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Sample records for broth microdilution method

  1. Drug susceptibility testing of Mycobacterium tuberculosis by the broth microdilution method with 7H9 broth

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    Ahmet Yilmaz Coban

    2004-02-01

    Full Text Available In this study, we have evaluated the broth microdilution method (BMM for susceptibility testing of Mycobacterium tuberculosis. A total of 43 clinical isolates of M. tuberculosis and H37Rv as a control strain were studied. All isolates were tested by the proportion method and the BMM for isoniazid (INH, rifampicin (RIF, streptomycin (STR, and ethambutol (ETM. The proportion method was carried out according to the National Committee for Clinical Laboratory Standards (NCCLS on Löwenstein-Jensen (LJ medium. The BMM was carried out using 7H9 broth with 96 well-plates. All strains were tested at 3.2-0.05 µg/ml, 16-0.25 µg/ml, 32-0.5 µg/ml, and 32-0.5 µg/ml concentrations for INH, RIF, STR, and ETM, respectively. When the BMM was compared with the proportion method, sensitivity was 100, 100, 96.9, and 90.2%, while specificity was 100, 85.7, 90.9, and 100% for INH, RIF, STR, and ETM, respectively. The plates were examined 7, 10, 14, and 21 days after incubation. The majority of the result were obtained at 14th days after incubation, while the proportion method result were ended in 21-28 days. According to our results, it may be suggested that the BMM is suitable for early determining of multidrug-resistance-M. tuberculosis strains in developed or developing countries.

  2. Evaluation of CLSI agar dilution method and Trek Sensititre broth microdilution panel for determining antimicrobial susceptibility of Streptococcus pneumoniae.

    Science.gov (United States)

    Zhang, Sean X; Rawte, Prasad; Brown, Shirley; Lo, Steven; Siebert, Heather; Pong-Porter, Sylvia; Low, Donald E; Jamieson, Frances B

    2011-02-01

    Both the CLSI agar dilution method and Trek Sensititre broth microdilution panel for Streptococcus pneumoniae antimicrobial susceptibility testing were evaluated against the reference CLSI broth microdilution method using the most recently published CLSI breakpoints. While agar dilution was not an optimal method, the commercial panel appeared to be an acceptable method, with minor errors encountered for ceftriaxone, penicillin, and meropenem.

  3. Evaluation of CLSI Agar Dilution Method and Trek Sensititre Broth Microdilution Panel for Determining Antimicrobial Susceptibility of Streptococcus pneumoniae▿

    OpenAIRE

    Zhang, Sean X.; Rawte, Prasad; Brown, Shirley; Lo, Steven; Siebert, Heather; Pong-Porter, Sylvia; Low, Donald E; Frances B Jamieson

    2011-01-01

    Both the CLSI agar dilution method and Trek Sensititre broth microdilution panel for Streptococcus pneumoniae antimicrobial susceptibility testing were evaluated against the reference CLSI broth microdilution method using the most recently published CLSI breakpoints. While agar dilution was not an optimal method, the commercial panel appeared to be an acceptable method, with minor errors encountered for ceftriaxone, penicillin, and meropenem.

  4. Recommendation for a Standardised Method of Broth Microdilution Susceptibility Testing for Porcine Bordetella bronchiseptica.

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    Sandra Prüller

    Full Text Available The objective was to establish and standardise a broth microdilution susceptibility testing method for porcine Bordetella (B. bronchiseptica. B. bronchiseptica isolates from different geographical regions and farms were genotyped by macrorestriction analysis and subsequent pulsed-field gel electrophoresis. One reference and one type strain plus two field isolates of B. bronchiseptica were chosen to analyse growth curves in four different media: cation-adjusted Mueller-Hinton broth (CAMHB with and without 2% lysed horse blood, Brain-Heart-Infusion (BHI, and Caso broth. The growth rate of each test strain in each medium was determined by culture enumeration and the suitability of CAMHB was confirmed by comparative statistical analysis. Thereafter, reference and type strain and eight epidemiologically unrelated field isolates of B. bronchiseptica were used to test the suitability of a broth microdilution susceptibility testing method following CLSI-approved performance standards given in document VET01-A4. Susceptibility tests, using 20 antimicrobial agents, were performed in five replicates, and data were collected after 20 and 24 hours incubation and statistically analysed. Due to the low growth rate of B. bronchiseptica, an incubation time of 24 hours resulted in significantly more homogeneous minimum inhibitory concentrations after five replications compared to a 20-hour incubation. An interlaboratory comparison trial including susceptibility testing of 24 antimicrobial agents revealed a high mean level of reproducibility (97.9% of the modified method. Hence, in a harmonization for broth microdilution susceptibility testing of B. bronchiseptica, an incubation time of 24 hours in CAMHB medium with an incubation temperature of 35°C and an inoculum concentration of approximately 5 x 10(5 cfu/ml was proposed.

  5. Recommendation for a Standardised Method of Broth Microdilution Susceptibility Testing for Porcine Bordetella bronchiseptica.

    Science.gov (United States)

    Prüller, Sandra; Frömke, Cornelia; Kaspar, Heike; Klein, Günter; Kreienbrock, Lothar; Kehrenberg, Corinna

    2015-01-01

    The objective was to establish and standardise a broth microdilution susceptibility testing method for porcine Bordetella (B.) bronchiseptica. B. bronchiseptica isolates from different geographical regions and farms were genotyped by macrorestriction analysis and subsequent pulsed-field gel electrophoresis. One reference and one type strain plus two field isolates of B. bronchiseptica were chosen to analyse growth curves in four different media: cation-adjusted Mueller-Hinton broth (CAMHB) with and without 2% lysed horse blood, Brain-Heart-Infusion (BHI), and Caso broth. The growth rate of each test strain in each medium was determined by culture enumeration and the suitability of CAMHB was confirmed by comparative statistical analysis. Thereafter, reference and type strain and eight epidemiologically unrelated field isolates of B. bronchiseptica were used to test the suitability of a broth microdilution susceptibility testing method following CLSI-approved performance standards given in document VET01-A4. Susceptibility tests, using 20 antimicrobial agents, were performed in five replicates, and data were collected after 20 and 24 hours incubation and statistically analysed. Due to the low growth rate of B. bronchiseptica, an incubation time of 24 hours resulted in significantly more homogeneous minimum inhibitory concentrations after five replications compared to a 20-hour incubation. An interlaboratory comparison trial including susceptibility testing of 24 antimicrobial agents revealed a high mean level of reproducibility (97.9%) of the modified method. Hence, in a harmonization for broth microdilution susceptibility testing of B. bronchiseptica, an incubation time of 24 hours in CAMHB medium with an incubation temperature of 35°C and an inoculum concentration of approximately 5 x 10(5) cfu/ml was proposed.

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    are below 35 degrees C. Methods and QC ranges defined in this study will enable aquatic animal disease researchers to reliably compare quantitative susceptibility testing data between laboratories, and will be used to ensure both precision and inter-laboratory harmonization...... 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......-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...

  7. In Vitro Antibiotic Susceptibilities of Francisella tularensis Determined by Broth Microdilution following CLSI Methods.

    Science.gov (United States)

    Heine, Henry S; Miller, Lynda; Halasohoris, Stephanie; Purcell, Bret K

    2017-09-01

    In vitro susceptibilities for 47 antibiotics were determined in 30 genetic diverse strains of Francisella tularensis by the broth microdilution method following Clinical and Laboratory Standards Institute (CLSI) methods. The F. tularensis strains demonstrated susceptibility to aminoglycosides, fluoroquinolones, and tetracyclines. There was a distinct difference in macrolide susceptibilities between A and B type strains, as has been noted previously. The establishment and comparison of antibiotic susceptibilities of a diverse but specific set of F. tularensis strains by standardized methods and the establishment of population ranges and MIC50/90 values provide reference information for assessing new antibiotic agents and a baseline to monitor any future emergence of resistance, whether natural or intentional. Copyright © 2017 American Society for Microbiology.

  8. In vitro antibiotic susceptibilities of Yersinia pestis determined by broth microdilution following CLSI methods.

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    Heine, Henry S; Hershfield, Jeremy; Marchand, Charles; Miller, Lynda; Halasohoris, Stephanie; Purcell, Bret K; Worsham, Patricia L

    2015-04-01

    In vitro susceptibilities to 45 antibiotics were determined for 30 genetically and geographically diverse strains of Yersinia pestis by the broth microdilution method at two temperatures, 28°C and 35°C, following Clinical and Laboratory Standards Institute (CLSI) methods. The Y. pestis strains demonstrated susceptibility to aminoglycosides, quinolones, tetracyclines, β-lactams, cephalosporins, and carbapenems. Only a 1-well shift was observed for the majority of antibiotics between the two temperatures. Establishing and comparing antibiotic susceptibilities of a diverse but specific set of Y. pestis strains by standardized methods and establishing population ranges and MIC50 and MIC90 values provide reference information for assessing new antibiotic agents and also provide a baseline for use in monitoring any future emergence of resistance. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Towards a Standardized Method for Broth Microdilution Susceptibility Testing of Haemophilus parasuis.

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    Prüller, Sandra; Turni, Conny; Blackall, Patrick J; Beyerbach, Martin; Klein, Günter; Kreienbrock, Lothar; Strutzberg-Minder, Katrin; Kaspar, Heike; Meemken, Diana; Kehrenberg, Corinna

    2017-01-01

    Currently, there is no agreed method available for broth microdilution susceptibility testing of Haemophilus parasuis, one of the most important bacterial pathogens in pig production. Therefore, the aim of this study was to develop a method that could be easily performed by diagnostic laboratories and that appears suitable for a harmonized susceptibility testing. Growth determinations using one type strain and three field isolates revealed no visible growth of H. parasuis in media which have proven to be suitable for susceptibility testing of fastidious organisms. Therefore, a new medium, cation-adjusted Mueller-Hinton broth (CAMHB) plus NADH and sterile filtered heat-inactivated chicken serum, was developed. The reproducibility of MICs obtained in this medium was evaluated and statistically analyzed, considering a model with two different variables (precondition of five identical MICs and MIC mode accepting a deviation of ±1 dilution step, respectively). No significant differences for both variables were seen between two time points investigated and between results obtained with the recently proposed test medium broth (TMB). Nearly all MICs of quality control strains were in the acceptable range. Subsequently, 47 H. parasuis isolates representing 13 serovars were tested with the newly developed medium and TMB. Statistical analysis of all isolates and 15 antimicrobial agents and antimicrobial combinations showed no significant difference between MICs obtained in supplemented CAMHB and TMB. Because of a simplified implementation in routine diagnostic and a lower chance of interference between medium components and antimicrobial agents, supplemented CAMHB is recommended with an incubation time of 24 h. Copyright © 2016 American Society for Microbiology.

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

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

    2012-04-01

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

  11. Multisite Reproducibility of the Broth Microdilution Method for Susceptibility Testing of Nocardia Species

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

    2012-01-01

    Antimicrobial susceptibility testing (AST) of clinical isolates of Nocardia is recommended to detect resistance to commonly used antimicrobial agents; such testing is complicated by difficulties in inoculum preparation and test interpretation. In this study, six laboratories performed repetitive broth microdilution testing on single strains of Nocardia brasiliensis, Nocardia cyriacigeorgica, Nocardia farcinica, Nocardia nova, and Nocardia wallacei. For each isolate, a total of 30 microdilution panels from three different lots were tested at most sites. The goal of the study was to determine the inter- and intralaboratory reproducibility of susceptibility testing of this group of isolates. Acceptable agreement (>90% agreement at ±1 dilution of the MIC mode) was found for amikacin, ciprofloxacin, clarithromycin, and moxifloxacin. After eliminating MIC values from single laboratories whose results showed the greatest deviation from those of the remaining laboratories, acceptable agreement was also found for amoxicillin-clavulanic acid, linezolid, minocycline, and tobramycin. Results showed unsatisfactory reproducibility of broth microdilution testing of ceftriaxone with N. cyriacigeorgica and N. wallacei, tigecycline with N. brasiliensis and N. cyriacigeorgica, and sulfonamides with N. farcinica and N. wallacei. N. nova ATCC BAA-2227 is proposed as a quality control organism for AST of Nocardia sp., and the use of a disk diffusion test for sulfisoxazole is proposed as a check of the adequacy of the inoculum and to confirm sulfonamide MIC results. PMID:22219309

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

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    Mahmoudi Rad M

    2010-02-01

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

  13. Variability of β-lactam susceptibility testing for Streptococcus pneumoniae using 4 commercial test methods and broth microdilution.

    Science.gov (United States)

    Charles, Marthe K; Berenger, Byron M; Turnbull, LeeAnn; Rennie, Robert; Fuller, Jeff

    2016-03-01

    Limited data are available that verify the performance of commercial susceptibility methods for Streptococcus pneumoniae following the 2008 Clinical and Laboratory Standards Institute revision of the β-lactam breakpoints. We compared the performance of Etest, M.I.C. Evaluator (M.I.C.E), Vitek, and Sensititre systems to broth microdilution for S. pneumoniae susceptibility testing of penicillin, ceftriaxone, meropenem, and amoxicillin. Essential agreement was ≥90% for the majority of the β-lactams and methods tested, particularly for penicillin and ceftriaxone. Categorical agreements (CAs) for penicillin using meningeal and nonmeningeal breakpoints were ≥90%; CAs using penicillin oral breakpoints were 84-89%. Ceftriaxone CAs using nonmeningeal and meningeal breakpoints were 68-88% for Etest, M.I.C.E., and Vitek2 with 6-12% very major errors (VMEs) using meningeal breakpoints. Sensititre CAs for ceftriaxone, amoxicillin, and meropenem were ≥90% with no VMEs. In the context of the current guidelines, there exists considerable method-dependent variability in the susceptibility of S. pneumoniae to β-lactams. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Optimal Concentration of Organic Solvents to be Used in the Broth Microdilution Method to Determine the Antimicrobial Activity of Natural Products Against Paenibacillus Larvae

    OpenAIRE

    Cugnata Noelia Melina; Guaspari Elisa; Pellegrini Maria Celeste; Fuselli Sandra Rosa; Alonso-Salces Rosa Maria

    2017-01-01

    American Foulbrood (AFB) is a bacterial disease, caused by Paenibacillus larvae, that affects honeybees (Apis mellifera). Alternative strategies to control AFB are based on the treatment of the beehives with antimicrobial natural substances such as extracts, essential oils and/or pure compounds from plants, honey by-products, bacteria and moulds. The broth microdilution method is currently one of the most widely used methods to determine the minimum inhibitory concentration (MIC) of a substan...

  15. Determination of minimum inhibitory concentrations of itraconazole, terbinafine and ketoconazole against dermatophyte species by broth microdilution method

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    V K Bhatia

    2015-01-01

    Full Text Available Purpose: Various antifungal agents both topical and systemic have been introduced into clinical practice for effectively treating dermatophytic conditions. Dermatophytosis is the infection of keratinised tissues caused by fungal species of genera Trichophyton, Epidermophyton and Microsporum, commonly known as dermatophytes affecting 20–25% of the world's population. The present study aims at determining the susceptibility patterns of dermatophyte species recovered from superficial mycoses of human patients in Himachal Pradesh to antifungal agents; itraconazole, terbinafine and ketoconazole. The study also aims at determining the minimum inhibitory concentrations (MICs of these agents following the recommended protocol of Clinical and Laboratory Standards Institute (CLSI (M38-A2. Methodology: A total of 53 isolates of dermatophytes (T. mentagrophyte-34 in no., T. rubrum-18 and M. gypseum-1 recovered from the superficial mycoses were examined. Broth microdilution method M38-A2 approved protocol of CLSI (2008 for filamentous fungi was followed for determining the susceptibility of dermatophyte species. Results: T. mentagrophyte isolates were found more susceptible to both itraconazole and ketoconazole as compared to terbinafine (MIC50: 0.125 µg/ml for itraconazole, 0.0625 µg/ml for ketoconazole and 0.5 µg/ml for terbinafine. Three isolates of T. mentagrophytes (VBS-5, VBSo-3 and VBSo-73 and one isolate of T. rubrum (VBPo-9 had higher MIC values of itraconazole (1 µg/ml. Similarly, the higher MIC values of ketoconazole were observed in case of only three isolates of T. mentagrophyte (VBSo-30 = 2 µg/ml; VBSo-44, VBM-2 = 1 µg/ml. The comparative analysis of the three antifungal drugs based on t-test revealed that 'itraconazole and terbinafine' and 'terbinafine and ketoconazole' were found independent based on the P < 0.005 in case of T. mentagrophyte isolates. In case of T. rubrum, the similarity existed between MIC values of 'itraconazole and

  16. Optimal Concentration of Organic Solvents to be Used in the Broth Microdilution Method to Determine the Antimicrobial Activity of Natural Products Against Paenibacillus Larvae

    Directory of Open Access Journals (Sweden)

    Cugnata Noelia Melina

    2017-06-01

    Full Text Available American Foulbrood (AFB is a bacterial disease, caused by Paenibacillus larvae, that affects honeybees (Apis mellifera. Alternative strategies to control AFB are based on the treatment of the beehives with antimicrobial natural substances such as extracts, essential oils and/or pure compounds from plants, honey by-products, bacteria and moulds. The broth microdilution method is currently one of the most widely used methods to determine the minimum inhibitory concentration (MIC of a substance. In this regard, the fact that most natural products, due to their lipophilic nature, must be dissolved in organic solvents or their aqueous mixtures is an issue of major concern because the organic solvent becomes part of the dilution in the incubation medium, and therefore, can interfere with bacterial viability depending on its nature and concentration. A systematic study was carried out to determine by the broth microdilution method the MIC and the maximum non inhibitory concentration (MNIC against P. larvae of the most common organic solvents used to extract or dissolve natural products, i.e. ethanol, methanol, acetonitrile, n-butanol, dimethylsulfoxide, and acidified hydromethanolic solutions. From the MIC and MNIC for each organic solvent, recommended maximum concentrations in contact with P. larvae were established: DMSO 5% (v/v, acetonitrile 7.5% (v/v, ethanol 7.5% (v/v, methanol 12% (v/v, n-butanol 1% (v/v, and methanol-water-acetic acid (1.25:98.71:0.04, v/v/v.

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

    Science.gov (United States)

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

    2012-11-01

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

  18. Progress in Antifungal Susceptibility Testing of Candida spp. by Use of Clinical and Laboratory Standards Institute Broth Microdilution Methods, 2010 to 2012

    Science.gov (United States)

    Pfaller, M. A.

    2012-01-01

    Antifungal susceptibility testing of Candida has been standardized and refined and now may play a useful role in managing Candida infections. Important new developments include validation of 24-h reading times for all antifungal agents and the establishment of species-specific epidemiological cutoff values (ECVs) for the systemically active antifungal agents and both common and uncommon species of Candida. The clinical breakpoints (CBPs) for fluconazole, voriconazole, and the echinocandins have been revised to provide species-specific interpretive criteria for the six most common species. The revised CBPs not only are predictive of clinical outcome but also provide a more sensitive means of identifying those strains with acquired or mutational resistance mechanisms. This brief review serves as an update on the new developments in the antifungal susceptibility testing of Candida spp. using Clinical and Laboratory Standards Institute (CLSI) broth microdilution (BMD) methods. PMID:22740712

  19. Comparison of European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Etest methods with the CLSI broth microdilution method for echinocandin susceptibility testing of Candida species.

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    Pfaller, M A; Castanheira, M; Diekema, D J; Messer, S A; Moet, G J; Jones, R N

    2010-05-01

    The antifungal broth microdilution (BMD) method of the European Committee on Antibiotic Susceptibility Testing (EUCAST) and the Etest agar diffusion method were compared with the Clinical and Laboratory Standards Institute (CLSI) BMD method M27-A3 for anidulafungin, caspofungin, and micafungin susceptibility testing of 133 clinical isolates of Candida species. The isolates were characterized for the presence or absence of fks1 and/or fks2 gene mutations and included 34 isolates of C. glabrata (4 mutant strains), 32 of C. albicans (1 mutant strain), 25 of C. parapsilosis, 19 of C. guilliermondii, 12 of C. tropicalis (2 mutant strains), and 11 of C. krusei. Excellent essential agreement (EA; within 2 dilutions) between the CLSI and EUCAST and CLSI and Etest MIC results was observed. The overall EA between the EUCAST and CLSI results ranged from 89.5% (caspofungin) to 99.2% (micafungin), whereas the EA between the Etest and CLSI results ranged from 90.2% (caspofungin) to 93.2% (anidulafungin). The categorical agreement (CA) between methods for each antifungal agent was assessed using previously determined epidemiological cutoff values (ECVs). Excellent CA (>90%) was observed for all comparisons between the EUCAST and CLSI results with the exceptions of C. glabrata and caspofungin (85.3%) and C. krusei and caspofungin (54.5%). The CA between the Etest and CLSI results was also excellent for all comparisons, with the exception of C. krusei and caspofungin (81.8%). All three methods were able to differentiate wild-type (WT) strains from those with fks mutations. With anidulafungin as the test reagent, the CLSI method identified 5 of 7 mutant strains, whereas the EUCAST method and the Etest identified 6 of 7 mutant strains. With either caspofungin or micafungin as the test reagent, the CLSI method identified all 7 mutant strains and the EUCAST method identified 6 of 7 mutant strains. The Etest identified all 7 mutant strains using caspofungin as the reagent. All three

  20. Comparison of European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Etest Methods with the CLSI Broth Microdilution Method for Echinocandin Susceptibility Testing of Candida Species▿

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    Pfaller, M. A.; Castanheira, M.; Diekema, D. J.; Messer, S. A.; Moet, G. J.; Jones, R. N.

    2010-01-01

    The antifungal broth microdilution (BMD) method of the European Committee on Antibiotic Susceptibility Testing (EUCAST) and the Etest agar diffusion method were compared with the Clinical and Laboratory Standards Institute (CLSI) BMD method M27-A3 for anidulafungin, caspofungin, and micafungin susceptibility testing of 133 clinical isolates of Candida species. The isolates were characterized for the presence or absence of fks1 and/or fks2 gene mutations and included 34 isolates of C. glabrata (4 mutant strains), 32 of C. albicans (1 mutant strain), 25 of C. parapsilosis, 19 of C. guilliermondii, 12 of C. tropicalis (2 mutant strains), and 11 of C. krusei. Excellent essential agreement (EA; within 2 dilutions) between the CLSI and EUCAST and CLSI and Etest MIC results was observed. The overall EA between the EUCAST and CLSI results ranged from 89.5% (caspofungin) to 99.2% (micafungin), whereas the EA between the Etest and CLSI results ranged from 90.2% (caspofungin) to 93.2% (anidulafungin). The categorical agreement (CA) between methods for each antifungal agent was assessed using previously determined epidemiological cutoff values (ECVs). Excellent CA (>90%) was observed for all comparisons between the EUCAST and CLSI results with the exceptions of C. glabrata and caspofungin (85.3%) and C. krusei and caspofungin (54.5%). The CA between the Etest and CLSI results was also excellent for all comparisons, with the exception of C. krusei and caspofungin (81.8%). All three methods were able to differentiate wild-type (WT) strains from those with fks mutations. With anidulafungin as the test reagent, the CLSI method identified 5 of 7 mutant strains, whereas the EUCAST method and the Etest identified 6 of 7 mutant strains. With either caspofungin or micafungin as the test reagent, the CLSI method identified all 7 mutant strains and the EUCAST method identified 6 of 7 mutant strains. The Etest identified all 7 mutant strains using caspofungin as the reagent. All three

  1. In vitro activity of a new oral glucan synthase inhibitor (MK-3118) tested against Aspergillus spp. by CLSI and EUCAST broth microdilution methods.

    Science.gov (United States)

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

    2013-02-01

    MK-3118, a glucan synthase inhibitor derived from enfumafungin, and comparator agents were tested against 71 Aspergillus spp., including itraconazole-resistant strains (MIC, ≥ 4 μg/ml), using CLSI and EUCAST reference broth microdilution methods. The CLSI 90% minimum effective concentration (MEC(90))/MIC(90) values (μg/ml) for MK-3118, amphotericin B, and caspofungin, respectively, were as follows: 0.12, 2, and 0.03 for Aspergillus flavus species complex (SC); 0.25, 2, and 0.06 for Aspergillus fumigatus SC; 0.12, 2, and 0.06 for Aspergillus terreus SC; and 0.06, 1, and 0.03 for Aspergillus niger SC. Essential agreement between the values found by CLSI and EUCAST (± 2 log(2) dilution steps) was 94.3%. MK-3118 was determined to be a potent agent regardless of the in vitro method applied, with excellent activity against contemporary wild-type and itraconazole-resistant strains of Aspergillus spp.

  2. Activities of E1210 and Comparator Agents Tested by CLSI and EUCAST Broth Microdilution Methods against Fusarium and Scedosporium Species Identified Using Molecular Methods

    Science.gov (United States)

    Duncanson, Frederick P.; Diekema, Daniel J.; Guarro, Josep; Jones, Ronald N.; Pfaller, Michael A.

    2012-01-01

    Fusarium (n = 67) and Scedosporium (n = 63) clinical isolates were tested by two reference broth microdilution (BMD) methods against a novel broad-spectrum (active against both yeasts and molds) antifungal, E1210, and comparator agents. E1210 inhibits the inositol acylation step in glycophosphatidylinositol (GPI) biosynthesis, resulting in defects in fungal cell wall biosynthesis. Five species complex organisms/species of Fusarium (4 isolates unspeciated) and 28 Scedosporium apiospermum, 7 Scedosporium aurantiacum, and 28 Scedosporium prolificans species were identified by molecular techniques. Comparator antifungal agents included anidulafungin, caspofungin, itraconazole, posaconazole, voriconazole, and amphotericin B. E1210 was highly active against all of the tested isolates, with minimum effective concentration (MEC)/MIC90 values (μg/ml) for E1210, anidulafungin, caspofungin, itraconazole, posaconazole, voriconazole, and amphotericin B, respectively, for Fusarium of 0.12, >16, >16, >8, >8, 8, and 4 μg/ml. E1210 was very potent against the Scedosporium spp. tested. The E1210 MEC90 was 0.12 μg/ml for S. apiospermum, but 1 to >8 μg/ml for other tested agents. Against S. aurantiacum, the MEC50 for E1210 was 0.06 μg/ml versus 0.5 to >8 μg/ml for the comparators. Against S. prolificans, the MEC90 for E1210 was only 0.12 μg/ml, compared to >4 μg/ml for amphotericin B and >8 μg/ml for itraconazole, posaconazole, and voriconazole. Both CLSI and EUCAST methods were highly concordant for E1210 and all comparator agents. The essential agreement (EA; ±2 doubling dilutions) was >93% for all comparisons, with the exception of posaconazole and F. oxysporum species complex (SC) (60%), posaconazole and S. aurantiacum (85.7%), and voriconazole and S. aurantiacum (85.7%). In conclusion, E1210 exhibited very potent and broad-spectrum antifungal activity against azole- and amphotericin B-resistant strains of Fusarium spp. and Scedosporium spp. Furthermore, in vitro

  3. Antifungal susceptibility of 205 Candida spp. isolated primarily during invasive Candidiasis and comparison of the Vitek 2 system with the CLSI broth microdilution and Etest methods.

    Science.gov (United States)

    Bourgeois, N; Dehandschoewercker, L; Bertout, S; Bousquet, P-J; Rispail, P; Lachaud, L

    2010-01-01

    Infections due to Candida spp. are frequent, particularly in immunocompromised and intensive care unit patients. Antifungal susceptibility tests are now required to optimize antifungal treatment given the emergence of acquired antifungal resistance in some Candida species. An antifungal susceptibility automated method, the Vitek 2 system (VK2), was evaluated. VK2 was compared to the CLSI broth microdilution reference method and the Etest procedure. For this purpose, 205 clinical isolates of Candida spp., including 11 different species, were tested for fluconazole, voriconazole, and amphotericin B susceptibility. For azoles, essential agreement ranged from 25% to 100%, depending on the method used and the Candida species tested. Categorical agreements for all of the species averaged 92.2% and ranged from 14.3 to 100%, depending on the 24-h or 48-h MIC reading by the Etest and CLSI methods and on the Candida species. Results obtained for Candida albicans showed excellent categorical and essential agreements with the two comparative methods. For Candida glabrata, the essential agreement was high with the CLSI method but low with the Etest method, and several very major errors in interpretation were observed between VK2 and the Etest method for both azoles. Low MICs of fluconazole were obtained for all of the Candida krusei isolates, but the VK2 expert software corrected all of the results obtained to resistant. Amphotericin B results showed MICs of CLSI), and 202 (Etest) isolates. The AST-YS01 Vitek 2 card system (bioMérieux) is a reliable and practical standardized automated antifungal susceptibility test. Nevertheless, more assays are needed to better evaluate C. glabrata fluconazole sensitivity.

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

    Science.gov (United States)

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

    2014-06-01

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

  5. Reproducible measurement of vancomycin MICs within the susceptible range in Staphylococcus aureus by a broth microdilution method with a "quasi-continuum" gradient of antibiotic concentrations.

    Science.gov (United States)

    Falcón, R; Mateo, E M; Talaya, A; Giménez, E; Vinuesa, V; Clari, M Á; Navarro, D

    2017-12-01

    The availability of reproducible broth microdilution (BMD) methods including inter log 2 antibiotic dilutions for measuring Staphylococcus aureus (SA) vancomycin minimum inhibitory concentrations (MICs) within the susceptible range is needed to elucidate the impact of vancomycin MICs on clinical outcomes of invasive SA infections. Here, we report on the development of a very precise BMD method that incorporates the following incremental antibiotic concentrations: 0.50, 0.62, 0.75, 0.87, 1.0, 1.25, 1.40, 1.50, 1.60, 1.75, and 2.0 μg/mL. The intra- and inter-assay coefficients of variation of this method were around 20%. The mean of the differences in MIC values for all isolates obtained across two independent runs performed at one center was 0.04 μg/mL [95% confidence interval (CI), 0.011-0.07 μg/mL] and that for ten isolates measured at two different centers was 0.04 μg/mL (95% CI, 0-13 μg/mL). Vancomycin MIC values differed by less than 0.1 μg/mL between runs for most isolates. Storage of isolates at -20 °C for up to 3 months had no impact on the vancomycin MIC values. The mean vancomycin MIC values obtained by the Etest using a standard inoculum (0.5 McFarland) were significantly higher (p ≤ 0.001) than those measured by BMD and the MIC values measured by the two methods correlated poorly (Rho, 0.319; p = 0.148). Nevertheless, the mean MIC values measured by the Etest using lower inocula (10 7 or 10 6  CFU/mL) and those measured by BMD were comparable and correlated significantly (p = 0.004 for 10 7  CFU/mL and p = 0.029 for 10 6  CFU/mL).

  6. Wild-type MIC distributions and epidemiological cutoff values for amphotericin B and Aspergillus spp. for the CLSI broth microdilution method (M38-A2 document).

    Science.gov (United States)

    Espinel-Ingroff, A; Cuenca-Estrella, M; Fothergill, A; Fuller, J; Ghannoum, M; Johnson, E; Pelaez, T; Pfaller, M A; Turnidge, J

    2011-11-01

    Although clinical breakpoints have not been established for mold testing, epidemiological cutoff values (ECVs) are available for Aspergillus spp. versus the triazoles and caspofungin. Wild-type (WT) MIC distributions (organisms in a species-drug combination with no acquired resistance mechanisms) were defined in order to establish ECVs for six Aspergillus spp. and amphotericin B. Two sets (CLSI/EUCAST broth microdilution) of available MICs were evaluated: those for A. fumigatus (3,988/833), A. flavus (793/194), A. nidulans (184/69), A. niger (673/140), A. terreus (545/266), and A. versicolor (135/22). Three sets of data were analyzed: (i) CLSI data gathered in eight independent laboratories in Canada, Europe, and the United States; (ii) EUCAST data from a single laboratory; and (iii) the combined CLSI and EUCAST data. ECVs, expressed in μg/ml, that captured 95%, 97.5%, and 99% of the modeled wild-type population (CLSI and combined data) were as follows: for A. fumigatus, 2, 2, and 4; for A. flavus, 2, 4, and 4; for A. nidulans, 4, 4, and 4; for A. niger, 2, 2, and 2; for A. terreus, 4, 4, and 8; and for A. versicolor, 2, 2, and 2. Similar to the case for the triazoles and caspofungin, amphotericin B ECVs may aid in the detection of strains with acquired mechanisms of resistance to this agent.

  7. Wild-Type MIC Distributions and Epidemiological Cutoff Values for Amphotericin B and Aspergillus spp. for the CLSI Broth Microdilution Method (M38-A2 Document)▿

    Science.gov (United States)

    Espinel-Ingroff, A.; Cuenca-Estrella, M.; Fothergill, A.; Fuller, J.; Ghannoum, M.; Johnson, E.; Pelaez, T.; Pfaller, M. A.; Turnidge, J.

    2011-01-01

    Although clinical breakpoints have not been established for mold testing, epidemiological cutoff values (ECVs) are available for Aspergillus spp. versus the triazoles and caspofungin. Wild-type (WT) MIC distributions (organisms in a species-drug combination with no acquired resistance mechanisms) were defined in order to establish ECVs for six Aspergillus spp. and amphotericin B. Two sets (CLSI/EUCAST broth microdilution) of available MICs were evaluated: those for A. fumigatus (3,988/833), A. flavus (793/194), A. nidulans (184/69), A. niger (673/140), A. terreus (545/266), and A. versicolor (135/22). Three sets of data were analyzed: (i) CLSI data gathered in eight independent laboratories in Canada, Europe, and the United States; (ii) EUCAST data from a single laboratory; and (iii) the combined CLSI and EUCAST data. ECVs, expressed in μg/ml, that captured 95%, 97.5%, and 99% of the modeled wild-type population (CLSI and combined data) were as follows: for A. fumigatus, 2, 2, and 4; for A. flavus, 2, 4, and 4; for A. nidulans, 4, 4, and 4; for A. niger, 2, 2, and 2; for A. terreus, 4, 4, and 8; and for A. versicolor, 2, 2, and 2. Similar to the case for the triazoles and caspofungin, amphotericin B ECVs may aid in the detection of strains with acquired mechanisms of resistance to this agent. PMID:21876047

  8. Multicenter study of anidulafungin and micafungin MIC distributions and epidemiological cutoff values for eight Candida species and the CLSI M27-A3 broth microdilution method.

    Science.gov (United States)

    Pfaller, M A; Espinel-Ingroff, A; Bustamante, B; Canton, E; Diekema, D J; Fothergill, A; Fuller, J; Gonzalez, G M; Guarro, J; Lass-Flörl, C; Lockhart, S R; Martin-Mazuelos, E; Meis, J F; Ostrosky-Zeichner, L; Pelaez, T; St-Germain, G; Turnidge, J

    2014-01-01

    Since epidemiological cutoff values (ECVs) using CLSI MICs from multiple laboratories are not available for Candida spp. and the echinocandins, we established ECVs for anidulafungin and micafungin on the basis of wild-type (WT) MIC distributions (for organisms in a species-drug combination with no detectable acquired resistance mechanisms) for 8,210 Candida albicans, 3,102 C. glabrata, 3,976 C. parapsilosis, 2,042 C. tropicalis, 617 C. krusei, 258 C. lusitaniae, 234 C. guilliermondii, and 131 C. dubliniensis isolates. CLSI broth microdilution MIC data gathered from 15 different laboratories in Canada, Europe, Mexico, Peru, and the United States were aggregated to statistically define ECVs. ECVs encompassing 97.5% of the statistically modeled population for anidulafungin and micafungin were, respectively, 0.12 and 0.03 μg/ml for C. albicans, 0.12 and 0.03 μg/ml for C. glabrata, 8 and 4 μg/ml for C. parapsilosis, 0.12 and 0.06 μg/ml for C. tropicalis, 0.25 and 0.25 μg/ml for C. krusei, 1 and 0.5 μg/ml for C. lusitaniae, 8 and 2 μg/ml for C. guilliermondii, and 0.12 and 0.12 μg/ml for C. dubliniensis. Previously reported single and multicenter ECVs defined in the present study were quite similar or within 1 2-fold dilution of each other. For a collection of 230 WT isolates (no fks mutations) and 51 isolates with fks mutations, the species-specific ECVs for anidulafungin and micafungin correctly classified 47 (92.2%) and 51 (100%) of the fks mutants, respectively, as non-WT strains. These ECVs may aid in detecting non-WT isolates with reduced susceptibility to anidulafungin and micafungin due to fks mutations.

  9. Quality control ranges for testing broth microdilution susceptibility of Flavobacterium columnare and F. psychrophilum to nine antimicrobials

    DEFF Research Database (Denmark)

    Gieseker, Charles M.; Mayer, Tamara D.; Crosby, Tina C.

    2012-01-01

    A multi-laboratory broth microdilution method trial was performed to standardize the specialized test conditions required for the fish pathogens Flavobacterium columnare and F. psychrophilum. Nine laboratories tested the quality control (QC) strains Escherichia coli ATCC 25922 and Aeromonas salmo...

  10. Comparison of the Broth Microdilution (BMD) Method of the European Committee on Antimicrobial Susceptibility Testing with the 24-Hour CLSI BMD Method for Testing Susceptibility of Candida Species to Fluconazole, Posaconazole, and Voriconazole by Use of Epidemiological Cutoff Values▿

    Science.gov (United States)

    Pfaller, M. A.; Espinel-Ingroff, A.; Boyken, L.; Hollis, R. J.; Kroeger, J.; Messer, S. A.; Tendolkar, S.; Diekema, D. J.

    2011-01-01

    The antifungal broth microdilution (BMD) method of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) was compared with CLSI BMD method M27-A3 for fluconazole, posaconazole, and voriconazole susceptibility testing of 1,056 isolates of Candida. The isolates were obtained in 2009 from more than 60 centers worldwide and included 560 isolates of C. albicans, 175 of C. glabrata, 162 of C. parapsilosis, 124 of C. tropicalis, and 35 of C. krusei. The overall essential agreement (EA) between EUCAST and CLSI results ranged from 96.9% (voriconazole) to 98.6% (fluconazole). The categorical agreement (CA) between methods and species of Candida was assessed using previously determined epidemiological cutoff values (ECVs). The ECVs (expressed as μg/ml) for fluconazole, posaconazole, and voriconazole, respectively, were as follows: 0.12, 0.06, and 0.03 for C. albicans; 32, 2, and 0.5 for C. glabrata; 2, 0.25, and 0.12 for C. parapsilosis; 2, 0.12, and 0.06 for C. tropicalis; 64, 0.5, and 0.5 for C. krusei. Excellent CA was observed for all comparisons between the EUCAST and CLSI results for fluconazole, posaconazole, and voriconazole, respectively, for each species: 98.9%, 93.6%, and 98.6% for C. albicans; 96.0%, 98.9%, and 93.7% for C. glabrata; 90.8%, 98.1%, and 98.1% for C. parapsilosis; 99.2%, 99.2%, and 96.8% for C. tropicalis; 97.1%, 97.1%, and 97.1% for C. krusei. We demonstrate high levels of EA and CA between the CLSI and EUCAST BMD methods for testing of triazoles against Candida when the MICs were determined after 24 h and ECVs were used to differentiate wild-type (WT) from non-WT strains. These results provide additional data in favor of the harmonization of these two methods. PMID:21227994

  11. Comparison of the broth microdilution (BMD) method of the European Committee on Antimicrobial Susceptibility Testing with the 24-hour CLSI BMD method for testing susceptibility of Candida species to fluconazole, posaconazole, and voriconazole by use of epidemiological cutoff values.

    Science.gov (United States)

    Pfaller, M A; Espinel-Ingroff, A; Boyken, L; Hollis, R J; Kroeger, J; Messer, S A; Tendolkar, S; Diekema, D J

    2011-03-01

    The antifungal broth microdilution (BMD) method of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) was compared with CLSI BMD method M27-A3 for fluconazole, posaconazole, and voriconazole susceptibility testing of 1,056 isolates of Candida. The isolates were obtained in 2009 from more than 60 centers worldwide and included 560 isolates of C. albicans, 175 of C. glabrata, 162 of C. parapsilosis, 124 of C. tropicalis, and 35 of C. krusei. The overall essential agreement (EA) between EUCAST and CLSI results ranged from 96.9% (voriconazole) to 98.6% (fluconazole). The categorical agreement (CA) between methods and species of Candida was assessed using previously determined epidemiological cutoff values (ECVs). The ECVs (expressed as μg/ml) for fluconazole, posaconazole, and voriconazole, respectively, were as follows: 0.12, 0.06, and 0.03 for C. albicans; 32, 2, and 0.5 for C. glabrata; 2, 0.25, and 0.12 for C. parapsilosis; 2, 0.12, and 0.06 for C. tropicalis; 64, 0.5, and 0.5 for C. krusei. Excellent CA was observed for all comparisons between the EUCAST and CLSI results for fluconazole, posaconazole, and voriconazole, respectively, for each species: 98.9%, 93.6%, and 98.6% for C. albicans; 96.0%, 98.9%, and 93.7% for C. glabrata; 90.8%, 98.1%, and 98.1% for C. parapsilosis; 99.2%, 99.2%, and 96.8% for C. tropicalis; 97.1%, 97.1%, and 97.1% for C. krusei. We demonstrate high levels of EA and CA between the CLSI and EUCAST BMD methods for testing of triazoles against Candida when the MICs were determined after 24 h and ECVs were used to differentiate wild-type (WT) from non-WT strains. These results provide additional data in favor of the harmonization of these two methods.

  12. Underestimation of Vancomycin and Teicoplanin MICs by Broth Microdilution Leads to Underdetection of Glycopeptide-Intermediate Isolates of Staphylococcus aureus▿ †

    Science.gov (United States)

    Vaudaux, Pierre; Huggler, Elzbieta; Bernard, Louis; Ferry, Tristan; Renzoni, Adriana; Lew, Daniel P.

    2010-01-01

    Broth microdilution was compared with tube macrodilution and a simplified population analysis agar method for evaluating vancomycin and teicoplanin MICs and detecting glycopeptide-intermediate isolates of Staphylococcus aureus. Modal vancomycin and teicoplanin MICs recorded by tube macrodilution and the agar plate assay, which both used inocula of 106 CFU, were significantly higher (2 μg/ml) against a panel of borderline glycopeptide-susceptible and glycopeptide-intermediate methicillin-resistant S. aureus (MRSA) bloodstream isolates compared to broth microdilution (1 μg/ml). Vancomycin and teicoplanin MIC distributions by tube macrodilution and agar testing were also markedly different from those evaluated by broth microdilution. The 20-fold-lower inoculum size used for broth microdilution compared to macrodilution and agar MIC assays explained in part, but not entirely, the systematic trend toward lower vancomycin and teicoplanin MICs by microdilution compared to other methods. Broth microdilution assay led to underdetection of the vancomycin-intermediate S. aureus (VISA) phenotype, yielding only three VISA isolates, for which vancomycin MICs were 4 μg/ml compared to 8 and 19 VISA isolates detected by macrodilution and agar testing, respectively. While macrodilution and agar testing detected 7 and 22 isolates with elevated teicoplanin MICs (8 μg/ml), respectively, broth microdilution failed to detect such isolates. Detection rates of isolates with elevated vancomycin and teicoplanin MICs by macrodilution and agar testing assays were higher at 48 h than at 24 h. In conclusion, the sensitivity of broth microdilution MIC testing is questionable for reliable detection and epidemiological surveys of glycopeptide-intermediate resistance in S. aureus isolates. PMID:20547791

  13. Comparison of Assessment of Oxygen Consumption, Etest, and CLSI M38-A2 Broth Microdilution Methods for Evaluation of the Susceptibility of Aspergillus fumigatus to Posaconazole▿

    OpenAIRE

    Araujo, Ricardo; Espinel-Ingroff, Ana

    2009-01-01

    Posaconazole MICs for 50 Aspergillus fumigatus isolates with distinct genotypes were determined by three methods. MICs were ≥0.5 μg/ml for 5, 11, and 15 strains by the CLSI reference M38-A2, Etest (48-h), and oxygen consumption methods, respectively. The levels of categorical agreement between the results obtained by the CLSI method and those obtained by the oxygen consumption and Etest methods were 80 and 84%, respectively.

  14. Comparison of the EUCAST and CLSI Broth Microdilution Methods for Testing Isavuconazole, Posaconazole, and Amphotericin B against Molecularly Identified Mucorales Species.

    Science.gov (United States)

    Chowdhary, Anuradha; Singh, Pradeep Kumar; Kathuria, Shallu; Hagen, Ferry; Meis, Jacques F

    2015-12-01

    We compared EUCAST and CLSI antifungal susceptibility testing (AFST) methods for triazoles and amphotericin B against 124 clinical Mucorales isolates. The EUCAST method yielded MIC values 1- to 3-fold dilutions higher than those of the CLSI method for amphotericin B. The essential agreements between the two methods for triazoles were high, i.e., 99.1% (voriconazole), 98.3% (isavuconazole), and 87% (posaconazole), whereas it was significantly lower for amphotericin B (66.1%). Strategies for harmonization of the two methods for Mucorales AFST are warranted. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Investigation of susceptibility of Staphylococcus species to some antibacterial drugs by disk diffusion and broth microdilution

    Directory of Open Access Journals (Sweden)

    Ašanin Jelena

    2012-01-01

    Full Text Available The objective of this work was to identify isolated Staphylococcus species and to investigate their sensitivity to some antibacterial drugs. The material used for these investigations were Staphylococcus isolates originating from milk samples. A total of 25 strains of Staphylococcus isolates were examined, including 24 from milk samples from cows with mastitis, and one strain was isolated from a milk sample from a cow following treatment for mastitis. For primary identification, catalase and oxidase tests were used, as well as the free coagulase test. Following the preliminary tests, the isolated strains were identified using commercial systems ID32 STAPH (bioMérieux, France and the BBL Crystal Gram-Positive ID Kit (Becton Dickinson, USA according to the enclosed instructions. The Staphylococcus isolates were examined for sensitivity to the following: oxacillin, penicillin, cefoxitin, gentamicin, erythromycin, chloramphenicol, tetracycline, ciprofloxacin, sulfametoxazol/trimetoprim, and vacomycin using the disk diffusion method and the broth microdilution method as recommended by the Clinical and Laboratory Strandards Institute - CLSI(2003, and the results were interpreted according to CLSI recommendations from 2008 and 2010. Antibiogram disks manufactured by Becton Dickinson (USA were used, and the broth microdilution method was applied using pure antibiotic substances from different manufacturers: erythromycin, chloramphenicol, cefoxitin, gentamicin, oxacillin, tetracycline (Sigma Aldrich, USA, sulfametoxazol (Fluka, USA, penicillin (Calbiochem, Germany, vancomycin (Abbott laboratories, USA, ciprofloxacin and trimetoprim (Zdravlje A.D., Serbia. All 25 strains were catalase positive and oxidase negative. Of the 25 strains, 19 were coagulase positive and 6 were coagulase negative.With the implementation of the disk diffusion method on 19 strains of S. aureus, 17 were established to be resistant to penicillin (89.5%, and 2 strains to gentamicin

  16. International and multicenter comparison of EUCAST and CLSI M27-A2 broth microdilution methods for testing susceptibilities of Candida spp. to fluconazole, itraconazole, posaconazole, and voriconazole.

    NARCIS (Netherlands)

    Espinel-Ingroff, A.; Barchiesi, F.; Cuenca-Estrella, M.; Pfaller, M.A.; Rinaldi, M.; Rodriguez-Tudela, J.L.; Verweij, P.E.

    2005-01-01

    The aim of this study was to compare MICs of fluconazole, itraconazole, posaconazole, and voriconazole obtained by the European Committee on Antibiotic Susceptibility Testing (EUCAST) and CLSI (formerly NCCLS) methods in each of six centers for 15 Candida albicans (5 fluconazole-resistant and 4

  17. Wild-type MIC distributions, epidemiological cutoff values and species-specific clinical breakpoints for fluconazole and Candida: time for harmonization of CLSI and EUCAST broth microdilution methods.

    Science.gov (United States)

    Pfaller, M A; Andes, D; Diekema, D J; Espinel-Ingroff, A; Sheehan, D

    2010-12-01

    Both the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) have MIC clinical breakpoints (CBPs) for fluconazole (FLU) and Candida. EUCAST CBPs are species-specific, and apply only to C. albicans, C. tropicalis and C. parapsilosis, while CLSI CBPs apply to all species. We reassessed the CLSI CBPs for FLU and Candida in light of recent data. We examined (1) molecular mechanisms of resistance and cross-resistance profiles, (2) wild-type (WT) MICs and epidemiological cutoff values (ECVs) for FLU and major Candida species by both CLSI and EUCAST methods, (3) determination of essential (EA) and categorical agreement (CA) between CLSI and EUCAST methods, (4) correlation of MICs with outcomes from previously published data using CLSI and EUCAST methods, and (5) pharmacokinetic and pharmacodynamic considerations. We applied these findings to propose new species-specific CLSI CBPs for FLU and Candida. WT distributions from large collections of Candida revealed similar ECVs by both CLSI and EUCAST methods (0.5-1 mcg/ml for C. albicans, 2 mcg/ml for C. parapsilosis and C. tropicalis, 32 mcg/ml for C. glabrata, and 64-128 for C. krusei). Comparison of CLSI and EUCAST MICs reveal EA and CA of 95% and 96%, respectively. Datasets correlating CLSI and EUCAST FLU MICs with outcomes revealed decreased response rates when MICs were > 4 mcg/ml for C. albicans, C. tropicalis and C. parapsilosis, and > 16 mcg/ml for C. glabrata. Adjusted CLSI CBPs for FLU and C. albicans, C. parapsilosis, C. tropicalis (S, ≤ 2 mcg/ml; SDD, 4 mcg/ml; R, ≥ 8 mcg/ml), and C. glabrata (SDD, ≤ 32 mcg/ml; R, ≥ 64 mcg/ml) should be more sensitive for detecting emerging resistance among common Candida species and provide consistency with EUCAST CBPs. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2012-06-01

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

  19. International and multicenter comparison of EUCAST and CLSI M27-A2 broth microdilution methods for testing susceptibilities of Candida spp. to fluconazole, itraconazole, posaconazole, and voriconazole.

    Science.gov (United States)

    Espinel-Ingroff, A; Barchiesi, F; Cuenca-Estrella, M; Pfaller, M A; Rinaldi, M; Rodriguez-Tudela, J L; Verweij, P E

    2005-08-01

    The aim of this study was to compare MICs of fluconazole, itraconazole, posaconazole, and voriconazole obtained by the European Committee on Antibiotic Susceptibility Testing (EUCAST) and CLSI (formerly NCCLS) methods in each of six centers for 15 Candida albicans (5 fluconazole-resistant and 4 susceptible-dose-dependent [S-DD] isolates), 10 C. dubliniensis, 7 C. glabrata (2 fluconazole-resistant isolates), 5 C. guilliermondii (2 fluconazole-resistant isolates), 10 C. krusei, 9 C. lusitaniae, 10 C. parapsilosis, and 5 C. tropicalis (1 fluconazole-resistant isolate) isolates. CLSI MICs were obtained visually at 24 and 48 h and spectrophotometric EUCAST MICs at 24 h. The agreement (within a 3-dilution range) between the methods was species, drug, and incubation time dependent and due to lower EUCAST than CLSI MICs: overall, 94 to 95% with fluconazole and voriconazole and 90 to 91% with posaconazole and itraconazole when EUCAST MICs were compared against 24-h CLSI results. The agreement was lower (85 to 94%) against 48-h CLSI endpoints. The overall interlaboratory reproducibility by each method was > or =92%. When the comparison was based on CLSI breakpoint categorization, the agreement was 68 to 76% for three of the four species that included fluconazole-resistant and S-DD isolates; 9% very major discrepancies ( or =64 microg/ml) were observed among fluconazole-resistant isolates and 50% with voriconazole ( or =4 microg/ml). Similar results were observed with itraconazole for seven of the eight species evaluated (28 to 77% categorical agreement). Posaconazole EUCAST MICs were also substantially lower than CLSI MIC modes (0.008 to 1 microg/ml versus 1 to > or =8 microg/ml) for some of these isolates. Therefore, the CLSI breakpoints should not be used to interpret EUCAST MIC data.

  20. In Vitro Activity of a Novel Broad-Spectrum Antifungal, E1210, Tested against Aspergillus spp. Determined by CLSI and EUCAST Broth Microdilution Methods

    Science.gov (United States)

    Pfaller, Michael A.; Duncanson, Frederick; Messer, Shawn A.; Moet, Gary J.; Jones, Ronald N.; Castanheira, Mariana

    2011-01-01

    E1210 is a first-in-class broad-spectrum antifungal that suppresses hyphal growth by inhibiting fungal glycophosphatidylinositol (GPI) biosynthesis. In the present study, we extend these findings by examining the activity of E1210 and comparator antifungal agents against Aspergillus spp. by using the methods of the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) to test wild-type (WT) as well as amphotericin B (AMB)-resistant (-R) and azole-R strains (as determined by CLSI methods). Seventy-eight clinical isolates of Aspergillus were tested including 20 isolates of Aspergillus flavus species complex (SC), 22 of A. fumigatus SC, 13 of A. niger SC, and 23 of A. terreus SC. The collection included 15 AMB-R (MIC, ≥2 μg/ml) isolates of A. terreus SC and 10 itraconazole-R (MIC, ≥4 μg/ml) isolates of A. fumigatus SC (7 isolates), A. niger SC (2 isolates), and A. terreus SC (1 isolate). Comparator antifungal agents included anidulafungin, caspofungin, amphotericin B, itraconazole, posaconzole, and voriconazole. Both CLSI and EUCAST methods were highly concordant for E1210 and all comparators. The essential agreement (EA; ±2 log2 dilution steps) was 100% for all comparisons with the exception of posaconazole versus A. terreus SC (EA = 91.3%). The minimum effective concentration (MEC)/MIC90 values (μg/ml) for E1210, anidulafungin, caspofungin, itraconazole, posaconazole, and voriconazole, respectively, were as follows for each species: for A. flavus SC, 0.03, ≤0.008, 0.12, 1, 1, and 1; for A. fumigatus SC, 0.06, 0.015, 0.12, >8, 1, and 4; for A. niger SC, 0.015, 0.03, 0.12, 4, 1, and 2; and for A. terreus SC, 0.06, 0.015, 0.12, 1, 0.5, and 1. E1210 was very active against AMB-R strains of A. terreus SC (MEC range, 0.015 to 0.06 μg/ml) and itraconazole-R strains of A. fumigatus SC (MEC range, 0.03 to 0.12 μg/ml), A. niger SC (MEC, 0.008 μg/ml), and A. terreus SC (MEC, 0.015

  1. In vitro activity of a novel broad-spectrum antifungal, E1210, tested against Aspergillus spp. determined by CLSI and EUCAST broth microdilution methods.

    Science.gov (United States)

    Pfaller, Michael A; Duncanson, Frederick; Messer, Shawn A; Moet, Gary J; Jones, Ronald N; Castanheira, Mariana

    2011-11-01

    E1210 is a first-in-class broad-spectrum antifungal that suppresses hyphal growth by inhibiting fungal glycophosphatidylinositol (GPI) biosynthesis. In the present study, we extend these findings by examining the activity of E1210 and comparator antifungal agents against Aspergillus spp. by using the methods of the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) to test wild-type (WT) as well as amphotericin B (AMB)-resistant (-R) and azole-R strains (as determined by CLSI methods). Seventy-eight clinical isolates of Aspergillus were tested including 20 isolates of Aspergillus flavus species complex (SC), 22 of A. fumigatus SC, 13 of A. niger SC, and 23 of A. terreus SC. The collection included 15 AMB-R (MIC, ≥ 2 μg/ml) isolates of A. terreus SC and 10 itraconazole-R (MIC, ≥ 4 μg/ml) isolates of A. fumigatus SC (7 isolates), A. niger SC (2 isolates), and A. terreus SC (1 isolate). Comparator antifungal agents included anidulafungin, caspofungin, amphotericin B, itraconazole, posaconzole, and voriconazole. Both CLSI and EUCAST methods were highly concordant for E1210 and all comparators. The essential agreement (EA; ± 2 log(2) dilution steps) was 100% for all comparisons with the exception of posaconazole versus A. terreus SC (EA = 91.3%). The minimum effective concentration (MEC)/MIC(90) values (μg/ml) for E1210, anidulafungin, caspofungin, itraconazole, posaconazole, and voriconazole, respectively, were as follows for each species: for A. flavus SC, 0.03, ≤ 0.008, 0.12, 1, 1, and 1; for A. fumigatus SC, 0.06, 0.015, 0.12, >8, 1, and 4; for A. niger SC, 0.015, 0.03, 0.12, 4, 1, and 2; and for A. terreus SC, 0.06, 0.015, 0.12, 1, 0.5, and 1. E1210 was very active against AMB-R strains of A. terreus SC (MEC range, 0.015 to 0.06 μg/ml) and itraconazole-R strains of A. fumigatus SC (MEC range, 0.03 to 0.12 μg/ml), A. niger SC (MEC, 0.008 μg/ml), and A. terreus SC (MEC, 0.015

  2. In vitro activity of a novel broad-spectrum antifungal, E1210, tested against Candida spp. as determined by CLSI broth microdilution method.

    Science.gov (United States)

    Pfaller, Michael A; Hata, Katsura; Jones, Ronald N; Messer, Shawn A; Moet, Gary J; Castanheira, Mariana

    2011-10-01

    The in vitro activity of the novel antifungal agent E1210 and four comparators (caspofungin, fluconazole, posaconazole, and voriconazole) was determined against 90 clinical isolates of Candida using Clinical and Laboratory Standards Institute methods. The collection was composed of 21 Candida albicans, 20 C. glabrata, 25 C. parapsilosis, and 24 C. tropicals, and also included 21 fluconazole-resistant and 15 caspofungin-resistant strains. E1210 was highly active against all the species tested and was more potent than all comparators. The MIC(90) results (μg/mL) for E1210, caspofungin, fluconazole, posaconazole, and voriconazole, respectively, were as follows by species: C. albicans (0.06, 4, ≥64, 0.5, 0.5), C. glabrata (0.06, 2, 32, 1, 1), C. parapsilosis (0.06, 4, 16, 0.12, 0.25), and C. tropicalis (0.06, 4, ≥64, 0.5, 2). E1210 was also the most active agent against fluconazole-resistant strains of C. albicans (MIC range, 0.015-0.12 μg/mL), C. glabrata (0.06 μg/mL), C. parapsilosis (MIC range, 0.06-0.05 μg/mL), and C. tropicalis (MIC range, 0.008-0.06 μg/mL), and was the most potent agent tested against caspofungin-resistant strains of C. albicans (MIC range, 0.008-0.12 μg/mL), C. glabrata (MIC range, 0.03-0.06 μg/mL), and C. tropicalis (MIC range, 0.015-0.06 μg/mL). Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Comparing Etest and Broth Microdilution for Antifungal Susceptibility Testing of the Most-Relevant Pathogenic Molds.

    Science.gov (United States)

    Lamoth, Frédéric; Alexander, Barbara D

    2015-10-01

    Invasive mold infections are life-threatening diseases for which appropriate antifungal therapy is crucial. Their epidemiology is evolving, with the emergence of triazole-resistant Aspergillus spp. and multidrug-resistant non-Aspergillus molds. Despite the lack of interpretive criteria, antifungal susceptibility testing of molds may be useful in guiding antifungal therapy. The standard broth microdilution method (BMD) is demanding and requires expertise. We assessed the performance of a commercialized gradient diffusion method (Etest method) as an alternative to BMD. The MICs or minimal effective concentrations (MECs) of amphotericin B, voriconazole, posaconazole, caspofungin, and micafungin were assessed for 290 clinical isolates of the most representative pathogenic molds (154 Aspergillus and 136 non-Aspergillus isolates) with the BMD and Etest methods. Essential agreements (EAs) within ±2 dilutions of ≥90% between the two methods were considered acceptable. EAs for amphotericin B and voriconazole were >90% for most potentially susceptible species. For posaconazole, the correlation was acceptable for Mucoromycotina but Etest MIC values were consistently lower for Aspergillus spp. (EAs of 16 μg/ml) strains. However, MEC determinations lacked consistency between methods for strains exhibiting mid-range MECs for echinocandins. We concluded that the Etest method is an appropriate alternative to BMD for antifungal susceptibility testing of molds under specific circumstances, including testing with amphotericin B or triazoles for non-Aspergillus molds (Mucoromycotina and Fusarium spp.). Additional study of molecularly characterized triazole-resistant Aspergillus isolates is required to confirm the ability of the Etest method to detect voriconazole and posaconazole resistance among Aspergillus spp. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. Comparison of E-test with broth microdilution and disk diffusion for susceptibility testing of coryneform bacteria.

    Science.gov (United States)

    Martínez-Martínez, L; Ortega, M C; Suárez, A I

    1995-05-01

    The susceptibilities of 135 coryneform bacteria isolated from clinical samples to ampicillin (AMP), cephalothin (CR), cefoxitin (FOX), cefotaxime (CTX), erythromycin (E), ciprofloxacin (CIP), tetracycline (TE), amikacin (AK), vancomycin (VA), and rifampin (R) were determined by disk diffusion, broth microdilution, and the E-test. The following species (number of isolates in parentheses) were included: Corynebacterium urealyticum (30), Corynebacterium minutissimum (20), coryneform CDC group ANF-1 (20), Corynebacterium striatum (20), Corynebacterium jeikeium (15), coryneform CDC group I2 (8), Listeria monocytogenes (7), Corynebacterium xerosis (5), and other coryneform bacteria (10). Agreement within one twofold dilution between the E-test and broth microdilution was 31% (VA), 64% (AK), 71% (CTX), 77% (FOX and CIP), 79% (TE), 84% (AMP), 87% (E), and 88% (CR and R). For the 1,350 combinations of microorganisms and antimicrobial agents, 85 (6.3%) discrepancies in interpretive category were found (4.2% minor, 1.2% major, and 0.9% very major). Seventy (5.1%) disagreements in interpretive category were found between disk diffusion and the E-test (3.8% minor, 0.4% major, and 0.9% very major), and 85 (6.3%) disagreements were found between microdilution (reference method) and disk diffusion (4.2% minor, 0.5% major, and 1.5% very major). MICs obtained with the E-test were highly reproducible. No category discrepancy was observed for VA, despite quantitative results. Considering interpretive categories, there is a good overall agreement between the three methods studied here, but further evaluation of current methodologies for susceptibility testing is required when considering coryneform bacteria and determination of quantitative activity of antimicrobial agents.

  5. Early detection of oxacillin-resistant staphylococcal strains with hypertonic broth diluent for microdilution panels.

    Science.gov (United States)

    Dillon, L K; Howe, S E

    1984-01-01

    A total of 292 coagulase-positive and 111 coagulase-negative staphylococcal strains were tested in microdilution MIC panels containing 16 to 0.13 microgram of oxacillin per ml diluted in cation-supplemented Mueller-Hinton broth with and without an additional 2% NaCl. All strains were tested using the stationary-phase inoculum procedure with an incubation temperature of 35 degrees C. Test results were recorded after 16 to 20 h of incubation; staphylococcal strains susceptible to oxacillin (less than or equal to 2 micrograms/ml) were reincubated for 20 to 24 h, and endpoints were determined again. Oxacillin resistance was found in 27 (9%) of the 292 coagulase-positive strains and 39 (35%) of the 111 coagulase-negative strains. Of these resistant strains, 5 (19%) of the 27 coagulase-positive strains and 13 (33%) of the 39 coagulase-negative strains were detected 24 h earlier in cation-supplemented Mueller-Hinton broth with 2% NaCl than in cation-supplemented Mueller-Hinton broth without the additional NaCl. However, 9 (33%) of the 27 resistant coagulase-positive strains and 10 (26%) of the 39 resistant coagulase-negative strains were detected only after an additional 24 h of incubation. Oxacillin MICs for the 265 coagulase-positive susceptible strains and 72 coagulase-negative susceptible strains were not affected by the additional 2% NaCl. These results support the utility of adding 2% NaCl to the broth diluent for the early detection of oxacillin-resistant staphylococcal strains and the necessity of extended incubation for those strains which initially appear to be susceptible to oxacillin after only 16 to 20 h of incubation. PMID:6562124

  6. Antibiotic susceptibility of members of the Lactobacillus acidophilus group using broth microdilution and molecular identification of their resistance determinants

    NARCIS (Netherlands)

    Mayrhofer, S.; Hoek, van A.H.A.M.; Mair, C.; Huys, G.; Aarts, H.J.M.; Kneifel, W.; Domig, K.J.

    2010-01-01

    The range of antibiotic susceptibility to 13 antibiotics in 101 strains of the Lactobacillus acidophilus group was examined using the lactic acid bacteria susceptibility test medium (LSM) and broth microdilution. Additionally, microarray analysis and PCR were applied to identify resistance genes

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

    Science.gov (United States)

    Mirajkar, Nandita S; Gebhart, Connie J

    2016-03-01

    Production-limiting diseases in swine caused by Brachyspira are characterized by mucohemorrhagic diarrhea (B. hyodysenteriae and "B. hampsonii") or mild colitis (B. pilosicoli), while B. murdochii is often isolated from healthy pigs. Emergence of novel pathogenic Brachyspira species and strains with reduced susceptibility to commonly used antimicrobials has reinforced the need for standardized susceptibility testing. Two methods are currently used for Brachyspira susceptibility testing: agar dilution (AD) and broth microdilution (BMD). However, these tests have primarily been used for B. hyodysenteriae and rarely for B. pilosicoli. Information on the use of commercial susceptibility testing products such as antibiotic gradient strips is lacking. Our main objective was to validate and compare the susceptibility results, measured as the minimum inhibitory concentration (MIC), of 6 antimicrobials for 4 Brachyspira species (B. hyodysenteriae, "B. hampsonii", B. pilosicoli, and B. murdochii) by BMD and AD (tiamulin, valnemulin, lincomycin, tylosin, and carbadox) or antibiotic gradient strip (doxycycline) methods. In general, the results of a high percentage of all 4 Brachyspira species differed by ±1 log2 dilution or less by BMD and AD for tiamulin, valnemulin, lincomycin, and tylosin, and by BMD and antibiotic gradient strip for doxycycline. The carbadox MICs obtained by BMD were 1-5 doubling dilutions different than those obtained by AD. BMD for Brachyspira was quicker to perform with less ambiguous interpretation of results when compared with AD and antibiotic gradient strip methods, and the results confirm the utility of BMD in routine diagnostics. © 2016 The Author(s).

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

    Science.gov (United States)

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

    2017-03-01

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

  9. In Vitro Comparison of Ertapenem, Meropenem, and Imipenem against Isolates of Rapidly Growing Mycobacteria and Nocardia by Use of Broth Microdilution and Etest.

    Science.gov (United States)

    Brown-Elliott, Barbara A; Killingley, Jessica; Vasireddy, Sruthi; Bridge, Linda; Wallace, Richard J

    2016-06-01

    We compared the activities of the carbapenems ertapenem, meropenem, and imipenem against 180 isolates of rapidly growing mycobacteria (RGM) and 170 isolates of Nocardia using the Clinical and Laboratory Standards Institute (CLSI) guidelines. A subset of isolates was tested using the Etest. The rate of susceptibility to ertapenem and meropenem was limited and less than that to imipenem for the RGM. Analysis of major and minor discrepancies revealed that >90% of the isolates of Nocardia had higher MICs by the broth microdilution method than by Etest, in contrast to the lower broth microdilution MICs seen for >80% of the RGM. Imipenem remains the most active carbapenem against RGM, including Mycobacterium abscessus subsp. abscessus For Nocardia, imipenem was significantly more active only against Nocardia farcinica Although there may be utility in testing the activities of the newer carbapenems against Nocardia, their activities against the RGM should not be routinely tested. Testing by Etest is not recommended by the CLSI. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  10. Ultrasound assisted extraction of phenolic acids from broccoli vegetable and using sonochemistry for preparation of MOF-5 nanocubes: Comparative study based on micro-dilution broth and plate count method for synergism antibacterial effect.

    Science.gov (United States)

    Pezeshkpour, Vahid; Khosravani, Seyed Abdolmajid; Ghaedi, Mehrorang; Dashtian, Kheibar; Zare, Fahimeh; Sharifi, Asghar; Jannesar, Ramin; Zoladl, Mohammad

    2018-01-01

    The aim of this work was comparison study of dilution and plating method for evaluation of the synergism effect of metal-organic framework nanocubes (MOF-5-NCs) and broccoli extract (Brassica oleracea) on antibacterial activity of standard and clinical Pseudomonas aeruginosa strains. For this purpose, sonochemical synthesis of MOF-5-NCs was performed and it was characterized using XRD, FT-IR, FESEM and EDS techniques. Maceration extraction (ME) and ultrasound assisted extraction (UAE) methods in three different solvents were prepared and applicability of their extracts were compared in some cases such as radical scavenging and antioxidant activity. The HPLC/UV analysis was applied for separation, identification and evaluation of phenolic acids in prepared broccoli extracts. Then, antimicrobial activity of MOF-5NCs and broccoli extract against gram-negative bacteria, Pseudomonas aeruginosa was evaluated by detection of minimal inhibition concentration (MIC), minimal bactericidal concentration (MBC) and zone of inhibition (ZOI). The results of in vitro assays showed that dilution method due to flase estimation of 4% viability percentage which is not logic by consideration of MBC well could not be able to estimate MBC. Therefore, plate count method was performed for precise calculation of MBC. MIC of broccoli extract and MOF-5-NCs on Pseudomonas aeruginosa strains were 7.81mgmL -1 and 3.13mgmL -1 , respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Comparison of in vitro activity of five antifungal agents against dermatophytes, using the agar dilution and broth microdilution methods Comparação da atividade in vitro de cinco agentes antifúngicos para dermatófitos, usando os métodos de diluição em ágar e microdiluição em caldo

    Directory of Open Access Journals (Sweden)

    Crystiane Rodrigues Araújo Mota

    2009-06-01

    Full Text Available The purpose of this study was to compare the agar dilution and broth microdilution methods for determining the minimum inhibitory concentration (MIC of fluconazole, itraconazole, ketoconazole, griseofulvin and terbinafine for 60 dermatophyte samples belonging to the species Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. The percentage agreement between the two methods, for all the isolates with O propósito do presente trabalho foi comparar os métodos de diluição em ágar e diluição em caldo para a determinação de concentração inibitória mínima de fluconazol, itraconazol, cetoconazol, griseofulvina e terbinafina para 60 amostras de dermatófitos pertencentes às espécies, Trichophyton rubrum, Trichophyton. mentagrophytes e Microsporum canis. A porcentagem de acordo entre os dois métodos para todos os isolados testados considerando-se valores < 2 diluições, foram de 91,6% para cetoconazol e para griseofulvina, de 88,3% para itraconazol, de 81,6% para terbinafina e de 73,3% para fluconazol. Uma concordância de 100% foi obtido para isolados de Trichophyton mentagrophytes avaliados com cetoconazol e griseofulvina. Desta forma, até que um método de referência seja padronizado para testar a suscetibilidade in vitro para os dermatófitos, os resultados semelhantes encontrados para os dois métodos fazem com que o método de diluição em ágar possa ser útil no teste de suscetibilidade para estes fungos filamentosos.

  12. Standardized broth microdilution antimicrobial susceptibility testing of Francisella tularensis subsp. holarctica strains from Europe and rare Francisella species.

    Science.gov (United States)

    Georgi, Enrico; Schacht, Erik; Scholz, Holger C; Splettstoesser, Wolf D

    2012-10-01

    Tularaemia is a widespread zoonosis in Europe caused by Francisella tularensis subsp. holarctica. Because of a lack of standardized CLSI-approved antibiotic susceptibility data from European Francisella strains, the antibiotic susceptibilities of a selection of F. tularensis subsp. holarctica isolates originating from Germany, Austria, France, Spain and other European countries were determined. Rarely isolated species and subspecies of Francisella such as Francisella philomiragia, F. tularensis subsp. novicida and F. tularensis subsp. mediasiatica as well as the type strain of Francisella hispaniensis were included in this study. MIC data were obtained using cation-adjusted Mueller-Hinton broth with a 2% growth supplement. The broth microdilution testing system comprised 14 antibiotics, including gentamicin, streptomycin, ciprofloxacin and tetracycline. All of the 91 strains tested were susceptible to aminoglycosides, quinolones, tetracycline and chloramphenicol. The antimicrobial susceptibility of rare Francisellae was similar to the antibiotic profile of F. tularensis subsp. holarctica strains. For erythromycin, we detected two geographically distinct groups of F. tularensis subsp. holarctica isolates in western Europe. One group was resistant and the other one was susceptible. Both groups overlapped in a small region in Germany. Being performed in accordance with CLSI criteria, this study provides reliable data on antibiotic susceptibility patterns of European Francisella isolates. The standardized methodology of this study can be used for testing of suspicious colonies from clinical specimens for therapeutic guidance. Based on the results, aminoglycosides or quinolones are recommended as first-choice antibiotics for the therapy of F. hispaniensis, F. philomiragia or F. tularensis subsp. novicida infections in immunocompromised patients.

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

    Science.gov (United States)

    Kathuria, Shallu; Singh, Pradeep K.; Sharma, Cheshta; Prakash, Anupam; Masih, Aradhana; Kumar, Anil

    2015-01-01

    Candida auris is a multidrug-resistant yeast that causes a wide spectrum of infections, especially in intensive care settings. We investigated C. auris prevalence among 102 clinical isolates previously identified as Candida haemulonii or Candida famata by the Vitek 2 system. Internal transcribed spacer region (ITS) sequencing confirmed 88.2% of the isolates as C. auris, and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) easily separated all related species, viz., C. auris (n = 90), C. haemulonii (n = 6), C. haemulonii var. vulnera (n = 1), and Candida duobushaemulonii (n = 5). The in vitro antifungal susceptibility was determined using CLSI broth microdilution (CLSI-BMD), the Vitek 2 antifungal susceptibility test, and the Etest method. C. auris isolates revealed uniformly elevated fluconazole MICs (MIC50, 64 μg/ml), and an alarming percentage of isolates (37%) exhibited elevated caspofungin MICs by CLSI-BMD. Notably, 34% of C. auris isolates had coexisting elevated MICs (≥2 μg/ml) for both fluconazole and voriconazole, and 10% of the isolates had elevated coexisting MICs (≥2 μg/ml) to two additional azoles, i.e., posaconazole and isavuconazole. In contrast to reduced amphotericin B MICs by CLSI-BMD (MIC50, 1 μg/ml) for C. auris, elevated MICs were noted by Vitek 2 (MIC50, 8 μg/ml), which were statistically significant. Candida auris remains an unnoticed pathogen in routine microbiology laboratories, as 90% of the isolates characterized by commercial identification systems are misidentified as C. haemulonii. MALDI-TOF MS proved to be a more robust diagnostic technique for rapid identification of C. auris. Considering that misleading elevated MICs of amphotericin B by the Vitek AST-YS07 card may lead to the selection of inappropriate therapy, a cautionary approach is recommended for laboratories relying on commercial systems for identification and antifungal susceptibility testing of rare yeasts. PMID:25809970

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

    Directory of Open Access Journals (Sweden)

    Emerson Roberto Siqueira

    2008-02-01

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

  15. Avaliação das metodologias M.I.C.E.®, Etest® e microdiluição em caldo para determinação da CIM em isolados clínicos Evaluation of M.I.C.E.TM, Etest® and CLSI broth microdilution methods for antimicrobial susceptibility testing of nosocomial bacterial isolates

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    Eloiza Helena Campana

    2011-04-01

    .I.C.E., Thermo Fisher Scientific, Basingstoke, UK, recently released into the market, represents a rapid alternative to antimicrobial susceptibility testing. OBJECTIVE: The objective of this study was to evaluate the performance of M.I.C.E. methodology in relation to broth microdilution (reference test and Etest® (BioMérieux, Marcy l'Étoile, France. Material and method: A total of 160 bacterial isolates were collected comprising the following species: P. aeruginosa (20, Acinetobacter spp. (20, K. pneumoniae (20, E. coli (20, S. aureus (20, coagulase-negative Staphylococcus (20, E. faecalis (20 and E. faecium (20. Following Clinical Laboratory Standands Institute (CLSI standards (2009 and the manufacturers' recommendations, antimicrobial susceptibility testing was performed using broth microdilution method, Etest and M.I.C.E. The results were interpreted according to the criteria established by CLSI and compared through regression analysis. RESULTS: All antimicrobial combinations vs. bacterial species were evaluated and M.I.C.E. methodology yielded good results with general correlation (MIC variation ± 1-log2 > 90%, except for cefotaxime (85% and vancomycin (76.3% when compared with the reference method. The M.I.C.E. results compared to Etest showed general correlation (> 96%, except for amoxicillin/clavulanic acid (67.5% combination. CONCLUSION: AST results obtained from M.I.C.E. methodology showed a good correlation with those from broth microdilution and Etest, which corroborates its time effectiveness in the determination of MIC. However, the combination of amoxicillin/clavulanic acid requires further attention.

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

    Science.gov (United States)

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

    2015-06-01

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

  17. Antifungal Susceptibility of 205 Candida spp. Isolated Primarily during Invasive Candidiasis and Comparison of the Vitek 2 System with the CLSI Broth Microdilution and Etest Methods▿

    Science.gov (United States)

    Bourgeois, N.; Dehandschoewercker, L.; Bertout, S.; Bousquet, P.-J.; Rispail, P.; Lachaud, L.

    2010-01-01

    Infections due to Candida spp. are frequent, particularly in immunocompromised and intensive care unit patients. Antifungal susceptibility tests are now required to optimize antifungal treatment given the emergence of acquired antifungal resistance in some Candida species. An antifungal susceptibility automated method, the Vitek 2 system (VK2), was evaluated. VK2 was compared to the CLSI broth microdilution reference method and the Etest procedure. For this purpose, 205 clinical isolates of Candida spp., including 11 different species, were tested for fluconazole, voriconazole, and amphotericin B susceptibility. For azoles, essential agreement ranged from 25% to 100%, depending on the method used and the Candida species tested. Categorical agreements for all of the species averaged 92.2% and ranged from 14.3 to 100%, depending on the 24-h or 48-h MIC reading by the Etest and CLSI methods and on the Candida species. Results obtained for Candida albicans showed excellent categorical and essential agreements with the two comparative methods. For Candida glabrata, the essential agreement was high with the CLSI method but low with the Etest method, and several very major errors in interpretation were observed between VK2 and the Etest method for both azoles. Low MICs of fluconazole were obtained for all of the Candida krusei isolates, but the VK2 expert software corrected all of the results obtained to resistant. Amphotericin B results showed MICs of ≤1 mg/liter for 201 (VK2), 190 (CLSI), and 202 (Etest) isolates. The AST-YS01 Vitek 2 card system (bioMérieux) is a reliable and practical standardized automated antifungal susceptibility test. Nevertheless, more assays are needed to better evaluate C. glabrata fluconazole sensitivity. PMID:19889902

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

    Directory of Open Access Journals (Sweden)

    Crystiane Rodrigues Araújo

    2009-02-01

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

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

    Science.gov (United States)

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

    2016-01-01

    Carbapenems-resistance in Pseudomonas aeruginosa isolates has been widely reported. Fosfomycin has been shown to act synergistically with other antimicrobials. The agar dilution method was approved for susceptibility testing for fosfomycin and Pseudomonas aeruginosa. However, broth microdilution methods are the basis of systems currently used in clinical microbiology laboratories. The results of this study indicate that these methods are acceptable as susceptibility testing methods for fosfomycin against these organisms. Copyright © 2016. Publicado por Elsevier España, S.L.U.

  20. 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

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    Cristiane Yumi Koga-Ito

    2008-02-01

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

  1. In vitro evaluation of Malassezia pachydermatis susceptibility to azole compounds using E-test and CLSI microdilution methods.

    Science.gov (United States)

    Cafarchia, Claudia; Figueredo, Luciana A; Iatta, Roberta; Colao, Valeriana; Montagna, Maria T; Otranto, Domenico

    2012-11-01

    Dermatitis caused by Malassezia spp., one of most common skin disease in dogs, requires prolonged therapy and/or high doses of antifungal agents. In the present study, the antifungal susceptibility of M. pachydermatis to ketoconazole (KTZ), fluconazole (FLZ), itraconazole (ITZ), posaconazole (POS) and voriconazole (VOR) was evaluated in vitro using both CLSI reference broth microdilution (CLSI BMD) and E-test. A total of 62 M. pachydermatis strains from dogs with and without skin lesions were tested. M. pachydermatis strains were susceptible to ITZ, KTZ and POS using both test methods, with the highest MIC found in tests of FLZ. Essential agreement between the two methods ranged from 87.1% (VOR) to 91.9% (ITZ), and categorical agreement from 74.2% (FLZ) to 96.8% (ITZ). Minor error discrepancies were observed between the two methods, with major discrepancies observed for KTZ. A higher MIC(50) value for FLZ was noted with M. pachydermatis genotype B. The MICs(50) of M. pachydermatis genotype B for KTZ, VOR and POS were higher in isolates from dogs with skin lesions than those in isolates from animals without skin lesions. The results suggest a link between genotypes of M. pachydermatis and in vitro drug susceptibility. The categorical agreement for both E-test and CLSI BMD methods found in this investigation confirms the E-test as a reliable diagnostic method for routine use in clinical mycology laboratories.

  2. The agar microdilution method - a new method for antimicrobial susceptibility testing for essential oils and plant extracts.

    Science.gov (United States)

    Golus, J; Sawicki, R; Widelski, J; Ginalska, G

    2016-11-01

    To develop a new agar microdilution technique suitable for the assessment of the antimicrobial activity of natural plant products such as essential oils or plant extracts as well as to evaluate the antimicrobial effect of several essential oils and plant extracts. The proposed agar microdilution method was evolved on the basis of the CLSI agar dilution method, approved for conventional antimicrobials. However, this new method combines convenience and time/cost effectiveness typical for microtitre methods with the advantages of the agar dilution of hydrophobic or coloured substances. Different concentrations of the tested agents were added to Eppendorf tubes with molten Mueller-Hinton agar, vortexed and dispensed into the 96-well microplate in a small volume of 100 μl per well which allows for rapid, easy and economical preparation of samples as well as providing a uniform and stable dispersion without separation of the oil-water phases which occurs in methods with liquid medium. Next, the agar microdilution plates were inoculated with four reference bacterial strains. The results of our study demonstrated that the minimal inhibitory concentrations (MICs) were successfully determined using the agar microdilution method even with hydrophobic essential oils or strongly coloured plant extracts. The new agar microdilution method avoids the problems associated with testing of water insoluble, oily or strongly coloured plant natural products. Moreover, it enables the reliable, cheap and easy MIC determination of such agents. In the era of increasing antibiotic resistance high hopes are associated with new drugs of plant origin. However, the lack of standardized and reliable testing methods for assessing antibacterial activity of plant natural products causes impediment to research into this area. This study demonstrated that the agar microdilution method can be used successfully for testing oily and coloured substances. © 2016 The Society for Applied Microbiology.

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

    Science.gov (United States)

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

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

  4. [Comparison of microdilution and disk diffusion methods for the detection of fluconazole and voriconazole susceptibility against clinical Candida glabrata isolates and determination of changing susceptibility with new CLSI breakpoints].

    Science.gov (United States)

    Hazırolan, Gülşen; Sarıbaş, Zeynep; Arıkan Akdağlı, Sevtap

    2016-07-01

    Candida albicans is the most frequently isolated species as the causative agent of Candida infections. However, in recent years, the isolation rate of non-albicans Candida species have increased. In many centers, Candida glabrata is one of the commonly isolated non-albicans species of C.glabrata infections which are difficult-to-treat due to decreased susceptibility to fluconazole and cross-resistance to other azoles. The aims of this study were to determine the in vitro susceptibility profiles of clinical C.glabrata isolates against fluconazole and voriconazole by microdilution and disk diffusion methods and to evaluate the results with both the previous (CLSI) and current species-specific CLSI (Clinical and Laboratory Standards Institute) clinical breakpoints. A total of 70 C.glabrata strains isolated from clinical samples were included in the study. The identification of the isolates was performed by morphologic examination on cornmeal Tween 80 agar and assimilation profiles obtained by using ID32C (BioMérieux, France). Broth microdilution and disk diffusion methods were performed according to CLSI M27-A3 and CLSI M44-A2 documents, respectively. The results were evaluated according to CLSI M27-A3 and M44-A2 documents and new vs. species-specific CLSI breakpoints. By using both previous and new CLSI breakpoints, broth microdilution test results showed that voriconazole has greater in vitro activity than fluconazole against C.glabrata isolates. For the two drugs tested, very major error was not observed with disk diffusion method when microdilution method was considered as the reference method. Since "susceptible" category no more exists for fluconazole vs. C.glabrata, the isolates that were interpreted as susceptible by previous breakpoints were evaluated as susceptible-dose dependent by current CLSI breakpoints. Since species-specific breakpoints remain yet undetermined for voriconazole, comparative analysis was not possible for this agent. The results obtained

  5. Antimicrobial susceptibility testing of Australian isolates of Brachyspira hyodysenteriae using a new broth dilution method.

    Science.gov (United States)

    Karlsson, Märit; Oxberry, Sophy L; Hampson, David J

    2002-01-03

    The antimicrobial susceptibilities of 76 field isolates of Brachyspira hyodysenteriae from different states of Australia were tested in a newly developed broth dilution procedure. The antimicrobial agents used were tiamulin, valnemulin, tylosin, erythromycin, lincomycin and clindamycin. The results from the broth dilution susceptibility testing of 39 of the isolates were compared with results obtained for the same isolates using the agar dilution method. Amongst the isolates tested by broth dilution, 17 were from three farms and had been collected over a number of years. Their pulsed field gel electrophoresis pattern previously had been determined. The broth dilution technique was simple to use, less labor intensive than agar dilution, and gave clear end points. The results obtained using the two methods generally corresponded well, although in a few cases the MIC obtained by broth dilution were lower than those with agar dilution. For the 76 isolates tested by broth dilution, the MIC(90) (mg/l) was: tiamulin, 1; valnemulin, 0.5; tylosin>256; erythromycin>256; lincomycin, 64 and clindamycin, 16. Only minor differences in susceptibility patterns were found amongst isolates from different Australian states. Over all the isolates, and also amongst the isolates obtained from different years on the three farms, there was no trend for the susceptibility of the isolates to alter with time.

  6. Comparative performance of isolation methods using Preston broth, Bolton broth and their modifications for the detection of Campylobacter spp. from naturally contaminated fresh and frozen raw poultry meat.

    Science.gov (United States)

    Seliwiorstow, T; De Zutter, L; Houf, K; Botteldoorn, N; Baré, J; Van Damme, I

    2016-10-03

    The performance of different isolation methods was evaluated for the detection of Campylobacter from naturally contaminated raw poultry meat. Therefore, fresh and frozen poultry meat samples were analysed using the standard procedure (ISO 10272-1:2006), enrichment in Preston broth, and enrichment in modified Bolton broth (supplemented with (i) potassium clavulanate (C-BB), (ii) triclosan (T-BB), (iii) polymyxin B (P-BB)). The enrichment cultures were streaked onto both modified charcoal cefoperazone deoxycholate agar (mCCDA) and RAPID'Campylobacter agar (RCA). Moreover, direct plating on mCCDA and RCA was performed to quantify Campylobacter. In total, 33 out of 59 fresh retail meat samples (55.9%) were Campylobacter positive. For both fresh and frozen poultry meat samples, enrichment in Bolton broth (ISO 10272-1:2006) resulted in a higher number of positive samples than enrichment in Preston broth. Supplementation of Bolton broth with potassium clavulanate (C-BB) and triclosan (T-BB) enhanced the Campylobacter recovery from fresh poultry meat compared to non-supplemented Bolton broth, although the use of C-BB was less applicable than T-BB for Campylobacter recovery from frozen samples. Additionally, the use of RCA resulted in a higher isolation rate compared to mCCDA. The present study demonstrates the impact of culture medium on the recovery of Campylobacter from fresh and frozen naturally contaminated poultry meat samples and can support laboratories in choosing the most appropriate culturing method to detect Campylobacter. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. International Evaluation of MIC Distributions and Epidemiological Cutoff Value (ECV) Definitions for Fusarium Species Identified by Molecular Methods for the CLSI Broth Microdilution Method.

    Science.gov (United States)

    Espinel-Ingroff, A; Colombo, A L; Cordoba, S; Dufresne, P J; Fuller, J; Ghannoum, M; Gonzalez, G M; Guarro, J; Kidd, S E; Meis, J F; Melhem, T M S C; Pelaez, T; Pfaller, M A; Szeszs, M W; Takahaschi, J P; Tortorano, A M; Wiederhold, N P; Turnidge, J

    2016-02-01

    The CLSI epidemiological cutoff values (ECVs) of antifungal agents are available for various Candida spp., Aspergillus spp., and the Mucorales. However, those categorical endpoints have not been established for Fusarium spp., mostly due to the difficulties associated with collecting sufficient CLSI MICs for clinical isolates identified according to the currently recommended molecular DNA-PCR-based identification methodologies. CLSI MIC distributions were established for 53 Fusarium dimerum species complex (SC), 10 F. fujikuroi, 82 F. proliferatum, 20 F. incarnatum-F. equiseti SC, 226 F. oxysporum SC, 608 F. solani SC, and 151 F. verticillioides isolates originating in 17 laboratories (in Argentina, Australia, Brazil, Canada, Europe, Mexico, and the United States). According to the CLSI guidelines for ECV setting, ECVs encompassing ≥97.5% of pooled statistically modeled MIC distributions were as follows: for amphotericin B, 4 μg/ml (F. verticillioides) and 8 μg/ml (F. oxysporum SC and F. solani SC); for posaconazole, 2 μg/ml (F. verticillioides), 8 μg/ml (F. oxysporum SC), and 32 μg/ml (F. solani SC); for voriconazole, 4 μg/ml (F. verticillioides), 16 μg/ml (F. oxysporum SC), and 32 μg/ml (F. solani SC); and for itraconazole, 32 μg/ml (F. oxysporum SC and F. solani SC). Insufficient data precluded ECV definition for the other species. Although these ECVs could aid in detecting non-wild-type isolates with reduced susceptibility to the agents evaluated, the relationship between molecular mechanisms of resistance (gene mutations) and MICs still needs to be investigated for Fusarium spp. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  8. Comparing in vitro activity of tigecycline by using the disk diffusion test, the manual microdilution method, and the VITEK 2 automated system Comparación de la actividad in vitro de la tigeciclina mediante la prueba de difusión con disco, el método de microdilución manual y el sistema automatizado Vitek 2

    Directory of Open Access Journals (Sweden)

    A. L. Leal Castro

    2010-09-01

    Full Text Available Tigecycline is a broad spectrum antibiotic having activity against multiresistant isolates. In vitro susceptibility testing is difficult to perform with the use of traditional microbiological techniques. The aim of this study was to evaluate the disk diffusion test with three different Mueller-Hinton agar brands, and the Vitek 2 automated system in comparison with the standard broth microdilution method against 200 gram-negative isolates (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens and Acinetobacter baumannii. Among Enterobacteriaceae, the Becton Dickinson agar had the lowest rate of minor (32.5% and major errors (3.8%. No very major errors were found. For A. baumanni, the rate of minor and major errors was lower. A high rate of agreement (94% was found between the broth microdilution method and the Vitek 2 system. Our results show that there are important differences between agars used for the disk diffusion test, and that Vitek 2 is a valid tool for susceptibility testing in clinical laboratories.La tigeciclina es un antibiótico de amplio espectro con actividad frente a bacterias multirresistentes. Existen dificultades en la determinación de la actividad in vitro a través de las técnicas microbiológicas convencionales. El objetivo del estudio fue evaluar tres marcas diferentes de medio agar Mueller-Hinton para utilizar en el método de difusión con disco y el método automatizado Vitek 2, y compararlos con la prueba tradicional de microdilución manual (Paneles Trek frente a 200 aislamientos de microorganismos gram negativos (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens y Acinetobacter baumannii. Para el grupo de las enterobacterias, el medio con mejor desempeño fue el producido por Becton Dickinson, que tuvo 32,5% de errores menores y 3,8% de errores mayores. No se presentaron errores mayores con ningún medio. Se encontró una alta concordancia (94% entre el

  9. Xanthan GumRecovery from Palm Oil-Based Fermentation Broth by Hollow Fibre Microfiltration (MF) Membrane with ProcessOptimisation Using Taguchi Method

    OpenAIRE

    Sufian Soaib, M.; M. Sabet; Krishnan, J.; VPS Veluri, M.

    2013-01-01

    First stage Xanthan recovery (cell and oil separation) from palm oil-based fermentation broth was carried out by hollow fibre microfiltration (MF) using Taguchi method as design of experiment (DOE) to study the effect of four main parameters on Xanthan recovery; transmembrane pressure (TMP), crossflow velocity (CFV), ionic strength (IS) and temperature (T). From S/N ratio larger-the-better analysis, optimum conditions for Xanthan recovery were at level 2 of TMP, IS and T respectively and leve...

  10. Salmonella in foods: new enrichment procedure for TECRA Salmonella Visual Immunoassay using a single rv(R10) only, TT only, or dual rv(R10) and TT selective enrichment broths (AOAC official method 998.09): collaborative study.

    Science.gov (United States)

    Hughes, Denise; Dailianis, Angela E; Hill, Louise; Curiale, Michael S; Gangar, Vidhya

    2003-01-01

    A collaborative study was conducted to compare a new enrichment procedure for the TECRA Salmonella Visual Immunoassay (TSVIA) with the reference method given in the U.S. Food and Drug Administration's Bacteriological Analytical Manual (7th Ed.). Three food types (milk powder, pepper, and soy flour) were analyzed in Australia and 3 food types (milk chocolate, dried egg, and raw turkey) were analyzed in the United States. Thirty-eight collaborators participated in the study. The TECRA method was evaluated using both Rappaport-Vassiliadis R10 (RV(R10)) and tetrathionate (TT) broths for selective enrichment. M broth cultures arising from each of the 2 selective enrichment broths were tested in the TSVIA using 2 individual wells, one for each selective broth, and a single well to test the pooled selective enrichment broths. The results for the pooled enrichment broths were reported elsewhere. This study presents the results for the use of single enrichment broths, i.e., RV(R10) only or TT only, with the TSVIA. No significant differences (p > 0.05) were observed for the pairwise comparison of the proportion of positive samples for either RV(R10) or TT used as a single enrichment broth for the TSVIA with that for the reference method.

  11. Multicenter study of isavuconazole MIC distributions and epidemiological cutoff values for the Cryptococcus neoformans-Cryptococcus gattii species complex using the CLSI M27-A3 broth microdilution method

    NARCIS (Netherlands)

    Espinel-Ingroff, A.; Chowdhary, A.; Gonzalez, G.M.; Guinea, J.; Hagen, F.; Meis, J.F.G.M.; Thompson, G.R.; Turnidge, J.

    2015-01-01

    Epidemiological cutoff values (ECVs) of isavuconazole are not available for Cryptococcus spp. The isavuconazole ECVs based on wild-type (WT) MIC distributions for 438 Cryptococcus neoformans nongenotyped isolates, 870 isolates of genotype VNI, and 406 Cryptococcus gattii isolates from six

  12. Antimicrobial susceptibility testing of rapidly growing mycobacteria by microdilution - Experience of a tertiary care centre

    Directory of Open Access Journals (Sweden)

    Set R

    2010-01-01

    Full Text Available Purpose: The objective of the study was to perform antimicrobial susceptibility testing of rapidly growing mycobacteria (RGM isolated from various clinically suspected cases of extrapulmonary tuberculosis, from January 2007 to April 2008, at a tertiary care centre in Mumbai. Materials and Methods: The specimens were processed for microscopy and culture using the standard procedures. Minimum inhibitory concentrations (MIC were determined by broth microdilution, using Sensititre CA MHBT. Susceptibility testing was also carried out on Mueller Hinton agar by the Kirby Bauer disc diffusion method. Results: Of the 1062 specimens received for mycobacterial cultures, 104 (9.79% grew mycobacteria. Of the mycobacterial isolates, six (5.76% were rapid growers. M. abscessus and M. chelonae appeared to be resistant organisms, with M. chelonae showing intermediate resistance to amikacin and minocycline. However, all the six isolates showed sensitivity to vancomycin and gentamicin by the disc diffusion test. Also all three isolates of M. abscessus were sensitive to piperacillin and erythromycin. Further studies are required to test their sensitivity to these four antimicrobials by using the microbroth dilution test, before they can be prescribed to patients. Conclusions: We wish to emphasize that reporting of rapidly growing mycobacteria from clinical settings, along with their sensitivity patterns, is an absolute need of the hour.

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

    Directory of Open Access Journals (Sweden)

    E Takahagi-Nakaira

    2009-01-01

    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.

  14. A novel low-cost method for Mycobacterium avium subsp. paratuberculosis DNA extraction from an automated broth culture system for real-time PCR analysis.

    Science.gov (United States)

    Salgado, Miguel; Verdugo, Cristobal; Heuer, Cord; Castillo, Pedro; Zamorano, Patricia

    2014-01-01

    PCR is a highly accurate technique for confirming the presence of Mycobacterium avium subsp. paratuberculosis (Map) in broth culture. In this study, a simple, efficient, and low-cost method of harvesting DNA from Map cultured in liquid medium was developed. The proposed protocol (Universidad Austral de Chile [UACH]) was evaluated by comparing its performance to that of two traditional techniques (a QIAamp DNA Stool Mini Kit and cethyltrimethylammonium bromide [CTAB] method). The results were statistically assessed by agreement analysis for which differences in the number of cycles to positive (CP) were compared by Student's t-test for paired samples and regression analysis. Twelve out of 104 fecal pools cultured were positive. The final PCR results for 11 samples analyzed with the QIAamp and UACH methods or ones examined with the QIAamp and CTAB methods were in agreement. Complete (100%) agreement was observed between data from the CTAB and UACH methods. CP values for the UACH and CTAB techniques were not significantly different, while the UACH method yielded significantly lower CP values compared to the QIAamp kit. The proposed extraction method combines reliability and efficiency with simplicity and lower cost.

  15. Species of Genus Ganoderma (Agaricomycetes) Fermentation Broth: A Novel Antioxidant and Antimicrobial Agent.

    Science.gov (United States)

    Cilerdzic, Jasmina; Kosanic, Marijana; Stajić, Mirjana; Vukojevic, Jelena; Ranković, Branislav

    2016-01-01

    The bioactivity of Ganoderma lucidum basidiocarps has been well documented, but there are no data on the medicinal properties of its submerged cultivation broth nor on the other species of the genus Ganoderma. Thus the aim of this study was to test the potential antimicrobial and antioxidant activity of fermentation broth obtained after submerged cultivation of G. applanatum, G. carnosum, and G. lucidum. DPPH· scavenging ability, total phenols, and flavonoid contents were measured to determine the antioxidative potential of Ganoderma spp. fermentation filtrates, whereas their antimicrobial potential was studied using the microdilution method. DPPH· scavenging activity of G. lucidum fermentation filtrates was significantly higher than that of G. applanatum and G. carnosum, with the maximum (39.67%) obtained from strain BEOFB 432. This filtrate also contained the highest concentrations of phenols (134.89 μg gallic acid equivalents/mL) and flavonoids (42.20 μg quercetin equivalent/mL). High correlations between the activity and phenol content in the extracts showed that these compounds were active components of the antioxidative activity. G. lucidum strain BEOFB 432 was the most effective antibacterial agent, whereas strain BEOFB 434 has proven to be the most effective antifungal agent. The study showed that Ganoderma spp. fermentation filtrates are novel potent antioxidative and antimicrobial agents that could be obtained more quickly and cheaper than basidiocarps.

  16. Essential and toxic metals in animal bone broths.

    Science.gov (United States)

    Hsu, Der-Jen; Lee, Chia-Wei; Tsai, Wei-Choung; Chien, Yeh-Chung

    2017-01-01

    Background: This investigation examines the extraction of metals from animal bones into broth, and assesses whether bone broths are good sources of essential metals and the risks associated with the consumption of toxic metals. Method:Three sets of controlled experiments were performed to study the factors (cooking time, acidity, bone type and animal species) that influence metal extractions. Three types of animal bone broth-based foods were also tested. Results: Reducing the broth pH from 8.38 to 5.32 significantly (p 8 h, yielded significantly higher (p bones differed. The between-species variations in extraction were larger than those of within-species. Conclusions:The Ca and Mg levels in home-made or commercial broth/soup were found not to exceed low tenths of milligram per serving, or broth are minimal because the levels were in the ranges of a few μg per serving.

  17. Evaluation of TA10 Broth for Recovery of Listeria monocytogenes from Ground Beef.

    Science.gov (United States)

    Kamisaki-Horikoshi, Naoko; Okada, Yukio; Takeshita, Kazuko; Takada, Makoto; Kawamoto, Shinichi; Kawasaki, Susumu

    2017-03-01

    In 2009, the enrichment broth TA10 was released for simultaneous recovery of Salmonella spp., Listeria monocytogenes, and Escherichia coli O157:H7. This medium was compared with other Salmonella enrichment broths [lactose (LAC) broth, buffered peptone water (BPW), and universal pre-enrichment (UP) broth] for the recovery of heat- and freeze-injured Salmonella spp. in beef by the conventional culture method. There was a significant difference between TA10 and LAC enrichment broths for detecting injured Salmonella spp. In this study, the International Organization for Standardization Listeria pre-enrichment broth (Half-Fraser/Fraser) was compared with TA10 broth for the recovery of L. monocytogenes from ground beef. Ground beef samples were contaminated with single Listeria serovars at levels of 0.096 to 0.001 most probable number/g. Twenty 25 g test portions of the contaminated ground beef were pre-enriched in each broth, and the ISO-11290-1 Listeria official isolation protocol was used thereafter. There was a significant difference between TA10 broth (48 h) and Half-Fraser/Fraser broth (72 h) in the recovery of L. monocytogenes. In addition, the incubation time for TA10 broth was shorter than for Half-Fraser/Fraser broth. The results indicate that TA10 broth should be used instead of Half-Fraser/Fraser broth for analysis of beef that may be contaminated with very low levels of L. monocytogenes.

  18. In vitro effect of intracanal medicaments on strict anaerobes by means of the broth dilution method Efeito in vitro de medicações intracanal sobre anaeróbios estritos pelo método de diluição em caldo

    Directory of Open Access Journals (Sweden)

    Odila Pereira da Silva ROSA

    2002-03-01

    Full Text Available The determination of bacterial susceptibility to intracanal medicaments is a necessity. Nevertheless, few studies utilize the proper methodology to carry out that evaluation with anaerobes. In this study, the steps of a broth dilution method, carried out in microplates (microdilution and tubes (macrodilution, to test the effect of traditional intracanal medicaments on anaerobic bacteria are described. The results are presented as values of minimal inhibitory and bactericidal concentrations (MIC and MBC. Standardized inocula of the anaerobic bacteria Prevotella nigrescens (ATCC 33563, Fusobacterium nucleatum (ATCC 25586 and Clostridium perfringens (ATCC 13124, in reinforced Clostridium medium (RCM and supplemented Brucella broth, were submitted to different concentrations of calcium hydroxide, chlorhexidine digluconate, camphorated paramonochlorophenol and formocresol solutions. The drugs were diluted in the same culture broths, in microplates and tubes, and were then incubated in anaerobiosis jars at 37ºC for 48 or 96 hours. The determination of MICs was carried out through visual and spectrophotometric readings, and the determination of MBCs, through the plating of aliquots on RCM-blood agar. For that kind of study, the macromethod with spectrophotometric reading should be the natural choice. MICs and MBCs obtained with the macromethod were compatible with the known clinical performance of the studied medications, and the values varied according to the bacteria and culture media employed. RCM was the most effective medium and C. perfringens, the most resistant microorganism.A determinação da suscetibilidade bacteriana aos medicamentos intracanal é uma necessidade, mas são poucos os estudos que utilizam metodologia própria para anaeróbios estritos nessa avaliação. Neste estudo, são descritos os passos de um método de diluição em caldo, feito em microplacas (microdiluição e em tubo (macrodiluição, para testar a ação de

  19. Evaluation of a matrix-assisted laser desorption ionization-time of flight mass spectrometry assisted, selective broth method to screen for vancomycin-resistant enterococci in patients at high risk.

    Science.gov (United States)

    Huang, Tsi-Shu; Lee, Susan Shin-Jung; Lee, Chia-Chien; Chen, Chiu-Yen; Chen, Fang-Chen; Chen, Bao-Chen; Sy, Cheng Len; Wu, Kuan-Sheng

    2017-01-01

    Bile esculin azide with vancomycin (BEAV) medium is a sensitive, but slightly less specific method for vancomycin-resistant enterococci (VRE) screening. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid method for identification of clinical pathogens. This study aimed to assess the performance of a novel combination screening test for VRE, using BEAV broth combined with MALDI-TOF MS. Clinical specimens were collected from patients at risk of VRE carriage, and tested by the novel combination method, using selective BEAV broth culture method followed by MALDI-TOF MS identification (SBEAVM). The reference method used for comparison was the ChromID VRE agar method. A total of 135 specimens were collected from 78 patients, and 63 specimens tested positive for VRE positive using the ChromID VRE method (positive rate 46.7%). The sensitivity, specificity, positive predictive value, and negative predictive value of SBEAVM method after an incubation period of 28 hours were 93.7%, 90.3%, 89.4%, and 94.2%, respectively. The SBEAVM method when compared to the ChromID VRE method had a shorter turnaround time (29 vs. 48-72 hours) and lower laboratory cost ($2.11 vs. $3.23 per test). This study demonstrates that SBEAVM is a rapid, inexpensive, and accurate method for use in VRE screening.

  20. Comparison of methods for the determination of antimicrobial resistance in Staphylococcus aureus from bovine mastitis.

    Science.gov (United States)

    Schlegelova, J; Rysánek, D; Sedivá, I; Babák, V

    2001-02-01

    The results of three standard methods (broth dilution, agar dilution, disk diffusion) and an experimental modification of the microdilution method for determination of resistance to ampicillin, cephalotin, cloxacillin, neomycin, novobiocin, penicillin and streptomycin were compared using 151 Staphylococcus aureus isolates obtained from cases of mastitis. The accuracy of the dilution methods was compared by determination of minimum inhibition concentrations (MIC, MIC50, MIC90 and modal MIC) and by assessment of the agreement within the tolerance of +/-1 dilution step in 2-fold dilution series. The results of the dilution methods were further compared with those of the reference disk diffusion method and the strains were classified as sensitive or resistant using the interpretation criteria for human strains. The comparisons indicated that MIC characteristics and the final classification as sensitive or resistant were method-dependent. Resistance to aminoglycoside antibiotics was observed more often when using broth dilution methods, especially when the broth was supplemented with lactose.

  1. Ultra scale-down characterization of the impact of conditioning methods for harvested cell broths on clarification by continuous centrifugation-Recovery of domain antibodies from rec E. coli.

    Science.gov (United States)

    Chatel, Alex; Kumpalume, Peter; Hoare, Mike

    2014-05-01

    The processing of harvested E. coli cell broths is examined where the expressed protein product has been released into the extracellular space. Pre-treatment methods such as freeze-thaw, flocculation, and homogenization are studied. The resultant suspensions are characterized in terms of the particle size distribution, sensitivity to shear stress, rheology and solids volume fraction, and, using ultra scale-down methods, the predicted ability to clarify the material using industrial scale continuous flow centrifugation. A key finding was the potential of flocculation methods both to aid the recovery of the particles and to cause the selective precipitation of soluble contaminants. While the flocculated material is severely affected by process shear stress, the impact on the very fine end of the size distribution is relatively minor and hence the predicted performance was only diminished to a small extent, for example, from 99.9% to 99.7% clarification compared with 95% for autolysate and 65% for homogenate at equivalent centrifugation conditions. The lumped properties as represented by ultra scale-down centrifugation results were correlated with the basic properties affecting sedimentation including particle size distribution, suspension viscosity, and solids volume fraction. Grade efficiency relationships were used to allow for the particle and flow dynamics affecting capture in the centrifuge. The size distribution below a critical diameter dependent on the broth pre-treatment type was shown to be the main determining factor affecting the clarification achieved. © 2013 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

  2. Centrifugal partition extraction, a new method for direct metabolites recovery from culture broth: case study of torularhodin recovery from Rhodotorula rubra.

    Science.gov (United States)

    Ungureanu, Camelia; Marchal, Luc; Chirvase, Ana Aurelia; Foucault, Alain

    2013-03-01

    Centrifugal partition extraction (CPE), close to centrifugal partition chromatography, put in contact in a continuous way two immiscible liquid phases. This work presents early experiments on CPE use for solid-liquid-liquid extraction. It was applied to the direct treatment of culture broth for metabolites recovery. Torularhodin is one of the carotenoid pigments produced by the yeast Rhodotorula sp., with a terminal carboxylic group considered nowadays as a powerful antioxidant to be included in food and drugs formulations. Torularhodin was extracted from Rhodotorula rubra ICCF 209 cells by CPE. The recovery of torularhodin reaches 74 μg/g of biomass i.e. 294 μg/L of culture medium. The efficiency of the extraction step increased with the operating flow rate. The extraction yield could reach 91% with a contact time lower than 2 min. A 300 mL apparatus allowed a feed at 90 mL/min. The technique is proposed for extraction or sample preparation before analysis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Ultra Scale-Down Characterization of the Impact of Conditioning Methods for Harvested Cell Broths on Clarification by Continuous Centrifugation—Recovery of Domain Antibodies from rec E. coli

    Science.gov (United States)

    Chatel, Alex; Kumpalume, Peter; Hoare, Mike

    2014-01-01

    The processing of harvested E. coli cell broths is examined where the expressed protein product has been released into the extracellular space. Pre-treatment methods such as freeze–thaw, flocculation, and homogenization are studied. The resultant suspensions are characterized in terms of the particle size distribution, sensitivity to shear stress, rheology and solids volume fraction, and, using ultra scale-down methods, the predicted ability to clarify the material using industrial scale continuous flow centrifugation. A key finding was the potential of flocculation methods both to aid the recovery of the particles and to cause the selective precipitation of soluble contaminants. While the flocculated material is severely affected by process shear stress, the impact on the very fine end of the size distribution is relatively minor and hence the predicted performance was only diminished to a small extent, for example, from 99.9% to 99.7% clarification compared with 95% for autolysate and 65% for homogenate at equivalent centrifugation conditions. The lumped properties as represented by ultra scale-down centrifugation results were correlated with the basic properties affecting sedimentation including particle size distribution, suspension viscosity, and solids volume fraction. Grade efficiency relationships were used to allow for the particle and flow dynamics affecting capture in the centrifuge. The size distribution below a critical diameter dependant on the broth pre-treatment type was shown to be the main determining factor affecting the clarification achieved. Biotechnol. Bioeng. 2014;111: 913–924. © 2013 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. PMID:24284936

  4. Detection of Brucella melitensis by the BacT/Alert automated system and Brucella broth culture.

    Science.gov (United States)

    Ozkurt, Z; Erol, S; Tasyaran, M A; Kaya, A

    2002-11-01

    This study was conducted to evaluate the ability of the BacT/Alert automated blood culture system to detect Brucella spp. in comparison with traditional Brucella broth culture. Overall, 100 (50 bone marrow and 50 blood samples) paired cultures were obtained, and 59 were positive by at least one method. The Brucella broth culture method detected all 59 positive cultures (100%), and the BacT/Alert system detected 30 (50.8%) (P broth culture (P > 0.05). There is no significant difference between the two methods with respect to growth time of the microorganism, but Brucella broth culture is more sensitive than the BacT/Alert system.

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

    NARCIS (Netherlands)

    Kathuria, S.; Singh, P.K.; Sharma, C.; Prakash, A.; Masih, A.; Kumar, A.; Meis, J.F.G.M.; Chowdhary, A.

    2015-01-01

    Candida auris is a multidrug-resistant yeast that causes a wide spectrum of infections, especially in intensive care settings. We investigated C. auris prevalence among 102 clinical isolates previously identified as Candida haemulonii or Candida famata by the Vitek 2 system. Internal transcribed

  6. Imaging for monitoring downstream processing of fermentation broths

    DEFF Research Database (Denmark)

    Moiseyenko, Rayisa; Baum, Andreas; Jørgensen, Thomas Martini

    In relation to downstream processing of a fermentation broth coagulation/flocculation is a typical pretreatment method for separating undesirable particles/impurities from the wanted product. In the coagulation process the negatively charged impurities are destabilized by adding of a clarifying...

  7. Cultivation of Leishmania sp. in nutrient broth.

    Science.gov (United States)

    Ozbilgin, A; Ozbel, Y; Alkan, M Z; Atambay, M; Ozcel, M A

    1995-08-01

    Bone-marrow aspiration and biopsy material samples obtained from two patients, one diagnosed as visceral and other as cutaneous leishmaniasis, were inoculated in Novy, McNeal, Nicolle (NNN) medium and nutrient broth (NB), containing fetal calf serum (FCS), penicillin and streptomycine. Both media were incubated at 27 degrees C for 10 days and observed daily for L. infantum and L. major promastigotes. Promastigotes were observed in nutrient broth after the first day, while in NNN media after the second or third day of incubation, indicating the effectiveness of nutrient broth in early diagnosis of both forms of leishmaniasis.

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

    Directory of Open Access Journals (Sweden)

    Sultana Razia

    2016-08-01

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

  9. Microbiological culture broth designed from food waste.

    Science.gov (United States)

    Chalón, Miriam C; Terán, Victoria; Arena, Mario E; Oliszewki, Rubén; González, Silvia N

    2013-01-30

    The current trend of increasing air, water, and soil pollution is, in part, due to inadequate management of municipal solid waste (MSW). The relationship between public health and the collection, storage and improper disposal of solid waste has encouraged several studies and the results were attributed to the spread of over twenty human and animal diseases due to this interrelationship. The term "single cell protein" (SCP) refers to microbial biomass used as a dietary additive. It has high nutritional value because of its high content of vitamins, lipids, and proteins of biological quality (the presence of all essential amino acids) (Lal, 2005). The aim of this work was to design a culture media for microbiological assays and to produce SCP for animal feeding, using nutrients contained in organic waste. In order to compare the effectiveness of food waste (FW) and LAPTg media, different strains of Lactobacillus, Enterococcus, Staphylococcus, Shigella, Salmonella, Saccharomyces and Schizosaccharomyces were studied. In all cases, the growth obtained from FW and LAPTg culture media were not significantly different (p > 0.05). In addition, the growth of Saccharomyces cerevisiae was studied in order to produce SCP for animal feeding. Comparative experiments involving molasses broth, FW broth, and basal broth were carried out. The biomass yield calculated at 24 h from FW broth was 13% lower than from molasses broth. The FW broth provided a significantly lower biomass yield; however, it can be very useful in areas where molasses are not available. FW broth can be elaborated at low cost, in any populated region of the world because its ingredients are wastes generated by humans. It has great versatility, allowing the development of a wide variety of microorganisms, both Gram negative and Gram positive bacteria as well as yeasts. The production of safe protein additives, with high biological quality and low cost, is necessary due to the increasing global demand for food

  10. Separation technologies for the recovery and dehydration of alcohols from fermentation broths

    Science.gov (United States)

    Multi-column distillation followed by molecular sieve adsorption is currently the standard method for producing fuel grade ethanol from dilute fermentation broths in modern corn-to-ethnol facilities. As the liquid biofuels industry transitions to lignocellulosic feedstocks, expan...

  11. Pre-enrichment broths for recovery of Salmonella from milk chocolate and edible casein: collaborative study.

    Science.gov (United States)

    Poelma, P L; Andrews, W H; Wilson, C R

    1981-07-01

    A collaborative study was conducted to compare the relative efficiency of nonfat dry milk with brilliant green dye (NFDM-BG and buffered peptone water (BPW) as pre-enrichment broths for recovery of Salmonella from milk chocolate. Lactose broth and modified lactose broth with added 1% NaHCO3 and brilliant green dye were compared as pre-enrichment broths for recovery of Salmonella from edible casein. Two sets of 8 samples each of milk chocolate, containing initial levels of Salmonella ranging from less than 0.03 to 43 organisms/g, were examined by 13 collaborators. Of 104 determinations, 102 (98.1%) and 100 (96.2%) using NFDM-BG and BPW, respectively, were in agreement with sample results of the control laboratory. Two sets of 7 samples each of edible casein, containing initial levels of Salmonella ranging from less than 0.03 to 93 organisms/g, were also examined by the 13 collaborators. Of 91 determinations, 87 (95.6%) and 88 (96.7%) using lactose broth and modified lactose broth, respectively, were in agreement with sample results of the control laboratory. For recovery of Salmonella, therefore, NFDM-BG pre-enrichment is recommended for milk chocolate, and lactose broth is recommended for casein. The proposed revision of official final action method 46.054-46.067 has been adopted official first action.

  12. Use of broth cultures peri-operatively to optimise the microbiological diagnosis of musculoskeletal implant infections.

    Science.gov (United States)

    Blackmur, J P; Tang, E Y H; Dave, J; Simpson, A H R W

    2014-11-01

    We compared the use of broth culture medium for samples taken in theatre with the standard practice of placing tissue samples in universal containers. A total of 67 consecutive patients had standard multiple samples of deep tissue harvested at surgery and distributed equally in theatre either to standard universal containers or to broth culture medium. These samples were cultured by direct and enrichment methods. The addition of broth in theatre to standard practice led to an increase in sensitivity from 83% to 95% and an increase in negative predictive value from 77% to 91%. Placing tissue samples directly into broth in the operating theatre is a simple, inexpensive way to increase the sensitivity of cultures from infected patients, and does not appear to compromise the specificity of these cultures. ©2014 The British Editorial Society of Bone & Joint Surgery.

  13. Aerococcus urinae and Aerococcus sanguinicola: Susceptibility Testing of 120 Isolates to Six Antimicrobial Agents Using Disk Diffusion (EUCAST), Etest, and Broth Microdilution Techniques

    DEFF Research Database (Denmark)

    Carkaci, Derya; Nielsen, Xiaohui Chen; Fuursted, Kurt

    2017-01-01

    BACKGROUND: Aerococcus urinae and Aerococcus sanguinicola are relatively newcomers and emerging organisms in clinical and microbiological practice. Both species have worldwide been associated with urinary tract infections. More rarely cases of bacteremia/septicemia and infective endocarditis have...

  14. In vitro antagonistic growth effects of Lactobacillus fermentum and Lactobacillus salivarius and their fermentative broth on periodontal pathogens

    Directory of Open Access Journals (Sweden)

    Ling-Ju Chen

    2012-12-01

    Full Text Available As lactobacilli possess an antagonistic growth property, these bacteria may be beneficial as bioprotective agents for infection control. However, whether the antagonistic growth effects are attributed to the lactobacilli themselves or their fermentative broth remains unclear. The antagonistic growth effects of Lactobacillus salivarius and Lactobacillus fermentum as well as their fermentative broth were thus tested using both disc agar diffusion test and broth dilution method, and their effects on periodontal pathogens, including Streptococcus mutans, Streptococcus sanguis, and Porphyromonas gingivalisin vitro at different concentrations and for different time periods were also compared. Both Lactobacillus salivarius and Lactobacillus fermentum and their concentrated fermentative broth were shown to inhibit significantly the growth of Streptococcus mutans, Streptococcus sanguis, and Porphyromonas gingivalis, althoughdifferent inhibitory effects were observed for different pathogens. The higher the counts of lactobacilli and the higher the folds of concentrated fermentative broth, the stronger the inhibitory effects are observed. The inhibitory effect is demonstrated to be dose-dependent. Moreover, for the lactobacilli themselves, Lactobacillus fermentum showed stronger inhibitory effects than Lactobacillus salivarius. However, the fermentative broth of Lactobacillus fermentum showed weaker inhibitory effects than that of Lactobacillus salivarius. These data suggested that lactobacilli and their fermentative broth exhibit antagonistic growth activity, and consumption of probiotics or their broth containing lactobacilli may benefit oral health.

  15. A survey of methods used for antimicrobial susceptibility testing in veterinary diagnostic laboratories in the United States.

    Science.gov (United States)

    Dargatz, David A; Erdman, Matthew M; Harris, Beth

    2017-09-01

    Antimicrobial resistance is a serious threat to animal and human health worldwide, requiring a collaborative, holistic approach. The U.S. Government has developed a national strategy to address antimicrobial resistance, with one component being to monitor antimicrobial resistance in agricultural settings. We developed a survey to collect information about antimicrobial susceptibility testing (AST) from the veterinary diagnostic laboratory community in the United States, assessing current practices and technologies and determining how AST information is shared. Of the 132 surveys administered, 52 (39%) were returned. Overall, responding laboratories conducted susceptibility tests on 98,788 bacterial isolates in 2014, with Escherichia coli being the most common pathogen tested across all animal species. The 2 most common AST methods employed were the disk diffusion method (71%) and the Sensititre platform broth microdilution system (59%). Laboratories primarily used the Clinical Laboratory Standards Institute (CLSI) VET-01 standard (69%) and the automatically calculated interpretations provided by the commercial AST systems (61%) for interpreting their AST data. Only 22% of laboratories published AST data on a periodic basis, usually via annual reports published on the laboratory's website or through peer-reviewed journals for specific pathogens. Our results confirm that disk diffusion and broth microdilution remain the standard AST methods employed by U.S. veterinary diagnostic laboratories, and that CLSI standards are commonly used for interpreting AST results. This information will help determine the most efficient standardized methodology for future surveillance. Furthermore, the current infrastructure within laboratories, once harmonized, will help provide a mechanism for conducting national surveillance programs.

  16. Comparison of methods for antimicrobial susceptibility testing and MIC values for pleuromutilin drugs for Brachyspira hyodysenteriae isolated in Germany.

    Science.gov (United States)

    Rohde, Judith; Kessler, Martina; Baums, Christoph G; Amtsberg, Gunter

    2004-08-19

    In Germany treatment of swine dysentery is hampered by Brachyspira hyodysenteriae strains showing elevated MIC values to the few antibiotics licensed. Therefore, susceptibility testing of clinical isolates is an important service to the swine practitioner. This study compares the established agar dilution procedure for antimicrobial susceptibility testing of this fastidious anaerobe to the broth microdilution test newly developed [Anim. Health Res. 2 (2001) 59; Vet. Microbiol. 84 (2002) 123; J. Clin. Microbiol. 41 (2003) 2596]. A total of 221 isolates were examined twice with either test procedure using tiamulin and valnemulin as antibiotics. Both methods gave reproducible results, and the MIC values for the reference strains B. hyodysenteriae B204 and Staphylococcus aureus ATCC 29213 corresponded to previously published data. However, the results for individual strains differed significantly for both tests (P < 0.001) with MIC values being on average one dilution step lower in the broth dilution method. The 221 strains used for comparing test procedures were isolated between 1989 and 2001. An additional 102 strains isolated in 2002 were tested only with the broth dilution procedure. A significant rise in the average MIC value for both pleuromutilins could be demonstrated when comparing earlier isolates to those from 2000 to 2001 (P < 0.05), while in 2002 the average MIC significantly decreased when compared to the value in 2000 (P < 0.05). However, strains with MIC values for tiamulin as high as 8 microg/ml (broth dilution) could still be isolated.

  17. The risk of lead contamination in bone broth diets.

    Science.gov (United States)

    Monro, J A; Leon, R; Puri, B K

    2013-04-01

    The preparation and consumption of bone broth is being increasingly recommended to patients, for example as part of the gut and psychology syndrome (GAPS) diet for autism, attention-deficit hyperactivity disorder, dyslexia, dyspraxia, depression and schizophrenia, and as part of the paleolithic diet. However, bones are known to sequester the heavy metal lead, contamination with which is widespread throughout the modern environment. Such sequestered lead can then be mobilised from the bones. We therefore hypothesised that bone broth might carry a risk of being contaminated with lead. A small, blinded, controlled study of lead concentrations in three different types of organic chicken broth showed that such broths do indeed contain several times the lead concentration of the water with which the broth is made. In particular, broth made from skin and cartilage taken off the bone once the chicken had been cooked with the bones in situ, and chicken-bone broth, were both found to have markedly high lead concentrations, of 9.5 and 7.01 μg L(-1), respectively (compared with a control value for tap water treated in the same way of 0.89 μg L(-1)). In view of the dangers of lead consumption to the human body, we recommend that doctors and nutritionists take the risk of lead contamination into consideration when advising patients about bone broth diets. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Colistin MIC Variability by Method for Contemporary Clinical Isolates of Multidrug-Resistant Gram-Negative Bacilli

    Science.gov (United States)

    Hindler, Janet A.

    2013-01-01

    In vitro evaluation of colistin susceptibility is fraught with complications, due in part to the inherent cationic properties of colistin. In addition, no reference method has been defined against which to compare the results of colistin susceptibility testing. This study systematically evaluated the available methods for colistin MIC testing in two phases. In phase I, colistin MICs were determined in 107 fresh clinical isolates of multidrug-resistant (MDR) Gram-negative bacilli (GNB) by broth microdilution with polysorbate 80 (BMD-T), broth macrodilution (TDS), and the Etest. In phase II, 50 of these isolates, 10 of which were colistin resistant, were tested in parallel using BMD-T, TDS, agar dilution, broth microdilution without polysorbate 80 (BMD), and the TREK Gram-negative extra MIC format (GNXF) Sensititre. The Etest was also performed on these 50 isolates using Mueller-Hinton agar (MHA) from three different manufacturers. Colistin MIC results obtained from the five methods were compared to the MIC results obtained using BMD-T, the method that enables the highest nominal concentration of colistin in the test medium. Essential agreement ranged from 34% (BMD) to 83% (TDS), whereas categorical agreement was >90% for all methods except for BMD, which was 88%. Very major errors (VMEs) (i.e., false susceptibility) for the Etest were found in 47 to 53% of the resistant isolates, depending on the manufacturer of the MHA that was used. In contrast, VMEs were found for 10% (n = 1) of the resistant isolates by BMD and 0% of the isolates by the TDS, agar dilution, and Sensititre methods. Based on these data, we urge clinical laboratories to be aware of the variable results that can occur when using different methods for colistin MIC testing and, in particular, to use caution with the Etest. PMID:23486719

  19. Use of Mueller-Hinton broth and agar in the germ tube test.

    Science.gov (United States)

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

    2014-01-01

    Candida albicans is often isolated from clinical samples, thus its presumptive differentiation from other species of the same genus can be based on its ability to form the germ tube in human serum. Nevertheless, there are two other species that share this characteristic: C. dubliniensis and C. africana. The aim of this study was to compare four different substrates to perform the germ tube (GT) test. The Candida spp. isolates were identified using a manual system (135 C. albicans, 24 C. tropicalis and one C. dubliniensis). The germ tube test was performed with fresh, previously frozen serum and Mueller-Hinton (MH) broth and agar. GT was observed in 96% (130/136) of the isolates through the fresh serum technique, 94% (128/136) through previously frozen serum, 92% (125/136) in MH agar, and 90% (122/136) in MH broth. The sensitivity of each test was higher than 90%, with 100% specificity. Both the MH agar and broth were able to identify the true positives, and false positives were not found. However, some C. albicans isolates were not identified. MH agar and broth may be used in laboratory for the rapid presumptive identification of C. albicans, as an alternative method for germ tube test.

  20. Analysis of lard in meatball broth using Fourier transform infrared spectroscopy and chemometrics.

    Science.gov (United States)

    Kurniawati, Endah; Rohman, Abdul; Triyana, Kuwat

    2014-01-01

    Meatball is one of the favorite foods in Indonesia. For the economic reason (due to the price difference), the substitution of beef meat with pork can occur. In this study, FTIR spectroscopy in combination with chemometrics of partial least square (PLS) and principal component analysis (PCA) was used for analysis of pork fat (lard) in meatball broth. Lard in meatball broth was quantitatively determined at wavenumber region of 1018-1284 cm(-1). The coefficient of determination (R(2)) and root mean square error of calibration (RMSEC) values obtained were 0.9975 and 1.34% (v/v), respectively. Furthermore, the classification of lard and beef fat in meatball broth as well as in commercial samples was performed at wavenumber region of 1200-1000 cm(-1). The results showed that FTIR spectroscopy coupled with chemometrics can be used for quantitative analysis and classification of lard in meatball broth for Halal verification studies. The developed method is simple in operation, rapid and not involving extensive sample preparation. © 2013.

  1. USE OF MUELLER-HINTON BROTH AND AGAR IN THE GERM TUBE TEST

    Directory of Open Access Journals (Sweden)

    Antonella Souza Mattei

    2014-12-01

    Full Text Available Candida albicans is often isolated from clinical samples, thus its presumptive differentiation from other species of the same genus can be based on its ability to form the germ tube in human serum. Nevertheless, there are two other species that share this characteristic: C. dubliniensis and C. africana. The aim of this study was to compare four different substrates to perform the germ tube (GT test. The Candida spp. isolates were identified using a manual system (135 C. albicans, 24 C. tropicalis and one C. dubliniensis. The germ tube test was performed with fresh, previously frozen serum and Mueller-Hinton (MH broth and agar. GT was observed in 96% (130/136 of the isolates through the fresh serum technique, 94% (128/136 through previously frozen serum, 92% (125/136 in MH agar, and 90% (122/136 in MH broth. The sensitivity of each test was higher than 90%, with 100% specificity. Both the MH agar and broth were able to identify the true positives, and false positives were not found. However, some C. albicans isolates were not identified. MH agar and broth may be used in laboratory for the rapid presumptive identification of C. albicans, as an alternative method for germ tube test.

  2. Esterification synthesis of ethyl oleate in solvent-free system catalyzed by lipase membrane from fermentation broth.

    Science.gov (United States)

    Li, Wei-Na; Chen, Bi-Qiang; Tan, Tian-Wei

    2011-01-01

    In this study, the immobilized lipase was prepared by fabric membrane adsorption in fermentation broth. The lipase immobilization method in fermentation broth was optimized on broth activity units and pH adjustments. The viscose fermentation broth can be used with a certain percentage of dilution based on the original broth activity units. The fermentation broth can be processed directly without pH adjustment. In addition, the oleic acid ethyl ester production in solvent-free system catalyzed by the immobilized lipase was optimized. The molar ratio of ethanol to oil acid, the enzyme amount, the molecular amount, and the temperature were 1:1, 12% (w/w), 9% (w/w)(based the total amount of reaction mixture), and 30 °C, respectively. Finally, the optimal condition afforded at least 19 reuse numbers with esterification rate above 80% under stepwise addition of ethanol. Due to simple lipase immobilization preparation, acceptable esterification result during long-time batch reactions and lower cost; the whole process was suitable for industrial ethyl oleate production.

  3. [A multi-pathogen selective enrichment broth for simultaneous growth of Salmonella enteritidis, Staphylococcus aureus, and Listeria monocytogenes].

    Science.gov (United States)

    Liu, Yuanyuan; Xiao, Xinglong; Yu, Yigang; Chen, Gu; Li, Xiaofeng; Tang, Yuqian; Wu, Hui

    2009-10-01

    A selective enrichment broth (SSL) was formulated to allow simultaneous growth of Salmonella enteritidis, Staphylococcus aureus, and Listeria monocytogens. Suitable additive agents were selected by single factor experiment, the enrichment effect of the broth for the three pathogens were evaluated by conventional detection method and real-time PCR. A selective enrichment broth, SSL, was obtained by adding the selective agents, including nalidixic acid, lithium chloride, and potassium tellurite, in the basic broth, and sodium pyruvate and mannitol as the supplemented elements. Recovery of three target pathogens in SSL was obtained within 24 h of incubation at 37 degrees C, yielding cell dnesities of 10(7) - 10(8) CFU/mL. Meanwhile, SSL broth effectively inhibited the growth of non-target organisms. 710 samples were detected by SSL with real-time PCR, and there is no error report. SSL is demonstrated to be a promising new multiplex selective enrichment broth for simultaneous detection of the three most prominent foodborn pathogens by multipathogen detection on a single assay platform.

  4. Rapid determination of lovastatin in the fermentation broth of Aspergillus terreus using dual-wavelength UV spectrophotometry.

    Science.gov (United States)

    Li, Shi-Weng; Song, Hong-Ping; Leng, Yan

    2014-01-01

    Lovastatin, a hypocholesterolemic drug, is produced by submerged fermentation of Aspergillus terreus Thom (Trichocomaceae). High performance liquid chromatography is usually used to determine lovastatin in samples of the fermentation broth. However, this method is inconvenient and costly, especially in the context of high-throughput sample analysis. A direct and simple dual-wavelength ultraviolet spectrophotometric method for quantifying lovastatin in the fermentation broth of A. terreus was developed. A. terreus Z15-7 was used for all experiments. The liquid fermentation was conducted at 30 °C in a rotary shaker at 150 rpm for 15 d. Silica gel and neutral alumina column chromatography were used for the separation and purification of lovastatin from the fermentation broth. The limits of detection of lovastatin were 0.320 μg/ml in the lovastatin standard solution and 0.490 μg/ml in the fermentation broth sample and the limits of quantification of lovastatin were 1.265 μg/ml in the lovastatin standard solution and 3.955 μg/ml in the fermentation broth sample. The amounts of lovastatin in the fermentation broth ranged from 876.614 to 911.967 μg/ml, with relative standard deviations from 1.203 to 1.709%. The mean recoveries of lovastatin using silica gel and neutral alumina column chromatography were 84.2 ± 0.82 and 87.2 ± 0.21%, respectively. Dual-wavelength UV spectrophotometry is a rapid, sensitive, accurate, and convenient method for quantifying lovastatin in fermentation broth. Neutral alumina column chromatography is more efficient than silica gel column chromatography for the purification and determination lovastatin using the developed dual-wavelength UV spectrophotometry method.

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

    Directory of Open Access Journals (Sweden)

    M.J. Najafzadeh

    2009-08-01

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

  6. Superparamagnetic poly(methyl methacrylate) beads for nattokinase purification from fermentation broth.

    Science.gov (United States)

    Yang, Chengli; Xing, Jianmin; Guan, Yueping; Liu, Huizhou

    2006-09-01

    An effective method for purification of nattokinase from fermentation broth using magnetic poly(methyl methacrylate) (PMMA) beads immobilized with p-aminobenzamidine was proposed in this study. Firstly, magnetic PMMA beads with a narrow size distribution were prepared by spraying suspension polymerization. Then, they were highly functionalized via transesterification reaction with polyethylene glycol. The surface hydroxyl-modified magnetic beads obtained were further modified with chloroethylamine to transfer the surface amino-modified magnetic functional beads. The morphology and surface functionality of the magnetic beads were examined by scanning electron microscopy and Fourier transform infrared. An affinity ligand, p-aminobenzamidine was covalently immobilized to the amino-modified magnetic beads by the glutaraldehyde method for nattokinase purification directly from the fermentation broth. The purification factor and the recovery of the enzyme activity were found to be 8.7 and 85%, respectively. The purification of nattokinase from fermentation broth by magnetic beads only took 40 min, which shows a very fast purification of nattokinase compared to traditional purification methods.

  7. Antimicrobial Susceptibilities of Abiotrophia defectiva, Granulicatella adiacens, and Granulicatella elegans

    National Research Council Canada - National Science Library

    Alberti, Michael O; Hindler, Janet A; Humphries, Romney M

    2016-01-01

    .... Antimicrobial susceptibility testing (AST) was performed for 14 antimicrobials using the broth microdilution MIC method described in the Clinical and Laboratory Standards Institute (CLSI) M45 guideline...

  8. Molecular detection of Brucella spp. from broth culture of clinical ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... PCR was employed to detect Brucella spp. from broth cultures of clinical samples using a group ... studies, thus classifying Brucella as a monospecific ..... Bricker BJ, Halling SM (1995). Enhancement of the Brucella AMOS. PCR Assay for Differentiation of Brucella abortus vaccine strains S19 and RB51.

  9. Molecular detection of Brucella spp. from broth culture of clinical ...

    African Journals Online (AJOL)

    PCR was employed to detect Brucella spp. from broth cultures of clinical samples using a group specific primer based on IS6501 sequence. The sensitivity and specificity of this assay was confirmed by Southern hybridization analysis using a digoxigenin-labeled DNA probe while reproducibility of the analysis was ...

  10. Recovery of butanol from fermentation broth by pervaporation

    Science.gov (United States)

    Butanol can be produced by fermentation from corn, molasses or lignocellulosic biomass for use as a chemical or superior biofuel. However, butanol’s production is hampered by its toxicity to the microbial culture that produces it. In fermentation broths, final butanol concentrations typically range ...

  11. SEL, a selective enrichment broth for simultaneous growth of Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes.

    Science.gov (United States)

    Kim, Hyochin; Bhunia, Arun K

    2008-08-01

    to be a promising new multiplex selective enrichment broth for the detection of the three most prominent food-borne pathogens by antibody- or nucleic acid-based methods.

  12. Modeling of mixing in stirred bioreactors 4. mixing time for aerated bacteria, yeasts and fungus broths

    Directory of Open Access Journals (Sweden)

    Cascaval Dan

    2004-01-01

    Full Text Available The mixing time for bioreactors depends mainly on the rheoiogicai properties of the broths, the biomass concentration and morphology, mixing system characteristics and fermentation conditions. For quantifying the influence of these factors on the mixing efficiency for stirred bioreactors, aerated broths of bacteria (P. shermanii, yeasts (S. cerevisiae and fungi (P. chrysogenum, free mycelia and mycelial aggregates of different concentrations have been investigated using a laboratory bioreactor with a double turbine impeller. The experimental data indicated that the influence of the rotation speed, aeration rate and stirrer positions on the mixing intensity strongly differ from one system to another and must be correlated with the microorganism characteristics, namely: the biomass concentration and morphology. Moreover, compared with non-aerated broths, variations of the mixing time with the considered parameters are very different, due to the complex flow mechanism of gas-liquid dispersions. By means of the experimental data and using a multiregression analysis method some mathematical correlations for the mixing time of the general form: tm = a1*Cx2+a2*Cx+a3*IgVa+a4-N2+a5-N+a6/a7*L2+a8*L+a9 were established. The proposed equations offer good agreement with the experiments, the average deviation being ±6.7% - ±9.4 and are adequate for the flow regime Re < 25,000.

  13. Sugaring-out extraction of acetoin from fermentation broth by coupling with fermentation.

    Science.gov (United States)

    Dai, Jian-Ying; Ma, Lin-Hui; Wang, Zhuang-Fei; Guan, Wen-Tian; Xiu, Zhi-Long

    2017-03-01

    Acetoin is a natural flavor and an important bio-based chemical which could be separated from fermentation broth by solvent extraction, salting-out extraction or recovered in the form of derivatives. In this work, a novel method named as sugaring-out extraction coupled with fermentation was tried in the acetoin production by Bacillus subtilis DL01. The effects of six solvents on bacterial growth and the distribution of acetoin and glucose in different solvent-glucose systems were explored. The operation parameters such as standing time, glucose concentration, and volume ratio of ethyl acetate to fermentation broth were determined. In a system composed of fermentation broth, glucose (100%, m/v) and two-fold volume of ethyl acetate, nearly 100% glucose was distributed into bottom phase, and 61.2% acetoin into top phase without coloring matters and organic acids. The top phase was treated by vacuum distillation to remove solvent and purify acetoin, while the bottom phase was used as carbon source to produce acetoin in the next batch of fermentation.

  14. Bacteriostasis testing on allograft tissue inoculated in Wilkins-Chalgren broth.

    Science.gov (United States)

    Saegeman, V; Ectors, N; Lismont, D; Verduyckt, B; Verhaegen, J

    2008-11-01

    Tissue banks culture tissue specimens to confirm the absence of viable micro-organisms after decontamination with antibiotics. It is possible that antibiotic residues attached to decontaminated tissue are introduced into enrichment culture media. These could have an inhibitory effect on the culture results and generate false-negative results. Our aim was to detect bacteriostasis in Wilkins-Chalgren broth inoculated with bone and tendon remnants. These remnants had been soaked in a solution containing gentamicin as part of the tissue-processing procedure. We used the United States Pharmacopeia method for bacteriostasis testing with gentamicin-susceptible Pseudomonas aeruginosa American Type Culture Collection (ATCC) 15442, Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633 as test strains, and gentamicin-resistant Candida albicans ATCC 90029 as control. The residual gentamicin concentration in the broths was determined and gentamicin-soaked tissue was placed on Mueller-Hinton agar inoculated with a staphylococcal suspension. Bacteriostasis was present in 53-75% of the reference test strains. Tendon remnants had a significantly higher rate of bacteriostasis (85%) than bone remnants (28%). Broths inoculated with tendon remnants had the highest residual gentamicin concentrations.

  15. Green synthesis of gold nanoparticles using Cinnamomum zeylanicum leaf broth

    Science.gov (United States)

    Smitha, S. L.; Philip, Daizy; Gopchandran, K. G.

    2009-10-01

    Development of biologically inspired experimental processes for the synthesis of nanoparticles is an important branch of nanotechnology. The synthesis of gold nanoparticles using Cinnamomum zeylanicum leaf broth as the reducing agent is reported. The morphology of the particles formed consists of a mixture of gold nanoprisms and spheres with fcc (1 1 1) structure of gold. At lower concentrations of the extract, formation of prism shaped Au particles dominates, while at higher concentrations almost spherical particles alone are observed. Good crystallinity of the nanoparticles with fcc phase is evident from XRD patterns, clear lattice fringes in the high resolution TEM image and bright circular rings in the SAED pattern. Au nanoparticles grown are observed to be photoluminescent and the intensity of photoemission is found to increase with increase in leaf broth concentration. The ability to modulate the shape of nanoparticles as observed in this study for gold nanoparticles opens up the exciting possibility of developing further synthetic routes employing ecofriendly sources.

  16. Development of a Novel Listeria Enrichment Broth for the Isolation of Pathogenic Listeria.

    Science.gov (United States)

    Liu, Dongxin; Wang, Yan; Wang, Yi; Zhang, Lu; Luo, Lijuan; Liu, Kai; Ye, Changyun

    2017-10-01

    Listeriosis, the disease caused by pathogenic Listeria species, can present severe symptoms in susceptible people. The goal of this study was to develop a novel enrichment broth, Listeria allose enrichment broth (LAEB), to improve isolation of Listeria monocytogenes and Listeria ivanovii from samples through incorporating a specific carbohydrate and reducing inhibitor concentrations. Other coexisting bacteria, particularly Listeria innocua, can interfere with the isolation of pathogenic Listeria in such ways as overgrowth of L. innocua and the generation of inhibitory metabolites. The incorporation of allose into the novel LAEB was effective for slowing the growth of L. innocua and other nontarget microorganisms. We determined that 35°C and pH 7.0 under aerobic conditions are optimal for Listeria growth in this medium. The novelty of the use of LAEB is the single enrichment procedure at 35°C for 24 h, obviating the need for a secondary enrichment medium. In 50 simulated samples, the sensitivity of the LAEB method (86%) was higher than that of the International Organization for Standardization (EN ISO) method (70%). In 142 naturally contaminated samples tested, the isolation rate for pathogenic Listeria with the LAEB method was 26.0% (37 of 142 samples), which was significantly higher than the 17.6% (25 of 142 samples) for the EN ISO method. Higher isolation rates and a quicker and easier protocol make the novel LAEB method an appropriate alternative for the isolation of pathogenic Listeria.

  17. Pre-treatment step with Leuconostoc mesenteroides or L. pseudomesenteroides strains removes furfural from Zymomonas mobilis ethanolic fermentation broth.

    Science.gov (United States)

    Hunter, William J; Manter, Daniel K

    2014-10-01

    Furfural is an inhibitor of growth and ethanol production by Zymomonas mobilis. This study used a naturally occurring (not GMO) biological pre-treatment to reduce that amount of furfural in a model fermentation broth. Pre-treatment involved inoculating and incubating the fermentation broth with strains of Leuconostoc mesenteroides or Leuconostoc pseudomesenteroides. The Leuconostoc strains converted furfural to furfuryl alcohol without consuming large amounts of dextrose in the process. Coupling this pre-treatment to ethanolic fermentation reduced furfural in the broth and improved growth, dextrose uptake and ethanol formation. Pre-treatment permitted ethanol formation in the presence of 5.2 g L(-1) furfural, which was otherwise inhibitive. The pre-treatment and presence of the Leuconostoc strains in the fermentation broth did not interfere with Z. mobilis ethanolic fermentation or the amounts of ethanol produced. The method suggests a possible technique for reducing the effect that furfural has on the production of ethanol for use as a biofuel. Published by Elsevier Ltd.

  18. Removal of heavy metals from polluted soil using the citric acid fermentation broth: a promising washing agent.

    Science.gov (United States)

    Zhang, Hongjiao; Gao, Yuntao; Xiong, Huabin

    2017-04-01

    The citric acid fermentation broth was prepared and it was employed to washing remediation of heavy metal-polluted soil. A well-defined washing effect was obtained, the removal percentages using citric acid fermentation broth are that 48.2% for Pb, 30.6% for Cu, 43.7% for Cr, and 58.4% for Cd and higher than that using citric acid solution. The kinetics of heavy metals desorption can be described by the double constant equation and Elovich equation and is a heterogeneous diffusion process. The speciation analysis shows that the citric acid fermentation broth can effectively reduce bioavailability and environmental risk of heavy metals. Spectroscopy characteristics analysis suggests that the washing method has only a small effect on the mineral composition and does not destroy the framework of soil system. Therefore, the citric acid fermentation broth is a promising washing agent and possesses a potential practical application value in the field of remediation of soils with a good washing performance.

  19. Fusarium keratitis in South India: causative agents, their antifungal susceptibilities and a rapid identification method for the Fusarium solani species complex.

    Science.gov (United States)

    Homa, Mónika; Shobana, Coimbatore S; Singh, Yendrembam R B; Manikandan, Palanisamy; Selvam, Kanesan P; Kredics, László; Narendran, Venkatapathy; Vágvölgyi, Csaba; Galgóczy, László

    2013-09-01

    Seventy Fusarium isolates derived from human keratomycosis were identified based on partial sequences of the β-tubulin (β-TUB) and translation elongation factor 1α (EF-1α) genes. Most of the isolates were confirmed as members of the F. solani species complex (75.71%), followed by the F. dimerum species complex (8.57%), the F. fujikuroi species complex (8.57%), the F. oxysporum species complex (4.29%) and the F. incarnatum-equiseti species complex (2.86%). A combined phylogenetic tree was estimated including all the 70 isolates. Isolates belonging to different species complexes formed separate clades. In this study, we also report the first isolation of F. napiforme from human keratomycosis. A new method based on a specific EcoRI restriction site in the EF-1α gene was developed for the rapid identification of F. solani. In vitro antifungal susceptibilities of the isolates to seven antifungals were determined by broth microdilution method. Terbinafine, natamycin and amphotericin B proved to be the most effective drugs, followed by voriconazole. The minimal inhibitory concentrations of clotrimazole, econazole and itraconazole were generally high (≥64 μg ml(-1) ). The interactions between the two most effective antifungals (natamycin and terbinafine) were determined by checkerboard microdilution method. Synergism (71.8%) or no interaction (28.2%) was revealed between the two compounds. © 2013 Blackwell Verlag GmbH.

  20. Rapid determination of hyaluronic acid concentration in fermentation broth with near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Qin Dong

    2014-11-01

    Full Text Available Hyaluronic acid (HA concentration is an important parameter in fermentation process. Currently, carbazole assay is widely used for HA content determination in routine analysis. However, this method is time-consuming, environment polluting and has the risk of microbial contamination, as well as the results lag behind fermentation process. This paper attempted the feasibility to predict the concentration of HA in fermentation broth by using near infrared (NIR spectroscopy in transmission mode. In this work, a total of 56 samples of fermentation broth from 7 batches were analyzed, which contained HA in the range of 2.35–9.69 g/L. Different data preprocessing methods were applied to construct calibration models. The final optimal model was obtained with first derivative using Savitzky–Golay smoothing (9 points window, second-order polynomial and partial least squares (PLS regression with leave-one-block-out cross validation. The correlation coefficient and Root Mean Square Error of prediction set is 0.98 and 0.43 g/L, respectively, which show the possibility of NIR as a rapid method for microanalysis and to be a promising tool for a rapid assay in HA fermentation.

  1. BetalasEN: microdilution panel for identifying beta-lactamases present in isolates of Enterobacteriaceae.

    Science.gov (United States)

    Sanders, Christine C; Ehrhardt, Anton F; Moland, Ellen Smith; Thomson, Kenneth S; Zimmer, Barbara; Roe, Darcie E

    2002-01-01

    A dried investigational use-only microdilution panel named betalasEN (a short named derived from the panel's purpose, to identify beta-lactamases in Enterobacteriaceae) containing 10 beta-lactam drugs with and without beta-lactamase inhibitors was developed to identify beta-lactamases among clinical isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter koseri, Citrobacter freundii group, Enterobacter spp., and Serratia marcescens. The MICs obtained with a collection of 383 organisms containing well-characterized beta-lactamases were used to develop numeric codes and logic pathways for computerized analysis of results. The resultant logic pathways and betalasEN panel were then used to test and identify beta-lactamases among 885 isolates of Enterobacteriaceae recovered in cultures obtained at six different hospital laboratories across the United States. beta-Lactamases present in 801 (90.5%) of the 885 isolates were identified by betalasEN by using the existing logic pathways and codes or after minor modifications were made to the existing codes. The 84 strains that gave codes that betalasEN could not identify were collected, reidentified, and retested by using betalasEN. Three strains had been misidentified, 54 strains gave different codes upon repeat testing that could be identified by betalasEN, and 27 strains repeated new codes. The beta-lactamases in these strains were identified, and the new codes were added to the betalasEN logic pathways. These results indicate that betalasEN can identify clinically important beta-lactamases among most isolates of Enterobacteriaceae. The results also show that good quality control and attention to proper performance of the tests are essential to the correct performance of betalasEN.

  2. Differentiation between Candida albicans and Candida dubliniensis using hypertonic Sabouraud broth and tobacco agar

    Directory of Open Access Journals (Sweden)

    Fabíola Silveira-Gomes

    2011-08-01

    Full Text Available INTRODUCTION: Opportunistic fungal infections in immunocompromised hosts are caused by Candida species, and the majority of such infections are due to Candida albicans. However, the emerging pathogen Candida dubliniensis demonstrates several phenotypic characteristics in common with C. albicans, such as production of germ tubes and chlamydospores, calling attention to the development of stable resistance to fluconazole in vitro. The aim of this study was to evaluate the performance of biochemistry identification in the differentiating between C. albicans and C. dubliniensis, by phenotyping of yeast identified as C. albicans. METHODS: Seventy-nine isolates identified as C. albicans by the API system ID 32C were grown on Sabouraud dextrose agar at 30°C for 24-48h and then inoculated on hypertonic Sabouraud broth and tobacco agar. RESULTS: Our results showed that 17 (21.5% isolates were growth-inhibited on hypertonic Sabouraud broth, a phenotypic trait inconsistent with C. albicans in this medium. However, the results observed on tobacco agar showed that only 9 (11.4% of the growth-inhibited isolates produced characteristic colonies of C. dubliniensis (rough colonies, yellowish-brown with abundant fragments of hyphae and chlamydospores. CONCLUSIONS: The results suggest that this method is a simple tool for screening C. albicans and non-albicans yeast and for verification of automated identification.

  3. Evaluation of four selective agars and two enrichment broths in screening for methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Böcher, S; Smyth, R; Kahlmeter, G; Kerremans, J; Vos, M C; Skov, R

    2008-09-01

    To evaluate methicillin-resistant Staphylococcus aureus detection, we tested in vitro four selective agars and two enrichment broths apart and in combination. Tryptone soya broth with salt, aztreonam, and cefoxitin appeared to be the most sensitive medium. This broth was superior to a phenol red mannitol broth with aztreonam and ceftizoxime.

  4. Studies of polypropylene membrane fouling during microfiltration of broth with Citrobacter freundii bacteria

    Directory of Open Access Journals (Sweden)

    Gryta Marek

    2015-12-01

    Full Text Available In this work a fouling study of polypropylene membranes used for microfiltration of glycerol solutions fermented by Citrobacter freundii bacteria was presented. The permeate free of C. freundii bacteria and having a turbidity in the range of 0.72–1.46 NTU was obtained. However, the initial permeate flux (100–110 L/m2h at 30 kPa of transmembrane pressure was decreased 3–5 fold during 2–3 h of process duration. The performed scanning electron microscope observations confirmed that the filtered bacteria and suspensions present in the broth formed a cake layer on the membrane surface. A method of periodical module rinsing was used for restriction of the fouling influence on a flux decline. Rinsing with water removed most of the bacteria from the membrane surface, but did not permit to restore the initial permeate flux. It was confirmed that the irreversible fouling was dominated during broth filtration. The formed deposit was removed using a 1 wt% solution of sodium hydroxide as a rinsing solution.

  5. Two-stage electrodialytic concentration of glyceric acid from fermentation broth.

    Science.gov (United States)

    Habe, Hiroshi; Shimada, Yuko; Fukuoka, Tokuma; Kitamoto, Dai; Itagaki, Masayuki; Watanabe, Kunihiko; Yanagishita, Hiroshi; Sakaki, Keiji

    2010-12-01

    The aim of this research was the application of a two-stage electrodialysis (ED) method for glyceric acid (GA) recovery from fermentation broth. First, by desalting ED, glycerate solutions (counterpart is Na+) were concentrated using ion-exchange membranes, and the glycerate recovery and energy consumption became more efficient with increasing the initial glycerate concentration (30 to 130 g/l). Second, by water-splitting ED, the concentrated glycerate was electroconverted to GA using bipolar membranes. Using a culture broth of Acetobacter tropicalis containing 68.6 g/l of D-glycerate, a final D-GA concentration of 116 g/l was obtained following the two-stage ED process. The total energy consumption for the D-glycerate concentration and its electroconversion to D-GA was approximately 0.92 kWh per 1 kg of D-GA. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  6. Differentiation between Candida albicans and Candida dubliniensis using hypertonic Sabouraud broth and tobacco agar.

    Science.gov (United States)

    Silveira-Gomes, Fabíola; Sarmento, Dayse Nogueira; Espírito-Santo, Elaine Patrícia Tavares do; Souza, Nádia de Oliveira; Pinto, Thifany Mendes; Marques-da-Silva, Silvia Helena

    2011-01-01

    Opportunistic fungal infections in immunocompromised hosts are caused by Candida species, and the majority of such infections are due to Candida albicans. However, the emerging pathogen Candida dubliniensis demonstrates several phenotypic characteristics in common with C. albicans, such as production of germ tubes and chlamydospores, calling attention to the development of stable resistance to fluconazole in vitro. The aim of this study was to evaluate the performance of biochemistry identification in the differentiating between C. albicans and C. dubliniensis, by phenotyping of yeast identified as C. albicans. Seventy-nine isolates identified as C. albicans by the API system ID 32C were grown on Sabouraud dextrose agar at 30°C for 24-48h and then inoculated on hypertonic Sabouraud broth and tobacco agar. Our results showed that 17 (21.5%) isolates were growth-inhibited on hypertonic Sabouraud broth, a phenotypic trait inconsistent with C. albicans in this medium. However, the results observed on tobacco agar showed that only 9 (11.4%) of the growth-inhibited isolates produced characteristic colonies of C. dubliniensis (rough colonies, yellowish-brown with abundant fragments of hyphae and chlamydospores). The results suggest that this method is a simple tool for screening C. albicans and non-albicans yeast and for verification of automated identification.

  7. Recovery of Xanthan Gum from Palm Oil-Based Fermentation Broth by Diafiltration with Flat Polysulfone Microfiltration (MF) Membrane

    OpenAIRE

    Sufian So’aib, M.; Krishnan, J.; Veluri, M. V. P. S.

    2014-01-01

    Xanthan gum recovery from palm oil-based broth by diafiltration was carried out using flat microfiltration (MF) membrane. Optimization of process parameters such as transmembrane pressure (TMP), crossflow velocity (CFV), ionic strength (IS) and diafiltration factor (DF) was performed by Taguchi method using signal-to-noise (S/N) ratio of larger-the-better criterion yielding the following optimum conditions: level 1, level 2, level 3, and level 2, respectively, corresponding to Xanthan recover...

  8. Antimicrobial activity of broth fermented with kefir grains.

    Science.gov (United States)

    Silva, Karoline R; Rodrigues, Sheila A; Filho, Lauro Xavier; Lima, Alvaro S

    2009-02-01

    Kefir grains originate from the Caucasus region and are used for preparing beverages using sugar solution, milk, and fruit juice. As long as they are formed by a microbial consortium useful in the intestine, the produced drinks can be called probiotics. The aim of this study was to determine the antimicrobial activity during kefir fermentation in sugar broth. Fermentations with three kinds of carbohydrates (molasses, demerara sugar, and brown sugar) as carbon source were carried out. Brown sugar promoted the greatest antimicrobial activities, producing inhibition halos corresponding to 35, 14, 12, 14, and 14 mm for Candida albicans, Salmonella typhi, Shigella sonnei, Staphylococcus aureus, and Escherichia coli, respectively. Different carbon source concentrations and the time of fermentation influenced the size of the inhibition halos of the pathogenic microorganisms.

  9. Recovery and purification of polysaccharides from microbial broth.

    Science.gov (United States)

    Johns, M R; Noor, E

    1991-04-01

    Current industrial practice to recover extracellular microbial polysaccharides from the broth usually requires dilution to permit cell removal followed by precipitation, typically using alcohol. This paper presents a discussion on the solvent precipitation of xanthan and the results of research performed to investigate the behaviour of xanthan solutions during membrane processing using a microporous membrane. Using crossflow microfiltration, flux rates of up to 120 L/m2h were achieved for pure xanthan solutions, with complete rejection of the polysaccharide by the membrane. The thin film model underpredicted flux for xanthan solutions. In fact, flux was independent of xanthan concentration up to 20-25 g/L, and strongly dependent on crossflow velocity. Considerable benefits in terms of purification and reduced solvent requirements can be obtained by the use of an intermediate crossflow microfiltration step during xanthan recovery.

  10. Enhancement of oxygen mass transfer in stirred bioreactors using oxygen-vectors 2. Propionibacterium shermanii broths.

    Science.gov (United States)

    Galaction, Anca-Irina; Cascaval, Dan; Turnea, Marius; Folescu, Elena

    2005-07-01

    The previous works on simulated broths are continued and developed for Propionibacterium shermanii broths. The obtained results indicated the considerable increase of kLa in presence of n-dodecane as oxygen-vector and the existence of a certain value of hydrocarbon concentration that corresponds to the maximum mass transfer rate of oxygen. The magnitude of the positive effect of the oxygen-vector strongly depends on operational conditions of the bioreactor, on broth characteristics and on P. shermanii concentration.

  11. A comparison of tetrathionate broth and Rappaport's medium as enrichment media for Salmonella.

    Science.gov (United States)

    Nielsen, B B; Grunnet, K

    1977-03-01

    Tetrathionate broth (Müller-Kauffmann) and Rappaport's medium were compared in isolating Salmonella from meat- and bone-meal, receiving waters, sewage, and sludge. The results (Table I) show no difference in isolations from meat- and bone-meal, receiving waters, or sewage, while in studying sludge isolations were significantly less frequent from Rappaport's medium than from tetrathionate broth. The Salmonella positive plates, however, were easier to read when inoculated from Rappaport's medium than from tetrathionate broth.

  12. Comparison of DNA-extraction methods and Selective Enrichment broths on the detection of Salmonella Typhimurium in swine feces by polymerase chain reaction (PCR Comparação entre métodos de extração de DNA e caldos de enriquecimento seletivo na detecção de Salmonella Typhimurium em fezes de suínos pela reação em cadeia da polimerase (PCR

    Directory of Open Access Journals (Sweden)

    Carla Roberta Freschi

    2005-12-01

    Full Text Available The aim of this study was to compare different DNA-extraction methods and selective enrichment broths for their effectiveness to detect Salmonella Typhimurium in artificially inoculated swine feces samples (100 CFU/g by polymerase chain reaction. After enrichment in Rappaport-Vassiliadis, selenite cystine or Müller-Kauffmann tetrathionate, aliquots were used for DNA extraction by three different methods: boiling-centrifugation, phenol-chloroform and salting-out. Aliquots of extracted DNA were then used as template in PCR. The selective enrichment broths had no effect on the efficiency of PCR when boiling-centrifugation and salting-out were used. On the other hand, phenol-chloroform was superior (PO objetivo do presente estudo foi comparar diferentes técnicas de extração de DNA, realizadas a partir de três diferentes caldos de enriquecimento seletivo, na sua eficiência em detectar Salmonella Typhimurium em amostras de fezes suínas artificialmente inoculadas (100 UFC/g, pela técnica de reação em cadeia da polimerase (PCR. Após enriquecimento em Rappaport-Vassiliadis, selenito-cistina e tetrationato Müller-Kauffmann, alíquotas destes caldos foram utilizadas para extração do DNA, empregando três métodos diferentes, (a fervura-centrifugação, (b fenol-clorofórmio e (c precipitação por sal. A eficiência dos métodos de extração de DNA por fervura-centrifugação e precipitação por sal foi a mesma, independentemente do caldo de enriquecimento seletivo utilizado. O caldo Rappaport-Vassiliadis apresentou maior eficiência (P<0,05 quando foi empregada a extração de DNA pelo método fenol-clorofórmio. Considerados os parâmetros custo e eficiência, os resultados do estudo indicaram que a partir de amostras fecais suínas a utilização do caldo tetrationato Müller-Kauffmann combinado a técnica de extração do DNA por fervura-centrifugação devam representar a melhor opção, relativamente às demais técnicas testadas.

  13. Effects of three major amino acids found in Japanese broth on glucose metabolism and gastric emptying.

    Science.gov (United States)

    Mano, Fumika; Ikeda, Kaori; Joo, Erina; Yamane, Shunsuke; Harada, Norio; Inagaki, Nobuya

    2017-08-10

    To our knowledge, the effect of the broth of dried kelp and dried bonito, dashi, on glucose metabolism and digestion has rarely been studied. Based on the component analysis of three actual broths served in traditional restaurants, a chemically synthesized broth with three free amino acids (histidine, glutamate, aspartate) and salt was prepared to investigate their effect on glucose metabolism, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide 1 (GLP-1) secretion, and digestion. In study 1, seven healthy individuals were enrolled in a four-period crossover study. Participants drank or ate hot water, synthesized broth, hot water with rice, and synthesized broth with rice. Plasma glucose, serum insulin, plasma glucagon, plasma GIP, and plasma GLP-1 were measured at baseline and after ingestion. In study 2, 6 of the 7 individuals ingested rice steamed with (13)C-labeled sodium acetate with hot water or synthesized broth to estimate gastric emptying by the (13)C-labeled acetate breath test in a two-period crossover trial. Ingesting water or synthesized broth alone elicited no change in plasma glucose or serum insulin levels. Ingesting synthesized broth with rice resulted in a rapid rise in plasma glucose and GLP-1 (P = 0.01 and 0.02, respectively) in an early postprandial phase compared with that by ingesting water with rice, but the area under the curve of those showed no significant differences. Ingesting synthesized broth with rice resulted in a significantly higher gastric emptying coefficient than that after rice with water (P = 0.03). Three amino acids and sodium chloride corresponding to those found in actual broth promoted gastric emptying and led to a rapid response of plasma glucose. Our findings suggest that ingestion of the broth of dried kelp and dried bonito may improve gastric motility. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. An integrated platform for gas-diffusion separation and electrochemical determination of ethanol on fermentation broths

    Energy Technology Data Exchange (ETDEWEB)

    Giordano, Gabriela Furlan [Microfabrication Laboratory, Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP 13083-970 (Brazil); Department of Analytical Chemistry, Institute of Chemistry – UNICAMP, Campinas, SP 13083-970 (Brazil); National Institute of Science and Technology of Bioanalytics, Institute of Chemistry – UNICAMP, Campinas, SP 13083-970 (Brazil); Vieira, Luis Carlos Silveira; Gobbi, Angelo Luiz [Microfabrication Laboratory, Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP 13083-970 (Brazil); Lima, Renato Sousa [Microfabrication Laboratory, Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP 13083-970 (Brazil); Department of Analytical Chemistry, Institute of Chemistry – UNICAMP, Campinas, SP 13083-970 (Brazil); National Institute of Science and Technology of Bioanalytics, Institute of Chemistry – UNICAMP, Campinas, SP 13083-970 (Brazil); Kubota, Lauro Tatsuo, E-mail: kubota@iqm.unicamp.br [Department of Analytical Chemistry, Institute of Chemistry – UNICAMP, Campinas, SP 13083-970 (Brazil); National Institute of Science and Technology of Bioanalytics, Institute of Chemistry – UNICAMP, Campinas, SP 13083-970 (Brazil)

    2015-05-22

    Highlights: • Integrated platform was developed to determine ethanol in fermentation broths. • The designed system integrates gas diffusion separation with voltammetric detection. • Detector relied on Ni(OH){sub 2}-modified electrode stabilized by Co{sup 2+} and Cd{sup 2+} insertion. • Separation was made by PTFE membrane separating sample from electrolyte (receptor). • Despite the sample complexity, accurate tests were achieved by direct interpolation. - Abstract: An integrated platform was developed for point-of-use determination of ethanol in sugar cane fermentation broths. Such analysis is important because ethanol reduces its fuel production efficiency by altering the alcoholic fermentation step when in excess. The custom-designed platform integrates gas diffusion separation with voltammetric detection in a single analysis module. The detector relied on a Ni(OH){sub 2}-modified electrode. It was stabilized by uniformly depositing cobalt and cadmium hydroxides as shown by XPS measurements. Such tests were in accordance with the hypothesis related to stabilization of the Ni(OH){sub 2} structure by insertion of Co{sup 2+} and Cd{sup 2+} ions in this structure. The separation step, in turn, was based on a hydrophobic PTFE membrane, which separates the sample from receptor solution (electrolyte) where the electrodes were placed. Parameters of limit of detection and analytical sensitivity were estimated to be 0.2% v/v and 2.90 μA % (v/v){sup −1}, respectively. Samples of fermentation broth were analyzed by both standard addition method and direct interpolation in saline medium based-analytical curve. In this case, the saline solution exhibited ionic strength similar to those of the samples intended to surpass the tonometry colligative effect of the samples over analyte concentration data by attributing the reduction in quantity of diffused ethanol vapor majorly to the electrolyte. The approach of analytical curve provided rapid, simple and accurate

  15. Multivariate models for prediction of rheological characteristics of filamentous fermentation broth from the size distribution

    DEFF Research Database (Denmark)

    Petersen, Nanna; Stocks, S.; Gernaey, Krist

    2008-01-01

    (y)), and consistency index (K), could be made from the size distributions, biomass concentration, and process information. This provides a predictive method with a high predictive power for the rheology of fermentation broth, and with the advantages over previous models that tau(y) and K can be predicted as well as mu(app...... in filamentous fermentations. It was therefore chosen to fix this parameter to the average value thereby decreasing the standard deviation of the estimates of the remaining theological parameters significantly. Using a PLSR model, a reasonable prediction of apparent viscosity (mu(app)), yield stress (tau......). Validation on an independent test set yielded a root mean square error of 1.21 Pa for tau(y), 0.209 Pa s" for K, and 0.0288 Pa s for mu(app), corresponding to R-2 = 0.95, R-2 = 0.94, and R-2 = 0.95 respectively....

  16. An integrated platform for gas-diffusion separation and electrochemical determination of ethanol on fermentation broths.

    Science.gov (United States)

    Giordano, Gabriela Furlan; Vieira, Luis Carlos Silveira; Gobbi, Angelo Luiz; Lima, Renato Sousa; Kubota, Lauro Tatsuo

    2015-05-22

    An integrated platform was developed for point-of-use determination of ethanol in sugar cane fermentation broths. Such analysis is important because ethanol reduces its fuel production efficiency by altering the alcoholic fermentation step when in excess. The custom-designed platform integrates gas diffusion separation with voltammetric detection in a single analysis module. The detector relied on a Ni(OH)2-modified electrode. It was stabilized by uniformly depositing cobalt and cadmium hydroxides as shown by XPS measurements. Such tests were in accordance with the hypothesis related to stabilization of the Ni(OH)2 structure by insertion of Co(2+) and Cd(2+) ions in this structure. The separation step, in turn, was based on a hydrophobic PTFE membrane, which separates the sample from receptor solution (electrolyte) where the electrodes were placed. Parameters of limit of detection and analytical sensitivity were estimated to be 0.2% v/v and 2.90 μA % (v/v)(-1), respectively. Samples of fermentation broth were analyzed by both standard addition method and direct interpolation in saline medium based-analytical curve. In this case, the saline solution exhibited ionic strength similar to those of the samples intended to surpass the tonometry colligative effect of the samples over analyte concentration data by attributing the reduction in quantity of diffused ethanol vapor majorly to the electrolyte. The approach of analytical curve provided rapid, simple and accurate analysis, thus contributing for deployment of point-of-use technologies. All of the results were accurate with respect to those obtained by FTIR method at 95% confidence level. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Recovery of ethanol from fermentation broths using selective sorption-desorption.

    Science.gov (United States)

    Pitt, W W; Haag, G L; Lee, D D

    1983-01-01

    Industrialized nations face a critical problem in replacing the sources of liquid fuels that traditionally have been supplied by petroleum. One solution that has gained increasing support in this country is the use of ethanol produced by fermentation of renewable biomass as an extender in, or supplement to, gasoline for transportation fuel. Distillation, the present method of separating ethanol from the fermentation broth, is an energy-intensive one and frequently uses more energy than is available from the ethanol recovered. There are many investigations under way to find alternative, less energy-intensive techniques for the ethanol-water separation. The separations method described in this article involves the use of solid materials to preferentially remove ethanol from fermentation broths. Subsequent stripping of the ethanol from the sorbent with a dry gas reduces dramatically the energy required for the separation. Three solid sorbents have been investigated experimentally. Their sorption/desorption characteristics are described, and their incorporation in an ethanol recovery process is evaluated. Three sorbents were investigated: two commercially available divinylbenzene crosslinked polystyrene resins in bead form (one with a nominal surface area of 300 m(2)/g, the other with 750 m(2)/g) and an experimental proprietary molecular sieve with hydrophobic properties. Equilibrium adsorption isotherms for two of the sorbents were obtained at ambient temperature (21 degrees C) for ethanol-water solutions containing up to 12 wt. % ethanol. In addition, 40 degrees C isotherms were obtained for the polystyrene sorbents. Although different, the equilibrium isotherms for the sorbents indicated that ethanol could be preferentially sorbed from a dilute solution. Column breakthrough curves indicated very favorable kinetics. Desorption of the ethanol was readily effected with warm (60-80 degrees C), dry nitrogen.

  18. Membrane fouling mechanism in ultrafiltration of succinic acid fermentation broth.

    Science.gov (United States)

    Wang, Caixia; Li, Qiang; Tang, Huang; Yan, Daojiang; Zhou, Wei; Xing, Jianmin; Wan, Yinhua

    2012-07-01

    The membrane fouling mechanism was studied in treating succinic acid fermentation broth during dead-end ultrafiltration. Different membranes were used and two models were applied to analyze the fouling mechanism. Resistance-in-series model was applied to determine the main factor that caused the operation resistance. Results indicated that most membranes tended to be fouled by cake layer or concentration polarization. Hermia's model, which is composed of four individual sub-models, was used to analyze the predominant fouling mechanism. Results showed that the fouling of RC 10 kDa and PES 30 kDa was controlled by the complete blocking mechanism, while PES 100 kDa was controlled by the intermediate blocking and PES 10 kDa was controlled by cake layer. This conclusion was also proved by SEM photos. Membrane characteristics were monitored before and after ultrafiltration by AFM and goniometer. Both contact angle and roughness of most membranes increased after ultrafiltration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Wild-Type MIC Distributions and Epidemiological Cutoff Values for Posaconazole and Voriconazole and Candida spp. as Determined by 24-Hour CLSI Broth Microdilution▿

    Science.gov (United States)

    Pfaller, M. A.; Boyken, L.; Hollis, R. J.; Kroeger, J.; Messer, S. A.; Tendolkar, S.; Diekema, D. J.

    2011-01-01

    We tested 16,191 strains of Candida against posaconazole and voriconazole, using the CLSI M27-A3 broth microdilution (BMD) method (24-h incubation), in order to define wild-type (WT) populations and epidemiological cutoff values (ECVs). From 2001 to 2009, 8,619 isolates of Candida albicans, 2,415 isolates of C. glabrata, 2,278 isolates of C. parapsilosis, 1,895 isolates of C. tropicalis, 508 isolates of C. krusei, 205 isolates of C. lusitaniae, 177 isolates of C. guilliermondii, and 93 isolates of C. kefyr were obtained from over 100 centers worldwide. The modal MICs (μg/ml) for posaconazole and voriconazole, respectively, were as follows: for C. albicans, 0.016 and 0.007; for C. glabrata, 0.5 and 0.06; for C. parapsilosis, 0.06 and 0.007; for C. tropicalis, 0.03 and 0.015; for C. krusei, 0.25 and 0.12; for C. lusitaniae, 0.03 and 0.007; for C. guilliermondii, 0.12 and 0.03; and for C. kefyr, 0.06 and 0.007. The ECVs (μg/ml [% of isolates that had MICs equal to or less than the ECV]) for posaconazole and voriconazole, respectively, were as follows: 0.06 (98.5) and 0.03 (98.9) for C. albicans, 2 (96.2) and 0.5 (90.4%) for C. glabrata, 0.25 (99.3) and 0.12 (97.9) for C. parapsilosis, 0.12 (97.6) and 0.06 (97.2) for C. tropicalis, 0.5 (99.8) and 0.5 (99.4) for C. krusei, 0.12 (95.6) and 0.03 (96.6) for C. lusitaniae, 0.5 (98.9) and 0.25 (98.3) for C. guilliermondii, and 0.25 (100.0) and 0.015 (100.0) for C. kefyr. In the absence of clinical breakpoints (CBPs) for posaconazole, these WT distributions and ECVs will be useful in surveillance for emergence of reduced susceptibility to posaconazole among Candida spp. Whereas a CBP for susceptibility of ≤1 μg/ml has been established for voriconazole and all species of Candida, it is notable that ECVs for this agent range from 10- to >100-fold lower than the CBP, depending on the species of Candida. The CBP is inadequate in detecting the emergence of voriconazole resistance among most Candida species encountered

  20. First comprehensive evaluation of the M.I.C. evaluator device compared to Etest and CLSI reference dilution methods for antimicrobial susceptibility testing of clinical strains of anaerobes and other fastidious bacterial species.

    Science.gov (United States)

    Rennie, R P; Turnbull, L; Brosnikoff, C; Cloke, J

    2012-04-01

    The new M.I.C. Evaluator strip uses test methodology and the recording of results that are similar to those of Etest. For this first assessment, 102 clinical strains of anaerobic bacteria from 12 genera and 155 strains from 7 genera and 8 species of fastidious bacteria were tested by M.I.C. Evaluator, Etest, and agar dilution or broth microdilution as a reference standard. Ampicillin, amoxicillin, amoxicillin-clavulanate, cefotaxime, ciprofloxacin, erythromycin, imipenem, levofloxacin, metronidazole, penicillin, and tetracycline were tested depending on the species. Agar dilution for anaerobes was performed according to CLSI document M11-A7. For the fastidious bacteria, CLSI document M45-A2 was followed. For the anaerobes, essential and categorical agreement between M.I.C. Evaluator and Etest was >90%. Compared to agar dilution, essential agreement was low for both strip tests, and many very major errors were observed for metronidazole (13 to 14%) and penicillin (8 to 9%) with isolates from the Bacteroides fragilis group and Clostridium species. For fastidious species, essential agreements for M.I.C. Evaluator and Etest plus or minus one doubling dilution were >95%. Compared to broth microdilution, essential agreements were low (40 to 90%) plus or minus one dilution and were >90% plus or minus two dilutions, with high overall category agreement (CA). Major and minor errors were within established parameters for all strains tested. The M.I.C. Evaluator strips were equivalent to Etest for anaerobes and fastidious species. These observations require further investigation to determine which methods provide the most accurate MIC for clinical utility. The further evaluation of additional M.I.C. Evaluator agents will be performed as they become available.

  1. Lethal paralytic shellfish poisoning from consumption of green mussel broth, Western Samar, Philippines, August 2013

    Directory of Open Access Journals (Sweden)

    Paola Katrina Ching

    2015-05-01

    Full Text Available Background: In July 2013, the Philippines’ Event-Based Surveillance & Response Unit received a paralytic shellfish poisoning (PSP report from Tarangnan, Western Samar. A team from the Department of Health conducted an outbreak investigation to identify the implicated source and risk factors in coastal villages known for green mussel production and exportation. Methods: A case was defined as a previously well individual from Tarangan, Western Samar who developed gastrointestinal symptoms and any motor and/or sensory symptoms after consumption of shellfish from 29 June to 4 July 2013 in the absence of any known cause. The team reviewed medical records, conducted active case finding and a case-control study. Relatives of cases who died were interviewed. Sera and urine specimens, green mussel and seawater samples were tested for saxitoxin levels using high performance liquid chromatography. Results: Thirty-one cases and two deaths were identified. Consumption of >1 cup of green mussel broth was associated with being a case. Seawater sample was positive for Pyrodinium bahamense var. compressum and green mussel samples were positive for saxitoxin. Inspection revealed villagers practice open defecation and improper garbage disposal. Conclusion: This PSP outbreak was caused by the consumption of the green mussel broth contaminated by saxitoxin. As a result of this outbreak, dinoflagellate and saxitoxin surveillance was established, and since the outbreak, there have been no harmful algal blooms event or PSP case reported since. A “Save Cambatutay Bay” movement, focusing on proper waste disposal practice and clean-up drives has been mobilized.

  2. Response surface methodology to design a selective co-enrichment broth of Escherichia coli, Salmonella spp. and Staphylococcus aureus for simultaneous detection by multiplex PCR.

    Science.gov (United States)

    Zhang, Qiao Yan; Zhou, Wen Wu; Zhou, Yu; Wang, Xiao Fu; Xu, Jun Feng

    2012-07-25

    Escherichia coli, Salmonella spp. and Staphylococcus aureus are frequent co-visitors of contaminated foods to cause food-borne diseases. To achieve rapid detection of three organisms by multiplex PCR, a selective co-enrichment broth was considered to design using response surface methodology (RSM) in this work. NaCl, LiCl and KSCN as selective bacterial inhibitors were selected to optimize their concentrations for a matched composition of bacterial biomass with uniform amplification of three targets. Central composite design was employed to collect the data and fit the responses. Three quadratic polynomial models were derived by computer simulation. A statistical analysis was carried out to explore the effects of the variables on the composition of bacterial biomass and PCR amplification yields. In the end, a novel broth (ESS-3 broth) of NaCl 1.60%, LiCl 0.70%, KSCN 0.10% was formulated to allow co-enrichment of the target pathogens and suppress growth of some non-target pathogens. The simultaneous detection of E. coli, Salmonella spp. and S. aureus was developed on a rapid, convenient and sensitive method consisting of selective co-enrichment in ESS-3 broth, DNA extraction with the boiling method and robust test by multiplex PCR. Our work provided broader application of RSM for the simultaneous detection of other combinations of multiple pathogens. Copyright © 2012 Elsevier GmbH. All rights reserved.

  3. Evaluation of a multiplex selective enrichment broth SEL for simultaneous detection of injured Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes.

    Science.gov (United States)

    Suo, Biao; Wang, Yuexia

    2013-01-01

    Although many rapid and high throughput molecular methods have been developed in the recent years for the multiplex detection of foodborne pathogens, the simultaneous recovery and enrichment of sublethally injured cells is still a problem that needs to be considered. Combined with previous established multiplex real-time PCR assay, the capability of simultaneous recovery and enrichment of sublethally injured Salmonella, E. coli O157:H7 and L. monocytogenes cells was evaluated in a multiplex selective enrichment broth SEL. The injured cells were obtained by heat shock. After evaluation of different procedures, 1 h of recovery period prior to 20 h of enrichment was proved to be necessary for the detection of less than 10 CFU/5 mL broth of injured L. monocytogenes. When the detection method was applied to artificially contaminated ground beef, all the three injured pathogens could be simultaneously detected without discrimination by real-time PCR combined with SEL broth, the detection limit was SEL broth herein appears to be a promising tool for high-throughput screening of a large number of processed food samples, which require either single or multiple pathogen detection. More important, the sublethally injured foodborne pathogen cells were also detectable.

  4. Colorimetric Microtiter Plate Assay of Polycationic Aminoglycoside Antibiotics in Culture Broth Using Amaranth.

    Science.gov (United States)

    Katano, Hajime; Kuroda, Yasuhiro; Taira, Shu; Maruyama, Chitose; Hamano, Yoshimitsu

    2017-01-01

    We present a colorimetric method for the detection of aminoglycoside antibiotics such as neomycin (NEO) using a reddish anionic dye, amaranth (AR(3-)). Under acidic conditions, at which NEO exists in fully protonated form (NEOH(6+)), the AR(3-) anion associates with the NEOH(6+) cation to form a precipitate, NEOH(AR)2. The precipitate was soluble in a buffer solution of pH 8.5, yielding a reddish solution with an absorption maximum at around 520 nm. Tobramycin and gentamycin, which exist as pentavalent cations under acidic conditions, gave almost the same results. On the other hand, kanamycin, amikacin and streptomycin, which would exist as tri- and tetravalent cations, were not precipitated. Thus, the AR(3-) anion could be considered to be an analytical reagent for specific aminoglycosides with polycationic functionality. However, since the precipitation reaction was considerably affected by other anions, a separation method using the tetraphenylborate anion was employed as a pretreatment. The separation method involves precipitating the polycationic aminoglycosides with the tetraphenylborate anion, washing the precipitate with acetonitrile, and re-precipitating the aminoglycosides as hydrochloride salts. Thus, the present method was applied to a microtiter plate assay of the products in an NEO-producing culture broth.

  5. [Kinetic simulation of enhanced biological phosphorus removal with fermentation broth as carbon source].

    Science.gov (United States)

    Zhang, Chao; Chen, Yin-Guang

    2013-07-01

    As a high-quality carbon source, fermentation broth could promote the phosphorus removal efficiency in enhanced biological phosphorus removal (EBPR). The transformation of substrates in EBPR fed with fermentation broth was well simulated using the modified activated sludge model No. 2 (ASM2) based on the carbon source metabolism. When fermentation broth was used as the sole carbon source, it was found that heterotrophic bacteria acted as a promoter rather than a competitor to the phosphorus accumulating organisms (PAO). When fermentation broth was used as a supplementary carbon source of real municipal wastewater, the wastewater composition was optimized for PAO growth; and the PAO concentration, which was increased by 3.3 times compared to that in EBPR fed with solely real municipal wastewater, accounting for about 40% of the total biomass in the reactor.

  6. Membrane-based recovery and dehydration of alcohols from fermentation broths - of materials and modules

    Science.gov (United States)

    Distillation combined with molecular sieve dehydration is the current state of the art for fuel grade ethanol production from fermentation broths. As the liquid biofuels industry transitions to lignocellulosic feedstocks, expands the end product portfolio to include other alcoho...

  7. Energy efficient recovery and dehydration of ethanol from fermentation broths by Membrane Assisted Vapor Stripping technology

    Science.gov (United States)

    Distillation combined with molecular sieve dehydration is the current state of the art for fuel grade ethanol production from fermentation broths. To improve the sustainability of bioethanol production, energy efficient separation alternatives are needed, particularly for lower ...

  8. SST broth, a new serum free germ tube induction medium for identification of Candida albicans.

    Science.gov (United States)

    Raghunath, Pendru; Seshu Kumari, K; Subbannayya, K

    2014-07-01

    Three serum free media viz, sucrose solution, starch solution and SST broth have been formulated. The objective of the present study was to evaluate these three different serum free media for induction of germ tubes by Candida albicans and to compare their efficacy with the pooled human serum. Out of 50 C. albicans isolates 47 (94%) and 49 (98%) produced germ tubes in pooled human serum and SST broth, respectively. Germ tube production was positive in 40 (80%) and 36 (72%) isolates, respectively in sucrose solution and starch solution. This study reports SST broth as a new stable and less expensive germ tube induction medium, which requires less time for preparation and can be used without any safety concerns. SST broth is found to be more effective than pooled human serum for induction of germ tubes by C. albicans isolates.

  9. Comparison of Broth and Human Serum as the Diluent in the Serum Bactericidal Test

    Science.gov (United States)

    Pien, F. D.; Williams, R. D.; Vosti, K. L.

    1975-01-01

    The use of serum rather than broth as the diluent in the serum bactericidal test results in a significant decrease in the test level among patients receiving highly protein-bound semisynthetic penicillins. PMID:1137355

  10. Sapodilla (Manilkara zapota Broth as an Alternative Media for Candida albicans

    Directory of Open Access Journals (Sweden)

    Chen Chui Ying

    2017-03-01

    Full Text Available Objective: To determine whether sapodilla can be used to grow Candida albicans. Among all the high galactose and arabinose content fruits, the sapodilla was chosen because it is available year round and can get easily in market. Other than that, it also contains vitamins, calcium and phosphorus which are very useful for fungi growth. Methods: This study used an experimental study as a method of research. The researcher culture Candida albicans on the experimental sapodilla media and identifies the morphology of the fungi by using Gram staining method. The experiment will be replicated two times to get accurate result. The procedure of this experiment constitute of sapodilla media preparation, sapodilla media observation, organism preparation, planting and incubation, observation of fungal colonies and identification of the fungi. Results: In 0%, there was no fungal growth at all. In 5%, there was mild density of fungal colonies. In 10%, there was moderate density of fungal colonies and in 15% the fungal grew with very dense colonies. Conclusions: Sapodilla (Manilkara zapota broth can be used as an alternative media for Candida albicans.

  11. Anticlastogenic and bio-antimutagenic activity of cultured broth of Saccharomyces cerevisiae 28 on mutagens.

    Science.gov (United States)

    Zhang, X B; Ohta, Y

    1993-08-01

    The possible anticlastogenic activity and bio-antimutagenic mechanism of the cultured broth of Saccharomyces cerevisiae 28 were examined using in in vivo and in vitro test systems. In the Ames test with Salmonella typhimurium TA100 (SD-) and in the umu-test with S. typhimurium TA1535/psk1002, the cultured broth of S. cerevisiae 28 showed bio-antimutagenic activity against mutagenicity induced by 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ). The cultured broth also showed bio-antimutagenic activity towards reverse mutations induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in Escherichia coli B/r WP2 trp-, but not by UV radiation. It is clear that the cultured broth could inhibit base substitution mutations induced by mutagens. Using mitomycin C (MMC) as a mutagen, the micronucleus test (with bone marrow cells of mice) showed anticlastogenic action when the cultured broth was given orally to mice. Micronucleated polychromatic erythrocytes induced by the mutagen were reduced by about 47% by the cultured broth.

  12. The antimicrobial effects of selenium nanoparticle-enriched probiotics and their fermented broth against Candida albicans.

    Science.gov (United States)

    Kheradmand, Erfan; Rafii, Fatemeh; Yazdi, Mohammad Hossien; Sepahi, Abas Akhavan; Shahverdi, Ahmad Reza; Oveisi, Mohammad Reza

    2014-06-06

    Lactic acid bacteria are considered important probiotics for prevention of some infections. The aim of this work was to investigate the effect of selenium dioxide on the antifungal activity of Lactobacillus plantarum and L. johnsonii against Candida albicans. Lactobacillus plantarum and L. johnsonii cells, grown in the presence and absence of selenium dioxide, and their cell-free spent culture media were tested for antifungal activity against C. albicans ATCC 14053 by a hole-plate diffusion method and a time-kill assay. Both L. plantarum and L. johnsonii reduced selenium dioxide to cell-associated elemental selenium nanoparticles. The cell-free spent culture media, from both Lactobacillus species that had been grown with selenium dioxide for 48 h, showed enhanced antifungal activity against C. albicans. Enhanced antifungal activity of cell biomass against C. albicans was also observed in cultures grown with selenium dioxide. Selenium dioxide-treated Lactobacillus spp. or their cell-free spent broth inhibited the growth of C. albicans and should be investigated for possible use in anti-Candida probiotic formulations in future.

  13. Isolation of α-arbutin from Xanthomonas CGMCC 1243 fermentation broth by macroporous resin adsorption chromatography.

    Science.gov (United States)

    Liu, Chunqiao; Zhang, Peng; Liu, Luo; Xu, Tao; Tan, Tianwei; Wang, Fang; Deng, Li

    2013-04-15

    α-Arbutin is a glycosylated hydroquinone which has inhibitory function against tyrosinase. In this work, a one-step isolation of α-arbutin from Xanthomonas CGMCC 1243 fermentation broth by macroporous resin adsorption chromatography was investigated. The research results indicated that S-8 resin offered the best adsorption and desorption capacities for α-arbutin than others and its equilibrium adsorption data were well-fitted to the Freundlich isotherm. In order to optimize the operating parameters for separating α-arbutin, dynamic adsorption and desorption tests on S-8 column chromatography were carried out. Under optimized conditions (adsorption volume of 7 bed volume (BV), mobile phase of 25% (v/v) ethanol solution and elution volume of 3 BV), the purity and recovery of α-arbutin were 97.3% (w/w) and 90.9% (w/w), respectively. The product was identified as α-arbutin by (13)C NMR and (1)H NMR analysis. Moreover, we scaled up S-8 column from laboratory test (10 cm × 2 cm ID) to large scale (500 cm × 100 cm ID) without diminishing α-arbutin yield. In conclusion, the results in this work provide a one-step and cost-effective method for large-scale production of α-arbutin. Copyright © 2013. Published by Elsevier B.V.

  14. Comparison of susceptibility patterns using commercially available susceptibility testing methods performed on prevalent Candida spp.

    Science.gov (United States)

    Cretella, David; Barber, Katie E; King, S Travis; Stover, Kayla R

    2016-12-01

    The rising rates of invasive fungal infections caused by non-albicans Candida and the increasing emergence of antifungal resistance complicate the management of invasive candidiasis. Accurate and timely antifungal susceptibility testing is critical to targeting antifungal therapy. The purpose of this study was to compare commercially available susceptibility testing methods using prospectively collected Candida isolates. Susceptibility testing was performed on 74 Candida isolates collected from July 2014 to March 2015 using broth microdilution according to the Clinical and Laboratory Standards Institute method, Etest, Vitek 2 (YS-05) and Sensititre. Essential agreement and categorical agreement (CA) were assessed using the reference method. Of the 34 total blood isolates collected, Candida albicans comprised only 38 % (13) of the Candida spp. with Candidaglabrata being nearly as prevalent (29 %, 10). CA using Etest was 86 % for fluconazole, 72 % for caspofungin, 98 % for micafungin and 97 % for anidulafungin. Vitek 2 CA was 90 % for fluconazole and 98 % for caspofungin. Sensititre CA was 93 % for fluconazole, 98 % for caspofungin, 98 % for micafungin and 100 % for anidulafungin. Although our study tested a small population of Candida isolates, our results were variable by method. When implementing antifungal susceptibility testing, clinicians should be aware of the strengths and limitations of each testing method.

  15. Broth versus solid agar culture of swab samples of cadaveric allograft musculoskeletal tissue.

    Science.gov (United States)

    Varettas, Kerry

    2013-12-01

    As part of the donor assessment protocol, bioburden assessment must be performed on allograft musculoskeletal tissue samples collected at the time of tissue retrieval. Swab samples of musculoskeletal tissue allografts from cadaveric donors are received at the microbiology department of the South Eastern Area Laboratory Services (Australia) to determine the presence of bacteria and fungi. This study will review the isolation rate of organisms from solid agar and broth culture of swab samples of cadaveric allograft musculoskeletal tissue over a 6-year period, 2006-2011. Swabs were inoculated onto horse blood agar (anaerobic, 35 °C) and chocolate agar (CO2, 35 °C) and then placed into a cooked meat broth (aerobic, 35 °C). A total of 1,912 swabs from 389 donors were received during the study period. 557 (29.1 %) swabs were culture positive with the isolation of 713 organisms, 249 (34.9 %) from solid agar culture and an additional 464 (65.1 %) from broth culture only. This study has shown that the broth culture of cadaveric allograft musculoskeletal swab samples recovered a greater amount of organisms than solid agar culture. Isolates such as Clostridium species and Staphylococcus aureus would not have been isolated from solid agar culture alone. Broth culture is an essential part of the bioburden assessment protocol of swab samples of cadaveric allograft musculoskeletal tissue in this laboratory.

  16. Effect of redox potential on Bacillus subtilis and Bacillus licheniformis in broth and in pasteurized sausage mixtures.

    Science.gov (United States)

    Rödel, W; Lücke, F K

    1990-05-01

    Bacillus licheniformis (a facultatively anaerobe) and B. subtilis (aerobic) may cause spoilage in certain meat products pasteurized in hermetically sealed containers if these are stored with inadequate refrigeration. After having optimized a method for determination of the redox potential in sausage mixtures, we investigated the contribution of low redox potential (Eh) and anaerobiosis to the inhibition of these bacilli. With the Eh values encountered in pasteurized meat products there was no effect of the redox potential on growth of B. licheniformis, either in model broths or in mildly heated bologna-type sausage mixtures. When cultured in a model broth with head space, B. subtilis grew to about 10(7)/ml and was little affected by the initial Eh value (range between +250 and -150 mV) and the initial dissolved oxygen concentration. During exponential growth of this bacterium in the absence of oxygen, the Eh value increased by about 180 mV. In sausage mixture with air inclusions, B. subtilis attained slightly higher cell densities than in mixtures protected against air uptake but it was subsequently overgrown by facultative anaerobic bacilli. We conclude that knowledge of the Eh value of a meat product does not permit a prediction of the growth potential of bacilli in pasteurized meat products, and that a sufficient heat treatment and proper refrigeration are essential to control these bacteria.

  17. Screening femoral heads from living donors: a prospective study comparing swab-agar versus bone fragment-broth culture.

    Science.gov (United States)

    Saegeman, Veroniek; Verhaegen, Jan; Simon, Jean-Pierre

    2011-06-01

    Femoral heads are an important source of allograft bone used in reconstructive orthopaedic surgery. The sterility of donor material is of major importance for the recipient. Femoral heads intraoperatively retrieved during hip arthroplasty from medically screened living donors are routinely checked with a surface swab to exclude microbiological contamination. There is, however, evidence that swab cultures have limited sensitivity. We therefore prospectively compared two ways of screening femoral heads. Bacterial recovery from swabs in Amies transport medium taken intraoperatively, subsequently transported to the microbiology laboratory and inoculated on agar and in broth was compared with the recovery from a bone fragment also taken intraoperatively but immediately inoculated into Wilkins Chalgren broth. Forty femoral heads were tested with both methods. Bacteria were cultured neither from the femoral surface swabs nor from the femoral fragments. Consequently no distinct conclusions regarding the sensitivity of both techniques could be drawn. In addition the bacterial yield of two swabs in Amies transport medium streaked on a variety of culture media other than the conventional agar plates was also studied. Culturing of these swabs resulted in the detection of bacteria that are predominantly considered contaminants.

  18. Hydrodynamics in bubble column bioreactors with fermentation broths having a yield stress

    Energy Technology Data Exchange (ETDEWEB)

    Kawase, Y.; Moo-Young, M.

    1989-06-01

    The hydrodynamics in a bubble column bioreactor with fermentation broths having a yield stress are studied. Specifically, the liquid velocity at the reactor axis, the axial dispersion coefficient, and the gas hold-up are examined. The liquid velocity at the reactor axis and the gas hold-up are measured in a 40-l bench-scale bubble column fermentor using carboxypolymethylene (Carbopol) aqueous solutions as simulated broths. Theoretical correlations for the liquid velocity at the reactor axis, the axial dispersion coefficient, and the gas hold-up are derived on the basis of an energy balance and the mixing length theory. The correlations are compared with the present data and a reasonable agreement is found. The theoretical predictions are also in satisfactory agreement with the re-examined data for actual fermentation broths which are Chaetomium cellulolyticum and Neurospora sitophila cultured in a 1000-l pilot-plant scale airlift fermentor.

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

    Science.gov (United States)

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

    2016-07-01

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

  20. effective extraction of cephalosporin c from whole fermentation broth ...

    African Journals Online (AJOL)

    amina

    2012-04-17

    Apr 17, 2012 ... Key words: Cephalosporin C, Acremonium chrysogenum, fermentation, aqueous two phase system (ATPS). .... MATERIALS AND METHODS ... It is observed from results (Figure 5) that maximum extraction was achieved at neutral pH 7. The change in the yield was not pronounced between pH 6 to 7.

  1. Detection of Pseudomonas fluorescens from broth, water and ...

    African Journals Online (AJOL)

    Loop mediated isothermal amplification is rapid, highly sensitive and specifically developed method for detection of bacterial infections. AprX gene for alkaline metalloprotease of Pseudomonas fluorescens was used to design four primers and loop mediated isothermal amplification (LAMP) conditions were standardized for ...

  2. Susceptibility of MDR Pseudomonas aeruginosa to ceftolozane/tazobactam and comparison of different susceptibility testing methods.

    Science.gov (United States)

    Schaumburg, Frieder; Bletz, Stefan; Mellmann, Alexander; Becker, Karsten; Idelevich, Evgeny A

    2017-08-11

    Infections caused by MDR Pseudomonas aeruginosa are on the rise, particularly in critically ill patients. Therefore, there is a need to evaluate new antimicrobial regimens. The objectives of this study were to investigate the ceftolozane/tazobactam resistance rates of MDR and XDR P. aeruginosa , the underlying resistance genes, the clonal structure and different antimicrobial susceptibility testing (AST) methods regarding their accuracy for ceftolozane/tazobactam testing. In total, 112 MDR and XDR P. aeruginosa (from infection and colonization) from one German tertiary care hospital were included (2013-16). AST was done using broth microdilution (BMD), gradient diffusion test strips and disc diffusion. Resistance genes were screened by PCR. A randomly selected subset of 77 isolates was subjected to WGS to assess the clonal structure. In total, 38 isolates (33.9%) were resistant to ceftolozane/tazobactam according to the BMD reference method. Resistance was significantly lower in MDR P. aeruginosa (4.8%) compared with XDR P. aeruginosa (50%, P  MDR P. aeruginosa , but higher in XDR P. aeruginosa . The disc diffusion method showed an acceptable accuracy for ceftolozane/tazobactam AST.

  3. Development of a multi-pathogen enrichment broth for simultaneous growth of five common foodborne pathogens.

    Science.gov (United States)

    Chen, Juan; Tang, Junni; Bhunia, Arun K; Tang, Cheng; Wang, Changting; Shi, Hui

    2015-01-01

    The objective of the present study was to formulate a multi-pathogen enrichment broth which could support the simultaneous growth of five common foodborne pathogens (Salmonella enterica, Staphylococcus aureus, Shigella flexneri, Listeria monocytogenes and Escherichia coli O157:H7). The formulated broth SSSLE was composed of potassium tellurite, bile salt, lithium chloride, and sodium chloride as growth-inhibitors; glucose, esculin, mannitol and sodium pyruvate as growth-promoters. Compared with the respective specific selective enrichment broths, the individual growth pattern of each target pathogen in SSSLE was equal, or even better, except in the case of S. flexneri. In mixed-culture experiments, the gram-negative bacteria showed higher growth capabilities than the gram-positive bacteria after 8-h enrichment; however, the cell numbers after 24-h enrichment indicated that SSSLE could support the concurrent growth of five target pathogens irrespective of whether pathogens were inoculated initially at equal or unequal levels. For natural food samples under the high background flora, the final cell numbers enriched in SSSLE for five targets were enough to be detected by multiplex PCR. In conclusion, SSSLE was capable of supporting the growth of five target pathogens concurrently. The new broth formulated in this study has the potential of saving time, efforts and costs in multi-pathogen enrichment procedures.

  4. Study of a cleaner extraction of pyruvic acid from fermentation broth ...

    African Journals Online (AJOL)

    A new cleaner technology for extracting pyruvic acid (PA) from fermentative broth was explored. This process involves recycling waste residue combined with small amount of dispersant added to extract PA. Limited amount of dispersant in the process of rectification under vacuum (1.5 kPa) was found to inhibit the ...

  5. Recovery of butanol from Clostridium beijerinckii P260 fermentation broth by supercritical CO

    Science.gov (United States)

    Butanol is a superior biofuel to ethanol because of its blend properties and higher energy density. However, its recovery by distillation from the fermentation broth is energy intensive. For this reason, we studied butanol recovery by supercritical CO2 extraction from simulated and actual fermentati...

  6. Use of liquid/supercritical CO2 extraction process for butanol recovery from fermentation broth

    Science.gov (United States)

    In order for butanol fermentation to be a viable option, it is essential to recover it from fermentation broth using economical alternate in-situ product recovery techniques such as liquid/supercritical CO2 extraction as compared to distillation. This technique (liquid CO2 extraction & supercritical...

  7. ANTIFUNGAL ACTIVITY OF NEEM (Azadirachta indica: MELIACEAE) EXTRACTS AGAINST DERMATOPHYTES

    National Research Council Canada - National Science Library

    OSPINA SALAZAR, Daniel Iván; HOYOS SÁNCHEZ, Rodrigo Alberto; OROZCO SÁNCHEZ, Fernando; ARANGO ARTEAGA, Myrtha; GÓMEZ LONDOÑO, Luisa Fernanda

    2015-01-01

    ... (Azadirachta indica A. Juss.), several bioassays were conducted following M38-A2 broth microdilution method on 14 isolates of the dermatophytes Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis and Epidermophyton floccosum...

  8. Differences in the antimicrobial susceptibility profiles of Moraxella bovis, M. bovoculi and M. ovis

    National Research Council Canada - National Science Library

    Grazieli Maboni; Leticia T Gressler; Julia P Espindola; Marcelo Schwab; Caiane Tasca; Luciana Potter; Agueda Castagna Devargas

    2015-01-01

    .... Thirty-two strains of Moraxella spp. isolated from cattle and sheep with infectious keratoconjunctivitis were tested via broth microdilution method to determine their susceptibility to ampicillin, cefoperazone, ceftiofur, cloxacillin...

  9. Isolation and Characterization of Exopolysaccharide with Immunomodulatory Activity from Fermentation Broth of Morchella Conica

    Directory of Open Access Journals (Sweden)

    Chao-an Su

    2013-01-01

    Full Text Available Background and the purpose of this study: Mushroom polysaccharides have traditionally been used for the prevention and treatment of a multitude of disorders like infectious illnesses, cancers and various autoimmune diseases. In vitro and in vivo studies suggest that certain polysaccharides affect immune system function. Morchella conica (M. conica is a species of rare edible mushroom whose multiple medicinal functions have been proven. Thus, the objective of this study is to isolate and characterize of exopolysaccharide from submerged mycelial culture of M. conica, and to evaluate its immunomodulatory activity.MethodsA water-soluble Morchella conica Polysaccharides (MCP were extracted and isolated from the fermentation broth of M. conica through a combination of DEAE-cellulose and Sephacryl S-300 HR chromatograph. NMR and IR spectroscopy has played a developing role in identification of polysaccharide with different structure and composition from fungal and plant sources, as well as complex glycosaminoglycans of animal origin. Thus, NMR and IR spectroscopy were used to analyze the chemical structure and composition of the isolated polysaccharide. Moreover, the polysaccharide was tested for its immunomodulatory activity at different concentrations using in vitro model.ResultsThe results showed that MCP may significantly modulate nitric oxide production in macrophages, and promote splenocytes proliferation. Analysis from HPLC, infrared spectra and nuclear magnetic resonance spectroscopy showed that MCP was a homogeneous mannan with an average molecular weight of approximately 81.2 kDa. The glycosidic bond links is [rightwards arrow]6-alpha-D-Man p-(1[rightwards arrow].ConclusionThe results suggested that the extracted MCP may modulate nitric oxide production in macrophages and promote splenocytes proliferation, and it may act as a potent immunomodulatory agent.

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

    Directory of Open Access Journals (Sweden)

    Patrícia da Silva Nascente

    2003-12-01

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

  11. Anticandidal activity of pomegranate peel extract aerosol as an applicable sanitizing method.

    Science.gov (United States)

    Tayel, Ahmed A; El-Tras, Wael F

    2010-03-01

    Pomegranate is a wonderful fruit from the paradise which contains a wide variety of precious phytochemical compounds applicable in the fields of therapeutics and health care. Candida albicans is the most common etiological agent for many clinical mycoses which could lead to human and animal death. Determination of the anticandidal activity of pomegranate peel extracts (PPE), and application of PPE aerosol as sanitizer agent against C. albicans contamination were investigated. Agar diffusion assay and broth microdilution susceptibility test were applied for qualitative and quantitative determining the PPE anticandidal activity, respectively, versus commonly used fungicides. Aerosolization of PPE using an experimentally designed sanitizer room was applied for examining C. albicans sanitation potentiality of extract. PPE exhibited potent anticandidal activity against C. albicans strains comparing with standard fungicides in both used susceptibility techniques. Methanol, ethanol and water extracts were the most effective for inhibiting C. albicans growth. PPE aerosol was an efficient method for complete sanitizing of semi-closed places against C. albicans growth. Application of PPE aerosol is a proper sanitizing method for preventing C. albicans contamination and growth in suspected places.

  12. Characterization and Antimicrobial Activity of Silver Doped Hydroxyapatite Obtained by the Microwave Method

    Directory of Open Access Journals (Sweden)

    Meruyert KOIZHAIGANOVA

    2016-09-01

    Full Text Available In this study, silver (Ag doped hydroxyapatite (HA was produced by the microwave method and its antimicrobial activity was investigated. The physical, chemical and structural characteristics of the material were determined using multi-purpose X-ray diffractometry (XRD, Fourier transform infrared spectrometry (FTIR, and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS apparatus. The amount of silver in the solutions of silver-doped hydroxyapatite obtained were determined with the use of an inductively coupled plasma optical emission spectroscopy instrument (ICP-OES. The minimum inhibition concentration (MIC of the silver doped hydroxyapatite (Ag-HA against the test microorganisms was determined by the Broth Microdilution method. It was established that a concentration of 2.09-12.25 µg/ml was effective against gram-negative bacteria (Escherichia coli ATCC 12228, Salmonella typhimurium CCM 5445, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae CCM 2318, and 4.18-12.25 µg/ml was effective against gram-positive bacteria (Staphylococcus aureus ATCC6538-P, Bacillus subtilis ATCC 6633, Enterococcus faecalis ATCC 29212 and the yeast Candida albicans ATCC 10239.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.12133

  13. Rapid Identification of Staphylococcus aureus Directly from Bactec Blood Culture Broth by the BinaxNOW S. aureus Test

    OpenAIRE

    Qian, Qinfang; Eichelberger, Karen; Kirby, James E.

    2014-01-01

    The BinaxNOW Staphylococcus aureus testing showed sensitivity, specificity, and positive and negative predicative values of 97.6%, 100%, 100%, and 98.4%, respectively, for identification of S. aureus from Bactec blood culture broth. Importantly, the test performed equally well on aerobic and anaerobic culture broth.

  14. Pyrroloquinoline quinone from Gluconobacter oxydans fermentation broth enhances superoxide anion-scavenging capacity of Cu/Zn-SOD.

    Science.gov (United States)

    Ma, Ke; Cui, Jun-Zhu; Ye, Jian-Bin; Hu, Xian-Mei; Ma, Ge-Li; Yang, Xue-Peng

    2017-09-01

    A bioassay-guided fractionation of extract from Gluconobacter oxydans fermentation broth afforded Compound 1, which was identified as pyrroloquinoline quinone (PQQ) by spectroscopic methods. PQQ has been shown to enhance the superoxide anion-scavenging capacity significantly for Cu/Zn-SOD. To illustrate the mechanism, the interaction between PQQ and Cu/Zn-SOD was investigated. The multiple binding sites involving hydrogen bonds and van der Waals force between PQQ and Cu/Zn-SOD were revealed by isothermal titration calorimetry. The α-helix content was increased in the Cu/Zn-SOD structure with the addition of PQQ into the solution through ultraviolet (UV) spectroscopy. These results indicated that PQQ could change the conformation of Cu/Zn-SOD through interaction, which could enhance its superoxide anion-scavenging capacity. Therefore, PQQ is a potential natural antioxidant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Isolation of recombinant proteins from culture broth by co-precipitation with an amino acid carrier to form stable dry powders.

    Science.gov (United States)

    Moore, Barry D; Deere, Joseph; Edrada-Ebel, RuAngelie; Ingram, Andrew; van der Walle, Christopher F

    2010-08-01

    Protein-coated microcrystals can be generated by co-precipitation of protein and a water-soluble crystalline carrier by addition to excess water miscible organic solvent. We have investigated this novel process for its utility in the concentration and partial purification of a recombinant protein exported into the culture broth during expression by Pichia pastoris. Co-precipitation with a L-glutamine carrier selectively isolated the protein content of the culture broth, with a minimal number of steps, and simultaneously removed contaminants including a novel yeast metabolite. This pigment co-elutes during aqueous chromatography but its elucidation as a benzoylated glycosamine suggested a simple route of removal by partition during the co-precipitation process. Scale-up of the process was readily achieved through in-line mixing and subsequent reconstitution of the dried protein-coated microcrystals yielded natively folded, bioactive protein. Additional washing of the crystals with saturated L-glutamine facilitated further purification of the recombinant protein immobilized on the L-glutamine carrier. Thus, we present a novel method for the harvesting of recombinant protein from culture broth as a dry powder, which may be of general applicability to bioprocessing. (c) 2010 Wiley Periodicals, Inc.

  16. Determination of erythromycins in fermentation broth using liquid phase extraction with back extraction combined with high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Fahimeh Kamarei

    2014-07-01

    Full Text Available Liquid phase extraction with back extraction (LPE-BE combined with high performance liquid chromatography-diode array detection (HPLC-DAD was applied for the extraction and determination of erythromycin A, B and C in fermentation broths. According to this procedure, the fermentation broth with the adjustment pH at a fixed value of 10 was first mixed with organic solvent (Vbroth/Vorg = 1.0. After shaking, the mixture was separated into two phases by microfuging at 13,000 rpm for 15 min. Then back extraction was performed into the acidic aqueous phase with pH 5.0 (Vorg/Vaq = 1.0. After centrifugation at 3000, the two phases were separated and 50 μL of the acidic aqueous phase was injected into the HPLC. The effects of different variables such as the nature of extraction solvent and the pH of samples and buffer were investigated. At the most appropriate conditions, dynamic linear ranges of 0.5–8, 0.1–0.9 and 0.1–0.9 mg mL−1 and limits of detection of 0.03, 0.003 and 0.002 mg mL−1 were obtained for erythromycin A, B and C, respectively. Relative standard deviations (RSDs of the proposed method were less than 9.5%. The mean recoveries were 99.5%. The proposed method is simple and sensitive with highly clean-up effect and it can be used for monitoring the progress of erythromycin fermentation.

  17. A simple one pot purification of bacterial amylase from fermented broth based on affinity toward starch-functionalized magnetic nanoparticle.

    Science.gov (United States)

    Paul, Tanima; Chatterjee, Saptarshi; Bandyopadhyay, Arghya; Chattopadhyay, Dwiptirtha; Basu, Semanti; Sarkar, Keka

    2015-08-18

    Surface-functionalized adsorbant particles in combination with magnetic separation techniques have received considerable attention in recent years. Selective manipulation on such magnetic nanoparticles permits separation with high affinity in the presence of other suspended solids. Amylase is used extensively in food and allied industries. Purification of amylase from bacterial sources is a matter of concern because most of the industrial need for amylase is met by microbial sources. Here we report a simple, cost-effective, one-pot purification technique for bacterial amylase directly from fermented broth of Bacillus megaterium utilizing starch-coated superparamagnetic iron oxide nanoparticles (SPION). SPION was prepared by co-precipitation method and then functionalized by starch coating. The synthesized nanoparticles were characterized by transmission electron microscopy (TEM), a superconducting quantum interference device (SQUID, zeta potential, and ultraviolet-visible (UV-vis) and Fourier-transform infrared (FTIR) spectroscopy. The starch-coated nanoparticles efficiently purified amylase from bacterial fermented broth with 93.22% recovery and 12.57-fold purification. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the molecular mass of the purified amylase was 67 kD, and native gel showed the retention of amylase activity even after purification. Optimum pH and temperature of the purified amylase were 7 and 50°C, respectively, and it was stable over a range of 20°C to 50°C. Hence, an improved one-pot bacterial amylase purification method was developed using starch-coated SPION.

  18. Comparison of the Sensititre YeastOne colorimetric antifungal panel with CLSI microdilution for antifungal susceptibility testing of the echinocandins against Candida spp., using new clinical breakpoints and epidemiological cutoff values.

    Science.gov (United States)

    Pfaller, M A; Chaturvedi, V; Diekema, D J; Ghannoum, M A; Holliday, N M; Killian, S B; Knapp, C C; Messer, S A; Miskou, A; Ramani, R

    2012-08-01

    A commercially prepared dried colorimetric microdilution panel (Sensititre Yeast One, TREK Diagnostic Systems, Cleveland, OH, USA) was compared in 3 different laboratories with the Clinical and Laboratory Standards Institute (CLSI) reference microdilution method by testing 2 quality control strains, 25 reproducibility strains, and 404 isolates of Candida spp. against anidulafungin, caspofungin, and micafungin. Reference CLSI BMD MIC end points and YeastOne colorimetric end points were read after 24 h of incubation. Excellent (100%) essential agreement (within 2 dilutions) between the reference and colorimetric MICs was observed. Categorical agreement (CA) between the 2 methods was assessed using the new species-specific clinical breakpoints (CBPs): susceptible (S), ≤0.25 μg/mL; intermediate (I), 0.5 μg/mL; and resistant (R), ≥1 μg/mL, for C. albicans, C. tropicalis, and C. krusei, and ≤2 μg/mL (S), 4 μg/mL (I), and ≥8 μg/mL (R) for C. parapsilosis and all 3 echinocandins. The new CBPs for anidulafungin and caspofungin and C. glabrata are ≤0.12 μg/mL (S), 0.25 μg/mL (I), and ≥0.5 μg/mL (R), whereas those for micafungin are ≤0.06 μg/mL (S), 0.12 μg/mL (I), and ≥0.25 μg/mL (R). Due to the lack of CBPs for any of the echinocandins and C. lusitaniae, the epidemiological cutoff values (ECVs) were used for this species to categorize the isolates as wild-type (WT; MIC ≤ECV) and non-WT (MIC >ECV), respectively, for anidulafungin (≤2 μg/mL/>2 μg/mL), caspofungin (≤1 μg/mL/>1 μg/mL), and micafungin (≤0.5 μg/mL/>0.5 μg/mL). CA ranged from 93.6% (caspofungin) to 99.6% (micafungin) with less than 1% very major or major errors. The YeastOne colorimetric method remains comparable to the CLSI BMD reference method for testing the susceptibility of Candida spp. to the echinocandins when using the new (lower) CBPs and ECVs. Further study using defined fks mutant strains of Candida is warranted. Copyright © 2012 Elsevier Inc. All rights

  19. Efficient extraction of intracellular reduced glutathione from fermentation broth of Saccharomyces cerevisiae by ethanol.

    Science.gov (United States)

    Xiong, Zhi-Qiang; Guo, Mei-Jin; Guo, Yuan-Xin; Chu, Ju; Zhuang, Ying-Ping; Zhang, Si-Liang

    2009-01-01

    Reduced glutathione (GSH) from fermentation broth of Saccharomyces cerevisiae was extracted with ethanol without disruption of the cells. The effects of ethanol concentration, extraction temperature and extraction time were assessed by using 2(3) full factorial designs (FFD). Preliminary studies showed that ethanol concentration had the most influence on GSH yield by ethanol extraction, based on the first order regression coefficients derived using MINITAB software, and an optimal ethanol concentration (25%, v/v) was obtained. However, compared to the conventional extraction technique (hot water extraction), there was no significant advantage in yield of GSH from yeast cells using ethanol extraction under these optimized conditions. But ethanol extraction has several advantages, such as lower energy consumption and lower protein concentration of extraction broth, which may reduce the complexity and cost of the purification process. Hence, ethanol extraction which does not disrupt yeast cells could be an inexpensive, simple and efficient alternative to conventional extraction techniques in the GSH industry.

  20. Incidence of Propionibacterium acnes in initially culture-negative thioglycollate broths

    DEFF Research Database (Denmark)

    Kvich, L.; Jensen, Peter Østrup; Justesen, U. S.

    2016-01-01

    The aim of this study was to prospectively investigate the incidence of Propionibacterium acnes in thioglycollate broths reported as culture-negative at the Department of Clinical Microbiology, Rigshospitalet, to evaluate whether 5 days of incubation was enough to find all relevant cases. Five....... After exclusion criteria were met, P. acnes was cultured from ten out of 151 patients (6.6%) in the infected group and from one out of 138 participants (0.7%) in the control group. This resulted in more findings of P. acnes in the infected group on day 14 than on day 5 (p 0.002). Furthermore, P. acnes...... was cultured more often from bone tissue and tissue surrounding foreign materials on day 14 than on day 5 (p 0.04). Clinical microbiology laboratories should consider incubating thioglycollate broths for at least 14 days to find all relevant cases of P. acnes, especially when it comes to bone tissue and tissue...

  1. Pilot microscreen separation of Sclerotium rolfsii biomass and broth. [Sclerotium rolfsii

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, W.L. (Oak Ridge National Lab., TN); Compere, A.L.; Cravens, J.B.; Erickson, P.R.

    1981-01-01

    Field production of scleroglucan biopolymer for micellular flooding near an injection well could eliminate two major polymer production costs, alcohol precipitation of polymer broth and resuspension of dry polymer in water. The use of microscreening could decrease these and another major polymer production cost, that of diatomaceous earth filtration. Bench and pilot tests using Rexnord 1, 6, and 21-..mu..m screens indicate that they provide efficient removal of gross solids from Sclerotium rolfsii culture broth partially diluted to viscosities suitable for field injection. Pilot centrifuge tests indicate that the microscreen backwash could be concentrated to a solid content of 2 to 3% as volatile suspended solids, suitable for animal feed or by-product use. Although polishing filtration is required to remove residual formation plugging constituents, substantial decreases in capital costs and operating energy appear attainable if microscreening is used. 3 figures, 3 tables.

  2. Submerged culture mycelium and broth of Grifola frondosa improve glycemic responses in diabetic rats.

    Science.gov (United States)

    Lo, Hui-Chen; Hsu, Tai-Hao; Chen, Ching-Yi

    2008-01-01

    Grifola frondosa, an edible fungus with a large fruiting body and overlapping caps, has been demonstrated to be a natural source of health-promoting substances, mainly due to its polysaccharides beta-glucan. By using male Wistar rats injected with saline (normal rats) or nicotinamide plus streptozotocin (diabetic rats), we investigated the effects of an orally ingested placebo (CON and STZ groups), culture mycelium (CGM and SGM groups), broth (CGB and SGB groups), and mycelium plus broth (CGX and SGX groups) of Grifola frondosa on glycemic responses. During the experimental period (from day 0 to day 15), the STZ group had significantly lower body weight compared to the CON group (one-way ANOVA, pGrifola frondosa have bioactivities for improving glycemic responses.

  3. Quantification of l-alanyl-l-glutamine in mammalian cell culture broth: Evaluation of different detectors.

    Science.gov (United States)

    Krömer, Jens O; Dietmair, Stefanie; Jacob, Shana S; Nielsen, Lars K

    2011-09-01

    l-Alanyl-l-glutamine (also known as Ala-Gln or GlutaMAX) is widely used as a stable l-glutamine source in cell culture for the production of biopharmaceuticals. System approaches for the optimization of production processes require the analysis of all major substrates and products. We have compared four alternative detection systems for l-alanyl-l-glutamine in culture broth. Matrix effects prevented the use of ultraviolet or evaporative light scattering detection. Fluorescence detection used in routine amino acid protocols is compatible with culture broth and has a broad linear dynamic range. Mass spectrometry has superior sensitivity and can be integrated into quantitative metabolomic workflows. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. MICROFILTRATION AND ULTRAFILTRATION OF Bacillus thuringiensis FERMENTATION BROTH: MEMBRANE PERFORMANCE AND SPORE-CRYSTAL RECOVERY APPROACHES

    OpenAIRE

    Marzban, R.; Saberi, F.; M.M.A. Shirazi

    2016-01-01

    Abstract Recovery of spores and crystals from the fermentation broth of Bacillus thuringiensis (Bt) was studied using the membrane separation technology. Four types of polymeric membranes, with different characteristics, in the range of microfiltration (MF) and ultrafiltration (UF) were used for evaluating their permeate flux and spore-crystal recovery capacity. Results indicated that both MF and UF membranes are effective for spore-crystal recovery. The hydrophobic MF membrane made of polyvi...

  5. Hydrogen peroxide and superoxide radical formation in anaerobic broth media exposed to atmospheric oxygen.

    Science.gov (United States)

    Carlsson, J; Nyberg, G; Wrethén, J

    1978-08-01

    Fourteen different broth media were autoclaved under anaerobic conditions and then exposed to atmospheric oxygen. The hydrogen peroxide and superoxide radical formation as well as the bactericidal effect of the media were studied. The rate of killing of Peptostreptococcus anaerobius VPI 4330-1 was high in media that rapidly autoxidized and accumulated hydrogen peroxide. In actinomyces broth (BBL), 50% of the cells were killed within 2 min, and in Brewer thioglycolate medium (Difco), 50% were killed within 11 min, whereas more than 50% of the cells survived for more than 2 h in Clausen medium (Oxoid), fluid thioglycolate medium (BBL), and thioglycolate medium without dextrose or indicator (Difco). Only media that contained phosphate and glucose had a tendency to accumulate hydrogen peroxide. A solution of phosphate and glucose autoxidized when it had been heated to 120 degrees C for at least 5 min and when the pH of the solution was higher than 6.5. Transitional metal ions catalyzed the autoxidation, but they were not necessary for the reaction to occur. Of the other substances heated in phosphate buffer, only alpha-hydroxycarbonyl compounds autoxidized with accumulation of hydrogen peroxide. Superoxide dismutase decreased the autoxidation rate of most of the broth media. This indicated that superoxide radicals were generated in these media.

  6. UV-Heat Treatments for the Control of Foodborne Microbial Pathogens in Chicken Broth

    Directory of Open Access Journals (Sweden)

    M. Gouma

    2015-01-01

    Full Text Available This investigation established the process criteria for using UV-C light and mild heat (UV-H treatment to inactivate 5-Log10 cycles (performance criterion of common foodborne pathogen populations, Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus, when inoculated in chicken broth. To define the target microorganism and the proper UV-H treatment conditions (including UV dose, treatment time, and temperature that would achieve the stated performance criterion, mathematical equations based on Geeraerd’s model were developed for each microorganism. For the sake of comparison, inactivation equations for heat treatments were also performed on the same chicken broth and for the same microorganisms. L. monocytogenes was the most UV-H resistant microorganism at all temperatures, requiring a UV dose between 6.10 J/mL (5.6 min and 2.26 J/mL (2.09 min to achieve 5-Log10 reductions. In comparison with UV treatments at room temperatures, the combination of UV and mild heat allowed both the UV dose and treatment time to be reduced by 30% and 63% at 55°C and 60°C, respectively. Compared to heat treatments, the UV-H process reduced the heating time for 5-Log10 reductions of all the investigated microorganisms in chicken broth from 20-fold to 2-fold when the operating temperature varied from 53 to 60°C.

  7. Characterization of dye decolorization in cell-free culture broth of Trametes versicolor CBR43.

    Science.gov (United States)

    Ryu, Hyun; Ryu, Hee Wook; Cho, Kyung Suk

    2016-09-23

    The dye decolorization rate in a cell-free culture broth of the white rot fungus Trametes versicolor CBR43 was studied, including the effects of inhibitors of NaCl, Zn(II), and Cd(II) on dye decolorization activity. The maximum rates of dye decolorization in cell-free culture broth were 1410, 44.7, 41.2, and 0.19 μmol L-1 min-1 for Acid Blue 62, Acid Black 175, Reactive Blue 4, and Acid Red 114, respectively. The inhibition effects of NaCl, Zn(II), and Cd(II) on dye decolorization were quantitatively compared using the half maximal inhibition concentration (IC50), which indicates the concentration of an inhibitor required for 50% inhibition. Based on IC50 values, dye decolorization in the cell-free culture broth of CBR43 was most potently inhibited by Cd(II), whereas the inhibitory effect of NaCl was relatively low. The dye decolorization rates and IC50 data can be used in the design and development of a dye-wastewater treatment process using T. versicolor CBR43 and its operating factors.

  8. Broth medium for the successful culture of the fish pathogen Piscirickettsia salmonis .

    Science.gov (United States)

    Yañez, A J; Valenzuela, K; Silva, H; Retamales, J; Romero, A; Enriquez, R; Figueroa, J; Claude, A; Gonzalez, J; Avendaño-Herrera, R; Carcamo, J G

    2012-01-24

    Piscirickettsiosis or salmonid rickettsial septicaemia (SRS) caused by Piscirickettsia salmonis constitutes one of the main problems in farmed salmonid and marine fishes. Since the first reports of the disease, it has been successfully isolated and maintained in eukaryotic cell--culture systems, but these systems are time-consuming, the media are costly, and eliminating heavily contaminated host cell debris is difficult. In this report, we describe a marine-based broth supplemented with L-cysteine, named AUSTRAL-SRS broth, that facilitates superior growth of P. salmonis strains. Strains reached an optical density of approximately 1.8 when absorbance was measured at 600 nm after 6 d incubation at 18°C. Several passages (n = 6) did not alter the culture kinetics. We report for the first time the purification of DNA, lipopolysaccharide (LPS) and whole membrane protein obtained from P. salmonis grown in this liquid medium, and thus provide a suitable platform to simplify the preparation of P. salmonis cells for genetic and serological studies. Moreover, the results of the cytopathic effect test showed that P. salmonis grown in AUSTRAL-SRS broth maintained their virulence properties, inducing apoptosis after 3 d. This makes the medium a good candidate for the successful growth of P. salmonis and an excellent basis for the development of low cost vaccines.

  9. MICROFILTRATION AND ULTRAFILTRATION OF Bacillus thuringiensis FERMENTATION BROTH: MEMBRANE PERFORMANCE AND SPORE-CRYSTAL RECOVERY APPROACHES

    Directory of Open Access Journals (Sweden)

    R. Marzban

    Full Text Available Abstract Recovery of spores and crystals from the fermentation broth of Bacillus thuringiensis (Bt was studied using the membrane separation technology. Four types of polymeric membranes, with different characteristics, in the range of microfiltration (MF and ultrafiltration (UF were used for evaluating their permeate flux and spore-crystal recovery capacity. Results indicated that both MF and UF membranes are effective for spore-crystal recovery. The hydrophobic MF membrane made of polyvinylidene fluoride (PVDF achieved a better performance compared to the one made with hydrophilic cellulose acetate (CA. Both had a 0.22 µm pore size, under the condition of an upper range of feed pressure. Also, with the increase of the feed flow rate, a higher flux was achieved for the PVDF membrane. A UF membrane made of polyethersulfone (PES polymer was also used effectively for spore/crystal recovery from the broth, but under a higher operating pressure. In the entire experiment, a 99.9% rejection factor was measured with the applied membranes for the spore/crystal in the fermentation broth.

  10. Determination of anti-staphylococcal activity of thymoquinone in combinations with antibiotics by checkerboard method using EVA capmat™ as a

    Directory of Open Access Journals (Sweden)

    Johana Rondevaldova

    2017-05-01

    Full Text Available Thymoquinone (Tq has been reported to potentiate the in vitro growth-inhibitory activity of some antibiotics especially against Staphylococcus aureus. However, it has been shown that Tq vapors can affect the results of susceptibility testing by standard broth microdilution method. Therefore, we made a comparative experiment with and without ethylene vinyl acetate cap mats (EVA capmat™ on microplates. The results showed significant differences in the minimum inhibitory concentration values and proved this capmat as an effective vapor barrier. Therefore further experiments focused on the in vitro anti-staphylococcal combinatory effect of Tq with oxacillin, penicillin, and tetracycline against various S. aureus strains have been performed by checkerboard method using EVA capmat™. The combined effect was evaluated according to the sum of fractional inhibitory concentrations (ΣFIC. Synergy was obtained for combination with oxacillin against 3 (ΣFIC 0.263–0.450, with penicillin against 1 (ΣFIC 0.466 and with tetracycline against 2 strains tested (ΣFIC 0.400–0.475. Our results confirm previous reports on the Tq enhancement of anti-staphylococcal activity of antibiotics. Moreover, this is the first report on Tq synergy with oxacillin and penicillin against S. aureus. Our experiments also showed that Tq vapors can affect evaluation of combined effect by checkerboard assay, whereas the use of EVA capmat™ can avoid this.

  11. [Comparative studies of fresh and seawater for the determination of total coliform and fecal coliform bacteria according to the European Economic Community guideline 76/160 (bathing water) by the use of the most-probable-number method with BRILA-MUG broth and differentiation according to the drinking water ordinance].

    Science.gov (United States)

    Havemeister, G; Aleksic, S; Bockemühl, J; Heinemeyer, E A; Müller, H E; Von Pritzbuer, E

    1991-05-01

    During the summer season of 1989 about 222 samples of bathing water (Northsea, Baltic Sea and inland waters) were investigated, i.e. 2 times 1998 dilution tubes (1501 positive) were tested. Results with BRILA-MUG and lactose-bouillon were compared and additional 97 samples were tested with one respectively three colonies by confirmative tests. -- The BRILA-MUG one-tube-test (gas, fluorescence and indol) has as expected larger numbers of total coliforms (GC) and faecal coliforms (FC) in comparison with corresponding numbers for E. coli and coliform bacteria according to German law for drinking water (TrinkwV). -- BRILA-MUG and lactose-bouillon with the same identification mode according to "TrinkwV" has corresponding results concerning E. coli and coliform bacteria. -- Following the identification mode according to "TrinkwV" the total coliforms (GC/gas in BRILA-MUG) depending on the origin proved 60-80% as coliform bacteria. Additional API-tests showed that the other bacteria are coliform bacteria too or bacteria which can be considered as indicators for water pollution. -- Faecal coliforms (FC/fluorescence and indol-positive) depending on the origin proved 70-90% as E. coli, if following the identification mode according to "TrinkwV". Using 3 instead of 1 colony per positive dilution tube for identification the positive results increased approximately by 9%. 15% of negative results with the identification mode according to "TrinkwV" proved as E. coli-positive with identification according to API-system, i.e. the corresponding rate of E. coli-positive tubes will therefore be higher than shown above. The BRILA-MUG one-tube-test in connection with the MPN-method can be used successfully to determine the number of total and faecal coliforms according to the EEC-directive for bathing waters. The test needs only a minimum of material and also a minimum of laboratory staff. Differences between this test and other more extensive tests with several biochemical

  12. Quality-control ranges for antimicrobial susceptibility testing by broth dilution of the Brachyspira hyodysenteriae type strain (ATCC 27164(T))

    DEFF Research Database (Denmark)

    Pringle, M.; Aarestrup, Frank Møller; Bergsjø, B.

    2006-01-01

    There are no approved standards for antimicrobial susceptibility testing of the fastidious spirochete Brachyspira hyodysenteriae. An interlaboratory study was performed to establish MIC quality control ranges for six antimicrobial agents for the type strain of B. hyodysenteriae using broth diluti...

  13. Comparison of chemical composition and antibacterial activity of Nigella sativa seed essential oils obtained by different extraction methods.

    Science.gov (United States)

    Kokoska, L; Havlik, J; Valterova, I; Sovova, H; Sajfrtova, M; Jankovska, I

    2008-12-01

    Nigella sativa L. seed essential oils obtained by hydrodistillation (HD), dry steam distillation (SD), steam distillation of crude oils obtained by solvent extraction (SE-SD), and supercritical fluid extraction (SFE-SD) were tested for their antibacterial activities, using the broth microdilution method and subsequently analyzed by gas chromatography and gas chromatography-mass spectrometry. The results showed that the essential oils tested differed markedly in their chemical compositions and antimicrobial activities. The oils obtained by HD and SD were dominated by p-cymene, whereas the major constituent identified in both volatile fractions obtained by SD of extracted oils was thymoquinone (ranging between 0.36 and 0.38 g/ml, whereas in oils obtained by HD and SD, it constituted only 0.03 and 0.05 g/ml, respectively). Both oils distilled directly from seeds showed lower antimicrobial activity (MICs > or = 256 and 32 microg/ml for HD and SD, respectively) than those obtained by SE-SD and SFE-SD (MICs > or = 4 microg/ml). All oil samples were significantly more active against gram-positive than against gram-negative bacteria. Thymoquinone exhibited potent growth-inhibiting activity against gram-positive bacteria, with MICs ranging from 8 to 64 microg/ml.

  14. Erinaceolactones A to C, from the culture broth of Hericium erinaceus.

    Science.gov (United States)

    Wu, Jing; Tokunaga, Taiki; Kondo, Mitsuru; Ishigami, Kota; Tokuyama, Shinji; Suzuki, Tomohiro; Choi, Jae-Hoon; Hirai, Hirofumi; Kawagishi, Hirokazu

    2015-01-23

    Three novel compounds, erinaceolactones A to C (1-3), and a known compound (4) were isolated from the culture broth of Hericium erinaceus. The planar structures of 1-3 were determined by the interpretation of spectroscopic data. The absolute configuration of 3 was determined by X-ray crystallography. Although compound 4 had been synthesized, it was isolated from a natural source for the first time. In the bioassay examining plant-growth regulatory activity of these compounds (1-4) and other components of the fungus (5-8), compounds 1, 2, and 4-8 suppressed the growth of lettuce.

  15. Detection of Burkholderia pseudomallei in Sputum using Selective Enrichment Broth and Ashdown's Medium at Kampong Cham Provincial Hospital, Cambodia.

    Science.gov (United States)

    Nhem, Somary; Letchford, Joanne; Meas, Chea; Thann, Sovanndeth; McLaughlin, James C; Baron, Ellen Jo; West, T Eoin

    2014-01-01

    Melioidosis, infection caused by Burkholderia pseudomallei, is increasingly reported in Cambodia. We hypothesized that implementation of an enhanced sputum testing protocol in a provincial hospital diagnostic microbiology laboratory would increase detection of B. pseudomallei. We tested 241 sputum specimens that were deemed acceptable for culture, comparing culture in selective enrichment broth followed by sub-culture on Ashdown's medium to standard culture methods. Two specimens (0.8%) were positive for B. pseudomallei using the enhanced protocol whereas one specimen (0.4%) was positive using standard methods. Given the low numbers of positive specimens, we could not conclusively determine the utility of the enhanced sputum testing protocol. However, the ramifications of identification of  B. pseudomallei are substantial, and the benefit of the enhanced testing protocol may be more apparent in patients selected based on risk factors and clinical presentation. Promoting clinician awareness of the infection and encouraging utilization of diagnostic microbiology services are also likely to be important factors in facilitating identification of melioidosis.

  16. 2,3-Butanediol recovery from fermentation broth by alcohol precipitation and vacuum distillation.

    Science.gov (United States)

    Jeon, Sangjun; Kim, Duk-Ki; Song, Hyohak; Lee, Hee Jong; Park, Sunghoon; Seung, Doyoung; Chang, Yong Keun

    2014-04-01

    This study presents a new and effective downstream process to recover 2,3-butanediol (2,3-BD) from fermentation broth which is produced by a recombinant Klebsiella pneumoniae strain. The ldhA-deficient K. pneumoniae strain yielded about 90 g/L of 2,3-BD, along with a number of by-products, such as organic acids and alcohols, in a 65 h fed-batch fermentation. The pH-adjusted cell-free fermentation broth was firstly concentrated until 2,3-BD reached around 500 g/L by vacuum evaporation at 50°C and 50 mbar vacuum pressure. The concentrated solution was further treated using light alcohols, including methanol, ethanol, and isopropanol, for the precipitation of organic acids and inorganic salts. Isopropanol showed the highest removal efficiency, in which 92.5% and 99.8% of organic acids and inorganic salts were precipitated, respectively. At a final step, a vacuum distillation process enabled the recovery of 76.2% of the treated 2,3-BD, with 96.1% purity, indicating that fermentatively produced 2,3-BD is effectively recovered by a simple alcohol precipitation and vacuum distillation. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. Lethal paralytic shellfish poisoning from consumption of green mussel broth, Western Samar, Philippines, August 2013.

    Science.gov (United States)

    Ching, Paola Katrina; Ramos, Ruth Alma; de los Reyes, Vikki Carr; Sucaldito, Ma Nemia; Tayag, Enrique

    2015-01-01

    In July 2013, the Philippines' Event-Based Surveillance & Response Unit received a paralytic shellfish poisoning (PSP) report from Tarangnan, Western Samar. A team from the Department of Health conducted an outbreak investigation to identify the implicated source and risk factors in coastal villages known for green mussel production and exportation. A case was defined as a previously well individual from Tarangan, Western Samar who developed gastrointestinal symptoms and any motor and/or sensory symptoms after consumption of shellfish from 29 June to 4 July 2013 in the absence of any known cause. The team reviewed medical records, conducted active case finding and a case-control study. Relatives of cases who died were interviewed. Sera and urine specimens, green mussel and seawater samples were tested for saxitoxin levels using high performance liquid chromatography. Thirty-one cases and two deaths were identified. Consumption of > 1 cup of green mussel broth was associated with being a case. Seawater sample was positive for Pyrodinium bahamense var. compressum and green mussel samples were positive for saxitoxin. Inspection revealed villagers practice open defecation and improper garbage disposal. This PSP outbreak was caused by the consumption of the green mussel broth contaminated by saxitoxin. As a result of this outbreak, dinoflagellate and saxitoxin surveillance was established, and since the outbreak, there have been no harmful algal blooms event or PSP case reported since. A "Save Cambatutay Bay" movement, focusing on proper waste disposal practice and clean-up drives has been mobilized.

  18. High pressure inactivation of Pseudomonas in black truffle - comparison with Pseudomonas fluorescens in tryptone soya broth

    Science.gov (United States)

    Ballestra, Patricia; Verret, Catherine; Cruz, Christian; Largeteau, Alain; Demazeau, Gerard; El Moueffak, Abdelhamid

    2010-03-01

    Pseudomonas is one of the most common genera in black Perigord truffle. Its inactivation by high pressure (100-500 MPa/10 min) applied on truffles at sub-zero or low temperatures was studied and compared with those of Pseudomonas fluorescens in tryptone soya broth. Pressurization of truffles at 300 MPa/4 °C reduced the bacterial count of Pseudomonas by 5.3 log cycles. Higher pressures of 400 or 500 MPa, at 4 °C or 20 °C, allowed us to slightly increase the level of destruction to the value of ca. 6.5 log cycles but did not permit us to completely inactivate Pseudomonas. The results showed a residual charge of about 10 CFU/g. Pressure-shift freezing of truffles, which consists in applying a pressure of 200 MPa/-18 °C for 10 min and then quickly releasing this pressure to induce freezing, reduced the population of Pseudomonas by 3.3 log cycles. The level of inactivation was higher than those obtained with conventional freezing. Endogenous Pseudomonas in truffle was shown to be more resistant to high pressure treatments than P. fluorescens used for inoculation of broths.

  19. Selenium intoxication with selenite broth resulting in acute renal failure and severe gastritis.

    Science.gov (United States)

    Kamble, P; Mohsin, N; Jha, A; Date, A; Upadhaya, A; Mohammad, E; Khalil, M; Pakkyara, A; Budruddin, M

    2009-01-01

    Selenium (Se) is an essential trace element in human and animal nutrition. It is also widely utilized in industrial processes. Reports of acute selenium toxicity in humans are rare. We report a case of a 23-year-old female who consumed about 100 mL of liquid selenite broth and presented with severe nausea, vomiting, abdominal pain, hematemesis and acute renal failure (ARF). The serum selenium level was significantly increased. Gastro-duodenoscopy revealed severe corrosive gastritis. Renal biopsy showed features of acute tubular necrosis (ATN), affecting primarily the proximal tubules. The patient was managed with gastric lavage, blood transfusions, infusion of fresh frozen plasma (FFP) and platelet concentrates and hemo-dialysis. The patient was discharged five weeks after admission and her renal functions recovered completely by eight weeks after admission. She continues to be on regular follow-up for any possible sequelae of mucosal corrosive damage. This case highlights a case of selenium intoxication from selenite broth resulting in ARF and corrosive gastritis. The recovery was complete.

  20. Selenium intoxication with selenite broth resulting in acute renal failure and severe gastritis

    Directory of Open Access Journals (Sweden)

    Kamble P

    2009-01-01

    Full Text Available Selenium (Se is an essential trace element in human and animal nutrition. It is also widely utilized in industrial processes. Reports of acute selenium toxicity in humans are rare. We report a case of a 23-year-old female who consumed about 100 mL of liquid selenite broth and presented with severe nausea, vomiting, abdominal pain, hematemesis and acute renal failure (ARF. The serum selenium level was significantly increased. Gastro-duodenoscopy revealed severe corrosive gastritis. Renal biopsy showed features of acute tubular necrosis (ATN, affecting primarily the proximal tubules. The patient was managed with gastric lavage, blood transfusions, infusion of fresh frozen plasma (FFP and platelet concentrates and hemo-dialysis. The patient was discharged five weeks after admission and her renal functions reco-vered completely by eight weeks after admission. She continues to be on regular follow-up for any possible sequelae of mucosal corrosive damage. This case highlights a case of selenium intoxication from selenite broth resulting in ARF and corrosive gastritis. The recovery was complete.

  1. Accuracy of different methods for susceptibility testing of gentamicin with KPC carbapenemase-producing Klebsiella pneumoniae.

    Science.gov (United States)

    Arena, Fabio; Giani, Tommaso; Vaggelli, Guendalina; Terenzi, Giovanni; Pecile, Patrizia; Rossolini, Gian Maria

    2015-02-01

    Performance of Vitek2, Etest, and TREK broth microdilution (BMD) panels was evaluated versus reference CLSI BMD for gentamicin susceptibility testing with 57 bloodstream isolates of KPC-producing Klebsiella pneumoniae. Compared with reference BMD, the Essential Agreement and Categorical Agreement for TREK panels, Vitek2, and Etest were 91.2%, 31.6%, and 61.4%, respectively, and 86%, 21%, and 52.6%, respectively. Four very major discrepancies occurred with Vitek2. In these 4 strains, gentamicin resistance was associated with the presence of an armA aminoglycoside resistance determinant. Copyright © 2015 Elsevier Inc. All rights reserved.

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

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    Luciano Mengatto

    2006-08-01

    Full Text Available A study was carried out to compare the performance of a commercial method (MGIT and four inexpensive drug susceptibility methods: nitrate reductase assay (NRA, microscopic observation drug susceptibility (MODS assay, MTT test, and broth microdilution method (BMM. A total of 64 clinical isolates of Mycobacterium tuberculosis were studied. The Lowenstein-Jensen proportion method (PM was used as gold standard. MGIT, NRA, MODS, and MTT results were available on an average of less than 10 days, whereas BMM results could be reported in about 20 days. Most of the evaluated tests showed excellent performance for isoniazid and rifampicin, with sensitivity and specificity values > 90%. With most of the assays, sensitivity for ethambutol was low (62-87% whereas for streptomycin, sensitivity values ranged from 84 to 100%; NRA-discrepancies were associated with cultures with a low proportion of EMB-resistant organisms while most discrepancies with quantitative tests (MMT and BMM were seen with isolates whose minimal inhibitory concentrations fell close the cutoff. MGIT is reliable but still expensive. NRA is the most inexpensive and easiest method to perform without changing the organization of the routine PM laboratory performance. While MODS, MTT, and BMM, have the disadvantage from the point of view of biosafety, they offer the possibility of detecting partial resistant strains. This study shows a very good level of agreement of the four low-cost methods compared to the PM for rapid detection of isoniazid, rifampicin and streptomycin resistance (Kappa values > 0.8; more standardization is needed for ethambutol.

  3. Producing cell-free culture broth of rhamnolipids as a cost-effective fungicide against plant pathogens.

    Science.gov (United States)

    Sha, Ruyi; Jiang, Lifang; Meng, Qin; Zhang, Guoliang; Song, Zhirong

    2012-08-01

    Biosurfactants of rhamnolipids have been enthusiastically investigated for substitutes of synthetic agrochemicals against plant pathogens. However, all such studies have been conducted on rhamnolipids with high purity which have limitations due to high costs. This paper focused on the applicability of rhamnolipid-containing cell-free culture broth. It was found that rhamnolipids in cell-free culture broth of Pseudomonas aeruginosa ZJU211 were largely composed of di-rhamnolipid and mono-rhamnolipid with the ratio varying with culture time. After 96 h of fermentation, the mass ratio of di-rhamnolipid over mono-rhamnolipid increased to 2.6:1. Crude rhamnolipids in a form of cell-free culture broth showed high antifungal activity against colony growth and biomass accumulation of seven plant pathogens comprising two Oomycetes, three Ascomycota and two Mucor spp. fungi, among which three plant pathogens were firstly reported in this paper showing inhibition to rhamnolipids. Particularly, rhamnolipids showed potent activity against two Oomycetes that acquire resistance to commercial compound of metalaxyal. Furthermore, di-rhamnolipid was elucidated to dominate the antifungal activity of crude rhamnolipids by in vitro studies. At last, the efficacy and safety of cell-free culture broth was preliminarily illustrated on plants in vivo. So cell-free culture broth as a crude rhamnolipid product could be served as a potential cost-effective and environmental-friendly fungicide in agriculture. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Energy-efficient recovery of butanol from model solutions and fermentation broth by adsorption.

    Science.gov (United States)

    Qureshi, N; Hughes, S; Maddox, I S; Cotta, M A

    2005-07-01

    This article discusses the separation of butanol from aqueous solutions and/or fermentation broth by adsorption. Butanol fermentation is also known as acetone butanol ethanol (ABE) or solvent fermentation. Adsorbents such as silicalite, resins (XAD-2, XAD-4, XAD-7, XAD-8, XAD-16), bone charcoal, activated charcoal, bonopore, and polyvinylpyridine have been studied. Use of silicalite appears to be the more attractive as it can be used to concentrate butanol from dilute solutions (5 to 790-810 g L(-1)) and results in complete desorption of butanol (or ABE). In addition, silicalite can be regenerated by heat treatment. The energy requirement for butanol recovery by adsorption-desorption processes has been calculated to be 1,948 kcal kg(-1) butanol as compared to 5,789 kcal kg(-1) butanol by steam stripping distillation. Other techniques such as gas stripping and pervaporation require 5,220 and 3,295 kcal kg(-1) butanol, respectively.

  5. Adherence of oral "Streptococcus milleri" cells to surfaces in broth cultures.

    Science.gov (United States)

    Eifuku-Koreeda, H; Yakushiji, T; Kitada, K; Inoue, M

    1991-01-01

    Cells of representative strains of oral "Streptococcus milleri" firmly adhered to glass surfaces when grown in glucose broths as well as in fructose and sucrose broths. Cellular adherence occurred on saliva-coated glass surfaces as well as uncoated surfaces, but the cells of only a few (6 of 69) tested adherent strains agglutinated upon the addition of human whole-saliva supernatant. Thus, the firm adherence of growing "S. milleri" cells is independent of sucrose and salivary macromolecules. Two macroscopic forms of cell adherence were observed: one was a coarse-granule type and one was a tiny-granule type covered with a thin homogeneous membranous material. Scanning electron microscopy revealed that, in both types, a stringy substance interconnected the cells and connected the cells to glass surfaces, with amorphous flocklike materials present in the intercellular space. Of the 154 tested strains, 128 were adherent, of which 90 were firmly and extensively (+2 or +3) adherent. Most strains of the serovars f/F, g, h, i, j, g-, and gj- were extensively adherent. Generally, cells of the more strongly adherent strains were more hydrophobic and spontaneously aggregating. However, there also existed a few hydrophilic and nonaggregating but extensively adherent strains. The presence of trypsin or pronase completely inhibited the adherence of some strains (mostly nonaggregating) but did not at all inhibit that of others (mostly aggregating). The adhering groups did not significantly differ in their cell surface hydrophobicities. Therefore, at least two factors, one proteinaceous and one nonproteinaceous, appear to be principally involved in the firm surface adherence of "S. milleri." Images PMID:1937769

  6. Synergistic Antimicrobial Combinations Inhibit and Inactivate Listeria monocytogenes in Neutral and Acidic Broth Systems.

    Science.gov (United States)

    Kozak, Sarah M; Margison, Kyle M; D'amico, Dennis J

    2017-08-01

    The use of antimicrobial compounds can be an effective approach to control Listeria monocytogenes in ready-to-eat foods, but it can also be limited by cost, restrictions on concentrations in foods, and potential changes to organoleptic properties. Combinatorial approaches that produce additive or synergistic effects allow for reductions in individual antimicrobial concentrations while achieving the same level of control. The present study determined the MIC and MBC of an antimicrobial compound when used alone or in binary combinations against L. monocytogenes in growth media adjusted to pH values 7.4 and 5.5 and characterized interactions as synergistic, additive, or antagonistic. Inhibitory and bactericidal concentrations were defined as changes in L. monocytogenes counts of ≤1.0 or ≥3.0 log CFU/mL compared with the starting inoculum, respectively. Individually, lauric arginate (LAE), hydrogen peroxide (HP), and ε-polylysine (EPL) inhibited L. monocytogenes growth at the lowest concentrations when applied alone in broth adjusted to pH 7.4. Similarly, LAE, EPL, and HP had the lowest MBCs in broth adjusted to both pH levels. The inhibitory efficacy of both caprylic acid and sodium caprylate (SC) increased at the lower pH, with reductions in MICs of >98%. In total, 35 and 19 additive or synergistic inhibitory and bactericidal combinations were identified at pH values 7.4 and 5.5, respectively. Combinations of acidified calcium sulfate with lactic acid (ACSL) and SC were among the most synergistic inhibitory groupings at both pH levels, whereas EPL+LAE were the most effective bactericides at pH 7.4. Combinations of SC with EPL or ACSL were also among the most effective bactericides at pH 5.5. These data serve as a foundation for developing more effective antimicrobial approaches for the control of L. monocytogenes in foods with different pH levels.

  7. Fermentation broth components influence droplet coalescence and hinder advanced biofuel recovery during fermentation.

    Science.gov (United States)

    Heeres, Arjan S; Schroën, Karin; Heijnen, Joseph J; van der Wielen, Luuk A M; Cuellar, Maria C

    2015-08-01

    Developments in synthetic biology enabled the microbial production of long chain hydrocarbons, which can be used as advanced biofuels in aviation or transportation. Currently, these fuels are not economically competitive due to their production costs. The current process offers room for improvement: by utilizing lignocellulosic feedstock, increasing microbial yields, and using cheaper process technology. Gravity separation is an example of the latter, for which droplet growth by coalescence is crucial. The aim of this study was to study the effect of fermentation broth components on droplet coalescence. Droplet coalescence was measured using two setups: a microfluidic chip and regular laboratory scale stirred vessel (2 L). Some fermentation broth components had a large impact on droplet coalescence. Especially components present in hydrolysed cellulosic biomass and mannoproteins from the yeast cell wall retard coalescence. To achieve a technically feasible gravity separation that can be integrated with the fermentation, the negative effects of these components on coalescence should be minimized. This could be achieved by redesign of the fermentation medium or adjusting the fermentation conditions, aiming to minimize the release of surface active components by the microorganisms. This way, another step can be made towards economically feasible advanced biofuel production. © 2015 The Authors. Biotechnology Journal published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. This is an open access article under the terms of the Creative Commons Attribution-Non-Commercial-NoDerivs Licence, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

  8. [Antimycoplasmic Activity of Fermentation Broth of Trichoderma harzianum Rifai F-180, an Organism Producing L-Lysine-α-Oxidase, an Antitumor and Antiviral Enzyme].

    Science.gov (United States)

    Smirnova, I P; Rakovskaya, I V

    2014-01-01

    A concentrate of the fermentation broth of Trichoderma harzianum Rifai F-180, an organism producing L-lysine-α-oxidase, an antitumor and antiviral enzyme, with the activity in the fermentation broth of 0.54-0.56 U/mI was recovered. The effect of the concentrate on the mycoplasmas growth was investigated for the first time. Two representatives of Mycoplasmafaceae, i.e. Mycoplasma hominis and Mycoplasma fermentans and one representative of Aholeplasmataceae. i. e. Aholeplasma laidlawii were used. It was shown that the fermentation broth inhibited the growth of Mycoplasma hominis after the preliminary exposure. The inhibition rate depended on the mycoplasma inoculation dose and the fermentation broth concentration.

  9. Thermal inactivation and sublethal injury kinetics of Salmonella enterica and Listeria monocytogenes in broth versus agar surface.

    Science.gov (United States)

    Wang, Xiang; Devlieghere, Frank; Geeraerd, Annemie; Uyttendaele, Mieke

    2017-02-21

    The objective of the present study was to compare the thermal inactivation and sublethal injury kinetics of Salmonella enterica and Listeria monocytogenes in broth (suspended cells) and on solid surface (agar-seeded cells). A 3-strain cocktail of S. enterica or L. monocytogenes inoculated in broth or on agar was subjected to heating in a water bath at various set temperatures (55.0, 57.5 and 60.0°C for S. enterica and 60.0, 62.5 and 65°C for L. monocytogenes). The occurrence of sublethally injured cells was determined by comparing enumerations on nonselective (TSAYE) and selective (XLD or ALOA) media. Results showed that the inactivation curves obtained from selective media were log-linear, and significant shoulders (pagar surface exhibited higher heat resistance than those in broth. For S. enterica, cell injury increased with the exposure time, no difference was observed when treated at temperatures from 55.0 to 60.0°C, while for L. monocytogenes, cell injury increased significantly with heating time and treatment temperature (from 60.0 to 65°C). Moreover, the degree of sublethal injury affected by thermal treatment in broth or on agar surface depended upon the target microorganism. Higher proportions of injured S. enterica cells were observed for treatment in broth than on agar surface, while the opposite was found for L. monocytogenes. The provided information may be used to assess the efficacy of thermal treatment processes on surfaces for inactivation of S. enterica and L. monocytogenes, and it provides insight into the sublethally injured survival state of S. enterica and L. monocytogenes treated in liquid or on solid food. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Assessment of caspofungin susceptibility of Candida glabrata by the Etest®, CLSI, and EUCAST methods, and detection of FKS1 and FKS2 mutations.

    Science.gov (United States)

    Bourgeois, N; Laurens, C; Bertout, S; Balard, Y; Krasteva, D; Rispail, P; Lachaud, L

    2014-07-01

    Candida glabrata has emerged as a major pathogen in invasive candidiasis in recent years. Currently, guidelines for invasive candidiasis treatment recommend fluconazole or an echinocandin as the first-line therapy. Nevertheless, the resistance of Candida glabrata to echinocandin is an emerging problem and has been partly associated with mutations in the FKS1 and FKS2 genes. The Etest® is an appropriate method for determining antifungal susceptibility in emergency routine diagnosis. In this work, we evaluated the reliability of the Etest® in comparison with the two reference broth microdilution methods, Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST), to assess the caspofungin resistance of 193 isolates of Candida glabrata. The interpretation of minimum inhibitory concentration (MIC) values was also discussed according to different breakpoints. Moreover, FKS1 and FKS2 mutations were investigated for isolates with high MICs. Our results showed that the MIC50 value was similar to the MIC90 value for each method. The Etest® method showed the lowest MIC values, whereas EUCAST presented the highest. Categorical agreement between the Etest® and CLSI methods was 100 % and 36 % using the breakpoints proposed by Arendrup et al. (Antimicrob Agents Chemother 56(7):3965-3968, 2012) and Pfaller et al. (Int J Antimicrob Agents 38(1):65-69, 2011), respectively. Two isolates showed high MIC values with the three methods and both presented FKS2 mutations. A novel FKS2 mutation was also reported for one isolate. Future epidemiological studies should also evaluate the reliability of the Etest® to detect echinocandin resistance, as it remains a routine method.

  11. Ultrafiltration Lactic Acid Bacteria (LAB in mung Beans Broth by Mixed LAB Culture

    Directory of Open Access Journals (Sweden)

    Aspiyanto Aspiyanto

    2014-06-01

    Full Text Available Increasing Lactic Acid Bacteria (LAB concentration in fermented broth of mung beans by mixed culture of Lactobacillus sp. and Streptococcus thermophillus through ultrafiltration (UF (20,000 MWCO at flow rate of ~8.87 L/min, room temperature and pressure 5 and 7 bars for 0, 30, 60, 90 and 120 minutes was performed. The results showed that pressure and time affected on UF performance, total solids, total protein and total number of LAB. Optimal time at pressure 5 bar was reached 60 minutes with flux 11.94 L/m2.hour, total solids 13.9423%, total protein 8.95%, total LAB 6.18 log CFU/mL, Robs of total solids 3.45%, total protein  58.67%, LAB 100% and DC 1.38 folds. The best time at 7 bar was reached 30 minutes with flux 16.16 L/m2.hour, total solids 12.2879%, total protein 4.41%, total LAB 6.04 Log CFU/mL, Robs of total solids 11.98%, total protein 45.76%, LAB 99.5 and DC 1.16 folds.

  12. The influences of fish infusion broth on the biogenic amines formation by lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Esmeray Küley

    2013-01-01

    Full Text Available The influences of fish infusion decarboxylase broth (IDB on biogenic amines (BA formation by lactic acid bacteria (LAB were investigated. BA productions by single LAB strains were tested in five different fish (anchovy, mackerel, white shark, sardine and gilthead seabream IDB. The result of the study showed that significant differences in ammonia (AMN and BA production were observed among the LAB strains in fish IDB (p < 0.05. The highest AMN and TMA production by LAB strains were observed for white shark IDB. The all tested bacteria had decarboxylation activity in fish IDB. The uppermost accumulated amines by LAB strains were tyramine (TYM, dopamine, serotonin and spermidine. The maximum histamine production was observed in sardine (101.69 mg/L and mackerel (100.84 mg/L IDB by Leuconostoc mesenteroides subsp. cremoris and Pediococcus acidophilus, respectively. Lactobacillus delbrueckii subsp. lactis and Pediococcus acidophilus had a high TYM producing capability (2943 mg/L and 1157 mg/L in sardine IDB.

  13. Morphological engineering of Streptomyces hygroscopicus var. geldanus: regulation of pellet morphology through manipulation of broth viscosity.

    Science.gov (United States)

    O'Cleirigh, C; Casey, J T; Walsh, P K; O'Shea, D G

    2005-08-01

    Actinomycetes, especially members of the genus Streptomyces, are responsible for producing the majority of known antibiotics. The production of antibiotics by filamentous organisms is often dependent on the morphology and size distribution of the pellet population within the culture. Particle interaction and subsequent pellet formation are primarily dependent on the rate of collision of particles in culture, which is in turn, a function of fluid turbulence. The microbial polysaccharide xanthan gum was used to artificially regulate the apparent viscosity (mu(a)) of S. hygroscopicus fermentation broths with the aim of controlling particle interaction, aggregation and hence pellet formation. An increase in both pellet count and biomass concentration from approximately 2,000 to 8,000 pellets ml(-1) and 0.9-2.1 g l(-1) dry weight of biomass, as well a decrease in the mean pellet volume from 0.014 to 0.004 mm(3) was observed in cultures supplemented with 3 g l(-1) xanthan gum. The addition of xanthan gum significantly alters fluid rheology by increasing the mu(a). Counter-intuitively, an increase in the mu(a) within the experimental range examined resulted in an increase in the rate of gas-liquid mass transfer. This was attributed to the predominantly diffusive nature of oxygen transfer in shake flask cultures.

  14. Compounds in a particular production lot of tryptic soy broth inhibit Staphylococcus aureus cell growth.

    Science.gov (United States)

    Ishii, Masaki; Matsumoto, Yasuhiko; Sekimizu, Kazuhisa

    2015-06-01

    Staphylococcus aureus Newman strain and several methicillin-resistant S. aureus (MRSA) clinical isolates were grown on agar plates prepared with conventional lots of tryptic soy broth (TSB). Cell growth of these strains was inhibited on agar plates containing TSB of a particular product lot (lot A), whereas the cell growth of S. aureus RN4220 strain and several other MRSA clinical isolates was not inhibited. The cell growth of a strain of S. epidermidis was also inhibited on agar plates containing TSB of lot A, whereas the cell growth of Bacillus subtilis, Lactococcus lactis, Klebsiella pneumonia, Salmonella enterica, Serratia marcescens, Pseudomonas aeruginosa, and Escherichia coli was not inhibited. Although cell growth of the Newman strain was inhibited on agar plates containing TSB of lot A that was autoclaved in stainless steel or glass containers, cell growth inhibition was not observed when the medium was autoclaved in polypropylene containers. Compounds that inhibited the cell growth of the Newman strain were extracted from a polypropylene tube that was preincubated with liquid medium prepared from TSB of lot A. These findings suggest that polypropylene-binding compounds in TSB of lot A inhibited the cell growth of S. aureus Newman strain, some MRSA clinical isolates, and S. epidermidis.

  15. Commercial Lysogeny Broth culture media and oxidative stress: a cautious tale.

    Science.gov (United States)

    Ezraty, Benjamin; Henry, Camille; Hérisse, Marion; Denamur, Erick; Barras, Frédéric

    2014-09-01

    Lysogeny Broth (LB), most often misnamed Luria-Bertani medium, ranks among the most commonly used growth media in microbiology. Surprisingly, we observed that oxidative levels vary with the commercial origin of the LB ready to use powder. Indeed, growth on solid media of Escherichia coli and Salmonella derivatives lacking antioxidative stress defenses, such as oxyR mutant devoid of the H2O2-sensing transcriptional activator or Hpx(-) strains lacking catalases and peroxidases, exhibit different phenotypes on LB-Sigma or LB-Difco. Using gene fusion and exogenously added catalase, we found that LB-Sigma contains higher levels of H2O2 than LB-Difco. Also we observed differences in population counts of 82 clinical and environmental isolates of E. coli, depending on the LB used. Further investigations revealed a significant influence of the commercial origin of agar as well. Besides being a warning to the wide population of LB users, our observations provide researchers in the oxidative stress field with a tool to appreciate the severity of mutations in antioxidative stress defenses. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Synergistic interactions between cefalexin and kanamycin in Mueller-Hinton broth medium and in milk.

    Science.gov (United States)

    Ganière, J P; Denuault, L

    2009-07-01

    This study investigated the in vitro bactericidal activity of an intramammary drug product by comparing the kill kinetics of cefalexin and kanamycin, alone and in fixed ratio combination, against Streptococcus uberis, Staphylococcus aureus and Escherichia coli strains isolated from field cases of bovine mastitis. The effect of milk as a diluent on the rate of bacterial killing was also assessed. Antibacterial kill kinetics was determined against each bacterial strain in Mueller-Hinton broth (MHB) and in milk. In MHB, the fixed cefalexin : kanamycin combination (1.5 : 1 w/w) exhibited a clear synergistic bactericidal activity against the strains tested. The combination also showed an enhanced killing activity in milk, as compared to either agent alone. The data show the occurrence of synergistic interactions between cefalexin and kanamycin, resulting in a faster and enhanced bactericidal activity against major mastitis pathogens. The study demonstrated that the combination exhibited a larger and faster rate of kill of S. aureus, S. uberis and E. coli compared to either cefalexin or kanamycin alone, while using a lower total amount of antibiotic. Synergistic and additive effects were also observed when milk was used as a medium. The results support the use of this combination of narrow spectrum antibiotics to treat clinical mastitis via the intramammary route and provide data on its killing kinetics.

  17. Pre-clinical development of antifungal susceptibility test methods for the testing of the novel antifungal agent E1210 versus Candida: comparison of CLSI and European Committee on Antimicrobial Susceptibility Testing methods.

    Science.gov (United States)

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

    2011-11-01

    To compare European Committee on Antimicrobial Susceptibility Testing (EUCAST) and CLSI broth microdilution (BMD) methods for testing the novel antifungal E1210 against a recent collection of 102 clinical isolates of Candida spp. Candida isolates (102) were tested by CLSI and EUCAST methods; 21 Candida albicans, 20 Candida glabrata, 25 Candida parapsilosis, 24 Candida tropicalis and 12 Candida krusei, including echinocandin- and azole-resistant isolates. CLSI and EUCAST MIC endpoints of 50% and 100% inhibition were determined using visual reading at 24 and 48 h of incubation and spectrophotometric reading at 24 h of incubation, respectively. E1210 CLSI MIC results ranged from ≤0.008 to only 1 mg/L (excluding C. krusei) depending on species, duration of incubation and endpoint criteria (EC). E1210 was not active against C. krusei (MIC(50) >16 mg/L). Overall essential agreement (EA; ±2 doubling dilutions) between the 24 and 48 h CLSI readings was 100% and 97.6% using the 50% and 100% inhibition EC, respectively. Slightly more trailing growth at 48 h was observed with the 100% inhibition EC. Comparison of the 50% and 100% endpoints at 24 h of incubation showed an overall EA of 100%. Comparison of CLSI and EUCAST read at 24 h of incubation and either 50% or 100% inhibition revealed an EA of 97.8% using the 50% inhibition EC and 88.9% using the 100% inhibition EC. E1210 was found to have potent in vitro activity against Candida spp. when tested by both CLSI and EUCAST BMD methods, with the highest overall EA (97.8%) obtained when E1210 MIC results were read after 24 h of incubation using a partial inhibition EC.

  18. Ultra scale-down prediction using microwell technology of the industrial scale clarification characteristics by centrifugation of mammalian cell broths.

    Science.gov (United States)

    Tait, A S; Aucamp, J P; Bugeon, A; Hoare, M

    2009-10-01

    This article describes how a combination of an ultra scale-down (USD) shear device feeding a microwell centrifugation plate may be used to provide a prediction of how mammalian cell broth will clarify at scale. In particular a method is described that is inherently adaptable to a robotic platform and may be used to predict how the flow rate and capacity (equivalent settling area) of a centrifuge and the choice of feed zone configuration may affect the solids carry over in the supernatant. This is an important consideration as the extent of solids carry over will determine the required size and lifetime of a subsequent filtration stage or the passage of fine particulates and colloidal material affecting the performance and lifetime of chromatography stages. The extent of solids removal observed in individual wells of a microwell plate during centrifugation is shown to correlate with the vertical and horizontal location of the well on the plate. Geometric adjustments to the evaluation of the equivalent settling area of individual wells (Sigma(M)) results in an improved prediction of solids removal as a function of centrifuge capacity. The USD centrifuge settling characteristics need to be as for a range of equivalent flow rates as may be experienced at an industrial scale for a machine of different shear characteristics in the entry feed zone. This was shown to be achievable with two microwell-plate based measurements and the use of varying fill volumes in the microwells to allow the rapid study of a fivefold range of equivalent flow rates (i.e., at full scale for a particular industrial centrifuge) and the effect of a range of feed configurations. The microwell based USD method was used to examine the recovery of CHO-S cells, prepared in a 5 L reactor, at different points of growth and for different levels of exposure to shear post reactor. The combination of particle size distribution measurements of the cells before and after shear and the effect of shear on the

  19. Ultra scale-down approaches for clarification of mammalian cell culture broths in disc-stack centrifuges.

    Science.gov (United States)

    Zaman, Ferhana; Allan, Corey M; Ho, Sa V

    2009-01-01

    Ultra-scale down (USD) methodology developed by University College London for cell broth clarification with industrial centrifuges was applied to two common cell lines (NS0 and GS-CHO) expressing various therapeutic monoclonal antibodies. A number of centrifuges at various scales were used with shear devices operating either by high speed rotation or flow-through narrow channels. The USD methodology was found effective in accounting for both gravitational and shear effects on clarification performance with three continuous centrifuges at pilot and manufacturing scales. Different shear responses were observed with the two different cell lines and even with the same cell line expressing different products. Separate particle size analysis of the treated broths seems consistent with the shear results. Filterability of the centrifuged solutions was also evaluated to assess the utility of the USD approach for this part of the clarification operation. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.

  20. Listeria monocytogenes efficiently invades caco-2 cells after low-temperature storage in broth and on deli meat

    DEFF Research Database (Denmark)

    Larsen, Marianne Halberg; Koch, Anette Granly; Ingmer, Hanne

    2010-01-01

    The objective of this study was to investigate how various growth conditions influence the virulence of Listeria monocytogenes monitored by its ability to invade the epithelial cell lines Caco-2 and INT-407. The growth conditions examined were modified atmosphere-packaged deli meat and brain heart...... infusion broth (BHI) with and without salt. Five strains of L. monocytogenes were selected to investigate their invasiveness and all strains invaded Caco-2 cells at higher levels than INT-407 cells. Further, the clinical strains (3443 and 3734) were more invasive (p ... to invade Caco-2 cells was compared after growth on a fermented sausage and on cured cooked ham to that of bacteria grown in BHI broth supplemented with salt. Samples were stored under chilling conditions for up to 4 weeks. The results showed no difference (p > 0.05) in invasiveness after 7 days at 10...

  1. Identification and Differentiation of Clinically Relevant Mycobacterium Species Directly from Acid-Fast Bacillus-Positive Culture Broth

    OpenAIRE

    Li, Haijing; Turhan, Vedat; Chokhani, Laxmi; Stratton, Charles W.; Dunbar, Sherry A.; Tang, Yi-Wei

    2009-01-01

    Mycobacterium species cause a variety of clinical diseases, some of which may be species specific. Therefore, it is clinically desirable to rapidly identify and differentiate mycobacterial isolates to the species level. We developed a rapid and high-throughput system, MycoID, to identify Mycobacterium species directly from acid-fast bacillus (AFB)-positive mycobacterial culture broth. The MycoID system incorporated broad-range PCR followed by suspension array hybridization to identify 17 clin...

  2. Extraction of natural red colorants from the fermented broth of Penicillium purpurogenum using aqueous two-phase polymer systems.

    Science.gov (United States)

    Santos-Ebinuma, Valéria Carvalho; Lopes, André Moreni; Pessoa, Adalberto; Teixeira, Maria Francisca Simas

    2015-01-01

    Safety concerns related to the increasing and widespread application of synthetic coloring agents have increased the demand for natural colorants. Fungi have been employed in the production of novel and safer colorants. In order to obtain the colorants from fermented broth, suitable extraction systems must be developed. Aqueous two-phase polymer systems (ATPPS) offer a favorable chemical environment and provide a promising alternative for extracting and solubilizing these molecules. The aim of this study was to investigate the partitioning of red colorants from the fermented broth of Penicillium purpurogenum using an ATPPS composed of poly(ethylene glycol) (PEG) and sodium polyacrylate (NaPA). Red colorants partitioned preferentially to the top (PEG-rich phase). In systems composed of PEG 6,000 g/mol/NaPA 8,000 g/mol, optimum colorant partition coefficient (KC ) was obtained in the presence of NaCl 0.1 M (KC  = 10.30) while the PEG 10,000 g/mol/NaPA 8,000 g/mol system in the presence of Na2 SO4 0.5 M showed the highest KC (14.78). For both polymers, the mass balance (%MB) and yield in the PEG phase (%ηTOP ) were close to 100 and 79%, respectively. The protein selectivity in all conditions evaluated ranged from 2.0-3.0, which shows a suitable separation of the red colorants and proteins present in the fermented broth. The results suggest that the partitioning of the red colorants is dependent on both the PEG molecular size and salt type. Furthermore, the results obtained support the potential application of ATPPS as the first step of a purification process to recover colorants from fermented broth of microorganisms. © 2015 American Institute of Chemical Engineers.

  3. Submerged-Culture Mycelia and Broth of the Maitake Medicinal Mushroom Grifola frondosa (Higher Basidiomycetes) Alleviate Type 2 Diabetes-Induced Alterations in Immunocytic Function.

    Science.gov (United States)

    Chen, Ya-Hui; Lee, Chien-Hsing; Hsu, Tai-Hao; Lo, Hui-Chen

    2015-01-01

    Type 2 Diabetes mellitus (T2DM), a disease with impaired glucose, protein and lipid metabolism, low-grade chronic inflammation, and immune dysfunction, is a global public health crisis. We previously demonstrated that Grifola frondosa has bioactivities in improving glycemic responses in diabetic rats. Herein, we investigated the immunomodulatory effects of the submerged-culture mycelia and broth of G. frondosa on the peripheral blood cells (PBL) and splenocytes. Male Wistar rats were administered with saline (normal rats) or streptozotocin plus nicotinamide (T2DM rats) and were intragastrically administered with placebo, fermented mycelia, broth, or mycelia plus broth (1 g kg-1 day-1) for two weeks. In normal rats, ingestion of mycelia significantly decreased monocytes and ingestion of mycelia and broth significantly decreased the productions of interferon (IFN)-γ and interleukin (IL)-4 from the PBL and splenocytes. In T2DM rats, ingestion of mycelia, broth, and mycelia plus broth significantly alleviated the increases in 2 h postprandial blood glucose and the productions of IFN-γ from the T-leukocytes, IL-4, and IL-6 from the monocytes and IL-4 from the T-splenocytes, as well as significantly improved the productions of tumor-necrosis factor-α from the macrophages. In conclusion, submerged-culture mycelia and broth of G. frondosa may decrease cell-medicated immunity in normal rats and improve hyperglycemia and diabetes-induced alterations in cell-medicated and innate immunities in T2DM rats.

  4. An investigation of vtx2bacteriophage transduction to different Escherichia coli patho-groups in food matrices and nutrient broth.

    Science.gov (United States)

    Nyambe, Sepo; Burgess, Catherine; Whyte, Paul; Bolton, Declan

    2017-12-01

    This study investigated bacteriophage (phage) mediated transfer of the vtx 2 gene from a donor Escherichia coli (C600φ3538(Δvtx 2 ::cat)) to enteropathogenic (EPEC), enterotoxigenic (ETEC), enteroaggregative (EAEC), enteroinvasive (EIEC) and diffusely adherent (DAEC) E. coli strains in LB broth, milk, ground beef and lettuce. Two bacterial concentrations for both the E. coli donor and recipient strains, 3 and 5 log 10  CFU/ml (LB broth and milk)/g (beef) or/cm 2 (lettuce), were used. When transductants were obtained, the location of insertion of the phage (insertion sites wrbA, yehA, sbcB, yecE and/or Z2577) in the E. coli chromosome was investigated by PCR. The vtx 2 gene was readily transferred to EAEC O104:H4 (E99518) in all matrices and inserted into the chromosome at the sbcB locus. At higher cell concentrations, transductants were also obtained with ETEC E4683, ETEC E8057 (insertion site unknown) and DAEC O75:H- E66438 (insertion site unknown) in LB broth and milk. It was concluded that the vtx 2 gene may be transferred by bacteriophage to different E. coli pathotypes in laboratory and food matrices, resulting in the spread of the vtx 2 gene and the emergence of novel foodborne pathogens. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Effect of a novel steroid (PM-9) on the inhibition of 5alpha-reductase present in Penicillium crustosum broths.

    Science.gov (United States)

    Flores, Eugenio; Cabeza, Marisa; Quiroz, Alexandra; Bratoeff, Eugene; García, Genoveva; Ramírez, Elena

    2003-03-01

    The conversion of testosterone (T) to 5alpha-dihydrotestosterone (DHT) has been demonstrated in Penicillium crustosum broth obtained from fermented pistachios, lemons and corn tortillas. Furthermore, the presence of 5alpha-reductase enzyme, which is responsible for this conversion, has been established by electrophoretical techniques in these cultures.5alpha-Reductase enzyme is also present in animal and human androgen-dependent tissues as well as in prostate and seminal vesicles. The increase of the conversion of T to DHT in prostate gland, has been related to some illnesses such as benign prostate hyperplasia and prostate cancer. Furthermore, treatment with 5alpha-reductase inhibitors such as finasteride reduces the prostate growth. These data have stimulated research for the synthesis of new molecules with antiandrogenic activity, whose biological effect needs to be demonstrated. The purpose of this study is to determine the inhibition pattern of 5alpha-reductase in P. crustosum by finasteride and the new steroidal compound PM-9. K(m) and V(max) values for T, were determined in the broths by Lineweaver-Burk plots using different testosterone concentrations. The inhibition pattern of finasteride and PM-9 was also determined by Lineweaver-Burk using different concentrations of T and inhibitors. Results show that finasteride and PM-9 inhibit 5alpha-reductase present in the broth in a competitive manner.

  6. Combination of Origanum vulgare L. essential oil and lactic acid to inhibit Staphylococcus aureus in meat broth and meat model

    Directory of Open Access Journals (Sweden)

    Jefferson C. de Barros

    2012-09-01

    Full Text Available This study assessed the occurrence of an enhancing inhibitory effect of the combined application of Origanum vulgare L. essential oil and lactic acid against Staphylococcus aureus by the determination of Fractional Inhibitory Concentration (FIC index and cell viability in meat broth and meat model. Minimum Inhibitory Concentration (MIC and Minimum Bactericidal Concentration (MBC of the oil was 0.6 and 1.25 µL.mL-1, respectively. Lactic acid showed MIC and MBC of 2.5 and 5µL.mL-1, respectively. FIC indices of the combined application of the oil and lactic acid were 0.5 showing a synergic interaction. The essential oil and lactic acid showed similar (p>0.05 anti-S. aureus effect in meat broth over 96 h of exposure. Treatment with essential oil or lactic acid presented a smaller anti-staphylococcal effect in meat in comparison to meat broth. No significant difference (p>0.05 was found for the microbial counts in meat treated with each antimicrobial alone or in mixture. These results could arise as an interesting approach for the improvement of food preservation using more natural procedures, considering the current demand of consumer and sensory quality of foods.

  7. Radiation sensitivity of poliovirus, a model for norovirus, inoculated in oyster ( Crassostrea gigas) and culture broth under different conditions

    Science.gov (United States)

    Jung, Pil-Mun; Park, Jae Seok; Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo; Baek, Min; Chung, Young-Jin; Lee, Ju-Woon

    2009-07-01

    Poliovirus is a recognized surrogate for norovirus, pathogen in water and food, due to the structural and genetic similarity. Although radiation sensitivity of poliovirus in water or media had been reported, there has been no research in food model such as shellfish. In this study, oyster ( Crassostrea gigas) was incubated in artificial seawater contaminated with poliovirus, and thus radiation sensitivity of poliovirus was determined in inoculated oyster. The effects of ionizing radiation on the sensitivity of poliovirus were also evaluated under different conditions such as pH (4-7) and salt concentration (1-15%) in culture broth, and temperature during irradiation. The D10 value of poliovirus in PBS buffer, virus culture broth and oyster was determined to 0.46, 2.84 and 2.94 kGy, respectively. The initial plaque forming unit (PFU) of poliovirus in culture broth was slightly decreased as the decrease of pH and the increase of salt concentration, but radiation sensitivity was not affected by pH and salt contents. However, radiation resistance of poliovirus was increased at frozen state. These results provide the basic information for the inactivation of pathogenic virus in foods by using irradiation.

  8. Radiation sensitivity of poliovirus, a model for norovirus, inoculated in oyster (Crassostrea gigas) and culture broth under different conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Pil-Mun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Park, Jae Seok [Korea Food and Drug Administration, Seoul 122-704 (Korea, Republic of); Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Baek, Min [Atomic Energy Policy Division, Ministry of Education, Science and Technology, Gwacheon 427-715 (Korea, Republic of); Chung, Young-Jin [Department of Food and Nutrition, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Ju-Woon [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2009-07-15

    Poliovirus is a recognized surrogate for norovirus, pathogen in water and food, due to the structural and genetic similarity. Although radiation sensitivity of poliovirus in water or media had been reported, there has been no research in food model such as shellfish. In this study, oyster (Crassostrea gigas) was incubated in artificial seawater contaminated with poliovirus, and thus radiation sensitivity of poliovirus was determined in inoculated oyster. The effects of ionizing radiation on the sensitivity of poliovirus were also evaluated under different conditions such as pH (4-7) and salt concentration (1-15%) in culture broth, and temperature during irradiation. The D{sub 10} value of poliovirus in PBS buffer, virus culture broth and oyster was determined to 0.46, 2.84 and 2.94 kGy, respectively. The initial plaque forming unit (PFU) of poliovirus in culture broth was slightly decreased as the decrease of pH and the increase of salt concentration, but radiation sensitivity was not affected by pH and salt contents. However, radiation resistance of poliovirus was increased at frozen state. These results provide the basic information for the inactivation of pathogenic virus in foods by using irradiation.

  9. Colistin and tigecycline resistance in carbapenemase-producing Gram-negative bacteria: emerging resistance mechanisms and detection methods.

    Science.gov (United States)

    Osei Sekyere, J; Govinden, U; Bester, L A; Essack, S Y

    2016-09-01

    A literature review was undertaken to ascertain the molecular basis for tigecycline and colistin resistance mechanisms and the experimental basis for the detection and delineation of this resistance particularly in carbapenemase-producing Gram-negative bacteria. Pubmed, Google Scholar and Science Direct were searched with the keywords colistin, tigecycline, resistance mechanisms and detection methods. Trans-complementation and comparative MIC studies, mass spectrometry, chromatography, spectrofluorometry, PCR, qRT-PCR and whole genome sequencing (WGS) were commonly used to determine tigecycline and colistin resistance mechanisms, specifically modifications in the structural and regulatory efflux (acrAB, OqxAB, kpgABC adeABC-FGH-IJK, mexAB-XY-oprJM and soxS, rarA robA, ramRAB marRABC, adeLRS, mexRZ and nfxb) and lipid A (pmrHFIJFKLM, lpxA, lpxC lpxD and mgrB, pmrAB, phoPQ,) genes respectively. Mutations in the ribosomal 16S rRNA operon rrnBC, also yielded resistance to tigecycline through target site modifications. The mcr-1 gene conferring resistance to colistin was identified via WGS, trans-complementation and a murine thigh infection model studies. Common detection methods are mainly antibiotic sensitivity testing with broth microdilution while molecular identification tools are mostly PCR and WGS. Spectrofluorometry, MALDI-TOF MS, micro-array and real-time multiplex PCR hold much promise for the future as new detection tools. © 2016 The Society for Applied Microbiology.

  10. Activity of MK-3118, a new oral glucan synthase inhibitor, tested against Candida spp. by two international methods (CLSI and EUCAST).

    Science.gov (United States)

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

    2013-04-01

    To evaluate the activity of the orally bioavailable enfumafungin derivative MK-3118 and comparator antifungal agents tested against a collection of 113 clinical isolates of Candida spp. using CLSI and EUCAST broth microdilution (BMD) methods. Candida spp. isolates (n=113) were tested by CLSI and EUCAST methods. The collection contained 29 Candida albicans, 29 Candida glabrata, 21 Candida tropicalis, 15 Candida parapsilosis and 19 Candida krusei, including azole- and echinocandin-resistant isolates. CLSI and EUCAST MIC endpoints of 50% and 100% inhibition were determined using visual reading at 24 and 48 h of incubation and spectrophotometric reading at 24 h of incubation, respectively. MK-3118 CLSI MIC results ranged from 0.06 to 16 mg/L depending on species, duration of incubation and endpoint criteria (EC) used. Comparison of CLSI and EUCAST following 24 h of incubation and either 50% or 100% inhibition revealed an essential agreement (EA; ± 2 doubling dilutions) of 99.1% using the 50% inhibition EC and 93.2% using the 100% inhibition EC. MK-3118 (24 h of incubation and 50% EC) was active against all the species tested and displayed similar potency to caspofungin (using CLSI BMD) against C. albicans (MIC90, 1 and 2 mg/L, respectively), C. tropicalis (1 and 1 mg/L, respectively), C. parapsilosis (0.5 and 0.5 mg/L, respectively) and C. krusei (2 and 1 mg/L, respectively), but was 8-fold more potent than caspofungin against C. glabrata strains (MIC90, 2 and 16 mg/L, respectively). MK-3118 was active against fluconazole-resistant strains as well as caspofungin-resistant strains with documented fks mutations. MK-3118 was documented to have potent in vitro activity against Candida spp. when tested by both CLSI and EUCAST BMD methods, with the highest overall EA (99.1%) obtained when MK-3118 MIC results were read after 24 h of incubation using a partial inhibition EC (50%).

  11. Effectiveness of the antimicrobial removal device, BACTEC 16B medium, and thiol broth in neutralizing antibacterial activities of imipenem, norfloxacin, and related agents.

    OpenAIRE

    Weinberg, E.; Shungu, D L; Gadebusch, H. H.

    1984-01-01

    The Antimicrobial Removal Device (ARD), BACTEC 16B medium, and Thiol broth were evaluated for their effectiveness in reducing the activity of imipenem (IPM), cefoxitin, moxalactam, and ceftazidime in blood samples. In addition, the capability of the ARD and Thiol broth to bind norfloxacin and the ARD to bind oxolinic and nalidixic acids in urine samples was investigated. At the highest concentrations of the drugs tested (32 micrograms/ml for the four beta-lactams and 256 micrograms/ml for the...

  12. Modeling the behavior of Listeria monocytogenes during enrichment in half Fraser broth; impact of pooling and the duration of enrichment on the detection of L. monocytogenes in food.

    Science.gov (United States)

    Augustin, Jean-Christophe; Kalmokoff, Martin; Ells, Timothy; Favret, Sandra; Desreumaux, Jennifer; Decourseulles Brasseur, Emilie; Gnanou Besse, Nathalie

    2016-12-01

    A stochastic model describing the growth of Listeria monocytogenes during enrichment in half Fraser was developed for the purpose of estimating the effects of modifications to the first enrichment step of the EN ISO 11290-1 detection method. Information pertaining to the variability of growth rates, physiological state of the cell, and the behavior of individual cells contaminating the food were obtained from previously published studies. We used this model to investigate the impact of pooling enrichment broths (wet pooling) on the performance of the standard method. For validation of the model, the numbers of L. monocytogenes occurring in 88 naturally contaminated foods following pre-enrichment were compared to model-simulated microbial counts. The model was then used to perform simulations representative of the natural contamination observed for smoked salmon in the European baseline survey of 2010-2011. The model-estimated L. monocytogenes levels following individual enrichment or following the pooling of five broths where only one would be contaminated were compared. The model indicated a 10% loss of method sensitivity resulting from wet pooling. The model also predicted a 5% decrease in the sensitivity of the method when the duration of the enrichment was reduced from 24 to 22 h. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Addition of Rifampicin to Bolton Broth to Inhibit Extended-Spectrum β-Lactamase-Producing Escherichia coli for the Detection of Campylobacter.

    Science.gov (United States)

    Chon, Jung-Whan; Kim, Young-Ji; Kim, Young-Jo; Jung, Ji Young; Bae, Dongryeoul; Khan, Saeed; Seo, Kun-Ho; Sung, Kidon

    2017-07-01

    Exponential growth of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in Campylobacter media has become a common problem for the detection of Campylobacter in chicken meats. We investigated the minimum inhibitory concentration of 40 ESBL-producing E. coli isolates from meats obtained from various countries against antibacterial agents in Bolton broth (cefoperazone, vancomycin, and trimethoprim). All ESBL-producing E. coli strains were resistant to cefoperazone and vancomycin, whereas 50% of them were resistant to trimethoprim and grew in Bolton broth. We found that 20 μg/mL of rifampicin inhibited the growth of trimethoprim-resistant E. coli strains. Hence, we added 20 μg/mL of rifampicin to Bolton broth to improve the isolation of Campylobacter from chicken carcass rinses. The isolation rate of Campylobacter was significantly higher in the modified broth (44 out of 58, 75.9%, P Campylobacter spp. was much lower after enrichment in the modified broth (4 out of 58, 6.9%, P < 0.05) than in the normal broth (58 out of 58, 100%). © 2017 Institute of Food Technologists®.

  14. Model-based design of a pilot-scale simulated moving bed for purification of citric acid from fermentation broth.

    Science.gov (United States)

    Wu, Jinglan; Peng, Qijun; Arlt, Wolfgang; Minceva, Mirjana

    2009-12-11

    One of the conventional processes used for the recovery of citric acid from its fermentation broth is environmentally harmful and cost intensive. In this work an innovative benign process, which comprises simulated moving bed (SMB) technology and use of a tailor-made tertiary poly(4-vinylpyridine) (PVP) resin as a stationary phase is proposed. This paper focuses on a model-based design of the operation conditions for an existing pilot-scale SMB plant. The SMB unit is modeled on the basis of experimentally determined hydrodynamics, thermodynamics and mass transfer characteristics in a single chromatographic column. Three mathematical models are applied and validated for the prediction of the experimentally attained breakthrough and elution profiles of citric acid and the main impurity component (glucose). The transport dispersive model was selected for the SMB simulation and design studies, since it gives a satisfactory prediction of the elution profiles within acceptable computational time. The equivalent true moving bed (TMB) and SMB models give a good prediction of the experimentally attained SMB separation performances, obtained with a real clarified and concentrated fermentation broth as a feed mixture. The SMB separation requirements are set to at least 99.8% citric acid purity and 90% citric acid recovery in the extract stream. The complete regeneration in sections 1 and 4 is unnecessary. Therefore the net flow rates in all four SMB sections have been considered in the unit design. The influences of the operating conditions (the flow rate in each section, switching time and unit configuration) on the SMB performances were investigated systematically. The resulting SMB design provides 99.8% citric acid purity and 97.2% citric acid recovery in the extract. In addition the citric acid concentration in the extract is a half of its concentration in the pretreated fermentation broth (feed).

  15. Phenolic Acid Changes in Mycelia of Sclerotium rolfsii After Garlic and Onion Supplementation in a Broth Medium.

    Science.gov (United States)

    Pandey, M K; Singh, D P; Singh, U P

    2005-09-01

    High performance liquid chromatographic (HPLC) analysis of mycelia of Sclerotium rolfsii grown in broth medium supplemented with garlic (Allium sativum) and onion (Allium cepa) was carried out to estimate qualitative and quantitative changes in phenolic acids. Several phenolic acids, such as gallic, chlorogenic, ferulic, o-coumaric and cinnamic acids were detected in varied amounts in mycelia grown on such media as compared to control. Phenolic acids represents a wide range of secondary metabolite found in the cells of plants and microbes including fungi. The growth characters of S. rolfsii in various supplements also varied from thin and transparent to thick and opaque.

  16. Comparison of the Vitek 2 yeast susceptibility system with CLSI microdilution for antifungal susceptibility testing of fluconazole and voriconazole against Candida spp., using new clinical breakpoints and epidemiological cutoff values.

    Science.gov (United States)

    Pfaller, Michael A; Diekema, Daniel J; Procop, Gary W; Rinaldi, Michael G

    2013-09-01

    A commercially available, fully automated yeast susceptibility test system (Vitek 2; bioMérieux, Marcy d'Etoile, France) was compared in 3 different laboratories with the Clinical and Laboratory Standards Institute (CLSI) reference microdilution (BMD) method by testing 2 quality control strains, 10 reproducibility strains, and 425 isolates of Candida spp. against fluconazole and voriconazole. Reference CLSI BMD MIC endpoints and Vitek 2 MIC endpoints were read after 24 hours and 9.1-27.1 hours incubation, respectively. Excellent essential agreement (within 2 dilutions) between the reference and Vitek 2 MICs was observed for fluconazole (97.9%) and voriconazole (96.7%). Categorical agreement (CA) between the 2 methods was assessed using the new species-specific clinical breakpoints (CBPs): susceptible (S) ≤2 μg/mL, susceptible dose-dependent (SDD) 4 μg/mL, and resistant (R) ≥8 μg/mL for fluconazole and Candida albicans, Candida tropicalis, and Candida parapsilosis and ≤32 μg/mL (SDD), ≥64 μg/mL (R) for Candida glabrata; S ≤0.12 μg/mL, SDD 0.25-0.5 μg/mL, R ≥1 μg/mL for voriconazole and C. albicans, C. tropicalis, and C. parapsilosis, and ≤0.5 μg/mL (S), 1 μg/mL (SDD), ≥2 μg/mL (R) for Candida krusei. The epidemiological cutoff value (ECV) of 0.5 μg/mL for voriconazole and C. glabrata was used to differentiate wild-type (WT; MIC ≤ ECV) from non-WT (MIC > ECV) strains of this species. Due to the lack of CBPs for the less common species, the ECVs for fluconazole and voriconazole, respectively, were used for Candida lusitaniae (2 μg/mL and 0.03 μg/mL), Candida dubliniensis (0.5 μg/mL and 0.03 μg/mL), Candida guilliermondii (8 μg/mL and 0.25 μg/mL), and Candida pelliculosa (4 μg/mL and 0.25 μg/mL) to categorize isolates of these species as WT and non-WT. CA between the 2 methods was 96.8% for fluconazole and 96.5% for voriconazole with less than 1% very major errors and 1.3-3.0% major errors. The Vitek 2 yeast susceptibility system

  17. Comparison of disc and MIC reduction methods with polymerase chain reaction for the detection of metallo-β-lactamase in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    S Buchunde

    2012-01-01

    Full Text Available Purpose: The present study was undertaken to evaluate the screening antibiotic, confirmatory phenotypic test and agent against PCR as gold standard and to detect the prevalent MBL gene. Materials and Methods: Three hundred and twenty-six Pseudomonas aeruginosa isolates were screened for resistance to Imipenem (IPM, Meropemem (MEM and Ceftazidime (CAZ by disc diffusion. Isolates resistant to any of these were considered screen test-positive for MBL and were subjected to Double disc synergy test (DDST and Disc potentiation test (DPT: Using IPM, MEM and CAZ alone and with EDTA, Minimum inhibitory concentration (MIC reduction [four-fold or more reduction in MIC of IPM and MEM in presence of chelators: EDTA and 1,10-phenanthroline (EPI/EPM: EDTA-phenanthroline- Imipenem/Meropenem Broth Microdilution method] and polymerase chain reaction (PCR for blaIMP and blaVIM . Results: Screen test-positives by MEM and CAZ were 19.3% as against 17.8% by IPM. MEMDDST, DPT and EPM confirmed 100% screen-test positives as against 93.7% by CAZ DDST and DPT-2, 76.2% by CAZ DPT-1, 88.9% by IPM DDST, 85.7% by IPM DPT-1 and 92.1% by EPI. IPMand CAZ DDST together confirmed 100% while IPM and CAZ DPT-2 confirmed 96.8%. All 63 screen-test positives showed the presence of blaVIM . Conclusions: MEM was found to be the best screening and confirmatory agent for MBL detection and blaVIM was found to be the prevalent MBL gene in this part of the country.

  18. Methods for broth dilution susceptibility testing of bacteria isolated from aquatic animals; approved guideline-second edition

    Science.gov (United States)

    Antimicrobial susceptibility testing is recommended to determine which antimicrobial agents should be considered for treating a bacterial pathogen. Many bacteria that cause disease in aquatic animals require growth conditions that vary substantially from routine terrestrial pathogens. It has thus ...

  19. A multipathogen selective enrichment broth for simultaneous growth of Salmonella enterica serovar Enteritidis, Staphylococcus aureus, and Listeria monocytogenes.

    Science.gov (United States)

    Yu, Yi-Gang; Wu, Hui; Liu, Yuan-Yuan; Li, Su-Long; Yang, Xiao-Quan; Xiao, Xing-Long

    2010-07-01

    A selective enrichment broth (SSL) was formulated to allow concurrent growth of 3 prominent food-borne pathogens: Salmonella enterica serovar Enteritidis, Staphylococcus aureus, and Listeria monocytogenes. Nalidixic acid, lithium chloride, and potassium tellurite were added as the selective agents, while sodium pyruvate and mannitol were employed as the supplemented elements. In the individual growth trial, the target pathogens were capable of growing in SSL to as high as 7-8 log(10) colony-forming units (CFU)/mL after 24 h incubation at 37 degrees C when being inoculated at 50-100 CFU/mL. In the simultaneous growth trial, the 3 combined target pathogens showed similar growth rates. The results show that SSL could support the successful simultaneous enrichment of 3 pathogens; however, SSL inhibited the growth of nontarget bacteria. In the artificial contaminated raw beef and ready-to-eat chicken, a high recovery of these 3 target pathogens was obtained in SSL. Finally, Salmonella Enteritidis, Staphylococcus aureus, and L. monocytogenes were detected from 710 suspicious food samples by SSL with real-time PCR, and no false-positive or -negative results were reported. In summary, SSL has been shown to be a suitable broth for the simultaneous detection of the 3 prominent food-borne pathogens by multipathogen detection on a single-assay platform.

  20. Isolation of natural red colorants from fermented broth using ionic liquid-based aqueous two-phase systems.

    Science.gov (United States)

    Ventura, Sónia P M; Santos-Ebinuma, Valéria C; Pereira, Jorge F B; Teixeira, Maria F S; Pessoa, Adalberto; Coutinho, João A P

    2013-05-01

    There is a growing demand for natural colorants. This is prompting the search for new alternative and "benign" separation systems allowing higher recoveries, extraction yields, and selectivities. This work investigates the use of aqueous two-phase systems (ATPS) based on ionic liquids as extraction processes for the recovery of red colorants from the fermented broth of Penicillium purpurogenum DPUA 1275. Several ATPS based on quaternary ammonium and imidazolium were studied in this work aiming at separating the red colorants produced from the remaining colorants and contaminant proteins present in the fermented broth. The results suggest that the red colorants can be isolated by an appropriate manipulation of some of the process conditions, such as the use of quaternary ammonium with short alkyl chains, alkaline media, and short tie-line lengths (extraction point systems with lower concentrations of ionic liquid). These conditions allow large partition coefficients for the red colorants (K red = 24.4 ± 2.3), high protein removal (60.7 ± 2.8 %) and selectivity parameters (S red/prot = 10.05).

  1. Comprehension of viscous morphology--evaluation of fractal and conventional parameters for rheological characterization of Aspergillus niger culture broth.

    Science.gov (United States)

    Wucherpfennig, Thomas; Lakowitz, Antonia; Krull, Rainer

    2013-01-20

    The filamentous fungus Aspergillus niger is a widely used host in industrial processes from food, chemical to pharmaceutical industry. The most prominent feature of this filamentous microorganism in submerged cultivation is its complex morphology which comprises dense spherical pellets as well as viscous elongated filaments. Depending on culture conditions, the exhibited morphology has tremendous effect on the overall process, making a precise understanding of fungal growth and morphology indispensable. Morphology, however, is only industrially relevant as long as it can be linked to important cultivation characteristics of filamentous microorganisms such as culture broth flow behavior. In the present study, different conventional and fractal morphological parameters gained from automatic image analysis were tested for their eligibility to predict culture broth rheology from morphologic appearance. The introduced biomass independent rheological parameters K(BDW) and n(BDW) obtained by power law relationship were successfully estimated from morphology related fractal and conventional parameters. For improved characterization of morphologic appearance of filamentous fungi newly introduced fractal quotient and lacunarity were compared to conventional particle shape parameters in form of the earlier established Morphology number (MN). Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Multi-probe real-time PCR identification of four common Candida species in blood culture broth.

    Science.gov (United States)

    Foongladda, Suporn; Mongkol, Nanthanida; Petlum, Pornphan; Chayakulkeeree, Methee

    2014-06-01

    We developed a single-tube real-time polymerase chain reaction (PCR) assay with multiple hybridization probes for detecting Candida albicans, C. tropicalis, C. glabrata, and C. parapsilosis. Primers were designed to amplify 18S rRNA gene of the genus Candida, and DNA probes were designed to hybridize two areas of the amplicons. The amplification curves and specific melting peaks of the probes hybridized with PCR product were used for definite species identifications. The reaction specificity was 100 % when evaluating the assay using DNA samples from 21 isolates of fungal and bacterial species. The assay was further evaluated in 129 fungal blood culture broth samples which were culture positive for fungus. Of the 129 samples, 119 were positively identified as: C. albicans (39), C. tropicalis (30), C. parapsilosis (23), C. glabrata (20), Candida spp. (5), and two samples containing mixed C. glabrata/C. albicans and C. glabrata/C. tropicalis. The five Candida spp. were identified by sequencing analysis as C. krusei, C. dubliniensis, C. aquaetextoris, and two isolates of C. athensensis. Of the ten samples which showed negative PCR results, six were Cryptococcus neoformans, and the others were Trichosporon sp., Rhodotorula sp., Fusarium sp., and Penicillium marneffei. Our findings show that the assay was highly effective in identifying the four medically important Candida species. The results can be available within 3 h after positivity of a blood culture broth sample.

  3. Variation of broth composition by addition of broiler litter composting substrate extracts: influence on faecal bacterial growth.

    Science.gov (United States)

    Sobratee, N; Mohee, R; Driver, M-F B

    2009-10-01

    This study investigates differences in bacterial growth response in broth amended with compost-substrate extracts periodically bypassed during broiler litter composting. Compost samples, suspended in diluent were mixed with double strength broth into which ampicillin selective (0.3 g l(-1)) Escherichia coli and E. faecalis were separately seeded. Growth was measured by viable cell count. The Levenberg-Marquardt algorithm was applied to obtain a four-parameter sigmoidal function that best described the diminishing height transitions of the curves for extracts of increasing composting age. The time course of the growth rate followed a unimodal bell-shaped curve. The Microfit application was run to generate information of direct microbiological interest: increasing lambda and decreasing mu(max) for both bacteria with time. More than the curve-fitting process, the Unified model option of the Microfit application has confirmed the significant differences (P microbiology concepts. Further structured studies are needed to fine-tune the generality of the findings for model development.

  4. Method for bacteriophage isolation against target Campylobacter strains

    National Research Council Canada - National Science Library

    Carvalho, C; Susano, M; Fernandes, E; Santos, S; Gannon, B; Nicolau, A; Gibbs, P; Teixeira, P; Azeredo, J

    2010-01-01

    .... This work focuses on the isolation of Campylobacter coli lytic bacteriophages (phages) against target C. coli strains. A method involving the enrichment of free-range chicken samples in a broth containing the target C...

  5. Inactivation effect of X-ray treatments on Cronobacter species (Enterobacter sakazakii) in tryptic soy broth, skim milk, low-fat milk and whole-fat milk.

    Science.gov (United States)

    Mahmoud, B S M

    2009-11-01

    To determine the inactivation effect of X-ray treatments on Cronobacter (E. sakazakii) in tryptic soy broth (TSB), skim milk (0% fat), low-fat milk (1% and 2%) and whole-fat milk (3.5%). X-rays were produced using the RS 2400 generator system (Rad Source Technologies Inc.). Cronobacter (in TSB), inoculated skim milk (0% fat), low-fat milk (1% and 2% fat) and whole-fat milk (3.5% fat) were treated with 0.0, 0.1, 0.5, 0.75, 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 kGy X-ray doses. Surviving bacteria in the TSB and inoculated milk, before and after treatment, were enumerated using plating method onto trypticase soy agar. Greater than 7.0-log CFU reduction in Cronobacter population was observed with 4.0, 5.0, 6.0, 6.0 and 6.0 kGy X-ray in the TSB, skim milk, 1% fat milk, 2% fat milk and 3.5% fat milk, respectively. Treatment with X-rays significantly (P industry.

  6. Comparison of the Lysis Centrifugation Method with the Conventional Blood Culture Method in Cases of Sepsis in a Tertiary Care Hospital

    Directory of Open Access Journals (Sweden)

    Harshal R Parikh

    2012-01-01

    Conclusion: For the diagnosis of sepsis, combination of the lysis centrifugation method and the conventional blood culture method with trypticase soy broth or biphasic media is advocable, in order to achieve faster recovery and a better yield of microorganisms.

  7. Comparison of adsorption equilibrium and kinetic models for a case study of pharmaceutical active ingredient adsorption from fermentation broths: parameter determination, simulation, sensitivity analysis and optimization

    Directory of Open Access Journals (Sweden)

    B. Likozar

    2012-09-01

    Full Text Available Mathematical models for a batch process were developed to predict concentration distributions for an active ingredient (vancomycin adsorption on a representative hydrophobic-molecule adsorbent, using differently diluted crude fermentation broth with cells as the feedstock. The kinetic parameters were estimated using the maximization of the coefficient of determination by a heuristic algorithm. The parameters were estimated for each fermentation broth concentration using four concentration distributions at initial vancomycin concentrations of 4.96, 1.17, 2.78, and 5.54 g l−¹. In sequence, the models and their parameters were validated for fermentation broth concentrations of 0, 20, 50, and 100% (v/v by calculating the coefficient of determination for each concentration distribution at the corresponding initial concentration. The applicability of the validated models for process optimization was investigated by using the models as process simulators to optimize the two process efficiencies.

  8. Effectiveness of the antimicrobial removal device, BACTEC 16B medium, and thiol broth in neutralizing antibacterial activities of imipenem, norfloxacin, and related agents.

    Science.gov (United States)

    Weinberg, E; Shungu, D L; Gadebusch, H H

    1984-02-01

    The Antimicrobial Removal Device (ARD), BACTEC 16B medium, and Thiol broth were evaluated for their effectiveness in reducing the activity of imipenem (IPM), cefoxitin, moxalactam, and ceftazidime in blood samples. In addition, the capability of the ARD and Thiol broth to bind norfloxacin and the ARD to bind oxolinic and nalidixic acids in urine samples was investigated. At the highest concentrations of the drugs tested (32 micrograms/ml for the four beta-lactams and 256 micrograms/ml for the three quinolinecarboxylic acids), there was at least a 95% reduction in the in vitro activity of each of the antibacterial agents for treated versus untreated samples. Of the compounds tested in the ARD system, the organic acids were more completely removed than were the beta-lactams. The Thiol broth was more effective than the ARD and the BACTEC 16B medium in inactivating imipenem, but it had no effect on the antibacterial activity of norfloxacin.

  9. Oxidative production of xylonic acid using xylose in distillation stillage of cellulosic ethanol fermentation broth by Gluconobacter oxydans.

    Science.gov (United States)

    Zhang, Hongsen; Han, Xushen; Wei, Chengxiang; Bao, Jie

    2017-01-01

    An oxidative production process of xylonic acid using xylose in distillation stillage of cellulosic ethanol fermentation broth was designed, experimentally investigated, and evaluated. Dry dilute acid pretreated and biodetoxified corn stover was simultaneously saccharified and fermented into 59.80g/L of ethanol (no xylose utilization). 65.39g/L of xylose was obtained in the distillation stillage without any concentrating step after ethanol was distillated. Then the xylose was completely converted into 66.42g/L of xylonic acid by Gluconobacter oxydans. The rigorous Aspen Plus modeling shows that the wastewater generation and energy consumption was significantly reduced comparing to the previous xylonic acid production process using xylose in pretreatment liquid. This study provided a practical process option for xylonic acid production from lignocellulose feedstock with significant reduction of wastewater and energy consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Purification of nattokinase by reverse micelles extraction from fermentation broth: effect of temperature and phase volume ratio.

    Science.gov (United States)

    Liu, Jun-Guo; Xing, Jian-Min; Chang, Tian-Shi; Liu, Hui-Zhou

    2006-03-01

    Nattokinase is a novel fibrinolytic enzyme that is considered to be a promising agent for thrombosis therapy. In this study, reverse micelles extraction was applied to purify and concentrate nattokinase from fermentation broth. The effects of temperature and phase volume ratio used for the forward and backward extraction on the extraction process were examined. The optimal temperature for forward and backward extraction were 25 degrees C and 35 degrees C respectively. Nattokinase became more thermosensitive during reverse micelles extraction. And it could be enriched in the stripping phase eight times during backward extraction. It was found that nattokinase could be purified by AOT reverse micelles with up to 80% activity recovery and with a purification factor of 3.9.

  11. Impact of changes in broth composition on Chlorella vulgaris cultivation in a membrane photobioreactor (MPBR) with permeate recycle.

    Science.gov (United States)

    Discart, V; Bilad, M R; Marbelia, L; Vankelecom, I F J

    2014-01-01

    A membrane photobioreactor (MPBR) is a proven and very useful concept in which microalgae can be simultaneously cultivated and pre-harvested. However, the behavior with respect to accumulation of algogenic organic matter, including transparent exopolymeric particles (TEPs), counter ions and unassimilated nutrients due to the recycling of the medium is still unclear, even though the understanding of this behavior is essential for the optimization of microalgae processing. Therefore, the dynamics of these compounds, especially TEPs, during coupled cultivation and harvesting of Chlorella vulgaris in an MPBR with permeate recycle are addressed in this study. Results show that TEPs are secreted during algae cell growth, and that their presence is thus inevitable. In the system with permeate recycle, substances such as counter ions and unassimilated nutrients get accumulated in the system. This was proven to limit the algae growth, together with the occurrence of bioflocculation due to an increasing broth pH. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Antimycobacterial, antioxidant and cytotoxic activities of essential oil ...

    African Journals Online (AJOL)

    Background: The aim of this study was to assess the antimycobacterial, antioxidant and the cytotoxic activities of the essential oil from the gall part of Pistacia atlantica Desf from Algeria. Materials and Methods: The antimycobacterial activity was evaluated by the broth microdilution method against three species of ...

  13. Anti-vibrio potentials of acetone and aqueous leaf extracts of ...

    African Journals Online (AJOL)

    Purpose: To evaluate the anti-vibrio potentials of acetone and aqueous leaf extracts of Ocimum gratissimum and determine its relevance in the treatment of vibrios infection. Methods: The agar-well diffusion method was used for screening the extracts for their anti-vibrio activity. Broth micro-dilution assay was used to ...

  14. Antimicrobial Activity of Untenospongin B, a Metabolite from the Marine Sponge Hippospongia communis collected from the Atlantic Coast of Morocco

    Science.gov (United States)

    Rifai, Saida; Fassouane, Aziz; Kijjoa, Anake; Van Soest, Rob

    2004-01-01

    (−)-Untenospongin B isolated from the marine sponge Hippospongia communis has been tested for its antimicrobial activity against bacteria and human pathogenic fungi using agar disk method and was found to possess a broad and strong activity toward the test organisms. Its antifungal activity was further characterized by determination of the minimum inhibitory concentration (MIC) against five fungal species using broth microdilution method.

  15. Antimycobacterial, Antioxidant and Cytotoxic activities of Essential ...

    African Journals Online (AJOL)

    SIFI IBRAHIM

    Background: The aim of this study was to assess the antimycobacterial, antioxidant and the cytotoxic activities of the essential oil from the gall part of Pistacia atlantica Desf from Algeria. Materials and Methods: The antimycobacterial activity was evaluated by the broth microdilution method against three species of ...

  16. Antibacterial and antifungal activity of lawsone and novel naphthoquinone derivatives

    OpenAIRE

    Rahmoun, N.M.; Boucherit-Otmani, Z.; Boucherit, K.; Benabdallah, M.; Villemin, D.; Choukchou-Braham, N.

    2012-01-01

    Introduction. – Naphthoquinone derivatives are under investigation as potential therapeutic agents. The antibacterial and antifungal activity of lawsone and of some novel naphthoquinone derivatives was assessed in vitro. Methods. – The antimicrobial activity was determined using diffusion disk and the broth microdilution methods against seven bacteria and three Candida species, according to recommendations of the Clinical and Labo...

  17. Direct blood culturing on solid medium outperforms an automated continuously monitored broth-based blood culture system in terms of time to identification and susceptibility testing

    Directory of Open Access Journals (Sweden)

    E.A. Idelevich

    2016-03-01

    Full Text Available Pathogen identification and antimicrobial susceptibility testing (AST should be available as soon as possible for patients with bloodstream infections. We investigated whether a lysis-centrifugation (LC blood culture (BC method, combined with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS identification and Vitek 2 AST, provides a time advantage in comparison with the currently used automated broth-based BC system. Seven bacterial reference strains were added each to 10 mL human blood in final concentrations of 100, 10 and 1 CFU/mL. Inoculated blood was added to the Isolator 10 tube and centrifuged at 3000 g for 30 min, then 1.5 mL sediment was distributed onto five 150-mm agar plates. Growth was observed hourly and microcolonies were subjected to MALDI-TOF MS and Vitek 2 as soon as possible. For comparison, seeded blood was introduced into an aerobic BC bottle and incubated in the BACTEC 9240 automated BC system. For all species/concentration combinations except one, successful identification and Vitek 2 inoculation were achieved even before growth detection by BACTEC. The fastest identification and inoculation for AST were achieved with Escherichia coli in concentrations of 100 CFU/mL and 10 CFU/mL (after 7 h each, while BACTEC flagged respective samples positive after 9.5 h and 10 h. Use of the LC-BC method allows skipping of incubation in automated BC systems and, used in combination with rapid diagnostics from microcolonies, provides a considerable advantage in time to result. This suggests that the usefulness of direct BC on solid medium should be re-evaluated in the era of rapid microbiology.

  18. Detection of Burkholderia pseudomallei in Sputum using Selective Enrichment Broth and Ashdown’s Medium at Kampong Cham Provincial Hospital, Cambodia [v1; ref status: indexed, http://f1000r.es/4w7

    Directory of Open Access Journals (Sweden)

    Somary Nhem

    2014-12-01

    Full Text Available Melioidosis infection, caused by Burkholderia pseudomallei, is increasingly reported in Cambodia. We hypothesized that implementation of an enhanced sputum testing protocol in a provincial hospital diagnostic microbiology laboratory would increase detection of B. pseudomallei. We tested 241 sputum specimens that were deemed acceptable for culture, comparing culture in selective enrichment broth followed by sub-culture on Ashdown’s medium to standard culture methods. Two specimens (0.8% were positive for B. pseudomallei using the enhanced protocol whereas one specimen (0.4% was positive using standard methods. These findings demonstrate that B. pseudomallei is rarely detected in sputum at this hospital. The low frequency of B. pseudomallei in sputum specimens precludes drawing any conclusions about the relative benefits of an enhanced sputum testing protocol at this site. Promoting clinician awareness of the infection and encouraging utilization of diagnostic microbiology services are likely to be important factors in facilitating identification of melioidosis.

  19. Evaluation of different buffered peptone water (BPW) based enrichment broths for detection of Gram-negative foodborne pathogens from various food matrices

    NARCIS (Netherlands)

    Margot, H.; Zwietering, M.H.; Joosten, H.M.L.J.; O'Mahony, E.; Stephan, R.

    2015-01-01

    This study evaluated the effects of changing the composition of the pre-enrichment medium buffered peptone water (BPW) on the growth of stressed and unstressed Gram-negative foodborne pathogens in a one-broth enrichment strategy. BPW supplemented with an available iron source and sodium pyruvate,

  20. Investigations on interfaciale activity of a biosurfactant from a xanthan broth; Untersuchungen zur Grenzflaechenaktivitaet eines Biotensids aus Xanthan-Bruehen

    Energy Technology Data Exchange (ETDEWEB)

    Birdi, K.S. [Royal Danish School of Pharmacy, Kopenhagen (Denmark); Kleinitz, W. [Preussag Energie GmbH, Lingen (Germany); Littmann, W. [Littmann Consult, Wunstorf (Germany)

    1997-10-01

    In order to improve crude oil production, various field projects have been conducted by Preussag Energie GmbH. In these tests, the viscosity of the reservoir water was increased to the value of crude oil by polymer addition. It is well known that this displacement process results in enhanced oil recovery. A surprising discovery was the pressure of stable oil-in-water emulsions when xanthane a biopolymer which is stable in salt water was used in the form of the fermentation broth and if xanthane was also detected in the reservoir water in the production fluid. Industrial xanthanes from various manufacturers exhibited interfacial activity only when used as fermentation broths. Powdered products were inert. The application of fluorescence spectrometry has proved that the biosurfactant is not a protein. The interfacial activity has been determined by monolayer measurements at various pll-values and salt concentrations. The critical micelle concentration of about 100 mg/l is stable over a wide range of temperatures and salinities. Potential applications of this surfactant include the stimulation of oil and gas wells. (orig.) [Deutsch] Zur Verbesserung der Rohoelfoerderung wurden von der Preussag Energie GmbH verschiedene Feldprojekte durchgefuehrt, bei denen durch Polymerzugabe die Viskositaet des Lagerstaettenwassers auf den Betrag des Rohoels angehoben wurde. Dieser Verdraengungsvorgang fuehrt bekanntlich zu einer Erhoehung der Erdoelausbeute. Bei Einsatz des salzwasserstabilen Biopolymers Xanthan in Form der Fermentationsbruehe wurden ueberraschenderweise dann stabile Oel-in-Wasser-Emulsionen festgestellt, wenn in dem Fluid an der Produktionsbohrung auch Xanthan im Lagerstaettenwasser nachgewiesen werden konnte. Industrielle Xanthane von verschiedenen Herstellern zeigten nur bei Verwendung von Fermentationsbruehen Grenzflaechenaktivitaet. Pulverprodukte waren inert. Mittels Fluoreszenzspektrometrie konnte nachgewiesen werden dass es sich bei dem Biotensid nicht um

  1. Chemical composition and bioactive properties of the lichen ...

    African Journals Online (AJOL)

    Antimicrobial activity was estimated by determination of the minimal inhibitory concentration using broth microdilution method. Anticancer activity of the lichen extract was tested using 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT). Results: Salazinic, norstictic, protocetraric, evernic acid and atranorin were ...

  2. Ethnopharmacological survey, antioxidant and antifungal activity of ...

    African Journals Online (AJOL)

    The antifungal activity was assessed by the broth micro-dilution method and the antioxidant activity was determined using the free-radical scavenging assays. The extracts for the plants Kotschya strigosa and Eryngium foetidum had potent antifungal activity with minimum inhibitory concentration value of 32 μg/mL against ...

  3. Antimicrobial susceptibility in community-acquired bacterial ...

    African Journals Online (AJOL)

    Design: Cross-sectional study. Setting: Bacterial isolates were obtained from adults suspected to have community-acquired pneumonia and who sought treatment at two city council clinics in Nairobi, Kenya. Susceptibility to antimicrobial agents was performed using a microdilution broth method, according to the criteria set ...

  4. Antimicrobial activity of Piper arboreum and Piper tuberculatum ...

    African Journals Online (AJOL)

    In the scope of our ongoing research on bioactive agents from natural sources, 24 extracts and fractions obtained from Piper arboreum Aub. and Piper tuberculatum Jacq. (Piperaceae) were screened for antifungal activity by using broth microdilution method. The current investigation reveals that P. arboreum extracts and ...

  5. Effect of pH on the in vitro activities of amphotericin B, itraconazole, and flucytosine against Aspergillus isolates

    NARCIS (Netherlands)

    Te Dorsthorst, DTA; Mouton, JW; van den Beukel, CJP; van der Lee, HAL; Meis, JFGM; Verweij, PE

    The in vitro susceptibilities of 21 Aspergillus isolates were tested against three antifungal agents in RPMI 1640 and yeast nitrogen base at pH 5.0 and 7.0 by a broth microdilution format of the NCCLS method. The MICs of amphotericin B and itraconazole were higher, while those of flucytosine were

  6. Fast quantitative determination of microbial rhamnolipids from cultivation broths by ATR-FTIR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Hausmann Rudolf

    2008-10-01

    Full Text Available Abstract Background Vibrational spectroscopic techniques are becoming increasingly important and popular because they have the potential to provide rapid and convenient solutions to routine analytical problems. Using these techniques, a variety of substances can be characterized, identified and also quantified rapidly. Results The rapid ATR-FTIR (Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy in time technique has been applied, which is suitable to quantify the concentrations of microbial rhamnolipids in a typical cultivation process. While the usually applied HPLC analysis requires an extensive and time consuming multi step extraction protocol for sample preparation, the ATR-FTIR-method allows the quantification of the rhamnolipids within 20 minutes. Accuracies between 0.5 g/l – 2.1 g/l for the different analytes were determined by cross validation of the calibration set. Even better accuracies between 0.28 g/l – 0.59 g/l were found for independent test samples of an arbitrarily selected cultivation. Conclusion ATR-FTIR was found to be suitable for the rapid analysis of rhamnolipids in a biotechnological process with good reproducibility in sample determination and sufficient accuracy. An improvement in accuracy through continuous expansion and validation of the reference spectra set seems very likely.

  7. Phytochemical fabrication and characterization of silver nanoparticles by using Pepper leaf broth

    Directory of Open Access Journals (Sweden)

    K. Mallikarjuna

    2014-12-01

    Full Text Available The Pepper leaves extract acts as a reducing and capping agent in the formation of silver nanoparticles. A UV–Vis spectrum of the aqueous medium containing silver nanoparticles demonstrated a peak at 458 nm corresponding to the plasmon absorbance of rapidly synthesized silver nanoparticles that was characterized by UV–Vis spectrophotometer. The morphology and size of the benign silver nanoparticles were carried out by the transmission electron microscope (TEM and field emission scanning electron microscope (FE-SEM. The sizes of the synthesized silver nanoparticles were found to be in the range of 5–60 nm. The structural characteristics of biomolecules hosted silver nanoparticles were studied by X-ray diffraction. The chemical composition of elements present in the solution was determined by energy dispersive spectrum. The FTIR analysis of the nanoparticles indicated the presence of proteins, which may be acting as capping agents around the nanoparticles. This study reports that synthesis is useful to avoid toxic chemicals with adverse effects in medical applications rather than physical and chemical methods.

  8. Efek Penambahan Glukosa pada Saburoud Dextrose Broth terhadap Pertumbuhan Candida albicans (Uji In Vitro

    Directory of Open Access Journals (Sweden)

    Lakshmi A. Leepel

    2012-10-01

    Full Text Available High carbohydrate intake is one of predisposing factors of oral candidiasis. Objective: Investigating the effect of 1%,5%,10% glucose addition on the growth of C.albicans in vitro. Method: C.albicans sample was taken from oral swab of a male oral candidiasis patient. Identification of C.albicans was conducted using CHROMagar and confirmed by germ tube formation in serum. As a comparison, C.albicans ATCC10231 was used. After 2 days the cultures were serially diluted and inoculated in SDB without glucose, and with 1%,5%,10% addditional glucose, kept for 3 and 7 days in room temperature, then inoculated in SDA. The CFU/ml were counted after 2 days. ANOVA with α0.05 was used. Result: Statisticaly, additional 1% glucose for 3 days lead to significant decreased of growth of both clinical strain and ATCC 10231 C. albicans. However, only additional 5% and 10% glucose in clinical isolate for 7 days increased the growth of C.albicans significantly. Conclusion: The effect of additional glucose on the increased growth of C.albicans in vitro is influenced by the concentration, exposure duration of glucose, and by the strain of C.albicans.DOI: 10.14693/jdi.v16i1.14

  9. Effective extraction of elastase from Bacillus sp. fermentation broth using aqueous two-phase system*

    Science.gov (United States)

    Xu, Ying; He, Guo-qing; Li, Jing-jun

    2005-01-01

    This paper presents the evaluation of an aqueous two-phase system (ATPS) for extracting elastase produced by Bacillus sp. EL31410. The elastase and cell partition behavio r in polyethylene glycol (PEG)/salt systems was investigated. The suitable system for elastase extraction was PEG/KH2PO4-K2HPO4, in which elastase is mainly partitioned into the PEG-rich phase, while the cells remained in the other phase. The influence of defined system parameters (e.g. PEG molecular mass, pH, NaCl addition) on the partitioning behavior of elastase is described. The concentration of phase forming components, PEG and KH2PO4-K2HPO4, was optimized for elastase recovery by means of response surface methodology, and it was found that they greatly influenced extraction recovery. The optimal ATPS was 23.1% (w/w) PEG 2 000 and 11.7% (w/w) KH2PO4-K2HPO4. The predicted recovery was about 89.5%, so this process is suggested to be a rapid and convenient method for elastase extraction. PMID:16252343

  10. Biogenic Preparation of Gold Nanostructures Reduced from Piper longum Leaf Broth and Their Electrochemical Studies.

    Science.gov (United States)

    Mallikarjuna, K; Narasimha, G; John Sushma, N; Dillip, G R; Subba Reddy, B V; Sreedhar, B; Deva Prasad Raju, B

    2015-02-01

    Exploitation of green chemical procedures for the synthesis of metal nanoparticles by biological process has received great attention in the field of nanotechnology. To demonstrate a biogenic method that involves the reduction of aqueous gold ions by the extract of Piper longum leaves leading to the formation of different morphological gold nanoparticles (AuNPs). The formation of gold nano-structures has been characterized by UV-Vis absorption spectroscopy. The X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns indicates the AuNPs are highly crystalline nature with the face-centered cubic (111), (200), (220) and (311) facets, respectively. The AuNPs have different sizes and morphologies that are identified by TEM studies. The involvement of water soluble bio-molecules such as carboxylic acids, flavonoids, proteins and terpenoids were identified by Fourier transform infrared (FT-IR) and Raman spectrum. The responsible mechanism of improving acidic nature and the process of encapsulation of gold nanoparticles by Piper longum extract was discussed. Additionally, we have demonstrated the modified carbon paste electrode using gold nanoparticles by means of cyclic voltammetry in a solution of 1 M KCI and 1 mM [Fe(CN)6]3-/4-. The analysis of cyclic voltammetry shows electronic transmission rate between modified Au-CPE and Bare-CPE electrode increased.

  11. Fabrication and characterization of silver nanoparticles using Delonix elata leaf broth.

    Science.gov (United States)

    Sathiya, C K; Akilandeswari, S

    2014-07-15

    The synthesis of nanoparticles from plant sources has proved to be an effective and alternative method for the novel production of nanoparticles. This paper reports the bioreduction of silver nitrate into silver nanoparticle by the leaf extract of Delonix elata. The synthesized silver nanoparticles were characterized by UV-visible (UV-vis) spectroscopy, Fourier infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS), high resolution transmission electron microscope (HRTEM). In addition the size of the NPs was calculated by using Malvern Zetasizer and the stability by zeta potential. UV-vis spectra show the surface plasmon resonance (SPR) at 432 nm. This reveals the reduction of silver ions (Ag(+)) into silver (Ag°) and indicating the formation of silver nanoparticles (AgNPs). SEM analysis revealed the spherical shape of the particles with sizes in the range of 35-45 nm and EDS spectrum confirmed the presence of silver along with other elements in the plant metabolite. The XRD analysis showed that the AgNPs are crystalline in nature and have face-centered cubic structure. FT-IR spectra show the existence of biomolecules responsible for the reduction of silver nitrate. The size of the AgNPs estimated from particle size distribution curve shows the 70 nm. The zeta potential of AgNPs was found to be -18 mV, indicating the dispersion and stability. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Comparison of EUCAST and CLSI Reference Microdilution MICs of Eight Antifungal Compounds for Candida auris and Associated Tentative Epidemiological Cutoff Values

    DEFF Research Database (Denmark)

    Arendrup, M. C.; Prakash, Anupam; Meletiadis, Joseph

    2017-01-01

    Candida auris is an emerging multidrug-resistant yeast. So far, all but two susceptibility testing studies have examined ≤50 isolates, mostly with the CLSI method. We investigated CLSI and EUCAST MICs for 123C. aurisisolates and eight antifungals and evaluated various methods for epidemiological ......, the estimated ECOFFs were dependent on the method applied for voriconazole (1 to 32) and isavuconazole (0.125 to 4). CLSI and EUCAST MICs were remarkably similar and confirmed uniform fluconazole resistance and variable acquired resistance to the other agents....

  13. Do too many cooks spoil the broth? The effect of observers on doctor-patient interaction.

    Science.gov (United States)

    Bristowe, Katherine; Patrick, Peter L

    2012-08-01

    The presence of additional medical personnel in consultations alters the focus of the doctor-patient interaction. Patients feel excluded from the interaction and relegated to the role of a non-person or prop, which leads to a loss of autonomy. Previous research has considered the psychological effects of the presence of additional persons on the interaction, but few studies have considered how these additional persons affect the performances of the consulting doctor and patient in the interaction. A linguistic study drawing on the methods of discourse analysis was conducted to consider how the presence of additional medical personnel in the consultation alters doctors' responses to patients' questions, their management of patient-initiated topics, and their use of invitations to ask questions. When additional professionals were present in the consultation, the consultations were significantly longer than control group consultations (p = 0.04) and significantly more patient-initiated topics remained unresolved at the close of the consultation (p = 0.04). In consultations in which students were present, markedly fewer patient questions were answered than in control group consultations, and there was a notable reduction in the number of overt invitations to ask questions (both differences approached significance). There was, however, a significant reduction (p ≤ 0.01) in the proportion of patient-initiated topics that were deferred when students were present in the consultation. Previous research has identified a loss of patient focus when a patient sees doctors en masse. The results from the present study suggest that the presence of additional medical personnel can distract the focus of a consultation away from the patient, particularly when the additional participants are professionals rather than students. Further research is required to develop a greater understanding of multiple-doctor-patient interactions. A training programme should be developed to train

  14. Comparison of visual 24-hour and spectrophotometric 48-hour MICs to CLSI reference microdilution MICs of fluconazole, itraconazole, posaconazole, and voriconazole for Candida spp.: a collaborative study.

    NARCIS (Netherlands)

    Espinel-Ingroff, A.; Barchiesi, F.; Cuenca-Estrella, M.; Fothergill, A.; Pfaller, M.A.; Rinaldi, M.; Rodriguez-Tudela, J.L.; Verweij, P.E.

    2005-01-01

    A multicenter (six-center) study evaluated the performance (interlaboratory reproducibility, compatibility with reference methods, and categorical agreement) of 24-h visual and 48-h spectrophotometric MICs. MICs of fluconazole, itraconazole, voriconazole, and posaconazole were compared to reference

  15. Antidiabetic activities of ethanol extract of dry matters of culture broth of Coriolus versiolor in submerged culture

    Directory of Open Access Journals (Sweden)

    Zuofa Zhang

    2011-08-01

    Full Text Available The study aimed to investigate the antihyperglycemic and antilipidperoxidative effects of ethanol extract of the dry matter from culture broth of Coriolus versicolor (ECBC in streptozotocin-induced diabetes mice. Blood glucose level, insulin level, total cholesterol (TC, triglyceride (TG, low density lipoprotein-cholesterol(LDL-C, high density lipoprotein -cholesterol (HDL-C in serum and reduced glutathione level (GSH, lipid peroxidation, glycogen, antioxidant enzymes in liver were evaluated. Moreover, histopathological observation was conducted. Streptozotocin treatment (150 mg/kg body weight induced the decrease of GSH level, antioxidant enzymes activities, glycogen content in liver, HDL-C content and insulin level in serum, accompanied by the elevation of the lipid peroxidation in liver, serum blood glucose level, contents of TC, TG and LDL-C. Treatment with ECBC restored the changes in the above parameters up to the basal level. The protective effects were further supported by the attenuation of the degree of pancreas damage in ECBC treated mice.

  16. Comparison of different options for harvest of a therapeutic protein product from high cell density yeast fermentation broth.

    Science.gov (United States)

    Wang, Alice; Lewus, Rachael; Rathore, Anurag S

    2006-05-05

    Recovery of therapeutic protein from high cell density yeast fermentations at commercial scale is a challenging task. In this study, we investigate and compare three different harvest approaches, namely centrifugation followed by depth filtration, centrifugation followed by filter-aid enhanced depth filtration, and microfiltration. This is achieved by presenting a case study involving recovery of a therapeutic protein from Pichia pastoris fermentation broth. The focus of this study is on performance of the depth filtration and the microfiltration steps. The experimental data has been fitted to the conventional models for cake filtration to evaluate specific cake resistance and cake compressibility. In the case of microfiltration, the experimental data agrees well with flux predicted by shear induced diffusion model. It is shown that, under optimal conditions, all three options can deliver the desired product recovery ( >80%), harvest time ( process development time required, capital cost, consumable cost, ease of scale-ability and process robustness. It is recommended that these be kept under consideration when making a final decision on a harvesting approach.

  17. Two-stage pervaporation process for effective in situ removal acetone-butanol-ethanol from fermentation broth.

    Science.gov (United States)

    Cai, Di; Hu, Song; Miao, Qi; Chen, Changjing; Chen, Huidong; Zhang, Changwei; Li, Ping; Qin, Peiyong; Tan, Tianwei

    2017-01-01

    Two-stage pervaporation for ABE recovery from fermentation broth was studied to reduce the energy cost. The permeate after the first stage in situ pervaporation system was further used as the feedstock in the second stage of pervaporation unit using the same PDMS/PVDF membrane. A total 782.5g/L of ABE (304.56g/L of acetone, 451.98g/L of butanol and 25.97g/L of ethanol) was achieved in the second stage permeate, while the overall acetone, butanol and ethanol separation factors were: 70.7-89.73, 70.48-84.74 and 9.05-13.58, respectively. Furthermore, the theoretical evaporation energy requirement for ABE separation in the consolidate fermentation, which containing two-stage pervaporation and the following distillation process, was estimated less than ∼13.2MJ/kg-butanol. The required evaporation energy was only 36.7% of the energy content of butanol. The novel two-stage pervaporation process was effective in increasing ABE production and reducing energy consumption of the solvents separation system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Biofilm formation by Staphylococcus aureus from food contact surfaces in a meat-based broth and sensitivity to sanitizers

    Directory of Open Access Journals (Sweden)

    Evandro Leite de Souza

    2014-01-01

    Full Text Available This study assessed the capacity of adhesion, the detachment kinetic and the biofilm formation by Staphylococcus aureus isolated from food services on stainless steel and polypropylene surfaces (2 x 2 cm when cultivated in a meat-based broth at 28 and 7 ºC. It was also to study the efficacy of the sanitizers sodium hypochlorite (250 mg/L and peracetic acid (30 mg/L in inactivating the bacterial cells in the preformed biofilm. S. aureus strains adhered in high numbers regardless the assayed surface kind and incubation temperature over 72 h. Cells detachment of surfaces revealed high persistence over the incubation period. Number of cells needed for biofilm formation was noted at all experimental systems already after 3 days. Peracetic acid and sodium hypochlorite were not efficient in completely removing the cells of S. aureus adhered on polypropylene and stainless steel surfaces. From these results, the assayed strains revealed high capacity to adhere and form biofilm on polypropylene and stainless steel surfaces under different growth conditions. Moreover, the cells in biofilm matrix were resistant for total removal when submitted to the exposure to sanitizers.

  19. Development of an Antimicrobial Susceptibility Testing Method Suitable for Performing During Space Flight

    Science.gov (United States)

    Jorgensen, James H.; Skweres, Joyce A.; Mishra S. K.; McElmeel, M. Letticia; Maher, Louise A.; Mulder, Ross; Lancaster, Michael V.; Pierson, Duane L.

    1997-01-01

    Very little is known regarding the affects of the microgravity environment of space flight upon the action of antimicrobial agents on bacterial pathogens. This study was undertaken to develop a simple method for conducting antibacterial susceptibility tests during a Space Shuttle mission. Specially prepared susceptibility test research cards (bioMerieux Vitek, Hazelwood, MO) were designed to include 6-11 serial two-fold dilutions of 14 antimicrobial agents, including penicillins, cephalosporins, a Beta-lactamase inhibitor, vancomycin, erythromycin, tetracycline, gentamicin, ciprofloxacin, and trimethoprim/sulfamethoxazole. Minimal inhibitory concentrations (MICS) of the drugs were determined by visual reading of color endpoints in the Vitek research cards made possible by incorporation of a colorimetric growth indicator (alamarBlue(Trademark), Accumed International, Westlake, OH). This study has demonstrated reproducible susceptibility results when testing isolates of Staphylococcus aurezis, Group A Streptococcus, Enterococcusfaecalis, Escherichia coli (beta-lactamase positive and negative strains), Klebsiella pneumoniae, Enterobacter cloacae, and Pseudomoiias aeruginosa. In some instances, the MICs were comparable to those determined using a standard broth microdilution method, while in some cases the unique test media and format yielded slightly different values, that were themselves reproducible. The proposed in-flight experiment will include inoculation of the Vitek cards on the ground prior to launch of the Space Shuttle, storage of inoculated cards at refrigeration temperature aboard the Space Shuttle until experiment initiation, then incubation of the cards for 18-48 h prior to visual interpretation of MICs by the mission's astronauts. Ground-based studies have shown reproducible MICs following storage of inoculated cards for 7 days at 4-8 C to accommodate the mission's time schedule and the astronauts' activities. For comparison, ground-based control

  20. Comparison of EUCAST and CLSI Reference Microdilution MICs of Eight Antifungal Compounds for Candida auris and Associated Tentative Epidemiological Cutoff Values.

    Science.gov (United States)

    Arendrup, M C; Prakash, Anupam; Meletiadis, Joseph; Sharma, Cheshta; Chowdhary, Anuradha

    2017-06-01

    Candida auris is an emerging multidrug-resistant yeast. So far, all but two susceptibility testing studies have examined ≤50 isolates, mostly with the CLSI method. We investigated CLSI and EUCAST MICs for 123 C. auris isolates and eight antifungals and evaluated various methods for epidemiological cutoff (ECOFF) determinations. MICs (in milligrams per liter) were determined using CLSI method M27-A3, and the EUCAST E.Def 7.3. ANOVA analysis of variance with Bonferroni's multiple-comparison test and Pearson analysis were used on log2 MICs (significance at P values of CLSI and EUCAST MIC distributions were wide, with several peaks for all compounds except amphotericin B, suggesting possible acquired resistance. Modal MIC, geometric MIC, MIC50, and MIC90 values were ≤1 2-fold dilutions apart, and no significant differences were found. The quantitative agreement was best for amphotericin B (80%/97% within ±1/±2 dilutions) and lowest for isavuconazole and anidulafungin (58%/76% to 75% within ±1/±2 dilutions). We found that 90.2%/100% of the isolates were amphotericin B susceptible based on CLSI/EUCAST methods, respectively (i.e., with MICs of ≤1 mg/liter), and 100%/97.6% were fluconazole nonsusceptible by CLSI/EUCAST (MICs > 2). The ECOFFs (in milligrams per liter) were similar across the three different methods for itraconazole (ranges for CLSI/EUCAST, 0.25 to 0.5/0.5 to 1), posaconazole (0.125/0.125 to 0.25), amphotericin B (0.25 to 0.5/1 to 2), micafungin (0.25 to 0.5), and anidulafungin (0.25 to 0.5/0.25 to 1). In contrast, the estimated ECOFFs were dependent on the method applied for voriconazole (1 to 32) and isavuconazole (0.125 to 4). CLSI and EUCAST MICs were remarkably similar and confirmed uniform fluconazole resistance and variable acquired resistance to the other agents. Copyright © 2017 American Society for Microbiology.

  1. Comparative evaluation of three chromogenic media combined with broth enrichment and the real-time PCR-based Xpert MRSA assay for screening of methicillin-resistant Staphylococcus aureus in nasal swabs.

    Science.gov (United States)

    Lee, Seungok; Park, Yeon-Joon; Park, Kang-Gyun; Jekarl, Dong Wook; Chae, Hyojin; Yoo, Jin-Kyung; Seo, Sin Won; Choi, Jung Eun; Lim, Jung Hye; Heo, Seon Mi; Seo, Ju Hee

    2013-07-01

    We evaluated the performance of three chromogenic media (Brilliance agar I [Oxoid, UK], Brilliance agar II [Oxoid], and ChromID MRSA [Biomérieux, France]) combined with broth enrichment and the Xpert MRSA assay for screening of methicillin-resistant Staphylococcus aureus (MRSA). We obtained 401 pairs of duplicate nasal swabs from 321 patients. One swab was suspended overnight in tryptic soy broth; 50-µL aliquots of suspension were inoculated on the three chromogenic media. Brilliance agar I and II were examined after 24 hr, and ChromID MRSA, after 24 and 48 hr. The paired swab was processed directly using real-time PCR-based Xpert MRSA assay. True positives, designated as MRSA growth in any of the culture media, were detected with the prevalence of 17% in our institution. We report the sensitivity, specificity, positive predictive value, and negative predictive value of MRSA growth as follows: 92.3%, 94.0%, 75.9%, and 98.4% in Brilliance agar I (24 hr); 92.7%, 97.9%, 90.0%, and 98.5% in Brilliance agar II (24 hr); 95.6%, 95.8%, 82.3%, and 99.1% in ChromID MRSA (24 hr); 100%, 92.5%, 73.1%, and 100% in ChromID MRSA (48 hr); 92.6%, 96.7%, 85.1%, and 98.5% in Xpert MRSA assay. The agreement between the enriched culture and Xpert MRSA assay was 96.0%. Three chromogenic culture media combined with enrichment and Xpert MRSA assay demonstrated similar capabilities in MRSA detection. The Xpert MRSA assay yielded results comparable to those of culture methods, saving 48-72 hr, thus facilitating earlier detection of MRSA in healthcare settings.

  2. Partial purification of saccharifying and cell wall-hydrolyzing enzymes from malt in waste from beer fermentation broth.

    Science.gov (United States)

    Khattak, Waleed Ahmad; Kang, Minkyung; Ul-Islam, Mazhar; Park, Joong Kon

    2013-06-01

    A number of hydrolyzing enzymes that are secreted from malt during brewing, including cell wall-hydrolyzing, saccharide-hydrolyzing, protein-degrading, lipid-hydrolyzing, and polyphenol and thiol-hydrolyzing enzymes, are expected to exist in an active form in waste from beer fermentation broth (WBFB). In this study, the existence of these enzymes was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis, after which enzyme extract was partially purified through a series of purification steps. The hydrolyzing enzyme activity was then measured under various conditions at each purification step using carboxymethyl cellulose as a substrate. The best hydrolyzing activities of partially purified enzymes were found at pH 4.5 and 50 °C in a citrate buffer system. The enzymes showed highest thermal stability at 30 °C when exposed for prolonged time. As the temperature increased gradually from 25 to 70 °C, yeast cells in the chemically defined medium with enzyme extract lost their cell wall and viability earlier than those without enzyme extract. Cell wall degradation and the release of cell matrix into the culture media at elevated temperature (45-70 °C) in the presence of enzyme extract were monitored through microscopic pictures. Saccharification enzymes from malt were relatively more active in the original WBFB than supernatant and diluted sediments. The presence of hydrolyzing enzymes from malt in WBFB is expected to play a role in bioethanol production using simultaneous saccharification and fermentation without the need for additional enzymes, nutrients, or microbial cells via a cell-free enzyme system.

  3. Augmentation of antibiotic activity by low-frequency electric and electromagnetic fields examining Staphylococcus aureus in broth media.

    Science.gov (United States)

    Matl, F D; Obermeier, A; Zlotnyk, J; Friess, W; Stemberger, A; Burgkart, R

    2011-07-01

    Systemic treatment of biomaterial-associated bacterial infections with high doses of antibiotics is an established therapeutic concept. The purpose of this in vitro study was to determine the influence of magnetic, electromagnetic, and electric fields on gentamicin-based, antibiotic therapy. It has been previously reported that these fields are successful in the treatment of bone healing and reducing osteitis in infected tibia-pseudarthroses. Four separate experimental setups were used to expose bacterial cultures of Staphylococcus aureus both in Mueller-Hinton broth (MHB) and on Mueller-Hinton agar (MHA), in the presence of gentamicin, to (1) a low-frequency magnetic field (MF) 20 Hz, 5 mT; (2) a low-frequency MF combined with an additional alternating electric field (MF + EF) 20 Hz, 5 mT, 470 mV/cm; (3) a sinusoidal alternating electric field (EF AC) 20 Hz, 470 mV/cm; and (4) a direct current electric field (EF DC) 588 mV/cm. No significant difference between samples and controls was detected on MHA. However, in MHB each of the four fields applied showed a significant growth reduction of planktonically grown Staphylococcus aureus in the presence of gentamicin between 32% and 91% within 24 h of the experiment. The best results were obtained by a direct current EF, decreasing colony-forming units (CFU)/ml more than 91%. The application of electromagnetic fields in the area of implant and bone infections could offer new perspectives in antibiotic treatment and antimicrobial chemotherapy. Copyright © 2011 Wiley-Liss, Inc.

  4. Direct recovery of Bacillus subtilis xylanase from fermentation broth with an alcohol/salt aqueous biphasic system.

    Science.gov (United States)

    Ng, Hui Suan; Chai, Cindy Xin Yi; Chow, Yin Hui; Loh, Wai Leng Carmen; Yim, Hip Seng; Tan, Joo Shun; Lan, John Chi-Wei

    2018-01-12

    Xylanase enzyme degrades linear polysaccharide β-1,4 xylan and the hemicellulose of the plant cell wall. There is a growing demand in finding a cost-effective alternative for industrial scale production of xylanase with high purity for pharmaceutical applications. In this study, an alcohol/salt aqueous biphasic system (ABS) was adopted to recover xylanase from the Bacillus subtilis fermentation broth. The effects of several ABS parameters such as types and concentrations of alcohols and salts (i.e., sulphate, phosphate, and citrate), amount of crude loading and pH of the system on the recovery of xylanase were investigated. Partition coefficient of xylanase (KE), selectivity (S) and yield (YT) of xylanase in top phase of the ABS were measured. Highest KE (6.58 ± 0.05) and selectivity (4.84 ± 0.33) were recorded in an ABS of pH 8 composed of 26% (w/w) 1-propanol, 18% (w/w) ammonium sulphate. High YT of 71.88% ± 0.15 and a purification fold (PFT) of 5.74 ± 0.33 were recorded with this optimum recovery of xylanase using alcohol/salt ABS. The purity of xylanase recovered was then qualitatively verified with sodium dodecyl sulphate (SDS) gel electrophoresis. The SDS profile revealed the purified xylanase was successfully obtained in the top phase of the one-step 1-propanol/sulphate ABS with a distinct single band. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. Pea Broth Enhances the Biocontrol Efficacy of Lysobacter capsici AZ78 by Triggering Cell Motility Associated with Biogenesis of Type IV Pilus.

    Science.gov (United States)

    Tomada, Selena; Puopolo, Gerardo; Perazzolli, Michele; Musetti, Rita; Loi, Nazia; Pertot, Ilaria

    2016-01-01

    Bacterial cells can display different types of motility, due to the presence of external appendages such as flagella and type IV pili. To date, little information on the mechanisms involved in the motility of the Lysobacter species has been available. Recently, L. capsici AZ78, a biocontrol agent of phytopathogenic oomycetes, showed the ability to move on jellified pea broth. Pea broth medium improved also the biocontrol activity of L. capsici AZ78 against Plasmopara viticola under greenhouse conditions. Noteworthy, the quantity of pea residues remaining on grapevine leaves fostered cell motility in L. capsici AZ78. Based on these results, this unusual motility related to the composition of the growth medium was investigated in bacterial strains belonging to several Lysobacter species. The six L. capsici strains tested developed dendrite-like colonies when grown on jellified pea broth, while the development of dendrite-like colonies was not recorded in the media commonly used in motility assays. To determine the presence of genes responsible for biogenesis of the flagellum and type IV pili, the genome of L. capsici AZ78 was mined. Genes encoding structural components and regulatory factors of type IV pili were upregulated in L. capsici AZ78 cells grown on the above-mentioned medium, as compared with the other tested media. These results provide new insight into the motility mechanism of L. capsici members and the role of type IV pili and pea compounds on the epiphytic fitness and biocontrol features of L. capsici AZ78.

  6. Pea broth enhances the biocontrol efficacy of Lysobacter capsici AZ78 by triggering cell motility associated with biogenesis of type IV pilus

    Directory of Open Access Journals (Sweden)

    Selena Tomada

    2016-07-01

    Full Text Available Bacterial cells can display different types of motility, due to the presence of external appendages such as flagella and type IV pili. To date, little information on the mechanisms involved in the motility of the Lysobacter species has been available. Recently, L. capsici AZ78, a biocontrol agent of phytopathogenic oomycetes, showed the ability to move on jellified pea broth. Pea broth medium improved also the biocontrol activity of L. capsici AZ78 against Plasmopara viticola under greenhouse conditions. Noteworthy, the quantity of pea residues remaining on grapevine leaves fostered cell motility in L. capsici AZ78. Based on these results, this unusual motility related to the composition of the growth medium was investigated in bacterial strains belonging to several Lysobacter species. The six L. capsici strains tested developed dendrite-like colonies when grown on jellified pea broth, while the development of dendrite-like colonies was not recorded in the media commonly used in motility assays. To determine the presence of genes responsible for biogenesis of the flagellum and type IV pili, the genome of L. capsici AZ78 was mined. Genes encoding structural components an d regulatory factors of type IV pili were upregulated in L. capsici AZ78 cells grown on the above-mentioned medium, as compared with the other tested media. These results provide new insight into the motility mechanism of L. capsici members and the role of type IV pili and pea compounds on the epiphytic fitness and biocontrol features of L. capsici AZ78.

  7. Evaluation of different buffered peptone water (BPW) based enrichment broths for detection of Gram-negative foodborne pathogens from various food matrices.

    Science.gov (United States)

    Margot, H; Zwietering, M H; Joosten, H; O'Mahony, Emer; Stephan, R

    2015-12-02

    This study evaluated the effects of changing the composition of the pre-enrichment medium buffered peptone water (BPW) on the growth of stressed and unstressed Gram-negative foodborne pathogens in a one-broth enrichment strategy. BPW supplemented with an available iron source and sodium pyruvate, along with low levels of 8-hydroxyquinoline and sodium deoxycholate (BPW-S) improved the recovery of desiccated Cronobacter spp. from powdered infant formula. Growth of Salmonella and STEC was comparable in all BPW variants tested for different food matrices. In products with high levels of Gram-negative background flora (e.g. sprouts), the target organisms could not be reliably detected by PCR in any of the BPW variants tested unless the initial level exceeded 10(3) cfu/10 g of sprouts. Based on these results we suggest BPW-S for a one-broth enrichment strategy of stressed Gram-negative foodborne pathogens from dry products. However, a one-broth enrichment strategy based on BPW variants tested in this evaluation is not recommended for produce with a high level of Gram-negative background flora due to very high detection limits. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Ultrasonic disruption of fungal mycelia for efficient recovery of polysaccharide-protein complexes from viscous fermentation broth of a medicinal fungus.

    Science.gov (United States)

    Cheung, Yi-Ching; Liu, Xing-Xun; Wang, Wing-Qiang; Wu, Jian-Yong

    2015-01-01

    High-intensity ultrasound (US) was applied to facilitate the extraction of intracellular and extracellular polysaccharide-protein complexes (PSPs) from the viscous mycelial fermentation broth of a medicinal fungus Cordyceps sinensis Cs-HK1. The US treatment caused the disruption of fungal mycelia, a dramatic reduction of the apparent broth viscosity, and the release of intracellular products into the liquid medium. The degree of mycelium disruption and the rate of intracellular product release were dependent on US power intensity, treatment period and biomass concentration of broth. The extraction or release kinetics of total water-soluble products and PSPs (yield Y versus time t) under the effect of US was fitted closely to the Elovich model Y=Yo+Y1 lnt and parabolic model Y=Yo+Y1t(½), respectively. Another interesting effect of the US treatment was a notable increase in the antioxidant cytoprotective activity of PSP against H2O2 induced cell death. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Interlaboratory reproducibility of Etest amphotericin B and caspofungin yeast susceptibility testing and comparison with the CLSI method.

    Science.gov (United States)

    Ranque, S; Lachaud, L; Gari-Toussaint, M; Michel-Nguyen, A; Mallié, M; Gaudart, J; Bertout, S

    2012-07-01

    This study aimed to assess the interlaboratory reproducibility at four university hospital laboratories in the southeast region of France of the Etest technique for the determination of caspofungin (CAS) and amphotericin B (AMB) MICs and to compare it to the CLSI broth microdilution reference method. Consecutive clinical yeast isolates (n = 198) were included in the study. AMB and CAS MICs were read at 24 and 48 h. Interlaboratory reproducibility was estimated by using (i) an intraclass correlation coefficient (ICC), (ii) essential agreement (EA), and (iii) categorical agreement (CA). For Etest interlaboratory reproducibility for CAS, ICCs were 0.80 (95% confidence interval [CI], 0.76 to 0.84) and 0.81 (95% CI, 0.77 to 0.85) at 24 and 48 h, respectively. For AMB, the ICCs were 0.51 (95% CI, 0.43 to 0.58) and 0.69 (95% CI, 0.63 to 0.74) at 24 and 48 h, respectively. At 48 h, the between-center EAs ranged from 94.4 to 99.0% for both antifungals. For the comparison of the CLSI method and the Etest, the between-technique ICCs were 0.69 (95% CI, 0.63 to 0.74) and 0.62 (95% CI, 0.55 to 0.68) for CAS and AMB, respectively. The EAs ranged from 76.5 to 98.5% for CAS and from 90.3 to 97.4% for AMB according to the centers. CAs ranged from 87.9% to 91.4%, with four very major errors for 2 strains (1 Candida albicans strain and 1 Candida krusei strain), for CAS and from 97.5 to 99.5%, with four major errors, for AMB. In conclusion, the Etest showed a good interlaboratory reproducibility and a good correlation with the CLSI technique. It is well suited for the routine clinical laboratory and can thus be used to monitor clinical yeast isolates' in vitro susceptibilities in this setting.

  10. Activity of a long-acting echinocandin, CD101, determined using CLSI and EUCAST reference methods, against Candida and Aspergillus spp., including echinocandin- and azole-resistant isolates.

    Science.gov (United States)

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

    2016-10-01

    The objective of this study was to evaluate the in vitro activity of CD101, a novel echinocandin with a long serum elimination half-life, and comparator (anidulafungin and caspofungin) antifungal agents against a collection of Candida and Aspergillus spp. isolates. CD101 and comparator agents were tested against 106 Candida spp. and 67 Aspergillus spp. isolates, including 27 isolates of Candida harbouring fks hotspot mutations and 12 itraconazole non-WT Aspergillus, using CLSI and EUCAST reference susceptibility broth microdilution (BMD) methods. Against WT and fks mutant Candida albicans, Candida glabrata and Candida tropicalis, the activity of CD101 [MIC90 = 0.06, 0.12 and 0.03 mg/L, respectively (CLSI method values)] was comparable to that of anidulafungin (MIC90 = 0.03, 0.12 and 0.03 mg/L, respectively) and caspofungin (MIC90 = 0.12, 0.25 and 0.12 mg/L, respectively). WT Candida krusei isolates were very susceptible to CD101 (MIC = 0.06 mg/L). CD101 activity (MIC50/90 = 1/2 mg/L) was comparable to that of anidulafungin (MIC50/90 = 2/2 mg/L) against Candida parapsilosis. CD101 (MIC mode = 0.06 mg/L for C. glabrata) was 2- to 4-fold more active against fks hotspot mutants than caspofungin (MIC mode = 0.5 mg/L). CD101 was active against Aspergillus fumigatus, Aspergillus terreus, Aspergillus niger and Aspergillus flavus (MEC90 range = ≤0.008-0.03 mg/L). The essential agreement between CLSI and EUCAST methods for CD101 was 92.0%-100.0% among Candida spp. and 95.0%-100.0% among Aspergillus spp. The activity of CD101 is comparable to that of other members of the echinocandin class for the prevention and treatment of serious fungal infections. Similar results for CD101 activity versus Candida and Aspergillus spp. may be obtained with either CLSI or EUCAST BMD methods. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

  11. Método de difusión con discos para la determinación de sensibilidad a fluconazol en aislamientos de Candida spp Disk diffusion method for fluconazole susceptibility testing of Candida spp. isolates

    Directory of Open Access Journals (Sweden)

    L. Rodero

    2006-09-01

    Full Text Available Se estudiaron 1193 aislamientos clínicos para estandarizar y evaluar un método de difusión con discos de fluconazol de lectura visual, que permita detectar levaduras sensibles al antifúngico. Las especies analizadas fueron: Candida albicans (n=584, Candida parapsilosis (n=196, Candida tropicalis (n=200, Candida glabrata (n=113, Candida krusei (n=50, Candida spp. y otras levaduras oportunistas (n=50. Los discos fueron manufacturados en el INEI-ANLIS "Dr. Carlos G. Malbrán". Se midieron los halos de inhibición del crecimiento producidos por fluconazol y la concentración inhibitoria mínima (CIM por el método de referencia M27-A2 modificado por EUCAST. Se establecieron los valores de corte del método de difusión en: ≥16 mm para levaduras sensibles a fluconazol (CIM ≤ 8 µg/ml, entre 9 y 15 mm para sensibles dependientes de la dosis (CIM = 16-32 mg/ml y ≤ 8 mm para resistentes (CIM ≥ 64 µg/ml. El método de difusión tuvo 94,7% de concordancia con el de referencia, con 0,2% de errores very major y 0,3% de errores major. La reproducibilidad inter e intralaboratorio fue muy buena. Para detectar aislamientos sensibles a fluconazol, este método resulta confiable y de bajo costo; sin embargo, es conveniente que los aislamientos con halos ≤ 15 mm sean reevaluados por el método de referencia.In order to standardize and evaluate a disk diffusion method with visual reading to detect in vitro fluconazole susceptibility of yeast, 1193 clinical isolates were tested. These included 584 Candida albicans, 196 Candida parapsilosis, 200 Candida tropicalis, 113 Candida glabrata, 50 Candida krusei and 50 Candida spp. and other opportunistic yeasts. The disks were manufactured in the INEI-ANLIS "Dr. Carlos G. Malbrán". The disk diffusion method results were compared to MIC results obtained by the reference CLSI M27-A2 broth microdilution method modified by EUCAST. The interpretative breakpoints for in vitro susceptibility testing of fluconazole

  12. Evaluation of the Rapid Polymyxin NP Test for Polymyxin B Resistance Detection Using Enterobacter cloacae and Enterobacter aerogenes Isolates.

    Science.gov (United States)

    Simar, Shelby; Sibley, Diane; Ashcraft, Deborah; Pankey, George

    2017-10-01

    Polymyxin resistance is an increasing problem worldwide. Currently, determining susceptibility to polymyxins is problematic and lengthy. Polymyxins diffuse poorly into agar, potentially giving inaccurate disk diffusion and Etest results. A rapid screening test (2 h) for the detection of polymyxin resistance in Enterobacteriaceae, developed by P. Nordmann and L. Poirel (rapid polymyxin NP test) in 2016, detects glucose metabolization in the presence of polymyxin E (PE) and PB via pH-induced color change. The sensitivity and specificity were 99.3 and 95.4%, respectively, with results obtained in ≤2 h. Our goal was to evaluate this test using PB against larger numbers of Enterobacter A total of 143 nonduplicate Enterobacter isolates (102 E. cloacae complex, 41 E. aerogenes) were tested, including 136 collected from Ochsner Health System patients from March to May 2016 and 7 previously determined PB-resistant E. cloacae isolates from JMI Laboratories. MICs were determined via broth microdilution. For the rapid polymyxin NP test, a color change from orange to yellow is positive; a weak/no color change is deemed negative after 4 h. Of 143 Enterobacter isolates, 25 were determined to be PB resistant by broth microdilution (MIC > 2 μg/ml), including all 7 JMI isolates. Of these 25, 7 were positive by the rapid polymyxin NP test (included 3/7 JMI isolates). All 118 isolates determined to be PB susceptible by broth microdilution were NP test negative. The sensitivity and specificity for the rapid polymyxin NP test were 25 and 100%, respectively, compared to broth microdilution. Although the rapid polymyxin NP test is a much faster method (2 to 4 h) for polymyxin resistance determination compared to broth microdilution (16 to 20 h), our study indicates that it may be subject to limitations when testing Enterobacter. Copyright © 2017 American Society for Microbiology.

  13. Antimicrobial susceptibilities of Lactobacillus, Pediococcus and Lactococcus human isolates and cultures intended for probiotic or nutritional use

    National Research Council Canada - National Science Library

    Klare, Ingo; Konstabel, Carola; Werner, Guido; Huys, Geert; Vankerckhoven, Vanessa; Kahlmeter, Gunnar; Hildebrandt, Bianca; Müller-Bertling, Sibylle; Witte, Wolfgang; Goossens, Herman

    2007-01-01

    ... susceptibilities by broth microdilution using LAB susceptibility test medium (LSM). Tentative ECOFFs were defined according to the recommendations of the European Committee on Antimicrobial Susceptibility Testing...

  14. Telavancin activity when tested by a revised susceptibility testing method against uncommonly isolated Gram-positive pathogens responsible for documented infections in hospitals worldwide (2011-2013).

    Science.gov (United States)

    Mendes, Rodrigo E; Sader, Helio S; Flamm, Robert K; Farrell, David J; Jones, Ronald N

    2015-03-01

    The broth microdilution method for telavancin susceptibility testing was revised and now utilises DMSO as solvent for stock solution preparation and diluent for stock solution dilution, following CLSI guidelines for water-insoluble agents. The revised method also incorporates polysorbate 80 in the test medium to mitigate drug binding to plastics. This revised methodology provides more accurate and reproducible MIC determinations, which results in values lower than the previously established method. This study was conducted to re-establish telavancin potencies and susceptibility profiles (using updated interpretive criteria) against a collection of uncommon clinical pathogens (3821 isolates). Telavancin showed MIC50 values of 0.06mg/L against tested staphylococcal species (MIC50/90, 0.03/0.06mg/L; 98.1-100.0% susceptible), with lower results for Staphylococcus hominis (MIC50, ≤0.015mg/L), Staphylococcus lugdunensis (MIC50, ≤0.015mg/L) and Staphylococcus simulans (MIC50, 0.03mg/L). Vancomycin (MIC50, 1mg/L), daptomycin (MIC50, 0.12-1mg/L) and linezolid (MIC50, 0.25-1mg/L) had MIC50 results at least four-fold higher than telavancin against CoNS. Streptococci (99.2-100.0% susceptible) displayed telavancin MIC50 values of ≤0.015-0.03mg/L. Vancomycin (MIC50, 0.25-0.5mg/L) and linezolid (MIC50, 0.5-1mg/L) had higher MIC50 results against streptococci, whilst daptomycin MIC50 values varied from ≤0.06mg/L to 0.5mg/L. Micrococcus, Listeria and Corynebacterium spp. were inhibited by telavancin at ≤0.015, ≤0.03 and ≤0.06mg/L, respectively. Telavancin exhibited potent in vitro activity against this collection, greater than comparators (daptomycin, linezolid, vancomycin). This study provides new baseline MIC results for telavancin and confirms the spectrum and potency of telavancin against less commonly encountered Gram-positive species. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. The Influence of Different Strategies for the Saccharification of the Banana Plant Pseudostem and the Detoxification of Concentrated Broth on Bioethanol Production.

    Science.gov (United States)

    de Souza, Elias Luiz; Sellin, Noeli; Marangoni, Cintia; Souza, Ozair

    2017-11-01

    Pseudostem of the Musa cavendishii banana plant was submitted to chemical pretreatments with acid (H2SO4 2%, 120 °C, 15 min) and with alkali (NaOH 3%, 120 °C, 15 min), saccharified by commercial enzymes Novozymes® (Cellic CTec2 and HTec2). The influences of the pretreatments on the degradation of the lignin, cellulose and hemicellulose, porosity of the surface, particle crystallinity, and yield in reducing sugars after saccharification (Y RS), were established. Different concentrations of biomass (70 and 100 g/L in dry matter (dm)), with different physical differences (dry granulated, crushed wet bagasse, and whole pseudostem), were used. The broth with the highest Y RS among the different strategies tested was evaporated until the concentration of reducing sugars (RS) was to the order of 100 g/L and fermented, with and without prior detoxification with active carbon. Fermentation was carried out in Erlenmeyer flasks, at 30 °C, initial pH 5.0, and 120 rpm. In comparison to the biomass without chemical pretreatment and to the biomass pretreated with NaOH, the acid pretreatment of 70 g/L of dry granulated biomass enabled greater digestion of hemicellulose, lower index of cellulose crystallinity, and higher Y RS (45.8 ± 0.7%). The RS increase in fermentation broth to 100 g/L, with posterior detoxification, presented higher productivity ethanol (Q P = 1.44 ± 0.02 g/L/h) with ethanol yield (Y P/RS) of 0.41 ± 0.02 g/g. The value of Q P was to the order of 75% higher than Q P obtained with the same broth without prior detoxification.

  16. Growth and inactivation of Salmonella enterica and Listeria monocytogenes in broth and validation in ground pork meat during simulated home storage abusive temperature and home pan-frying

    Directory of Open Access Journals (Sweden)

    Xiang eWang

    2015-10-01

    Full Text Available Ground pork meat with natural microbiota and inoculated with low initial densities (1-10 or 10-100 CFU/g of Salmonella enterica or Listeria monocytogenes was stored under abusive temperature at 10°C and thermally treated by a simulated home pan-frying procedure. The growth and inactivation characteristics were also evaluated in broth. In ground pork meat, the population of S. enterica increased by less than one log after 12-days of storage at 10°C, whereas L. monocytogenes increased by 2.3 to 2.8 log units. No unusual intrinsic heat resistance of the pathogens was noted when tested in broth at 60°C although shoulders were observed on the inactivation curves of L. monocytogenes. After growth of S. enterica and L. monocytogenes at 10°C for 5 days to levels of 1.95 log CFU/g and 3.10 log CFU/g, respectively, in ground pork meat, their inactivation in the burger subjected to a simulated home pan-frying was studied. After thermal treatment S. enterica was undetectable but L. monocytogenes was recovered in three out of six of the 25 g burger samples. Overall, the present study shows that data on growth and inactivation of broths are indicative but may underestimate as well as overestimate behavior of pathogens and thus need confirmation in food matrix conditions to assess food safety in reasonably foreseen abusive conditions of storage and usual home pan-frying of of meat burgers in Belgium.

  17. Effects of the Essential Oil from Origanum vulgare L. on Survival of Pathogenic Bacteria and Starter Lactic Acid Bacteria in Semihard Cheese Broth and Slurry.

    Science.gov (United States)

    de Souza, Geany Targino; de Carvalho, Rayssa Julliane; de Sousa, Jossana Pereira; Tavares, Josean Fechine; Schaffner, Donald; de Souza, Evandro Leite; Magnani, Marciane

    2016-02-01

    This study assessed the inhibitory effects of the essential oil from Origanum vulgare L. (OVEO) on Staphylococcus aureus, Listeria monocytogenes, and a mesophilic starter coculture composed of lactic acid bacteria (Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris) in Brazilian coalho cheese systems. The MIC of OVEO was 2.5 μl/ml against both S. aureus and L. monocytogenes and 0.6 μl/ml against the tested starter coculture. In cheese broth containing OVEO at 0.6 μl/ml, no decrease in viable cell counts (VCC) of both pathogenic bacteria was observed, whereas the initial VCC of the starter coculture decreased approximately 1.0 log CFU/ml after 24 h of exposure at 10°C. OVEO at 1.25 and 2.5 μl/ml caused reductions of up to 2.0 and 2.5 log CFU/ml in S. aureus and L. monocytogenes, respectively, after 24 h of exposure in cheese broth. At these same concentrations, OVEO caused a greater decrease of initial VCC of the starter coculture following 4 h of exposure. Higher concentrations of OVEO were required to decrease the VCC of all target bacteria in semisolid coalho cheese slurry compared with cheese broth. The VCC of Lactococcus spp. in coalho cheese slurry containing OVEO were always lower than those of pathogenic bacteria under the same conditions. These results suggest that the concentrations of OVEO used to control pathogenic bacteria in semihard cheese should be carefully evaluated because of its inhibitory effects on the growth of starter lactic acid cultures used during the production of the product.

  18. Incidence of Propionibacterium acnes in initially culture-negative thioglycollate broths-a prospective cohort study at a Danish University Hospital.

    Science.gov (United States)

    Kvich, L; Jensen, P Ø; Justesen, U S; Bjarnsholt, T

    2016-11-01

    The aim of this study was to prospectively investigate the incidence of Propionibacterium acnes in thioglycollate broths reported as culture-negative at the Department of Clinical Microbiology, Rigshospitalet, to evaluate whether 5 days of incubation was enough to find all relevant cases. Five hundred thioglycollate broths reported as culture-negative after 5 days were consecutively collected and incubated for at least a further 9 days (at least 14 days of incubation in total). Only tissue samples from sterile sites of the body (n = 298), bone tissue (n = 197) and foreign material (n = 5) were included in this study. Samples were divided into two groups: infected group and control group. This made it possible to compare findings between groups, thereby making it possible to estimate the level of true-positive findings and contamination. Samples from 296 participants were included in this study. After exclusion criteria were met, P. acnes was cultured from ten out of 151 patients (6.6%) in the infected group and from one out of 138 participants (0.7%) in the control group. This resulted in more findings of P. acnes in the infected group on day 14 than on day 5 (p 0.002). Furthermore, P. acnes was cultured more often from bone tissue and tissue surrounding foreign materials on day 14 than on day 5 (p 0.04). Clinical microbiology laboratories should consider incubating thioglycollate broths for at least 14 days to find all relevant cases of P. acnes, especially when it comes to bone tissue and tissue surrounding foreign materials. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  19. Same-Day Identification and Antimicrobial Susceptibility Testing of Bacteria in Positive Blood Culture Broths Using Short-Term Incubation on Solid Medium with the MicroFlex LT, Vitek-MS, and Vitek2 Systems.

    Science.gov (United States)

    Ha, Jihye; Hong, Sung Kuk; Han, Geum Hee; Kim, Myungsook; Yong, Dongeun; Lee, Kyungwon

    2018-05-01

    Early and appropriate antibiotic treatment improves the clinical outcome of patients with septicemia; therefore, reducing the turn-around time for identification (ID) and antimicrobial susceptibility test (AST) results is essential. We established a method for rapid ID and AST using short-term incubation of positive blood culture broth samples on solid media, and evaluated its performance relative to that of the conventional method using two rapid ID systems and a rapid AST method. A total of 254 mono-microbial samples were included. Positive blood culture samples were incubated on blood agar plates for six hours and identified by the MicroFlex LT (Bruker Daltonics) and Vitek-MS (bioMeriéux) systems, followed by AST using the Vitek2 System (bioMeriéux). The correct species-level ID rates were 82.3% (209/254) and 78.3% (199/254) for the MicroFlex LT and Vitek-MS platforms, respectively. For the 1,174 microorganism/antimicrobial agent combinations tested, the rapid AST method showed total concordance of 97.8% (1,148/1,174) with the conventional method, with a very major error rate of 0.5%, major error rate of 0.7%, and minor error rate of 1.0%. Routine implementation of this short-term incubation method could provide ID results on the day of blood culture-positivity detection and one day earlier than the conventional AST method. This simple method will be very useful for rapid ID and AST of bacteria from positive blood culture bottles in routine clinical practice.

  20. Comparison of two pre-enrichments broths for recovering Listeria spp. from salmon (Salmo salar) and salmon-trout (Oncorhynchus mykiss)

    OpenAIRE

    Vaz-Velho,Manuela; Duarte, Gabriela; Gibbs, Paul

    2001-01-01

    Low levels of occurrence of Listeria spp. in fresh salmon (Salmo_salar ) and salmon-trout (Oncorhynchus mykiss), may be related to the selectivity of the pre-enrichment broth recommended by ISO 11290-1. The purpose of this study was to compare the abilities of Fraser base (without supplements) and 0.1% (w/v) peptone water for recovering Listeria spp. from the fresh fish samples. Fifty-six fish were swabbed and the swabs placed in Fraser base and in 0.1% (w/v) peptone water. Samples were a...

  1. Detection of Burkholderia pseudomallei in Sputum using Selective Enrichment Broth and Ashdown’s Medium at Kampong Cham Provincial Hospital, Cambodia [v2; ref status: indexed, http://f1000r.es/5e9

    Directory of Open Access Journals (Sweden)

    Somary Nhem

    2015-05-01

    Full Text Available Melioidosis, infection caused by Burkholderia pseudomallei, is increasingly reported in Cambodia. We hypothesized that implementation of an enhanced sputum testing protocol in a provincial hospital diagnostic microbiology laboratory would increase detection of B. pseudomallei. We tested 241 sputum specimens that were deemed acceptable for culture, comparing culture in selective enrichment broth followed by sub-culture on Ashdown’s medium to standard culture methods. Two specimens (0.8% were positive for B. pseudomallei using the enhanced protocol whereas one specimen (0.4% was positive using standard methods. Given the low numbers of positive specimens, we could not conclusively determine the utility of the enhanced sputum testing protocol. However, the ramifications of identification of B. pseudomallei are substantial, and the benefit of the enhanced testing protocol may be more apparent in patients selected based on risk factors and clinical presentation. Promoting clinician awareness of the infection and encouraging utilization of diagnostic microbiology services are also likely to be important factors in facilitating identification of melioidosis.

  2. An evaluation of certain Salmonella detection methods in surface water.

    Science.gov (United States)

    Bernagozzi, M; Sacchetti, R; Polenta, L

    1996-11-01

    Two different procedures were employed for detecting Salmonella spp. in environmental water samples: a rapid method (enrichment in Salmosyst Broth and plating in Rambach Agar-Merck) and a longer assay (pre-enrichment in Buffered Peptone Water, enrichment in Selenite-Cistyne Broth and plating in Brilliant Green Agar-Difco). The efficiency of microbiological tests was measured by the following criteria: recovery, sensitivity and specificity. The results analysed by the Kendall concordance coefficients demonstrated that the rapid method appeared more effective even if poorly specific.

  3. A strategic approach for direct recovery and stabilization of Fusarium sp. ICT SAC1 cutinase from solid state fermented broth by carrier free cross-linked enzyme aggregates.

    Science.gov (United States)

    Chaudhari, Sandeep A; Singhal, Rekha S

    2017-05-01

    The major hurdles in commercial exploitation of cutinase (having both esterolytic and lipolytic activities) with potent industrial applications are its high production cost, operational instability and reusability. Although commercially available in immobilized form, its immobilization process (synthesis of support/carrier) makes it expensive. Herein we tried to address multiple issues of production cost, stability, and reusability, associated with cutinase. Waste watermelon rinds, an agroindustrial waste was considered as a cheap support for solid state fermentation (SSF) for cutinase production by newly isolated Fusarium sp. ICT SAC1. Subsequently, carrier free cross-linked enzyme aggregates of cutinase (cut-CLEA) directly from the SSF crude broth were developed. All the process variables affecting CLEA formation along with the different additives were evaluated. It was found that 50% (w/v) of ammonium sulphate, 125μmol of glutaraldehyde, cross-linking for 1h at 30°C and broth pH of 7.0, yielded 58.12% activity recovery. All other additives (hexane, butyric acid, sodium dodecyl sulphate, Trition-X 100, Tween-20, BSA) evaluated presented negative results to our hypothesis. Kinetics and morphology studies confirmed the diffusive nature of cut-CLEA and BSA cut-CLEA. Developed CLEA showed better thermal, solvent, detergent and storage stability, making it more elegant and efficient for industrial biocatalytic process. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Sensitivity of solid culture, broth culture, and real-time PCR assays for milk and colostrum samples from Mycobacterium avium ssp. paratuberculosis-infectious dairy cows.

    Science.gov (United States)

    Laurin, Emilie; McKenna, Shawn; Chaffer, Marcelo; Keefe, Greg

    2015-12-01

    Mycobacterium avium ssp. paratuberculosis (MAP) can be shed in feces, milk, and colostrum. The goal of this study was to assess assays that detect MAP in these sample types, including effects of lactation stage or season. Understanding the performance of these assays could improve how they are used, limiting the risk of infection to calves. Forty-six previously confirmed MAP-positive cows from 7 Atlantic Canadian dairy farms were identified for colostrum sampling and monthly sampling of milk and feces over a 12-mo period. Samples were assayed for MAP using solid culture, broth culture, and direct real-time PCR (qPCR). Across assay types, test sensitivity when applied to milk samples averaged 25% of that when applied to fecal samples. For colostrum samples, sensitivity depended on assay type, with sensitivity of qPCR being approximately 46% of that in feces. Across sample types, sensitivity of qPCR was higher than that of the other assays. Sensitivity of qPCR, when applied to milk samples, was significantly higher in summer than in other seasons. Summer was also the season with highest agreement between milk and fecal samples collected within the same month. Our results suggest that qPCR would detect more cows shedding MAP in their milk and colostrum than solid or broth culture assays, particularly during the summer, thus providing better management information to limit exposure of calves to this infectious organism. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. The influence of complex fermentation broth on denitrification of saline sewage in constructed wetlands by heterotrophic nitrifying/aerobic denitrifying bacterial communities.

    Science.gov (United States)

    Fu, Guiping; Yu, Tianyu; Huangshen, Linkun; Han, Jingyi

    2017-11-21

    An experimental vertical-flow constructed wetland (CW) was tested to treat salt-containing sewage. CW clogging deposits and withered Pontederia cordata L. were collected into a complex fermentation broth to serve as the carbon source and its effects on the denitrification capacity and microbial composition of the CW were examined. Addition of the complex fermentation broth into the CW influent (1.8% salinity) led to high removal efficiencies of NH 4 + -N > 99.82 ± 0.00% and TN > 90.39 ± 0.05%. Heterotrophic nitrifiers and aerobic denitrifiers were entirely dominant in the middle and upper layers of the CW, where obligate halophilic, aerobic denitrifiers Zobellella occurred. The CW successfully cultivated and enriched heterotrophic nitrifying-aerobic denitrifying bacteria, overcoming the effects of salinity and insufficient organic carbon sources on the denitrification capacity of CW. This type of complex carbon sources can also facilitate the utilization of waste resources, such as CW clogging deposits and withered wetland plants. Copyright © 2017. Published by Elsevier Ltd.

  6. Enhanced production of bioethanol from waste of beer fermentation broth at high temperature through consecutive batch strategy by simultaneous saccharification and fermentation.

    Science.gov (United States)

    Khattak, Waleed Ahmad; Khan, Taous; Ha, Jung Hwan; Ul-Islam, Mazhar; Kang, Min-Kyung; Park, Joong Kon

    2013-10-10

    Malt hydrolyzing enzymes and yeast glycolytic and fermentation enzymes in the waste from beer fermentation broth (WBFB) were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). A new 'one-pot consecutive batch strategy' was developed for efficient bio-ethanol production by simultaneous saccharification and fermentation (SSF) using WBFB without additional enzymes, microbial cells, or carbohydrates. Bio-ethanol production was conducted in batches using WBFB supernatant in the first phase at 25-67°C and 50rpm, followed by the addition of 3% WBFB solid residue to the existing culture broth in the second phase at 67°C. The ethanol production increased from 50 to 102.5g/L when bare supernatant was used in the first phase, and then to 219g ethanol/L in the second phase. The amount of ethanol obtained using this strategy was almost equal to that obtained using the original WBFB containing 25% solid residue at 33°C, and more than double that obtained when bare supernatant was used. Microscopic and gel electrophoresis studies revealed yeast cell wall degradation and secretion of cellular material into the surrounding medium. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) supported the existence of enzymes in WBFB involved in bioethanol production at elevated temperatures. The results of this study will provide insight for the development of new strategies for biofuel production. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. LB broth-lyophilized Rabbit serum (LLR) as a new and suitable culture medium for cultivation of promastigotes of Leishmania major.

    Science.gov (United States)

    Nasiri, Vahid; Dalimi, Abdolhossein; Ghaffarifar, Fatemeh

    2017-03-01

    Fetal calf serum is the major part and the most expensive ingredient of the Leishmania culture media. Here, the efficacy of the LB broth-lyophilized Rabbit serum medium (LLR) was evaluated in cultivation of Leishmaniamajor. Conventional Luria-Bertani (LB) broth medium was prepared and autoclaved for 15 min at 121 °C and then lyophilized Rabbit serum was added at the 1, 2.5, 5 and 10 % final concentrations. The efficacy of medium was evaluated by assessing the growth ability and replication pattern of the promastigotes of L. major. According to our finding, the LLR medium with 5-10 % lyophilized Rabbit serum supported the growth of the parasites and can be used for cultivation of Leishmanian parasites with acceptable In vivo infectivity for research purpose. The ability of the parasites to survive and proliferating in the presence of lyophilized Rabbit serum indicating that this serum is a good nutritional source. This study opens a new way to make low-cost medium that could be used in cultivation of Leishmanian parasites.

  8. Method

    Directory of Open Access Journals (Sweden)

    Ling Fiona W.M.

    2017-01-01

    Full Text Available Rapid prototyping of microchannel gain lots of attention from researchers along with the rapid development of microfluidic technology. The conventional methods carried few disadvantages such as high cost, time consuming, required high operating pressure and temperature and involve expertise in operating the equipment. In this work, new method adapting xurography method is introduced to replace the conventional method of fabrication of microchannels. The novelty in this study is replacing the adhesion film with clear plastic film which was used to cut the design of the microchannel as the material is more suitable for fabricating more complex microchannel design. The microchannel was then mold using polymethyldisiloxane (PDMS and bonded with a clean glass to produce a close microchannel. The microchannel produced had a clean edge indicating good master mold was produced using the cutting plotter and the bonding between the PDMS and glass was good where no leakage was observed. The materials used in this method is cheap and the total time consumed is less than 5 hours where this method is suitable for rapid prototyping of microchannel.

  9. Validation study to demonstrate the equivalence of a minor modification (TECRA ULTIMA protocol) to AOAC Method 998.09 (TECRA Salmonella Visual Immunoassay) with the cultural reference method.

    Science.gov (United States)

    Briggs, Julie; Dailianis, Angela; Hughes, Denise; Garthwaite, Ian

    2004-01-01

    The TECRA Salmonella Visual Immunoassay (VIA) using Rappaport-Vassiliadis RV[R10] as a single selective enrichment broth has Final Action approval (AOAC Method 998.09). TECRA has recently developed a protocol (TECRA ULTIMA), which involves the addition of a new additive to a 1 mL aliquot of the RV[R10] broth, prior to the heat-killing step, thereby allowing the RV[R10] broth to be tested directly in the kit and thus eliminating the need for the 2 h post-enrichment in M broth. An in-house validation study was conducted to compare the modified AOAC Method 998.09 to the reference culture method. Three foods were used in the study: Naturally contaminated raw ground poultry at high (10-50 cells/25 g), and low (1-5 cells/25 g) levels; and milk powder and peanut butter, artificially inoculated at low and high levels with Salmonella bovismorbificans and S. enterica Mbandaka, respectively. Twenty test portions were analyzed for each level with 10 uninoculated control samples per food. Overall, no significant differences (p analysis of RV[R10] broth has demonstrated the utility of the TECRA ULTIMA SALMONELLA protocol. It is recommended that the minor modification to Method 998.09 be approved First Action as an additional option within the method.

  10. method

    Directory of Open Access Journals (Sweden)

    L. M. Kimball

    2002-01-01

    Full Text Available This paper presents an interior point algorithm to solve the multiperiod hydrothermal economic dispatch (HTED. The multiperiod HTED is a large scale nonlinear programming problem. Various optimization methods have been applied to the multiperiod HTED, but most neglect important network characteristics or require decomposition into thermal and hydro subproblems. The algorithm described here exploits the special bordered block diagonal structure and sparsity of the Newton system for the first order necessary conditions to result in a fast efficient algorithm that can account for all network aspects. Applying this new algorithm challenges a conventional method for the use of available hydro resources known as the peak shaving heuristic.

  11. A Mixture of Bacillus thuringiensis subsp. israelensis With Xenorhabdus nematophila-Cultured Broth Enhances Toxicity Against Mosquitoes Aedes albopictus and Culex pipiens pallens (Diptera: Culicidae).

    Science.gov (United States)

    Park, Youngjin; Kyo Jung, Jin; Kim, Yonggyun

    2016-03-27

    XenorhabdusandPhotorhabdusspp. (Enterobacteriaceae) can synthesize and release secondary metabolites that play crucial roles in their pathogenicity by suppressing the immunity of target insects. The insect immunity contributes to defense against the pathogenicity ofBacillus thuringiensis(Bt). This study tested a hypothesis that bacterial immunosuppresants could enhance the susceptibility of mosquitoes (Aedes albopictusandCulex pipiens pallens) to Bt. Three symbiotic bacteria [X. nematophila(Xn),X. hominickii(Xh), andP. temperata temperata(Ptt)] were cultured in nutrient broth to allow them to produce secondary metabolites.Bacillus thuringiensis israelensis(BtI) was highly toxic to both culicid mosquitoes with median lethal concentration (LC50, spores/ml) of 2.9 × 105 and 2.2 × 105at 16 h after treatment, respectively. Addition of each bacteria-cultured broth enhanced BtI toxicity to these mosquito larvae. The LC50values of BtI toAe. albopictuslarvae were reduced to 1.5 × 105in Xn mixture, 1.7 × 105in Xh mixture, and 1.9 × 105 in Ptt mixture. The LC50values of BtI toCx. pipiens pallenslarvae were also reduced to 1.2 × 105in Xn mixture, 1.3 × 105in Xh mixture, and 1.5 × 105 in Ptt mixture. Adding benzylideneacetone or oxindole produced from Xn and Ptt also enhanced BtI toxicities to these mosquito larvae. Based on these results, we developed a new mosquitocidal Bt formulation called "Dip-Kill" consisting of 80% Xn-cultured broth, 10% BtI (1010spores/ml), and 10% preservative. Dip-Kill at 1,000 ppm was superior to a commercial BtI product at its recommended dose. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. THE EFFECT OF PROCESS CONDITIONS IN PREPARATION OF VEGETABLE BROTH AS SAVORY FLAVOR FROM MUNG BEANS (Phaseolus radiatus L. USING INOCULUM OF Rhizopus-C1

    Directory of Open Access Journals (Sweden)

    Agustine Susilowati

    2010-06-01

    Full Text Available Preparation of vegetable broth from mung beans (Phaseolus radiatus L. in semi pilot scale is an attempt development to get product of savory flavor in larger scale. The aim of this activity was to find out the effect of process multiplication on composition of vegetable broth from mung beans using inoculum of Rhizopus-C1 through brine fermentation in mixtures of inoculum, salt, and mung beans of 26, 23, and 51 %. This activity was conducted in both temperature of fermentation (room temperature and 30 °C, various time of fermentation (0, 2, 4, 6, 8, 10, and 12 weeks and process scales, namely laboratory scale (300 g and semi pilot scale (± 25 kg, respectively. The result of experiment indicated that fermentation temperature and time and process scales were tend to affect on composition of product. The length of fermentation time would increase concentrations of dissolved protein, N-amino and reducing sugar, decreased concentrations of fat and Volatile Reduction Substance (VRS, while concentrations of total protein, and water were tend to be constant in laboratory and semi pilot scales at the both process temperatures. Multiplication in preparation process of inoculum (7 kg using starter of Rhizopus-C1 resulted inoculum with activities of proteolytic of 0.71 U/g, and amilolytic of 17.5 U/g at 56 h of incubation. The whole process in semi pilot scale decreased composition of products. The optimal treatment based on recovery of total protein, and the highest amino acids as N-amino in semi pilot scale was at fermentation temperature of 30 ºC for 10 weeks with concentrations of water of 44.96%, total protein of 11.77% (dry matter, dissolved protein of 8 mg/mL, N-amino of 15.4 mg/mL, reducing sugar of 582.5 mg/mL, fat of 0.26% and, VRS of 90 µeq.reduction/g.   Keywords: Brine fermentation, vegetable broth, mung beans (Phaseolus radiatus L., Rhizopus-C1, semi pilot

  13. Influence of carvacrol and 1,8-cineole on cell viability, membrane integrity, and morphology of Aeromonas hydrophila cultivated in a vegetable-based broth.

    Science.gov (United States)

    de Sousa, Jossana Pereira; de Oliveira, Kataryne Árabe Rimá; de Figueiredo, Regina Celia Bressan Queiroz; de Souza, Evandro Leite

    2015-02-01

    This study investigated the effects of carvacrol (CAR) and 1,8-cineole (CIN) alone (at the MIC) or in combination at subinhibitory amounts (both at 1/8 MIC) on the cell viability, membrane permeability, and morphology of Aeromonas hydrophila INCQS 7966 (A. hydrophila) cultivated in a vegetable-based broth. CAR and CIN alone or in combination severely affected the viability of the bacteria and caused dramatic changes in the cell membrane permeability, leading to cell death, as observed by confocal laser microscopy. Scanning and transmission electron microscopy images of bacterial cells exposed to CAR or CIN or the mixture of both compounds revealed severe changes in cell wall structure, rupture of the plasma membrane, shrinking of cells, condensation of cytoplasmic content, leakage of intracellular material, and cell collapse. These findings suggest that CAR and CIN alone or in combination at subinhibitory amounts could be applied to inhibit the growth of A. hydrophila in foods, particularly as sanitizing agents in vegetables.

  14. Hypolipidemic Effects of Biopolymers Extracted from Culture Broth, Mycelia, and Fruiting Bodies of Auricularia auricula-judae in Dietary-induced Hyperlipidemic Rats

    Science.gov (United States)

    Jeong, Hun; Yang, Byung-Keun; Jeong, Yong-Tae; Kim, Guk-Nam; Jeong, Yu-Sun; Kim, Sang-Min; Mehta, Pradeep

    2007-01-01

    Hypolipidemic effect of biopolymers extracted from culture broth (CP), mycelia (MP), and fruiting bodies (FP) of Auricularia auricula-judae was investigated in dietary-induced hyperlipidemic rats. The experimental animals were administrated (100 mg/kg body weight) with different biopolymers, daily for 4 weeks. Hypolipidemic effects were achieved in all the experimental groups, however, FP was proved to be the most potent one. The administration of the FP reduced the plasma triglyceride, total cholesterol, low-density lipoprotein cholesterol, and atherogenic index by 24.3, 28.5, 36.4, and 40.9%, respectively, while increased the high-density lipoprotein cholesterol level (9.0%), when compared to the saline (control) administered group. PMID:24015062

  15. Method

    Directory of Open Access Journals (Sweden)

    Andrey Gnatov

    2015-01-01

    Full Text Available Recently repair and recovery vehicle body operations become more and more popular. A special place here is taken by equipment that provides performance of given repair operations. The most interesting things are methods for recovery of car body panels that allow the straightening without disassembling of car body panels and damaging of existing protective coating. Now, there are several technologies for repair and recovery of car body panels without their disassembly and dismantling. The most perspective is magnetic-pulse technology of external noncontact straightening. Basics of magnetic-pulse attraction, both ferromagnetic and nonferromagnetic thin-walled sheet metal, are explored. Inductor system calculation models of magnetic-pulse straightening tools are presented. Final analytical expressions for excited efforts calculation in the tools under consideration are introduced. According to the obtained analytical expressions, numerical evaluations of excited forces were executed. The volumetric epures of the attractive force radial distributions for different types of inductors were built. The practical testing of magnetic-pulse straightening with research tools is given. Using the results of the calculations we can create effective tools for an external magnetic-pulse straightening of car body panels.

  16. Determination of D-saccharic acid-1,4-lactone from brewed kombucha broth by high-performance capillary electrophoresis.

    Science.gov (United States)

    Wang, Kan; Gan, Xuhua; Tang, Xinyun; Wang, Shuo; Tan, Huarong

    2010-02-01

    Kombucha is a health tonic. D-saccharic acid-1,4-lactone (DSL), a component of kombucha, inhibits the activity of glucuronidase, an enzyme indirectly related with cancers. To date, there is no efficient method to determine the content of DSL in kombucha samples. In this paper, we report a rapid and simple method for the separation and determination of DSL in kombucha samples, using the high-performance capillary electrophoresis (HPCE) method with diode array detection (DAD). With optimized conditions, DSL can be separated in a 50 cm length capillary at a separation voltage of 20 kV in 40 mmol/L borax buffer (pH 6.5) containing 30 mmol/L SDS and 15% methanol (v/v). Quantitative evaluation of DSL was determined by ultraviolet absorption at lambda=190 nm. The relationship between the peak areas and the DSL concentrations, in a specified working range with linear response, was determined by first-order polynomial regression over the range 50-1500 microg/mL with a detection limit of 17.5 microg/mL. Our method demonstrated excellent reproducibility and accuracy with relative standard deviations (RSD) of less than 5% DSL content (n=5). This is the first report to determine DSL by HPCE. We have successfully applied this method to determine DSL in kombucha samples in various fermented conditions. 2009 Elsevier B.V. All rights reserved.

  17. Análise sensorial de caldos e canjas elaborados com farinha de carcaças de peixe defumadas: aplicação na merenda escolar Sensorial analysis of soups and broths made by smoked fish carcasses meal: its utilization to supplement school meals

    Directory of Open Access Journals (Sweden)

    Leandro Cesar de Godoy

    2010-05-01

    Full Text Available O trabalho avaliou a aceitação de caldos e canjas elaborados com farinhas aromatizadas desenvolvidas a partir de carcaças de peixes defumadas. As carcaças de tilápia do Nilo, carpa e pacu foram lavadas, identificadas, pesadas, imersas em salmoura com ervas aromáticas e defumadas. O produto defumado foi submetido à moagem para obtenção das farinhas, a partir das quais foram elaborados o caldo e a canja. Porções das farinhas, dos caldos e das canjas foram avaliadas por um painel de 40 provadores utilizando-se um método de estímulo simples, sendo avaliados os atributos: aroma, sabor, cor, textura, aparência e aceitação geral. Não houve diferença significativa (P > 0,05 na aceitação geral dos produtos. Os caldos elaborados com estas farinhas tiveram uma excelente aceitação, não diferindo significativamente entre si no que se refere aos atributos avaliados. A canja elaborada a partir da farinha de carcaça de pacu apresentou as menores notas quando comparada às demais canjas. Portanto, as farinhas aromatizadas podem ser empregadas no enriquecimento de produtos para o consumo humano. Esses produtos podem ser aplicados na merenda escolar, melhorando a qualidade nutricional das refeições. Além disso, tal uso daria um destino nobre aos resíduos que podem causar sérios impactos se descartados no meio ambiente.This work evaluated the acceptance of soups and broths prepared with aromatized meals made from smoked fish carcasses. The species of fish used for smoking were Nile Tilapia , carp, and pacu. The carcasses were washed, labeled, weighted, immersed in a solution of brine with aromatic herbs, and smoked. The smoked product was crushed to obtain the meal, which was used to cook the soups and the broths . Portions of meals, broths and soups were sampled by 40 tasters based on a simple stimulus method, which evaluated characteristics such as aroma, flavor, color, texture, aspect, and general acceptance. Considering the three

  18. Comparison of the performances and validation of three methods for ...

    African Journals Online (AJOL)

    Conclusion: It appears from this study that the prior-enrichment at 25 ° C in a Brain Heart Infusion broth containing 2.5 mg / l novobiocin followed by a modified PBS (Phosphate-buffered saline) enrichment are appropriate methods for monitoring the epidemiology of enteropathogenics Yersinia in the animal faecal samples.

  19. Microbial process for the preparation of acetic acid, as well as solvent for its extraction from the fermentation broth

    Science.gov (United States)

    Gaddy, James L.; Clausen, Edgar C.; Ko, Ching-Whan; Wade, Leslie E.; Wikstrom, Carl V.

    2004-06-22

    A modified water-immiscible solvent useful in the extraction of acetic acid from aqueous streams is a substantially pure mixture of isomers of highly branched di-alkyl amines. Solvent mixtures formed of such a modified solvent with a desired co-solvent, preferably a low boiling hydrocarbon, are useful in the extraction of acetic acid from aqueous gaseous streams. An anaerobic microbial fermentation process for the production of acetic acid employs such solvents, under conditions which limit amide formation by the solvent and thus increase the efficiency of acetic acid recovery. Methods for the direct extraction of acetic acid and the extractive fermentation of acetic acid also employ the modified solvents and increase efficiency of acetic acid production. Such increases in efficiency are also obtained where the energy source for the microbial fermentation contains carbon dioxide and the method includes a carbon dioxide stripping step prior to extraction of acetic acid in solvent.

  20. Self-assembling systems based on quaternized derivatives of 1,4-diazabicyclo[2.2.2]octane in nutrient broth as antimicrobial agents and carriers for hydrophobic drugs.

    Science.gov (United States)

    Pashirova, Tatiana N; Lukashenko, Svetlana S; Zakharov, Sergey V; Voloshina, Alexandra D; Zhiltsova, Elena P; Zobov, Vladimir V; Souto, Eliana B; Zakharova, Lucia Ya

    2015-03-01

    Aggregation properties of mono (mono-CS) and dicationic (di-CS) surfactants, namely quaternised derivatives of 1,4-diazabicyclo[2.2.2]octane (DABCO), have been evaluated in water and in nutrient broths of different pH, i.e. in Hottinger broth (рН=7.2) and Sabouraud dextrose broth (рН=5.6). Aggregation capacity of surfactants was shown to be responsible for the solubilization properties of a complex composed of a hydrophobic probe (Sudan I) and a selected drug (quercetin), contributing to the antimicrobial activity of this surfactant system. The effect of N-methyl-d-glucamine (NmDg) additive on the antimicrobial activity of mono-CS, and its aggregation and solubilization parameters, has also been evaluated. A substantial decrease in critical micelle concentration (CMC) of cationic surfactants in nutrient broths (up to 60 times) has been reported. Twofold dilution of monocationic surfactant by NmDg slightly changed the CMC of surfactant; however, it provided a remarkable increase in solubilization capacity (∼by 4 times) and decrease in its toxicity. The data anticipate the potential use of DABCO quaternized derivatives as innovative non-toxic delivery systems for hydrophobic drugs. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Influence of aerobic and anaerobic conditions on survival of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in Luria-Bertani broth, farm-yard manure and slurry

    NARCIS (Netherlands)

    Semenov, A.V.; Overbeek, van L.S.; Termorshuizen, A.J.; Bruggen, van A.H.C.

    2011-01-01

    The influence of aerobic and anaerobic conditions on the survival of the enteropathogens Escherichia coli O157:H7 and Salmonella serovar Typhimurium was investigated in microcosms with broth, cattle manure or slurry. These substrates were inoculated with a green fluorescent protein transformed

  2. Influence of aerobic and anaerobic conditions on survival of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in Luria-Bertani broth, farm-yard manure and slurry

    NARCIS (Netherlands)

    Semenov, Alexander V.; van Overbeek, Leo; Termorshuizen, Aad J.; van Bruggen, Ariena H. C.

    The influence of aerobic and anaerobic conditions on the survival of the enteropathogens Escherichia coli O157:H7 and Salmonella serovar Typhimurium was investigated in microcosms with broth, cattle manure or slurry. These substrates were inoculated with a green fluorescent protein transformed

  3. Effect of Listeria seeligeri or Listeria welshimeri on Listeria monocytogenes detection in and recovery from buffered Listeria enrichment broth.

    Science.gov (United States)

    Dailey, Rachel C; Welch, Lacinda J; Hitchins, Anthony D; Smiley, R Derike

    2015-04-01

    The presence of multiple species of Listeria in regulated food products is not uncommon and can complicate the recovery of Listeria monocytogenes particularly on a non-differentiating medium. The potential complications of Listeria seeligeri and Listeria welshimeri on the recovery of L. monocytogenes from inoculated food test samples using the U.S. Food and Drug Administration's (FDA) selective enrichment procedure was investigated. Post-enrichment enumeration, in the absence of food product, indicates that some L. seeligeri and L. monocytogenes pairings may have population differentials as great as 2.7 ± 0.1 logs with L. seeligeri being the predominant species. A similar observation was noted for L. welshimeri and L. monocytogenes pairings which resulted in population differentials as large as 3.7 ± 0.2 logs with L. welshimeri being the predominant species. Select strain pairings were used to inoculate guacamole, crab meat, broccoli, and cheese with subsequent recovery by the FDA Bacteriological Analytical Manual (BAM) method with 10 colonies per sample selected for confirmation. The presence of L. seeligeri had little effect on the recovery of L. monocytogenes. The presence of L. welshimeri resulted in the failure to recover L. monocytogenes in three out of the four food matrices. This work extends the observation that non-pathogenic species of Listeria can complicate the recovery of L. monocytogenes and that competition during selective enrichment is not limited to the presence of just Listeria innocua. Published by Elsevier Ltd.

  4. In Vitro and In Vivo Anti-Helicobacter Activities of Eryngium foetidum (Apiaceae), Bidens pilosa (Asteraceae), and Galinsoga ciliata (Asteraceae) against Helicobacter pylori

    OpenAIRE

    Kouitcheu Mabeku, Laure brigitte; Eyoum Bille, Bertrand; Nguepi, Eveline

    2016-01-01

    This study was performed to evaluate the antimicrobial activities of extracts of Bidens pilosa, Galinsoga ciliata, and Eryngium foetidum against 6 clinical strains of Helicobacter pylori in vitro and in vivo. Broth microdilution method was used in vitro. In vivo, Swiss mice were inoculated with H. pylori and divided into 5 groups; the control group received the vehicle and the four others received 125, 250, and 500?mg/kg of methanol extract of Eryngium foetidum and ciprofloxacin (500?mg/kg) f...

  5. The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives

    OpenAIRE

    Souza, Marina Azevêdo; Johann, Susana; Lima, Luciana Alves Rodrigues dos Santos; Campos, Fernanda Fraga; Mendes, Isolda Castro; Beraldo, Heloisa; de Souza-Fagundes, Elaine Maria; Cisalpino, Patrícia Silva; Rosa, Carlos Augusto; Alves, Tânia Maria de Almeida; de Sá, Nívea Pereira; Zani, Carlos Leomar

    2013-01-01

    Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazo...

  6. Screening for antibacterial and antibiofilm activity in Thai medicinal plant extracts against oral microorganisms

    OpenAIRE

    Teanpaisan, Rawee; Kawsud, Pajaree; Pahumunto, Nuntiya; Puripattanavong, Jindaporn

    2016-01-01

    To evaluate the antibacterial activity of 12 ethanol extracts of Thai traditional herb against oral pathogens. The antibacterial activities were assessed by agar well diffusion, broth microdilution, and time-kill methods. Antibiofilm activity was investigated using a 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium-bromide (MTT) assay. High performance liquid chromatography (HPLC), thin layer chromatography (TLC) fingerprinting, and TLC-bioautography were used to determine the active ...

  7. Antimicrobial susceptibility of porcine brachyspira hyodysenteriae isolates from Switzerland

    OpenAIRE

    Kirchgässner, Constanze

    2016-01-01

    The anaerobic spirochaete Brachyspira (B.) hyodysenteriae is the causative agent of swine dysentery (SD), a severe mucohaemorrhagic diarrheal disease in pigs worldwide. Currently, no data for antimicrobial susceptibility of B. hyodysenteriae from Switzerland are available and though antimicrobial treatment is the main therapy, no standardised methods for antimicrobial susceptibility testing are established. Therefore, a broth microdilution test was performed for 30 Swiss porcine field isolate...

  8. Punicalagin Inhibits Salmonella Virulence Factors and Has Anti-Quorum-Sensing Potential

    OpenAIRE

    Li, Guanghui; Yan, Chunhong; Xu, Yunfeng; Feng, Yuqing; Wu, Qian; Lv, Xiaoying; Yang, Baowei; Wang, Xin; Xia, Xiaodong

    2014-01-01

    Punicalagin, an essential component of pomegranate rind, has been demonstrated to possess antimicrobial activity against several food-borne pathogens, but its activity on the virulence of pathogens and its anti-quorum-sensing (anti-QS) potential have been rarely reported. This study investigated the efficacy of subinhibitory concentrations of punicalagin on Salmonella virulence factors and QS systems. A broth microdilution method was used to determine the MICs of punicalagin for 10 Salmonella...

  9. Assessment of Ibicella lutea for antibacterial agent front Staphylococcus aureus

    OpenAIRE

    Lisiane Martins Volcão; Tatiane Silveira Coelho; Alváro Vàsquez; Maria Pia Cerdeiras; Pedro Eduardo Almeida da Silva; Flávio Manoel Rodrigues da Silva Júnior; Daniela Fernandes Ramos

    2016-01-01

    Justificative and Objectives: the study aimed the assessment of the antibacterial activity of crude extracts and fractions of Ibicella lutea, front Staphylococcus aureus, thecombination of these compounds and cytotoxic activity. Methods: was used for antibacterial activity the Microdilution Test Broth, and performed the Checkerboard Test. The extracts showed antibacterial activity were submitted to the citotoxicity test, with macrophages cell and determination of the Selectivity Index (SI). R...

  10. Chemical Composition and Antimicrobial Activity of Leaf, Ripe and Unripe Peel of Bitter Orange (Citrus aurantium) Essential Oils

    OpenAIRE

    Fatemeh Azhdarzadeh; Mohammad Hojjati

    2016-01-01

    Background and Objectives: The chemical composition and antimicrobial activity of bitter orange (Citrus aurantium) leaf, ripe and unripe peel essential oils, cultivated in southwest of Iran, were investigated. Materials and Methods: The analysis of chemical composition of hydro-distilled essential oils was carried out by GC-MS. The disc diffusion and broth micro-dilution were used to assay the antimicrobial effect of achieved essential oils. Results: According to the GC-MS analysis, 3...

  11. Species Identification, Strain Differentiation, and Antifungal Susceptibility of Dermatophyte Species Isolated From Clinically Infected Arabian Horses

    DEFF Research Database (Denmark)

    El Damaty, Hend M; Tartor, Yasmine H; Mahmmod, Yasser Saadeldien Ibrahim

    2017-01-01

    Arabian horses, the eldest equine breeds, have great economic and social significance for its long, unique, and storied history. Molecular characterization of dermatophyte species affecting Arabian horses is a crucial necessity for epidemiologic and therapeutic purposes. The objective of this study...... was to identify and differentiate isolates of dermatophytes isolated from naturally infected Arabian horses at species and strains levels using PCR-restriction fragment length polymorphism (RFLP) and DNA sequencing. Additionally, antifungal susceptibility testing using broth microdilution method was performed...

  12. In vitro sensitivity of poultry Brachyspira isolates to essential oil components and in vivo reduction of Brachyspira intermedia in rearing pullets with cinnamaldehyde feed supplementation

    OpenAIRE

    Verlinden, Marc; Pasmans, Frank; Mahu, Maxime; Vande Maele, Lien; De Pauw, Nele; YANG Zhen; Haesebrouck, Freddy; Martel, An

    2013-01-01

    Cecal enteritis due to Brachyspira infections tends to be chronic in laying hens. Limited availability of antimicrobial drugs for use in laying hens emphasizes the need for alternative control measures. A broth microdilution method was used to determine the antimicrobial susceptibility of 20 Brachyspira intermedia field isolates from laying hen flocks to components of essential oils (EO). Minimal inhibitory concentration (MIC) distributions, obtained for eight EO components, were all monomoda...

  13. In vitro antibacterial activity of doripenem against clinical isolates from French teaching hospitals: proposition of zone diameter breakpoints

    OpenAIRE

    Lascols, C.; Legrand, P.; Mérens, A.; Leclercq, R.; Armand-Lefevre, L.; Drugeon, H. B.; Kitzis, M. D.; Muller-Serieys, C.; Reverdy, M. E.; Roussel-Delvallez, M.; Moubareck, C.; Lemire, A.; Miara, A.; Gjoklaj, M.; Soussy, C.-J.

    2010-01-01

    Abstract The aims of the study were to determine the in vitro activity of doripenem, a new carbapenem, against a large number of bacterial pathogens and to propose zone diameter breakpoints for clinical categorization in France according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) minimum inhibitory concentration (MIC) breakpoints. The MICs of doripenem were determined by the broth microdilution method against 1,547 clinical isolates from eight French...

  14. C-3 Substituted Lawsonemonoximates of Holmium(III): Synthesis, Characterization, and Antimicrobial Activity

    OpenAIRE

    S. B. Jagtap; S G Joshi; Litake, G. M.; Ghole, V. S.; Kulkarni, B. A.

    2000-01-01

    A series of five new metal complexes of Ho(III) with C-3 substituted derivatives of lawsonemonexime (2-hydroxy-1,4-naphthalenediene-1-oxime) were synthesized. The compounds were characterized by melting point, elemental analysis, IR spectroscopy and magnetic susceptibility. The antimicrobial activity of the compounds were determined by disk diffusion method and broth micro-dilution techniques using Mueller Hinton medium against the following organisms: S. aureus ATCC 6538P, Klebsiella pneumon...

  15. Antimicrobial Peptides Containing Unnatural Amino Acid Exhibit Potent Bactericidal Activity against ESKAPE Pathogens

    Science.gov (United States)

    2013-01-01

    Laboratory Standards broth microdilution method. MIC is defined as the lowest concentration of the test antimicrobial that would inhibit the growth of the...idues exhibit negative hydrophobicity and by shortening the side chain the protonated nitrogen is moved closer to the peptide back- bone . This...it appears that back- bone flexibility after the hydrophobic or charged residue and the following Tic residue is more important in the interactions

  16. Optimization of a Real Time PCR based method for the detection of Listeria monocytogenes in pork meat.

    Science.gov (United States)

    Gattuso, Antonietta; Gianfranceschi, Monica Virginia; Sonnessa, Michele; Delibato, Elisabetta; Marchesan, Massimo; Hernandez, Marta; De Medici, Dario; Rodriguez-Lazaro, David

    2014-08-01

    The aim of this study was to optimize a Real-Time PCR protocol for a rapid detection of Listeria monocytogenes in pork meat, using reduced volumes of primary selective enrichment broth and times of incubation to decrease the cost and time for analysis. Forty-five samples of pork meat were artificially contaminated with two different levels of L. monocytogenes (1-10 CFU per sample and 10-100 CFU per sample), homogenized in three different volumes of Half Fraser Broth (1:3; 1:5 and 1:10) and incubated at 30°C ± 1°C for 5h, 8h and 24h. The detection was conducted in parallel by Real-Time PCR and the ISO standard 11290-1 methods. L. monocytogenes was detected in all the samples after 24h by Real-Time PCR method, also using reduced volumes of Half Fraser Broth. This represents a clear advantage as the time to final detection and the inherent costs were significantly reduced compared to the ISO reference method. All samples artificially contaminated were correctly detected also after 8 of incubation at 30°C ± 1°C in Half Fraser Broth and 24h in Fraser Broth at 37°C ± 1°C using cultural method. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Impact of Cell-free Supernatant of Lactic Acid Bacteria on Putrescine and Other Polyamine Formation by Foodborne Pathogens in Ornithine Decarboxylase Broth.

    Science.gov (United States)

    Ozogul, Fatih; Tabanelli, Giulia; Toy, Nurten; Gardini, Fausto

    2015-06-24

    Conversion of ornithine to putrescine by Salmonella Paratyphi A, Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli was investigated in ornithine decarboxylase broth (ODB) using cell-free supernatants (CFSs) obtained from Leuconostoc mesenterodies subsp. cremoris, Pediococcus acidilactici, Lactococcus lactis subsp. lactis, Streptococcus thermophilus. Two groups of cell-free supernatants (25 or 50%) and control (only ODB) were prepared to investigate putrescine (PUT) and other polyamine formation by foodborne pathogens (FBPs). Significant differences (p < 0.05) were observed among the species for each amine. All of the CFSs reduced the formation of PUT by ≥65%. The production of cadaverine (CAD) was scarcely affected by the presence of CFSs, with the exception of the samples inoculated with L. monocytogenes. The variation in polyamine was found with respect to the control samples. Spermidine (SPD) was produced in lower amount in many samples, especially in Gram-negative FBPs, whereas spermine (SPN) increased drastically in the major part of the samples concerning the control. Histamine (HIS) was characterized by a marked concentration decrease in all of the samples, and tyramine (TYR) was accumulated in very low concentrations in the controls. Therefore, the ability of bacteria to produce certain biogenic amines such as HIS, TYR, PUT, and CAD has been studied to assess their risk and prevent their formation in food products. The results obtained from this study concluded that the lactic acid bacteria (LAB) strains with non-decarboxylase activity are capable of avoiding or limiting biogenic amine formation by FBP.

  18. Wenzhouxiangella marina gen. nov, sp. nov, a marine bacterium from the culture broth of Picochlorum sp. 122, and proposal of Wenzhouxiangellaceae fam. nov. in the order Chromatiales.

    Science.gov (United States)

    Wang, Guanghua; Tang, Mingxing; Li, Tao; Dai, Shikun; Wu, Huanlian; Chen, Chenghao; He, Hui; Fan, Jiewei; Xiang, Wenzhou; Li, Xiang

    2015-06-01

    A Gram-stain negative, non-motile, non-phototrophic, non-alkaliphilic, obligately aerobic, chemoheterotrophic, and rod-shaped bacterium, designated strain Ma-11(T), was isolated from the culture broth of a marine microalga, Picochloruma sp. 122. Phylogenetic analyses showed that strain Ma-11(T) has less than 91 % similarity to its closest relative, Thioalkalivibrio sulfidiphilus HL-EbGR7(T), represents a distinct phylogenetic lineage in the order Chromatiales, and could not be assigned to any defined families in this order. Chemotaxonomic, genetic and physiological characteristics, including major fatty acids, genomic G+C content, lack of motility, aerophilicity and chemoheterotrophicity, could readily distinguish strain Ma-11(T) from any established members of the order Chromatiales. Based on the 16S rRNA gene sequence analysis and its signature nucleotide pattern, a new family Wenzhouxiangellaceae fam. nov. comprising the genus Wenzhouxiangella gen. nov. and species Wenzhouxiangella marina sp. nov. is proposed. The type strain is Ma-11(T) (=CGMCC 1.14936(T) = KCTC 42284(T) = MCCC 1K00261(T)).

  19. Potential of the waste from beer fermentation broth for bio-ethanol production without any additional enzyme, microbial cells and carbohydrates.

    Science.gov (United States)

    Ha, Jung Hwan; Shah, Nasrullah; Ul-Islam, Mazhar; Park, Joong Kon

    2011-08-10

    The potential of the waste from beer fermentation broth (WBFB) for the production of bio-ethanol using a simultaneous saccharification and fermentation process without any extra additions of saccharification enzymes, microbial cells or carbohydrate was tested. The major microbial cells in WBFB were isolated and identified. The variations in compositions of WBFB with stock time were investigated. There was residual activity of starch hydrolyzing enzymes in WBFB. The effects of reaction modes e.g. static and shaking on bio-ethanol production were studied. After 7 days of cultivation using the supernatant of WBFB at 30 °C the ethanol concentration reached 103.8 g/L in shaking culture and 91.5 g/L in static culture. Agitation experiments conducted at a temperature-profile process in which temperature was increased from 25 to 67 °C shortened the simultaneous process time. The original WBFB was more useful than the supernatant of WBFB in getting the higher concentration of ethanol and reducing the fermentation time. From this whole study it was found that WBFB is a cheap and suitable source for bio-ethanol production. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Sublethal amounts of Origanum vulgare L. essential oil and carvacrol cause injury and changes in membrane fatty acid of Salmonella Typhimurium cultivated in a meat broth.

    Science.gov (United States)

    Luz, Isabelle da Silva; de Melo, Adma Nadja Ferreira; Bezerra, Taliana Kênia Alves; Madruga, Marta Suely; Magnani, Marciane; de Souza, Evandro Leite

    2014-05-01

    This study aimed to evaluate whether sublethal concentrations of the essential oil of Origanum vulgare L. (OVEO) and its major compound carvacrol (CAR) cause injury to the cell membrane and outer membrane of Salmonella enterica serovar Typhimurium ATCC 14028 grown in a meat broth and to assess the effect of these substances on membrane fatty acid (FA) composition. Exposure of Salmonella Typhimurium ATCC 14028 to sublethal concentrations of OVEO or CAR caused damage to the cytoplasmic membrane and outer membrane. OVEO- and CAR-treated cells showed lower amounts of saturated FA than nontreated cells. Changes in membrane FA composition were mainly related to an increase of C16:1ω7c, C16:1ω7t, and C18:2ω6c, and to a decrease of C16:0, C17:0 cyclo, and C19:0 cyclo. These results indicate that exposure to sublethal concentrations of OVEO or CAR caused sublethal injury Salmonella Typhimurium ATCC 14028 and suggest that an adaptive response to these stresses is related to increased synthesis of unsaturated FA and cis-trans isomerization.

  1. Chemical Analysis of a "Miller-Type" Complex Prebiotic Broth. Part II: Gas, Oil, Water and the Oil/Water-Interface

    Science.gov (United States)

    Scherer, Sabrina; Wollrab, Eva; Codutti, Luca; Carlomagno, Teresa; da Costa, Stefan Gomes; Volkmer, Andreas; Bronja, Amela; Schmitz, Oliver J.; Ott, Albrecht

    2017-12-01

    We have analyzed the chemical variety obtained by Miller-Urey-type experiments using nuclear magnetic resonance (NMR) spectroscopy and coherent anti-Stokes Raman scattering (CARS) spectroscopy, gas chromatography followed by mass spectrometry (GC/MS) and two-dimensional gas chromatography followed by mass spectrometry (GCxGC/MS). In the course of a running Miller-Urey-type experiment, a hydrophobic organic layer emerged besides the hydrophilic aqueous phase and the gaseous phase that were initially present. The gas phase mainly consisted of aromatic compounds and molecules containing C≡ C or C≡ N triple bonds. The hydrophilic phase contained at least a few thousands of different molecules, primarily distributed in a range of 50 and 500 Da. The hydrophobic phase is characterized by carbon-rich, oil-like compounds and their amphiphilic derivatives containing oxygen with tensioactive properties. The presence of a wide range of oxidized molecules hints to the availability of oxygen radicals. We suggest that they intervene in the formation of alkylated polyethylene glycol (PEG) in the oil/water interface. CARS spectroscopy revealed distinct vibrational molecular signatures. In particular, characteristic spectral bands for cyanide compounds were observed if the broth was prepared with electric discharges in the gaseous phase. The characteristic spectral bands were absent if discharges were released onto the water surface. NMR spectroscopy on the same set of samples independently confirmed the observation. In addition, NMR spectroscopy revealed overall high chemical variability that suggests strong non-linearities due to interdependent, sequential reaction steps.

  2. Induction of apoptosis in HepG2 cells by polysaccharide MEP-II from the fermentation broth of Morchella esculenta.

    Science.gov (United States)

    Hu, Meili; Chen, Yan; Wang, Cui; Cui, Huali; Duan, Peilu; Zhai, Tianlong; Yang, Yuling; Li, Shaofei

    2013-01-01

    A novel polysaccharide, MEP-II, isolated from the fermentation broth of Morchella esculenta inhibited the proliferation of human hepatoma cell line (HepG2) through an apoptotic pathway. After HepG2 cells were treated with 150-600 μg MEP-II/ml, typical apoptotic characteristics including externalization of phosphatidylserine residues on the cell surface, nuclear fragmentation, chromatin condensation and cytoplasm shrinkage were observed. Furthermore, reactive oxygen species (ROS) burst and the collapse of mitochondrial membrane potential (Δψm) also occurred in HepG2 cells after incubation of 150-600 μg MEP-II/ml. The antioxidant, 1 mM N-acetyl-L-cysteine inhibited MEP-II-induced apoptosis, suggesting that ROS are the key mediators for MEP-II-induced apoptosis. MEP-II is therefore a potential anti-tumor agent that induces apoptosis of HepG2 cells through ROS generation.

  3. Chemical Analysis of a "Miller-Type" Complex Prebiotic Broth : Part II: Gas, Oil, Water and the Oil/Water-Interface.

    Science.gov (United States)

    Scherer, Sabrina; Wollrab, Eva; Codutti, Luca; Carlomagno, Teresa; da Costa, Stefan Gomes; Volkmer, Andreas; Bronja, Amela; Schmitz, Oliver J; Ott, Albrecht

    2017-12-01

    We have analyzed the chemical variety obtained by Miller-Urey-type experiments using nuclear magnetic resonance (NMR) spectroscopy and coherent anti-Stokes Raman scattering (CARS) spectroscopy, gas chromatography followed by mass spectrometry (GC/MS) and two-dimensional gas chromatography followed by mass spectrometry (GCxGC/MS). In the course of a running Miller-Urey-type experiment, a hydrophobic organic layer emerged besides the hydrophilic aqueous phase and the gaseous phase that were initially present. The gas phase mainly consisted of aromatic compounds and molecules containing C≡C or C≡N triple bonds. The hydrophilic phase contained at least a few thousands of different molecules, primarily distributed in a range of 50 and 500 Da. The hydrophobic phase is characterized by carbon-rich, oil-like compounds and their amphiphilic derivatives containing oxygen with tensioactive properties. The presence of a wide range of oxidized molecules hints to the availability of oxygen radicals. We suggest that they intervene in the formation of alkylated polyethylene glycol (PEG) in the oil/water interface. CARS spectroscopy revealed distinct vibrational molecular signatures. In particular, characteristic spectral bands for cyanide compounds were observed if the broth was prepared with electric discharges in the gaseous phase. The characteristic spectral bands were absent if discharges were released onto the water surface. NMR spectroscopy on the same set of samples independently confirmed the observation. In addition, NMR spectroscopy revealed overall high chemical variability that suggests strong non-linearities due to interdependent, sequential reaction steps.

  4. Improving downstream processes to recover tartaric acid, tartrate and nutrients from vinasses and formulation of inexpensive fermentative broths for xylitol production.

    Science.gov (United States)

    Salgado, José Manuel; Rodríguez, Noelia; Cortés, Sandra; Domínguez, José Manuel

    2010-10-01

    Vinasses, the main liquid wastes from the distillation process of grape marc and wine lees, are acidic effluents with high organic content, including acids, carbohydrates, phenols, and unsaturated compounds with high chemical oxygen demand, biological oxygen demand and solid concentrations. These wastes can be revalued to provide additional benefits when they are employed as feedstock of some compounds including tartaric acid, calcium tartrate and economic nutrients for the elaboration of fermentable broths. This study attempts to recover tartaric acid and calcium tartrate from vinasses. All the tartaric acid initially solubilised was recovered in both processes. The residual streams can be successfully employed as economic nutrients for the xylose to xylitol bioconversion, achieving higher global volumetric productivities (Q(P, xylitol) = 0.232 g L(-1) h(-1)) and products yields (Y(xylitol/S) = 0.57 g g(-1)) than fermentations carried out using commercial nutrients (Q(P, xylitol) = 0.193 g L(-1) h(-1) and Y(xylitol/S) = 0.55 g g(-1) respectively). Tartaric acid can be recovered from vinasses in the form of tartaric acid crystals and calcium tartrate. The residual streams generated in the process can be used as economic nutrients for the production of xylitol by D. hansenii. Copyright © 2010 Society of Chemical Industry.

  5. Antimicrobial activity of phenolic extracts from olive leaves and grape skins and seeds - Impact of encapsulation

    DEFF Research Database (Denmark)

    Tadić, Dorde; Čadež, Neža; Ota, Ajda

    2012-01-01

    Olive leaves and grape skin with seeds produced as by-products in olive oil and wine production constitute a cheap source of plant material with certain amount of bio-active substances. Antioxidant, antimicrobial, anti-inflammatory and anticancer properties of the phenolic extracts were reported...... by broth microdilution method for minimal inhibitory concentrations (MICs) of phenolic extracts from olive leaves (Olea europaea, cv. "Leccino") and grape skins and seeds (Vitis vinifera L, cv "Zelen") against 14 strains of Candida, Pichia and Ogataea sp., which were isolated from spoiled olive oil...... extracts from olive leaves and grape skins with seeds expressed high efficiency against most isolates of spoilage yeasts. Encapsulated olive leaves extracts showed the same or better efficiency than non-encapsulated extracts in broth microdilution screening test and during yeast growth inhibition in liquid...

  6. K. OXYTOCA BACTERIOPHAGES ISOLATION METHODS IMPROVEMENT

    OpenAIRE

    G. R. Sadrtdinova

    2017-01-01

    The article presents the results of a study related to increasing the efficiency of phage isolation of bacteria of the species K. oxytoca, by developing the optimal composition of the medium used in the work. In scientific research, in almost all methods associated with the isolation of bacteriophages, meat-peptone broth and meat-peptone agar are used as the nutrient basis. The peculiarities of growth and cultivation of microorganisms create certain difficulties for the isolation of phages ac...

  7. A simple and rapid cultural method for detection of Enterobacter sakazakii in environmental samples

    NARCIS (Netherlands)

    Guillaume-Gentil, O.; Sonnard, V.; Kandhai, M.C.; Marugg, J.; Joosten, H.

    2005-01-01

    A method was developed to detect and identify Enterobacter sakazakii in environmental samples. The method is based on selective enrichment at 45 ± 0.5°C in lauryl sulfate tryptose broth supplemented with 0.5 M NaCl and 10 mg/liter vancomycin (mLST) for 22 to 24 h followed by streaking on tryptone

  8. Development of interpretive criteria for tebipenem disk diffusion susceptibility testing with Staphylococcus spp. and Haemophilus influenzae.

    Science.gov (United States)

    Fujisaki, Momoko; Sadamoto, Shinya; Ikedo, Masanari; Totsuka, Kyoichi; Kaku, Mitsuo; Tateda, Kazuhiro; Hirakata, Yoichi; Yamaguchi, Keizo

    2011-02-01

    Disk diffusion susceptibility interpretive criteria for tebipenem against Staphylococcus spp. and Haemophilus influenzae were developed using the Clinical and Laboratory Standards Institute (CLSI) guidelines. Tebipenem was tested by disk diffusion and broth microdilution methods against 119 clinical isolates of Staphylococcus spp. and 102 clinical isolates of H. influenzae. The zone diameters of 5-, 10-, and 30-μg disks were compared with broth microdilution minimum inhibitory concentration (MIC) results by scattergram and regression analysis. When the MIC breakpoint of 1 μg/ml was applied to the scattergrams, the 10-μg disk showed good correlation between the zone diameters and the MIC values. The corresponding disk diffusion zone diameter breakpoints with the 10-μg disk for Staphylococcus spp. were ≧22 mm (MIC ≦1 μg/ml) for susceptible, 20-21 mm (MIC = 2 μg/ml) for intermediate, and ≦19 mm (MIC ≧4 μg/ml) for resistant. We also proposed the breakpoint zone diameter of H. influenzae: ≧22 mm (MIC ≦1 μg/ml) for susceptible. These criteria demonstrated that the categorical agreements between disk diffusion and broth microdilution methods for Staphylococcus spp. and H. influenzae were 95.0% and 99.0%, respectively. The discrepancy rates of these criteria were acceptable to the CLSI guidelines.

  9. Escherichia coli K-12 survives anaerobic exposure at pH 2 without RpoS, Gad, or hydrogenases, but shows sensitivity to autoclaved broth products.

    Directory of Open Access Journals (Sweden)

    Daniel P Riggins

    Full Text Available Escherichia coli and other enteric bacteria survive exposure to extreme acid (pH 2 or lower in gastric fluid. Aerated cultures survive via regulons expressing glutamate decarboxylase (Gad, activated by RpoS, cyclopropane fatty acid synthase (Cfa and others. But extreme-acid survival is rarely tested under low oxygen, a condition found in the stomach and the intestinal tract. We observed survival of E. coli K-12 W3110 at pH 1.2-pH 2.0, conducting all manipulations (overnight culture at pH 5.5, extreme-acid exposure, dilution and plating in a glove box excluding oxygen (10% H2, 5% CO2, balance N2. With dissolved O2 concentrations maintained below 6 µM, survival at pH 2 required Cfa but did not require GadC, RpoS, or hydrogenases. Extreme-acid survival in broth (containing tryptone and yeast extract was diminished in media that had been autoclaved compared to media that had been filtered. The effect of autoclaved media on extreme-acid survival was most pronounced when oxygen was excluded. Exposure to H2O2 during extreme-acid treatment increased the death rate slightly for W3110 and to a greater extent for the rpoS deletion strain. Survival at pH 2 was increased in strains lacking the anaerobic regulator fnr. During anaerobic growth at pH 5.5, strains deleted for fnr showed enhanced transcription of acid-survival genes gadB, cfa, and hdeA, as well as catalase (katE. We show that E. coli cultured under oxygen exclusion (<6 µM O2 requires mechanisms different from those of aerated cultures. Extreme acid survival is more sensitive to autoclave products under oxygen exclusion.

  10. Influence of NaCl reduction and replacement on the growth of Lactobacillus sakei in broth, cooked ham and white sauce.

    Science.gov (United States)

    Samapundo, S; Ampofo-Asiama, J; Anthierens, T; Xhaferi, R; Van Bree, I; Szczepaniak, S; Goemaere, O; Steen, L; Dhooge, M; Paelinck, H; Dewettinck, K; Devlieghere, F

    2010-09-30

    The growth inhibiting effects of NaCl and selected simple salt replacers (CaCl(2), MgCl(2), KCl and MgSO(4)) on the growth of Lactobacillus sakei were studied in de Man Rogosa Sharpe broth at 7 degrees C over a water phase concentration of 0 to 6.4%. The divalent chloride salts (CaCl(2) in particular) generally had the largest antimicrobial activities at equivalent water phase concentrations, molalities or water activity (a(w)) values. MgSO(4) had not only the least antimicrobial activity but also the smallest a(w) depressing capacity. The results also showed that the antimicrobial effects of CaCl(2) were not fully accounted for by its a(w) depressing effects. Challenge tests performed on cooked ham and white sauce showed that reduction of NaCl levels by 28 and 33%, respectively, had no influence on the microbial stability of these products to L. sakei. Ultimately the study concluded that the microbiological consequences of the full or partial replacement of NaCl on the growth of L. sakei largely depend on the initial level of NaCl, the level of replacement and the nature of the salt replacer used. Altered stability to L. sakei is most likely given a high initial NaCl level, combined with a large level of partial replacement with either CaCl(2) (increased stability) or MgSO(4) (reduced stability) as the replacer. Copyright 2010 Elsevier B.V. All rights reserved.

  11. The influence of the cell free solution of lactic acid bacteria on tyramine production by food borne-pathogens in tyrosine decarboxylase broth.

    Science.gov (United States)

    Toy, Nurten; Özogul, Fatih; Özogul, Yesim

    2015-04-15

    The function of cell-free solutions (CFSs) of lactic acid bacteria (LAB) on tyramine and other biogenic amine production by different food borne-pathogens (FBPs) was investigated in tyrosine decarboxylase broth (TDB) using HPLC. Cell free solutions were prepared from four LAB strains. Two different concentrations which were 50% (5 ml CFS+5 ml medium/1:1) and 25% (2.5 ml CFS+7.5 ml medium/1:3) CFS and the control without CFS were prepared. Both concentration of CFS of Streptococcus thermophilus and 50% CFS of Pediococcus acidophilus inhibited tyramine production up to 98% by Salmonella paratyphi A. Tyramine production by Escherichia coli was also inhibited by 50% CFS of Lactococcus lactis subsp. lactis and 25% CFS of Leuconostoc lactis. subsp. cremoris. The inhibitor effect of 50% CFS of P. acidophilus was the highest on tyramine production (55%) by Listeria monocytogenes, following Lc. lactis subsp. lactis and Leuconostoc mesenteroides subsp. cremoris (20%) whilst 25% CFS of Leu. mes. subsp. cremoris and Lc. lactis subsp. lactis showed stimulator effects (160%). The stimulation effects of 50% CFS of S. thermophilus and Lc. lactis subsp. lactis were more than 70% by Staphylococcus aureus comparing to the control. CFS of LAB strains showed statistically inhibitor effect since lactic acid inhibited microbial growth, decreased pH quickly and reduced the formation of AMN and BAs. Consequently, in order to avoid the formation of high concentrations of biogenic amines in fermented food by bacteria, it is advisable to use CFS for food and food products. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Use of conventional and real-time polymerase chain reaction for confirmation of Mycobacterium avium subsp. paratuberculosis in a broth-based culture system ESP II.

    Science.gov (United States)

    Kim, Sung G; Kim, Eun H; Lafferty, Caroline J; Miller, Loretta J; Koo, Hye J; Stehman, Susan M; Shin, Sang J

    2004-09-01

    The ESP II Culture System (ESP II), a broth-based culture system, has been modified and optimized for culturing Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) in animal feces since 2000. Conventional and real-time polymerase chain reaction (PCR) assays based on the IS900 sequence were performed as confirmatory tests for M. paratuberculosis in ESP II liquid culture medium. There were no differences between test results of conventional and real-time PCR assays. During the 5-week incubation period, if acid-fast bacilli (AFB) were detected in ESP culture-positive samples, IS900 PCR assays were performed to confirm whether those AFB were M. paratuberculosis. At the end of the 5-week incubation, AF staining was performed on all ESP II-negative cultures to screen any false-negative cultures; IS900 PCR assays were performed on AFB-positive cultures. During a period of 1 year, of a total of 18,499 ESP II cultures, 2,814 (15.2%) PCR confirmation assays were performed. Of those, 2,259 (80%) were both ESP and PCR positive; 104 (4%) were ESP positive and PCR negative; 423 (15%) were ESP negative and PCR positive; 28 (1%) were both ESP and PCR negative. The AF-staining step after the 5-week incubation produced 423 (15%) more PCR-positive cultures. Of a total of 2,814 AFB-positive cultures, 132 (5%) were not confirmed as M. paratuberculosis. Further studies are needed for speciation of non-M. paratuberculosis isolates.

  13. Characterization of Enterotoxigenic Bacillus cereus sensu lato and Staphylococcus aureus Isolates and Associated Enterotoxin Production Dynamics in Milk or Meat-Based Broth

    Science.gov (United States)

    Walker-York-Moore, Laura; Moore, Sean C.; Fox, Edward M.

    2017-01-01

    Bacillus cereus sensu lato species, as well as Staphylococcus aureus, are important pathogenic bacteria which can cause foodborne illness through the production of enterotoxins. This study characterised enterotoxin genes of these species and examined growth and enterotoxin production dynamics of isolates when grown in milk or meat-based broth. All B. cereus s. l. isolates harboured nheA, hblA and entFM toxin genes, with lower prevalence of bceT and hlyII. When grown at 16 °C, toxin production by individual B. cereus s. l. isolates varied depending on the food matrix; toxin was detected at cell densities below 5 log10(CFU/mL). At 16 °C no staphylococcal enterotoxin C (SEC) production was detected by S. aureus isolates, although low levels of SED production was noted. At 30 °C all S. aureus isolates produced detectable enterotoxin in the simulated meat matrix, whereas SEC production was significantly reduced in milk. Relative to B. cereus s. l. toxin production, S. aureus typically required reaching higher cell numbers to produce detectable levels of enterotoxin. Phylogenetic analysis of the sec and sel genes suggested population evolution which correlated with animal host adaptation, with subgroups of bovine isolates or caprine/ovine isolates noted, which were distinct from human isolates. Taken together, this study highlights the marked differences in the production of enterotoxins both associated with different growth matrices themselves, but also in the behaviour of individual strains when exposed to different food matrices. PMID:28714887

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

    LENUS (Irish Health Repository)

    Creagh, S

    2012-02-03

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

  15. Lactobionic acid enhances the synergistic effect of nisin and thymol against Listeria monocytogenes Scott A in tryptic soy broth and milk.

    Science.gov (United States)

    Chen, Huaiqiong; Zhong, Qixin

    2017-11-02

    Listeria monocytogenes is a Gram-positive opportunistic human pathogen and it remains a significant cause of foodborne illnesses. A variety of natural and synthetic compounds have been studied to inhibit the growth of L. monocytogenes in foods. Antimicrobial combinations with synergistic antilisterial properties can reduce the dose of each antimicrobial, which can be further enhanced by chelating compounds. Therefore, the objective of this study was to determine antilisterial properties of binary or ternary combinations of lactobionic acid (LBA), nisin, and thymol in tryptic soy broth (TSB), 2% reduced-fat milk, and whole milk. The results showed that the minimum inhibitory concentration (MIC) of nisin, thymol and LBA was 125IU/mL, 0.25mg/mL, and 10mg/mL, respectively. The ternary combination was the most effective in reducing MICs of antimicrobials, with the MIC of nisin, thymol, and LBA being 31.25IU/mL, 0.0625mg/mL, and 1.25mg/mL, respectively. In TSB with 0.6% yeast extract, L. monocytogenes grew in individual or binary antimicrobial treatments of 31.25IU/mL nisin, 0.0625mg/mL thymol, and 1.25mg/mL LBA within 24h at 32°C, while it was completely inhibited by the ternary combination. In 2% reduced-fat milk at 21°C, the ternary combination of nisin, thymol, and LBA at respective concentrations of 250IU/mL, 2mg/mL, and 10mg/mL completely inhibited the bacterium to below the detection limit in 72h while >2log (CFU/mL) bacteria was still detected in all the binary combinations after 120h. In whole milk, the combination of 500IU/mL nisin, 2mg/mL thymol, and 10mg/mL LBA reduced bacteria to around 2log (CFU/mL) in 4h at 21°C, and no bacterial recovery was observed after 5 d. This study suggested the potential of the ternary combination of nisin, thymol and LBA for food preservation. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. An easy method for detection of nasopharyngeal carriage of multiple Streptococcus pneumoniae serotypes

    DEFF Research Database (Denmark)

    Kaltoft, Margit S.; Sørensen, Uffe; Slotved, Hans-Christian

    2008-01-01

    In this paper, a simplified method for detection of pneumococcal carriage and for revealing the presence of several serotypes in a nasopharyngeal sample is evaluated. Enrichment broth was used for transportation and for the initial culturing of samples. All specimens were examined directly by the...

  17. Culture conditions and sample preparation methods affect spectrum quality and reproducibility during profiling of Staphylococcus aureus with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Goldstein, J E; Zhang, L; Borror, C M; Rago, J V; Sandrin, T R

    2013-08-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as a promising tool to rapidly characterize Staphylococcus aureus. Different protocols have been employed, but effects of experimental factors, such as culture condition and sample preparation, on spectrum quality and reproducibility have not been rigorously examined. We applied MALDI-TOF MS to characterize a model system consisting of five methicillin-sensitive (MSSA) and five methicillin-resistant S. aureus isolates (MRSA) under two culture conditions (agar and broth) and using two sample preparation methods [intact cell method and protein extraction method (PEM)]. The effects of these treatments on spectrum quality and reproducibility were quantified. PEM facilitated increases in the number of peaks and mass range width. Broth cultures further improved spectrum quality in terms of increasing the number of peaks. In addition, PEM increased reproducibility in samples prepared using identical culture conditions. MALDI imaging data suggested that the improvement in reproducibility may result from a more homogeneous distribution of sample associated with the broth/PEM treatment. Broth/PEM treatment also yielded the highest rate (96%) of correct classification for MRSA. Taken together, these results suggest that broth/PEM maximizes the performance of MALDI-TOF MS to characterize S. aureus. Two culture conditions (agar or broth) and two sample preparation methods (intact cell or protein extraction) were evaluated for their effects on profiling of Staphylococcus aureus using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Results indicated that MALDI-enabled profiling of S. aureus is most effective when cultures are grown in broth and processed using a protein extraction-based approach. These findings should enhance future efforts to maximize the performance of this approach to characterize strains of S. aureus. © 2013

  18. Standardization of hyphal growth inhibition rate as a means of evaluating Microsporum spp. in vitro susceptibility to terbinafine, griseofulvin, and ciclopiroxolamine.

    Science.gov (United States)

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

    2011-10-01

    Reference methods for antifungal susceptibility tests recommend the use of conidia as inoculum. However, some isolates produce few conidia, while the invasive form of filamentous fungi in general is hyphae making susceptibility tests infeaseble. These facts suggest that other than conidia broth dilution method is required for susceptibility tests. The aim of this study was to clarify if the hyphal growth inhibition rate could be used as a method of determining the antifungal susceptibility of genus Microsporum. For this reason, a method which traces hyphal tips automatically and measures their growth rate was standardized for Microsporum spp. Control growth curves and test growth curves obtained by real-time observation of the hyphae groups responses to different concentrations of terbinafine, griseofulvin, and ciclopiroxolamine were used to compare with minimum inhibitory concentrations (MICs) obtained by conidia broth microdilution method. A visible reduction in the growth inhibition rate was observed when hyphal activity was evaluated using the third or fourth serial two-fold dilution below the MIC determined by broth microdilution for terbinafine and ciclopiroxolamine. For griseofulvin, this reduction occurred after the fifth dilution below the MIC. This study highlights the importance of the inoculum type used to determine the in vitro susceptibility of Microsporum strains. We conclude that measurement of hyphal growth inhibition, despite being time consuming, could be a suitable method for evaluating antifungal susceptibility, particularly for fungi as Microsporum spp. that produce a small (or not at all) number of conidia.

  19. Comparative Analysis of Three Methods for Determination of Imipenem Resistance in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Tanaz Zabihi

    2016-02-01

    Full Text Available "> Background: These days, the antibiotic resistance of Pseudomonas aeruginosa isolates toimipenem has significantly increased. Therefore the study of resistance to imipenem in thisorganism to imipenem in determining the appropriate treatment is crucial and necessary. The goalof this study is to compare three phenotypic methods of E-test, disk diffusion and micro brothdilution in the study of resistance to imipenem in clinical isolates of P. aeruginosa.Methods: Within a 6-month interval, 120 clinical specimens were collected and evaluated. Allisolates were identified as P. aeruginosa by standard biochemical tests and amplification of 16SrRNA gene. Three phenotypic methods of E-test, disk diffusion, and micro broth dilution wereused to determine imipenem resistance in P. aeruginosa isolates.Results: Of the 96 P. aeruginosa isolates studied for their resistance to imipenem by the use ofE-test, disk diffusion and micro broth dilution methods, 38.5% of the strains in micro broth dilutionmethod and 33.3% in the two methods of E-test and disk diffusion were resistant to imipenem. Therate of sensitivity and specificity of disk diffusion and E-test methods were 100%, 90.1%, and theywere 100% and 83.1% for micro broth dilution, respectively.Conclusions: With regard to the results obtained from the comparison of the three methods100% agreement were observed among the antimicrobial susceptibility results obtained by the Etest and disk diffusion methods (P ≥ 0.05. Therefore, the use of disk diffusion method can bean appropriate replacement for E-test method with regard to its being easy and cost-effective.

  20. TLC-bioautography directed isolation of antibacterial compounds from active fractionation of Ferula ferulioides.

    Science.gov (United States)

    Sun, Zhong-Lin; Liu, Tao; Wang, Shuang-Ying; Ji, Xiao-Yue; Mu, Qing

    2018-01-30

    A novel optimised isolation method, TLC-bioautography, was evaluated and utilised in this research. Antibacterial compounds which were isolated from the dichloromethane extract of Ferula ferulioides (Steud.) Korovin were detected by means of the method. Their structures were elucidated by extensive spectral and chemical methods. Their antibacterial activities against drug-resistant Staphylococcus aureus (S. aureus) strains were evaluated with broth microdilution method, and the results proved that TLC-bioautography was an effective and highly efficient way to screen natural compounds from plant extracts against drug-resistant strains.

  1. Antimicrobial Effect of aqueous extract of saffron petals on some of food-borne bacterial pathogen

    Directory of Open Access Journals (Sweden)

    L Azami

    2012-05-01

    Full Text Available Ever-increasing public debates over the adverse effects that may result from exposure to the chemical preservatives have enhanced the interests for the consuming of preservative-free foods or at least the product containing natural preservatives. In this laboratory experiment, the antimicrobial effect of aqueous extracts of Saffron petals against Salmonella typhimurium, Listeria monocytogenes, Escherichia coli O157:H7, Bacillus cereus and Staphylococcus aureus were investigated using the disk diffusion method. Moreover, the Minimum Inhibitory Concentration (MIC of the extract was assessed by agar dilution and broth microdilution method. According to the results, S. typhimurium was found asthe most sensitive, while, S. aureus and E. coli O157:H7asthe most resistant species. MICs of the extract by microdilution method were estimated at 40 mg/ml for all of the 4 bacterial species. The results also revealed that the extract of Saffron petals could be used as a natural preservative against the aforementioned bacteria.

  2. Comparison of different sampling techniques and of different culture methods for detection of group B streptococcus carriage in pregnant women

    Directory of Open Access Journals (Sweden)

    Verhelst Rita

    2010-09-01

    Full Text Available Abstract Background Streptococcus agalactiae (group B streptococcus; GBS is a significant cause of perinatal and neonatal infections worldwide. To detect GBS colonization in pregnant women, the CDC recommends isolation of the bacterium from vaginal and anorectal swab samples by growth in a selective enrichment medium, such as Lim broth (Todd-Hewitt broth supplemented with selective antibiotics, followed by subculture on sheep blood agar. However, this procedure may require 48 h to complete. We compared different sampling and culture techniques for the detection of GBS. Methods A total of 300 swabs was taken from 100 pregnant women at 35-37 weeks of gestation. For each subject, one rectovaginal, one vaginal and one rectal ESwab were collected. Plating onto Columbia CNA agar (CNA, group B streptococcus differential agar (GBSDA (Granada Medium and chromID Strepto B agar (CA, with and without Lim broth enrichment, were compared. The isolates were confirmed as S. agalactiae using the CAMP test on blood agar and by molecular identification with tDNA-PCR or by 16S rRNA gene sequence determination. Results The overall GBS colonization rate was 22%. GBS positivity for rectovaginal sampling (100% was significantly higher than detection on the basis of vaginal sampling (50%, but not significantly higher than for rectal sampling (82%. Direct plating of the rectovaginal swab on CNA, GBSDA and CA resulted in detection of 59, 91 and 95% of the carriers, respectively, whereas subculturing of Lim broth yielded 77, 95 and 100% positivity, respectively. Lim broth enrichment enabled the detection of only one additional GBS positive subject. There was no significant difference between GBSDA and CA, whereas both were more sensitive than CNA. Direct culture onto GBSDA or CA (91 and 95% detected more carriers than Lim broth enrichment and subculture onto CNA (77%. One false negative isolate was observed on GBSDA, and three false positives on CA. Conclusions In

  3. Antioxidant and antimicrobial activities of aporphinoids and other alkaloids from the bark of Annona salzmannii A. DC. (Annonaceae).

    Science.gov (United States)

    Costa, Emmanoel Vilaça; da Cruz, Pedro Ernesto Oliveira; de Lourenço, Caroline Caramano; de Souza Moraes, Valéria Regina; de Lima Nogueira, Paulo Cesar; Salvador, Marcos José

    2013-01-01

    The antioxidant capacity by oxygen radical absorbance capacity (ORAC)-FL method and antimicrobial activity using the broth microdilution method of aporphinoids (liriodenine 1, anonaine 2 and asimilobine 3) and other alkaloids (reticuline 4 and cleistopholine 5) isolated from the bark of Annona salzmannii A. DC. (Annonaceae) were evaluated. For antioxidant activity, the most active alkaloid was asimilobine with ORAC value of 2.09 relative trolox equivalents. For antimicrobial activity, some alkaloids showed significant minimal inhibitory concentration (MIC) values in the range of 25-100 µg mL(-1). The most active compounds were the aporphinoids liriodenine, anonaine and asimilobine, some of them more active than the positive control.

  4. Diferentes condimentos vegetais: avaliação sensorial e de atividade antibacteriana em preparação alimentar com frango cozido Different spice plants: sensorial evaluation and antibacterial activity in chicken broth

    Directory of Open Access Journals (Sweden)

    F. Rodrigues

    2011-01-01

    , individualmente, atividade antibacteriana significativa, mesmo que sem significância quando comparados entre si. Contudo, em relação ao tempo de início da atividade antibacteriana, destacou-se a pimenta dedo-de-moça, enquanto que, em relação ao prolongamento dessa ação no tempo, destacou-se o alho nirá. As 12 plantas condimentares em estudo tiveram atestada a sensorialidade, sendo que as quatro plantas com destaque tiveram a atividade anti-coliforme termo-resistente comprovada in loco. Diferentes condimentos vegetais foram capazes de fornecer qualificação sensorial e sanitária em caldo com frango cozido, em condições domésticas de manuseio.Based on the in vitro antibacterial activity predetermined for 12 spice plants with ethnographic indicator, this feature was tested in loco in the model cooked chicken broth. First, ten evaluators were trained, according to the current legislation for Free and Informed Consent, providing previous knowledge about the plants parsley (Petroselinum sativum, marjoram (Origanum X aplii and Origanum majorana, basil (Ocimum basilicum, common sage (Salvia officinalis, thyme (Thymus vulgaris, anis-like spice (Ocimum selloi, african basilicum (Ocimum gratissimum, nirá garlic (Allium tuberosum, leek (Allium porrum, turmeric (Curcuma longa and "dedo-de-moça" chili (Capsicum baccatum. Those spices were individually added to the chicken broth to perform a Hedonic Scale-like Acceptance Test, selecting four of the twelve spices that had higher sensory acceptance, "dedo-de-moça" chili, nirá garlic, leek and thyme. A new Acceptance Test was then performed using low, medium and high concentrations of those four spices to establish the most acceptable sensory intensities. The elected quantities (0.5 g "dedo-de-moça" chili, 15 g nirá garlic, 15 g leek and 5 g thyme were added to the chicken broth, then challenged with Escherichia coli (ATCC 11229 at a final 10 concentration of CFU/mL, the tolerated limit according to legislation. The control

  5. Comparative study for 147 Candida spp. identification and echinocandins susceptibility in isolates obtained from blood cultures in 15 hospitals, Medellin, Colombia.

    Science.gov (United States)

    Berrio, Indira; Maldonado, Natalia; De Bedout, Catalina; Arango, Karen; Cano, Luz Elena; Valencia, Yorlady; Jiménez-Ortigosa, Cristina; Perlin, David S; Gómez, Beatriz L; Robledo, Carlos; Robledo, Jaime

    2017-11-26

    Invasive candidiasis has high impact on morbidity and mortality in hospitalized patients. Accurate and timely methods for identification of Candida species and determination of equinocandins susceptibility become a priority for laboratories of clinical microbiology. A study was performed to compare MALDI-TOF MS identification to sequencing of D1/D2 region of rRNA gene complex 28 subunit, in 147 isolates obtained from patients with candidemia. Susceptibility testing was performed by broth microdilution method and Etest ® . DNA sequencing of FKS1 and FKS2 genes was performed. In this study, the most common species were C. albicans (40.8%), followed by C. parapsilosis (23.1%) and C. tropicalis (17.0%). Overall agreement between the results of identification by MALDI-TOF MS and molecular identification was 99.3%. Anidulafungin and caspofungin susceptibility by broth microdilution method were 98% and 88.4%, respectively. Susceptibility to anidulafungin and caspofungin by Etest was 93.9% and 98.6%. Categorical agreement between Etest and broth microdilution method was 91.8% for anidulafungin and 89.8% for caspofungin; with lower agreements in C. parapsilosis for anidulafungin (76.5%) and C. glabrata for caspofungin (40.0%). No mutations related to resistance were found in FKS genes, although 54 isolates presented synonymous polymorphisms in the hot spots sequenced. MALDI TOF MS is a good alternative for routine identification of Candida isolates. DNA sequencing of FKS genes suggests that isolates analyzed are susceptible to echinocandins; alternatively, unknown resistance mechanisms or limitations related to antifungal susceptibility tests may explain the resistance found in few isolates. Copyright © 2017. Published by Elsevier Ltd.

  6. Direct identification from positive blood broth culture by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS).

    Science.gov (United States)

    Barberino, Maria Goreth; Silva, Marcio de Oliveira; Arraes, Ana Carolina Palmeiras; Correia, Luís Cláudio; Mendes, Ana Verena

    Bloodstream infections (BSIs) are among the most concerning bacterial infections. They are one of the leading causes of morbidity and mortality, and occur in 30-70% of critical care patients. The prompt identification of the causative microorganism can help choosing the appropriate antimicrobial therapy that will lead to better clinical outcomes. Blood culture is one of the most relevant tests for microbiological diagnosis of bacterial infections. The introduction of the MALDI-TOF microbiological diagnosis significantly decreased the time of identifying microorganisms. However, it depends on the growth on solid culture medium. In this study, 538 bottles of positive blood cultures were evaluated to test the accuracy of an in house modified protocol. The study sample consisted of 198 Gram-negative and 350 Gram-positive bacteria. In all, 460 (83.94%) species were identified based on the direct plate findings. The protocol allowed the identification of 185/198 (93.43%) of the Gram-negative bacteria, including aerobes, anaerobes, and non-fermenters, and 275/350 (78.85%) of the Gram-positive bacteria. The proposed method has the potential to provide accurate results in comparison to the traditional method with the potential to reduce the turnaround time for the results and optimize antimicrobial therapy in BSI. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

  7. Direct identification from positive blood broth culture by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS

    Directory of Open Access Journals (Sweden)

    Maria Goreth Barberino

    2017-05-01

    Full Text Available Bloodstream infections (BSIs are among the most concerning bacterial infections. They are one of the leading causes of morbidity and mortality, and occur in 30–70% of critical care patients. The prompt identification of the causative microorganism can help choosing the appropriate antimicrobial therapy that will lead to better clinical outcomes. Blood culture is one of the most relevant tests for microbiological diagnosis of bacterial infections. The introduction of the MALDI-TOF microbiological diagnosis significantly decreased the time of identifying microorganisms. However, it depends on the growth on solid culture medium. In this study, 538 bottles of positive blood cultures were evaluated to test the accuracy of an in house modified protocol. The study sample consisted of 198 Gram-negative and 350 Gram-positive bacteria. In all, 460 (83.94% species were identified based on the direct plate findings. The protocol allowed the identification of 185/198 (93.43% of the Gram-negative bacteria, including aerobes, anaerobes, and non-fermenters, and 275/350 (78.85% of the Gram-positive bacteria. The proposed method has the potential to provide accurate results in comparison to the traditional method with the potential to reduce the turnaround time for the results and optimize antimicrobial therapy in BSI.

  8. [Antimicrobial susceptibilities of clinical Nocardia isolates identified by 16S rRNA gene sequence analysis].

    Science.gov (United States)

    Uner, Mahmut Celalettin; Hasçelik, Gülşen; Müştak, Hamit Kaan

    2016-01-01

    Nocardia species are ubiquitous in the environment and responsible for various human infections such as pulmonary, cutaneous, central nervous system and disseminated nocardiosis. Since the clinical pictures and antimicrobial susceptibilities of Nocardia species exhibit variability, susceptibility testing is recommended for every Nocardia isolates. The aims of this study was to determine the antimicrobial susceptibilities of Nocardia clinical isolates and to compare the results of broth microdilution and disc diffusion susceptibility tests. A total of 45 clinical Nocardia isolates (isolated from 17 respiratory tract, 8 brain abscess, 7 pus, 3 skin, 3 conjunctiva, 2 blood, 2 tissue, 2 pleural fluid and 1 cerebrospinal fluid samples) were identified by using conventional methods and 16S rRNA gene sequence analysis. Susceptibility testing was performed for amikacin, ciprofloxacin, ceftriaxone, linezolid and trimethoprim-sulfamethoxazole (TMP-SMX) by broth microdilution method according to the Clinical and Laboratory Standards Institute (CLSI) criteria recommended in 2011 approved standard (M24-A2) and disk diffusion method used as an alternative comparative susceptibility testing method. Among the 45 Nocardia strains, N.cyriacigeorgica (n: 26, 57.8%) was the most common species, followed by N.farcinica (n: 12, 26.7%), N.otitiscaviarum (n: 4, 8.9%), N.asteroides (n: 1, 2.2%), N.neocaledoniensis (n: 1, 2.2%) and N.abscessus (n: 1, 2.2%). Amikacin and linezolid were the only two antimicrobials to which all isolates were susceptible for both broth microdilution and disk diffusion tests. In broth microdilution test, resistance rates to TMP-SMX, ceftriaxone and ciprofloxacin were found as 15.6%, 37.8% and 84.4% respectively, whereas in the disk diffusion test, the highest resistance rate was observed against ciprofloxacin (n: 33, 73.3%), followed by TMP-SMX (n: 22, 48.9%) and ceftriaxone (n: 15, 33.3%). In both of these tests, N.cyriacigeorgica was the species with the

  9. Postenrichment Population Differentials Using Buffered Listeria Enrichment Broth: Implications of the Presence of Listeria innocua on Listeria monocytogenes in Food Test Samples†

    Science.gov (United States)

    KEYS, ASHLEY L.; DAILEY, RACHEL C.; HITCHINS, ANTHONY D.; SMILEY, R. DERIKE

    2016-01-01

    The recovery of low levels of Listeria monocytogenes from foods is complicated by the presence of competing microorganisms. Nonpathogenic species of Listeria pose a particular problem because variation in growth rate during the enrichment step can produce more colonies of these nontarget cells on selective and/or differential media, resulting in a preferential recovery of nonpathogens, especially Listeria innocua. To gauge the extent of this statistical barrier to pathogen recovery, 10 isolates each of L. monocytogenes and L. innocua were propagated together from approximately equal initial levels using the current U.S. Food and Drug Administration’s enrichment procedure. In the 100 isolate pairs, an average 1.3-log decrease was found in the 48-h enrichment L. monocytogenes population when L. innocua was present. In 98 of the 100 isolate pairs, L. innocua reached higher levels at 48 h than did L. monocytogenes, with a difference of 0.2 to 2.4 log CFU/ml. The significance of these population differences was apparent by an increase in the difficulty of isolating L. monocytogenes by the streak plating method. L. monocytogenes went completely undetected in 18 of 30 enrichment cultures even after colony isolation was attempted on Oxoid chromogenic Listeria agar. This finding suggests that although both Listeria species were present on the plate, the population differential between them restricted L. monocytogenes to areas of the plate with confluent growth and that isolated individual colonies were only L. innocua. PMID:24215687

  10. Postenrichment population differentials using buffered Listeria enrichment broth: implications of the presence of Listeria innocua on Listeria monocytogenes in food test samples.

    Science.gov (United States)

    Keys, Ashley L; Dailey, Rachel C; Hitchins, Anthony D; Smiley, R Derike

    2013-11-01

    The recovery of low levels of Listeria monocytogenes from foods is complicated by the presence of competing microorganisms. Nonpathogenic species of Listeria pose a particular problem because variation in growth rate during the enrichment step can produce more colonies of these nontarget cells on selective and/or differential media, resulting in a preferential recovery of nonpathogens, especially Listeria innocua. To gauge the extent of this statistical barrier to pathogen recovery, 10 isolates each of L. monocytogenes and L. innocua were propagated together from approximately equal initial levels using the current U. S. Food and Drug Administration's enrichment procedure. In the 100 isolate pairs, an average 1.3-log decrease was found in the 48-h enrichment L. monocytogenes population when L. innocua was present. In 98 of the 100 isolate pairs, L. innocua reached higher levels at 48 h than did L. monocytogenes, with a difference of 0.2 to 2.4 log CFU/ml. The significance of these population differences was apparent by an increase in the difficulty of isolating L. monocytogenes by the streak plating method. L. monocytogenes went completely undetected in 18 of 30 enrichment cultures even after colony isolation was attempted on Oxoid chromogenic Listeria agar. This finding suggests that although both Listeria species were present on the plate, the population differential between them restricted L. monocytogenes to areas of the plate with confluent growth and that isolated individual colonies were only L. innocua.

  11. Listeria spp. in broiler flocks: recovery rates and species distribution investigated by conventional culture and the EiaFoss method

    DEFF Research Database (Denmark)

    Petersen, Line Hedegård; Madsen, Mogens

    2000-01-01

    The occurrence of Listeria monocytogenes in samples from broiler houses and cloacal swabs taken at the abattoir was investigated. An automated immunobased method (EiaFoss) was used, and 42 samples were also analysed by conventional culture; both methods were based on a two-step selective enrichment...... using CHR.4.17; Fraser and Fraser broths. L. monocytogenes was isolated from two of 71 broiler hocks, yielding an estimated flock prevalence of 3%. The flock prevalence of L. inocua was estimated to 13%, and it was speculated that the potential of this apathogenic bacteria to grow faster than L....... monocytogenes in enrichment broths may lead to an underestimation of the prevalence of L. monocytogenes. Furthermore, as L. inocua was also detected by the EiaFoss method, a significant amount of bacterial confirmation work had to be done. Of 42 samples analysed by conventional culture, four yielded L. inocua...

  12. Development and Application of a New Microarray- Based Method for High-Throughput Screening of Carbohydrate Active Enzymes

    DEFF Research Database (Denmark)

    Vidal Melgosa, Silvia

    . The applicability of the method to identify the substrate specificities of purified uncharacterised enzymes as well as for screening CAZyme activities in complex enzyme mixtures, such as crude culture broths and plant extracts, is shown by examples presented in this thesis. We envisage that the method......The effective and sustainable use of plant biomass for second generation biofuels is of vital importance for reducing dependence on fossil fuels. Carbohydrate-active enzymes (CAZymes) that degrade lignocellulosic plant cell wall material are an important part of this effort. CAZymes have multiple......-quantitative screening technique is sensitive, reproducible and robust. The possibilities of the method, regarding both substrates and enzymes, have been extensively explored, demonstrating its broad versatility. The catalytic activities of single enzymes, enzyme mixtures and crude culture broths can be assessed against...

  13. Lanthanum triflate triggered synthesis of tetrahydroquinazolinone derivatives of N-allyl quinolone and their biological assessment

    Directory of Open Access Journals (Sweden)

    Jardosh Hardik H.

    2012-01-01

    Full Text Available A series of 24 derivatives of tetrahydroquinazolinone has been synthesized by one-pot cyclocondensation reaction of N-allyl quinolones, cyclic β-diketones and (thiourea/N-phenylthiourea in presence of lanthanum triflate catalyst. This methodology allowed us to achieve the products in excellent yield by stirring at room temperature. All the synthesized compounds were investigated against a representative panel of pathogenic strains using broth microdilution MIC (minimum inhibitory concentration method for their in vitro antimicrobial activity. Amongst these sets of heterocyclic compounds 5h, 6b, 6h, 5f, 5l, 5n and 6g found to have admirable activity.

  14. Chemical Composition and Antimicrobial Activities of Essential Oils from Nepeta cataria L. against Common Causes of Food-Borne Infections

    OpenAIRE

    Zomorodian, Kamiar; Saharkhiz, Mohammad Jamal; Shariati, Samaneh; Pakshir, Keyvan; Rahimi, Mohammad Javad; Khashei, Reza

    2012-01-01

    Nepeta cataria L. is traditionally consumed as a food additive. The effects of three different harvest stages of N. cataria essential oils (EOs) against most common causes of food-borne infections were evaluated by broth microdilution method as recommended by the Clinical and Laboratory Standards Institute (CLSI). The chemical composition of the EOs from N. cataria has been analyzed by gas chromatography/mass spectrometry (GC/MS). The analysis of the EOs indicated that 4a- α ,7- α ,7a- β -nep...

  15. Vyhodnocení aktivity potenciálně antibakteriálních látek pomocí mikrodiluční bujónové metody I

    OpenAIRE

    Navrátilová, Kristýna

    2010-01-01

    Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Study program: Pharmacy Candidate: Kristýna Navrátilová Supervisor: Mgr. Marcela Vejsová, Ph.D. Title of diploma thesis: Evaluation of activity of potentional antibacterial substan- ces through the use of microdilution broth method I Background Development of new antibacterial agents is still and will be always an impor- tant area of pharmaceutical industry. The need to discover ne...

  16. In vitro potency evaluations of various piperacillin/tazobactam generic products compared with the contemporary branded (Zosyn, Wyeth) formulation.

    Science.gov (United States)

    Jones, Ronald N; Fritsche, Thomas R; Moet, Gary J

    2008-05-01

    Twenty-three generic intravenous piperacillin/tazobactam products were compared for in vitro activity to the branded formulation (Zosyn, Wyeth, Philadelphia, PA) by disk diffusion and incremental broth microdilution assay methods. All but 1 lot demonstrated significantly decreased activity (-5 to -35%), necessitating further investigations regarding the chemical purity, potency, and therapeutic equivalence of these products worldwide. The average -16% activity across all generic lots was equivalent to underdosing piperacillin/tazobactam by 2.6 g daily for serious clinical infections (4.5 g Q6 h).

  17. Isolation of Mycobacterium kumamotonense from a patient with pulmonary infection and latent tuberculosis

    Directory of Open Access Journals (Sweden)

    Fanourios Kontos

    2016-01-01

    Full Text Available Mycobacterium kumamotonense is a novel, slow-growing non-chromogenic nontuberculous mycobacterium, which belongs to Mycobacterium terrae complex. We report, for the first time in Greece, the isolation of M. kumamotonense from an immunocompetent patient with pulmonary infection and latent tuberculosis. M. kumamotonense was identified by sequencing analysis of 16S rDNA and 65-kDa heat shock protein genes while by commercial molecular assays it was misidentified as Mycobacterium celatum. Antibiotic susceptibility testing was performed by the reference broth microdilution method. The strain was susceptible to amikacin, clarithromycin, rifampin, ciprofloxacin, moxifloxacin, rifabutin, ethambutol and linezolid.

  18. In Vitro Activities of New Antimicrobials against Nocardia brasiliensis

    Science.gov (United States)

    Vera-Cabrera, Lucio; Gonzalez, Eva; Choi, Sung H.; Welsh, Oliverio

    2004-01-01

    The in vitro sensitivities of 30 strains of Nocardia brasiliensis to DA-7867, gatifloxacin, moxifloxacin, and BMS-284756 (garenoxacin) were determined using the broth microdilution method. All N. brasiliensis strains were sensitive to these antimicrobials. The most active drug in vitro was DA-7867, with a MIC at which 90% of the isolates tested were inhibited of 0.03 μg/ml and a MIC at which 50% of the isolates tested were inhibited of 0.06 μg/ml. PMID:14742215

  19. Antimicrobial susceptibilities and clinical sources of Facklamia species.

    Science.gov (United States)

    LaClaire, L; Facklam, R

    2000-08-01

    Facklamia spp. are gram-positive cocci, arranged in short chains or diplos, and resemble viridans streptococci on 5% sheep blood agar. Eighteen strains representing four species of Facklamia were isolated from blood cultures, an abscess, bone, cerebrospinal fluid, gall bladder, vaginal swab, and one unknown source. Cultures were tested against 15 antimicrobial agents by using the broth microdilution MIC method. Reduced susceptibilities to the beta lactams, erythromycin, clindamycin, trimethoprim-sulfamethoxazole, and tetracycline were found. These results indicate that the susceptibilities of the Facklamia species are varied and that some strains have resistance patterns which may present difficulty in managing systemic infections in patients.

  20. Acremonium species: new emerging fungal opportunists--in vitro antifungal susceptibilities and review.

    Science.gov (United States)

    Guarro, J; Gams, W; Pujol, I; Gené, J

    1997-11-01

    We provide an overview of opportunistic fungal infections caused by Acremonium (Cephalosporium) species and discuss the classification of these species as well as the diagnosis and treatment of acremonium infections. We used a microdilution broth method to compare in vitro susceptibilities and minimum inhibitory concentrations and minimum fungicidal concentrations of amphotericin B, miconazole, itraconazole, 5-fluorocytosine, fluconazole, and ketoconazole for 33 clinical and environmental isolates of Acremonium. In general, the isolates tested displayed little susceptibility to the antifungals tested. Fluconazole and 5-fluorocytosine were ineffective in all cases. The efficacy of the remaining drugs was dependent on the strain. Amphotericin B showed the best results.

  1. Evaluation of antibacterial activity of extracts of five species of wood-colonizing fungi.

    Science.gov (United States)

    Janes, Damjan; Umek, Andrej; Kreft, Samo

    2006-01-01

    Screening new organisms for antibacterial activity and searching for new antibacterial drugs is important due to the constant generation of new antibiotic-resistant strains of pathogenic bacteria. An E. coli broth microdilution test was used to evaluate the results of the Vibrio fischeri bioluminescence test in five of the most antibacterially active species of wood-colonizing fungi. Serpula lacrymans was found to be a potential source of thermostable antibiotic(s) and the Vibrio fischeri bioluminescence test was confirmed to be a useful method for screening for antibacterial activity.

  2. Beneficial effects of the ethanol extract from the dry matter of a culture broth of Inonotus obliquus in submerged culture on the antioxidant defence system and regeneration of pancreatic beta-cells in experimental diabetes in mice.

    Science.gov (United States)

    Xu, Hong-Yu; Sun, Jun-En; Lu, Zhen-Ming; Zhang, Xiao-Mei; Dou, Wen-Fang; Xu, Zheng-Hong

    2010-04-01

    The antihyperglycaemic and antilipidperoxidative effects of the ethanol extract from the dry matter of a culture broth (DMCB) of Inonotus obliquus were investigated in alloxan-induced diabetic mice and the possible mechanism of action was also discussed. In alloxan-induced diabetic mice, treatment with the ethanol extract from DMCB of I. obliquus (30 and 60 mg kg(-1) body weight (b.w.) for 21 days) showed a significant decrease in blood glucose level: the percentage reductions on the 7th day were 11.54 and 11.15%, respectively. However, feeding of this drug for three weeks produced reduction of 22.51 and 24.32%. Furthermore, the ethanol extract from the DMCB of I. obliquus treatment significantly decreased serum contents of free fatty acids, total cholesterol, triglycerides and low-density lipoprotein-cholesterol, whereas it effectively increased high-density lipoprotein-cholesterol, insulin levels and hepatic glycogen contents in livers of diabetic mice. Besides this, the ethanol extracts from the DMCB treatment significantly increased catalase, superoxide dismutase and glutathione peroxidase activities, except for decreasing the maleic dialdehyde level in diabetic mice. Histological morphology examination showed that the ethanol extract from the DMCB of I. obliquus restored the damage of pancreatic tissues in mice with diabetes mellitus. The results showed that the ethanol extract from the DMCB of I. obliquus possesses significant antihyperglycaemic, antilipidperoxidative and antioxidant effects in alloxan-induced diabetic mice.

  3. Influence of aerobic and anaerobic conditions on survival of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in Luria-Bertani broth, farm-yard manure and slurry.

    Science.gov (United States)

    Semenov, Alexander V; van Overbeek, Leo; Termorshuizen, Aad J; van Bruggen, Ariena H C

    2011-03-01

    The influence of aerobic and anaerobic conditions on the survival of the enteropathogens Escherichia coli O157:H7 and Salmonella serovar Typhimurium was investigated in microcosms with broth, cattle manure or slurry. These substrates were inoculated with a green fluorescent protein transformed strain of the enteropathogens at 10(7) cells g(-1) dry weight. Survival data was fitted to the Weibull model. The survival curves in aerobic conditions generally showed a concave curvature, while the curvature was convex in anaerobic conditions. The estimated survival times showed that E. coli O157:H7 survived significantly longer under anaerobic than under aerobic conditions. Survival ranged from approximately. 2 weeks for aerobic manure and slurry to more than six months for anaerobic manure at 16 °C. On average, in 56.3% of the samplings, the number of recovered E. coli O157:H7 cells by anaerobic incubation of Petri plates was significantly (p manure as well as between aerobic and anaerobic incubation of Petri dishes. The importance of changes in microbial community and chemical composition of manure and slurry was distinguished for the survival of E. coli O157:H7 in different oxygen conditions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Carvacrol and 1,8-cineole alone or in combination at sublethal concentrations induce changes in the cell morphology and membrane permeability of Pseudomonas fluorescens in a vegetable-based broth.

    Science.gov (United States)

    de Sousa, Jossana Pereira; Torres, Rayanne de Araújo; de Azerêdo, Geíza Alves; Figueiredo, Regina Célia Bressan Queiroz; Vasconcelos, Margarida Angélica da Silva; de Souza, Evandro Leite

    2012-08-01

    This study aimed to investigate the effects of sublethal concentrations of carvacrol (CAR) and 1,8-cineole (CIN) alone and in combination on the morphology, cell viability and membrane permeability of Pseudomonas fluorescens ATCC 11253 cultivated in a vegetable-based broth. Transmission and scanning electron microscopy images of bacterial cells exposed to CAR and CIN alone or in combination showed marked ultrastructural changes after 1h of exposure. These changes included shrunken protoplasm, discontinuity of the outer and cytoplasmic membranes and leakage of the intracellular material. Confocal scanning laser microscopy images corroborated the electron microscopy data, showing a decrease in the number of SYTO-9 cells (intact cells) with a concomitant increase in the number of PI-positive cells (dead cells). All of these morphological changes are indicative of increased membrane permeability and the loss of bacterial envelope integrity, which ultimately lead to cell death. The combination of sublethal concentrations of CAR and CIN could be applied to inhibit the growth of P. fluorescens on vegetables. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. The potential of mycelium and culture broth of Lignosus rhinocerotis as substitutes for the naturally occurring sclerotium with regard to antioxidant capacity, cytotoxic effect, and low-molecular-weight chemical constituents.

    Directory of Open Access Journals (Sweden)

    Beng Fye Lau

    Full Text Available Previous studies on the nutritional and nutraceutical properties of Lignosus rhinocerotis focused mainly on the sclerotium; however, the supply of wild sclerotium is limited. In this investigation, the antioxidant capacity and cytotoxic effect of L. rhinocerotis cultured under different conditions of liquid fermentation (shaken and static were compared to the sclerotium produced by solid-substrate fermentation. Aqueous methanol extracts of the mycelium (LR-MH, LR-MT and culture broth (LR-BH, LR-BT demonstrated either higher or comparable antioxidant capacities to the sclerotium extract (LR-SC based on their radical scavenging abilities, reducing properties, metal chelating activities, and inhibitory effects on lipid peroxidation. All extracts exerted low cytotoxicity (IC50>200 µg/ml, 72 h against selected mammalian cell lines. Several low-molecular-weight compounds, including sugars, fatty acids, methyl esters, sterols, amides, amino acids, phenolics, and triterpenoids, were identified using GC-MS and UHPLC-ESI-MS/MS. The presence of proteins (<40 kDa in the extracts was confirmed by SDS-PAGE and SELDI-TOF-MS. Principal component analysis revealed that the chemical profiles of the mycelial extracts under shaken and static conditions were distinct from those of the sclerotium. Results from bioactivity evaluation and chemical profiling showed that L. rhinocerotis from liquid fermentation merits consideration as an alternative source of functional ingredients and potential substitute for the sclerotium.

  6. Quantifying antimicrobial resistance at veal calf farms.

    Directory of Open Access Journals (Sweden)

    Angela B Bosman

    Full Text Available This study was performed to determine a sampling strategy to quantify the prevalence of antimicrobial resistance on veal calf farms, based on the variation in antimicrobial resistance within and between calves on five farms. Faecal samples from 50 healthy calves (10 calves/farm were collected. From each individual sample and one pooled faecal sample per farm, 90 selected Escherichia coli isolates were tested for their resistance against 25 mg/L amoxicillin, 25 mg/L tetracycline, 0.5 mg/L cefotaxime, 0.125 mg/L ciprofloxacin and 8/152 mg/L trimethoprim/sulfamethoxazole (tmp/s by replica plating. From each faecal sample another 10 selected E. coli isolates were tested for their resistance by broth microdilution as a reference. Logistic regression analysis was performed to compare the odds of testing an isolate resistant between both test methods (replica plating vs. broth microdilution and to evaluate the effect of pooling faecal samples. Bootstrap analysis was used to investigate the precision of the estimated prevalence of resistance to each antimicrobial obtained by several simulated sampling strategies. Replica plating showed similar odds of E. coli isolates tested resistant compared to broth microdilution, except for ciprofloxacin (OR 0.29, p ≤ 0.05. Pooled samples showed in general lower odds of an isolate being resistant compared to individual samples, although these differences were not significant. Bootstrap analysis showed that within each antimicrobial the various compositions of a pooled sample provided consistent estimates for the mean proportion of resistant isolates. Sampling strategies should be based on the variation in resistance among isolates within faecal samples and between faecal samples, which may vary by antimicrobial. In our study, the optimal sampling strategy from the perspective of precision of the estimated levels of resistance and practicality consists of a pooled faecal sample from 20 individual animals, of which

  7. Comparison of 3 culture methods and PCR assays for Salmonella gallinarum and Salmonella pullorum detection in poultry feed.

    Science.gov (United States)

    Soria, M Cecilia; Soria, Mario A; Bueno, Dante J; Terzolo, Horacio R

    2013-06-01

    To detect Salmonella gallinarum or Salmonella pullorum in artificially contaminated poultry feed, 9 culture combinations were compared, including 3 preenrichment/enrichment methods (tryptic soy broth plus ferrous sulfate/tetrathionate Hajna, tryptic soy broth plus ferrous sulfate/selenite cystine broth, and Salmosyst) in combination with 3 selective agars (xylose lysine desoxicholate agar added with tergitol 4, EF-18, and Önöz), respectively. Additionally, a single PCR technique was applied combined with 2 different preenrichment media (tryptic soy broth plus ferrous sulfate and Salmosyst). The specificity and positive predictive value were 1 for all methods. There were some differences among Salmonella strains for sensitivity and accuracy in the culture and Salmosyst-PCR methods. The sensitivity and accuracy values were less than 0.60 and 0.64, respectively, whereas the negative predictive values were between 0.12 and 0.23. Two PCR methods did not show any difference in the parameters of performance evaluated. Kappa coefficients showed good agreement between both methods. None of the culture combinations was able to detect S. gallinarum or S. pullorum when the inoculum was less than 3 × 10² cfu/25 g, except the Salmosyst broth method, which could recover S. gallinarum from 3 × 10¹ cfu/25 g onward. Overall, there were differences in the detection limits among the strains and methods used. In general, the 3 selective plating media did not show any significant difference in the parameters of performance studied for each strain. On the other hand, the agreements were slight to fair when culture methods were compared among them and with both PCR methods. The differences in the detection levels that were obtained using these methods and the difficulty in detecting S. gallinarum or S. pullorum in feed represent a potential problem when a poultry feed sample is considered to be negative. It is highly recommended to use at least 2 methods to increase the chances of

  8. Pervaporation of ethanol from lignocellulosic fermentation broth

    NARCIS (Netherlands)

    Gaykawad, S.S.; Zha, Y.; Punt, P.J.; Groenestijn, J.W. van; Wielen, L.A.M. van der; Straathof, A.J.J.

    2013-01-01

    Pervaporation can be applied in ethanol production from lignocellulosic biomass. Hydrophobic pervaporation, using a commercial PDMS membrane, was employed to concentrate the ethanol produced by fermentation of lignocellulosic hydrolysate. To our knowledge, this is the first report describing this.

  9. Rosmarinus officinalis L. essential oil and the related compound 1,8-cineole do not induce direct or cross-protection in Listeria monocytogenes ATCC 7644 cultivated in meat broth.

    Science.gov (United States)

    Gomes Neto, Nelson Justino; Luz, Isabelle Silva; Honório, Wanessa Gonçalves; Tavares, Adassa Gama; de Souza, Evandro Leite

    2012-08-01

    Listeria monocytogenes has the capability of adapting to 1 or more antimicrobial compounds or procedures applied by the food industry to control the growth and survival of microorganisms in foods. In this study, the effects of Rosmarinus officinalis essential oil (EO) and the related compound 1,8-cineole on the inhibition of the growth and survival of L. monocytogenes ATCC 7644 were determined. The ability of the R. officinalis EO and 1,8-cineole to induce direct and cross-protection of bacteria against various stresses (lactic acid, pH 5.2; NaCl, 3 g/100 mL; high temperature, 45 °C) was also determined. At all concentrations tested (minimum inhibitory concentration (MIC), ½ MIC, and ¼ MIC), both compounds inhibited the cell viability of L. monocytogenes over 120 min of exposure. Overnight exposure of L. monocytogenes to sublethal amounts of either the R. officinalis EO or 1,8-cineole in meat broth revealed no induction of direct or cross-protection against lactic acid, NaCl, or high temperature. Similarly, cells subjected to 24 h cycles of adaptation with increasing amounts (½ MIC to 2× MIC) of the EO and 1,8-cineole showed no increase in direct tolerance, as they were able to survive in growth medium containing up to ½ MIC of either substance. These results show the antimicrobial efficacy of R. officinalis EO and 1,8-cineole for use in systems, particularly as anti-L. monocytogenes compounds.

  10. A rapid method for the determination of microbial susceptibility using the firefly luciferase assay for adenosine triphosphate (ATP)

    Science.gov (United States)

    Vellend, H.; Tuttle, S. A.; Barza, M.; Weinstein, L.; Picciolo, G. L.; Chappelle, E. W.

    1975-01-01

    Luciferase assay for adenosine triphosphate (ATP) was optimized for pure bacteria in broth in order to evaluate if changes in bacterial ATP content could be used as a rapid measure of antibiotic effect on microorganisms. Broth cultures of log phase bacteria were incubated at 310 K (37 C) for 2.5 hours at antimicrobial concentrations which resulted in the best discrimination between sensitive and resistant strains. Eighty-seven strains of 11 bacterial species were studied for their susceptibility to 12 commonly used antimicrobial agents: ampicillin, Penicillin G, nafcillin, carbenicillin, cephalothin, tetracycline, erythromycin, clindamycin, gentamicin, nitrofurantoin, colistin, and chloramplenicol. The major advantage of the ATP system over existing methods of rapid microbial susceptibility testing is that the assay can be made specific for bacterial ATP.

  11. An improved dynamic method to measure kL a in bioreactors.

    Science.gov (United States)

    Damiani, Andrew L; Kim, Min Hea; Wang, Jin

    2014-10-01

    An accurate measurement or estimation of the volumetric mass transfer coefficient kL a is crucial for the design, operation, and scale up of bioreactors. Among different physical and chemical methods, the classical dynamic method is the most widely applied method to simultaneously estimate both kL a and cell's oxygen utilization rate. Despite several important follow-up articles to improve the original dynamic method, some limitations exist that make the classical dynamic method less effective under certain conditions. For example, for the case of high cell density with moderate agitation, the dissolved oxygen concentration barely increases during the re-gassing step of the classical dynamic method, which makes kL a estimation impossible. To address these limitations, in this work we present an improved dynamic method that consists of both an improved model and an improved procedure. The improved model takes into account the mass transfer between the headspace and the broth; in addition, nitrogen is bubbled through the broth when air is shut off. The improved method not only enables a faster and more accurate estimation of kL a, but also allows the measurement of kL a for high cell density with medium/low agitation that is impossible with the classical dynamic method. Scheffersomyces stipitis was used as the model system to demonstrate the effectiveness of the improved method; in addition, experiments were conducted to examine the effect of cell density and agitation speed on kL a. © 2014 Wiley Periodicals, Inc.

  12. Comparison of methods to detect Pasteurella multocida in carrier waterfowl

    Science.gov (United States)

    Samuel, M.D.; Shadduck, D.J.; Goldberg, Diana R.; Johnson, W.P.

    2003-01-01

    We conducted laboratory challenge trials using mallard ducks (Anas platyrhynchos) to compare methods for detecting carriers of Pasteurella multocida, the bacterium that causes avian cholera, in wild birds. Birds that survived the initial infection were euthanized at 2-4 wk intervals up to 14 wk post challenge. Isolates of P. multocida were obtained at necropsy from 23% of the birds that survived initial infection. We found that swab samples (oral, cloacal, nasal, eye, and leg joint) were most effective for detecting carrier birds up to 14 wk post infection. No detectable differences in isolation were observed for samples stored in either 10% dimethysulfoxide or brain heart infusion broth. The frequency of detecting carriers in our challenge trials appeared to be related to mortality rates observed during the trial, but was not related to a number of other factors including time after challenge, time delays in collecting tissues postmortem, and route of infection. In our trials, there was little association between antibody levels and carrier status. We concluded that swabs samples collected from recently dead birds, stored in liquid nitrogen, and processed using selective broth provide a feasible field method for detecting P. multocida carriers in wild waterfowl.

  13. Antifungal activity of the honeybee products against Candida spp. and Trichosporon spp.

    Science.gov (United States)

    Koç, Ayşe Nedret; Silici, Sibel; Kasap, Filiz; Hörmet-Oz, Hatice Tuna; Mavus-Buldu, Hikmet; Ercal, Bariş Derya

    2011-01-01

    Honeybee products (honey, royal jelly, pollen, and propolis) were evaluated for their ability to inhibit the growth of 40 yeast strains of Candida albicans, Candida glabrata, Candida krusei, and Trichosporon spp. The broth microdilution method was used to assess the antifungal activity of honeybee products against yeasts. Fluconazole was selected as the antifungal control agent. Using the broth microdilution method, minimal inhibitory concentration ranges with regard to all isolates were 5-80% (vol/vol), 0.06-1 μg/mL, 0.002-0.25 μg/mL, 0.006-0.1 μg/mL, and 0.02-96 μg/mL for honey, royal jelly, pollen, propolis, and fluconazole, respectively. The antifungal activities of each product decreased in the following order: propolis >pollen > royal jelly > > honey. This study demonstrated that honeybee products, particularly propolis and pollen, can help to control some fluconazole-resistant fungal strains.

  14. A cryopreservation method for Pasteurella multocida from wetland samples

    Science.gov (United States)

    Moore, Melody K.; Shadduck, D.J.; Goldberg, D.R.; Samuel, M.D.

    1998-01-01

    A cryopreservation method and improved isolation techniques for detection of Pasteurella multocida from wetland samples were developed. Wetland water samples were collected in the field, diluted in dimethyl sulfoxide (DMSO, final concentration 10%), and frozen at -180 C in a liquid nitrogen vapor shipper. Frozen samples were transported to the laboratory where they were subsequently thawed and processed in Pasteurella multocida selective broth (PMSB) to isolate P. multocida. This method allowed for consistent isolation of 2 to 18 organisms/ml from water seeded with known concentrations of P. multocida. The method compared favorably with the standard mouse inoculation method and allowed for preservation of the samples until they could be processed in the laboratory.

  15. Comparação de Meios de Enriquecimento e de Plaqueamento Utilizados na Pesquisa de Salmonella em Carcaças de Frango e Fezes de Aves Comparison of Different Enrichment Broth and Plating Media Used to Isolating Salmonella from Chicken Carcasses and Poultry Faeces Samples

    Directory of Open Access Journals (Sweden)

    MS Nascimento

    2000-04-01

    Full Text Available Este trabalho foi desenvolvido para avaliar, comparativamente, os caldos de enriquecimento Rapapport-novobiocina (RVN, selenito-cistinanovobiocina (SCN e tetrationato-novobiocina (TN e os meios para plaqueamento ágar Hektoen (HE, ágar MacConkey (MC, ágar Salmonella-Shigella (SS, ágar verde brilhante (VB e ágar xilose lisina desoxicolato (XLD, utilizados no isolamento de Salmonella em carcaças de frango e fezes de aves. O procedimento bacteriológico consistiu das etapas de pré-enriquecimento, enriquecimento em caldos seletivos, plaqueamento, testes bioquímicos presuntivos e confirmação sorológica com soros polivalentes anti antígenos somáticos e flagelares de Salmonella.. As fezes foram experimentalmente contaminadas com 8 sorotipos de Salmonella (Agona, Anatum, Enteritidis, Havana, Infantis, Owakam, Schwazengrund e Typhimurium e a concentração final foi aproximadamente de 1,2 x 10² ufc/g. As fezes foram inoculadas nos caldos enriquecedores e a partir daí, seguiu-se o mesmo procedimento utilizado para as carcaças. Os resultados referentes às carcaças de frango não foram estatisticamente diferentes (p>0,01 para os caldos e as placas. Todavia, verificou-se superioridade numérica em relação aos caldos SCN e TN sobre o caldo RVN, e em relação ao ágar XLD sobre os demais. Verificou-se também que com o emprego de dois caldos de enriquecimento e de dois meios para plaqueamento pode-se obter maior positividade. Quanto ao exame das fezes, o caldo TN mostrou-se superior aos demais (p>0,01, não havendo diferença (p>0,01 de resultados para os meios de plaqueamento. Os resultados sugerem que a utilização de mais de um meio de enriquecimento e de plaqueamento poderia aumentar as chances de isolamento de Salmonella.This study was undertaken to compare selenite-cystine-novobiocin (SCN broth, tetrationate-novobiocin (TN broth and Rappaport-Vassiliadisnovobiocin (RVN broth as enrichment and MacConkey (MC agar, brilliant green (BG

  16. Assessment of the antifungal susceptibility of Malassezia pachydermatis in various media using a CLSI protocol.

    Science.gov (United States)

    Cafarchia, Claudia; Figueredo, Luciana A; Favuzzi, Vincenza; Surico, Mariannna R; Colao, Valeriana; Iatta, Roberta; Montagna, Maria Teresa; Otranto, Domenico

    2012-10-12

    The microdilution antifungal method (CLSI BMD, M27-A3) was used for testing the antifungal susceptibility of Malassezia species. However, optimal broth media that allow sufficient growth of M. pachydermatitis and produce reliable and reproducible MICs using the CLSI BMD protocol are yet to be established. In this study, the susceptibility of M. pachydermatis isolates to ketoconazole (KTZ), itraconazole (ITZ) and fluconazole (FLZ) was evaluated in vitro by the CLSI BMD test using Christensen's urea broth (CUB) and mRPMI 1640 containing lipid supplementation, Sabouraud dextrose broth with 1% tween 80 (SDB), and Dixon broth (DXB). A FLZ-resistant M. pachydermatis was generated in vitro and tested under the same conditions. A good growth of M. pachydermatis incubated for 48 and 72 h, respectively, was observed in CUB, SDB and DXB and not in mRPMI 1640 (p64 mg/L was observed only when the FLZ-resistant M. pachydermatis isolate was tested in SDB. Based on the results obtained herein, culture in SDB, stock inoculum suspensions of 1-5 × 10(6)CFU/ml, and an incubation time of 48 h are proposed as optimal conditions for the evaluation of the in vitro antifungal susceptibility of M. pachydermatis using a modified CLSI BMD protocol. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2017-04-01

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

  18. Performance of EUCAST and CLSI approaches for co-amoxiclav susceptibility testing conditions for clinical categorization of a collection of Escherichia coli isolates with characterized resistance phenotypes.

    Science.gov (United States)

    Díez-Aguilar, María; Morosini, María-Isabel; López-Cerero, Lorena; Pascual, Álvaro; Calvo, Jorge; Martínez-Martínez, Luis; Marco, Francesc; Vila, Jordi; Ortega, Adriana; Oteo, Jesús; Cantón, Rafael

    2015-08-01

    There are different methodological recommendations for in vitro testing of the co-amoxiclav combination. Performance of co-amoxiclav MIC testing for Escherichia coli by the standard ISO microdilution method (ISO 20776-1) was compared using EUCAST (fixed 2 mg/L clavulanate concentration) and CLSI (2 : 1 ratio) interpretive criteria. MICs were determined by broth microdilution using a 2 : 1 ratio and fixed clavulanate concentrations (2 and 4 mg/L) for 160 clinical E. coli isolates with characterized resistance mechanisms. Essential agreements, categorical agreements and relative errors were determined. For all isolates, essential agreement between microdilution using 2 mg/L clavulanate and a 2 : 1 ratio was 25.6%. For ESBL-producing isolates, considering EUCAST breakpoints, 55% of isolates tested with 2 mg/L clavulanate were classified as resistant; conversely, 95% of isolates tested with 4 mg/L clavulanate were susceptible. When using CLSI breakpoints and a 2 : 1 ratio, 90% of isolates were susceptible and 10% were intermediate. Variation in the clavulanate concentration gave different susceptibility testing results, particularly among ESBL-producing E. coli isolates. The in vitro concentration of clavulanate that better correlates with clinical outcome is still under debate and should be established. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Consequences of switching from a fixed 2 : 1 ratio of amoxicillin/clavulanate (CLSI) to a fixed concentration of clavulanate (EUCAST) for susceptibility testing of Escherichia coli.

    Science.gov (United States)

    Leverstein-van Hall, Maurine A; Waar, Karola; Muilwijk, Jan; Cohen Stuart, James

    2013-11-01

    The CLSI recommends a fixed 2 : 1 ratio of co-amoxiclav for broth microdilution susceptibility testing of Enterobacteriaceae, while EUCAST recommends a fixed 2 mg/L clavulanate concentration. The aims of this study were: (i) to determine the influence of a switch from CLSI to EUCAST methodology on Escherichia coli susceptibility rates; (ii) to compare susceptibility results obtained using EUCAST-compliant microdilution with those from disc diffusion and the Etest; and (iii) to evaluate the clinical outcome of patients with E. coli sepsis treated with co-amoxiclav in relation to the susceptibility results obtained using either method. Resistance rates were determined in three laboratories that switched from CLSI to EUCAST cards with the Phoenix system (Becton Dickinson) as well as in 17 laboratories that continued to use CLSI cards with the VITEK 2 system (bioMérieux). In one laboratory, isolates were simultaneously tested by both the Phoenix system and either disc diffusion (n = 471) or the Etest (n = 113). Medical and laboratory records were reviewed for E. coli sepsis patients treated with co-amoxiclav monotherapy. Only laboratories that switched methodology showed an increase in resistance rates - from 19% in 2010 to 31% in 2011 (P CLSI methodology, but correlated better with clinical outcome. EUCAST-compliant microdilution and disc diffusion provided discrepant results.

  20. Clonal dissemination of multilocus sequence type 11 Klebsiella pneumoniae carbapenemase - producing K. pneumoniae in a Chinese teaching hospital.

    Science.gov (United States)

    Sun, Kangde; Chen, Xu; Li, Chunsheng; Yu, Zhongmin; Zhou, Qi; Yan, Yuzhong

    2015-02-01

    Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae has disseminated rapidly in China. We aimed to analyze the molecular epidemiology of four KPC-producing K. pneumoniae strains isolated from a suspected clonal outbreak during a 3-month period and to track the dissemination of KPC-producing K. pneumonia retrospectively. We created antimicrobial susceptibility profiles using an automated broth microdilution system and broth microdilution methods. We screened carbapenemase and KPC phenotypes using the modified Hodge test and meropenem-boronic acid (BA) disk test, respectively. We identified β-lactamase genes with PCR and sequencing. We investigated clonal relatedness for epidemiological comparison using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). All isolates expressed multidrug resistance and yielded positive results for the modified Hodge and meropenem-BA disk tests. The isolates all carried blaKPC -2 , and coproduced CTX-M-type extended-spectrum β-lactamase. PFGE and MLST showed that the isolates were clonally related. The PFGE patterns of these isolates had ≥90% similarity. We found a single clone, sequence type (ST) 11, and its typical dissemination mode resembled clonal spread. The dissemination of KPC-producing K. pneumoniae is clonally related and there is probable local transmission of a successful ST11 clone. © 2014 APMIS. Published by John Wiley & Sons Ltd.

  1. In vitro study on the antimicrobial effect of hydroalcoholic extracts from Mentha arvensis L. (Lamiaceae against oral pathogens - doi: 10.4025/actascibiolsci.v34i4.8959

    Directory of Open Access Journals (Sweden)

    Francisco Augusto Burkert Del Pino

    2012-09-01

    Full Text Available In vitro tests could be a valuable tool for the evaluation of medicinal plants’ antimicrobial activity. Mentha arvensis of the Lamiaceae family is one of the most frequently traditional plants used in Brazil. Hydroalcoholic extracts of M. arvensis were analyzed for antimicrobial activity on Streptococcus mutans, Streptococcus sobrinus and Candida albicans. Three different assays (agar diffusion, broth macro- and micro-dilution methods were used to evaluate antimicrobial activity. Although hydroalcoholic extracts of M. arvensis did not show any antibacterial effect, its antifungal activity against C. albicans was revealed. According to the micro-dilution broth assay, MIC of the hydroalcoholic extract from leaves of M. arvensis on Candida albicans strains ranged between 625 and 2500 mg mL-1. Results suggest that M. arvensis hydroalcoholic extract may be considered a potentially antifungal agent against C. albicans, and a possible item for human antibiotic therapy.  However, further biological tests on the plant’s efficacy and side-effects are necessary before its use on humans.  

  2. Evaluation of VIDAS Salmonella (SLM) easy Salmonella method for the detection of Salmonella in a variety of foods: collaborative study.

    Science.gov (United States)

    Crowley, Erin; Bird, Patrick; Fisher, Kiel; Goetz, Katherine; Benzinger, M Joseph; Agin, James; Goins, David; Johnson, Ronald L

    2011-01-01

    The VIDAS Salmonella (SLM) Easy Salmonella method is a specific enzyme-linked fluorescent immunoassay performed in the automated VIDAS instrument. The VIDAS Easy Salmonella method is a simple 2-step enrichment procedure, using pre-enrichment followed by selective enrichment in a newly formulated broth, SX2 broth. This new method was compared in a multilaboratory collaborative study to the U.S. Food and Drug Administration's Bacteriological Analytical Manual, Chapter 5 method for five food matrixes (liquid egg, vanilla ice cream, spinach, raw shrimp, and peanut butter) and the U.S. Department of Agriculture's Microbiology Laboratory Guidebook 4.04 method for deli turkey. Each food type was artificially contaminated with Salmonella at three inoculation levels. A total of 15 laboratories representing government, academia, and industry, throughout the United States, participated. In this study, 1583 samples were analyzed, of which 792 were paired replicates and 791 were unpaired replicates. Of the 792 paired replicates, 285 were positive by both the VIDAS and reference methods. Of the 791 unpaired replicates, 341 were positive by the VIDAS method and 325 were positive by the cultural reference method. A Chi-square analysis of each of the six food types was performed at the three inoculation levels tested. For all foods evaluated, the VIDAS Easy SLM method demonstrated results comparable to those of the reference methods for the detection of Salmonella.

  3. A SYBR®Green-based real-time PCR method for improved detection of mcr-1-mediated colistin resistance in human stool samples.

    Science.gov (United States)

    Donà, Valentina; Bernasconi, Odette J; Kasraian, Sara; Tinguely, Regula; Endimiani, Andrea

    2017-06-01

    The aim of this study was to design a rapid and sensitive real-time PCR (rt-PCR) method for colistin resistance mcr-1 gene detection in human faecal samples. Stools (n=88) from 36 volunteers were analysed. To isolate mcr-1-producing Enterobacteriaceae, samples were enriched overnight in Luria-Bertani (LB) broth containing 2mg/L colistin and were then plated on selective agar plates with 4mg/L colistin. A SYBR ® Green-based rt-PCR targeting mcr-1 was then designed. For method validation and to establish the limit of detection (LOD), total DNA was extracted from mcr-1-negative and mcr-1-positive Escherichia coli. rt-PCR was also performed with DNA extracted from 88 native stools and after enriching them in LB broth containing colistin. Based on the culture approach, three unique volunteers resulted colonised with mcr-1-harboring E. coli strains. For culture isolates, rt-PCR exhibited a LOD of 10 genomic copies/reaction, with both sensitivity and specificity of 100%. Nevertheless, when testing native stools, only two of the three mcr-1-positive specimens were detected. However, after enrichment in LB broth containing colistin, the rt-PCR was strongly positive for all culture-positive samples. The average cycle threshold was 22, granting rapid and confident detection of positive specimens within 30 cycles. No false positives were observed for the remaining 85 culture-negative specimens. A rapid rt-PCR for detection of mcr-1 from stool specimens was developed. The detection rate was increased by testing selective broth enrichments. This approach also has the advantage of concomitant isolation of mcr-1-harboring strains for further antimicrobial susceptibility and genetic testing. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  4. Method for detecting production of zearalenone, zearalenol, T-2 toxin, and deoxynivalenol by Fusarium isolates.

    Science.gov (United States)

    Richardson, K E; Hagler, W M; Hamilton, P B

    1984-01-01

    Three methods for detecting toxigenic fusaria in culture were compared by using known producers of zearalenone, zearalenol, T-2 toxin, and deoxynivalenol. Moist, autoclaved rice cultures of known toxigenic isolates grown in 20-ml tubes yielded oily extracts containing compounds which interfered with qualitative and quantitative analysis for the mycotoxins. Vermiculite moistened with nutrient broth in 20-ml tubes yielded a much cleaner extract. Growing the fungi on a liquid medium required a shorter incubation period, but yields of T-2 toxin and deoxynivalenol were low and variable, and the method required greater space in the incubator. Screening of the extracts by thin-layer chromatography with colorimetric spray reagents to detect the presence of these toxins permitted reduction in the number of extracts quantified by the more lengthy gas-liquid chromatographic method. Culturing in nutrient broth on vermiculite in tubes coupled to a qualitative screen before quantitation proved to be a convenient, inexpensive, and relatively rapid method that enabled reliable screening of a large number of Fusarium isolates for toxin production as compared with prior methods. PMID:6232897

  5. [Activity of voriconazole against yeasts isolated from blood culture determined by two methods].

    Science.gov (United States)

    Cantón, E; Pemán, J; Bosch, M; Viudes, A; Gobernado, M

    2005-12-01

    The in vitro activity of voriconazole has been determined by two methods: the reference M27-A2 and the marketed Sensititre YeastOne microdilution colorimetric method. The agreement (+/-2 dilutions) and correlation between methods as well as the percentage of errors has been determined. A total of 144 yeasts (47 Candida albicans, 52 C. parapsilosis, 13 C. tropicalis, 10 C. krusei, 9 C. glabrata, 2 C. guilliermondii, 1 C. colliculosa, 1 C. dubliniensis, 2 Trichosporum asahii, 1 T. mucoide, 1 Trichosporum spp., 1 Kloakera apis, 2 Pichia ohmeri, and 2 Rhodotorula glutinis) isolated from blood culture between October 2002 and May 2005 were assayed. Voriconazole has shown good in vitro activity. The rate of voriconazole-susceptible (MIC or =4 mg/l) to voriconazole (1.38%) by the reference method. The colorimetric method identified the voriconazole-resistant C. tropicalis strain, and classified the C. glabrata as susceptible-dose dependent. The colorimetric method is a potential alternative method for testing the susceptibility of yeast in a clinical laboratory and identifies the susceptible strains (100% agreement) very well. Nevertheless, further studies including more voriconazole-resistant strains are required to determine the ability of the method to identify resistance, which is the goal of susceptibility tests.

  6. A novel real-time PCR-based method for the detection of Listeria monocytogenes in food.

    Science.gov (United States)

    Oravcová, K; Kuchta, T; Kaclíková, E

    2007-11-01

    A new real-time PCR-based method was developed for the detection of Listeria monocytogenes in food. A two-step enrichment involving a 24-h incubation in half-Fraser broth followed by a 6-h subculture in Fraser broth was used, followed by cell lysis and real-time PCR with primers and a TaqMan probe previously developed in our laboratory. When the method was evaluated with 144 naturally contaminated food samples, 44 were detected as positive by the PCR-based method and 42 by the standard method EN ISO 11290-1. With 61 food samples artificially contaminated at a level of 10(0) CFU per 25 g, 61 and 58 positive samples were detected by the respective methods. The developed real-time PCR-based method facilitated the detection of L. monocytogenes in food on the next day after the sample reception, with a reduction of false-positive results because of dead bacterial cells and false-negative results because of PCR inhibitors. The method can be used for L. monocytogenes detection in food as a faster alternative to current methods.

  7. A fluorescence anisotropy method for measuring protein concentration in complex cell culture media.

    Science.gov (United States)

    Groza, Radu Constantin; Calvet, Amandine; Ryder, Alan G

    2014-04-22

    The rapid, quantitative analysis of the complex cell culture media used in biopharmaceutical manufacturing is of critical importance. Requirements for cell culture media composition profiling, or changes in specific analyte concentrations (e.g. amino acids in the media or product protein in the bioprocess broth) often necessitate the use of complicated analytical methods and extensive sample handling. Rapid spectroscopic methods like multi-dimensional fluorescence (MDF) spectroscopy have been successfully applied for the routine determination of compositional changes in cell culture media and bioprocess broths. Quantifying macromolecules in cell culture media is a specific challenge as there is a need to implement measurements rapidly on the prepared media. However, the use of standard fluorescence spectroscopy is complicated by the emission overlap from many media components. Here, we demonstrate how combining anisotropy measurements with standard total synchronous fluorescence spectroscopy (TSFS) provides a rapid, accurate quantitation method for cell culture media. Anisotropy provides emission resolution between large and small fluorophores while TSFS provides a robust measurement space. Model cell culture media was prepared using yeastolate (2.5 mg mL(-1)) spiked with bovine serum albumin (0 to 5 mg mL(-1)). Using this method, protein emission is clearly discriminated from background yeastolate emission, allowing for accurate bovine serum albumin (BSA) quantification over a 0.1 to 4.0 mg mL(-1) range with a limit of detection (LOD) of 13.8 μg mL(-1). Copyright © 2014. Published by Elsevier B.V.

  8. Detection and isolation of low levels of E. coli O157:H7 in cilantro by real-time PCR, immunomagnetic separation, and cultural methods with and without an acid treatment.

    Science.gov (United States)

    Yoshitomi, Ken J; Jinneman, Karen C; Zapata, Ruben; Weagant, Stephen D; Fedio, Willis M

    2012-08-01

    Leafy greens such as cilantro, contaminated with Escherichia coli O157:H7, have been implicated in cases of human illnesses. High levels of microflora in fresh cilantro make recovery of low numbers of E. coli O157:H7 difficult. To improve upon current methods, immunomagnetic separation (IMS) techniques in combination with real-time PCR (RTiPCR) and selective enrichment protocols were examined. Rinsates were prepared from cilantro samples inoculated with low (~0.02 CFU/g) and slightly higher (~0.05 CFU/g) levels of E. coli O157:H7. Rinsate portions were enriched in modified buffered peptone water with pyruvate (mBPWp) for 5 h at 37 °C. After 5 h, selective agents were added to samples and further incubated at 42 °C overnight. Detection and recovery were attempted at 5 and 24 h with and without IMS. IMS beads were screened by RTiPCR for simultaneous detection of stx1, stx2, and uidA SNP. Additionally, broth cultures and IMS beads were streaked onto selective agar plates (Rainbow(®) agar, R&F(®) E. coli O157 Chromogenic medium, TC-SMAC and CHROMagar™ 0157) for isolation of E. coli O157:H7. Both broth cultures and IMS beads were also acid treated in Trypticase Soy Broth pH 2 prior to plating to selective media to improve upon cultural recovery. Although E. coli O157 strains were detected in most samples by PCR after 5 h enrichment, cultural recovery was poor. However, after 24 h enrichment, both PCR and cultural recovery were improved. Acidification of the broths and the IMS beads prior to plating greatly improved recovery from 24 h enrichment broths by suppressing the growth of competing microorganisms. Detection and recovery of Escherichia coli O157:H7 in fresh produce matrices (e.g., cilantro) can be complicated by high background microflora present in these foods. Rapid detection by molecular methods combined with effective enrichment and isolation procedures such as using immunomagnetic separation (IMS) techniques can quickly identify potential hazards to

  9. Investigations of kanuka and manuka essential oils for in vitro treatment of disease and cellular inflammation caused by infectious microorganisms.

    Science.gov (United States)

    Chen, Chien-Chia; Yan, Sui-Hing; Yen, Muh-Yong; Wu, Pei-Fang; Liao, Wei-Ting; Huang, Tsi-Shu; Wen, Zhi-Hong; David Wang, Hui-Min

    2016-02-01

    Diseases caused by infectious and inflammatory microorganisms are among the most common and most severe nosocomial diseases worldwide. Therefore, developing effective agents for treating these illnesses is critical. In this study, essential oils from two tea tree species, kanuka (Kunzea ericoides) and manuka (Leptospermum scoparium), were evaluated for use in treating diseases and inflammation caused by microorganism infection. Isolates of clinically common bacteria and fungi were obtained from American Type Culture Collection and from Kaohsiung Veterans General Hospital. Minimum inhibitory concentrations for Trichosporon mucoides, Malassezia furfur, Candida albicans, and Candida tropicalis were determined by the broth microdilution method with Sabouraud dextrose broth. The antibacterial susceptibility of Staphylococcus aureus, Streptococcus sobrinus, Streptococcus mutans, and Escherichia coli were determined by the broth microdilution method. A human acute monocytic leukemia cell line (THP-1) was cultured to test the effects of the essential oils on the release of the two inflammatory cytokines, tumor necrosis factor-α and interleukin-4. Multiple analyses of microorganism growth confirmed that both essential oils significantly inhibited four fungi and the four bacteria. The potent fungicidal properties of the oils were confirmed by minimum inhibitory concentrations ranging from 0.78% to 3.13%. The oils also showed excellent bactericidal qualities with 100% inhibition of the examined bacteria. In THP-1 cells, both oils lowered tumor necrosis factor-α released after lipopolysaccharide stimulation. Finally, the antimicrobial and anti-inflammatory effects of the oils were obtained without adversely affecting the immune system. These results indicate that the potent antimicroorganism and anti-inflammation properties of kanuka and manuka essential oils make them strong candidates for use in treating infections and immune-related disease. The data confirm the potential

  10. Effects of in vitro culture methods on morphological development and infectivity of Strongyloides venezuelensis filariform larvae

    Science.gov (United States)

    Islam, M. Khyrul; Matsuda, Kiku; Kim, Jin-Ho

    1999-01-01

    The effects of in vitro culture methods on morphological development and infectivity of Strongyloides venezuelensis filariform larvae (L3) to rats were investigated. A significantly higher body length was observed in L3 from filter paper culture (597.3 ± 32.2 µm) than those in fecal (509.9 ± 35.0 µm) and nutrient broth culture (503.3 ± 31.0 µm) (P<0.05). Larval infectivity was assessed by exposing rats to 1,000 L3 from each culture and worms were recovered from the lungs and small intestines. Recovery rate of these worms did not show any significant difference. A significantly greater body length of adults was recorded in those corresponding to the L3 harvested from filter paper (2,777.5 ± 204.4 µm) and nutrient broth culture (2,732.5 ± 169.8 µm) than those corresponding to the L3 obtained from fecal culture (2,600.5 ± 172.4 µm) (P<0.05). Although worm fecundity and EPG counts differed among culture methods but worm burdens and course of infection did not. These findings suggest that the methods of cultures have a significant effect on the morphological development of the larvae to the L3 stage, but do not influence the infectivity to rats. PMID:10188378

  11. GeneQuence" Salmonella assay. Performance Tested Method 030201.

    Science.gov (United States)

    Alles, Susan; Mozola, Mark

    2009-01-01

    A study was conducted to validate the GeneQuence Salmonella DNA hybridization assay, Performance Tested Method 030201, for detection of Salmonella spp. in peanut butter. The study was organized by the AOAC Research Institute under its Emergency Response Validation program. Peanut butter samples inoculated with S. Typhimurium were prepared by an independent laboratory and shipped to study participants for testing. The set of blind-coded test samples consisted of five uninoculated controls, 20 portions inoculated with S. Typhimurium at a low level [determined by most probable number (MPN) analysis to contain 1.1 CFU/25 g portion], and 20 portions inoculated with S. Typhimurium at a higher level (11 CFU/25 g portion by MPN analysis). Samples were tested in parallel by the GeneQuence method and by the U.S. Food and Drug Administration's Bacteriological Analytical Manual reference culture procedure. All five control samples were negative by both methods. For the low-level samples, the same two samples were positive by both the GeneQuence and reference methods. For the high-level samples, the same 19 samples were positive by both methods. All positive GeneQuence assays were confirmed by plating from associated broth cultures. Agreement between the GeneQuence and reference methods was 100%. Sensitivity and specificity of the GeneQuence method were both 100%. Because neither the low- nor the high-level samples yielded the desired fractional positive results (5-15 positives out of 20 samples), a second trial was conducted. Samples in the second trial contained 0.1 and 0.5 CFU/25 g portion for the low and high levels, respectively. All five control samples were negative by both methods. For the low-level samples, the same two samples were positive by both the GeneQuence and reference methods. For the high-level samples, the same three samples were positive by both methods. All positive GeneQuence assays were confirmed by plating from associated broth cultures. Sensitivity

  12. Evaluation of abbreviated enzyme immunoassay method for detection of Salmonella in low-moisture foods.

    Science.gov (United States)

    Flowers, R S; Klatt, M J; Robison, B J; Mattingly, J A

    1988-01-01

    A modified enzyme immunoassay method (EIA) utilizing an 18 h pre-enrichment, a 6-8 h selective enrichment, and a 14 h M-broth post-enrichment is compared to the standard culture method (AOAC/BAM) on selected low-moisture foods. Tested samples included 238 inoculated, 30 naturally contaminated, and 30 uninoculated foods. By EIA, 235 samples were positive (optical densities greater than 0.2 at 405 nm), 233 of which were confirmed culturally. By the culture methods, 221 samples were positive. The EIA method was more productive in detecting salmonellae in inoculated samples of dry cheese powder, chocolate, and nonfat dry milk, whereas the culture method gave better recovery from naturally contaminated meat and bone meal. The modified EIA could be completed in 40 h and required no centrifugation.

  13. Genetic bioaugmentation as an effective method for in situ bioremediation

    Science.gov (United States)

    Ikuma, Kaoru; Gunsch, Claudia K.

    2012-01-01

    Genetic bioaugmentation is an in situ bioremediation method that stimulates horizontal transfer of catabolic plasmids between exogenous donor cells and indigenous bacteria to increase the biodegradation potential of contaminants. A critical outcome of genetic bioaugmentation is the expression of an active catabolic phenotype upon plasmid conjugation. Using a pWW0-derivative TOL plasmid, we showed that certain genetic characteristics of the recipient bacteria, including genomic guanine-cytosine (G + C) content and phylogeny, may limit the expression of the transferred catabolic pathway. However, such genetic limitations observed in transconjugants could be overcome by the presence of an additional carbon source. Glucose and Luria-Bertani broth were shown to enhance the toluene degradation rates of transconjugants; these enhancement effects were dependent on transconjugant genomic G + C contents. Based on these observations, thorough genetic characterization of the indigenous microbial community in the contaminated environment of interest may provide a predictive tool for assessing the success of genetic bioaugmentation. PMID:22705839

  14. Conventional methods for the detection and isolation of Salmonella enteritidis.

    Science.gov (United States)

    van der Zee, H

    1994-01-01

    Conventional methods for the specific isolation of Salmonella enteritidis are scarce. For pre-enrichment, addition of ammonium-iron (III)-citrate, ferrioxamine E and G or novobiocin in combination with cefsoludin to Buffered Peptone Water (BPW) and of ferrous sulphate to Trypticase Soy Broth seems to favour S. enteritidis isolation. As far as selective media are concerned, the use of semi-solid media, and addition of nitrofurantoin, results in higher isolation rates of the S. enteritidis serovar. Addition of 0.0015% nitrofurantoin to semi-solid DIASALM is so far the only successful combination reported. Addition of 0.0015% nitrofurantoin to solid media, in this case to XLD, is also reported. Use of a semi-solid medium, preferably DIASALM + 0.0015% nitrofurantoin, in addition to the selective media routinely used is recommended.

  15. Simple method for correct enumeration of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Haaber, J.; Cohn, M. T.; Petersen, A.

    2016-01-01

    culture. When grown in such liquid cultures, the human pathogen Staphylococcus aureus is characterized by its aggregation of single cells into clusters of variable size. Here, we show that aggregation during growth in the laboratory standard medium tryptic soy broth (TSB) is common among clinical...... and laboratory S. aureus isolates and that aggregation may introduce significant bias when applying standard enumeration methods on S. aureus growing in laboratory batch cultures. We provide a simple and efficient sonication procedure, which can be applied prior to optical density measurements to give...... an accurate estimate of cellular numbers in liquid cultures of S. aureus regardless of the aggregation level of the given strain. We further show that the sonication procedure is applicable for accurate determination of cell numbers using agar plate counting of aggregating strains....

  16. A combined enrichment/polymerase chain reaction based method for the routine screening of Streptococcus agalactiae in pregnant women

    Directory of Open Access Journals (Sweden)

    F.M. Munari

    2012-03-01

    Full Text Available Group B Streptococcus (GBS is the most common cause of life-threatening infection in neonates. Guidelines from CDC recommend universal screening of pregnant women for rectovaginal GBS colonization. The objective of this study was to compare the performance of a combined enrichment/PCR based method targeting the atr gene in relation to culture using enrichment with selective broth medium (standard method to identify the presence of GBS in pregnant women. Rectovaginal GBS samples from women at ≥36 weeks of pregnancy were obtained with a swab and analyzed by the two methods. A total of 89 samples were evaluated. The prevalence of positive results for GBS detection was considerable higher when assessed by the combined enrichment/PCR method than with the standard method (35.9% versus 22.5%, respectively. The results demonstrated that the use of selective enrichment broth followed by PCR targeting the atr gene is a highly sensitive, specific and accurate test for GBS screening in pregnant women, allowing the detection of the bacteria even in lightly colonized patients. This PCR methodology may provide a useful diagnostic tool for GBS detection and contributes for a more accurate and effective intrapartum antibiotic and lower newborn mortality and morbidity.

  17. A new versatile microarray-based method for high throughput screening of carbohydrate-active enzymes.

    Science.gov (United States)

    Vidal-Melgosa, Silvia; Pedersen, Henriette L; Schückel, Julia; Arnal, Grégory; Dumon, Claire; Amby, Daniel B; Monrad, Rune Nygaard; Westereng, Bjørge; Willats, William G T

    2015-04-03

    Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing together with associated bioinformatics tools have identified vast numbers of putative carbohydrate-degrading and -modifying enzymes including glycoside hydrolases and lytic polysaccharide monooxygenases. However, there is a paucity of methods for rapidly screening the activities of these enzymes. By combining the multiplexing capacity of carbohydrate microarrays with the specificity of molecular probes, we have developed a sensitive, high throughput, and versatile semiquantitative enzyme screening technique that requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme mixtures, and crude culture broths against single substrates, substrate mixtures, and biomass samples. Moreover, we show that the technique can be used to analyze both endo-acting and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. We demonstrate the potential of the technique by identifying the substrate specificities of purified uncharacterized enzymes and by screening enzyme activities from fungal culture broths. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. A New Versatile Microarray-based Method for High Throughput Screening of Carbohydrate-active Enzymes*

    Science.gov (United States)

    Vidal-Melgosa, Silvia; Pedersen, Henriette L.; Schückel, Julia; Arnal, Grégory; Dumon, Claire; Amby, Daniel B.; Monrad, Rune Nygaard; Westereng, Bjørge; Willats, William G. T.

    2015-01-01

    Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing together with associated bioinformatics tools have identified vast numbers of putative carbohydrate-degrading and -modifying enzymes including glycoside hydrolases and lytic polysaccharide monooxygenases. However, there is a paucity of methods for rapidly screening the activities of these enzymes. By combining the multiplexing capacity of carbohydrate microarrays with the specificity of molecular probes, we have developed a sensitive, high throughput, and versatile semiquantitative enzyme screening technique that requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme mixtures, and crude culture broths against single substrates, substrate mixtures, and biomass samples. Moreover, we show that the technique can be used to analyze both endo-acting and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. We demonstrate the potential of the technique by identifying the substrate specificities of purified uncharacterized enzymes and by screening enzyme activities from fungal culture broths. PMID:25657012

  19. EFICIÊNCIA DO ENRIQUECIMENTO EM DUPLO ESTÁGIO REALIZADO NOS CALDOS UVM E FRASER E DESEMPENHO DOS ÁGARES LPM E LSAB-CAN PARA A DETECÇÃO DE Listeria spp. EM CARNE DE FRANGO NATURALMENTE CONTAMINADA EFFICIENCY OF DOUBLE STEPS ENRICHMENT IN THE UVM AND FRASER BROTHES AND PERFORMANCE OF LPM AND LSAB-CAN AGARS TO DETECTION OF Listeria spp. IN NATURALLY CONTAMINATED CHICKEN MEAT

    Directory of Open Access Journals (Sweden)

    Albenones José de Mesquita

    2007-09-01

    Full Text Available

    No presente trabalho, avaliou-se o desempenho de dois caldos e dois ágares seletivos para o isolamento de Listeria a partir de carne de frango naturalmente contaminada, adquirida no comércio varejista de Goiânia - GO, no período de janeiro a junho de 1992. A metodologia de isolamento e identificação de Listeria adotada envolveu a utilização de enriquecimento seletivo em estágio duplo nos caldos "University of Vermont" e Fraser e plaqueamento no ágar cloreto de lítio-feniletanol-moxalactam e no ágar base seletivo para Listeria, suplementado com cicloheximide, acriflavina e ácido nalidíxico. Verificou-se o desempenho dos caldos e enriquecimento para Listeria (caldos UVM e Fraser, associados à passagem da cultura por uma solução de hidróxido de potássio a 0,25%, constatando-se que os mesmos se equivaleram estatisticamente (Z= -1,7393<1,96. Por outro lado, o ágar LPM apresentou destacada superioridade frente ao ágar LSAB-CAN em relação ao total de amostras analisadas (Z= 7, 368>Z0,975. O tratamento da cultura com a solução de hidróxido de potássio a 0,25% mostrou ligeira inibição, contribuindo para redução no número de amostras positivas detectadas.

    PALAVRAS-CHAVE: Listeria; caldo de enriquecimento; carne de frango.

    It was determined the performance of two selective broths and two agars to isolate Listeria from chicken meat naturally contaminated, acquired in the supermarkets of Goiânia-Goiás, between January and June 1992. Methodology of isolation involved the utilization of two-stage selective enrichment in the University of Vermont and Fraser broths and plating in lithium chloride-phenyletanol-moxalactam agar and the Listeria selective agar base supplemented with cicloheximide

  20. Five New Guaiane Sesquiterpenes from the Endophytic Fungus Xylaria sp. YM 311647 of Azadirachta indica.

    Science.gov (United States)

    Huang, Rong; Xie, Xiao-Song; Fang, Xiao-Wei; Ma, Kai-Xia; Wu, Shao-Hua

    2015-08-01

    Five new guaiane sesquiterpenes, 1-5, were isolated from the culture broth of the endophytic fungus Xylaria sp. YM 311647, isolated from Azadirachta indica A. Juss. The structures of these compounds were elucidated on the basis of spectroscopic analyses, and their inhibitory activities against five pathogenic fungi were evaluated. All guaiane sesquiterpenes showed moderate or weak antifungal activities in a broth microdilution assay. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

  1. Introduction and comparison of measurement methods of antifungal properties of lactic acid bacteria in cheese

    Directory of Open Access Journals (Sweden)

    H Sedaghat

    2014-02-01

    Full Text Available Various laboratory methods have been developed to evaluate the effectiveness of anti-mould effect of lactic acid bacteria. However, most of these investigations have been conducted in culture medium. Due to the occurrence of complex interaction between food components and antimicrobial substances produced by lactic acid bacteria, the result achieved from these studies may be different from those seen in food model. In various studies growth inhibition of molds on the surface of foods are considered as antifungal activity. Consequently, introduction and comparison of efficient methods for evaluation of anti-mould effect of lactic acid bacteria would be helpful. In this study, antifungal activity of lactic acid bacteria inoculated in cheese was estimated using Microdilution method. Pieces of cheese samples were overlaid with molds and the antifungal effect of this bacteria was studied against Aspergillus flavus and Aspergillus parasiticus. All three methods showed the effectiveness of lactic bacteria on mold inhibition. Comparison of the results showed that there was significant positive correlation between antifungal overlay assay and direct growth of mold on cheese, since this two test showed antifungal effect in the same way including interaction between bacteria and mold and also producing antifungal compound.

  2. In vitro susceptibilities of recent field isolates of Mycoplasma hyopneumoniae and Mycoplasma hyosynoviae to valnemulin (Econor), tiamulin and enrofloxacin and the in vitro development of resistance to certain antimicrobial agents in Mycoplasma hyopneumoniae.

    Science.gov (United States)

    Hannan, P C; Windsor, H M; Ripley, P H

    1997-01-01

    The in vitro activities of valnemulin (Econor) and two other antimicrobial agents were determined against recent field strains of Mycoplasma hyopneumoniae and Mycoplasma hyosynoviae using a broth microdilution method. Valnemulin showed exceptional activity against M hyopneumoniae (MIC90 0.0005 microgram ml-1) and M hyosynoviae (MIC range 0.0001 microgram ml-1 to 0.00025 microgram ml-1) field strains. Tiamulin was 100-fold less active (MIC90 0.05 microgram ml-1) and enrofloxacin 20-fold less active (MIC90 0.01 microgram ml-1) than valnemulin against M hyopneumoniae field isolates and 20-fold to 25-fold less active (MIC range 0.0025 microgram ml-1 to 0.005 microgram ml-1) and 400-fold to 500-fold less active (MIC range 0.05 microgram ml-1 to 0.1 microgram ml-1) respectively against M hyosynoviae field isolates. No significant resistance developed to valnemulin or tiamulin in the type strain of M hyopneumoniae (strain J) or in a recent field isolate (MEVT G23) exposed to 10 in vitro passages in broths containing these antibiotics. Only slight resistance to oxytetracycline was observed. High resistance to tylosin developed in both M hyopneumoniae strains within five to seven in vitro passages in tylosin-containing broth. Providing that similar results are obtained in vivo under field conditions, valnemulin may well prove to be effective in the treatment of enzootic pneumonia and acute polyarthritis in pigs.

  3. Neem (Azadirachta indica A. Juss Oil: A Natural Preservative to Control Meat Spoilage

    Directory of Open Access Journals (Sweden)

    Paola Del Serrone

    2015-01-01

    Full Text Available Plant-derived extracts (PDEs are a source of biologically-active substances having antimicrobial properties. The aim of this study was to evaluate the potential of neem oil (NO as a preservative of fresh retail meat. The antibacterial activity of NO against Carnobacterium maltaromaticum, Brochothrix thermosphacta, Escherichia coli, Pseudomonas fluorescens, Lactobacillus curvatus and L. sakei was assessed in a broth model system. The bacterial growth inhibition zone (mm ranged from 18.83 ± 1.18 to 30.00 ± 1.00, as was found by a disc diffusion test with 100 µL NO. The bacterial percent growth reduction ranged from 30.81 ± 2.08 to 99.70 ± 1.53 in the broth microdilution method at different NO concentrations (1:10 to 1:100,000. Viable bacterial cells were detected in experimentally-contaminated meat up to the second day after NO treatment (100 µL NO per 10 g meat, except for C. maltaromaticum, which was detected up to the sixth day by PCR and nested PCR with propidium monoazide (PMA™ dye. In comparison to the previously published results, C. maltaromaticum, E. coli, L. curvatus and L. sakei appeared more susceptible to NO compared to neem cake extract (NCE by using a broth model system.

  4. Ultrasonication-Induced Synthesis and Antimicrobial Evaluation of Some Multifluorinated Pyrazolone Derivatives

    Directory of Open Access Journals (Sweden)

    Anil Gadhave

    2013-01-01

    Full Text Available A series of novel fluorine containing pyrazole-pyrazolone (4a–j and chromone-pyrazolone (5a–i was synthesized from multifluorinated pyrazolone by the Knoevenagel condensation reaction. All compounds were synthesized by conventional heating as well as ultrasound irradiation technique. It was found that ultrasonication method was more efficient than conventional heating method. The newly synthesized compounds were subjected for in vitro antimicrobial screening against four bacterial pathogens, namely, Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, and Pseudomonas aeruginosa and three fungal pathogens Candida albicans, Aspergillus niger, and Aspergillus clavatus, using broth microdilution (MIC method (CLSI guidelines. Among them, some compounds exhibited promising antibacterial activity against the tested strains. All synthesized compounds were characterized by IR, 1H-NMR, mass, and elemental analysis.

  5. The ability of selected plant essential oils to enhance the action of recommended antibiotics against pathogenic wound bacteria.

    Science.gov (United States)

    Sienkiewicz, Monika; Łysakowska, Monika; Kowalczyk, Edward; Szymańska, Grażyna; Kochan, Ewa; Krukowska, Jolanta; Olszewski, Jurek; Zielińska-Bliźniewska, Hanna

    2017-03-01

    The aim of this work was to characterize the ability of essential oils to support antibiotics against pathogenic bacteria in wounds. Gram-positive and Gram-negative bacteria obtained from wound infections were identified according to standard microbiological methods. Essential oils were analysed by GC-FID-MS. The susceptibility of bacteria to antibiotics, essential oils and their combination was assessed using the disc-diffusion method. The Minimal Inhibitory Concentration and Minimum Bactericidal Concentration of the essential oils were established by the micro-dilution broth method. Although cinnamon, clove, thyme and lavender essential oils were found to have the greatest antibacterial activity when used alone, the greatest additive and synergistic effects against pathogenic wound bacteria in combination with recommended antibiotics were demonstrated by basil, clary sage and rosemary oils. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  6. Evaluation of VIDAS Salmonella (SLM) immunoassay method with Rappaport-Vassiliadis (RV) medium for detection of Salmonella in foods: collaborative study.

    Science.gov (United States)

    McMahon, Wendy A; Schultz, Ann M; Johnson, Ronald L

    2004-01-01

    A collaborative study was conducted to compare the VIDAS Salmonella (SLM) with Rappaport-Vassiliadis (RV) method for detection of Salmonella in foods to the current standard method presented in the U.S. Food and Drug Administration's Bacteriological Analytical Manual (BAM) and the culture method presented in AOAC's Official Methods of Analysis. The VIDAS SLM with RV method uses tetrathionate broth in combination with RV medium in place of selenite cystine broth for selective enrichment, thereby eliminating the hazardous waste issue for laboratories. Twenty five laboratories participated in the evaluation, each testing one or more of 8 test products: nonfat dry milk, dried egg, soy flour, lactic casein, milk chocolate, raw ground pork, raw ground turkey, and raw peeled shrimp. Results of the study showed no significant differences in the numbers of confirmed positive samples with the VIDAS SLM with RV procedure and the BAM/AOAC culture procedure. The VIDAS SLM with RV method was effective for rapid detection of Salmonella in foods. It is recommended that AOAC INTERNATIONAL modify the VIDAS Salmonella SLM procedure to include the RV method.

  7. Evaluation and comparison of rapid methods for the detection of Salmonella in naturally contaminated pine nuts using different pre enrichment media.

    Science.gov (United States)

    Wang, Hua; Gill, Vikas S; Cheng, Chorng-Ming; Gonzalez-Escalona, Narjol; Irvin, Kari A; Zheng, Jie; Bell, Rebecca L; Jacobson, Andrew P; Hammack, Thomas S

    2015-04-01

    Foodborne outbreaks, involving pine nuts and peanut butter, illustrate the need to rapidly detect Salmonella in low moisture foods. However, the current Bacteriological Analytical Manual (BAM) culture method for Salmonella, using lactose broth (LB) as a pre enrichment medium, has not reliably supported real-time quantitative PCR (qPCR) assays for certain foods. We evaluated two qPCR assays in LB and four other pre enrichment media: buffered peptone water (BPW), modified BPW (mBPW), Universal Pre enrichment broth (UPB), and BAX(®) MP media to detect Salmonella in naturally-contaminated pine nuts (2011 outbreak). A four-way comparison among culture method, Pathatrix(®) Auto, VIDAS(®) Easy SLM, and qPCR was conducted. Automated DNA extraction techniques were compared with manual extraction methods (boiling or InstaGene™). There were no significant differences (P > 0.05) among the five pre enrichment media for pine nuts using the culture method. While both qPCR assays produced significantly (P ≤ 0.05) higher false negatives in 24 h pre enriched LB than in the other four media, they were as sensitive as the culture method in BPW, mBPW, UPB, and BAX media. The VIDAS Easy and qPCR were equivalent; Pathatrix was the least effective method. The Automatic PrepSEQ™ DNA extraction, using 1000 μL of pre enrichment, was as effective as manual extraction methods. Published by Elsevier Ltd.

  8. [Comparative study of 4 methods for isolating Salmonella from surface waters].

    Science.gov (United States)

    Anselmo, R J; Barrios, H; Viora, S; Lorent, B; Eiguer, T; Caffer, M I; Fliess, E

    1989-01-01

    The study presented here is the first stage of a project designed to determine the presence of Salmonella serotypes in Lujan river waters, which flow beside the urban area of the homonymous city, in the province of Buenos Aires. It consisted in a comparative study of four methods for Salmonellae detection in 200 samples: Tetrathionate-brilliant green; mannitol-selenite; Rappaport 25 and modified Rappaport-Vassiliadis broth, each of them with and without pre-enrichment in buffered peptone water. The submerged gauze technique was applied to the sampling in three different spots of the river: at the town center, two km water above, and two down-stream from the city. Best results were obtained when modified Rappaport-Vassiliadis enrichment broth and brilliant green agar with 0.25% of sodium deoxycholate were used, after pre-enrichment of the samples in buffered peptone water. Salmonella were isolated from 46% of the samples studied, and 16 serotypes were identified: S. Typhimurium, S. Enteritidis, S. Infantis, S. Mbandaka, S. Israel and S. Subspecies IV 18 z36: z38:-, among them.

  9. Comparison of screening methods to identify methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Kampf, G; Weist, K; Swidsinski, S; Kegel, M; Rüden, H

    1997-04-01

    Screening methods to identify methicillin-resistant Staphylococcus aureus (MRSA) were compared using 96 isolates representing 17 distinct clones. The sensitivity of four commercial agglutination tests was determined in comparison to the tube coagulation test, and the results related to the presence of the coagulase gene. The broth screening test, agar dilution test and disc diffusion test were carried out, and the results related to the presence of the mecA gene. Mannitol salt agar and Iso-Sensitest agar with varying salt supplements were used. All agglutination tests had high rates of detection of Staphylococcus aureus (95.8-99.0%). Resistance in mecA gene-positive Staphylococcus aureus isolates was correctly detected by the oxacillin broth test, the agar dilution test and the disc diffusion test on mannitol salt agar, whereas on Iso-Sensitest agar detection rates were lower (between 68.5% and 94.4%, depending on the salt supplement). Incubation of the Iso-Sensitest plates for 48 hours significantly improved the rate of detection of resistance, but increased the major error rate up to 71.4%. MecA gene-positive Staphylococcus aureus isolates not detected by the disc diffusion test on Iso-Sensitest agar had significantly lower oxacillin minimal inhibitory concentration values and were significantly less resistant to a variety of antibiotics. Thus, mannitol salt agar might be a suitable medium for use in the disc diffusion and agar dilution test to detect resistance to oxacillin in Staphylococcus aureus.

  10. Synergistic effects of Salvia officinalis L. essential oils and antibiotics against methicillin-resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Milenković Marina T.

    2015-01-01

    Full Text Available Infections caused by methicillin-resistant Staphylococcus aureus (MRSA due to the acquisition of resistance to current antimicrobials pose a serious challenge for therapy, and new measures to treat and prevent this infectious pathogen are of crucial importance. Plant essential oils (EOs and their constituents are promising agents with antimicrobial properties. The aim of this study was to evaluate the antistaphylococcal effect of essential oils from Salvia officinalis using the broth-microdilution method. Essential oils of S. officinalis were isolated from the same individual, but at different life stages - young and old leaves. The effects of combinations of sub-inhibitory concentrations of oil and different antibiotics were evaluated by the checkerboard method. The results, expressed as the fractional inhibitory concentration (FIC and index (FICI, indicate that the essential oil isolated from young leaves potentiated the inhibitory effect of antibiotics against tested MRSA strains. [Projekat Ministarstva nauke Republike Srbije, br. 173021

  11. Antimicrobial activity of the three commercial drug’s essential oils: Chamomillae flos, Calendulae flos and Millefolii herba

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    Stojanović-Radić, Z.

    2012-12-01

    Full Text Available Commercial herbal drugs of the three plants belonging to family Asteraceae were used for the extraction of the essential oils (hydrodistillation method. Since various factors during the processing of the plant material can affect several characteristics of essential oils such as yield, chemical composition and, thus, biological activities of essential oils, comparison of the antimicrobial activity of the herein isolated oils was done with avaiable literature sources dealing with this subject. In order to evaluate antimicrobial potential of the isolated essential oils, a broth microdilution method was employed. The results pointed to very high activity of the tested oils, in all cases much stronger in comparison to the previous results. As a conclusion, the adverse effects of plant material processing did not affect its antimicrobial potential, while the obtained high antimicrobial activity can be explained by sinergistic action of the herein used solvent with essential oils.

  12. Cave Cyanobacteria showing antibacterial activity

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    Vasiliki Lamprinou

    2015-09-01

    Full Text Available Cave Cyanobacteria - thriving in an ‘extreme’ environment with interesting species biodiversity - are supposed to be a potential source of bioactive compounds. Lipid extracts from pure cultures of two recently established Cyanobacteria from Greek caves, Toxopsis calypsus and Phormidium melanochroun, were used for antibacterial screening against human pathogenic bacteria (reference and clinical isolates. Antimicrobial Susceptibility testing for both taxa was carried out using the disc-diffusion (Kirby Bauer method, while preliminary data applying the standard broth microdilution method for the determination of the Minimal Inhibitory Concentration (MIC are given only for T. calypsus. Antibacterial activity was demonstrated against the Gram-positive clinical and reference bacteria, mostly pronounced in enterococci; no activity was observed against the Gram-negative bacteria. The above screening is the first record of antibacterial activity from lipid extracts of cave Cyanobacteria enhancing the importance of cave microbiota and the necessity for cave conservation.

  13. Chemical composition and biological activity of the acetone extract of Ambrosia artemisiifolia L. pollen

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    SLAVICA SOLUJIC

    2008-10-01

    Full Text Available In this study, the chemical components, antimicrobial and genotoxic biological activities of the acetone extract of Ambrosia artemisiifolia L. pollen were examined. Two lactones were identified: ambrosin and artesovin. The antimicrobial activity of the acetone extract of A. artemisiifolia L. pollen was examined on ten different bacterial species using the disc diffusion method and the microdilution method in Mueller-Hinton broth dilution. The minimal inhibitory concentration of the acetone extract of A. artemisiifolia pollen varied between 1.25−6.50 mg mL-1. The genotoxic effect of the acetone extract of A. artemisiifolia pollen on a eukaryotic model system Drosophila melanogaster was investigated using the SLRL test.

  14. Miniaturized Antimicrobial Susceptibility Test by Combining Concentration Gradient Generation and Rapid Cell Culturing

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    Samuel C. Kim

    2015-10-01

    Full Text Available Effective treatment of bacterial infection relies on timely diagnosis and proper prescription of antibiotic drugs. The antimicrobial susceptibility test (AST is one of the most crucial experimental procedures, providing the baseline information for choosing effective antibiotic agents and their dosages. Conventional methods, however, require long incubation times or significant instrumentation costs to obtain test results. We propose a lab-on-a-chip approach to perform AST in a simple, economic, and rapid manner. Our assay platform miniaturizes the standard broth microdilution method on a microfluidic device (20 × 20 mm that generates an antibiotic concentration gradient and delivers antibiotic-containing culture media to eight 30-nL chambers for cell culture. When tested with 20 μL samples of a model bacterial strain (E. coli ATCC 25922 treated with ampicillin or streptomycin, our method allows for the determination of minimum inhibitory concentrations consistent with the microdilution test in three hours, which is almost a factor of ten more rapid than the standard method.

  15. Modification of the BAX System PCR assay for detecting Salmonella in beef, produce, and soy protein isolate. Performance Tested Method 100201.

    Science.gov (United States)

    Peng, Linda X; Wallace, Morgan; Andaloro, Bridget; Fallon, Dawn; Fleck, Lois; Delduco, Dan; Tice, George

    2011-01-01

    The BAX System PCR assay for Salmonella detection in foods was previously validated as AOAC Research Institute (RI) Performance Tested Method (PTM) 100201. New studies were conducted on beef and produce using the same media and protocol currently approved for the BAX System PCR assay for E. coli O157:H7 multiplex (MP). Additionally, soy protein isolate was tested for matrix extension using the U.S. Food and Drug Administration-Bacteriological Analytical Manual (FDA-BAM) enrichment protocols. The studies compared the BAX System method to the U.S. Department of Agriculture culture method for detecting Salmonella in beef and the FDA-BAM culture method for detecting Salmonella in produce and soy protein isolate. Method comparison studies on low-level inoculates showed that the BAX System assay for Salmonella performed as well as or better than the reference method for detecting Salmonella in beef and produce in 8-24 h enrichment when the BAX System E. coli O157:H7 MP media was used, and soy protein isolate in 20 h enrichment with lactose broth followed by 3 h regrowth in brain heart infusion broth. An inclusivity panel of 104 Salmonella strains with diverse serotypes was tested by the BAX System using the proprietary BAX System media and returned all positive results. Ruggedness factors involved in the enrichment phase were also evaluated by testing outside the specified parameters, and none of the factors examined affected the performance of the assay.

  16. Roka Listeria detection method using transcription mediated amplification to detect Listeria species in select foods and surfaces. Performance Tested Method(SM) 011201.

    Science.gov (United States)

    Hua, Yang; Kaplan, Shannon; Reshatoff, Michael; Hu, Ernie; Zukowski, Alexis; Schweis, Franz; Gin, Cristal; Maroni, Brett; Becker, Michael; Wisniewski, Michele

    2012-01-01

    The Roka Listeria Detection Assay was compared to the reference culture methods for nine select foods and three select surfaces. The Roka method used Half-Fraser Broth for enrichment at 35 +/- 2 degrees C for 24-28 h. Comparison of Roka's method to reference methods requires an unpaired approach. Each method had a total of 545 samples inoculated with a Listeria strain. Each food and surface was inoculated with a different strain of Listeria at two different levels per method. For the dairy products (Brie cheese, whole milk, and ice cream), our method was compared to AOAC Official Method(SM) 993.12. For the ready-to-eat meats (deli chicken, cured ham, chicken salad, and hot dogs) and environmental surfaces (sealed concrete, stainless steel, and plastic), these samples were compared to the U.S. Department of Agriculture/Food Safety and Inspection Service-Microbiology Laboratory Guidebook (USDA/FSIS-MLG) method MLG 8.07. Cold-smoked salmon and romaine lettuce were compared to the U.S. Food and Drug Administration/Bacteriological Analytical Manual, Chapter 10 (FDA/BAM) method. Roka's method had 358 positives out of 545 total inoculated samples compared to 332 positive for the reference methods. Overall the probability of detection analysis of the results showed better or equivalent performance compared to the reference methods.

  17. [Detection and Serotyping of Streptococcus pneumoniae Carried in Healthy Adults with a Modified PCR Method].

    Science.gov (United States)

    Ishihara, Yuka; Okamoto, Akira; Ohta, Michio

    2015-05-01

    Detection of Streptococcus pneumoniae colonized in the pharynx of healthy carriers currently relies on conventional culture methods of direct plating with pharyngeal swab specimens. The accurate measurement of the carriage of pneumococci, however, has not been necessarily achieved with these methods due to low density colonization and contamination of numerous oral streptococci that express α-hemolysis. A PCR-based detection method of pneumococci-specific for lytA as well as PCR serotyping of S. pneumoniae was recently developed and their effectiveness was confirmed. We modified the reaction conditions of these methods to improve the detection rate and applied them to the measurement of S. pneumoniae carried in healthy adults. Pharyngeal swab specimens obtained from 110 healthy volunteers over 40 and living in Nagoya were enriched for 5 hours with broth medium supplemented with rabbit serum and the template DNA for PCR was extracted from the mixed enriched culture. Of 110 specimens 36 (32.7%) were lytA-positive, the rate of which was much higher than the results of previous culture-based studies. The DNA template preparations were then used for PCR-based serotyping with primers specific for each of the types included in pneumococcal 23 valent vaccine (PPV23). We found that 28 out of 36 lytA-positive carriers were identified as being positive for the serotypes belonging to PPV23, although serotypes 6A and 6B were indistinguishable with the PCR method. The most frequent serotype was serotype 14, and serotypes 4, 18C, and 6A/B were also frequently identified. Five lytA-positive carriers were previously vaccinated with PPV23, and among them, 4 were positive for serotypes contained in PPV23. We recommend PCR-based identification and serotyping of S. pneumoniae in broth enrichment culture of pharyngeal swab specimens as a reliable method for the surveillance of healthy carriers with low density colonization.

  18. Microdilution in vitro antifungal susceptibility of Exophiala dermatitidis, a systemic opportunist

    NARCIS (Netherlands)

    Badali, H.; de Hoog, G.S.; Sudhadham, M.; Meis, J.F.

    2011-01-01

    The in vitro activities of eight antifungal agents were determined against clinical (n = 63 genotype A, n = 3 genotype B) and environmental (n = 2 genotype A, n = 13 genotype B) strains of Exophiala dermatitidis. The resulting MIC90s for all strains (N = 81) were, in increasing order, as follows:

  19. Microdilution in vitro antifungal susceptibility of Exophiala dermatitidis, a systemic opportunist.

    NARCIS (Netherlands)

    Badali, H.; Hoog, G.S. de; Sudhadham, M.; Meis, J.F.G.M.

    2011-01-01

    The in vitro activities of eight antifungal agents were determined against clinical (n = 63 genotype A, n = 3 genotype B) and environmental (n = 2 genotype A, n = 13 genotype B) strains of Exophiala dermatitidis. The resulting MIC(90)s for all strains (N = 81) were, in increasing order, as follows:

  20. EFFICIENCY OF THE ENRICHMENT BROTHES (LEB1 AND LEB2 AND SELECTIVE AGARS (LPM AND LSAB-CAN TO ISOLATE BACTERIA OF THE GENUS Listeria IN MEAT AND RESIDUAL WATER OF WASHING CARCASS EFICIÊNCIA DOS CALDOS DE ENRIQUECIMENTO (LEB1 E LEB2 E DOS ÁGARES SELETIVOS (LPM E LSAB-CAN NO ISOLAMENTO DE BACTÉRIAS DO GÊNERO Listeria EM CARNE BOVINA E ÁGUA RESIDUÁRIA DE LAVAGEM DE CARCAÇA

    Directory of Open Access Journals (Sweden)

    Albenones José de Mesquita

    2007-09-01

    Full Text Available

    In this paper it was observed the efficiency of enrichment brothes for Listeria (LEB1 and LEB2, associated to the passage of the culture through a 0.25% potassium hidroxide solution, verifying that the secondary enrichment broth (LEB2 and LEB2KOH was better than the primary enrichment broth (LEB1KOH for this purpose. On the other hand, lithium chloride-phenylethanol-moxalactam agar and the selective Listeria agar base, supplemented with cicloheximide, acriflavine and nalidixic acid (LSAIB-CAN showed equivalency, at the statistic point of view (p=0.l442, in relation to the number of positive samples for Listeria spp., although the LSAB-CAN agar had given the greatest number of bacteria isolated from this genus.

    KEY-WORDS: Listeria; enrichment broth; selective agar.

    No presente trabalho verificou-se a eficiência dos caldos de enriquecimento para Listeria (LEB1 e LEB 2 associados à passagem da cultura por uma solução de hidróxido de potássio a 0,25%, constatando-se que o caldo de enriquecimento secundário (LEB2 e LEB2KOH foi superior ao caldo de enriquecimento primário (LEB1KOH. Por outro lado, o ágar cloreto de lítio-feniletanol-moxalactam (LPM e o ágar base seletivo para Listeria, suplementado com cicloheximida, acriflavina e ácido nalidíxico (LSAB-CAN equivaleram-se estatisticamente (p= 0,l442 em relação ao número de amostras positivas para Listeria, embora o ágar LSAB-CAN tenha proporcionado um maior número de isolamentos da bactéria.

    PALAVRAS-CHAVE: Caldo de enriquecimento; ágar seletivo; Listeria.

  1. Influence of milk product type and its initial contamination on the efficiency of different methods for detection of Salmonella Enteritidis, Listeria monocytogenes and Escherichia coli O157:H7

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    Boris Antunović

    2018-01-01

    Full Text Available This paper investigates differences in efficacy of isolating pathogenic bacteria Salmonella Enteritidis, Listeria monocytogenes and Escherichia coli O157:H7 between conventional cultivation (ISO method and immunomagnetic separation (IMS method related to the types of dairy products and initial numbers of bacteria. Different milk products (dairy pudding- vanilla or chocolate; a mixture of yoghurt and pudding; solid, liquid and fruit yoghurt; AB culture - with or without fruit; cheese spread were intentionally contaminated with different numbers (≈10 and ≈30 of live cells of the observed bacteria per mL. The obtained results showed that the classical ISO procedure still represents an equally adequate method for the detection of S. Enteritidis and L. monocytogenes in dairy products as well as the IMS method. However, the ISO method was found to be inefficient for determination of E. coli O157:H7 when the initial contamination was low (≈10 live cells per mL. In such cases, even the IMS method appeared to be inefficient when used for fermented dairy product analysis. Fermented dairy products in contrast to the non-fermented ones, still represent a challenge for the development of routine detection methods, especially for S. Enteritidis, whilst the detection of L. monocytogenes and E. coli O157:H7 has improved by introducing the IMS method. The largest difference in the ability to detect bacteria in dairy product samples with reference to the initial number of bacteria by both methods was in the detection of E. coli O157:H7. The choice of broth (non-selective fluid broth vs. selective fluid broth did not matter in the in the detection of S. Enteritidis and L. monocytogenes by applying the IMS procedure. However, for the detection of E. coli O157:H7 the application of modified tripton-soya broth with novobiocin (mTSB+Nb has proved to be superior when compared to using the buffered peptone water (BPW. The presented results may be of importance as

  2. Effect of Manganese in Test Media on In Vitro Susceptibility of Enterobacteriaceae and Acinetobacter baumannii to Tigecycline.

    NARCIS (Netherlands)

    Veenemans, J.; Mouton, J.W.; Kluytmans, J.A.; Donnely, R.; Verhulst, C.; Keulen, P.H. van

    2012-01-01

    We assessed the effect of increasing manganese concentrations in test media (0.001 to 1,024 mg/liter) on MICs of tigecycline. For both broth microdilution (BMD) and Etests, this effect was negligible for physiological concentrations, but MICs increased when concentrations exceeded 8 mg/liter.

  3. Voriconazole MICs are predictive for the outcome of experimental disseminated scedosporiosis.

    Science.gov (United States)

    Martin-Vicente, Adela; Guarro, Josep; González, Gloria M; Lass-Flörl, Cornelia; Lackner, Michaela; Capilla, Javier

    2017-04-01

    Scedosporiosis is associated with a mortality rate of up to 90% in patients suffering from disseminated infections. Recommended first-line treatment is voriconazole, but epidemiological cut-off values and clinical breakpoints have not been determined. To correlate voriconazole treatment response in mice suffering from disseminated scedosporiosis with MIC values determined using CLSI broth microdilution, Etest (bioMérieux) and disc diffusion. Voriconazole MICs for 31 Scedosporium apiospermum strains were determined using CLSI broth microdilution, Etest and disc diffusion. Groups of mice were challenged intravenously with 1 out of 16 S. apiospermum strains (voriconazole CLSI broth microdilution MIC range: 0.125-8.0 mg/L) and treated with 40 mg/kg voriconazole orally by gavage once daily. Efficacy of voriconazole was evaluated by a statistically significant ( P  voriconazole therapy in 92.3% and those challenged with strains with an MIC ≥4 mg/L responded to voriconazole therapy in 33.3%. CLSI broth microdilution and Etest deliver comparable results that enable a prediction of in vivo outcome. Our results suggest that voriconazole is able to reduce fungal burden in the brain of 92.3% of all mice challenged with strains with voriconazole CLSI MICs ≤2 mg/L, while mice challenged with strains with CLSI MICs ≥4 mg/L showed limited response to voriconazole treatment.

  4. Ethnopharmacological versus random plant selection methods for the evaluation of the antimycobacterial activity

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    Danilo R. Oliveira

    2011-05-01

    Full Text Available The municipality of Oriximiná, Brazil, has 33 quilombola communities in remote areas, endowed with wide experience in the use of medicinal plants. An ethnobotanical survey was carried out in five of these communities. A free-listing method directed for the survey of species locally indicated against Tuberculosis and lung problems was also applied. Data were analyzed by quantitative techniques: saliency index and major use agreement. Thirty four informants related 254 ethnospecies. Among these, 43 were surveyed for possible antimycobacterial activity. As a result of those informations, ten species obtained from the ethnodirected approach (ETHNO and eighteen species obtained from the random approach (RANDOM were assayed against Mycobacterium tuberculosis by the microdilution method, using resazurin as an indicator of cell viability. The best results for antimycobacterial activity were obtained of some plants selected by the ethnopharmacological approach (50% ETHNO x 16,7% RANDOM. These results can be even more significant if we consider that the therapeutic success obtained among the quilombola practice is complex, being the use of some plants acting as fortifying agents, depurative, vomitory, purgative and bitter remedy, especially to infectious diseases, of great importance to the communities in the curing or recovering of health as a whole.

  5. Comparative, Collaborative, and On-Site Validation of a TaqMan PCR Method as a Tool for Certified Production of Fresh, Campylobacter-Free Chickens

    DEFF Research Database (Denmark)

    Krause, Michael; Josefsen, Mathilde Hartmann; Lund, Marianne

    2006-01-01

    on naturally contaminated samples (99 shoe covers, 101 cloacal swabs, 102 neck skins from abattoirs, and 100 retail neck skins). Culturing included enrichment in both Bolton and Preston broths followed by isolation on Preston agar and mCCDA. In one or both culture protocols, 169 samples were identified....... A second collaborative trial, with an optimized DNA extraction procedure, gave 100% accuracy results for all three spiking levels. Finally, on-site validation at the abattoir on a flock basis was performed on 400 samples. Real-time PCR correctly identified 10 of 20 flocks as positive; thus, the method...

  6. Selective Growth Inhibitory Effect of Biochanin A Against Intestinal Tract Colonizing Bacteria

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    Olga Sklenickova

    2010-03-01

    Full Text Available Both bifidobacteria and clostridia are part of the natural gut microflora and while clostridia may be responsible for severe intestinal infections, bifidobacteria are probiotic microorganisms belonging to the most important prospective bacteria in the bowel. The antimicrobial activity of biochanin A was tested in vitro against six Bifidobacterium spp., and eight Clostridium spp. using the broth microdilution method. Biochanin A showed an inhibition against all clostridia in the range of minimum inhibitory concentrations (MIC from 64 μg/mL (for Cl. clostridioforme, strains DSM 933 and I3 to 1,024 μg/mL (for Cl. perfringens, DSM 11778. No bifidobacteria were suppressed at four-fold higher concentration (MICs > 4,096 than MIC of Cl. perfringens. These results indicate selective growth inhibition of biochanin A and its potential use in antimicrobial prevention and/or protection.

  7. Synergistic antibacterial activity between Thymus vulgaris and Pimpinella anisum essential oils and methanol extracts.

    Science.gov (United States)

    Al-Bayati, Firas A

    2008-03-28

    Essential oils (EOs) and methanol extracts obtained from aerial parts of Thymus vulgaris and Pimpinella anisum seeds were evaluated for their single and combined antibacterial activities against nine Gram-positive and Gram-negative pathogenic bacteria: Staphylococcus aureus, Bacillus cereus, Escherichia coli, Proteus vulgaris, Proteus mirabilis, Salmonella typhi, Salmonella typhimurium, Klebsiella pneumoniae and Pseudomonas aeruginosa. The essential oils and methanol extracts revealed promising antibacterial activities against most pathogens using broth microdilution method. Maximum activity of Thymus vulgaris and Pimpinella anisum essential oils and methanol extracts (MIC 15.6 and 62.5mug/ml) were observed against Staphylococcus aureus, Bacillus cereus and Proteus vulgaris. Combinations of essential oils and methanol extracts showed an additive action against most tested pathogens especially Pseudomonas aeruginosa.

  8. Antifungal activity of the essential oil of Agastache rugosa Kuntze and its synergism with ketoconazole.

    Science.gov (United States)

    Shin, S; Kang, C-A

    2003-01-01

    To evaluate the fungitoxic activity of the essential oil of Agastache rugosa alone and to determine its combination effect with ketoconazole against Blastoschizomyces capitatus. The antifungal activities of the essential oil of A. rugosa and its main constituent estragole were investigated using the broth microdilution, disk diffusion methods and checkerboard microtitre assay. Both estragole and the essential oil exhibited strong activities against the tested fungi and showed synergism with ketoconazole against B. capitatus. Both estragole and the essential oil of A. rugosa have significant growth-inhibiting activities against B. capitatus showing strong synergistic effect with ketoconazole. The essential oil of A. rugosa, combined with ketoconazole, may be particularly useful against B. capitatus, a rare pathogenic fungus documented to cause severe and fatal mycoses in immunocompromised patients.

  9. Antimicrobial Activity and Essential Oil Composition of Five Sideritis taxa of Empedoclia and Hesiodia Sect. from Greece

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    Aikaterini Koutsaviti

    2013-01-01

    Full Text Available Dried aerial parts of five taxa of Greek Sideritis were subjected to hydrodistillation and the oils obtained were analyzed by using GC and GC-MS. A total of 82 compounds were identified and the analysis showed important differences between the samples not only quantitatively but also qualitatively. The microbial growth inhibitory properties of the essential oils were determined using the broth microdilution method against eight laboratory strains of bacteria - Gram positive: Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Еnterococcus faecalis, Bacillus subtilis and Gram negative: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, a nd two strains of the yeast Candida albicans. The tested essential oils exhibited considerable activity against certain strains of the microorganisms tested, with S. lanata oil presenting MIC values to S. aureus and M. luteus comparable to those of the reference antibiotics. .

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

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    Esther Manso

    2014-12-01

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

  11. Antimicrobial Agents

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    Sigrid Mayrhofer

    2011-01-01

    Full Text Available Strains of the genus Bifidobacterium are frequently used as probiotics, for which the absence of acquired antimicrobial resistance has become an important safety criterion. This clarifies the need for antibiotic susceptibility data for bifidobacteria. Based on a recently published standard for antimicrobial susceptibility testing of bifidobacteria with broth microdilution method, the range of susceptibility to selected antibiotics in 117 animal bifidobacterial strains was examined. Narrow unimodal MIC distributions either situated at the low-end (chloramphenicol, linezolid, and quinupristin/dalfopristin or high-end (kanamycin, neomycin concentration range could be detected. In contrast, the MIC distribution of trimethoprim was multimodal. Data derived from this study can be used as a basis for reviewing or verifying present microbiological breakpoints suggested by regulatory agencies to assess the safety of these micro-organisms intended for the use in probiotics.

  12. Functional Ginger Extracts from Supercritical Fluid Carbon Dioxide Extraction via In Vitro and In Vivo Assays: Antioxidation, Antimicroorganism, and Mice Xenografts Models

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    Chih-Chen Lee

    2013-01-01

    Full Text Available Supercritical fluid carbon dioxide extraction technology was developed to gain the active components from a Taiwan native plant, Zingiber officinale (ginger. We studied the biological effects of ginger extracts via multiple assays and demonstrated the biofunctions in each platform. Investigations of ginger extracts indicated antioxidative properties in dose-dependant manners on radical scavenging activities, reducing powers and metal chelating powers. We found that ginger extracts processed moderate scavenging values, middle metal chelating levels, and slight ferric reducing powers. The antibacterial susceptibility of ginger extracts on Staphylococcus aureus, Streptococcus sobrinus, S. mutans, and Escherichia coli was determined with the broth microdilution method technique. The ginger extracts had operative antimicroorganism potentials against both Gram-positive and Gram-negative bacteria. We further discovered the strong inhibitions of ginger extracts on lethal carcinogenic melanoma through in vivo xenograft model. To sum up, the data confirmed the possible applications as medical cosmetology agents, pharmaceutical antibiotics, and food supplements.

  13. Surveillance of antimicrobial resistance among Escherichia coli from chicken and swine, China, 2008-2015.

    Science.gov (United States)

    Zhang, Peng; Shen, Zhangqi; Zhang, Chunping; Song, Li; Wang, Bing; Shang, Jun; Yue, Xiuying; Qu, Zhina; Li, Xinnan; Wu, Liqin; Zheng, Yongjun; Aditya, Anand; Wang, Yang; Xu, Shixin; Wu, Congming

    2017-05-01

    The objective of this study was to investigate the antimicrobial resistance trend in Escherichia coli from food animals in China. During 2008-2015, a total of 15,130 E. coli were isolated from chicken and swine from seven provinces. The susceptibilities of these isolates to nine classes of antimicrobial agents were determined using broth microdilution susceptibility method. The findings of this study include: (1) multi-drug resistance was highly prevalent in E. coli; (2) these E. coli isolates showed high resistant rate (>80%) to several old drugs, including ampicillin, tetracycline and sulfisoxazole; (3) increasing resistance to colistin, florfenicol and ceftiofur was observed; (4) the E. coli isolates from different provinces had different resistance patterns. All these data highlight the rising problem of antimicrobial resistance. It is urgent to improve the management of animal production and enhance the proper use of antimicrobials in China as well as the other countries. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Antimicrobial and antifungal activities of the extracts and essential oils of Bidens tripartita.

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    Michał Tomczyk

    2008-12-01

    Full Text Available The aim of this study was to determine the antibacterial and antifungal properties of the extracts, subextracts and essential oils of Bidens tripartita flowers and herbs. In the study, twelve extracts and two essential oils were investigated for activity against different Gram-positive Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Gram-negative bacteria Escherichia coli, E. coli (beta-laktamase+, Klebsiella pneumoniae (ESBL+, Pseudomonas aeruginosa and some fungal organisms Candida albicans, C. parapsilosis, Aspergillus fumigatus, A. terreus using a broth microdilution and disc diffusion methods. The results obtained indicate antimicrobial activity of the tested extracts (except butanolic extracts, which however did not inhibit the growth of fungi used in this study. Bacteriostatic effect of both essential oils is insignificant, but they have strong antifungal activity. These results support the use of B. tripartita to treat a microbial infections and it is indicated as an antimicrobial and antifungal agent, which may act as pharmaceuticals and preservatives.

  15. In vitro antifungal activities of leaf extracts of Lippia alba (Verbenaceae against clinically important yeast species

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    Graziela Teixeira de Oliveira

    2014-04-01

    Full Text Available Introduction There are few studies reporting the antifungal activities of Lippia alba extracts. Methods A broth microdilution assay was used to evaluate the antifungal effects of Lippia alba extracts against seven yeast species of Candida and Cryptococcus. The butanol fraction was investigated by gas chromatography-mass spectrometry. Results The butanol fraction showed the highest activity against Candida glabrata. The fraction also acted synergistically with itraconazole and fluconazole against C. glabrata. The dominant compounds in the butanol fraction were 2,2,5-trimethyl-3,4-hexanedione, 3,5-dimethyl-4-octanone and hexadecane. Conclusions The butanol fraction may be a good candidate in the search for new drugs from natural products with antifungal activity.

  16. Volatiles and Antimicrobial Activity of the Essential Oils of the Mosses Pseudoscleropodiumpurum, Eurhynchium striatum, and Eurhynchium angustirete Grown in Turkey

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    Gonca Tosun

    2015-01-01

    Full Text Available The chemical composition of the essential oils from all parts of Pseudoscleropodium purum , Eurhynchium striatum and Eurhynchium angustirete were analysed by GC-FID-MS. Sixty-five, thirty-four and seven compounds, accounting for 99.7%, 97.3% and 99.9% of the oils, were identified and the main components were a - pinene (16.1%, 3-octanone (48.1%, and eicosane (28.6%, respectively. The essential oils were also tested against nine strains using a broth microdilution method and showed moderate antimicrobial activity with minimum inhibitory concentrations (MIC ranging from 278.2 to 2225 µg/mL. All the mosses essential oils showed good antituberculosis activity against Mycobacterium smegmatis with MIC of 278.2-312.0 µg/mL.

  17. Evaluation of antimicrobial activity of extracts of Tibouchina candolleana (melastomataceae, isolated compounds and semi-synthetic derivatives against endodontic bacteria

    Directory of Open Access Journals (Sweden)

    Fernanda M. dos Santos

    2012-06-01

    Full Text Available This work describes the phytochemical study of the extracts from aerial parts of Tibouchina candolleana as well as the evaluation of the antimicrobial activity of extracts, isolated compounds, and semi-synthetic derivatives of ursolic acid against endodontic bacteria. HRGC analysis of the n-hexane extract of T. candolleana allowed identification of b-amyrin, a-amyrin, and b-sitosterol as major constituents. The triterpenes ursolic acid and oleanolic acid were isolated from the methylene chloride extract and identified. In addition, the flavonoids luteolin and genistein were isolated from the ethanol extract and identified. The antimicrobial activity was investigated via determination of the minimum inhibitory concentration (MIC using the broth microdilution method. Amongst the isolated compounds, ursolic acid was the most effective against the selected endodontic bacteria. As for the semi-synthetic ursolic acid derivatives, only the methyl ester derivative potentiated the activity against Bacteroides fragilis.

  18. Antimicrobial susceptibility pattern of Brachyspira intermedia isolates from European layers.

    Science.gov (United States)

    Verlinden, Marc; Boyen, Filip; Pasmans, Frank; Garmyn, An; Haesebrouck, Freddy; Martel, An

    2011-09-01

    A broth microdilution method was used to determine the antimicrobial susceptibility of 20 Brachyspira intermedia isolates obtained from different layer flocks in Belgium and The Netherlands between 2008 and 2010. The antimicrobial agents used were tylosin, tilmicosin, tiamulin, valnemulin, doxycycline, and lincomycin. The minimal inhibitory concentration (MIC) distribution patterns of tylosin, tilmicosin, lincomycin, and doxycycline were bimodal, demonstrating acquired resistance against doxycycline in three strains, against the macrolides in two strains, and against lincomycin in one strain. The MICs of tiamulin and valnemulin showed a monomodal distribution, but with tailing toward the higher MIC values, possibly suggesting low-level acquired resistance in six isolates. Sequencing revealed a G1058C mutation in the 16S rRNA gene in all doxycycline-resistant strains. The strain resistant to tylosin, tilmicosin, and lincomycin had an A2058T mutation in the 23S rRNA gene.

  19. Design, Synthesis, and Biological Activity of New Triazole and Nitro-Triazole Derivatives as Antifungal Agents.

    Science.gov (United States)

    Sadeghpour, Hossein; Khabnadideh, Soghra; Zomorodian, Kamiar; Pakshir, Keyvan; Hoseinpour, Khadijeh; Javid, Nabiollah; Faghih-Mirzaei, Ehsan; Rezaei, Zahra

    2017-07-10

    In this study two series of fluconazole derivatives bearing nitrotriazole (series A) or piperazine ethanol (series B) side chain were designed and synthesized and then docked in the active site of lanosterol 14α-demethylase enzyme (1EA1) using the Autodock 4.2 program (The scripps research institute, La Jolla, CA, USA). The structures of synthesized compound were confirmed by various methods including elemental and spectral (NMR, CHN, and Mass) analyses. Then antifungal activities of the synthesized compound were tested against several natural and clinical strains of fungi using a broth microdilution assay against several standard and clinical fungi. Nitrotriazole derivatives showed excellent and desirable antifungal activity against most of the tested fungi. Among the synthesized compounds, 5a - d and 5g , possessing nitrotriazole moiety, showed maximum antifungal activity, in particular against several fluconazole-resistant fungi.

  20. Synthesis of 1,2,3-triazole derivatives and in vitro antifungal evaluation on Candida strains.

    Science.gov (United States)

    Lima-Neto, Reginaldo G; Cavalcante, Nery N M; Srivastava, Rajendra M; Mendonça Junior, Francisco J B; Wanderley, Almir G; Neves, Rejane P; dos Anjos, Janaína V

    2012-05-16

    1,2,3-Triazoles have been extensively studied as compounds possessing important biological activities. In this work, we describe the synthesis of ten 2-(1-aryl-1H-1,2,3-triazol-4-yl)propan-2-ols via copper catalyzed azide alkyne cycloaddition (CuAAc or click chemistry). Next the in vitro antifungal activity of these ten compounds was evaluated using the microdilution broth method against 42 isolates of four different Candida species. Among all tested compounds, the halogen substituted triazole 2-[1-(4-chlorophenyl)-1H-(1,2,3)triazol-4-yl]propan-2-ol, revealed the best antifungal profile, showing that further modifications could be done in the structure to obtain a better drug candidate in the future.

  1. Design, Synthesis, and Biological Activity of New Triazole and Nitro-Triazole Derivatives as Antifungal Agents

    Directory of Open Access Journals (Sweden)

    Hossein Sadeghpour

    2017-07-01

    Full Text Available In this study two series of fluconazole derivatives bearing nitrotriazole (series A or piperazine ethanol (series B side chain were designed and synthesized and then docked in the active site of lanosterol 14α-demethylase enzyme (1EA1 using the Autodock 4.2 program (The scripps research institute, La Jolla, CA, USA. The structures of synthesized compound were confirmed by various methods including elemental and spectral (NMR, CHN, and Mass analyses. Then antifungal activities of the synthesized compound were tested against several natural and clinical strains of fungi using a broth microdilution assay against several standard and clinical fungi. Nitrotriazole derivatives showed excellent and desirable antifungal activity against most of the tested fungi. Among the synthesized compounds, 5a–d and 5g, possessing nitrotriazole moiety, showed maximum antifungal activity, in particular against several fluconazole-resistant fungi.

  2. Synthesis of 1,2,3-Triazole Derivatives and in Vitro Antifungal Evaluation on Candida Strains

    Directory of Open Access Journals (Sweden)

    Almir G. Wanderley

    2012-05-01

    Full Text Available 1,2,3-Triazoles have been extensively studied as compounds possessing important biological activities. In this work, we describe the synthesis of ten 2-(1-aryl-1H-1,2,3-triazol-4-ylpropan-2-ols via copper catalyzed azide alkyne cycloaddition (CuAAc or click chemistry. Next the in vitro antifungal activity of these ten compounds was evaluated using the microdilution broth method against 42 isolates of four different Candida species. Among all tested compounds, the halogen substituted triazole 2-[1-(4-chlorophenyl-1H-(1,2,3triazol-4-yl]propan-2-ol, revealed the best antifungal profile, showing that further modifications could be done in the structure to obtain a better drug candidate in the future.

  3. Antifungal activity of Oleoresins used in meat industry on some toxigenic Aspergillus spp.

    Directory of Open Access Journals (Sweden)

    Šošo Vladislava M.

    2013-01-01

    Full Text Available Different spice oleoresins are widely used in meat industry. They contribute to the specific aroma and flavor of the end products, but they have also been reported to have strong antimicrobial activity. These properties open a plenty of possibilities to be used for defining the specific sensory profile of the product but also as natural food preservatives. This paper focuses on the antifungal activity of four oleoresins against different foodborne toxigenic Aspergillus species. Oleoresins used in the experiments were cayenne pepper, black pepper, garlic and rosemary oleoresins, and they were tested against following Aspergillus species: A. clavatus, A. flavus, A. fumigatus, A. niger, A. ochraceus and A. versicolor. Antifungal activity was tested using microtitre-plate-based assay incorporating resazurin as an indicator of cell growth and broth microdilution-method. [Projekat Ministarstva nauke Republike Srbije, br. III46009

  4. Antimicrobial activity of Satureja hortensis L. essential oil against pathogenic microbial strains

    Directory of Open Access Journals (Sweden)

    Mihajilov-Krstev Tatjana

    2010-01-01

    Full Text Available A hydro-distilled oil of Satureja hortensis L. was investigated for its antimicrobial activity against a panel of 11 bacterial and three fungal strains. The antimicrobial activity was determined using the disk-diffusion and broth microdilution methods. The essential oil of S. hortensis L. showed significant activity against a wide spectrum of Gram (- bacteria (MIC/MBC=0.025-0.78/0.05-0.78 μl/ml and Gram (+ bacteria (MIC/MBC=0.05-0.39/0.05-0.78 μl/ml, as well as against fungal strains (MIC/MBC=0.20/0.78 μl/ml. The results indicate that this oil can be used in food conservation, treatment of different diseases of humans, and also for the treatment of plants infected by phytopathogens.

  5. Chemical composition and antibacterial activity of the essential oil the leaf of Nepeta persica

    Directory of Open Access Journals (Sweden)

    Soraya AKHSHI

    2014-11-01

    Full Text Available The essential oil from the leaf of Nepeta persica Boiss, analyzed by gas chromatography (GC and gas chromatography (GC/mass spectrometry (MS, were shown to contain 4aα, 7α, 7aβ-nepetalactone (49.46% and 4aα, 7α, 7aα-nepetalactone (14.18%. The other main constituents were n-octane (13.10%, n-decane (3.67% and germacrene-D (2.04%. Antibacterial activities of the leaf oil were evaluated using the micro-dilution broth method. Inhibitory effects on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Enterococcus faecalis were recorded. The leaf oil has difference activities against the test microorganisms. The antibacterial property of the essential oil might be ascribed to their high content of nepetalactone isomers.

  6. Microwave assisted synthesis of novel 4h-chromene derivatives bearing phenoxypyrazole and their antimicrobial activity assess

    Directory of Open Access Journals (Sweden)

    Sangani Chetan B.

    2012-01-01

    Full Text Available A new series of 4H-chromene derivatives 4(a-p bearing 5-phenoxypyrazole nucleus has been synthesized under microwave irradiation by reaction of 5-phenoxypyrazole-4-carbaldehyde 1(a-h, malononitrile 2 and compounds (Cyclohexanedione, Dimedon 3(a-b in presence of NaOH as basic catalyst. All the compounds were screened against three Gram positive bacteria (Streptococcus pneumoniae, Clostridium tetani, Bacillus subtilis, three Gram negative bacteria (Salmonella typhi, Vibrio cholerae, Escherichia coli and two fungi (Aspergillus fumigatus, Candida albicans using broth microdilution MIC (Minimum Inhibitory Concentration method. Upon study of antimicrobial screening, it has been observed that, majority of the compounds were found to be active against Clostridium tetani and Bacillus subtilis as well as against Candida albicans as compared to standard drugs.

  7. Activity of ceftibuten, cefaclor, azithromycin, clarithromycin, erythromycin and telithromycin against Streptococcus pyogenes clinical isolates with different genotypes and phenotypes.

    Science.gov (United States)

    Drago, Lorenzo; Ripa, Sandro; Zampaloni, Claudia; De Vecchi, Elena; Vitali, Luca A; Petrelli, Dezemona; Prenna, Manuela

    2005-08-01

    The growing number of macrolide-resistant strains of Streptococcus pyogenes represents an increasing worldwide problem. Macrolide resistance in S. pyogenes is mediated by several different genes, which determine different levels of resistance to macrolides, lincosamides and streptogramin B (MLS). This study compared the in vitro antimicrobial activity of azithromycin, clarithromycin, erythromycin, ceftibuten, cefaclor, and telithromycin against 287 strains of S. pyogenes by the broth microdilution method. All strains were characterized both phenotypically and genotypically for erythromycin resistance and most of them have been M-typed by means of PCR. Ceftibuten and cefaclor showed the best antimicrobial activity, while MIC values for telithromycin were higher against constitutively MLS (cMLS)-resistant strains rather than against the other phenotypes. Oral cephalosporins retain the best activity against S. pyogenes; showing good activity except for cMLS-resistant strains, telithromycin is a valid alternative to these antimicrobials. Copyright 2005 S. Karger AG, Basel.

  8. MRSA carrying mecC in captive mara

    DEFF Research Database (Denmark)

    Gongora, Carmen Espinosa; Harrison, Ewan M; Moodley, Arshnee

    2015-01-01

    OBJECTIVES: To characterize the staphylococcal cassette chromosome mec (SCCmec), virulence and antimicrobial susceptibility of Staphylococcus aureus ST130 isolated from mara (Dolichotis patagonum), a large rodent species native to South America and kept in captivity at Copenhagen Zoo. METHODS......: The presence of mecC was confirmed by PCR in 15 S. aureus ST130 isolated from mara during a previous study. WGS was performed on two randomly selected isolates to characterize their genomes with respect to SCCmec, virulence and resistance gene content. Antimicrobial susceptibility was tested using commercial...... broth microdilution tests. RESULTS: All the isolates belonged to spa type t528 ST130 and carried mecC. Based on WGS, mecC was 100% identical to the prototype sequence of S. aureus strain LGA251. The sequence of SCCmec type XI in the mara isolates had 23 SNPs compared with the one described in LGA251...

  9. Zn(II), Ni(II), Cu(II) and Pb(II) complexes of tridentate asymmetrical Schiff base ligands: Synthesis, characterization, properties and biological activity

    Science.gov (United States)

    Şahin, Mustafa; Koçak, Nuriye; Erdenay, Damla; Arslan, Uğur

    2013-02-01

    New asymmetrical tridentate Schiff base ligands were synthesized using 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde, 9-anthracenecarboxaldehyde. Schiff base ligands and their metal complexes were synthesised and characterized by using FT-IR, 1H NMR, 13C NMR, UV-Vis, XRD, ESR, elemental analysis and fluorescence studies. The antimicrobial activity of the ligands and their metal complexes were studied against Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, Streptococcus mutans RSHM 676, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853. The determination of the antibacterial activity was done using the broth microdilution methods. In general, it has been determined that the studied compounds have MIC values similar to Gram-positive and Gram-negative bacteria. It has been found that Ni, Pb, Zn derivatives of HL1A and ZnL2A has lower MIC values than ampicillin for P. aeruginosa ATCC 27853 strain.

  10. In Vitro and In Vivo Activities of Antimicrobials against Nocardia brasiliensis

    Science.gov (United States)

    Gomez-Flores, Alejandra; Welsh, Oliverio; Said-Fernández, Salvador; Lozano-Garza, Gerardo; Tavarez-Alejandro, Roman Erick; Vera-Cabrera, Lucio

    2004-01-01

    In Mexico mycetomas are mostly produced by Nocardia brasiliensis, which can be isolated from about 86% of cases. In the present work, we determined the sensitivities of 30 N. brasiliensis strains isolated from patients with mycetoma to several groups of antimicrobials. As a first screening step we carried out disk diffusion assays with 44 antimicrobials, including aminoglycosides, cephalosporins, penicillins, quinolones, macrolides, and some others. In these assays we observed that some antimicrobials have an effect on more than 66% of the strains: linezolid, amikacin, gentamicin, isepamicin, netilmicin, tobramycin, minocycline, amoxicillin-clavulanic acid, piperacillin-tazobactam, nitroxolin, and spiramycin. Drug activity was confirmed quantitatively by the broth microdilution method. Amoxicillin-clavulanic acid, linezolid, and amikacin, which have been used to treat patients, were tested in an experimental model of mycetoma in BALB/c mice in order to validate the in vitro results. Linezolid showed the highest activity in vivo, followed by the combination amoxicillin-clavulanic acid and amikacin. PMID:14982772

  11. Screening of medicinal plants for antibacterial activities on Staphylococcus aureus strains isolated from bovine mastitis

    Directory of Open Access Journals (Sweden)

    Marisa A. N. Diaz

    2010-08-01

    Full Text Available Staphylococcus aureus is the main causative agent of bovine mastitis. The activity of several extracts from ten medicinal plants traditionally used in Brazil as antiseptic was investigated against fifteen strains of Staphylococcus aureus isolated from animals with mastitis manifestation by the disc diffusion method and broth microdilution assay. The interference of the extracts on cell in the form of adherent colonies was also evaluated. MIC values ranged from 0.5 mg/mL to 1.0 mg/mL and biofilm inhibitory concentration (BIC were between 0.25 mg/mL and 0.8 mg/mL. Results revealed the potential of extracts of Senna macranthera, Artemisia absinthium, Cymbopogon nardus and Baccharis dracunculifolia as antibacterial agents against S. aureus strains isolated from bovine mastitis and support the possible use of these phytotherapic agents in the clinical management of the disease.

  12. Antimicrobial activity of Aegiphila sellowiana Cham., Lamiaceae, against oral pathogens

    Directory of Open Access Journals (Sweden)

    Marcele A. Ferreira

    Full Text Available The antimicrobial activity of Aegiphila sellowiana Cham., Lamiaceae, against oral pathogens is reported. The Minimal Inhibitory Concentrations (MICs for inhibiting the microorganisms growth were determined using the broth microdilution method from the CLSI M7-A7 protocol. Chlorhexidine was used as the positive control. The ethanol crude extract of the aerial parts of A. sellowiana exhibited activity against the microorganisms tested in this work; however, the activity decreased after partition with n-hexane, dichloromethane, and ethyl acetate. Among the tested fractions, the n-hexane fraction was found to be the most effective against the evaluated oral pathogens. GC-MS analysis of this latter fraction revealed that fatty acids esters, steroids, and aliphatic sesquiterpene hydrocarbons are its major constituents. These compounds may be responsible for the activity of the n-hexane fraction, but other chemical constituents of the dichloromethane, ethyl acetate, and hydroalcoholic fraction may potentialize their activities in the crude extract.

  13. Ceftaroline activity tested against contemporary Latin American bacterial pathogens (2011

    Directory of Open Access Journals (Sweden)

    Robert K. Flamm

    Full Text Available A total of 2484 target bacterial pathogens were collected (one per patient episode from patients in 16 Latin American medical centers located in seven nations during 2011. Isolate identity was confirmed at a coordinating laboratory and susceptibility testing was performed for ceftaroline and comparator agents according to reference broth microdilution methods. A total of 30.0% of isolates were from respiratory tract, 29.4% from skin and skin structure, 21.4% from blood stream, 7.9% from urinary tract and 11.3% from other sites. Ceftaroline was active againstStaphylococcus aureus (42.8% MRSA with 83.6% of the isolates at 90.0% of the non-ESBL-phenotype. The spectrum of activity of ceftaroline against pathogens from Latin America indicates that it merits further study for its potential use in the Latin American region.

  14. Carboxymethylated chitosan-stabilized copper nanoparticles: a promise to contribute a potent antifungal and antibacterial agent

    Energy Technology Data Exchange (ETDEWEB)

    Tantubay, Sangeeta, E-mail: sang.chem2@gmail.com [Indian Institute of Technology Kharagpur, Department of Chemistry (India); Mukhopadhyay, Sourav K. [Indian Institute of Technology Kharagpur, Department of Biotechnology (India); Kalita, Himani; Konar, Suraj [Indian Institute of Technology Kharagpur, Department of Chemistry (India); Dey, Satyahari [Indian Institute of Technology Kharagpur, Department of Biotechnology (India); Pathak, Amita, E-mail: ami@chem.iitkgp.ernet.in; Pramanik, Panchanan, E-mail: ppramanik1946@yahoo.in, E-mail: pramanik1946@gmail.com [Indian Institute of Technology Kharagpur, Department of Chemistry (India)

    2015-06-15

    Carboxymethylated chitosan (CMC)-stabilized copper nanoparticles (Cu-NPs) have been synthesized via chemical reduction of copper(II)–CMC complex in aqueous medium by hydrazine under microwave irradiation in ambient atmosphere. Structural morphology, phase, and chemical compositions of CMC-stabilized Cu-NPs (CMC–Cu-NPs) have been analyzed through high-resolution transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Antifungal and antibacterial activities of CMC–Cu-NPs have been evaluated against Candida tropicalis and Escherichia coli through agar well diffusion method, broth microdilution assay, live–dead assay, and microscopic observation. Antimicrobial activity of spherical CMC–Cu-NPs (∼4–15 nm of diameters) has been observed to be significant for both C. tropicalis and E. coli. The cytotoxicity study indicates that CMC–Cu-NPs have no significant toxic effect against normal cell line, L929.

  15. Management of Cosmetic Embarrassment Caused by Malassezia spp. with Fruticose Lichen Cladia Using Phylogenetic Approach

    Directory of Open Access Journals (Sweden)

    Anand Pandey

    2013-01-01

    Full Text Available During anti-Malassezia screening of plants by CLSI broth microdilution method, Cladia aggregata (Swartz Nyl. (family Cladoniaceae, a fruticose lichen from Sikkim (northeast Himalayan region, has been found effective at minimum inhibitory concentrations (mg/mL of 2.72, 0.63, and 1.28 against yeast-like fungi namely, M. furfur, M. globosa and M. sympodialis, respectively. These test pathogens are responsible for pityriasis versicolor (PV and seborrheic dermatitis (SD in humans. We tried to establish the reason for variable MICs against various Malassezia spp. using bioinformatical tools, thereby reducing the cost of the experimentation. This is the first report on anti-Malassezia activity of C. aggregata and thus can serve as a potential source for the development of cosmaceuticals.

  16. Differences in the antimicrobial susceptibility profiles of Moraxella bovis, M. bovoculi and M. ovis

    Directory of Open Access Journals (Sweden)

    Grazieli Maboni

    2015-06-01

    Full Text Available The aim of this study was to determine the differences in the antimicrobial susceptibility profiles of Moraxella bovis, M. bovoculi and M. ovis. Thirty-two strains of Moraxella spp. isolated from cattle and sheep with infectious keratoconjunctivitis were tested via broth microdilution method to determine their susceptibility to ampicillin, cefoperazone, ceftiofur, cloxacillin, enrofloxacin, florfenicol, gentamicin, neomycin, oxytetracycline and penicillin. The results demonstrated that Moraxella spp. strains could be considered sensitive for most of the antimicrobials tested in this study, but differences between the antimicrobial susceptibility profiles of these three Moraxella species were found. M. bovis might differ from other species due to the higher MIC and MBC values it presented.

  17. Non-tuberculous mycobacteria mimic of MDR-TB infection in Pott's disease.

    Science.gov (United States)

    Kumar, Manoj; Verma, Sheetal; Dhole, Tapan N; Kumar, Raj

    2016-09-23

    A 34 year-old woman presented with history of progressive back pain which was diagnosed as Pott's disease with recurrent paravertebral abscess, and had received a total of 23 months of antitubercular treatment for lumbar infection. The patient was non-responsive to treatment and was referred to a higher centre where the infection was finally identified as non-tuberculous mycobacterium (Mycobacterium fortuitum) by genotypic testing. The drugs were initiated according to results of drug susceptibility testing by the broth microdilution method. We describe here an unusual case of M. fortuitum infection that presented as Pott's disease identified by molecular test which was followed by treatment and successful cure of the disease. 2016 BMJ Publishing Group Ltd.

  18. Perturbation methods

    CERN Document Server

    Nayfeh, Ali H

    2008-01-01

    1. Introduction 1 2. Straightforward Expansions and Sources of Nonuniformity 23 3. The Method of Strained Coordinates 56 4. The Methods of Matched and Composite Asymptotic Expansions 110 5. Variation of Parameters and Methods of Averaging 159 6. The Method of Multiple Scales 228 7. Asymptotic Solutions of Linear Equations 308 References and Author Index 387 Subject Index 417

  19. AVALIAÇÃO DOS MÉTODOS DE ETEST E MICRODILUIÇÃO EM CALDO PARA O ESTUDO DA SUSCETIBILIDADE DO Sporothrix schenckii COM O ITRACONAZOL

    Directory of Open Access Journals (Sweden)

    Ana Raquel Mano Meinerz

    2010-06-01

    Full Text Available The frequent occurrence of resistant isolated fungi againstantifungal drugs stimulated advances in the antifungigram techniques,which were standardized by CLSI. However, the methods have been inefficient and impractical to be executed in clinical laboratories. Within this context, commercial techniques have been developed, being ETEST one of them. ETEST has proved to be easier to execute when compared to the techniques approved by the CLSI. This study used the ETEST and the microdilution method, performed according to CLSI, for determining the in vitro susceptibility of isolates of Sporothrix schenckii against itraconazole. The CLSI uses RPMI 1640 medium and the reading of MIC after the period of incubation of 72h at 35ºC. MIC was determined by the ETEST, being Sabouraud dextrose agar used as medium, and the reading performed after 72 hours of incubation at 35ºC. The variance analysis, analyzed by T-paired test, did not demonstrate statistical differences among the CIM values obtained by the microdilution technique in broth (MIC among 0.219 and 0.875 μg/mL and ETEST (MIC among 0.032 and 2.0 μg/mL. However, the correlation coefficient (R was negative, probably because ofthe small number of samples. These results show the necessity offurther studies to assess the application of ETEST to evaluate thesusceptibility of S. schenckii against the itraconazol.

  20. In vitro assessment of the antimicrobial susceptibility of caprine isolates of Mycoplasma mycoides subsp. capri.

    Science.gov (United States)

    Paterna, A; Tatay-Dualde, J; Amores, J; Prats-van der Ham, M; Sánchez, A; de la Fe, C; Contreras, A; Corrales, J C; Gómez-Martín, Á

    2016-08-01

    The minimum inhibitory concentration (MIC) and minimum mycoplasmacidal concentration (MMC) of 17 antimicrobials against 41 Spanish caprine isolates of Mycoplasma mycoides subsp. capri (Mmc) obtained from different specimens (milk, external auricular canal and semen) were determined using a liquid microdilution method. For half of the isolates, the MIC was also estimated for seven of the antimicrobials using an epsilometric test (ET), in order to compare both methods and assess the validity of ET. Mutations in genes gyrA, gyrB, parC and parE conferring fluoroquinolone resistance, which have been recently described in Mmc, were investigated using PCR. The anatomical origin of the isolate had no effect on its antimicrobial susceptibility. Moxifloxacin and doxycycline had the lowest MIC values. The rest of the fluoroquinolones studied (except norfloxacin), together with tylosin and clindamycin, also had low MIC values, although the MMC obtained for clindamycin was higher than for the other antimicrobials. For all the aminoglycosides, spiramycin and erythromycin, a notable level of resistance was observed. The ET was in close agreement with broth microdilution at low MICs, but not at intermediate or high MICs. The analysis of the genomic sequences revealed the presence of an amino acid substitution in codon 83 of the gene gyrA, which has not been described previously in Mmc. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. ANTIBACTERIAL PROFILE OF PEUCEDANUM LONGIFOLIUM ESSENTIAL OIL

    Directory of Open Access Journals (Sweden)

    Budimir Ilić

    2015-03-01

    Full Text Available In the present study, the chemical composition and antibacterial activity of Peucedanum longifolium Waldst. & Kit. (Apiaceae essential oil were examined, as well as the association between it and standard antibiotics. Gas chromatography and gas chromatography/mass spectrometry were used to analyze the chemical composition of the oil. The antibacterial activity of the oil was investigated by the broth microdilution method against thirteen bacterial strains. The interactions of the essential oil with three conventional antibiotics: tetracycline, streptomycin and chloramphenicol toward five selected bacterial strains were evaluated using the microdilution checkerboard assay. Monoterpene hydrocarbons (61.60%, with myrcene (15.88% as the dominant constituent, were the most abundant compound class of the essential oil of P. longifolium from Serbia. The researched essential oil exhibited slight antibacterial activity against the tested bacterial strains in vitro. On the contrary, essential oil of P. longifolium posseses significant synergistic potential in combination with streptomycin and chloramphenicol (FIC indices in the range 0.21–0.87. Their combinations reduced the minimum effective dose of the antibiotic and, consequently, minimized its adverse side effects. In addition, investigated interactions are especially successful against Gram-negative bacteria, the pharmacological treatment of which is very difficult nowadays. These results indicate a method to enhance the efficacy of antibacterial drugs, especially against resistant bacterial strains.

  2. Anti-Candida albicans effectiveness of citral and investigation of mode of action.

    Science.gov (United States)

    Lima, Igara Oliveira; de Medeiros Nóbrega, Fernanda; de Oliveira, Wylly Araújo; de Oliveira Lima, Edeltrudes; Albuquerque Menezes, Everardo; Cunha, Francisco Afrânio; Formiga Melo Diniz, Margareth de Fátima

    2012-12-01

    Candidiasis is a mycosis caused by Candida species, which is of clinical importance due to the increase in resistant yeasts. Candida infection has been a serious health problem due to the inappropriate use of antibiotics. Therefore, it is necessary to study molecules with an antifungal action. Citral is a monoterpene with known pharmacological properties, including antimicrobial action. The aim of this work was to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of citral and the probable mode of action. The MIC of citral was determined by the broth microdilution method using Sabouraud dextrose medium. Additionally, the interference of citral in cell wall (sorbitol assay) and the binding of citral to ergosterol and cholesterol were studied, carried out by broth microdilution method. The MIC and MFC of citral were 512 and 1024 µg/mL, respectively. The MIC of amphotericin B was 1 µg/mL. The mechanism of action did not involve either the cell wall or ergosterol. However, the presence of cholesterol increased the MIC of citral to 1024 µg/mL, indicating there is some interaction between citral and cholesterol. Amphotericin B was used as the positive control, and it showed a high MIC in the presence of ergosterol (32 µg/mL), while in the presence of cholesterol MIC increased to 4 µg/mL. Citral inhibits the growth of C. albicans. The probable mechanism of action did not involve the cell wall or ergosterol. Citral is able to interact with cholesterol. More studies are necessary to describe their effects completely.

  3. Prevalence and Antimicrobial Resistance of Campylobacter Isolated from Dressed Beef Carcasses and Raw Milk in Tanzania.

    Science.gov (United States)

    Kashoma, Isaac P; Kassem, Issmat I; John, Julius; Kessy, Beda M; Gebreyes, Wondwossen; Kazwala, Rudovick R; Rajashekara, Gireesh

    2016-01-01

    Campylobacter species are commonly transmitted to humans through consumption of contaminated foods such as milk and meat. The aim of this study was to investigate the prevalence, antimicrobial resistance, and genetic determinants of resistance of Campylobacter isolated from raw milk and beef carcasses in Tanzania. The antimicrobial resistance genes tested included blaOXA-61 (ampicillin), aph-3-1 (aminoglycoside), tet(O) (tetracycline), and cmeB (multi-drug efflux pump). The prevalence of Campylobacter was 9.5% in beef carcasses and 13.4% in raw milk, respectively. Using multiplex-polymerase chain reaction (PCR), we identified 58.1% of the isolates as Campylobacter jejuni, 30.7% as Campylobacter coli, and 9.7% as other Campylobacter spp. One isolate (1.6%) was positive for both C. jejuni and C. coli specific PCR. Antimicrobial susceptibility testing using the disk diffusion assay and the broth microdilution method showed resistance to: ampicillin (63% and 94.1%), ciprofloxacin (9.3% and 11.8%), erythromycin (53.7% and 70.6%), gentamicin (0% and 15.7%), streptomycin (35.2% and 84.3%), and tetracycline (18.5% and 17.7%), respectively. Resistance to azithromycin (42.6%), nalidixic acid (64.8%), and chloramphenicol (13%) was determined using the disk diffusion assay only, while resistance to tylosin (90.2%) was quantified using the broth microdilution method. The blaOXA-61 (52.6% and 28.1%), cmeB (26.3% and 31.3%), tet(O) (26.3% and 31.3%), and aph-3-1 (5.3% and 3.0%) were detected in C. coli and C. jejuni. These findings highlight the extent of antimicrobial resistance in Campylobacter occurring in important foods in Tanzania. The potential risks to consumers emphasize the need for adequate control approaches, including the prudent use of antimicrobials to minimize the spread of antimicrobial-resistant Campylobacter.

  4. Antimicrobial Resistance and Genotypic Diversity of Campylobacter Isolated from Pig, Dairy and Beef Cattle in Tanzania

    Directory of Open Access Journals (Sweden)

    Isaac eKashoma

    2015-11-01

    Full Text Available Foodborne Campylobacter infections pose a serious threat to public health worldwide. However, the occurrence and characteristics of Campylobacter in food animals and products remain largely unknown in Tanzania. The objective of this study was to determine the prevalence, antibiotic resistance, and genetic profiles (sequence types, STs of Campylobacter isolated from feces of pigs and dairy and beef cattle in Tanzania. Overall, 259 (~ 30% of 864 samples were positive for Campylobacter spp, which were detected in 32.5%, 35.4%, and 19.6% of the pig, dairy, and beef cattle samples, respectively. Multiplex PCR analysis identified 64.5% and 29.3% of the Campylobacter isolates as C. coli and C. jejuni, respectively. The majority (91.9% of the isolates from pig samples were identified as C. coli, while C. jejuni accounted for 65.5% of the isolates from cattle. Antimicrobial susceptibility testing using the disk diffusion assay and the broth microdilution method revealed resistance to: ampicillin (70% and 76%, gentamicin (1.8% and 12.6%, respectively, streptomycin (65.8% and 74.8%, erythromycin (41.4% and 48.7%, tetracycline (18.9% and 23.4%, and ciprofloxacin (14.4% and 7.2%. Resistance to nalidixic acid (39.6%, azithromycin (13.5%, and chloramphenicol (4.5% was determined using the disk diffusion assay only, while resistance to tylosin (38.7% was quantified using the broth microdilution method. Multilocus sequence typing of 111 Campylobacter isolates resulted in the identification of 48 STs (26 C. jejuni and 22 C. coli of which 7 were novel (6 C. jejuni and 1 C. coli. Taken together, this study revealed the high prevalence, genetic diversity and antimicrobial resistance of Campylobacter in important food animals in Tanzania, which highlights the urgent need for the surveillance and control of Campylobacter in this country.

  5. Method Comparison for Enhanced Recovery, Isolation and Qualitative Detection of C. jejuni and C. coli from Wastewater Effluent Samples

    Directory of Open Access Journals (Sweden)

    María Ugarte-Ruiz

    2015-03-01

    Full Text Available Seeking a sensitive protocol, culture-dependent methods were compared to detect thermophilic Campylobacter species in untreated urban effluents. We evaluated various combinations of selective media, with and without an enrichment steps, as well as an extra filtration step. Culture-independent real-time quantitative PCR was also included and all detected isolates underwent antimicrobial susceptibility testing. All tested water samples contained Campylobacter DNA, but only 64% were positive after culture. Although enrichment using Preston broth resulted in better recovery of potentially stressed Campylobacter than Bolton or Campyfood broth (CFB, there was no significant increase in efficiency compared to direct plating. The type of selective agar media used, on the other hand, had a significant effect, with CASA plates performing better than mCCDA or CFA ones. Inclusion of an enrichment step increased the ratio of C. coli vs. C. jejuni being isolated. Resistances against all antimicrobials tested were observed in C. coli, but fewer instances of resistance were found in C. jejuni isolates. Whether this difference was the result of selection during the enrichment step could not be determined. The presence of Campylobacter in urban effluents can be considered as a valuable proxy for Campylobacter populations present in urban environments.

  6. Method comparison for enhanced recovery, isolation and qualitative detection of C. jejuni and C. coli from wastewater effluent samples.

    Science.gov (United States)

    Ugarte-Ruiz, María; Florez-Cuadrado, Diego; Wassenaar, Trudy M; Porrero, María Concepción; Domínguez, Lucas

    2015-03-02

    Seeking a sensitive protocol, culture-dependent methods were compared to detect thermophilic Campylobacter species in untreated urban effluents. We evaluated various combinations of selective media, with and without an enrichment steps, as well as an extra filtration step. Culture-independent real-time quantitative PCR was also included and all detected isolates underwent antimicrobial susceptibility testing. All tested water samples contained Campylobacter DNA, but only 64% were positive after culture. Although enrichment using Preston broth resulted in better recovery of potentially stressed Campylobacter than Bolton or Campyfood broth (CFB), there was no significant increase in efficiency compared to direct plating. The type of selective agar media used, on the other hand, had a significant effect, with CASA plates performing better than mCCDA or CFA ones. Inclusion of an enrichment step increased the ratio of C. coli vs. C. jejuni being isolated. Resistances against all antimicrobials tested were observed in C. coli, but fewer instances of resistance were found in C. jejuni isolates. Whether this difference was the result of selection during the enrichment step could not be determined. The presence of Campylobacter in urban effluents can be considered as a valuable proxy for Campylobacter populations present in urban environments.

  7. expansion method

    Indian Academy of Sciences (India)

    In this paper, we shall apply the (G /G)-expansion method to obtain the exact travelling wave solution of the two-dimensional ... In §3, we apply our method to the mentioned equations. In §4, some conclusions are ..... The exact solution obtained by this method can be used to check computer codes or as initial condition for ...

  8. The evaluation of a PCR-based method for identification of Salmonella enterica serotypes from environmental samples and various food matrices.

    Science.gov (United States)

    Jean-Gilles Beaubrun, Junia; Cheng, Chorng-Ming; Chen, Kai-Shun; Ewing, Laura; Wang, Hua; Agpaoa, Maria C; Huang, Mei-Chiung J; Dickey, Erin; Du, Jamie M; Williams-Hill, Donna M; Hamilton, Brittany; Micallef, Shirley A; Rosenberg Goldstein, Rachel E; George, Ashish; Joseph, Sam W; Sapkota, Amy R; Jacobson, Andrew P; Tall, Ben D; Kothary, Mahendra H; Dudley, Kim; Hanes, Darcy E

    2012-09-01

    The most commonly used method for serotyping Salmonella spp. is based on the Kaufmann-White scheme, and is composed of serological reactions using antibodies to LPS agglutinins. The multiplex PCR used in this investigation was established by Kim et al. to serotype the 30 most common clinical Salmonella serotypes, as determined by CDC. The PCR assay consists of two five-plex reactions and a single two-plex PCR reaction, based on six genetic loci from Salmonella enterica serotype Typhimurium and four loci from S. enterica serotype Typhi. In this investigation, we further evaluated the method for serotyping Salmonella spp. using a reference collection, environmental samples collected from a Mid-Atlantic region tomato farm study, four food matrices spiked with different Salmonella serotypes and a proficiency test. The PCR assay was first evaluated using DNA isolated from pure cultures of isolates obtained from various clinical and environmental samples, and then DNA isolated from broth cultures of food matrices of "Red round" and Roma tomatoes, Romaine lettuce, green onions and Serrano peppers spiked with serotypes Newport, Typhimurium, Javiana and Saintpaul, respectively. The results showed that the PCR assay correctly serotyped Salmonella spp. from the clinical, environmental, spiked food matrices, and proficiency test samples. These findings are significant because the PCR assay was successful in the identification of Salmonella in the spiked samples in a broth culture containing other non-salmonella organism. This method may be a useful resource for the food safety community. Published by Elsevier Ltd.

  9. Are the Best Broths Really Made in the Oldest Pots?

    DEFF Research Database (Denmark)

    Gravier, Magali

    explanations than the two theories which have dominated the scholarly debate since the creation of the EC/EU and than the new theories, which don't really succeed in challenging the old ones? What exactly is the added value of this concept? Should we bother using it at all? This paper presents a critical...... the integration process is taking a different path? Is it because the explanatory potential of standard theories of integration has been exhausted while the so-called ‘new theories of integration’ are disappointing because they aren’t really theories of integration? But can the concept of empire provide better...

  10. Reverse Osmosis Processing of Organic Model Compounds and Fermentation Broths

    Science.gov (United States)

    2006-04-01

    followed by RO treatment step for water recycling in electronic industry (Chen and Chen, 2004), meat processing industry (Bohdziewicz and Sroka, 2005...Membr. Sci. 255, 117–124. Todtheide, V., Laufenberg, G., Kunz, B., 1997. Waste water treatment using reverse osmosis: real osmotic pressure and chemical...A., Inanc, B., 2002. Fouling of reverse osmosis and nanofiltration membranes by dairy industry effluents. Water Sci. Technol. 45 (12), 355–360

  11. AIDS: a nightmare ingredient in the Indonesian development broth.

    Science.gov (United States)

    Green, C

    2000-06-01

    In Indonesia, evidence indicates that HIV infections have decreased during the 1990s. Estimates by the WHO put sexually transmitted HIV infections at 25,000 among the more than 200 million population of the country. However, reports from other countries suggest that injecting drug users (IDUs) are potentially becoming a threat to the success of AIDS-preventive programs. This is because of the huge explosion of drug use among young people, which in turn has resulted in a rise in HIV infections with communal needle use in recent years. Available data suggest that Indonesia could experience an overall 50% prevalence of HIV among the over 1 million IDUs within 1 or 2 years. Although it is the responsibility of the Indonesian government to respond to this health crisis, in its bankrupt state it can only be hoped that it will be able to put into place a framework that will allow the community, nongovernmental organizations, and donors to work together with minimum restrictions.

  12. Antibacterial Investigation of Thyme Essential Oil and Its Main Constituents in Combination with Tetracycline.

    Science.gov (United States)

    Miladinović, Dragoljub L; Ilić, Budimir S; Kocić, Branislava D; Ćirić, Vojislav M; Nikolić, Dejan M

    2015-08-01

    The chemical composition and antibacterial activity of Thymus glabrescens Willd. (thyme) essential oil were examined, as well as its association with tetracycline. The antibacterial activities of geraniol and thymol, the main constituents of T. glabrescens oil, were also determined. Gas chromatography and gas chromatography/mass spectrometry were used to analyze the chemical composition of the oil. The antibacterial activities of the oil, geraniol, and thymol were investigated by the broth microdilution method. The interactions of the essential oil, geraniol, and thymol with tetracycline, toward five selected strains, were evaluated using the microdilution checkerboard assay. Oxygenated monoterpenes were the most abundant compound class in the oil (57.14%), with geraniol (22.33%) as the major compound. The essential oil exhibited in vitro antibacterial activity against all tested bacterial strains. The combinations, essential oil-tetracycline and thymol-tetracycline, produced synergistic interaction to a greater extent compared with geraniol-tetracycline association. All synergistic combinations reduced the minimum effective dose of the antibiotic and, consequently, minimized its adverse side effects.

  13. In vitro activity of calcium channel blockers in combination with conventional antifu