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Sample records for agar medium supplemented

  1. [Laboratory-based evaluation of a selective X-SA agar medium supplemented with chromogenic substrate for Staphylococcus aureus].

    PubMed

    Nakasone, Isamu; Yamane, Nobuhisa

    2005-01-01

    The newly developed culture medium, X-SA agar medium (Nissui Pharmaceuticals Co., Ltd., Tokyo) selective for Staphylococcus aureus was evaluated for its ability to detect clinical isolates of S. aureus. Besides S. aureus, X-SA agar media allowed the growth of coagulase-negative staphylococci, Bacillus cereus and some isolates of corynebacteria. However, those species were easily distinguishable from the blue and convex colonies of S. aureus. When compared to the traditional egg yolk mannitol salt agar, selectivity for the species other than S. aureus was more specific, and growth support for S. aureus was more comparable to sheep blood agar. Also, when various phenotypic variants of S. aureus were inoculated, visible colonies of mucoid colony variants and attenuated growth variants on Mueller-Hinton agar appeared on X-SA agar plates after 24 hour-incubation, but it required 48 hour-incubation for small colony variants. The fully automated microbiology system, RAISUS (Nissui Pharmaceuticals Co., Ltd.) gave comparable species-identification and antimicrobial susceptibility test results when cell suspension directly prepared from X-SA agar media was tested. However, species-identification for phenotypic variants of S. aureus was more complicated for RAISUS testing and detection of coagulase. With these results, it could be concluded that the X-SA agar medium supplemented with chromogenic substrate is superior to the traditional selective media for the detection of S. aureus, and is widely applicable for clinical microbiology as well as food microbiology.

  2. [Evaluation of blood agar medium for the growth of mycobacteria].

    PubMed

    Coban, Ahmet Yılmaz; Akgüneş, Alper; Durupınar, Belma

    2011-10-01

    This study was aimed to evaluate the performance of blood agar for the growth of mycobacteria from clinical specimens sent to Mycobacteriology Laboratory of Samsun Chest Diseases Hospital. One hundred fifty six clinical specimens including 123 sputum, 28 bronchoalveolar lavage (BAL) and 5 pleural fluid specimens were inoculated in Löwenstein-Jensen (LJ), BACTEC MGIT 960 system (Becton Dickinson, USA) and blood agar following decontamination process. The specimens were also simultaneously examined for the presence of acid-fast bacilli (AFB). Thirty five mycobacteria strains (33 Mycobacterium tuberculosis and 2 atypical mycobacteria) grew in blood agar, 38 (36 M.tuberculosis and 2 atypical mycobacteria) in LJ media and 46 (44 M.tuberculosis and 2 atypical mycobacteria) in BACTEC MGIT 960 system. Among 29 AFB negative specimens, 20 revealed growth in both blood agar and LJ medium and 27 in MGIT system. AFB positive 20 samples yielded growth in 15 samples in blood agar, 18 in LJ medium and 19 in MGIT system. Among the total of 156 samples, contamination was observed in 15 (9.6%) samples in blood agar, 16 (10.2%) in LJ medium and 18 (11.5%) in MGIT system. Growth time was 5-35 days (mean 18 ± 7.4), 11-35 days (mean 19 ± 5.9) and 5-15 days (mean 10 ± 2.4) for blood agar, LJ medium and BACTEC MGIT 960 system, respectively. The three samples which revealed contamination in BACTEC MGIT 960 system, grew successfully in both blood agar and LJ medium without contamination. In one sample, growth was observed only in LJ medium but neither in blood agar nor BACTEC MGIT 960 system. However, in another sample, growth was observed only in blood agar while no growth was detected in LJ or BACTEC MGIT 960 system. Six samples yielded mycobacteria only in BACTEC MGIT 960 system. These results indicated that simultaneous use of one liquid and one solid medium to grow mycobacteria from the clinical samples seemed to be complementary. Blood agar was a promising choice since it was found

  3. Standard Nutrient Agar 1 as a substitute for blood-supplemented Müller-Hinton agar for antibiograms in developing countries.

    PubMed

    Niederstebruch, N; Sixt, D

    2013-02-01

    In the industrial world, the agar diffusion test is a standard procedure for the susceptibility testing of bacteria isolates. Beta-hemolytic Streptococcus spp. are tested with Müller-Hinton agar supplemented with 5 % blood, a so-called blood agar. The results are interpreted using standardized tables, which only exist for this type of nutrient matrix. Because of a number difficulties, both with respect to technical issues and to manual skills, blood agar is not a feasible option in many developing countries. Beta-hemolytic Streptococcus spp. also grow on Standard Nutrient Agar 1 (StNA1). This suggests using that type of nutrient medium for running agar diffusion tests. However, there are no standardized tables that can be used for interpreting the diameters of the zones of inhibition on StNA1 1. Using the existing standardized tables for blood agar to interpret cultures on StNA1 1 would be of great benefit under such circumstances where blood agar is not available. With this in mind, we conducted comparative tests to evaluate the growth characteristics of beta-hemolytic Streptococcus spp. on StNA1 1 compared to Müller-Hinton agar supplemented with 5 % sheep blood. In this study, we were able to show that beta-hemolytic Streptococcus spp. develop similar zones of inhibition on blood agar and on StNA1 1. Therefore, it is suggested that, for the interpretation of antibiograms of beta-hemolytic Streptococcus spp. performed on StNA1 1, the standard tables for blood agar can be used.

  4. Standard Nutrient Agar 1 as a substitute for blood-supplemented Müller-Hinton agar for antibiograms in developing countries.

    PubMed

    Niederstebruch, N; Sixt, D

    2013-02-01

    In the industrial world, the agar diffusion test is a standard procedure for the susceptibility testing of bacteria isolates. Beta-hemolytic Streptococcus spp. are tested with Müller-Hinton agar supplemented with 5 % blood, a so-called blood agar. The results are interpreted using standardized tables, which only exist for this type of nutrient matrix. Because of a number difficulties, both with respect to technical issues and to manual skills, blood agar is not a feasible option in many developing countries. Beta-hemolytic Streptococcus spp. also grow on Standard Nutrient Agar 1 (StNA1). This suggests using that type of nutrient medium for running agar diffusion tests. However, there are no standardized tables that can be used for interpreting the diameters of the zones of inhibition on StNA1 1. Using the existing standardized tables for blood agar to interpret cultures on StNA1 1 would be of great benefit under such circumstances where blood agar is not available. With this in mind, we conducted comparative tests to evaluate the growth characteristics of beta-hemolytic Streptococcus spp. on StNA1 1 compared to Müller-Hinton agar supplemented with 5 % sheep blood. In this study, we were able to show that beta-hemolytic Streptococcus spp. develop similar zones of inhibition on blood agar and on StNA1 1. Therefore, it is suggested that, for the interpretation of antibiograms of beta-hemolytic Streptococcus spp. performed on StNA1 1, the standard tables for blood agar can be used. PMID:22926453

  5. Agar Medium for Differential Enumeration of Lactic Streptococci1

    PubMed Central

    Reddy, M. S.; Vedamuthu, E. R.; Washam, C. J.; Reinbold, G. W.

    1972-01-01

    An agar medium containing arginine and calcium citrate as specific substrates, diffusible (K2HPO4) and undiffusible (CaCO3) buffer systems, and bromocresol purple as the pH indicator was developed to differentiate among lactic streptococci in pure and mixed cultures. Milk was added as the sole source of carbohydrate (lactose) and to provide growth-stimulating factors. Production of acid from lactose caused developing bacterial colonies to seem yellow. Subsequent arginine utilization by Streptococcus lactis and S. diacetilactis liberated ammonia, resulting in a localized pH shift back toward neutrality and a return of the original purple indicator hue. The effects of production of acid from lactose and ammonia were fixed around individual colonies by the buffering capacity of CaCO3. After 36 hr at 32 C in a candle oats jar, colonies of S. cremoris were yellow, whereas colonies of S. lactis and S. diacetilactis were white. S. diacetilactis, on further incubation, utilized suspended calcium citrate, and, after 6 days, the citrate-degrading colonies exhibited clear zoning against a turbid background, making them easily distinguishable from the colonies of the other two species. The medium proved suitable for quantitative differential enumeration when compared with another widely used general agar medium for lactic streptococci. Images PMID:16349952

  6. Production of microbial medium from defatted brebra (Milletia ferruginea) seed flour to substitute commercial peptone agar

    PubMed Central

    Andualem, Berhanu; Gessesse, Amare

    2013-01-01

    Objective To investigate and optimize microbial media that substitute peptone agar using brebra seed defatted flour. Methods 'Defatted process, inoculums preparation, evaluation of bacterial growth, preparation of cooked and hydrolyzed media and growth turbidity of tested bacteria were determined. Results Two percent defatted flour was found to be suitable concentration for the growth of pathogenic bacteria: Escherichia coli (ATCC 25922) (E. coli), Pseudomonas aeruginosa (ATCC 27853), Salmonella (NCTC 8385) and Shigella flexneri (ATCC 12022) (S. flexneri), while 3% defatted flour was suitable for Staphylococcus aureus (ATCC 25923) (S. aureus). E. coli (93±1) and S. flexneri (524±1) colony count were significantly (P≤0.05) greater in defatted flour without supplement than in supplemented medium. E. coli [(3.72×109±2) CFU/mL], S. aureus [(7.4×109±2) CFU/mL], S. flexneri [(4.03×109±2) CFU/mL] and Salmonella [(2.37×109±1) CFU/mL] in non-hydrolyzed sample were statistically (P≤0.05) greater than hydrolyzed one and commercial peptone agar. Colony count of Salmonella [(4.55×109±3) CFU/mL], S. flexneri [(5.40×109±3) CFU/mL] and Lyesria moncytogenes (ATCC 19116) [(5.4×109±3) CFU/mL] on raw defatted flour agar was significantly (P≤0.05) greater than cooked defatted flour and commercial peptone agar. Biomass of E. coli, S. aureus, Salmonella and Enterococcus faecalis in non-hydrolyzed defatted flour is highly increased over hydrolyzed defatted flour and commercial peptone broth. Conclusions The defatted flour agar was found to be better microbial media or comparable with peptone agar. The substances in it can serve as sources of carbon, nitrogen, vitamins and minerals that are essential to support the growth of microorganisms without any supplements. Currently, all supplements of peptone agar are very expensive in the market. PMID:24075344

  7. [Evaluation of a new medium, eggplant (Solanum melongena) agar as a screening medium for Cryptococcus neoformans in environmental samples].

    PubMed

    Sengul, Mustafa; Ergin, Cağrı; Kartal, Tuğba

    2014-04-01

    Cryptococcus neofomans is an encapsulated yeast-like fungus that causes life-threatening infections, especially in immunosuppresive patients. C.neoformans infection is believed to be acquired via inhalation of aerosolized particles from the environment. Avian guano, decaying tree hollows and soil are the related known environmental niches. Brown pigmented yeast growth from the precursors in growth media is an important step for the identification and isolation of C.neoformans. Seeds of plants in nature are preferred owing to easy accessibility and low costs for the preparation of such media. Guizotia abysinicca (Niger seed) as Staib agar, Helianthus annus (Sunflower) as Pal's medium, Brassica nigra (Mustard) agar, tobacco agar, Mucuna pruriens (Velvet bean) seed agar, Perilla frutescens (Beefsteak plant) seed agar, Rubus fruticosus (Blackberry) agar and ground red hot pepper agar are pigment-based selective media for the differentiation of C.neoformans. The aim of this study was to observe the pigment production of C.neoformans in a new medium based on eggplant (Solanum melongena) and also to compare its performance with the simplified Staib, Pal's and tobacco agar for isolation from the environment. Three different eggplant-based medium (S.melongena Melanzaza viserba, S.melongena Pinstripe F1 and S.ovigerum Ivory F1) were included in the study. Pigment-forming eggplant medium, simplified Staib agar, Pal's agar and tobacco agar were used for the cultivation of the environmental swabbed samples from 19 Eucalyptus camaldulensis trunk hollows in continuous colonization region. While pigment formation were observed with S.melongena Melanzaza viserba and S.melongena Pinstripe F1 containing media, S.ovigerum Ivory F1 medium was found to be non-reactive. In colonization area (Gökova-Akyaka, Turkey), 11 (57.9%) out of 19 E.camaldulensis samples were positive with simplified Staib agar, Pal's agar and eggplant agar while 10 (52.6%) of them are positive with tobacco agar. C

  8. [Evaluation of a new medium, eggplant (Solanum melongena) agar as a screening medium for Cryptococcus neoformans in environmental samples].

    PubMed

    Sengul, Mustafa; Ergin, Cağrı; Kartal, Tuğba

    2014-04-01

    Cryptococcus neofomans is an encapsulated yeast-like fungus that causes life-threatening infections, especially in immunosuppresive patients. C.neoformans infection is believed to be acquired via inhalation of aerosolized particles from the environment. Avian guano, decaying tree hollows and soil are the related known environmental niches. Brown pigmented yeast growth from the precursors in growth media is an important step for the identification and isolation of C.neoformans. Seeds of plants in nature are preferred owing to easy accessibility and low costs for the preparation of such media. Guizotia abysinicca (Niger seed) as Staib agar, Helianthus annus (Sunflower) as Pal's medium, Brassica nigra (Mustard) agar, tobacco agar, Mucuna pruriens (Velvet bean) seed agar, Perilla frutescens (Beefsteak plant) seed agar, Rubus fruticosus (Blackberry) agar and ground red hot pepper agar are pigment-based selective media for the differentiation of C.neoformans. The aim of this study was to observe the pigment production of C.neoformans in a new medium based on eggplant (Solanum melongena) and also to compare its performance with the simplified Staib, Pal's and tobacco agar for isolation from the environment. Three different eggplant-based medium (S.melongena Melanzaza viserba, S.melongena Pinstripe F1 and S.ovigerum Ivory F1) were included in the study. Pigment-forming eggplant medium, simplified Staib agar, Pal's agar and tobacco agar were used for the cultivation of the environmental swabbed samples from 19 Eucalyptus camaldulensis trunk hollows in continuous colonization region. While pigment formation were observed with S.melongena Melanzaza viserba and S.melongena Pinstripe F1 containing media, S.ovigerum Ivory F1 medium was found to be non-reactive. In colonization area (Gökova-Akyaka, Turkey), 11 (57.9%) out of 19 E.camaldulensis samples were positive with simplified Staib agar, Pal's agar and eggplant agar while 10 (52.6%) of them are positive with tobacco agar. C

  9. A supplemented soft agar chemotaxis assay demonstrates the Helicobacter pylori chemotactic response to zinc and nickel

    PubMed Central

    Sanders, Lisa; Andermann, Tessa M.

    2013-01-01

    Directed motility, or chemotaxis, is required for Helicobacter pylori to establish infection in the stomach, although the full repertoire of this bacterium’s chemotactic responses is not yet known. Here we report that H. pylori responds to zinc as an attractant and nickel as a repellent. To reach this conclusion, we employed both a temporal chemotaxis assay based on bacterial reversals and a supplemented soft agar spatial assay. We refined the temporal assay using a previously described chemorepellent, acid, and found that H. pylori requires rich media with serum to maintain optimal swimming motility. Surprisingly, we found that some strains respond to acid as an attractant, and that the TlpC chemoreceptor correlated with whether acid was sensed as an attractant or repellent. Using this same assay, we detected weak repellent responses to nickel and copper, and a varied response to zinc. We thus developed an alternative spatial chemotactic assay called the supplemented soft agar assay, which utilizes soft agar medium supplemented with the test compound. With Escherichia coli, the attractant serine slowed overall bacterial migration, while the repellent nickel increased the speed of overall migration. In H. pylori we detected slowed migration with doubled tryptone media, as well as zinc, consistent with an attractant response. In contrast, nickel increased migration, consistent with repulsion. PMID:23139399

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

    PubMed Central

    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

  11. Evaluation of agar-based medium with sheep sera for testing of drug susceptibility of Mycobacterium tuberculosis to Isoniazid, Rifampin, Ethambutol, and Streptomycin.

    PubMed

    Coban, Ahmet Yilmaz; Uzun, Meltem; Bozdogan, Bulent

    2013-12-01

    The performance of sheep sera instead of sheep blood in agar-based media was investigated for susceptibility testing of Mycobacterium tuberculosis against primary drugs. The levels of agreement between agar-based medium supplemented with sheep sera and the proportion method on Middlebrook 7H11 agar as the reference method for determining susceptibility to isoniazid (INH), rifampin (RIF), ethambutol (EMB), and streptomycin (STR) were 98.4, 98.4, 95.3, and 100%, respectively.

  12. Development of an improved selective agar medium for isolation of Yersinia pestis.

    PubMed

    Ber, Raphael; Mamroud, Emanuelle; Aftalion, Moshe; Tidhar, Avital; Gur, David; Flashner, Yehuda; Cohen, Sara

    2003-10-01

    Existing media designed for selective isolation of clinically important members of the genus Yersinia were found to be unsatisfactory for the growth and isolation of Yersinia pestis. We report the development of a new selective agar medium (termed BIN) that supports the growth of Y. pestis. The development of the formulation of this medium was based on a fluorescence screening system designed for monitoring bacterial growth on semisolid media, using a green fluorescent protein-expressing strain. High-throughput combinatorial experiments can be conducted for the quantitative evaluation of the effect of different medium components on growth. Generation of fluorescence plots in this system, using microplates, allowed the quantitative evaluation of the growth rate of Y. pestis EV76 cultures in different agar compositions. The final BIN formulation is based on brain heart infusion agar, to which the selective agents irgasan, cholate salts, crystal violet, and nystatin were introduced. It was found that BIN agar is more efficient in supporting colony formation and recovery of Y. pestis than are the conventional semisolid media MacConkey agar and Yersinia-selective agar (cefsulodin-irgasan-novobiocin agar). The advantage of BIN over other media has been also demonstrated in recovering virulent Y. pestis from the mixed bacterial populations found in decaying carcasses of infected mice. The BIN medium is suggested as a selective medium for isolation and recovery of Y. pestis from various backgrounds.

  13. A note on a selective agar medium for the enumeration of Flavobacterium species in water.

    PubMed

    Flint, K P

    1985-12-01

    A selective nutrient agar medium containing kanamycin at 50 micrograms/ml was developed for the isolation and enumeration of yellow-pigmented colonies from the River Sowe, Coventry. Such organisms were shown to be members of the heterogeneous genus Flavobacterium. Typically, yellow pigmented colonies constituted less than 10% of the colonies on nutrient agar alone but up to 70% on nutrient agar plus kanamycin. This medium is a useful addition to the range of media available for the isolation and further ecological study of particular species of this important group of micro-organisms.

  14. Comparison of Ashdown's medium, Burkholderia cepacia medium, and Burkholderia pseudomallei selective agar for clinical isolation of Burkholderia pseudomallei.

    PubMed

    Peacock, Sharon J; Chieng, Grace; Cheng, Allen C; Dance, David A B; Amornchai, Premjit; Wongsuvan, Gumphol; Teerawattanasook, Nittaya; Chierakul, Wirongrong; Day, Nicholas P J; Wuthiekanun, Vanaporn

    2005-10-01

    Ashdown's medium, Burkholderia pseudomallei selective agar (BPSA), and a commercial Burkholderia cepacia medium were compared for their abilities to grow B. pseudomallei from 155 clinical specimens that proved positive for this organism. The sensitivity of each was equivalent; the selectivity of BPSA was lower than that of Ashdown's or B. cepacia medium.

  15. A NEW SELECTIVE BLOOD AGAR MEDIUM FOR STREPTOCOCCUS PYOGENES AND OTHER HAEMOLYTIC STREPTOCOCCI.

    PubMed

    LOWBURY, E J; KIDSON, A; LILLY, H A

    1964-05-01

    Horse blood agar containing polymyxin B sulphate, neomycin sulphate, and fusidic acid inhibited the growth of Staph. aureus, Ps. pyocyanea, Proteus mirabilis, E. coli, and Klebsiella pneumoniae but allowed good growth of, and haemolysis by, Str. pyogenes. In a comparison with blood agar, blood 4% agar, and gentian violet blood agar, the selective medium (P.N.F.) yielded a significantly higher proportion of streptococci than the other media, both by aerobic and by anaerobic culture, from burn swab extracts deliberately contaminated with Str. pyogenes; P.N.F. culture was more effective with dilute than with heavy inocula of Str. pyogenes, allowing from three to seven times as many recoveries of Str. pyogenes from swabs contaminated with 10(-3) dilution of streptococcal cultures than cultures of the same material on the other media. Haemolytic streptococci of groups A, C, D, G, and others were isolated by aerobic culture from burns in a consecutive series of 1,277 swabs more often on P.N.F. medium than on blood 4% agar. Viable counts of 12 strains (including 11 different serological types) of Str. pyogenes showed some reduction in the numbers of colonies compared with counts on blood agar, and some strains grew more slowly on P.N.F. medium. These limitations, however, were offset and outweighed by the higher final yield of streptococci on the selective medium.

  16. Nutrient agar with sodium chloride supplementation for presumptive detection of Moraxella catarrhalis in clinical specimens.

    PubMed

    Nishiyama, Hiroyuki; Saito, Ryoichi; Chida, Toshio; Sano, Kazumitsu; Tsuchiya, Tatsuyuki; Okamura, Noboru

    2012-04-01

    We previously reported that Nissui nutrient agar (N medium) promoted the growth of Moraxella catarrhalis but not commensal Neisseria spp. In the present study, we examined which constituent of N medium was responsible for the selective growth of M. catarrhalis using 209 M. catarrhalis and 100 commensal Neisseria spp. clinical strains. We found that peptone, but not meat extract or agar of N medium, had growth-promoting or growth-inhibiting ability with respect to M. catarrhalis and commensal Neisseria spp. Thus, we investigated the amino acid content of N peptone and found it had higher concentrations of amino acids than other commercial peptone products. On varying the sodium chloride concentration of reconstituted N medium, we noted that the concentration was an important factor in bacterial growth differences. Varying the sodium chloride concentration of other commercial nutrient agars achieved similar results to those for N medium. This is, to our knowledge, the first study observing that sodium chloride concentration is responsible for difference in growth between the two organisms. We also successfully isolated colonies of M. catarrhalis from respiratory specimens on N medium, whereas the growth of commensal Neisseria spp. was inhibited, and by adding bovine hematin and β-NAD we were able to isolate Haemophilus influenzae colonies as efficiently as with a chocolate agar. In conclusion, nutrient agar can be used as a medium for the preferential isolation of M. catarrhalis from upper respiratory tract specimens.

  17. A preliminary evaluation of a new selective agar supplemented with desferrioxamine for detection of methicillin-resistant Staphylococcus aureus.

    PubMed

    Monsen, T; Olofsson, C; Granström, S; Wiström, J

    2003-07-01

    The aim of the present study was to evaluate the performance of two new selective screening agars, Colombia agar supplemented with 1000 mg/L desferrioxamine, 5 mg/L amphotericin B, 16 mg/L polymyxin B, and 2 mg/L methicillin (CMDAP agar) or 0.5 mg/L oxacillin (CODAP agar), for detection of methicillin-resistant Staphylococcus aureus (MRSA). Both the CMDAP and the CODAP agar effectively inhibited growth of 151 isolates of coagulase-negative staphylococci (CoNS), 45 of Enterobacteriaceae and six Candida spp. examined. The sensitivity and specificity of the CMDAP and CODAP agars for detection of MRSA was calculated by comparing the growth of 52 MRSA with the inhibition of 74 mecA negative S. aureus and of 151 CoNS. The performance of the new agars was compared with four previously described MRSA screening agars. The sensitivity and specificity for detection of MRSA after incubation at 35 degrees C for 24 h was 0.94 and 0.91, respectively, for the CMDAP agar, 0.60 and 0.90 for the CODAP agar, 0.98 and 0.57 for methicillin aztreonam mannitol salt agar (MAMSA), 0.23 and 0.84 for oxacillin mannitol salt agar (OMSA), 0.48 and 0.76 for oxacillin Mueller-Hinton agar (OMHA) and 0.75 and 0.77 for lithium oxacillin mannitol salt agar (LOMSA). Agars supplemented with desferrioxamine, CMDAP and CODAP, were more specific for detecting MRSA compared with agars not supplemented with desferrioxamine. The detection rate was higher for agars supplemented with methicillin than for agars supplemented with oxacillin.

  18. A new chromogenic agar medium for detection of potentially virulent Yersinia enterocolitica.

    PubMed

    Weagant, Stephen D

    2008-02-01

    Several outbreaks of foodborne yersiniosis have been documented and this disease continues to be source of infections transmitted through foods. The selective agars most commonly used to isolate Yersinia enterocolitica in clinical, food and environmental samples, cefsulodin-irgasan-novobiocin (CIN) and MacConkey (MAC) agars, lack the ability to differentiate potentially virulent Y. enterocolitica from other Yersinia that may be present as well as some other bacterial spp. This study proposes the use of an agar medium, Y. enterocolitica chromogenic medium (YeCM), for isolation of potentially virulent Y. enterocolitica. This agar contains cellobiose as the fermentable sugar, a chromogenic substrate and selective inhibitors for suppression of colony formation by many competing bacteria. All strains of potentially virulent Yersinia of biotypes 1B, and biotypes 2-5 formed convex, red bulls-eye colonies on YeCM that were very similar to those described for CIN agar. However, Y. enterocolitica biotype 1A and other related Yersinia formed colonies that were purple/blue on YeCM while they formed typical red bulls-eye colonies on CIN agar. When a mixture of potentially virulent Y. enterocolitica biotype 1B, Y. enterocolitica biotype 1A and 5 other bacterial species was used to artificially contaminate tofu and then spread-plated on three selective agars, Y. enterocolitica biotype 1B colonies were easily distinguished from other strains on YeCM. However, Y. enterocolitica biotype 1B colonies were indistinguishable from many other colonies on CIN and only distinguishable from those of C. freundii on MAC. When colonies were picked and identified from these agars, typical colonies from YeCM were confirmed only as Y. enterocolitica biotype 1B. Typical colonies on CIN and MAC were found to belong to several competing species and biotypes.

  19. Modified Pseudomonas agar: new differential medium for the detection/enumeration of Pseudomonas aeruginosa in mineral water.

    PubMed

    Ramalho, Rita; Cunha, Joaquim; Teixeira, Paula; Gibbs, Paul A

    2002-03-01

    Pseudomonas aeruginosa has been implicated as a foodborne and waterborne pathogen and is now considered a primary infectious agent. In the present study, the survival of P. aeruginosa inoculated in mineral water was evaluated by drop counts on Pseudomonas Agar Base (PAB), PAB with CN supplement X107, PAB with cetrimide, PAB with nalidixic acid, and these media with added FeSO(4). Initial counts, before starvation, were the same in all media tested. Following this period, P. aeruginosa became sensitive to PAB with added cetrimide. The addition of FeSO(4) did not improve the recovery of stressed P. aeruginosa but gave colonies a typical dark brown colour being easily differentiated from other species that can grow at 42 degrees C. The modified Pseudomonas agar medium was also tested with several P. aeruginosa strains, other species of Pseudomonas, and other genera. Only P. aeruginosa strains (pyocyanin positive) produced the typical colonies. Our results demonstrate that Pseudomonas agar with ferrous sulphate, used for the differentiation of P. aeruginosa colonies, and nalidixic acid, used as an inhibitor of Gram-positive bacteria, might be a useful medium for the detection of injured P. aeruginosa in mineral water. PMID:11777584

  20. [Comparison of the results of determining antibiotic sensitivity on AGV medium and on Mueller-Hinton and isosensitest agars].

    PubMed

    Kozlov, R S; Strachunskiĭ, L S; Livermor, D M; Stetsiuk, O U; Shavrikova, E P

    1996-01-01

    To evaluate the adequacy of AGV agar for antimicrobial susceptibility testing, the susceptibility of a range of bacteria to 10 antimicrobials on AGV, Mueller-Hinton and isoSensitest agars, all supplemented with 5 per cent lyzed horse blood was determined. Disc tests were used. In general, AGV agar gave identical susceptibility results to Mueller-Hinton and isoSensitest agars for common gram positive and gram negative bacteria with most of the tested microbials excluding sulphonamides and trimethoprim. With those latter antimicrobials inhibition zones for susceptible organisms were not formed on AGV agar whereas large zones were present on Mueller-Hinton and isoSensitest agars. This discrepancy probably can be explained by the presence of high levels of thymidine in AGV agar; too high to be corrected even by the addition of 5 per cent lysed horse blood. AGV agar is possible to use for susceptibility testing with most of the microbials excluding trimethoprim and sulphonamides.

  1. Comparison of inhibitory mold agar to Sabouraud dextrose agar as a primary medium for isolation of fungi.

    PubMed

    Scognamiglio, Theresa; Zinchuk, Riva; Gumpeni, Pramod; Larone, Davise H

    2010-05-01

    Clinical specimens cultured on two selective fungal media, inhibitory mold agar (IMA) and Sabouraud dextrose agar (SDA), were compared with respect to recovery of fungi. Of the 840 fungal isolates recovered, 69.3% grew on both IMA and SDA; 24.9% grew only on IMA; and 5.8% grew only on SDA, showing that IMA is superior (P=0.003).

  2. Improved method of screening for aflatoxin with a coconut agar medium.

    PubMed

    Davis, N D; Iyer, S K; Diener, U L

    1987-07-01

    Nine isolates of Aspergillus flavus and Aspergillus parasiticus were screened for aflatoxin production on a coconut extract agar medium. Aflatoxin-producing colonies were detected under long-wave UV light (365 nm) by blue fluorescence on the reverse side after 2 to 5 days of growth. Aflatoxin production was verified by chemical analysis. Several types of shredded coconut available in the United States were tested and found to be satisfactory. No additives were required. Various parameters affecting the test were investigated.

  3. Selectivity of Mitis Salivarius agar and a new selective medium for oral streptococci in dogs.

    PubMed

    Takada, Kazuko; Hayashi, Kazuhiko; Sasaki, Kayoko; Sato, Tsuneo; Hirasawa, Masatomo

    2006-09-01

    An evaluation on the applicability of Mitis Salivarius agar (MS) medium, commonly used for the detection of oral streptococci in human and animals, to dog specimens and the development of a new selective medium for isolating streptococci from the canine oral cavity are described. Oral samples from dogs were cultured on MS medium under anaerobic conditions. The predominant facultative anaerobic bacteria on MS plates were gram-negative rods. Selectivity of streptococci on MS medium was 21.2%. A new selective medium, designated MS-CAN-AE, was developed for the isolation of streptococci from the canine oral cavity. The average growth recovery of laboratory and clinically isolated strains of streptococci on MS-CAN-AE medium was 84.1% of that on MS medium. Gram-positive rods and gram-negative rods and cocci rarely grew on the MS-CAN-AE. The selectivity of MS-CAN-AE was 95.0% for clinical samples. MS-CAN-AE medium will be helpful for investigations of streptococci in the canine oral cavity.

  4. Pig and Goat Blood as Substitutes for Sheep Blood in Blood-Supplemented Agar Media

    PubMed Central

    Anand, Chandar; Gordon, Rhonda; Shaw, Helene; Fonseca, Kevin; Olsen, Merle

    2000-01-01

    In many developing countries sheep and horse blood, the recommended blood supplements in bacteriological media, are not readily available, whereas pig and goat blood are. Therefore, this study examined the use of pig and goat blood as potential substitutes for sheep blood in blood-supplemented bacteriologic media commonly used in clinical microbiology laboratories. In general, the growth characteristics and colony morphologies of a wide range of aerobic and anaerobic bacteria and Candida albicans were similar on media containing pig, goat, and sheep blood, although differences were found. Enterococcus sp. uniformly produced alpha-hemolysis when incubated in CO2, but in anaerobic conditions the hemolysis varied. In contrast, beta-hemolytic streptococci produced identical hemolytic reactions on all three media. Synergistic hemolysis was not observed on pig blood agar in the CAMP test nor on goat blood agar in the reverse CAMP test. The preparation of chocolate agar (heated) with pig blood required heating to a higher temperature than with sheep or goat blood to yield suitable growth of Haemophilus species. In general, we conclude that pig and goat blood are suitable alternatives to sheep blood for use in bacteriological media in settings where sheep and horse blood are not readily available. PMID:10655351

  5. Evaluation of a new selective chromogenic agar medium for detection of extended-spectrum beta-lactamase-producing Enterobacteriaceae.

    PubMed

    Glupczynski, Youri; Berhin, Catherine; Bauraing, Caroline; Bogaerts, Pierre

    2007-02-01

    A novel chromogenic agar medium (ESBL-Bx; bioMérieux, Marcy l'Etoile, France) was compared to MacConkey agar supplemented with 2 mg ceftazidime/liter (MCKC) for the selective isolation and presumptive identification of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae directly from clinical samples. Of a total of 644 clinical specimens (including 551 fecal samples), 496 yielded no growth and 148 yielded growth on one or both media. Overall, 44 ESBL-producing Enterobacteriaceae strains (Escherichia coli [n=17], Enterobacter aerogenes [n=17], Klebsiella spp. [n=5], and Citrobacter freundii [n=5]) were isolated from 37 specimens by a combination of both methods after 18 to 24 h of incubation. The sensitivities were 97.7 and 84.1% for ESBL-Bx and MCKC, respectively, with 43 ESBL-positive strains isolated as colored colonies from 36 specimens on ESBL-Bx versus 37 ESBL-positive organisms isolated from 32 specimens on MCKC. The specificities by specimens were 89 and 91% for ESBL-Bx and MCKC, respectively. On either one of the two media, natural AmpC-hyperproducing Enterobacter spp. (n=25) and Citrobacter spp. (n=14) were the most common false positives as well as non-ESBL-producing Klebsiella oxytoca (n=18) on ESBL-Bx and Morganella morganii (n=10) on MCKC. We conclude that ESBL-Bx is a sensitive and specific medium for the isolation of ESBL-producing Enterobacteriaceae from clinical samples. The main advantages of ESBL-Bx over MCKC reside in its chromogenic character and its sensitivity and selectivity, which enabled the recovery and presumptive identification of most ESBL-producing Enterobacteriaceae within 24 h and reduced by 27% the need for unnecessary identification and confirmation of ESBL testing when disregarding all colorless colonies growing on this medium.

  6. Agar Diffusion Procedures for Susceptibility Testing of Malassezia pachydermatis: Evaluation of Mueller-Hinton Agar Plus 2 % Glucose and 0.5 µg/ml Methylene Blue as the Test Medium.

    PubMed

    Pasquetti, M; Chiavassa, E; Tizzani, P; Danesi, P; Peano, A

    2015-10-01

    Aim of this study was to verify whether Mueller-Hinton agar supplemented with 2 % glucose and methylene blue (MH-GM), which is used for disk diffusion susceptibility testing of Candida species by the Clinical and Laboratory Standards Institute, is suitable for testing Malassezia pachydermatis. A variant of the disk diffusion procedure utilizing a 9-mm tablet was used to test 31 isolates against clotrimazole and miconazole using MH-GM as test medium. The MH-GM agar optimally supported the growth of all M. pachydermatis isolates, provided that the yeast inoculum was prepared with a lipid source (Tween 40 and 80). Zone edges were frequently definite and clear, facilitating the measurement of zone size and minimizing subjectivity. The inhibition zones correlated with MIC values obtained in a broth dilution assay. The agar diffusion method with MH-GM as the test medium appears as a suitable procedure for testing the susceptibility of M. pachydermatis to CTZ and MCZ in clinical laboratories. This test format may allow processing a large number of isolates in epidemiological studies. This may in turn facilitate clarifying to what extent the problem "drug resistance" accounts for cases of treatment failure in dogs with Malassezia otitis and dermatitis. PMID:26138434

  7. Modification of Karmali agar by supplementation with potassium clavulanate for the isolation of Campylobacter from chicken carcass rinses.

    PubMed

    Chon, Jung-Whan; Kim, Hong-Seok; Kim, Dong-Hyeon; Kim, Hyunsook; Choi, In-Soo; Oh, Deog-Hwan; Seo, Kun-Ho

    2014-07-01

    The detection ability and selectivity of Karmali agar was improved by supplementation of an extended-spectrum β-lactamase inhibitor, potassium clavulanate. The optimum concentration of potassium clavulanate (0.5 μg/ml) in Karmali agar was determined by inoculation of 50 Campylobacter and 30 extended-spectrum β-lactamase-producing E. coli strains onto normal and modified Karmali agar containing various concentrations of the agent. Eighty retail carcasses were rinsed with 400 ml of buffered peptone water. The rinse samples were enriched in 2 × blood-free Bolton enrichment broth at 42°C for 48 h and then were streaked onto normal and modified Karmali agar containing 0.5 μg/ml potassium clavulanate. The suspicious colonies were subcultured on Columbia blood agar and confirmed by colony PCR. In chicken carcass samples, the modified Karmali agar showed a significantly greater isolation rate than normal Karmali agar (42.5 versus 21.3%; P < 0.05). Furthermore, the selectivity of the modified Karmali agar was also significantly higher (P < 0.05) than that of the normal Karmali agar, as seen by comparison of the number of contaminated agar plates (83.8 versus 97.5%) and the growth index (1.67 versus 2.91) of the non-Campylobacter colonies.

  8. Evaluation of cephamycins as supplements to selective agar for detecting Campylobacter spp. in chicken carcass rinses.

    PubMed

    Chon, Jung-Whan; Kim, Young-Ji; Kim, Hong-Seok; Kim, Dong-Hyeon; Kim, Hyunsook; Song, Kwang-Young; Sung, Kidon; Seo, Kun-Ho

    2016-04-16

    Although cefoperazone is the most commonly used antibiotic in Campylobacter-selective media, the distribution of cefoperazone-resistant bacteria such as extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli is increasing. Here we evaluated the potential of cephamycins for use as supplements to improve modified charcoal-cefoperazone-deoxycholate agar (mCCDA) by replacing cefoperazone with the same concentrations (32 mg/L) of cefotetan (modified charcoal-cefotetan-deoxycholate agar, mCCtDA) and cefoxitin (modified charcoal-cefoxitin-deoxycholate agar, mCCxDA). In chicken carcass rinse samples, the number of mCCDA plates detecting for Campylobacter (18/70, 26%) was significantly lower than that of mCCtDA (42/70, 60%) or mCCxDA plates (40/70, 57%). The number of mCCDA plates (70/70, 100%) that were contaminated with non-Campylobacter species was significantly higher than that of mCCtDA (20/70, 29%) or mCCxDA plates (21/70, 30%). The most common competing species identified using mCCDA was ESBL-producing E. coli, while Pseudomonas species frequently appeared on mCCtDA and mCCxDA.

  9. [A multicenter study of a new Helicobacter pylori selective medium. Columbia horse blood agar HP].

    PubMed

    Hasegawa, Miyuki; Amano, Ayako; Muraoka, Hiroe; Kobayashi, Intetsu; Kimoto, Mami; Kato, Mototsugu; Fujioka, Toshio; Nasu, Masaru

    2002-05-01

    We conducted a study for the growth of and selectivity for the desired microorganisms using a newly developed selective culture medium for Helicobacter pylori, Columbia horse blood agar HP (CHBHP), at three different Japanese clinical laboratories, Hokkaido, Kanto and Kyusyu. When standard strains and clinical isolates of H. pylori were examined, the recovery of the organism on the CHBHP media was comparable to that of conventional selective and nonselective media. However, colonies were obviously larger on the CHBHP media. These media yielded the highest H. pylori positive rate for clinical specimens at all the three laboratories. The detection rate of the CHBHP media in H. pylori-positive specimens was higher than that of media commonly used at the three laboratories (98.1% to 100% vs. 88.0% to 96.2%). The CHBHP media also achieved a higher detection rate for specimens from H. pylori-infected animals. CHBHP media have an excellent growth supporting ability and selectivity originating from Columbia agar base and do not require the combined use of non-selective media for the growth and isolation of the organism, resulting in lower cost. Thus, they are useful media for the selective culture and isolation of H. pylori from clinical and animal specimens.

  10. Evaluation of CHROMagar™ StrepB agar, an aerobic chromogenic medium for prepartum vaginal/rectal Group B Streptococcus screening.

    PubMed

    Poisson, Didier-Marc; Evrard, Marie-Liesse; Freneaux, Claire; Vivès, Marie-isabelle; Mesnard, Louis

    2011-03-01

    An aerobic chromogenic medium, CHROMagar™ StrepB agar, designed for isolation of group B Streptococci, was evaluated on 285 prepartum vaginal/rectal swabs from pregnant women. After overnight enrichment in Todd-Hewitt broth containing 15μg/ml nalidixic acid and 10μg/ml colistin, sensitivities were respectively 79% on day 1 and 92% on day 2, and significantly higher than those achieved by blood agar (40% and 58%) and colimycin-nalidixic-acid agar (82% on day 2).

  11. Comparative evaluation of chromogenic agar medium and conventional culture system for isolation and presumptive identification of uropathogens

    PubMed Central

    Akter, Laila; Haque, Rezwana; Salam, Md. Abdus

    2014-01-01

    Objective: Urine is the most frequent specimen received for culture/sensitivity by clinical laboratories. The microbiological performance of HiCrome UTI agar medium was compared with Blood agar and MacConkey agar for isolation and presumptive identification of bacteria from urine culture. Methods: A total of 443 consecutively collected midstream and/or catheter-catch urine samples from patients attending the Islami Bank Medical College Hospital, Rajshahi, Bangladesh during January to December, 2012 were cultured. Urine samples showing pus cells ≥ 5/HPF were inoculated on to Blood agar (BA), MacConkey agar (MAC) and HiCrome UTI agar (CA) media simultaneously and incubated overnight aerobically at 370C. Rate of isolation and presumptive identification of bacterial species were compared for different media. Results: Culture yielded a total of 199 bacterial isolates from 189 (42.67%) positive plates including 179 (40.40%) unimicrobial and 10 (2.26%) polymicrobial (mixed growth of pair of bacteria) growths. Both HiCrome UTI agar and Blood agar media supported 100% growths while 151 (75.88%) growths were observed on MacConkey agar. The rate of presumptive identification was found significantly higher on HiCrome UTI agar (97.49%) than MAC agar (67.34%) (P<0.001) as primary urine culture medium. Of 199 isolates, E. coli was found to be the leading uropathogen isolated from 118 (59.30%) samples with its presumptive identification rate of 95.76%, 93.22% and 5.93% on CA, MAC and BA respectively. All 10 (100%) polymicrobial growths were demonstrated distinctly on CA against only 01(10%) on each BA and MAC. Conclusion: HiCrome UTI agar was found to be more useful as primary urine culture medium in both higher rate of isolation and presumptive identification of uropathogens in comparison to conventional media. Its inherent characteristics in demonstrating polymicrobial growth and ease of rapid identification by distinct colony colour are unique. PMID:25225521

  12. Comparison of CHROMagar Salmonella Medium and Hektoen Enteric Agar for Isolation of Salmonellae from Stool Samples

    PubMed Central

    Gaillot, Olivier; Di Camillo, Patrick; Berche, Patrick; Courcol, René; Savage, Colette

    1999-01-01

    CHROMagar Salmonella (CAS), a new chromogenic medium, was retrospectively compared to Hektoen enteric agar (HEA) with 501 Salmonella stock isolates and was then prospectively compared to HEA for the detection and presumptive identification of Salmonella spp. with 508 stool samples before and after enrichment. All stock cultures (100%), including cultures of H2S-negative isolates, yielded typical mauve colonies on CAS, while 497 (99%) isolates produced typical lactose-negative, black-centered colonies on HEA. Following overnight incubation at 37°C, a total of 20 Salmonella strains were isolated from the 508 clinical samples. Sensitivities for primary plating and after enrichment were 95% (19 isolates) and 100% (20 isolates), respectively, for CAS and 80% (16 isolates) and 100% (20 isolates), respectively, for HEA. The specificity of CAS (88.9%) was significantly higher than that of HEA (78.5%; P < 0.0001). On the basis of its good sensitivity and specificity, CAS medium can be recommended for use for primary plating when human stool samples are screened for Salmonella spp. PMID:9986847

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

    PubMed

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

    2009-03-15

    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 grown at 25 degrees C with an alternating light/dark cycle consisting of 8 h of cool-white daylight followed by 16 h darkness. Addition of 1.5% MnCl(2) 4 H(2)O (w/v) inhibited most other fungi than Alternaria, Epicoccum and Phoma species when tested on pure cultures. The mycobiota of two soil samples and eight grain samples were examined using PCA-Mn and three commonly used isolation media, DRYES, DG18 and V8. On the three conventional media growth of several genera was observed with the predominant being Aspergillus, Eurotium, Fusarium, Mucor, Penicillium and Rhizopus. Of these only F. oxysporum and F. verticillioides were able to grow on PCA-Mn. Alternaria infectoria and Epicoccum nigrum were present in three cereal grain samples, but emerged to a far lower degree on the three conventional media compared to PCA-Mn. Three black spored fungi, identified as Phoma eupyrena, Paraconiothyrium minitan and one unknown species, were isolated from the two soil samples when incubated on PCA-Mn but were absent on the three conventional media.

  14. M-RTLV agar, a novel selective medium to distinguish Lactobacillus casei and Lactobacillus paracasei from Lactobacillus rhamnosus.

    PubMed

    Sakai, Takafumi; Oishi, Kenji; Asahara, Takashi; Takada, Toshihiko; Yuki, Norikatsu; Matsumoto, Kazumasa; Nomoto, Koji; Kushiro, Akira

    2010-05-15

    We developed a novel selective medium, modified-rhamnose-2,3,5-triphenyltetrazolium chloride-LBS-vancomycin agar (M-RTLV agar), that utilizes the fermentability of L-rhamnose to distinguish Lactobacillus casei and Lactobacillus paracasei from Lactobacillus rhamnosus. Whereas L. casei and L. paracasei formed red colonies on the M-RTLV agar, L. rhamnosus formed either pink-toned colonies or white colonies with a red spot. An intervention study was conducted to confirm the capability of M-RTLV agar to detect ingested L. casei when recovered from human feces. Subjects consumed one bottle daily of a fermented milk product (Yakult or Yakult Light, which contains L. casei strain Shirota; LcS) for 7 days. Diluents of the fecal samples were cultivated on M-RTLV agar. We were able to enumerate circular medium-sized red colonies, which were morphologically similar to L. casei/L. paracasei but clearly distinguishable from the remaining colonies owing to the color difference. These colonies were then subjected to enzyme-linked immunosorbent assay in order to identify the LcS. The viable counts of LcS were 6.6+/-0.7 log(10) CFU/g feces after intake of Yakult and 6.5+/-0.6 log(10) CFU/g feces after intake of Yakult Light (mean+/-SD).

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

    PubMed Central

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

    1985-01-01

    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. PMID:3896142

  16. Cytological comparison of leaves and stems of Prunus avium L. shoots cultured on a solid medium with agar or gelrite.

    PubMed

    Franck, T; Crèvecoeur, M; Wuest, J; Greppin, H; Gaspar, T

    1998-01-01

    An axillary proliferating clone of Prunus avium L. was subcultured every four weeks on solid MS medium with agar as the gelling agent. Vitrification (hyperhydricity) of shoots was induced in one four week cycle with the same medium except that agar was replaced by gelrite. During culture on the vitrifying medium, the water content of the shoots progressively increased with a parallel decrease in chlorophyll content. Cytological differences between the leaves and stems of the vitrified and normal shoots were detected by light and electron (both transmission and scanning) microscopy. Leaves of vitrified shoots were characterized by lower number of chloroplasts in the palisade parenchyma and by a defective cuticle. The stems of vitrified shoots had a less developed and lignifled xylem tissue, lacked sclerenchymatic areas and showed hypertrophy of the cortical parenchyma. More intense vacuolar activity with evaginations of the chloroplast envelope into the vacuole was noted in cells of vitrified leaves.

  17. Malt-yeast extract-sucrose agar, a suitable medium for enumeration and isolation of fungi from silage.

    PubMed Central

    Skaar, I; Stenwig, H

    1996-01-01

    A general medium named malt-yeast extract-sucrose agar (MYSA) containing oxgall was designed. The medium was intended for the enumeration and isolation of molds and yeasts in routine examinations of animal feed stuffs. In this study MYSA was tested as a general medium for mycological examination of silage. The medium was compared with dichloran-rose bengal medium (DRBC) in an examination of more than 500 specimens of big bale grass silage. Selected characteristics of known fungal species commonly isolated from feeds were examined after growth on MYSA and DRBC and on malt extract agar, used as a noninhibitory control medium. MYSA suppressed bacterial growth, without affecting the growth of fungi common in feeds. The fungi growing on MYSA were easily recognized, and the medium seemed to slow radial growth of fungal colonies, which permitted, easy counting. The number of species found was higher on MYSA than on DRBC. When we compared MYSA with DRBC for mycological examination of grass silage samples, MYSA was found to be the medium of choice. PMID:8837416

  18. Evaluation of Brilliance ESBL agar, a novel chromogenic medium for detection of extended-spectrum-beta- lactamase-producing Enterobacteriaceae.

    PubMed

    Huang, Te-Din; Bogaerts, Pierre; Berhin, Catherine; Guisset, Amelie; Glupczynski, Youri

    2010-06-01

    The aim of this study was to evaluate the performance of Brilliance ESBL agar (OX; Oxoid, Basingstoke, United Kingdom), a novel chromogenic agar for the selective isolation and the presumptive identification of extended-spectrum-beta-lactamase (ESBL)-producing Enterobacteriaceae. A panel of 200 clinical Gram-negative Enterobacteriaceae and nonfermenting isolates with defined resistance mechanisms was inoculated onto OX and onto ChromID ESBL agar (BM; bioMérieux, Marcy l'Etoile, France) chromogenic medium in the first part of the study to evaluate the growth selectivity and chromogenic features of these two media. Of the 156 Enterobacteriaceae challenge isolates, 8 fully susceptible isolates were inhibited, all 98 ESBL producers were detected, and 50 isolates harboring other resistance mechanisms were recovered on both chromogenic agars. In the second phase, 528 clinical samples (including 344 fecal specimens) were plated onto OX, BM, and MacConkey agar with a ceftazidime disk (MCC) for the screening of ESBL-producing Enterobacteriaceae. Growth on at least one medium was observed with 144 (27%) of the clinical samples screened. A total of 182 isolates, including 109 (60%) of Enterobacteriaceae, were recovered and 70 of these (from 59 specimens) were confirmed as ESBL-producing isolates. The sensitivities of MCC, BM, and OX were 74.6%, 94.9%, and 94.9%, respectively. The specificities of MCC, BM, and OX by specimens reached 94.9%, 95.5%, and 95.7%, respectively, when only colored colonies were considered on the two selective chromogenic media. The high negative predictive value (99.3%) found for OX suggests that this medium may constitute an excellent screening tool for the rapid exclusion of patients not carrying ESBL producers.

  19. Description of Leeds Acinetobacter Medium, a new selective and differential medium for isolation of clinically important Acinetobacter spp., and comparison with Herellea agar and Holton's agar.

    PubMed Central

    Jawad, A; Hawkey, P M; Heritage, J; Snelling, A M

    1994-01-01

    Acinetobacter spp. are responsible for an increasing number of opportunistic, nosocomial infections. They have been isolated from diverse inanimate objects in the hospital environment and are resistant to most of the commonly used antibiotics. Existing media for the isolation of Acinetobacter spp. are either nonselective, allowing the growth of unwanted bacteria, or too inhibitory, inhibiting the growth of many Acinetobacter strains. For the rapid isolation and effective control of Acinetobacter infection, a new selective and differential medium, Leeds Acinetobacter Medium (LAM), has been developed to isolate Acinetobacter spp. from clinical and environmental sources. The concentration of antibiotics and other ingredients in this medium have been determined according to the results of MIC and viable counts performed for these ingredients. LAM was compared with other selective and differential media for the isolation of Acinetobacter spp. from a local hospital environment and proved to be better in terms of recovery and selectivity. PMID:7814465

  20. Development of a selective myclobutanil agar (MBA) medium for the isolation of Fusarium species from asparagus fields.

    PubMed

    Vujanovic, Vladimir; Hamel, Chantal; Jabaji-Hare, Suha; St-Arnaud, Marc

    2002-09-01

    A new selective myclobutanil agar medium for the detection of Fusarium, species is proposed. Ten media formulations based on various selective agents (pentachloronitrobenzene (PCNB), Rose Bengal, malachite green, sodium hypochlorite, captan, benomyl, chlorotalonil, myclobutanil, thiram, and cupric sulfate) were compared. First, mycelium growth and colony appearance of Alternaria alternata, Aspergillus flavus, Cladosporium cladosporioides, Epicoccum nigrum, Fusarium sp., Fuisarium solani, Fusarium moniliforme, Fusarium oxysporum f.sp. dianthi, Penicillium sp., and Trichoderma viride isolates were compared. Second, the ability of the different media to isolate and enumerate fusaria from asparagus fields was evaluated. The myclobutanil-based medium showed the highest selectivity to Fusarium spp. growth but required a slightly longer incubation time (>5 d) than peptone-pentachloronitrobenzene-based agar (PPA) (< 5 d). PPA allowed a faster fusaria growth but also permited the growth of other moulds. The other media were less selective and did not allow to isolate fusaria or to differenciate them from other growing fungi.

  1. As a bacterial culture medium, citrated sheep blood agar is a practical alternative to citrated human blood agar in laboratories of developing countries.

    PubMed

    Russell, F M; Biribo, S S N; Selvaraj, G; Oppedisano, F; Warren, S; Seduadua, A; Mulholland, E K; Carapetis, J R

    2006-09-01

    Human blood agar (HuBA) is widely used in developing countries for the isolation of bacteria from clinical specimens. This study compared citrated sheep blood agar (CSBA) and HuBA with defibrinated horse blood agar and defibrinated sheep blood agar (DSBA) for the isolation and antibiotic susceptibility testing of reference and clinical strains of Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus. Reference and clinical strains of all organisms were diluted in brain heart infusion and a clinical specimen of cerebrospinal fluid and cultured on all agars. Viable counts, colony morphology, and colony size were recorded. Susceptibility testing for S. pneumoniae and S. pyogenes was performed on defibrinated sheep blood Mueller-Hinton agar, citrated sheep blood Mueller-Hinton agar (CSB MHA), and human blood Mueller-Hinton agar plates. For all organisms, the colony numbers were similar on all agars. Substantially smaller colony sizes and absent or minimal hemolysis were noted on HuBA for all organisms. Antibiotic susceptibility results for S. pneumoniae were similar for the two sheep blood agars; however, larger zone sizes were displayed on HuBA, and quality control for the reference strain failed on HuBA. For S. pyogenes, larger zone sizes were demonstrated on HuBA and CSBA than on DSBA. Poor hemolysis made interpretation of the zone sizes difficult on HuBA. CSBA is an acceptable alternative for the isolation of these organisms. The characteristic morphology is not evident, and hemolysis is poor on HuBA; and so HuBA is not recommended for use for the isolation or the susceptibility testing of any of these organisms. CSB MHA may be suitable for use for the susceptibility testing of S. pneumoniae.

  2. Sheep blood-LB agar base medium (SLM) as a simple and suitable medium for the cultivation of Leishmania major promastigotes.

    PubMed

    Nasiri, Vahid

    2013-11-01

    Several methods of cultivation of Leishmania parasites are available, and among them, biphasic media like Nicolle-Novy-MacNeal medium are considered to be superior for the initial isolation of the parasites and their in vivo infectivity. In the present work, the efficacy of sheep blood-LB agar base medium (SLM) was evaluated for the cultivation of Leishmania major promastigotes. The SLM supports the proliferation of the parasites and can be used for routine isolation and cultivation of Leishmania parasites with acceptable in vivo infectivity for research purposes.

  3. Use of citrate adonitol agar as a selective medium for the isolation of Escherichia fergusonii from a captive reindeer herd.

    PubMed

    Foster, Geoffrey; Evans, Judith; Tryland, Morten; Hollamby, Simon; MacArthur, Isabel; Gordon, Emma; Harley, Jane; Voigt, Katja

    2010-08-26

    Escherichia fergusonii is an emerging potentially zoonotic organism which has been recovered from a broad range of human and animal sources. Efforts to recover E. fergusonii from mixed flora hitherto however have been constrained by the lack of a suitable selective medium for its isolation. This paper reports for the first time the recovery of E. fergusonii from reindeer carcases in a wildlife park and the use of citrate adonitol agar to selectively screen for the presence of this organism in faecal samples from further animals in the park, and reindeer in their natural habitat in Norway.

  4. Comparison of the BBL CHROMagar Staph aureus Agar Medium to Conventional Media for Detection of Staphylococcus aureus in Respiratory Samples

    PubMed Central

    Flayhart, Diane; Lema, Clara; Borek, Anita; Carroll, Karen C.

    2004-01-01

    Screening for Staphylococcus aureus has become routine in certain patient populations. This study is the first clinical evaluation of the BBL CHROMagar Staph aureus agar (CSA) medium (BD Diagnostics, Sparks, Md.) for detection of S. aureus in nasal surveillance cultures and in respiratory samples from cystic fibrosis (CF) patients. S. aureus colonies appear mauve on CSA. Other organisms are inhibited or produce a distinctly different colony color. S. aureus was identified from all media by slide coagulase, exogenous DNase, and mannitol fermentation assays. Susceptibility testing was performed using the agar dilution method. A total of 679 samples were evaluated. All samples were inoculated onto CSA. Nasal surveillance cultures were inoculated onto sheep blood agar (SBA) (BD Diagnostics), and samples from CF patients were inoculated onto mannitol salt agar (MSA) (BD Diagnostics). Of the 679 samples cultured, 200 organisms produced a mauve color on CSA (suspicious for S. aureus) and 180 were positive for S. aureus on SBA or MSA. Of 200 CSA-positive samples 191 were identified as S. aureus. Nine mauve colonies were slide coagulase negative and were subsequently identified as Staphylococcus lugdunensis (one), Staphylococcus epidermidis (three), Staphylococcus haemolyticus (one), and Corynebacterium species (four). CSA improved the ability to detect S. aureus by recovering 12 S. aureus isolates missed by conventional media. Of the 192 S. aureus isolates recovered, 122 were methicillin susceptible and 70 were methicillin resistant. Overall, the sensitivity and specificity of CSA in this study were 99.5 and 98%, respectively. There was no difference in the performance of the slide coagulase test or in susceptibility testing performed on S. aureus recovered from CSA compared to SBA or MSA. Our data support the use of CSA in place of standard culture media for detection of S. aureus in heavily contaminated respiratory samples. PMID:15297498

  5. Comparison of the BBL CHROMagar Staph aureus agar medium to conventional media for detection of Staphylococcus aureus in respiratory samples.

    PubMed

    Flayhart, Diane; Lema, Clara; Borek, Anita; Carroll, Karen C

    2004-08-01

    Screening for Staphylococcus aureus has become routine in certain patient populations. This study is the first clinical evaluation of the BBL CHROMagar Staph aureus agar (CSA) medium (BD Diagnostics, Sparks, Md.) for detection of S. aureus in nasal surveillance cultures and in respiratory samples from cystic fibrosis (CF) patients. S. aureus colonies appear mauve on CSA. Other organisms are inhibited or produce a distinctly different colony color. S. aureus was identified from all media by slide coagulase, exogenous DNase, and mannitol fermentation assays. Susceptibility testing was performed using the agar dilution method. A total of 679 samples were evaluated. All samples were inoculated onto CSA. Nasal surveillance cultures were inoculated onto sheep blood agar (SBA) (BD Diagnostics), and samples from CF patients were inoculated onto mannitol salt agar (MSA) (BD Diagnostics). Of the 679 samples cultured, 200 organisms produced a mauve color on CSA (suspicious for S. aureus) and 180 were positive for S. aureus on SBA or MSA. Of 200 CSA-positive samples 191 were identified as S. aureus. Nine mauve colonies were slide coagulase negative and were subsequently identified as Staphylococcus lugdunensis (one), Staphylococcus epidermidis (three), Staphylococcus haemolyticus (one), and Corynebacterium species (four). CSA improved the ability to detect S. aureus by recovering 12 S. aureus isolates missed by conventional media. Of the 192 S. aureus isolates recovered, 122 were methicillin susceptible and 70 were methicillin resistant. Overall, the sensitivity and specificity of CSA in this study were 99.5 and 98%, respectively. There was no difference in the performance of the slide coagulase test or in susceptibility testing performed on S. aureus recovered from CSA compared to SBA or MSA. Our data support the use of CSA in place of standard culture media for detection of S. aureus in heavily contaminated respiratory samples.

  6. Biological and chemical detection of fumonisins produced on agar medium by Fusarium verticillioides isolates collected from corn in Sohag, Egypt.

    PubMed

    Aboul-Nasr, M B; Obied-Allah, M R A

    2013-08-01

    Fusarium verticillioides (Sacc.) Nirenberg is among the most common Fusarium species corn pathogens worldwide, and has been recognized as a fumonisin B1 (FB1) and fumonisin B2 (FB2) producer. In the present work, extracts of 58 F. verticillioides isolates from corn samples collected from Sohag Governorate, Egypt, were tested for their biotoxicity and production of fumonisin toxins. Forty-four Fusarium verticillioides isolates out of 58 tested produced FB1 or FB1 and FB2 (15 and 29 isolates, respectively) on potato-sucrose agar medium, detected by TLC, whereas the other 14 isolates did not produce fumonisin toxins. HPLC crude extract analysis confirmed the results from TLC plates. Brine shrimp larvae as well as the Gram-negative bacteria Pseudomonas aeuroginosa showed low bio-sensitivity towards the F. verticillioides crude extract toxicity, whereas the Gram-positive bacteria Bacillus cereus and Bacillus subtilis, especially B. subtilis, showed higher sensitivity towards the tested Fusarium crude extracts. These results enabled us to bio-evaluate and chemically detect fumonisin mycotoxins using a simple agar medium technique. PMID:23760819

  7. Biological and chemical detection of fumonisins produced on agar medium by Fusarium verticillioides isolates collected from corn in Sohag, Egypt.

    PubMed

    Aboul-Nasr, M B; Obied-Allah, M R A

    2013-08-01

    Fusarium verticillioides (Sacc.) Nirenberg is among the most common Fusarium species corn pathogens worldwide, and has been recognized as a fumonisin B1 (FB1) and fumonisin B2 (FB2) producer. In the present work, extracts of 58 F. verticillioides isolates from corn samples collected from Sohag Governorate, Egypt, were tested for their biotoxicity and production of fumonisin toxins. Forty-four Fusarium verticillioides isolates out of 58 tested produced FB1 or FB1 and FB2 (15 and 29 isolates, respectively) on potato-sucrose agar medium, detected by TLC, whereas the other 14 isolates did not produce fumonisin toxins. HPLC crude extract analysis confirmed the results from TLC plates. Brine shrimp larvae as well as the Gram-negative bacteria Pseudomonas aeuroginosa showed low bio-sensitivity towards the F. verticillioides crude extract toxicity, whereas the Gram-positive bacteria Bacillus cereus and Bacillus subtilis, especially B. subtilis, showed higher sensitivity towards the tested Fusarium crude extracts. These results enabled us to bio-evaluate and chemically detect fumonisin mycotoxins using a simple agar medium technique.

  8. Supplementation of CHROMagar Candida Medium with Pal's Medium for Rapid Identification of Candida dubliniensis

    PubMed Central

    Sahand, Ismail H.; Moragues, María D.; Eraso, Elena; Villar-Vidal, María; Quindós, Guillermo; Pontón, José

    2005-01-01

    CHROMagar Candida medium is used for the isolation and identification of Candida species, but it does not differentiate Candida albicans from Candida dubliniensis. This differentiation can be achieved by using Pal's agar, which cannot be used in primary isolation. We have combined both media to obtain a new medium that can be used for the isolation and identification of C. dubliniensis in primary cultures. PMID:16272515

  9. Usefulness of Chromogenic CromoCen® AGN agar medium for the identification of the genus Aeromonas: Assessment of faecal samples.

    PubMed

    Aguilera-Arreola, M G; Portillo-Muñoz, M I; Rodríguez-Martínez, C; Castro-Escarpulli, G

    2012-08-01

    Selective screening media for the detection and identification of Aeromonas strains are needed to guide primary isolation procedures in the clinical laboratory. This study compared the selective CromoCen® AGN chromogenic agar medium for the detection and identification of Aeromonas strains that were isolated from various samples against the conventional selective agar media that are commonly used for the isolation of this organism in food, environmental and clinical samples. The Miles and Misra and ecometric methods were used to evaluate the microbiological performance of CromoCen® AGN chromogenic agar medium, which was shown to be satisfactory. A total of 14 reference Aeromonas strains, 44 wild strains and 106 clinical stool specimens were examined using both non-chromogenic selective agars that are commonly used for Aeromonas isolation and CromoCen® AGN agar. The latter exhibited 94.73% sensitivity and 100% specificity for the various samples. On CromoCen® AGN agar medium, Aeromonas formed colonies with light green, greenish and salmon pigments with or without a surrounding wide transparent zone (halo) of 2-3mm in diameter around the entire border. This medium is recommended for the isolation and potential identification of the Aeromonas genus.

  10. Cryptococcuria as manifestation of disseminated cryptococcosis: Staib agar as a selective identification medium.

    PubMed

    Severo, C B; Pinto, G L F; Sotilli, J; Garcia, M R; Gazzoni, A F; Oliveira, F M; Severo, L C

    2011-11-01

    We conducted a retrospective study of 58 cases of cryptococcosis (1986-2008) with urine test positive for Cryptococcus sp, in Mycology Laboratory, Santa Casa-Hospital Complex, Porto Alegre, RS, Brazil. The diagnosis of cryptococcuria was based on microscopic examination and culture of urinary sediment. Cryptococcus was isolated from other clinical specimens such as blood, cerebrospinal fluid, ascitic and pleural fluids, respiratory secretions, biopsies of skin, nasal and bone marrow. Cryptocccus neoformans was present in 55 cases and Cryptocccus gattii in three cases. Males predominated (79.3%); age ranged from 12 to 86 years. Acquired Immune Deficiency Syndrome (AIDS) were present in 60.3%, 31.1% did not have AIDS and 5.2% were apparently immunocompetent patients. The most frequent signs and symptoms were headache (53.4%) and fever (51.7%). The most widely used medication was the amphotericin B (43 patients). The mortality rate was 45%. We conclude that the mycological examination of the urine can be an alternative simple, non-invasive and useful in diagnosis of disseminated cryptococcosis, especially when used in conjunction with techniques for demonstration of the capsule (nigrosine) and/or production of melanin in special culture media (Staib agar).

  11. Methicillin-Resistant Staphylococcus aureus Grown on Vancomycin-Supplemented Screening Agar Displays Enhanced Biofilm Formation.

    PubMed

    Chang, Wenjiao; Ding, Ding; Zhang, Shanshan; Dai, Yuanyuan; Pan, Qing; Lu, Huaiwei; Luo, Qingli; Shen, Jilong; Ma, Xiaoling

    2015-12-01

    Brain heart infusion agar containing 3 mg/liter vancomycin (BHI-V3) was used to screen for heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA). There was markedly greater biofilm formation by isolates that grew on BHI-V3 than by strains that did not grow on BHI-V3. Increased biofilm formation by hVISA may be mediated by FnbA- and polysaccharide intercellular adhesin-dependent pathways, and upregulation of atlA and sarA may also contribute to enhanced biofilm formation by hVISA upon prolonged exposure to vancomycin.

  12. Methicillin-Resistant Staphylococcus aureus Grown on Vancomycin-Supplemented Screening Agar Displays Enhanced Biofilm Formation.

    PubMed

    Chang, Wenjiao; Ding, Ding; Zhang, Shanshan; Dai, Yuanyuan; Pan, Qing; Lu, Huaiwei; Luo, Qingli; Shen, Jilong; Ma, Xiaoling

    2015-12-01

    Brain heart infusion agar containing 3 mg/liter vancomycin (BHI-V3) was used to screen for heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA). There was markedly greater biofilm formation by isolates that grew on BHI-V3 than by strains that did not grow on BHI-V3. Increased biofilm formation by hVISA may be mediated by FnbA- and polysaccharide intercellular adhesin-dependent pathways, and upregulation of atlA and sarA may also contribute to enhanced biofilm formation by hVISA upon prolonged exposure to vancomycin. PMID:26459889

  13. A Chlorhexidine- Agar Plate Culture Medium Protocol to Complement Standard Broth Culture of Mycobacterium tuberculosis

    PubMed Central

    Asmar, Shady; Chatellier, Sonia; Mirande, Caroline; van Belkum, Alex; Canard, Isabelle; Raoult, Didier; Drancourt, Michel

    2016-01-01

    The culture of Mycobacterium tuberculosis using parallel inoculation of a solid culture medium and a liquid broth provides the gold standard for the diagnosis of tuberculosis. Here, we evaluated a chlorhexidine decontamination-MOD9 solid medium protocol versus the standard NALC-NaOH-Bactec 960 MGIT protocol for the diagnosis of pulmonary tuberculosis by culture. Three-hundred clinical specimens comprising 193 sputa, 30 bronchial aspirates, 10 broncho-alveolar lavages, 47 stools, and 20 urines were prospectively submitted for the routine diagnosis of tuberculosis. The contamination rates were 5/300 (1.7%) using the MOD9 protocol and 17/300 (5.7%) with the Bactec protocol, respectively (P < 0.05, Fisher exact test). Of a total of 50 Mycobacterium isolates (48 M. tuberculosis and two Mycobacterium abscessus) were cultured. Out of these 50, 48 (96%) isolates were found using the MOD9 protocol versus 35 (70%) when using the Bactec protocol (P < 0.05, Fisher exact test). The time to positivity was 10.1 ± 3.9 days versus 14.7 ± 7.3 days, respectively, (P < 0.05, Student’s t-test). These data confirmed the usefulness of parallel inoculation of a solid culture medium with broth for the recovery of M. tuberculosis in agreement with current recommendations. More specifically, chlorhexidine decontamination and inoculation of the MOD9 solid medium could be proposed to complement the standard Bactec 960 MGIT broth protocol. PMID:26834733

  14. A Chlorhexidine- Agar Plate Culture Medium Protocol to Complement Standard Broth Culture of Mycobacterium tuberculosis.

    PubMed

    Asmar, Shady; Chatellier, Sonia; Mirande, Caroline; van Belkum, Alex; Canard, Isabelle; Raoult, Didier; Drancourt, Michel

    2016-01-01

    The culture of Mycobacterium tuberculosis using parallel inoculation of a solid culture medium and a liquid broth provides the gold standard for the diagnosis of tuberculosis. Here, we evaluated a chlorhexidine decontamination-MOD9 solid medium protocol versus the standard NALC-NaOH-Bactec 960 MGIT protocol for the diagnosis of pulmonary tuberculosis by culture. Three-hundred clinical specimens comprising 193 sputa, 30 bronchial aspirates, 10 broncho-alveolar lavages, 47 stools, and 20 urines were prospectively submitted for the routine diagnosis of tuberculosis. The contamination rates were 5/300 (1.7%) using the MOD9 protocol and 17/300 (5.7%) with the Bactec protocol, respectively (P < 0.05, Fisher exact test). Of a total of 50 Mycobacterium isolates (48 M. tuberculosis and two Mycobacterium abscessus) were cultured. Out of these 50, 48 (96%) isolates were found using the MOD9 protocol versus 35 (70%) when using the Bactec protocol (P < 0.05, Fisher exact test). The time to positivity was 10.1 ± 3.9 days versus 14.7 ± 7.3 days, respectively, (P < 0.05, Student's t-test). These data confirmed the usefulness of parallel inoculation of a solid culture medium with broth for the recovery of M. tuberculosis in agreement with current recommendations. More specifically, chlorhexidine decontamination and inoculation of the MOD9 solid medium could be proposed to complement the standard Bactec 960 MGIT broth protocol. PMID:26834733

  15. Polymyxin-coagulase-mannitol-agar. I. A selective isolation medium for coagulase-positive Staphylococci.

    PubMed

    Orth, D S; Anderson, A W

    1970-01-01

    A selective, differential plating medium was developed for the isolation and identification of coagulase-positive and mannitol-fermenting staphylococci. Coagulase produced by growing Staphylococcus aureus caused an opaque zone of fibrin to form around each colony. Several strains of S. aureus produced a visible coagulase reaction by 8 hr, and all strains gave a positive reaction before 12 hr. Mannitol fermentation was usually observed between 12 and 36 hr. Rabbit serum was filtered through Sephadex G-100 to obtain plasmin- and plasminogen-free coagulase-reacting factor (CRF). False-negative reactions, caused by staphylokinase and staphylococcal Müller factor action on plasminogen, were eliminated when this CRF was used. False-positive reactions by lipolytic, coagulase-negative staphylococci were reduced, since gel filtration removed the serum lipoprotein which served as a primary source of opacity. The addition of 75 mug of polymyxin B per ml selectively retarded the growth of S. epidermidis and minimized false-positive reactions caused by citrate-utilizing gram-negative rods. The preparation, characteristics, and use of the medium are presented.

  16. Evaluation of Tazobactam-Supplemented, Modified Charcoal-Cefoperazone-Deoxycholate Agar for Qualitative Detection of Campylobacter from Chicken Carcass Rinse.

    PubMed

    Chon, Jung-Whan; Kim, Young-Ji; Kim, Hong-Seok; Kim, Dong-Hyeon; Jeong, Dong Kwan; Seo, Kun-Ho

    2016-05-01

    Overgrowth of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli on modified charcoal-cefoperazone-deoxycholate agar (mCCDA) is the most common confounding factor for the isolation of Campylobacter from poultry samples. mCCDA modified by supplementation with tazobactam, an ESBL inhibitor, was evaluated for Campylobacter isolation from chicken carcass rinse with regard to isolation rate and selectivity. In total, 120 whole chicken carcasses purchased from retail stores were rinsed with buffered peptone water enriched with 2× blood-free Bolton broth at 42°C for 48 h and then inoculated onto mCCDA with and without tazobactam supplementation (mCCDA or T-mCCDA) at 42°C for 48 h under microaerobic conditions. Suspect colonies were subcultured and confirmed by colony PCR. Plates with tazobactam exhibited a higher Campylobacter isolation rate (56.7% vs. 30.8%, p < 0.05) and selectivity (0.8 vs. 83.3% plates contaminated with non-Campylobacter, p < 0.05) than mCCDA. Thus, tazobactam-supplemented mCCDA would be a useful option for qualitative detection of Campylobacter in chicken carcass rinse.

  17. Rhamnolipid-dependent spreading growth of Pseudomonas aeruginosa on a high-agar medium: marked enhancement under CO2-rich anaerobic conditions.

    PubMed

    Nozawa, Takashi; Tanikawa, Taichiro; Hasegawa, Hiroyuki; Takahashi, Chihiro; Ando, Yumi; Matsushita, Mitsugu; Nakagawa, Yoji; Matsuyama, Tohey

    2007-01-01

    Anaerobiosis of Pseudomonas aeruginosa in infected organs is now gaining attention as a unique physiological feature. After anaerobic cultivation of P. aeruginosa wild type strain PAO1 T, we noticed an unexpectedly expanding colony on a 1.5% agar medium. The basic factors involved in this spreading growth were investigated by growing the PAO1 T strain and its isogenic mutants on a Davis high-agar minimal synthetic medium under various experimental conditions. The most promotive environment for this spreading growth was an O(2)-depleted 8% CO(2) condition. From mutational analysis of this spreading growth, flagella and type IV pili were shown to be ancillary factors for this bacterial activity. On the other hand, a rhamnolipid-deficient rhlA mutant TR failed to exhibit spreading growth on a high-agar medium. Complementation of the gene defect of the mutant TR with a plasmid carrying the rhlAB operon resulted in the restoration of the spreading growth. In addition, an external supply of rhamnolipid or other surfactants (surfactin from Bacillus subtilis or artificial product Tween 80) also restored the spreading growth of the mutant TR. Such activity of surfactants on bacterial spreading on a hard-agar medium was unique to P. aeruginosa under CO(2)-rich anaerobic conditions.

  18. Evaluation of potassium-clavulanate-supplemented modified charcoal-cefoperazone-deoxycholate agar for enumeration of Campylobacter in chicken carcass rinse.

    PubMed

    Chon, Jung-Whan; Kim, Hong-Seok; Kim, Hyunsook; Oh, Deog-Hwan; Seo, Kun-Ho

    2014-05-01

    Potassium-clavulanate-supplemented modified charcoal-cefoperazone-deoxycholate agar (C-mCCDA) that was described in our previous study was compared with original mCCDA for the enumeration of Campylobacter in pure culture and chicken carcass rinse. The quantitative detection of viable Campylobacter cells from a pure culture, plated on C-mCCDA, is statistically similar (P > 0.05) to mCCDA. In total, 120 chickens were rinsed using 400 mL buffered peptone water. The rinses were inoculated onto C-mCCDA and mCCDA followed by incubation at 42 °C for 48 h. There was no statistical difference between C-mCCDA (45 of 120 plates; mean count, 145.5 CFU/mL) and normal mCCDA (46 of 120 plates; mean count, 160.8 CFU/mL) in the isolation rate and recovery of Campylobacter (P > 0.05) from chicken carcass rinse. The Pearson correlation coefficient value for the number of Campylobacter cells recovered in the 2 media was 0.942. However, the selectivity was much better on C-mCCDA than on mCCDA plates (P < 0.05). Significantly fewer C-mCCDA plates (33 out of 120 plates; mean count, 1.9 CFU/mL) were contaminated with non-Campylobacter cells than the normal mCCDA plates (67 out of 120 plates; mean count, 27.1 CFU/mL). The C-mCCDA may provide improved results for enumeration of Campylobacter in chicken meat alternative to mCCDA with its increased selectivity the modified agar possess.

  19. Comparative evaluation of a chromogenic agar medium-PCR protocol with a conventional method for isolation of Vibrio parahaemolyticus strains from environmental and clinical samples.

    PubMed

    Canizalez-Roman, Adrian; Flores-Villaseñor, Héctor; Zazueta-Beltran, Jorge; Muro-Amador, Secundino; León-Sicairos, Nidia

    2011-02-01

    Screening for pathogenic Vibrio parahaemolyticus has become routine in certain areas associated with food-borne outbreaks. This study is an evaluation of the CHROMagar Vibrio (CV) medium-PCR protocol and the conventional method (TCBS (thiosulfate-citrate-bile salts-sucrose) agar plus biochemical and Wagatsuma agar tests) for detection of V. parahaemolyticus in shrimp, water, sediment, and stool samples collected for biosurveillance in an endemic area of northwestern Mexico. A total of 131 environmental and clinical samples were evaluated. The CV medium-PCR protocol showed a significantly improved ability (P < 0.05) to isolate and detect V. parahaemolyticus, identifying isolates of this bacteria missed by the conventional method. Although some other bacteria, distinct from pathogenic V. parahaemolyticus, produced violet colonies similar to that of V. parahaemolyticus on CV medium, we were able to detect a superior number of samples of V. parahaemolyticus with the CV medium-PCR protocol than with the conventional method. The Kanagawa phenomenon is routinely determined on Wagatsuma agar for the diagnosis of V. parahaemolyticus (pathogenic) positive for thermostable direct hemolysin (TDH) in developing countries. In our results, Wagatsuma agar showed low sensitivity (65.4% at 24 h and 75.6% at 48 h) and specificity (52.4% at 48 h) for identifying V. parahaemolyticus positive for TDH. Overall, our data support the use of the CV medium-PCR protocol in place of the conventional method (TCBS-biochemical tests-Wagatsuma agar) for detection of pathogenic V. parahaemolyticus, both in terms of effectiveness and cost efficiency.

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

    PubMed

    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.

  1. Performance of CHROMagar Selective Medium and Oxacillin Resistance Screening Agar Base for Identifying Staphylococcus aureus and Detecting Methicillin Resistance

    PubMed Central

    Kluytmans, Jan; Van Griethuysen, Arjanne; Willemse, Piet; Van Keulen, Peter

    2002-01-01

    Two new selective media, oxacillin resistance screening agar base (ORSAB) and CHROMagar Staph aureus (CSA), were evaluated for identification of Staphylococcus aureus and for screening of methicillin resistance by addition of antimicrobial agents to these media. A well-defined collection consisting of 1,140 staphylococci was used. A total of 624 were S. aureus, of which 358 were methicillin susceptible and 266 were methicillin resistant, and 516 were coagulase-negative staphylococci. The methicillin-resistant S. aureus (MRSA) strains were selected based on the results of phage typing; 247 different types were included in the analysis. For identification of S. aureus, both media performed better after 24 h than after 48 h. The sensitivities at 24 h were comparable (CSA, 98.6%; ORSAB, 97.1%), but the specificity of CSA was significantly higher (CSA, 97.1%; ORSAB, 92.1%). For screening of methicillin resistance, antibiotic supplements were added to both media. The sensitivity was lower after 24 h (CSA, 58.6%; ORSAB, 84.2%) and increased significantly after 48 h (CSA, 77.5%; ORSAB, 91.4%). At both time intervals ORSAB was significantly more sensitive than CSA. However, the specificities of both media were high after 24 h (CSA, 99.1%; ORSAB, 98.3%) and decreased significantly after 48 h of incubation (CSA, 94.7%; ORSAB, 95.5%). In conclusion, for identification of S. aureus, CSA is more accurate than ORSAB because of a significantly higher specificity. For screening of MRSA, ORSAB performs better than CSA, but the usefulness in clinical practice is limited because a significant number of strains are not detected. PMID:12089266

  2. A comparison of the performance of cystine lactose electrolyte deficient (CLED) agar with Oxoid chromogenic urinary tract infection (CUTI) medium for the isolation and presumptive identification of organisms from urine

    PubMed Central

    Fallon, D; Andrews, N; Frodsham, D; Gee, B; Howe, S; Iliffe, A; Nye, K J; Warren, R E

    2002-01-01

    Aims: As part of the UK antimicrobial resistance strategy and action plan, the Public Health Laboratory Service (PHLS) is required to collect antibiotic susceptibility data so that resistance trends and patterns can be monitored. Most laboratories report urine Gram negative isolates, as “coliforms” according to morphological appearance, but without an acceptable identification system the antimicrobial surveillance data will be meaningless. Commercially available identification systems tend to be expensive and time consuming. Chromogenic agars, which claim to improve the detection of mixed cultures and identification of organisms from urine, have now become available and may provide a cost effective alternative. The primary aim of this study was to compare the performance of cystine lactose electrolyte deficient (CLED) agar with a chromogenic agar (Oxoid urinary tract infection medium; CUTI) in terms of isolation rates and ability to detect mixed cultures. Secondary aims were to evaluate the correlation of “presumptive” identification of isolates from chromogenic media with that of two commercial identification systems and to appraise the sensitivity of the semiquantitative loop and filter paper strip culture techniques. Method: One thousand, four hundred and sixty six urine samples were examined in four laboratories using the semiquantitative culture methods of 1 μl loop and filter paper strip. The degree of accuracy of organism identification was measured by comparing the presumptive identification using colony colour supplemented with simple bench tests, with identification obtained from two more complex commercial systems. Results: There was no significant difference between the performance of the loop and filter paper strip methods on the CLED agar, but the CUTI agar performed significantly better than the CLED agar for the detection of significant isolates and mixed cultures. This difference was greater using the loop method. Identification of the

  3. Interplanetary medium data book: Supplement 3A, 1977-1985

    NASA Technical Reports Server (NTRS)

    Couzens, David A.; King, Joseph H.

    1986-01-01

    Supplement 3 of the Interplanetary Medium Data Book contains a detailed discussion of a data set compilation of hourly averaged interplanetary plasma and magnetic field parameters. The discussion addresses data sources, systematic and random differences, time shifting of ISEE 3 data, and plasma normalizations. Supplement 3 also contains solar rotation plots of field and plasma parameters. Supplement 3A contains computer-generated listings of selected parameters from the composite data set. These parameters are bulk speed (km/sec), density (per cu cm), temperature (in units of 1000 K) and the IMF parameters: average magnitude, latitude and longitude angles of the vector made up of the average GSE components, GSM Cartesian components, and the vector standard deviation. The units of field magnitude, components, and standard deviation are gammas, while the units of field direction angles and degrees.

  4. Comparison of CHROMagar Salmonella Medium and Xylose-Lysine-Desoxycholate and Salmonella-Shigella Agars for Isolation of Salmonella Strains from Stool Samples

    PubMed Central

    Maddocks, Susan; Olma, Tom; Chen, Sharon

    2002-01-01

    The growth and appearance of 115 stock Salmonella isolates on a new formulation of CHROMagar Salmonella (CAS) medium were compared to those on xylose-lysine-desoxycholate agar (XLD), Salmonella-Shigella agar (SS), and Hektoen enteric agar (HEA) media. CAS medium was then compared prospectively to XLD and SS for the detection and presumptive identification of Salmonella strains in 500 consecutive clinical stool samples. All stock Salmonella isolates produced typical mauve colonies on CAS medium. Nine Salmonella strains were isolated from clinical specimens. The sensitivities for the detection of salmonellae after primary plating on CAS medium and the combination of XLD and SS after enrichment were 100%. The specificity for the detection of salmonellae after primary plating on CAS medium (83%) was significantly (P < 0.0001) higher than that after primary plating on the combination of SS and XLD media (55%) (a 28% difference in rates; 95% confidence interval, 23.0 to 34%). Twenty-nine non-Salmonella organisms produced mauve colonies on CAS medium, including 17 Candida spp. (59%) and 8 Pseudomonas spp. (28%). These were easily excluded as salmonellae by colony morphology, microscopic examination of a wet preparation, or oxidase testing. One biochemically inert Escherichia coli isolate required further identification to differentiate it from Salmonella spp. The use of plating on CAS medium demonstrated high levels of sensitivity and specificity and reduced the time to final identification of Salmonella spp., resulting in substantial cost savings. It can be recommended for use for the primary isolation of Salmonella spp. from stool specimens. Other media (e.g., XLD) are required to detect Shigella spp. concurrently. PMID:12149365

  5. Inhibition of Streptococcus mutans strains by different mitis-salivarius agar preparations.

    PubMed Central

    Staat, R H

    1976-01-01

    Several Streptococcus mutans strains were markedly inhibited by mitis-salivarius agar manufactured by Baltimore Biological Laboratories, but little, if any, inhibition was noted using Difco Laboratories' mitis-salivarius agar. Supplementation of the basic medium with sucrose and bacitracin for specific selection of S. mutans resulted in suppression of representative S. mutans type a strains regardless of manufacturer. PMID:1270597

  6. [Detection of TDH-producing Vibrio parahaemolyticus O3:K6 from naturally contaminated shellfish using an immunomagnetic separation method and chromogenic agar medium].

    PubMed

    Hara-Kudo, Y; Sugiyama, K; Nishina, T; Saitoh, A; Nakagawa, H; Ichihara, T; Konuma, H; Hasegawa, J; Kumagai, S

    2001-11-01

    We attempted to isolate TDH-producing Vibrio parahaemolyticus O3:K6 from shellfish. Asari samples were incubated with TSB supplemented with 2% (w/v) NaCl for 6 h, and then the 6-h cultures were incubated with salt polymyxin broth for 18 h. After the two-step enrichment, a 1 ml portion of the culture was treated with magnetic beads coated with K6 antibody for immunoconcentration of V. parahaemolyticus O3:K6. The immunoconcentrated and untreated cultures were plated onto a chromogenic agar and TCBS agar media for isolation of V. parahaemolyticus. TDH-producing V. parahaemolyticus O3:K6 was isolated from 3 out of 66 lots (4.5%) of naturally contaminated Asari. Six of 4,265 colonies suspected as V. parahaemolyticus (0.14%) were TDH-producing V. parahaemolyticus O3:K6.

  7. Cultivation of Spirulina maxima in medium supplemented with sugarcane vinasse.

    PubMed

    dos Santos, Raquel Rezende; Araújo, Ofélia de Queiroz Fernandes; de Medeiros, José Luiz; Chaloub, Ricardo Moreira

    2016-03-01

    The feasibility of sugarcane vinasse as supplement in growth medium of Spirulina maxima was investigated. The cell was cultivated under autotrophic (no vinasse, 70 μmol photons m(-2) s(-1)), heterotrophic (no light, culture medium supplemented with vinasse at 0.1% v/v and 1.0% v/v) and mixotrophic conditions (70 μmol photons m(-2) s(-1), vinasse at 0.1% v/v and 1.0% v/v). These preliminary results suggested a cyclic two-stage cultivation - CTSC, with autotrophic condition during light phase of the photoperiod (12 h, 70-200 μmol photons m(-2) s(-1)) and heterotrophic condition during dark phase (12h, 3.0% v/v vinasse). The adopted CTSC strategy consisted in three cycles with 75% withdrawal of suspension and reposition of medium containing 3.0% v/v vinasse, separated by autotrophic rest periods of few days between cycles. Results show an increase of biomass concentration between 0.495 g L(-1) and 0.609 g L(-1) at the 7th day of each cycle and high protein content (between 74.3% and 77.3% w/w). PMID:26773377

  8. Interplanetary medium data book, supplement 4, 1985-1988

    NASA Technical Reports Server (NTRS)

    King, Joseph H.

    1989-01-01

    An extension is presented of the series of Interplanetary Medium Data Books and supplements which have been issued by the National Space Science Data Center since 1977. This volume contains solar wind magnetic field (IMF) and plasma data from the IMP 8 spacecraft for 1985 to 1988, and 1985 IMF data from the Czechoslovakian Soviet Prognoz 10 spacecraft. The normalization of the MIT plasma density and temperature, which has been discussed at length in previous volumes, is implemented as before, using the same normalization constants for 1985 to 1988 data as for the earlier data.

  9. Interplanetary medium data book, supplement 5, 1988-1993

    NASA Technical Reports Server (NTRS)

    King, Joseph H.; Papitashvili, Natalia E.

    1994-01-01

    This publication represents an extension of the series of Interplanetary Medium Data Books and supplements that have been issued by the National Space Science Data Center since 1977. This volume contains solar wind magnetic field and plasma data from the IMP 8 spacecraft for 1988 through the end of 1993. The normalization of the MIT plasma density and temperature, which has been discussed at length in previous volumes, is implemented as before, using the same normalization constants for 1988-1993 data as for the earlier data. Owing to a combination of non-continuity of IMP 8 telemetry acquisition and IMP's being out of the solar wind for about 40 percent of its orbit, the annual solar wind coverage for 1988-1993 is 40 plus or minus 5 percent. The plots and listings of this supplement are in essentially the same format as in previous supplements. Days for which neither IMF nor plasma data were available for any hours are omitted from the listings.

  10. Chromogenic agar medium for detection and isolation of Escherichia coli serogroups O26, O45, O103, O111, O121, and O145 from fresh beef and cattle feces.

    PubMed

    Kalchayanand, Norasak; Arthur, Terrance M; Bosilevac, Joseph M; Wells, James E; Wheeler, Tommy L

    2013-02-01

    Non-O157 Shiga toxin-producing Escherichia coli (STEC) strains are clinically important foodborne pathogens. Unlike E. coli O157:H7, these foodborne pathogens have no unique biochemical characteristics to readily distinguish them from other E. coli strains growing on plating media. In this study, a chromogenic agar medium was developed in order to differentiate among non-O157 STEC strains of serogroups O26, O45, O103, O111, O121, and O145 on a single agar medium. The ability of this chromogenic agar medium to select and distinguish among these pathogens is based on a combination of utilization of carbohydrates, b -galactosidase activity, and resistance to selective agents. The agar medium in combination with immunomagnetic separation was evaluated and successfully allowed for the detection and isolation of these six serogroups from artificially contaminated fresh beef. The agar medium in combination with immunomagnetic separation also allowed successful detection and isolation of naturally occurring non-O157 STEC strains present in cattle feces. Thirty-five strains of the top six non-O157 STEC serogroups were isolated from 1,897 fecal samples collected from 271 feedlot cattle. This chromogenic agar medium could help significantly in routine screening for the top six non-O157 STEC serogroups from beef cattle and other food.

  11. Use of the selective agar medium CREAD for monitoring the level of airborne spoilage moulds in cheese production.

    PubMed

    Kure, Cathrine Finne; Borch, Elisabeth; Karlsson, Ingela; Homleid, Jens Petter; Langsrud, Solveig

    2008-02-29

    It was investigated if a selective medium for common cheese spoiling moulds (CREAD) could give more relevant information than a general mould medium in hygienic air-sampling in cheese factories. A total of 126 air-samples were taken in six Nordic cheese factories using the general mould medium DG18 and CREAD. The level and genera of air-borne mould was determined. Identification to species-level was performed for a selection of samples. In five cheese factories the mycobiota was dominated by Penicillium spp. and in one cheese factory by Cladosporium spp. The concentration of air-borne moulds varied between the cheese factories ranging from 1 to 270 cfu/m3 on DG18 with a median value of 17. The number of mould colonies was in general lower at CREAD. Identification indicated that CREAD supported growth of common spoilage moulds for cheese, such as Penicillium palitans and P. commune. The mycobiota on DG18 also consisted of moulds not commonly associated with spoilage of cheese, such as Cladosporium spp., P. brevicompactum and P. chrysogenum. Contamination of cheese with mould is periodically a problem in production of semi-hard cheese and the level of air-borne mould is therefore routinely monitored in cheese factories. A clear correlation between the total number of moulds in air and mould growth on products is not always found. The conclusion from the investigation is that it is recommended to use a selective medium for cheese spoilage moulds, such as CREAD in hygienic monitoring.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    PubMed

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

    2001-05-01

    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.

  14. Survival of Tribolium confusum (Coleoptera: Tenebrionidae) in basal-casein medium supplemented with sodium selenite

    SciTech Connect

    Hogan, G.R.; Cole, B.S. )

    1988-01-01

    The trace substance selenium is known to influence several systems exhibiting a high rate of cellular proliferation. Data are reported on survival patterns and times in various developmental stages of Tribolium confusum Duval reared in a defined medium supplemented with sodium selenite. Insects reared from eggs hatching in a selenium medium (Se medium) show a prolonged time in the larval period and marked larval mortality compared with those reared on unsupplemented medium. Adults emerging in an Se medium show reduced survival compared with adults transferred to such medium 1 wk after emergence. Larval survival patterns mimic those of the adult, whereby younger larvae that are transferred to Se medium appear to be more sensitive than those exposed to Se medium later in the larval stage. Transfer of Se medium-reared adults to unsupplemented medium as pupae has a beneficial effect on survival compared with adults that emerged in Se medium 1 wk before transfer.

  15. Chlorella vulgaris production enhancement with supplementation of synthetic medium in dairy manure wastewater.

    PubMed

    Shi, Jun; Pandey, Pramod K; Franz, Annaliese K; Deng, Huiping; Jeannotte, Richard

    2016-03-01

    To identify innovative ways for better utilizing flushed dairy manure wastewater, we have assessed the effect of dairy manure and supplementation with synthetic medium on the growth of Chlorella vulgaris. A series of experiments were carried out to study the impacts of pretreatment of dairy wastewater and the benefits of supplementing dairy manure wastewater with synthetic medium on C. vulgaris growth increment and the ultrastructure (chloroplast, starch, lipid, and cell wall) of C. vulgaris cells. Results showed that the biomass production of C. vulgaris in dairy wastewater can be enhanced by pretreatment and using supplementation with synthetic media. A recipe combining pretreated dairy wastewater (40 %) and synthetic medium (60 %) exhibited an improved growth of C. vulgaris. The effects of dairy wastewater on the ultrastructure of C. vulgaris cells were distinct compared to that of cells grown in synthetic medium. The C. vulgaris growth in both synthetic medium and manure wastewater without supplementing synthetic medium was lower than the growth in dairy manure supplemented with synthetic medium. We anticipate that the results of this study will help in deriving an enhanced method of coupling nutrient-rich dairy manure wastewater for biofuel production.

  16. Genes required for and effects of alginate overproduction induced by growth of Pseudomonas aeruginosa on Pseudomonas isolation agar supplemented with ammonium metavanadate.

    PubMed

    Damron, F Heath; Barbier, Mariette; McKenney, Elizabeth S; Schurr, Michael J; Goldberg, Joanna B

    2013-09-01

    Pseudomonas aeruginosa is an opportunistic pathogen that can adapt to changing environments and can secrete an exopolysaccharide known as alginate as a protection response, resulting in a colony morphology and phenotype referred to as mucoid. However, how P. aeruginosa senses its environment and activates alginate overproduction is not fully understood. Previously, we showed that Pseudomonas isolation agar supplemented with ammonium metavanadate (PIAAMV) induces P. aeruginosa to overproduce alginate. Vanadate is a phosphate mimic and causes protein misfolding by disruption of disulfide bonds. Here we used PIAAMV to characterize the pathways involved in inducible alginate production and tested the global effects of P. aeruginosa growth on PIAAMV by a mutant library screen, by transcriptomics, and in a murine acute virulence model. The PA14 nonredundant mutant library was screened on PIAAMV to identify new genes that are required for the inducible alginate stress response. A functionally diverse set of genes encoding products involved in cell envelope biogenesis, peptidoglycan remodeling, uptake of phosphate and iron, phenazine biosynthesis, and other processes were identified as positive regulators of the mucoid phenotype on PIAAMV. Transcriptome analysis of P. aeruginosa cultures growing in the presence of vanadate showed differential expression of genes involved in virulence, envelope biogenesis, and cell stress pathways. In this study, it was observed that growth on PIAAMV attenuates P. aeruginosa in a mouse pneumonia model. Induction of alginate overproduction occurs as a stress response to protect P. aeruginosa, but it may be possible to modulate and inhibit these pathways based on the new genes identified in this study.

  17. Some Experiments With Agar-Grown Seedlings

    ERIC Educational Resources Information Center

    Freeland, P. W.

    1973-01-01

    Two percent agar gel is reported as a better medium for germination and growth studies. Students can be encouraged to undertake many simple experiments and make precise observations by using this medium. (PS)

  18. Modulation of stratum corneum lipid composition and organization of human skin equivalents by specific medium supplements.

    PubMed

    Thakoersing, Varsha S; van Smeden, Jeroen; Boiten, Walter A; Gooris, Gert S; Mulder, Aat A; Vreeken, Rob J; El Ghalbzouri, Abdoelwaheb; Bouwstra, Joke A

    2015-09-01

    Our in-house human skin equivalents contain all stratum corneum (SC) barrier lipid classes, but have a reduced level of free fatty acids (FAs), of which a part is mono-unsaturated. These differences lead to an altered SC lipid organization and thereby a reduced barrier function compared to human skin. In this study, we aimed to improve the SC FA composition and, consequently, the SC lipid organization of the Leiden epidermal model (LEM) by specific medium supplements. The standard FA mixture (consisting of palmitic, linoleic and arachidonic acids) supplemented to the medium was modified, by replacing protonated palmitic acid with deuterated palmitic acid or by the addition of deuterated arachidic acid to the mixture, to determine whether FAs are taken up from the medium and are incorporated into SC of LEM. Furthermore, supplementation of the total FA mixture or that of palmitic acid alone was increased four times to examine whether this improves the SC FA composition and lipid organization of LEM. The results demonstrate that the deuterated FAs are taken up into LEMs and are subsequently elongated and incorporated in their SC. However, a fourfold increase in palmitic acid supplementation does not change the SC FA composition or lipid organization of LEM. Increasing the concentration of the total FA mixture in the medium resulted in a decreased level of very long chain FAs and an increased level of mono-unsaturated FAs, which lead to deteriorated SC lipid properties. These results indicate that SC lipid properties can be modulated by specific medium supplements.

  19. Modified Hodge test using Mueller-Hinton agar supplemented with cloxacillin improves screening for carbapenemase-producing clinical isolates of Enterobacteriaceae.

    PubMed

    Takayama, Yoko; Adachi, Yuzuru; Nihonyanagi, Shin; Okamoto, Ryoichi

    2015-07-01

    Increasing numbers of clinical isolates of Enterobacteriaceae that produce carbapenemase are now being detected, with the most common carbapenemase found among Enterobacteriaceae in Japan being IMP-1-type metallo-β-lactamase. Clinical isolates of Enterobacteriaceae harbouring carbapenemases may be resistant to carbapenem antimicrobial agents, despite apparent in vitro susceptibility when tested according to Clinical and Laboratory Standards Institute criteria. We evaluated the prevalence of carbapenemase producers among isolates of Enterobacteriaceae at our hospital and assessed the performance of the modified Hodge test (MHT) for correctly identifying the phenotype. We studied 47 clinical isolates obtained between 2006 and 2010 for which the MIC of imipenem was 2 or 4 μg imipenem ml- 1. Antibacterial susceptibility testing was done for cephalosporins and carbapenems, the MHT was performed with meropenem and detection of the genes encoding IMP-1, VIM-2, KPC-2 and NDM-1-type metallo-β-lactamases was performed by PCR. Twelve isolates showed a positive result in the MHT with meropenem and were classified as carbapenemase producers. Of these 12 isolates, seven carried the gene for IMP-1 type, but not for VIM-2, KPC-2 or NDM-1 types. None of the carbapenemase genes tested were detected in the other five isolates. All five isolates were Enterobacter cloacae showing high resistance to ceftazidime and aztreonam. False-positive results were inhibited when Mueller-Hinton agar supplemented with 200 mg cloxacillin ml- 1 was used for the MHT. Five of 12 MHT-positive isolates were shown to have no carbapenemase genes and these isolates were high AmpC producers. Adding cloxacillin when performing the MHT prevented such false-positive results. The MHT with cloxacillin can overcome most problems related to detection of carbapenemases.

  20. [Evaluation of the impact of different lengths of pre-enrichment in a nutritive broth and prolonged incubation of MRSA-ID, a chromogenic agar medium, on its performances for identifying methicillin-resistant Staphylococcus aureus in screening samples].

    PubMed

    Grandin, S; Deschamps, C; Magdoud, F; Zihoune, N; Branger, C; Eveillard, M

    2009-05-01

    MRSA-carrier screening is recommended to prevent MRSA dissemination in hospitals. Rapid and specific detection of MRSA in the laboratory is a key element in enabling control measures. Our objective was to evaluate the impact of different lengths of pre-incubation in a nutritive broth and prolonged incubation of MRSA-ID, a chromogenic agar medium, on its performances for identifying MRSA in screening samples. According to our results, short-length pre-enrichments only provided a weak increase of sensitivity as compared to the absence of pre-enrichment. On the contrary, the sensitivity increase provided by an overnight pre-enrichment was significant. The prolongation of incubation in the chromogenic agar medium (48 hours instead of 24 hours) did not provide any significant increase of sensitivity but was associated with a strong and significant loss of specificity. Therefore, it seems relevant to reject prolonged incubation of selective agar media and to make a choice between the absence of pre-enrichment (faster results) and an overnight pre-enrichment (higher sensitivity), according to local epidemiology and local practices implemented for prevention.

  1. Evaluation of the chromogenic agar chromID C. difficile.

    PubMed

    Eckert, Catherine; Burghoffer, Béatrice; Lalande, Valérie; Barbut, Frederic

    2013-03-01

    Three selective media (chromID C. difficile agar, taurocholate cycloserine cefoxitin agar [TCCA; homemade], and CLO medium) were compared from 406 stool samples of patients suspected of having Clostridium difficile infection. The sensitivities of chromID C. difficile agar at 24 h and 48 h, CLO medium, and TCCA were 74.1%, 87%, 85.2%, and 70.4%, respectively.

  2. Dietary Medium Chain Fatty Acid Supplementation Leads to Reduced VLDL Lipolysis and Uptake Rates in Comparison to Linoleic Acid Supplementation

    PubMed Central

    van Schalkwijk, Daniël B.; Pasman, Wilrike J.; Hendriks, Henk F. J.; Verheij, Elwin R.; Rubingh, Carina M.; van Bochove, Kees; Vaes, Wouter H. J.; Adiels, Martin; Freidig, Andreas P.; de Graaf, Albert A.

    2014-01-01

    Dietary medium chain fatty acids (MCFA) and linoleic acid follow different metabolic routes, and linoleic acid activates PPAR receptors. Both these mechanisms may modify lipoprotein and fatty acid metabolism after dietary intervention. Our objective was to investigate how dietary MCFA and linoleic acid supplementation and body fat distribution affect the fasting lipoprotein subclass profile, lipoprotein kinetics, and postprandial fatty acid kinetics. In a randomized double blind cross-over trial, 12 male subjects (age 51±7 years; BMI 28.5±0.8 kg/m2), were divided into 2 groups according to waist-hip ratio. They were supplemented with 60 grams/day MCFA (mainly C8:0, C10:0) or linoleic acid for three weeks, with a wash-out period of six weeks in between. Lipoprotein subclasses were measured using HPLC. Lipoprotein and fatty acid metabolism were studied using a combination of several stable isotope tracers. Lipoprotein and tracer data were analyzed using computational modeling. Lipoprotein subclass concentrations in the VLDL and LDL range were significantly higher after MCFA than after linoleic acid intervention. In addition, LDL subclass concentrations were higher in lower body obese individuals. Differences in VLDL metabolism were found to occur in lipoprotein lipolysis and uptake, not production; MCFAs were elongated intensively, in contrast to linoleic acid. Dietary MCFA supplementation led to a less favorable lipoprotein profile than linoleic acid supplementation. These differences were not due to elevated VLDL production, but rather to lower lipolysis and uptake rates. PMID:25049048

  3. Evaluation of peptone glucose fluconazole agar as a selective medium for rapid and enhanced isolation of Aspergillus fumigatus from the respiratory tract of bronchopulmonary aspergillosis patients colonized by Candida albicans.

    PubMed

    Randhawa, H S; Chowdhary, Anuradha; Preeti Sinha, K; Kowshik, T; Vijayan, V K

    2006-06-01

    We have reported earlier that Aspergillus fumigatus is inhibited in vitro by Candida albicans which also interferes in its isolation from sputum experimentally seeded with predetermined graded inocula of the two fungi. It was further shown that this interference was neutralized by employing peptone glucose agar with incorporation of fluconazole which is more inhibitory to C. albicans than to A. fumigatus. This communication embodies the results of evaluation of peptone glucose fluconazole agar (PGFA) as a selective culture medium for rapid and enhanced isolation of A. fumigatus from sputum of patients clinically suspected of aspergillosis with C. albicans colonization in the respiratory tract. Of the 23 sputum specimens and one broncho-alveolar lavage collected from 15 suspected aspergillosis patients, A. fumigatus was isolated from all (100%) on PGFA as against only 19 specimens (79%) that proved to be positive on the control PGA medium (P<0.05). The greater efficacy of PGFA than that of PGA was further evident from the 2-fold higher A. fumigatus mean colony count (8.2+/-1.87) on the former medium than on the latter (3.7+/-1.00), and this difference was found to be statistically significant (P<0.05). Besides, A. fumigatus colonies were macroscopically recognizable within 2-3 days on PGFA at 28 degrees C in strong contrast to 5-7 days required on PGA. Based upon these observations, PGFA is recommended for wider application as a selective medium for rapid and enhanced recovery of A. fumigatus from sputum of patients clinically suspected of aspergillosis with C. albicans colonization in their respiratory tract.

  4. Enhancing Aerobic Growth of Campylobacter in Media Supplemented with Organic Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of agar and sodium bicarbonate (NaHCO3) concentration on aerobic growth of Campylobacter in was determined. A fumarate-pyruvate medium was supplemented with 0.0 to 0.2% agar and inoculated with Campylobacter coli, Campylobacter fetus, or Campylobacter jejuni. Portions of the inoculated me...

  5. Crystal formation in furunculosis agar

    USGS Publications Warehouse

    Bullock, G.L.; Ross, A.J.

    1964-01-01

    SINCE ITS INTRODUCTION SOME MONTHS AGO, FURUNCULOSIS AGAR has been employed in the diagnosis of suspect furunculosis and also as a general purpose medium. During our work with this medium we have noticed discrete "colonies," of crystalline material, which very closely resemble microbial colonies. These crystal colonies are compact and appear on both the surface and subsurface; they occur in inoculated slants and plates incubated for long periods (2 to 3 weeks), as well as in uninoculated stored medium. As the crystal colonies could be confusing to workers using this medium, we decided to attempt to identify them and also to determine whether storage conditions and different lots of medium affect crystal formation.

  6. 21 CFR 582.7115 - Agar-agar.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Agar-agar. 582.7115 Section 582.7115 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7115 Agar-agar. (a) Product. Agar-agar. (b) Conditions of use. This substance is generally recognized as safe when used...

  7. 21 CFR 582.7115 - Agar-agar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Agar-agar. 582.7115 Section 582.7115 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7115 Agar-agar. (a) Product. Agar-agar. (b) Conditions of use. This substance is generally recognized as safe when used...

  8. Effects of select medium supplements on in vitro development of Cryptosporidium parvum in HCT-8 cells.

    PubMed

    Upton, S J; Tilley, M; Brillhart, D B

    1995-02-01

    Surface-sterilized oocysts of Cryptosporidium parvum were applied to subconfluent monolayers of human adenocarcinoma (HCT-8) cells grown on coverslips in six-well cluster plates. Parasite-infected cultures were then incubated in RPMI 1640 with 10% fetal bovine serum, 15 mM HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) buffer, and antibiotics at 37 degrees C in a 5% CO2-95% air incubator for 2 h to allow sporozoites to excyst and enter cells. After cultures were washed free of debris, fresh cell culture media containing select supplements were added and cultures were reincubated. Parasite growth was assessed 66 h later by counting the number of parasite developmental stages in 25 random x 100 oil fields by Nomarski interference-contrast microscopy. Four vitamin supplements, calcium pantothenate, L-ascorbic acid, folic acid, and 4-(para)-aminobenzoic acid, each resulted in a significant increase in parasite numbers in vitro. The addition of insulin and the sugars glucose, galactose, and maltose also had a positive effect on parasite growth, although the effect was less pronounced than with any of the vitamins. Using the above information, we developed a supplemental medium formulation consisting of RPMI 1640 with 10% fetal bovine serum, 15 mM HEPES, 50 mM glucose, and 35 micrograms of ascorbic acid, 1.0 micrograms of folic acid, 4.0 micrograms of 4-aminobenzoic acid, 2.0 micrograms of calcium pantothenate, 0.1 U of insulin, 100 U of penicillin G, 100 micrograms of streptomycin, and 0.25 microgram of amphotericin B (Fungizone) per ml (pH 7.4). The growth of c. parvum in this medium was found to be enhanced approximately 10-fold compared with that in control medium without additional glucose, insulin, or vitamins. PMID:7714194

  9. 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

    PubMed Central

    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

  10. Supplementation of strontium to a chondrogenic medium promotes chondrogenic differentiation of human dedifferentiated fat cells.

    PubMed

    Okita, Naoya; Honda, Yoshitomo; Kishimoto, Naotaka; Liao, Wen; Azumi, Eiko; Hashimoto, Yoshiya; Matsumoto, Naoyuki

    2015-05-01

    Dedifferentiated fat cells (DFAT cells) isolated from adipose tissue have been demonstrated to differentiate into chondrogenic cells in vitro. Nevertheless, an efficient method to facilitate its chondrogenic differentiation is still unexplored, hampering the extensive application of these cells in cartilage regeneration therapies. Here we provide the evidence that supplementation of strontium ions (Sr) in a chondrogenic medium (CM) significantly promotes early chondrogenic differentiation of DFAT cells. Human DFAT cells and the mesenchymal stem cell line (RCB2153) were subjected to the CM supplemented with/without Sr. After 14 days, alcian blue staining intensity significantly increased in DFAT cells, but not in RCB2153, subjected to CM with Sr. mRNA expression analysis revealed that the CM with 1.5 mM Sr increased the expression of chondrogenic marker, collagen type 2 alpha 1, whereas there was no significant change in osteogenic markers, collagen type 1 alpha 1, runt-related transcription factor 2, and osteocalcin, and hypertrophic chondrogenic marker, collagen type 10 alpha 1. Inhibitors for extracellular signal-regulated kinase 1/2 (ERK1/2), Akt, and calcium-sensing receptor (CaSR) pathways significantly diminished the alcian blue staining intensity, providing the first evidence that these signal pathways are associated with chondrogenic differentiation of DFAT cells. CaSR and ERK1/2 pathways independently induced Sr-mediated early chondrogenic differentiation. These results suggest that Sr supplementation into the CM may provide a powerful platform for preparing chondrogenically differentiated DFAT cells for cartilage regeneration.

  11. New medium for the simultaneous detection of total coliforms and Escherichia coli in water.

    PubMed Central

    Brenner, K P; Rankin, C C; Roybal, Y R; Stelma, G N; Scarpino, P V; Dufour, A P

    1993-01-01

    A new membrane filter agar medium (MI agar) containing a chromogen, indoxyl-beta-D-glucuronide, and a fluorogen, 4-methylumbelliferyl-beta-D-galactopyranoside, was developed to simultaneously detect and enumerate Escherichia coli and total coliforms (TC) in water samples on the basis of their enzyme activities. TC produced beta-galactosidase, which cleaved 4-methylumbelliferyl-beta-D-galactopyranoside to form 4-methylumbelliferone, a compound that fluoresced under longwave UV light (366 nm), while E. coli produced beta-glucuronidase, which cleaved indoxyl-beta-D-glucuronide to form a blue color. The new medium TC and E. coli recoveries were compared with those of mEndo agar and two E. coli media, mTEC agar and nutrient agar supplemented with 4-methylumbelliferyl-beta-D-glucuronide, using natural water samples and spiked drinking water samples. On average, the new medium recovered 1.8 times as many TC as mEndo agar, with greatly reduced background counts (< or = 7%). These differences were statistically significant (significance level, 0.05). Although the overall analysis revealed no statistically significant difference between the E. coli recoveries on MI agar and mTEC agar, the new medium recovered more E. coli in 16 of 23 samples (69.6%). Both MI agar and mTEC agar recovered significantly more E. coli than nutrient agar supplemented with 4-methylumbelliferyl-beta-D-glucuronide. Specificities for E. coli, TC, and noncoliforms on MI agar were 95.7% (66 of 69 samples), 93.1% (161 of 173 samples), and 93.8% (61 of 65 samples), respectively. The E. coli false-positive and false-negative rates were both 4.3%. This selective and specific medium, which employs familiar membrane filter technology [corrected] to analyze several types of water samples, is less expensive than the liquid chromogen and fluorogen media and may be useful for compliance monitoring of drinking water. PMID:8285660

  12. Enhanced undecylprodigiosin production from Serratia marcescens SS-1 by medium formulation and amino-acid supplementation.

    PubMed

    Wei, Yu-Hong; Yu, Wan-Ju; Chen, Wei-Chuan

    2005-10-01

    Serratia marcescens Simon Swift-1 (SS-1) was used to produce a prodigiosin-like pigment, undecylprodigiosin (UP), known to have antitumor activities and potential as an anticancer drug. Modified media containing components of Luria-Bertani (LB) broth and selected amino acids were used to improve UP production from S. marcescens SS-1. Optimal culture conditions (e.g., temperature, pH, agitation rate) for UP production were also identified. It was found that S. marcescens SS-1 was able to produce 690 mg l-1 of UP when it was grown with 5 g l-1 yeast extract alone (YE medium) under the optimal culture conditions of 30 degrees C, 200 rpm, and pH 8. The UP production of 690 mg l-1 is nearly 23-fold of that obtained from original LB medium. Addition of amino acids containing pyrrole-like structures further enhanced UP production. Nearly 2 and 1.4 g l-1 of UP was produced when the SS-1 strain was cultivated with YE medium supplemented with proline and histidine (5 g l-1), respectively. Moreover, the addition of aspartic acid (5 g l-1) also resulted in a high UP production of 1.4 g l-1. Optimal dosages of the three amino acids were subsequently determined and the highest UP production (2.5 g l-1) was achieved with the addition of 10 g l-1 of proline. This suggests that the supplementation of amino acids related to the formation of a UP precursor (e.g., pyrrolylpyrromethene) could enhance UP production by the SS-1 strain.

  13. Mupirocin-mucin agar for selective enumeration of Bifidobacterium bifidum.

    PubMed

    Pechar, Radko; Rada, Vojtech; Parafati, Lucia; Musilova, Sarka; Bunesova, Vera; Vlkova, Eva; Killer, Jiri; Mrazek, Jakub; Kmet, Vladimir; Svejstil, Roman

    2014-11-17

    Bifidobacterium bifidum is a bacterial species exclusively found in the human intestinal tract. This species is becoming increasingly popular as a probiotic organism added to lyophilized products. In this study, porcine mucin was used as the sole carbon source for the selective enumeration of B. bifidum in probiotic food additives. Thirty-six bifidobacterial strains were cultivated in broth with mucin. Only 13 strains of B. bifidum utilized the mucin to produce acids. B. bifidum was selectively enumerated in eight probiotic food supplements using agar (MM agar) containing mupirocin (100 mg/L) and mucin (20 g/L) as the sole carbon source. MM agar was fully selective if the B. bifidum species was presented together with Bifidobacterium animalis subsp. lactis, Bifidobacterium breve, and Bifidobacterium longum subsp. longum species and with lactic acid bacteria (lactobacilli, streptococci). Isolated strains of B. bifidum were identified using biochemical, PCR, MALDI-TOF procedures and 16S rRNA gene sequencing. The novel selective medium was also suitable for the isolation of B. bifidum strains from human fecal samples.

  14. Mupirocin-mucin agar for selective enumeration of Bifidobacterium bifidum.

    PubMed

    Pechar, Radko; Rada, Vojtech; Parafati, Lucia; Musilova, Sarka; Bunesova, Vera; Vlkova, Eva; Killer, Jiri; Mrazek, Jakub; Kmet, Vladimir; Svejstil, Roman

    2014-11-17

    Bifidobacterium bifidum is a bacterial species exclusively found in the human intestinal tract. This species is becoming increasingly popular as a probiotic organism added to lyophilized products. In this study, porcine mucin was used as the sole carbon source for the selective enumeration of B. bifidum in probiotic food additives. Thirty-six bifidobacterial strains were cultivated in broth with mucin. Only 13 strains of B. bifidum utilized the mucin to produce acids. B. bifidum was selectively enumerated in eight probiotic food supplements using agar (MM agar) containing mupirocin (100 mg/L) and mucin (20 g/L) as the sole carbon source. MM agar was fully selective if the B. bifidum species was presented together with Bifidobacterium animalis subsp. lactis, Bifidobacterium breve, and Bifidobacterium longum subsp. longum species and with lactic acid bacteria (lactobacilli, streptococci). Isolated strains of B. bifidum were identified using biochemical, PCR, MALDI-TOF procedures and 16S rRNA gene sequencing. The novel selective medium was also suitable for the isolation of B. bifidum strains from human fecal samples. PMID:25217723

  15. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1115 Agar-agar. (a) Agar-agar (CAS Reg. No. PM 9002-18-0) is a...

  16. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1115 Agar-agar. (a) Agar-agar (CAS Reg. No. PM 9002-18-0) is a...

  17. Development of Culture Medium for the Isolation of Flavobacterium and Chryseobacterium from Rhizosphere Soil

    PubMed Central

    Nishioka, Tomoki; Elsharkawy, Mohsen Mohamed; Suga, Haruhisa; Kageyama, Koji; Hyakumachi, Mitsuro; Shimizu, Masafumi

    2016-01-01

    An effective medium designated phosphate separately autoclaved Reasoner’s 2A supplemented with cycloheximide and tobramycin (PSR2A-C/T) has been developed for the isolation of Flavobacterium and Chryseobacterium strains from the plant rhizosphere. It consists of Reasoner’s 2A agar (R2A) prepared by autoclaving phosphate and agar separately and supplementing with 50 mg L−1 cycloheximide and 1 mg L−1 tobramycin. A comparison was made among the following nine media: PSR2A-C/T, PSR2A-C/T supplemented with NaCl, R2A agar, R2A agar supplemented with cycloheximide and tobramycin, 1/4-strength tryptic soy agar (TSA), 1/10-strength TSA, soil-extract agar, Schaedler anaerobe agar (SAA), and SAA supplemented with gramicidin, for the recovery of Flavobacterium and Chryseobacterium strains from the Welsh onion rhizosphere. Flavobacterium strains were only isolated on PSR2A-C/T, and the recovery rate of Chryseobacterium strains was higher from PSR2A-C/T than from the eight other media. In order to confirm the effectiveness of PSR2A-C/T, bacteria were isolated from onion rhizosphere soil with this medium. Flavobacterium and Chryseobacterium strains were successfully isolated from this sample at a similar rate to that from the Welsh onion rhizosphere. PMID:27098502

  18. Development of Culture Medium for the Isolation of Flavobacterium and Chryseobacterium from Rhizosphere Soil.

    PubMed

    Nishioka, Tomoki; Elsharkawy, Mohsen Mohamed; Suga, Haruhisa; Kageyama, Koji; Hyakumachi, Mitsuro; Shimizu, Masafumi

    2016-06-25

    An effective medium designated phosphate separately autoclaved Reasoner's 2A supplemented with cycloheximide and tobramycin (PSR2A-C/T) has been developed for the isolation of Flavobacterium and Chryseobacterium strains from the plant rhizosphere. It consists of Reasoner's 2A agar (R2A) prepared by autoclaving phosphate and agar separately and supplementing with 50 mg L(-1) cycloheximide and 1 mg L(-1) tobramycin. A comparison was made among the following nine media: PSR2A-C/T, PSR2A-C/T supplemented with NaCl, R2A agar, R2A agar supplemented with cycloheximide and tobramycin, 1/4-strength tryptic soy agar (TSA), 1/10-strength TSA, soil-extract agar, Schaedler anaerobe agar (SAA), and SAA supplemented with gramicidin, for the recovery of Flavobacterium and Chryseobacterium strains from the Welsh onion rhizosphere. Flavobacterium strains were only isolated on PSR2A-C/T, and the recovery rate of Chryseobacterium strains was higher from PSR2A-C/T than from the eight other media. In order to confirm the effectiveness of PSR2A-C/T, bacteria were isolated from onion rhizosphere soil with this medium. Flavobacterium and Chryseobacterium strains were successfully isolated from this sample at a similar rate to that from the Welsh onion rhizosphere. PMID:27098502

  19. A critical synopsis: Continuous growth of proximal tubular kidney epithelial cells in hormone-supplemented serum-free medium

    NASA Technical Reports Server (NTRS)

    Chuman, L. M.; FINE; COHEN; Saier, M. H.

    1985-01-01

    The kidney forms urine and reabsorbs electrolytes and water. Kidney cell lines and hormone supplemented serum free medium were used for growth. The hormones were insulin, transferrin, vasopressin, cholesterol, prostaglandins, hydrocortisone, and triidothyronine. Epithelial cell lines are polar and form hemicysts. The Madin-Darby canine kidney(MDCK) cell line used is distal tubulelike. LLC-PK sub 1 cells are derived from pig kidneys and have the properties of different kidney segments. The LLC-PK sub 1 cells with proximal tubule properties were maintained in hormone-supplemented serum free medium. Seven factors (the aforementioned homrones and selenium) were needed for growth. Hormone-defined medium supported LLC-PK sub 1 cell growth, allowed transport (as seen by hemicyst formation), and influenced cell morphology. Vasopressin (used for growth and morphology) could be partially replaced by isobutylmethylxanthine or dibutyryl cAMP. The defined medium was used to isolate rabbit proximal tubule kidney epithelial cells free of fibroblasts.

  20. Comparison of recovery of airborne microorganisms in a dairy cattle facility using selective agar and thin agar layer resuscitation media.

    PubMed

    Crozier-Dodson, Beth Ann; Fung, Daniel Y C

    2002-09-01

    Thin agar layer (TAL) medium was developed at Kansas State University to improve the resuscitation of injured cells and has been shown to result in higher recovery than is obtained with selective media alone for cold-, heat-, salt-, and acid-injured cells. The experiment presented here was designed to determine the effectiveness of the TAL method for the recovery of possibly injured organisms from air. Eleven agar media were used for the experiment: tryptic soy agar (TSA), MacConkey sorbitol agar (MSA), TAL-MSA, Baird-Parker (BP) agar, TAL-BP agar, modified Oxford (MOX) agar, TAL-MOX agar, xylose lysine sodium desoxycholate (XLD) agar, TAL-XLD agar, Yersinia-selective (CIN) agar, and TAL-CIN agar. The TAL plates were prepared by pipetting 6 ml of selective agar into a BBL Rodac plate (65 by 15 mm). Selective agar was allowed to solidify, and then each plate was overlaid with 6 ml of TSA. Selective agar plates were prepared by pipetting 12 ml of agar into BBL Rodac plates and allowing the agar to solidify. Samples were taken at an indoor cattle facility at five separate locations with a BioScience SAS air-sampling instrument. For each plate, 60 liters of air was sampled. Three replications of the experiment were performed. The TAL method resulted in higher counts of microorganisms on all media tested. In addition, 175 isolates were selected randomly and identified in order to test the selectivity of TAL and the selective media for target organisms. The data obtained in this study show that the TAL resuscitation method is effective and necessary for the recovery of airborne organisms that may be injured.

  1. Human dental pulp stem cells cultured in serum-free supplemented medium

    PubMed Central

    Bonnamain, Virginie; Thinard, Reynald; Sergent-Tanguy, Solène; Huet, Pascal; Bienvenu, Géraldine; Naveilhan, Philippe; Farges, Jean-Christophe; Alliot-Licht, Brigitte

    2013-01-01

    Growing evidence show that human dental pulp stem cells (DPSCs) could provide a source of adult stem cells for the treatment of neurodegenerative pathologies. In this study, DPSCs were expanded and cultured with a protocol generally used for the culture of neural stem/progenitor cells. Methodology: DPSC cultures were established from third molars. The pulp tissue was enzymatically digested and cultured in serum-supplemented basal medium for 12 h. Adherent (ADH) and non-adherent (non-ADH) cell populations were separated according to their differential adhesion to plastic and then cultured in serum-free defined N2 medium with epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). Both ADH and non-ADH populations were analyzed by FACS and/or PCR. Results: FACS analysis of ADH-DPSCs revealed the expression of the mesenchymal cell marker CD90, the neuronal marker CD56, the transferrin receptor CD71, and the chemokine receptor CXCR3, whereas hematopoietic stem cells markers CD45, CD133, and CD34 were not expressed. ADH-DPSCs expressed transcripts coding for the Nestin gene, whereas expression levels of genes coding for the neuronal markers β-III tubulin and NF-M, and the oligodendrocyte marker PLP-1 were donor dependent. ADH-DPSCs did not express the transcripts for GFAP, an astrocyte marker. Cells of the non-ADH population that grew as spheroids expressed Nestin, β-III tubulin, NF-M and PLP-1 transcripts. DPSCs that migrated out of the spheroids exhibited an odontoblast-like morphology and expressed a higher level of DSPP and osteocalcin transcripts than ADH-DPSCs. Conclusion: Collectively, these data indicate that human DPSCs can be expanded and cultured in serum-free supplemented medium with EGF and bFGF. ADH-DPSCs and non-ADH populations contained neuronal and/or oligodendrocyte progenitors at different stages of commitment and, interestingly, cells from spheroid structures seem to be more engaged into the odontoblastic lineage than the ADH

  2. Development of a single bovine embryo improved by co-culture with trophoblastic vesicles in vitamin-supplemented medium.

    PubMed

    Mori, Miyuki; Kasa, Shojiro; Hattori, Masa-aki; Ueda, Shuji

    2012-01-01

    To improve the development of singly cultured bovine embryos, we developed a co-culture method with trophoblastic vesicles. The growth of trophoblastic cells was markedly increased in vitamin-supplemented medium 199 compared with medium 199. Upon co-culture of a single embryo with trophoblastic vesicles in vitamin-supplemented medium 199, embryo development to the blastocyst stage was significantly higher than in embryos co-cultured with trophoblastic vesicles in RPMI 1640 or with cumulus cells in medium 199 (control). In the absence of the vitamin cocktail, co-culture with trophoblastic vesicles in medium 199 did not improve embryo development compared with that of the control. The vitamin cocktail was effective in embryo development when co-cultured with trophoblastic vesicles, but not with cumulus cells. Embryo development was not improved in the absence of co-cultured trophoblastic vesicles, even in the presence of vitamin cocktail. In conclusion, the co-culture system with trophoblastic vesicles in vitamin-supplemented medium 199 efficiently enhances the development of singly cultured embryos. PMID:22878867

  3. Human serum provided additional values in growth factors supplemented medium for human chondrocytes monolayer expansion and engineered cartilage construction.

    PubMed

    Chua, K H; Aminuddin, B S; Fuzina, N H; Ruszymah, B H I

    2004-05-01

    We have previously formulated an optimized human chondrocytes growth medium based on 2% fetal bovine serum supplementation. For clinical usage, the animal serum must be replaced by patient own serum. We investigated the effects of human serum concentration for human nasal septum chondrocytes monolayer culture and cartilage reconstruction. Human serum demonstrated a dose dependent manner in promoting chondrocytes growth and cartilage engineering.

  4. Honey Supplementation to Semen-Freezing Medium ImprovesHuman Sperm Parameters Post-Thawing

    PubMed Central

    Alsaadi, Rana A-R.

    2014-01-01

    Objective To evaluate the effect of honey supplemented to cryoprotectant medium on post-thaw sperm motility, concentration, morphology and agglutination. Materials and methods Thirty semen samples were collected from 30 infertile patients. After assessment of semen analysis, semen samples were divided into 3 aliquots (0.7ml for each) and mixed with 1 ml of cryopreservation solution (G1, control) alone, or enriched with 5% honey (G2) or with 10% honey (G3) for cryopreservation. Cryopreservation was done at -196°C in liquid nitrogen and thawing was performed after six months. Direct swim up technique was used for in vitro sperm preparation post-thawing. Sperm parameters were assessed and data were statistically analyzed pre- and post-thawing. Results Results appeared that the percentage of sperm motility for G1 and G2 groups were significantly reduced (P < 0.05) post-thawing when compared to pre-cryopreservation. However, there was no significant difference in the total motility (%) of the post-thaw sperm between the G1 and G2 groups. While there was significant increased (P < 0.05) in the percentage of normal sperm morphology for G1 and G3 groups post-thawing. Post-thawing normal sperm morphology (%) for G3 group was significantly increased (P < 0.05) as compared to G1 and G2 groups. In contrast non significant differences (P > 0.05) were observed between G1 and G2 groups. Significant reduction (P < 0.05) was seen in the sperm concentration for all groups post-thawing as compared to pre-cryopreservation groups. After thawing the results reveal significant reduction (P < 0.05) in the sperm agglutination (%) for G3 group as compared to G1 and G2 groups. Conclusion The results of this study indicated that the supplementation of honey (10%) to cryoprotectant solution results in enhancement of sperm quality post-thawing. PMID:24971130

  5. Subculture of proliferating adult rat hepatocytes in medium supplemented with nicotinamide and EGF.

    PubMed

    Mitaka, T; Kojima, T; Mizuguchi, T; Mochizuki, Y

    1996-09-01

    To establish parenchymal hepatocyte cell lines, we tried to subculture the primary hepatocytes isolated from adult rats. The hepatocytes were cultured in serum-free modified Dulbecco's modified Eagle's medium supplemented with 10 mM nicotinamide and 10 ng/ml epidermal growth factor. When 6 x 10(5) cells were plated on 35-mm dishes coated with rat tail collagen, the cells proliferated and reached confluence at Day 6 to Day 8. The first subculture was carried out at Day 8 using 0.005% collagenase and gentle pipettings. Most cells were recovered and plated on the new dishes coated with the collagen (first passage). The attached cells could proliferate and reached near confluence when the cells occupied more than two-thirds of the dish surface. About a week after the first subculture, the second one was conducted. Although the number of the recovered cells was smaller than at the first passage, the cells could attach and proliferate to a certain extent. Thereafter, they were maintained for more than 2 mo, but they never overgrew. Albumin secretion into the culture medium was confirmed in the subcultured cells. Ultrastructurally, these subcultured cells possessed hepatic characteristics such as peroxisomes with a crystalline nucleiod and bile-canaliculus structures. When 10% fetal bovine serum and ascorbic acid 2-phosphate were added to the cells of the second passage, they began to proliferate very slowly. These proliferating cells were mainly mononucleate and had a small cytoplasm. In addition, some of them could differentitate into typical mature hepatocytes by forming a three-dimensional structure interacting with nonparenchymal cells. In this experiment, we showed the successful subculturing of parenchymal hepatocytes isolated from adult rats and provided evidence that the subcultured cells still have the potential to proliferate and to differentiate.

  6. Improving agar electrospinnability with choline-based deep eutectic solvents.

    PubMed

    Sousa, Ana M M; Souza, Hiléia K S; Uknalis, Joseph; Liu, Shih-Chuan; Gonçalves, Maria P; Liu, LinShu

    2015-09-01

    Very recently our group has produced novel agar-based fibers by an electrospinning technique using water as solvent and polyvinyl alcohol (PVA) as co-blending polymer. Here, we tested the deep eutectic solvent (DES), (2-hydroxyethyl)trimethylammonium chloride/urea prepared at 1:2 molar ratio, as an alternative solvent medium for agar electrospinning. The electrospun materials were collected with an ethanol bath adapted to a previous electrospinning set-up. One weight percent agar-in-DES showed improved viscoelasticity and hence, spinnability, when compared to 1 wt% agar-in-water and pure agar nanofibers were successfully electrospun if working above the temperature of sol-gel transition (∼80 °C). By changing the solvent medium we decreased the PVA concentration (5 wt% starting solution) and successfully produced composite fibers with high agar contents (50/50 agar/PVA). Best composite fibers were formed with the 50/50 and 30/70 agar/PVA solutions. These fibers were mechanically resistant, showed tailorable surface roughness and diverse size distributions, with most of the diameters falling in the sub-micron range. Both nano and micro forms of agar fibers (used separately or combined) may have potential for the design of new and highly functional agar-based materials. PMID:26116384

  7. Supplemented base medium containing Amburana cearensis associated with FSH improves in vitro development of isolated goat preantral follicles.

    PubMed

    Gouveia, B B; Macedo, T J S; Santos, J M S; Barberino, R S; Menezes, V G; Müller, M C; Almeida, J R G S; Figueiredo, J R; Matos, M H T

    2016-09-15

    The effects of Amburana cearensis ethanolic extract, with or without addition of a mix of supplements associated or not with FSH, on in vitro morphology and development of caprine secondary follicles were evaluated. In experiment 1, isolated follicles (250 μm in diameter) were cultured for 12 days in alpha-modified minimal essential medium (α-MEM) alone (control) or in medium composed of different concentrations of A. cearensis extract (Amb 0.1; 0.2, or 0.4 mg/mL). In experiment 2, culture media were α-MEM or Amb 0.2 mg/mL (both without supplements), or these same media supplemented with BSA, insulin, transferrin, selenium, glutamine, hypoxanthine, and ascorbic acid (referred as α-MEM(+) and Amb 0.2(+), respectively), or these last groups also supplemented with sequential FSH (100 ng/mL from Day 0 to Day 6; 500 ng/mL from Day 6 to Day 12), constituting groups α-MEM(+) + FSH and Amb 0.2(+) + FSH. At the end of culture in experiment 1, control medium (α-MEM) and Amb 0.2 mg/mL had higher percentages (P < 0.05) of morphologically normal follicles and percentage of fully grown oocytes, i.e., oocyte greater than 110 μm, compared to the other A. cearensis extract concentrations. In experiment 2, all supplemented media had higher percentages (P < 0.05) of normal follicles and antrum formation than nonsupplemented media. In addition, follicles cultured in Amb 0.2(+) + FSH showed an average increase in diameter higher (P < 0.05) than the other treatments. Oocytes cultured in both treatments supplemented with FSH showed greater glutathione and active mitochondria levels than nonsupplemented media but similar to the other treatments. In conclusion, A. cearensis extract (0.2 mg/mL) added by supplements and FSH improves follicular growth. Therefore, it can be an alternative culture medium for goat preantral follicle development. PMID:27287468

  8. Evaluation of Group B Streptococcus Differential Agar for detection and isolation of Streptococcus agalactiae.

    PubMed

    Bou, G; Figueira, M; Canle, D; Cartelle, M; Eiros, J M; Villanueva, R

    2005-08-01

    In total, 320 vaginal or rectal swabs were cultured on Granada medium (GM) or Group B Streptococcus Differential Agar (GBSDA), and were also inoculated into LIM broth (Todd-Hewitt broth supplemented with selective antibiotics), for detection of group B Streptococcus (GBS). Overall, GBS isolates were detected on 53 of the 320 swabs; 47 of these isolates grew on both GM and GBSDA, five only on GBSDA, and one only following subculture from LIM broth. GBSDA appears to be a valid alternative to GM for the growth of GBS isolates from pregnant women.

  9. 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: a multicenter study.

    PubMed

    Hegstad, Kristin; Giske, Christian G; Haldorsen, Bjørg; Matuschek, Erika; Schønning, Kristian; Leegaard, Truls M; Kahlmeter, Gunnar; Sundsfjord, Arnfinn

    2014-05-01

    Different antimicrobial susceptibility testing methods to detect low-level vancomycin resistance in enterococci were evaluated in a Scandinavian multicenter study (n=28). A phenotypically and genotypically well-characterized diverse collection of Enterococcus faecalis (n=12) and Enterococcus 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<0.0001) or Merck Mueller-Hinton (MH) agar (P=0.027) for the disk diffusion assay performed significantly better than did laboratories using BBL MH II medium. Laboratories using Difco brain heart infusion (BHI) agar for the CLSI agar screen performed significantly better (P=0.017) than did those using Oxoid BHI agar. In conclusion, both the EUCAST disk diffusion and CLSI agar screening methods performed acceptably (sensitivity, 0.93; specificity, 0.94 to 0.98) in the detection of VanB-type vancomycin-resistant enterococci with low-level resistance. Importantly, use of the CLSI agar screen requires careful monitoring of the vancomycin concentration in the plates. Moreover, disk diffusion methodology requires that personnel be trained in interpreting zone edges.

  10. Syneresis in agar hydrogels.

    PubMed

    Boral, Shilpi; Saxena, Anita; Bohidar, H B

    2010-03-01

    Agar hydrogels exhibit syneresis which creates internal osmotic stress on the physical network. It was observed that such a stress gives rise to characteristic pulsating modes (breathing modes). Experiments carried over a period of 60-day revealed that the network deformations grew monotonously when the solvent released by syneresis was removed periodically from gel surface. However, when the solvent was not withdrawn, the gel exhibited very slowly relaxing breathing modes. The swelling-deswelling dynamics has been discussed in the generalized framework of a dissipative damped oscillator.

  11. The effect of supplementation of amino acids and taurine to modified KSOM culture medium on rat embryo development.

    PubMed

    Nakamura, Kazuomi; Morimoto, Kayoko; Shima, Kaoru; Yoshimura, Yuki; Kazuki, Yasuhiro; Suzuki, Osamu; Matsuda, Junichiro; Ohbayashi, Tetsuya

    2016-11-01

    The rat is widely used as a laboratory animal for research. In particular, genetically engineered rats are essential for production of animal models of several diseases. Although embryo manipulation techniques are needed to produce them, such technology for rat preimplantation embryos is not as advanced as it is for mouse embryos. One reason is that in vitro culture systems for preimplantation embryos are limited in rats. Therefore, we intended to develop a new culture system for rat preimplantation embryos focusing on supplementation of amino acids as nutrition to the culture media. First, we found that taurine, glycine, glutamate, and alanine were abundant in the oviductal fluid of Wistar rats. The profile of taurine and these three amino acids was unchanged during the estrous cycle and from Days 0 to 3 of pregnancy (Day 0; vaginal plug was confirmed). Second, we assessed the effect of phosphate and phenol red on the development of rat zygotes and confirmed that they caused two-cell block. Third, we examined the effect of changing the medium on zygote development because addition of amino acids into culture medium causes ammonium accumulation, which is detrimental to embryo development. Blastocyst formation was suppressed in cultures with no medium change (P = 0.004; decreased to approximately one-fourth of that with medium change). Fourth, we examined the effect of supplementation of these three amino acids and taurine to modified potassium simplex optimized medium (KSOM). The zygote development rates were increased by the three amino acids and taurine in a concentration-dependent manner at 48, 72, and 96 hours (P = 0.001, 0.005, and 0.009, respectively) in culture. Finally, we confirmed that blastocysts cultured in modified KSOM had the capacity to develop to full term after implantation. These results showed that not only the supply of nutrients but also removal of wastes and toxicants is important for culture of rat preimplantation embryos.

  12. Pre-culturing of nodal explants in thidiazuron supplemented liquid medium improves in vitro shoot multiplication of Cassia angustifolia.

    PubMed

    Siddique, I; Abdullwahab Bukhari, N; Perveen, K; Siddiqui, I; Anis, M

    2013-09-01

    An in vitro propagation system for Cassia angustifolia Vahl. has been developed. Due to the presence of sennosides, the demand of this plant has increased manyfold in global market. Multiple shoots were induced by culturing nodal explants excised from mature plants on a liquid Murashige and Skoog [8] medium supplemented with 5-100 μM of thidiazuron (TDZ) for different treatment duration (4, 8, 12 and 16 d). The optimal level of TDZ supplemented to the culture medium was 75 μM for 12 d induction period followed by subculturing in MS medium devoid of TDZ as it produced maximum regeneration frequency (87%), mean number of shoots (9.6 ± 0.33) and shoot length (4.4 ± 0.46 cm) per explant. A culture period longer than 12 d with TDZ resulted in the formation of fasciated or distorted shoots. Ex vitro rooting was achieved when the basal cut end of regenerated shoots was dipped in 200 μM indole-3-butyric acid (IBA) for half an hour followed by their transplantation in plastic pots filled with sterile soilrite where 85% plantlets grew well and all exhibited normal development. The present findings describe an efficient and rapid plant regeneration protocol that can further be used for genetic transformation studies. PMID:24013898

  13. Screening for Intermediately Vancomycin-Susceptible and Vancomycin-Heteroresistant Staphylococcus aureus by Use of Vancomycin-Supplemented Brain Heart Infusion Agar Biplates: Defining Growth Interpretation Criteria Based on Gold Standard Confirmation.

    PubMed

    Khatib, Riad; Riederer, Kathleen; Sharma, Mamta; Shemes, Stephen; Iyer, Sugantha P; Szpunar, Susan

    2015-11-01

    BHI agars supplemented with vancomycin 4 (BHI-V4) and 3 (BHI-V3) mg/liter have been proposed for screening vancomycin intermediately susceptible Staphylococcus aureus (VISA) and heteroresistant (hVISA) phenotypes, respectively, but growth interpretation criteria have not been established. We reviewed the growth results (CFU) during population analysis profile-area under the curve (PAP-AUC) of consecutive methicillin-resistant Staphylococcus aureus (MRSA) blood isolates, which were saved intermittently between 1996 and 2012. CFU counts on BHI-V4 and BHI-V3 plates were stratified according to PAP-AUC interpretive criteria: <0.90 (susceptible [S-MRSA]), 0.90 to 1.3 (hVISA), and >1.3 (VISA). CFU cutoffs that best predict VISA and hVISA were determined with the use of receiver operating characteristic (ROC) curves. Mu3, Mu50, and methicillin-susceptible S. aureus (MSSA) controls were included. We also prospectively evaluated manufacturer-made BHI-V3/BHI-V4 biplates for screening of 2010-2012 isolates. The PAP-AUC of 616 clinical samples was consistent with S-MRSA, hVISA, and VISA in 550 (89.3%), 48 (7.8%), and 18 (2.9%) instances, respectively. For VISA screening on BHI-V4, a cutoff of 2 CFU/droplet provided 100% sensitivity and 97.7% specificity. To distinguish VISA from hVISA, a cutoff of 16 CFU provided 83.3% sensitivity and 94.7% specificity; the specificity was lowered to 89.5% with a 12-CFU cutoff. For detecting hVISA/VISA on BHI-V3, a 2-CFU/droplet cutoff provided 98.5% sensitivity and 93.8% specificity. These results suggest that 2-CFU/droplet cutoffs on BHI-V4 and BHI-V3 best approximate VISA and hVISA gold standard confirmation, respectively, with minimal overlap in samples with borderline PAP-AUC. Simultaneous screening for VISA/hVISA on manufacturer-made BHI-V4/BHI-V3 biplates is easy to standardize and may reduce the requirement for PAP-AUC confirmation. PMID:26311860

  14. Screening for Intermediately Vancomycin-Susceptible and Vancomycin-Heteroresistant Staphylococcus aureus by Use of Vancomycin-Supplemented Brain Heart Infusion Agar Biplates: Defining Growth Interpretation Criteria Based on Gold Standard Confirmation.

    PubMed

    Khatib, Riad; Riederer, Kathleen; Sharma, Mamta; Shemes, Stephen; Iyer, Sugantha P; Szpunar, Susan

    2015-11-01

    BHI agars supplemented with vancomycin 4 (BHI-V4) and 3 (BHI-V3) mg/liter have been proposed for screening vancomycin intermediately susceptible Staphylococcus aureus (VISA) and heteroresistant (hVISA) phenotypes, respectively, but growth interpretation criteria have not been established. We reviewed the growth results (CFU) during population analysis profile-area under the curve (PAP-AUC) of consecutive methicillin-resistant Staphylococcus aureus (MRSA) blood isolates, which were saved intermittently between 1996 and 2012. CFU counts on BHI-V4 and BHI-V3 plates were stratified according to PAP-AUC interpretive criteria: <0.90 (susceptible [S-MRSA]), 0.90 to 1.3 (hVISA), and >1.3 (VISA). CFU cutoffs that best predict VISA and hVISA were determined with the use of receiver operating characteristic (ROC) curves. Mu3, Mu50, and methicillin-susceptible S. aureus (MSSA) controls were included. We also prospectively evaluated manufacturer-made BHI-V3/BHI-V4 biplates for screening of 2010-2012 isolates. The PAP-AUC of 616 clinical samples was consistent with S-MRSA, hVISA, and VISA in 550 (89.3%), 48 (7.8%), and 18 (2.9%) instances, respectively. For VISA screening on BHI-V4, a cutoff of 2 CFU/droplet provided 100% sensitivity and 97.7% specificity. To distinguish VISA from hVISA, a cutoff of 16 CFU provided 83.3% sensitivity and 94.7% specificity; the specificity was lowered to 89.5% with a 12-CFU cutoff. For detecting hVISA/VISA on BHI-V3, a 2-CFU/droplet cutoff provided 98.5% sensitivity and 93.8% specificity. These results suggest that 2-CFU/droplet cutoffs on BHI-V4 and BHI-V3 best approximate VISA and hVISA gold standard confirmation, respectively, with minimal overlap in samples with borderline PAP-AUC. Simultaneous screening for VISA/hVISA on manufacturer-made BHI-V4/BHI-V3 biplates is easy to standardize and may reduce the requirement for PAP-AUC confirmation.

  15. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  16. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  17. 21 CFR 184.1115 - Agar-agar.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Agar-agar. 184.1115 Section 184.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD... ingredient meets the specifications of the “Food Chemicals Codex,” 3d Ed. (1981), p. 11, which...

  18. Blood agar and Mycobacterium tuberculosis: the end of a dogma.

    PubMed

    Drancourt, M; Carrieri, P; Gévaudan, M-J; Raoult, D

    2003-04-01

    Incidental blood agar-based recovery of Mycobacterium tuberculosis led us to further investigate this routine medium for primary isolation and culture of M. tuberculosis. Fifteen respiratory tract and eight lymph node Ziehl-Neelsen-positive specimens were inoculated in parallel into tubes containing egg-based medium and 5% sheep blood agar. Colonies appeared sooner on this medium than on the egg-based medium, but this difference was not significant (P = 0.11, analysis of variance [ANOVA] test). Further experiments compared the growth of 38 respiratory and lymph node M. tuberculosis isolates when subcultured on the two media. After 6 days of incubation, 21 of 38 isolates had grown on blood agar, and the mean number of colonies was significantly greater on blood agar than on the egg-based medium (P < 0 0.001, ANOVA test). These results demonstrate that M. tuberculosis grows easily on blood agar within 1to 2 weeks, indicating that this basic medium is suitable for laboratory diagnosis of tuberculosis in addition to other media. Laboratories that routinely use prolonged incubations of blood plates, for example, for the recovery of Bartonella species, should consider the potential safety implications of encountering this highly infectious pathogen.

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

    PubMed

    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.

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

    PubMed

    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. PMID:27380096

  1. Supplementation of an Artificial Medium for the Parasitoid Exorista larvarum (Diptera: Tachnidae) With Hemolymph of Hermetia illucens (Diptera: Stratiomyidae) or Antheraea pernyi (Lepidoptera: Saturniidae).

    PubMed

    Dindo, Maria Luisa; Vandicke, Jonas; Marchetti, Elisa; Spranghers, Thomas; Bonte, Jochem; De Clercq, Patrick

    2016-04-01

    The effect of supplementing hemolymph of the black soldier fly, Hermetia illucens (L.), or the Chinese oak silkworm, Antheraea pernyi (Guérin-Méneville), to a basic insect-free artificial medium for the tachinid Exorista larvarum (L.) was investigated. The supplementation (20% w/w) was based on the assumption that insect additives may optimize the media for this parasitoid. Egg hatch, pupal and adult yields, and sex ratio did not differ among the enriched and basic media. Preimaginal development was faster on both hemolymph-enriched media than on the basic medium. Despite the shorter development on the medium supplemented with H. illucens hemolymph than on the basic medium, on the two media puparium weights were comparable. The female flies reared on the medium enriched with H. illucens hemolymph did not lay more eggs, but the latter yielded significantly more puparia compared with the control females. Conversely, the medium enriched with A. pernyi hemolymph yielded lower female puparium weights than the basic medium and produced only one ovipositing female out of the five obtained female adults. These results indicate that the in vitro development of E. larvarum improved when the basic artificial medium was enriched with H. illucens hemolymph, whereas the supplementation with A. pernyi hemolymph negatively affected the quality of the in vitro-reared females. PMID:26921223

  2. Supplementation of an Artificial Medium for the Parasitoid Exorista larvarum (Diptera: Tachnidae) With Hemolymph of Hermetia illucens (Diptera: Stratiomyidae) or Antheraea pernyi (Lepidoptera: Saturniidae).

    PubMed

    Dindo, Maria Luisa; Vandicke, Jonas; Marchetti, Elisa; Spranghers, Thomas; Bonte, Jochem; De Clercq, Patrick

    2016-04-01

    The effect of supplementing hemolymph of the black soldier fly, Hermetia illucens (L.), or the Chinese oak silkworm, Antheraea pernyi (Guérin-Méneville), to a basic insect-free artificial medium for the tachinid Exorista larvarum (L.) was investigated. The supplementation (20% w/w) was based on the assumption that insect additives may optimize the media for this parasitoid. Egg hatch, pupal and adult yields, and sex ratio did not differ among the enriched and basic media. Preimaginal development was faster on both hemolymph-enriched media than on the basic medium. Despite the shorter development on the medium supplemented with H. illucens hemolymph than on the basic medium, on the two media puparium weights were comparable. The female flies reared on the medium enriched with H. illucens hemolymph did not lay more eggs, but the latter yielded significantly more puparia compared with the control females. Conversely, the medium enriched with A. pernyi hemolymph yielded lower female puparium weights than the basic medium and produced only one ovipositing female out of the five obtained female adults. These results indicate that the in vitro development of E. larvarum improved when the basic artificial medium was enriched with H. illucens hemolymph, whereas the supplementation with A. pernyi hemolymph negatively affected the quality of the in vitro-reared females.

  3. Agar underlay method for recovery of sublethally heat-injured bacteria.

    PubMed

    Kang, D H; Siragusa, G R

    1999-12-01

    A method of recovering sublethally heat-injured bacteria was developed. The procedure (termed the agar underlay method) uses a nonselective agar underlaid with a selective medium. In a two-chambered petri dish, the Lutri plate (LP), a nonselective agar is inoculated with a population of sublethally heat-injured bacteria. After a 2-h repair incubation period, selective agar is added to the bottom chamber of the LP and incubated. By diffusing through the nonselective top agar, selective agents from the underlay medium impart selectivity to the system. By the agar underlay method, recovery rates of the heat-injured food-borne pathogens Escherichia coli O157:H7 and Salmonella typhimurium were not different (P > 0. 05) from recovery rates determined with nonselective media. Sublethally heat-injured cells (60 degrees C for 1.5 min in buffer or 80 degrees C for 30 s on meat surfaces) grew and produced a typical colony morphology and color reaction when the agar underlay procedure was used with the appropriate respective selective agars. Unlike agar overlay methods for injury repair, the agar underlay procedure allows the typical selective-medium colony morphology to develop and allows colonies to be more easily picked for further characterization. Higher recovery rates of heat-injured fecal enterococci from bovine fecal samples and total coliforms from animal waste lagoons were obtained by the agar underlay method with selective agars than by direct plating on the respective selective media. PMID:10583985

  4. Effect of Medium Supplements on Agrobacterium rhizogenes Mediated Hairy Root Induction from the Callus Tissues of Camellia sinensis var. sinensis.

    PubMed

    Rana, Mohammad M; Han, Zhuo-Xiao; Song, Da-Peng; Liu, Guo-Feng; Li, Da-Xiang; Wan, Xiao-Chun; Karthikeyan, Alagarsamy; Wei, Shu

    2016-07-15

    Tea (Camellia sinensis L.) is recalcitrant to Agrobacterium-mediated genetic transformation largely due to the bactericidal effects of tea polyphenols and phenolics oxidation induced by necrosis of explant tissue over the process of transformation. In this study, different antioxidants/adsorbents were added as supplements to the co-cultivation and post co-cultivation media to overcome these problems for the transformation improvement. Tea-cotyledon-derived calli were used as explants and Agrobacterium rhizognes strain ATCC 15834 was used as a mediator. Results showed that Agrobacterium growth, virulence (vir) gene expression and browning of explant tissue were greatly influenced by different supplements. Murashige and Skoog (MS) basal salts medium supplemented with 30 g·L(-1) sucrose, 0.1 g·L(-1) l-glutamine and 5 g·L(-1) polyvinylpolypyrrolidone (PVPP) as co-cultivation and post co-cultivation media could maintain these parameters better that ultimately led to significant improvement of hairy root generation efficiency compared to that in the control (MS + 30 g·L(-1) sucrose). Additionally, the reporter genes β-glucuronidase (gusA) and cyan fluorescent protein (cfp) were also stably expressed in the transgenic hairy roots. Our study would be helpful in establishing a feasible approach for tea biological studies and genetic improvement of tea varieties.

  5. Effect of Medium Supplements on Agrobacterium rhizogenes Mediated Hairy Root Induction from the Callus Tissues of Camellia sinensis var. sinensis.

    PubMed

    Rana, Mohammad M; Han, Zhuo-Xiao; Song, Da-Peng; Liu, Guo-Feng; Li, Da-Xiang; Wan, Xiao-Chun; Karthikeyan, Alagarsamy; Wei, Shu

    2016-01-01

    Tea (Camellia sinensis L.) is recalcitrant to Agrobacterium-mediated genetic transformation largely due to the bactericidal effects of tea polyphenols and phenolics oxidation induced by necrosis of explant tissue over the process of transformation. In this study, different antioxidants/adsorbents were added as supplements to the co-cultivation and post co-cultivation media to overcome these problems for the transformation improvement. Tea-cotyledon-derived calli were used as explants and Agrobacterium rhizognes strain ATCC 15834 was used as a mediator. Results showed that Agrobacterium growth, virulence (vir) gene expression and browning of explant tissue were greatly influenced by different supplements. Murashige and Skoog (MS) basal salts medium supplemented with 30 g·L(-1) sucrose, 0.1 g·L(-1) l-glutamine and 5 g·L(-1) polyvinylpolypyrrolidone (PVPP) as co-cultivation and post co-cultivation media could maintain these parameters better that ultimately led to significant improvement of hairy root generation efficiency compared to that in the control (MS + 30 g·L(-1) sucrose). Additionally, the reporter genes β-glucuronidase (gusA) and cyan fluorescent protein (cfp) were also stably expressed in the transgenic hairy roots. Our study would be helpful in establishing a feasible approach for tea biological studies and genetic improvement of tea varieties. PMID:27428960

  6. Effect of Medium Supplements on Agrobacterium rhizogenes Mediated Hairy Root Induction from the Callus Tissues of Camellia sinensis var. sinensis

    PubMed Central

    Rana, Mohammad M.; Han, Zhuo-Xiao; Song, Da-Peng; Liu, Guo-Feng; Li, Da-Xiang; Wan, Xiao-Chun; Karthikeyan, Alagarsamy; Wei, Shu

    2016-01-01

    Tea (Camellia sinensis L.) is recalcitrant to Agrobacterium-mediated genetic transformation largely due to the bactericidal effects of tea polyphenols and phenolics oxidation induced by necrosis of explant tissue over the process of transformation. In this study, different antioxidants/adsorbents were added as supplements to the co-cultivation and post co-cultivation media to overcome these problems for the transformation improvement. Tea-cotyledon-derived calli were used as explants and Agrobacterium rhizognes strain ATCC 15834 was used as a mediator. Results showed that Agrobacterium growth, virulence (vir) gene expression and browning of explant tissue were greatly influenced by different supplements. Murashige and Skoog (MS) basal salts medium supplemented with 30 g·L−1 sucrose, 0.1 g·L−1 l-glutamine and 5 g·L−1 polyvinylpolypyrrolidone (PVPP) as co-cultivation and post co-cultivation media could maintain these parameters better that ultimately led to significant improvement of hairy root generation efficiency compared to that in the control (MS + 30 g·L−1 sucrose). Additionally, the reporter genes β-glucuronidase (gusA) and cyan fluorescent protein (cfp) were also stably expressed in the transgenic hairy roots. Our study would be helpful in establishing a feasible approach for tea biological studies and genetic improvement of tea varieties. PMID:27428960

  7. Cognition and Synaptic-Plasticity Related Changes in Aged Rats Supplemented with 8- and 10-Carbon Medium Chain Triglycerides

    PubMed Central

    Wang, Dongmei; Mitchell, Ellen S.

    2016-01-01

    Brain glucose hypometabolism is a common feature of Alzheimer’s disease (AD). Previous studies have shown that cognition is improved by providing AD patients with an alternate energy source: ketones derived from either ketogenic diet or supplementation with medium chain triglycerides (MCT). Recently, data on the neuroprotective capacity of MCT-derived medium chain fatty acids (MCFA) suggest 8-carbon and 10-carbon MCFA may have cognition-enhancing properties which are not related to ketone production. We investigated the effect of 8 week treatment with MCT8, MCT10 or sunflower oil supplementation (5% by weight of chow diet) in 21 month old Wistar rats. Both MCT diets increased ketones plasma similarly compared to control diet, but MCT diets did not increase ketones in the brain. Treatment with MCT10, but not MCT8, significantly improved novel object recognition memory compared to control diet, while social recognition increased in both MCT groups. MCT8 and MCT10 diets decreased weight compared to control diet, where MCFA plasma levels were higher in MCT10 groups than in MCT8 groups. Both MCT diets increased IRS-1 (612) phosphorylation and decreased S6K phosphorylation (240/244) but only MCT10 increased Akt phosphorylation (473). MCT8 supplementation increased synaptophysin, but not PSD-95, in contrast MCT10 had no effect on either synaptic marker. Expression of Ube3a, which controls synaptic stability, was increased by both MCT diets. Cortex transcription via qPCR showed that immediate early genes related to synaptic plasticity (arc, plk3, junb, egr2, nr4a1) were downregulated by both MCT diets while MCT8 additionally down-regulated fosb and egr1 but upregulated grin1 and gba2. These results demonstrate that treatment of 8- and 10-carbon length MCTs in aged rats have slight differential effects on synaptic stability, protein synthesis and behavior that may be independent of brain ketone levels. PMID:27517611

  8. Cognition and Synaptic-Plasticity Related Changes in Aged Rats Supplemented with 8- and 10-Carbon Medium Chain Triglycerides.

    PubMed

    Wang, Dongmei; Mitchell, Ellen S

    2016-01-01

    Brain glucose hypometabolism is a common feature of Alzheimer's disease (AD). Previous studies have shown that cognition is improved by providing AD patients with an alternate energy source: ketones derived from either ketogenic diet or supplementation with medium chain triglycerides (MCT). Recently, data on the neuroprotective capacity of MCT-derived medium chain fatty acids (MCFA) suggest 8-carbon and 10-carbon MCFA may have cognition-enhancing properties which are not related to ketone production. We investigated the effect of 8 week treatment with MCT8, MCT10 or sunflower oil supplementation (5% by weight of chow diet) in 21 month old Wistar rats. Both MCT diets increased ketones plasma similarly compared to control diet, but MCT diets did not increase ketones in the brain. Treatment with MCT10, but not MCT8, significantly improved novel object recognition memory compared to control diet, while social recognition increased in both MCT groups. MCT8 and MCT10 diets decreased weight compared to control diet, where MCFA plasma levels were higher in MCT10 groups than in MCT8 groups. Both MCT diets increased IRS-1 (612) phosphorylation and decreased S6K phosphorylation (240/244) but only MCT10 increased Akt phosphorylation (473). MCT8 supplementation increased synaptophysin, but not PSD-95, in contrast MCT10 had no effect on either synaptic marker. Expression of Ube3a, which controls synaptic stability, was increased by both MCT diets. Cortex transcription via qPCR showed that immediate early genes related to synaptic plasticity (arc, plk3, junb, egr2, nr4a1) were downregulated by both MCT diets while MCT8 additionally down-regulated fosb and egr1 but upregulated grin1 and gba2. These results demonstrate that treatment of 8- and 10-carbon length MCTs in aged rats have slight differential effects on synaptic stability, protein synthesis and behavior that may be independent of brain ketone levels. PMID:27517611

  9. Rational design of medium supplementation strategy for improved influenza viruses production based on analyzing nutritional requirements of MDCK Cells.

    PubMed

    Huang, Ding; Xia-Hou, Kang; Liu, Xu-Ping; Zhao, Liang; Fan, Li; Ye, Zhaoyang; Tan, Wen-Song; Luo, Jian; Chen, Ze

    2014-12-12

    Influenza vaccine production using cell culture technology has become popular nowadays. However, to meet the ever increasing demand of influenza vaccine, it is prerequisite to improve the yield of influenza virus in cells. To achieve this, in the present study, the nutritional requirements of MDCK cells in the virus production process were analyzed and a nutrient-feeding strategy was developed accordingly. Based on the consumption rates and corresponding concentration optimization, glucose and fast metabolized amino acids were supplemented into the maintaining medium at the time of infection. Compared with the non-supplemented culture, the average cell specific death rate during 0-48 h post-infection was 0.013 h(-1), which was 40.91% lower in the nutrient-supplemented culture. Total virus titer, HA antigen protein concentration and cell-specific virus yield were (1.88±0.23)×10(3) HA units/50μL, 11.70±0.22 μg/mL and (10.06±1.16)×10(3) virions/cell, respectively, which were 84.04±22.50%, 31.46±2.87% and 86.64±25.81% higher than those in the control, respectively. These data showed that the appropriate supplementation of nutrients during virus production process could reduce cell death, and improve cell-specific virus yield and total influenza virus output. This study laid foundation for the development of cell culture technology for influenza vaccine production.

  10. [Clinical utility of Pourmedia GBS agar on screening for vaginal colonization of Group B Streptococcus].

    PubMed

    Kaneda, Mitsunori; Nagasaki, Hiromi; Tasaki, Megumi; Kamiyama, Kiyoshi

    2014-01-01

    Group B Streptococcus (GBS) are normal flora of the vagina and intestinal, but if the pregnant woman was infected with GBS in the vagina, miscarriage or premature would occur or the newborn would be developed to severe GBS infection. It is recommended that the inspection of GBS on all pregnant women by Japan Society of Obstetrics and Gynecology (JSOG) and Center for Disease Control and Prevention (CDC). We examined the comparison of detection rate between Pourmedia GBS agar (Eiken Chemical Co., Ltd.) and Nissui Separated Plate Sheep Blood Agar/BTB Lactose Agar medium (Nissui Pharmaceutical Co., Ltd.) on 112 sample. The positive rate of Pourmedia GBS agar was 21.4% (24/112 samples), Whereas Nissui Separated Plate Sheep Blood Agar/BTB Lactose Agar medium was 17.8% (20/112 samples). It was found that the detection rate was improved by using Pourmedia GBS agar on GBS screening test of vaginal swab.

  11. Growth of Desulfovibrio on the Surface of Agar Media

    PubMed Central

    Iverson, Warren P.

    1966-01-01

    Growth of Desulfovibrio desulfuricans (API strain) was found to take place in an atmosphere of hydrogen on the agar surface of complex media, including yeast extract (Difco), and Trypticase Soy Agar (BBL) without any added reducing agents. For growth on a 2% yeast extract-agar surface in the absence of hydrogen (nitrogen atmosphere), sodium lactate was required in the medium. Growth on the surface of Trypticase Soy Agar (TSA) under nitrogen took place readily in the absence of an added hydrogen donor. A medium (TSA plus salts) is described based upon the addition of sodium lactate (4 ml per liter), magnesium sulfate (2 g per liter), and ferrous ammonium sulfate (0.05%) to TSA, which appears suitable for the isolation and growth of Desulfovibrio on the surface of agar plates in an atmosphere of hydrogen. Sodium lactate does not appear to be essential in this medium for good growth and sulfate reduction in a hydrogen atmosphere, but is essential in a nitrogen atmosphere. Growth of Desulfovibrio (hydrogen atmosphere) on the agar surface of media commonly used for its cultivation as well as on an inorganic medium containing bicarbonate as a source of carbon is poor and erratic unless inoculated (Desulfovibrio) plates of TSA plus salts are incubated in the same container with plates of these media. This stimulatory effect of incubation with inoculated plates of TSA plus salts medium appears to be due to as yet unidentified volatile material produced by D. desulfuricans when growing on this medium. Another volatile material, or possibly the identical material, appears to act similarly to a hydrogen donor. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:5955798

  12. Performance characteristics of a diesel engine using low- and medium-energy gases as a fuel supplement (fumigation)

    NASA Technical Reports Server (NTRS)

    Monford, L. G.

    1976-01-01

    The use of low- and medium-energy gases derived from solid waste is investigated. Gases that simulate those gases that could be derived from refuse were injected into the air inlet of a 298-kilowatt (400 horsepower) diesel engine as a fuel supplement. This process is called fumigation. Three different gases with thermal-energy contents of 6.11 MJ/cu m (164 Btu/cu ft), 18.1 MJ/cu m (485 Btu/cu ft), and 18.8 MJ/cu m (505 Btu/cu ft, respectively, were used at rates ranging as high as 20 percent of the normal fuel oil energy at four different engine load points. The test results indicated approximately 100 percent gas energy utilization with no observable deleterious effect on the engine.

  13. Ex vivo expansion of bovine corneal endothelial cells in xeno-free medium supplemented with platelet releasate.

    PubMed

    Chou, Ming-Li; Burnouf, Thierry; Wang, Tsung-Jen

    2014-01-01

    Clinical-grade ex vivo expansion of corneal endothelial cells can increase the availability of corneal tissues for transplantation and treatment of corneal blindness. However, these cells have very limited proliferative capacity. Successful propagation has required so far to use very complex growth media supplemented with fetal bovine serum and other xenocomponents. We hypothesized that human platelet releasates rich in multiple growth factors, and in particular neurotrophins, could potentially be a useful supplement for ex vivo expansion of corneal endothelium cells due to their neural crest origin. Platelet releasates were prepared by calcium salt activation of apheresis platelet concentrates, subjected or not to complement inactivation by heat treatment at 56°C for 30 minutes. Platelet releasates were characterized for their content in proteins and were found to contain high amount of growth factors including platelet-derived growth factor-AB (30.56 to 39.08 ng/ml) and brain-derived neurotrophic factor (30.57 to 37.11 ng/ml) neurotrophins. We compared the growth and viability of corneal endothelium cells in DMEM-F12 medium supplemented with different combinations of components, including 2.5%∼10% of the platelet releasates. Corneal endothelium cells expanded in platelet releasates exhibited good adhesion and a typical hexagonal morphology. Their growth and viability were enhanced when using the complement-inactivated platelet releasate at a concentration of 10%. Immunostaining and Western blots showed that CECs maintained the expressions of four important membrane markers: Na-K ATPase α1, zona occludens-1, phospho-connexin 43 and N-cadherin. In conclusion, our study provides the first proof-of-concept that human platelet releasates can be used for ex vivo expansion of corneal endothelium cells. These findings open a new paradigm for ex vivo propagation protocols of corneal endothelium cells in compliance with good tissue culture practices and regulatory

  14. Importance of nutritional status in recovery from acute cholecystitis: benefit from enteral nutrition supplementation including medium chain triglycerides.

    PubMed

    Nomura, Yukinobu; Inui, Kazuo; Yoshino, Junji; Wakabayashi, Takao; Okushima, Kazumu; Kobayashi, Takashi; Miyoshi, Hironao; Nakamura, Yuta

    2007-09-01

    This study was undertaken to clarify the importance of nutritional status in patients with acute cholecystitis, and also evaluate whether they benefited from enteral nutrition supplementation, including medium-chain triglycerides (MCT), during the convalescent stage. Patients with acute cholecystitis admitted to our hospital between April 1994 and March 2002 were classified into a poor nutrition group (n=40; total serum protein<5.0 g/dl) or a fair nutrition group (n=71; >5.0 g/dl). Patients with poor nutrition were significantly more elderly than those with fair nutrition, and had significantly higher serum C-reactive protein (CRP) concentrations. The two groups did not differ significantly with respect to other laboratory data, gender distribution, or medical treatment. We supplemented ordinary meals with enteral nutrition including MCT in 16 patients during the convalescent stage (MCT group). We compared their length of hospital stay and days required to recovery to pre-admission functional status for activities of daily living (ADL) with the same intervals in 16 patients without supplementation (non-MCT group) selected to match for age, gender, and fair or poor nutritional status from among 111 patients. Hospitalizations were significantly longer in the poor nutrition group (43.0+/-2.2 days) than in the fair nutrition group (27.0+/-8.2 days). Significantly more days were required to recover ADL status in the poor nutrition group (12.0+/-7.2 days) than in the fair group (9.4+/-5.2 days). Hospitalizations were significantly shorter in the MCT group (20.1+/-15 days) than in the non-MCT group (35.4+/-12.8 days). Significantly fewer days were required to recover ADL status in the MCT group (10.9+/-7 days) than in the non-MCT group (13.1+/-6.8 days). Administration of enteral nutrition including MCT during convalescence from acute cholecystitis thus appears to promote functional recovery shorten hospital stay.

  15. A hidden pitfall in the preparation of agar media undermines microorganism cultivability.

    PubMed

    Tanaka, Tomohiro; Kawasaki, Kosei; Daimon, Serina; Kitagawa, Wataru; Yamamoto, Kyosuke; Tamaki, Hideyuki; Tanaka, Michiko; Nakatsu, Cindy H; Kamagata, Yoichi

    2014-12-01

    Microbiologists have been using agar growth medium for over 120 years. It revolutionized microbiology in the 1890s when microbiologists were seeking effective methods to isolate microorganisms, which led to the successful cultivation of microorganisms as single clones. But there has been a disparity between total cell counts and cultivable cell counts on plates, often referred to as the "great plate count anomaly," that has long been a phenomenon that still remains unsolved. Here, we report that a common practice microbiologists have employed to prepare agar medium has a hidden pitfall: when phosphate was autoclaved together with agar to prepare solid growth media (PT medium), total colony counts were remarkably lower than those grown on agar plates in which phosphate and agar were separately autoclaved and mixed right before solidification (PS medium). We used a pure culture of Gemmatimonas aurantiaca T-27(T) and three representative sources of environmental samples, soil, sediment, and water, as inocula and compared colony counts between PT and PS agar plates. There were higher numbers of CFU on PS medium than on PT medium using G. aurantiaca or any of the environmental samples. Chemical analysis of PT agar plates suggested that hydrogen peroxide was contributing to growth inhibition. Comparison of 454 pyrosequences of the environmental samples to the isolates revealed that taxa grown on PS medium were more reflective of the original community structure than those grown on PT medium. Moreover, more hitherto-uncultivated microbes grew on PS than on PT medium.

  16. A Hidden Pitfall in the Preparation of Agar Media Undermines Microorganism Cultivability

    PubMed Central

    Tanaka, Tomohiro; Kawasaki, Kosei; Daimon, Serina; Kitagawa, Wataru; Yamamoto, Kyosuke; Tamaki, Hideyuki; Tanaka, Michiko; Nakatsu, Cindy H.

    2014-01-01

    Microbiologists have been using agar growth medium for over 120 years. It revolutionized microbiology in the 1890s when microbiologists were seeking effective methods to isolate microorganisms, which led to the successful cultivation of microorganisms as single clones. But there has been a disparity between total cell counts and cultivable cell counts on plates, often referred to as the “great plate count anomaly,” that has long been a phenomenon that still remains unsolved. Here, we report that a common practice microbiologists have employed to prepare agar medium has a hidden pitfall: when phosphate was autoclaved together with agar to prepare solid growth media (PT medium), total colony counts were remarkably lower than those grown on agar plates in which phosphate and agar were separately autoclaved and mixed right before solidification (PS medium). We used a pure culture of Gemmatimonas aurantiaca T-27T and three representative sources of environmental samples, soil, sediment, and water, as inocula and compared colony counts between PT and PS agar plates. There were higher numbers of CFU on PS medium than on PT medium using G. aurantiaca or any of the environmental samples. Chemical analysis of PT agar plates suggested that hydrogen peroxide was contributing to growth inhibition. Comparison of 454 pyrosequences of the environmental samples to the isolates revealed that taxa grown on PS medium were more reflective of the original community structure than those grown on PT medium. Moreover, more hitherto-uncultivated microbes grew on PS than on PT medium. PMID:25281372

  17. Evaluation of eight agar media for the isolation of shiga toxin-Producing Escherichia coli.

    PubMed

    Gill, Alexander; Huszczynski, George; Gauthier, Martine; Blais, Burton

    2014-01-01

    The growth characteristics of 96 shiga toxin-producing Escherichia coli (STEC) strains representing 36 different O-types (including priority O types O26, O45, O103, O111, O121, O145 and O157) on commercial and in-house agar media were studied. The ability of the strains to grow on agar media with varying selective supplement formulations was evaluated using MacConkey Agar (MAC); Rainbow® Agar O157 (RBA); Rainbow® Agar O157 with manufacturer-recommended selective supplements (RBA-NT); Rainbow® Agar O157 with USDA-recommended selective supplements (RBA-USDA); CHROMagar STEC™ (CH STEC); Tryptone Bile agar containing cefixime and tellurite (TBA-CT); Tryptone Bile agar containing cefixime, tellurite, eosin and methylene blue (TBA-EM); and VTEC agar. All of the strains were able to grow on MAC, RBA and VTEC agar, whereas a number of strains (including some non-O157 priority O types) were unable to grow on the highly selective media CH STEC, RBA-NT, RBA-USDA, TBA-EM and TBA-CT. Only RBA-NT and CH STEC exhibited significant inhibition of background flora from ground beef enrichment. Significant inhibition of background flora from beef trim enrichment was observed with RBA-NT, RBA-USDA, CH STEC, TBA-EM and VTEC agar. With exception of E. coli O157, several different colony morphologies were observed on the differential plating media among strains of the same O type, indicating that this colony morphology is not a reliable means of identifying target STEC. These results suggest that an approach to maximize the recovery of target STEC from beef enrichment cultures is dual plating on lesser (RBA, MAC, VTEC agar) and more highly (RBA-NT, CH STEC) selective agars.

  18. Effect of select medium supplements on in vitro development of Cryptosporidium andersoni in HCT-8 cells.

    PubMed

    Wu, Liang; Chen, Sheng-xia; Jiang, Xu-gan; Shen, Yu-juan; Lu, Zhao-xi; Tu, Guo-hua; Fu, Xing-li; Cao, Jian-ping

    2009-10-01

    We evaluated the effect of fetal calf serum (FCS), glucose, ascorbic acid, calcium pantothenate, folic acid, and insulin on the growth of Cryptosporidium andersoni in human colon tumor (HCT-8) cells. After being incubated for 48 h, the proliferation of parasites was determined by real-time polymerase chain reaction (PCR) assay, and the development of C. andersoni was observed by transmission electron microscopy (TEM). Ten percent FCS was the best concentration for C. andersoni culture. Glucose, ascorbic acid, and insulin had a significant effect on the growth of C. andersoni when added into 10% FCS RPMI 1640. Calcium pantothenate had no significant effect and folic acid had the inhibited effect. We also observed the stages of trophozoite, macrogamont, microgamont, type I meront, type II meront, and sporozoite of C. andersoni in HCT-8 cells by TEM. Our results indicated that the best medium for C. andersoni was 10% FCS RPMI 1640 medium containing 50 mM glucose, 50 microg/ml ascorbic acid, and 0.3 U/ml insulin. Real-time PCR could provide a quick and precise technique to determine the proliferation of parasites. Cultivation of C. andersoni in HCT-8 cells will facilitate the study of interactions between parasites and host cells as well as provide a reliable system for evaluating anticryptosporidial compound efficacy. PMID:19641939

  19. Improvement of Karmali agar by addition of polymyxin B for the detection of Campylobacter jejuni and C. coli in whole-chicken carcass rinse.

    PubMed

    Chon, Jung-Whan; Kim, Hyunsook; Yim, Jin-Hyeok; Song, Kwang-Young; Moon, Jin-San; Kim, Young-Jo; Seo, Kun-Ho

    2013-05-01

    The Karmali agar was modified by supplementation with a high concentration of polymyxin B. The goal of the study was to evaluate the effect of a high concentration of polymyxin B on the ability and selectivity of the modified Karmali agar to isolate Campylobacter jejuni and Campylobacter coli from whole chicken carcass rinse. A total of 80 whole chickens were rinsed with 400 mL of buffer peptone water. The rinsed samples were incubated with 2× blood-free modified Bolton enrichment broth for 48 h, and then streaked onto unmodified Karmali agar and modified Karmali agar supplemented with 100000 IU/L polymixin B (P-Karmali agar). The suspected colonies were finally confirmed by colony PCR. The P-Karmali agar exhibited a significantly better (P < 0.05) isolation rate than the unmodified Karmali agar (P-Karmali agar, 73.8%; unmodified Karmali agar, 33.8%). Moreover, the selectivity of the P-Karmali agar was also better (P < 0.05) than that of the other selective agar when comparing the number of contaminated plates (P-Karmali agar, 68.8%; unmodified Karmali agar, 87.5%) and growth index of competing flora (P-Karmali agar, 1.4; unmodified Karmali agar, 2.7). The improved selective agar excluded competing flora resistant to antibiotic agents in unmodified Karmali agar, increasing isolation rate and selectivity for C. jejuni and C. coli.

  20. Glycerol supplementation of the growth medium enhances in situ detoxification of furfural by Clostridium beijerinckii during butanol fermentation.

    PubMed

    Ujor, Victor; Agu, Chidozie Victor; Gopalan, Venkat; Ezeji, Thaddeus Chukwuemeka

    2014-01-01

    Lignocellulose-derived microbial inhibitors such as furfural and 5-hydroxymethyl furfural adversely affect fermentation of lignocellulosic biomass hydrolysates to fuels and chemicals due to their toxicity on fermenting microbes. To harness the potential of lignocellulose as a cheap source of fermentable sugars, in situ detoxification of furfural and other lignocellulose-derived microbial inhibitors is essential. To enhance in situ detoxification and tolerance of furfural by Clostridium beijerinckii NCIMB 8052 during acetone-butanol-ethanol (ABE) fermentation, the effect of glycerol on NADH/NADPH generation and ABE production by furfural (4, 5, and 6 g/L)-challenged cultures was investigated in this study. In all instances, beneficial outcomes were observed. For example, the fermentation medium supplemented with glycerol and subjected to 5 g/L furfural elicited up to 1.8- and 3-fold increases, respectively, in NADH and NADPH levels in C. beijerinckii 8052 relative to the control culture. These critical changes are the likely underpinnings for the glycerol-mediated 2.3-fold increase in the rate of detoxification of 5 g/L furfural, substrate consumption, and ABE production compared to the unsupplemented medium. Collectively, these results demonstrate that increased intracellular NADH/NADPH in C. beijerinckii 8052 due to glycerol utilization engenders favorable effects on many aspects of cellular metabolism, including enhanced furfural reduction and increased ABE production.

  1. Abolition of Swarming of Proteus by p-Nitrophenyl Glycerin: Application to Blood Agar Media

    PubMed Central

    Williams, Fred D.

    1973-01-01

    Comparative plate counts were made of Staphylococcus aureus and Streptococcus pyogenes growing on blood agar supplemented with individual chemicals to abolish the swarming of Proteus. B-phenylethanol, sodium azide, and p-nitrophenyl glycerin (PNPG) were used as anti-swarm agents. Each anti-swarm agent effectively abolished swarming for 24 h, but azide failed to control swarming for longer periods of incubation. In addition, azide displayed growth inhibition towards the staphylococci and streptococci resulting in no hemolysis and reduced viable cell numbers with the streptococci. Phenylethanol showed reduced viable cell numbers with the streptococci and unreliable hemolytic reactions. At 0.1 to 0.3 mM, PNPG proved to be a superior anti-swarm agent in that it showed no growth inhibition and allowed normal hemolysis, but abolished swarming for extended periods of time. When laboratory strains of Streptococcus pneumoniae, Klebsiella pneumoniae, Pseudomonas aeruginosa. Listeria monocytogenes, and Vibrio cholerae were screened on a blood agar medium containing 0.1 mm PNPG, they displayed similar growth and hemolytic characteristics to the identical medium without PNPG. PMID:4715553

  2. 48 CFR 401.371 - AGAR Advisories.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false AGAR Advisories. 401.371... ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 401.371 AGAR Advisories. The SPE may issue AGAR Advisories, consistent with the policies of the FAR and the AGAR, for the following purposes: (a)...

  3. 48 CFR 401.371 - AGAR Advisories.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false AGAR Advisories. 401.371... ACQUISITION REGULATION SYSTEM Agency Acquisition Regulations 401.371 AGAR Advisories. The SPE may issue AGAR Advisories, consistent with the policies of the FAR and the AGAR, for the following purposes: (a)...

  4. Comparison of Citrated Human Blood, Citrated Sheep Blood, and Defibrinated Sheep Blood Mueller-Hinton Agar Preparations for Antimicrobial Susceptibility Testing of Streptococcus pneumoniae Isolates ▿

    PubMed Central

    Satzke, Catherine; Seduadua, Anna; Chandra, Reginald; Carapetis, Jonathan R.; Mulholland, E. Kim; Russell, Fiona M.

    2010-01-01

    The use of Mueller-Hinton agar supplemented with citrated human or citrated sheep blood was compared with the use of routinely used Mueller-Hinton agar supplemented with defibrinated sheep blood for antimicrobial susceptibility testing of Streptococcus pneumoniae. The alternate supplements were found to be unsatisfactory, particularly for testing resistant isolates, and therefore are not recommended. PMID:20668133

  5. Comparison of citrated human blood, citrated sheep blood, and defibrinated sheep blood Mueller-Hinton agar preparations for antimicrobial susceptibility testing of Streptococcus pneumoniae isolates.

    PubMed

    Satzke, Catherine; Seduadua, Anna; Chandra, Reginald; Carapetis, Jonathan R; Mulholland, E Kim; Russell, Fiona M

    2010-10-01

    The use of Mueller-Hinton agar supplemented with citrated human or citrated sheep blood was compared with the use of routinely used Mueller-Hinton agar supplemented with defibrinated sheep blood for antimicrobial susceptibility testing of Streptococcus pneumoniae. The alternate supplements were found to be unsatisfactory, particularly for testing resistant isolates, and therefore are not recommended.

  6. Recovery of Sublethally Injured Bacteria Using Selective Agar Overlays.

    ERIC Educational Resources Information Center

    McKillip, John L.

    2001-01-01

    This experiment subjects bacteria in a food sample and an environmental sample to conditions of sublethal stress in order to assess the effectiveness of the agar overlay method to recover sublethally injured cells compared to direct plating onto the appropriate selective medium. (SAH)

  7. Reduced supplementation frequency increased insulin-like growth factor 1 in beef steers fed medium quality hay and supplemented with a soybean hull and corn gluten feed blend.

    PubMed

    Drewnoski, M E; Huntington, G B; Poore, M H

    2014-06-01

    Reducing supplementation frequency in calf growing programs can reduce labor and equipment operation costs. However, little is understood about the metabolic response of ruminants to large fluctuations in nutrient intake. Eighteen Angus or Angus × Simmental cross steers (287 ± 20 kg and 310 ± 3.6 d of age) were individually fed 1 of 3 dietary treatments using Calan gates. Dietary treatments consisted of ad libitum hay and no supplement (NS), ad libitum hay and 1% BW (as-fed basis) of supplement daily (DS), or ad libitum hay and 2% BW (as-fed basis) of supplement every other day (SA). The supplement was 90% DM and contained (as-fed basis) 47% corn gluten feed, 47% soybean hulls, 2% feed grade limestone, and 4% molasses. Hay intake and ADG was measured over a 52-d period. Steers were then moved to individual tie stalls. Steers were fed at 0800 h and blood samples were collected every hour from 0600 to 1400 h and at 1800, 2200, and 0200 h over a 2-d period. Gains were increased (P < 0.01) by supplementation but did not differ (P = 0.68) due to supplementation frequency. Average daily gain was 0.45, 0.90, and 0.87 kg ·hd(-1)·d(-1) (SEM ± 0.05) for steers NS, DS, and SA, respectively. Across the 2-d supplementation cycle area under the concentration time curve (AUC) for plasma glucose was increased (P < 0.01) by supplementation but did not differ (P = 0.41) due to supplementation frequency. The AUC for plasma insulin was increased by supplementation (P < 0.01) but did not differ (P = 0.67) due to supplementation frequency. Plasma IGF-1 was increased (P = 0.01) by supplementation and was greater (P = 0.04) for steers supplemented SA than DS. Gains of steers supplemented with a soybean hull and corn gluten feed blend on alternate days did not differ from those supplemented daily suggesting the steers were able to efficiently utilize large boluses of nutrients fed every other day. The effect of less frequent supplementation on IGF-1 deserves further examination as

  8. Comparison of MRSASelect Agar, CHROMagar Methicillin-Resistant Staphylococcus aureus (MRSA) Medium, and Xpert MRSA PCR for Detection of MRSA in Nares: Diagnostic Accuracy for Surveillance Samples with Various Bacterial Densities ▿

    PubMed Central

    Wolk, D. M.; Marx, J. L.; Dominguez, L.; Driscoll, D.; Schifman, R. B.

    2009-01-01

    Rapid laboratory methods provide optimal support for active surveillance efforts to screen for methicillin-resistant Staphylococcus aureus (MRSA). Most laboratories struggle to determine the optimal use of resources, considering options to balance cost, speed, and diagnostic accuracy. To assess the performance of common methods, the first comparison of MRSASelect agar (MS) and CHROMagar MRSA (CA), with and without broth enrichment followed by a 24-h subculture to MS, was performed. Results were compared to those of the Xpert MRSA assay. For direct culture methods, the agreement between MS and CA was 98.8%. At 18 h, direct MS identified 93% of all positive samples from direct culture and 84% of those identified by the Xpert MRSA. For Trypticase soy broth-enriched MS culture, incubated overnight and then subcultured for an additional 24 h, the agreement with Xpert MRSA was 96%. The agreement between direct MS and Xpert MRSA was 100% when semiquantitative culture revealed a bacterial density of 2+ or greater; however, discrepancies between culture and Xpert MRSA arose for MRSA bacterial densities of 1+ or less, indicating low density as a common cause of false-negative culture results. Since 1+ or less was established as the most common MRSA carrier state, broth enrichment or PCR may be critical for the identification of all MRSA carriers who may be reservoirs for transmission. In this active-surveillance convenience sample, the use of broth enrichment followed by subculture to MS offered a low-cost but sensitive method for MRSA screening, with performance similar to that of Xpert MRSA PCR. PMID:19828738

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

    PubMed

    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. PMID:22563856

  10. Use of cefoperazone MacConkey agar for selective isolation of Laribacter hongkongensis.

    PubMed

    Lau, Susanna K P; Woo, Patrick C Y; Hui, Wai-ting; Li, Maria W S; Teng, Jade L L; Que, Tak-Lun; Luk, Wei-Kwang; Lai, Raymond W M; Yung, Raymond W H; Yuen, Kwok-yung

    2003-10-01

    A new selective medium, cefoperazone MacConkey agar (CMA), was developed for primary isolation of Laribacter hongkongensis from stool. Its performance in quantitative recovery and in a clinical evaluation of 4,741 human diarrheal stool specimens was superior to that of charcoal cefoperazone deoxycholate agar. In addition, with CMA, Arcobacter butzleri was unexpectedly isolated from the stools of six patients.

  11. Evaluation of a chromogenic agar for detection of group B streptococcus in pregnant women.

    PubMed

    Craven, Robin R; Weber, Carol J; Jennemann, Rebecca A; Dunne, W Michael

    2010-09-01

    We compared ChromID Strepto B agar (STRB; bioMérieux, Inc.), a selective and differential medium for group B streptococcus, with culture using neomycin-nalidixic acid agar (NNA) and LIM broth. STRB alone was more sensitive (87.7%) than NNA alone (79.0%), while each had a sensitivity of 100% when used in conjunction with LIM broth.

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

    PubMed

    Bosmans, L; De Bruijn, I; De Mot, R; Rediers, H; Lievens, B

    2016-08-01

    Agar-based screening assays are the method of choice when evaluating antagonistic potential of bacterial biocontrol-candidates against pathogens. We showed that when using the same medium, but different agar compositions, the activity of a bacterial antagonist against Agrobacterium was strongly affected. Consequently, results from in vitro screenings should be interpreted cautiously. PMID:27166668

  13. High Concentrations of Manganese in Mueller-Hinton Agar Increase MICs of Tigecycline Determined by Etest▿

    PubMed Central

    Fernández-Mazarrasa, Carlos; Mazarrasa, Olav; Calvo, Jorge; del Arco, Asunción; Martínez-Martínez, Luis

    2009-01-01

    MICs of tigecycline determined by Etest were 4 to 12 times (three ATCC strains) and 2 to 8 times (50 clinical isolates) higher in Mueller-Hinton agar from Merck than in Mueller-Hinton agar from either Oxoid or Difco. This was related to a much higher concentration of manganese in the medium from Merck. PMID:19144806

  14. Effect of Different Commerical Agar Preparations on the Inhibitory Activities of Phenols

    PubMed Central

    Sands, J. G.; Bennett, E. O.

    1966-01-01

    The minimal inhibitory concentrations of 11 phenolic inhibitors were compared in five commercial agars and in nutrient broth. It was found that the brand of agar affected the end point obtained for a particular inhibitor, and that the degree of antagonism varied with each compound studied. The results indicate that there are at least two deleterious factors present in agar, one of which is water-soluble and one which is not. The major portion of the total antagonism was due to the water-soluble factor, which could be removed by washing the agar in warm distilled water prior to use in the test medium. PMID:5959856

  15. Detection of toxigenic isolates of Aspergillus flavus and related species on coconut cream agar.

    PubMed

    Dyer, S K; McCammon, S

    1994-01-01

    A new readily-prepared medium, coconut cream agar, was developed for the detection of aflatoxin production by isolates of Aspergillus flavus and related species. Coconut cream agar, which comprised coconut cream (50%) and agar (1.5%), detected isolates of A. flavus more effectively than the synthetic media tested and was as effective as media containing desiccated coconut. Fluorescence colouring of colonies grown on coconut cream agar could be used to differentiate A. flavus from A. parasiticus and A. nomius. In addition, conidial colour of A. flavus and A. nomius was quite distinct from that of A. parasiticus.

  16. Enhanced production of prodigiosin-like pigment from Serratia marcescens SMdeltaR by medium improvement and oil-supplementation strategies.

    PubMed

    Wei, Yu-Hong; Chen, Wei-Chuan

    2005-06-01

    Serratia marcescens SMdeltaR, an SpnR-defective isogenic mutant of S. marcescens SS-1, was used to produce a prodigiosin-like pigment (PLP). Luria-Bertani (LB) broth, frequently used for prodigiosin biosynthesis with S. marcescens strains, was modified by increasing the concentrations of tryptone and yeast extract while completely removing NaCl from the medium. The resulting modified LB (MLB) medium achieved an almost 3.0-fold increase in PLP yield (152 mg l(-1)) when compared with the original LB broth. The addition of vegetable oils (2-6% [v/v]) to the fermentation broth markedly enhanced PLP production. PLP yields of 525, 579, and 790 mg l(-1) were obtained when the MLB medium was supplemented with 4% soybean oil, 4% olive oil and 6% sunflower oil, respectively. PLP production was found to be positively correlated with extracellular surface emulsification activity, suggesting a link between the PLP production and the presence of biosurfactant. This work shows that the optimal medium for PLP yield was sunflower oil (6%)-supplemented MLB medium, which resulted in an approximately 14-fold higher PLP yield than that in LB broth. Mass spectrometry and NMR analysis indicated that the PLP product is a prodigiosin derivative, called undecylprodigiosin.

  17. Absence of heat treatment of serum for culture medium supplementation does not adversely affect the outcome of in-vitro fertilization.

    PubMed

    Imoedemhe, D A; Sigue, A B; Pacpaco, E L; Olazo, A B; Luciano, E C

    1994-09-01

    This study was carried out to determine if not heat-treating serum prior to use for medium supplementation adversely affected in-vitro fertilization (IVF) of human oocytes. Morphologically mature human oocytes derived from 135 patients undergoing IVF treatment were studied. A total of 504 oocytes were incubated, inseminated and the resulting pronuclear oocytes cultured further in Earle's balanced salt solution (EBSS) supplemented with 10% non-heat-treated serum. Comparisons of fertilization rate and embryonic development were made between these and 687 control oocytes derived from the same patients but incubated, inseminated and resulting pronuclear oocytes cultured further in EBSS supplemented with 10% heat-treated serum. The fertilization rate of 74.4% (375/504) of oocytes handled in serum-supplemented medium that had not been heat-treated was significantly better than the rate of 67.7% (465/687) for controls (P < 0.0125). The proportion of pronucleate oocytes that cleaved was also significantly better in the non-heat-treated serum group: 270/300 (90%) versus 307/375 (81.8%) (P < 0.0025). There was no significant difference in the proportion of embryos with four or more cells at the time of embryo transfer. The results show that the absence of heat treatment of serum used to supplement culture medium has no adverse effect on the fertilization rate and short-term embryo development in vitro; hence we suggest that serum heat treatment is an unnecessary procedure and could be abandoned. PMID:7836531

  18. Detection of Activity Responsible for Induction of the Agrobacterium tumefaciens Virulence Genes in Bacteriological Agar.

    PubMed

    Loubens, I; Chilton, W S; Dion, P

    1997-11-01

    Agrobacterium tumefaciens C58 grown on acidic medium containing glucose and solidified with bacteriological agar expressed a virB::lacZ fusion. No expression of this fusion was observed on a similar medium which was solidified with purified agarose. The fraction from bacteriological agar which was responsible for vir gene induction was extracted with methanol and partially purified by preparative thin-layer chromatography. PMID:16535740

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

    PubMed Central

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

    2003-01-01

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

  20. Standardization of disk diffusion and agar dilution susceptibility tests for Neisseria gonorrhoeae: interpretive criteria and quality control guidelines for ceftriaxone, penicillin, spectinomycin, and tetracycline.

    PubMed Central

    Jones, R N; Gavan, T L; Thornsberry, C; Fuchs, P C; Gerlach, E H; Knapp, J S; Murray, P; Washington, J A

    1989-01-01

    A six-laboratory study developed a standardized method for determining the susceptibilities of Neisseria gonorrhoeae strains to penicillin, tetracycline, spectinomycin, and ceftriaxone. Three quality control organisms were also selected, and quality assurance guidelines were initially generated for the disk diffusion and agar dilution methods. The medium recommended for gonococcal susceptibility testing was GC agar with a defined "XV-like" supplement. The supplement should be free of cysteine, a component implicated in the inactivation of some newer beta-lactam compounds. Penicillin, tetracycline, spectinomycin, and ceftriaxone were stable in agar plates stored at 3 to 5 degrees C for at least 2 weeks. Numerous GC agar and drug disk lots were used during the trials without significant variation in test results. Several other gonococcal strains were recommended for additional medium quality assurance. The disk quality control zone limits were established for N. gonorrhoeae ATCC 49226 (formerly CDC F-18) and Staphylococcus aureus ATCC 25923. MIC quality control ranges were also developed for N. gonorrhoeae ATCC 49226 and S. aureus ATCC 29213. The interpretive criteria for penicillin were as follows: susceptibility, greater than or equal to 47 mm (diameter of inhibition zone) (less than or equal to 0.06 micrograms/ml [MIC]); resistance, less than or equal to 26 mm (greater than or equal to 2 micrograms/ml). For tetracycline they were as follows: susceptibility, greater than or equal to 38 mm (less than or equal to 0.25 microgram/ml); resistance, less than or equal to 30 mm (greater than or equal to 2 micrograms/ml). For spectinomycin they were as follows: susceptibility, >/= 18 mm (/= 128 micrograms/ml). For ceftriaxone susceptibility, the criterion was >/= 35 mm (

  1. Glucose-sucrose-potassium tellurite-bacitracin agar, an alternative to mitis salivarius-bacitracin agar for enumeration of Streptococcus mutans.

    PubMed Central

    Tanzer, J M; Börjesson, A C; Laskowski, L; Kurasz, A B; Testa, M

    1984-01-01

    An agar medium for selective recovery and enumeration of Streptococcus mutans was developed as an alternative to mitis salivarius-bacitracin (MSB) agar. Combinations of dyes, antibiotics, and tellurite were added to a nonselective medium which, because of its sucrose content, allowed easy recognition of S. mutans colonies. Candle jar incubation for 2 days, by comparison with anaerobic incubation, reduced background flora but did not diminish S. mutans recoveries from clinical samples. Quantitative comparisons were made of the simultaneous recoveries of a number of authentic S. mutans serotype representatives and fresh clinical isolates, using various glucose-sucrose-potassium tellurite-bacitracin (GSTB) formulations and mitis salivarius, MSB, and blood agars. Mitis salivarius counts were not detectably different from blood counts, but counts on MSB were distinctly lower. A formulation of the new medium containing 5% glucose 5% sucrose, 0.001% potassium tellurite, 0.3 U of bacitracin per ml (hence GSTB), and 2% agar gave recoveries nearly equal to those on mitis salivarius agar and much greater than those on MSB. The medium yielded readily recognized S. mutans colonies and facilitated detection of intracellular polysaccharide formers upon flooding with I2 reagent. Freshly isolated serotype c, E, and f colonies could often be distinguished from serotype d and g colonies, a distinction made reliable by testing for intracellular polysaccharide. A study of 300 salivary samples revealed GSTB to give significantly higher recoveries than MSB. About 72% of all samples were substantially underestimated for S. mutans with MSB, and 6.7% of samples were falsely negative for S. mutans with MSB. Recovery of background flora on GSTB was as low or lower than on MSB, and both types of agar could be stored for at least 9 weeks without notable change of selectivity. Thus, GSTB agar appears to be simple and reliable to use and requires no anaerobic incubation. Caution is voiced about

  2. [A new modification of Pizu's medium for the rapid identification of Corynebacterium diphtheriae based on the AGV medium].

    PubMed

    Fel'dman, Iu M; Makhaneva, L G; Liabakh, A I

    1989-01-01

    Various nutrient bases (dry nutrient agar, erythrol agar, medium for toxigenicity determination, casein-yeast and AGV media) have been examined to choose a base for Pizu's medium instead of agar D that is no longer manufactured. AGV medium has been found the best nutrient base. The method for the preparation of Pizu's medium has been simplified. The modified Pizu's medium permits the detection of cystinase in C: diphtheriae in 3-5 hrs both in pure and mixed cultures.

  3. Production of puerarin and isoflavones in cell suspension cultures of Pueraria lobata (Willd.): effects of medium supplementation with casein hydrolysate and coconut milk.

    PubMed

    Li, L; Zhang, C R

    2006-01-01

    Callus induced from leaf explants of Pueraria lobata seedlings were suspended in Gamborg B5 medium supplemented with 1 mg l(-1) 2,4-dichlorophenoxyacetic acid, 1 mg l(-1) naphthalene acetic acid, 0.5 mg l(-1) kinetin and 30 g l(-1) sucrose. The effects of coconut milk and casein hydrolysate (CH) on cell growth and yields of puerarin and isoflavones in cells suspension were studied. The contents of total isoflavones and puerarin in suspension cultures were determined by spectrophotometry and HPLC. Coconut milk (10%, filter sterilized) decreased the growth of cell cultures and the accumulation of total isoflavones, while 0.2% CH promoted the growth of cell cultures and the accumulation and release of puerarin and total isoflavones. The total yield of puerarin and isoflavones were 34% and 40.8% higher than in the control, respectively. The optimum medium for cell cultures of leaves of P. lobata seedlings was B5 liquid medium supplemented with 2% sucrose, 1.0 mg l(-1) 2,4-D, 1.0 mg l(-1) NAA, 0.5 mg l(-1) kinetin and 20 mg l(-1) CH. The procedure use is a potentially useful for the production of isoflavones. PMID:16850870

  4. Rapid Direct Testing of Susceptibility of Mycobacterium tuberculosis to Isoniazid and Rifampin on Nutrient and Blood Agar in Resource-Starved Settings

    PubMed Central

    Ikram, Aamer; Coban, Ahmet Yilmaz; Martin, Anandi

    2012-01-01

    In this study, we evaluated the performance of blood agar (by macroscopic growth) and nutrient agar (by a microcolony detection method) for drug susceptibility testing of Mycobacterium tuberculosis against rifampin (RIF) and isoniazid (INH), using 67 smear-positive sputum specimens. The direct proportion method on Lowenstein-Jensen (LJ) medium was used as the “gold standard.” Compared with LJ medium, results for both media were in 100% agreement for RIF, while for INH the agreement levels for blood agar and nutrient agar were 98% and 95%, respectively. Within 2 weeks, 100% of specimens yielded results on blood agar, while 96.8% of specimens yielded results on nutrient agar. Our study showed that blood agar and nutrient agar can be used as alternative media for direct susceptibility testing of RIF and INH, especially in resource-poor settings. PMID:22357498

  5. Rapid direct testing of susceptibility of Mycobacterium tuberculosis to isoniazid and rifampin on nutrient and blood agar in resource-starved settings.

    PubMed

    Satti, Luqman; Ikram, Aamer; Coban, Ahmet Yilmaz; Martin, Anandi

    2012-05-01

    In this study, we evaluated the performance of blood agar (by macroscopic growth) and nutrient agar (by a microcolony detection method) for drug susceptibility testing of Mycobacterium tuberculosis against rifampin (RIF) and isoniazid (INH), using 67 smear-positive sputum specimens. The direct proportion method on Lowenstein-Jensen (LJ) medium was used as the "gold standard." Compared with LJ medium, results for both media were in 100% agreement for RIF, while for INH the agreement levels for blood agar and nutrient agar were 98% and 95%, respectively. Within 2 weeks, 100% of specimens yielded results on blood agar, while 96.8% of specimens yielded results on nutrient agar. Our study showed that blood agar and nutrient agar can be used as alternative media for direct susceptibility testing of RIF and INH, especially in resource-poor settings.

  6. Tooth Tissue Engineering: The Importance of Blood Products as a Supplement in Tissue Culture Medium for Human Pulp Dental Stem Cells.

    PubMed

    Pisciolaro, Ricardo Luiz; Duailibi, Monica Talarico; Novo, Neil Ferreira; Juliano, Yara; Pallos, Debora; Yelick, Pamela Crotty; Vacanti, Joseph Phillip; Ferreira, Lydia Masako; Duailibi, Silvio Eduardo

    2015-11-01

    One of the goals in using cells for tissue engineering (TE) and cell therapy consists of optimizing the medium for cell culture. The present study compares three different blood product supplements for improved cell proliferation and protection against DNA damage in cultured human dental pulp stem cells for tooth TE applications. Human cells from dental pulp were first characterized as adult stem cells (ectomesenchymal mixed origin) by flow cytometry. Next, four different cell culture conditions were tested: I, supplement-free; II, supplemented with fetal bovine serum; III, allogeneic human serum; and IV, autologous human serum. Cultured cells were then characterized for cell proliferation, mineralized nodule formation, and colony-forming units (CFU) capability. After 28 days in culture, the comet assay was performed to assess possible damage in cellular DNA. Our results revealed that Protocol IV achieved higher cell proliferation than Protocol I (p = 0.0112). Protocols II and III resulted in higher cell proliferation than Protocol I, but no statistical differences were found relative to Protocol IV. The comet assay revealed less cell damage in cells cultured using Protocol IV as compared to Protocols II and III. The damage percentage observed on Protocol II was significantly higher than all other protocols. CFUs capability was highest using Protocol IV (p = 0.0018) and III, respectively, and the highest degree of mineralization was observed using Protocol IV as compared to Protocols II and III. Protocol IV resulted in significantly improved cell proliferation, and no cell damage was observed. These results demonstrate that human blood product supplements can be used as feasible supplements for culturing adult human dental stem cells.

  7. Ex vivo expanded autologous limbal epithelial cells on amniotic membrane using a culture medium with human serum as single supplement.

    PubMed

    Shahdadfar, Aboulghassem; Haug, Kristiane; Pathak, Meeta; Drolsum, Liv; Olstad, Ole Kristoffer; Johnsen, Erik O; Petrovski, Goran; Moe, Morten C; Nicolaissen, Bjørn

    2012-04-01

    In patients with limbal stem cell deficiency (LSCD), transplantation of ex vivo expanded human limbal epithelial cells (HLECs) can restore the structural and functional integrity of the corneal surface. However, the protocol for cultivation and transplantation of HLECs differ significantly, and in most protocols growth additives such as cholera toxins, exogenous growth factors, hormones and fetal calf serum are used. In the present article, we compare for the first time human limbal epithelial cells (HLECs) cultivated on human amniotic membrane (HAM) in a complex medium (COM) including fetal bovine serum to a medium with human serum as single growth supplement (HSM), and report on our first examinations of HLECs expanded in autologous HSM and used for transplant procedures in patients with LSCD. Expanded HLECs were examined by genome-wide microarray, RT-PCR, Western blotting, and for cell viability, morphology, expression of immunohistochemical markers and colony forming efficiency. Cultivation of HLECs in HSM produced a multilayered epithelium where cells with markers associated with LESCs were detected in the basal layers. There were few transcriptional differences and comparable cell viability between cells cultivated in HSM and COM. The p63 gene associated with LESCs were expressed 3.5 fold more in HSM compared to COM, and Western blotting confirmed a stronger p63α band in HSM cultures. The cornea-specific keratin CK12 was equally found in both culture conditions, while there were significantly more CK3 positive cells in HSM. Cells in epithelial sheets on HAM remaining after transplant surgery of patients with LSCD expressed central epithelial characteristics, and dissociated cells cultured at low density on growth-arrested fibroblasts produced clones containing 21 ± 12% cells positive for p63α (n = 3). In conclusion, a culture medium without growth additives derived from animals or from animal cell cultures and with human serum as single growth supplement

  8. A novel chemical-defined medium with bFGF and N2B27 supplements supports undifferentiated growth in human embryonic stem cells

    SciTech Connect

    Liu Yanxia; Song Zhihua; Zhao Yang; Qin Han; Cai Jun; Zhang Hong; Yu Tianxin; Jiang Siming; Wang Guangwen; Ding Mingxiao; Deng Hongkui . E-mail: hongkui_deng@pku.edu.cn

    2006-07-21

    Traditionally, undifferentiated human embryonic stem cells (hESCs) are maintained on mouse embryonic fibroblast (MEF) cells or on matrigel with an MEF-conditioned medium (CM), which hampers the clinical applications of hESCs due to the contamination by animal pathogens. Here we report a novel chemical-defined medium using DMEM/F12 supplemented with N2, B27, and basic fibroblast growth factor (bFGF) [termed NBF]. This medium can support prolonged self-renewal of hESCs. hESCs cultured in NBF maintain an undifferentiated state and normal karyotype, are able to form embryoid bodies in vitro, and differentiate into three germ layers and extraembryonic cells. Furthermore, we find that hESCs cultured in NBF possess a low apoptosis rate and a high proliferation rate compared with those cultured in MEF-CM. Our findings provide a novel, simplified chemical-defined culture medium suitable for further therapeutic applications and developmental studies of hESCs.

  9. Supplemented αMEM/F12-based medium enables the survival and growth of primary ovarian follicles encapsulated in alginate hydrogels

    PubMed Central

    Tagler, David; Makanji, Yogeshwar; Anderson, Nicholas R.; Woodruff, Teresa K.; Shea, Lonnie D.

    2013-01-01

    Hydrogel-encapsulating culture systems for ovarian follicles support the in vitro growth of secondary follicles from various species including mouse, non-primate human, and human; however, the growth of early stage follicles (primary and primordial) has been limited. While encapsulation maintains the structure of early stage follicles, feeder cell populations, such as mouse embryonic fibroblasts (MEFs), are required to stimulate growth and development. Hence, in this report, we investigated feeder-free culture environments for early stage follicle development. Mouse ovarian follicles were encapsulated within alginate hydrogels and cultured in various growth medium formulations. Initial studies employed embryonic stem cell medium formulations as a tool to identify factors that influence the survival, growth, and meiotic competence of early stage follicles. The medium formulation that maximized survival and growth was identified as αMEM/F12 supplemented with fetuin, insulin, transferrin, selenium, and follicle stimulating hormone (FSH). This medium stimulated the growth of late primary (average initial diameter of 80 µm) and early secondary (average initial diameter of 90 µm) follicles, which developed antral cavities and increased to terminal diameters exceeding 300 µm in 14 days. Survival ranged from 18% for 80 µm follicles to 36% for 90 µm follicles. Furthermore, 80% of the oocytes from surviving follicles with an initial diameter of 90–100 µm underwent germinal vesicle breakdown (GVBD), and the percentage of metaphase II (MII) eggs was 50%. Follicle/oocyte growth and GVBD/MII rates were not significantly different from MEF co-culture. Survival was reduced relative to MEF co-culture, yet substantially increased relative to the control medium that had been previously used for secondary follicles. Continued development of culture medium could enable mechanistic studies of early stage folliculogenesis and emerging strategies for fertility preservation. PMID

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

    PubMed

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

    2013-06-01

    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.

  11. Xanthan gum: an economical partial substitute for agar in microbial culture media.

    PubMed

    Babbar, Shashi B; Jain, Ruchi

    2006-04-01

    Xanthan gum, microbial desiccation-resistant polysaccharide prepared commercially by aerobic submerged fermentation from Xanthomonas campestris, has been successfully used alone and in combination with agar for microbial culture media. As illustrative examples, eight bacteria and eight fungi were grown on media solidified with either agar (A, 1.5%), xanthan gum (X, 1%), or combinations of both (0.9% X + 0.1% A, 0.8% X + 0.2% A, 0.7% X + 0.3% A, 0.6% X + 0.4% A). All fungi and bacteria exhibited normal growth and differentiation in all these treatments. Rather, growth of most of the fungi was better on xanthan (alone) and xanthan + agar media than agar medium. As the media gelled with xanthan gum alone flow, it was not possible to incubate Petri plates in inverted position. Moreover, because of the softness, streaking of bacteria was difficult on such media. However, these problems could be overcome by partially replacing xanthan gum with 0.3% agar. Bacterial enumeration studies carried out for Serratia sp. and Pseudomonas sp. by serial dilution and pour-plate method on agar (1.5%), 0.7%/0.6% X + 0.3%/0.4% A yielded similar counts. Selective media, succinate medium for Pseudomonas sp., and MacConkey broth medium for Escherichia coli gelled with 0.7%/0.6% X + 0.3%/0.4% A did not support growth of other bacteria when inoculated along with the above-mentioned bacteria. Likewise, differential medium, CRMA (Congo red mannitol agar) gelled with xanthan-agar combination could differentiate between Agrobacterium tumefaciens and Rhizobium sp.

  12. Agar polysaccharides from Gracilaria species (Rhodophyta, Gracilariaceae).

    PubMed

    Marinho-Soriano, E

    2001-07-26

    Yield, physical and chemical properties of agar from three agarophytes species (Gracilaria gracilis, G. dura and G. bursa-pastoris) were determined. The agar yield from the three species varied significantly (P<0.01). The highest yields of agar (34.8%) and the lowest (30%) were obtained from G. bursa-pastoris and G. gracilis, respectively. Highest gel strength (630+/-15 g cm(-2)) was obtained from agar extracted from G. gracilis and lowest from G. bursa-pastoris (26+/-3.6 g cm(-2)). The values of 3,6-anhydrogalactose were similar for G. gracilis and G. dura and there were no significant differences among the species. The sulfate contents varied significantly (P<0.01) and the higher value was obtained from G. bursa-pastoris. Among the three species, G. gracilis showed superior agar quality than the other two species, hence it can be considered a good potential source for industrial use.

  13. Effect of supplementing coconut or krabok oil, rich in medium-chain fatty acids on ruminal fermentation, protozoa and archaeal population of bulls.

    PubMed

    Panyakaew, P; Boon, N; Goel, G; Yuangklang, C; Schonewille, J Th; Hendriks, W H; Fievez, V

    2013-12-01

    Medium-chain fatty acids (MCFA), for example, capric acid (C10:0), myristic (C14:0) and lauric (C12:0) acid, have been suggested to decrease rumen archaeal abundance and protozoal numbers. This study aimed to compare the effect of MCFA, either supplied through krabok (KO) or coconut (CO) oil, on rumen fermentation, protozoal counts and archaeal abundance, as well as their diversity and functional organization. KO contains similar amounts of C12:0 as CO (420 and 458 g/kg FA, respectively), but has a higher proportion of C14:0 (464 v. 205 g/kg FA, respectively). Treatments contained 35 g supplemental fat per kg DM: a control diet with tallow (T); a diet with supplemental CO; and a diet with supplemental KO. A 4th treatment consisted of a diet with similar amounts of MCFA (i.e. C10:0+C12:0+C14:0) from CO and KO. To ensure isolipidic diets, extra tallow was supplied in the latter treatment (KO+T). Eight fistulated bulls (two bulls per treatment), fed a total mixed ration predominantly based on cassava chips, rice straw, tomato pomace, rice bran and soybean meal (1.5% of BW), were used. Both KO and CO increased the rumen volatile fatty acids, in particular propionate and decreased acetate proportions. Protozoal numbers were reduced through the supplementation of an MCFA source (CO, KO and KO+T), with the strongest reduction by KO. Quantitative real-time polymerase chain reaction assays based on archaeal primers showed a decrease in abundance of Archaea when supplementing with KO and KO+T compared with T and CO. The denaturing gradient gel electrophoresis profiles of the rumen archaeal population did not result in a grouping of treatments. Richness indices were calculated from the number of DGGE bands, whereas community organization was assessed from the Pareto-Lorenz evenness curves on the basis of DGGE band intensities. KO supplementation (KO and KO+T treatments) increased richness and evenness within the archaeal community. Further research including methane

  14. Development of a Plating Medium for Selection of Helicobacter pylori from Water Samples

    PubMed Central

    Degnan, A. J.; Sonzogni, W. C.; Standridge, J. H.

    2003-01-01

    The goal of this study was to develop a simple plating medium to allow large-scale screening of water samples for the presence of Helicobacter pylori. Five conventional plating media (brain heart infusion, brucella agar, Columbia blood agar base, campylobacter agar kit Skirrow, and HPSPA medium), each containing a commercial antibiotic supplement, were initially evaluated. Eight strains selected as common waterborne organisms (Acinetobacter, Aeromonas, Bacillus, Escherichia coli, Enterobacter, Enterococcus, Helicobacter pylori, and Pseudomonas strains) were individually plated onto each of these media. Three organisms (Acinetobacter, E. coli, and H. pylori) were able to grow on all five media. This growth was unacceptable since Helicobacter grows very slowly and competing organisms must be inhibited for up to 7 days. Therefore, a more selective medium (HP agar) containing a novel mixture of growth supplements plus amphotericin B and polymyxin B was developed. This medium also included a phenol red color indicator for urease production. Aliquots of nonsterile well water that contained native flora (Flavobacterium, Serratia, Citrobacter, Pasteurella, Ochrobactrum, Rahnella, and unidentified molds) and were further adulterated with the eight strains listed above (106 CFU of each strain per 100 ml) were spiked with H. pylori and were plated. In spite of the heavy mixed microbial load, only H. pylori colonies grew during 7 days of incubation at 37°C. The color indicator system allowed presumptive identification of H. pylori colonies sooner (12 to 20 h) than the conventional media tested allowed. The HP formulation developed in this study provides a medium with superior selectivity for H. pylori from mixed microbial populations in water and reduces the time required to complete the assay. PMID:12732566

  15. Evaluation of an automated agar plate streaker.

    PubMed Central

    Tilton, R C; Ryan, R W

    1978-01-01

    An automated agar plate streaker was evaluated. The Autostreaker mechanizes the agar plate streaking process by providing storage for plates, labeling and streaking one or more plates for either isolation or quantitation, and stacking in one of several racks for subsequent incubation. Results showed the Autostreaker to produce agar plates with well-separated colonies and accurate colony counts. A total of 1,930 clinical specimens were processed either in parallel with manual methods or solely by the Autostreaker. Technologist acceptance of machine-streaked plates was outstanding. Images PMID:348722

  16. A novel agar formulation for isolation and direct enumeration of Vibrio vulnificus from oyster tissue.

    PubMed

    Griffitt, Kimberly J; Grimes, D Jay

    2013-08-01

    A new selective and differential medium, Vibrio vulnificus X-Gal (VVX), was developed for direct enumeration of V. vulnificus (Vv) from oyster samples. This agar utilizes cellobiose and lactose as carbon sources, and the antibiotics colistin and polymyxin B as selective agents. Hydrolysis of 5-bromo-4-chloro-3-indolyl- beta-d-galactopyranoside (x-gal), used in the agar as a lactose analog, produces an insoluble blue dye that makes lactose positive colonies easily distinguishable from any non-lactose fermenting bacteria. Various bacterial species were spot plated onto thiosulfate-citrate-bile salts-sucrose agar (TCBS), and CHROMagar Vibrio, two vibrio-specific selective agars, non-selective agar, and VVX to compare selectivity of VVX to other widely used media. A V. vulnificus pure culture was serially diluted on VVX and non-selective agar to determine the VVX percent recovery. Water and oyster samples were spread plated on VVX agar and allowed to incubate for 16-18 h at 33 °C. Blue and white colonies from VVX agar were picked and screened by end point PCR for the Vv hemolysin vvhA. VVX agar showed a significant improvement over TCBS and CHROMagar at preventing non-target growth. There was an 87.5% recovery compared to non-selective plating and a 98% positivity rate of blue colonies picked from oyster tissue plating. The findings suggest that this new agar is a fast, distinctive, and accurate method for enumeration of V. vulnificus from the environment.

  17. Characterization of physicochemical properties of carboxymethyl agar.

    PubMed

    Cao, Mingzhao; Liu, Xin; Luan, Jimei; Zhang, Xiaodong

    2014-10-13

    A series of carboxymethyl agars (CMAs) with different degree of substitution (DS) were prepared, and their properties were determined and analyzed. The results showed that with the increase of DS, the dissolving temperature, the gelling temperature, the gel melting temperature, the gel strength, the gel hardness, the gel fracturability, and the solution apparent viscosity of CMA all decreased, except that its gel cohesiveness and gel springiness increased. The variation process of agar molecules in solution from coil to helix could be observed by measuring the optical rotation of the solution at such a low concentration, at which even the solution could not form a gel. The gel skeleton microstructures of both agar and CMA were of porous network structure, and the pore size of CMA became smaller and denser with the increase of its DS. After carboxymethylation, the agar hygroscopicity was improved, but its thermal stability was lowered.

  18. Serial cultivation of suspended BHK 21/13 cells in serum-reduced and serum-free medium supplemented with various membrane protective agents.

    PubMed

    Gürhan, S I; Ozdural, N

    1990-01-01

    Suspended BHK 21/13 cells were cultivated in 6M medium supplemented with PVP, bovine serum, LAH, YE, choline chloride and inositol at several concentrations. The maximum working capacity of the bioreactors was 400 ml and the experiments were run for 40 days. The growth promoting effects of each substrate were determined by calculation of generation numbers (n) in each culture. Viability testing and morphological detection of the cells were realized by the trypan blue exclusion method. As a result, the membrane protective effect of PVP, as suggested by some authors, was confirmed and it was estimated that the positive effects of PVP on cell propagation in cultures were due to its protective activities.

  19. Blood agar validation for susceptibility testing of isoniazid, rifampicin, ethambutol, and streptomycin to Mycobacterium tuberculosis isolates.

    PubMed

    Coban, Ahmet Yilmaz

    2013-01-01

    In recent studies, it was shown that blood agar can be used at least as effectively as Löwenstein-Jensen medium for growing Mycobacterium tuberculosis. It was also shown that susceptibility testing can be performed on blood agar. Additional validation of blood agar was performed on regional M. tuberculosis isolates from Turkey to determine critical concentrations of isoniazid (INH), rifampicin (RIF), ethambutol (ETM), and streptomycin (STR). In the current study, 40 M. tuberculosis clinical isolates were tested. H37Rv, which is susceptible to all antituberculosis agents, ATCC 35822 (INH-resistant), ATCC 35838 (RIF-resistant), ATCC 35837 (ETM-resistant), and ATCC 35820 (STR-resistant) quality control strains were used as control strains. Proportion method on 7H11 agar was considered as gold standard in the study. MIC values of the control strains and clinical isolates were detected on blood and 7H11 agar. Categorical agreements were 100% for each antibiotic, and essential agreements were 100%, 97.5%, 82.5%, and 95% for INH, RIF, ETM, and STR, respectively. According to the data, 0.2 µg/mL for INH, 1 µg/mL for RIF, 4 µg/mL for ETM, and 2 µg/mL for STR were appropriate breakpoint values for susceptibility testing on blood agar. Blood agar may be recommended for use in both developed and developing countries for the susceptibility testing of M. tuberculosis isolates to primary antituberculosis drugs.

  20. A solid agar overlay method for recovery of heat-injured Listeria monocytogenes.

    PubMed

    Yan, Zhinong; Gurtler, Joshua B; Kornacki, Jeffrey L

    2006-02-01

    A solid agar overlay method was developed for recovery of heat-injured Listeria monocytogenes. Presolidified nonselective tryptic soy agar with 0.6% yeast extract (TSAYE, 2% agar) was overlaid on top of solidified modified Oxford agar (MOX). Heat injury of L. monocytogenes was conducted at 58 degrees C for 6 min in a jacketed flask filled with tryptic soy broth. Both noninjured and heat-treated L. monocytogenes cells were plated onto TSAYE, MOX, and TSAYE-MOX plates. No significant differences (P > 0.05) in recovery were found among the three media for noninjured bacterial cells. Recovery of heat-injured L. monocytogenes cells on TSAYE-MOX overlay plates was equivalent to that on the nonselective TSAYE medium, whereas recovery on the selective MOX medium was significantly lower (P < 0.05) compared with both TSAYE and the overlay plates. There were no significant differences (P > 0.05) among the overlay plates prepared 0, 2, 4, 6, 8, 16, and 24 h prior to plating heat-injured bacterial cells. The TSAYE-MOX overlay also allowed differentiation of L. monocytogenes from a mixture of four other types of foodborne pathogens. This solid agar overlay method for recovery of heat-injured L. monocytogenes cells is less time-consuming and less complicated than the conventional overlay-underlay technique and the double overlay modification of the thin agar layer method and may allow for greater laboratory plating efficiencies.

  1. Development of a New Semiselective Medium for Isolating Xanthomonas campestris pv. manihotis from Plant Material and Soil.

    PubMed

    Fessehaie, A; Wydra, K; Rudolph, K

    1999-07-01

    ABSTRACT An effective control for bacterial blight of cassava (Manihot esculenta), caused by Xanthomonas campestris pv. manihotis, requires the use of non-contaminated cuttings and seeds. Using classical agar plating techniques for screening planting material for contamination has not been very successful because of the lack of a reliable semiselective agar medium. The pathogen grows slowly on general plating media and is easily overgrown by saprophytic bacteria during isolation from diseased plants. In an effort to develop a semiselective medium, the utilization of several carbon and nitrogen sources was studied. Results of these tests provided information used to design a basal medium allowing good growth of the target organism while suppressing growth of several common saprophytes. Additional selectivity was achieved by incorporating three antibiotics into the basal medium. The new semiselective agar medium, designated cefazolin trehalose agar (CTA) medium, contained (per liter) 3.0 g of K(2)HPO(4), 1.0 g of NaH(2)PO(4), 0.3 g of MgSO(4).7H(2)O, 1.0 g of NH(4)Cl, 9.0 g of D(+)-trehalose, 1.0 D(+)-glucose, 1.0 g of yeast extract, 0.025 g of cefazolin, 0.0012 g of lincomycin, 0.0025 g of phosphomycin, 0.25 g of cycloheximide, and 14.0 g of agar. In comparison to a starch-based semiselective medium (SXM), plating efficiencies using pure cultures of 10 strains of X. campestris pv. manihotis were significantly higher on CTA, with an average of 85 and 50%, respectively. Likewise, isolation and recovery of X. campestris pv. manihotis from infected cassava leaves and contaminated soil were much higher on CTA than on SXM agar. When X. campestris pv. manihotis occurs in high concentrations in diseased tissue, the standard yeast trehalose glucose agar medium supplemented with 250 mug of cycloheximide per ml appears to be satisfactory. The newly developed CTA medium should prove useful for control strategies to identify and remove infected planting material of cassava, as

  2. Improvement of hepatocyte viability after cryopreservation by supplementation of long-chain oligosaccharide in the freezing medium in rats and humans.

    PubMed

    Miyamoto, Yoshitaka; Suzuki, Satoshi; Nomura, Kou; Enosawa, Shin

    2006-01-01

    Factors affecting cell viability, plating efficiency, and survival of hepatocytes after cryopreservation have been investigated. We focused especially on the effect of including trehalose and related oligosaccharides in the cryopreservation fluid. This was supplemented with either glucose, trehalose, maltotriose, or other sugars, in addition to dimethyl sulfoxide (10%) and first tested with primary rat hepatocytes cooled in a controlled rate freezer. After thawing, viability by trypan blue exclusion of cells frozen in oligosaccharide-supplemented medium was significantly higher than for those cryopreserved without oligosaccharides. Use of oligosaccharides with higher molecular weights resulted in greatest improvement in viability. Moreover, attachment and survival rates in plastic dishes were approximately 1.2-1.8-fold greater after freezing in the presence of di-, tri-, and tetrasaccharides. Human hepatocytes isolated from untransplantable liver showed the same tendency regarding viability, but cell adherence was not similarly improved by the addition of oligosaccharides. Possible reasons for these differences may be prior cell damage during extended cold ischemia of the human liver, donor age, or cell degradation caused by progression of fatty liver in humans, and/or species differences.

  3. Comparison of mupirocin-based media for selective enumeration of bifidobacteria in probiotic supplements.

    PubMed

    Bunesova, Vera; Musilova, Sarka; Geigerova, Martina; Pechar, Radko; Rada, Vojtech

    2015-02-01

    An international standard already exists for the selective enumeration of bifidobacteria in milk products. This standard uses Transgalactosylated oligosaccharides (TOS) propionate agar supplemented with mupirocin. However, no such standard method has been described for the selective enumeration of bifidobacteria in probiotic supplements, where the presence of bifidobacteria is much more variable than in milk products. Therefore, we enumerated bifidobacteria by colony count technique in 13 probiotic supplements using three media supplemented with mupirocin (Mup; 100mg/l): TOS, Bifidobacteria selective medium (BSM) and modified Wilkins-Chalgren anaerobe agar with soya peptone (WSP). Moreover, the potential growth of bifidobacterial strains often used in probiotic products was performed in these media. All 13 products contained members of the genus Bifidobacterium, and tested mupirocin media were found to be fully selective for bifidobacteria. However, the type strain Bifidobacterium bifidum DSM 20456 and collection strain B. bifidum DSM 20239 showed statistically significant lower counts on TOS Mup media, compared to BSM Mup and WSP Mup media. Therefore, the TOS Mup medium recommended by the ISO standard cannot be regarded as a fully selective and suitable medium for the genus Bifidobacterium. In contrast, the BSM Mup and WSP Mup media supported the growth of all bifidobacterial species.

  4. FSH supplementation to culture medium is beneficial for activation and survival of preantral follicles enclosed in equine ovarian tissue.

    PubMed

    Aguiar, F L N; Lunardi, F O; Lima, L F; Rocha, R M P; Bruno, J B; Magalhães-Padilha, D M; Cibin, F W S; Nunes-Pinheiro, D C S; Gastal, M O; Rodrigues, A P R; Apgar, G A; Gastal, E L; Figueiredo, J R

    2016-04-01

    This study investigated the effect of adding different concentrations of bovine recombinant follicle-stimulating hormone on the IVC of equine preantral follicles enclosed in ovarian tissue fragments. Randomized ovarian fragments were fixed immediately (fresh noncultured control) or cultured for 1 or 7 days in α-MEM(+) supplemented with 0, 10, 50, and 100 ng/mL FSH and subsequently analyzed by classical histology. Culture media collected on Day 1 or Day 7 and were analyzed for steroids (estradiol and progesterone) and reactive oxygen species (ROS). After Day 1 and Day 7 of culture, 50-ng/mL FSH treatment had a greater (P < 0.05) percentage of morphologically normal follicles when compared to the other groups, except the 10-ng/mL FSH treatment at Day 1 of culture. The percentage of developing follicles (transition, primary, and secondary), and follicular and oocyte diameters were higher (P < 0.05) in the 50-ng/mL FSH treatment compared to the other groups after Day 7 of culture. Furthermore, estradiol secretion and ROS production were maintained (P > 0.05) throughout the culture in the 50-ng/mL FSH treatment. In conclusion, the addition of 50 ng/mL of FSH promoted activation of primordial follicles to developing follicles, improved survival of preantral follicles, and maintained estradiol and ROS production of equine ovarian tissue after 7 days of culture.

  5. Effect of medium variations (zinc supplementation during oocyte maturation, perifertilization pH, and embryo culture protein source) on equine embryo development after intracytoplasmic sperm injection.

    PubMed

    Choi, Young-Ho; Gibbons, John R; Canesin, Heloísa S; Hinrichs, Katrin

    2016-10-15

    Prospective studies were conducted to help define procedural factors affecting in vitro embryo production via intracytoplasmic sperm injection (ICSI) of equine oocytes. In experiment 1, use of 10% fetal bovine serum as a protein source in embryo culture medium resulted in a higher blastocyst rate than did use of a combination of 3% fetal bovine serum, 3% equine preovulatory follicular fluid, and 4% human serum substitute (37% vs. 15%, respectively, P < 0.05). In experiment 2, the effect of zinc supplementation (0, 0.5, 1, or 1.5 μg/mL) during IVM was examined. There were no significant differences in rates of cleavage or blastocyst development (20%-31%). However, the proportion of blastocysts that developed on Day 7 for the added-zinc treatments was significantly higher than that for the control treatment (45% vs. 8%). In experiment 3, we tested whether use of high-pH medium (pH 8.0-8.4) during ICSI procedures would improve blastocyst rate when sperm with low cleavage rates after ICSI was used. When high-pH conditions were used for sperm preparation and also for the first 2 hours of incubation of injected oocytes after ICSI, the cleavage rate was unaffected but no blastocysts developed (0% vs. 24% for control). When high-pH conditions were used for sperm preparation only, the blastocyst rate was 37%. This was repeated using sperm from a second stallion; there was no significant difference in cleavage or blastocyst rates between sperm preparation in high pH vs. control medium. These findings add to our knowledge of factors affecting in vitro production of equine embryos.

  6. [Presumptive identification of Candida spp. and other clinically important yeasts: usefulness of Brilliance Candida Agar].

    PubMed

    Alfonso, Claudia; López, Mónica; Arechavala, Alicia; Perrone, María Del Carmen; Guelfand, Liliana; Bianchi, Mario

    2010-06-30

    Fungal infections caused by yeasts have increased during the last decades and invasive forms represent a serious problem for human health. Candida albicans is the species most frequently isolated from clinical samples. However, other emerging yeast pathogens are increasingly responsible for mycotic infections, and some of them are resistant to some antifungal drugs. Consequently, it is necessary to have methods that can provide a rapid presumptive identification at species level. Numerous chromogenic agar media have been shown to be of value as diagnostic tools. We have compared a chromogenic medium, Brilliance Candida Agar, with CHROMagar Candida, the chromogenic medium most used in our country. A multicentre study was conducted in 16 Hospitals belonging to the Mycology Net of Buenos Aires City Government. A total of 240 yeast isolates were included in this research. The new chromogenic agar showed results very similar to those obtained with CHROMagar Candida.

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

    PubMed

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

    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.

  8. [An oropharyngeal tularemia case diagnosed by the isolation of Francisella tularensis on human blood agar].

    PubMed

    Ozel, Gönül; Arslan, Ilker Burak; Yeşilyurt, Murat; Celebi, Bekir; Kılıç, Selçuk

    2010-10-01

    Tularemia which is a multisystem disease of humans and some animals, is endemic in North America, some parts of Europe and Asia. The causative agent, Francisella tularensis, is a fastidious gram-negative, intracellular bacterium which requires supplementation with sulphydryl compounds (cysteine, cystine, thiosulphate, isoVitaleX) for growth on common laboratory media. In this report, a case of oropharyngeal tularemia diagnosed by the isolation of the causative agent on non-selective-common microbiological agar, has been presented. The patient was from Yozgat located in central Anatolia where tularemia has not been reported so far. Forty-two years old male was admitted to the hospital with two weeks history of sudden onset fever, headache, generalized aches, sore throat, and cervical tender lump on the left. Physical examination revealed bilateral exudative tonsillitis and tender posterior cervical lymphadenopathy. He has been empirically treated with amoxicilin-clavulanic acid for 7 days with initial diagnosis of acute tonsillopharyngitis. However, he was admitted to the hospital since the symptoms persisted and swelling increased despite antibiotic therapy. Microscopical examination of the Gram and Ehrlich-Ziehl-Neelsen stained smears prepared from the surgically drained lymph node revealed PMNL, with no evidence of bacteria. Routine cultures of the lymph node material yielded growth of gram-negative coccobacilli only on human blood agar and the cultures were negative for pyogenic bacteria, acid-fast organisms and fungi. Pathologic examination of the drainage material revealed suppurative inflammation. Lymph node aspirate and serum samples of the patient together with the isolated strain were sent to reference laboratory for further investigation in accordance to the clinical and laboratory findings compatible with tularemia. The isolate was confirmed as F.tularensis by slide agglutination and direct immunofluorescence antibody tests, and identified as F

  9. [An oropharyngeal tularemia case diagnosed by the isolation of Francisella tularensis on human blood agar].

    PubMed

    Ozel, Gönül; Arslan, Ilker Burak; Yeşilyurt, Murat; Celebi, Bekir; Kılıç, Selçuk

    2010-10-01

    Tularemia which is a multisystem disease of humans and some animals, is endemic in North America, some parts of Europe and Asia. The causative agent, Francisella tularensis, is a fastidious gram-negative, intracellular bacterium which requires supplementation with sulphydryl compounds (cysteine, cystine, thiosulphate, isoVitaleX) for growth on common laboratory media. In this report, a case of oropharyngeal tularemia diagnosed by the isolation of the causative agent on non-selective-common microbiological agar, has been presented. The patient was from Yozgat located in central Anatolia where tularemia has not been reported so far. Forty-two years old male was admitted to the hospital with two weeks history of sudden onset fever, headache, generalized aches, sore throat, and cervical tender lump on the left. Physical examination revealed bilateral exudative tonsillitis and tender posterior cervical lymphadenopathy. He has been empirically treated with amoxicilin-clavulanic acid for 7 days with initial diagnosis of acute tonsillopharyngitis. However, he was admitted to the hospital since the symptoms persisted and swelling increased despite antibiotic therapy. Microscopical examination of the Gram and Ehrlich-Ziehl-Neelsen stained smears prepared from the surgically drained lymph node revealed PMNL, with no evidence of bacteria. Routine cultures of the lymph node material yielded growth of gram-negative coccobacilli only on human blood agar and the cultures were negative for pyogenic bacteria, acid-fast organisms and fungi. Pathologic examination of the drainage material revealed suppurative inflammation. Lymph node aspirate and serum samples of the patient together with the isolated strain were sent to reference laboratory for further investigation in accordance to the clinical and laboratory findings compatible with tularemia. The isolate was confirmed as F.tularensis by slide agglutination and direct immunofluorescence antibody tests, and identified as F

  10. Standard operating procedure to prepare agar phantoms

    NASA Astrophysics Data System (ADS)

    Souza, R. M.; Santos, T. Q.; Oliveira, D. P.; Souza, R. M.; Alvarenga, A. V.; Costa-Felix, R. P. B.

    2016-07-01

    Agar phantoms are widely used as soft tissue mimics and some preparation techniques are described in the literature. There are also standards that describe the recipe of a soft tissue mimicking material (TMM). However some details of manufacture process are not clearly defined. The standardization of the phantom's preparation can produce a metrological impact on the results of the acoustic properties measured. In this direction, this paper presents a standard operating procedure (SOP) to prepare the agar TMM described on the IEC 60601-237.

  11. Susceptibilities of Mycobacterium tuberculosis to isoniazid and rifampin on blood agar.

    PubMed

    Coban, Ahmet Yilmaz; Bilgin, Kemal; Uzun, Meltem; Tasdelen Fisgin, Nuriye; Akgunes, Alper; Cihan, Cigdem Cekic; Birinci, Asuman; Durupinar, Belma

    2005-04-01

    In this study, blood agar was used instead of 7H10 agar for the susceptibility testing of 34 clinical isolates of Mycobacterium tuberculosis to isoniazid (INH) and rifampin (RIF) in accordance with the NCCLS. The BACTEC 460 TB system (Becton Dickinson, Sparks, Md.) was used as a "gold standard." Results for both media were in agreement for RIF and INH at 100 and 94.1%, respectively. For INH, the specificity, sensitivity, positive predictive value, and negative predictive value were found to be 71.4, 100, 93.1, and 100%, respectively, while these values were 100% for RIF. In addition, the results of the susceptibility test performed with blood agar were obtained on day 14 of incubation. In conclusion, results were obtained much earlier with blood agar (2 weeks) than with 7H10 agar (3 weeks), and the results of this study suggest that blood agar may be used as an alternative medium for the susceptibility testing of M. tuberculosis to INH and RIF.

  12. Use of agar agar stabilized milled zero-valent iron particles for in situ groundwater remediation

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    A major obstacle for use of nanoscale zero-valent iron (nZVI) particles as a nontoxic material for effective in situ degradation of chlorinated aliphatic hydrocarbons (CAHs) is the high production cost. For that reason, submicro-scale milled zero-valent iron particles were recently developed (milled ZVI, UVR-FIA, Germany) by grinding macroscopic raw materials of elementary iron as a cheaper alternative to products produced by solid-state reduction. However, milled ZVI particles tend to aggregate and due to the rather large particle size (d50= 11.9 µm) also rapidly sediment. To prevent aggregation and consequently sedimentation of milled ZVI particles and therefore improve the mobility after in situ application, the use of a stabilizer is considered in literature as a most promising option. In this study, milled ZVI particles (1 g L-1 of particle concentration) were stabilized by environmentally friendly polymer agar agar (>0.5 g L-1), which had a positive impact on the milled ZVI stability. Sedimentation rate was significantly decreased by increasing the suspension viscosity. Column transport experiments were performed for bare and agar agar stabilized milled ZVI particles in commercially available fine grained quartz sand (DORSILIT® Nr.8, Gebrüder Dorfner GmbH Co, Germany) and different porous media collected from brownfields. The experiments were carried out under field relevant injection conditions of 100 m d-1. The maximal travel distance (LT) of less than 10 cm was determined for non-stabilized suspension in fine grained quartz sand, while agar agar (1 g L-1) stabilized milled ZVI suspension revealed LT of 12 m. Similar results were observed for porous media from brownfields showing that mobility of agar agar stabilized particle suspensions was significantly improved compared to bare particles. Based on the mobility data, agar agar stabilized milled zero-valent iron particles could be used for in situ application. Finally, lab-scale batch degradation

  13. Luminescent DNA- and agar-based membranes.

    PubMed

    Leones, R; Fernandes, M; Ferreira, R A S; Cesarino, I; Lima, J F; Carlos, L D; Bermudez, V de Zea; Magon, C J; Donoso, J P; Silva, M M; Pawlicka, A

    2014-09-01

    Luminescent materials containing europium ions are investigated for different optical applications. They can be obtained using bio-macromolecules, which are promising alternatives to synthetic polymers based on the decreasing oil resources. This paper describes studies of the DNA- and Agar-europium triflate luminescent membranes and its potential technological applications are expanded to electroluminescent devices. Polarized optical microscopy demonstrated that the samples are birefringent with submicrometer anisotropy. The X-ray diffraction analysis revealed predominantly amorphous nature of the samples and the atomic force microscopy images showed a roughness of the membranes of 409.0 and 136.1 nm for the samples of DNA10Eu and Agar1.11Eu, respectively. The electron paramagnetic resonance spectra of the DNA(n)Eu membranes with the principal lines at g ≈ 2.0 and g ≈ 4.8 confirmed uniform distribution of rare earth ions in a disordered matrix. Moreover, these strong and narrow resonance lines for the samples of DNA(n)Eu when compared to the Agar(n)Eu suggested a presence of paramagnetic radicals arising from the DNA matrix. The emission spectra suggested that the Eu3+ ions occupy a single local environment in both matrices and the excitation spectra monitored around the Eu emission lines pointed out that the Eu3+ ions in the Agar host were mainly excited via the broad band component rather than by direct intra-4f(6) excitation, whereas the opposite case occurred for the DNA-based sample.

  14. A new membrane filtration medium for simultaneous detection and enumeration of Escherichia coli and total coliforms.

    PubMed Central

    Grant, M A

    1997-01-01

    Recovery of total coliforms and Escherichia coli on a new membrane filtration (MF) medium was evaluated with 25 water samples from seven states. Testing of the new medium, m-ColiBlue24 broth, was conducted according to a U.S. Environmental Protection Agency protocol. For comparison, this same protocol was used to measure recovery of total coliforms and E. coli with two standard MF media, m-Endo broth and mTEC broth. E. coli recovery on the new medium was also compared to recovery on nutrient agar supplemented with 4-methylumbelliferyl-beta-D-glucuronide. Comparison of specificity, sensitivity, false positive error, undetected target error, and overall agreement indicated E. coli recovery on m-ColiBlue24 was superior to recovery on mTEC for all five parameters. Recovery of total coliforms on the new medium was comparable to recovery on m-Endo. PMID:9293003

  15. Use of prawn blood agar hemolysis to screen for bacteria pathogenic to cultured tiger prawns Penaeus monodon.

    PubMed

    Chang, C I; Liu, W Y; Shyu, C Z

    2000-11-14

    A newly developed prawn blood agar consisting of 1 ml of tiger prawn hemolymph in medium containing 200 ppm Rose Bengal was used to determine the hemolytic activity of 35 isolates of bacteria obtained from cultured tiger prawns Penaeus monodon and their rearing water. For comparison, the hemolytic activity of these isolates was also determined in sheep blood agar. Nine isolates (25.7% of total) showed different hemolytic reactions on prawn blood agar and sheep blood agar. From the 35 isolates, 8 with various hemolytic characteristics were selected and the relationship between the type of hemolytic activity and pathogenicity was determined and compared. Four isolates that showed hemolytic activity in prawn blood agar caused high mortality to cultured tiger prawns. By contrast, a significantly lower mortality rate was observed for tiger prawns injected with 4 isolates that did not exhibit hemolytic activity on prawn blood agar. Results further showed that mortality did not correlate with hemolytic activity determined using sheep blood agar. Prawn blood agar containing P. monodon hemocytes was faster and more accurate for determining prawn hemolytic activity of bacterial isolates.

  16. Use of prawn blood agar hemolysis to screen for bacteria pathogenic to cultured tiger prawns Penaeus monodon.

    PubMed

    Chang, C I; Liu, W Y; Shyu, C Z

    2000-11-14

    A newly developed prawn blood agar consisting of 1 ml of tiger prawn hemolymph in medium containing 200 ppm Rose Bengal was used to determine the hemolytic activity of 35 isolates of bacteria obtained from cultured tiger prawns Penaeus monodon and their rearing water. For comparison, the hemolytic activity of these isolates was also determined in sheep blood agar. Nine isolates (25.7% of total) showed different hemolytic reactions on prawn blood agar and sheep blood agar. From the 35 isolates, 8 with various hemolytic characteristics were selected and the relationship between the type of hemolytic activity and pathogenicity was determined and compared. Four isolates that showed hemolytic activity in prawn blood agar caused high mortality to cultured tiger prawns. By contrast, a significantly lower mortality rate was observed for tiger prawns injected with 4 isolates that did not exhibit hemolytic activity on prawn blood agar. Results further showed that mortality did not correlate with hemolytic activity determined using sheep blood agar. Prawn blood agar containing P. monodon hemocytes was faster and more accurate for determining prawn hemolytic activity of bacterial isolates. PMID:11145455

  17. Comparison of Fecal Coliform Agar and Violet Red Bile Lactose Agar for Fecal Coliform Enumeration in Foods

    PubMed Central

    Leclercq, A.; Wanegue, C.; Baylac, P.

    2002-01-01

    A 24-h direct plating method for fecal coliform enumeration with a resuscitation step (preincubation for 2 h at 37 ± 1°C and transfer to 44 ± 1°C for 22 h) using fecal coliform agar (FCA) was compared with the 24-h standardized violet red bile lactose agar (VRBL) method. FCA and VRBL have equivalent specificities and sensitivities, except for lactose-positive non-fecal coliforms such as Hafnia alvei, which could form typical colonies on FCA and VRBL. Recovery of cold-stressed Escherichia coli in mashed potatoes on FCA was about 1 log unit lower than that with VRBL. When the FCA method was compared with standard VRBL for enumeration of fecal coliforms, based on counting carried out on 170 different food samples, results were not significantly different (P > 0.05). Based on 203 typical identified colonies selected as found on VRBL and FCA, the latter medium appears to allow the enumeration of more true fecal coliforms and has higher performance in certain ways (specificity, sensitivity, and negative and positive predictive values) than VRBL. Most colonies clearly identified on both media were E. coli and H. alvei, a non-fecal coliform. Therefore, the replacement of fecal coliform enumeration by E. coli enumeration to estimate food sanitary quality should be recommended. PMID:11916678

  18. The Soft Agar Colony Formation Assay

    PubMed Central

    Borowicz, Stanley; Van Scoyk, Michelle; Avasarala, Sreedevi; Karuppusamy Rathinam, Manoj Kumar; Tauler, Jordi; Bikkavilli, Rama Kamesh; Winn, Robert A.

    2014-01-01

    Anchorage-independent growth is the ability of transformed cells to grow independently of a solid surface, and is a hallmark of carcinogenesis. The soft agar colony formation assay is a well-established method for characterizing this capability in vitro and is considered to be one of the most stringent tests for malignant transformation in cells. This assay also allows for semi-quantitative evaluation of this capability in response to various treatment conditions. Here, we will demonstrate the soft agar colony formation assay using a murine lung carcinoma cell line, CMT167, to demonstrate the tumor suppressive effects of two members of the Wnt signaling pathway, Wnt7A and Frizzled-9 (Fzd-9). Concurrent overexpression of Wnt7a and Fzd-9 caused an inhibition of colony formation in CMT167 cells. This shows that expression of Wnt7a ligand and its Frizzled-9 receptor is sufficient to suppress tumor growth in a murine lung carcinoma model. PMID:25408172

  19. Effect of Soybean Casein Digest Agar Lot on Number of Bacillus stearothermophilus Spores Recovered †

    PubMed Central

    Pflug, I. J.; Smith, Geraldine M.; Christensen, Ronald

    1981-01-01

    In recent years it has become increasingly apparent that Bacillus stearothermophilus spores are affected by various environmental factors that influence the performance of the spores as biological indicators. One environmental factor is the recovery medium. The effect of different lots of commercial soybean casein digest agar on the number of colony-forming units per plate was examined in two series of experiments: (i) several lots of medium from two manufacturers were compared in single experiments, and (ii) paired media experiments with four lots of medium were carried out and yielded three-point survivor curves. The results demonstrate that commercial soybean casein digest agar is variable on a lot-to-lot basis. The variation was lowest when recovering unheated or minimally heated spores and increased greatly with the severity of heating. PMID:16345822

  20. Luminescent DNA- and agar-based membranes.

    PubMed

    Leones, R; Fernandes, M; Ferreira, R A S; Cesarino, I; Lima, J F; Carlos, L D; Bermudez, V de Zea; Magon, C J; Donoso, J P; Silva, M M; Pawlicka, A

    2014-09-01

    Luminescent materials containing europium ions are investigated for different optical applications. They can be obtained using bio-macromolecules, which are promising alternatives to synthetic polymers based on the decreasing oil resources. This paper describes studies of the DNA- and Agar-europium triflate luminescent membranes and its potential technological applications are expanded to electroluminescent devices. Polarized optical microscopy demonstrated that the samples are birefringent with submicrometer anisotropy. The X-ray diffraction analysis revealed predominantly amorphous nature of the samples and the atomic force microscopy images showed a roughness of the membranes of 409.0 and 136.1 nm for the samples of DNA10Eu and Agar1.11Eu, respectively. The electron paramagnetic resonance spectra of the DNA(n)Eu membranes with the principal lines at g ≈ 2.0 and g ≈ 4.8 confirmed uniform distribution of rare earth ions in a disordered matrix. Moreover, these strong and narrow resonance lines for the samples of DNA(n)Eu when compared to the Agar(n)Eu suggested a presence of paramagnetic radicals arising from the DNA matrix. The emission spectra suggested that the Eu3+ ions occupy a single local environment in both matrices and the excitation spectra monitored around the Eu emission lines pointed out that the Eu3+ ions in the Agar host were mainly excited via the broad band component rather than by direct intra-4f(6) excitation, whereas the opposite case occurred for the DNA-based sample. PMID:25924317

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

    NASA Technical Reports Server (NTRS)

    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.

  2. Improvement of modified charcoal-cefoperazone-deoxycholate agar by addition of potassium clavulanate for detecting Campylobacter spp. in chicken carcass rinse.

    PubMed

    Chon, Jung-Whan; Kim, Hyunsook; Kim, Hong-Seok; Seo, Kun-Ho

    2013-07-01

    The presence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) in raw poultry is one of the most common factors that interfere with the isolation of Campylobacter by cefoperazone-based selective agar. The performance of modified charcoal-cefoperazone-deoxycholate agar (mCCDA) was improved by addition of an ESBL inhibitor, potassium clavulanate (0.5 mg/L). The ability of the supplemented medium (C-mCCDA) to detect Campylobacter species from chicken carcass rinse was compared with that of normal mCCDA. The isolation rate using C-mCCDA was significantly (p<0.05) higher compared with that using mCCDA (C-mCCDA, 67 out of 120; mCCDA, 38 out of 120). Furthermore, the selectivity of the C-mCCDA as assessed by comparing the number of contaminated plates (C-mCCDA, 44 out of 120; mCCDA, 110 out of 120) and growth index (C-mCCDA, 1.76; mCCDA, 2.79) of competing flora was also better (p<0.05) than that of mCCDA.

  3. McKay agar enables routine quantification of the 'Streptococcus milleri' group in cystic fibrosis patients.

    PubMed

    Sibley, Christopher D; Grinwis, Margot E; Field, Tyler R; Parkins, Michael D; Norgaard, Jens C; Gregson, Daniel B; Rabin, Harvey R; Surette, Michael G

    2010-05-01

    The 'Streptococcus milleri' group (SMG) has recently been recognized as a contributor to bronchopulmonary disease in cystic fibrosis (CF). Routine detection and quantification is limited by current CF microbiology protocols. McKay agar was developed previously for the semi-selective isolation of this group. Here, McKay agar was validated against a panel of clinical SMG isolates, which revealed improved SMG recovery compared with Columbia blood agar. The effectiveness of this medium was evaluated by appending it to the standard CF sputum microbiology protocols in a clinical laboratory for a 6-month period. All unique colony types were isolated and identified by 16S rRNA gene sequencing. Whilst a wide variety of organisms were isolated, members of the SMG were the most prevalent bacteria cultured, and McKay agar allowed routine quantification of the SMG from 10(3) to >10(8) c.f.u. ml(-1) directly from sputum. All members of the SMG were detected [Streptococcus anginosus (40.7 %), Streptococcus intermedius (34.3 %) and Streptococcus constellatus (25 %)] with an overall prevalence rate of 40.6 % in our adult CF population. Without exception, samples where SMG isolates were cultured at 10(7) c.f.u. ml(-1) or greater were associated with pulmonary exacerbations. This study demonstrates that McKay agar can be used routinely to quantify the SMG from complex clinical samples.

  4. Evaluation of three decarboxylating agar media to detect histamine and tyramine-producing bacteria in ripened sausages.

    PubMed

    Roig-Sagués, A X; Hernàndez-Herrero, M M; López-Sabater, E I; Rodríguez-Jerez, J J; Mora-Ventura, M T

    1997-11-01

    Histidine- and tyrosine-decarboxylase activity of 175 strains of bacteria isolated from eight retail samples of Spanish ripened sausages was tested in three decarboxylating agars (Niven medium, Joosten and Northolt medium and modified decarboxylating agar of Maijala) and confirmed by an enzymic method (histamine) and thin-layer chromatography (tyramine). Enterobacteria and pseudomonads showed the highest percentage of positive responses to histamine and tyramine in the three decarboxylating agars, but only enterobacteria were subsequently confirmed as histamine-producing. Confirmed tyramine-producing strains were all identified as enterococci or lactic acid bacteria. The medium described by Joosten and Northolt was more sensitive and faster at detecting tyramine-producing microorganisms. However, all three media failed to detect one histamine-positive strain of lactic acid bacteria used as a control.

  5. Agar media that indicate acid production from sorbitol by oral microorganisms.

    PubMed

    Kalfas, S; Edwardsson, S

    1985-12-01

    Two varieties of agar medium (Trypticase [BBL Microbiology Systems]-serum-sorbitol-bromcresol purple agar [TSSB] and Trypticase-blood-sorbitol-CaCO3 agar [TBSCa]) indicating microbial acid production from sorbitol were tested. The media were devised for use in studies on the prevalence of sorbitol-fermenting human oral microorganisms incubated in an anaerobic or microaerophilic atmosphere containing 5 to 6% CO2. TSSB contains bromcresol purple as the pH indicator and NaHCO3 as the main buffering salt. TBSCa contains CaCO3 as both the buffering salt and the indicator of acid production. The growth yield of pure cultures of oral microorganisms on TBSCa was shown to equal that on blood agar incubated under similar conditions. TSSB inhibited the growth of several bacteria to various extents. The recovery of sorbitol-fermenting microorganisms from oral specimens was the greatest when the specimens were assayed with TBSCa. The poorer results obtained with TSSB were mainly due to the decoloration of the pH indicator in this medium and the presence of greater numbers of sorbitol false-positive colonies.

  6. Syneresis and delayed detachment in agar plates

    NASA Astrophysics Data System (ADS)

    Divoux, Thibaut; Mao, Bosi; Snabre, Patrick

    Biogels made of crosslinked polymers such as proteins or polysaccharides behave as porous soft solids and store large amount of solvent. These gels undergo spontaneous aging, called syneresis that consists in the shrinkage of the gel matrix and the progressive expulsion of the solvent. As a result, a biogel originally casted in a container often lose contact with the container sidewalls, and the detachment time is a priori difficult to anticipate since it may occur over variable time spans (from hours to days). Here we report on the syneresis phenomena in agar plates that consist in Petri dishes filled with a gel mainly composed of agar. Direct observations and speckle pattern correlation analysis allow us to rationalize the delayed detachment of the gel from the sidewall of the Petri dish. The detachment time $t^*$ is surprisingly not controlled by the mass loss as one would intuitively expect. Instead, $t^*$ is strongly correlated to the gel minimum thickness $e_{min}$ measured along the sidewall of the plate, and increases as a robust function of $e_{min}$ independently of the prior mass-loss history. Time-resolved correlation spectroscopy atypically applied to such weakly diffusive media gives access to the local thinning rate of the gel. This technique also allows us to detect the gel micro-displacements that are triggered by the water evaporation prior to the detachment, and even to anticipate the latter from a few hours. Our work provides observables to predict the detachment time of agar gels in dishes, and highlights the relevance of speckle pattern correlation analysis for the quantitative investigation of the syneresis dynamics in biopolymer gels.

  7. Syneresis and delayed detachment in agar plates.

    PubMed

    Divoux, Thibaut; Mao, Bosi; Snabre, Patrick

    2015-05-14

    Biogels made of crosslinked polymers such as proteins or polysaccharides behave as porous soft solids and store large amounts of solvent. These gels undergo spontaneous aging, called syneresis, which consists of the shrinkage of the gel matrix and the progressive expulsion of solvent. As a result, a biogel originally casted in a container often loses contact with the container sidewalls, and the detachment time is difficult to anticipate a priori, since it may occur over variable time spans (from hours to days). Here we report on syneresis phenomena in agar plates, which consist of Petri dishes filled with a gel mainly composed of agar. Direct observations and speckle pattern correlation analysis allow us to rationalize the delayed detachment of the gel from the sidewall of the Petri dish. The detachment time t* is surprisingly not controlled by the mass loss as one would intuitively expect. Instead, t* is strongly correlated to the gel minimum thickness emin measured along the sidewall of the plate, and increases as a robust function of emin, independently of the prior mass-loss history. Time-resolved correlation spectroscopy atypically applied to such weakly diffusive media gives access to the local thinning rate of the gel. This technique also allows us to detect the gel micro-displacements that are triggered by water evaporation prior to the detachment, and even to anticipate the latter from a few hours. Our work provides observables to predict the detachment time of agar gels in dishes, and highlights the relevance of speckle pattern correlation analysis for the quantitative investigation of the syneresis dynamics in biopolymer gels.

  8. Syneresis and delayed detachment in agar plates.

    PubMed

    Divoux, Thibaut; Mao, Bosi; Snabre, Patrick

    2015-05-14

    Biogels made of crosslinked polymers such as proteins or polysaccharides behave as porous soft solids and store large amounts of solvent. These gels undergo spontaneous aging, called syneresis, which consists of the shrinkage of the gel matrix and the progressive expulsion of solvent. As a result, a biogel originally casted in a container often loses contact with the container sidewalls, and the detachment time is difficult to anticipate a priori, since it may occur over variable time spans (from hours to days). Here we report on syneresis phenomena in agar plates, which consist of Petri dishes filled with a gel mainly composed of agar. Direct observations and speckle pattern correlation analysis allow us to rationalize the delayed detachment of the gel from the sidewall of the Petri dish. The detachment time t* is surprisingly not controlled by the mass loss as one would intuitively expect. Instead, t* is strongly correlated to the gel minimum thickness emin measured along the sidewall of the plate, and increases as a robust function of emin, independently of the prior mass-loss history. Time-resolved correlation spectroscopy atypically applied to such weakly diffusive media gives access to the local thinning rate of the gel. This technique also allows us to detect the gel micro-displacements that are triggered by water evaporation prior to the detachment, and even to anticipate the latter from a few hours. Our work provides observables to predict the detachment time of agar gels in dishes, and highlights the relevance of speckle pattern correlation analysis for the quantitative investigation of the syneresis dynamics in biopolymer gels. PMID:25812667

  9. Characteristic features and dye degrading capability of agar-agar gel immobilized manganese peroxidase.

    PubMed

    Bilal, Muhammad; Asgher, Muhammad; Shahid, Muhammad; Bhatti, Haq Nawaz

    2016-05-01

    Immobilization of enzymes has been regarded as an efficient approach to develop biocatalyst with improved activity and stability characteristics under reaction conditions. In the present study, purified manganese peroxidase (MnP) from Ganoderma lucidum IBL-05 was immobilized in agar-agar support using entrapment technique. Maximum immobilization yield was accomplished at 4.0% agar-agar gel. The immobilized MnP exhibited better resistance to changes in pH and temperature than the free enzyme, with optimal conditions being pH 6.0 and 50 °C. The kinetic parameters Km and Kcat/Km for free and entrapped MnP were calculated to be 65.6 mM and 6.99 M(-1) s(-1), and 82 mM and 8.15 M(-1) s(-1), respectively. Thermo-stability was significantly improved after immobilization. After 120 h, the insolubilized MnP retained its activity up to 71.9% and 60.3% at 30 °C and 40 °C, respectively. It showed activity until 10th cycle and retained 74.3% residual activity after 3th cycle. The effects of H2O2, ionic strength and potential inhibitors on activity of free and immobilized enzyme were investigated. Moreover, the decolorization of three structurally different dyes was monitored in order to assess the degrading capability of the entrapped MnP. The decolorization efficiencies for all the tested dyes were 78.6-84.7% after 12h. The studies concluded that the toxicity of dyes aqueous solutions was significantly reduced after treatment. The remarkable catalytic, thermo-stability and re-cycling features of the agar-agar immobilized MnP display a high potential for biotechnological applications. PMID:26854887

  10. Detection of encapsulation in Staphylococcus aureus by use of antiserum agar.

    PubMed Central

    West, T E; Apicella, M A

    1984-01-01

    We examined an antiserum agar method to study its reliability in screening Staphylococcus aureus strains for capsule production. The encapsulated S. aureus Smith diffuse strain was compared with its nonencapsulated variant, Smith compact, in CCY medium containing 0.5% NaCl and 5.0% Smith diffuse rabbit antiserum. A halo was visible surrounding colonies of the Smith diffuse strain but not the Smith compact strain. On this same medium, the protein A-producing Cowan I strain possessed a halo that was visible on photographs. Single high-salt medium is known to inhibit protein A production, halo formation by the strains was also compared in 7.5% NaCl medium. The halo surrounding the Cowan I strain was not present when the salt content of the medium was increased. In contrast, the halo surrounding the Smith diffuse strain persisted in the 7.5% NaCl medium. By use of this medium, the antiserum agar technique may be valuable for the identification of encapsulated staphylococci without appreciable interference from protein A. Images PMID:6490810

  11. A selective and differential medium for Vibrio harveyi.

    PubMed Central

    Harris, L; Owens, L; Smith, S

    1996-01-01

    A new medium, termed Vibrio harveyi agar, has been developed for the isolation and enumeration of V. harveyi. It is possible to differentiate V. harveyi colonies from the colonies of strains representing 15 other Vibrio species with this medium. This medium has been shown to inhibit the growth of two strains of marine Pseudomonas spp. and two strains of marine Flavobacterium spp. but to allow the growth of Photobacterium strains. Colonies displaying typical V. harveyi morphology were isolated from the larval rearing water of a commercial prawn hatchery with V. harveyi agar as a primary isolation medium and were positively identified, by conventional tests, as V. harveyi. This agar displays great potential as a primary isolation medium and offers significant advantages over thiosulfate-citrate-bile salts-sucrose agar as a medium for differentiating V. harveyi from other marine and estuarine Vibrio species. PMID:8795252

  12. Biological treatment of textile dyes by agar-agar immobilized consortium in a packed bed reactor.

    PubMed

    Patel, Yogesh; Gupte, Akshaya

    2015-03-01

    The decolorization of Acid Maroon V was investigated using bacterial consortium EDPA containing Enterobacter dissolvens AGYP1 and Pseudomonas aeruginosa AGYP2 immobilized in different entrapment matrices. The consortium displayed 96% removal of dye (100 mg/l) within 6 h when immobilized in agar-agar. Under optimum concentrations of agar-agar (3.0% w/v) and cell biomass (0.9 g% w/v), the consortium displayed decolorization for 18 successive batches of Acid Maroon V and also decolorized 14 other different textile dyes. A packed bed reactor under batch mode showed 89% decolorization of dye after 56 repetitive cycles. Under continuous flow mode, maximum color removal was achieved with bed length of 36 cm, hydraulic retention time of 2.66 h, and dye concentration of 100 mg/l. Additionally, the reactor decolorized relatively higher concentrations (100-2000 mg/l) of dye. The synthetic dye wastewater containing five textile dyes was decolorized 92% with 62% COD reduction using an immobilized consortium.

  13. Screening fungicides for use in fish culture: Evaluation of the agar plug transfer, cellophane transfer, and agar dilution methods

    USGS Publications Warehouse

    Bailey, Tom A.

    1983-01-01

    The reliability, reproducibility, and usefulness of three screening methods -- the cellophane transfer, the agar plug transfer, and the agar dilution -- to screen aquatic fungicides were evaluated. Achlya flagellata and Saprolegnia hypogyna were exposed to 1, 10, and 100 mg/L of malachite green to test each method. The cellophane transfer and agar plug transfer techniques had similar reliability and reproducibility in rating fungicidal activity, and were both superior to the agar dilution technique. The agar plug transfer and agar dilution techniques adequately projected in vivo activity of malachite green, but the cellophane transfer technique overestimated its activity. Overall, the agar plug transfer technique most accurately rated the activity of malachite green and was the easiest test to perform. It therefore appears to be the method of choice for testing aquatic fungicides.

  14. Recovery of spores of Clostridium botulinum in yeast extract agar and pork infusion agar after heat treatment.

    PubMed

    Odlaug, T E; Pflug, I J

    1977-10-01

    Yeast extract agar, pork infusion agar, and modifications of these media were used to recover heated Clostridium botulinum spores. The D- and z-values were determined. Two type A strains and one type B strain of C. botulinum were studied. In all cases the D-values were largest when the spores were recovered in yeast extract agar, compared to the D-values for spores recovered in pork infusion agar. The z-values for strains 62A and A16037 were largest when the spores were recovered in pork infusion agar. The addition of sodium bicarbonate and sodium thioglycolate to pork infusion agar resulted in D-values for C. botulinum 62A spores similar to those for the same spores recovered in yeast extract agar. The results suggest that sodium bicarbonate and sodium thioglycolate should be added to recovery media for heated C. botulinum spores to obtain maximum plate counts. PMID:335970

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

    PubMed

    Cold, Emma R; Freyria, Nastasia J; Martínez Martínez, Joaquín; Fernández Robledo, José A

    2016-01-01

    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.

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

    PubMed Central

    Cold, Emma R.; Freyria, Nastasia J.; Martínez Martínez, Joaquín; Fernández Robledo, José A.

    2016-01-01

    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. PMID:27149378

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

    PubMed

    Cold, Emma R; Freyria, Nastasia J; Martínez Martínez, Joaquín; Fernández Robledo, José A

    2016-01-01

    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. PMID:27149378

  18. Effect of impact stress on microbial recovery on an agar surface.

    PubMed Central

    Stewart, S L; Grinshpun, S A; Willeke, K; Terzieva, S; Ulevicius, V; Donnelly, J

    1995-01-01

    Microbial stress due to the impaction of microorganisms onto an agar collection surface was studied experimentally. The relative recovery rates of aerosolized Pseudomonas fluorescens and Micrococcus luteus were determined as a function of the impaction velocity by using a moving agar slide impactor operating over a flow rate range from 3.8 to 40 liters/min yielding impaction velocities from 24 to 250 m/s. As a reference, the sixth stage of the Andersen Six-Stage Viable Particle Sizing Sampler was used at its operating flow rate of 28.3 liters/min (24 m/s). At a collection efficiency of close to 100% for the agar slide impactor, an increase in sampling flow rate and, therefore, in impaction velocity produced a significant decline in the percentage of microorganisms recovered. Conversely, when the collection efficiency was less than 100%, greater recovery and lower injury rates occurred. The highest relative rate of recovery (approximately 51% for P. fluorescens and approximately 62% for M. luteus) was obtained on the complete (Trypticase soy agar) medium at 40 and 24 m/s (6.4 and 3.8 liters/min), respectively. M. luteus demonstrated less damage than P. fluorescens, suggesting the hardy nature of the gram-positive strain versus that of the gram-negative microorganism. Comparison of results from the agar slide and Andersen impactors at the same sampling velocity showed that recovery and injury due to collection depends not only on the magnitude of the impaction velocity but also on the degree to which the microorganisms may be embedded in the collection medium.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7747946

  19. Isolation of Shiga toxin-producing Escherichia coli serogroups O26, O45, O103, O111, O121, and O145 from ground beef using modified rainbow agar and post-immunomagnetic separation acid treatment.

    PubMed

    Tillman, Glenn E; Wasilenko, Jamie L; Simmons, Mustafa; Lauze, Todd A; Minicozzi, Joseph; Oakley, Brian B; Narang, Neelam; Fratamico, Pina; Cray, Ailliam C

    2012-09-01

    It is estimated that at least 70% of human illnesses due to non-O157 Shiga toxin-producing Escherichia coli (STEC) in the United States are caused by strains from the top six serogroups (O26, O45, O103, O111, O121, and O145). Procedures for isolating STEC from food products often use plating media that include antimicrobial supplements at concentrations that inhibit background microflora growth but can also inhibit target STEC growth. In this study, an agar medium with lower supplement concentrations, modified Rainbow agar (mRBA), was evaluated for recovery of STEC serogroups O26, O45, O103, O111, O121, and O145 from ground beef enrichments. A post-immunomagnetic separation (IMS) acid treatment step was additionally used to reduce background microflora and increase recovery of target STEC strains. Ground beef samples (325 g) were artificially contaminated with STEC and confounding organisms and enriched for 15 h. Recovery of the target STEC was attempted on the enrichments using IMS and plating onto mRBA and Rainbow agar (RBA). Additionally, acid treatment was performed on the post-IMS eluate followed by plating onto mRBA. Using the combination of mRBA and acid treatment, target STEC were isolated from 103 (85.8%) of 120 of the low-inoculated samples (1 to 5 CFU/325-g sample) compared with 68 (56.7%) of 120 using no acid treatment and plating onto RBA with higher levels of novobiocin and potassium tellurite. The combination of acid treatment and mRBA provides a significant improvement over the use of RBA for isolation of STEC serogroups O26, O45, O103, O111, O121, and O145 from raw ground beef.

  20. Evaluation and interlaboratory validation of a selective agar for phosphatidylinositol-specific phospholipase C activity using a chromogenic substrate to detect Listeria monocytogenes from foods.

    PubMed

    Jinneman, Karen C; Hunt, Jan M; Eklund, Cheryl A; Wernberg, Jane S; Sado, Patricia N; Johnson, Janelle M; Richter, Richelle S; Torres, Selene T; Ayotte, Eugene; Eliasberg, Stacey J; Istafanos, Phillip; Bass, Deborah; Kexel-Calabresa, Nancy; Lin, Wen; Barton, Curtis N

    2003-03-01

    Phosphatidylinositol-specific phospholipase C (PI-PLC) activity is a potential virulence factor and is exhibited only by the Listeria species Listeria monocytogenes and Listeria ivanovii. A chromogenic substrate for the direct detection of PI-PLC activity is available in a new medium (BCM L. monocytogenes plating agar). The use of a chromogenic substrate offers a mechanism with which to directly screen for L. monocytogenes and L. ivanovii other than the esculin used in Oxford (OXF) and Palcam (PAL) agars, which screen for all Listeria species. The specificity levels of BCM plating agar and of BCM confirmation and rhamnose agars were evaluated with 107 Listeria and 10 Bacillus species isolates. In addition, BCM L. monocytogenes plating agar was compared with standard Listeria selective agars (OXF and PAL agars) with regard to the recovery of L. monocytogenes from 2,000 food and environmental samples obtained from eight participating laboratories. A Listeria species was isolated from at least one of the agars in 209 analyses, and L. monocytogenes was isolated in 135 of these analyses. In 27 of the analyses in which L. monocytogenes was isolated, one or more of the selective differential agars used failed to isolate L. monocytogenes, and therefore the results of these analyses were discrepant. Relative to a reference method involving the use of all three agars (OXF, PAL, and BCM agars), the OXF-BCM, PAL-BCM, and OXF-PAL combinations had sensitivities of 99.3, 99.2, and 90.2%, respectively. In statistical analyses of the different combinations of agars, the OXF-BCM and BCM-PAL combinations were found to be superior to the OXF-PAL combination for the detection of L. monocytogenes.

  1. CHROMagar Yersinia, a New Chromogenic Agar for Screening of Potentially Pathogenic Yersinia enterocolitica Isolates in Stools

    PubMed Central

    Renaud, Nicolas; Lecci, Laetitia; Courcol, René J.; Simonet, Michel

    2013-01-01

    CHROMagar Yersinia (CAY) is a new chromogenic medium for the presumptive detection of virulent Yersinia enterocolitica in stools. Based on a comparative analysis of 1,494 consecutive stools from hospitalized patients, CAY was found to be just as sensitive as the reference medium (cefsulodin-irgasan-novobiocin agar) but was significantly more specific and had a very low false-positive rate. CAY reduces the workload (and thus costs) for stool analysis and can therefore be recommended for routine laboratory use. PMID:23363840

  2. Alternative use for spectra MRSA chromogenic agar in detection of methicillin-resistant Staphylococcus aureus from positive blood cultures.

    PubMed

    Peterson, Jess F; Dionisio, Alexander A; Riebe, Katherine M; Hall, Gerri S; Wilson, Deborah A; Whittier, Susan; Dipersio, Joseph R; Ledeboer, Nathan A

    2010-06-01

    Spectra MRSA agar (Remel, Lenexa, KS), a novel chromogenic medium originally developed to detect methicillin-resistant Staphylococcus aureus (MRSA) from nasal swabs, was evaluated in this multicenter study for the detection of MRSA from positive blood cultures exhibiting Gram-positive cocci upon initial Gram staining.

  3. Impaction onto a Glass Slide or Agar versus Impingement into a Liquid for the Collection and Recovery of Airborne Microorganisms

    PubMed Central

    Juozaitis, Arvydas; Willeke, Klaus; Grinshpun, Sergey A.; Donnelly, Jean

    1994-01-01

    To study impaction versus impingement for the collection and recovery of viable airborne microorganisms, three new bioaerosol samplers have been designed and built. They differ from each other by the medium onto which the bioaerosol particles are collected (glass, agar, and liquid) but have the same inlet and collection geometries and the same sampling flow rate. The bioaerosol concentrations recorded by three different collection techniques have been compared with each other: impaction onto a glass slide, impaction onto an agar medium, and impingement into a liquid. It was found that the particle collection efficiency of agar slide impaction depends on the concentration of agar in the collection medium and on the sampling time, when samples are collected on a nonmoving agar slide. Impingement into a liquid showed anomalous behavior with respect to the sampling flow rate. Optimal sampling conditions in which all three new samplers exhibit the same overall sampling efficiency for nonbiological particles have been established. Inlet and collection efficiencies of about 100% have been achieved for all three devices at a sampling flow rate of 10 liters/min. The new agar slide impactor and the new impinger were then used to study the biological factors affecting the overall sampling efficiency. Laboratory experiments on the total recovery of a typical environmental microorganism, Pseudomonas fluorescens ATCC 13525, showed that both sampling methods, impaction and impingement, provided essentially the same total recovery when relatively nonstressed microorganisms were sampled under optimal sampling conditions. Comparison tests of the newly developed bioaerosol samplers with those commercially available showed that the incorporation of our research findings into the design of the new samplers yields better performance data than data from currently available samplers. PMID:16349217

  4. Efficacy of the thin agar layer method for the recovery of stressed Cronobacter spp. (Enterobacter sakazakii).

    PubMed

    Osaili, Tareq M; Al-Nabulsi, Anas A; Shaker, Reyad R; Al-Holy, Murad M; Al-Haddaq, Mohammed S; Olaimat, Amin N; Ayyash, Mutamed M; Al Ta'ani, Mahmoud K; Forsythe, Stephen J

    2010-10-01

    Cronobacter spp. (Enterobacter sakazakii) are emerging opportunistic pathogens for all age groups, and are of particular concern when it comes to infants. Prior to contaminating food, the organism may be exposed to a variety of stresses, leading to a generation of sublethally injured cells that may not be detected by selective media unless a protracted recovery period is included in the isolation procedure. This study evaluated the efficacy of the thin agar layer (TAL) method for the recovery of Cronobacter cells that had been exposed to various stress conditions. Five strains of C. sakazakii and C. muytjensii were exposed to starvation, heat, cold, acid, alkaline, chlorine, or ethanol, with or without further exposure to desiccation stress. The recovery of the stressed cells was determined on tryptone soy agar (TSA; nonselective control medium), violet red bile glucose agar (VRBGA; selective agar), Druggan-Forsythe-Iversen (DFI; selective agar), and TAL media (viz., VRBGA overlaid with TSA, and DFI overlaid with TSA). Regardless of stress type, there were no significant differences among the recoveries of stressed desiccated Cronobacter spp. cultures on TSA, DFI+TSA, and VRBGA+TSA, but there was significantly less recovery on VRBGA. The recovery of prestressed desiccated Cronobacter spp. on DFI+TSA was similar to that on TSA, whereas the recovery on VRBGA+TSA was lower. DFI+TSA performed better than VRBGA+TSA did in differentiating Cronobacter spp. within mixed bacterial cultures. The results of this study suggest the use of the TAL method DFI+TSA as an improved method for the direct recovery of stressed Cronobacter spp.

  5. Isolation and characterization of agar-digesting Vibrio species from the rotten thallus of Gracilariopsis heteroclada Zhang et Xia.

    PubMed

    Martinez, Joval N; Padilla, Philip Ian P

    2016-08-01

    Gracilariopsis heteroclada Zhang et Xia (Gracilariaceae, Rhodophyta) is one of the most studied marine seaweeds due to its economic importance. This has been cultivated extensively on commercial scale in the Philippines and other Asian countries. However, sustainable production of G. heteroclada in the Philippines could not be maximized due to the occurrence of rotten thallus disease. Thus, isolation and characterization of agar-digesting bacteria from the rotten thalli of G. heteroclada was conducted. A total of seven representative bacterial isolates were randomly selected based on their ability to digest agar as evidenced by the formation of depressions around the bacterial colonies on nutrient agar plates supplemented with 1.5% NaCl and liquefaction of agar. Gram-staining and biochemical characterization revealed that isolates tested were gram-negative rods and taxonomically identified as Vibrio parahaemolyticus (86-99.5%) and Vibrio alginolyticus (94.2-97.7%), respectively. It is yet to be confirmed whether these agar-digesting vibrios are involved in the induction and development of rotten thallus disease in G. heteroclada in concomitance with other opportunistic bacterial pathogens coupled with adverse environmental conditions. PMID:27285614

  6. Supplementation of medium with diammonium hydrogen phosphate enhanced the D-lactate dehydrogenase levels leading to increased D-lactic acid productivity.

    PubMed

    Singhvi, Mamata; Jadhav, Akanksha; Gokhale, Digambar

    2013-10-01

    The production of D-lactic acid by Lactobacillus lactis RM2-24 was investigated using modified media to increase the efficiency of the fermentation process. The results indicated that the addition of 5 g/l peptone and 1 g/l (NH4)2HPO4 enhanced D-lactic acid production by 32%, as compared to that obtained from non supplemented media, with a productivity of 3.0 g/l/h. Lactate dehydrogenase (LDH) expression profile in these different media was studied which resulted in appearance of additional LDH isoform produced by cells when they were grown in HSYE supplemented with (NH4)2HPO4. The additional LDH appears to be L-LDH contributing to production of L-lactic acid in the fermented broth. This is totally new information in the lactic acid fermentation and could be very useful to industries engaged in D-lactic acid production. PMID:23932744

  7. Supplementation of medium with diammonium hydrogen phosphate enhanced the D-lactate dehydrogenase levels leading to increased D-lactic acid productivity.

    PubMed

    Singhvi, Mamata; Jadhav, Akanksha; Gokhale, Digambar

    2013-10-01

    The production of D-lactic acid by Lactobacillus lactis RM2-24 was investigated using modified media to increase the efficiency of the fermentation process. The results indicated that the addition of 5 g/l peptone and 1 g/l (NH4)2HPO4 enhanced D-lactic acid production by 32%, as compared to that obtained from non supplemented media, with a productivity of 3.0 g/l/h. Lactate dehydrogenase (LDH) expression profile in these different media was studied which resulted in appearance of additional LDH isoform produced by cells when they were grown in HSYE supplemented with (NH4)2HPO4. The additional LDH appears to be L-LDH contributing to production of L-lactic acid in the fermented broth. This is totally new information in the lactic acid fermentation and could be very useful to industries engaged in D-lactic acid production.

  8. De novo fatty acid biosynthesis and elongation in very long-chain acyl-CoA dehydrogenase-deficient mice supplemented with odd or even medium-chain fatty acids.

    PubMed

    Tucci, Sara; Behringer, Sidney; Spiekerkoetter, Ute

    2015-11-01

    An even medium-chain triglyceride (MCT)-based diet is the mainstay of treatment in very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency (VLCADD). Previous studies with magnetic resonance spectroscopy have shown an impact of MCT on the average fatty acid chain length in abdominal fat. We therefore assume that medium-chain fatty acids (MCFAs) are elongated and accumulate in tissue as long-chain fatty acids. In this study, we explored the hepatic effects of long-term supplementation with MCT or triheptanoin, an odd-chain C7-based triglyceride, in wild-type and VLCAD-deficient (VLCAD(-/-) ) mice after 1 year of supplementation as compared with a control diet. The de novo biosynthesis and elongation of fatty acids, and peroxisomal β-oxidation, were quantified by RT-PCR. This was followed by a comprehensive analysis of hepatic and cardiac fatty acid profiles by GC-MS. Long-term application of even and odd MCFAs strongly induced de novo biosynthesis and elongation of fatty acids in both wild-type and VLCAD(-/-) mice, leading to an alteration of the hepatic fatty acid profiles. We detected de novo-synthesized and elongated fatty acids, such as heptadecenoic acid (C17:1n9), eicosanoic acid (C20:1n9), erucic acid (C22:1n9), and mead acid (C20:3n9), that were otherwise completely absent in mice under control conditions. In parallel, the content of monounsaturated fatty acids was massively increased. Furthermore, we observed strong upregulation of peroxisomal β-oxidation in VLCAD(-/-) mice, especially when they were fed an MCT diet. Our data raise the question of whether long-term MCFA supplementation represents the most efficient treatment in the long term. Studies on the hepatic toxicity of triheptanoin are still ongoing.

  9. De novo fatty acid biosynthesis and elongation in very long-chain acyl-CoA dehydrogenase-deficient mice supplemented with odd or even medium-chain fatty acids.

    PubMed

    Tucci, Sara; Behringer, Sidney; Spiekerkoetter, Ute

    2015-11-01

    An even medium-chain triglyceride (MCT)-based diet is the mainstay of treatment in very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency (VLCADD). Previous studies with magnetic resonance spectroscopy have shown an impact of MCT on the average fatty acid chain length in abdominal fat. We therefore assume that medium-chain fatty acids (MCFAs) are elongated and accumulate in tissue as long-chain fatty acids. In this study, we explored the hepatic effects of long-term supplementation with MCT or triheptanoin, an odd-chain C7-based triglyceride, in wild-type and VLCAD-deficient (VLCAD(-/-) ) mice after 1 year of supplementation as compared with a control diet. The de novo biosynthesis and elongation of fatty acids, and peroxisomal β-oxidation, were quantified by RT-PCR. This was followed by a comprehensive analysis of hepatic and cardiac fatty acid profiles by GC-MS. Long-term application of even and odd MCFAs strongly induced de novo biosynthesis and elongation of fatty acids in both wild-type and VLCAD(-/-) mice, leading to an alteration of the hepatic fatty acid profiles. We detected de novo-synthesized and elongated fatty acids, such as heptadecenoic acid (C17:1n9), eicosanoic acid (C20:1n9), erucic acid (C22:1n9), and mead acid (C20:3n9), that were otherwise completely absent in mice under control conditions. In parallel, the content of monounsaturated fatty acids was massively increased. Furthermore, we observed strong upregulation of peroxisomal β-oxidation in VLCAD(-/-) mice, especially when they were fed an MCT diet. Our data raise the question of whether long-term MCFA supplementation represents the most efficient treatment in the long term. Studies on the hepatic toxicity of triheptanoin are still ongoing. PMID:26284828

  10. Qualitative and quantitative agar invasion test based on bacterial colony/biofilm.

    PubMed

    Corcuera, María Teresa; Gómez-Aguado, Fernando; Gómez-Lus, María Luisa; Ramos, Carmen; de la Parte, María Antonia; Alonso, María José; Prieto, José

    2013-09-01

    Invasion of the culture medium is a feature frequently studied in yeasts, in which it has been related to a greater virulence, but it is practically unknown in bacteria. Recently, it has been demonstrated that several clinically relevant bacterial species were also able of invading agar media, so it was necessary to design a microbiological assay to study the expression of this character in bacteria. Accordingly, a bacterial agar invasion test based on colony/biofilm development was designed, which allows qualitative and quantitative characterization of bacterial growth into the agar culture medium. Once the culture conditions were optimized, the test was applied to 90 strains from nine bacterial species, validating its usefulness for differentiating invasive strains (positive) from those non invasive (negative). The test also allows sorting invasive strains according to agar invasion intensity (low, moderate, high) and topographic invasion pattern (peripheral, homogeneous, mixed). Moreover, an image analysis routine to quantify the invasion was developed. Implemented method enables direct measuring of two invasion parameters (invasion area and number of invasion dots), automated calculation of three relative variables (invasion relative area, invasion dots relative density, and invasion dot average area), and the establishment of strain specific frequency histograms. This new methodology is simple, fast, reproducible, objective, inexpensive and can be used to study a great number of specimens simultaneously, all of which make it suitable for incorporation to the routine of any microbiology laboratory. It could also be a useful tool for additional studies related to clinical aspects of bacterial isolates such as virulence and antimicrobial response.

  11. [Evaluation of the ChromID ESBL agar for the detection of ESBL-positive Enterobacteriaceae and vancomycin-resistant enterococcus isolates from urine cultures].

    PubMed

    Alışkan, Hikmet Eda; Colakoğlu, Sule; Turunç, Tuba; Demiroğlu, Yusuf Ziya

    2012-01-01

    Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae strains are frequent causative agents both in community-acquired infections and in nosocomial infections. The newly developed ChromID ESBL agar (bioMerieux, Marcy I'Etoile, France) is a chromogenic medium that helps rapid identification of ESBL-positive Enterobacteriaceae species from the clinical samples. The aim of this study was to evaluate the performance of ChromID ESBL agar in the rapid identification of ESBL-positive pathogens from the urine samples of the patients with urinary tract infections. A total of 672 urine samples (437 outpatients, 235 inpatients) were included in the study. All of the samples were inoculated simultaneously to 5% sheep blood agar, McConkey agar and ChromID ESBL agar media, and evaluated after incubation at 37°C for 18-24 hours. Gram-negative pathogens were tested for ESBL both by the standard combined double-disk diffusion (CDD) method using ceftazidime and cefotaxime disks and by doubledisk synergy (DDS) test. Among 672 urine cultures, 199 yielded microbial growth in routine media (sheep blood agar and/or McConkey agar), whereas 57 yielded bacterial growth in ChromID ESBL agar. When CDD method was accepted as the reference method according to Clinical and Laboratory Standards Institute (CLSI) recommendations, the sensitivity, specificity, positive and negative predictive values for ChromID ESBL agar for the detection of ESBL-positive bacteria in urinary tract infections were estimated as 97%, 92.9%, 89.1%, and 98.1%, respectively. Additionally, we also discovered that Chrom ID ESBL agar could detect vancomycin-resistant enterococci (VRE) as well as ESBL-positive bacteria, in our study. In order to investigate this observation we inoculated a total of 203 stock strains of Enterococcus spp. (118 vancomycin-sensitive, 85 vancomycin-resistant) to this medium. None of the vancomycinsensitive Enterococcus spp. did grow in ChromID ESBL medium, while 83 of the 85

  12. [A selective nutrient medium for isolating clinical strains of Escherichia coli O157:H7].

    PubMed

    Sultanov, Z Z; Stepanova, E D; Kakulina, E A

    2000-01-01

    A dried selective culture medium, electrolyte-deficient sorbitol agar (EDS agar), for the isolation and preliminary identification of E. coli O157:H7 from clinical material has been developed. The medium is not inferior in its quality to analogous foreign media and requires no scarce ingredients for its manufacture.

  13. Performance of chromID Clostridium difficile agar compared with BBL C. difficile selective agar for detection of C. difficile in stool specimens.

    PubMed

    Han, Sang Bong; Chang, Jiyoung; Shin, Sang Hyun; Park, Kang Gyun; Lee, Gun Dong; Park, Yong Gyu; Park, Yeon-Joon

    2014-09-01

    We evaluated the performance of a new chromogenic medium for detection of Clostridium difficile, chromID C. difficile agar (CDIF; bioMérieux, France), by comparison with BBL C. difficile Selective Agar (CDSA; Becton Dickinson and Company, USA). After heat pre-treatment (80℃, 5 min), 185 diarrheal stool samples were inoculated onto the two media types and incubated anaerobically for 24 hr and 48 hr for CDIF and for 48 hr and 72 hr for CDSA. All typical colonies on each medium were examined by Gram staining, and the gram-positive rods confirmed to contain the tpi gene by PCR were identified as C. difficile. C. difficile was recovered from 36 samples by using a combination of the two media. The sensitivity with CDIF 48 hr was highest (100%) and was significantly higher than that with CDIF 24 hr (58.3%; P<0.001), because samples with a low burden of C. difficile tended to require prolonged incubation up to 48 hr (P<0.001). The specificity of CDIF 24 hr and CDIF 48 hr (99.3% and 90.6%, respectively) was significantly higher than that of CDSA 48 hr and CDSA 72 hr (72.5% and 67.1%, respectively; P<0.001). CDIF was effective for detecting C. difficile in heat-pretreated stool specimens, thus reducing unnecessary testing for toxin production in non-C. difficile isolates and turnaround time.

  14. In vitro growth and organogenesis of Prosopis farcta plantlets (Fabaceae, Mimosoideae) in culture medium supplemented with various concentrations of Ca++ and Na+.

    PubMed

    Stambouli, S; Bouzid, S; Dutuit, P; Harzallah-Skhiri, Fethia

    2012-03-01

    The objective of this study was to vary the mineral composition of the culture medium of Prosopis farcta seedlings per addition of Na+ and Ca++ ions with the aim to identify the culture media which support the growth and/or the expression of the in vitro plant organogenesis. The Na+ and Ca++ ions were added in the culture medium in various concentrations by taking the Gamborg medium, in which macroelements were diluted 10 times, as the basic one. After two months of culture, parameters relating to the vegetative development of plant seedlings and to the various expressions of organogenesis were measured. Weak concentrations in sodium and calcium ions as well as a weak concentration in Ca++ (0.1 mM) with 50 mM in Na+ support the best vegetative development of the plantlets. The most important percentage of plant seedlings presenting a bud initiation was obtained on a medium containing 0.1 mM of Na+ and 50 mM of Ca++. Our study defined several media likely to support in vitro development of Prosopis farcta plantlets allowing the selection of salt tolerant plants or cellular lines. Some other media were chosen for improving micropropagation of the species without adding growth substances.

  15. Inhibition of Aspergillus flavus on agar media and brown rice cereal bars using cold atmospheric plasma treatment.

    PubMed

    Suhem, Kitiya; Matan, Narumol; Nisoa, Mudtorlep; Matan, Nirundorn

    2013-02-01

    This study aimed to optimize the operating parameters of cold atmospheric plasma treatment to inhibit the growth of Aspergillus flavus on agar media and brown rice cereal bars. The effects of argon plasma jet treatment on the growth of A. flavus on malt extract agar (MEA) at powers of 20 W and 40 W with exposure times at 5, 15 and 25 min were studied using response surface methodology (RSM) with a central composite face-centered (CCF) design. Multiple regression analysis indicated that plasma treatment at 40 W for 25 min is most effective for inhibiting growth of A. flavus on the agar medium. On brown rice cereal bars, plasma powered at 40 W for 20 min was capable of giving protection against A. flavus growth for up to 20 days under storage conditions of 25°C and 100% RH. These results demonstrated the potential of cold atmospheric plasma jet treatment to control mold growth on various food products.

  16. Differentiation of Candida dubliniensis from Candida albicans on rosemary extract agar and oregano extract agar.

    PubMed

    de Loreto, Erico Silva; Pozzatti, Patrícia; Alves Scheid, Liliane; Santurio, Deise; Morais Santurio, Janio; Alves, Sydney Hartz

    2008-01-01

    Candida dubliniensis is a recently described pathogenic species which shares many phenotypic features with Candida albicans and therefore, may be misidentified in microbiological laboratories. Because molecular methods can be onerous and unfeasible in routine mycological laboratories with restricted budgets such as those in developing countries, phenotypic techniques have been encouraged in the development of differential media for the presumptive identification of these species. We examined the colony morphology and chlamydospore production of 30 C. dubliniensis isolates and 100 C. albicans isolates on two new proposed media: rosemary (Rosmarinus officinalis) extract agar (REA) and oregano (Origanum vulgare) extract agar (OEA). These substrates are traditionally used as spices and medicinal herbs. In both of these media, all C. dubliniensis isolates (100%) showed rough colonies with peripheral hyphal fringes and abundant chlamydospores after 24 to 48 hr of incubation at 25 degrees C. In contrast, under the same conditions, all isolates of C. albicans (100%) showed smooth colonies without hyphal fringes or chlamydospores. In conclusion, REA and OEA offer a simple, rapid, and inexpensive screening media for the differentiation of C. albicans and C. dubliniensis.

  17. Direct Protocol for Ambient Mass Spectrometry Imaging on Agar Culture.

    PubMed

    Angolini, Célio Fernando F; Vendramini, Pedro Henrique; Araújo, Francisca D S; Araújo, Welington L; Augusti, Rodinei; Eberlin, Marcos N; de Oliveira, Luciana Gonzaga

    2015-07-01

    Herein we describe a new protocol that allows direct mass spectrometry imaging (IMS) of agar cultures. A simple sample dehydration leads to a thin solid agar, which enables the direct use of spray-based ambient mass spectrometry techniques. To demonstrate its applicability, metal scavengers siderophores were imaged directly from agar culture of S. wadayamensis, and well resolved and intense images were obtained using both desorption electrospray ionization (DESI) and easy ambient sonic-spray ionization (EASI) with well-defined selective spatial distributions for the free and the metal-bound molecules, providing clues for their roles in cellular metabolism.

  18. Automated counting of bacterial colony forming units on agar plates.

    PubMed

    Brugger, Silvio D; Baumberger, Christian; Jost, Marcel; Jenni, Werner; Brugger, Urs; Mühlemann, Kathrin

    2012-01-01

    Manual counting of bacterial colony forming units (CFUs) on agar plates is laborious and error-prone. We therefore implemented a colony counting system with a novel segmentation algorithm to discriminate bacterial colonies from blood and other agar plates.A colony counter hardware was designed and a novel segmentation algorithm was written in MATLAB. In brief, pre-processing with Top-Hat-filtering to obtain a uniform background was followed by the segmentation step, during which the colony images were extracted from the blood agar and individual colonies were separated. A Bayes classifier was then applied to count the final number of bacterial colonies as some of the colonies could still be concatenated to form larger groups. To assess accuracy and performance of the colony counter, we tested automated colony counting of different agar plates with known CFU numbers of S. pneumoniae, P. aeruginosa and M. catarrhalis and showed excellent performance.

  19. Development of a selective culture medium for Fusarium moniliforme.

    PubMed

    Castellá, G; Bragulat, M R; Rubiales, M V; Cabañes, F J

    1997-12-01

    Nash and Snyder medium and malachite green agar 2.5 ppm medium, a new selective culture medium designed in our laboratory, were challenged with pure cultures of Fusarium moniliforme strains and two different mixed-conidium suspensions, which included rapidly spreading fungi, for their utility in the isolation and enumeration of F. moniliforme. From the results of this comparative study, malachite green agar 2.5 ppm allowed only the selective growth of F. moniliforme whereas Nash and Snyder medium allowed both the growth of F. moniliforme and other species not belonging to Fusarium spp. The enumeration of F. moniliforme propagules was similar in both culture media.

  20. The Resazurin-Agar Method - a Quick Test to Determine Water Quality

    NASA Astrophysics Data System (ADS)

    Huckfeldt, J.; Westphal, B.; Claußen, L.

    2015-12-01

    Rezasurin has been used as a smart tracer in stream ecosystems to indicate metabolic activity, specifically aerobic respiration by heterotrophic bacteria. Resazurin is a blue compound which is irreversibly reduced to the pink resorufin in the presence of aerobic bacteria. The degree and speed of colour change from blue to pink is a measure of the degree of oxygen consumption and thus an indirect indication of the concentration of aerobic bacteria in a given medium. A high concentration of bacteria in water indicates a bad water quality. In our work a method was developed using resazurin agar plates to find a quick and easy way for testing water quality and comparing concentrations of bacteria in freshwater and seawater samples. The theory was to concentrate bacteria from a defined volume of water sample onto polycarbonate filters (0.2 μm), which are then placed onto the resazurin agar plate. The presence of aerobic bacteria on the filter will reduce the resazurin in the agar and the compound changes its colour. First tests conducted with different dilutions of a pure culture of yoghurt bacteria showed promising results and confirmed the feasibility of the method. In a further assay, we used water samples from different water layers and different temperatures and were also able to observe differences in the concentration of bacteria, depending on these different environmental conditions.The assay was also successfully used with seawater samples, collected from 2 different stations at 3 different depths in the Baltic Sea (salinity=15). The discolouration of the plates showed good correlation with the oxygen concentrations in the water. The resazurin-agar plate method is economical and fast. Several samples could be investigated at the same time without sacrificing the reliability of the results. Thus it is a good pre-screening test for a quantitative evaluation of bacteria in a water sample.

  1. Agar/collagen membrane as skin dressing for wounds.

    PubMed

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

    2008-12-01

    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 degrees 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&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.

  2. Evaluation of a new chromogenic medium for direct enumeration of Campylobacter in poultry meat samples.

    PubMed

    Seliwiorstow, Tomasz; Baré, Julie; Verhaegen, Bavo; Uyttendaele, Mieke; de Zutter, Lieven

    2014-12-01

    The present study was conducted to compare Campylobacter counts obtained by three selective media: modified charcoal cefoperazonedeoxycholate agar (mCCDA), Campy Food agar (CFA), and a novel agar RAPID' Campylobacter agar. Analysis of 12 artificially and 36 naturally contaminated samples indicated no significant differences in Campylobacter counts obtained with all three selective media. Lin's concordance correlation coefficient (CCC) and the Bland-Altman plot revealed a high level of agreement between Campylobacter counts when evaluating RAPID versus mCCDA and CFA plates. RAPID agar was the only medium tested that could effectively suppress the growth of the background microflora with naturally contaminated samples. Results of this study clearly indicated that RAPID agar is highly selective without loss of sensitivity for recovering Campylobacter. Results obtained are in agreement with those for other commonly used media; therefore, RAPID medium is suitable for Campylobacter enumeration in poultry meat samples.

  3. Induction of E-cadherin+ human amniotic fluid cell differentiation into oocyte-like cells via culture in medium supplemented with follicular fluid.

    PubMed

    Liu, Te; Huang, Yongyi; Bu, Yanzhen; Zhao, Yanhui; Zou, Gang; Liu, Zhixue

    2014-07-01

    Pluripotent human amniotic fluid cells (HuAFCs) can differentiate into various types of somatic cell in vitro. However, their differentiation into oocyte-like cells has never been described to the best of our knowledge. In the present study, differentiation of E-cadherin+ and E-cadherin- HuAFC sub-populations into oocyte-like cells was induced via culture in medium containing bovine follicular fluid and β-mercaptoethanol. The E-cadherin+ HuAFCs expressed DAZL highly. Post-induction, cells with an oocyte-like phenotype were found among the E-cadherin+ HuAFCs, expressing markers specific to germ cells and oocytes (VASA, ZP3 and GDF9) and meiosis (DMC1 and SCP3). When specific small interfering RNA (siRNA) was used to suppress E-cadherin in the E-cadherin+ HuAFCs, the levels of DAZL expression were reduced. Post-induction, the morphology of the siRNA‑E‑cadherin HuAFCs was poorer and the expression levels of germ cell-specific markers were lower compared with those of the siRNA-mock HuAFCs. Therefore, E-cadherin+ HuAFCs could be more easily induced to differentiate into oocyte-like cells by bovine follicular fluid and β-mercaptoethanol. In addition, the E-cadherin+ HuAFCs exhibited potential characteristics of DAZL protein expression, and thus it was conjectured that bovine follicular fluid acts on DAZL protein and promotes E-cadherin+ HuAFC differentiation into oocyte-like cells.

  4. Induction of E-cadherin+ human amniotic fluid cell differentiation into oocyte-like cells via culture in medium supplemented with follicular fluid.

    PubMed

    Liu, Te; Huang, Yongyi; Bu, Yanzhen; Zhao, Yanhui; Zou, Gang; Liu, Zhixue

    2014-07-01

    Pluripotent human amniotic fluid cells (HuAFCs) can differentiate into various types of somatic cell in vitro. However, their differentiation into oocyte-like cells has never been described to the best of our knowledge. In the present study, differentiation of E-cadherin+ and E-cadherin- HuAFC sub-populations into oocyte-like cells was induced via culture in medium containing bovine follicular fluid and β-mercaptoethanol. The E-cadherin+ HuAFCs expressed DAZL highly. Post-induction, cells with an oocyte-like phenotype were found among the E-cadherin+ HuAFCs, expressing markers specific to germ cells and oocytes (VASA, ZP3 and GDF9) and meiosis (DMC1 and SCP3). When specific small interfering RNA (siRNA) was used to suppress E-cadherin in the E-cadherin+ HuAFCs, the levels of DAZL expression were reduced. Post-induction, the morphology of the siRNA‑E‑cadherin HuAFCs was poorer and the expression levels of germ cell-specific markers were lower compared with those of the siRNA-mock HuAFCs. Therefore, E-cadherin+ HuAFCs could be more easily induced to differentiate into oocyte-like cells by bovine follicular fluid and β-mercaptoethanol. In addition, the E-cadherin+ HuAFCs exhibited potential characteristics of DAZL protein expression, and thus it was conjectured that bovine follicular fluid acts on DAZL protein and promotes E-cadherin+ HuAFC differentiation into oocyte-like cells. PMID:24788191

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Fly agaric (Amanita muscaria) poisoning, case report and review.

    PubMed

    Satora, Leszek; Pach, Dorota; Butryn, Beata; Hydzik, Piotr; Balicka-Slusarczyk, Barbara

    2005-06-01

    Gathering and eating mushrooms and other plants containing psychoactive substances has become increasingly popular among young people experimenting with drugs. Dried fly agaric Amanita muscaria fruiting bodies were eaten by five young persons (18-21 years of age) at a party in order to evoke hallucinations. Visual and auditory hallucinations occurred in four of them, whereas a 18-year-old girl lost consciousness. The following morning, she went to the Clinic of Toxicology. Due to the fact that not all the active substances present in the fly agaric have been identified, and some of them have an effect after a period of latency, the patient was admitted for several days of observation during which check-up examinations were performed. After four days without any problems, she was discharged. The poisoning regressed with no organ complications. The remaining persons who had eaten the fly agaric were free from any complaints. PMID:15904689

  7. Method for Measuring Changes in Surface Tension on Agar

    PubMed Central

    Weisberg, David S.; Dworkin, Martin

    1983-01-01

    The surface tension of agar surfaces was determined by measuring the contact angles formed by drops of various hydrophobic liquids on the surface and then calculating the composite surface free energy function by solving a series of simultaneous equations derived from these data. This method was used to measure the change in the surface tension of agar produced by the addition of various concentrations of albumin. The resulting curve was typical of the effect of increasing concentrations of surfactants on surface tension. The method was compared with other methods of determining surface tension of solids, and it was concluded that the technique used here provided the most reliable results. PMID:16346273

  8. Effects of Temperature, Water Activity, and Incubation Time on Production of Aflatoxins and Cyclopiazonic Acid by an Isolate of Aspergillus flavus in Surface Agar Culture

    PubMed Central

    Gqaleni, N.; Smith, J. E.; Lacey, J.; Gettinby, G.

    1997-01-01

    An experiment with a full factorial design was used to study the effects of and interactions among temperature, water activity (a(infw)), incubation period, and substrate on coproduction of aflatoxins (AF) and cyclopiazonic acid (CPA) by an isolate of Aspergillus flavus. Analysis of variance showed that there was a complex interaction among all of these factors and that this influenced the relative concentrations of the mycotoxins produced. The optimum temperatures for the production of AF and CPA were 30(deg)C and 25(deg)C, respectively. Both mycotoxins were maximally produced (0.306 to 0.330 (mu)g of AF(middot)ml of medium(sup-1), 4.040 to 6.256 (mu)g of CPA(middot)ml of medium(sup-1)) at an a(infw) of 0.996 and after 15 days of incubation. No AF were produced in either yeast extract agar or Czapek yeast autolysate agar medium at an a(infw) of 0.90 at 20 or 37(deg)C after 15 days (minimum conditions), while 0.077 to 0.439 (mu)g of CPA(middot)ml of medium(sup-1) was produced under the same conditions. Yeast extract agar favored maximum AF production, and Czapek yeast autolysate agar favored maximum CPA production. PMID:16535539

  9. Is blood agar an alternative to sabouraud dextrose agar for the isolation of fungi in patients with mycotic keratitis.

    PubMed

    Reddy, Ashok Kumar; Brahmaiah, Upputuri; Narayen, Nitesh; Reddy, Ravi Kumar; Reddy, Rupak Kumar; Chitta, Meghraj; Prasad, Srinivas; Swarup, Rishi; Mohiuddin, Syed Maaz; Reddy, Madhukar; Aasuri, Murali K; Murthy, B S R; Bhide, Milind; Ahmed, Sajid

    2013-06-01

    To compare the blood agar (BA), sabouraud dextrose agar (SDA) and chocolate agar (CA) for the isolation of fungi in patients with mycotic keratitis. Corneal Scrapings of 229 patients with clinically diagnosed microbial keratitis were inoculated on BA, SDA, CA. The culture media were evaluated for the rate and time taken for the fungal growth. Seventy six of 229 patients had fungal keratitis. Fungus grew on BA in 60/76(78.9 %), on SDA in 76/76 (100 %), on CA in 40/76(52.6 %) patients. The fungi which grew on BA (60/76) also grown on SDA at the same time. The colony morphologies of different fungi were better on SDA than BA/CA. Among the different culture media, SDA is essential for the isolation fungi in patients with mycotic keratitis.

  10. Developmental competence and embryo quality of small oocytes from pre-pubertal goats cultured in IVM medium supplemented with low level of hormones, insulin-transferrin-selenium and ascorbic acid.

    PubMed

    Hammami, S; Morató, R; Romaguera, R; Roura, M; Catalá, M G; Paramio, M T; Mogas, T; Izquierdo, D

    2013-04-01

    The aim of this study was to test the effect of insulin-transferrin-selenium (ITS) and L-ascorbic acid (AA) supplementation and the hormonal level during in vitro maturation (IVM) of small oocytes from pre-pubertal goat on the blastocyst yield and quality. Concretely, we used four maturation media: conventional IVM medium (CM), growth medium (GM: CM+ITS+AA and low level of hormones), modified CM (mCM: CM with low level of hormones) and modified GM (mGM: CM+ITS+AA and normal level of hormones). Cumulus-oocyte complexes (COCs) were classified into two categories according to oocyte diameter: <125 μm and ≥ 125 μm. Large oocytes were matured 24 h in CM (Treatment A). Small oocytes were matured randomly in six experimental groups: Treatment B: 24 h in CM; Treatment C: 12 h in GM and 12 h in CM; Treatment D: 24 h in mGM; Treatment E: 12 h in mGM and 12 h in CM; Treatment F: 12 h in mCM and 12 h in CM; and Treatment G: 12 h in GM and 12 h in mGM. After IVM, oocytes were fertilized and cultured for 8 days. The blastocyst quality was assessed by the survival following vitrification/warming and the mean cell number. When different maturation media were combined, the blastocyst rate did not improve. The large oocytes produced the highest blastocysts yield. However, the culture of small oocytes in GM (53.3%) enhanced the post-warming survival of blastocysts compared to large oocytes matured in CM (35.7%). In conclusion, IVM of pre-pubertal goat small oocytes in GM would be useful to improve the quality of in vitro-produced blastocysts.

  11. How do microorganisms influence trace element uptake by plants? Screening in an agar model rhizosphere.

    NASA Astrophysics Data System (ADS)

    Marchetti, M.; Robinson, B. H.; Evangelou, M. W. H.; Vachey, A.; Schwitzguebel, J. P.; Bernier-Latmani, R.; Schulin, R.

    2009-04-01

    sterile, transparent plastic boxes, whose lid was equipped with a filter allowing gas exchanges without contamination by external microorganisms. The seed surface was sterilised and the plants grew one week in agar before their rhizosphere was inoculated with LB broth containing a pure bacterial strain or agar plugs colonized by fungal hyphae. We tested 14 strains, with 5 replicates per treatment and a control where the system was inoculated with sterile LB broth. The plants grew for 2 weeks in a climate chamber and their shoots were analysed for their TEs by ICP-OES. Samples of agar and roots were collected to confirm microbial colonization of the rhizosphere, respectively sterile conditions in the control treatments. Concerning the method development, the plants grew without visible toxicity in all the boxes, and the analysis of root and agar samples indicated that the controls were sterile and the strains inoculated were growing along the roots. More than 90% of the TE and nutrients added to the system were in the liquid fraction of the agar medium, thus available for root uptake. The screening showed that the microorganisms in general decreased TE uptake by wheat and sunflower, although some of them had an opposite effect on the plants. However, with the same plant species, the microorganisms had a consistent effect on all TE tested, i.e. a given single strain caused the same effect (increase or decrease of TE uptake) on all TE tested. In sunflower, 3 microorganisms (Paenibacillus polymyxa, Pythium ultimum and Rhizoctonia solani) decreased Cu and Zn uptake by 50% compared to the control treatment. These three species are common soil microorganisms. All three are known to exude auxin, a phytohormone. This hormone can modify root morphology and physiology and thus may affect TE uptake by plants. R. solani and P. ultimum are root pathogens. Their effect was opposite to what we expected. If roots are damaged, TE should have flooded into the plant and accumulate in the

  12. A comparison of the performance of commercially available chromogenic agars for the isolation and presumptive identification of organisms from urine

    PubMed Central

    Fallon, D; Ackland, G; Andrews, N; Frodsham, D; Howe, S; Howells, K; Nye, K J; Warren, R E

    2003-01-01

    Aims: To compare four media—UTI medium, BBL CHROMagar, CPS ID2, and Harlequin CLED—using a collection of fully characterised organisms and subsequent “field trial”. Methods: Seven hundred and eighty seven fully characterised isolates (730 Gram negative bacteria, 47 Gram positive bacteria, and 10 yeasts) were used to test for accuracy of organism identification. To assess isolation rates and ability to detect mixed cultures, 1435 urine samples were cultured in the three best performing chromogenic media (UTI medium, BBL CHROMagar, and CPS ID2) and CLED. Results: The chromogenic agars differed in their accuracy of identification, with BBL CHROMagar performing best and Harlequin CLED performing least well. Similarly, BBL CHROMagar achieved a higher overall isolation rate than UTI medium and CPS ID2. When mixed growth was defined as greater than two organism types, BBL CHROMagar detected more mixed cultures than did UTI medium and CPS ID2, although the differences were not significant. When mixed growth was defined as greater than one organism type the increased number of mixed growths detected by BBL CHROMagar became significant, largely because of differences in enterococcal isolation rates. Conclusion: The use of BBL CHROMagar, UTI medium, or CPS ID2 chromogenic agar as a replacement for CLED agar would improve the detection rate of contaminated urine samples. Enhanced identification helps to distinguish different species, facilitating the monitoring of bacterial resistance in support of the national antibiotic strategy. BBL CHROMagar gave the highest overall organism recovery rates, greatest ability to detect mixed cultures, and the most accurate identification of organisms. PMID:12890812

  13. Fusobacterium necrophorum- detection and identification on a selective agar.

    PubMed

    Bank, Steffen; Nielsen, Hanne Merete; Mathiasen, Boris Hoyer; Leth, Dorte Christiansen; Kristensen, Lena Hagelskjaer; Prag, Jørgen

    2010-12-01

    Within the last decade, Fusobacterium necrophorum subsp. funduliforme has been considered a clinically important pathogen causing pharyngitis especially in adolescents and young adults. F. necrophorum pharyngitis can progress into Lemierre's syndrome, which is a severe and life-threatening infection. However, throat swabs are not cultured anaerobically in the routine and even if cultured anaerobically, it can be difficult to identify F. necrophorum from the normal flora of the throat. F. necrophorum is therefore often overlooked as the cause of pharyngitis. In our laboratory, a F. necrophorum selective agar has been developed containing vancomycin and nalidixin, which inhibit the growth of most Gram-positive and many Gram-negative bacteria, respectively. β-haemolysis of horse blood can be detected, which further facilitates the detection and identification of F. necrophorum. The F. necrophorum selective agar was evaluated against a quantitative real-time polymerase chain reaction assay and shown to have a significantly higher sensitivity for detecting F. necrophorum than the anaerobic agar commonly used in Denmark. Furthermore, the F. necrophorum selective agar does not require experienced laboratory technicians, require fewer subcultures, is probably less expensive and is faster to perform than other culture methods.

  14. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  15. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  16. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  17. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  18. 21 CFR 866.4600 - Ouchterlony agar plate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ouchterlony agar plate. 866.4600 Section 866.4600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents §...

  19. Improving agar electrospinnability with choline-based deep eutectic solvents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One percent agar (% wt) was dissolved in the deep eutectic solvent (DES), (2-hydroxyethyl) trimethylammonium chloride/urea at a 1:2 molar ratio, and successfully electrospun into nanofibers. An existing electrospinning set-up, operated at 50 deg C, was adapted for use with an ethanol bath to collect...

  20. Growth kinetics of three species of Tetrahymena on solid agar

    SciTech Connect

    Dobra, K.W.; McArdle, E.W.; Ehret, C.F.

    1980-01-01

    A nutrient-agar method without liquid overlay has been developed for cultivation of ciliates. Three species of Tetrahymena-T. pyriformis strain W, T. rostrata strain UNI, and T. vorax strain V/sub 2/S, representing the 3 main groups of Tetrahymena species, were used; however the method should apply to other ciliates. Growth on the surface of the agar was facilitated by an optimal surface-to-volume ratio yielding a high density of ciliates and short generation times. At the highest density achieved, the cells became irregularly hexagonal and formed a monolayer tissue on the agar. Ciliates grown on agar were like those in liquid culture, typical oral ciliature, food-vacuole formation, and typical cortical patterns being retained. Advantages of this method include high cell density, easy recovery, and optimal O/sub 2/ supply. The organisms can also be cultivated on the surface of sterile cellulose-nitrate filters, facilitating in situ fixation and staining as well as transfer into different media by transfer of filters with cells, without prior centrifugation and resuspension.

  1. Evaluation of use of a new chromogenic agar in detection of urinary tract pathogens.

    PubMed

    Samra, Z; Heifetz, M; Talmor, J; Bain, E; Bahar, J

    1998-04-01

    CHROMagar Orientation, a new chromogenic medium, was evaluated for the detection and differentiation of gram-positive and gram-negative pathogenic microorganisms in 900 urine samples from hospitalized patients. Performance characteristics of the medium were evaluated in comparison to those of 5% sheep blood and MacConkey agars by direct inoculation of the urine samples on the three media. Four gram-negative and two gram-positive strains as well as one yeast control strain from the American Type Culture Collection were used to ensure quality control. CHROMagar Orientation succeeded in detecting all the urine pathogens that were detected by the reference media, including gram-negative bacilli, staphylococci, streptococci, and yeasts. Colony color and morphology on CHROMagar Orientation accurately differentiated Escherichia coli, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, and Acinetobacter spp. Owing to the similarity in the pigmentation produced by Klebsiella, Enterobacter, and Citrobacter isolates, the medium failed to distinguish among them; however, these isolates were easily recognized as coliforms because of their metallic blue coloration. Staphylococci were clearly perceptible: S. aureus and S. epidermidis grow in regular-size colonies that range from opaque white to yellowish, and S. saprophyticus produces opaque pink colonies. All streptococcus strains, including those from groups B and C, were detected. They grow as undifferentiated flat dry diffused colonies, and additional tests were required for identification. Enterococci were easily discriminated by their strong turquoise pigmentation and their typical growth on the agar's surface. Yeast grow in typical creamy wet convex colonies. The accuracy of antibiotic susceptibility determinations according to standard methods was also tested by picking isolates directly from CHROMagar Orientation. The results showed excellent correlation with those obtained with microorganisms picked from

  2. STUDIES ON THE USE OF AMPICILLIN-DEXTRIN AGAR ASAS AEROMONAS RECOVERY MEDIUM

    EPA Science Inventory

    The Contaminant Candidate List (CCL) includes the unregulated chemical and microbiological contaminants the EPA has identified as possibly posing a significant public risk to consumers if present in drinking water (1). There are three bacterial species listed in the CCL (Aeromon...

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

    PubMed

    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.

  4. Total Antioxidant Capacity of Serum Determined Using the Potassium Permanganate Agar Method Based on Serum Diffusion in Agar

    PubMed Central

    Zhou, Ying; Zhang, Meijuan; Liu, Hui

    2015-01-01

    Objectives. To develop a new method for determining total antioxidants in serum and to evaluate the total antioxidant capacity of organisms. Design and Methods. Sodium hyposulfite (Na2S2O3) and serum were used to evaluate the linearity and precision of the potassium permanganate agar method. The area of serum diffusion in samples from 30 intensive care unit (ICU) patients compared with 44 healthy subjects was determined by the potassium permanganate agar method. Results. The linearity (R2 in the linear experiment of Na2S2O3 was 0.994; R2 in the linear experiment of serum was 0.987) and precision (coefficient of variation of area of high level serum diffusion within-run, between-run, and between-day and coefficient of variation of area of low serum diffusion within-run, between-run, and between-day were all less than 10%) were acceptable using the potassium permanganate agar method. Total antioxidants of serum between the ICU group and the healthy group were different (p = 0.002, two tailed). Conclusions. Total antioxidants in serum can be determined by the potassium permanganate agar method. The total antioxidant capacity of an organism can be evaluated by the amount of total antioxidants in serum. PMID:26347595

  5. Agar-agar entrapment increases the stability of endo-β-1,4-xylanase for repeated biodegradation of xylan.

    PubMed

    Bibi, Zainab; Shahid, Faiza; Ul Qader, Shah Ali; Aman, Afsheen

    2015-04-01

    Microbial xylanases, specially endo-β-1,4-xylanase catalyzes the hydrolysis of xylan, is considered one of the most significant hydrolases. It has numerous applications but most extensively is utilized in paper and pulp industry as a bio-bleaching agent. Immobilization technique is comprehensively studied with the expectation of modifying and improving enzyme stability and characteristics for commercial purposes. Currently, matrix entrapment technique is applied to immobilize endo-β-1,4-xylanase within agar-agar gel beads produced by Geobacillus stearothermophilus KIBGE-IB29. Maximal enzyme immobilization yield was achieved at 2.5% of agar-agar concentration. Optimized conditions demonstrated an increase in the optimal reaction time from 05 min to 30 min and incubation temperature from 50 °C to 60 °C with reference to free enzyme whereas; no effect was observed for optimum pH. Entrapment technique uniquely changed the kinetic parameters of immobilized endo-β-1,4-xylanase (Km: 0.5074 mg min(-1) to 0.5230 mg min(-1) and Vmax: 4773 U min(-1) to 968 U min(-1)) as compared to free enzyme. However, immobilized enzyme displayed broad thermal stability and retained 79.0% of its initial activity at 80 °C up to 30 min whereas; free enzyme completely lost its activity at this temperature. With respect to economic feasibility, the immobilized enzyme showed impressive recycling efficiency up to six reaction cycles. PMID:25603143

  6. Thermal-induced ageing of agar solutions: impact on the structural and mechanical properties of agar gels

    NASA Astrophysics Data System (ADS)

    Mao, Bosi; Bentaleb, Ahmed; Louerat, Frédéric; Divoux, Thibaut; Snabre, Patrick

    Numerous hydrogels are prepared by cooling down to ambient temperature, aqueous polymer solutions brought to a boil. Although the incubation time of the polymer solution at such a high temperature could be used as a tuning parameter, its impact on the subsequent gelation has been poorly investigated. Here we study the effect of prolonged heating at 80°C on a 1.5% wt solution of agar, a natural polysaccharide. The incubation time is varied from a few hours up to five days. We show that the agar sol. continuously degrades as the result of both the hydrolysis and the intermolecular oxidation of the polymer chains. Furthermore, electronic microscopy and X-ray diffraction experiments reveal that gels formed from older agar sols display an increasingly coarser microstructure composed of micron-sized aggregated pieces of polysaccharides, in contrast with the fibrous-like structure of gels made from fresh sols. Along with structural changes prolonged incubation time leads to weaker gels of lower shear elastic modulus. Finally, macro-indentation experiments coupled to direct visualization show that increasing the incubation time of the agar sol. decreases the yield strain of the gel by a factor of three, while the rupture scenario turns continuously from brittle to ductile-like. Acknowledging funding from BioMérieux & CNRS.

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

    PubMed Central

    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

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

    PubMed

    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 (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. PMID:25170941

  9. Use of hydrogen peroxide treatment and crystal violet agar plates for selective recovery of bacteriophages from natural environments

    SciTech Connect

    Asghari, A.; Farrah, S.R.; Bitton, G. )

    1992-04-01

    Hydrogen peroxide inactivated bacteriophages and bacteria at different rates. A concentration of 0.1% hydrogen peroxide reduced the numbers of several bacteria by an average of 94% but caused an average of 25% inactivation in the numbers of bacteriophages tested. Treating natural samples with hydrogen peroxide selectively reduced the indigenous bacterial flora and permitted better visualization of plaques of lawns of Escherichia coli C-3000. In some cases indigenous gram-positive bacteria were relatively resistant to hydrogen peroxide, but their growth could be limited by incorporation of crystal violet into the bottom agar used for plaque assays. The use of hydrogen peroxide treatment and crystal violet-containing plates permitted recovery of more phages from natural samples than did other procedures, such as chloroform pretreatment or the use of selective plating agar such as EC medium.

  10. Isolation of marine bacteria by in situ culture on media-supplemented polyurethane foam.

    PubMed

    Yasumoto-Hirose, Mina; Nishijima, Miyuki; Ngirchechol, Metiek Kimie; Kanoh, Kaneo; Shizuri, Yoshikazu; Miki, Wataru

    2006-01-01

    Polyurethane foam (PUF) supplemented with various agar media was used in situ to trap marine bacteria and it consequently provided a substrate on which they could be cultivated while exposed to natural seawater in the coral reef area. The bacterial population on the PUF blocks was analyzed by denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR)-amplified 16S rDNA fragments. Changing the composition of the cultivation medium in the PUF blocks and selecting different sampling sites resulted in different bacteria being detected on the PUF blocks. For example, iron-utilizing (IU) bacteria, siderophore-producing (SP) bacteria, and petroleum-degrading (PD) bacteria were isolated from PUF blocks and it was discovered that IU and SP contained iron and PD contained hydrocarbon. This method opens up the possibility for isolating novel and useful marine bacteria.

  11. Characteristics of rat megakaryocyte colonies and their progenitors in agar culture

    SciTech Connect

    Kellar, K.L.; Rolovic, Z.; Evatt, B.L.; Sewell, E.T.

    1985-11-01

    The characteristics of megakaryocyte colonies that develop from megakaryocyte progenitors of rat bone marrow stimulated by rat spleen-conditioned medium (SCM) in agar culture were investigated. Colony frequency was optimal on day 7 and increased relative to both the number of cells plated and the concentration of SCM used. Colonies were categorized as small cell and big cell. Small-cell colonies had a greater proliferative potential, with a mean of 25 cells/colony. Big-cell colonies averaged 15 cells/colony. The ratio of big-cell to small-cell colonies was 0.69 +/- 0.29. Granulocyte-macrophage colonies, which were also stimulated by SCM, accounted for 70% +/- 15% of the total colonies in the cultures. Cytocidal experiments with tritiated thymidine reduced megakaryocyte colony formation by 45% and granulocyte-macrophage colony formation by 21%. The properties of rat, mouse, and human megakaryocyte progenitors as assayed in vitro are compared.

  12. Injection of Acanthaster planci with thiosulfate-citrate-bile-sucrose agar (TCBS). I. Disease induction.

    PubMed

    Rivera-Posada, J A; Pratchett, M; Cano-Gómez, A; Arango-Gómez, J D; Owens, L

    2011-12-01

    This is the first report of the successful induction of a transmissible disease in the coral-eating crown-of-thorns starfish Acanthaster planci (COTS). Injection of thiosulfate-citrate-bile-sucrose agar (TCBS) culture medium into COTS induced a disease characterized by discoloured and necrotic skin, ulcerations, loss of body turgor, accumulation of colourless mucus on many spines especially at their tip, and loss of spines. Blisters on the dorsal integument broke through the skin surface and resulted in large, open sores that exposed the internal organs. Oedema and reddened digestive tissues and destruction of connective fibers were common. Moreover, healthy COTS in contact with these infected animals also displayed signs of disease and died within 24 h. TCBS induced 100% mortality in injected starfish. There was no introduction of new pathogens into the marine environment. TCBS promoted the growth of COTS' naturally occurring Vibrionales to high densities with subsequent symbiont imbalance followed by disease and death.

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

    PubMed

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

    2008-10-01

    The main aim of this study was to verify the efficacy of subculture on potato dextrose agar (PDA) as a complement to the in vitro susceptibility test for Malassezia pachydermatis strains by a broth microdilution method, as well as to determine the MIC and MFC of azole derivatives, amphotericin B and caspofungin. The microdilution assay was performed in 96-well plates using a modified RPMI 1640 medium. The M. pachydermatis strains were resistant to caspofungin. All strains (n=50) had shown MIC values of <0.03, <0.03, 2.0, 4.0 and 4.0 microg/ml for itraconazole, ketoconazole, voriconazole, fluconazole and amphotericin B, respectively. Thus, the subculture on PDA improved the analysis of the in vitro antifungal susceptibility of M. pachydermatis.

  14. Comparison of dosimetry gels prepared by agar and bovine gelatine

    NASA Astrophysics Data System (ADS)

    Sağsöz, M. E.; Korkut, Ö.; Alemdar, N.; Aktaş, S.; Çalı, E. B.; Kantarcı, M.

    2016-04-01

    Gel dosimeters are unique materials capable of showing three dimensional (3D) dose distributions of therapeutic or diagnostic exposures. Fricke gel dosimeters can be considered as chemical dosimeters that rely on a radiation-induced chemical reaction. Dose distribution of Fricke solutions containing Fe+2 ions determines the transformation of acidic, oxygen saturated Fe+2 ions to Fe+3 ions by the ionizing radiation in aqueous solutions. In this study we produced two different types of gel dosimeters using agar and bovine gelatin with similar fabrication methods. We compared the magnetic resonance (MR) T1 imaging responses of these two gel dosimeters to acquire a dose dependency of MR intensities. In conclusion agar gel dosimeters found to be produced easily and more consistent.

  15. A modified agar plate method for detection of Strongyloides stercoralis.

    PubMed

    Koga, K; Kasuya, S; Khamboonruang, C; Sukhavat, K; Ieda, M; Takatsuka, N; Kita, K; Ohtomo, H

    1991-10-01

    The agar plate method is a new technique with high detection rates for coprological diagnosis of human strongyloidiasis. This report details modifications of the technique and establishes a standardized procedure. We recommend that all plates should be carefully observed using a microscope because macroscopic observation can lead to false negative results. It is also advisable to pour formalin solution directly into microscopically positive dishes to collect worms by sedimentation. This procedure enables one to observe worms otherwise hidden. Sealing dishes with adhesive tape prevents larvae from crawling out of the dishes, eliminating any possibility in the reduction of detection rates, and greatly improves the safety conditions for the technician performing the procedure. We consider the agar plate method to be superior to the filter paper method in detecting Strongyloides, and we believe that it will eventually become the technique of choice. PMID:1951861

  16. How do microorganisms influence trace element uptake by plants? Screening in an agar model rhizosphere.

    NASA Astrophysics Data System (ADS)

    Marchetti, M.; Robinson, B. H.; Evangelou, M. W. H.; Vachey, A.; Schwitzguebel, J. P.; Bernier-Latmani, R.; Schulin, R.

    2009-04-01

    sterile, transparent plastic boxes, whose lid was equipped with a filter allowing gas exchanges without contamination by external microorganisms. The seed surface was sterilised and the plants grew one week in agar before their rhizosphere was inoculated with LB broth containing a pure bacterial strain or agar plugs colonized by fungal hyphae. We tested 14 strains, with 5 replicates per treatment and a control where the system was inoculated with sterile LB broth. The plants grew for 2 weeks in a climate chamber and their shoots were analysed for their TEs by ICP-OES. Samples of agar and roots were collected to confirm microbial colonization of the rhizosphere, respectively sterile conditions in the control treatments. Concerning the method development, the plants grew without visible toxicity in all the boxes, and the analysis of root and agar samples indicated that the controls were sterile and the strains inoculated were growing along the roots. More than 90% of the TE and nutrients added to the system were in the liquid fraction of the agar medium, thus available for root uptake. The screening showed that the microorganisms in general decreased TE uptake by wheat and sunflower, although some of them had an opposite effect on the plants. However, with the same plant species, the microorganisms had a consistent effect on all TE tested, i.e. a given single strain caused the same effect (increase or decrease of TE uptake) on all TE tested. In sunflower, 3 microorganisms (Paenibacillus polymyxa, Pythium ultimum and Rhizoctonia solani) decreased Cu and Zn uptake by 50% compared to the control treatment. These three species are common soil microorganisms. All three are known to exude auxin, a phytohormone. This hormone can modify root morphology and physiology and thus may affect TE uptake by plants. R. solani and P. ultimum are root pathogens. Their effect was opposite to what we expected. If roots are damaged, TE should have flooded into the plant and accumulate in the

  17. Modeling development of inhibition zones in an agar diffusion bioassay

    PubMed Central

    Chandrasekar, Vaishnavi; Knabel, Stephen J; Anantheswaran, Ramaswamy C

    2015-01-01

    A two-temperature agar diffusion bioassay is commonly used to quantify the concentration of nisin using Micrococcus luteus as the indicator microorganism. A finite element computational model based on Fick's second law of diffusion was used to predict the radius of the inhibition zone in this diffusion bioassay. The model developed was used to calculate nisin concentration profiles as a function of time and position within the agar. The minimum inhibitory concentration (MIC) of nisin against M. luteus was determined experimentally. The critical time (Tc) for growth of M. luteus within the agar diffusion bioassay was experimentally determined using incubation studies with nisin. The radius of the inhibition zone was predicted from the computational model as the location where the predicted nisin concentration at Tc was equal to MIC. The MIC was experimentally determined to be 0.156 μg mL−1, and Tc was determined to be 7 h. Good agreement (R2 = 0.984) was obtained between model-predicted and experimentally determined inhibition zone radii. PMID:26405525

  18. Modeling development of inhibition zones in an agar diffusion bioassay.

    PubMed

    Chandrasekar, Vaishnavi; Knabel, Stephen J; Anantheswaran, Ramaswamy C

    2015-09-01

    A two-temperature agar diffusion bioassay is commonly used to quantify the concentration of nisin using Micrococcus luteus as the indicator microorganism. A finite element computational model based on Fick's second law of diffusion was used to predict the radius of the inhibition zone in this diffusion bioassay. The model developed was used to calculate nisin concentration profiles as a function of time and position within the agar. The minimum inhibitory concentration (MIC) of nisin against M. luteus was determined experimentally. The critical time (T c) for growth of M. luteus within the agar diffusion bioassay was experimentally determined using incubation studies with nisin. The radius of the inhibition zone was predicted from the computational model as the location where the predicted nisin concentration at T c was equal to MIC. The MIC was experimentally determined to be 0.156 μg mL(-1), and T c was determined to be 7 h. Good agreement (R (2) = 0.984) was obtained between model-predicted and experimentally determined inhibition zone radii.

  19. [TMOSKOVHE COMPARATIVE CHARACTERISTIC OF GROWTH MEDIUMS FOR SEPARATION OF CORYNEBACTERIA].

    PubMed

    Shepelin, A P; Polosenko, O V; Borisova, O Yu; Pimenova, A S; Gadua, N T

    2016-01-01

    The comparative tests of growth mediums for isolation and accumulation of diphtheria bacteria were implemented. The testing consisted of six series of growth medium "Corynebacagar" produced by the state research center of applied microbiology and biotechnology and three series of blood tellurite agar. The concluding results of identification of biological indicators of all series of growth nutrient mediums are presented The "Corynebacagar" is recommended for application in health care practice for primary inoculation of pathological material during implementation of cultural analysis on diphtheria.

  20. New medium for improved recovery of coliform bacteria from drinking water.

    PubMed Central

    LeChevallier, M W; Cameron, S C; McFeters, G A

    1983-01-01

    A new membrane filter medium was developed for the improved recovery of injured coliforms from drinking water. The new medium, termed m-T7, consists of 5.0 g of Difco Proteose Peptone no. 3, 20 g of lactose, 3.0 g of yeast extract, 0.4 ml of Tergitol 7 (25% solution), 5.0 g of polyoxyethylene ether W-1, 0.1 g of bromthymol blue, 0.1 g of bromcresol purple, and 15 g of agar per liter of distilled water. Additional selectivity may be obtained by aseptically adding 0.1 microgram of penicillin G per ml to the medium after autoclaving. In laboratory studies, m-T7 agar recovered 86 to 99% more laboratory-injured coliforms than did m-Endo agar. m-T7 agar also recovered an average of 43% more verified coliforms from 67 surface and drinking water samples than did the standard m-Endo membrane filter technique. From drinking water, m-T7 agar recovered nearly three times more coliforms than did m-Endo agar. Less than 0.5% of the colonies on m-T7 agar gave false-negative reactions, whereas greater than 70% of the typical yellow colonies from m-T7 agar produced gas in lauryl tryptose broth. Most of the verified coliforms isolated on m-T7 agar belonged to one of the four common coliform genera: Escherichia, 17.6%; Klebsiella, 21.7%; Citrobacter, 17.3%; Enterobacter, 32.2%. The results demonstrate that m-T7 agar is superior to m-Endo agar, especially for the isolation of injured coliforms from drinking water. PMID:6338827

  1. [Titration of Ebola and Marburg viruses by plaque formation under semi liquid agar].

    PubMed

    Ustinova, E N; Shestopalov, A M; Bakulina, L F; Chepurnov, A A

    2003-01-01

    The method of titration of Ebola and Marburg viruses using plaque formation under semifluid agar cover is considered. Advantages of this method over conventional method of titration of these viruses with the use of hard agar cover are discussed.

  2. Differential recovery of Streptococcus mutans from various mitis-salivarius agar preparations.

    PubMed Central

    Liljemark, W F; Okrent, D H; Bloomquist, C G

    1976-01-01

    Recoveries of Streptococcus mutans from human dental plaque were lower when plated on mitis-salivarius agar obtained from Baltimore Biological Laboratories as compared with mitis-salivarius agar obtained from Difco Laboratories. However, no difference in recoveries of established laboratory strains of S. mutans was observed between these two agar preparations. PMID:956358

  3. Electrospinning of agar/PVA aqueous solutions and its relation with rheological properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this work, we report the successful fabrication of agar-based nanofibers by an electrospinning technique using water as the solvent media. A tubeless spinneret was attached inside the electrospinning chamber, operated at 50 deg C, to avoid agar gelation. Pure agar solution 1% (w/w) showed inadequ...

  4. Dietary Supplements

    MedlinePlus

    Dietary supplements are vitamins, minerals, herbs, and many other products. They can come as pills, capsules, powders, drinks, ... possible Tell your health care provider about any dietary supplements you use Do not take a bigger dose ...

  5. Replica plating of colonies from Listeria-selective agars to blood agar to improve the isolation of Listeria monocytogenes from foods.

    PubMed

    Cassiday, P K; Graves, L M; Swaminathan, B

    1990-07-01

    Bacterial colonies from Listeria-selective agars were replica plated to sheep blood agar to screen for beta-hemolysis. By using the replica plating method to test for the beta-hemolytic characteristic of all the colonies growing on Listeria-selective agars instead of picking 3 to 10 suspected colonies for further testing, we recovered Listeria monocytogenes from 59 of 142 Listeria-selective agar plates which contained colonies of hemolytic and nonhemolytic Listeria species and were negative when tested by conventional colony picks.

  6. Development of blood-yolk-polymyxin B-trimethoprim agar for the enumeration of Bacillus cereus in various foods.

    PubMed

    Kim, Dong-Hyeon; Kim, Hyunsook; Chon, Jung-Whan; Moon, Jin-San; Song, Kwang-Young; Seo, Kun-Ho

    2013-07-15

    Blood-yolk-polymyxin B-trimethoprim agar (BYPTA) was developed by the addition of egg yolk, laked horse blood, sodium pyruvate, polymyxin B, and trimethoprim, and compared with mannitol-yolk-polymyxin B agar (MYPA) for the isolation and enumeration of Bacillus cereus (B. cereus) in pure culture and various food samples. In pure culture, there was no statistical difference (p>0.05) between the recoverability and sensitivity of MYPA and BYPTA, whereas BYPTA exhibited higher specificity (p<0.05). To evaluate BYPTA agar with food samples, B. cereus was experimentally spiked into six types of foods, triangle kimbab, sandwich, misugaru, Saengsik, red pepper powder, and soybean paste. No statistical difference was observed in recoverability (p>0.05) between MYPA and BYPTA in all tested foods, whereas BYPTA exhibited higher selectivity than MYPA, especially in foods with high background microflora, such as Saengsik, red pepper powder, and soybean paste. The newly developed selective medium BYPTA could be a useful enumeration tool to assess the level of B. cereus in foods, particularly with high background microflora.

  7. Inhibition of Aspergillus flavus on agar media and brown rice cereal bars using cold atmospheric plasma treatment.

    PubMed

    Suhem, Kitiya; Matan, Narumol; Nisoa, Mudtorlep; Matan, Nirundorn

    2013-02-01

    This study aimed to optimize the operating parameters of cold atmospheric plasma treatment to inhibit the growth of Aspergillus flavus on agar media and brown rice cereal bars. The effects of argon plasma jet treatment on the growth of A. flavus on malt extract agar (MEA) at powers of 20 W and 40 W with exposure times at 5, 15 and 25 min were studied using response surface methodology (RSM) with a central composite face-centered (CCF) design. Multiple regression analysis indicated that plasma treatment at 40 W for 25 min is most effective for inhibiting growth of A. flavus on the agar medium. On brown rice cereal bars, plasma powered at 40 W for 20 min was capable of giving protection against A. flavus growth for up to 20 days under storage conditions of 25°C and 100% RH. These results demonstrated the potential of cold atmospheric plasma jet treatment to control mold growth on various food products. PMID:23279819

  8. A new medium containing mupirocin, acetic acid, and norfloxacin for the selective cultivation of bifidobacteria.

    PubMed

    Vlková, Eva; Salmonová, Hana; Bunešová, Věra; Geigerová, Martina; Rada, Vojtěch; Musilová, Šárka

    2015-08-01

    Various culture media have been proposed for the isolation and selective enumeration of bifidobacteria. Mupirocin is widely used as a selective factor along with glacial acetic acid. TOS (transgalactosylated oligosaccharides) medium supplemented with mupirocin is recommended by the International Dairy Federation for the detection of bifidobacteria in fermented milk products. Mupirocin media with acetic acid are also reliable for intestinal samples in which bifidobacteria predominate. However, for complex samples containing more diverse microbiota, the selectivity of mupirocin media is limited. Resistance to mupirocin has been demonstrated by many anaerobic bacteria, especially clostridia. The objective was to identify an antibiotic that inhibits the growth of clostridia and allows the growth of bifidobacteria, and to use the identified substance to develop a selective cultivation medium for bifidobacteria. The susceptibility of bifidobacteria and clostridia to 12 antibiotics was tested on agar using the disk diffusion method. Only norfloxacin inhibited the growth of clostridia and did not affect the growth of bifidobacteria. Using both pure cultures and faecal samples from infants, adults, calves, lambs, and piglets, the optimal concentration of norfloxacin in solid cultivation media was determined to be 200 mg/L. Our results showed that solid medium containing norfloxacin (200 mg/L) in combination with mupirocin (100 mg/L) and glacial acetic acid (1 mL/L) is suitable for the enumeration and isolation of bifidobacteria from faecal samples of different origins.

  9. A new medium containing mupirocin, acetic acid, and norfloxacin for the selective cultivation of bifidobacteria.

    PubMed

    Vlková, Eva; Salmonová, Hana; Bunešová, Věra; Geigerová, Martina; Rada, Vojtěch; Musilová, Šárka

    2015-08-01

    Various culture media have been proposed for the isolation and selective enumeration of bifidobacteria. Mupirocin is widely used as a selective factor along with glacial acetic acid. TOS (transgalactosylated oligosaccharides) medium supplemented with mupirocin is recommended by the International Dairy Federation for the detection of bifidobacteria in fermented milk products. Mupirocin media with acetic acid are also reliable for intestinal samples in which bifidobacteria predominate. However, for complex samples containing more diverse microbiota, the selectivity of mupirocin media is limited. Resistance to mupirocin has been demonstrated by many anaerobic bacteria, especially clostridia. The objective was to identify an antibiotic that inhibits the growth of clostridia and allows the growth of bifidobacteria, and to use the identified substance to develop a selective cultivation medium for bifidobacteria. The susceptibility of bifidobacteria and clostridia to 12 antibiotics was tested on agar using the disk diffusion method. Only norfloxacin inhibited the growth of clostridia and did not affect the growth of bifidobacteria. Using both pure cultures and faecal samples from infants, adults, calves, lambs, and piglets, the optimal concentration of norfloxacin in solid cultivation media was determined to be 200 mg/L. Our results showed that solid medium containing norfloxacin (200 mg/L) in combination with mupirocin (100 mg/L) and glacial acetic acid (1 mL/L) is suitable for the enumeration and isolation of bifidobacteria from faecal samples of different origins. PMID:25865525

  10. Agar-Gel Precipitin Technique in Anthrax Antibody Determinations1

    PubMed Central

    Ray, John G.; Kadull, Paul J.

    1964-01-01

    A modification of the agar-gel precipitation inhibition technique of Thorne and Belton for detecting anthrax antibodies reduces inconsistency of visually determined end points on the same sera observed by different technicians. Determination of the minimal reacting concentrations of the anthrax antigen and antibody reagents, modifications of the visualization apparatus, methods for combining reagents, and length of incubation periods contribute to the ease of the end-point determinations and the uniformity of results. When compared with the previous technique, the modified procedure is less time-consuming while retaining satisfactory reproducibility, simplicity, specificity, and sensitivity. Images FIG. 1 FIG. 2 PMID:14201088

  11. Culture of Piscirickettsia salmonis on enriched blood agar.

    PubMed

    Mauel, Michael J; Ware, Cynthia; Smith, Pedro A

    2008-03-01

    Piscirickettsia salmonis is the etiologic agent of piscirickettsiosis, an economically significant disease of fish. Isolation of P. salmonis by culturing on fish cell lines has been the standard technique since the initial isolation of the organism. The ability to grow P. salmonis on artificial media would relieve facilities of the cost of maintaining cell lines, permit isolation at fish culture sites with fewer contamination problems, and allow easier transport of isolates to diagnostic facilities for confirmation assays. This report describes the successful culture of P. salmonis on enriched blood agar. PMID:18319435

  12. Evaluation of Urea-motility-indole medium for recognition and differentiation of Salmonella and Shigella species in stool cultures.

    PubMed Central

    Rosa Fraile, M; Vega Aleman, D; Fernandez Gutierrez, C

    1980-01-01

    A semisolid urea-motility-indole medium designed for detection in Enterobacteriaceae of urease activity, motility, and indole production in one tube was prepared and evaluated. The formulation of the medium was similar to that of Christensen urea agar, but the agar concentration was 0.2%, and 1% tryptone was added. Results with 687 strains of Enterobacteriaceae were the same as those obtained with standard test media (98% overall agreement). The urea-motility-indole medium was also used in combination with Kligler iron agar for the recognition and differentiation of Salmonella and Shigella species from colonies picked from plating media in fecal cultures. This combination was compared with the combination of Kligler iron agar and lysine iron agar with 507 strains of non-lactose-fermenting Enterobacteriaceae. Although both combinations enabled the presumptive recognition and differentiation of Salmonella and Shigella species, an analysis of data indicated that the combination of Kligler iron agar and urea-motility-indole medium performed better than the combination of Kligler iron agar and lysine iron agar in detecting Salmonella and Shigella species. PMID:7217332

  13. Prepartum concentrate supplementation of a diet based on medium-quality grass silage: Effects on performance, health, fertility, metabolic function, and immune function of low body condition score cows.

    PubMed

    Little, M W; O'Connell, N E; Welsh, M D; Barley, J; Meade, K G; Ferris, C P

    2016-09-01

    When cows with a "higher" body condition score (BCS) are oversupplied with energy during the dry period, postpartum energy balance is normally reduced, which can have a detrimental effect on immune competence and increase the infectious disease risk. However, within grassland-based systems higher yielding cows frequently have a low BCS at drying off. The effects on performance, health, and metabolic and immune functions of providing additional energy to cows with low BCS during the dry period is less certain. To address this uncertainty, 53 multiparous Holstein-Friesian cows (mean BCS of 2.5; 1-5 scale) were allocated to 1 of 2 treatments at dry-off: silage only or silage plus concentrates. Cows on the silage-only treatment were offered ad libitum access to medium-quality grass silage. Cows on the silage-plus-concentrate treatment were offered ad libitum access to a mixed ration comprising the same grass silage plus concentrates [in a 75:25 dry matter (DM) ratio], which provided a mean concentrate DM intake of 3.0kg/cow per day. Postpartum, cows were offered a common mixed ration comprising grass silage and concentrates (in a 40:60 DM ratio) for a 70-d period. Offering concentrates during the dry period increased DM intake, tended to increase energy balance, and increased body weight (BW) and BCS gain prepartum. Offering concentrates during the dry period increased BW and BCS loss postpartum and tended to increase milk fat percentage and serum nonesterified fatty acid concentration, but it did not affect postpartum DM intake, energy balance, and milk yield. Although the percentage of phagocytosis-positive neutrophils did not differ, neutrophils from cows on the silage-plus-concentrate treatment had higher phagocytic fluorescence intensity at 1 and 2 wk postpartum and higher phagocytic index at 1 wk postpartum. Serum haptoglobin concentrations and IFN-γ production by pokeweed mitogen stimulated whole blood culture were unaffected by treatment, although haptoglobin

  14. Prepartum concentrate supplementation of a diet based on medium-quality grass silage: Effects on performance, health, fertility, metabolic function, and immune function of low body condition score cows.

    PubMed

    Little, M W; O'Connell, N E; Welsh, M D; Barley, J; Meade, K G; Ferris, C P

    2016-09-01

    When cows with a "higher" body condition score (BCS) are oversupplied with energy during the dry period, postpartum energy balance is normally reduced, which can have a detrimental effect on immune competence and increase the infectious disease risk. However, within grassland-based systems higher yielding cows frequently have a low BCS at drying off. The effects on performance, health, and metabolic and immune functions of providing additional energy to cows with low BCS during the dry period is less certain. To address this uncertainty, 53 multiparous Holstein-Friesian cows (mean BCS of 2.5; 1-5 scale) were allocated to 1 of 2 treatments at dry-off: silage only or silage plus concentrates. Cows on the silage-only treatment were offered ad libitum access to medium-quality grass silage. Cows on the silage-plus-concentrate treatment were offered ad libitum access to a mixed ration comprising the same grass silage plus concentrates [in a 75:25 dry matter (DM) ratio], which provided a mean concentrate DM intake of 3.0kg/cow per day. Postpartum, cows were offered a common mixed ration comprising grass silage and concentrates (in a 40:60 DM ratio) for a 70-d period. Offering concentrates during the dry period increased DM intake, tended to increase energy balance, and increased body weight (BW) and BCS gain prepartum. Offering concentrates during the dry period increased BW and BCS loss postpartum and tended to increase milk fat percentage and serum nonesterified fatty acid concentration, but it did not affect postpartum DM intake, energy balance, and milk yield. Although the percentage of phagocytosis-positive neutrophils did not differ, neutrophils from cows on the silage-plus-concentrate treatment had higher phagocytic fluorescence intensity at 1 and 2 wk postpartum and higher phagocytic index at 1 wk postpartum. Serum haptoglobin concentrations and IFN-γ production by pokeweed mitogen stimulated whole blood culture were unaffected by treatment, although haptoglobin

  15. Physicochemical properties of biodegradable polyvinyl alcohol-agar films from the red algae Hydropuntia cornea.

    PubMed

    Madera-Santana, Tomás J; Robledo, Daniel; Freile-Pelegrín, Yolanda

    2011-08-01

    Agar obtained from the red alga Hydropuntia cornea was blended with polyvinyl alcohol (PVOH) in order to produce biodegradable films. In this study, we compare the properties of biopolymeric films formulated with agars extracted from H. cornea collected at different seasons (rainy and dry) in the Gulf of Mexico coast and PVOH as synthetic matrix. The films were prepared at different agar contents (0%, 25%, 50%, 75%, and 100%) and their optical, mechanical, thermal, and morphological properties analyzed. The tensile strength of PVOH-agar films increased when agar content was augmented. The formulation with 50% agar from rainy season (RS) had a significant higher tensile strength when compared to those from dry season (DS; p < 0.05). Tensile modulus also displayed an increasing trend and likewise, for 50% and 75% agar blends from RS showed higher values than those from DS (p < 0.05). In contrast, elongation at break decreased as the agar content increased, independently of the season. Environmental scanning electron microscopy images of PVOH-agar 75% biofilms from RS showed a homogeneous structure with good interfacial adhesion between the two components. The changes evidenced in the FTIR spectrum of this blend suggest that hydrogen bonding is taking place between the agar ether linkages (C-O-C) and the hydroxyl groups (OH) of the PVOH. Based on the above mentioned results, blends of PVOH and 75% agar from H. cornea collected in rainy season showed good properties for applications in the biodegradable packaging industry.

  16. Assessment of the suitability of mannitol salt agar for growing bovine-associated coagulase-negative staphylococci and its use under field conditions.

    PubMed

    De Visscher, A; Haesebrouck, F; Piepers, S; Vanderhaeghen, W; Supré, K; Leroy, F; Van Coillie, E; De Vliegher, S

    2013-10-01

    This study aimed at testing the applicability of mannitol salt agar (MSA), a medium generally used in human medicine for differentiating Staphylococcus aureus from coagulase-negative staphylococci (CNS), for culturing bovine-associated CNS species. All test isolates from a comprehensive collection of well-identified CNS species, including both reference strains and field isolates, were able to grow. Subsequently, bulk milk samples and teat apex swabs were used to examine the capability of MSA for yielding CNS under field conditions. Sixty-nine and 47 phenotypically different colonies were retrieved from bulk milk and teat apices, respectively. The majority of isolates from teat apices were staphylococci, whereas in bulk milk, staphylococci formed a minority. After 24h of growth, recovery of separate colonies of CNS was much more convenient on MSA compared to a non-selective blood agar. The results of this study indicate that MSA is a suitable medium for both growth and recovery of bovine-associated CNS.

  17. The Polymyxin Ceftazidime Oxford Medium as an alternative selective and differential medium for isolation of Listeria monocytogenes from raw or unpasteurized food.

    PubMed

    Martínez-Gonzáles, N E; Martínez-Chávez, L; Martínez-Cárdenas, C; Cabrera-Díaz, E; Castillo, A

    2014-04-01

    The Polymyxin Ceftazidime Oxford Medium (PCOM) was developed to recover Listeria monocytogenes from raw or unpasteurized foods. It contains esculin-ferric ammonium citrate as indicator system for Listeria growth, and ceftazidime and polymyxin B as selective agents, which are available in several Latin American countries. Comparison of PCOM, Modified Oxford Medium (MOX) and Tryptic Soy agar with 0.6% yeast extract (TSAYE) indicated that both selective media were equally effective at recovering four individual strains of L. monocytogenes (Scott A, V7, California and broccoli), and a mixture of these strains (LMM) (P > 0.05). The ability of PCOM, MOX, TSAYE and TSAYE supplemented with 4% NaCl to recover heat, acid and freeze-damaged LMM was similar for all media (P > 0.05). The PCOM proved to be effective at isolating colonies of LMM from inoculated raw beef chunks, unpasteurized orange juice, cabbage, and Mexican-style cheese by direct plating and by the US Department of Agriculture's Food Safety and Inspection Service enrichment method. Differentiation of L. monocytogenes colonies was easier on PCOM than on MOX for foods with high levels of background microbiota. Based on the evaluations performed on foods naturally contaminated with L. monocytogenes, PCOM was a more economical alternative than MOX for selective and differential isolation of Listeria from raw or unpasteurized foods.

  18. Collaborative investigation of broth microdilution and semisolid agar dilution for in vitro susceptibility testing of Candida albicans.

    PubMed

    Shawar, R; Paetznick, V; Witte, Z; Ensign, L G; Anaissie, E; LaRocco, M

    1992-08-01

    A study was performed in two laboratories to evaluate the effect of growth medium and test methodology on inter- and intralaboratory variations in the MICs of amphotericin B (AMB), flucytosine (5FC), fluconazole (FLU), itraconazole (ITRA), and the triazole Sch 39304 (SCH) against 14 isolates of Candida albicans. Testing was performed by broth microdilution and semisolid agar dilution with the following media, buffered to pH 7.0 with morpholinepropanesulfonic acid (MOPS): buffered yeast nitrogen base (BYNB), Eagle's minimal essential medium (EMEM), RPMI 1640 medium (RPMI), and synthetic amino acid medium for fungi (SAAMF). Inocula were standardized spectrophotometrically, and endpoints were defined by the complete absence of growth for AMB and by no more than 25% of the growth in the drug-free control for all other agents. Comparative analyses of median MICs, as determined by each test method, were made for all drug-medium combinations. Both methods yielded similar (+/- 1 twofold dilution) median MICs for AMB in EMEM and RPMI, 5FC in all media, and FLU in EMEM, RPMI, and SAAMF. In contrast, substantial between-method variations in median MICs were seen for AMB in BYNB and SAAMF, FLU In BYNB, and ITRA and SCH in all media. Interlaboratory concordance of median MICs was good for AMB, 5FC, and FLU but poor for ITRA and SCH in all media. Endpoint determinations were analyzed by use of kappa statistical analyses for evaluating the strength of observer agreement. Moderate to almost perfect interlaboratory agreement occurred with AMB and 5FC in all media and with FLU in EMEM, RPMI, and SAAMF, irrespective of the test method. Slight to almost perfect interlaboratory agreement occurred with ITRA and SCH in EMEM, RPMI, and SAAMF when tested by semisolid agar dilution but not broth microdilution. Kappa values assessing intralaboratory agreement between methods were high for 5FC in all media, for AMB in BYNB, ENEM, and RPMI, and for FLU in EMEM, RPMI, and SAAMF. One laboratory

  19. Collaborative investigation of broth microdilution and semisolid agar dilution for in vitro susceptibility testing of Candida albicans.

    PubMed Central

    Shawar, R; Paetznick, V; Witte, Z; Ensign, L G; Anaissie, E; LaRocco, M

    1992-01-01

    A study was performed in two laboratories to evaluate the effect of growth medium and test methodology on inter- and intralaboratory variations in the MICs of amphotericin B (AMB), flucytosine (5FC), fluconazole (FLU), itraconazole (ITRA), and the triazole Sch 39304 (SCH) against 14 isolates of Candida albicans. Testing was performed by broth microdilution and semisolid agar dilution with the following media, buffered to pH 7.0 with morpholinepropanesulfonic acid (MOPS): buffered yeast nitrogen base (BYNB), Eagle's minimal essential medium (EMEM), RPMI 1640 medium (RPMI), and synthetic amino acid medium for fungi (SAAMF). Inocula were standardized spectrophotometrically, and endpoints were defined by the complete absence of growth for AMB and by no more than 25% of the growth in the drug-free control for all other agents. Comparative analyses of median MICs, as determined by each test method, were made for all drug-medium combinations. Both methods yielded similar (+/- 1 twofold dilution) median MICs for AMB in EMEM and RPMI, 5FC in all media, and FLU in EMEM, RPMI, and SAAMF. In contrast, substantial between-method variations in median MICs were seen for AMB in BYNB and SAAMF, FLU In BYNB, and ITRA and SCH in all media. Interlaboratory concordance of median MICs was good for AMB, 5FC, and FLU but poor for ITRA and SCH in all media. Endpoint determinations were analyzed by use of kappa statistical analyses for evaluating the strength of observer agreement. Moderate to almost perfect interlaboratory agreement occurred with AMB and 5FC in all media and with FLU in EMEM, RPMI, and SAAMF, irrespective of the test method. Slight to almost perfect interlaboratory agreement occurred with ITRA and SCH in EMEM, RPMI, and SAAMF when tested by semisolid agar dilution but not broth microdilution. Kappa values assessing intralaboratory agreement between methods were high for 5FC in all media, for AMB in BYNB, ENEM, and RPMI, and for FLU in EMEM, RPMI, and SAAMF. One laboratory

  20. Collaborative investigation of broth microdilution and semisolid agar dilution for in vitro susceptibility testing of Candida albicans.

    PubMed

    Shawar, R; Paetznick, V; Witte, Z; Ensign, L G; Anaissie, E; LaRocco, M

    1992-08-01

    A study was performed in two laboratories to evaluate the effect of growth medium and test methodology on inter- and intralaboratory variations in the MICs of amphotericin B (AMB), flucytosine (5FC), fluconazole (FLU), itraconazole (ITRA), and the triazole Sch 39304 (SCH) against 14 isolates of Candida albicans. Testing was performed by broth microdilution and semisolid agar dilution with the following media, buffered to pH 7.0 with morpholinepropanesulfonic acid (MOPS): buffered yeast nitrogen base (BYNB), Eagle's minimal essential medium (EMEM), RPMI 1640 medium (RPMI), and synthetic amino acid medium for fungi (SAAMF). Inocula were standardized spectrophotometrically, and endpoints were defined by the complete absence of growth for AMB and by no more than 25% of the growth in the drug-free control for all other agents. Comparative analyses of median MICs, as determined by each test method, were made for all drug-medium combinations. Both methods yielded similar (+/- 1 twofold dilution) median MICs for AMB in EMEM and RPMI, 5FC in all media, and FLU in EMEM, RPMI, and SAAMF. In contrast, substantial between-method variations in median MICs were seen for AMB in BYNB and SAAMF, FLU In BYNB, and ITRA and SCH in all media. Interlaboratory concordance of median MICs was good for AMB, 5FC, and FLU but poor for ITRA and SCH in all media. Endpoint determinations were analyzed by use of kappa statistical analyses for evaluating the strength of observer agreement. Moderate to almost perfect interlaboratory agreement occurred with AMB and 5FC in all media and with FLU in EMEM, RPMI, and SAAMF, irrespective of the test method. Slight to almost perfect interlaboratory agreement occurred with ITRA and SCH in EMEM, RPMI, and SAAMF when tested by semisolid agar dilution but not broth microdilution. Kappa values assessing intralaboratory agreement between methods were high for 5FC in all media, for AMB in BYNB, ENEM, and RPMI, and for FLU in EMEM, RPMI, and SAAMF. One laboratory

  1. An efficient microbiological growth medium for screening phosphate solubilizing microorganisms.

    PubMed

    Nautiyal, C S

    1999-01-01

    A novel defined microbiological growth medium, National Botanical Research Institute's phosphate growth medium (NBRIP), which is more efficient than Pikovskaya medium (PVK), was developed for screening phosphate solubilizing microorganisms. In plate assay the efficiency of NBRIP was comparable to PVK; however, in broth assay NBRIP consistently demonstrated about 3-fold higher efficiency compared to PVK. The results indicated that the criterion for isolation of phosphate solubilizers based on the formation of visible halo/zone on agar plates is not a reliable technique, as many isolates which did not show any clear zone on agar plates solubilized insoluble inorganic phosphates in liquid medium. It may be concluded that soil microbes should be screened in NBRIP broth assay for the identification of the most efficient phosphate solubilizers. PMID:9919677

  2. Evaluation of Use of a New Chromogenic Agar in Detection of Urinary Tract Pathogens

    PubMed Central

    Samra, Z.; Heifetz, M.; Talmor, J.; Bain, E.; Bahar, J.

    1998-01-01

    CHROMagar Orientation, a new chromogenic medium, was evaluated for the detection and differentiation of gram-positive and gram-negative pathogenic microorganisms in 900 urine samples from hospitalized patients. Performance characteristics of the medium were evaluated in comparison to those of 5% sheep blood and MacConkey agars by direct inoculation of the urine samples on the three media. Four gram-negative and two gram-positive strains as well as one yeast control strain from the American Type Culture Collection were used to ensure quality control. CHROMagar Orientation succeeded in detecting all the urine pathogens that were detected by the reference media, including gram-negative bacilli, staphylococci, streptococci, and yeasts. Colony color and morphology on CHROMagar Orientation accurately differentiated Escherichia coli, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, and Acinetobacter spp. Owing to the similarity in the pigmentation produced by Klebsiella, Enterobacter, and Citrobacter isolates, the medium failed to distinguish among them; however, these isolates were easily recognized as coliforms because of their metallic blue coloration. Staphylococci were clearly perceptible: S. aureus and S. epidermidis grow in regular-size colonies that range from opaque white to yellowish, and S. saprophyticus produces opaque pink colonies. All streptococcus strains, including those from groups B and C, were detected. They grow as undifferentiated flat dry diffused colonies, and additional tests were required for identification. Enterococci were easily discriminated by their strong turquoise pigmentation and their typical growth on the agar’s surface. Yeast grow in typical creamy wet convex colonies. The accuracy of antibiotic susceptibility determinations according to standard methods was also tested by picking isolates directly from CHROMagar Orientation. The results showed excellent correlation with those obtained with microorganisms picked from

  3. Characterization of Leptospiral Chemoreceptors Using a Microscopic Agar Drop Assay.

    PubMed

    Affroze, Samia; Islam, Md Shafiqul; Takabe, Kyosuke; Kudo, Seishi; Nakamura, Shuichi

    2016-08-01

    Bacterial chemotaxis is induced by sensing chemical stimuli via chemoreceptors embedded in the cytoplasmic membrane, enabling the cells to migrate toward nutrients or away from toxins. The chemoreceptors of Escherichia coli and Salmonella spp. have been well studied and are functionally classified on the basis of detectable substrates. The spirochete Leptospira possesses more than ten chemoreceptors and shows attractive or repellent responses against some sugars, amino acids, and fatty acids. However, the roles of these chemoreceptors have not been investigated. In this study, we conducted a chemotaxis assay called microscopic agar drop assay in combination with competition experiments, determining whether two kinds of attractants are recognized by the same type of chemoreceptor in the saprophytic Leptospira strain, Leptospira biflexa. Analyzing the competition effect observed between several pairs of chemicals, we found that L. biflexa senses sugars via chemoreceptors different from those that sense amino acids and fatty acids.

  4. Evaluation of BBL CHROMagar orientation medium for detection and presumptive identification of urinary tract pathogens.

    PubMed Central

    Hengstler, K A; Hammann, R; Fahr, A M

    1997-01-01

    The microbiological performance of BBL CHROMagar Orientation medium and CPS ID2 agar was compared to that of Columbia agar with 5% sheep blood and MacConkey agar without crystal violet for the enumeration and presumptive identification of bacteria responsible for urinary tract infections. Of a total of 658 clinical urine specimens, 118 specimens yielded no growth, 402 specimens yielded growth with cell counts of > or = 10(5) CFU/ml, and 138 specimens yielded growth with cell counts of < 10(5) CFU/ml. Of the specimens with cell counts of > or = 10(5) CFU/ml, 163 were pure cultures and 239 were mixed cultures. A total of 266 Escherichia coli organisms were isolated on both chromogenic media, 260 were isolated on blood agar, and 248 were isolated on MacConkey agar. One strain (0.4%) failed to develop the expected pink color on CHROMagar Orientation medium, and 23 strains (8.7%) failed to develop the expected pink color on CPS ID2 agar. Enterococci (CHROMagar Orientation medium, n = 266; CPS ID2 agar, n = 265) produced small blue-green colonies on both chromogenic media. Fifty of the mixed cultures contained enterococci that were detected only on the chromogenic media. The Klebsiella-Enterobacter-Serratia (KES) and the Proteus-Morganella-Providencia (PMP) groups could be identified on both chromogenic media. Of 66 isolates of the KES group, 63 grew with the expected color on CHROMagar Orientation medium and 58 of 64 isolates grew with the expected color on CPS ID2 agar. Other microorganisms required further identification. The use of chromogenic medium formulations offers a time-saving method for the reliable detection, enumeration, and presumptive identification of urinary tract pathogens. One of the greatest advantages of these media is the easy recognition of mixed cultures. PMID:9350731

  5. Mo-independent nitrogenase 3 is advantageous for diazotrophic growth of Azotobacter vinelandii on solid medium containing molybdenum.

    PubMed

    Maynard, R H; Premakumar, R; Bishop, P E

    1994-09-01

    Competition experiments between wild-type Azotobacter vinelandii and a mutant lacking Mo-independent nitrogenase 3 indicate that nitrogenase 3 provides an advantage during diazotrophic growth on agar media containing 100 to 500 nM Na2MoO4 but not in liquid media under the same conditions. Expression of nitrogenase 3 in wild-type cells growing on agar surfaces was verified with an anfH-lacZ fusion and by detection of nitrogenase 3 subunits. These results show that nitrogenase 3 is important for diazotrophic growth on agar medium at molybdenum concentrations that are not limiting for Mo-dependent diazotrophic growth in liquid medium.

  6. Bacterial pathogens of otitis media and sinusitis: detection in the nasopharynx with selective agar media.

    PubMed

    Dudley, S; Ashe, K; Winther, B; Hendley, J O

    2001-11-01

    Carriage rates for the bacterial pathogens associated with otitis media (Streptococcus pneumoniae [SP], Hemophilus influenzae [HI], and Moraxella catarrhalis [MC]) are of interest. Culture on three selective agars was compared with culture on two standard agars to determine the more accurate method for detection of these species in the nasopharynx of healthy children. Weekly samples were obtained in winter from 18 healthy children (ages 1 through 9 years) as part of a longitudinal study. A 0.1-mL sample of 116 nasopharyngeal aspirate/washes was inoculated onto each of five agars. Two were standard (sheep blood and chocolate), and three were selective (blood with gentamicin for SP; chocolate with vancomycin, bacitracin, and clindamycin for HI; blood with amphotericin B, vancomycin, trimethoprim, and acetazolamide for MC). One technician read the standard plates and another the selective; both were blinded to the results of the other. SP was found in 44% of samples with selective agar versus 25% with standard agar; HI was found in 31% with selective versus 9% with standard; MC was found in 56% with selective versus 37% with standard. Overall, 80% of samples had one or more pathogens detected with selective agars as compared with 58% with standard agars (P =.0004). Selective agars were more accurate than standard agars for detecting otitis pathogens in the nasopharynx, where they are a common part of normal flora in healthy children.

  7. Residual Agar Determination in Bacterial Spores by Electrospray Ionization Mass Spectrometry

    SciTech Connect

    Wahl, Karen L.; Colburn, Heather A.; Wunschel, David S.; Petersen, Catherine E.; Jarman, Kristin H.; Valentine, Nancy B.

    2010-02-15

    Presented here is an analytical method to detect residual agar from a bacterial spore sample as an indication of culturing on an agar plate. This method is based on the resolubilization of agar polysaccharide from a bacterial spore sample, enzymatic digestion, followed by electrospray ionization tandem mass spectrometry (ESI-MSn) analysis for detection of a specific agar fragment ion. A range of Bacillus species and strains were selected to demonstrate the effectiveness of this approach. The characteristic agar fragment ion was detected in the spores grown on agar that were washed from 1 to 5 times, irradiated or non-irradiated and not in the spores grown in broth. A sample containing approximately 108 spores is currently needed for confident detection of residual agar from culture on agar plates in the presence of bacterial spores with a limit of detection of approximately 1 ppm agar spiked into a broth-grown spore sample. The results of a proficiency test with 42 blinded samples are presented demonstrating the utility of this method with no false positives and only 3 false negatives for samples that were below the detection level of the method as documented.

  8. Aerobically incubated medium for decarboxylase testing of Enterobacteriaceae by replica-plating methods.

    PubMed

    Maccani, J E

    1979-12-01

    An aerobically incubated, agar-based medium was developed for amino acid decarboxylase testing of Enterobacteriaceae family members by replica-plating methods. Results with the new medium agreed 97 to 99% with the reference broth method of Moeller, and no false-positive reactions were encountered.

  9. A quasi-universal medium to break the aerobic/anaerobic bacterial culture dichotomy in clinical microbiology.

    PubMed

    Dione, N; Khelaifia, S; La Scola, B; Lagier, J C; Raoult, D

    2016-01-01

    In the mid-19th century, the dichotomy between aerobic and anaerobic bacteria was introduced. Nevertheless, the aerobic growth of strictly anaerobic bacterial species such as Ruminococcus gnavus and Fusobacterium necrophorum, in a culture medium containing antioxidants, was recently demonstrated. We tested aerobically the culture of 623 bacterial strains from 276 bacterial species including 82 strictly anaerobic, 154 facultative anaerobic, 31 aerobic and nine microaerophilic bacterial species as well as ten fungi. The basic culture medium was based on Schaedler agar supplemented with 1 g/L ascorbic acid and 0.1 g/L glutathione (R-medium). We successively optimized this media, adding 0.4 g/L uric acid, using separate autoclaving of the component, or adding haemin 0.1 g/L or α-ketoglutarate 2 g/L. In the basic medium, 237 bacterial species and ten fungal species grew but with no growth of 36 bacterial species, including 22 strict anaerobes. Adding uric acid allowed the growth of 14 further species including eight strict anaerobes, while separate autoclaving allowed the growth of all tested bacterial strains. To extend its potential use for fastidious bacteria, we added haemin for Haemophilus influenzae, Haemophilus parainfluenzae and Eikenella corrodens and α-ketoglutarate for Legionella pneumophila. This medium allowed the growth of all tested strains with the exception of Mycobacterium tuberculosis and Mycobacterium bovis. Testing primoculture and more fastidious species will constitute the main work to be done, but R-medium coupled with a rapid identification method (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) will facilitate the anaerobic culture in clinical microbiology laboratories.

  10. A selective chromogenic agar that distinguishes Bacillus anthracis from Bacillus cereus and Bacillus thuringiensis.

    PubMed

    Juergensmeyer, Margaret A; Gingras, Bruce A; Restaino, Lawrence; Frampton, Elon W

    2006-08-01

    A selective and differential plating medium, R & F anthracis chromogenic agar (ACA), has been developed for isolating and identifying presumptive colonies of Bacillus anthracis. ACA contains the chromogenic substrate 5-bromo-4-chloro-3-indoxyl-choline phosphate that upon hydrolysis yields teal (blue green) colonies indicating the presence of phosphatidylcholine-specific phospholipase C (PC-PLC) activity. Among seven Bacillus species tested on ACA, only members of the Bacillus cereus group (B. anthracis, B. cereus, and B. thuringiensis) produced teal colonies (PC-PLC positive) having cream rings. Examination of colony morphology in 18 pure culture strains of B. anthracis (15 ATCC strains plus AMES-1-RIID, ANR-1, and AMED-RIID), with one exception, required 48 h at 35 to 37 degrees C for significant color production, whereas only 24 h was required for B. cereus and B. thuringiensis. This differential rate of PC-PLC synthesis in B. anthracis (due to the truncated plcR gene and PlcR regulator in B. anthracis) allowed for the rapid differentiation on ACA of presumptive colonies of B. anthracis from B. cereus and B. thuringiensis in both pure and mixed cultures. Effective recovery of B. anthracis from a variety of matrices having both high (soil and sewage) and low microbial backgrounds (cloth, paper, and blood) spiked with B. anthracis ANR-1 spores suggests the probable utility of ACA plating for B. anthracis recovery in a diversity of applications.

  11. Fungistatic activity of flaxseed in potato dextrose agar and a fresh noodle system.

    PubMed

    Xu, Yingying; Hall, Clifford; Wolf-Hall, Charlene; Manthey, Frank

    2008-02-10

    Although numerous researchers have studied flaxseed as a food ingredient for its health benefits, flaxseed (Linum usitatissimum) has never been considered as a food preservative. The objective of this study was to investigate the effect of flaxseed flour (FF) concentration (0, 6, 9, 12, and 15% wt/wt), cultivar ('Omega' and brown) and source (four seed companies located in Minnesota and North Dakota) on flaxseed fungistatic activity. Fungal radial growth was used to assess the fungistatic activity of FF in both potato dextrose agar (PDA) medium and a fresh noodle system. Strains of Penicillium chrysogenum, Aspergillus flavus, Fusarium graminearum, and a Penicillium sp. isolated from molded noodles were used as the test microorganisms. Results showed that growth of F. graminearum was completely inhibited at all FF concentrations in PDA, and the inhibition of the other three test microorganisms increased with increasing FF concentrations. In the model noodle system, FF concentration at 9% or higher significantly reduced the mold count of fresh noodle during storage. In the inoculated noodle system, 6% FF addition was sufficient to significantly inhibit the growth of F. graminearum and A. flavus, whereas 9% FF concentrations showed fungistatic activity against P. chrysogenum and the Penicillium sp. isolate. Differences in the degree of mold inhibition were found among FFs obtained from different sources and cultivars. Results suggested that flaxseed possesses fungistatic activity and could be used as a multifunctional food ingredient.

  12. Differential plating medium for quantitative detection of histamine-producing bacteria.

    PubMed Central

    Niven, C F; Jeffrey, M B; Corlett, D A

    1981-01-01

    A histidine-containing agar medium has been devised for quantitative detection of histamine-producing bacteria that are alleged to be associated with scombroid fish poisoning outbreaks. The responsible bacteria produce a marked pH change in the agar, with attendant color change of pH indicator adjacent to the colonies, thus facilitating their recognition. Proteus morganii and Klebsiella pneumoniae were the two most common histidine-decarboxylating species isolated from scombroid fish and mahi mahi. PMID:7013698

  13. Optimization of modified Middlebrook 7H11 agar for isolation of Mycobacterium bovis from raw milk cheese.

    PubMed

    Forgrave, R; Donaghy, J A; Fisher, A; Rowe, M T

    2014-10-01

    Reports have highlighted the absence of contemporary peer reviewed publications pertaining to Mycobacterium bovis culture from raw milk and cheese. By replicating traditional methods, cheese-making methodology and equipment were devised to produce Cheddar (n = 6) and Caerphilly (n = 3) artificially contaminated with M. bovis (three genotypes) under stringent laboratory-containment guidelines for handling hazardous microbiological material. Middlebrook 7H11, modified for M. bovis isolation, was assessed for capacity to enumerate M. bovis despite changing cheese microflora and prolonged M. bovis exposure to the cheese matrix using maturing cheese test portions (n = 63; up to 16 weeks). Malachite green (MG) containing media isolated M. bovis at significantly (P < 0·05) lower levels than unmodified Middlebrook 7H11 agar despite MG being a common adjunct of Middlebrook 7H11 agar modified for M. bovis growth. Subsequently, a selective MG-free Middlebrook 7H11 agar modified using haemolysed red cells and calf serum was demonstrated as the best performing (P < 0·05) medium for recovery of M. bovis from typical UK cheese types, Cheddar and Caerphilly. Significance and impact of the study: Following increased M. bovis infection of UK cattle, the risk posed to consumers from consumption of unpasteurized milk and dairy products has changed. Furthermore, published methods for the culture and molecular detection of M. bovis in raw milk products are limited. Cheese-making protocols and M. bovis culture media reported here provide tools for further investigation of M. bovis survival during all stages of cheese manufacture and could inform future assessment of the risk to consumers from M. bovis contamination of unpasteurized dairy products.

  14. Optimization of modified Middlebrook 7H11 agar for isolation of Mycobacterium bovis from raw milk cheese.

    PubMed

    Forgrave, R; Donaghy, J A; Fisher, A; Rowe, M T

    2014-10-01

    Reports have highlighted the absence of contemporary peer reviewed publications pertaining to Mycobacterium bovis culture from raw milk and cheese. By replicating traditional methods, cheese-making methodology and equipment were devised to produce Cheddar (n = 6) and Caerphilly (n = 3) artificially contaminated with M. bovis (three genotypes) under stringent laboratory-containment guidelines for handling hazardous microbiological material. Middlebrook 7H11, modified for M. bovis isolation, was assessed for capacity to enumerate M. bovis despite changing cheese microflora and prolonged M. bovis exposure to the cheese matrix using maturing cheese test portions (n = 63; up to 16 weeks). Malachite green (MG) containing media isolated M. bovis at significantly (P < 0·05) lower levels than unmodified Middlebrook 7H11 agar despite MG being a common adjunct of Middlebrook 7H11 agar modified for M. bovis growth. Subsequently, a selective MG-free Middlebrook 7H11 agar modified using haemolysed red cells and calf serum was demonstrated as the best performing (P < 0·05) medium for recovery of M. bovis from typical UK cheese types, Cheddar and Caerphilly. Significance and impact of the study: Following increased M. bovis infection of UK cattle, the risk posed to consumers from consumption of unpasteurized milk and dairy products has changed. Furthermore, published methods for the culture and molecular detection of M. bovis in raw milk products are limited. Cheese-making protocols and M. bovis culture media reported here provide tools for further investigation of M. bovis survival during all stages of cheese manufacture and could inform future assessment of the risk to consumers from M. bovis contamination of unpasteurized dairy products. PMID:24888395

  15. NEW MEDIUM FOR THE SIMULTANEOUS DETECTION OF TOTAL COLIFORMS AND ESCHERICHIA COLI IN WATER (PUBLISHED ERRATUM APPEARS IN APP ENVIRON MICROBIOL 1993 DEC;59(12):4378)

    EPA Science Inventory

    A new membrane filter agar medium (MI agar) containing a chromogen, indoxyl-beta-D-glucuronide, and a fluorogen, 4-methylumbelliferyl-beta-D-galactopyranoside, was developed to simultaneously detect and enumerate Escherichia coli and total coliforms (TC) in water samples on the b...

  16. Calcium supplements

    MedlinePlus

    ... TYPES OF CALCIUM SUPPLEMENTS Forms of calcium include: Calcium carbonate: Over-the-counter (OTC) antacid products, such as Tums and Rolaids, contain calcium carbonate. These sources of calcium do not cost much. ...

  17. Dietary Supplements

    MedlinePlus

    ... are not intended to treat, diagnose, prevent, or cure diseases. Do not take supplements instead of your ... Partners Women's Health Topics Mammography Women and Diabetes HPV, HIV, Birth Control Heart Health for Women Pregnancy ...

  18. Nepali Supplements.

    ERIC Educational Resources Information Center

    Peace Corps, Washington, DC.

    This volume is intended as a supplement to Nepali language instruction. It contains songs, numerals, dialogues in Devanagari script, a Nepali-English, English-Nepali glossary, and an English-Nepali surveyor technical glossary. (AM)

  19. Ceftibuten-containing agar plate for detecting group B streptococci with reduced penicillin susceptibility (PRGBS).

    PubMed

    Kamiya, Chitose; Kimura, Kouji; Doyama, Yo; Miyazaki, Akira; Morimoto, Makiko; Banno, Hirotsugu; Nagano, Noriyuki; Jin, Wanchun; Wachino, Jun-ichi; Yamada, Keiko; Arakawa, Yoshichika

    2015-08-01

    Penicillins remain first-line agents for treatment of group B Streptococcus (Streptococcus agalactiae; GBS) infections; however, several reports have confirmed the existence of GBS with reduced penicillin susceptibility (PRGBS). Because no selective agar plates for detection of PRGBS are available to date, in this investigation, we developed the selective agar plate for detection of PRGBS. We used 19 genetically well-confirmed PRGBS isolates and 38 penicillin-susceptible GBS isolates identified in Japan. For preparation of trial PRGBS-selective agar plates, we added 1 of antimicrobial agents (among oxacillin, ceftizoxime, and ceftibuten) to a well-established GBS-selective agar plate. Among 12 trial PRGBS-selective agar plates, Muller-Hinton agar containing 128 μg/mL ceftibuten with 5% sheep blood, 8 μg/mL gentamicin, and 12 μg/mL nalidixic acid was the most appropriate selective agar for PRGBS, showing 100% sensitivity and 81.6% specificity. In cases of potential nosocomial spread of PRGBS, the selective agar plate could be useful and reliable.

  20. Effect of refrigerated storage on cefaclor in Mueller-Hinton agar.

    PubMed Central

    Surprenant, A M; Preston, D A

    1985-01-01

    Cefaclor is less stable than most cephalosporins in media at 35 degrees C. We demonstrated that the activity of cefaclor in Mueller-Hinton agar diminishes continuously at 4 degrees C, resulting in a loss of two-thirds of the activity within 21 days. We recommend that agar dilution plates for this cephalosporin be prepared on the day of their use. PMID:3968200

  1. Effects of season on the yield and quality of agar from Gracilaria species (Gracilariaceae, Rhodophyta).

    PubMed

    Marinho-Soriano, E; Bourret, E

    2003-12-01

    The effect of season on yield and physical properties of agars extracted from Gracia gracilis and G. bursa-pastoris were determined. The agar yield from G. gracilis was maximum during spring (30%) and minimum during autumn (19%). In G. bursa-pastoris, the agar yield was greatest in summer (36%) and lowest in winter (23%). Agar yield from G. bursa-pastoris was positively correlated with temperature (r=0.94; P<0.01) and salinity (r=0.97; P<0.01) and negatively with nitrogen content (r=-0.93; P<0.01). Agar gel strengths fluctuated from 229 to 828 gcm(-2) and 23 to 168 gcm(-2) for G. gracilis and G. bursa-pastoris, respectively. The gelling temperature showed significant seasonal variation for both species. Chemical analysis of agar from the two seaweeds indicated variation in 3,6-anhydrogalactose and sulfate content (P<0.01). Furthermore, there was an inverse correlation between the two chemical variables. In general, agar extracted from G. gracilis possessed better qualities than agar extracted from G. bursa-pastoris and can be considered a candidate for industrial use.

  2. Characteristics of thermoplastic sugar palm Starch/Agar blend: Thermal, tensile, and physical properties.

    PubMed

    Jumaidin, R; Sapuan, S M; Jawaid, M; Ishak, M R; Sahari, J

    2016-08-01

    The aim of this work is to study the behavior of biodegradable sugar palm starch (SPS) based thermoplastic containing agar in the range of 10-40wt%. The thermoplastics were melt-mixed and then hot pressed at 140°C for 10min. SEM investigation showed good miscibility between SPS and agar. FT-IR analysis confirmed that SPS and agar were compatible and inter-molecular hydrogen bonds existed between them. Incorporation of agar increased the thermoplastic starch tensile properties (Young's modulus and tensile strength). The thermal stability and moisture uptake increased with increasing agar content. The present work shows that starch-based thermoplastics with 30wt% agar content have the highest tensile strength. Higher content of agar (40wt%) resulted to more rough cleavage fracture and slight decrease in the tensile strength. In conclusion, the addition of agar improved the thermal and tensile properties of thermoplastic SPS which widened the potential application of this eco-friendly material. The most promising applications for this eco-friendly material are short-life products such as packaging, container, tray, etc.

  3. Characteristics of thermoplastic sugar palm Starch/Agar blend: Thermal, tensile, and physical properties.

    PubMed

    Jumaidin, R; Sapuan, S M; Jawaid, M; Ishak, M R; Sahari, J

    2016-08-01

    The aim of this work is to study the behavior of biodegradable sugar palm starch (SPS) based thermoplastic containing agar in the range of 10-40wt%. The thermoplastics were melt-mixed and then hot pressed at 140°C for 10min. SEM investigation showed good miscibility between SPS and agar. FT-IR analysis confirmed that SPS and agar were compatible and inter-molecular hydrogen bonds existed between them. Incorporation of agar increased the thermoplastic starch tensile properties (Young's modulus and tensile strength). The thermal stability and moisture uptake increased with increasing agar content. The present work shows that starch-based thermoplastics with 30wt% agar content have the highest tensile strength. Higher content of agar (40wt%) resulted to more rough cleavage fracture and slight decrease in the tensile strength. In conclusion, the addition of agar improved the thermal and tensile properties of thermoplastic SPS which widened the potential application of this eco-friendly material. The most promising applications for this eco-friendly material are short-life products such as packaging, container, tray, etc. PMID:27177458

  4. Electrospinning of agar/PVA aqueous solutions and its relation with rheological properties.

    PubMed

    Sousa, Ana M M; Souza, Hiléia K S; Uknalis, Joseph; Liu, Shih-Chuan; Gonçalves, Maria P; Liu, LinShu

    2015-01-22

    In this work, we report the successful fabrication of agar-based nanofibers by electrospinning technique, using water as solvent media. A tubeless spinneret was attached inside the electrospinning chamber, operating at 50°C, to avoid agar gelation. Agar pure solution (1 wt%) showed inadequate spinnability regardless of the used electrospinning conditions. The addition of a co-blending polymer such as PVA (10 wt% starting solution) improved the solutions viscoelasticity and hence, the solutions spinnability. Agar/PVA solutions were prepared with different mass ratios (100/0, 50/50, 40/60, 30/70, 20/80 and 0/100) and electrospun at various sets of electrospinning conditions. Best nanofibers were obtained with 30/70 and 20/80 agar/PVA blends while samples with higher agar contents (50/50 and 40/60 agar/PVA) were harder to process and led to discontinuous fibrous mats. This first set of encouraging results can open a new window of opportunities for agar-based biomaterials in the form of nanofibers.

  5. Efficacy of agar-plate culture in detection of Strongyloides stercoralis infection.

    PubMed

    Arakaki, T; Iwanaga, M; Kinjo, F; Saito, A; Asato, R; Ikeshiro, T

    1990-06-01

    Agar-plate culture of feces using a modified petri dish proved to be highly efficient in the detection of Strongyloides stercoralis infection. Furrows left by S. stercoralis on the agar plate were distinguished readily in size from those left by Necator americanus. PMID:2352073

  6. An extension of the Coconut Cream Agar method to screen Penicillium citrinum isolates for citrinin production.

    PubMed

    Mohamed, S; Flint, S; Palmer, J; Fletcher, G C; Pitt, J I

    2013-09-01

    A simple and rapid screening method was developed for the detection of citrinin in fungal cultures using Coconut Cream Agar (CCA) described previously for detecting aflatoxin and ochratoxin A. Fifteen isolates of Penicillium citrinum were inoculated onto CCA and incubated at 25 and 30°C for 10 days. All isolates produced a distinct yellow green fluorescence on CCA when the reverse side of the agar plates were viewed under long wavelength UV light. Detection was optimal at 25°C after four to 5 days of incubation. Isolates positive by the CCA method also tested positive for citrinin production by the TLC agar plug method after growth on CCA, Czapek yeast extract agar and yeast extract sucrose agar. Control cultures were negative by both methods, indicating that the CCA Petri dish method was suitable for screening cultures for citrinin production.

  7. Development of a Novel Selective and Differential Medium for the Isolation of Listeria monocytogenes

    PubMed Central

    Park, Sang-Hyun; Chang, Pahn-Shick; Ryu, Sangryeol

    2014-01-01

    A new medium (lecithin and levofloxacin [LL] medium) is described for the isolation of Listeria monocytogenes from food samples. LL medium includes lecithin from soybeans for the detection of phosphatidylinositol-specific phospholipase C (PI-PLC) and phosphatidylcholine-specific phospholipase C (PC-PLC) produced by L. monocytogenes. Levofloxacin is incorporated to inhibit the growth of microorganisms other than L. monocytogenes, especially Bacillus cereus, shown to possess PI-PLC and PC-PLC activities. L. monocyogenes produced white colonies with a halo on LL medium, whereas Listeria innocua appeared as white colonies without a halo. Levofloxacin at 0.20 mg/liter completely inhibited the growth of B. cereus, while the growth of L. monocytogenes was unaffected. In the second phase of the study, the sensitivity and the specificity of LL medium were compared to those of modified Oxford agar (MOX) and two chromogenic media (Brilliance Listeria agar and CHROMagar Listeria), using a total of 250 food samples. From 200 unspiked food samples, the specificity of LL medium (96.0%) was superior to that of MOX (72.0%) and similar to the specificities of Brilliance Listeria agar (96.5%) and CHROMagar Listeria (94.5%). From 50 spiked food samples, LL medium and CHROMagar Listeria represented the highest sensitivities (96.0%), followed by Brilliance Listeria agar (92.0%) and MOX (54.0%). Also, LL medium showed the highest confirmation rate (98.8%), followed by Brilliance Listeria agar (98.7%), CHROMagar Listeria (98.3%), and MOX (52.0%). On the basis of its good specificity and cost effectiveness, LL medium is useful for the isolation of L. monocytogenes from food samples. PMID:24271177

  8. Growth of purified astrocytes in a chemically defined medium

    SciTech Connect

    Morrison, R.S.; De Vellis, J.

    1981-11-01

    Astrocytes purified from primary cultures of neonatal rat cerebrum can not be grown in a synthetic medium supplemented with putrescine, prostaglandin F/sub 2//sub ..cap alpha../, insulin, fibroblast growth factor, and hydrocortisone. These five supplements have a marked synergistic effect on growth when used in combination but have little effect when used individually. Astrocytes grown in the defined medium exhibit dramatic changes in morphological characteristics in comparison to cells grown in serum-free or serum-supplemented medium. In addition, these cells express the astrocyte-specific marker glial fibrillary acidic protein and are estimated by several criteria to be greater than 95% astrocytes.

  9. Evaluation of Granada agar plate for detection of Streptococcus agalactiae in urine specimens from pregnant women.

    PubMed

    Tamayo, Javier; Gómez-Garcés, José-Luis; Alós, Juan-Ignacio

    2004-08-01

    The Granada agar plate (GAP; Biomedics SL, Madrid, Spain) was evaluated for the detection of group B streptococci (GBS) in urine specimens from pregnant women submitted for testing for asymptomatic bacteriuria and was compared with blood agar (BA [Columbia agar with 5% sheep blood]; bioMérieux, Marcy l'Etoile, France). The GAP detected 103 out of 105 GBS, whereas BA detected only 50. Use of the GAP could be a good method for the detection of GBS in urine specimens from pregnant women. PMID:15297542

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

    PubMed Central

    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. PMID:26355542

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

    PubMed

    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.

  12. Xanthan gum: an economical substitute for agar in plant tissue culture media.

    PubMed

    Jain, R; Babbar, S B

    2006-03-01

    Xanthan gum, a microbial desiccation-resistant polysaccharide prepared commercially by aerobic submerged fermentation from Xanthomonas campestris, has been successfully used as a solidifying agent for plant tissue culture media. Its suitability as a substitute to agar was demonstrated for in vitro seed germination, caulogenesis and rhizogenesis of Albizzia lebbeck, androgenesis in anther cultures of Datura innoxia, and somatic embryogenesis in callus cultures of Calliandra tweedii. Culture media used for eliciting these morphogenic responses were gelled with either 1% xanthan gum or 0.9% agar. Xanthan gum, like agar, supported all these responses.

  13. Polymer film deposition on agar using a dielectric barrier discharge jet and its bacterial growth inhibition

    NASA Astrophysics Data System (ADS)

    Tsai, T.-C.; Cho, J.; Mcintyre, K.; Jo, Y.-K.; Staack, D.

    2012-08-01

    Polymer film deposition on agar in ambient air was achieved using the helium dielectric barrier discharge jet (DBD jet) fed with polymer precursors, and the bacterial growth inhibition due to the deposited film was observed. The DBD jet with precursor addition was more efficient at sterilization than a helium-only DBD jet. On the areas where polymer films cover the agar the bacterial growth was significantly inhibited. The inhibition efficacy showed dependence on the film thickness. The DBD jet without precursor also created a modified agar layer, which may slow the growth of some bacterial strains.

  14. Glutamine supplementation.

    PubMed

    Wernerman, Jan

    2011-07-18

    Intravenous glutamine supplementation is standard care when parenteral nutrition is given for critical illness. There are data of a reduced mortality when glutamine supplementation is given. In addition, standard commercial products for parenteral nutrition do not contain any glutamine due to glutamine instability in aqueous solutions. For the majority of critical ill patients who are fed enterally, the available evidence is insufficient to recommend glutamine supplementation. Standard formulation of enteral nutrition contains some glutamine: 2-4 g/L. However, this dose is insufficient to normalize glutamine plasma concentration.Plasma concentration of glutamine is low in many patients with critical illness and a low level is an independent risk factor for mortality. A low plasma glutamine concentration is the best indicator of glutamine depletion. Data are emerging about how the endogenous production of glutamine is regulated. We know that skeletal muscle is the major producer of glutamine and that a part of the profound depletion of skeletal muscle seen in critical illness is a reflection of the need to produce glutamine.Glutamine is utilized in rapidly dividing cells in the splanchnic area. Quantitatively most glutamine is oxidized, but the availability of glutamine in surplus is important for the de novo synthesis of nucleotides and necessary for cell division and protein synthesis. More knowledge about the regulation of the endogenous production of glutamine is needed to outline better guidelines for glutamine supplementation in the future.

  15. Sports Supplements

    MedlinePlus

    ... specialist. The doc will be able to offer alternatives to supplements based on your body and sport. Reviewed by: Mary L. Gavin, MD Date reviewed: January 2015 previous 1 • 2 • 3 For Teens For Kids For Parents MORE ON THIS TOPIC Sports Center Energy Drinks and Food Bars: Power or Hype? A ...

  16. Growth characteristics of Bacillus anthracis compared to other Bacillus spp. on the selective nutrient media Anthrax Blood Agar and Cereus Ident Agar.

    PubMed

    Tomaso, Herbert; Bartling, Carsten; Al Dahouk, Sascha; Hagen, Ralf M; Scholz, Holger C; Beyer, Wolfgang; Neubauer, Heinrich

    2006-01-01

    Anthrax Blood Agar (ABA) and Cereus Ident Agar (CEI) were evaluated as selective growth media for the isolation of Bacillus anthracis using 92 B. anthracis and 132 other Bacillus strains from 30 species. The positive predictive values for the identification of B. anthracis on ABA, CEI, and the combination of both were 72%, 71%, and 90%, respectively. Thus, less than 10% of all species were misidentified using both nutrient media. Species which might be misidentified as B. anthracis were B. cereus, B. mycoides, and B. thuringiensis. Particularly, 30% of B. weihenstephanensis strains were misidentified as B. anthracis.

  17. Metronidazole and clarithromycin resistance in Helicobacter pylori determined by measuring MICs of antimicrobial agents in color indicator egg yolk agar in a miniwell format. The Gastrointestinal Physiology Working Group of Universidad Peruana Cayetano Heredia and the Johns Hopkins University.

    PubMed

    Vasquez, A; Valdez, Y; Gilman, R H; McDonald, J J; Westblom, T U; Berg, D; Mayta, H; Gutierrez, V

    1996-05-01

    Resistance of Helicobacter pylori to metronidazole often causes failure of commonly used combination drug treatment regimens. We determined the MICs of metronidazole and clarithromycin against 18 H. pylori strains from Peru using tetrazolium egg yolk (TEY) agar. The MIC results obtained by agar dilution with petri dishes were compared with the results found through a miniwell format. The results of the two protocols for measuring drug susceptibility differed by no more than 1 dilution in all cases. On TEY agar, bright-red H. pylori colonies were easy to identify against a yellow background. Sixty-one percent (11 of 18) of the strains were resistant to metronidazole (MIC, > or = 4 micrograms/ml) and 50% (9 of 18) were resistant to clarithromycin (MIC, > or = 0.125 micrograms/ml), whereas none (0 of 5) of the strains tested were resistant to tetracycline (MIC, > or = 1 micrograms/ml). Thus, the prevalence of metronidazole and clarithromycin resistance in Peru is higher than that in developed regions of the world. The miniwell plate with TEY agar allows easy H. pylori colony identification, requires about one-third less of the costly medium necessary for petri dish assaying, conserves space, and yields MICs equivalent to those with agar dilution in petri dishes.

  18. Selective medium for isolation of Xanthomonas maltophilia from soil and rhizosphere environments.

    PubMed

    Juhnke, M E; des Jardin, E

    1989-03-01

    A selective medium (XMSM) was developed for isolation of Xanthomonas maltophilia from bulk soil and plant rhizosphere environments. The XMSM basal medium contained maltose, tryptone, bromthymol blue, and agar. Antibiotics added to select for X. maltophilia were cycloheximide, nystatin, cephalexin, bacitracin, penicillin G, novobiocin, neomycin sulfate, and tobramycin. A comparison was made between XMSM and 1/10-strength tryptic soy broth agar for recovery of X. maltophilia from sterile and nonsterile soil infested with known X. maltophilia isolates. A recovery rate of 97% or greater for XMSM was demonstrated. XMSM was used to isolate X. maltophilia from a variety of soil and rhizosphere environments. PMID:2930173

  19. Detection of intermediately vancomycin-susceptible and heterogeneous Staphylococcus aureus isolates: comparison of Etest and Agar screening methods.

    PubMed

    Riederer, K; Shemes, S; Chase, P; Musta, A; Mar, A; Khatib, R

    2011-06-01

    Detection of Staphylococcus aureus isolates with intermediate vancomycin susceptibility (VISA) and heteroresistance (hVISA) remains problematic. The population analysis profile/area under the curve (PAP/AUC) is the gold standard but is cumbersome. We compared the performance of two Etest screening methods (macromethod [MAC] and glycopeptide resistance detection [GRD]) plus brain heart infusion (BHI) agars supplemented with 3 (BHI-V3) or 4 (BHI-V4) mg/liter vancomycin in detecting hVISA and/or VISA phenotypes. Etest hVISA screenings were done in parallel for 485 saved methicillin-resistant S. aureus (MRSA) blood isolates according to the manufacturer's instructions. The PAP/AUC was measured for all isolates according to the modified method. PAP/AUC test isolate/Mu3 ratios of <0.9, 0.9 to 1.3, and >1.3 were considered positive for susceptible MRSA (S-MRSA), hVISA, and VISA, respectively. PAP/AUC revealed seven VISA and 33 hVISA phenotypes. MAC screening was positive for 30 (75.0%) hVISA/VISA and 49 (11.0%) S-MRSA isolates. GRD screening was positive for 28 (70.0%) hVISA/VISA and 63 (14.2%) S-MRSA isolates. Growth on BHI-V3 was noted in all hVISA/VISA and 24 (5.4%) S-MRSA isolates. Growth on BHI-V4 was noted in all VISA and four (12.1%) hVISA isolates. None of the S-MRSA isolates grew on BHI-V4 agar. The sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values were 75.0%, 89.0%, 38.0%, and 97.5% for MAC; 70.0%, 85.8%, 30.8%, and 97.0% for GRD; 100%, 94.6%, 62.5%, and 100% for BHI-V3; and 100, 99.2%, 63.6%, and 100% for BHI-V4 (for detecting VISA). These findings suggest that both Etest screening methods have excellent NPV, but positive results require confirmation. BHI-V3 and BHI-V4 agars provide more precise identification of hVISA and VISA, respectively; they may be reasonable alternatives to PAP/AUC.

  20. Root architecture and morphometric analysis of Arabidopsis thaliana grown in Cd/Cu/Zn-gradient agar dishes: A new screening technique for studying plant response to metals.

    PubMed

    Bochicchio, Rocco; Sofo, Adriano; Terzano, Roberto; Gattullo, Concetta Eliana; Amato, Mariana; Scopa, Antonio

    2015-06-01

    A new screening strategy using Petri dishes with a gradient of distances between germinating seeds and a metal-contaminated medium was used for studying alterations in root architecture and morphology of Arabidopsis thaliana treated with cadmium, copper and zinc at sub-toxic concentrations. Metal concentrations in the dishes were determined by anodic stripping voltammetry on digested agar samples collected along the gradient, and kriging statistical interpolation method was performed. After two weeks, all agar dishes were scanned at high resolution and the root systems analyzed. In the presence of all the three metals, primary root length did not significantly change compared to controls, excepting for zinc applied alone (+45% of controls). In metal-treated seedlings, root system total length increased due to the higher number of lateral roots. The seedlings closer to the agar sectors including metals showed a marked curvature and a higher root branching in comparison to those further away from the metals. This behavior, together with an observed increase in root diameter in metal-treated seedlings could be interpreted as compensatory growth, and a thicker roots could act as a barrier to protect root from the metals. We therefore propose that the remodeling of the root architecture in response to metals could be a pollution 'escaping strategy' aimed at seeking metal-free patches.

  1. Neonothopanus gardneri: a new combination for a bioluminescent agaric from Brazil.

    PubMed

    Capelari, Marina; Desjardin, Dennis E; Perry, Brian A; Asai, Tatiane; Stevani, Cassius V

    2011-01-01

    The bioluminescent agaric, Agaricus gardneri Berk., was rediscovered recently in central Brazil. The new combination, Neonothopanus gardneri, is proposed for this long-forgotten taxon supported by morphological and molecular data.

  2. A fresh liver agar substrate for rearing small numbers of forensically important blow flies (Diptera: Calliphoridae)

    USGS Publications Warehouse

    Gruner, Susan V.; Slone, Daniel H.

    2014-01-01

    Forensically important calliphorids can be reared on a mixture of beef liver and agar. Small pieces of meat, especially fresh or frozen beef liver, will desiccate in 2–6 h, but this simple-to-make feeding substrate remains moist for at least 12 h at 25 and 30°C without desiccation, even in small (5 g) amounts. We determined the survivorship of small numbers of Chrysomya megacephala (F.) (first-instar larvae to adult eclosion) raised on 5 g of liver agar and fresh beef liver. We found that all larvae raised on 5 g of liver died due to desiccation, but survivorship on 5 g of liver agar was equivalent to that on larger (50 g) pieces of either liver agar or beef liver.

  3. [THE APPLICATION OF SELECTIVE CHROMOGENIC AGAR FOR DETECTING ENTEROBACTERIA WITH PRODUCTION OF BETA-LACTAMASES].

    PubMed

    Korobova, A G; Frolova, L N; Kliasova, G A

    2015-11-01

    The detection of enterobacteria with production of beta-lactamases of extended spectrum in selective chromogenic agar was analyzed The results ofdetection of beta-lactamases of extended spectrum was compared with "double disc" technique. The smears from mucous membrane of guttur and rectum from patients were analyzed in parallel on solid growth agar (Endo or Mac Conkey) and on selective agar CHROMagartm ESBL (CHROMagar France). The production of beta-lactamases of extended spectrum was confirmed using "double discs" technique. To exclude hyper-production of ampC beta-lactamases E-test was applied containing cefotetan and cefotetan with cloxacillin. The sampling consisted of 1552 samples from patients. The study permitted to isolate 1243 strains of enterobacteria on agar Endo or Mac Conkey and 409 strains of enterobacteria on selective agar CHROMagartm ESBL (Escherichia coli n = 226, Klebsiella pneumoniae n = 105, enterobacter spp. n = 35, Citrobacter spp. n = 21, others n = 22). The application of "double discs" technique confirmed production of beta-lactamases of extended spectrum in 386 (94%) out of 409 strains isolated on agar CHROMagartm ESBL. In 23 (6%) of strains no confirmation was established and hyper-production of ampC of beta-lactamases was established 15 out of total. Additionally, 8 were sensitive to cephalosporin of third generation. All enterobacteria isolated on agar Endo or Mac Conkey also were tested by "double discs" technique. Overall, 394 strains of enterobacteria with production of beta-lactamases of extended spectrum were obtained. On all agars (agar Endo or Mac Conkey and CHROMagartm ESBL)--263 (67%) strains; only on CHROMagartm ESBL--123 (31%) and only on agar Endo or Mac Conkey--8 (2%) (p < 0.0001). The sensitivity of selective agar CHROMagartm ESBL made up to 98% and specificity--97%. The resolution about detection of enterobacteria producing beta-lactamases of extended spectrum were submitted to clinic in 18-24 hours after arrival

  4. [THE APPLICATION OF SELECTIVE CHROMOGENIC AGAR FOR DETECTING ENTEROBACTERIA WITH PRODUCTION OF BETA-LACTAMASES].

    PubMed

    Korobova, A G; Frolova, L N; Kliasova, G A

    2015-11-01

    The detection of enterobacteria with production of beta-lactamases of extended spectrum in selective chromogenic agar was analyzed The results ofdetection of beta-lactamases of extended spectrum was compared with "double disc" technique. The smears from mucous membrane of guttur and rectum from patients were analyzed in parallel on solid growth agar (Endo or Mac Conkey) and on selective agar CHROMagartm ESBL (CHROMagar France). The production of beta-lactamases of extended spectrum was confirmed using "double discs" technique. To exclude hyper-production of ampC beta-lactamases E-test was applied containing cefotetan and cefotetan with cloxacillin. The sampling consisted of 1552 samples from patients. The study permitted to isolate 1243 strains of enterobacteria on agar Endo or Mac Conkey and 409 strains of enterobacteria on selective agar CHROMagartm ESBL (Escherichia coli n = 226, Klebsiella pneumoniae n = 105, enterobacter spp. n = 35, Citrobacter spp. n = 21, others n = 22). The application of "double discs" technique confirmed production of beta-lactamases of extended spectrum in 386 (94%) out of 409 strains isolated on agar CHROMagartm ESBL. In 23 (6%) of strains no confirmation was established and hyper-production of ampC of beta-lactamases was established 15 out of total. Additionally, 8 were sensitive to cephalosporin of third generation. All enterobacteria isolated on agar Endo or Mac Conkey also were tested by "double discs" technique. Overall, 394 strains of enterobacteria with production of beta-lactamases of extended spectrum were obtained. On all agars (agar Endo or Mac Conkey and CHROMagartm ESBL)--263 (67%) strains; only on CHROMagartm ESBL--123 (31%) and only on agar Endo or Mac Conkey--8 (2%) (p < 0.0001). The sensitivity of selective agar CHROMagartm ESBL made up to 98% and specificity--97%. The resolution about detection of enterobacteria producing beta-lactamases of extended spectrum were submitted to clinic in 18-24 hours after arrival

  5. A combined approach for the enhanced detection and isolation of Bartonella species in dog blood samples: pre-enrichment liquid culture followed by PCR and subculture onto agar plates.

    PubMed

    Duncan, Ashlee W; Maggi, Ricardo G; Breitschwerdt, Edward B

    2007-05-01

    Historically, direct plating, lysis centrifugation, or freeze-thaw approaches have proven to be highly insensitive methods for confirming Bartonella species infection in dogs. A prospective study was designed to compare diagnostic methods for the detection of Bartonella using samples submitted to the Vector-Borne Disease Diagnostic Laboratory at North Carolina State University. Methods included indirect immunofluorescence assay, PCR, direct inoculation of a blood agar plate (trypticase soy agar with 5% rabbit blood), and inoculation into a novel pre-enrichment liquid medium, Bartonella/alpha-Proteobacteria growth medium (BAPGM). Sequential research efforts resulted in the development of a combinational approach consisting of pre-enrichment culture of Bartonella species in BAPGM, sub-inoculation of the liquid culture onto agar plates, followed by DNA amplification using PCR. The multi-faceted approach resulted in substantial improvement in the microbiological detection and isolation of Bartonella when compared to direct inoculation of a blood agar plate. Importantly, this approach facilitated the detection and subsequent isolation of both single and co-infections with two Bartonella species in the blood of naturally infected dogs. The use of a combinational approach of pre-enrichment culture and PCR may assist in the diagnostic confirmation of bartonellosis in dogs and other animals.

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

    SciTech Connect

    McNamara, W.F.; Aubert, J.H.

    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.

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

    PubMed Central

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

    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. PMID:23209220

  8. Evaluation of the Oxoid Brilliance™ CRE Agar for the detection of carbapenemase-producing Enterobacteriaceae.

    PubMed

    Cohen Stuart, J; Voets, G; Rottier, W; Voskuil, S; Scharringa, J; Van Dijk, K; Fluit, A C; Leverstein-Van Hall, M

    2013-11-01

    The adequate detection of carbapenemase-producing Enterobacteriaceae (CPE) is essential for adequate antibiotic therapy and for infection control purposes, especially in an outbreak setting. Selective agars play an important role in the detection of CPE. The Oxoid Brilliance™ CRE Agar (Thermo Fisher Scientific) was evaluated for the detection of CPE using 255 non-repetitive Enterobacteriaceae isolates, including 95 CPE (36 KPC, 4 KPC plus VIM, 4 NDM, 6 GIM, 20 VIM, and 25 OXA-48-producing isolates). The sensitivity of the CRE agar for the detection of CPE was 94 % (89/95), but differed per carbapenemase gene (100 % for KPC, NDM, and GIM, 90 % for VIM, and 84 % for OXA-48-producing isolates). The specificity of the CRE agar was 71 %, due to the growth of AmpC- and/or ESBL-producing isolates. The CRE agar is a sensitive tool for the detection of KPC and metallo-carbapenemase-producing Enterobacteriaceae, although the detection of OXA-48 producers is less optimal. The relatively low specificity requires confirmation of carbapenemase production for isolates recovered from the CRE agar.

  9. Entrapment of α-Amylase in Agar Beads for Biocatalysis of Macromolecular Substrate

    PubMed Central

    Sharma, Manu; Sharma, Vinay; Majumdar, Dipak K.

    2014-01-01

    Attempts have been made to optimize immobilization parameters, catalytic property, and stability of immobilized α-amylase in agar. The work compares natural entrapment efficiency of agar with the ionotropically cross-linked agar hydrogel, with the advantage of easy scale-up and cost and time effectiveness. Beads prepared with 3% (w/v) agar and 75 mM calcium chloride and hardened for 20 minutes were selected for further studies on the basis of entrapment efficiency (80%) and physical stability. Following entrapment, pH and temperature optima of enzyme were shifted from 6 to 6.5 and 50 to 55°C, respectively. Michaelis constant (Km) for both free and entrapped enzymes remained the same (0.83%) suggesting no change in substrate affinity. However, Vmax⁡ of entrapped enzyme decreased ~37.5-fold. The midpoint of thermal inactivation for entrapped enzyme increased by 8 ± 1°C implying its higher thermal stability. The entrapped enzyme in calcium agar bead had an Ea value of 27.49 kcal/mol compared to 17.6 kcal/mol for free enzyme indicating increased stability on entrapment. Half-life of enzyme increased ~2.2 times after entrapment in calcium agar at 60°C indicating stabilization of enzyme. The reusability of beads was size dependent. Beads with diameter <710 μm were stable and could be reused for 6 cycles with ~22% loss in activity. PMID:27382608

  10. Complex impedance and conductivity of agar-based ion-conducting polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Nwanya, A. C.; Amaechi, C. I.; Udounwa, A. E.; Osuji, R. U.; Maaza, M.; Ezema, F. I.

    2015-04-01

    Agar-based electrolyte standing films with different salts and weak acids as ion and proton conductors were prepared and characterized by X-ray diffraction, UV-visible spectrophotometry, photoluminescence emission spectroscopy and electrochemical impedance spectroscopy. The salts used are lithium perchlorate (LiClO4) and potassium perchlorate (KClO4), while the weak acids used are acetic acid (CH3COOH) and lactic acid (C3H6O3). The values of the ion conductivity obtained for the agar-based polymer films are 6.54 × 10-8, 9.12 × 10-8, 3.53 × 10-8, 2.24 × 10-8 S/cm for the agar/acetic acid, agar/lactic acid, agar/LiClO4 and agar/KClO4 polymer films, respectively. As a function of temperature, the ion conductivity exhibits an Arrhenius behavior and the estimated activation energy is ≈0.1 eV for all the samples. The samples depicted high values of dielectric permittivity toward low frequencies which is due mostly to electrode polarization effect. The samples showed very high transparency (85-98 %) in the visible region, and this high transparency is one of the major requirements for application in electrochromic devices (ECD). The values of conductivity and activation energy obtained indicate that the electrolytes are good materials for application in ECD.

  11. [GROWTH OF MICROMYCETES FROM DIFFERENT ECOLOGICAL NICHES ON AGAR NUTRIENT MEDIA].

    PubMed

    Kurchenko, I M; Yurieva, E M; Voychuk, S I

    2015-01-01

    Radial growth rate of (K(r)) 153 strains 6 species of micromycetes from different ecological niches was studied on 7 agar media: three standard (malt extract agar, potato-dextrose agar, Czapek's agar), and on agar media with plant polymers (carboxymethylcellulose, xylan, soluble starch and apple pectin). Endophytic and plant pathogenic strains (biotrophs) of all studied species did not differ significantly in their ability to grow on nutrient media of different composition--average values of K(r) for these two groups were the same (0,200 and 0,199 mm/h, respectively). Soil micromycetes (saprophytes) characterized by the lowest average growth rate (0,169 mm/h) and significantly differed from the endophytic and plant pathogenic ones. Average of the radial growth rates of studied microscopic fungi were higher on standard nutrient media than with plant polymers ones. Growth parameters of endophytes and plant pathogens of all studied species on various agar media differed from the soil strains. High growth rate of endophytic and plant pathogenic strains of Fusarium poae, Alternaria alternata and Ceratocystis sp. provides them the rapid colonization of plants. Penicillium funiculosum strains equally can exist as saprophytes in soil and as endophytic plant symbionts. A wide range of K(r) variation of endophytic dark pigmented Mycelia sterilia indicates the presence in this group of different species of micromycetes, which have no sporulation.

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

    PubMed

    Varettas, Kerry

    2013-12-01

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

  13. Influence of organic supplements on production of shoot and callus biomass and accumulation of bacoside in Bacopa monniera (L.) Pennell.

    PubMed

    Parale, Anuradha; Barmukh, Rajkumar; Nikam, Tukaram

    2010-04-01

    Production of valuable secondary metabolites through plant cell or organ culture is the best suited alternative to extraction of whole plant material and to increase production of secondary metabolites in in-vitro systems, feeding precursor or intermediate metabolites is an obvious and popular approach. The present investigation was aimed to study the influence of feeding of organic supplements, glycine (0-125 μM), ferulic acid (0-200 μM), phenylalanine (0-200 μM), α-ketoglutaric acid (0-200 μM) and pyruvic acid (0-200 μM) on production of bacoside-A (a triterpenoid type secondary metabolite responsible for cognition effects) in shoot and callus biomass of Bacopa monniera (L.) Pennell. The shoots were raised in liquid Murashige and Skoog's (MS) medium fortified with 5 μM 6-benzyladenine (BA) and callus biomass on agar solidified MS medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4 -D) in conjunction with 5 μM 1-napthaleneacetic acid (NAA). Among the organic supplements used, 100 μM pyruvic acid effectively enhanced the production of bacoside-A in shoot as well as callus biomass. The bacoside-A content in in-vitro raised shoot biomass was 4.0 and 1.2 times higher as compared to control and shoot biomass of naturally grown plants respectively. Inclusion of pyruvic acid in MS medium for in-vitro shoot cultures of B. monniera, can be adapted for enhanced production of bacoside-A.

  14. Chiral response of Oryzeae and Paniceae plants in alpha-methylbenzyl-3-p-tolyl urea agar medium.

    PubMed

    Omokawa, Hiroyoshi; Murata, Hiroshi; Kobayashi, Shoko

    2004-01-01

    The results presented here support the hypothesis that plants of the tribe Oryzeae respond enantioselectively and homogeneously to optically active 1-alpha-methylbenzyl-3-p-tolylurea (MBTU) in root growth inhibition, in contrast to Echinochloa species. The Oryzeae plants tested in this study belong to different genera (Oryza, Leersia, Chikusichloa and Zizania), to different species (O sativa, O glaberrima, O alta, O coarctata, O latifolia, O minuta, O rufipogon), to various ecospecies of Oryza (japonica, indica, japonica x indica, javanica) and to different levels of evolution [cultivated rice (O sativa and O glaberrima) and ancestral wild rice species]. In spite of their different phylogenic status and diverse sensitivity, the root growth of all members of the genus Oryza was inhibited more by R-MBTU than by S-MBTU. Zizania palustris, Z latifolia, Leersia oryzoides and Chikusichloa aquatica belonging to the tribe Oryzeae exhibited similar chiral recognition to the Oryza plants, suggesting that Oryzeae have a common chiral recognition mechanism in their response to optically active MBTUs. In contrast, Echinochloa plants (E crus-galli (L) Beauv var crus-galli and E colonum (L) Link), belonging into subfamily Panicoideae tribe Paniceae, responded in a different way, where their root growth was more sensitive to S-MBTU than to the antipodal R-MBTU. A reverse chiral response between the tribe Oryzeae and the genus Echinochloa was clearly indicated in this study. This diverse response may be relevant to Gramineae classification. PMID:14727742

  15. The growth of paracoccus halodenitrificans in a defined medium

    NASA Technical Reports Server (NTRS)

    Hochstein, L. I.; Tomlinson, G. A.

    1983-01-01

    A synthetic medium, consisting of inorganic salts and any of a number of carbon sources, supported the aerobic growth of Paracoccus halodenitrificans when supplemented with thiamine. The same medium plus a nitrogenous oxide supported anaerobic growth when additionally supplemented with methionine. The observation that vitamin B12 or betaine replaced methionine suggested that P. halodenitrificans had a defect in the cobalamin dependent pathway for methionine biosynthesis, as well as the inability to synthesize betaine when growing anaerobically.

  16. The growth of Paracoccus halodenitrificans in a defined medium

    NASA Technical Reports Server (NTRS)

    Hochstein, L. I.; Tomlinson, G. A.

    1984-01-01

    A synthetic medium, consisting of inorganic salts and any of a number of carbon sources, supported the aerobic growth of Paracoccus halodenitrificans when supplemented with thiamine. The same medium plus a nitrogenous oxide supported anaerobic growth when additionally supplemented with methionine. The observation that vitamin B12 or betaine replaced methionine suggested that P. halodenitrificans had a defect in the cobalamin dependent pathway for methionine biosynthesis, as well as the inability to synthesize betanine when growing anaerobically.

  17. Evaluation of CHROMagar STEC and STEC O104 Chromogenic Agar Media for Detection of Shiga Toxin-Producing Escherichia coli in Stool Specimens

    PubMed Central

    Ruckly, Corinne; Carle, Isabelle; Lejay-Collin, Monique

    2013-01-01

    The performance of CHROMagar STEC and CHROMagar STEC O104 (CHROMagar Microbiology, Paris, France) media for the detection of Shiga toxin-producing Escherichia coli (STEC) was assessed with 329 stool specimens collected over 14 months from patients with suspected STEC infections (June 2011 to August 2012). The CHROMagar STEC medium, after an enrichment broth step, allowed the recovery of the STEC strain from 32 of the 39 (82.1%) Shiga toxin-positive stool specimens, whereas the standard procedure involving Drigalski agar allowed the recovery of only three additional STEC strains. The isolates that grew on CHROMagar STEC medium belonged to 15 serotypes, including the prevalent non-sorbitol-fermenting (NSF) O157:H7, O26:H11, and O104:H4 serotypes. The sensitivity, specificity, and positive and negative predictive values for the CHROMagar STEC medium were between 89.1% and 91.4%, 83.7% and 86.7%, 40% and 51.3%, and 98% and 98.8%, respectively, depending on whether or not stx-negative eae-positive E. coli was considered atypical enteropathogenic E. coli (EPEC) or STEC that had lost Shiga toxin genes during infection. In conclusion, the good performance of CHROMagar STEC agar medium, in particular, the high negative predictive value, and its capacity to identify NSF O157:H7 as well as common non-O157 STEC may be useful for clinical bacteriology, public health, and reference laboratories; it could be used in addition to a method targeting Shiga toxins (detection of stx genes by PCR, immunodetection of Shiga toxins in stool specimens, or Vero cell cytotoxicity assay) as an alternative to O157 culture medium. This combined approach should allow rapid visualization of both putative O157 and non-O157 STEC colonies for subsequent characterization, essential for real-time surveillance of STEC infections and investigations of outbreaks. PMID:23284030

  18. Evaluation of CHROMagar STEC and STEC O104 chromogenic agar media for detection of Shiga Toxin-producing Escherichia coli in stool specimens.

    PubMed

    Gouali, Malika; Ruckly, Corinne; Carle, Isabelle; Lejay-Collin, Monique; Weill, François-Xavier

    2013-03-01

    The performance of CHROMagar STEC and CHROMagar STEC O104 (CHROMagar Microbiology, Paris, France) media for the detection of Shiga toxin-producing Escherichia coli (STEC) was assessed with 329 stool specimens collected over 14 months from patients with suspected STEC infections (June 2011 to August 2012). The CHROMagar STEC medium, after an enrichment broth step, allowed the recovery of the STEC strain from 32 of the 39 (82.1%) Shiga toxin-positive stool specimens, whereas the standard procedure involving Drigalski agar allowed the recovery of only three additional STEC strains. The isolates that grew on CHROMagar STEC medium belonged to 15 serotypes, including the prevalent non-sorbitol-fermenting (NSF) O157:H7, O26:H11, and O104:H4 serotypes. The sensitivity, specificity, and positive and negative predictive values for the CHROMagar STEC medium were between 89.1% and 91.4%, 83.7% and 86.7%, 40% and 51.3%, and 98% and 98.8%, respectively, depending on whether or not stx-negative eae-positive E. coli was considered atypical enteropathogenic E. coli (EPEC) or STEC that had lost Shiga toxin genes during infection. In conclusion, the good performance of CHROMagar STEC agar medium, in particular, the high negative predictive value, and its capacity to identify NSF O157:H7 as well as common non-O157 STEC may be useful for clinical bacteriology, public health, and reference laboratories; it could be used in addition to a method targeting Shiga toxins (detection of stx genes by PCR, immunodetection of Shiga toxins in stool specimens, or Vero cell cytotoxicity assay) as an alternative to O157 culture medium. This combined approach should allow rapid visualization of both putative O157 and non-O157 STEC colonies for subsequent characterization, essential for real-time surveillance of STEC infections and investigations of outbreaks.

  19. Effects of medium concentration on antibody production

    NASA Technical Reports Server (NTRS)

    Williams, J.

    1984-01-01

    Antibody production by two different cell lines was measured as the media were supplemented with varied amounts of glucose and fetal bovine serum. Both cell lines elaborated antidinitrophenyl hapten antibodies. Two basic media were used: RPMI 1640 and Dulbecco's modified Eagle's medium. The production of antibodies was followed from 0 to 180 h and was assayed by radioimmunoassay.

  20. Normal calves produced after transfer of embryos cultured in a chemically defined medium supplemented with epidermal growth factor and insulin-like growth factor I following ovum pick up and in vitro fertilization in Japanese black cows.

    PubMed

    Sakagami, Nobutada; Umeki, Hidenobu; Nishino, Osamu; Uchiyama, Hiroko; Ichikawa, Kyoko; Takeshita, Kazuhisa; Kaneko, Etsushi; Akiyama, Kiyoshi; Kobayashi, Shuji; Tamada, Hiromichi

    2012-01-01

    The objective of this study was to examine whether high concentrations of epidermal growth factor (EGF) and/or insulin-like growth factor I (IGF-I) would have a beneficial effect on bovine embryo development in vitro and to obtain normal calves by using an ovum pick up method and embryo culture in a chemically defined medium. When compared with controls, EGF (100 or 200 ng/ml) or IGF-I (50 or 100 ng/ml) significantly increased the rate of embryos that developed into blastocysts during an 8-day culture after the in vitro fertilization of oocytes obtained from ovaries from a slaughterhouse. IGF-I induced a dose-dependent increase in cell number in both the inner cell mass and the trophectoderm, whereas EGF stimulated proliferation only in the inner cell mass. A combination of EGF (100 ng/ml) and IGF-I (50 ng/ml) produced an additive effect, and embryos developed into blastocysts at a comparatively high rate (27.9%) compared with controls (12.0%). A similar rate of development was achieved using a combination of EGF and IGF-I in the culture of embryos following ovum pick up by ultrasound-guided transvaginal follicular aspiration and in vitro fertilization, and 5 blastocysts that developed after the culture were transferred into uteri; two embryos implanted, and normal calves were born. These results suggest that the combined use of EGF and IGF-I makes bovine embryo culture in a chemically defined medium a practical and useful procedure for producing blastocysts, and its application to embryo culture following ovum pick up and in vitro fertilization could be useful for producing normal calves.

  1. Comparison of Agar Media for Detection and Quantification of Shiga Toxin-Producing Escherichia coli in Cattle Feces.

    PubMed

    Stromberg, Zachary R; Lewis, Gentry L; Moxley, Rodney A

    2016-06-01

    The isolation and quantification of non-O157 Shiga toxin-producing Escherichia coli (STEC) from cattle feces are challenging. The primary objective of this study was to evaluate the performance of selected agar media in an attempt to identify an optimal medium for the detection and quantification of non-O157 STEC in cattle feces. Comparison studies were performed using CHROMagar STEC, Possé differential agar (Possé), Possé modified by the reduction or addition of antimicrobials, STEC heart infusion washed blood agar with mitomycin C (SHIBAM), and SHIBAM modified by the addition of antimicrobials. Fourteen STEC strains, two each belonging to serogroups O26, O45, O103, O111, O121, O145, and O157, were used to test detection in inoculated fecal suspensions at concentrations of 10(2) or 10(3) CFU/g. One STEC strain from each of these seven serogroups was used to estimate the concentration of recovered STEC in feces inoculated at 10(3), 10(4), or 10(5) CFU/g. Significantly more suspensions (P < 0.05) were positive for STEC when plated on Possé containing reduced concentrations of novobiocin and potassium tellurite compared with SHIBAM, but not SHIBAM modified by containing these same antimicrobials at the same concentrations. Numerically, more suspensions were positive for STEC by using this same form of modified Possé compared with Possé, but this difference was not statistically significant. More suspensions were positive for STEC cultured on CHROMagar STEC compared with those on Possé (P < 0.05) and on modified Possé (P = 0.05). Most inoculated fecal suspensions below 10(4) CFU/g of feces were underestimated or not quantifiable for the concentration of STEC by using CHROMagar STEC or modified Possé. These results suggest that CHROMagar STEC performs better than Possé or SHIBAM for detection of STEC in bovine feces, but adjustments in the concentrations of novobiocin and potassium tellurite in the latter two media result in significant improvements in their

  2. Comparison of Agar Media for Detection and Quantification of Shiga Toxin-Producing Escherichia coli in Cattle Feces.

    PubMed

    Stromberg, Zachary R; Lewis, Gentry L; Moxley, Rodney A

    2016-06-01

    The isolation and quantification of non-O157 Shiga toxin-producing Escherichia coli (STEC) from cattle feces are challenging. The primary objective of this study was to evaluate the performance of selected agar media in an attempt to identify an optimal medium for the detection and quantification of non-O157 STEC in cattle feces. Comparison studies were performed using CHROMagar STEC, Possé differential agar (Possé), Possé modified by the reduction or addition of antimicrobials, STEC heart infusion washed blood agar with mitomycin C (SHIBAM), and SHIBAM modified by the addition of antimicrobials. Fourteen STEC strains, two each belonging to serogroups O26, O45, O103, O111, O121, O145, and O157, were used to test detection in inoculated fecal suspensions at concentrations of 10(2) or 10(3) CFU/g. One STEC strain from each of these seven serogroups was used to estimate the concentration of recovered STEC in feces inoculated at 10(3), 10(4), or 10(5) CFU/g. Significantly more suspensions (P < 0.05) were positive for STEC when plated on Possé containing reduced concentrations of novobiocin and potassium tellurite compared with SHIBAM, but not SHIBAM modified by containing these same antimicrobials at the same concentrations. Numerically, more suspensions were positive for STEC by using this same form of modified Possé compared with Possé, but this difference was not statistically significant. More suspensions were positive for STEC cultured on CHROMagar STEC compared with those on Possé (P < 0.05) and on modified Possé (P = 0.05). Most inoculated fecal suspensions below 10(4) CFU/g of feces were underestimated or not quantifiable for the concentration of STEC by using CHROMagar STEC or modified Possé. These results suggest that CHROMagar STEC performs better than Possé or SHIBAM for detection of STEC in bovine feces, but adjustments in the concentrations of novobiocin and potassium tellurite in the latter two media result in significant improvements in their

  3. [Analysis of bactericidal material generated by electrical devices advertising bactericidal ability against bacteria on the agar gel plates].

    PubMed

    Nishimura, Hidekazu

    2012-11-01

    Several Japanese companies sell electrical devices advertised as effective in inactivating viruses and killing bacteria by releasing special materials, e.g., Plasmacluster ions, Nanoe particle and minus ions, into the air. These companies claim that their devices killed bacteria on plates in their own experiments. We tested device effectiveness using the same experiments from the Plasmacluster ioniser SHARP Co., Japan, the Nanoe generator Panasonic Co., Japan, and the Vion KING JIM Co., Japan, to test their advertising claims. Bactericidal ability on agar plate was tested, using Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus cereus, and Enterococcus faecalis as follows: the medium containing a certain amount of each bacterium was put onto an agar plate and smeared. Plates were kept in a closed chamber (inner volume 14.4 m3) or a glove box (inner volume 0.2 m), with one of the devices run for 2 hours. Plates not exposed to any device were used as controls. Each plate was retrieved and put in an incubator to count the number of bacterial colonies formed on the plate. There was no significant difference in the number of colonies on plates exposed to devices compared to control, in the number for all devices, or in all bacteria tested in experiments in the 14.4 m3 chamber. These results strongly suggest that these devices have almost no bactericidal effect, at least in space exceeding this volume. Colony formation was suppressed in the glove box in all devices and in all bacteria tested except P. aeruginosa, although the degree of suppression differed among experiments. The colony formation suppression mechanism was analyzed, and indicated that:colony formation did not change even after the removal of Plasmacluster ions, Nanoe particles, or negative ions from the air, while colony formation was decreased drastically by the removal of ozone from space, which was revealed to be generated inevitably during device operation. These results strongly suggest that the

  4. CHROMagar Orientation Medium Reduces Urine Culture Workload

    PubMed Central

    Manickam, Kanchana; Karlowsky, James A.; Adam, Heather; Lagacé-Wiens, Philippe R. S.; Rendina, Assunta; Pang, Paulette; Murray, Brenda-Lee

    2013-01-01

    Microbiology laboratories continually strive to streamline and improve their urine culture algorithms because of the high volumes of urine specimens they receive and the modest numbers of those specimens that are ultimately considered clinically significant. In the current study, we quantitatively measured the impact of the introduction of CHROMagar Orientation (CO) medium into routine use in two hospital laboratories and compared it to conventional culture on blood and MacConkey agars. Based on data extracted from our Laboratory Information System from 2006 to 2011, the use of CO medium resulted in a 28% reduction in workload for additional procedures such as Gram stains, subcultures, identification panels, agglutination tests, and biochemical tests. The average number of workload units (one workload unit equals 1 min of hands-on labor) per urine specimen was significantly reduced (P < 0.0001; 95% confidence interval [CI], 0.5326 to 1.047) from 2.67 in 2006 (preimplementation of CO medium) to 1.88 in 2011 (postimplementation of CO medium). We conclude that the use of CO medium streamlined the urine culture process and increased bench throughput by reducing both workload and turnaround time in our laboratories. PMID:23363839

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

    PubMed Central

    Yücesoy, Mine; Marol, Serhat

    2003-01-01

    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. PMID:14613587

  6. Effects of Solid-Medium Type on Routine Identification of Bacterial Isolates by Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

    PubMed Central

    Anderson, Neil W.; Buchan, Blake W.; Riebe, Katherine M.; Parsons, Lauren N.; Gnacinski, Stacy

    2012-01-01

    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. PMID:22162546

  7. A New Alkaline pH-Adjusted Medium Enhances Detection of β-Hemolytic Streptococci by Minimizing Bacterial Interference Due to Streptococcus salivarius

    PubMed Central

    Dierksen, Karen P.; Ragland, Nancy L.; Tagg, John R.

    2000-01-01

    A new selective medium (CNA-P) that reduces or eliminates the inhibitory activity of bacteriocin-producing Streptococcus salivarius against β-hemolytic streptococci has been developed and compared with sheep blood agar (SBA) for the sensitive detection of small numbers of β-hemolytic streptococci in clinical specimens. CNA-P has as its basis a commercial medium (Difco Columbia CNA agar) supplemented with 5% (vol/vol) sheep blood, and the CNA is further modified by addition of 100 mM PIPES buffer [piperazine-N,N′-bis(2-ethanesulfonic acid)] (pH 7.5) to maintain cultures at an alkaline pH during incubation. CNA-P was shown to inhibit the production and/or release of four different types of S. salivarius bacteriocins or bacteriocin-like inhibitory molecules. The efficacies of CNA-P and SBA for detection of β-hemolytic streptococci in 1,352 pharyngeal samples from 376 children were compared. The β-hemolytic streptococcal isolates recovered from the samples included 314 group A (S. pyogenes), 61 group G, 33 group B, and 5 group C streptococci. Of 314 samples that yielded S. pyogenes, 300 were positive on CNA-P (96%) and 264 (86%) were positive on SBA. A significantly greater number of S. pyogenes isolates from these samples were recovered only on CNA-P (50 of 314) compared with the number of isolates recovered only on SBA (14 of 314). In addition, the degree of positivity, a measure of the total numbers of S. pyogenes isolates on the plate, was significantly higher on CNA-P than on SBA (2.40 versus 2.07; P < 0.001). Interestingly, CNA-P was also found to enhance the hemolytic activity of streptolysin O, allowing detection of streptolysin S-deficient S. pyogenes strains which might otherwise go undetected on SBA and other isolation media. PMID:10655361

  8. Evaluation of cycloserine-cefoxitin fructose agar (CCFA), CCFA with horse blood and taurocholate, and cycloserine-cefoxitin mannitol broth with taurocholate and lysozyme for recovery of Clostridium difficile isolates from fecal samples.

    PubMed

    Tyrrell, Kerin L; Citron, Diane M; Leoncio, Eliza S; Merriam, C Vreni; Goldstein, Ellie J C

    2013-09-01

    Cycloserine-cefoxitin fructose agar (CCFA), CCFA with horse blood and taurocholate (CCFA-HT), and cycloserine-cefoxitin mannitol broth with taurocholate and lysozyme (CCMB-TAL) were compared for recovery of Clostridium difficile from 120 stool specimens. Compared to CCFA, CCFA-HT enhanced C. difficile growth and improved recovery by 4%. In a separate study, 9% (8/91) of stool samples previously C. difficile negative on plate medium were C. difficile positive when cultured in CCMB-TAL.

  9. Wood and humus decay strategies by white-rot basidiomycetes correlate with two different dye decolorization and enzyme secretion patterns on agar plates.

    PubMed

    Barrasa, José M; Blanco, María N; Esteve-Raventós, Fernando; Altés, Alberto; Checa, Julia; Martínez, Angel T; Ruiz-Dueñas, Francisco J

    2014-11-01

    During several forays for ligninolytic fungi in different Spanish native forests, 35 white-rot basidiomycetes growing on dead wood (16 species from 12 genera) and leaf litter (19 species from 10 genera) were selected for their ability to decolorize two recalcitrant aromatic dyes (Reactive Blue 38 and Reactive Black 5) added to malt extract agar medium. In this study, two dye decolorization patterns were observed and correlated with two ecophysiological groups (wood and humus white-rot basidiomycetes) and three taxonomical groups (orders Polyporales, Hymenochaetales and Agaricales). Depending on the above groups, different decolorization zones were observed on the dye-containing plates, being restricted to the colony area or extending to the surrounding medium, which suggested two different decay strategies. These two strategies were related to the ability to secrete peroxidases and laccases inside (white-rot wood Polyporales, Hymenochaetales and Agaricales) and outside (white-rot humus Agaricales) of the fungal colony, as revealed by enzymatic tests performed directly on the agar plates. Similar oxidoreductases production patterns were observed when fungi were grown in the absence of dyes, although the set of enzyme released was different. All these results suggest that the decolorization patterns observed could be related with the existence of two decay strategies developed by white-rot basidiomycetes adapted to wood and leaf litter decay in the field.

  10. Limitations of the clonal agar assay for the assessment of primary human ovarian tumour biopsies.

    PubMed Central

    Bertoncello, I.; Bradley, T. R.; Campbell, J. J.; Day, A. J.; McDonald, I. A.; McLeish, G. R.; Quinn, M. A.; Rome, R.; Hodgson, G. S.

    1982-01-01

    114 biopsy specimens from 70 patients with ovarian carcinoma at all stages of disease were submitted for assessment of clonogenic capacity in agar. A highly significant correlation was found between agar clonogenicity and patient survival after biopsy. However, problems related to inherent tumour heterogeneity, quality of sample and tissue disaggregation indicate that this technique may have limited applicability in the routine assessment of patients. Only 41 biopsy specimens (36%) from 31 patients (44.3%) complied with the prerequisite criteria for agar clonogenic assessment, namely: (a) the confirmed presence of malignant cells in the biopsy, (b) the ability to prepare a single-cell suspension, and (c) adequate viable cell numbers for assay. Furthermore, although the dominant patterns of agar clonogenic growth could be identified and correlated with stage of disease, the heterogeneity in both initial clonogenic capacity and "self-renewal" capacity assessed by the ability of primary clones to propagate in liquid culture and reclone in agar was too inconsistent for the assay to be used as a prognostic index for the individual patient. Images Figure PMID:7093117

  11. Cell aggregation on agar as an indicator for cell-matrix adhesion: effects of opioids.

    PubMed

    Debruyne, Delphine; Mareel, Marc; Vanhoecke, Barbara; Bracke, Marc

    2009-09-01

    The slow aggregation assay is generally used to study the functionality of cell-cell adhesion complexes. Single cells are seeded on a semisolid agar substrate in a 96-well plate and the cells spontaneously aggregate. We used HEK FLAG-MOP cells that stably overexpress the mu opioid receptor and the mu-opioid-receptor-selective agonists DAMGO and morphine to study whether other factors than functionality of cell-cell adhesions complexes can contribute to changes in the pattern of slow aggregation on agar. HEK FLAG-MOP cells formed small compact aggregates. In the presence of DAMGO and morphine, larger and fewer aggregates were formed in comparison to the vehicle control. These aggregates were localized in the center of the agar surface, whereas in the vehicle control they were dispersed over the substrate. However, in suspension culture on a Gyrotory shaker, no stimulation of aggregation was observed by DAMGO and morphine, showing that opioids do not affect affinity. A dissociation experiment revealed that HEK FLAG-MOP aggregates formed in the absence or presence of opioids are resistant to de-adhesion. We demonstrated that the larger aggregates are neither the result of cell growth stimulation by DAMGO and morphine. Since manipulations of the substrate such as increasing the agar concentration or mixing agar with agarose induced the same changes in the pattern of slow aggregation as treatment with opioids, we suggest that cell-substrate adhesion may be involved in opioid-stimulated aggregation.

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

    PubMed

    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. PMID:24507339

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

    PubMed

    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. PMID:25827444

  14. Novel grafted agar disks for the covalent immobilization of β-D-galactosidase.

    PubMed

    Wahba, Marwa I; Hassan, Mohamed E

    2015-12-01

    Novel grafted agar disks were prepared for the covalent immobilization of β-D-galactosidase (β-gal). The agar disks were activated through reacting with ethylenediamine or different molecular weights of Polyethyleneimine (PEI), followed by glutaraldehyde (GA). The modification of the agar gel and the binding of the enzyme were verified by Fourier Transform Infrared (FTIR) and elemental analysis. Moreover, the agar's activation process was optimized, and the amount of immobilized enzyme increased 3.44 folds, from 38.1 to 131.2 U/g gel, during the course of the optimization process. The immobilization of β-gal onto the activated agar disks caused its optimum temperature to increase from 45°C to 45-55°C. The optimum pH of the enzyme was also shifted towards the acidic side (3.6-4.6) after its immobilization. Additionally, the Michaelis-Menten constant (Km ) increased for the immobilized β-gal as compared to its free counterpart whereas the maximum reaction rate (Vmax ) decreased. The immobilized enzyme was also shown to retain 92.99% of its initial activity after being used for 15 consecutive times.

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

    PubMed

    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.

  16. Preparation and characterization of agar/clay nanocomposite films: the effect of clay type.

    PubMed

    Rhim, Jong-Whan; Lee, Soo-Bin; Hong, Seok-In

    2011-04-01

    Agar-based nanocomposite films with different types of nanoclays, such as Cloisite Na+, Cloisite 30B, and Cloisite 20A, were prepared using a solvent casting method, and their tensile, water vapor barrier, and antimicrobial properties were tested. Tensile strength (TS), elongation at break (E), and water vapor permeability (WVP) of control agar film were 29.7±1.7 MPa, 45.3±9.6%, and (2.22±0.19)×10(-9) g·m/m2·s·Pa, respectively. All the film properties tested, including transmittance, tensile properties, WVP, and X-ray diffraction patterns, indicated that Cloisite Na+ was the most compatible with agar matrix. TS of the nanocomposite films prepared with 5% Cloisite Na+ increased by 18%, while WVP of the nanocomposite films decreased by 24% through nanoclay compounding. Among the agar/clay nanocomposite films tested, only agar/Cloisite 30B nanocomposite film showed a bacteriostatic function against Listeria monocytogenes.

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

    PubMed

    Sousa, Ana M M; Gonçalves, Maria P

    2015-11-01

    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. PMID:26256341

  18. Cost-effective nanoporous Agar-Agar polymer/Nickel powder composite particle for effective bio-products adsorption by expanded bed chromatography.

    PubMed

    Asgari, Setareh; Jahanshahi, Mohsen; Rahimpour, Ahmad

    2014-09-26

    In the present work a novel kind of dense nanoporous composite matrix for expanded bed application has been successfully first prepared with Nickel powder as a densifier and was covered with Agar-Agar layer as a skeleton, through the method of water-in-oil emulsification. Agar-Agar is a porous and inexpensive polymer. In order to fabricate cost-effective adsorbent with favorable qualities Agar-Agar polymer was used. Thereafter, the customized composite particle was modified by pseudo-affinity dye-ligand, Reactive Blue 4 (RB4), aimed at preparing a pseudo-affinity adsorbent (RB4-Agar-Ni) for bioprodut adsorption from aqueous solution. Bovine Serum Albumin (BSA) was selected as a model protein to investigate the adsorption behavior in batchwise and expanded bed chromatography, and the obtained results were evaluated with that of Streamline™ (Amersham-Pharmacia Biotech, Sweden). Spherical appearance and porous structure of composite particles were observed by the optical microscope (OM) and scanning electronic microscope (SEM). The results suggested that the matrices followed the logarithmic normal size distribution with the range of 65-300 μm and average diameter of 126.81-151.47 μm, proper wet density of 1.64-2.78 g/ml, water content of 62.74-34%, porosity of 98-90% and pore size of about 38-130 nm. For better comprehension of the impact of solid phase properties on the performance of the expanded bed, the expansion and hydrodynamic properties of a composite matrix with a series of densities was evaluated and estimated by the retention time distribution method (RTD) in an expanded bed and was compared with that of other matrices. According to obtained results the expansion factors under the same fluid velocity decreased by increasing the matrix density. Moreover, the axial dispersion coefficient (Dax) is the most appropriate parameter for evaluating the stability of expanded bed, on various operating conditions, such as different flow velocity, bed expansion

  19. Cost-effective nanoporous Agar-Agar polymer/Nickel powder composite particle for effective bio-products adsorption by expanded bed chromatography.

    PubMed

    Asgari, Setareh; Jahanshahi, Mohsen; Rahimpour, Ahmad

    2014-09-26

    In the present work a novel kind of dense nanoporous composite matrix for expanded bed application has been successfully first prepared with Nickel powder as a densifier and was covered with Agar-Agar layer as a skeleton, through the method of water-in-oil emulsification. Agar-Agar is a porous and inexpensive polymer. In order to fabricate cost-effective adsorbent with favorable qualities Agar-Agar polymer was used. Thereafter, the customized composite particle was modified by pseudo-affinity dye-ligand, Reactive Blue 4 (RB4), aimed at preparing a pseudo-affinity adsorbent (RB4-Agar-Ni) for bioprodut adsorption from aqueous solution. Bovine Serum Albumin (BSA) was selected as a model protein to investigate the adsorption behavior in batchwise and expanded bed chromatography, and the obtained results were evaluated with that of Streamline™ (Amersham-Pharmacia Biotech, Sweden). Spherical appearance and porous structure of composite particles were observed by the optical microscope (OM) and scanning electronic microscope (SEM). The results suggested that the matrices followed the logarithmic normal size distribution with the range of 65-300 μm and average diameter of 126.81-151.47 μm, proper wet density of 1.64-2.78 g/ml, water content of 62.74-34%, porosity of 98-90% and pore size of about 38-130 nm. For better comprehension of the impact of solid phase properties on the performance of the expanded bed, the expansion and hydrodynamic properties of a composite matrix with a series of densities was evaluated and estimated by the retention time distribution method (RTD) in an expanded bed and was compared with that of other matrices. According to obtained results the expansion factors under the same fluid velocity decreased by increasing the matrix density. Moreover, the axial dispersion coefficient (Dax) is the most appropriate parameter for evaluating the stability of expanded bed, on various operating conditions, such as different flow velocity, bed expansion

  20. Laboratory and clinical evaluation of modified New York City medium (Henderson formulation) for the isolation of Neisseria gonorrhoeae.

    PubMed Central

    Anstey, R J; Gun-Munro, J; Rennie, R P; Thornley, J H; Schaus, D G; Lannigan, R; Hussain, Z; Maharajah, R S

    1984-01-01

    The growth-promoting properties of several ingredients of New York City (NYC) medium were investigated by using 100 recently isolated clinical strains of Neisseria gonorrhoeae. Difco GC medium base promoted the growth of large colonies of gonococci significantly better than other commercial GC medium bases. A 1% agar concentration resulted in the growth of larger colonies than 2% agar, without affecting the stability of the gel. Neither replacement of horse plasma with horse serum nor reducing the concentration of added serum from 12 to 3% affected the growth of even the most fastidious strains tested. From these observations, a modified NYC medium (Henderson) has been formulated which is easy to prepare and less expensive than NYC or Thayer-Martin medium. In a direct clinical comparison with 1,275 specimens, an isolation rate of 6.5% was achieved with both NYC medium and the Henderson formulation. PMID:6439732

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

    NASA Technical Reports Server (NTRS)

    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. Commercially marketed supplements for bodybuilding athletes.

    PubMed

    Grunewald, K K; Bailey, R S

    1993-02-01

    We conducted a survey of 624 commercially available supplements targeted towards bodybuilding athletes. Over 800 performance claims were made for these supplements. Supplements include amino acids, boron, carnitine, choline, chromium, dibencozide, ferulic acid, gamma oryzanol, medium chain triglycerides, weight gain powders, Smilax compounds and yohimbine. Many performance claims advertised were not supported by published research studies. In some instances, we found no research to validate the claims; in other cases, research findings were extrapolated to inappropriate applications. For example, biological functions of some non-essential compounds were interpreted as performance claims for the supplements. Claims for others were based on their ability to enhance hormonal release or activity. We suggest that more research be conducted on this group of athletes and their nutritional needs. Furthermore, the effectiveness and safety of supplements merit further investigation.

  3. Selective medium for recovering specific populations of rhizobia introduced into tropical soils.

    PubMed

    Habte, M

    1985-12-01

    Experiments were designed to evaluate the usefulness of antifungal agents and streptomycin for recovering low densities of rhizobia inoculated into tropical soils. The results showed that yeast-mannitol agar (pH 6.0) containing 500 mug of streptomycin, 400 mug of cycloheximide and 50 mug of benomyl or chlorothalonil per ml was the best selective medium. PMID:16346957

  4. Removal of 2,4-dinitrotoluene from concrete using bioremediation, agar extraction, and photocatalysis.

    PubMed

    Phutane, S R; Renner, J N; Nelson, S L; Seames, W S; Páca, J; Sundstrom, T J; Kozliak, E I

    2007-01-01

    Three methods, i.e. bioremediation by application of bacteria-laden agar, physical absorption of DNT by agar, or illumination by UV light were evaluated for the removal of 2,4-dinitrotoluene (DNT) from building-grade concrete. DNT biodegradation by Pseudomonas putida TOD was turned "on" and "off" by using toluene as a co-substrate thus allowing for rate-limiting step assessment. Bioremediation efficiency can be > 95-97% in 5-7 d if the process occurs at optimum growth temperature with the biological processes appearing to be rate-limiting. Sterile agar can remove up to 80% of DNT from concrete thus allowing DNT desorption and biodegradation to be conducted separately. Photoremediation results in 50% DNT removal in 9-12 d with no further removal, most likely due to mass transfer limitations.

  5. Effect of Diethylaminoethyl Dextran on the Growth of Mycoplasma in Agar

    PubMed Central

    Tauraso, Nicola M.

    1967-01-01

    The growth of certain strains of Mycoplasma is inhibited by substances present in commercial agar preparations. The addition of diethylaminoethyl (DEAE) dextran (10 mg per 100 ml) to agar media appears to enhance the growth of some strains. Of eight strains initially tested, the presence of DEAE dextran grossly enhanced the growth of three strains. One strain appeared not to be affected, and a clearly enhancing effect was not evident with four strains. Quantitative studies revealed that growth enhancement varied from 10 colony-forming units (CFU) for M. hominis type II (strain Campo) to 103.3 CFU for M. pulmonis (strain 880). The growth-enhancing effect is probably due to the ability of DEAE dextran to bind the sulfated polysaccharide moieties in agar and not to the DEAE dextran, per se. Images PMID:6025444

  6. Expression of an accessory cell phenotype by hairy cells during lymphocyte colony formation in agar culture.

    PubMed

    Farcet, J P; Gourdin, M F; Testa, U; Andre, C; Jouault, H; Reyes, F

    1983-01-01

    Human T lymphocytes require the cooperation of accessory cells to generate lymphocyte colonies in agar culture under PHA stimulation. Various hairy cell enriched fractions, as well as normal monocytes, have been found to be able to initiate colony formation by normal lymphocytes. Leukemic monocytes from CMML patients were also effective, but not the leukemic lymphocytes from CLL patients. The phenotype expressed by HC in agar colonies was further studied using cell surface and enzymatic markers. We have concluded that HC in agar culture in the presence of both normal T lymphocytes and PHA lose the B phenotype that they express in vivo and function like an accessory cell in contrast to normal or leukemic B lymphocytes. PMID:6601222

  7. Homogeneous Matrix Deposition on Dried Agar for MALDI Imaging Mass Spectrometry of Microbial Cultures

    NASA Astrophysics Data System (ADS)

    Hoffmann, Thomas; Dorrestein, Pieter C.

    2015-11-01

    Matrix deposition on agar-based microbial colonies for MALDI imaging mass spectrometry is often complicated by the complex media on which microbes are grown. This Application Note demonstrates how consecutive short spray pulses of a matrix solution can form an evenly closed matrix layer on dried agar. Compared with sieving dry matrix onto wet agar, this method supports analyte cocrystallization, which results in significantly more signals, higher signal-to-noise ratios, and improved ionization efficiency. The even matrix layer improves spot-to-spot precision of measured m/z values when using TOF mass spectrometers. With this technique, we established reproducible imaging mass spectrometry of myxobacterial cultures on nutrient-rich cultivation media, which was not possible with the sieving technique.

  8. Assessment of Etest as an alternative to agar dilution for antimicrobial susceptibility testing of Neisseria gonorrhoeae.

    PubMed

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

    2014-05-01

    We studied whether the Etest can be used as an alternative to agar dilution to determine antimicrobial susceptibilities of ceftriaxone, cefixime, and cefpodoxime in Neisseria gonorrhoeae surveillance. One hundred fifteen clinical and laboratory isolates of N. gonorrhoeae were tested following the Clinical Laboratory Improvement Amendments (CLIA)-approved CLSI standard agar dilution method and, separately, by the Etest according to the manufacturer's recommendations. The MICs were determined and compared. Ten laboratory-generated mutants were used to simulate substantially nonsusceptible specimens. The Etest and agar dilution methods were well correlated. Statistical tests produced regression R2 values of 88%, 82%, and 85% and Pearson correlation coefficients of 92%, 91%, and 92% for ceftriaxone, cefixime, and cefpodoxime, respectively. When paired comparisons were made, the two tests were 88.7%, 80%, and 87% within 1 log2 dilution from each other for ceftriaxone, cefixime, and cefpodoxime, respectively. The within-2-log2 agreements were 99.1%, 98.3%, and 94.8% for ceftriaxone, cefixime, and cefpodoxime, respectively. Notwithstanding the good correlations and the within-2-log2 general agreement, the Etest results produced slightly lower MICs than the agar dilution results. In conclusion, we found that the Etest can be effectively used as an alternative to agar dilution testing to determine the susceptibility of N. gonorrhoeae to ceftriaxone, cefixime, and cefpodoxime, although we recommend further research into extremely resistant isolates. For isolates within the typical range of clinical MICs, reexamination of the Etest interpretation of susceptible and nonsusceptible categories would likely allow for successful transition from agar dilution to the Etest.

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

    NASA Astrophysics Data System (ADS)

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

    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.

  10. Agar-polydimethylsiloxane devices for quantitative investigation of oviposition behaviour of adult Drosophila melanogaster

    PubMed Central

    Leung, Jacob C. K.; Taylor-Kamall, Rhodri W.; Hilliker, Arthur J.; Rezai, Pouya

    2015-01-01

    Drosophila melanogaster (fruit fly) is a model organism and its behaviours including oviposition (egg-laying) on agar substrates have been widely used for assessment of a variety of biological processes in flies. Physical and chemical properties of the substrate are the dominant factors affecting Drosophila's oviposition, but they have not been investigated precisely and parametrically with the existing manual approaches. As a result, many behavioral questions about Drosophila oviposition, such as the combined effects of the aforementioned substrate properties (e.g., exposure area, sugar content, and stiffness) on oviposition and viability, and their threshold values, are yet to be answered. In this paper, we have devised a simple, easily implementable, and novel methodology that allows for modification of physical and chemical composition of agar substrates in order to quantitatively study survival and oviposition of adult fruit flies in an accurate and repeatable manner. Agar substrates have been modified by surface patterning using single and hexagonally arrayed through-hole polydimethylsiloxane (PDMS) membranes with various diameters and interspacing, as well as by substrate stiffness and sugar content modification via alteration of chemical components. While pure PDMS substrates showed a significant lethal effect on flies, a 0.5 mm diameter through-hole access to agar was found to abruptly increase the survival of adult flies to more than 93%. Flies avoided ovipositing on pure PDMS and on top of substrates with 0.5 mm diameter agar exposure areas. At a hole diameter of 2 mm (i.e., 0.25% exposure area) or larger, eggs were observed to be laid predominately inside the through-holes and along the edges of the PDMS-agar interface, showing a trending increase in site selection with 4 mm (i.e., 1% exposure area threshold) demonstrating natural oviposition rates similar to pure agar. The surface-modified agar-PDMS hybrid devices and the threshold values

  11. A new culture medium for recovering the agents of Cryptococcosis from environmental sources.

    PubMed

    Castro e Silva, Dulcilena de Matos; Santos, Dayane C S; Pukinskas, Sandra R B S; Oshida, Julia T U; Oliveira, Lidiane; Carvallho, Anderson F; Melhem, Márcia S C

    2015-06-01

    The isolation of Cryptococcosis agents from environmental samples may be difficult due to the presence of groups of fast-growing fungi. We propose a new culture medium based on a modification of Dichloran Rose-Bengal Chloramphenicol Medium (DRBCm) to detect colonies of Cryptococcus neoformans. Our results indicate that DRBCm is superior to the classical Bird Seed Agar in its ability to detect colonies of C. neoformans. PMID:26273249

  12. A new culture medium for recovering the agents of Cryptococcosis from environmental sources

    PubMed Central

    Silva, Dulcilena de Matos Castro e; Santos, Dayane C.S.; Pukinskas, Sandra R.B.S.; Oshida, Julia T.U.; Oliveira, Lidiane; Carvallho, Anderson F.; Melhem, Márcia S.C.

    2015-01-01

    The isolation of Cryptococcosis agents from environmental samples may be difficult due to the presence of groups of fast-growing fungi. We propose a new culture medium based on a modification of Dichloran Rose-Bengal Chloramphenicol Medium (DRBCm) to detect colonies of Cryptococcus neoformans. Our results indicate that DRBCm is superior to the classical Bird Seed Agar in its ability to detect colonies of C. neoformans. PMID:26273249

  13. Use of conditioned medium for efficient transformation and cost-effective cultivation of Nannochloropsis salina.

    PubMed

    Kang, Nam Kyu; Lee, Bongsoo; Shin, Sung-Eun; Jeon, Seungjib; Park, Min S; Yang, Ji-Won

    2015-04-01

    The oleaginous microalga Nannochloropsis sp. has been spotlighted as a promising candidate in genetic engineering research for biodiesel production. However, one of the major bottlenecks in the genetic manipulation against Nannochloropsis sp. is low transformation efficiency. Based on the idea that they grow rapidly in broth culture, the effect of conditioned medium on colonization and transformation efficiency of Nannochloropsis salina was investigated. Cells grown on agar plates with 20-40% conditioned medium produced colonies that were approximately 2.3-fold larger than cells grown without conditioned medium. More importantly, the transformation efficiency was about 2-fold greater on plates with 30% conditioned medium relative to those without conditioned medium. In addition, FAME productivity in liquid cultures with 100% conditioned medium increased up to 20% compared with cultures of control medium. These results suggest that conditioned medium can be applied for efficient transformation and cost-effective cultivation of N. salina for biodiesel production. PMID:25656867

  14. INFLUENCE OF GROWTH MEDIUM ON ASSIMILATORY ACTIVITIES OF ESCHERICHIA COLI

    PubMed Central

    Clifton, C. E.

    1963-01-01

    Clifton, C. E. (Stanford University, Stanford, Calif.). Influence of growth medium on assimilatory activities of Escherichia coli. J. Bacteriol. 85:1371–1377. 1963.—Nutrient agargrown cells assimilate about 50% of the glucose added to washed suspensions (phosphate buffer, pH 7.2, 30 C), as indicated by O2 consumption or C14-uptake from uniformly labeled glucose. Most of the nonassimilated glucose is oxidized, but a small portion remains in forms other than glucose in the suspension medium. Cells from glucose agar, however, assimilate only about 20 to 30% of the U-glucose and ferment a considerable portion of the remainder, the extent of each being determined in part at least by growth conditions. Evidence is presented that this behavior is the result of metabolic controls induced during growth. C14 from U-glucose appeared in all fractions of either agar- or glucose agar-grown cells, the highest percentage being present in cellular matter insoluble in hot 5% trichloroacetic acid. Data on the distribution of C14 from 1-, 2-, and 6-glucose, and from acetate and pyruvate, are also presented. PMID:14047232

  15. Increased erythromycin production by alginate as a medium ingredient or immobilization support in cultures of Saccharopolyspora erythraea.

    PubMed

    Hamedi, J; Khodagholi, F; Hassani-Nasab, A

    2005-05-01

    Erythromycin production by Saccharopolyspora erythraea immobilized in 2% (w/v) calcium alginate or grown in medium containing 20 g sodium alginate/l inoculated with free cells was almost twice more than that of the control. S. erythraea did not consume alginate, agar, dextran, silicon antifoaming agent or cyclodextrin as a carbon source, although, all of these increased the production of erythromycin. Highest titer of erythromycin (2.3 times more than that of the control) was achieved in medium containing 1 g agar/l.

  16. Comparison and recovery of Escherichia coli and thermotolerant coliforms in water with a chromogenic medium incubated at 41 and 44.5 degrees C.

    PubMed

    Alonso, J L; Soriano, A; Carbajo, O; Amoros, I; Garelick, H

    1999-08-01

    This study compared the performance of a commercial chromogenic medium, CHROMagarECC (CECC), and CECC supplemented with sodium pyruvate (CECCP) with the membrane filtration lauryl sulfate-based medium (mLSA) for enumeration of Escherichia coli and non-E. coli thermotolerant coliforms (KEC). To establish that we could recover the maximum KEC and E. coli population, we compared two incubation temperature regimens, 41 and 44.5 degrees C. Statistical analysis by the Fisher test of data did not demonstrate any statistically significant differences (P = 0.05) in the enumeration of E. coli for the different media (CECC and CECCP) and incubation temperatures. Variance analysis of data performed on KEC counts showed significant differences (P = 0.01) between KEC counts at 41 and 44.5 degrees C on both CECC and CECCP. Analysis of variance demonstrated statistically significant differences (P = 0.05) in the enumeration of total thermotolerant coliforms (TTCs) on CECC and CECCP compared with mLSA. Target colonies were confirmed to be E. coli at a rate of 91.5% and KEC of likely fecal origin at a rate of 77.4% when using CECCP incubated at 41 degrees C. The results of this study showed that CECCP agar incubated at 41 degrees C is efficient for the simultaneous enumeration of E. coli and KEC from river and marine waters.

  17. Comparison and Recovery of Escherichia coli and Thermotolerant Coliforms in Water with a Chromogenic Medium Incubated at 41 and 44.5°C

    PubMed Central

    Alonso, Jose L.; Soriano, Adela; Carbajo, Oscar; Amoros, Inmaculada; Garelick, Hemda

    1999-01-01

    This study compared the performance of a commercial chromogenic medium, CHROMagarECC (CECC), and CECC supplemented with sodium pyruvate (CECCP) with the membrane filtration lauryl sulfate-based medium (mLSA) for enumeration of Escherichia coli and non-E. coli thermotolerant coliforms (KEC). To establish that we could recover the maximum KEC and E. coli population, we compared two incubation temperature regimens, 41 and 44.5°C. Statistical analysis by the Fisher test of data did not demonstrate any statistically significant differences (P = 0.05) in the enumeration of E. coli for the different media (CECC and CECCP) and incubation temperatures. Variance analysis of data performed on KEC counts showed significant differences (P = 0.01) between KEC counts at 41 and 44.5°C on both CECC and CECCP. Analysis of variance demonstrated statistically significant differences (P = 0.05) in the enumeration of total thermotolerant coliforms (TTCs) on CECC and CECCP compared with mLSA. Target colonies were confirmed to be E. coli at a rate of 91.5% and KEC of likely fecal origin at a rate of 77.4% when using CECCP incubated at 41°C. The results of this study showed that CECCP agar incubated at 41°C is efficient for the simultaneous enumeration of E. coli and KEC from river and marine waters. PMID:10427079

  18. 21 CFR 866.2450 - Supplement for culture media.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Supplement for culture media. 866.2450 Section 866... media. (a) Identification. A supplement for culture media is a device, such as a vitamin or sugar mixture, that is added to a solid or liquid basal culture medium to produce a desired formulation and...

  19. 21 CFR 866.2450 - Supplement for culture media.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Supplement for culture media. 866.2450 Section 866... media. (a) Identification. A supplement for culture media is a device, such as a vitamin or sugar mixture, that is added to a solid or liquid basal culture medium to produce a desired formulation and...

  20. 21 CFR 866.2450 - Supplement for culture media.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Supplement for culture media. 866.2450 Section 866... media. (a) Identification. A supplement for culture media is a device, such as a vitamin or sugar mixture, that is added to a solid or liquid basal culture medium to produce a desired formulation and...

  1. 21 CFR 866.2450 - Supplement for culture media.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Supplement for culture media. 866.2450 Section 866... media. (a) Identification. A supplement for culture media is a device, such as a vitamin or sugar mixture, that is added to a solid or liquid basal culture medium to produce a desired formulation and...

  2. 21 CFR 866.2450 - Supplement for culture media.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Supplement for culture media. 866.2450 Section 866... media. (a) Identification. A supplement for culture media is a device, such as a vitamin or sugar mixture, that is added to a solid or liquid basal culture medium to produce a desired formulation and...

  3. Applying Agar's Concept of "Languaculture" to Explain Asian Students' Experiences in the Australian Tertiary Context

    ERIC Educational Resources Information Center

    Norris, Lindy; Tsedendamba, Nara

    2015-01-01

    This paper reports part of a broader qualitative case study of Asian students "translation" (Agar, 2006) to study in an Australian university. The paper is concerned with the experiences of eight participants and their involvement in a training programme in the use of language learning strategies (LLS) to support their engagement with…

  4. THE MICROGARDENING COOKBOOK, DIRECTIONS FOR PREPARING DISHES AND TUBES OF STERILE NUTRIENT AGAR.

    ERIC Educational Resources Information Center

    CHANDLER, MARION N.

    THIS BOOKLET WAS PREPARED FOR TEACHER USE IN ASSOCIATION WITH THE ELEMENTARY SCIENCE STUDY UNIT "MICROGARDENING." IT CONTAINS DIRECTIONS FOR PREPARING CULTURE DISHES AND TUBES OF NUTRIENT STERILE AGAR FOR FUNGAL AND/OR BACTERIAL GROWTH. IT INCLUDES (1) LISTS OF NEEDED SUPPLIES AND EQUIPMENT, (2) DIRECTIONS FOR THE PREPARATION AND STERILIZATION OF…

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

    PubMed

    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.

  6. Seasonal variation in the biomass and agar yield from Gracilaria cervicornis and Hydropuntia cornea from Brazil.

    PubMed

    Marinho-Soriano, E; Silva, T S; Moreira, W S

    2001-04-01

    Seasonality of biomass and agar yield from two agarophytes (G. cervicornis and H. cornea) was determined. The biomass from G. cervicornis was higher (390 g m-2) during the dry season and lower during the rainy season (129 g m-2). The data analysis for G. cervicornis revealed a significant seasonal variation (P < 0.05). H. cornea did not show a clear seasonal variation and was present only from March to August. The peak in biomass for this species was recorded in April (383 g m-2) and was significantly different from the other months (P < 0.05). The agar yield for G. cervicornis varied from 11% to 20%, with generally higher values recorded during the dry season. The agar yield showed a highly significant variation (P < 0.001). Agar yield from H. cornea ranged from 29% to 41%, with a peak recorded in June. The results above indicate that H. cornea can be considered a good candidate for commercial use.

  7. Draft Genome Sequence of the Novel Agar-Digesting Marine Bacterium HQM9▿

    PubMed Central

    Du, Zongjun; Zhang, Zhewen; Miao, Tingting; Wu, Jiayan; Lü, Guoqiang; Yu, Jun; Xiao, Jingfa; Chen, Guanjun

    2011-01-01

    Strain HQM9, an aerobic, rod-shaped marine bacterium from red algae, can produce agarases and liquefy solid plating media efficiently when agar is used as a coagulant. Here we report the draft genome sequence and the initial findings from a preliminary analysis of strain HQM9, which should be a novel species of Flavobacteriaceae. PMID:21725015

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

    PubMed

    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. PMID:27131216

  9. Population cell differentiation of Serratia marcescens on agar surface and in broth culture.

    PubMed

    Lai, H C; Lai, M J; Lin-Chao, S; Lu, K T; Ho, S W

    1997-11-01

    The bacterium Serratia marcescens shows population surface migration (swarming) phenomenum on an LB swarming plate, and differentiated cells can be observed at the swarming front. How the cell population differentiates during swarming on the agar surface is not known, neither is it clear whether cells with differentiated characteristics can be observed in broth culture. To monitor the population cell differentiation in a highly sensitive way without cell destruction, experiments were designed using bacterial luciferase genes luxAB as the reporter genes to allow direct monitoring of the differentiating cells through bioluminescence. An isogenic S. marcescens strain was constructed with luxAB under the control of the promoter of flagellin gene hag (phag::luxAB). Patterns of cell differentiation were monitored either by direct X-ray film exposure and/or by Autolumat luminometer detection. Results show that population cell differentiation on the agar surface occurs first in a temporal and then spatial way during colonial growth. It was also found that cells harvested from both the spreading agar plate and broth culture showed differentiation patterns similar to those from swarming cells, suggesting that the agar surface culture may not be essential for the formation of differentiated cells.

  10. Comparison of the antibacterial activity of chelating agents using the agar diffusion method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The agar diffusion assay was used to examine antibacterial activity of 2 metal chelators. Concentrations of 0 to 40 mM of ethylenediaminetetraacetic acid (EDTA) and ethylenediamine-N,N’-disuccinic acid (EDDS) were prepared in 1.0 M potassium hydroxide (KOH). The pH of the solutions was adjusted to 1...

  11. Evolutionary consequences of putative intra- and interspecific hybridization in agaric fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agaric fungi of the southern Appalachians including the Great Smoky Mountains National Park are often heterozygous for the rDNA internal transcribed spacer region (ITS) with >42% of collections showing some level of heterozygosity for indels and/or base-pair substitutions. For these collections, int...

  12. Alternative plasticizers for the production of thermo-compressed agar films

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One percent agar (% wt) was dissolved in the deep eutectic solvent (DES), (2-hydroxyethyl) trimethylammonium chloride/urea at a 1:2 molar ratio, and successfully Electrospun into nanofibers. An existing electrospinning set-up, operated at 50 deg C, was adapted for use with an ethanol bath to collect...

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

    PubMed

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

    2014-01-01

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

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

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Long-term maintenance of fungal cultures on perlite in cryovials - an alternative for agar slants.

    PubMed

    Homolka, L; Lisá, L

    2008-01-01

    Cultures of 33 basidiomycete strains out of 35 tested were viable with unchanged characteristics after four years of maintenance on perlite in cryovials. These cultures can be a good substitute for agar cultures in long-term maintenance of fungi. For comparison, the storage under oil was evaluated but it turned out to be unsuitable for the majority of our cultures.

  17. Combined Use of Pastorex Staph-Plus and Either of Two New Chromogenic Agars, MRSA ID and CHROMagar MRSA, for Detection of Methicillin-Resistant Staphylococcus aureus▿

    PubMed Central

    Compernolle, Veerle; Verschraegen, Gerda; Claeys, Geert

    2007-01-01

    We describe the search toward a fast and reliable strategy to detect and confirm the presence of methicillin-resistant Staphylococcus aureus (MRSA) in screening samples. First, we evaluated the sensitivities and specificities of oxacillin resistance screening agar (ORSA) with enrichment (tryptic soy broth [TSB] and ORSA [TSB-ORSA]) and without enrichment (ORSA), MRSA ID (MRSA_ID) plates, and CHROMagar MRSA (C_MRSA) plates, all of which were inoculated with equal volumes of a suspension made by emulsifying screening swabs. Whereas the sensitivities after 48 h were similar for all media tested (77% for MRSA_ID and ORSA; 73% for C_MRSA and ORSA after enrichment [TSB-ORSA]), the specificities of MRSA_ID (98% after 24 h and 94% after 48 h) and C_MRSA (98% after 24 h and 90% after 48 h) were superior to the specificities of ORSAs (92% after 24 h and 83% after 48 h) and TSB-ORSA (86% after 24 h and 81% after 48 h). Subsequently, the performance of the Pastorex Staph-Plus agglutination test with presumptive MRSA isolates taken directly from chromogenic agars (direct_Pastorex agglutination) was compared to that of the Pastorex Staph-Plus agglutination test with isolates from blood agar subcultures (conventional_Pastorex agglutination). When the direct_Pastorex agglutination test on MRSA_ID plates was combined with Gram staining, the direct_Pastorex agglutination test with samples from MRSA_ID plates was as reliable as the conventional_Pastorex agglutination test with samples from blood agar subcultures from MRSA_ID plates. In contrast, the direct_Pastorex agglutination test with samples from C_MRSA plates gave false-negative results. Finally, we calculated the processing times of the four different strategies, namely, (i) enrichment in TSB supplemented with NaCl, subsequent culture on ORSA, and the conventional_Pastorex agglutination test; (ii) direct inoculation of ORSA combined with conventional_Pastorex agglutination test; (iii) direct inoculation of MRSA_ID plates

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

    PubMed

    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.

  19. Monensin-based medium for determination of total gram-negative bacteria and Escherichia coli.

    PubMed

    Petzel, J P; Hartman, P A

    1985-04-01

    Plate count-monensin-KCl (PMK) agar, for enumeration of both gram-negative bacteria and Escherichia coli, is composed of (per liter) 23.5 g of plate count agar, 35 mg of monensin, 7.5 g of KCl, and 75 mg of 4-methylumbelliferyl-beta-D-glucuronide (MUG). Monensin was added after the medium was sterilized. The diluent of choice for use with PMK agar was 0.1% peptone (pH 6.8); other diluents were unsatisfactory. Gram-negative bacteria (selected for by the ionophore monensin) can be used to judge the general quality or sanitary history of a commodity. E. coli (differentiated by its ability to hydrolyze the fluorogenic compound MUG) can be used to assess the safety of a commodity in regard to the possible presence of enteric pathogens. Pure-culture studies demonstrated that monensin completely inhibited gram-positive bacteria and had little or no effect on gram-negative bacteria. When gram-negative bacteria were injured by one of several methods, a few species (including E. coli) became sensitive to monensin; this sensitivity was completely reversed in most instances by the inclusion of KCl in the medium. When PMK agar was tested with food and environmental samples, 96% of 535 isolates were gram negative; approximately 68% of colonies from nonselective medium were gram negative. PMK agar was more selective than two other media against gram-positive bacteria and was less inhibitory for gram-negative bacteria. However, with water samples, KCl had an inhibitory effect on gram-negative bacteria, and it should therefore be deleted from monensin-containing medium for water analysis.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3890742

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

    PubMed

    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 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.

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

    PubMed Central

    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 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. PMID:26937632

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

    PubMed

    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 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. PMID:26937632

  3. Agar-Block Microcosms for Controlled Plant Tissue Decomposition by Aerobic Fungi

    PubMed Central

    Schilling, Jonathan S.

    2011-01-01

    The two principal methods for studying fungal biodegradation of lignocellulosic plant tissues were developed for wood preservative testing (soil-block; agar-block). It is well-accepted that soil-block microcosms yield higher decay rates, fewer moisture issues, lower variability among studies, and higher thresholds of preservative toxicity. Soil-block testing is thus the more utilized technique and has been standardized by American Society for Testing and Materials (ASTM) (method D 1413-07). The soil-block design has drawbacks, however, using locally-variable soil sources and in limiting the control of nutrients external (exogenous) to the decaying tissues. These drawbacks have emerged as a problem in applying this method to other, increasingly popular research aims. These modern aims include degrading lignocellulosics for bioenergy research, testing bioremediation of co-metabolized toxics, evaluating oxidative mechanisms, and tracking translocated elements along hyphal networks. Soil-blocks do not lend enough control in these applications. A refined agar-block approach is necessary. Here, we use the brown rot wood-degrading fungus Serpula lacrymans to degrade wood in agar-block microcosms, using deep Petri dishes with low-calcium agar. We test the role of exogenous gypsum on decay in a time-series, to demonstrate the utility and expected variability. Blocks from a single board rip (longitudinal cut) are conditioned, weighed, autoclaved, and introduced aseptically atop plastic mesh. Fungal inoculations are at each block face, with exogenous gypsum added at interfaces. Harvests are aseptic until the final destructive harvest. These microcosms are designed to avoid block contact with agar or Petri dish walls. Condensation is minimized during plate pours and during incubation. Finally, inoculum/gypsum/wood spacing is minimized but without allowing contact. These less technical aspects of agar-block design are also the most common causes of failure and the key source of

  4. Modification of the Congo red agar method to detect biofilm production by Staphylococcus epidermidis.

    PubMed

    Kaiser, Thaís Dias Lemos; Pereira, Eliezer Menezes; Dos Santos, Kátia Regina Netto; Maciel, Ethel Leonor Noia; Schuenck, Ricardo Pinto; Nunes, Ana Paula Ferreira

    2013-03-01

    Staphylococcus epidermidis in immunocompromised patients can cause bacteremia related to the use of catheter due to biofilm production. There are different phenotypic methods to detect biofilm formation. One method is based on culture in brain heart infusion agar (BHIA) containing sucrose and red Congo dye (original Congo red agar). Our group created a new CRA formula and we have confirmed its capacity to detect biofilm production in 210 S. epidermidis strains, including 76 (36.2%) icaAB gene-positive strains. Other parameters were also evaluated. The new CRA formula that gave the best results was BHIA with sucrose (5%), Congo red (0.08%), NaCl (1.5%), glucose (2%), and vancomycin (0.5 mg/mL) (vancomycin-modified CRA-CRAmod). The CRAmod plus vancomycin may be a promising tool and can help to determine the real participation of S. epidermidis in the infectious process.

  5. Colony morphotype on Sabouraud-triphenyltetrazolium agar: a simple and inexpensive method for Candida subspecies discrimination.

    PubMed Central

    Quindós, G; Fernández-Rodríguez, M; Burgos, A; Tellaetxe, M; Cisterna, R; Pontón, J

    1992-01-01

    A new method of Candida subspecies discrimination on Sabouraud-triphenyltetrazolium agar is reported. Five hundred sixty-two strains of Candida and Torulopsis glabrata, previously identified by conventional mycological methods, were studied. Each strain received a three-letter code and a number based on its colonial morphology. Sixteen morphotypes were found for Candida albicans, 6 were found for Candida parapsilosis, 4 were found for both Candida guilliermondii and Candida krusei, and 12 were found for Candida tropicalis. None of the 56 T. glabrata strains studied grew on this agar. A reproducibility of 95% was found for C. albicans. The simplicity and low cost could make this method useful for typing Candida spp. Images PMID:1400981

  6. Characterization of gelatin-agar based phase separated hydrogel, emulgel and bigel: a comparative study.

    PubMed

    Wakhet, Senggam; Singh, Vinay K; Sahoo, Saikat; Sagiri, Sai Sateesh; Kulanthaivel, Senthilguru; Bhattacharya, Mrinal K; Kumar, Naresh; Banerjee, Indranil; Pal, Kunal

    2015-02-01

    The current study describes the in-depth characterization of agar-gelatin based co-hydrogels, emulgels and bigels to have an insight about the differences in the properties of the formulations. Hydrogels have been extensively studied as vehicle for controlled drug release, whereas, the concept of emulgels and bigels is relatively new. The formulations were characterized by scanning electron microscopy, FTIR spectroscopy, XRD and mechanical properties. The biocompatibility and the ability of the formulations to be used as drug delivery vehicle were also studied. The scanning electron micrographs suggested the presence of internal phases within the agar-gelatin composite matrices of co-hydrogel, emulgel and bigel. FTIR and XRD studies suggested higher crystallinity of emulgels and bigels. Electrical impedance and mechanical stability of the emulgel and the bigel was higher than the hydrogel. The prepared formulations were found to be biocompatible and suitable for drug delivery applications.

  7. Modification of the Congo red agar method to detect biofilm production by Staphylococcus epidermidis.

    PubMed

    Kaiser, Thaís Dias Lemos; Pereira, Eliezer Menezes; Dos Santos, Kátia Regina Netto; Maciel, Ethel Leonor Noia; Schuenck, Ricardo Pinto; Nunes, Ana Paula Ferreira

    2013-03-01

    Staphylococcus epidermidis in immunocompromised patients can cause bacteremia related to the use of catheter due to biofilm production. There are different phenotypic methods to detect biofilm formation. One method is based on culture in brain heart infusion agar (BHIA) containing sucrose and red Congo dye (original Congo red agar). Our group created a new CRA formula and we have confirmed its capacity to detect biofilm production in 210 S. epidermidis strains, including 76 (36.2%) icaAB gene-positive strains. Other parameters were also evaluated. The new CRA formula that gave the best results was BHIA with sucrose (5%), Congo red (0.08%), NaCl (1.5%), glucose (2%), and vancomycin (0.5 mg/mL) (vancomycin-modified CRA-CRAmod). The CRAmod plus vancomycin may be a promising tool and can help to determine the real participation of S. epidermidis in the infectious process. PMID:23313084

  8. A method of test substance removal in agar colony assays using glass capillaries.

    PubMed

    Kastner, M; Maurer, H R

    1984-07-01

    A technique has been developed to remove test substances, after defined incubation periods, from clonogenic in vitro assays using agar-containing glass capillaries. Following removal from the capillaries, the entire agar gels were washed in petri dishes and redrawn into new capillaries. Using 8 radioactive biochemicals of molecular masses ranging from 150 to 1300 dalton the kinetics of diffusion between 1 and 20 min were determined. Using a wash solution-to-assay volume ratio of 20:1, a single washing for 10 min yielded between 90% and 99% removal by diffusion of test substances. By incorporating myelopoietic stem cells it was demonstrated that the cells to be assayed can be quantitatively transferred, without loss or stress, out of and back into capillaries. Thus the reversibility of test substance action can examined under defined conditions avoiding technical problems of previous methods.

  9. N-acetylgalatosamine-Mediated Regulation of the aga Operon by AgaR in Streptococcus pneumoniae

    PubMed Central

    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 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.

  10. Simulation of Bacillus subtilis biofilm growth on agar plate by diffusion–reaction based continuum model

    NASA Astrophysics Data System (ADS)

    Zhang, Xianlong; Wang, Xiaoling; Nie, Kai; Li, Mingpeng; Sun, Qingping

    2016-08-01

    Various species of bacteria form highly organized spatially-structured aggregates known as biofilms. To understand how microenvironments impact biofilm growth dynamics, we propose a diffusion–reaction continuum model to simulate the formation of Bacillus subtilis biofilm on an agar plate. The extended finite element method combined with level set method are employed to perform the simulation, numerical results show the quantitative relationship between colony morphologies and nutrient depletion over time. Considering that the production of polysaccharide in wild-type cells may enhance biofilm spreading on the agar plate, we inoculate mutant colony incapable of producing polysaccharide to verify our results. Predictions of the glutamate source biofilm’s shape parameters agree with the experimental mutant colony better than that of glycerol source biofilm, suggesting that glutamate is rate limiting nutrient for Bacillus subtilis biofilm growth on agar plate, and the diffusion-limited is a better description to the experiment. In addition, we find that the diffusion time scale is of the same magnitude as growth process, and the common-employed quasi-steady approximation is not applicable here.

  11. A modified method for the detection of microbial proteases on agar plates using tannic acid.

    PubMed

    Saran, Saurabh; Isar, Jasmine; Saxena, Rajendra Kumar

    2007-06-10

    In routine assay for the screening of microbes producing proteases, 10% trichloroaceticacid (TCA) is flooded on the milk agar plates after inoculation and required incubation to precipitate the protein. However, the clarity of the hydrolyzed zone is not very sharp and distinct. We herein present an improved assay for detecting the presence of extracellular protease from microorganisms on agar plates. In this method 10% tannic acid is flooded on the milk agar plate (in place of, TCA) to observe the zone of hydrolysis. Tannic acid sharply increases the colour intensity of the plate, as it favours the precipitation of the unhydrolyzed protein in the plate, thereby improving the contrast between the intact zones and the enzymatic lyses zones of the substrate. Our results indicate that this method is useful to detect extracellular proteases produced by both fungi as well as bacteria. The method used in the present study is sensitive, and can be easily performed for screening of large number of microbial cultures. This is the first report on the use of tannic acid for the detection of microbial proteases.

  12. Simulation of Bacillus subtilis biofilm growth on agar plate by diffusion-reaction based continuum model.

    PubMed

    Zhang, Xianlong; Wang, Xiaoling; Nie, Kai; Li, Mingpeng; Sun, Qingping

    2016-01-01

    Various species of bacteria form highly organized spatially-structured aggregates known as biofilms. To understand how microenvironments impact biofilm growth dynamics, we propose a diffusion-reaction continuum model to simulate the formation of Bacillus subtilis biofilm on an agar plate. The extended finite element method combined with level set method are employed to perform the simulation, numerical results show the quantitative relationship between colony morphologies and nutrient depletion over time. Considering that the production of polysaccharide in wild-type cells may enhance biofilm spreading on the agar plate, we inoculate mutant colony incapable of producing polysaccharide to verify our results. Predictions of the glutamate source biofilm's shape parameters agree with the experimental mutant colony better than that of glycerol source biofilm, suggesting that glutamate is rate limiting nutrient for Bacillus subtilis biofilm growth on agar plate, and the diffusion-limited is a better description to the experiment. In addition, we find that the diffusion time scale is of the same magnitude as growth process, and the common-employed quasi-steady approximation is not applicable here. PMID:27434099

  13. Alternative plasticizers for the production of thermo-compressed agar films.

    PubMed

    Sousa, Ana M M; Souza, Hiléia K S; Liu, LinShu; Gonçalves, Maria P

    2015-05-01

    Agar films were produced by thermo-compression using choline chloride (ChCl) as a plasticizer with urea. The three solid components were mixed together with the salt and urea (minor components) added to agar (main component) according to a fixed mass ratio of, respectively, 1.16:1:5. A central composite rotatable design (CCRD) with three parameters, 2(3), was used to evaluate the effects of temperature (X1; °C), time (X2; min) and applied load (X3; kN) of heat-pressing on the maximum tensile strength (TS) of the films (Y; MPa). Mixtures of urea and agar prepared at a mass ratio of 1:5 did not form homogeneous films suggesting the important plasticizing role of the salt. Heat-pressing the mixtures at more draconian conditions led to much darker and opaque films, with better mechanical resistance (higher values of TS). The most resistant film (∼ 15 MPa) was obtained at 140°C, 20 min and 176 kN. Selected films, including the optimal, showed similar water sorption profiles and close values of water vapor permeability (∼ 2.5-3.7 × 10(-9)gm(-1)s(-1)Pa(-1)). The fracture behavior and mechanical properties of the films were greatly affected by additional water plasticization when the films were stored at different conditions of relative humidity. PMID:25727746

  14. Simulation of Bacillus subtilis biofilm growth on agar plate by diffusion-reaction based continuum model

    NASA Astrophysics Data System (ADS)

    Zhang, Xianlong; Wang, Xiaoling; Nie, Kai; Li, Mingpeng; Sun, Qingping

    2016-08-01

    Various species of bacteria form highly organized spatially-structured aggregates known as biofilms. To understand how microenvironments impact biofilm growth dynamics, we propose a diffusion-reaction continuum model to simulate the formation of Bacillus subtilis biofilm on an agar plate. The extended finite element method combined with level set method are employed to perform the simulation, numerical results show the quantitative relationship between colony morphologies and nutrient depletion over time. Considering that the production of polysaccharide in wild-type cells may enhance biofilm spreading on the agar plate, we inoculate mutant colony incapable of producing polysaccharide to verify our results. Predictions of the glutamate source biofilm’s shape parameters agree with the experimental mutant colony better than that of glycerol source biofilm, suggesting that glutamate is rate limiting nutrient for Bacillus subtilis biofilm growth on agar plate, and the diffusion-limited is a better description to the experiment. In addition, we find that the diffusion time scale is of the same magnitude as growth process, and the common-employed quasi-steady approximation is not applicable here.

  15. Application of solid-phase extraction to agar-supported fermentation.

    PubMed

    Le Goff, Géraldine; Adelin, Emilie; Cortial, Sylvie; Servy, Claudine; Ouazzani, Jamal

    2013-09-01

    Agar-supported fermentation (Ag-SF), a variant of solid-state fermentation, has recently been improved by the development of a dedicated 2 m(2) scale pilot facility, Platotex. We investigated the application of solid-phase extraction (SPE) to Ag-SF in order to increase yields and minimize the contamination of the extracts with agar constituents. The selection of the appropriate resin was conducted on liquid-state fermentation and Diaion HP-20 exhibited the highest recovery yield and selectivity for the metabolites of the model fungal strains Phomopsis sp. and Fusarium sp. SPE applied to Ag-SF resulted in a particular compartmentalization of the culture. The mycelium that requires oxygen to grow migrates to the top layer and formed a thick biofilm. The resin beads intercalate between the agar surface and the mycelium layer, and trap directly the compounds secreted by the mycelium through a "solid-solid extraction" (SSE) process. The resin/mycelium layer is easily recovered by scraping the surface and the target metabolites extracted by methanol. Ag-SF associated to SSE represents an ideal compromise for the production of bioactive secondary metabolites with limited economic and environmental impact.

  16. N-acetylgalatosamine-Mediated Regulation of the aga Operon by AgaR in Streptococcus pneumoniae

    PubMed Central

    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 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. PMID:27672623

  17. New agar microspheres for the separation and purification of natural products.

    PubMed

    Ge, Chunling; Hu, Yu; Zhang, Fan; Lv, Yongqin; Tan, Tianwei

    2014-11-01

    A new type of agar chromatography media has been prepared with a yield over 80% using a water-in-oil emulsion technique. These microspheres have regular spherical shapes and particle diameters in the range 40-165 μm (average ∼90 μm). Cross-linking of the resulting agar microspheres with epichlorohydrin and 1,4-butanediol diglycidyl ether enhanced their mechanical and thermal stability. The alkaline conditions used during the cross-linking reaction also decreased the content of ionized sulfate groups of the polysaccharide, thus reducing the nonspecific adsorption of positively charged molecules. The cross-linked agar microspheres were functionalized with (i) branched poly(ethyleneimine) to obtain a stationary phase useful for the separation of proteins in an anion-exchange mode and (ii) with poly-β-cyclodextrin enabling direct isolation and purification of puerarin from a crude extract of Radix puerariae. Using a 23.5 mL column loaded with 20 mg extract (0.85 mg/mL gel), puerarin with a purity of 96% was recovered with a yield of 86%.

  18. AgarTrap-mediated genetic transformation using intact gemmae/gemmalings of the liverwort Marchantia polymorpha L.

    PubMed

    Tsuboyama-Tanaka, Shoko; Kodama, Yutaka

    2015-03-01

    The dioecious liverwort, Marchantia polymorpha L., is an emerging model plant. Various molecular biological techniques have been optimized for M. polymorpha for the past several years, and recently we reported a simplified Agrobacterium-mediated transformation method using sporelings (immature thalli from spores) of M. polymorpha. This method, termed AgarTrap (Agar-utilized Transformation with Pouring Solutions), completed by exchanging appropriate solutions on a single Petri dish to produce a sufficient number of independent transgenic sporelings. However, because spores are produced by crosses between males and females, the genetic backgrounds of resulting transgenic sporelings are not uniform. To easily produce transgenic liverworts with a uniform genetic background using AgarTrap, we developed an AgarTrap-mediated transformation method using intact gemmae/gemmalings produced by asexual reproduction. Using AgarTrap with male and female gemmae/gemmalings produced a sufficient number of independent transgenic gemmalings with uniform genetic backgrounds. The optimized transformation efficiencies were approximately 30 and 50 % in males and females, respectively. As with AgarTrap using sporelings, AgarTrap using intact gemmae/gemmalings will be useful in promoting studies of the molecular biology of M. polymorpha. PMID:25663453

  19. Performance of Candida ID, a New Chromogenic Medium for Presumptive Identification of Candida Species, in Comparison to CHROMagar Candida

    PubMed Central

    Willinger, Birgit; Hillowoth, Cornelia; Selitsch, Brigitte; Manafi, Mammad

    2001-01-01

    Candida ID agar allows identification of Candida albicans and differentiation of other Candida species. In comparison with CHROMagar Candida, we evaluated the performance of this medium directly from 596 clinical specimens. In particular, detection of C. albicans after 24 h of incubation was easier on Candida ID (sensitivity, 96.8%) than on CHROMagar (sensitivity, 49.6%). PMID:11574621

  20. Isolation of Clostridium difficile from faecal specimens--a comparison of chromID C. difficile agar and cycloserine-cefoxitin-fructose agar.

    PubMed

    Carson, Kerry C; Boseiwaqa, Lusiana V; Thean, Sara K; Foster, Niki F; Riley, Thomas V

    2013-09-01

    The culture of toxigenic Clostridium difficile from stool specimens is still seen as the gold standard for the laboratory diagnosis of C. difficile infection (CDI). bioMérieux have released ChromID Cdiff chromogenic agar (CDIF) for the isolation and identification of C. difficile in 24 h. In this study, we compared CDIF to pre-reduced cycloserine-cefoxitin-fructose agar with sodium taurocholate (TCCFA) in the examination of glutamate dehydrogenase-positive faecal specimens that were either GeneOhm positive or negative, using direct culture or culture following alcohol shock. Direct culture on CDIF had a sensitivity of 100 % and recovery of 94 % while for TCCFA these were 87 % and 82 %, respectively. For GeneOhm-positive alcohol-shocked faecal samples, sensitivity and recovery on CDIF was similar to direct culture while on TCCFA they were about 10 % higher. For direct culture, there was a significant difference between growth on CDIF at 24 h and TCCFA at 48 h (P = 0.001) and between the two media at 48 h (P<0.001). A total of 142 strains of C. difficile were recovered in pure culture from all GeneOhm-positive samples used in this study and 11 (7.7 %) of these were A(-)B(-)CDT(-) and may represent mixed infections of toxigenic and non-toxigenic C. difficile. The most dominant ribotype was UK 014 (14.7 %) followed by 002 (11.9 %) and 020 (11.9 %), and 36 % of toxigenic isolates, including an A(-)B(+)CDT(-) strain, could not be assigned a UK ribotype. CDIF outperformed pre-reduced TCCFA by negating the need for alcohol shock treatment and by giving a time saving of 24 h in the isolation of C. difficile. CDIF plates were also more selective than TCCFA and C. difficile colonies were easy to identify and subculture prior to strain typing.

  1. Comparison of Sorbitol MacConkey Agar and a Two-Step Method Which Utilizes Enzyme-Linked Immunosorbent Assay Toxin Testing and a Chromogenic Agar To Detect and Isolate Enterohemorrhagic Escherichia coli

    PubMed Central

    Novicki, Thomas J.; Daly, Judy A.; Mottice, Susan L.; Carroll, Karen C.

    2000-01-01

    Enterohemorrhagic Escherichia coli (EHEC) and specifically serotype O157:H7 are a significant cause of hemorrhagic gastrointestinal disease and the hemolytic uremic syndrome. Methods currently used in clinical microbiology labs, such as sorbitol-MacConkey (SMAC) agar, reliably detect only O157:H7. We have evaluated a two-step method that has the potential to identify and isolate all EHEC serotypes, including serotype O157:H7. This method utilizes a chromogenic selective-differential medium for the isolation of E. coli together with an enzyme-linked immunosorbent assay (ELISA) that detects the Shiga-like toxins Stx1 and Stx2. Both are commercially available and usable in a wide range of clinical microbiology laboratories. Compared to a Vero cell cytotoxic assay, SMAC had sensitivities of 23.5% for the identification of all EHEC serotypes and of 50.0% for the identification of O157:H7 alone. The two-step method had sensitivities of 76.5 and 100%, respectively. The ELISA alone had a sensitivity of 82.4% in the detection of Stx1 and Stx2. The specificity was 100% in all cases. Overall, 14 EHEC isolates were obtained: 8 (58%) O157:H7, 2 (14%) O26, 2 (14%) O111:NM, 1 (7%) O103:H2, and 1 (7%) O121:H19. All but one were isolated during the months of May to September. The two-step method was found to be considerably more expensive than SMAC for both positive and negative samples. PMID:10655343

  2. Emerging Supplements in Sports

    PubMed Central

    Mason, Bryan C.; Lavallee, Mark E.

    2012-01-01

    Context: Nutritional supplements advertised as ergogenic are commonly used by athletes at all levels. Health care professionals have an opportunity and responsibility to counsel athletes concerning the safety and efficacy of supplements on the market. Evidence Acquisition: An Internet search of common fitness and bodybuilding sites was performed to identify supplement promotions. A search of MEDLINE (2000–August, 2011) was performed using the most commonly identified supplements, including glutamine, choline, methoxyisoflavone, quercetin, zinc/magnesium aspartate, and nitric oxide. The search terms supplement, ergogenic aid, and performance were also used. Results: Six common and newer supplements were identified, including glutamine, choline, methoxyisoflavone, quercetin, zinc/magnesium aspartate, and nitric oxide. Conclusions: Controlled studies have not determined the effects of these supplements on performance in athletes. Scientific evidence is not available to support the use of these supplements for performance enhancement. PMID:23016081

  3. Multivitamin/Mineral Supplements

    MedlinePlus

    ... Nutrient recommendations: Dietary Reference Intakes (DRI) Online DRI tool Daily Value (DV) tables For more advice on buying dietary supplements: Office of Dietary Supplements Frequently Asked Questions: Which brand(s) ...

  4. A Selective Medium and a Specific Probe for Detection of Vibrio vulnificus

    PubMed Central

    Cerdà-Cuéllar, Marta; Jofre, Joan; Blanch, Anicet R.

    2000-01-01

    A selective medium (VVM) and a specific 16S rRNA gene (rDNA) probe (V3VV) for the detection of Vibrio vulnificus were developed. The medium contains d-(+)-cellobiose as the main carbon source and electrolytes (MgCl2-6H2O and KCl), which stimulate bacterial growth. Polymyxin B, colistin, and moderate alkalinity and salinity provide selectivity properties. V. vulnificus grows on VVM as flat, bright yellow colonies. Other Vibrio species tested either did not grow or showed green-bluish colonies, with the exception of V. campbelli, V. carchariae, and V. navarrensis. There is a higher colony count on VVM agar than on cellobiose-colistin agar or on modified cellobiose-polymyxin B-colistin agar. The specific probe was evaluated by colony hybridization and dot blot hybridization with PCR-amplified 16S rDNA using collection strains and environmental isolates. No strain studied other than V. vulnificus showed positive hybridization with this oligonucleotide. The combined use of VVM agar and the V3VV probe provided the recovery of V. vulnificus from mixed bacterial suspensions and spiked mussels. PMID:10653765

  5. Preparation of an agar-silver nanoparticles (A-AgNp) film for increasing the shelf-life of fruits.

    PubMed

    Gudadhe, Janhavi A; Yadav, Alka; Gade, Aniket; Marcato, Priscyla D; Durán, Nelson; Rai, Mahendra

    2014-12-01

    Preparation of protective coating possessing antimicrobial properties is present day need as they increase the shelf life of fruits and vegetables. In the present study, preparation of agar-silver nanoparticle film for increasing the shelf life of fruits is reported. Silver nanoparticles (Ag-NPs) biosynthesised using an extract of Ocimum sanctum leaves, were mixed with agar-agar to prepare an agar-silver nanoparticles (A-AgNp) film. This film was surface-coated over the fruits, Citrus aurantifolium (Thornless lime) and Pyrus malus (Apple), and evaluated for the determination of antimicrobial activity of A-AgNp films using disc diffusion method, weight loss and shelf life of fruits. This study demonstrates that these A-AgNp films possess antimicrobial activity and also increase the shelf life of fruits. PMID:25429496

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

    PubMed

    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.

  7. Trace Amounts of Furan-2-Carboxylic Acids Determine the Quality of Solid Agar Plates for Bacterial Culture

    PubMed Central

    Hara, Shintaro; Isoda, Reika; Tahvanainen, Teemu; Hashidoko, Yasuyuki

    2012-01-01

    Background Many investigators have recognised that a significant proportion of environmental bacteria exist in a viable but non-culturable state on agar plates, and some researchers have also noticed that some of such bacteria clearly recover their growth on matrices other than agar. However, the reason why agar is unsuitable for the growth of some bacteria has not been addressed. Methodology/Principal Findings According to the guide of a bioassay for swarming inhibition, we identified 5-hydroxymethylfuran-2-carboxylic acid (5-HMFA) and furan-2-carboxylic acid (FA) as factors that inhibit bacterial swarming and likely inhibit extracellular polysaccharide production on agar. The furan-2-carboxylic acids 5-HMFA and FA effectively inhibited the swarming and swimming of several environmental bacteria at concentrations of 1.8 and 2.3 µg L−1 (13 and 21 nmol L−1), respectively, which are equivalent to the concentrations of these compounds in 0.3% agar. On Luria-Bertani (LB) plates containing 1.0% agar that had been previously washed with MeOH, a mixture of 5-HMFA and FA in amounts equivalent to their original concentrations in the unwashed agar repressed the swarming of Escherichia coli K12 strain W3110, a representative swarming bacterium. Conclusions/Significance Agar that contains trace amounts of 5-HMFA and FA inhibits the proliferation of some slow-growing or difficult-to-culture bacteria on the plates, but it is useful for single colony isolation due to the ease of identification of swarmable bacteria as the non-swarmed colonies. PMID:22848437

  8. Evaluation of Bio-Rad MRSASelect agar for detection of methicillin-resistant Staphylococcus aureus directly from blood cultures.

    PubMed

    Riedel, Stefan; Dam, Lisa; Stamper, Paul D; Shah, Syed A R; Carroll, Karen C

    2010-06-01

    MRSASelect agar (Bio-Rad, Redmond, WA) was evaluated for its performance in detecting MRSA directly from positive blood cultures containing Gram-positive cocci in clusters. Agar plates were evaluated for the presence of pink colonies at 18 to 24 h. Results were compared to organism identification by using standard laboratory methods. Confirming coagulase on pink isolates, the sensitivity and specificity were both 99%.

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

    PubMed Central

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

    2002-01-01

    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 log2 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 log2 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 μg/ml (control) to 2.0 μg/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, good

  10. Cavitation-enhanced delivery of insulin in agar and porcine models of human skin.

    PubMed

    Feiszthuber, Helga; Bhatnagar, Sunali; Gyöngy, Miklós; Coussios, Constantin-C

    2015-03-21

    Ultrasound-assisted transdermal insulin delivery offers a less painful and less invasive alternative to subcutaneous insulin injections. However, ultrasound-based drug delivery, otherwise known as sonophoresis, is a highly variable phenomenon, in part dependent on cavitation. The aim of the current work is to investigate the role of cavitation in transdermal insulin delivery. Fluorescently stained, soluble Actrapid insulin was placed on the surface of human skin-mimicking materials subjected to 265 kHz, 10% duty cycle focused ultrasound. A confocally and coaxially aligned 5 MHz broadband ultrasound transducer was used to detect cavitation. Two different skin models were used. The first model, 3% agar hydrogel, was insonated with a range of pressures (0.25-1.40 MPa peak rarefactional focal pressure-PRFP), with and without cavitation nuclei embedded within the agar at a concentration of 0.05% w/v. The second, porcine skin was insonated at 1.00 and 1.40 MPa PRFP. In both models, fluorescence measurements were used to determine penetration depth and concentration of delivered insulin. Results show that in agar gel, both insulin penetration depth and concentration only increased significantly in the presence of inertial cavitation, with up to a 40% enhancement. In porcine skin the amount of fluorescent insulin was higher in the epidermis of those samples that were exposed to ultrasound compared to the control samples, but there was no significant increase in penetration distance. The results underline the importance of instigating and monitoring inertial cavitation during transdermal insulin delivery. PMID:25716689

  11. Cavitation-enhanced delivery of insulin in agar and porcine models of human skin

    NASA Astrophysics Data System (ADS)

    Feiszthuber, Helga; Bhatnagar, Sunali; Gyöngy, Miklós; Coussios, Constantin-C.

    2015-03-01

    Ultrasound-assisted transdermal insulin delivery offers a less painful and less invasive alternative to subcutaneous insulin injections. However, ultrasound-based drug delivery, otherwise known as sonophoresis, is a highly variable phenomenon, in part dependent on cavitation. The aim of the current work is to investigate the role of cavitation in transdermal insulin delivery. Fluorescently stained, soluble Actrapid insulin was placed on the surface of human skin-mimicking materials subjected to 265 kHz, 10% duty cycle focused ultrasound. A confocally and coaxially aligned 5 MHz broadband ultrasound transducer was used to detect cavitation. Two different skin models were used. The first model, 3% agar hydrogel, was insonated with a range of pressures (0.25-1.40 MPa peak rarefactional focal pressure—PRFP), with and without cavitation nuclei embedded within the agar at a concentration of 0.05% w/v. The second, porcine skin was insonated at 1.00 and 1.40 MPa PRFP. In both models, fluorescence measurements were used to determine penetration depth and concentration of delivered insulin. Results show that in agar gel, both insulin penetration depth and concentration only increased significantly in the presence of inertial cavitation, with up to a 40% enhancement. In porcine skin the amount of fluorescent insulin was higher in the epidermis of those samples that were exposed to ultrasound compared to the control samples, but there was no significant increase in penetration distance. The results underline the importance of instigating and monitoring inertial cavitation during transdermal insulin delivery.

  12. Cavitation-enhanced delivery of insulin in agar and porcine models of human skin.

    PubMed

    Feiszthuber, Helga; Bhatnagar, Sunali; Gyöngy, Miklós; Coussios, Constantin-C

    2015-03-21

    Ultrasound-assisted transdermal insulin delivery offers a less painful and less invasive alternative to subcutaneous insulin injections. However, ultrasound-based drug delivery, otherwise known as sonophoresis, is a highly variable phenomenon, in part dependent on cavitation. The aim of the current work is to investigate the role of cavitation in transdermal insulin delivery. Fluorescently stained, soluble Actrapid insulin was placed on the surface of human skin-mimicking materials subjected to 265 kHz, 10% duty cycle focused ultrasound. A confocally and coaxially aligned 5 MHz broadband ultrasound transducer was used to detect cavitation. Two different skin models were used. The first model, 3% agar hydrogel, was insonated with a range of pressures (0.25-1.40 MPa peak rarefactional focal pressure-PRFP), with and without cavitation nuclei embedded within the agar at a concentration of 0.05% w/v. The second, porcine skin was insonated at 1.00 and 1.40 MPa PRFP. In both models, fluorescence measurements were used to determine penetration depth and concentration of delivered insulin. Results show that in agar gel, both insulin penetration depth and concentration only increased significantly in the presence of inertial cavitation, with up to a 40% enhancement. In porcine skin the amount of fluorescent insulin was higher in the epidermis of those samples that were exposed to ultrasound compared to the control samples, but there was no significant increase in penetration distance. The results underline the importance of instigating and monitoring inertial cavitation during transdermal insulin delivery.

  13. Compatible fungi, suitable medium, and appropriate developmental stage essential for stable association of Dendrobium chrysanthum.

    PubMed

    Hajong, Subarna; Kumaria, Suman; Tandon, Pramod

    2013-12-01

    Establishment of symbiotic association at the appropriate developmental stage helped maintain continued growth which is vital for the long-term ex vitro survival of the orchid. In the present study, symbiotic association was carried out using different developmental stages of Dendrobium chrysanthum and pathogenic Rhizoctonia isolates (obtained from orchids and non-orchid hosts) in different culture media. Isolate 2162 supported highest symbiotic germination on OMA-S (oat meal agar medium without nutrients + sucrose), whereas, stable symbiotic association with plantlets was obtained with isolate 4634 on OMA-NC (oat meal agar medium + cellulose). Isolate Dc-2S2 obtained from the host plant did not promote seed germination nor did it form association with protocorms or plantlets. This study, for the first time identifies a combination of compatible fungal isolate, suitable culture medium, and appropriate developmental stage at which symbiotic association in vitro can be deemed successful for the medicinally important orchid, D. chrysanthum.

  14. Study of gelatin-agar intermolecular aggregates in the supernatant of its coacervate.

    PubMed

    Singh, S Santinath; Bohidar, H B; Bandyopadhyay, S

    2007-05-15

    Intermolecular interaction leading to formation of aggregates between gelatin, a polyampholyte, and agar, a polysaccharide was studied in the supernatant of the complex coacervate formed by these biopolymers. Electrophoresis, laser light scattering and viscometry data were used to determine the interaction and the physical structure of these intermolecular soluble complexes by modeling these to be prolate ellipsoids of revolution (rod-like structures with well defined axial ratio and Perrin's factor). Solution ionic strength was found to reduce the axial ratio of these complexes implying the presence of screened polarization-induced electrostatic interaction between the two biopolymers.

  15. Comparative study of 6-APA production by free and agar immobilized bacteria in nutrient broth culture.

    PubMed

    Dolui, A K; Das, S

    2011-04-01

    In the present study different bacterial samples were isolated from soil of different places of Dibrugarh and screened for biotransformation ability to produce 6-Aminopenicillanic acid. Among ten isolated bacterial samples, three gram positive bacterial samples designated as AKDD-2, AKDD-4 and AKDD-6 showed the production of 6-APA from penicillin G. Assessment of production of 6-APA after incubation in penicillin G (2 mg/ml) by three different samples separately in free and agar immobilization state was done by HPLC analysis. Reusability of immobilized cells was found successful up to 14 days. PMID:21614893

  16. Comparative study of 6-APA production by free and agar immobilized bacteria in nutrient broth culture.

    PubMed

    Dolui, A K; Das, S

    2011-04-01

    In the present study different bacterial samples were isolated from soil of different places of Dibrugarh and screened for biotransformation ability to produce 6-Aminopenicillanic acid. Among ten isolated bacterial samples, three gram positive bacterial samples designated as AKDD-2, AKDD-4 and AKDD-6 showed the production of 6-APA from penicillin G. Assessment of production of 6-APA after incubation in penicillin G (2 mg/ml) by three different samples separately in free and agar immobilization state was done by HPLC analysis. Reusability of immobilized cells was found successful up to 14 days.

  17. Synthetic laser medium

    DOEpatents

    Stokowski, Stanley E.

    1989-01-01

    A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chormium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.

  18. Synthetic laser medium

    DOEpatents

    Stokowski, S.E.

    1987-10-20

    A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chromium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.

  19. Selective Medium for Recovering Specific Populations of Rhizobia Introduced into Tropical Soils †

    PubMed Central

    Habte, Mitiku

    1985-01-01

    Experiments were designed to evaluate the usefulness of antifungal agents and streptomycin for recovering low densities of rhizobia inoculated into tropical soils. The results showed that yeast-mannitol agar (pH 6.0) containing 500 μg of streptomycin, 400 μg of cycloheximide and 50 μg of benomyl or chlorothalonil per ml was the best selective medium. PMID:16346957

  20. Chemically defined medium enhances bioelectric activity in mouse spinal cord-dorsal root ganglion cultures.

    PubMed

    Habets, A M; Baker, R E; Brenner, E; Romijn, H J

    1981-02-23

    Co-cultures of mouse spinal cord with dorsal root ganglion (DRG) cultures were grown either in horse serum (HS)-supplemented medium or in a serum-free, chemically defined medium (CDM). The cytoarchitecture of cord--DRG explants was fully retained in CDM, with little or no distortion due to flattening of the explant, as is invariably observed in HS-supplemented cultures. Functional properties such as bioelectric activity and DRG--spinal cord interconnectivity were well sustained in CDM.

  1. Influence of nutritional supplements on keratinolysis by Amycolatopsis keratinophila.

    PubMed

    Al-Musallam, A A; Al-Zarban, S S; Al-Sarawi, H K; Kroppenstedt, R M; Stackebrandt, E; Fasasi, Y A

    2003-08-01

    Keratinolytic potential of A. keratinophila (DSM 44409T), a newly described Amycolatopsis sp. isolated from cultivated soil in Kuwait, was demonstrated using keratinazure as the sole source of carbon and nitrogen as estimated by gel diffusion assay. Effects of 12 various nutritional supplements on the keratinolytic and azocollytic activities were determined. NH4H2PO4 and KNO3 in the medium supported a significantly higher keratinolytic activity than other supplements. However, azocollytic activities in all the supplemented media and the control were same. Best combination of carbon and nitrogen supplements (galactose and NH4H2PO4 respectively) used to evaluate the dynamics of growth and enzymes (keratinase and protease) activities of the isolate revealed a luxuriant growth with optimal keratinolytic activity occurring during the log phase. Other parameters of the fermentation medium, including pH, biomass accumulation, total protein and free amino acid concentrations were also studied.

  2. Comparison of a novel MPN method against the yeast extract agar (YEA) pour plate method for the enumeration of heterotrophic bacteria from drinking water.

    PubMed

    Sartory, David P; Gu, Haoyi; Chen, Chun-Ming

    2008-07-01

    This study compared the Quanti-Disc most probable number (MPN) test for heterotrophic bacteria from drinking water with the widely used yeast extract agar (YEA) pour plate method. The Quanti-Disc test module contains 50 reaction wells in which a medium has been pre-deposited. The medium contains a suite of three fluorogenic enzyme substrates selected for the detection of enzymes expressed widely by heterotrophic bacteria. The MPN of heterotrophic bacteria is calculated from the number of fluorescing reaction wells after incubation of a sample. Quanti-Disc and the YEA pour plate method were compared according to guidance on comparing methods given in United Kingdom national guidance and ISO 17994:2004. The two methods were also challenged with reference strains and isolates of heterotrophic bacteria from drinking water. This indicated that heterotrophic bacteria commonly encountered in drinking water are detected by both the YEA pour plate method and Quanti-Disc. Analysis of data from split water samples (723 for 37 degrees C tests and 872 for 22 degrees C tests) from nine geographically diverse laboratories in England and Wales demonstrated that the Quanti-Disc method is equivalent to the YEA pour plate method for the analysis of heterotrophic bacteria from drinking and similar waters at 37 degrees C, and superior to YEA for the analysis at 22 degrees C. The Quanti-Disc method is a simple and efficient alternative method for the enumeration of heterotrophic bacteria from drinking water.

  3. Measuring Survival of Hematopoietic Cancer Cells with the Colony-Forming Assay in Soft Agar.

    PubMed

    Crowley, Lisa C; Waterhouse, Nigel J

    2016-01-01

    Colony-forming assays measure the ability of cells in culture to grow and divide into groups. Any cell that has the potential to form a colony may also have the potential to cause cancer or relapse in vivo. Colony-forming assays also provide an indirect measurement of cell death because any cell that is dead or dying will not continue to proliferate. The proliferative capacity of adherent cells such as fibroblasts can be determined by growing cells at low density on culture dishes and counting the number of distinct groups that form over time. Cells that grow in suspension, such as hematopoietic cells, cannot be assayed this way because the cells move freely in the media. Assays to determine the colony-forming ability of hematopoietic cells must therefore be performed in solid matrices that restrict large-scale movement of the cells. One such matrix is soft agar. This protocol describes the use of soft agar to compare the colony-forming ability of untreated hematopoietic cells to the colony-forming ability of hematopoietic cells that have been treated with a cytotoxic agent. PMID:27480718

  4. An agar gel enzyme assay (AGEA) for simple detection of Salmonella enteritidis antibodies in chicken sera.

    PubMed

    Kim, C J; Nagaraja, K V

    1991-01-01

    An agar gel enzyme assay (AGEA) was developed for the detection of antibodies to Salmonella enteritidis (SE). The assay was based on the ability of antibodies to diffuse through an agar gel and react with antigen coated on a polystyrene surface. The antigen-antibody reaction was then made visible by applying an enzyme-conjugated anti-immunoglobulin and the addition, subsequently, of a substrate-containing gel. The color change in circular zones was taken as the indication for the presence of antibodies. The present investigation reports identification of an antigen specific for SE and its use in the development of a relatively simple AGEA procedure. The results of AGEA were compared with those of conventional microagglutination (MA) test and serum plate (SP) test. The percentage agreement between MA and AGEA in positive serum sample was found to be 94.4%, and in negative serum samples it was found to be 88.8%. The present results suggest that the AGEA could be a very useful screening test for the detection of SE antibodies because the assay is inexpensive, specific and simple to perform without much equipment, and give results within a 3-hr period. PMID:1832368

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

    PubMed

    Kim, Kyunghoon; Kim, Jung Kyung

    2015-01-01

    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. PMID:26343634

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

    PubMed Central

    Kim, Kyunghoon; Kim, Jung Kyung

    2015-01-01

    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. PMID:26343634

  7. Microcolonies in fluoroquinolone agar proportion susceptibility testing of Mycobacterium tuberculosis: an indicator of drug resistance

    PubMed Central

    Blackman, A.; May, S.; Devasia, R. A.; Maruri, F.; Stratton, C.

    2014-01-01

    Microcolony growth of Mycobacterium tuberculosis on agar proportion susceptibility testing is neither well-defined nor previously reported with fluoroquinolone susceptibility testing. We describe here M. tuberculosis microcolony growth with fluoroquinolones, and assess its clinical significance. We screened 797M. tuberculosis isolates for ofloxacin resistance (2.0 µg/mL) by agar proportion; 19 ofloxacin-resistant and 38 ofloxacin-susceptible isolates were selected for more detailed susceptibility testing with ofloxacin, ciprofloxacin, levofloxacin (all at 2.0 µg/mL) and moxifloxacin (0.5 µg/mL). The 57 isolates were also tested at two concentrations both above and below the critical concentrations. Microcolonies were defined as colonies 0.2–0.4 mm in diameter; confirmed microcolonies were present on repeat testing. Of the 57 isolates tested in detail, 7 grew microcolonies, of which 2 (0.3% of all isolates tested) had confirmed microcolonies on repeat testing (6 tests performed, and microcolonies were present on at least 4). Both M. tuberculosis isolates were ofloxacin-resistant on screening, and had ofloxacin minimum inhibitory concentration (MIC) >8 µg/mL. The five other isolates were ofloxacin-susceptible on screening, but had regular colony growth (i.e., resistance) at the drug concentration that initially resulted in microcolonies (ofloxacin 0.5 or 1.0 µg/mL). Microcolonies were observed infrequently with fluoroquinolone susceptibility testing, but when confirmed, they were associated with drug resistance. PMID:22322359

  8. Preparation and characterization agar-based nanocomposite film reinforced by nanocrystalline cellulose.

    PubMed

    Atef, Maryam; Rezaei, Masoud; Behrooz, Rabi

    2014-09-01

    Nanocrystalline cellulose (NCC) was prepared from microcrystalline cellulose (MCC) with particle size of 24.7 μm using sulfuric acid hydrolysis technique. The obtained NCC revealed size of 0-100 nm, which the major part of them was about 30 nm. Then different contents (2.5, 5 and 10 wt%) of these NCC incorporated in agar film solution and the morphology, structure, and properties of the nanocomposite films were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transforms infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), mechanical, physical and optical testing. Results showed that the water vapor permeability (WVP) and water solubility (WS) of the agar-based nanocomposite films significantly (P<0.05) decreased about 13% and 21%, respectively, upon increasing the NCC content to 10%. Tensile strength (TS) and Young's modulus (YM) values of nanocomposite films significantly increased (P≤0.05) with addition of NCC, whereas the elongation percent (E%) decreased not significantly (P>0.05). In addition, swelling percentage, transparency and light transmission of the films were decreased by incorporating NCC into polymer matrix.

  9. Volatile metabolite production of spoilage micro-organisms on a mixed-lettuce agar during storage at 7 degrees C in air and low oxygen atmosphere.

    PubMed

    Ragaert, P; Devlieghere, F; Devuyst, E; Dewulf, J; Van Langenhove, H; Debevere, J

    2006-11-01

    This paper describes the volatile metabolite production of spoilage bacteria (Pantoea agglomerans and Rahnella aquatilis) and spoilage yeasts (Pichia fermentans and Cryptococcus laurentii), previously isolated from mixed lettuce, on a simulation medium of shredded mixed lettuce (mixed-lettuce agar) both under air conditions and modified atmosphere (MA)-conditions at 7 degrees C. These latter conditions simulated the equilibrium modified atmosphere packaging, which is used to extend the shelf-life of shredded mixed lettuce. Besides volatile metabolites, organic acid metabolites and consumption of sugars were measured. Microbiological growth on the mixed-lettuce agar resulted in metabolite production and consumption of sugars. Bacteria and yeasts produced a range of volatile organic compounds both under air conditions and MA-conditions: ethanol, ethyl acetate, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2,3-butanedione, 3-methyl-1-pentanol, 1-butanol and 1-hexanol. Under MA-conditions, 2-methyl-1-butanol, 3-methyl-1-butanol and ethanol were the first compounds that were detected in the headspace as being produced by the inoculated micro-organisms. In the case of the yeast P. fermentans, production of these compounds was detected from a count of 5.0+/-0.1 log cfu/cm(2) with a fast increase when exceeding 6.0-6.5 log cfu/cm(2). Unlike P. fermentans, the yeast C. laurentii showed a slow metabolism under MA-conditions, compared to air conditions. In the case of the bacteria, production of 2-methyl-1-butanol and 3-methyl-1-butanol was detected starting from a count of 6.7+/-0.1 log cfu/cm(2) in the case of R. aquatilis and from a count of 7.1+/-0.4 log cfu/cm(2) in the case of P. agglomerans with a fast increase when exceeding 8 log cfu/cm(2). No production of ethanol by the bacteria under MA-conditions was detected in contradiction to air conditions. It could be concluded that, if these counts are reached on the cut surfaces of shredded mixed lettuce

  10. Growth of hybridoma cells in serum-free medium: ethanolamine is an essential component.

    PubMed Central

    Murakami, H; Masui, H; Sato, G H; Sueoka, N; Chow, T P; Kano-Sueoka, T

    1982-01-01

    A serum-free medium supplemented with a few growth factors was devised to grow lymphocyte hybridomas. The medium was developed with the hybridoma line MPC11-BL, a fusion product between a mouse plasmacytoma cell line (MPC11TG70na3) and mouse (BALB/c) spleen cells. In the process of developing the medium, ethanolamine was found to be an essential growth factor for the hybridoma. Phosphoethanolamine at 10-fold higher concentration could substitute for ethanolamine. Long-term cultivation of the cells was achieved in the defined medium supplemented with insulin, transferrin, ethanolamine, and selenium. The defined medium supported the growth of various other mouse hybridoma cell lines, mostly at a rate comparable to that observed in a serum-containing medium. After one-step ammonium sulfate precipitation of the spent medium, more than 95% of the protein recovered was immunoglobulin as shown by NaDodSO4/polyacrylamide gel electrophoresis. Images PMID:7041116

  11. A medium for the isolation, enumeration and rapid presumptive identification of injured Clostridium perfringens and Bacillus cereus.

    PubMed

    Hood, A M; Tuck, A; Dane, C R

    1990-09-01

    A blood-free egg yolk medium (BCP) containing pyruvate, inositol, mannitol and a bromocresol purple indicator in a nutrient agar base has been developed to initiate the growth of Clostridium perfringens. It is comparable to blood agar for the growth of normal, chilled stored vegetative cells and heat-injured spores of Cl. perfringens and Bacillus cereus. It has the advantage over blood agar in exhibiting presumptive evidence of Cl. perfringens (production of lecithinase and inositol fermentation) after an overnight incubation at 43 degrees - 45 degrees C. Pyruvate, catalase and other hydrogen peroxide degraders were found to remove toxins rapidly formed in media exposed to air and light. Free radical scavengers of superoxide, hydroxyl ions and singlet oxygen were ineffective. Without scavengers the formation of 10-20 micrograms/ml hydrogen peroxide in the exposed medium was indicated and found lethal to injured Cl. perfringens. The BCP medium has been used successfully for the rapid identification and enumeration of Cl. perfringens in foods and faeces from food poisoning outbreaks and cases of suspected infectious diarrhoea. Greater recovery of severely injured vegetative Cl. perfrigens could be obtained by pre-incubation at 37 degrees C of inoculated media for 2-4 h followed by overnight incubation at 43 degrees - 45 degrees C. Tryptose-sulphite-cycloserine and Shahidi-Ferguson-perfringens agar base were found to inhibit the growth of several strains of injured vegetative Cl. perfringens. This was not completely overcome by the addition of pyruvate. The inclusion of mannitol also allows the medium to be used for the presumptive identification of B. cereus. Growth and lecithinase activity are profuse on BCP. Heat-injured spores are recovered equally well on BCP and blood agar. A scheme for the identification of some other clostridia on BCP is presented.

  12. Susceptibility of a polycaprolactone-based root canal filling material to degradation using an agar-well diffusion assay

    PubMed Central

    Hiraishi, Noriko; Sadek, Fernanda T.; King, Nigel M.; Ferrari, Marco; Pashley, David H.; Tay, Franklin R

    2013-01-01

    Purpose Cholesterol esterase is both a component of salivary hydrolases as well as an inflammatory cell-derived enzyme and has been shown to cause biodegradation of methacrylate-based resin composites. This study examined whether Resilon, a polycaprolactone-based thermoplastic root filling material is susceptible to biodegradation by cholesterol esterase using agar-well diffusion assay of serially-diluted aqueous Resilon emulsions that were dispersed in agar. Materials and methods Emulsions of Resilon and polycaprolactone were prepared and dispersed in agar on culture plates. Two different concentrations of a cholesterol esterase (0.3 and 1.2 U/mL) were prepared and fed to wells prepared in the agar plates using an agar-well diffusion assay for examination the degradation of polymeric materials. Results Degradation of the emulsified Resilon was manifested as the formation of clear zones of different sizes around the agar wells. No clear zones were observed in agar wells that contain sterile distilled water as the negative control. Clinical significance Although dispersion Resilon into an emulsion is not the way in which this material is employed as a root filling material, the potential for Resilon to be degraded by cholesterol esterase is of potential concern as one cannot limit the degradation of extruded Resilon from a root apex by monocyte-derived macrophages to just the anatomical root apex. As the present study employed a high concentration of cholesterol esterase, further studies should be directed to examining the degradation of Resilon using macrophage cell cultures. PMID:18578181

  13. Thin stillage supplementation greatly enhances bacterial cellulose production by Gluconacetobacter xylinus.

    PubMed

    Wu, Jyh-Ming; Liu, Ren-Han

    2012-09-01

    Thin stillage (TS), a wastewater from rice wine distillery can well sustain the growth of Gluconacetobacter xylinus for production of bacterial cellulose (BC). When used as a supplement to the traditional BC production medium (Hestrin and Schramm medium), the enhancement of BC production increased with the amount of TS supplemented in a static culture of G. xylinus. When TS was employed to replace distilled water for preparing HS medium (100%TS-HS medium), the BC production in this 100%TS-HS medium was enhanced 2.5-fold to a concentration of 10.38 g/l with sugar to BC conversion yield of 57% after 7 days cultivation. The cost-free TS as a supplement in BC production medium not only can greatly enhance the BC production, but also can effectively dispose the nuisance wastewater of rice wine distillery.

  14. Infrared thermography analysis of thermal diffusion induced by RF magnetic field on agar phantoms loaded with magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Bante-Guerra, Jose; Macías, J. D.; Caballero-Aguilar, L.; Vales-Pinzón, C.; Alvarado-Gil, J. J.

    2013-02-01

    Recently, several treatments for fighting malignant tumors have been designed. However these procedures have well known inconveniences, depending on their applicability, tumor size and side effects, among others. Magnetic hyperthermia is a safe, non-invasive method for cancer therapy. This treatment is applied via elevation of target tissue temperature by dissipation of heat from Magnetic Nanoparticles (MNPs), previously located within the tumor. The induction of heat causes cell death and therefore the removal of the tumor. In this work the thermal diffusion in phantoms of agar loaded with magnetic nanoparticles (MNPs) is studied using the infrared thermography technique, which is widely used in biology/medicine (e.g. skin temperature mapping). Agar is one of the materials used to simulate different types of body tissues, these samples are known as "phantoms". Agar is of natural origin, low cost and high degree of biocompatibility. In this work the agar gel was embedded with MNPs by coprecipitation and placed in an alternating magnetic field radiation. As a consequence, the energy from the radiation source is dissipated as heat and then transferred from the MNP to the gel, increasing its temperature. For the temperature analysis, the samples of agar gel were stimulated by RF magnetic field generated by coils. Heating was measured with infrared thermography using a Thermovision A20M infrared camera. Thermographic images allowed obtaining the dependence of thermal diffusion in the phantom as a function of the magnitude of the applied RF magnetic field and the load of magnetic particles.

  15. Evaluation of chromogenic agar, [corrected] VITEK2 YST and VITEK® MS for identification of Candida strains isolated from blood cultures.

    PubMed

    Sariguzel, Fatma Mutlu; Berk, Elife; Koc, Ayse Nedret; Sav, Hafize; Aydemir, Gonca

    2015-12-01

    The aim of this study is to compare conventional methods, chromogenic agar, [corrected] VITEK2 YST card and VITEK®MS system for the identification of Candida strains isolated from blood cultures. Fifty-four strains were identified according to conventional methods, chromogenic agar, [corrected] VITEK2 YST card and VITEK®MS. Sequencing was used as the reference method. The 54 strains included 32 Candida parapsilosis, 19 Candida albicans, 1 Candida glabrata and 2 Candida tropicalis according to the reference method. One C. albicans and one C. glabrata isolate were misidentified as C. parapsilosis by chromogenic agar. [corrected]. Two C. parapsilosis and three C. albicans isolates were misidentified by VITEK2 YST card. Chromogenic agar, [corrected] VITEK2 YST card and VITEK®MS identified correctly 96.2%, 90.7% and 100% of all strains, respectively. We found that the chromogenic agar, [corrected] VITEK2 YST card and VITEK®MS system are easy, rapid and accurate alternative methods for the identification of yeast species in the clinical microbiology laboratory.

  16. Family Living Supplement.

    ERIC Educational Resources Information Center

    Truitt, Debbie

    This family living supplement contains 125 supplemental ideas and strategies designed to help vocational home economics teachers increase student motivation and enrich the teaching process. Ideas and strategies are organized into seven sections. These are career planning, securing a job, and career success; managing financial resources, buying…

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

    PubMed

    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.

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

    PubMed

    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. PMID:25462931

  19. In vitro fertilization and development of bovine oocytes matured in serum-free medium.

    PubMed

    Saeki, K; Hoshi, M; Leibfried-Rutledge, M L; First, N L

    1991-02-01

    This study was undertaken to investigate the effects of supplementation of serum (fetal calf serum), gonadotropins (LH, FSH, prolactin) and estradiol-17 beta (E2) to culture medium during in vitro maturation of bovine cumulus oocyte complexes on subsequent fertilization and development to the blastocyst stage in vitro. Serum supplementation during bovine oocyte maturation was not required but hormonal supplementation, gonadotropins (LH + FSH) and E2, enhanced the fertilizability and developmental ability of bovine oocytes matured in vitro. The addition of prolactin to maturation medium containing LH, FSH, and E2 did not further enhance frequencies of fertilization and development. PMID:2009327

  20. In vitro fertilization and development of bovine oocytes matured in serum-free medium.

    PubMed

    Saeki, K; Hoshi, M; Leibfried-Rutledge, M L; First, N L

    1991-02-01

    This study was undertaken to investigate the effects of supplementation of serum (fetal calf serum), gonadotropins (LH, FSH, prolactin) and estradiol-17 beta (E2) to culture medium during in vitro maturation of bovine cumulus oocyte complexes on subsequent fertilization and development to the blastocyst stage in vitro. Serum supplementation during bovine oocyte maturation was not required but hormonal supplementation, gonadotropins (LH + FSH) and E2, enhanced the fertilizability and developmental ability of bovine oocytes matured in vitro. The addition of prolactin to maturation medium containing LH, FSH, and E2 did not further enhance frequencies of fertilization and development.

  1. Agar-Like Polysaccharide Produced by a Pseudomonas Species: Production and Basic Properties

    PubMed Central

    Kang, Kenneth S.; Veeder, George T.; Mirrasoul, Peter J.; Kaneko, Tatsuo; Cottrell, Ian W.

    1982-01-01

    A new species of Pseudomonas was isolated that produced copious amounts of an exocellular heteropolysaccharide (PS-60) after incubation for 3 days at 30°C in media containing 3% glucose as a carbon source. The polysaccharide was composed of approximately 46% glucose and 30% rhamnose and, in addition, contained 21% uronic acid and 3% O-acetyl. Upon deacetylation by a mild alkaline treatment, PS-60 produced a brittle, firm, and optically clear gel. This gelling property was thermoreversible. The PS-60 gel exhibited excellent heat stability that withstood autoclaving (i.e., 121°C for 15 min) for several cycles. The gel strength, melting point, and setting point of the polysaccharide were controlled primarily by the concentration of cations. PS-60 was not affected by a variety of enzymes. The results of tests involving various culture media and biochemical test media indicate that PS-60 is an excellent alternative gelling agent to agar. PMID:16346007

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

    PubMed

    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.

  3. Serotyping reanalysis of unserotypable Actinobacillus pleuropneumoniae isolates by agar gel diffusion test

    PubMed Central

    MORIOKA, Ayako; SHIMAZAKI, Yoko; UCHIYAMA, Mariko; SUZUKI, Shoko

    2016-01-01

    We observed increasing unserotypable (UT) Actinobacillus pleuropneumoniae isolates using agar gel diffusion (AGD) test. To reanalyze their serovar, we performed rapid slide agglutination (RSA) test and multiplex PCR for 47 UT isolates. Of these, 25 were serovar 1 (UT-serovar 1), 20 were serovar 2 (UT-serovar 2) and 2 were serovar 15 (UT-serovar 15). We examined serotyping antigen extraction temperature to determine heat influence. UT-serovar 1 and 15 were influenced by heat, because their precipitation lines were observed in the case of low antigen extraction temperature. To investigate the relationship between antigenicity and genotype, we performed pulsed-field gel electrophoresis (PFGE) analysis using UT-serovar 2 and 15. The predominant PFGE pattern of UT-serovar 2 was identical to that of serovar 2. PMID:26726101

  4. Agar gel immunodiffusion assay to detect antibodies to Type A influenza virus.

    PubMed

    Jenson, Terra A

    2014-01-01

    The agar gel immunodiffusion (AGID) test is used to detect antibodies to Type A influenza group-specific antigens, i.e., the ribonucleoprotein (RNP) and matrix (M) proteins. Therefore, this test will detect antibodies to all influenza A virus subtypes. AGID is commonly used to screen poultry flocks for avian influenza virus infection. The AGID is a simple and economical serological test. All serological testing has its advantages and disadvantages which should be considered before choosing the optimal test for the laboratory needs. Each laboratory must evaluate the laboratory's resources, the volume of testing, the goal of testing, how the test results are used and what types of samples are being tested in order to select the optimal test.

  5. Bacterial culture detection and identification in blood agar plates with an optoelectronic nose.

    PubMed

    Lim, Sung H; Mix, Samantha; Anikst, Victoria; Budvytiene, Indre; Eiden, Michael; Churi, Yair; Queralto, Nuria; Berliner, Anders; Martino, Raymond A; Rhodes, Paul A; Banaei, Niaz

    2016-02-01

    Clinical microbiology automation is currently limited by the lack of an in-plate culture identification system. Using an inexpensive, printed, disposable colorimetric sensor array (CSA) responsive to the volatiles emitted into plate headspace by microorganisms during growth, we report here that not only the presence but the species of bacteria growing in plate was identified before colonies are visible. In 1894 trials, 15 pathogenic bacterial species cultured on blood agar were identified with 91.0% sensitivity and 99.4% specificity within 3 hours of detection. The results indicate CSAs integrated into Petri dish lids present a novel paradigm to speciate microorganisms, well-suited to integration into automated plate handling systems.

  6. Supplemental instruction in chemistry

    NASA Astrophysics Data System (ADS)

    Lundeberg, Mary A.

    This study was designed to measure some effects of supplemental instruction in chemistry. Supplemental instruction is a peer-led cooperative learning program that encourages students to develop conceptual understanding by articulating both understandings and misconceptions in a think-aloud fashion. Supplemental instruction was offered three hours weekly outside of class and lab time for students in four classes of General Organic and Biological Chemistry. Over a two-year period 108 students volunteered to participate in this program; 45 students did not participate. As measured by final grades in chemistry and responses to a questionnaire, supplemental instruction was effective in increasing students' achievement in chemistry. Further research is needed to determine the in-depth effects of supplemental instruction on students' learning, problem solving, and self-esteem.

  7. Evaluation of agar dilution and broth microdilution methods to determine the disinfectant susceptibility.

    PubMed

    Wu, Guoyan; Yang, Qianru; Long, Mei; Guo, Lijuan; Li, Bei; Meng, Yue; Zhang, Anyun; Wang, Hongning; Liu, Shuliang; Zou, Likou

    2015-11-01

    A variety of disinfectants have been widely used in veterinary hygiene, food industries and environments, which could induce the development of bacterial resistance to disinfectants. The methods used to investigate antimicrobial effects of disinfectant vary considerably among studies, making comparisons difficult. In this study, agar dilution and broth microdilution methods were used to compare the antimicrobial activities of four quaternary ammonium compounds (QACs) against foodborne and zoonotic pathogens. The potential relationship between the presence of QACs resistance genes and phenotypic resistance to QACs was also investigated. Our results indicated that the minimum inhibitory concentrations (MICs) determined by two methods might be different depended upon different QACs and bacteria applied. Regardless of the testing methods, Klebsiella pneumoniae was more tolerant among Gram-negative strains to four QACs, followed by Salmonella and Escherichia coli. The agreement between MICs obtained by the two methods was good, for benzalkonium chloride (78.15%), didecyldimethylammonium chloride (DDAC) (82.35%), cetylpyridinium chloride (CTPC) (97.48%) and cetyltrimethylammonium bromide (CTAB) (99.16%), respectively. Among all Gram-negative bacteria, 94.55% (n=52) of qacEΔ1-positive strains showed higher MICs (512 mg l(-1)) to CTAB. The qacEΔ1 gene was highly associated (P<0.05) with the high MICs of QACs (⩾512 mg l(-1)). In addition, DDAC remained as the most effective disinfectant against both Gram-positive and Gram-negative bacteria. This is the first study that compared the agar dilution and broth microdilution methods to assess the antimicrobial activity of QACs. The study demonstrated the need to standardize method that would be used in evaluating QACs antimicrobial properties in the future.

  8. AUTORADIOGRAPHIC ANALYSIS ON AGAR PLATES OF ANTIGENS FROM SUB CELLULAR FRACTIONS OF RAT LIVER SLICES

    PubMed Central

    Morgan, W. S.; Perlmann, P.; Hultin, T.

    1961-01-01

    Slices of rat livers were incubated with 14C amino acids, homogenized, and subjected to differential centrifugation. The microsomes were further extracted with the non-ionic detergent Lubrol W and with EDTA. These extracts and the microsome free "cell sap," freed from the pH 5 precipitable fraction, were subsequently reacted with antisera using agar diffusion techniques. The antisera employed were obtained from rabbits injected with different subcellular fractions of rat liver or with rat serum proteins. When the agar diffusion plates were autoradiographed it was found that some of the precipitates were radioactive while others were not. Control experiments indicated that this labeling was due to the specific incorporation of 14C amino acids into various rat liver antigens during incubation of the slices rather than to a non-specific adsorption of radioactive material to the immunological precipitates. When the slices were incubated with the isotope for up to 30 minutes, the serum proteins which could be extracted from the microsomes with the detergent were strongly labeled, as were a number of additional microsomal antigens of unknown significance. In contrast, the serum proteins present in the cell sap were only weakly labeled. Most of the typical cell sap proteins, both those precipitable and those soluble at pH 5, seemed to remain unlabeled. No consistently reproducible results were obtained with the EDTA extracts of the ribosomal residues remaining after extraction of the microsomes with the detergent. Incubation of the liver slices for longer periods (up to 120 minutes) led to a strong labeling of the serum proteins in the cell sap as well as to the appearance of labeling in additional cell sap proteins. The results are discussed with regard to the subcellular site of synthesis and the metabolism of the different antigens. PMID:13772607

  9. Evolutionary consequences of putative intra-and interspecific hybridization in agaric fungi.

    PubMed

    Hughes, Karen W; Petersen, Ronald H; Lodge, D Jean; Bergemann, Sarah E; Baumgartner, Kendra; Tulloss, Rodham E; Lickey, Edgar; Cifuentes, Joaquin

    2013-01-01

    Agaric fungi of the southern Appalachian Mountains including Great Smoky Mountains National Park are often heterozygous for the rDNA internal transcribed spacer region (ITS) with >42% of collections showing some heterozygosity for indels and/or base-pair substitutions. For these collections, intra-individual haplotype divergence is typically less than 2%, but for 3% of these collections intra-individual haplotype divergence exceeds that figure. We hypothesize that high intra-individual haplotype divergence is due to hybridization between agaric fungi with divergent haplotypes, possibly migrants from geographically isolated glacial refugia. Four species with relatively high haplotype divergence were examined: Armillaria mellea, Amanita citrina f. lavendula, Gymnopus dichrous and the Hygrocybe flavescens/chlorophana complex. The ITS region was sequenced, haplotypes of heterozygotes were resolved through cloning, and phylogenetic analyses were used to determine the outcome of hybridization events. Within Armillaria mellea and Amanita citrina f. lavendula, we found evidence of interbreeding and recombination. Within G. dichrous and H. flavescens/chlorophana, hybrids were identified but there was no evidence for F2 or higher progeny in natural populations suggesting that the hybrid fruitbodies might be an evolutionary dead end and that the genetically divergent Mendelian populations from which they were derived are, in fact, different species. The association between ITS haplotype divergence of less than 5% (Armillaria mellea = 2.6% excluding gaps; Amanita citrina f. lavendula = 3.3%) with the presence of putative recombinants and greater than 5% (Gymnopus dichrous = 5.7%; Hygrocybe flavescens/chlorophana = 14.1%) with apparent failure of F1 hybrids to produce F2 or higher progeny in populations may suggest a correlation between genetic distance and reproductive isolation. PMID:23928423

  10. Determination of agar tissue phantoms depth profiles with pulsed photothermal radiometry

    NASA Astrophysics Data System (ADS)

    Milanič, Matija; Majaron, Boris; Nelson, J. Stuart

    2007-07-01

    Pulsed photothermal radiometry (PPTR) can be used for non-invasive depth profiling of skin vascular lesions (e.g., port wine stain birthmarks), aimed towards optimizing laser therapy on an individual patient basis. Optimal configuration of the experimental setup must be found and its performance characterized on samples with well defined structure, before introducing the technique into clinical practice. The aim of our study is to determine how sample structure and width of spectruml acquisition band affect the accuracy of measured depth profiles. We have constructed tissue phantoms composed of multiple layers of agar and of thin absorbing layers between the agar layers. Three phantoms had a single absorber layer at various depths between 100 and 500 μm, and one phantom had two absorber layers. In each sample we induced a non-homogeneous temperature profile with a 585 nm pulsed laser and acquired the resulting radiometric signal with a fast InSb infrared camera. We tested two configurations of the acquisition system, one using the customary 3-5 um spectruml band and one with a custom 4.5 μm cut-on filter. The laser-induced temperature depth profiles were reconstructed from measured PPTR signals using a custom algorithm and compared with sample structure as determined by histology and optical coherent tomography (OCT). PPTR determined temperature profiles correlate well with sample structure in all samples. Determination of the absorbing layer depth shows good repeatability with spatial resolution decreasing with depth. Spectruml filtering improved the accuracy of reconstructed profiles for shallow absorption layers (100-200 μm). PPTR technique enables reliable determination of structure in tissue phantoms with thin absorbing layers. Narrowing of the spectruml acquisition band (to 4.5 - 5.3 μm) improves reconstruction of objects near the surface.

  11. Effect of bicarbonate concentration on aerobic growth of campylobacter in a fumarate-pyruvate medium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of the present study was to examine the effect of sodium bicarbonate (NaHCO3) concentration on aerobic growth of Campylobacter in a fumarate-pyruvate medium. Fumarate-pyruvate broth medium was supplemented with 0.00 to 0.10% NaHCO3 and inoculated with Campylobacter coli 33559, Campyloba...

  12. Mycobacterium and Aerobic Actinomycete Culture: Are Two Medium Types and Extended Incubation Times Necessary?

    PubMed Central

    Simner, Patricia J.; Doerr, Kelly A.; Steinmetz, Lory K.

    2016-01-01

    Mycobacterial cultures are historically performed using a liquid medium and a solid agar medium with an incubation period of up to 60 days. We performed a retrospective analysis of 21,494 mycobacterial and aerobic actinomycetes cultures performed over 10 months to determine whether two medium types remain necessary and to investigate whether culture incubation length can be shortened. Specimens were cultured using Bactec MGIT liquid medium and Middlebrook 7H11/S7H11 solid medium with incubation periods of 42 and 60 days, respectively. Time-to-positivity and the identity of isolates recovered from each medium were evaluated. A total of 1,205/21,494 cultures (6%) were positive on at least one medium. Of the 1,353 isolates recovered, 1,110 (82%) were nontuberculous mycobacteria, 145 (11%) were aerobic actinomycetes, and 98 (7%) were Mycobacterium tuberculosis complex. Assessing medium types, 1,121 isolates were recovered from solid medium cultures, 922 isolates were recovered from liquid medium cultures, and 690 isolates were recovered on both media. Liquid cultures were positive an average of 10 days before solid cultures when the two medium types were positive (P < 0.0001). Isolates detected on solid medium after 6 weeks of incubation included 65 (5%) nontuberculous mycobacteria, 4 (0.3%) aerobic actinomycetes, and 2 (0.2%) isolates from the M. tuberculosis complex. Medical chart review suggested that most of these later-growing isolates were insignificant, as the diagnosis was already known, or they were considered colonizers/contaminants. This study reaffirms the need for both liquid medium and solid medium for mycobacterial and aerobic actinomycetes culture and demonstrates that solid medium incubation times may be reduced to 6 weeks without significantly impacting sensitivity. PMID:26865689

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Growth and Pigment Production on d-Tryptophan Medium by Cryptococcus gattii, Cryptococcus neoformans, and Candida albicans▿

    PubMed Central

    Chaskes, Stuart; Frases, Susana; Cammer, Michael; Gerfen, Gary; Casadevall, Arturo

    2008-01-01

    Given the increasing prevalence of cryptococcosis caused by Cryptococcus gattii (serotypes B and C) strains, there is a need for rapid and reliable tests that discriminate C. gattii from Cryptococcus neoformans (serotypes A, D, and AD). Seventy-two C. neoformans strains, sixty-seven C. gattii strains, and five Candida albicans strains were analyzed for their ability to grow and produce pigment on minimal d-tryptophan d-proline (m-DTDP) medium, on yeast carbon base d-tryptophan d-proline (YCB-DTDP) medium, and on fructose d-tryptophan glycine (m-FDTG) medium. Of the C. gattii and C. neoformans isolates, 94% and 0% grew on m-DTDP agar, respectively, and 98% and 0% grew in YCB-DTDP medium, respectively. C. gattii produced large amounts of brown intracellular pigment(s) on m-DTDP agar and smaller amounts of yellow-brown (amber) extracellular pigment(s). C. albicans grew on both media and produced a pink photoactivated pigment on m-DTDP agar. C. gattii produced large amounts of brown intracellular pigments on the differential medium m-FDTG, whereas C. neoformans produced smaller amounts of the brown pigments and C. albicans produced a pink pigment. The pigments produced by C. gattii from d-tryptophan were distinct and were not related to melanin formation from 3,4-dihydroxyphenylalanine. Thin-layer chromatography of the methanol-extracted C. gattii cells detected four different pigments, including brown (two types), yellow, and pink-purple compounds. We conclude that tryptophan-derived pigments are not melanins and that growth on m-DTDP or YCB-DTDP agar can be used to rapidly differentiate C. gattii from C. neoformans. PMID:17989195

  15. Growth and pigment production on D-tryptophan medium by Cryptococcus gattii, Cryptococcus neoformans, and Candida albicans.

    PubMed

    Chaskes, Stuart; Frases, Susana; Cammer, Michael; Gerfen, Gary; Casadevall, Arturo

    2008-01-01

    Given the increasing prevalence of cryptococcosis caused by Cryptococcus gattii (serotypes B and C) strains, there is a need for rapid and reliable tests that discriminate C. gattii from Cryptococcus neoformans (serotypes A, D, and AD). Seventy-two C. neoformans strains, sixty-seven C. gattii strains, and five Candida albicans strains were analyzed for their ability to grow and produce pigment on minimal D-tryptophan D-proline (m-DTDP) medium, on yeast carbon base D-tryptophan D-proline (YCB-DTDP) medium, and on fructose D-tryptophan glycine (m-FDTG) medium. Of the C. gattii and C. neoformans isolates, 94% and 0% grew on m-DTDP agar, respectively, and 98% and 0% grew in YCB-DTDP medium, respectively. C. gattii produced large amounts of brown intracellular pigment(s) on m-DTDP agar and smaller amounts of yellow-brown (amber) extracellular pigment(s). C. albicans grew on both media and produced a pink photoactivated pigment on m-DTDP agar. C. gattii produced large amounts of brown intracellular pigments on the differential medium m-FDTG, whereas C. neoformans produced smaller amounts of the brown pigments and C. albicans produced a pink pigment. The pigments produced by C. gattii from D-tryptophan were distinct and were not related to melanin formation from 3,4-dihydroxyphenylalanine. Thin-layer chromatography of the methanol-extracted C. gattii cells detected four different pigments, including brown (two types), yellow, and pink-purple compounds. We conclude that tryptophan-derived pigments are not melanins and that growth on m-DTDP or YCB-DTDP agar can be used to rapidly differentiate C. gattii from C. neoformans.

  16. Growth and pigment production on D-tryptophan medium by Cryptococcus gattii, Cryptococcus neoformans, and Candida albicans.

    PubMed

    Chaskes, Stuart; Frases, Susana; Cammer, Michael; Gerfen, Gary; Casadevall, Arturo

    2008-01-01

    Given the increasing prevalence of cryptococcosis caused by Cryptococcus gattii (serotypes B and C) strains, there is a need for rapid and reliable tests that discriminate C. gattii from Cryptococcus neoformans (serotypes A, D, and AD). Seventy-two C. neoformans strains, sixty-seven C. gattii strains, and five Candida albicans strains were analyzed for their ability to grow and produce pigment on minimal D-tryptophan D-proline (m-DTDP) medium, on yeast carbon base D-tryptophan D-proline (YCB-DTDP) medium, and on fructose D-tryptophan glycine (m-FDTG) medium. Of the C. gattii and C. neoformans isolates, 94% and 0% grew on m-DTDP agar, respectively, and 98% and 0% grew in YCB-DTDP medium, respectively. C. gattii produced large amounts of brown intracellular pigment(s) on m-DTDP agar and smaller amounts of yellow-brown (amber) extracellular pigment(s). C. albicans grew on both media and produced a pink photoactivated pigment on m-DTDP agar. C. gattii produced large amounts of brown intracellular pigments on the differential medium m-FDTG, whereas C. neoformans produced smaller amounts of the brown pigments and C. albicans produced a pink pigment. The pigments produced by C. gattii from D-tryptophan were distinct and were not related to melanin formation from 3,4-dihydroxyphenylalanine. Thin-layer chromatography of the methanol-extracted C. gattii cells detected four different pigments, including brown (two types), yellow, and pink-purple compounds. We conclude that tryptophan-derived pigments are not melanins and that growth on m-DTDP or YCB-DTDP agar can be used to rapidly differentiate C. gattii from C. neoformans. PMID:17989195

  17. Dietary supplements in sport.

    PubMed

    Burke, L M; Read, R S

    1993-01-01

    Studies of the dietary practices of athletes report that nutritional supplements are commonly used. Supplementation practices vary between sports and individual athletes; however, there is evidence that at least some athletes use a large number of supplements concurrently, often in doses that are very high in comparison with normal dietary intakes. In exploring supplementation practices we propose a classification system separating the supplements into dietary supplements and nutritional erogogenic aids. The dietary supplement is characterised as a product which can be used to address physiological or nutritional issues arising in sport. It may provide a convenient or practical means of consuming special nutrient requirements for exercise, or it may be used to prevent/reverse nutritional deficiencies that commonly occur among athletes. The basis of the dietary supplement is an understanding of nutritional requirements and physiological effects of exercise. When the supplement is used to successfully meet a physiological/nutritional goal arising in sport it may be demonstrated to improve sports performance. While there is some interest in refining the composition or formulation of some dietary supplements, the real interest belongs to the use or application of the supplement; i.e. educating athletes to understand and achieve their nutritional needs in a specific sports situation. The sports drink (carbohydrate-electrolyte replacement drink) is a well known example of a dietary supplement. Scientific attitudes towards the sports drink have changed over the past 20 years. Initial caution that carbohydrate-electrolyte fluids compromise gastric emptying during exercise has now been shown to be unjustified. Numerous studies have shown that 5 to 10% solutions of glucose, glucose polymers (maltodextrins) and other simple sugars all have suitable gastric emptying characteristics for the delivery of fluid and moderate amounts of carbohydrate substrate. The optimal

  18. Hypermedia as medium

    NASA Technical Reports Server (NTRS)

    Dede, Christopher J.

    1990-01-01

    Claims and rebuttals that hypermedia (the associative, nonlinear interconnection of multimedia materials) is a fundamentally innovative means of thinking and communicating are described. This representational architecture has many advantages that make it a major advance over other media; however, it also has several intrinsic problems that severly limits its effectiveness as a medium. These advantages and limits in applications are discussed.

  19. Holographic recording medium

    NASA Technical Reports Server (NTRS)

    Gange, Robert Allen (Inventor)

    1977-01-01

    A holographic recording medium comprising a conductive substrate, a photoconductive layer and an electrically alterable layer of a linear, low molecular weight hydrocarbon polymer has improved fatigue resistance. An acrylic barrier layer can be interposed between the photoconductive and electrically alterable layers.

  20. Evaluation of three commercial agar preparations for the presumptive identification of significant urinary isolates.

    PubMed

    Miles, K I; Wren, M W D

    2005-01-01

    Three commercially available pre-poured chromogenic preparations--chromogenic urinary tract infection (UTI) medium (chromogenic UTI, Oxoid), CHROMagar Orientation (Becton Dickinson) and CPS ID2 (bioMérieux)--are evaluated in comparison to routine urine microbiology using cysteine lactose electrolyte-deficient (CLED) medium and conventional methods of identification and susceptibility testing by Vitek 1 for the majority of isolates. Most isolates were Escherichia coli, and a chromogenic medium has been shown to be a reliable, rapid and more economic medium on which to presumptively identify these organisms due to the substrates the strain utilises in the plate and the chromogen subsequently produced. However, the opacity of chromogenic UTI made the medium difficult to inoculate and read, although the colours were clear and strong. Although there was no statistical difference between CHROMagar Orientation and CPS ID2, the colours observed on the former were stronger. This meant that colony counting was possible at significant concentrations of 10(4) and 10(5) colony-forming units (cfu)/mL and it may be easier to detect mixtures that would indicate contamination. Chromogenic media are richer than CLED and a number of Lactobacillus spp. (normally regarded as normal flora) grew on this medium. These were not considered to be significant.