WorldWideScience

Sample records for agar

  1. Inoculation Expedition of Agar wood

    International Nuclear Information System (INIS)

    Peng, C.S.; Mohd Fajri Osman; Rusli Zakaria

    2015-01-01

    Inoculation expedition of agar wood is a main field works for researcher in Nuclear Malaysia to prove the real inoculation of agar wood in real jungle. These expeditions was conducted fourth times in the jungles of Malaysia including Gunung Tebu in Terengganu, Murum in Belaga, Sarawak, Kampung Timbang in Kota Belud, Sabah and Nuclear Malaysia itself. This expedition starts from preparation of samples and equipment, transportation into the jungle, searching and recognition of agar wood and lastly, inoculation of the agar wood. Safety aspects precedence set out in the preparation and implementation of this expedition. (author)

  2. Morphological identification of Candida species on glucose agar, rice extract agar and corn meal agar with and without Tween-80.

    Science.gov (United States)

    Joshi, K R; Solanki, A; Prakash, P

    1993-01-01

    A comparative study for the identification of 32 known strains of Candida species on the basis of morphology on glucose agar, rice extract agar and corn meal agar with and without Tween 80 revealed that when Tween 80 is incorporated in the media identification is possible for 96.8% of the species within 48 hours on rice extract agar and for 96.8% of the species within 48 hours on rice extract agar and for 90.6% of the species on glucose agar. The germ tubes and chlamydospores were also produced more on rice extract agar than on 0.1% glucose agar. Rice extract agar with Tween 80 can be used as single medium for morphologic identification of Candida species. The inoculated medium is first incubated at 37 degrees C for 3 hours and examined for germ tube formation and then incubated at 25 degrees C for 24 to 72 hours and examined for appearance of chlamydospores and mycelial morphology.

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

    Energy Technology Data Exchange (ETDEWEB)

    Velimirovic, Milica; Schmid, Doris; Wagner, Stephan; Micić, Vesna; Kammer, Frank von der; Hofmann, Thilo, E-mail: thilo.hofmann@univie.ac.at

    2016-09-01

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  5. Menu Proposal to Use Powdered Agar

    OpenAIRE

    土屋, ひろ子; 嶋村, 桃子; 小松, 沙霧

    2015-01-01

    The author was involved in the development of the menu items that might be sold at “Taisho Village”, a theme park. Requirements in the menu development were that cooking should be simple as it starts cooking after receiving orders and it should have attractive appearances. Powdered agar has advantages over rod-shaped or string-shaped agar, with easiness of handling such as its ready solubility in water and no need to wash, rehydrate or strain. Because powdered agar is easy to use in cooking,...

  6. Agar from some Hawaiian red algae

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.A.; Doty, M.S.

    1983-08-01

    From describing the agars of Gelidiella acerosa Forskk., Gelidium pluma Loomis, G. pusillum (Stackh.) Lejolis, Gracilaria abbotiana Hoyle, G. bursapastoris (Gmelin) Silva, G. canaliculata (Kutzing) Sonder, G. coronopifolia J.Ag., G. epihippisora Hoyle, Pterocladia caerulescens (Kutzing) Santelices and P. capillacea (Gmelin) Born. and Thur. as found in Hawaiian samples of these species, it is concluded that the species of Gelidium and especially Pterocladia and Gelidiella may merit more consideration for usage due to their agar gel strengths. The nature of the gel from Gracilaria abbottiana suggests the generic status might well be reexamined. The agars from the Gelidiella and the other Gracilaria species should be studied further for their prospective values to the food industry other than gel strength. Mixtures of the agars from G. bursapastoris and G. coronopifolia would merit attention for the taste texture of their mixtures. (Refs. 18).

  7. Morphological development of Morchella conica mycelium on different agar media.

    Science.gov (United States)

    Guler, P; Ozkaya, E G

    2009-07-01

    The present study presents the development of mycelium of Morchella conica where different concentration of sucrose added at different agar media. For this sucrose have been added as 0.25, 0.50, 0.75, 1.00 and 1.25% concentration to wheat agar potato dextrose agar malt extract agar and complete medium yeast agar The radial growth speed, morphologic specifications, radial growth radius and pigmentation of mycelium were taken as criteria, the development period of mycelium in wheat agar was completed in 4 days and mycelium were very thin. The colonization period of the mycelium was determined; 7 days in potato dextrose agar 5 days in malt extract agar and 5 days at complete medium yeast agar. The development of the mycelium; at potato dextrose agar was dense and circular; at malt extract agar and at completed medium yeast agar was rhizomorphic. Mycelium has developed very well at sucrose medium and formed creamy and light yellow pigmentation.

  8. Identification of Cryptococcus neoformans isolates using Staib agar without creatinine

    OpenAIRE

    Nardelli, Vanessa; Pérez, Celina; Mata-Essayag, Sofía; Colella, María Teresa; Roselló, Arantza; Hartung de Capriles, Claudia; Landaeta, María Eugenia; Olaizola, Carolina; Magaldi, Sylvia

    2005-01-01

    In mycology, culture is the best way to demonstrate and identify pathogenic fungi. Many kinds of media have been developed and modified, using fungal biochemical properties to recognize them. The most common media are Sabouraud, Malt Agar, Cornmeal agar, Potato-dextrose agar, and Staib agar. Staib agar has been widely used for identification of yeasts from the genus Cryptococcus and other fungi. The aim of this study was to demonstrate the usefulness of Staib agar, and of a modified Staib med...

  9. STABILITAS ANTOSIANIN JANTUNG PISANG KEPOK (Musa paradisiaca L TERHADAP CAHAYA SEBAGAI PEWARNA AGAR-AGAR

    Directory of Open Access Journals (Sweden)

    Lydia Ninan Lestario

    2015-02-01

    jantung pisang kepok yang disinari dengan intensitas 780-2.214 lux selama 10 jam masih disukai panelis, sedangkan yang disinari dengan intensitas 10.340 sudah tidak disukai panelis. Kata kunci: Antosianin, jantung pisang, agar-agar, intensitas cahaya, laju degradasi warna

  10. Sorption of U(VI) on natural sepiolite and sepiolite-agar agar composite adsorbent

    International Nuclear Information System (INIS)

    Esen, K.; Donat, R.; Cetisli, H.; Aytas, S.

    2006-01-01

    Adsorption of uranium (VI) ions onto clay minerals is one of the significant reactions affecting the transport of uranium in the environment. The use of composite adsorbents for the removal of metal ions and radionuclide from industrial wastes has attracted great interest to researchers in recent years[1]. In this study, natural sepiolite type clay and an organic compound, agar agar, were chosen as the adsorbent material. Composite adsorbent was prepared from sepiolite and agar agar. Adsorption of uranium (VI) on this composite and on natural sepiolite adsorbent was investigated. Thermodynamic investigations were carried out to get more information about the adsorption of uranium. Adsorption of U (VI) has been studied as a function of solution pH, time, temperature and initial concentration of uranium on natural sepiolite and agar agar composite. The maximum sorption yield of U (VI) on composite and on sepiolite from batch experiments is calculated approximately 89% and 76% respectively in the optimum experimental adsorption condition. The adsorption data were fitted to Freundlich and Dubinin-Radushkevich (D-R) adsorption isotherms. Using the experimental data obtained different temperatures, thermodynamic constants ΔH d egree, ΔS d egree and ΔG d egree were calculated. The results show that the adsorption process on natural sepiolite and sepiolite-agar agar composite are both egzothermic natures. [1] S. M. Hasany, M. M. Saeed, M. Ahmed, J. Radioanal. Nucl. Chem. Vol. 252 (3), 477-484 (2002)

  11. Extraction of agar from Gelidium sesquipedale (Rhodopyta) and surface characterization of agar based films.

    Science.gov (United States)

    Guerrero, P; Etxabide, A; Leceta, I; Peñalba, M; de la Caba, K

    2014-01-01

    The chemical structure of the agar obtained from Gelidium sesquipedale (Rhodophyta) has been determined by (13)C nuclear magnetic resonance ((13)C NMR) and Fourier transform infrared spectroscopy (FTIR). Agar (AG) films with different amounts of soy protein isolate (SPI) were prepared using a thermo-moulding method, and transparent and hydrophobic films were obtained and characterized. FTIR analysis provided a detailed description of the binding groups present in the films, such as carboxylic, hydroxyl and sulfonate groups, while the surface composition was examined using X-ray photoelectron spectroscopy (XPS). The changes observed by FTIR and XPS spectra suggested interactions between functional groups of agar and SPI. This is a novel approach to the characterization of agar-based films and provides knowledge about the compatibility of agar and soy protein for further investigation of the functional properties of biodegradable films based on these biopolymers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Micropipette Deflection Measurements of Agar-Glass Adhesion

    Science.gov (United States)

    Parg, Richard; Shelton, Erin; Dutcher, John

    Micropipette deflection experiments were used to study the adhesive strength at an agar-glass interface. Agar is a hydrogel commonly used in biological research; however, many of the mechanical properties of this hydrogel are not well characterized. By measuring the peak force required to slide an agar puck supported by a Teflon ring across a clean glass slide, we are able to compare the adhesive strength of 1 % w/w and 1.5 % w/w agar. On average, the force required to break the agar-glass interface was approximately a factor of 2 larger for 1.5 % w/w agar than for 1 % w/w agar. We discuss this result within the context of a simple model of agar adhesion. Additional experiments were performed to measure the kinetic friction between agar and glass to obtain insight into its dependence on agar concentration.

  13. 21 CFR 866.4600 - Ouchterlony agar plate.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents § 866.4600 Ouchterlony agar plate. (a) Identification. An ouchterlony agar plate for clinical use is a device...

  14. Agar alternatives for micropropagation of African violet ( Saintpaulia ...

    African Journals Online (AJOL)

    Agar is one of the most popular solidifying agents in plant tissue culture. High price of pure grade agar and fear of over exploitation of its resources caused searching for low cost alternatives. In this study, liquid medium with cotton substratum and different combinations of starch, semolina, potato powder and agar in two ...

  15. Gari agar as culture media for mycological studies | Okorondu ...

    African Journals Online (AJOL)

    Gari agar was prepared by weighing 28 g of Gari, 14 g of agar powder and 8 g of Hibiscus rabdariffa powder to 1 L of sterile water. A conventional media, Sabouraud Dextrose Agar (SDA) was prepared as control according to manufacturer's procedure. Aliquot of appropriate dilutions of 1 g of agricultural soil was inoculated ...

  16. Radiation sterilization of triple sugar iron agar

    International Nuclear Information System (INIS)

    Altmann, G.; Eisenberg, E.; Bogokowsky, B.

    1979-01-01

    Triple sugar iron agar (TSI), a medium used for the identification of enteric bacteria, was sterilized by gamma radiation using radiation doses of 750-2000 krad. The radio-sterilized medium, slightly modified by increasing its Phenol Red content, performed well when tested with different enterobacteriaceae and other gram negative bacteria. Growth, change of indicator reaction in slant and butt and formation of gas and H 2 S were equal in irradiated and autoclaved TSI. Slants of irradiated TSI in stoppered plastic tubes kept their diagnostic properties during storage for at least 4 months. Gamma irradiation appears to be an attractive and economical method of sterilising nutrient media in sealed tubes or other containers, avoiding the risk of contamination during processing. (author)

  17. Estudio comparativo del agar Iso-Sensitest y el agar Mueller-Hinton

    Directory of Open Access Journals (Sweden)

    Margaret Ordoñez Smith de Danies

    1993-12-01

    Full Text Available Se estudiaron 710 cepas bacterianas provenientes de diferentes muestras para comparar las zonas de inhibición de los diámetros obtenidos en agar Iso-Sensitest y el agar Mueller Hinton. Se realizaron bajo la técnica de difusión en disco de la NCCLS (Comité Nacional para los Estándares de Laboratorio Clínico. Estadísticamente, al analizar el chi-cuadrado de las muestras estudiadas, se observó una confiabilidad del 99%, por lo tanto no hay diferencia entre los dos medios de cultivo. En el agar Iso-Sensitest se obtuvo una mejor nitidez con los diámetros de los halos de inhibición, se encontró un 62,0% de mejor lectura o mayor visibilidad en los diámetros de las zonas de inhibición con los cultivos de Enterococcus sp., un 21,4% con el Staphylococcus aureus y 20,0% en el caso de la Providencia stuartii.

  18. Seasonal variations of agar extracted from different life stages of ...

    African Journals Online (AJOL)

    Seasonality in yield, physical and chemical properties of the native agar from different life stages of Gracilaria cliftonii was investigated over a period of six seasons (autumn 2008–winter 2009). Agar yield and its properties varied as a function of seasons and life stages but there was no significant correlation between ...

  19. Methods for identifying lipoxygenase producing microorganisms on agar plates

    NARCIS (Netherlands)

    Nyyssola, A.; Heshof, R.; Haarmann, T.; Eidner, J.; Westerholm-Parvinen, A.; Langfelder, K.; Kruus, K.; Graaff, de L.H.; Buchert, J.

    2012-01-01

    Plate assays for lipoxygenase producing microorganisms on agar plates have been developed. Both potassium iodide-starch and indamine dye formation methods were effective for detecting soybean lipoxygenase activity on agar plates. A positive result was also achieved using the beta-carotene bleaching

  20. Assessment of Native Agar Gels Extracted from Gracilaria debilis ...

    African Journals Online (AJOL)

    Native agar gels extracted from Gracilaria debilis and G. salicornia harvested during the rainy and dry seasons, were assessed for culturing the microorganisms Micrococcus luteus, Saccharomyces cerevisiae and Pleurotus flabellatus. Agars extracted from plants harvested during the rainy season were suitable for culturing ...

  1. AGAR PENULISAN RESEP TETAP UP TO DATE

    Directory of Open Access Journals (Sweden)

    Rahmatini Rahmatini

    2009-09-01

    Full Text Available AbstrakResep adalah suatu permintaan tertulis dari dokter, dokter gigi atau dokter hewan kepada apoteker untuk membuatkan obat dalam bentuk sediaan tertentu dan menyerahkannya kepada pasien. Resep merupakan perwujudan akhir dari kompetensi, pengetahuan dan keahlian dokter dalam menerapkan pengetahuannya dalam bidang farmakologi dan terapi.Penulisan resep harus ditulis dengan jelas sehingga dapat dibaca oleh petugas di apotek. Resep yang ditulis dengan tidak jelas akan menimbulkan terjadinya kesalahan saat peracikan / penyiapan obat dan penggunaan obat yang diresepkan.Ilmu pengetahuan tentang obat selalu berubah, obat – obat baru selalu muncul di pasaran.Secara umum, seorang dokter harus mengikuti perkembangan dalam terapi obat. Bila muncul efek samping akibat obat yang seharusnya diketahui dan dapat dicegah oleh dokter, maka dokter akan berhadapan dengan hukum.Agar penulisan resep tetap up to date, seorang dokter harus mengumpulkan berbagai informasi yang tersedia. Sumber informasi yang dapat digunakan adalah : Buku acuan, Kompendium obat, Daftar Obat Esensial Nasional (DOEN dan Pedoman terapi, Buletin obat, Jurnal Kedokteran, Pusat informasi obat,Informasi melalui komputer, Sumber informasi dari industri farmasi, dan informasi lisan.Bandingkan kelebihan dan kekurangan berbagai sumber informasi. Tugas seorang dokter adalah melakukan cara terbaik untuk tetap up to date dengan mendaftar sumber informasi yang dapat dimanfaatkan. Carilah sedikitnya satu dari yang berikut ini : (1 jurnal kedokteran: (2 buletin obat; (3 buku acuan farmakologi atau acuan klinis; (4 komisi terapi maupun konsultan, atau lulusan pasca sarjana farmakologi. Dengan bekal pengetahuan dan kemampuan untuk melakukan penilaian secara kritis setiap bentuk informasi, diharapkan dokter tetap up to date dalam menulis resepKata kunci : Resep – up to- date.Abstract Prescription is a written request from a doctor, dentist or veterinarian to the pharmacist to make a particular drug

  2. Suitability of various plant derived gelling agents as agar substitute ...

    African Journals Online (AJOL)

    USER

    2012-06-05

    Jun 5, 2012 ... of three test fungi (Trichoderma harzianum, Alternaria alternata and Alternaria solani) as good as agar. ... used for cell culture, derived from plants or animals and .... and used to jell various foods, drugs and cosmetics) and rice.

  3. Rheological properties of agar and carrageenan from Ghanaian red seaweeds

    DEFF Research Database (Denmark)

    Rhein-Knudsen, Nanna; Ale, Marcel Tutor; Ajalloueian, Fatemeh

    2017-01-01

    spectroscopy (FTIR) analysis on the hydrocolloids extracted from H. musciformis (and K. alvarezii) indicated κ-carrageenan, C. crenulata hydrocolloids were mainly ι-carrageenan, and the H. dentata hydrocolloids were agar. Gelling temperatures ranged from 32 to 36 °C for the κ-carrageenan hydrocolloid samples...... comparable with κ-carrageenan from K. alvarezii, whereas the H. dentata agar properties were different from those of a commercial agar sample. This work shows that certain red seaweed species in Ghana contain hydrocolloids with desirable properties for high value applications....... and Cryptonemia crenulata, expected to hold carrageenan, contained 21–26% by weight of galactose. A commercial Kappaphycus alvarezii carrageenan sample had 30% galactose residues by weight. Hydropuntia dentata, expected to contain agar, contained 15% by weight of galactose-monomers. Fourier transform infrared...

  4. Hichrom candida agar for identification of candida species

    OpenAIRE

    Baradkar V; Mathur M; Kumar S

    2010-01-01

    Chromogenic media are frequently used in direct and rapid identification of yeasts because different Candida species produce unique colors on these media. We used 60 isolates of Candida species including 30 C. albicans, 10 C. parapsilosis, 11 C. glabrata, five C. tropicalis, and four C. dubliniensis, isolated from various clinical specimens, to evaluate the performance of HiChrome Candida agar. These strains had been identified by germ tube test, morphology on cornmeal agar, chlamydospore for...

  5. Detection of extracellular proteases from microorganisms on agar plates

    Directory of Open Access Journals (Sweden)

    Alane Beatriz Vermelho

    1996-12-01

    Full Text Available We present herein an improved assay for detecting the presence of extracellular proteases from microorganisms on agar plates. Using different substrates (gelatin, BSA, hemoglobin incorporated into the agar and varying the culture medium composition, we were able to detect proteolytic activities from Pseudomonas aeruginosa, Micrococcus luteus and Serratia marcescens as well as the influence that these components displayed in the expression of these enzymes. For all microorganisms tested we found that in agar-BHI or yeast extract medium containing gelatin the sensitivity of proteinase detection was considerably greater than in BSA-agar or hemoglobin-agar. However, when BSA or hemoglobin were added to the culture medium, there was an increase in growth along with a marked reduction in the amount of proteinase production. In the case of M. luteus the incorporation of glycerol in BHI or yeast extract gelatin-agar induced protease liberation. Our results indicate that the technique described here is of value for detecting extracellular proteases directly in the culture medium, by means of a qualitative assay, simple, inexpensive, straight forward method to assess the presence of the proteolytic activity of a given microorganism colony with great freedom in substrate selection.

  6. Thermal characterization of magnetically aligned carbonyl iron/agar composites.

    Science.gov (United States)

    Diaz-Bleis, D; Vales-Pinzón, C; Freile-Pelegrín, Y; Alvarado-Gil, J J

    2014-01-01

    Composites of magnetic particles into polymeric matrices have received increasing research interest due to their capacity to respond to external magnetic or electromagnetic fields. In this study, agar from Gelidium robustum has been chosen as natural biocompatible polymer to build the matrix of the magnetic carbonyl iron particles (CIP) for their uses in biomedical fields. Heat transfer behavior of the CIP-agar composites containing different concentrations (5, 10, 15, 20, 25 and 30% w/w) of magnetically aligned and non-aligned CIP in the agar matrix was studied using photothermal radiometry (PTR) in the back-propagation emission configuration. The morphology of the CIP-agar composites with aligned and non-aligned CIP under magnetic field was also evaluated by scanning electron microscopy (SEM). The results revealed a dominant effect of CIP concentration over the alignment patterns induced by the magnetic field, which agrees with the behavior of the thermal diffusivity and thermal conductivity. Agar served as a perfect matrix to be used with CIP, and CIP-agar composites magnetically aligned at 20% CIP concentration can be considered as promising 'smart' material for hyperthermia treatments in the biomedical field. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Differentiating Agar wood Oil Quality Using Artificial Neural Network

    International Nuclear Information System (INIS)

    Nurlaila Ismail; Nor Azah Mohd Ali; Mailina Jamil; Saiful Nizam Tajuddin; Mohd Nasir Taib

    2013-01-01

    Agar wood oil is well known as expensive oil extracted from the resinous of fragrant heartwood. The oil is getting high demand in the market especially from the Middle East countries, China and Japan because of its unique odor. As part of an on-going research in grading the agar wood oil quality, the application of Artificial Neural Network (ANN) is proposed in this study to analyze agar wood oil quality using its chemical profiles. The work involves of selected agar wood oil from low and high quality, the extraction of chemical compounds using GC-MS and Z-score to identify of the significant compounds as input to the network. The ANN programming algorithm was developed and computed automatically via Matlab software version R2010a. Back-propagation training algorithm and sigmoid transfer function were used to optimize the parameters in the training network. The result obtained showed the capability of ANN in analyzing the agar wood oil quality hence beneficial for the further application such as grading and classification for agar wood oil. (author)

  8. A comparison of EF-18 agar and modified brilliant green agar with lutensit for isolation of Salmonella from poultry samples

    DEFF Research Database (Denmark)

    Petersen, Line Hedegård

    1997-01-01

    -Vassiliadis broth, and 3) Plating onto EF-18 agar and BGA/L simultaneously. From a total of 1101 samples, Salmonella was isolated from 158, 157 of which were faecal samples. Thirtyone of these isolates were recovered on one medium only, 18 could not be found on BGA/L and 13 could not be found on EF-18 agar....... The relative specificity and sensitivity of each plating agar was determined by enumeration of false-positive and false-negative reactions. EF-18 agar compared favourably with BGA/L, displaying a sensitivity of 0.92 as opposed to 0.89 for BGA/L, calculated for the ''fecal samples'' group only. The calculated...... specificities for each group of samples were likewise considerably higher for EF-18 agar (0.75-0.91) than for BGA/L (0.35-0.55). Though EF-18 agar is slightly more expensive than BGA/L, the routine use of the former may result in a considerable reduction in overall laboratory costs due to its superior...

  9. Agar/collagen membrane as skin dressing for wounds

    Energy Technology Data Exchange (ETDEWEB)

    Bao Lei; Yang Wei; Mao Xuan; Mou Shansong; Tang Shunqing [Biomedical Engineering Institute, Jinan University, Guangzhou (China)], E-mail: tshunqt@jnu.edu.cn, E-mail: tmuss@jnu.edu.cn

    2008-12-15

    Agar, a highly hydrophilic polymer, has a special gel property and favorable biocompatibility, but moderate intension strength in an aqueous condition and a low degradation rate. In order to tailor both properties of mechanical intension and degradation, type I collagen was composited with agar in a certain ratio by drying at 50 {sup 0}C or by a freeze-dry process. Glutaraldehyde was chosen as a crosslinking agent, and the most favorable condition for crosslinking was that the weight ratio of agar to glutaraldehyde was 66.7 and the pH value about 5. Dynamic mechanical analysis results showed that the single agar membrane had a modulus value between 640 MPa and 1064 MPa, but it was between 340 MPa and 819 MPa after being composited with type I collagen. It was discovered under an optical microscope that the pores were interconnected in the composite scaffolds instead of the honeycomb-like pores in a single type I collagen scaffold or the laminated gaps in a single agar scaffold. The results of an acute toxicity test disclosed that the composites were not toxic to mice although the composites were crosslinked with a certain concentration of glutaraldehyde. The results of gross examinations showed that when the composite membranes or scaffolds were applied to a repair rabbit skin lesion, the composites had a good repair effect without infection, liquid exudation or visible scar in the lesion covered with them. But in the control group, the autologous skin showed necrosis and there were a lot of scar tissues in the lesion site. H and E staining results showed that the repair tissue was similar to the normal one and very few scaffolds or membranes were left without degradation after 2 or 3 weeks. In conclusion, it is proved that type I collagen increases the toughness of the agar membrane, and the agar/type I collagen composites are promising biomaterials as wound dressings for healing burns or ulcers.

  10. Agar/collagen membrane as skin dressing for wounds

    International Nuclear Information System (INIS)

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

    2008-01-01

    Agar, a highly hydrophilic polymer, has a special gel property and favorable biocompatibility, but moderate intension strength in an aqueous condition and a low degradation rate. In order to tailor both properties of mechanical intension and degradation, type I collagen was composited with agar in a certain ratio by drying at 50 0 C or by a freeze-dry process. Glutaraldehyde was chosen as a crosslinking agent, and the most favorable condition for crosslinking was that the weight ratio of agar to glutaraldehyde was 66.7 and the pH value about 5. Dynamic mechanical analysis results showed that the single agar membrane had a modulus value between 640 MPa and 1064 MPa, but it was between 340 MPa and 819 MPa after being composited with type I collagen. It was discovered under an optical microscope that the pores were interconnected in the composite scaffolds instead of the honeycomb-like pores in a single type I collagen scaffold or the laminated gaps in a single agar scaffold. The results of an acute toxicity test disclosed that the composites were not toxic to mice although the composites were crosslinked with a certain concentration of glutaraldehyde. The results of gross examinations showed that when the composite membranes or scaffolds were applied to a repair rabbit skin lesion, the composites had a good repair effect without infection, liquid exudation or visible scar in the lesion covered with them. But in the control group, the autologous skin showed necrosis and there were a lot of scar tissues in the lesion site. H and E staining results showed that the repair tissue was similar to the normal one and very few scaffolds or membranes were left without degradation after 2 or 3 weeks. In conclusion, it is proved that type I collagen increases the toughness of the agar membrane, and the agar/type I collagen composites are promising biomaterials as wound dressings for healing burns or ulcers.

  11. Light transfer in agar immobilized microalgae cell cultures

    Science.gov (United States)

    Kandilian, Razmig; Jesus, Bruno; Legrand, Jack; Pilon, Laurent; Pruvost, Jérémy

    2017-09-01

    This paper experimentally and theoretically investigates light transfer in agar-immobilized cell cultures. Certain biotechnological applications such as production of metabolites secreted by photosynthetic microorganisms require cells to be immobilized in biopolymers to minimize contamination and to facilitate metabolite recovery. In such applications, light absorption by cells is one of the most important parameters affecting cell growth or metabolite productivity. Modeling light transfer therein can aid design and optimize immobilized-cell reactors. In this study, Parachlorella kessleri cells with areal biomass concentrations ranging from 0.36 to 16.9 g/m2 were immobilized in 2.6 mm thick agar gels. The average absorption and scattering cross-sections as well as the scattering phase function of P. kessleri cells were measured. Then, the absorption and transport scattering coefficients of the agar gel were determined using an inverse method based on the modified two-flux approximation. The forward model was used to predict the normal-hemispherical transmittance and reflectance of the immobilized-cell films accounting for absorption and scattering by both microalgae and the agar gel. Good agreement was found between the measured and predicted normal-hemispherical transmittance and reflectance provided absorption and scattering by agar were taken into account. Moreover, good agreement was found between experimentally measured and predicted mean rate of photon absorption. Finally, optimal areal biomass concentration was determined to achieve complete absorption of the incident radiation.

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

    Science.gov (United States)

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

    2005-06-01

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

  13. Hichrom candida agar for identification of Candida species.

    Science.gov (United States)

    Baradkar, V P; Mathur, M; Kumar, S

    2010-01-01

    Chromogenic media are frequently used in direct and rapid identification of yeasts because different Candida species produce unique colors on these media. We used 60 isolates of Candida species including 30 C. albicans, 10 C. parapsilosis, 11 C. glabrata, five C. tropicalis, and four C. dubliniensis, isolated from various clinical specimens, to evaluate the performance of HiChrome Candida agar. These strains had been identified by germ tube test, morphology on cornmeal agar, chlamydospore formation on tobacco agar and sugar assimilation tests. The sensitivity and specificity results were: C. albicans (96.55 and 96.42%); C. parapsilosis (80 and 98.03%), C. glabrata (90.90 and 88.23%), C. tropicalis (100 and 100%) and C. dubliniensis (60 and 96.55%) respectively. HiChrom Candida agaris medium has been useful and capable of presumptive, rapid identification of Candida species within 48 hours.

  14. Hichrom candida agar for identification of candida species

    Directory of Open Access Journals (Sweden)

    Baradkar V

    2010-01-01

    Full Text Available Chromogenic media are frequently used in direct and rapid identification of yeasts because different Candida species produce unique colors on these media. We used 60 isolates of Candida species including 30 C. albicans, 10 C. parapsilosis, 11 C. glabrata, five C. tropicalis, and four C. dubliniensis, isolated from various clinical specimens, to evaluate the performance of HiChrome Candida agar. These strains had been identified by germ tube test, morphology on cornmeal agar, chlamydospore formation on tobacco agar and sugar assimilation tests. The sensitivity and specificity results were: C. albicans (96.55 and 96.42%; C. parapsilosis (80 and 98.03%, C. glabrata (90.90 and 88.23%, C. tropicalis (100 and 100% and C. dubliniensis (60 and 96.55% respectively. HiChrom Candida agaris medium has been useful and capable of presumptive, rapid identification of Candida species within 48 hours.

  15. Assay for adhesion and agar invasion in S. cerevisiae.

    Science.gov (United States)

    Guldal, Cemile G; Broach, James

    2006-11-08

    Yeasts are found in natural biofilms, where many microorganisms colonize surfaces. In artificial environments, such as surfaces of man-made objects, biofilms can reduce industrial productivity, destroy structures, and threaten human life. 1-3 On the other hand, harnessing the power of biofilms can help clean the environment and generate sustainable energy. 4-8 The ability of S. cerevisiae to colonize surfaces and participate in complex biofilms was mostly ignored until the rediscovery of the differentiation programs triggered by various signaling pathways and environmental cues in this organism. 9, 10 The continuing interest in using S. cerevisiae as a model organism to understand the interaction and convergence of signaling pathways, such as the Ras-PKA, Kss1 MAPK, and Hog1 osmolarity pathways, quickly placed S. cerevisiae in the junction of biofilm biology and signal transduction research. 11-20 To this end, differentiation of yeast cells into long, adhesive, pseudohyphal filaments became a convenient readout for the activation of signal transduction pathways upon various environmental changes. However, filamentation is a complex collection of phenotypes, which makes assaying for it as if it were a simple phenotype misleading. In the past decade, several assays were successfully adopted from bacterial biofilm studies to yeast research, such as MAT formation assays to measure colony spread on soft agar and crystal violet staining to quantitatively measure cell-surface adherence. 12, 21 However, there has been some confusion in assays developed to qualitatively assess the adhesive and invasive phenotypes of yeast in agar. Here, we present a simple and reliable method for assessing the adhesive and invasive quality of yeast strains with easy-to-understand steps to isolate the adhesion assessment from invasion assessment. Our method, adopted from previous studies, 10, 16 involves growing cells in liquid media and plating on differential nutrient conditions for growth

  16. Preparation of Agar-Agar from the Red Seaweed Pterocladia capillacea off the Coast of Alexandria, Egypt.

    Science.gov (United States)

    Rao, A V; Bekheet, I A

    1976-10-01

    The effect of different treatments on the quality of agar produced from Pterocladia has been studied, and the conditions for the production of material of good quality have been standardized. In the modified process, sun-bleached seaweed was washed well in water, soaked for 24 h, and then ground to a pulp and rinsed again in water. The pulp was then extracted with water (weed-to-water ratio, 1:30) under pressure for 2 h after adjusting the pH to 6 by the addition of acetic acid. The agar gel, after freeze thawing, was bleached with NaClO before drying in a current of hot air. Pretreatment of the seaweed with alkali at 80 degrees C for 2 h prior to extraction was found to improve the quality of agar to a very great extent.

  17. Improved isolation of Vibro vulnificus from seawater and sediment with cellobiose-colistin agar

    DEFF Research Database (Denmark)

    Høi, L.; Dalsgaard, Inger; Dalsgaard, A.

    1998-01-01

    An improved selective medium, cellobiose-colistin (CC) agar, gave a significantly higher (P agar, In a total of 446 alkaline peptone water preenrichments amended...... with polymyxin B, V. vulnificus was isolated from 154 preenrichments (35%) with mCPC agar and from 179 preenrichments (40%) with CC agar. CC agar gave a higher plating efficiency of V. vulnificus cells than did cellobiose-polymyxin B-colistin (CPC) agar, mCPC agar, or thiosulfate-citrate-bile salts-sucrose (TCBS......) agar; the only significant difference was observed with TCBS agar, which gave much lower plating efficiencies than the other selective media. Determination of MICs demonstrated that the concentrations of colistin and polymyxin B in CPC agar inhibit growth of a proportion of V. vulnificus strains....

  18. Characterization of Gluten-free Bread Prepared From Maize, Rice and Tapioca Flours using the Hydrocolloid Seaweed Agar-Agar

    OpenAIRE

    Alvarenga, Nuno Bartolomeu; Cebola Lidon, Fernando; Belga, Elisa; Motrena, Patrícia; Guerreiro, Suse; Carvalho, Maria João; Canada, João

    2011-01-01

    Disponível em livre acesso no sítio do DOAJ em http://recent-science.com/index This work aims to check the rheological, physicochemical and sensory characteristics of gluten-free bread produced with corn, rice and tapioca flours, using the hydrocolloid seaweed agar-agar. Relatively to wheat bread, it was found that the pH was slightly lower in gluten-free bread. In the crust only the brightness remained significantly different between both bread types, but in the kernel, the parameters a*,...

  19. Corn and potato starch as an agar alternative for Solanum ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-01-04

    Jan 4, 2010 ... Media with 50, 60 g/l of PS or 60 g/l of CS and 50 g/l of CS + agar at 1 g/l significantly enhanced the ... Skoog (1962) medium supplemented 30 g/l of sucrose and 1 mg/l .... Arregui LM, Veramendi J, Mingo-Castel AM (2003).

  20. How selective are agar cultures for malignant transformation?

    NARCIS (Netherlands)

    Klein, J.C.

    1981-01-01

    In vitro assays that permit cloning of tumour cells in soft agar have been improved during the last 5 years. Two of them are claimed to be useful as test systems for the screening of new anticancer drugs and even for drug sensitivity testing of individual human tumours in devising individualized

  1. Growth of strontium oxalate crystals in agar–agar gel

    Indian Academy of Sciences (India)

    Growth of strontium oxalate crystals in agar–agar gel. P V DALAL. ∗ and K B SARAF. Postgraduate Department of Physics, Pratap College, Amalner 425 401, India. MS received 16 March 2008; revised 5 April 2010. Abstract. Single crystals of strontium oxalate have been grown by using strontium chloride and oxalic acid in.

  2. Development of a selective agar plate for the detection of Campylobacter spp. in fresh produce.

    Science.gov (United States)

    Yoo, Jin-Hee; Choi, Na-Young; Bae, Young-Min; Lee, Jung-Su; Lee, Sun-Young

    2014-10-17

    This study was conducted to develop a selective medium for the detection of Campylobacter spp. in fresh produce. Campylobacter spp. (n=4), non-Campylobacter (showing positive results on Campylobacter selective agar) strains (n=49) isolated from fresh produce, indicator bacteria (n=13), and spoilage bacteria isolated from fresh produce (n=15) were plated on four Campylobacter selective media. Bolton agar and modified charcoal cefoperazone deoxycholate agar (mCCDA) exhibited higher sensitivity for Campylobacter spp. than did Preston agar and Hunt agar, although certain non-Campylobacter strains isolated from fresh produce by using a selective agar isolation method, were still able to grow on Bolton agar and mCCDA. To inhibit the growth of non-Campylobacter strains, Bolton agar and mCCDA were supplemented with 5 antibiotics (rifampicin, polymyxin B, sodium metabisulfite, sodium pyruvate, ferrous sulfate) and the growth of Campylobacter spp. (n=7) and non-Campylobacter strains (n=44) was evaluated. Although Bolton agar supplemented with rifampicin (BR agar) exhibited a higher selectivity for Campylobacter spp. than did mCCDA supplemented with antibiotics, certain non-Campylobacter strains were still able to grow on BR agar (18.8%). When BR agar with various concentrations of sulfamethoxazole-trimethoprim were tested with Campylobacter spp. (n=8) and non-Campylobacter (n=7), sulfamethoxazole-trimethoprim was inhibitory against 3 of 7 non-Campylobacter strains. Finally, we validated the use of BR agar containing 50mg/L sulfamethoxazole (BRS agar) or 0.5mg/L ciprofloxacin (BRCS agar) and other selective agars for the detection of Campylobacter spp. in chicken and fresh produce. All chicken samples were positive for Campylobacter spp. when tested on mCCDA, BR agar, and BRS agar. In fresh produce samples, BRS agar exhibited the highest selectivity for Campylobacter spp., demonstrating its suitability for the detection of Campylobacter spp. in fresh produce. Copyright

  3. Enzymatic desulfation of the red seaweeds agar by Marinomonas arylsulfatase.

    Science.gov (United States)

    Wang, Xueyan; Duan, Delin; Fu, Xiaoting

    2016-12-01

    Agar and sulfated galactans were isolated from the red seaweeds Gracilariopsis lemaneiformis and Gelidium amansii. A previously purified arylsulfatase from Marinomonas sp. FW-1 was used to remove sulfate groups in agar and sulfated galactans. After enzymatic desulfation, the sulfate content decreased to about 0.16% and gel strength increased about two folds. Moreover, there was no difference between the DNA electrophoresis spectrum on the gel of the arylsulfatase-treated agar and that of the commercial agarose. In order to reveal the desulfation ratio and site, chemical and structural identification of sulfated galactan were carried out. G. amansii sulfated galactan with 7.4% sulfated content was composed of galactose and 3,6-anhydro-l-galactose. Meanwhile, G. lemaneiformis sulfated galactan with 8.5% sulfated content was composed of galactose, 3,6-anhydro-l-galactose, 2-O-methyl-3,6-anhydro-l-galactose and xylose. Data from 13 C NMR, FT-IR, GC-MS provided evidence of sulfate groups at C-4 and C-6 of d-galactose and C-6 of l-galactose both in GRAP and GEAP. Data from GC-MS revealed that desulfation was carried out by the arylsulfatase at the sulfate bonds at C-4 and C-6 of d-galactose and C-6 of l-galactose, with a desulfation ratio of 83.4% and 86.0% against GEAP and GRAP, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Use of electron beam on aflatoxins degradation in coconut agar

    International Nuclear Information System (INIS)

    Rogovschi, Vladimir D.; Nunes, Thaise C.F.; Villavicencio, Anna L.C.H.; Aquino, Simone; Goncalez, Edlayne; Correa, Benedito

    2009-01-01

    The fungi Aspergillus flavus are capable of producing toxic metabolites, such as aflatoxin, that is one of the most important human carcinogens, according to the 'International Agency for Research on Cancer'. The aim of this study was to compare the effect of electron beam irradiation on degradation of aflatoxin B1 present in laboratorial residues with a dose of 0 kGy and 5.0 kGy. The fungi were cultivated in potato dextrose agar (PDA) for 7 days and transferred to a coconut agar medium, incubated at a temperature of 25 deg C for 14 days to produce the laboratorial wastes (coconut agar) containing aflatoxins. The samples were conditioned in petri dish for radiation treatment of contaminated material and processed in the Electron Accelerator with 0 kGy and 5.0 kGy. Aflatoxin B 1 was extracted with chloroform and separated on a thin layer chromatography plate (TLC) with chloroform: acetone (9:1). All the control and irradiated samples were analyzed in a Shimadzu Densitometer. The detection limit of this methodology is 0.1μg kg -1 . The results indicate that the irradiated samples had a reduction of 75.49 % in the analyzed dose. (author)

  5. Recovery of Lactobacillus bulgaricus and Streptococcus thermophilus on Nine Commonly Used Agar Media1

    Science.gov (United States)

    Moon, Nancy J.; Hamann, A. C.; Reinbold, G. W.

    1974-01-01

    Of the nine media tested, Eugon, Elliker's lactic agar, pH 6.8, and modified tryptic soy broth agars showed superior recovery of Lactobacillus bulgaricus and Streptococcus thermophilus strains. PMID:16350006

  6. Speciation of Candida using chromogenic and cornmeal agar with determination of fluconazole sensitivity

    OpenAIRE

    Saroj Golia; K. Mallika Reddy; K. Sujatha Karjigi; Vivek Hittinahalli

    2013-01-01

    Objective and background: Candidiasis is an important cause of fungal infections. This study was carried out to determine the species incidence using chrom agar & cornmeal agar, susceptibility pattern to fluconazole by microbroth dilution methods of yeasts isolated from the clinical samples. Method: Positive samples for candidiasis where collected from 112 patients at Dr B R AMC from April 2010 to April 2011, processed by routine methods, chrom agar media and corn meal agar was used to spec...

  7. NMR spectroscopy study of agar-based polymers electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, R.I.; Tambelli, C.E. [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil). Fac. de Zootecnia e Engenharia de Alimentos; Raphael, E. [Universidade Federal de Sao Joao del-Rey (UFSJ), MG (Brazil). Dept. de Ciencias Naturais; Silva, I.D.A.; Magon, C.J.; Donoso, J.P. [Universidade de Sao Paulo (IFSC/USP), Sao Carlos, SP (Brazil). Inst. de Fisica

    2012-07-01

    Full text: This communication presents the results of preparation and characterization of transparent films obtained from agar and acetic acid. The films were characterized by electrochemical impedance spectroscopy (EIS) and nuclear magnetic resonance (NMR). The film formed by agar (Sigma Aldrich) was dispersed in water and kept under stirring and heating at 100 deg C. Next, glycerol, formaldehyde and different quantities of acetic acid (25 and 50 wt%) were added to this solution. The obtained solution was placed on a glass plate and left to dry for 48 hours in oven at 50 deg C to obtain the films, which were kept under vacuum before characterization. The ionic conductivity of the films display an Arrhenius behavior with activation energy E{sub a} = 78 (25 wt% of acetic acid) and E{sub a} = 87 kJ/mol (50 wt% of acetic acid). The conductivity values were 3:0 X 10{sup -6} and 1:2 X 10{sup -4} S/cm at room temperature and 4:4 X 10{sup -4} and 1:5 X 10{sup -3}S/cm at 70 deg C, for the 25 and 50 wt% of acetic acid respectively. To investigate the mechanism of protonic conduction in the polymer proton conductor proton NMR measurements were performed in the temperature range 200-370 K. The {sup 1}H-NMR results exhibit the qualitative feature associated with the proton mobility, namely the presence of well defined {sup 1}H spin-lattice relaxation maxima at 300 K. Activation energy of the order of 40 kJ/mol was obtained from the {sup 1}H-NMR line narrowing data. The ionic conductivity of the film combined with their transparency, flexibility, homogeneity and good adhesion to the glasses or metals indicate that agar-based SPEs are promising materials for used on optoelectronic applications. (author)

  8. Quantitative SIMS Imaging of Agar-Based Microbial Communities.

    Science.gov (United States)

    Dunham, Sage J B; Ellis, Joseph F; Baig, Nameera F; Morales-Soto, Nydia; Cao, Tianyuan; Shrout, Joshua D; Bohn, Paul W; Sweedler, Jonathan V

    2018-05-01

    After several decades of widespread use for mapping elemental ions and small molecular fragments in surface science, secondary ion mass spectrometry (SIMS) has emerged as a powerful analytical tool for molecular imaging in biology. Biomolecular SIMS imaging has primarily been used as a qualitative technique; although the distribution of a single analyte can be accurately determined, it is difficult to map the absolute quantity of a compound or even to compare the relative abundance of one molecular species to that of another. We describe a method for quantitative SIMS imaging of small molecules in agar-based microbial communities. The microbes are cultivated on a thin film of agar, dried under nitrogen, and imaged directly with SIMS. By use of optical microscopy, we show that the area of the agar is reduced by 26 ± 2% (standard deviation) during dehydration, but the overall biofilm morphology and analyte distribution are largely retained. We detail a quantitative imaging methodology, in which the ion intensity of each analyte is (1) normalized to an external quadratic regression curve, (2) corrected for isomeric interference, and (3) filtered for sample-specific noise and lower and upper limits of quantitation. The end result is a two-dimensional surface density image for each analyte. The sample preparation and quantitation methods are validated by quantitatively imaging four alkyl-quinolone and alkyl-quinoline N-oxide signaling molecules (including Pseudomonas quinolone signal) in Pseudomonas aeruginosa colony biofilms. We show that the relative surface densities of the target biomolecules are substantially different from values inferred through direct intensity comparison and that the developed methodologies can be used to quantitatively compare as many ions as there are available standards.

  9. The routine use of modified Borelli's lactritmel agar (MBLA).

    Science.gov (United States)

    Kaminski, G W

    1985-07-01

    The original formula of Borelli's lactritmel agar (BLA)(3) which contains wheat flour, milk and honey, has been modified by replacing the wheat flour with dehydrated Bacto Corn Meal Agar (Difco) and by slightly altering the concentrations of the milk and honey. The modified medium (MBLA) is less turbid, less particulate, and easier to prepare than BLA. Although Trichophyton rubrum usually produces a wine-red pigment with BLA, most strains initially produce a yellow pigment, with the red pigment developing later. The corn meal in MBLA reduces this tendency and stimulates the early formation of deep wine red pigment, MBLA enhances sporulation of dermatophytes and various fungi which fail to sporulate on other media, and maintains characteristic growth without developing pleomorphic degeneration. It has been used routinely since 1972 as a reliable aid to the differentiation of T. rubrum and T. mentagrophytes. Since 1975 selective MBLA has been used as a routine primary isolation medium for dermatophytes, and has proved to be most useful.

  10. Borelli's lactritmel agar induces conidiation in rare-macroconidia producing dermatophytic fungi.

    Science.gov (United States)

    Ilkit, Macit; Gümral, Ramazan; Döğen, Aylin

    2012-10-01

    Macroconidia are among the most important indicators used to identify dermatophytic fungi, but several do not usually sporulate and/or produce macroconidia on Sabouraud glucose agar. Specifically, Microsporum audouinii, M. ferrugineum, Trichophyton concentricum, T. schoenleinii, T. verrucosum, and T. violaceum (including T. soudanense and T. yaoundei) rarely form macroconidia and, therefore, cannot be easily identified. In this study, we investigated the production of macroconidia on nine common laboratory media, including Borelli's lactritmel agar (BLA), modified Borelli's lactritmel agar (MBLA), brain heart infusion agar (BHIA), Christensen's urease agar in Petri dishes (UPA), cornmeal dextrose agar (CMDA), Lowenstein-Jensen agar (LJA), malt extract agar (MEA), oatmeal agar (OA), and potato dextrose agar (PDA). The performance of these media was evaluated using 18 rare-macroconidia producing isolates, including representative of the six species mentioned above. All cultures in this study were incubated at 26°C on the bench, and conidia formation on each was investigated at 5, 10, 15, 20, 25, and 30 days of incubation. BLA apparently improved macroconidia production after 15 days and was the most useful nutrient agar medium to induce these phenotypic characters in daily practice, closely followed by OA, PDA, and MBLA.

  11. Element distribution of the barley plant grown in an agar slice suspended culture

    International Nuclear Information System (INIS)

    Makino-Nakanishi, Tomoko; Matsumoto, Satoshi

    1991-01-01

    An agar slice suspended culture was devised for the further study of the barley root. The roots were placed into an agar covered with a nylon cloth and suspended in a water culture vessel. Barley roots grown in the agar developed hardly any root hair. The element contents of the root grown in the agar culture and that in the water culture were measured by neutron activation analysis. The concentrations of K, Mg and Cl in the root grown in the agar were about half of these grown in the water. Na and Mn concentrations were the same and Ca concentration was slightly higher when grown in the agar. The agar system is expected to provide more information to study the root hair. (author)

  12. Comparative study of bio-ethanol production from mahula (Madhuca latifolia L.) flowers by Saccharomyces cerevisiae cells immobilized in agar agar and Ca-alginate matrices

    Energy Technology Data Exchange (ETDEWEB)

    Behera, Shuvashish; Mohanty, Rama Chandra [Department of Botany, Utkal University, Vani Vihar, Bhubaneswar 751004, Orissa (India); Kar, Shaktimay; Ray, Ramesh Chandra [Microbiology Laboratory, Central Tuber Crops Research Institute (Regional Centre), Bhubaneswar 751019, Orissa (India)

    2010-01-15

    Batch fermentation of mahula (Madhuca latifolia L., a tree commonly found in tropical rain forest) flowers was carried out using immobilized cells (in agar agar and calcium alginate) and free cells of Saccharomyces cerevisiae. The ethanol yields were 151.2, 154.5 and 149.1 g kg{sup -1} flowers using immobilized (in agar agar and calcium alginate) and free cells, respectively. Cell entrapment in calcium alginate was found to be marginally superior to those in agar agar (2.2% more) as well as over free cell (3.5% more) as regard to ethanol yield from mahula flowers is concerned. Further, the immobilized cells were physiologically active at least for three cycles [150.6, 148.5 and 146.5 g kg{sup -1} (agar agar) and 152.8, 151.5 and 149.5 g kg{sup -1} flowers (calcium alginate) for first, second and third cycle, respectively] of ethanol fermentation without apparently lowering the productivity. Mahula flowers, a renewable, non-food-grade cheap carbohydrate substrate from non-agricultural environment such as forest can serve as an alternative to food grade sugar/starchy crops such as maize, sugarcane for bio-ethanol production. (author)

  13. Calibration of the BASS acoustic current meter with carrageenan agar

    Science.gov (United States)

    Morrison, A.T.; Williams, A.J.; Martini, M.

    1993-01-01

    The BASS current meter can measure currents down to the millimeter per second range. Due to the dependence of zero offset on pressure, determining a sensor referenced velocity requires accurate in situ zeroing of the meter. Previously, flow was restricted during calibration by placing plastic bags around the acoustic volume. In this paper, bacterial grade and carrageenan agars are used in the laboratory to create a zero flow condition during calibration and are shown to be acoustically transparent. Additionally, the results of open ocean and dockside carrageenan and plastic bag comparisons are presented. Carrageenan is shown to reliably provide a low noise, zero mean flow environment that is largely independent of ambient conditions. The improved zeros make millimeter per second accuracy possible under field conditions.

  14. Comparison of different fungal agar for the environmental monitoring of pharmaceutical-grade cleanrooms.

    Science.gov (United States)

    Gebala, Barbara; Sandle, Tim

    2013-01-01

    In relation to a growth in reported incidents of fungal contamination of pharmaceutical products, there has been a developing interest by U.S. and U.K. regulators concerning the risk of fungi. This paper describes a study undertaken to examine the suitability of different commercially available mycological agars for the environmental monitoring of pharmaceutical-grade cleanrooms. Five agars were evaluated in relation to the detection of both numbers and different species of fungi (yeasts and moulds). The objective was to determine if one mycological medium is more suitable than another. Data was collected using different sampling techniques (settle plates, active air samples, and contact plates) from different locations within representative cleanrooms. Samples were taken over a 3 month time period. The study results indicated that fungi are not distributed evenly across cleanrooms and that that the prevalence of fungi partly relates to the room design and operation. In relation to the different agar types, the study indicated that Sabouraud dextrose agar was the most effective at detecting the widest number of different types of isolates, and that Sabouraud dextrose agar and malt extract agar were the most efficient in terms of the numbers of recovered isolates. Other media, notably potato dextrose agar, was relatively less effective. There has been an increased regulatory concern about the presence of fungi in cleanrooms. Some environmental monitoring regimes are not especially orientated towards the examination of fungi, and it may be that special agars are required. Given the choice of different agars available, this paper outlines a case study where different fungal agars were evaluated. The study showed that Sabouraud dextrose agar was the optimal agar.

  15. EVALUACIÓN POR MÉTODO ECOMÉTRICO DE AGAR OBTENIDO DE ALGAS ROJAS COLOMBIANAS

    Directory of Open Access Journals (Sweden)

    A. Villalobos

    2007-12-01

    Full Text Available The purpose of this study was to evaluate the productivity on agar-agar of two species of red algae of thegenera Gracilaria belonging from the Colombiam Caribean coast (G. cylindrica and G. mammillarisobtained in laboratory. Productivity of culture media elaborated with base agar - agar was determinedusing the ecometric method with 20 different bacterial species. Results obtained from ICA and ICRshowed that agar extracted from Gracilaria cylindrica and Gracillaria mammillaris are equally productive,this shows that both species can be used for agar production. For better results, it is still necessary tooptimize extraction processes and purification of agar in both species of algae.

  16. Screening agars for MRSA: evaluation of a stepwise diagnostic approach with two different selective agars for the screening for methicillin-resistant Staphylococcus aureus (MRSA).

    Science.gov (United States)

    Micheel, Volker; Hogan, Benedikt; Köller, Thomas; Warnke, Philipp; Crusius, Sabine; Hinz, Rebecca; Hagen, Ralf Matthias; Schwarz, Norbert Georg; Frickmann, Hagen

    2015-01-01

    Colonization with methicillin-resistant Staphylococcus aureus (MRSA) poses a hygiene risk that does not spare field hospitals or military medical field camps during military deployments. Diagnostic options for unambiguously identifying MRSA isolates are usually scarce in military environments. In this study, we assessed the stepwise application of two different selective agars for the specific identification of MRSA in screening analyses. Nasal swabs from 1541 volunteers were subjected to thioglycollate broth enrichment and subsequently screened on CHROMagar MRSA selective agar for the identification of MRSA. The MRSA identity of suspicious-looking colonies was confirmed afterwards or excluded by another selective agar, chromID MRSA. All isolates from the selective agars with MRSA-specific colony morphology were identified by biochemical methods and mass spectrometry. The initial CHROMagar MRSA screening identified suspicious colonies in 36 out of 1541 samples. A total of 25 of these 36 isolates showed MRSA-like growth on chromID agar. Out of these 25 isolates, 24 were confirmed as MRSA, while one isolate was identified as Staphylococcus kloosii. From the 11 strains that did not show suspicious growth on chromID agar, 3 were methicillin-sensitive Staphylococcus aureus (MSSA, with one instance of co-colonization with Corynebacterium spp.), 2 were confirmed as MRSA (with 1 instance of co-colonization with MSSA), 2 were lost during passaging and could not be re-cultured, one could not be identified by the applied approaches, and the remaining 3 strains were identified as Staphylococcus saprophyticus, Staphylococcus hominis (co-colonized with Macrococcus caseolyticus) and Staphylococcus cohnii, respectively. The application of the selective agar CHROMagar MRSA alone proved to be too non-specific to allow for a reliable diagnosis of the presence of MRSA. The combined use of two selective agars in a stepwise approach reduced this non-specificity with an acceptably low

  17. Agar dilution method for susceptibility testing of Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Marta C de Castillo

    1996-12-01

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

  18. Heavy metal accumulation by carrageenan and agar producing algae

    Energy Technology Data Exchange (ETDEWEB)

    Burdin, K.S. [Moscow State Univ. (Russian Federation). Faculty of Biology; Bird, K.T. [North Carolina Univ., Wilmington, NC (United States). Center for Marine Science Research

    1994-09-01

    The accumulation of six heavy metals Cu, Cd, Ni, Zn, Mn and Pb was measured in living and lzophilized algal thalli. The agar producing algae were Gracilaria tikvahiae and Gelidium pusillum. The carrageenan producing macroalgae were Agardhiella subulata and the gametophyte and tetrasporophyte phases of Chondrus crispus. These produce primarily iota, kappa and lambda carrageenans, respectively. At heavy metal concentrations of 0.5 mg L{sup -1}, living thalli of Gracilaria tikvahiae generally showed the greatest amount of accumulation of the 6 heavy metals tested. The accumulation of Pb was greater in the living thalli of all four species than in the lyophilized thalli. Except for Agardhiella subulata, lyophilized thalli showed greater accumulation of Ni, Cu and Zn. There was no difference in heavy metal accumulation between living and lyophilized thalli in the accumulation of Cd. Manganese showed no accumulation at the tested concentration. There did not appear to be a relationship between algal hydrocolloid characteristics and the amounts of heavy metals accumulated. (orig.)

  19. Genome sequence of the agar-degrading marine bacterium Alteromonadaceae sp. strain G7.

    Science.gov (United States)

    Kwak, Min-Jung; Song, Ju Yeon; Kim, Byung Kwon; Chi, Won-Jae; Kwon, Soon-Kyeong; Choi, Soobeom; Chang, Yong-Keun; Hong, Soon-Kwang; Kim, Jihyun F

    2012-12-01

    Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases.

  20. Genome Sequence of the Agar-Degrading Marine Bacterium Alteromonadaceae sp. Strain G7

    OpenAIRE

    Kwak, Min-Jung; Song, Ju Yeon; Kim, Byung Kwon; Chi, Won-Jae; Kwon, Soon-Kyeong; Choi, Soobeom; Chang, Yong-Keun; Hong, Soon-Kwang; Kim, Jihyun F.

    2012-01-01

    Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases.

  1. Pembuatan Bakto Agar dari Rumput Laut Gelidium rigidum untuk Media Tumbuh bagi Mikroorganisme

    Directory of Open Access Journals (Sweden)

    Murdinah murdinah

    2008-06-01

    Full Text Available ABSTRAK Telah dilakukan penelitian tentang pembuatan bakto agar dari rumput laut Gelidium rigidum untuk media tumbuh bagi mikroorganisme. Pembuatan bakto agar dilakukan dengan variasi waktu ekstraksi yaitu 1, 2, dan 3 jam pada suhu 121°C dan tekanan 1,1 atm. Bakto agar dianalisis rendemen dan mutunya yang meliputi kadar air, kadar abu, kadar abu tak larut asam, kadar sulfat, kekuatan gel, pH, titik leleh, dan titik jendal. Uji mikrobiologi yang diamati meliputi angka lempeng total bakteri (ALT dan diameter koloni. Dari hasil pengamatan diketahui bahwa bakto agar hasil ekstraksi dari rumput laut jenis Gelidium rigidum selama 2 jam mutunya menyamai bakto agar komersial, khususnya dari nilai kadar air, pH, kadar abu, kadar abu tak larut asam, kekuatan gel, serta kemampuannya menumbuhkan bakteri yang terdapat pada ikan segar dan kultur murni yaitu E. coli dan L. lactis. Tetapi dalam hal kadar sulfat, titik leleh, dan titik jendal masih di bawah mutu bakto agar komersial. Hasil penelitian juga menunjukkan bahwa waktu ekstraksi selama 2 jam menghasilkan bakto agar yang memenuhi standar bakto agar komersial dengan karakteristik kadar air 10,41%, kadar abu 2,1%, kadar abu tak larut asam 0,18%, kekuatan gel 670,72 g/cm2, dan pH 7,1.

  2. Development of novel agar media for isolating guaiacol producing Alicyclobacillus spp.

    Science.gov (United States)

    Chang, S S; Park, S H; Kang, D H

    2013-06-03

    The purpose of this study is to develop a selective and differential medium (SK2 agar) for isolating guaiacol producing Alicyclobacillus. Forty-one selected dyes and vanillic acid were incorporated in SK agar for screening selective and differential agents. Two guaiacol producing (1016, 1101) and two non-guaiacol producing (19220, C-GD 1-1) Alicyclobacillus isolates were streaked onto media and color differentiation of the isolates was assessed. Among 41 tested dyes, Chrome Azurol S (CAS) allowed color differentiation of the two types of Alicyclobacillus. Colonies of guaiacol producing Alicyclobacillus isolates appeared as dark purple to royal blue color with yellow background, whereas non-guaiacol producing Alicyclobacillus isolates produced cream colored colonies with yellow background. Vanillic acid not only served as a precursor for guaiacol formation but also inhibited non-guaiacol producing Alicyclobacillus. Non-guaiacol producing isolates did not grow on SK agar containing more than 70 ppm vanillic acid, whereas the recovery of guaiacol producing isolates was unaffected. When compared with other Alicyclobacillus isolation media, not only was SK2 agar capable of selectively recovering guaiacol-producing Alicyclobacillus, the degree of growth was also approximately equal if not better than orange serum agar, potato dextrose agar, and K agar. The development of SK2 agar provides the fruit juice industry with an inexpensive, simple to use alternative for the detection of guaiacol producing Alicyclobacillus. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Agar composition affects in vitro screening of biocontrol activity of antagonistic microorganisms

    NARCIS (Netherlands)

    Bosmans, Lien; De Bruijn, I.; de Mot, Rene; Readers, Hans; Lievens, Bart

    2016-01-01

    Agar-based screening assays are the method of choice when evaluating antagonistic potential of bacterial biocontrol-candidates against pathogens.Weshowed thatwhen using the samemedium, but different agar compositions, the activity of a bacterial antagonist against Agrobacteriumwas strongly affected.

  4. Current knowledge on agarolytic enzymes and the industrial potential of agar-derived sugars.

    Science.gov (United States)

    Yun, Eun Ju; Yu, Sora; Kim, Kyoung Heon

    2017-07-01

    Agar is a major cell wall carbohydrate of red macroalgae (Rhodophyta). Sugars derived from agar, such as agarooligosaccharides (AOSs), neoagarooligosaccharides (NAOSs), neoagarobiose (NAB), and 3,6-anhydro-L-galactose (L-AHG), possess various physiological activities. These agar-derived sugars can be produced by hydrolysis using chemicals or agarolytic enzymes. Despite the industrial potential of agar-derived sugars, their application has been hampered mainly due to the absence of efficient processes for the liquefaction and saccharification of agar. In this review, we have focused on strategies for producing high value-added sugars from agarose via chemical or enzymatic liquefaction and enzymatic saccharification. The liquefaction of agarose is a key step for preventing gelling and increasing the solubility of agarose in water by prehydrolyzing agarose into AOSs or NAOSs. For the industrial use of agar-derived sugars, AOS, NAOS, NAB, and L-AHG can be used as functional biomaterials owing to their physiological activities such as antiinflammation, skin whitening, and moisturizing. Recently, it was reported that AHG could be considered as a new anticariogenic sugar to replace xylitol. This review provides a comprehensive overview of processes for the hydrolysis of agar or agarose to produce high value-added sugars and the industrial application of these sugars.

  5. AGAR FROM MALAYSIAN RED SEAWEED AS POTENTIAL MATERIAL FOR SYNTHESIS OF BIOPLASTIC FILM

    Directory of Open Access Journals (Sweden)

    SIEW-LING HII

    2016-07-01

    Full Text Available The main aim of this study was to identify the potential use of agar extracted from red seaweed, Gracilaria salicornia, collected from the coastal area of Malaysia as the raw material for synthesis of bioplastic film. Agar was extracted via two extraction methods: (1 alkali extraction method and (2 photo bleaching extraction method. The yields of agar by both of the methods were 9 to 11 %. The alkali extracted agar (AEA and photo bleached agar (PBA were incorporated as the raw materials for the formation of bioplastic films while sago starch and glycerol were added to increase workability. Physicochemical properties of the two bioplastic films were characterised. FTIR analysis confirmed the presence of agar in both plastic films with the presence of 3,6- anhydrogalactose residues and further indicated that the interactions of agar and sago starch were strong in both PBA and AEA films. The results showed that tensile strength and percent elongation of PBA film (3.067 MPa, 3.270 % was higher than AEA film (2.431 MPa, 2.476 %. Thermogravimetric analysis (TGA; % residual weight revealed that AEA film has higher thermal stability (14.80 % than PBA film (10.27 % while rheological results proved that both films exhibited non-Newtonian behaviors. The AEA film was completely decomposed after 30 days in the soil burial test. Results of current study show a wide range of future possibilities and commercial applications of AEA and PBA bioplastic films.

  6. Modeling of the Bacillus subtilis Bacterial Biofilm Growing on an Agar Substrate.

    Science.gov (United States)

    Wang, Xiaoling; Wang, Guoqing; Hao, Mudong

    2015-01-01

    Bacterial biofilms are organized communities composed of millions of microorganisms that accumulate on almost any kinds of surfaces. In this paper, a biofilm growth model on an agar substrate is developed based on mass conservation principles, Fick's first law, and Monod's kinetic reaction, by considering nutrient diffusion between biofilm and agar substrate. Our results show biofilm growth evolution characteristics such as biofilm thickness, active biomass, and nutrient concentration in the agar substrate. We quantitatively obtain biofilm growth dependence on different parameters. We provide an alternative mathematical method to describe other kinds of biofilm growth such as multiple bacterial species biofilm and also biofilm growth on various complex substrates.

  7. Green fabrication of agar-conjugated Fe{sub 3}O{sub 4} magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, S; Huang, B Y; Lin, P Y; Chang, C W [Department of Chemistry and Center for Nanoscience and Nanotechnology, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Hsieh, S L [Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung 81157, Taiwan (China); Wu, C C [Department of Nutrition and Health Sciences, Chang Jung Christian University, Tainan 71101, Taiwan (China); Wu, C H [Department of Computer Science and Information Engineering, National University of Kaohsiung, Kaohsiung 80811, Taiwan (China); Huang, Y S, E-mail: shsieh@facmail.NSYSU.edu.tw [Department of Food Science and Technology, Tajen University, Pingtung 90741, Taiwan (China)

    2010-11-05

    Magnetic nanoparticles are of great interest both for fundamental research and emerging applications. In the biomedical field, magnetite (Fe{sub 3}O{sub 4}) has shown promise as a hyperthermia-based tumor therapeutic. However, preparing suitable solubilized magnetite nanoparticles is challenging, primarily due to aggregation and poor biocompatibility. Thus methods for coating Fe{sub 3}O{sub 4} NPs with biocompatible stabilizers are required. We report a new method for preparing Fe{sub 3}O{sub 4} nanoparticles by co-precipitation within the pores of agar gel samples. Permeated agar gels were then dried and ground into a powder, yielding agar-conjugated Fe{sub 3}O{sub 4} nanoparticles. Samples were characterized using XRD, FTIR, TGA, TEM and SQUID. This method for preparing agar-coated Fe{sub 3}O{sub 4} nanoparticles is environmentally friendly, inexpensive and scalable.

  8. Low density, microcellular, dopable, agar/gelatin foams for pulsed power experiments

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, W.F. [Orion International Technologies, Inc., Albuquerque, NM (United States); Aubert, J.H. [Sandia National Lab., Albuquerque, NM (United States)

    1997-04-01

    Low-density, microcellular foams prepared from the natural polymers agar and gelatin have been developed for pulsed-power physics experiments. Numerous experiments were supported with foams having densities at or below 10 mg/cm{sup 3}. For some of the experiments, the agar/gelatin foam was uniformly doped with metallic elements using soluble salts. Depending on the method of preparation, cell sizes were typically below 10 microns and for one process were below 1.0 micron.

  9. A radiobiological comparison of human tumor soft-agar clonogenic assays.

    Science.gov (United States)

    West, C M; Sutherland, R M

    1986-06-15

    Radiation survival curves have been generated for 3 human tumor cell lines as a means of comparing and evaluating the validity of human tumor soft-agar clonogenic assays. The assays investigated were the Hamburger-Salmon, Courtenay-Mills, Courtenay-Mills plus additions, soft agar (no additions), and soft agar plus additions. The additions were formulated to supplement the media used in soft agar assays of primary ovarian and cervical carcinoma specimens. Supplementing the media with additions led to a 2- to 3-fold increase in PE of CaSki cells but had no effect on the PEs of ME180 and OWI cells. Radiation survival curves were similar in all assays for CaSki and OWI but differed for ME180 cells. For ME180 cells, the Courtenay-Mills and soft agar assays plus additions produced the most radioresistant curves (Do = 2.2 Gy); the cells were more responsive when assayed by the Hamburger-Salmon method (Do = 1.5 Gy), and the soft agar and Courtenay-Mills assays gave the most radiosensitive curves (Do = 1.2 Gy). These results demonstrate that the PE of human tumor cell lines may be increased with no effect on radiation survival; radiation survival may be altered without changes in PE and neither may be altered by applying modifications and supplements to existing clonogenic assays.

  10. Effect of Red Seaweed Polysaccharides Agar (Gracilaria changii) on Thermal Properties and Microstructure of Wheat Starch

    International Nuclear Information System (INIS)

    Faizal, P.K.

    2009-01-01

    This study has been carried out on the mixture of Gracilaria changii agar (0.1 %, 0.2 %, 0.4 % and 0.8 %) with wheat starch. Scanning electron microscopy (SEM) was performed for morphology observation, and starch thermal analysis were carried out to determine the properties of gelatinization and retrogradation. Proximate analysis has been determined for isolated wheat starch and agar. Through SEM, interaction was first observed at 64 degree Celsius for 0.4 % agar but at 0.8 % of agar, a more extensive bridging was formed which enveloped the starch granules. Differential scanning calorimetric (DSC) result shows that as the addition of agar decreased the onset temperature (T o ) of gelatinization significantly (p< 0.05) but increased the gelatinized enthalpy (ΔH gel ), gelatinized temperature range (R g ) and Peak Height Index (PHI) significantly (p < 0.05). Agar lowered the retrogradation enthalpy (ΔH ret ), retrogradation range (R ret ) and retrogradation percentage (% R) of wheat starch significantly (p < 0.05). (author)

  11. Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species

    Directory of Open Access Journals (Sweden)

    Marol Serhat

    2003-10-01

    Full Text Available Abstract Background The importance of identifying the pathogenic fungi rapidly has encouraged the development of differential media for the presumptive identification of yeasts. In this study two differential media, CHROMagar Candida and bismuth sulphite glucose glycine yeast agar, were evaluated for the presumptive identification of yeast species. Methods A total number of 270 yeast strains including 169 Candida albicans, 33 C. tropicalis, 24 C. glabrata, 18 C. parapsilosis, 12 C. krusei, 5 Trichosporon spp., 4 C. kefyr, 2 C. lusitaniae, 1 Saccharomyces cerevisiae and 1 Geotrichum candidum were included. The strains were first identified by germ tube test, morphological characteristics on cornmeal tween 80 agar and Vitek 32 and API 20 C AUX systems. In parallel, they were also streaked onto CHROMagar Candida and bismuth sulphite glucose glycine yeast agar plates. The results were read according to the color, morphology of the colonies and the existance of halo around them after 48 hours of incubation at 37°C. Results The sensitivity and specificity values for C. albicans strains were found to be 99.4, 100% for CHROMagar Candida and 87.0, 75.2% for BiGGY agar, respectively. The sensitivity of CHROMagar Candida to identify C. tropicalis, C. glabrata and C. krusei ranged between 90.9 and 100% while the specificity was 100%. The sensitivity rates for BiGGY agar were 66.6 and 100% while the specificity values were found to be 95.4 and 100% for C. tropicalis and C. krusei, respectively. Conclusions It can be concluded that the use of CHROMagar Candida is an easy and reliable method for the presumptive identification of most commonly isolated Candida species especially C. albicans, C. tropicalis and C. krusei. The lower sensitivity and specificity of BiGGY agar to identify commonly isolated Candida species potentially limits the clinical usefulness of this agar.

  12. Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species.

    Science.gov (United States)

    Yücesoy, Mine; Marol, Serhat

    2003-10-29

    The importance of identifying the pathogenic fungi rapidly has encouraged the development of differential media for the presumptive identification of yeasts. In this study two differential media, CHROMagar Candida and bismuth sulphite glucose glycine yeast agar, were evaluated for the presumptive identification of yeast species. A total number of 270 yeast strains including 169 Candida albicans, 33 C. tropicalis, 24 C. glabrata, 18 C. parapsilosis, 12 C. krusei, 5 Trichosporon spp., 4 C. kefyr, 2 C. lusitaniae, 1 Saccharomyces cerevisiae and 1 Geotrichum candidum were included. The strains were first identified by germ tube test, morphological characteristics on cornmeal tween 80 agar and Vitek 32 and API 20 C AUX systems. In parallel, they were also streaked onto CHROMagar Candida and bismuth sulphite glucose glycine yeast agar plates. The results were read according to the color, morphology of the colonies and the existance of halo around them after 48 hours of incubation at 37 degrees C. The sensitivity and specificity values for C. albicans strains were found to be 99.4, 100% for CHROMagar Candida and 87.0, 75.2% for BiGGY agar, respectively. The sensitivity of CHROMagar Candida to identify C. tropicalis, C. glabrata and C. krusei ranged between 90.9 and 100% while the specificity was 100%. The sensitivity rates for BiGGY agar were 66.6 and 100% while the specificity values were found to be 95.4 and 100% for C. tropicalis and C. krusei, respectively. It can be concluded that the use of CHROMagar Candida is an easy and reliable method for the presumptive identification of most commonly isolated Candida species especially C. albicans, C. tropicalis and C. krusei. The lower sensitivity and specificity of BiGGY agar to identify commonly isolated Candida species potentially limits the clinical usefulness of this agar.

  13. Formulation of Hydrocolloid-Agar, Sucrose, and Acidulant on Jam Leather Product Development

    Directory of Open Access Journals (Sweden)

    Wahyu Ramadhan

    2017-04-01

    Full Text Available Tallying agar powder as a texturizer in guava single sheet jam instigate the product more convenience to consumed. The aims of this research were to determine the best concentration of sucrose, citric acid and agar powder to form a good quality guava jam slice. The research method are optimization and formulationof sucrose, citric acid and agar-agar on making guava jam single sheets product. Physochemical and sensory tests were performed to reveal the best formulation of guava jam slice and the Bayes method used to determine the optimization of the selected formula. Based on the results of formulation and analysis, itwas obtained that  the guava jam slice with Acidulant concentration (0.02%, 0.04%, 0.06%, sucrose (70%, 80%, 90%, 100% and agar powder (0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2% had pH 3.63-3.90, sugar content 34.68 g/100 g – 35.76 g/100 g, color intensity L*, a*, b* with ΔE* value was 37,88-53,97, fiber content 1.01%-1.59%, and water activity 0.852-0.893. Rheology properties for texture profile (hardness, cohesiveness, springiness, adhesive force, and gumminess also showed significant value with agar powder formulation. Based on the Bayes test and hedonic test, it was found that the best formula was for guava jam slices with the addition of 90% sucrose, citric acid 0.04% and agar powder 0.9%. From the best formula, it was found the shelf life prediction model of Arrhenius formula was ln k = 20.222-6660.6(1/T and the nutrition facts contribute total energy 45 kcal, fat 0%, carbohydrate 9%, protein 2% and dietary fiber 3%.

  14. Comparison of selective agars recommended by method ISO 11290-1 and chromogenic agars for the isolation of Listeria sp. in refrigerated sausages

    Directory of Open Access Journals (Sweden)

    Thalyta Marina Benetti

    2012-12-01

    Full Text Available The aim of this study was to determine the prevalence of Listeria sp. in refrigerated sausages, and to compare the performance of the selective plating media employed in the ISO 11290-1 method (PALCAM and Oxford agars with chromogenic agars (Chromogenic Listeria agars CM 1080 (OCLA and CM 1084. The prevalence of Listeria sp. detected was 52.9%, comprising 13.7% L. monocytogenes strains. The efficacy of the four agars for the isolation of L. monocytogenes proved to be satisfactory. Despite differences in composition of the chromogenic media assessed, these disparities did not affect concordance among results. However, PALCAM agar was shown to suppress other microorganisms more effectively, being more applicable for detecting Listeria strains present in lower quantities. Based on these results, the use of PALCAM agar, in combination with a chromogenic media, is recommended for enhanced isolation of atypical Listeria sp. strains in meat products.Este estudo teve como objetivo a análise da prevalência de Listeria sp. em linguiças resfriadas e a comparação dos meios seletivos utilizados no plaqueamento do método ISO 11290-1 (Ágar PALCAM e Ágar Oxford, e ágares cromogênicos (Ágares Listeria Cromogênico CM 1080 (OCLA e CM 1084 (ISO. A frequência de Listeria sp. foi de 52,9%, sendo que destas, 13,7% corresponderam à L. monocytogenes. A eficácia dos quatro ágares para o isolamento de L. monocytogenes demonstrou-se satisfatória. Apesar de haver algumas diferenças nas composições dos meios cromogênicos analisados, estas não pareceram influenciar nas concordâncias entre os resultados expressos. Contudo, o ágar PALCAM mostrou-se mais eficaz na supressão de outros micro-organismos, aumentando, assim, a possibilidade de detecção de espécies de Listeria presentes em número reduzido. Através deste trabalho sugere-se a utilização do ágar PALCAM associado a um meio cromogênico para aumentar a chance de isolamento de cepas at

  15. Effects of shape and size of agar gels on heating uniformity during pulsed microwave treatment.

    Science.gov (United States)

    Soto-Reyes, Nohemí; Temis-Pérez, Ana L; López-Malo, Aurelio; Rojas-Laguna, Roberto; Sosa-Morales, María Elena

    2015-05-01

    Model gel systems with different shape (sphere, cylinder, and slab) and size (180 and 290 g) were prepared with agar (5%) and sucrose (5%). Dielectric constant (ε'), loss factor (ε"), thermophysical properties, and temperature distribution of the model system were measured. Each agar model system was immersed and suspended in water, and then, heated in a microwave oven with intermittent heating until the core temperature reached 50 °C. The ε' and ε" of agar gels decreased when frequency increased. The density and thermal conductivity values of the agar gels were 1033 kg/m(3) and 0.55 W/m °C, respectively. The temperature distribution of sphere, cylinder, and slab was different when similar power doses were applied. The slab reached 50 °C in less time (10 min) and showed a more uniform heating than spheres and cylinders in both sizes. Agar model systems of 180 g heated faster than those of 290 g. The coldest point was the center of the model systems in all studied cases. Shape and size are critical food factors that affect the heating uniformity during microwave heating processes. © 2015 Institute of Food Technologists®

  16. Antimicrobial and physical-mechanical properties of agar-based films incorporated with grapefruit seed extract.

    Science.gov (United States)

    Kanmani, Paulraj; Rhim, Jong-Whan

    2014-02-15

    The use of synthetic petroleum based packaging films caused serious environmental problems due to their difficulty in recycling and poor biodegradability. Therefore, present study was aimed to develop natural biopolymer-based antimicrobial packaging films as an alternative for the synthetic packaging films. As a natural antimicrobial agent, grapefruit seed extract (GSE) has been incorporated into agar to prepare antimicrobial packaging film. The films with different concentrations of GSE were prepared by a solvent casting method and the resulting composite films were examined physically and mechanically. In addition, the films were characterized by FE-SEM, XRD, FT-IR and TGA. The incorporation of GSE caused increase in color, UV barrier, moisture content, water solubility and water vapor permeability, while decrease in surface hydrophobicity, tensile strength and elastic modulus of the films. As the concentration of GSE increased from 0.6 to 13.3 μg/mL, the physical and mechanical properties of the films were affected significantly. The addition of GSE changed film microstructure of the film, but did not influence the crystallinity of agar and thermal stability of the agar-based films. The agar/GSE films exhibited distinctive antimicrobial activity against three test food pathogens, such as Listeria monocytogenes, Bacillus cereus and Escherichia coli. These results suggest that agar/GSE films have potential to be used in an active food packaging systems for maintaining food safety and extending the shelf-life of the packaged food. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Strategies to improve the mechanical strength and water resistance of agar films for food packaging applications.

    Science.gov (United States)

    Sousa, Ana M M; Gonçalves, Maria P

    2015-11-05

    Agar films possess several properties adequate for food packaging applications. However, their high cost-production and quality variations caused by physiological and environmental factors affecting wild seaweeds make them less attractive for industries. In this work, native (NA) and alkali-modified (AA) agars obtained from sustainably grown seaweeds (integrated multi-trophic aquaculture) were mixed with locust bean gum (LBG) to make 'knife-coated' films with fixed final concentration (1 wt%) and variable agar/LBG ratios. Agar films were easier to process upon LBG addition (viscosity increase and gelling character decrease of the film-forming solutions observed by dynamic oscillatory and steady shear measurements). The mechanical properties and water resistance were optimal for films with 50 and/or 75% LBG contents and best in the case of NA (cheaper to extract). These findings can help reduce the cost-production of agar packaging films. Moreover, the controlled cultivation of seaweeds can provide continuous and reliable feedstock for transformation industries. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Time domain NMR study of Agar-gelatin blends; Estudo por RMN no dominio do tempo de blendas de Agar- gelatina

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Ritamara; Pericini, H.A.; Tambelli, Caio E., E-mail: tambelli@usp.br [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos; Raphael, Ellen [Universidade Federal de Sao Joao del Rei (UFSJ), MG (Brazil). Departamento de Ciencias Naturais; Magon, Claudio J.; Donoso, P. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Instituto de Fisica

    2015-07-01

    This communication presents results of {sup 1}H time domain nuclear magnetic resonance of Agar-Gelatin blends plasticised with glycerol, cross-linked with formaldehyde and containing acetic acid. The spin-spin relaxation decay curves of samples obtained from CPMG experiments were inverted into corresponding distributions of relaxation times using NNLS (Non Negative Least Square) algorithm. The continuous distributions reveals up to four components of spin-spin relaxation times (T{sub 2}). The two components at short T{sub 2} were associated with protons in different environments of Agar and gelatin polymer chain. The two components at longer T{sub 2} can be associated with the glycerol that is the responsible to promote the proton conduction in the blend. (author)

  19. Evaluation of modified dichloran 18% glycerol (DG18) agar for enumerating fungi in wheat flour: a collaborative study.

    Science.gov (United States)

    Beuchat, L R; Hwang, C A

    1996-04-01

    Dichloran 18% glycerol agar base supplemented with 100 micrograms of chloramphenicol ml-1 (DG18 agar) was compared to DG18 agar supplemented with 100 micrograms of Triton X-301 ml-1 (DG18T) and DG18 agar supplemented with 1 microgram of iprodione [3-(3,5-dichlorophenyl)-N-(1-methyl-ethyl)-2,4-dioxo-1-imidazolidine- carboxamide] ml-1 (DG18I agar) for enumeration of fungi in ten brands of wheat flour. As the flours contained low fungal populations, all were inoculated with two to four strains of xerophilic fungi (Aspergillus candidus, A. penicillioides, Eurotium amstelodami, E. intermedium, E. repens, E. rubrum, E. tonophilum, E. umbrosum and Wallemia sebi), after which counts ranged from 3.87 to 6.37 log10 CFU g-1. Significantly higher populations (p repens or E. tonophilum had also been inoculated into at least one of the three flours showing significantly higher numbers of CFU on DG18T agar. Analysis of collapsed data from all samples showed that DG18T agar was significantly better than DG18 or DG18I agars at p < 0.10 but not at p < 0.05. Coefficients of variation for reproducibility (among-laboratory variation) were 8.4%, 7.5% and 8.6%, respectively, for DG18, DG18T and DG18I agars. DG18I agar restricted colony development most, especially for Eurotium species. Naturally occurring Penicillium species grew equally well on DG18 and DG18T agars, whereas W. sebi grew well on all three media. DG18T agar was judged to be superior to DG18 and DG18I agars for enumerating fungi in wheat flours.

  20. Effects of disinfection of combined agar/alginate impressions on the dimensional accuracy of stone casts.

    Science.gov (United States)

    Hiraguchi, Hisako; Nakagawa, Hisami; Kaketani, Masahiro; Hirose, Hideharu; Nishiyama, Minoru

    2007-05-01

    This study investigated the effects of disinfection of combined agar/alginate impressions on the dimensional accuracy of resultant stone casts. Impressions of a master cast designed to simulate an abutment tooth were prepared by combining each of two brands of cartridge-form agar impression materials with an alginate impression material. The impressions were immersed in 1% sodium hypochlorite for 10 minutes or 2% glutaraldehyde for 30 minutes. The remaining impressions were sprayed with these two disinfectants and then stored in sealed bags for 10, 30, 60, and 120 minutes. Stone casts obtained from the non-disinfected impressions were also prepared as control. Changes in diameter of the stone casts were then measured. Results indicated that storage for 10 minutes after spraying with 1% sodium hypochlorite was an appropriate disinfection method for combined agar/alginate impressions, as well as immersion in 1% sodium hypochlorite for 10 minutes.

  1. Modeling of the Bacillus subtilis Bacterial Biofilm Growing on an Agar Substrate

    Directory of Open Access Journals (Sweden)

    Xiaoling Wang

    2015-01-01

    Full Text Available Bacterial biofilms are organized communities composed of millions of microorganisms that accumulate on almost any kinds of surfaces. In this paper, a biofilm growth model on an agar substrate is developed based on mass conservation principles, Fick’s first law, and Monod’s kinetic reaction, by considering nutrient diffusion between biofilm and agar substrate. Our results show biofilm growth evolution characteristics such as biofilm thickness, active biomass, and nutrient concentration in the agar substrate. We quantitatively obtain biofilm growth dependence on different parameters. We provide an alternative mathematical method to describe other kinds of biofilm growth such as multiple bacterial species biofilm and also biofilm growth on various complex substrates.

  2. Influence of agar concentration on in vitro multiplication of Cymbopogon citratus (D. C. Stapf

    Directory of Open Access Journals (Sweden)

    Ricardo J. Licea Moreno

    2001-04-01

    Full Text Available Here are presented the results on in vitro multiplication of lemon grass (Cymbopogon citratus (D. C. Stapf.; it is a very important medicinal plant because its analgesic, antinflamatory and hipotensor properties, among others, useful to elaborate several medicaments with a high popular acceptation. The main aim of this research was to set up the influence of agar concentration in culture medium during in vitro establishment on multiplication of lemon grass. Were used three treatments: (1 liquid medium with filter paper bridges, (2 3 g.l-1 of agar (BIOCEN and (3 6 g.l-1 of agar (BIOCEN. The explants were inoculated on a culture media containing Murashige and Skoog salts (1962, Heinz and Mee vitamins (1969, myoinositol 100 mg.l-1, 6-BAP 0.2 mg.l-1 and sucrose 20 g.l-1. Meristematic tips were inoculated on the treatments described above under sun light conditions, once desinfected. The explants Influence of agar concentration on in vitro multiplication of Cymbopogon citratus (D. C. Stapf. were maintained 21 days in this culture media and later it is were subcultured 5 times each 21 days, on the same multiplication culture media containing Murashige and Skoog salts (1962, tiamine 1 mg.l-1, myoinositol 100 mg.l-1, 6-BAP 0.3 mg.l-1 and sucrose 30 g.l-1. The pH was 5.7 for all culture media. The results showed the relevance of agar concentration during in vitro establishment on multiplication of lemon grass. Differences among treatments until the 2nd subculture was observed. 3.43 new axillary shoots from each explant cultured on a culture media supplemented with 3 g.l-1 of agar was reached. Key words: lemon grass, medicinal plants, micropropagation, tissue culture

  3. Radiation effects on agar, alginates and carrageenan to be used as food additives

    International Nuclear Information System (INIS)

    Aliste, A.J.; Vieira, F.F.; Mastro, N.L. del

    2000-01-01

    Agar, alginates and carrageenan are hydrocolloids that induce stabilization of physical properties of the food product during shelf life and prevention of undesirable changes such as moisture migration, gas cell coalescence or textural profile changes. In this work, agar, alginates and carrageenan was irradiated as powder with different doses (0-10 kGy) of Co-60 and the rheological functional performance of water solutions of these irradiated additives was studied. The results are analyzed taking in account the future applications of those additives in irradiated foods. (author)

  4. Radiation effects on agar, alginates and carrageenan to be used as food additives

    Energy Technology Data Exchange (ETDEWEB)

    Aliste, A.J. E-mail: nlmastro@net.ipen.br; Vieira, F.F.; Mastro, N.L. del

    2000-03-01

    Agar, alginates and carrageenan are hydrocolloids that induce stabilization of physical properties of the food product during shelf life and prevention of undesirable changes such as moisture migration, gas cell coalescence or textural profile changes. In this work, agar, alginates and carrageenan was irradiated as powder with different doses (0-10 kGy) of Co-60 and the rheological functional performance of water solutions of these irradiated additives was studied. The results are analyzed taking in account the future applications of those additives in irradiated foods. (author)

  5. Formation of Ramified Colony of Fungus Aspergillus Oryzae on Agar Media

    Science.gov (United States)

    Matsuura, Shu; Miyazima, Sasuke

    Ramified colonies of fungus Aspergillus oryzae have been found to grow at a low growth rate on "liquid-like" agar media with low concentrations of agar and glucose. Box-counting fractal dimensions of the individual colony branches have been found to decrease with the time of incubation. Addition of glucose solution in the interior of branched colonies has brought about the production of the hyphal filaments almost only at the apical region of the colony branches. Active growth of the ramified colonies is localized in the peripheral zone, and this growth manner implies that the fungus is exhibiting a positive exploitation.

  6. Comparison of Sabouraud dextrose and Pagano-Levin agar media for detection and isolation of yeasts from oral samples.

    OpenAIRE

    Samaranayake, L P; MacFarlane, T W; Williamson, M I

    1987-01-01

    The sensitivities of Sabouraud dextrose agar and modified Pagano-Levin agar for the primary isolation of yeasts and the recovery of multiple yeast species from single clinical samples were compared by using oral-rinse samples. Although there was a highly significant positive correlation between the numbers of yeasts recovered from both media, modified Pagano-Levin agar was far superior in detecting multiple yeast species in a single sample. Of 150 oral samples containing yeasts, 23 (15.3%) co...

  7. Comparison of the Cellient(™) automated cell block system and agar cell block method.

    Science.gov (United States)

    Kruger, A M; Stevens, M W; Kerley, K J; Carter, C D

    2014-12-01

    To compare the Cellient(TM) automated cell block system with the agar cell block method in terms of quantity and quality of diagnostic material and morphological, histochemical and immunocytochemical features. Cell blocks were prepared from 100 effusion samples using the agar method and Cellient system, and routinely sectioned and stained for haematoxylin and eosin and periodic acid-Schiff with diastase (PASD). A preliminary immunocytochemical study was performed on selected cases (27/100 cases). Sections were evaluated using a three-point grading system to compare a set of morphological parameters. Statistical analysis was performed using Fisher's exact test. Parameters assessing cellularity, presence of single cells and definition of nuclear membrane, nucleoli, chromatin and cytoplasm showed a statistically significant improvement on Cellient cell blocks compared with agar cell blocks (P cell groups, PASD staining or the intensity or clarity of immunocytochemical staining. A discrepant immunocytochemistry (ICC) result was seen in 21% (13/63) of immunostains. The Cellient technique is comparable with the agar method, with statistically significant results achieved for important morphological features. It demonstrates potential as an alternative cell block preparation method which is relevant for the rapid processing of fine needle aspiration samples, malignant effusions and low-cellularity specimens, where optimal cell morphology and architecture are essential. Further investigation is required to optimize immunocytochemical staining using the Cellient method. © 2014 John Wiley & Sons Ltd.

  8. Hyperspectral image reconstruction using RGB color for foodborne pathogen detection on agar plates

    Science.gov (United States)

    Yoon, Seung-Chul; Shin, Tae-Sung; Park, Bosoon; Lawrence, Kurt C.; Heitschmidt, Gerald W.

    2014-03-01

    This paper reports the latest development of a color vision technique for detecting colonies of foodborne pathogens grown on agar plates with a hyperspectral image classification model that was developed using full hyperspectral data. The hyperspectral classification model depended on reflectance spectra measured in the visible and near-infrared spectral range from 400 and 1,000 nm (473 narrow spectral bands). Multivariate regression methods were used to estimate and predict hyperspectral data from RGB color values. The six representative non-O157 Shiga-toxin producing Eschetichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145) were grown on Rainbow agar plates. A line-scan pushbroom hyperspectral image sensor was used to scan 36 agar plates grown with pure STEC colonies at each plate. The 36 hyperspectral images of the agar plates were divided in half to create training and test sets. The mean Rsquared value for hyperspectral image estimation was about 0.98 in the spectral range between 400 and 700 nm for linear, quadratic and cubic polynomial regression models and the detection accuracy of the hyperspectral image classification model with the principal component analysis and k-nearest neighbors for the test set was up to 92% (99% with the original hyperspectral images). Thus, the results of the study suggested that color-based detection may be viable as a multispectral imaging solution without much loss of prediction accuracy compared to hyperspectral imaging.

  9. Investigation of dental alginate and agar impression materials as a brain simulant for ballistic testing.

    Science.gov (United States)

    Falland-Cheung, Lisa; Piccione, Neil; Zhao, Tianqi; Lazarjan, Milad Soltanipour; Hanlin, Suzanne; Jermy, Mark; Waddell, J Neil

    2016-06-01

    Routine forensic research into in vitro skin/skull/brain ballistic blood backspatter behavior has traditionally used gelatin at a 1:10 Water:Powder (W:P) ratio by volume as a brain simulant. A limitation of gelatin is its high elasticity compared to brain tissue. Therefore this study investigated the use of dental alginate and agar impression materials as a brain simulant for ballistic testing. Fresh deer brain, alginate (W:P ratio 91.5:8.5) and agar (W:P ratio 81:19) specimens (n=10) (11×22×33mm) were placed in transparent Perspex boxes of the same internal dimensions prior to shooting with a 0.22inch caliber high velocity air gun. Quantitative analysis to establish kinetic energy loss, vertical displacement elastic behavior and qualitative analysis to establish elasticity behavior was done via high-speed camera footage (SA5, Photron, Japan) using Photron Fastcam Viewer software (Version 3.5.1, Photron, Japan) and visual observation. Damage mechanisms and behavior were qualitatively established by observation of the materials during and after shooting. The qualitative analysis found that of the two simulant materials tested, agar behaved more like brain in terms of damage and showed similar mechanical response to brain during the passage of the projectile, in terms of energy absorption and vertical velocity displacement. In conclusion agar showed a mechanical and subsequent damage response that was similar to brain compared to alginate. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Mechanical, Thermal and Surface Investigations of Chitosan/Agar/PVA Ternary Blended Films

    Directory of Open Access Journals (Sweden)

    Esam A. El-Hefian

    2011-01-01

    Full Text Available The mechanical and thermal properties of chitosan/agar/poly vinyl alcohol (CS/AG/PVA ternary blended films having various proportions considering chitosan as the main component were investigated. The various variables static water contact angle such as contact angle, drop base area, drop volume and drop height was also studied in correlation with the variation of time. Results obtained from mechanical measurements showed a noticeable increase in the tensile strength (TS coincided with a sharp decrease in elongation percent at break (E% of blended films with increasing agar and PVA contents. The DSC results prevailed the development of an interaction between chitosan individual components: agar and PVA. Moreover, an enhancement of the wettability of the blends was obtained with increasing agar and PVA contents. It was also found that the pure CS film and the blended films with 90/05/05 and 80/10/10 compositions were more affected by time than blended films with other compositions when the contact angle, the drop height and the drop length were studied as a function of time. In addition, when the drop is initially placed on the substrate, the drop area and the drop volume of all films remained almost constant up to a certain time after which they showed a slight difference with the elapse of time.

  11. Medium dependant production of corymbiferone a novel product from Penicillium hordei cultured on plant tissue agar

    DEFF Research Database (Denmark)

    Overy, David Patrick; Zidorn, C.; Petersen, B.O.

    2005-01-01

    Medium dependant production and the structure elucidation of corymbiferone (1) from the fungus Penicillitan hordei grown on oatmeal and macerated tulip, yellow onion and red onion agars are reported. Compound 1 possesses an unusual oxygenated aromatic structure with a lactone bridge preventing full...

  12. Spore-to-spore agar culture of the myxomycete Physarum globuliferum.

    Science.gov (United States)

    Liu, Pu; Wang, Qi; Li, Yu

    2010-02-01

    The ontogeny of the myxomycete Physarum globuliferum was observed on corn meal agar and hanging drop cultures without adding sterile oat flakes, bacteria or other microorganisms. Its complete life cycle including spore germination, myxamoebae, swarm cells, plasmodial development, and maturity of fructifications was demonstrated. Details of spore-to-spore development are described and illustrated.

  13. Potato carrot agar with manganese as an isolation medium for Alternaria, Epicoccum and Phoma

    DEFF Research Database (Denmark)

    Sørensen, Jens Laurids; Mogensen, Jesper Mølgaard; Thrane, Ulf

    2009-01-01

    A semi-selective medium for isolation of Alternaria spp., Epicoccum sp. and Phoma spp. from soil and plant samples was developed. The basal medium was a modified potato carrot agar (PCA), containing 10 g/L of potato and carrot. It is known that the target genera sporulate well on standard PCA when...

  14. Cell cytotoxicity and mycotoxin and secondary metabolite production by common penicillia on cheese agar

    DEFF Research Database (Denmark)

    Gareis, M.; Larsen, Thomas Ostenfeld; Frisvad, Jens Christian

    2002-01-01

    Known or potential new fungal starter culture species such as Penicillium camemberti, P. roqueforti, P. nalgiovense, P. caseifulvum, and P. solitum have been cultivated on a cheese agar medium together with the common cheese contaminants P. commune, P. crustosum, P. discolor, P. atramentosum, and P...

  15. Phenotypic differentiation of species from Aspergillus section Flavi on neutral red desiccated coconut agar

    DEFF Research Database (Denmark)

    Atanda, O. O.; Adetunji, M. C.; Ezekiel, C. N.

    2014-01-01

    In order to facilitate easy and rapid identification of aflatoxin-producing Aspergillus species, the phenotypic traits of Aspergillus section Flavi isolates were examined on neutral red desiccated coconut agar (NRDCA). Phenotype variations in colony morphology and the relationship between colour...

  16. Thallium toxicosis in a dog consequent to ingestion of Mycoplasma agar plates.

    Science.gov (United States)

    Puschner, Birgit; Basso, Marguerite M; Graham, Thomas W

    2012-01-01

    A 1-year-old dog ingested a mixture of blood agar and Mycoplasma agar plates. The Mycoplasma agar plates contained thallium acetate, which resulted in an estimated minimum dose of 5 mg thallium acetate/kg bodyweight. Clinical signs over the course of 2-3 weeks included vomiting, diarrhea, weight loss, alopecia, dysphonia, ataxia, paresthesia, intension tremors, megaesophagus with subsequent aspiration pneumonia, and several seizure episodes. The dog was treated with intravenous fluids and placement of a gastric feeding tube. Thallium concentrations in hair were 8.2 µg/g in samples taken on day 19, 16.4 µg/g in samples taken 3 months after exposure, 13.4 µg/g in samples taken 5 months after exposure, and nondetectable in samples taken 7 months after exposure. The blood thallium concentration was 190 µg/l on day 19 and nondetec table 3 months after exposure. Megaesophagus and dysphonia continued for 10 months after exposure. This case of thallium poisoning following ingestion of mycoplasma agar plates demonstrates that unusual sources of thallium still exist and suggests that thallium toxicosis should be included in the list of differential diagnoses in dogs presented with megaesophagus, especially if alopecia and other unexplained peripheral neuropathies are present. Hair and blood samples are useful specimens to reach an accurate diagnosis even if taken several weeks post exposure. The postexposure blood and hair thallium concentrations reported in this case are useful data for diagnosticians investigating dogs with potential thallium poisoning.

  17. Colwellia agarivorans sp. nov., an agar-digesting marine bacterium isolated from coastal seawater

    Science.gov (United States)

    A novel Gram-stain-negative, facultatively anaerobic, yellowish and agar-digesting marine bacterium, designated strain QM50**T, was isolated from coastal seawater in an aquaculture site near Qingdao, China. Phylogenetic analysis based on 16S rDNA sequences revealed that the novel isolate represented...

  18. Immediate differentiation of salmonella-resembling colonies on brilliant green agar

    DEFF Research Database (Denmark)

    Jensen, Annette Nygaard; Hoorfar, Jeffrey

    2000-01-01

    A rapid biochemical system (OBIS) based on immediate enzymatic differentiation of Citrobacter, Proteus, Providencia, Hafnia and Morganella spp. from Salmonella on brilliant green agar was evaluated A total of 96 field isolates from various Salmonella serotypes, 18 Citrobacter freundii and 25...

  19. Effects of season on the yield and quality of agar from Gelidium ...

    African Journals Online (AJOL)

    The aim of this work was to study the seasonal variations in the yield and physicochemical properties of agar of Gelidium sesquipedale. The algae were col lected from January 2011 to December 2011, from the coast of Mostaganem, western Algeria. The overall results show that the dry biomass of Gelidium sesquipedale ...

  20. Can serums be replaced by Mueller‑Hinton agar in germ tube test?

    African Journals Online (AJOL)

    2016-03-03

    Mar 3, 2016 ... various serums (i.e., human, rabbit, horse, and fetal bovine serum) used in the GTT and Mueller‑Hinton agar (MHA). Materials and Methods: Fifty species isolated from various clinical samples that were defined as C. albicans by both conventional and DNA sequence analysis methods were included in the ...

  1. Colony formation in agar: in vitro assay for haemopoietic stem cells

    NARCIS (Netherlands)

    Dicke, K.A.; Platenburg, M.G.C.; Bekkum, D.W. van

    1971-01-01

    Using a method in which embryo fibroblasts were used as feeder layers, the colony forming capacity in agar of a variety of mouse haemopoietic suspensions was compared with their CFUs content. A striking parallelism between the results of the two assays was found. In addition, under certain

  2. Growth and study of barium oxalate single crystals in agar gel

    Indian Academy of Sciences (India)

    Barium oxalate was grown in agar gel at ambient temperature. The effect of various parameters like gel concentration, gel setting time and concentration of the reactants on the growth of these crystals was studied. Prismatic platy shaped spherulites and dendrites were obtained. The grown crystals were characterized by ...

  3. Use of Dehydrated Agar to Estimate Microbial Water Quality for Horticulture Irrigation.

    Science.gov (United States)

    Meador, Dustin P; Fisher, Paul R; Guy, Charles L; Harmon, Philip F; Peres, Natalia A; Teplitski, Max

    2016-07-01

    Petrifilms are dehydrated agar culture plates that have been used to quantify colony forming units (CFU) mL of either aerobic bacteria (Petrifilm-AC) or fungus (Petrifilm-YM), depending on substrate composition. Microbes in irrigation systems can indicate biofilm risk and potential clogging of irrigation emitters. The research objective was to compare counts on Petrifilms versus traditional, hydrated-agar plates using samples collected from recirculated irrigation waters and cultures of isolated known species. The estimated count (in CFU mL) from a recirculated irrigation sample after 7 d of incubation on Petrifilm-YM was only 5.5% of the count quantified using sabouraud dextrose agar (SDA) with chloramphenicol after 14 d. In a separate experiment with a known species, Petrifilm-YM did not successfully culture zoospores of . Isolates of viable zoospores were cultured successfully on potato-dextrose agar (PDA), with comparable counts with a vegetable juice medium supplemented with the antibiotics pimaricin, ampicillin, rifamycin, pentochloronitrobenzene and hymexazol (PARP-H). The quantification of pv. Begoniaceae on Petrifilm-AC was not significantly different ( < 0.05) than on PDA, but was lower than on Reasoner and Goldrich agar (R2A) or with a hemocytometer. The current formulation of Petrifilm-YM is unlikely to be a useful monitoring method for plant pathogens in irrigation water because of the inability to successfully culture oomycetes. However, Petrifilm-AC was an effective method to quantify bacteria and can provide an easy-to-use on-farm tool to monitor biofilm risk and microbial density. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  4. Differentiating non-0157:H7 STEC serogroups from ground beef plated on agar media by hyperspetral imaging

    Science.gov (United States)

    Introduction: The development of an assay to detect and confirm a positive non-O157:H7 isolate is challenging when mixed morphologically results are obtained from the serogroups growing on Rainbow agar. Rainbow agar is only claimed by the manufacturer to be very specific for E.coli O157:H7 strain...

  5. Discolored Red Seaweed Pyropia yezoensis with Low Commercial Value Is a Novel Resource for Production of Agar Polysaccharides.

    Science.gov (United States)

    Sasuga, Keiji; Yamanashi, Tomoya; Nakayama, Shigeru; Ono, Syuetsu; Mikami, Koji

    2018-04-26

    The red seaweed Pyropia yezoensis has been demonstrated to be a novel resource for the production of high-quality agar. P. yezoensis is grown for the food industry in large-scale Japanese mariculture operations. However, discolored P. yezoensis is mostly discarded as an industrial waste, although it has some kind of utility values. Here, we evaluated the utility of discolored P. yezoensis as a resource for agar production. The quality of agar from the discolored seaweed was comparable to that from normal seaweed. In addition, as a distinguishing characteristic, agar yield was higher from discolored seaweeds than from normal types. Moreover, we successfully used agar from discolored P. yezoensis for bacterial plate media and DNA electrophoresis gels without agarose purification. Thus, our results demonstrate that discolored P. yezoensis is suitable for agar production and use in life science research. Diverting discolored P. yezoensis from disposal to agar production provides a solution to the current industrial waste problem in mariculture, as well as a secure source of agar for research purposes.

  6. Effect of lignin on water vapor barrier, mechanical, and structural properties of agar/lignin composite films.

    Science.gov (United States)

    Shankar, Shiv; Reddy, Jeevan Prasad; Rhim, Jong-Whan

    2015-11-01

    Biodegradable composite films were prepared using two renewable resources based biopolymers, agar and lignin alkali. The lignin was used as a reinforcing material and agar as a biopolymer matrix. The effect of lignin concentration (1, 3, 5, and 10wt%) on the performance of the composite films was studied. In addition, the mechanical, water vapor barrier, UV light barrier properties, FE-SEM, and TGA of the films were analyzed. The agar/lignin films exhibited higher mechanical and UV barrier properties along with lower water vapor permeability compared to the neat agar film. The FTIR and SEM results showed the compatibility of lignin with agar polymer. The swelling ratio and moisture content of agar/lignin composite films were decreased with increase in lignin content. The thermostability and char content of agar/lignin composite films increased with increased lignin content. The results suggested that agar/lignin films have a potential to be used as a UV barrier food packaging material for maintaining food safety and extending the shelf-life of the packaged food. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus

    NARCIS (Netherlands)

    Laarhoven, Bob; Elissen, H.J.H.; Temmink, H.; Buisman, C.J.N.

    2016-01-01

    An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv). The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water

  8. On the quantitative Amido Black B staining of protein spots in agar gel at low local protein concentrations

    NARCIS (Netherlands)

    Jansen, M.T.

    1962-01-01

    Protein spots in agar gel of identical protein content but different in surface area are found to bind different amounts of dye upon staining with Amido Black B. The lower the protein concentration within the agar gel, the more the Amido Black B content of the spot falls short of the value expected

  9. The bactericidal effect of carbon nanotube/agar composites irradiated with near-infrared light on Streptococcus mutans

    International Nuclear Information System (INIS)

    Akasaka, Tsukasa; Matsuoka, Makoto; Hashimoto, Takeshi; Abe, Shigeaki; Uo, Motohiro; Watari, Fumio

    2010-01-01

    Dental caries are mainly associated with oral pathogens, and Streptococcus mutans is a primary cariogenic organism. Many methods have been established to eliminate S. mutans from the oral cavity. This study aimed to evaluate the effect of carbon nanotube (CNT)/agar composites irradiated with near-infrared (NIR) light on S. mutans, as a potential photothermal antimicrobial nanotherapy. A colony-forming unit assay clearly showed that CNT/agar composites attain bactericidal activity after NIR light irradiation; this bactericidal activity is higher than that of graphite (GP)/agar and activated carbon (AC)/agar composites. Furthermore, it was observed that longer irradiation times immobilized S. mutans in the CNT/agar composite.

  10. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus.

    Directory of Open Access Journals (Sweden)

    Bob Laarhoven

    Full Text Available An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv. The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml, 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin. With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates.

  11. The bactericidal effect of carbon nanotube/agar composites irradiated with near-infrared light on Streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Akasaka, Tsukasa, E-mail: akasaka@den.hokudai.ac.jp [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan); Matsuoka, Makoto [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan); Hashimoto, Takeshi [Meijo Nano Carbon Co. Ltd., Otsubashi bldg. 4F, 3-4-10 Marunouchi, Naka-ku, Nagoya 460-0002 (Japan); Abe, Shigeaki; Uo, Motohiro; Watari, Fumio [Graduate School of Dental Medicine, Hokkaido University, Kita13 Nishi7, Kita-ku, Sapporo 060-8586 (Japan)

    2010-10-15

    Dental caries are mainly associated with oral pathogens, and Streptococcus mutans is a primary cariogenic organism. Many methods have been established to eliminate S. mutans from the oral cavity. This study aimed to evaluate the effect of carbon nanotube (CNT)/agar composites irradiated with near-infrared (NIR) light on S. mutans, as a potential photothermal antimicrobial nanotherapy. A colony-forming unit assay clearly showed that CNT/agar composites attain bactericidal activity after NIR light irradiation; this bactericidal activity is higher than that of graphite (GP)/agar and activated carbon (AC)/agar composites. Furthermore, it was observed that longer irradiation times immobilized S. mutans in the CNT/agar composite.

  12. Control of the pattern of perithecium development in Sordaria fimicola on agar medium.

    Science.gov (United States)

    Pollock, R T

    1975-06-01

    In a Sordaria fimicola (Rob.) Ces. and de Not. colony grown on agar medium in a petri plate, perithecia developed in a narrow band around the plate edge after the colony margin reached the edge. Physical wounding of the colony carried out shortly before or during the time perithecia were developing around the plate edge stimulated perithecium development in the wound area. Diffusion barriers were created by cutting small trenches in the agar parallel to the plate edge. The trenches were made at several different positions between the plate center and edge using cultures of several different ages, and the resultant distribution of perithecia along the trench edges suggested that the colony center and periphery produce diffusible inhibitors of perithecium development. These inhibitors may be responsible, in part, for the observed pattern of perithecium development in the colony.

  13. Substances used as gelling agent alternative to the agar in culture media for in vitro propagation

    Directory of Open Access Journals (Sweden)

    Darío Alonso Martin Gordo

    2012-10-01

    Full Text Available The cultivation of plant fibers is achieved through the implementation of a group of techniques widely used for the propagation of plants in vitro. However, one disadvantage of these techniques is the high cost of components used for the crop’s medium, among these, the agar (primary gelling agent, has seen a price increase due to high demand. This article consults several studies regarding substances that have been utilized as alternative gelling agents, among which highlight starches (native or modified and several plant gums and bacterial excretions that have been used in processes of organogenesis, embryogenesis and vegetative proliferation. The starches and gums studied showed favorable results in the in vitro cultivation of some plant species. The study demonstrates that both gums and starches may be potential substitutes (either partial or total for agar, achieve a decrease in costs associated with starches, and have an ability to be chemically modified to improve gelling capacity.

  14. Sterilization of MacConkey agar and CLED medium by gamma-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bogokowsky, B; Eisenberg, E; Altmann, G

    1983-10-01

    MacConkey agar and Cystine-Lactose-Electrolyte-Deficient (CLED) agar, media widely used in the bacteriological laboratory and recommended for the detection of urinary tract infections, were sterilized by gamma-radiation at a dose of 1.5 Mrad. Both were modified and adapted to radiation sterilization by adding sodium thioglycollate as a radioprotectant, and by increasing their indicator content. The media performed well when tested with different Enterobacteria and other micro-organisms. Growth and change of indicator reaction were equal in irradiated and autoclaved culture media. Culture media were also evaluated after storage for one month at room temperature and at 4 degrees C and compared well with freshly autoclaved media.

  15. Sterilization of MacConkey agar and CLED medium by. gamma. -radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bogokowsky, B; Altmann, G [Sheba Medical Center, Tel Hashomer (Israel); Tel Aviv Univ. (Israel). Medical School); Eisenberg, E [Israel Atomic Energy Commission, Yavne. Soreq Nuclear Research Center

    1983-10-01

    MacConkey agar and Cystine-Lactose-Electrolyte-Deficient (CLED) agar, media widely used in the bacteriological laboratory and recommended for the detection of urinary tract infections, were sterilized by ..gamma..-radiation at a dose of 1.5 Mrad. Both were modified and adapted to radiation sterilization by adding sodium thioglycollate as a radioprotectant, and by increasing their indicator content. The media performed well when tested with different Enterobacteria and other micro-organisms. Growth and change of indicator reaction were equal in irradiated and autoclaved culture media. Culture media were also evaluated after storage for one month at room temperature and at 4/sup 0/C and compared well with freshly autoclaved media.

  16. Ophthalmic ester removal in the agar state giant molecule; Kantenjo kobunshi de futarusan esuteru jokyo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-10-01

    Matsubara professors of Tokyo College of Pharmacy developed the technique which simply removed phthalic ester from the solution. The property in which the giant molecule called the poly N isopropyl acrylamide cohered like the agar, when 32 degrees C is exceeded, was utilized, and the phthalic ester of poor solubility is taken in the flocculation stage. It is expected with that it can be utilized for wastewater treatment and solicitation quantity thing analysis in the environment. (translated by NEDO)

  17. Comparison of the Etest and the routine multi-disc agar diffusion ...

    African Journals Online (AJOL)

    Results: On the Etest strips, Staph aureus was 83.5% sensitive to ciprofloxacin, 52.6% to gentamicin, 48.5% to ampicillin and 8.2% to chloramphenicol while on the multi-disc agar diffusion plates 80.4% of Staph aureus were sensitive to ciprofloxacin, 49.5% to gentamicin, 39.2% to ampicillin and 12.4% to chloramphenicol.

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

    Science.gov (United States)

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

    2013-01-01

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

  19. Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species

    OpenAIRE

    Marol Serhat; Yücesoy Mine

    2003-01-01

    Abstract Background The importance of identifying the pathogenic fungi rapidly has encouraged the development of differential media for the presumptive identification of yeasts. In this study two differential media, CHROMagar Candida and bismuth sulphite glucose glycine yeast agar, were evaluated for the presumptive identification of yeast species. Methods A total number of 270 yeast strains including 169 Candida albicans, 33 C. tropicalis, 24 C. glabrata, 18 C. parapsilosis, 12 C. krusei, 5 ...

  20. Scintigraphic evidence of the retarded insulin liberation from agar embeddings in suppositories

    International Nuclear Information System (INIS)

    Losse, G.; Mueller, F.; Fischer, S.

    1989-01-01

    It is reported on the retardation and protective effect of insulin-agar-embeddings in triglyceride suppositories by in vitro and in vivo tests on rabbits. The discovered effects were visually followed by gamma scanning of adequate rectally applied 131 I-insulin specimens in the rectum and thyroid gland and, in relation with the glucose lowering course, the liberation, distribution and biovailability of the immobilized hormone was illustrated. (author)

  1. Cytotoxicity of ferrite particles by MTT and agar diffusion methods for hyperthermic application

    International Nuclear Information System (INIS)

    Kim, Dong-Hyun; Lee, Se-Ho; Kim, Kyoung-Nam; Kim, Kwang-Mahn; Shim, In-Bo; Lee, Yong-Keun

    2005-01-01

    We investigated the cytotoxicity of the prepared various ferrites (Fe-, Li-, Ni/Zn/Cu-, Ba-, Sr-, Co-, Co/Ni-ferrites) using MTT assay as well as agar diffusion method. Their cytotoxicity was compared with that of alginate-encapsulated ferrites. In the MTT assay, Fe 3 O 4 and SrFe 12 O 19 ferrite showed the highest cell viability of 90%. Alginate-encapsulated Ba-ferrite was ranked mildly cytotoxic, whereas their ferrite particles were ranked cytotoxic

  2. Growth of non-Campylobacter, oxidase-positive bacteria on selective Campylobacter agar.

    OpenAIRE

    Moskowitz, L B; Chester, B

    1982-01-01

    A total of 67 oxidase-positive, gram-negative bacteria were tested for growth on selective Campylobacter agar (Blaser formulation, BBL Microbiology Systems, Cockeysville, Md.) at 42 degrees C under microaerophilic conditions. Although the growth of most of these bacteria was prevented, all strains of Achromobacter xylosoxidans, Pseudomonas aeruginosa, Pseudomonas putrefaciens, Pseudomonas alcaligenes, and Pseudomonas pseudoalcaligenes grew as well as Campylobacter fetus subsp. jejuni.

  3. Scintigraphic evidence of the retarded insulin liberation from agar embeddings in suppositories

    Energy Technology Data Exchange (ETDEWEB)

    Losse, G; Mueller, F; Fischer, S; Wunderlich, G; Hacker, E

    1989-05-01

    It is reported on the retardation and protective effect of insulin-agar-embeddings in triglyceride suppositories by in vitro and in vivo tests on rabbits. The discovered effects were visually followed by gamma scanning of adequate rectally applied /sup 131/I-insulin specimens in the rectum and thyroid gland and, in relation with the glucose lowering course, the liberation, distribution and biovailability of the immobilized hormone was illustrated. (author).

  4. Evaluation of a Chromogenic Agar under Development To Screen for VRE Colonization ▿

    OpenAIRE

    Kallstrom, George; Doern, Christopher D.; Dunne, W. Michael

    2010-01-01

    BBL CHROMagar VanRE (CVRE) was compared with bile esculin azide agar plus vancomycin to screen for vancomycin-resistant enterococcus (VRE) colonization. CVRE distinguishes Enterococcus faecalis (green colonies) from Enterococcus faecium (mauve colonies) on the basis of chromogenic substrate use. CVRE sensitivity and specificity were 98.6% and 99.1%. Positive and negative predictive values were 95.9% and 99.7%.

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

    Directory of Open Access Journals (Sweden)

    Hsi Liu

    2016-11-01

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

  6. Preparation of amine-impregnated silica foams using agar as the gelling agent

    Energy Technology Data Exchange (ETDEWEB)

    Jardim, Iara M., E-mail: iaramj01@yahoo.com.br [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais – UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG, CEP: 31270-901, Escola de Engenharia, bloco 2, sala, 2230 (Brazil); Department of Chemical Engineering, Federal University of Minas Gerais – UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG, CEP: 31270-901, Escola de Engenharia, bloco 2, 5° andar (Brazil); Souza, Douglas F.; Vasconcelos, Daniela C.L.; Nunes, Eduardo H.M. [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais – UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG, CEP: 31270-901, Escola de Engenharia, bloco 2, sala, 2230 (Brazil); Vasconcelos, Wander L., E-mail: wlv@demet.ufmg.br [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais – UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG, CEP: 31270-901, Escola de Engenharia, bloco 2, sala, 2230 (Brazil)

    2016-10-15

    In this work we successfully prepared amine-impregnated gel-cast silica foams using agar and atmospheric air as the gelling agent and heat treatment atmosphere, respectively. The concentration of 3,6-anhydrogalactose in agar was evaluated by ultraviolet–visible spectroscopy (UV–Vis). The obtained foams were examined by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG) coupled to mass spectrometry (TG-MS), scanning electron microscopy (SEM), X-ray microtomography (micro-CT), and Archimedes method. The cold crushing strength of the materials prepared in this work was assessed using a mechanical testing stage available in the micro-CT system. The obtained foams exhibited a highly interconnected pore network, with an expressive presence of open pores. Samples heat-treated at 1300 °C for 2 h showed both an expressive porosity (≈ 77%) and a significant cold crushing strength (≈ 1.4 MPa). It was observed that the calcination of the prepared materials at 1200 °C for times as long as 16 h may lead to the rupture of pore walls. FTIR and TG-MS revealed that amine groups were properly incorporated into the foams structure. - Highlights: •Successful preparation of amine-impregnated gel-cast silica foams •Agar used as the gelling agent •Samples with expressive porosity and cold crushing strength •Sintering times as long as 16 h led to the rupture of the pore network.

  7. Preparation of amine-impregnated silica foams using agar as the gelling agent

    International Nuclear Information System (INIS)

    Jardim, Iara M.; Souza, Douglas F.; Vasconcelos, Daniela C.L.; Nunes, Eduardo H.M.; Vasconcelos, Wander L.

    2016-01-01

    In this work we successfully prepared amine-impregnated gel-cast silica foams using agar and atmospheric air as the gelling agent and heat treatment atmosphere, respectively. The concentration of 3,6-anhydrogalactose in agar was evaluated by ultraviolet–visible spectroscopy (UV–Vis). The obtained foams were examined by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG) coupled to mass spectrometry (TG-MS), scanning electron microscopy (SEM), X-ray microtomography (micro-CT), and Archimedes method. The cold crushing strength of the materials prepared in this work was assessed using a mechanical testing stage available in the micro-CT system. The obtained foams exhibited a highly interconnected pore network, with an expressive presence of open pores. Samples heat-treated at 1300 °C for 2 h showed both an expressive porosity (≈ 77%) and a significant cold crushing strength (≈ 1.4 MPa). It was observed that the calcination of the prepared materials at 1200 °C for times as long as 16 h may lead to the rupture of pore walls. FTIR and TG-MS revealed that amine groups were properly incorporated into the foams structure. - Highlights: •Successful preparation of amine-impregnated gel-cast silica foams •Agar used as the gelling agent •Samples with expressive porosity and cold crushing strength •Sintering times as long as 16 h led to the rupture of the pore network.

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

    Directory of Open Access Journals (Sweden)

    Emma R Cold

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

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

    Directory of Open Access Journals (Sweden)

    Fabíola Silveira-Gomes

    2011-08-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

  11. Calibration of Ge(Li) semiconductor detector by method using agar volume source

    International Nuclear Information System (INIS)

    Yanase, Nobuyuki; Kasai, Atsushi

    1979-12-01

    The Ge(Li) semiconductor detector was calibrated for measurements of environmental samples. The radioisotopes used for standard sources are 22 Na, 51 Cr, 56 Co, 57 Co, 133 Ba, 137 Cs, 144 Ce and 241 Am. These are mixed with hot agar aqueous solution and fixed uniformly in a cylindrical plastic case in cooling. The agar volume source is advantageous in handling over the fluid aqueous source. The prepared cylindrical standard sources are in diameters 6 and 8 cm and thicknesses 1, 5, 10, 20, 30 and 40 mm (only for 8 cm diameter). The radioactivities of prepared standard sources are between 0.03 μCi and 0.2 μCi. It takes only a week to make the calibration except data processing. The obtained full energy peak efficiency curves include 5 - 10% error due to preparation of agar source, reference radioactivity data of purchased standard solutions, reference data of branching ratio of gamma-ray and sum effect. The efficiency curves, however, are sufficient for quantitative analysis of environmental samples. (author)

  12. N-acetylgalatosamine-mediated regulation of the aga operon by AgaR in Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    Muhammad Afzal

    2016-09-01

    Full Text Available Here, we analyze the transcriptomic response of Streptococcus pneumoniae D39 to N-acetylgalactosamine (NAGa. Transcriptome comparison of S. pneumoniae D39 grown NAGaM17 (0.5% NAGa + M17 to that grown in GM17 (0.5% Glucose + M17 revealed the elevated expression of various carbon metabolic genes/operons, including a PTS operon (denoted here as the aga operon, which is putatively involved in NAGa transport and utilization, in the presence of NAGa. We further studied the role of a GntR-family transcriptional regulator (denoted here as AgaR in the regulation of aga operon. Our transcriptome and RT-PCR data suggest the role of AgaR as a transcriptional repressor of the aga operon. We predicted a 20-bp operator site of AagR (5’- ATAATTAATATAACAACAAA -3’ in the promoter region of the aga operon (PbgaC, which was further verified by mutating the AgaR operator site in the respective promoter. The role of CcpA in the additional regulation of the aga operon was elucidated by further transcriptome analyses and confirmed by quantitative RT-PCR.

  13. AgarTrap: a simplified Agrobacterium-mediated transformation method for sporelings of the liverwort Marchantia polymorpha L.

    Science.gov (United States)

    Tsuboyama, Shoko; Kodama, Yutaka

    2014-01-01

    The liverwort Marchantia polymorpha L. is being developed as an emerging model plant, and several transformation techniques were recently reported. Examples are biolistic- and Agrobacterium-mediated transformation methods. Here, we report a simplified method for Agrobacterium-mediated transformation of sporelings, and it is termed Agar-utilized Transformation with Pouring Solutions (AgarTrap). The procedure of the AgarTrap was carried out by simply exchanging appropriate solutions in a Petri dish, and completed within a week, successfully yielding sufficient numbers of independent transformants for molecular analysis (e.g. characterization of gene/protein function) in a single experiment. The AgarTrap method will promote future molecular biological study in M. polymorpha.

  14. Ergosterol purification from basidiomes of Clouded Agaric (Clitocybe nebularis (Fr. Kumm.

    Directory of Open Access Journals (Sweden)

    V. O. Antonyuk

    2014-08-01

    Full Text Available Ergosterol (ergosta-5 ,7,22-trien-3β-ol is a compound found only in fungi. Ergosterol has medical interest, as it is easily converted into Vitamin D2. In the previous work we have studied 22 species of true fungi. The highest quantity of ergosterol was found in basidiomes of Clouded Agaric (Clitocybe nebularis (Fr. Kumm. Meanwhile, there is no data on the purification of ergosterol from this fungus in the literature. The aim of research. The aim of research is to elaborate a rational method of obtaining ergosterol from basidiomes of Clouded Agaric and assess the perspectives of the raw material for its purification. Materials and methods. In order to choose the best method of ergosterol purification, it was obtained in two ways: 1 by alkaline hydrolisis that was used in the preparation of ergosterol from baker yeast and 2 by the extraction of raw matherial by methanol with following chromatography on silica gel. A substance with high ergosterol level was purified from marc basidiomes of Clouded Agaric by methanol extraction with following of freezing the methanol extract and the following chromatography on silica gel. This substance was dissolved in hexane and purified by chromatography on silica gel by washing the column sequentially with hexane, hexane - ethyl acetate (6:1 , hexane -ethyl acetate -methanol 4:2:1. The obtained fractions were dried and weighed. The analysis of the obtained compounds was carried out by gas-liquid сhromatography - mass spectrometry , Lieberman-Burchard reaction and TLC on silica gel. Chromatograms were spraied with saturated sodium antimony in chloroform. Results and discussion Pure ergosterol was obtained from dried baker's yeast and basidiomes marc of Clouded Agaric by alkaline hydrolysis followed by methylene chloride extraction of raw material and crystallization from ethanol and mixtures of benzene with ethanol (yield 0.71% and 0.52% . Methanol extraction of dried basidiomes marc of Clouded Agaric

  15. Observation of interactions between hydrophilic ionic liquid and water on wet agar gels by FE-SEM and its mechanism

    International Nuclear Information System (INIS)

    Takahashi, Chisato; Shirai, Takashi; Fuji, Masayoshi

    2012-01-01

    Highlights: ► The mechanism of SEM observation of agar gel using ionic liquid was investigated. ► Weak hydrogen bond between ionic liquid and water exist even under vacuum condition. ► Ionic liquid binding ability with water is useful for observing wet material using FE-SEM. ► We could optimize the water concentrations of sample of IL and wet material mixtures. ► SEM observation of fine morphology of agar gel in optimum water content. - Abstract: In the present study, an attempt is made to understand the mechanism of field emission electron microscopy (FE-SEM) observation of wet agar gel using a typical hydrophilic ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate; [BMIM][BF 4 ]. The IL interaction with water molecules within agar gel during sample preparation condition for FE-SEM observation was investigated using Raman spectroscopy. Results showed that water molecules within agar gel form weak hydrogen bond such as BF 4 − ⋯HOH⋯BF 4 − by interaction with BF 4 − of IL, and, it remained stable even under vacuum condition at 60 °C, 24 h. This interaction was found to be helpful for IL displacement of the water molecules within agar gel. From this study, it was found that the exact morphology of gel materials in FE-SEM condition can be observed by optimization of water concentrations of IL and gel mixtures. Thus, using IL, agar gel or any other material under wet condition can be observed without drying in FE-SEM chamber, and, present result gives an insight to the mechanism of FE-SEM observation of agar gel using IL without any conducting coating.

  16. Cytotoxicity of ferrite particles by MTT and agar diffusion methods for hyperthermic application

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Hyun [Brain Korea 21 Project for Medical Science, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Lee, Se-Ho [Brain Korea 21 Project for Medical Science, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Kim, Kyoung-Nam [Brain Korea 21 Project for Medical Science, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Kim, Kwang-Mahn [Brain Korea 21 Project for Medical Science, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of); Shim, In-Bo [Department of Electronic Physics, Kookmin University, Seoul 136-702 (Korea, Republic of); Lee, Yong-Keun [Brain Korea 21 Project for Medical Science, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of) and Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 120-752 (Korea, Republic of)]. E-mail: leeyk@yumc.yonsei.ac.kr

    2005-05-15

    We investigated the cytotoxicity of the prepared various ferrites (Fe-, Li-, Ni/Zn/Cu-, Ba-, Sr-, Co-, Co/Ni-ferrites) using MTT assay as well as agar diffusion method. Their cytotoxicity was compared with that of alginate-encapsulated ferrites. In the MTT assay, Fe{sub 3}O{sub 4} and SrFe{sub 12}O{sub 19} ferrite showed the highest cell viability of 90%. Alginate-encapsulated Ba-ferrite was ranked mildly cytotoxic, whereas their ferrite particles were ranked cytotoxic.

  17. Three-dimensional characterization of bacterial microcolonies on solid agar-based culture media.

    Science.gov (United States)

    Drazek, Laurent; Tournoud, Maud; Derepas, Frédéric; Guicherd, Maryse; Mahé, Pierre; Pinston, Frédéric; Veyrieras, Jean-Baptiste; Chatellier, Sonia

    2015-02-01

    For the last century, in vitro diagnostic process in microbiology has mainly relied on the growth of bacteria on the surface of a solid agar medium. Nevertheless, few studies focused in the past on the dynamics of microcolonies growth on agar surface before 8 to 10h of incubation. In this article, chromatic confocal microscopy has been applied to characterize the early development of a bacterial colony. This technology relies on a differential focusing depth of the white light. It allows one to fully measure the tridimensional shape of microcolonies more quickly than classical confocal microscopy but with the same spatial resolution. Placing the device in an incubator, the method was able to individually track colonies growing on an agar plate, and to follow the evolution of their surface or volume. Using an appropriate statistical modeling framework, for a given microorganism, the doubling time has been estimated for each individual colony, as well as its variability between colonies, both within and between agar plates. A proof of concept led on four bacterial strains of four distinct species demonstrated the feasibility and the interest of the approach. It showed in particular that doubling times derived from early tri-dimensional measurements on microcolonies differed from classical measurements in micro-dilutions based on optical diffusion. Such a precise characterization of the tri-dimensional shape of microcolonies in their late-lag to early-exponential phase could be beneficial in terms of in vitro diagnostics. Indeed, real-time monitoring of the biomass available in a colony could allow to run well established microbial identification workflows like, for instance, MALDI-TOF mass-spectrometry, as soon as a sufficient quantity of material is available, thereby reducing the time needed to provide a diagnostic. Moreover, as done for pre-identification of macro-colonies, morphological indicators such as three-dimensional growth profiles derived from

  18. Effect of growth parameters on spatial pattern formation of cadmium hydroxide in agar gel

    International Nuclear Information System (INIS)

    Palaniandavar, N.; Gnanam, F.D.; Ramasamy, P.

    1986-01-01

    The interrelated effects of growth parameters on spatial pattern formation of cadmium hydroxide in agar gel medium have been investigated. The main parameters are concentration of electrolytes, pH of the medium, density of the gel, the concentration of parasitic electrolyte and the concentration of additives. The pattern formation is explained on the basis of electrical double layer theory coupled with diffusion. Using Shinohara's revised coagulation concept, the flocculation value is calculated. With suitable combinations of parameter values, dendritic growth and spherulitic growth of cadmium hydroxide crystals have been observed. (author)

  19. Biofilm Removal and Antimicrobial Activities of Agar Hydrogel Containing Colloid Nano-Silver against Staphylococcus aureus and Salmonella typhimurium

    Directory of Open Access Journals (Sweden)

    Leyla Sadat Bouryabaf

    2017-10-01

    Full Text Available Background:    Antibacterial and biofilm removal effects of agar hydrogel incorporating silver nanoparticles (SNP at various concentrations were studied against Staphylococcus aureus and Salmonella typhimurium in vitro.Methods:      The minimum inhibitory concentrations (MIC of SNP was determined by agar dilution method. Then, hydrogels were prepared by mixing of 0.5% w/v agar and SNP (1/2 MIC, MIC, and 2 MIC and their inhibitory efficacies against planktonic and biofilm forms of bacteria were measured using agar spot and microtiter test, respectively.Results:    The MIC value was 125 µg/ mL for both bacteria. All SNP hydrogels represented antibacterial activity against Staphylococcus aureus and S. typhimurium on agar culture, which was significant compared to control group (silver sulfadiazine cream. The developed biofilm of S. aureus and S. typhimurium were strongly (85% reduction and modernly affected (60% reduction by SNP hydrogels during 15 min contact time, respectively. A dose-dependent biofilm reduction was not demonstrated when different SNP concentrations were tested. Moreover, the results from this study confirmed the moderate sanitizing ability of SNP loaded hydrogel against planktonic forms of both bacteria, which SNP (2MIC hydrogel decreased only 2.3 log10 CFU/ mL in a primary population of S. typhimurium during 15 min exposure time.Conclusion:     We recommended SNP incorporated agar hydrogel as an effective biofilm removal sanitizer.

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

    Directory of Open Access Journals (Sweden)

    N Karabulut

    2014-01-01

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

  1. The Efficiency of UVC Radiation in the Inactivation of Listeria monocytogenes on Beef-Agar Food Models

    Directory of Open Access Journals (Sweden)

    Christian James

    2015-01-01

    Full Text Available The aim of this study is to evaluate the eff ect of meat content and surface smoothness on the deactivation of Listeria monocytogenes in beef-agar food models achieved by shortwave ultraviolet (UVC light. Food models with various meat contents were made using chopped beef slices and agar solution. Prepared models together with a Listeria selective agar (LSA plate and a slice of cooked beef were inoculated with L. monocytogenes and then exposed to UVC light. Population of Listeria reduced to below the level of detection on the LSA plates. As the content of beef in the beef-agar models increased, more L. monocytogenes cells survived. Survival was greatest on the treated cooked slice of beef. To bett er understand the effect of surface irregularities, a white light interferometer was used to analyse the surface smoothness of beef-agar media and LSA plates. No correlation was observed between the surface roughness of seven out of nine types of produced beef-agar media and the degree of inactivation resulting from UVC radiation at the given dose, whereas, less bacterial cells were killed as beef content of the food models increased. The findings of the current study show that the chemical composition of the treated sample also plays an important role in pathogen resistance and survival, meaning that two samples with similar surface irregularities but diff erent chemical composition might produce very diff erent inactivation results when exposed to UVC light.

  2. Characterization of internal structure of hydrated agar and gelatin matrices by cryo-SEM

    KAUST Repository

    Rahbani, Janane; Behzad, Ali Reza; Khashab, Niveen M.; Al-Ghoul, Mazen

    2012-01-01

    There has been a considerable interest in recent years in developing polymer gel matrices for many important applications such as 2DE for quantization and separation of a variety of proteins and drug delivery system to control the release of active agents. However, a well-defined knowledge of the ultrastructures of the gels has been elusive. In this study, we report the characterization of two different polymers used in 2DE: Gelatin, a naturally occurring polymer derived from collagen (protein) and agar, a polymer of polysaccharide (sugar) origin. Low-temperature SEM is used to examine the internal structure of these gels in their frozen natural hydrated states. Results of this study show that both polymers have an array of hollow cells that resembles honeycomb structures. While agar pores are almost circular, the corresponding Gaussian curve is very broad exhibiting a range of radii from nearly 370 to 700 nm. Gelatin pores are smaller and more homogeneous reflecting a narrower distribution from nearly 320 to 650 nm. Overall, these ultrastructural findings could be used to correlate with functions of the polymers. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Visualization of Biosurfactant Film Flow in a Bacillus subtilis Swarm Colony on an Agar Plate.

    Science.gov (United States)

    Kim, Kyunghoon; Kim, Jung Kyung

    2015-08-26

    Collective bacterial dynamics plays a crucial role in colony development. Although many research groups have studied the behavior of fluidic swarm colonies, the detailed mechanics of its motion remains elusive. Here, we developed a visualization method using submicron fluorescent beads for investigating the flow field in a thin layer of fluid that covers a Bacillus subtilis swarm colony growing on an agar plate. The beads were initially embedded in the agar plate and subsequently distributed spontaneously at the upper surface of the expanding colony. We conducted long-term live cell imaging of the B. subtilis colony using the fluorescent tracers, and obtained high-resolution velocity maps of microscale vortices in the swarm colony using particle image velocimetry. A distinct periodic fluctuation in the average speed and vorticity of flow in swarm colony was observed at the inner region of the colony, and correlated with the switch between bacterial swarming and growth phases. At the advancing edge of the colony, both the magnitudes of velocity and vorticity of flow in swarm colony were inversely correlated with the spreading speed of the swarm edge. The advanced imaging tool developed in this study would facilitate further understanding of the effect of micro vortices in swarm colony on the collective dynamics of bacteria.

  4. Mechanical and water barrier properties of agar/κ-carrageenan/konjac glucomannan ternary blend biohydrogel films.

    Science.gov (United States)

    Rhim, Jong-Whan; Wang, Long-Feng

    2013-07-01

    Multicomponent hydrogel films composed of agar, κ-carrageenan, konjac glucomannan powder, and nanoclay (Cloisite(®) 30B) were prepared and their mechanical and water barrier properties such as water vapor permeability (WVP), water contact angle (CA), water solubility (WS), water uptake ratio (WUR), water vapor uptake ratio (WVUR) were determined. Mechanical, water vapor barrier, and water resistance properties of the ternary blend film exhibited middle range of individual component films, however, they increased significantly after formation of nanocomposite with the clay. Especially, the water holding capacity of the ternary blend biopolymer films increased tremendously, from 800% to 1681% of WUR for agar and κ-carrageenan films up to 5118% and 5488% of WUR for the ternary blend and ternary blend nanocomposite films, respectively. Water vapor adsorption behavior of films was also tested by water vapor adsorption kinetics and water vapor adsorption isotherms test. Preliminary test result for fresh spinach packaging revealed that the ternary blend biohydrogel films had a high potential for the use as an antifogging film for packaging highly respiring agricultural produce. In addition, the ternary blend nanocomposite film showed an antimicrobial activity against Gram-positive bacteria, Listeria monocytogenes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Gamma radiation effect on agar viscosity for use in food industry

    International Nuclear Information System (INIS)

    Aliste, Antonio J.; Del Mastro, Nelida L.

    1999-01-01

    The application of food radiation processing is increasing worldwide mainly because of its efficiency in the industrial decontamination of packaged food products. Indeed, the process neither introduces any undesirable elements nor increases the temperature, thus allowing the preparation of ready-to-use products which remain stable for long periods at room temperature. The aim of this work was to study the effect of Co-60 gamma radiation on the viscosity of agar. This hydrocolloid derived from seaweed is a galactose polymer with a high hysteresis capacity (great difference among melting and gelification temperature) which is extremely important when used as additive for the food industry. Commercial agar was irradiated with doses of 0, 1, 5 and 10 kGy. Proper dilutions were prepared and the viscosity was measured in a Brookfield model LVDVIII viscosimeters. The relationships viscosity/dose for the temperatures of 45 deg C and 60 deg C were established. The decrease of the viscosity was 71.4% and 49.6% respectively when the applied dose was 10 kGy. The implications of the use of this additive in food irradiation are discussed. (author)

  6. Mechanical response of agar gel irradiated with Nd:YAG nanosecond laser pulses

    Science.gov (United States)

    Pérez-Gutiérrez, Francisco G.; Evans, Rodger; Camacho-López, Santiago; Aguilar, Guillermo

    2010-02-01

    Nanosecond long laser pulses are used in medical applications where precise tissue ablation with minimal thermal and mechanical collateral damage is required. When a laser pulse is incident on a material, optical energy will be absorbed by a combination of linear and nonlinear absorption according to both: laser light intensity and material properties. In the case of water or gels, the first results in heat generation and thermoelastic expansion; while the second results in an expanding plasma formation that launches a shock wave and a cavitation/boiling bubble. Plasma formation due to nonlinear absorption of nanosecond laser pulses is originated by a combination of multiphoton ionization and thermionic emission of free electrons, which is enhanced when the material has high linear absorption coefficient. In this work, we present measurements of pressure transients originated when 6 ns laser pulses are incident on agar gels with varying linear absorption coefficient, mechanical properties and irradiation geometry using laser radiant exposures above threshold for bubble formation. The underlying hypothesis is that pressure transients are composed of the superposition of both: shock wave originated by hot expanding plasma resulting from nonlinear absorption of optical energy and, thermoelastic expansion originated by heat generation due to linear absorption of optical energy. The objective of this work is to evaluate the relative contribution of each absorption mechanism to mechanical effects in agar gel. Real time pressure transients are recorded with PVDF piezoelectric sensors and time-resilved imaging from 50 μm to 10 mm away from focal point.

  7. An agar gel membrane-PDMS hybrid microfluidic device for long term single cell dynamic study.

    Science.gov (United States)

    Wong, Ieong; Atsumi, Shota; Huang, Wei-Chih; Wu, Tung-Yun; Hanai, Taizo; Lam, Miu-Ling; Tang, Ping; Yang, Jian; Liao, James C; Ho, Chih-Ming

    2010-10-21

    Significance of single cell measurements stems from the substantial temporal fluctuations and cell-cell variability possessed by individual cells. A major difficulty in monitoring surface non-adherent cells such as bacteria and yeast is that these cells tend to aggregate into clumps during growth, obstructing the tracking or identification of single-cells over long time periods. Here, we developed a microfluidic platform for long term single-cell tracking and cultivation with continuous media refreshing and dynamic chemical perturbation capability. The design highlights a simple device-assembly process between PDMS microchannel and agar membrane through conformal contact, and can be easily adapted by microbiologists for their routine laboratory use. The device confines cell growth in monolayer between an agar membrane and a glass surface. Efficient nutrient diffusion through the membrane and reliable temperature maintenance provide optimal growth condition for the cells, which exhibited fast exponential growth and constant distribution of cell sizes. More than 24 h of single-cell tracking was demonstrated on a transcription-metabolism integrated synthetic biological model, the gene-metabolic oscillator. Single cell morphology study under alcohol toxicity allowed us to discover and characterize cell filamentation exhibited by different E. coli isobutanol tolerant strains. We believe this novel device will bring new capabilities to quantitative microbiology, providing a versatile platform for single cell dynamic studies.

  8. Evaluation of a modified Cefsulodin-Irgasan-Novobiocin agar for isolation of Yersinia spp.

    Directory of Open Access Journals (Sweden)

    Lai Kuan Tan

    Full Text Available Y. enterocolitica and Y. pseudotuberculosis are important food borne pathogens. However, the presence of competitive microbiota makes the isolation of Y. enterocolitica and Y. pseudotuberculosis from naturally contaminated foods difficult. We attempted to evaluate the performance of a modified Cefsulodin-Irgasan-Novobiocin (CIN agar in the differentiation of Y. enterocolitica from non-Yersinia species, particularly the natural intestinal microbiota. The modified CIN enabled the growth of Y. enterocolitica colonies with the same efficiency as CIN and Luria-Bertani agar. The detection limits of the modified CIN for Y. enterocolitica in culture medium (10 cfu/ml and in artificially contaminated pork (10(4 cfu/ml were also comparable to those of CIN. However, the modified CIN provided a better discrimination of Yersinia colonies from other bacteria exhibiting Yersinia-like colonies on CIN (H2S-producing Citrobacter freundii, C. braakii, Enterobacter cloacae, Aeromonas hydrophila, Providencia rettgeri, and Morganella morganii. The modified CIN exhibited a higher recovery rate of Y. enterocolitica from artificially prepared bacterial cultures and naturally contaminated samples compared with CIN. Our results thus demonstrated that the use of modified CIN may be a valuable means to increase the recovery rate of food borne Yersinia from natural samples, which are usually contaminated by multiple types of bacteria.

  9. Characterization of internal structure of hydrated agar and gelatin matrices by cryo-SEM

    KAUST Repository

    Rahbani, Janane

    2012-12-26

    There has been a considerable interest in recent years in developing polymer gel matrices for many important applications such as 2DE for quantization and separation of a variety of proteins and drug delivery system to control the release of active agents. However, a well-defined knowledge of the ultrastructures of the gels has been elusive. In this study, we report the characterization of two different polymers used in 2DE: Gelatin, a naturally occurring polymer derived from collagen (protein) and agar, a polymer of polysaccharide (sugar) origin. Low-temperature SEM is used to examine the internal structure of these gels in their frozen natural hydrated states. Results of this study show that both polymers have an array of hollow cells that resembles honeycomb structures. While agar pores are almost circular, the corresponding Gaussian curve is very broad exhibiting a range of radii from nearly 370 to 700 nm. Gelatin pores are smaller and more homogeneous reflecting a narrower distribution from nearly 320 to 650 nm. Overall, these ultrastructural findings could be used to correlate with functions of the polymers. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Characterization of internal structure of hydrated agar and gelatin matrices by cryo-SEM.

    Science.gov (United States)

    Rahbani, Janane; Behzad, Ali R; Khashab, Niveen M; Al-Ghoul, Mazen

    2013-02-01

    There has been a considerable interest in recent years in developing polymer gel matrices for many important applications such as 2DE for quantization and separation of a variety of proteins and drug delivery system to control the release of active agents. However, a well-defined knowledge of the ultrastructures of the gels has been elusive. In this study, we report the characterization of two different polymers used in 2DE: Gelatin, a naturally occurring polymer derived from collagen (protein) and agar, a polymer of polysaccharide (sugar) origin. Low-temperature SEM is used to examine the internal structure of these gels in their frozen natural hydrated states. Results of this study show that both polymers have an array of hollow cells that resembles honeycomb structures. While agar pores are almost circular, the corresponding Gaussian curve is very broad exhibiting a range of radii from nearly 370 to 700 nm. Gelatin pores are smaller and more homogeneous reflecting a narrower distribution from nearly 320 to 650 nm. Overall, these ultrastructural findings could be used to correlate with functions of the polymers. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. An electrochemical approach to monitor pH change in agar media during plant tissue culture.

    Science.gov (United States)

    Wang, Min; Ha, Yang

    2007-05-15

    In this work, metal oxide microelectrodes were developed to monitor pH change in agar media during plant tissue culture. An antimony wire was produced by a new approach "capillary melt method". The surface of the obtained antimony wire was oxidized in a potassium nitrate melt to fabricate an antimony oxide film for pH sensing. Characterization results show that the oxide layer grown on the wire surface consists of Sb(2)O(3) crystal phase. The sensing response, open-circuit potential, of the electrode has a good linear relationship (R(2)=1.00) with pH value of the test solution. Adding organic compounds into the test media would not affect the linear relationship, although the slope of the lines varied with different ingredients added. The antimony oxide electrodes were employed to continuously monitor pH change of agar culture media during a 2-week plant tissue culture of Dendrobium candidum. The antimony oxide electrode fabricated this way has the advantages of low cost, easy fabrication, fast response, and almost no contamination introduced into the system. It would be suitable for in situ and continuous pH measurement in many bio applications.

  12. Evaluation of a Modified Cefsulodin-Irgasan-Novobiocin Agar for Isolation of Yersinia spp

    Science.gov (United States)

    Tan, Lai Kuan; Ooi, Peck Toung; Carniel, Elisabeth; Thong, Kwai Lin

    2014-01-01

    Y. enterocolitica and Y. pseudotuberculosis are important food borne pathogens. However, the presence of competitive microbiota makes the isolation of Y. enterocolitica and Y. pseudotuberculosis from naturally contaminated foods difficult. We attempted to evaluate the performance of a modified Cefsulodin-Irgasan-Novobiocin (CIN) agar in the differentiation of Y. enterocolitica from non-Yersinia species, particularly the natural intestinal microbiota. The modified CIN enabled the growth of Y. enterocolitica colonies with the same efficiency as CIN and Luria-Bertani agar. The detection limits of the modified CIN for Y. enterocolitica in culture medium (10 cfu/ml) and in artificially contaminated pork (104 cfu/ml) were also comparable to those of CIN. However, the modified CIN provided a better discrimination of Yersinia colonies from other bacteria exhibiting Yersinia-like colonies on CIN (H2S-producing Citrobacter freundii, C. braakii, Enterobacter cloacae, Aeromonas hydrophila, Providencia rettgeri, and Morganella morganii). The modified CIN exhibited a higher recovery rate of Y. enterocolitica from artificially prepared bacterial cultures and naturally contaminated samples compared with CIN. Our results thus demonstrated that the use of modified CIN may be a valuable means to increase the recovery rate of food borne Yersinia from natural samples, which are usually contaminated by multiple types of bacteria. PMID:25170941

  13. Colonyzer: automated quantification of micro-organism growth characteristics on solid agar

    Directory of Open Access Journals (Sweden)

    Young Alexander

    2010-05-01

    Full Text Available Abstract Background High-throughput screens comparing growth rates of arrays of distinct micro-organism cultures on solid agar are useful, rapid methods of quantifying genetic interactions. Growth rate is an informative phenotype which can be estimated by measuring cell densities at one or more times after inoculation. Precise estimates can be made by inoculating cultures onto agar and capturing cell density frequently by plate-scanning or photography, especially throughout the exponential growth phase, and summarising growth with a simple dynamic model (e.g. the logistic growth model. In order to parametrize such a model, a robust image analysis tool capable of capturing a wide range of cell densities from plate photographs is required. Results Colonyzer is a collection of image analysis algorithms for automatic quantification of the size, granularity, colour and location of micro-organism cultures grown on solid agar. Colonyzer is uniquely sensitive to extremely low cell densities photographed after dilute liquid culture inoculation (spotting due to image segmentation using a mixed Gaussian model for plate-wide thresholding based on pixel intensity. Colonyzer is robust to slight experimental imperfections and corrects for lighting gradients which would otherwise introduce spatial bias to cell density estimates without the need for imaging dummy plates. Colonyzer is general enough to quantify cultures growing in any rectangular array format, either growing after pinning with a dense inoculum or growing with the irregular morphology characteristic of spotted cultures. Colonyzer was developed using the open source packages: Python, RPy and the Python Imaging Library and its source code and documentation are available on SourceForge under GNU General Public License. Colonyzer is adaptable to suit specific requirements: e.g. automatic detection of cultures at irregular locations on streaked plates for robotic picking, or decreasing analysis time by

  14. The effect of magnetic nanoparticles on the acoustic properties of tissue-mimicking agar-gel phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Józefczak, A., E-mail: aras@amu.edu.pl [Institute of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Kaczmarek, K. [Institute of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Kubovčíková, M. [Institute of Experimental Physics, Slovak Academy of Sciences, Košice (Slovakia); Rozynek, Z.; Hornowski, T. [Institute of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland)

    2017-06-01

    In ultrasonic hyperthermia, ultrasound-induced heating is achieved by the absorption of wave energy and its conversion into heat. The effectiveness of ultrasounds can be improved by using sonosensitisers that greatly attenuate ultrasonic waves and then dissipate the acquired energy in the form of heat. One possible candidate for such a sonosensitiser are superparamagnetic iron oxide nanoparticles. Here, we used magnetic nanoparticles embedded in a tissue-mimicking agar-gel matrix. Such tissue-mimicking phantoms possess acoustic properties similar to those of real tissues, and are used as a tool for performance testing and optimisation of medical ultrasound systems. In this work, we studied the effect of magnetic nanoparticles on the acoustic properties of agar-gel phantoms, including the attenuation of ultrasonic waves. - Highlights: • Ultrasonic insertion technique is used to study acoustic properties of agar-gel phantoms with and without magnetic particles. • The addition of magnetic nanoparticles improves effectiveness of ultrasound heating in agar phantoms. • Acoustics properties of a pure agar-gel phantom are altered by adding nanoparticles.

  15. Diffusion of manganese ions in agar gel containing alkali metal chlorides

    International Nuclear Information System (INIS)

    Borhade, A.V.

    2000-01-01

    The obstruction effect for tracer-diffusion of Mn 2+ ions in the presence of different supporting electrolytes (LiCl, NaCl, KCl, CsCl) at various concentrations has been studied at 25 deg C using the zone diffusion technique. It has been observed that the obstruction effect determined in terms of α increases with concentration of the electrolyte. Further, for a given concentration it is found to decrease with increasing charge density of the cation. We also report here on the effect of temperature on obstruction and found that is constant over the temperature range studied (25-45 deg C). These observations are explained on the basis of competitive hydration between ions and agar macromolecules. (author)

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

    Science.gov (United States)

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

    2015-08-01

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

  17. Perfect state of Cryptococcus neoformans, Filobasidiella neoformans, on pigeon manure filtrate agar

    Energy Technology Data Exchange (ETDEWEB)

    Staib, F.

    1981-02-01

    To enable studies of the dependence of Cryptococcus neoformans and its perfect and imperfect states upon bird manure as a habitat of this pathogen, a nutrient medium closely resembling natural conditions was prepared. As sole nutrient, the water soluble ingredients of manure from pigeons (Columbia livia) were used. There was no heat sterilization of the manure filtrate. Using a standard pair of C. neoformans strains for mating, it could be demonstrated that the perfect state of the fungus developed on this so called pigeon manure filtrate agar within 48 h at 26 degrees C. This medium is supposed to help in the elucidation of the epidemiological significance of the perfect and imperfect states of this pathogen.

  18. Agar hydrogel with silver nanoparticles to prolong the shelf life of Fior di Latte cheese.

    Science.gov (United States)

    Incoronato, A L; Conte, A; Buonocore, G G; Del Nobile, M A

    2011-04-01

    The objective of this work was to evaluate the effectiveness of an antimicrobial packaging system containing active nanoparticles on the quality deterioration of Fior di Latte cheese. To this aim, 3 concentrations of silver montmorillonite embedded in agar were used. The cell loads of spoilage and useful microorganisms were monitored during a refrigerated storage period. Moreover, cheese sensory quality (i.e., odor, color, consistency, and overall quality) was evaluated by means of a panel test. Results showed that the active packaging system markedly increased the shelf life of Fior di Latte cheese, due to the ability of silver cations to control microbial proliferation, without affecting the functional dairy microbiota and the sensory characteristics of the product. The active packaging system developed in this work could be used to prolong the shelf life of Fior di Latte and boost its distribution beyond local market borders. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  19. Diagnostic Value of Processing Cytologic Aspirates of Renal Tumors in Agar Cell (Tissue) Blocks

    DEFF Research Database (Denmark)

    Smedts, F.; Schrik, M.; Horn, T.

    2010-01-01

    smears were prepared after each aspiration for conventional cytology and the remaining aspirate was processed for the improved agar microbiopsy (AM) method. Conventional cytology slides, AM slides and surgical specimens were diagnosed separately, after which the diagnoses were compared....... Immunohistochemistry was performed as required on the AM sections. Surgical specimens served as the gold standard. Results In 53% of conventional cytologic smears, the cellular yield was sufficient to render a correct diagnosis. In 12% the diagnosis was incorrect, in 21% only a differential diagnosis could be fin......-initiated, and in 14% too few diagnostic cells were present in the conventional smears for cytologic diagnosis. It was, however, possible to correctly diagnose histologic sections from 97% of AM tissue blocks. In 11 cases this was facilitated with immunochemistry. In only 1 case did the AM tissue block contain too few...

  20. Optimasi Waktu Proses Hidrolisis dan Fermentasi dalam Produksi Bioetanol dari Limbah Pengolahan Agar (Gracilaria sp. Industri

    Directory of Open Access Journals (Sweden)

    Rodiah Nurbaya Sari

    2013-12-01

    menggunakan kapang Trichoderma viride dan khamir Saccharomyces cerevisiae. Penelitian yang dilakukan terdiri dari beberapa tahap yaitu karakterisasi limbah agar industri, hidrolisis enzimatis menggunakan kapang Trichoderma viride penghasil selulase, dan fermentasi dengan khamir Saccharomyces cerevisiae. Hasilnya menunjukkan bahwa waktu optimal untuk hidrolisis enzimatis adalah 4 hari pada suhu 28 oC dan pH 3,91; aktivitas CMCase 210,48 IU/ml dan menghasilkan total gula pereduksi 6,74 mg/ml. Sedangkan untuk waktu fermentasi yang optimal adalah 2 hari pada suhu 32 oC dan pH 4,66 dengan nilai OD 600 nm 0,0181 menghasilkan etanol kasar dengan kadar 0,47% (b/b.

  1. The presence of embedded bacterial pure cultures in agar plates stimulate the culturability of soil bacteria

    DEFF Research Database (Denmark)

    Burmølle, Mette; Johnsen, Kaare; Abu Al-Soud, Waleed Mohamad Abdel F

    2009-01-01

    Traditional methods for bacterial cultivation recover only a small fraction of bacteria from all sorts of natural environments, and attempts have been made to improve the bacterial culturability. Here we describe the development of a cultivation method, based on the embedment of pure bacterial...... cultures in between two layers of agar. Plates containing either embedded Pseudomonas putida or Arthrobacter globiformis resulted in higher numbers of CFUs of soil bacteria (21% and 38%, respectively) after 833 h of incubation, compared to plates with no embedded strain. This indicates a stimulatory effect...... of the bacterial pure cultures on the cultivation of soil bacteria. Analysis of partial 16S rRNA gene sequences revealed a phylogenetical distribution of the soil isolates into 7 classes in 4 phyla. No difference was observed at the phylum or class level when comparing isolates grouped according to embedded strain...

  2. Cytotoxicity of dental alloys, metals, and ceramics assessed by millipore filter, agar overlay, and MTT tests.

    Science.gov (United States)

    Sjögren, G; Sletten, G; Dahl, J E

    2000-08-01

    Biocompatibility of dental materials is dependent on the release of elements from the materials. In addition, the composition, pretreatment, and handling of the materials influence the element release. This study evaluated the cytotoxicity of dental alloys, metals, and ceramics, with specific emphasis on the effects of altering the composition and the pretreatment. By using cells from a mouse fibroblast cell line and the agar overlay test, Millipore filter test, and MTT test, cytotoxicity of various metals, metal alloys, and ceramics for dental restoration were studied. Effects of altering the composition of a high noble gold alloy and of pretreatment of a ceramic-bonding alloy were also studied. In addition, the release of elements into the cell culture medium by the materials studied was measured using an inductively coupled plasma optical emission spectrophotometer. The results of the MTT test were analyzed statistically using ANOVA and Scheffé test at a significance level of P filter tests. For the MTT test, no significant differences were observed between these materials and controls, with the exception of JS C-gold and unalloyed titanium. The modified materials were ranked from "mildly cytotoxic" to "moderately cytotoxic" in the agar overlay and Millipore filter tests and from "noncytotoxic" to "moderately cytotoxic" in the MTT test. Thus, cytotoxicity was related to the alloy composition and treatment. The release of Cu and Zn seemed to be important for the cytotoxic effect. Alterations in the composition and the pretreatment can greatly influence the cytotoxicity, and the results stress the importance of carefully following the manufacturers' instructions when handling dental materials.

  3. Effects of Antifungal Soaked Silicone Hydrogel Contact Lenses on Candida albicans in an Agar Eye Model.

    Science.gov (United States)

    Phan, Chau-Minh; Bajgrowicz, Magdalena; McCanna, David J; Subbaraman, Lakshman N; Jones, Lyndon

    2016-09-01

    To evaluate the effects of two commercial silicone hydrogel contact lenses (CLs) soaked with natamycin (NA) or fluconazole (FL) on the growth of Candida albicans in an in vitro eye model. Three-D printed molds were used as a cast for making eye-shaped models comprising potato dextrose agar. Senofilcon A (SA) and lotrafilcon B (LB) CLs were incubated with either 2 mL of NA or FL at a concentration of 1 mg/mL for 24 hr. To simulate a fungal infection, the eye models were coated with C. albicans. The drug-soaked lenses were placed on top of the eye models. Seven experimental conditions were examined: (1) NA-SA, (2) NA-LB, (3) FL-SA, (4) FL-LB, (5) SA, (6) LB, and (7) control-no lens. At specified time points (t=1, 8, 16, 24, 48 hr), the agar eyes from each experimental condition were removed from the incubator and photographed. The yeast cells from the 24 and 48 hr time point were also analyzed using light microscopy. At 24 and 48 hr, there was considerable growth observed for all conditions except for the NA-SA and NA-LB conditions. When observed under the microscope at 24 and 48 hr, the morphology of the yeast cells in the FL-SA and SA condition were similar to that of the control (oval shaped). There was limited hyphae growth observed for LB and significant visible hyphae growth for the NA-LB group. For NA-SA, NA-LB, and FL-LB groups, the cells were significantly smaller compared with the control. For NA-SA and NA-LB, there was limited growth of C. albicans observed on the eye models even after 48 hr. Under the microscope, the cell morphology differ noticeably between each testing condition, and is dependent on drug-lens combinations.

  4. Copper removal by algae Gelidium, agar extraction algal waste and granulated algal waste: kinetics and equilibrium.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2008-03-01

    Biosorption of copper ions by an industrial algal waste, from agar extraction industry has been studied in a batch system. This biosorbent was compared with the algae Gelidium itself, which is the raw material for agar extraction, and the industrial waste immobilized with polyacrylonitrile (composite material). The effects of contact time, pH, ionic strength (IS) and temperature on the biosorption process have been studied. Equilibrium data follow both Langmuir and Langmuir-Freundlich models. The parameters of Langmuir equilibrium model were: q(max)=33.0mgg(-1), K(L)=0.015mgl(-1); q(max)=16.7mgg(-1), K(L)=0.028mgl(-1) and q(max)=10.3mgg(-1), K(L)=0.160mgl(-1) respectively for Gelidium, algal waste and composite material at pH=5.3, T=20 degrees C and IS=0.001M. Increasing the pH, the number of deprotonated active sites increases and so the uptake capacity of copper ions. In the case of high ionic strengths, the contribution of the electrostatic component to the overall binding decreases, and so the uptake capacity. The temperature has little influence on the uptake capacity principally for low equilibrium copper concentrations. Changes in standard enthalpy, Gibbs energy and entropy during biosorption were determined. Kinetic data at different solution pH (3, 4 and 5.3) were fitted to pseudo-first-order and pseudo-second-order models. The adsorptive behaviour of biosorbent particles was modelled using a batch reactor mass transfer kinetic model, which successfully predicts Cu(II) concentration profiles.

  5. Zinc-air cell with KOH-treated agar layer between electrode and electrolyte containing hydroponics gel

    Energy Technology Data Exchange (ETDEWEB)

    Otham, R. [International Islamic University, Kuala Lumpur (Malaysia); Yahaya, A. H. [University of Malaya, Dept. of Chemistry, Kuala Lumpur (Malaysia); Arof, A. K. [University of Malaya, Dept. of Physics, Kuala Lumpur (Malaysia)

    2002-07-01

    Zinc-air electrochemical power sources possess the highest density compared to other zinc anode batteries, due their free and unlimited supply from the ambient air. In this experiment zinc-air cells have been fabricated employing hydroponics gel as an alternative alkaline electrolyte gelling agent. Thin KOH-treated agar layer was applied between the electrode-electrolyte interfaces which produced significant enhancement of the cells' capacities, indicating that the application of thin agar layer will improve the electrode-gelled electrolyte interfaces. Promising results have been achieved with porous zinc anode prepared from dried zinc-graphite-gelatinized agar paste; e g. a zinc-air cell employing a porous zinc anode has demonstrated a capacity of 1470 mAh rated at 0.1 A continuous discharge. 32 refs., 9 figs.

  6. Hair sheep blood, citrated or defibrinated, fulfills all requirements of blood agar for diagnostic microbiology laboratory tests.

    Science.gov (United States)

    Yeh, Ellen; Pinsky, Benjamin A; Banaei, Niaz; Baron, Ellen Jo

    2009-07-03

    Blood agar is used for the identification and antibiotic susceptibility testing of many bacterial pathogens. In the developing world, microbiologists use human blood agar because of the high cost and inhospitable conditions for raising wool sheep or horses to supply blood. Many pathogens either fail to grow entirely or exhibit morphologies and hemolytic patterns on human blood agar that confound colony recognition. Furthermore, human blood can be hazardous to handle due to HIV and hepatitis. This study investigated whether blood from hair sheep, a hardy, low-maintenance variety of sheep adapted for hot climates, was suitable for routine clinical microbiology studies. Hair sheep blood obtained by jugular venipuncture was anticoagulated by either manual defibrination or collection in human blood bank bags containing citrate-phosphate-dextrose. Trypticase soy 5% blood agar was made from both forms of hair sheep blood and commercial defibrinated wool sheep blood. Growth characteristics, colony morphologies, and hemolytic patterns of selected human pathogens, including several streptococcal species, were evaluated. Specialized identification tests, including CAMP test, reverse CAMP test, and satellite colony formation with Haemophilus influenzae and Abiotrophia defectiva were also performed. Mueller-Hinton blood agar plates prepared from the three blood types were compared in antibiotic susceptibility tests by disk diffusion and E-test. The results of all studies showed that blood agar prepared from citrated hair sheep blood is suitable for microbiological tests used in routine identification and susceptibility profiling of human pathogens. The validation of citrated hair sheep blood eliminates the labor-intensive and equipment-requiring process of manual defibrination. Use of hair sheep blood, in lieu of human blood currently used by many developing world laboratories and as an alternative to cost-prohibitive commercial sheep blood, offers the opportunity to

  7. Hair sheep blood, citrated or defibrinated, fulfills all requirements of blood agar for diagnostic microbiology laboratory tests.

    Directory of Open Access Journals (Sweden)

    Ellen Yeh

    Full Text Available BACKGROUND: Blood agar is used for the identification and antibiotic susceptibility testing of many bacterial pathogens. In the developing world, microbiologists use human blood agar because of the high cost and inhospitable conditions for raising wool sheep or horses to supply blood. Many pathogens either fail to grow entirely or exhibit morphologies and hemolytic patterns on human blood agar that confound colony recognition. Furthermore, human blood can be hazardous to handle due to HIV and hepatitis. This study investigated whether blood from hair sheep, a hardy, low-maintenance variety of sheep adapted for hot climates, was suitable for routine clinical microbiology studies. METHODS AND FINDINGS: Hair sheep blood obtained by jugular venipuncture was anticoagulated by either manual defibrination or collection in human blood bank bags containing citrate-phosphate-dextrose. Trypticase soy 5% blood agar was made from both forms of hair sheep blood and commercial defibrinated wool sheep blood. Growth characteristics, colony morphologies, and hemolytic patterns of selected human pathogens, including several streptococcal species, were evaluated. Specialized identification tests, including CAMP test, reverse CAMP test, and satellite colony formation with Haemophilus influenzae and Abiotrophia defectiva were also performed. Mueller-Hinton blood agar plates prepared from the three blood types were compared in antibiotic susceptibility tests by disk diffusion and E-test. CONCLUSIONS: The results of all studies showed that blood agar prepared from citrated hair sheep blood is suitable for microbiological tests used in routine identification and susceptibility profiling of human pathogens. The validation of citrated hair sheep blood eliminates the labor-intensive and equipment-requiring process of manual defibrination. Use of hair sheep blood, in lieu of human blood currently used by many developing world laboratories and as an alternative to cost

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

    Science.gov (United States)

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

    1985-07-01

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

  9. Variation in the excitability of developed D. discoideum cells as a function of agar concentration in the substrate

    Science.gov (United States)

    Oikawa, Noriko; Bae, Albert; Amselem, Gabriel; Bodenschatz, Eberhard

    2010-03-01

    In the absence of nutrients, Dictyostelium discoideum cells enter a developmental cycle--they signal each other, aggregate, and ultimately form fruiting bodies. During the signaling stage, the cells relay waves of cyclic adenosine 3',5' monophosphate (cAMP). We observed a transition from spiral to circular patterns in the signaling wave, depending on the agar concentration of the substrate. In this talk we will present the changes in the times for the onset of signaling and synchronization versus agar concentration, as measured by spectral entropy. We also will discuss the origin of these effects.

  10. Extracción, identificación y prueba microbiológica del agar extraído de Gracilaria fortissima dawson (rhodophyta, gigartinales, gracilariaceae (ING

    Directory of Open Access Journals (Sweden)

    M.V. Sánchez

    2016-03-01

    Full Text Available The red seaweed Gracilaria fortissima colected in the caribean coast of Costa Rica, was studied for the extraction, identification and microbiological performance of the agar contend of this plant, as well as the mineral contend. The research was done focused on the agar quality included pH, % extraction, geling point, fusion point and gel strength, as well as infrared analysis and the performance as a microbiological culture of bacteria and fungus and compared with commercial agar from BDH chemicals.

  11. Comparison of Neisseria gonorrhoeae MICs Obtained by Etest and Agar Dilution for Ceftriaxone, Cefpodoxime, Cefixime and Azithromycin.

    Science.gov (United States)

    Gose, Severin; Kong, Carol J; Lee, Yer; Samuel, Michael C; Bauer, Heidi M; Dixon, Paula; Soge, Olusegun O; Lei, John; Pandori, Mark

    2013-10-24

    We evaluated Neisseria gonorrhoeae Etest minimum inhibitory concentrations (MICs) relative to agar dilution MICs for 664 urethral isolates for ceftriaxone (CRO) and azithromycin (AZM), 351 isolates for cefpodoxime (CPD) and 315 isolates for cefixime (CFM). Etest accurately determined CPD, CFM and AZM MICs, but resulted in higher CRO MICs. © 2013. Published by Elsevier B.V. All rights reserved.

  12. Agar Plates Made from Common Supermarket Substances and Bacillus subtilis Natto as an Inexpensive Approach to Microbiology Education

    Directory of Open Access Journals (Sweden)

    Franz-Josef Scharfenberg

    2015-08-01

    Full Text Available To address the possible limitations that financial restrictions may have on students’ independent experimentation at school, we developed and implemented an inexpensive approach for basic microbiology education. We describe four nutrient agars consisting only of everyday substances available from the supermarket or online that we developed to replace standard agars and specific agars. Additionally, we selected Bacillus subtilis natto as an example of a pure-culture species. Our tip first reports the four supermarket-substance agar variants; second, it suggests utilizing them to introduce basic microbiological techniques; and third, it introduces B. subtilis natto in the context of the antibacterial effects of antibiotics as well as of supermarket products which students can bring to class from home. We implemented our approach in microbiology education at school as well as in pre-service teacher education and in in-service teacher professional development courses at our university. Finally, our paper provides worksheets for all the experiments. Editor's Note:The ASM advocates that students must successfully demonstrate the ability to explain and practice safe laboratory techniques. For more information, read the laboratory safety section of the ASM Curriculum Recommendations: Introductory Course in Microbiology and the Guidelines for Biosafety in Teaching Laboratories, available at www.asm.org. The Editors of JMBE recommend that adopters of the protocols included in this article follow a minimum of Biosafety Level 1 practices. If the soil plates described in the activity are opened, a minimum of Biosafety Level 2 is required.

  13. Choline chloride based ionic liquid analogues as tool for the fabrication of agar films with improved mechanical properties

    Science.gov (United States)

    In the present paper, we test the suitability of Choline-Cl/urea (DES-U) and Choline-Cl/glycerol (DES-G) eutectic mixtures at 1:2 molar ratios for the production of agar biodegradable films. A three-step process is proposed: pre-solubilization of polymer in DES followed by compression-molding and s...

  14. Detection of Fusobacterium nucleatum in two cases of empyema and lung abscess using paromomycin-vancomycin supplemented Brucella HK agar.

    Science.gov (United States)

    Nagaoka, Kentaro; Yanagihara, Katsunori; Morinaga, Yoshitomo; Kohno, Shigeru

    2017-02-01

    Fusobacterium nucleatum was found in patients with empyema or pulmonary abscess, using paromomycin-vancomycin Brucella HK agar. In vitro examination revealed that growth of the strains differed significantly in different media. Clinicians should be aware that suboptimal F. nucleatum cultivation methods may result in an underestimation of its frequency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Effects of immersion disinfection of agar-alginate combined impressions on the surface properties of stone casts.

    Science.gov (United States)

    Iwasaki, Yukiko; Hiraguchi, Hisako; Iwasaki, Eriko; Yoneyama, Takayuki

    2016-01-01

    This study investigated the effects of disinfection of agar-alginate combined impressions on the surface properties of the resulting stone casts. Two brands of cartridge-form agar impression material and one alginate impression material were used. Agar-alginate combined impressions of smooth glass plates were prepared. The impressions were immersed in 0.55% ortho-phthalaldehyde solution or 0.5% sodium hypochlorite solution for 1, 3, 5 and 10 min. A stone cast made with an impression that had not been immersed was prepared as a control. The surface roughness (Ra) of the stone casts was measured, and the cast surfaces were observed by SEM. Immersion of agar-alginate combined impressions in 0.5% sodium hypochlorite solution for up to 10 min had no serious adverse effects on the surface properties of the stone casts. In contrast, even 1 min of immersion in 0.55% ortho-phthalaldehyde solution caused deterioration of the cast surface properties.

  16. Agar/gelatin bilayer gel matrix fabricated by simple thermo-responsive sol-gel transition method.

    Science.gov (United States)

    Wang, Yifeng; Dong, Meng; Guo, Mengmeng; Wang, Xia; Zhou, Jing; Lei, Jian; Guo, Chuanhang; Qin, Chaoran

    2017-08-01

    We present a simple and environmentally-friendly method to generate an agar/gelatin bilayer gel matrix for further biomedical applications. In this method, the thermally responsive sol-gel transitions of agar and gelatin combined with the different transition temperatures are exquisitely employed to fabricate the agar/gelatin bilayer gel matrix and achieve separate loading for various materials (e.g., drugs, fluorescent materials, and nanoparticles). Importantly, the resulting bilayer gel matrix provides two different biopolymer environments (a polysaccharide environment vs a protein environment) with a well-defined border, which allows the loaded materials in different layers to retain their original properties (e.g., magnetism and fluorescence) and reduce mutual interference. In addition, the loaded materials in the bilayer gel matrix exhibit an interesting release behavior under the control of thermal stimuli. Consequently, the resulting agar/gelatin bilayer gel matrix is a promising candidate for biomedical applications in drug delivery, controlled release, fluorescence labeling, and bio-imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. [Thin layer agar represents a cost-effective alternative for the rapid diagnosis of multi-drug resistant tuberculosis].

    Science.gov (United States)

    Hernández-Sarmiento, José M; Martínez-Negrete, Milton A; Castrillón-Velilla, Diana M; Mejía-Espinosa, Sergio A; Mejía-Mesa, Gloria I; Zapata-Fernández, Elsa M; Rojas-Jiménez, Sara; Marín-Castro, Andrés E; Robledo-Restrepo, Jaime A

    2014-01-01

    Using cost-benefit analysis for comparing the thin-layer agar culture method to the standard multiple proportion method used in diagnosing multidrug-resistant tuberculosis (MDR TB). A cost-benefit evaluation of two diagnostic tests was made at the Corporación para Investigaciones Biológicas (CIB) in Medellín, Colombia. 100 patients were evaluated; 10.8% rifampicin resistance and 14.3% isoniazid resistance were found. A computer-based decision tree model was used for cost-effectiveness analysis (Treeage Pro); the thin-layer agar culture method was most cost-effective, having 100% sensitivity, specificity and predictive values for detecting rifampicin and isoniazid resistance. The multiple proportion method value was calculated as being US$ 71 having an average 49 day report time compared to US$ 18 and 14 days for the thin-layer agar culture method. New technologies have been developed for diagnosing tuberculosis which are apparently faster and more effective; their operating characteristics must be evaluated as must their effectiveness in terms of cost-benefit. The present study established that using thin-layer agar culture was cheaper, equally effective and could provide results more quickly than the traditional method. This implies that a patient could receive MDR TB treatment more quickly.

  18. Evaluatie van de membraanfiltratiemethode op mCP-agar voor bepaling van sporen van Clostridium perfringens in water

    NARCIS (Netherlands)

    Schets FM; Medema GJ; LWL

    1995-01-01

    Current Dutch and European drinking water standards include criteria for spores of sulphite reducing clostridia. This has some inherent disadvantages. The reproducibility of the enumeration method for spores of sulphite reducing clostridia (SSRC) in Sulphite Cycloserine Agar (SCA) is poor. Some

  19. A simple agar plate preparation for effective transfer of Ureaplasma colonies onto nitrocellulose membranes for colony immunoblotting.

    Science.gov (United States)

    Zimmerman, Carl-Ulrich R; Stiedl, Thomas; Spergser, Joachim; Rosengarten, Renate

    2014-09-01

    A simple method for preparing agar plates is presented, which allows an efficient transfer of Ureaplasma colonies to nitrocellulose membranes for subsequent immunological detection. This simple and reproducible procedure was used to demonstrate antigenic variation in the phase-variable mba-locus of Ureaplasma parvum serovar 3. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Development and Validation of a Microbiological Agar Assay for Determination of Orbifloxacin in Pharmaceutical Preparations

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    Hérida R. N. Salgado

    2011-08-01

    Full Text Available Orbifloxacin is a fluoroquinolone with broad-spectrum antimicrobial activity, and belongs to the third generation of quinolones. Regarding the quality control of medicines, a validated microbiological assay for determination of orbifloxacin in pharmaceutical formulations has not as yet been reported. For this purpose, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method to quantify orbifloxacin in tablet formulations. The assay is based on the inhibitory effect of orbifloxacin upon the strain of Staphylococcus aureus ATCC 25923 used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear (r = 0.9992 in the selected range of 16.0–64.0 μg/mL, precise with relative standard deviation (RSD of repeatability intraday = 2.88%, intermediate precision RSD = 3.33%, and accurate (100.31%. The results demonstrated the validity of the proposed bioassay, which allows reliable orbifloxacin quantitation in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine.

  1. Hypertonic sabouraud dextrose agar as a substrate for differentiation of Candida dubliniensis.

    Science.gov (United States)

    Akgül, Oncü; Cerikçioğlu, Nilgün

    2009-06-01

    In this study, we aimed to detect the proportion of Candida dubliniensis among yeast strains previously identified as C. albicans by using several phenotypic methods and PCR.For this purpose, we screened 300 strains by using phenotypic tests suggested for the identification of C. dubliniensis in the literature, but we detected high proportion of false-positive reactions. Only two strains (0.6%) were detected as true C. dubliniensis by PCR and API ID 32C methods. Moreover, these two strains gave the expected results with all the phenotypic tests, including modified salt tolerance test for C. dubliniensis.In conclusion, none of the phenotypic methods, except for the modified salt tolerance test, revealed 100% successful results in discrimination of C. albicans and C. dubliniensis species. However, in the tobacco agar test, the rate of false positivity was as low as 0.6%. We suggest that in the case of absence of PCR and other automatized identification systems, these two phenotypic tests can be used in routine laboratories to obtain a presumptive result.

  2. Internal properties assessment in agar wood trees using ultrasonic velocity measurement

    International Nuclear Information System (INIS)

    Mohd Noorul Ikhsan Mohamed; Mohamad Pauzi Ismail; Mat Rasol Awang; Mohd Fajri Osman; Fakhruzi, M.; Hashim, M.M.

    2010-01-01

    This paper presents the application of ultrasonic velocity in agar wood trees (Aquilaria crassna) with the purpose of evaluating the relationship of the ultrasonic velocity to the variations of internal properties of trees. In this study, three circular cross-sectional discs from the freshly cut tree were selected as samples. First sample with a big hole (decay) in the middle, second sample with internal resinous and the last one is the sample with no defects. The through transmission ultrasonic testing method was carried out using Tico ultrasonic pulse velocity tester which is from Switzerland. Two-dimensional image of internal properties evaluation by an ultrasonic investigation was obtained using Matlab. The results showed that the ultrasonic wave cannot pass through the internal decay or resinous so that the wave went round it and thus ultrasonic wave velocity significantly decreased by increasing the hole or resinous. The difference in color of the image generated by Matlab software based on variation of ultrasonic velocity between the internal decay area and its surrounding area was obvious. Therefore, the properties of internal properties of the three could be detected by ultrasonic line imaging technique. (author)

  3. Functional properties of edible agar-based and starch-based films for food quality preservation.

    Science.gov (United States)

    Phan, The D; Debeaufort, F; Luu, D; Voilley, A

    2005-02-23

    Edible films made of agar (AG), cassava starch (CAS), normal rice starch (NRS), and waxy (glutinous) rice starch (WRS) were elaborated and tested for a potential use as edible packaging or coating. Their water vapor permeabilities (WVP) were comparable with those of most of the polysaccharide-based films and with some protein-based films. Depending on the environmental moisture pressure, the WVP of the films varies and remains constant when the relative humidity (RH) is >84%. Equilibrium sorption isotherms of these films have been measured; the Guggenheim-Anderson-de Boer (GAB) model was used to describe the sorption isotherm and contributed to a better knowledge of hydration properties. Surface hydrophobicity and wettability of these films were also investigated using the sessile drop contact angle method. The results obtained suggested the migration of the lipid fraction toward evaporation surface during film drying. Among these polysaccharide-based films, AG-based film and CAS-based film displayed more interesting mechanical properties: they are transparent, clear, homogeneous, flexible, and easily handled. NRS- and WRS-based films were relatively brittle and have a low tension resistance. Microstructure of film cross section was observed by environmental scanning electron microscopy to better understand the effect of the structure on the functional properties. The results suggest that AG-based film and CAS-based films, which show better functional properties, are promising systems to be used as food packaging or coating instead of NRS- and WRS-based films.

  4. Estimating the Diffusion Coefficients of Sugars Using Diffusion Experiments in Agar-Gel and Computer Simulations.

    Science.gov (United States)

    Miyamoto, Shuichi; Atsuyama, Kenji; Ekino, Keisuke; Shin, Takashi

    2018-01-01

    The isolation of useful microbes is one of the traditional approaches for the lead generation in drug discovery. As an effective technique for microbe isolation, we recently developed a multidimensional diffusion-based gradient culture system of microbes. In order to enhance the utility of the system, it is favorable to have diffusion coefficients of nutrients such as sugars in the culture medium beforehand. We have, therefore, built a simple and convenient experimental system that uses agar-gel to observe diffusion. Next, we performed computer simulations-based on random-walk concepts-of the experimental diffusion system and derived correlation formulas that relate observable diffusion data to diffusion coefficients. Finally, we applied these correlation formulas to our experimentally-determined diffusion data to estimate the diffusion coefficients of sugars. Our values for these coefficients agree reasonably well with values published in the literature. The effectiveness of our simple technique, which has elucidated the diffusion coefficients of some molecules which are rarely reported (e.g., galactose, trehalose, and glycerol) is demonstrated by the strong correspondence between the literature values and those obtained in our experiments.

  5. Acidity Tunable Ionic Liquids as Catalysts for Conversion of Agar into Mixed Sugars

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Churl; Kim, Hoon Sik [Kyung Hee Univ., Seoul (Korea, Republic of); Ryu, Hyun Jin; Kim, Sang Hyoun; Yoon, Jeong Jun; Kim, Yong Jin [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of)

    2010-02-15

    To summarize, various factors affecting yields of Gal, AG, and 5-HMF formation during saccharification were investigated using agar as a substrate in the presence of several bisulfate-based acidic ionic liquids as catalysts. The result was compared with employing sulfuric acid from the viewpoint of sugar yields and 5-HMF formation. [Bmim][HSO{sub 4}], [Hmim][HSO{sub 4}], [Morph] [HSO{sub 4}], [Bu{sub 4}N][HSO{sub 4}], [Bu{sub 4}P][HSO{sub 4}], [Chol][HSO{sub 4}] showed moderate to high yields of Gal and AG with a remarkable decrease in 5-HMF formation compared with sulfuric acid. Among them, [Chol][HSO{sub 4}] ionic liquid was found to exhibit the highest yield of sugars with an acceptable concentration of 5-HMF that does not inhibit the fermentation process. Generally, there are five major bottom lines for a bioethanol process to be economically viable: the feedstock must be plentiful, inexpensive, in high energy conversion rate, in low demand for food industry, and finally, has to be cultivated in sustainable systems.

  6. Unraveling the nuclear and chloroplast genomes of an agar producing red macroalga, Gracilaria changii (Rhodophyta, Gracilariales).

    Science.gov (United States)

    Ho, Chai-Ling; Lee, Wei-Kang; Lim, Ee-Leen

    2018-03-01

    Agar and agarose have wide applications in food and pharmaceutical industries. Knowledge on the genome of red seaweeds that produce them is still lacking. To fill the gap in genome analyses of these red algae, we have sequenced the nuclear and organellar genomes of an agarophyte, Gracilaria changii. The partial nuclear genome sequence of G. changii has a total length of 35.8Mb with 10,912 predicted protein coding sequences. Only 39.4% predicted proteins were found to have significant matches to protein sequences in SwissProt. The chloroplast genome of G. changii is 183,855bp with a total of 201 open reading frames (ORFs), 29 tRNAs and 3 rRNAs predicted. Five genes: ssrA, leuC and leuD CP76_p173 (orf139) and pbsA were absent in the chloroplast genome of G. changii. The genome information is valuable in accelerating functional studies of individual genes and resolving evolutionary relationship of red seaweeds. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Comparison of three techniques for production goat lentivirus antigen used in the agar gel immunodifusion test

    Directory of Open Access Journals (Sweden)

    Raymundo Rizaldo Pinheiro

    2005-12-01

    Full Text Available The Caprine Arthritis Encephalitis (CAE is a disease who cause considerable economic losses, including loss in the milk production and reduction of the useful life of the animal. In the diagnosis of this disease the agar gel immunodifusion test (AGID is used worldwide as the selection test. The objective of thid work was to test three different concentrations of bovine fetal serum (BFS in the production of the antigen (Ag for the diagnosis of the CAE virus (CAEV, to verify amongst the three methods the most efficient concentration and which the antigen concentration of the antigen produced is appropriate for the test. The method of the AMICON and the concentration of the Ag for dialysis was indicated, however the system AMICON, despite the implantation costs, promoted minor loss of antigen, little time expense in the processing and greater simplicity. With relation to the amount of BFS placed after the viral inoculation it was verified that 5% of BFS the amount that presented better resulted. The antigen concentration 100 times was more indicated, therefore it allowed the diagnosis of the CAEV for two proteins (gp 135 and p28. The concentration of the Ag for precipitation/ultracentrifugation, used for imunoenzimatic tests, did not present resulted satisfactory used in the AGID.

  8. Antimicrobial susceptibility of Brazilian Clostridium difficile strains determined by agar dilution and disk diffusion

    Directory of Open Access Journals (Sweden)

    Edmir Geraldo Fraga

    2016-09-01

    Full Text Available Clostridium difficile is a leading cause of diarrhea in hospitalized patients worldwide. While metronidazole and vancomycin are the most prescribed antibiotics for the treatment of this infection, teicoplanin, tigecycline and nitazoxanide are alternatives drugs. Knowledge on the antibiotic susceptibility profiles is a basic step to differentiate recurrence from treatment failure due to antimicrobial resistance. Because C. difficile antimicrobial susceptibility is largely unknown in Brazil, we aimed to determine the profile of C. difficile strains cultivated from stool samples of inpatients with diarrhea and a positive toxin A/B test using both agar dilution and disk diffusion methods. All 50 strains tested were sensitive to metronidazole according to CLSI and EUCAST breakpoints with an MIC90 value of 2 μg/mL. Nitazoxanide and tigecycline were highly active in vitro against these strains with an MIC90 value of 0.125 μg/mL for both antimicrobials. The MIC90 were 4 μg/mL and 2 μg/mL for vancomycin and teicoplanin, respectively. A resistance rate of 8% was observed for moxifloxacin. Disk diffusion can be used as an alternative to screen for moxifloxacin resistance, nitazoxanide, tigecycline and metronidazole susceptibility, but it cannot be used for testing glycopeptides. Our results suggest that C. difficile strains from São Paulo city, Brazil, are susceptible to metronidazole and have low MIC90 values for most of the current therapeutic options available in Brazil.

  9. Theoretical and experimental NMR studies on muscimol from fly agaric mushroom (Amanita muscaria)

    Science.gov (United States)

    Kupka, Teobald; Wieczorek, Piotr P.

    2016-01-01

    In this article we report results of combined theoretical and experimental NMR studies on muscimol, the bioactive alkaloid from fly agaric mushroom (Amanita muscaria). The assignment of 1H and 13C NMR spectra of muscimol in DMSO-d6 was supported by additional two-dimensional heteronuclear correlated spectra (2D NMR) and gauge independent atomic orbital (GIAO) NMR calculations using density functional theory (DFT). The effect of solvent in theoretical calculations was included via polarized continuum model (PCM) and the hybrid three-parameter B3LYP density functional in combination with 6-311++G(3df,2pd) basis set enabled calculation of reliable structures of non-ionized (neutral) molecule and its NH and zwitterionic forms in the gas phase, chloroform, DMSO and water. GIAO NMR calculations, using equilibrium and rovibrationally averaged geometry, at B3LYP/6-31G* and B3LYP/aug-cc-pVTZ-J levels of theory provided muscimol nuclear magnetic shieldings. The theoretical proton and carbon chemical shifts were critically compared with experimental NMR spectra measured in DMSO. Our results provide useful information on its structure in solution. We believe that such data could improve the understanding of basic features of muscimol at atomistic level and provide another tool in studies related to GABA analogs.

  10. [Variations in hyperbilirrubinemia in low birth weight newborns under phototherapy and continous or discontinous agar oral administration (author's transl)].

    Science.gov (United States)

    Colomer, J; Moya, M; Marco, V; De Paredes, C; Escrivá, F; Vila, R

    1975-06-01

    Therapeutic attitude in hyperbilirrubinemia is always worth because other infrequent complications but not for this, less important. Phototherapy innocuousness, largely demonstrated, fosters its profilactic use at beginning and not only for those babies with serum bilirrubin over 10 mg % in the first day of life. Previously we have reported positive results with agar oral administration without collateral effects. On this grounds we have planned the following experience in a homogenous group of L.B.W.: one group was fed with agar previously to each formula administration; other group received the same amount of agar but divided in only three administrations in 24 hours; the last group received continuous phototherapy for 96 hours with a white cold fluorescent light from a source of 8-Vita-lite lamp of 40 watts with a intensity of 500 foot candle and 30 lumens. All of these babies weighed less than 2.500 g. and were between 10 and 90 percentil of Lubschenko diagram. They were fed with the same formula and same time table with no infusions, rejecting all that presented any type of pathology. Obstetric conditions were basically identical. This population was randomly divided in four groups. 1) Control group with no profilaxis, but with identical bilirrubin andhematocrit determinations. 2) Group with continuous agar oral administration, 125 mg. before each of the seven formula feeding. 3) Group with discontinuous agar administration, 250 mg. before three of the seven formula feeding. 4) Group with continuous phototherapy for 96 hours. These is initial identification of the groups with statistic signification, and after that a quantitative and sequential evolution of bilirrubin is analized in each group.

  11. Analysis of High Quality Agar wood Oil Chemical Compounds By Means Of SPME/ GC-MS and Z-Score Technique

    International Nuclear Information System (INIS)

    Nurlaila Ismail; Mohd Ali Nor Azah; Mailina Jamil; Saiful Nizam Tajuddin; Mohd Nasir Taib

    2013-01-01

    Currently, the grading of the agar wood oil to the high and low quality is done using manually such as human trained grader. It was performed based on the agar wood oil physical properties such as human experience and perception and the oil colour, odor and long lasting aroma. Several researchers found that chemical profiles of the oil should be utilized to overcome the problem facing by manual techniques for example human nose cannot tolerate with the many oils at the same time, so that accurate result can be obtained in grading the agar wood oil. The analysis involved of SPME/ GC-MS and Z-score techniques have been proposed in this study to analyze the chemical compounds especially from the high quality samples of agar wood oil (Aquilariamalaccensis) from Malaysia. Two SPME fibers were used such as divinylbenzene-carbogen-polydimethylsiloxane (DVB-CAR-PDMS) and polydimethylsiloxane (PDMS) in extracting the oils compound under three different sampling temperature conditions such as 40, 60 and 80 degree Celsius. The chemical compounds extracted by SPME/ GC-MS were analyzed. The chemical compounds as identified by Z-score as significant compounds were discussed before the conclusion is made. It was found that 10-epi-γ-eudesmol, aromadendrene, β-agar ofuran, α-agar ofuran and γ-eudesmol were highlighted as significant for high quality agar wood oil and can be used as a marker compounds in classifying the agar wood oil. (author)

  12. Equivalency testing of TTC Tergitol 7 agar (ISO 9308-1:2000) with five culture media for the detection of E. coli in water samples in Greece.

    Science.gov (United States)

    Mavridou, A; Smeti, E; Mandilara, G; Mandilara, G; Boufa, P; Vagiona-Arvanitidou, M; Vantarakis, A; Vassilandonopoulou, G; Pappa, O; Roussia, V; Tzouanopoulos, A; Livadara, M; Aisopou, I; Maraka, V; Nikolaou, E; Mandilara, G

    2010-01-01

    In this study ten laboratories in Greece compared the performance of reference method TTC Tergitol 7 Agar (with the additional test of beta-glucuronidase production) with five alternative methods, to detect E. coli in water, in line with European Water Directive recommendations. The samples were prepared by spiking drinking water with sewage effluent following a standard protocol. Chlorinated and non-chlorinated samples were used. The statistical analysis was based on the mean relative difference of confirmed counts and was performed in line with ISO 17994. The results showed that in total, three of the alternative methods (Chromocult Coliform agar, Membrane Lauryl Sulfate agar and Trypton Bilex-glucuronidase medium) were not different from TTC Tergitol 7 agar (TTC Tergitol 7 agar vs Chromocult Coliform agar, 294 samples, mean RD% 5.55; vs MLSA, 302 samples, mean RD% 1; vs TBX, 297 samples, mean RD% -2.78). The other two alternative methods (Membrane Faecal coliform medium and Colilert 18/ Quantitray) gave significantly higher counts than TTC Tergitol 7 agar (TTC Tergitol 7 agar vs MFc, 303 samples, mean RD% 8.81; vs Colilert-18/Quantitray, 76 samples, mean RD% 18.91). In other words, the alternative methods generated performance that was as reliable as, or even better than, the reference method. This study will help laboratories in Greece overcome culture and counting problems deriving from the EU reference method for E. coli counts in water samples.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  14. Chromium and zinc uptake by algae Gelidium and agar extraction algal waste: kinetics and equilibrium.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2007-11-19

    Biosorption of chromium and zinc ions by an industrial algal waste, from agar extraction industry has been studied in a batch system. This biosorbent was compared with the algae Gelidium itself, which is the raw material for agar extraction, and the industrial waste immobilized with polyacrylonitrile (composite material). Langmuir and Langmuir-Freundlich equilibrium models describe well the equilibrium data. The parameters of Langmuir equilibrium model at pH 5.3 and 20 degrees C were for the algae, q(L)=18 mg Cr(III)g(-1) and 13 mgZn(II)g(-1), K(L) = 0.021l mg(-1)Cr(III) and 0.026l mg(-1) Zn(II); for the algal waste, q(L)=12 mgCr(III)g(-1) and 7mgZn(II)g(-1), K(L)=0.033lmg(-1) Cr(III) and 0.042l mg(-1) Zn(II); for the composite material, q(L) = 9 mgCr(III)g(-1) and 6 mgZn(II)g(-1), K(L)=0.032l mg(-1)Cr(III) and 0.034l mg(-1)Zn(II). The biosorbents exhibited a higher preference for Cr(III) ions and algae Gelidium is the best one. The pseudo-first-order Lagergren and pseudo-second-order models fitted well the kinetic data for the two metal ions. Kinetic constants and equilibrium uptake concentrations given by the pseudo-second-order model for an initial Cr(III) and Zn(II) concentration of approximately 100 mgl(-1), at pH 5.3 and 20 degrees C were k(2,ads)=0.04 g mg(-1)Cr(III)min(-1) and 0.07 g mg(-1)Zn(II)min(-1), q(eq)=11.9 mgCr(III)g(-1) and 9.5 mgZn(II)g(-1) for algae; k(2,ads)=0.17 g mg(-1)Cr(III)min(-1) and 0.19 g mg(-1)Zn(II)min(-1), q(eq)=8.3 mgCr(III)g(-1) and 5.6 mgZn(II)g(-1) for algal waste; k(2,ads)=0.01 g mg(-1)Cr(III)min(-1) and 0.18 g mg(-1)Zn(II)min(-1), q(eq)=8.0 mgCr(III)g(-1) and 4.4 mgZn(II)g(-1) for composite material. Biosorption was modelled using a batch adsorber mass transfer kinetic model, which successfully predicts Cr(III) and Zn(II) concentration profiles. The calculated average homogeneous diffusivities, D(h), were 4.2 x 10(-8), 8.3 x 10(-8) and 1.4 x 10(-8)cm(2)s(-1) for Cr(III) and 4.8 x 10(-8), 9.7 x 10(-8) and 6.2 x 10(-8)cm(2)s(-1

  15. Direct impression on agar surface as a diagnostic sampling procedure for candida balanitis.

    Science.gov (United States)

    Lisboa, Carmen; Santos, António; Azevedo, Filomena; Pina-Vaz, Cidália; Rodrigues, Acácio Gonçalves

    2010-02-01

    The diagnosis of candida balanitis should be based upon both clinical and mycological data. The procedure of material collection is a critical issue to confirm or rule out the clinical diagnosis of candida balanitis. To compare direct impression of the glans on the agar surface of solid culture media with the collection of genital exudates with cotton swab for the diagnosis of candida balanitis. A prospective cross-sectional study was carried out during a 36-month period. Sexually transmitted disease clinic attendees with balanitis and asymptomatic men were included. Specimens for yeast culture were collected from the glans penis and inner preputial layer using the direct impression on CHROMagar candida medium and by swabbing with a sterile cotton swab. Among 478 men enrolled, 189 had balanitis. The prevalence of candida balanitis was 17.8% (85/478) confirmed after culture by direct impression; the swab method detected only 54/85 (63.5%) of these men. Of the 289 asymptomatic men, 36 (12.5%) yielded Candida spp; the swab method detected only 38.9% of these men. The risk of having candida balanitis is 8.9 (IC 95% 2.48 to 32.04) whenever the number of candida colonies recovered by direct impression was greater than 10. Direct impression on CHROMagar candida medium resulted in the highest Candida spp recovery rate. More than 10 colonies yielded by impression culture were statistically associated with candida balanitis. This method shows the ideal profile for sampling the male genital area for yeasts and should be included in the management of balanitis.

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

    Science.gov (United States)

    Skóra, Magdalena; Macura, Anna B

    2011-01-01

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

  17. Preparation and application of agar/alginate/collagen ternary blend functional food packaging films.

    Science.gov (United States)

    Wang, Long-Feng; Rhim, Jong-Whan

    2015-09-01

    Ternary blend agar/alginate/collagen (A/A/C) hydrogel films with silver nanoparticles (AgNPs) and grapefruit seed extract (GSE) were prepared. Their performance properties, transparency, tensile strength (TS), water vapor permeability (WVP), water contact angle (CA), water swelling ratio (SR), water solubility (WS), and antimicrobial activity were determined. The A/A/C film was highly transparent, and both AgNPs and GSE incorporated blend films (A/A/C(AgNPs) and A/A/C(GSE)) exhibited UV-screening effect, especially, the A/A/C(GSE) film had high UV-screening effect without sacrificing the transmittance. In addition, the A/A/C blend films formed efficient hydrogel film with the water holding capacity of 23.6 times of their weight. Both A/A/C(AgNPs) and A/A/C(GSE) composite films exhibited strong antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) food-borne pathogenic bacteria. The test results of fresh potatoes packaging revealed that all the A/A/C ternary blend films prevented forming of condensed water on the packaged film surface, both A/A/C(AgNPs) and A/A/C(GSE) composite films prevented greening of potatoes during storage. The results indicate that the ternary blend hydrogel films incorporated with AgNPs or GSE can be used not only as antifogging packaging films for highly respiring fresh agriculture produce, but also as an active food packaging system utilizing their strong antimicrobial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Sultana Razia

    2016-08-01

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

  19. Perbedaan Cara Penyebaran Suspensi terhadap Jumlah Bakteri pada Media Eosin Methylene Blue Agar

    Directory of Open Access Journals (Sweden)

    Ahmad Nuzuludin Kadri

    2015-06-01

    Full Text Available Dalam rangka pengawasan mutu secara biologis dilakukan pengujian laboratorium untuk mengisolasi dan melakukan jumlah penghitungan jumlah bakteri patogen (enumerasi. Tujuan dari penelitian ini adalah untuk mengetahui perbedaan cara penyebaran suspensi dengan menggunakan batang gelas bengkok, mikropipet dan ose terhadap jumlah bakteri yang terhitung pada media Eosin Methylene Blue Agar. Sampel diambil dari air susu kambing yang kemudian dihitung jumlah bakteri-nya dengan tiga kelompok perlakuan yaitu menggunakan batang gelas bengkok, mikropipet dan ose. Data hasil penelitian dianalisis menggunakan sidik ragam, bila hasilnya berbeda nyata maka dilanjutkan dengan uji Duncan. Jumlah bakteri yang terhitung dengan menggunakan batang gelas bengkok, mikropipet dan ose per ml berturut-turut mengandung 9.722.222 cfu, 68.944.444 cfu dan 116.444.444 cfu. Dengan sidik ragam, perlakuan cara penyebaran dengan menggunakan mikropipet dan ose berbeda sangat nyata (P<0,01 terhadap jumlah bakteri yang terhitung dengan menggunakan batang gelas bengkok. Setelah di uji dengan uji Duncan, rata-rata jumlah bakteri yang terhitung dengan menggunakan mikropipet dan ose lebih tinggi sangat nyata (P<0,01 dibandingkan dengan menggunakan batang gelas bengkok, sedangkan rata-rata jumlah bakteri yang terhitung menggunakan ose lebih tinggi sangat nyata (P<0,01 dibandingkan dengan menggunakan mikropipet. Kesimpulan dari penelitian ini adalah terdapat perbedaan cara penyebaran suspensi dengan menggunakan batang gelas bengkok,mikropipet dan ose terhadap jumlah bakteri pada media EMBA. Penyebaran bakteri menggunakan ose lebih banyak (P<0,01 dibandingkan mikropipet dan batang gelas bengkok. Sedangkan penyebaran bakteri menggunakan mikropipet lebih banyak (P<0,01 dibandingkan dengan gelas bengkok.

  20. Halococcus agarilyticus sp. nov., an agar-degrading haloarchaeon isolated from commercial salt.

    Science.gov (United States)

    Minegishi, Hiroaki; Echigo, Akinobu; Shimane, Yasuhiro; Kamekura, Masahiro; Itoh, Takashi; Ohkuma, Moriya; Usami, Ron

    2015-05-01

    Two agar-degrading halophilic archaeal strains, 62 E(T) and 197 A, were isolated from commercial salt samples. Cells were non-motile cocci, approximately 1.2-2.0 µm in diameter and stained Gram-negative. Colonies were pink-pigmented. Strain 62 E(T) was able to grow with 24-30% (w/v) NaCl (optimum, 27%), at pH 6.5-8.5 (optimum, pH 7.5) and at 22-47 °C (optimum, 42 °C). The 16S rRNA gene sequences of strains 62 E(T) and 197 A were identical, and the level of DNA-DNA relatedness between them was 90 and 90% (reciprocally). The closest relative was Halococcus saccharolyticus JCM 8878(T) with 99.7% similarity in 16S rRNA orthologous gene sequences, followed by Halococcus salifodinae JCM 9578(T) (99.6%), while similarities with other species of the genus Halococcus were equal to or lower than 95.1%. The rpoB' gene tree strongly supported that the two strains were members of the genus Halococcus . Mean DNA-DNA relatedness between strain 62 E(T) and H. saccharolyticus JCM 8878(T) and H. salifodinae JCM 9578(T) was 46 and 44%, respectively. The major polar lipids were archaeol derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, derived from both C20C20 and C20C25 archaeol, and sulfated diglycosyl archaeol-1. Several unidentified glycolipids were present. Based on the phenotypic and phylogenetic analyses, the isolates are considered to represent a novel species of the genus Halococcus , for which the name Halococcus agarilyticus sp. nov. is proposed. The type strain is 62 E(T) ( = JCM 19592(T) =KCTC 4143(T)). © 2015 IUMS.

  1. Agar Technique for the Cultivation In Vitro of Bone-Marrow Colonies

    Energy Technology Data Exchange (ETDEWEB)

    Metcalf, D. [Walter and Eliza Hall Institute, Royal Melbourne Hospital, Melbourne, VIC (Australia)

    1969-07-15

    In solid-state agar cultures certain haemopoietic cells proliferate and form discrete colonies of 200 - 4000 cells. Colony formation is dependent on stimulation by the colony-stimulating factor, and this is achieved by (1) the use of a cell feeder layer, (2) the addition of conditioned medium, or (3) the addition of human or mouse serum or urine containing the factor. All colonies initially contain granulocytic cells which differentiate from myeloblasts to polymorphs as colony growth proceeds. Later colonies develop a second population of phagocytic mononuclear cells (macrophages). The colony-forming-system is simple, readily quantitated and highly reproducible. Linear dose responses occur between the dose of colony-stimulating factor and the number and size of colonies developing from a standard number of bone-marrow cells. In-vitro colony formation has been achieved with haemopoietic cells of the following species: mouse, rat, hamster, guinea pig, rabbit and human. In the adult mouse, colony-forming cells are located in the bone marrow, spleen and blood and in the embryo, in the yolk sac, liver and spleen. The colony-forming cell appears to be an early member of the granulocytic series. The colony-forming system has been used as a quantitative assay system: (1) to assay levels of colony-stimulating factor in serum and urine and in the chemical- characterization and purification of the factor; and (2) to enumerate the number of colony-forming cells in haemopoietic tissues in response to a variety of experimental procedures and disease states. Since the system is applicable to human bone-marrow cells, it should prove of value in the quantitative assay of (1) survival of human bone marrow on storage, and (2) bone-marrow content of granulocytic precursor cells in various disease states and following various types of therapy. The system is not suitable for the mass production in vitro of haemopoietic cells for therapeutic use. (author)

  2. Effect of EDTA on Pb(II) Uptake and Translocation by Tumbleweed (Salsola Kali): Agar and Hydroponics Studies

    Energy Technology Data Exchange (ETDEWEB)

    de la Rosa, Guadalupe; Gardea-Torresdey, Jorge L.; Peralta-Videa, Jose R.; Aldrich, Mary

    2004-03-31

    Environmental accumulation of Pb represents a worldwide health hazard. While conventional cleanup techniques are generally expensive and soil disturbing, phytoremediation represents an inexpensive friendly option for the removal of contaminants from soil and water. In this research, tumbleweed (Salsola kali) plants exposed for 15 days to Pb(NO3)2 at 80 and 125 ppm in hydroponics and agar media, demonstrated a high capacity to uptake lead. The results showed that the plants cultivated in agar accumulated 25563, 5534 and 2185 mg Pb kg-1 DW in roots, stems and leaves, respectively. Moreover, Pb concentrations found in hydroponically grown tumbleweed plants tissues were 30744, 1511 and 1421 mg kg-1 DW in roots, stems and leaves, respectively. It was observed that EDTA enhanced Pb translocation. No Pb phytotoxic effects were observed during the experimental time period. Cellular structural features were also observed using TEM.

  3. Variation in Microbial Identification System Accuracy for Yeast Identification Depending on Commercial Source of Sabouraud Dextrose Agar

    OpenAIRE

    Kellogg, James A.; Bankert, David A.; Chaturvedi, Vishnu

    1999-01-01

    The accuracy of the Microbial Identification System (MIS; MIDI, Inc.) for identification of yeasts to the species level was compared by using 438 isolates grown on prepoured BBL Sabouraud dextrose agar (SDA) and prepoured Remel SDA. Correct identification was observed for 326 (74%) of the yeasts cultured on BBL SDA versus only 214 (49%) of yeasts grown on Remel SDA (P < 0.001). The commercial source of the SDA used in the MIS procedure significantly influences the system’s accuracy.

  4. Variation in Microbial Identification System accuracy for yeast identification depending on commercial source of Sabouraud dextrose agar.

    Science.gov (United States)

    Kellogg, J A; Bankert, D A; Chaturvedi, V

    1999-06-01

    The accuracy of the Microbial Identification System (MIS; MIDI, Inc. ) for identification of yeasts to the species level was compared by using 438 isolates grown on prepoured BBL Sabouraud dextrose agar (SDA) and prepoured Remel SDA. Correct identification was observed for 326 (74%) of the yeasts cultured on BBL SDA versus only 214 (49%) of yeasts grown on Remel SDA (P < 0.001). The commercial source of the SDA used in the MIS procedure significantly influences the system's accuracy.

  5. Performance of Chromogenic Candida agar and CHROMagar Candida in recovery and presumptive identification of monofungal and polyfungal vaginal isolates.

    Science.gov (United States)

    Ozcan, Kadri; Ilkit, Macit; Ates, Aylin; Turac-Bicer, Aygul; Demirhindi, Hakan

    2010-02-01

    Chromogenic Candida agar (OCCA) is a novel medium facilitating isolation and identification of Candida albicans, C. tropicalis, and C. krusei, as well as indicating polyfungal population in clinical samples. We compare the performance of OCCA, to CHROMagar Candida (CAC) and Sabouraud chloramphenicol agar (SCA). Vaginal swab samples from 392 women were simultaneously inoculated onto three study media. A total of 161 (41.1%) were found to be positive for fungi of which 140 (87%) were monofungal, and 21 (13%) polyfungal. One-hundred and fifty-seven samples (97.5%) were positive on CAC, 156 (96.9%) on OCCA, 148 (91.9%) on SCA and 144 (89.4%) samples were positive on all three media. The yeasts were identified by conventional methods including germ tube test, microscopic morphology on cornmeal-Tween 80 agar, and the commercial API 20C AUX. The 182 isolates were C. albicans (n = 104), C. glabrata (n = 51), C. krusei (n = 7), C. tropicalis (n = 5), C. famata (n = 3), C. kefyr (n = 3), C. zeylanoides (n = 3), C. colliculosa (n = 2), and other species of Candida (n = 4). Among the 21 polyfungal populations, 20 (95.2%) were detected in OCCA, 14 (66.7%) in CAC, and 13 (61.9%) in CAC and OCCA (P or=92.9% at 72 h. OCCA is more efficient and reliable for rapidly identifying C. albicans and polyfungal populations than CAC. However, CAC is more efficient for identifying C. krusei and C. tropicalis. A chromogenic agar with a higher isolation rate of yeasts and better detection of polyfungal populations than SCA, is suggested as a medium of first choice when available.

  6. Comparison of antibacterial activities of root-end filling materials by an agar diffusion assay and Alamar blue assay

    Directory of Open Access Journals (Sweden)

    Tsui-Hsien Huang

    2012-12-01

    Conclusion: We concluded that both the agar diffusion test and Alamar blue assay gave comparable findings of assessing the antimicrobial activity present in root-end filling materials. No antimicrobial activity was detected for mineral trioxide aggregate, calcium silicate cement, or amalgam after coming into contact with S. mutans, S. sanguinis and E. coli. IRM showed high antimicrobial activity against both S. sanguinis and E. coli.

  7. Mechanical touch responses of Arabidopsis TCH1-3 mutant roots on inclined hard-agar surface

    Science.gov (United States)

    Zha, Guodong; Wang, Bochu; Liu, Junyu; Yan, Jie; Zhu, Liqing; Yang, Xingyan

    2016-01-01

    The gravity-induced mechanical touch stimulus can affect plant root architecture. Mechanical touch responses of plant roots are an important aspect of plant root growth and development. Previous studies have reported that Arabidopsis TCH1-3 genes are involved in mechano-related events, how-ever, the physiological functions of TCH1-3 genes in Arabidopsis root mechanoresponses remain unclear. In the present study, we applied an inclined hard agar plate method to produce mechanical touch stimulus, and provided evidence that altered mechanical environment could influence root growth. Furthermore, tch1-3 Arabidopsis mutants were investigated on inclined agar surfaces to explore the functions of TCH1-3 genes on Arabidopsis root mechanoresponses. The results showed that two tch2 mutants, cml24-2 and cml24-4, exhibited significantly reduced root length, biased skewing, and decreased density of lateral root. In addition, primary root length and density of lateral root of tch3 (cml12-2) was significantly decreased on inclined agar surfaces. This study indicates that the tch2 and tch3 mutants are hypersensitive to mechanical touch stimulus, and TCH2 (CML24-2 and CML24-4) and TCH3 (CML12-2) genes may participate in the mechanical touch response of Arabidopsis roots.

  8. Irradiation of silver and agar/silver nanoparticles with argon, oxygen glow discharge plasma, and mercury lamp.

    Science.gov (United States)

    Ahmad, Mahmoud M; Abdel-Wahab, Essam A; El-Maaref, A A; Rawway, Mohammed; Shaaban, Essam R

    2014-01-01

    The irradiation effect of argon, oxygen glow discharge plasma, and mercury lamp on silver and agar/silver nanoparticle samples is studied. The irradiation time dependence of the synthesized silver and agar/silver nanoparticle absorption spectra and their antibacterial effect are studied and compared. In the agar/silver nanoparticle sample, as the irradiation time of argon glow discharge plasma or mercury lamp increases, the peak intensity and the full width at half maximum, FWHM, of the surface plasmon resonance absorption band is increased, however a decrease of the peak intensity with oxygen glow plasma has been observed. In the silver nanoparticle sample, as the irradiation time of argon, oxygen glow discharge plasma or mercury lamp increases, the peak intensity of the surface plasmon resonance absorption band is increased, however, there is no significant change in the FWHM of the surface plasmon resonance absorption band. The SEM results for both samples showed nanoparticle formation with mean size about 50 nm and 40 nm respectively. Throughout the irradiation time with the argon, oxygen glow discharge plasma or mercury lamp, the antibacterial activity of several kinds of Gram-positive and Gram-negative bacteria has been examined.

  9. Isolation of nontuberculous mycobacteria from soil using Middlebrook 7H10 agar with increased malachite green concentration.

    Science.gov (United States)

    Hu, Yuli; Yu, Xinglong; Zhao, Dun; Li, Runcheng; Liu, Yang; Ge, Meng; Hu, Huican

    2017-12-01

    Environmental exposure is considered to be responsible for nontuberculous mycobacterial infections in humans. To facilitate the isolation of mycobacteria from soil, Middlebrook 7H10 agar was optimized as an enhanced selective medium by increasing the concentration of malachite green. A series of modified Middlebrook 7H10 agar media with malachite green concentrations ranging from 2.5 to 2500 mg/L was evaluated using 20 soil samples decontaminated with 3% sodium dodecyl sulfate plus 2% NaOH for 30 min. Among these modified Middlebrook 7H10 media, the medium with malachite green at a concentration of 250 mg/L, i.e., at the same concentration as in Löwenstein-Jensen medium, was the most effective in terms of the number of plates with mycobacterial growth. This medium was further evaluated with 116 soil samples. The results showed that 87.1% (101/116) of the samples produced mycobacterial growth, and 15 samples (12.9%) produced no mycobacterial growth. Of the plates inoculated with the soil samples, each in duplicate, 5.2% (12/232) showed late contamination. In total, 19 mycobacterial species were isolated, including seven (36.8%) rapidly growing mycobacteria and 12 (63.2%) slowly growing mycobacteria. Our results demonstrate that the modified Middlebrook 7H10 agar with 250 mg/L malachite green is useful for the primary isolation of nontuberculous mycobacteria from soil.

  10. Broth and agar hop-gradient plates used to evaluate the beer-spoilage potential of Lactobacillus and Pediococcus isolates.

    Science.gov (United States)

    Haakensen, M; Schubert, A; Ziola, B

    2009-03-15

    Identification of the beer-spoilage Lactobacillus and Pediococcus bacteria has largely taken two approaches; identification of spoilage-associated genes or identification of specific species of bacteria regardless of ability to grow in beer. The problem with these two approaches is that they are either overly inclusive (i.e., detect all bacteria of a given species regardless of spoilage potential) or overly selective (i.e., rely upon individual, putative spoilage-associated genes). Our goal was to design a method to assess the ability of Lactobacillus and Pediococcus to spoil beer that is independent of speciation or genetic background. In searching for a method by which to differentiate between beer-spoilage bacteria and bacteria that cannot grow in beer, we explored the ability of lactobacilli and pediococci isolates to grow in the presence of varying concentrations of hop-compounds and ethanol in broth medium versus on agar medium. The best method for differentiating between bacteria that can grow in beer and bacteria that do not pose a threat as beer-spoilage organisms was found to be a hop-gradient agar plate containing ethanol. This hop-gradient agar plate technique provides a rapid and simple solution to the dilemma of assessing the ability of Lactobacillus and Pediococcus isolates to grow in beer, and provides new insights into the different strategies used by these bacteria to survive under the stringent conditions of beer.

  11. Research on Candida dubliniensis in a Brazilian yeast collection obtained from cardiac transplant, tuberculosis, and HIV-positive patients, and evaluation of phenotypic tests using agar screening methods.

    Science.gov (United States)

    Ribeiro, Patrícia Monteiro; Querido, Silvia Maria Rodrigues; Back-Brito, Graziela Nueremberg; Mota, Adolfo José; Koga-Ito, Cristiane Yumi; Jorge, Antonio Olavo Cardoso

    2011-09-01

    The aim of this study was to research Candida dubliniensis among isolates present in a Brazilian yeast collection and to evaluate the main phenotypic methods for discrimination between C. albicans and C. dubliniensis from oral cavity. A total of 200 isolates, presumptively identified as C. albicans or C. dubliniensis obtained from heart transplant patients under immunosuppressive therapy, tuberculosis patients under antibiotic therapy, HIV-positive patients under antiretroviral therapy, and healthy subjects, were analyzed using the following phenotypic tests: formation and structural arrangement of chlamydospores on corn meal agar, casein agar, tobacco agar, and sunflower seed agar; growth at 45 °C; and germ tube formation. All strains were analyzed by polymerase chain reaction (PCR). In a preliminary screen for C. dubliniensis, 48 of the 200 isolates on corn meal agar, 30 of the 200 on casein agar, 16 of the 200 on tobacco agar, and 15 of the 200 on sunflower seed agar produced chlamydoconidia; 27 of the 200 isolates showed no or poor growth at 45 °C. All isolates were positive for germ tube formation. These isolates were considered suggestive of C. dubliniensis. All of them were subjected to PCR analysis using C. dubliniensis-specific primers. C. dubliniensis isolates were not found. C. dubliniensis isolates were not recovered in this study done with immunocompromised patients. Sunflower seed agar was the medium with the smallest number of isolates of C. albicans suggestive of C. dubliniensis. None of the phenotypic methods was 100% effective for discrimination between C. albicans and C. dubliniensis. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Production of trichothecenes and other secondary metabolites by Fusarium culmorum and Fusarium equiseti on common laboratory media and a soil organic matter agar: An ecological interpretation

    DEFF Research Database (Denmark)

    Hestbjerg, H.; Nielsen, Kristian Fog; Thrane, Ulf

    2002-01-01

    trichothecene production was detected for 94 of 102 F culmorum isolates, only 8 of 57 F equiseti isolates were positive. Profiles of secondary metabolites were compared by following growth on yeast extract sucrose agar (YES), potato sucrose agar (PSA), and an agar medium, prepared from soil organic matter (SOM......), which was included to simulate growth, conditions in soil. SOM supported the production of chrysogine by F culmorum. The two species utilized the media differently. F culmorum produced zearalenone (ZEA) on YES, whereas some F. equiseti isolates produced ZEA on PSA. Other F. equiseti isolates produced...

  13. Optimization of the agar-gel method for isolation of migrating Ascaris suum larvae from the liver and lungs of pigs

    DEFF Research Database (Denmark)

    Saeed, I.; Roepstorff, A.; Rasmussen, T.

    2001-01-01

    Experiments on use of an agar-gel method for recovery of migrating Ascaris suum larvae from the liver and lungs of pigs were conducted to obtain fast standardized methods. Subsamples of blended tissues of pig liver and lungs were mixed with agar to a final concentration of 1% agar and the larvae...... clean suspension which reduced the sample counting time. Blending the liver for 60 sec in a commercial blender showed significantly higher larvae recovery than blending for 30 sec. Addition of gentamycin to reduce bacterial growth during incubation, glucose to increase larval motility during migration...

  14. Enumerating actinomycetes in compost bioaerosols at source—Use of soil compost agar to address plate 'masking'

    Science.gov (United States)

    Taha, M. P. M.; Drew, G. H.; Tamer Vestlund, A.; Aldred, D.; Longhurst, P. J.; Pollard, S. J. T.

    Actinomycetes are the dominant bacteria isolated from bioaerosols sampled at composting facilities. Here, a novel method for the isolation of actinomycetes is reported, overcoming masking of conventional agar plates, as well as reducing analysis time and costs. Repeatable and reliable actinomycetes growth was best achieved using a soil compost media at an incubation temperature of 44 °C and 7 days' incubation. The results are of particular value to waste management operators and their advisors undertaking regulatory risk assessments that support environmental approvals for compost facilities.

  15. High internal phase agar hydrogel dispersions in cocoa butter and chocolate as a route towards reducing fat content.

    Science.gov (United States)

    Skelhon, Thomas S; Olsson, Patrik K A; Morgan, Adam R; Bon, Stefan A F

    2013-09-01

    Reducing the fat content of chocolate formulations is a major challenge for the confectionery industry. We report the suspension of aqueous microgel agar particles of up to 80% v/v within sunflower oil, cocoa butter, and ultimately chocolate. The optimised emulsification process involves a shear-cooling step. We demonstrate the versatility of our method when applied to white, milk, and dark chocolate formulations, whilst preserving the desired polymorph V of the cocoa butter matrix. In addition, we show that this technology can be used as a strategy to disperse alcoholic beverages into chocolate confectionery.

  16. A Direct Quantitative Agar-Plate Based Assay for Analysis of Pseudomonas protegens PF-5 Degradation of Polyurethane Films (Postprint)

    Science.gov (United States)

    2014-10-02

    was dissolved in methanol ; Irogran (1 g) was dissolved in 25 mL THF; and AS-P108 was prepared by adding 0.3 g of catalyst to 10 g of resin and then... Selected results are in Supple- mental Information. 3. Results 3.1. General growth characteristics of Pf-5 on M9/citrate agar plates Dilutions of P...minimal. An IR map with the color scale corresponding to the in- tensity of the 1735 cm1 carbonyl absorbance from the urethane and ester components is

  17. Fluconazole-containing agar Sabouraud dextrose plates are not useful when screening for susceptibility in Candida albicans.

    Science.gov (United States)

    Bordallo-Cardona, M A; Marcos-Zambrano, L J; Gómez G de la Pedrosa, E; Escribano, P; Bouza, E; Guinea, J; Cantón, R

    2017-04-01

    Fluconazole is an alternative for candidemic patients who are not critically ill. Fluconazole is mainly fungistatic and does not completely inhibit visual Candida albicans growth. We studied the usefulness of fluconazole-containing Sabouraud dextrose agar plates for detecting susceptibility to fluconazole in C. albicans. Adjusted inocula of 19 isolates were transferred directly onto fluconazole-containing Sabouraud dextrose plates (concentrations ranging from 0.125 mg/L to 128 mg/L). The fluconazole MIC in fresh isolates and after growth on the fluconazole-containing plate at 128 mg/L was recorded following the EUCAST EDef 7.2 guidelines. Then isolates were classified according to their degree of trailing production, based on microdilution procedure. All isolates were able to grow on all fluconazole-containing plates, even those isolates susceptible to fluconazole. In fact, we selected isolates with different degrees of trailing based on microdilution procedures. 50% of isolates classified as heavy trailers, 35.71% as moderate trailers, and 14.28% as slight trailers. The use of fluconazole-containing Sabouraud dextrose agar plates was not a reliable method to detect fluconazole susceptibility in C. albicans isolates; growth of the isolates was a trailing effect rather than true resistance.

  18. In vitro fermentation and prebiotic potential of novel low molecular weight polysaccharides derived from agar and alginate seaweeds.

    Science.gov (United States)

    Ramnani, Priya; Chitarrari, Roberto; Tuohy, Kieran; Grant, John; Hotchkiss, Sarah; Philp, Kevin; Campbell, Ross; Gill, Chris; Rowland, Ian

    2012-02-01

    Fermentation properties and prebiotic potential of novel low molecular weight polysaccharides (LMWPs) derived from agar and alginate bearing seaweeds was investigated. Ten LMWPs were supplemented to pH, temperature controlled anaerobic batch cultures inoculated with human feces from three donors, in triplicate. Microbiota changes were monitored using Fluorescent in-situ hybridization and short chain fatty acids, the fermentation end products were analysed using gas chromatography. Of the ten LMWPs tested, Gelidium seaweed CC2253 of molecular weight 64.64 KDa showed a significant increase in bifidobacterial populations from log(10) 8.06 at 0 h to log(10) 8.55 at 24 h (p = 0.018). For total bacterial populations, alginate powder CC2238 produced a significant increase from log(10) 9.01 at 0 h to log(10) 9.58 at 24 h (p = 0.032). No changes were observed in the other bacterial groups tested viz. Bacteroides, Lactobacilli/Enterococci, Eubacterium rectale/Clostridium coccoides and Clostridium histolyticum. The polysaccharides also showed significant increases in total SCFA production, particularly acetic and propionic acids, indicating that they were readily fermented. In conclusion, some LMWPs derived from agar and alginate bearing seaweeds were fermented by gut bacteria and exhibited potential to be used a novel source of prebiotics. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Determination of in vitro synergy for dual antimicrobial therapy against resistant Neisseria gonorrhoeae using Etest and agar dilution.

    Science.gov (United States)

    Wind, Carolien M; de Vries, Henry J C; van Dam, Alje P

    2015-03-01

    In response to antimicrobial resistance of Neisseria gonorrhoeae to last-resort extended-spectrum cephalosporins, combination therapy of azithromycin+ceftriaxone is now recommended. Dual therapy can be effective to treat monoresistant strains as well as multidrug-resistant strains, preferably employing the effect of in vitro synergy. As reports on in vitro synergy of azithromycin+ceftriaxone in N. gonorrhoeae are conflicting, in this study an evaluation of this combination was performed using a cross-wise Etest method and agar dilution. Synergy was defined as a fractional inhibitory concentration index (FICI) of ≤0.5. To identify other dual treatment options for gonorrhoea, in vitro synergy was evaluated for 65 dual antimicrobial combinations using Etest. Azithromycin, cefixime, ceftriaxone, colistin, ertapenem, fosfomycin, gentamicin, minocycline, moxifloxacin, rifampicin, spectinomycin and tigecycline were screened for synergy in all possible combinations. No synergy or antagonism was found for any of the 65 combinations. The geometric mean FICI ranged from 0.82 to 2.00. The mean FICI of azithromycin+ceftriaxone was 1.18 (Etest) and 0.55 (agar dilution). The difference between both methods did not result in a difference in interpretation of synergy. Ceftriaxone-resistant strain F89 was tested in all combinations and no synergy was found for any of them. Most importantly, the ceftriaxone minimum inhibitory concentration of F89 was not decreased below the breakpoint with any concentration of azithromycin. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  20. Inactivation of pathogenic bacteria inoculated onto a Bacto™ agar model surface using TiO2-UVC photocatalysis, UVC and chlorine treatments.

    Science.gov (United States)

    Yoo, S; Ghafoor, K; Kim, S; Sun, Y W; Kim, J U; Yang, K; Lee, D-U; Shahbaz, H M; Park, J

    2015-09-01

    The aim of this study was to study inactivation of different pathogenic bacteria on agar model surface using TiO2-UV photocatalysis (TUVP). A unified food surface model was simulated using Bacto(™) agar, a routinely used microbial medium. The foodborne pathogenic bacteria Escherichia coli K12 (as a surrogate for E. coli O157:H7), Salmonella Typhimurium, Staphylococcus aureus and Listeria monocytogenes were inoculated onto the agar surface, followed by investigation of TUVP-assisted inactivation and morphological changes in bacterial cells. The TUVP process showed higher bacterial inactivation, particularly for Gram-negative bacteria, than UVC alone and a control (dark reaction). A TUVP treatment of 17·2 mW cm(-2) (30% lower than the UVC light intensity) reduced the microbial load on the agar surface by 4·5-6·0 log CFU cm(-2). UVC treatment of 23·7 mW cm(-2) caused 3·0-5·3 log CFU cm(-2) reduction. The use of agar model surface is effective for investigation of bacterial disinfection and TUVP is a promising nonthermal technique. The results showing effects of photocatalysis and other treatments for inactivation of bacterial pathogens on model surface can be useful for applying such processes for disinfection of fruit, vegetables and other similar surfaces. © 2015 The Society for Applied Microbiology.

  1. Biomimetic synthesis of hollow calcium carbonate with the existence of the agar matrix and bovine serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jianhua, E-mail: fjh2008@126.com; Wu, Gang; Qing, Chengsong

    2016-01-01

    Proteins play important roles in the process of biomineralization. Vaterite and calcite have been synthesized by the reaction of Na{sub 2}CO{sub 3} and CaCl{sub 2} in the bovine serum albumin (BSA) and agar system. The samples have been characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The shape of CaCO{sub 3} crystal has been analyzed by scanning electronic microscopy (SEM). The results show that calcite is a single product in the absence of BSA, but the product is a mixture of calcite and vaterite in the presence of BSA. The spheral shell of CaCO{sub 3} crystal was obtained when the concentration of BSA increased to 9.0 mg/mL. - Highlights: • Biomimetic synthesis of hollow calcium carbonate • Calcification mechanisms in the presence of both protein and polysaccharides • Biomineralization under the action of protein and polysaccharides.

  2. In vitro susceptibility of filamentous fungi to copper nanoparticles assessed by rapid XTT colorimetry and agar dilution method.

    Science.gov (United States)

    Ghasemian, E; Naghoni, A; Tabaraie, B; Tabaraie, T

    2012-12-01

    Metal nanoparticles and their uses in various aspects have recently drawn a great deal of attention. One of the major applications is that it can be used as an antimicrobial agent. They can be considered in approaches targeted to decrease the harms caused by microorganisms, specifically fungi, threatening the medical and industrial areas. The aim of this study was to investigate the antifungal activity of synthesized copper nanoparticles (CuNPs) against four filamentous fungi including Alternaria alternata, Aspergillus flavus, Fusarium solani, and Penicillium chrysogenum. Zerovalent copper nanoparticles of mean size 8nm were synthesized by inert gas condensation (IGC) method. The antifungal activity of these synthesized copper nanoparticles was measured against selected fungi by using two different techniques including agar dilution method and XTT reduction assay. The minimal inhibitory concentrations (MICs) for copper nanoparticles by agar dilution method were less or equal to 40mg/L for P. chrysogenum, less or equal to 60mg/L for A. alternata, less or equal to 60mg/L for F. solani, and less or equal to 80mg/L for A. flavus. And also MICs obtained by XTT reduction assay ranged from 40 to 80mg/L. Our data demonstrated that the copper nanoparticles inhibited fungal growth, but the fungal sensitivity to copper nanoparticles varies depending on the fungal species. Therefore, it is advisable that the minimal inhibitory concentrations (MICs) be examined before using these compounds. It is hoped that, in future, copper nanoparticles could replace some antifungal agents, making them applicable to many different medical devices and antimicrobial control system. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  3. Equilibrium and kinetic modelling of Cd(II) biosorption by algae Gelidium and agar extraction algal waste.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2006-01-01

    In this study an industrial algal waste from agar extraction has been used as an inexpensive and effective biosorbent for cadmium (II) removal from aqueous solutions. This biosorbent was compared with the algae Gelidium itself, which is the raw material for agar extraction. Equilibrium data follow both Langmuir and Redlich-Peterson models. The parameters of Langmuir equilibrium model are q(max)=18.0 mgg(-1), b=0.19 mgl(-1) and q(max)=9.7 mgg(-1), b=0.16 mgl(-1), respectively for Gelidium and the algal waste. Kinetic experiments were conducted at initial Cd(II) concentrations in the range 6-91 mgl(-1). Data were fitted to pseudo-first- and second-order Lagergren models. For an initial Cd(II) concentration of 91 mgl(-1) the parameters of the pseudo-first-order Lagergren model are k(1,ads)=0.17 and 0.87 min(-1); q(eq)=16.3 and 8.7 mgg(-1), respectively, for Gelidium and algal waste. Kinetic constants vary with the initial metal concentration. The adsorptive behaviour of biosorbent particles was modelled using a batch reactor mass transfer kinetic model. The model successfully predicts Cd(II) concentration profiles and provides significant insights on the biosorbents performance. The homogeneous diffusivity, D(h), is in the range 0.5-2.2 x10(-8) and 2.1-10.4 x10(-8)cm(2)s(-1), respectively, for Gelidium and algal waste.

  4. Evaluation of the thin agar layer method for the recovery of pressure-injured and heat-injured Listeria monocytogenes.

    Science.gov (United States)

    Lavieri, Nicolas A; Sebranek, Joseph G; Cordray, Joseph C; Dickson, James S; Jung, Stephanie; Manu, David K; Mendonça, Aubrey F; Brehm-Stecher, Byron F; Stock, Joseph; Stalder, Kenneth J

    2014-05-01

    A sublethally injured bacterial cell has been defined as a cell that survives a stress such as heating, freezing, acid treatment, or other antimicrobial intervention but can repair the cellular damage exerted by the stressor and later regain its original ability to grow. Consequently, sublethally injured cells are not likely to be included in conventional enumeration procedures, which could result in unrealistically low counts unless efforts are made to encourage recovery of the injured cells before enumeration. The objective of this study was to evaluate the use of the thin agar layer (TAL) method for the recovery of pressure-injured and heat-injured Listeria monocytogenes in a tryptic soy broth with 0.6% yeast extract system. Pressure injury consisted of treatment of a culture of mixed L. monocytogenes strains with high hydrostatic pressure at 400 or 600 MPa for 1 s, 2 min, 4 min, or 6 min at a process temperature of 12±2 °C. Heat injury consisted of treatment of a culture of mixed L. monocytogenes strains at 60±1 °C for 3, 6, or 9 min. Growth media were tryptic soy agar (TSA) with 0.6% yeast extract, modified Oxford medium (MOX), and TAL, which consisted of a 7-ml layer of TSA overlaid onto solidified MOX. Counts of viable L. monocytogenes on TAL were higher than those on MOX in the heat-injury experiment but not in the pressure-injury experiment. Therefore, the effectiveness of the TAL method may be specific to the type of injury applied to the microorganism and should be investigated in a variety of cellular injury scenarios.

  5. Black-box modeling to estimate tissue temperature during radiofrequency catheter cardiac ablation: feasibility study on an agar phantom model

    International Nuclear Information System (INIS)

    Blasco-Gimenez, Ramón; Lequerica, Juan L; Herrero, Maria; Hornero, Fernando; Berjano, Enrique J

    2010-01-01

    The aim of this work was to study linear deterministic models to predict tissue temperature during radiofrequency cardiac ablation (RFCA) by measuring magnitudes such as electrode temperature, power and impedance between active and dispersive electrodes. The concept involves autoregressive models with exogenous input (ARX), which is a particular case of the autoregressive moving average model with exogenous input (ARMAX). The values of the mode parameters were determined from a least-squares fit of experimental data. The data were obtained from radiofrequency ablations conducted on agar models with different contact pressure conditions between electrode and agar (0 and 20 g) and different flow rates around the electrode (1, 1.5 and 2 L min −1 ). Half of all the ablations were chosen randomly to be used for identification (i.e. determination of model parameters) and the other half were used for model validation. The results suggest that (1) a linear model can be developed to predict tissue temperature at a depth of 4.5 mm during RF cardiac ablation by using the variables applied power, impedance and electrode temperature; (2) the best model provides a reasonably accurate estimate of tissue temperature with a 60% probability of achieving average errors better than 5 °C; (3) substantial errors (larger than 15 °C) were found only in 6.6% of cases and were associated with abnormal experiments (e.g. those involving the displacement of the ablation electrode) and (4) the impact of measuring impedance on the overall estimate is negligible (around 1 °C)

  6. Effects of extracellular matrix proteins on macrophage differentiation, growth, and function: comparison of liquid and agar culture systems

    Science.gov (United States)

    Armstrong, J. W.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Both spaceflight and skeletal unloading suppress the haematopoietic differentiation of macrophages (Sonnenfeld et al., Aviat. Space Environ. Med., 61:648-653, 1990; Armstrong et al., J. Appl. Physiol., 75:2734-2739, 1993). The mechanism behind this reduction in haematopoiesis has yet to be elucidated. However, changes in bone marrow extracellular matrix (ECM) may be involved. To further understand the role of ECM products in macrophage differentiation, we have performed experiments evaluating the effects of fibronectin, laminin, collagen type I, and collagen type IV on macrophage development and function. Bone marrow-derived macrophages cultured on four different ECM substrates in liquid culture medium showed less growth than those cultured on plastic. Significant morphological differences were seen on each of the substrates used. Phenotypically and functionally, as measured by class II major histocompatibility molecule (MHCII) expression, MAC-2 expression, and the secretion of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), these macrophages were similar. In contrast, bone marrow-derived macrophages cultured in suspension, using agar, showed no difference in growth when exposed to ECM proteins. However, IL-6 and TNF-alpha secretion was affected by fibronectin, laminin, collagen type I, and collagen type IV in a concentration-dependent manner. We conclude that the ECM products fibronectin, laminin, collagen type I, and collagen type IV have profound effects on macrophage development and function. Additionally, we suggest that an ECM-supplemented agar culture system provides an environment more analogous to in vivo bone marrow than does a traditional liquid culture system.

  7. A screening method for β-glucan hydrolase employing Trypan Blue-coupled β-glucan agar plate and β-glucan zymography.

    Science.gov (United States)

    Park, Chang-Su; Yang, Hee-Jong; Kim, Dong-Ho; Kang, Dae-Ook; Kim, Min-Soo; Choi, Nack-Shick

    2012-06-01

    A new screening method for β-(1,3-1,6) glucan hydrolase was developed using a pure β-glucan from Aureobaisidum pullulans by zymography and an LB-agar plate. Paenibacillus sp. was screened as a producer a β-glucan hydrolase on the Trypan Blue-coupled β-glucan LB-agar plate and the activity of the enzyme was analyzed by SDS-β-glucan zymography. The β-glucan was not hydrolyzed by Bacillus spp. strains, which exhibit cellulolytic activity on CMC zymography. The gene, obtaining by shotgun cloning and encoding the β-glucan hydrolase of Paenibacillus sp. was sequenced.

  8. Detection of group B streptococci in Lim broth by use of group B streptococcus peptide nucleic acid fluorescent in situ hybridization and selective and nonselective agars.

    Science.gov (United States)

    Montague, Naomi S; Cleary, Timothy J; Martinez, Octavio V; Procop, Gary W

    2008-10-01

    The sensitivity, specificity, and positive and negative predictive values for the detection of group B streptococci from Lim enrichment broth with sheep blood agar (SBA), with selective Streptococcus agar (SSA), and by a peptide nucleic acid fluorescent in situ hybridization (PNA FISH) assay were as follows: for culture on SBA, 68.4%, 100%, 100%, and 87.9%, respectively; for culture on SSA, 85.5%, 100%, 100%, and 94.1%, respectively; and for the PNA FISH assay, 97.4%, 98.3%, 96.1%, and 98.9%, respectively.

  9. Corrigendum to “Rheological properties of agar and carrageenan from Ghanaian red seaweeds” [Food Hydrocolloids 63 (2017) 50–58

    DEFF Research Database (Denmark)

    Rhein-Knudsen, Nanna; Ale, Marcel Tutor; Ajalloueian, Fatemeh

    2018-01-01

    . G., Penninkhof, B., Rudolph, B., & De Ruiter, G. A. (1999). A novel high-performance anion-exchange chromatographic method for the analysis of carrageenans and agars containing 3,6-anhydrogalactose. Analytical Biochemistry, 268, 213-222. Table 3 Overview of seaweed type (hydrocolloid source......), hydrocolloid extraction method (direct water-extraction or after alkali treatment), hydrocolloid and monomer1 yields, and sulfate levels [data given as means ± SD]. Different roman superscript letters indicate significant differences (P agar yields, monosaccharides...

  10. A novel DTI-QA tool: Automated metric extraction exploiting the sphericity of an agar filled phantom.

    Science.gov (United States)

    Chavez, Sofia; Viviano, Joseph; Zamyadi, Mojdeh; Kingsley, Peter B; Kochunov, Peter; Strother, Stephen; Voineskos, Aristotle

    2018-02-01

    To develop a quality assurance (QA) tool (acquisition guidelines and automated processing) for diffusion tensor imaging (DTI) data using a common agar-based phantom used for fMRI QA. The goal is to produce a comprehensive set of automated, sensitive and robust QA metrics. A readily available agar phantom was scanned with and without parallel imaging reconstruction. Other scanning parameters were matched to the human scans. A central slab made up of either a thick slice or an average of a few slices, was extracted and all processing was performed on that image. The proposed QA relies on the creation of two ROIs for processing: (i) a preset central circular region of interest (ccROI) and (ii) a signal mask for all images in the dataset. The ccROI enables computation of average signal for SNR calculations as well as average FA values. The production of the signal masks enables automated measurements of eddy current and B0 inhomogeneity induced distortions by exploiting the sphericity of the phantom. Also, the signal masks allow automated background localization to assess levels of Nyquist ghosting. The proposed DTI-QA was shown to produce eleven metrics which are robust yet sensitive to image quality changes within site and differences across sites. It can be performed in a reasonable amount of scan time (~15min) and the code for automated processing has been made publicly available. A novel DTI-QA tool has been proposed. It has been applied successfully on data from several scanners/platforms. The novelty lies in the exploitation of the sphericity of the phantom for distortion measurements. Other novel contributions are: the computation of an SNR value per gradient direction for the diffusion weighted images (DWIs) and an SNR value per non-DWI, an automated background detection for the Nyquist ghosting measurement and an error metric reflecting the contribution of EPI instability to the eddy current induced shape changes observed for DWIs. Copyright © 2017 Elsevier

  11. Identification of non-streptococcal organisms from human dental plaque grown on the Streptococcus-selective medium mitis-salivarius agar.

    Science.gov (United States)

    Kim, Yeon-Hee; Lee, Si Young

    2015-02-01

    Mitis-salivarius (MS) agar has been used widely in microbial epidemiological studies because oral viridans streptococci can be selectively grown on this medium. Even though the previous findings reported the limited selecting power of MS agar for streptococcus strains, the identities of non-streptococcal strains from human oral samples which can grow on this medium are not clear yet. In this study, we identified non-streptococcal organisms grown on MS agar plates by polymerase chain reaction (PCR) amplification and sequencing of the 16S ribosomal RNA (rRNA) gene. Eighty bacterial colonies on MS plates were isolated from plaque samples, and bacterial identification was achieved with the rapid ID 32 Strep system and mini API reader. The bacterial colonies identified as non-streptococci by the API system were selected for further identification. The 16S rRNA gene was amplified by PCR and verified using DNA sequencing analysis for identification. Sequences were compared with those of reference organisms in the genome database of the National Center for Biotechnology Information using the Basic Local Alignment Search Tool (BLAST). Among the 11 isolated non-streptococcal strains on MS plates, 3 strains were identified as Actinomyces naeslundii, 7 strains were identified as Actinomyces oris and 1 strain were identified as Actinomyces sp. using Blastn. In this study, we showed that some oral Actinomyces species can grow on Streptococcus-selective MS agar plates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. A comparison of a new centrifuge sugar flotation technique with the agar method for the extraction of immature Culicoides (Diptera: Ceratopogonidae) life stages from salt marsh soils.

    Science.gov (United States)

    Two sampling techniques, agar extraction (AE) and centrifuge sugar flotation extraction (CSFE) were compared to determine their relative efficacy to recover immature stages of Culicoides spp from salt marsh substrates. Three types of samples (seeded with known numbers of larvae, homogenized field s...

  13. Comparison of real-time PCR with disk diffusion, agar screen and E-test methods for detection of methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Shariati, Laleh; Validi, Majid; Tabatabaiefar, Mohammad Amin; Karimi, Ali; Nafisi, Mohammad Reza

    2010-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen. Our main objective was to compare oxacillin disk test, oxacillin E-test, and oxacillin agar screen for detection of methicillin resistance in S. aureus, using real-time PCR for mecA as the "gold standard" comparison assay. 196 S. aureus isolates were identified out of 284 Staphylococcus isolates. These isolates were screened for MRSA with several methods: disk diffusion, agar screen (6.0 μg/ml), oxacillin E-test, and real-time PCR for detection of mecA gene. Of the 196 S. aureus isolates tested, 96 isolates (49%) were mecA-positive and 100 isolates (51%) mecA-negative. All methods tested had a statistically significant agreement with real-time PCR. E-test was 100% sensitive and specific for mecA presence. The sensitivity and specificity of oxacillin agar screen method were 98 and 99%, respectively and sensitivity and specificity of oxacillin disk diffusion method were 95 and 93%, respectively. In the present study, oxacillin E-test is proposed as the best phenotypic method. For economic reasons, the oxacillin agar screen method (6.0 μg/ml), which is suitable for the detection of MRSA, is recommended due to its accuracy and low cost.

  14. Development of edible films from tapioca starch and agar, enriched with red cabbage (Brassica oleracea) as a sausage deterioration bio-indicator

    Science.gov (United States)

    Aditya Wardana, Ata; Dewanti Widyaningsih, Tri

    2017-12-01

    Sausage spoilage has been identified as a cause of some food poisoning cases. Development of a bioindicator film is one of the alternative methods to detect sausage deterioration. The objectives of this paper were to develop a bioindicator edible films (BEF) from tapioca starch (TS), agar, and red cabbage juice (RC), and to evaluate its performance on sausage deterioration detection. The experiment had a 3x3 randomized factorial experimental design (agar: 3, 5, 7% by weight of TS; RC: 10, 15, 20% v/v based on 100% of suspension). Glycerol was used as the plasticizer. The results showed that the addition of agar into the film solution increased the thickness, elongation, and tensile strength, and decreased water vapour transmission rate (WVTR). While the addition of RC increased the thickness, but decreased elongation, tensile strength, and WVTR. BEF consisting of 2% tapioca starch, 7% (w/w) agar and 10 % (v/v) RC was chosen to apply on sausage. It could detect an increase in the microbial population and in the pH variations as result of sausage deterioration at 24, 48, and 72 h shown through color changes of BEF from bright purple at 0 h to light purple, dark purple-blue, and purple-green color respectively.

  15. Development of a D-amino acids electrochemical sensor based on immobilization of thermostable D-Proline dehydrogenase within agar gel membrane

    International Nuclear Information System (INIS)

    Tani, Yuji; Tanaka, Katsuhito; Yabutani, Tomoki; Mishima, Yuji; Sakuraba, Haruhiko; Ohshima, Toshihisa; Motonaka, Junko

    2008-01-01

    A novel biosensor for determination of D-amino acids (DAAs) in biological samples by using an electrode based on immobilization of a thermostable D-Proline dehydrogenase (D-Pro DH) within an agar gel membrane was developed. The electrode was simply prepared by spin-coating the agar solution with the D-Pro DH on a glassy carbon (GC) electrode. An electrocatalytic oxidation current of 2,6-dichloroindophenol (DCIP) was observed at -100 mV vs. Ag/AgCl with the addition of 5 and 20 mmol L -1 D-proline. The current response and its relative standard deviation were 0.15 μA and 7.6% (n = 3), respectively, when it was measured in a pH 8.0 phosphate buffer solution containing 10 mmol L -1 D-proline and 0.5 mmol L -1 DCIP at 50 deg. C. The current response of D-proline increased with increase of the temperature of the sample solution up to 70 deg. C. The electrocatalytic response at the D-Pro DH/agar immobilized electrode subsequently maintained for 80 days. Finally, the D-Pro DH/agar immobilized electrode was applied to determination of DAAs in a human urine sample. The determined value of DAAs in the human urine and its R.S.D. were 1.39 ± 0.12 mmol L -1 and 8.9% (n = 3), respectively

  16. Two-dimensional network formation of cardiac myocytes in agar microculture chip with 1480 nm infrared laser photo-thermal etching.

    Science.gov (United States)

    Kojima, Kensuke; Moriguchi, Hiroyuki; Hattori, Akihiro; Kaneko, Tomoyuki; Yasuda, Kenji

    2003-11-01

    We have developed a new method that enables agar microstructures to be used to cultivate cells and that allows cell network patterns to be controlled. The method makes use of non-contact three-dimensional photo-thermal etching with a 1480 nm infrared focused laser beam, which is strongly absorbed by water and agar gel, to form the shapes of agar microstructures. It allows microstructures to be easily formed in an agar layer within a few minutes, with cell-culture holes formed by the spot heating of a 100 mW laser and tunnels by the tracing of a 100 microm s(-1), 40 mW laser. We cultivated rat cardiac myocytes in adjacent microstructures and observed synchronized beating in them 90 min after they had made physical contact. Our results indicate that the system can make and use microstructures for cell-network cultivation in a minimal amount of time without any expensive microfabrication facilities or complicated procedures.

  17. Experimenting with a Visible Copper-Aluminum Displacement Reaction in Agar Gel and Observing Copper Crystal Growth Patterns to Engage Student Interest and Inquiry

    Science.gov (United States)

    Xu, Xinhua; Wu, Meifen; Wang, Xiaogang; Yang, Yangyiwei; Shi, Xiang; Wang, Guoping

    2016-01-01

    The reaction process of copper-aluminum displacement in agar gel was observed at the microscopic level with a stereomicroscope; pine-like branches of copper crystals growing from aluminum surface into gel at a constant rate were observed. Students were asked to make hypotheses on the pattern formation and design new research approaches to prove…

  18. Characterization of a novel alkaline arylsulfatase from Marinomonas sp. FW-1 and its application in the desulfation of red seaweed agar.

    Science.gov (United States)

    Wang, Xueyan; Duan, Delin; Xu, Jiachao; Gao, Xin; Fu, Xiaoting

    2015-10-01

    A bacterial strain capable of hydrolyzing sulfate ester bonds of p-nitrophenyl sulfate (pNPS) and agar was isolated from the coast area of Qingdao, China. It was identified as Marinomonas based on its 16S rRNA gene sequence and named as Marinomonas sp. FW-1. An arylsulfatase with a recovery of 13 % and a fold of 12 was purified to a homogeneity using ion exchange and gel filtration chromatographies. The enzyme was composed of a single polypeptide chain with the molecular mass of 33 kDa estimated using SDS-PAGE. The optimal pH and temperature of arylsulfatase were pH 9.0 and 45, respectively. Arylsulfatase was stable over pH 8-11 and at temperature below 55 °C. The K m and V max of this enzyme for the hydrolysis of pNPS were determined to be 13.73 and 270.27 μM/min, respectively. The desulfation ratio against agar from red seaweed Gelidium amansii and Gracilaria lemaneiformis were 86.11 and 89.61 %, respectively. There was no difference between the DNA electrophoresis spectrum on the gel of the arylsulfatase-treated G. amansii agar and that of the commercial agarose. Therefore, this novel alkaline arylsulfatase might have a great potential for application in enzymatic conversion of agar to agarose.

  19. A modified MacConkey agar for selective enumeration of necrotoxigenic E. coli O55 and probiotic E. coli Nissle 1917

    Czech Academy of Sciences Publication Activity Database

    Šplíchalová, Alla; Šplíchal, Igor; Sonnenborn, U.; Rada, V.

    2014-01-01

    Roč. 103, SEP 2014 (2014), s. 82-86 ISSN 0167-7012 R&D Projects: GA ČR GA524/09/0365 Institutional support: RVO:61388971 Keywords : MacConkey agar * E. coil O55 * NTEC Subject RIV: CE - Biochemistry Impact factor: 2.026, year: 2014

  20. Screening of tannin acyl hydrolase (E.C.3.1.1.20) producing tannery effluent fungal isolates using simple agar plate and SmF process.

    Science.gov (United States)

    Murugan, K; Saravanababu, S; Arunachalam, M

    2007-03-01

    Industrially important tannase producing fungi were isolated from tannery effluent using simple agar plate method. The isolates were screened by submerged fermentation using auto-controlled bioreactor. The colony diameter on the solid surface media shows high correlation with quantitative production of tannase. The isolate Aspergillus niger shows maximum production of both extracellular and intracellular enzyme.

  1. Mutations in Arabidopsis thaliana genes involved in the tryptophan biosynthesis pathway affect root waving on tilted agar surfaces

    Science.gov (United States)

    Rutherford, R.; Gallois, P.; Masson, P. H.

    1998-01-01

    Arabidopsis thaliana roots grow in a wavy pattern upon a slanted surface. A novel mutation in the anthranilate synthase alpha 1 (ASA1) gene, named trp5-2wvc1, and mutations in the tryptophan synthase alpha and beta 1 genes (trp3-1 and trp2-1, respectively) confer a compressed root wave phenotype on tilted agar surfaces. When trp5-2wvc1 seedlings are grown on media supplemented with anthranilate metabolites, their roots wave like wild type. Genetic and pharmacological experiments argue that the compressed root wave phenotypes of trp5-2wvc1, trp2-1 and trp3-1 seedlings are not due to reduced IAA biosynthetic potential, but rather to a deficiency in L-tryptophan (L-Trp), or in a L-Trp derivative. Although the roots of 7-day-old seedlings possess higher concentrations of free L-Trp than the shoot as a whole, trp5-2wvc1 mutants show no detectable alteration in L-Trp levels in either tissue type, suggesting that a very localized shortage of L-Trp, or of a L-Trp-derived compound, is responsible for the observed phenotype.

  2. Comparison of agar gel immunodiffusion test, enzyme-linked immunosorbent assay and PCR in diagnostics of enzootic bovine leukosis

    Directory of Open Access Journals (Sweden)

    Malovrh Tadej

    2005-01-01

    Full Text Available Bovine leukaemia virus (BLV is a retrovirus that induces a chronic infection in cattle. Once infected, cattle remain virus carriers for life and start to show an antibody response within a few weeks after infection. Eradication and control of the disease are based on early diagnostics and segregation of the carriers. The choice of a diagnostic method depends on the eradication programme, money resources and characteristics of the herd to be analysed. The agar gel immunodiffusion (AGID test has been the serological test of choice for routine diagnosis of serum samples. Nevertheless, in more recent years, the enzyme-linked immunosorbent assay (ELISA has replaced the AGID for large scale testing. For this purpose, commercially available BLV-ELISA kits were compared to the AGID and to the polymerase chain reaction (PCR method performed with two sets of primers, amplifying env region. The ELISA kit based on the p24 core protein was found to be less specific and served as a screening test. The ELISA kit based on the envelope glycoprotein (gpSI served as a verification test and gave a good correlation with the AGID test and PCR method. However, ELISA showed a higher sensitivity than AGID. The p24 based ELiSA was useful for screening a large number of samples, whereas gp51 based ELISA, AGID and PCR were more important for detecting the antibody response against the individual BLV-proteins and therefore for verification of the infection with BLV.

  3. Thermal, mechanical, and physical properties of seaweed/sugar palm fibre reinforced thermoplastic sugar palm Starch/Agar hybrid composites.

    Science.gov (United States)

    Jumaidin, Ridhwan; Sapuan, Salit M; Jawaid, Mohammad; Ishak, Mohamad R; Sahari, Japar

    2017-04-01

    The aim of this research is to investigate the effect of sugar palm fibre (SPF) on the mechanical, thermal and physical properties of seaweed/thermoplastic sugar palm starch agar (TPSA) composites. Hybridized seaweed/SPF filler at weight ratio of 25:75, 50:50 and 75:25 were prepared using TPSA as a matrix. Mechanical, thermal and physical properties of hybrid composites were carried out. Obtained results indicated that hybrid composites display improved tensile and flexural properties accompanied with lower impact resistance. The highest tensile (17.74MPa) and flexural strength (31.24MPa) was obtained from hybrid composite with 50:50 ratio of seaweed/SPF. Good fibre-matrix bonding was evident in the scanning electron microscopy (SEM) micrograph of the hybrid composites' tensile fracture. Fourier transform infrared spectroscopy (FT-IR) analysis showed increase in intermolecular hydrogen bonding following the addition of SPF. Thermal stability of hybrid composites was enhanced, indicated by a higher onset degradation temperature (259°C) for 25:75 seaweed/SPF composites than the individual seaweed composites (253°C). Water absorption, thickness swelling, water solubility, and soil burial tests showed higher water and biodegradation resistance of the hybrid composites. Overall, the hybridization of SPF with seaweed/TPSA composites enhances the properties of the biocomposites for short-life application; that is, disposable tray, plate, etc. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Kinetics and equilibrium modelling of lead uptake by algae Gelidium and algal waste from agar extraction industry.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2007-05-08

    Pb(II) biosorption onto algae Gelidium, algal waste from agar extraction industry and a composite material was studied. Discrete and continuous site distribution models were used to describe the biosorption equilibrium at different pH (5.3, 4 and 3), considering competition among Pb(II) ions and protons. The affinity distribution function of Pb(II) on the active sites was calculated by the Sips distribution. The Langmuir equilibrium constant was compared with the apparent affinity calculated by the discrete model, showing higher affinity for lead ions at higher pH values. Kinetic experiments were conducted at initial Pb(II) concentrations of 29-104 mgl(-1) and data fitted to pseudo-first Lagergren and second-order models. The adsorptive behaviour of biosorbent particles was modelled using a batch mass transfer kinetic model, which successfully predicts Pb(II) concentration profiles at different initial lead concentration and pH, and provides significant insights on the biosorbents performance. Average values of homogeneous diffusivity, D(h), are 3.6 x 10(-8); 6.1 x 10(-8) and 2.4 x 10(-8)cm(2)s(-1), respectively, for Gelidium, algal waste and composite material. The concentration of lead inside biosorbent particles follows a parabolic profile that becomes linear near equilibrium.

  5. Kinetics and equilibrium modelling of lead uptake by algae Gelidium and algal waste from agar extraction industry

    International Nuclear Information System (INIS)

    Vilar, Vitor J.P.; Botelho, Cidalia M.S.; Boaventura, Rui A.R.

    2007-01-01

    Pb(II) biosorption onto algae Gelidium, algal waste from agar extraction industry and a composite material was studied. Discrete and continuous site distribution models were used to describe the biosorption equilibrium at different pH (5.3, 4 and 3), considering competition among Pb(II) ions and protons. The affinity distribution function of Pb(II) on the active sites was calculated by the Sips distribution. The Langmuir equilibrium constant was compared with the apparent affinity calculated by the discrete model, showing higher affinity for lead ions at higher pH values. Kinetic experiments were conducted at initial Pb(II) concentrations of 29-104 mg l -1 and data fitted to pseudo-first Lagergren and second-order models. The adsorptive behaviour of biosorbent particles was modelled using a batch mass transfer kinetic model, which successfully predicts Pb(II) concentration profiles at different initial lead concentration and pH, and provides significant insights on the biosorbents performance. Average values of homogeneous diffusivity, D h , are 3.6 x 10 -8 ; 6.1 x 10 -8 and 2.4 x 10 -8 cm 2 s -1 , respectively, for Gelidium, algal waste and composite material. The concentration of lead inside biosorbent particles follows a parabolic profile that becomes linear near equilibrium

  6. Kinetics and equilibrium modelling of lead uptake by algae Gelidium and algal waste from agar extraction industry

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Vitor J.P. [Laboratory of Separation and Reaction Engineering (LSRE), Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Botelho, Cidalia M.S. [Laboratory of Separation and Reaction Engineering (LSRE), Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Boaventura, Rui A.R. [Laboratory of Separation and Reaction Engineering (LSRE), Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)]. E-mail: bventura@fe.up.pt

    2007-05-08

    Pb(II) biosorption onto algae Gelidium, algal waste from agar extraction industry and a composite material was studied. Discrete and continuous site distribution models were used to describe the biosorption equilibrium at different pH (5.3, 4 and 3), considering competition among Pb(II) ions and protons. The affinity distribution function of Pb(II) on the active sites was calculated by the Sips distribution. The Langmuir equilibrium constant was compared with the apparent affinity calculated by the discrete model, showing higher affinity for lead ions at higher pH values. Kinetic experiments were conducted at initial Pb(II) concentrations of 29-104 mg l{sup -1} and data fitted to pseudo-first Lagergren and second-order models. The adsorptive behaviour of biosorbent particles was modelled using a batch mass transfer kinetic model, which successfully predicts Pb(II) concentration profiles at different initial lead concentration and pH, and provides significant insights on the biosorbents performance. Average values of homogeneous diffusivity, D {sub h}, are 3.6 x 10{sup -8}; 6.1 x 10{sup -8} and 2.4 x 10{sup -8} cm{sup 2} s{sup -1}, respectively, for Gelidium, algal waste and composite material. The concentration of lead inside biosorbent particles follows a parabolic profile that becomes linear near equilibrium.

  7. Mitogenomes from type specimens, a genotyping tool for morphologically simple species: ten genomes of agar-producing red algae.

    Science.gov (United States)

    Boo, Ga Hun; Hughey, Jeffery R; Miller, Kathy Ann; Boo, Sung Min

    2016-10-14

    DNA sequences from type specimens provide independent, objective characters that enhance the value of type specimens and permit the correct application of species names to phylogenetic clades and specimens. We provide mitochondrial genomes (mitogenomes) from archival type specimens of ten species in agar-producing red algal genera Gelidium and Pterocladiella. The genomes contain 43-44 genes, ranging in size from 24,910 to 24,970 bp with highly conserved gene synteny. Low Ka/Ks ratios of apocytochrome b and cytochrome oxidase genes support their utility as markers. Phylogenies of mitogenomes and cox1+rbcL sequences clarified classification at the genus and species levels. Three species formerly in Gelidium and Pterocladia are transferred to Pterocladiella: P. media comb. nov., P. musciformis comb. nov., and P. luxurians comb. and stat. nov. Gelidium sinicola is merged with G. coulteri because they share identical cox1 and rbcL sequences. We describe a new species, Gelidium millariana sp. nov., previously identified as G. isabelae from Australia. We demonstrate that mitogenomes from type specimens provide a new tool for typifying species in the Gelidiales and that there is an urgent need for analyzing mitogenomes from type specimens of red algae and other morphologically simple organisms for insight into their nomenclature, taxonomy and evolution.

  8. Comparison of different agar diffusion methods for the detection of residues in the kidneys of pigs treated with antimicrobial drugs.

    Science.gov (United States)

    Korkeala, H; Sorvettula, O; Mäki-Petäys, O; Hirn, J

    1983-01-01

    Residue analyses of the kidneys of twenty-six pigs treated with various antimicrobial drugs 20 h before slaughter and of eleven untreated pigs were performed. The effects of storage temperature of the kidneys, and of sampling location, on the residue analysis were also studied. No method alone was sufficient for the detection of residues. Oxytetracycline residues could be detected at pH 6, dihydrostreptomycin residues at pH 8, and sulphonamide residues if trimethoprim was present in the medium. Chloramphenicol, penicillin G procaine, tylosin and lincomycin residues were not detectable with the methods used. The concentration of ampicillin decreased during the storage of samples at +4°C. Most methods also yielded zones of inhibition for the frozen kidneys from untreated pigs. It seems necessary to use agar media of two different pH values: the addition of trimethoprim to the medium is also needed. The use of fresh pig kidneys, and samples containing both kidney medulla and kidney cortex, is recommended in residue analysis. Copyright © 1983. Published by Elsevier Ltd.

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

    Science.gov (United States)

    Mirajkar, Nandita S; Gebhart, Connie J

    2016-03-01

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

  10. The effectiveness of processed grapefruit-seed extract as an antibacterial agent: I. An in vitro agar assay.

    Science.gov (United States)

    Reagor, Lee; Gusman, Jean; McCoy, Lana; Carino, Edith; Heggers, John P

    2002-06-01

    Grapefruit-seed extract (GSE) Citricidal has, in recent reports, been reported to be successful in combating a variety of common infectious agents. In our study, drops of concentrated grapefruit-seed extract were tested for antibacterial properties against a number of gram-positive and gram-negative organisms. Sixty-seven (67) distinct biotypes were tested for their susceptibilities to the GSE as well as to 5 other topical antibacterials (Silvadene, Sulfamylon, Bactroban, Nitrofurazone, and Silvadene, Nystatin). Wells were punched into Mueller-Hinton agar plates, which were then inoculated with the organism to be tested; each well was then inoculated with one of the antibacterial agents. After an overnight incubation period, the plates were checked for zones of bacterial susceptibility around the individual wells, with a measured susceptibility zone diameter of 10 mm or more considered a positive result. The GSE was consistently antibacterial against all of the biotypes tested, with susceptibility zone diameters equal to or greater than 15 mm in each case. Our preliminary data thus suggest an antibacterial characteristic to GSE that is comparable to that of proven topical antibacterials. Although the GSE appeared to have a somewhat greater inhibitory effect on gram-positive organisms than on gram-negative organisms, its comparative effectiveness against a wide range of bacterial biotypes is significant.

  11. Effect of seaweed on mechanical, thermal, and biodegradation properties of thermoplastic sugar palm starch/agar composites.

    Science.gov (United States)

    Jumaidin, Ridhwan; Sapuan, Salit M; Jawaid, Mohammad; Ishak, Mohamad R; Sahari, Japar

    2017-06-01

    The aim of this paper is to investigate the characteristics of thermoplastic sugar palm starch/agar (TPSA) blend containing Eucheuma cottonii seaweed waste as biofiller. The composites were prepared by melt-mixing and hot pressing at 140°C for 10min. The TPSA/seaweed composites were characterized for their mechanical, thermal and biodegradation properties. Incorporation of seaweed from 0 to 40wt.% has significantly improved the tensile, flexural, and impact properties of the TPSA/seaweed composites. Scanning electron micrograph of the tensile fracture showed homogeneous surface with formation of cleavage plane. It is also evident from TGA results that thermal stability of the composites were enhanced with addition of seaweed. After soil burial for 2 and 4 weeks, the biodegradation of the composites was enhanced with addition of seaweed. Overall, the incorporation of seaweed into TPSA enhances the properties of TPSA for short-life product application such as tray, plate, etc. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. The use of antibiotics to improve phage detection and enumeration by the double-layer agar technique

    Directory of Open Access Journals (Sweden)

    Ferreira Eugénio C

    2009-07-01

    Full Text Available Abstract Background The Double-Layer Agar (DLA technique is extensively used in phage research to enumerate and identify phages and to isolate mutants and new phages. Many phages form large and well-defined plaques that are easily observed so that they can be enumerated when plated by the DLA technique. However, some give rise to small and turbid plaques that are very difficult to detect and count. To overcome these problems, some authors have suggested the use of dyes to improve the contrast between the plaques and the turbid host lawns. It has been reported that some antibiotics stimulate bacteria to produce phages, resulting in an increase in final titer. Thus, antibiotics might contribute to increasing plaque size in solid media. Results Antibiotics with different mechanisms of action were tested for their ability to enhance plaque morphology without suppressing phage development. Some antibiotics increased the phage plaque surface by up to 50-fold. Conclusion This work presents a modification of the DLA technique that can be used routinely in the laboratory, leading to a more accurate enumeration of phages that would be difficult or even impossible otherwise.

  13. Microanalysis of Organic Pigments in Ancient Textiles by Surface-Enhanced Raman Scattering on Agar Gel Matrices

    Directory of Open Access Journals (Sweden)

    Marilena Ricci

    2016-01-01

    Full Text Available We review some new methods based on surface-enhanced Raman scattering (SERS for the nondestructive/minimally invasive identification of organic colorants in objects whose value or function precludes sampling, such as historic and archeological textiles, paintings, and drawing. We discuss in detail the methodology we developed for the selective extraction and identification of anthraquinones and indigoids in the typical concentration used in textiles by means of an ecocompatible homogeneous nanostructured agar matrix. The extraction system was modulated according to the chemical properties of the target analyte by choosing appropriate reagents for the extraction and optimizing the extraction time. The system has been found to be extremely stable, easy to use and produce, easy to store, and at the same time able to be analyzed even after long time intervals, maintaining its enhancement properties unaltered, without the detriment of the extracted compound. Highly structured SERS band intensities have been obtained from the extracted dyes adopting laser light excitations at 514.5 and 785 nm of a micro-Raman setup. This analytical method has been found to be extremely safe for the analyzed substrates, thus being a promising procedure for the selective analysis and detection of molecules at low concentration in the field of artworks conservation.

  14. Synthesis and characterization of high-surface-area millimeter-sized silica beads with hierarchical multi-modal pore structure by the addition of agar

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yosep; Choi, Junhyun [Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 561–756 (Korea, Republic of); Tong, Meiping, E-mail: tongmeiping@iee.pku.edu.cn [The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871 (China); Kim, Hyunjung, E-mail: kshjkim@jbnu.ac.kr [Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 561–756 (Korea, Republic of)

    2014-04-01

    Millimeter-sized spherical silica foams (SSFs) with hierarchical multi-modal pore structure featuring high specific surface area and ordered mesoporous frameworks were successfully prepared using aqueous agar addition, foaming and drop-in-oil processes. The pore-related properties of the prepared spherical silica (SSs) and SSFs were systematically characterized by field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), small-angle X-ray diffraction (SAXRD), Hg intrusion porosimetry, and N{sub 2} adsorption–desorption isotherm measurements. Improvements in the BET surface area and total pore volume were observed at 504 m{sup 2} g{sup −1} and 5.45 cm{sup 3} g{sup −1}, respectively, after an agar addition and foaming process. Despite the increase in the BET surface area, the mesopore wall thickness and the pore size of the mesopores generated from the block copolymer with agar addition were unchanged based on the SAXRD, TEM, and BJH methods. The SSFs prepared in the present study were confirmed to have improved BET surface area and micropore volume through the agar loading, and to exhibit interconnected 3-dimensional network macropore structure leading to the enhancement of total porosity and BET surface area via the foaming process. - Highlights: • Millimeter-sized spherical silica foams (SSFs) are successfully prepared. • SSFs exhibit high BET surface area and ordered hierarchical pore structure. • Agar addition improves BET surface area and micropore volume of SSFs. • Foaming process generates interconnected 3-D network macropore structure of SSFs.

  15. The effect of reuterin on the lag time of single cells of Listeria innocua grown on a solid agar surface at different pH and NaCl concentrations

    DEFF Research Database (Denmark)

    Rasch, Maria; Metris, A.; Baranyi, J.

    2007-01-01

    The lag time of single cells of Listeria innocua grown on the surface of Brain Heart Infusion Agar was studied by microscopy and image analysis. An experimental set-up that enabled relocation of the cells on the agar surface was developed and used to collect data from 50 to 100 individual cells...... the predictions of microbial growth on solid food matrices....

  16. The importance of matrix-assisted laser desorption ionization–time of flight mass spectrometry for correct identification of Clostridium difficile isolated from chromID C. difficile chromogenic agar

    Directory of Open Access Journals (Sweden)

    Jonathan H.K. Chen

    2017-10-01

    Full Text Available The clinical workflow of using chromogenic agar and matrix-assisted laser desorption ionization time-of-fight mass spectrometry (MALDI-TOF MS for Clostridium difficile identification was evaluated. The addition of MALDI-TOF MS identification after the chromID C. difficile chromogenic agar culture could significantly improve the diagnostic accuracy of C. difficile.

  17. Thin-layer agar (TL7H11 for rapid isolation of Mycobacterium tuberculosis in sputum specimens

    Directory of Open Access Journals (Sweden)

    Habiba Binte Alam

    2016-08-01

    Full Text Available Background: Tuberculosis (TB remains one of the major causes of death from a single infectious agent worldwide. The early detection of new cases of pulmonary tuberculosis is an important goal in tuberculosis control program.Objective: 1n this study, thin layer agar (TLA culture was compared with Lowenstein-Jensen (LJ culture for rapid detection of pulmonary tuberculosis. Methods: It was a cross sectional study conducted in National Tuberculosis Reference Labora­tory (NTRL of National Institute of Disease of Chest and Hospital (NIDCH, Dhaka, from July 2010 to June 2011. A total of 100 sputum smear positive for acid fast bacilli (AFB by Z-N staining, pulmonary tuberculosis patients were included in this study. Samples were processed by modified Petroff method and then cultured on thin layer 7H11(TL7H11 plates and L-J tubes. TL7H11 plates were observed microscopically for rnicrocolony growth once a week for 6 weeks, and L-J tubes were observed once a week for 8 weeks. Results: The recovery rates of mycobacteria on only TLA, only LJ and on both media were 90%, 97% and 88% respectively. Overall positivity was 99% in both L-J and TLA media. Mean time for detection of mycobacteria on TLA was 9.04±1.66 days compared to 21.78±6.19 days on L-J media. The rate of contamination was higher (6% in L-J media than in TLA media (4%. Conclusion: The TL7H11 media can be used as an alternative to the Lowenstein-Jensen medium for early isolation of mycobacteria in resource constrained settings.

  18. Study of chemical interaction induced by ionizing radiation poly(dimethylsiloxane-g-ethylene oxide) in the poly(n-vinyl-2-pyrrolidone) and agar membrane; Estudo da interacao quimica do poli(dimetilsiloxano-g-oxido de etileno) na membrana de poli(n-vinil-2-pirrolidona) e agar induzida com radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Bazzi, Aurea de Souza

    1999-07-01

    Membrane composed by poly(N-vinyl-2-pyrrolidone) (PVP) and agar was formulated with and without poly(dimethylsiloxane-g-ethylene oxide) (SEO) irradiated with electron beam with doses between 10-50 kGy. The radiolytic behaviour of each component, PVP, agar and SEO, was studied when irradiated by gamma ray, in the absence and presence of air and water, by electron paramagnetic resonance (EPR) at 77 K. The chemical interaction of SEO with PVP/agar membrane was investigated by: infrared spectroscopy, energy dispersive X-ray fluorescence, dynamic-mechanical analysis, scanning electron microscopy, gel and swelling analysis. The cytotoxicity of the PVP/agar/SEO membrane was evaluated by cellular suppression. The membrane radicals from PVP ({phi}NC.) and from water (H., OH. and H{sub 2}O) was observed by EPR at 77K. The agar radicals formed by hydrogen abstraction of C{sub 1} and C{sub 3} of {beta}-D-galactose and/or C{sub 1} and C{sub 4} of {alpha}-L-galactose, reacted primarily with water radicals in despite of they also took part in the membrane by chemical bond. The radicals from SEO (.CH{sub 2}{approx}, .Si{approx}, .O{approx}) participated in the inter and intramolecular crosslinking as co-crosslinker by polymeric bridge. The co-crosslinked action depended on its concentration associated to PVP concentration. The presence op acrylates increases the tensile break of the PVP/agar/SEO membrane significantly. (author)

  19. Effects of Agar Gel Strength and Fat on Oral Breakdown, Volatile Release, and Sensory Perception Using in Vivo and in Vitro Systems.

    Science.gov (United States)

    Frank, Damian; Eyres, Graham T; Piyasiri, Udayasika; Cochet-Broch, Maeva; Delahunty, Conor M; Lundin, Leif; Appelqvist, Ingrid M

    2015-10-21

    The density and composition of a food matrix affect the rates of oral breakdown and in-mouth flavor release as well as the overall sensory experience. Agar gels of increasing concentration (1.0, 1.7, 2.9, and 5% agarose) with and without added fat (0, 2, 5, and 10%) were spiked with seven aroma volatiles. Differences in oral processing and sensory perception were systematically measured by a trained panel using a discrete interval time intensity method. Volatile release was measured in vivo and in vitro by proton transfer reaction mass spectrometry. Greater oral processing was required as agar gel strength increased, and the intensity of flavor-related sensory attributes decreased. Volatile release was inversely related to gel strength, showing that physicochemical phenomena were the main mechanisms underlying the perceived sensory changes. Fat addition reduced the amount of oral processing and had differential effects on release, depending on the fat solubility or lipophilicity of the volatiles.

  20. Determination of Trimethoprim-Sulfamethoxazole Resistance in Streptococcus pneumoniae by Using the E Test with Mueller-Hinton Agar Supplemented with Sheep or Horse Blood May Be Unreliable

    Science.gov (United States)

    Lovgren, M.; Dell’Acqua, L.; Palacio, R.; Echániz-Aviles, G.; Soto-Noguerón, A.; Castañeda, E.; Agudelo, C. I.; Heitmann, I.; Brandileone, M. C.; Zanella, R. C.; Rossi, A.; Pace, J.; Talbot, J. A.

    1999-01-01

    An international, multicenter study compared trimethoprim-sulfamethoxazole MICs for 743 Streptococcus pneumoniae isolates (107 to 244 isolates per country) by E test, using Mueller-Hinton agar supplemented with 5% defibrinated horse blood or 5% defibrinated sheep blood, with MICs determined by the National Committee for Clinical Laboratory Standards broth microdilution reference method. Agreement within 1 log2 dilution and minor error rates were 69.3 and 15.5%, respectively, on sheep blood-supplemented agar and 76.9 and 13.6%, respectively, with horse blood as the supplement. Significant interlaboratory variability was observed. E test may not be a reliable method for determining the resistance of pneumococci to trimethoprim-sulfamethoxazole. PMID:9854095

  1. Historical sources about diseases, death and embalming regarding the family of Jean Antoine Michel Agar, Minister of Finance of Gioacchino Murat.

    Science.gov (United States)

    Marinozzi, S; Gazzaniga, V; Giuffra, V; Fornaciari, G

    2011-06-01

    Among the mummies preserved in the Basilica of San Domenico Maggiore in Naples, there are the bodies of the wife and three children of Jean Antoine Michel Agar, Minister of Finance of Naple's Kingdom during the Monarchy of Joachim Murat (1808-1815). Between 1983 and 1987 paleopathological analyses were performed; in particular, X-ray examination allowed investigation of the health status of the Agar family members and reconstruction of the embalming processes used to preserve the bodies. In addition, an analysis of the historical and archival documents was carried out, to formulate hypotheses about the causes of death, demonstrating how these sources could become important instruments to obtain diagnoses and pathological histories.

  2. CONTRIBUTION TO DETERMINING THE BIOCHEMICAL COMPOSITION OF THE WATER CHESTNUT TRAPA NATANS L. LAKE OUBEIRA EL-KALA AND DEVELOPMENT OF NUTRIENT AGAR

    Directory of Open Access Journals (Sweden)

    MOHAMED SAHLI

    2015-10-01

    Full Text Available This work is aims to determining the biochemical composition of the flour water chestnut seeds and the development of a nutrient agar for bacteria and fungi in the presence and absence of oxytetracycline. The culture medium consists of the filtrate recovered after dispersion of the flour of the seeds in distilled water and the agar. The results show in the absence of oxytetracycline, bacterial and fungal strains develop. In the presence of the antibiotic to 0.25 mg·mL-1 and 0.5 mg·mL-1 bacteria are completely inhibited whereas fungi evolve. Statistical analysis reveals the existence of a very highly significant difference (P ≤ 0.001 between the effects of different concentrations of the bactericide deploying Pyrenophora tritici and Septoria nodorum. There is no influence of antibacterial concentrations on the growth of Fusarium sp.

  3. Effect of Nano-ZnO Particle Suspension on Growth of Mung (Vigna radiata and Gram (Cicer arietinum Seedlings Using Plant Agar Method

    Directory of Open Access Journals (Sweden)

    Pramod Mahajan

    2011-01-01

    Full Text Available The present study demonstrates an effect of nano-ZnO particles on the growth of plant seedlings of mung (Vigna radiate and gram (Cicer arietinum. The study was carried out in plant agar media to prevent precipitation of water-insoluble nanoparticles in the test units. Various concentrations of nano-ZnO particles in suspension form were introduced to the agar media, and their effect on the root and shoot growth of the seedlings was examined. The main experimental approach, using correlative light and scanning electron microscopy provided evidence of adsorption of nanoparticles on the root surface. Absorption of nanoparticles by seedlings root was also detected by inductive coupled plasma/atomic emission spectroscopy (ICP-AES. It was found that at certain optimum concentration, the seedlings displayed good growth over control, and beyond that, retardation in growth was observed.

  4. Increase in colony-forming efficiency in soft agar of thymus cells from radiation-induced thymomas of NIH Swiss mice

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Nobuko; Takamori, Yasuhiko; Hori, Yasuharu [Radiation Center of Osaka Prefecture, Sakai (Japan)

    1982-03-01

    Colony-forming efficiency in soft agar of radiation-induced thymoma in NIH Swiss mice was determined in the presence of cultured medium of reticulo-epitherial cells from normal thymus of NIH Swiss mouse as conditioned medium. A similar experiment was done with thymomas spontaneously developed in AKR mice. Most of colonies developed in soft agar were not composed of thymic lymphoma cells, but of macrophage-like cells. The ratio of the number of colonies to that of the seeded cells significantly increased in thymomas comparing with that in normal thymus. This result corresponded with the increased number of macrophages in thymoma, as determined by counting phagocytic cells of adherent cells.

  5. Multicentre validation of 4-well azole agar plates as a screening method for detection of clinically relevant azole-resistant Aspergillus fumigatus

    DEFF Research Database (Denmark)

    Arendrup, Maiken Cavling; Verweij, Paul E; Mouton, Johan W

    2017-01-01

    Objectives: Azole-resistant Aspergillus fumigatus is emerging worldwide. Reference susceptibility testing methods are technically demanding and no validated commercial susceptibility tests for moulds currently exist. In this multicentre study a 4-well azole-containing screening agar method...... following E.Def 9.3. In-house and commercial 4-well plates containing agars supplemented with 4 mg/L itraconazole, 1 mg/L voriconazole, 0.5 mg/L posaconazole and no antifungal, respectively, were evaluated. Growth was scored (0-3) by two independent observers in three laboratories. Inter-plate, inter...... agreement (no growth versus growth) was excellent (median 95%-100%, range 87%-100%, overall). The overall sensitivity and specificity for the 4-well plate (no growth versus growth) was 99% (range 97%-100%) and 99% (95%-100%), respectively. The sensitivity for simulated WT/mutant specimens was 94% (range 83...

  6. Comparison of Two Different Disk Diffusion Agar Tests in Determination of Antibiotic Susceptibility for E-Coli Isolated from Urinary Tract Infection in Pediatrics

    Directory of Open Access Journals (Sweden)

    I. Sedighi

    2010-04-01

    Full Text Available Introduction & Objective: Urinary Tract Infection (UTI is one of the most common infections during childhood and E-Coli is the more predominant pathogen recovered in UTI. Disk Diffusion agar test is a method of choice because it is cost effective, simple, and now routinely used for detection of antibiotic susceptibility. A rapid increase in antibiotic resistance in our region made the authors to design a study to compare this traditional method with two different disk diffusion agar tests.Materials & Methods: Our study was conducted between 2009 and 2010 in Be’sat teaching hospital on 100 pediatric patients ranged 15 days to 13 years old with positive urine culture for E-coli. Antibiogram detection was performed by disk diffusion agar test with two different kits as Padtan-Teb (made in Iran and Mast (made in the U.K. for Co-trimoxazol, Amikacin, Ceftriaxone, Nalidixic Acid, Cefixime, and Nitrofurantoin. At last the data was analyzed by McNemar test.Results: Co-trimoxazol obtained the lowest (23% Padtan-Teb and 26% Mast and Nitrofurantoin had the highest (86% Padtan-Teb and 97% Mast sensitivity in the two methods which were used in our study. The results were statistically significant for Amikacin, Ceftriaxone, Cefixime, and Nitrofurantoin. The data was analyzed by Mc Memar test.Conclusion: According to our study the results of antibiotic susceptibility were more compatible with other non national Disk diffusion agar test and thus we recommend that our manufactures in Iran should increase the quality of their products.

  7. Comparison of M.I.C.E. and Etest with CLSI agar dilution for antimicrobial susceptibility testing against oxacillin-resistant Staphylococcus spp.

    Directory of Open Access Journals (Sweden)

    Eloiza H Campana

    Full Text Available OBJECTIVE: The main objective of this study was to comparatively evaluate the performance of M.I.C.E. and Etest methodologies to that of agar dilution for determining the antimicrobial susceptibility profile of oxacillin-resistant Staphylococcus spp. METHODS: A total of 100 oxacillin-resistant Staphylococcus spp. isolates were collected from hospitalized patients at a teaching hospital. Antimicrobial susceptibility testing for vancomycin, teicoplanin and linezolid was performed using the reference CLSI agar dilution method (2009, Etest and M.I.C.E. methodologies. The MIC values were interpreted according to CLSI susceptibility breakpoints and compared by regression analysis. RESULTS: In general, the essential agreement (±1-log2 between M.I.C.E. and CLSI agar dilution was 93.0%, 84.0% and 77.0% for linezolid, teicoplanin and vancomycin, respectively. Essential agreement rates between M.I.C.E. and Etest were excellent (>90.0% for all antibiotics tested. Both strips (M.I.C.E. and Etest yielded two very major errors for linezolid. Unacceptable minor rates were observed for teicoplanin against CoNS and for vancomycin against S. aureus. CONCLUSIONS: According to our results, linezolid and teicoplanin MICs against all staphylococci and S. aureus, respectively, were more accurately predicted by M.I.C.E. strips. However, the Etest showed better performance than M.I.C.E. for predicting vancomycin MICs against all staphylococci. Thus, microbiologists must be aware of the different performance of commercially available gradient strips against staphylococci.

  8. Optimization of decolorization process in agar production from Gracilaria lemaneiformis and evaluation of antioxidant activities of the extract rich in natural pigments.

    Science.gov (United States)

    Yuan, Shengliang; Duan, Zhihong; Lu, Yingnian; Ma, Xiaoli; Wang, Sheng

    2018-01-01

    Gracilaria lemaneiformis is mainly used as a raw material source for agar industry, and its extract is rich in natural pigments with antioxidant activities. In this study, a solvent reflux extraction method for decolorization of G. lemaneiformis has been developed in agar production. The extraction conditions were optimized as follows: solvent-to-material ratio, 50:1; ethanol concentration, 70%; number of extractions, 3; extraction time, 0.5 h, under which the total antioxidant yield of the extract reached 2.89 ± 0.88 mg/g dried seaweeds. Their IC 50 values of DPPH radical scavenging activity, hydroxyl radical scavenging activity and superoxide anion scavenging activity were 21.91 ± 1.8 mg/L, 40.59 ± 1.5 mg/L and 160.87 ± 2.8 mg/L, respectively. Further isolation and spectroscopic analysis of natural pigments suggested the strong antioxidant capacities were attributed to chlorophyll derivatives. The results indicate that the decolorization process was able to improve the agar quality, and the extract containing lots of natural pigments had antioxidant activities which may be used in functional food and cosmetics.

  9. Potato dextrose agar antifungal susceptibility testing for yeasts and molds: evaluation of phosphate effect on antifungal activity of CMT-3.

    Science.gov (United States)

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

    2002-05-01

    The broth macrodilution method (BMM) for antifungal susceptibility testing, approved by the National Committee for Clinical Laboratory Standards (NCCLS), was found to have deficiencies in testing of the antifungal activity of a new type of antifungal agent, a nonantibacterial chemically modified tetracycline (CMT-3). The high content of phosphate in the medium was found to greatly increase the MICs of CMT-3. To avoid the interference of phosphate in the test, a new method using potato dextrose agar (PDA) as a culture medium was developed. Eight strains of fungi, including five American Type Culture Collection strains and three clinical isolates, were used to determine the MICs of amphotericin B and itraconazole with both the BMM and the PDA methods. The MICs of the two antifungal agents determined with the PDA method showed 99% agreement with those determined with the BMM method within 1 log(2) dilution. Similarly, the overall reproducibility of the MICs with the PDA method was above 97%. Three other antifungal agents, fluconazole, ketoconazole, and CMT-3, were also tested in parallel against yeasts and molds with both the BMM and the PDA methods. The MICs of fluconazole and ketoconazole determined with the PDA method showed 100% agreement within 1 log(2) dilution of those obtained with the BMM method. However, the MICs of CMT-3 determined with the BMM method were as high as 128 times those determined with the PDA method. The effect of phosphate on the antifungal activity of CMT-3 was evaluated by adding Na2HPO4 to PDA in the new method. It was found that the MIC of CMT-3 against a Penicillium sp. increased from 0.5 microg/ml (control) to 2.0 microg/ml when the added phosphate was used at a concentration of 0.8 mg/ml, indicating a strong interference of Na2HPO4 with the antifungal activity of CMT-3. Except for fluconazole, all the other antifungal agents demonstrated clear end points among the yeasts and molds tested. Nevertheless, with its high reproducibility

  10. Comparing Diagnostic Accuracy of Kato-Katz, Koga Agar Plate, Ether-Concentration, and FLOTAC for Schistosoma mansoni and Soil-Transmitted Helminths

    Science.gov (United States)

    Glinz, Dominik; Silué, Kigbafori D.; Knopp, Stefanie; Lohourignon, Laurent K.; Yao, Kouassi P.; Steinmann, Peter; Rinaldi, Laura; Cringoli, Giuseppe; N'Goran, Eliézer K.; Utzinger, Jürg

    2010-01-01

    Background Infections with schistosomes and soil-transmitted helminths exert a considerable yet underappreciated economic and public health burden on afflicted populations. Accurate diagnosis is crucial for patient management, drug efficacy evaluations, and monitoring of large-scale community-based control programs. Methods/Principal Findings The diagnostic accuracy of four copromicroscopic techniques (i.e., Kato-Katz, Koga agar plate, ether-concentration, and FLOTAC) for the detection of Schistosoma mansoni and soil-transmitted helminth eggs was compared using stool samples from 112 school children in Côte d'Ivoire. Combined results of all four methods served as a diagnostic ‘gold’ standard and revealed prevalences of S. mansoni, hookworm, Trichuris trichiura, Strongyloides stercoralis and Ascaris lumbricoides of 83.0%, 55.4%, 40.2%, 33.9% and 28.6%, respectively. A single FLOTAC from stool samples preserved in sodium acetate-acetic acid-formalin for 30 or 83 days showed a higher sensitivity for S. mansoni diagnosis (91.4%) than the ether-concentration method on stool samples preserved for 40 days (85.0%) or triplicate Kato-Katz using fresh stool samples (77.4%). Moreover, a single FLOTAC detected hookworm, A. lumbricoides and T. trichiura infections with a higher sensitivity than any of the other methods used, but resulted in lower egg counts. The Koga agar plate method was the most accurate diagnostic assay for S. stercoralis. Conclusion/Significance We have shown that the FLOTAC method holds promise for the diagnosis of S. mansoni. Moreover, our study confirms that FLOTAC is a sensitive technique for detection of common soil-transmitted helminths. For the diagnosis of S. stercoralis, the Koga agar plate method remains the method of choice. PMID:20651931

  11. Investigation of the effect of power ultrasound on the nucleation of water during freezing of agar gel samples in tubing vials.

    Science.gov (United States)

    Kiani, Hossein; Sun, Da-Wen; Delgado, Adriana; Zhang, Zhihang

    2012-05-01

    Nucleation, as an important stage of freezing process, can be induced by the irradiation of power ultrasound. In this study, the effect of irradiation temperature (-2 °C, -3 °C, -4 °C and -5 °C), irradiation duration (0s, 1s, 3s, 5s, 10s or 15s) and ultrasound intensity (0.07 W cm(-2), 0.14 W cm(-2), 0.25 W cm(-2), 0.35 W cm(-2) and 0.42 W cm(-2)) on the dynamic nucleation of ice in agar gel samples was studied. The samples were frozen in an ethylene glycol-water mixture (-20 °C) in an ultrasonic bath system after putting them into tubing vials. Results indicated that ultrasound irradiation is able to initiate nucleation at different supercooled temperatures (from -5 °C to -2 °C) in agar gel if optimum intensity and duration of ultrasound were chosen. Evaluation of the effect of 0.25 W cm(-2) ultrasound intensity and different durations of ultrasound application on agar gels showed that 1s was not long enough to induce nucleation, 3s induced the nucleation repeatedly but longer irradiation durations resulted in the generation of heat and therefore nucleation was postponed. Investigation of the effect of ultrasound intensity revealed that higher intensities of ultrasound were effective when a shorter period of irradiation was used, while lower intensities only resulted in nucleation when a longer irradiation time was applied. In addition to this, higher intensities were not effective at longer irradiation times due to the heat generated in the samples by the heating effect of ultrasound. In conclusion, the use of ultrasound as a means to control the crystallization process offers promising application in freezing of solid foods, however, optimum conditions should be selected. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Detection by hyperspectral imaging of shiga toxin-producing Escherichia coli serogroups O26, O45, O103, O111, O121, and O145 on rainbow agar.

    Science.gov (United States)

    Windham, William R; Yoon, Seung-Chul; Ladely, Scott R; Haley, Jennifer A; Heitschmidt, Jerry W; Lawrence, Kurt C; Park, Bosoon; Narrang, Neelam; Cray, William C

    2013-07-01

    The U.S. Department of Agriculture, Food Safety Inspection Service has determined that six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145) are adulterants in raw beef. Isolate and phenotypic discrimination of non-O157 STEC is problematic due to the lack of suitable agar media. The lack of distinct phenotypic color variation among non-O157serogroups cultured on chromogenic agar poses a challenge in selecting colonies for confirmation. In this study, visible and near-infrared hyperspectral imaging and chemometrics were used to detect and classify non-O157 STEC serogroups grown on Rainbow agar O157. The method was first developed by building spectral libraries for each serogroup obtained from ground-truth regions of interest representing the true identity of each pixel and thus each pure culture colony in the hyperspectral agar-plate image. The spectral library for the pure-culture non-O157 STEC consisted of 2,171 colonies, with spectra derived from 124,347 of pixels. The classification models for each serogroup were developed with a k nearest-neighbor classifier. The overall classification training accuracy at the colony level was 99%. The classifier was validated with ground beef enrichments artificially inoculated with 10, 50, and 100 CFU/ml STEC. The validation ground-truth regions of interest of the STEC target colonies consisted of 606 colonies, with 3,030 pixels of spectra. The overall classification accuracy was 98%. The average specificity of the method was 98% due to the low false-positive rate of 1.2%. The sensitivity ranged from 78 to 100% due to the false-negative rates of 22, 7, and 8% for O145, O45, and O26, respectively. This study showed the potential of visible and near-infrared hyperspectral imaging for detecting and classifying colonies of the six non-O157 STEC serogroups. The technique needs to be validated with bacterial cultures directly extracted from meat products and positive

  13. Effects of PVA, agar contents, and irradiation doses on properties of PVA/ws-chitosan/glycerol hydrogels made by γ-irradiation followed by freeze-thawing

    International Nuclear Information System (INIS)

    Yang Xiaomin; Zhu Zhiyong; Liu Qi; Chen Xiliang; Ma Mingwang

    2008-01-01

    Poly(vinyl alcohol) (PVA)/water soluble chitosan (ws-chitosan)/glycerol hydrogels were prepared by γ-irradiation and γ-irradiation followed by freeze-thawing, respectively. The effects of irradiation dose and the contents of PVA and agar on the swelling, rheological, and thermal properties of these hydrogels were investigated. The swelling capacity decreases while the mechanical strength increases with increasing PVA or agar content. Increasing the irradiation dose leads to an increase in chemical crosslinking density but a decrease in physical crosslinking density. Hydrogels made by irradiation followed by freeze-thawing own smaller swelling capacity but larger mechanical strength than those made by pure irradiation. The storage modulus of the former hydrogels decreases above 50 deg. C and above 70 deg. C it comes to the same value as that prepared by irradiation. The ordered association of PVA is influenced by both chemical and physical crosslinkings and by the presence of ws-chitosan and glycerol. These hydrogels are high sensitive to pH and ionic strength, indicating that they may be useful in stimuli-responsive drug release system

  14. A combined disc method with resazurin agar plate assay for early phenotypic screening of KPC, MBL and OXA-48 carbapenemases among Enterobacteriaceae.

    Science.gov (United States)

    Teethaisong, Y; Eumkeb, G; Nakouti, I; Evans, K; Hobbs, G

    2016-08-01

    To validate a combined disc method along with resazurin chromogenic agar for early screening and differentiation of Klebsiella pneumoniae carbapenemase, metallo-β-lactamase and OXA-48 carbapenemase-producing Enterobacteriaceae. The combined disc test comprising of meropenem alone and with EDTA, phenylboronic acid or both EDTA and phenylboronic acid, and temocillin alone were evaluated with the resazurin chromogenic agar plate assay against a total of 86 molecularly confirmed Enterobacteriaceae clinical isolates (11 metallo-β-lactamases, eight Kl. pneumoniae carbapenemases, 11 OXA-48, 32 AmpC and 15 extended-spectrum-β-lactamase producers and nine co-producers of extended-spectrum-β-lactamase and AmpC). The inhibition zone diameters were measured and interpreted at 7 h for the presence of carbapenemase. All carbapenemase producers were phenotypically distinguished by this assay with 100% sensitivity and specificity. This early phenotypic method is very simple, inexpensive, and reliable in the detection and differentiation of carbapenemase-producing Enterobacteriaceae. It could be exploited in any microbiological laboratory for diagnosis of these recalcitrant bacteria. This assay poses excellent performance in discrimination of Kl. pneumoniae carbapenemase, metallo-β-lactamase and OXA-48 carbapenemases within 7 h, which is much faster than conventional disc diffusion methods. The rapid detection could help clinicians screen patients, control infection and provide epidemiological surveillance. © 2016 The Society for Applied Microbiology.

  15. The fungicidal and phytotoxic properties of benomyl and PPM in supplemented agar media supporting transgenic arabidopsis plants for a Space Shuttle flight experiment

    Science.gov (United States)

    Paul, A. L.; Semer, C.; Kucharek, T.; Ferl, R. J.

    2001-01-01

    Fungal contamination is a significant problem in the use of sucrose-enriched agar-based media for plant culture, especially in closed habitats such as the Space Shuttle. While a variety of fungicides are commercially available, not all are equal in their effectiveness in inhibiting fungal contamination. In addition, fungicide effectiveness must be weighed against its phytotoxicity and in this case, its influence on transgene expression. In a series of experiments designed to optimize media composition for a recent shuttle mission, the fungicide benomyl and the biocide "Plant Preservative Mixture" (PPM) were evaluated for effectiveness in controlling three common fungal contaminants, as well as their impact on the growth and development of arabidopsis seedlings. Benomyl proved to be an effective inhibitor of all three contaminants in concentrations as low as 2 ppm (parts per million) within the agar medium, and no evidence of phytotoxicity was observed until concentrations exceeded 20 ppm. The biocide mix PPM was effective as a fungicide only at concentrations that had deleterious effects on arabidopsis seedlings. As a result of these findings, a concentration of 3 ppm benomyl was used in the media for experiment PGIM-01 which flew on shuttle Columbia mission STS-93 in July 1999.

  16. Antibiotic susceptibility of methicillin-resistant staphylococci (MRS) of food origin: A comparison of agar disc diffusion method and a commercially available miniaturized test.

    Science.gov (United States)

    Buzón-Durán, Laura; Capita, Rosa; Alonso-Calleja, Carlos

    2018-06-01

    Methicillin-resistant staphylococci (MRS) are a major concern to public and animal health. Thirty MRS (Staphylococcus aureus, S. cohnii, S. epidermidis, S. haemolyticus, S. hominis, S. lentus, S. lugdunensis, S. sciuri, and S. xylosus) isolates from meat and poultry preparations were tested for antimicrobial susceptibility to 11 antimicrobials (belonging to seven different categories) of clinical significance using both the standard agar disc diffusion method and a commercially available miniaturized system (Sensi Test Gram-positive). It is worth stressing that 16 isolates (53.33%) exhibited an extensively drug-resistant phenotype (XDR). The average number of resistances per strain was 4.67. These results suggest that retail meat and poultry preparations are a likely vehicle for the transmission of multi-drug resistant MRS. Resistance to erythromycin was the commonest finding (76.67% of strains), followed by tobramycin, ceftazidime (66.67%), ciprofloxacin (56.67%) and fosfomycin (53.33%). An agreement (kappa coefficient) of 0.64 was found between the two testing methods. Using the agar disc diffusion as the reference method, the sensitivity, specificity and accuracy of the miniaturized test were 98.44%, 69.44% and 83.33%, respectively. Most discrepancies between the two methods were due to isolates that were susceptible according to the disc diffusion method but resistant according to the miniaturized test (false positives). Copyright © 2017. Published by Elsevier Ltd.

  17. Observation of laser-induced elastic waves in agar skin phantoms using a high-speed camera and a laser-beam-deflection probe.

    Science.gov (United States)

    Laloš, Jernej; Gregorčič, Peter; Jezeršek, Matija

    2018-04-01

    We present an optical study of elastic wave propagation inside skin phantoms consisting of agar gel as induced by an Er:YAG (wavelength of 2.94 μm) laser pulse. A laser-beam-deflection probe is used to measure ultrasonic propagation and a high-speed camera is used to record displacements in ablation-induced elastic transients. These measurements are further analyzed with a custom developed image recognition algorithm utilizing the methods of particle image velocimetry and spline interpolation to determine point trajectories, material displacement and strain during the passing of the transients. The results indicate that the ablation-induced elastic waves propagate with a velocity of 1 m/s and amplitudes of 0.1 mm. Compared to them, the measured velocities of ultrasonic waves are much higher, within the range of 1.42-1.51 km/s, while their amplitudes are three orders of magnitude smaller. This proves that the agar gel may be used as a rudimental skin and soft tissue substitute in biomedical research, since its polymeric structure reproduces adequate soft-solid properties and its transparency for visible light makes it convenient to study with optical instruments. The results presented provide an insight into the distribution of laser-induced elastic transients in soft tissue phantoms, while the experimental approach serves as a foundation for further research of laser-induced mechanical effects deeper in the tissue.

  18. Effects of aqua agar as water replacement for posthatch chicks during transportation on residual yolk-sac and growth performance of young broiler chickens

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    Tossaporn Incharoen

    2015-12-01

    Full Text Available Water is one of the most essential nutrients for the maintenance of chicks' function, and delayed access to feed and water post hatch has been reported to dehydrate chicks. Aqua agar (AA was formulated to contain more than 95% water and an experiment was conducted to evaluate the effects of AA as water replacement for posthatch chicks during transportation. During the simulated transport, chicks were held for 24 h with (AA group or without (NO-AA group aqua agar in chick boxes. During the holding period, chicks in the AA group lost less body weight, compared with the NO-AA group. However, the weight of residual yolk tended to be lower in the AA-treated birds. There were no significant differences in the weight of gizzard, proventriculus, and liver, nor in the weights and lengths of the duodenum, jejunum and ileum. A higher body weight was also observed in the AA group at 7 days of age. At 21 days of age, weight gain and feed intake were higher (P < 0.05 in the AA group, when compared to that of the NO-AA group. No significant differences were observed in the feed conversion rate (FCR between the two groups. In conclusion, the data suggests that the use of AA as a water replacement could reduce the negative impact of water deficiency in posthatch period during transportation, resulting in greatly improved growth performance of young broilers at 21 days of age.

  19. Phosphate-Catalyzed Hydrogen Peroxide Formation from Agar, Gellan, and κ-Carrageenan and Recovery of Microbial Cultivability via Catalase and Pyruvate.

    Science.gov (United States)

    Kawasaki, Kosei; Kamagata, Yoichi

    2017-11-01

    Previously, we reported that when agar is autoclaved with phosphate buffer, hydrogen peroxide (H 2 O 2 ) is formed in the resulting medium (PT medium), and the colony count on the medium inoculated with environmental samples becomes much lower than that on a medium in which agar and phosphate are autoclaved separately (PS medium) (T. Tanaka et al., Appl Environ Microbiol 80:7659-7666, 2014, https://doi.org/10.1128/AEM.02741-14). However, the physicochemical mechanisms underlying this observation remain largely unknown. Here, we determined the factors affecting H 2 O 2 formation in agar. The H 2 O 2 formation was pH dependent: H 2 O 2 was formed at high concentrations in an alkaline or neutral phosphate buffer but not in an acidic buffer. Ammonium ions enhanced H 2 O 2 formation, implying the involvement of the Maillard reaction catalyzed by phosphate. We found that other gelling agents (e.g., gellan and κ-carrageenan) also produced H 2 O 2 after being autoclaved with phosphate. We then examined the cultivability of microorganisms from a fresh-water sample to test whether catalase and pyruvate, known as H 2 O 2 scavengers, are effective in yielding high colony counts. The colony count on PT medium was only 5.7% of that on PS medium. Catalase treatment effectively restored the colony count of PT medium (to 106% of that on PS medium). In contrast, pyruvate was not as effective as catalase: the colony count on sodium pyruvate-supplemented PT medium was 58% of that on PS medium. Given that both catalase and pyruvate can remove H 2 O 2 from PT medium, these observations indicate that although H 2 O 2 is the main cause of reduced colony count on PT medium, other unknown growth-inhibiting substances that cannot be removed by pyruvate (but can be by catalase) may also be involved. IMPORTANCE The majority of bacteria in natural environments are recalcitrant to laboratory culture techniques. Previously, we demonstrated that one reason for this is the formation of high H 2 O

  20. El medio de Kaminski adicionado con nistatina para el aislamiento de dermatofitos y otros hongos patógenos Modified Kaminski agar for the isolation of dermatophytes and some other pathogenic fungi

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    Fernando Montoya

    1989-01-01

    Full Text Available

    Se evaluaron 3 medios de cultivo de composición diferente (Mycobiotic agar, agar de Kaminski y agar de Kaminski adicionado con nistatina para el aislamiento de dermatofitos y el reaislamiento de S. schenckii y hongos negros, agentes de cromomicosis. Con el objeto de puntualizar diferencias entre dichos medios se determinaron, para cada uno, la frecuencia de aislamiento de los hongos, sus características morfológicas y su tiempo de crecimiento, así como la rapidez e Intensidad de la contaminación bacteriana y/o micótica. Se estudiaron 150 muestras de pacientes con sospecha clínica de dermatofitosis y se hicieron 30 reaislamientos de S. schenckiiy 10 de agentes de cromomicosis. Se demostró la utilidad del agar de Kaminski modificado, tanto para el aislamiento como para el reaislamiento de los agentes señalados, a pesar de su mayor índice de contaminación microbiana. Fue, además, útil para el aislamiento de levaduras del género Candida.

    Three culture media with different composition (Mycobiotic agar, Kaminski agarand Kaminski agar modified with nystatin were evaluated for isolation of dermatophytes and reisolation of S. schenckiiand dematiaceous fungi. One hundred and fifty specimens of cases suspicious of dermatophytosis, as well as 30 strains of S. schenckiiand 10 of chromoblatomycosis agents were studied. The modified Kaminski agar was efficient for the isolation and reisolation of the tested agents, in spite of Its greater contamination rate; It was equally adequate for isolation of Candida species.

  1. Incubation of premise plumbing water samples on Buffered Charcoal Yeast Extract agar at elevated temperature and pH selects for Legionella pneumophila.

    Science.gov (United States)

    Veenendaal, Harm R; Brouwer-Hanzens, Anke J; van der Kooij, Dick

    2017-10-15

    Worldwide, over 90% of the notified cases of Legionnaires' disease are caused by Legionella pneumophila. However, the standard culture medium for the detection of Legionella in environmental water samples, Buffered Charcoal Yeast Extract (BCYE) agar of pH 6.9 ± 0.4 with or without antimicrobial agents incubated at 36 ± 1 °C, supports the growth of a large diversity of Legionella species. BCYE agar of elevated pH or/and incubation at elevated temperature gave strongly reduced recoveries of most of 26 L. non-pneumophila spp. tested, but not of L. pneumophila. BCYE agar of pH 7.3 ± 0.1, incubated at 40 ± 0.5 °C (BCYE pH 7.3/40 °C) was tested for selective enumeration of L. pneumophila. Of the L. non-pneumophila spp. tested, only L. adelaidensis and L. londiniensis multiplied under these conditions. The colony counts on BCYE pH 7.3/40 °C of a L. pneumophila serogroup 1 strain cultured in tap water did not differ significantly from those on BCYE pH 6.9/36 °C when directly plated and after membrane filtration and showed repeatability's of 13-14%. By using membrane filtration L. pneumophila was detected in 58 (54%) of 107 Legionella-positive water samples from premise plumbing systems under one or both of these culture conditions. The L. pneumophila colony counts (log-transformed) on BCYE pH 7.3/40 °C were strongly related (r 2  = 0.87) to those on BCYE pH 6.9/36 °C, but differed significantly (p < 0.05) by a mean of - 0.12 ± 0.30 logs. L. non-pneumophila spp. were detected only on BCYE pH 6.9/36 °C in 49 (46%) of the samples. Hence, BCYE pH 7.3/40 °C can facilitate the enumeration of L. pneumophila and their isolation from premise plumbing systems with culturable L. non-pneumophila spp., some of which, e.g. L. anisa, can be present in high numbers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Antimicrobial Activity of Ephedra pachyclada Methanol Extract on Some Enteric Gram Negative Bacteria Which Causes Nosocomial Infections by Agar Dilution Method

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    Amin Sadeghi Dosari

    2016-10-01

    Full Text Available Background Past history indicates that plants were served as an important source of medicine. Otherwise, in developing countries people use medicinal plants against infectious disease because they cannot afford expensive drugs. Due to increasing rate of drug-resistant diseases, there is an urgent need to detect novel antimicrobial compounds from medicinal plants. Objectives The aim of the present study was to determine Antimicrobial activity of Ephedra pachyclada methanol extract on some enteric Gram-negative bacteria which causes nosocomial infections by agar dilution method. Methods In this cross-sectional study, in order to examine the antimicrobial effects of Ephedra pachyclada extract on intestinal Gram-negative bacteria, we exposed them to 0/128, 0/25, 0/5, 1, 2, 4 and 8 mg/mL of the extract. Ephedra pachyclada was collected from Jiroft Heights and methanolic extract was prepared with maceration method, during which, 50 gr powder of Ephedra pachyclada was dissolved in 300 mL of 80% methanol. Results In this study, the antibacterial effects of Ephedra pachyclada extract on Gram-negative bacteria such as Pseudomonas aeruginosa, Escherichia coli (PTCC-O157, Escherichia coli (ATCC-25922, Klebsiella pnemoniae, Serratia marcescens was investigated, defining the minimum inhibitory concentration (MIC by agar dilution method. It has been demonstrated that methanolic extract of Ephedra pachyclada affect intestinal Gram-negative bacteria. Conclusions The result showed that, Ephedra pachyclada extract has effective antimicrobial ingredients which are cheap and readily available. It can be used for medicinal purposes in the production of antimicrobial drug.

  3. Melatonin Protects Human Cells from Clustered DNA Damages, Killing and Acquisition of Soft Agar Growth Induced by X-rays or 970 MeV/n Fe ions

    Energy Technology Data Exchange (ETDEWEB)

    Das, B.; Sutherland, B.; Bennett, P. V.; Cutter, N. C.; Sutherland, J. C.

    2011-06-01

    We tested the ability of melatonin (N-acetyl-5 methoxytryptamine), a highly effective radical scavenger and human hormone, to protect DNA in solution and in human cells against induction of complex DNA clusters and biological damage induced by low or high linear energy transfer radiation (100 kVp X-rays, 970 MeV/nucleon Fe ions). Plasmid DNA in solution was treated with increasing concentrations of melatonin (0.0-3.5 mM) and were irradiated with X-rays. Human cells (28SC monocytes) were also irradiated with X-rays and Fe ions with and without 2 mM melatonin. Agarose plugs containing genomic DNA were subjected to Contour Clamped Homogeneous Electrophoretic Field (CHEF) followed by imaging and clustered DNA damages were measured by using Number Average length analysis. Transformation experiments on human primary fibroblast cells using soft agar colony assay were carried out which were irradiated with Fe ions with or without 2 mM melatonin. In plasmid DNA in solution, melatonin reduced the induction of single- and double-strand breaks. Pretreatment of human 28SC cells for 24 h before irradiation with 2 mM melatonin reduced the level of X-ray induced double-strand breaks by {approx}50%, of abasic clustered damages about 40%, and of Fe ion-induced double-strand breaks (41% reduction) and abasic clusters (34% reduction). It decreased transformation to soft agar growth of human primary cells by a factor of 10, but reduced killing by Fe ions only by 20-40%. Melatonin's effective reduction of radiation-induced critical DNA damages, cell killing, and striking decrease of transformation suggest that it is an excellent candidate as a countermeasure against radiation exposure, including radiation exposure to astronaut crews in space travel.

  4. [Evaluation of in vitro antimicrobial activity of cefazolin alone and in combination with cefmetazole or flomoxef using agar dilution method and disk diffusion method].

    Science.gov (United States)

    Matsuo, K; Uete, T

    1992-10-01

    Antimicrobial activities of cefazolin (CEZ) against 251 strains of various clinical isolates obtained during 1989 and 1990 were determined using the Mueller-Hinton agar dilution method at an inoculum level 10(6) CFU/ml. The reliability of the disk susceptility test was also studied using Mueller-Hinton agar and various disks at inoculum levels of 10(3-4) CFU/cm2 in estimating approximate values of MICs. In addition, antimicrobial activities of CEZ and cefmetazole (CMZ) or flomoxef (FMOX) in combination were investigated against methicillin-sensitive and -resistant Staphylococcus aureus (MSSA and MRSA) using the checkerboard agar dilution MIC method and the disk diffusion test either with the disks contained CEZ, CMZ, and FMOX alone, or CEZ, and CMZ or FMOX in combination. In this study, the MICs of CEZ against S. aureus were distributed with the 3 peak values at 0.39 microgram/ml, 3.13 micrograms/ml and > 100 micrograms/ml. MICs against MSSA were 0.39 microgram/ml to 0.78 microgram/ml, whereas those against MRSA were greater than 0.78 microgram/ml. MICs against majority of strains of Enterococcus faecalis were 25 micrograms/ml. Over 90% of strains of Escherichia coli and Klebsiella pneumoniae were inhibited at the level of 3.13 micrograms/ml. About 60% of isolates of indole negative Proteus spp. were inhibited at the levels of less than 3.13 micrograms/ml and 100% at 6.25 micrograms/ml, but MICs against indole positive Proteus spp., Serratia spp. and Pseudomonas aeruginosa were over 100 micrograms/ml. The antimicrobial activities of CEZ against these clinical isolates were not significantly different compared to those reported about 15-20 years ago, except for S. aureus. Highly resistant strains of S. aureus to CEZ were more prevalent in this study. The inhibitory zones obtained with the disk test were compared with MICs. The results of CEZ disk susceptibility test with 30 micrograms disk (Showa) or 10 micrograms disk (prepared in this laboratory) were well

  5. Effect of Antioxidant Mixtures on Growth and Ochratoxin A Production of Aspergillus Section Nigri Species under Different Water Activity Conditions on Peanut Meal Extract Agar

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    Carla Barberis

    2010-06-01

    Full Text Available The effect of mixtures of antioxidants butylated hydroxyanisol (BHA and propyl paraben (PP on lag phase, growth rate and ochratoxin A (OTA production by four Aspergillus section Nigri strains was evaluated on peanut meal extract agar (PMEA under different water activities (aw. The antioxidant mixtures used were: BHA + PP (mM, M1 (0.5 + 0.5, M2 (1.0 + 0.5, M3 (2.5 + 0.5, M4 (0.5 + 1.0, M5 (1.0 + 1.0, M6 (2.5 + 1.0, M7 (5.0 + 2.5 and M8 (10 + 2.5. The mixture M8 completely suppressed mycelial growth for all strains. A significant stimulation in OTA production was observed with mixtures M1 to M5 mainly at the highest aw; whereas M6, M7 and M8 completely inhibited OTA production in all strains assayed; except M6 in A. carbonarius strain (RCP G. These results could enable a future intervention strategy to minimize OTA contamination.

  6. A comparison of two agar gel immunodiffusion methods and a complement fixation test for serologic diagnosis of Brucella ovis infection in experimentally infected rams

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    M.N. Xavier

    2011-08-01

    Full Text Available A infecção por Brucella ovis é considerada uma das principais causas de epididimite e infertilidade em carneiros, resultando em falhas reprodutivas e perdas econômicas significativas em rebanhos ovinos ao redor do mundo. O estudo teve o objetivo de avaliar três testes sorológicos disponíveis para o diagnóstico da brucelose ovina por B. ovis, utilizando 181 soros ovinos. Amostras de soro provenientes de carneiros experimentalmente infectados foram coletadas ao longo de 192 dias pós-infecção (n=117 e durante o período pré-infecção (n=9. Adicionalmente, amostras de soro foram obtidas de ovinos provenientes de um rebanho livre para B. ovis (n=55. As técnicas de imunodifusão em gel de agar (IDGA, utilizando dois antígenos disponíveis comercialmente, e de fixação de complemento foram comparadas (FC. Foram obtidos resultados de sensibilidade especificidade semelhantes para ambos os métodos de IDGA e ainda, a técnica de IDGA foi mais eficiente do que a da FC para o diagnóstico sorológico da infecção por B. ovis.

  7. [Comparison between conventional methods, ChromAgar Candida® and PCR method for the identification of Candida species in clinical isolates].

    Science.gov (United States)

    Estrada-Barraza, Deyanira; Dávalos Martínez, Arturo; Flores-Padilla, Luis; Mendoza-De Elias, Roberto; Sánchez-Vargas, Luis Octavio

    2011-01-01

    The increase in the incidence of yeast species causing fungemia in susceptible immunocompromised patients in the last two decades and the low sensitivity of conventional blood culture has led to the need to develop alternative approaches for the early detection and identification of causative species. The aim of this study was to compare the usefulness of molecular testing by the polymerase chain reaction (PCR) and conventional methods to identify clinical isolates of different species, using the ID32C ATB system (bioMérieux, France), chromogenic culture Chromagar Candida® (CHROMagar, France) and morphogenesis in corn meal agar. We studied 79 isolates, in which the most prevalent species using the system ID32C and PCR was C. albicans, followed by C. tropicalis, C. glabrata and C .krusei. PCR patterns obtained for the identification of clinical isolates were stable and consistent in the various independent studies and showed good reproducibility, concluding that PCR with species-specific primers that amplify genes ITS1 and ITS2 for rRNA or topoisomerase II primers is a very specific and sensitive method for the identification of C. glabrata, C. krusei, C. albicans, and with less specificity for C. tropicalis. Copyright © 2010 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  8. Optimization of pectinase immobilization on grafted alginate-agar gel beads by 24 full factorial CCD and thermodynamic profiling for evaluating of operational covalent immobilization.

    Science.gov (United States)

    Abdel Wahab, Walaa A; Karam, Eman A; Hassan, Mohamed E; Kansoh, Amany L; Esawy, Mona A; Awad, Ghada E A

    2018-07-01

    Pectinase produced by a honey derived from the fungus Aspergillus awamori KX943614 was covalently immobilized onto gel beads made of alginate and agar. Polyethyleneimine, glutaraldehyde, loading time and enzyme's units were optimized by 2 4 full factorial central composite design (CCD). The immobilization process increased the optimal working pH for the free pectinase from 5 to a broader range of pH4.5-5.5 and the optimum operational temperature from 55°C to a higher temperature, of 60°C, which is favored to reduce the enzyme's microbial contamination. The thermodynamics studies showed a thermal stability enhancement against high temperature for the immobilized formula. Moreover, an increase in half-lives and D-values was achieved. The thermodynamic studies proved that immobilization of pectinase made a remarkable increase in enthalpy and free energy because of enzyme stability enhancement. The reusability test revealed that 60% of pectinase's original activity was retained after 8 successive cycles. This gel formula may be convenient for immobilization of other industrial enzymes. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Short communication: The effect of changing temperature and agar concentration at proliferation stage in the final success of Aleppo pine somatic embryogenesis

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    Catia Pereira

    2018-01-01

    Full Text Available Aim of the study: The effect of physical and chemical conditions at proliferation stage was evaluated in order to elucidate if this stage is the determinant phase to induce a marked effect in Pinus halepensis somatic embryogenesis. Area of study: The study was conducted in research laboratories of Neiker (Arkaute, Spain. Material and methods: Pinus halepensis embryonal masses from ten embryogenic cell lines subjected to nine treatments (tissues cultured at three temperatures on media supplemented with three agar concentrations at proliferation stage. Main results: Significant differences were observed among different proliferation conditions months later at the end of maturation, germination and acclimatization stages. Research highlights: Aleppo pine embryonal masses are cultured under standard conditions on a culture medium supplemented with 4.5 g/L Gelrite® at 23ºC. However, better results in terms of plantlet production can be obtained proliferating the embryonal masses at 18ºC in a culture media with significantly lower water availability.

  10. Comparison of E.test and Disk Diffusion Agar in Detection of Antibiotic Susceptibility of E.coli Isolated from Patients with Urinary Tract Infection in Tehran Shariati Hospital

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    Y. Erfani

    2008-07-01

    Full Text Available Introduction & Objective: UTI is one of the most common bacterial infections and Ecoli is known as an important cause of UTIs. Since bacterial resistances of antibiotics are increasing, reliable methods of antimicrobial resistance detection are of paramount importance in treatment and management of UTIs. The objective of the present study is to compare and to evaluate the performance of disk diffusion agar (Iranian and Italian and E.test (Epsilometer test (Sweden for antimicrobial susceptibility testing of Ecoli isolated from UTI.Materials & Methods: This study was done on 250 Isolates of Ecoli from patients with UTI in Shariati Hospital, Tehran University of Medical Sciences during 2004. Antibiotic susceptibility testing was performed by disk diffusion method using Iranian and Italian disk for Trimetoprim sulfamethoxazole, Gentamysin, Ceftazidim, Nitrofurantoin and Ciprofluxacin and Minimum Inhibitory concentration (MIC determination was performed by E.test for the same set of antimicrobial. All tests were performed on muller hinton agar. Results: Comparison of E.test and Iranian disk diffusion agar showed that paramount differences in antibiotic agreement (Max 37.8 % those differences in case of Ceftazidim and Gentamysin were respectively 76.8% and 62.2% whereas comparison of E.test and Italian disk diffusion agar showed less difference of antibiotics agreement (Max 11.2%.Conclusion: The results of this study showed that Iranian disk diffusion agar may be used as a preliminary screen for antibiotic susceptibility testing of E.coli and is less sensitive than Italian disk diffusion and E.test. Comparison of 3 mentioned methods have showed that E.test is the most sensitive and shows the effective dose of antibiotic for treatment and prevention of antibiotic resistance.

  11. Equivalence of Colilert-18 and lactose agar TTC Tergitol (ISO 9308-1:2000) by Spanish Water Directive 98/83/CE; Equivalencia entre el Colilert-18 y el agar lactosa Tergitol TTC (ISO 9308) segun la Directiva de Caliad de Aguas 98/83/CE

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Using lactose TTc agar with Tergitol (ISO 9308-1:2000) is the method laid down by the European Union for determining coliform bacteria and Escherichia Coli , although it also allows the use of other methods of recognised reliability, for example Colilert-18 of IDEXX Laboratories. This article reports on a comparative study carried out by eleven laboratories to determine the equivalence between the above method and the alternative Colilerti-18 method. The results obtained provide higher values than the ISO benchmark meted (18 versus 72h). This is attributed essentially to the greater sensitivity of the most probable number (MPN) method in regard to liquid media compare to the membrane filter method. Recently, this method has been approved in Spain. (Author)

  12. Influence of the environmental factors on the intensity of the oxygen, ammonium, and phosphate metabolism in the agar-containing seaweed Ahnfeltia tobuchiensis (Ahnfeltiales, Rhodophyta)

    Science.gov (United States)

    Cherbadgy, I. I.; Sabitova, L. I.

    2011-02-01

    A complex study of the influence of various environmental factors on the rate of the oxygen (MO 2), ammonium (MNH 4), and phosphate (MPO 4) metabolism in Ahnfeltia tobuchiensis has been carried out in situ in the Izmena Bay of Kunashir Island. The following environmental factors have been included into the investigation: the photosynthetically active radiation (PAR); the ammonium (NH4); the phosphate (PO4); and the tissue content of carbon (C), nitrogen (N), phosphorus (P), and chlorophyll a (Chl). The population of agar-containing seaweed A. tobuchiensis forms a layer with a thickness up to 0.5 m, which occupies about 23.3 km2; the population's biomass is equal to 125000 tons. The quantitative assessment of the organic matter production and nutrient consumption during the oxygen metabolism (MO 2) has been carried out for the whole population. It has been shown that the daily rate depends on the PAR intensity, the seawater concentrations of PO4 and NH4, and the tissue content of N and P ( r 2 = 0.78, p < 0.001). The daily NH4 consumption averages 0.21 μmol/(gDW h) and depends on the NH4 and O2 concentrations in the seawater and on the C and Chl a content in the algal tissues ( r 2 = 0.64, p < 0.001). The daily PO4 consumption averages 0.01 μmol/(gDW h) and depends on the NH4 concentration in the seawater and on the P content in the algal tissues ( r 2 = 0.40, p < 0.001).

  13. Identification of non-Listeria spp. bacterial isolates yielding a β-D-glucosidase-positive phenotype on Agar Listeria according to Ottaviani and Agosti (ALOA).

    Science.gov (United States)

    Angelidis, Apostolos S; Kalamaki, Mary S; Georgiadou, Sofia S

    2015-01-16

    Agar Listeria according to Ottaviani and Agosti (ALOA) is the mandatory medium used for the detection and enumeration of Listeria monocytogenes in foods according to the official International Organization for Standardization (ISO) methods. On ALOA, Listeria spp. appear as bluish-green colonies due to the production of β-D-glucosidase, an enzyme that cleaves 5-bromo-4-chloro-3-indolyl-β-D-glucopyranoside, a chromogenic substrate included in the formulation of the medium. The present work reports on bacterial isolates (n=64) from ready-to-eat soft cheeses, which are able to grow on ALOA, forming bluish-green colonies and therefore phenotypically resemble Listeria spp. All isolates were also capable of growing on the selective media PALCAM and RAPID L'mono. The isolates were characterised with biochemical tests including those specified in the ISO standards for the confirmation of Listeria spp. and identified via partial sequencing of their 16S rRNA gene. According to sequencing results the isolates represented 12 different bacterial species or species-groups belonging to seven different genera: Bacillus spp. (B. circulans, B. clausii, B. licheniformis and B. oleronius), Cellulosimicrobium spp. (C. funkei), Enterococcus spp. (E. faecalis, E. faecium/durans), Kocuria spp. (K. kristinae), Marinilactibacillus spp. (M. psychrotolerans), Rothia spp. (R. terrae) and Staphylococcus spp. (S. sciuri and S. saprophyticus subsp. saprophyticus/xylosus). Cellulosimicrobium spp. have never been previously isolated from foods. These results significantly extend the list of bacteria previously known as capable of growing on ALOA as bluish-green colonies and suggest that there may be room for further improvement in the medium's inhibitory properties towards non-Listeria spp., Gram-positive bacteria present in foods. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Approaches for enhancing in situ detection of enterocin genes in thermized milk, and selective isolation of enterocin-producing Enterococcus faecium from Baird-Parker agar.

    Science.gov (United States)

    Vandera, Elpiniki; Tsirka, Georgia; Kakouri, Athanasia; Koukkou, Anna-Irini; Samelis, John

    2018-05-21

    Enterococci are naturally selected for growth in thermized ewes'/goats' milk mixtures used for traditional cooked hard cheese processing in Greece. A culture-independent PCR-based approach was applied to detect the presence of enterocin-encoding genes in naturally culture-enriched thermized milk (TM). Portions of TM (63 °C, 30 s) collected from a commercial cheese plant before addition of starters were fermented at 37 °C for 48 h to facilitate growth of indigenous enterococci. The multiple enterocin-producing (m-Ent+) Enterococcus faecium KE82 and the nisin A-producing Lactococcus lactis subsp. cremoris M104 served as bacteriocin-positive inocula in separate TM treatments. The PCR results revealed a constant presence of the enterocin A, B and P genes in TM fermented naturally at 37 °C. Eleven out of 42 (26.2%) lactic isolates from the enriched TM cultures without inoculation were Ent+ E. faecium assigned to three biotypes. Biotype I (4 isolates) included single entA possessors, whereas biotype II (5 isolates) and biotype III (2 isolates) were m-Ent+ variants profiling entA-entB-entP and entA-entB genes, respectively. Biotype II displayed the strongest antilisterial activity in vitro. Surprisingly, 85.7% (6/7) of the m-Ent+ E. faecium were selectively isolated from Baird-Parker agar, reflecting their natural resistance to 0.01% tellurite contained in the egg yolk supplement. No cytolysin-positive E. faecalis or other Ent+ Enterococcus spp. were isolated. In conclusion, commercially thermized Greek milk is a natural pool or 'reservoir' of antagonistic Ent+ or m-Ent+ E. faecium strains that can be easily detected and recovered by applying this PCR-based approach to naturally fermented milks or cheese products. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. A cooled water-irrigated intraesophageal balloon to prevent thermal injury during cardiac ablation: experimental study based on an agar phantom

    International Nuclear Information System (INIS)

    Lequerica, Juan L; Berjano, Enrique J; Herrero, Maria; Melecio, Lemuel; Hornero, Fernando

    2008-01-01

    A great deal of current research is directed to finding a way to minimize thermal injury in the esophagus during radiofrequency catheter ablation of the atrium. A recent clinical study employing a cooling intraesophageal balloon reported a reduction of the temperature in the esophageal lumen. However, it could not be determined whether the deeper muscular layer of the esophagus was cooled enough to prevent injury. We built a model based on an agar phantom in order to experimentally study the thermal behavior of this balloon by measuring the temperature not only on the balloon, but also at a hypothetical point between the esophageal lumen and myocardium (2 mm distant). Controlled temperature (55 0 C) ablations were conducted for 120 s. The results showed that (1) the cooling balloon provides a reduction in the final temperature reached, both on the balloon surface and at a distance of 2 mm; (2) coolant temperature has a significant effect on the temperature measured at 2 mm from the esophageal lumen (it has a less effect on the temperature measured on the balloon surface) and (3) the pre-cooling period has a significant effect on the temperature measured on the balloon surface (the effect on the temperature measured 2 mm away is small). The results were in good agreement with those obtained in a previous clinical study. The study suggests that the cooling balloon gives thermal protection to the esophagus when a minimum pre-cooling period of 2 min is programmed at a coolant temperature of 5 deg. C or less. (note)

  16. Evaluation of resistance in a selected field strain of Haemonchus contortus to ivermectin and moxidectin using the Larval Migration on Agar Test

    Directory of Open Access Journals (Sweden)

    Fernanda S. Fortes

    2013-02-01

    Full Text Available Haemonchus contortus is one of the most common and economically significant causes of disease in small ruminants worldwide, and the control programs of parasitic nematodes - including H. contortus - rely mostly on the use of anthelmintic drugs. The consequence of the use of this, as the sole sanitary strategy to avoid parasite infections, was the reduction of the efficacy of all chemotherapeutic products with a heavy selection for resistance. The widespread of anthelmintic resistance and the difficulty of its early diagnosis has been a major concern for the sustainable parasite management on farms. The objective of this research was to determine and compare the ivermectin (IVM and moxidectin (MOX effect in a selected field strain of H. contortus with a known resistance status, using the in vitro larval migration on agar test (LMAT. Third stage larvae of the selected isolate were obtained from faecal cultures of experimentally infected sheep and incubated in eleven increasing diluted concentrations of IVM and MOX (6, 12, 24, 48, 96, 192, 384, 768, 1536, 3072 and 6144µg/mL. The dose-response sigmoidal curves were obtained using the R² value of >0.90 and the lethal concentration (LC50 dose for the tested anthelmintic drugs using a four-parameter logistic model. The LC50 value for MOX was significantly lower than IVM (1.253µg/mL and 91.06µg/mL, identifying the H. contortus isolate as considerably less susceptible to IVM compared to MOX. Furthermore, the LMAT showed a high consistency (p<0.0001 and provided to be a useful diagnostic tool for monitoring the resistance status of IVM and MOX in H. contortus field isolate, as well as it may be used for official routine drug monitoring programs under the Ministry of Agriculture (MAPA guidance.

  17. Scale-up and large-scale production of Tetraselmis sp. CTP4 (Chlorophyta) for CO2 mitigation: from an agar plate to 100-m3 industrial photobioreactors.

    Science.gov (United States)

    Pereira, Hugo; Páramo, Jaime; Silva, Joana; Marques, Ana; Barros, Ana; Maurício, Dinis; Santos, Tamára; Schulze, Peter; Barros, Raúl; Gouveia, Luísa; Barreira, Luísa; Varela, João

    2018-03-23

    Industrial production of novel microalgal isolates is key to improving the current portfolio of available strains that are able to grow in large-scale production systems for different biotechnological applications, including carbon mitigation. In this context, Tetraselmis sp. CTP4 was successfully scaled up from an agar plate to 35- and 100-m 3 industrial scale tubular photobioreactors (PBR). Growth was performed semi-continuously for 60 days in the autumn-winter season (17 th October - 14 th December). Optimisation of tubular PBR operations showed that improved productivities were obtained at a culture velocity of 0.65-1.35 m s -1 and a pH set-point for CO 2 injection of 8.0. Highest volumetric (0.08 ± 0.01 g L -1 d -1 ) and areal (20.3 ± 3.2 g m -2 d -1 ) biomass productivities were attained in the 100-m 3 PBR compared to those of the 35-m 3 PBR (0.05 ± 0.02 g L -1 d -1 and 13.5 ± 4.3 g m -2 d -1 , respectively). Lipid contents were similar in both PBRs (9-10% of ash free dry weight). CO 2 sequestration was followed in the 100-m 3 PBR, revealing a mean CO 2 mitigation efficiency of 65% and a biomass to carbon ratio of 1.80. Tetraselmis sp. CTP4 is thus a robust candidate for industrial-scale production with promising biomass productivities and photosynthetic efficiencies up to 3.5% of total solar irradiance.

  18. Proposal for agar disk diffusion interpretive criteria for susceptibility testing of bovine mastitis pathogens using cefoperazone 30μg disks.

    Science.gov (United States)

    Feßler, Andrea T; Kaspar, Heike; Lindeman, Cynthia J; Peters, Thomas; Watts, Jeffrey L; Schwarz, Stefan

    2017-02-01

    Cefoperazone is a third generation cephalosporin which is commonly used for bovine mastitis therapy. Bacterial pathogens involved in bovine mastitis are frequently tested for their susceptibility to cefoperazone. So far, the cefoperazone susceptibility testing using 30μg disks has been hampered by the lack of quality control (QC) ranges as well as the lack of interpretive criteria. In 2014, QC ranges for 30 μg cefoperazone disks have been established for Staphylococcus aureus ATCC ® 25923 and Escherichia coli ATCC ® 25922. As a next step, interpretive criteria for the susceptibility testing of bovine mastitis pathogens should be developed. For this, 637 bovine mastitis pathogens (including 112 S. aureus, 121 coagulase-negative staphylococci (CoNS), 103 E. coli, 101 Streptococcus agalactiae, 100 Streptococcus dysgalactiae and 100 Streptococcus uberis) were investigated by agar disk diffusion according to the document Vet01-A4 of the Clinical and Laboratory Standards Institute (CLSI) using 30μg cefoperazone disks and the results were compared to the corresponding MIC values as determined by broth microdilution also according to the aforementioned CLSI document. Based on the results obtained and taking into account the achievable milk concentration of cefoperazone after regular dosing, the following interpretive criteria were proposed as a guidance for mastitis diagnostic laboratories: for staphylococci and E. coli ≥23mm (susceptible), 18-22mm (intermediate) and ≤17mm (resistant) and for streptococci ≥18mm (susceptible), and ≤17mm (non-susceptible). These proposed interpretive criteria shall contribute to a harmonization of cefoperazone susceptibility testing of bovine mastitis pathogens. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Grain growth behavior of Li{sub 4}SiO{sub 4} pebbles fabricated by agar method for tritium breeder

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Maoqiao [School of Materials Science and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083 (China); Zhang, Yingchun, E-mail: zycustb@126.com [School of Materials Science and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083 (China); Zhang, Yun; Wang, Chaofu; Liu, Wei [School of Materials Science and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083 (China); Yu, Yonghong [Department of Physics, Renmin University of China, Beijing, 100872 (China)

    2016-11-15

    Highlights: • Grain sizes of Li{sub 4}SiO{sub 4} were adjusted by different silicon sources. • Grain growth exponent of Li{sub 4}SiO{sub 4} was about 3. • Grain growth activation energy of Li{sub 4}SiO{sub 4} was about 125.54 kJ/mol. • Grain growth of Li{sub 4}SiO{sub 4} pebble was controlled by vapor transport. - Abstract: The Li{sub 4}SiO{sub 4} tritium breeding pebbles will be filled in the blanket and used for 2 years or more at high temperatures, which would increase the grain size and affect tritium release. Hence, grain sizes of the Li{sub 4}SiO{sub 4} pebbles fabricated by agar method were investigated, and two kinds of different silicon sources (crystal and amorphous SiO{sub 2}) with different particle sizes were used. The particle size of SiO{sub 2} could affect grain size and density of the Li{sub 4}SiO{sub 4} pebble. And the isothermal sintering was carried out to study the grain growth kinetics of Li{sub 4}SiO{sub 4}. The grain growth exponent (n) and the activation energy (Q) were calculated by the phenomenological kinetic equation. The calculated n values were 4.10, 3.98, 3.34 and 2.96, and corresponding Q values were 152.15, 147.99, 125.54 and 110.58 kJ/mol, respectively. At the higher sintering temperatures (950 and 1000 °C), the grain growth of Li{sub 4}SiO{sub 4} was controlled by vapor transport.

  20. Cultivation characteristics and gene expression profiles of Aspergillus oryzae by membrane-surface liquid culture, shaking-flask culture, and agar-plate culture.

    Science.gov (United States)

    Imanaka, Hiroyuki; Tanaka, Soukichi; Feng, Bin; Imamura, Koreyoshi; Nakanishi, Kazuhiro

    2010-03-01

    We cultivated a filamentous fungus, Aspergillus oryzae IAM 2706 by three different cultivation methods, i.e., shaking-flask culture (SFC), agar-plate culture (APC), and membrane-surface liquid culture (MSLC), to elucidate the differences of its behaviors by different cultivation methods under the same media, by measuring the growth, secretion of proteases and alpha-amylase, secreted protein level, and gene transcriptional profile by the DNA microarray analysis. The protease activities detected by MSLC and APC were much higher than that by SFC, using both modified Czapek-Dox (mCD) and dextrin-peptone-yeast extract (DPY) media. The alpha-amylase activity was detected in MSLC and APC in a much larger extent than that in SFC when DPY medium was used. On the basis of SDS-PAGE analyses and N-terminal amino acid sequences, 6 proteins were identified in the supernatants of the culture broths using DPY medium, among which oryzin (alkaline protease) and alpha-amylase were detected at a much higher extent for APC and MSLC than those for SFC while only oryzin was detected in mCD medium, in accordance with the activity measurements. A microarray analysis for the fungi cultivated by SFC, APC, and MSLC using mCD medium was carried out to elucidate the differences in the gene transcriptional profile by the cultivation methods. The gene transcriptional profile obtained for the MSLC sample showed a similar tendency to the APC sample while it was quite different from that for the SFC sample. Most of the genes specifically transcribed in the MSLC sample versus those in the SFC sample with a 10-fold up-regulation or higher were unknown or predicted proteins. However, transcription of oryzin gene was only slightly up-regulated in the MSLC sample and that of alpha-amylase gene, slightly down-regulated. Copyright 2009 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

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

    DEFF Research Database (Denmark)

    Hegstad, Kristin; Giske, Christian G; Haldorsen, Bjørg

    2014-01-01

    faecium (n=18) strains with and without nonsusceptibility to vancomycin was examined blindly in Danish (n=5), Norwegian (n=13), and Swedish (n=10) laboratories using the EUCAST disk diffusion method (n=28) and the CLSI agar screen (n=18) or the Vitek 2 system (bioMérieux) (n=5). The EUCAST disk diffusion...... method (very major error [VME] rate, 7.0%; sensitivity, 0.93; major error [ME] rate, 2.4%; specificity, 0.98) and CLSI agar screen (VME rate, 6.6%; sensitivity, 0.93; ME rate, 5.6%; specificity, 0.94) performed significantly better (P=0.02) than the Vitek 2 system (VME rate, 13%; sensitivity, 0.87; ME...... rate, 0%; specificity, 1). The performance of the EUCAST disk diffusion method was challenged by differences in vancomycin inhibition zone sizes as well as the experience of the personnel in interpreting fuzzy zone edges as an indication of vancomycin resistance. Laboratories using Oxoid agar (P

  2. Antimicrobial Susceptibility of Flavobacterium psychrophilum from Chilean Salmon Farms and Their Epidemiological Cut-Off Values Using Agar Dilution and Disk Diffusion Methods.

    Science.gov (United States)

    Miranda, Claudio D; Smith, Peter; Rojas, Rodrigo; Contreras-Lynch, Sergio; Vega, J M Alonso

    2016-01-01

    Flavobacterium psychrophilum is the most important bacterial pathogen for freshwater farmed salmonids in Chile. The aims of this study were to determine the susceptibility to antimicrobials used in fish farming of Chilean isolates and to calculate their epidemiological cut-off (CO WT ) values. A number of 125 Chilean isolates of F. psychrophilum were isolated from reared salmonids presenting clinical symptoms indicative of flavobacteriosis and their identities were confirmed by 16S rRNA polymerase chain reaction. Susceptibility to antibacterials was tested on diluted Mueller-Hinton by using an agar dilution MIC method and a disk diffusion method. The CO WT values calculated by Normalized Resistance Interpretation (NRI) analysis allow isolates to be categorized either as wild-type fully susceptible (WT) or as manifesting reduced susceptibility (NWT). When MIC data was used, NRI analysis calculated a CO WT of ≤0.125, ≤2, and ≤0.5 μg mL -1 for amoxicillin, florfenicol, and oxytetracycline, respectively. For the quinolones, the CO WT were ≤1, ≤0.5, and ≤0.125 μg mL -1 for oxolinic acid, flumequine, and enrofloxacin, respectively. The disk diffusion data sets obtained in this work were extremely diverse and were spread over a wide range. For the quinolones there was a close agreement between the frequencies of NWT isolates calculated using MIC and disk data. For oxolinic acid, flumequine, and enrofloxacin the frequencies were 45, 39, and 38% using MIC data, and 42, 41, and 44%, when disk data were used. There was less agreement with the other antimicrobials, because NWT frequencies obtained using MIC and disk data, respectively, were 24 and 10% for amoxicillin, 8 and 2% for florfenicol, and 70 and 64% for oxytetracycline. Considering that the MIC data was more precise than the disk diffusion data, MIC determination would be the preferred method for susceptibility testing for this species and the NWT frequencies derived from the MIC data sets should be

  3. Antimicrobial Susceptibility of Flavobacterium psychrophilum from Chilean Salmon Farms and their Epidemiological Cut-off Values using Agar Dilution and Disk Diffusion Methods

    Directory of Open Access Journals (Sweden)

    Claudio D Miranda

    2016-11-01

    Full Text Available Flavobacterium psychrophilum is the most important bacterial pathogen for freshwater farmed salmonids in Chile. The aims of this study were to determine the susceptibility to antimicrobials used in fish farming of Chilean isolates and to calculate their epidemiological cut-off (COWT values. A number of 125 Chilean isolates of F. psychrophilum were isolated from reared salmonids presenting clinical symptoms indicative of flavobacteriosis and their identities were confirmed by 16S rRNA polymerase chain reaction. Susceptibility to antibacterials was tested on diluted Mueller-Hinton by using an agar dilution MIC method and a disk diffusion method. The COWT values calculated by Normalised Resistance Interpretation (NRI analysis allow isolates to be categorized either as wild-type fully susceptible (WT or as manifesting reduced susceptibility (NWT. When MIC data was used, NRI analysis calculated a COWT of ≤ 0.125 μg mL-1, ≤ 2 μg mL-1 and ≤ 0.5 μg mL-1 for amoxicillin, florfenicol and oxytetracycline, respectively. For the quinolones, the COWT were ≤1 μg mL-1, ≤ 0.5 μg mL-1 and ≤ 0.125 μg mL-1 for oxolinic acid, flumequine and enrofloxacin respectively. The disc diffusion data sets obtained in this work were extremely diverse and were spread over a wide range. For the quinolones there was a close agreement between the frequencies of NWT isolates calculated using MIC and disc data. For oxolinic acid, flumequine and enrofloxacin the frequencies were 45, 39 and 38% using MIC data, and 42, 41 and 44%, when disc data were used. There was less agreement with the other antimicrobials, because NWT frequencies obtained using MIC and disc data respectively, were 24% and 10% for amoxicillin, 8% and 2% for florfenicol and 70% and 64% for oxytetracycline. Considering that the MIC data was more precise than the disc diffusion data, MIC determination would be the preferred method for susceptibility testing for this species and the NWT frequencies

  4. Antimicrobial test of Roselle (Hibiscus sabdariffa L. ethanol extract againts Porphyromonas gingivalis and Streptococcus sanguis using agar method (In vitro study

    Directory of Open Access Journals (Sweden)

    Lenni Indriani

    2016-08-01

    Full Text Available The use of natural materials in the world of health tends to increase every single year, including  in dentistry. Due to the increased of resistance to antibiotics, the development and new innovations to obtain a new antimicrobial agent. Some potential sources of plants have been studied. One of the natural plants is used as drinks, food, medicine and antimicrobial agent is Hibiscus sabdariffa Linn commonly known as Roselle. Several major Gram-negative bacteria are related to periodontal disease such as Porphyromonas gingivalis (P.gingivalis, The dominant species of Gram-positive including Streptococcus sanguis(S.sanguis. The purpose of this in vitro study is to evaluate the Roselle ethanol extract against P.gingivalis bacteria (Gram negative bacteria and S. sanguis (Gram positive bacteria with a concentration of 2.5%, 5%, 7.5% and 10%. The in vitro study of antibacterial effectiveness of Roselle (Hibiscus sabdariffa L. ethanol extract on P.gingivalis and S. sanguis. Natrium Agar (NA solution was poured into a glass plate which had previously been sterilized and then left in place until the medium solidified. P.gingivalis and S.sanguis bacterial cultures were inoculated with inscribed which had solidified. Then put paper disk which had previously been saturated with Roselle extract samples with a concentration of 2.5%, 5%, 7.5% and 10%, and the negative control at the surface of the medium (Ampicillin and incubated for 1 day. Clear zone is formed then observed and measured. There are 24 samples, consisting of 12 samples  P.gingivalis and S.sanguis 12 samples, given intervention roselle flower extract with four types of concentrations to determine the minimum inhibitory consentration (MIC. The observations show that the extensive zone of inhibition concentration of 2.5% a broad zone of inhibition is the smallest among other concentration, both of S.sanguins and P.gingivalis. Meanwhile, the average increases the

  5. Cinco años de experiencia con el agar de capa delgada para el diagnóstico rápido de tuberculosis.

    Directory of Open Access Journals (Sweden)

    Gloria Isabel Mejía

    2004-06-01

    Full Text Available La tuberculosis continúa siendo un problema de salud pública en el mundo, principalmente en los países en vía de desarrollo, donde ocurre el 95% de los casos. Estos países no tienen fácil acceso a los métodos de diagnóstico rápido actualmente disponibles, debido al alto costo que tienen. Por tanto, se hace necesario el desarrollo de técnicas rápidas de más bajo costo que sean accesibles a estas regiones. Este trabajo tuvo como objetivo comparar un medio de cultivo rápido y de bajo costo, el agar de capa delgada (CD7H11, con el medio de Lowenstein- Jensen. Para esto se procesaron 1.809 muestras clínicas de pacientes con diagnóstico presuntivo de tuberculosis y que requirieron cultivo. Las muestras se procesaron según los métodos estándar recomendados y se sembraron en ambos medios de cultivo. Se comparó la rapidez para la detección de cultivos positivos y la sensibilidad, la especificidad, los valores predictivos (VPP y VPN y la concordancia de CD7H11 con respecto al método de referencia. CD7H11 mostró una sensibilidad del 73,5% (IC95%:69,6-80,4 y una especificidad del 99,2% (IC95%: 98,8-99,6, valor predictivo positivo de 90,4% (IC95%: 85,3-95,6 y valor predictivo negativo de 97,6% (IC95%: 96,8-98,3. La concordancia entre los dos métodos fue de 0,52 (coeficiente kappa. CD7H11 tuvo un tiempo promedio para la detección de las micobacterias de 11 días (DE±4,9, frente a 26,5 (DE±8.6 días del LJ. Se obtuvieron resultados similares al comparar las muestras pulmonares y multibacilares. CD7H11 mostró una sensibilidad menor en muestras extrapulmonares, comparada con las pulmonares (65,8; IC95%: 55,1-76,5 vs. 81,0; IC95%: 72,4-89,7. El uso concomitante de los medios de cultivo aumentó la sensibilidad pues 24,1% de las muestras se detectaron sólo por LJ y 7,1% por CD7H11. El medio de capa delgada demostró ser un método rápido de cultivo para micobacterias que es fácilmente accesible a los sistemas de salud de los pa

  6. Evaluation of the Bruker Biotyper Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry System for Identification of Aspergillus Species Directly from Growth on Solid Agar Media

    Directory of Open Access Journals (Sweden)

    Ying Li

    2017-06-01

    Full Text Available We evaluated the accuracy of the Bruker Biotyper matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS system at identifying clinical isolates of Aspergillus species that were grown on agar media. A total of 381 non-duplicate Aspergillus isolates representing 21 different Aspergillus species identified by molecular analysis were included in this study. The Bruker Biotyper MALDI-TOF MS system was able to identify 30.2% (115/381 of the isolates to the species level (score values of ≥2.000 and 49.3% to the genus level (score values of 1.700–1.999. When the identification cutoff value was lowered from ≥2.000 to ≥1.700, the species-level identification rate increased to 79.5% with a slight rise of false identification from 2.6 to 5.0%. From another aspect, a correct species-level identification rate of 89% could be reached by the Bruker Biotyper MALDI-TOF MS system regardless of the score values obtained. The Bruker Biotyper MALDI-TOF MS system had a moderate performance in identification of Aspergillus directly inoculated on solid agar media. Continued expansion of the Bruker Biotyper MALDI-TOF MS database and adoption of alternative cutoff values for interpretation are required to improve the performance of the system for identifying highly diverse species of clinically encountered Aspergillus isolates.

  7. Evaluation of the Bruker Biotyper Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry System for Identification of Aspergillus Species Directly from Growth on Solid Agar Media.

    Science.gov (United States)

    Li, Ying; Wang, He; Zhao, Yu-Pei; Xu, Ying-Chun; Hsueh, Po-Ren

    2017-01-01

    We evaluated the accuracy of the Bruker Biotyper matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) system at identifying clinical isolates of Aspergillus species that were grown on agar media. A total of 381 non-duplicate Aspergillus isolates representing 21 different Aspergillus species identified by molecular analysis were included in this study. The Bruker Biotyper MALDI-TOF MS system was able to identify 30.2% (115/381) of the isolates to the species level (score values of ≥2.000) and 49.3% to the genus level (score values of 1.700-1.999). When the identification cutoff value was lowered from ≥2.000 to ≥1.700, the species-level identification rate increased to 79.5% with a slight rise of false identification from 2.6 to 5.0%. From another aspect, a correct species-level identification rate of 89% could be reached by the Bruker Biotyper MALDI-TOF MS system regardless of the score values obtained. The Bruker Biotyper MALDI-TOF MS system had a moderate performance in identification of Aspergillus directly inoculated on solid agar media. Continued expansion of the Bruker Biotyper MALDI-TOF MS database and adoption of alternative cutoff values for interpretation are required to improve the performance of the system for identifying highly diverse species of clinically encountered Aspergillus isolates.

  8. New methods for isolation of keratolytic bacteria inducing intractable hoof wall cavity (Gidoh) in a horse; double screening procedures of the horn powder agar-translucency test and horn zymography.

    Science.gov (United States)

    Kuwano, Atsutoshi; Niwa, Hidekazu; Arai, Katsuhiko

    2017-01-01

    To establish a new system to isolate keratolytic bacteria from the hoof wall cavity ( Gidoh ) of a racehorse, we invented the horn powder agar-translucency (HoPAT) test and horn zymography (HZ). Using routine bacteriological techniques and these methods, we isolated five strains of keratolytic soil bacteria, which were then identified by means of 16S ribosomal RNA (rRNA) gene sequencing analysis. The findings from the study on the horse suggested that Brevibacterium luteolum played the main role in the local fragility of the hoof, eventually forming a Gidoh in coordination with four other strains of keratolytic bacteria. The double screening procedures of the HoPAT test and HZ were useful and easy techniques for isolating the keratolytic bacteria from the horn lesions.

  9. Evaluation of risk factors in patients with vulvovaginal candidiasis and the value of chromID Candida agar versus CHROMagar Candida for recovery and presumptive identification of vaginal yeast species.

    Science.gov (United States)

    Guzel, Ahmet Bariş; Ilkit, Macit; Akar, Tuba; Burgut, Refik; Demir, S Cansun

    2011-01-01

    Vulvovaginal candidiasis (VVC), particularly the recurrent form, remains an intractable problem for clinicians, microbiologists, and patients. It is essential to confirm the clinical diagnosis by mycological methods and avoid empirical therapy. The recovery of yeast in fungal culture, such as on Sabouraud dextrose agar, remains the gold standard for diagnosis. In this investigation, we examined 474 participants, including 122 (25.7%) with acute VVC cases, 249 (52.5%) who had recurrent VVC (RVVC) cases, and 103 (21.7%) healthy controls. We also administered a questionnaire to obtain information on patient lifestyle and medical, gynecological, and sexual history. In addition, we compared the performance of chromID Candida agar (CAN2) to CHROMagar Candida (CAC) and Sabouraud dextrose agar with gentamicin and chloramphenicol (SGC2). The yeasts were identified by conventional methods including the germ tube test, microscopic morphology on cornmeal-Tween 80 agar, and the commercial API 20C AUX system. We detected yeasts in 60 of 122 (49.2%) patients with acute VVC cases, 110 of 249 (44.2%) with RVVC cases, and in 35 of 103 (34%) healthy controls (P = 0.07). A total of 205 samples were found to be positive for fungi (43.2%), of which 176 (85.9%) were monofungal, and 29 (14.1%) were polyfungal. In addition, 198 of these samples (96.6%) were positive on CAN2, 195 (95.1%) on CAC, 189 (92.2%) on SGC2, and 183 (89.3%) samples on all three (P = 0.17). The 234 yeast isolates recovered were C. albicans (n = 118), C. glabrata (n = 82), C. kefyr (n = 11), C. krusei (n = 9), C. lipolytica (n = 3), C. colliculosa (n = 2), C. parapsilosis (n = 2), C. pelliculosa (n = 2), C. tropicalis (n = 2), and other species of Candida (n = 3). Of the 29 polyfungal populations, 28 (96.6%) were detected in CAN2, 25 in (86.2%) CAC, and 25 (86.2%) on both (P = 0.35). Notably, we detected the high predominance of C. albicans+C. glabrata (86.2%) in polyfungal populations. Briefly, the detection of C

  10. Implementation of the Thin Layer Agar Method for Diagnosis of Smear-Negative Pulmonary Tuberculosis in a Setting with a High Prevalence of Human Immunodeficiency Virus Infection in Homa Bay, Kenya▿ †

    Science.gov (United States)

    Martin, Anandi; Munga Waweru, Peter; Babu Okatch, Fred; Amondi Ouma, Naureen; Bonte, Laurence; Varaine, Francis; Portaels, Françoise

    2009-01-01

    The objective of this study was to evaluate the performance of a low-cost method, the thin layer agar (TLA) method, for the diagnosis of smear-negative patients. This prospective study was performed in Homa Bay District Hospital in Kenya. Out of 1,584 smear-negative sputum samples, 212 (13.5%) were positive by culture in Löwenstein-Jensen medium (LJ) and 220 (14%) were positive by the TLA method. The sensitivities of LJ and TLA were 71% and 74%, respectively. TLA could become an affordable method for the diagnosis of smear-negative tuberculosis in resource-limited settings, with results available within 2 weeks. PMID:19494065

  11. Propagação in vitro de Oncidium baueri Lindl. (Orchidaceae sem uso de ágar = In vitro orchid propagation of Oncidium baueri (Orchidaceae without the use of agar

    Directory of Open Access Journals (Sweden)

    Ricardo Tadeu de Faria

    2006-01-01

    Full Text Available O trabalho teve como objetivo a propagação in vitro de Oncidium baueri(Orchidaceae sem uso de ágar como agente solidificante do meio de cultura. As sementes foram germinadas em meio Murashige e Skoog (MS, 1962 modificado com a metade da concentração de macronutrientes. As plântulas, ao atingirem em média 1 cm de altura, foram subcultivadas para frascos de plástico de 600 mL, contendo 200 mL do mesmo meionutritivo utilizado para a germinação. Os tratamentos avaliados foram: 7 g de ágar por litro + meio 1/2 MS líquido; espuma de poliuretano picada + meio 1/2 MS líquido; esfagno + meio 1/2 MS líquido; areia grossa + meio 1/2 MS líquido. Oito meses após o início do experimento, as variáveis analisadas foram: altura da parte aérea, comprimento da maior raiz, número de brotações, número de raízes e matéria fresca total. As análises estatísticas demonstram que os tratamentos contendo esfagno ou areia não são indicados para substituírem o ágar, porém o tratamento com espuma de poliuretano picada proporcionou um ótimo enraizamento e ótimo desenvolvimento vegetativo das plântulas, sendo, portanto, uma alternativa eficiente e de menor custo para a substituição do ágar na propagação in vitro deOncidium baueri.This research aims at studying the in vitro propagation of Oncidium baueri (Orchidaceae without the use of agar as a solidifying agent of culture medium. The seeds were germinated in Murashige and Skoog medium (MS, 1962 modified with half of the macronutrients concentrations. When the seedlings reach an average height of 1 cm, they were subcultivated in 600 mL plastic flasks containing 200 mL of the same nutritive medium used for germination. The evaluated treatments were: 7 g of agar per liter + 1/2 MS medium liquid; chopped (polyurethane foam + 1/2 MS medium liquid; sphagnum + 1/2 MSmedium liquid; thick sand + 1/2MS medium liquid. The evaluated variables after 8 months of study were: aerial part height, tallest

  12. Proof of Principle for a Real-Time Pathogen Isolation Media Diagnostic: The Use of Laser-Induced Breakdown Spectroscopy to Discriminate Bacterial Pathogens and Antimicrobial-Resistant Staphylococcus aureus Strains Grown on Blood Agar

    Directory of Open Access Journals (Sweden)

    Rosalie A. Multari

    2013-01-01

    Full Text Available Laser-Induced Breakdown Spectroscopy (LIBS is a rapid, in situ, diagnostic technique in which light emissions from a laser plasma formed on the sample are used for analysis allowing automated analysis results to be available in seconds to minutes. This speed of analysis coupled with little or no sample preparation makes LIBS an attractive detection tool. In this study, it is demonstrated that LIBS can be utilized to discriminate both the bacterial species and strains of bacterial colonies grown on blood agar. A discrimination algorithm was created based on multivariate regression analysis of spectral data. The algorithm was deployed on a simulated LIBS instrument system to demonstrate discrimination capability using 6 species. Genetically altered Staphylococcus aureus strains grown on BA, including isogenic sets that differed only by the acquisition of mutations that increase fusidic acid or vancomycin resistance, were also discriminated. The algorithm successfully identified all thirteen cultures used in this study in a time period of 2 minutes. This work provides proof of principle for a LIBS instrumentation system that could be developed for the rapid discrimination of bacterial species and strains demonstrating relatively minor genomic alterations using data collected directly from pathogen isolation media.

  13. Prevalence of Peste Des Petits Ruminants Virus (PPRV in Mardan, Hangu and Kohat District of Pakistan; Comparative Analysis of PPRV Suspected serum samples using Competitive ELISA (cELISA and Agar Gel Immunodiffusion (AGID

    Directory of Open Access Journals (Sweden)

    Misbah Aslam

    2009-06-01

    Full Text Available Peste des petits Ruminants (PPR is an acute, febrile, highly contagious and economically important viral disease of small ruminants. However PPR is more prevalent in sheep and goat. Competitive ELISA, Virus neutrilization test, and RT-PCR are the available techniques for diagnosis of PPR which give rapid detection where as Agar gel immunodiffusion and Counter immunoelectrophoresis were previously used for PPR detection. In this study two serological techniques were compared for PPR diagnosis. The main aim of this study was to evaluate the comparative sensitivity of both techniques for PPR detection. For this purpose one hundred and sixty PPR suspected serum samples collected from goats and sheep flocks (unvaccinated from three Districts of NWFP including Mardan, Hangu and Kohat were analyzed in National Veterinary Laboratories, Islamabad. Out of these 160 samples, fifty (50 were found positive for PPR antibodies with cELISA (Prevalence = 31.25%. The cELISA positive serum samples however gave negative results when tested with AGID although the control well was always positive. Thus it was concluded that cELISA technique is more sensitive and specific than AGID for PPR antibody detection. [Vet. World 2009; 2(3.000: 89-92

  14. Tuleval aastal algab agar passivahetus / Madis Filippov

    Index Scriptorium Estoniae

    Filippov, Madis

    2011-01-01

    Järgmisel aastal tuleb välja vahetada kehtivusaja lõpu tõttu üle poole miljoni passi ja ID-kaardi, järgnevatel aastatel arvud suurenevad. Kodakondsus- ja migratsiooniosakondades plaanitavad muudatused

  15. Evaluation of Brazilian medical devices using agar diffusion cytotoxicity assay Avaliação de dispositivos médicos brasileiros utilizando o ensaio de citotoxicidade pela difusão em ágar

    Directory of Open Access Journals (Sweden)

    Mirian N. P. Vidal

    2009-04-01

    Full Text Available Over the last decades, governmental actions and mechanisms created to protect consumer rights have been linked to a growing effort to guarantee the quality and reliability of products. Samples of condoms (latex, medical devices and blood bags (PVC - polyvinyl chloride have been tested using the agar diffusion assay. This assay evaluates the cytotoxicity induced by biomaterials by measuring the biological reactivity of mammalian cell cultures in contact with these materials. PVC is used in the production of medical devices because of its specific properties, such as flexibility, obtained after the addition of plasticizers (phthalates, which can cause toxicity even at low doses. Latex is a natural elastomer used for surgical gloves and condoms with a formulation that includes dispersion of liquid latex and chemicals, such as antioxidants and a vulcanizing accelerator, both of which are able to induce cytotoxicity. Samples were analyzed by the National Institute of Quality Control in Health - INCQS of the Oswaldo Cruz Foundation (Fiocruz in accordance with the governmental sanitary surveillance actions on respect to the quality control. We observed an increase in the quality of the products in relation to the results of the agar diffusion assay during the period between 2000 and 2007. This situation, together with other actions, reflects in an improvement in the quality of products that can be translated in the health of the population.Durante as últimas décadas, a disseminação de ações governamentais e os mecanismos criados para proteger os direitos dos consumidores se associaram em crescentes esforços para garantir a qualidade e confiabilidade dos produtos. As amostras de preservativos (látex, dispositivos médicos e bolsas de sangue (PVC - cloreto polivinílico foram testadas utilizando o ensaio de difusão em ágar. O teste avalia a citotoxicidade induzida por biomateriais, medindo a reatividade biológica de culturas de células de mam

  16. Fontes de nitrogênio, polpa de banana e ágar no desenvolvimento in vitro de plântulas de orquídea Nitrogen sources, banana pulp and agar in the orchid seedlings in vitro development

    Directory of Open Access Journals (Sweden)

    Moacir Pasqual

    2009-06-01

    Full Text Available Foram realizados dois experimentos com o objetivo de estudar os efeitos de fontes de nitrogênio, polpa de banana e ágar no desenvolvimento in vitro de orquídea Cattleya loddigesii. O primeiro experimento constituiu-se de NH4NO3 (0; 25; 50; 75 e 100% da formulação de 330 mg L-1 e KNO3 (0; 25; 50 e 100% da formulação de 380 mg L-1 acrescidas ao meio MS. No segundo experimento, os tratamentos consistiram de concentrações de ágar (0; 2; 4; 6 e 8 g L-1, no meio de cultura Knudson C, acrescido de polpa de banana nanica (0; 50; 100; 150 e 200 g L-1 em todas as combinações possíveis. Após a inoculação as culturas foram mantidas em sala de crescimento com irradiância em torno de 35 μmol m-2 s-1, temperatura de 25±1ºC e fotoperíodo de 16 horas, por 90 dias. Com base no peso da matéria fresca das plântulas, número de raízes, comprimento da parte aérea e comprimento da maior raiz, a adição de 17,5 a 41,16% da formulação original de NH4NO3 ao meio MS proporcionou melhor desenvolvimento in vitro em plântulas de Cattleya loddigesii. Maior número de folhas foi obtido com a adição ao meio MS de 100% da formulação original de NH4NO3 e 50% de KNO3. A multiplicação in vitro de plântulas de orquídea Cattleya loddigesii é viável em meio Knudson C líquido com a utilização de 128,42 g L-1 de polpa de banana nanica.Two experiments were carried out in order to evaluate the effects of nitrogen sources, banana pulp and agar on Cattleya loddigesii seedlings development in vitro. In the first experiment were tested NH4NO3 at 0; 25; 50; 75 and 100% (330 mg L-1 formulation and KNO3 0; 25; 50 and 100% (380 mg L-1 formulation added to MS medium. The second experiment consisted of different agar concentrations (0; 2; 4; 6 and 8 g L-1, banana nanica pulp (0; 50; 100; 150 and 200 g L-1 in all the possible combinations added to Knudson C medium. After inoculation the plantlets were maintained in growth room with irradiancy around 35

  17. Digital monitoring of mycelium growth kinetics and vigor of shiitake (Lentinula edodes (Berk. Pegler on agar medium Monitoramento digital do crescimento e vigor do shiitake (Lentinula edodes (Berk. Pegler em meio de cultura

    Directory of Open Access Journals (Sweden)

    Renato Mamede de Castro Montini

    2006-03-01

    Full Text Available The mycelium growth kinetics and vigor of shiitake (Lentinula edodes (Berk. Pegler strains LE 96/17, LE 98/51, LE 98/53, and LE 98/56 were studied under different agar medium compositions. The strains were from the mycological collection of the Módulo de Cogumelos, Faculdade de Ciências Agronômicas, Unesp-Botucatu, Brazil. Mycelium fragments from stock cultures were transferred to Petri dishes with Sawdust extract-Dextrose-Agar medium. The area of growth and vigor (density of the mycelia were daily recorded with a digital camera, during incubation, until the complete colonization of the Petri dish. The images were analyzed by the freeware UTHSCSA ImageTool, v. 2.0, developed by the University of Texas Health Science Center, San Antonio. The kinetics of mycelium growth, as measured by the mycelium area (mm², has as a deterministic component an exponential function of Gompertz. The vigor, as evaluated by mycelium color in gray scale, was similar for all strains, reached a maximal value between the 4th and 5th day of incubation and decreased further on. The velocity of growth of L. edodes strains was lower in enriched culture media, while vigor was higher. Digital monitoring permits a objective evaluation of the growth kinetics of L. edodes in vitro.Avaliou-se o crescimento e vigor das linhagens LE 96/17, LE 98/51, LE 98/53 e LE 98/56 de Lentinula edodes (Berk Pegler em diferentes composições de meio de cultura. As linhagens foram provenientes da Micoteca do Módulo de Cogumelos da Faculdade de Ciências Agronômicas, Unesp, Campus de Botucatu. Os isolados foram obtidos por propagação vegetativa, pela transferência asséptica do micélio para o meio de cultura de extrato de serragem-dextrose-ágar. O crescimento e vigor do micélio foi fotografado diariamente com uma câmera digital, durante a incubação, até a colonização total da placa de Petri. As imagens foram analisadas pelo programa UTHSCSA ImageTool (freeware, versão 2

  18. Comparing the mannitol-egg yolk-polymyxin agar plating method with the three-tube most-probable-number method for enumeration of Bacillus cereus spores in raw and high-temperature, short-time pasteurized milk.

    Science.gov (United States)

    Harper, Nigel M; Getty, Kelly J K; Schmidt, Karen A; Nutsch, Abbey L; Linton, Richard H

    2011-03-01

    The U.S. Food and Drug Administration's Bacteriological Analytical Manual recommends two enumeration methods for Bacillus cereus: (i) standard plate count method with mannitol-egg yolk-polymyxin (MYP) agar and (ii) a most-probable-number (MPN) method with tryptic soy broth (TSB) supplemented with 0.1% polymyxin sulfate. This study compared the effectiveness of MYP and MPN methods for detecting and enumerating B. cereus in raw and high-temperature, short-time pasteurized skim (0.5%), 2%, and whole (3.5%) bovine milk stored at 4°C for 96 h. Each milk sample was inoculated with B. cereus EZ-Spores and sampled at 0, 48, and 96 h after inoculation. There were no differences (P > 0.05) in B. cereus populations among sampling times for all milk types, so data were pooled to obtain overall mean values for each treatment. The overall B. cereus population mean of pooled sampling times for the MPN method (2.59 log CFU/ml) was greater (P milk samples ranged from 2.36 to 3.46 and 2.66 to 3.58 log CFU/ml for inoculated milk treatments for the MYP plate count and MPN methods, respectively, which is below the level necessary for toxin production. The MPN method recovered more B. cereus, which makes it useful for validation research. However, the MYP plate count method for enumeration of B. cereus also had advantages, including its ease of use and faster time to results (2 versus 5 days for MPN).

  19. Novo meio seletivo-indicador para detecção de Aeromonas e Plesiomonas: ágar UNISC New selective indicator medium for detection of Aeromonas and Plesiomonas: UNISC agar

    Directory of Open Access Journals (Sweden)

    Marion Pereira da Rocha

    2008-08-01

    Full Text Available Avaliou-se um novo meio seletivo-indicador (ágar UNISC para o isolamento de enteropatógenos clássicos e Aeromonas e Plesiomonas shigelloides. A capacidade de fermentação da xilose é indicada pela coloração amarela (fermentadores ou azul (não fermentadores que, aliada à prova da oxidase, constitui-se em indicador para a detecção de Aeromonas spp e Plesiomonas shigelloides. A produtividade e seletividade, avaliadas pelos índice de contagem absoluta e índice de contagem relativa indicam-no como uma alternativa aos coprocultivos clássicos porque permite, num só meio, o isolamento de Escherichia coli, Shigella spp, Salmonella spp, bem como, Aeromonas spp e Plesiomonas shigelloides, favorecendo o diagnóstico laboratorial das gastroenterites.We evaluated a new selective indicator medium (UNISC Agar for isolation of classical enteropathogens, Aeromonas spp and Plesiomonas shigelloides. The xylose fermentation capacity is indicated by a yellow color (fermenting agents or blue (no fermenting agent. This, together with the oxidase test, establishes it as an indicator for detecting Aeromonas and Plesiomonas shigelloides. Its productivity and selectivity, as assessed using the absolute count index and relative count index, indicate it as an alternative to the classical feces culturing media. This is because, in a single medium, it enables isolation of Escherichia coli, Shigella spp and Salmonella spp, in addition to Aeromonas and Plesiomonas shigelloides, thereby favoring the laboratory diagnosis of gastroenteritis.

  20. Comparison of growth on mannitol salt agar, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, VITEK® 2 with partial sequencing of 16S rRNA gene for identification of coagulase-negative staphylococci.

    Science.gov (United States)

    Ayeni, Funmilola A; Andersen, Camilla; Nørskov-Lauritsen, Niels

    2017-04-01

    Mannitol salt agar (MSA) is often used in resources' limited laboratories for identification of S. aureus however, coagulase-negative staphylococci (CoNS) grows and ferments mannitol on MSA. 171 strains of CoNS which have been previously misidentified as S. aureus due to growth on MSA were collected from different locations in Nigeria and two methods for identification of CoNS were compared i.e. ViTEK 2 and MALDI-TOF MS with partial 16S rRNA gene sequencing as gold standard. Partial tuf gene sequencing was used for contradicting identification. All 171 strains (13 species) grew on MSA and ferments mannitol. All tested strains of S. epidermidis, S. haemolyticus, S. nepalensis, S. pasteuri, S. sciuri,, S. warneri, S. xylosus, S. capitis were correctly identified by MALDI-TOF while variable identification were observed in S. saprophyticus and S. cohnii (90%, 81%). There was low identification of S. arlettae (14%) while all strains of S. kloosii and S. gallinarum were misidentified. There is absence of S. gallinarum in the MALDI-TOF database at the period of this study. All tested strains of S. epidermidis, S. gallinarum, S. haemolyticus, S. sciuri,, S. warneri, S. xylosus and S. capitis were correctly identified by ViTEK while variable identification were observed in S. saprophyticus, S. arlettae, S. cohnii, S. kloosii, (84%, 86%, 75%, 60%) and misidentification of S. nepalensis, S. pasteuri. Partial sequencing of 16S rRNA gene was used as gold standard for most strains except S. capitis and S. xylosus where the two species were misidentified by partial sequencing of 16S rRNA contrary to MALDI-TOF and ViTEK identification. Tuf gene sequencing was used for correct identification. Characteristic growth on MSA for CoNS is also identical to S. aureus growth on the media and therefore, MSA could not differentiate between S. aureus and CoNS. The percentage accuracy of ViTEK was better than MALDI-TOF in identification of CoNS. Although partial sequencing of

  1. Evaluation of the control ability of five essential oils against Aspergillus section Nigri growth and ochratoxin A accumulation in peanut meal extract agar conditioned at different water activities levels.

    Science.gov (United States)

    Passone, María A; Girardi, Natalia S; Etcheverry, Miriam

    2012-10-15

    Essential oils (EOs) from boldo [Pëumus boldus Mol.], poleo [Lippia turbinata var. integrifolia (Griseb.)], clove [Syzygium aromaticum L.], anise [Pimpinella anisum] and thyme [Thymus vulgaris]) obtained by hydrodistillation were evaluated for their effectiveness against the growth of Aspergillus niger aggregate and A. carbonarius and accumulation of ochratoxin A (OTA). The evaluation was performed by compound dissolution at the doses of 0, 500, 1500 and 2500μL/L in peanut meal extract agar (PMEA) and exposure to volatiles of boldo, poleo (0, 1000, 2000 and 3000μL/L) and clove oils (0, 1000, 3000 and 5000μL/L), taking into account the levels of the water activity of the medium (a(W) 0.98, 0.95, 0.93). Statistical analyses on growth of Aspergillus strains indicated that the major effect was produced by oil concentrations followed by substrate a(W), and that reductions in antifungal efficiency of the oils tested were observed in vapor exposure assay. At all a(W) levels, complete fungal growth inhibition was achieved with boldo EO at doses of 1500 and 2000μL/L by contact and volatile assays, respectively. Contact exposure by poleo and clove EOs showed total fungal inhibition at the middle level tested of 1500μL/L, regardless of a(W), while their antifungal effects in headspace volatile assay were closely dependent on medium a(W). The fumigant activity of poleo (2000μL/L) and clove oils (3000μL/L) inhibited growth rate by 66.0% and 80.6% at a(W) 0.98 and 0.93, respectively. OTA accumulation was closely dependent on a(W) conditions. The antiochratoxigenic property of the volatile fractions of boldo, poleo and clove EOs (1000μL/L) was more significant at low a(W) levels, inhibition percentages were estimated at 14.7, 41.7 and 78.5% at a(W) 0.98, 0.95 and 0.93, respectively. Our results suggest that boldo, poleo and clove oils affect the OTA biosynthesis pathway of both Aspergillus species. This finding leaves open the possibility of their use by vapor exposure

  2. Evaluación del crecimiento y producción de biomasa de dos cepas del género Pleurotus spp., cultivadas en un medio agar con diferentes sustratos

    Directory of Open Access Journals (Sweden)

    Carol Daniela Coello-Loor

    2017-12-01

    Full Text Available La velocidad de crecimiento radial (VCR (mm.h-1 y la producción de biomasa (PB (g.g-1 de sustrato seco son técnicas que puedan establecer el grado de adaptación y desarrollo de los hongos del género Pleurotus spp., a distintos sustratos que podrían emplearse en una fermentación en medio sólido. Las especies fueron Pleurotus sapidus (Ps y Pleurotus ostreatus IE8 (Po. El medio de cultivo sintético empleado fue el papa dextrosa agar (PDA, con un pH que va de 5.6 a 5.9, ideal para el crecimiento de hongos, tiene todos los componentes nutritivos, y ligera acidez que logran la inhibición del desarrollo de bacterias; diluido en 4 diferentes soluciones preparadas con los materiales residuales (solución cascarilla de arroz CaPDA, solución cáscara de maracuyá CmPDA, solución mezcla 50% Cascarilla de arroz+50% Cáscara de maracuyá CaCmPDA y agua destilada+PDA con el propósito de observar el crecimiento radial cada 24 horas y la producción de biomasa fúngica de estos hongos lignocelulósicos por su periodo de incubación y la adaptación a nivel in vitro. Los tratamientos que presentaron mejor comportamiento VCR fueron el PoCaPDA (0.569 y el PoCaCmPDA (0.549; la cepa que reporto valores más altos en VCR y PB fue el Pleurotus ostreatus y el mejor medio de cultivo fue el CaPDA, en ambas variables; mientras, la mayor producción de biomasa fue en Pleurotus sapidus en CaPDA (0.1727 y el Pleurotus ostreatus IE8 en CmPDA (0.1722, CaPDA (0.1706 y PDA (0.1694.

  3. Crecimiento y habilidad decolorante potencial de Hyphomycetes (Deuteromycetes de Río Santiago sobre medio agarizado suplementado con cromóforos sintéticos Growth and potential decolorizing ability of Hyphomycetes (Deuteromycetes from Río Santiago on agar medium supplemented with synthetic chromophores

    Directory of Open Access Journals (Sweden)

    Romina Liberto

    2005-12-01

    Full Text Available Se analizó la capacidad de Dictyosporium triramosum, Minimidochium parvum y Tetraploa aristata, aisladas de materia orgánica colectada en Río Santiago (Provincia de Buenos Aires, Argentina, para crecer y decolorar medios agarizados y suplementados con diferentes cromóforos sintéticos al 0,01 % (p v-1. Cristal violeta y verde brillante redujeron el crecimiento de las 3 cepas revelando los mayores porcentajes de inhibición. Mientras que eosina y rosa de bengala no afectaron a D. triramosum, valores superiores al 50 % de inhibición se observaron en M. parvum y T. aristata. Rojo congo y rojo neutral redujeron a D. triramosum y M. parvum en un 12-17 %, pero no a T. aristata. D. triramosum y T. aristata no resultaron afectados por azul de toluidina, mientras M. parvum fue inhibido por el colorante. Rojo de metilo sólo inhibió a M. parvum y T. aristata. Las 3 cepas probadas revelaron capacidad para decolorar el medio suplementado con azul de toluidina y rojo de metilo. D. triramosum decoloró además el medio suplementado con cristal violeta y rojo congo, y T. aristata el medio con cristal violeta y rojo neutral. Ninguno de los hongos estudiados decoloró los medios con eosina, rosa de bengala y verde brillante.The ability of Dictyosporium triramosum, Minimidochium parvum and Tetraploa aristata, isolated from organic matter collected in Río Santiago (Buenos Aires Province, Argentina, to grow and decolorize agar media supplemented with different synthetic chromophores at 0.01% (w v-1 was analyzed. Crystal violet and brilliant green reduced the growth of the three strains showing the highest inhibition percentages. While eosin and rose bengal did not affect D. triramosum, growth inhibition values superior to 50 % were observed for M. parvum and T. aristata. Congo red and neutral red inhibited growth of both D. triramosum and M. parvum in a 12-17%, but those dyes did not reduced T. aristata growth. D. triramosum and T. aristata were not affected

  4. EFFICIENCY OF THE ENRICHMENT BROTHES (LEB1 AND LEB2 AND SELECTIVE AGARS (LPM AND LSAB-CAN TO ISOLATE BACTERIA OF THE GENUS Listeria IN MEAT AND RESIDUAL WATER OF WASHING CARCASS EFICIÊNCIA DOS CALDOS DE ENRIQUECIMENTO (LEB1 E LEB2 E DOS ÁGARES SELETIVOS (LPM E LSAB-CAN NO ISOLAMENTO DE BACTÉRIAS DO GÊNERO Listeria EM CARNE BOVINA E ÁGUA RESIDUÁRIA DE LAVAGEM DE CARCAÇA

    Directory of Open Access Journals (Sweden)

    Albenones José de Mesquita

    2007-09-01

    Full Text Available

    In this paper it was observed the efficiency of enrichment brothes for Listeria (LEB1 and LEB2, associated to the passage of the culture through a 0.25% potassium hidroxide solution, verifying that the secondary enrichment broth (LEB2 and LEB2KOH was better than the primary enrichment broth (LEB1KOH for this purpose. On the other hand, lithium chloride-phenylethanol-moxalactam agar and the selective Listeria agar base, supplemented with cicloheximide, acriflavine and nalidixic acid (LSAIB-CAN showed equivalency, at the statistic point of view (p=0.l442, in relation to the number of positive samples for Listeria spp., although the LSAB-CAN agar had given the greatest number of bacteria isolated from this genus.

    KEY-WORDS: Listeria; enrichment broth; selective agar.

    No presente trabalho verificou-se a eficiência dos caldos de enriquecimento para Listeria (LEB1 e LEB 2 associados à passagem da cultura por uma solução de hidróxido de potássio a 0,25%, constatando-se que o caldo de enriquecimento secundário (LEB2 e LEB2KOH foi superior ao caldo de enriquecimento primário (LEB1KOH. Por outro lado, o ágar cloreto de lítio-feniletanol-moxalactam (LPM e o ágar base seletivo para Listeria, suplementado com cicloheximida, acriflavina e ácido nalidíxico (LSAB-CAN equivaleram-se estatisticamente (p= 0,l442 em relação ao número de amostras positivas para Listeria, embora o ágar LSAB-CAN tenha proporcionado um maior número de isolamentos da bactéria.

    PALAVRAS-CHAVE: Caldo de enriquecimento; ágar seletivo; Listeria.

  5. Desenvolvimento de uma reação em cadeia pela polimerase e comparação com a imunodifusão em gel de agar na detecção de infecções pelo vírus da leucemia bovina

    Directory of Open Access Journals (Sweden)

    Marcelo Fernandes Camargos

    2003-01-01

    Full Text Available A reação em cadeia pela polimerase (PCR foi utilizada para a detecção do vírus da leucemia bovina (VLB em leucócitos periféricos de bovinos infectados. Os iniciadores utilizados foram construídos para amplificar uma parte do gene env do VLB. Os produtos da PCR foram analisados por eletroforese em gel de agarose corados por brometo de etídeo. A especificidade analítica da PCR foi confirmada por restrição enzimática dos produtos da reação com Bam HI e também pela análise da seqüência de três amostras. Sessenta e cinco animais foram testados para a presença de anticorpos anti-VLB, pela imunodifusão em gel de agar (IDGA e pela PCR, para detecção direta do VLB. Houve 73,80% de concordância entre os dois testes. Quatro animais positivos na IDGA foram PCR negativos, enquanto 13 animais negativos na IDGA foram positivos na PCR. A sensibilidade diagnóstica obtida foi de 0,87 e a especificidade diagnóstica 0,62. A PCR desenvolvida pode ser uma ferramenta complementar no diagnóstico de infecções causadas pelo VLB, mas deve ter sua sensibilidade diagnóstica melhorada.

  6. Estudo comparativo entre as técnicas de diluição em caldo e diluição em ágar, nos antibiogramas para Candida: a comparative study Broth dilution and agar dilution methods applied to Candida sensitivity tests

    Directory of Open Access Journals (Sweden)

    Sydney Hartz Alves

    1992-06-01

    Full Text Available Os autores compararam o desempenho das técnicas de diluição em caldo e diluição em ágar, mediante a determinação da CIM (concentração inibitória mínima e da CFM (concentração fungicida mínima de antifúngicos poliênicos e imidazólicos, frente a diversas espécies de Candida. A concordância entre as técnicas foi variável em função do antifúngico utilizado. Os melhores percentuais de concordância ocorreram quando se realizou o teste com poliênicos. Os autores discutem aspectos que envolvem a problemática dos testes de sensibilidade de leveduras a antifúngicosThe performance of broth dilution method and agar dilution method were compared by MIC (minimal inhibitory concentration and MFC (minimal fungicidal concentration from Candida strains to polyene and imizadole anti-fungal agents. The concordance between these methods was drug dependent. The best percent of concordance were showed when the polyenes were tested. The problems of sensitivity test for yeasts to antifungal drugs are discussed

  7. Pitfalls using tributyrin agar screening to detect lipolytic activity in ...

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... lysis and synthesis of acylglycerides and other fatty acid esters. The true ... the addition of 1 M sodium hydroxide. Following treatment, DNA ... After cooling, 275 µl 7 M ammonium acetate (pH 7) was added, incubated for 5 min ...

  8. Mupirocin-mucin agar for selective enumeration of Bifidobacterium bifidum

    Czech Academy of Sciences Publication Activity Database

    Pechar, R.; Rada, V.; Parafati, L.; Musilová, S.; Bunešová, V.; Vlková, E.; Killer, Jiří; Mrázek, Jakub; Kmeť, V.; Svejštil, R.

    2014-01-01

    Roč. 191, č. 1 (2014), s. 32-35 ISSN 0168-1605 R&D Projects: GA ČR GA13-08803S Institutional support: RVO:67985904 Keywords : probiotics * Bifidobacterium bifidum * selective enumeration Subject RIV: EE - Microbiology, Virology Impact factor: 3.082, year: 2014

  9. agar de la rhodophycée Gelidium spin

    African Journals Online (AJOL)

    .

    (Lamouroux), au Japon, ainsi que d'autres espèces vivant au Chili font l'objet de collectes naturelles et de quelques essais de culture en mer tels qu'en Espagne, les tonnages récoltés sont très différents selon les pays [7]. En Tunisie, l'intérêt à la valorisation des algues marines est très récent, comparé à plusieurs pays.

  10. S S Bhatn.agar. Life and Times

    Indian Academy of Sciences (India)

    ment Studies, New Delhi. His research interests ... tific and Industrial Research, Bhatnagar had the courage to publicly touch the ... scholarships and giving private coaching. In 1908 .... advice of the commerce member of his council, (Sir) Arcot.

  11. Pitfalls using tributyrin agar screening to detect lipolytic activity in ...

    African Journals Online (AJOL)

    The metagenomics approach is an efficient method for obtaining novel biocatalysts and useful genes from uncultured microorganisms within diverse environments. In this study, we constructed a metagenomic library using a South African deep mine biofilm sample. The library was screened for lipolytic activity using LB ...

  12. Conventional and microwave pyrolysis of a macroalgae waste from the Agar-Agar industry. Prospects for bio-fuel production.

    Science.gov (United States)

    Ferrera-Lorenzo, N; Fuente, E; Bermúdez, J M; Suárez-Ruiz, I; Ruiz, B

    2014-01-01

    A comparative study of the pyrolysis of a macroalgae industrial solid waste (algae meal) in an electrical conventional furnace and in a microwave furnace has been carried out. It was found that the chars obtained from both pyrolyses are similar and show good properties for performing as a solid bio-fuel and as a precursor of activated carbon. Bio-oils from conventional pyrolysis have a greater number of phenolic, pyrrole and alkane compounds whereas benzene and pyridine compounds are more predominant in microwave pyrolysis with a major presence of light compounds. The bio-gas fraction from microwave pyrolysis presents a much higher syngas content (H2+CO), and a lower CO2 and CH4 proportion than that obtained by conventional pyrolysis. Yields are similar for both treatments with a slightly higher gas yield in the case of microwave pyrolysis due to the fact that microwave heating favors heterogeneous reactions between the gases and the char. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Mechanisms of bands and spirals formation during the drying of watery solutions of mercury (II) chloride with agar-agar

    International Nuclear Information System (INIS)

    Suarez-DomInguez, Edgardo Jonathan; Betancourt-Mar, Juvencio Alberto

    2005-01-01

    It is proposed two mechanisms to explain the formation of periodic and non periodic bands and spirals as thin films of gelatinous aqueous solutions of mercury (II) chloride are dried. The first mechanism supposes an homogeneous drying, where the height of the film decreases at constant rate, forming Liesegang bands. The second mechanism implies a non homogeneous drying where an evaporation front drives the formation of periodic bands and spirals

  14. Rapid serum agglutination and agar gel immunodiffusion tests associated to clinical signs in rams experimentally infected with Brucella ovis Teste de soro aglutinação rápida e do teste de imunodifusão em gel de ágar associados aos sinais clínicos em carneiros infectados experimentalmente com Brucella ovis

    Directory of Open Access Journals (Sweden)

    Cristiane Nakada Nozaki

    2011-08-01

    Full Text Available The purpose of this study was to evaluate the agar gel immunodiffusion and the rapid serum agglutination tests associated to clinical signs in rams experimentally infected with Brucella ovis. The serological profile during the 12 months of infection showed a large fluctuation of antibodies that favors the failure in the diagnostic. The evaluation of tests after the experimental infection allowed to suggest that none of the tests were able to detect the infection throughout the period of study. The study reinforces the importance of considering the clinical signs to support the diagnosis of Brucella ovis infection in rams.O objetivo deste estudo foi avaliar o uso do teste de imunodifusão em gel de ágar e o teste sorológico de aglutinação rápida comparados aos sinais clínicos em carneiros infectados experimentalmente com Brucella ovis para o diagnóstico confirmatório da brucelose ovina. O perfil sorológico durante os 12 meses pós-infecção mostrou flutuação da resposta por anticorpos, que favorece a falha no diagnóstico. A avaliação dos testes indicou que nenhum dos testes foi capaz de detectar a infecção durante todo o período de estudo. O estudo ressalta a importância de considerar os sinais clínicos para apoiar o diagnóstico confirmatório da infecção por Brucella ovis em carneiros.

  15. 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.

  16. NAS agar is more suitable than McKay agar for primary culture of Streptococcus milleri group (SMG) fastidious bacteria, S-intermedius in particular

    Czech Academy of Sciences Publication Activity Database

    Raclavský, V.; Novotný, R.; Starý, L.; Navrátilová, Lucie; Zatloukal, J.; Jakubec, P.; Zápalka, M.; Kopřiva, F.; Kolek, V.

    2017-01-01

    Roč. 62, č. 1 (2017), s. 11-15 ISSN 0015-5632 R&D Projects: GA MŠk(CZ) LO1304 Institutional support: RVO:61389030 Keywords : cystic-fibrosis patients * disease Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Microbiology Impact factor: 1.521, year: 2016

  17. Growth and study of barium oxalate single crystals in agar gel

    Indian Academy of Sciences (India)

    Unknown

    tive Powder Diffraction Data Interpretation and Indexing. Program, Version 2.2) was used to calculate 'd' values. Calculated 'd' values matched with reported values. Table. 2 shows calculated unit cell parameters. Table 2. Calculated unit cell parameters. Parameters. Barium oxalate. System. Monoclinic (P) a. 8⋅2426 Å b.

  18. Non-immunological precipitation by the neutral detergent triton X-100 in agar gel diffusion.

    OpenAIRE

    Mansheim, B J; Stenstrom, M L

    1980-01-01

    Triton X-100 can be used to clarify vague immunoprecipitin lines from bacterial antigens; however, non-immunological precipitation can lead to mistaken interpretation of immunodiffusion results. If Triton X-100 is added directly to the gel during preparation rather than to the antigen well, this detergent artifact can be eliminated.

  19. Agar pronkssõduriga võitleja sai kanepisuitsetamise eest trahvi / Katrin Rohtla, Siim Randla

    Index Scriptorium Estoniae

    Rohtla, Katrin, 1966-

    2006-01-01

    Aktiivse pronkssõduri vastasena tuntust kogunud Isamaaliidu liige Kalev Rebane sai Läänemaal Peraküla rannas kanepi suitsetamise eest politseilt 9000 krooni trahvi. Isamaa ja Res Publica Liidu liikmed on teinud ettepaneku noormees erakonnast välja arvata. Lisa: Mille eest koostati protokoll?

  20. Teaduspargist võrsub eriti agar gasell / Ain Alvela ; kommenteerinud Seren Eilmann

    Index Scriptorium Estoniae

    Alvela, Ain, 1967-

    2010-01-01

    Tallinna tehnoloogiapargi Tehnopol ja Tartu teaduspargi ettevõtlusinkubaatorid pakuvad ettevõtluskeskkonda kiiret arengut taotlevatele ettevõtetele. Tehnopolis on gaselli staatuse saanud 22 firmat, Tartu teaduspargis 13 firmat. AS-ist Proekspert, OÜ-st Interfire. Tabel

  1. Major Proteins of the Amyloplast of Agar and Soil - Grown Potato Tubers

    DEFF Research Database (Denmark)

    Hald, Simon; Blennow, Andreas; Stensballe, Allan

    and total tuber extracts by SDS-PAGE and the specific activities of marker enzymes for amyloplast, cytosol, mitochondria and the vacuole. SDS-PAGE separated amyloplast and starch granule proteins were in-gel digested with trypsin, analyzed by mass spectrometry, and identified by searches against presently...

  2. Activity of two strobilurin fungicides against three species of decay fungi in agar plate tests

    Science.gov (United States)

    Juliet D. Tang; Tina Ciaramitaro; Maria Tomaso-Peterson; Susan V. Diehl

    2017-01-01

    The objective of this study was to examine the toxicity of strobilurin fungicides against wood decay fungi in order to assess their potential to act as a co-biocide for copper-based wood protection. Two strobilurin fungicides, Heritage (50% azoxystrobin active ingredient) and Insignia (20% pyraclostrobin active ingredients), and copper sulfate pentahydrate were tested...

  3. Toxicity of zinc oxide nanoparticles to the annelid Enchytraeus crypticus in agar-based exposure media

    Czech Academy of Sciences Publication Activity Database

    Hrdá, K.; Opršál, J.; Knotek, P.; Pouzar, M.; Vlček, Milan

    2016-01-01

    Roč. 70, č. 11 (2016), s. 1512-1520 ISSN 0366-6352 Institutional support: RVO:61389013 Keywords : terrestrial ecotocicity test * zinc ocide nanoparticles * potworm Subject RIV: DJ - Water Pollution ; Quality Impact factor: 1.258, year: 2016

  4. PENGARUH KONSENTRASI KITOSAN TERHADAP AKTIVITAS ANTIBAKTERI DENGAN METODE DIFUSI AGAR (SUMUR

    Directory of Open Access Journals (Sweden)

    Fibra Nurainy

    2012-12-01

    Full Text Available The aim of this work was to obtain the minimal concentration of chitosan which possess antibacterial characteristic. The concentrations of chitosan that used were 0%; 0,2%; 0,4%; 0,6%; and 0,8% (w/v, whereas bacteria cultures used to examine antibacterial activity of chitosan were Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Well method (gel diffusion was utilized to test the chitosan antibacterial activity.  The result was analyzed using descriptive method and presented in the graphic form.  The result showed the activity of chitosan restraint as antibacterial.  The test of chitosan antibacterial activity utilizes gel diffusion (well method. The data analyzed descriptively and presented in the graphic form.  The result  showed the activity of chitosan restraint as anti bacteria against Staphylococcus aureus, Bacillus subtilis or Escherichia coli with the highest restraint diameter was noticed at the addition of 0,2% chitosan, which were 20,27 mm/mg chitosan, 24,50 mm/mg chitosan and 31,53 mg chitosan, respectively.  The lowest restraint diameter was found at the addition of 0,8% chitosan, which were 6,82 mm/mg chitosan, 12,14 mm/mg chitosan and 14,23 mm/mg chitosan, respectively. Keywords:  Antibacterial activity, chitosan, gel diffusion method

  5. Comparison of Excretory-Secretory and Somatic Antigens of Ornithobilharzia turkestanicum in Agar Gel Diffusion Test

    Directory of Open Access Journals (Sweden)

    H Miranzadeh

    2008-12-01

    Full Text Available Background: Ornithobilharziosis as one of the parasitic infections may give rise to serious economic problems in animal husbandry. The Aim of the study was to prepare and compare the somatic and excretory-secretory (ES antigens of O. tur­kestanicum in gel diffusion test. Methods: Excretory-secretory (ES and somatic antigens of Ornithobilharzia turkestanicum were prepared from collected worms from mesentric blood vessels of infected sheep. The laboratory bred rabbits were immunized with antigens and then antisera were prepared. The reaction of antigens and antisera was observed in gel diffusion test. Results: ES antigens of this species showed positive reaction with antisera raised against ES and also somatic antigens. Somatic antigens also showed positive reaction with antisera raised against somatic and also ES antigens. Conclusion: The antigenicity of O. turkestanicum ES and somatic antigens is the same in gel diffusion test.

  6. Can serums be replaced by Mueller‑Hinton agar in germ tube test ...

    African Journals Online (AJOL)

    Background: The germ tube test (GTT) is inexpensive, easy, and well‑defined test that differentiates Candida albicans (excluding Candida dubliniensis and Candida africana) from other species. The aim of this study was to evaluate various serums (i.e., human, rabbit, horse, and fetal bovine serum) used in the GTT and ...

  7. N-acetylgalatosamine-Mediated Regulation of the aga Operon by AgaR in Streptococcus pneumoniae

    NARCIS (Netherlands)

    Afzal, Muhammad; Shafeeq, Sulman; Ahmed, Hifza; Kuipers, Oscar P

    2016-01-01

    Here, we analyze the transcriptomic response of Streptococcus pneumoniae D39 to N-acetylgalactosamine (NAGa). Transcriptome comparison of S. pneumoniae D39 grown in NAGaM17 (0.5% NAGa + M17) to that grown in GM17 (0.5% Glucose + M17) revealed the elevated expression of various carbon metabolic

  8. Hydrolytic enzymes production by Aspergillus section Nigri in presence of butylated hydroxyanisole and propyl paraben on peanut meal extract agar.

    Science.gov (United States)

    Barberis, Carla L; Landa, María F; Barberis, Mauricio G; Giaj-Merlera, Guillermo; Dalcero, Ana M; Magnoli, Carina E

    2014-01-01

    In the last years, food grade antioxidants are used safely as an alternative to traditional fungicides to control fungal growth in several food and agricultural products. In this work, the effect of butylated hydroxyanisole (BHA) and propyl paraben (PP) on two hydrolytic enzyme activity (β-d-glucosidase and α-d-galactosidase) by Aspergillus section Nigri species under different water activity conditions (aW; 0.98, 0.95 and 0.93) and incubation time intervals (24, 48, 72 and 96h) was evaluated on peanut-based medium. The activity of two glycosidases, β-d-glucosidase and α-d-galactosidase, was assayed using as substrates 4-nitrophenyl-β-d-glucopyranosido and 4-nitrophenyl-α-d-galactopyranosido, respectively. The enzyme activity was determined by the increase in optical density at 405nm caused by the liberation of p-nitrophenol by enzymatic hydrolysis of the substrate. Enzyme activity was expressed as micromoles of p-nitrophenol released per minute. The major inhibition in β-d-glucosidase activity of A. carbonarius and A. niger was found with 20mmoll(-1) of BHA or PP at 0.98 and 0.95 aW, respectively, whereas for α-d-galactosidase activity a significant decrease in enzyme activity with respect to control was observed in A. carbonarius among 5 to 20mmoll(-1) of BHA or PP in all conditions assayed. Regarding A. niger, the highest percentages of enzyme inhibition activity were found with 20mmoll(-1) of BHA or PP at 0.95 aW and 96h. The results of this work provide information about the capacity of BHA and PP to inhibit in vitro conditions two of the most important hydrolytic enzymes produced by A. carbonarius and A. niger species. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  9. DETECTION OF BACTERIAL CYTOTOXIC ACTIVITIES FROM WATER-DAMAGED CEILING TILE MATERIAL FOLLOWING INCUBATION ON BLOOD AGAR

    Science.gov (United States)

    Samples of ceiling tiles with high levels of bacteria exhibited cytotoxic activities on a HEP-2 tissue culture assay. Ceiling tiles containing low levels of bacterial colonization did not show cytotoxic activities on the HEP-2 tissue culture assay. Using a spread plate procedure ...

  10. Extreme testing of undiluted e-cigarette aerosol in vitro using an Ames air-agar-interface technique.

    Science.gov (United States)

    Thorne, D; Hollings, M; Seymour, A; Adamson, J; Dalrymple, A; Ballantyne, M; Gaca, M

    2018-04-01

    There is a growing consensus that e-cigarettes hold the potential for reducing the harm associated with cigarette smoking. Recently published studies have reported in vitro testing of e-cigarettes, demonstrating reduced toxicological and biological effects. Few studies however have reported the use of e-cigarettes under extreme testing conditions. To assess the full mutagenic potential of a commercially available electronic-cigarette (Vype ePen), this study investigated the delivery of aerosol under extreme conditions, using a scaled-down 35 mm plate Ames bacterial reverse mutagenicity assay. S. typhimurium strains TA98, TA100, TA97, TA104 and E. coli WP2 uvrA pKM101 with or without metabolic activation (S9), were employed. Using a modified Vitrocell VC 10 exposure system 0, 180, 360, 540, 720 or 900 puffs of undiluted e-cigarette aerosol was generated and delivered to bacterial cultures aligned to reported human consumption data. The results demonstrate that no mutagenic activity was observed in any strain under any test condition even when exposed to 900 puffs of undiluted e-cigarette aerosols +/- S9. Positive control responses were observed in all strains +/- S9. Nicotine assessments demonstrated an increased and consistent aerosol delivery, with calculated maximum doses of ∼1 mg/mL delivery of nicotine. These data demonstrate the validity of this unique testing approach and adds further information to the growing weight of evidence that e-cigarettes offer substantially reduced exposure when compared to conventional cigarette smoke. For future in vitro assessments of next generation tobacco and nicotine products, the generation, delivery and testing of undiluted aerosols can now be considered. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  11. 3,6-Anhydro-l-galactose, a rare sugar from agar, a new anticariogenic sugar to replace xylitol.

    Science.gov (United States)

    Yun, Eun Ju; Lee, Ah Reum; Kim, Jung Hyun; Cho, Kyung Mun; Kim, Kyoung Heon

    2017-04-15

    The significance for anticariogenic sugar substitutes is growing due to increasing demands for dietary sugars and rising concerns of dental caries. Xylitol is widely used as an anticariogenic sugar substitute, but the inhibitory effects of xylitol on Streptococcus mutans, the main cause of tooth decay, are exhibited only at high concentrations. Here, the inhibitory effects of 3,6-anhydro-l-galactose (AHG), a rare sugar from red macroalgae, were evaluated on S. mutans, in comparison with those of xylitol. In the presence of 5g/l of AHG, the growth of S. mutans was retarded. At 10g/l of AHG, the growth and acid production by S. mutans were completely inhibited. However, in the presence of xylitol, at a much higher concentration (i.e., 40g/l), the growth of S. mutans still occurred. These results suggest that AHG can be used as a new anticariogenic sugar substitute for preventing dental caries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Identification of Brucella by MALDI-TOF mass spectrometry. Fast and reliable identification from agar plates and blood cultures.

    Directory of Open Access Journals (Sweden)

    Laura Ferreira

    Full Text Available BACKGROUND: MALDI-TOF mass spectrometry (MS is a reliable method for bacteria identification. Some databases used for this purpose lack reference profiles for Brucella species, which is still an important pathogen in wide areas around the world. We report the creation of profiles for MALDI-TOF Biotyper 2.0 database (Bruker Daltonics, Germany and their usefulness for identifying brucellae from culture plates and blood cultures. METHODOLOGY/PRINCIPAL FINDINGS: We created MALDI Biotyper 2.0 profiles for type strains belonging to B. melitensis biotypes 1, 2 and 3; B. abortus biotypes 1, 2, 5 and 9; B. suis, B. canis, B ceti and B. pinnipedialis. Then, 131 clinical isolates grown on plate cultures were used in triplicate to check identification. Identification at genus level was always correct, although in most cases the three replicates reported different identification at species level. Simulated blood cultures were performed with type strains belonging to the main human pathogenic species (B. melitensis, B. abortus, B. suis and B. canis, and studied by MALDI-TOF MS in triplicate. Identification at genus level was always correct. CONCLUSIONS/SIGNIFICANCE: MALDI-TOF MS is reliable for Brucella identification to the genus level from culture plates and directly from blood culture bottles.

  13. Nutrient limitation leads to penetrative growth into agar and affects aroma formation in Pichia fabianii, P. kudriavzevii and Saccharomyces cerevisiae

    NARCIS (Netherlands)

    van Rijswijck, Irma M H; Dijksterhuis, Jan; Wolkers-Rooijackers, Judith C M; Abee, Tjakko; Smid, Eddy J

    Among fermentative yeast species, Saccharomyces cerevisiae is most frequently used as a model organism, although other yeast species may have special features that make them interesting candidates to apply in food-fermentation processes. In this study, we used three yeast species isolated from

  14. Nutrient limitation leads to penetrative growth into agar and affects aroma formation in Pichia fabianii, P. kudriavzevii and Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Rijswijck, van I.M.H.; Dijksterhuis, J.; Wolkers-Rooijackers, J.C.M.; Abee, T.; Smid, E.J.

    2015-01-01

    Among fermentative yeast species, Saccharomyces cerevisiae is most frequently used as a model organism, although other yeast species may have special features that make them interesting candidates to apply in food-fermentation processes. In this study, we used three yeast species isolated from

  15. Study of Allelopathic Interaction of Wheat (Triticum aestivum L. and Some Weed Species Using Equal - Compartment – Agar Method

    Directory of Open Access Journals (Sweden)

    M. R Labbafi

    2012-02-01

    Full Text Available There are many methods for weed management one of them is putting allelopathic and cover crop in weed management programs. In order to study the effect of sowing time (delayed sowing, synchronic sowing and wheat cultivars (Shiraz, Roshan, Tabasi, Niknejad on allelopathic interaction of wheat and weed species (Secale cereale L., Avena ludoviciana L.: monocotyledon, Convolvulus arvensis L. and Vicia villosa L.: dicotyledon, an experiment was conducted with factorial arrangement in a completely randomized design and 4 replications. According to the results, the inhibitory effect of wheat on monocot weeds (oat and rye was more than in synchronic sowing and the inhibitory effect of wheat on dicot weeds (bindweed and vetch was more than in delayed sowing. Effect of wheat cultivars on rye and oat (except hypocotyls length was inhibitory and that of vetch was stimulatory. Hypocotyls length showed the most sensitivity to released allelochemicals from wheat cultivars, because root has the most contact with allelochemicals in the soil.

  16. Use of benzimidazole agar plates to assess fall armyworm (Lepidoptera: Noctuidae) feeding on excised maize and sorghum leaves

    Science.gov (United States)

    The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an economically significant pest of sorghum and maize. To screen sorghum and maize germplasm for resistance to fall armyworm feeding, field, greenhouse, or lab bioassays are often utilized individually or in combinatio...

  17. The electrophoretic softness of the surface of Staphylococcus epidermidis cells grown in a liquid medium and on a solid agar

    NARCIS (Netherlands)

    Kiers, PJM; van der Mei, HC; Busscher, HJ; Bos, R.R.M.

    Many Staphylococcus epidermidis strains possess capsule or slime layers and consequently the staphylococcal cell surface should be regarded as a soft, polyelectrolyte layer allowing electrophoretic fluid flow through a layer of fixed charges. The presence of such a soft layer decreases the energy

  18. Long-term Maintenance of Fungal Cultures on Perlite in Cryovials – an Alternative for Agar Slants

    Czech Academy of Sciences Publication Activity Database

    Homolka, Ladislav; Lisá, Ludmila

    2008-01-01

    Roč. 53, č. 6 (2008), s. 534-536 ISSN 0015-5632 R&D Projects: GA MŠk LC06066 Institutional research plan: CEZ:AV0Z50200510 Keywords : basidiomycete * perlite * long-term maintenance Subject RIV: EE - Microbiology, Virology Impact factor: 1.172, year: 2008

  19. Fine Needle Aspiration Using Improved Agar Microbiopsy is Highly Concordant With Renal Mass Final Diagnosis and Subclassification

    NARCIS (Netherlands)

    Schieven, Louise W.; Smedts, Frank; Hopman, Anton H.; van der Wijk, Jan; Nijman, Rien J.; de Jong, Igle J.

    2009-01-01

    Purpose: Computerized tomography and ultrasound are usually sufficient for preoperative evaluation of renal masses greater than 5 cm. For renal masses less than 5 cm additional histological evaluation could improve diagnosis and treatment decisions. We investigated the concordance between an

  20. Effets des différents doses d'agar du milieu de culture sur l'induction ...

    African Journals Online (AJOL)

    SARAH

    31 janv. 2014 ... récipients utilisés étaient des bacs en plastic munis du filtre d'aération sur le couvercle. Il a été garni de 100 ml de milieu de culture ... The containers used were plastic containers marked with the breather filter on the lid. ..... 1991; Brown et Atanassov, 1985 ; Reisch et Bingham,. 1980; Bingham et al., 1975).

  1. Light scattering sensor for real-time identification of Vibrio parahaemolyticus, V. vulnificus and V. cholera colonies on solid agar plates

    Science.gov (United States)

    The three most common pathogenic species of Vibrio, V. cholerae, V. parahemolyticus and V. vulnificus, are of major concern as water- and food-borne pathogens because of an increasing incidence of water and seafood related outbreaks and illnesses worldwide. Current methods are time-consuming and req...

  2. Continuous biosorption of Pb/Cu and Pb/Cd in fixed-bed column using algae Gelidium and granulated agar extraction algal waste.

    Science.gov (United States)

    Vilar, Vítor J P; Loureiro, José M; Botelho, Cidália M S; Boaventura, Rui A R

    2008-06-15

    Continuous metal ions biosorption from Pb/Cu and Pb/Cd solutions onto seaweed Gelidium sesquipedale and a composite material prepared from an industrial algal waste was performed in a packed bed column. A binary Langmuir equation describes well the equilibrium data and indicates a good adsorption capacity. In the sorption process, Cd and Cu break through the column faster than Pb due to its lower affinity for the biosorbent. An overshoot in the outlet Cd concentration was observed and explained by competitive adsorption between Pb and Cd, whereby the higher Pb affinity for the biosorbent displaces bound Cd ions. A small overshoot happens for Cu adsorption in the presence of Pb ions. Desorption using 0.1 M HNO3 as eluant, was 100% effective. A mass transfer model for the adsorption and desorption processes, considering an external and intraparticle film resistance, adequately simulates the column performance. A binary Langmuir equation was used to describe equilibrium for the saturation process and a mass action law for the desorption process. Elution process is defined as an ion exchange mechanism, between protons and metal ions.

  3. Continuous biosorption of Pb/Cu and Pb/Cd in fixed-bed column using algae Gelidium and granulated agar extraction algal waste

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Vitor J.P. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: vilar@fe.up.pt; Loureiro, Jose M. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: loureiro@fe.up.pt; Botelho, Cidalia M.S. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: cbotelho@fe.up.pt; Boaventura, Rui A.R. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: bventura@fe.up.pt

    2008-06-15

    Continuous metal ions biosorption from Pb/Cu and Pb/Cd solutions onto seaweed Gelidium sesquipedale and a composite material prepared from an industrial algal waste was performed in a packed bed column. A binary Langmuir equation describes well the equilibrium data and indicates a good adsorption capacity. In the sorption process, Cd and Cu break through the column faster than Pb due to its lower affinity for the biosorbent. An overshoot in the outlet Cd concentration was observed and explained by competitive adsorption between Pb and Cd, whereby the higher Pb affinity for the biosorbent displaces bound Cd ions. A small overshoot happens for Cu adsorption in the presence of Pb ions. Desorption using 0.1 M HNO{sub 3} as eluant, was 100% effective. A mass transfer model for the adsorption and desorption processes, considering an external and intraparticle film resistance, adequately simulates the column performance. A binary Langmuir equation was used to describe equilibrium for the saturation process and a mass action law for the desorption process. Elution process is defined as an ion exchange mechanism, between protons and metal ions.

  4. Comparison of the cystine-tryptic digest agar-carbohydrate co-agglutination and BACTEC Neisseria differentiation methods for identification of Neisseria gonorrhoeae in the clinical laboratory

    International Nuclear Information System (INIS)

    Morello, J.A.; Beheshti, S.; Bohnhoff, M.

    1980-01-01

    The author evaluated CTA-carbohydrate, BACTEC and co-agglutination systems to determine their accuracy for identifying N. gonorrhoeae strains and for distinguishing them from other Neisseria species. BACTEC is a radiometric assay based on the measurement of liberated radiolabelled CO 2 from metabolised carbohydrates which have been tagged with 14 C. (Auth.)

  5. Continuous biosorption of Pb/Cu and Pb/Cd in fixed-bed column using algae Gelidium and granulated agar extraction algal waste

    International Nuclear Information System (INIS)

    Vilar, Vitor J.P.; Loureiro, Jose M.; Botelho, Cidalia M.S.; Boaventura, Rui A.R.

    2008-01-01

    Continuous metal ions biosorption from Pb/Cu and Pb/Cd solutions onto seaweed Gelidium sesquipedale and a composite material prepared from an industrial algal waste was performed in a packed bed column. A binary Langmuir equation describes well the equilibrium data and indicates a good adsorption capacity. In the sorption process, Cd and Cu break through the column faster than Pb due to its lower affinity for the biosorbent. An overshoot in the outlet Cd concentration was observed and explained by competitive adsorption between Pb and Cd, whereby the higher Pb affinity for the biosorbent displaces bound Cd ions. A small overshoot happens for Cu adsorption in the presence of Pb ions. Desorption using 0.1 M HNO 3 as eluant, was 100% effective. A mass transfer model for the adsorption and desorption processes, considering an external and intraparticle film resistance, adequately simulates the column performance. A binary Langmuir equation was used to describe equilibrium for the saturation process and a mass action law for the desorption process. Elution process is defined as an ion exchange mechanism, between protons and metal ions

  6. Occurrence of soft sediment deformation at Dive Agar beach, west coast of India: possible record of the Indian Ocean tsunami (2004)

    Digital Repository Service at National Institute of Oceanography (India)

    Meshram, D.C.; Sangode, S.J.; Gujar, A.R.; Ambre, N.V.; Dhongle, D.; Porate, S.

    tsunami events (i.e., 2004 IOT), the only reported event after 1945 in the west coast. Alternative marine and terrigenous sands are characteristic of tsunami run-up and backwash deposits, while the dimensions of SSDs may be related to the <2 m magnitude...

  7. Interlaboratory comparison of agar dilution and Etest methods for determining the MICs of antibiotics used in management of Neisseria meningitidis infections

    NARCIS (Netherlands)

    Vázquez, Julio A.; Arreaza, Luisa; Block, Colin; Ehrhard, Ingrid; Gray, Stephen J.; Heuberger, Sigrid; Hoffmann, Steen; Kriz, Paula; Nicolas, Pierre; Olcen, Per; Skoczynska, Anna; Spanjaard, Lodewijk; Stefanelli, Paola; Taha, Muhamed-Kheir; Tzanakaki, Georgina

    2003-01-01

    Previous studies have shown that there is considerable variation in the methods and media used to determine the susceptibility of Neisseria meningitidis to antimicrobial agents in different countries. In this study, national and regional reference laboratories used a standardized methodology to

  8. Effectiveness of entomopathogenic nematode Steinernema feltiae in agar gel formulations against larvae of the Colorado potato beetle, Leptinotarsa decemlineata (Say.) (Coleoptera: Chrysomelidae)

    Czech Academy of Sciences Publication Activity Database

    Hussein, Hany; Adel, M. M.; Gelbič, Ivan

    2012-01-01

    Roč. 7, č. 1 (2012), s. 77-82 ISSN 1895-104X Institutional research plan: CEZ:AV0Z50070508 Keywords : anti-desiccant * foliar application * drought Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 0.818, year: 2012

  9. Isolation and identification of Metarhizium anisopliae from Chilo ...

    African Journals Online (AJOL)

    agar culture media: potato dextrose agar medium (PDA), potato dextrose with 1% (w/v) peptone agar medium (PPDA), and oatmeal agar medium (OMA). 16 different isolates were identified as Metarhizium anisopliae (Metschnikoff) based on ...

  10. Comparison of media for enumeration of Clostridium perfringens from foods

    NARCIS (Netherlands)

    Jong, A.E.I. de; Eijhusen, G.P.; Brouwer-Post, E.J.F.; Grand, M.; Johansson, T.; Kärkkäinen, T.; Marugg, J.; Veld, P.H. in 't; Warmerdam, F.H.M.; Wörner, G.; Zicavo, A.; Rombouts, F.M.; Beumer, R.R.

    2003-01-01

    Many media have been developed to enumerate Clostridium perfringens from foods. In this study, six media [iron sulfite (IS) agar, tryptose sulfite cycloserine (TSC) agar, Shahidi Ferguson perfringens (SFP) agar, sulfite cycloserine azide (SCA), differential clostridial agar (DCA), and oleandomycin

  11. Evaluation of culture media for growth and sporulation of ...

    African Journals Online (AJOL)

    Colocasia esculenta) in Cameroon and no information is yet available on its culture on common media. Six artificial media, V6 juice agar, V8 juice agar, V8m juice agar, potato dextrose agar, onion agar and taro leaf agar were assessed in vitro to ...

  12. Miscellaneous information

    NARCIS (Netherlands)

    NN,

    1949-01-01

    Prospects for an Indonesian Agar-agar Industry. – An Indonesian agar-agar industry seems possible. Seaweeds containing a sufficient percentage of agar-agar to make them eligible for industrial purposes, are found in suitable quantities in Indonesian waters. Dr J. S. Zaneveld, the recently arrived

  13. Multicenter Study of Method-Dependent Epidemiological Cutoff Values for Detection of Resistance in Candida spp. and Aspergillus spp. to Amphotericin B and Echinocandins for the Etest Agar Diffusion Method

    DEFF Research Database (Denmark)

    Espinel-Ingroff, A; Arendrup, M; Cantón, E

    2017-01-01

    Method-dependent Etest epidemiological cutoff values (ECVs) are not available for susceptibility testing of either Candida or Aspergillus species with amphotericin B or echinocandins. In addition, reference caspofungin MICs for Candida spp. are unreliable. Candida and Aspergillus species wild-typ...

  14. Studies on the Effects of Media on Growth and Nutritional ...

    African Journals Online (AJOL)

    The effects of different solutions and media on growth and nutrient composition of Pleurotus tuber-regium were investigated. The different solutions used are glucose, fructose, sucrose and Knop\\'s solutions. The media used are cassava agar, cocoyam agar, corn agar, potato agar and yam agar. Glucose solution produced ...

  15. Spencer et al., Afr. J. Infect. Dis.

    African Journals Online (AJOL)

    cadewumi

    Conclusion: In conclusion, Pelvic inflammatory disease is a major health problem in ... cultivated on Blood agar, McConkey agar and Chocolate agar media and .... had mean cidal effects of 80%, 76% and 54% respectively against all the ...

  16. Incidence of bacteraemia following teeth extraction at the dental ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... genital or acquired heart disease, or those fitted with a valvular prosthesis ... ments published reports on the prevalence, aetiologic agents and risk ... cultured onto plates of blood agar, chocolate agar and MacConkey agar.

  17. Influence of culturing conditions on growth and sporulation of ...

    African Journals Online (AJOL)

    Drechslera hawaiiensis is responsible for foliar blight disease in Marsilea minuta L., a common weed of rice. Experiments were conducted for the determination of nutritional and climatic requirements of this pathogen. Five culture media viz. malt extract agar, potato dextrose agar, Richard's agar, water agar and Czapek Dox ...

  18. Microbial handflora of nursing services workers in a Nigerian ...

    African Journals Online (AJOL)

    The samples were inoculated onto dried Blood agar, MacConkey agar, Mannitol salt agar and Muellar-Hinton agar plates and incubated aerobically at 37°C for 18-24 hours. Overall, 38% of the cultures yielded growth, while 52% of the nurses yielded growth as against 75% of the ward-maids. The bacterial isolates are ...

  19. Download this PDF file

    African Journals Online (AJOL)

    Administrator

    method on 4% Salt Muellar Hinton II agar for the Methicillin and non salted Muellar Hinton II agar for the other antibiotics. (NCCLS M100S9). Results: The prevalence of Staphylococcus aureus in .... for the isolate before spreading on Salted Muellar. Hinton II agar. We ensured uniform depth of the. Muellar Hinton II agar in all ...

  20. Türk Fermente Sucuğundan İzole Edilen Laktobasillerin Hidrojen Peroksit ve Hidrojen Sülfür Oluşturma Özelliklerinin Saptanması

    OpenAIRE

    Özdemir, Haydar

    2015-01-01

    This study was made with aim to determine H2O2 and H2S forming properties of some lactobacilli (L. sake, L curvatus, L. plantarum)isolated from Turkish fermented sausages. H2O2 forming properties of lactobacilli were determined in MRS-Pyrolusit agar and MRS-ABTS- Peroxidase agar while, H2S forming properties were determined in Lead Acetate agar, Lysine Iron agar and Triple Sugar Iron agar. The 49 strains (77.7%) in MRS-Pyrolusit agar, 52 strains (82.5%) in MRS-ABTS-Peroxidase agar were reacte...

  1. Morphological Characterization and Determination of Aflatoxin-Production Potentials of Aspergillus flavus Isolated from Maize and Soil in Kenya

    OpenAIRE

    Matome Gabriel Thathana; Hunja Murage; Akebe Luther King Abia; Michael Pillay

    2017-01-01

    This study aimed at morphologically identifying Aspergillus flavus in soil and maize and at determining their aflatoxin-producing potentials. Five hundred and fourteen isolates obtained from maize and soil in Kenya were cultivated on Czapeck Dox Agar, Malt Extract Agar, Sabouraud Dextrose Agar, Potato Dextrose Agar, and Rose-Bengal Chloramphenicol Agar. Isolates were identified using macro-morphological characteristics. Micromorphological characteristics were determined using slide cultures. ...

  2. Growth and Cultural Characteristics of Ophiocordyceps longissima Collected in Korea

    OpenAIRE

    Sung, Gi-Ho; Shrestha, Bhushan; Han, Sang-Kuk; Sung, Jae-Mo

    2011-01-01

    We investigated the effect of nutritional and environmental factors on Ophiocordyceps longissima mycelial growth. The longest colony diameter was observed on Schizophyllum (mushroom) genetics complete medium plus yeast extract, Schizophyllum (mushroom) genetics minimal medium, and Sabouraud dextrose agar (SDA); however, malt-extract yeast-extract agar, SDA plus yeast extract, yeast-extract malt-extract peptone dextrose agar, SDA, oatmeal agar, and potato dextrose agar showed higher mycelia de...

  3. Screening of chitinolytic actinomycetes for biological control of Sclerotium rolfsii stem rot disease of chilli

    OpenAIRE

    Pranee Pattanapipitpaisal; Rillapat Kamlandharn

    2012-01-01

    Two hundred and eighty three strains were isolated from rhizoshere-associated soils, from Ubon Ratchathani andSrisaket province, using Enrichment Media for isolation of Chitinase-producing Actinomycetes agar (EMCA agar). All strainswere screened for chitinolytic activity and sixty eight strains gave significant clear zone on EMCA agar plates. The selectedchitinolytic strains were assayed for in vitro antagonism against Sclerotium rolfsii using cornmeal agar (CMA agar) assayprocedure and the r...

  4. 与人脑白质磁共振弛豫时间近似的琼脂凝胶模型制备的实验研究%A model for an appropriate mix ratio of agar and gadoteric acid similar to the relaxation time of white matter of human brain: experiment study

    Institute of Scientific and Technical Information of China (English)

    葛祖峰; 龚向阳; 朱莉莉; 朱时锵; 吴伟; 单登峰

    2016-01-01

    目的:建立最接近正常成人脑白质弛豫时间的琼脂及钆对比剂浓度配比的磁共振实验模型.方法:将浓度为0.03 mmol/L、0.06 mmol/L、0.09 mmol/L、0.2 mmol/L、0.4 mmol/L、0.6 mmol/L及0.8 mmol/L的钆特酸葡胺分别与1.0%、1.5%(g/dl)的琼脂混合制成模型.将模型固定于成人志愿者头颅周围行MRI扫描得到T1、T2 map图.测定各种浓度配比模型的弛豫时间,分别得到T1、T2值的回归方程.通过单变量求解计算出接近人脑白质弛豫时间95%可信区间(均值)的浓度配比.并根据计算得到的浓度配比配制成模型后与志愿者脑白质弛豫时间作进一步对比验证.结果:人脑白质T1、T2值95%可信区间(均值)分别为792.14~848.59(820.36) ms、83.45~86.09(84.77) ms.0.10~0.11 mmol/L(0.11 mmol/L)钆特酸葡胺与1%琼脂混合、0.09~0.10 mmol/L(0.10 mmol/L)钆特酸葡胺与1.5%琼脂混合后的弛豫时间与脑白质T1值95%可信区间上限值与下限值(均值)接近;0.49~0.56 mmol/L(0.52 mmol/L)钆特酸葡胺与1%琼脂混合、0.08~0.12 mmol/L (0.10 mmol/L)钆特酸葡胺与1.5%琼脂混合的弛豫时间与脑白质T2值95%可信区间上限值与下限值(均值)近似.结论:1.5%的琼脂与0.09~0.10 mmol/L的钆特酸葡胺配比制成的模型T1、T2值均接近正常成人脑白质,能用于模拟正常成人的脑白质MRI信号.

  5. Evaluation of Standard and Modified M-FC, MacConkey, and Teepol Media for Membrane Filtration Counting of Fecal Coliforms in Water

    OpenAIRE

    Grabow, W. O. K.; Hilner, C. A.; Coubrough, P.

    1981-01-01

    MacConkey agar, standard M-FC agar, M-FC agar without rosolic acid, M-FC agar with a resuscitation top layer, Teepol agar, and pads saturated with Teepol broth, were evaluated as growth media for membrane filtration counting of fecal coliform bacteria in water. In comparative tests on 312 samples of water from a wide variety of sources, including chlorinated effluents, M-FC agar without rosolic acid proved the medium of choice because it generally yielded the highest counts, was readily obtai...

  6. [THE NATIONAL NUTRIENT MEDIUM FOR DIAGNOSTIC OF PURULENT BACTERIAL MENINGITIS].

    Science.gov (United States)

    Podkopaev, Ya V; Domotenko, L V; Morozova, T P; Khramov, M K; Shepelin, A P

    2015-05-01

    The national growth mediums were developed for isolating and cultivating of main agents of purulent bacterial meningitis--haemophilus agar, chocolate agar, PBM-agar. The growing and selective characteristics of developed growth mediums are examined. The haemophilus agar ensures growth of Haemophilus influenzae. The chocolate agar, PBM-agar ensure growth of Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae. By growing characteristics, the national growth mediums match foreign analogues. Under application of growth mediums with selective additions it is possible to achieve selective isolation of main agents of purulent bacterial meningitis with inhibition of growth of microbes-associates.

  7. Isolation and molecular identification of a Serratia strain from ...

    African Journals Online (AJOL)

    ONOS

    2010-04-05

    Apr 5, 2010 ... family Tupaiidae, mainly found in Southern China, India and Southeast Asia. The 17 known species of tree shrews ... for pathogenic coccus cultivation and nutrient agar culture dish and. MacConkey agar for pathogenic rod ...

  8. Production and partial purification of glucoamylase from Aspergillus ...

    African Journals Online (AJOL)

    SAM

    2014-05-21

    May 21, 2014 ... producing ability on potato dextrose agar using plate assay method fortified with starch agar, and ... under the terms of the Creative Commons Attribution License ... the process cost, consequently, the search for newer glu-.

  9. 10542 EVALUATION OF THE QUALITY OF MALTED ACHA-SOY ...

    African Journals Online (AJOL)

    MRS. HELEN O. AGU

    of ASC flour products was assessed in terms of proximate analysis, energy content ... with storage time. ... modified functional properties of seed components [13,14]. .... nutrient agar and potato dextrose agar were used for bacteria and mould ...

  10. CHAPTER ONE

    African Journals Online (AJOL)

    user

    sugar/electrolyte powder to treat every episode of diarrhoea in all young ... isolates using the modified agar disc and agar well-diffusion methods. ..... detection of virulence genes in Yersinia enterocolitica and ... to pasteurized milk. Journal of ...

  11. 2012 edition JMBR - CORRECTION.cdr

    African Journals Online (AJOL)

    FinePrint

    This study aims to determine the resistance pattern of bacterial isolates from various parts of the body in ... Antibiotic susceptibility test was done on nutrient agar using the agar diffusion ..... pathogens undergo evolutionary process. i.e. natural ...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    -clavulanic acid, cefoxitin, clindamycin, imipenem, metronidazole, moxifloxacin, piperacillin/tazobactam, tigecycline by agar dilution method previously. The inhibition zones of the same antibiotics including meropenem disc were determined by the disc diffusion on Brucella blood agar supplemented with haemin...

  13. Ammonia production and its possible role as a mediator of communication for Debaryomyces hansenii and other cheese-relevant yeast species

    DEFF Research Database (Denmark)

    Gori, Klaus; Mortensen, Henrik Dam; Arneborg, Nils

    2007-01-01

    lipolytica, and Geotrichum candidum was determined on glycerol medium (GM) agar and cheese agar. The ammonia production was found to vary, especially among yeast species, but also within strains of D. hansenii. In addition, variations in ammonia production were found between GM agar and cheese agar. Ammonia...... yeasts. On GM agar and cheese agar, D. hansenii showed ammonia production oriented toward neighboring colonies when colonies were grown close to other colonies of the same species; however, the time to oriented ammonia production differed among strains and media. In addition, an increase of ammonia...... production was determined for double colonies compared with single colonies of D. hansenii on GM agar. In general, similar levels of ammonia production were determined for both single and double colonies of D. hansenii on cheese agar....

  14. Gclust Server: 37252 [Gclust Server

    Lifescience Database Archive (English)

    Full Text Available ion factor required for growth of superficial pseudohyphae (which do not invade the agar substrate) but not ...ed for growth of superficial pseudohyphae (which do not invade the agar substrate) but not for invasive pseu

  15. Analysis of the action of X-rays on the multiplication of a unicellular chlorophyllous organism: the chlorophycee scenesdesmus crassus chod (1961)

    International Nuclear Information System (INIS)

    Gilet, R.; Ozenda, P.

    1961-01-01

    The technique of growing cultures on agar-agar has made it possible to obtain on single cultures results which had previously been acquired on populations of unicellular algae in a liquid medium. (authors) [fr

  16. Two new Cystoderma species from high Andean Ecuador

    DEFF Research Database (Denmark)

    Saar, I.; Læssøe, Thomas

    2006-01-01

    ABSTRACT: Two new agaric species, Cystoderma andinum and C. papallactae are described from high Andean Ecuador.......ABSTRACT: Two new agaric species, Cystoderma andinum and C. papallactae are described from high Andean Ecuador....

  17. Cultural Characteristics of Ophiocordyceps heteropoda Collected from Korea

    OpenAIRE

    Sung, Gi-Ho; Shrestha, Bhushan; Han, Sang-Kuk; Sung, Jae-Mo

    2011-01-01

    Isolates of Ophiocordyceps heteropoda (Kobayasi) collected from Mt. Halla on Jeju-do, Korea were tested for mycelial growth on different agar media and in the presence of different carbon and nitrogen sources. Similarly, isolates were also incubated at different temperatures as well as under continuous light and dark conditions. Growth was better on Hamada agar, basal medium, and malt-yeast agar, but poor on Czapek-Dox agar. Different carbon sources such as dextrin, saccharose, starch, lactos...

  18. Direct identification and recognition of yeast species from clinical material by using albicans ID and CHROMagar Candida plates.

    OpenAIRE

    Baumgartner, C; Freydiere, A M; Gille, Y

    1996-01-01

    Two chromogenic media, Albicans ID and CHROMagar Candida agar plates, were compared with a reference medium, Sabouraud-chloramphenicol agar, and standard methods for the identification of yeast species. This study involved 951 clinical specimens. The detection rates for the two chromogenic media for polymicrobial specimens were 20% higher than that for the Sabouraud-chloramphenicol agar plates. The rates of identification of Candida albicans for Albicans ID and CHROMagar Candida agar plates w...

  19. Diplodia natalensis Pole Evans, the causal agent of citrus gummosis ...

    African Journals Online (AJOL)

    The isolation media used were 1.5 per cent water agar, 1.5 per cent water agar + nystatin, and 1.5 per cent water agar + benomyl. ... When the isolates were tested for pathogenicity, only D. natalensis induced the disease symptoms in the inoculated 18-month-old rough lemon seedlings which were incubated after ...

  20. Bacteriology of the Anterior Genitalia of the Domestic House Cat ...

    African Journals Online (AJOL)

    The bacteriology of the anterior genitalia of the domestic house cat was determined using vaginal swabs collected from sixty apparently healthy female domestic cats (20 kittens, 20 pregnant and 20 non-pregnant adults). The swabs were streaked on blood agar, Mac Conkey agar and eosin methylene blue agar plates ...

  1. Laboratory diagnosis of gardnerella vaginalis vaginosis | Okwoli ...

    African Journals Online (AJOL)

    Gardnerella vaginalis grew predominantly in enriched culture media: Modified peptone-starch dextrose blood agar used for primary culture of organism, and also proteose peptone broth + cooked meat; Brain-heart infusion both + 5% human serum; Brain heart infusion starch agar + 5% blood, and chocolate agar.

  2. INSECT AND MYCOFLORA INTERACTIONS IN MAIZE FLOUR ...

    African Journals Online (AJOL)

    Fusarium moniliforme had the highest occurrence of 36.7%, 28.1% and 33.3% while Aspergillus flavus/parasiticus had a frequency of 3.2%, 3.1% and 3% on primary isolation media of czapek dox agar (CDA), potato dextrose agar (PDA) and sabouraud dextrose agar (SDA) respectively, in maize flour without T. castaneum.

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

    African Journals Online (AJOL)

    Swabs were subjected to Gram-stain and culture on Sabouraud dextrose agar. ... (71.4%) and fifty-five (87.3%) Candida isolates were correctly speciated by Rice Tween-80 Agar and API 20C AUX, respectively, while fifty-seven isolates (90.5%) were correctly assigned into the 3 groups of yeasts identified by CAN2 agar.

  4. The Vaginal Microbiota of Guinea Pigs

    OpenAIRE

    Hafner, L. M.; Rush, C. M.; Timms, P.

    2011-01-01

    The vaginae of four guinea pigs were swabbed and samples cultured aerobically on horse blood agar, in 5 per cent carbon dioxide on MRS agar or anaerobically on anaerobic horse blood agar. Vaginal microbiota consisted almost exclusively of gram-positive bacteria including Corynebacterium, Streptococcus, Enterococcus, Staphylococcus and Lactobacillus species.Keywords: guinea pigs, vaginal microbiota, vaginal vaccines.

  5. Optical anomaly in artificial cubic hieratite, K2[SiF6

    NARCIS (Netherlands)

    Göbel, Ole; ten Elshof, Johan E.; Kaminsky, W.; Hannss, M.

    2015-01-01

    Crystals of K2[SiF6] were grown in agar gel, silica gel and jelly. Crystals grown in agar gel or jelly exhibit birefringence and consist of six double refracting growth sectors, each having the shape of a tetragonal pyramid. Nevertheless, the structure of the crystals from agar gel could be refined

  6. Fungi obtained on various media from soil under banana trees near Logos in Nigeria

    Directory of Open Access Journals (Sweden)

    Aleksandra Ihnatowicz

    2014-08-01

    Full Text Available From the soil samples collected from beneath various banana plant, Musa paradisiaca L., 96 different species of soil fungi were isolated on medium: Ohio-Agar, Littmans-Agar, Martins Rose Bengal-Agar and identified. Four species of keratinophilic fungi were isolated by means of To-Ka-Va trap-hair method.

  7. Bacterial Isolates from Blood Samples of Patients in University of ...

    African Journals Online (AJOL)

    Bacterial Isolates from Blood Samples of Patients in University of Benin Teaching Hospital Benin City, Edo State, Nigeria. ... The thioglychollate broth was sub cultured onto blood agar plate for anaerobic incubation, while the brain heart infusion broth was sub cultured onto chocolate, blood agar and McConkey agar for ...

  8. Bacteriology of chronic discharging ears in Port Harcourt, Nigeria ...

    African Journals Online (AJOL)

    Methods: Ear swabs of discharging ears aseptically collected from 102 patients of various age groups attending Ear, Nose, and Throat out-patient clinic at University of Port Harcourt Teaching Hospital were cultured for bacterial agents using blood agar, chocolate agar and MacConkey agar. Culture plates were incubated ...

  9. An ultra melt-resistant hydrogel from food grade carbohydrates

    NARCIS (Netherlands)

    Thompson, Benjamin R.; Horozov, Tommy S.; Stoyanov, Simeon D.; Paunov, Vesselin N.

    2017-01-01

    We report a binary hydrogel system made from two food grade biopolymers, agar and methylcellulose (agar-MC), which does not require addition of salt for gelation to occur and has very unusual rheological and thermal properties. It is found that the storage modulus of the agar-MC hydrogel far

  10. Diplodia natalensis , Pole Evans: a causal agent of citrus gummosis ...

    African Journals Online (AJOL)

    Isolations were made from the barks of gummosis-infected citrus trees from orchards of the University of Ghana Agricultural Research Station at Kade. The isolation media used were 1.5% water agar, 1.5% water agar + nystatin and 1.5% water agar + benomyl. Four isolates including Diplodia natalensis Pole Evans, ...

  11. 2018-02-21T15:29:20Z https://www.ajol.info/index.php/all/oai oai:ojs ...

    African Journals Online (AJOL)

    article/95824 2018-02-21T15:29:20Z ijbcs:ART Gari agar as culture media for mycological studies Okorondu, SI Akujobi, CO Okorondu, JN Okorondu, MMO Gari agar was prepared by weighing 28 g of Gari, 14 g of agar powder and 8 g of Hibiscus ...

  12. Seroprevalence Of Enterohaemorrhagic Shigatoxin-Producing ...

    African Journals Online (AJOL)

    The enriched samples were plated on Eosin-Methylene Blue (EMB) agar and incubated at 37oC for 24 hours. Colonies showing a greenish metallic sheen on EMB agar were biochemically screened and those that were E. Coli were stored on nutrient agar (NA) slants at 4oC. The selected colonies were later plated on ...

  13. Isolation and Identification of a Brevibacterium linens strain ...

    African Journals Online (AJOL)

    nitrophenol (PNP). Subsequent subcultures in agar, nutrient agar plates and agar slants by streaking led to isolation of pure colonies. The pure culture could degrade up to 300 mg/L PNP in presence of yeast extract. It was Gram positive rods, ...

  14. Influence of substrates, light, filter paper and pH on the sporulation of Cercospora sojina

    Directory of Open Access Journals (Sweden)

    Diana Erica Gómez

    2013-06-01

    Full Text Available Fungi require special substrates for their isolation, vegetative growth and sporulation. In experiments conducted in the laboratory, the influence of substrates, light, filter paper and pH on the sporulation of Cercospora sojina conidia, the causal agent of soybean frogeye leaf spot, was assessed. The media potato sucrose agar, V-8 agar, tomato extract agar, soybean leaf extract agar, soybean seed extract agar, soybean meal agar, soybean flour agar and wheat flour agar were tested, added on the surface, with and without filter paper and under two light regimes, with 12 h light at 25°± 2°C and in the dark. A triple factorial 8x2x2 (substrates x light/dark x with/without filter paper design with four replicates was used. V-8 agar medium was employed and the pH was adjusted with HCl 0.1N or NaOH 0.1N before autoclaving to the values: 3, 4, 5, 6, 7 and 8, and the pH of V-8 agar medium is 6.7. The evaluation was done on the seventh day of incubation. Data underwent regression analysis. Sporulation was maximized on the agar media V-8, seed extract, oat flour, tomato extract, and potato sucrose in the presence of filter paper and 12h light. On V-8 medium, maximal sporulation was obtained with pH 6.7.

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

    DEFF Research Database (Denmark)

    Dalsgaard, Inger

    2001-01-01

    3, Diagnostic Sensitivity Test Agar) have been used in addition to media (Brain Heart Infusion Agar, Heart Infusion Agar, Columbia Blood Agar) normally utilized for cultivating fastidious bacteria. When testing marine pathogens, sodium chloride or seawater has been included in the media. Media...... pattern in fish pathogenic bacteria. The American guideline from The National Committee for Clinical Laboratory Standards (NCCLS) recommends Mueller-Hinton Agar for susceptibility testing of human pathogens and this validated medium appears to be adequate for the rapidly growing fish pathogens. Following......The available data concerning antimicrobial susceptibility testing of fish pathogens showed that there is no consensus to the basal medium currently being employed. Different media recommended for susceptibility testing of human pathogens (Mueller-Hinton Agar, Tryptone Soya Agar, Antibiotic Medium...

  16. Comparison of media for detection of fungi on spacecraft

    Science.gov (United States)

    Herring, C. M.; Brandsberg, J. W.; Oxborrow, G. S.; Puleo, J. R.

    1974-01-01

    Five media, including Trypticase soy agar (TSA; BBL) pour plates, spread plates of TSA, Mycophil agar with chloromycetin, Mycophil agar with chloromycetin and Actidione, and cornmeal agar with chloromycetin were quantitatively and qualitatively compared for the detection of fungi on spacecraft. Cornmeal agar with chloromycetin yielded the highest number of fungal colonies, although not always significantly higher than Mycophil agar with chloromycetin or TSA spread plates. Cornmeal agar with chloromycetin also gave the best qualitative representation of fungi on the spacecraft, recovering 68% of the genera found from all media. This medium yielded 10 times the number of fungal colonies and 3 times the number of genera found on TSA pour plates as currently used for spacecraft assay.

  17. Development of novel Alicyclobacillus spp. isolation medium.

    Science.gov (United States)

    Chang, S; Kang, D-H

    2005-01-01

    To develop a new isolation medium with higher recovery rates of Alicyclobacillus spp. SK agar was developed with optimized incubation temperature, pH, acidulant, Tween 80 concentration and divalent cation addition. Results indicate that detection of Alicyclobacillus spp. by SK agar was significantly higher (P > 0.05) than those obtained by K agar, orange serum agar, and potato dextrose agar. Current media used for Alicyclobacillus spp. isolation still resulted in high numbers of false negative products. The sensitivity of SK agar to Alicyclobacillus spp. allows detection of low numbers of Alicyclobacillus spp. and also provides a more higher isolation results compared with currently used media. SK agar will be useful to the fruit juice industry to obtain more accurate numbers of contaminant Alicyclobacillus spp. With this media, false negative samples can be reduced, and the likelihood of exported products being rejected can be greatly reduced.

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

    DEFF Research Database (Denmark)

    Dalsgaard, Inger

    2001-01-01

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

  19. Role of pH in oxidase variability of Aeromonas hydrophila.

    OpenAIRE

    Hunt, L K; Overman, T L; Otero, R B

    1981-01-01

    Some strains of Aeromonas hydrophila may be oxidase negative or only weakly oxidase positive by the Kovacs method taken from the surface of a differential medium, such as MacConkey agar. Six strains of A. hydrophila, two oxidase variable, one oxidase constant, and three weakly oxidase positive on MacConkey agar, were studied to determine the cause of oxidase variability. The bacteriostatic dyes in MacConkey agar were considered possible inhibitors of the oxidase reaction. The concentration of...

  20. Mycoflora of Soybeans Used for Meju Fermentation

    OpenAIRE

    Kim, Dae-Ho; Kim, Seon-Hwa; Kwon, Soon-Wo; Lee, Jong-Kyu; Hong, Seung-Beom

    2013-01-01

    Diverse fungi are present in Korean traditional meju and they are known to play an important role in fermented soybean products. To determine the origin of the fungi in meju, we examined the mycoflora of soybeans from 10 traditional meju factories. The samples were untreated or treated with sodium hypochlorite, and placed on malt extract agar (MEA), dichloran 18% glycerol agar (DG18), and dichloran rose bengal chloramphenicol agar (DRBC) medium. A total of 794 fungal strains were isolated and...

  1. Biopreservative activity of lactic acid bacteria on suya produced from ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... MRS (pH 5.5) for LAB, potato dextrose agar (PDA) for yeast/mould,. MacConkey agar for coliforms and mannitol salt agar for Staphylo- coccus. The cultures were incubated for 48 h with the exception of yeast and mould (72 h). For FFA determination 5 g of each suya sample was comminuted and the lipid ...

  2. Comparison of 2 chromogenic media for the detection of extended-spectrum β-lactamase producing Enterobacteriaceae stool carriage in nursing home residents.

    Science.gov (United States)

    Blane, Beth; Brodrick, Hayley J; Gouliouris, Theodore; Ambridge, Kirsty E; Kidney, Angela D; Ludden, Catherine M; Limmathurotsakul, Direk; Török, M Estée; Peacock, Sharon J

    2016-03-01

    ChromID ESBL agar and Brilliance ESBL agar were compared for the isolation of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae from 298 stools. These had comparable sensitivity and selectivity for the 116 positive samples. Pre-enrichment with cefpodoxime and extending incubation to 48 hours after direct plating both significantly increased sensitivity but reduced selectivity of both agars. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Tularemia: Current Diagnosis and Treatment Options

    Science.gov (United States)

    2008-04-01

    for growing F. tularensis, which include cysteine blood agar, Thayer–Martin agar and cysteine heart agar with 9% heated sheep red blood cells (CHAB...SL et al. An outbreak of primary pneumonic tularemia on Martha’s Vineyard . N. Engl. J. Med. 345, 1601–1606 (2001). 86 Feldman KA, Stiles-Enos D...Julian K et al. Tularemia on Martha’s Vineyard : seroprevalence and occupational risk. Emerg. Infect. Dis. 9, 350–354 (2003). 87 Christensen DR

  4. The Bangladeshi Agarwood Industry: Development Barriers and a Potential Way Forward

    OpenAIRE

    Md. Joynal Abdin

    2014-01-01

    Agarwood (which has various names around the Asia and Pacific region) is one of the most expensive non-timber wood products of the world. Bangladesh is producing three major products namely agar-wood, agar-oil and agar dust. It has many uses in the cosmetics (especially perfume) and medicine sectors. Agarwood has traditional, religious moreover cultural uses in different parts of the world. In addition to various Asian countries, agarwood has a long history in Bangladesh, especially in Moulvi...

  5. DEVELOPMENT AND EVALUATION OF A SELECTIVE AND INDICATIVE MEDIUM FOR ISOLATION OF ACTINOBACILLUS-PLEUROPNEUMONIAE FROM TONSILS

    DEFF Research Database (Denmark)

    Jakobsen, Marianne; Nielsen, Jens

    1995-01-01

    In order to isolate ActinobacillIus pleuropneumoniae from mixed bacterial flora a selective and indicative medium was developed. The optimal concentrations of antibiotics were determined for selective chocolate agar (S-TSA) and selective blood agar (S-MBA) using a set of 25 strains of A. pleuropn......In order to isolate ActinobacillIus pleuropneumoniae from mixed bacterial flora a selective and indicative medium was developed. The optimal concentrations of antibiotics were determined for selective chocolate agar (S-TSA) and selective blood agar (S-MBA) using a set of 25 strains of A...

  6. Variabilidad intraespecífica de cepas de Phytophthora palmivora Butler (Butler) aisladas de plantaciones de aguacatero (Persea americana Mill.) en Cuba

    OpenAIRE

    Machado, Maylen; Peña-Marey, Mabel; Alvarez, Alba; Díaz, Adriana; Zamora, Victoria; Coto, Orlando

    2013-01-01

    Se utilizaron en el estudio ocho cepas de Phytophthora palmivora Butler (Butler) obtenidas de jardines de aguacateros de la región occidental de Cuba, y se describieron los patrones de crecimientos de las colonias en medio agar papa dextrosa (PDA), agar zanahoria (AZ), agar jugo vegetal V8 (AV8) y agar malta (AM), así como los tipos de esporangios presentes. Se evaluó la variabilidad intraespecífica de los aislamientos en base a las dimensiones de los esporangios y de sus papilas. Las cepas m...

  7. [Viability of nematophagous fungi Arthrobotrys robusta, Duddingtonia flagrans and Monacrosporium thaumasium after sporulation in different culture media].

    Science.gov (United States)

    Maciel, Alessandro S; de Araujo, Jackson V; Campos, Artur K

    2006-01-01

    Due to the shortage of studies that indicate the culture mediums that optimize the sporulation of namatophagous fungi for use in researche, the sporulation of the fungal isolates A. robusta (I31), D. flagrans (CG768) and M. thaumasium (NF34A) was evaluated in laboratorial conditions for 10 days in the means water-agar 2% (WA 2%), potato-dextrose-agar 2% (PDA 2%), corn-meal-agar 2% (CMA 2%) and yeast-phosphate-sulphate-sucrose-agar (YPSSA). The largest conidia production (P BDA 2% while in the isolates I31 and NF34A produced larger conidia number in YPSSA (P 0.05).

  8. Propuesta de medio de cultivo para el estudio de Phytophthora Nicotianae Breda de Haan

    OpenAIRE

    Vaillant Flores, Daymara I; González García, Marleny; Ramírez Ochoa, Rebeca

    2013-01-01

    El género Phytophthora representa un grupo difícil de aislar y conservar. Por lo que se han desarrollado varios medios de cultivo para su estudio. Se propone al medio Agar-tabaco como alternativa para el crecimiento y desarrollo de P. nicotianae. Para realizar este trabajo se emplearon dos cepas: Pp1 y Pp6 aislados de tabaco y piña respectivamente. Ambas se sembraron en discos en agar-tabaco, y se comparó con agar tomate y agar harina de maíz. Se determinó el crecimiento lineal del hongo, las...

  9. Morphological Variations in Conidia of Arthrobotrys oligospora on Different Media.

    Science.gov (United States)

    Singh, R K; Kumar, Niranjan; Singh, K P

    2005-06-01

    Most commonly occurring predacious fungus Arthrobotrys oligospora showed great variation in size and shape of conidia on some media. The formation of larger conidia was recorded on beef extract and nutrient agar media. The length of conidia in Richard's YPSS, Sabouraud's, PDA and corn meal agar media was of medium size while smaller conidia were produced on Czapek's, Jensen's, Martin's medium. Maximum width of conidia was recorded on YPSS medium followed by Sabouraud's medium. The average size of spores on nematode infested corn meal agar medium was slightly increased than those on corn meal agar medium.

  10. Effects of solid-medium type on routine identification of bacterial isolates by use of matrix-assisted laser desorption ionization-time of flight mass spectrometry.

    Science.gov (United States)

    Anderson, Neil W; Buchan, Blake W; Riebe, Katherine M; Parsons, Lauren N; Gnacinski, Stacy; Ledeboer, Nathan A

    2012-03-01

    Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is a rapid method for the identification of bacteria. Factors that may alter protein profiles, including growth conditions and presence of exogenous substances, could hinder identification. Bacterial isolates identified by conventional methods were grown on various media and identified using the MALDI Biotyper (Bruker Daltonics, Billerica, MA) using a direct smear method and an acid extraction method. Specimens included 23 Pseudomonas isolates grown on blood agar, Pseudocel (CET), and MacConkey agar (MAC); 20 Staphylococcus isolates grown on blood agar, colistin-nalidixic acid agar (CNA), and mannitol salt agar (MSA); and 25 enteric isolates grown on blood agar, xylose lysine deoxycholate agar (XLD), Hektoen enteric agar (HE), salmonella-shigella agar (SS), and MAC. For Pseudomonas spp., the identification rate to genus using the direct method was 83% from blood, 78% from MAC, and 94% from CET. For Staphylococcus isolates, the identification rate to genus using the direct method was 95% from blood, 75% from CNA, and 95% from MSA. For enteric isolates, the identification rate to genus using the direct method was 100% from blood, 100% from MAC, 100% from XLD, 92% from HE, and 87% from SS. Extraction enhanced identification rates. The direct method of MALDI-TOF analysis of bacteria from selective and differential media yields identifications of varied confidence. Notably, Staphylococci spp. from CNA exhibit low identification rates. Extraction enhances identification rates and is recommended for colonies from this medium.

  11. Different culture media containing methyldopa for melanin production by Cryptococcus species

    Directory of Open Access Journals (Sweden)

    Ralciane de Paula Menezes

    2011-10-01

    Full Text Available INTRODUCTION: Melanin production by species of Cryptococcus is widely used to characterize C. neoformans complex in mycology laboratories. This study aims to test the efficacy of methyldopa from pharmaceutical tablet as a substrate for melanin production, to compare the production of melanin using different agar base added with methyldopa, and to compare the melanin produced in those media with that produced in Niger seed agar and sunflower seed agar by C. neoformans, C. laurentii, and C. albidus. Two isolates of each species, C. neoformans, C. laurentii, and C. albidus, and one of Candida albicans were used to experimentally detect conditions for melanin production. METHODS: The following media were tested: Mueller-Hinton agar (MHA, brain and heart infusion agar (BHIA, blood agar base (BAB, and minimal medium agar (MMA, all added with methyldopa, and the media Niger seed agar (NSA and sunflower seed agar (SSA. RESULTS: All isolates grew in most of the culture media after 24h. Strains planted on media BAB and BHIA showed growth only after 48h. All isolates produced melanin in MMA, MHA, SSA, and NSA media. CONCLUSIONS: Methyldopa in the form pharmaceutical tablet can be used as a substrate for melanin production by Cryptococcus species; minimal medium plus methyldopa was more efficient than the BAB, MHA, and BHIA in the melanin production; and NSA and SSA, followed by MMA added with methyldopa, were more efficient than other media studied for melanin production by all strains studied.

  12. Evaluation of the ability of four ESBL-screening media to detect ESBL-producing Salmonella and Shigella.

    Science.gov (United States)

    Sturød, Kjersti; Dahle, Ulf R; Berg, Einar Sverre; Steinbakk, Martin; Wester, Astrid L

    2014-09-04

    The aim of this study was to compare the ability of four commercially available media for screening extended-spectrum beta-lactamase (ESBL) to detect and identify ESBL-producing Salmonella and Shigella in fecal samples. A total of 71 Salmonella- and 21 Shigella-isolates producing ESBL(A) and/or AmpC, were received at Norwegian Institute of Public Health between 2005 and 2012. The 92 isolates were mixed with fecal specimens and tested on four ESBL screening media; ChromID ESBL (BioMèrieux), Brilliance ESBL (Oxoid), BLSE agar (AES Chemunex) and CHROMagar ESBL (CHROMagar). The BLSE agar is a biplate consisting of two different agars. Brilliance and CHROMagar are supposed to suppress growth of AmpC-producing bacteria while ChromID and BLSE agar are intended to detect both ESBL(A) and AmpC. The total sensitivity (ESBL(A)+AmpC) with 95% confidence intervals after 24 hours of incubation were as follows: ChromID: 95% (90.4-99.6), Brilliance: 93% (87.6-98.4), BLSE agar (Drigalski): 99% (96.9-100), BLSE agar (MacConkey): 99% (96.9-100) and CHROMagar: 85% (77.5-92.5). The BLSE agar identified Salmonella and Shigella isolates as lactose-negative. The other agars based on chromogenic technology displayed Salmonella and Shigella flexneri isolates with colorless colonies (as expected). Shigella sonnei produced pink colonies, similar to the morphology described for E. coli. All four agar media were reliable in screening fecal samples for ESBL(A)-producing Salmonella and Shigella. However, only ChromID and BLSE agar gave reliable detection of AmpC-producing isolates. Identification of different bacterial species based on colony colour alone was not accurate for any of the four agars.

  13. Co-production of surfactin and a novel bacteriocin by Bacillus subtilis subsp. subtilis H4 isolated from bikalga, an African alkaline Hibiscus sabdariffa seed fermented condiment

    DEFF Research Database (Denmark)

    Compaore, C. S.; Nielsen, Dennis S.; Ouoba, L. I. I.

    2013-01-01

    inhibited in the agar spot assay while only Gram-positive pathogens were inhibited in the agar well diffusion assay. Cell free supernatants (CFS) of pure cultures of 3 B. subtilis subsp. subtilis (G2, H4 and F1) strains inhibited growth of Listeria monocytogenes, Micrococcus luteus, Staphylococcus aureus...

  14. PERANCANGAN PROTOTIPE BUCKET ELEVATOR

    OpenAIRE

    Dani Irawan

    2017-01-01

    Alat Pemindah Bahan merupakan salah satu peralatan yang digunakan untuk kegiatan sehari-hari pada proses keberlangsungan produksi di masyarakat. Agar peralatan tersebut tetap dapat berfungsi dengan baik masyarakat, maka perlu adanya tindakan rancang bangun prototype Bucket konveyor ini guna untuk membatu masyarakat agar lebih memahami betapa pentingnya alat mekanis. Metode Perancangan Prototipe Bucket Konveyor meliputi: Perancangan Desain, Perancangan Elemen Mesin Perancangan Biaya (biaya...

  15. Synthesis of quarternary ammonium salts with dithiocarbamate ...

    Indian Academy of Sciences (India)

    were taken from PDA (Potato Dextrose Agar) slants and spore suspension was made by addition of sterili- zed distilled water. The suspension was filtered through three layers of sterilized cheese cloth under aseptic con- ditions in order to remove agar bits and mycelium. Haemocytometer was used to get spore suspension.

  16. Analysis of Kenyan isolates of Fusarium solani f. sp. phaseoli from ...

    African Journals Online (AJOL)

    All the isolates showed high variability in aerial mycelial growth, mycelia texture, pigmentation (mycelia colour) when cultured on potato dextrose agar medium, and conidial measurements on Spezieller Nahrstoffarmer agar medium. Colonies were grouped into luxuriant, moderately luxuriant and scanty on aerial mycelial ...

  17. Incidence of pulmonary mycoses in patients with acquired ...

    African Journals Online (AJOL)

    Test and control samples were cultured on Sabouraud Dextrose Agar and Potato Dextrose Agar and incubated at 37 C and room temperatures respectively with daily observation for growth for 2 weeks. Cultural and morphological characteristics, KOH mount and Lactophenol Cotton Blue stainingwere used to identify ...

  18. Evaluation of conidia production and mycelial growth in solid culture ...

    African Journals Online (AJOL)

    FATIMAYALBERTO

    2012-10-02

    Oct 2, 2012 ... Yeast peptone dextrose agar (YPDA), Potato dextrose agar (PDA), to name a few (Kamp and Bidochka, 2002). Most of these present a media composition based on source of carbon and one nitrogen which generally vary between them and in the proportions in which they are presented as well as in its ...

  19. Morphological Characterization and Determination of Aflatoxin-Production Potentials of Aspergillus flavus Isolated from Maize and Soil in Kenya

    Directory of Open Access Journals (Sweden)

    Matome Gabriel Thathana

    2017-09-01

    Full Text Available This study aimed at morphologically identifying Aspergillus flavus in soil and maize and at determining their aflatoxin-producing potentials. Five hundred and fourteen isolates obtained from maize and soil in Kenya were cultivated on Czapeck Dox Agar, Malt Extract Agar, Sabouraud Dextrose Agar, Potato Dextrose Agar, and Rose-Bengal Chloramphenicol Agar. Isolates were identified using macro-morphological characteristics. Micromorphological characteristics were determined using slide cultures. Aflatoxin production was determined by direct visual determination of the UV fluorescence of colonies on Coconut Agar Medium, Yeast Extract Sucrose agar, and Yeast Extract Cyclodextrin Sodium Deoxycholate agar and by Thin Layer Chromatography. Forty-three presumptive A. flavus isolates were identified; aflatoxin was detected in 23% of the isolates by UV fluorescence screening and in 30% by Thin-Layer Chromatography (TLC. The aflatoxins produced were: aflatoxin B1 (AFB1, aflatoxin B2 (AFB2, and aflatoxin G1 (AFG1; some isolates produced only AFB1, whereas others produced either AFB1 and AFB2 or AFB1 and AFG1. The highest incidence of A. flavus (63% and aflatoxin production (28% was recorded in samples from Makueni District. Isolates from Uasin Gishu (21% and Nyeri (5% were non-aflatoxigenic. Bungoma District recorded 11% positive isolates of which 2% were aflatoxin producers. The occurrence of aflatoxin-producing A. flavus emphasises the need for measures to eliminate their presence in food crops.

  20. original article candida species amongst pregnant women in benin

    African Journals Online (AJOL)

    Dr Oboro VO

    was used to streak Sabouraud Dextrose. Agar SDA (Oxoid, England) plates containing 0.5ml Chloramphenicol. (500mg,Pfizer) and incubated at 370C in triplicates. Uninoculated plain agar plates served as control for the inoculated ones. Discrete yeast colonies were subcultured on fresh SDA slants in. McCarthney bottles ...

  1. In vitro effect of some quinolone antibiotics on strains of ...

    African Journals Online (AJOL)

    A total of 30 different strains of Staphylococcus aureus were isolated from some selected wards of Madonna University Teaching Hospital (MUTH), Elele, Nigeria, using blood agar and nutrient agar. All the isolates were subjected to some selected quinolones (ciprofloxacin, pefloxacin, ofloxacin, norfloxcin and sparfloxacin) ...

  2. Resistance patterns of Staphylococcus aureus and Pseudomonas ...

    African Journals Online (AJOL)

    Two hundred (200) strains of S. aureus and P. aeruginosa were isolated from clinical samples collected from patients in Murtala Muhammad Specialist Hospital and Infectious Diseases Hospital, Kano. The confirmed isolates were tested for resistance to quinolones by the agar disk diffusion susceptibility test and the agar ...

  3. (melanin) production in Streptomyces

    African Journals Online (AJOL)

    GRACE

    Nine strains among 180 Streptomyces isolates produce a diffusible dark brown pigment on both peptone-yeast extract agar and synthetic tyrosine-agar. They also show the positive reaction to L- tyrosine or L-dopa substrates. The pigment has been referred to be as merely as dark brown water- soluble pigment, as melanoid ...

  4. Seperation, identification and analysis of pigment (melanin ...

    African Journals Online (AJOL)

    Nine strains among 180 Streptomyces isolates produce a diffusible dark brown pigment on both peptone-yeast extract agar and synthetic tyrosine-agar. They also show the positive reaction to Ltyrosine or L-dopa substrates. The pigment has been referred to be as merely as dark brown watersoluble pigment, as melanoid or ...

  5. Schematic Method for Effective Identification of Anaerobes from ...

    African Journals Online (AJOL)

    They were inoculated into two compounded media; Neomycin Blood Agar (NBA) and Neomycin Plasma Agar (NPA) incubated anaerobically at 37oC for (24-48) hours. Isolated anaerobes were gram-stained and tested using discs impregnated with antibiotics, bile salts and dyes, carbohydrate fermentation and other ...

  6. A short communication-Enhancement of growth of fungi commonly ...

    African Journals Online (AJOL)

    Four natural agar media designed for the first time from peel and juice of both pure and hybrid passion fruits grown in Uganda were used to compare growth of 22 isolates of 18 species of the most commonly associated mycobiota with passion fruits. The majority of isolates tested was enhanced on both juice agar media ...

  7. 48 CFR 401.403 - Individual deviations.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Individual deviations. 401... AGRICULTURE ACQUISITION REGULATION SYSTEM Deviations From the FAR and AGAR 401.403 Individual deviations. In individual cases, deviations from either the FAR or the AGAR will be authorized only when essential to effect...

  8. Growth rate and trapping efficacy of nematode-trapping fungi under constant and fluctuating temperatures

    DEFF Research Database (Denmark)

    Fernandez, A.S.; Larsen, M.; Wolstrup, J.

    1999-01-01

    The effect of temperature on radial growth and predatory activity of different isolates of nematode-trapping fungi was assessed. Four isolates of Duddingtonia flagrans and one isolate of Arthrobotrys oligospora were inoculated on petri dishes containing either cornmeal agar (CMA) or faecal agar...

  9. ORIGINAL ARTICLES Helicobacter pylori: Prevalence and antibiotic ...

    African Journals Online (AJOL)

    were added to culture media (Colombia blood agar and brain- heart infusion agar) ... thawed at room temperature, transferred to a water bath at. 56°C and stirred ... and gently mixed with a 5 ml aliquot of the inactivated FBS. Aliquots of 500 µl ...

  10. Evaluation for sterility of four crystalloid solutions used in ...

    African Journals Online (AJOL)

    Pre and post preservation, a loop-full of each solution was cultured on freshly prepared two general purpose media (Blood and nutrient agar) and one selective medium (MacConkey agar). They were incubated at 37 0C for 48 hours after which they were examined for bacterial growth. Histological studies of the preserved ...

  11. Infectious bursal disease outbreak in 19-week old commercial ...

    African Journals Online (AJOL)

    Necropsy revealed a markedly enlarged, oedematous and haemorrhagic bursa. Histopathologic findings including lympho-cytolysis and oedema were characteristic of an acute bursitis and a positive agar-gel precipitation test were used to confirm the diagnosis of Infectious bursal disease. Keywords: Agar gel precipitation, ...

  12. Effect of Aqueous Extract of Acacia nilotica on Microbial and Castor ...

    African Journals Online (AJOL)

    Prof. Ogunji

    antimicrobial activity (MIC): Mueller Hilton Agar was prepared according to manufacturer's direction. One mill (1ml) of the standardized test organisms was inoculated into the molten agar poured into sterile Petri-dishes which was allowed to get at room temperature. Eight. Millimetres (8mm) diameter sterile cork borer.

  13. Evaluation of anti-bacterial properties of ethanol extract of Ficus ...

    African Journals Online (AJOL)

    Yomi

    2012-02-23

    Feb 23, 2012 ... pneumoniae were incubated in agar plates after serial dilutions of the extract were added in wells made in the agar and incubated for 24 h at 37°C. Thereafter, zones of inhibition (in mm) around the wells were measured. The same organisms were tested for sensitivity against standard antibiotics using disk.

  14. Correlation between mastitis occurrence and the count of microorganisms in bulk raw milk of bovine dairy herds in four selective culture media.

    Science.gov (United States)

    Souto, Luís I M; Minagawa, Clarice Y; Telles, Evelise O; Garbuglio, Márcio A; Amaku, Marcos; Melville, Priscilla A; Dias, Ricardo A; Sakata, Sonia T; Benites, Nilson R

    2010-02-01

    Milk is the normal secretion of the mammary gland, practically free of colostrum and obtained by the complete milking of one or more healthy animals. Mastitis is an inflammatory process of the mammary gland and it may cause alterations in the milk. The present work aimed to verify whether it is possible, by means of the counts of microorganism in the bulk raw milk in four selective culture media, to establish a correlation with the occurrence of mastitis and therefore, to monitor this disease in bovine dairy herds. The following selective culture media were used: KF Streptococcus Agar, Edwards Agar, Baird-Parker Agar, Blood Agar plus potassium tellurite. Spearman's correlation coefficient was calculated in order to compare the occurrence of mastitis (percentage) in each herd with respective selective culture media counts of microorganisms in bulk raw milk. Thirty-six possibilities were analysed (Tamis and CMT-positive rates were compared with the log-transformed count in four selective culture media) and there was a negative correlation between Tamis 3 and the Baird-Parker Agar plate count. The total results of microbiological tests showed that there were three correlations of the counts in selective culture media. Fifty-two possibilities were analysed and there was a negative correlation between no-bacterial-growth mastitis rates and log10 of KF Streptoccocus Agar plate count and there were two positive correlations between coagulase-positive staphylococci and log10 of Baird-Parker Agar plate count and Blood Agar plus potassium tellurite plate count.

  15. Prey-predator dynamics in communities of culturable soil bacteria and protozoa: differential effects of mercury

    DEFF Research Database (Denmark)

    Holtze, M. S.; Ekelund, F.; Rasmussen, Lasse Dam

    2003-01-01

    CFUs on the general medium 1/100 tryptic soy agar (TSA) were significantly decreased when the soil had been amended with Hg. In contrast, no effect was seen on the number of CFUs on the Pseudomonas-specific medium Gould's S1 agar. Protozoan numbers estimated by the most probable number (MPN) method...

  16. False identification of other microorganisms as Staphylococcus ...

    African Journals Online (AJOL)

    Methods: 507 microorganisms which have been previously identified as S. aureus in 8 States in Southern Nigeria through characteristic morphology on blood agar, Gram staining, growth and fermentation on Mannitol Salt Agar and coagulase formation were collected. All the isolates were identified in this study through ...

  17. Effect of alternating and direct currents on Pseudomonas ...

    African Journals Online (AJOL)

    The test media were Muller-Hinton agar and eosin methylene blue (EMB) agar. In this research Pseudomonas aeruginosa which was isolated from patients wounds was examined with levels of alternating and direct current (AC and DC) electrical stimulation (1.5V, 3.5V, 5.5V and 10V) to see if these currents could inhibit P.

  18. Evaluation of Two Supplemented Culture Media for Long-Term, Room-Temperature Preservation of Streptococcus pneumoniae Strains

    Directory of Open Access Journals (Sweden)

    Beatriz Quintero Moreno

    2017-01-01

    Full Text Available Objective. To produce two supplemented agar types in order to store pneumococci for several months at room temperature. Methods. Todd-Hewitt/Hemoglobin/Yeast/Charcoal/Agar (TH-HYC and Todd-Hewitt/Skim-Milk/Yeast/Charcoal/Agar (TH-SYC were used to prepare two supplemented agar types. Nineteen pneumococci isolated from patients or asymptomatic carriers displaying diverse serotypes and multilocus sequence types (MLST were subcultured and stored onto supplemented agar types, in four different tests, at room temperature. Findings. At the end of all tests (4–6 months all noncontaminated subcultures were viable and maintained all phenotypic characteristics. Survival-time curves revealed a slow decrease of viable CFU over time on agar types, but at the end the number of viable CFU was satisfactory (≥2+ of growth. Decreasing of CFU was significantly higher for clinical versus nasopharyngeal isolates. Subcultures contamination rates were 6.25% and 14.58% after 2 and 6 months of storage, respectively. Conclusion. TH-HYC and TH-SYC agar types allowed the viability of pneumococci with several serotypes, MLST, and genetic profiles, after 6 months of storage at room temperature. We consider that these agar types are a valid alternative to preserve pneumococci over an extended period, especially when methods as cryopreservation or lyophilization are not available, and are useful for transporting strains between laboratories.

  19. 337-IJBCS-Article-Dr Temgoua Emile

    African Journals Online (AJOL)

    Dr Gatsing

    Faecal coliform and faecal streptococci: for the coliforms, the lactosed agar with TTC and tergitol were used as culture medium, while the agar with bile, esculine and sodium acid were used for ..... and techniques (structure and position of sanitation device) of non-polluted points, which prevent transfer of pollutants into the.

  20. Browse Title Index

    African Journals Online (AJOL)

    Vol 10, No 4 (2014), Qualité physicochimique et bactériologique de trois ... Recherche des facteurs les plus influents sur le rendement et la qualité de l'agar- agar de la rhodophycée Gelidium spinosum (S.G. Gmelin) P.C. Silva, Abstract PDF.

  1. ( Allium sativum ) on Salmonella typhi infection, gastrointestinal flora ...

    African Journals Online (AJOL)

    The effect of consumption of garlic (Allium sativum) in treating Salmonella typhi infection and on the gastrointestinal flora and hematological parameters of rats was investigated. Crude garlic extract inhibited the growth of S. typhi on agar plate with a zone of inhibition averaging 23.8 mm in diameter using the agar diffusion ...

  2. Characterization of anti-listerial lactic acid bacteria isolated from Thai fermented fish products

    DEFF Research Database (Denmark)

    Østergaard, Anya; Embarek, Peter Karim Ben; Wedell-Neergaard, C.

    1998-01-01

    Thai fermented fish products were screened for lactic acid bacteria capable of inhibiting Listeria sp. (Listeria innocua). Of 4150 assumed lactic acid bacteria colonies from MRS agar plates that were screened by an agar-overlay method 58 (1.4%) were positive. Forty four of these strains were...

  3. Time to first fracture affects sweetness of gels

    NARCIS (Netherlands)

    Sala, G.; Stieger, M.A.

    2013-01-01

    The aim of this study was to investigate the influence of the breakdown behaviour on sweetness intensity of gelled model foods. Emulsion-filled gelatine/agar gels varying mainly in fracture strain (eF) were used. The fracture strain was modified by changing either the ratio between gelatine and agar

  4. A comparative study of sampling techniques for monitoring carcass contamination

    NARCIS (Netherlands)

    Snijders, J.M.A.; Janssen, M.H.W.; Gerats, G.E.; Corstiaensen, G.P.

    1984-01-01

    Four bacteriological sampling techniques i.e. the excision, double swab, agar contract and modified agar contact techniques were compared by sampling pig carcasses before and after chilling. As well as assessing the advantages and disadvantages of the techniques particular attention was paid to

  5. Water quality effects of harbour activities assessed with integrated ...

    African Journals Online (AJOL)

    moes2

    Ecological tools were developed to study the water quality in Cochin harbour, a complex aquatic ecosystems ... contamination index is another important factor to assess ... Nutrient agar with the ... yeast extract 3.0 g; beef extract 2.0 g; agar 15.0 g; aged sea water .... ability to be incorporated into food chains (Kishe and.

  6. A fatal pulmonary infection by Nocardia brasiliensis.

    Science.gov (United States)

    Wadhwa, V; Rai, S; Kharbanda, P; Kabra, S; Gur, R; Sharma, V K

    2006-01-01

    The reported case is of primary pulmonary nocardiosis, caused by Nocardia brasiliensis, in a immunocompromised patient, which ended fatally despite appropriate treatment. The partially acid fast filamentous bacterium was predominant on direct examination of the sputum. It was cultured on blood agar, MacConkey agar and by paraffin baiting technique. The bacterium was resistant to cotrimoxazole, the drug of choice for nocardiosis.

  7. Olaitan and Muhammad (12)

    African Journals Online (AJOL)

    DELL

    various selective media such as MacConkey agar, mannitol salt agar .... Yemen. Journal of Pharmacy and. Pharmacognosy Research.3(1), 6 – 12. Amira, E. E., Abdel, M. E. S. ... of Natural and Social Sciences.2: 54 – 59. Ferreria, A. C., Morais ...

  8. Felege Hiwot Referral Hospital, North West

    African Journals Online (AJOL)

    Rapid spread of resistant microbes affected the effectiveness of antimicrobials creating worldwide problem (1). The condition is serious in developing countries owing to irrational prescription ... Standard operation procedures were checked for laboratory ... Sheep's blood, chocolate agar, mannitol salt agar and. MacConkey ...

  9. Original Article

    African Journals Online (AJOL)

    2013-06-22

    Jun 22, 2013 ... onto blood, MacConkey, and Mannitol salt agar plates and incubated for 18-24 hrs at ... standard 0.5 and spread over the surface of. Mueller-Hinton agar. Antibiotic .... Table 3. Comparison of infection rate in emergency and elective Caesarean Operation in patients at MMSH, Kano. X2 = 8.1 df = 1 p<0.004.

  10. Identification and antibiotic sensitivity test of bacteria from stools of ...

    African Journals Online (AJOL)

    One hundred and fifty stool samples from 65 female and 85 male patients with acute diarrhoea from the Central Hospital, Agbor (Nigeria) were examined to ascertain the likelihood of cholera outbreak in Agbor. The samples were preserved in Carey-Blair semi-solid medium, inoculated directly on blood agar, McConkey agar ...

  11. In vitro dilutions of thioridaxine with potential to enhance antibiotic ...

    African Journals Online (AJOL)

    Gram staining, catalase test and coagulase test were done on the resulting colonies to further confirm the strains as S. aureus. Antibiotic susceptibility test was done by agar disc diffusion method using sterile Mueller- Hinton agar plates before and after treatment with laboratory dilutions of thioridaxine. S. aureus strains 1, ...

  12. Characteristics and Sampling Efficiencies of Two Impactor Bioaerosol Samplers: MAS-100(Registered) (Microbial Air Monitoring System) and Single-Stage Andersen Viable Microbial Samplers

    National Research Council Canada - National Science Library

    Hottell, K

    2004-01-01

    .... A petri dish with agar is used as the impaction surface for these samplers. The MAS-l00 is a single-stage impactor that aspirates air through a 400-hole perforated entry plate onto an agar plate at an airflow rate of 100 L/min...

  13. 3-Substituted Indole Inhibitors Against Francisella tularensis FabI Identified by Structure-Based Virtual Screening

    Science.gov (United States)

    2013-07-01

    and incubation at 35 ± 2 °C on agar plates using starting samples removed from freezer stocks of each strain. Chocolate agar was used for F. tularensis...potential massive use of antimicrobial agents as prophylaxis or therapy of a bioterrorist attack. Clin. Microbiol. Infect. 2002, 8, 534−539. (11) Loveless, B

  14. Mastitis pathogens prevalent in dairy cattle at Magadu farm ...

    African Journals Online (AJOL)

    This study was carried out to determine the prevalence of mastitis pathogens at the Magadu Dairy Farm, Sokoine University of Agriculture. A total of 19 milk samples were collected and cultured on blood agar and MacConkey agar followed by identification of bacteria colonies and cells using standard laboratory techniques.

  15. A Survey of Bacterial and Fungal Oppurtunistic Infections among ...

    African Journals Online (AJOL)

    The bacterial pathogens were isolated using Blood and Chocolate agar plates and identified biochemically except the Acid Fast Bacilli (AFB) which was tested in all the HIV positive samples by Ziehl Neelson staining technique. The fungal pathogens were isolated using Sabouraud Dextrose Agar (SDA) with antibiotics and ...

  16. The Prevalence and Antibiogram of Esherichia Coli from Clinical ...

    African Journals Online (AJOL)

    Specimens of wounds, aspirates and high vagina were cultured on chocolate, blood and McConkey and Eosin methylene blue agars. Specimens on blood agar were incubated both aerobically and anaerobically for 24hrs. Isolates were identified by their colonial morphology and biochemical reactions and tested for ...

  17. Video-supported analysis of Beggiatoa filament growth, breakage, and movement

    DEFF Research Database (Denmark)

    Kamp, Anja; Røy, Hans; Schulz-Vogt, Heide N.

    2008-01-01

    A marine Beggiatoa sp. was cultured in semi-solid agar with opposing oxygen-sulfide gradients. Growth pattern, breakage of filaments for multiplication, and movement directions of Beggiatoa filaments in the transparent agar were investigated by time-lapse video recording. The initial doubling time...

  18. Health and safety conditions of building maintenance sites in Nigeria

    African Journals Online (AJOL)

    To identify the microorganisms, bulk samples were collected on timber buildings classified as maintenance sites over the country and then identify the microorganisms available using the cultivation technique. Eight hundred and fifty nutrient and Sabouraud dextrose agar dishes were prepared. The nutrient agar dishes were ...

  19. Media preparation and bacteriological tools.

    Science.gov (United States)

    Elbing, Karen; Brent, Roger

    2002-08-01

    Recipes are provided in this unit for minimal liquid media, rich liquid media, solid media, top agar, and stab agar. Also included are descriptions and useful information about tools used with growth media such as inoculating loops, sterile toothpicks and spreaders.

  20. Seçici Özellikteki Farklı Besiyerlerinin bazı Mayaların Meyveli Yoğurttan Geri Kazanımları Amacı ile Karşılaştırılmaları (İngilizce)

    OpenAIRE

    Şule Şenses Ergül; Z. Yeşim Özbaş

    2015-01-01

    Bu çalışmada, yapay olarak aşılanan meyveli yoğurt örneklerinden bazı mayaların izolasyonu için kullanılabilecek farklı besiyerleri karşılaştırılmıştır. Bu amaçla, kontrol besiyeri olarak malt extract agar ve beş farklı seçici besiyeri kullanılmıştır. Bu besiyerleri; malt extract yeast extract %50 fructose glucose agar, malt extract yeast extract %40 sucrose agar, malt extract yeast extract glucose %0.8 peptone agar, malt extract yeast extract glucose %0.1 peptone agar and potato dextrose %50...

  1. Evaluation of Bruker Biotyper and Vitek MS for the identification of Candida tropicalis on different solid culture media.

    Science.gov (United States)

    Wang, He; Li, Ying; Fan, Xin; Chiueh, Tzong-Shi; Xu, Ying-Chun; Hsueh, Po-Ren

    2017-11-11

    The aim of this study was to investigate the performance of the Bruker Biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and Vitek MS systems for identification of genetically-confirmed blood isolates of Candida tropicalis that had been grown on several types of culture media commonly used for primary fungal isolation. Isolates included 105 from the National China Hospital Invasive Fungal Surveillance Net program (CHIF-NET) and 120 from National Taiwan University Hospital (NTUH). Culture media tested for CHIF-NET isolates included trypticase soy agar supplemented with 5% sheep blood (BAP), Sabouraud dextrose agar (SDA-C), CHROMagar, China blue agar (CBA), chocolate agar supplemented with vancomycin (CAP-VA), and MacConkey agar (MAC). Culture media used for NTUH isolates included BAP, SDA, CHROMagar, eosin methylene blue (EMB), inhibitory mold agar (IMA), Mycosel agar, and cornmeal agar (CMA). The Bruker Biotyper correctly identified all CHIF-NET isolates to the species level on all six agar media tested and correctly identified the majority of NTUH isolates with the exception of isolates grown on SDA (85.8%) and CMA (52.5%). The Vitek MS system correctly identified all CHIF-NET isolates to the species level with the exception of isolates grown on CHROMagar (84.8%), and correctly identified the majority of NTUH isolates with the exception of isolates grown on SDA (51.7%), Mycosel agar (57.5%), and CMA (9.2%) for NTUH isolates. Clinical microbiologists should be aware that different culture media can affect the performance of the Bruker Biotyper MALDI-TOF MS and Vitek MS systems in identifying C. tropicalis. Copyright © 2017. Published by Elsevier B.V.

  2. Application of Fourier Transform Infrared (FTIR) Spectroscopy for Rapid Detection of Fumonisin B2 in Raisins.

    Science.gov (United States)

    Heperkan, Dilek; Gökmen, Ece

    2016-07-01

    The aim of this study was to investigate the potential use of FTIR spectroscopy as a rapid screening method to detect fumonisin produced by Aspergillus niger. A. niger spore suspensions isolated from raisins were inoculated in Petri dishes prepared with sultana raisin or black raisin extracts containing agar and malt extract agar (MEA). After 9 days of incubation at 25°C, fumonisin B2 (FB2) production on each agar plate was determined by subjecting the agar plugs to IR spectroscopy. The presence of amino group (at 1636-1639 cm(-1)) was especially indicative of fumonisin production in MEA and the raisin extracts containing agar. The results were confirmed by HPLC analysis of the agar sample extracts after immunoaffinity column cleanup. It was determined that A. niger produced more FB2 in sultana raisins than in MEA, with no FB2 being produced in black raisin extract agar. This study demonstrated that proper sample preparation procedure followed by FTIR analysis is a useful technique for identifying toxigenic molds and their mycotoxin production in agricultural commodities.

  3. Performance of chromogenic media for Candida in rapid presumptive identification of Candida species from clinical materials.

    Science.gov (United States)

    Pravin Charles, M V; Kali, Arunava; Joseph, Noyal Mariya

    2015-06-01

    In perspective of the worldwide increase in a number of immunocompromised patients, the need for identification of Candida species has become a major concern. The development of chromogenic differential media, introduced recently, facilitate rapid speciation. However, it can be employed for routine mycology workup only after an exhaustive evaluation of its benefit and cost effectiveness. This study was undertaken to evaluate the benefit and cost effectiveness of chromogenic media for speciation of Candida clinical isolates. Sputum samples of 382 patients were screened for the presence of Candida spp. by Gram stain and culture on sabouraud dextrose agar. Candida species were identified using Gram stain morphology, germ tube formation, cornmeal agar with Tween-80, sugar fermentation tests and morphology on HiCrome Candida differential agar. All the Candida isolates were inoculated on HiCrome Candida agar (HiMedia, Mumbai, India). The sensitivity and specificity of HiCrome agar for identification of Candida albicans were 90% and 96.42%, respectively whereas sensitivity and specificity of carbohydrate fermentation test were 86.67% and 74.07%, respectively. Sensitivity and specificity values of HiCrome agar for detection of C. albicans, Candida parapsilosis and Candida glabrata were above 90%. We found HiCrome agar has high sensitivity and specificity comparable to that of the conventional method. In addition, use of this differential media could significantly cut down the turnaround time as well as cost of sample processing.

  4. A xyloglucan from seeds of the native Brazilian species Hymenaea courbaril for micropropagation of Marubakaido and Jonagored apples.

    Science.gov (United States)

    Lima-Nishimura, N; Quoirin, M; Naddaf, Y G; Wilhelm, H M; Ribas, L L F; Sierakowski, M-R

    2003-01-01

    Xyloglucan was extracted from seeds of Hymenaea courbaril and mixed with agar to prepare a solid culture medium used for micropropagation of the Marubakaido apple rootstock (Malus prunifolia Borkh) and cv. Jonagored (Malus domestica). The performance on gels created from a blend of 0.4%agar and 0.2% xyloglucan (w/v) was compared with that on media gelled with a standard concentration 0.6% (w/v) of agar. The growth of shoots and the multiplication rate were higher on the modified culture medium than on the agar-gelled medium. The occurrence of hyperhydric shoots was lower on the modified medium. In the absence of auxin, shoot rooting reached 70% (Marubakaido) and 66% (Jonagored) on the agar-xyloglucan medium and 6.7% and 10.4%, respectively, on the agar medium. When 0.25 microM indole-3-butyric acid (IBA) was added to both media, the modified medium gave better results in terms of rooting percentage and quality of roots than the agar-gelled medium.

  5. Evaluation of standard and modified M-FC, MacConkey, and Teepol media for membrane filtration counting of fecal coliforms in water.

    Science.gov (United States)

    Grabow, W O; Hilner, C A; Coubrough, P

    1981-08-01

    MacConkey agar, standard M-FC agar, M-FC agar without rosolic acid, M-FC agar with a resuscitation top layer, Teepol agar, and pads saturated with Teepol broth, were evaluated as growth media for membrane filtration counting of fecal coliform bacteria in water. In comparative tests on 312 samples of water from a wide variety of sources, including chlorinated effluents, M-FC agar without rosolic acid proved the medium of choice because it generally yielded the highest counts, was readily obtainable, easy to prepare and handle, and yielded clearly recognizable fecal coliform colonies. Identification of 1,139 fecal coliform isolates showed that fecal coliform tests cannot be used to enumerate Escherichia coli because the incidence of E. coli among fecal coliforms varied from an average of 51% for river water to 93% for an activated sludge effluent after chlorination. The incidence of Klebsiella pneumoniae among fecal coliforms varied from an average of 4% for the activated sludge effluent after chlorination to 32% for the river water. The advantages of a standard membrane filtration procedure for routine counting of fecal coliforms in water using M-FC agar without rosolic acid as growth medium, in the absence of preincubation or resuscitation steps, are outlined.

  6. Transcriptome profiling of sulfate deprivation responses in two agarophytes Gracilaria changii and Gracilaria salicornia (Rhodophyta).

    Science.gov (United States)

    Lee, Wei-Kang; Namasivayam, Parameswari; Ong Abdullah, Janna; Ho, Chai-Ling

    2017-04-24

    Seaweeds survive in marine waters with high sulfate concentration compared to those living at freshwater habitats. The cell wall polymer of Gracilaria spp. which supplies more than 50% of the world agar is heavily sulfated. Since sulfation reduces the agar quality, it is interesting to investigate the effects of sulfate deprivation on the sulfate contents of seaweed and agar, as well as the metabolic pathways of these seaweeds. In this study, two agarophytes G. changii and G. salicornia were treated under sulfate deprivation for 5 days. The sulfate contents in the seaweed/agar were generally lower in sulfate-deprivated samples compared to those in the controls, but the differences were only statistically significant for seaweed sample of G. changii and agar sample of G. salicornia. RNA sequencing (RNA-Seq) of sulfate-deprivated and untreated seaweed samples revealed 1,292 and 3,439 differentially expressed genes (DEGs; ≥1.5-fold) in sulfate-deprivated G. changii and G. salicornia, respectively, compared to their respective controls. Among the annotated DEGs were genes involved in putative agar biosynthesis, sulfur metabolism, metabolism of sulfur-containing amino acids, carbon metabolism and oxidative stress. These findings shed light on the sulfate deprivation responses in agarophytes and help to identify candidate genes involved in agar biosynthesis.

  7. PERFIL ETIOLÓGICO DA MASTITE BOVINA NA BACIA LEITEIRA DE SANTA IZABEL DO OESTE, PARANÁ

    Directory of Open Access Journals (Sweden)

    Lucianne Leigue dos Santos

    2010-12-01

    Full Text Available Clinical or sub-clinical mastitis are the main illnesses that affect dairy herds, with impact on the economy, the industry, and with consequence to public health. Considering that the city of Santa Izabel do Oeste is located in the second bigger milk region of Paraná state, and that mastitis cases are epidemiologically classified as ambient or contagious, the purpose of this study was to identify possible etiologic agents of bovine mastitis, by the use of a preliminary, fast and cheap diagnostic method to differentiate these types of illness, to orient treatment and prophylactic measures. Two triplates were employed. Triplate I was composed by blood agar, bile-esculine agar and mannitol-salt agar, while triplate II was composed by MacConkey agar; Baird-Parker agar and sabouraud-dextrose agar with cloranfenicol. Additionally, a tube with sabouraud-dextrose agar with cloranfenicol incubated at room temperature temperature was used for the research of filamentous moulds. It was observed that the great majority of the isolated samples had Staphylococcus coagulase negative, coliforms, Staphylococcus aureus, no-fermenters bacilli gram negative, Coryneforms, Streptococcus spp. and Streptococcus agalactiae.

  8. Semi-selective medium for Fusarium graminearum detection in seed samples

    Directory of Open Access Journals (Sweden)

    Marivane Segalin

    2010-12-01

    Full Text Available Fungi of the genus Fusarium cause a variety of difficult to control diseases in different crops, including winter cereals and maize. Among the species of this genus Fusarium graminearum deserves attention. The aim of this work was to develop a semi-selective medium to study this fungus. In several experiments, substrates for fungal growth were tested, including fungicides and antibiotics such as iprodiona, nystatin and triadimenol, and the antibacterial agents streptomycin and neomycin sulfate. Five seed samples of wheat, barley, oat, black beans and soybeans for F. graminearum detection by using the media Nash and Snyder agar (NSA, Segalin & Reis agar (SRA and one-quarter dextrose agar (1/4PDA; potato 50g; dextrose 5g and agar 20g, either unsupplemented or supplemented with various concentrations of the antimicrobial agents cited above. The selected components and concentrations (g.L-1 of the proposed medium, Segalin & Reis agar (SRA-FG, were: iprodiona 0.05; nystatin 0,025; triadimenol 0.015; neomycin sulfate 0.05; and streptomycin sulfate, 0.3 added of ¼ potato sucrose agar. In the isolation from seeds of cited plant species, the sensitivity of this medium was similar to that of NSA but with de advantage of maintaining the colony morphological aspects similar to those observed in potato-dextrose-agar medium.

  9. Gelling agents and culture vessels affect in vitro multiplication of banana plantlets.

    Science.gov (United States)

    Kaçar, Y A; Biçen, B; Varol, I; Mendi, Y Y; Serçe, S; Cetiner, S

    2010-03-09

    Agar is the most commonly used gelling agent in media for plant tissue culture. Because of the high price of tissue-culture-grade agar, attempts have been made to identify suitable alternatives. The type of culture vessel and lid also affects the gaseous composition inside the vessel as well as light penetration. In turn, the vessel affects growth parameters, such as shoot elongation, proliferation and fresh weight, as well as hyperhydric degradation processes. We examined the effects of different culture vessels, including commercial glass jars, magenta boxes, and disposable containers, as well as different gelling agents (agar-agar, Agargel, Phytagel, and plant agar) on the micropropagation of Dwarf Cavendish bananas in an effort to find a combination that yields large numbers of high-quality seedlings. The different culture vessels did not significantly affect seedling culture success. The medium significantly affected shoot weight. Phytagel resulted in the highest shoot weight (overall mean = 2.4 g), while agar, Agargel and plant agar resulted in 1.7, 2.2 and 2.2 g, respectively. Disposable container/Phytagel and Magenta/Agargel combinations yielded the highest shoot weights (2.9 and 3.0 g, respectively). Mean shoot length increased progressively with subculture (four subcultures were made). The highest mean shoot length was obtained with Phytagel and Agargel media (6.4 and 6.3 cm, respectively). Shoot number was significantly affected by medium only at subculture 4. Overall, the highest mean shoot length was obtained with the Magenta/Agargel combination (8.5 cm). Phytagel and plant agar gave higher mean shoot number than agar and Agargel (2.1, 2.1 and 1.7 and 1.9, respectively). The costs of the media and of the culture vessels need to be taken into account for final choice of the banana shoot culture system.

  10. Culture Phenotypes of Genomically and Geographically Diverse Mycobacterium avium subsp. paratuberculosis Isolates from Different Hosts▿

    Science.gov (United States)

    Whittington, Richard J.; Marsh, Ian B.; Saunders, Vanessa; Grant, Irene R.; Juste, Ramon; Sevilla, Iker A.; Manning, Elizabeth J. B.; Whitlock, Robert H.

    2011-01-01

    Mycobacterium avium subsp. paratuberculosis causes paratuberculosis (Johne's disease) in ruminants in most countries. Historical data suggest substantial differences in culturability of M. avium subsp. paratuberculosis isolates from small ruminants and cattle; however, a systematic comparison of culture media and isolates from different countries and hosts has not been undertaken. Here, 35 field isolates from the United States, Spain, Northern Ireland, and Australia were propagated in Bactec 12B medium and Middlebrook 7H10 agar, genomically characterized, and subcultured to Lowenstein-Jensen (LJ), Herrold's egg yolk (HEY), modified Middlebrook 7H10, Middlebrook 7H11, and Watson-Reid (WR) agars, all with and without mycobactin J and some with sodium pyruvate. Fourteen genotypes of M. avium subsp. paratuberculosis were represented as determined by BstEII IS900 and IS1311 restriction fragment length polymorphism analysis. There was no correlation between genotype and overall culturability, although most S strains tended to grow poorly on HEY agar. Pyruvate was inhibitory to some isolates. All strains grew on modified Middlebrook 7H10 agar but more slowly and less prolifically on LJ agar. Mycobactin J was required for growth on all media except 7H11 agar, but growth was improved by the addition of mycobactin J to 7H11 agar. WR agar supported the growth of few isolates. The differences in growth of M. avium subsp. paratuberculosis that have historically been reported in diverse settings have been strongly influenced by the type of culture medium used. When an optimal culture medium, such as modified Middlebrook 7H10 agar, is used, very little difference between the growth phenotypes of diverse strains of M. avium subsp. paratuberculosis was observed. This optimal medium is recommended to remove bias in the isolation and cultivation of M. avium subsp. paratuberculosis. PMID:21430104

  11. Exploration of Yeast and Bacteria Contaminants in Seed Culture and Fermented Wort from Gyo Gon Alcohol Distillery

    International Nuclear Information System (INIS)

    Ngwe Thein

    2005-10-01

    Study was made on samples of seed culture and fermented wort from Gyogon alcohol distillery. In all samples bacteria contaminants were observed. Samples were cultured on Sabouraud dextrose agar, Czapek Dox agar, and nutrient agar media and broth. The selected colonies were isolated. Biochemical tests for identification were conducted. The yeast and bacteria contaminants were identified by morphological characteristics and biochemical reactions. The yeast isolated and identified from Gyogon alcohol distillery was Sacchacromyces cerevisiae. The bacteria contaminants isolated and identified were Aeromonas sp. and Pseudomonas sp.

  12. From silver nanoparticles to nanostructures through matrix chemistry

    International Nuclear Information System (INIS)

    Ayyad, Omar; Munoz-Rojas, David; Oro-Sole, Judith; Gomez-Romero, Pedro

    2010-01-01

    Direct in situ reduction of silver ions by a biopolymer such as agar, without any other reducing nor capping agent is shown in this article to lead either to nanoparticles (typically 12(2) nm in an optimized case) or to more complex nanostructures depending on the reaction conditions used. This approach takes advantage of the porous polymer lattice acting as a template and leads to hybrid Ag-Agar materials with long-term synergic stability. Silver acts as an antibacterial agent for agar whereas the biopolymer prevents agglomeration of the inorganic nanoparticles leading to a stable nanocomposite formed by a thermoreversible biopolymer from which silver nanoparticles can eventually be recovered.

  13. Isolation and characterization of a novel agarase-producing Pseudoalteromonas spp. bacterium from the guts of spiny turban shells.

    Science.gov (United States)

    Oh, Young Hoon; Jung, Changkyou; Lee, Jinwon

    2011-08-01

    An agar-degrading bacterium was isolated from the guts of spiny turban shells. It was identified as a Pseudoalteromonas species and named Pseudoalteromonas sp. JYBCL 1. The viscosity of the inoculated agar medium decreased by more than 60% after 20 h cultivation. The agarase produced by the isolate had optimal activities at 35 degrees C and pH 7. The enzyme had extremely strong resistance to ionic stress compared with other known agarases. Its molecular mass was estimated at about 60 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The agarase could saccharify Gelidium amansii directly, with an efficiency about half that compared with agar saccharification.

  14. Prospective Comparison of a New Chromogenic Medium, MRSASelect, to CHROMagar MRSA and Mannitol-Salt Medium Supplemented with Oxacillin or Cefoxitin for Detection of Methicillin-Resistant Staphylococcus aureus

    Science.gov (United States)

    Stoakes, Luba; Reyes, Romina; Daniel, Janis; Lennox, Gwen; John, Michael A.; Lannigan, Robert; Hussain, Zafar

    2006-01-01

    MRSASelect agar was compared to CHROMagar, mannitol-salt agar with oxacillin, and mannitol-salt agar with cefoxitin (MSA-CFOX) for the isolation of methicillin-resistant Staphylococcus aureus (MRSA). The sensitivities and specificities were 97.3% and 99.8%, 82.9% and 99.1%, 80.2% and 79%, and 99.1% and 84.8%, respectively. MSA-CFOX and MRSASelect had a high sensitivity. MRSASelect, however, was more specific and proved to be a more reliable and rapid medium for the detection of MRSA. PMID:16455933

  15. ISOLATION AND PURIFICATION OF STREPTOMYCES SPP. PRODUCING VANCOMYCIN

    International Nuclear Information System (INIS)

    EL-KABBANY, H.M.I.

    2008-01-01

    Soil samples obtained from different governments in Egypt were analyzed to determine the presence of types of antibiotic producing actinomycetes using starch-nitrite agar, starch-casein nitrate agar and Czapek's Dox agar as culture media. Different Streptomyces spp. were isolated. The Streptomyces (S.) isolates encountered were S. violochromogens, S. violaceus-nigar and S. orientalis and known as standard Vancomycin producers. The optimum conditions of S. orientalis; incubation period, initial pH and incubation temperature, were determined. In addition, physical properties; appearance, melting point, solubility, mass spectrophotometer of ultra violet (UV) and the effect of gamma rays, were also determined

  16. Sporotrichosis caused by Sporothrix globosa in Rio De Janeiro, brazil: case report.

    Science.gov (United States)

    de Oliveira, Manoel Marques Evangelista; de Almeida-Paes, Rodrigo; de Medeiros Muniz, Mauro; de Lima Barros, Monica Bastos; Galhardo, Maria Clara Gutierrez; Zancope-Oliveira, Rosely Maria

    2010-05-01

    This report describes the first isolation of Sporothrix globosa from a Brazilian patient. A 77-year-old woman was examined for sporotrichosis infection. Histopathological examination of skin biopsy revealed chronic granulomatous infiltrate with microabcess. Furthermore, S. schenckii-like yeasts were evident as demonstrated by PAS and Grocott stains. The fungus was identified based on colony morphology on Sabouraud Dextrose Agar slants, Potato Dextrose Agar, and Corn Meal Agar, microscopic morphology on slides cultures, and assimilation of different carbon sources. The species confirmation was made by molecular methodology.

  17. Examination of some protective conditions on technological properties of irradiated food grade polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Adeil Pietranera, M.S. E-mail: pietrane@cae.cnea.gov.ar; Narvaiz, P. E-mail: narvaiz@cae.cnea.gov.ar

    2001-02-01

    Corn and cassava starches, agar-agar and kappa carrageenan, polysaccharides used as food additives, were gamma irradiated with doses suitable for microbial decontamination. Starches were analysed in paste and pudding viscosity and paper chromatography; agar and carrageenan, in viscosity and compression tests on gels and custards. Afterwards, substances were added to verify whether they could prevent irradiation technological impairment. Results revealed significant differences between control and irradiated samples in most determinations. No added substance was able to protect the functional properties of these additives. (author)

  18. Liesegang bands versus random crystallites in Ag2Cr2O7 - Single and mixed gelled media

    Science.gov (United States)

    Ibrahim, Huria; El-Rassy, Houssam; Sultan, Rabih

    2018-02-01

    Liesegang patterns of silver dichromate (Ag2Cr2O7) are studied in two different gel media: agar and gelatin, based on the work of Lagzi and Ueyama (2009). Whereas in gelatin, standard Liesegang bands are obtained as a result of the interdiffusion of Ag+ and Cr2 O72-, random crystallites with dendritic ramifications are observed in agar. We revisit this phenomenon and demonstrate the proposed mechanism, wherein dense heterogeneous nucleation in gelatin leads to Liesegang bands, as opposed to surface nucleation in agar yielding crystallites. We use viscosity, pH measurements, and notably scanning electron microscopy (SEM) in this endeavor.

  19. Pseudomonad Swarming Motility Is Restricted to a Narrow Range of High Matric Water Potentials

    DEFF Research Database (Denmark)

    Dechesne, Arnaud; Smets, Barth F.

    2012-01-01

    Using a novel experimental system that allows control of the matric potential of an agar slab, we explored the hydration conditions under which swarming motility is possible. If there is recognition that this physical parameter is a key determinant of swarming, it is usually neither controlled nor...... measured rigorously but only manipulated through proxies, namely, the agar concentration and the drying time of "soft" agar plates (swarming plates). We contend that this not only obscures the biophysical mechanisms underlying swarming but also impedes a full assessment of its clinical and environmental...

  20. Laboratory invesitgations of variability of Ascochyta fabae Speg. isolates obtained from horse bean

    Directory of Open Access Journals (Sweden)

    Antoni Józef Filipowicz

    2014-08-01

    Full Text Available Fifty five isolates of Ascochyta fabae Speg. were investigated. They were selected from 1650 isolates of this fungus obtained from horse bean seeds in 1974-1976. All the isolates grew and sporulated on Potato Dextrose Agar, Malt Agar and Horse Bean Agar. The rate of their growth amounted to 1-4 mm per 24 hours. The variability of isolates in size of pycnidia and conidia and number of sepia was noticed. A few spores with untypical shapes were observed as well.