WorldWideScience

Sample records for broth microdilution method

  1. Standartization of broth microdilution method for Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Leite Clarice Queico Fujimura

    2000-01-01

    Full Text Available Indirect drug susceptibility tests of Mycobacterium tuberculosis was done to investigate the accuracy and feasibility of a broth microdilution method (BMM for determining minimal inhibitory concentrations of conventional drugs against M. tuberculosis. Test drugs included isoniazid (H, rifampicin (R, ethambutol (E, streptomycin (S and pyrazinamide (Z. Fifty isolates of M. tuberculosis from patients who had never received drug therapy, and H37Rv strain for control, were evaluated in the system. When comparing this method with the gold standard proportional method in Lowenstein-Jensen medium, sensitivity of 100% for all drugs and specifities of 91, 100, 96, 98 and 85% were observed respectively for H, R, E, S and Z. The BMM was read faster (14-20 days than the proportional method (20-28 days. The microdilution method evaluated allows the testing of multiple drugs in multiple concentrations. It is easy to perform and does not require special equipment or expensive supplies. In contrast to radiometric method it does not use radioactive material.

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

    Directory of Open Access Journals (Sweden)

    Ahmet Yilmaz Coban

    2004-02-01

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

  3. 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

    -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...

  4. CLSI broth microdilution method for testing susceptibility of Malassezia pachydermatis to thiabendazole.

    Science.gov (United States)

    Nascente, Patrícia da Silva; Meinerz, Ana Raquel Mano; de Faria, Renata Osório; Schuch, Luiz Filipe Damé; Meireles, Mário Carlos Araújo; de Mello, João Roberto Braga

    2009-04-01

    Thiabendazole, classified as antiparasitic and also used as an antifungal drug, can be found as otological solution indicated for treatment of parasitic and fungal external otitis in small animals. Malassezia pachydermatis is a yeast recognized as a normal inhabitant on the skin and mucous membranes of dogs and cats. However, it is considered an opportunistic agent that causes external otitis and dermatitis in these animals. The aim of this study was to evaluate the in vitro effect of thiabendazole against 51 isolates of M. pachydermatis using the CLSI Broth Microdilution method that has been adapted for this yeast species (NCCLS, 2002). Based on this test, the Minimum Inhibitory Concentrations (MIC) of thiabendazol was calculated. Subsequently, the susceptibility of each isolate against this antifungal was determined. It was observed that the MIC of thiabendazole against M. pachydermatis ranged from 0.03 to > 4 µg/mL. A total of 13.7% of the isolates were found to be resistant, 47.1% were intermediate and 39.2% were sensitive to the drug. The rate of resistance of the yeasts against thiabendazole was similar to the results previously obtained with other antifungals, while the adapted broth microdilution technique used in this study proved to be efficient. PMID:24031347

  5. Susceptibility testing of slowly growing mycobacteria by a microdilution MIC method with 7H9 broth.

    OpenAIRE

    Wallace, R J; Nash, D R; Steele, L C; Steingrube, V

    1986-01-01

    Based on previous success with rapidly growing mycobacteria, a microdilution MIC system was devised for slowly growing mycobacterial species using 7H9 broth. Test drugs included isoniazid, rifampin, ethambutol, streptomycin, clofazamine, and sulfamethoxazole. Sixty isolates of four mycobacterial species, including Mycobacterium tuberculosis, from patients who had never received drug therapy were evaluated in the system, as well as 25 drug-resistant isolates and 11 control strains. MICs were r...

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

    Directory of Open Access Journals (Sweden)

    Mahmoudi Rad M

    2010-02-01

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

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

    OpenAIRE

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

    1998-01-01

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

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

    Science.gov (United States)

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

    2008-10-01

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

  9. In vitro antibiotic susceptibilities of Burkholderia mallei (causative agent of glanders) determined by broth microdilution and E-test.

    Science.gov (United States)

    Heine, H S; England, M J; Waag, D M; Byrne, W R

    2001-07-01

    In vitro susceptibilities to 28 antibiotics were determined for 11 strains of Burkholderia mallei by the broth microdilution method. The B. mallei strains demonstrated susceptibility to aminoglycosides, macrolides, quinolones, doxycycline, piperacillin, ceftazidime, and imipenem. For comparison and evaluation, 17 antibiotic susceptibilities were also determined by the E-test. E-test values were always lower than the broth dilution values. Establishing and comparing antibiotic susceptibilities of specific B. mallei strains will provide reference information for assessing new antibiotic agents.

  10. Broth Microdilution Method To Detect Extended-Spectrum β-Lactamases and AmpC β-Lactamases in Enterobacteriaceae Isolates by Use of Clavulanic Acid and Boronic Acid as Inhibitors ▿

    Science.gov (United States)

    Jeong, Seok Hoon; Song, Wonkeun; Kim, Jae-Seok; Kim, Han-Sung; Lee, Kyu Man

    2009-01-01

    This study was designed to evaluate the performance of the broth microdilution (BMD) method to detect production of extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases in Enterobacteriaceae by using clavulanic acid (CA) and boronic acid (BA) as ESBL and AmpC β-lactamase inhibitors, respectively. A total of 100 clinical isolates of Enterobacteriaceae were analyzed. Mueller-Hinton broth containing serial twofold dilutions of cefotaxime (CTX), ceftazidime (CAZ), aztreonam (ATM), or cefepime (FEP) with or without either or both CA and BA was prepared. An eightfold or greater decrease in the MIC of CTX, CAZ, ATM, or FEP in the presence of CA and BA was considered a positive result for ESBL and plasmid-mediated AmpC β-lactamase (PABL), respectively. In tests with CA, expanded-spectrum β-lactams containing BA (CTX-BA, CAZ-BA, ATM-BA, and FEP-BA) showed higher positive rates in detecting ESBL producers than those without BA. The combination of CTX- and CAZ-based BMD tests with CA and BA showed sensitivity and specificity of 100% for the detection of ESBLs and PABLs. The BMD testing could be applicable for routine use in commercially available semiautomated systems for the detection of ESBLs and PABLs in Enterobacteriaceae. PMID:19710269

  11. 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

  12. 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)

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

    2015-01-01

    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. PMID:26438489

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

    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. PMID:22442324

  14. 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 susc

  15. Multicenter comparative evaluation of six commercial systems and the national committee for clinical laboratory standards m27-a broth microdilution method for fluconazole susceptibility testing of Candida species.

    Science.gov (United States)

    Morace, G; Amato, G; Bistoni, F; Fadda, G; Marone, P; Montagna, M T; Oliveri, S; Polonelli, L; Rigoli, R; Mancuso, I; La Face, S; Masucci, L; Romano, L; Napoli, C; Tatò, D; Buscema, M G; Belli, C M C; Piccirillo, M M; Conti, S; Covan, S; Fanti, F; Cavanna, C; D'Alò, F; Pitzurra, L

    2002-08-01

    Fluconazole susceptibility among 800 clinical Candida isolates (60% C. albicans) and two control strains (C. krusei ATCC 6258 and C. parapsilosis ATCC 22019) was tested with the NCCLS M27-A method (gold standard) and six commercial products (Candifast, disk, Etest, Fungitest, Integral System Yeasts, and Sensititre YeastOne). Results were classified as susceptible, susceptible-dose dependent, or resistant using M27-A breakpoints or, for Fungitest, Integral System Yeasts, and Candifast, as susceptible, intermediate, or resistant, according to the manufacturers' instructions. Concordance with NCCLS M27-A results was analyzed with the chi(2) test. Intra- and interlaboratory reproducibility was also evaluated. NCCLS M27-A (90.1%), Etest (93.1%), Sensititre YeastOne (93.1%), disk (96.7%), Fungitest (92.6%), Integral System Yeasts (40.6%), and Candifast (6.0%) classified the indicated percentages of C. albicans isolates as susceptible. Among non-C. albicans strains, the percentages of susceptible isolates were as follows: NCCLS M27-A, 74.0%; Etest, 83.8%; Sensititre YeastOne, 64.1%; disk, 60.6%; Fungitest, 76.6%; Integral System Yeasts, 28.3%; and Candifast, 27.4%. All methods except Candifast and Integral System Yeasts showed good agreement with NCCLS M27-A results for both C albicans and non-C. albicans isolates. Intralaboratory reproducibility was excellent for NCCLS M27-A, Etest, Sensititre YeastOne, disk, and Fungitest (88 to 91%). Similar results emerged from the interlaboratory reproducibility evaluation. Our findings indicate that some commercial methods can be useful for fluconazole susceptibility testing of clinical Candida isolates. Those characterized by a lack of medium standardization and/or objective interpretative criteria should be avoided. Particular caution is necessary when testing is being done for clinical and epidemiological purposes. PMID:12149358

  16. CLSI broth microdilution method for testing susceptibility of Malasseziapachydermatis to thiabendazole CLSI método de Microdiluição em Caldo para teste de suscetibilidade da Malassezia pachydermatis frente ao tiabendazol

    Directory of Open Access Journals (Sweden)

    Patrícia da Silva Nascente

    2009-06-01

    Full Text Available Thiabendazole, classified as antiparasitic and also used as an antifungal drug, can be found as otological solution indicated for treatment of parasitic and fungal external otitis in small animals. Malassezia pachydermatis is a yeast recognized as a normal inhabitant on the skin and mucous membranes of dogs and cats. However, it is considered an opportunistic agent that causes external otitis and dermatitis in these animals. The aim of this study was to evaluate the in vitro effect of thiabendazole against 51 isolates of M. pachydermatis using the CLSI Broth Microdilution method that has been adapted for this yeast species (NCCLS, 2002. Based on this test, the Minimum Inhibitory Concentrations (MIC of thiabendazol was calculated. Subsequently, the susceptibility of each isolate against this antifungal was determined. It was observed that the MIC of thiabendazole against M. pachydermatis ranged from 0.03 to > 4 μg/mL. A total of 13.7% of the isolates were found to be resistant, 47.1% were intermediate and 39.2% were sensitive to the drug. The rate of resistance of the yeasts against thiabendazole was similar to the results previously obtained with other antifungals, while the adapted broth microdilution technique used in this study proved to be efficient.Tiabendazol, um fármaco classificado como antiparasitário e também usado como antifúngico, pode ser encontrado como solução otologica indicada no tratamento da otite externa parasitária e fungica em pequenos animais. Malassezia pachydermatis é uma levedura considerada habitante normal da pele e das mucosas de cães e gatos. Entretanto, considera-se um agente do oportunista causador de otite externa e dermatite nestes animais. A finalidade deste estudo foi avaliar o efeito in vitro do tiabendazol frente a 51 amostras de M. pachydermatis através do método CLSI de Microdiluição em Caldo adaptado para esta espécie de levedura (NCCLS, 2002. Baseado neste teste calculou-se as Concentra

  17. 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 res

  18. 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. PMID:27053677

  19. 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.

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

    Science.gov (United States)

    Mayrhofer, Sigrid; van Hoek, Angela H A M; Mair, Christiane; Huys, Geert; Aarts, Henk J M; Kneifel, Wolfgang; Domig, Konrad J

    2010-11-15

    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 responsible for the displayed resistant phenotypes in a selection of strains. In general, narrow as well as broad unimodal and bimodal MIC distributions were observed for the Lactobacillus acidophilus group and the tested antimicrobial agents. Atypically resistant strains could be determined by visual inspection of the obtained MIC ranges for ampicillin, chloramphenicol, clindamycin, erythromycin, quinupristin/dalfopristin, streptomycin and tetracycline. For most of these atypically resistant strains underlying resistance determinants were found. To our knowledge erm(A) was detected in lactobacilli for the first time within this study. Data derived from this study can be used as a basis for reviewing present microbiological breakpoints for categorization of susceptible and resistant strains within the Lactobacillus acidophilus group to assess the safety of microorganisms intended for use in food and feed applications. PMID:20888656

  1. 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.

  2. 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

    Directory of Open Access Journals (Sweden)

    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.

  3. In Vitro Antifungal Susceptibility of Yeast Phase of Sporothrix schenckii by Microdilution Broth Method%微量稀释法检测申克孢子丝菌酵母相体外抗真菌药物敏感性

    Institute of Scientific and Technical Information of China (English)

    蔡晴; 李珊山; 宋洋; 沈永年; 吕桂霞; 陈伟; 刘维达

    2011-01-01

    Objective To evaluate the activities of potassium iodide, fluconazole, itraconazole, terbinafine on yeast phase of Sporothrix shenckii, and investigate the effect of potassium iodide on itraconazole and terbinafine by microdilution broth method in vitro. Methods Fifty-four isolates of Sporothrix shenckii were converted to the yeast form successive passages on Brain Heart Infusion Agar medium at 35℃. Then according to a modified CLSI microdilution method M27-A2, tested the susceptibility of these isolates to potassium iodide, fluconazole, itraconazole, terbinafine. We added potassium iodide in RPMI-1640, then compared the susceptibility of itraconazole and terbinafine with the former in vitro. Candida krusei ATCC 6258 was used for quality control. Results Potassium iodide showed no antifungal activity in vitro. Terbinafine had the best susceptibility, with geometric mean of 0. 17μg/mL, MIC range is 0.03 ~ 1 μg/mL. The MIC of itraconazole is 0.03 ~8μg/mL(0. 98μg/mL). Fluconazole has a high MIC( >64μg/mL). With potassium iodide in RPMI1640, the MICs of terbinafine and itraconazole were significantly different from the former results ( P <0. 05). But there were no significant difference in MIC between isolates from cutaneous sporotrichosis and lymphocutaneous sporotrichosis (P > 0.05). Conclusion A modified M27-A2 is an alternative method for testing yeast phase of Sporothrix schenckii. Potassium iodide can improve the antifungal susceptibility of terbinafine and itraconazole to yeast phase in vitro.%目的 用液基微量稀释法观察双相真菌申克孢子丝菌酵母相体外抗真菌药物敏感性.方法 将54株申克孢子丝菌临床株于脑心浸液琼脂培养基连续传代获得酵母相,参考美国临床实验室标准化委员会(CLSI)的微量稀释法M27-A2检测菌株酵母相对碘化钾、氟康唑、伊曲康唑和特比萘芬的体外敏感性,并观察碘化钾对伊曲康唑和特比萘芬体外抑菌作用的影响.

  4. 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

    salmonicida subsp. salmonicida ATCC 33658 against 10 antimicrobials (ampicillin, enrofloxacin, erythromycin, florfenicol, flumequine, gentamicin, ormetoprim/sulfadimethoxine, oxolinic acid, oxytetracycline, and trimethoprim/sulfamethoxazole) in diluted (4 g l−1) cation-adjusted Mueller-Hinton broth incubated...

  5. [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. PMID:26620604

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

    Directory of Open Access Journals (Sweden)

    Cristiane Yumi Koga-Ito

    2008-02-01

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

  7. 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. PMID:22471886

  8. 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

    2016-10-01

    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. PMID:27391222

  9. Comparison of microdilution broth and disk diffusion for antifungal susceptibility testing against Candida spp. Comparação entre microdiluição e disco difusão para o teste de susceptibilidade aos antifúngicos contra Candida spp.

    Directory of Open Access Journals (Sweden)

    Carlla Lorena Façanha Silva

    2012-06-01

    Full Text Available The evolution of fungal resistance can be evaluated by testing susceptibility to antifungal agents. The protocols for susceptibility testing most common are Broth Microdilution (BMD, Disk Diffusion (DD and E-test. The objective of this study was to compare the susceptibility tests conducted by the BMD and DD methods for amphotericin B and fluconazole against Candida spp. isolated in Fortaleza/CE. Were used 40 C. albicans, 50 C. tropicalis and 47 C. parapsilosis isolated from blood and urine samples of patients treated at Fortaleza General Hospital. The tests were conducted by the BMD and DD methods according to protocols M27-A3 and M44-A2 of the CLSI. These methods were compared and the percentages of agreement were calculated. For amphotericin B and fluconazole was a predominance of strains with reduced susceptibility. The percentage of agreement for the methods tested was above 97%. No serious errors were detected. The use of DD for performing antifungal susceptibility testing can be applied in routine laboratory tests, since one technique is easy, inexpensive, and reliable when compared to the BMD without compromising the results for the strains of C. albicans, C. tropicalis and C. parapsilosis.A evolução da resistência fúngica pode ser avaliada pelo teste de susceptibilidade aos antifúngicos. Os protocolos mais utilizados para testes de susceptibilidade são a micro diluição em caldo (MDC, disco difusão (DD e E-test. O objetivo principal deste estudo foi comparar os testes de sensibilidade realizados pelos métodos de MDC e DD para a anfotericina B e o fluconazol contra cepas de Candida spp. isoladas em Fortaleza/CE. Foram utilizadas 40 C. albicans, 50 C. tropicalis e 47 C. parapsilosis, isoladas de amostras de sangue e urina de pacientes atendidos no Hospital Geral de Fortaleza. Os testes foram realizados pelos métodos MDC e DD, de acordo com os protocolos M27-A3 e M44-A2 do CLSI. As metodologias foram comparadas e calculadas os

  10. A simple broth-disk method to determine the minimum inhibitory concentration of ceftriaxone on Salmonella enterica serovar typhi and paratyphi

    Directory of Open Access Journals (Sweden)

    Bhat K

    2009-04-01

    Full Text Available Background and Purpose: Resistance to fluoroquinolones and cephalosporins is a major problem with Salmonella enterica serovar Typhi and Paratyphi. An accurate determination of antibiotic susceptibility requires tests for minimum inhibitory concentration (MIC of antibiotics. We describe a simple broth-disk method to determine the MIC of ceftriaxone on S. typhi and S. paratyphi . Materials and Methods: Sixteen strains of S. typhi and two strains each of S. paratyphi A and S. paratyphi B were used in the study. The MIC of ceftriaxone was determined using the simple broth-disk method and the conventional broth macrodilution method and the results were compared. Results: All salmonella strains were susceptible to ceftriaxone. The results of the broth-disk and the conventional broth macrodilution method were similar. Conclusion: The broth-disk method is a simple, reliable and cost-effective method to determine the MIC of ceftriaxone on S. typhi and S. paratyphi A.

  11. Validation of a HILIC Method for the Analysis of Ergothioneine in Fermentation Broth.

    Science.gov (United States)

    Liu, Qi; Zhang, Weiya; Wang, Hongyu; Li, Yunhua; Liu, Wei; Wang, Qunjie; Liu, Dongze; Chen, Ning; Jiang, Wenxia

    2016-07-01

    A hydrophilic interaction liquid chromatography method has been established for the quantification of ergothioneine (EGT) in fermentation broth. Chromatographic separation was conducted on a Venusil hydrophilic interaction liquid chromatography (HILIC) column (250 × 4.6 mm, 5 µm) at an elution rate of 1.0 mL/min with an isocratic mobile phase consisting of acetonitrile/20 mmol/L ammonium acetate solution (85 : 15, v/v) adjusted to pH 6.0 with acetic acid. Analytes were detected at 254 nm using a UV-VIS detector. The injection volume was 10 µL, and the column temperature was 40°C. The limits of detection and limits of quantification were 63 and 21 µg/L, respectively. Excellent linearity [correlation coefficient (R(2)) = 0.9999] was achieved for EGT quantification in the range of 5-400 mg/L. The relative standard deviations of repeatability, intermediate precision and stability were 1.47, 1.03 and 1.66%, respectively, and EGT recoveries were within 99.2-100.8%. The chromatographic peak corresponding to EGT in the HILIC spectrum was confirmed using ESI-MS. In general, the method developed here is simple, reliable, accurate, and stable and may be useful for routine analyses in EGT biosynthesis research. PMID:26921894

  12. An improved HPLC-DAD method for clavulanic acid quantification in fermentation broths of Streptomyces clavuligerus.

    Science.gov (United States)

    Ramirez-Malule, Howard; Junne, Stefan; López, Carlos; Zapata, Julian; Sáez, Alex; Neubauer, Peter; Rios-Estepa, Rigoberto

    2016-02-20

    Clavulanic acid (CA) is an important secondary metabolite commercially produced by cultivation of Streptomyces clavuligerus (Sc). It is a potent inhibitor of bacterial β-lactamases. In this work, a specific and improved high performance liquid chromatography (HPLC) method, using a C-18 reversed phase column, diode array detector and gradient elution for CA quantification in fermentation broths of Sc, was developed and successfully validated. Samples were imidazole-derivatized for the purpose of creating a stable chromophore (clavulanate-imidazole). The calibration curve was linear over a typical range of CA concentration between 0.2 and 400mg/L. The detection and quantification limits were 0.01 and 0.02mg/L, respectively. The precision of the method was evaluated for CA spiked into production media and a recovery of 103.8%, on average, was obtained. The clavulanate-imidazole complex was not stable when the samples were not cooled during the analysis. The recovery rate was 39.3% on average. This assay was successfully tested for CA quantification in samples from Sc fermentation, using both, a chemically defined and a complex medium.

  13. EXTRACTION OF CITRIC ACID FROM FERMENTATION BROTH USING ION—EXCHANGE METHOD

    Institute of Scientific and Technical Information of China (English)

    LiuZuozhen; WangXiangyang; 等

    1998-01-01

    A number of ion-exchange resins were tested on their capacity to adsorb citric acid,among them resin 335,d315, Amberlite IRA-35 and IRA-68 exhibited higher adsorption capacity.We chose resin 335 and D315 to be used for extraction of citric acid from fermentation broth,followed by elution with 10% ammonia liquor,decoloration with K-15 carbon and removal of ammonia with resin 732,converting citrate of free citric acid with a concentration of 10% and an amount of readily carbonizable substance meeting the GB 8269-87 standard.

  14. Indirect methods for characterization of carbon dioxide levels in fermentation broth.

    Science.gov (United States)

    Frick, R; Junker, B

    1999-01-01

    Various factors which influence dissolved carbon dioxide levels were indirectly evaluated in pilot scale and laboratory studies. For pilot scale studies, off-gas carbon dioxide (percentage in exit air) was measured using a mass spectrometer and then its potential impact on dissolved carbon dioxide concentrations qualitatively examined. Greater volumetric air flowrates reduced off-gas carbon dioxide levels more effectively at lower airflow ranges and thus lowered expected dissolved carbon dioxide levels through gas stripping. Lower broth pH values decreased off-gas carbon dioxide levels but increased expected dissolved carbon dioxide levels due to the pH-dependence of the gas/liquid carbon dioxide equilibrium. While back-pressure increases had an insignificant effect on off-gas carbon dioxide levels, they directly affected expected dissolved carbon dioxide levels according to Henry's law. Laboratory studies, conducted using both uninoculated and inoculated fermentation media, quantified the response of the media to pH changes with bicarbonate addition, specifically its buffering capacity. This effect then was related qualitatively to expected dissolved carbon dioxide levels. Higher dissolved carbon dioxide levels, as demonstrated by reduced pH changes with bicarbonate addition, thus would be expected for salt solutions of increased ionic strength and higher protein content media. In addition, pH changes with greater bicarbonate additions declined for fermentation samples taken over the course of a one week cultivation, most likely due to the higher protein content associated with biomass growth. The presence of weak acids/bases initially in the media or formed as metabolic by products, as well as the concentration of buffering ions such as phosphate, also were believed to be important contributing elements to the buffering capacity of the solution. PMID:16232479

  15. 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.

  16. 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 laboratori

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

    OpenAIRE

    Sufian Soaib, M.; Sabet, M; 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...

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

    Directory of Open Access Journals (Sweden)

    SILVA Maria do Rosário R.

    2002-01-01

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

  19. Diagnostic Algorithm Using a Sensitive Broth Culture Method for Detection of Clostridium difficile Toxin from Stool Samples

    Directory of Open Access Journals (Sweden)

    Paul Bayardelle

    2009-01-01

    Full Text Available BACKGROUND: The two-step glutamate dehydrogenase antigencytotoxicity neutralization assay algorithm has been found to be reliable for the diagnosis of toxigenic Clostridium difficile. However, the high sensitivity of the screening method is compromised by the relative low sensitivity of the second step, the direct cytotoxin neutralization assay (DCNA using a fecal filtrate. The objective of the present study was to compare the DCNA with an indirect cytotoxin neutralization assay (ICNA.

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

    OpenAIRE

    Sidhartha Giri; Anupma Jyoti Kindo

    2014-01-01

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

  1. 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

  2. Evaluation of the Etest Method for Determining Fluconazole Susceptibilities of 402 Clinical Yeast Isolates by Using Three Different Agar Media

    OpenAIRE

    Pfaller, M A; Messer, S. A.; Karlsson, Å.; Bolmström, A.

    1998-01-01

    The performance of the Etest for fluconazole susceptibility testing of 402 yeast isolates was assessed against the National Committee for Clinical Laboratory Standards (NCCLS) microdilution broth method. The NCCLS method employed RPMI 1640 broth medium, and MICs were read after incubation for 48 h at 35°C. Etest MICs were determined with RPMI agar containing 2% glucose (RPG), Casitone agar (CAS), and Mueller-Hinton agar (MHA) and were read after incubation for 48 h at 35°C. The yeast isolates...

  3. Evaluation of Etest Method for Determining Caspofungin (MK-0991) Susceptibilities of 726 Clinical Isolates of Candida Species

    OpenAIRE

    Pfaller, M A; Messer, S. A.; Mills, K.; Bolmström, A.; Jones, R N

    2001-01-01

    The performance of the Etest for testing the susceptibilities to caspofungin (MK-0991) of 726 isolates of Candida spp. was assessed against the National Committee for Clinical Laboratory Standards (NCCLS) microdilution broth method. The NCCLS method employed RPMI 1640 broth medium, and MICs were read after incubation for 48 h at 35°C. MICs were determined by Etest for all 726 isolates with RPMI agar containing 2% glucose (RPG) and were read after incubation for 48 h at 35°C. The Candida isola...

  4. Fermented Broth in Tyrosinase- and Melanogenesis Inhibition

    Directory of Open Access Journals (Sweden)

    Chin-Feng Chan

    2014-08-01

    Full Text Available Fermented broth has a long history of applications in the food, pharmaceutical and cosmetic industries. Recently, the use of fermented broth in skin care products is in ascendance. This review investigates the efficacy of fermented broth in inhibiting tyrosinase and melanogenesis. Possible active ingredients and hypopigmentation mechanisms of fermented broth are discussed, and potential applications of fermented broth in the cosmetic industry are also addressed.

  5. Evaluation and comparison of SYBR Green I Real-Time PCR and TaqMan Real-Time PCR methods for quantitative assay of Listeria monocytogenes in nutrient broth and milk

    OpenAIRE

    Karatzas, Kimon Andreas G.

    2012-01-01

    Specific traditional plate count method and real-time PCR systems based on SYBR Green I and TaqMan technologies using a specific primer pair and probe for amplification of iap-gene were used for quantitative assay of Listeria monocytogenes in seven decimal serial dilution series of nutrient broth and milk samples containing 1.58 to 1.58×107 cfu /ml and the real-time PCR methods were compared with the plate count method with respect to accuracy and sensitivity. In this study, the plate count m...

  6. 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. PMID:24284936

  7. Recovery of succinic acid from fermentation broth.

    Science.gov (United States)

    Kurzrock, Tanja; Weuster-Botz, Dirk

    2010-03-01

    Succinic acid is of high interest as bio-feedstock for the chemical industry. It is a precursor for a variety of many other chemicals, e.g. 1,4-butandiol, tetrahydrofuran, biodegradable polymers and fumaric acid. Besides optimized production strains and fermentation processes it is indispensable to develop cost-saving and energy-effective downstream processes to compete with the current petrochemical production process. Various methods such as precipitation, sorption and ion exchange, electrodialysis, and liquid-liquid extraction have been investigated for the recovery of succinic acid from fermentation broth and are reviewed critically here. PMID:19898782

  8. 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.

  9. In vitro antimicrobial activity of benzoyl peroxide against Propionibacterium acnes assessed by a novel susceptibility testing method.

    Science.gov (United States)

    Okamoto, Kazuaki; Ikeda, Fumiaki; Kanayama, Shoji; Nakajima, Akiko; Matsumoto, Tatsumi; Ishii, Ritsuko; Umehara, Masatoshi; Gotoh, Naomasa; Hayashi, Naoki; Iyoda, Takako; Matsuzaki, Kaoru; Matsumoto, Satoru; Kawashima, Makoto

    2016-06-01

    Benzoyl peroxide (BPO), a therapeutic agent for acne vulgaris, was assessed for in vitro antimicrobial activity against Propionibacterium acnes using a novel broth microdilution testing that improved BPO solubility. We searched for a suitable culture medium to measure the minimum inhibitory concentration (MIC) of BPO against P. acnes and finally found the Gifu anaerobic medium (GAM) broth supplemented with 0.1(v/v)% glycerol and 2(v/v)% Tween 80, in which BPO dissolved up to 1250 μg/mL and P. acnes grew well. The MICs and minimum bactericidal concentrations (MBCs) of BPO against 44 clinical isolates of P. acnes collected from Japanese patients with acne vulgaris were determined by our testing method using the supplemented GAM broth. The MICs of BPO were 128 or 256 μg/mL against all isolates of P. acnes regardless of susceptibility to nadifloxacin or clindamycin. The MBCs of BPO were also 128 or 256 μg/mL against the same isolates. Moreover, BPO at the MIC showed a rapid bactericidal activity against P. acnes ATCC11827 in time-kill assay. In conclusion, we could develop a novel assay for the MIC and MBC determinations of BPO against P. acnes, which is reliable and reproducible as a broth microdilution testing and the present results suggest that BPO has a potent bactericidal activity against P. acnes.

  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. 刚果红法测定乳酸发酵液中的β-葡聚糖类物质%Determination of β-glucan substances in L-lactic acid fermentation broth by Congo red method

    Institute of Scientific and Technical Information of China (English)

    韩玉杰; 马建卢; 寇永磊; 樊伟丽; 常文耀; 吴健

    2011-01-01

    在利用凝结芽孢杆菌(Bacillus coagulans)进行以葡萄糖为基质的乳酸发酵过程中通过外加商品纤维素酶可以显著增加乳酸产量。为探讨其中原因,用羧甲基纤维素(CMC)作为β-葡聚糖标品,建立了刚果红分光光度法测定乳酸发酵提取液中β-葡聚糖的稳定体系,用以测定乳酸发酵液中的β-葡聚糖含量。实验证明当Na+浓度为0.025~0.175mol/L,Ca2+浓度为0.001~0.005mol/L,蛋白质质量浓度为0~40mg/L时,这几种杂质对β-葡聚糖测定的干扰可以忽略。刚果红法测定β-葡聚糖的最佳条件为:最大吸收波长550nm、pH8.0磷酸缓冲液、测定时间15min。实验结果显示乳酸发酵液中β-葡聚糖含量很低,纤维素酶水解发酵液中的β-葡聚糖类物质不足于显著增加乳酸产量,其增产作用一定另有原因。%In the process of L-lactic acid fermentation by Bacillus coagulans using glucose as the feedstock,the yield of L-lactic acid could be increased through adding cellulases.To investigate the reason,a stable system of spectrophotometric determination of β-glucan substance was established to measure the content of β-glucan substance in the L-lactic acid fermentation broth,using carboxymethyl cellulose(CMC) as the standard substance of β-glucan.It was illustrated that the potential influence might be omitted when the concentration of sodium ions in 0.025~0.175 mol/L,calcium ions in 0.001~0.005 mol/L,and the concentration of proteins in 0~40 mg/L.The optimal condition for determination by Congo red method is the maximum absorption wavelength 550 nm,pH 8.0 with phosphate buffer and the reaction time 15 minutes.The experiments reveal that the content of β-glucan substance in L-lactic acid fermentation broth is rather low,and the reason why cellulases could enhance the yield of L-lactic acid needs further investigation.

  12. Separating Kanamycin A And B From The Fermentation Broth

    Institute of Scientific and Technical Information of China (English)

    LI Zhongqin; Xuefengchun; Xu Xiaoping; Guo Yanghao

    2004-01-01

    A method to separate Kanamycin A and B from their fermentation broth is proposed in this paper. In order to seek Kanamycin B-sensitive resin, the equilibrium constants of Kanamycin B were estimated by potentiometric titration, and then the resins for test were evaluted by static and dynamicabsorption. The results indicated that the D4 with larger mesh has higher adsorption rate of Kanamycin B and lower adsorption amount of impurity. Using D4 as first column and 732# as late binding columns, the purity of Kanamycin A is higher than 99.0%.

  13. 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.

  14. Viability of Escherichia coli ATCC 8739 in Nutrient Broth, Luria-Bertani Broth and Brain Heart Infusion over 11 Weeks

    Directory of Open Access Journals (Sweden)

    Chin How Lee

    2013-01-01

    Full Text Available Abstract:Background: Escherichia coli is a widely studied prokaryotic system. A recent study had demonstrated that reduced growth of E. coli after extended culture in Luria-Bertani broth is a result of depletion of fermentable sugars but able to sustain extended cell culture due to the presence of amino acids, which can be utilized as a carbon source. However, this had not been demonstrated in other media. The study aimed to determine the growth and viability of E. coli ATCC 8739 in 3 different media, Nutrient Broth (NB, Brain Heart Infusion (BHI and Luria-Bertani Broth (LB over 11 weeks.Methods: Growth of E. coli ATCC 8739 was determined by optical density. Viability was determined by serial dilution/spread-plate enumeration. After 11 weeks, the media were exhausted by repeated culture. Glucose was added to the exhausted media to determine whether glucose is the growth-limiting factor.Results: Our results showed that cell density in all 3 media increased to about 1 x 109 cells/ml by the end of week 1, from the inoculation density of 2.67 x 105 cells/ml, peaked at about 1 x 1013 cells/ml at week 4, before declining to about 5 x 107 cells/ml at week 7. Cell density is highly correlated to genomic DNA content (r2 = 0.93 but poorly correlated to optical density (r2< 0.2. Our results also showed that the spent media were able to support further growth after glucose-supplementation.Conclusion: NB, LB and BHI are able to support extended periods of culture and glucose depletion is the likely reason for declining cell growth.

  15. βlasEN: Microdilution Panel for Identifying β-Lactamases Present in Isolates of Enterobacteriaceae

    OpenAIRE

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

    2002-01-01

    A dried investigational use-only microdilution panel named βlasEN (a short named derived from the panel’s purpose, to identify β-lactamases in Enterobacteriaceae) containing 10 β-lactam drugs with and without β-lactamase inhibitors was developed to identify β-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 org...

  16. 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. PMID:23375414

  17. Filtration Process of the Spiramycin Fermentation Broth

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    This paper presents the effects of acidity and additive pretreatment on the filtering rate and Spiramycin (SPM) concentration in the filter liquor of SPM fermentation broth. The experimental results show that the SPM peak value in filter liquor is obtained at pH 5.5 with either 0.1% methanal or 0.1% BAPE. It is also indicated that there exists a dissolution equilibrium of proteins from the experiment results. The soluble proteins are denatured due to the too high/low acidity and then precipitate. Usually, the amount of soluble proteins reaches its lowest level in pH range of 6.0-6.5. The protein precipitation will, together with other suspended solids particles, contribute to the final SPM concentration in the filter liquor. This paper assumes that the contribution is the result of the adsorption equilibrium of SPM on the surfaces of suspended solids. For a satisfactory explanation, the revised Langmuir adsorption theory was employed and a model was developed.

  18. 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.

  19. Antibacterial effect of several extracts of Dictyophora indusiata to bacteria common in food determined by micro-broth dilution method%微量肉汤稀释法测定长裙竹荪多种提取物对食品中常见细菌的抑制效果

    Institute of Scientific and Technical Information of China (English)

    曹奕; 孙晓红; 陈燕; 赵勇; Vivian C H Wu; 潘迎捷

    2013-01-01

    Dictyophora indusiata was chosen as the sample, got the volatile oil with hydro-distillation after soxlet extracting,and the extracts extracted by ethanol.n-butanol and petroleum ether at the same time.With the micro broth dilution method,got the MIC values of all kinds of extracts to eight kinds of bacteria common in food,as the indicators to evaluate the antibacterial effect.Results showed that the antibacterial effect of volatile oils were better than three kinds of organic solvent extract in the culture medium. By comparison of results with colonial counting and research results of others at the same time,proving the micro broth dilution method as a determination method with feasibility and accuracy.%选取长裙竹荪为样品,采用索氏抽提后水蒸馏萃取获得挥发油,同时分别以乙醇、正丁醇、石油醚等有机溶剂萃取得到相应提取物.以8种食品中常见细菌为供试对象,由微量肉汤稀释法测得各类提取物对其的MIC值,作为评价其抑菌效果的指标结果表明:纯培养环境下,挥发油的抑菌效果优于三种有机溶剂提取物.通过与平板涂布计数结果及其它方法比较分析,进一步证明肉汤稀释法作为测定抑菌效果所具有的优越性.

  20. Early and Efficient Detection of Mycobacterium tuberculosis in Sputum by Microscopic Observation of Broth Cultures

    OpenAIRE

    Benson R Kidenya; Rodrick Kabangila; Peck, Robert N; Mshana, Stephen E; Webster, Lauren E.; Koenig, Serena P; Warren D Johnson; Fitzgerald, Daniel W.

    2013-01-01

    Early, efficient and inexpensive methods for the detection of pulmonary tuberculosis are urgently needed for effective patient management as well as to interrupt transmission. These methods to detect M. tuberculosis in a timely and affordable way are not yet widely available in resource-limited settings. In a developing-country setting, we prospectively evaluated two methods for culturing and detecting M. tuberculosis in sputum. Sputum samples were cultured in liquid assay (micro broth cultur...

  1. Cross-flow membrane microfiltration of a bacteriol fermentation broth.

    Science.gov (United States)

    Nagata, N; Herouvis, K J; Dziewulski, D M; Belfort, G

    1989-08-01

    Although cross-flow membrane filtration is a very attractive option for harvesting cells and recovering enzymes from cell homogenates, the process is not without its problems. Foremost of these is the deposit of dissolved and suspended solutes onto the membrane surface during operation. The formation of these dense and sometimes compressive sublayers (often called cakes) offers additional resistance to axial and permeate flows and often affects the retention characteristics of the process. In view of the complex nature of the sublayer formation process and its sensitivity to cross-flow velocity, this investigation was undertaken to determine the main factors responsible for the decline in performance during the harvesting of B. polymyxa broth by membrane microfiltration. System parameters varied include axial flow rate, concentration of cells, proteins and other components in the feed, membrane materials (ceramic, polypropylene, and stainless steel), and cleaning methods. To help explain the observed results, a new mass transport model-the solids flux model-based on the assumptions that back migration of particles from the sublayer or membrane surface is negligible and that particles that reach the solid-solution interface attach (stick) completely, is tested. Using a variety of diagnostic methods, magnesium ammonium phosphate precipitate is formed during steam sterilization of the medium and is implicated as the major foulant in this study. PMID:18588126

  2. Binding of Todd-Hewitt broth antigens by Streptococcus mutans.

    Science.gov (United States)

    Stinson, M W; Jones, C A

    1983-01-01

    Streptococcus mutans 10449, grown in chemically defined culture medium, was tested for its ability to bind 3H-labeled Todd-Hewitt broth components (greater than 12,000 Mr). Maximum adsorption of radioactivity occurred within 5 min at room temperature, and cell-bound material was not completely removed by extended washing with buffer. Heat-killed, arsenate-inhibited, and viable bacteria bound similar quantities. Only 0.09% of the radioactivity in the preparation of high Mr Todd-Hewitt broth components was removed by absorption with excess numbers of S. mutans 10449 cells. Binding followed saturation kinetics and was competitively inhibited by unlabeled medium components, both the dialyzable and nondialyzable fractions. Other oral streptococci were also found to bind these complex medium components. Rabbit antiserum elicited to the high-molecular-weight Todd-Hewitt broth components reacted with monkey cardiac muscle and with S. mutans coated with medium components. Absorption of the anti-Todd-Hewitt broth serum with homogenized heart removed antibodies that reacted with Todd-Hewitt broth-coated S. mutans. Therefore, the tissue-specific antigens of this beef heart infusion medium that adsorb to S. mutans can interfere with the detection and characterization of antigens shared by these bacteria and animal tissues. Images PMID:6852915

  3. 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.

  4. Early and efficient detection of Mycobacterium tuberculosis in sputum by microscopic observation of broth cultures.

    Directory of Open Access Journals (Sweden)

    Benson R Kidenya

    Full Text Available Early, efficient and inexpensive methods for the detection of pulmonary tuberculosis are urgently needed for effective patient management as well as to interrupt transmission. These methods to detect M. tuberculosis in a timely and affordable way are not yet widely available in resource-limited settings. In a developing-country setting, we prospectively evaluated two methods for culturing and detecting M. tuberculosis in sputum. Sputum samples were cultured in liquid assay (micro broth culture in microplate wells and growth was detected by microscopic observation, or in Löwenstein-Jensen (LJ solid media where growth was detected by visual inspection for colonies. Sputum samples were collected from 321 tuberculosis (TB suspects attending Bugando Medical Centre, in Mwanza, Tanzania, and were cultured in parallel. Pulmonary tuberculosis cases were diagnosed using the American Thoracic Society diagnostic standards. There were a total of 200 (62.3% pulmonary tuberculosis cases. Liquid assay with microscopic detection detected a significantly higher proportion of cases than LJ solid culture: 89.0% (95% confidence interval [CI], 84.7% to 93.3% versus 77.0% (95% CI, 71.2% to 82.8% (p = 0.0007. The median turn around time to diagnose tuberculosis was significantly shorter for micro broth culture than for the LJ solid culture, 9 days (interquartile range [IQR] 7-13, versus 21 days (IQR 14-28 (p<0.0001. The cost for micro broth culture (labor inclusive in our study was US $4.56 per sample, versus US $11.35 per sample for the LJ solid culture. The liquid assay (micro broth culture is an early, feasible, and inexpensive method for detection of pulmonary tuberculosis in resource limited settings.

  5. Determination of 2-amino-6-methylpyridine in Blakeslea trispora fermentation broth by HPLC-UV method%高效液相-紫外法检测三孢布拉霉菌发酵液中2-氨基-6-甲基吡啶

    Institute of Scientific and Technical Information of China (English)

    万红贵; 缪玲玲; 王文娟; 张波; 汪文进; 石楠

    2012-01-01

    A high performance liquid chromatography-ultraviolet spectrometry(HPLC-UV) method has been developed for determination of 2-amino-6-methylpyridine in Blakeslea trispora fermentation broth. 2-amino-6-methylpyridine and other relative impurities was achieved on a AIItima C18(250 mmx4.6 mm i.d., 5 IJm) by using methanol-water-l% aqueous acetic acid solution(85:10:5, v/v/v) as the mobile phase at a flow rate of 1.0 mL/min.Detection was operated by UV absorption at a wavelength of 231 nm. The calibration curves were showed good linearity(r2=0.9994) within the concentration range of 5.0-500 mg/ L for 2-amino-6-methylpyridine. The average recoveries were ranged from 99.76%~101.4%. And the standard deviation was less than 2.17%. The method was simple and accurate for the determination of 2-amino-6-methylpyridine in Blakeslea trispora fermentation broth.%建立高效液相色谱-紫外法对三孢布拉霉菌发酵液中2-氨基-6-甲基吡啶含量检测的方法。采用AlltimaC18(250mm×4.6mmi.d.,5μm)色谱柱,以甲醇:水:1%乙酸=85:10:5(v/v/v)为流动相,流速为1.0mL/min时,2-氨基-6-甲基吡啶及其他杂质得到良好分离,紫外光谱231nm检测。在该色谱条件下,2-氨基-6-甲基吡啶浓度5~500mg/L时,其峰面积与相应的浓度线性关系良好(R2=0.9994),回收率99.76%~101.4%,精密度RSD〈2.17%。该方法简便、快速、准确可靠,为三孢布拉霉菌发酵液中2-氨基-6-甲基吡啶的检测和含量控制提供了可靠的分析方法。

  6. 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. PMID:11773104

  7. 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.

  8. Filamentation of Campylobacter in broth cultures

    Directory of Open Access Journals (Sweden)

    Nacheervan M Ghaffar

    2015-06-01

    Full Text Available The transition from rod to filamentous cell morphology has been identified as a response to stressful conditions in many bacterial species and has been ascribed to confer certain survival advantages. Filamentation of Campylobacter jejuni was demonstrated to occur spontaneously on entry in to stationary phase distinguishing it from many other bacteria where a reduction in size is more common. The aim of this study was to investigate the cues that give rise to filamentation of C. jejuni and C. coli and gain insights into the process. Using minimal medium, augmentation of filamentation occurred and it was observed that this morphological change was wide spread amongst C. jejuni strains tested but was not universal in C. coli strains. Filamentation did not appear to be due to release of diffusible molecules, toxic metabolites, or be in response to oxidative stress in the medium. Separated filaments exhibited greater intracellular ATP contents (2.66 to 17.4 fg than spiral forms (0.99 to 1.7 fg and showed enhanced survival in water at 4oC and 37oC compared to spiral cells. These observations support the conclusion that the filaments are adapted to survive extra-intestinal environments. Differences in cell morphology and physiology need to be considered in the context of the design of experimental studies and the methods adopted for the isolation of campylobacters from food, clinical and environmental sources.

  9. Computing Method of Specific Resistances of Constant Pressure Filtrating Fermented Broth Based on MATLAB---Taking Bacillus amyloliquefaciens Q -426 as an Example%基于MATLAB的发酵液恒压过滤比阻计算方法--以解淀粉芽孢杆菌Q-426发酵液为例

    Institute of Scientific and Technical Information of China (English)

    刘俏; 刘涛; 杨薇

    2015-01-01

    介绍了用MATLAB的Curve Fitting Toolbox计算解淀粉芽孢杆菌Q-426发酵液恒压过滤比阻的方法。通过在图形界面下导入恒压过滤实验数据及平滑处理、采用平滑样条拟合数据以及数值微分等操作,确定了解淀粉芽孢杆菌Q-426发酵液恒压过滤的滤饼比阻。研究表明,该方法运行可靠,无需编程,易于掌握。与传统计算方法相比,操作更为便捷,强有力的图形界面也使计算变得更加简单而直观。%This paper presents a method to determine the cake specific resistances( CSR) for con-stant pressure filtrating fermented broth of Bacillus amyloliquefaciens Q–426 using MATLAB’ s Curve Fitting Toolbox. The acquired data was imported and smoothed via the graphical user in-terface ( GUI) . Smoothing spline was used to produce smooth curves to fit to the data, and the CSR was calculated by numerical differentiation. The study showed that the calculated results are accurate and reliable. Compared with the traditional calculations, this method provides visu-alized results, and the GUI simplifies the calculation and makes it intuitive. It can be easily mastered for those who are not adept programmers.

  10. 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.

  11. Background and Objective: Listeria monocytogenes is a bacterium transferred by foods and is the agent of many sporadic and epidemic diseases in humans. This study aimed to investigate the prevalence of L. monocytogenes and to determinine their antibiotic resistance profile in red meats. Material and Methods: this cross-sectional study was performed on 400 red meat samples obtained from industrial slaughterhouses placed in Kerman, Iran. First, the samples were enriched with Simultaneous Enrichment Broth (SEB, and then plated onto Palcam agar and Tryptic Soy Broth Yeast Extract Broth (TSAYE. After identification of the isolates based on biochemical tests and PCR, the isolates were checked for their antibiotic resistance profile using disk Diffusion Results: of 400 samples, 12 samples (3% were contaminated with different species of Listeria. Using PCR, hly gene was recognized in eight samples (2% of L. monocytogenes. Furthermore, there was a significant difference in isolation rate of lamb samples compared to cow ones. While all of the isolates were resistant to clindamycin, amikacin and chloramphenicol, they were sensitive to penicillin. Conclusion: in spite of low rate of infection in red meat samples in Kerman city, due to high risk of Listeria contamination in red meats, we recommend applying a routine screening to identify this bacterium in our county.

    Directory of Open Access Journals (Sweden)

    Kargar, M. (PhD

    2014-11-01

    Full Text Available Background and Objective: Listeria monocytogenes is a bacterium transferred by foods and is the agent of many sporadic and epidemic diseases in humans. This study aimed to investigate the prevalence of L. monocytogenes and to determinine their antibiotic resistance profile in red meats. Material and Methods: this cross-sectional study was performed on 400 red meat samples obtained from industrial slaughterhouses placed in Kerman, Iran. First, the samples were enriched with Simultaneous Enrichment Broth (SEB, and then plated onto Palcam agar and Tryptic Soy Broth Yeast Extract Broth (TSAYE. After identification of the isolates based on biochemical tests and PCR, the isolates were checked for their antibiotic resistance profile using disk Diffusion Results: of 400 samples, 12 samples (3% were contaminated with different species of Listeria. Using PCR, hly gene was recognized in eight samples (2% of L. monocytogenes. Furthermore, there was a significant difference in isolation rate of lamb samples compared to cow ones. While all of the isolates were resistant to clindamycin, amikacin and chloramphenicol, they were sensitive to penicillin. Conclusion: in spite of low rate of infection in red meat samples in Kerman city, due to high risk of Listeria contamination in red meats, we recommend applying a routine screening to identify this bacterium in our county

  12. Comparative evaluation of antibacterial activity of caffeic acid phenethyl ester and PLGA nanoparticle formulation by different methods

    Science.gov (United States)

    Arasoglu, Tülin; Derman, Serap; Mansuroglu, Banu

    2016-01-01

    The aim of the present study was to evaluate the antimicrobial activity of nanoparticle and free formulations of the CAPE compound using different methods and comparing the results in the literature for the first time. In parallel with this purpose, encapsulation of CAPE with the PLGA nanoparticle system (CAPE-PLGA-NPs) and characterization of nanoparticles were carried out. Afterwards, antimicrobial activity of free CAPE and CAPE-PLGA-NPs was determined using agar well diffusion, disk diffusion, broth microdilution and reduction percentage methods. P. aeroginosa, E. coli, S. aureus and methicillin-resistant S. aureus (MRSA) were chosen as model bacteria since they have different cell wall structures. CAPE-PLGA-NPs within the range of 214.0 ± 8.80 nm particle size and with an encapsulation efficiency of 91.59 ± 4.97% were prepared using the oil-in-water (o-w) single-emulsion solvent evaporation method. The microbiological results indicated that free CAPE did not have any antimicrobial activity in any of the applied methods whereas CAPE-PLGA-NPs had significant antimicrobial activity in both broth dilution and reduction percentage methods. CAPE-PLGA-NPs showed moderate antimicrobial activity against S. aureus and MRSA strains particularly in hourly measurements at 30.63 and 61.25 μg ml-1 concentrations (both p 0.05). In the reduction percentage method, in which the highest results of antimicrobial activity were obtained, it was observed that the antimicrobial effect on S. aureus was more long-standing (3 days) and higher in reduction percentage (over 90%). The appearance of antibacterial activity of CAPE-PLGA-NPs may be related to higher penetration into cells due to low solubility of free CAPE in the aqueous medium. Additionally, the biocompatible and biodegradable PLGA nanoparticles could be an alternative to solvents such as ethanol, methanol or DMSO. Consequently, obtained results show that the method of selection is extremely important and will influence the

  13. Broth medium for enrichment of Vibrio fluvialis from the environment.

    OpenAIRE

    Nishibuchi, M; Roberts, N C; Bradford, H B; Seidler, R J

    1983-01-01

    A medium was designed for the enrichment and enumeration of Vibrio fluvialis from environmental samples. The medium contains 1% peptone plus 4% sodium chloride and 5 micrograms of novobiocin per ml, pH 8.5. This V. fluvialis enrichment medium (FEM) was tested, in comparison with alkaline peptone (AP), in field samplings. A total of 177 samples (estuarine waters and sediment, sewage, and crabs) collected over a 14-month period were examined with FEM and with AP broth. Results showed that FEM w...

  14. Biodegradation of 1,2,3,4-tetrachlorodibenzo-p-dioxin in liquid broth by brown-rot fungi.

    Science.gov (United States)

    Perlatti, Bruno; da Silva, Maria Fátima das Graças Fernandes; Fernandes, João Batista; Forim, Moacir Rossi

    2013-11-01

    Dioxins are a class of extremely hazardous molecules that might pose a threat to the environment. This work evaluated the microbial degradation of 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD), in liquid broth using three brown-rot fungi and one white-rot fungi as control. A fast and reliable extraction method with recoveries of over 98% together with a validated GC-MS method was developed, and applied to quantify 1,2,3,4-TCDD in liquid broth, mycelia and reaction flask, with detection limits of 10 ppb. Among the four strains tested, brown-rot fungus Aspergillus aculeatus showed best results, removing up to 21% of dioxin after 30-day incubation. The results open both a path for biotechnological interest in bioremediation purposes and environmental behavior studies by using brown-rot fungus.

  15. 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.

  16. Optimization of the precipitation of clavulanic acid from fermented broth using t-octylamine as intermediate

    Directory of Open Access Journals (Sweden)

    D. B. Hirata

    2013-06-01

    Full Text Available This work describes the use of clavulanic acid (CA precipitation as the final step in the process of purification of CA from fermentation broth as an alternative to conventional methods employed traditionally. The purpose of this study was to use a stable intermediate (t-octylamine between the conversion of CA to its salt form (potassium clavulanate, thereby enabling the resulting intermediate (amine salt of clavulanic acid to improve the purification process and maintain the stability of the resulting potassium clavulanate. To this end, response surface methodology was employed to optimize the precipitation step. For the first reaction, five temperatures (6.6 to 23.4 ºC, concentrations of clavulanic acid in organic solvent (6.6 to 23.4 mg/mL and t-octylamine inflow rates (0.33 to 1.17 drop/min were selected based on a central composite rotatable design (CCRD. For the second reaction, five temperatures (11.6 to 28.4 ºC, concentrations of clavulanic acid amine salt in organic solvent (8.2 to 41.8 mg/mL and concentrations of potassium 2-ethylhexanoate (0.2 to 1.2 molar were also selected using CCRD. From these results, precipitation conditions were selected and applied to the purification of CA from the fermentation broth, obtaining a yield of 72.37%.

  17. 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...

  18. Effect of fermented broth from lactic acid bacteria on pathogenic bacteria proliferation.

    Science.gov (United States)

    Gutiérrez, S; Martínez-Blanco, H; Rodríguez-Aparicio, L B; Ferrero, M A

    2016-04-01

    In this study, the effect that 5 fermented broths of lactic acid bacteria (LAB) strains have on the viability or proliferation and adhesion of 7 potentially pathogenic microorganisms was tested. The fermented broth from Lactococcus lactis C660 had a growth inhibitory effect on Escherichia coli K92 that reached of 31%, 19% to Pseudomonas fluorescens, and 76% to Staphylococcus epidermidis. The growth of Staph. epidermidis was negatively affected to 90% by Lc. lactis 11454 broth, whereas the growth of P. fluorescens (25%) and both species of Staphylococcus (35% to Staphylococcus aureus and 76% to Staph. epidermidis) were inhibited when they were incubated in the presence of Lactobacillus casei 393 broth. Finally, the fermented broth of Lactobacillus rhamnosus showed an inhibitory effect on growth of E. coli K92, Listeria innocua, and Staph. epidermidis reached values of 12, 28, and 76%, respectively. Staphylococcus epidermidis was the most affected strain because the effect was detected from the early stages of growth and it was completely abolished. The results of bacterial adhesion revealed that broths from Lc. lactis strains, Lactobacillus paracasei, and Lb. rhamnosus caused a loss of E. coli K92 adhesion. Bacillus cereus showed a decreased of adhesion in the presence of the broths of Lc. lactis strains and Lb. paracasei. Listeria innocua adhesion inhibition was observed in the presence of Lb. paracasei broth, and the greatest inhibitory effect was registered when this pathogenic bacterium was incubated in presence of Lc. lactis 11454 broth. With respect to the 2 Pseudomonas, we observed a slight adhesion inhibition showed by Lactobacillus rhamnosus broth against Pseudomonas putida. These results confirm that the effect caused by the different LAB assayed is also broth- and species-specific and reveal that the broth from LAB tested can be used as functional bioactive compounds to regulate the adhesion and biofilm synthesis and ultimately lead to preventing food and

  19. Paradigm Diagnostics Salmonella Indicator Broth (PDX-SIB) for detection of Salmonella on selected environmental surfaces.

    Science.gov (United States)

    Olstein, Alan; Griffith, Leena; Feirtag, Joellen; Pearson, Nicole

    2013-01-01

    The Paradigm Diagnostics Salmonella Indicator Broth (PDX-SIB) is intended as a single-step selective enrichment indicator broth to be used as a simple screening test for the presence of Salmonella spp. in environmental samples. This method permits the end user to avoid multistep sample processing to identify presumptively positive samples, as exemplified by standard U.S. reference methods. PDX-SIB permits the outgrowth of Salmonella while inhibiting the growth of competitive Gram-negative and -positive microflora. Growth of Salmonella-positive cultures results in a visual color change of the medium from purple to yellow when the sample is grown at 37 +/- 1 degree C. Performance of PDX-SIB has been evaluated in five different categories: inclusivity-exclusivity, methods comparison, ruggedness, lot-to-lot variability, and shelf stability. The inclusivity panel included 100 different Salmonella serovars, 98 of which were SIB-positive during the 30 to 48 h incubation period. The exclusivity panel included 33 different non-Salmonella microorganisms, 31 of which were SIB-negative during the incubation period. Methods comparison studies included four different surfaces: S. Newport on plastic, S. Anatum on sealed concrete, S. Abaetetuba on ceramic tile, and S. Typhimurium in the presence of 1 log excess of Citrobacter freundii. Results of the methods comparison studies demonstrated no statistical difference between the SIB method and the U.S. Food and Drug Administration-Bacteriological Analytical Manual reference method, as measured by the Mantel-Haenszel Chi-square test. Ruggedness studies demonstrated little variation in test results when SIB incubation temperatures were varied over a 34-40 degrees C range. Lot-to-lot consistency results suggest no detectable differences in manufactured goods using two reference Salmonella serovars and one non-Salmonella microorganism.

  20. A selective broth enrichment combined with real-time nuc-mecA-PCR in the exclusion of MRSA.

    Science.gov (United States)

    Pasanen, Tanja; Korkeila, Maija; Mero, Sointu; Tarkka, Eveliina; Piiparinen, Heli; Vuopio-Varkila, Jaana; Vaara, Martti; Tissari, Päivi

    2010-01-01

    We analyzed the performance of a selective enrichment broth combined with Taqman-based real-time duplex nuc-mecA-PCR to expedite the screening of methicillin-resistant Staphylococcus aureus (MRSA). We found the broth to be able to select MRSA strains (oxacillin MIC range 4-256 microg/ml) from MSSA strains. A total of 31 MRSA strains were found from 1250 clinical samples screened. The nuc-mecA-PCR was positive from all enrichment broths containing MRSA. From the remaining 1219 samples negative for MRSA on culture/subculture, 138 samples were nuc+/mecA+ in PCR. The sensitivity of the test was 93.5%, specificity 88.6%, positive predictive value 17.3%, and negative predictive value 99.8% as compared to culture. Thus, with this method, the negative MRSA results can be reliably reported within 24-48 h from sampling. The method is a practical additional alternative to those already described for the same purpose.

  1. 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

  2. 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.

  3. Succinic acid adsorption from fermentation broth and regeneration.

    Science.gov (United States)

    Davison, Brian H; Nghiem, Nhuan P; Richardson, Gerald L

    2004-01-01

    More than 25 sorbents were tested for uptake of succinic acid from aqueous solutions. The best resins were then tested for successive loading and regeneration using hot water. The key desired properties for an ideal sorbent are high capacity, complete stable regenerability, and specificity for the product. The best resins have a stable capacity of about 0.06 g of succinic acid/g of resin at moderate concentrations (1-5 g/L) of succinic acid. Several sorbents were tested more exhaustively for uptake of succinic acid and for successive loading and regeneration using hot water. One resin, XUS 40285, has a good stable isotherm capacity, prefers succinate over glucose, and has good capacities at both acidic and neutral pH. Succinic acid was removed from simulated media containing salts, succinic acid, acetic acid, and sugar using a packed column of sorbent resin, XUS 40285. The fermentation byproduct, acetate, was completely separated from succinate. A simple hot water regeneration successfully concentrated succinate from 10 g/L (inlet) to 40-110 g/L in the effluent. If successful, this would lower separation costs by reducing the need for chemicals for the initial purification step. Despite promising initial results of good capacity (0.06 g of succinic/g of sorbent), 70% recovery using hot water, and a recovered concentration of >100 g/L, this regeneration was not stable over 10 cycles in the column. Alternative regeneration schemes using acid and base were examined. Two (XUS 40285 and XFS-40422) showed both good stable capacities for succinic acid over 10 cycles and >95% recovery in a batch operation using a modified extraction procedure combining acid and hot water washes. These resins showed comparable results with actual broth. PMID:15054284

  4. The distribution and synonyms of Breutelia microdonta (Mitt.) Broth. : with additional notes on certain taxa of Breutelia

    OpenAIRE

    Griffin, Dana

    1992-01-01

    Breutelia microdonta (Mitt.) Broth., described originally from Brazil, is the oldest name for a disjunct widespread tropical species that includes as synonyms B. angustifolia Rehm. ex Sim of Southern Africa and B. merrillii Broth. of the Philippines. Breutelia kilaueae (C. Muell.) Broth. of Hawaii is considered a synonym of the austral Pacific species B. affinis (Hook.) Mitt., and B. brachyphylla Broth. of Ecuador is reduced to synonymy under the North Andean B. squarrosa Jaeg. Breutelia anac...

  5. In vitro Activity of Celery Essential Oil against Malassezia furfur

    OpenAIRE

    Chee, Hee Youn; Lee, Min Hee

    2009-01-01

    Antifungal activity of celery essential oil against Malassezia furfur was investigated using broth microdilution and vapor contact methods. Potent antifungal activity was evident using both methods. Fungicidal activity was revealed in the vapor contact method.

  6. Comparison of Carrot Broth- and Selective Todd-Hewitt Broth-Enhanced PCR Protocols for Real-Time Detection of Streptococcus agalactiae in Prenatal Vaginal/Anorectal Specimens ▿

    OpenAIRE

    Block, Timothy; Munson, Erik; Culver, Anne; Vaughan, Katharine; Hryciuk, Jeanne E.

    2008-01-01

    The reporting of accurate Streptococcus agalactiae screening results in a short time frame is of tremendous clinical benefit. A total of 203 consecutive primary vaginal/anorectal specimens were cultured in selective Todd-Hewitt broth (LIM broth) and with the StrepB carrot broth kit (carrot broth). One-day broth cultures were subjected to both centrifugation and clarification of a 500-μl aliquot prior to sample lysis (protocol A) and direct lysis of a 50-μl aliquot (protocol B). The lysates we...

  7. Temporal Characterization of Carrot Broth-Enhanced Real-Time PCR as an Alternative Means for Rapid Detection of Streptococcus agalactiae from Prenatal Anorectal and Vaginal Screenings ▿

    OpenAIRE

    Munson, Erik; Napierala, Maureen; Munson, Kimber L.; Culver, Anne; Hryciuk, Jeanne E.

    2010-01-01

    Analysis of overnight carrot broth culture using the BD GeneOhm StrepB assay (carrot broth-enhanced PCR) yields increased sensitivity compared to that of carrot broth culture alone for the detection of Streptococcus agalactiae. We investigated the prospect of reducing the carrot broth incubation time prior to PCR performance. In vitro experimentation demonstrated that carrot broth-enhanced PCR nominally detected 10 CFU S. agalactiae after 4 h of carrot broth incubation with competitive flora....

  8. 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...

  9. 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 ...

  10. Improved detection of methicillin-resistant Staphylococcus aureus using phenyl mannitol broth containing aztreonam and ceftizoxime.

    NARCIS (Netherlands)

    H.F.L. Wertheim (Heiman); H.A. Verbrugh (Henri); C. van Pelt (Cindy); P. de Man (Peter); A.F. van Belkum (Alex); M.C. Vos (Margreet)

    2001-01-01

    textabstractWe tested a phenyl mannitol broth containing ceftizoxime and aztreonam (PHMB(+)) for detection of methicillin-resistant Staphylococcus aureus (MRSA) with reference MRSA strains and, subsequently, with clinical samples (n = 1,098). All reference MRSA strains

  11. Comparative analysis of mixing distribution in aerobic stirred bioreactor for simulated yeasts and fungus broths.

    Science.gov (United States)

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

    2007-01-01

    The study on mixing distribution for an aerobic stirred bioreactor and simulated (solutions of carboxymethylcellulose sodium salt), yeasts (S. cerevisiae) and fungus (P. chrysogenum pellets and free mycelia) broths indicated the significant variation of mixing time on the bioreactor height. The experiments suggested the possibility to reach a uniform mixing in whole bulk of the real broths for a certain value of rotation speed or biomass concentration domain. For S. cerevisiae broths the optimum rotation speed increased to 500 rpm with the biomass accumulation from 40 to 150 g/l d.w. Irrespective of their morphology, for fungus cultures the existence of optimum rotation speed (500 rpm) has been recorded only for biomass concentration below 24 g/l d.w. The influence of aeration rate depends on the apparent viscosity/biomass concentration and on the impellers and sparger positions. By increasing the apparent viscosity for simulated broths, or biomass amount for real broths, the shape of the curves describing the mixing time variation is significantly changed for all the considered positions. The intensification of the aeration induced the increase of mixing time, which reached a maximum value, decreasing then, due to the flooding phenomena. This variation became more pronounced at higher viscosities for simulated broths, at higher yeasts concentration, and at lower pellets or filamentous fungus concentration, respectively. By means of the experimental data and using MATLAB software, some mathematical correlations for mixing time have been proposed for each broth and considered position inside the bioreactor. These equations offer a good agreement with the experiment, the maximum deviation being +/-7.3% for S. cerevisiae broths.

  12. Salting-out Extraction of 2,3-Butanediol from Jerusalem artichoke-based Fermentation Broth

    Institute of Scientific and Technical Information of China (English)

    DAI Jianying; ZHANG Yuanli; XIU Zhilong

    2011-01-01

    The removal of solid impurities and separation of target products from a fermentation broth is becoming more tedious with the utilization of lignocelluloses as source of substrate.2,3-Butanediol,an important chemical used widely is also a main product of sugar-based fermentation carried out by Klebsiella pneumoniae.In this study,we investigated the use of salting-out extraction(SOE) that employed a K2HPO4/ethanol system consisting of 21% ethanol and 17% K2HPO4(mass fraction) to separate 2,3-butanediol from the viscous Jerusalem artichoke-based fermentation broth.After SOE,about 98% of solid matters was removed,and the viscosity decreased from 72.5 mPa s in the original fermentation broth to 4.4 mPa s in the top phase.The partition coefficient and yield of 2,3-butanediol reached 13.4 and 99%,respectively,and 89% of soluble proteins was removed from the broth.The results showed that SOE is an efficient way for isolating 2,3-BD from a highly viscous fermentation broth by removing much of the solid matters within the broth.

  13. Identification of bacteria in blood culture broths using matrix-assisted laser desorption-ionization Sepsityper™ and time of flight mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Jen Kok

    Full Text Available Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS is a novel method for the direct identification of bacteria from blood culture broths. We evaluate for the first time, the performance of the MALDI Sepsityper™ Kit and MS for the identification of bacteria compared to standard phenotypic methods using the manufacturer's specified bacterial identification criteria (spectral scores ≥1.700-1.999 and ≥2.000 indicated identification to genus and species level, respectively. Five hundred and seven positive blood culture broths were prospectively examined, of which 379 (74.8%; 358 monomicrobial, 21 polymicrobial were identified by MALDI-TOF MS; 195 (100% and 132 (67.7% of 195 gram-positive; and 163 (100% and 149 (91.4% of 163 gram-negative organisms from monomicrobial blood cultures were correctly identified to genus and species level, respectively. Spectral scores <1.700 (no identification were obtained in 128/507 (25.2% positive blood culture broths, including 31.6% and 32.3% of gram-positive and polymicrobial blood cultures, respectively. Significantly more gram-negative organisms were identified compared to gram-positive organisms at species level (p<0.0001. Five blood cultures were misidentified, but at species level only; including four monomicrobial blood cultures with Streptococcus oralis/mitis that were misidentified as Streptococcus pneumoniae. Positive predictive values for the direct identification of both gram-positive and gram-negative bacteria from monomicrobial blood culture broths to genus level were 100%. A diagnostic algorithm for positive blood culture broths that incorporates gram staining and MALDI-TOF MS should identify the majority of pathogens, particularly to genus level.

  14. Two new cyclopeptides from the co-culture broth of two marine mangrove fungi and their antifungal activity

    Directory of Open Access Journals (Sweden)

    Song Huang

    2014-01-01

    Full Text Available Background: The strategy that co-cultivation two microorganisms in a single confined environment were recently developed to generate new active natural products. In the study, two new cyclic tetrapeptides, cyclo (D-Pro-L-Tyr-L-Pro-L-Tyr (1 and cyclo (Gly-L-Phe-L-Pro-L-Tyr (2 were isolated from the co-culture broth of two mangrove fungi Phomopsis sp. K38 and Alternaria sp. E33. Their antifungal activity against Candida albicans, Gaeumannomyces graminis, Rhzioctonia cerealis, Helminthosporium sativum and Fusarium graminearum was evaluated. Materials and Methods: Different column chromatographic techniques with different solvent systems were used to separate the constituents of the n-butyl alcohol extract of the culture broth. The structures of compounds 1 and 2 were identified by analysis of spectroscopic data (one-dimensional, two-dimensional - nuclear magnetic resonance, mass spectrometry and Marfey′s analytic method. Dilution method was used for the evaluation of antifungal activity. Results: Compounds 1 and 2 were identified as cyclo (D-Pro-L-Tyr-L-Pro-L-Tyr and cyclo (Gly-L-Phe-L-Pro-L-Tyr, respectively. Compounds 1 and 2 showed moderate to high antifungal activities as compared with the positive control. Conclusions: Compounds 1 and 2 are new cyclopeptides with moderate antifungal activity being worthy of consideration for the development and research of antifungal agents.

  15. Two new cyclopeptides from the co-culture broth of two marine mangrove fungi and their antifungal activity

    Science.gov (United States)

    Huang, Song; Ding, Weijia; Li, Chunyuan; Cox, Daniel G.

    2014-01-01

    Background: The strategy that co-cultivation two microorganisms in a single confined environment were recently developed to generate new active natural products. In the study, two new cyclic tetrapeptides, cyclo (D-Pro-L-Tyr-L-Pro-L-Tyr) (1) and cyclo (Gly-L-Phe-L-Pro-L-Tyr) (2) were isolated from the co-culture broth of two mangrove fungi Phomopsis sp. K38 and Alternaria sp. E33. Their antifungal activity against Candida albicans, Gaeumannomyces graminis, Rhzioctonia cerealis, Helminthosporium sativum and Fusarium graminearum was evaluated. Materials and Methods: Different column chromatographic techniques with different solvent systems were used to separate the constituents of the n-butyl alcohol extract of the culture broth. The structures of compounds 1 and 2 were identified by analysis of spectroscopic data (one-dimensional, two-dimensional - nuclear magnetic resonance, mass spectrometry) and Marfey's analytic method. Dilution method was used for the evaluation of antifungal activity. Results: Compounds 1 and 2 were identified as cyclo (D-Pro-L-Tyr-L-Pro-L-Tyr) and cyclo (Gly-L-Phe-L-Pro-L-Tyr), respectively. Compounds 1 and 2 showed moderate to high antifungal activities as compared with the positive control. Conclusions: Compounds 1 and 2 are new cyclopeptides with moderate antifungal activity being worthy of consideration for the development and research of antifungal agents. PMID:25422539

  16. Ion-exclusion chromatography determination of organic acid in uridine 5'-monophosphate fermentation broth.

    Science.gov (United States)

    Niu, Huanqing; Chen, Yong; Xie, Jingjing; Chen, Xiaochun; Bai, Jianxin; Wu, Jinglan; Liu, Dong; Ying, Hanjie

    2012-09-01

    Simultaneous determination of organic acids using ion-exclusion liquid chromatography and ultraviolet detection is described. The chromatographic conditions are optimized when an Aminex HPX-87H column (300 × 7.8 mm) is employed, with a solution of 3 mmol/L sulfuric acid as eluent, a flow rate of 0.4 mL/min and a column temperature of 60°C. Eight organic acids (including orotic acid, α-ketoglutaric acid, citric acid, pyruvic acid, malic acid, succinic acid, lactic acid and acetic acid) and one nucleotide are successfully quantified. The calibration curves for these analytes are linear, with correlation coefficients exceeding 0.999. The average recovery of organic acids is in the range of 97.6% ∼ 103.1%, and the relative standard deviation is in the range of 0.037% ∼ 0.38%. The method is subsequently applied to obtain organic acid profiles of uridine 5'-monophosphate culture broth fermented from orotic acid by Saccharomyces cerevisiae. These data demonstrate the quantitative accuracy for nucleotide fermentation mixtures, and suggest that the method may also be applicable to other biological samples. PMID:22634191

  17. [Determination of sugars, organic acids and alcohols in microbial consortium fermentation broth from cellulose using high performance liquid chromatography].

    Science.gov (United States)

    Jiang, Yan; Fan, Guifang; Du, Ran; Li, Peipei; Jiang, Li

    2015-08-01

    A high performance liquid chromatographic method was established for the determination of metabolites (sugars, organic acids and alcohols) in microbial consortium fermentation broth from cellulose. Sulfate was first added in the samples to precipitate calcium ions in microbial consortium culture medium and lower the pH of the solution to avoid the dissociation of organic acids, then the filtrates were effectively separated using high performance liquid chromatography. Cellobiose, glucose, ethanol, butanol, glycerol, acetic acid and butyric acid were quantitatively analyzed. The detection limits were in the range of 0.10-2.00 mg/L. The linear correlation coefficients were greater than 0.999 6 in the range of 0.020 to 1.000 g/L. The recoveries were in the range of 85.41%-115.60% with the relative standard deviations of 0.22% -4.62% (n = 6). This method is accurate for the quantitative analysis of the alcohols, organic acids and saccharides in microbial consortium fermentation broth from cellulose.

  18. Invasive mycosis due to species of Blastobotrys in immunocompromised patients with reduced susceptibility to antifungals

    NARCIS (Netherlands)

    Kumar, A.; Babu, R.; Bijulal, S.; Abraham, M.; Sasidharan, P.; Kathuria, S.; Sharma, C.; Meis, J.F.G.M.; Chowdhary, A.

    2014-01-01

    Cases of invasive mycosis due to Blastobotrys serpentis and B. proliferans identified by sequencing in a preterm patient and a rhabdomyosarcoma patient, respectively, are reported. Both species revealed elevated fluconazole and echinocandin MICs by the CLSI broth microdilution method. Additionally,

  19. Detonation nanodiamonds for rapid detection of clinical isolates of Mycobacterium tuberculosis complex in broth culture media.

    Science.gov (United States)

    Soo, Po-Chi; Kung, Ching-Jen; Horng, Yu-Tze; Chang, Kai-Chih; Lee, Jen-Jyh; Peng, Wen-Ping

    2012-09-18

    Routinely used molecular diagnostic methods for mycobacterium identification are expensive and time-consuming. To tackle this problem, we develop a method to streamline identification of Mycobacterium tuberculosis complex (MTBC) in broth culture media by using detonation nanodiamonds (DNDs) as a platform to effectively capture the antigen secreted by MTBC which is cultured in BACTEC MGIT 960, followed by the analysis of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). The 5 nm DNDs can capture the MTBC secretory antigen without albumin interference. With on diamond digestion, we confirm the DND captured antigen is cell filtrate protein 10 (CFP-10) because its Mascot analysis shows a score of 68. The dot blotting method further verifies a positive reaction with anti-CFP-10, indicating that CFP-10 is secreted in the medium of mycobacterium growth indicator tube (MGIT) and captured by DNDs. The minimal CFP-10 protein detection limit was 0.09 μg/mL. Furthermore, our approach can avoid the false-positive identification of MTBC by immunological methods due to cross-reactivity. Five hundred consecutive clinical specimens subjected to routine mycobacteria identification in hospital were used in this study, and the sensitivity of our method is 100% and the specificity is 98%. The analysis of each MTBC sample from culture solution can be finished within 1 h and thus shortens the turnaround time of MTBC identification of gold standard culture methods. In sum, DND MALDI-TOF MS for the detection of MTBC is rapid, specific, safe, reliable, and inexpensive. PMID:22905748

  20. Antimicrobial Activity of a Neem Cake Extract in a Broth Model Meat System

    Directory of Open Access Journals (Sweden)

    Marcello Nicoletti

    2013-08-01

    Full Text Available This work reports on the antimicrobial activity of an ethyl acetate extract of neem (Azadirachta indica cake (NCE against bacteria affecting the quality of retail fresh meat in a broth model meat system. NCE (100 µg was also tested by the agar disc diffusion method. It inhibited the growth of all tested microorganisms. The NCE growth inhibition zone (IZ ranged 11.33–22.67 mm while the ciprofloxacin (10 µg IZ ranged from 23.41–32.67 mm. There was no significant difference (p ≤ 0.05 between the antimicrobial activity of NCE and ciprofloxacin vs. C. jejuni and Leuconostoc spp. The NCE antibacterial activity was moreover determined at lower concentrations (1:10–1:100,000 in micro-assays. The percent growth reduction ranged from 61 ± 2.08–92 ± 3.21. The higher bacterial growth reduction was obtained at 10 µg concentration of NCE. Species-specific PCR and multiplex PCR with the DNA dye propidium monoazide were used to directly detect viable bacterial cells from experimentally contaminated meat samples. The numbers of bacterial cells never significantly (p ≤ 0.05 exceeded the inocula concentration used to experimentally contaminate the NCE treated meat. This report represents a screening methodology to evaluate the antimicrobial capability of a herbal extract to preserve meat.

  1. 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.

  2. Ergosterols from the Culture Broth of Marine Streptomyces anandii H41-59

    Directory of Open Access Journals (Sweden)

    Yang-Mei Zhang

    2016-05-01

    Full Text Available An actinomycete strain, H41-59, isolated from sea sediment in a mangrove district, was identified as Streptomyces anandii on the basis of 16S rDNA gene sequence analysis as well as the investigation of its morphological, physiological and biochemical characteristics. Three new ergosterols, ananstreps A–C (1–3, along with ten known ones (4–13, were isolated from the culture broth of this strain. The gross structures of these new compounds were elucidated on the basis of extensive analysis of spectroscopic data, including HR-ESI-MS, and NMR. The cytotoxicities of these isolates against human breast adenocarcinoma cell line MCF-7, human glioblastoma cell line SF-268, and human lung cancer cell line NCI-H460 and their antibacterial activities in inhibiting the growth of Candida albicans and some other pathogenic microorganisms were tested. Compounds 3–8, 10 and 11 displayed cytotoxicity with IC50 values in a range from 13.0 to 27.8 μg/mL. However, all the tested compounds showed no activity on C. albicans and other bacteria at the test concentration of 1 mg/mL with the paper disc diffusion method.

  3. Biological evaluation of Phellinus linteus-fermented broths as anti-inflammatory agents.

    Science.gov (United States)

    Lin, Chun-Jung; Lien, Hsiu-Man; Chang, Hsiao-Yun; Huang, Chao-Lu; Liu, Jau-Jin; Chang, Yun-Chieh; Chen, Chia-Chang; Lai, Chih-Ho

    2014-07-01

    Phellinus linteus and its constituent hispolon induce potent anti-inflammatory activity in macrophages. Efficient production of the effective constituent and the biological function of P. linteus in the regulation of innate sensing have rarely been investigated. The aim of this study was to efficiently manufacture P. linteus-fermented broth containing the effective constituent, hispolon, and evaluate its immunoregulatory functions in macrophages. Four distinct fermented broths (PL1-4) and the medium dialyzate (MD) were prepared to screen suitable culture conditions for the mycelial growth of P. linteus. The P. linteus-fermented broth exhibited a dose-responsive inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production by murine macrophages. In addition, the P. linteus-fermented broths suppressed macrophage LPS-mediated nuclear factor (NF)-κB activity and tumor necrosis factor (TNF)-α. Among the tested samples from P. linteus, PL4 contained vast amounts of hispolon and showed the greatest anti-inflammatory activity in both the RAW264.7 cells and murine primary peritoneal exudate macrophages (PEMs). This study demonstrates that the purification of the effective constituent from P. linteus-fermented broth may enable the production of a potent therapeutic agent for anti-inflammation in macrophages. PMID:24503424

  4. A new anti-hypoxia functional agent Schizophyllum commune fermented broth and its biochemical mechanisms

    Institute of Scientific and Technical Information of China (English)

    Hao Limin; Lu Jike; Wu Tianyi; Ba Jianming; Guo Changjiang; Qian Ping; Yu Jianyong

    2013-01-01

    In order to overcome hypoxia induced sickness,a stable source of anti-hypoxia functional agents,Schizophyllum commune fermented broth has been developed in this study.Animal experiments were conducted to examine its anti-hypoxia activities and possible mechanisms involved.The acute hypoxic experiment showed that Schizophyllum commune fermented broth could significantly prolong the survival time of mice.The underlying mechanisms were associated with improved energy metabolism based on a study carried out in rats exposed to a low pressure chamber simulating the low pressure environment of 8000 m altitude.It was concluded that the Schizophyllum commune fermented broth was an effective anti-hypoxia functional agent and could be greatly beneficial to those living and working at high altitudes,such as people who reside in the reconstruction regions of Yushu.

  5. Effect of Pretreating the Broth of Hyaluronic Acid by Ultrasonic Wave%超声波对发酵液中提取透明质酸的影响

    Institute of Scientific and Technical Information of China (English)

    吴华昌; 马钦元; 邓静; 石岩昌; 由耀辉

    2009-01-01

    Objective:Taking the improvement of the extraction rate.Method:The effect of purification of Hyaluronic acid from broth by ethanol precipitation method was investigated by pretreating the broth using ultrasonic wave.Result: For the untreated broth,the extraction rate of Hyaluronic acid from the treated broth was improved by 38.6% under the condition of ultrasonic wave frequency 40kHz ,ultrasonic time 10min,temperature 15℃ and ultrasonic power 100W.A conclusion could be got that the extraction rate could be improved from the broth pretreated by ultrasonic wave.%目的:提高发酵液中透明质酸的提取率.方法:应用超声波预处理发酵液的方法对醇沉法提取透明质酸的影响进行研究.结果:在超声波功率100W、处理温度15℃、处理时间10min时,透明质酸提取率相对于未经超声波处理的发酵液提高了38.6%.因此,超声波预处理透明质酸发酵液可以达到提高透明质酸提取率的目的.

  6. Preconcentrating (within the broth) secreted extracellular proteins during a bakers' yeast fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Effler, W.T. Jr.; Pandey, N.K.; Tanner, R.D.; Malaney, G.W.; Scott, C.D. (ed.)

    1986-01-01

    Proteins secreted by yeast during the fermentation process are spacially fractionated (concentrated at a particular vertical position) within the fermentation vessel due to the phenomenon of bubble fractionation, despite moderately vigorous mixing. The degree of fractionation is influenced by the conditions in which the fermentation takes place. The broth pH strongly influences the extent of fractionation of specific proteins. In addition fractionation is enhanced under anaerobic conditions, presumably because there are more CO2 bubbles present for hydrophobic protein adsorption. The addition of moderate levels of salt to the broth reduces the fractionation for most (but not all) of the proteins.

  7. Production of High-Viscosity Whey Broths by a Lactose-Utilizing Xanthomonas campestris Strain

    OpenAIRE

    Schwartz, Robert D.; Bodie, Elizabeth A.

    1985-01-01

    Xanthomonas campestris BB-1L was isolated by enrichment and selection by serial passage in a lactose-minimal medium. When BB-1L was subsequently grown in medium containing only 4% whey and 0.05% yeast extract, the lactose was consumed and broth viscosities greater than 500 cps at a 12 s−1 shear rate were produced. Prolonged maintenance in whey resulted in the loss of the ability of BB-1L to produce viscous broths in whey, indicating a reversion to preferential growth on whey protein, like the...

  8. 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

  9. 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

  10. Studies on Concentration Process of Bacillus thuringiensis Fermentation Broth%苏云金芽孢杆菌发酵液浓缩工艺研究

    Institute of Scientific and Technical Information of China (English)

    周荣华; 崔怡宁; 饶犇; 廖先清; 刘芳; 陈伟

    2015-01-01

    通过对2种不同亚种的苏云金芽孢杆菌(Bacillus thuringiensis)发酵液进行浓缩工艺的研究,探索了不同温度对浓缩液有效成分的影响程度,比较了不同浓缩方式﹑不同干燥方式处理下有效成分的回收率. 结果表明,真空薄膜浓缩工艺的回收率要高于离心浓缩工艺23%~29%.%The concentration processes of two different subspecies of Bacillus thuringiensis fermentation broth were studied.The impact of different concentrate temperatures on the active ingredient of the fermentation broth was explored.The active ingredient recoveries of the fermentation broth deal with different concentration methods and different drying methods were compared.The results showed that the recovery by using vacuum thin film concentration was 23%~29% higher than concen-tration by centrifuging.

  11. Production of cell-free xanthan fermentation broth by cell adsorption on fibers

    Science.gov (United States)

    Yang; Lo; Chattopadhyay

    1998-03-01

    Xanthan gum is a microbial polysaccharide widely used in food and oil-drilling industries. Xanthan gum produced from the current commercial fermentation process usually contains cells and cell debris, which lower the filterability of the xanthan solution and limit its applications. The production of cell-free xanthan gum fermentation broth is thus desirable. The feasibility of removing cells from the xanthan fermentation broth by cell adsorption to various woven fibrous materials was studied. It was found that both cotton and polyester fibers could be used to adsorb Xanthomonas campestris cells present in the fermentation broth either during batch fermentation or after the fermentation. Almost all cells were removed from the fermentation broth by adsorption to fibers. Cotton terry cloth had rough surfaces and was the preferred material for cell adsorption. Cell adsorption to cotton was faster than to polyester fibers. The adsorption kinetics can be modeled by a first-order rate equation. The adsorption rate constants were 30-40% higher for cotton than for polyester. Cell adsorption was not efficient in the absence of xanthan gum, suggesting that the exopolysaccharide, xanthan gum, was important for efficient cell adsorption to fibers. PMID:9548777

  12. 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. PMID:26782652

  13. 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.

  14. Influence of different susceptibility testing methods and media on determination of the relevant fluconazole minimum inhibitory concentrations for heavy trailing Candida isolates with low-high phenotype.

    Science.gov (United States)

    Alp, Sehnaz; Sancak, Banu; Hascelik, Gulsen; Arikan, Sevtap

    2010-11-01

    We investigated the incidence of trailing growth with fluconazole in 101 clinical Candida isolates (49 C. albicans and 52 C. tropicalis) and tried to establish the convenient susceptibility testing method and medium for fluconazole minimum inhibitory concentration (MIC) determination. MICs were determined by CLSI M27-A2 broth microdilution (BMD) and Etest methods on RPMI-1640 agar supplemented with 2% glucose (RPG) and on Mueller-Hinton agar supplemented with 2% glucose and 0.5 μg ml(-1) methylene blue (GMB). BMD and Etest MICs were read at 24 and 48 h, and susceptibility categories were compared. All isolates were determined as susceptible with BMD, Etest-RPG and Etest-GMB at 24 h. While all isolates were interpreted as susceptible at 48 h on Etest-RPG and Etest-GMB, one C. albicans isolate was interpreted as susceptible-dose dependent (S-DD) and two C. tropicalis isolates were interpreted as resistant with BMD. On Etest-RPG, trailing growth caused widespread microcolonies within the inhibition zone and resulted in confusion in MIC determination. On Etest-GMB, because of the nearly absence of microcolonies within the zone of inhibition, MICs were evaluated more easily. We conclude that, for the determination of fluconazole MICs of trailing Candida isolates, the Etest method has an advantage over BMD and can be used along with this reference method. Moreover, GMB appears more beneficial than RPG for the fluconazole Etest. PMID:19563491

  15. Effective control of Listeria monocytogenes by combination of nisin formulated and slowly released into a broth system.

    Science.gov (United States)

    Chi-Zhang, Yundong; Yam, Kit L; Chikindas, Michael L

    2004-01-01

    In order to identify conditions for efficient food preservation by nisin, the sensitivity of Listeria monocytogenes to this preservative was studied under the following three model conditions: (1) the instantaneous addition of nisin into broth medium to simulate the formation of nisin in foods, (2) the slow delivery of nisin solution into broth medium using a pump to simulate the slow release of nisin from packaging materials to foods, (3) a combination of the two delivery methods. Based on the following results, we conclude that the antimicrobial effectiveness of nisin strongly depends on its mode of delivery. The instantaneous and slow methods for adding nisin inhibited L. monocytogenes, but over time of exposure, L. monocytogenes developed tolerance to nisin. Our data indicate that cells treated with instantaneously added nisin developed resistance to higher concentrations of nisin (200 IU/ml), compared to cells treated with slowly added nisin at the same total amount of the antimicrobial. Further studies indicated that nisin-tolerant cells recovered from treatments in which 200 IU/ml nisin was added instantaneously were likely to be mutants, which became resistant to the bacteriocin. In contrast, when 200 IU/ml of the antimicrobial was added slowly to the cells, only a temporary tolerance was developed; these cells became nisin-sensitive after passage through nisin-free medium. Due to the development of nisin-resistant cells, excessive amounts of nisin in the model system did not further inhibit L. monocytogenes. These results signify that excess nisin in foods does not necessarily improve the efficiency of controlling L. monocytogenes. Our data suggest that the combination of packaging material containing nisin used in conjunction with nisin-containing foods will provide the most effective means of preventing L. monocytogenes growth. PMID:14672827

  16. 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.

  17. Pharmacodynamic Interaction of Quercus infectoria Galls Extract in Combination with Vancomycin against MRSA Using Microdilution Checkerboard and Time-Kill Assay.

    Science.gov (United States)

    Basri, Dayang Fredalina; Khairon, Radhiah

    2012-01-01

    The galls of Quercus infectoria Olivier possess astringent properties which helps in the tightening of the vaginal epithelium in the post-natal period. The present study aimed to observe the time-kill kinetics of the acetone and methanol extracts of gall of Q. infectoria in combination with vancomycin against two methicillin-resistant Staphylococcus aureus (MRSA) strains; ATCC 33591 and MU 9495 (laboratory-passaged strain). Minimum inhibitory concentration (MIC) of the extracts were determined using microdilution technique whereas the checkerboard and time-kill kinetics were employed to verify the synergistic effects of treatment with vancomycin. The FIC index value of the combinations against both MRSA strains showed that the interaction was synergistic (FIC index infectoria with vancomycin were synergistic according to FIC index values. The time-kill curves showed that the interaction was additive with a more rapid killing rate but, which did not differ significantly with vancomycin. PMID:22899953

  18. Downstream extraction process development for recovery of organic acids from a fermentation broth.

    Science.gov (United States)

    Bekatorou, Argyro; Dima, Agapi; Tsafrakidou, Panagiotia; Boura, Konstantina; Lappa, Katerina; Kandylis, Panagiotis; Pissaridi, Katerina; Kanellaki, Maria; Koutinas, Athanasios A

    2016-11-01

    The present study focused on organic acids (OAs) recovery from an acidogenic fermentation broth, which is the main problem regarding the use of OAs for production of ester-based new generation biofuels or other applications. Specifically, 10 solvents were evaluated for OAs recovery from aqueous media and fermentation broths. The effects of pH, solvent/OAs solution ratios and application of successive extractions were studied. The 1:1 solvent/OAs ratio showed the best recovery rates in most cases. Butyric and isobutyric acids showed the highest recovery rates (80-90%), while lactic, succinic, and acetic acids were poorly recovered (up to 45%). The OAs recovery was significantly improved by successive 10-min extractions. Alcohols presented the best extraction performance. The process using repeated extractions with 3-methyl-1-butanol led to the highest OAs recovery. However, 1-butanol can be considered as the most cost-effective option taking into account its price and availability. PMID:27560489

  19. Antibacterial activity of 11 essential oils against Bacillus cereus in tyndallized carrot broth.

    Science.gov (United States)

    Valero, M; Salmerón, M C

    2003-08-15

    The antibacterial activity of 11 essential oils from aromatic plants against the strain INRA L2104 of the foodborne pathogen Bacillus cereus grown in carrot broth at 16 degrees C was studied. The quantity needed by the essential oils of nutmeg, mint, clove, oregano, cinnamon, sassafras, sage, thyme or rosemary to produce 14-1110% relative extension of the lag phase was determined. Total growth inhibition of bacterial spores was observed for some of the antimicrobial agents assayed. The addition of 5 microl cinnamon essential oil per 100 ml of broth in combination with refrigeration temperatures of oil. Furthermore, the study of the sensory characteristics of the final product suggests that the use of cinnamon essential oil can be considered as an alternative to "traditional food preservatives". PMID:12810272

  20. Nanofiltration, bipolar electrodialysis and reactive extraction hybrid system for separation of fumaric acid from fermentation broth.

    Science.gov (United States)

    Prochaska, Krystyna; Staszak, Katarzyna; Woźniak-Budych, Marta Joanna; Regel-Rosocka, Magdalena; Adamczak, Michalina; Wiśniewski, Maciej; Staniewski, Jacek

    2014-09-01

    A novel approach based on a hybrid system allowing nanofiltration, bipolar electrodialysis and reactive extraction, was proposed to remove fumaric acid from fermentation broth left after bioconversion of glycerol. The fumaric salts can be concentrated in the nanofiltration process to a high yield (80-95% depending on pressure), fumaric acid can be selectively separated from other fermentation components, as well as sodium fumarate can be conversed into the acid form in bipolar electrodialysis process (stack consists of bipolar and anion-exchange membranes). Reactive extraction with quaternary ammonium chloride (Aliquat 336) or alkylphosphine oxides (Cyanex 923) solutions (yield between 60% and 98%) was applied as the final step for fumaric acid recovery from aqueous streams after the membrane techniques. The hybrid system permitting nanofiltration, bipolar electrodialysis and reactive extraction was found effective for recovery of fumaric acid from the fermentation broth.

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

    OpenAIRE

    Esmeray Küley; Fatih Özogul; Esra Balikçi; Mustafa Durmus; Deniz Ayas

    2013-01-01

    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 obser...

  2. Evaluation of nanofiltration for the purification of an organic acid fermentation broth

    OpenAIRE

    Bouchoux, Antoine; Lutin, F.; Roux-De Balmann, Hélène

    2006-01-01

    This study focuses on a possible elimination of glucose from a sodium lactate fermentation broth by nanofiltration (NF). The results obtained with single-solute solutions indicate that glucose is clearly more retained that sodium lactate. Nevertheless, glucose retention strongly decreases when the two solutes are present in the same solution and the separation becomes unachievable. Such a incidence of a solute on another in NF has rarely been reported before.

  3. 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.

  4. [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

  5. Evaluation of Three Commercial Broth Media for Pigment Detection and Identification of a Group B Streptococcus (Streptococcus agalactiae)▿

    OpenAIRE

    Carvalho, Maria da Glória; Facklam, Richard; Jackson, Delois; Beall, Bernard; McGee, Lesley

    2009-01-01

    Detection of group B Streptococcus (GBS) strains at various bacterial concentrations was evaluated using three pigment-producing broth media. At 103 CFU/ml, StrepB carrot broth (SBCB), Granada instant liquid biphasic (IGLB), and Northeast Laboratory GBS screening medium (NEL-GBS) showed 100% detection, but at the lower bacterial counts, SBCB and IGLB were more sensitive than NEL-GBS after 24 h.

  6. Production of staphylococcal enterotoxins in microbial broth and milk by Staphylococcus aureus strains harboring seh gene.

    Science.gov (United States)

    Schubert, Justyna; Podkowik, Magdalena; Bystroń, Jarosław; Bania, Jacek

    2016-10-17

    Twenty Staphylococcus aureus strains harboring seh gene, including one carrying also sec gene and 11 sea gene, were grown in BHI+YE broth and milk and were tested for SEA, SEC and SEH production. All strains decreased pH of BHI+YE broth at 24h and increased them at 48h. Seventeen S. aureus strains grown in milk changed pH for no >0.3 unit until 48h. Three other S. aureus strains significantly decreased pH during growth in milk. All S. aureus produced SEH in BHI+YE broth in amounts ranging from 95 to 1292ng/ml, and from 170 to 4158ng/ml at 24 and 48h, respectively. SEH production in milk by 17 strains did not exceed 23ng/ml at 24h and 36ng/ml at 48h. Three S. aureus strains able to decrease milk pH produced 107-3029ng/ml and 320-4246ng/ml of SEH in milk at 24 and 48h, respectively. These strains were grown in milk and BHI+YE broth with pH stabilized at values near neutral leading to a significant decrease of SEH production. Representative weak SEH producers were grown in milk at reduced pH resulting in moderate increase in SEH production. SEA was produced in milk by 10S. aureus strains at 24-151ng/ml at 24h, and 31-303ng/ml at 48h. SEA production in milk was higher or comparable as in BHI+YE broth in 3 strains and lower for remaining strains. Production of SEC by sec-positive S. aureus strains was lower in milk than in BHI+YE broth, ranging from 131 to 2319ng/ml at 24 and 48h in milk and 296-30,087ng/ml in BHI+YE at 24 and 48h. Both lacE and lacG transcripts involved in lactose metabolism were significantly up-regulated in milk in strong SEH producers. In these strains hld, rot and sarA transcripts were up-regulated in milk as compared to weak SEH producers. Stabilization of milk pH at a value of raw milk significantly down-regulated hld, rot and sarA RNA in strong SEH producers. Milk was generally found unfavorable for enterotoxin production. However, certain S. aureus strains were not restricted in SEH and SEA expression in milk, unlike SEC which remained down

  7. Green synthesis of palladium nanoparticles using broth of Cinnamomum camphora leaf

    Energy Technology Data Exchange (ETDEWEB)

    Yang Xin; Li Qingbiao, E-mail: kelqb@xmu.edu.cn; Wang Huixuan; Huang Jiale; Lin Liqin; Wang Wenta; Sun Daohua; Su Yuanbo; Opiyo, James Berya; Hong Luwei; Wang Yuanpeng; He Ning; Jia Lishan [College of Chemistry and Chemical Engineering, Xiamen University, Department of Chemical and Biochemical Engineering (China)

    2010-06-15

    The development of dependable, environmentally benign processes for the synthesis of nanoscale materials is an important aspect of nanotechnology. In the present study, we report one-pot biogenic fabrication of palladium nanoparticles by a simple procedure using broth of Cinnamomum camphora leaf without extra surfactant, capping agent, and/or template. The mean size of palladium nanoparticles, ranging from 3.2 to 6.0 nm, could be facilely controlled by merely varying the initial concentration of the palladium ions. The polyols components and the heterocyclic components were believed to be responsible for the reduction of palladium ions and the stabilization of palladium nanoparticles, respectively.

  8. Pharmacodynamic Interaction of Quercus infectoria Galls Extract in Combination with Vancomycin against MRSA Using Microdilution Checkerboard and Time-Kill Assay

    Directory of Open Access Journals (Sweden)

    Dayang Fredalina Basri

    2012-01-01

    Full Text Available The galls of Quercus infectoria Olivier possess astringent properties which helps in the tightening of the vaginal epithelium in the post-natal period. The present study aimed to observe the time-kill kinetics of the acetone and methanol extracts of gall of Q. infectoria in combination with vancomycin against two methicillin-resistant Staphylococcus aureus (MRSA strains; ATCC 33591 and MU 9495 (laboratory-passaged strain. Minimum inhibitory concentration (MIC of the extracts were determined using microdilution technique whereas the checkerboard and time-kill kinetics were employed to verify the synergistic effects of treatment with vancomycin. The FIC index value of the combinations against both MRSA strains showed that the interaction was synergistic (FIC index <0.5. Time-kill assays showed the bactericidal effect of the combination treatment at 1/8XMIC of the extract and 1/8XMIC of vancomycin, were respectively at 7.2±0.28 hr against ATCC 33591 compared to complete attenuation of the growth of the same strain after 8 hr of treatment with vancomycin alone. In conclusion, the combination extracts of Q. infectoria with vancomycin were synergistic according to FIC index values. The time-kill curves showed that the interaction was additive with a more rapid killing rate but, which did not differ significantly with vancomycin.

  9. Optimization of DsbA Purification from Recombinant Escherichia coil Broth Using Box-Behnken Design Methodology

    Institute of Scientific and Technical Information of China (English)

    LUO Man; GUAN Yixin; YAO Shanjing

    2013-01-01

    Disulfide bond formation protein A(DsbA)is one of the important helper proteins for folding in protein synthesis in vivo.In this study,purification of recombinant DsbA was investigated by examining four important factors with Box-Behnken design method,a statistic-based design of experiments.The optimal operation conditions were obtained by adopting the effectiveness coefficient method on the multi-objective problem,which takes the protein recovery,purification efficiency and throughput of ion-exchange chromatography into account.After the optimization,protein recovery of 96.8% and purity higher than 95% DsbA was achieved,and the productivity was (377.9±1.7)mg soluble DsbA per liter broth.The purified protein was identified by peptide mass fingerprinting matching the record of gil2624856,a mutant of DsbA.The DsbA was preliminarily applied to the refolding of denatured lysozyme m vitro.

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

    Directory of Open Access Journals (Sweden)

    Luciano Mengatto

    2006-08-01

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

  11. 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.

  12. 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.

  13. Comparison of Enrichment Broths for Supporting Growth of Shiga Toxin-Producing Escherichia coli.

    Science.gov (United States)

    Stromberg, Zachary R; Lewis, Gentry L; Marx, David B; Moxley, Rodney A

    2015-08-01

    Detection of Shiga toxin-producing Escherichia coli (STEC) in complex sample matrices remains challenging. In an attempt to improve detection, nonselective and selective enrichment broths were compared as follows: (1) trypticase soy broth (TSB) was compared with TSB plus novobiocin, vancomycin, rifampicin, bile salts, and potassium tellurite (TSB-NVRBT) for supporting growth of STEC in pure culture; (2) E. coli broth (EC), TSB, and TSB plus bile salts (mTSB) were compared for enrichment of STEC O26, O45, O103, O104, O111, O121, O145, and O157 (STEC-8) in inoculated cattle fecal samples; (3) EC, TSB, and mTSB were compared for the detection of STEC-8 in inoculated cattle fecal samples. Fecal samples were inoculated with wild-type STEC-8 or nalidixic acid- or rifampicin-resistant derivatives of the same strains at 100, 1000, or 10,000 colony-forming units per gram (CFU/g) of feces. In pure culture, the mean STEC CFU/mL following enrichment in TSB was 1.17 log10 greater than that in TSB-NVRBT (P < 0.05). In inoculated fecal samples, EC enrichment yielded growth of STEC-8 (6.42 log10 CFU/g) that was significantly greater than in TSB (6.23 log10 CFU/g; P < 0.05), and numerically but not significantly greater than in mTSB (6.37 log10 CFU/g; P = 0.60). Wild-type STEC strains were detected in 43.8 % (21/48) of the samples enriched in EC and mTSB compared to 27.1 % (13/48) of the samples enriched in TSB (P = 0.15). Overall, STEC grew significantly better when enriched in EC compared to TSB. Modification of TSB by the addition of bile salts improved the growth and detection of STEC compared to TSB alone. PMID:25917502

  14. Lytic enzyme production optimization using low-cost substrates and its application in the clarification of xanthan gum culture broth

    Science.gov (United States)

    da Silva, Cíntia Reis; Silva, Marilia Lordelo Cardoso; Kamida, Helio Mitoshi; Goes-Neto, Aristoteles; Koblitz, Maria Gabriela Bello

    2014-01-01

    Lytic enzymes are widely used in industrial biotechnology as they are able to hydrolyze the bacterial cell wall. One application of these enzymes is the clarification of the culture broth for the production of xanthan gum, because of its viability in viscous media and high specificity. The screening process for filamentous fungi producing lytic enzymes, the optimization of production of these enzymes by the selected microorganism, and the optimization of the application of the enzymes produced in the clarification of culture broth are presented in this article. Eleven fungal isolates were tested for their ability to produce enzymes able to increase the transmittance of the culture broth containing cells of Xanthomonas campestris. To optimize the secretion of lytic enzymes by the selected microorganism the following variables were tested: solid substrate, initial pH, incubation temperature, and addition of inducer (gelatin). Thereafter, secretion of the enzymes over time of incubation was assessed. To optimize the clarification process a central composite rotational design was applied in which the pH of the reaction medium, the dilution of the broth, and the reaction temperature were evaluated. The isolate identified as Aspergillus tamarii was selected for increasing the transmittance of the broth from 2.1% to 54.8%. The best conditions for cultivation of this microorganism were: use of coconut husk as solid substrate, with 90% moisture, at 30°C for 20 days. The lytic enzymes produced thereby were able to increase the transmittance of the culture broth from 2.1% to 70.6% at 65°C, without dilution and without pH adjustment. PMID:25473487

  15. Ultrafiltración de Caldos de Fermentación Ultrafiltration in Fermentation Broths

    Directory of Open Access Journals (Sweden)

    Carlos Orozco

    2008-01-01

    Full Text Available Se estudió la microfiltración tangencial y ultrafiltración para concentrar caldos de levadura de Phaffia rhodozyma, la que es empleada para la producción del colorante astaxantina. Se emplearon cartuchos de microfiltración y ultrafiltración para evaluar el efecto de las variables de operación sobre el flujo de permeado. Se trabajó con presiones transmembrana de 35 a 210 kPa, flujos de alimentación de 7 a 30 x10-6 m³/s, pH de 4 a 8, y temperatura de 303 a 323 K. El flujo más alto alcanzado en la microfiltración fue de 13 x10-6 m/s, observándose la disminución de éste si el pH aumenta; mientras que para la ultrafiltración el flujo más alto fue de 17 x10-6 m/s. En ambos casos la concentración de levadura máxima alcanzada fue de 250 kg/m³. Los resultados obtenidos muestran que la concentración de caldos de fermentación de Phaffia rhodozyma puede llevarse a cabo tanto por microfiltración tangencial como por ultrafiltración.Tangential microfiltration and ultrafiltration were studied to concentrate Phaffia rhodozym yeast broths, yeast that is used in production of astaxantine colorant. Microfiltration and ultrafiltration cartridges were used to study the effect of the operating variables on the permeated flux. The values used were: transmembranal pressures from 35 to 210 kPa, feeding flows from 7 a 30 x10-6 m³/s, pH from 4 to 8; and temperature from 303 to 323 K. The highest flux for microfiltration was 13 x 10-6 m/s, observing that concentration decreases when the pH increases. For ultrafiltration the maximum flux was 17 x 10-6 m/s. In both cases the maximum yeast concentration was 250 kg/m³. The results show that concentration of Phaffia rhodozym yeast broths can be done using tangential microfiltration or ultrafiltration.

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

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

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

  17. Effect of Modified Tryptone Soy Broth Medium%改良胰蛋白胨大豆肉汤培养基的应用效果

    Institute of Scientific and Technical Information of China (English)

    王洪亮; 程艳宇; 王梦晓

    2016-01-01

    评估GB 4789.11-2014《食品安全国家标准食品微生物检验β型溶血性链球菌检验》中改良胰蛋白胨大豆肉汤培养基的质量。选取国内三家(标记为A、B、C)和国外一家(标记为D)培养基生产商的胰蛋白胨大豆肉汤培养基(商品化脱水合成培养基)和相应添加剂,使用目标菌(乙型溶血性链球菌FSCC225016)和非目标菌(大肠埃希氏菌ATCC25922),依据GB4789.28-2013《食品安全国家标准食品微生物检验培养基和试剂的质量要求》中选择性增菌培养基的定性测试方法进行质量评估。同时不加添加剂进行试验。国内A、B和C三家改良胰蛋白胨大豆肉汤培养基中目标菌浊度值均为0,非目标菌浊度值为0;未加试剂的培养基目标菌浊度值均为0,非目标菌浊度值为0。国外D改良胰蛋白胨大豆肉汤培养基中目标菌浊度值为2,非目标菌浊度值为0;未加试剂的培养基目标菌浊度值为2,非目标菌浊度值为1。国内A、B、C三家的改良胰蛋白胨大豆肉汤培养基质量评估证明是胰蛋白胨大豆肉汤培养基(不加添加剂)基础成分的问题;国产胰蛋白胨大豆肉汤培养基质量有待提高。%Evaluation of GB 4789.11-2014in modified tryptone soy broth medium quality. a total of three domestic(la-beled A, B, C) and foreign(labeled D) a culture based manufacturer of tryptone soya broth culture base(com-mercial dehydration synthetic culture medium) and the corresponding additives, use target bacteria (β-hemolytic streptococcus ATCC21059) and non target bacteria (Escherichia coli ATCC25922,Staphylococcus aureus ATCC25923), according to the GB4789.28-2013in selective enrichment culture based qualitative test method for quality evaluation. At the same time without additives test. The A, B and C three modified tryptone soy broth culture medium target bacteria turbidity values are 0 and non target bacteria turbidity value of 0

  18. Dried bonito broth improves cognitive function via the histaminergic system in mice.

    Science.gov (United States)

    Nozawa, Yoshizu; Mimura, Masako; Yamada, Keiko; Sugita, Mayu; Shibakusa, Tetsuro; Koyama, Naoto

    2014-01-01

    Bonito extract, i.e., dried bonito broth (DBB), has been reported to counteract mental fatigue and to increase performance in a simple calculation task, but the mechanism by which DBB increases task performance is not known. The brain neurotransmitter histamine is biosynthesized only from histidine in the tuberomammillary nucleus. Histamine neurons are projected to almost all areas of the cerebral cortex, and histamine has various behavioral and neurobiological functions, particularly in recognition memory. Here we used a mouse model to investigate the effects of the oral ingestion of DBB, which contains abundant histidine, as well as the ingestion of histidine on cognitive function. In a retention trial of novel object recognition test, the administration of 1.6 g/kg of DBB and 500 mg/kg of histidine significantly increased the animals' exploratory behavior toward a novel object, and that these agents significantly increased the spontaneous alternation behavior ratio in a Y-maze under conditions of scopolamine-induced amnesia, which induced learning and memory impairment. These results suggested the improvement of spatial short-term working memory in a scopolamine amnesia model, as well as the strengthening of visual cognitive function by a single ingestion of DBB and histidine. Interestingly, the administration of αFMH, which is an inhibitor of histamine biosynthesis, eliminated the increase in the spontaneous alternation behavior ratio by DBB ingestion in the scopolamine-induced amnesia model, suggesting that DBB may improve working memory impairment via activation of the histaminergic neuron system. PMID:25355438

  19. Dried bonito broth improves cognitive function via the histaminergic system in mice.

    Science.gov (United States)

    Nozawa, Yoshizu; Mimura, Masako; Yamada, Keiko; Sugita, Mayu; Shibakusa, Tetsuro; Koyama, Naoto

    2014-01-01

    Bonito extract, i.e., dried bonito broth (DBB), has been reported to counteract mental fatigue and to increase performance in a simple calculation task, but the mechanism by which DBB increases task performance is not known. The brain neurotransmitter histamine is biosynthesized only from histidine in the tuberomammillary nucleus. Histamine neurons are projected to almost all areas of the cerebral cortex, and histamine has various behavioral and neurobiological functions, particularly in recognition memory. Here we used a mouse model to investigate the effects of the oral ingestion of DBB, which contains abundant histidine, as well as the ingestion of histidine on cognitive function. In a retention trial of novel object recognition test, the administration of 1.6 g/kg of DBB and 500 mg/kg of histidine significantly increased the animals' exploratory behavior toward a novel object, and that these agents significantly increased the spontaneous alternation behavior ratio in a Y-maze under conditions of scopolamine-induced amnesia, which induced learning and memory impairment. These results suggested the improvement of spatial short-term working memory in a scopolamine amnesia model, as well as the strengthening of visual cognitive function by a single ingestion of DBB and histidine. Interestingly, the administration of αFMH, which is an inhibitor of histamine biosynthesis, eliminated the increase in the spontaneous alternation behavior ratio by DBB ingestion in the scopolamine-induced amnesia model, suggesting that DBB may improve working memory impairment via activation of the histaminergic neuron system.

  20. 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.

  1. Purification of monoclonal antibodies from whole hybridoma fermentation broth by fluidized bed adsorption.

    Science.gov (United States)

    Thömmes, J; Halfar, M; Lenz, S; Kula, M R

    1995-02-01

    To achive the coarse purification of a monoclonal antibody from whole hybridoma fermentation broth a fluidized bed cation exchange process was used. The procedure consisted of application of the crude sample and washing of the bed in a fluidized mode and elution in a fixed bed mode. A completely clarified eluate was obtained with purification factors between 4 and 8 and a concentration of the desired product (monoclonal antibody) by a factor of more than 3 was achived. Thus, a combination of the three early steps of the downstream process clarification, concentration and coarse purification was possible. Two different materials were tested: a commercially available agarose-based matrix (Stream-line-SP), and a self-derivatized material based on controlled-pore glass (Bioran). Initial experiments were performed to describe the fluidization of the glass material. Comparison with the agarose material showed several differences, the agarose matrix allowing liquid flow closer to plug flow than the glass material. Increased backmixing in the liquid phase was detected when fluidizing the glass adsorbent compared with the agarose-based matrix. Despite this fact, comparison of the two materials with respect to antibody binding and elution demonstrated a similar performance. (c) 1995 John Wiley & Sons, Inc.

  2. 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.

  3. Review on Health Functions of Chicken Broths%鸡汤健康功能的研究现状

    Institute of Scientific and Technical Information of China (English)

    何蓉蓉; 李怡芳; 李维熙; 栗原博

    2012-01-01

    There had been a long history of using chicken broths to improve and treat diseases. In traditional medicine, chicken broths had the effects of warming up the body, elevating energy and vitality, strengthening organs and bones, etc. Recent researches proved that consuming chicken broths can relieve cold symptoms, tiredness, promoting metabolism and increasing immune functions. People found that chicken broths are rich in nutrients like proteins, various a-mino acids, minerals and trace elements, etc. Carnosine and anserine which are important nutrients in chicken broth, are histamine dipeptide compounds and antioxidative substances with multiple bioactivities. They act as precursors of central nervous histaminergic transmitters, which can regulate central nervous histamine level and activity of serotonin, and hence activate serotonin-related physiological activities. Results showed that chicken broth can improve sleeping qualities, lighten up mood and regulate rhythm of life. With the industrialization of chicken broth production, people are paying much more attention to functional foods like chicken essences. This article summarizes the researches on active components and physiological effects of chicken broths and elucidates the related mechanisms, which can provide consumers with more beneficial information, on the research and development of chicken broths.%传统医学认为,鸡汤具有温中益气、补虚填精、益五脏健脾胃及强筋骨等效果.近年来的研究证明鸡汤具有缓解感冒症状、消除疲劳、促进机体新陈代谢及增强免疫功能等作用.鸡汤中富合蛋白质、多种氨基酸、多种矿物质及微量元素等营养成分,其中肌肽和鹅肌肽是组胺酰二肽类化合物,不仅是鸡汤中的营养成分,同时也是具有多种生理活性的抗氧化物质.此外,肌肽等小分子化合物又作为中枢组织胺神经递质的前驱活性物质,可以通过组氨酸等代谢途径有效调节

  4. Efficacy of Plectranthus amboinicus (Lour.) Spreng in a Murine Model of Methicillin-Resistant Staphylococcus aureus Skin Abscesses

    OpenAIRE

    Francisco Fábio Martins de Oliveira; Alba Fabiola Torres; Thially Braga Gonçalves; Gilvandete Maria Pinheiro Santiago; Cibele Barreto Mano de Carvalho; Milena Braga Aguiar; Lilia Maria Carneiro Camara; Silvia Helena Rabenhorst; Alice Maria Costa Martins; José Telmo Valença Junior; Aparecida Tiemi Nagao-Dias

    2013-01-01

    The present work aimed to evaluate the effectiveness of Plectranthus amboinicus (Lour.) Spreng against MRSA clinical isolates. The in vitro antimicrobial activity of the hydroalcoholic extract (HE), the ethyl acetate (EA) fraction and its subfractions were determined by broth microdilution and bioautography against MRSA clinical isolates. The microdilution checkerboard method was used to assess in vitro drug combination studies. To induce abscess formation, bacterial suspensions were added to...

  5. 毛锦藓科中国新记录种——卷边麻锦藓%Taxithelium kerianum (Broth.) Broth.(Pylaisiadelphaceae, Bryophyta)Reported New to China

    Institute of Scientific and Technical Information of China (English)

    章博远; 魏倩倩; 韦玉梅; 贾渝; 朱瑞良; 王幼芳

    2015-01-01

    报道了产自广西的毛锦藓科1中国新记录种——卷边麻锦藓[Taxithelium kerianum (Broth.)Broth.],提供了该种详细的形态描述和图版,并编制了麻锦藓属的分种检索表,明确了卷边麻锦藓与中国分布的麻锦藓属其它种类之间的形态差别.该种主要分布在南亚及其附近地区,为典型的热带藓类.

  6. Pharmacia and biological functionalities of nutrient broth dispersed multi-walled carbon nanotubes:A novel drug delivery system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new drug delivery system was developed using the interaction of nutrient broth treated multi-walled carbon nanotubes(NBT-MWCNTs) and cefotaxime sodium(CTX) as a model.Investigated factors of the drug delivery system include dispersion effect,biocompatibility of NBT-MWCNTs,pharmacodynamic effect and delivery efficiency in vitro.It was found that MWCNTs can be well dispersed in the nutrient broth and stable at least for one week at 4 °C.The formed NBT-MWCNTs suspension scarcely exhibits toxicity to E.coli at concentrations lower than 10.24 μg/mL,but displays enhanced pharmacodynamic effect of CTX via its bridge effect and targeted transport.Compared with general acid treated MWCNTs(AT-MWCNTs),our present NBT-MWCNTs show good biocompatibility,enhanced pharmacodynamic effect,and high delivery efficiency.

  7. 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

    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......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...

  8. Effect of cycle time on fungal morphology, broth rheology, and recombinant enzyme productivity during pulsed addition of limiting carbon source.

    Science.gov (United States)

    Bhargava, Swapnil; Wenger, Kevin S; Rane, Kishore; Rising, Vanessa; Marten, Mark R

    2005-03-01

    For many years, high broth viscosity has remained a key challenge in large-scale filamentous fungal fermentations. In previous studies, we showed that broth viscosity could be reduced by pulsed addition of limiting carbon during fed-batch fermentation. The objective in this study was to determine how changing the frequency of pulsed substrate addition affects fungal morphology, broth rheology, and recombinant enzyme productivity. To accomplish this, a series of duplicate fed-batch fermentations were performed in 20-L fermentors with a recombinant glucoamylase producing strain of Aspergillus oryzae. The total cycle time for substrate pulsing was varied over a wide range (30-2,700 s), with substrate added only during the first 30% of each cycle. As a control, a fermentation was conducted with continuous substrate feeding, and in all fermentations the same total amount of substrate was added. Results show that the total biomass concentration remained relatively unaltered, while a substantial decrease in the mean projected area of fungal elements (i.e., average size) was observed with increasing cycle time. This led to reduced broth viscosity and increased oxygen uptake rate. However, high values of cycle time (i.e., 900-2,700 s) showed a significant increase in fungal conidia formation and significantly reduced recombinant enzyme productivity, suggesting that the fungi channeled substrate to storage compounds rather than to recombinant protein. In addition to explaining the effect of cycle time on fermentation performance, these results may aid in explaining the discrepancies observed on scale-up to larger fermentors. PMID:15643626

  9. 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. PMID:26097197

  10. The effects of fermentation and adsorption using lactic acid bacteria culture broth on the feed quality of rice straw

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-jing; LIU Xiao-ping; REN Ji-wei; ZHAO Hong-yan; YUAN Xu-feng; WANG Xiao-fen; Abdelfattah Z M Salem; CUI Zong-jun

    2015-01-01

    To improve the nutritional value and the palatability of air-dried rice straw, culture broth of the lactic acid bacteria community SFC-2 was used to examine the effects of two different treatments, fermentation and adsorption. Air-dried and chopped rice straw was treated with either fermentation for 30 d after adding 1.5 L nutrient solution (50 mL inocula L–1, 1.2×1012 CFU mL–1 inocula) kg–1 straw dry matter, or spraying a large amount of culture broth (1.5 L kg–1 straw dry matter, 1.5×1011 CFU mL–1 culture broth) on the straw and al owing it to adsorb for 30 min. The feed quality and aerobic stability of the resulting forage were examined. Both treatments improved the feed quality of rice straw, and adsorption was better than fermen-tation for preserving nutrients and improving digestibility, as evidenced by higher dry matter (DM) and crude protein (CP) concentrations, lower neutral detergent ifber (NDF), acid detergent ifber (ADF) and NH3-N concentrations, as wel as higher lactic acid production and in vitro digestibility of DM (IVDMD). The aerobic stability of the adsorbed straw and the fermented straw was 392 and 480 h, respectively. After being exposed to air, chemical components and microbial community of the fermented straw were more stable than the adsorbed straw.

  11. Post-irradiation modification of radiation-induced heteroallelic reversion in diploid yeast: effect of nutrient broth

    International Nuclear Information System (INIS)

    The effect of post-irradiation growth in complete rich medium on the expression of the reversion to arginine-independence induced by gamma and alpha radiation in a heteroallelic diploid yeast strain (Saccharomyces cerevisiae BZ34) has been studied. During the post-irradiation treatment the reversion frequency increased, reached a peak at about 90 minutes and decreased thereafter reaching a constant value for treatment periods exceeding 6h. As determined by the increase in number of budding cells, extensive DNA synthesis took place in cells incubated only in the nutrient medium and not in the omission medium. Hence the observed increase in the reversion frequency is explained on the basis that post-irradiation DNA synthesis is necessary for the expression of gene conversion. The decrease in the reversion frequency for continued treatment with yeast extract, peptone, dextrose (YEPD) is related to the fact that only one daughter of the post-irradiation first cell division is a revertant. The broth effect was not lost when the irradiated cells were first incubated for 90 min in arginine-less medium and then transferred to the broth. Similarly, the broth effect even persisted at doses high enough to induce considerable division delay. These results suggest that the radiation-induced pre-conversional lesions are not susceptible to repair by alternative pathways

  12. 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.

  13. 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.

  14. 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. PMID:27554154

  15. Recovery of Acetic Acid from An Ethanol Fermentation Broth by Liquid-Liquid Extraction (LLE) Using Various Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Thi Thu Huong; Kim, Tae Hyun [Kongju National University, Cheonan (Korea, Republic of); Um, Byung Hwan [Hankyong National University, Anseong (Korea, Republic of)

    2015-12-15

    Liquid-liquid extraction (LLE) using various solvents was studied for recovery of acetic acid from a synthetic ethanol fermentation broth. The microbial fermentation of sugars presented in hydrolyzate gives rise to acetic acid as a byproduct. In order to obtain pure ethanol for use as a biofuel, fermentation broth should be subjected to acetic acid removal step and the recovered acetic acid can be put to industrial use. Herein, batch LLE experiments were carried out at 25°C using a synthetic fermentation broth comprising 20.0 g l{sup -1} acetic acid and 5.0 g l{sup -1} ethanol. Ethyl acetate (EtOAc), tri-n-octylphosphine oxide (TOPO), tri-n-octylamine (TOA), and tri-n-alkylphosphine oxide (TAPO) were utilized as solvents, and the extraction potential of each solvent was evaluated by varying the organic phase-to-aqueous phase ratios as 0.2, 0.5, 1.0, 2.0, and 4.0. The highest acetic acid extraction yield was achieved with TAPO; however, the lowest ethanol-to-acetic acid extraction ratio was obtained using TOPO. In a single-stage batch extraction, 97.0 % and 92.4 % of acetic acid could be extracted using TAPO and TOPO when the ratio of organic-to-aqueous phases is 4:1 respectively. A higher solvent-to-feed ratio resulted in an increase in the ethanol-to-acetic acid ratio, which decreased both acetic acid purity and acetic acid extraction yield.

  16. Expression of 87 kD protein in the broth culture filtrate of Helicobacter pylori and its association with the vacuolating effect

    Institute of Scientific and Technical Information of China (English)

    SHI Li; YIE Gui-an; NAN Qing-zhen; SUN Yong; ZHANG Ya-li; ZHANG Zhen-shu; ZHOU Dian-yuan

    2001-01-01

    To study the vacuolating effect of Helicobacter pylori(H.pylori). Method: The vacuolating effect and its relationship with vacuolating cytotoxin antigen (an 87 kD protein) were investigated by the method of cytotoxic test, SDS-PAGE and scanning. Result: Of the 62 clinical isolates, 43 strains were H.pylori (Toxin+) with vacuolating effect, while the others were H.pylori (Toxin-) without vacuolating effect. Altogether 78.26%(36/46) patients with peptic ulcer were infected with H.pylori (Toxin+) strains, and only 42.86%(6/14) who had gastritis were infected with H.pylori (Toxin+) strains, with significant difference between them(χ2=4.83,P<0.05). A protein with relativemolecular mass of 87 kD was identified in the broth culture filter(BCF) of 30.23% H. Pylori (Toxin+) strains (13/43) but in none of that of H.pylori (Toxin-) strains, and the difference was statistically significant(P<0.05). There was a significant and concordant relationship between the OD value of the protein band and the titer of vacuolating activity of H.pylori (Toxin+) (r=0.67 and P<0.05 by linear regression analysis). Conclusion: H.pylori (Toxin+) were more often associated with peptic ulcerous diseases than with gastritis diseases. The vacuolating effect of H.pylori (Toxin+) may be caused by the 87 kD protein.

  17. Inactivation of Escherichia coli in broth and sausage by combined high pressure and Lactobacillus casei cell extract.

    Science.gov (United States)

    Chung, Hyun-Jung; Yousef, Ahmed E

    2010-10-01

    The purpose of this study was to investigate the effect of combined high pressure and Lactobacillus casei cell extract (CE) on Escherichia coli O157 strains with variation in pressure resistance in broth and sausage. Pressure-resistant (O157:H7 and O157:H12) and -sensitive (O157-M1 and O157-M2) E. coli strains were used. Pressure treatment at 350 MPa for 20 min in broth caused 1.1-1.2 logs reduction in O157:H12 and O157:H7 and 4.1-5.5 logs reduction in the O157-M1 and O157-M2. When high pressure was treated in the presence of CE (32 CEAU/mL), the combination treatment caused a significant inactivation in the pressure-resistant O157:H7 strains resulting in the viability loss of 4.3-4.6 logs and the synergistic effect increased with increase in treatment time (p high pressure treatment. The synergy between high pressure processing and Lb. casei OSY-LB6A CE against pressure-resistant E. coli O157 strains suggests the feasibility of using this combination to minimize the risk of transmission of E. coli O157 by food.

  18. The influence of cholesterol and biomass concentration on the uptake of cholesterol by Lactobacillus from MRS broth

    Directory of Open Access Journals (Sweden)

    Małgorzata Ziarno

    2007-06-01

    Full Text Available The aim of this study was the determination of some factors influence (i.e. the vitality of bacteria cells and the cholesterol concentration on the ability of selected Lactobacillus sp. to cholesterol uptake during culture in MRS broth. Three Lactobacillus strains (Lb. delbrueckii subsp. bulgaricus, Lb. acidophilus, Lb. casei isolated from commercial single species lyophilized dairy starter cultures and three Lactobacillus strains (Lb. plantarum, Lb. delbrueckii subsp. bulgaricus, Lb. acidophilus originated from commercial pharmaceuticals were used in this study. The uptake of cholesterol from MRS broth during the growth of Lactobacillus sp., expressed as the difference between the final and the initial concentrations of cholesterol, ranged from 0.053 to 0.153 g/dm³, apart from the initial cholesterol content and the origin of Lactobacillus sp. The results confirmed that biomass concentration have a statistically significant effect on uptake of cholesterol. The ten-fold increase of the amount of intact cells biomass caused about 1.5-2-fold increase of the amount of cholesterol removed. The influence of the concentration of biomass of alive cells on the removal of cholesterol was bigger than in case of the heat-sterilized cells.

  19. PDMS复合膜从发酵液中渗透汽化回收乙醇%Ethanol Recovery from Fermentation Broth by Pervaporation Using a Composite polydimethylsiloxane Membrane

    Institute of Scientific and Technical Information of China (English)

    伍勇; 黄卫星; 肖泽仪; 钟月华

    2004-01-01

    The pervaporation behavior of fermentation broth was investigated experimentally and compared with those started with ethanol mixtures. Ethanol was produced by Saccharomyces cerevisiae utilizing technical grade glucose and recovered by pervaporation using a composite polydimethylsiloxane (PDMS) membrane prepared in our laboratory. Ethanol concentration in fermentation broth decreased to a relatively low level when pervaporation was coupled with fermentation. The more active cells appeared in the fermentation broth, the better the membrane performance was.

  20. Survival and recovery of Salmonella enterica serovar Typhimurium DT104 at low temperature and water activity in a broth system.

    Science.gov (United States)

    Kinsella, Kathleen J; Rowe, Tara A; Blair, Ian S; McDowell, David A; Sheridan, James J

    2006-01-01

    This study investigated the survival of Salmonella enterica serovar Typhimurium DT104 in a broth system under conditions of low temperature (4 degrees C) and low water activity (aw, 0.92 to 0.96). Incubation under these conditions resulted in significant reductions in the viability of stationary phase cells, determined by direct plating on selective XLD medium. Reductions in viable numbers were related to injury associated with initial osmotic shock (hyperosmosis) and further injury associated with longer-term storage under the above conditions. Such injured cells were, however, capable of recovering on a nonselective medium (TSA) and contributing to overall viable cell numbers in nonselective post-storage conditions. Storage at more extreme conditions, at lower aw values, led to cell death at rates influenced by storage temperature. Finally, the data obtained are considered in relation to pathogen survival on the surfaces of beef carcasses during chilling. PMID:17199519

  1. Determination of succinic acid in fermentation broth using thin layer scanning technique%薄层扫描快速检测发酵液中琥珀酸

    Institute of Scientific and Technical Information of China (English)

    林日辉; 余运玲; 黄文勤; 门媛嫒

    2012-01-01

    Based on color reaction between copper sulfate and succinic acid in fermentation broth, succinic acid concentration was determined directly by using thin layer scanning without chromatography. Linear relationship between the value of absorbance and the succinic acid concentration was obtained in the range of 0 - 12 g/L, using 680 nm as measurement wavelength and 500 nm as reference wavelength for scanning. The method detection limit (3 S/k) was 0.028 mg/L with the recoveries of 94. 8% -96. 1% , and the RSD (n =5) was lower than 3. 5%. The interference rate of byproducts was lower than 5. 60% . The paper provided an easy but efficient method for the determination of succinic acid in lab study or industry production.%基于CuSO4与发酵液中琥珀酸的显色反应,在硅胶板上不经层析展开使用薄层扫描定量分析琥珀酸含量.在0~12 g/L范围内,测定波长680 nm,参比波长500 nm条件下,琥珀酸浓度与显色斑吸光度呈良好线性关系.方法检出限(3 S/k)为0.028 mg/L,回收率94.80%~96.12%,相对标准偏差≤3.5%(n=5).发酵液中副产物的干扰率≤5.60%.本研究可为实验室研究或工业生产提供一种简便高效的琥珀酸定量检测方法.

  2. 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.

  3. Simultaneous determination of colistin and levofloxacin in broth by LC-MS/MS%LC-MS/MS法同时测定多粘菌素E和左氧氟沙星的浓度

    Institute of Scientific and Technical Information of China (English)

    梅和坤; 王睿; 白楠; 梁蓓蓓; 曹江; 汶柯; 唐铭婧; 刘银萍; 李悦

    2013-01-01

    Objective To establish a HPLC - MS/MS method for determining colistin and levofloxaein in broth simultaneously. Methods After the sample pretreated with solid - phase extraction ( SPE) , colistin and levofloxaein were separated on a ZORBAX SB - C18 analytical column by using the mobile phase of acetonitrile(0. 1% formic acid) - water(0. 1% formic acid) (50'- 50) at a flow rate of 0. 3 mL ? min -1'. Results The linear range of colistin and levofloxaein in broth was 0. 48 -9. 60μg ? mL-1. Lower limit of quantification was 0. 48 μg ? mL-1 and precision of intra - day( RSD) was ≤6. 83% , precision of inter - day ( RSD) was ≤9. 85% . Conclusion The method is sensitive, fast and accurate, which is suitable for determination of colistin and levofloxaein in broth.%目的 建立同步测定培养液中多粘菌素E和左氧氟沙星的LC-MS/MS方法.方法 待测样品用固相萃取(SPE)法预处理后,色谱柱为ZORBAXSB-C18柱,流动相为乙腈(0.1%甲酸)-水(0.1%甲酸)(50∶ 50),流速为0.3mL·min-1,用电喷雾离子源(ESI),正离子方式检测,多重反应监测(MRM)扫描.结果 多粘菌素E主要成分多粘菌素A,B和左氧氟沙星的线性范围为0.48 ~9.60 μg·mL-,定量下限为0.48 μg·mL-1,日内精密度(RSD)≤6.83%,日间RSD≤9.85%.绝对回收率为88.06% ~ 104.43%·RSD≤4.15%.结论 本方法专属性好、灵敏、准确、快速,满足了测定的要求.

  4. Growth Kinetics of Listeria monocytogenes in Broth and Beef Frankfurters– Determination of Lag Phase Duration and Exponential Growth Rate under Isothermal Conditions

    Science.gov (United States)

    The objective of this research was to develop a new kinetic model to describe the isothermal growth of microorganisms. The new model was tested with Listeria monocytogenes in broth and frankfurters, and compared with two commonly used models - Baranyi and modified Gompertz models. Bias factor (BF)...

  5. Rapid identification of Salmonella serovars in feces by specific detection of virulence genes, invA and spvC, by an enrichment broth culture-multiplex PCR combination assay.

    Science.gov (United States)

    Chiu, C H; Ou, J T

    1996-10-01

    In order to make a rapid and definite diagnosis of Salmonella enteritis in children, an enrichment broth culture-multiplex PCR combination assay was devised to identify Salmonella serovars directly from fecal samples. Two pairs of oligonucleotide primers were prepared according to the sequences of the chromosomal invA and plasmid spvC genes. PCR with these two primers would produce either one amplicon (from the invA gene) or two amplicons (from the invA and spvC genes), depending on whether or not the Salmonella bacteria contained a virulence plasmid. The fecal sample was diluted 10- to 20-fold into gram-negative enrichment broth and incubated to eliminate inhibitory compounds and also to allow selective enrichment of the bacteria. One or two amplicons were obtained, the expected result if Salmonella bacteria were present. The detection limit of this PCR was about 200 bacteria per reaction mixture. The primers were specific, as no amplification products were obtained with 18 species and 22 isolates of non-Salmonella bacteria tested which could be present in the feces or cause contamination. In contrast, when 23 commonly seen Salmonella serovars (38 isolates) were tested, all were shown to carry the invA gene and seven concomitantly harbored the spvC gene of the virulence plasmid. This assay was applied to the diagnosis of Salmonella enteritis in 57 children who were suffering from mucoid and/or bloody diarrhea. Of the 57 children, 38 were PCR positive and 22 were culture positive. There were two culture-positive samples that were not detected by PCR. Thus, this PCR assay showed an efficiency of 95% (38 of 40), which is much higher than the 60% (24 of 40) by culture alone. Not only is this method more sensitive, rapid, and efficient but it will cause only an incremental increase in the cost of stool processing, since enrichment cultivation of fecal samples from diarrheal patients using gram-negative enrichment broth is a routine practice for identification in many

  6. Identification of Gram-Negative Bacteria and Genetic Resistance Determinants from Positive Blood Culture Broths by Use of the Verigene Gram-Negative Blood Culture Multiplex Microarray-Based Molecular Assay.

    Science.gov (United States)

    Ledeboer, Nathan A; Lopansri, Bert K; Dhiman, Neelam; Cavagnolo, Robert; Carroll, Karen C; Granato, Paul; Thomson, Richard; Butler-Wu, Susan M; Berger, Heather; Samuel, Linoj; Pancholi, Preeti; Swyers, Lettie; Hansen, Glen T; Tran, Nam K; Polage, Christopher R; Thomson, Kenneth S; Hanson, Nancy D; Winegar, Richard; Buchan, Blake W

    2015-08-01

    Bloodstream infection is a serious condition associated with significant morbidity and mortality. The outcome of these infections can be positively affected by the early implementation of effective antibiotic therapy based on the identification of the infecting organism and genetic markers associated with antibiotic resistance. In this study, we evaluated the microarray-based Verigene Gram-negative blood culture (BC-GN) assay in the identification of 8 genus or species targets and 6 genetic resistance determinants in positive blood culture broths. A total of 1,847 blood cultures containing Gram-negative organisms were tested using the BC-GN assay. This comprised 729 prospective fresh, 781 prospective or retrospective frozen, and 337 simulated cultures representing 7 types of aerobic culture media. The results were compared to those with standard bacterial culture and biochemical identification with nucleic acid sequence confirmation of the resistance determinants. Among monomicrobial cultures, the positive percent agreement (PPA) of the BC-GN assay with the reference method was as follows; Escherichia coli, 100%; Klebsiella pneumoniae, 92.9%; Klebsiella oxytoca, 95.5%; Enterobacter spp., 99.3%; Pseudomonas aeruginosa, 98.9%; Proteus spp., 100%; Acinetobacter spp., 98.4%; and Citrobacter spp., 100%. All organism identification targets demonstrated >99.5% negative percent agreement (NPA) with the reference method. Of note, 25/26 cultures containing K. pneumoniae that were reported as not detected by the BC-GN assay were subsequently identified as Klebsiella variicola. The PPA for identification of resistance determinants was as follows; blaCTX-M, 98.9%; blaKPC, 100%; blaNDM, 96.2%; blaOXA, 94.3%; blaVIM, 100%; and blaIMP, 100%. All resistance determinant targets demonstrated >99.9% NPA. Among polymicrobial specimens, the BC-GN assay correctly identified at least one organism in 95.4% of the broths and correctly identified all organisms present in 54.5% of the broths

  7. 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

  8. 蛹虫草菌株发酵液和菌丝提取物的抑菌活性初探%Studies on Antibacterial Activities of Fermentation Broth and Mycelia Extraction of Cordyceps militaris

    Institute of Scientific and Technical Information of China (English)

    韩燕峰; 张延威; 董旋; 黄玉; 梁宗琦

    2012-01-01

    Fermentation broth and mycelia extraction of Cordyceps militaris in different fermentative days were explored for their antibacterial activities. For the three methods to test the antibacterial effect, the results showed that filter paper method was the best, followed by flower mud column, the worst was sponge column. The inhibition effect of mycelia extraction on both bacteria was stronger than that of fermentation broth; and the inhibition effect of both materials on Escherichia coli was stronger than that on Staphylococcus caireus.%研究蛹虫草(Cordyceps militaris)的发酵液和菌丝提取物的抑菌效果,为蛹虫草抑菌活性物质的开发利用提供基础资料.采用滤纸柱、海绵柱和花泥柱3种方法检测其抑菌效果,结果表明蛹虫草发酵液及菌丝提取物对大肠杆菌(Escherichia coli和金黄色葡萄球菌(Staphylococcus aureus)均有一定抑制作用,其中菌丝提取物抑菌作用较强;对大肠杆菌的抑制强于对金黄色葡萄球菌的抑制.抑菌效果检测方法以滤纸柱法检测效果较好,花泥柱法次之,海绵柱法较差.

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

    Science.gov (United States)

    Sathiya, C. K.; Akilandeswari, S.

    2014-07-01

    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.

  10. 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

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

    Institute of Scientific and Technical Information of China (English)

    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 behavior 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.

  12. The use of Macronet resins to recover gamma-decalactone produced by Rhodotorula aurantiaca from the culture broth.

    Science.gov (United States)

    Alchihab, Mohamed; Aldric, Jean-Marc; Aguedo, Mario; Destain, Jacqueline; Wathelet, Jean-Paul; Thonart, Philippe

    2010-02-01

    During the biotransformation of castor oil into gamma-decalactone, R. aurantiaca produced both the lactone form and its precursor (4-hydroxydecanoic acid). After six days of culture, a maximum yield of gamma-decalactone of 6.5 g/l was obtained. The parameters of gamma-decalactone adsorption on three Macronet resins (MN-202, MN-102 and MN-100) were investigated in water. Adsorption isotherms of gamma-decalactone for the three Macronet resins were linear. The trapping of gamma-decalactone produced by R. aurantiaca on these resins was then carried out. gamma-Decalactone was effectively retained by all the studied Macronet resins. The resin MN-202 trapped gamma-decalactone more efficiently than MN-102 and MN-100. The percentages of gamma-decalactone adsorbed on the resins MN-202, MN-102 and MN-100 were, respectively, 85, 75 and 81%, whereas around 70% of the adsorbed gamma-decalactone was then desorbed. We propose an industrial process that uses Macronet resins to extract gamma-decalactone from culture broth of R. aurantiaca. PMID:19902280

  13. 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.

  14. 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.

  15. Fate of Alicyclobacillus spp. in enrichment broth and in juice concentrates.

    Science.gov (United States)

    Oteiza, Juan Martin; Soto, Silvina; Alvarenga, Verônica O; Sant'Ana, Anderson S; Gianuzzi, Leda

    2015-10-01

    In this study, the fate of Alicyclobacillus acidoterrestris spores in different types of juice concentrates stored under different conditions was investigated. In addition, the impact of dilution procedures during the enrichment step for the detection of Alicyclobacillus in lemon juice concentrates was studied. Pear, red grape, mango, tangerine, carrot and lemon juice concentrates (50-69.4°Brix, pH1.7-4.3) were inoculated with A. acidoterrestris spores (10(3) spore/mL) and stored at 4 °C and 20 °C, after which the spores were counted at 0, 2, 5, 9, 17, 21, 28, 36, 43, and 50 days. No significant differences in the number of Alicyclobacillus spores were observed at storage temperatures of 4 °C and 20 °C (p>0.05). The results also indicated that the number of spores of A. acidoterrestris remained stable in all types of juice concentrates during the storage period, except in lemon juice concentrate. In lemon juice concentrate, a decline in A. acidoterrestris spore populations of 0.3-0.8 log CFU/mL was observed within 5-10 days of storage. The decline in A. acidoterrestris spore populations was more pronounced in cloudy lemon juice concentrate, which contained higher concentrations of flavonoids (mainly eriocitrin and hesperidin) than clarified lemon juice concentrate. It was also found that dilution of lemon juice concentrate samples in the proportion of 1:19 allowed the germination of A. acidoterrestris spores and the growth of populations of up to 10(7) CFU/mL. In contrast, the proportion (1:9) recommended in internationally recognized methods led to a reduction in the population of this microorganism that would yield false negative results. Data presented in this study demonstrated that Alicyclobacillus spores remain stable in most juice concentrates during storage, but that natural antimicrobial compounds present in some of them may decrease spore counts and inhibit their recovery by detection procedures.

  16. 蜜环菌发酵液中5-羟甲基糠醛提取工艺优化%Optimization of Extracting Process of 5-Hydroxymethylfurfural from Armillaria mellea Fermentation Broth

    Institute of Scientific and Technical Information of China (English)

    陈楠; 焦连庆; 郑毅男; 于敏; 刘晓杰

    2012-01-01

    以蜜环菌发酵液为原料,通过正交试验优选5-羟甲基糠醛的提取工艺.超声提取蜜环菌发酵液中5-羟甲基糠醛,运用高效液相色谱法测定其含量,并用L9(33)正交试验设计,考察提取溶剂量(mLg)、提取时间、提取次数对提取率的影响.蜜环菌发酵液中5-羟甲基糠醛的最佳提取条件为:提取溶剂量6倍量、提取时间20min、提取次数2次.在最佳提取条件下,5-羟甲基糠醛提取率为6.12%.%The orthogonal experimental design method was used to optimize the extracting process of 5-Hydroxymethylfurfural (5-HMF) in the sample of A rmillaria mellea fermentation broth. 5-HMF was extracted by supersonic wave from Armillaria mellea fermentation broth. Then the content of 5-HMF was determined by high performance liquid chromatography. The L, (3s) orthogonal experimental design was used to study the influence of different dosage of extraction solvent (mL: g), extraction time, and the number of extraction on the extraction rate of 5-HMF. The optimum extraction condition: the dosage of extraction solvent was 6 times, extraction time was 20 min, and the number of extraction times was 2. 5-HMF's extraction rate was 6.12% in the best extraction conditions.

  17. 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. PMID:23377262

  18. Chemical Analysis of a "Miller-Type" Complex Prebiotic Broth. Part I: Chemical Diversity, Oxygen and Nitrogen Based Polymers

    Science.gov (United States)

    Wollrab, Eva; Scherer, Sabrina; Aubriet, Frédéric; Carré, Vincent; Carlomagno, Teresa; Codutti, Luca; Ott, Albrecht

    2016-06-01

    In a famous experiment Stanley Miller showed that a large number of organic substances can emerge from sparking a mixture of methane, ammonia and hydrogen in the presence of water (Miller, Science 117:528-529, 1953). Among these substances Miller identified different amino acids, and he concluded that prebiotic events may well have produced many of Life's molecular building blocks. There have been many variants of the original experiment since, including different gas mixtures (Miller, J Am Chem Soc 77:2351-2361, 1955; Oró Nature 197:862-867, 1963; Schlesinger and Miller, J Mol Evol 19:376-382, 1983; Miyakawa et al., Proc Natl Acad Sci 99:14,628-14,631, 2002). Recently some of Miller's remaining original samples were analyzed with modern equipment (Johnson et al. Science 322:404-404, 2008; Parker et al. Proc Natl Acad Sci 108:5526-5531, 2011) and a total of 23 racemic amino acids were identified. To give an overview of the chemical variety of a possible prebiotic broth, here we analyze a "Miller type" experiment using state of the art mass spectrometry and NMR spectroscopy. We identify substances of a wide range of saturation, which can be hydrophilic, hydrophobic or amphiphilic in nature. Often the molecules contain heteroatoms, with amines and amides being prominent classes of molecule. In some samples we detect ethylene glycol based polymers. Their formation in water requires the presence of a catalyst. Contrary to expectations, we cannot identify any preferred reaction product. The capacity to spontaneously produce this extremely high degree of molecular variety in a very simple experiment is a remarkable feature of organic chemistry and possibly prerequisite for Life to emerge. It remains a future task to uncover how dedicated, organized chemical reaction pathways may have arisen from this degree of complexity.

  19. Determination of Amino Acids in Cell Culture and Fermentation Broth Media Using Anion-Exchange Chromatography with Integrated Pulsed Amperometric Detection

    OpenAIRE

    Hanko, Valoran P.; Heckenberg, Andrea; Rohrer, Jeffrey S.

    2004-01-01

    Anion-exchange chromatography with integrated pulsed amperometric detection (AE-IPAD) separates and directly detects amino acids, carbohydrates, alditols, and glycols in the same injection without pre- or post-column derivatization. These separations use a combination of NaOH and NaOH/sodium acetate eluents. We previously published the successful use of this technique, also known as AAA-Direct, to determine free amino acids in cell culture and fermentation broth media. We showed that retentio...

  20. Presumptive identification of Clostridium difficile by detection of p-cresol in prepared peptone yeast glucose broth supplemented with p-hydroxyphenylacetic acid.

    OpenAIRE

    Sivsammye, G; Sims, H V

    1990-01-01

    Prereduced, anaerobically sterilized peptone yeast glucose broth was supplemented with p-hydroxyphenylacetic acid and used for the presumptive identification of Clostridium difficile. Two hundred eighty-two organisms were grown in this medium for 18 h and tested for p-cresol production by gas-liquid chromatography. All 49 stock and reference strains of C. difficile and 19 organisms confirmed as C. difficile produced p-cresol. p-Cresol was not produced by 53 negative control or 161 test organi...

  1. Evaluation of the Content of Lead, Cadmium, Mercury, Arsenic, Tin, Copper and Zinc during the Production Process Flow of Tomato Broth

    Directory of Open Access Journals (Sweden)

    Corina Andrei

    2013-11-01

    Full Text Available Heavy metals are among the largest contaminants of food products. Once metals are present in vegetables, their concentrations are rarely modified by industrial processing techniques, although in some cases washing may decrease the metal content. The main objective of this study was to quantify the effect of industrial processing on the content of lead, cadmium, mercury, arsenic, tin, copper and zinc in tomatoes and products resulting on flow technology of tomato broth. For the determination of essential elements and/or potentially toxic was use atomic absorption spectrometry. The analytical results for quantitative evaluation the concentrations of the investigated elements on the samples of tomatoes taken from the technological process of the production of tomato broth indicated the presence of Pb, Cd, Cu and Zn but with a level of concentration that significantly decreased in the finished product and the absence of metals Hg and As in all investigated samples. Effect of industrial processing on the content of tin in tomato samples analyzed was characterized by fluctuations in the residual content that led to a significant increase in concentration of 0.100 ± 0.041 mg kg-1 (tomatoes - unprocessed to 0.200 ± 0.041 mg kg-1 (tomato broth.

  2. Effects of broth culture filtrate protein of VacA+ Helicobacter pylori on the proliferation and apoptosis of gastric epithelial cells

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yu-qing; GUO Tao; QIAN Jia-ming

    2013-01-01

    Background Infection with Helicobacterpylori (H.pylori) may lead to chronic inflammation of the stomach epithelium,mucosal atrophy,imbalance of proliferation and apoptosis of epithelial cells; resulting in chronic gastritis,peptic ulcer,gastric cancer,and many other clinical outcomes.Why and how H.pylorus leads to gastric cancer is not clear yet.Through in vitro experiments,this study evaluated the effects of broth culture filtrate protein (BCF-P) from the supernatant of liquid culture media of H.pylori on proliferation and apoptosis of immortalized human gastric epithelial cell lines (GES-1) and gastric cancer cell lines (AGS).Methods For the study,GES-1 and AGS cell lines mix with BCF-P and epidermal growth factor (EGF).MTT assay and flow cytometry (FCM) determined the levels of proliferation and apoptosis.Detected expression levels of cyclooxygenase-2 (COX-2) and Fas mRNA by reverse transcription (RT)-PCR.Also did analysis of the effects of BCF-P on epidermal growth factor receptor (EGFR) tyrosine kinase activity of GES-1 and AGS cells by non-radioactive enzyme-linked assay.The Student's t test and one-way analysis of variance (ANOVA) were used for statistical analysis.Results BCF-P inhibited proliferation of GES-1 and AGS cells in a concentration-dependent manner.The inhibition rates are respectively 68.7% in AGS and 61.4% in GES-1.With the same dose and time for inhibiting the proliferation,BCF-P failed to induce apoptosis of GES-1 and AGS cells.Effects of BCF-P reduced the expression of Fas mRNA of GES-1 and AGS cells (P <0.05).This is consistent with the effects of EGF.BCF-P reduced the expression of COX-2mRNA of AGS cells (P <0.05).This is opposite to the effects of EGF (P <0.05).Effects of BCF-P improved more than three times the EGFR tyrosine kinase activity of GES-1 and AGS cells.Conclusions BCF-P inhibited the proliferation of AGS and GES-1 cells in vitro,unrelated to apoptosis.Effects of BCF-P on gastric epithelial cells in vitro are not

  3. Combined antimicrobial susceptibility test against pan-drug-resistant Acinetobacter baumannii with E-test and microdilution checkerboard assay%应用E-test法、肉汤微量稀释棋盘法检测泛耐药鲍曼不动杆菌的试验

    Institute of Scientific and Technical Information of China (English)

    王铁山; 苏建荣

    2013-01-01

    Objective To evaluate the activity of antibiotics against pan-drug-resistant (PDR) Acinetobacter baumannii by combination antimicrobial susceptibility test in viro with epsilometric methods (Etest method) and microdilution checkerboard (CB method),and to detect a good correlation between timekill curve with the above mentioned two assays.Methods Thirty-one clinical isolates of PDR Acinetobacter baumannii were selected for mono and combination antimicrobial susceptibility test in vitro by E-test and CB method,then a comparison was conducted between the test results and the time-kill curve.Mono drugs involved tigecycline,colistin,imipenem and amikacin,and combinations involved two of drugs above,and three drugs involved imipenem/tigecycline,plus amikacin combination.Results Synergistic effect was detected in imipenem plus colistin and tigecycline plus imipenem combination.A high comparability was revealed between the E-test method with antimicrobial drugs added into the culture medium and the time-kill curves.Synergy in the combination of imipenem/tigecycline,plus amikacin was detected by the CB method and time-kill curves.Conclusion The results showed that the effect of specific combination of antibiotics against PDR Acinetobacter baumannii could be predicted by testing their synergistic effect with combination antimicrobial susceptibility test.%目的 比较E-test法和肉汤微量稀释棋盘法(CB法)检测体外联合药敏试验并与时间杀菌曲线对比的观察.方法 选择31株泛耐药(PDR)鲍曼不动杆菌临床株进行体外试验,分为替加环素、可立其丁、亚胺培南、阿米卡星单用和两药组合,亚胺培南+替加环素+阿米卡星三药组合也由CB法测试.这些测试的结果与时间杀菌曲线进行比较.结果 亚胺培南+可立其丁、替加环素+亚胺培南能检测到协同作用.培养基中加入抗菌药物的E-test法联合药敏试验与时间杀菌曲线更具有可比性.在三药组合中由CB法和

  4. Acetic Acid Production by an Electrodialysis Fermentation Method with a Computerized Control System

    OpenAIRE

    Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

    1988-01-01

    In acetic acid fermentation by Acetobacter aceti, the acetic acid produced inhibits the production of acetic acid by this microorganism. To alleviate this inhibitory effect, we developed an electrodialysis fermentation method such that acetic acid is continuously removed from the broth. The fermentation unit has a computerized system for the control of the pH and the concentration of ethanol in the fermentation broth. The electrodialysis fermentation system resulted in improved cell growth an...

  5. Determination of Poly(malic acid) in Fermentation Broth by RP-HPLC%反向高效液相色谱测定发酵液中的聚苹果酸

    Institute of Scientific and Technical Information of China (English)

    乔长晟; 姜少丽; 马正旺; 李政; 楼鹏

    2012-01-01

    For the detection of poly (malic acid) fermentation broth, a reversed phase high performance liquid chromatography method was developed The samples was analyzed on a column of AlltimaTMC18 (4.6 mm× 150 mm, 4 um) with a mixture of acetonitrik and 0.025 mol/L KH2PO4 buffer (pH 2.5) (5:95, v:v) used as mobile phase at the flow rate of l.0mL/min. The detection wavelength was 210 nm; the column temperature was 25 ℃ and the volum of injection was 5 μL. Before sampling, the fermentation broth was centrifuged to remove fungis, added with organic solvent to remove polysaccharide and hydrolysed. L-malic acid were completely separated and determined in 3 minutes. The recovery and relative standard deviation (RSD, n=3) of L-malic acid by RP-HPLC method were 98.70%~100.65%, and 0.40%~1.11%, respectively. The recovery and relative standard deviation (RSD, n=3) of L-malic acid by L-malic acid kit were 96.70%~97.23% and 0.57%-1.19%, respectively. The method was proved to be a effective way to determine the poly (malic acid) in fermentation broth.%采用高效液相色谱柱AlltimaTM C18 (4.6 mm× 150 mm,4μm)上定量测定发酵生产的聚苹果酸,流动相为乙腈和0.025 mol/L磷酸二氢钾混合溶液(磷酸调pH 2.5)(V∶V=5∶ 95),流速1.0 mL/min,检测波长210 nm,柱温25℃,进样量5μL.发酵液经离心除菌体、纯沉除多糖、水解处理后进样,可以将其中的L苹果酸完全分离定量.采用液相方法的回收率为98.70%-100.65%,RSD为0.4-1.11%.采用试剂盒的方法的回收率为96.7~97.23%,RSD为0.57~1.19%.可见,液相的精确度和试剂盒相差不大.但液相的价格相对比试剂盒要便宜很多,说明该法是测定发酵液中聚苹果酸的一种很有效的方法.

  6. 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.

  7. 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.

  8. 发酵液作为EBPR碳源的动力学模拟%Kinetic Simulation of Enhanced Biological Phosphorus Removal with Fermentation Broth as Carbon Source

    Institute of Scientific and Technical Information of China (English)

    张超; 陈银广

    2013-01-01

    发酵液是一种优质的碳源,能够提高生物除磷系统(EBPR)的除磷效果.采用基于碳源代谢的修正ASM2模型,能够较好地模拟发酵液作为EBPR碳源的动力学变化规律.发酵液作为EBPR唯一碳源时,系统中的异养菌不仅不对聚磷菌(PAO)的生长构成竞争关系,反而促进PAO的生长.发酵液作为实际污水的补充碳源时,优化了污水中的碳源组成,创造了有利于聚磷菌生长的环境,使EBPR中聚磷菌达到微生物总量的40%以上,比实际污水作为碳源的EBPR中的PAO含量提高了3.3倍.%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.

  9. Effect of an exo-polysaccharide from the culture broth of Hericium erinaceus on enhancement of growth and differentiation of rat adrenal nerve cells

    OpenAIRE

    Park, Young Shik; Lee, Hyun Soo; Won, Moo Ho; Lee, Jin Ha; Lee, Shin Young; Lee, Hyeon Yong

    2002-01-01

    It was found that an exo-biopolymer (M.W. 1,000,000, molar ratio of 1.5:1.7:1.2:0.6:0.9, glucose:galactose:xylose:mannose:fructose, purity 99%) purified from the liquid culture broth of Hericium erinaceus mycelium enhanced the growth of rat adrenal nerve cells. The polymer also improved the extension of the neurites of PC12 cell. Its efficacy was found to be higher than those from known nerve growth factors such as Nerve Growth Factor (NGF) and Brain-Derived Nerve Factor (BDNF). The effect of...

  10. Antifungal activity of the essential oils of wild-growing Mentha piperita L and Mentha spicata L from the Mariovo region, Republic of Macedonia

    OpenAIRE

    Kostik, Vesna; Bauer, Biljana

    2015-01-01

    The antifungal activity of the essential oils isolated by hydro-distillation from the leaves of wild growing Mentha piperita and Mentha spicata (Lamiaceae) at the region of Mariovo, Republic of Macedonia was tested by disc diffusion method and the micro-dilution broth method (MIC) against six plant pathogenic fungi: Alternaria alternate Alternaria solani, Aspergillus flavus, Aspergillus niger, Fusarium solani and Rhizopus solani. The results from the disc diffusion method followed by MIC indi...

  11. 发酵液中1,3-丙二醇分离提取的研究进展%Process of separating and purifying 1,3-propanediol from fermentation broth

    Institute of Scientific and Technical Information of China (English)

    孙启梅; 王领民; 王崇辉; 高大成

    2015-01-01

    1,3-propanediol is the main raw material to synthesize PTT. Using glycerol to produce 1,3-propanediol by biological processes is characteristic of green chemistry. Due to the strong polarity of 1,3-propanediol and complex composition of fermentation broth,1,3-propanediol has a low yield and its quality cannot match the requirements for synthesizing high performance PTT. Therefore,the separation and purification of 1,3-propanediol from fermentation broth become the key technology for biosynthesis. There are several steps to realize it,including pretreatment of fermentation broth, desalination,concentration and purification. In this paper,the main methods for separating 1,3-propanediol were discussed. It can be described as the following: centrifugation,filtration and flocculation process can be applied to remove macromolecular substances,and then 1,3-propanediol can be concentrated and purified by icon exchange,electrodialysis,aqueous two-phase extraction,ethanol precipitation to desalt,adopting distillation,extraction and adsorption. It can also be achieved by one or two above processes combined together. There still exist some problems in the whole separation. Each process needs continuously optimized to obtain an economical and efficient separation route. This is the key technology to realize large-scale production of 1,3-propanediol using biological process.%1,3-丙二醇是合成聚乳酸的主要原料,以甘油为底物的生物法制备1,3-丙二醇是以绿色化学为特征的技术。但1,3-丙二醇极性很强、微生物发酵液成分较复杂,产品收率偏低,质量难符合制备高性能聚对苯二甲酸丙二醇酯的要求,故1,3-丙二醇的分离提纯成为了生物法合成技术的关键。对于1,3-丙二醇发酵液,提纯过程包括发酵液预处理、脱盐和浓缩提纯。本文讨论了用于1,3-丙二醇提纯的主要技术,包括采用离心、过滤、絮凝脱大分子物质,用离子交换、电渗析、双

  12. Study on L-Valine Efficient Extraction Technology from the Fermentation Broth%从发酵液中高效提取L-缬氨酸的工艺研究

    Institute of Scientific and Technical Information of China (English)

    李新涛; 徐庆阳; 冯宁; 谢希贤; 陈宁

    2011-01-01

    目的:利用有机膜过滤和离子交换法分离提取发酵液中的L-缬氨酸.方法:通过有机膜过滤,除去发酵液中的菌体及蛋白,滤液浓缩结晶获得L-缬氨酸产品,通过离子交换法从结晶母液中回收部分L-缬氨酸.结果:确定了有机微滤膜和超滤膜去除发酵液中菌体蛋白和色素的操作条件;确定了采用离子交换法提取L-缬氨酸的操作条件:选择732强酸性阳离子树脂,料液pH值为3.0左右,用0.4 mol/L的氨水以1.0 mL/min的速度洗脱,L-缬氨酸的收率为89.2%.结论:通过有机膜过滤和离子交换法分离提取发酵液中的L-缬氨酸,可以提高提取收率和产品质量.%Objective: Using organic membrane filtration and ion exchange to extract L-valine from the fermentation broth. Methods: The bacteria and proteins in the fermentation broth were removed through organic membrane filtration, the filtrate was concentrated to obtain L-valine crystal products, the part of L-valine was further extracted from the crystal liquor by ion exchange. Results: The optimum conditions of organism membrane filtration, decolour and abstracton of L-valine were determined. 732 resin was the optimal resin for L-valine abstraction among the different kinds of resins. The optimal conditions of adsorption were as follow: dosage liquor pH3.0, and the elution of L-valine was carried out at the rate of 1.0 mL/min using 0.4 mol/L ammonia water as eluant. The recovery of L-valine was up to 89.2%. Conclution: L-valine extraction yield and product quality was improved by the way of organic membrane filtration and ion exchange.

  13. Quantitative Determination of Dihydroxyacetone and Glycerol in the Fermentation Broth by HPLC%HPLC检测发酵液中二羟基丙酮和甘油的含量

    Institute of Scientific and Technical Information of China (English)

    谢光蓉

    2013-01-01

    High performance liquid chromatography (HPLC) was applied to determinate dihydroxyacetone (DHA) and glycerol in the fermentation broth respectively. The mobile phase is composed of acetonitrile-water (85∶15, V∶V). The analytes were separated on a Hedera-NH2 column with at a flow rate of 1mL/min. DHA was detected by UV detector at 271nm and glycerol was detected by refractometer. The linearity range for the determination of DHA was 2.00-12.00mg/mL with a correlation coefficient (r) of 0.9996. The linearity range for the determination of glycerol was 0.1-1.0mg/mL with a correlation coefficient (r) of 0.9998. The methods were applicable for DHA and glycerol determination in the fermentation process without interference from other constitutes in the fermentation broth.%  应用高效液相色谱法检测发酵过程中发酵产物二羟基丙酮和底物甘油浓度。在流动相乙腈、纯净水的比例为85∶15(v∶v),流速为1mL/min,色谱柱为Hedera-NH2的条件下,用紫外检测器在271nm处检测DHA,用示差折光检测器检测甘油。高效液相色谱法检测DHA的线性范围为2.0-12.0mg/mL,相关系数(r)为0.9996,检测甘油的线性范围为0.1-1.0mg/mL,相关系数(r)为0.9998。该方法应用于二羟基丙酮发酵过程中底物和产物的检测,该方法不受培养基中不同碳源(葡萄糖、蔗糖、山梨醇、乳糖、甘油),不同氮源(蛋白胨、酵母膏、酵母粉、营养肉汤)以及菌体未完全利用的培养基成分、菌体生长过程中产生的其它代谢产物的影响,该方法具有较好的通用性。

  14. 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. PMID:24034431

  15. Evaluation of Methods To Increase the Sensitivity and Timeliness of Detection of Streptococcus agalactiae in Pregnant Women

    OpenAIRE

    Overman, Sue B.; Eley, Douglas D.; Jacobs, Barry E.; Ribes, Julie A.

    2002-01-01

    Direct culture of rectovaginal specimens on Granada agar was compared to culture on sheep blood agar plate (SBAP) and AccuProbe detection of group B streptococcus from overnight LIM broth enhancement cultures (LIM-SBAP). Both broth-enhanced methods demonstrated excellent sensitivity (97.5% for LIM-SBAP and 93.5% for AccuProbe), while Granada agar demonstrated a sensitivity of only 40.3%.

  16. Antifungal activity of triterpenoid isolated from Azima tetracantha leaves.

    OpenAIRE

    Duraipandiyan, V.; M Gnanasekar; S Ignacimuthu

    2010-01-01

    The present study was designed to evaluate the antifungal activity of Azima tetracantha extracts and isolated compound (friedelin) against fungi. Antifungal activity was carried out using broth microdilution method and fractions were collected using (silica gel) column chromatography. The antifungal activity of Azima tetracantha crude extracts and isolated compound (friedelin) were evaluated using the micro dilution method. Hexane extract showed some antifungal activity. The compound also exh...

  17. Synergistic effect of xylitol and ursolic acid combination on oral biofilms

    OpenAIRE

    Zou, Yunyun; Lee, Yoon; Huh, Jinyoung; Park, Jeong-Won

    2014-01-01

    Objectives This study was designed to evaluate the synergistic antibacterial effect of xylitol and ursolic acid (UA) against oral biofilms in vitro. Materials and Methods S. mutans UA 159 (wild type), S. mutans KCOM 1207, KCOM 1128 and S. sobrinus ATCC 33478 were used. The susceptibility of S. mutans to UA and xylitol was evaluated using a broth microdilution method. Based on the results, combined susceptibility was evaluated using optimal inhibitory combinations (OIC), optimal bactericidal c...

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

    Directory of Open Access Journals (Sweden)

    Aziz Fassouane Fassouane

    2004-08-01

    Full Text Available Abstract: (--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.

  19. Pimenta pseudocaryophyllus inhibits virulence factors and promotes metabolic changes in Candida yeast

    OpenAIRE

    2014-01-01

    Introduction This is the first study to examine the in vitro susceptibility and the expression of virulence factors in Candida species in the presence of Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae), a Brazilian plant known as paucravo. Additionally, the mechanisms of action of the crude ethanol extract and the ethyl acetate and aqueous fractions of this plant were investigated. Methods The in vitro susceptibility of Candida was tested using the broth microdilution method, wh...

  20. Rapid detection of polymyxin-resistant Enterobacteriaceae from blood cultures

    OpenAIRE

    Jayol, Aurélie; Dubois, Véronique; Poirel, Laurent; Nordmann, Patrice

    2016-01-01

    Enterobacterial strains resistant to polymyxins are increasingly reported worldwide. Conventional methods for detection of colistin-resistant isolates such as broth microdilution remain time-consuming (24 to 48 h), and methods such as disc diffusion and E-test are not reliable. Recently, the Rapid Polymyxin NP test was developed for a rapid identification of polymyxin-resistant Enterobacteriaceae. This test is based on the detection of glucose metabolism related to bacterial growth in th...

  1. Clinical and economic evaluation of BBL CHROMagar Salmonella (CHROMSal) versus subculture after selenite broth enrichment to CHROMSal and Hektoen enteric agars to detect enteric Salmonella in a large regional microbiology laboratory.

    Science.gov (United States)

    Church, Deirdre L; Emshey, Diana; Lloyd, Tracie; Pitout, Johann

    2010-09-01

    Stool culture for enteric pathogens is one of the most labor-intensive clinical microbiology procedures. Direct plating of stool to BBL CHROMagar Salmonella (CHROMSal) (BD Diagnostics, Sparks, MD) versus subculture after selenite broth enrichment (Sel) to CHROMSal (Sel-CHROMSal) and Hektoen enteric agar (Sel-Hek) (PML Microbiologicals, Eugene, OR) to detect Salmonella were compared. The number of colony picks and biochemical/serotyping tests per plate was recorded. A cost comparison was done. Fifty-one of 2999 (1.7%) stools yielded Salmonella sp., and 80% of isolates grew on CHROMSal by 24 h. CHROMSal demonstrated much less false-positive growth compared to Sel-Hek (P < 0.0001), which reduced biochemical and serotyping tests by 85% and 20%, respectively. Sel-CHROMSal and CHROMSal versus Sel-Hek improved enteric Salmonella detection when compared to a true positive "gold standard" (i.e., recovery by any culture method) with a sensitivity, specificity, positive predictive value, and negative predictive value of 100% and 94.12%, 100% and 99.97%, 100% and 97.96%, and 100% and 99.90%, respectively. CHROMSal use would result in substantial cost and labor savings.

  2. Recovery of Succinate from Fermentation Broth Based on Complexation Extraction Process%络合萃取法提取发酵液中丁二酸铵

    Institute of Scientific and Technical Information of China (English)

    古博华; 郑璞

    2013-01-01

    To improve the extraction yield of succinic acid produced by microbial fermentation,trioctylamine/octanol was used as extraction agent to extract succinate from fermentation broth.The pre-treatment of fermentation broth as well as the preparation of succinic acid ammonium using ammonia in the re-extraction were investigated.The results show that the rate of succinic acid extraction from fermentation broth pre-treated by cation exchange resin reached 91.3%,which was higher than that by sulfuric acid.Ammonia was an excellent re-extraction agent and the extractant (trioctylamine /octano) could be reused.When the extractant was recycled five times,the average rate of extraction and that of re-extraction were 90.4% and 94.9%,respectively,showing no obvious decline.%为提高微生物发酵法生产丁二酸的产品提取收率,用三辛胺/正辛醇体系对发酵液进行络合萃取.比较硫酸和阳离子交换树脂两种前处理发酵液方式对络合萃取丁二酸的影响以及用氨水反萃制备丁二酸铵.结果表明,通过阳离子交换树脂前处理发酵液,三辛胺/正辛醇体系对丁二酸的萃取率高于硫酸前处理,达到91.3%;氨水是一种优良反萃剂;萃取剂重复使用5次,平均萃取率为90.4%,平均反萃率为94.9%,且萃取率和反萃率未见明显下降.

  3. Membrane Separation Process of Oxytetracycline Fermentation Broth with Magnetization%磁场强化膜分离土霉素发酵液工艺研究

    Institute of Scientific and Technical Information of China (English)

    王亚卿

    2012-01-01

    The oxytetracycline filtered broth by plate and framefilter was purified and concentrated with membrane separation techniques in magnetic field.Experiment results indicate that ultrafiltration membrane PES20 and nanofiltration membrane NF270 separation properties is better effect in 0.4 T,and the production quality of oxytetracycline increased compared with no magnetization treatment process or the original technology.%引入磁场强化膜分离技术对板框过滤后的土霉素发酵液进行提纯和浓缩,研究结果表明,经0.4T磁段磁场强化后,PES20超滤膜及NF270纳滤分离性能均表现出较佳的正效应,土霉素产品质量较无磁场作用及原工艺有所提高。

  4. 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

  5. Inhibition of Listeria monocytogenes and Escherichia coli O157:H7 in liquid broth medium and during processing of fermented sausage using autochthonous starter cultures.

    Science.gov (United States)

    Pragalaki, T; Bloukas, J G; Kotzekidou, P

    2013-11-01

    The antimicrobial effect of two autochthonous starter cultures of Lactobacillus sakei was evaluated in vitro (in liquid broth medium) and in situ assays. The inactivation of foodborne pathogens Listeria monocytogenes (serotype 4ab No 10) and Escherichia coli O157:H7 ATCC 43888 was investigated during the production of fermented sausage according to a typical Greek recipe using L. sakei strains as starter cultures. The inactivation kinetics were modeled using GInaFiT, a freeware tool to assess microbial survival curves. By the end of the ripening period, the inhibition of L. monocytogenes was significant in treatments with L. sakei 8416 and L. sakei 4413 compared to the control treatment. A 2.2-log reduction of the population of E. coli O157:H7 resulted from the autochthonous starter culture L. sakei 4413 during sausage processing. The use of the autochthonous starter cultures constitutes an additional improvement to the microbial safety by reducing foodborne pathogens.

  6. Separation of clavulanic acid from fermented broth of amino acids by an aqueous two-phase system and ion-exchange adsorption.

    Science.gov (United States)

    da Silva, Clovis Sacardo; Cuel, Maressa Fabiano; Barreto, Verônica Orlandin; Kwong, Wu Hong; Hokka, Carlos O; Barboza, M

    2012-02-15

    The clavulanic acid is a substance which inhibits the β-lactamases used with penicillins for therapeutic treatment. After the fermentation, by-products of low molecular weight such as amino acids lysine, histidine, proline and tyrosine are present in the fermented broth. To remove these impurities the techniques of extraction by an aqueous two-phase system of 17% polyethylene glycol molecular weight 600 and 15% potassium phosphate were used for a partial purification. A subsequent ion-exchange adsorption was used for the recuperation of the clavulanic acid of the top phase and purification getting a concentration factor of 2 and purification of 100% in relation to the amino acids lysine, histidine, proline and tyrosine.

  7. 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.

  8. Production of laccase by Coriolus versicolor and its application in decolorization of dyestuffs: (Ⅱ) Decolorization of dyes by laccase containing fermentation broth with or without self-immobilized mycelia

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The capability of decolorization for commercial dyes byCoriolus versicolor fermentation broth containing laccase with orwithout immobilized mycelium was evaluated. With cell-freefermentation broth containing laccase, high decolorization ratiowas achieved for acid orange 7, but not for the other dyesconcerned. The immobilized mycelium was proved to be more efficientthan the cell-free system. All the four dyestuffs studied werefound being decolourized with certain extent by immobilizedmycelium. The repeated-batch decolorization was carried out withsatisfactory results. The experimental data showed that thecontinuous decolorization of wastewater from a printing and dyeingindustry was possible by using the self-immobilized C. Versicolor.

  9. Growth of Stressed Strains of Four Non-O157 Shiga Toxin-Producing Escherichia coli Serogroups in Five Enrichment Broths.

    Science.gov (United States)

    Verhaegen, Bavo; De Reu, Koen; Heyndrickx, Marc; Van Damme, Inge; De Zutter, Lieven

    2015-11-01

    The purpose of this study was to evaluate (i) the behavior of several strains of non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups (O26, O103, O111, and O145) exposed to different stress conditions and (ii) the growth dynamics of stressed and nonstressed non-O157 STEC cells in five enrichment media. STEC strains were exposed to acid, cold, and freeze stresses. Lethal and sublethal injuries were determined by plating in parallel on selective and nonselective agar media. Freeze stress (8 days, 20°C) caused the most lethal (95.3% ± 2.5%) injury, as well as the most sublethal (89.1% ± 8.8%) injury in the surviving population. Growth of stressed and nonstressed pure cultures of non-O157 STEC on modified tryptic soy broth, buffered peptone water (BPW), BPW with sodium pyruvate, Brila, and STEC enrichment broth (SEB) was determined using total viable counts. To compare growth capacities, growth after 7 and 24 h of enrichment was measured; lag phases and maximum growth rates were also calculated. In general, growth on BPW resulted in a short lag phase followed by a high maximum growth rate during the enrichment of all tested strains when using all three stress types. Furthermore, BPW ensured the highest STEC count after 7 h of growth. Supplementing the medium with sodium pyruvate did not improve the growth dynamics. The two selective media, Brila and SEB, were less efficient than BPW, but Brila's enrichment performance was remarkably better than that of SEB. This study shows that irrespective of the effect of background flora, BPW is still recommended for resuscitation of non-O157 STEC.

  10. Synthesis and In Vitro Evaluation of New Thiosemicarbazone Derivatives as Potential Antimicrobial Agents

    OpenAIRE

    Zafer Asım Kaplancıklı; Mehlika Dilek Altıntop; Belgin Sever; Zerrin Cantürk; Ahmet Özdemir

    2016-01-01

    In an effort to develop potent antimicrobial agents, new thiosemicarbazone derivatives were synthesized via the reaction of 4-[4-(trifluoromethyl)phenyl]thiosemicarbazide with aromatic aldehydes. The compounds were evaluated for their inhibitory effects on pathogenic bacteria and yeasts using the CLSI broth microdilution method. Microplate Alamar Blue Assay was also carried out to determine the antimycobacterial activities of the compounds against Mycobacterium tuberculosis H37Rv. Among these...

  11. The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives

    OpenAIRE

    Marina Azevedo Souza; Susana Johann; Luciana Alves Rodrigues dos Santos Lima; Fernanda Fraga Campos; Isolda Castro Mendes; Heloisa Beraldo; Elaine Maria de Souza-Fagundes; Patricia Silva Cisalpino; Carlos Augusto Rosa; Tania Maria de Almeida Alves; Nivea Pereira de Sa; Carlos Leomar Zani

    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 thiosemicarbazone an...

  12. The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives

    OpenAIRE

    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...

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

    OpenAIRE

    Ospina Salazar, Daniel Iván; Hoyos Sánchez, Rodrigo Alberto; Fernando OROZCO SÁNCHEZ; Myrtha ARANGO ARTEAGA; Luisa Fernanda GÓMEZ LONDOÑO

    2015-01-01

    In order to assess the antifungal activity of methanolic extracts from neem tree (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. Neem extracts were obtained through methanol-hexane partitioning of mature green leaves and seed oil. Furthermore, high performance liquid chromatography (HPLC) analyses were...

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

    OpenAIRE

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

    2010-01-01

    Abstract Background Hydroxychavicol, isolated from the chloroform extraction of the aqueous leaf extract of Piper betle L., (Piperaceae) was investigated for its antifungal activity against 124 strains of selected fungi. The leaves of this plant have been long in use tropical countries for the preparation of traditional herbal remedies. Methods The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of hydroxychavicol were determined by using broth microdilution ...

  15. Isolierungsraten, Resistenzverhalten und genetische Diversität von Campylobacter aus Tierbeständen und Umwelthabitaten

    OpenAIRE

    Löwenstein, Anna Elisabeth

    2016-01-01

    The aim of the study was to identify potential sources of Campylobacter spp. and their prevalences in Greater Berlin area from November 2011 to June 2013. Samples collected from pet animals, farm animals, wild animals and the environment were investigated by two isolation methods – ISO (according to ISO 10272-1:2006) and the Cape Town protocol. Also the presence of antimicrobial resistance in selected C. jejuni and C. coli isolates was determined by Broth Microdilution assays and isolates ...

  16. Antimicrobial and Antioxidant Activities of Two Endemic Plants from Aksaray in Turkey

    OpenAIRE

    Ozusaglam, Meltem Asan; Darilmaz, Derya Onal; Erzengin, Mahmut; Teksen, Mehtap; Erkul, Seher Karaman

    2013-01-01

    This study was designed to examine the in vitro antimicrobial and antioxidant activities of the methanol, ethanol, water, n-hexane and dicholoromethane extracts of two Allium species (Allium scabriflorum and Allium tchihatschewii) which are endemic for the flora of Turkey. The antimicrobial efficiency of the plant was evaluated according to disc diffusion and microdilution broth methods. The antimicrobial test results showed that the extracts of A. scabriflorum and A. tchihatschewii showed va...

  17. In vitro interactions of antifungal agents and tacrolimus against Aspergillus biofilms.

    Science.gov (United States)

    Gao, Lujuan; Sun, Yi

    2015-11-01

    Aspergillus biofilms were prepared from Aspergillus fumigatus, Aspergillus flavus, and Aspergillus terreus via a 96-well plate-based method, and the combined antifungal activity of tacrolimus with azoles or amphotericin B against Aspergillus biofilms was investigated via a broth microdilution checkerboard technique system. Our results suggest that combinations of tacrolimus with voriconazole or amphotericin B have synergistic inhibitory activity against Aspergillus biofilms. However, combinations of tacrolimus with itraconazole or posaconazole exhibit no synergistic or antagonistic effects.

  18. Characterization of Anticancer, Antimicrobial, Antioxidant Properties and Chemical Compositions of Peperomia Pellucida Leaf Extract

    OpenAIRE

    Desy Fitrya Syamsumir; Julius Yong Fu Siong; Wendy Wee; Lee Seong Wei

    2011-01-01

    Peperomia pellucida leaf extract was characterized for its anticancer, antimicrobial, antioxidant activities, and chemical compositions. Anticancer activity of P. pellucida leaf extract was determined through Colorimetric MTT (tetrazolium) assay against human breast adenocarcinoma (MCF-7) cell line and the antimicrobial property of the plant extract was revealed by using two-fold broth micro-dilution method against 10 bacterial isolates. Antioxidant activity of the plant extract was then char...

  19. In vitro activity of antimicrobial agents against oxacillin resistant staphylococci with special reference to Staphylococcus haemolyticus

    OpenAIRE

    Chaudhury A; Kumar A

    2007-01-01

    One hundred and sixty seven isolates of staphylococci isolated from the inpatients of a tertiary care referral hospital in South India were speciated and activity of oxacillin, glycopeptides, linezolid and quinupristin/dalfopristin against these isolates was tested by broth microdilution method. Of the 114 coagulase negative staphylococci (CoNS), 49.1 % were S. haemolyticus, isolated predominantly from urine (64.6%), while the rest belonged to 11 other species. More than half ...

  20. In vitro study on the antimicrobial effect of hydroalcoholic extracts from Mentha arvensis L. (Lamiaceae) against oral pathogens=Estudo in vitro do efeito antimicrobiano dos extratos hidroalcólicos de Mentha arvensis L. (Lamiaceae) contra patógenos orais

    OpenAIRE

    Rogério Antonio Freitag; Gladis Aver Ribeiro; Patrícia da Silva Nascente; Rosana Serpa; Rafael Guerra Lund; Francisco Augusto Burkert Del Pino

    2012-01-01

    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 hy...

  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

    OpenAIRE

    Francisco Augusto Burkert Del Pino; Gladis Aver Ribeiro; Rogério Antonio Freitag; Patrícia da Silva Nascente; Rosana Serpa; Rafael Guerra Lund

    2012-01-01

    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 hy...

  2. In Vitro Antibacterial, Antifungal, Antibiofilm, Antioxidant, and Anticancer Properties of Isosteviol Isolated from Endangered Medicinal Plant Pittosporum tetraspermum

    OpenAIRE

    Naif Abdullah Al-Dhabi; Mariadhas Valan Arasu; Thankappan Sarasam Rejiniemon

    2015-01-01

    This study aimed to investigate the in vitro antibacterial, antifungal, antibiofilm, antioxidant, and anticancer properties of isosteviol isolated from endangered medicinal plant Pittosporum tetraspermum. Pure compound was obtained and characterized by column chromatography followed by 1H NMR, 13C NMR, IR, and mass spectral analysis. The antimicrobial activities of the compound were assessed by the broth microdilution method and the antioxidant properties were determined using reducing abilit...

  3. Methodological comparisons for antimicrobial resistance surveillance in feedlot cattle

    OpenAIRE

    Katharine M Benedict; Gow, Sheryl P.; Checkley, Sylvia; Booker, Calvin W.; McAllister, Tim A; Morley, Paul S.

    2013-01-01

    Background The purpose of this study was to objectively compare methodological approaches that might be utilized in designing an antimicrobial resistance (AMR) surveillance program in beef feedlot cattle. Specifically, four separate comparisons were made to investigate their potential impact on estimates for prevalence of AMR. These included investigating potential differences between 2 different susceptibility testing methods (broth microdilution and disc diffusion), between 2 different targ...

  4. Antimicrobial, antioxidant, and cytotoxic activities of Bixa orellana Linn

    OpenAIRE

    Ul Islam, S.M. Bakhtiar; Hossain, Khalid; Gomes, Isidore; Gomes, Donald J.; Rahman, Sabita Rezwana; Mohammad S. Rahman; RASHID, MOHAMMAD A.

    2011-01-01

    Bixa orellana Linn., commonly known as "lipstick plant", is used in folk medicines to treat infections of microbial origin as well as coloring agents in food stuffs in the LDCs like Bangladesh. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the warm water extract of leaves of B. orellana were evaluated against 25 multidrug resistant (MDR) clinical isolates and 6 food-borne pathogens using the micro-dilution broth method modified to comply with the N...

  5. Methicillin-Resistant Staphylococcus aureus in Spain: Molecular Epidemiology and Utility of Different Typing Methods ▿ †

    OpenAIRE

    Vindel, Ana; Cuevas, Oscar; Cercenado, Emilia; Marcos, Carmen; Bautista, Verónica; Castellares, Carol; Trincado, Pilar; Boquete, Teresa; Pérez-Vázquez, Maria; Marín, Mercedes; Bouza, Emilio

    2009-01-01

    In a point-prevalence study performed in 145 Spanish hospitals in 2006, we collected 463 isolates of Staphylococcus aureus in a single day. Of these, 135 (29.2%) were methicillin (meticillin)-resistant S. aureus (MRSA) isolates. Susceptibility testing was performed by a microdilution method, and mecA was detected by PCR. The isolates were analyzed by pulsed-field gel electrophoresis (PFGE) after SmaI digestion, staphylococcal chromosomal cassette mec (SCCmec) typing, agr typing, spa typing wi...

  6. Modified ecometric technique (four-quadrant sequential streak) to evaluate Campylobacter enrichment broth proficiency in suppressing background microflora

    Science.gov (United States)

    Ecometric technique is a semi-quantitative scoring method used for quality control of culture media in microbiological laboratories. The technique involves inoculation with defined populations of specific culture onto solid media via a standardized chronological streaking technique, leading to ever-...

  7. 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.

    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 strai

  8. 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 strai

  9. Determination of Enantiomeric Purity for Lactic Acid in Fermentation Broth by Rhizopus Oryzae with High Performance Liquid Chromatography%高效液相色谱法测定米根霉乳酸发酵液中乳酸的光学纯度

    Institute of Scientific and Technical Information of China (English)

    白冬梅; 赵学明; 胡宗定

    2001-01-01

    A procedure for the resolution of DL-lactic acid and th edeterminatio n of D-isomer ratio in L-lactic acid fermentation broth by Rhizopus oryzae is desc ribed. The effects of pH of mobile phase and concentration of chiral mobile pha s e additives on resolution of DL-lactic acid were investigated. The optical is om ers of lactic acid were resolved by RP-HPLC with 2,3,6-tri-O-β-cyc lode xtrin(TM-β-CD) as a chiral mobile phase additive, and C18 column as stationary phase, and detected at wavelength 210 nm. The results sh owed that a correction factor should be introduced into the equation for ca lc ulation of the percentage of D-lactic acid, because the UV absorption of D-lac tic acid and L-lactic acid might not be the same when TM-β-CD was presen t. Quantitation was achieved with external standard method, the average rec overy was 100.4%, and the relative standard deviation was 0.82%. This method can be used for the determination of the percentage of D-isomer in L-lactic a cid fermentation broth by Rhizopus oryzae, and it is simple, rapid and accur ate. T he results showed that the mass fraction of D-isomer in the fermented broth inc reased during the period of storage.%以2,3,6-三甲基-β-环糊精作手性流动相添加剂,C18柱为固定相,考察了流动相的pH和手性流动相添加剂浓度对乳酸对映体分离度的影响,建立了DL-乳酸的拆分定量分析方法。用归一化法分析DL-乳酸时引入了定量校正因子,确定了外标法测定L-乳酸的回归方程、精密度和回收率。测定了米根霉L-乳酸发酵液中D-型异构体的质量分数及其随放置时间的变化情况。

  10. Selective separation of succinic acid from simulated fermentation broth by nanofiltration%纳滤选择性分离丁二酸模拟发酵液

    Institute of Scientific and Technical Information of China (English)

    吴昊; 姜岷; 韦萍; 高超; 杨高; 雷丹

    2011-01-01

    生物法制备的丁二酸发酵液中含有残留的底物(葡萄糖)、甲酸、乙酸及二价无机离子(Mg2+、SO42-)等杂质,不利于分离纯化.采用截留相对分子质量为160的纳滤膜LNG-NF-016对丁二酸模拟发酵液进行分离,考察了pH、操作压力、MgSO4浓度、丁二酸浓度、葡萄糖浓度、料液体积流量、操作温度等因素对纳滤分离性能的影响.纳滤分离的选择性由丁二酸的解离状态决定:模拟发酵液调节至pH3.0,丁二酸未解离,可将其与葡萄糖、MgSO4分离,丁二酸的透过率达98%,葡萄糖、MgSO4的截留率均>85%.随后将透过液调节至pH 6.0,丁二酸形成二价阴离子,可将其与单价的甲酸盐、乙酸盐分离,丁二酸截留率达90%,丁二酸被浓缩至121 g/L,而膜截留液中的甲酸、乙酸浓度均<5 g/L.同一型号纳滤膜可实现模拟发酵液中丁二酸与副产一元有机酸、底物及多价无机离子的选择性分离.%Many impurities existed in succinic acid fermentation broth, such as by-product organic acids (formic acid, acetic acid), residual substrate (glucose) and divalent ion (Mg2+, SO42-) , which was unfavorable to purification. Separation of succinic acid from simulated fermentation broth by nanofiltration membrane LNG-NF-016(MWCO 160) was studied, For this purpose, the effect of operating parameters such as pH in the feed solution, operation pressure, MgSO4 concentration, succinic acid concentration, glucose concentration, cross-flow rate and operation temperature on nanofiltration was investigated using an experimental design technique. The selectivity of nanofiltration depended on the degree of dissociation of succinic acid. At pH about 3. 0, undissociated succinic acid could be separated from glucose, and MgSCX with succinic acid permeation of 98% and glucose and MgSCX with rejection more than 85%. The divalent succinate could be separated from acetate and formate at pH about 6. 0, succinic acid rejection of

  11. 棘豆蠕孢菌发酵液中次级活性产物分离纯化初探%Preliminary Study on the Isolation and Purification of Active Secondary Metabolites in the Fermentation Broth of Embellisia oxytropis

    Institute of Scientific and Technical Information of China (English)

    时东方; 李丽; 郑梅竹; 李广洲; 张红晶; 王琦

    2009-01-01

    [Objective] The study aimed to lay a theoretical foundation for seeking for endophytic fungi with capability of synthesizing the same or similar active components which was synthesized in their host plants. [Method] The mycelia and fermentation broth were isolated by pumping filtration with Buchner funnel, the impure proteins, pigments, multivalent metal ions and polysaccharides were scavenged from fermentation broth through pretreatments. Then the fermentation products were isolated with macroporous resin and purified by silica gel chromatography. Finally, the sample and the component from host plants were ascertained to belong to the same class of alkaloid by infrared spectrum detection. [Result] The improved bismuth potassium iodide made sample show as a tangerine spot and the Ehrlich's chromogenic reagent made it show as a purplish red spot. Both of their Rf values were 0.78. The reactions of the water elution products and the 3 kinds of precipitants were negative. The reaction of alcohol-water elution products and bismuth potassium iodide was negative and that of alcohol-water elution products and picric acid and tannic acid were positive. The reactions of alcohol elution products and the 3 kinds of precipitants were positive. It was shown in the identification results that the isolated sample was hydroxyl substituted indolizidine alkaloids. [Conclusion] The endophytic fungus Embellisia oxytropis had the capability of synthesizing the same or similar active components which was synthesized in its host plant Gansu whin.%[目的] 为寻找具有合成与宿主植物相同或相似活性成分能力的内生真菌奠定理论基础.[方法] 利用布氏漏斗抽滤将菌丝体和发酵液分开,通过预处理除去发酵液中的杂蛋白、色素、高价金属离子和多糖,然后用大孔树脂分离发酵产物并利用硅胶柱层析进行纯化,最后通过红外光谱检测确定样品与宿主植物成分为同一类生物碱.[结果] 样品在改良

  12. 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).

  13. 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.

  14. A Novel Technique of Synthesis of Highly Fluorescent Carbon Nanoparticles from Broth Constituent and In-vivo Bioimaging of C. elegans.

    Science.gov (United States)

    Pramanik, A; Kole, A K; Krishnaraj, R N; Biswas, S; Tiwary, C S; Varalakshmi, P; Rai, S K; Kumar, B A; Kumbhakar, P

    2016-09-01

    Here we have demonstrated a novel single step technique of synthesis of highly fluorescent carbon nanoparticles (CNPs) from broth constituent and in vivo bioimaging of Caenorhabditis elegans (C. elegans) with the synthesized CNPs has been presented. The synthesized CNPs has been characterized by the UV-visible (UV-Vis) absorption spectroscopy, transmission electron microscopy (TEM) and Raman studies. The sp (2) cluster size of the synthesized samples has been determined from the measured Raman spectra by fitting it with the theoretical skew Lorentzian (Breit-Wigner- Fano (BWF)) line shape. The synthesised materials are showing excitation wavelength dependent tunable photoluminescence (PL) emission characteristics with a high quantum yield (QY) of 3 % at a very low concentration of CNPs. A remarkable increase in the intensity of PL emission from 16 % to 39 % in C. elegans has also been observed when the feeding concentration of CNPs to C. elegans is increased from 0.025 % to 0.1 % (w/v). The non-toxicity and water solubility of the synthesized material makes it ideal candidate for bioimaging. PMID:27380200

  15. Fermentative utilization of coffee mucilage using Bacillus coagulans and investigation of down-stream processing of fermentation broth for optically pure l(+)-lactic acid production.

    Science.gov (United States)

    Neu, Anna-Katrin; Pleissner, Daniel; Mehlmann, Kerstin; Schneider, Roland; Puerta-Quintero, Gloria Inés; Venus, Joachim

    2016-07-01

    In this study, mucilage, a residue from coffee production, was investigated as substrate in fermentative l(+)-lactic acid production. Mucilage was provided as liquid suspension consisting glucose, galactose, fructose, xylose and sucrose as free sugars (up to 60gL(-1)), and used directly as medium in Bacillus coagulans batch fermentations carried out at 2 and 50L scales. Using mucilage and 5gL(-1) yeast extract as additional nitrogen source, more than 40gL(-1) lactic acid was obtained. Productivity and yield were 4-5gL(-1)h(-1) and 0.70-0.77g lactic acid per g of free sugars, respectively, irrespective the scale. Similar yield was found when no yeast extract was supplied, the productivity, however, was 1.5gL(-1)h(-1). Down-stream processing of culture broth, including filtration, electrodialysis, ion exchange chromatography and distillation, resulted in a pure lactic acid formulation containing 930gL(-1)l(+)-lactic acid. Optical purity was 99.8%. PMID:27035470

  16. 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.

  17. Kinetics of biogas production from fermentation broth of wild cocoyam codigested with cow paunch in batch mode

    Directory of Open Access Journals (Sweden)

    I.C.E. Umeghalu

    2015-03-01

    Full Text Available Mathematical models are useful in solving the stability problems often exhibited by anaerobic digestion process. Kinetics of batch anaerobic digestion of cocoyam waste mixed with cow paunch for biogas production in batch mode was studied for 30 days hydraulic retention time (HRT. Data from cumulative biogas yield obtained during the experimental stages was fitted to C-NIKBRAN mathematical model based on first order reaction which adequately predicted the kinetic behavior of the substrate’s anaerobic biodegradability. The validity of the applied model was also verified through application of the regression model (ReG (Least Square Method using Excel Version 2003 in predicting the trend of the experimental results. Comparative analysis of Figs. 7-10 show very close alignment of curves which precisely translated into significantly similar trend of data point’s distribution for experimental (ExD, derived model (MoD and regression model-predicted (ReG results of cumulative biogas yield. Also, critical analysis of data obtained from experiment and derived model show low deviations on the part of the model-predicted values relative to values obtained from the experiment. This necessitated the introduction of correction factor, to bring the model-predicted cumulative biogas yield to those of the corresponding experimental values. Deviational analysis from strongly indicates that cumulative biogas yield was most reliable based on the associated admissible deviation of the model-predicted cumulative biogas yield from the corresponding experimental values; 9.2% within the pH range. The values of cumulative biogas yield within the highlighted deviation indicates over 90% confidence level for the applied model and over 0.9 effective dependency coefficients (EDC of cumulative biogas yield on pH, chemical oxygen demand (COD, total viable count (TVC and total dissolved solids (TDS. Also, deviation of model-predicted cumulative biogas yield from

  18. Method

    Directory of Open Access Journals (Sweden)

    Xixin Wang

    2012-01-01

    Full Text Available ZrO2 nanotube arrays were prepared by anodization method in aqueous electrolyte containing (NH42SO4 and NH4F. The morphology and structure of nanotube arrays were characterized through scanning electron microscope, X-ray diffraction, and infrared spectra analysis. The zirconia nanotube arrays were used as catalyst in esterification reaction. The effects of calcination temperature and electrolyte concentration on catalytic esterification activity have been investigated in detail. Experiments indicate that nanotube arrays have highest catalytic activity when the concentration of (NH42SO4 is 1 mol/L, the concentration of NH4F is 1 wt%, and the calcination temperature is 400°C. Esterification reaction yield of as much as 97% could be obtained under optimal conditions.

  19. 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. PMID:25465993

  20. 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.

  1. Relative gene expression in acid-adapted Escherichia coli O157:H7 during lactoperoxidase and lactic acid challenge in Tryptone Soy Broth.

    Science.gov (United States)

    Parry-Hanson, Angela A; Jooste, Piet J; Buys, Elna M

    2010-09-20

    Cross-protection of acid-adapted Escherichia coli O157:H7 against inimical stresses is mediated by the glucose-repressed sigma factor RpoS. However, many food systems in which E. coli O157:H7 occurs are complex and contain glucose. This study was aimed at investigating the contribution of acid and lactoperoxidase (LP)-inducible genes to cross-protection of E. coli O157:H7 against LP system and lactic acid (LA) in Tryptone Soy Broth (TSB). Acid-adapted and non-adapted E. coli O157:H7 were challenged to activated LP and LA at pH 4.0 and 5.0 in TSB for 6h at 25°C followed by expression of acid and LP-inducible genes. Acid-adapted E. coli showed cross-protection against activated LP and LA. All the acid-inducible genes tested were repressed at pH 4.0 with or without activated LP system. At pH 7.4, gadA, ompC and ompF were induced in acid-adapted cells. Induction of corA occurred in non-adapted cells but was repressed in acid-adapted cells. Although acid-inducible genes were repressed at pH 4.0, high resistance of acid-adapted cells indicates that expression of acid-inducible genes occurred during acid adaptation and not the actual challenge. Repression of rpoS indicates that RpoS-independent systems contribute to cross-protection in acid-adapted E. coli O157:H7.

  2. HPLC法检测丁二酸发酵液中的有机酸和水溶性维生素%Analysis of organic acids and hydrosoluble vitamins in succinic acid fernmentation broth by high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    赵文君; 屠春燕; 马海宁; 姜珉; 韦萍

    2011-01-01

    An innovative system of RP-HPLC method was proposed and optimized for detecting the organic acids and hydrosoluble vitamins in succinic acid fermentation broth. Under the optimal conditions, a Hedera ODS-2column (5μm, 4.6 mm × 250 mm) was used, the detection wavelength was 210 nm. Flow rate was 1.0 mL/min; Mobile phase A:20 mmol/L sodium dihydrogen phosphate(pH2.9), Mobile phase B: ACN; the gradient protocol was applied. All compounds were completely eluted in 15 min. All the correlation coefficients (r) of regression equations were above 0.9989, and the recoveries ranged from 92.5% to 100.3%. The relative standard deviations were in the range from 0.9% to 1.9%. By this method, organic acids and vitamins can be easily, rapidly and effectively determined.%采用高效液相色谱法(HPLC)同时检测丁二酸发酵液中的有机酸和水溶性维生素.以RP-HPLC为分离模式,选用Hedera ODS-2色谱柱(5μm,4.6×250mm),20mmol/L的磷酸盐缓冲溶液(pH 2.9)和乙腈为流动相,梯度洗脱,检测波长为210nm,建立了同时测定分析8种水溶性维生素和3种有机酸的方法,15min内所有组分都洗脱完全.8种水溶性维生素和3种有机酸在线性范围内峰面积与浓度呈良好的线性关系,相关系数为0.9989~0.9997;加标回收率在92.5%~100.3%之间;RSD(n=5):0.9%~1.9%.本方法采用同一种流动相既可以测定发酵液中的有机酸又可以测定水溶性维生素的含量.

  3. 超声波微波萃取-高效液相色谱法检测肉汤中的罂粟碱%Determination on papaverine in meat broth by Ultrasonic-microwave synergistic extraction-HPLC

    Institute of Scientific and Technical Information of China (English)

    信海红; 王庭欣; 朱路甲; 张晓宇; 王羽

    2012-01-01

    罂粟壳通常作为一种违法添加剂应用于火锅底料,目的是使人吃了上瘾,罂粟壳中含有多种生物碱,溶于肉汤食用后有害于健康.用75%的乙醇作为罂粟碱的提取液,利用超声波微波萃取仪对样品进行提取,高效液相色谱法(HPLC)进行含量分析,建立测定肉汤中罂粟碱的超声波微波萃取-高效液相色谱方法.其结果此方法罂粟碱在0.2~10mg/L范围内呈良好的线性关系,相关系数为0.9999.其平均回收率为94.47%;精密度相对标准偏差(RSD)为0.029%;重现性相对标准偏差(RSD)为0.665%.本方法具有回收率高、灵敏度高、精密度高等优点,可适用于食品中罂粟壳生物碱的检测,为确保农产品餐桌质量安全监控提供技术保障.%Pericarpium Papaverisis an illegal additives and usually used as food additives in the hot pot to let people addicted to the dish. Pericarpium Papaveris reacts with many typesof alkaloids in the dish and is harmful to healthA method for the determination of papaverine in meat broth using Ultrasonic - microwave synergistic extraction - HPLC was developed. The Ultrasonic- microwave synergistic extraction was used to extract the sample. In the concentration of 0. 2mg/L to 10mg/L, the result was linear (r = 0. 9999) . The average recovery was 94. 47% and the RSD of the precision was 0. 029% and the RSD of the reproducibility was 0. 665% . The method had high recovery, sensitivity and is very precise. It is suitable for the determination of papaverine in food. It provides the technical support to monitor the safety of agricultural products.

  4. High-throughput assay of adenosine in fermentation broth based on enzyme catalysis%酶法高通量测定发酵液中的腺苷含量

    Institute of Scientific and Technical Information of China (English)

    李宁; 董会娜; 祖昕; 张大伟; 吴勇杰

    2015-01-01

    腺苷是合成阿糖腺苷、腺苷酸(AMP)、三磷酸腺苷(ATP)的主要原料,是一种重要的医药原料.目前,微生物发酵生产腺苷越来越受到重视,会产生大量的发酵液样品需要检测.基于腺苷脱氨酶(ADA)建立了一种快速、高通量检测发酵液腺苷的方法.实验结果表明,响应面方法优化检测试剂浓度为碳酸钠-碳酸氢钠34.20mmol/L-27.40 mmol/L,亚硝基铁氰化钠3.35 g/L,次氯酸钠的有效氯为0.172 5%,百里香酚6.64 g/L.该方法检测灵敏,检测限为0.025~6 mmol/L,能够满足发酵检测和高通量筛选的需要.%Adenosine is the main raw material for the production of vidarabine,adenosine monophosphate (AMP) and adenosinetriphosphate (ATP).Adenosine is also an important pharmaceutical raw materials.At present,microbial fermentation production of adenosoine will produce large amounts of fermentation samples to be detected A rapid high -throughput method for detecting adenosine in fermentation broth based on adenosine deaminase (ADA)was estabished.Using response surface model analysis to determine the optimum concentration of four substances,the results showed sodium carbonate-sodium bicarbonate 34.20 mmol/L-27.40 mmol/L,sodium nitropmssid 3.35 g/L,the effective chlorine of sodium hypochlorite 0.172 5%,thymol 6.64 g/L.The limit of detection was between 0.025 mmo1/L and 6 mmo1/L,this method is sensitive and can meet the needs of the fermentation detection and high-throughput screening.

  5. Novel spectrophotometric method for detection and estimation of butanol in acetone-butanol-ethanol fermenter.

    Science.gov (United States)

    Maiti, Sampa; Sarma, Saurabh Jyoti; Brar, Satinder Kaur; Bihan, Yann Le; Drogui, Patrick; Buelna, Gerardo; Verma, Mausam; Soccol, Carlos Ricardo

    2015-08-15

    A new, simple, rapid and selective spectrophotometric method has been developed for detection and estimation of butanol in fermentation broth. The red colored compound, produced during reduction of diquat-dibromide-monohydrate with 2-mercaptoethanol in aqueous solution at high pH (>13), becomes purple on phase transfer to butanol and gives distinct absorption at λ520nm. Estimation of butanol in the fermentation broth has been performed by salting out extraction (SOE) using saturated K3PO4 solution at high pH (>13) followed by absorbance measurement using diquat reagent. Compatibility and optimization of diquat reagent concentration for detection and estimation of butanol concentration in the fermentation broth range was verified by central composite design. A standard curve was constructed to estimate butanol in acetone-ethanol-butanol (ABE) mixture under optimized conditions. The spectrophotometric results for butanol estimation, was found to have 87.5% concordance with the data from gas chromatographic analysis. PMID:25966390

  6. Simple method for quantifying viable bacterial numbers in sputum.

    OpenAIRE

    Pye, A.; Stockley, R A; Hill, S. L.

    1995-01-01

    AIMS--To establish a simple method of quantitative culture for determining the viable bacterial numbers present in expectorated sputum samples. METHODS--Sputum samples were homogenised with dithiothreitol, sterile saline or glass beads to determine which method recovered the greatest number of viable bacteria. Culture broths were also incubated with dithiothreitol and sampled over time to determine its effect on bacterial viability. Sputum samples homogenised with dithiothreitol were diluted ...

  7. The probability of growth of Listeria monocytogenes in cooked salmon and tryptic soy broth as affected by salt, smoke compound, and storage temperature.

    Science.gov (United States)

    Hwang, Cheng-An

    2009-05-01

    The objectives of this study were to examine and model the probability of growth of Listeria monocytogenes in cooked salmon containing salt and smoke (phenol) compound and stored at various temperatures. A growth probability model was developed, and the model was compared to a model developed from tryptic soy broth (TSB) to assess the possibility of using TSB as a substitute for salmon. A 6-strain mixture of L. monocytogenes was inoculated into minced cooked salmon and TSB containing 0-10% NaCl and 0-34 ppm phenol to levels of 10(2-3) cfu/g, and the samples were vacuum-packed and stored at 0--25 degrees C for up to 42 days. A total 32 treatments, each with 16 samples, selected by central composite designs were tested. A logistic regression was used to model the probability of growth of L. monocytogenes as a function of concentrations of salt and phenol, and storage temperature. Resulted models showed that the probabilities of growth of L. monocytogenes in both salmon and TSB decreased when the salt and/or phenol concentrations increased, and at lower storage temperatures. In general, the growth probabilities of L. monocytogenes were affected more profoundly by salt and storage temperature than by phenol. The growth probabilities of L. monocytogenes estimated by the TSB model were higher than those by the salmon model at the same salt/phenol concentrations and storage temperatures. The growth probabilities predicted by the salmon and TSB models were comparable at higher storage temperatures, indicating the potential use of TSB as a model system to substitute salmon in studying the growth behavior of L. monocytogenes may only be suitable when the temperatures of interest are in higher storage temperatures (e.g., >12 degrees C). The model for salmon demonstrated the effects of salt, phenol, and storage temperature and their interactions on the growth probabilities of L. monocytogenes, and may be used to determine the growth probability of L. monocytogenes in smoked

  8. Oligosaccharide Extraction and Purification from Fermentative Broth of Soybean Molasses%从大豆糖蜜发酵液中提取、纯化低聚糖

    Institute of Scientific and Technical Information of China (English)

    王昌涛; 黄鹏; 崔希庆

    2011-01-01

    In order to obtain highly pure soybean oligosaccharides, the removing technology of protein, pigment and salts from fermentative broth of soybean molasses has been studied. The results showed that: with 4% HCL adjusting pH 3, 6 000 r/min centrifugal speed and 10 min stirring, protein removal rate was 55.50%. The optimal decolorizing conditions of AB-8 macroporous resin were: pH 3, liquid velocity 1.5 BV/h and processing capacity 4.5 BV. Ion exchange resins 001x7 and D301 used together was the best in desalination. Purified soybean oligosaccharides was white translucent powder, taste sweet. The total sugar content and functional components content equal to 94.00% and 86.52% of the amount of solid content, respectively.%为获得纯度较高的大豆低聚糖,研究大豆糖蜜发酵液去蛋白、脱色和脱盐等工艺.用4% HCL调节发酵液pH值为3,搅拌时间10 min,离心转速6000 r/min,蛋白去除率55.50%.采用AB-8大孔树脂,在pH 3,液体流速1.5 BV/h,处理量4.5倍树脂床体积(BV)时,发酵液脱色效果最好,脱色率90%以上.当001×7和D301型离子交换树脂联用时脱盐效果较好.纯化获得的大豆低聚糖为白色透亮粉末,味微甜,总糖占固含物的94.00%,功能性成分占固形物的86.52%.

  9. Distribution of Listeria spp. in confectioners' pastries from western France: comparison of enrichment methods.

    Science.gov (United States)

    Ferron, P; Michard, J

    1993-06-01

    Three hundred samples of pastry from 100 different suppliers in western France, including butter-cream, whipped dairy cream and custard filled cakes from each supplier, were collected and tested for the occurrence of Listeria spp. in 25 g samples. Listeria spp. were detected in 21.7% of he samples: Listeria monocytogenes in 13.7%, Listeria innocua in 10% and Listeria seeligeri in 2.3%. Thirteen samples were contaminated with two species simultaneously. The frequency of contaminated samples was not related to the composition of the pastry filling used, but it seemed to increase with the number of aerobic contaminant microorganisms in the dairy cream-based samples. The contamination rate was dependent on the place of manufacture. The numbers of Listeria spp. and Listeria monocytogenes were estimated on positive samples at the 25 g level as follows: < 0.3/g, Listeria spp. in 47 samples, L monocytogenes in 27; 0.3-30/g, Listeria spp. in 13, L. monocytogenes in nine; 30-300/g, L. monocytogenes in one; 300-3000/g; L. monocytogenes in three; 700,000/g, L. monocytogenes in one. Various detection methods were tested, including two enrichments broths tested in parallel: a modified LEB broth using 10 mg/l acriflavine-HCl and the UVM 1 broth, with incubation at 30 degrees C and streaking onto PALCAM agar. The enrichment procedures were: (a) primary enrichment of 25 g sample and plating after 48 h and 7 days; (b) secondary enrichment by subculturing the primary enrichment broths incubated for 24 h and 6 days, into fresh enrichment broth, then plating after 24 h incubation; (c) pre-enrichment of 25 g sample for 24 h in the basal enrichment broths without inhibitors, followed by subculturing in complete broths which were plated after 24 h and 6 days incubation. In all cases, UVM performed better than the LEB broth. It was unnecessary to extend the primary enrichment period beyond 48 h. Secondary enrichments inoculated from 24-h incubated primary enrichments gave a slightly better

  10. Preliminary research on effect of fermentation broth of Bacillus amyloliquifaciens on fresh-keeping of chilled meat%解淀粉芽孢杆菌发酵液保鲜冷却猪肉的效果研究

    Institute of Scientific and Technical Information of China (English)

    时威; 谢为天; 张岩; 徐春厚; 刘颖

    2011-01-01

    实验研究了解淀粉芽孢杆菌发酵液对冷却肉的防腐保鲜效果,对冷却肉的微生物、感官品质和理化指标3个方面进行了检测.结果显示,解淀粉芽孢杆菌发酵液处理组可将冷却肉的保质期延长6d~9d,而且效果优于Nisin.解淀粉芽孢杆菌发酵液对冷却肉中主要污染菌-假单胞菌和潜在致病菌-单增李斯特菌有较好的抑制效果.解淀粉芽孢杆菌发酵液作为冷却肉的生物防腐剂,具有广阔的应用前景.%The preservation effect of the fermentation broth of Bacillus amyloliquifaciens on chilled meat was studied. Microbilogical, sensory and physical-chemical properties of chilled meat were determined. The results shown that the fermentation broth of Bacillus amyloliquifaciens applied to chilled meat could extend the shelf-life of chilled meat 6d~9d, and had much better effect than nisin. The fermented broth of Bacillus amyloliquifaciens could effectively inhibit the growth of Pseudomonas and Listeria monocytogenes. It had broad prospects as biological preservative for chilled meat

  11. The concentration-dependent nature of in vitro amphotericin B-itraconazole interaction against Aspergillus fumigatus: isobolographic and response surface analysis of complex pharmacodynamic interactions.

    NARCIS (Netherlands)

    Meletiadis, J.; Dorsthorst, D.T.A. te; Verweij, P.E.

    2006-01-01

    The interaction between polyenes and azoles is not well understood. We therefore explored the in vitro combination of amphotericin B with itraconazole against 14 clinical Aspergillus fumigatus isolates (9 itraconazole susceptible and 5 itraconazole resistant) with a colorimetric broth microdilution

  12. 电子鼻对酱牛肉煮制过程中老汤风味的检测%Detection of Flavor Compounds in the Broth during Cooking of Sauced Beef by Electronic Nose

    Institute of Scientific and Technical Information of China (English)

    白一凡; 贡慧; 张睿梅; 杨震; 乔晓玲

    2014-01-01

    利用电子鼻对酱牛肉煮制过程中的老汤进行风味分析,煮制时间4 h,每1 h取样1次,进行电子鼻风味检测。结果表明:随着煮制时间增加,老汤中的醇、醛、酮类及氮氧化物、硫化物成分升高,这些成分也是酱牛肉的主要风味物质来源。后将其数据分别进行主成分分析(principal component analysis,PCA)和线性判别式分析(linear discriminant analysis,LDA),发现LDA分析效果优于PCA。采用负荷加载分析判别不同传感器对于第一、第二主成分的贡献率及相关性,R2、R6、R7、R8、R9等可作为优选传感器应用于分析老汤风味变化。因此电子鼻系统用于监控酱牛肉加工过程中老汤的风味变化是可行的。%Electronic nose was used for the analysis of flavor constituents in sauced beef during 4 h of cooking by sampling the beef broth after every one hour. We found that the concentrations of alcohols, aldehydes, ketones, nitrogen oxides and sulfides in the broth, which contributed mainly to the flavor of sauced beef, increased with cooking time. For analysis of the experimental data, linear discriminant analysis (LDA) was better than principal component analysis (PCA). The contribution rates to the first and second principal components and correlations of different sensors were evaluated using loading analysis, and R2, R6 and R7 and R8, and R9 were selected as optimal sensors for the analysis of flavor changes of the broth. Hence, electronic nose is feasible for monitoring flavor changes of the broth during the manufacturing process of sauced beef.

  13. Survival of Escherichia coli O157:H7 in broth and processed salami as influenced by pH, water activity, and temperature and suitability of media for its recovery.

    OpenAIRE

    Clavero, M R; Beuchat, L R

    1996-01-01

    The survival of unheated and heat-stressed (52 degrees C, 30 min) cells of Escherichia coli O157:H7 inoculated into tryptic soy broth (TSB) adjusted to various pHs (6.0, 5.4, and 4.8) with lactic acid and various water activities (a(w)s) (0.99, 0.95, and 0.90) with NaCl and incubated at 5, 20, 30, and 37 degrees C was studied. The performance of tryptic soy agar (TSA), modified sorbitol MacConkey agar (MSMA), and modified eosin methylene blue agar in supporting colony development of incubated...

  14. Thrombolytic Function of Flammulina Velutipes Fermentation Broth on Arterial Thrombosis in Rats%金针菇发酵液对大鼠动脉血栓的溶栓作用

    Institute of Scientific and Technical Information of China (English)

    李思莹; 张瑜; 丛贺; 沈明花

    2015-01-01

    To study the effect of Flammulina Velutipes fermentation broth on arterial thrombosis in rats and its mechanisms. Animal model was induced by ferric chloride in rats, then the thrombus weight was detected, the morphological changes of vascular tissue were observed, and the levels of 6-keto-PGE1α, TXB2, ET-1, t-PA, PAI-1 and NO in plasma were measured. As compared with the model group, the thrombus weight reduced, the intravascular thrombosis dissolved to some extent, and vascular intimal damage reduced in Flammulina Velutipes fermentation broth group. Flammulina Velutipes fermentation broth increased the levels of NO , 6-keto-PGE1αand t-PA, reduced PAI-1 and TXB2 content. However, there was no significant difference in the ET-1 level. Flammulina Velutipes fermentation broth has the thrombolytic function. The effects may be due to its protective effect on vascular endothelial.%研究金针菇发酵液对大鼠动脉血栓的影响及可能机制。三氯化铁诱导大鼠颈动脉血栓模型,观察金针菇发酵液对血栓重量和血管组织形态学改变。检测血浆6-酮-前列腺素E1α(6-keto-PGE1α)、血栓素B2(TXB2)、血管内皮素-1(ET-1)、组织纤溶酶原激活物(t-PA)和纤溶酶原激活物抑制剂(PAI-1)的含量和一氧化氮(NO)水平。与模型组相比,用药组的血栓重量显著降低,血管内的血栓被溶解,血管内膜的损伤较轻。金针菇发酵液不同程度地提高NO、6-keto-PGE1α和t-PA水平,同时减少PAI-1和TXB2的含量,对ET-1水平的的影响并不明显。金针菇发酵液具有溶栓活性,它对血管内皮细胞的保护作用有可能是其溶栓机制之一。

  15. Rapid Determination of Seven Organic Acids in Fermentation Broth of Probiotics by Ion-Exclusion Chromatography%离子排阻色谱法快速测定益生菌发酵液中7种有机酸含量

    Institute of Scientific and Technical Information of China (English)

    黄静; 吴晓玉; 翟志军; 王园秀

    2016-01-01

    An ion-exclusion chromatography method was established for the rapid separation and detection of the primary organic acids in fermentation broth of probiotics. Seven organic acids including formic,acetic, propionic,lactic,n-butyric,succinic and citric acids from fermentation products of probiotics were separated and measured under the condition of Aminex HPX-87H column, the mixture mobile phase composed by 3.5 mmol/L sulfuric acid and acetonitrile (volume ratio 99:1),the column temperature at 50 ℃,the rate of mobile phase was 0.6 mL/min and the detection wavelength was 210 nm.The results demonstrated that the sev-en organic acids possessed good linear relationships in the range 0.02-22.34 g/L,and the liner correlation co-efficients were 0.99982-0.99999.The recovery rates of standard addition were 97.28%-107.33% for these seven organic acids by fermentation broth of Lactobacillus casei,and the precisions were 0.47%-2.07% ( n=5) .The main organic acids in the 36 h fermentation liquids of eight strains of probiotics were analyzed and com-pared rapidly by the method.It was fairly simple,rapid,and accurate,and expected to be applied to the separa-tion and detection of the primary organic acids in fermentation broth of probiotics.%运用离子排阻色谱法建立益生菌发酵液中主要有机酸的快速分离与检测方法.采用Aminex HPX-87H分析柱,选用3.5 mmol/L硫酸与乙腈混合液(体积比为99:1)为流动相,在柱温50℃、流速0.6 mL/min及检测波长为210 nm条件下,对益生菌发酵产品中甲酸、乙酸、丙酸、乳酸、正丁酸、琥珀酸及柠檬酸7种有机酸进行分离与检测.结果表明:7种有机酸在0.02~22.34 g/L内线性关系较好,回归方程的线性相关系数为0.99982~0.99999.利用干酪乳杆菌(Lactobacillus casei)发酵液检测加标回收率为97.28%~107.33%,精密度为0.47%~2.07%(n=5).利用该方法实现了对8株益生菌36 h发酵液中主要有机酸含量的快速分析比较.此法简单、

  16. Narrow-Spectrum Cephalosporin Susceptibility Testing of Escherichia coli with the BD Phoenix Automated System: Questionable Utility of Cephalothin as a Predictor of Cephalexin Susceptibility▿

    OpenAIRE

    Zhang, Sean X.; Parisian, Fern; Yau, Yvonne; Fuller, Jeffrey D.; Poutanen, Susan M.; Richardson, Susan E.

    2007-01-01

    The resistance of Escherichia coli to cephalothin was found to be overestimated when the Phoenix automated susceptibility system was used to determine resistance compared to reference broth microdilution, a finding that jeopardized the use of cephalexin for first-line treatment of urinary tract infections in children. In addition, using broth microdilution, we studied the accuracy of either cephalothin or cefazolin in predicting cephalexin susceptibility. In contrast to the recommendation of ...

  17. Effect of Low-Temperature and High-Pressure Boiling and NaCl Addition on Protein Content and Flavor Components of Bovine Bone Broth%低温高压及预先添加NaCl对牛骨汤的煮制效果及风味成分的影响

    Institute of Scientific and Technical Information of China (English)

    刘文营; 李迎楠; 成晓瑜; 贾晓云; 曲超; 李家鹏; 陈文华

    2016-01-01

    研究加压煮制对牛骨汤煮制效果的影响,并对预先添加NaCl对骨汤风味的影响进行分析。结果表明:低温高压相较于常规煮制,蛋白质溶出速率有显著提升。气质联用对风味物质进行检测结果显示:肉汤中酯类、杂环物质、酮类、烃类、酸类、醛类、芳香族化合物和醇类等均有不同程度的变化;加入NaCl煮制时肉汤中酯类、酸类、芳香族和醇类物质种类和相对含量均有不同程度的增加,杂环物质种类和相对含量较仅加压制备样品有显著下降;酮类、醛类和醇类物质种类均有不同程度的增加,但是相对含量均较对照组要小;烃类物质种类没有发生变化,但是相对含量明显增加。因此,加压煮制过程中添加NaCl,对牛骨汤中挥发性物质的种类有明显影响。%The effect of boiling under pressurized condition on the protein content of bovine bone broth was investigated as well as the effect of NaCl addition during boiling on its lfavor components. The dissolution rate of protein was signiifcantly accelerated under low-temperature and high-pressure conditions compared with the conventional boiling method. The esters, heterocyclic compounds, hydrocarbons, ketones, acids, aldehydes, aromatic compounds and alcohols in the broth changed to different extents as detected by GC-MS. The composition and relative contents of esters, acids, aromatic compounds and alcohols were increased upon NaCl addition during boiling, while those of heterocyclic compounds in the sample boiled under pressurized condition without NaCl addition were signiifcantly reduced. In addition, the numbers of ketones, aldehydes and alcohols were increased, but their relative contents were lower than in the control group. The composition of hydrocarbons did not change although their relative contents were signiifcantly enhanced. Thus, NaCl addition during boiling had a signiifcant effect on the composition of

  18. Standardization of a quantification method for Salmonella spp. and Shigella spp. in specific liquid media

    Directory of Open Access Journals (Sweden)

    Sandra Patricia Rivera

    2010-03-01

    Full Text Available Introduction: Chlorination is the most widely used disinfection process for drinking water production. The formation of chlorination carcinogenic by-products and chlorine intoxication by direct manipulation in small communities has motivated the study of alternative disinfection processes. In this sense, processes of advanced oxidation (PAOs have yielded promising results. Escherichia coli (E. coli is customarily used as faecal bacterial indicator to determine the efficiency of disinfection processes. However, it has been shown that E. coli is less resistant to disinfection than other enteric bacteria such as Shigella spp. and Salmonella spp. Additionally, the viable non-culturable (VNC state yields bacteria which are not detectable on many culture media.Objective: The main objective is to standardize a method for counting Salmonella spp. and Shigella spp. in specific liquid media to reliably quantify the bacteriological potential risk related to disinfection processes based on PAO.Methods: The study followed a randomized bi-factorial experimental design and the Duncan multiple comparison test. This design allowed the selection of specific liquid media to fittingly standardize the counting of Salmonella spp. and Shigella spp.Results: We found that the best broth for counting Salmonella typhimurium strain at different concentrations in pure and mixed cultures was the Rappaport broth RP, the EE broth also allowed growing the two bacterial species tested in this research. Nonetheless, the latter results suggest the use of additional tests for this particular broth.Discussion: There was a variation in the counting results when pure cultures were used compared to those obtained from mixtures of microorganisms. It was also noted that Salmonella typhimurium and Shigella sonnei, were recovered from minimal concentrations in both RP and EE broths, respectively. To some extent, this suggests an additional confirmative method when using the EE® broth

  19. Standardization of a quantification method for Salmonella spp. and Shigella spp. in specific liquid media

    Directory of Open Access Journals (Sweden)

    Sandra Patricia Rivera

    2010-09-01

    Full Text Available Introduction: Chlorination is the most widely used disinfection process for drinking water production. The formation of chlorination carcinogenic by-products and chlorine intoxication by direct manipulation in small communities has motivated the study of alternative disinfection processes. In this sense, processes of advanced oxidation (PAOs have yielded promising results. Escherichia coli (E. coli is customarily used as faecal bacterial indicator to determine the efficiency of disinfection processes. However, it has been shown that E. coli is less resistant to disinfection than other enteric bacteria such as Shigella  spp. and Salmonella  spp. Additionally, the viable non-culturable (VNC state yields bacteria which are not detectable on many culture media. Objective: The main objective is to standardize a method for counting Salmonella  spp. and Shigella  spp. in specific liquid media to reliably quantify the bacteriological potential risk related to disinfection processes based on PAO. Methods: The study followed a randomized bi-factorial experimental design and the Duncan multiple comparison test. This design allowed the selection of specific liquid media to fittingly standardize the counting of Salmonella  spp. and Shigella  spp. Results: We found that the best broth for counting Salmonella typhimurium strain at different concentrations in pure and mixed cultures was the Rappaport broth RP, the EE broth also allowed growing the two bacterial species tested in this research. Nonetheless, the latter results suggest the use of additional tests for this particular broth. Discussion: There was a variation in the counting results when pure cultures were used compared to those obtained from mixtures of microorganisms. It was also noted that Salmonella typhimurium and Shigella sonnei, were recovered from minimal concentrations in both RP and EE broths, respectively. To some extent, this suggests an additional confirmative method when using the

  20. Comparison of subtypes of Listeria monocytogenes isolates from naturally contaminated watershed samples using a combination of non-selective and selective enrichment methods

    Science.gov (United States)

    Two enrichment methods for Listeria monocytogenes using Immuno Magnetic Separation were tested to determine if they selected the same subtypes of isolates. Both methods included a non-selective enrichment and one included subculture in Fraser Broth. Naturally contaminated watershed samples from the ...

  1. Novel Method of Lactic Acid Production by Electrodialysis Fermentation

    OpenAIRE

    Hongo, Motoyoshi; Nomura, Yoshiyuki; Iwahara, Masayoshi

    1986-01-01

    In lactic acid fermentation by Lactobacillus delbrueckii, the produced lactic acid affected the lactic acid productivity. Therefore, for the purpose of alleviating this inhibitory effect, an electrodialysis fermentation method which can continuously remove produced lactic acid from the fermentation broth was applied to this fermentation process. As a result, the continuation of fermentation activity was obtained, and the productivity was three times higher than in non-pH-controlled fermentati...

  2. 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.

  3. Screening for methicillin-resistant Staphylococcus aureus in clinical swabs using a high-throughput real-time PCR-based method

    DEFF Research Database (Denmark)

    Ornskov, D; Kolmos, B; Bendix Horn, P;

    2008-01-01

    samples were incubated overnight in a selective tryptone soya broth and were analysed by PCR the following day. Using this strategy, non-colonised individuals were identified within 24 h, while MRSA-positive samples were analysed further by traditional microbiological methods to determine the resistance...

  4. Isolation of Mycobacterium kumamotonense from a patient with pulmonary infection and latent tuberculosis.

    Science.gov (United States)

    Kontos, Fanourios; Mavromanolakis, Dimitrios Nikitas; Zande, Marina Chari; Gitti, Zoe Georgios

    2016-01-01

    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. PMID:27080783

  5. 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.

  6. Antifungal activity of raw extract and flavanons isolated from Piper ecuadorense from Ecuador

    OpenAIRE

    Jorge Ramirez; Luis Cartuche; Vladimir Morocho; Silvio Aguilar; Omar Malagon

    2013-01-01

    The MeOH extract of Piper ecuadorense Sodiro, Piperaceae, was chosen for metabolite isolation and elucidation due to the strong antifungal activity exhibited, measured by means of the broth microdilution method. Two known flavonoids: pinostrobin (1) and pinocembrin (2) were isolated from 4.16 g. of dichloromethane extract by column chromatography, using a gradient of hexane/EtOAc. A total of 20 mg of 1 were obtained from the fraction eluted with hexane-EtOAc 95:5 v/v, and 100 mg of 2 were obt...

  7. 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

  8. 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

  9. 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

  10. 高效液相色谱法同时测定发酵液中木糖醇和L-木酮糖的含量%Simultaneous determination of xylitol and L-xylulose in fermentation broth with high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    葛驰宇; 蒋洁; 翁旭; 张君丽

    2016-01-01

    目的:建立高效液相色谱( HPLC)同时测定发酵液中底物木糖醇和产物L-木酮糖含量的方法。方法采用C18色谱柱(250 mm ×4.6 mm),柱温35℃,以乙腈-水(体积比为85∶15)为流动相,流速0.8 mL/min。用示差折光检测器检测木糖醇,检测器温度为33℃。用紫外检测器在室温下检测L-木酮糖,检测波长为210 nm。结果所得木糖醇的线性范围为0.50~30.00 g/L,相关系数为0.9995,最低检出限为0.18 g/L,最低定量限为0.58 g/L;所得L-木酮糖的线性范围为0.30~30.00 g/L,相关系数为0.9986,最低检出限0.15 g/L,最低定量限为0.40 g/L;木糖醇的日内和日间相对标准偏差( RSD)均分别小于0.64%和0.80%,L-木酮糖的日内和日间RSD均分别小于0.31%和0.59%;回收率均在99.00%~101.00%之间。结论建立的HPLC法不受发酵液中其他组分的干扰,可同时测定底物木糖醇和产物L-木酮糖的含量,并实时监控发酵的全过程。%Objective A high performance liquid chromatographic (HPLC) method was established for the simultaneous determination of xylitol and L-xylulose in fermentation broth.Methods The chromatographic conditions were as follows:C18 column (250 mm ×4.6 mm) with the temperature 35℃, acetonitrile-water (85∶15,v/v)as mobile phase with the flow rate of 0.8 mL/min.Xylitol was detected by refractive index (RI) detector at 33℃and L-xylulose was determined by ultraviolet ( UV) detector at 210 nm at room temperature.Results This method showed good linearity over the range from 0.50~30.00 g/L with a correlation coefficient of 0.9995 for xylitol and 0.30~30.00 g/L with a correlation coefficient of 0.9986 for L-xylulose. Moreover, the limit of quantification (LOQ) for xylitol and L-xylulose were 0.58 and 0.40,respectively.The limit of determination (LOD) for xylitol and L-xylulose were 0.18 and 0

  11. Decreasing the Level of Ethyl Acetate in Ethanolic Fermentation Broths of Escherichia coli KO11 by Expression of Pseudomonas putida estZ Esterase†

    OpenAIRE

    Hasona, Adnan; York, S W; Yomano, L. P.; Ingram, L O; Shanmugam, K T

    2002-01-01

    During the fermentation of sugars to ethanol relatively high levels of an undesirable coproduct, ethyl acetate, are also produced. With ethanologenic Escherichia coli strain KO11 as the biocatalyst, the level of ethyl acetate in beer containing 4.8% ethanol was 192 mg liter−1. Although the E. coli genome encodes several proteins with esterase activity, neither wild-type strains nor KO11 contained significant ethyl acetate esterase activity. A simple method was developed to rapidly screen bact...

  12. 26S rDNA序列分析法鉴定开菲尔发酵液中的酵母菌%Identification of Yeast Strains in Kefir Fermented Broth by 26S rDNA Sequence Analysis

    Institute of Scientific and Technical Information of China (English)

    范佳; 武伟伟; 李艳

    2014-01-01

    Sequence analysis of 26S rDNA D1/D2 region was applied to identify the yeast strains involved in traditional Kefir fermented broth in Inner Mongolia for the purpose of laying the foundation for selecting proper yeast strains for featured fermented milk drink. Firstly, yeast strains were isolated from Kefir fermented broth, then their colony morphology and cell microscopic morphology were observed, and finally, sequence analysis of 26S rDNA D1/D2 region was carried out. The results showed that, 36 yeast strains in total were isolated and they belonged to five mor-phological types, after DNA extraction, PCR amplification of 26S rDNA D1/D2 region, restriction digestion, sequence analysis and homology comparison, all the yeast stains were further identified at the species level including Rhodotorula mucilaginosa, Candida zeylanoides, Pichia fer-mentans, Saccharomyces cerevisiae and Torulaspora delbrueckii. The yeast strains isolated from traditional Kefir fermented broth had the poten-tials for the fermentation of featured fermented milk drink.%利用26S rDNA D1/D2区序列分析法鉴定了内蒙古牧区传统开菲尔发酵液中的酵母菌,为筛选可发酵特色乳酒的酵母菌奠定基础。对所分离纯化得的酵母菌进行菌落特征和细胞显微形态区分,在形态鉴定基础上,选择代表菌进行26S rDNA D1/D2区序列分子鉴定。结果表明,共分离到36株酵母菌,形态聚类为5类,经DNA提取、26S rDNA D1/D2区PCR扩增、酶切、基因序列分析和同源性比对,鉴定为5种分子类型的酵母菌,分别为胶红酵母菌(Rhodotorula mucilaginosa)、诞沫假丝酵母菌(Candida zeylanoides)、发酵毕赤酵母菌(Pichia fermentans)、酿酒酵母菌(Saccharomyces cerevisiae)、有孢圆酵母菌(Torulaspora delbrueckii)。传统开菲尔发酵液中分离到的酿酒酵母,具有可发酵特色乳酒的潜质。

  13. A Rapid Filtration Sampling Probe for Fermentation Broth On-line Measurement%在线测量发酵液葡萄糖浓度的过滤取样探头的研制

    Institute of Scientific and Technical Information of China (English)

    高学金; 薛吉星; 张鹏; 王普

    2014-01-01

    设计了一种罐内快速过滤取样探头,以解决在线测量发酵参数过程中的发酵液连续取样问题。此探头由支撑体、旋塞阀、O 型圈、过滤膜管、管盖组成,可以直接插入发酵罐内,能够承受发酵前期的灭菌高温,并能避免取样时杂菌入侵发酵液。过滤膜采用筒状陶瓷膜,罐内发酵液经错流过滤,可由蠕动泵抽取适量无菌的渗透液给分析仪。利用此装置对葡萄糖溶液进行了取样测试,结果表明,此装置适用于发酵液在线取样,取样速率为3.0 mL/ min,葡萄糖透过率保持100%,探头引起的时间延迟约为2 min。%An inner-bioreactor rapid filtration sampling probe was designed to resolve the problems of continuous sampling the fermentation broth in on-line measurement the fermentation process. The probe consists of a support, a plug valve, an O-ring, a filter membrane and a pipe cover. It can be inserted directly into the bio-reactor withstanding high-temperature sterilization before fermentation, or preventing the bacteria's invasion during sampling. Fermentation broth in tank is cross-flow filtrated by a cylindrical ceramic membrane which is used as filtration membrane, and then the sterile permeated liquid is transported to the analyzer by a peristaltic pump. The sampling experiments using this device was described for sampling glucose solution indicating it is suitable for fermentation online sampling. The sampling rate is up to 3. 0 mL/ min, glucose permeability maintains 100% , and the delay time caused by the probe is about 2 min.

  14. Antifungal activity of ibuprofen against aspergillus species and its interaction with common antifungal drugs

    Institute of Scientific and Technical Information of China (English)

    LI Li-juan; CHEN Wei; XU Hui; WAN Zhe; LI Ruo-yu; LIU Wei

    2010-01-01

    Background The incidence of invasive aspergillosis (IA) has increased in frequency in immunocompromised patients with a variety of diseases. The poor prognosis might be due to limited treatment option. This study aimed to evaluate antifungal activity of ibuprofen against clinical isolates of aspergillus species, as well as its interaction with azoles or with amphotericin B or with micafungin.Methods Antifungal activity of ibuprofen against 10 strains of Aspergillus fumigatus, Aspergillus flavus, and Aspergillus terreus were tested with both disk diffusion assay and standard broth microdilution method. To determine whether ibuprofen combined with itraconazole, voriconazole, amphotericin B, or micafungin had interactive effects on aspergillus spp., we used both disk diffusion assay and Chequerboard method.Results As for disk diffusion method, ibuprofen produced a zone of growth inhibition with diameters of (20.1±3.9) mm at 48 hours of incubation. As for broth microdilution method, the minimal inhibitory concentration (MIC) ranges of ibuprofen against aspergillus spp. were 1000-2000 μg/ml, and the minimal fungicidal concentration (MFC) ranges of that was 2000-8000 μg/ml. For 2 of 5 isolates, when ibuprofen combined with itraconazole or voriconazole, the zones of growth inhibition were larger than those of the individual drug. The results of Chequerboard method showed that fractional inhibitory concentration index (FICI) ranges were 1.125-2.500.Conclusions Ibuprofen is active against aspergillus spp.. And ibuprofen does not affect the in vitro activity of itraconazole, voriconazole, amphotericin B or micafungin against aspergillus spp..

  15. Antifungal Activity of Bee Venom and Sweet Bee Venom against Clinically Isolated Candida albicans

    Directory of Open Access Journals (Sweden)

    Seung-Bae Lee

    2016-03-01

    Full Text Available Objectives: The purpose of this study was to investigate the antifungal effect of bee venom (BV and sweet bee venom (SBV against Candida albicans (C. albicans clinical isolates. Methods: In this study, BV and SBV were examined for antifungal activities against the Korean Collection for Type Cultures (KCTC strain and 10 clinical isolates of C. albicans. The disk diffusion method was used to measure the antifungal activity and minimum inhibitory concentration (MIC assays were performed by using a broth microdilution method. Also, a killing curve assay was conducted to investigate the kinetics of the anti- fungal action. Results: BV and SBV showed antifungal activity against 10 clinical isolates of C. albicans that were cultured from blood and the vagina by using disk diffusion method. The MIC values obtained for clinical isolates by using the broth microdilution method varied from 62.5 μg/ mL to 125 μg/mL for BV and from 15.63 μg/mL to 62.5 μg/mL for SBV. In the killing-curve assay, SBV behaved as amphotericin B, which was used as positive control, did. The antifungal efficacy of SBV was much higher than that of BV. Conclusion: BV and SBV showed antifungal activity against C. albicans clinical strains that were isolated from blood and the vagina. Especially, SBV might be a candidate for a new antifungal agent against C. albicans clinical isolates.

  16. 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.

  17. 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. PMID:20397104

  18. 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.

  19. Comparison of methods for total genomic DNA extraction from Sichuan pickled vegetables broth%四川泡菜盐卤中微生物总基因组DNA提取方法的比较

    Institute of Scientific and Technical Information of China (English)

    蒋云露; 杨建涛; 王猛; 罗军; 蒋倩; 姜露熙; 张琴; 饶瑜; 马力

    2015-01-01

    了得到较高质量的基因组脱氧核糖核酸(DNA),本实验采取了5种方法对四川泡菜盐卤总基因组进行提取,对其提取的浓度、纯度进行分析比较,并以此为模版进行聚合酶链反应(PCR)体外扩增.结果表明,F1所得的基因组DNA纯度及浓度最高,F4方法提取的基因组DNA浓度较高,但受到蛋白或酚类物质的污染,F2以及F5两种方法得到的基因组DNA浓度较低,F3所得的基因组DNA浓度低并且含有较多RNA杂质.因此,本研究采用的5种对四川泡菜盐卤进行总基因组提取方法中,方法F1最合理、高效.

  20. An HPLC method for the quantitative determination of clavulanic acid in fermentation broth%高效液相色谱法测定棒状链霉菌发酵液中克拉维酸的含量

    Institute of Scientific and Technical Information of China (English)

    王明林; 林陟昕; 田威; 何建勇

    2003-01-01

    利用克拉维酸与咪唑试剂的衍生化反应,建立了用高效液相色谱仪测定发酵液中克拉维酸含量的方法.色谱条件为:采用Hypersil ODS2柱(5μm,4.6mm×200mm),流动相为0.1mo1/LKH2PO4:甲醇(94:6),流速1.0ml/min,检测波长311nm.结果表明,克拉维酸量在1~10.0μg范围内,该方法的线性关系及测定结果的精密度、回收率均良好,是一种简便、快速、有效的方法.

  1. Studies on bactericidal efficacy of pumpkin (Cucurbita moschata Duchesne) peel

    Institute of Scientific and Technical Information of China (English)

    El Zawane Kamarudin; Qamar Uddin Ahmed; Zuvairea Nazren Mohd Sirajudin; Ahmad Jalal Khan Chowdhury

    2014-01-01

    Objective: To explore the in vitro antibacterial potential of the peel of Cucurbita moschata Duchesne (tropical pumpkin) (C. moschata) against human pathogenic bacteria. Methods:In the present study, dichloromethane (DCM), methanol (MEOH) and aqueous extracts of C. moschata peel were examined for in vitro antibacterial potency against eight bacterial strains i.e. Bacillus cereus, Burkholderia cepacia, Escherichia coli, Enterococcus faecalis, Staphyloccocus aureus, Pseudomonas aerugenosa, Vibrio alginolyticus, Vibrio parahaemolyticus using Kirby-Bauer disk diffusion susceptibility and broth micro-dilution methods. Results: DCM extract of pumpkin peel exhibited the maximum zone of inhibition against Staphyloccocus aureus (21 mm) whereas aqueous extract of pumpkin peel revealed the least zone of inhibition against Escherichia coli (8 mm). MEOH extract gave maximum zone of inhibition against Pseudomonas aerugenosa (19 mm). Broth micro-dilution method showed minimum inhibitory concentration for the DCM extract against Burkholderia cepacia at 6.25 mg/mL. The minimum bactericidal concentrations were also determined to know the nature of all extracts. DCM and MEOH extracts exhibited bactericidal nature to all bacterial strains except for the Vibrio alginolyticus. The minimum bactericidal concentrations values exhibited bactericidal nature ranging from 3.12 mg/mL to 100.00 mg/mL. The screening of antimicrobial properties of different extracts of C. moschata peel revealed that the DCM extract possessed good antimicrobial efficacy compared to MEOH and aqueous extracts. Conclusions: Peel of C. moschata possesses antibacterial compounds and could be potential source for a new class of antibiotics.

  2. Native Brazilian plants against nosocomial infections: a critical review on their potential and the antimicrobial methodology.

    Science.gov (United States)

    H Moreno, Paulo Roberto; da Costa-Issa, Fabiana Inácio; Rajca-Ferreira, Agnieszka K; Pereira, Marcos A A; Kaneko, Telma M

    2013-01-01

    The growing incidences of drug-resistant pathogens have increased the attention on several medicinal plants and their metabolites for antimicrobial properties. These pathogens are the main cause of nosocomial infections which led to an increasing mortality among hospitalized patients. Taking into consideration those factors, this paper reviews the state-of-the-art of the research on antibacterial agents from native Brazilian plant species related to nosocomial infections as well as the current methods used in the investigations of the antimicrobial activity and points out the differences in techniques employed by the authors. The antimicrobial assays most frequently used were broth microdilution, agar diffusion, agar dilution and bioautography. The broth microdilution method should be the method of choice for testing new antimicrobial agents from plant extracts or isolated compounds due to its advantages. At the moment, only a small part of the rich Brazilian flora has been investigated for antimicrobial activity, mostly with unfractionated extracts presenting a weak or moderate antibacterial activity. The combination of crude extract with conventional antibiotics represents a largely unexploited new form of chemotherapy with novel and multiple mechanisms of action that can overcome microbial resistance that needs to be further investigated. The antibacterial activity of essential oil vapours might also be an interesting alternative treatment of hospital environment due to their ability in preventing biofilm formation. However, in both alternatives more studies should be done on their mode of action and toxicological effects in order to optimize their use. PMID:24200361

  3. Thermal tolerance characteristics of non-O157 Shiga toxigenic strains of Escherichia coli (STEC) in a beef broth model system are similar to those of O157:H7 STEC.

    Science.gov (United States)

    Vasan, Akhila; Leong, Wan Mei; Ingham, Steve C; Ingham, Barbara H

    2013-07-01

    The non-O157 Shiga toxigenic Escherichia coli (STEC) serogroups most commonly associated with illness are O26, O45, O103, O111, O121, and O145. In the United States, these serogroups are considered adulterants in raw nonintact beef. To begin to understand the behavior of these pathogens in meat systems, we compared the thermal tolerance of acid-adapted cells of non-O157 STEC and O157:H7 STEC in a beef-derived broth. D58°C-values were determined for at least three strains per serogroup, and D54.6°C-values and D63.6°C-values were determined for one strain per serogroup. Each strain was grown to stationary phase in brain heart infusion broth (BHIB; pH 7.0) and inoculated into prewarmed BHIB in a shaking water bath for thermotolerance experiments at 54.6, 58.0, or 63.6°C (three trials per strain). Samples were heated for up to 160 min at 54.6°C, 3 min at 58.0°C, or 45 s at 63.6°C, with periodic sampling followed by rapid cooling and plating on modified Levine's eosin methylene blue agar. For each strain and temperature, the log CFU per milliliter was plotted versus time, and D-values were determined. Across all strains, the least and most heat tolerant STEC serogroups at 58°C were O145 and O157, respectively. D58°C-values in BHIB ranged from 0.44 min for an O145 strain to 1.42 min for an O157:H7 strain. D58°C-values for O157 STEC strains were significantly higher than those for at least one strain in each of the non-O157 STEC serogroups (P < 0.05) except for serogroup O103. At 54.6°C, the most heat-resistant STEC strain belonged to serogroup O103 and was significantly more heat tolerant than the O157:H7 strains (P < 0.05). Grouping the strains, there were no significant differences in heat tolerance between O157 and non-O157 STEC at 63.6°C (P ≥ 0.05). The z-values for non-O157 STEC strains were comparable to those for O157:H7 STEC strains (P ≥ 0.05), ranging from 4.10 to 5.21°C. These results suggest that thermal processing interventions that target

  4. Too many cooks spoil the broth?

    DEFF Research Database (Denmark)

    Rørbæk, Anne

    To collaborate across organisational contexts is not an easy task, but to do so and to succeed can be vital for reaching creative and innovative results. This paper is an empirical exploration of contextual challenges for collaborative museum design, focusing on the interplay between museums...

  5. A study on the process and activation of recovering nisin from the fermentation broth by foam separation%泡沫分离发酵液中乳链菌肽的工艺和活性研究

    Institute of Scientific and Technical Information of China (English)

    刘云菲; 胡滨; 吴兆亮

    2012-01-01

    Nisin is a kind of antimicrobial peptides widely used but easy to lose activation, and it is difficult to separate and purify. In this paper, the foam separation technology is used for the recovering of nisin from the fermentation broth. The effect of the gas velocity, the temperature and the gas-distribution aperture to enrichment ratio, recovery rate and in-activation rate of nisin is discussed. The experimental results show that with the gas velocity increasing, the recovery rate increases, and the enrichment ratio and the nisin inactivation rate decrease; with the temperature increasing, the enrichment ratio and the nisin inactivation rate increase, and the recovery rate decreases; with the gas-distributor aperture augments, bubbles become larger, the enrichment ratio and the nisin inactivation rate increase, and the recovery rate decreases.%乳链菌肽(nisin)是一种用途广泛但容易失活的抗菌肽,分离纯化难度大.本文以发酵液为实验物系,利用泡沫分离技术从中分离纯化nisin,研究了气速、温度、分布器孔径对实验物系的影响.实验结果表明,随着气速的增加,泡沫分离乳链菌肽的富集比减小,回收率增大,nisin 的失活率逐渐减小 ;随着温度的升高,泡沫分离乳链菌肽的富集比增加,回收率降低,nisin的失活率增大 ;随分布器孔径增大,气泡变大,泡沫分离乳链菌肽的富集比增大,回收率降低,nisin的失活率增大.

  6. 基于 AOPAN 纳米纤维膜的粘杆菌素发酵液后处理研究%Study on preparation of AOPAN nanofibrous membrane and their applications for filtration treatment of colistin fermentation broth

    Institute of Scientific and Technical Information of China (English)

    凤权; 魏安静; 侯大寅; 武丁胜

    2014-01-01

    Polyacryonitrile ( PAN) nanofibers were prepared by electrospinning, and amidoximepolyacryonitrile ( AOPAN) nanofibrous membranes were generated by chemical modification of PAN nanofibers, which were used as the filtration membrane for separation of colistin fermentation broth.According to the experimental data, characters materials and comparing nanofibrous membranes filtration separation performance, double-layer nanofibrousmembrane was selected.The optimum operating parameters had been determined:pressure was 0.14 Mpa.Under these optimum parameters, the flux of the nanofibrous membrane was 2.61 L/m2 .min, the protein reta-tion ratio was is nearly 90%, and the part of pigment and other impurities had been removed.%使用静电纺丝再经胺肟化改性制备AOPAN纳米纤维膜,并基于AOPAN纳米纤维膜构建膜分离装置,用于粘杆菌素发酵液的后处理。研究中,对不同厚度的纳米纤维膜的渗透通量及分离性能进行比较,最终确定双层叠合的纳米纤维膜为分离膜,最适操作压力为0.14 MPa。在此条件下,分离膜的渗透通量为2.61 L/m2.min,蛋白质的截留率达到90%,色素等其他杂质也得到有效去除。

  7. Isolation, Identification and Biogenic Amines-producing Ability of Lactic Acid Bacteria from The Fermentation Broth of Chinese Rice Wine%黄酒发酵液中产生物胺乳酸菌的分离鉴定与评价

    Institute of Scientific and Technical Information of China (English)

    周韩玲; 杜丽平; 孟镇; 钟其顶; 熊正河; 邹慧君; 肖冬光

    2011-01-01

    从黄酒发酵液中分离得到6株乳酸菌,16S rDNA序列分析和生理生化鉴定结果表明:菌株R1、R4、R5、R8、R20为Lactobacillus rossiae,菌株R2为Lactobacillus casei。采用平板检测法对6株乳酸菌产生物胺能力进行了评价,结果显示只有乳酸菌R1具有产生物胺的能力。利用HPLC检测对平板检测结果进行了验证,结果表明乳酸菌R1能产598.61mg/L的腐胺,其他菌株不具有产生物胺的能力。平板检测与HPLC检测结果相一致,表明平板检测可作为一种有效、操作简单、费用低的定性评价乳酸菌产生物胺能力的手段。%Six strains of lactic acid bacteria were obtained from the fermentation broth of Chinese rice wine. By using methods of physiological-biochemical and 16S rDNA tests, strains R1, R4, R5, R8 and R20 were identified as LactobaciUus rossiae, and strain R2 was identified as LactobaciUus casei. The ability of producing biogenic amines by these strains was evaluated by MRS plates and showed that only strain R1 could produce biogenic amines. HPLC confirmed that strain R1 could produce 598.61mg/L putrescine,and the others could not produce biogenic amines. The consistency of the results indicated that MRS plates analysis could be used as an effective, simple and economical method to evaluate the lactic acid bacteria's ability of producing biogenic amines.

  8. Isolation and Purification of Antifungal Components from Trichoderma harzianum Ferment Broth by High-Speed Counter-Current Chromatography%高速逆流色谱法从哈茨木霉发酵液中分离纯化抑菌活性成分

    Institute of Scientific and Technical Information of China (English)

    沙莎; 刘雷; 潘顺; 王为民

    2013-01-01

      本文采用高速逆流色谱法(HSCCC),以正己烷:乙酸乙酯:甲醇:水=7:3:5:5(v/v/v/v)作为两相溶剂体系,直接从哈茨木霉菌 Trichoderma harzianum 发酵液的乙酸乙酯提取液中分离出对立枯丝核菌Rhizoctonia solani有抑制作用的主要活性成分,经FTICR质谱及核磁共振鉴定为木霉菌素trichodermin(每324.3 mg的乙酸乙酯提取物中分离得到4 mg),对水稻纹枯病菌Thanatephorus cucmeris菌丝生长毒力EC50及EC90分别为0.69μg·mL−1、3.02μg·mL−1,此方法可用于扩大制备木霉菌素trichodermin。此外高速逆流色谱法还得到了另一对立枯丝核菌Rhizoctonia solani有明显抑制效果的活性混合组分。%We developed a high-speed counter-current chromatography (HSCCC) method and identified the major antifungal components isolated from Trichoderma harzianum broth after extraction with ethyl acetate. The HSCCC conditions were optimized and a two-phase solvent system containing n-hexane:ethyl acetate:methanol:water=7:3:5:5 (v/v/v/v) was selected for the investigation. One pure and active compound was elucidated as trichodermin using NMR and FTICR mass spectroscopy. Trichodermin exerted a potent activity in vitro against mycelial growth of Thanatephorus cucmeris with EC50=0.69 μg·mL−1 and EC90=3.02μg·mL−1. This optimized HSCCC method can be scaled up to produce a larger amount of purified trichodermin.

  9. 寡雄腐霉发酵液对烤烟的促生及防黑胫病效应分析%Effect of Pythium oligandrum broth on growth promotion and black shank control of flue-cured tobacco

    Institute of Scientific and Technical Information of China (English)

    贾瑞莲; 耿明明; 李艳; 段玉琪; 杜如万; 吴叶宽; 黄建国

    2016-01-01

    为了研制高效、无毒、成本低廉的生物农药,安全有效地防治烟草黑胫病,利用自主分离的寡雄腐霉生防菌株(Pythium oligandrum CQ2010)制备发酵液(Pythium oligandrum broth,POB),通过拮抗、盆栽和田间试验研究了POB对烤烟生长和黑胫病的防治效果,以及对小鼠的急性毒性.拮抗试验表明,POB能显著抑制离体烟草黑胫病菌的菌丝生长和孢子萌发.在盆栽试验中,POB能显著提高烟草叶片叶绿素含量(质量分数),增强烟株根系活力,增加烤烟对氮、磷、钾的吸收,促进烟苗生长,生物量比对照提高58.91%,效果优于寡雄腐霉卵孢子制剂.POB还能激活烟草叶片中与抗病性相关酶如过氧化物酶和过氧化氢酶的活性,诱导烟株产生抗病性反应,有利于消除活性氧和过氧化氢,使病害减轻.烤烟幼苗接种黑胫病菌后,施用POB使烟株发病率下降42.95%~65.77%,相对防治效果达到46.99%~57.32%,并显著降低烟草叶片中丙二醛含量,减轻病原菌对细胞膜的伤害.在田间试验中,POB对烟草黑胫病的防治效果达47.91%,烟叶产量提高44.47%,产值增加36.33%.小鼠急性毒性试验表明,用POB大剂量灌胃给药对小鼠体质量无显著影响,供试小鼠外观和行为均无异常,心、肝、肾、肺等器官未见病理改变.因此,POB能有效防治烟草黑胫病,促进烟株生长,提高烟叶产量和产值,且对动物安全无毒.%In order to develop efficient, nontoxic and cost-effective bio-control agents against tobacco black shank, antagonism, pot and field experiments were carried out to study the effects of fermentation broth produced from a self-isolated Pythium oligandrum (strain CQ2010) on the growth and control of black shank for flue-cured tobacco, and its acute toxicity to mice. The results of antagonism experiment indicated that Pythium oligandrum broth (POB) significantly inhibited mycelial growth and spore germination of in vitro Phytophora nicotiana

  10. 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.  

  11. 发酵法制备L-鸟氨酸苯乙酸盐的结晶工艺%Preparation of crystalline L-ornithine phenylacetate from L-ornithine fermentation broth

    Institute of Scientific and Technical Information of China (English)

    丁俊峰; 朱超; 黄志旭; 万红贵

    2015-01-01

    L-鸟氨酸发酵液经膜分离、离子交换处理,再加入苯乙酸进行反应,制备结晶型L-鸟氨酸苯乙酸盐(OP).采用单因素试验考察了晶种加入时机、晶种投加量、乙醇滴加速率及搅拌速率等因素对所得平均粒径及纯度的影响.确定起始质量浓度为800 g/L结晶液的较优结晶工艺条件为:乙醇与起始结晶液体积比为0.4时投加4wt%晶种,乙醇滴加速率0.8 mL/min,搅拌速率200 r/min.所得OP晶体平均粒径为614.7 μm,纯度为98.3%,总收率为72%;将其X-射线粉末衍射图谱与文献图谱比对,确定所制备的晶体为OP晶体.%Herein crystalline L-ornithine phenylacetate was prepared by complexation of L-ornithine fermentation broth pretreated by membrane separation and ion exchange with benzene acetic acid.The influences of the adding time and amount of seed crystals,dropping speed of ethanol and stirring rate on the average particle size and purity of the crystalline were investigated by single factor test.The optimal crystallization conditions for mother liquid with a primary concentration of 800 g/L were as follows:4wt% seed crystals were used when the volume ratio of anhydrous ethanol to initial crystal liquor was 0.4,together with a dropping rate of 0.8 mL/min for ethanol and a stirring rate of 200 r/min.The mean diameter of the final product was 614.7 μm and its purity was 98.3%.The total yield of the final product was 72%.The obtained product was identified by comparing its X-ray powder diffraction pattern with the literature.

  12. 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.

  13. 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.

  14. 中空纤维膜非接触式萃取-反萃分离发酵液中丁酸的研究%Non-contact extraction and back extraction of butyric acid from fermentation broth by using Hollow-Fiber membrane

    Institute of Scientific and Technical Information of China (English)

    罗兰萍; 肖凯军; 蔡谨; 徐志南; 岑沛霖

    2012-01-01

    摘要:以丁酸发酵液为原料,采用聚偏氟乙烯PVDF中空纤维膜对发酵液中高浓度的丁酸进行了萃取一反萃研究。考察了发酵液初始pH、丁酸初始浓度、发酵液流速、有机相流速及反萃剂流速对丁酸分离效果的影响,通过响应曲面法确定了最佳工艺条件。结果表明,发酵液初始pH对丁酸分离效果影响最大,发酵液流速及丁酸初始浓度次之,萃取相及反萃剂流速对分离效果影响不大。在萃取相与反萃剂流速均为90mL/min。发酵液流速为129mL/min,发酵液中丁酸含量为74.5mg/mL,发酵液初始pH为2.2时,丁酸最高回收率为85.22%。%The extraction of butyric acid from fermentation broth across microporous hollow fibers to an organic phase and then back extraction to stripping agent was studied. Effects of various factors including the initial pH of butyric acid, the concentration of butyric acid ,the flow rate of fermentation broth ,organic phase and stripping agent on extraction yield were investigated ,and the optimum process conditions were determined by response surface methodology, Results showed that the initial pH of butyric acid had exerted a great influence on the butyric acid separation comparing with other factors. The highest recovery rate of butyric acid was 85.22% when fermentation broth was treated at an initial pH of 2.2 and butyric acid concentration of 74.5mg/mL and the flow rate of fermentation broth, the organic phase and stripping agent were 129mL/min, 90mL/min, respectively.

  15. 盐生海芦笋来源真菌Penicillium stoloniferum发酵产物抗肿瘤活性成分研究%Separation, Identification and Bioactivity of Anti-Tumor Components from Fermented Broth and Mycelia of Fungus Penicillium stoloniferum Derived from Salicornia herbacea

    Institute of Scientific and Technical Information of China (English)

    沈可慧; 孟晓露; 刘天行; 辛志宏

    2012-01-01

    Eight anti-tumor monomer compounds were isolated from the fermented broth and mycelia of the fungus Penicillium stoloniferum derived from Salicornia herbacea by bioassay-guided isolation method using silica gel column chromatography,Sephedex LH-20 chromatography,and semi-preparative HPLC.They were identified by physiochemical analysis and spectroscopic techniques as ergosta-7,9(11),22-trien-3-ol,ergosterol,spinasterol,5α,8α-epidioxy-(22E,24R)-23methylergosta-6,22-dien-3β-ol,tryptophan phenylalanine cyclic dipeptide,phenylalanine,dibutyl phthalate and diisobutyl phthalate.Only 5α,8α-epidioxy-(22E,24R)-23-methylergosta-6,22-dien-3β-ol,dibutyl phthalate and diisobutyl phthalate had strong cytotoxicity with IC50values of 14,34 μg/mL and 46 μg/mL,respectively,as evaluated by SRB method.%采用活性追踪的方法,对一株盐生海芦笋来源真菌Penicillium stoloniferum发酵产物中的抗肿瘤活性成分进行分离和鉴定。利用常压硅胶柱层析、Sephedex LH-20、半制备HPLC等分离方法从中分离得到8个单体化合物,通过理化性质分析及波谱学方法鉴定其化学结构分别为:麦角甾-7,9(11),22-三烯-3-醇、麦角固醇、菠菜甾醇、5α,8α-环二氧-(22E,24R)-23-甲基麦角甾-6,22-二烯-3β-醇、色氨酸-苯丙氨酸-环二肽、苯丙氨酸、邻苯二甲酸正丁酯、邻苯二甲酸异丁酯;以SRB法评价化合物的抗肿瘤活性,5α,8α-环二氧-(22E、24R)-23-甲基麦角甾-6,22-二烯-3β-醇、邻苯二甲酸正丁酯、邻苯二甲酸异丁酯对小鼠乳腺癌P388细胞具有强的细胞毒活性,IC50值分别为14、34、46μg/mL,其他化合物没有活性。

  16. Er CAPM brothætt eða kannski and-brothætt?

    OpenAIRE

    Ársæll Valfells 1972

    2013-01-01

    Meira en fimmtíu ár eru frá liðin því kenningar um aðferðir til verðlagningar fjármálaeigna komu fram hjá Treynor, Sharpe, Lintner og Mossin og notaðar eru til samhliða kenningum Sharpe, Markowitz og Miller við stýringu eignasafna. Flestar kennslubækur sem og bolur fjármálafræði hefur stuðst við framan- greindar kenningar, þó með nokkuð óbragð í munni, þar sem þeir sem reyna að beita þessum kenningum uppgötva fljótt að þær virðast betri á blaði en borði. Á síðustu 20 árum he...

  17. [Evaluation of pharmacopoeia methods for determination of antimicrobial agents, especially of natural substances].

    Science.gov (United States)

    Brantner, A

    1997-01-01

    Microbiological assays referring to antibiotics were first mentioned in 1955 in the US Pharmacopedia XV and in the Pharmacopedia of India I. In the pharmacopedias two general methods are employed: The first group of methods is grounded on diffusion (disc assay, cylinder-plate and hole-plate assay), the second one is based on the determination of optical density (turbidimetric method). Both methods involve certain problems, particularly with respect to the testing of low-active natural substances. In the course of our investigations those test methods were evaluated and the advantages and disadvantages discussed. The methods were compared to test systems not being described in the pharmacopedias (microdilution test, bioautographic TLC assay). In addition to that we examined spectrophotometrically (OD580nm) the influence of an antimicrobial substance and of a solutizer on the bacterial growth. Tetracycline hydrochloride was used as reference and naringenin as test substance. The results were analyzed with statistical methods cited in the pharmacopedias, e.g. straight-line method and compared to other common methods, e.g. analysis of variance.

  18. Comparison of methods for the enumeration of Clostridium perfringens spores in water.

    Science.gov (United States)

    Junqueira, Valéria Christina Amstalden; Neto, Romeu Cantúsio; da Silva, Neusely; Terra, Juliana Hirata

    2012-01-01

    Four methods for enumerating Clostridium perfringens spores in water were evaluated: (1) the IMM (Iron Milk Medium) method (MPN); (2) the LS (Lactose Sulfite Broth) method (MPN); (3) the m-CP (membrane filtration Clostridium perfringens Agar) method (membrane filtration); and (4) the TSC (Tryptose Sulfite Cycloserine Agar) method (membrane filtration). The performance of these methods was compared with that of the DRCM (Differential Reinforced Clostridium Medium) method (MPN) as adopted by CETESB (Brazil's Environmental Sanitation Technology Company) for the analysis of C. perfringens spores in water. Statistical analysis was performed according to ISO 17994:2004 (Water Quality - Criteria for Establishing Equivalence between Microbiological Methods). The LS, m-CP, and TSC methods were considered not equivalent to the DRCM method, as they gave significantly lower results. The IMM showed inconclusive results and, according to ISO 17994:2004, analysis of a greater number of samples is needed to draw definitive conclusions comparing IMM and DRCM.

  19. Separation of Crocin and Picrocrocin from Saffron Cell Culture Broth by Macroporous Resin Adsorption%利用大孔吸附树脂吸附分离藏红花细胞培养液中藏红花素和藏红花苦素

    Institute of Scientific and Technical Information of China (English)

    吴频梅; 袁丽红; 黄晶; 孙镇

    2011-01-01

    Objective: The separation of crocin and picrocrocin from saffron cell culture broth was investigated by macroporous resin adsorption.Methods: The effectiveness of 4 types of macroporous resin was compared in separating crocin and picrocrocin.The application of HPD-100A resin for separating crocin and picrocrocin from saffron cell culture broth was optimized.Results: HPD-100A resin was the best resin to separate crocin and picrocrocin from saffron cell culture broth among the investigated ones.The best separation of crocin and picrocrocin was achieved as an adsorption rate of 94.4% and 75.5% and a desorption rate of 99.9% and 87.5%,respectively when the cell culture broth was concentrated until a concentration of 1.0 mg/mL and 24.6 mg/mL for crocin and picrocrocin,respectively,temperature 25 ℃,pH 6,and 1.5 BV of each concentrate was loaded onto the column at a flow rate of 1.5 mL/min after being adjusted to pH 6 and then eluted with 1.7 BV of 40% aqueous ethanol at a flow rate of 1.0 mL/min.Conclusion: Macroporous resin adsorption is feasible and holds promise for separating crocin and picrocrocin from saffron cell culture broth.%目的:研究大孔树脂提取藏红花细胞培养液中藏红花素和藏红花苦素的工艺。方法:对4种大孔树脂提取藏红花素和藏红花苦素的效果进行比较,考察HPD-100A大孔树脂提取藏红花素和藏红花苦素的最佳工艺条件。结果:HPD-100A树脂提取藏红花素和藏红花苦素效果最佳,其最适工艺条件为25℃、色素液pH6、藏红花素和藏红花苦素上样质量浓度分别为1.0mg/mL和24.6mg/mL、溶液处理量1.5BV、吸附流速1.5mL/min、洗脱剂为体积分数40%乙醇溶液、洗脱剂体积1.7BV、洗脱流速1.0mL/min。藏红花素和藏红花苦素的吸附率分别达到94.4%和75.5%,解吸率分别为99.9%和87.5%。结论:采用大孔吸附树脂吸附分离藏红花培养液中藏红花素和藏红花苦素方法可行,前景广阔。

  20. Study on the incidence of Salmonella enteritidis in Poultry and meat Samples by Cultural and PCR Methods

    Directory of Open Access Journals (Sweden)

    Putturu Ramya

    Full Text Available Aim: To study the incidence of S.enteritidis in poultry and meat samples by cultural and PCR methods. Materials and Methods: A total of 130 samples (25 each of chicken, mutton, poultry faeces, cloacal samples and 10 each of liver, spleen and kidney collected from different sources were subjected to cultural and PCR methods for the presence of Salmonella and Salmonella enteritidis. Primers for invA and sefA gene were used for Salmonella and S.enteritidis respectively. Results: Out of 130 samples, 87 were positive for Salmonella spp. i.e. chicken-16(64%, mutton-12(48%, faeces-23(92%, cloacal swabs-23(92%, liver-5(50%, spleen and kidney samples-4(40% each by PCR methods, whereas 77 were positive by cultural method i.e. chicken-14(56%, mutton-10(40%, faeces-22(88%, cloacal swabs-21(84%, liver-4(40%, spleen and kidney-3(30% each. Out of 87 positive for Salmonella by PCR method, 59(chicken-12, mutton-7, faeces-17, cloacal swabs-15, liver-3, spleen-2, kidney-3 were positive for S.enteritidis. High incidence of S.enteritidis (68% in all the above samples are indicative of unhygienic conditions in poultry farms. Selective enrichment with Rappaport-Vassilidias (RV broths and Tetrathionate (TT broths were superior over Selenite-F (SF and Selenite cysteine (SC broths. Conclusions: High incidence of S.enteritidis was seen in most of poultry samples like chicken, kidney, liver and it's faeces than mutton, which was indicative of contamination of S.enteritidis is more prevalent in poultry farms. [Vet World 2012; 5(9.000: 541-545

  1. 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.

  2. Presence of an Active Efflux System in the Fluoroquinolones Resistance of Mycoplasma Hominis

    Institute of Scientific and Technical Information of China (English)

    姚艳冰; 吴移谋; 朱翠明; 曾铁兵; 曾焱华

    2003-01-01

    Objective: To investigate the possible presence of an active efflux system in resistance to fluoroqninolones in Mycoplasma hominis. Methods: The resistant strains of M. hominis were selected from one hundred and three clinical strains of M. homlnls by broth microdilution method. The ac-cumulation of ciprofloxacin in M. hominis and the in-fluence of carbonyl cyanide m-chlorophenyl- hydrazone (CCCP) and reserpine were measured by a fluores-cence method. Results: Two resistant strains and two susceptible strains of M. hominis were selected in vitro. The accu-mulation of ciprofloxacin for resistant strains is lower than that of susceptible strains. CCCP and reserpine had different influence on clinical strains of M.hominis. Reserpine could dramatically increase the accumulation of ciprofloxacin, however CCCP had a little effect on it. Conclusion: These results suggest that the pres-ence of an active efflux system implicated in the fluoroouinolones-resistant in M. hominis.

  3. 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:

  4. Microdilution in vitro antifungal susceptibility of Exophiala dermatitidis, a systemic opportunist

    NARCIS (Netherlands)

    H. Badali; G.S. de Hoog; M. Sudhadham; J.F. Meis

    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: po

  5. Miniaturized Antimicrobial Susceptibility Test by Combining Concentration Gradient Generation and Rapid Cell Culturing

    Directory of Open Access Journals (Sweden)

    Samuel C. Kim

    2015-10-01

    Full Text Available Effective treatment of bacterial infection relies on timely diagnosis and proper prescription of antibiotic drugs. The antimicrobial susceptibility test (AST is one of the most crucial experimental procedures, providing the baseline information for choosing effective antibiotic agents and their dosages. Conventional methods, however, require long incubation times or significant instrumentation costs to obtain test results. We propose a lab-on-a-chip approach to perform AST in a simple, economic, and rapid manner. Our assay platform miniaturizes the standard broth microdilution method on a microfluidic device (20 × 20 mm that generates an antibiotic concentration gradient and delivers antibiotic-containing culture media to eight 30-nL chambers for cell culture. When tested with 20 μL samples of a model bacterial strain (E. coli ATCC 25922 treated with ampicillin or streptomycin, our method allows for the determination of minimum inhibitory concentrations consistent with the microdilution test in three hours, which is almost a factor of ten more rapid than the standard method.

  6. Ericoside, a new antibacterial biflavonoid from Erica mannii (Ericaceae).

    Science.gov (United States)

    Bitchagno, Gabin Thierry M; Tankeo, Simplice B; Tsopmo, Apollinaire; Simo Mpetga, James D; Tchinda, Alembert T; Fobofou, Serge Alain T; Nkuete, Antoine Honoré L; Wessjohann, Ludger A; Kuete, Victor; Tane, Pierre

    2016-03-01

    A new dihydroflavonol-flavonol biflavonoid derivative, named ericoside was isolated from the ethanol extract of the whole plant of Erica mannii along with the known flavonoid, taxifolin 3-O-α-L-rhamnopyranoside; and two readily available sterols (sitosterol, sitosterol 3-O-β-D-glucopyranoside). The isolation was performed using chromatographic methods and the structure of purified molecules were elucidated using spectroscopic techniques (e.g. MS, NMR) and by comparison with literature data. The crude ethanol extract, ericoside, and taxifolin 3-O-α-L-rhamnopyranoside were tested against ten Gram-negative bacteria including multidrug resistant clinical isolates using a broth microdilution method. The crude ethanol extract showed no noteworthy activity. Of the purified compounds, ericoside displayed moderate activity against the resistant Escherichia coli AG100 with a MIC of 64 μg/mL. PMID:26802608

  7. 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. PMID:22582985

  8. An efficient synthesis of 3'-indolyl substituted pyrido[1,2-]benzimidazoles as potential antimicrobial and antioxidant agents

    Indian Academy of Sciences (India)

    Harshad G Kathrotiya; Manish P Patel

    2013-09-01

    A new class of indole-based pyrido[1,2-]benzimidazole derivatives 4a-r have been synthesized by one-pot cyclocondensation reaction of 2-phenyl-1-indole-3-carboxaldehyde 1a-i, malononitrile 2 and 2-cyanomethylbenzimidazole 3a-b in the presence of catalytic amount of NaOH. In vitro antimicrobial activity of the synthesized compounds were investigated against a representative panel of pathogenic strains specifically 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. In vitro antioxidant activity was evaluated by ferric-reducing antioxidant power (FRAP) assay method. Compounds 4c, 4e, 4l and 4q have been found to be most efficient antimicrobial members while compounds 4h and 4p possess better ferric reducing antioxidant power.

  9. Direct and indirect antimicrobial effects of α-mangostin on pathogenic microorganisms

    Institute of Scientific and Technical Information of China (English)

    Nurul Huda Syed Ibrahim; Muhammad Taher; Deny Susanti; Qamar Uddin Ahmed

    2014-01-01

    Objective: To test direct and indirect antimicrobial properties of α-mangostin towards a number of bacteria and fungi.Methods:Activity of α-mangostin paired with an antibiotic was studied by calculating its fractional inhibitory concentration (FIC).Results:The experiment was carried out using broth microdilution and checkerboards methods. tetracycline showed no interaction with the combination with α-mangostin where the FIC indexes were between the range of 0.54. Activity of doxycycline on Pseudomonas aeruginosa fell into other set of range, FICindex≥4 which is an antagonism. The activity of all four bacteria towards ampicillin, penicillin G, streptomycin and Conclusions: The FIC index is far away in the range. The coupled antibiotic and α-mangostin is considered synergy in action if it lies in FICindex≤0.5 and it was found that the isolated compound,α-mangostin revealed very low synergistic antimicrobial effects when coupled with antibiotics.

  10. A comparison of standard cultural methods for the detection of foodborne Salmonella.

    Science.gov (United States)

    D'Aoust, J Y; Sewell, A M; Warburton, D W

    1992-05-01

    The sensitivity of the standard cultural method of the International Organization for Standardization (ISO 6579 and ISO 3565 combined) was compared to that of the Health Protection Branch (HPB) procedure for the detection of foodborne Salmonella. Of 195 foods tested, 84 (43.1%) were found to contain salmonellae by one or more cultural conditions. Of these, 75 (89.3%) and 68 (81.0%) were identified by the ISO and HPB methods, respectively. The apparent lack of agreement between both methods likely stemmed from the low indigenous numbers of salmonellae in several food homogenates, and unequal transfer of the target microorganism into homologous ISO and HPB pre-enrichment broths. The sensitivities of the commercially available Muller-Kauffmann tetrathionate broth (MKTBG43, Oxoid CM343), and a closely-related medium prepared with Oxoid CM29 tetrathionate base varied from 86.9 to 89.3%, and were deemed equivalent to that obtained with the ISO formulation of MKTBG43 (89.3%). Comparatively fewer contaminated samples were identified from selenite cystine (SC35) and selenite brilliant green (SBG35) enrichment cultures (82.1-83.3%). The high selectivity and saccharide-independent response of the bismuth sulfite agar medium warrants its consideration as a mandatory plating medium in ISO methodologies for the effective detection of typical and atypical biotypes of foodborne Salmonella spp.

  11. A microtiter assay shows effectivness of fungicides for control of Colletotrichum spp from strawberry

    Science.gov (United States)

    The anthracnose pathogens, Colletotrichum acutatum, C. gloeosporioides and C. fragariae, have developed resistance to some fungicides. We used a micro-dilution broth assay to test in vitro the activity of 16 chemicals against ten isolates of Colletotrichum spp. using a dose-response format. At a c...

  12. Oral antibiotics for infections due to multidrug-resistant Gram-negative organisms.

    Science.gov (United States)

    Glasser, Jessie S; Markelz, Ana E; Zera, Wendy C; Beckius, Miriam L; Mende, Katrin; Murray, Clinton K

    2011-08-01

    We determined minimum inhibitory concentrations of rifampicin, nitrofurantoin, amoxicillin-clavulanic acid, and cefdinir, plus a combination of amoxicillin-clavulanic acid and cefdinir by broth microdilution for mainly wound isolates of Escherichia coli and Klebsiella pneumoniae. E. coli and K. pneumoniae susceptibilities increased by combining amoxicillin-clavulanic acid and cefdinir. PMID:21466257

  13. Activities of five new fluoroquinolones against Pseudomonas pseudomallei.

    OpenAIRE

    Winton, M D; Everett, E D; Dolan, S A

    1988-01-01

    Thirty-four isolates of Pseudomonas pseudomallei were tested by a broth microdilution technique for susceptibility to amifloxacin, ciprofloxacin, enoxacin, norfloxacin, and ofloxacin. Ciprofloxacin was the most active agent tested, with an MIC for 90% of the strains tested of 8 micrograms/ml. These in vitro results suggest that the fluoroquinolones tested would not be optimal for therapy of melioidosis.

  14. Synergistic activity of chloroquine with fluconazole against fluconazole-resistant isolates of Candida species.

    Science.gov (United States)

    Li, Yali; Wan, Zhe; Liu, Wei; Li, Ruoyu

    2015-02-01

    The in vitro activity of chloroquine and the interactions of chloroquine combined with fluconazole against 37 Candida isolates were tested using the broth microdilution, disk diffusion, and Etest susceptibility tests. Synergistic effect was detected with 6 of 9 fluconazole-resistant Candida albicans isolates, with Candida krusei ATCC 6258, and with all 12 fluconazole-resistant Candida tropicalis isolates.

  15. Polyclonal Mycobacterium avium infections in patients with AIDS: variations in antimicrobial susceptibilities of different strains of M. avium isolated from the same patient.

    Science.gov (United States)

    von Reyn, C F; Jacobs, N J; Arbeit, R D; Maslow, J N; Niemczyk, S

    1995-01-01

    Broth microdilution MICs were determined for pairs of strains isolated from five AIDS patients with polyclonal Mycobacterium avium infection. Four (80%) of the five patients were infected simultaneously with strains having different antimicrobial susceptibility patterns. These findings have implications for the interpretation of susceptibility data in M. avium prophylaxis and treatment trials. PMID:7790424

  16. Polyclonal Mycobacterium avium infections in patients with AIDS: variations in antimicrobial susceptibilities of different strains of M. avium isolated from the same patient.

    OpenAIRE

    von Reyn, C F; Jacobs, N J; Arbeit, R D; Maslow, J.N.; Niemczyk, S

    1995-01-01

    Broth microdilution MICs were determined for pairs of strains isolated from five AIDS patients with polyclonal Mycobacterium avium infection. Four (80%) of the five patients were infected simultaneously with strains having different antimicrobial susceptibility patterns. These findings have implications for the interpretation of susceptibility data in M. avium prophylaxis and treatment trials.

  17. Evaluation of antibacterial effects of Zataria multiflora Boiss extracts against ESBL-producing Klebsiella pneumoniae strains

    Directory of Open Access Journals (Sweden)

    Masoud Dadashi

    2016-04-01

    Full Text Available Objective: There are few therapeutic options for treatment of multidrug resistant Klebsiella pneumoniae isolates as a hospital infectious agent (nosocomial infection. The aim of this study was to evaluate the antibacterial activity of Zataria multiflora Boiss extracts against ESBL-producing Klebsiella pneumoniae strains. Materials and Methods: This study was conducted on 100 K. pneumoniae isolates from two hospitals in Tehran, Iran. Antibiotic susceptibility tests were performed by Kirby-Bauer disc diffusion and microdilution broth methods and detection of ESBL was carried out according to CLSI guidelines. The blaCTX-M-15plasmid genewas detected by PCR and sequencing methods. Extracts susceptibility test was performed by broth microdilution method.  Results: Among 100 K. pneumoniae strains, 48 (48% were ESBL positive. In this study, fosfomycin, colistin and tigecycline were more active than other antibiotics. The existence of blaCTX-M-15 was detected in 30 (62.5% of 48 ESBL-producing isolates. The chloroformic extract showed potent activity against ESBL-producing K. pneumoniae strains (MIC50 = 1.56 mg/ml and MIC90=3.12mg/ml. The MIC50 and MIC90 (The MIC50 represents the MIC value at which ≥50% of the isolates in a test population are inhibited and the MIC90 represents the MIC value at which ≥90% of the strains within a test population are inhibited were 3.12 and 6.25 mg/ml and 6.25  and 12.5 mg/ml for methanolic and acetonic extracts, respectively. Conclusions: The incidence of ESBL-producing K. pneumoniae is very high. Therefore, detection of ESBL-producing K. pneumoniae isolates is of great importance in identifying drug resistance patterns in K. pneumoniae isolates and in control of infections. Zataria multiflora may have the potential to be used against multidrug resistant organisms such as clinical isolates of ESBL-producing K. pneumoniae.

  18. 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.

  19. 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....

  20. Evaluation of different analysis and identification methods for Salmonella detection in surface drinking water sources

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Bing-Mu, E-mail: bmhsu@ccu.edu.tw [Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC (China); Huang, Kuan-Hao; Huang, Shih-Wei [Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC (China); Tseng, Kuo-Chih [Department of Internal Medicine, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, ROC (China); Su, Ming-Jen [Department of Clinical Pathology, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, ROC (China); Lin, Wei-Chen; Ji, Dar-Der [Research and Diagnostic Center, Centers for Disease Control, Taipei, Taiwan, ROC (China); Shih, Feng-Cheng; Chen, Jyh-Larng [Department of Environmental Engineering and Health, Yuanpei University of Science and Technology, HsinChu, Taiwan, ROC (China); Kao, Po-Min [Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan, ROC (China)

    2011-09-15

    The standard method for detecting Salmonella generally analyzes food or fecal samples. Salmonella often occur in relatively low concentrations in environmental waters. Therefore, some form of concentration and proliferation may be needed. This study compares three Salmonella analysis methods and develops a new Salmonella detection procedure for use in environmental water samples. The new procedure for Salmonella detection include water concentration, nutrient broth enrichment, selection of Salmonella containing broth by PCR, isolation of Salmonella strains by selective culture plates, detection of possible Salmonella isolate by PCR, and biochemical testing. Serological assay and pulsed-field gel electrophoresis (PFGE) can be used to identify Salmonella serotype and genotype, respectively. This study analyzed 116 raw water samples taken from 18 water plants and belonging to 5 watersheds. Of these 116, 10 water samples (8.6%) taken from 7 water plants and belonging to 4 watersheds were positive for a Salmonella-specific polymerase chain reaction targeting the invA gene. Guided by serological assay results, this study identified 7 cultured Salmonella isolates as Salmonella enterica serovar: Alnaby, Enteritidis, Houten, Montevideo, Newport, Paratyphi B var. Java, and Victoria. These seven Salmonella serovars were identified in clinical cases for the same geographical areas, but only one of them was 100% homologous with clinical cases in the PFGE pattern. - Research highlights: {yields} A new Salmonella detecting procedure for environmental water is developed. {yields} Salmonella isolates are identified by serological assay and PFGE. {yields} A total of seven Salmonella serovars is isolated from environmental water.

  1. 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

    2015-04-01

    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.

  2. Modification to the AOAC Sporicidal Activity of Disinfectants Test (Method 966.04): collaborative study.

    Science.gov (United States)

    Tomasino, Stephen F; Hamilton, Martin A

    2006-01-01

    In an effort to improve AOAC Method 966.04, the Sporicidal Activity of Disinfectants Test, selected modifications to the procedure were evaluated in a collaborative study. Method 966.04 is used to generate efficacy data to support the product registration of sporicides and sterilants. The method is a carrier-based test that provides a qualitative measure of product efficacy against spores of Bacillus subtilis and Clostridium sporogenes. The use of garden soil extract and the lack of standard procedures for the enumeration of spores and neutralization of the test chemicals have been considered problematic for many years. The proposed modifications were limited to the B. subtilis and hard surface carrier (porcelain penicylinder) components of the method. The study included the evaluation of a replacement for soil extract nutrient broth and an establishment of a minimum spore titer per carrier, both considered crucial for the improvement and utilization of the method. Additionally, an alternative hard surface material and a neutralization confirmation procedure were evaluated. To determine the equivalence of the proposed alternatives to the standard method, 3 medium/carrier combinations, (1) soil extract nutrient broth/porcelain carrier (current method), (2) nutrient agar amended with 5 microg/mL manganese sulfate/porcelain carrier, and (3) nutrient agar amended with 5 microg/mL manganese sulfate/stainless steel carrier were analyzed for carrier counts, HCI resistance, efficacy, quantitative efficacy, and spore wash-off. The test chemicals used in the study represent 3 chemical classes and are commercially available antimicrobial liquid products: sodium hypochlorite (bleach), glutaraldehyde, and a combination of peracetic acid and hydrogen peroxide. Four laboratories participated in the study. The results of the spore titer per carrier, HCI resistance, efficacy, and wash-off studies demonstrate that amended nutrient agar in conjunction with the porcelain is comparable

  3. In Vitro Activity of the New Ketolide Telithromycin Compared with Those of Macrolides against Streptococcus pyogenes: Influences of Resistance Mechanisms and Methodological Factors

    Science.gov (United States)

    Bemer-Melchior, Pascale; Juvin, Marie-Emmanuelle; Tassin, Sandrine; Bryskier, Andre; Schito, Gian Carlo; Drugeon, Henri-B.

    2000-01-01

    One hundred and seven clinical isolates of Streptococcus pyogenes, 80 susceptible to macrolides and 27 resistant to erythromycin A (MIC >0.5 μg/ml), were examined. The erythromycin A-lincomycin double-disk test assigned 7 resistant strains to the M-phenotype, 8 to the inducible macrolide, lincosamide, and streptogramin B resistance (iMLSB) phenotype, and 12 to the constitutive MLSB resistance (cMLSB) phenotype. MICs of erythromycin A, clarithromycin, azithromycin, roxithromycin, and clindamycin were determined by a broth microdilution method. MICs of telithromycin were determined by three different methods (broth microdilution, agar dilution, and E-test methods) in an ambient air atmosphere and in a 5 to 6% CO2 atmosphere. Erythromycin A resistance genes were investigated by PCR in the 27 erythromycin A-resistant isolates. MICs of erythromycin A and clindamycin showed six groups of resistant strains, groups A to F. iMLSB strains (A, B, and D groups) are characterized by two distinct patterns of resistance correlated with genotypic results. A- and B-group strains were moderately resistant to 14- and 15-membered ring macrolides and highly susceptible to telithromycin. All A- and B-group isolates harbored erm TR gene, D-group strains, highly resistant to macrolides and intermediately resistant to telithromycin (MICs, 1 to 16 μg/ml), were all characterized by having the ermB gene. All M-phenotype isolates (C group), resistant to 14- and 15-membered ring macrolides and susceptible to clindamycin and telithromycin, harbored the mefA gene. All cMLSB strains (E and F groups) with high level of resistance to macrolides, lincosamide, and telithromycin had the ermB gene. The effect of 5 to 6% CO2 was remarkable on resistant strains, by increasing MICs of telithromycin from 1 to 6 twofold dilutions against D-E- and F-group isolates. PMID:11036012

  4. Can herbal remedies be the answer to multidrug resistance? Profile of drug resistance in Salmonella species in Eastern Cape, South Africa

    Directory of Open Access Journals (Sweden)

    Sandeep Vasaikar

    2012-04-01

    Full Text Available Objective: The treatment of serious Salmonella infections which requires the use of cephalosporins and fluoroquinolones is being compromised by the emergence of extended-spectrum beta-lactamases (ESBLs. This study reports the antibiotic profile of Salmonella species, highlighting increasing ESBLs trends in Salmonella spp. and the emergence of multi-drug resistance (MDR. To proffer solution to the problem of MDR, screening of selected herbal plants was carried out. Methods: 142 consecutive isolates of Salmonella spp. collected over a period of 4 years were tested for antibiotic resistance. Antibiogram, ESBL phenotype and confirmation of isolate were determined using a semi-automated antibiotic test. Tests were performed based on Clinical Laboratory Standards Institute standards for broth microdilution methods and interpretation using Escherichia coli ATCC 25922 as the control strain. Antibiotic resistant patterns were determined, ranking order of importance as percent (% of each type of resistance. Twelve plants selected based on ethnobotanical survey information as remedy in the treatment of stomach related ailments were screened using broth microdilution methods against strains of Salmonella, Shigella, Escherichia, Staphylococcus, Pseudomonas and Enterococcus. Results: A greater proportion of isolates were obtained from invasive cultures. Of the Salmonella isolates, there was a striking predominance of S.enterica serotype Typhi followed by S.enterica serotype Typhimurium. Most species showed pentavalent resistance to commonly used drugs. Antimicrobial resistance in S.enterica serotype Typhi is visibly increasing. Of growing concern is the increase in strains exhibiting ESBLs. Plant screening revealed promising therapeutic values in Aloe arborescens, A.striatula, and Psidium guajava. Conclusion: Increasing MDR in Salmonella serovars involved ESBLs’ production. Plants with significant antibacterial activities were comparable to the tested

  5. Functional Ginger Extracts from Supercritical Fluid Carbon Dioxide Extraction via In Vitro and In Vivo Assays: Antioxidation, Antimicroorganism, and Mice Xenografts Models

    Directory of Open Access Journals (Sweden)

    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.

  6. Quantitative differences in antibiotic resistance between methicillin-resistant and methicillin-susceptible Staphylococcus aureus strains isolated in Hungary, Austria and Macedonia.

    Science.gov (United States)

    Horvath, A; Rozgonyi, F; Pesti, N; Kocsis, E; Malmos, G; Kristof, K; Nagy, K; Lagler, H; Presterl, E; Stich, K; Gattringer, R; Kotolacsi, G; Cekovska, Z; Graninger, W

    2010-08-01

    The aim of this study was to compare the quantitative susceptibility of methicillin-resistant and -susceptible Staphylococcus aureus (MRSA and MSSA) strains from three European countries to nine antistaphylococcal agents. The antibiotic susceptibility of 274 MRSA and 284 MSSA strains from Hungary, Austria and macedonia was tested by the broth microdilution method. The clonal relationship of strains was determined by pulsed-field gel electrophoresis. Intermediate susceptibility to vancomycin appeared in Macedonian MRSA strains. Macedonian MRSA strains had high-level amikacin and gentamicin resistance. MSSA strains generally were susceptible to all drugs at minimum inhibitory concentrations (MIC(50)) except for gentamicin resistance in Macedonian strains. In Hungary and Austria a common antibiotic resistance phenotype of MRSA predominated, while in macedonia three other phenotypes were also prevalent. Geographical differences in the resistance of S. aureus are still high. Since resistance levels of MRSA and MSSA strains differ extensively, they should be considered separately for antibiotic resistance analysis.

  7. SYNTHESIS AND BIOEVALUATION OF KETOCONAZOLE THIOSEMICARBAZONE ANALOGUES

    Directory of Open Access Journals (Sweden)

    Y. Murti

    2011-12-01

    Full Text Available Ketoconazole (KTZ is a synthetic antifungal drug used to prevent and treat fungal infections, especially in immunocompromised patients such as those with AIDS. Resistance to ketoconazole has been observed in a number of clinical fungal isolates, including C. albicans. Thus new effective agents with less toxicity against fungal infection are urgently required. With this view, ketoconazole thiosemicarbazone analogues (Compounds 1-10 were synthesized wherein condensation of different thiosemicarbazides substituted by different cyclic and aromatic amines with the KTZ was done. Investigation of in-vitro antifungal activity of compounds was done by broth microdilution assay method against five pathogenic fungi Aspergillus niger, Candida albicans, Candida krusei, Candida glabrata and Candida tropicalis. Ketoconazole was used as reference for inhibitory activity against fungi. All the compounds were found potent antifungal agents, while compounds 8, 9 and 10 exhibited excellent in-vitro antifungal activity showing importance of halogenated compounds.

  8. Synthesis and antileishmanial and antimicrobial activities of some 2,3-disubstituted 3H-quinazolin-4-ones.

    Science.gov (United States)

    Arfan, Muhammad; Khan, Rasool; Khan, Murad Ali; Anjum, Shazia; Choudhary, Muhammad Iqbal; Ahmad, Manzoor

    2010-08-01

    A series of 2,3-disubstituted 3H-quinazolin-4-ones was synthesized. Antimicrobial activities of the synthesized compounds were investigated against Gram (+ve) and Gram (-ve) bacteria, including B. subtilis, S. aureus, S. flexneri, P. aeruginosa, and S. typhi, and six fungi, namely Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, and Candida glabrata using the broth microdilution method. Compounds 9, 11, and 12 showed significant activities against the selected bacterial cultures, while 7-10, 12, 15, and 16 showed good to moderate antifungal activities. Compound 11 exhibited strongest leishmanicidal activity against Leishmania major (MHOM/PK/88/DESTO) promastigotes, while other compounds showed weak to moderate leishmanicidal activities. PMID:20235747

  9. 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.

  10. 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.

  11. One step synthesis of pyrido[1,2-α]benzimidazole derivatives of aryloxypyrazole and their antimicrobial evaluation

    Institute of Scientific and Technical Information of China (English)

    Hardik H.Jardosh; Chetan B.Sangani; Manish P.Patel; Ranjan G.Patel

    2013-01-01

    A new series of pyrido[1,2-α]benzimidazole derivatives bearing the aryloxypyrazole nucleus have been synthesized by base-catalyzed cyclocondensation reaction through multi-component reaction (MCR) approach.All the synthesized compounds were investigated against a representative panel of pathogenic strains using broth microdilution minimum inhibitory concentration (MIC) method for their in vitro antimicrobial activity.Reviewing the data,majority of the compounds were found to be active against employed pathogens.SAR study explores that antimicrobial activity is strongly depends on the nature of the substituents at the ether linked aryl ring attached to the pyrazole unit,together with the substituent present on the C5 of the benzimidazole unit.

  12. 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.

  13. Norsesquiterpene hydrocarbon, chemical composition and antimicrobial activity of Rhaponticum carthamoides root essential oil.

    Science.gov (United States)

    Havlik, Jaroslav; Budesinsky, Milos; Kloucek, Pavel; Kokoska, Ladislav; Valterova, Irena; Vasickova, Sona; Zeleny, Vaclav

    2009-02-01

    A detailed analysis of Rhaponticum carthamoides (Willd.) Iljin root essential oil was carried out by GC, GC-MS and GC-FTIR techniques. In total, 30 components were identified, accounting for 98.0% of total volatiles. A norsesquiterpene 13-norcypera-1(5),11(12)-diene (22.6%), followed by aplotaxene (21.2%) and cyperene (17.9%), were isolated and their structures confirmed by 1D and 2D-NMR spectra (COSY, ROESY, HSQC, HMBC and INADEQUATE). Selinene type sesquiterpenes and aliphatic hydrocarbons were among minor constituents of the essential oil. The oil exhibited antimicrobial activity against 5 of 9 strains of bacteria and yeast, when tested using broth micro-dilution method. Minimum inhibitory concentrations ranged between 32 and 256 microg/ml. PMID:19195668

  14. Synthesis and in vitro antimicrobial activity of N-arylquinoline derivatives bearing 2-morpholinoquinoline moiety

    Institute of Scientific and Technical Information of China (English)

    Jigar A. Makawana; Manish P. Patel; Ranjan G. Patel

    2012-01-01

    A new series of N-arylquinoline derivatives 5a-x bearing 2-morpholinoquinoline moiety has been synthesized by one pot base catalyzed cyclocondensation reaction of 2-morpholinoquinoline-3-carbaldehydes 2a-c,malononitrile 3 and β-enaminones 4a-h.All the synthesized compounds were screened for their in vitro antimicrobial activity against six bacterial pathogens,namely Streptococcus pneumoniae,Clostridium tetani,Bacillus subtilis,Salmonella typhi,Vibrio cholerae,Escherichia coli and against two fungal pathogens,Aspergillus fumigatus and Candida albicans using broth microdilution MIC method.Of the compounds studied,majority of the compounds were found to active against C.tetani,B.subtilis and C.albicans as compared to first-line standard drugs.

  15. 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.

  16. Composition and antimicrobial activity of the essential oil of the leaves of black currant (Ribes nigrum L. cultivar Čačanska crna

    Directory of Open Access Journals (Sweden)

    TODOR VULIĆ

    2010-01-01

    Full Text Available The essential oil from the leaves of the Serbian black currant cultivar Čačanska crna, obtained by hydrodistillation, was analyzed by gas chromato¬graphy-flame ionization detection and GC–mass spectrometry. The most abundant volatile compounds were D3-carene (18.7 %, b-caryophyllene (17.7 %, sabinene (11.6 %, cis-b-ocimene (10.6 % and a-terpinolene (10.6 %. The antimicrobial activity of the oil was evaluated against 14 micro-organisms, including two clinical isolated strains, using the broth microdilution method. The most susceptible micro-organisms were Escherichia coli, Streptococcus faecalis, Staphylococcus aureus, Candida albicans and Trichophyton mentagrophytes isolates. Furthermore, the flavonol aglycones in the leaves after acid hydrolysis were qualitatively and quantitatively analysed by HPLC, and quercetin was found to be the dominant compound (84 mg/g dw.

  17. Synthesis and antimicrobial activities of new higher amino acid Schiff base derivatives of 6-aminopenicillanic acid and 7-aminocephalosporanic acid

    Science.gov (United States)

    Özdemir (nee Güngör), Özlem; Gürkan, Perihan; Özçelik, Berrin; Oyardı, Özlem

    2016-02-01

    Novel β-lactam derivatives (1c-3c) (1d-3d) were produced by using 6-aminopenicillanic acid (6-APA), 7-aminocephalosporanic acid (7-ACA) and the higher amino acid Schiff bases. The synthesized compounds were characterized by elemental analysis, IR, 1H/13C NMR and UV-vis spectra. Antibacterial activities of all the higher amino acid Schiff bases (1a-3a) (1b-3b) and β-lactam derivatives were screened against three gram negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Acinetobacter baumannii RSKK 02026), three gram positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 07005, Bacillus subtilis ATCC 6633) and their drug-resistant isolates by using broth microdilution method. Two fungi (Candida albicans and Candida krusei) were used for antifungal activity.

  18. Susceptibility of bifidobacteria of animal origin to selected antimicrobial agents.

    Science.gov (United States)

    Mayrhofer, Sigrid; Mair, Christiane; Kneifel, Wolfgang; Domig, Konrad J

    2011-01-01

    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. PMID:22312561

  19. Antibacterial activity of commercially available plant-derived essential oils against oral pathogenic bacteria.

    Science.gov (United States)

    Bardají, D K R; Reis, E B; Medeiros, T C T; Lucarini, R; Crotti, A E M; Martins, C H G

    2016-05-01

    This work investigated the antibacterial activity of 15 commercially available plant-derived essential oils (EOs) against a panel of oral pathogens. The broth microdilution method afforded the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the assayed EOs. The EO obtained from Cinnamomum zeylanicum (Lauraceae) (CZ-EO) displayed moderate activity against Fusobacterium nucleatum (MIC and MBC = 125 μg/mL), Actinomyces naeslundii (MIC and MBC = 125 μg/mL), Prevotella nigrescens (MIC and MBC = 125 μg/mL) and Streptococcus mutans (MIC = 200 μg/mL; MBC = 400 μg/mL). (Z)-isosafrole (85.3%) was the main chemical component of this oil. We did not detect cinnamaldehyde, previously described as the major constituent of CZ-EO, in specimens collected in other countries. PMID:26165725

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

    Directory of Open Access Journals (Sweden)

    Esther Manso

    2014-12-01

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

  1. Carboxymethylated chitosan-stabilized copper nanoparticles: a promise to contribute a potent antifungal and antibacterial agent

    International Nuclear Information System (INIS)

    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

  2. Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. Synthesis and in vitro antimicrobial screening of new pyrano[4,3-b]pyrane derivatives of 1H-pyrazole

    Institute of Scientific and Technical Information of China (English)

    Chetan B. Sangani; Divyesh C. Mungra; Manish P. Patel; Ranjan G. Patel

    2012-01-01

    A new series of pyrano[4,3-b]pyrane 4a-(I) bearing 1H-pyrazole has been synthesized by one pot base catalyzed cyclocondensation reaction of 1H-pyrazole-4-carbaldehyde 1a-(1),malononitrile 2 and 4-hydroxy-6-methylpyrone 3.All the synthesized compounds were screened against six bacterial pathogens,namely B.subtilis,C.tetani,S.pneumoniae,S.typhi,V.cholerae,E.coli and antifungal activity against,two fungal pathogens,A.fumigatus and C.albicans using broth microdilution MIC method.Some of the compounds are found to be equipotent or more potent than that of commercial drugs,against most of employed strains.

  5. Antimicrobial and antifungal activities of the extracts and essential oils of Bidens tripartita.

    Directory of Open Access Journals (Sweden)

    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.

  6. Ceftaroline activity tested against contemporary Latin American bacterial pathogens (2011

    Directory of Open Access Journals (Sweden)

    Robert K. Flamm

    2014-04-01

    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.

  7. 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. PMID:27387734

  8. 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.

  9. Antibacterial activity against Clostridium genus and antiradical activity of the essential oils from different origin.

    Science.gov (United States)

    Kačániová, Miroslava; Vukovič, Nenad; Horská, Elena; Salamon, Ivan; Bobková, Alica; Hleba, Lukáš; Fiskelová, Martina; Vatľák, Alexander; Petrová, Jana; Bobko, Marek

    2014-01-01

    In the present study, the antimicrobial and antiradical activities of 15 essential oils were investigated. The antimicrobial activities were determined by using agar disc diffusion and broth microdilution methods against Clostridium genus and antioxidant properties of essential oils by testing their scavenging effect on DPPH radicals activities. We determined the antibacterial activity of Clostridium butyricum, Clostridium hystoliticum, Clostridium intestinale, Clostridium perfringens and Clostridium ramosum. We obtained the original commercial essential oils samples of Lavandula angustifolia, Carum carvi, Pinus montana, Mentha piperita, Foeniculum vulgare Mill., Pinus sylvestris, Satureia montana, Origanum vulgare L. (2 samples), Pimpinella anisum, Rosmarinus officinalis L., Salvia officinalis L., Abies alba Mill., Chamomilla recutita L. Rausch and Thymus vulgaris L. produced in Slovakia (Calendula a.s., Nova Lubovna, Slovakia). The results of the disk diffusion method showed very high essential oils activity against all tested strains of microorganisms. The best antimicrobial activity against C. butyricum was found at Pimpinella anisum, against C. hystoliticum was found at Pinus sylvestris, against C. intestinale was found at Satureia hortensis L., against C. perfringens was found at Origanum vulgare L. and against C. ramosum was found at Pinus sylvestris. The results of broth microdilution assay showed that none of the essential oils was active against C. hystoliticum. The best antimicrobial activity against C. butyricum was found at Abies alba Mill., against C. intestinale was found at Abies alba Mill., against C. perfringens was found at Satureia montana and against C. ramosum was found at Abius alba and Carum carvi. Antioxidant DPPH radical scavenging activity was determined at several solutions of oil samples (50 μL.mL(-1)-0.39 μL.mL(-1)) and the best scavenging effect for the highest concentration (50 μL.mL(-1)) was observed. The antioxidant properties

  10. A rapid method for the nonselective enumeration of Yersinia enterocolitica, a foodborne pathogen associated with pork.

    Science.gov (United States)

    Wang, Haoran; Palmer, Jon; Flint, Steve

    2016-03-01

    An impedance method was developed as a rapid, convenient method to enumerate pure culture of Yersinia enterocolitica. Cultures were incubated in trypticase soy broth (TSB) at 30°C. The BacTrac™ 4000 microorganism growth analyser was used to detect impedance change of TSB representing bacteria cell numbers in the samples. Good correlations with standard plate counts were obtained (r(2)>0.95). This method is also reliable to enumerate Y. enterocolitica growing in biofilms attached to stainless steel. Compared with a standard plate count which involves dislodging biofilms from surfaces, this method is more convenient saving both time and effort. Therefore, it will be useful to study the conditions required for the biofilm growth and control of Y. enterocolitica that could be applied to the pork industry.

  11. 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.

  12. 采用大孔吸附树脂D-101初步分离提取TJ430菌株发酵液中的抗生素%Preliminary research on the separation of an agro-antibiotic from the fermentation broth of the Streptomyces strain TJ430 by macroporous absorption resin D-101

    Institute of Scientific and Technical Information of China (English)

    黄永春; 刘红梅; 赵鹏; 张伟; 陈志永

    2013-01-01

    An agro-antibiotic extract was obtained by bioassay and HPLC.The dynamic adsorption performance of macroporous resin D-101 on the agro-antibiotic from the Streptomyces strain TJ430 fermentation broth was investigated.The influences of the adsorption and desorption time,value of pH,and concentration of acetone eluent on extraction were discussed.The results showed that D-101 resin had good adsorption ability for fermentation broth,and the optimum adsorption and desorption conditions were as follows:the adsorption and desorption time was 120 minutes,the desorption concentration of acetone was 70%,and the pH value of desorption was 6.0.The antibiotic was refined efficiently after adsorption and desorption procedure.%借助生物活性测定法和高效液相色谱法对发酵液中农用抗生素进行追踪监测,探讨了大孔吸附树脂对菌株TJ430发酵液中农用抗生素的分离纯化条件.经过对比试验发现D-101型大孔吸附树脂的吸附性能最好;最佳吸附时间为120 min; 70%丙酮水溶液的解吸附能力最佳;最佳解吸附pH为接近中性条件;最佳解吸附时间为120 min.采用D101型大孔吸附树脂对TJ430菌株发酵液中抗生素进行吸附,在中性条件下经70%丙酮水解吸附,使发酵液中抗生素得到了有效的分离纯化.

  13. Efficacy of Plectranthus amboinicus (Lour. Spreng in a Murine Model of Methicillin-Resistant Staphylococcus aureus Skin Abscesses

    Directory of Open Access Journals (Sweden)

    Francisco Fábio Martins de Oliveira

    2013-01-01

    Full Text Available The present work aimed to evaluate the effectiveness of Plectranthus amboinicus (Lour. Spreng against MRSA clinical isolates. The in vitro antimicrobial activity of the hydroalcoholic extract (HE, the ethyl acetate (EA fraction and its subfractions were determined by broth microdilution and bioautography against MRSA clinical isolates. The microdilution checkerboard method was used to assess in vitro drug combination studies. To induce abscess formation, bacterial suspensions were added to Citodex and inoculated subcutaneously into male Swiss mice. The treatment protocol consisted of 2 doses of HE, the EA fraction or vancomycin introduced intraperitoneally into mice 3 and 12 h after infection. The EA fraction and its subfractions presented the lowest minimal inhibitory concentrations (MIC, 0.25 to 0.5 mg/mL. The plant samples were bacteriostatic at 2x and 4x MIC and bactericidal at 100 mg/mL. The EA fraction presented synergism with vancomycin and an additive effect with ciprofloxacin. A significant reduction of abscess volume, bacterial cell counts in abscess slurries, and inflammatory scores was observed in the HE and EA fraction-treated groups. The samples were effective in treating the animals in a dose-dependent fashion. The present study proved the effectiveness of P. amboinicus fractions against MRSA using in vitro and in vivo assays.

  14. Efficacy of Plectranthus amboinicus (Lour.) Spreng in a Murine Model of Methicillin-Resistant Staphylococcus aureus Skin Abscesses.

    Science.gov (United States)

    de Oliveira, Francisco Fábio Martins; Torres, Alba Fabiola; Gonçalves, Thially Braga; Santiago, Gilvandete Maria Pinheiro; de Carvalho, Cibele Barreto Mano; Aguiar, Milena Braga; Camara, Lilia Maria Carneiro; Rabenhorst, Silvia Helena; Martins, Alice Maria Costa; Valença Junior, José Telmo; Nagao-Dias, Aparecida Tiemi

    2013-01-01

    The present work aimed to evaluate the effectiveness of Plectranthus amboinicus (Lour.) Spreng against MRSA clinical isolates. The in vitro antimicrobial activity of the hydroalcoholic extract (HE), the ethyl acetate (EA) fraction and its subfractions were determined by broth microdilution and bioautography against MRSA clinical isolates. The microdilution checkerboard method was used to assess in vitro drug combination studies. To induce abscess formation, bacterial suspensions were added to Citodex and inoculated subcutaneously into male Swiss mice. The treatment protocol consisted of 2 doses of HE, the EA fraction or vancomycin introduced intraperitoneally into mice 3 and 12 h after infection. The EA fraction and its subfractions presented the lowest minimal inhibitory concentrations (MIC, 0.25 to 0.5 mg/mL). The plant samples were bacteriostatic at 2x and 4x MIC and bactericidal at 100 mg/mL. The EA fraction presented synergism with vancomycin and an additive effect with ciprofloxacin. A significant reduction of abscess volume, bacterial cell counts in abscess slurries, and inflammatory scores was observed in the HE and EA fraction-treated groups. The samples were effective in treating the animals in a dose-dependent fashion. The present study proved the effectiveness of P. amboinicus fractions against MRSA using in vitro and in vivo assays. PMID:23533472

  15. Effect of Irradiation of Bacteria Upon Their Survival Rate During Conventional Methods of Meat Preservation

    International Nuclear Information System (INIS)

    The purpose of this paper is to define the effect of irradiation upon the survival rate of non-sporing bacteria (Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, Pseudomonas fluorescens) during basic methods of meat preservation. The bacteria were irradiated in broth by X-rays at a dose that destroyed about 90% of the bacteria (D10). The survival rate of unirradiated and irradiated bacteria during cooling and freezing, in solutions of sodium chloride, nitrates and liquid smoke, was defined. The number of microorganisms was determined directly after irradiation as well as 1, 3, 7, 14, 21 and 28 days after irradiation. The effect of irradiation upon heat resistance of the examined species of bacteria was also defined. The microorganisms were heated in broth, at 70°C for 1, 2 and 5 minutes. The obtained results were subjected to statistical analysis. On the basis of the research results, a faster dying rate of irradiated populations of S. aureus and E. coli during any type of preservation treatment, the lack of any reaction to irradiation regarding the survival rate of S. typhimurium, and the lack of any effect of irradiation upon the rate of deterioration of P. fluorescens during freezing and storage in a solution with 10% addition of NaCl, were observed. On the other hand, a pronounced effect of irradiation upon the lowering of the heat resistance of the bacteria, as well as delayed growth in other variants of the experiment, was determined. (author)

  16. Antifungal susceptibility testing method for resource constrained laboratories

    Directory of Open Access Journals (Sweden)

    Khan S

    2006-01-01

    Full Text Available Purpose: In resource-constrained laboratories of developing countries determination of antifungal susceptibility testing by NCCLS/CLSI method is not always feasible. We describe herein a simple yet comparable method for antifungal susceptibility testing. Methods: Reference MICs of 72 fungal isolates including two quality control strains were determined by NCCLS/CLSI methods against fluconazole, itraconazole, voriconazole, amphotericin B and cancidas. Dermatophytes were also tested against terbinafine. Subsequently, on selection of optimum conditions, MIC was determined for all the fungal isolates by semisolid antifungal agar susceptibility method in Brain heart infusion broth supplemented with 0.5% agar (BHIA without oil overlay and results were compared with those obtained by reference NCCLS/CLSI methods. Results: Comparable results were obtained by NCCLS/CLSI and semisolid agar susceptibility (SAAS methods against quality control strains. MICs for 72 isolates did not differ by more than one dilution for all drugs by SAAS. Conclusions: SAAS using BHIA without oil overlay provides a simple and reproducible method for obtaining MICs against yeast, filamentous fungi and dermatophytes in resource-constrained laboratories.

  17. Antimicrobial Susceptibility of Udder Pathogens Isolated from Dairy Herds in the West Littoral Region of Uruguay

    Directory of Open Access Journals (Sweden)

    Franklin A

    2002-03-01

    Full Text Available A total of 522 strains belonging to streptococci, enterococci and staphylococci isolated from sub-clinical and clinical cases of bovine mastitis from the west littoral region of Uruguay were analysed for their susceptibility to several antimicrobial agents. The susceptibility patterns were studied by agar disk diffusion methods (ADDM and broth micro-dilution to determine the minimum inhibitory concentration (MIC. The concentration that inhibits 90% (MIC90 of the analysed strains reported in micrograms per millilitre, for Staphylococcus aureus were > 8, 8, ≤ 0.5, ≤ 4, ≤ 1, ≤ 0.5, > 64, ≤ 0.25, 0.5, ≤ 1 and ≤ 1 to penicillin, ampicillin, oxacillin, cephalotin, gentamicin, erythromycin, oxitetracycline, enrofloxacin, trimethoprim/sulfamethoxazole, neomycin, and clindamycin, respectively. Coagulase-negative staphylococci (CNS had different values for penicillin (4 and ampicillin (2, while the other antimicrobial agents had the same MIC90 values as reported for S. aureus. The MIC90 values for streptococci were 0.12, 0.25, ≤ 4, 16, ≤ 0.25, 0.5, 0.25 for penicillin, ampicillin, cephalotin, gentamicin, erythromycin, oxytetracycline and trimethoprim-sulfamethoxazole, whereas MIC90 for enterococci were 4, 4, 4, ≤ 0.5, 2, > 8 for penicillin, ampicillin, gentamicin, erythromycin, oxytetracycline and trimethoprim-sulfamethoxazole, respectively. Of 336 strains of S. aureus, 160 (47.6% were resistant to penicillin. For 41 CNS strains, 10 (27% presented penicillin-resistance. All the streptococcal strains were susceptible to penicillin, while 3 (7% of the 43 enteroccocal strains were resistant. Non significant statistical differences were found between the results obtained by ADDM and broth micro-dilution for classifying bacterial isolates as susceptible or resistant according to the National Committee of Clinical Laboratory Standards.

  18. Antimicrobial susceptibility to parenteral and oral agents in a largely polyclonal collection of CTX-M-14 and CTX-M-15-producing Escherichia coli and Klebsiella pneumoniae.

    Science.gov (United States)

    Titelman, Emilia; Iversen, Aina; Kahlmeter, Gunnar; Giske, Christian G

    2011-12-01

    Activity of oral and parenteral antimicrobials against consecutively isolated extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (n = 149) and Klebsiella pneumoniae (n = 20) was determined, and susceptibility test methods were compared for parenteral β-lactams. Polymerase chain reaction (PCR) targeting bla(CTX-M), bla(SHV) and bla(TEM), and DNA sequencing and epidemiological typing with pulsed-field gel electrophoresis were performed. PCR targeting pabB was screened for E. coli O25b-ST131. Minimum inhibitory concentrations (MICs) were determined using Etest and broth microdilution. Disc diffusion was performed according to European Committee on Antimicrobial Susceptibility Testing (EUCAST). Dominating genotypes were bla(CTX-M-15) (75%) and bla(CTX-M-14) (23%). Four E. coli clusters (7-18 isolates) were found. Forty-two per cent of E. coli belonged to O25b-ST131. Ciprofloxacin resistance was 72%, trimethoprim resistance was 70%. Among E. coli, resistance to mecillinam (13%), nitrofurantoin (7%) and fosfomycin (3%) was low, although resistance was high in K. pneumoniae (25%, 60%, 85%). Susceptibility to ertapenem was 99%, piperacillin-tazobactam 91%, tigecycline 96% and temocillin 76%. Susceptibility rates obtained with broth microdilution and Etest were in agreement for cefotaxime (2 vs 1%) and ceftazidime (9 vs 11%), but not for piperacillin-tazobactam (59 vs 91%). With disc diffusion major errors occurred with piperacillin-tazobactam (18/169). Several therapeutic alternatives exist for ESBL-producing E. coli, but few exist for K. pneumoniae. Disc diffusion and Etest can accurately predict susceptibility to cefotaxime and ceftazidime, but not to piperacillin-tazobactam with the present breakpoints. PMID:22085361

  19. Rapid and simple colorimetric detection of Escherichia coli O157:H7 in apple juice using a novel recombinant bacteriophage-based Method.

    Science.gov (United States)

    Hoang, Hoang A; Dien, Le T

    2015-01-01

    In this study, a bacteriophage-based method for the colorimetric detection of E. coli O157:H7 in apple juice was investigated. Firstly, a gene encoding Cytochrome c Peroxidase (CCP) chromogenic enzyme was inserted into a wild type PP01 phage genome to construct the recombinant PP01ccp phage that was used in the production of the chromogenic enzyme through specific infection into E. coli O157:H7. The method was then examined in the colorimetric detection of E. coli O157:H7 in broth, and the appearance of E. coli O157:H7 in broth was confirmed by the color change after a few minutes of the enzyme assay. Secondly, the method was investigated in the colorimetric detection of E. coli O157:H7 in apple juice. A low E. coli O157:H7 concentration as 1 CFU mL(-1) was detected in 15 h that was in a shorter time than in previous bioluminescence phage-based methods. Moreover, the method is much simpler compared to other previous phage-based methods since it enables detection without the need for expensive apparatus.

  20. [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. PMID:26552129

  1. The effectiveness of novel bacteriocin derived from Escherichia coli colonized in the fermented pineapple Ananas comosus (L. Merr. against pathogenic bacteria isolated from aquaculture sites

    Directory of Open Access Journals (Sweden)

    S. W. Lee

    2014-11-01

    Full Text Available Aim: The aim was to evaluate antimicrobial property of bacteriocin isolated from Escherichia coli against pathogenic bacteria from aquaculture sites. Materials and Methods: E. coli was isolated from fermented pineapple Ananas comosus using eosin methylene blue agar. The antimicrobial activity of the isolated E. coli was screened using hole-plate diffusion method. The bacterial strain that showed the widest inhibition zone was selected and grown in tryptic soy broth, followed by partial purification of bacteriocin by using ammonium sulphate. Bacteriocin derived from the E. coli was subjected to the antimicrobial test against 55 bacteria strains namely Aeromonas hydrophila (n=10, Citrobacter freundii (n=5, Edwardsiella tarda (n=10, Flavobacterium spp. (n=10, Pseudomonas spp. (n=10, Vibrio parahaemolyticus (n=5 and Vibrio alginolyticus (n=5 by using twofold broth microdilution method to determine minimum inhibitory concentration (MIC values of the bacteriocin against the tested bacteria. Results: The results of the present study showed that the MIC values of the partially purified bacteriocin against present pathogenic bacteria isolates ranged from 7.81 to 31.25 ppm whereas the MIC values of kanamycin (positive control ranged from 15.63 to 125 ppm. Conclusion: The results of the present study showed the bacteriocin derived from E. coli can control all the present bacterial isolates indicating the huge potential of the bacteriocin as a new antimicrobial agent for aquaculture uses.

  2. In vitro activity of norfloxacin against uropathogens and drug efficacy in simulated bladder model under diabetic conditions

    Directory of Open Access Journals (Sweden)

    Anandkumar H

    2003-01-01

    Full Text Available PURPOSE: The in vitro activity of norfloxacin was determined to maximize the correlation between susceptibility testing of the drug and the results of clinical therapy of urinary tract infection in diabetics. This study was carried out to observe the effect of changing concentration of norfloxacin on the growth of uropathogens under diabetic conditions. METHODS: The standard broth microdilution method was carried out to determine the minimum inhibitory concentration (MIC using Mueller Hinton broth by varying pH of the medium (5.0, 5.5, 6.0, 6.5 and 7.0 and glucose concentration (100, 250, 500, 1000 and 2000 mg/dL. A specially designed mechanical bladder model system simulating hydrokinetic conditions that exist in the urinary tract of diabetics was employed. RESULTS: The loss of activity of norfloxacin was more pronounced (> four folds at pH 5.0 and 2000 mg/dL sugar concentration. These findings were consistent with the experiment ′in vitro simulated bladder model′ by exposing bacterial growth to varied norfloxacin and sugar concentration. CONCLUSIONS: Although norfloxacin is a drug of choice for non-diabetic and diabetic individuals with mild to moderate glucosuria, in severe diabetic individuals norfloxacin may not be an effective drug.

  3. Inhibitory activity of spices and essential oils on psychrotrophic bacteria.

    Science.gov (United States)

    Fabio, A; Corona, A; Forte, E; Quaglio, P

    2003-01-01

    This study was designed to evaluate "in vitro" the inhibitory effects of spices and essential oils on the growth of psycrotrophic food-borne bacteria: Aeromonas hydrophila, Listeria monocytogenes and Yersinia enterocolitica. The sensitivity to nine spices and their oils (chilli, cinnamon, cloves, ginger, nutmeg, oregano, rosemary, sage, thyme) was studied. Antibacterial activity was evaluated on liquid and solid medium. Spices: 1% concentration of each spice was added separately to Triptic Soy Broth and then inoculated to contain 10(8)/ml organism and held to 4 degrees C for 7 days. Populations of test organism were determined on Triptic Soy Agar. Oils: Inhibition of growth was tested by using the paper disc agar diffusion method (at 35, 20 and 4 degrees C) and measuring their inhibition zone. MIC was determined by the broth microdilution method. Some culinary spices produce antibacterial activity: inhibition of growth ranged from complete (cinnamon and cloves against A. hydrophila) to no inhibition. Antibacterial inhibition zone ranged from 8 mm to 45 mm: thyme essential oil showed the greatest inhibition against A. hydrophila. PMID:12578319

  4. Are the Best Broths Really Made in the Oldest Pots?

    DEFF Research Database (Denmark)

    Gravier, Magali

    offers the first contemporary context of use of this notion in a mainly normatively neutral way. Empire is ‘simply’ used to describe and analyze recent trends in the integration process, which nonetheless raises questions. Has this political concept been dug out of Europe’s history because...... 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...... 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...

  5. In-situ product recovery from fermentation broths

    OpenAIRE

    Van den Berg, C.

    2010-01-01

    Life sciences will be one of the decisive factors in the 21st century. A major part of this field is the so-called white biotechnology, also known as industrial biotechnology. White biotechnology is an emerging field where bio-chemicals are produced using micro-organisms. However, the production of bio-chemicals is severely inhibited due to toxicity of the product towards the host-organism. Therefore, it is necessary to remove the products from the micro-organisms’ environment. One approach f...

  6. In-situ product recovery from fermentation broths

    NARCIS (Netherlands)

    Van den Berg, C.

    2010-01-01

    Life sciences will be one of the decisive factors in the 21st century. A major part of this field is the so-called white biotechnology, also known as industrial biotechnology. White biotechnology is an emerging field where bio-chemicals are produced using micro-organisms. However, the production of

  7. Behavior of Staphylococcus aureus in culture broth, in raw and thermized milk, and during processing and storage of traditional Greek Graviera cheese in the presence or absence of Lactococcus lactis subsp. cremoris M104, a wild, novel nisin A-producing raw milk isolate.

    Science.gov (United States)

    Samelis, John; Lianou, Alexandra; Pappa, Eleni C; Bogovič-Matijašić, Bojana; Parapouli, Maria; Kakouri, Athanasia; Rogelj, Irena

    2014-10-01

    This study was conducted to evaluate the behavior of Staphylococcus aureus during processing, ripening, and storage of traditional Greek Graviera cheese in accordance with European Union Regulation 1441/2007 for coagulase-positive staphylococci in thermized milk cheeses. Lactococcus lactis subsp. cremoris M104, a wild, novel nisin A-producing (NisA+) strain, also was evaluated as an antistaphylococcal adjunct. A three-strain cocktail of enterotoxigenic (Ent+) S. aureus increased by approximately 2 log CFU/ml when co-inoculated (at approximately 3 log CFU/ml) in thermized Graviera cheese milk (TGCM; 63°C for 30 s) with commercial starter culture (CSC) and/or strain M104 at approximately 6 log CFU/ml and then incubated at 37°C for 3 h. However, after 6 h at 37°C, significant retarding effects on S. aureus growth were noted in the order TGCM + M104 > TGCM + CSC = TGCM + CSC + M104 > TGCM. Additional incubation of TGCM cultures at 18°C for 66 h resulted in a 1.2-log reduction (P nisin-encoding genes in the CSC plus M104 cheeses and their corresponding microbial consortia only. A high level of selective survival of a naturally nisin-resistant EntC z S. aureus strain from the cocktail was noted in CSC + M104 cheeses and in coculture with the NisA + M104 strain in M-17 broth. In conclusion, although S. aureus growth inhibition is assured during Graviera cheese ripening, early growth of the pathogen during milk curdling and curd cooking operations may occur. Nisin-resistant S. aureus strains that may contaminate Graviera cheese milks postthermally may be difficult to control even by the application of the NisA + L. lactis subsp. cremoris strain M104 as a bioprotective adjunct culture.

  8. Optimization of Ultrafiltration Processes in Bolistin Fermentation Broth on the Base of Polyether Sulphone (PES) Memebrane%基于聚醚砜(PES)超滤膜的粘杆菌素发酵液预处理过程优化

    Institute of Scientific and Technical Information of China (English)

    魏安静; 田丽; 凤权

    2011-01-01

    Uhrafiltration was used to pretreat colistin fermentation broth. According to the characteristics of the material and comparison of their ultrafihration separation performance, polyether sulphone ultrafiltration membrane (MWCO = 10 000) was selected. The optimum operating parameters had been determined: pressure was 0.3 MPa, pH was 6.0. Under these optimum parameters, the protein rejected ratio was 96% , absorbency was 0. 185, and part of the pigment had been removed.%利用超滤对粘杆菌素发酵液进行膜分离处理并对其工艺过程进行优化。根据膜材料特性,选择聚醚砜(PES)为基材的超滤膜,通过不同截留分子量超滤膜的分离性能比较、操作条件选择,最终确定PES-10(截留分子质量为10000u)为超滤膜件,适宜的操作压力为0.3MPa、料液pH值为6。经过超滤处理,滤液蛋白质含量为4.6mg/100mL,蛋白质去除率为96%,吸光度为0.185,发酵液中的色素得到有效地去除。

  9. Effect of the fermentation broth of a bacteriocin-producing lactobacillus plantarum YJG on the production performance and egg quality of laying hens%一株产细菌素植物乳酸杆菌YJG发酵液对蛋鸡生产性能以及蛋品质的影响

    Institute of Scientific and Technical Information of China (English)

    韩冰; 邓凯; 张日俊

    2011-01-01

    To study effect of the fermentation broth of a bacteriocin-producing Lactobacillus plantarum YJG on production performance and egg quality of laying hens. Two hundred and twenty five laying hens of 232-day-old were randomly divided into 5 treatment groups with 5 replicates, and the trials period was 34 days. The results showed that treatment with 500 AU/kg bacteriocin could enhance the average weight, and the treatments with bacteriocins could apparently reduce the feed egg ratio(P<0.05), Bacteriocins produced by Lactobacillus plantarum YJG could improve the production performance and egg quality of laying hens and provide new insight into research of feed additives.%研究一株植物乳酸杆菌细菌素对蛋鸡生产性能和蛋品质的影响.选用232日龄产蛋率和体重相近、健康状况良好的海兰灰蛋鸡225只,试验期为34 d.结果表明:日粮中添加500 AU/kg植物乳酸杆菌细菌素对蛋鸡的产蛋率和平均蛋重的提升幅度最大,各细菌素添加组对降低料蛋比均有显著的效果(P<0.05),对平均日采食量、蛋黄色泽、哈氏单位、蛋壳强度和蛋形指数都有不同程度的改善.植物乳酸杆菌细菌素可以明显改善蛋鸡生产性能和蛋品质,可以为饲料添加剂的研发提供新的思路.

  10. 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.

  11. 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.

  12. 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. PMID:22608224

  13. Isolation, molecular characteristics and disinfection of methicillin-resistant Staphylococcus aureus from ICU units in Brazil.

    Science.gov (United States)

    Campos, Guilherme B; Souza, Simone G; Lob O, Tassia N; Da Silva, Danilo C C; Sousa, Daniel S; Oliveira, Pollianna S; Santos, Verena M; Amorim, Aline T; Farias, S Vio T; Cruz, Mariluze P; Yatsuda, Regiane; Marques, Lucas M

    2012-04-01

    The aim of the present study was to isolate S. aureus strains resistant to antibiotics, characterize the genotype profiles of resistance staphylococci, and evaluate the efficacy of antiseptic agents and disinfectants used in two public hospitals of Vitoria da Conquista, Bahia, Brazil. Clinical samples were obtained from ICU environments and equipment surfaces in two public hospitals in Vitoria da Conquista. Broth cultures were plated onto mannitol salt agar, and antimicrobial susceptibility testing was performed by the broth microdilution method according to CLSI. MRSA strains were submitted to PCR for detecting the mecA gene. PCR products were purified and sequenced for SCCmec type identification. Moreover, the strains were tested for efficacy of different disinfectant solutions. S. aureus were isolated from 31 and 67 sites in each hospital, respectively. Among the isolates from hospital 1, 07 (22.6%) were resistant to oxacillin while 28 (41.8%) were resistant in hospital 2. Thirty-one were positive for the mecA gene. All isolates showed SCCmec type III genotype characteristics of the Brazilian epidemic clone. In disinfectant tests, sodium hypochlorite (0.5, 1.0 and 2.0%), 2% chlorhexidine gluconate, quaternary ammonium, peracetic acid and formaldehyde were effective against the isolates tested. The strains showed higher resistance to vinegar (4% acetic acid), alcohol and glutaraldehyde. The findings of this study should assist in reducing the occurrence of nosocomial infections and therefore the morbidity, mortality and socio-economic burden caused by prolonged hospitalization.

  14. Occurrence and detection method evaluation of group B streptococcus from prenatal vaginal specimen in Northwest China.

    Science.gov (United States)

    Xie, Yun; Yang, JunLan; Zhao, Peng; Jia, Hui; Wang, Qi

    2016-01-01

    Sensitive and efficient detection of Group B Streptococcus (GBS) colonization in pregnant women is essential for prescription of prophylaxis at the time of delivery as GBS is an opportunistic pathogen known to cause infant mortality. In this report, two studies were conducted on the methods of GBS detection in Shaanxi province, China, a region lacking data for GBS detection and occurrence. For Study 1, 100 GBS culture-positive vaginal swabs were collected from 1,567 pregnant women for evaluation by direct latex agglutination test. In Study 2, 200 GBS vaginal swabs were evaluated by three culture methods (sheep blood agar (SBA), Columbia colistin-nalidixic agar (CNA), and selective carrot broth (SCB)) followed by analysis using a latex agglutination test. GBS was detected in 6.4 % of specimens in Study 1 and 10.5 % of specimens in Study 2. The results of the latex agglutination test in both studies were accurate with samples exhibiting high to moderate GBS growth, but the accuracy declined for samples with low GBS growth. The evaluation of culture methods for GBS detection revealed the sensitivity of SCB (95.2 %, p = 0.004) was significantly higher than that of the SBA medium (57.1 %). The sensitivity reported for SCB (95.2 %) was higher than CNA (76.0 %), but the difference was not statistically significant (p =0.078). These results indicate a selective broth, such as SCB, is ideal for accuracy at low growth levels, but a direct latex agglutination test could be used as an alternative for rapid detection of GBS in circumstances requiring immediate detection. PMID:26791082

  15. Evaluation of the PREVI® Isola automated seeder system compared to reference manual inoculation for antibiotic susceptibility testing by the disk diffusion method.

    Science.gov (United States)

    Le Page, S; van Belkum, A; Fulchiron, C; Huguet, R; Raoult, D; Rolain, J-M

    2015-09-01

    The disk diffusion (DD) method remains the most popular manual technique for antibiotic susceptibility testing (AST) in clinical microbiology laboratories. This is because of its simplicity, reproducibility, and limited cost compared to (automated) microdilution systems, which are usually less sensitive at detecting certain important mechanisms of resistance. Here, we evaluate the PREVI® Isola automated seeder system using a new protocol for spreading bacterial suspensions (eight deposits of calibrated inocula of bacteria, followed by two rounds of rotation) in comparison with manual DD reference testing on a large series of clinical and reference strains. The average time required for seeding one agar plate for DD with this new protocol was 51 s per plate, i.e., 70 agar plates/h. Reproducibility and repeatability was assessed on three reference and three randomly chosen clinical strains, as usually requested by the European Committee on Antimicrobial Susceptibility Testing (EUCAST), and was excellent compared to the manual method. The standard deviations of zones of growth inhibition showed no statistical discrimination. The correlation between the two methods, assessed using 294 clinical isolates and a panel of six antibiotics (n = 3,528 zones of growth inhibition measured), was excellent, with a correlation coefficient of 0.977. The new PREVI® Isola protocol adapted for DD had a sensitivity of 99 % and a specificity of 100 % compared to the manual technique for interpreting DD as recommended by the EUCAST. PMID:26092031

  16. Method for detection of a few pathogenic bacteria and determination of live versus dead cells

    Science.gov (United States)

    Horikawa, Shin; Chen, I.-Hsuan; Du, Songtao; Liu, Yuzhe; Wikle, Howard C.; Suh, Sang-Jin; Barbaree, James M.; Chin, Bryan A.

    2016-05-01

    This paper presents a method for detection of a few pathogenic bacteria and determination of live versus dead cells. The method combines wireless phage-coated magnetoelastic (ME) biosensors and a surface-scanning dectector, enabling real-time monitoring of the growth of specific bacteria in a nutrient broth. The ME biosensor used in this investigation is composed of a strip-shaped ME resonator upon which an engineered bacteriophage is coated to capture a pathogen of interest. E2 phage with high binding affinity for Salmonella Typhimurium was used as a model study. The specificity of E2 phage has been reported to be 1 in 105 background bacteria. The phage-coated ME biosensors were first exposed to a low-concentration Salmonella suspension to capture roughly 300 cells on the sensor surface. When the growth of Salmonella in the broth occurs, the mass of the biosensor increases, which results in a decrease in the biosensor's resonant frequency. Monitoring of this mass- induced resonant frequency change allows for real-time detection of the presence of Salmonella. Detection of a few bacteria is also possible by growing them to a sufficient number. The surface-scanning detector was used to measure resonant frequency changes of 25 biosensors sequentially in an automated manner as a function of time. This methodology offers direct, real-time detection, quantification, and viability determination of specific bacteria. The rate of the sensor's resonant frequency change was found to be largely dependent on the number of initially bound cells and the efficiency of cell growth.

  17. A fast and highly sensitive blood culture PCR method for clinical detection of Salmonella enterica serovar Typhi

    Directory of Open Access Journals (Sweden)

    Zhou Liqing

    2010-04-01

    Full Text Available Abstract Background Salmonella Typhi causes an estimated 21 million new cases of typhoid fever and 216,000 deaths every year. Blood culture is currently the gold standard for diagnosis of typhoid fever, but it is time-consuming and takes several days for isolation and identification of causative organisms. It is then too late to initiate proper antibiotic therapy. Serological tests have very low sensitivity and specificity, and no practical value in endemic areas. As early diagnosis of the disease and prompt treatment are essential for optimal management, especially in children, a rapid sensitive detection method for typhoid fever is urgently needed. Although PCR is sensitive and rapid, initial research indicated similar sensitivity to blood culture and lower specificity. We developed a fast and highly sensitive blood culture PCR method for detection of Salmonella Typhi, allowing same-day initiation of treatment after accurate diagnosis of typhoid. Methods An ox bile tryptone soy broth was optimized for blood culture, which allows the complete lysis of blood cells to release intracellular bacteria without inhibiting the growth of Salmonella Typhi. Using the optimised broth Salmonella Typhi bacteria in artificial blood samples were enriched in blood culture and then detected by a PCR targeting the fliC-d gene of Salmonella Typhi. Results Tests demonstrated that 2.4% ox bile in blood culture not only lyzes blood cells completely within 1.5 hours so that the intracellular bacteria could be released, but also has no inhibiting effect on the growth of Salmonella Typhi. Three hour enrichment of Salmonella Typhi in tryptone soya broth containing 2.4% ox bile could increase the bacterial number from 0.75 CFU per millilitre of blood which is similar to clinical typhoid samples to the level which regular PCR can detect. The whole blood culture PCR assay takes less than 8 hours to complete rather than several days for conventional blood culture

  18. A new versatile microarray-based method for high-throughput screening of carbohydrate-active enzymes

    DEFF Research Database (Denmark)

    Vidal Melgosa, Silvia; Pedersen, Henriette Lodberg; Schückel, Julia;

    2015-01-01

    Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing, together with associated bioinformatic 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...... semi-quantitative enzyme-screening technique which requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme cocktails and crude culture broths against single substrates, substrate mixtures and biomass samples. Moreover, we show...

  19. Optimization of methods for detecting norovirus on various fruit.

    Science.gov (United States)

    Kim, Hee-Yeon; Kwak, In-Shin; Hwang, In-Gyun; Ko, GwangPyo

    2008-11-01

    Methods for detecting norovirus (NoV) in food are crucial for investigation and prevention of outbreaks caused by NoV-contaminated food. However, current NoV detection methods have not been well examined or optimized. In this study, the effectiveness of various methods for eluting NoV from various fruit, concentrating the virus using polyethylene glycol (PEG), and extracting the viral RNA for subsequent assay by RT-PCR was optimized. First, six different buffers previously described for eluting NoV from fruit surfaces were evaluated. A known amount of NoV was spiked onto the surface of grapes, strawberries, and raspberries, and the virus was recovered with distilled water, 0.05 M glycine-0.14 M NaCl (pH 7.5), 2.9% tryptose phosphate broth-6% glycine, 100 mM Tris-HCl (pH 9.5), 50 mM glycine-50 mM MgCl(2) (pH 9.5), or 3% beef extract. Quantitation of the recovered virus using RT-PCR revealed that the most effective elution buffer was 3% beef extract. Secondly, to optimize a method for concentrating the recovered NoV, the key parameters of PEG precipitation, a typical method for concentrating enteric virus, were investigated. The influence of PEG molecular weight and the duration and temperature of the precipitation procedure were examined. NoV was concentrated most efficiently by precipitation when PEG (10,000) was used for 4h at room temperature. Finally, five different methods for nucleic acid extraction were evaluated. Among RNA extraction methods examined, QIAamp Viral RNA Mini kit showed the best recovery efficiency. Using the optimized method, approximately 6-80% of the seeded NoV was recovered from the various fruit.

  20. Newton's method

    Energy Technology Data Exchange (ETDEWEB)

    More, J. J.; Sorensen, D. C.

    1982-02-01

    Newton's method plays a central role in the development of numerical techniques for optimization. In fact, most of the current practical methods for optimization can be viewed as variations on Newton's method. It is therefore important to understand Newton's method as an algorithm in its own right and as a key introduction to the most recent ideas in this area. One of the aims of this expository paper is to present and analyze two main approaches to Newton's method for unconstrained minimization: the line search approach and the trust region approach. The other aim is to present some of the recent developments in the optimization field which are related to Newton's method. In particular, we explore several variations on Newton's method which are appropriate for large scale problems, and we also show how quasi-Newton methods can be derived quite naturally from Newton's method.

  1. Comparison of Results Obtained by Testing with Three Different Agar Media and by the NCCLS M27-A Method for In Vitro Testing of Fluconazole against Candida spp.

    Science.gov (United States)

    Rubio, M. Carmen; Gil, Joaquina; de Ocáriz, Inmaculada Ramírez; Benito, Rafael; Rezusta, Antonio

    2003-01-01

    Fluconazole susceptibilities of 150 Candida isolates were determined by a 25-μg fluconazole disk diffusion agar test and compared with the microdilution NCCLS M27-A method. The agar test used three different media and was read at 24 and 48 h. When only the susceptible and nonsusceptible categories were used, disk diffusion with Müeller-Hinton agar supplemented with 2% glucose and 0.5 μg of methylene blue (MHGM) per ml had a 95.37% correlation with the MIC method at 24 h, followed by RPMI 1640-2% of glucose agar (correlation, 94%) and Shadomy medium (SHDM) (correlation, 92.6%). The growth of microcolonies inside the inhibition zones was common (>63%) in the RPMI and SHDM media and minimal with MHGM (8.7%). At 48 h, MHGM and SHDM still had a >91% correlation with the MIC, while RPMI results had dropped to 75%. The best overall agreement was obtained with C. dubliniensis (100%). PMID:12791899

  2. Use of radioactive ethanolamine incorporation into phospholipids to assess in vitro antimalarial activity by the semiautomated microdilution technique.

    OpenAIRE

    Elabbadi, N; Ancelin, M.L.; Vial, H J

    1992-01-01

    Phospholipid biosynthetic activity is intense in the erythrocytic stage of Plasmodium falciparum because of the parasite's own enzymatic machinery. The incorporation of various labeled phospholipid precursors in comparison with the incorporation of nucleic acid and protein precursors was tested to evaluate P. falciparum growth in vitro. These precursors, namely, [3H]ethanolamine, [3H]hypoxanthine, [3H]palmitate, [14C]serine, [3H]choline, [3H]inositol, and [3H]isoleucine, were all accurate ind...

  3. Field Evaluation of a Semiautomated Method for Rapid and Simple Analysis of Recreational Water Microbiological Quality

    Science.gov (United States)

    Anglès d'Auriac, Marc B.; Roberts, Hildegarde; Shaw, Terri; Sirevåg, Reidun; Hermansen, Leonila Fajardo; Berg, James D.

    2000-01-01

    An early warning system using a rapid enzymatic semiautomated method suitable for fecal coliform detection in recreational waters within 8 h was developed further and evaluated in this study. This rapid method was compared to the standard method followed in the United Kingdom. We used 1,011 samples originating from 206 different locations in Wales. When we assessed the presence or absence of fecal coliforms, targeting very low levels of contamination, we obtained 83.9% agreement between the rapid method and the lauryl sulfate broth-membrane filtration technique, whereas direct confirmation of the samples processed by the rapid method showed 89.3% agreement. Environmental enzymatic background activity was found to be the main limiting factor for this method. Owing to a specific and integrated handling of the results by the software of the instrument, the percentage of false-positive results (a consequence of enzymatic background) was successfully limited to 2.9% by the direct confirmation evaluation. However, 7.8% false-negative results due to “late-growers” had to be accepted in order to produce results within a working day. At present, the method can be used in a more conservative way to assess the environmental threshold of 100 CFU of fecal coliforms per 100 ml in recreational waters. The implications of our findings with regard to the applicability of rapid enzymatic methods are discussed. PMID:11010890

  4. 寡雄腐霉发酵液的动物毒性及其对柑橘果实贮藏期青、绿霉病的防治效果%Toxicity of Pythium oligandrum broth to animal and its control effect on rot diseases caused by Penicillium italicum and Penicillium digitatum in orange fruit storage

    Institute of Scientific and Technical Information of China (English)

    谭艳; 彭良志; 袁玲; 王少博

    2015-01-01

    [目的]研制安全、无毒、高效的生物保鲜剂,降低意大利青霉(Penicillium italicum,青霉)和指状青霉(Penicillium digitatum,绿霉)引起的柑橘烂果.[方法]试验利用自主选育的寡雄腐霉优良菌株(Pythium oligandrum CQ2010),制备发酵液,测试了对小鼠的急性毒性,并设置对照(液体培养基,CK)、寡雄腐霉发酵液(P.oligandrum Broth,POB)、咪鲜胺(Prochloraz,PC)、咪鲜胺+POB(PC+POB)等4种处理,研究了它们对青、绿霉菌的抑制作用及其对柑橘防腐保鲜的作用.[结果]用大剂量的POB灌胃给药对小鼠体重增长无显著影响,供试动物的外观和行为均无异常,心、肝、肾、肺、肠等组织器官也未见病理改变.POB显著抑制青、绿霉菌丝生长和孢子萌发,抑制率分别为70.24%-93.74%(菌丝生长)和44.91%-87.82% (24 h孢子萌发).柑橘果实接种青霉后,烂果率CK> POB、PC> PC+POB,防治效果PC+POB> POB、PC.在模拟柑橘商品化贮藏保鲜试验中,青、绿霉发病率占总发病率的50%以上,CK、POB、PC和PC+POB的烂果率依次为26.40%、15.03%、16.61%和4.21%.此外,POB对果实品质无显著影响,但显著提高果皮中的超氧化物歧化酶、过氧化物酶和过氧化氢酶活性,有益于提高柑橘果实的抗病性和贮藏性.[结论]在柑橘贮藏过程中,POB对果实青、绿霉病有显著的防治作用,并与咪鲜胺的防病效果有叠加作用.

  5. Evaluation of the Antimicrobial Activity of the K9CATH Peptide (38 Amino Acids Against a Mastitis Isolated Strain of Staphylococcus aureus by the Resazurin microtiter Method

    Directory of Open Access Journals (Sweden)

    Albero Barreras-Serrano

    2014-04-01

    Full Text Available The antimicrobial activity of the synthetic peptide K9CATH was determined by the Resazurin microtitre Method (RMM against a strain of S. aureus isolated from a case of mastitis. To the antibiogram this bacteria strain showed to be resistant to Ampicillin, Erythromycin, Cefeprime, Dicloxaciline and Penicillin (10 U, while the MIC obtained for the K9CATH was 5.66 &mug/mL. Unlike the reference broth method, visual reading for MIC determination with the RMM showed to be easier, rapid, inexpensive and more sensitive for antimicrobial peptide screening, based in a color change from blue (not growth to pink (growth. This is the first time that the resazurin method is used to determine the MIC of the 38 aa´s K9CATH peptide against a mastitic isolate of S. aureus.

  6. Fermentation, fractionation and purification of streptokinase by chemical reduction method

    Directory of Open Access Journals (Sweden)

    M Niakan

    2011-05-01

    Full Text Available Background and Objectives: Streptokinase is used clinically as an intravenous thrombolytic agent for the treatment of acute myocardial infarction and is commonly prepared from cultures of Streptococcus equisimilis strain H46A. The objective of the present study was the production of streptokinase from strain H46A and purification by chemical reduction method."nMaterials and Methods: The rate of streptokinase production evaluated under the effect of changes on some fermentation factors. Moreover, due to the specific structure of streptokinase, a chemical reduction method employed for the purification of streptokinase from the fermentation broth. The H46A strain of group C streptococcus, was grown in a fermentor. The proper pH adjusted with NaOH under glucose feeding in an optimum temperature. The supernatant of the fermentation product was sterilized by filtration and concentrated by ultrafiltration. The pH of the concentrate was adjusted, cooled, and precipitated by methanol. Protein solution was reduced with dithiothreitol (DTT. Impurities settled down by aldrithiol-2 and the biological activity of supernatant containing streptokinase was determined."nResults: In the fed -batch culture, the rate of streptokinase production increased over two times as compared with the batch culture and the impurities were effectively separated from streptokinase by reduction method."nConclusion: Improvements in SK production are due to a decrease in lag phase period and increase in the growth rate of logarithmic phase. The methods of purification often result in unacceptable losses of streptokinase, but the chemical reduction method give high yield of streptokinase and is easy to perform it.

  7. New trends in dentistry: plant extracts against Enterococcus faecalis. The efficacy compared to chlorhexidine

    OpenAIRE

    Adriana Lígia de Castilho; Cintia Helena Coury Saraceni; Ingrit Elida Collantes Díaz; Mateus Luís Barradas Paciencia; Ivana Barbosa Suffredini

    2013-01-01

    Enterococcus faecalis is an important pathogen associated with endodontic diseases, and its elimination and control are of paramount importance, as it represents one of the major causes of failure in the treatment of endodontic disease. Twenty-five plant extracts obtained from Brazilian forests were found to be effective against planktonic E. faecalis and were subjected to two traditional antibacterial assays, the microdilution broth assay (MDBA) and the disk diffusion assay (DDA), using chlo...

  8. Low minimum inhibitory concentrations associated with the tetracycline-resistance gene tet(C) in Escherichia coli

    OpenAIRE

    Chalmers, Gabhan; Kozak, Gosia K.; Hillyer, Elizabeth; Reid-Smith, Richard J.; Boerlin, Patrick

    2010-01-01

    Twenty-eight Escherichia coli isolates from various animal and environmental sources with defined tetracycline-resistance genotypes for tet(A), tet(B), and tet(C) were tested for their susceptibility to tetracycline by means of both broth microdilution and Etest. All tet(C)-positive isolates had tetracycline minimum inhibitory concentrations clustering around an intermediate susceptibility range of 2 to 16 μg/mL. Detecting tet(C)-positive isolates by means of susceptibility testing may theref...

  9. In Vitro Activities of Cethromycin (ABT-773), a New Ketolide, against Streptococcus pneumoniae Strains That Are Not Susceptible to Penicillin or Macrolides

    OpenAIRE

    Mason, Edward O.; Lamberth, Linda B.; Wald, Ellen R.; Bradley, John S.; Barson, William J.; Kaplan, Sheldon L.

    2003-01-01

    Pneumococcal resistance to antimicrobials presents problems to physicians for empirical treatment of acute otitis media (AOM). Three hundred thirty-three isolates of Streptococcus pneumoniae selected for nonsusceptibility to penicillin (MIC >0.1 μg/ml) from the middle ear (n = 325) or mastoid (n = 8) of children seen between 1994 and 2000 at four children's hospitals in the United States were tested by broth microdilution for susceptibility to nine antibiotics. Using NCCLS 2002 breakpoints, r...

  10. In vitro antimicrobial susceptibility of Mycoplasma mycoides mycoides large colony and Arcanobacterium pyogenes isolated from clinical cases of ulcerative balanitis and vulvitis in Dorper sheep in South Africa

    OpenAIRE

    A. Kidanemariam; J. Gouws; M. Van Vuuren; Gummow, B.

    2005-01-01

    The in vitro activities of enrofloxacin, florfenicol, oxytetracycline and spiramycin were determined against field isolates of Mycoplasma mycoides mycoides large colony (MmmLC) by means of the broth microdilution technique. The minimum inhibitory concentrations (MICs) of these antimicrobial drugs were determined for a representative number of 10 isolates and 1 type strain. The susceptibility of Arcanobacterium pyogenes to enrofloxacin, oxytetracycline and tilmicosin was determined by means of...

  11. Ciprofloxacin-resistant methicillin-resistant Staphylococcus aureus in an acute-care hospital.

    OpenAIRE

    Raviglione, M. C.; Boyle, J. F.; Mariuz, P; Pablos-Mendez, A; Cortes, H; Merlo, A.

    1990-01-01

    Use of ciprofloxacin as an alternative to vancomycin for treatment of methicillin-resistant Staphylococcus aureus infection has been paralleled by the emergence of resistant strains. This phenomenon has also been noticed in our hospital. To confirm our observation, methicillin and ciprofloxacin susceptibilities were tested by disk diffusion and broth microdilution techniques. We studied 83 methicillin-resistant Staphylococcus aureus isolates obtained from various sources over a 4-month period...

  12. Complete genome sequences of three Pseudomonas aeruginosa isolates with phenotypes of polymyxin B adaptation and inducible resistance.

    Science.gov (United States)

    Boyle, Brian; Fernandez, Lucia; Laroche, Jerome; Kukavica-Ibrulj, Irena; Mendes, Caio M F; Hancock, Robert W; Levesque, Roger C

    2012-01-01

    Clinical "superbug" isolates of Pseudomonas aeruginosa were previously observed to be resistant to several antibiotics, including polymyxin B, and/or to have a distinct, reproducible adaptive polymyxin resistance phenotype, identified by observing "skipped" wells (appearance of extra turbid wells) during broth microdilution testing. Here we report the complete assembled draft genome sequences of three such polymyxin resistant P. aeruginosa strains (9BR, 19BR, and 213BR). PMID:22207740

  13. Complete Genome Sequences of Three Pseudomonas aeruginosa Isolates with Phenotypes of Polymyxin B Adaptation and Inducible Resistance

    OpenAIRE

    Boyle, Brian; Fernandez, Lucia; Laroche, Jerome; Kukavica-Ibrulj, Irena; Caio M. F. Mendes; Hancock, Robert W.; Levesque, Roger C.

    2012-01-01

    Clinical “superbug” isolates of Pseudomonas aeruginosa were previously observed to be resistant to several antibiotics, including polymyxin B, and/or to have a distinct, reproducible adaptive polymyxin resistance phenotype, identified by observing “skipped” wells (appearance of extra turbid wells) during broth microdilution testing. Here we report the complete assembled draft genome sequences of three such polymyxin resistant P. aeruginosa strains (9BR, 19BR, and 213BR).

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

    OpenAIRE

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

    1995-01-01

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

  15. GC and GC/MS Analysis of Essential Oil Composition of the Endemic Soqotraen Leucas virgata Balf.f. and Its Antimicrobial and Antioxidant Activities

    OpenAIRE

    Ramzi A. Mothana; Mansour S. Al-Said; Al-Yahya, Mohammed A.; Al-Rehaily, Adnan J; Jamal M. Khaled

    2013-01-01

    Leucas virgata Balf.f. (Lamiaceae) was collected from the Island Soqotra (Yemen) and its essential oil was obtained by hydrodistillation. The chemical composition of the oil was investigated by GC and GC-MS. Moreover, the essential oil was evaluated for its antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria, and one yeast species by using broth micro-dilution assay for minimum inhibitory concentrations (MIC) and antioxidant activity by measuring the scavengi...

  16. Antifungal effect of cumin essential oil alone and in combination with antifungal drugs

    OpenAIRE

    SAHADEO PATIL; PANKAJ MAKNIKAR; SUSHILKUMAR WANKHADE; CHANDRAKIRAN UKESH; MAHENDRA RA

    2015-01-01

    Abstract. Patil S, Maknikar P, Wankhade S, Ukesh C, Rai M. 2015. Antifungal effect of cumin essential oil alone and in combination with antifungal drugs. Nusantara Bioscience 7: 55-59. We report evaluation of antifungal activity of cumin seed oil and its pharmacological interactions when used in combination with some of the widely used conventional antifungal drugs using CLSI broth microdilution, agar disc diffusion and checkerboard microtitre assay against Candida. The essential oil was obta...

  17. In Vitro Antibacterial and Antibiotic Resistance Modifying Effect of Bioactive Plant Extracts on Methicillin-Resistant Staphylococcus epidermidis

    OpenAIRE

    Romana Chovanová; Mária Mikulášová; Štefánia Vaverková

    2013-01-01

    The crude extracts of plants from Asteraceae and Lamiaceae family and essential oils from Salvia officinalis and Salvia sclarea were studied for their antibacterial as well as antibiotic resistance modifying activity. Using disc diffusion and broth microdilution assays we determined higher antibacterial effect of three Salvia spp. and by evaluating the leakage of 260 nm absorbing material we detected effect of extracts and, namely, of essential oils on the disruption of cytoplasmic membrane. ...

  18. EVALUATION OF ANTIMICROBIAL AND CYTOTOXIC ACTIVITIES OF PLANT EXTRACTS FROM SOUTHERN MINAS GERAIS CERRADO

    OpenAIRE

    Juliana Moscardini Chavasco; Barbara Helena Muniz Prado E Feliphe; Claudio Daniel Cerdeira; Fabricio Damasceno Leandro; Luiz Felipe Leomil Coelho; Jeferson Junior da Silva; Jorge Kleber Chavasco; Amanda Latercia Tranches Dias

    2014-01-01

    The antimicrobial activity of plant hidroethanolic extracts on bacteria Gram positive, Gram negative, yeasts, Mycobacterium tuberculosis H37 and Mycobacterium bovis was evaluated by using the technique of Agar diffusion and microdilution in broth. Among the extracts evaluated by Agar diffusion, the extract of Bidens pilosa leaf presented the most expressive average of haloes of growth inhibition to the microorganisms, followed by the extract of B. pilosa flower, of Eugenia pyriformis' leaf an...

  19. Re-Examining the Role of Hydrogen Peroxide in Bacteriostatic and Bactericidal Activities of Honey

    OpenAIRE

    Brudzynski, Katrina; Abubaker, Kamal; St-Martin, Laurent; Castle, Alan

    2011-01-01

    The aim of this study was to critically analyze the effects of hydrogen peroxide on growth and survival of bacterial cells in order to prove or disprove its purported role as a main component responsible for the antibacterial activity of honey. Using the sensitive peroxide/peroxidase assay, broth microdilution assay and DNA degradation assays, the quantitative relationships between the content of H2O2 and honey’s antibacterial activity was established. The results showed that: (A) the average...

  20. QUANTIFICATION OF LISTERIA MONOCYTOGENES IN MILK BY MPN-PCR AND MPN-CULTURE METHODS

    Directory of Open Access Journals (Sweden)

    Mahzad Hosseini

    2014-10-01

    Full Text Available The aim of this study was to compare the MPN-PCR (Most Probable Number- Polymerase Chain Reaction and MPN-Culture methods in enumerating of Listeria monocytogenes in milk. In order to compare the accuracy of these methods, 103 cell/ml Listeria monocytogenes and different background bacteria which may be present in raw milk, were inoculated in sterilized milk. After preparing serial dilutions, three replicates per dilution were inoculated in tubes containing listeria enrichment broth. After 48 hours of incubation, for MPN-Culture three inoculated replicates were subcultured on Oxford agar and suspected colonies were confirmed by performing by biochemical tests. For MPN-PCR assay, the DNA extraction was performed from the three inoculated replicates which were already used for MPN-Culture and PCR assay was performed using primers specific for Listeria monocytogenes. The experiment was repeated three times and the average of enumerated bacteria was calculated by each method separately. Statistical analysis using one sample Wilcoxon signed rank test showed that enumeration by MPN-PCR method was more accurate than enumeration by MPN-Culture method. The result of this study showed that MPN-PCR method in comparision with MPN-Culture even in the presence of different background microorganisms is more rapid and reliable. It is concluded that MPN-PCR method facilitates the enumeration of Listeria monocytogenes without excessive work and could be considered as an alternative to MPN-Culture technique.

  1. Mining Method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Shik; Lee, Kyung Woon; Kim, Oak Hwan; Kim, Dae Kyung [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1996-12-01

    The reducing coal market has been enforcing the coal industry to make exceptional rationalization and restructuring efforts since the end of the eighties. To the competition from crude oil and natural gas has been added the growing pressure from rising wages and rising production cost as the workings get deeper. To improve the competitive position of the coal mines against oil and gas through cost reduction, studies to improve mining system have been carried out. To find fields requiring improvements most, the technologies using in Tae Bak Colliery which was selected one of long running mines were investigated and analyzed. The mining method appeared the field needing improvements most to reduce the production cost. The present method, so-called inseam roadway caving method presently is using to extract the steep and thick seam. However, this method has several drawbacks. To solve the problems, two mining methods are suggested for a long term and short term method respectively. Inseam roadway caving method with long-hole blasting method is a variety of the present inseam roadway caving method modified by replacing timber sets with steel arch sets and the shovel loaders with chain conveyors. And long hole blasting is introduced to promote caving. And pillar caving method with chock supports method uses chock supports setting in the cross-cut from the hanging wall to the footwall. Two single chain conveyors are needed. One is installed in front of chock supports to clear coal from the cutting face. The other is installed behind the supports to transport caved coal from behind. This method is superior to the previous one in terms of safety from water-inrushes, production rate and productivity. The only drawback is that it needs more investment. (author). 14 tabs., 34 figs.

  2. Discipline methods

    OpenAIRE

    Maria Kikila; Ioannis Koutelekos

    2012-01-01

    Child discipline is one of the most important elements of successful parenting. As discipline is defined the process that help children to learn appropriate behaviors and make good choices. Aim: The aim of the present study was to review the literature about the discipline methods. The method οf this study included bibliography research from both the review and the research literature, mainly in the pubmed data base which referred to the discipline methods. Results: In the literature it is ci...

  3. Projection Methods

    DEFF Research Database (Denmark)

    Wagner, Falko Jens; Poulsen, Mikael Zebbelin

    1999-01-01

    When trying to solve a DAE problem of high index with more traditional methods, it often causes instability in some of the variables, and finally leads to breakdown of convergence and integration of the solution. This is nicely shown in [ESF98, p. 152 ff.].This chapter will introduce projection...... methods as a way of handling these special problems. It is assumed that we have methods for solving normal ODE systems and index-1 systems....

  4. Computing methods

    CERN Document Server

    Berezin, I S

    1965-01-01

    Computing Methods, Volume 2 is a five-chapter text that presents the numerical methods of solving sets of several mathematical equations. This volume includes computation sets of linear algebraic equations, high degree equations and transcendental equations, numerical methods of finding eigenvalues, and approximate methods of solving ordinary differential equations, partial differential equations and integral equations.The book is intended as a text-book for students in mechanical mathematical and physics-mathematical faculties specializing in computer mathematics and persons interested in the

  5. Maintenance methods

    International Nuclear Information System (INIS)

    The maintenance method applied at the Hague is summarized. The method was developed in order to solve problems relating to: the different specialist fields, the need for homogeneity in the maintenance work, the equipment diversity, the increase of the materials used at the Hague's new facilities. The aim of the method is to create a knowhow formalism, to facilitate maintenance, to ensure the running of the operations and to improve the estimation of the maintenance cost. One of the method's difficulties is the demonstration of the profitability of the maintenance operations

  6. Studies on bactericidal efficacy of pumpkin (Cucurbita moschata Duchesne peel

    Directory of Open Access Journals (Sweden)

    El Zawane Kamarudin

    2014-02-01

    Full Text Available Objective: T o explore the in vitro antibacterial potential of the peel of Cucurbita moschata D uchesne ( tropical pumpkin ( C. moschata against human pathogenic bacteria. Methods: I n the present study, dichloromethane ( DCM , methanol ( MEOH and aqueous extracts of C. moschata peel were examined for in vitro antibacterial potency against eight bacterial strains i.e. Bacillus cereus, Burkholderia cepacia, Escherichia coli, Enterococcus faecalis, Staphyloccocus aureus, Pseudomonas aerugenosa, Vibrio alginolyticus, Vibrio parahaemolyticus using K irby- B auer disk diffusion susceptibility and broth micro-dilution methods. Results: DCM extract of pumpkin peel exhibited the maximum zone of inhibition against Staphyloccocus aureus ( 21 mm whereas aqueous extract of pumpkin peel revealed the least zone of inhibition against Escherichia coli ( 8 mm . MEOH extract gave maximum zone of inhibition against Pseudomonas aerugenosa ( 19 mm . B roth micro-dilution method showed minimum inhibitory concentration for the DCM extract against Burkholderia cepacia at 6 . 25 mg/m L . T he minimum bactericidal concentrations were also determined to know the nature of all extracts. DCM and MEOH extracts exhibited bactericidal nature to all bacterial strains except for the Vibrio alginolyticus. T he minimum bactericidal concentrations values exhibited bactericidal nature ranging from 3 . 12 mg/m L to 100 . 00 mg/m L . T he screening of antimicrobial properties of different extracts of C. moschata peel revealed that the DCM extract possessed good antimicrobial efficacy compared to MEOH and aqueous extracts. Conclusions: P eel of C. moschata possesses antibacterial compounds and could be potential source for a new class of antibiotics.

  7. Screening Togolese medicinal plants for few pharmacological properties

    Directory of Open Access Journals (Sweden)

    Simplice D Karou

    2012-01-01

    Full Text Available Background: Terminalia macroptera Guill. et Perr. (Combretaceae, Sida alba L. (Malvaceae, Prosopis africana Guill et Perr. Taub. (Mimosaceae, Bridelia ferruginea Benth. (Euphorbiaceae, and Vetiveria nigritana Stapf. (Asteraceae are traditionally used in Togolese folk medicine to treat several diseases including microbial infections. Objective: This study aimed to investigate the antimicrobial, antioxidant, and hemolytic properties of the crude extracts of the above-mentioned plants. Materials and Methods: The antimicrobial and the antioxidant activities were assayed using the NCCLS microdilution method and the DPPH free radical scavenging, respectively. Human A+ red blood cells were used to perform the hemolytic assay. Phenolics were further quantified in the extracts using spectrophotometric methods. Results: Minimal inhibitory concentrations in the range of 230-1800 μg/ml were recorded in the NCCLS broth microdilution for both bacterial and fungal strains with methanol extracts. The DPPH radical scavenging assay yielded interesting antioxidant activities of the extracts of P. africana and T. macroptera (IC 50 values of 0.003 ± 0.00 μg/ml and 0.05 ± 0.03 μg/ml, respectively. These activities were positively correlated with the total phenolic contents and negatively correlated with the proanthocyanidin content of the extracts. The hemolytic assay revealed that great hemolysis occurred with the methanol extracts of T. macroptera, S. longepedunculata, and B. ferruginea. Conclusion: These results support in part the use of the selected plants in the treatment of microbial infections. In addition, the plant showed an interesting antioxidant activity that could be useful in the management of oxidative stress.

  8. Antimicrobial activity of linezolid combined with minocycline against vancomycin-resistant Enterococci

    Institute of Scientific and Technical Information of China (English)

    WU Jing; JIANG Tian-tong; SU Jian-rong; LI Li

    2013-01-01

    Background Vancomycin-resistant Enterococci (VRE) cause serious infections that are difficult to treat.We carried out this study to determine the mutant prevention concentration (MPC) of linezolid when combined with minocycline against VRE strains,to determine the mechanism of drug resistance in vitro,and to provide a theoretical basis for the rational use of drugs against VRE.Methods The minimum inhibitory concentrations (MICs) of linezolid and minocycline against 30 Enterococci (E.) isolates (including 20 VRE strains) were determined by the broth microdilution method.Drug interactions were assessed by the checkerboard microdilution tests and confirmed by time-kill studies.Two vancomycin-susceptible strains N27 and N40 (linezolid MIC,2 g/ml; minocycline MIC,4 μg/ml) and control strains E.faecalis ATCC 29212 and ATCC 51299 were also tested.The MPCs of linezolid and minocycline (alone and combined) were determined using the agar dilution method.Strains showing stable resistance were analyzed by polymerase chain reaction (PCR) amplification of domain V of the 23S rRNA gene.Results Checkerboard titration studies revealed synergistic effects of combination therapy in 26.7% of 30 E.isolates.Antagonism was not observed.The G2576U mutation was detected in stable linezolid-resistant strains of ATCC 29212,N40,and N27 before and after resistance screening,and MIC values increased with the number of G2576U mutations.The MPC of linezolid against E.decreased dramatically when combined with minocycline,and vice versa.Conclusion Linezolid or minocycline alone produce resistant strains; however,their joint use may reduce the MPC of each agent against VRE,thereby decreasing resistant mutants and bacterial infections.

  9. Method 59

    DEFF Research Database (Denmark)

    Kjellsson, G.

    1994-01-01

    OCDE/GD(94)41. Er supplerende rapport til rapport: The OECD Workshop on Methods for Monitoring Organisms in the Environment, Ottawa 14-17 September 1992. Environment Monograph 90.......OCDE/GD(94)41. Er supplerende rapport til rapport: The OECD Workshop on Methods for Monitoring Organisms in the Environment, Ottawa 14-17 September 1992. Environment Monograph 90....

  10. Methods to identify the unexplored diversity of microbial exopolysaccharides

    Directory of Open Access Journals (Sweden)

    Broder eRühmann

    2015-06-01

    Full Text Available Microbial exopolysaccharides (EPS are a structurally very diverse class of molecules. A number of them have found their application in rather diverging fields that extend from medicine, food and cosmetics on the one side to construction, drilling and chemical industry on the other side. The analysis of microbial strains for their competence in polysaccharide production has therefore been a major issue in the past, especially in the search for new polysaccharide variants among natural strain isolates. Concerning the fact that nearly all microbes carry the genetic equipment for the production of polysaccharides under specific conditions, the naturally provided EPS portfolio seems to be still massively underexplored. Therefore, there is a need for high throughput screening techniques capable of identifying novel variants of bacterial exopolysaccharides with properties superior to the already described ones, or even totally new ones. A great variety of different techniques has been used in screening approaches for identifying microorganisms that are producing EPS in substantial amounts. Mucoid growth is often the method of choice for visual identification of EPS producing strains. Depending on the thickening characteristics of the polysaccharide, observation of viscosity in culture broth can also be an option to evaluate EPS production. Precipitation with different alcohols represents a common detection, isolation and purification method for many EPS. A more quantitative approach is found in the total carbohydrate content analysis, normally determined e.g. by phenol-sulfuric-acid-method. In addition, recently a new and reliable method for the detailed analysis of the monomeric composition and the presence of rare sugars and sugar substitutions has become available, which could give a first hint of the polymer structure of unknown EPS. This minireview will compare available methods and novel techniques and discuss their benefits and disadvantages.

  11. Methods to identify the unexplored diversity of microbial exopolysaccharides.

    Science.gov (United States)

    Rühmann, Broder; Schmid, Jochen; Sieber, Volker

    2015-01-01

    Microbial exopolysaccharides (EPS) are a structurally very diverse class of molecules. A number of them have found their application in rather diverging fields that extend from medicine, food, and cosmetics on the one side to construction, drilling, and chemical industry on the other side. The analysis of microbial strains for their competence in polysaccharide production has therefore been a major issue in the past, especially in the search for new polysaccharide variants among natural strain isolates. Concerning the fact that nearly all microbes carry the genetic equipment for the production of polysaccharides under specific conditions, the naturally provided EPS portfolio seems to be still massively underexplored. Therefore, there is a need for high throughput screening techniques capable of identifying novel variants of bacterial EPS with properties superior to the already described ones, or even totally new ones. A great variety of different techniques has been used in screening approaches for identifying microorganisms that are producing EPS in substantial amounts. Mucoid growth is often the method of choice for visual identification of EPS producing strains. Depending on the thickening characteristics of the polysaccharide, observation of viscosity in culture broth can also be an option to evaluate EPS production. Precipitation with different alcohols represents a common detection, isolation, and purification method for many EPS. A more quantitative approach is found in the total carbohydrate content analysis, normally determined, e.g., by phenol-sulfuric-acid-method. In addition, recently a new and reliable method for the detailed analysis of the monomeric composition and the presence of rare sugars and sugar substitutions has become available, which could give a first hint of the polymer structure of unknown EPS. This minireview will compare available methods and novel techniques and discuss their benefits and disadvantages.

  12. Comparison of Six Culture Methods for Salmonella Isolation from Poultry Fecal Samples

    Directory of Open Access Journals (Sweden)

    Morshed, R. (PhD

    2014-06-01

    Full Text Available Background and Objective: Salmonellosis is one of the most important food-borne bacterial zoonotic diseases worldwide, and poultry and its products are the major sources for salmonella transmission to human. Isolation of Salmonella enterica from poultry needs bacteriologic enrichment and selected cultures of fecal samples. In this study, different culture methods for the isolation of salmonella from fecal samples were compared. Material and Methods: Forty- five positive samples from infected farms and 45 negative samples from normal farms were processed using enrichment media including tetrathionate broth, selenite cistine and Rappaport-Vassiliadis. Then the samples were incubated in selective cultures, and after 24 h, their results were compared with standard method. Results: Specificity of all methods for salmonella isolation was 100%, and salmonella was not isolated from the negative samples. The highest susceptibility was related to the method in which the sample first in Selenite cistine and later in Rappaport-Vassiliadis was enriched (100%. Enrichment in Rappaport-Vassiliadis could isolate 41 salmonella from 45 positive samples (91% while the result of enrichment in tetrathionate was 6 isolates (13.3%. Conclusion: This study shows that enrichment in selenite cistine and then in Rappaport-Vassiliadis is currently the best method for isolating salmonella from fecal samples of poultry. Key words: Salmonella; Bacteriologic Culture; Diagnosis; Isolation; Enrichment; Poultry

  13. In-house validation study for salmonella unique testing of juice (modification of AOAC official method 2000.07).

    Science.gov (United States)

    Dailianis, Angela E; Hughes, Denise

    2002-01-01

    Following an industry request, a study was undertaken to validate a minor change to the Unique method for testing fruit juice. Twenty foods were tested in the original precollaborative study for TECRA Unique Salmonella test (2000.07). To validate the modification for juice, both the modified method (42 degrees C module incubation with a 5 h replication step) and the current AOAC Method 2000.07 (37 degrees C incubation with a 4 h replication step) were compared with the U.S. Food and Drug Administration's Bacteriological Analytical Manual (BAM; 8th Ed., 1998) reference method, which uses lactose broth as pre-enrichment medium. Twenty uninoculated replicates, 20 replicates with low-level inoculum (target 1-5 cells/25 g), and 20 replicates with high-level inoculum (target 10-50 cells/25 g) were tested for a single batch of fresh orange juice in accordance with AOAC requirements. There was exact agreement between the 2 Unique methods for all samples and exact agreement between the 2 Unique methods and the BAM method for the uninoculated and high-level inoculum samples. For low-level inoculum, 17 samples were confirmed positive with the new Unique method, 17 with AOAC Method 2000.07, and 14 with the BAM method. PMID:12477197

  14. Method Mixins

    DEFF Research Database (Denmark)

    Ernst, Erik

    2005-01-01

    The world of programming has been conquered by the procedure call mechanism, including object-oriented method invocation which is a procedure call in context of an object. This paper presents an alternative, method mixin invocations, that is optimized for flexible creation of composite behavior......, where traditional invocation is optimized for as-is reuse of existing behavior. Tight coupling reduces flexibility, and traditional invocation tightly couples transfer of information and transfer of control. Method mixins decouple these two kinds of transfer, thereby opening the doors for new kinds...... of abstraction and reuse. Method mixins use shared name spaces to transfer information between caller and callee, as opposed to traditional invocation which uses parameters and returned results. This relieves the caller from dependencies on the callee, and it allows direct transfer of information further down...

  15. Method Mixins

    DEFF Research Database (Denmark)

    Ernst, Erik

    2002-01-01

    The procedure call mechanism has conquered the world of programming, with object-oriented method invocation being a procedure call in context of an object. This paper presents an alternative, method mixin invocations, that is optimized for flexible creation of composite behavior, where traditional...... invocation is optimized for as-is reuse of existing behavior. Tight coupling reduces flexibility, and traditional invocation tightly couples transfer of information and transfer of control. Method mixins decouple these two kinds of transfer, thereby opening the doors for new kinds of abstraction and reuse....... Method mixins use shared name spaces to transfer information between caller and callee, as opposed to traditional invocation which uses parameters and returned results. This relieves a caller from dependencies on the callee, and it allows direct transfer of information further down the call stack, e...

  16. Dosimetry methods

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Miller, A.; Kovacs, A.;

    2003-01-01

    Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application.......Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application....

  17. 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

    . 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......, a faster, real-time PCR approach was validated in comparative and collaborative trials, based on recommendations from the Nordic system for validation of alternative microbiological methods (NordVal). The comparative real-time PCR trial was performed in comparison to two reference culture protocols...... 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...

  18. High-throughput screening method for lipases/esterases.

    Science.gov (United States)

    Mateos-Díaz, Eduardo; Rodríguez, Jorge Alberto; de Los Ángeles Camacho-Ruiz, María; Mateos-Díaz, Juan Carlos

    2012-01-01

    High-throughput screening (HTS) methods for lipases and esterases are generally performed by using synthetic chromogenic substrates (e.g., p-nitrophenyl, resorufin, and umbelliferyl esters) which may be misleading since they are not their natural substrates (e.g., partially or insoluble triglycerides). In previous works, we have shown that soluble nonchromogenic substrates and p-nitrophenol (as a pH indicator) can be used to quantify the hydrolysis and estimate the substrate selectivity of lipases and esterases from several sources. However, in order to implement a spectrophotometric HTS method using partially or insoluble triglycerides, it is necessary to find particular conditions which allow a quantitative detection of the enzymatic activity. In this work, we used Triton X-100, CHAPS, and N-lauroyl sarcosine as emulsifiers, β-cyclodextrin as a fatty acid captor, and two substrate concentrations, 1 mM of tributyrin (TC4) and 5 mM of trioctanoin (TC8), to improve the test conditions. To demonstrate the utility of this method, we screened 12 enzymes (commercial preparations and culture broth extracts) for the hydrolysis of TC4 and TC8, which are both classical substrates for lipases and esterases (for esterases, only TC4 may be hydrolyzed). Subsequent pH-stat experiments were performed to confirm the preference of substrate hydrolysis with the hydrolases tested. We have shown that this method is very useful for screening a high number of lipases (hydrolysis of TC4 and TC8) or esterases (only hydrolysis of TC4) from wild isolates or variants generated by directed evolution using nonchromogenic triglycerides directly in the test.

  19. A Study on the Antibacterial Activity Of Zno Nanoparticles Prepared By Combustion Method against E Coli

    Directory of Open Access Journals (Sweden)

    Durga Prasad

    2014-06-01

    Full Text Available Crystalline Zinc Oxide (ZnO nanoparticles were synthesized by low temperature solution combustion method using Oxalyl dihydrazide (ODH as fuel, at much lower temperature (300oC. X-ray diffraction (XRD confirmed the formation of wurtzite-structured pure ZnO No peaks from any else phases of ZnO and no impurity peaks were observed, indicating the high purity of the obtained hexagonal ZnO nanocrystals. The antibacterial activity of the formed nano ZnO were investigated against the pathogenic bacteria namely against E-coli. The bacteriological test is performed in Luria-Bertani and Nutrient agar media on solid agar plates and liquid broth system using different concentration of ZnO by standard microbial method. We have used both colony counting method and disk diffusion method. In both the methods ZnO nanoparticles with 100microg/L showed best antibacterial activity, and further studies on destruction of bacterial genomic DNA was done using PCR and gel electrophoresis revealed the DNA fragment bands, this activity might be due to surface charge interactions between the particles and cells. Free radical scavenging properties of the particles might have helped in cell wall disruption, and drastic antimicrobial action.

  20. Ensemble Methods

    Science.gov (United States)

    Re, Matteo; Valentini, Giorgio

    2012-03-01

    Ensemble methods are statistical and computational learning procedures reminiscent of the human social learning behavior of seeking several opinions before making any crucial decision. The idea of combining the opinions of different "experts" to obtain an overall “ensemble” decision is rooted in our culture at least from the classical age of ancient Greece, and it has been formalized during the Enlightenment with the Condorcet Jury Theorem[45]), which proved that the judgment of a committee is superior to those of individuals, provided the individuals have reasonable competence. Ensembles are sets of learning machines that combine in some way their decisions, or their learning algorithms, or different views of data, or other specific characteristics to obtain more reliable and more accurate predictions in supervised and unsupervised learning problems [48,116]. A simple example is represented by the majority vote ensemble, by which the decisions of different learning machines are combined, and the class that receives the majority of “votes” (i.e., the class predicted by the majority of the learning machines) is the class predicted by the overall ensemble [158]. In the literature, a plethora of terms other than ensembles has been used, such as fusion, combination, aggregation, and committee, to indicate sets of learning machines that work together to solve a machine learning problem [19,40,56,66,99,108,123], but in this chapter we maintain the term ensemble in its widest meaning, in order to include the whole range of combination methods. Nowadays, ensemble methods represent one of the main current research lines in machine learning [48,116], and the interest of the research community on ensemble methods is witnessed by conferences and workshops specifically devoted to ensembles, first of all the multiple classifier systems (MCS) conference organized by Roli, Kittler, Windeatt, and other researchers of this area [14,62,85,149,173]. Several theories have been

  1. Discipline methods

    Directory of Open Access Journals (Sweden)

    Maria Kikila

    2012-01-01

    Full Text Available Child discipline is one of the most important elements of successful parenting. As discipline is defined the process that help children to learn appropriate behaviors and make good choices. Aim: The aim of the present study was to review the literature about the discipline methods. The method οf this study included bibliography research from both the review and the research literature, mainly in the pubmed data base which referred to the discipline methods. Results: In the literature it is cited that discipline is not the same as punishment because is more related to teaching. The ultimate goal of effective punishment is to help the child in exercising self-control, accountability and respect. Children raised without proper discipline, are at risk for a variety of behavioral and emotional problems. Over the last decades, many child discipline techniques have been suggested that vary according to the age of the child, the parenting style and the severity of the behavior. The most effective methods are giving rewards and guidance to make good choices, explaining negative consequences for disobedience without issuing threats, teaching of moral behaviors by displaying parents' good and moral behaviors. Another commonly accepted discipline method is "the consequences' which permits children to have the dignity of dealing with results of their behavior. Conclusions: Discipline consists a tool for parents for the reason that it trains children to think their improper behavior and the following consequences as well as the possible solutions to each problem.

  2. Statistical methods

    CERN Document Server

    Freund, Rudolf J; Wilson, William J

    2010-01-01

    Statistical Methods, 3e provides students with a working introduction to statistical methods offering a wide range of applications that emphasize the quantitative skills useful across many academic disciplines. This text takes a classic approach emphasizing concepts and techniques for working out problems and intepreting results. The book includes research projects, real-world case studies, numerous examples and data exercises organized by level of difficulty. This text requires that a student be familiar with algebra. New to this edition: NEW expansion of exercises a

  3. Spectral Methods

    CERN Document Server

    Shen, Jie; Wang, Li-Lian

    2011-01-01

    Along with finite differences and finite elements, spectral methods are one of the three main methodologies for solving partial differential equations on computers. This book provides a detailed presentation of basic spectral algorithms, as well as a systematical presentation of basic convergence theory and error analysis for spectral methods. Readers of this book will be exposed to a unified framework for designing and analyzing spectral algorithms for a variety of problems, including in particular high-order differential equations and problems in unbounded domains. The book contains a large

  4. Statistical methods

    CERN Document Server

    Szulc, Stefan

    1965-01-01

    Statistical Methods provides a discussion of the principles of the organization and technique of research, with emphasis on its application to the problems in social statistics. This book discusses branch statistics, which aims to develop practical ways of collecting and processing numerical data and to adapt general statistical methods to the objectives in a given field.Organized into five parts encompassing 22 chapters, this book begins with an overview of how to organize the collection of such information on individual units, primarily as accomplished by government agencies. This text then

  5. Digital Methods

    NARCIS (Netherlands)

    R. Rogers

    2013-01-01

    In Digital Methods, Richard Rogers proposes a methodological outlook for social and cultural scholarly research on the Web that seeks to move Internet research beyond the study of online culture. It is not a toolkit for Internet research, or operating instructions for a software package; it deals wi

  6. Radiofluorination method

    DEFF Research Database (Denmark)

    2014-01-01

    A method of conducting radiofluorination of a substrate, comprising the steps of: (a) contacting an aqueous solution of [18F] fluoride with a polymer supported phosphazene base for sufficient time for trapping of [18F] fluoride on the polymer supported phosphazene base; and (b) contacting...

  7. Characterization methods

    Energy Technology Data Exchange (ETDEWEB)

    Glass, J.T. [North Carolina State Univ., Raleigh (United States)

    1993-01-01

    Methods discussed in this compilation of notes and diagrams are Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, and other surface analysis techniques (auger electron spectroscopy, x-ray photoelectron spectroscopy, electron energy loss spectroscopy, and scanning tunnelling microscopy). A comparative evaluation of different techniques is performed. In-vacuo and in-situ analyses are described.

  8. Prevalence of ESBL phenotype,blaCTX-M-1,blaSHV andblaTEM genes among uropathogenicEscherichia coli isolates from 3 military hospitals of Tehran, Iran

    Institute of Scientific and Technical Information of China (English)

    Farshad Nojoomi; Abdolmajid Ghasemian

    2016-01-01

    Objective:To determine the extended-spectrum beta-lactamase (ESBL) production and prevalence ofblaCTX-M-1,blaSHV andblaTEM genes among uropathogenic Escherichia coli(UPEC) isolates from 3 military hospitals of Tehran during 2015–2016. Methods: One-hundred and eleven isolates were adopted. The antibiotic susceptibility testing was conducted according to Clinical and Laboratory Standards Institute guidelines. The combine disk was used for phenotypicESBL production. The ceftazidimeMIC was conducted with the micro-broth dilution test. ThePCR assay was used to detect theblaCTX-M-1,blaSHV and blaTEM genes. Results:In the broth microdilution method, 103 (92.7%) isolates showed minimal inhibitory concentration (MIC)≥1µg/mL, and also in the combined disk method, 89 (80.1% of all) wereESBL positive. On the other hand, among 91 ceftazidime resistant isolates, 86 (77.4% of all) wereESBLpositive. The difference between the two methods forESBL confirmation was not significant. The result ofMIC was similar to the disk diffusion method in the detection of phenotypicESBL production. AmongESBLproducer isolates, the prevalence ofblaCTX-M-1, blaSHV andblaTEM was 77.4% (n= 86), 47.4% (n= 53) and 2.4% (n= 2), respectively. These genes were amplified in a wide rangeMIC of ceftazidime. Conclusions:The prevalence of multi-drug resistantUPEC andESBL positive isolates was high in military hospitals. The majority ofUPEC isolates amplifiedblaCTX-M-I andblaSHV typeβ-lactamase genes. One-third of isolates were positive in presence of both these genes. There was no relation between ceftazidimeMIC and presence of beta-lactamase genes.

  9. Comparison of eight methods for the extraction of Bacillus atrophaeus spore DNA from eleven common interferents and a common swab.

    Directory of Open Access Journals (Sweden)

    Helen L Rose

    Full Text Available Eight DNA extraction products or methods (Applied Biosystems PrepFiler Forensic DNA Extraction Kit; Bio-Rad Instagene Only, Bio-Rad Instagene & Spin Column Purification; EpiCentre MasterPure DNA & RNA Kit; FujiFilm QuickGene Mini80; Idaho Technologies 1-2-3 Q-Flow Kit; MoBio UltraClean Microbial DNA Isolation Kit; Sigma Extract-N-Amp Plant and Seed Kit were adapted to facilitate extraction of DNA under BSL3 containment conditions. DNA was extracted from 12 common interferents or sample types, spiked with spores of Bacillus atropheaus. Resulting extracts were tested by real-time PCR. No one method was the best, in terms of DNA extraction, across all sample types. Statistical analysis indicated that the PrepFiler method was the best method from six dry powders (baking, biological washing, milk, plain flour, filler and talcum and one solid (Underarm deodorant, the UltraClean method was the best from four liquids (aftershave, cola, nutrient broth, vinegar, and the MasterPure method was the best from the swab sample type. The best overall method, in terms of DNA extraction, across all sample types evaluated was the UltraClean method.

  10. Numerical methods

    CERN Document Server

    Dahlquist, Germund

    2003-01-01

    ""Substantial, detailed and rigorous . . . readers for whom the book is intended are admirably served."" - MathSciNet (Mathematical Reviews on the Web), American Mathematical Society.Practical text strikes fine balance between students' requirements for theoretical treatment and needs of practitioners, with best methods for large- and small-scale computing. Prerequisites are minimal (calculus, linear algebra, and preferably some acquaintance with computer programming). Text includes many worked examples, problems, and an extensive bibliography.

  11. Critical assessment of suitable methods used for determination of antibacterial properties at photocatalytic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Krysa, Josef, E-mail: Josef.Krysa@vscht.cz [Institute of Chemical Technology Prague, Department of Water Technology and Environmental Engineering, Technicka 5, CZ-166 28 Prague (Czech Republic); Musilova, Eva [Institute of Chemical Technology Prague, Department of Water Technology and Environmental Engineering, Technicka 5, CZ-166 28 Prague (Czech Republic); Zita, Jiri [Institute of Chemical Technology Prague, Department of Inorganic Technology, Technicka 5, CZ-166 28 Prague (Czech Republic)

    2011-11-15

    Highlights: {yields} Methods for antibacterial activity of irradiated TiO{sub 2} films were critically assessed. {yields} As test bacteria gram negative E. coli and gram positive E. faecalis were employed. {yields} The ISO glass adhesion method is more appropriate than method with bacteria suspension. {yields} Some improvements of the ISO method were suggested. - Abstract: This work describes the development of methods necessary for antibacterial effect evaluation on irradiated TiO{sub 2} layers. Two methods using bacteria suspensions and the glass adhesion method (based on ISO 27447:2009(E)) were critically assessed and compared. As test bacteria gram negative Escherichia coli and gram positive Enterococcus faecalis were employed. The method using 50 cm{sup 3} of bacteria suspension is convenient for testing layers with strong antibacterial effect (prepared from powder photocatalysts). For the evaluation of the antibacterial effect of sol gel layers, the glass adhesion method based on the ISO is more appropriate than the method with 3 cm{sup 3} of bacteria suspension. The reason is that the later does not allow a distinction between the inhibition effect of TiO{sub 2} and UV light itself. Some improvements of the ISO method were suggested, namely the use of gelatinous pills (CCM) of bacteria, using saline solution instead of nutrient broth for bacteria suspension preparation and the application of selective media for bacteria cultivation. Decreasing the light intensity from 0.6 mW cm{sup -2} to 0.2 mW cm{sup -2} (fulfilling the requirements of the ISO) results in almost negligible effect of UV light itself, thus enabling proper testing of the antibacterial properties of TiO{sub 2} thin films.

  12. Protein expression on Cr resistant microorganism using electrophoresis method

    Directory of Open Access Journals (Sweden)

    SAJIDAN

    2009-01-01

    Full Text Available Fatmawati U, Suranto, Sajidan. 2009. Protein expression on Cr resistant microorganism using electrophoresis method. Nusantara Bioscience 1: 31-37. Hexavalent chromium (Cr(VI is known as toxic heavy metals, so the need is reduced to Cr(III is much less toxicity. Pseudomonas aeruginosa, Pseudomonas putida, Klebsiella pneumoniae, Pantoea sp. and Saccharomyces cerevisiae are resistant Cr(VI microorganism and have ability to reduce Cr(VI. The aim of this research is to know ability of microorganism to reduce Cr(VI and to know protein band pattern between Cr(VI resistant microorganism and non resistant microorganism which inoculated on LB broth. SDS-PAGE was used to indentify protein expression. While, Cr(VI concentration was identified by 1.5 diphenylcarbazide method. The quantitative data was analyzed by two factorial ANOVA that continued with DMRT at 1% level test. The qualitative data i.e. protein expression analyzed by relative mobility (Rf. The results showed that the ability of microorganisms to reduce Cr(VI at initial concentration of 0.5 ppm, 1 ppm, 5 ppm and 10 ppm may vary, the average percentage of the ability of each microorganism in reducing Cr(VI is P. putida (65% > S. cerevisiae (64.45% >. P. aeruginosa (60.73% > Pantoea sp. (50.22% > K. pneumoniae (47.82% > without microorganisms (34.25%. The adding microorganisms have significantly influenced toward reduction of Cr(VI. The SDS-PAGE shows that protein expression between resistant and not resistant microorganisms are no different, but resistant microorganisms have more protein (protein band is thicker.

  13. Solidification method

    International Nuclear Information System (INIS)

    Purpose: To subject the condensate of steam discharged from the turbine of a BWR type power plant to ion-exchange processing, and thereafter to render sodium sulfate containing radioactive liquid wastes produced when the ion-exchange resin thus obtained are reproduced into asphalt solidified bodies stable even in water. Method: In the above described liquid wastes, there is added a water-soluble calcium compound such as calcium nitrate or the like. In this case, when the quantity of the water-soluble calcium compound added is 7 to 8% with respect to sulfuric acid ions on the basis of the weight of calcium ions, swelling and porosity of solidified bodies can be prevented. (Kamimura, M.)

  14. WELDING METHOD

    Science.gov (United States)

    Cornell, A.A.; Dunbar, J.V.; Ruffner, J.H.

    1959-09-29

    A semi-automatic method is described for the weld joining of pipes and fittings which utilizes the inert gasshielded consumable electrode electric arc welding technique, comprising laying down the root pass at a first peripheral velocity and thereafter laying down the filler passes over the root pass necessary to complete the weld by revolving the pipes and fittings at a second peripheral velocity different from the first peripheral velocity, maintaining the welding head in a fixed position as to the specific direction of revolution, while the longitudinal axis of the welding head is disposed angularly in the direction of revolution at amounts between twenty minutas and about four degrees from the first position.

  15. Antimicrobial constituents of the leaves of Mikania micrantha H. B. K.

    Directory of Open Access Journals (Sweden)

    Yan Li

    Full Text Available BACKGROUND: To isolate plant-derived compounds with antimicrobial activity from the leaves of Mikania micrantha, to determine the compounds configuration, and to evaluate their antimicrobial activity against eight plant pathogenic fungi (Exserohilum turcicum, Colletotrichum lagenarium, Pseudoperonispora cubensis, Botrytis cirerea, Rhizoctonia solani, Phytophthora parasitica, Fusarium solani, and Pythium aphanidermatum, and four plant pathogenic bacteria (gram negative bacteria: Ralstonia dolaanacearum, Xanthomonas oryzae pv. Oryzae, Xanthomonas Campestris pv. Vesicatoria, and Xanthomonas campestris pv. Citri, and four bacteria (gram positive bacteria: Staphyloccocus aureus, Bacillus subtilis, Micrococcus luteus, and Bacillus cereus. METHODS AND RESULTS: Antimicrobial constituents of the leaves of M. micrantha were isolated using bioactivity- guided fractionation. The antifungal activity of the isolated compounds was evaluated by the inhibit hypha growth method and inhibit spore germination method. Characterization of antibacterial activity was carried out using the minimum inhibitory concentrations (MICs and the minimum bactericidal concentrations (MBCs. MIC and MBC were determined by the broth microdilution method. Six compounds - deoxymikanolide, scandenolide, dihydroscandenolide, mikanolide, dihydromikanolide, and m - methoxy benzoic acid - have been isolated from leaves of Mikania micrantha H. B. K. Deoxymikanolide, scandenolide, and dihydroscandenolide were new compounds. The result of bioassay showed that all of isolated compounds were effective against tested strains and deoxymikanolide showed the strongest activity. CONCLUSIONS AND SIGNIFICANCE: The leaves of M. micrantha may be a promising source in the search for new antimicrobial drugs due to its efficacy and the broadest range. Meanwhile, adverse impact of M. micrantha will be eliminated.

  16. Bioactive proifle of Plakortis nigra, a sea sponge from Mauritius Islands

    Institute of Scientific and Technical Information of China (English)

    Sandrine Tangman; Joyce Govinden Soulange; Daniel Marie

    2015-01-01

    Objective:To investigate the in vitro antibacterial and antioxidant activities of crude and fractionated extracts of the Plakortis nigra (P. nigra) sea sponge from Mauritius sea waters. Methods:Preliminary qualitative chemical screening of the sponge extracts was conducted by using standard methods while the total phenolic content (TPC) was estimated through the Folin-Ciocalteu method. Antibacterial activity was evaluated against Staphylococcus aureus, Escherichia coli and Proteus mirabilis. The minimum inhibitory concentration was determined by the broth microdilution method. All sponge extracts were assessed for antioxidant activity via the 1,1-diphenyl-2-picrylhydrazyl free radical scavenging in vitro model. Results:Alkaloids, phenols, steroids, terpenoids, tannins and saponins were detected in the sponge extracts and TPC varied from (2.280±0.072) mg to (12.790±0.236) mg gallic acid equivalents per gram extract (P Conclusions:The present study validates the antioxidant and antibacterial activity of marine sponge (P. nigra) extracts and depicts the sea sponge as a potential source of pharmaceutical leads against infectious and degenerative diseases.

  17. In Vitro Activities of Ertapenem (MK-0826) against Recent Clinical Bacteria Collected in Europe and Australia

    Science.gov (United States)

    Livermore, David M.; Carter, Michael W.; Bagel, Simone; Wiedemann, Bernd; Baquero, Fernando; Loza, Elena; Endtz, Hubert P.; van den Braak, Nicole; Fernandes, Clarence J.; Fernandes, Lorna; Frimodt-Moller, Niels; Rasmussen, Laura S.; Giamarellou, Helen; Giamarellos-Bourboulis, Evangelos; Jarlier, Vincent; Nguyen, Jacqueline; Nord, Carl-Erik; Struelens, Marc J.; Nonhoff, Caire; Turnidge, John; Bell, Jan; Zbinden, Reinhard; Pfister, Stefan; Mixson, Lori; Shungu, Daniel L.

    2001-01-01

    those of the broth microdilution method for ertapenem. PMID:11353638

  18. In vitro study on the antimicrobial effect of hydroalcoholic extracts from Mentha arvensis L. (Lamiaceae against oral pathogens=Estudo in vitro do efeito antimicrobiano dos extratos hidroalcólicos de Mentha arvensis L. (Lamiaceae contra patógenos orais

    Directory of Open Access Journals (Sweden)

    Rogério Antonio Freitag

    2012-10-01

    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 g 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. Testes in vitro podem ser uma ferramenta valiosa para a avaliação da atividade antimicrobiana de plantas medicinais. Mentha arvensis é uma das plantas medicinais brasileiras mais frequentemente utilizadas e pertence à família Lamiaceae. No presente estudo, extratos hidroalcólicos de M. arvensis foram analisados quanto à sua atividade antimicrobiana sobre Streptococcus mutans, Streptococcus sobrinus e Candida albicans. Três diferentes ensaios (métodos de difusão em ágar, macro e microdiluição em caldo foram utilizados para avaliação da atividade antimicrobiana. Embora os extratos hidroalcólicos de M. arvensis não demonstraram qualquer efeito antibacteriano, eles apresentaram atividade antifúngica contra C. albicans. Baseado no ensaio de microdiluição em caldo, a CIM do extrato hidroalcólico das folhas de M. arvensis sobre cepas de C. albicans

  19. A comparative study of cultural methods for the detection of Salmonella in feed and feed ingredients

    Directory of Open Access Journals (Sweden)

    Haggblom Per

    2009-02-01

    Full Text Available Abstract Background Animal feed as a source of infection to food producing animals is much debated. In order to increase our present knowledge about possible feed transmission it is important to know that the present isolation methods for Salmonella are reliable also for feed materials. In a comparative study the ability of the standard method used for isolation of Salmonella in feed in the Nordic countries, the NMKL71 method (Nordic Committee on Food Analysis was compared to the Modified Semisolid Rappaport Vassiliadis method (MSRV and the international standard method (EN ISO 6579:2002. Five different feed materials were investigated, namely wheat grain, soybean meal, rape seed meal, palm kernel meal, pellets of pig feed and also scrapings from a feed mill elevator. Four different levels of the Salmonella serotypes S. Typhimurium, S. Cubana and S. Yoruba were added to each feed material, respectively. For all methods pre-enrichment in Buffered Peptone Water (BPW were carried out followed by enrichments in the different selective media and finally plating on selective agar media. Results The results obtained with all three methods showed no differences in detection levels, with an accuracy and sensitivity of 65% and 56%, respectively. However, Müller-Kauffmann tetrathionate-novobiocin broth (MKTTn, performed less well due to many false-negative results on Brilliant Green agar (BGA plates. Compared to other feed materials palm kernel meal showed a higher detection level with all serotypes and methods tested. Conclusion The results of this study showed that the accuracy, sensitivity and specificity of the investigated cultural methods were equivalent. However, the detection levels for different feed and feed ingredients varied considerably.

  20. Antioxidant and Antimicrobial Potential, and HPLC Analysis of Stictic and Usnic Acids of Three Usnea Species from Uludag Mountain (Bursa, Turkey).

    Science.gov (United States)

    Oran, Seyhan; Sahin, Saliha; Sahinturk, Pinar; Ozturk, Sule; Demir, Cevdet

    2016-01-01

    In this study, antioxidant and antimicrobial potentials of Usnea intermedia, U. filipendula, and U. fulvoreagens and their stictic and usnic acid contents were investigated. Antioxidant activity and total phenolic contents were evaluated in acetone, ethanol, and methanol extracts of these three species. Antioxidant activity was measured by ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)] method and total phenolic contents were measured by Folin-Ciocalteu method. High-performance liquid chromatography (HPLC) was used for the determination of lichen acids. It can be concluded from stictic and usnic acids contents that the order of solvent efficiency is acetone > ethanol > methanol and acetone > methanol > ethanol, respectively. Broth microdilution method was performed to determine the minimum inhibitory concentration (MIC) of the methanol extracts of three Usnea species. The MIC values of all the extracts ranged from 64 µg/mL to 512 µg/mL for all the bacterial strains that were tested in this study, and all the Fluoro quinolone-resistant Escherichia coli isolates (except for E101) were sensitive to the methanol extracts of the three Usnea species. This paper is the first study to determine the stictic acid content in U. intermedia and U. filipendula. Our findings indicate that these three Usnea species could be used as antioxidant and antimicrobial agents. PMID:27642324

  1. Anti tuberculosis drug resistance in west of Iran

    Directory of Open Access Journals (Sweden)

    Parviz Mohajeri

    2014-01-01

    Full Text Available Background and Objective: Mycobacterium tuberculosis has developed resistance to antituberculosis drugs and becoming a major and alarming public health problem in worldwide. This study was aimed to determine antituberculosis drug resistance rate and to identify multidrug resistant tuberculosis (MDR-TB in West of Iran. Materials and Methods: Of 130 samples were included between December 2011 and July 2012 in the study from that 112 cases were M. tuberculosis. The proportional method was carried out according to the Clinical and Laboratory Standards Institute on Lowenstein-Jensen against isoniazid, rifampicin, streptomycin, ethambutol, pyrazinamide, para aminosalicylic acid, ethionamide, cycloserine (CYC. The microdilution method was carried out using 7H9 broth with 96 well-plates. Results: From 112 isolates, resistance was observed to isoniazid 18 (16.07%, rifampicin 16 (14.28%, streptomycin 25 (22.32%, ethambutol 15 (13.39%, pyrazinamide 27 (24.10%, para aminosalicylic acid 19 (16.96%, CYC 4 (3.57%, and ethionamide 14 (12.5% cases. 16 isolates were MDR. Conclusion: The high prevalence of MDR-TB in our study is assumed to be due to recent transmission of drug-resistant strains. Overall, the rate of drug resistance in our study was high, which is in line with findings of some high-burden countries. Hence that early case detection, rapid drug susceptibility testing, and effective anti-TB treatment is necessary.

  2. Antibacterial and antifungal activity of Terminalia arjuna Wight & Arn. bark against multi-drug resistant clinical isolates

    Institute of Scientific and Technical Information of China (English)

    Sukalyani Debnath; Diganta Dey; Sudipta Hazra; Subhalakshmi Ghosh; Ratnamala Ray; Banasri Hazra

    2013-01-01

    Objective: To evaluate antimicrobial activity of Terminalia arjuna (T. arjuna) bark against clinical strains of multi-drug resistant bacteria, and Candida spp. isolated from patients, as well as the corresponding reference strains.Methods:were evaluated by agar-well diffusion method, followed by determination of minimum inhibitory concentration (MIC) by broth micro-dilution method. The clinical isolates were studied for antibacterial susceptibility by Kirby and Bauer disk diffusion technique. The antimicrobial activity of water, methanol and chloroform extracts of T. arjuna bark Results: The water and methanolic extracts of T. arjuna bark produced significant zones of inhibition against twenty-two tested bacteria including eight uropathogens. MIC values against the bacteria were found in the range of 0.16 to 2.56 mg/mL. The chloroform extract did not exhibit antibacterial activity. The polar extracts of T. arjuna also demonstrated strong antifungal effect against eight species of Candida, with MIC between 0.16 and 0.64 mg/mL. The antimicrobial efficacy of the polar extracts was found to be commensurate with high polyphenol content in contrast to the non-polar (chloroform fraction). Conclusions: This study has revealed the therapeutic prospect of T. arjuna bark for the treatment of microbial diseases. The polar fraction of the bark could be used for development of novel antimicrobial agents, particularly against urinary tract infections, and candidiasis/candidaemia.

  3. EVALUATION OF ANTIBACTERIAL ACTIVITY OF CAFFEINE

    Directory of Open Access Journals (Sweden)

    Pawar Pruthviraj

    2011-04-01

    Full Text Available The present study was carried out with water soluble portion and pure solvent of the acetone, ethanol, methanol, acetonitrile, water extracts of leaves and leaf buds of Camellia sinensis (green tea, and beans of Coffea arabica (coffee. Caffeine (3,7-dihydro-1, 3,7-trimethyl-1H-purine-2,6-dione was isolated from both plants using a liquid-liquid extraction method, detected on thin layer chromatography (TLC plates in comparison with standard caffeine, which served as a positive control. After performing the gross behavioral study, the Antibacterial activity was evaluated against Gram-negative bacteria included; Escherichia coli, Proteus mirabilis, Klebsiella pneumonia and Pseudomonas aeruginosa Both compounds at a concentration of 2 mg/ml showed similar antibacterial activities against all tested bacteria, except for P. mirabilis, and the highest inhibitory effect was observed against P. aeruginosa using a modified agar diffusion method. The minimal inhibitory concentration (MIC of caffeine was determined using a broth microdilution method in 96 multi-well microtitre plates. MIC values ranged from 65.5 to 250.0 µg/ml for the caffeine isolated from coffee and 65.5 to 500.0 µg/ml for green tea caffeine. Combination results showed additive effects against most pathogenic bacteria especially for P. aeruginosa, using both antibacterial assays.

  4. Susceptibility of Staphylococcus aureus Clinical Isolates to Propolis Extract Alone or in Combination with Antimicrobial Drugs

    Directory of Open Access Journals (Sweden)

    Mieczysław Sajewicz

    2013-08-01

    Full Text Available The objective of this study was to assess in vitro the antimicrobial activity of ethanolic extract of Polish propolis (EEPP against methicillin-sensitive Staphylococcus aureus (MSSA and methicillin-resistant Staphylococcus aureus (MRSA clinical isolates. The combined effect of EEPP and 10 selected antistaphylococcal drugs on S. aureus clinical cultures was also investigated. EEPP composition was analyzed by a High Performance Liquid Chromatography (HPLC method. The flavonoid compounds identified in Polish Propolis included flavones, flavonones, flavonolols, flavonols and phenolic acids. EEPP displayed varying effectiveness against twelve S. aureus strains, with minimal inhibitory concentration (MIC within the range from 0.39 to 0.78 mg/mL, determined by broth microdilution method. The average MIC was 0.54 ± 0.22 mg/mL, while calculated MIC50 and MIC90 were 0.39 mg/mL and 0.78 mg/mL, respectively. The minimum bactericidal concentration (MBC of the EEPP ranged from 0.78 to 3.13 mg/mL. The in vitro combined effect of EEPP and 10 antibacterial drugs was investigated using disk diffusion method-based assay. Addition of EEPP to cefoxitin (FOX, clindamycin (DA, tetracycline (TE, tobramycin (TOB, linezolid (LIN, trimethoprim+sulfamethoxazole (SXT, penicillin (P, erythromycin (E regimen, yielded stronger, cumulative antimicrobial effect, against all tested S. aureus strains than EEPP and chemotherapeutics alone. In the case of ciprofloxacin (CIP and chloramphenicol (C no synergism with EEPP was observed.

  5. Antimicrobial action of zinc oxide nanoparticles in combination with ciprofloxacin and ceftazidime against multidrug-resistant Acinetobacter baumannii.

    Science.gov (United States)

    Ghasemi, F; Jalal, R

    2016-09-01

    Acinetobacter baumannii is a serious concern amongst hospitalised patients worldwide and its resistance to antibiotics has emerged as a threat to public health in recent years. Metal oxide nanoparticles were found to be effective for overcoming bacterial resistance owing to their antibacterial activities. The aim of this study was to investigate the combined effects of zinc oxide nanoparticles (ZnO-NPs) and the conventional antibiotics ciprofloxacin and ceftazidime as well as their mechanisms of action against resistant A. baumannii. ZnO-NPs were prepared by the solvothermal method and were characterised by various methods. Broth microdilution and disk diffusion methods were used to determine the antibacterial activities of ciprofloxacin and ceftazidime antibiotics in the absence and presence of a subinhibitory concentration of ZnO-NPs. The mechanism of action of ZnO-NPs alone and in combination with these antibiotics was assessed by flow cytometry, DNA extraction, fluorescence and scanning electron microscopy. The results showed that the antibacterial activities of both antibiotics increased in the presence of a subinhibitory concentration of ZnO-NPs. Combination of ZnO-NPs with antibiotics increased the uptake of antibiotics and changed the bacterial cells from rod to cocci forms. Bacterial filamentation was also observed and exhibited no DNA fragmentation. In conclusion, the results of this study indicate that ZnO-NPs potentiate the antimicrobial action of ciprofloxacin and ceftazidime. A mechanism is proposed to explain this phenomenon. PMID:27530853

  6. In vitro Synergistic Antimicrobial Activity of Romanian Propolis and Antibiotics against Escherichia coli Isolated from Bovine Mastitis

    Directory of Open Access Journals (Sweden)

    Mihaela NICULAE

    2015-12-01

    Full Text Available The study was aimed to characterize the chemical composition and the antimicrobial activity of Romanian propolis ethanolic extracts (EEP against antibiotic-sensitive and antibiotic-resistant E. coli strains isolated from bovine mastitis. The preliminary antimicrobial screening was performed by a disk diffusion method, followed by determination of minimum inhibitory concentrations (MIC and minimum bactericidal concentrations (MBC based on broth microdilution assay; further, the synergistic action of propolis with antimicrobial drugs was assessed by a disk diffusion method on agar containing subinhibitory concentrations of propolis. For the chemical characterisation of EEP, the flavonoids (flavones/flavonols, flavanones/dihydroflavonols and total phenolics were evaluated by spectrophotometric methods. The phenolic compounds of these extracts were also determined using HPLC. The results indicated for Romanian propolis ethanolic extracts the typical poplar composition profile with flavonoids and phenolic acids as main biological active compounds, with chromatographic analysis data confirmed also spectrophotometrically. In addition, positively correlated with the chemical composition, a strong antimicrobial efficacy was exhibited towards E. coli strains, along with interesting synergistic interaction with antibiotics that can be further investigated to obtain propolis-based formulation with antibacterial properties. Subsequent in vitro and in vivo studies evaluating the safety and efficacy are intended to consider propolis in veterinary therapeutic protocols.

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

    Science.gov (United States)

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

    2013-10-01

    Malassezia pachydermatis and Candida parapsilosis are recognized as commensal yeasts on the skin of healthy dogs but also causative agents of eborrheic dermatitis, especially in atopic dogs. We determined and compared the susceptibility levels of yeasts isolated from dogs with and without seborrheic dermatitis (SD) using the disk diffusion method (DD) for itraconazole (ITZ), ketoconazole (KTZ), nystatin (NYS), terbinafine (TERB) and 5-fluorocytosine (5-FC) and the broth microdilution method (BMD) for ITZ and KTZ. The reliability between the methods was assessed using an agreement analysis and linear regression. Forty-five M. pachydermatis and 28 C. parapsilosis isolates were identified based on physiological characteristics and an approved molecular analysis. By DD, all tested M. pachydermatis isolates were susceptible to ITZ, KTZ, NYS and TERB but resistant to 5-FC. Only 46 - 60% of the tested C. parapsilosis isolates were susceptible to KTZ, TERB and 5-FC, but ITZ and NYS were effective against all. By BMD, over 95% of M. pachydermatis isolates were susceptible to KTZ and ITZ with an MIC90 dogs with and without SD. KTZ and ITZ were still efficacious for M. pachydermatis but a high rate of KTZ resistant was reported in C. parapsilosis. PMID:23547880

  8. Chemical composition of three Parmelia lichens and antioxidant, antimicrobial and cytotoxic activities of some their major metabolites.

    Science.gov (United States)

    Manojlović, Nedeljko; Ranković, Branislav; Kosanić, Marijana; Vasiljević, Perica; Stanojković, Tatjana

    2012-10-15

    The aim of this study is to investigate chemical composition of acetone extracts of the lichens Parmelia caperata, P. saxatilis and P. sulcata and antioxidant, antimicrobial and anticancer activities of some their major metabolites. The phytochemical analysis of acetone extracts of three Parmelia lichens were determined by HPLC-UV method. The predominant phenolic compounds in these extracts were protocetraric and usnic acids (P. caperata) and depsidone salazinic acid (other two species). Besides these compounds, atranorin and chloroatranorin, were also detected in some of these extracts. Antioxidant activity of their isolated metabolites was evaluated by free radical scavenging, superoxide anion radical scavenging and reducing power. As a result of the study salazinic acid had stronger antioxidant activity than protocetraric acid. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. Both compounds were highly active with minimum inhibitory concentration values ranging from 0.015 to 1mg/ml. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. Salazinic acid and protocetraric acid were found to be strong anticancer activity toward both cell lines with IC(50) values ranging from 35.67 to 60.18μg/ml. The present study shows that tested lichen compounds demonstrated a strong antioxidant, antimicrobial, and anticancer effects. That suggest that these lichens can be used as new sources of the natural antimicrobial agents, antioxidants and anticancer compounds. PMID:22921748

  9. Comparison of growth methods and biological activities of brazilian marine Streptomyces

    Directory of Open Access Journals (Sweden)

    A. C. Granato

    2013-03-01

    Full Text Available The present work describes the study of the growth and the cytotoxic and antitumor activities of the extracts of the marine microorganisms Streptomyces acrymicini and Streptomyces cebimarensis, the latter a new strain. Both microorganisms were collected from coastal marine sediments of the north coast of São Paulo state. Growth was performed in a shaker and in a bioreactor using Gym medium and the broths of both microorganisms were extracted with ethyl acetate and n-butanol. Three extracts, two organic and one aqueous, from each microorganism were obtained and tested for cytotoxic and antitumor activity using the SF-295 (Central Nervous System, HCT-8 (Colon cell lines, and the MTT (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide method. The growth methods were compared and show that, although the shaker presented reasonable results, the bioreactor represents the best choice for growth of these microorganisms. The biological activity of the different extracts was evaluated and it was demonstrated that the growth methodology may influence the secondary metabolite production and the biological activity.

  10. Novel Plasmid Transformation Method Mediated by Chrysotile, Sliding Friction, and Elastic Body Exposure

    Directory of Open Access Journals (Sweden)

    Naoto Yoshida

    2007-01-01

    Full Text Available Escherichia coli as a plasmid recipient cell was dispersed in a chrysotile colloidal solution, containing chrysotile adsorbed to plasmid DNA (chrysotile-plasmid cell mixture. Following this, the chrysotile-plasmid cell mixture was dropped onto the surface of an elastic body, such as agarose, and treated physically by sliding a polystyrene streak bar over the elastic body to create friction. Plasmid DNA was easily incorporated into E. coli, and antibiotic resistance was conferred by transformation. The transformation efficiency of E. coli cultured in solid medium was greater than that of E. coli cultured in broth. To obtain greater transformation efficiency, we attempted to determine optimal transformation conditions. The following conditions resulted in the greatest transformation efficiency: the recipient cell concentration within the chrysotileplasmid cell mixture had an optical density greater than or equal to 2 at 550 nm, the vertical reaction force applied to the streak bar was greater than or equal to 40 g, and the rotation speed of the elastic body was greater than or equal to 34 rpm. Under these conditions, we observed a transformation efficiency of 107 per μg plasmid DNA. The advantage of achieving bacterial transformation using the elastic body exposure method is that competent cell preparation of the recipient cell is not required. In addition to E. coli, other Gram negative bacteria are able to acquire plasmid DNA using the elastic body exposure method.

  11. Influence of human urine to antimicrobial susceptibility of clinical isolates of Klebsiella pneumoniae and Escherichia coli producing β-lactamase of different types

    Directory of Open Access Journals (Sweden)

    Ž. Žagar

    2007-02-01

    Full Text Available The purpose of the study was to determine the influence of human urine on the antibiotic susceptibilities of Klebsiella pneumoniae and Escherichia coli strains producing different types of extended-spectrum β-lactamases (ESBL. The study was performed on 26 ESBL negative strains of K. pneumoniae, 80 K. pneumoniae strains producing SHV-ESBLs (52-SHV-5, 31- SHV-2 and 7- SHV-12, 94 E. coli strains harbouring TEM- ESBLs and 14 E. coli strains possessing CTX-M group 1 β-lactamases. The minimum inhibitory concentrations of amoxycillin alone and combined with clavulanate (co-amoxilcav, cephalexin, cefuroxime, ceftazidime, cefotaxime, ceftriaxone, cefepime, gentamicin and ciprofloxacin were performed in parallel in Mueller-Hinton broth and urine by broth microdilution method. With ESBL negative strains, urine increased MIC90 of amoxycillin alone and combined with clavulanate, cephalexin, cefuroxime, ceftazidime, cefotaxime, ceftriaxone, cefepime, gentamicin and ciprofloxacin. Against SHV-5 producers, an increase in MIC90 was observed with cefotaxime, cefepime and ciprofloxacin when the test was performed in urine. SHV-2 producers showed elevated MIC90 of ceftazidime, cefotaxime, ceftriaxone and cefepime in the presence of urine, in contrast to SHV-12 producers which displayed elevated MIC90 only for cefotaxime. Urine increased MIC90 of amoxycillin/clavulanate, ceftazidime and cefepime against CTX-M producers, and of amoxycillin/clavulanate, cefotaxime, ceftriaxone, cefepime and ciprofloxacin for TEM producers. According to our results the activity of antibiotics used for the treatment of urinary tract infection could be overestimated by a standard in vitro testing. However, most of antibiotics used for the treatment of urinary tract infection achieve very high concentration in urine and that could abrogate the reduction of antimicrobial activity by biological fluid.

  12. Microsatellite typing and susceptibilities of serial Cryptococcus neoformans isolates from Cuban patients with recurrent cryptococcal meningitis

    Directory of Open Access Journals (Sweden)

    Klaassen Corné HW

    2010-10-01

    Full Text Available Abstract Background Cryptococcus neoformans is commonly associated with meningoencephalitis in immunocompromised patients and occasionally in apparently healthy individuals. Recurrence of infection after initial treatment is not uncommon. We studied C. neoformans isolates from 7 Cuban patients with recurrent cryptococcal meningitis. Antifungal susceptibility and genotyping with microsatellite molecular typing were carried out. Methods Isolates (n = 19 were recovered from cerebrospinal fluid, blood, urine and semen. Antifungal susceptibilities for amphotericin B, fluconazole, flucytosine, itraconazole, voriconazole, posaconazole and isavuconazole were tested by CLSI M27A3 broth microdilution method. Genotyping was done using a panel of 9 microsatellite (STR markers: (CTn, (TGn, (TAn, (CTAn, (TCTn, (CCAn, (TTATn, (ATCCn and (TATTn. Results The average number of isolates/patient was 2.71. The mean time interval between the collection of any two isolates was 52.5 days. All strains were identified as C. neoformans var. grubii (serotype Aα. Although none of the strains were resistant to the studied drugs, in serial isolates from two patients, MICs values of triazoles increased 4-5 log2 dilutions over time. STR patterns showed 14 distinctive profiles. In three patients the recurrent infection was associated with genotypically identical isolates. The four other patients had relapse isolates which were genotypically different from the initial infecting strain. Conclusion Recurrences of cryptococcal meningitis in our series of patients was not associated with development of drug resistance of the original strain but by an initial infection with different strains or a reinfection with a new strain.

  13. Phytochemical analysis, antimicrobial and radical-scavenging properties of Acalypha manniana leaves.

    Science.gov (United States)

    Noumedem, Jaures Ak; Tamokou, Jean de Dieu; Teke, Gerald Ngo; Momo, Rosine Cd; Kuete, Victor; Kuiate, Jules Roger

    2013-01-01

    Acalypha manniana (Euphorbiaceae) is a plant popularly used in Cameroon and in several parts of Africa for the treatment of various microbial diseases like diarrhea and skin infections. The present study was designed to evaluate the phytochemical composition, antimicrobial and radical-scavenging activities of A. manniana methanol leaf extract and its fractions. The methanol extract was partitioned into hexane, ethyl acetate and residual fractions and phytochemical analysis was conducted using standard methods. The broth microdilution method was used to evaluate the antimicrobial activity against nine bacterial species and four dermatophyte species. The free radical scavenging activities of the methanol extract and its fractions were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The results obtained showed that A. manniana contains alkaloids, tannins, anthocyanins, flavonoids, phenols and steroids. The methanol extract as well as the hexane, ethyl acetate and residual fractions exhibited both antibacterial and antidermatophytic activities that varied between the microbial species (MIC = 0.12 - 2.04 mg/mL). These tested samples also showed high radical-scavenging activities (RaS50 = 3.34 - 4.80 μg/mL) when compared with vitamin C used as reference antioxidant (RaS50 = 1.74 μg/mL). These findings provide evidence that the studied plant possesses antimicrobial and antioxidant properties and may act as potential antioxidant for biological systems susceptible to free radical-mediated reactions.

  14. β-Aescin at subinhibitory concentration (sub-MIC) enhances susceptibility of Candida glabrata clinical isolates to nystatin.

    Science.gov (United States)

    Franiczek, Roman; Gleńsk, Michał; Krzyżanowska, Barbara; Włodarczyk, Maciej

    2015-11-01

    Aescin (escin) derived from the seeds of horse chestnut (Aesculus hippocastanum L.) is a natural mixture of triterpene saponins exhibiting a wide variety of pharmacological properties, including antiinflammatory, analgesic, and antipyretic activities. However, data concerning antifungal activities of these compounds are limited. This study aims to evaluate the in vitro antifungal susceptibility of Candida glabrata clinical isolates to α-aescin sodium, β-aescin crystalline and β-aescin sodium using the disk diffusion (DD) and broth microdilution (BMD) methods. Moreover, the influence of subinhibitory concentration (0.5×MIC) of β-aescins on the nystatin MIC was also studied. In general, the results obtained by the DD assay correlated well with those obtained by the BMD method. Both β-aescins effectively inhibited the growth of all 24 strains tested. The minimum inhibitory concentration (MIC) values ranging from 8 to 32 μg/ml for β-aescin crystalline, whereas those of β-aescin sodium were slightly lower and ranged from 4 to 16 μg/ml. In contrast, α-aescin sodium was found to be completely ineffective against the strains studied. MIC values of nystatin were reduced 2-16-fold and 2-4-fold in the presence of subinhibitory concentration of β-aescin crystalline and β-aescin sodium, respectively. Results of the present study may suggest the additive interaction between β-aescin and nystatin. PMID:26092104

  15. In vitro activities of natural products against oral Candida isolates from denture wearers

    Directory of Open Access Journals (Sweden)

    Marcos-Arias Cristina

    2011-11-01

    Full Text Available Abstract Background Candida-associated denture stomatitis is a frequent infectious disease. Treatment of this oral condition is difficult because failures and recurrences are common. The aim of this study was to test the in vitro antifungal activity of pure constituents of essentials oils. Methods Eight terpenic derivatives (carvacrol, farnesol, geraniol, linalool, menthol, menthone, terpinen-4-ol, and α-terpineol, a phenylpropanoid (eugenol, a phenethyl alcohol (tyrosol and fluconazole were evaluated against 38 Candida isolated from denture-wearers and 10 collection Candida strains by the CLSI M27-A3 broth microdilution method. Results Almost all the tested compounds showed antifungal activity with MIC ranges of 0.03-0.25% for eugenol and linalool, 0.03-0.12% for geraniol, 0.06-0.5% for menthol, α-terpineol and terpinen-4-ol, 0.03-0.5% for carvacrol, and 0.06-4% for menthone. These compounds, with the exception of farnesol, menthone and tyrosol, showed important in vitro activities against the fluconazole-resistant and susceptible-dose dependent Candida isolates. Conclusions Carvacrol, eugenol, geraniol, linalool and terpinen-4-ol were very active in vitro against oral Candida isolates. Their fungistatic and fungicidal activities might convert them into promising alternatives for the topic treatment of oral candidiasis and denture stomatitis.

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

    Institute of Scientific and Technical Information of China (English)

    Duraipandiyan V; Ignacimuthu S

    2011-01-01

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

  17. Antimicrobial activity of Gel-entrapped catechins toward oral microorganisms.

    Science.gov (United States)

    Tamura, Muneaki; Saito, Hideo; Kikuchi, Kuniyoshi; Ishigami, Tomohiko; Toyama, Yoshio; Takami, Masao; Ochiai, Kuniyasu

    2011-01-01

    The oral cavity contains almost half of the commensal bacterial population present in the human body. An increase in the number of these microorganisms may result in systemic diseases such as infective endocarditis and aspiration pneumonia as well as oral infections. It is essential to control the total numbers of these microorganisms in order to suppress disease onset. Thus, we examined the antimicrobial activity of a newly developed gel-entrapped catechin (GEC) preparation against oral microorganisms. The minimum inhibitory concentration (MIC) of GEC was determined based on the relationship between a modified agar diffusion method and a broth microdilution method. GEC inhibited the growth of the Actinomyces, periodontopathic bacteria and Candida strains tested, but did not inhibit the growth of the oral streptococci that are important in the normal oral flora. Commercially available moisture gels containing antimicrobial components showed antimicrobial activity against all of the tested strains. After a series of washes and after a 24-h incubation, GEC retained the antimicrobial activity of the catechins. Catalase prevented GEC-induced growth inhibition of Actinomyces naeslundii and Streptococcus mutans suggesting that hydrogen peroxide may be involved in the antimicrobial activity of catechins. These results suggest that GEC may be useful for controlling oral microorganism populations and reducing the accumulation of dental plaque, thereby helping to prevent periodontal disease and oral candidiasis. PMID:21532150

  18. Determination of the antibiofilm, antiadhesive, and anti-MRSA activities of seven Salvia species

    Directory of Open Access Journals (Sweden)

    Amal G Al-Bakri

    2010-01-01

    Full Text Available Background: Several Salvia species are indigenous to Jordan and are widely used as beverages and spices and for their medicinal properties. The objective of the study was to establish the antimicrobial activities, including the antiadhesive and antibiofilm effects of seven different Salvia species. Materials and Methods: Methods used for planktonic culture included agar diffusion, broth microdilution, and minimal biocidal concentration determination while viable count was used for the determination of the antibiofilm and antiadhesion activities. Overnight cultures of reference strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus and clinical strains of methicillin-resistant S. aureus (MRSA were used as test microorganisms. Results: An antimicrobial activity toward planktonic cultures demonstrated a significant bacteriocidal activity (≥4 log cycle reduction for the S. triloba extract against S. aureus including MRSA. Its volatile oil exhibited an antimicrobial activity covering all tested microorganisms with the exception of P. aeruginosa. S. triloba extract and volatile oil were successful in preventing and controlling the biofilm, demonstrating antiadhesion and antibiofilm activities, respectively. Conclusion: These reported activities for S. triloba extract and volatile oil allows their listing as potential antibiofilm and anti-MRSA natural agents. This might suggest their use as an antiseptic in the prophylaxis and treatment of S. aureus-associated skin infections. The antimicrobial activity of the other tested Salvia species was negligible.

  19. Charcterization of Type Ⅱ Topoisomerase Gene Mutations in Clinical Isolates of Mycoplasma Hominis Resistant to Fluoroquinolones

    Institute of Scientific and Technical Information of China (English)

    吴移谋; 张文波; 姚艳冰

    2002-01-01

    Objective: To analyze type Ⅱ topoisomerase genes inclinical isolates of fluoroquinolone-resistant Mycoplasmahominis. Methods: Eight isolates of M.hominis cross resistant to 6fluoroquinolones were selected from 103 clinical strains ofM.hominis using a broth microdilution method. Type IItopoisomerase genes were amplified by PCR and directlysequenced. Nucleotide sequences were compared to sequencesfrom a susceptible strain (M.hominis PG2I). Results: MICs of resistant Mh isolates were 4- to 512-fold higher than MICs from the susceptible reference strain.Sequence comparison revealed a C to T change at 113nt ingyrA QRDR led to the substitution of Ser83 by Leucine and noamino acid change in gyrB. A change of G to T at 134nt inparC QRDR led to the substitution of Ser80 by Isoleucine anda G to A change at 70nt in parE QRDR led to the substitutionof Aspartic acid by Asparagine. Conclusion: These results suggest that a C to T change atll3nt in gyrA, a G to T change at 134nt in parC and a G to Achange at 70nt in patrE are associated with fluoroquinoloneresistance of M.hominis.

  20. Pilot Screening to Determine Antimicrobial Synergies in a Multidrug-Resistant Bacterial Strain Library

    Science.gov (United States)

    Kim, Si-Hyun; Park, Chulmin; Chun, Hye-Sun; Choi, Jae-Ki; Lee, Hyo-Jin; Cho, Sung-Yeon; Park, Sun Hee; Choi, Su-Mi; Choi, Jung-Hyun; Yoo, Jin-Hong

    2016-01-01

    With the rise in multidrug-resistant (MDR) bacterial infections, there has been increasing interest in combinations of ≥2 antimicrobial agents with synergistic effects. We established an MDR bacterial strain library to screen for in vitro antimicrobial synergy by using a broth microdilution checkerboard method and high-throughput luciferase-based bacterial cell viability assay. In total, 39 MDR bacterial strains, including 23 carbapenem-resistant gram-negative bacteria, 9 vancomycin-intermediate Staphylococcus aureus, and 7 vancomycin-resistant Enterococcus faecalis, were used to screen for potential antimicrobial synergies. Synergies were more frequently identified with combinations of imipenem plus trimethoprim–sulfamethoxazole for carbapenem-resistant Acinetobacter baumannii in the library. To verify this finding, we tested 34 A. baumannii clinical isolates resistant to both imipenem and trimethoprim–sulfamethoxazole by the checkerboard method. The imipenem plus trimethoprim–sulfamethoxazole combination showed synergy in the treatment of 21 (62%) of the clinical isolates. The results indicate that pilot screening for antimicrobial synergy in the MDR bacterial strain library could be valuable in the selection of combination therapeutic regimens to treat MDR bacterial infections. Further studies are warranted to determine whether this screening system can be useful to screen for the combined effects of conventional antimicrobials and new-generation antimicrobials or nonantimicrobials. PMID:26974861

  1. Combination Therapy of Sophoraflavanone B against MRSA: In Vitro Synergy Testing

    Directory of Open Access Journals (Sweden)

    Su-Hyun Mun

    2013-01-01

    Full Text Available Sophoraflavanone B (SPF-B, a known prenylated flavonoid, was isolated from the roots of Desmodium caudatum. The aim of this study was to determine the antimicrobial synergism of SPF-B combined with antibiotics against methicillin-resistant Staphylococcus aureus (MRSA. MRSA, a multidrug-resistant pathogen, causes both hospital- and community-acquired infections worldwide. The antimicrobial activity of SPF-B was assessed by the broth microdilution method, checkerboard dilution test, and time-kill curve assay. The MIC of SPF-B for 7 strains of S. aureus ranges from 15.6 to 31.25 μg/mL determined. In the checkerboard method, the combinations of SPF-B with antibiotics had a synergistic effect; SPF-B markedly reduced the MICs of the β-lactam antibiotics: ampicillin (AMP and oxacillin (OXI; aminoglycosides gentamicin (GET; quinolones ciprofloxacin (CIP and norfloxacin (NOR against MRSA. The time-kill curves assay showed that a combined SPF-B and selected antibiotics treatment reduced the bacterial counts below the lowest detectable limit after 24 h. These data suggest that the antibacterial activity of SPF-B against MRSA can be effectively increased through its combination with three groups of antibiotics (β-lactams, aminoglycosides, and quinolones. Our research can be a valuable and significant source for the development of a new antibacterial drug with low MRSA resistance.

  2. Study of Antibacterial Effect of Novel Thiazole, Imidazole and Tetrahydropyridine Derivatives against Escherichia coli

    Directory of Open Access Journals (Sweden)

    Behzad Ghasemi

    2016-01-01

    Full Text Available > Introduction: Escherichia coli is one of the important pathogens in human with globalimportance. Because of the necessity for identification and the use of novel antibacterialcompounds against E. coli, in this present study we focused on the antibacterial effects ofsynthesized thiazole, imidazole and tetrahydropyridine derivatives on E. coli.Methods: For evaluation of antibacterial effect, the disk diffusion method was applied to measurethe growth inhibition zone diameter and broth micro-dilution was performed to determine theminimum inhibitory concentration (MIC.Results: Assessing the antibacterial effect showed that only 6d derivative of thiazole hadinhibitory effect on E. coli and the other thiazole, imidazole and tetrahydropyridine derivativeslacked any inhibitory result on this organism. The inhibitory effect of 6d derivative of thiazolewas MIC=125 and growth inhibition zone diameter of 16±0.1.Discussion: The antibacterial effect of thiazole, imidazole and tetrahydropyridine derivativesdiffers from each other and chemical linkages such as oxygen to thiazole ring in 6d derivative,could have reinforced this effect. The next step is determination of the toxicity and therapeuticeffects in the laboratory animals.

  3. Antibacterial and antioxidant activities in extracts of fully grown cladodes of 8 cultivars of cactus pear.

    Science.gov (United States)

    Sánchez, E; Dávila-Aviña, J; Castillo, S L; Heredia, N; Vázquez-Alvarado, R; García, S

    2014-04-01

    The antimicrobial and antioxidant activities of some cultivars of the nopal cactus have not been determined. In this study, 8 cultivars of nopal cacti from Mexico were assayed for phenolic content, antioxidant activities, and antimicrobial activities against Campylobacter Jejuni, Vibrio cholera, and Clostridium Perfringens. Plant material was washed, dried, and macerated in methanol. Minimum bactericidal concentrations (MBCs) were determined using the broth microdilution method. Antioxidant activities were quantitatively determined using spectrophotometric methods. The MCBs of the nopal cacti ranged from 1.1 to 12.5 mg/mL for c. jejuni, 4.4 to 30 mg/mL for V. cholera, and 0.8 to 16 mg/mL for C. perfringens in the cultivars Cardon Blanco, Real de Catorce, and Jalpa, respectively. High quantities of total phenols and total flavonoids were found in the Jalpa cacti (3.80 mg of gallic acid equivalent GAE/g dry weight [DW] and 36.64 mg of quercetin equivalents [QE]/g DW, respectively). 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities (RSA) were correlated to bioactive compound contents. The Villanueva cacti had the highest %RSA at 42.31%, and the lowest activity was recorded in Copena V1 at 19.98%. In conclusion, we found that some of the 8 cactus pear cultivars studied may be used for their antioxidant compounds or antimicrobials to control or prevent the contamination of foods. PMID:24621296

  4. Evaluation of the antibacterial activity of Piperaceae extracts and nisin on Alicyclobacillus acidoterrestris.

    Science.gov (United States)

    Ruiz, Suelen P; Anjos, Márcia Maria Dos; Carrara, Vanessa S; Delima, Juliana N; Cortez, Diógenes Aparício G; Nakamura, Tânia U; Nakamura, Celso V; de Abreu Filho, Benício A

    2013-11-01

    Alicyclobacillus acidoterrestris is a gram-positive aerobic bacterium. This bacterium resists pasteurization temperatures and low pH and is usually involved in the spoilage of juices and acidic drinks. The objective of this study was to evaluate the antibacterial activities of nisin and the species Piper (Piperaceae) on A. acidoterrestris. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined by the broth microdilution method. The species Piper aduncum had the lowest MIC and an MBC of 15.6 μg/mL and was selected for fractionation. Six fractions were obtained, and the dichloromethane fraction (F.3) had the lowest MIC/MBC (7.81 μg/mL). The dichloromethane fraction was again fractionized, and a spectral analysis revealed that the compound was prenylated chromene (F.3.7). The checkerboard method demonstrated that the crude extract (CE) of P. aduncum plus nisin had a synergistic interaction (fractional inhibitory concentration [FIC] = 0.24). The bactericidal activity of (F.3.7) was confirmed by the time-kill curve. P. aduncum, nisin, and prenylated chromene exhibited strong antibacterial activity against the spores and vegetative cells of A. acidoterrestris. The results of this study suggest that extracts of the genus Piper may provide an alternative to the use of thermal processing for controlling A. spoilage.

  5. Inhibitory Activity of Artemisia spicigera Essential Oil Against Fungal Species Isolated From Minced Meat

    Directory of Open Access Journals (Sweden)

    Ghajarbeygi

    2015-11-01

    Full Text Available Background Meat is an important source of several nutrients. The capability top of fresh meat to rot, causing the group of studies food science, biological and chemical stability meat consideration. Objectives This study was conducted to examine the inhibitory effect of Artemisias spicigera essential oil against fungal species isolated from minced meat. Materials and Methods Two types of media dichloran 18% glycerol (DG18 agar and dichloran rosebengal chloramphenicol (DRBC agar were selected for the mycological analysis of the minced meat samples. To evaluate the antifungal activity of essential oils, the microdilution broth method based on the CLSI (M27A guideline was used. Results Artemisias spicigera essential oil has an inhibitory effect on the growth of fungi found in samples of minced meat. Aspergillus, Penicillium and Cladosporium were the most common genera on both medium types. Average Minimum Inhibitory Concentration 50 = 1.88 µL/mL and MIC90 = 2 µL/mL were reported. The genus of Mucor with MIC = 1.0 µL/mL was the most sensitive and Aspergilus versicolor was the most resistant species to the essential oil with MIC = 4 µL/mL. Conclusions The results of the present study show a favorable inhibitory effect of Artemisias spicigera essential oil on fungal growth, especially Aspergillus species. According to the results, antifungal components of Artemisias spicigera in different forms are used to prevent fungal pollution.

  6. Evaluation of anti-bacterial and anti-oxidant potential of andrographolide and echiodinin isolated from callus culture of Andrographis paniculata Nees

    Institute of Scientific and Technical Information of China (English)

    Mohammed Arifullah; Nima Dandu Namsa; Manabendra Mandal; Kishore Kumar Chiruvella; Paritala Vikrama; Ghanta Rama Gopal

    2013-01-01

    Objective: To evaluate the anti-bacterial and anti-oxidant activity of andrographolide (AND) and echiodinin (ECH) of Andrographis paniculata. Methods:In this study, an attempt has been made to demonstrate the anti-microbial and anti-oxidant activity of isolated AND and ECH by broth micro-dilution method and 2,2-diphenyl-2-picryl-hydrazyl (DPPH) assay, respectively. Structure elucidation was determined by electro-spray ionization-MSD, NMR (1H and 13C) and IR spectra. Results: AND was effective against most of the strains tested including Mycobacteriumsmegmatis, showing broad spectrum of growth inhibition activity with Minimum inhibitory concentration values against Staphylococcus aureus (100 µg/mL), Streptococcus thermophilus (350 µg/mL) Bacillus subtilis (100 µg/mL), Escherichia coli (50 µg/mL), Mycobacterium smegmatis (200 µg/mL), Klebsiella pneumonia (100 µg/mL), and Pseudomonas aeruginosa (200 µg/mL). ECH showed specific anti-bacterial activity against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa at a concentration higher than 225 µg/mL. Both AND and ECH were not effective against the two yeast strains, Candida albicans and Saccharomyces cerevisiae tested in this study. Conclusion:This preliminary study showed promising anti-bacterial activity and moderate free radical scavenging activity of AND and ECH, and it may provide the scientific rationale for its popular folklore medicines.

  7. Antimicrobial activity of Amazonian oils against Paenibacillus species.

    Science.gov (United States)

    Santos, Roberto Christ Vianna; dos Santos Alves, Camilla Filippi; Schneider, Taiane; Lopes, Leonardo Quintana Soares; Aurich, Carlos; Giongo, Janice Luehring; Brandelli, Adriano; de Almeida Vaucher, Rodrigo

    2012-03-01

    The Gram-positive, spore-forming bacterium Paenibacillus larvae is the primary bacterial pathogen of honeybee brood and the causative agent of American foulbrood disease (AFB). One of the feasible alternative treatments being used for their control of this disease is essential oils. In this study in vitro antimicrobial activity of Andiroba and Copaíba essential oils against Paenibacillus species, including P. larvae was evaluated. Minimal inhibitory concentration (MIC) in Mueller-Hinton broth by the microdilution method was assessed. Andiroba registered MIC values of 1.56-25%, while the MICs values obtained for Copaíba oil were of 1.56-12.5%. In order to determine the time-response effect of essential oils on P. larvae, this microorganism was exposed to the oils for up to 48 h. After 24 h treatment with Andiroba oil and after 48 h treatment with Copaíba oil no viable cells of P. larvae ATCC 9545 were observed. The possible toxic effect of essential oils were assessed by the spraying application method of the same concentrations of MICs. Bee mortality was evident only in treatment with Andiroba oil and the Copaíba oil shows no toxic effects after 10 days of observation. Taking together ours results showed for the first time that these oils presented a high activity against Paenibacillus species showing that Copaíba oil may be a candidate for the treatment or prevention of AFB. PMID:22200645

  8. Combination Therapy of Sophoraflavanone B against MRSA: In Vitro Synergy Testing.

    Science.gov (United States)

    Mun, Su-Hyun; Kang, Ok-Hwa; Joung, Dae-Ki; Kim, Sung-Bae; Seo, Yun-Soo; Choi, Jang-Gi; Lee, Young-Seob; Cha, Seon-Woo; Ahn, Young-Sup; Han, Sin-Hee; Kwon, Dong-Yeul

    2013-01-01

    Sophoraflavanone B (SPF-B), a known prenylated flavonoid, was isolated from the roots of Desmodium caudatum. The aim of this study was to determine the antimicrobial synergism of SPF-B combined with antibiotics against methicillin-resistant Staphylococcus aureus (MRSA). MRSA, a multidrug-resistant pathogen, causes both hospital- and community-acquired infections worldwide. The antimicrobial activity of SPF-B was assessed by the broth microdilution method, checkerboard dilution test, and time-kill curve assay. The MIC of SPF-B for 7 strains of S. aureus ranges from 15.6 to 31.25  μ g/mL determined. In the checkerboard method, the combinations of SPF-B with antibiotics had a synergistic effect; SPF-B markedly reduced the MICs of the β -lactam antibiotics: ampicillin (AMP) and oxacillin (OXI); aminoglycosides gentamicin (GET); quinolones ciprofloxacin (CIP) and norfloxacin (NOR) against MRSA. The time-kill curves assay showed that a combined SPF-B and selected antibiotics treatment reduced the bacterial counts below the lowest detectable limit after 24 h. These data suggest that the antibacterial activity of SPF-B against MRSA can be effectively increased through its combination with three groups of antibiotics ( β -lactams, aminoglycosides, and quinolones). Our research can be a valuable and significant source for the development of a new antibacterial drug with low MRSA resistance. PMID:24319486

  9. Antibacterial Activity of Essential Oils and Plant Extracts of Artemisia (Artemisia annua L. In Vitro

    Directory of Open Access Journals (Sweden)

    Alireza Massiha

    2013-06-01

    Full Text Available Background: Many of the plants used to treat certain diseases, because they have showed antimicrobial activity. In this case, many studies have conducted on antimicrobial and antioxidant activity of Artemisia annua. Materials and Methods: The purpose of this study is to determine the antibacterial effects of aqueous, chloroform, methanol and ethanol extracts of A. annua against eight bacterial species. Antimicrobial activity, minimum inhibitory concentration and minimum bactericidal activity of the essential oil and extract was performed by agar disc diffusion and microdilution broth methods.Results: The obtained results showed antibacterial activity of the organic and chloroformic extracts of Artemisia annua against the tested microorganisms. Presence of tannins, saponins, alkaloids, amino acids, phenolic compounds, quinines and terpenoids were identified in the composition of the obtained extract using mass gas-chromatograph. The best result for the minimum inhibitory Concentration and minimum bactericidal concentration was reported for the 32 mg/ml of chloroformic extract.Conclusion: The results indicate the fact that the extracts and essential oils of the plants can be useful as medicinal or preservatives composition.

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

    Science.gov (United States)

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

    2012-07-01

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

  11. Evaluation of Antimicrobial Activity of Cuminum Cyminum Essential Oil and Extract against Bacterial Strains Isolated from Patients with Symptomatic Urinary Tract Infection

    Directory of Open Access Journals (Sweden)

    Yasaman Saee

    2016-10-01

    Full Text Available Background: Many efforts have been done to find effective agents against resistant pathogens. Cuminum cyminum L. (Cumin is an aromatic plant within the Apiaceae family. It has a variety of purposes and demonstrates antimicrobial and antioxidant properties. This study evaluated the activity of C. cyminum extract and essential oil against bacterial isolates which cause urinary tract infection, including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus agalactiae, group A streptococci, Enterococcus faecalis, Staphylococcus epidermidis, Staphylococcus aureus and Staphylococcus saprophyticus isolated from patients with urinary tract infection.Materials and Methods: Extract was prepared by maceration and essential oil was prepared by hydrodistillation from C. cyminum seeds. The study population was 95 patients with urinary tract infection without malignant diseases, diabetes and immunosupression. After identification of organism, susceptibility testing was carried out by disc diffusion method and MIC values by broth microdilution testing.Results: C. cyminum essential oil can have a better effect on the gram-negative bacteria causing urinary tract infection than gram-positive bacteria. In addition, C. cyminum extract have good activity against both gram- positive and gram-negative bacteria. Our findings also showed that essential oil and extract of C. cyminum has better antibacterial activity on uropathogen isolates than amoxicillin and the difference was significant (P value<0.05 but the activity is not superior to other antibiotics.Conclusion: These results suggest that the essential oil and extract of C. cyminum seeds might be considered as interesting sources of antibacterial components against uropathogenic bacteria.

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

    Directory of Open Access Journals (Sweden)

    Rijs Antonius JMM

    2008-08-01

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

  13. Antibacterial and Antibiofilm Effects of Boron on Different Bacteria.

    Science.gov (United States)

    Sayin, Zafer; Ucan, Uckun Sait; Sakmanoglu, Asli

    2016-09-01

    Boron (B) compounds are used in many fields ranging from medicine to industry. In this study, boric acid (BA) and disodium octaborate tetrahydrate (DOT) were evaluated for their antibacterial effects and antibiofilm capacities on selected strains of clinical and type cultures that are of veterinary concern (Staphylococcus aureus ATCC 25923, Aeromonas hydrophila ATCC 19570, Pseudomonas aeruginosa ATCC 27853, Brucella melitensis Rev1 and field isolates of Vibrio anguillarum, Aeromonas hydrophila, Yersinia ruckeri, Pseudomonas aeruginosa, Lactococcus garvieae, and Brucella abortus). Also, the inhibition of biofilm was monitored by scanning electron microscopy. The lowest MIC values of BA and DOT were measured, by broth method using microdilution, from Pseudomonas aeruginosa ATCC 27853, and were 0.385 and 0.644 mg/ml, respectively. Staphylococcus aureus was the most resistant to both BA and DOT. Using the microplate method, we observed that the strongest positivities for biofilm production were presented by Pseudomonas aeruginosa ATCC 27853 and also a clinical isolate of Lactococcus garviea. Lower values in the MIC scores for both B compounds were tested by measuring the inhibitory effect on biofilm production. We found that all the bacterial strains inhibited biofilm formation with the exception of the Pseudomonas aeruginosa strains for BA only and an isolate of Lactococcus garviea for DOT only. Such effects by BA and DOT are worth discussing in order to find novel approaches for different functions in medicine and industry using the bacteria tested. PMID:26864941

  14. Antifungal activity of selected Malaysian honeys:a comparison with Manuka honey

    Institute of Scientific and Technical Information of China (English)

    Siti Aisyah Sayadi; Rozaini Mohd Zohdi; Nur Salme Suhana Shamshuddin; Muna Syairah Khairy; Nur Ashikin Hasan; Ahmad Syamil Yasin; Kalavathy Ramasamy

    2015-01-01

    Objective:To evaluate four selected Malaysian honey samples from different floral sources (Gelam,Tualang,Nenas and Acacia) for their ability to inhibit the growth of fungi and yeast strains (Candida albicans, Aspergillus niger, Epidermophyton floccosum, Microsporum gypseum, Trichophyton rubrum andTrichophyton mentagrophytes). Methods: The broth microdilution method was used to assess the antifungal activity of honey against yeasts at different concentrations ranging from 0.01% to 70% (v/v). Minimum inhibitory concentration (MIC) of the honeys were determined by visual inspection and spectrophotometric assay. Minimum fungicidal concentration test was performed by further sub-culturing from the plates which showed no visible growth in theMICassay onto Sabroud dextrose agar. Results: All tested Malaysian honeys except Gelam showed antifungal activity against all species analysed, with theMIC ranging from 25% (v/v) to 50% (v/v) whileMIC of Manuka honey ranged between 21% to 53%(v/v).Candida albicans was more susceptible to honey than other species tested. Conclusions: Locally produced honeys exhibited antifungal activity which is less than or equal to that of Manuka honey. Our data showed evidence in support of the therapeutic uses of Malaysian honeys.

  15. Oral colonization by yeasts in HIV-positive patients in Brazil

    Directory of Open Access Journals (Sweden)

    Juliana C. Junqueira

    2012-02-01

    Full Text Available INTRODUCTION: In HIV-infected patients, colonization of the oral cavity by potential pathogenic yeast may lead to development of systemic fungemia. We evaluated the prevalence of yeast in the oral cavity of Brazilian HIV-positive patients and verified whether or not the species characterized were enzymatically active. Furthermore, the species identified were tested for their susceptibility to antifungal treatment. METHODS: Patient saliva and oropharyngeal candidiasis samples were collected from 60 seropositive HIV patients and identified by the API20C system. Enzymatic activity was evaluated by the production of proteinase and phospholipase. Susceptibility to antifungal treatments were determined using the broth microdilution method. RESULTS: the most commonly isolated species were C. albicans (51.56% followed by non-albicans Candida species (43.73%, Trichosporon mucoides (3.12% and Kodamaea ohmeri (1.56%. Oral colonization by association of different species was observed in 42% of the patients. Enzymatic activity was verified in most of species isolated, except for C. glabrata, C. lusitaniae and C. guilliermondii. Resistance to Fluconazole and Amphotericin B was observed in isolates of C. albicans, C. glabrata, C. parapsilosis, C. krusei, and K. ohmeri. CONCLUSION: HIV-positive patients are orally colonized by single or multiple species of yeast that are occasionally resistant to Fluconazole or Amphotericin B.

  16. New tridentate azo-azomethines and their copper(II) complexes: Synthesis, solvent effect on tautomerism, electrochemical and biological studies

    Science.gov (United States)

    Sarigul, Munire; Deveci, Pervin; Kose, Muhammet; Arslan, Ugur; Türk Dagi, Hatice; Kurtoglu, Mukerrem

    2015-09-01

    In this study, three azo-azomethines and their copper(II) complexes were prepared and characterized by analytical and spectroscopic methods. The complexes prepared were found to be mononuclear and the chelation of the ligands to the copper(II) ions occurs through two phenolic oxygens and a nitrogen atom of the azomethine group of the ligand. The tautomeric behaviors of the azo-azomethines in solution were studied by UV-Vis. spectra in three organic solvents with different polarity (CHCl3, DMSO and DMF) at room temperature. The redox behaviors of the azo-azomethines and their Cu(II) complexes were investigated by cyclic voltammetry (CV) in DMSO solution containing 0.1 M tetrabutylammonium tetrafluoroborate (TBATFB) as supporting electrolyte. Additionally, the antibacterial activity was also evaluated by the broth microdilution methods against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. The compounds were found to be less effective against all bacteria tested than two reference antibiotics (ampicillin and gentamicin).

  17. Chemical Composition, Antifungal and Antibiofilm Activities of the Essential Oil of Mentha piperita L.

    Science.gov (United States)

    Saharkhiz, Mohammad Jamal; Motamedi, Marjan; Zomorodian, Kamiar; Pakshir, Keyvan; Miri, Ramin; Hemyari, Kimia

    2012-01-01

    Variations in quantity and quality of essential oil (EO) from the aerial parts of cultivated Mentha piperita were determined. The EO of air-dried sample was obtained by a hydrodistillation method and analyzed by a gas chromatography/mass spectrometry (GC/MS). The antifungal activity of the EO was investigated by broth microdilution methods as recommended by Clinical and Laboratory Standards Institute. A biofilm formation inhibition was measured by using an XTT reduction assay. Menthol (53.28%) was the major compound of the EO followed by Menthyl acetate (15.1%) and Menthofuran (11.18%). The EO exhibited strong antifungal activities against the examined fungi at concentrations ranging from 0.12 to 8.0 μL/mL. In addition, the EO inhibited the biofilm formation of Candida albicans and C. dubliniensis at concentrations up to 2 μL/mL. Considering the wide range of the antifungal activities of the examined EO, it might be potentially used in the management of fungal infections or in the extension of the shelf life of food products.

  18. Synergic antibacterial activity of some essential oils from Lamiaceae

    Directory of Open Access Journals (Sweden)

    Sh. Fahimi

    2015-05-01

    Full Text Available Background and objectives: Despite the vast production of new antibiotics in the last three decades, resistance to these drugs by microorganisms has increased and essential oils (EOs have been recognized to possess antimicrobial properties. Methods:  In the present study, EOs obtained from aerial parts of Thymus vulgaris L., Lavandula angustifolia Mill., Rosmarinus officinalis L. and Mentha piperita L., were evaluated for their single and binary combined antibacterial activities against four Gram-positive and Gram-negative pathogenic bacteria: Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. Results: The results exhibited that some of the tested essential oils revealed antibacterial activities against the examined pathogens using broth microdilution method. Maximum activity of the testedessential oils was obtained from the combination of T. vulgaris and M. piperita essential oils against Staphylococcus aureus (MIC= 0.625 mg/mL. Conclusion: Combinations of the essential oils in this study showed synergic action against some pathogenic microorganisms which could be considered in medical and food industries as preservatives.

  19. Anti-Helicobacter pylori activity and immunostimulatory effect of extracts from Byrsonima crassa Nied. (Malpighiaceae

    Directory of Open Access Journals (Sweden)

    Vilegas Wagner

    2009-01-01

    Full Text Available Abstract Background Several in vitro studies have looked at the effect of medicinal plant extracts against Helicobacter pylori (H. pylori. Regardless of the popular use of Byrsonima crassa (B. crassa as antiemetic, diuretic, febrifuge, to treat diarrhea, gastritis and ulcers, there is no data on its effects against H. pylori. In this study, we evaluated the anti-H. pylori of B. crassa leaves extracts and its effects on reactive oxygen/nitrogen intermediates induction by murine peritoneal macrophages. Methods The minimal inhibitory concentration (MIC was determined by broth microdilution method and the production of hydrogen peroxide (H2O2 and nitric oxide (NO by the horseradish peroxidase-dependent oxidation of phenol red and Griess reaction, respectively. Results The methanolic (MeOH and chloroformic (CHCl3 extracts inhibit, in vitro, the growth of H. pylori with MIC value of 1024 μg/ml. The MeOH extract induced the production H2O2 and NO, but CHCl3 extract only NO. Conclusion Based in our results, B. crassa can be considered a source of compounds with anti-H. pylori activity, but its use should be done with caution in treatment of the gastritis and peptic ulcers, since the reactive oxygen/nitrogen intermediates are involved in the pathogenesis of gastric mucosal injury induced by ulcerogenic agents and H. pylori infections.

  20. Comparative study on the antifungal activity of hydroalcoholic extract of Iranian Propolis and Royal jelly against Rhizopus oryzae

    Directory of Open Access Journals (Sweden)

    Moghim Hassan

    2015-07-01

    Full Text Available Introduction: Mucormycosis is an opportunistic fungal infection. Rhizopus oryzae is major cause of mucormycosis in humans. This disease is the most common form of the acute fungal infection with rapid progress. Iranian Propolis extract and Royal jelly are honey bee products which have been used by human over the past centuries in traditional medicine. In this study the effects of Iranian Propolis and Royal jelly were investigated against Rhizopus oryzae and Candida albicans. Methods: The used method in this study was microdilution. To perform it, the prepared dilutions of Royal jelly and alcoholic extract of Iranian Propolis were added to tubes containing Sabouraud dextrose broth culture media except to control group and then Rhizopus oryzae suspension was added to all microtubes. In the next stage, microtubes were maintained in incubator at 25oC for 48 hours and then 10 ml of the content of each microtube was transferred to Sabouraud dextrose agar media. The minimum inhibitory concentration (MIC and minimum fungicidal concentration (MFC of the agents were calculated. Results: In this study, the MIC and MFC of Iranian Propolis alcoholic extract on Rhizopus oryzae were respectively 0.1 and 0.25 mg/ml and the MFC of Royal jelly on Rhizopus oryzae were respectively 100 ± 34 and 133 ± 46 mg/ml. Conclusion: The results indicate that Propolis might be used as an ideal combination for the treatment of fungal infections like Rhizopus oryzae. However, clinical studies are needed to confirm the effects of these drugs.

  1. Antimicrobial activity of some essential oils against oral multidrug-resistant Enterococcus faecalis in both planktonic and biofilm state

    Science.gov (United States)

    Benbelaïd, Fethi; Khadir, Abdelmounaïm; Abdoune, Mohamed Amine; Bendahou, Mourad; Muselli, Alain; Costa, Jean

    2014-01-01

    Objective To evaluate some essential oils in treatment of intractable oral infections, principally caused by biofilm of multidrug-resistant Enterococcus faecalis (E. faecalis), such as persistent endodontic infections in which their treatment exhibits a real challenge for dentists. Methods Ten chemically analyzed essential oils by gas chromatography-mass spectrometry were evaluated for antimicrobial activity against sensitive and resistant clinical strains of E. faecalis in both planktonic and biofilm state using two methods, disk diffusion and broth micro-dilution. Results Studied essential oils showed a good antimicrobial activity and high ability in E. faecalis biofilm eradication, whether for sensitive or multidrug-resistant strains, especially those of Origanum glandulosum and Thymbra capitata with interesting minimum inhibitory concentration, biofilm inhibitory concentration, and biofilm eradication concentration values which doesn't exceed 0.063%, 0.75%, and 1.5%, respectively. Conclusions Findings of this study indicate that essential oils extracted from aromatic plants can be used in treatment of intractable oral infections, especially caused by biofilm of multidrug-resistant E. faecalis. PMID:25182948

  2. The antibacterial activity of selected plants towards resistant bacteria isolated from clinical specimens

    Institute of Scientific and Technical Information of China (English)

    Pratiwi Wikaningtyas; Elin Yulinah Sukandar

    2016-01-01

    Objective: To evaluate the antibacterial activity of eight plants against methicillin-resistant Staphylococcus aureus (MRSA), extended spectrum beta-lactamase and carbapenemase-resistant Enterobacteriaceae, which are the most prevalent causes of in-fections in inpatients. Methods: The antibacterial activity was calculated based on the minimum inhibitory concentration using Mueller–Hinton broth in a microdilution method. Results: The best antibacterial activity, calculated as minimum inhibitory concentration values, against MRSA was shown by the Kaempferia pandurata (Roxb) (K. pandurata) extract (256 mg/mL) and the Senna alata (S. alata) extract (512 mg/mL). Phytochemical screening of dried S. alata leaf and its extract showed the presence of flavonoids, alka-loids, saponins, quinones, tannins and sterols, while dried K. pandurata and its extract only showed the presence of flavonoids and sterols/triterpenoids. Conclusions: K. pandurata and S. alata have the potential to be developed as antibac-terial agents, especially against MRSA strain, but further in vivo research and discovery of the mode of its action are still needed to shed light on the effects.

  3. Tetrazolium/Formazan Test as an Efficient Method to Determine Fungal Chitosan Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Shaaban H. Moussa

    2013-01-01

    Full Text Available Fungal chitosan was extracted from Aspergillus niger mycelia. The produced chitosan was characterized with deacetylation degree of 89.2%, a molecular weight of 2.4 × 104 Da, and 96.0% solubility in 1% acetic acid solution. The antibacterial activity of fungal chitosan was evaluated against two foodborne pathogens, that is, Salmonella typhimurium and Staphylococcus aureus, using the established antibacterial assays, for example, zone of growth inhibition and agar plat count tests, and using 2,3,5,-triphenyltetrazolium chloride (TTC as chromogenic marker for qualitative and quantitative determining of antibacterial potentiality. The TTC (0.5% w/v was added, at concentration of 10%, to cultured broth, containing chitosan with different concentrations then the formed formazan was separated. The formation of red formazan could be considered as a qualitative indication for antibacterial activity, whereas the measurement of color intensity for the resuspended red formazan, using spectrophotometer at 480 nm, provided a quantitative evidence for the strength of the used antibacterial agent. Regarding the rapidity, technical simplicity, and cost-effectiveness, TTC assay could be recommended as an efficient alternative method for qualitative and quantitative determination of chitosan antibacterial activity and could be suggested for general evaluation of antibacterial agents.

  4. A rapid fluorescence based method for the quantitative analysis of cell culture media photo-degradation.

    Science.gov (United States)

    Calvet, Amandine; Li, Boyan; Ryder, Alan G

    2014-01-01

    Cell culture media are very complex chemical mixtures that are one of the most important aspects in biopharmaceutical manufacturing. The complex composition of many media leads to materials that are inherently unstable and of particular concern, is media photo-damage which can adversely affect cell culture performance. This can be significant particularly with small scale transparent bioreactors and media containers are used for process development or research. Chromatographic and/or mass spectrometry based analyses are often time-consuming and expensive for routine high-throughput media analysis particularly during scale up or development processes. Fluorescence excitation-emission matrix (EEM) spectroscopy combined with multi-way chemometrics is a robust methodology applicable for the analysis of raw materials, media, and bioprocess broths. Here we demonstrate how EEM spectroscopy was used for the rapid, quantitative analysis of media degradation caused by ambient visible light exposure. The primary degradation pathways involve riboflavin (leading to the formation of lumichrome, LmC) which also causes photo-sensitised degradation of tryptophan, which was validated using high pressure liquid chromatography (HPLC) measurements. The use of PARallel FACtor analysis (PARAFAC), multivariate curve resolution (MCR), and N-way partial least squares (NPLS) enabled the rapid and easy monitoring of the compositional changes in tryptophan (Trp), tyrosine (Tyr), and riboflavin (Rf) concentration caused by ambient light exposure. Excellent agreement between HPLC and EEM methods was found for the change in Trp, Rf, and LmC concentrations. PMID:24356227

  5. Methicillin-resistant Staphylococcus aureus in Spain: molecular epidemiology and utility of different typing methods.

    Science.gov (United States)

    Vindel, Ana; Cuevas, Oscar; Cercenado, Emilia; Marcos, Carmen; Bautista, Verónica; Castellares, Carol; Trincado, Pilar; Boquete, Teresa; Pérez-Vázquez, Maria; Marín, Mercedes; Bouza, Emilio

    2009-06-01

    In a point-prevalence study performed in 145 Spanish hospitals in 2006, we collected 463 isolates of Staphylococcus aureus in a single day. Of these, 135 (29.2%) were methicillin (meticillin)-resistant S. aureus (MRSA) isolates. Susceptibility testing was performed by a microdilution method, and mecA was detected by PCR. The isolates were analyzed by pulsed-field gel electrophoresis (PFGE) after SmaI digestion, staphylococcal chromosomal cassette mec (SCCmec) typing, agr typing, spa typing with BURP (based-upon-repeat-pattern) analysis, and multilocus sequence typing (MLST). The 135 MRSA isolates showed resistance to ciprofloxacin (93.3%), tobramycin (72.6%), gentamicin (20.0%), erythromycin (66.7%), and clindamycin (39.3%). Among the isolates resistant to erythromycin, 27.4% showed the M phenotype. All of the isolates were susceptible to glycopeptides. Twelve resistance patterns were found, of which four accounted for 65% of the isolates. PFGE revealed 36 different patterns, with 13 major clones (including 2 predominant clones with various antibiotypes that accounted for 52.5% of the MRSA isolates) and 23 sporadic profiles. Two genotypes were observed for the first time in Spain. SCCmec type IV accounted for 6.7% of the isolates (70.1% were type IVa, 23.9% were type IVc, 0.9% were type IVd, and 5.1% were type IVh), and SCCmec type I and SCCmec type II accounted for 7.4% and 5.2% of the isolates, respectively. One isolate was nontypeable. Only one of the isolates produced the Panton-Valentine leukocidin. The isolates presented agr type 2 (82.2%), type 1 (14.8%), and type 3 (3.0%). spa typing revealed 32 different types, the predominant ones being t067 (48.9%) and t002 (14.8%), as well as clonal complex 067 (78%) by BURP analysis. The MRSA clone of sequence type 125 and SCCmec type IV was the most prevalent throughout Spain. In our experience, PFGE, spa typing, SCCmec typing, and MLST presented good correlations for the majority of the MRSA strains; we suggest the

  6. 甘草查尔酮E对金黄色葡萄球菌的抗菌活性%Antibacterial activity of licochalcone E on Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    邱家章; 邓旭明; 罗永煌

    2012-01-01

    应用肉汤微量稀释法测定甘草查尔酮E对金黄色葡萄球菌(简称金葡菌)的抗菌活性,并通过溶血试验、Western blot分析和荧光定量PCR试验考察亚抑菌浓度的甘草查尔酮E对金葡菌α-溶血素表达的影响。结果显示,甘草查尔酮E对7株金葡菌的最低抑菌质量浓度为2~8mg/L;亚抑菌浓度的甘草查尔酮E能显著降低金葡菌α-溶血素的表达,且呈现剂量依赖性。%A broth micro-dilution method was used to investigate the antimicrobial activity of licochaleone E against Staphylococcus aureus,and the influence of sub-inhibitory concentrations of licochalcone E on the expression of a- toxin by S. aureus was assessed by hemolysis assay,Western blot and real-time RT-PCR. The MICs of licochalcone E against 13 S. aureus strains were ranged from 2 to 8 mg/L;The production of a-toxin in S. aureus was reduced by sub-inhibitory concentrations of licochalcone E in a dose-dependent manner.

  7. Antibacterial activity of three medicinal Thai plants against Campylobacter jejuni and other foodborne pathogens.

    Science.gov (United States)

    Dholvitayakhun, Achara; Cushnie, T P Tim; Trachoo, Nathanon

    2012-01-01

    Leaves of Adenanthera pavonina, Moringa oleifera and Annona squamosa are used in traditional Thai medicine to treat dysentery and other diseases. This study investigated the antibacterial activity of these plants against six species of foodborne pathogen. Methods and solvents employed to extract active constituents were optimised using the disc diffusion assay. Phytochemical analysis of the optimised extracts was performed by thin layer chromatography (TLC). Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined by broth microdilution. A. pavonina contained flavonoids, terpines and tannins, and was the most active extract against Campylobacter jejuni, inhibiting growth at 62.5-125 µg mL(-1). The A. squamosa extract contained flavonoids, terpines, tannins and alkaloids, and had the broadest spectrum of antibacterial activity, inhibiting Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus and C. jejuni between 62.5 and 500 µg mL(-1). MBCs were 2- to 4-fold higher than MICs against C. jejuni and B. cereus, suggesting the extracts are bactericidal against these species. Negligible activity was detected from M. oleifera. The data presented here show that A. pavonina and A. squamosa could potentially be used in modern applications aimed at the treatment or prevention of foodborne diseases. PMID:21878033

  8. Simvastatin inhibits planktonic cells and biofilms ofCandida and Cryptococcusspecies

    Directory of Open Access Journals (Sweden)

    Raimunda Sâmia Nogueira Brilhante

    2015-10-01

    Full Text Available ABSTRACTThe antifungal activity of some statins against different fungal species has been reported. Thus, at the first moment, the in vitro antifungal activity of simvastatin, atorvastatin and pravastatin was tested againstCandida spp. and Cryptococcus spp. Then, in a second approach, considering that the best results were obtained for simvastatin, this drug was evaluated in combination with antifungal drugs against planktonic growth and tested against biofilms ofCandida spp. and Cryptococcus spp. Drug susceptibility testing was performed using the microdilution broth method, as described by the Clinical and Laboratory Standards Institute. The interaction between simvastatin and antifungals against planktonic cells was analyzed by calculating the fractional inhibitory concentration index. Regarding biofilm susceptibility, simvastatin was tested against growing biofilm and mature biofilm of one strain of each tested yeast species. Simvastatin showed inhibitory effect against Candida spp. andCryptococcus spp. with minimum inhibitory concentration values ranging from 15.6 to 1000 mg L-1 and from 62.5 to 1000 mg L-1, respectively. The combination of simvastatin with itraconazole and fluconazole showed synergism against Candidaspp. and Cryptococcus spp., while the combination of simvastatin with amphotericin B was synergistic only againstCryptococcus spp. Concerning the biofilm assays, simvastatin was able to inhibit both growing biofilm and mature biofilm ofCandida spp. and Cryptococcus spp. The present study showed that simvastatin inhibits planktonic cells and biofilms ofCandida and Cryptococcus species.

  9. Green synthesis of silver nanoparticles as antibacterial agent using Rhodomyrtus tomentosa acetone extract

    Science.gov (United States)

    Voravuthikunchai, Supayang P.; Chorachoo, Julalak; Jaiswal, Lily; Shankar, Shiv

    2013-12-01

    The capability of Rhodomyrtus tomentosa acetone extract (RAE) for the production of silver nanoparticles (AgNPs) has been explored for the first time. Silver nanoparticles with a surface plasmon resonance band centered at 420-430 nm were synthesized by reacting RAE with AgNO3. Reaction time, temperature, concentration of AgNO3 and RAE could accelerate the reduction rate of Ag+ and affect AgNPs size. The nanoparticles were found to be 10-30 nm in size and spherical in shape. XRD data demonstrated crystalline nature of AgNPs dominated by (200) facets. FTIR results showed decrease in intensity of peaks at 3394, 1716 and 1618 cm-1 indicating the involvement of O-H, carbonyl group and C=C stretching with the formation of AgNPs with RAE, respectively. The C-O-C and C-N stretching suggested the presence of many phytochemicals on the surface of the nanoparticles. High negative zeta potential values confirmed the stability of AgNPs in water. In vitro antibacterial activity of AgNPs was tested against Staphylococcus aureus using broth microdilution method. AgNPs capped with RAE demonstrated profound antibacterial activity against the organisms with minimum inhibitory concentration and minimum bactericidal concentration in the range between 3.1-6.2 and 6.2-50 μgmL-1, respectively. The synthesized nanoparticles could be applied as an effective antimicrobial agent against staphylococcal infections.

  10. Growth inhibitory effect of grape phenolics against wine spoilage yeasts and acetic acid bacteria.

    Science.gov (United States)

    Pastorkova, E; Zakova, T; Landa, P; Novakova, J; Vadlejch, J; Kokoska, L

    2013-02-15

    This paper investigates the in vitro antimicrobial potential of 15 grape phenolic compounds of various chemical classes (phenolic acids, stilbenes and flavonoids) using the broth microdilution method against yeasts and acetic acid bacteria frequently occurring in deteriorated wine. Pterostilbene (MICs=32-128 μg/mL), resveratrol (MICs=256-512 μg/mL) and luteolin (MICs=256-512 μg/mL) are among six active compounds that possessed the strongest inhibitory effects against all microorganisms tested. In the case of phenolic acids, myricetin, p-coumaric and ferulic acids exhibited selective antimicrobial activity (MICs=256-512 μg/mL), depending upon yeasts and bacteria tested. In comparison with potassium metabisulphite, all microorganisms tested were more susceptible to the phenolics. The results revealed the antibacterial and antiyeast effects against wine spoilage microorganisms of several highly potent phenolics naturally occurring in grapes. These findings also provide arguments for further investigation of stilbenes as prospective compounds reducing the need for the use of sulphites in winemaking.

  11. Chemical Composition and In Vitro Antibacterial Activity of Mentha spicata Essential Oil against Common Food-Borne Pathogenic Bacteria.

    Science.gov (United States)

    Shahbazi, Yasser

    2015-01-01

    The aim of the present study was to investigate chemical composition and antibacterial activity of essential oil from the leaf of Mentha spicata plant against common food-borne pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium, and Escherichia coli O157:H7). Chemical composition of the essential oil was identified by gas chromatography coupled with mass spectrometer detector (GC-MS). The antibacterial activity of the essential oil was evaluated by broth microdilution method and agar disk diffusion assay. According to the result of GC-MS analysis, 18 components were identified, accounting for 99.89% of the whole essential oil. The main components were carvone (78.76%), limonene (11.50%), β-bourbonene (11.23%), cis-dihydrocarveol (1.43%), trans-caryophyllene (1.04%), menthone (1.01%), menthol (1%), and terpinen-4-ol (0.99). The essential oil exhibited moderate level of antibacterial activity against all test microorganisms. In general, Gram-positive bacteria were more susceptible to M. spicata essential oil than Gram-negative bacteria. L. monocytogenes was the most sensitive of the microorganisms to the antibacterial activity of M. spicata essential oil (inhibition zone = 22 mm and MIC and MBC = 2.5 µL/mL). Based on our results, the essential oil of M. spicata plant collected from Kermanshah province, west of Iran, has a potential to be applied as antibacterial agent. PMID:26351584

  12. Serotypes and antimicrobial resistance of meningeal isolates of Streptococcus pneumonia. Cuba, 2007-2012

    Directory of Open Access Journals (Sweden)

    Gilda Toraño-Peraza

    2014-12-01

    Full Text Available An observational study was conducted to know the serotypes and antimicrobial susceptibility of isolates of Streptococcus pneumoniae responsible for meningitis in Cuba, where there is no vaccine yet to prevent invasive pneumococcal disease. The study included the total number of isolates submitted to the "Pedro Kourí" Institute between 2007 and 2012 (N=237. Serotypes identification was performed using capsular swelling test and antimicrobial susceptibility was studied by determining the minimum inhibitory concentration using the broth microdilution method. Predominant serotypes were 6A, 6B, 14, 19F and 23F and other non-vaccinal 18 serogroups/serotypes were identified in 29.1% of the isolates. A tendency to an increased resistance to penicillin (44.3 % was observed; the most common resistance patterns were: penicillin-trimethoprim/sulfamethoxazole and penicillin-erythromycin (21.1% and 10.5%, respectively. The largest number of isolates resistant to penicillin was in serotypes 6B, 14, 19F and 23F and the possibility of resistant non-vaccine serotypes emergence should be considered. The results show that 70.4 % of the isolates studied corresponds to the serotypes included in 13-valent conjugated pneumococcal vaccine, but with 10-valent it would achieve a lower vaccination potential coverage (56.1%. This information must be considered when evaluating the decision to use in Cuba any commercially available vaccine or the proposal of another strategy of vaccination from autochthonous vaccine candidates.

  13. The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives

    Science.gov (United States)

    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 thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes. PMID:23778660

  14. Synthesis and In Vitro Evaluation of New Thiosemicarbazone Derivatives as Potential Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Zafer Asım Kaplancıklı

    2016-01-01

    Full Text Available In an effort to develop potent antimicrobial agents, new thiosemicarbazone derivatives were synthesized via the reaction of 4-[4-(trifluoromethylphenyl]thiosemicarbazide with aromatic aldehydes. The compounds were evaluated for their inhibitory effects on pathogenic bacteria and yeasts using the CLSI broth microdilution method. Microplate Alamar Blue Assay was also carried out to determine the antimycobacterial activities of the compounds against Mycobacterium tuberculosis H37Rv. Among these derivatives, compounds 5 and 11 were more effective against Enterococcus faecalis (ATCC 29212 than chloramphenicol, whereas compounds 1, 2, and 12 and chloramphenicol showed the same level of antibacterial activity against E. faecalis. Moreover, compound 2 and chloramphenicol exhibited the same level of antibacterial activity against Staphylococcus aureus. On the other hand, the most potent anticandidal derivatives were found as compounds 2 and 5. These derivatives and ketoconazole exhibited the same level of antifungal activity against Candida glabrata. According to the Microplate Alamar Blue Assay, the tested compounds showed weak to moderate antitubercular activity.

  15. Antimycobacterial and Antifungal Activities of Selected Four Salvia Species

    Directory of Open Access Journals (Sweden)

    Nur Tan

    2016-03-01

    Full Text Available The content of essential oils of endemic Salvia cilicica was analyzed by GC-FID and GC-MS techniques. Spathulenol (23.8 %, caryophyllene oxide (14.9 % and hexadecanoic acid (10.3 % were identified as the major components in the oil of Salvia cilicica. Additionally, in this study ethanol extracts of the aerial parts and essential oils of four Salvia species ( S. cilicica, S. officinalis, S. fruticosa, S. tomentosa , as well as the roots of S. cilicica were investigated their antimycobacterial and antifungal activities including infectious diseases. The antimycobacterial activity was analyzed against three Mycobacterium tuberculosis (sensitive-, resistant-standard strains and multidrug resistance clinical isolate strains and the antifungal activity was compared with two dermotophytes (Microsporum gypseum and Trichophyton mentagrophytes var. erinacei and three Candida species by the broth microdilution method. The essentials oils of the four tested Salvia species showed high antimycobacterial and antifungal activity (MIC between 0.2-12.5 mcg/mL in comparison to the aerial parts and root extracts . The antifungal and antimycobacterial potential of the ethanol extracts and essential oils were introduced to determine whether, Salvia species can be used in phytotherapy against the yeasts, dermatophytes and M. tuberculosis. To the best of our knowledge this is the first study of S. cilicica about their antimycobacterial and antifungal activities and chemical composition of its essential oils.

  16. Effects of osmotic pressure, acid, or cold stresses on antibiotic susceptibility of Listeria monocytogenes.

    Science.gov (United States)

    Al-Nabulsi, Anas A; Osaili, Tareq M; Shaker, Reyad R; Olaimat, Amin N; Jaradat, Ziad W; Zain Elabedeen, Noor A; Holley, Richard A

    2015-04-01

    Prevalence of antibiotic resistance of Listeria monocytogenes isolated from a variety of foods has increased in many countries. L. monocytogenes has many physiological adaptations that enable survival under a wide range of environmental stresses. The objective of this study was to evaluate effects of osmotic (2, 4, 6, 12% NaC), pH (6, 5.5, 5.0) and cold (4 °C) stresses on susceptibility of three isolates of L. monocytogenes towards different antibiotics. The minimal inhibitory concentrations (MICs) of tested antibiotics against unstressed (control), stressed or post-stressed L. monocytogenes isolates (an ATCC strain and a meat and dairy isolate) were determined using the broth microdilution method. Unstressed cells of L. monocytogenes were sensitive to all tested antibiotics. In general, when L. monocytogenes cells were exposed to salt, cold and pH stresses, their antibiotic resistance increased as salt concentration increased to 6 or 12%, as pH was reduced to pH 5 or as temperature was decreased to 10 °C. Results showed that both meat and dairy isolates were more resistant than the ATCC reference strain. Use of sub-lethal stresses in food preservation systems may stimulate antibiotic resistance responses in L. monocytogenes strains. PMID:25475279

  17. Efficacy of Cuminum cyminum essential oil on FUM1 gene expression of fumonisin-producing Fusarium verticillioides strains

    Directory of Open Access Journals (Sweden)

    Ali Reza Khosravi

    2014-12-01

    Full Text Available Objectives: The purpose of this study was to evaluate the effect of Cuminum cyminum (C. cyminum essential oil on the growth and FUM1 gene expression of fumonisin-producing Fusarium verticillioides (F. verticillioides strains isolated from maize. Materials and Methods: All fungal strains were cultured on potato dextrose agar (PDA slopes at 30°C for 7 days. The antifungal activity was evaluated by broth microdilution assay. One set of primers was F. verticillioides species specific, which selectively amplified the intergenic space region of rDNA. The other set of primers was specific to FUM1 gene region of fumonisin-producing F. verticillioides. FUM1 transcript levels were quantified using a reverse transcription-polymerase chain reaction (RT-PCR protocol. Results: Minimum inhibitory concentration (MIC values of C. cyminum oil against F. verticillioides strains varied from 0.195 to 0.781 µl.ml-1 (mean MIC value: 0.461 µl.ml-1 indicating 54.5% of the fungal strains inhibited at 0.390 µl.ml-1. PCR analysis of FUM1 gene expression revealed that DNA fragment of 183 bp was amplified in all the isolates of F. verticillioides before treatment with C. cyminum essential oil. Based on RT-PCR analyses, reduction in the expression of fumonisin biosynthetic genes was significant only for FUM1 gene (p

  18. Antibacterial efficacy of Mangifera indica L. kernel and Ocimum sanctum L. leaves against Enterococcus faecalis dentinal biofilm

    Directory of Open Access Journals (Sweden)

    Arunajatesan Subbiya

    2013-01-01

    Full Text Available Introduction: The Enterococcus faecalis biofilm in the root canal makes it difficult to be eradicated by the conventional irrigants with no toxicity to the tissues. Hence, plant products with least side effects are explored for their use as irrigants in the root canal therapy. Aim: To evaluate and compare the antibacterial efficacy of Mangifera indica L. kernel (mango kernel and Ocimum sanctum L. leaves (tulsi extracts with conventional irrigants (5% sodium hypochlorite (NaOCl and 2% chlorhexidine against E. faecalis dentinal biofilm. Materials and Methods: Agar diffusion and broth microdilution assay was performed with the herbal extracts and conventional irrigants (2% chlorhexidine and 5% NaOCl against E. faecalis planktonic cells. The assay was extended onto 3 week E. faecalis dentinal biofilm. Results: Significant reduction of colony forming units (CFU/mL was observed for the herbal groups and the antibacterial activity of the herbal groups was at par with 5% NaOCl. Conclusions: The antibacterial activity of these herbal extracts is found to be comparable with that of conventional irrigants both on the biofilm and planktonic counterparts.

  19. Isolation, identification, and monitoring of antibiotic resistance in Pasteurella multocida and Mannheimia haemolytica isolated from sheep in East Azerbaijan province, Iran

    Directory of Open Access Journals (Sweden)

    I. Khalili

    2016-09-01

    Full Text Available The present study was carried out in order to isolate, identify, and assess the antimicrobial susceptibility of the causative agent(s of pneumonic pasteurellosis in sheep in East Azerbaijan province, northwest of Iran. Pneumonia was detected in 320 cases, and the affected lungs were sampled in the slaughterhouse. The samples were investigated bacteriologically for the isolation of two microorganisms from the Pasteurellaceae family. Pasteurella multocida was isolated from six (1.87% samples, while none of the lung tissues were positive for Mannheimia haemolytica. After the isolation and detection of microorganisms via cultural and morphological tests, the bacteria were identified on the basis of biochemical criteria and polymerase chain reaction (PCR technique. Antimicrobial susceptibility testing was performed on all P. multocida isolates, using broth microdilution method. Evaluation of the minimum inhibitory concentration (MIC of eight antimicrobial agents against the tested isolates showed that all the organisms were resistant to amoxicillin and relatively susceptible to ceftiofur. In conclusion, P. multocida was introduced as the main cause of ovine pneumonic pasteurellosis in the studied district, and the outbreak frequency significantly varied in different seasons of the year (P

  20. Carbapenem and multidrug resistance in Gram-negative bacteria in a single centre in Italy: considerations on in vitro assay of active drugs.

    Science.gov (United States)

    Mezzatesta, Maria Lina; Caio, Carla; Gona, Floriana; Cormaci, Roberta; Salerno, Iasmine; Zingali, Tiziana; Denaro, Carmelo; Gennaro, Mauro; Quattrone, Cristiana; Stefani, Stefania

    2014-08-01

    In intensive care units (ICUs), the most important causes of nosocomial bacterial infections are mainly multidrug-resistant (MDR) and extensively drug-resistant (XDR) Acinetobacter baumannii and Klebsiella pneumoniae strains. Mortality related to these infections is very high due to lack of effective therapy and the severity of patient conditions. This study aimed to assess the prevalence of carbapenem resistance genes in 77 carbapenem-resistant Gram-negative bacteria isolated from severe infections (bloodstream, pulmonary and urinary tract) during the period 1 January to 31 July 2013 in a general ICU in Catania, Italy, and to examine their susceptibility to tigecycline and colistin using two different methods. In total, 52 A. baumannii belonging to the same sequence type (ST) 2 clone and carrying the bla(OXA-23) gene as well as 25 K. pneumoniae carrying bla(KPC-3) were isolated. Four distinct pulsotypes were identified in K. pneumoniae, which correlated with four distinct STs: ST258 and ST512, spread worldwide, and ST147 and ST395 detected for the first time in Italy. A. baumannii isolates showed an XDR profile and were fully susceptible only to colistin; all KPC-producing K. pneumoniae isolates were MDR, whilst colistin was active against 19 of 25 strains. These results show that broth microdilution (BMD) is a reliable in vitro susceptibility test for colistin, above all K. pneumoniae, whilst both the gradient test and BMD are suitable for tigecycline susceptibility testing of A. baumannii.