87 research outputs found

    Chemical resistance of the gram-negative bacteria to different sanitizers in a water purification system

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    BACKGROUND: Purified water for pharmaceutical purposes must be free of microbial contamination and pyrogens. Even with the additional sanitary and disinfecting treatments applied to the system (sequential operational stages), Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were isolated and identified from a thirteen-stage purification system. To evaluate the efficacy of the chemical agents used in the disinfecting process along with those used to adjust chemical characteristics of the system, over the identified bacteria, the kinetic parameter of killing time (D-value) necessary to inactivate 90% of the initial bioburden (decimal reduction time) was experimentally determined. METHODS: Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were called in house (wild) bacteria. Pseudomonas diminuta ATCC 11568, Pseudomonas alcaligenes INCQS , Pseudomonas aeruginosa ATCC 15442, Pseudomonas fluorescens ATCC 3178, Pseudomonas picketti ATCC 5031, Bacillus subtilis ATCC 937 and Escherichia coli ATCC 25922 were used as 'standard' bacteria to evaluate resistance at 25°C against either 0.5% citric acid, 0.5% hydrochloric acid, 70% ethanol, 0.5% sodium bisulfite, 0.4% sodium hydroxide, 0.5% sodium hypochlorite, or a mixture of 2.2% hydrogen peroxide (H(2)O(2)) and 0.45% peracetic acid. RESULTS: The efficacy of the sanitizers varied with concentration and contact time to reduce decimal logarithmic (log(10)) population (n cycles). To kill 90% of the initial population (or one log(10 )cycle), the necessary time (D-value) was for P. aeruginosa into: (i) 0.5% citric acid, D = 3.8 min; (ii) 0.5% hydrochloric acid, D = 6.9 min; (iii) 70% ethanol, D = 9.7 min; (iv) 0.5% sodium bisulfite, D = 5.3 min; (v) 0.4% sodium hydroxide, D = 14.2 min; (vi) 0.5% sodium hypochlorite, D = 7.9 min; (vii) mixture of hydrogen peroxide (2.2%) plus peracetic acid (0.45%), D = 5.5 min. CONCLUSION: The contact time of 180 min of the system with the mixture of H(2)O(2)+ peracetic acid, a total theoretical reduction of 6 log(10 )cycles was attained in the water purified storage tank and distribution loop. The contact time between the water purification system (WPS) and the sanitary agents should be reviewed to reach sufficient bioburden reduction (over 6 log(10))

    Isolation, Characterization and Quantity Determination of Aristolochic Acids, Toxic Compounds in Aristolochia bracteolata L.

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    Background Aristolochic Acids (AAs) are major components of plants in Aristolochia and have been found to be nephrotoxic, carcinogenic and mutagenic. Herein reported are the isolation, identification and quantity determination methods of Aristolochic Acid-I (AA-I) and Aristolochic Acid-II (AA-II) toxic compounds of Aristolochia bracteolata indigenous to Central Sudan and medicinally used in diverse biological functions including analgesic and diuretic effects, treatment of tumors, malaria and/or fevers. Methods and results AAs mixture was extracted with methanol from the defatted material of Aristolochia bracteolata whole plant at room temperature and was isolated from the aqueous methanol extract by chloroform. Moreover, Silica-gel column chromatography and Preparative Thin Layer Chromatography (PTLC) using chloroform/methanol gradient mixtures were used to isolate AAs mixtures as a yellow crystalline solid. A preliminary detection of AAs was made by Thin Layer Chromatography (silica-gel, chloroform: methanol (6:1)). The Rf value of the acids mixture was 0.43-0.46. The presence of AAs in plant sample was confirmed by High Performance Liquid Chromatography/Ultraviolet (HPLC/UV) analysis using 1% acetic acid and methanol (40:60) as mobile phase and maximum absorption wave length of 250 nm. Quantitative determination of AA-II (49.03 g/kg) and AA-I (12.98 g/kg) was also achieved by HPLC/UV. Recommendation It is recommended that the use of Aristolochia bracteolata as a medicinal plant should be extremely limited or strictly prohibited. The chromatograms obtained in this study can serve as fingerprints to identify AAs in plant samples

    Extractive Spectrophotometric Method for the Determination of Tropicamide

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    Two simple, rapid, and extractive spectrophotometric methods were developed for the determination of tropicamide (TPC). These methods are based on the formation of ionpair complexes between the basic nitrogen of the drug with bromocresol purple (BCP) and methyl orange (MO) in acidic buffer solution. The formed complexes were extracted with chloroform and measured at 408 and 427 nm using BCP and MO, respectively. Beer's law was obeyed in the range 1.0–16 μg ml–1 with correlation coefficient (n=6) ≥0.9991. The molar absorpitivity, Sandell sensitivity, detection, and quantification limits were also calculated. The composition of the ion pairs was found 1:1 by Job's method. The proposed methods have been applied successfully for the analysis of TPC in pure and in its eye drops

    Scientific Opinion on the safety and efficacy of vitamin D<sub>3</sub> (cholecalciferol) as a feed additive for all animal species or categories based on a dossier submitted by Lohmann Animal Health GmbH

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    The principal physiological role of vitamin D in all vertebrates is in calcium and phosphorus homeostasis. The classic clinical deficiency syndrome is rickets. The FEEDAP Panel notes that for turkeys for fattening, equines, bovines, ovines and pigs the maximum authorised content of vitamin D3 in feed does not provide any margin of safety, and that, except for pigs and fish, the maximum content is above the upper safe level, according to National Research Council data when animals were fed a supplemented diet for more than 60 days. The FEEDAP Panel is not in a position to draw final conclusions on the safety of vitamin D for target animals but considers the current maximum contents temporarily acceptable pending a review of the recent scientific literature. The two vitamin sources under application are considered safe for the target animals provided the current maximum contents in feed are respected. Any administration of vitamin D3 via water for drinking could exceed the safe amounts of vitamin D and therefore represents a safety concern. Current nutritional surveys in 14 European countries showed that vitamin D intake is below the upper safe limit. The FEEDAP Panel assumes that foodstuffs of animal origin were produced following current production practices, including vitamin D3 supplementation of feed, and concludes that the use of vitamin D in animal nutrition at the currently authorised maximum dietary content has not and will not cause the tolerable upper intake level to be exceeded. Vitamin D3 should be considered as irritant to skin and eyes, and as a dermal sensitiser. Inhaled vitamin D3 is highly toxic; exposure to dust is harmful. No environmental risk resulting from the use of vitamin D3 in animal nutrition is expected. The vitamin D3 under application is regarded as an effective dietary source of the vitamin in animal nutrition

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