GIS software, r.slope.stability evaluates the slope stability for a large number of randomly selected ellipsoidal potential sliding surfaces. The bottom of the soil (for shallow slope stability) or the bedding planes of lithological layers (for deep-seated slope stability) are taken as potential sliding surfaces by truncating the ellipsoids, allowing for the analysis of relatively complex geological structures. To take account for the uncertain geotechnical and geometric parameters, r.slope.stability computes the slope failure probability by testing multiple parameter combinations sampled deterministically or stochastically, and evaluating the ratio between the number of parameter combinations yielding a factor of safety below 1 and the total number of tested combinations. Any single raster cell may be intersected by multiple sliding surfaces, each associated with a slope failure probability. The most critical sliding surface is relevant for each pixel. Intensive use of r.slope.stability in the Collazzone Area has opened up two questions elaborated in the present work: (i) To what extent does a larger number of geotechnical tests help to better constrain the geotechnical characteristics of the study area and, consequently, to improve the model results? The ranges of values of cohesion and angle of internal friction obtained through 13 direct shear tests corresponds remarkably well to the range of values suggested by a geotechnical textbook. We elaborate how far an increased number of

  17. American Society of Clinical Oncology policy statement update: genetic testing for cancer susceptibility.


    As the leading organization representing cancer specialists involved in patient care and clinical research, the American Society of Clinical Oncology (ASCO) reaffirms its commitment to integrating cancer risk assessment and management, including molecular analysis of cancer predisposition genes, into the practice of oncology and preventive medicine. The primary goal of this effort is to foster expanded access to, and continued advances in, medical care provided to patients and families affected by hereditary cancer syndromes. The 1996 ASCO Statement on Genetic Testing for Cancer Susceptibility set forth specific recommendations relating to clinical practice, research needs, educational opportunities, requirement for informed consent, indications for genetic testing, regulation of laboratories, and protection from discrimination, as well as access to and reimbursement for cancer genetics services. In updating this Statement, ASCO endorses the following principles: Indications for Genetic Testing: ASCO recommends that genetic testing be offered when 1) the individual has personal or family history features suggestive of a genetic cancer susceptibility condition, 2) the test can be adequately interpreted, and 3) the results will aid in diagnosis or influence the medical or surgical management of the patient or family members at hereditary risk of cancer. ASCO recommends that genetic testing only be done in the setting of pre- and post-test counseling, which should include discussion of possible risks and benefits of cancer early detection and prevention modalities. Special Issues in Testing Children for Cancer Susceptibility: ASCO recommends that the decision to offer testing to potentially affected children should take into account the availability of evidence-based risk-reduction strategies and the probability of developing a malignancy during childhood. Where risk-reduction strategies are available or cancer predominantly develops in childhood, ASCO believes that

  18. The First Case of Total Dystrophic Onychomycosis Caused by Aspergillus clavatus Resistant to Antifungal Drugs.

    Falahati, Mehraban; Ghojoghi, Aynaz; Abastabar, Mahdi; Ghasemi, Zeinab; Farahyar, Shirin; Roudbary, Maryam; Hedayati, Mohammad Taghi; Taghizadeh Armaki, Mojtaba; Hoseinnejad, Akbar


    Onychomycosis is a common fungal infection of nails which is mainly caused by dermatophyte species and less often by yeasts and non-dermatophyte molds. We present a case of onychomycosis due to Aspergillus clavatus for the first time worldwide. The patient was an immunocompetent 32-year-old woman who identified with Psoriasis of the nail. The presence of A. clavatus in a nail sample was confirmed using microscopic and culture analysis followed by PCR of the β-tubulin gene. After antifungal susceptibility test, it is revealed that the isolate was resistant to the majority of common antifungal drugs, but finally the patient was treated with itraconazole 200 mg daily. A. clavatus and drug-resistant A. clavatus have not previously been reported from onychomycosis. PMID:26474550

  19. Experimental guinea pig model of dermatophytosis: a simple and useful tool for the evaluation of new diagnostics and antifungals

    Saunte, D.M.; Hasselby, J.P.; Brillowska-Dabrowska, A.;


    The aim of this study was to establish a simple guinea pig model for the purpose of evaluating diagnostic principles and treatment modalities for dermatophytic infections. The following variables were evaluated; pre-treatment of the skin by shaving versus tape stripping, Microsporum canis or Tric....... In conclusion, we established a dermatophytosis animal model, which was proven useful for evaluating diagnostic methods and antifungal susceptibility testing Udgivelsesdato: 2008...... Trichophyton mentagrophytes test strains as etiologic agents, differences in inoculum concentrations, and inoculation with and without occlusion. The course of infection was evaluated clinically by redness and lesion scores and mycologically by microscopy, culture, and histopathology. The applicability of the...... model was evaluated with a recently developed diagnostic pan-dermatophyte PCR and antifungal treatment was tested with an oral solution of itraconazole, 10 mg/kg, once daily during days 3-14 of the test period. Pre-treatment of the skin with a manual razor was for practical reasons preferable to tape...

  20. Constitute and antifungal susceptibility of Candida spp . causing blood-stream infection%血流感染假丝酵母菌菌种构成及其药物敏感性

    徐鸣皋; 丁进亚; 徐娟; 孙洁


    Objective To analyze the constitute and antifungal susceptibility of Candida spp . causing bloodstream infection in a hospital,so as to provide evidence for the prevention and treatment of bloodstream infection caused by Candida spp .Methods Candida spp . isolated from blood specimens of clinical patients in a hospital between 2009 and 2013 were analyzed retrospectively,the high risk factors for Candida bloodstream infection were analyzed. Results A total of 42 isolates of Candida spp . were isolated from blood specimens of 42 patients between 2009 and 2013,the major was Candida parapsilosis (C.parapsilosis ,n =20,47.62%),followed by C.albicans (n =16, 38.10%),C.tropicalis (n=4,9.52%),and C.glabrata(n=2,4.76%).Candida spp .were mainly distributed in emergency intensive care unit(n=11),departments of urologic surgery (n=9)and cardiothoracic surgery(n=8). The venous catheters of 37 patients(88.10%)were isolated the same Candida spp . as blood culture,the average time from indwelling venous catheters to positive culture of blood and catheters were 31 .47 and 33.18 days respec-tively;the percentage of positive culture for blood and catheters both increased with the prolongation of catheteriza-tion (both P < 0.001 ).Susceptibility rates of Candida spp . to fluconazole and voriconazole were 75.00% -100.00%,to amphotericin B were all 100.00%,to itraconazole varied significantly with different species (0 -87.50%).Conclusion The major Candida strains causing bloodstream infection in this hospital is C.parapsilosis , and is related to the use of intravenous catheters,susceptibility rates to fluconazole,amphotericin B,and voricon-azole are all high.%目的:分析某院假丝酵母菌血流感染菌种构成及其对抗真菌药物的敏感性,为临床预防和治疗假丝酵母菌血流感染提供依据。方法回顾性分析2009—2013年该院临床科室送检血标本中检出的假丝酵母菌,并对假丝酵母菌血流感染的高

  1. Comparison of Etest with Modified Broth Microdilution Method for Testing Susceptibility of Aspergillus spp. to Voriconazole

    Serrano, M. C.; Morilla, D.; Valverde, A.; Chávez, M.; Espinel-Ingroff, A.; Claro, R.; Ramírez, M.; Mazuelos, E. Martín


    We compared the Etest with a broth microdilution method, performed according to a modified National Committee for Clinical Laboratory Standards guideline (M38-A), for determining the in vitro susceptibility of 77 isolates of Aspergillus spp. (26 A. fumigatus, 21 A. flavus, 10 A. terreus, 9 A. niger, 5 A. nidulellus, 4 A. glaucus, and 2 A. flavipes isolates). Overall, there was 92.2% agreement between both methods when Etest MICs were read at 24 h and 83.1% agreement when both methods were read at 48 h. When Etest MICs were read at 24 h, the agreement was >90% for all species tested except for A. fumigatus (84.6%). When Etest MICs were read at 48 h, the agreement ranged from 50 to 100%. The poorest agreement was seen with A. glaucus (50%) and A. fumigatus (65%). Where a discrepancy was observed between Etest and the reference method, the Etest MIC was generally higher. The Etest appears to be a suitable alternative procedure for testing the susceptibility of Aspergillus spp. to voriconazole. PMID:14605181

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

    Fredborg, M; Rosenvinge, F S; Spillum, E; Kroghsbo, S; Wang, M; Sondergaard, T E


    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 oCelloScope 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 (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) and extended-spectrum β-lactamase (ESBL) profiles. The net average time-to-result was 108 min, with 95% of the results being available within 180 min. In conclusion, this study strongly indicates that the oCelloScope system holds considerable potential as an accurate and sensitive AST method with short time-to-result, enabling same-day targeted antimicrobial therapy, facilitating antibiotic stewardship and better patient management. A full-scale validation of the oCelloScope system including more isolates is necessary to assess the impact of using it for AST. PMID:26407621

  3. Revisiting the susceptibility testing of Mycobacterium tuberculosis to ethionamide in solid culture medium

    Rajagopalan Lakshmi


    Full Text Available Background & objectives: Increase in the isolation of drug resistant phenotypes of Mycobacterium tuberculosis necessitates accuracy in the testing methodology. Critical concentration defining resistance for ethionamide (ETO, needs re-evaluation in accordance with the current scenario. Thus, re-evaluation of conventional minimum inhibitory concentration (MIC and proportion sensitivity testing (PST methods for ETO was done to identify the ideal breakpoint concentration defining resistance. Methods: Isolates of M. tuberculosis (n=235 from new and treated patients were subjected to conventional MIC and PST methods for ETO following standard operating procedures. Results: With breakpoint concentration set at 114 and 156 µg/ml, an increase in specificity was observed whereas sensitivity was high with 80 µg/ml as breakpoint concentration. Errors due to false resistant and susceptible isolates were least at 80 µg/ml concentration. Interpretation & conclusions: Performance parameters at 80 µg/ml breakpoint concentration indicated significant association between PST and MIC methods.

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

    Bruno Horta Andrade


    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.

  5. Screening antifungal activities of selected medicinal plants.

    Quiroga, E N; Sampietro, A R; Vattuone, M A


    Plants synthesise a vast array of secondary metabolites that are gaining importance for their biotechnological applications. The antifungal activity of the ethanolic extracts of ten Argentinean plants used in native medicine is reported. Antifungal assays included radial growth inhibition, disk and well diffusion assays and growth inhibition by broth dilution tests. The chosen test fungi were yeasts, microfungi and wood-rot causing Basidiomycetes. Extracts of Larrea divaricata, Zuccagnia punctata and Larrea cuneifolia displayed remarkable activity in the assays against the majority of the test fungi. In addition to the former plants, Prosopanche americana also inhibited yeast growth. PMID:11137353

  6. Evaluation of rapid alternative methods for drug susceptibility testing in clinical isolates of Mycobacterium tuberculosis

    Luciano Mengatto


    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.

  7. Drug susceptibility testing of clinical isolates of streptococci and enterococci by the Phoenix automated microbiology system

    Sokeng Gertrude


    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

  8. Towards in vitro DT/DNT testing: Assaying chemical susceptibility in early differentiating NT2 cells.

    Menzner, Ann-Katrin; Abolpour Mofrad, Sepideh; Friedrich, Oliver; Gilbert, Daniel F


    Human pluripotent embryonal carcinoma (NT2) cells are increasingly considered as a suitable model for in vitro toxicity testing, e.g. developmental toxicity and neurotoxicity (DT/DNT) studies, as they undergo neuronal differentiation upon stimulation with retinoic acid (RA) and permit toxicity testing at different stages of maturation. NT2 cells have recently been reported to show specific changes in dielectric resistance profiles during differentiation which can be observed as early as 24h upon RA-stimulation. These observations suggest altered susceptibility to chemicals at an early stage of differentiation. However, chemical susceptibility of early differentiating NT cells has not yet been studied. To address this question, we have established a cell fitness screening assay based on the analysis of intracellular ATP levels and we applied the assay in a large-scale drug screening experiment in NT2 stem cells and early differentiating NT2 cells. Subsequent analysis of ranked fitness phenotypes revealed 19 chemicals with differential toxicity profile in early differentiating NT2 cells. To evaluate whether any of the identified drugs have previously been associated with DT/DNT, we conducted a literature search on the identified molecules and quantified the fraction of chemicals assigned to the FDA (Food and Drug Administration) pregnancy risk categories (PRC) N, A, B, C, D, and X in the hit list and the small molecule library. While the fractions of the categories N and B were decreased (0.81 and 0.35-fold), the classes C, D and X were increased (1.35, 1.47 and 3.27-fold) in the hit list compared to the chemical library. From these data as well as from the literature review, identifying large fractions of chemicals being directly (∼42%) and indirectly associated with DT/DNT (∼32%), we conclude that our method may be beneficial to systematic in vitro-based primary screening for developmental toxicants and neurotoxicants and we propose cell fitness screening in

  9. Sensitization of Candida albicans biofilms to various antifungal drugs by cyclosporine A

    Shinde Ravikumar B


    Full Text Available Abstract Background Biofilms formed by Candida albicans are resistant towards most of the available antifungal drugs. Therefore, infections associated with Candida biofilms are considered as a threat to immunocompromised patients. Combinatorial drug therapy may be a good strategy to combat C. albicans biofilms. Methods Combinations of five antifungal drugs- fluconazole (FLC, voriconazole (VOR, caspofungin (CSP, amphotericin B (AmB and nystatin (NYT with cyclosporine A (CSA were tested in vitro against planktonic and biofilm growth of C. albicans. Standard broth micro dilution method was used to study planktonic growth, while biofilms were studied in an in vitro biofilm model. A chequerboard format was used to determine fractional inhibitory concentration indices (FICI of combination effects. Biofilm growth was analyzed using XTT-metabolic assay. Results MICs of various antifungal drugs for planktonic growth of C. albicans were lowered in combination with CSA by 2 to 16 fold. Activity against biofilm development with FIC indices of 0.26, 0.28, 0.31 and 0.25 indicated synergistic interactions between FLC-CSA, VOR-CSA, CSP-CSA and AmB-CSA, respectively. Increase in efficacy of the drugs FLC, VOR and CSP against mature biofilms after addition of 62.5 μg/ml of CSA was evident with FIC indices 0.06, 0.14 and 0.37, respectively. Conclusions The combinations with CSA resulted in increased susceptibility of biofilms to antifungal drugs. Combination of antifungal drugs with CSA would be an effective prophylactic and therapeutic strategy against biofilm associated C. albicans infections.

  10. Antimicrobial susceptibility testing of Clostridium difficile using EUCAST epidemiological cut-off values and disk diffusion correlates.

    Erikstrup, L T; Danielsen, T K L; Hall, V; Olsen, K E P; Kristensen, B; Kahlmeter, G; Fuursted, K; Justesen, U S


    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 comparing disk diffusion results with MICs from gradient tests and to propose zone diameter breakpoint correlates for the EUCAST epidemiological cut-off values (ECOFFs) recently published. We tested 211 clinical isolates of C. difficile, from patients with diarrhoea hospitalized at Aarhus and Odense 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% of values within 4 mm for vancomycin, and 98% of values within 4 mm for moxifloxacin. With proposed zone diameter breakpoints for metronidazole, vancomycin and moxifloxacin of WT ≥ 23 mm, WT ≥ 19 and WT ≥ 20 mm, respectively, we found no very major errors and only major errors below 2%. In conclusion, we suggest that disk diffusion is an option for antimicrobial susceptibility testing of C. difficile. PMID:22672504