Biopelículas de Staphylococcus spp. sobre acero inoxidable utilizando leche y brain heart infusion broth como medios de cultivo

Staphylococcus spp. tiene la capacidad de adherirse y desarrollar biopelículas sobre diferentes superficies de contacto. Así el objetivo de la presente investigación fue comparar la producción de biopelículas de Staphylococcus spp. sobre acero inoxidable empleando dos medios de cultivo, leche Ultra High Temperatura (UHT) y Brain Heart Infusion broth (BHI). Se realizaron recuentos microbiológicos de las células adheridas en dos tiempos (12 y 24 h), en los dos medios de cultivo, incubados a 25 °C. Los recuentos de las células adheridas fueron analizados mediante ANOVA y comparación de medias por el test de Duncan (p < 0,05). Las biopelículas de dos cepas (cepa silvestre y cepa de tipo) cultivadas por 12 h en BHI, fueron observadas empleando microscopia electrónica de barrido (MEB). Se obtuvieron recuentos microbiológicos entre 7 y 8 log UFC/cm2. Fue observada diferencia significativa entre las cepas evaluadas, mientras que, no hubo diferencia significativa en los tiempos y medios de cultivo evaluados. Fue comprobado a través de la MEB que la cepa silvestre S.a2 presentó considerable producción de biopelículas, como era esperado de acuerdo con los resultados encontrados en los recuentos microbiológicos. Esto indicaría que la leche proporciona condiciones adecuadas para la formación de biopelículas de Staphylococcus spp. sobre acero inoxidable

Biopelículas de Staphylococcus spp. sobre acero inoxidable utilizando leche y brain heart infusion broth como medios de cultivo

Staphylococcus spp. tiene la capacidad de adherirse y desarrollar biopelículas sobre diferentes superficies de contacto. Así el objetivo de la presente investigación fue comparar la producción de biopelículas de Staphylococcus spp. sobre acero inoxidable empleando dos medios de cultivo, leche Ultra High Temperatura (UHT) y Brain Heart Infusion broth (BHI). Se realizaron recuentos microbiológicos de las células adheridas en dos tiempos (12 y 24 h), en los dos medios de cultivo, incubados a 25 °C. Los recuentos de las células adheridas fueron analizados mediante ANOVA y comparación de medias por el test de Duncan (p < 0,05). Las biopelículas de dos cepas (cepa silvestre y cepa de tipo) cultivadas por 12 h en BHI, fueron observadas empleando microscopia electrónica de barrido (MEB). Se obtuvieron recuentos microbiológicos entre 7 y 8 log UFC/cm2. Fue observada diferencia significativa entre las cepas evaluadas, mientras que, no hubo diferencia significativa en los tiempos y medios de cultivo evaluados. Fue comprobado a través de la MEB que la cepa silvestre S.a2 presentó considerable producción de biopelículas, como era esperado de acuerdo con los resultados encontrados en los recuentos microbiológicos. Esto indicaría que la leche proporciona condiciones adecuadas para la formación de biopelículas de Staphylococcus spp. sobre acero inoxidable

Bioactive Andean sweet potato starch-based foam incorporated with oregano or thyme essential oil

In this research, sweet potato starch and oregano (OEO) or thyme (TEO) essential oil at two concentrations (7.5 and 10 %) were used to produce bioactive foams by thermopressing. The foams were characterized according to microstructure, mechanical properties, antimicrobial properties, and structural properties by X-ray diffraction, scanning electron microscopy, and Fourier-transform-infrared spectroscopy (FT-IR). In all cases, essential oil addition affected the foam color, yielding reddish/yellowish foams, but not the foam thickness. FT-IR spectrum and X-ray diffraction revealed starch-lipid interactions. According to the micrographs, the lipids were localized in the first layer. Thus, formation of amylose-essential oil complexes in the foam may have prevented the essential oil from degrading under the thermoforming temperature. Essential oil addition yielded starch foams with low water solubility and mechanical resistance, especially for 10 % OEO. Meanwhile, these foams were more effective against Salmonella (Gram-negative bacteria) and L. monocytogenes (Gram-positive bacteria). The antimicrobial activity of the foams containing essential oil makes them beneficial for application as bioactive materials. Therefore, bioactive sweet potato starch-based foams can be prepared by thermopressing and be applied as food container23CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP132428/2018-02018/02500-

Cyproterone Acetate Quantification In Human Plasma By High-performance Liquid Chromatography Coupled To Atmospheric Pressure Photoionization Tandem Mass Spectrometry

A specific, fast and sensitive high performance liquid chromatography (HPLC) coupled to atmospheric pressure photoionization (APPI) tandem mass spectrometric (LC-MS/MS) assay was developed for the determination of cyproterone (CYP) acetate (CAS 427-51-0) in human plasma. The retention times were 3.26 and 2.90 min for CYP acetate and its internal standard (I. S.) finasteride (FIN), respectively. The overall mean recovery, using liquid/liquid extraction, was found to be 109.0, 107.7 and 100.3%, for low, mediumand high concentrations, respectively. Calibration curves were linear in the concentration range of 0.1 - 50.0 ng/ml, and the lower limit of quantification (LLOQ) was 0.1 ng/ml. The LLOQ, 0.1 ng/ml, was sensitive enough for detecting terminal phase concentrations of the drug. Inter-batch precision of the method ranged from 2.2 to 5.55%, while Inter-batch accuracy ranged from 95.5 to 100.0%. Intra-batch precision ranged from 1.8 to 5.6%, while Intra-batch accuracy ranged from 92.0 to 99.4% at concentrations of 0.3 ng/ml, 20.0 and 40.0 ng/ml. The developed method was applied to a bioequivalenc study of CYP acetate in a group of 44 female volunteers at a single oral dose of a 2 mg tablet, in a combination of ethinylestradiol/CYP acetate (0.25/2 mg). The plasma concentration of CYP acetate did not differ significantly after administration of both formulations (test formulation and the reference one). The geometric mean and respective 90% CI of CYP acetate test/reference percent ratios were 90.66 % (84.39-97.40%) for Cmax and 96.20 % (90.45-102.33 %) for AUC0-t. © ECV Editio Cantor Verlag.597335344Baumann, A., Kulmann, H., Gorkov, V., Mahler, M., Kuhnz, W., Radioimmunological analysis of cyproterone acetate in human serum. Comparison with a gas chromatographic/ mass spectrometric method and influence of each method on the outcome of a bioequivalence trial (1996) Arzneimittelforschung, 46, pp. 412-418Speck, U., Wendt, H., Schulze, P.E., Jentsch, D., Bio-availability and pharmacokinetics of cyproterone acetate-14C and ethinyloestradiol-3H after oral administration as a coated tablet (SH B 209 AB) (1976) Contraception, 14, pp. 151-163Dusterberg, B., Plasma levels of levonorgestrel, gestodene, norethisterone and cyproterone acetate on single-dose subcutaneous administration in oily solution in the rat, beagle and rhesus monkey (1984) Steroids, 43 (1), pp. 43-56. , DOI 10.1016/0039-128X(84)90057-6Fiet, J., Giton, F., Boudi, A., Boudou, P., Vexiau, P., Galons, H., Raynaud, J.-P., Highly sensitive and specific time-resolved fluoroimmunoassay (TR-FIA) of cyproterone acetate and free cyproterone (2000) Journal of Steroid Biochemistry and Molecular Biology, 75 (4-5), pp. 315-322. , DOI 10.1016/S0960-0760(00)00189-8, PII S0960076000001898Kuhnz, W., Kulmann, H., Fuhrmeister, A., Investigation into the age-dependence of the pharmacokinetics of cyproterone acetate in healthy male volunteers (1997) European Journal of Clinical Pharmacology, 53 (1), pp. 75-80. , DOI 10.1007/s002280050340Nieuweboer, B., Lubke, K., Radioimmunological determination of cyproterone acetate (1977) HormRes, 8, pp. 210-218Bebawy, L.I., Mostafa, A.A., Refaat, H.H., Different methods for the determination of gestodene, and cyproterone acetate in raw material and dosage forms (2001) J Pharm Biomed Anal, 25, pp. 425-436Cannell, G.R., Mortimer, R.H., Thomas, M.J., High-performance liquid chromatographic estimation of cyproterone acetate in human plasma (1981) J Chromatogr, 226, pp. 492-497Christiaens, B., Fillet, M., Chiap, P., Rbeida, O., Ceccato, A., Streel, B., Graeve, J.D., Hubert, P., Fully automated method for the liquid chromatographic-tandem mass spectrometric determination of cyproterone acetate in human plasma using restricted access material for on-line sample clean-up (2004) Journal of Chromatography a, 1056 (1-2 SPEC.ISS), pp. 105-110. , DOI 10.1016/j.chroma.2004.06.107, PII S0021967304010787Dikkeschei, L.D., Wolthers, B.G., De Ruyter-Buitenhuis, A.W., Nagel, G.T., Sleijfer, D.T., Willemse, P.H., Determination of megestrol acetate and cyproterone acetate in serum of patients with advanced breast cancer by high-performance liquid chromatography (1990) J Chromatogr, 529, pp. 145-154Frith, R.G., Phillipou, G., 15-Hydroxycyproterone acetate and cyproterone acetate levels in plasma and urine (1985) Journal of Chromatography - Biomedical Applications, 338 (1), pp. 179-186Yodo, K., Saisho, S., Shimozawa, K., Yata, J., A reversed-phase high-performance liquid chromatographic method for the simultaneous determination of serum concentrations of cyproterone acetate and 15 beta-hydroxycyproterone acetate (1988) Endocrinologia Japonica, 35 (1), pp. 143-148Matejicek, D., Kuban, V., High performance liquid chromatography/ion-trap mass spectrometry for separation and simultaneous determination of ethynylestradiol, gestodene, levonorgestrel, cyproterone acetate and desogestrel (2007) Analytica Chimica Acta, 588 (2), pp. 304-315. , DOI 10.1016/j.aca.2007.02.028, PII S0003267007003273Viswanathan, C.T., Bansal, S., Booth, B., Destefano, A.J., Rose, M.J., Sailstad, J., Shah, V.P., Weiner, R., Quantitative bioanalytical methods validation and implementation: Best practices for chromatographic and ligand binding assays (2007) Pharmaceutical Research, 24 (10), pp. 1962-1973. , DOI 10.1007/s11095-007-9291-7Pereira, A.S., Mendes, G.D., Oliveira, L.S., Valle, H.F., De Nucci, G., Atmospheric pressure photoionization applied to quantitation of cyproterone acetate in human plasma (2005) J Chromatogr Sci, 43, pp. 513-517Robb, D.B., Covey, T.R., Bruins, A.P., Atmospheric pressure photoionization: An ionization method for liquid chromatography - Mass spectrometry (2000) Analytical Chemistry, 72 (15), pp. 3653-3659. , DOI 10.1021/ac0001636Leinonen, A., Kuuranne, T., Kostiainen, R., Liquid chromatography/mass spectrometry in anabolic steroid analysis - Optimization and comparison of three ionization techniques: Electrospray ionization, atmospheric pressure chemical ionization and atmospheric pressure photoionization (2002) Journal of Mass Spectrometry, 37 (7), pp. 693-698. , DOI 10.1002/jms.328Cai, Y., Kingery, D., McConnell, O., Bach II, A.C., Advantages of atmospheric pressure photoionization mass spectrometry in support of drug discovery (2005) Rapid Commun Mass Spectrom, 19, pp. 1717-172