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Sample records for tetracycline actions relevant

  1. Reaction of tetracycline with biologically relevant chloramines

    Science.gov (United States)

    Benavides, J.; Barrias, P.; Piro, N.; Arenas, A.; Orrego, A.; Pino, E.; Villegas, L.; Dorta, E.; Aspée, A.; López-Alarcón, C.

    2017-05-01

    Helicobacter pylori (H. pylori) infection triggers inflammatory processes with the consequent production of hypochlorous acid (HOCl), monochloramine (NH2Cl), and protein-derived chloramines. As the therapy for eradicating H. pylori is partially based on the use of tetracycline, we studied the kinetic of its consumption elicited by HOCl, NH2Cl, N-chloro-n-butylamine (NHCl-But, used as a lysine-derived chloramine model), and lysozyme-derived chloramines. In the micromolar concentration range, tetracycline reacted rapidly with HOCl, generating in the first few seconds intermediates of short half-life. In contrast, a slow tetracycline consumption was observed in the presence of high NH2Cl and NHCl-But concentrations (millimolar range). Similar chlorinated products of tetracycline were identified by mass spectrometry, in the presence of HOCl and NH2Cl. These results evidenced that tautomers of tetracycline are pivotal intermediates in all reactions. In spite of the low reactivity of chloramines towards tetracycline, it is evident that, in the concentration range where they are produced in a H. pylori infection (millimolar range), the reactions lead to oxidation and/or chlorination of tetracycline. This kind of reactions, which were also observed triggered by lysozyme-derived chloramines, could limit the efficiency of the tetracycline-based therapy.

  2. Toxicity of tetracyclines and tetracycline degradation products to environmentally relevant bacteria, including selected tetracycline-resistant bacteria

    DEFF Research Database (Denmark)

    Halling-Sørensen, B.; Sengeløv, G.; Tjørnelund, J.

    2002-01-01

    solution were theoretically identified at various environmental conditions, such as pH, presence of chelating, metals, and fight. Their potency was assessed on sludge bacteria, tetracycline-sensitive soil bacteria, and tetracycline-resistant strains. Several of the degradation products had potency...

  3. Anti-inflammatory Actions of Adjunctive Tetracyclines and Other Agents in Periodontitis and Associated Comorbidities

    Science.gov (United States)

    Tilakaratne, Aruni; Soory, Mena

    2014-01-01

    The non-antimicrobial properties of tetracyclines such as anti-inflammatory, proanabolic and anti-catabolic actions make them effective pharmaceuticals for the adjunctive management of chronic inflammatory diseases. An over-exuberant inflammatory response to an antigenic trigger in periodontitis and other chronic inflammatory diseases could contribute to an autoimmune element in disease progression. Their adjunctive use in managing periodontitis could have beneficial effects in curbing excessive inflammatory loading from commonly associated comorbidities such as CHD, DM and arthritis. Actions of tetracyclines and their derivatives include interactions with MMPs, tissue inhibitors of MMPs, growth factors and cytokines. They affect the sequence of inflammation with implications on immunomodulation, cell proliferation and angiogenesis; these actions enhance their scope, in treating a range of disease entities. Non-antimicrobial chemically modified tetracyclines (CMTs) sustain their diverse actions in organ systems which include anti-inflammatory, anti-apoptotic, anti-proteolytic actions, inhibition of angiogenesis and tumor metastasis. A spectrum of biological actions in dermatitis, periodontitis, atherosclerosis, diabetes, arthritis, inflammatory bowel disease, malignancy and prevention of bone resorption is particularly relevant to minocycline. Experimental models of ischemia indicate their specific beneficial effects. Parallel molecules with similar functions, improved Zn binding and solubility have been developed for reducing excessive MMP activity. Curbing excessive MMP activity is particularly relevant to periodontitis, and comorbidities addressed here, where specificity is paramount. Unique actions of tetracyclines in a milieu of excessive inflammatory stimuli make them effective therapeutic adjuncts in the management of chronic inflammatory disorders. These beneficial actions of tetracyclines are relevant to the adjunctive management of periodontitis subjects

  4. Isolation, structural elucidation and in vitro activity of 2-acetyl-2-decarboxamido-oxytetracycline against environmental relevant bacteria, including tetracycline-resistant bacteria

    DEFF Research Database (Denmark)

    Lykkeberg, Anne Kruse; Sengeløv, Gitte; Cornett, Claus

    2004-01-01

    i.d., 5 microm), and the mobile phase contained methanol-water (27:73 (v/v)) with 0.08 M formic acid added. The flow rate was 9.0 ml/min. It was possible to isolate few milligram ADOTC in a day. The compound was unambiguously identified using NMR and MS-MS. The anti-microbial activity against...... activated sludge bacteria was determined giving a potency of only 3% of that of OTC. With tetracycline-resistant bacteria, no anti-microbial activity was observed, indicating a mode of action similar to that of OTC....

  5. Isolation, structural elucidation and in vitro activity of 2-acetyl-2-decarboxamido-oxytetracycline against environmental relevant bacteria, including tetracycline-resistant bacteria

    DEFF Research Database (Denmark)

    Lykkeberg, Anne Kruse; Sengeløv, Gitte; Cornett, Claus

    2004-01-01

    2-Acetyl-2-decarboxamido-oxytetracycline (ADOTC) is a major impurity of oxytetracycline (OTC) produced as a side product during fermentation. ADOTC was isolated from OTC and other impurities using preparative HPLC. The preparative column was an Xterra MS. C-18 chromatographic column (100 mm x 19...... turn W., 5 mum), and the mobile phase contained methanol-water (27:73 (v/v)) with 0.08 M formic acid added. The flow rate was 9.0 ml/min. It was possible to isolate few milligram ADOTC in a day. The compound was unambiguously identified using NMR and MS-MS. The anti-microbial activity against activated...... sludge bacteria was deter-mined giving a potency of only 3% of that of OTC. With tetracycline-resistant bacteria, no anti-microbial activity was observed, indicating a mode of action similar to that of OTC....

  6. Identifying relevant feature-action associations for grasping unmodelled objects

    DEFF Research Database (Denmark)

    Thomsen, Mikkel Tang; Kraft, Dirk; Krüger, Norbert

    2015-01-01

    content. The method is provided with a large and structured set of visual features, motivated by the visual hierarchy in primates and finds relevant feature action associations automatically. We apply our method in a simulated environment on three different object sets for the case of grasp affordance...

  7. Relevance Theory, Action Theory and Second Language Communication Strategies

    Science.gov (United States)

    Foster-Cohen, Susan H.

    2004-01-01

    The discussion in this article offers a comparison between Relevance Theory as an account of human communication and Herbert Clark's (1996) sociocognitive Action Theory approach. It is argued that the differences are fundamental and impact analysis of all kinds of naturally occurring communicative data, including that produced by non-native…

  8. [Tetracyclines, sulfonamides and metronidazole].

    Science.gov (United States)

    Pérez-Trallero, Emilio; Iglesias, Luis

    2003-11-01

    Tetracyclines form a group of natural and semisynthetic products that acts inhibiting the bacterial protein synthesis. They are bacteriostatic agents, exhibiting activity against a wide range of organisms, but they are at the present of limited use because of their acquired resistance. Doxycycline is currently the most frequently used tetracycline in human medicine and it is included in the List of Essential Medicines of the World Health Organization. Sulfonamides are synthetic, broad-spectrum bacteriostatic antibiotics. They were the first effective systemic antimicrobial agents. Their mode of action is based on the inhibition of DNA synthesis. Due to their toxicity and high adquired resistance their use is currently very low. Metronidazole is the main compound of 5-nitroimidazole family. It is a very active bactericidal antibiotic against anaerobic and some microaerophilic bacteria and it is still very useful in the treatment of bacterian and parasitic infections.

  9. Bismuth, Metronidazole, and Tetracycline

    Science.gov (United States)

    Helidac® (as a kit containing Bismuth Subsalicylate, Metronidazole, Tetracycline) ... Bismuth, metronidazole, and tetracycline is used along with other ulcer medications to treat duodenal ulcers. It is ...

  10. The Confucian View of the Relationship between Knowledge and Action and Its Relevance to Action Research

    Science.gov (United States)

    Tsai, Ching-tien

    2014-01-01

    There are marked similarities between Confucian ideas about the relationship between action, knowledge and learning, and contemporary educational thinking about action research. Examples can be seen in the relationship between action and research. First, Confucius emphasized the importance of "action" which was different from…

  11. Sustainable seafood consumption in action: Relevant behaviours and their predictors

    DEFF Research Database (Denmark)

    Richter, Isabel; Thøgersen, John; Klöckner, Christian A.

    2017-01-01

    The current dominance of unsustainable seafood consumption threatens future food security. To preserve marine food resources over the long term more sustainable ways to consume seafood have to be promoted. This paper discusses consumer actions that represent the sustainable consumption of seafood...... in Norway. The predictive power of intention, social norms, trust and general pro-environmental attitudes are theoretically discussed and statistically tested in regards to (a) using sustainable seafood labels, and (b) using sustainable seafood guides. Data analysis (N=1190 Norwegian adults) shows that both...... behaviors are related to social norms, intentions and trust. This pattern also turns out to be stable over time as a second data collection on the same sample four weeks later shows. Causal relationships have been identified by applying a cross-lagged panel analysis between intentions and sustainable...

  12. Sustainable Seafood Consumption in Action: Relevant Behaviors and their Predictors

    Directory of Open Access Journals (Sweden)

    Isabel Richter

    2017-12-01

    Full Text Available Within the discussion around sustainable diets, seafood consumption is still a relatively neglected field. This article discusses relevant behaviours consumers can perform to consume seafood sustainably. The predictive power of intention, descriptive social norms, trust, awareness and pro-environmental attitudes are theoretically discussed and statistically tested across two studies in regards to (a using sustainable seafood labels, and (b using sustainable seafood guides. Data analysis (N1 = 309, N2 = 881 Norwegian adults shows that intentions, social norms and trust predict seafood label use across studies. The variables predicting seafood guide use are less stable which might be due to this behaviour being performed by a very small fraction of consumers only. Causal relationships have been identified in study 2 by applying cross-lagged panel analyses between intentions, trust and social norms and seafood label use. Further causal relationships were found between intentions, trust and awareness and seafood guide use. A bidirectional relationship was confirmed between descriptive social norms and seafood guide use. Potential strategies to promote seafood label- and seafood guide use, are discussed based on these results.

  13. Radiation deamination of tetracycline

    International Nuclear Information System (INIS)

    Kuduk-Jaworska, J.

    1980-01-01

    The fundamental product of tetracycline hydrochlorine gamma radiolysis was separated in its solid state. From the results of spectroscopic studies it has been established that it is des-N,N-dimethylaminotetracycline. (author)

  14. Tetracycline Antibiotics and Resistance.

    Science.gov (United States)

    Grossman, Trudy H

    2016-04-01

    Tetracyclines possess many properties considered ideal for antibiotic drugs, including activity against Gram-positive and -negative pathogens, proven clinical safety, acceptable tolerability, and the availability of intravenous (IV) and oral formulations for most members of the class. As with all antibiotic classes, the antimicrobial activities of tetracyclines are subject to both class-specific and intrinsic antibiotic-resistance mechanisms. Since the discovery of the first tetracyclines more than 60 years ago, ongoing optimization of the core scaffold has produced tetracyclines in clinical use and development that are capable of thwarting many of these resistance mechanisms. New chemistry approaches have enabled the creation of synthetic derivatives with improved in vitro potency and in vivo efficacy, ensuring that the full potential of the class can be explored for use against current and emerging multidrug-resistant (MDR) pathogens, including carbapenem-resistant Enterobacteriaceae, MDR Acinetobacter species, and Pseudomonas aeruginosa. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.

  15. Comparison of metals and tetracycline as selective agents for development of tetracycline resistant bacterial communities in agricultural soil

    DEFF Research Database (Denmark)

    Song, Jianxiao; Rensing, Christopher; Holm, Peter Engelund

    2017-01-01

    Environmental selection of antibiotic resistance may be caused by either antibiotic residues or coselecting agents. Using a strictly controlled experimental design, we compared the ability of metals (Cu or Zn) and tetracycline to (co)select for tetracycline resistance in bacterial communities. Soil...... microcosms were established by amending agricultural soil with known levels of Cu, Zn, or tetracycline known to represent commonly used metals and antibiotics for pig farming. Soil bacterial growth dynamics and bacterial community-level tetracycline resistance were determined using the [(3)H......]leucine incorporation technique, whereas soil Cu, Zn, and tetracycline exposure were quantified by a panel of whole-cell bacterial bioreporters. Tetracycline resistance increased significantly in soils containing environmentally relevant levels of Cu (≥365 mg kg(-1)) and Zn (≥264 mg kg(-1)) but not in soil spiked...

  16. Triclosan Decreases Rat Thyroxine: Mode-of-Action, Developmental Susceptibility and Human Relevance

    Science.gov (United States)

    Triclosan (TCS) decreases serum thyroxine (T4) in the rat. In vivo and in vitro approaches were used to address three uncertainties: by what mode-of-action (MOA) does TCS decrease T4; does TCS decrease T4 developmentally; and, are effects observed in rats relevant to humans? To t...

  17. Compendium of ORD and OSWER documents relevant to RCRA corrective action

    International Nuclear Information System (INIS)

    1992-04-01

    Throughout the past decade, several offices within the US Environmental Protection Agency (EPA) have been involved in hazardous waste management technologies research, remedial action at chemically contaminated sites, and regulatory development for permitting hazardous waste management facilities. The primary offices involved in these activities include the Office of Research and Development (ORD) and the Office of Solid Waste and Emergency Response (OSWER). During this period, substantial knowledge and experience have been gained relevant to the a placability of remedial action technologies in various environmental setting

  18. Science youth action research: Promoting critical science literacy through relevance and agency

    Science.gov (United States)

    Coleman, Elizabeth R.

    This three-article dissertation presents complementary perspectives on Science Youth Action Research (Sci-YAR), a K-12 curriculum designed to emphasize relevance and agency to promote youth's science learning. In Sci-YAR, youth conduct action research projects to better understand science-related issues in their lives, schools, or communities, while they simultaneously document, analyze, and reflect upon their own practices as researchers. The first article defines Sci-YAR and argues for its potential to enhance youth's participation as citizens in a democratic society. The second article details findings from a case study of youth engaged in Sci-YAR, describing how the curriculum enabled and constrained youth's identity work in service of critical science agency. The third article provides guidance to science teachers in implementing student-driven curriculum and instruction by emphasizing Sci-YAR's key features as a way to promote student agency and relevance in school science.

  19. Action video game players' visual search advantage extends to biologically relevant stimuli.

    Science.gov (United States)

    Chisholm, Joseph D; Kingstone, Alan

    2015-07-01

    Research investigating the effects of action video game experience on cognition has demonstrated a host of performance improvements on a variety of basic tasks. Given the prevailing evidence that these benefits result from efficient control of attentional processes, there has been growing interest in using action video games as a general tool to enhance everyday attentional control. However, to date, there is little evidence indicating that the benefits of action video game playing scale up to complex settings with socially meaningful stimuli - one of the fundamental components of our natural environment. The present experiment compared action video game player (AVGP) and non-video game player (NVGP) performance on an oculomotor capture task that presented participants with face stimuli. In addition, the expression of a distractor face was manipulated to assess if action video game experience modulated the effect of emotion. Results indicate that AVGPs experience less oculomotor capture than NVGPs; an effect that was not influenced by the emotional content depicted by distractor faces. It is noteworthy that this AVGP advantage emerged despite participants being unaware that the investigation had to do with video game playing, and participants being equivalent in their motivation and treatment of the task as a game. The results align with the notion that action video game experience is associated with superior attentional and oculomotor control, and provides evidence that these benefits can generalize to more complex and biologically relevant stimuli. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. The history of the tetracyclines.

    Science.gov (United States)

    Nelson, Mark L; Levy, Stuart B

    2011-12-01

    The history of the tetracyclines involves the collective contributions of thousands of dedicated researchers, scientists, clinicians, and business executives over the course of more than 60 years. Discovered as natural products from actinomycetes soil bacteria, the tetracyclines were first reported in the scientific literature in 1948. They were noted for their broad spectrum antibacterial activity and were commercialized with clinical success beginning in the late 1940s to the early 1950s. The second-generation semisynthetic analogs and more recent third-generation compounds show the continued evolution of the tetracycline scaffold toward derivatives with increased potency as well as efficacy against tetracycline-resistant bacteria, with improved pharmacokinetic and chemical properties. Their biologic activity against a wide spectrum of microbial pathogens and their uses in mammalian models of inflammation, neurodegeneration, and other biological systems indicate that the tetracyclines will continue to be successful therapeutics in infectious diseases and as potential therapeutics against inflammation-based mammalian cell diseases. © 2011 New York Academy of Sciences.

  1. An investigation into the relevance of action planning, theory of planned behaviour concepts, and automaticity for fruit intake action control.

    Science.gov (United States)

    de Bruijn, Gert-Jan; Wiedemann, Amelie; Rhodes, Ryan E

    2014-09-01

    In the action control framework, intention-behaviour discordance is studied around public health guidelines. Although this framework has been applied to physical activity behaviours, it has only seen very limited attention regarding fruit intake. The purpose of this study was therefore to investigate distributions and predictors of fruit intake intention-behaviour discordance. Prospective correlational design. Data were obtained from undergraduate students (n = 413) using validated questionnaires. Variables from the theory of planned behaviour, automaticity, and action planning were assessed at baseline, and fruit intake was assessed 2 weeks later. Data were analysed using discriminant function analyses and analyses of variance. The proportion of unsuccessful intenders ranged from 39.2% to 80.8%. There was a larger proportion of fruit intake intenders amongst those who reported strong automatic fruit intake. Action control was predicted by fruit intake automaticity and affective attitudes, but the strongest predictor was perceived behavioural control. No action planning items were related to fruit intake action control. There is considerable asymmetry in the intention-fruit intake relationship. An application of the action control framework may stimulate debate on the applicability of intention-based models at the public health level. What is already known on this subject? Intention is theorized to be a key construct in fruit intake. Studies in the physical activity domain indicate that nearly half of the people with positive intentions fail to subsequently act. What does this study add? The proportion of unsuccessful intenders ranged from 39.2% to 80.8%. Holding positive intentions is not sufficient to consume fruit at suggested public health guidelines. Perceived behavioural control is the most important predictor of fruit intake action control. © 2013 The British Psychological Society.

  2. EFFECT OF TETRACYCLINES ON THE INTRACELLULAR AMINO ACIDS OF MOLDS.

    Science.gov (United States)

    FREEMAN, B A; CIRCO, R

    1963-07-01

    Freeman, Bob A. (University of Chicago, Chicago, Ill.) and Richard Circo. Effect of tetracyclines on the intracellular amino acids of molds. J. Bacteriol. 86:38-44. 1963.-The tetracycline antibiotics were shown to alter the amino acid metabolism of molds whose growth is not markedly affected. Eight molds were grown in the presence of these antiobiotics; four exhibited a general reduction in the concentration of the intracellular amino acids, except for glutamic acid and alanine. In most of these four cultures, the tetracyclines also caused the complete disappearance of arginine, lysine, proline, phenylalanine, and tyrosine from the intracellular amino acid pool. The significance of these observations and the usefulness of the method in the study of the mechanisms of antibiotic action are discussed.

  3. An investigation into the relevance of action planning, theory of planned behaviour concepts, and automaticity for fruit intake action control

    NARCIS (Netherlands)

    de Bruijn, G.J.; Wiedemann, A.; Rhodes, R.E.

    2014-01-01

    Objectives In the action control framework, intention-behaviour discordance is studied around public health guidelines. Although this framework has been applied to physical activity behaviours, it has only seen very limited attention regarding fruit intake. The purpose of this study was therefore to

  4. Size estimates of action-relevant objects remain invariant in the face of systematic changes to postural stability and arousal

    NARCIS (Netherlands)

    Canal Bruland, R.; Aertssen, A.M.; Ham, La.; Stins, J.F.

    2015-01-01

    Perceptual estimates of action-relevant space have been reported to vary dependent on postural stability and concomitant changes in arousal. These findings contribute to current theories proposing that perception may be embodied. However, systematic manipulations to postural stability have not been

  5. Compound list: tetracycline [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available tetracycline TC 00048 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/tetracycline....Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/tetracycline...jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/tetracycline.Rat.in_vivo.Liver.Repeat.zip ... ....Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_viv...o/Liver/Single/tetracycline.Rat.in_vivo.Liver.Single.zip ftp://ftp.biosciencedbc.

  6. "I Will Never Become a Soldier for You!": The Relevance of Biographical Learning for Political Action

    Directory of Open Access Journals (Sweden)

    Andrea Neugebauer

    2011-05-01

    Full Text Available This article focuses on the biographical dimension of the processes of developing political awareness and the significance for consistency in political action. It is based on a single case study which was developed within an oral history project in the 1980s. A new reconstruction of a worker's narrative about his refusal to serve in the army and subsequent flight during the National-Socialist period shows how personal desires for change and institutionalized political patterns of interpretation and action are intertwined. The protagonist could cope with times of extremely restricted latitude for action, as was the case in the Nazi era, acquiring personal learning or crisis management skills as long as there was hope for future emancipation and social integration. In the postwar period the dissipation of this perspective lead to a reduction in his individual ability to take political action. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1102118

  7. Is Insulin Action in the Brain Relevant in Regulating Blood Glucose in Humans?

    Science.gov (United States)

    Dash, Satya; Xiao, Changting; Morgantini, Cecilia; Koulajian, Khajag; Lewis, Gary F

    2015-07-01

    In addition to its direct action on the liver to lower hepatic glucose production, insulin action in the central nervous system (CNS) also lowers hepatic glucose production in rodents after 4 hours. Although CNS insulin action (CNSIA) modulates hepatic glycogen synthesis in dogs, it has no net effect on hepatic glucose output over a 4-hour period. The role of CNSIA in regulating plasma glucose has recently been examined in humans and is the focus of this review. Intransal insulin (INI) administration increases CNS insulin concentration. Hence, INI can address whether CNSIA regulates plasma glucose concentration in humans. We and three other groups have sought to answer this question, with differing conclusions. Here we will review the critical aspects of each study, including its design, which may explain these discordant conclusions. The early glucose-lowering effect of INI is likely due to spillover of insulin into the systemic circulation. In the presence of simultaneous portal and CNS hyperinsulinemia, portal insulin action is dominant. INI administration does lower plasma glucose independent of peripheral insulin concentration (between ∼3 and 6 h after administration), suggesting that CNSIA may play a role in glucose homeostasis in the late postprandial period when its action is likely greatest and portal insulin concentration is at baseline. The potential physiological role and purpose of this pathway are discussed in this review. Because the effects of INI are attenuated in patients with type 2 diabetes and obesity, this is unlikely to be of therapeutic utility.

  8. Electrochemical aptasensor for detecting tetracycline in milk

    International Nuclear Information System (INIS)

    Le, Thi Hanh; Pham, Van Phuc; La, Thi Huyen; Le, Quang Huan; Phan, Thi Binh

    2016-01-01

    A rapid, simple and sensitive biosensor system for tetracycline detection is very important in food safety. In this paper we developed a label-free aptasensor for electrochemical detection of tetracycline. According to the electrochemical impendence spectroscopy (EIS) analysis, there was a linear relationship between the concentration of tetracycline and the electron transfer resistance from 10 to 3000 ng ml −1 of the tetracycline concentration. The detection limit was 10 ng ml −1 in 15 min detection duration. The prepared aptasensor showed a good reproducibility with an acceptable stability in tetracycline detection. The recoveries of tetracycline in spiked milk samples were in the range of 88.1%–94.2%. The aptasensor has sensitivity 98% and specificity of 100%. (paper)

  9. Tetracycline

    Science.gov (United States)

    ... with penicillin to treat certain types of food poisoning, and anthrax (a serious infection that may be ... of the following: anticoagulants ('blood thinners') such as warfarin (Coumadin, Jantoven), and penicillin.be aware that antacids ...

  10. Overview: Using Mode of Action and Life Stage Information to Evaluate the Human Relevance of Animal Toxicity Data

    Energy Technology Data Exchange (ETDEWEB)

    Seed, Jennifer; Carney, E W.; Corley, Rick A.; Crofton, Kevin M.; DeSesso, John M.; Foster, Paul M.; Kavlock, Robert; Kimmel, Gary; Klaunig, James E.; Meek, M E.; Preston, R J.; Slikker, William; Tabacova, Sonia; Williams, Gary M.; Wiltse, J; Zoeller, R T.; Fenner-Crisp, P; Patton, D E.

    2005-10-01

    A complete mode of action human relevance analysis--as distinct from mode of action (MOA) analysis alone--depends on robust information on the animal MOA, as well as systematic comparison of the animal data with corresponding information from humans. In November 2003, the International Life Sciences Institute's Risk Science Institute (ILSI RSI) published a 2-year study using animal and human MOA information to generate a four-part Human Relevance Framework (HRF) for systematic and transparent analysis of MOA data and information. Based mainly on non-DNA-reactive carcinogens, the HRF features a ''concordance'' analysis of MOA information from both animal and human sources, with a focus on determining the appropriate role for each MOA data set in human risk assessment. With MOA information increasingly available for risk assessment purposes, this article illustrates the further applicability of the HRF for reproductive, developmental, neurologic, and renal endpoints, as well as cancer. Based on qualitative and quantitative MOA considerations, the MOA/human relevance analysis also contributes to identifying data needs and issues essential for the dose-response and exposure assessment steps in the overall risk assessment.

  11. Bacterial Resistance to the Tetracyclines and Antimicrobial ...

    African Journals Online (AJOL)

    Optimizing of tetracycline antibiotics dosing and duration in human and animal healthcare and food production might help minimize the emergence of resistance in some situations. New approaches to antimicrobial chemotherapy are needed if we are to survive the increasing rates of tetracycline antibiotic resistance ...

  12. Corneal staining after treatment with topical tetracycline

    NARCIS (Netherlands)

    Lapid-Gortzak, Ruth; Nieuwendaal, Carla P.; Slomovic, Allan R.; Spanjaard, Lodewijk

    2006-01-01

    PURPOSE: The purpose of this paper is to report a case of corneal staining after treatment with topical tetracycline. METHODS: A patient with crystalline keratopathy caused by Streptococcus viridans after corneal transplantation was treated topically with tetracycline eye drops, based on results of

  13. Mode of action associated with development of hemangiosarcoma in mice given pregabalin and assessment of human relevance.

    Science.gov (United States)

    Criswell, Kay A; Cook, Jon C; Wojcinski, Zbigniew; Pegg, David; Herman, James; Wesche, David; Giddings, John; Brady, Joseph T; Anderson, Timothy

    2012-07-01

    Pregabalin increased the incidence of hemangiosarcomas in carcinogenicity studies of 2-year mice but was not tumorigenic in rats. Serum bicarbonate increased within 24 h of pregabalin administration in mice and rats. Rats compensated appropriately, but mice developed metabolic alkalosis and increased blood pH. Local tissue hypoxia and increased endothelial cell proliferation were also confirmed in mice alone. The combination of hypoxia and sustained increases in endothelial cell proliferation, angiogenic growth factors, dysregulated erythropoiesis, and macrophage activation is proposed as the key event in the mode of action (MOA) for hemangiosarcoma formation. Hemangiosarcomas occur spontaneously in untreated control mice but occur only rarely in humans. The International Programme on Chemical Safety and International Life Sciences Institute developed a Human Relevance Framework (HRF) analysis whereby presence or absence of key events can be used to assess human relevance. The HRF combines the MOA with an assessment of biologic plausibility in humans to assess human relevance. This manuscript compares the proposed MOA with Hill criteria, a component of the HRF, for strength, consistency, specificity, temporality, and dose response, with an assessment of key biomarkers in humans, species differences in response to disease conditions, and spontaneous incidence of hemangiosarcoma to evaluate human relevance. Lack of key biomarker events in the MOA in rats, monkeys, and humans supports a species-specific process and demonstrates that the tumor findings in mice are not relevant to humans at the clinical dose of pregabalin. Based on this collective dataset, clinical use of pregabalin would not pose an increased risk for hemangiosarcoma to humans.

  14. Stochastic simulations of the tetracycline operon

    Science.gov (United States)

    2011-01-01

    Background The tetracycline operon is a self-regulated system. It is found naturally in bacteria where it confers resistance to antibiotic tetracycline. Because of the performance of the molecular elements of the tetracycline operon, these elements are widely used as parts of synthetic gene networks where the protein production can be efficiently turned on and off in response to the presence or the absence of tetracycline. In this paper, we investigate the dynamics of the tetracycline operon. To this end, we develop a mathematical model guided by experimental findings. Our model consists of biochemical reactions that capture the biomolecular interactions of this intriguing system. Having in mind that small biological systems are subjects to stochasticity, we use a stochastic algorithm to simulate the tetracycline operon behavior. A sensitivity analysis of two critical parameters embodied this system is also performed providing a useful understanding of the function of this system. Results Simulations generate a timeline of biomolecular events that confer resistance to bacteria against tetracycline. We monitor the amounts of intracellular TetR2 and TetA proteins, the two important regulatory and resistance molecules, as a function of intrecellular tetracycline. We find that lack of one of the promoters of the tetracycline operon has no influence on the total behavior of this system inferring that this promoter is not essential for Escherichia coli. Sensitivity analysis with respect to the binding strength of tetracycline to repressor and of repressor to operators suggests that these two parameters play a predominant role in the behavior of the system. The results of the simulations agree well with experimental observations such as tight repression, fast gene expression, induction with tetracycline, and small intracellular TetR2 amounts. Conclusions Computer simulations of the tetracycline operon afford augmented insight into the interplay between its molecular

  15. Stochastic simulations of the tetracycline operon

    Directory of Open Access Journals (Sweden)

    Kaznessis Yiannis N

    2011-01-01

    Full Text Available Abstract Background The tetracycline operon is a self-regulated system. It is found naturally in bacteria where it confers resistance to antibiotic tetracycline. Because of the performance of the molecular elements of the tetracycline operon, these elements are widely used as parts of synthetic gene networks where the protein production can be efficiently turned on and off in response to the presence or the absence of tetracycline. In this paper, we investigate the dynamics of the tetracycline operon. To this end, we develop a mathematical model guided by experimental findings. Our model consists of biochemical reactions that capture the biomolecular interactions of this intriguing system. Having in mind that small biological systems are subjects to stochasticity, we use a stochastic algorithm to simulate the tetracycline operon behavior. A sensitivity analysis of two critical parameters embodied this system is also performed providing a useful understanding of the function of this system. Results Simulations generate a timeline of biomolecular events that confer resistance to bacteria against tetracycline. We monitor the amounts of intracellular TetR2 and TetA proteins, the two important regulatory and resistance molecules, as a function of intrecellular tetracycline. We find that lack of one of the promoters of the tetracycline operon has no influence on the total behavior of this system inferring that this promoter is not essential for Escherichia coli. Sensitivity analysis with respect to the binding strength of tetracycline to repressor and of repressor to operators suggests that these two parameters play a predominant role in the behavior of the system. The results of the simulations agree well with experimental observations such as tight repression, fast gene expression, induction with tetracycline, and small intracellular TetR2 amounts. Conclusions Computer simulations of the tetracycline operon afford augmented insight into the

  16. Response of captive skunks to microencapsulated tetracycline.

    Science.gov (United States)

    Schmit, Brandon S; Primus, Thomas M; Hurley, Jerome C; Kohler, Dennis J; Graves, Shawna F

    2010-07-01

    A captive striped skunk (Mephitis mephitis) study was conducted between February and June 2004 at the United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services National Wildlife Research Center, Fort Collins, Colorado, USA. The main objective was to determine the percentage of adult striped skunks that were marked after consuming placebo oral rabies vaccine (ORV) baits containing 100 mg of an experimental microencapsulated (coated microparticle) tetracycline hydrochloride biomarker. Biomarkers were identified in the canine teeth and mandibles of five of five skunks that consumed an ORV bait. A second objective was to determine if the microencapsulated tetracycline was resistant to photochemical conversion from tetracycline to epitetracycline. After 15 days of exposure, conversion from tetracycline to epitetracycline concentration in the microencapsulated product (mean 1.9% conversion, SD=1.24) was significantly less (P=0.006) than the pure-grade tetracycline powder (mean 7.5% conversion, SD=1.37). Results support the use of microencapsulated tetracycline hydrochloride as a biomarker in circumstances where the use of conventional powdered tetracycline hydrochloride is not feasible due to ORV bait design constraints.

  17. Tetracycline consumption and occurrence of tetracycline resistance in Salmonella typhimurium phage types from Danish pigs

    DEFF Research Database (Denmark)

    Emborg, Hanne-Dorthe; Vigre, Håkan; Jensen, Vibeke Frøkjær

    2007-01-01

    The aims of the present study were to investigate at the farm-owner level the effect of prescribed tetracycline consumption in pigs and different Salmonella Typhimurium phage types on the probability that the S. Typhimurium was resistant to tetracycline. In this study, 1,307 isolates were included...... was strongly associated with tetracycline resistance. A further analysis of data from the Danish Integrated Antimicrobial Resistance Monitoring and Research Programme (DANMAP) indicates that the tetracycline-susceptible phage types only slowly become tetracycline resistant, although tetracycline consumption......, originating from 877 farm owners, and data were analyzed using logistic regression. The analysis showed that both the S. Typhimurium phage type (p resistance. In particular, the phage type...

  18. 21 CFR 556.720 - Tetracycline.

    Science.gov (United States)

    2010-04-01

    ..., FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.720 Tetracycline. (a) Acceptable daily intake (ADI). The ADI for total... tissues of calves, swine, sheep, chickens, and turkeys, of 2 parts per million (ppm) in muscle, 6 ppm in...

  19. Development of a radioimmunoassay of tetracycline and its derivatives

    International Nuclear Information System (INIS)

    Zitzewitz, A. von.

    1981-01-01

    A radioimmunoassay for tetracycline was developed in the context of the present work. The determination of tetracycline content in biological samples is to be made valid using tetracycline RIA. As well as the carbodiimide method, a by radioimmunologists extremely seldomly used way involving a condensation reaction between protein and haptene via the Mannich reaction was successfully applied. Antibodies were produced using a conventional immunisation method after Abraham, the other applied alternative method after Vaitukaitis et al. The general working methods had to be adapted to the tetracycline RIA. All variable parameters of the antigen-antibody bond were tested to optimize the incubation conditions of the system as well as to control the tracer for a degradation. The detection limit of RIA is 10 - 12 , the measuring range from 10 - 12 to 10 - 10 mol for tetracycline hydrochloride and rolitetracycline respectively and up to 10 - 9 mol for its derivates. The investigations for cross reactions showed a high specificity for tetracycline (100%) and its intravenously appliable pyrrolidino-methyl derivative rolitetracycline (88%). Standard curves could be drawn up using either of the two compounds tetracycline and rolitetracycline as standard. The pharmaco-kinetic behaviour of the parenteral administrable tetracycline was analyzed as example for the possible applications of the tetracycline radioimmunoassay. Parallel animal tests administring 3 H tetracycline hydrochloride were performed for radioimmunoassay reference. The possible application of tetracycline radioimmunoassay in food analysis is discussed. (orig./MG) [de

  20. Sorption of tetracycline on organo-montmorillonites

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Niu; Wang, Ming-xia; Liu, Ming-ming; Liu, Fan [College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Weng, Liping [Department of Soil Quality, Wageningen University, P.O. Box 8005, 6700 EC, Wagneningen (Netherlands); Koopal, Luuk K. [Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen (Netherlands); Tan, Wen-feng, E-mail: wenfeng.tan@hotmail.com [College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shanxi 712100 (China)

    2012-07-30

    Highlights: Black-Right-Pointing-Pointer The sorption capacity of tetracycline on Mont. modified with QACs was highly promoted. Black-Right-Pointing-Pointer Tetracycline adsorbed on organoclay was affected by the amount and the length of QACs. Black-Right-Pointing-Pointer Tetracycline adsorption on organoclay exhibited high pH-dependence below 5. - Abstract: Tetracycline (TC) is a veterinary antibiotic that is frequently detected as pollutant in the environment. Powerful adsorbents are required for removing TC. The present paper compares the TC adsorption capacity of Na-montmorillonite (Na-mont) with six organo-montmorillonites (organo-monts). Three quaternary ammonium cations (QACs) with different alkyl-chain lengths were used as modifiers. Powder X-ray diffraction indicated that the d{sub 001} values of organo-monts increased with increasing the QACs loading and alkyl-chain length. The CECs of the organo-monts were substantially lower than that of Na-mont and decreased with QACs chain length and increased loading. The modeling of the adsorption kinetics revealed that the processes of TC adsorption on the tested samples could be well fitted by the pseudo-second-order equation. The maximum adsorption capacities of TC on the organo-monts (1000-2000 mmol/kg) were considerably higher than that on Na-mont (769 mmol/kg). Both the Langmuir and Freundlich model could fit the adsorption isotherms. The TC adsorption to the organo-monts increase significantly with decreasing the pH below 5.5 because of the electrostatic interaction, and a high QACs loading performed better than a low loading at around pH 3.

  1. Association Between Tetracycline Consumption and Tetracycline Resistance in Escherichia coli from Healthy Danish Slaughter Pigs

    DEFF Research Database (Denmark)

    Vieira, Antonio; Houe, Hans; Wegener, Henrik Caspar

    2009-01-01

    the intestinal tract of healthy pigs and patterns of tetracycline Consumption in the herds of origin, together with other risk factors. Data oil antimicrobial resistance, antimicrobial consumption, and pig herd demographics were obtained from different Danish surveillance programs. Descriptive statistics were......It has been recognized that exposure to antimicrobial agents can exert a selective pressure for the emergence of antimicrobial resistance. The objective of this study was to investigate an association between the probability of isolating a tetracycline-resistant Escherichia coli isolate from...... Susceptibility status were number of produced animals in the year and year of sampling. Other antimicrobial consumption risk factors, Such as number of prescriptions and amount prescribed, although not included in the final model, presented indirect impact in the tetracycline resistance probability. From...

  2. The collective actions in the form of cooperatives and the relevance in the soy production chain in Paraná

    Directory of Open Access Journals (Sweden)

    Lediany Freitas de Campos

    2017-08-01

    Full Text Available The aim of this study is to discuss the influence of collective actions, with a focus on cooperatives located on the soy production chain. It was noted that rural producers organize themselves in groups aiming to preserve their common interests, when they know they would succeed to act individually. The actions are performed by latent groups, through economic incentives, and there is strong influence of institutional environment. Collective cooperation results in benefits to all involved, in addition to generating positive externalities upstream and downstream on the chain. Cooperatives have had intense influence on the soy production in the State of Paraná, being responsible for a significant portion of the production, processing and distribution. By means of cooperatives, the state has maintained second position at national level in relation to the production of soy, with revealed comparative advantage, has gotten improvements in productivity and conquest of foreign markets.

  3. Interaction of nonsteroidal anti-inflammatory drugs with membranes: in vitro assessment and relevance for their biological actions.

    Science.gov (United States)

    Pereira-Leite, Catarina; Nunes, Cláudia; Reis, Salette

    2013-10-01

    Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used drugs in the world due to their anti-inflammatory, analgesic and antipyretic properties. Nevertheless, the consumption of these drugs is still associated with the occurrence of a wide spectrum of adverse effects. Regarding the major role of membranes in cellular events, the hypothesis that the biological actions of NSAIDs may be related to their effect at the membrane level has triggered the in vitro assessment of NSAIDs-membrane interactions. The use of membrane mimetic models, cell cultures, a wide range of experimental techniques and molecular dynamics simulations has been providing significant information about drugs partition and location within membranes and also about their effect on diverse membrane properties. These studies have indeed been providing evidences that the effect of NSAIDs at membrane level may be an additional mechanism of action and toxicity of NSAIDs. In fact, the pharmacokinetic properties of NSAIDs are closely related to the ability of these drugs to interact and overcome biological membranes. Moreover, the therapeutic actions of NSAIDs may also result from the indirect inhibition of cyclooxygenase due to the disturbing effect of NSAIDs on membrane properties. Furthermore, increasing evidences suggest that the disordering effects of these drugs on membranes may be in the basis of the NSAIDs-induced toxicity in diverse organ systems. Overall, the study of NSAIDs-membrane interactions has proved to be not only important for the better understanding of their pharmacological actions, but also for the rational development of new approaches to overcome NSAIDs adverse effects. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Protein nitration and nitrosylation by NO-donating aspirin in colon cancer cells: Relevance to its mechanism of action

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Jennie L.; Ji, Ping; Ouyang, Nengtai [Division of Cancer Prevention, Stony Brook University, HSC, T17-080, Stony Brook, NY 11794-8173 (United States); Kopelovich, Levy [Division of Cancer Prevention NCI, NIH, Bethesda, MD (United States); Rigas, Basil, E-mail: basil.rigas@stonybrook.edu [Division of Cancer Prevention, Stony Brook University, HSC, T17-080, Stony Brook, NY 11794-8173 (United States)

    2011-06-10

    Nitric oxide-donating aspirin (NO-ASA) is a promising agent for cancer prevention. Although studied extensively, its molecular targets and mechanism of action are still unclear. S-nitrosylation of signaling proteins is emerging as an important regulatory mechanism by NO. Here, we examined whether S-nitrosylation of the NF-{kappa}B, p53, and Wnt signaling proteins by NO-ASA might explain, in part, its mechanism of action in colon cancer. NO-ASA releases significant amounts of NO detected intracellularly in HCT116 and HT-29 colon cells. Using a modified biotin switch assay we demonstrated that NO-ASA S-nitrosylates the signaling proteins p53, {beta}-catenin, and NF-{kappa}B, in colon cancer cells in a time- and concentration-dependent manner. NO-ASA suppresses NF-{kappa}B binding to its cognate DNA oligonucleotide, which occurs without changes in the nuclear levels of the NF-{kappa}B subunits p65 and p50 and is reversed by dithiothreitol that reduces -S-NO to -SH. In addition to S-nitrosylation, we documented both in vitro and in vivo widespread nitration of tyrosine residues of cellular proteins in response to NO-ASA. Our results suggest that the increased intracellular NO levels following treatment with NO-ASA modulate cell signaling by chemically modifying key protein members of signaling cascades. We speculate that S-nitrosylation and tyrosine nitration are responsible, at least in part, for the inhibitory growth effect of NO-ASA on cancer cell growth and that this may represent a general mechanism of action of NO-releasing agents.

  5. Applicable or relevant and appropriate requirements (ARARs) for remedial actions at the Portsmouth Gaseous Diffusion Plant: A compendium of environmental laws and guidance

    International Nuclear Information System (INIS)

    Houlberg, L.M.; Eaton, L.A.; Martin, J.A.; McDonald, E.P.; Etnier, E.L.

    1992-02-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act of 1990 (CERCLA) specifies that remedial actions for cleanup of hazardous substances must comply with applicable or relevant and appropriate requirements (ARARs) or standards under federal and state environmental laws. Although the US Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS) has not at this time been proposed for inclusion on the US Environmental Protection Agency National Priorities List, under Sect. I of an administrative consent order signed by DOE and the US Environmental Protection Agency on September 29, 1989, effective October 4, 1989, any necessary response actions at PORTS stipulated in the administrative consent order must be performed in a manner consistent with the Resource Conservation and Recovery Act of 1976 and CERCLA. Section 121 of CERCLA calls for the preparation of a draft listing of all ARARs. This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at PORTS. A description of the terms ''applicable'' and ''relevant and appropriate'' is provided, as well as definitions of chemical-, location-, and action-specific ARARs. ARARs promulgated by the federal government and by the state of Ohio are listed in tables. In addition, the major provisions of the Resource Conservation and Recovery Act, Safe Drinking Water Act, Clean Water Act, and other acts, as they apply to hazardous waste cleanup, are discussed

  6. Complexometric-spectrophotometric assay of tetracyclines in drug formulations.

    Science.gov (United States)

    Sultan, S M; Alzamil, I Z; Alarfaj, N A

    1988-05-01

    An accurate, rapid and very simple spectrophotometric method for the assay of tetracyclines (tetracycline.HCl, chlorotetracycline.HCl, demeclocycline, oxytetracycline.HCl and doxycycline) has been developed. The method is based on the complexation of iron(III) with tetracyclines in 0.001M sulphuric acid. It has been successfully applied to the assay of tetracyclines in drug formulations, and the interferences of excipients have been examined. The results have been statistically compared with those obtained by two standard methods and found to be very satisfactory.

  7. Assessment of Tetracyclines Residues and Tetracycline Resistant Bacteria in Conventional and Organic Baby Foods.

    Science.gov (United States)

    Guarddon, Mónica; Miranda, José M; Vázquez, Beatriz I; Cepeda, Alberto; Franco, Carlos M

    2015-07-22

    Children are very vulnerable to bacterial infections and they are sometimes subject to antimicrobials for healing. The presence of resistance genes may counteract effects of antimicrobials. This work has thereby compared the amount of tetracycline resistance genes, tet (A) and tet (B), between conventional and organic meat-based or vegetable-based baby foods and used the quantification of these genes to assess the presence of tetracycline residues in these samples. Counts of bacteria harboring the tet (A) gene were higher than those containing tet (B), and there was no difference between the organic and the conventional samples. Samples with detectable amounts of tetracycline residues were also positive for the presence of tet genes, and when the presence of the genes was not detected, the samples were also negative for the presence of residues. The percentages of tetracycline residues were higher in organic samples than in conventional ones. It cannot be concluded that organic formulas are safer than conventional ones for the studied parameters.

  8. Differential pulse polarography of tetracycline: determination of complexing tendencies of tetracycline analogs in the presence of cations.

    Science.gov (United States)

    Jochsberger, T; Cutie, A; Mills, J

    1979-08-01

    The complexation tendencies, stoichiometries, and stability constants for tetracycline, minocycline, and demeclocycline with the metallic ions calcium(II), magnesium (II), zinc(II), aluminum(III), iron(II), and iron (III) were evaluated using a polarographic technique. Changes in pulse peak heights for each tetracycline deravative were measured as a function of cation concentration. The method provides an in vitro method of evaluating the selectivity of particular metal ions for different tetracycline analogs.

  9. Mode of action human relevance (species concordance) framework: Evolution of the Bradford Hill considerations and comparative analysis of weight of evidence

    Science.gov (United States)

    Meek, M E (Bette); Palermo, Christine M; Bachman, Ammie N; North, Colin M; Jeffrey Lewis, R

    2014-01-01

    The mode of action human relevance (MOA/HR) framework increases transparency in systematically considering data on MOA for end (adverse) effects and their relevance to humans. This framework continues to evolve as experience increases in its application. Though the MOA/HR framework is not designed to address the question of “how much information is enough” to support a hypothesized MOA in animals or its relevance to humans, its organizing construct has potential value in considering relative weight of evidence (WOE) among different cases and hypothesized MOA(s). This context is explored based on MOA analyses in published assessments to illustrate the relative extent of supporting data and their implications for dose–response analysis and involved comparisons for chemical assessments on trichloropropane, and carbon tetrachloride with several hypothesized MOA(s) for cancer. The WOE for each hypothesized MOA was summarized in narrative tables based on comparison and contrast of the extent and nature of the supporting database versus potentially inconsistent or missing information. The comparison was based on evolved Bradford Hill considerations rank ordered to reflect their relative contribution to WOE determinations of MOA taking into account increasing experience in their application internationally. This clarification of considerations for WOE determinations as a basis for comparative analysis is anticipated to contribute to increasing consistency in the application of MOA/HR analysis and potentially, transparency in separating science judgment from public policy considerations in regulatory risk assessment. Copyright © 2014. The Authors. Journal of Applied Toxicology Published by John Wiley & Sons Ltd. The potential value of the mode of action (MOA)/human relevance (species concordance) framework in considering relative weight of evidence (WOE) amongst different cases and hypothesized MOA(s) is explored based on the content of several published assessments

  10. Comparison of kinetics of active tetracycline uptake and active tetracycline efflux in sensitive and plasmid RP4-containing Pseudomonas putida.

    OpenAIRE

    Hedstrom, R C; Crider, B P; Eagon, R G

    1982-01-01

    Membrane vesicles prepared from tetracycline-sensitive cells of Pseudomonas putida took up tetracycline by an active transport system with an apparent Km of 2.5 mM and a Vmax of 50 nmol min-1 mg protein-1. In contrast, resistance determinant RP4-containing P. putida had an active high-affinity efflux system for tetracycline with a Km of 2.0 to 3.54 microM and a Vmax of 0.15 nmol min-1 mg protein-1. Thus, the efflux system of tetracycline-resistant P. putida(RP4) had an average of 1,000-fold g...

  11. Genetic structure of Barbus spp. populations in the Marches Region of central Italy and its relevance to conservation actions.

    Science.gov (United States)

    Livi, S; de Innocentiis, S; Longobardi, A; Cataudella, S; Tancioni, L; Rampacci, M; Marino, G

    2013-03-01

    A genetic survey of Barbus spp. populations in the Marches Region (Adriatic River basins), central Italy, was carried out using mitochondrial and nuclear markers (partial D-loop, cyt b sequences and microsatellite loci) in order to ascertain their systematic position and to address their genetic structure which is key to conservation action planning. Analyses were conducted on sequences obtained from 91 individuals collected from eight sampling sites in five different rivers, from two specimens provided by the Ichthyological Centre of Rome and mitochondrial sequences of Barbus spp. retrieved from GenBank. Presumptive classification based on external morphological characters was not confirmed by genetic analysis, by means of which all specimens collected in the Marches Region were ascribed to Barbus plebejus. Genetic diversity values (h and π) of sampling groups were all different from 0 except the one sample collected from the upper reaches of the River Tenna, above a hydroelectric dam. Population connectivity and colonization patterns of the studied area were inferred from an analysis of molecular variance distribution and evolutionary relationships among haplotypes. The results point to different levels of isolation among sampling groups due to ecological and anthropogenic factors and the effect of an artificial barrier on genetic variability and conservation status of the population. Finally, this study confirms the uncertainty associated with systematic classification of Barbus spp. based on morphological characters due to the phenotypic plasticity of the species. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

  12. Applicable or relevant and appropriate requirements (ARARs) for remedial actions at the Paducah Gaseous Diffusion Plant: A compendium of environmental laws and guidance. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Etnier, E.L.; Eaton, L.A. [Oak Ridge National Lab., TN (United States)

    1992-03-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances found at sites placed on the National Priorities List (NPL) by the US Environmental Protection Agency (EPA) must comply with applicable or relevant and appropriate requirements (ARARs) or standards under federal and state environmental laws. To date, the US Department of Energy (DOE) Paducah Gaseous Diffusion Plant (PGDP) has not been on the NPL. Although DOE and EPA have entered into an Administrative Consent Order (ACO), the prime regulatory authority for cleanup at PGDP will be the Resource Conservation and Recovery Act (RCRA). This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at PGDP in the event that the plant becomes included on the NPL or the ACO is modified to include CERCLA cleanup. A description of the terms ``applicable`` and ``relevant and appropriate`` is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Kentucky are listed in tables. In addition, the major provisions of RCRA, the Safe Drinking Water Act, the Clean Water Act, the Clean Air Act, and other acts, as they apply to hazardous and radioactive waste cleanup, are discussed.

  13. Applicable or relevant and appropriate requirements (ARARs) for remedial actions at the Paducah Gaseous Diffusion Plant: A compendium of environmental laws and guidance

    Energy Technology Data Exchange (ETDEWEB)

    Etnier, E.L.; Eaton, L.A. (Oak Ridge National Lab., TN (United States))

    1992-03-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances found at sites placed on the National Priorities List (NPL) by the US Environmental Protection Agency (EPA) must comply with applicable or relevant and appropriate requirements (ARARs) or standards under federal and state environmental laws. To date, the US Department of Energy (DOE) Paducah Gaseous Diffusion Plant (PGDP) has not been on the NPL. Although DOE and EPA have entered into an Administrative Consent Order (ACO), the prime regulatory authority for cleanup at PGDP will be the Resource Conservation and Recovery Act (RCRA). This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at PGDP in the event that the plant becomes included on the NPL or the ACO is modified to include CERCLA cleanup. A description of the terms applicable'' and relevant and appropriate'' is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Kentucky are listed in tables. In addition, the major provisions of RCRA, the Safe Drinking Water Act, the Clean Water Act, the Clean Air Act, and other acts, as they apply to hazardous and radioactive waste cleanup, are discussed.

  14. Applicable or relevant and appropriate requirements (ARARs) for remedial actions at the Paducah Gaseous Diffusion Plant: A compendium of environmental laws and guidance

    International Nuclear Information System (INIS)

    Etnier, E.L.; Eaton, L.A.

    1992-03-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances found at sites placed on the National Priorities List (NPL) by the US Environmental Protection Agency (EPA) must comply with applicable or relevant and appropriate requirements (ARARs) or standards under federal and state environmental laws. To date, the US Department of Energy (DOE) Paducah Gaseous Diffusion Plant (PGDP) has not been on the NPL. Although DOE and EPA have entered into an Administrative Consent Order (ACO), the prime regulatory authority for cleanup at PGDP will be the Resource Conservation and Recovery Act (RCRA). This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at PGDP in the event that the plant becomes included on the NPL or the ACO is modified to include CERCLA cleanup. A description of the terms ''applicable'' and ''relevant and appropriate'' is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Kentucky are listed in tables. In addition, the major provisions of RCRA, the Safe Drinking Water Act, the Clean Water Act, the Clean Air Act, and other acts, as they apply to hazardous and radioactive waste cleanup, are discussed

  15. Ceftriaxone and tetracycline effect on biofilm-formation strains of Staphylococcus epidermidis

    Directory of Open Access Journals (Sweden)

    O. I. Sidashenko

    2014-04-01

    ceftriaxone – 20 mg/ml and for tetracycline – 2 mg/ml, MIC of ceftriaxone for S. epidermidis C strain – 24 mg/ml, MIC of tetracycline – 1.5 mg/ml. The effect of ceftriaxone and tetracycline was defined to the larger extent, than MIC for biofilm-forming on the plate (10, 50 and 100 times. More effective action of tetracycline was shown for 1- and 2-daily biofilm cultures of S. epidermidis clinical strain. Adding tetracycline concentration of 20 mg/ml in the culture medium of the 1-day biofilm of S. epidermidis Cl strain reduced the cell number of biofilm formation 590 times, increasing concentrations of tetracycline to 100 mg/ml and added to the 1-day biofilm of the clinical strain reduced the number of bacterial cell 4400 times compared with control.

  16. How Epigallocatechin-3-gallate and Tetracycline Interact with the Josephin Domain of Ataxin-3 and Alter Its Aggregation Mode.

    Science.gov (United States)

    Bonanomi, Marcella; Visentin, Cristina; Natalello, Antonino; Spinelli, Michela; Vanoni, Marco; Airoldi, Cristina; Regonesi, Maria E; Tortora, Paolo

    2015-12-07

    Epigallocatechin-3-gallate (EGCG) and tetracycline are two known inhibitors of amyloid aggregation able to counteract the fibrillation of most of the proteins involved in neurodegenerative diseases. We have recently investigated their effect on ataxin-3 (AT3), the polyglutamine-containing protein responsible for spinocerebellar ataxia type 3. We previously showed that EGCG and tetracycline can contrast the aggregation process and toxicity of expanded AT3, although by different mechanisms. Here, we have performed further experiments by using the sole Josephin domain (JD) to further elucidate the mechanism of action of the two compounds. By protein solubility assays and FTIR spectroscopy we have first observed that EGCG and tetracycline affect the JD aggregation essentially in the same way displayed when acting on the full-length expanded AT3. Then, by saturation transfer difference (STD) NMR experiments, we have shown that EGCG binds both the monomeric and the oligomeric JD form, whereas tetracycline can only interact with the oligomeric one. Surface plasmon resonance (SPR) analysis has confirmed the capability of the sole EGCG to bind monomeric JD, although with a KD value suggestive for a non-specific interaction. Our investigations provide new details on the JD interaction with EGCG and tetracycline, which could explain the different mechanisms by which the two compounds reduce the toxicity of AT3. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Transfer of tetracycline resistance gene (tetr) between replicons in ...

    African Journals Online (AJOL)

    Antimicrobial susceptibility testing among the isolates showed resistance to amoxicillin (92%), amoxicillin-clavulanic acid (84.4%), tetracycline (71.4%), gentamycin (43.5%), nalidixic acid (38.3%) and nitrofurantoin (7.9%). E. coli showed the highest resistance to most of the antibiotics. Tetracycline resistance gene was ...

  18. Investigation of the Genetic Basis of Tetracycline Resistance in ...

    African Journals Online (AJOL)

    Purpose: To determine the prevalence and genetic basis of tetracycline resistance in Staphylococcus aureus. Methods: One hundred and thirty (130) clinical isolates of S. aureus were collected from Khyber Teaching Hospital, Peshawar, Pakistan. Susceptibility to antibiotics (doxycycline, tetracycline and minocycline) was ...

  19. Investigation of the Genetic Basis of Tetracycline Resistance in ...

    African Journals Online (AJOL)

    Purpose: To determine the prevalence and genetic basis of tetracycline resistance in Staphylococcus aureus. Methods: One hundred and thirty (130) clinical isolates of S. aureus were collected from Khyber Teaching. Hospital, Peshawar, Pakistan. Susceptibility to antibiotics (doxycycline, tetracycline and minocycline) was.

  20. Tetracycline tooth discolouration in Benin City | Sede | Journal of ...

    African Journals Online (AJOL)

    In 29.5% of the patients, hypoplasia was associated with tetracycline discolouration. Of these, 71.4% were observed in the category with severe discolouration of teeth. A non-genetic pattern of tetracycline tooth discolouration was observed in 40.7% of the patients, with discolouration in sibling\\'s only accounting for 51.5% of ...

  1. Ligand Binding Domain Protein in Tetracycline-Inducible Expression

    African Journals Online (AJOL)

    Purpose: To investigate tetracycline-inducible expression system for producing clinically usable, highquality liver X receptor ligand-binding domain recombinant protein. Methods: In this study, we have expressed and purified the recombinant liver X receptor β-ligand binding domain proteins in E. coli using a tetracycline ...

  2. Tetracycline residues and tetracycline resistance genes in groundwater impacted by swine production facilities

    Science.gov (United States)

    Mackie, R.I.; Koike, S.; Krapac, I.; Chee-Sanford, J.; Maxwell, Susan; Aminov, R.I.

    2006-01-01

    Antibiotics are used at therapeutic levels to treat disease; at slightly lower levels as prophylactics; and at low, subtherapeutic levels for growth promotion and improvement of feed efficiency. Over 88% of swine producers in the United States gave antimicrobials to grower/finisher pigs in feed as a growth promoter in 2000. It is estimated that ca. 75% of antibiotics are not absorbed by animals and are excreted in urine and feces. The extensive use of antibiotics in swine production has resulted in antibiotic resistance in many intestinal bacteria, which are also excreted in swine feces, resulting in dissemination of resistance genes into the environment.To assess the impact of manure management on groundwater quality, groundwater samples have been collected near two swine confinement facilities that use lagoons for manure storage and treatment. Several key contaminant indicators-including inorganic ions, antibiotics, and antibiotic resistance genes-were analyzed in groundwater collected from the monitoring wells. Chloride, ammonium, potassium, and sodium were predominant inorganic constituents in the manure samples and served as indicators of groundwater contamination. Based on these analyses, shallow groundwater has been impacted by lagoon seepage at both sites. Liquid chromatography-mass spectroscopy (LC-MS) was used to measure the dissolved concentrations of tetracycline, chlortetracycline, and oxytetracycline in groundwater and manure. Although tetracyclines were regularly used at both facilities, they were infrequently detected in manure samples and then at relatively trace concentrations. Concentrations of all tetracyclines and their breakdown products in the groundwater sampled were generally less than 0.5 ??g/L.Bacterial tetracycline resistance genes served as distinct genotypic markers to indicate the dissemination and mobility of antibiotic resistance genes that originated from the lagoons. Applying PCR to genomic DNA extracted from the lagoon and

  3. Applicable or Relevant and Appropriate Requirements (ARARs) for Remedial Action at the Oak Ridge Reservation: A compendium of major environmental laws

    International Nuclear Information System (INIS)

    Etnier, E.L.; McDonald, E.P.; Houlberg, L.M.

    1993-07-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances must comply with applicable or relevant and appropriate requirements (ARARS) or standards under federal and state environmental laws. The US Department of Energy (DOE) Oak Ridge Reservation (ORR) was placed on the National Priorities List by the US Environmental Protection Agency (EPA) on November 21, 1989, effective December 21, 1989. As a result of this listing, DOE, EPA, and the Tennessee Department of Environment and Conservation have signed a Federal Facility Agreement (FFA) for the environmental restoration of the ORR. Section XXI(F) of the FFA calls for the preparation of a draft listing of all ARARs as mandated by CERCLA section 121. This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at the ORR. A description of the terms ''applicable'' and ''relevant and appropriate'' is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Tennessee are listed in tables. In addition, the major provisions of the Resource Conservation and Recovery Act, the Safe Drinking Water Act, the Clean Water Act, the Clean Air and other acts, as they apply to hazardous waste cleanup, are discussed. In the absence of ARARS, CERCLA section 121 provides for the use of nonpromulgated federal criteria, guidelines, and advisories in evaluating the human risk associated with remedial action alternatives. Such nonpromulgated standards are classified as ''to-be-considered'' (TBC) guidance. A ion of available guidance is given; summary tables fist the available federal standards and guidance information. In addition, the substantive contents of the DOE orders as they apply to remediation of radioactively contaminated sites are discussed as TBC guidance

  4. Applicable or Relevant and Appropriate Requirements (ARARs) for Remedial Action at the Oak Ridge Reservation: A compendium of major environmental laws. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Etnier, E.L.; McDonald, E.P.; Houlberg, L.M.

    1993-07-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances must comply with applicable or relevant and appropriate requirements (ARARS) or standards under federal and state environmental laws. The US Department of Energy (DOE) Oak Ridge Reservation (ORR) was placed on the National Priorities List by the US Environmental Protection Agency (EPA) on November 21, 1989, effective December 21, 1989. As a result of this listing, DOE, EPA, and the Tennessee Department of Environment and Conservation have signed a Federal Facility Agreement (FFA) for the environmental restoration of the ORR. Section XXI(F) of the FFA calls for the preparation of a draft listing of all ARARs as mandated by CERCLA {section}121. This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at the ORR. A description of the terms ``applicable`` and ``relevant and appropriate`` is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Tennessee are listed in tables. In addition, the major provisions of the Resource Conservation and Recovery Act, the Safe Drinking Water Act, the Clean Water Act, the Clean Air and other acts, as they apply to hazardous waste cleanup, are discussed. In the absence of ARARS, CERCLA {section}121 provides for the use of nonpromulgated federal criteria, guidelines, and advisories in evaluating the human risk associated with remedial action alternatives. Such nonpromulgated standards are classified as ``to-be-considered`` (TBC) guidance. A ion of available guidance is given; summary tables fist the available federal standards and guidance information. In addition, the substantive contents of the DOE orders as they apply to remediation of radioactively contaminated sites are discussed as TBC guidance.

  5. Effect of pasteurization on the residues of tetracyclines in milk

    Directory of Open Access Journals (Sweden)

    Eva Kellnerová

    2014-01-01

    Full Text Available The main aim of this work was to determine the effect of high pasteurization of milk (85 °C/3 s on the residues of tetracycline and oxytetracycline. The samples of raw cow’s milk, purchased from a vending machine, were spiked with standard solutions of tetracycline and oxytetracycline. The content of the residues of tetracycline antibiotics was measured before and after heating. Pre-cleaned samples were extracted by a mixed-mode solid phase extraction technique and analysed using high performance liquid chromatography/diode array detection. Whereas the residues of tetracycline decreased only by 5.74% and were not significantly different (P > 0.05, the residues of oxytetracycline decreased by 15.3% and this distinction was highly significant (P ≤ 0.01. Based on the results of our study, the tetracycline antibiotics were proved to have differences in the thermostability of particular substances at pasteurisation temperatures.

  6. Mode of action human relevance (species concordance) framework: Evolution of the Bradford Hill considerations and comparative analysis of weight of evidence.

    Science.gov (United States)

    Meek, M E Bette; Palermo, Christine M; Bachman, Ammie N; North, Colin M; Jeffrey Lewis, R

    2014-06-01

    The mode of action human relevance (MOA/HR) framework increases transparency in systematically considering data on MOA for end (adverse) effects and their relevance to humans. This framework continues to evolve as experience increases in its application. Though the MOA/HR framework is not designed to address the question of "how much information is enough" to support a hypothesized MOA in animals or its relevance to humans, its organizing construct has potential value in considering relative weight of evidence (WOE) among different cases and hypothesized MOA(s). This context is explored based on MOA analyses in published assessments to illustrate the relative extent of supporting data and their implications for dose-response analysis and involved comparisons for chemical assessments on trichloropropane, and carbon tetrachloride with several hypothesized MOA(s) for cancer. The WOE for each hypothesized MOA was summarized in narrative tables based on comparison and contrast of the extent and nature of the supporting database versus potentially inconsistent or missing information. The comparison was based on evolved Bradford Hill considerations rank ordered to reflect their relative contribution to WOE determinations of MOA taking into account increasing experience in their application internationally. This clarification of considerations for WOE determinations as a basis for comparative analysis is anticipated to contribute to increasing consistency in the application of MOA/HR analysis and potentially, transparency in separating science judgment from public policy considerations in regulatory risk assessment. Copyright © 2014. The Authors. Journal of Applied Toxicology Published by John Wiley & Sons Ltd.

  7. Tetracycline is back. Three-step tetracycline-biotin tumour targeting

    International Nuclear Information System (INIS)

    Salehi, N.; Lichtenstein, M.

    1998-01-01

    Full text: In the 1960s, investigators attempted to use radiolabelled tetracycline for the detection of tumours. This was limited by bone and gastrointestinal uptake. The monoclonal antibody Avidin Biotin technology has been used for 10 years to target tumours. We have improved a novel mechanism using three step targeting, to demonstrate tumour cells in (C57B1/6X balb-c) F1 mice with subcutaneously implanted E-3 thymoma. The three steps were (1) i.p. injection of Biotin Tetracycline conjugate (t:1) ratio, (2) 96 h later Avidin was injected, and (3) 24 h after (2) 99m Tc-CDTPA-Biotin was injected. Avidin has four high affinity (Km 10-15) Biotin binding sites, hence step (2) couples the Avidin to Tetracycline-Biotin in the tumour. The Avidin then provides a high affinity target for the otherwise rapidly urinary excreted 99m Tc-CDTPA-Biotin. Mice were sacrificed 16-24h after (3) by cervical dislocation. Biodistribution of radioactivity tumour to blood, liver, bone and stomach were: T:BL= 7.2, T:LI= 3.35, TBO= 9.65, T:ST= 0.93. The percentage of injected dose/g was T = 4.49%, BL = 0.62%. E-3 Thymoma is a rapid growing tumour. At day 1 (step 1) the tumour size was 0.45 cm, six days later (step 3) each dimension was doubled. Hence, percentage of injected dose per gram is artefactually reduced eight-fold. With a slowly growing tumour using the same method the results may be better. The conclusions reached are that Tetracycline-Biotin 3-stage method of tumour targeting is worthy of further development

  8. Tetracycline is back. Three-step tetracycline-biotin tumour targeting

    Energy Technology Data Exchange (ETDEWEB)

    Salehi, N.; Lichtenstein, M. [Royal Melbourne Hospital, Parkville, VIC (Australia). Dept. of Nuclear Medicine

    1998-03-01

    Full text: In the 1960s, investigators attempted to use radiolabelled tetracycline for the detection of tumours. This was limited by bone and gastrointestinal uptake. The monoclonal antibody Avidin Biotin technology has been used for 10 years to target tumours. We have improved a novel mechanism using three step targeting, to demonstrate tumour cells in (C57B1/6X balb-c) F1 mice with subcutaneously implanted E-3 thymoma. The three steps were (1) i.p. injection of Biotin Tetracycline conjugate (t:1) ratio, (2) 96 h later Avidin was injected, and (3) 24 h after (2) {sup 99m}Tc-CDTPA-Biotin was injected. Avidin has four high affinity (Km 10-15) Biotin binding sites, hence step (2) couples the Avidin to Tetracycline-Biotin in the tumour. The Avidin then provides a high affinity target for the otherwise rapidly urinary excreted {sup 99m}Tc-CDTPA-Biotin. Mice were sacrificed 16-24h after (3) by cervical dislocation. Biodistribution of radioactivity tumour to blood, liver, bone and stomach were: T:BL= 7.2, T:LI= 3.35, TBO= 9.65, T:ST= 0.93. The percentage of injected dose/g was T = 4.49%, BL = 0.62%. E-3 Thymoma is a rapid growing tumour. At day 1 (step 1) the tumour size was 0.45 cm, six days later (step 3) each dimension was doubled. Hence, percentage of injected dose per gram is artefactually reduced eight-fold. With a slowly growing tumour using the same method the results may be better. The conclusions reached are that Tetracycline-Biotin 3-stage method of tumour targeting is worthy of further development.

  9. Diuron-induced rat urinary bladder carcinogenesis: mode of action and human relevance evaluations using the International Programme on Chemical Safety framework.

    Science.gov (United States)

    Da Rocha, Mitscheli Sanches; Arnold, Lora L; De Oliveira, Maria Luiza Cotrim Sartor; Catalano, Shadia M Ihlaseh; Cardoso, Ana Paula Ferragut; Pontes, Merielen G N; Ferrucio, Bianca; Dodmane, Puttappa R; Cohen, Samuel M; De Camargo, João Lauro V

    2014-05-01

    Diuron, a high volume substituted urea herbicide, induced high incidences of urinary bladder carcinomas and low incidences of kidney pelvis papillomas and carcinomas in rats exposed to high doses (2500 ppm) in a 2-year bioassay. Diuron is registered for both occupational and residential uses and is used worldwide for more than 30 different crops. The proposed rat urothelial mode of action (MOA) for this herbicide consists of metabolic activation to metabolites that are excreted and concentrated in the urine, leading to cytotoxicity, urothelial cell necrosis and exfoliation, regenerative hyperplasia, and eventually tumors. We show evidence for this MOA for diuron using the International Programme on Chemical Safety (IPCS) conceptual framework for evaluating an MOA for chemical carcinogens, and the United States Environmental Protection Agency (USEPA) and IPCS framework for assessing human relevance.

  10. The relevance of social contexts and social action in reducing substance use and victimization among women participating in an HIV prevention intervention in Cape Town, South Africa

    Directory of Open Access Journals (Sweden)

    Reed E

    2013-06-01

    community on issues relevant to substance use prevention or other health topics promoted within the program, as well as outside social influences within women's life contexts (eg, support from non-substance using family or male partners, leaving male partners or other peer relationships characterized by drug use, or finding employment were key factors reported by women in terms of facilitating their substance use abstinence and in reducing women's exposures to victimization. Conclusion: Findings highlight the potential for group-delivered interventions that include mobilizing women to take social action in the larger community to be effective approaches for facilitating substance use abstinence, reductions in victimization, and ultimately, to address the intersection between substance use, violence, and HIV risk among women in this high HIV prevalence setting. Keywords: HIV prevention, substance use, social context, women

  11. Developing and evaluating interventions that are applicable and relevant to inpatients and those who care for them; a multiphase, pragmatic action research approach

    Science.gov (United States)

    2014-01-01

    Background Randomised controlled trials may be of limited use to evaluate the multidisciplinary and multimodal interventions required to effectively treat complex patients in routine clinical practice; pragmatic action research approaches may provide a suitable alternative. Methods A multiphase, pragmatic, action research based approach was developed to identify and overcome barriers to nutritional care in patients admitted to a metropolitan hospital hip-fracture unit. Results Four sequential action research cycles built upon baseline data including 614 acute hip-fracture inpatients and 30 purposefully sampled clinicians. Reports from Phase I identified barriers to nutrition screening and assessment. Phase II reported post-fracture protein-energy intakes and intake barriers. Phase III built on earlier results; an explanatory mixed-methods study expanded and explored additional barriers and facilitators to nutritional care. Subsequent changes to routine clinical practice were developed and implemented by the treating team between Phase III and IV. These were implemented as a new multidisciplinary, multimodal nutritional model of care. A quasi-experimental controlled, ‘before-and-after’ study was then used to compare the new model of care with an individualised nutritional care model. Engagement of the multidisciplinary team in a multiphase, pragmatic action research intervention doubled energy and protein intakes, tripled return home discharge rates, and effected a 75% reduction in nutritional deterioration during admission in a reflective cohort of hip-fracture inpatients. Conclusions This approach allowed research to be conducted as part of routine clinical practice, captured a more representative patient cohort than previously reported studies, and facilitated exploration of barriers and engagement of the multidisciplinary healthcare workers to identify and implement practical solutions. This study demonstrates substantially different findings to those

  12. Developing and evaluating interventions that are applicable and relevant to inpatients and those who care for them; a multiphase, pragmatic action research approach.

    Science.gov (United States)

    Bell, Jack J; Rossi, Tony; Bauer, Judith D; Capra, Sandra

    2014-08-18

    Randomised controlled trials may be of limited use to evaluate the multidisciplinary and multimodal interventions required to effectively treat complex patients in routine clinical practice; pragmatic action research approaches may provide a suitable alternative. A multiphase, pragmatic, action research based approach was developed to identify and overcome barriers to nutritional care in patients admitted to a metropolitan hospital hip-fracture unit. Four sequential action research cycles built upon baseline data including 614 acute hip-fracture inpatients and 30 purposefully sampled clinicians. Reports from Phase I identified barriers to nutrition screening and assessment. Phase II reported post-fracture protein-energy intakes and intake barriers. Phase III built on earlier results; an explanatory mixed-methods study expanded and explored additional barriers and facilitators to nutritional care. Subsequent changes to routine clinical practice were developed and implemented by the treating team between Phase III and IV. These were implemented as a new multidisciplinary, multimodal nutritional model of care. A quasi-experimental controlled, 'before-and-after' study was then used to compare the new model of care with an individualised nutritional care model. Engagement of the multidisciplinary team in a multiphase, pragmatic action research intervention doubled energy and protein intakes, tripled return home discharge rates, and effected a 75% reduction in nutritional deterioration during admission in a reflective cohort of hip-fracture inpatients. This approach allowed research to be conducted as part of routine clinical practice, captured a more representative patient cohort than previously reported studies, and facilitated exploration of barriers and engagement of the multidisciplinary healthcare workers to identify and implement practical solutions. This study demonstrates substantially different findings to those previously reported, and is the first to

  13. Dietary exposure to tetracycline residues through milk consumption in Iran

    OpenAIRE

    Aalipour, Fathollah; Mirlohi, Maryam; Jalali, Mohammad; Azadbakht, Leila

    2015-01-01

    Background The abundant use of tetracycline antibiotics in veterinary medicine may result in the presence of their residues in milk at unsafe concentrations that can adversely affect public health. The aim of the current study was to evaluate the risk of tetracycline residue (TET) intake via milk consumption amongst different age groups of human consumers in Iran. Methods To quantify the drug residues, HPLC analysis was performed under isocratic conditions using UV detection at 355?nm. Milk c...

  14. Novel bioassay using Bacillus megaterium to detect tetracycline in milk.

    Science.gov (United States)

    Tumini, Melisa; Nagel, Orlando G; Molina, Pilar; Althaus, Rafael L

    2016-01-01

    Tetracyclines are used for the prevention and control of dairy cattle diseases. Residues of these drugs can be excreted into milk. Thus, the aim of this study was to develop a microbiological method using Bacillus megaterium to detect tetracyclines (chlortetracycline, oxytetracycline and tetracycline) in milk. In order to approximate the limits of detection of the bioassay to the Maximum Residue Limit (100μg/l) for milk tetracycline, different concentrations of chloramphenicol (0, 1000, 1500 and 2000μg/l) were tested. The detection limits calculated were similar to the Maximum Residue Limits when a bioassay using B. megaterium ATCC 9885 spores (2.8×10(8)spores/ml) and chloramphenicol (2000μg/l) was utilized. This bioassay detects 105μg/l of chlortetracycline, 100μg/l of oxytetracycline and 134μg/l of tetracycline in 5h. Therefore, this method is suitable to be incorporated into a microbiological multi-residue system for the identification of tetracyclines in milk. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Predicting subject-driven actions and sensory experience in a virtual world with relevance vector machine regression of fMRI data.

    Science.gov (United States)

    Valente, Giancarlo; De Martino, Federico; Esposito, Fabrizio; Goebel, Rainer; Formisano, Elia

    2011-05-15

    In this work we illustrate the approach of the Maastricht Brain Imaging Center to the PBAIC 2007 competition, where participants had to predict, based on fMRI measurements of brain activity, subject driven actions and sensory experience in a virtual world. After standard pre-processing (slice scan time correction, motion correction), we generated rating predictions based on linear Relevance Vector Machine (RVM) learning from all brain voxels. Spatial and temporal filtering of the time series was optimized rating by rating. For some of the ratings (e.g. Instructions, Hits, Faces, Velocity), linear RVM regression was accurate and very consistent within and between subjects. For other ratings (e.g. Arousal, Valence) results were less satisfactory. Our approach ranked overall second. To investigate the role of different brain regions in ratings prediction we generated predictive maps, i.e. maps of the weighted contribution of each voxel to the predicted rating. These maps generally included (but were not limited to) "specialized" regions which are consistent with results from conventional neuroimaging studies and known functional neuroanatomy. In conclusion, Sparse Bayesian Learning models, such as RVM, appear to be a valuable approach to the multivariate regression of fMRI time series. The implementation of the Automatic Relevance Determination criterion is particularly suitable and provides a good generalization, despite the limited number of samples which is typically available in fMRI. Predictive maps allow disclosing multi-voxel patterns of brain activity that predict perceptual and behavioral subjective experience. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Insight into synergetic mechanisms of tetracycline and the selective serotonin reuptake inhibitor, sertraline, in a tetracycline-resistant strain of Escherichia coli

    DEFF Research Database (Denmark)

    Li, Lili; Kromann, Sofie; Olsen, John Elmerdahl

    2017-01-01

    and tetracycline in an E. coli strain with TetA-mediated tetracycline resistance (E. coli APEC-O2) was assessed by the MIC and checkerboard assays. The global transcriptome of E. coli APEC-O2 exposed to MIC concentrations of sertraline and/or tetracycline was analyzed to elucidate the interaction mechanism between...... sertraline and tetracycline. The fractional inhibitory concentration index for tetracycline and sertraline in E. coli APEC-O2 was 0.5. In addition, in the presence of MIC of sertraline, the sensitivity of E. coli APEC-O2 to tetracycline could be restored according to clinical standards (from 64 to 4 mg l â...... '1). RNA data suggest changes in respiration that is likely to decrease intracellular pH and thereby the proton-motive force, which provides the energy for the tetracycline efflux pump. Furthermore, sertraline and tetracycline may induce a change from oxidation to fermentation in the E.coli, which...

  17. Trueperella pyogenes isolated from dairy cows with endometritis in Inner Mongolia, China: Tetracycline susceptibility and tetracycline-resistance gene distribution.

    Science.gov (United States)

    Zhang, Dexian; Zhao, Jingcui; Wang, Qiuxia; Liu, Yaochuan; Tian, Chunlian; Zhao, Yujun; Yu, Lihui; Liu, Mingchun

    2017-04-01

    Trueperella pyogenes plays a crucial role in endometritis pathogenesis and is also associated with many infections, including metritis, mastitis, arthritis and liver abscessation, in many domestic animals. In this study, we investigated the prevalence of tetracycline resistance in T. pyogenes isolated from dairy cows with endometritis in Inner Mongolia, China, and we assessed tetracycline-resistance gene distribution among the isolates. Our results indicated that 68.7% and 62.5% of the isolates were resistant to tetracycline and doxycycline, respectively, and the rate of resistance to metacycline was 18.8%. The tetracycline resistance gene tetK was present in all isolates (n = 32), whereas the tetM gene was identified in 12.5% and 9.4% of the isolates, in the chromosome and plasmid, respectively. Strains carrying tetW were also common in the chromosome and plasmid, with abundances of 53.1% and 46.9%, respectively. However, tetO and otrA were absent in all isolates. The resistance phenotype analysis indicated that 6.3% of strains were susceptible to all tetracyclines, while 3.1% showed resistance to all tetracyclines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Assessment of the mode of action underlying development of rodent small intestinal tumors following oral exposure to hexavalent chromium and relevance to humans

    Science.gov (United States)

    Proctor, Deborah M.; Suh, Mina; Haws, Laurie C.; Kirman, Christopher R.; Harris, Mark A.

    2013-01-01

    Chronic exposure to high concentrations of hexavalent chromium (Cr(VI)) in drinking water causes intestinal adenomas and carcinomas in mice, but not in rats. Cr(VI) causes damage to intestinal villi and crypt hyperplasia in mice after only one week of exposure. After two years of exposure, intestinal damage and crypt hyperplasia are evident in mice (but not rats), as are intestinal tumors. Although Cr(VI) has genotoxic properties, these findings suggest that intestinal tumors in mice arise as a result of chronic mucosal injury. To better understand the mode of action (MOA) of Cr(VI) in the intestine, a 90-day drinking water study was conducted to collect histological, biochemical, toxicogenomic and pharmacokinetic data in intestinal tissues. Using MOA analyses and human relevance frameworks proposed by national and international regulatory agencies, the weight of evidence supports a cytotoxic MOA with the following key events: (a) absorption of Cr(VI) from the intestinal lumen, (b) toxicity to intestinal villi, (c) crypt regenerative hyperplasia and (d) clonal expansion of mutations within the crypt stem cells, resulting in late onset tumorigenesis. This article summarizes the data supporting each key event in the MOA, as well as data that argue against a mutagenic MOA for Cr(VI)-induced intestinal tumors. PMID:23445218

  19. Tetracycline inducible gene manipulation in serotonergic neurons.

    Directory of Open Access Journals (Sweden)

    Tillmann Weber

    Full Text Available The serotonergic (5-HT neuronal system has important and diverse physiological functions throughout development and adulthood. Its dysregulation during development or later in adulthood has been implicated in many neuropsychiatric disorders. Transgenic animal models designed to study the contribution of serotonergic susceptibility genes to a pathological phenotype should ideally allow to study candidate gene overexpression or gene knockout selectively in serotonergic neurons at any desired time during life. For this purpose, conditional expression systems such as the tet-system are preferable. Here, we generated a transactivator (tTA mouse line (TPH2-tTA that allows temporal and spatial control of tetracycline (Ptet controlled transgene expression as well as gene deletion in 5-HT neurons. The tTA cDNA was inserted into a 196 kb PAC containing a genomic mouse Tph2 fragment (177 kb by homologous recombination in E. coli. For functional analysis of Ptet-controlled transgene expression, TPH2-tTA mice were crossed to a Ptet-regulated lacZ reporter line (Ptet-nLacZ. In adult double-transgenic TPH2-tTA/Ptet-nLacZ mice, TPH2-tTA founder line L62-20 showed strong serotonergic β-galactosidase expression which could be completely suppressed with doxycycline (Dox. Furthermore, Ptet-regulated gene expression could be reversibly activated or inactivated when Dox was either withdrawn or added to the system. For functional analysis of Ptet-controlled, Cre-mediated gene deletion, TPH2-tTA mice (L62-20 were crossed to double transgenic Ptet-Cre/R26R reporter mice to generate TPH2-tTA/Ptet-Cre/R26R mice. Without Dox, 5-HT specific recombination started at E12.5. With permanent Dox administration, Ptet-controlled Cre-mediated recombination was absent. Dox withdrawal either postnatally or during adulthood induced efficient recombination in serotonergic neurons of all raphe nuclei, respectively. In the enteric nervous system, recombination could not be detected. We

  20. Relation between tetR and tetA expression in tetracycline resistant Escherichia coli

    DEFF Research Database (Denmark)

    Møller, Thea S. B.; Overgaard, Martin; Nielsen, Søren S.

    2016-01-01

    Background: Tetracyclines are among the most used antibiotics in livestock worldwide. Resistance is widely disseminated in Escherichia coli, where it is generally mediated by tetracycline efflux pumps, such as TetA. Expression of tetracycline efflux pumps is tightly controlled by the repressor Tet......R, which has been shown to be tetracycline-responsive at sub-MIC tetracycline concentrations. The objective of this study was to investigate the effects of increasing tetracycline concentrations on the growth of TetA-producing E. coli, and to determine how expression of tetA and tetR related to each other...... in different growth phases in the presence of tetracycline. Results: A tetracycline resistant E. coli strain containing tetA and tetR on the chromosome was constructed and cultured in the presence of increasing concentrations of tetracycline. Expression of tetR and tetA was measured at four time points...

  1. Effect of tetracycline residues in pig manure slurry on tetracycline-resistant bacteria and resistance gene tet(M) in soil microcosms

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Wulff, Gitte; Vaclavik, Elvira

    2006-01-01

    Effects of tetracycline residues from pig manure slurry on the prevalence of tetracycline-resistant bacteria and the tetracycline resistance gene, tet(M), were studied in soil microcosms. Four types of soil microcosms were established for a period of 152 days, supplemented with combinations of pig...... and oxytetracycline were almost stable through out the experimental period, but the tetracycline concentrations had no effect on prevalence of tetracycline-resistant bacteria. The presented microcosm approach simulated natural farmland conditions well and supported results from previous field studies. (c) 2006...

  2. Expression of 5-HT2A receptors in prefrontal cortex pyramidal neurons projecting to nucleus accumbens. Potential relevance for atypical antipsychotic action.

    Science.gov (United States)

    Mocci, Giuseppe; Jiménez-Sánchez, Laura; Adell, Albert; Cortés, Roser; Artigas, Francesc

    2014-04-01

    The prefrontal cortex (PFC) is involved in higher brain functions altered in schizophrenia. Classical antipsychotic drugs modulate information processing in cortico-limbic circuits via dopamine D2 receptor blockade in nucleus accumbens (NAc) whereas atypical antipsychotic drugs preferentially target cortical serotonin (5-HT) receptors. The brain networks involved in the therapeutic action of atypical drugs are not fully understood. Previous work indicated that medial PFC (mPFC) pyramidal neurons projecting to ventral tegmental area express 5-HT2A receptors suggesting that atypical antipsychotic drugs modulate dopaminergic activity distally, via 5-HT2A receptor (5-HT2A-R) blockade in PFC. Since the mPFC also projects heavily to NAc, we examined whether NAc-projecting pyramidal neurons also express 5-HT2A-R. Using a combination of retrograde tracing experiments and in situ hybridization we report that a substantial proportion of mPFC-NAc pyramidal neurons in rat brain express 5-HT2A-R mRNA in a layer- and area-specific manner (up to 68% in layer V of contralateral cingulate). The functional relevance of 5-HT2A-R to modulate mPFC-NAc projections was examined in dual-probe microdialysis experiments. The application of the preferential 5-HT2A-R agonist DOI into mPFC enhanced glutamate release locally (+66 ± 18%) and in NAc (+74 ± 12%) indicating that cortical 5-HT2A-R activation augments glutamatergic transmission in NAc. Since NAc integrates glutamatergic and dopaminergic inputs, blockade of 5-HT2A-R by atypical drugs may reduce cortical excitatory inputs onto GABAergic neurons of NAc, adding to dopamine D2 receptor blockade. Together with previous observations, the present results suggest that atypical antipsychotic drugs may control the activity of the mesolimbic pathway at cell body and terminal level. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Sorption and desorption of glyphosate, MCPA and tetracycline and their mixtures in soil as influenced by phosphate.

    Science.gov (United States)

    Munira, Sirajum; Farenhorst, Annemieke

    2017-12-02

    Phosphate fertilizers and herbicides such as glyphosate and MCPA are commonly applied to agricultural land, and antibiotics such as tetracycline have been detected in soils following the application of livestock manures and biosolids to agricultural land. Utilizing a range of batch equilibrium experiments, this research examined the competitive sorption interactions of these chemicals in soil. Soil samples (0-15 cm) collected from long-term experimental plots contained Olsen P concentrations in the typical (13 to 20 mg kg -1 ) and elevated (81 to 99 mg kg -1 ) range of build-up phosphate in agricultural soils. The elevated Olsen P concentrations in field soils significantly reduced glyphosate sorption up to 50%, but had no significant impact on MCPA and tetracycline sorption. Fresh phosphate additions in the laboratory, introduced to soil prior to, or at the same time with the other chemical applications, had a greater impact on reducing glyphosate sorption (up to 45%) than on reducing tetracycline (up to 13%) and MCPA (up to 8%) sorption. The impact of fresh phosphate additions on the desorption of these three chemicals was also statistically significant, but numerically very small namely glyphosate and tetracycline and 3% for MCPA. The presence of MCPA significantly reduced sorption and increased desorption of glyphosate, but only when MCPA was present at concentrations much greater than environmentally relevant and there was no phosphate added to the MCPA solution. Tetracycline addition had no significant effect on glyphosate sorption and desorption in soil. For the four chemicals studied, we conclude that when mixtures of phosphate, herbicides and antibiotics are present in soil, the greatest influence of their competitive interactions is phosphate decreasing glyphosate sorption and the presence of phosphate in solution lessens the potential impact of MCPA on glyphosate sorption. The presence of chemical mixtures in soil solution has an overall greater impact

  4. Liquid chromatographic determination of tetracycline residues in meat and fish.

    Science.gov (United States)

    Onji, Y; Uno, M; Tanigawa, K

    1984-01-01

    A simple and rapid method was developed for quantitative determination of common tetracyclines, such as oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC), in meat and fish. Tetracyclines were extracted with aqueous HCl, and then centrifuged. The supernate was applied to an Amberlite XAD-2 column, which was washed with water and eluted with methanol. The eluate was concentrated to about 0.5 mL under vacuum at 35 degrees C, and then measured by liquid chromatography and UV detection. Two analytical columns were used for confirmation. The average recoveries of OTC, TC, and CTC from meat and fish fortified at 1, 1, and 3 ppm were 82.6, 81.5, and 67.0% respectively.

  5. protective effect of tetracycline against dermal toxicity induced by Jellyfish venom.

    Directory of Open Access Journals (Sweden)

    Changkeun Kang

    Full Text Available BACKGROUND: Previously, we have reported that most, if not all, of the Scyphozoan jellyfish venoms contain multiple components of metalloproteinases, which apparently linked to the venom toxicity. Further, it is also well known that there is a positive correlation between the inflammatory reaction of dermal tissues and their tissue metalloproteinase activity. Based on these, the use of metalloproteinase inhibitors appears to be a promising therapeutic alternative for the treatment of jellyfish envenomation. METHODOLOGY AND PRINCIPAL FINDINGS: Tetracycline (a metalloproteinase inhibitor has been examined for its activity to reduce or prevent the dermal toxicity induced by Nemopilema nomurai (Scyphozoa: Rhizostomeae jellyfish venom (NnV using in vitro and in vivo models. HaCaT (human keratinocyte and NIH3T3 (mouse fibroblast incubated with NnV showed decreases in cell viability, which is associated with the inductions of metalloproteinase-2 and -9. This result suggests that the use of metalloproteinase inhibitors, such as tetracycline, may prevent the jellyfish venom-mediated local tissue damage. In vivo experiments showed that comparing with NnV-alone treatment, tetracycline pre-mixed NnV demonstrated a significantly reduced progression of dermal toxicity upon the inoculation onto rabbit skin. CONCLUSIONS/SIGNIFICANCE: It is believed that there has been no previous report on the therapeutic agent of synthetic chemical origin for the treatment of jellyfish venom-induced dermonecrosis based on understanding its mechanism of action except the use of antivenom treatment. Furthermore, the current study, for the first time, has proposed a novel mechanism-based therapeutic intervention for skin damages caused by jellyfish stings.

  6. Efficient control of gene expression by a tetracycline-dependent transactivator in single Dictyostelium discoideum cells

    NARCIS (Netherlands)

    Blaauw, M; Linskens, MHK; van Haastert, PJM

    2000-01-01

    We established a tetracycline-regulated gene expression system that tightly controls expression of genes in Dictyostelium discoideum. The control elements are contained in two plasmid vectors, one being an integrated plasmid encoding a chimeric tetracycline-controlled transcriptional activator

  7. Transfer of tetracycline resistance gene (tet ) between replicons in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-17

    Sep 17, 2008 ... to epidemics of diarrhea because some strains appear to have acquired plasmid from E. coli that code for heat labile and heat stable enterotoxins (Wang et al., 2006). Most diarrhoael infected patients in Nigeria treat diarrhea with tetracycline prior to .... surveillance of children from urban mexico. Antimicrob.

  8. Residues of tetracycline antibiotic in marketed goats and pigs in ...

    African Journals Online (AJOL)

    Antibiotics used in food animals can occur as residues in their products and constitute health risks to the consumers. 360 fresh meat samples comprising of liver, kidney and muscle tissues of goats and pigs collected from open markets in Ogun and Lagos States were analyzed for residues of tetracycline antibiotics.

  9. 21 CFR 520.2345b - Tetracycline tablets.

    Science.gov (United States)

    2010-04-01

    .... (2) Indications for use. Treatment of infections caused by organisms sensitive to tetracycline hydrochloride, such as bacterial gastroenteritis due to E. coli and urinary tract infections due to Staphylococcus spp. and E. coli. (3) Limitations. Administer orally; continue treatment until symptoms of the...

  10. 21 CFR 520.2345e - Tetracycline oral liquid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tetracycline oral liquid. 520.2345e Section 520... liquid. (a) Specifications. Each milliliter contains the equivalent of either 25 or 100 milligrams of... milligrams per milliliter liquid in dogs as in paragraph (c)(1) of this section; see No. 000009 in § 510.600...

  11. Reutilization of the expired tetracycline for lithium ion battery anode.

    Science.gov (United States)

    Hou, Hongying; Dai, Zhipeng; Liu, Xianxi; Yao, Yuan; Liao, Qishu; Yu, Chengyi; Li, Dongdong

    2018-02-24

    Waste antibiotics into the natural environment are the large challenges to the environmental protection and the human health, and the unreasonable disposal of the expired antibiotics is a major pollution source. Herein, to achieve the innocent treatment and the resource recovery, the expired tetracycline was tried to be reutilized as the electrode active material in lithium ion battery (LIB) for the first time. The micro-structure and element component of the expired tetracycline were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Furthermore, the corresponding electrochemical performances were also investigated by galvanostatic charge/discharge and cyclic voltammetry (CV). To be satisfactory, the expired-tetracycline-based electrode delivered the initial specific discharge capacity of 371.6mAh/g and the reversible specific capacity of 304.1mAh/g after 200cycles. The decent results will not only offer an effective strategy to recycle the expired tetracycline, but also shed a new light on the cyclic economy and the sustainable development. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Tetracycline residue in fresh and processed Clarias gariepinus from ...

    African Journals Online (AJOL)

    This study was conducted to determine the tetracycline residue in Clarias gariepinus from selected fish farms and markets in Ibadan. Pre-tested structured questionnaire was administered to 116 consenting farmers to obtain information on antibiotic usage amongst others in five LGAs of Oyo State. Ten fish farms and two ...

  13. Removal of Tetracycline from Synthetic Solution by Natural LECA

    Directory of Open Access Journals (Sweden)

    Mohammad Noori Sepehr

    2014-09-01

    Full Text Available Background: Antibiotic in environment can be accumulated in soil and sediment and then adversely affect the ecosystem function as well as decrease the natural degradation rate of pollutants by producing a antibiotic-resistant microorganisms. The antibiotic-resistant genes can also transfer to drinking water resources and then, leading untreatable human disease. Methods: Natural LECA was supported from rural resources and washed with deionized water for several time and then used as natural adsorbent. The adsorbents were characterized with a scanning electron microscope (SEM, Fourier Transform Infrared spectroscopy (FTIR, X-ray fluorescence spectroscopy (XRF and X ray diffract meter (XRD. All experiments were conducted in a batch reactor. Various parameters such as initial adsorbent mass (2, 4, 6, 8 and 10 g/L, initial antibiotic concentration (50, 100, 150 and 200 mg/L, initial solution pH (3, 5, 7, 9, and 11 and contact time (1-210 min were investigated. Results: The Results of present work showed the high removal efficiency of the adsorbent for adsorption of Tetracycline from aqueous solution. Higher removal efficiency was observed for Tetracycline at pH 3, 180 min contact time, 10 g/L of adsorbent dose and 200 mg/L of initial antibiotic concentration. In optimum condition, up to 49% of tetracycline was removed. Conclusion: Overall, the results of the present work well demonstrated that natural LECA as an inexpensive adsorbent could remove effectively the antibiotics namely Tetracycline from aqueous solution.

  14. Fast simultaneous electrochemical detection of tetracycline and fluoxetine in water

    NARCIS (Netherlands)

    Ardelean, Magdalena; Pode, Rodica; Schoonman, J.; Pop, Aniela; Manea, Florica

    2017-01-01

    The electrochemical methods-based protocol for simultaneous detection of tetracycline (TC) from antibiotics class and fluoxetine (FXT) from anti-depressive pharmaceuticals class, which belongs to emerging pollutants from water, was developed in this study using carbon nanofiber-epoxy composite

  15. 21 CFR 520.2345g - Tetracycline hydrochloride and sodium novobiocin tablets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tetracycline hydrochloride and sodium novobiocin... § 520.2345g Tetracycline hydrochloride and sodium novobiocin tablets. (a) Specifications. Each tablet contains the equivalent of 60 milligrams of tetracycline hydrochloride and 60 milligrams of novobiocin, or...

  16. 21 CFR 520.2345h - Tetracycline hydrochloride, sodium novobiocin, and prednisolone tablets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tetracycline hydrochloride, sodium novobiocin, and... ANIMAL DRUGS § 520.2345h Tetracycline hydrochloride, sodium novobiocin, and prednisolone tablets. (a) Specifications. Each tablet contains the equivalent of 60 milligrams of tetracycline hydrochloride, 60 milligrams...

  17. [Hygienic substantiation of the permissible levels for tetracycline-group antibiotics in food].

    Science.gov (United States)

    Onishchenko, G G; Sheveleva, S A; Khotimchenko, S A

    2012-01-01

    For the purpose of justification of the hygienic standard for tetracycline-group antibiotics in the food production established in the Russian Federation at more rigid level, than maximum and admissible levels (MAL) of the Codex Alimentarius Commission, the analysis of data of literature on negative nature of impact of low concentration of these antibiotics on an organism and the environmental conditions and risk for health has been performed. Inadequacy of the accepted admissible daily dose (ADD) accepted by The Joint FAO/WHO Expert Committee on Food Additives (JECFA) on action on selection of resistant E. coli in intestines, for the wide contingent of consumers in connection with ignoring of obvious factors of uncertainty (gastrointestinal dysbiosis, age and individual variations in the microbiota of people synergy with other antibiotics residues in food and indirect impact on an organism through microflora from the natural habitat (resistance genes, modified causative organisms with altered properties).. By the analysis of information received with the use of modern molecular and genetic methods, the role of Subinhibitory concentrations (sub-MICs) of tetracyclines as biologically active substances, signaling molecules which, without causing obvious negative consequences in a macroorganism, serve as a major factor of regulation of a transcription in microorganisms and activation of a horizontal gene transfer coding resistance, transferred on conjugative transposons of Tn916-Tn1545 family. Reasonable scientific data on a dominating contribution of minor levels of tetracyclines in globalization in the nature of the most adverse transmissive type of the antibiotic resistance interfaced to formation new bacterial pathotypes, as consequences of irrationally high scales of application in agriculture and strengthened impact on microbic ecosystems of live organisms and objects of habitat are presented. For minimization of this mediated risk for health the need of

  18. Bioavailability of Soil-Sorbed Tetracycline to Escherichia coli under Unsaturated Conditions.

    Science.gov (United States)

    Chen, Zeyou; Zhang, Wei; Wang, Gang; Zhang, Yingjie; Gao, Yanzheng; Boyd, Stephen A; Teppen, Brian J; Tiedje, James M; Zhu, Dongqiang; Li, Hui

    2017-06-06

    Increasing concentrations of anthropogenic antibiotics in soils are partly responsible for the proliferation of bacterial antibiotic resistance. However, little is known about how soil-sorbed antibiotics exert selective pressure on bacteria in unsaturated soils. This study investigated the bioavailability of tetracycline sorbed on three soils (Webster clay loam, Capac sandy clay loam, and Oshtemo loamy sand) to a fluorescent Escherichia coli bioreporter under unsaturated conditions using agar diffusion assay, microscopic visualization, and model simulation. Tetracycline sorbed on the soils could be desorbed and become bioavailable to the E. coli cells at matric water potentials of -2.95 to -13.75 kPa. Bright fluorescent rings were formed around the tetracycline-loaded soils on the unsaturated agar surfaces, likely due to radial diffusion of tetracycline desorbed from the soils, tetracycline uptake by the E. coli cells, and its inhibition on E. coli growth, which was supported by the model simulation. The bioavailability of soil-sorbed tetracycline was much higher for the Oshtemo soil, probably due to faster diffusion of tetracycline in coarse-textured soils. Decreased bioavailability of soil-sorbed tetracycline at lower soil water potential likely resulted from reduced tetracycline diffusion in soil pore water at smaller matric potential and/or suppressed tetracycline uptake by E. coli at lower osmotic potential. Therefore, soil-sorbed tetracycline could still exert selective pressure on the exposed bacteria, which was influenced by soil physical processes controlled by soil texture and soil water potential.

  19. Solvent extraction studies using tetracycline as complexing agent Pt. 9

    International Nuclear Information System (INIS)

    Saiki, M.; Lima, F.W.

    1978-01-01

    Separation of scandium from zinc is acomplished by solvent extraction technique using benzyl alcohol-tetracycline solution as organic phase. The radioisotopes Sc-46 and Zn-65 were obtained by irradiation of powdered metallic zinc and of Sc 2 O 3 . Extraction took place at 25 +- 0.5 deg C and the separatory funnels were mechanically shaken for 30 min at that temperature. Concentration of NaClO 4 in the aqueous phase was equal to 0.10 M and of tetracycline in the organic phase, 0.01 M. Activities of Sc-46 and Zn-65 were measured in a well type NaI(Tl) detector coupled to a single channel analyser. (T.I.)

  20. Tetracycline-induced renal failure after dental treatment.

    Science.gov (United States)

    Miller, Craig S; McGarity, Gary J

    2009-01-01

    Tetracyclines are broad-spectrum antibiotics used by dental practitioners in the treatment of periodontal disease. They generally are safe in adults. However, caution is advised in patients who have pre-existing kidney disease. A 42-year-old woman with polycystic kidney disease received a prescription for tetracycline (250 milligrams, four times daily) after undergoing tooth extractions. She developed nausea, vomiting and diarrhea within days and end-stage renal disease within two weeks of taking the antibiotic. Hemodialysis was required to stabilize the patient's condition. Use of the Naranjo nomogram demonstrated an association between the two events. This case illustrates the importance of obtaining a thorough medical history and understanding potential adverse drug effects before prescribing a common antibiotic.

  1. Determination of the stability constants of uranium-tetracycline complexes

    International Nuclear Information System (INIS)

    Tarenzi, L.R.; Saiki, M.

    1983-01-01

    Stability constants of complexes formed with tetracycline (TC) and uranium have been determined by solvent extraction technique. The site on the tetracycline molecule at which uranyl ion may be bound has been studied by means of potentiometric titration and spectrophotometric techniques. The complex species with 1:1 and 1:2 for UO 2 : TC ratio have been identified by conductometric titration. Solvent extraction studies have also shown that the complexes are mononuclear of the type UO 2 (TC) sub (n) (n=1,2) and that no hidroxocomplexes or negatively charged complexes have been formed. Stability constant values have been calculated by numerical weighted least square method and by graphical methods of two parameters, of the average number of ligands and of the limiting value. (Author) [pt

  2. Liquid chromatographic determination of tetracycline residues in animal feeds.

    Science.gov (United States)

    Martinez, E E; Shimoda, W

    1988-01-01

    A liquid chromatographic method for the multiresidue determination of tetracyclines (TCs) in feeds is described. The levels of quantitation were 10 ppm each for tetracycline-HCl (TC), oxytetracycline (OTC), and chlortetracycline-HCl (CTC); the detection limit was 40 ppb for each. The calibration curves were linear between 2.5 and 100 ppm. The procedure involved double extraction with pH 2.0 and pH 4.5 McIlvain buffers, cleanup on a Sephadex LH-20 column, separation on a Nova-Pak C18 column, and detection at 370 nm. Recoveries of 10 micrograms/g of each TC in multiresidue feed samples ranged from 55.8 to 75.5% for OTC, 71.6 to 100% for TC, and 22.4 to 60.6% for CTC. The identities of the TCs were confirmed by thin layer chromatography.

  3. A new three-phase heterocrystal catalysts and their superior treatment efficiency for tetracycline

    Science.gov (United States)

    Wang, Feng-Rui; Sun, Hui-Ping; Wang, Yan; Liu, Jin-Ku; Fang, Yi; Wang, Jian-Dong

    An easy recyclable and interesting Ag3PO4@Pt@TiO2 (APTP) three-phase heterocrystal chains were self-assembled by the cohesive action and chemical construction of polyvinylpyrrolidone (PVP). We found that a new electron-hole transmission path has been built via the rematch of the band structure of Ag3PO4, Pt and TiO2 which extends the light absorption and promoted the electron-hole separation to treat the antibiotic residues in the water. Based on the thorough investigations, a new catalytic material was provided for antibiotics degradation. The catalytic activity of APTP toward the degradation of tetracycline solution was enhanced by 166.67% and the stability increased remarkably compared with pure Ag3PO4 through the integration of different functional components.

  4. DNA alterations photosensitized by tetracycline and some of its derivatives

    International Nuclear Information System (INIS)

    Piette, J.; Decuyper, J.; Van de Vorst, A.

    1986-01-01

    Bacteriophage M13 mp10 DNA were irradiated with near-UV light in the presence of tetracycline derivatives and primed with synthetic oligonucleotide to be used for DNA synthesis using Escherichia coli DNA polymerase. Chain terminations were observed by denaturing polyacrylamide gel electrophoresis and mapped precisely. All the synthesis stops occurred before or at the level of guanine residues, showing that the photoreaction mediated by tetracycline derivatives led to a preferential alteration of guanine residues. These lesions were demonstrated to be induced in DNA through a pathway involving singlet oxygen. Tetracycline derivatives also photoinduced the breakage of the DNA sugar-phosphate backbone monitored by the conversion of supercoiled phi X174 DNA to a relaxed form. This lesion was shown to be initiated by hydroxyl radicals. The production of this free radical has been confirmed by electron paramagnetic resonance (EPR) spin trapping experiments using 5,5-dimethyl-1-pyrroline-N-oxide as spin trap. In addition to the EPR signal due to OH radicals trapping another unassigned signal has been detected

  5. Dietary exposure to tetracycline residues through milk consumption in Iran.

    Science.gov (United States)

    Aalipour, Fathollah; Mirlohi, Maryam; Jalali, Mohammad; Azadbakht, Leila

    2015-01-01

    The abundant use of tetracycline antibiotics in veterinary medicine may result in the presence of their residues in milk at unsafe concentrations that can adversely affect public health. The aim of the current study was to evaluate the risk of tetracycline residue (TET) intake via milk consumption amongst different age groups of human consumers in Iran. To quantify the drug residues, HPLC analysis was performed under isocratic conditions using UV detection at 355 nm. Milk consumption patterns were determined using a recent nutrition survey in Iran. The average concentration of total TETs in milk was determined to be 252.41 μg/kg, which is approximately 2.5 times greater than the maximum residue limit (MRL) set by codex. Of the four different tetracycline antibiotics analyzed, oxytetracyclin had the highest share (86 %) of the determined contamination. Daily exposure to TETs through milk using an average data on milk consumption was estimated to range from 58-62 μg. but, distribution based exposure to TETs in milk appeared as 0-99.3 μg per day. Risk characterization of dietary exposure to TETs residue via milk intake in different age groups showed that considering the standard dietary recommendation that advices on two servings of milk per day (480 ml), consumers may receive 7-30 % of the determined ADI via bovine milk consumption.

  6. Tetracycline Reduces Kidney Damage Induced by Loxosceles Spider Venom

    Directory of Open Access Journals (Sweden)

    Cinthya Kimori Okamoto

    2017-03-01

    Full Text Available Envenomation by Loxosceles spider can result in two clinical manifestations: cutaneous and systemic loxoscelism, the latter of which includes renal failure. Although incidence of renal failure is low, it is the main cause of death, occurring mainly in children. The sphingomyelinase D (SMase D is the main component in Loxosceles spider venom responsible for local and systemic manifestations. This study aimed to investigate the toxicity of L. intermedia venom and SMase D on kidney cells, using both In vitro and in vivo models, and the possible involvement of endogenous metalloproteinases (MMP. Results demonstrated that venom and SMase D are able to cause death of human kidney cells by apoptosis, concomitant with activation and secretion of extracellular matrix metalloproteases, MMP-2 and MMP-9. Furthermore, cell death and MMP synthesis and secretion can be prevented by tetracycline. In a mouse model of systemic loxoscelism, Loxosceles venom-induced kidney failure was observed, which was abrogated by administration of tetracycline. These results indicate that MMPs may play an important role in Loxosceles venom-induced kidney injury and that tetracycline administration may be useful in the treatment of human systemic loxoscelism.

  7. Use of tetracycline as complexing agent in radiochemical separations

    International Nuclear Information System (INIS)

    Saiki, M.; Nastasi, M.J.C.; Lima, F.W.

    1981-01-01

    The use of the antibiotic agent tetracycline (TC) for analytical purposes in solvent extraction procedures is presented. Individual extraction curves for the lanthanides, zinc, scandium, uranium, thorium, neptunium and protactinium were obtained. Separation of those elements from one another, and of uranium from selenium, bromine, antimony, barium, tantalum and tungsten was carried out. In all cases benzyl alcohol was the diluent used to dissolve tetracycline hydrochloride. Sodium chloride was used as supporting electrolyte for the lanthanide separations and sodium perchlorate for the other elements mentioned. Stability or formation constants for the lanthanide complexes as well as for thorium complex with tetracycline were determined by using the methods of average number of ligands, the limiting value (for thorium), the two parameters and the weighted least squares. For the lanthanides, the stability constants of the complexes Ln(TC) 3 go from 9.35+-0.22 for lanthanum up to 10.84+-0.11 for lutetium. For the Th(TC) 4 complex the formation constant is equal to 24.6+-0.3. Radioisotopes of the respective elements were used as tracers for the determinations. (author)

  8. Degradation patterns of tetracycline antibiotics in reverse micelles and water.

    Science.gov (United States)

    Sah, Hongkee

    2006-11-01

    The objective of this study was to determine the chemical stability of tetracycline and oxytetracycline hydro-chlorides in reverse micelles. Their reverse micellar solutions were prepared using cetyltrimethylammonium bromide, water and ethyl formate. The aqueous solutions of the tetracycline antibiotics were also prepared for comparison. The reverse micellar and aqueous solutions were stored at 37 degrees C. Samples were analyzed by high performance liquid chromatography. When evaluation was performed on an aqueous tetracycline HCl solution, its half-life was estimated to be 329 h. Its chemical stability was not improved after being dissolved in the reverse micelles, and a similar half-life of 330 h was observed. However, there were noticeable differences between the two systems in terms of degradation kinetics and degradation byproducts. On the other hand, oxytetracycline HCl was unstable in water so that its half-life was only 34 h. Very interestingly, pronounced improvement in stability was attained with the reverse micellar system: upon dissolving in the reverse micelles, its half-life was increased to 2402 h. There were also marked differences in degradation patterns and mechanisms of oxytetracycline HCl in water and the reverse micelles. Our study indicates that the reverse micellar system has potential applications in solubilizing and stabilizing oxytetracycline HCl, thereby contributing to the development of its dosage forms. Copyright (c) 2006 John Wiley & Sons, Ltd.

  9. Tetracycline-impregnated enamel and dentin: duration of antimicrobial capacity.

    Science.gov (United States)

    Bjorvatn, K; Skaug, N; Selvig, K A

    1985-06-01

    The present study was done in order to examine the durability of the tetracycline-induced antimicrobial capacity, and also to assess the reproducibility of the bacterial growth-inhibitory assay used. Standardized enamel and dentin specimens were impregnated in aqueous solutions of tetracycline HCl, oxytetracycline HCl or doxycycline HCl, rinsed in water, and stored dry for 200 days. Another series of specimens was impregnated in solutions of doxycycline HCl and then rinsed in tap water for varying periods up to 35 days. In addition, drug-impregnated specimens were used for reproducibility tests without storage or prolonged rinsing. Impregnated specimens were tested for antimicrobial capacity on agar plates seeded with S. sanguis. After 24 h aerobic incubation in 10% CO2 atmosphere, the plates were inspected and the diameter of the bacterial growth inhibition zones measured. The drug-impregnated enamel and dentin specimens consistently demonstrated growth-inhibitory capacity. The results of the reproducibility tests showed moderate intrasample and day-to-day variation. Two hundred days of dry storage or 35 days soaking in water reduced, but did not eliminate, the bacterial growth-inhibitory capacity of the impregnated dental specimens. The results show that a short-term exposure of dental hard tissues to tetracyclines may result in a long-lasting antibacterial capacity.

  10. Oxidative actions of hydrogen peroxide in human gingival and oral periosteal fibroblasts: Responses to glutathione and nicotine, relevant to healing in a redox environment

    OpenAIRE

    Federico Tinti; Mena Soory

    2014-01-01

    Background: This study aims to validate pro-oxidant actions of nicotine (N), using hydrogen peroxide (H2O2) and the antioxidant glutathione (G) in an in vitro model of human gingival fibroblasts (HGF) and human oral periosteal fibroblasts (HPF); radiolabelled androgens are used as biomarkers of redox status. Oxidative stress is an important mediator of inflammatory repair. The androgen metabolite 5α-dihydrotestosterone (DHT) is an effective biomarker of oxidative stress and healing. Method...

  11. Being and «genera» of being in Ancient Stoicism. A relevant ontological distinction applied to ethics and action theory

    Directory of Open Access Journals (Sweden)

    Marcelo D. Boeri

    2014-11-01

    Full Text Available This paper is focused on the Stoic doctrine of genera of being and the way in which such a doctrine appears to function in ethics and in action theory. In section I, the soul-body problem in Aristotle is briefly discussed; I argue that, in order to overcome the difficulties of the relation between soul and body in a psychology maintaining that the soul is an immaterial entity, the Stoics were willing to endorse a physicalist psychology. Second, I offer an account of the Stoic ontology and attempt to show the role of each genera of being in such an ontology. In section III I return to the Stoic genera of being but concentrating on the suitable connections to make more persuasive the thesis that the Stoic genera of being should play a role in ethics and in action theory. Finally, in section IV I present some concluding remarks.

  12. Rapid corticosteroid actions on synaptic plasticity in the mouse basolateral amygdala: relevance of recent stress history and β-adrenergic signaling.

    Science.gov (United States)

    Sarabdjitsingh, R A; Joëls, M

    2014-07-01

    The rodent stress hormone corticosterone rapidly enhances long-term potentiation in the CA1 hippocampal area, but leads to a suppression when acting in a more delayed fashion. Both actions are thought to contribute to stress effects on emotional memory. Emotional memory formation also involves the basolateral amygdala, an important target area for corticosteroid actions. We here (1) investigated the rapid effects of corticosterone on amygdalar synaptic potentiation, (2) determined to what extent these effects depend on the mouse's recent stress history or (3) on prior β-adrenoceptor activation; earlier studies at the single cell level showed that especially a recent history of stress changes the responsiveness of basolateral amygdala neurons to corticosterone. We report that, unlike the hippocampus, stress enhances amygdalar synaptic potentiation in a slow manner. In vitro exposure to 100 nM corticosterone quickly decreases synaptic potentiation, and causes only transient potentiation in tissue from stressed mice. This transient type of potentiation is also seen when β-adrenoceptors are blocked during stress and this is further exacerbated by subsequent in vitro administered corticosterone. We conclude that stress and corticosterone change synaptic potentiation in the basolateral amygdala in a manner opposite to that seen in the hippocampus and that renewed exposure to corticosterone only allows induction of non-persistent forms of synaptic potentiation. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. A Reformed perspective on the concept of the ‘common good’ and its relevance for social action in South Africa today

    Directory of Open Access Journals (Sweden)

    Jakobus M. Vorster

    2016-05-01

    Full Text Available This article investigates the idea of the ‘common good’ from a Classic Reformed perspective and the possibilities raised by a fresh approach to the concept for social action by civil society in South Africa today. The central theoretical argument of this article is that the new interest in the concept of natural law, as became evident in modern-day moral reflection in the Classic Reformed moral teaching, can indeed contribute to a new positive assessment of the concept common good and can provide a valuable framework for the foundation of reformed social action in cooperation with civil society in South Africa today. Firstly, the concept is discussed within the framework of the reformed idea of ‘natural law’ and the argument concludes with the finding that the concept can be accommodated in Reformed Theology. Secondly, a case is made for the cooperation between churches, other religious institutions and the broader civil society to cooperate on the basis of the common good and global ethics to address three areas of serious concern in the South African society. These are the promotion of the idea of human dignity within the social sphere with special reference to racism, xenophobia and sexism as well as the development of family life and family values, and the advancement of the idea of neighbourliness as a core ingredient of social healing and reconciliation.

  14. Subacute neuronopathy in a young man: a possible association with tetracycline treatment

    Directory of Open Access Journals (Sweden)

    Magnus Vrethem

    2011-11-01

    Full Text Available A young man with subacute neuronopathy following tetracycline treatment is described. The symptoms started as a sensory dorsal root affection but by time also involved motor nerves. He developed a severe sensory ataxia with pseudoathetotic movements. Other possible aetiologies were scrutinized and excluded. Tetracycline induced neuronopathy is hitherto not reported in the literature. We propose a possible association between treatment with tetracycline and the development of sensory neuronopathy in this patient.

  15. Resistance to tetracycline and multidrug resistance in resident E. coli, risk for the public health

    OpenAIRE

    Urumova, Valentina

    2015-01-01

    The most important resistant profiles in indicator E. coli isolated from swine are resistance to sulfonamides/tetracycline, ampicillin/streptomycin/sulfonamides/tetracycline. The selection pressure of tetracycline, beta-lactams and streptomycin in farm animals especially in pig farms induced co-selection to other chemotherapeutic agents and horizontal transfer of resistance is a serious risk for the dissemination of resistant genes in E. coli isolated from farm animals. The common genes li...

  16. Long-term actions of interleukin-1beta on delay and tonic firing neurons in rat superficial dorsal horn and their relevance to central sensitization.

    Science.gov (United States)

    Gustafson-Vickers, Sabrina L; Lu, Van B; Lai, Aaron Y; Todd, Kathryn G; Ballanyi, Klaus; Smith, Peter A

    2008-12-17

    Cytokines such as interleukin 1beta (IL-1beta) have been implicated in the development of central sensitization that is characteristic of neuropathic pain. To examine its long-term effect on nociceptive processing, defined medium organotypic cultures of rat spinal cord were exposed to 100 pM IL-1beta for 6-8 d. Interleukin effects in the dorsal horn were examined by whole-cell patch-clamp recording and Ca(2+) imaging techniques. Examination of the cultures with confocal Fluo-4 AM imaging showed that IL-1beta increased the change in intracellular Ca(2+) produced by exposure to 35-50 mM K+. This is consistent with a modest increase in overall dorsal horn excitability. Despite this, IL-1beta did not have a direct effect on rheobase or resting membrane potential nor did it selectively destroy any specific neuronal population. All effects were instead confined to changes in synaptic transmission. A variety of pre- and postsynaptic actions of IL-1beta were seen in five different electrophysiologically-defined neuronal phenotypes. In putative excitatory 'delay' neurons, cytokine treatment increased the amplitude of spontaneous EPSC's (sEPSC) and decreased the frequency of spontaneous IPSC's (sIPSC). These effects would be expected to increase dorsal horn excitability and to facilitate the transfer of nociceptive information. However, other actions of IL-1beta included disinhibition of putative inhibitory 'tonic' neurons and an increase in the amplitude of sIPSC's in 'delay' neurons. Since spinal microglial activation peaks between 3 and 7 days after the initiation of chronic peripheral nerve injury and these cells release IL-1beta at this time, our findings define some of the neurophysiological mechanisms whereby nerve-injury induced release of IL-1beta may contribute to the central sensitization associated with chronic neuropathic pain.

  17. Long-term actions of interleukin-1β on delay and tonic firing neurons in rat superficial dorsal horn and their relevance to central sensitization

    Directory of Open Access Journals (Sweden)

    Ballanyi Klaus

    2008-12-01

    Full Text Available Abstract Background Cytokines such as interleukin 1β (IL-1β have been implicated in the development of central sensitization that is characteristic of neuropathic pain. To examine its long-term effect on nociceptive processing, defined medium organotypic cultures of rat spinal cord were exposed to 100 pM IL-1β for 6–8 d. Interleukin effects in the dorsal horn were examined by whole-cell patch-clamp recording and Ca2+ imaging techniques. Results Examination of the cultures with confocal Fluo-4 AM imaging showed that IL-1β increased the change in intracellular Ca2+ produced by exposure to 35–50 mM K+. This is consistent with a modest increase in overall dorsal horn excitability. Despite this, IL-1β did not have a direct effect on rheobase or resting membrane potential nor did it selectively destroy any specific neuronal population. All effects were instead confined to changes in synaptic transmission. A variety of pre- and postsynaptic actions of IL-1β were seen in five different electrophysiologically-defined neuronal phenotypes. In putative excitatory 'delay' neurons, cytokine treatment increased the amplitude of spontaneous EPSC's (sEPSC and decreased the frequency of spontaneous IPSC's (sIPSC. These effects would be expected to increase dorsal horn excitability and to facilitate the transfer of nociceptive information. However, other actions of IL-1β included disinhibition of putative inhibitory 'tonic' neurons and an increase in the amplitude of sIPSC's in 'delay' neurons. Conclusion Since spinal microglial activation peaks between 3 and 7 days after the initiation of chronic peripheral nerve injury and these cells release IL-1β at this time, our findings define some of the neurophysiological mechanisms whereby nerve-injury induced release of IL-1β may contribute to the central sensitization associated with chronic neuropathic pain.

  18. Culturally Relevant Cyberbullying Prevention

    OpenAIRE

    Phillips, Gregory John

    2017-01-01

    In this action research study, I, along with a student intervention committee of 14 members, developed a cyberbullying intervention for a large urban high school on the west coast. This high school contained a predominantly African American student population. I aimed to discover culturally relevant cyberbullying prevention strategies for African American students. The intervention committee selected video safety messages featuring African American actors as the most culturally relevant cyber...

  19. Spread of tetracycline resistance genes at a conventional dairy farm

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Jirout, Jiří; Vrchotová, Naděžda; Schmitt, H.; Elhottová, Dana

    2015-01-01

    Roč. 6, may (2015), s. 536 ISSN 1664-302X R&D Projects: GA ČR GAP504/10/2077; GA MŠk(CZ) EE2.3.30.0032; GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 ; RVO:60077344 Keywords : antibiotic resistance spread * animal manure * cattle intestinal microflora * chlortetracycline * dairy cattle * dairy farm * heavy metals * tetracycline resistance genes Subject RIV: EI - Biotechnology ; Bionics; EE - Microbiology, Virology (BC-A) Impact factor: 4.165, year: 2015

  20. Differential pulse polarography of some degradation products of tetracycline.

    Science.gov (United States)

    Jochsberger, T; Cutie, A J; Wang, H Y; Mary, N Y

    1982-11-01

    In an attempt to develop a more rapid, convenient, and precise method for the direct detection and analysis of the degradation products of tetracycline, a study of those products utilizing differential pulse polarography was initiated. The investigation was concentrated on the subject of the kinetics of the epimerization of anhydrotetracycline to 4-epianhydrotetracycline in acetate buffer. The reaction was followed at 25 and 50 degrees. Duplicate experiments were run at each temperature. The apparent rate constants obtained were 4.17 +/- 0.13 X 10(-1)/hr (25 degrees) and 6.97 +/- 1.00 X 10(-2)/hr (50 degrees).

  1. Transformation of tetracycline by TetX and its subsequent degradation in a heterologous host.

    Science.gov (United States)

    Ghosh, Sudeshna; LaPara, Timothy M; Sadowsky, Michael J

    2015-06-01

    TetX is a flavin-dependent monooxygenase. It has been reported to inactivate all tested tetracyclines. In this study, Escherichia coli overexpressing TetX was added to soil bacterial enrichment cultures along with varying levels of tetracycline and was found to affect community-wide tetracycline resistance levels. Soil microbial communities developed lower levels of tetracycline resistance upon exposure to 25 μg/mL of tetracycline when an E. coli expressing TetX was present (6% of cultivable bacteria were resistant to 40 μg/mL tetracycline). In contrast, in the absence of TetX activity, a similar tetracycline exposure selected for greater levels of resistant bacteria in the soil microbial community (90% of cultivable bacteria were resistant to 40 μg/mL tetracycline). We also describe new metabolites formed after tetracycline transformation by TetX and report the transient generation of redox-active metabolite(s). The results presented here are particularly pertinent in the light of the recent emergence of tet(X) in different bacterial species, including clinical isolates. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Rapid colorimetric sensing of tetracycline antibiotics with in situ growth of gold nanoparticles

    International Nuclear Information System (INIS)

    Shen, Li; Chen, Jing; Li, Na; He, Pingli; Li, Zhen

    2014-01-01

    Highlights: • Tetracyclines directly reduce aurate into gold nanoparticles. • Gold nanoparticles showed characteristic plamson absorbance at 526 nm. • Quantitative detection of tetracyclines with the colorimetric assay. • Tetracyclines spiked urine samples can be detected with the assay. - Abstract: A colorimetric assay utilizing the formation of gold nanoparticles was developed to detect tetracycline antibiotics in fluidic samples. Tetracycline antibiotics showed the capability of directly reducing aurate salts into atomic gold which form gold nanoparticles spontaneously under proper conditions. The resulted gold nanoparticles showed characteristic plasmon absorbance at 526 nm, which can be visualized by naked eyes or with a spectrophotometer. UV–vis absorbance of the resulted gold nanoparticles is correlated directly with the concentrations of tetracycline antibiotics in the solution, allowing for quantitative colorimetric detection of tetracycline antibiotics. Reaction conditions, such as pH, temperature, reaction time, and ionic strength were optimized. Sensitivity of the colorimetric assay can be enhanced by the addition of gold nanoparticle seeds, a LOD as low as 20 ng mL −1 can be achieved with the help of seed particles. The colorimetric assay showed minimum interference from ethanol, methanol, urea, glucose, and other antibiotics such as sulfonamides, amino glycosides etc. Validity of the method was also evaluated on urine samples spiked with tetracycline antibiotics. The method provides a broad spectrum detection method for rapid and sensitive detection of reductive substances such as tetracycline antibiotics in liquid and biological samples

  3. Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior.

    Science.gov (United States)

    Patrick, Rhonda P; Ames, Bruce N

    2015-06-01

    Serotonin regulates a wide variety of brain functions and behaviors. Here, we synthesize previous findings that serotonin regulates executive function, sensory gating, and social behavior and that attention deficit hyperactivity disorder, bipolar disorder, schizophrenia, and impulsive behavior all share in common defects in these functions. It has remained unclear why supplementation with omega-3 fatty acids and vitamin D improve cognitive function and behavior in these brain disorders. Here, we propose mechanisms by which serotonin synthesis, release, and function in the brain are modulated by vitamin D and the 2 marine omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Brain serotonin is synthesized from tryptophan by tryptophan hydroxylase 2, which is transcriptionally activated by vitamin D hormone. Inadequate levels of vitamin D (∼70% of the population) and omega-3 fatty acids are common, suggesting that brain serotonin synthesis is not optimal. We propose mechanisms by which EPA increases serotonin release from presynaptic neurons by reducing E2 series prostaglandins and DHA influences serotonin receptor action by increasing cell membrane fluidity in postsynaptic neurons. We propose a model whereby insufficient levels of vitamin D, EPA, or DHA, in combination with genetic factors and at key periods during development, would lead to dysfunctional serotonin activation and function and may be one underlying mechanism that contributes to neuropsychiatric disorders and depression. This model suggests that optimizing vitamin D and marine omega-3 fatty acid intake may help prevent and modulate the severity of brain dysfunction. © FASEB.

  4. Identification of the chelocardin biosynthetic gene cluster from Amycolatopsis sulphurea: a platform for producing novel tetracycline antibiotics.

    Science.gov (United States)

    Lukežič, Tadeja; Lešnik, Urška; Podgoršek, Ajda; Horvat, Jaka; Polak, Tomaž; Šala, Martin; Jenko, Branko; Raspor, Peter; Herron, Paul R; Hunter, Iain S; Petković, Hrvoje

    2013-12-01

    Tetracyclines (TCs) are medically important antibiotics from the polyketide family of natural products. Chelocardin (CHD), produced by Amycolatopsis sulphurea, is a broad-spectrum tetracyclic antibiotic with potent bacteriolytic activity against a number of Gram-positive and Gram-negative multi-resistant pathogens. CHD has an unknown mode of action that is different from TCs. It has some structural features that define it as 'atypical' and, notably, is active against tetracycline-resistant pathogens. Identification and characterization of the chelocardin biosynthetic gene cluster from A. sulphurea revealed 18 putative open reading frames including a type II polyketide synthase. Compared to typical TCs, the chd cluster contains a number of features that relate to its classification as 'atypical': an additional gene for a putative two-component cyclase/aromatase that may be responsible for the different aromatization pattern, a gene for a putative aminotransferase for C-4 with the opposite stereochemistry to TCs and a gene for a putative C-9 methylase that is a unique feature of this biosynthetic cluster within the TCs. Collectively, these enzymes deliver a molecule with different aromatization of ring C that results in an unusual planar structure of the TC backbone. This is a likely contributor to its different mode of action. In addition CHD biosynthesis is primed with acetate, unlike the TCs, which are primed with malonamate, and offers a biosynthetic engineering platform that represents a unique opportunity for efficient generation of novel tetracyclic backbones using combinatorial biosynthesis.

  5. Enterobacter agglomerans spondylodiscitis: a possible, unrecognized complication of tetracycline therapy.

    Science.gov (United States)

    Porter, P; Wray, C C

    2000-05-15

    This case report describes infection in a lumbar disc in a healthy young man with an organism of low pathogenicity. The patient was taking a prolonged course of antibiotics at the time the infection occurred. To describe this unique case of infective spondylodiscitis. To the authors' knowledge, spinal infection with Enterobacter agglomeranshas never been reported. This organism is a transient gut colonizer, and may have established itself secondary to the patient's prolonged ingestion of tetracycline for acne. This 22-year-old farmer had spontaneous lumbar back pain. Radiologic investigations showed an abnormality in the L4-L5 disc region, and together with other investigations, were suggestive of infection. The diagnosis was confirmed by surgical aspiration. Antibiotic therapy was administered, and the patient made a complete recovery. Follow-up radiographs showed a complete loss of the L4-L5 disc space with only minimal bone destruction. A unique cause of infective lumbar discitis is presented. Several features of this case are unusual. The magnetic resonance findings were not readily diagnostic. The cultured organism is usually nonpathogenic. The infection may have been secondary to prolonged tetracycline therapy.

  6. Influence of montmorillonite on antimicrobial activity of tetracycline and ciprofloxacin

    Science.gov (United States)

    Lv, Guocheng; Pearce, Cody W.; Gleason, Andrea; Liao, Libing; MacWilliams, Maria P.; Li, Zhaohui

    2013-11-01

    Antibiotics are used not only to fight infections and inhibit bacterial growth, but also as growth promotants in farm livestock. Farm runoff and other farm-linked waste have led to increased antibiotic levels present in the environment, the impact of which is not completely understood. Soil, more specifically clays, that the antibiotic contacts may alter its effectiveness against bacteria. In this study a swelling clay mineral montmorillonite was preloaded with antibiotics tetracycline and ciprofloxacin at varying concentrations and bioassays were conducted to examine whether the antibiotics still inhibited bacterial growth in the presence of montmorillonite. Escherichia coli was incubated with montmorillonite or antibiotic-adsorbed montmorillonite, and then the number of viable bacteria per mL was determined. The antimicrobial activity of tetracycline was affected in the presence of montmorillonite, as the growth of non-resistant bacteria was still found even when extremely high TC doses were used. Conversely, in the presence of montmorillonite, ciprofloxacin did inhibit E. coli bacterial growth at high concentrations. These results suggest that the effectiveness of antimicrobial agents in clayey soils depends on the amount of antibiotic substance present, and on the interactions between the antibiotic and the clays in the soil, as well.

  7. Toxicity assessment of four insecticides with different modes of action on pupae and adults of Eriopis connexa (Coleoptera: Coccinellidae), a relevant predator of the Neotropical Region.

    Science.gov (United States)

    Fogel, Marilina Noelia; Schneider, Marcela Inés; Rimoldi, Federico; Ladux, Lorena Sabrina; Desneux, Nicolas; Ronco, Alicia Estela

    2016-08-01

    Pesticides can be toxic to nontarget organisms including the natural enemies of agricultural pests, thus reducing the biodiversity of agroecosystems. The lethal and sublethal effects of four insecticides with different modes of action-pyriproxyfen, teflubenzuron, acetamiprid, and cypermethrin-were evaluated on pupae and adults of Eriopis connexa, an effective predator in horticultural crops. Pupal survival was reduced by pyriproxyfen (26 %) and cypermethrin (41 %). Malformations in adults emerged from treated pupae were observed after acetamiprid (82.7 and 100 % for 100 and 200 mg a.i./l, respectively), pyriproxyfen (48.6 %), and cypermethrin (13.3 %) treatments. A longer mean oviposition time was also observed in adults emerged from pupae treated with cypermethrin. Moreover, the latter insecticide as well as teflubenzuron did not reduce reproductive parameters, whereas females emerged from pyriproxyfen-treated pupae were not be able to lay eggs even when females showed large abdomens. Upon exposure of adults, survival was reduced to approximately 90 % by acetamiprid, but no reduction occurred with pyriproxyfen, teflubenzuron, or cypermethrin though the fecundity at fifth oviposition time of the female survivors was reduced. Pyriproxyfen decreased the hatching at all the oviposition times tested, whereas fertility was reduced in the fourth and fifth ovipositions by teflubenzuron and in the first and third ovipositions by cypermethrin. In conclusion, all four insecticides tested exhibited lethal or sublethal effects, or both, on E. connexa. The neurotoxic insecticides were more harmful than the insect-growth regulators, and pupae were more susceptible than adults. The toxicity of insecticides on the conservation of predators in agroecosystems of the Neotropical Region is discussed.

  8. Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure.

    Science.gov (United States)

    Huang, Manhong; Qi, Fangfang; Wang, Jue; Xu, Qi; Lin, Li

    2015-11-15

    Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A-C, E), was the highest among the three groups of TRGs in the different kinds of sludge. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Exercise running and tetracycline as means to enhance skeletal muscle stem cell performance after external fixation.

    Science.gov (United States)

    Shefer, G; Carmeli, E; Rauner, G; Yablonka-Reuveni, Z; Benayahu, D

    2008-04-01

    Prolonged limb immobilization, which is often the outcome of injury and illness, results in the atrophy of skeletal muscles. The basis of muscle atrophy needs to be better understood in order to allow development of effective countermeasures. The present study focused on determining whether skeletal muscle stem cells, satellite cells, are directly affected by long-term immobilization as well as on investigating the potential of pharmacological and physiological avenues to counterbalance atrophy-induced muscle deterioration. We used external fixation (EF), as a clinically relevant model, to gain insights into the relationships between muscle degenerative and regenerative conditions to the myogenic properties and abundance of bona fide satellite cells. Rats were treated with tetracycline (Tet) through the EF period, or exercise trained on a treadmill for 2 weeks after the cessation of the atrophic stimulus. EF induced muscle mass loss; declined expression of the muscle specific regulatory factors (MRFs) Myf5, MyoD, myogenin, and also of satellite cell numbers and myogenic differentiation aptitude. Tet enhanced the expression of MRFs, but did not prevent the decline of the satellite cell pool. After exercise running, however, muscle mass, satellite cell numbers (enumerated through the entire length of myofibers), and myogenic differentiation aptitude (determined by the lineal identity of clonal cultures of satellite cells) were re-gained to levels prior to EF. Together, our results point to Tet and exercise running as promising and relevant approaches for enhancing muscle recovery after atrophy. (c) 2007 Wiley-Liss, Inc.

  10. Dissemination of bacterial resistance to tetracycline antibiotics from animal husbandry to the soil.

    OpenAIRE

    HAVLÍČKOVÁ, Petra

    2011-01-01

    This bachaleor thesis is dedicated to occurence of tetracycline resistance genes in the soil environment influenced by wastes from a livestock productionanimal husbandry. In the experimental part, the transfer of tetracycline resistance genes from the excrements of a dairy cattle to the soils was studied.

  11. Rapid Detection of Bacterial Antibiotic Resistance: Preliminary Evaluation of PCR Assays Targeting Tetracycline Resistance Genes

    Science.gov (United States)

    2007-08-01

    cephalosporins and streptomycin in the 1940s was closely followed by the emergence of antibiotic resistant bacteria. The rapid increase in the number... spectrum of tetracyclines, with the exception of tet(B). Enzymatic inactivation of tetracycline: The only example described to date for inactivation of

  12. Differential Top10 promoter regulation by six tetracycline analogues in plant cells

    Science.gov (United States)

    Love, John; Allen, George C.; Gatz, Christiane; Thompson, William F.; Brown, C. S. (Principal Investigator)

    2002-01-01

    The effects of five tetracycline analogues, anhydrotetracycline, doxycycline, minocycline, oxytetracycline, and tetracycline, on Top10 promoter activity in NT1 tobacco tissue culture cells have been analysed. The concentration that repressed Top10 promoter activity, the level of transgene repression and the kinetics of transgene de-repression were determined for each analogue, and could not be predicted from in vitro binding affinity to the tetracycline repressor or from comparison with animal cells. Doxycycline had the most potent effect on the Top10 promoter and completely inhibited transgene expression at 4 nmol l(-1). Tetracycline was the most versatile of the analogues tested; tetracycline inhibited the Top10 promoter at 10 nmol l(-1) and was easily washed out to restore Top10-driven expression in 12-24 h. A study was also made of the suitability for plant research of a novel tetracycline analogue, GR33076X. In animal cells, GR33076X de-repressed Top10 promoter activity in the presence of inhibitory concentrations of anhydrotetracycline. In NT1, it is shown that GR 33076X can antagonize repression of the Top10 promoter in the presence of tetracycline, but not of anhydrotetracycline or of doxycycline. Different tetracycline analogues can therefore be used to regulate the Top10 promoter in plant cells and this property may be exploited in planning an optimum course of transgene regulation.

  13. Tetracycline adsorption on kaolinite: pH, metal cations and humic acid effects.

    Science.gov (United States)

    Zhao, Yanping; Geng, Jinju; Wang, Xiaorong; Gu, Xueyuan; Gao, Shixiang

    2011-07-01

    Contamination of environmental matrixes by human and animal wastes containing antibiotics is a growing health concern. Because tetracycline is one of the most widely-used antibiotics in the world, it is important to understand the factors that influence its mobility in soils. This study investigated the effects of pH, background electrolyte cations (Li(+), Na(+), K(+), Ca(2+) and Mg(2+)), heavy metal Cu(2+) and humic acid (HA) on tetracycline adsorption onto kaolinite. Results showed that tetracycline was greatly adsorbed by kaolinite over pH 3-6, then decreased with the increase of pH, indicating that tetracycline adsorption mainly through ion exchange of cations species and complexation of zwitterions species. In the presence of five types of cations (Li(+), Na(+), K(+), Ca(2+) and Mg(2+)), tetracycline adsorption decreased in accordance with the increasing of atomic radius and valence of metal cations, which suggested that outer-sphere complexes formed between tetracycline and kaolinite, and the existence of competitor ions lead to the decreasing adsorption. The presence of Cu(2+) greatly enhanced the adsorption probably by acting as a bridge ion between tetracycline species and the edge sites of kaolinite. HA also showed a major effect on the adsorption: at pH kaolinite and need to be considered when assessing the environmental toxicity of tetracycline.

  14. Presence of tetracycline resistance genes in ecosystems with distinct levels of human impact

    OpenAIRE

    STEHLÍKOVÁ, Zuzana

    2011-01-01

    The incidence of tetracycline resistance genes in the environments with different levels of human impact were compared in this work. The experimental part included detection of eight tetracycline resistance genes in soils from manured and non-manured farms (representing man-affected environment) and soils from national parks (representing non-affected environment).

  15. Effect of Tetracycline on Late-stage African trypanosomiasis in Rats ...

    African Journals Online (AJOL)

    Effect of Tetracycline on Late-stage African trypanosomiasis in Rats. T.O. Johnson, J.T. Ekanem. Abstract. The effect of tetracycline on late stage African trypanosomiasis was examined in an in vivo experiment using rats infected with Trypanosoma brucei brucei. Infected rats were treated on the 5th day of infection with ...

  16. The antimicrobial and antifungal efficacy of tetracycline-integrated gutta-percha

    Directory of Open Access Journals (Sweden)

    Bodrumlu Emre

    2008-01-01

    Full Text Available The purpose of this study was in vitro evaluation of the antimicrobial and antifungal efficacy of commercially available gutta-percha containing tetracycline on some potential endodontic pathogens. The test microorganisms were Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, Porphyromonas endodontalis, and Candida albicans . Tetracycline-integrated gutta-percha (TGP cones, tetracycline disc, and conventional gutta-percha cones of the same size were placed on the inoculated plates. The plates were incubated at 37°C aerobically or anaerobically. Growth inhibition zones on each plate were inspected at 24, 48, and 72 h. Tetracycline disc and TGP cones inhibited all the tested bacterial strains, however the greatest antimicrobial effect was seen on S. aureus. Tetracycline disc and TGP seemed less effective on E. faecalis and P. aeruginosa. However, all tested treatments were unable to affect C. albicans . Based on the results of this study, it seems that TGP offers an antimicrobial advantage over conventional gutta-percha.

  17. Tetracyclines Disturb Mitochondrial Function across Eukaryotic Models: A Call for Caution in Biomedical Research

    Directory of Open Access Journals (Sweden)

    Norman Moullan

    2015-03-01

    Full Text Available In recent years, tetracyclines, such as doxycycline, have become broadly used to control gene expression by virtue of the Tet-on/Tet-off systems. However, the wide range of direct effects of tetracycline use has not been fully appreciated. We show here that these antibiotics induce a mitonuclear protein imbalance through their effects on mitochondrial translation, an effect that likely reflects the evolutionary relationship between mitochondria and proteobacteria. Even at low concentrations, tetracyclines induce mitochondrial proteotoxic stress, leading to changes in nuclear gene expression and altered mitochondrial dynamics and function in commonly used cell types, as well as worms, flies, mice, and plants. Given that tetracyclines are so widely applied in research, scientists should be aware of their potentially confounding effects on experimental results. Furthermore, these results caution against extensive use of tetracyclines in livestock due to potential downstream impacts on the environment and human health.

  18. Looking for new preparations for antibacterial therapy. IV. New antimicrobial agents from the aminoglycoside, macrolide and tetracycline groups in clinical trials.

    Science.gov (United States)

    Karpiuk, Izabela; Tyski, Stefan

    2015-01-01

    This paper is the fourth in a series on the search for new antibacterial therapies, and covers new compounds belonging to the aminoglycoside, macrolide and tetracycline groups of antibiotics. The article describes eight new substances at the clinical trial stage of development. One of them is an aminoglycoside (plazomicin), four are macrolides, collectively known as ketolides (cethromycin, solithromycin, EDP-420 and EDP-788), and the remaining three are members of the tetracycline group (omadacycline, eravacycline, sarecycline). Despite the long-term and very expensive process of collecting documentation proving the efficacy of antimicrobial drugs, there is a possibility, that particular compounds find use as active ingredients of medicinal products allowing for the triumph over the clinically relevant, dangerous bacteria.

  19. Increasing tetracycline concentrations on the performance and communities of mixed microalgae-bacteria photo-bioreactors

    KAUST Repository

    Xiong, Yanghui

    2017-12-11

    This study investigated the impact of varying concentrations of tetracycline on the performance of mixed microalgae-bacteria photo-bioreactors. Photo-bioreactors were assessed for their ability to remove carbon dioxide (CO2) from the biogas of anaerobic membrane bioreactor (anMBR), and nutrients from the anaerobic effluent. The varying concentrations of tetracycline had no impact on the removal of CO2 from biogas. 29% v/v of CO2 was completely removed to generate >20% v/v of oxygen (O2) in all reactors. Removal of nutrients and biomass was not affected at low concentrations of tetracycline (≤150μg/L), but 20mg/L of tetracycline lowered the biomass generation and removal efficiencies of phosphate. Conversely, high chlorophyll a and b content was observed at 20mg/L of tetracycline. High tetracycline level had no impact on the diversity of 18S rRNA gene-based microalgal communities but adversely affected the 16S rRNA gene-based microbial communities. Specifically, both Proteobacteria and Bacteroidetes phyla decreased in relative abundance but not phylum Chloroplast. Additionally, both nitrogen-fixing (e.g. Flavobacterium, unclassified Burkholderiales and unclassified Rhizobiaceae) and denitrifying groups (e.g. Hydrogenophaga spp.) were significantly reduced in relative abundance at high tetracycline concentration. Phosphate-accumulating microorganisms, Acinetobacter spp. and Pseudomonas spp. were similarly reduced upon exposure to high tetracycline concentration. Unclassified Comamonadaceae, however, increased in relative abundance, which correlated with an increase in the abundance of tetracycline resistance genes associated with efflux pump mechanism. Overall, the findings demonstrate that antibiotic concentrations in municipal wastewaters will not significantly affect the removal of nutrients by the mixed microalgae-bacteria photo-bioreactors. However, utilizing such photo-bioreactors as a polishing step for anMBRs that treat wastewaters with high tetracycline

  20. Degradation of Tetracycline by Birnessite under Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Meng Liu

    2014-01-01

    Full Text Available The efficiency and factors affecting tetracycline (TC degradation by birnessite under microwave irradiation (MI were investigated under different initial TC concentrations, solution pH, MI time, and MI power. The crystal structure, degradation efficiency, and reaction mechanism were investigated using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, and ultraviolet-visible spectroscopy (UV-Vis. The results showed that birnessite was an excellent microwave catalyst. The maximum TC removal efficiency by birnessite was 99% under MI at 400 W for 30 min in strongly acidic media. Under MI, the surface activity of birnessite increased, resulting in the ability to accelerate TC removal in high temperature.

  1. Effect of radiation on tyrosine and tetracycline in poultry meat

    International Nuclear Information System (INIS)

    Vachin, I.; Pavlov, A.; Lashev, L.

    1994-01-01

    The effect of gamma rays on tissue level changes of unbound tyrosine and tetracycline was examined in comparative trials with broiler chicken meat. White meat and dark meat samples were taken from the killed chicken and were frozen at -18 o C. The three experimental groups were gamma irradiated with doses of 1.0, 1.5 and 2 kGy. The contents of the unbound antibiotics were microbiologically tested on 24th hour and 45th day after irradiation using Bacillus subtilis ATCC 6633, respectively Bac. mycoides HB 2 as test organisms. It was found that on 25th hour after irradiation both antibiotics were not significantly changed compared to the controls. After 45 days of storage a tendency towards decreasing the antibiotic concentrations in both the white and dark meat had been detected. (author)

  2. Use of tetracycline as complexing agent in analytical chemistry

    International Nuclear Information System (INIS)

    Nastasi, M.J.C.; Saiki, M.; Lima, F.W.

    1977-01-01

    The behavior of tetracyline as complexing agent in solvent extraction studies is presented. The extraction curves for the lanthanide elements, scandium, thorium, uranium and neptunium, are determined for the extraction system benzyl alcohol-tetracycline, as well as the acid and extractant dependences of extraction of the lanthanide elements. Separation of neptunium from uranium is formed by carrying out the extraction experiment at a proper pH value. Use is made of masking agents namely, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA), in order to obtain separations of uranium from scadium and lanthanides as well as of uranium and thorium, respectively. The extraction experiments are carried out by using radioisotopes of each element, except for uranium in which case the determinations are by using epithermal neutron activation analysis [pt

  3. Potential for tumor therapy with tritiated tetracycline. Summary evaluation

    International Nuclear Information System (INIS)

    Davis, R.C.; Wood, P.; Wood, L.L.; Mendelsohn, M.L.

    1976-01-01

    Reports of tetracycline accumulation in human and animal tumors have led a number of investigators to postulate that this drug, if radio-labeled, might have potential as a therapeutic or diagnostic agent. This paper describes attempts to investigate this potential for tritiated tetracycling. The therapeutic studies demonstrated that while a significant reduction in the growth rates of transplanted tumors could be obtained by the administration of heavy doses of TTC relative to uninjected controls, similar reductions were observed in the growth rates of tumors in animals receiving unlabeled TC. In the localization studies in rodents, the concentrations of TTC in normal tissues and tumors were compared and were correlated with the corresponding concentrations of 14 C-thymidine, a measure of proliferative activity

  4. Determination of stability constants of lanthanide complexes with tetracycline

    International Nuclear Information System (INIS)

    Saiki, Mitiko

    1975-01-01

    The stability constants of complexes compounds formed with tetracycline and lanthanides elements were determined for all lanthanides except promethium. The experimental procedure used was solvent extraction of the lanthanides labelled with their radioactive isotopes. It was shown that the formed complexes are mononuclear and that no hydroxo complexes or negatively charged complexes are formed in the experimental conditions of this work. Four methods of calculation were used for all complexes studied: the method of the average number of ligands, the method of limiting value, the method of two parameters and the method of weighted least squares. A comparison was made of the graphical methods with the method of least squares, showing the convenience of preceding least squares calculation by the graphical methods, in order to verify eventual mistakes of numerical data. It was shown the advantage of using radioisotopes of the elements for such a study, specially if the solvent extraction technique is used to-get the experimental data. (author)

  5. A Comprehensive Insight into Tetracycline Resistant Bacteria and Antibiotic Resistance Genes in Activated Sludge Using Next-Generation Sequencing

    OpenAIRE

    Huang, Kailong; Tang, Junying; Zhang, Xu-Xiang; Xu, Ke; Ren, Hongqiang

    2014-01-01

    In order to comprehensively investigate tetracycline resistance in activated sludge of sewage treatment plants, 454 pyrosequencing and Illumina high-throughput sequencing were used to detect potential tetracycline resistant bacteria (TRB) and antibiotic resistance genes (ARGs) in sludge cultured with different concentrations of tetracycline. Pyrosequencing of 16S rRNA gene revealed that tetracycline treatment greatly affected the bacterial community structure of the sludge. Nine genera cons...

  6. Organic acids enhance bioavailability of tetracycline in water to Escherichia coli for uptake and expression of antibiotic resistance.

    Science.gov (United States)

    Zhang, Yingjie; Boyd, Stephen A; Teppen, Brian J; Tiedje, James M; Li, Hui

    2014-11-15

    Tetracyclines are a large class of antimicrobials used most extensively in livestock feeding operations. A large portion of tetracyclines administered to livestock is excreted in manure and urine which is collected in waste lagoons. Subsequent land application of these wastes introduces tetracyclines into the soil environment, where they could exert selective pressure for the development of antibiotic resistance genes in bacteria. Tetracyclines form metal-complexes in natural waters, which could reduce their bioavailability for bacterial uptake. We hypothesized that many naturally-occurring organic acids could effectively compete with tetracyclines as ligands for metal cations, hence altering the bioavailability of tetracyclines to bacteria in a manner that could enhance the selective pressure. In this study, we investigated the influence of acetic acid, succinic acid, malonic acid, oxalic acid and citric acid on tetracycline uptake from water by Escherichia coli bioreporter construct containing a tetracycline resistance gene which induces the emission of green fluorescence when activated. The presence of the added organic acid ligands altered tetracycline speciation in a manner that enhanced tetracycline uptake by E. coli. Increased bacterial uptake of tetracycline and concomitant enhanced antibiotic resistance response were quantified, and shown to be positively related to the degree of organic acid ligand complexation of metal cations in the order of citric acid > oxalic acid > malonic acid > succinic acid > acetic acid. The magnitude of the bioresponse increased with increasing aqueous organic acid concentration. Apparent positive relation between intracellular tetracycline concentration and zwitterionic tetracycline species in aqueous solution indicates that (net) neutral tetracycline is the species which most readily enters E. coli cells. Understanding how naturally-occurring organic acid ligands affect tetracycline speciation in solution, and how speciation

  7. Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure

    International Nuclear Information System (INIS)

    Huang, Manhong; Qi, Fangfang; Wang, Jue; Xu, Qi; Lin, Li

    2015-01-01

    Highlights: • High-throughput sequencing was used to compare sludge bacteria with and without TC. • Bacterial diversity increased with TC addition despite of various oxygen conditions. • Total TRGs proliferated with TC addition in three kinds of sludge. • The concentration of efflux pump genes was the highest in the three groups of TRGs. - Abstract: Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A–C, E), was the highest among the three groups of TRGs in the different kinds of sludge

  8. Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Manhong, E-mail: egghmh@163.com; Qi, Fangfang; Wang, Jue; Xu, Qi; Lin, Li

    2015-11-15

    Highlights: • High-throughput sequencing was used to compare sludge bacteria with and without TC. • Bacterial diversity increased with TC addition despite of various oxygen conditions. • Total TRGs proliferated with TC addition in three kinds of sludge. • The concentration of efflux pump genes was the highest in the three groups of TRGs. - Abstract: Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A–C, E), was the highest among the three groups of TRGs in the different kinds of sludge.

  9. Rapid Detection of Tetracycline Residues in Duck Meat Using Surface Enhanced Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    Jinhui Zhao

    2016-01-01

    Full Text Available A rapid detection method based on surface enhanced Raman spectroscopy (SERS was proposed in this paper in order to realize the detection of tetracycline residues in duck meat. Firstly, surface enhanced Raman spectra characteristics of tetracycline aqueous solution, duck meat extract, and duck meat extract containing tetracycline were analyzed. Secondly, the effect of the addition amount of duck meat extract containing tetracycline on SERS intensity and the effect of the adsorption time on SERS intensity were discussed, respectively. Thirdly, SERS intensity ratio at 1272 and 1558 cm−1 (I1272/I1558 was used to establish the SERS calibration curve. A good linearity relationship between the tetracycline concentration in duck meat extract and I1272/I1558 was obtained, and the linear regression equation and the correlation coefficient (r were y=0.0177x+0.1213 and 0.950, respectively. The average recovery of tetracycline in duck meat extract was 101~108% with relative standard deviation (RSD of 2.4~4.6%. The experimental results showed that the method proposed in this paper was a good detection scheme for the rapid detection of tetracycline residues in duck meat.

  10. HPLC method validation for modernization of the tetracycline hydrochloride capsule USP monograph

    Directory of Open Access Journals (Sweden)

    Emad M. Hussien

    2014-12-01

    Full Text Available This paper is a continuation to our previous work aiming at development and validation of a reversed-phase HPLC for modernization of tetracycline-related USP monographs and the USP general chapter . Previous results showed that the method is accurate and precise for the assay of tetracycline hydrochloride and the limit of 4-epianhydrotetracycline impurity in the drug substance and oral suspension monographs. The aim of the current paper is to examine the feasibility of the method for modernization of USP tetracycline hydrochloride capsule monograph. Specificity, linearity, accuracy and precision were examined for tetracycline hydrochloride assay and 4-epianhydrotetracycline limit. The method was linear in the concentration range from 80% to 160% (r>0.9998 of the assay concentration (0.1 mg/mL for tetracycline hydrochloride and from 50% to 150% (r>0.997 of the acceptance criteria specified in tetracycline hydrochloride capsule monograph for 4-epianhydrotetracycline (NMT 3.0%. The recovery at three concentration levels for tetracycline hydrochloride assay was between 99% and 101% and the RSD from six preparations at the concentration 0.1 mg/mL is less than 0.6%. The recovery for 4-epianhydrotetracycline limit procedure over the concentration range from 50% to 150% is between 96% and 102% with RSD less than 5%. The results met the specified acceptance criteria.

  11. Contribution to the study of calcium metabolism in rats treated with tetracycline

    International Nuclear Information System (INIS)

    Goncalves, M.R.B.

    1980-01-01

    The tetracycline is one of the most used antibiotics. The interferences in the rats calcium metabolism were studied. Sixteen rats, R dutch type were treated with a 1 mg/100 g of corporal weight, of tetracycline twice a day, for 23 days. In the twentieth day of the treatment, a dose of Calcium 45 was administrated to verify thhe decay curve of the radionuclide plasmatic concentration. A control group of 16 rats was studied to compare the results. A significative decrease of the calcemy and of bone reabsorption in the group treated with tetracycline were observed. (L.M.J.)

  12. A Simple Surface-Enhanced Raman Spectroscopic Method for on-Site Screening of Tetracycline Residue in Whole Milk

    Directory of Open Access Journals (Sweden)

    Sagar Dhakal

    2018-02-01

    Full Text Available Therapeutic and subtherapeutic use of veterinary drugs has increased the risk of residue contamination in animal food products. Antibiotics such as tetracycline are used for mastitis treatment of lactating cows. Milk expressed from treated cows before the withdrawal period has elapsed may contain tetracycline residue. This study developed a simple surface-enhanced Raman spectroscopic (SERS method for on-site screening of tetracycline residue in milk and water. Six batches of silver colloid nanoparticles were prepared for surface enhancement measurement. Milk-tetracycline and water-tetracycline solutions were prepared at seven concentration levels (1000, 500, 100, 10, 1, 0.1, and 0.01 ppm and spiked with silver colloid nanoparticles. A 785 nm Raman spectroscopic system was used for spectral measurement. Tetracycline vibrational modes were observed at 1285, 1317 and 1632 cm−1 in water-tetracycline solutions and 1322 and 1621 cm−1 (shifted from 1317 and 1632 cm−1, respectively in milk-tetracycline solutions. Tetracycline residue concentration as low as 0.01 ppm was detected in both the solutions. The peak intensities at 1285 and 1322 cm−1 were used to estimate the tetracycline concentrations in water and milk with correlation coefficients of 0.92 for water and 0.88 for milk. Results indicate that this SERS method is a potential tool that can be used on-site at field production for qualitative and quantitative detection of tetracycline residues.

  13. [New aspects of safety assessment and food contamination with antibiotics of tetracycline group in the light of harmonization of hygienic standards in Russia and Customs Union with the international standards].

    Science.gov (United States)

    Onishchenko, G G; Sheveleva, S A; Khotimchenko, S A

    2012-01-01

    To address the issue of harmonization of Russian MRLs for tetracycline in food and on the basis of the tasks of preserving the value of hygienic standard for the more restrictive level than similar standards of the Codex Alimentarius Commission in this survey we analyzed the evidences of the negative effects of subingibitory amounts of these antibiotics (lying below the MIC for clinically relevant microorganisms). The inadequacy of the microbiological JECFA ADI and the necessity of using of methodology of analyzing the effects of biological active substances in small doses for assessing the risk of food contamination of tetracycline subingibitory concentrations were demonstrated. Current scientific information on the functions of antibiotics as signaling molecules in the microbial world and the role of tetracycline as a leading factor in the regulation of transcription in microorganisms and activation of the horizontal transfer of resistance genes transferred to the family of conjugative transposons Tn916-Tn1545 also was reviewed in paper. Evidence-based data regarding the basic contribution of subingibitory concentrations of tetracycline in the spread of worst transmissible type of antibiotic resistance and the formation of new pathogens, associated with it, are represented. To reduce the risk of direct adverse effects on microbial ecosystem in the human body and its habitat, and to minimize the indirect risk of new infections, the necessity of saving the current Russian level residues of tetracycline (< or = 0.01 mg/kg of product), which is low by contrast to the Codex MRLs (< or = 0.1-1.2 mg/kg), was proved. Tetracycline concentrations in food, regulated in Russian Federation, below 0.1 MIC for clinically significant microorganisms which aren't capable to initiation of the above described negative changes.

  14. Pharmacokinetics of metronidazole, tetracycline and bismuth in healthy volunteers after oral administration of compound tablets containing a combination of metronidazole, tetracycline hydrochloride and bismuth oxide.

    Science.gov (United States)

    Wu, Y; Ding, L; Huang, N-Y; Wen, A-D; Liu, B; Li, W-B

    2015-02-01

    To eradicate Helicobacter pylori in human pylorus and to heal duodenal ulcers, recently, a new formulation of combination tablets containing metronidazole 125 mg, tetracycline hydrochloride 125 mg and bismuth oxide 40 mg has been developed. To investigate the pharmacokinetics of metronidazole, tetracycline and bismuth in healthy Chinese volunteers after oral administration of the test formulation. A one-sequence, 3-period study was conducted in 12 Chinese healthy volunteers (6 male, 6 female). Volunteers each received single low dose (1 tablet) under fed condition in period 1, single high dose (3 tablets) under fasted condition in period 2, and single high dose (3 tablets) and multiple doses (3 tablets at once, 4 times daily for 7 consecutive days) under fed condition in period 3. Blood samples were collected and determined over 48 h in every period. After single high dose administration under fed condition, the C max of metronidazole, tetracycline and bismuth were 6.833 ± 0.742 μg/mL, 0.8513 ± 0.1253 μg/mL and 3.32 ± 1.89 ng/mL, respectively. The C max and AUC 0-48 of metronidazole increased in proportion to the doses within the tested dose range, but tetracycline and bismuth did not. Food caused 10% and 80% decrease of the C max for metronidazole and bismuth, respectively, but did not affect tetracycline. No gender effect was found on the pharmacokinetics of the 3 ingredients. In the steady state, the C av of metronidazole, tetracycline and bismuth were 20.75 ± 3.52 μg/mL, 1.900 ± 0.243 μg/mL and 5.61 ± 1.34 ng/mL, respectively. © Georg Thieme Verlag KG Stuttgart · New York.

  15. Spectrofluorimetric determination of lecithin using a tetracycline-europium probe

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ting [Department of Chemistry, Shandong Normal University, Jinan, Shandong 250014 (China); Jiang Chongqiu [Department of Chemistry, Shandong Normal University, Jinan, Shandong 250014 (China)]. E-mail: jiangchongqiu@sdnu.edu.cn

    2006-03-02

    Trace amount of lecithin (PC) was determined in the buffer solution of pH 5.7, using tetracycline (TC)-europium ion (Eu{sup 3+}) as a fluorescent probe. PC can remarkably enhance the fluorescence intensity of the TC-Eu{sup 3+} complex at {lambda} = 612 nm and the enhanced fluorescence intensity of Eu{sup 3+} is in proportion to the concentration of PC. Optimum conditions for the determination of PC were also investigated. The linear range and detection limit for the determination of PC are 4.0 x 10{sup -7} to 1.4 x 10{sup -5} mol/L and 3.9 x 10{sup -8} mol/L. This method is simple, practical and relatively free of interference from coexisting substances and can be successfully applied to assess PC in serum samples. Moreover, the enhancement mechanism of the fluorescence intensity in the TC-Eu{sup 3+} system, the TC-Eu{sup 3+}-PC system, and the TC-Eu{sup 3+}-PC-sodium dodecyl benzene sulfonate (SDS) system is also discussed.

  16. RESIDUES OF TETRACYCLINES, SULFONAMIDES AND TYLOSIN IN JAR HONEY FROM LATIUM REGION DURING 2005-2007

    Directory of Open Access Journals (Sweden)

    P. Pulcini

    2008-12-01

    Full Text Available During 3 years (2005-2007, the IZSLT, and the C.R.A. (ex Sezione di Apicoltura dell’Istituto Sperimentale per la Zoologia Agraria – sede di Roma, analized 165 samples of jar honey, from Latium Region, for melissopalinological, sensorial, chemical and physical analysis. The screening test for tetracyclines and tylosin were performed, respectively, with the Tetrasensor Honey kit and the ELISA kit for tylosin. HPLC-ESI-MSMS was used for sulfonamides and for all the samples that resulted positives to the screenig test for tetracyclines and tylosin. These the results: 49% of samples presented not in conformities; 18 samples (11% of the total were positives for tetracyclines; 15 - samples (9% positives for sulfonamides; 6 samples (4% positives for both tetracyclines and sulfonamides; 0 samples resulted positives for tylosin.

  17. Observations on the use of tetracycline and niacinamide as antipruritic agents in atopic dogs.

    OpenAIRE

    Beningo, K E; Scott, D W; Miller, W H; Rothstein, E

    1999-01-01

    Tetracycline and niacinamide were administered in combination to 19 atopic dogs to determine their effectiveness in controlling pruritus. The pruritus was controlled successfully in only one dog. One dog experienced diarrhea that was severe enough to warrant stopping the medication.

  18. Quantifying tetracycline resistance genes in swine waste anaerobic digester over a period of 100 days

    Science.gov (United States)

    Unregulated use of growth promoting antibiotics like Tetracyclines in agricultural feeds is becoming an increasing problem in antibiotic resistance. Undigested antibiotics leads to significant concentrations in livestock waste. These concentrations provide continuous selection pressure for the devel...

  19. Pharmacodynamics of doxycycline and tetracycline against Staphylococcus pseudintermedius

    DEFF Research Database (Denmark)

    Maaland, Marit Gaastra; Papich, Mark G.; Turnidge, John

    2013-01-01

    pharmacodynamic and target animal pharmacokinetic data were analyzed by Monte Carlo simulation (MCS) for development of MIC interpretive criteria. Optimal zone diameter breakpoints were defined using the standard error-rate bounded method.Both drugs displayed bacteriostatic activity and bimodal MIC distributions....... Doxycycline was more active on non-wild-type strains than tetracycline. MCS and target attainment analysis indicated a certainty of ≥ 90% for attaining an AUC/MIC ratio of > 25 after standard dosage of doxycycline (5 mg/kg q12h) for strains with MIC ≤ 0.125 μg/ml. Tetracycline predicted doxycycline...... susceptibility but current tetracycline breakpoints were inappropriate for interpretation of doxycycline susceptibility testing. Accordingly, dog-specific doxycycline MIC (S ≤ 0.125, I = 0.25 and R ≥ 0.5 μg/ml) and zone diameter (S ≥ 25, I= 21-24 and R ≤ 20 mm) breakpoints, and surrogate tetracycline MIC (S ≤ 0...

  20. Kinetics of tetracycline, oxytetracycline, and chlortetracycline adsorption and desorption on two acid soils

    DEFF Research Database (Denmark)

    Fernandez Calviño, David; Bermúdez-Couso, Alipio; Arias-Estévez, Manuel

    2015-01-01

    The purpose of this work was to quantify retention/release of tetracycline, oxytetracycline, and chlortetracycline on two soils, paying attention to sorption kinetics and to implications of the adsorption/desorption processes on transfer of these pollutants to the various environmental compartments....... We used the stirred flow chamber (SFC) procedure to achieve this goal. All three antibiotics showed high affinity for both soils, with greater adsorption intensity for soil 1, the one with the highest organic matter and Al and Fe oxides contents. Desorption was always ... tetracycline > oxytetracycline > chlortetracycline in soil 1, with similar values for the three antibiotics and the sequence tetracycline > chlortetracycline > oxytetracycline in soil 2. The desorption sequences were oxytetracycline > tetracycline > chlortetracycline in soil 1 and oxytetracycline...

  1. Survival and leaching of Tetracycline resistant bacteria and fecal indicators from manure in field scale experiments

    DEFF Research Database (Denmark)

    Bech, Tina; Amin, Mostofa; Lægdsmand, Mette

    The spreading of manure on agricultural land is an economic and practical solution for improving soil quality; however, animal manure frequently contains zoonotic pathogenic bacteria, such as certain Eschericia coli, Salmonella spp. and Campylobacter spp. The present experiment was conducted......) and Tetracycline resistant bacteria. The die-off of the different organisms was quantified showing an extended survival close to the manure string. Genomic DNA from 400 Tetracycline resistant bacteria was isolated and their phylogenetic relationship was established using BOX PCR showing that the main Tetracycline...... resistant bacterial species is E. coli. Drainage water from the field sites were collected weekly from one year prior to manure application, where no Tetracycline resistant bacteria were detected. For a period of 11 months following the first manure application, drainage water was sampled proportional...

  2. Spread of Staphylococcus aureus resistant to penicillin and tetracycline within and between dairy herds

    DEFF Research Database (Denmark)

    Waage, S.; Bjorland, J.; Caugant, D. A.

    2002-01-01

    One hundred and seven bovine isolates of penicillin and tetracycline resistant Staphylococcus aureus, recovered from 25 different dairy herds in various parts of Norway, were characterized using antimicrobial susceptibility testing, multilocus enzyme electrophoresis, ribotyping, plasmid analysis...... different counties, were assigned to 6 different strains. Seven out of these 8 isolates had the same plasmid restriction profile. In conclusion, penicillin and tetracycline resistant S. aureus occurring in dairy herds in Norway mainly seems to represent one particular strain that has achieved widespread...

  3. [The adhesive properties of two bonding systems to tetracycline stained dentin].

    Science.gov (United States)

    Liu, H L; Liang, K N; Cheng, L; Li, J Y; He, L B

    2016-01-01

    To investigate and compare the bonding properties of Single Bond 2 and SE Bond to tetracycline stained dentin in vitro. Ten extracted tetracycline stained human teeth and ten extracted normal human teeth were collected and the occlusal dentin surfaces of all extracted teeth were exposed. The tetracycline stained teeth and normal teeth were divided into two groups, respectively and randomly, based on the adhesives applied. Total-etch adhesive(Single Bond 2) and self-etch adhesive(SE Bond) were used. After application of the adhesives to the dentin surfaces, composite crowns were built up. After 24 h water storage, the teeth were sectioned longitudinally into sticks(0.9 mm×0.9 mm bonding area) for micro tensile testing or micro Raman spectroscopy detection. Bonding strength(μTBS) and resin conversion rate were analyzed using one-way ANOVA. The tetracycline Single Bond 2 group presented lower bonding strength[(16.17 ± 3.16) MPa] than the tetracycline SE Bond group[(25.82 ± 2.62) MPa], and also demonstrated lower bonding strength than the normal Single Bond 2 group[(29.13 ± 2.44) MPa] and the normal SE Bond group[(24.29±2.83) MPa] (P0.05). The resin conversion rate of tetracycline Single Bond 2 group[(55±6)%] was significantly lower than the tetracycline SE Bond group[(66±3)% ](P0.05). The bonding strength of total-etch adhesive system to the tetracycline stained dentin was significantly lower than that to the normal dentin.

  4. Susceptibilities of Eikenella corrodens, Prevotella intermedia, and Prevotella nigrescens Clinical Isolates to Amoxicillin and Tetracycline

    OpenAIRE

    Luong, N.; Tsai, J.; Chen, C.

    2001-01-01

    The AB Biodisk Etest showed that 106 (100%) and 98 (92%) isolates of Eikenella corrodens were susceptible to amoxicillin and tetracycline, respectively. Twenty-three (68%) Prevotella intermedia isolates and 14 (67%) Prevotella nigrescens isolates were susceptible to amoxicillin. Seventy-nine percent of the P. intermedia isolates and 67% of the P. nigrescens isolates were susceptible to tetracycline. A higher percentage of β-lactamase-producing isolates of P. intermedia and P. nigrescens were ...

  5. Performance and microbial community variations of anaerobic digesters under increasing tetracycline concentrations.

    Science.gov (United States)

    Xiong, Yanghui; Harb, Moustapha; Hong, Pei-Ying

    2017-07-01

    The impact of different concentrations of tetracycline on the performance of anaerobic treatment was evaluated. Results revealed that for all of the tested tetracycline concentrations, no major sustained impact on methane production was observed. Instead, a significant increase in propionic acid was observed in the reactor subjected to the highest concentration of tetracycline (20 mg/L). Microbial community analyses suggest that an alternative methanogenic pathway, specifically that of methanol-utilizing methanogens, may be important for ensuring the stability of methane production in the presence of high tetracycline concentrations. In addition, the accumulation of propionate was due to an increase in volatile fatty acids (VFA)-producing bacteria coupled with a reduction in propionate utilizers. An increase in the abundance of tetracycline resistance genes associated with ribosomal protection proteins was observed after 30 days of exposure to high concentrations of tetracycline, while other targeted resistance genes showed no significant changes. These findings suggest that anaerobic treatment processes can robustly treat wastewater with varying concentrations of antibiotics while also deriving value-added products and minimizing the dissemination of associated antibiotic resistance genes.

  6. Detection of Tetracycline in Milk using NIR Spectroscopy and Partial Least Squares

    Science.gov (United States)

    Wu, Nan; Xu, Chenshan; Yang, Renjie; Ji, Xinning; Liu, Xinyuan; Yang, Fan; Zeng, Ming

    2018-02-01

    The feasibility of measuring tetracycline in milk was investigated by near infrared (NIR) spectroscopic technique combined with partial least squares (PLS) method. The NIR transmittance spectra of 40 pure milk samples and 40 tetracycline adulterated milk samples with different concentrations (from 0.005 to 40 mg/L) were obtained. The pure milk and tetracycline adulterated milk samples were properly assigned to the categories with 100% accuracy in the calibration set, and the rate of correct classification of 96.3% was obtained in the prediction set. For the quantitation of tetracycline in adulterated milk, the root mean squares errors for calibration and prediction models were 0.61 mg/L and 4.22 mg/L, respectively. The PLS model had good fitting effect in calibration set, however its predictive ability was limited, especially for low tetracycline concentration samples. Totally, this approach can be considered as a promising tool for discrimination of tetracycline adulterated milk, as a supplement to high performance liquid chromatography.

  7. Electronic-property dependent interactions between tetracycline and graphene nanomaterials in aqueous solution.

    Science.gov (United States)

    He, Lin; Liu, Fei-Fei; Zhao, Mengyao; Qi, Zhen; Sun, Xuefei; Afzal, Muhammad Zaheer; Sun, Xiaomin; Li, Yanhui; Hao, Jingcheng; Wang, Shuguang

    2018-04-01

    Understanding the interactions between graphene nanomaterials (GNMs) and antibiotics in aqueous solution is critical to both the engineering applications of GNMs and the assessment of their potential impact on the fate and transport of antibiotics in the aquatic environment. In this study, adsorption of one common antibiotic, tetracycline, by graphene oxide (GO) and reduced graphene oxide (RGO) was examined with multi-walled carbon nanotubes (MWCNTs) and graphite as comparison. The results showed that the tetracycline adsorption capacity by the four selected carbonaceous materials on the unit mass basis followed an order of GO>RGO>MWCNTs>graphite. Upon normalization by surface area, graphite, RGO and MWCNTs had almost the same high tetracycline adsorption affinity while GO exhibited the lowest. We proposed π-electron-property dependent interaction mechanisms to explain the observed different adsorption behaviors. Density functional theory (DFT) calculations suggested that the oxygen-containing functional groups on GO surface reduced its π-electron-donating ability, and thus decreased the π-based interactions between tetracycline and GO surface. Comparison of adsorption efficiency at different pH indicated that electrostatic interaction also played an important role in tetracycline-GO interactions. Site energy analysis confirmed a highly heterogeneous distribution of the binding sites and strong tetracycline binding affinity of GO surface. Copyright © 2017. Published by Elsevier B.V.

  8. Changes in weight and body fat after use of tetracycline and Lactobacillus gasseri in rats

    Directory of Open Access Journals (Sweden)

    Jorge José Marciano

    2017-04-01

    Full Text Available ABSTRACT Recent studies have shown a role of intestinal microbiota in obesity. The consumption of antibiotics in the last 70 years has led to changes in intestinal microbiota, which has led to weight gain and body fat accumulation. To evaluate the possibility of weight gain induced by antibiotics and the possible protective effect of probiotics, we divided 45 animals (Rattus norvegicus into groups and administered the following treatments over two weeks: tetracycline, tetracycline + Lactobacillus gasseri, and NaCl. The animals were weighed over the course of 8 weeks, and at the end of the treatment period, they were measured and subjected to bioelectrical impedance analysis. The results show that the group receiving tetracycline alone had a higher body mass index (p=0.030, a greater Lee index (p=0.008, and a lower body water percentage than the control group, indicating a greater accumulation of body fat. The group receiving the probiotics with tetracycline presented similar results to the control group, indicating a possible protective effect of body fat accumulation in the group receiving tetracycline alone. The results show that tetracycline increased the concentration of body fat, and the use of probiotics was associated with an ability to protect the animals from the pro-obesity effect.

  9. Instability of chlorophyll in yellow lupin seedlings grown in soil contaminated with ciprofloxacin and tetracycline.

    Science.gov (United States)

    Rydzyński, Dariusz; Piotrowicz-Cieślak, Agnieszka I; Grajek, Hanna; Michalczyk, Dariusz J

    2017-10-01

    With increasing soil concentrations of ciprofloxacin and tetracycline a decrease of leaf chlorophyll content was observed. Tetracycline was more detrimental than ciprofloxacin. The chlorophyll content in plants growing for ten days on a tetracycline containing soil decreased by 68%. The decrease of chlorophyll concentration was even sharper in new leaves that formed after application of the antibiotic (up to 81% drop). The comparison of absorption spectra of commercial, reagent grade chlorophyll, alone and incubated with antibiotics, has shown that ciprofloxacin and tetracycline can react directly with chlorophyll and decrease its concentration by 47.7% and 48.5%, respectively. The changes in fluorescence spectra confirmed the formation of chlorophyll degradation product. The chlorophyll decay was a second order reaction and depended on antibiotic concentration and duration of exposure. Reaction rate constants differed with antibiotics and their soil concentrations. With increasing contents of antibiotics in soil the constant of chlorophyll degradation rate in lupin plants increased from k = 870 M -1 day -1 for 3 mg ciprofloxacin to k = 2490 M -1 day -1 for 90 mg ciprofloxacin, and in the case of tetracycline the reaction rate constant increased from k = 1330 M -1 day -1 to k = 2910 M -1 day -1 . The sensitivity of chlorophyll to ciprofloxacin and tetracycline was confirmed by determining EC and TU indices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Performance and microbial community variations of anaerobic digesters under increasing tetracycline concentrations

    KAUST Repository

    Xiong, Yanghui

    2017-04-01

    The impact of different concentrations of tetracycline on the performance of anaerobic treatment was evaluated. Results revealed that for all of the tested tetracycline concentrations, no major sustained impact on methane production was observed. Instead, a significant increase in propionic acid was observed in the reactor subjected to the highest concentration of tetracycline (20 mg/L). Microbial community analyses suggest that an alternative methanogenic pathway, specifically that of methanol-utilizing methanogens, may be important for ensuring the stability of methane production in the presence of high tetracycline concentrations. In addition, the accumulation of propionate was due to an increase in volatile fatty acids (VFA)-producing bacteria coupled with a reduction in propionate utilizers. An increase in the abundance of tetracycline resistance genes associated with ribosomal protection proteins was observed after 30 days of exposure to high concentrations of tetracycline, while other targeted resistance genes showed no significant changes. These findings suggest that anaerobic treatment processes can robustly treat wastewater with varying concentrations of antibiotics while also deriving value-added products and minimizing the dissemination of associated antibiotic resistance genes.

  11. Biotransformation of tetracycline by a novel bacterial strain Stenotrophomonas maltophilia DT1.

    Science.gov (United States)

    Leng, Yifei; Bao, Jianguo; Chang, Gaofeng; Zheng, Han; Li, Xingxing; Du, Jiangkun; Snow, Daniel; Li, Xu

    2016-11-15

    Although several abiotic processes have been reported that can transform antibiotics, little is known about whether and how microbiological processes may degrade antibiotics in the environment. This work isolated one tetracycline degrading bacterial strain, Stenotrophomonas maltophilia strain DT1, and characterized the biotransformation of tetracycline by DT1 under various environmental conditions. The biotransformation rate was the highest when the initial pH was 9 and the reaction temperature was at 30°C, and can be described using the Michaelis-Menten model under different initial tetracycline concentrations. When additional substrate was present, the substrate that caused increased biomass resulted in a decreased biotransformation rate of tetracycline. According to disk diffusion tests, the biotransformation products of tetracycline had lower antibiotic potency than the parent compound. Six possible biotransformation products were identified, and a potential biotransformation pathway was proposed that included sequential removal of N-methyl, carbonyl, and amine function groups. Results from this study can lead to better estimation of the fate and transport of antibiotics in the environment and has the potential to be utilized in designing engineering processes to remove tetracycline from water and soil. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Tetracycline resistance and presence of tetracycline resistance determinants .i.tet./i.(V) and .i.tap./i. in rapidly growing mycobacteria from agricultural soils and clinical isolates

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Chroňáková, Alica; Volná, Lucie; Němec, Jan; Ulmann, V.; Scharfen, J.; Elhottová, Dana

    2012-01-01

    Roč. 27, č. 4 (2012), s. 413-422 ISSN 1342-6311 R&D Projects: GA ČR GAP504/10/2077; GA MŠk LC06066 Institutional support: RVO:60077344 Keywords : efflux pump * rapidly growing Mycobacterium * tetracycline resistance * tap * tet (V) Subject RIV: EH - Ecology, Behaviour Impact factor: 2.444, year: 2012

  13. Effect of tetracycline on transfer and establishment of the tetracycline-inducible conjugative transposon Tn916 in the guts of gnotobiotic rats

    DEFF Research Database (Denmark)

    Bahl, Martin I.; Sørensen, Søren J.; Hansen, Lars H.

    2004-01-01

    and intestinal segments were monitored by using bacterial biosensors carrying a transcriptional fusion of a tetracycline-regulated promoter and a lacZ reporter gene. Chromosomal locations of Tn916 in transconjugants isolated either from the same animal or from different animals were compared by Southern blot...

  14. The impact of a freshwater fish farm on the community of tetracycline-resistant bacteria and the structure of tetracycline resistance genes in river water.

    Science.gov (United States)

    Harnisz, Monika; Korzeniewska, Ewa; Gołaś, Iwona

    2015-06-01

    The aim of this study was to assess the impact of a fish farm on the structure of antibiotic resistant bacteria and antibiotic resistance genes in water of Drwęca River. Samples of upstream river waters; post-production waters and treated post-production waters from fish farm; as well as downstream river waters were monitored for tetracycline resistant bacteria, tetracycline resistant genes, basic physico-chemical parameters and tetracyclines concentration. The river waters was characterized by low levels of pollution, which was determined based on water temperature, pH and concentrations of dissolved oxygen and tetracycline antibiotics. Culture-dependent (heterotrophic plate counts, counts of bacteria resistant to oxytetracycline (OTC(R)) and doxycycline (DOX(R)), minimum inhibitory concentrations for oxytetracycline and doxycycline, multidrug resistance of OTC(R) and DOX(R), qualitative composition of OTC(R) and DOX(R), prevalence of tet genes in resistant isolates) and culture-independent surveys (quantity of tet gene copies) revealed no significant differences in the abundance of antibiotic-resistant bacteria and antibiotic resistance genes between the studied samples. The only way in which the fish farm influenced water quality in the Drwęca River was by increasing the diversity of tetracycline-resistance genes. However, it should also be noted that the bacteria of the genera Aeromonas sp. and Acinetobacter sp. were able to transfer 6 out of 13 tested tet genes into Escherichiacoli, which can promote the spread of antibiotic resistance in the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Selective Pressure Promotes Tetracycline Resistance of Chlamydia Suis in Fattening Pigs.

    Directory of Open Access Journals (Sweden)

    Sabrina Wanninger

    Full Text Available In pigs, Chlamydia suis has been associated with respiratory disease, diarrhea and conjunctivitis, but there is a high rate of inapparent C. suis infection found in the gastrointestinal tract of pigs. Tetracycline resistance in C. suis has been described in the USA, Italy, Switzerland, Belgium, Cyprus and Israel. Tetracyclines are commonly used in pig production due to their broad-spectrum activity and relatively low cost. The aim of this study was to isolate clinical C. suis samples in cell culture and to evaluate their antibiotic susceptibility in vitro under consideration of antibiotic treatment on herd level. Swab samples (n = 158 identified as C. suis originating from 24 farms were further processed for isolation, which was successful in 71% of attempts with a significantly higher success rate from fecal swabs compared to conjunctival swabs. The farms were divided into three treatment groups: A farms without antibiotic treatment, B farms with prophylactic oral antibiotic treatment of the whole herd consisting of trimethoprime, sulfadimidin and sulfathiazole (TSS, or C farms giving herd treatment with chlortetracycline with or without tylosin and sulfadimidin (CTS. 59 isolates and their corresponding clinical samples were selected and tested for the presence or absence of the tetracycline resistance class C gene [tet(C] by conventional PCR and isolates were further investigated for their antibiotic susceptibility in vitro. The phenotype of the investigated isolates was either classified as tetracycline sensitive (Minimum inhibitory concentration [MIC] < 2 μg/ml, intermediate (2 μg/ml ≤ MIC < 4 μg/ml or resistant (MIC ≥ 4 μg/ml. Results of groups and individual pigs were correlated with antibiotic treatment and time of sampling (beginning/end of the fattening period. We found clear evidence for selective pressure as absence of antibiotics led to isolation of only tetracycline sensitive or intermediate strains whereas tetracycline

  16. Tetracycline removal during wastewater treatment in high-rate algal ponds

    International Nuclear Information System (INIS)

    Godos, Ignacio de; Muñoz, Raúl; Guieysse, Benoit

    2012-01-01

    Highlights: ► Tetracycline removal was most likely caused by photodegradation and biosorption. ► Tetracycline presence was linked to biomass deflocculation and poor settleability. ► Deflocculation did not impact treatment efficiency. ► Deflocculation may hamper biomass recover during full-scale treatment. - Abstract: With the hypothesis that light supply can impact the removal of veterinary antibiotics during livestock wastewater treatment in high rate algal ponds (HRAPs), this study was undertaken to determine the mechanisms of tetracycline removal in these systems. For this purpose, two HRAPs were fed with synthetic wastewater for 46 days before tetracycline was added at 2 mg L −1 to the influent of one of the reactors (Te-HRAP). From day 62, dissolved tetracycline removal stabilized around 69 ± 1% in the Te-HRAP and evidence from batch assays suggests that this removal was mainly caused by photodegradation and biosorption. Tetracycline addition was followed by the deflocculation of the Te-HRAP biomass but had otherwise no apparent impact on the removal of the chemical oxygen demand (COD) and biomass productivity. The results from the batch assays also suggested that the light-shading and/or pollutant-sequestrating effects of the biomass limited tetracycline removal in the pond. For the first time, these results demonstrate that the shallow geometry of HRAPs is advantageous to support the photodegradation of antibiotics during wastewater biological treatment but that the presence of these pollutants could hamper biomass recovery. These findings have significant implications for algal-based environmental biotechnologies and must be confirmed under field conditions.

  17. Tetracycline removal during wastewater treatment in high-rate algal ponds

    Energy Technology Data Exchange (ETDEWEB)

    Godos, Ignacio de [School of Engineering and Advanced Technology, Massey University, Private Bag 11222, Palmerston North (New Zealand); Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n, 47011, Valladolid (Spain); Department of Biodiversity and Environmental Management, University of Leon, Campus Vegazana, 24071 Leon (Spain); Munoz, Raul [Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n, 47011, Valladolid (Spain); Guieysse, Benoit, E-mail: B.J.Guieysse@massey.ac.nz [School of Engineering and Advanced Technology, Massey University, Private Bag 11222, Palmerston North (New Zealand)

    2012-08-30

    Highlights: Black-Right-Pointing-Pointer Tetracycline removal was most likely caused by photodegradation and biosorption. Black-Right-Pointing-Pointer Tetracycline presence was linked to biomass deflocculation and poor settleability. Black-Right-Pointing-Pointer Deflocculation did not impact treatment efficiency. Black-Right-Pointing-Pointer Deflocculation may hamper biomass recover during full-scale treatment. - Abstract: With the hypothesis that light supply can impact the removal of veterinary antibiotics during livestock wastewater treatment in high rate algal ponds (HRAPs), this study was undertaken to determine the mechanisms of tetracycline removal in these systems. For this purpose, two HRAPs were fed with synthetic wastewater for 46 days before tetracycline was added at 2 mg L{sup -1} to the influent of one of the reactors (Te-HRAP). From day 62, dissolved tetracycline removal stabilized around 69 {+-} 1% in the Te-HRAP and evidence from batch assays suggests that this removal was mainly caused by photodegradation and biosorption. Tetracycline addition was followed by the deflocculation of the Te-HRAP biomass but had otherwise no apparent impact on the removal of the chemical oxygen demand (COD) and biomass productivity. The results from the batch assays also suggested that the light-shading and/or pollutant-sequestrating effects of the biomass limited tetracycline removal in the pond. For the first time, these results demonstrate that the shallow geometry of HRAPs is advantageous to support the photodegradation of antibiotics during wastewater biological treatment but that the presence of these pollutants could hamper biomass recovery. These findings have significant implications for algal-based environmental biotechnologies and must be confirmed under field conditions.

  18. Comparative toxicity and carcinogenicity studies of tetracycline and oxytetracycline in rats and mice.

    Science.gov (United States)

    Dietz, D D; Abdo, K M; Haseman, J K; Eustis, S L; Huff, J E

    1991-08-01

    Two-year toxicity and carcinogenicity studies of oxytetracycline hydrochloride and tetracycline hydrochloride, two structurally similar and widely used antibiotics, were performed in F344/N rats and B6C3F1 mice. Rats and mice were continuously exposed via their diet to the following levels of antibiotic: oxytetracycline HCl--rats 0, 25,000, or 50,000 ppm; mice 0,6,300, or 12,500 ppm; tetracycline HCl--rats and mice 0, 12,500, or 25,000 ppm. On a milligram per kilogram of body weight basis these exposures represent doses that are 20 to 140 times daily human therapeutic doses. Dose-related increased survival was noted among oxytetracycline-treated male rats and tetracycline-treated female rats and male mice, while treatment-related reduced body weight gain occurred in oxytetracycline- and tetracycline-treated mice. Microscopic changes included fatty metamorphosis and focal cellular change in livers of oxytetracycline-treated male rats and basophilic cytoplasmic and clear cell change in livers of tetracycline-treated male rats. The only neoplastic changes were a marginally increased trend in pheochromocytoma of the adrenal medulla (equivocal evidence only) among oxytetracycline-exposed male rats (12/50 controls, 19/50 low dose, 24/50 high dose) and an increased incidence of pituitary adenoma or adenocarcinoma among high-dose oxytetracycline-treated female rats (20/50 controls, 32/50 high dose). Although oxytetracycline and tetracycline appeared to increase the incidence of pituitary hyperplasia in high-dose male and female rats, respectively, the total incidence of proliferative changes (hyperplasia, adenoma, and adenocarcinoma) was not affected by antibiotic exposure. The results from these studies therefore support the notion that neither antibiotic is carcinogenic in rodents. There were several negative trends suggesting possible protective effects by both these tetracycline analogs against certain spontaneous neoplastic and non-neoplastic changes.

  19. Role of tetracycline speciation in the bioavailability to Escherichia coli for uptake and expression of antibiotic resistance.

    Science.gov (United States)

    Zhang, Yingjie; Boyd, Stephen A; Teppen, Brian J; Tiedje, James M; Li, Hui

    2014-05-06

    Tetracycline contains ionizable functional groups that manifest several species with charges at different locales and differing net charge; the fractional distribution of each species depends on pH-pKa relationship in the aqueous phase. In nature, these species interact with naturally abundant cations (e.g., Ca(2+) and Mg(2+)) to form metal-tetracycline complexes in water. In this study, we used Escherichia coli MC4100/pTGM whole-cell bioreporter to investigate tetracycline uptake from solution under varying conditions of pH, salt composition and concentration by quantifying the corresponding expression of antibiotic resistance gene. The expression of antibiotic resistance gene in the E. coli bioreporter responded linearly to intracellular tetracycline concentration. Less tetracycline entered E. coli cells at solution pH of 8.0 than at pH 6.0 or 7.0 indicating reduced bioavailability of the antibiotic at higher pH. Both Mg(2+) and Ca(2+) in solution formed metal-tetracycline complexes which reduced uptake of tetracycline by E. coli hence diminishing the bioresponse. Among the various tetracycline species present in solution, including both metal-complexed and free (noncomplexed) species, zwitterionic tetracycline was identified as the predominant species that most readily passed through the cell membrane eliciting activation of the antibiotic resistance gene in E. coli. The results indicate that the same total concentration of tetracycline in ambient solution can evoke very different expression of antibiotic resistance gene in the exposed bacteria due to differential antibiotic uptake. Accordingly, geochemical factors such as pH and metal cations can modulate the selective pressure exerted by tetracycline for development and enrichment of antibiotic resistant bacteria. We suggest that tetracycline speciation analysis should be incorporated into the risk assessment framework for evaluating environmental exposure and the corresponding development of antibiotic

  20. Epigallocatechin-3-gallate and tetracycline differently affect ataxin-3 fibrillogenesis and reduce toxicity in spinocerebellar ataxia type 3 model.

    Science.gov (United States)

    Bonanomi, Marcella; Natalello, Antonino; Visentin, Cristina; Pastori, Valentina; Penco, Amanda; Cornelli, Giuseppina; Colombo, Giorgio; Malabarba, Maria G; Doglia, Silvia M; Relini, Annalisa; Regonesi, Maria E; Tortora, Paolo

    2014-12-15

    The polyglutamine (polyQ)-containing protein ataxin-3 (AT3) triggers the neurodegenerative disease spinocerebellar ataxia type 3 (SCA3) when its polyQ tract is expanded beyond a critical length. This results in protein aggregation and generation of toxic oligomers and fibrils. Currently, no effective treatment is available for such and other polyQ diseases. Therefore, plenty of investigations are being carried on to assess the mechanism of action and the therapeutic potential of anti-amyloid agents. The polyphenol compound epigallocatechin-3-gallate (EGCG) and tetracycline have been shown to exert some effect in preventing fibrillogenesis of amyloidogenic proteins. Here, we have incubated an expanded AT3 variant with either compound to assess their effects on the aggregation pattern. The process was monitored by atomic force microscopy and Fourier transform infrared spectroscopy. Whereas in the absence of any treatment, AT3 gives rise to amyloid β-rich fibrils, whose hallmark is the typical glutamine side-chain hydrogen bonding, when incubated in the presence of EGCG it generated soluble, SDS-resistant aggregates, much poorer in β-sheets and devoid of any ordered side-chain hydrogen bonding. These are off-pathway species that persist until the latest incubation time and are virtually absent in the control sample. In contrast, tetracycline did not produce major alterations in the structural features of the aggregated species compared with the control, but substantially increased their solubility. Both compounds significantly reduced toxicity, as shown by the MTT assay in COS-7 cell line and in a transgenic Caenorhabditis elegans strain expressing in the nervous system an AT3 expanded variant in fusion with GFP. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Spread of tetracycline resistance genes at a conventional dairy farm

    Directory of Open Access Journals (Sweden)

    Martina eKyselkova

    2015-05-01

    Full Text Available The use of antibiotics in animal husbandry contributes to the worldwide problem of increasing antibiotic resistance in animal and human pathogens. Intensive animal production is considered an important source of antibiotic resistance genes released to the environment, while the contribution of smaller farms remains to be evaluated. Here we monitor the spread of tetracycline resistance (TC-r genes at a middle-size conventional dairy farm, where chlortetracycline (CTC, as intrauterine suppository is prophylactically used after each calving. Our study has shown that animals at the farm acquired the TC-r genes in their early age (1-2 weeks, likely due to colonization with TC-resistant bacteria from their mothers and/or the farm environment. The relative abundance of the TC-r genes tet(W, tet(Q and tet(M in fresh excrements of calves was about 1-2 orders of magnitude higher compared to heifers and dairy cows, possibly due to the presence of antibiotic residues in milk fed to calves. The occurrence and abundance of TC-r genes in fresh excrements of heifers and adult cows remained unaffected by intrauterine CTC applications, with tet(O, tet(Q and tet(W representing a ‘core TC-resistome’ of the farm, and tet(A, tet(M, tet(Y and tet(X occurring occasionally. The genes tet(A, tet(M, tet(Y and tet(X were shown to be respectively harbored by Shigella, Lactobacillus and Clostridium, Acinetobacter, and Wautersiella. Soil in the farm proximity, as well as field soil to which manure from the farm was applied, was contaminated with TC-r genes occurring in the farm, and some of the TC-r genes persisted in the field over 3 months following the manure application. Concluding, our study shows that antibiotic resistance genes may be a stable part of the intestinal metagenome of cattle even if antibiotics are not used for growth stimulation, and that smaller dairy farms may also contribute to environmental pollution with antibiotic resistance genes.

  2. Characterization of tetracycline-resistant bacteria in an urbanizing subtropical watershed.

    Science.gov (United States)

    Sullivan, B A; Gentry, T; Karthikeyan, R

    2013-09-01

    The objective of this study was to determine whether varying levels of urbanization influence the dominant bacterial species of mildly resistant (0·03 mmol l(-1) tetracycline) and highly resistant (0·06 mmol l(-1) tetracycline) bacteria in sediment and water. Also, the level of urbanization was further evaluated to determine whether the diversity of tetracycline resistance genes present in the isolates and the capability of transferring their resistance were influenced. Sediment and water samples collected from five sampling sites were plated in triplicate on nutrient agar plates with a mild dose (0·03 mmol l(-1) ) and a high dose (0·06 mmol l(-1) ) of tetracycline. Five colonies from each plate plus an additional five from each triplicate group were randomly selected and isolated on nutrient agar containing 0·03 mmol l(-1) tetracycline (400 isolates). The isolates were identified by 16S rRNA gene sequencing and comparison to GenBank using blast. The isolates were also screened for 15 tetracycline resistance genes using a multiplex PCR assay and their ability to transfer resistance through conjugation experiments using a kanamycin-resistant Escherichia. coli K-12 strain labelled with a green fluorescent protein gene. Results from this study indicate that the dominant resistant organisms in this watershed are Acinetobacter spp., Chryseobacterium spp., Serratia spp., Pseudomonas spp., Aeromonas spp. and E. coli. All of these organisms are Gram negative and are closely related to pathogenic species. A majority of the isolates (66%) were capable of transferring their resistance, and there was a greater incidence of tet resistance transfer with increasing urbanization. Also, it was determined that the dominant resistance genes in the watershed are tet(W) and tet(A). Urbanization significantly affected dominant tetracycline-resistant bacteria species, but did not affect dominant resistance genes. There was correlation between increased urbanization with an

  3. Tetracycline Resistance Genes Identified from Distinct Soil Environments in China by Functional Metagenomics.

    Science.gov (United States)

    Wang, Shaochen; Gao, Xia; Gao, Yuejiao; Li, Yanqing; Cao, Mingming; Xi, Zhenhua; Zhao, Lixing; Feng, Zhiyang

    2017-01-01

    Soil microbiota represents one of the ancient evolutionary origins of antibiotic resistance and has been increasingly recognized as a potentially vast unstudied reservoir of resistance genes with possibilities to exchange with pathogens. Tetracycline resistance is one of the most abundant antibiotic resistances that may transfer among clinical and commensal microorganisms. To investigate tetracycline resistance genes from soil bacteria in different habitats, we performed functional analysis of three metagenomic libraries derived from soil samples collected from Yunnan, Sichuan, and Tibet, respectively, in China. We found efflux transporter genes form all the libraries, including 21 major facilitator superfamily efflux pump genes and one multidrug and toxic compound extrusion (MATE) transporter gene. Interestingly, we also identified two tetracycline destructase genes, belonging to a newly described family of tetracycline-inactivating enzymes that scarcely observed in clinical pathogens, from the Tibet library. The inactivation activity of the putative enzyme was confirmed in vitro by biochemical analysis. Our results indicated that efflux pumps distributed predominantly across habitats. Meanwhile, the mechanism of enzymatic inactivation for tetracycline resistance should not be neglected and merits further investigation.

  4. In vitro susceptibility pattern of extended spectrum ?-lactamase producing gram negative bacilli against tetracyclines

    International Nuclear Information System (INIS)

    Gill, M.M.

    2015-01-01

    Extended Spectrum beta-lactamases (ESBLs) are emerging as common nosocomial pathogens and important cause of mortality and morbidity, if not treated properly. The need of the hour is to find effective treatment options for dealing with ESBL producing organisms. This study was aimed to evaluate in vitro susceptibility pattern of extended spectrum beta-lactamase producers against tetracyclines. Methods: This descriptive cross-sectional study was carried out in the department of Microbiology, Army Medical College, Rawalpindi, National University of Sciences and Technology over a period of 6 months. Seventy eight non-duplicate isolates were included in the study. ESBL detection was done using Jarlier et al method. In vitro susceptibility of tetracyclines like tetracycline, doxycycline, minocycline and tigecycline was then tested using Modified Kirby Bauer disc diffusion method. The zones of inhibition were measured after completion of incubation period and interpreted as per CLSI and FDA guidelines. Results: Approximately 56.4% of the isolates were Escherichia coli, 28.2% were Klebsiella pneumoniae, 10.26% were Enterobacter species, and 2.6% were each Klebsiella oxytoca and Acinetobacter species. ESBLs were found to be most sensitive to tigecycline, intermediate in susceptibility to minocycline while least sensitive to doxycycline and tetracycline. Conclusion: Among tetracyclines, tigecycline has best in vitro susceptibility against ESBL producing Gram negative rods. (author)

  5. Resistance of Helicobacter pylori to tetracycline, amoxicillin, clarithromycin and metronidazole in Israeli children and adults.

    Science.gov (United States)

    Peretz, Avi; Paritsky, Maya; Nasser, Omar; Brodsky, Diana; Glyatman, Tatyana; Segal, Sofia; On, Avi

    2014-08-01

    The aim of this study was to examine Helicobacter pylori-resistance rate to different antibiotics: tetracycline, amoxicillin, clarithromycin and metronidazole, and to compare eradication rates in adults and children in Israel. The study was based on the hypothesis of high-resistance rates to clarithromycin and metronidazole especially in adults and overall low-resistance rates to tetracycline and amoxicillin. One seventy six biopsies from patients with dyspeptic symptoms were cultured of which 100 were from adults (19-79 years) and 76 from children (7-17 years). All positive cultures were examined by Epsilometer test for MIC determination against tetracycline, amoxicillin, clarithromycin and metronidazole. 48.3% (85 out of 176) were H. pylori positive, of which 44% were from adults and 54% from children. Antibiotic resistance was seen in 31 out of 44 (70.5%) for metronidazole, 1 out of 44 (2.3%) for amoxicillin, 10 out of 44 (22.3%) for clarithromycin and 1 out of 44 (2.3%) for tetracycline among adults. Antibiotic resistance was seen in 10 out of 41 (24.4%) for metronidazole, 5 out of 41 (12.2%) for amoxicillin, 10 out of 41 (24.4%) for clarithromycin and 1 out of 41 (2.4%) for tetracycline among children. High rates of H. pylori resistance to metronidazole and clarithromycin was found especially among adults. Therefore, to increase the success rate of anti-H. pylori treatment, other classes of antibiotics need to be considered.

  6. BIOCHEMICAL AND HISTOLOGICAL EFFECTS OF TETRACYCLINES ON SPONTANEOUS OSTEOARTHRITIS IN GUINEA PIGS

    Directory of Open Access Journals (Sweden)

    Edin De Bri

    2011-05-01

    Full Text Available Matrix metalloproteinases (MMPs are mediators in connective tissue destruction in a variety of pathologic processes. Recently discovered chemically modified tetracyclines have been found to be effective inhibitors of MMP mediated connective tissue degradation in both rheumatoid arthritis (RA and osteoarthritis (OA. The Hartley guinea pig model has been described with a high incidence of spontaneous OA-like changes in the knee joint. Therefore we have studied the effect of two tetracyclines, doxycycline (Dox and chemically modified tetracycline-7 (CMT-7 which have both previously been shown as potent MMP inhibitors. We found that prophylactic orally given CMT-7 decreases OA changes in the knee joints both in vitro and in vivo in the guinea pig OA model. OA changes were most severe in the central compartment of the medial condyle in the control group. Cartilage fibrillation and destruction, in addition to subchondral bone sclerosis and cyst formation were all less in the CMT-7 treated group compared with controls. Collagen, hyaluronan and proteoglycan content in cartilage was higher in the CMT-7 treated group compared with controls. In contrast, OA changes were not decreased in the Dox group. These results show that tetracyclines, but not all tetracyclines, can reduce the severity of OA in the guinea pig model of spontaneous OA.

  7. Tetracycline Resistance Genes Identified from Distinct Soil Environments in China by Functional Metagenomics

    Directory of Open Access Journals (Sweden)

    Shaochen Wang

    2017-07-01

    Full Text Available Soil microbiota represents one of the ancient evolutionary origins of antibiotic resistance and has been increasingly recognized as a potentially vast unstudied reservoir of resistance genes with possibilities to exchange with pathogens. Tetracycline resistance is one of the most abundant antibiotic resistances that may transfer among clinical and commensal microorganisms. To investigate tetracycline resistance genes from soil bacteria in different habitats, we performed functional analysis of three metagenomic libraries derived from soil samples collected from Yunnan, Sichuan, and Tibet, respectively, in China. We found efflux transporter genes form all the libraries, including 21 major facilitator superfamily efflux pump genes and one multidrug and toxic compound extrusion (MATE transporter gene. Interestingly, we also identified two tetracycline destructase genes, belonging to a newly described family of tetracycline-inactivating enzymes that scarcely observed in clinical pathogens, from the Tibet library. The inactivation activity of the putative enzyme was confirmed in vitro by biochemical analysis. Our results indicated that efflux pumps distributed predominantly across habitats. Meanwhile, the mechanism of enzymatic inactivation for tetracycline resistance should not be neglected and merits further investigation.

  8. Performance of Photocatalytic Oxidation of Tetracycline in Aqueous Solution by TiO2 Nanofibers

    Directory of Open Access Journals (Sweden)

    Allahbakhsh Javid

    2013-08-01

    Full Text Available The presence of pharmaceutical compounds in water and soil has become an environmental concern. The aim of this study was to evaluate the performance of TiO 2 nanofiber in the oxidation of the antibiotic tetracycline. TiO 2 nanofiber was fabricated by electro-spinning method, and then was calcined at 560?C for 2 h. Central composite design (CCD statistic model was used to optimize tetracycline concentration, time and pH for TiO 2 catalyst. A tubular Pyrex glass reactor with diameter of 15 cm and height of 30 cm was designed and a 125W Philips HPLN lamp (UV, ? > 254 nm was used as light source. Samples were measured by high-performance liquid chromatography (HPLC. Equation of model suggests a direct relationship between pH and time with efficiency of tetracycline removal. The observations indicated that time is the most significant (scaled estimate = + 28.04 parameter in efficiency of tetracycline removal. The application of response surface methodology yielded the equation of Y?=?65.82?+?5.74?pH?+?28.04 time?+?(?3.07(pH 2 ?+?(?6.6(time 2 , with R 2 = 0.986 which represents good reliability of model. Based on the response surface plots optimum conditions for degradation of tetracycline with maximum efficiency of around 95% was attained. These conditions are as follow; concentration: 50 mg/l, pH= 8.3, time= 15 min.

  9. Antibacterial Investigation of Thyme Essential Oil and Its Main Constituents in Combination with Tetracycline.

    Science.gov (United States)

    Miladinović, Dragoljub L; Ilić, Budimir S; Kocić, Branislava D; Ćirić, Vojislav M; Nikolić, Dejan M

    2015-08-01

    The chemical composition and antibacterial activity of Thymus glabrescens Willd. (thyme) essential oil were examined, as well as its association with tetracycline. The antibacterial activities of geraniol and thymol, the main constituents of T. glabrescens oil, were also determined. Gas chromatography and gas chromatography/mass spectrometry were used to analyze the chemical composition of the oil. The antibacterial activities of the oil, geraniol, and thymol were investigated by the broth microdilution method. The interactions of the essential oil, geraniol, and thymol with tetracycline, toward five selected strains, were evaluated using the microdilution checkerboard assay. Oxygenated monoterpenes were the most abundant compound class in the oil (57.14%), with geraniol (22.33%) as the major compound. The essential oil exhibited in vitro antibacterial activity against all tested bacterial strains. The combinations, essential oil-tetracycline and thymol-tetracycline, produced synergistic interaction to a greater extent compared with geraniol-tetracycline association. All synergistic combinations reduced the minimum effective dose of the antibiotic and, consequently, minimized its adverse side effects.

  10. The rarely reported tet(31) tetracycline resistance determinant is common in Gallibacterium anatis.

    Science.gov (United States)

    Bojesen, Anders M; Bager, Ragnhild J; Ifrah, Dan; Aarestrup, Frank M

    2011-05-05

    The present investigation was undertaken to identify and characterize the tetracycline resistance determinant in 22 Gallibacterium anatis strains for which no determinant was identified using primers specific for tet(A, B, C, D, E, G, H, K, L, M, O). A recent study found tet(B) to be the most prevalent tetracycline resistance determinant in a larger collection of G. anatis field strains from Mexico and Denmark. However, in 41% of the tetracycline resistant strains no determinant could be assigned. Here we demonstrate that tet(31) is a common determinant in G. anatis originating from chickens from very different production systems and localities. In addition, tet(31) was identified in strains isolated over a 30-year period. This is the first report on tet(31) since its original identification in Aeromonas salmonicida. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Use of radioisotopes in the study of tetracycline analytical application. Extraction of compounds formed between tetracycline and neptunium and americium elements

    International Nuclear Information System (INIS)

    Saiki, M.; Lima, F.W. de

    1986-01-01

    The behavior of tetracycline as complexing agent, in solvent extraction studies of neptunium and americium, using benzyl alcohol as the organic phase, is presented. By using radioactive tracers of 239 Np and 2 4 1 Am the extraction percent of these elements were determined as a function of pH in the absence and in the presence of several masking agents. The influence of shaking time and the use of different types of supporting eletrolytes upon the extraction behavior was also studied. The extraction curves obtained using EDTA as masking agent show that tetracycline can be used for neptunium and americium separation. In this condition neptunium is extracted into the organic phase and americium remains in the aqueous phase. (Author) [pt

  12. Cow excrements enhance the occurrence of tetracycline resistance genes in soil regardless of their oxytetracycline content

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Jirout, Jiří; Chroňáková, Alica; Vrchotová, Naděžda; Bradley, R.; Schmitt, H.; Elhottová, Dana

    2013-01-01

    Roč. 93, č. 10 (2013), s. 2413-2418 ISSN 0045-6535 R&D Projects: GA ČR GAP504/10/2077; GA MŠk(CZ) EE2.3.30.0032; GA MŠk(CZ) ED1.1.00/02.0073 Grant - others:OECD(FR) JA00054767 Institutional support: RVO:60077344 ; RVO:67179843 Keywords : cattle excrement * environmental risk assessment * manured soil * oxytetracycline * tetracycline resistance * tetracycline resistance gene Subject RIV: EE - Microbiology, Virology Impact factor: 3.499, year: 2013

  13. Susceptibilities of Eikenella corrodens, Prevotella intermedia, and Prevotella nigrescens Clinical Isolates to Amoxicillin and Tetracycline

    Science.gov (United States)

    Luong, N.; Tsai, J.; Chen, C.

    2001-01-01

    The AB Biodisk Etest showed that 106 (100%) and 98 (92%) isolates of Eikenella corrodens were susceptible to amoxicillin and tetracycline, respectively. Twenty-three (68%) Prevotella intermedia isolates and 14 (67%) Prevotella nigrescens isolates were susceptible to amoxicillin. Seventy-nine percent of the P. intermedia isolates and 67% of the P. nigrescens isolates were susceptible to tetracycline. A higher percentage of β-lactamase-producing isolates of P. intermedia and P. nigrescens were identified with selective agar containing amoxicillin than with nonselective agar. PMID:11600394

  14. Detection and Characterizations of Genes Resistant to Tetracycline and Sulfa among the Bacteria in Mariculture Water

    Science.gov (United States)

    Qu, L.; Li, Y.; Zhu, P.

    2013-12-01

    One hundred and thirty-five bacteria from maricultural environments were tested for sensitivity to tetracycline and sulfa. Result show that 72% of the bacteria were sulfa-resistant, 36% of the bacteria were tetracycline-resistant, and 16.5% of bacteria showed resistance to both tetracyclines and sulfa ,indicating that the proportion of sulfa and tetracycline resistance bacteria isvery large in the maricultural environments. PCR methods were used to detect if these resistant bacteria carry tetracycline and sulfa resistance genes. Out of the 33 tetracycline-resistant bacteria screened, 3 were positive for tetA, 6 were positive for tetB and no isolate wasboth positive for tetA and tetB. Of the 97 sulfa-resistant bacteria screened, 9 were positive for sul2, 6 were positive for sul1, 1 isolate was positive for bothsul1 and sul2. The minimum inhibitory concentration (MIC) of tetracycline for tetA-carrying isolates were higher than those tetB-carrying isolates.while The MIC of sulfa for sul2-carrying isolates were higher than those sul1-carrying isolates. Indicating that tetA and sul2 gene may play ubknown roles in resisting tetracycline and sulfa than tetB and sul1 genes. The results showed the 4 kinds of genes (tetA,tetB,sul1,sul2) has no host specificity. All these 16S sequence are from the isolates which are positive for the above genes, it indicated the above antibiotic resistance genes are widespread in the environment regardless of the host. While the DNA sequence of these four genes showed tetA, sul1, sul2 genes are conservative in different bacteria , etB gene conserved poorly. The research aim is to get a preliminary understanding of resistance mechanism related to the resistant bacteria and the resistance genes in marine aquaculture environment through the analysis of resistant genes, providing research base for the prevention and treatment of drug-resistant bacteria so as to reduce the threat to the ecological environment, aquaculture and human health.

  15. TetAB46, a predicted heterodimeric ABC transporter conferring tetracycline resistance in Streptococcus australis isolated from the oral cavity.

    Science.gov (United States)

    Warburton, Philip J; Ciric, Lena; Lerner, Avigdor; Seville, Lorna A; Roberts, Adam P; Mullany, Peter; Allan, Elaine

    2013-01-01

    To identify the genes responsible for tetracycline resistance in a strain of Streptococcus australis isolated from pooled saliva from healthy volunteers in France. S. australis is a viridans Streptococcus, originally isolated from the oral cavity of children in Australia, and subsequently reported in the lungs of cystic fibrosis patients and as a cause of invasive disease in an elderly patient. Agar containing 2 mg/L tetracycline was used for the isolation of tetracycline-resistant organisms. A genomic library in Escherichia coli was used to isolate the tetracycline resistance determinant. In-frame deletions and chromosomal repair were used to confirm function. Antibiotic susceptibility was determined by agar dilution and disc diffusion assay. The tetracycline resistance determinant from S. australis FRStet12 was isolated from a genomic library in E. coli and DNA sequencing showed two open reading frames predicted to encode proteins with similarity to multidrug resistance-type ABC transporters. Both genes were required for tetracycline resistance (to both the naturally occurring and semi-synthetic tetracyclines) and they were designated tetAB(46). This is the first report of a predicted ABC transporter conferring tetracycline resistance in a member of the oral microbiota.

  16. Study of the effect of gamma radiation on the molecule of tetracycline concerning its behavior as complexing and extracting agent

    International Nuclear Information System (INIS)

    Andrade e Silva, Leonardo Gondim de

    1982-01-01

    Both solvent extraction and spectrophotometric techniques were used to show the alterations that gamma radiation causes in the behavior of tetracycline molecule as far as its extracting and complexing power are concerned. The effect of gamma radiation on the solid tetracycline molecule, benzyl alcohol and on the solution of both was examined in solvent extraction systems whose aqueous phases were made up by 152 Eu- 154 Eu radioactive tracer solutions and whose organic phases were constituted by tetracycline-benzyl alcohol solutions. Experiments were performed in order to determine whether or not the water used for the pre-saturation of benzyl alcohol would influence the radiolysis of tetracycline. Solvent extraction and spectrophotometry were the techniques used to obtain the necessary data. Absorption spectra of irradiated tetracycline benzyl alcohol solutions submitted to several gamma radiation doses were examined and the alterations shown by these spectra were examined. The effect of gamma radiation on the tetracycline molecule was also studied when tetracycline-benzyl alcohol solutions were irradiated under several gaseous atmospheres, namely: O 2 , N 2 , SF 6 and N 2 O. The variation on the concentration of the tetracycline-benzyl alcohol solution caused by several doses of gamma radiation was determined by using the spectrophotometric technique. (author)

  17. Bismuth-Based Quadruple Therapy with Bismuth Subcitrate, Metronidazole, Tetracycline and Omeprazole in the Eradication of Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Raymond Lahaie

    2001-01-01

    Full Text Available BACKGROUND: A previous study showed that 14 days of qid bismuth-based triple therapy with tetracycline 500 mg, metronidazole 250 mg and colloidal bismuth subcitrate 120 mg resulted in excellent Helicobacter pylori eradication rates (89.5%. The present study looked at a shorter treatment period by adding omeprazole and by reducing the dose of tetracycline.

  18. Why relevance theory is relevant for lexicography

    DEFF Research Database (Denmark)

    Bothma, Theo; Tarp, Sven

    2014-01-01

    This article starts by providing a brief summary of relevance theory in information science in relation to the function theory of lexicography, explaining the different types of relevance, viz. objective system relevance and the subjective types of relevance, i.e. topical, cognitive, situational...... dictionary project, identifying new tasks and responsibilities of the modern lexicographer. The article furthermore discusses how relevance theory impacts on teaching dictionary culture and reference skills. By integrating insights from lexicography and information science, the article contributes to new...

  19. Chloramphenicol- and tetracycline-resistant uropathogenic Escherichia coli (UPEC) exhibit reduced virulence potential.

    Science.gov (United States)

    Starcic Erjavec, Marjanca; Rijavec, Matija; Krizan-Hergouth, Veronika; Fruth, Angelika; Zgur-Bertok, Darja

    2007-11-01

    It is well documented that uropathogenic Escherichia coli (UPEC) isolates resistant to nalidixic acid have reduced virulence potential. Our goal was to assess whether UPEC isolates resistant to chloramphenicol, tetracycline and streptomycin also exhibit reduced virulence potential. Among 110 human UPEC isolates, the prevalences of the virulence factors fimH, papC, papGII, papGIII, sfa/focDE, afa, hlyA, cnf1, usp, ibeA, fyuA, iroN, iucD, ireA, and K1 and K5 capsules as well as of pathotypes, phylogenetic groups, O antigens and a pathogenicity island (PAI) marker were compared between chloramphenicol-, tetracycline-, streptomycin- and, as a control, nalidixic acid-resistant and -susceptible strains. Our findings show that among human UPEC isolates, not only nalidixic acid-resistant but also chloramphenicol- and tetracycline-resistant isolates have reduced virulence potential compared with susceptible strains. To our knowledge, this is the first report of a statistically significant reduction in virulence traits among chloramphenicol- and tetracycline-resistant isolates.

  20. Determination of the stability constants for the complexes of rare-earth elements and tetracycline

    International Nuclear Information System (INIS)

    Saiki, M.; Lima, F.W.

    1977-01-01

    Stability constants for the lanthanide elements complexes with tetracycline were determined by the methods of average number of ligands, the two parameters and by weighted least squares. The technique of solvent extraction was applied to obtain the values of the parameters required for the determination of the constants [pt

  1. Membrane-active macromolecules resensitize NDM-1 gram-negative clinical isolates to tetracycline antibiotics.

    Directory of Open Access Journals (Sweden)

    Divakara S S M Uppu

    Full Text Available Gram-negative 'superbugs' such as New Delhi metallo-beta-lactamase-1 (blaNDM-1 producing pathogens have become world's major public health threats. Development of molecular strategies that can rehabilitate the 'old antibiotics' and halt the antibiotic resistance is a promising approach to target them. We report membrane-active macromolecules (MAMs that restore the antibacterial efficacy (enhancement by >80-1250 fold of tetracycline antibiotics towards blaNDM-1 Klebsiella pneumonia and blaNDM-1 Escherichia coli clinical isolates. Organismic studies showed that bacteria had an increased and faster uptake of tetracycline in the presence of MAMs which is attributed to the mechanism of re-sensitization. Moreover, bacteria did not develop resistance to MAMs and MAMs stalled the development of bacterial resistance to tetracycline. MAMs displayed membrane-active properties such as dissipation of membrane potential and membrane-permeabilization that enabled higher uptake of tetracycline in bacteria. In-vivo toxicity studies displayed good safety profiles and preliminary in-vivo antibacterial efficacy studies showed that mice treated with MAMs in combination with antibiotics had significantly decreased bacterial burden compared to the untreated mice. This report of re-instating the efficacy of the antibiotics towards blaNDM-1 pathogens using membrane-active molecules advocates their potential for synergistic co-delivery of antibiotics to combat Gram-negative superbugs.

  2. Bifunctional monomer magnetic imprinted nanomaterials for selective separation of tetracyclines directly from milk samples.

    Science.gov (United States)

    Xu, Yuan; Tang, Yuhai; Zhao, Yayun; Gao, Ruixia; Zhang, Junjie; Fu, Delai; Li, Zhaolun; Li, Hecheng; Tang, Xiaoshuang

    2018-04-01

    Novel magnetic molecularly imprinted nanomaterials (DA + BSA-MMIPs) were prepared adopting bovine serum albumin (BSA) and dopamine as bifunctional monomers for the first time. Besides the role of assistant functional monomer, BSA can exclude the proteins with like charges and promote low molecular weight tetracyclines to be adsorbed. Thus, the DA + BSA-MMIPs could fulfil the selective separation of tetracyclines directly from milk samples. The characteristics, polymerization conditions, and adsorption performances of the resultant nanomaterials were investigated in detail. In addition of uniform imprinting layers, stable crystalline phase, and good magnetism of the DA + BSA-MMIPs, they have rapid binding kinetic, high adsorption capacity, and favorable reusability. The imprinted nanomaterials were coupled with HPLC to selectively extract and determine trace tetracyclines from untreated milk samples. The recoveries of tetracyclines are in the range of 84.1-95.8% with relative standard deviations of less than 6.7%. The developed method is especially suitable for the selective enrichment and detection of target compounds directly from a complex sample with proteins. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Observations on the use of tetracycline and niacinamide as antipruritic agents in atopic dogs.

    Science.gov (United States)

    Beningo, K E; Scott, D W; Miller, W H; Rothstein, E

    1999-01-01

    Tetracycline and niacinamide were administered in combination to 19 atopic dogs to determine their effectiveness in controlling pruritus. The pruritus was controlled successfully in only one dog. One dog experienced diarrhea that was severe enough to warrant stopping the medication. PMID:10200886

  4. Tetracycline rapidly reaches all the constituent cells of uropathogenic Escherichia coli biofilms

    Science.gov (United States)

    Stone, G.; Wood, P.; Dixon, L.; Keyhan, M.; Matin, A.; Demain, A. L. (Principal Investigator)

    2002-01-01

    We have developed a method for visualizing Escherichia coli cells that are exposed to tetracycline in a biofilm, based on a previous report that liposomes containing the E. coli TetR(B) protein fluoresce when exposed to this antibiotic. By our method, cells devoid of TetR(B) also exhibited tetracycline-dependent fluorescence. At 50 microg of tetracycline ml(-1), planktonic cells of a uropathogenic E. coli (UPEC) strain developed maximal fluorescence after 7.5 to 10 min of exposure. A similar behavior was exhibited by cells in a 24- or 48-h UPEC biofilm, as examined by confocal laser microscopy, regardless of whether they lined empty spaces or occupied densely packed regions. Further, a comparison of phase-contrast and fluorescent images of corresponding biofilm zones showed that all the cells fluoresced. Thus, all the biofilm cells were exposed to tetracycline and there were no pockets within the biofilm where the antibiotic failed to reach. It also appeared unlikely that niches of reduced exposure to the antibiotic existed within the biofilms.

  5. Chemically modified tetracyclines stimulate matrix metalloproteinase-s production by periodontal ligament cells

    NARCIS (Netherlands)

    Bildt, M.M.; Snoek-van Beurden, A.M.P.; Groot, J. de; El, B. van; Kuijpers-Jagtman, A.M.; Hoff, J.W. van den

    2006-01-01

    Background and Objective: The purpose of this study was to investigate the effects of chemically modified tetracyclines (CMTs) on the production of gelatinases [matrix metalloproteinase (MMP)-2 and -9] by human periodontal ligament (PDL) cells, and on the activity of recombinant gelatinases.

  6. Adsorption and removal of tetracycline antibiotics from aqueous solution by graphene oxide.

    Science.gov (United States)

    Gao, Yuan; Li, Yan; Zhang, Liang; Huang, Hui; Hu, Junjie; Shah, Syed Mazhar; Su, Xingguang

    2012-02-15

    Significant concerns have been raised over pollution of antibiotics including tetracyclines in aquatic environments in recent years. Graphene oxide (GO) is a potential effective absorbent for tetracycline antibiotics and can be used to remove them from aqueous solution. Tetracycline strongly deposited on the GO surface via π-π interaction and cation-π bonding. The adsorption isotherm fits Langmuir and Temkin models well, and the theoretical maximum of adsorption capacity calculated by Langmuir model is 313 mg g(-1), which is approximately in a close agreement with the measured data. The kinetics of adsorption fits pseudo-second-order model perfectly, and it has a better rate constant of sorption (k), 0.065 g mg(-1) h(-1), than other adsorbents. The adsorption capacities of tetracycline on GO decreased with the increase in pH or Na(+) concentration. The adsorption isotherms of oxytetracycline and doxycycline on GO were discussed and compared. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

  7. Effects of ultraviolet light disinfection on tetracycline-resistant bacteria in wastewater effluents.

    Science.gov (United States)

    Childress, H; Sullivan, B; Kaur, J; Karthikeyan, R

    2014-09-01

    The ubiquitous use of antibiotics has led to an increasing number of antibiotic-resistant bacterial strains, including strains that are multidrug-resistant, pathogenic, or both. There is also evidence to suggest that antibiotic resistance genes (ARGs) spread to the environment, humans, and animals through wastewater effluents. The overall objective of this study was to investigate the effect of ultraviolet (UV) light disinfection on antibiotic-resistant bacteria. Wastewater effluent samples from a wastewater treatment plant (WWTP) in Texas were evaluated for differences in tetracycline-resistant bacteria before and after UV treatment. The effects of photoreactivation or dark repair on the reactivation of bacteria present in WWTP effluent after UV disinfection were also examined. Culture-based methods were used to characterize viable heterotrophic, tetracycline-resistant heterotrophic, Escherichia coli, and tetracycline-resistant E. coli bacteria present before and after UV treatment. UV disinfection was found to be as effective at reducing concentrations of resistant heterotrophs and E. coli, as it was at reducing total bacterial concentrations. The lowest survival ratio following UV disinfection was observed in tetracycline-resistant E. coli showing particular susceptibility to UV treatment. Photoreactivation and dark repair rates were found to be comparable to each other for all bacterial populations.

  8. Safety mechanism assisted by the repressor of tetracycline (SMART) vaccinia virus vectors for vaccines and therapeutics.

    Science.gov (United States)

    Grigg, Patricia; Titong, Allison; Jones, Leslie A; Yilma, Tilahun D; Verardi, Paulo H

    2013-09-17

    Replication-competent viruses, such as Vaccinia virus (VACV), are powerful tools for the development of oncolytic viral therapies and elicit superior immune responses when used as vaccine and immunotherapeutic vectors. However, severe complications from uncontrolled viral replication can occur, particularly in immunocompromised individuals or in those with other predisposing conditions. VACVs constitutively expressing interferon-γ (IFN-γ) replicate in cell culture indistinguishably from control viruses; however, they replicate in vivo to low or undetectable levels, and are rapidly cleared even in immunodeficient animals. In an effort to develop safe and highly effective replication-competent VACV vectors, we established a system to inducibly express IFN-γ. Our SMART (safety mechanism assisted by the repressor of tetracycline) vectors are designed to express the tetracycline repressor under a constitutive VACV promoter and IFN-γ under engineered tetracycline-inducible promoters. Immunodeficient SCID mice inoculated with VACVs not expressing IFN-γ demonstrated severe weight loss, whereas those given VACVs expressing IFN-γ under constitutive VACV promoters showed no signs of infection. Most importantly, mice inoculated with a VACV expressing the IFN-γ gene under an inducible promoter remained healthy in the presence of doxycycline, but exhibited severe weight loss in the absence of doxycycline. In this study, we developed a safety mechanism for VACV based on the conditional expression of IFN-γ under a tightly controlled tetracycline-inducible VACV promoter for use in vaccines and oncolytic cancer therapies.

  9. Inhibition of bacterial growth by tetracycline-impregnated enamel and dentin.

    Science.gov (United States)

    Bjorvatn, K; Skaug, N; Selvig, K A

    1984-12-01

    Tetracyclines can react with enamel and dentin to form relatively insoluble fluorescent compounds. The purpose of this study was to evaluate the possible antimicrobial effect of these reaction products on various microorganisms associated with human dental plaque and periodontal disease. Slabs of native dentin and enamel as well as demineralized dentin were immersed in aqueous solutions of tetracycline HCl, oxytetracycline HCl and doxycycline HCl for periods of 1 h or 24 h. Unimpregnated enamel and dentin slabs sterilized by gamma irradiation and specimens impregnated with phenoxymethylpenicillin calcium were used as controls. Test and control specimens were placed on agar plates seeded with B. cereus, C. ochraceus, S. sanguis, F. nucleatum, B. melaninogenicus or A. viscosus and were subsequently incubated aerobically or anaerobically at 37 degrees C. With the exception of enamel impregnated for 1 h in a 0.01 mg/ml tetracycline solution, all test specimens caused growth inhibition zones, varying in size according to concentration of the drug, immersion period and bacterial species. The results indicate that tetracyclines react with enamel and dentin to form slightly soluble compounds with a pronounced antibacterial effect. In comparison, the antimicrobial effect of dentin treated with penicillin was small.

  10. Tetracycline Resistance Genes in Campylobacter jejuni and C. coli Isolated From Poultry Carcasses.

    Science.gov (United States)

    Abdi-Hachesoo, Bahman; Khoshbakht, Rahem; Sharifiyazdi, Hassan; Tabatabaei, Mohammad; Hosseinzadeh, Saeid; Asasi, Keramat

    2014-09-01

    Campylobacter is one of the leading bacterial species causing foodborne illnesses in humans. Antimicrobial agents have been extensively used for treatment of Campylobacter infections; but in the recent years, both animal and human isolates of this bacterium have shown resistance to several antibiotics such as tetracycline. The aim of this study was to investigate the presence of genetic determinants of tetracycline resistance in Campylobacter spp. recovered from poultry carcasses in Shiraz, Iran. Eighty-three thermophilic Campylobacter spp. Isolates were first identified based on multiplex polymerase chain reaction (PCR) and then screened for presence of tetracycline resistance genes (tet (A), tet (B), tet (O) and te (S)) by PCR. The overall prevalence of Campylobacter jejuni and C. coli among the examined isolates was 51.8% and 48.2%, respectively. Tetracycline resistance genes of tet (B) and tet (S) were not seen among these Campylobacter spp. Isolates, whereas the most common tet gene identified was tet (O), found in 83.1% (69/83) of all the isolates. The tet (O) gene sequence comparison between C. jejuni and C. coli showed 100% similarity and these sequences (JX853721and JX853722) were also identical to the homologous sequences of other strains of Campylobacter spp. existing in the GenBank databases. In addition, tet (A) was found in 18% (15/83) of Campylobacter spp. isolates. To our knowledge, this represents the first report of tet (A) in Campylobacter spp. There was 100% homology between the sequences of tet (A) from this study (JX891463 and JX891464) and the tet (A) sequences mentioned for other bacteria in the GenBank databases. The high prevalence of tet (O) resistance gene along with new detection of tet (A) resistance gene in Campylobacter spp. isolated from poultry carcasses revealed an extensive tetracycline resistance among Campylobacter isolates from poultry in Iran. It emphasized the need for cautious use of tetracycline in poultry production to

  11. Removal of tetracycline from contaminated water by Moringa oleifera seed preparations.

    Science.gov (United States)

    Santos, Andréa F S; Matos, Maria; Sousa, Ângela; Costa, Cátia; Nogueira, Regina; Teixeira, José A; Paiva, Patrícia M G; Parpot, Pier; Coelho, Luana C B B; Brito, António G

    2016-01-01

    The aim of this study was to evaluate tetracycline antibiotic (TA) removal from contaminated water by Moringa oleifera seed preparations. The composition of synthetic water approximate river natural contaminated water and TA simulated its presence as an emerging pollutant. Interactions between TA and protein preparations (extract; fraction and lectin) were also evaluated. TA was determined by solid-phase extraction followed by high-performance liquid chromatography-mass spectrometry. Moringa extract and flour removed TA from water. The extract removed TA in all concentrations, and better removal (40%) was obtained with 40 mg L(-1); seed flour (particles  5 mm (0.50 g L(-1)) removed 55% of antibiotic. Interactions between TA and seed preparations were assayed by haemagglutinating activity (HA). Specific HA (SHA) of extract (pH 7) was abolished with tetracycline (5 mg L(-1)); fraction (75%) and lectin HA (97%) were inhibited with TA. Extract SHA decreased by 75% at pH 8. Zeta potential (ZP) of extract 700 mg L(-1) and tetracycline 50 mg L(-1) , pH range 5-8, showed different results. Extract ZP was more negative (-10.73 to -16.00 mV) than tetracycline ZP (-0.27 to -20.15 mV); ZP difference was greater in pH 8. The focus of this study was achieved since Moringa preparations removed TA from water and compounds interacting with tetracycline involved at least lectin-binding sites. This is a natural process, which do not promote environmental damage.

  12. TiO2-graphene sponge for the removal of tetracycline

    Science.gov (United States)

    Zhao, Lianqin; Xue, Fumin; Yu, Baowei; Xie, Jingru; Zhang, Xiaoliang; Wu, Ruihan; Wang, Ruijue; Hu, Zhiyan; Yang, Sheng-Tao; Luo, Jianbin

    2015-01-01

    Spongy graphene adsorbents have attracted great research interest recently, because of the high adsorption capacity, easy handling, and low operating cost. Fabrication of graphene sponge with other high-performance adsorbents might combine the merits of both materials, thus deserves more investigations. In this study, TiO2-graphene sponge (TiO2-GS) was prepared by the deposition of amorphous TiO2 on graphene oxide (GO) sheets for the adsorption of tetracycline antibiotics, where lyophilization was adopted to obtain the porous structure. TiO2-GS adsorbed tetracycline with a large adsorption capacity of 1,805 mg/g, larger than that of GO (313 mg/g) and GO-chitosan aerogel (1,470 mg/g). The adsorption kinetics, which finally reached the equilibrium at 48 h, was clearly controlled by the diffusion of tetracycline to TiO2-GS in the initial stage according to intraparticle diffusion model. Thermodynamics investigation indicated that the adsorption process was endothermic and promoted at higher temperature, with a positive Δ H of 35.8 kJ/mol. Generally, higher pH facilitated the adsorption of tetracycline on TiO2-GS, except that the adsorption was also very effective at pH 1. In contrast, ionic strength had insignificant influence. The adsorbed tetracycline could be washed out with acidic ice-cold water to regenerate TiO2-GS. The implication to the applications of TiO2-GS in water treatment is discussed.

  13. TiO{sub 2}–graphene sponge for the removal of tetracycline

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lianqin [Southwest University for Nationalities, College of Chemistry and Environment Protection Engineering (China); Xue, Fumin [Shandong Academy of Science, Shandong Provincial Analysis and Tester Center (China); Yu, Baowei; Xie, Jingru; Zhang, Xiaoliang; Wu, Ruihan; Wang, Ruijue; Hu, Zhiyan; Yang, Sheng-Tao, E-mail: yangst@pku.edu.cn; Luo, Jianbin, E-mail: luojb1971@163.com [Southwest University for Nationalities, College of Chemistry and Environment Protection Engineering (China)

    2015-01-15

    Spongy graphene adsorbents have attracted great research interest recently, because of the high adsorption capacity, easy handling, and low operating cost. Fabrication of graphene sponge with other high-performance adsorbents might combine the merits of both materials, thus deserves more investigations. In this study, TiO{sub 2}–graphene sponge (TiO{sub 2}–GS) was prepared by the deposition of amorphous TiO{sub 2} on graphene oxide (GO) sheets for the adsorption of tetracycline antibiotics, where lyophilization was adopted to obtain the porous structure. TiO{sub 2}–GS adsorbed tetracycline with a large adsorption capacity of 1,805 mg/g, larger than that of GO (313 mg/g) and GO-chitosan aerogel (1,470 mg/g). The adsorption kinetics, which finally reached the equilibrium at 48 h, was clearly controlled by the diffusion of tetracycline to TiO{sub 2}–GS in the initial stage according to intraparticle diffusion model. Thermodynamics investigation indicated that the adsorption process was endothermic and promoted at higher temperature, with a positive ΔH of 35.8 kJ/mol. Generally, higher pH facilitated the adsorption of tetracycline on TiO{sub 2}–GS, except that the adsorption was also very effective at pH 1. In contrast, ionic strength had insignificant influence. The adsorbed tetracycline could be washed out with acidic ice-cold water to regenerate TiO{sub 2}–GS. The implication to the applications of TiO{sub 2}–GS in water treatment is discussed.

  14. A Comprehensive Insight into Tetracycline Resistant Bacteria and Antibiotic Resistance Genes in Activated Sludge Using Next-Generation Sequencing

    Science.gov (United States)

    Huang, Kailong; Tang, Junying; Zhang, Xu-Xiang; Xu, Ke; Ren, Hongqiang

    2014-01-01

    In order to comprehensively investigate tetracycline resistance in activated sludge of sewage treatment plants, 454 pyrosequencing and Illumina high-throughput sequencing were used to detect potential tetracycline resistant bacteria (TRB) and antibiotic resistance genes (ARGs) in sludge cultured with different concentrations of tetracycline. Pyrosequencing of 16S rRNA gene revealed that tetracycline treatment greatly affected the bacterial community structure of the sludge. Nine genera consisting of Sulfuritalea, Armatimonas, Prosthecobacter, Hyphomicrobium, Azonexus, Longilinea, Paracoccus, Novosphingobium and Rhodobacter were identified as potential TRB in the sludge. Results of qPCR, molecular cloning and metagenomic analysis consistently indicated that tetracycline treatment could increase both the abundance and diversity of the tet genes, but decreased the occurrence and diversity of non-tetracycline ARG, especially sulfonamide resistance gene sul2. Cluster analysis showed that tetracycline treatment at subinhibitory concentrations (5 mg/L) was found to pose greater effects on the bacterial community composition, which may be responsible for the variations of the ARGs abundance. This study indicated that joint use of 454 pyrosequencing and Illumina high-throughput sequencing can be effectively used to explore ARB and ARGs in the environment, and future studies should include an in-depth investigation of the relationship between microbial community, ARGs and antibiotics in sewage treatment plant (STP) sludge. PMID:24905407

  15. A Comprehensive Insight into Tetracycline Resistant Bacteria and Antibiotic Resistance Genes in Activated Sludge Using Next-Generation Sequencing

    Directory of Open Access Journals (Sweden)

    Kailong Huang

    2014-06-01

    Full Text Available In order to comprehensively investigate tetracycline resistance in activated sludge of sewage treatment plants, 454 pyrosequencing and Illumina high-throughput sequencing were used to detect potential tetracycline resistant bacteria (TRB and antibiotic resistance genes (ARGs in sludge cultured with different concentrations of tetracycline. Pyrosequencing of 16S rRNA gene revealed that tetracycline treatment greatly affected the bacterial community structure of the sludge. Nine genera consisting of Sulfuritalea, Armatimonas, Prosthecobacter, Hyphomicrobium, Azonexus, Longilinea, Paracoccus, Novosphingobium and Rhodobacter were identified as potential TRB in the sludge. Results of qPCR, molecular cloning and metagenomic analysis consistently indicated that tetracycline treatment could increase both the abundance and diversity of the tet genes, but decreased the occurrence and diversity of non-tetracycline ARG, especially sulfonamide resistance gene sul2. Cluster analysis showed that tetracycline treatment at subinhibitory concentrations (5 mg/L was found to pose greater effects on the bacterial community composition, which may be responsible for the variations of the ARGs abundance. This study indicated that joint use of 454 pyrosequencing and Illumina high-throughput sequencing can be effectively used to explore ARB and ARGs in the environment, and future studies should include an in-depth investigation of the relationship between microbial community, ARGs and antibiotics in sewage treatment plant (STP sludge.

  16. A comprehensive insight into tetracycline resistant bacteria and antibiotic resistance genes in activated sludge using next-generation sequencing.

    Science.gov (United States)

    Huang, Kailong; Tang, Junying; Zhang, Xu-Xiang; Xu, Ke; Ren, Hongqiang

    2014-06-05

    In order to comprehensively investigate tetracycline resistance in activated sludge of sewage treatment plants, 454 pyrosequencing and Illumina high-throughput sequencing were used to detect potential tetracycline resistant bacteria (TRB) and antibiotic resistance genes (ARGs) in sludge cultured with different concentrations of tetracycline. Pyrosequencing of 16S rRNA gene revealed that tetracycline treatment greatly affected the bacterial community structure of the sludge. Nine genera consisting of Sulfuritalea, Armatimonas, Prosthecobacter, Hyphomicrobium, Azonexus, Longilinea, Paracoccus, Novosphingobium and Rhodobacter were identified as potential TRB in the sludge. Results of qPCR, molecular cloning and metagenomic analysis consistently indicated that tetracycline treatment could increase both the abundance and diversity of the tet genes, but decreased the occurrence and diversity of non-tetracycline ARG, especially sulfonamide resistance gene sul2. Cluster analysis showed that tetracycline treatment at subinhibitory concentrations (5 mg/L) was found to pose greater effects on the bacterial community composition, which may be responsible for the variations of the ARGs abundance. This study indicated that joint use of 454 pyrosequencing and Illumina high-throughput sequencing can be effectively used to explore ARB and ARGs in the environment, and future studies should include an in-depth investigation of the relationship between microbial community, ARGs and antibiotics in sewage treatment plant (STP) sludge.

  17. An in vitro study to assess the impact of tetracycline on the human intestinal microbiome.

    Science.gov (United States)

    Jung, Ji Young; Ahn, Youngbeom; Khare, Sangeeta; Gokulan, Kuppan; Piñeiro, Silvia A; Cerniglia, Carl E

    2018-02-01

    The human intestinal microbiome, a generally stable ecosystem, could be potentially altered by the ingestion of antimicrobial drug residues in foods derived from animals. Data and the scientific published literature on the effects of antimicrobial residues on the human intestinal microbiome are reviewed by national regulatory authorities as part of the human food safety evaluation of veterinary antimicrobial agents used in food-producing animals. In this study, we determined if tetracycline, at low residue concentrations, could impact the human intestinal microbiome structure and the resistance-gene profile, following acute and subchronic exposure. The effects of 0.15, 1.5, 15, and 150 μg/ml of tetracycline, after 24 h and 40 days of exposure, in 3% human fecal suspensions, collected from three individuals (A, B, and C) were investigated using in vitro batch cultures. Results were variable, with either no change or minor changes in total bacterial 16S rRNA gene copies after exposure of fecal samples to tetracycline, because of the inter-individual variation of human gastrointestinal tract microbiota. Bacterial community analysis using rRNA-based pyrosequencing revealed that Firmicutes and Bacteroidetes were the predominant phyla in the three fecal samples; the ratio of phylotypes varied among individuals. The evaluation of bacterial community changes at the genus level, from control to tetracycline-treated fecal samples, suggested that tetracycline under the conditions of this study could lead to slight differences in the composition of intestinal microbiota. The genus Bacteroides (of the Bacteroidetes) was consistently altered from 1.68 to 5.70% and 4.82-8.22% at tetracycline concentrations of 0.15 μg/ml or above at both time points for individual A, respectively, and increased 5.13-13.50% and 10.92-22.18% for individual B, respectively. Clostridium family XI increased 3.50-25.34% in the presence of tetracycline at 40 days for individual C. Principal

  18. Resistance to the tetracyclines and macrolide-lincosamide-streptogramin group of antibiotics and its genetic linkage - a review.

    Science.gov (United States)

    Marosevic, Durdica; Kaevska, Marija; Jaglic, Zoran

    2017-06-12

    An excessive use of antimicrobial agents poses a risk for the selection of resistant bacteria. Of particular interest are antibiotics that have large consumption rates in both veterinary and human medicine, such as the tetracyclines and macrolide-lincosamide-streptogramin (MLS) group of antibiotics. A high load of these agents increases the risk of transmission of resistant bacteria and/or resistance determinants to humans, leading to a subsequent therapeutic failure. An increasing incidence of bacteria resistant to both tetracyclines and MLS antibiotics has been recently observed. This review summarizes the current knowledge on different tetracycline and MLS resistance genes that can be linked together on transposable elements.

  19. Occurrence of tetracyclines in feedingstuffs – results of a two-year study within the official control of feed

    Directory of Open Access Journals (Sweden)

    Przeniosło-Siwczyńska Monika

    2015-12-01

    Full Text Available The paper describes a microbiological method for the detection of antibacterial substances in feedingstuffs. The method allowed detection of the main antibiotic groups, including tetracyclines. In 2013-2014, a total of 171 feed samples were analysed to determine antibacterial substances. Among the analysed samples 84 (49.1% were suspected to contain tetracyclines. Out of the 84 feeds analysed using chromatography, 28 (33.3% contained undeclared tetracyclines, which were identified at concentrations ranging from 0.32 mg kg-1 to 48.98 mg kg-1.

  20. To What Extent Is Mathematical Ability Predictive of Performance in a Methodology and Statistics Course? Can an Action Research Approach Be Used to Understand the Relevance of Mathematical Ability in Psychology Undergraduates?

    Science.gov (United States)

    Bourne, Victoria J.

    2014-01-01

    Research methods and statistical analysis is typically the least liked and most anxiety provoking aspect of a psychology undergraduate degree, in large part due to the mathematical component of the content. In this first cycle of a piece of action research, students' mathematical ability is examined in relation to their performance across…

  1. Distribution of tetracycline resistance genes in anaerobic treatment of waste sludge: The role of pH in regulating tetracycline resistant bacteria and horizontal gene transfer.

    Science.gov (United States)

    Huang, Haining; Chen, Yinguang; Zheng, Xiong; Su, Yinglong; Wan, Rui; Yang, Shouye

    2016-10-01

    Although pH value has been widely regarded as an important factor that affects resource recovery of waste sludge, the potential influence of diverse pHs on the distribution of tetracycline resistance genes (TRGs) during sludge anaerobic treatment is largely unknown. Here we reported that in the range of pH 4-10, 0.58-1.18 log unit increase of target TRGs was observed at pH 4, compared with that at pH 7, while 0.70-1.31 log unit further removal were obtained at pH 10. Mechanism study revealed that varied pHs not only altered the community structures of tetracycline resistant bacteria (TRB), but also changed their relative abundances, benefitting the propagation (acidic pHs) or attenuation (alkaline pHs) of TRB. Further investigation indicated that the amount and gene-possessing abilities of key genetic vectors for horizontal TRGs transfer were greatly promoted at acidic pHs but restricted under alkaline conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Mini-Mu insertions in the tetracycline resistance determinant from Proteus mirabilis

    Directory of Open Access Journals (Sweden)

    Magalhães V.D.

    1997-01-01

    Full Text Available The inducible tetracycline resistance determinant isolated from Proteus mirabilis cloned into the plasmid pACYC177 was mutagenized by insertion of a mini-Mu-lac phage in order to define the regions in the cloned sequences encoding the structural and regulatory proteins. Three different types of mutants were obtained: one lost the resistance phenotype and became Lac+; another expressed the resistance at lower levels and constitutively; the third was still dependent on induction but showed a lower minimal inhibitory concentration. The mutant phenotypes and the locations of the insertions indicate that the determinant is composed of a repressor gene and a structural gene which are not transcribed divergently as are other known tetracycline determinants isolated from Gram-negative bacteria

  3. An improved reprogrammable mouse model harbouring the reverse tetracycline-controlled transcriptional transactivator 3

    Directory of Open Access Journals (Sweden)

    S. Alaei

    2016-07-01

    Full Text Available Reprogrammable mouse models engineered to conditionally express Oct-4, Klf-4, Sox-2 and c-Myc (OKSM have been instrumental in dissecting molecular events underpinning the generation of induced pluripotent stem cells. However, until now these models have been reported in the context of the m2 reverse tetracycline-controlled transactivator, which results in low reprogramming efficiency and consequently limits the number of reprogramming intermediates that can be isolated for downstream profiling. Here, we describe an improved OKSM mouse model in the context of the reverse tetracycline-controlled transactivator 3 with enhanced reprogramming efficiency (>9-fold and increased numbers of reprogramming intermediate cells albeit with similar kinetics, which we believe will facilitate mechanistic studies of the reprogramming process.

  4. Tetracycline and niacinamide control bullous pemphigoid but not pemphigus foliaceus when these conditions coexist.

    Science.gov (United States)

    Shiohara, Junko; Yoshida, Kanako; Hasegawa, Junichi; Uhara, Hisashi; Takata, Minoru; Saida, Toshiaki; Ohyama, Bungo; Oyama, Bungo; Hashimoto, Takashi

    2010-07-01

    Pemphigus and pemphigoid are different types of autoimmune bullous disease and can occur in the same patient. We report a female patient with this condition. At first, we diagnosed her with bullous pemphigoid, and we treated her with tetracycline, niacinamide and a topical steroid. Tense bullas disappeared shortly after that, but crusted erythemas mainly on her head and trunk persisted. We examined BP180 and desmoglein 1 enzyme-linked immunosorbent assays, and also histological features, which showed coexistence of bullous pemphigoid and pemphigus foliaceus concurrently. Therefore, we tried prednisolone, which could control both conditions. This case showed that tetracycline and niacinamide could control bullous pemphigoid, but could not control pemphigus foliaceus, and that prednisolone was effective for both conditions.

  5. Antiepiligrin cicatricial pemphigoid of the larynx successfully treated with a combination of tetracycline and niacinamide.

    Science.gov (United States)

    Sakamoto, Kikuo; Mori, Kazunori; Hashimoto, Takashi; Yancey, Kim B; Nakashima, Tadashi

    2002-12-01

    A case of antiepiligrin cicatricial pemphigoid that primarily involved the larynx and required a tracheostomy was studied. The diagnosis was based on the direct immunofluorescence findings of a biopsy specimen from the glottis, immunofluorescence using normal and 1M sodium chloride-split normal human skin as substrates, and immunoprecipitation. A dramatic clinical improvement was observed after the combined administration of tetracycline hydrochloride and niacinamide. The tracheal stoma could be shut after the narrow segment was cut by means of carbon dioxide laser therapy. The patient showed no respiratory difficulty during the 2-year follow-up period. The combined therapy of tetracycline and niacinamide is thus considered to be an effective treatment for various types of cicatricial pemphigoid.

  6. Distribution and accumulative pattern of tetracyclines and sulfonamides in edible vegetables of cucumber, tomato, and lettuce.

    Science.gov (United States)

    Ahmed, Mohamed Bedair M; Rajapaksha, Anushka Upamali; Lim, Jung Eun; Vu, Ngoc Thang; Kim, Il Seop; Kang, Ho Min; Lee, Sang Soo; Ok, Yong Sik

    2015-01-21

    Veterinary antibiotics can be released to environment by the animals' excretions, which thereby poses human health and ecological risks. Six antibiotics (tetracycline, oxytetracycline, chlortetracycline, sulfamethazine, sulfamethoxazole, and sulfadimethoxine) at three concentrations (5, 10, and 20 mg kg(-1) soil) were employed in pots filled with a loamy sand upland soil. Three types of vegetable seedlings, including cucumber (Cucumis sativus), cherry tomato (Solanum lycopersicum), and lettuce (Lactuca sativa), were also cultivated during 45 d in the greenhouse. All antibiotics taken up by tested plants showed negative effects on growth. Relatively high levels of tetracyclines and sulfonamides (SAs) were detected in the nonedible parts, roots, and leaves of cucumber and tomato, but fruit parts accumulated them lower than acceptable daily intake. Indeed, cucumber roots accumulated SAs by up to 94.6% of total addition (at 5 mg kg(-1) soil).

  7. The Gut as Reservoir of Antibiotic Resistance: Microbial Diversity of Tetracycline Resistance in Mother and Infant

    DEFF Research Database (Denmark)

    de Vries, Lisbeth Elvira; Valles, Yvonne; Agersø, Yvonne

    2011-01-01

    The microbiota in the human gastrointestinal tract (GIT) is highly exposed to antibiotics, and may be an important reservoir of resistant strains and transferable resistance genes. Maternal GIT strains can be transmitted to the offspring, and resistances could be acquired from birth. This is a case...... study using a metagenomic approach to determine the diversity of microorganisms conferring tetracycline resistance (Tc-r) in the guts of a healthy mother-infant pair one month after childbirth, and to investigate the potential for horizontal transfer and maternal transmission of Tc-r genes. Fecal fosmid...... library, Tc-r was present exclusively in streptococci carrying tet(M), tet(L) and erm(T) within a novel composite transposon, Tn6079. This transposon belongs to a family of broad host range conjugative elements, implying a potential for the joint spread of tetracycline and erythromycin resistance within...

  8. An overview of the main foodstuff sample preparation technologies for tetracycline residue determination.

    Science.gov (United States)

    Pérez-Rodríguez, Michael; Pellerano, Roberto Gerardo; Pezza, Leonardo; Pezza, Helena Redigolo

    2018-05-15

    Tetracyclines are widely used for both the treatment and prevention of diseases in animals as well as for the promotion of rapid animal growth and weight gain. This practice may result in trace amounts of these drugs in products of animal origin, such as milk and eggs, posing serious risks to human health. The presence of tetracycline residues in foods can lead to the transmission of antibiotic-resistant pathogenic bacteria through the food chain. In order to ensure food safety and avoid exposure to these substances, national and international regulatory agencies have established tolerance levels for authorized veterinary drugs, including tetracycline antimicrobials. In view of that, numerous sensitive and specific methods have been developed for the quantification of these compounds in different food matrices. One will note, however, that the determination of trace residues in foods such as milk and eggs often requires extensive sample extraction and preparation prior to conducting instrumental analysis. Sample pretreatment is usually the most complicated step in the analytical process and covers both cleaning and pre-concentration. Optimal sample preparation can reduce analysis time and sources of error, enhance sensitivity, apart from enabling unequivocal identification, confirmation and quantification of target analytes. The development and implementation of more environmentally friendly analytical procedures, which involve the use of less hazardous solvents and smaller sample sizes compared to traditional methods, is a rapidly increasing trend in analytical chemistry. This review seeks to provide an updated overview of the main trends in sample preparation for the determination of tetracycline residues in foodstuffs. The applicability of several extraction and clean-up techniques employed in the analysis of foodstuffs, especially milk and egg samples, is also thoroughly discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Rosacea, Use of Tetracycline, and Risk of Incident Inflammatory Bowel Disease in Women.

    Science.gov (United States)

    Li, Wen-Qing; Cho, Eunyoung; Khalili, Hamed; Wu, Shaowei; Chan, Andrew T; Qureshi, Abrar A

    2016-02-01

    Rosacea is an inflammatory skin disease. Case reports have shown rosacea as a comorbidity of inflammatory bowel disease (IBD), but no epidemiologic studies have examined rosacea and risk of subsequent IBD. The association between tetracycline use and risk of IBD was assessed, but this study produced limited findings. We examined the association between rosacea, use of tetracycline, and risk of incident Crohn's disease (CD) and ulcerative colitis (UC). We analyzed data from 96,314 participants in the Nurses' Health Study II (1991-2011). Information on IBD was confirmed by medical review. Participants were asked in 2005 about their lifetime histories of clinician-diagnosed rosacea and year of diagnosis. Information on ever use of tetracycline was collected in 1993. During 1,856,587 person-years (1991-2011), we identified 149 cases of CD and 215 cases of UC. Rosacea was not associated with risk of UC. In contrast, rosacea was significantly associated with increased risk of subsequent CD (hazard ratio [HR], 2.20; 95% confidence interval [CI], 1.15-4.18), which appeared particularly stronger for a longer duration after a diagnosis of rosacea (Ptrend = .01). Tetracycline use was associated with increased risk of CD (HR, 1.56; 95% CI, 1.09-2.24) and UC (HR, 1.34; 95% CI, 1.00-1.80); there was a trend toward increased risk with increased duration of use (both Ptrend rosacea is associated with an increased risk of only CD. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

  10. RESIDUES OF TETRACYCLINES, SULFONAMIDES AND TYLOSIN IN JAR HONEY FROM LATIUM REGION DURING 2005-2007

    OpenAIRE

    G. Formato; S Saccares; G Migliore; L. De Santis; L. Lusco; C. Di Muro; P. Pulcini

    2008-01-01

    During 3 years (2005-2007), the IZSLT, and the C.R.A. (ex Sezione di Apicoltura dell’Istituto Sperimentale per la Zoologia Agraria – sede di Roma), analized 165 samples of jar honey, from Latium Region, for melissopalinological, sensorial, chemical and physical analysis. The screening test for tetracyclines and tylosin were performed, respectively, with the Tetrasensor Honey kit and the ELISA kit for tylosin. HPLC-ESI-MSMS was used for sulfonamides and for all the samples that res...

  11. "Tetracycline hydrochloride chemical burn" as self-inflicted mucogingival injury: A rare case report

    OpenAIRE

    Mundoor Manjunath Dayakar; Prakash G Pai; Sanupa S Madhavan

    2012-01-01

    Injuries to oral soft tissue can be accidental, iatrogenic, and factitious trauma. Chemical, thermal, and physical agents are the main causative agents for oral soft-tissue burns. The present case describes the chemical burn of oral mucosa caused by tetracycline hydrochloride and its management. Diagnosis was made on the basis of definitive history elicited from the patient. The early detection of the lesion by the patient and immediate institution of therapeutic measures ensure a rapid cure ...

  12. Factors influencing the survival and leaching of tetracycline-resistant bacteria and Escherichia coli through structured agricultural fields

    DEFF Research Database (Denmark)

    Bech, Tina Bundgaard; Rosenbom, Annette E.; Kjær, Jeanne

    2014-01-01

    Intense use of antibiotics in agricultural production may lead to the contamination of surface and groundwater by antibiotic-resistant bacteria. In the present study, the survival and leaching of E. coli and tetracycline-resistant bacteria were monitored at two well-structured agricultural fields....... Non-spiked pig slurry was injected in accordance with agricultural practice in the area. In both fields, the concentration of E. coli and tetracycline-resistant bacteria in the injected part of the plough layer decreased to the detection limit within 46–49 days. At Silstrup the decay was initiated...... with a lag phase and a decimal reduction time of 16 days for E. coli and 18 days for tetracycline-resistant bacteria. At Estrup the decay was immediate and the decimal reduction time was 22 days for E .coli and 26 days for tetracycline-resistant bacteria. Despite the two fields being prone to rapid...

  13. Fluorescence polarization of tetracycline derivatives as a technique for mapping nonmelanoma skin cancers.

    Science.gov (United States)

    Yaroslavsky, Anna N; Salomatina, Elena V; Neel, Victor; Anderson, Rox; Flotte, Thomas

    2007-01-01

    Nonmelanoma skin cancer is the most common form of human cancer, often resulting in high morbidity. Low visual contrast of these tumors makes their delineation a challenging problem. Employing a linearly polarized monochromatic light source and a wide-field CCD camera, we have developed a technique for fluorescence polarization imaging of the nonmelanoma cancers stained using antibiotics from the tetracycline family. To determine the feasibility of the method, fluorescence polarization images of 86 thick, fresh cancer excisions were studied. We found that the level of endogenous fluorescence polarization was much lower than that of exogenous, and that the average values of fluorescence polarization of tetracycline derivatives were significantly higher in cancerous as compared to normal tissue. Out of 86 tumors [54 stained in demeclocycline (DMN) and 32 in tetracycline (TCN)], in 79 cases (51-DMN, 28-TCN) the location, size, and shape of the lesions were identified accurately. The results of this trial indicate that nonmelanoma skin tumors can be distinguished from healthy tissue based on the differences in exogenous fluorescence polarization of TCN and/or DMN. Therefore, the developed technique can provide an important new tool for image-guided cancer surgery.

  14. Plasmid mediated tetracycline resistance of Vibrio parahaemolyticus associated with acute hepatopancreatic necrosis disease (AHPND in shrimps

    Directory of Open Access Journals (Sweden)

    Jee Eun Han

    2015-11-01

    Full Text Available Antimicrobial resistance is one of the most important problems in public health, veterinary medicine and aquaculture. Importantly, plasmid mediated antibiotic resistance of pathogenic Vibrio parahaemolyticus from shrimp can potentially be transferred through transposition, conjugation and plasmid uptake to different bacterial species in aquaculture systems. In this study, we evaluated the antibiotic resistance pattern in V. parahaemolyticus strains associated with acute hepatopancreatic necrosis disease (AHPND from penaeid shrimp and identified AHPND strains from Mexico showed a high level of resistance to tetracycline (≥5 μg/mL and have the tetB gene coding tetracycline resistance. In particular, the tetB gene was carried in a single copy plasmid (named as pTetB-VA1 comprising 5162-bp with 40% G + C content from the strain (13-511/A1. The plasmid pTetB-VA1 consists of 9 ORFs encoding tetracycline resistant and repressor proteins, transcriptional regulatory proteins and transposases and showed a 99% sequence identity to other tet gene plasmids (pIS04_68 and pAQU2.

  15. Hormetic effect(s) of tetracyclines as environmental contaminant on Zea mays

    Energy Technology Data Exchange (ETDEWEB)

    Migliore, Luciana; Godeas, Feliciana [Dipartimento di Biologia, Universita Tor Vergata, Rome (Italy); De Filippis, Stefania Paola [Istituto Superiore di Sanita, Toxicological Chemistry Unit, Rome (Italy); Mantovi, Paolo [Centro Ricerche Produzioni Animali, Reggio Emilia (Italy); Barchi, Davide [Assessorato all' Agricoltura, Regione Emilia-Romagna, Bologna (Italy); Testa, Cecilia; Rubattu, Nicolino [Istituto Zooprofilattico Sperimentale della Sardegna, Sassari (Italy); Brambilla, Gianfranco, E-mail: gianfranco.brambilla@iss.i [Istituto Superiore di Sanita, Toxicological Chemistry Unit, Rome (Italy)

    2010-01-15

    Animal wastes from intensive pig farming as fertilizers may expose crops to antimicrobials. Zea mays cultivations were carried out on a virgin field, subjected to dressing with pig slurries contaminated at 15 mg L{sup -1} of Oxy- and 5 mg L{sup -1} of Chlor-tetracycline, and at 8 mg L{sup -1} of Oxy and 3 mg L{sup -1} of Chlor, respectively. Pot cultivation was performed outdoor (Oxy in the range 62.5-1000 ng g{sup -1} dry soil) and plants harvested after 45 days. Tetracyclines analyses on soils and on field plants (roots, stalks, and leaves) did not determine the appreciable presence of tetracyclines. Residues were found in the 45-day pot corn only, in the range of 1-50 ng g{sup -1} for Oxy in roots, accounting for a 5% carry-over rate, on average. Although no detectable residues in plants from on land cultivations, both experimental batches showed the same biphasic growth form corresponding to a dose/response hormetic curve. - Oxytetracycline in soils elicits a hormetic response in Zea mays plants.

  16. Construction of a tetracycline inducible expression vector and characterization of its use in Vibrio cholerae.

    Science.gov (United States)

    Bina, X Renee; Wong, Eileen A; Bina, Thomas F; Bina, James E

    2014-11-01

    We report the construction of a tetracycline inducible expression vector that allows regulated gene expression in the enteric pathogen Vibrio cholerae. The expression vector, named pXB300, contains the tetracycline regulatory elements from Tn10, a multiple cloning site downstream of the tetA promoter and operator sequences, a ColE1 origin of replication, a β-lactamase resistance gene for positive selection, and the hok/sok addiction system for selection in the absence of antibiotic. The function of the tetracycline expression system was demonstrated by cloning lacZ under control of the tetA promoter and quantifying β-galactosidase expression in Escherichia coli and V. cholerae. The utility for pXB300 was documented by complementation of V. cholerae virulence mutants during growth under virulence inducing conditions. The results showed that pXB300 allowed high-level expression of recombinant genes with linear induction in response to the exogenous concentration of the inducer anhydrotetracycline. We further show that pXB300 was reliably maintained in V. cholerae during growth in the absence of antibiotic selection. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Classification Framework and Chemical Biology of Tetracycline-Structure-Based Drugs

    Directory of Open Access Journals (Sweden)

    Domenico Fuoco

    2012-06-01

    Full Text Available By studying the literature about tetracyclines (TCs, it becomes clearly evident that TCs are very dynamic molecules. In some cases, their structure-activity-relationship (SAR are well known, especially against bacteria, while against other targets, they are virtually unknown. In other diverse fields of research—such as neurology, oncology and virology—the utility and activity of the tetracyclines are being discovered and are also emerging as new technological fronts. The first aim of this paper is to classify the compounds already used in therapy and prepare the schematic structure that includes the next generation of TCs. The second aim of this work is to introduce a new framework for the classification of old and new TCs, using a medicinal chemistry approach to the structure of those drugs. A fully documented Structure-Activity-Relationship (SAR is presented with the analysis data of antibacterial and nonantibacterial (antifungal, antiviral and anticancer tetracyclines. The lipophilicity and the conformational interchangeability of the functional groups are employed to develop the rules for TC biological activity.

  18. In Vitro Antistaphylococcal Effects of Embelia schimperi Extracts and Their Component Embelin with Oxacillin and Tetracycline

    Directory of Open Access Journals (Sweden)

    Johana Rondevaldova

    2015-01-01

    Full Text Available Bacterial infections are in less-developed countries traditionally treated by remedies prepared from medicinal plants. Embelia schimperi (Vatke is a plant used as a taenicide or disinfectant in Ethiopia, very often taken mixed with another plant species. In the present study, we examined two extracts prepared from seeds and twigs with leaves of E. schimperi and its main present secondary metabolite embelin for their antibacterial combinatory effect with oxacillin and tetracycline against sensitive and resistant Staphylococcus aureus strains. Minimum inhibitory concentrations were determined through the broth microdilution method, whereas the combinatory effect was evaluated through fractional inhibitory concentration sum (ΣFIC indices. Results show many positive interactions and synergy occurring in embelin and oxacillin combinations against 4 out of 9 strains (ΣFIC 0.203–0.477 and for embelin and tetracycline combination against 3 out of 9 strains (ΣFIC 0.400–0.496. Moreover, the resistance to oxacillin has been overcome in 2 strains and to tetracycline in 3 strains. According to our knowledge, this is the first study showing antimicrobial combinatory effect of E. schimperi as well as of embelin. These findings can be used for the further research targeted on the development of new antistaphylococcal agents.

  19. Disposable amperometric magneto-immunosensor for direct detection of tetracyclines antibiotics residues in milk.

    Science.gov (United States)

    Conzuelo, Felipe; Gamella, María; Campuzano, Susana; Reviejo, A Julio; Pingarrón, José M

    2012-08-06

    The preparation and performance of a disposable amperometric magneto-immunosensor, involving the use of a selective capture antibody immobilized on the surface of protein G-functionalized magnetic beads (ProtG-MBs) and screen-printed carbon electrodes (SPCEs), for the specific detection and quantification of tetracyclines (TCs) residues in milk is reported. A direct competitive immunoassay using a tracer with horseradish peroxidase (HRP) for the enzymatic labeling was performed. The amperometric response measured at -0.2 V vs. the silver pseudo-reference electrode of the SPCE upon the addition of H(2)O(2) in the presence of hydroquinone (HQ) as redox mediator was used as transduction signal. The developed methodology showed very low limits of detection (in the low ppb level) for 4 tetracycline antibiotics tested in untreated milk samples, and a good selectivity against other antibiotic residues frequently detected in milk and dairy products. The usefulness of the magneto-immunosensor was demonstrated by analyzing UHT whole milk samples spiked with 44 ng mL(-1) tetracycline (TC) as well as a reference milk containing a certified oxytetracycline (OTC) content. These features, together with the short analysis time (30 min), the simplicity, and easy automation and miniaturization of the required instrumentation make the developed methodology a promising alternative in the development of devices for on-site analysis. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Correction: Membrane-active macromolecules resensitize NDM-1 gram-negative clinical isolates to tetracycline antibiotics.

    Directory of Open Access Journals (Sweden)

    Divakara S S M Uppu

    Full Text Available Gram-negative 'superbugs' such as New Delhi metallo-beta-lactamase-1 (blaNDM-1 producing pathogens have become world's major public health threats. Development of molecular strategies that can rehabilitate the 'old antibiotics' and halt the antibiotic resistance is a promising approach to target them. We report membrane-active macromolecules (MAMsthat restore the antibacterial efficacy (enhancement by >80-1250 fold of tetracycline antibiotics towards blaNDM-1 Klebsiella pneumonia and blaNDM-1 Escherichia coli clinical isolates.Organismic studies showed that bacteria had an increased and faster uptake of tetracyclinein the presence of MAMs which is attributed to the mechanism of re-sensitization. Moreover,bacteria did not develop resistance to MAMs and MAMs stalled the development of bacterial resistance to tetracycline. MAMs displayed membrane-active properties such as dissipation of membrane potential and membrane-permeabilization that enabled higher uptake of tetracycline in bacteria. In-vivo toxicity studies displayed good safety profiles and preliminary in-vivo antibacterial efficacy studies showed that mice treated with MAMs in combination with antibiotics had significantly decreased bacterial burden compared to the untreated mice. This report of re-instating the efficacy of the antibiotics towards blaNDM-1 pathogens using membrane-active molecules advocates their potential for synergistic co-delivery of antibiotics to combat Gram-negative superbugs.

  1. Electrochemical oxidation of drug residues in water by the example of tetracycline, gentamicin and Aspirin {sup trademark}

    Energy Technology Data Exchange (ETDEWEB)

    Weichgrebe, D.; Danilova, E.; Rosenwinkel, K.H. [Inst. of Water Quality and Waste Management, Univ. of Hannover, Hannover (Germany); Vedenjapin, A.; Baturova, M. [Inst. of Organic Chemistry, Russian Academy of Science, Moscow (Russian Federation)

    2003-07-01

    The electrochemical oxidation as a method to destroy drug residues like Aspirin {sup trademark}, tetracycline or gentamicin in water was investigated with C-Anode (modified by manganese oxides) and Pt Anode. The mechanism of Aspirin {sup trademark} and tetracycline oxidation and the influence of the biocide effect was observed using GC-MS and three different microbiological tests. In general the biological availability increases with progressive oxidation of the antibiotics. (orig.)

  2. Development and validation of a sensitive method for tetracycline in gingival crevicular fluid by HPLC using fluorescence detection.

    Science.gov (United States)

    Vienneau, D S; Kindberg, C G

    1997-09-01

    Increased interest in the clinical use of antibiotics for periodontal therapy required the development of a sensitive assay for the quantitation of tetracycline in gingival crevicular fluid (GCF). An HPLC method was developed and validated for tetracycline which separates and identifies the degradation component epi-tetracycline. The HPLC assay employs a C18 reversed-phase Hypersil column with a mobile phase composed of methanol and sodium acetate buffer containing CaCl2 and EDTA disodium salt. The chromatographic separation was monitored by a fluorescent detector with an excitation wavelength of 375 nm and an emission wavelength of 512 nm. Tetracycline was extracted from GCF collected on Periopapers by addition of a methanol solution containing the internal standard, doxycycline, and the mobile phase buffer (25:75, v/v). The mean percent recovery for the extraction method was 107.8% with all the % R.S.D. below 7.5%. The mean inter- and intra-batch accuracy was 104.1 and 105.3%, respectively with a coefficient of variation of less than 9.5%. The lower limit of detection was 2.5 ng on the Periopapers. The typical GCF volumes collected were 0.1-1 microliter. The method was validated for the linear concentration range 2.5-1000 ng of tetracycline on the Periopaper. This assay for tetracycline was shown to be an accurate, precise and rugged method.

  3. Removal mechanisms and kinetics of trace tetracycline by two types of activated sludge treating freshwater sewage and saline sewage.

    Science.gov (United States)

    Li, Bing; Zhang, Tong

    2013-05-01

    Understanding the removal mechanisms and kinetics of trace tetracycline by activated sludge is critical to both evaluation of tetracycline elimination in sewage treatment plants and risk assessment/management of tetracycline released to soil environment due to the application of biosolids as fertilizer. Adsorption is found to be the primary removal mechanism while biodegradation, volatilization, and hydrolysis can be ignored in this study. Adsorption kinetics was well described by pseudo-second-order model. Faster adsorption rate (k₂ = 2.04 × 10(-2) g min(-1) μg(-1)) and greater adsorption capacity (qe = 38.8 μg g(-1)) were found in activated sludge treating freshwater sewage. Different adsorption rate and adsorption capacity resulted from chemical properties of sewage matrix rather than activated sludge surface characteristics. The decrease of tetracycline adsorption in saline sewage was mainly due to Mg(2+) which significantly reduced adsorption distribution coefficient (Kd) from 12,990 ± 260 to 4,690 ± 180 L kg(-1). Species-specific adsorption distribution coefficients followed the order of Kd⁺⁰⁰>Kd⁺⁻⁰>Kd⁺⁻⁻. Contribution of zwitterionic tetracycline to the overall adsorption was >90 % in the actual pH range in aeration tank. Adsorption of tetracycline in a wide range of temperature (10 to 35 °C) followed the Freundlich adsorption isotherm well.

  4. Spectroscopic studies of europium-tetracyclines complexes and their applications in detection of hydrogen peroxide and urea peroxide

    International Nuclear Information System (INIS)

    Grasso, Andrea Nastri

    2010-01-01

    In this work were studied the spectroscopic properties of trivalent europium ion complexed with components of tetracycline family, chlorotetracycline, oxytetracycline and metacycline, in the presence of hydrogen peroxide and urea peroxide. Optical parameters were obtained such as absorption, emission, lifetime and calibration curves were constructed for luminescence spectra. Experiments were carried out with both inorganic compounds and europium-tetracyclines complexes in order to verify possible interferences. Studies for glucose determination were also described using europium-tetracyclines complexes as biosensors. Results show that europium tetracyclines complexes emit a narrow band in the visible region and, in the presence of hydrogen peroxide or urea peroxide there is a greater enhancement in their luminescence and lifetime. Thus, europium-tetracyclines complexes studied can be used as biosensors for hydrogen and urea peroxides determination as a low cost and room temperature method. An indirect method for glucose determination was studied by adding glucose oxidase enzyme in europium-tetracyclines complex in the presence of glucose promoting as product hydrogen peroxide. (author)

  5. Intralesional tetracycline injection for treatment of lower eyelid festoons: a preliminary report.

    Science.gov (United States)

    Perry, Julian D; Mehta, Viraj J; Costin, Bryan R

    2015-01-01

    To determine the safety and effectiveness of intralesional tetracycline 2% injection for the treatment of lower eyelid festoons. The authors retrospectively reviewed the charts of all patients undergoing tetracycline 2% injection of lower eyelid festoons at the Cole Eye Institute from August 2008 to August 2013. Charts were reviewed for patient demographic data, dose and number of tetracycline injections, follow-up interval, the presence of preinjection and postinjection photographs, and complications. Charts without preinjection and postinjection photographs were excluded from review. The preinjection and postinjection photographs were randomized, masked, and graded by 4 independent examiners. Photographs were graded on a scale of 0 (no festoon) to 4 (severe festoon). Student t test was used for statistical analysis. Eleven patients met inclusion criteria. Each patient underwent bilateral injection. Average follow up was 121 days (range, 18-586 days). Patients received up to 0.75 ml (mean, 0.24 ml) of tetracycline 2% per side. Average preinjection grade was 2.1 (standard deviation, 0.89; range, 0-3), and average postinjection grade was 1.2 (standard deviation, 0.72; range, 0-2; p < 0.001). Three patients had follow up less than 60 days (mean, 34 days), with an average preinjection grade of 1.96 and postinjection grade of 1.23 (p < 0.001). Five patients had follow up between 60 and 100 days (mean, 82 days), with an average preinjection grade of 2.18 and postinjection grade of 1.38 (p < 0.001). Three patients had follow up longer than 100 days (mean, 275 days), with an average preinjection grade of 2.08 and postinjection grade of 0.78 (p < 0.001). Complications other than pain and bruising were not identified in any patient. Intralesional tetracycline 2% injection may offer a safe option to treat lower eyelid festoons. Complications such as cutaneous ischemia or necrosis were not identified in any patient. Further study may determine optimal treatment doses and

  6. Direct screening of tetracyclines in water and bovine milk using room temperature phosphorescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Traviesa-Alvarez, J.M. [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julian Claveria 8, 33006 Oviedo (Spain); Costa-Fernandez, J.M. [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julian Claveria 8, 33006 Oviedo (Spain); Pereiro, R. [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julian Claveria 8, 33006 Oviedo (Spain); Sanz-Medel, A. [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julian Claveria 8, 33006 Oviedo (Spain)]. E-mail: asm@uniovi.es

    2007-04-18

    A fast and simple flow-through optosensor was designed and characterized for the direct screening of four tetracycline (TCC) antibiotics (tetracycline, oxytetracycline, chlortetracycline and doxycycline) in water and bovine milk samples. The proposed optosensor provides rapid binary yes/no overall responses, being appropriate for the screening of this family of antibiotics above or below a pre-set concentration threshold. The experimental set-up is based on a flow-injection manifold coupled on-line to a phosphorescence detector. Aliquots of the samples are pretreated with Eu(III) to form room temperature phosphorescent metal chelates and injected in the flow manifold. Those chelates are then on-line retained on a conventional flow-cell (packed with polymeric Amberlite XAD-4 particles) which is placed inside the cell holder of the phosphorimeter. After the emission is registered, the antibiotic-metal complexes are eluted from the packed resin with 1 M HCl (for milk samples a second regeneration step, using methanol, should be performed). A sample throughput of about 20 samples per hour was obtained. Optimum experimental conditions include a pH 9, a Eu(III) concentration of 2 x 10{sup -4} M and 8 mM sodium sulphite as chemical deoxygenant. The phosphorescence emitted by the europium-TCC complexes was measured at 394 and 617 nm for excitation and emission wavelengths, respectively. The unreliability region, given by the probability of false positives and false negatives, respectively (set at 5% in both cases) was in the range between 0.2 and 11.6 nM for detection of tetracyclines in water samples (at a cut-off level of 4 nM) and in the range between 165 and 238 nM for detection of tetracyclines in milk (cut-off level fixed at the normative EU level of 200 nM). Finally, the applicability of the proposed screening optosensor was tested for the reliable control of tetracyclines in contaminated and uncontaminated water and milk samples.

  7. Direct screening of tetracyclines in water and bovine milk using room temperature phosphorescence detection.

    Science.gov (United States)

    Traviesa-Alvarez, J M; Costa-Fernández, J M; Pereiro, R; Sanz-Medel, A

    2007-04-18

    A fast and simple flow-through optosensor was designed and characterized for the direct screening of four tetracycline (TCC) antibiotics (tetracycline, oxytetracycline, chlortetracycline and doxycycline) in water and bovine milk samples. The proposed optosensor provides rapid binary yes/no overall responses, being appropriate for the screening of this family of antibiotics above or below a pre-set concentration threshold. The experimental set-up is based on a flow-injection manifold coupled on-line to a phosphorescence detector. Aliquots of the samples are pretreated with Eu(III) to form room temperature phosphorescent metal chelates and injected in the flow manifold. Those chelates are then on-line retained on a conventional flow-cell (packed with polymeric Amberlite XAD-4 particles) which is placed inside the cell holder of the phosphorimeter. After the emission is registered, the antibiotic-metal complexes are eluted from the packed resin with 1M HCl (for milk samples a second regeneration step, using methanol, should be performed). A sample throughput of about 20 samples per hour was obtained. Optimum experimental conditions include a pH 9, a Eu(III) concentration of 2 x 10(-4) M and 8 mM sodium sulphite as chemical deoxygenant. The phosphorescence emitted by the europium-TCC complexes was measured at 394 and 617 nm for excitation and emission wavelengths, respectively. The unreliability region, given by the probability of false positives and false negatives, respectively (set at 5% in both cases) was in the range between 0.2 and 11.6 nM for detection of tetracyclines in water samples (at a cut-off level of 4 nM) and in the range between 165 and 238 nM for detection of tetracyclines in milk (cut-off level fixed at the normative EU level of 200 nM). Finally, the applicability of the proposed screening optosensor was tested for the reliable control of tetracyclines in contaminated and uncontaminated water and milk samples.

  8. Quantitative proteome analysis of an antibiotic resistant Escherichia coli exposed to tetracycline reveals multiple affected metabolic and peptidoglycan processes.

    Science.gov (United States)

    Jones-Dias, Daniela; Carvalho, Ana Sofia; Moura, Inês Barata; Manageiro, Vera; Igrejas, Gilberto; Caniça, Manuela; Matthiesen, Rune

    2017-03-06

    Tetracyclines are among the most commonly used antibiotics administrated to farm animals for disease treatment and prevention, contributing to the worldwide increase in antibiotic resistance in animal and human pathogens. Although tetracycline mechanisms of resistance are well known, the role of metabolism in bacterial reaction to antibiotic stress is still an important assignment and could contribute to the understanding of tetracycline related stress response. In this study, spectral counts-based label free quantitative proteomics has been applied to study the response to tetracycline of the environmental-borne Escherichia coli EcAmb278 isolate soluble proteome. A total of 1484 proteins were identified by high resolution mass spectrometry at a false discovery rate threshold of 1%, of which 108 were uniquely identified under absence of tetracycline whereas 126 were uniquely identified in presence of tetracycline. These proteins revealed interesting difference in e.g. proteins involved in peptidoglycan-based cell wall proteins and energy metabolism. Upon treatment, 12 proteins were differentially regulated showing more than 2-fold change and pcoli provides novel insight into tetracycline related stress. The lack of new antibiotics to fight infections caused by multidrug resistant microorganisms has motivated the use of old antibiotics, and the search for new drug targets. The evolution of antibiotic resistance is complex, but it is known that agroecosystems play an important part in the selection of antibiotic resistance bacteria. Tetracyclines are still used as phytopharmaceutical agents in crops, selecting resistant bacteria and changing the ecology of farm soil. Little is known about the metabolic response of genetically resistant populations to antibiotic exposure. Indeed, to date there are no quantitative tetracycline resistance studies performed with the latest generation of high resolution mass spectrometers allowing high mass accuracy in both MS and MS

  9. Territories climate plans: territories in action 21 collectivities involved in the climatic change challenge. 1. experiences collection 2007; Plans climat territoriaux: des territoires en action 21 collectivites engagees dans la releve du defi climatique. 1. recueil d'experiences 2007

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The climate plan invites the collectivities to implement actions of greenhouse reduction. This collection presents the first collectivities involved in a climate approach: towns, natural parks, syndicates, general and regional council. (A.L.B.)

  10. Conditional and inducible transgene expression in endothelial and hematopoietic cells using Cre/loxP and tetracycline-off systems.

    Science.gov (United States)

    Liu, Ju; Deutsch, Urban; Fung, Iris; Lobe, Corrinne G

    2014-11-01

    In the present study, the tetracycline-off and Cre/ loxP systems were combined to gain temporal and spatial control of transgene expression. Mice were generated that carried three transgenes: Tie2-tTA, tet-O-Cre and either the ZEG or ZAP reporter. Tie2-tTA directs expression of tetracycline-controlled transactivator (tTA) in endothelial and hematopoietic cells under the control of the Tie2 promoter. Tet-O-Cre produces Cre recombinase from a minimal promoter containing the tet-operator (tetO). ZEG or ZAP contains a strong promoter and a loxP -flanked stop sequence, followed by an enhanced green fluorescence protein (EGFP) or human placental alkaline phosphatase (hPLAP) reporter. In the presence of tetracycline, the tTA transactivator produced by Tie-2-tTA is disabled and Cre is not expressed. In the absence of tetracycline, the tTA binds tet-O-Cre to drive the expression of Cre, which recombines the loxP sites of the ZEG or ZAP transgene and results in reporter gene expression. In the present study, the expression of the ZEG or ZAP reporter genes in embryos and adult animals with and without tetracycline treatment was examined. In the presence of tetracycline, no reporter gene expression was observed. When tetracycline was withdrawn, Cre excision was activated and the reporter genes were detected in endothelial and hematopoietic cells. These results demonstrate that this system may be used to bypass embryonic lethality and access adult phenotypes.

  11. Emergence of Tetracycline Resistance in Helicobacter pylori: Multiple Mutational Changes in 16S Ribosomal DNA and Other Genetic Loci

    Science.gov (United States)

    Dailidiene, Daiva; Bertoli, M. Teresita; Miciuleviciene, Jolanta; Mukhopadhyay, Asish K.; Dailide, Giedrius; Pascasio, Mario Alberto; Kupcinskas, Limas; Berg, Douglas E.

    2002-01-01

    Tetracycline is useful in combination therapies against the gastric pathogen Helicobacter pylori. We found 6 tetracycline-resistant (Tetr) strains among 159 clinical isolates (from El Salvador, Lithuania, and India) and obtained the following four results: (i) 5 of 6 Tetr isolates contained one or two nucleotide substitutions in one part of the primary tetracycline binding site in 16S rRNA (AGA965-967 [Escherichia coli coordinates] changed to gGA, AGc, guA, or gGc [lowercase letters are used to represent the base changes]), whereas the sixth (isolate Ind75) retained AGA965-967; (ii) PCR products containing mutant 16S ribosomal DNA (rDNA) alleles transformed recipient strains to Tetr phenotypes, but transformants containing alleles with single substitutions (gGA and AGc) were less resistant than their Tetr parents; (iii) each of 10 Tetr mutants of reference strain 26695 (in which mutations were induced with metronidazole, a mutagenic anti-H. pylori agent) contained the normal AGA965-967 sequence; and (iv) transformant derivatives of Ind75 and of one of the Tetr 26695 mutants that had acquired mutant rDNA alleles were resistant to tetracycline at levels higher than those to which either parent strain was resistant. Thus, tetracycline resistance in H. pylori results from an accumulation of changes that may affect tetracycline-ribosome affinity and/or other functions (perhaps porins or efflux pumps). We suggest that the rarity of tetracycline resistance among clinical isolates reflects this need for multiple mutations and perhaps also the deleterious effects of such mutations on fitness. Formally equivalent mutations with small but additive effects are postulated to contribute importantly to traits such as host specificity and virulence and to H. pylori's great genetic diversity. PMID:12435699

  12. UV light tolerance and reactivation potential of tetracycline-resistant bacteria from secondary effluents of a wastewater treatment plant.

    Science.gov (United States)

    Huang, Jing-Jing; Xi, Jinying; Hu, Hong-Ying; Li, Yi; Lu, Sun-Qin; Tang, Fang; Pang, Yu-Chen

    2016-03-01

    Tetracycline-resistant bacteria (TRB) are of concern as emerging microbial contaminants in reclaimed water. To understand the effects of UV disinfection on TRB, both inactivation and reactivation profiles of TRB, as well as 16 tetracycline-resistant isolates from secondary effluent, were characterized in this study. The inactivation ratio of TRB was significantly lower (3.0-log) than that of heterotrophic bacteria (>4.0-log) in the secondary effluent. Additionally, the proportion of TRB significantly increased from 1.65% to 15.51% under 20mJ/cm(2) ultraviolet (UV) exposure. The inactivation rates of tetracycline-resistant isolates ranged from 0.57/s to 1.04/s, of which tetracycline-resistant Enterobacter-1 was the most tolerant to UV light. The reactivation of TRB, tetracycline-resistant isolated strains, as well as heterotrophic bacteria commonly occurred in the secondary effluent even after 20mJ/cm(2) UV exposure. The colony forming ability of TRB and heterotrophic bacteria reached 3.2-log and 3.0-log under 20mJ/cm(2) UV exposure after 22hr incubation. The final inactivation ratio of tetracycline-resistant Enterobacter-1 was 1.18-log under 20mJ/cm(2) UV exposure after 22hr incubation, which is similar to those of TRB (1.18-log) and heterotrophic bacteria (1.19-log). The increased proportion of TRB and the reactivation of tetracycline-resistant enterobacteria in reclaimed water could induce a microbial health risk during wastewater reuse. Copyright © 2015. Published by Elsevier B.V.

  13. Sensitivity to communicative relevance tells young children what to imitate.

    Science.gov (United States)

    Southgate, Victoria; Chevallier, Coralie; Csibra, Gergely

    2009-11-01

    How do children decide which elements of an action demonstration are important to reproduce in the context of an imitation game? We tested whether selective imitation of a demonstrator's actions may be based on the same search for relevance that drives adult interpretation of ostensive communication. Three groups of 18-month-old infants were shown a toy animal either hopping or sliding (action style) into a toy house (action outcome), but the communicative relevance of the action style differed depending on the group. For the no prior information group, all the information in the demonstration was new and so equally relevant. However, for infants in the ostensive prior information group, the potential action outcome was already communicated to the infant prior to the main demonstration, rendering the action style more relevant. Infants in the ostensive prior information group imitated the action style significantly more than infants in the no prior information group, suggesting that the relevance manipulation modulated their interpretation of the action demonstration. A further condition (non-ostensive prior information) confirmed that this sensitivity to new information is only present when the 'old' information had been communicated, and not when infants discovered this information for themselves. These results indicate that, like adults, human infants expect communication to contain relevant content, and imitate action elements that, relative to their current knowledge state or to the common ground with the demonstrator, is identified as most relevant.

  14. Single protein omission reconstitution studies of tetracycline binding to the 30S subunit of Escherichia coli ribosomes

    International Nuclear Information System (INIS)

    Buck, M.; Cooperman, B.S.

    1990-01-01

    In previous work the authors showed that on photolysis of Escherichia coli ribosomes in the presence of [ 3 H]tetracycline (TC) the major protein labeled is S7, and they presented strong evidence that such labeling takes place from a high-affinity site related to the inhibitory action of TC. In this work they use single protein omission reconstitution (SPORE) experiments to identify those proteins that are important for high-affinity TC binding to the 30S subunit, as measured by both cosedimentation and filter binding assays. With respect to both sedimentation coefficients and relative Phe-tRNA Phe binding, the properties of the SPORE particles they obtain parallel very closely those measured earlier, with the exception of the SPORE particle lacking S13. A total of five proteins, S3, S7, S8, S14, and S19, are shown to be important for TC binding, with the largest effects seen on omission of proteins S7 and S14. Determination of the protein compositions of the corresponding SPORE particles demonstrates that the observed effects are, for the most part, directly attributable to the omission of the given protein rather than reflecting an indirect effect of omitting one protein on the uptake of another. A large body of evidence supports the notion that four of these proteins, S3, S7, S14, and S19, are included, along with 16S rRNA bases 920-1,396, in one of the major domains of the 30S subunit. The results support the conclusion that the structure of this domain is important for the binding of TC and that, within this domain, TC binds directly to S7

  15. Effect of Tetracycline Dose and Treatment Mode on Selection of Resistant Coliform Bacteria in Nursery Pigs.

    Science.gov (United States)

    Græsbøll, Kaare; Damborg, Peter; Mellerup, Anders; Herrero-Fresno, Ana; Larsen, Inge; Holm, Anders; Nielsen, Jens Peter; Christiansen, Lasse Engbo; Angen, Øystein; Ahmed, Shahana; Folkesson, Anders; Olsen, John Elmerdahl

    2017-06-15

    This study describes the results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on the selection of antibiotic-resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4 to 7 weeks of age) in five pig herds were treated with oxytetracycline for Lawsonia intracellularis -induced diarrhea. Each group was randomly allocated to one of five treatment groups: oral flock treatment with a (i) high (20 mg/kg of body weight), (ii) medium (10 mg/kg), or (iii) low (5 mg/kg) dose, (iv) oral pen-wise (small-group) treatment (10 mg/kg), and (v) individual intramuscular injection treatment (10 mg/kg). All groups were treated once a day for 5 days. In all groups, treatment caused a rise in the numbers and proportions of tetracycline-resistant coliform bacteria right after treatment, followed by a significant drop by the time that the pigs left the nursery unit. The counts and proportions of tetracycline-resistant coliforms did not vary significantly between treatment groups, except immediately after treatment, when the highest treatment dose resulted in the highest number of resistant coliforms. A control group treated with tiamulin did not show significant changes in the numbers or proportions of tetracycline-resistant coliforms. Selection for tetracycline-resistant coliforms was significantly correlated to selection for ampicillin- and sulfonamide-resistant strains but not to selection for cefotaxime-resistant strains. In conclusion, the difference in the dose of oxytetracycline and the way in which the drug was applied did not cause significantly different levels of selection of tetracycline-resistant coliform bacteria under the conditions tested. IMPORTANCE Antimicrobial resistance is a global threat to human health. Treatment of livestock with antimicrobials has a direct impact on this problem, and there is a need to improve the ways that we use antimicrobials in livestock

  16. Construction of an extended range whole-cell tetracycline biosensor by use of the tet(M) resistance gene

    DEFF Research Database (Denmark)

    Bahl, Martin Iain; Hansen, Lars Hestbjerg; Sørensen, Søren Johannes

    2005-01-01

    An extended range whole-cell tetracycline biosensor strain was constructed by insertion of the tet(M) gene, encoding tetracycline resistance by ribosomal protection, into plasmid pTGFP2, which contains a transcriptional fusion between a tetracycline regulated promoter and the green fluorescent...... to drug concentrations ranging from below 5 ng ml-1 to 16 µg ml-1, which represents a significant improvement of the original version....

  17. Characterization of microbial community and antibiotic resistance genes in activated sludge under tetracycline and sulfamethoxazole selection pressure

    International Nuclear Information System (INIS)

    Zhang, Yingying; Geng, Jinju; Ma, Haijun; Ren, Hongqiang; Xu, Ke; Ding, Lili

    2016-01-01

    To investigate the microbial community characteristics, antibiotic resistance genes (ARGs), and bioreactor effluent quality change under tetracycline (TC) and sulfamethoxazole (SMX) selection pressure, sequencing batch reactors (SBRs) were used with environmentally relevant concentration and high-level of TC and SMX concentrations (0, 5 ppb, 50 ppb and 10 ppm). Chemical oxygen demand (COD) and ammonia nitrogen (NH 4 + −N) removals appeared unchanged (p > 0.05) with 5 and 50 ppb, but decreased significantly with 10 ppm (p < 0.05). Extracellular polymeric substances (EPS) concentrations increased significantly with increasing TC or SMX concentrations (p < 0.05). High-throughput 16S rRNA gene sequencing results suggested that Proteobacteria, Actinobacteria and Bacteroidetes were the three most abundant phyla in sludge samples. The Actinobacteria percentages increased with increasing TC or SMX concentration, while Proteobacteria and Bacteroidetes decreased. The microbial diversity achieved its maximum at 5 ppb and decreased with higher concentrations. The total ARGs abundances in sludge increased with addition of TC or SMX, and the higher relative abundances were in the order of sul1 > tetG > sul2 > tetA > intI1 > tetS > tetC. Pearson correlation analysis showed most ARGs (tetA, tetC, tetG, tetK, tetM, sul1) were significantly correlated with intI1 (p < 0.01). - Highlights: • COD and NH 4 + −N removals significantly decrease under 10 ppm TC or SMX. • Activated sludge EPS concentrations increase with increasing TC or SMX concentrations. • TC and SMX affect the microbial community diversity of activated sludge. • Actinobacteria abundances increase with increase of TC or SMX concentration. • ARGs abundance increases with addition of TC or SMX.

  18. Characterization of microbial community and antibiotic resistance genes in activated sludge under tetracycline and sulfamethoxazole selection pressure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yingying; Geng, Jinju, E-mail: jjgeng@nju.edu.cn; Ma, Haijun; Ren, Hongqiang; Xu, Ke; Ding, Lili

    2016-11-15

    To investigate the microbial community characteristics, antibiotic resistance genes (ARGs), and bioreactor effluent quality change under tetracycline (TC) and sulfamethoxazole (SMX) selection pressure, sequencing batch reactors (SBRs) were used with environmentally relevant concentration and high-level of TC and SMX concentrations (0, 5 ppb, 50 ppb and 10 ppm). Chemical oxygen demand (COD) and ammonia nitrogen (NH{sub 4}{sup +}−N) removals appeared unchanged (p > 0.05) with 5 and 50 ppb, but decreased significantly with 10 ppm (p < 0.05). Extracellular polymeric substances (EPS) concentrations increased significantly with increasing TC or SMX concentrations (p < 0.05). High-throughput 16S rRNA gene sequencing results suggested that Proteobacteria, Actinobacteria and Bacteroidetes were the three most abundant phyla in sludge samples. The Actinobacteria percentages increased with increasing TC or SMX concentration, while Proteobacteria and Bacteroidetes decreased. The microbial diversity achieved its maximum at 5 ppb and decreased with higher concentrations. The total ARGs abundances in sludge increased with addition of TC or SMX, and the higher relative abundances were in the order of sul1 > tetG > sul2 > tetA > intI1 > tetS > tetC. Pearson correlation analysis showed most ARGs (tetA, tetC, tetG, tetK, tetM, sul1) were significantly correlated with intI1 (p < 0.01). - Highlights: • COD and NH{sub 4}{sup +}−N removals significantly decrease under 10 ppm TC or SMX. • Activated sludge EPS concentrations increase with increasing TC or SMX concentrations. • TC and SMX affect the microbial community diversity of activated sludge. • Actinobacteria abundances increase with increase of TC or SMX concentration. • ARGs abundance increases with addition of TC or SMX.

  19. Helicobacter pylori resistance rates for levofloxacin, tetracycline and rifabutin among Irish isolates at a reference centre.

    LENUS (Irish Health Repository)

    O'Connor, A

    2013-04-27

    INTRODUCTION: Helicobacter pylori eradication rates using conventional triple therapies are falling, making viable second-line and rescue regimens necessary. Levofloxacin, tetracycline and rifabutin are three efficacious antibiotics for rescue therapy. AIM: We aimed to assess the resistance rates for H. pylori against these antibiotics in an Irish cohort. METHODS: Gastric biopsies were collected from 85 patients infected with H. pylori (mean age 46 years) in the Adelaide and Meath Hospital, Dublin in 2008 and 2009. Susceptibility to antibiotics was tested using the Etest. Clinical information was obtained from endoscopy reports and chart review. RESULTS: 50.6 % of patients were females. Mean age was 47 years. Ten had prior attempts at eradication therapy with amoxicillin-clarithromycin-PPI, two had levofloxacin-based second-line therapy. 11.7 % [95 % CI (6.5-20.3 %)] (N = 10) had strains resistant to levofloxacin. There were no strains resistant to rifabutin or tetracycline. Levofloxacin resistance in the under 45 age group was 2.6 % (1\\/38) compared to 19.1 % (9\\/47) of above 45 age group (p = 0.02). DISCUSSION: The levofloxacin rates illustrated in this study are relatively low by European standards and in line with other studies from the United Kingdom and Germany, with younger patients having very low levels of resistance. Levofloxacin, tetracycline and rifabutin are all valid options for H. pylori eradication in Irish patients but the importance of compliance cannot be underestimated.

  20. Synthetic tetracycline-inducible regulatory networks: computer-aided design of dynamic phenotypes.

    Science.gov (United States)

    Sotiropoulos, Vassilios; Kaznessis, Yiannis N

    2007-01-09

    Tightly regulated gene networks, precisely controlling the expression of protein molecules, have received considerable interest by the biomedical community due to their promising applications. Among the most well studied inducible transcription systems are the tetracycline regulatory expression systems based on the tetracycline resistance operon of Escherichia coli, Tet-Off (tTA) and Tet-On (rtTA). Despite their initial success and improved designs, limitations still persist, such as low inducer sensitivity. Instead of looking at these networks statically, and simply changing or mutating the promoter and operator regions with trial and error, a systematic investigation of the dynamic behavior of the network can result in rational design of regulatory gene expression systems. Sophisticated algorithms can accurately capture the dynamical behavior of gene networks. With computer aided design, we aim to improve the synthesis of regulatory networks and propose new designs that enable tighter control of expression. In this paper we engineer novel networks by recombining existing genes or part of genes. We synthesize four novel regulatory networks based on the Tet-Off and Tet-On systems. We model all the known individual biomolecular interactions involved in transcription, translation, regulation and induction. With multiple time-scale stochastic-discrete and stochastic-continuous models we accurately capture the transient and steady state dynamics of these networks. Important biomolecular interactions are identified and the strength of the interactions engineered to satisfy design criteria. A set of clear design rules is developed and appropriate mutants of regulatory proteins and operator sites are proposed. The complexity of biomolecular interactions is accurately captured through computer simulations. Computer simulations allow us to look into the molecular level, portray the dynamic behavior of gene regulatory networks and rationally engineer novel ones with useful

  1. Synthetic tetracycline-inducible regulatory networks: computer-aided design of dynamic phenotypes

    Directory of Open Access Journals (Sweden)

    Kaznessis Yiannis N

    2007-01-01

    Full Text Available Abstract Background Tightly regulated gene networks, precisely controlling the expression of protein molecules, have received considerable interest by the biomedical community due to their promising applications. Among the most well studied inducible transcription systems are the tetracycline regulatory expression systems based on the tetracycline resistance operon of Escherichia coli, Tet-Off (tTA and Tet-On (rtTA. Despite their initial success and improved designs, limitations still persist, such as low inducer sensitivity. Instead of looking at these networks statically, and simply changing or mutating the promoter and operator regions with trial and error, a systematic investigation of the dynamic behavior of the network can result in rational design of regulatory gene expression systems. Sophisticated algorithms can accurately capture the dynamical behavior of gene networks. With computer aided design, we aim to improve the synthesis of regulatory networks and propose new designs that enable tighter control of expression. Results In this paper we engineer novel networks by recombining existing genes or part of genes. We synthesize four novel regulatory networks based on the Tet-Off and Tet-On systems. We model all the known individual biomolecular interactions involved in transcription, translation, regulation and induction. With multiple time-scale stochastic-discrete and stochastic-continuous models we accurately capture the transient and steady state dynamics of these networks. Important biomolecular interactions are identified and the strength of the interactions engineered to satisfy design criteria. A set of clear design rules is developed and appropriate mutants of regulatory proteins and operator sites are proposed. Conclusion The complexity of biomolecular interactions is accurately captured through computer simulations. Computer simulations allow us to look into the molecular level, portray the dynamic behavior of gene regulatory

  2. Aspiration and tetracycline sclerotherapy of primary vaginal hydrocoele of testis in adults

    International Nuclear Information System (INIS)

    Ali, J.; Anwar, W.

    2008-01-01

    Primary Vaginal Hydrocoele of Testis is a common condition which is primarily treated surgically. Many patients with Hydrocoele of testis are either not willing or are unfit for surgery. This study was done to know the safety, efficacy and out come of tetracycline induced sclerotherapy of Primary Vaginal Hydrocoele of Testis in adults. This quasi experimental study was done in Shahina Jamil Hospital, attached with Frontier Medical College and Ayub Teaching Hospital, Abbottabad from March 2006 to April, 2007. Thirty-seven patients with primary vaginal hydrocoele were included in the study. Aspiration and instillation of Tetracycline was done after spermatic cord block with 2% lignocaine. Procedure time, Peri and Post-procedure complications, number of injections for cure and patients satisfaction with the procedure were recorded. Patients were discharged home 3 to 4 hours after the procedure and followed up after one week, one month, three months and six months. Direct admission and re-admissions were recorded. The mean age of patients was 47 years. Mean procedure time was 45 minutes. All patients were cured. Mild postoprocedure pain occurred in 12 (40%), moderate pain in 14 (46%) patients and severe pain in 4 (13.3%) patients. No patient developed haematoma or local infection. One patient (3.3%) had micturition problem. Two (6.6%) patients had minimal recurrence. One injection was sufficient for cure in all patients, 28 (93%) patients were satisfied while 2 (6.6%) patients were not satisfied with this procedure. No patient was admitted in the hospital after the procedure. Aspiration and injection of tetracycline in Primary vaginal Hydrocoele of Testis in adults is safe, effective and very economical procedure. (author)

  3. Tetracycline resistance genes persist in soil amended with cattle feces independently from chlortetracycline selection pressure

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Kotrbová, Lucie; Bhumibhamon, G.; Chroňáková, Alica; Jirout, Jiří; Vrchotová, Naděžda; Schmitt, H.; Elhottová, Dana

    2015-01-01

    Roč. 81, February (2015), s. 259-265 ISSN 0038-0717 R&D Projects: GA ČR GAP504/10/2077; GA MŠk(CZ) EE2.3.30.0032; GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:60077344 ; RVO:67179843 Keywords : antibiotic resistance * cattle feces * chlortetracycline * grassland soil * tetracycline resistance genes * intI1 gene Subject RIV: EE - Microbiology, Virology; CE - Biochemistry (UEK-B) Impact factor: 4.152, year: 2015

  4. Characterization of transferable tetracycline resistance genes in Enterococcus faecalis isolated from raw food

    DEFF Research Database (Denmark)

    Wilcks, Andrea; Andersen, Sigrid Rita; Licht, Tine Rask

    2005-01-01

    The prevalence of tetracycline resistance, and of specific genetic determinants for this resistance was investigated in 1003 strains of Enterococcus faecalis isolated from various raw food products originating from five categories including chicken meat, other poultry meat, beef, pork, and 'other......'. For the 238 resistant isolates identified, the ability to transfer the resistant phenotype to a given recipient in vitro was investigated. New and interesting observations were that the tet(L) resistance determinant was more readily transferred than tet(M), and that the presence of Tn916-like elements known...

  5. The rarely reported tet(31) tetracycline resistance determinant is common in Gallibacterium anatis

    DEFF Research Database (Denmark)

    Bojesen, Anders M.; Bager, Ragnhild J.; Ifrah, Dan

    2011-01-01

    The present investigation was undertaken to identify and characterize the tetracycline resistance determinant in 22 Gallibacterium anatis strains for which no determinant was identified using primers specific for tet(A, B, C, D, E, G, H, K, L, M, O). A recent study found tet(B) to be the most pre...... from very different production systems and localities. In addition, tet(31) was identified in strains isolated over a 30-year period. This is the first report on tet(31) since its original identification in Aeromonas salmonicida....

  6. "Tetracycline hydrochloride chemical burn" as self-inflicted mucogingival injury: A rare case report

    Directory of Open Access Journals (Sweden)

    Mundoor Manjunath Dayakar

    2012-01-01

    Full Text Available Injuries to oral soft tissue can be accidental, iatrogenic, and factitious trauma. Chemical, thermal, and physical agents are the main causative agents for oral soft-tissue burns. The present case describes the chemical burn of oral mucosa caused by tetracycline hydrochloride and its management. Diagnosis was made on the basis of definitive history elicited from the patient. The early detection of the lesion by the patient and immediate institution of therapeutic measures ensure a rapid cure and possible prevention of further mucogingival damage. In addition, we believe that proper guidance and education of the patient is an important prophylactic measure in preventing this self-inflicting injury.

  7. Adverse effect of tetracycline and doxycycline on reproductive tract development of CD1 mice

    Czech Academy of Sciences Publication Activity Database

    Elzeinová, Fatima; Pěknicová, Jana; Děd, Lukáš; Dorosh, Andriy; Kubátová, Alena; Margaryan, Hasmik; Makovický, P.; Rajmon, R.

    2012-01-01

    Roč. 67, Issue Supplement s1 (2012), s. 47-48 ISSN 1046-7408. [13th International Symposium for Immunology of reproduction "From the roots to the tops of Reproductive Immunology". 22.06.2012-24.06.2012, Varna] R&D Projects: GA ČR(CZ) GA523/09/1793; GA ČR(CZ) GAP503/12/1834 Institutional research plan: CEZ:AV0Z50520701 Keywords : tetracycline * doxycycline * CD1 mice * reproduction Subject RIV: DN - Health Impact of the Environment Quality

  8. Application of manure containing tetracyclines slowed down the dissipation of tet resistance genes and caused changes in the composition of soil bacteria.

    Science.gov (United States)

    Xiong, Wenguang; Wang, Mei; Dai, Jinjun; Sun, Yongxue; Zeng, Zhenling

    2018-01-01

    Manure application contributes to the increased environmental burden of antibiotic resistance genes (ARGs). We investigated the response of tetracycline (tet) resistance genes and bacterial taxa to manure application amended with tetracyclines over two months. Representative tetracyclines (oxytetracycline, chlorotetracycline and doxycycline), tet resistance genes (tet(M), tet(O), tet(W), tet(S), tet(Q) and tet(X)) and bacterial taxa in the untreated soil, +manure, and +manure+tetracyclines groups were analyzed. The abundances of all tet resistance genes in the +manure group were significantly higher than those in the untreated soil group on day 1. The abundances of all tet resistance genes (except tet(Q) and tet(X)) were significantly lower in the +manure group than those in the +manure+tetracyclines group on day 30 and 60. The dissipation rates were higher in the +manure group than those in the +manure+tetracyclines group. Disturbance of soil bacterial community composition imposed by tetracyclines was also observed. The results indicated that tetracyclines slowed down the dissipation of tet resistance genes in arable soil after manure application. Application of manure amended with tetracyclines may provide a significant selective advantage for species affiliated to the taxonomical families of Micromonosporaceae, Propionibacteriaceae, Streptomycetaceae, Nitrospiraceae and Clostridiaceae. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. The effect of production type and antimicrobial usage on the occurrence of tetracycline resistant E. coli in danish slaughter pig farms

    DEFF Research Database (Denmark)

    Struve, Tina; Vigre, Håkan; Wingstrand, Anne

    systems. At nine different slaughterhouses 1500 ceacum samples were collected from slaughter pigs originating from 226 farms. One thousand samples were analyzed and one E. coli isolate per sample was susceptibility tested to Tetracycline. Data on management practice and health status at farm level...... of Tetracycline usage was estimated using a quadratic polynomial. This showed a significant effect of Tetracycline consumption on the occurrence of Tetracycline resistance, where the occurrence of resistance increased by increased antimicrobial usage. Production type had significant effect on the occurrence...

  10. Deep learning relevance

    DEFF Research Database (Denmark)

    Lioma, Christina; Larsen, Birger; Petersen, Casper

    2016-01-01

    train a Recurrent Neural Network (RNN) on existing relevant information to that query. We then use the RNN to "deep learn" a single, synthetic, and we assume, relevant document for that query. We design a crowdsourcing experiment to assess how relevant the "deep learned" document is, compared...

  11. β-cyclodextrin-ionic liquid polymer based dynamically coating for simultaneous determination of tetracyclines by capillary electrophoresis.

    Science.gov (United States)

    Zhou, Chunyan; Deng, Jingjing; Shi, Guoyue; Zhou, Tianshu

    2017-04-01

    Tetracyclines are a group of broad spectrum antibiotics widely used in animal husbandry to prevent and treat diseases. However, the improper use of tetracyclines may result in the presence of their residues in animal tissues or waste. Recently, great attention has been drawn towards the green solvents ionic liquids. Ionic liquids have been employed as a coating material to modify the electroosmotic flow in capillary electrophoresis. In this study, a functionalized ionic liquid, mono-6-deoxy-6-(3-methylimidazolium)-β-cyclodextrin tosylate, was synthesized and used for the simultaneous separation and quantification of tetracyclines by capillary electrophoresis. Good separation efficiency could be achieved due to the multiple functions of β-cyclodextrin derived ionic liquid, including the electrostatic interaction, the hydrogen bonding, and the cavity structure in β-cyclodextrin ionic liquid which can entrap the tetracyclines to form inclusion complex. After optimization, baseline separation achieved in 25 min with the running buffer consisted of 10 mmol/L, pH 7.2 phosphate buffer and 20 mmol/L β-cyclodextrin ionic liquid. The satisfied result demonstrated that the β-cyclodextrin ionic liquid is an ideal background electrolyte modifier in the separation of tetracyclines with high stability and good reproducibility. And it is an effective strategy to design and synthesize specific ILs as additive applied in separation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Effect of citric acid, tetracycline, and doxycycline on instrumented periodontally involved root surfaces: A SEM study

    Directory of Open Access Journals (Sweden)

    Gurparkash Singh Chahal

    2014-01-01

    Full Text Available Background: A surface smear layer consisting of organic and inorganic material is formed on the root surface following mechanical instrumentation and may inhibit the formation of new connective tissue attachment to the root surface. Modification of the tooth surface by root conditioning has resulted in improved connective tissue attachment and has advanced the goal of reconstructive periodontal treatment. Aim: The aim of this study was to compare the effects of citric acid, tetracycline, and doxycycline on the instrumented periodontally involved root surfaces in vitro using a scanning electron microscope. Settings and Design: A total of 45 dentin samples obtained from 15 extracted, scaled, and root planed teeth were divided into three groups. Materials and Methods: The root conditioning agents were applied with cotton pellets using the "Passive burnishing technique" for 5 minutes. The samples were then examined by the scanning electron microscope. Statistical Analysis Used: The statistical analysis was carried out using Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, version 15.0 for Windows. For all quantitative variables means and standard deviations were calculated and compared. For more than two groups ANOVA was applied. For multiple comparisons post hoc tests with Bonferroni correction was used. Results: Upon statistical analysis the root conditioning agents used in this study were found to be effective in removing the smear layer, uncovering and widening the dentin tubules and unmasking the dentin collagen matrix. Conclusion: Tetracycline HCl was found to be the best root conditioner among the three agents used.

  13. Molecular basis and transferability of tetracycline resistance in Enterococcus italicus LMG 22195 from fermented milk.

    Science.gov (United States)

    Zago, Miriam; Huys, Geert; Giraffa, Giorgio

    2010-08-15

    A tetracycline-resistant Enterococcus italicus strain from fermented milk, LMG 22195, was found to contain a tet(S) gene located on a plasmid of approximately 20kb. Filter mating demonstrated that the tet(S) gene was transferable from LMG 22195 to the recipient Enterococcus faecalis JH2-2. PCR-based detection and Southern blot experiments revealed that the confirmed transconjugants acquired the tet(S)-carrying plasmid. Similar to the donor strain, transconjugants displayed a tetracycline MIC of 64 microg/ml. Results of this study suggest that E. italicus, like other enterococcal species, is able to disseminate antibiotic-resistance genes, although a more definitive proof on this statement will be provided when a higher number of strains will be tested. Because of the recent isolation of E. italicus from human clinical specimens and its concomitant presence in various dairy products, the ability of this organism to horizontally transfer tet(S) or other resistance genes may potentially pose safety concerns, especially for its possible use in food fermentations. Copyright 2010 Elsevier B.V. All rights reserved.

  14. Evaluation of commercially available biodegradable tetracycline fiber therapy in chronic periodontitis

    Directory of Open Access Journals (Sweden)

    Surinder Sachdeva

    2011-01-01

    Full Text Available Background: Chronic periodontitis is an inflammatory disorder caused by dental plaque having mixed microbial flora. The different treatment modalities available to treat this disease are aimed at removal of micro-organisms from both hard and soft tissues. Systemic as well as local anti-microbial agents are helpful adjuncts in reducing microbes especially in inaccessible areas along with mechanical debridement therapy. Materials and Methods: The study was conducted in a split mouth design. Thirty-five patients having at least two non-adjacent sites in different quadrants with periodontal pockets ≥5 mm and with bleeding on probing at initial visit were selected. The selected sites were treated with both scaling and root planing plus tetracycline fibers or with scaling and root planing alone. Baseline and follow-up measurements included plaque index, gingival index, probing pocket depth, and clinical attachment level. Result: Both treatment modalities were affective in improving clinical parameters over three months′ observation period. The combined antimicrobial and mechanical debridement therapy has shown better results as compared with scaling and root planing alone. Conclusion: Application of tetracycline in modified collagen matrix following scaling and root planing might be beneficial in treatment of chronic periodontitis and improving periodontal parameters for 3-month duration.

  15. Pharmacokinetic-pharmacodynamic model to evaluate intramuscular tetracycline treatment protocols to prevent antimicrobial resistance in pigs.

    Science.gov (United States)

    Ahmad, Amais; Græsbøll, Kaare; Christiansen, Lasse Engbo; Toft, Nils; Matthews, Louise; Nielsen, Søren Saxmose

    2015-03-01

    High instances of antimicrobial resistance are linked to both routine and excessive antimicrobial use, but excessive or inappropriate use represents an unnecessary risk. The competitive growth advantages of resistant bacteria may be amplified by the strain dynamics; in particular, the extent to which resistant strains outcompete susceptible strains under antimicrobial pressure may depend not only on the antimicrobial treatment strategies but also on the epidemiological parameters, such as the composition of the bacterial strains in a pig. This study evaluated how variation in the dosing protocol for intramuscular administration of tetracycline and the composition of bacterial strains in a pig affect the level of resistance in the intestine of a pig. Predictions were generated by a mathematical model of competitive growth of Escherichia coli strains in pigs under specified plasma concentration profiles of tetracycline. All dosing regimens result in a clear growth advantage for resistant strains. Short treatment duration was found to be preferable, since it allowed less time for resistant strains to outcompete the susceptible ones. Dosing frequency appeared to be ineffective at reducing the resistance levels. The number of competing strains had no apparent effect on the resistance level during treatment, but possession of fewer strains reduced the time to reach equilibrium after the end of treatment. To sum up, epidemiological parameters may have more profound influence on growth dynamics than dosing regimens and should be considered when designing improved treatment protocols. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. The difference of saline and sterile water for tetracycline hydrochloride solvents in cementum demineralization

    Directory of Open Access Journals (Sweden)

    Shinta Ferronika

    2016-12-01

    Full Text Available Background: The root cementum demineralization is an important step in regenerative periodontal therapy to smear layer removal on the root surface. Smear layer on the root surface becomes a barrier of the new attachment between periodontal tissues with the root surface. The use of tetracycline capsules as root surface demineralizing agent cannot be applied directly on the root surface and solvents such as saline or sterile water are needed. Purpose: The aim of this study was to determine differences between sterile water and saline solvent for tetracycline HCl (tetra HCl as a cementum demineralization. Method: In this study the specimens were divided into three groups: a control, tetra HCl dissolved in saline, and tetra HCl dissolved in sterile water. Application using burnishing method for 3 minutes. Samples were dehydrated with ethanol series of 30% to 100%. Results of the root demineralization observed by scanning electron microscopy (SEM. Statistical analysis was performed using the Kruskal-Wallis followed by a Mann-Whitney nonparametric test. Result: Upon statistical analysis showed that the sterile water as a solvent of tetra HCl is more effective in smear layer removal and collagen structure exposure in the cementum. Conclusion: Tetra HCl dissolved in sterile water was found to be the best root cementum demineralization agent.

  17. Mark-recapture using tetracycline and genetics reveal record-high bear density

    Science.gov (United States)

    Peacock, E.; Titus, K.; Garshelis, D.L.; Peacock, M.M.; Kuc, M.

    2011-01-01

    We used tetracycline biomarking, augmented with genetic methods to estimate the size of an American black bear (Ursus americanus) population on an island in Southeast Alaska. We marked 132 and 189 bears that consumed remote, tetracycline-laced baits in 2 different years, respectively, and observed 39 marks in 692 bone samples subsequently collected from hunters. We genetically analyzed hair samples from bait sites to determine the sex of marked bears, facilitating derivation of sex-specific population estimates. We obtained harvest samples from beyond the study area to correct for emigration. We estimated a density of 155 independent bears/100 km2, which is equivalent to the highest recorded for this species. This high density appears to be maintained by abundant, accessible natural food. Our population estimate (approx. 1,000 bears) could be used as a baseline and to set hunting quotas. The refined biomarking method for abundance estimation is a useful alternative where physical captures or DNA-based estimates are precluded by cost or logistics. Copyright ?? 2011 The Wildlife Society.

  18. Rapid startup of thermophilic anaerobic digester to remove tetracycline and sulfonamides resistance genes from sewage sludge.

    Science.gov (United States)

    Xu, Rui; Yang, Zhao-Hui; Wang, Qing-Peng; Bai, Yang; Liu, Jian-Bo; Zheng, Yue; Zhang, Yan-Ru; Xiong, Wei-Ping; Ahmad, Kito; Fan, Chang-Zheng

    2018-01-15

    Spread of antibiotic resistance genes (ARGs) originating from sewage sludge is highlighted as an eminent health threat. This study established a thermophilic anaerobic digester using one-step startup strategy to quickly remove tetracycline and sulfonamides resistance genes from sewage sludge. At least 20days were saved in the startup period from mesophilic to thermophilic condition. Based on the results of 16S rDNA amplicons sequencing and predicted metagenomic method, the successful startup largely relied on the fast colonization of core thermophilic microbial population (e.g. Firmicutes, Proteobacteria, Actinobacteria). Microbial metabolic gene pathways for substrate degradation and methane production was also increased by one-step mode. In addition, real-time quantitative PCR approach revealed that most targeted tetracycline and sulfonamides resistance genes ARGs (sulI, tetA, tetO, tetX) were substantially removed during thermophilic digestion (removal efficiency>80%). Network analysis showed that the elimination of ARGs was attributed to the decline of their horizontal (intI1 item) and vertical (potential hosts) transfer-related elements under high-temperature. This research demonstrated that rapid startup thermophilic anaerobic digestion of wastewater solids would be a suitable technology for reducing quantities of various ARGs. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. RECONSTRUCTION OF CALCINED Zn -Al LAYERED DOUBLE HYDROXIDES DURING TETRACYCLINE ADSORPSION

    Directory of Open Access Journals (Sweden)

    G. M. Starukh

    2015-12-01

    Full Text Available Zn-Al mixed oxides containing ZnO different degree crystallinity were obtained by calcinations of Zn-Al layered double hydroxides (LDHs. The reconstruction of calcined Zn-Al LDHs has been performed under stirring in aqueous suspensions. The assynthesized LDHs, its decomposition products, as well as the reconstructed solids upon hydration were characterized by XRD, N2adsorption, differential and thermal gravimetric analysis. It was found that the ability of Zn-Al LDHs to recover a layered structure under the hydration of mixed oxides depends on the degree of ZnO crystallinity. The partial reconstruction of Zn-Al layered structure occurs in tetracycline solutions irrespective to the degree of ZnO crystallinity in calcined LDHs. Calcined Zn-Al LDHs demonstrate the higher adsorption capacity to tetracycline in comparison with as-prepared Zn-Al LDHs. The adsorption of TC on calcined and uncalcined ZnAl LDHs occurs on the centers of one particular type. It is suggested that surface complexation of the A-ring ligand of TC with Al-OH centers takes place.

  20. Degradation of Tetracycline with BiFeO3 Prepared by a Simple Hydrothermal Method

    Directory of Open Access Journals (Sweden)

    Zhehua Xue

    2015-09-01

    Full Text Available BiFeO3 particles (BFO were prepared by a simple hydrothermal method and characterized. BFO was pure, with a wide particle size distribution, and was visible light responsive. Tetracycline was chosen as the model pollutant in this study. The pH value was an important factor influencing the degradation efficiency. The total organic carbon (TOC measurement was emphasized as a potential standard to evaluate the visible light photocatalytic degradation efficiency. The photo-Fenton process showed much better degradation efficiency and a wider pH adaptive range than photocatalysis or the Fenton process solely. The optimal residual TOC concentrations of the photocatalysis, Fenton and photo-Fenton processes were 81%, 65% and 21%, while the rate constants of the three processes under the same condition where the best residual TOC was acquired were 9.7 × 10−3, 3.2 × 10−2 and 1.5 × 10−1 min−1, respectively. BFO was demonstrated to have excellent stability and reusability. A comparison among different reported advanced oxidation processes removing tetracycline (TC was also made. Our findings showed that the photo-Fenton process had good potential for antibiotic-containing waste water treatment. It provides a new method to deal with antibiotic pollution.

  1. Integrated disposable electrochemical immunosensors for the simultaneous determination of sulfonamide and tetracycline antibiotics residues in milk.

    Science.gov (United States)

    Conzuelo, Felipe; Campuzano, Susana; Gamella, María; Pinacho, Daniel G; Reviejo, A Julio; Marco, M Pilar; Pingarrón, José M

    2013-12-15

    The design, preparation and analytical performance of a novel integrated amperometric immunosensor based on the immobilization of selective capture antibodies on the surface of Protein G-modified screen-printed dual carbon electrodes (SPdCEs) for the multiplexed determination of sulfonamide and tetracycline antibiotics residues in milk is reported in this work. Protein G was covalently immobilized onto a 4-aminobenzoic acid (4-ABA) film grafted on the disposable electrode, and a direct competitive immunoassay using horseradish peroxidase (HRP)-labeled tracers was performed. The amperometric responses measured at -0.2 V vs. the silver pseudo-reference electrode of the SPdCE upon the addition of H2O2 in the presence of hydroquinone (HQ) as mediator were used to monitor the extent of the immunoreactions. The developed methodology showed very low limits of detection (in the low ppb level) for sulfonamide and tetracycline antibiotics tested in untreated milk samples, and a good selectivity against other antibiotic residues frequently detected in milk and dairy products. The usefulness of the dual immunosensor was demonstrated by analyzing spiked milk samples as well as a reference milk containing a certified oxytetracycline (OTC) content. Good recoveries were attained in an analysis time of 30 min. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Delayed tooth replantation in rats: effect of systemic antibiotic therapy with amoxicillin and tetracycline.

    Science.gov (United States)

    Gomes, Weglis Dyanne de Souza; Silva, Cristina Antoniali; Melo, Moriel Evangelista; Silva, Vanessa Ferreira da; Almeida, Melyna Marques de; Pedrini, Denise; Poi, Wilson Roberto; Sonoda, Celso Koogi; Panzarini, Sônia Regina

    2015-12-01

    Systemic antibiotic therapy (SAT) has usually been recommended after tooth replantation, but its actual value has been questioned. As there are no reports in the literature about its influence on tooth replantation, the aim of this study was to evaluate the influence of systemic administration of antibiotics (amoxicillin and tetracycline) at the different phases of the repair process (7, 15, 30 days) in delayed rat tooth replantation. Ninety Wistar rats (Rattus norvegicus albinus) had their maxillary right incisors extracted and bench-dried for 60 min. The dental papilla, enamel organ, pulp tissue, and root surface-adhered periodontal ligament were removed, and the teeth were replanted. The animals received no antibiotics (n = 30) or were medicated systemically with amoxicillin (n = 30) and tetracycline (n = 30), and were euthanized after 7, 15, and 30 days. Regardless of the evaluation period, the acute inflammatory infiltrate was less intense and root resorption presented smaller extent and depth in the group treated with amoxicillin. The results suggest that SAT has a positive influence on the repair process in delayed tooth replantation and that amoxicillin is an excellent treatment option. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Determination of Tetracycline and Fluoroquinolone Antibiotics at Trace Levels in Sludge and Soil

    Directory of Open Access Journals (Sweden)

    Marie-Virginie Salvia

    2015-01-01

    Full Text Available This work describes the development of a sensitive analytical method to determine simultaneously traces of tetracycline and fluoroquinolone antibiotics in sludge and soil, based on PLE extraction, followed by SPE purification and finally an analysis by LC-MS/MS. Recoveries were greater than 87% in the case of fluoroquinolones and between 25.4 and 41.7% for tetracyclines. Low relative standard deviations (<15% were obtained in both matrices. The limits of quantification were comprised between 1.1 and 4.6 ng/g and between 5 and 20 ng/g in soil and sludge, respectively. The method was then successfully applied to the analysis of the target antibiotics in sludge as well as soil that received spreading. The substances most frequently found and with the highest levels were fluoroquinolones with concentrations exceeding 1,000 ng/g in several samples of sludge and up to 16 ng/g in soil.

  4. Development of a new antibacterial biomaterial by tetracycline immobilization on calcium-alginate beads.

    Science.gov (United States)

    Ozseker, Emine Erdogan; Akkaya, Alper

    2016-10-20

    In recent years, increasing risk of infection, caused by resistant microorganism to antibiotics, has become the limelight discovery of new and natural antibacterial materials. Heavy metals, such as silver, copper, mercury and titanium, have antibacterial activity. Products, which improved these metals, do not have stable antibacterial property. Therefore, use of these products is restricted. The aim of this study was to immobilize tetracycline to alginate and improve an antibacterial biomaterial. For this purpose, calcium-alginate beads were formed by dropping to calcium-chloride solution and tetracycline was immobilized to beads using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide at optimum conditions. After immobilization, actualization of immobilization was investigated by analyzing ATR-FTIR spectrum and SEM images. Also, antibacterial property of obtained product was tested. Improved product demonstrated antibacterial property. It has potential for open wound, surgical drapes, bed and pillow sheath in hospitals and it may also be used for increasing human comfort in daily life. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Non-antibacterial tetracycline formulations: clinical applications in dentistry and medicine

    Directory of Open Access Journals (Sweden)

    Ying Gu

    2012-10-01

    Full Text Available In 1983, it was first reported that tetracyclines (TCs can modulate the host response, including (but not limited to inhibition of pathologic matrix metalloproteinase (MMP activity, and by mechanisms unrelated to the antibacterial properties of these drugs. Soon thereafter, strategies were developed to generate non-antibacterial formulations (subantimicrobial-dose doxycycline; SDD and compositions (chemically modified tetracyclines; CMTs of TCs as host-modulating drugs to treat periodontal and other inflammatory diseases. This review focuses on the history and rationale for the development of: (a SDD which led to two government-approved medications, one for periodontitis and the other for acne/rosacea and (b CMTs, which led to the identification of the active site of the drugs responsible for MMP inhibition and to studies demonstrating evidence of efficacy of the most potent of these, CMT-3, as an anti-angiogenesis agent in patients with the cancer, Kaposi's sarcoma, and as a potential treatment for a fatal lung disease (acute respiratory distress syndrome; ARDS. In addition, this review discusses a number of clinical studies, some up to 2 years’ duration, demonstrating evidence of safety and efficacy of SDD formulations in humans with oral inflammatory diseases (periodontitis, pemphigoid as well as medical diseases, including rheumatoid arthritis, post-menopausal osteopenia, type II diabetes, cardiovascular diseases, and a rare and fatal lung disease, lymphangioleiomyomatosis.

  6. Removal of tetracyclines, sulfonamides, and quinolones by industrial-scale composting and anaerobic digestion processes.

    Science.gov (United States)

    Liu, Hang; Pu, Chengjun; Yu, Xiaolu; Sun, Ying; Chen, Junhao

    2018-02-15

    This study evaluated and compared the removal of antibiotics by industrial-scale composting and anaerobic digestion at different seasons. Twenty compounds belonged to three classes of widely used veterinary antibiotics (i.e., tetracyclines, sulfonamides, and quinolones) were investigated. Results show that of the three groups of antibiotics, tetracyclines were dominant in swine feces and poorly removed by anaerobic digestion with significant accumulation in biosolids, particularly in winter. Compared to that in winter, a much more effective removal (> 97%) by anaerobic digestion was observed for sulfonamides in summer. By contrast, quinolones were the least abundant antibiotics in swine feces and exhibited a higher removal by anaerobic digestion in winter than in summer. The overall removal of antibiotics by aerobic composting could be more than 90% in either winter or summer. Nevertheless, compost products from livestock farms in Beijing contained much higher antibiotics than commercial organic fertilizers. Thus, industrial composting standards should be strictly applied to livestock farms to further remove antibiotics and produce high quality organic fertilizer.

  7. The effects of tetracycline, minocycline, doxycycline and ofloxacin on Prevotella intermedia biofilm.

    Science.gov (United States)

    Takahashi, N; Ishihara, K; Kimizuka, R; Okuda, K; Kato, T

    2006-12-01

    Prevotella intermedia, a black-pigmented, anaerobic, gram-negative bacterium, is associated with various type of periodontitis. Antibiotic treatments via a systemic or local route have been reported as being useful for treating periodontal disease. The purpose of this study was to examine the effects of four antibiotics, tetracycline (TET), minocycline (MINO), doxycycline (DOXY) and ofloxacin (OFLX) on P. intermedia biofilms at minimum inhibitory concentrations (MIC) from one-fold to 100-fold. MICs were determined for planktonic cells. Biofilm formation was determined with the crystal violet stain method and the bioactivities in the biofilms were determined with the adenosine triphosphate (ATP) -bioluminescent assay using a 96-well culture plate. At one-fold MIC, DOXY inhibited biofilm formation by P. intermedia ATCC 25611. Other antibiotics at one-fold MIC had no effects on the biofilm formation of tested bacterial strains. In P. intermedia ATCC 25611 biofilms, all the antibiotics tested showed inhibitory activities at five- to 100-fold MICs. In the biofilms of P. intermedia strains, except ATCC 25611, treated with three tetracycline antibiotics, the bioactivities were significantly increased, indicating the difficulties involved in designing antibiotic therapy for periodontal disease.

  8. Occurrence and Diversity of Tetracycline Resistance Genes in Lagoons and Groundwater Underlying Two Swine Production Facilities

    Science.gov (United States)

    Chee-Sanford, J. C.; Aminov, R.I.; Krapac, I.J.; Garrigues-Jeanjean, N.; Mackie, R.I.

    2001-01-01

    In this study, we used PCR typing methods to assess the presence of tetracycline resistance determinants conferring ribosomal protection in waste lagoons and in groundwater underlying two swine farms. All eight classes of genes encoding this mechanism of resistance [tet(O), tet(Q), tet(W), tet(M), tetB(P), tet(S), tet(T), and otrA] were found in total DNA extracted from water of two lagoons. These determinants were found to be seeping into the underlying groundwater and could be detected as far as 250 m downstream from the lagoons. The identities and origin of these genes in groundwater were confirmed by PCR-denaturing gradient gel electrophoresis and sequence analyses. Tetracycline-resistant bacterial isolates from groundwater harbored the tet(M) gene, which was not predominant in the environmental samples and was identical to tet(M) from the lagoons. The presence of this gene in some typical soil inhabitants suggests that the vector of antibiotic resistance gene dissemination is not limited to strains of gastrointestinal origin carrying the gene but can be mobilized into the indigenous soil microbiota. This study demonstrated that tet genes occur in the environment as a direct result of agriculture and suggested that groundwater may be a potential source of antibiotic resistance in the food chain.

  9. Occurrence and risk assessment of tetracycline antibiotics in soil from organic vegetable farms in a subtropical city, south China.

    Science.gov (United States)

    Xiang, Lei; Wu, Xiao-Lian; Jiang, Yuan-Neng; Yan, Qing-Yun; Li, Yan-Wen; Huang, Xian-Pei; Cai, Quan-Ying; Mo, Ce-Hui

    2016-07-01

    This study investigated the occurrence of tetracycline antibiotics in soils from different organic vegetable farms in Guangzhou, a subtropical city, South China and evaluated their ecological risk. Four tetracycline compounds (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) were extracted ultrasonically from soil samples (n = 69), with a solid-phase extraction cleanup, and were then measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The results showed that four compounds were detected in all samples, with the concentrations of the individual compounds ranging from 0.04 to 184.8 μg/kg (dry weight). The concentrations of tetracycline compounds in the soils from different vegetable farms varied greatly, but their patterns of distribution were similar. Doxycycline was the predominant compound with a mean of 21.87 μg/kg, followed by chlortetracycline. The concentrations of doxycycline and chlortetracycline in 7.46 % of the samples were higher than the ecotoxic effect trigger value (100 μg/kg) set by the Steering Committee of Veterinary International Committee on Harmonization. Additionally, the concentrations of tetracyclines in greenhouse soils were significantly lower than those in open-field soils. Risk assessment based on single compound exposure showed that doxycycline could pose medium or high risks. Compared with other studies, the levels of tetracyclines in this study were relatively low. The hypothesis that antibiotic residues in the soil of organic farms fertilized with manure are higher than in the soils of conventional farms was not supported in the area studied due to the high levels of moisture, temperature, and microbial activity.

  10. Effects of tetracycline and zinc on selection of methicillin-resistant Staphylococcus aureus (MRSA) sequence type 398 in pigs

    DEFF Research Database (Denmark)

    Moodley, Arshnee; Nielsen, Søren Saxmose; Guardabassi, Luca

    2011-01-01

    An in vivo experiment was conducted to evaluate the effects of tetracycline and zinc on pig colonization and transmission of methicillin-resistant Staphylococcus aureus (MRSA) sequence type (ST) 398. Eight piglets naturally colonized with MRSA ST398 and 8 MRSA-negative piglets of the same age...... housed with MRSA-positive animals became positive in all groups, whereas the carriage status of the animals in Groups 5 and 6 did not change. This study demonstrates that feed supplemented with tetracycline or zinc increases the numbers of MRSA ST398 in the nasal cavity of pigs. Transmission of MRSA from...

  11. Action physics

    Science.gov (United States)

    McGinness, Lachlan P.; Savage, C. M.

    2016-09-01

    More than a decade ago, Edwin Taylor issued a "call to action" that presented the case for basing introductory university mechanics teaching around the principle of stationary action [E. F. Taylor, Am. J. Phys. 71, 423-425 (2003)]. We report on our response to that call in the form of an investigation of the teaching and learning of the stationary action formulation of physics in a first-year university course. Our action physics instruction proceeded from the many-paths approach to quantum physics to ray optics, classical mechanics, and relativity. Despite the challenges presented by action physics, students reported it to be accessible, interesting, motivational, and valuable.

  12. Validation of HPLC method of analysis of tetracycline residues in eggs and broiler meat and its application to a feeding trial.

    Science.gov (United States)

    De Ruyck, H; De Ridder, H; Van Renterghem, R; Van Wambeke, F

    1999-02-01

    HPLC with ion-pairing chromatography and diodearray detection at 355 nm was used to determine tetracycline antibiotics in eggs and broiler meat. The analytical methods were optimized and validated. The mean recovery values for oxytetracycline for eggs and for tetracycline for breast meat were 76%. The within-day precision ranged from 8.0 to 11.8% for oxytetracycline in eggs and from 6.1 to 15.5% for tetracycline in breast meat. The between-day precision was 4.8% and 5.0% respectively for oxytetracycline in eggs and tetracycline in breast meat. The limit of detection and the limit of quantitation for oxytetracycline in eggs were 2.2 and 13.0 ng/g respectively. These limits for tetracycline in breast meat were 10.5 and 20.9 ng/g respectively. Residue values of tetracycline antibiotics in eggs and broiler meat were determined after oral administration of medicated feed. Medicated feed with 840 mg/kg oxytetracycline was provided to laying hens for seven successive days. Two days after the administration was stopped, the mean oxytetracycline residue value in the eggs was already lower than the Maximum Residue Limit (MRL)-level and reached 118 ng/g. Broilers were supplied with medicated feed containing 480 mg/kg tetracycline for seven successive days. Four days after the administration was stopped, the mean tetracycline residue value in breast meat decreased below the MRL and was 86 ng/g.

  13. Tetracycline and Glutathione Inhibit Matrix Metalloproteinase Activity: An In Vitro Study Using Culture Supernatants of L929 and Dalton Lymphoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Gajanan Kendre

    2013-01-01

    Full Text Available Tetracycline and glutathione inhibited the protease activities of matrix metalloproteinase-2 and matrix metalloproteinase-9 expressed by mouse fibrosarcoma cells (L929 and Dalton lymphoma cells, respectively. The inhibitory activity of the tetracycline may be due to its ability to chelate metal ions such as calcium and zinc. Gelatin-zymography technique was used to demonstrate the inhibitory activity of both tetracycline and glutathione. The intensity of the bands corresponding to metalloproteinase activity in zymography gel was reduced in the presence of 50–100 μg/mL of tetracycline. The presence of 10–100 μg/mL of tetracycline in the medium increased the adherence of L929 cancer cells. These results clearly indicate the antimetastatic property of tetracycline. Reduced glutathione, a compound which is produced endogenously by the cells to maintain the redox status, was shown to inhibit the matrix metalloproteinase activity (in vitro. Therefore, it is assumed that decreased glutathione levels in synovial fluids or plasma might increase the activity of MMP. Reduced glutathione at 100 μg/mL inhibited the metalloproteinase activity in gelatin-zymographic gel. As both tetracycline and glutathione exhibited an inhibitory effect on matrix metalloproteinase activity, it was of great interest to check their clinical effects on various MMP associated pathological conditions such as cancer metastasis and arthritis. Here we report that tetracycline and reduced glutathione inhibited the activity of MMP2 completely and activity of MMP9 partly.

  14. Tetracycline removal and effect on the formation and degradation of extracellular polymeric substances and volatile fatty acids in the process of hydrogen fermentation.

    Science.gov (United States)

    Hou, Guangying; Hao, Xiaoyan; Zhang, Rui; Wang, Jing; Liu, Rutao; Liu, Chunguang

    2016-07-01

    Many research indicate antibiotics show adverse effect on methane fermentation, while few research focus on their effect on hydrogen fermentation. The present study aimed to gain insight of the effect of antibiotics on hydrogen fermentation with waste sludge and corn straw as substrate. For this purpose, tetracycline, as a model, was investigated with regard to tetracycline removal, hydrogen production, interaction with extracellular polymeric substances (EPSs) of substrate and volatile fatty acids (VFAs) on concentration and composition. Results show that tetracycline could be removed efficiently by hydrogen fermentation, and relative low-dose tetracycline (200mg/l) exposure affects little on hydrogen production. While tetracycline exposure could change hydrogen fermentation from butyric acid-type to propionic acid-type depending on tetracycline level. Based upon three-dimensional excitation-emission matrix fluorescence spectroscopy and UV-vis tetracycline changed the component and content of EPSs, and static quenching was the main mechanism between EPSs with tetracycline. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Susceptibility of Escherichia coli and Enterococcus faecium isolated from pigs and broiler chickens to tetracycline degradation products and distribution of tetracycline resistance determinants in E-coli from food animals

    DEFF Research Database (Denmark)

    Sengeløv, G.; Halling-Sørensen, B.; Aarestrup, Frank Møller

    2003-01-01

    One hundred Escherichia coli isolates from diseased and healthy pigs, cattle and broiler chickens were screened for the presence of tetracycline resistance genes tet(A), (13), (C), (D) or (E). The tet(A) gene was the most abundant (71% of the 100 isolates) followed by tet(B) (25%). The predominan...

  16. Confirmatory assay for the determination of tetracycline, oxytetracycline, chlortetracycline and its isomers in muscle and kidney using liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Blanchflower, W J; McCracken, R J; Haggan, A S; Kennedy, D G

    1997-05-09

    A confirmatory method is described for the determination of tetracycline, oxytetracycline and chlortetracycline in muscle and kidney using liquid chromatography-atmospheric pressure chemical ionisation mass spectrometry. The tetracyclines were extracted from tissue using glycine-HCl buffer and concentrated using solid-phase extraction. HPLC separation was carried out using a gradient and the tetracyclines were detected using a bench-top LC-MS system. Several ions could be monitored for each tetracycline, allowing ion ratio measurements to be made. The detection limits for the assay were in the region of 10 ng/g in muscle and 20 ng/g in kidney. Validation was carried out at half the maximum residue limit, the maximum residue limit and two times the maximum residue limit. The formation of epimers and tautomers of the tetracyclines, their presence in incurred tissues and difficulties in their accurate quantitation is discussed.

  17. The effect of production type and antimicrobial usage on the occurrence of tetracycline resistant E. coli in danish slaughter pig farms

    DEFF Research Database (Denmark)

    Struve, Tina; Vigre, Håkan; Wingstrand, Anne

    (organic, free range and conventional farms) was a risk factor for occurrence of antimicrobial resistance and Tetracycline usage was regarded as an intervening factor between production type and occurrence of antimicrobial resistance. Therefore, the effect of production type and Tetracycline usage...... of Tetracycline usage was estimated using a quadratic polynomial. This showed a significant effect of Tetracycline consumption on the occurrence of Tetracycline resistance, where the occurrence of resistance increased by increased antimicrobial usage. Production type had significant effect on the occurrence...... of antimicrobial resistance, with the lowest occurrence in Organic production and the highest in Conventional production. When analyzing the effect of production type and usage of antimicrobials on occurrence of resistance in the same model, the usage of antimicrobials was not found to have an effect. This lack...

  18. Tetracycline-regulated transgene expression in hippocampal neurones following transfection with adenoviral vectors.

    Science.gov (United States)

    Harding, T C; Geddes, B J; Noel, J D; Murphy, D; Uney, J B

    1997-12-01

    A transfer system that enabled the efficient introduction of transgenes into neurones and the quantitative control of the expressed transgene would greatly facilitate studies into neuronal gene function. To develop such a system we incorporated the tetracycline (Tet)-responsive On/Off regulatory elements into type-5 adenoviral (Ad) vectors. Regulation of transgene expression following transfection was measured by placing the enhanced green fluorescent protein (EGFP) gene upstream of the Tet regulatory element. The results showed that cultures of primary hippocampal cells could be transfected with very high efficiency (<70%) by the AdTet-On and AdTet-Off systems. Following transfection with the AdTet-On system no EGFP-fluorescent cells could be detected until doxycycline was added. The AdTet-Off system showed the reverse transcriptional regulation, in that the addition of Tet caused EGFP fluorescence to be abolished.

  19. Effects of tetracycline administration on the proteomic profile of pig muscle samples (L. dorsi)

    DEFF Research Database (Denmark)

    Gratacos-Cubarsi, M.; Castellari, M.; Hortos, M.

    2008-01-01

    Effect of tetracycline (TC) administration on the proteomic profile of pig muscle was evaluated by 2D electrophoresis and MALDI-TOF mass spectrometry. The TC content at slaughter was determined in L. dorsi samples by HPLC-DAD. Mean residual concentration of TC in the muscle of treated animals......, calculated as the sum of TC and epi-TC was 126.3 mu g/kg, indicating a rapid elimination of TC in this tissue. Several differential spots (n = 54, p control and treated animals. MALDI-TOF identification gave a positive match for 5 differential spots, that is...... of differential spots as biomarkers to detect illegal administration of TC require further studies. Different spot patterns as a consequence of TC treatments seem to be another interesting issue for the consequences on tissue metabolism and meat quality....

  20. Large-scale enzymatic membrane reactors for tetracycline degradation in WWTP effluents.

    Science.gov (United States)

    Abejón, R; De Cazes, M; Belleville, M P; Sanchez-Marcano, J

    2015-04-15

    A mathematical model to simulate the performance of enzymatic membrane reactors was developed. It was applied to investigate the effectiveness of laccase immobilized over ceramic membranes for the degradation of tetracycline, a common antibiotic appearing as micropollutant in effluents of WWTPs. A process based on large-scale enzymatic membrane reactors in series was proposed for the treatment of the effluents from municipal, hospital and industrial wastewater treatment plants (WWTPs). The obtained results demonstrated the need for high improvements in the amount of enzyme grafted on the membranes or on enzymatic kinetics to afford the technical and economic competitiveness of the investigated designs and the possibility to be implemented within existing installations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Symptomatic hepatic cyst in a child: treatment with single-shot injection of tetracycline hydrochloride

    International Nuclear Information System (INIS)

    Fabrizzi, Giancarlo; Lanza, Cecilia; Bolli, Valeria; Pieroni, Giovanni

    2009-01-01

    The prevalence of hepatic cysts is 0.1% to 0.5% based on autopsy studies, and 2.5% based on US examinations. Percutaneous therapies are a new alternative to surgery. They include simple percutaneous aspiration, catheter drainage alone, and catheter drainage with sclerotherapy. We present an 11-year-old boy admitted to hospital because of abdominal pain. A diagnosis of simple hepatic cyst was made, which was treated with aspiration and tetracycline hydrochloride solution (5%) injection into the cystic cavity. Complete regression was seen on US and MRI examination at 3 months, with total collapse and deflation of the cyst. The cyst regressed totally, leaving a hyperechoic linear scar on US examination at 1 year. On the basis of the clinical and imaging results obtained, percutaneous sclerotherapy of hepatic cysts can be recommended as the treatment of choice and as a valid alternative to laparoscopy in children. (orig.)

  2. Symptomatic hepatic cyst in a child: treatment with single-shot injection of tetracycline hydrochloride

    Energy Technology Data Exchange (ETDEWEB)

    Fabrizzi, Giancarlo; Lanza, Cecilia; Bolli, Valeria; Pieroni, Giovanni [Azienda Ospedaliero-Universitaria Ospedali Riuniti, Servizio di Radiologia Generale e Pediatrica, Ancona (Italy)

    2009-10-15

    The prevalence of hepatic cysts is 0.1% to 0.5% based on autopsy studies, and 2.5% based on US examinations. Percutaneous therapies are a new alternative to surgery. They include simple percutaneous aspiration, catheter drainage alone, and catheter drainage with sclerotherapy. We present an 11-year-old boy admitted to hospital because of abdominal pain. A diagnosis of simple hepatic cyst was made, which was treated with aspiration and tetracycline hydrochloride solution (5%) injection into the cystic cavity. Complete regression was seen on US and MRI examination at 3 months, with total collapse and deflation of the cyst. The cyst regressed totally, leaving a hyperechoic linear scar on US examination at 1 year. On the basis of the clinical and imaging results obtained, percutaneous sclerotherapy of hepatic cysts can be recommended as the treatment of choice and as a valid alternative to laparoscopy in children. (orig.)

  3. Distribution of quinolones, sulfonamides, tetracyclines in aquatic environment and antibiotic resistance in Indochina

    Directory of Open Access Journals (Sweden)

    Satoru eSuzuki

    2012-02-01

    Full Text Available Southeast Asia has become the center of rapid industrial development and economic growth. However, this growth has far outpaced investment in public infrastructure, leading to the unregulated release of many pollutants, including wastewater-related contaminants such as antibiotics. Antibiotics are of major concern because they can easily be released into the environment from numerous sources, and can subsequently induce development of antibiotic-resistant bacteria. Recent studies have shown that for some categories of drugs this source-to-environment antibiotic resistance relationship is more complex. This review summarizes current understanding regarding the presence of quinolones, sulfonamides, and tetracyclines in aquatic environments of Indochina and the prevalence of bacteria resistant to them. Several noteworthy findings are discussed: 1 quinolone contamination and the occurrence of quinolone resistance are not correlated; 2 occurrence of the sul sulfonamide resistance gene varies geographically; and 3 microbial diversity might be related to the rate of oxytetracycline resistance.

  4. Biochar based removal of antibiotic sulfonamides and tetracyclines in aquatic environments: A critical review.

    Science.gov (United States)

    Peiris, Chathuri; Gunatilake, Sameera R; Mlsna, Todd E; Mohan, Dinesh; Vithanage, Meththika

    2017-12-01

    Utilization of biochar (BC) as a low cost adsorbent for water remediation has gained an immense research interest due to their surface functionality and porosity. Although many reports on the BC based sorptive removal of Sulfonamides (SA) and Tetracyclines (TC) are available in literature, a deep insight into sorption mechanisms is yet to be reviewed. Objective of this review is to fill the research gap of a methodological understanding of sorption mechanisms and characteristics which is essential to develop efficient methods for contaminant removal. The most common adsorption mechanism can be considered as electron donor-acceptor interactions of electron withdrawing moieties with surface arene rings. The strongest adsorption of both antibiotics occurs at mildly acidic pH where the dominant species are zwitterionic or cationic. Smaller SAs exhibit micro pore-filling effects while bulky TCs experience size exclusions. Furthermore, the effect of matrix components and modifications are also been taken into account. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Potential for tumor therapy with tritiated tetracycline. Summary evaluation. [Animal tests

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.C.; Wood, P.; Wood, L.L.; Mendelsohn, M.L.

    1976-10-26

    Reports of tetracycline accumulation in human and animal tumors have led a number of investigators to postulate that this drug, if radio-labeled, might have potential as a therapeutic or diagnostic agent. This paper describes attempts to investigate this potential for tritiated tetracycling. The therapeutic studies demonstrated that while a significant reduction in the growth rates of transplanted tumors could be obtained by the administration of heavy doses of TTC relative to uninjected controls, similar reductions were observed in the growth rates of tumors in animals receiving unlabeled TC. In the localization studies in rodents, the concentrations of TTC in normal tissues and tumors were compared and were correlated with the corresponding concentrations of /sup 14/C-thymidine, a measure of proliferative activity.

  6. Optimization of a liquid chromatographic method for determination of oxytetracycline, tetracycline, and chlortetracycline in milk.

    Science.gov (United States)

    White, C R; Moats, W A; Kotula, K L

    1993-01-01

    A liquid chromatographic (LC) method was developed for the simultaneous identification and quantitation of oxytetracycline, tetracycline, and chlortetracycline in milk. Milk samples (5 mL) were deproteinized by adding 1 mL 1N HCl and 24 mL acetonitrile, and filtering. Dichloromethane and hexane were added to 15 mL filtrate to separate the water layer. The organic layer was washed with 1 mL deionized water, and the combined water layers were diluted to 4 mL. Sample aliquots of 1000 microL were then injected directly and analyzed on an LC system. The sensitivity limit of the method is 5 ppb for each antibiotic; no interferences are present at their retention times. Mean recoveries from milk spiked at 0.01-1 ppm ranged from 87 to 99%, and precision was good.

  7. Pharmacokinetic-Pharmacodynamic Model To Evaluate Intramuscular Tetracycline Treatment Protocols To Prevent Antimicrobial Resistance in Pigs

    DEFF Research Database (Denmark)

    Ahmad, Amais; Græsbøll, Kaare; Christiansen, Lasse Engbo

    2015-01-01

    to which resistant strains outcompete susceptible strains under antimicrobial pressure may depend not only on the antimicrobial treatment strategies but also on the epidemiological parameters, such as the composition of the bacterial strains in a pig. This study evaluated how variation in the dosing......High instances of antimicrobial resistance are linked to both routine and excessive antimicrobial use, but excessive or inappropriate use represents an unnecessary risk. The competitive growth advantages of resistant bacteria may be amplified by the strain dynamics; in particular, the extent...... protocol for intramuscular administration of tetracycline and the composition of bacterial strains in a pig affect the level of resistance in the intestine of a pig. Predictions were generated by a mathematical model of competitive growth of Escherichia coli strains in pigs under specified plasma...

  8. [Residues of tetracycline in poultry meat and eggs due to the use of antibiotics].

    Science.gov (United States)

    Donkova, N V

    2005-01-01

    Experiments on broiler chicks and laying hens have indicated that increased drug loads (the prolonged oral use of oxytetracycline hydrochloride in a dose of 50 mg/kg or the single administration of its long-acting formulation--nitox in a dose of 200 mg/kg) lead to the accumulation of residues in the poultry flesh, by-products, and eggs even provided that the poultry exposure schedule before slaughtering is kept. The highest levels of the antibiotic are detectable at the site of injection and in the eggs after injection of nitox, a long-acting formulation of tetracycline. The detection of the residues of the antibiotic in the poultry flesh, by-products, and eggs may be associated with the development of cytotoxic effects and with the reduced functional capacities of the organs that are responsible for the detoxification and excretion of medicinal xenobiotics.

  9. Modulation of Cytokine and Cytokine Receptor/Antagonist by Treatment with Doxycycline and Tetracycline in Patients with Dengue Fever

    Directory of Open Access Journals (Sweden)

    J. E. Z. Castro

    2011-01-01

    Full Text Available Dengue virus infection can lead to dengue fever (DF or dengue hemorrhagic fever (DHF. Disease severity has been linked to an increase in various cytokine levels. In this study, we evaluated the effectiveness of doxycycline and tetracycline to modulate serum levels of IL-6, IL-1B, and TNF and cytokine receptor/receptor antagonist TNF-R1 and IL-1RA in patients with DF or DHF. Hospitalized patients were randomized to receive standard supportive care or supportive care combined with doxycycline or tetracycline therapy. Serum cytokine and cytokine receptor/antagonist levels were determined at the onset of therapy and after 3 and 7 days. Cytokine and cytokine receptor/antagonist levels were substantially elevated at day 0. IL-6, IL-1β, and TNF remained at or above day 0 levels throughout the study period in untreated patients. Treatment with tetracycline or doxycycline resulted in a significant decline in cytokine levels. Similarly, IL-1RA and TNF-R1 serum concentrations were elevated at baseline and showed a moderate increase among untreated patients. Both drugs resulted in a significant rise in IL-1Ra levels by day 3 in patients. In contrast, treatment did not affect a similar result for TNF-R1. When compared to the control group, however, a significant rise post-treatment was seen upon intragroup analysis. Further analysis demonstrated that doxycycline was significantly more effective at modulating cytokine and cytokine receptor/antagonist levels than tetracycline.

  10. Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

    Energy Technology Data Exchange (ETDEWEB)

    Tao Ran [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Su Haochang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Zhou Hongwei [Department of Environmental Health, School of Public Health and Tropical Medicine, Southern Medical University, 1838 North Guangzhou Street, Baiyun District, Guangzhou 510515 (China); Sidhu, Jatinder P.S. [CSIRO Land and Water, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia QLD 4067 (Australia)

    2010-06-15

    This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

  11. Influence of long-term treatment with tetracycline and niacinamide on antibody production in dogs with discoid lupus erythematosus.

    Science.gov (United States)

    Mueller, Ralf S; Fieseler, Kathryn V; Bettenay, Sonya V; Rosychuk, Rodney A W

    2002-04-01

    To evaluate the effect of long-term treatment with tetracycline and niacinamide on antibody production in dogs by measuring postvaccinal serum concentrations of antibodies against canine parvovirus and canine distemper virus. 10 dogs receiving long-term treatment with tetracycline and niacinamide (treatment group) and 10 healthy dogs (control group). The treatment group included 9 dogs with discoid lupus erythematosus and 1 dog with pemphigus foliaceus on long-term treatment (> 12 months) with tetracycline and niacinamide. The control group included 10 healthy dogs with no clinical signs of disease and no administered medications for the past 3 months. Blood samples were obtained from all dogs by jugular venipuncture. Serum antibody titers against canine parvovirus and canine distemper virus antigens were measured, using hemaglutination inhibition and serum neutralization, respectively, and compared between groups. A significant difference in antibody titers between treatment- and control-group dogs was not found. All dogs had protective antibody titers against canine distemper virus, and 8 of 10 dogs from each group had protective titers against canine parvovirus infection. These results provide evidence that long-term treatment with tetracycline and niacinamide does not interfere with routine vaccinations and thus does not seem to influence antibody production in dogs.

  12. Tetracycline-ferrite nanocomposites formed via high-energy ball milling and the influence of milling conditions.

    Science.gov (United States)

    Branham, Michael Lee; Moyo, Thomas; Abdallah, Hafiz M I; Masina, Patrick

    2013-02-01

    High-energy ball milling was used to mediate the formation of nanocomposites containing tetracycline and magnetic nanoparticles. Tetracycline-HCl was ball milled for 1, 3, 5, 15, and 30 h under argon or air atmosphere with preformed Mg 0.5 Zn 0.5 Fe2O4 nanoferrites prepared by glycolthermal method. The structural, thermal, and magnetic properties of these novel materials and the effect of milling atmosphere on composition, crystallinity and cation distribution were then characterized by ICP-OES, DSC/TGA, XRPD, ATR-IR, UV-Vis and Mössbauer spectroscopy. Tetracycline underwent rapid and consecutive metal coordination events in the milling process to yield complexes characterized by bathochromic shifts in its electronic spectra and suppression of electronic absorbance at 365 nm. Changes in stretching vibrations due to the A-ring carbonyl (1616 cm(-1)), amide II nitrogen (1602 cm(-1)), and CO bond (1039 cm(-1)) indicate Mg-type interactions imposed on the metals. Exothermic oxidation of the drug at 235°C disappeared after 5h milling with the nanoferrites, and the composites formed remained thermostable up to 500°C. Tetracycline-nanoferrites (Tet-NF) are magnetic-ordered materials with a well-defined spinel-type structure. Analysis of the Mössbauer data suggests that the milling time and atmosphere have significant influence on cation distributions in Tet-NF composites. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Identification of Tet 39, a novel class of tetracycline resistance determinant in Acinetobacter spp. of environmental and clinical origin

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Guardabassi, L.

    2005-01-01

    A novel tetracycline resistance determinant named Tet 39 was found in unrelated Acinetobacter strains isolated from freshwater trout farms (n=4) and sewage (n=6) in Denmark, and from a clinical specimen in the Netherlands (n=1). The determinant was located on transferable plasmids and consisted...

  14. Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

    International Nuclear Information System (INIS)

    Tao Ran; Ying Guangguo; Su Haochang; Zhou Hongwei; Sidhu, Jatinder P.S.

    2010-01-01

    This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

  15. Resistance to β-lactam and tetracycline in Campylobacter spp.isolated from broiler slaughterhouses in southern Brazil

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    Yuli M. Sierra-Arguello

    2015-07-01

    Full Text Available Abstract The study was carried out to screen and analyze the genetic characteristics of antimicrobial resistance in Campylobacter spp. from poultry sources. A total of 141 strains of Campylobacter isolated from samples of broilers of slaughterhouses in southern Brazil was identified by phenotypic and genotypic methods. Campylobacter isolates were evaluated for its antimicrobial susceptibility and the presence of resistance genes. The strains were investigated for antimicrobial susceptibility against two agents (ampicillin and tetracycline by disk diffusion method. PCR assay was used to confirm the specie and the presence of ampicillin (blaOXA-61, tetracycline tet(O, and the energy-dependent multi-drug efflux pump (cmeB genes. Campylobacter jejuni was the most ubiquitous; its presence was determined in 140 samples out of 141 (99.3%, whereas Campylobacter coli was found only in one of the contaminated samples (0.70%. The results obtained showed 65% and 35.5% of Campylobacter isolates resistant to β-lactams and tetracyclines, respectively. The cmeB gene responsible for multidrug resistance was detected in 26 isolates out 141 strains (18.5%. Moreover, 36 out of 141 Campylobacter strains (25.6% were found to be resistant to at least two different antimicrobia resistance markers (β-lactams and tetracyclines.

  16. Modulation of cytokine and cytokine receptor/antagonist by treatment with doxycycline and tetracycline in patients with dengue fever.

    Science.gov (United States)

    Castro, J E Z; Vado-Solis, I; Perez-Osorio, C; Fredeking, T M

    2011-01-01

    Dengue virus infection can lead to dengue fever (DF) or dengue hemorrhagic fever (DHF). Disease severity has been linked to an increase in various cytokine levels. In this study, we evaluated the effectiveness of doxycycline and tetracycline to modulate serum levels of IL-6, IL-1B, and TNF and cytokine receptor/receptor antagonist TNF-R1 and IL-1RA in patients with DF or DHF. Hospitalized patients were randomized to receive standard supportive care or supportive care combined with doxycycline or tetracycline therapy. Serum cytokine and cytokine receptor/antagonist levels were determined at the onset of therapy and after 3 and 7 days. Cytokine and cytokine receptor/antagonist levels were substantially elevated at day 0. IL-6, IL-1β, and TNF remained at or above day 0 levels throughout the study period in untreated patients. Treatment with tetracycline or doxycycline resulted in a significant decline in cytokine levels. Similarly, IL-1RA and TNF-R1 serum concentrations were elevated at baseline and showed a moderate increase among untreated patients. Both drugs resulted in a significant rise in IL-1Ra levels by day 3 in patients. In contrast, treatment did not affect a similar result for TNF-R1. When compared to the control group, however, a significant rise post-treatment was seen upon intragroup analysis. Further analysis demonstrated that doxycycline was significantly more effective at modulating cytokine and cytokine receptor/antagonist levels than tetracycline.

  17. [Resistance monitoring working group: resistance to erythromycin, ciprofloxacin, and tetracycline in human isolates of Campylobacter spp. in the Czech Republic tested by the EUCAST standard method].

    Science.gov (United States)

    Žemličková, H; Jakubů, V; Marejková, M; Urbášková, P

    2014-09-01

    To determine the frequency of Campylobacter spp. isolated from humans in the Czech Republic and to test their susceptibility to antimicrobials commonly used to treat campylobacteriosis by the standard EUCAST method. Consecutive Campylobacter isolates recovered from clinical specimens in 49 microbiological laboratories within one month in 2013 were identified using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Susceptibility to erythromycin, ciprofloxacin, and tetracycline was tested by the microdilution method and the results were interpreted based on the EUCAST clinical breakpoints to differentiate between susceptible and resistant strains. Of the study set of 769 Campylobacter spp. strains, 90.1 % were assigned to C. jejuni, 9.8 % to C. coli, and a single strain to C. fetus (0.1 %). Except one blood isolate of C. jejuni, all other isolates were recovered from the stool. Ciprofloxacin resistance (MIC > 0.5 mg/l) was detected in 61.9 % strains of C. jejuni and in 72.0 % strains of C. coli, tetracycline resistance (MIC > 2 mg/l) was detected in 32.0 % of strains of both species, and erythromycin resistance was found in 0.3 % of strains of C. jejuni (MIC > 8 mg/l) and in 2.7 % of strains of C. coli (MIC > 4 mg/l). A C. coli strain was multidrug resistant (i.e. resistant to all three antimicrobials tested). Despite the fact that most Campylobacter infections in humans cure on their own, the resistance of the causative strains to the antimicrobials of choice and alternative agents needs to be studied because of its relevance to the treatment of severe cases that require antibiotics. Resistance to macrolides was found rather infrequently in this study in both C. jejuni (0.1 %) and C. coli (2.7 %) strains. Nevertheless, alarming is ciprofloxacin resistance confirmed in 61.9 % of C. jejuni strains and 72.0 % C. coli strains. As the species C. coli is more often resistant to antimicrobials than C. jejuni and ciprofloxacin

  18. Characterization of the europium tetracycline complex as a biomarker for atherosclerosis

    Science.gov (United States)

    Courrol, Lilia C.; da Silva, Mônica N.; Sicchieri, Leticia B.

    2016-04-01

    Atherosclerosis is a narrowing of the arteries caused by an increase of atheromatous plaque: material formed by macrophage cells containing cholesterol and fatty acids, calcium and a variable amount of fibrous connective tissue. The elation between vulnerable plaques and cardiovascular events can be determined using plaque biomarkers. In this work, atherosclerotic plaques stained with different molar ratios of europium, in a potential plaque biomarker, europium tetracycline complex, were studied by fluorescence microscopy. The tetracycline antibiotic used was chlortetracycline. The growth of atherosclerotic plaque was followed during 60 days in New Zealand rabbits divided in two groups: an experimental group (EG), with nine animals and a control group (CG) with three animals. The animals in the EG received a diet with 1% of cholesterol and the animals of GC received a normal diet. The aortic arch of the animals with 60 days were cut in the vertical plane in 6 μm thick slices, which were mounted on glass slides and stained with hematoxylin an eosin and europium chlortetracycline complex (EuCTc). The fluorescence images were obtained exciting the EuCTc absorption band with a filter cube D (BP 355 - 425) and the emission was collected with a LP 470 suppression filter. Light intensity, detector gain and acquisition time were fixed for comparisons. The 20× magnified images were collected with 12 bit (or 4096 gray tones) resolution. The mean value of gray scale for each molar ratio of EuCTc was different, indicating that the complex interacts with the components of atherosclerotic plaque and the best molar ratio was 1.5 EuCTc. These results indicate the potential use of the EuCTc biomarker for atherosclerotic plaque characterization.

  19. Modular organisation of inducer recognition and allostery in the tetracycline repressor.

    Science.gov (United States)

    Werten, Sebastiaan; Schneider, Julia; Palm, Gottfried Julius; Hinrichs, Winfried

    2016-06-01

    Induction of the tetracycline repressor (TetR) results from antibiotic-dependent changes in the relative positioning of the DNA-binding domains within the promoter-associated repressor dimer, but the key determinants of this allosteric effect remain poorly characterised. Intriguingly, previous mutational analyses of the tetracycline-interacting site revealed a lack of correlation between residual affinity and induction propensity, suggesting that some of the residues in contact with the antibiotic primarily act in ligand recognition and retention, whereas others are required to transmit the allosteric signal. Here, we provide a structural basis for these observations via crystallographic analysis of the point mutants N82A, H100A, T103A and E147A in complex with the inducer 5a,6-anhydrotetracycline. In conjunction with the available functional data, the four structures demonstrate that a trigger-like movement of the region between helices α6 and α7 towards and into the binding site plays a decisive role in the intramolecular communication process. In sharp contrast, residues lining the binding cavity proper have little or no influence on the allosteric mechanism as such. This nearly complete physical separation of ligand recognition and allostery will have allowed diverging TetR-like repressors to bind novel effectors while the existing induction mechanism remained intact. Consequently, the modularity described here may have been a key factor in the evolutionary success of the widespread and highly diversified repressor class. Structural data are available in the Protein Data Bank under the accession numbers 5FKK, 5FKL, 5FKM, 5FKN and 5FKO. © 2016 Federation of European Biochemical Societies.

  20. Expansion of the Tetracycline-Dependent Regulation Toolbox for Helicobacter pylori

    Science.gov (United States)

    Sehnal, Miriam; Liao, Tingting; Stubbs, Keith A.; Marshall, Barry J.; Benghezal, Mohammed

    2015-01-01

    In an effort to gain greater understanding of the biology and infection processes of Helicobacter pylori, we have expanded the functionality of the tetracycline-dependent gene regulation (tet) system to provide more improved and versatile genetic control and facilitate the generation of conditional mutants to study essential genes. Second-generation tetracycline-responsive H. pylori uPtetO5 promoters were based on the mutated core ureA promoter. Single point mutations at either the ribosomal binding site or the start codon were introduced to shift the regulatory range of three uPtetO5 derivatives. All promoters were tested for regulation by TetR and revTetR using dapD, a gene essential to peptidoglycan biosynthesis, as a reporter. All tet promoters were effectively regulated by both TetR and revTetR, and their regulation windows overlapped so as to cover a broad range of expression levels. tet promoters uPtetO5m1 and uPtetO5m2 could be sufficiently silenced by both TetR and revTetR so that the conditional mutants could not grow in the absence of diaminopimelic acid (DAP). Furthermore, through the use of these inducible promoters, we reveal that insufficient DAP biosynthesis results in viable cells with altered morphology. Overall, the development and optimization of tet regulation for H. pylori will not only permit the study of essential genes but also facilitate investigations into gene dosage effects on H. pylori physiology. PMID:26362986

  1. Controlled Osteogenic Differentiation of Mouse Mesenchymal Stem Cells by Tetracycline-Controlled Transcriptional Activation of Amelogenin.

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    Fangfang Wang

    Full Text Available Regenerative dental therapies for bone tissues rely on efficient targeting of endogenous and transplanted mesenchymal stem cells (MSCs to guide bone formation. Amelogenin is the primary component of Emdogain, which is used to regenerate periodontal defects; however, the mechanisms underlying the therapeutic effects on alveolar bone remain unclear. The tetracycline (Tet-dependent transcriptional regulatory system is a good candidate to investigate distinct roles of genes of interest during stem cell differentiation. Here, we investigated amelogenin-dependent regulation of osteogenesis in MSCs by establishing a Tet-controlled transcriptional activation system. Clonal mouse bone marrow-derived MSCs were lentivirally transduced with the Tet repressor (TetR expression vector followed by drug selection to obtain MSCs constitutively expressing TetR (MSCs-TetR. Expression vectors that contained the Tet operator and amelogenin-coding (Amelx cDNA fragments were constructed using the Gateway system and lentivirally introduced into MSCs-TetR to generate a Tet regulation system in MSCs (MSCs-TetR/Amelx. MSCs-TetR/Amelx significantly overexpressed the Amelx gene and protein in the presence of the tetracycline derivative doxycycline. Concomitant expression of osterix, bone sialoprotein (BSP, osteopontin, and osteocalcin was modulated by addition or removal of doxycycline under osteogenic guidance. During osteogenic induction, MSCs-TetR/Amelx treated with doxycycline showed significantly increased gene expression of osterix, type I collagen, BSP, and osteocalcin in addition to increased alkaline phosphatase activity and mineralized nodule formation. Enhanced extracellular matrix calcification was observed when forced Amelx expression commenced at the early stage but not at the intermediate or late stages of osteogenesis. These results suggest that a Tet-controlled Amelx gene regulation system for mouse MSCs was successfully established, in which transcriptional

  2. Influence of Soil Use on Prevalence of Tetracycline, Streptomycin, and Erythromycin Resistance and Associated Resistance Genes

    Science.gov (United States)

    Rzeczycka, Marzenna; Miernik, Antoni; Krawczyk-Balska, Agata; Walsh, Fiona; Duffy, Brion

    2012-01-01

    This study examined differences in antibiotic-resistant soil bacteria and the presence and quantity of resistance genes in soils with a range of management histories. We analyzed four soils from agricultural systems that were amended with manure from animals treated with erythromycin and exposed to streptomycin and/or oxytetracycline, as well as non-manure-amended compost and forest soil. Low concentrations of certain antibiotic resistance genes were detected using multiplex quantitative real-time PCR (qPCR), with tet(B), aad(A), and str(A) each present in only one soil and tet(M) and tet(W) detected in all soils. The most frequently detected resistance genes were tet(B), tet(D), tet(O), tet(T), and tet(W) for tetracycline resistance, str(A), str(B), and aac for streptomycin resistance, and erm(C), erm(V), erm(X), msr(A), ole(B), and vga for erythromycin resistance. Transposon genes specific for Tn916, Tn1549, TnB1230, Tn4451, and Tn5397 were detected in soil bacterial isolates. The MIC ranges of isolated bacteria for tetracycline, streptomycin, and erythromycin were 8 to >256 μg/ml, 6 to >1,024 μg/ml, and 0.094 to >256 μg/ml, respectively. Based on 16S rRNA gene similarity, isolated bacteria showed high sequence identity to genera typical of soil communities. Bacteria with the highest MICs were detected in manure-amended soils or soils from agricultural systems with a history of antibiotic use. Non-manure-amended soils yielded larger proportions of antibiotic-resistant bacteria, but these had lower MICs, carried fewer antibiotic resistance genes, and did not display multidrug resistance (MDR). PMID:22203596

  3. Reversed-phase ion-pair chromatographic analysis of tetracycline antibiotics. Application to discolored teeth.

    Science.gov (United States)

    Tanase, S; Tsuchiya, H; Yao, J; Ohmoto, S; Takagi, N; Yoshida, S

    1998-03-20

    A high-performance liquid chromatographic method with diode array detection was developed to simultaneously separate tetracycline antibiotics and applied to the analysis of discolored teeth. By a reversed-phase ion-pair chromatographic system using pentanesulfonate as a counter ion, minocycline, oxytetracycline, tetracycline and demeclocycline were eluted in this order, and they showed base-line separation within 9 min. When using oxytetracycline as an internal standard, the quantitative ranges were between 2.5 ng/ml and 7.5 microg/ml. Powdered dentine (10 mg) and enamel (40 mg) prepared from discolored primary teeth were sonicated in 0.25 ml of 10 mM HCl containing oxytetracycline (0.75 microg/ml) and 50 mM EDTA-2Na, thereafter the supernatants were chromatographed. Eluates from both discolored tooth samples were identified as minocycline based on diode array spectra of their peaks, while minocycline was not detected in any samples from nondiscolored normal teeth, indicating that discoloration of the tested teeth was due to minocycline incorporated into dentine and enamel. Replicate quantitative analyses of the identical tooth substances showed that intra- and inter-assay C.V.s were 2.63 and 4.95% for dentine, and 5.42 and 10.88% for enamel. Application of the developed method to nine discolored teeth revealed that the incorporated minocycline ranged from 20.13 to 84.62 ng/mg of dentine and 0.89 to 7.87 ng/mg of enamel.

  4. Tetracycline Resistance in the Subsurface of a Poultry Farm: Influence of Poultry Wastes

    Science.gov (United States)

    You, Y.; Ball, W. P.; Ward, M. J.; Hilpert, M.

    2007-12-01

    Concentrated animal feeding operations (CAFOs) are considered to be important man-made reservoir of antibiotic resistant bacteria. Using the electromagnetic induction (EMI) method of geophysical characterization, we measured the apparent subsurface electrical conductivity (ECa) at a CAFO site in order to assess the movement of pollutants associated with animal waste. The map of ECa and other available data suggest that (1) soil surrounding a poultry litter storage shed is contaminated by poultry waste, (2) a contamination plume in the subsurface emanates from that shed, and (3) the development of that plume is due to groundwater flow. We focused on understanding the spread of tetracycline resistance (Tc\\tiny R), because tetracycline is one of the most frequently used antibiotics in food animal production and therefore probably used at our field site. Microbiological experiments show the presence of Tc\\tiny R bacteria in the subsurface and indicate higher concentrations in the top soil than in the aquifer. Environmental DNA was extracted to identify CAFO- associated Tc\\tiny R genes and to explore a link between the presence of Tc\\tiny R and CAFO practices. A "shot-gun" cloning approach is under development to target the most prevalent Tc\\tiny R gene. This gene will be monitored in future experiments, in which we will study the transmission of Tc\\tiny R to naive E.~coli under selective pressure of Tc. Experimental results will be used to develop a mathematical/numerical model in order to describe the transmission process and to subsequently make estimates regarding the large-scale spread of antibiotic resistance.

  5. Influence of soil use on prevalence of tetracycline, streptomycin, and erythromycin resistance and associated resistance genes.

    Science.gov (United States)

    Popowska, Magdalena; Rzeczycka, Marzenna; Miernik, Antoni; Krawczyk-Balska, Agata; Walsh, Fiona; Duffy, Brion

    2012-03-01

    This study examined differences in antibiotic-resistant soil bacteria and the presence and quantity of resistance genes in soils with a range of management histories. We analyzed four soils from agricultural systems that were amended with manure from animals treated with erythromycin and exposed to streptomycin and/or oxytetracycline, as well as non-manure-amended compost and forest soil. Low concentrations of certain antibiotic resistance genes were detected using multiplex quantitative real-time PCR (qPCR), with tet(B), aad(A), and str(A) each present in only one soil and tet(M) and tet(W) detected in all soils. The most frequently detected resistance genes were tet(B), tet(D), tet(O), tet(T), and tet(W) for tetracycline resistance, str(A), str(B), and aac for streptomycin resistance, and erm(C), erm(V), erm(X), msr(A), ole(B), and vga for erythromycin resistance. Transposon genes specific for Tn916, Tn1549, TnB1230, Tn4451, and Tn5397 were detected in soil bacterial isolates. The MIC ranges of isolated bacteria for tetracycline, streptomycin, and erythromycin were 8 to >256 μg/ml, 6 to >1,024 μg/ml, and 0.094 to >256 μg/ml, respectively. Based on 16S rRNA gene similarity, isolated bacteria showed high sequence identity to genera typical of soil communities. Bacteria with the highest MICs were detected in manure-amended soils or soils from agricultural systems with a history of antibiotic use. Non-manure-amended soils yielded larger proportions of antibiotic-resistant bacteria, but these had lower MICs, carried fewer antibiotic resistance genes, and did not display multidrug resistance (MDR).

  6. Distribution of tetracycline and streptomycin resistance genes and class 1 integrons in Enterobacteriaceae isolated from dairy and nondairy farm soils.

    Science.gov (United States)

    Srinivasan, Velusamy; Nam, Hyang-Mi; Sawant, Ashish A; Headrick, Susan I; Nguyen, Lien T; Oliver, Stephen P

    2008-02-01

    The prevalence of selected tetracycline and streptomycin resistance genes and class 1 integrons in Enterobacteriaceae (n = 80) isolated from dairy farm soil and nondairy soils was evaluated. Among 56 bacteria isolated from dairy farm soils, 36 (64.3%) were resistant to tetracycline, and 17 (30.4%) were resistant to streptomycin. Lower frequencies of tetracycline (9 of 24 or 37.5%) and streptomycin (1 of 24 or 4.2%) resistance were observed in bacteria isolated from nondairy soils. Bacteria (n = 56) isolated from dairy farm soil had a higher frequency of tetracycline resistance genes including tetM (28.6%), tetA (21.4%), tetW (8.9%), tetB (5.4%), tetS (5.4%), tetG (3.6%), and tetO (1.8%). Among 24 bacteria isolated from nondairy soils, four isolates carried tetM, tetO, tetS, and tetW in different combinations; whereas tetA, tetB, and tetG were not detected. Similarly, a higher prevalence of streptomycin resistance genes including strA (12.5%), strB (12.5%), ant(3'') (12.5), aph(6)-1c (12.5%), aph(3'') (10.8%), and addA (5.4%) was detected in bacteria isolated from dairy farm soils than in nondairy soils. None of the nondairy soil isolates carried aadA gene. Other tetracycline (tetC, tetD, tetE, tetK, tetL, tetQ, and tetT) and streptomycin (aph(6)-1c and ant(6)) resistance genes were not detected in both dairy and nondairy soil isolates. A higher distribution of multiple resistance genes was observed in bacteria isolated from dairy farm soil than in nondairy soil. Among 36 tetracycline- and 17 streptomycin-resistant isolates from dairy farm soils, 11 (30.6%) and 9 (52.9%) isolates carried multiple resistance genes encoding resistance to tetracycline and streptomycin, respectively, which was higher than in bacteria isolated from nondairy soils. One strain each of Citrobacter freundii and C. youngae isolated from dairy farm soils carried class 1 integrons with different inserted gene cassettes. Results of this small study suggest that the presence of multiple

  7. Healing Potentials of Oral Moringa Oleifera Leaves Extract and Tetracycline on Methicillin Resistant Staphylococcus Aureus Infected Wounds of Wistar rats.

    Science.gov (United States)

    Eyarefe, Oghenemega D; Idowu, Aderayo; Afolabi, Jeremiah M

    2015-12-20

    The effects of oral dose of aqueous extract of Moringa oleifera and tetracycline antibiotics on cutaneous wounds infected with Staphylococcus aureus were studied in eighteen adult wistar rats (159±31.5g) randomized into three groups: Group A, n = 6, Moringa oleifera-(300 mg/kg). Group B, n = 6, tetracycline (9.4 mg/kg) and Group C, n = 6, Sterile water (control). Six millimetres diameter nape wound, created on each rat under 2% xylazine (5 mg/kg) and 5% ketamine (35 mg/kg), was contaminated with Staphylococcus aureus (108 Colony Forming Unit (CFU). Following infection, treatment was commenced with daily oral dose of test preparations and the wounds were evaluated every other day i.e., day 3, 5, 7, 9, 11, 13 and 15 for wetness (wound exudation), wound edge oedema, hyperaemia, granulation tissues and contraction (diameter). Severe wound exudation existed in all the groups between days 0-3 (p = 1.00). A significantly less wound exudation was observed at days 3-5 (p = 0.000) and 5-9 (p = 0.003) (ControlMoringa). Wound edge oedema was significantly less on days 5-9 (p = 0.000) and 9-15 (p = 0.001) (ControlMoringaMoringa Moringa> Tetracycline). Differences in wound diameter was not significant except at days 5-9 (p = 0.013) (Control> Moringa >Tetracycline). Oral doses of Moringa oleifera extract (300mg/kg) and tetracycline (9.4mg/kg) are not effective as antimicrobial or immune-boosting agents to enhance healing of wounds infected with Staphylococcus aureus and hence not recommended for rapid clearance of Staphylococcus aureus infected wounds.

  8. The Identification of Intrinsic Chloramphenicol and Tetracycline Resistance Genes in Members of the Bacillus cereus Group (sensu lato)

    Science.gov (United States)

    Glenwright, Helen; Pohl, Susanne; Navarro, Ferran; Miro, Elisenda; Jiménez, Guillermo; Blanch, Anicet R.; Harwood, Colin R.

    2017-01-01

    Bacillus toyonensis strain BCT-7112T (NCIMB 14858T) has been widely used as an additive in animal nutrition for more than 30 years without reports of adverse toxigenic effects. However, this strain is resistant to chloramphenicol and tetracycline and it is generally considered inadvisable to introduce into the food chain resistance determinants capable of being transferred to other bacterial strains, thereby adding to the pool of such determinants in the gastro-enteric systems of livestock species. We therefore characterized the resistance phenotypes of this strain and its close relatives to determine whether they were of recent origin, and therefore likely to be transmissible. To this end we identified the genes responsible for chloramphenicol (catQ) and tetracycline (tetM) resistance and confirmed the presence of homologs in other members of the B. toyonensis taxonomic unit. Unexpectedly, closely related strains encoding these genes did not exhibit chloramphenicol and tetracycline resistance phenotypes. To understand the differences in the behaviors, we cloned and expressed the genes, together with their upstream regulatory regions, into Bacillus subtilis. The data showed that the genes encoded functional proteins, but were expressed inefficiently from their native promoters. B. toyonensis is a taxonomic unit member of the Bacillus cereus group (sensu lato). We therefore extended the analysis to determine the extent to which homologous chloramphenicol and tetracycline resistance genes were present in other species within this group. This analysis revealed that homologous genes were present in nearly all representative species within the B. cereus group (sensu lato). The absence of known transposition elements and the observations that they are found at the same genomic locations, indicates that these chloramphenicol and tetracycline resistance genes are of ancient origin and intrinsic to this taxonomic group, rather than recent acquisitions. In this context we

  9. β-Lactams and Florfenicol Antibiotics Remain Bioactive in Soils while Ciprofloxacin, Neomycin, and Tetracycline Are Neutralized▿

    Science.gov (United States)

    Subbiah, Murugan; Mitchell, Shannon M.; Ullman, Jeffrey L.; Call, Douglas R.

    2011-01-01

    It is generally assumed that antibiotic residues in soils select for antibiotic-resistant bacteria. This assumption was tested by separately adding 10 different antibiotics (≥200 ppm) to three soil-water slurries (silt-loam, sand-loam, and sand; 20% soil [wt/vol]) and incubating mixtures for 24 h at room temperature. The antibiotic activity of the resultant supernatant was assessed by culturing a sensitive Escherichia coli strain in the filter-sterilized supernatant augmented with Luria-Bertani broth. We found striking differences in the abilities of supernatants to suppress growth of the indicator E. coli. Ampicillin, cephalothin, cefoxitin, ceftiofur, and florfenicol supernatants completely inhibited growth while bacterial growth was uninhibited in the presence of neomycin, tetracycline, and ciprofloxacin supernatants. High-performance liquid chromatography (HPLC) analysis demonstrated that cefoxitin and florfenicol were almost completely retained in the supernatants, whereas tetracycline and ciprofloxacin were mostly removed. Antibiotic dissipation in soil, presumably dominated by adsorption mechanisms, was sufficient to neutralize 200 ppm of tetracycline; this concentration is considerably higher than reported contamination levels. Soil pellets from the tetracycline slurries were resuspended in a minimal volume of medium to maximize the interaction between bacteria and soil particles, but sensitive bacteria were still unaffected by tetracycline (P = 0.6). Thus, residual antibiotics in soil do not necessarily exert a selective pressure, and the degree to which the pharmaceutical remains bioactive depends on the antibiotic. Efforts to control antibiotic contamination would be better directed toward compounds that retain biological activity in soils (e.g., cephalosporins and florfenicol) because these are the antibiotics that could exert a selective pressure in the environment. PMID:21856822

  10. Fibrin clot adhesion to root surface treated with tetracycline hydrochloride and ethylenediaminetetraacetic acid: A scanning electron microscopic study

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    Chandran Preeja

    2013-01-01

    Full Text Available Background: Connective tissue attachment following periodontal regenerative surgery is directly related to the attachment of fibrin clot on to the root surface during early wound healing events.The adhesion of fibrin clot to the root surface affected by periodontal disease depends on the biologic acceptance of the root surface which can be accomplished by various root conditioning procedures during periodontal therapy. The present in vitro study has been designed to evaluate and compare the degree of fibrin clot adhesion to root surfaces treated with root conditioning agents tetracycline hydrochloride and ethylenediaminetetraacetic acid (EDTA. Materials and Methods: A total of 30 dentin blocks are divided into three groups and treated with tetracycline hydrochloride, EDTA and phosphate buffered saline and a drop of blood is added to each dentin block. The dentin blocks are then prepared for scanning electron microscopic analysis and examined for the degree of fibrin network frmation and entrapped erythrocytes. Results: The degree of fibrin clot adhesion was highest with tetracycline hydrochloride group, then with control group and least with EDTA treated group. Conclusion: According to the results of the present study, root conditioning with tetracycline hydrochloride produces a biologically acceptable root surface with enhanced fibrin clot adhesion, which is a critical step in early wound healing process. EDTA gel appears less effective in producing a root surface necessary for the adhesion of fibrin clot. The control without any root conditioning procedure showed poor fibrin clot adhesion when compared to tetracycline treated group, but when compared to EDTA treated group the fibrin clot adhesion was slightly better.

  11. Rescue Therapy for Helicobacter pylori Eradication: A Randomized Non-Inferiority Trial of Amoxicillin or Tetracycline in Bismuth Quadruple Therapy.

    Science.gov (United States)

    Chen, Qi; Zhang, Wei; Fu, Qingyan; Liang, Xiao; Liu, Wenzhong; Xiao, Shudong; Lu, Hong

    2016-12-01

    To compare the efficacy and safety of bismuth-containing quadruple therapy with tetracycline or amoxicillin for rescue treatment of Helicobacter pylori. The study was a non-inferiority trial of H. pylori eradication with at least two previous treatment failures. Subjects were randomized to receive 14-day therapy with b.i.d. lansoprazole 30 mg and bismuth 220 mg, plus metronidazole 400 mg q.i.d and amoxicillin 1 g t.i.d (amoxicillin group) or tetracycline 500 mg q.i.d (tetracycline group). Antimicrobial susceptibility was assessed by the agar-dilution method. Primary outcome was H. pylori eradication at 6 weeks after treatment. In all, 312 subjects were randomized, 13 were lost to follow-up; 29 violated the protocol. The intention-to-treat, per-protocol, and modified intention-to-treat eradication rates were (amoxicillin) 88.5% (138/156, 95% confidence interval (CI) 83.4-93.5%), 93.7% (133/142, 95% CI 89.7-97.7%), and 92.6% (138/149, 95% CI 88.4-96.8%). With tetracycline, they were 87.2% (136/156, 95% CI 81.9-92.4%), 95.3% (122/128, 95% CI 91.7-99.0%), and 90.7% (136/150, 95% CI 86.0-95.3%). Amoxicillin-, tetracycline-, and metronidazole-resistant rates were 8.3, 1.0, and 87.8%, respectively. Non-inferiority was confirmed (Pbismuth-containing quadruple therapy with metronidazole and amoxicillin is an alternative to classical bismuth quadruple therapy for H. pylori rescue treatment as it provides similar eradication with superior safety and compliance.

  12. Molecular characterization of a novel mosaic tet(S/M) gene encoding tetracycline resistance in foodborne strains of Streptococcus bovis.

    Science.gov (United States)

    Barile, Simona; Devirgiliis, Chiara; Perozzi, Giuditta

    2012-09-01

    The presence of antibiotic-resistance (AR) genes in foodborne bacteria of enteric origin represents a relevant threat to human health in the case of opportunistic pathogens, which can reach the human gut through the food chain. Streptococcus bovis is a human opportunistic pathogen often associated with infections in immune-compromised or cancer patients, and it can also be detected in the environment, including fermented foods. We have focused on the molecular characterization of a tetracycline (Tet)-resistance gene present in 39 foodborne isolates of S. bovis phenotypically resistant to this drug. The gene was identified as a novel tet(S/M) fusion, encoding a mosaic protein composed of the N-terminal 33 amino acids of Tet(S), in-frame with the Tet(M) coding sequence. Heterologous expression of the mosaic gene was found to confer Tet resistance upon Escherichia coli recipients. Moreover, the tet(S/M) gene was found to be transcriptionally inducible by Tet under the endogenous tet(S) promoter in both S. bovis and E. coli. Nucleotide sequencing of the surrounding genomic region of 16.2 kb revealed large blocks of homology with the genomes of Streptococcus infantarius and Lactococcus lactis. A subregion of about 4 kb containing mosaic tet(S/M) was flanked by two copies of the IS1216 mobile element. PCR amplification with primers directed outwards from the tet(S/M) gene identified the presence of a 4.3 kb circular form corresponding to the intervening chromosomal region between the two IS1216 elements, but lacking a replication origin. The circular element shared extensive overall homology with a region of the multidrug-resistance plasmid pK214 from Lc. lactis, containing tet(S), as well as the IS1216 transposase-containing element and intervening non-coding sequences. Linear reconstruction of the insertion events likely to have occurred within this genomic region, inferred from sequence homology, provides further evidence of the chromosomal rearrangements that drive

  13. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1994-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October - December 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  14. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-11-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July - September 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  15. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1989-06-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1989) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. Also included are a number of enforcement actions that had been previously resolved but not published in this NUREG. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  16. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-05-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1990) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. Also included are a number of enforcement actions that had been previously resolved but not published in this NUREG. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  17. Assessment of the Impact of Potential Tetracycline Exposure on the Phenotype of Aedes aegypti OX513A: Implications for Field Use.

    Directory of Open Access Journals (Sweden)

    Zoe Curtis

    2015-08-01

    Full Text Available Aedes aegypti is the primary vector of dengue fever, a viral disease which has an estimated incidence of 390 million infections annually. Conventional vector control methods have been unable to curb the transmission of the disease. We have previously reported a novel method of vector control using a tetracycline repressible self-limiting strain of Ae. aegypti OX513A which has achieved >90% suppression of wild populations.We investigated the impact of tetracycline and its analogues on the phenotype of OX513A from the perspective of possible routes and levels of environmental exposure. We determined the minimum concentration of tetracycline and its analogues that will allow an increased survivorship and found these to be greater than the maximum concentration of tetracyclines found in known Ae. aegypti breeding sites and their surrounding areas. Furthermore, we determined that OX513A parents fed tetracycline are unable to pre-load their progeny with sufficient antidote to increase their survivorship. Finally, we studied the changes in concentration of tetracycline in the mass production rearing water of OX513A and the developing insect.Together, these studies demonstrate that potential routes of exposure of OX513A individuals to tetracycline and its analogues in the environment are not expected to increase the survivorship of OX513A.

  18. Mirror neurons and their clinical relevance.

    Science.gov (United States)

    Rizzolatti, Giacomo; Fabbri-Destro, Maddalena; Cattaneo, Luigi

    2009-01-01

    One of the most exciting events in neurosciences over the past few years has been the discovery of a mechanism that unifies action perception and action execution. The essence of this 'mirror' mechanism is as follows: whenever individuals observe an action being done by someone else, a set of neurons that code for that action is activated in the observers' motor system. Since the observers are aware of the outcome of their motor acts, they also understand what the other individual is doing without the need for intermediate cognitive mediation. In this Review, after discussing the most pertinent data concerning the mirror mechanism, we examine the clinical relevance of this mechanism. We first discuss the relationship between mirror mechanism impairment and some core symptoms of autism. We then outline the theoretical principles of neurorehabilitation strategies based on the mirror mechanism. We conclude by examining the relationship between the mirror mechanism and some features of the environmental dependency syndromes.

  19. The gut as reservoir of antibiotic resistance: microbial diversity of tetracycline resistance in mother and infant.

    Directory of Open Access Journals (Sweden)

    Lisbeth E de Vries

    Full Text Available The microbiota in the human gastrointestinal tract (GIT is highly exposed to antibiotics, and may be an important reservoir of resistant strains and transferable resistance genes. Maternal GIT strains can be transmitted to the offspring, and resistances could be acquired from birth. This is a case study using a metagenomic approach to determine the diversity of microorganisms conferring tetracycline resistance (Tc(r in the guts of a healthy mother-infant pair one month after childbirth, and to investigate the potential for horizontal transfer and maternal transmission of Tc(r genes. Fecal fosmid libraries were functionally screened for Tc(r, and further PCR-screened for specific Tc(r genes. Tc(r fosmid inserts were sequenced at both ends to establish bacterial diversity. Mother and infant libraries contained Tc(r, although encoded by different genes and organisms. Tc(r organisms in the mother consisted mainly of Firmicutes and Bacteroidetes, and the main gene detected was tet(O, although tet(W and tet(X were also found. Identical Tc(r gene sequences were present in different bacterial families and even phyla, which may indicate horizontal transfer within the maternal GIT. In the infant library, Tc(r was present exclusively in streptococci carrying tet(M, tet(L and erm(T within a novel composite transposon, Tn6079. This transposon belongs to a family of broad host range conjugative elements, implying a potential for the joint spread of tetracycline and erythromycin resistance within the infant's gut. In addition, although not found in the infant metagenomic library, tet(O and tet(W could be detected in the uncloned DNA purified from the infant fecal sample. This is the first study to reveal the diversity of Tc(r bacteria in the human gut, to detect a likely transmission of antibiotic resistance from mother to infant GITs and to indicate the possible occurrence of gene transfers among distantly related bacteria coinhabiting the GIT of the same

  20. Microbial Community Structure of a Leachfield Soil: Response to Intermittent Aeration and Tetracycline Addition

    Directory of Open Access Journals (Sweden)

    David A. Potts

    2013-04-01

    Full Text Available Soil-based wastewater treatment systems, or leachfields, rely on microbial processes for improving the quality of wastewater before it reaches the groundwater. These processes are affected by physicochemical system properties, such as O2 availability, and disturbances, such as the presence of antimicrobial compounds in wastewater. We examined the microbial community structure of leachfield mesocosms containing native soil and receiving domestic wastewater under intermittently-aerated (AIR and unaerated (LEACH conditions before and after dosing with tetracycline (TET. Community structure was assessed using phospholipid fatty acid analysis (PLFA, analysis of dominant phylotypes using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR–DGGE, and cloning and sequencing of 16S rRNA genes. Prior to dosing, the same PLFA biomarkers were found in soil from AIR and LEACH treatments, although AIR soil had a larger active microbial population and higher concentrations for nine of 32 PLFA markers found. AIR soil also had a larger number of dominant phylotypes, most of them unique to this treatment. Dosing of mesocosms with TET had a more marked effect on AIR than LEACH soil, reducing the size of the microbial population and the number and concentration of PLFA markers. Dominant phylotypes decreased by ~15% in response to TET in both treatments, although the AIR treatment retained a higher number of phylotypes than the LEACH treatment. Fewer than 10% of clones were common to both OPEN ACCESS Water 2013, 5 506 AIR and LEACH soil, and fewer than 25% of the clones from either treatment were homologous with isolates of known genus and species. These included human pathogens, as well as bacteria involved in biogeochemical transformations of C, N, S and metals, and biodegradation of various organic contaminants. Our results show that intermittent aeration has a marked effect on the size and structure of the microbial community that develops in

  1. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  2. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-02-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1990) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  3. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-08-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  4. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  5. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-07-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April-June 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  6. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-12-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  7. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-06-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  8. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-05-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  9. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-11-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1990) and includes copies of letters, notices, and orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  10. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-11-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  11. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1989) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  12. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1989-12-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1989) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  13. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-05-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  14. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-09-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  15. Control-Relevant Upscaling

    NARCIS (Netherlands)

    Vakili Ghahani, S.A.

    2010-01-01

    An ‘upscaling/order-reduction’ solution transfers the relevant features of a geological model to a flow simulation model such that cost-efficient simulation, prediction and control of the fluid flow in an oil reservoir become feasible. In addition to the computational issues, in most reservoir

  16. Is Information Still Relevant?

    Science.gov (United States)

    Ma, Lia

    2013-01-01

    Introduction: The term "information" in information science does not share the characteristics of those of a nomenclature: it does not bear a generally accepted definition and it does not serve as the bases and assumptions for research studies. As the data deluge has arrived, is the concept of information still relevant for information…

  17. Relevance and Definition.

    Science.gov (United States)

    Watson, Rita

    1995-01-01

    Examined whether the use of superordinate terms in 206 children's definitions is predictable by relevance theory. Children (ages 5-10) gave definitions for 16 basic-level words and 4 superordinate words from natural kind and artifact semantic domains. Superordinate terms were used more frequently when they supported more inferences. Findings…

  18. [Effect of the crystallization conditions of tetracycline base on the properties of the powders and drug forms obtained. The dependence of the degree of dispersion of tetracycline base on the crystallization conditions].

    Science.gov (United States)

    Lin'kov, G I; Zhukovskaia, S A; Dzhabarov, D N; Nabokov, V S

    1977-09-01

    Characteristics of the powder dispersity of tetracycline base samples prepared by directed crystallization with variation of the process conditions were determined by the sedimentation method. It was found that the speed of the solution agitation had the maximum effect on the level and nature of the dispersity. The rate of the solution temperature and pH changing during the crystallization process had also a significant effect at low agitation speed.

  19. Photocatalytic degradation of tetracycline by Ti-MCM-41 prepared at room temperature and biotoxicity of degradation products

    Science.gov (United States)

    Zhou, Kefu; Xie, Xiao-Dan; Chang, Chang-Tang

    2017-09-01

    Ti-doped MCM-41 with different Si/Ti molar ratios was prepared at room temperature to degrade tetracycline antibiotics in aqueous solution. The Ti was doped into the skeleton structure of MCM-41. The photocatalytic activity of Ti-doped MCM-41 was investigated. The optimal catalyst had Si/Ti molar ratio of 25 and over 99% removal of oxytetracycline in 150 min, and the removal could maintain 98% after 5 reuses. Ions and soluble organic matters in natural water affected the degradation reaction when Ti-doped MCM-41 was used to treat simulated wastewater of chicken farms. The degradation products of oxytetracycline, tetracycline and chlortetracycline were detected by Escherichia coli DH5α and HPLC-MS/MS. No intermediate product with higher toxicity was detected.

  20. Pharmacodynamic modelling of in vitro activity of tetracycline against a representative, naturally occurring population of porcine Escherichia coli

    DEFF Research Database (Denmark)

    Ahmad, Amais; Zachariasen, Camilla; Christiansen, Lasse Engbo

    2015-01-01

    of Escherichia coli representative of those found in the Danish pig population, we compared the growth of 50 randomly selected strains. The observed net growth rates were used to describe the in vitro pharmacodynamic relationship between drug concentration and net growth rate based on E max model with three...... parameters: maximum net growth rate (α max ); concentration for a half-maximal response (E max ); and the Hill coefficient (γ). The net growth rate in the absence of antibiotic did not differ between susceptible and resistant isolates (P = 0.97). The net growth rate decreased with increasing tetracycline...... text] between susceptible and resistant strains in the absence of a drug was not different. EC 50 increased linearly with MIC on a log-log scale, and γ was different between susceptible and resistant strains. The in vitro model parameters described the inhibition effect of tetracycline on E. coli when...

  1. The Effect of Kanamycin and Tetracycline on Growth and Photosynthetic Activity of Two Chlorophyte Algae

    Directory of Open Access Journals (Sweden)

    Khawaja Muhammad Imran Bashir

    2016-01-01

    Full Text Available Antibiotics are routinely used in microalgae culture screening, stock culture maintenance, and genetic transformation. By studying the effect of antibiotics on microalgae growth, we can estimate the least value to inhibit growth of undesired pathogens in algal culture. We studied the effect of kanamycin and tetracycline on the growth and photosynthetic activity of two chlorophyte microalgae, Dictyosphaerium pulchellum and Micractinium pusillum. We measured CFU mL−1 on agar plates, optical density, fluorescence yields, and photosynthetic inhibition. Our results showed a significant effect of kan and tet on the tested microalgae species except tet, which showed a minor effect on M. pusillum. Both antibiotics are believed to interact with the protein synthesis machinery; hence, the inhibitory effect of the tested antibiotics was further confirmed by isolation and quantification of the whole cell protein. A significant reduction in protein quantity was observed at concentrations more than 5 mg L−1, except M. pusillum, which showed only a slight reduction in protein quantity even at the maximum tested concentration of tet (30 mg L−1. This study can further aid in aquaculture industry, for the maintenance of the microalgae stock cultures and it can also help the microalgae genetic engineers in the construction of molecular markers.

  2. Efficient tetracycline adsorption and photocatalytic degradation of rhodamine B by uranyl coordination polymer

    Science.gov (United States)

    Ren, Ya-Nan; Xu, Wei; Zhou, Lin-Xia; Zheng, Yue-Qing

    2017-07-01

    Two mixed uranyl-cadmium malonate coordination polymers [(UO2)2Cd(H-bipy)2(mal)4(H2O)2]·4H2O 1 and [(UO2)Cd(bipy)(mal)2]·H2O 2 (H2mal = malonic acid, bipy =4,4‧-bipyridine) have been synthesized in room temperature. Compound 1 represents a one-dimensional (1D) chain assembly of Cd(II) ions, uranyl centers and malonate ligands. Compound 2 exhibits a two-dimensional (2D) 2D +2D → 3D polycatenated framework based on inclined interlocked 2D 44 sql grids. The two compounds have been characterized by elemental analysis, IR and UV-vis spectroscopy, thermal analysis, powder X-ray diffraction and photoluminescence spectroscopy. And the ferroelectric property of 2 also has been studied. Moreover, compound 2 exhibits good photocatalytic activity for dye degradation under UV light and is excellent adsorbent for removing tetracycline antibiotics in the aqueous solution.

  3. Efficient removal of tetracycline with KOH-activated graphene from aqueous solution.

    Science.gov (United States)

    Ma, Jie; Sun, Yiran; Yu, Fei

    2017-11-01

    Activated graphene absorbents with high specific surface area (SSA) were prepared by an easy KOH-activated method, and were applied in absorbing antibiotics, such as tetracycline (TC). After activation, many micropores were introduced to graphene oxide sheets, leading to higher SSA and many new oxygen-containing functional groups, which gave KOH-activated graphene excellent adsorption capacity (approx. 532.59 mg g -1 ) of TC. Further study on the adsorption mechanism showed that the Langmuir isotherm model and the pseudo-second-order kinetic model fitted with experiment data. To further understand the adsorption process, the effects of solid-liquid ratio, pH, ionic strength and coexisting ions were also investigated. The results revealed that, compared with pH and ionic strength, solid-liquid ratio and coexisting ions (Cu 2+ , CrO 4 2- ) had more significant influence over the adsorption performance. The findings provide guidance for application of KOH-activated graphene as a promising alternative adsorbent for antibiotics removal from aqueous solutions.

  4. Influence of Market Competition on Tetracycline Pricing and Impact of Price Increases on Clinician Prescribing Behavior.

    Science.gov (United States)

    Barbieri, John S; Margolis, David J; Brod, Bruce A

    2017-12-01

    Oral tetracyclines are commonly used for acne and other conditions. Recent generic price increases threaten access to these medications. Using the OptumInsight Clinformatics DataMart, we retrospectively evaluated the underlying factors behind these price increases for oral tetracylines using the framework of a competitive market and evaluated the impact of these price increases on prescribing practices. Between 2011 and 2013, the mean cost of doxycycline hyclate prescriptions increased from $7.16 to $139.89 and the mean out-of-pocket cost increased by $9.69. A comparable cost increase was not observed for doxycycline monohydrate or minocycline. There was no significant association between the cost of doxycycline hyclate and market concentration as assessed by the Herfindahl-Hirschman index (β = 0.030, 95% confidence interval -0.019 to 0.079, P = 0.213) and the market was highly concentrated throughout the study period. The percentage of prescriptions for doxycycline hyclate decreased by 1.9% from 2011 to 2013. This dramatic increase in the cost of doxycycline hyclate is not easily explained using the framework of a competitive market, suggesting that noncompetitive market forces may be responsible. In addition, clinicians have not altered their prescribing behavior in response to this price increase, suggesting that clinician or pharmacy level interventions could potentially increase the use of less costly substitutes. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Tetracycline alters gene expression in Salmonella strains that harbor the Tn10 transposon.

    Science.gov (United States)

    Hüttener, M; Prieto, A; Aznar, S; Dietrich, M; Paytubi, S; Juárez, A

    2018-04-01

    In this report, we show that bacterial plasmids that harbor the Tn10 transposon (i.e., the IncHI1 plasmid R27) modify expression of different Salmonella regulons responding to the presence of tetracycline (Tc) in the medium. By using as a model the Tc-dependent upregulation of the ibpAB operon (which belongs to the heat shock regulon), we have identified Tn10-tetA (coding for a Tc efflux pump) and adjacent tetC sequences as required for ibpAB upregulation. Characterization of transcripts in the tetAC region showed that tetA transcription can continue into tetC sequences, generating a long 3'UTR sequence, which can protect transcripts from RNA processing, thus increasing the expression of TetA protein. In the presence of Tc, the DnaK and IbpA chaperones are overexpressed and translocated to the periplasm and to the membrane fraction respectively. DnaK targeting unfolded proteins is known to induce heat shock by avoiding RpoH proteolysis. We correlate expression levels of Tn10-encoded TetA protein with heat shock induction in Salmonella, likely because TetA activity compromises protein secretion. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. An iPhone-based digital image colorimeter for detecting tetracycline in milk.

    Science.gov (United States)

    Masawat, Prinya; Harfield, Antony; Namwong, Anan

    2015-10-01

    An iPhone-based digital image colorimeter (DIC) was fabricated as a portable tool for monitoring tetracycline (TC) in bovine milk. An application named ColorConc was developed for the iPhone that utilizes an image matching algorithm to determine the TC concentration in a solution. The color values; red (R), green (G), blue (B), hue (H), saturation (S), brightness (V), and gray (Gr) were measured from each pictures of the TC standard solutions. TC solution extracted from milk samples using solid phase extraction (SPE) was captured and the concentration was predicted by comparing color values with those collected in a database. The amount of TC could be determined in the concentration range of 0.5-10 μg mL(-1). The proposed DIC-iPhone is able to provide a limit of detection (LOD) of 0.5 μg mL(-1) and limit of quantitation (LOQ) of 1.5 μg mL(-1). The enrichment factor was 70 and color of the extracted milk sample was a strong yellow solution after SPE. Therefore, the SPE-DIC-iPhone could be used for the assay of TC residues in milk at the concentration lower than LOD and LOQ of the proposed technique. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Selective degradation of tetracycline antibiotics present in raw milk by electrochemical method.

    Science.gov (United States)

    Kitazono, Yumika; Ihara, Ikko; Yoshida, Gen; Toyoda, Kiyohiko; Umetsu, Kazutaka

    2012-12-01

    The dairy industry disposes of a large volume of waste milk with antibiotic residues, which is a great cause of much concern in soil and water environments. In this study, the electrochemical oxidation of tetracycline antibiotics (TCs) in cow's milk was investigated. Milk contains a high concentration of organic matter, and the concentrations of TCs residues are extremely low. The effects of anode materials and electrolytes on the degradation of oxytetracycline (OTC) were investigated. A higher degradation rate for the OTC was attained using the inactive anode or a NaCl electrolyte. It was found that a physically adsorbed oxidant on the surface of the anode and indirect oxidation using electrogenerated hypochlorite could enhance the degradation of OTC in raw milk. The organic components in milk samples affected the removal rate of the OTC. The removal rate constants for the OTC in raw milk were 2.8-7.7 times higher than the chemical oxygen demand values. It was found that electrochemical oxidation could decompose low concentrations of TCs in high concentrations of organic matter solutions selectively. The results indicate that electrochemical oxidation is an effective method for the treatment of TCs in waste milk. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Generalized canine discoid lupus erythematosus responsive to tetracycline and niacinamide therapy.

    Science.gov (United States)

    Rossi, Michael A; Messenger, Linda M; Linder, Keith E; Olivry, Thierry

    2015-01-01

    Discoid lupus erythematosus (DLE) is a commonly reported canine autoimmune disease that normally presents with a phenotype consisting of erythema, depigmentation, scaling, erosions/ulcers, and scarring over the nasal planum and the proximal dorsal muzzle. Recently, two cases of a generalized variant of this disease have been reported, whose lesions responded to either systemic glucocorticoids or a combination of topical corticosteroids, topical tacrolimus, and the oral antimalarial hydroxychloroquine. The purpose of this report is to describe an 11 yr old shih tzu that presented with skin lesions consisting of multiple annular, erythematous papules and plaques, hyperpigmentation, adherent scaling, and atrophic scars over the caudal dorsum, flanks, craniodorsal thorax, and lateroproximal extremities. A diagnosis of generalized DLE was made based on the clinical presentation, histopathology, laboratory values, and direct immunofluorescence findings. Treatment consisted of oral tetracycline and oral niacinamide, which resulted in complete remission of clinical signs. This is the first documented report of generalized canine DLE responding to the described immunomodulating regimen. Such a combination might therefore be considered as a glucocorticoid and/or antimalarial alternative for the management of generalized DLE.

  9. Iron improving bio-char derived from microalgae on removal of tetracycline from aqueous system.

    Science.gov (United States)

    Peng, Liang; Ren, Yanqing; Gu, Jidong; Qin, Pufeng; Zeng, Qingru; Shao, Jihai; Lei, Ming; Chai, Liyuan

    2014-06-01

    Novel magnetic carbonaceous bio-char was hydrothermal prepared from microalgae under different loadings of iron and its structures and surface chemistry were characterized with Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and nitrogen adsorption-desorption isotherm (BET). The morphology of bio-char changed from sheet to particle as iron loading increased and its surface area also increased. When 3.0 g of dried microalgae and 6.0 mmol iron salt ((NH4)2SO4·FeSO4·6H2O) were mixed and treated, the obtained bio-char possessing the highest amount of oxygen-containing functional groups resulted in the best adsorption performance on tetracycline (TC). This adsorption process was fitted to Langmuir adsorption isotherm and the maximum adsorption capacity was 95.86 mg/g, which is higher than other bio-char reported. The iron loading contributed to the higher adsorption capacity of bio-char, which may be due to three factors, the high surface area, more hydrogen bonding, and bridging effects of the structural Fe for TC. Our data suggest that bio-char may have more important role in stabilization of pollutants in the environment.

  10. Soil microbial response to tetracycline in two different soils amended with cow manure.

    Science.gov (United States)

    Chessa, Luigi; Pusino, Alba; Garau, Giovanni; Mangia, Nicoletta Pasqualina; Pinna, Maria Vittoria

    2016-03-01

    High amounts of antibiotics are introduced in the soil environment by manure amendment, which is the most important spreading route in soil, with a potential ecotoxicological impact on the environment. The objectives of this study were (a) to assess the tetracycline (Tc) bioavailability in a clay and in a sandy soil, and (b) to evaluate the effects of the Tc and cow manure on the structure and function of soil microbial communities. Clay and sandy soils were spiked with Tc at the concentrations of 100 and 500 mg Tc kg(-1) soil, and were amended or not with cow manure. The clay soil showed greater Tc sorption capacity and bioavailable Tc was between 0.157 and 4.602 mg kg(-1) soil. Tc dose and time-dependent effects on soil microbial communities were investigated by fluorescein diacetate activity, phospholipid fatty acids analysis, as well as by Biolog community level physiological profile and microbial counts at 2, 7 and 60 days after Tc and/or manure addition. The added Tc caused detrimental effect on the microbial activity and structure, particularly in the short term at the highest concentrations. However, the Tc effect was transient' it decreased after 7 days and totally disappeared within 60 days. Cow manure shifted the bacterial structure in both soils, increased the microbial activity in clay soil and contributed to recover the microbial structure in Tc-spiked manure treatments.

  11. Tetracycline adsorption onto activated carbons produced by KOH activation of tyre pyrolysis char.

    Science.gov (United States)

    Acosta, R; Fierro, V; Martinez de Yuso, A; Nabarlatz, D; Celzard, A

    2016-04-01

    Tyre pyrolysis char (TPC), produced when manufacturing pyrolysis oil from waste tyre, was used as raw material to prepare activated carbons (ACs) by KOH activation. KOH to TPC weight ratios (W) between 0.5 and 6, and activation temperatures from 600 to 800 °C, were used. An increase in W resulted in a more efficient development of surface area, microporosity and mesoporosity. Thus, ACs derived from TPC (TPC-ACs) with specific surface areas up to 814 m(2) g(-1) were obtained. TPC, TPC-ACs and a commercial AC (CAC) were tested for removing Tetracycline (TC) in aqueous phase, and systematic adsorption studies, including equilibrium, kinetics and thermodynamic aspects, were performed. Kinetics was well described by the pseudo-first order model for TPC, and by a pseudo second-order kinetic model for ACs. TC adsorption equilibrium data were also fitted by different isotherm models: Langmuir, Freundlich, Sips, Dubinin-Radushkevich, Dubinin-Astokov, Temkin, Redlich-Peterson, Radke-Prausnitz and Toth. The thermodynamic study confirmed that TC adsorption onto TPC-ACs is a spontaneous process. TC adsorption data obtained in the present study were compared with those reported in the literature, and differences were explained in terms of textural properties and surface functionalities. TPC-ACs had similar performances to those of commercial ACs, and might significantly improve the economic balance of the production of pyrolysis oil from waste tyres. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Effect of Ampicillin, Streptomycin, Penicillin and Tetracycline on Metal Resistant and Non-Resistant Staphylococcus aureus

    Science.gov (United States)

    Chudobova, Dagmar; Dostalova, Simona; Blazkova, Iva; Michalek, Petr; Ruttkay-Nedecky, Branislav; Sklenar, Matej; Nejdl, Lukas; Kudr, Jiri; Gumulec, Jaromir; Tmejova, Katerina; Konecna, Marie; Vaculovicova, Marketa; Hynek, David; Masarik, Michal; Kynicky, Jindrich; Kizek, Rene; Adam, Vojtech

    2014-01-01

    There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead) to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM) on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control) of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health. PMID:24651395

  13. Containment: Relevant or Relic?

    Science.gov (United States)

    2011-06-10

    Cold Warmonger,‖ New York Times, 25 May 1997, http://query.nytimes.com/ gst /fullpage.html?res=9800EEDA1438F936A15756C0A96195 8260 (accessed 28...containing piracy rates and operating areas to current levels. Other countries, like India , appear to have taken the gloves off, and are aggressively...deployed in action against Somalia piracy. 4. China-Independent deployer. 5. Russia-Independent deployer. 6. India -Independent deployer. 7. Taiwan

  14. Adverse effect of tetracycline and doxycycline on testicular tissue and sperm parameters in CD1 outbred mice

    Czech Academy of Sciences Publication Activity Database

    Elzeinová, Fatima; Pěknicová, Jana; Děd, Lukáš; Kubátová, Alena; Margaryan, Hasmik; Dorosh, Andriy; Makovický, P.; Rajmon, R.

    2013-01-01

    Roč. 65, Sep (2013), s. 911-917 ISSN 0940-2993 R&D Projects: GA MŠk(CZ) 1M06011; GA ČR(CZ) GA523/09/1793; GA ČR(CZ) GAP503/12/1834 Institutional research plan: CEZ:AV0Z50520701 Keywords : Tetracycline * Doxycycline * Testes * Sperm * Apoptosis * Puberty Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.005, year: 2013

  15. Korrek, volledig, relevant

    DEFF Research Database (Denmark)

    Bergenholtz, Henning; Gouws, Rufus

    2007-01-01

    In explanatory dictionaries, both general language dictionaries and dictionaries dealing with languages for special purposes, the lexicographic definition is an important item to present the meaning of a given lemma. Due to a strong linguistic bias, resulting from an approach prevalent in the early...... phases of the development of theoretical lexicography, a distinction is often made between encyclopaedic information and semantic information in dictionary definitions, and dictionaries had often been criticized when their definitions were dominated by an encyclopaedic approach. This used to be seen...... as detrimental to the status of a dictionary as a container of linguistic knowledge. This paper shows that, from a lexicographic perspective, such a distinction is not relevant. What is important is that definitions should contain information that is relevant to and needed by the target users of that specific...

  16. Relevance and definition.

    Science.gov (United States)

    Watson, R

    1995-02-01

    The study examined whether the use of superordinate terms in children's definitions was predicted by relevance theory. Two hundred and six children aged five to ten years gave definitions for 16 basic-level words and four superordinate words from natural kind and artefact semantic domains. Superordinate terms were used more frequently when they supported more inferences. This was evidenced by their more frequent use in natural kind than in artefact domains, and more frequent use when the superordinate was itself defined by a semantically complex expression. When used, superordinates also usually occurred at the beginning of the definitional expression. It is argued that these findings reflect the speaker's intention to achieve optimal relevance, that is, to achieve maximum contextual effects with the least processing effort.

  17. Enhancing anaerobic digestion and methane production of tetracycline wastewater in EGSB reactor with GAC/NZVI mediator.

    Science.gov (United States)

    Zhang, Zhaohan; Gao, Peng; Cheng, Jiaqi; Liu, Guohong; Zhang, Xiaoqi; Feng, Yujie

    2018-06-01

    Packing nano mediators into anaerobic system is an attractive technology to strengthen refractory pollutant removal and methane production from wastewater, but is limited by the drawbacks such as easy loss and poor mass transfer. In this study, GAC/NZVI mediator was added into EGSB reactor to investigate the enhancement effects and mechanism for anaerobic digestion of tetracycline wastewater and its impacts on microbial community structure. The results indicated that GAC/NZVI could enhance COD and TOC removal by 12.1% and 10.3%, while have no evident influence on tetracycline removal and sulfide production. The biogas production and methane content were increased by 21.2% and 26.9%, respectively. GAC/NZVI addition resulted in formation of densely packed aggregates, and evidently increased the electrical conductivity and EPS content in sludge. Fe content in sludge was 20.43% with the loss of only 5.4% during 34 d operation. Microbial community analysis revealed that GAC/NZVI addition could both increase the Chao 1 richness index and Shannon diversity index of bacteria and archaea. It was notable that total methanogens contents increased from 74.7% to 81.74% at genera level, resulting in higher methane production, while Treponema increase might promote the degradation of tetracycline and its metabolite, leading to higher COD removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Simultaneous Determination of TetracyclinesResidues in Bovine Milk Samples by Solid Phase Extraction and HPLC-FL Method

    Directory of Open Access Journals (Sweden)

    Mehra Mesgari Abbasi

    2011-06-01

    Full Text Available Introduction:Tetracyclines (TCs are widely used in animal husbandry and their residues in milk may resultinharmful effects on human. The aim of this study was to investigate the presence of TCs residues in various bovine milk samples from local markets of Ardabil, Iran. Methods:One hundred and fourteen pasteurized, sterilized and raw milk samples were collected from markets of Ardabil. Tetracycline, Oxytetracycline and Chlortetracycline (TCs residues extraction carried out by Solid Phase Extraction method. Determination of TCs residues were performed by high performance liquid chromatography (HPLC method using Fluorescence detector.Results: The mean of total TCs residues in all samples (114 samples was 97.6 ±16.9ng/g and that of pasteurized, sterilized and raw milk samples were 87.1 ± 17.7, 112.0 ± 57.3 and 154.0 ± 66.3ng/g respectively. Twenty five point four percent of the all samples, and24.4%, 30% and 28.6% of the pasteurized, sterilized and raw milk samples, respectively had higher TCs residues than the recommended maximum levels (100ng/g. Conclusion:This study indicates the presence of tetracycline residues more than allowed amount. Regulatory authorities should ensure proper withdrawal period before milking the animals and definite supervisions are necessary on application of these drugs.

  19. A case of vesicular cutaneous lupus erythematosus in a Border collie successfully treated with topical tacrolimus and nicotinamide-tetracycline.

    Science.gov (United States)

    Lehner, Georg M; Linek, Monika

    2013-12-01

    Canine vesicular cutaneous lupus erythematosus (VCLE) is an autoimmune skin disease of the Shetland sheepdog and rough collie, which manifests as an erosive dermatitis of sparsely haired skin of the ventrum and concave pinnae. Reported treatment consists of immunosuppression with glucocorticoids alone or in combination with azathioprine, but successful treatment is unpredictable. To report on the treatment of VCLE in a Border collie dog with topical 0.1% tacrolimus and nicotinamide in combination with tetracycline. An 8-year-old male neutered Border collie was presented with multiple coalescing erosions on the ventral abdomen, groin and axillae and ulceration on the oral commissures. Clinical presentation, routine diagnostics, histology and immunohistochemistry were consistent with VCLE. Remission was achieved with topical 0.1% tacrolimus and combination therapy of nicotinamide and tetracycline. This dog responded well to treatment with topical 0.1% tacrolimus, nicotinamide-tetracycline and sun avoidance. Complete remission was achieved after 2.5 months, and the dog was lesion free during a 1 year follow-up period. © 2013 ESVD and ACVD.

  20. Liquid chromatography – tandem mass spectrometry method for the determination of ten tetracycline residues in muscle samples

    Directory of Open Access Journals (Sweden)

    Gajda Anna

    2015-09-01

    Full Text Available A liquid chromatography – tandem mass spectrometry (LC-MS/MS method for the determination of oxytetracycline (OTC, 4-epi oxytetracycline (4-epi OTC, tetracycline (TC, 4-epi tetracycline (4-epi TC, chlortetracycline (CTC, 4-epi chlortetracycline (4-epi CTC, doxycycline (DC, minocycline (MINO, methacycline (META and rolitetracycline (ROLI residues in muscles was developed. The procedure consisted of an oxalic acid extraction followed by protein removal with trichloroacetic acid. Further solid phase clean-up on polymeric (Strata X reversed phase columns was performed to obtain an extract suitable for LC-MS/MS analysis. The tetracyclines were separated on a C 18 analytical column with mobile phase consisting of 0.01% formic acid in acetonitrile and 0.01% formic acid in water in gradient mode. The method was validated according to the Commission Decision 2002/657/EC. The recoveries of all target compounds were 91.8% – 103.6%. The decision limits were from 109.0 to 119.8 μg/kg and detection capability varied within the range of 122.2 to 137.6 μg/kg, depending on the analyte.

  1. Spectrophotometric flow-injection analysis assay of tetracycline antibiotics using a dual light-emitting diode based detector

    Directory of Open Access Journals (Sweden)

    Prinya Masawat

    2008-02-01

    Full Text Available In this paper, a small dual light-emitting diode (LED-based detector for FIA process analyser has been designed. The detector’s optical parts comprise a flow-through cell, a dual-blue LED and a photodiode. Neither mirrors nor lenses are used. The optical path for the first LED detects the blank, while the other LED detects the sample. The detector’s electronic components including a signal amplifier and an A/D converter are integrated on one small board connected to a PC for measuring the results. The designed spectrophotometric detector was used for the determination of tetracycline antibiotics. Uranyl acetate was used as a reagent forming orange-red complexes with the drugs in N,N– dimethylformamide. The complexes show absorption maxima at 410, 416 and 408 nm for tetracycline hydrochloride (TCH, chlortetracycline hydrochloride (CTCH, and doxycycline hydrochloride (DCH, respectively. The detection limit was found to be 0.38, 0.75, 1.44 µg mL-1 and the linear range was obtained at 1.0-3.0, 3.0-5.0, and 3.0-10.0 µg mL-1 for TCH, CTCH and DCH, respectively. The proposed method has been successfully applied to the determination of tetracycline antibiotic residues in milk samples. Moreover, this method is an environmentally friendly approach and suitable for routine analysis.

  2. Identification and characterization of tetracycline resistance in Lactococcus lactis isolated from Polish raw milk and fermented artisanal products.

    Science.gov (United States)

    Zycka-Krzesinska, Joanna; Boguslawska, Joanna; Aleksandrzak-Piekarczyk, Tamara; Jopek, Jakub; Bardowski, Jacek K

    2015-10-15

    To assess the occurrence of antibiotic-resistant Lactic Acid Bacteria (LAB) in Polish raw milk and fermented artisanal products, a collection comprising 500 isolates from these products was screened. Among these isolates, six strains (IBB28, IBB160, IBB161, IBB224, IBB477 and IBB487) resistant to tetracycline were identified. The strains showing atypical tetracycline resistance were classified as Lactococcus lactis: three of them were identified as L. lactis subsp. cremoris (IBB224, IBB477 and IBB487) and the other three (IBB28, IBB160, IBB161) were identified as L. lactis subsp. lactis. The mechanism involving Ribosomal Protection Proteins (RPP) was identified as responsible for tetracycline resistance. Three of the tested strains (IBB28, IBB160 and IBB224) had genes encoding the TetS protein, whereas the remaining three (IBB161, IBB477 and IBB487) expressed TetM. The results also demonstrated that the genes encoding these proteins were located on genetic mobile elements. The tet(S) gene was found to be located on plasmids, whereas tet(M) was found within the Tn916 transposon. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Study on Detection and Classification of Tetracycline Residue in Duck Meat Using Synchronous Fluorescence Spectra and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Haibin Xiao

    2013-07-01

    Full Text Available To the rapid detection of whether the tetracycline residues are excess in duck meat, the optimum characteristic wavelength difference λ was determined by synchronous fluorescence analytical method. The recognition model of different residual levels of tetracycline was established by using support vector machine classification algorithm. Firstly, the optimum wavelength difference λ for duck meat samples was determined as 70nm, and synchronous fluorescence spectra of different samples under the condition of λ 70nm were collected. Secondly, original synchronous fluorescence spectra were preprocessed by using standard normal variables change (SNV. Finally, 18 wavelength variables were selected from 121 wavelength variables of pretreatment spectra by using competitive adaptive reweighted sampling (CARS. Then the radial basis function (RBF was selected as the kernel function of support vector classification (SVC, and the optimal kernel function factor C and g were determined as 2.83 and 1, respectively, which were obtained by using grid searching combined with 5-fold cross validation. The classification model of SNV-CARS-SVC was established, and the classification accuracy rate of the model was 95.7% for prediction sets samples. The results showed that the synchronous fluorescence analysis method could identify tetracycline different residual levels quickly and accurately, and a feasible method was provided for identifying the quality of duck meat.

  4. Determination of fluoroquinolones, sulfonamides, and tetracyclines multiresidues simultaneously in porcine tissue by MSPD and HPLC–DAD

    Directory of Open Access Journals (Sweden)

    Hu Yu

    2012-02-01

    Full Text Available An efficient method is provided to detect simultaneously some important veterinary drugs from different classes in highly complex animal tissue matrix. This method using matrix solid-phase dispersion (MSPD and high performance liquid chromatography (HPLC with diode array detection (DAD is developed to effectively determine two fluoroquinolones (enoxacin and lomefloxacin, two sulfonamides (sulfanilamide and sulfamethoxazole and one tetracycline (tetracycline simultaneously in porcine tissues. In the process, MSPD methodology was used to treat samples, washed by n-hexane to remove lipid, eluted the analytes with acetonitrile–dichloromethane (1:1, v/v. Solvent acetonitrile and solvent acetic acid (0.1% were combined in a gradient. HPLC–DAD analysis of the tissue samples was performed within 15 min at a flow rate of 1.0 mL/min. The results showed that a recovery at 0.1, 0.5 and 1.0 μg/g fortification levels ranged from 80.6% to 99.2% with satisfactory relative standard deviations (RSDs (below 6.1%, n=3 and the limits of quantitation (LOQ ranged from 7 μg/kg to 34 μg/kg in porcine tissues. Utilization of the method in successfully simultaneous analysis of porcine tissue incurred with veterinary drug multiresidues is described. Keywords: Matrix solid-phase dispersion, High performance liquid chromatography, Fluoroquinolones, Sulfonamides, Tetracyclines, Multiresidues

  5. Molecular mechanisms of quinolone, macrolide, and tetracycline resistance among Campylobacter isolates from initial stages of broiler production.

    Science.gov (United States)

    Pérez-Boto, D; Herrera-León, S; García-Peña, F J; Abad-Moreno, J C; Echeita, M A

    2014-01-01

    The aim of this study was to investigate the resistance mechanisms of quinolones, macrolides and tetracycline in campylobacter isolates from grandparent and parent broiler breeders in Spain. Twenty-six isolates were investigated for quinolone resistance, three isolates for macrolide resistance and 39 for tetracycline resistance. All of the quinolone-resistant isolates possessed the mutation Thr86Ile in the quinolone resistance-determining region of gyrA and one isolate possessed the mutation Pro104Ser. Only one Campylobacter coli population (defined by restriction fragment length polymorphism-polymerase chain reaction of flaA and pulsed field gel electrophoresis) was resistant to erythromycin, and the mutation A2075G (23S rDNA) was responsible for macrolide resistance. The tetO gene was found in all of the tetracycline-resistant isolates. Twenty-two out of the 39 isolates investigated by Southern blot possessed chromosomic location of tetO and 17 were located on plasmids. Most of the plasmids with tetO were of around 60 kb and conjugation was demonstrated in a selection of them. In conclusion, we showed that Thr86Ile is highly prevalent in quinolone-resistant isolates as well as mutation A2075G in macrolide-resistant isolates of poultry origin. More variability was found for tetO. The possibility of horizontal transmission of tetO among campylobacter isolates is also an issue of concern in public health.

  6. Solid-Phase Extraction and Large-Volume Sample Stacking-Capillary Electrophoresis for Determination of Tetracycline Residues in Milk

    Directory of Open Access Journals (Sweden)

    Gabriela Islas

    2018-01-01

    Full Text Available Solid-phase extraction in combination with large-volume sample stacking-capillary electrophoresis (SPE-LVSS-CE was applied to measure chlortetracycline, doxycycline, oxytetracycline, and tetracycline in milk samples. Under optimal conditions, the proposed method had a linear range of 29 to 200 µg·L−1, with limits of detection ranging from 18.6 to 23.8 µg·L−1 with inter- and intraday repeatabilities < 10% (as a relative standard deviation in all cases. The enrichment factors obtained were from 50.33 to 70.85 for all the TCs compared with a conventional capillary zone electrophoresis (CZE. This method is adequate to analyze tetracyclines below the most restrictive established maximum residue limits. The proposed method was employed in the analysis of 15 milk samples from different brands. Two of the tested samples were positive for the presence of oxytetracycline with concentrations of 95 and 126 µg·L−1. SPE-LVSS-CE is a robust, easy, and efficient strategy for online preconcentration of tetracycline residues in complex matrices.

  7. Information Needs/Relevance

    OpenAIRE

    Wildemuth, Barbara M.

    2009-01-01

    A user's interaction with a DL is often initiated as the result of the user experiencing an information need of some kind. Aspects of that experience and how it might affect the user's interactions with the DL are discussed in this module. In addition, users continuously make decisions about and evaluations of the materials retrieved from a DL, relative to their information needs. Relevance judgments, and their relationship to the user's information needs, are discussed in this module. Draft

  8. Classroom Action Research: Penelitian Tindakan Kelas

    OpenAIRE

    Juliandi, Azuar

    2014-01-01

    The main purpose of this article is to provide a basic knowledge of classroom action research, systematic proposal and classroom action reporting. The Knowledge is so important because a professional lecturer must be able to understand the problems themselves and their learning environment through classroom action research activities. Various issues in classroom action research, including: planning, process, use of methods, media, resources and learning evaluations and other relevant issues. ...

  9. Tetracycline hypersensitivity of an ezrA mutant links GalE and TseB (YpmB to cell division

    Directory of Open Access Journals (Sweden)

    Pamela eGamba

    2015-04-01

    Full Text Available Cell division in bacteria is initiated by the polymerization of FtsZ into a ring-like structure at midcell that functions as a scaffold for the other cell division proteins. In Bacillus subtilis, the conserved cell division protein EzrA is involved in modulation of Z-ring formation and coordination of septal peptidoglycan synthesis. Here, we show that an ezrA mutant is hypersensitive to tetracycline, even when the tetracycline efflux pump TetA is present. This effect is not related to the protein translation inhibiting activity of tetracycline. Overexpression of FtsL suppresses this phenotype, which appears to be related to the intrinsic low FtsL levels in an ezrA mutant background. A transposon screen indicated that the tetracycline effect can also be suppressed by overproduction of the cell division protein ZapA. In addition, tetracycline sensitivity could be suppressed by transposon insertions in galE and the unknown gene ypmB, which was renamed tseB (tetracycline sensitivity suppressor of ezrA. GalE is an epimerase using UDP-glucose and UDP-N-acetylglucosamine as substrate. Deletion of this protein bypasses the synthetic lethality of zapA ezrA and sepF ezrA double mutations, indicating that GalE influences cell division. The transmembrane protein TseB contains an extracytoplasmic peptidase domain, and a GFP fusion shows that the protein is enriched at cell division sites. A tseB deletion causes a shorter cell phenotype, indicating that TseB plays a role in cell division. Why a deletion of ezrA renders B. subtilis cells hypersensitive for tetracycline remains unclear. We speculate that this phenomenon is related to the tendency of tetracycline analogues to accumulate into the lipid bilayer, which may destabilize certain membrane proteins.

  10. Implementation of the Bacillus cereus microbiological plate used for the screening of tetracyclines in raw milk samples with STAR protocol - the problem with false-negative results solved.

    Science.gov (United States)

    Raspor Lainšček, P; Biasizzo, M; Henigman, U; Dolenc, J; Kirbiš, A

    2014-01-01

    In antibiotic residue analyses the first step of screening is just as important as the following steps. Screening methods need to be quick and inexpensive, but above all sensitive enough to detect the antibiotic residue at or below the maximum residue limit (MRL). In the case of a positive result, the next step is conducted and further methods are used for confirmation. MRLs stated in European Union Regulation 37/2010 for tetracyclines in raw milk are: 100 µg kg(-1) for tetracycline, 100 µg kg(-1) for oxytetracycline, 100 µg kg(-1) for chlortetracycline and no limit for doxycycline because it is prohibited for use in animals from which milk is produced for human consumption. The current five-plate microbiological screening method for the detection of antibiotic residues in raw milk was found to be simple and inexpensive, but not specific, sensitive and reliable enough to detect tetracycline at MRL in routine raw milk screening procedures. Spiking samples with tetracycline at the MRL level and applying them on Bacillus cereus ATCC 11778 microbiological plates often gave false-negative results, indicating that tetracyclines may have to be inactivated or masked. Tetracyclines seem to bind to a certain component in milk. Consequently, when applying samples to the B. cereus microbiological plate the antibiotic cannot inhibit the growth of B. cereus which disables the formation of inhibition zones on the test plate. After adding the appropriate amount of citric acid into the milk samples, we solved the problem of false-negative results. During the validation 79 samples of milk were spiked with tetracyclines at different concentrations: 100 µg kg(-1) for tetracycline, 100 µg kg(-1) for oxytetracycline, 80 µg kg(-1) for chlortetracycline and 30 µg kg(-1) for doxycycline. Concentrations used in the validation matched the requirements for MRLs (they were either at or below the MRLs) stated in European Union Regulation 37/2010. The sensitivity of the validation was 100%.

  11. Occurrence of tetracycline-resistant fecal coliforms and their resistance genes in an urban river impacted by municipal wastewater treatment plant discharges.

    Science.gov (United States)

    Zhang, Chong-Miao; Du, Cong; Xu, Huan; Miao, Yan-Hui; Cheng, Yan-Yan; Tang, Hao; Zhou, Jin-Hong; Wang, Xiao-Chang

    2015-01-01

    Antibiotic resistance of fecal coliforms in an urban river poses great threats to both human health and the environment. To investigate the occurrence and distribution of antibiotic resistant bacteria in an urban river, water samples were collected from the Chanhe River in Xi'an, China. After membrane filtration of water samples, the tetracycline resistance rate of fecal coliforms and their resistance genes were detected by plating and polymerase chain reaction (PCR), respectively. We found that fecal coliforms were generally resistant to tetracycline and saw average resistance rates of 44.7%. The genes tetA and tetB were widely detected, and their positive rate was 60%-100% and 40%-90%, respectively. We found few strains containing tetC, tetK, tetQ and tetX, and we did not identify any strains containing tetG, tetM or tetO. The prevalence of tetA and tetB over other genes indicated that the main mechanism for resistance to tetracycline is by changes to the efflux pump. Our analysis of the types and proportion of tetracycline resistance genes in the Chanhe River at locations upstream and downstream of the urban center suggests that the increased number of tetracycline-resistant fecal coliforms and spatial variation of tetracycline resistance genes diversity were related to municipal wastewater treatment plant discharge.

  12. Sustainability and Entrepreneurial Action

    DEFF Research Database (Denmark)

    Korsgaard, Steffen T.; Anderson, Alistair

    instrument in the pursuit of sustainability.  Prior Work - Extant literature identifies two main approaches to sustainable entrepreneurship. (i) traditional exploitation of environmentally relevant opportunities and (ii) institutional entrepreneurship creating opportunities. We identify a novel form......: resource oriented sustainable entrepreneurial action.  Approach - The paper uses a case study approach to build deeper theoretical knowledge of environmentally sustainable entrepreneurship.  Results - The paper identifies and analyses a distinct form of sustainable entrepreneurship -  resource oriented...... entrepreneurship - which uses bricolage in various ways to create sustainable solutions. Implications and value - The concept of resource oriented sustainable entrepreneurship contributes to the theoretical understanding of how entrepreneurial action can support sustainability, Furthermore the case study has...

  13. The evolution of relevance.

    Science.gov (United States)

    Scott-Phillips, Thomas C

    2010-05-01

    With human language, the same utterance can have different meanings in different contexts. Nevertheless, listeners almost invariably converge upon the correct intended meaning. The classic Gricean explanation of how this is achieved posits the existence of four maxims of conversation, which speakers are assumed to follow. Armed with this knowledge, listeners are able to interpret utterances in a contextually sensible way. This account enjoys wide acceptance, but it has not gone unchallenged. Specifically, Relevance Theory offers an explicitly cognitive account of utterance interpretation that presents a radical challenge to the neo-Gricean paradigm. Evolutionary considerations are one way in which we can choose between competing theories. A simple game-theoretic model of the evolution of communication is presented, and it is used to derive a number of basic qualities that will be satisfied by all evolved communication systems. These qualities are observed to precisely predict the foundational principles of Relevance Theory. The model thus provides biological support for that enterprise in general, and for the plausibility of the cognitive mechanisms that it describes in particular. Copyright © 2010 Cognitive Science Society, Inc.

  14. [Relevant public health enteropathogens].

    Science.gov (United States)

    Riveros, Maribel; Ochoa, Theresa J

    2015-01-01

    Diarrhea remains the third leading cause of death in children under five years, despite recent advances in the management and prevention of this disease. It is caused by multiple pathogens, however, the prevalence of each varies by age group, geographical area and the scenario where cases (community vs hospital) are recorded. The most relevant pathogens in public health are those associated with the highest burden of disease, severity, complications and mortality. In our country, norovirus, Campylobacter and diarrheagenic E. coli are the most prevalent pathogens at the community level in children. In this paper we review the local epidemiology and potential areas of development in five selected pathogens: rotavirus, norovirus, Shiga toxin-producing E. coli (STEC), Shigella and Salmonella. Of these, rotavirus is the most important in the pediatric population and the main agent responsible for child mortality from diarrhea. The introduction of rotavirus vaccination in Peru will have a significant impact on disease burden and mortality from diarrhea. However, surveillance studies are needed to determine the impact of vaccination and changes in the epidemiology of diarrhea in Peru following the introduction of new vaccines, as well as antibiotic resistance surveillance of clinical relevant bacteria.

  15. Tetracycline-inducible system for regulation of skeletal muscle-specific gene expression in transgenic mice

    Science.gov (United States)

    Grill, Mischala A.; Bales, Mark A.; Fought, Amber N.; Rosburg, Kristopher C.; Munger, Stephanie J.; Antin, Parker B.

    2003-01-01

    Tightly regulated control of over-expression is often necessary to study one aspect or time point of gene function and, in transgenesis, may help to avoid lethal effects and complications caused by ubiquitous over-expression. We have utilized the benefits of an optimized tet-on system and a modified muscle creatine kinase (MCK) promoter to generate a skeletal muscle-specific, doxycycline (Dox) controlled over-expression system in transgenic mice. A DNA construct was generated in which the codon optimized reverse tetracycline transactivator (rtTA) was placed under control of a skeletal muscle-specific version of the mouse MCK promoter. Transgenic mice containing this construct expressed rtTA almost exclusively in skeletal muscles. These mice were crossed to a second transgenic line containing a bi-directional promoter centered on a tet responder element driving both a luciferase reporter gene and a tagged gene of interest; in this case the calpain inhibitor calpastatin. Compound hemizygous mice showed high level, Dox dependent muscle-specific luciferase activity often exceeding 10,000-fold over non-muscle tissues of the same mouse. Western and immunocytochemical analysis demonstrated similar Dox dependent muscle-specific induction of the tagged calpastatin protein. These findings demonstrate the effectiveness and flexibility of the tet-on system to provide a tightly regulated over-expression system in adult skeletal muscle. The MCKrtTA transgenic lines can be combined with other transgenic responder lines for skeletal muscle-specific over-expression of any target gene of interest.

  16. Study of the radiolysis of tetracycline hidrochloride in aerated aqueous solutions

    International Nuclear Information System (INIS)

    Guedes, S.M.L.; Vasconcellos, M.B.A.

    1983-01-01

    The radiolysis of tetracycline hydrochloride (TC) was studied in neutral, acid and alkaline aerated solutions, by electron spin resonance spectroscopy at 77K. The paramagnetic species observed are: H.; OH.; HO 2 .; e - trapped and impurity radical. The reaction mechanism shows that the solute reacts with the solvent before the radiolysis and produces H + ions, as a consequence of the ionization of tricarbonylmethane group. The H + ions react with the e - from the radiolysis of water and produce HO 2 in the presence of O 2 . The interaction of TC with the alkaline solvent favours the interaction between gamma rays and solute. The products formed in the interaction of solute with the solvent before the radiolysis, as a consenquence of the ionization of TC, according to the pH of the solution, are of fundamental importance in the interaction of gamma rays with the solute. A crude estimate of the average distance that the e - is able to travel through solvent molecules before its capture by the solute was obtained in these 0.1N, 0.5N and 1.0N NaOH aqueous solutions. Until [TC] - travels more in solutions that contain less [NaOH]. In higher [TC] the e - travels through 680 solvent molecules. In order to explain the selective capture of the e3- by solute molecules, a simple model is suggested based on the existence of channel walls of solvent molecules where the electrical atraction betwwed Na + and e - influences the collision frequency and the energy loss. (Author) [pt

  17. Electrospinning of PLGA/gum tragacanth nanofibers containing tetracycline hydrochloride for periodontal regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Ranjbar-Mohammadi, Marziyeh [Textile Engineering Group, Department of Engineering, University of Bonab, Bonab (Iran, Islamic Republic of); Zamani, M. [Mechanical Engineering Department, National University of Singapore (Singapore); Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore (Singapore); Prabhakaran, M.P., E-mail: nnimpp@nus.edu.sg [Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore (Singapore); Bahrami, S. Hajir, E-mail: hajirb@aut.ac.ir [Textile Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ramakrishna, S. [Mechanical Engineering Department, National University of Singapore (Singapore); Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore (Singapore)

    2016-01-01

    Controlled drug release is a process in which a predetermined amount of drug is released for longer period of time, ranging from days to months, in a controlled manner. In this study, novel drug delivery devices were fabricated via blend electrospinning and coaxial electrospinning using poly lactic glycolic acid (PLGA), gum tragacanth (GT) and tetracycline hydrochloride (TCH) as a hydrophilic model drug in different compositions and their performance as a drug carrier scaffold was evaluated. Scanning electron microscopy (SEM) results showed that fabricated PLGA, blend PLGA/GT and core shell PLGA/GT nanofibers had a smooth and bead-less morphology with the diameter ranging from 180 to 460 nm. Drug release studies showed that both the fraction of GT within blend nanofibers and the core–shell structure can effectively control TCH release rate from the nanofibrous membranes. By incorporation of TCH into core–shell nanofibers, drug release was sustained for 75 days with only 19% of burst release within the first 2 h. The prolonged drug release, together with proven biocompatibility, antibacterial and mechanical properties of drug loaded core shell nanofibers make them a promising candidate to be used as drug delivery system for periodontal diseases. - Highlights: • Novel drug loaded blend (PG-TCH) and core shell nanofibers (PG(cs)-TCH) from PLGA and gum tragacanth (GT) fabricated • Prolonged release of TCH with lower burst release and high mechanical strength in wet and dry conditions for nanofibers • Proven cytocompatibility properties and low rigidity/stiffness suggest PG(cs)-TCH nanfiber for periodontal regeneration.

  18. Synthesis of Fe3O4/Polyacrylonitrile Composite Electrospun Nanofiber Mat for Effective Adsorption of Tetracycline.

    Science.gov (United States)

    Liu, Qing; Zhong, Lu-Bin; Zhao, Quan-Bao; Frear, Craig; Zheng, Yu-Ming

    2015-07-15

    Novel Fe3O4/polyacrylonitrile (PAN) composite nanofibers (NFs) were prepared by a simple two-step process, an electrospinning and solvothermal method. Characterization by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) demonstrated formation of a uniform nanoparticles coating (about 20 nm in thickness) on the PAN nanofiber backbone. The coating was constructed by well-crystallized cubic phase Fe3O4 nanoparticles as examined by X-ray diffraction spectroscopy (XRD). The coating doubled the specific surface area of NFs, from 8.4 to 17.8 m2 g(-1), as confirmed by nitrogen sorption isotherm analysis. To evaluate the feasibility of Fe3O4/PAN composite NFs as a potential adsorbent for antibiotic removal, batch adsorption experiments were conducted using tetracycline (TC) as the model antibiotic molecule. The results showed that Fe3O4/PAN composite NFs were effective in removing TC with no impactful loss of Fe in the pH regime of environmental interest (5-8). The adsorption of TC onto Fe3O4/PAN composite NFs better fitted the pseudo-second-order kinetics model, and the maximum adsorption capacity calculated from Langmuir isotherm model was 257.07 mg g(-1) at pH 6. The composite NFs also exhibited good regenerability over repeated adsorption/desorption cycles. Surface complexation between TC and the composite NFs contributed most to the adsorption as elucidated by X-ray photoelectron spectroscopy (XPS). This highly effective and novel adsorbent can be easily modularized and separated, promising its huge potential in drinking and wastewater treatment for antibiotic removal.

  19. Adsorption of tetracycline on kaolinite with pH-dependent surface charges.

    Science.gov (United States)

    Li, Zhaohui; Schulz, Laura; Ackley, Caren; Fenske, Nancy

    2010-11-01

    Kaolinite is a major type of clay minerals in soils of warm and humid climate. Although it has a much lower cation exchange capacity (CEC) and specific surface area compared to swelling clays, its ubiquitous existence as well as its pH-dependent surface charge makes it an important component to study the interactions between contaminants and soils. Tetracycline (TC) is a group of broad spectrum antibiotics used extensively in human and veterinary medicine. It has a high aqueous solubility and a long environmental half-life. In this study, the interactions between TC and kaolinite in aqueous solution were investigated in batch tests and supplemented by FTIR analyses. The adsorption of TC on kaolinite was mainly on the external surfaces via cation exchange as confirmed by stoichiometric desorption of exchangeable cations and simultaneous adsorption of H(+) rather than due to complexation. Under acidic conditions, a reduction in surface charge, thus the CEC, resulted in more desorption of exchangeable cations compared to TC adsorption. Fitting of the experimental data to the adsorption of different species revealed that TC(+) accounted for 4/5 of the total TC adsorbed with the remaining by zwitterion TC(0), possible via hydrogen bonding. At higher temperature, the pKa2 and pKa3 values seem to shift a pH unit lower. Due to its pH-dependent charge of kaolinite, TC adsorption is more pH dependent. The TC adsorption capacity on kaolinite was much lower compared to that on swelling clays. However, the adsorption rate constant was faster than that on swelling clays owing to surface adsorption instead of intercalation. Despite its low TC adsorption capacity, the ubiquitous existence of kaolinite in soils of warm climate may play a vital role in the fate and transport of TC in these soils. Copyright 2010 Elsevier Inc. All rights reserved.

  20. Insights into tetracycline adsorption onto kaolinite and montmorillonite: experiments and modeling.

    Science.gov (United States)

    Zhao, Yanping; Gu, Xueyuan; Li, Shiyin; Han, Ruiming; Wang, Guoxiang

    2015-11-01

    Adsorption of tetracycline (TC) on kaolinite and montmorillonite was investigated using batch adsorption experiments with different pH, ionic strength, and surface coverage. As a result, pH and ionic strength-dependent adsorption of TC was observed for the two clay minerals. The adsorption of TC decreased with the increase of pH and ionic strength, and high initial TC concentration had high adsorption. In addition, a triple-layer model was used to predict the adsorption and surface speciation of TC on the two minerals. As a result, four complex species on kaolinite (≡X(-)∙H3TC(+), ≡X(-)∙H2TC(±), ≡SOH(0)∙H2TC(±), and ≡SOH(0)∙HTC(-)) and three species on montmorillonite (≡X(-)∙H3TC(+), ≡X(-)∙H2TC(±), and ≡SOH(0)∙HTC(-)) were structurally constrained by spectroscopy, and these species were also successfully fitted to the adsorption edges of TC. Three functional groups of TC were involved in these adsorption reactions, including the positively charged dimethylamino group, the C=O amide I group, and the C=O group at the C ring. Combining adsorption experiments and model in this study, the adsorption of TC on kaolinite and montmorillonite was mainly attributed to cation exchange on the surface sites (≡X(-)) compared to surface complexation on the edge sites (≡SOH) at natural soil pH condition. Moreover, the surface adsorption species, the corresponding adsorption modes, and the binding constants for the surface reactions were also estimated.

  1. Campylobacter jejuni strains coresistant to tetracycline and ciprofloxacin in patients with gastroenteritis in Croatia.

    Science.gov (United States)

    Carev, Merica; Kovačić, Ana; Novak, Anita; Tonkić, Marija; Jerončić, Ana

    2017-04-01

    Antibiotic-resistant Campylobacter jejuni strains are rapidly emerging worldwide. Here, we aimed to determine the antibiotic-resistance patterns and genetic structure of C. jejuni from stool samples of symptomatic patients in Dalmatia, the largest Croatian county. In a population-based laboratory surveillance programme for campylobacteriosis in Dalmatia from May 2012 to May 2013, C. jejuni (n = 76) were collected from stool samples of all the patients hospitalized with gastroenteritis and matched positive outpatients (n = 77). Antibiotic susceptibility testing and pulsed-field gel electrophoresis (PFGE) genotyping of isolates were performed. Approximately 60% of the isolates were resistant to ciprofloxacin, whereas 24% of isolates were resistant to tetracycline; of the latter, 89% were also coresistant to ciprofloxacin. Resistance to erythromycin and gentamicin was infrequent (≤ 0.7%). Antibiotic-resistant strains were generally not associated with the need for hospitalization. However, the prevalence of coresistant strains increased sharply after 2010, and these coresistant strains were more prevalent in infections caused by clonal PFGE types, with distinct patterns of temporal occurrence and age distribution in infected patients. A high prevalence of coresistant Tc R /Cip R C. jejuni strains were detected in patients in Croatia. Strains were significantly associated with several clonal-type PFGE genotypes, shared common patterns of temporal occurrence, and showed distinct age distribution in infected patients, suggestive of newly identified strains. Since a high prevalence of coresistant Tc R /Cip R strains was also observed in other countries, further in-depth studies are essential to evaluate whether this phenomenon is linked to C. jejuni epidemiology in food animals and agricultural ecosystems.

  2. A localized outbreak of cholera due to vibrio cholerae, ogawa resistant to tetracyclines

    International Nuclear Information System (INIS)

    Ahmed, S.

    2015-01-01

    To study the clinical and laboratory parameters of a localized Cholera outbreak and determine the sensitivity pattern of the subtype involved. Study Design: A descriptive study. Place and Duration of Study: Combined Military Hospital, Lahore. Duration of Study: Two weeks. Patients and Methods: The study is about a localized outbreak of cholera in a group of soldiers, who consumed water from a single contaminated source of water. We are presenting here an account of the clinical and laboratory parameters of 39 hospitalized cases of cholera, who presented with profuse watery diarrhoea and vomiting. There vital signs, hydration status and systemic examination findings were recorded. Stool samples were sent for routine and microscopic examination and bacteriological culture. Blood samples were taken for complete blood count, serum sodium, potassium, urea and creatinine examination. SPSS 18 was used for statistical analysis of the results. Results: The average age of thirty nine men studied in this outbreak was 24.9 ± 6.9 years. There was no statistically significant difference between confirmed and suspected cholera cases on descriptive analysis of the clinical and laboratory parameters. Majority of patients showed pre-renal azotemia which improved within 48 to 72 hours of hospitalization. Stool cultures isolated Vibrio cholerae, subtype Ogawa, which was resistant to tetracyclines, cotrimoxazole and nalidixic acid but sensitive to fluoroquinolones and third generation cephalosporins. The outbreak was controlled when the contaminated water source was sealed and rectified. Conclusion: Multiple drug resistance strains of Vibrio cholera are causing large outbreaks which should be controlled by prevention of the disease and avoiding inappropriate use of antibiotics. (author)

  3. Chemosensitization of Trypanosoma congolense strains resistant to isometamidium chloride by tetracyclines and enrofloxacin.

    Directory of Open Access Journals (Sweden)

    Vincent Delespaux

    Full Text Available BACKGROUND: Because of the development of resistance in trypanosomes to trypanocidal drugs, the livelihood of millions of livestock keepers in sub-Saharan Africa is threatened now more than ever. The existing compounds have become virtually useless and pharmaceutical companies are not keen on investing in the development of new trypanocides. We may have found a breakthrough in the treatment of resistant trypanosomal infections, through the combination of the trypanocide isometamidium chloride (ISM with two affordable veterinary antibiotics. METHODOLOGY/PRINCIPAL FINDINGS: In a first experiment, groups of mice were inoculated with Trypanosoma congolense strains resistant to ISM and either left untreated or treated with (i tetracycline, (ii ISM or (iii the combination of the antibiotic and the trypanocide. Survival analysis showed that there was a significant effect of treatment and resistance to treatment on the survival time. The groups treated with ISM (with or without antibiotic survived significantly longer than the groups that were not treated with ISM (P<0.01. The group treated with the combination trypanocide/antibiotic survived significantly longer than the group treated with ISM (P<0.01. In a second experiment, groups of cattle were inoculated with the same resistant trypanosome strain and treated with (i ISM, (ii ISM associated with oxytetracycline or (iii ISM associated with enrofloxacine. All animals treated with ISM became parasitaemic. In the groups treated with ISM-oxytetracycline and ISM-enrofloxacine, 50% of the animals were cured. Animals from the groups treated with a combination trypanocide/antibiotic presented a significantly longer prepatent period than animals treated with ISM (p<0.001. The impact of the disease on the haematocrit was low in all ISM treated groups. Yet, it was lower in the groups treated with the combination trypanocide/antibiotic (p<0.01. CONCLUSIONS/SIGNIFICANCE: After optimization of the administration

  4. Fluoroquinolones and Tetracycline Antibiotics in a Portuguese Aquaculture System and Aquatic Surroundings: Occurrence and Environmental Impact.

    Science.gov (United States)

    Pereira, André M P T; Silva, Liliana J G; Meisel, Leonor M; Pena, Angelina

    2015-01-01

    The growth of aquaculture over the past few years is widely recognized as one of the main sources of antibiotics, mainly fluoroquinolones (FQ) and tetracyclines (TC), in the aquatic environment, consequently, increasing the risk of the emergence of antibiotic bacterial resistance and promoting the spread of resistant genes. This study aimed to (1) develop and validate a multiresidue method for determination and quantification of ciprofloxacin (CIP), difloxacin (DIFL), enrofloxacin (ENR), norfloxacin (NOR), sarafloxacin (SARA), and oxytetracycline (OXY) in aquaculture waters and surrounding water bodies and (2) provide the first Portuguese data to utilize in assessment of risk of adverse effects. In addition, the potential environmental impact posed by these antibiotics to aquatic organisms, belonging to different trophic levels, when exposed to the studied aquaculture waters was also assessed. The analytical strategy comprised of solid-phase extraction (SPE) through Oasis HLB cartridges, and detection and quantification by liquid chromatography with tandem mass spectrometry (LC/MS(n)). Method detection limits (MDL) and method quantification limits (MQL) were in the range of 0.7-3 ng/L and 2.4-10 ng/L, respectively. Recoveries varied between 57.4 and 122.8%. The method was applied to 31 water samples collected from an aquaculture and surrounding water bodies located in north of Portugal. Residues of all antibiotics, except SARA and DIFL, were detected at concentrations ranging from 3 to 75.1 ng/L. Norfloxacin was the antibiotic present at highest frequency and concentration. Regarding the environmental impact assessment (EIA), a risk quotient higher than 1 was observed for NOR.

  5. The Myth of Affirmative Action.

    Science.gov (United States)

    Roye, W.J.

    The principles of Affirmative Action policies and their implementation in American businesses and universities are examined in this paper. Issues such as discriminatory hiring practices, promotions and salaries, as well as the awarding of athletic scholarships, are discussed. Examples of relevant court cases are presented. Court decisions are…

  6. Efficient computation of optimal actions.

    Science.gov (United States)

    Todorov, Emanuel

    2009-07-14

    Optimal choice of actions is a fundamental problem relevant to fields as diverse as neuroscience, psychology, economics, computer science, and control engineering. Despite this broad relevance the abstract setting is similar: we have an agent choosing actions over time, an uncertain dynamical system whose state is affected by those actions, and a performance criterion that the agent seeks to optimize. Solving problems of this kind remains hard, in part, because of overly generic formulations. Here, we propose a more structured formulation that greatly simplifies the construction of optimal control laws in both discrete and continuous domains. An exhaustive search over actions is avoided and the problem becomes linear. This yields algorithms that outperform Dynamic Programming and Reinforcement Learning, and thereby solve traditional problems more efficiently. Our framework also enables computations that were not possible before: composing optimal control laws by mixing primitives, applying deterministic methods to stochastic systems, quantifying the benefits of error tolerance, and inferring goals from behavioral data via convex optimization. Development of a general class of easily solvable problems tends to accelerate progress--as linear systems theory has done, for example. Our framework may have similar impact in fields where optimal choice of actions is relevant.

  7. Minocycline and doxycycline, but not other tetracycline-derived compounds, protect liver cells from chemical hypoxia and ischemia/reperfusion injury by inhibition of the mitochondrial calcium uniporter

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Justin; Holmuhamedov, Ekhson; Zhang, Xun; Lovelace, Gregory L.; Smith, Charles D. [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC (United States); Lemasters, John J., E-mail: JJLemasters@musc.edu [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC (United States); Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC (United States)

    2013-11-15

    Minocycline, a tetracycline-derived compound, mitigates damage caused by ischemia/reperfusion (I/R) injury. Here, 19 tetracycline-derived compounds were screened in comparison to minocycline for their ability to protect hepatocytes against damage from chemical hypoxia and I/R injury. Cultured rat hepatocytes were incubated with 50 μM of each tetracycline-derived compound 20 min prior to exposure to 500 μM iodoacetic acid plus 1 mM KCN (chemical hypoxia). In other experiments, hepatocytes were incubated in anoxic Krebs–Ringer–HEPES buffer at pH 6.2 for 4 h prior to reoxygenation at pH 7.4 (simulated I/R). Tetracycline-derived compounds were added 20 min prior to reperfusion. Ca{sup 2+} uptake was measured in isolated rat liver mitochondria incubated with Fluo-5N. Cell killing after 120 min of chemical hypoxia measured by propidium iodide (PI) fluorometry was 87%, which decreased to 28% and 42% with minocycline and doxycycline, respectively. After I/R, cell killing at 120 min decreased from 79% with vehicle to 43% and 49% with minocycline and doxycycline. No other tested compound decreased killing. Minocycline and doxycycline also inhibited mitochondrial Ca{sup 2+} uptake and suppressed the Ca{sup 2+}-induced mitochondrial permeability transition (MPT), the penultimate cause of cell death in reperfusion injury. Ru360, a specific inhibitor of the mitochondrial calcium uniporter (MCU), also decreased cell killing after hypoxia and I/R and blocked mitochondrial Ca{sup 2+} uptake and the MPT. Other proposed mechanisms, including mitochondrial depolarization and matrix metalloprotease inhibition, could not account for cytoprotection. Taken together, these results indicate that minocycline and doxycycline are cytoprotective by way of inhibition of MCU. - Highlights: • Minocycline and doxycycline are the only cytoprotective tetracyclines of those tested • Cytoprotective tetracyclines inhibit the MPT and mitochondrial calcium and iron uptake. • Cytoprotective

  8. Complexação da tetraciclina, da oxitetraciclina e da clortetraciclina com o catião cobre (II. Estudo potenciométrico Tetracycline, oxytetracycline and chlortetracycline complexation with copper (II. Potentiometric study

    Directory of Open Access Journals (Sweden)

    Cristina M. C. M. Couto

    2000-08-01

    Full Text Available Stability constants of complexes formed by copper (II with three different tetracyclines (tetracycline, oxytetracycline and chlortetracycline have been determined potentiometrically with an automatic system in aqueous medium at 25,0 ± 0,2 ºC and I = 0,1 mol L-1 NaNO3. The protonation constants of the three tetracyclines were also determined under the same conditions. The distribution of the complexes was then simulated at therapeutic levels of the drugs.

  9. Removal of a mixture tetracycline-tylosin from water based on anodic oxidation on a glassy carbon electrode coupled to activated sludge.

    Science.gov (United States)

    Yahiaoui, Idris; Aissani-Benissad, Farida; Fourcade, Florence; Amrane, Abdeltif

    2015-01-01

    The purpose of this study was first to examine the electrochemical oxidation of two antibiotics, tetracycline (TC) and tylosin (Tylo), considered separately or in mixture, on a glassy carbon electrode in aqueous solutions; and then to assess the relevance of such electrochemical process as a pre-treatment prior to a biological treatment (activated sludge) for the removal of these antibiotics. The influence of the working potential and the initial concentration of TC and Tylo on the electrochemical pre-treatment process was also investigated. It was noticed that antibiotics degradation was favoured at high potential (2.4 V/ saturated calomel electrode (SCE)), achieving total degradation after 50 min for TC and 40 min for Tylo for 50 mg L(-1) initial concentration, with a higher mineralization efficiency in the case of TC. The biological oxygen demand in 5 days (BOD5)/Chemical oxygen demand (COD) ratio increased substantially, from 0.033 to 0.39 and from 0.038 to 0.50 for TC and Tylo, respectively. Regarding the mixture (TC and Tylo), the mineralization yield increased from 10.6% to 30.0% within 60 min of reaction time when the potential increased from 1.5 to 2.4 V/SCE and the BOD5/COD ratio increased substantially from 0.010 initially to 0.29 after 6 h of electrochemical pre-treatment. A biological treatment was, therefore, performed aerobically during 30 days, leading to an overall decrease of 72% of the dissolved organic carbon by means of the combined process.

  10. Electrophoretic deposition of CdS coatings and their photocatalytic activities in the degradation of tetracycline antibiotic

    Energy Technology Data Exchange (ETDEWEB)

    Vázquez, A., E-mail: alejandro.lqi@gmail.com [Universidad Autónoma de Nuevo León, Facultad de Ciencias Químicas, Av. Universidad S/N, San Nicolás de los Garza, 66455 Nuevo León (Mexico); Hernández-Uresti, D.B., E-mail: ing.dianahdz@gmail.com [Universidad Autónoma de Nuevo León, CICFIM–Facultad de Ciencias Físico Matemáticas, Av. Universidad S/N, San Nicolás de los Garza, 66455 Nuevo León (Mexico); Obregón, S. [Universidad Autónoma de Nuevo León, CICFIM–Facultad de Ciencias Físico Matemáticas, Av. Universidad S/N, San Nicolás de los Garza, 66455 Nuevo León (Mexico)

    2016-11-15

    Highlights: • CdS photocatalyst was prepared by electrophoretic deposition. • The CdS coating was used in the photodegradation of antibiotics. • O{sub 2}{sup −} and ·OH radicals were responsible for the degradation of tetracycline. - Abstract: The photocatalytic activities of CdS coatings formed by electrophoretic deposition (EPD) were evaluated through the photodegradation of an antibiotic, tetracycline. First, CdS nanoparticles were synthesized under microwave irradiation of aqueous solutions containing the cadmium and sulfur precursors at stoichiometric amounts and by using trisodium citrate as stabilizer. Microwave irradiation was carried out in a conventional microwave oven at 2.45 GHz and 1650 W of nominal power, for 60 s. The CdS nanoparticles were characterized by UV–vis spectrophotometry, photoluminescence and X-ray diffraction. Electrophoretic deposition parameters were 300 mV, 600 mV and 900 mV of applied voltage between aluminum plates separated by 1 cm. The fractal dimensions of the surfaces were evaluated by atomic force microscopy and correlated to the morphological and topographic characteristics of the coatings. The photocatalytic activity of the CdS coatings was investigated by means the photodegradation of the tetracycline antibiotic under simulated sunlight irradiation. According to the results, the photoactivity of the coatings directly depends on the concentration of the precursors and the applied voltage during the deposition. The material obtained at 600 mV showed the best photocatalytic behavior, probably due to its physical properties, such as optimum load and suitable aggregate size.

  11. Electrophoretic deposition of CdS coatings and their photocatalytic activities in the degradation of tetracycline antibiotic

    International Nuclear Information System (INIS)

    Vázquez, A.; Hernández-Uresti, D.B.; Obregón, S.

    2016-01-01

    Highlights: • CdS photocatalyst was prepared by electrophoretic deposition. • The CdS coating was used in the photodegradation of antibiotics. • O 2 − and ·OH radicals were responsible for the degradation of tetracycline. - Abstract: The photocatalytic activities of CdS coatings formed by electrophoretic deposition (EPD) were evaluated through the photodegradation of an antibiotic, tetracycline. First, CdS nanoparticles were synthesized under microwave irradiation of aqueous solutions containing the cadmium and sulfur precursors at stoichiometric amounts and by using trisodium citrate as stabilizer. Microwave irradiation was carried out in a conventional microwave oven at 2.45 GHz and 1650 W of nominal power, for 60 s. The CdS nanoparticles were characterized by UV–vis spectrophotometry, photoluminescence and X-ray diffraction. Electrophoretic deposition parameters were 300 mV, 600 mV and 900 mV of applied voltage between aluminum plates separated by 1 cm. The fractal dimensions of the surfaces were evaluated by atomic force microscopy and correlated to the morphological and topographic characteristics of the coatings. The photocatalytic activity of the CdS coatings was investigated by means the photodegradation of the tetracycline antibiotic under simulated sunlight irradiation. According to the results, the photoactivity of the coatings directly depends on the concentration of the precursors and the applied voltage during the deposition. The material obtained at 600 mV showed the best photocatalytic behavior, probably due to its physical properties, such as optimum load and suitable aggregate size.

  12. Keeping climate research relevant

    International Nuclear Information System (INIS)

    Rubin, E.S.; Lave, L.B.; Morgan, M.G.

    1992-01-01

    Recent post-mortems of the National Acid Precipitation Assessment Program (NAPAP) confirmed what Congress and other key parties to the acid rain debate already knew: that the 10-year, half-billion-dollar interagency program to guide US policy on acid rain control proved largely irrelevant to the effort to forge the new Clean Air Act last fall. Although NAPAP won praise for its scientific accomplishments, the program failed in its primary mission - to provide policy-relevant information in a timely manner. Now, government attempts to deal with the more difficult and far-reaching environmental issues associated with global warming appear to be headed down the same ill-fated path. Global climate change has become the most important environmental issue on the world agenda. The potentially enormous human and ecological implications of global warming - rising sea levels, altered precipitation patterns, and damage to natural ecosystems - have generated concern. But the equally large uncertainties about the timing and magnitude of possible effects, coupled with questions about the costs and impacts of possible abatement measures, have thus far kept policymakers from agreeing on what to do

  13. Assessment of the physical properties and stability of mixtures of tetracycline hydrochloride ointment and acyclovir cream.

    Science.gov (United States)

    Inoue, Yutaka; Furuya, Kayoko; Maeda, Rikimaru; Murata, Isamu; Kanamoto, Ikuo

    2013-04-15

    In dermatology, ointments are often mixed as part of drug therapy, but mixing often leads to incompatibility. Three combinations of tetracycline ointment (TC-o) and acyclovir cream (ACV-cr) were prepared at a TC-o:ACV-cr ratio of 1:1 using a brand-name ACV-cr and two generic ACV-cr (samples TC-o+ACV-A, TC-o+ACV-B, and TC-o+ACV-C). Microscopic examination revealed separation in TC-o+ACV-C. Viscosity and elasticity measurement indicated that the storage modulus (G') and loss modulus (G″) of each of the TC-o+ACV-cr mixtures behaved similarly to those of an ACV-cr and the loss tangent (tanδ) behaved similarly to that of a TC ointment. In addition, differences in the storage modulus (G') and loss modulus (G″) of the TC-o+ACV-cr mixtures were noted. To assess stability, each TC-o+ACV-cr mixture was stored away from direct sunlight at 25 °C and an RH of 84% and at 4 °C (in a refrigerator). HPLC revealed that the ACV content in each TC-o+ACV-cr mixture remained at 95-105% for up to 14 days under both sets of storage conditions. A decline in TC content in each TC-o+ACV-cr mixture was not noted with storage at 4 °C but was noted over time with storage at 25 °C and an RH of 84%. In addition, significant differences in the percent decline in TC content in each TC-o+ACV-cr mixture occurred with storage at 25 °C and an RH of 84%. Thus, differences in physical properties and stability may occur when combining brand-name and generic drugs, and temperature and humidity may be the cause of the TC-o's incompatibility. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  14. Regulation of the pT181 encoded tetracycline resistance gene in Straphylococcus aureus

    International Nuclear Information System (INIS)

    Mojumdar, M.

    1986-01-01

    pT181 is a naturally-occurring 4437 basepair (bp) plasmid isolated from Staphylococcus aureus which encodes inducible resistance to tetracycline (Tc). The DNA sequence data has identified three open reading frames (ORFs). The largest ORF B, has been found to be responsible for the Tc resistance phenotype of pT181. Since most Tc resistance systems appear to be regulated by an effector protein and a repressor protein, several Bal 31 deletion mutants of pT181 were constructed and analyzed in an effort to identify the elements involved in Tc resistance. Two transcomplementing groups of mutants were identified within the tet gene. The mechanism of Tc resistance was studied by assaying the accumulation of [7- 3 H] Tc by Tc sensitive cells, and uninduced and induced pT181-containing cells. A sharp decrease in accumulation of the drug after an initial increase was observed in Tc induced pT181-containing cells. In vivo labeling of Bacillus subtilis minicells containing pT181 was performed with 35 S-methionine to identify the polypeptide product of the tet gene. A Tc-inducible protein having a molecular weight of approximately 50,000 daltons was detected only in B. subtilis minicells carrying pT181. Cell fractionation studies of S. aureus cells with and without pT181 showed that an approximately 28,000 daltons Tc-inducible protein was present in membranes of pT181 containing cells. The amount of TET protein in Tc induced minicells was about fifteen-fold higher than that in uninduced minicells. RNA prepared from stationary phase cells analyzed by Northern blot hybridization showed that the steady-state level of the tet mRNA in induced pT181-containing cells was bout four-fold higher than that in uninduced pT181-containing cells. When RNA synthesis was blocked with rifampicin, tet mRAN was found to be much more stable in Tc induced cells as compared to that in uninduced cells over a 30 min period

  15. Prevalence of tetracycline resistance genes among multi-drug resistant bacteria from selected water distribution systems in southwestern Nigeria.

    Science.gov (United States)

    Adesoji, Ayodele T; Ogunjobi, Adeniyi A; Olatoye, Isaac O; Call, Douglas R; Douglas, Douglas R

    2015-06-25

    Antibiotic resistance genes [ARGs] in aquatic systems have drawn increasing attention they could be transferred horizontally to pathogenic bacteria. Water treatment plants (WTPs) are intended to provide quality and widely available water to the local populace they serve. However, WTPs in developing countries may not be dependable for clean water and they could serve as points of dissemination for antibiotic resistant bacteria. Only a few studies have investigated the occurrence of ARGs among these bacteria including tetracycline resistance genes in water distribution systems in Nigeria. Multi-drug resistant (MDR) bacteria, including resistance to tetracycline, were isolated from treated and untreated water distribution systems in southwest Nigeria. MDR bacteria were resistant to >3 classes of antibiotics based on break-point assays. Isolates were characterized using partial 16S rDNA sequencing and PCR assays for six tetracycline-resistance genes. Plasmid conjugation was evaluated using E. coli strain DH5α as the recipient strain. Out of the 105 bacteria, 85 (81 %) and 20 (19 %) were Gram- negative or Gram- positive, respectively. Twenty-nine isolates carried at least one of the targeted tetracycline resistance genes including strains of Aeromonas, Alcaligenes, Bacillus, Klebsiella, Leucobacter, Morganella, Proteus and a sequence matching a previously uncultured bacteria. Tet(A) was the most prevalent (16/29) followed by tet(E) (4/29) and tet30 (2/29). Tet(O) was not detected in any of the isolates. Tet(A) was mostly found with Alcaligenes strains (9/10) and a combination of more than one resistance gene was observed only amongst Alcaligenes strains [tet(A) + tet30 (2/10), tet(A) + tet(E) (3/10), tet(E) + tet(M) (1/10), tet(E) + tet30 (1/10)]. Tet(A) was transferred by conjugation for five Alcaligenes and two E. coli isolates. This study found a high prevalence of plasmid-encoded tet(A) among Alcaligenes isolates, raising the possibility that this

  16. Class 1 integrons and tetracycline resistance genes in Alcaligenes, Arthrobacter, and Pseudomonas spp. isolated from pigsties and manured soil

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Sandvang, Dorthe

    2005-01-01

    tet(33). No isolates contained more than one tet gene. The in-l-positive isolates were tested for resistance to selected antimicrobial agents and showed resistance to three to nine drugs. Filter-mating experiments showed cotransfer of Tc-r and class I integrons from soil isolates to Escherichia coli...... and/or Pseudomonas putida. We conclude that soil bacteria in close contact to manure or pigsty environment may thus have an important role in horizontal spread of resistance. Use of tetracyclines in food animal production may increase not only Tc-r but also multidrug resistance (caused by the presence...

  17. Identification and Characterization of Fluoroquinolone Non-susceptible Streptococcus pyogenes Clones Harboring Tetracycline and Macrolide Resistance in Shanghai, China

    Science.gov (United States)

    Shen, Yinfang; Cai, Jiehao; Davies, Mark R.; Zhang, Chi; Gao, Kun; Qiao, Dan; Jiang, Haoqin; Yao, Weilei; Li, Yuefang; Zeng, Mei; Chen, Mingliang

    2018-01-01

    Streptococcus pyogenes, also known as group A Streptococcus (GAS), is one of the top 10 infectious causes of death worldwide. Macrolide and tetracycline resistant GAS has emerged as a major health concern in China coinciding with an ongoing scarlet fever epidemic. Furthermore, increasing rates of fluoroquinolone (FQ) non-susceptibility within GAS from geographical regions outside of China has also been reported. Fluoroquinolones are the third most commonly prescribed antibiotic in China and is an therapeutic alternative for multi-drug resistant GAS. The purpose of this study was to investigate the epidemiological and molecular features of GAS fluoroquinolone (FQ) non-susceptibility in Shanghai, China. GAS (n = 2,258) recovered between 2011 and 2016 from children and adults were tested for FQ-non-susceptibility. Efflux phenotype and mutations in parC, parE, gyrA, and gyrB were investigated and genetic relationships were determined by emm typing, pulsed-field gel electrophoresis and phylogenetic analysis. The frequency of GAS FQ-non-susceptibility was 1.3% (30/2,258), with the phenotype more prevalent in GAS isolated from adults (14.3%) than from children (1.2%). Eighty percent (24/30) of FQ-non-susceptible isolates were also resistant to both macrolides (ermB) and tetracycline (tetM) including the GAS sequence types emm12, emm6, emm11, and emm1. Genomic fingerprinting analysis of the 30 isolates revealed that non-susceptibility may arise in various genetic backgrounds even within a single emm type. No efflux phenotype was observed in FQ non-susceptible isolates, and molecular analysis of the quinolone resistance-determining regions (QRDRs) identified several sequence polymorphisms in ParC and ParE, and none in GyrA and GyrB. Expansion of this analysis to 152 publically available GAS whole genome sequences from Hong Kong predicted 7.9% (12/152) of Hong Kong isolates harbored a S79F ParC mutation, of which 66.7% (8/12) were macrolide and tetracycline resistant

  18. Tetracycline and trimethoprim/sulfamethoxazole at clinical laboratory: can they help to characterize Staphylococcus aureus carrying different SCCmec types?

    Science.gov (United States)

    Cavalcante, Fernanda Sampaio; Schuenck, Ricardo Pinto; Caboclo, Roberta Mello Ferreira; Ferreira, Dennis de Carvalho; Nouér, Simone Aranha; Santos, Kátia Regina Netto dos

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) can be difficult to detect at the clinical practice. We analyzed 140 MRSA isolates from inpatients to correlate the antimicrobial susceptibility with the SCCmec types. Type III (n = 63) isolates were more resistant to ciprofloxacin, clindamycin, cloramphenicol, erythromycin, gentamicin, and rifampin than type IV (n = 65) ones (p < 0.05). Moreover, type IV isolates were susceptible to tetracycline (100%) and trimethoprim/sulfamethoxazole (98%), while type III isolates presented resistance to them. In regions where these SCCmec types are prevalent, the detection of specific resistant phenotypes could help to predict them, mainly when there are no technical conditions to SCCmec typing.

  19. Identification and Characterization of Fluoroquinolone Non-susceptible Streptococcus pyogenes Clones Harboring Tetracycline and Macrolide Resistance in Shanghai, China

    Directory of Open Access Journals (Sweden)

    Yinfang Shen

    2018-03-01

    Full Text Available Streptococcus pyogenes, also known as group A Streptococcus (GAS, is one of the top 10 infectious causes of death worldwide. Macrolide and tetracycline resistant GAS has emerged as a major health concern in China coinciding with an ongoing scarlet fever epidemic. Furthermore, increasing rates of fluoroquinolone (FQ non-susceptibility within GAS from geographical regions outside of China has also been reported. Fluoroquinolones are the third most commonly prescribed antibiotic in China and is an therapeutic alternative for multi-drug resistant GAS. The purpose of this study was to investigate the epidemiological and molecular features of GAS fluoroquinolone (FQ non-susceptibility in Shanghai, China. GAS (n = 2,258 recovered between 2011 and 2016 from children and adults were tested for FQ-non-susceptibility. Efflux phenotype and mutations in parC, parE, gyrA, and gyrB were investigated and genetic relationships were determined by emm typing, pulsed-field gel electrophoresis and phylogenetic analysis. The frequency of GAS FQ-non-susceptibility was 1.3% (30/2,258, with the phenotype more prevalent in GAS isolated from adults (14.3% than from children (1.2%. Eighty percent (24/30 of FQ-non-susceptible isolates were also resistant to both macrolides (ermB and tetracycline (tetM including the GAS sequence types emm12, emm6, emm11, and emm1. Genomic fingerprinting analysis of the 30 isolates revealed that non-susceptibility may arise in various genetic backgrounds even within a single emm type. No efflux phenotype was observed in FQ non-susceptible isolates, and molecular analysis of the quinolone resistance-determining regions (QRDRs identified several sequence polymorphisms in ParC and ParE, and none in GyrA and GyrB. Expansion of this analysis to 152 publically available GAS whole genome sequences from Hong Kong predicted 7.9% (12/152 of Hong Kong isolates harbored a S79F ParC mutation, of which 66.7% (8/12 were macrolide and tetracycline resistant

  20. The reactivity of the electron formed in the radiolysis of aerated alkaline aqueous solutions containing tetracycline hydrochloride, at 77 Ksup(+)

    International Nuclear Information System (INIS)

    Guedes, S.M.L.; Vasconcellos, M.B.A.

    1986-01-01

    The radiolysis of tetracycline hydrochloride dissolved in aerated alkaline aqueous solutions containing 0.1, 0.5 and 1M NaOH at 77 K, followed by ESR is reported. The rate constants for the reactions between the electron and physical or chemical traps which are present in these solutions are calculated. The reactivity of electrons that are formed in the radiolysis of water decreases in the following proportions: physical traps: chemical traps: molecules of water (4.8x10sup(14) : 6.5x10sup(8) : 1.0). The electrons react preferentially with the solute instead of the solvent. (author)

  1. Action Learning: Avoiding Conflict or Enabling Action

    Science.gov (United States)

    Corley, Aileen; Thorne, Ann

    2006-01-01

    Action learning is based on the premise that action and learning are inextricably entwined and it is this potential, to enable action, which has contributed to the growth of action learning within education and management development programmes. However has this growth in action learning lead to an evolution or a dilution of Revan's classical…

  2. Comparative evaluation of efficacy of three treatment modalities – tetracycline fibers, scaling and root planing, and combination therapy: A clinical study

    Directory of Open Access Journals (Sweden)

    Aashima Bajaj Dang

    2016-01-01

    Full Text Available Background: Tetracycline is one of the primary antibiotics prescribed for antimicrobial therapy in periodontics. It has a broad spectrum of activity being effective against most bacteria as well as spirochetes. Due to limitations of systemic drug therapy, recent formulations of the drug for local administration in the subgingival area have been introduced, including collagen fibers impregnated with tetracycline. Aims and Objective: To compare the effectiveness of tetracycline fibers alone or in combination with scaling and root planing (SRP on clinical parameters in chronic periodontitis patients. Materials and Methods: A total of twenty patients comprising of both sexes in the age group of 35-60 years with chronic periodontitis were selected. Split-mouth design was used, and three teeth from each patient with periodontal pocket measuring > 5 mm were selected which were treated with different treatment modality. They were randomly divided into site A (SRP, site B (tetracycline fibers only, and site C (combination therapy. Clinical parameters of plaque index (PI, gingival index (GI, pocket probing depth, and clinical attachment level (CAL were recorded at 0, 30, and 45 days. The data obtained was compiled and put to statistical analysis. Results: All the three groups showed improvement in PI, GI, probing pocket depth, and CAL. Results of the study showed greater improvements in clinical parameters in Group C compared to Group A and Group B. Conclusion: The results indicate that the adjunctive use of tetracycline fibers with SRP is a clinically effective and simple nonsurgical treatment method to improve periodontal health.

  3. Effect of Topical Tetracycline Gel with Non Surgical Periodontal Therapy on Hba1c and Lipid Profile in Type 2 Diabetic Patients: A Clinico- Biochemical Study

    Directory of Open Access Journals (Sweden)

    A Haerian-Ardakani

    2014-11-01

    Full Text Available Introduction: The present study aimed to evaluate the Effect of topical tetracycline gel application with non surgical periodontal therapy on HbA1c and lipid profile in type 2 diabetic patients. Methods: A total of 30 type 2 diabetic patients were randomly divided into two groups. The first group received scaling and root planning, whereas the second group received scaling and root planning with topically applied tetracycline gel. Clinical factors such as GI, PI, PPD and biochemical factors such as HbA1c and lipid profile were assessed in beginning of study and 3 months later. Results: Comparing the clinical factors between the two groups revealed that periodontal pocket depth significantly reduced in tetracycline-received group. Regarding the biochemical factors, triglyceride levels decreased significantly in tetracycline-received group. No significant difference was observed between the two groups in regard with other clinical and biochemical factors. Conclusion: The study findings demonstrated that clinical and biochemical parameters have been improved after non surgical periodontal treatment in both groups. Although it seems that application of topical tetracycline gel combined with non-surgical periodontal therapy is effective in improvement of some clinical and biochemical factors like PPD and TG, it doesn’t offer any superiority in regard with other factors compared to mere non surgical periodontal therapy.

  4. A Confirmatory Method Based on HPLC-MS/MS for the Detection and Quantification of Residue of Tetracyclines in Nonmedicated Feed.

    Science.gov (United States)

    Gavilán, Rosa E; Nebot, Carolina; Veiga-Gómez, Maria; Roca-Saavedra, Paula; Vazquez Belda, Beatriz; Franco, Carlos M; Cepeda, Alberto

    2016-01-01

    The Commission Regulation 574/2011/EC set up maximum levels of coccidiostats and histomonostats in nonmedicated feed as a consequence of carry-over during manufacturing. Carry-over takes place from medicated to nonmedicated feed during feed production. Similar contamination could also occur for other pharmaceuticals such as tetracyclines, a group of antibiotics commonly employed in food production animal. The objective of this work is to present a simple and fast method for the simultaneous detection of four tetracyclines (chlortetracycline, doxycycline, oxytetracycline, and tetracycline) in nontarget feed at a μg/kg level. Validation of the method was performed according to the guideline included in the Commission Decision 2002/657/EC for official method. The validated method was successfully applied to 50 feed samples collected from different milk farms and 25 samples obtained from feed manufacturers. While oxytetracycline was the tetracycline most frequently detected, chlortetracycline was the analyte measured at the highest concentration 15.14 mg/Kg. From 75 nonmedicated feed analysed 15% resulted to be positive for the presence of one tetracycline.

  5. 47 CFR 1.425 - Commission action.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Commission action. 1.425 Section 1.425 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Rulemaking Proceedings Rulemaking Proceedings § 1.425 Commission action. The Commission will consider all relevant comments and material of...

  6. ICDF Complex Remedial Action Report

    Energy Technology Data Exchange (ETDEWEB)

    W. M. Heileson

    2007-09-26

    This Idaho CERCLA Disposal Facility (ICDF) Remedial Action Report has been prepared in accordance with the requirements of Section 6.2 of the INEEL CERCLA Disposal Facility Remedial Action Work Plan. The agency prefinal inspection of the ICDF Staging, Storage, Sizing, and Treatment Facility (SSSTF) was completed in June of 2005. Accordingly, this report has been developed to describe the construction activities completed at the ICDF along with a description of any modifications to the design originally approved for the facility. In addition, this report provides a summary of the major documents prepared for the design and construction of the ICDF, a discussion of relevant requirements and remedial action objectives, the total costs associated with the development and operation of the facility to date, and identification of necessary changes to the Agency-approved INEEL CERCLA Disposal Facility Remedial Action Work Plan and the ICDF Complex Operations and Maintenance Plan.

  7. Characterization of tetracycline resistance in Salmonella enterica strains recovered from irrigation water in the Culiacan Valley, Mexico.

    Science.gov (United States)

    Lugo-Melchor, Yadira; Quiñones, Beatriz; Amézquita-López, Bianca A; León-Félix, Josefina; García-Estrada, Raymundo; Chaidez, Cristóbal

    2010-09-01

    The increase of Salmonella enterica strains showing resistance against antibiotics has resulted in limiting the effective treatment of human infections. The present study characterized the resistance to tetracycline in S. enterica serovar Typhimurium strains, recovered from irrigation water in distinct regions in the Culiacan Valley, an important agricultural region in Mexico for horticultural crops that are exported to the United States. Analysis of the genomic diversity by pulse-field gel electrophoresis (PFGE) typing showed that the Salmonella Typhimurium strains were grouped into four distinct genotypic clusters, indicating genomic diversity among 12 strains examined. The polymerase chain reaction and DNA sequencing analysis demonstrated that the tet(A) gene was found on the genomic DNA and was located within a truncated version of transposon Tn1721. The comparative analysis of the tet(A) gene sequence in Salmonella Typhimurium strains identified high sequence similarity to the tet determinant of plasmid RP1, which is homologous to the tet gene in Tn1721. The findings show the presence of tet(A) among the tetracycline-resistant Salmonella Typhimurium strains isolated from irrigation water used for growing fresh fruits and vegetables.

  8. Regenerative potential and anti-bacterial activity of tetracycline loaded apatitic nanocarriers for the treatment of periodontitis

    International Nuclear Information System (INIS)

    Madhumathi, K; Sampath Kumar, T S

    2014-01-01

    Current treatment of periodontal infections includes mechanical debridement, administration of antibiotics and bone grafting. Oral administration of antibiotics results in undesirable side effects, while current modes of local administration are affected by problems concerning allergic response to the polymeric carrier agents. We have developed an osteoconductive drug delivery system composed of apatitic nanocarriers capable of providing sustained delivery of drugs in the periodontium. Calcium deficient hydroxyapatite (CDHA) nanocarriers of different Ca/P ratios were synthesized and characterized using the x-ray diffraction method, transmission electron microscopy, inductively coupled plasma atomic emission spectroscopy, Fourier transform infrared spectroscopy and the BET gas isotherm method. Loading and release studies performed with tetracycline showed a sustained release of up to 88% in phosphate buffered saline over a period of five days. Antibacterial activity studies showed that the tetracycline loaded CDHA (TC-CDHA) nanocarriers were effective against S. aureus and E. coli bacteria. The biocompatibility of the TC-CDHA nanocarriers was demonstrated using an alamar blue assay and further characterized by cell uptake studies. Interestingly, cell uptake of drug loaded CDHA also increased the cellular proliferation of human periodontal ligament fibroblast cells. Hence, it can be concluded that the CDHA nanocarriers are ideal drug delivery agents and have bone regenerative potential for local periodontal applications. (paper)

  9. Comparison of two modified coal ash ferric-carbon micro-electrolysis ceramic media for pretreatment of tetracycline wastewater.

    Science.gov (United States)

    Yang, Kunlun; Jin, Yang; Yue, Qinyan; Zhao, Pin; Gao, Yuan; Wu, Suqing; Gao, Baoyu

    2017-05-01

    Application of modified sintering ferric-carbon ceramics (SFC) and sintering-free ferric-carbon ceramics (SFFC) based on coal ash and scrap iron for pretreatment of tetracycline (TET) wastewater was investigated in this article. Physical property, morphological character, toxic metal leaching content, and crystal component were studied to explore the application possibility of novel ceramics in micro-electrolysis reactors. The influences of operating conditions including influent pH, hydraulic retention time (HRT), and air-water ratio (A/W) on the removal of tetracycline were studied. The results showed that SFC and SFFC were suitable for application in micro-electrolysis reactors. The optimum conditions of SFC reactor were pH of 3, HRT of 7 h, and A/W of 10. For SFFC reactor, the optimum conditions were pH of 2, HRT of 7 h, and A/W of 15. In general, the TET removal efficiency of SFC reactor was better than that of SFFC reactor. However, the harden resistance of SFFC was better than that of SFC. Furthermore, the biodegradability of TET wastewater was improved greatly after micro-electrolysis pretreatment for both SFC and SFFC reactors.

  10. A Simple Model of Tetracycline Antibiotic Resistance in the Aquatic Environment (with Application to the Poudre River

    Directory of Open Access Journals (Sweden)

    Sarah Sanchez

    2011-02-01

    Full Text Available Antibiotic resistance is a major concern, yet it is unclear what causes the relatively high densities of resistant bacteria in the anthropogenically impacted environment. There are various possible scenarios (hypotheses: (A Input of resistant bacteria from wastewater and agricultural sources is significant, but they do not grow in the environment; (B Input of resistant bacteria is negligible, but the resistant bacteria (exogenous or endogenous grow due to the selection pressure of the antibiotic; (C Exogenous bacteria transfer the resistance to the endogenous bacteria and those grow. This paper presents a simple mechanistic model of tetracycline resistance in the aquatic environment. It includes state variables for tetracyclines, susceptible and resistant bacteria, and particulate and dissolved organic matter in the water column and sediment bed. The antibiotic partitions between freely dissolved, dissolved organic matter (DOM-bound and solids-bound phases, and decays. Bacteria growth is limited by DOM, inhibited by the antibiotic (susceptible bacteria only and lower due to the metabolic cost of carrying the resistance (resistant bacteria only. Resistant bacteria can transfer resistance to the susceptible bacteria (conjugation and lose the resistance (segregation. The model is applied to the Poudre River and can reproduce the major observed (literature data patterns of antibiotic concentration and resistance. The model suggests observed densities of resistant bacteria in the sediment bed cannot be explained by input (scenario A, but require growth (scenarios B or C.

  11. Detection of trace tetracycline in fish via synchronous fluorescence quenching with carbon quantum dots coated with molecularly imprinted silica

    Science.gov (United States)

    Yang, Ji; Lin, Zheng-Zhong; Nur, A.-Zha; Lu, Yan; Wu, Ming-Hui; Zeng, Jun; Chen, Xiao-Mei; Huang, Zhi-Yong

    2018-02-01

    A novel fluorescence-based sensor combining synchronous fluorescence spectroscopy (SFS) with molecularly imprinted polymers (MIPs) was fabricated with reverse microemulsion method. Tetracycline (TC), (3-aminopropyl) triethoxysilane (APTES), tetraethyl orthosilicate (TEOS) and carbon quantum dots (CDs) were used as template, functional monomer, cross-linker and signal sources respectively in the probe preparation. A synchronous fluorescence emission (λem) at 355 nm was observed for the prepared MIP-coated CDs (MIP@CDs) particles when the wavelength interval (Δλ) was set as 70 nm, and the synchronous fluorescence intensity could be rapidly and efficiently quenched by TC based on inner filter effect (IFE). The quenching efficiencies of synchronous fluorescence intensity was linearly fitted with tetracycline (TC) concentrations ranging from 0.1 to 50 μmol L- 1 with a detection limit (DL) of 9 nmol L- 1 (3σ, n = 9). The MIP@CDs was used as a probe to detect TC in fish samples with the recoveries ranging from 98.4% to 103.1% and the relative standard deviation less than 6.0%. The results illustrated that the as-prepared MIP@CDs could be applied to the detection of trace TC in fish samples with rapidity, high sensitivity and accuracy.

  12. Transferability of a tetracycline resistance gene from probiotic Lactobacillus reuteri to bacteria in the gastrointestinal tract of humans.

    Science.gov (United States)

    Egervärn, Maria; Lindmark, Hans; Olsson, Johan; Roos, Stefan

    2010-02-01

    The potential of Lactobacillus reuteri as a donor of antibiotic resistance genes in the human gut was investigated by studying the transferability of the tetracycline resistance gene tet(W) to faecal enterococci, bifidobacteria and lactobacilli. In a double-blind clinical study, seven subjects consumed L. reuteri ATCC 55730 harbouring a plasmid-encoded tet(W) gene (tet(W)-reuteri) and an equal number of subjects consumed L. reuteri DSM 17938 derived from the ATCC 55730 strain by the removal of two plasmids, one of which contained the tet(W) gene. Faecal samples were collected before, during and after ingestion of 5 x 10(8) CFU of L. reuteri per day for 14 days. Both L. reuteri strains were detectable at similar levels in faeces after 14 days of intake but neither was detected after a two-week wash-out period. After enrichment and isolation of tetracycline resistant enterococci, bifidobacteria and lactobacilli from each faecal sample, DNA was extracted and analysed for presence of tet(W)-reuteri using a real-time PCR allelic discrimination method developed in this study. No tet(W)-reuteri signal was produced from any of the DNA samples and thus gene transfer to enterococci, bifidobacteria and lactobacilli during intestinal passage of the probiotic strain was non-detectable under the conditions tested, although transfer at low frequencies or to the remaining faecal bacterial population cannot be excluded.

  13. Monitoring of drug resistance amplification and attenuation with the use of tetracycline-resistant bacteria during wastewater treatment

    Science.gov (United States)

    Harnisz, Monika; Korzeniewska, Ewa; Niestępski, Sebastian; Osińska, Adriana; Nalepa, Beata

    2017-11-01

    The objective of this study was to monitor changes (amplification or attenuation) in antibiotic resistance during wastewater treatment based on the ecology of tetracycline-resistant bacteria. The untreated and treated wastewater were collected in four seasons. Number of tetracycline-(TETR) and oxytetracycline-resistant (OTCR) bacteria, their qualitative composition, minimum inhibitory concentrations (MICs), sensitivity to other antibiotics, and the presence of tet (A, B, C, D, E) resistance genes were determined. TETR and OTCR counts in untreated wastewater were 100 to 1000 higher than in treated effluent. OTCR bacterial counts were higher than TETR populations in both untreated and treated wastewater. TETR isolates were not dominated by a single bacterial genus or species, whereas Aeromonas hydrophila and Aeromonas sobria were the most common in OTCR isolates. The treatment process attenuated the drug resistance of TETR bacteria and amplified the resistance of OTCR bacteria. In both microbial groups, the frequency of tet(A) gene increased in effluent in comparison with untreated wastewater. Our results also indicate that treated wastewater is a reservoir of multiple drug-resistant bacteria as well as resistance determinants which may pose a health hazard for humans and animals when released to the natural environment.

  14. Simultaneous removal and degradation characteristics of sulfonamide, tetracycline, and quinolone antibiotics by laccase-mediated oxidation coupled with soil adsorption.

    Science.gov (United States)

    Ding, Huijun; Wu, Yixiao; Zou, Binchun; Lou, Qian; Zhang, Weihao; Zhong, Jiayou; Lu, Lei; Dai, Guofei

    2016-04-15

    The uses of laccase in the degradation and removal of antibiotics have recently been reported because of the high efficiency and environmental friendliness of laccase. However, these removal studies mostly refer to a limited number of antibiotics. In this study, soil adsorption was introduced into the laccase-oxidation system to assist the simultaneous removal of 14 kinds of sulfonamide, tetracycline, and quinolone antibiotics, which differed in structures and chemical properties. The complementary effects of laccase-mediated oxidation and soil adsorption enabled the simultaneous removal. Removal characteristics were determined by a comprehensive consideration of the separate optimum conditions for laccase oxidation and soil adsorption removal experiments. With concentrations of laccase, syringaldehyde (SA), and soil of 0.5mg/mL, 0.5mmol/L, and 50g/L, respectively, and at pH 6 and 25°C, the removal rates of each antibiotic exceeded 70% in 15min and were close to 100% in 180min. Sulfonamide antibiotics (SAs) were removed mainly by laccase oxidation and quinolone antibiotics (QUs) mainly by soil adsorption. Tetracycline antibiotics (TCs) were removed by both treatments in the coupled system, but laccase oxidation dominated. Electrostatic adsorption was speculated to be one of the adsorption mechanisms in soil adsorption with QUs and TCs. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Detection and linkage to mobile genetic elements of tetracycline resistance gene tet(M) in Escherichia coli isolates from pigs

    DEFF Research Database (Denmark)

    Jurado-Rabadan, Sonia; de la Fuente, Ricardo; Ruiz-Santa-Quiteria, Jose A.

    2014-01-01

    from pigs, as well as the detection of mobile genetic elements linked to tet(M) in E. coli and its possible transfer from enterococci. Results: tet(A) was the most frequently detected gene (87.9%) in doxycycline-resistant isolates. tet(M) was found in 13.1% E. coli isolates. The tet(M) gene......Background: In Escherichia coli the genes involved in the acquisition of tetracycline resistance are mainly tet(A) and tet(B). In addition, tet(M) is the most common tetracycline resistance determinant in enterococci and it is associated with conjugative transposons and plasmids. Although tet......(M) has been identified in E. coli, to our knowledge, there are no previous reports studying the linkage of the tet(M) gene in E. coli to different mobile genetic elements. The aim of this study was to determine the occurrence of tet(A), tet(B), and tet(M) genes in doxycycline-resistant E. coli isolates...

  16. Previously undescribed plasmids recovered from activated sludge confer tetracycline resistance and phenotypic changes to Acinetobacter oleivorans DR1.

    Science.gov (United States)

    Hong, Hyerim; Ko, Hyeok-Jin; Choi, In-Geol; Park, Woojun

    2014-02-01

    We used culture-dependent and culture-independent methods to extract previously undescribed plasmids harboring tetracycline (TC) resistance genes from activated sludge. The extracted plasmids were transformed into naturally competent Acinetobacter oleivorans DR1 to recover a non-Escherichia coli-based plasmid. The transformed cells showed 80-100-fold higher TC resistance than the wild-type strain. Restriction length polymorphism performed using 30 transformed cells showed four different types of plasmids. Illumina-based whole sequencing of the four plasmids identified three previously unreported plasmids and one previously reported plasmid. All plasmids carried TC resistance-related genes (tetL, tetH), tetracycline transcriptional regulators (tetR), and mobilization-related genes. As per expression analysis, TC resistance genes were functional in the presence of TC. The recovered plasmids showed mosaic gene acquisition through horizontal gene transfer. Membrane fluidity, hydrophobicity, biofilm formation, motility, growth rate, sensitivity to stresses, and quorum sensing signals of the transformed cells were different from those of the wild-type cells. Plasmid-bearing cells seemed to have an energy burden for maintaining and expressing plasmid genes. Our data showed that acquisition of TC resistance through plasmid uptake is related to loss of biological fitness. Thus, cells acquiring antibiotic resistance plasmids can survive in the presence of antibiotics, but must pay ecological costs.

  17. Solvent extraction of some fission products using tetracycline as a complexing agent : dependence on the ph of the aqueous phase and on the nature of some inorganic anions

    International Nuclear Information System (INIS)

    Cunha, I.I.L.; Nastasi, M.J.C.

    1982-10-01

    The behavior of tetracycline as a complexing agent in solvent extraction studies is presented. The extraction curves for the fission products 90 Sr, 140 Ba, 99 Mo, sup(99m)Tc, 95 Zr, 95 Nb, 103 Ru and also for U have been determined for the extraction system tetracycline-benzyl alcohol. The extraction dependence on the pH of the aqueous phase as well as on the kind of electrolyte present was examined. As a practical application, the possiblity of using the tetracycline-benzyl alcohol system for separation of the fission products present in a mixture of them, as well as for the separation of uranium from those elements, was tested. (Author) [pt

  18. Study of the effect of gamma radiation on the molecule of tetracycline concerning its behavior as complexing and extracting agent; Estudo do efeito da radiacao gama sobre a molecula de tetraciclina relativamente ao seu comportamento como agente complexante e extrator

    Energy Technology Data Exchange (ETDEWEB)

    Andrade e Silva, Leonardo Gondim de

    1982-07-01

    Both solvent extraction and spectrophotometric techniques were used to show the alterations that gamma radiation causes in the behavior of tetracycline molecule as far as its extracting and complexing power are concerned. The effect of gamma radiation on the solid tetracycline molecule, benzyl alcohol and on the solution of both was examined in solvent extraction systems whose aqueous phases were made up by {sup 152} Eu-{sup 154}Eu radioactive tracer solutions and whose organic phases were constituted by tetracycline-benzyl alcohol solutions. Experiments were performed in order to determine whether or not the water used for the pre-saturation of benzyl alcohol would influence the radiolysis of tetracycline. Solvent extraction and spectrophotometry were the techniques used to obtain the necessary data. Absorption spectra of irradiated tetracycline benzyl alcohol solutions submitted to several gamma radiation doses were examined and the alterations shown by these spectra were examined. The effect of gamma radiation on the tetracycline molecule was also studied when tetracycline-benzyl alcohol solutions were irradiated under several gaseous atmospheres, namely: O{sub 2}, N{sub 2}, SF{sub 6} and N{sub 2}O. The variation on the concentration of the tetracycline-benzyl alcohol solution caused by several doses of gamma radiation was determined by using the spectrophotometric technique. (author)

  19. User perspectives on relevance criteria

    DEFF Research Database (Denmark)

    Maglaughlin, Kelly L.; Sonnenwald, Diane H.

    2002-01-01

    , partially relevant, or not relevant to their information need; and explained their decisions in an interview. Analysis revealed 29 criteria, discussed positively and negatively, that were used by the participants when selecting passages that contributed or detracted from a document's relevance...... implications for relevance feedback in information retrieval systems, suggesting that systems accept and utilize multiple positive and negative relevance criteria from users. Systems designers may want to focus on supporting content criteria followed by full text criteria as these may provide the greatest cost....... These criteria can be grouped into six categories: abstract (e.g., citability, informativeness), author (e.g., novelty, discipline, affiliation, perceived status), content (e.g., accuracy/validity, background, novelty, contrast, depth/scope, domain, citations, links, relevant to other interests, rarity, subject...

  20. Action learning across the decades.

    Science.gov (United States)

    Eason, Ken

    2017-05-02

    Purpose The purpose of this paper is to explore how action learning concepts were used in two healthcare projects undertaken many decades apart. The specific purpose in both cases was to examine how action learning can contribute to shared learning across key stakeholders in a complex socio-technical system. In each case study, action learning supported joint design programmes and the sharing of perspectives about the complex system under investigation. Design/methodology/approach Two action learning projects are described: first, the Hospital Internal Communications (HIC) project led by Reg Revans in the 1960s. Senior staff in ten London hospitals formed action learning teams to address communication issues. Second, in the Better Outcomes for People with Learning Disabilities: Transforming Care (BOLDTC) project, videoconferencing equipment enabled people with learning disabilities to increase their opportunities to communicate. A mutual learning process was established to enable stakeholders to explore the potential of the technical system to improve individual care. Findings The HIC project demonstrated the importance of evidence being shared between team members and that action had to engage the larger healthcare system outside the hospital. The BOLDTC project confirmed the continuing relevance of action learning to healthcare today. Mutual learning was achieved between health and social care specialists and technologists. Originality/value This work draws together the socio-technical systems tradition (considering both social and technical issues in organisations) and action learning to demonstrate that complex systems development needs to be undertaken as a learning process in which action provides the fuel for learning and design.

  1. Current status of Helicobacter pylori resistance to tetracycline: a systematic review of the literature

    OpenAIRE

    Ramírez-Bulla, Paola; Grupo de Enfermedades Infecciosas. Departamento de Microbiología. Facultad de Ciencias. Pontificia Universidad Javeriana. Bogotá, D.C.; Mercado-Reyes, Marcela; Grupo de Enfermedades Infecciosas. Departamento de Microbiología. Facultad de Ciencias. Pontificia Universidad Javeriana. Bogotá, D.C.; Trespalacios-Rangel, Alba Alicia; Grupo de Enfermedades Infecciosas. Departamento de Microbiología. Facultad de Ciencias. Pontificia Universidad Javeriana. Bogotá, D.C.,; Avila-Coy, Jenny; Grupo de Enfermedades Infecciosas. Departamento de Microbiología. Facultad de Ciencias. Pontificia Universidad Javeriana. Bogotá, D.C.,; Otero-Regino, William; Unidad de Gastroenterología, Universidad Nacional de Colombia, Bogotá, D.C.

    2012-01-01

    Objective. To determine the prevalence of Helicobacter pylori resistance to and the possible mutations that generate this worldwide resistance. Materials and methods. A systematic search for literature was performed in the databases Medline, Science Direct (Elsevier), Ovid, PubMed, Lilacsand MedicLatina using relevant key words. Data extraction was independent and checklists were prepared to assess the methodologicalquality of the studies. Analysis of information was done with RevMan 5®. Resu...

  2. Visible active N-doped TiO2/reduced graphene oxide for the degradation of tetracycline hydrochloride

    Science.gov (United States)

    Tang, Xinde; Wang, Zhengrong; Wang, Yue

    2018-01-01

    N-doped TiO2 nanoparticles deposited on reduced graphene oxide sheets were successfully prepared by a photoreduction method. The synthesized N-TiO2/rGO composite was characterized by XRD, SERS, XPS, TEM, UV-vis DRS and PL, and its visible-light photocatalytic activity was evaluated by degradation of tetracycline hydrochloride (TC). The results showed that N-TiO2/rGO composites exhibited a more enhanced photodegradation activity compared to pure TiO2 and N-doped TiO2. Trapping tests indicated that not radOH and h+ but radO2- was chiefly responsible for the photodegradation process. The reusable experiments showed that the prepared N-TiO2/rGO catalyst was stable during the photodegradation of TC.

  3. Novel plasmid conferring kanamycin and tetracycline resistance in the turkey-derived Campylobacter jejuni strain 11601MD.

    Science.gov (United States)

    Crespo, M D; Altermann, E; Olson, J; Miller, W G; Chandrashekhar, K; Kathariou, S

    2016-07-01

    In Campylobacter spp., resistance to the antimicrobials kanamycin and tetracycline is frequently associated with plasmid-borne genes. However, relatively few plasmids of Campylobacter jejuni have been fully characterized to date. A novel plasmid (p11601MD; 44,095nt) harboring tet(O) was identified in C. jejuni strain 11601MD, which was isolated from the jejunum of a turkey produced conventionally in North Carolina. Analysis of the p11601MD sequence revealed the presence of a high-GC content cassette with four genes that included tet(O) and a putative aminoglycoside transferase gene (aphA-3) highly similar to kanamycin resistance determinants. Several genes putatively involved in conjugative transfer were also identified on the plasmid. These findings will contribute to a better understanding of the distribution of potentially self-mobilizing plasmids harboring antibiotic resistance determinants in Campylobacter spp. from turkeys and other sources. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Effect of tetracycline dose and treatment-mode on selection of resistant coliform bacteria in nursery pigs

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Damborg, Peter; Mellerup, Anders

    2017-01-01

    , and there is a need to improve the ways that we use antimicrobial in livestock production. We hypothesized that antibiotic resistance development following treatment of diarrhea in nursery pigs could be reduced by either lowering the dose of oxytetracycline or by replacing the commonly used practice of flock......This study describes results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on selection of antibiotic resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4-7 weeks of age) were treated....../kg), and (v) individual intramuscular injection treatment (10mg/kg). All groups were treated once a day for five days. In all groups, treatment caused a rise in numbers and proportion of tetracycline resistant coliform bacteria right after treatment, followed by a significant drop by the time where pigs left...

  5. The reverse tetracycline-controlled transactivator rtT A2s-S2 is toxic in mouse embryonic stem cells

    Czech Academy of Sciences Publication Activity Database

    Bryja, Vítězslav; Pachernik, J.; Kubala, L.; Hampl, Aleš; Dvořák, Petr

    2003-01-01

    Roč. 43, č. 6 (2003), s. 477-486 ISSN 0926-5287 R&D Projects: GA ČR GA204/01/0905; GA MŠk LN00A065 Institutional research plan: CEZ:AV0Z5039906 Keywords : tetracycline-controlled Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.780, year: 2003

  6. Human T47D-ERß breast cancer cells with tetracycline-dependent ERß expression reflect ERa/ERß ratios in rat and human breast tissue

    NARCIS (Netherlands)

    Evers, N.M.; Klundert, van de T.M.C.; Aesch, van Y.M.; Wang, S.; Roos, de W.K.; Romano, A.; Haan, de L.H.J.; Murk, A.J.; Ederveen, A.G.H.; Rietjens, I.M.C.M.; Groten, J.P.

    2013-01-01

    T47D-ER beta breast cancer cells with tetracycline-dependent ER beta expression and constant ER alpha expression can be used to investigate effects of varying ER alpha/ER beta ratios on estrogen-induced cellular responses. This study defines conditions at which ER alpha/ER beta ratios in T47D-ER

  7. Method of analysis for the determination of tetracycline rsidues in meat, kidney, fat, skin, fish, egg and milk : procedure and validation

    NARCIS (Netherlands)

    Keukens, H.J.

    1994-01-01

    The aim of this study was to validate the RIKILT-DLO method tor the determination of tetracycline in liver, kidney, fat or skin with adhering fat for from chickens, cows and skin with adhering fat from pigs. The method was originally validated for meat of different animals, eggs milk, fish, liver

  8. The combined use of enamel matrix proteins and a tetracycline-coated expanded polytetrafluoroethylene barrier membrane in the treatment of intra-osseous defects

    NARCIS (Netherlands)

    Sipos, PM; Loos, BG; Abbas, F; Timmerman, MF; van der Velden, U

    Objectives: The purpose of this split-mouth study was to evaluate the clinical response of enamel matrix proteins (EMPs, Emdogain Gel((R))) in intra-osseous defects with or without a combined application of a tetracycline-coated expanded polytetrafluoroethylene barrier membrane (e-PTFE,

  9. Development and validation of multi-residue analysis for tetracycline antibiotics in feed by high performance liquid chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Patyra, Ewelina; Kwiatek, Krzysztof

    2017-09-01

    A new multi-residue method for the analysis of the tetracycline antibiotics oxytetracycline, tetracycline, chlortetracycline, and doxycycline was developed and validated for animal feed. After extraction with 0.1M Na 2 EDTA-McIlvaine buffer (pH 4), the samples were centrifuged, purified by SPE (Strata-X-CW cartridges) and analysed by HPLC-MS. Validation of the method was performed according to the guidelines indicated in European Commission Decision 2002/657/EC. The procedure was validated by spiking feed samples at three different levels (300, 1000, and 5000 µg/kg). Average recoveries for tetracyclines were in the range 79.70-98.8%, with RSD for repeatability and reproducibility in the ranges of 5.0-9.5% and 6.5-11.0%, respectively. The method was successfully validated and proved to be efficient, precise, and useful for quantification of tetracyclines in animal feed. The validated method was successfully applied to 65 suspect feed samples collected from different regions of Poland in 2015-16 and obtained from farms and feed manufactures. Of these 65 purportedly non-medicated feeds, eight (12.3%) were positive for the presence of doxycycline or chlortetracycline.

  10. Two Different Tetracycline Resistance Mechanisms, Plasmid-Carried tet(L) and Chromosomally Located Transposon-Associated tet(M), Coexist in Lactobacillus sakei Rits 9

    NARCIS (Netherlands)

    Ammor, M.S.; Gueimonde, M.; Danielsen, M.; Zagorec, M.; Hoek, van A.H.A.M.; Reyes-Gavilán, de los C.G.; Mayo, B.; Margolles, A.

    2008-01-01

    Lactobacillus sakei is extensively used as functional starter culture in fermented meat products. One of the safety criteria of a starter culture is the absence of potentially transferable antibiotic resistance determinants. However, tetracycline-resistant L. sakei strains have already been

  11. Research note: effect of tetracycline hydrochloride and oxytetracycline hydrochloride given via drinking water on early mortality of broiler chicks from twenty-eight-week-old dams.

    Science.gov (United States)

    Peterson, R A; Carpenter, G H; Jones, W T; Kula, J A

    1991-04-01

    The effect of tetracycline HCl and oxytetracycline HCl on early mortality in straight-run Peterson x Hubbard cross broiler chicks from 28-wk-old dams was studied. Treatments consisted of a sham-treated control, and groups treated with a tetracycline either HCl (25 mg/454 g of BW per day) or an oxytetracycline HCl (14.6 mg/454 g of BW per day). Each group was treated via the drinking water for the first 5 days after hatching. There were 24 replications per treatment with 54 chicks each. Birds were maintained at a density of 622.5 cm2 per chick. Chicks treated with tetracycline HCl and oxytetracycline HCl had significantly (P less than .05) improved livability when compared with the sham-treated controls both at 2 and 6 wk of age (1.00 and .83 versus 1.79 at 2 wk, and 2.79 and 3.29 versus 4.29% mortality at 6 wk, respectively). No significant differences in mortality were observed between tetracycline HCl-treated chicks and oxytetracycline HCl-treated chicks. At the end of the 6-wk trial, no differences between treatments were seen in the productive performance of the broilers. The observed differences in livability at 6 wk of age could increase the number of saleable broilers by 10 to 15 thousand per million chicks placed.

  12. Comparative activity of tigecycline and tetracycline on Gram-negative and Gram-positive bacteria revealed by a multicentre study in four North European countries

    DEFF Research Database (Denmark)

    Nilsson, Lennart E; Frimodt-Møller, Niels; Vaara, Martti

    2011-01-01

    This study involves a multicentre surveillance of tigecycline and tetracycline activity against Gram-negative and Gram-positive bacteria from primary care centres (PCCs), general hospital wards (GHWs) and intensive care units (ICUs) in Denmark (n = 9), Finland (n = 10), Norway (n = 7) and Sweden (n...

  13. A transgenic mouse line for collecting ribosome-bound mRNA using the tetracycline transactivator system

    Directory of Open Access Journals (Sweden)

    Laurel eDrane

    2014-10-01

    Full Text Available Acquiring the gene expression profiles of specific neuronal cell-types is important for understanding their molecular identities. Genome-wide gene expression profiles of genetically defined cell-types can be acquired by collecting and sequencing mRNA that is bound to epitope-tagged ribosomes (TRAP; Translating Ribosome Affinity Purification. Here, we introduce a transgenic mouse model that combines the TRAP technique with the tetracycline transactivator (tTA system by expressing EGFP-tagged ribosomal protein L10a (EGFP-L10a under control of the tetracycline response element (tetO-TRAP. This allows both spatial control of EGFP-L10a expression through cell-type specific tTA expression, as well as temporal regulation by inhibiting transgene expression through the administration of doxycycline. We show that crossing tetO-TRAP mice with transgenic mice expressing tTA under the Camk2a promoter (Camk2a-tTA results in offspring with cell-type specific expression of EGFP-L10a in CA1 pyramidal neurons and medium spiny neurons in the striatum. Co-immunoprecipitation confirmed that EGFP-L10a integrates into a functional ribosomal complex. In addition, collection of ribosome-bound mRNA from the hippocampus yielded the expected enrichment of genes expressed in CA1 pyramidal neurons, as well as a depletion of genes expressed in other hippocampal cell-types. Finally, we show that crossing tetO-TRAP mice with transgenic Fos-tTA mice enables the expression of EGFP-L10a in CA1 pyramidal neurons that are activated during a fear conditioning trial. The tetO-TRAP mouse can be combined with other tTA mouse lines to enable gene expression profiling of a variety of different cell-types.

  14. Biosynthesis of Oxytetracycline by Streptomyces rimosus: Past, Present and Future Directions in the Development of Tetracycline Antibiotics

    Directory of Open Access Journals (Sweden)

    Hrvoje Petković

    2017-01-01

    Full Text Available Natural tetracycline (TC antibiotics were the first major class of therapeutics to earn the distinction of ‘broad-spectrum antibiotics’ and they have been used since the 1940s against a wide range of both Gram-positive and Gram-negative pathogens, mycoplasmas, intracellular chlamydiae, rickett siae and protozoan parasites. The second generation of semisynthetic tetracyclines, such as minocycline and doxycycline, with improved antimicrobial potency, were introduced during the 1960s. Despite emerging resistance to TCs erupting during the 1980s, it was not until 2006, more than four decades later, that a third-generation TC, named tigecycline, was launched. In addition, two TC analogues, omadacycline and eravacycline, developed via (semisynthetic and fully synthetic routes, respectively, are at present under clinical evaluation. Interestingly, despite very productive early work on the isolation of a Streptomyces aureofaciens mutant strain that produced 6-demethyl-7-chlortetracycline, the key intermediate in the production of second- and third-generation TCs, biosynthetic approaches in TC development have not been productive for more than 50 years. Relatively slow and tedious molecular biology approaches for the genetic manipulation of TC-producing actinobacteria, as well as an insufficient understanding of the enzymatic mechanisms involved in TC biosynthesis have significantly contributed to the low success of such biosynthetic engineering efforts. However, new opportunities in TC drug development have arisen thanks to a signifi cant progress in the development of affordable and versatile biosynthetic engineering and synthetic biology approaches, and, importantly, to a much deeper understanding of TC biosynthesis, mostly gained over the last two decades.

  15. Structural and Biochemical Characterization of the Salicylyl-acyltranferase SsfX3 from a Tetracycline Biosynthetic Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Pickens, Lauren B.; Sawaya, Michael R.; Rasool, Huma; Pashkov, Inna; Yeates, Todd O.; Tang, Yi (UCLA)

    2012-03-14

    SsfX3 is a GDSL family acyltransferase that transfers salicylate to the C-4 hydroxyl of a tetracycline intermediate in the penultimate step during biosynthesis of the anticancer natural product SF2575. The C-4 salicylate takes the place of the more common C-4 dimethylamine functionality, making SsfX3 the first acyltransferase identified to act on a tetracycline substrate. The crystal structure of SsfX3 was determined at 2.5 {angstrom}, revealing two distinct domains as follows: an N-terminal {beta}-sandwich domain that resembles a carbohydrate-binding module, and a C-terminal catalytic domain that contains the atypical {alpha}/{beta}-hydrolase fold found in the GDSL hydrolase family of enzymes. The active site lies at one end of a large open binding pocket, which is spatially defined by structural elements from both the N- and C-terminal domains. Mutational analysis in the putative substrate binding pocket identified residues from both domains that are important for binding the acyl donor and acceptor. Furthermore, removal of the N-terminal carbohydrate-binding module-like domain rendered the stand-alone {alpha}/{beta}-hydrolase domain inactive. The additional noncatalytic module is therefore proposed to be required to define the binding pocket and provide sufficient interactions with the spatially extended tetracyclic substrate. SsfX3 was also demonstrated to accept a variety of non-native acyl groups. This relaxed substrate specificity toward the acyl donor allowed the chemoenzymatic biosynthesis of C-4-modified analogs of the immediate precursor to the bioactive SF2575; these were used to assay the structure activity relationships at the C-4 position.

  16. Omeprazole, Furazolidone, and Tetracycline: an eradication treatment for resistant H. pylori in Brazilian patients with peptic ulcer disease

    Directory of Open Access Journals (Sweden)

    Silva Fernando Marcuz

    2002-01-01

    Full Text Available OBJECTIVES: To determine the efficacy of a simple, short-term and low-cost eradication treatment for Helicobacter pylori (H. pylori using omeprazole, tetracycline, and furazolidone in a Brazilian peptic ulcer population, divided into 2 subgroups: untreated and previously treated for the infection. PATIENTS AND METHODS: Patients with peptic ulcer disease diagnosed by endoscopic examination and infected by H. pylori diagnosed by the rapid urease test (RUT and histological examination, untreated and previously unsuccessfully treated by macrolides and nitroimidazole, were medicated with omeprazole 20 mg daily dose and tetracycline 500 mg and furazolidone 200 mg given 3 times a day for 7 days. Another endoscopy or a breath test was performed 12 weeks after the end of treatment. Patients were considered cured of the infection if a RUT and histologic examination proved negative or a breath test was negative for the bacterium. RESULTS: Sixty-four patients were included in the study. The women were the predominant sex (58%; the mean age was 46 years. Thirty-three percent of the patients were tobacco users, and duodenal ulcer was identified in 80% of patients. For the 59 patients that underwent follow-up examinations, eradication was verified in 44 (75%. The eradication rate for the intention-to-treat group was 69%. The incidence of severe adverse effects was 15%. CONCLUSION: The treatment provides good efficacy for H. pylori eradication in patients who were previously treated without success, but it causes severe adverse effects that prevented adequate use of the medications in 15% of the patients.

  17. Prevalence of sulfonamide and tetracycline resistance genes in drinking water treatment plants in the Yangtze River Delta, China.

    Science.gov (United States)

    Guo, Xueping; Li, Jing; Yang, Fan; Yang, Jie; Yin, Daqiang

    2014-09-15

    The occurrence and distribution of antibiotic resistance genes (ARGs) in drinking water treatment plants (DWTPs) and finished water are not well understood, and even less is known about the contribution of each treatment process to resistance gene reduction. The prevalence of ten commonly detected sulfonamide and tetracycline resistance genes, namely, sul I, sul II, tet(C), tet(G), tet(X), tet(A), tet(B), tet(O), tet(M) and tet(W) as well as 16S-rRNA genes, were surveyed in seven DWTPs in the Yangtze River Delta, China, with SYBR Green I-based real-time quantitative polymerase chain reaction. All of the investigated ARGs were detected in the source waters of the seven DWTPs, and sul I, sul II, tet(C) and tet(G) were the four most abundant ARGs. Total concentrations of ARGs belonging to either the sulfonamide or tetracycline resistance gene class were above 10(5) copies/mL. The effects of a treatment process on ARG removal varied depending on the overall treatment scheme of the DWTP. With combinations of the treatment procedures, however, the copy numbers of resistance genes were reduced effectively, but the proportions of ARGs to bacteria numbers increased in several cases. Among the treatment processes, the biological treatment tanks might serve as reservoirs of ARGs. ARGs were found in finished water of two plants, imposing a potential risk to human health. The results presented in this study not only provide information for the management of antibiotics and ARGs but also facilitate improvement of drinking water quality. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Novel Bi2WO6-coupled Fe3O4Magnetic Photocatalysts: Preparation, Characterization and Photodegradation of Tetracycline Hydrochloride.

    Science.gov (United States)

    Wang, Tianye; Zhong, Shuang; Zou, Shuang; Jiang, Fuhuan; Feng, Limin; Su, Xiaosi

    2017-07-01

    Novel Bi 2 WO 6 -coupled Fe 3 O 4 magnetic photocatalysts with excellent and stable photocatalytic activity for degrading tetracycline hydrochloride and RhB were successfully synthesized via a facile solvothermal route. Through the characterization of the as-prepared magnetic photocatalysts by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectra, it was found that the as-prepared magnetic photocatalysts were synthesized by the coupling of Bi 2 WO 6 and Fe 3 O 4 , and introduction of appropriated Fe 3 O 4 can improve nanospheres morphology and visible-light response. Among them, BFe2 (0.16% Fe 3 O 4 ) exhibited the best photocatalytic activity for degradation of tetracycline hydrochloride (TCH), reaching 81.53% after 90 min. Meanwhile, the as-prepared magnetic photocatalysts showed great separation and recycle property. Moreover, the results of electrochemical impedance spectroscopy demonstrated that the well conductivity of Fe 3 O 4 can promote photogenerated charge carriers transfer and inhibit recombination of electron-hole pairs, so that Bi 2 WO 6 /Fe 3 O 4 exhibited enhanced photocatalytic activity on degradation of TCH and RhB. Hence, this work provides a principle method to synthesize Bi 2 WO 6 /Fe 3 O 4 with excellent photocatalytic performance for actual application, in addition, it showed that introduction of Fe 3 O 4 not only can provide magnetism, but also can enhance photocatalytic activity of Bi 2 WO 6 /Fe 3 O 4 magnetic photocatalysts. © 2017 The American Society of Photobiology.

  19. Controlled-release of tetracycline and lovastatin by poly(d,l-lactide-co-glycolide acid)-chitosan nanoparticles enhances periodontal regeneration in dogs

    Science.gov (United States)

    Lee, Bor-Shiunn; Lee, Chien-Chen; Wang, Yi-Ping; Chen, Hsiao-Jan; Lai, Chern-Hsiung; Hsieh, Wan-Ling; Chen, Yi-Wen

    2016-01-01

    Chronic periodontitis is characterized by inflammation of periodontal tissues, leading to bone resorption and tooth loss. The goal of treatment is to regenerate periodontal tissues including bone and cementum lost as a consequence of disease. The local delivery of tetracycline was proven to be effective in controlling localized periodontal infection without apparent side effects. Previous studies suggested that lovastatin has a significant role in new bone formation; however, the local delivery of lovastatin might enhance its therapeutic effects. A number of local delivery devices have been developed recently, including poly(d,l-lactide-co-glycolide acid) (PLGA) nanoparticles. The aim of this study was to develop a local delivery device, PLGA-lovastatin-chitosan-tetracycline nanoparticles, which allows the sequential release of tetracycline and lovastatin to effectively control local infection and promote bone regeneration in periodontitis. The size and microstructure of nanoparticles were examined by transmission electron microscopy, Nanoparticle Size Analyzer, and Fourier transform infrared spectroscopy. The release of tetracycline and lovastatin was quantified using a UV-Vis spectrophotometer. Furthermore, the cytotoxic effect and alkaline phosphatase activity of the nanoparticles in osteoblast cell cultures as well as antibacterial activity against periodontal pathogens were investigated. Finally, the bone regeneration potential of PLGA nanoparticles in three-walled defects in beagle dogs was investigated. The results indicated that PLGA-lovastatin-chitosan-tetracycline nanoparticles showed good biocompatibility, antibacterial activity, and increased alkaline phosphatase activity. The volumetric analysis from micro-CT revealed significantly increased new bone formation in defects filled with nanoparticles in dogs. This novel local delivery device might be useful as an adjunctive treatment in periodontal regenerative therapy. PMID:26848264

  20. Great improvement on tetracycline removal using ZnO rod-activated carbon fiber composite prepared with a facile microwave method

    Energy Technology Data Exchange (ETDEWEB)

    Tran Thi, Viet Ha; Lee, Byeong-Kyu, E-mail: bklee@ulsan.ac.kr

    2017-02-15

    Highlights: • ZnO rod-ACF was prepared by a method involving a microwave within only 3 min. • ZnO rods (average diameter of 0.3–0.5 μm, length of 1.0–1.5 μm) were grown on ACF. • 99% of tetracycline was degraded and 90.7% TOC was removed within 1 h under UV light. • ZnO rod-ACF achieved high performances even after three cycles of uses. - Abstract: New composite materials of activated carbon fiber (ACF) coated with zinc oxide (ZnO) were obtained by applying a green, cost-effective and rapid synthetic route using a commercial microwave oven. ZnO rods with a uniform and stable structure and an average diameter of 0.3–0.5 μm and length of 1.0–1.5 μm were achieved after only 3-min microwave treatment. The properties of ZnO were efficiently transferred to ACF, such that the resulting material, termed ZnO rod-ACF, demonstrated a promising potential as an efficient photocatalyst and simultaneously as an adsorbent. Pharmaceutical tetracycline at a concentration of 40 mg/L was used to evaluate the organic pollutant removal capacity of the synthesized materials. At pH 8, ZnO rod-ACF exhibited excellent removal capacity (over 99%) and mineralization (90.7%) of tetracycline in aqueous solution within 1 h under UV irradiation. The stability of ZnO rod-ACF was maintained and the mineralization of tetracycline was also maintained at 81.35% after multiple usage cycles. The photodegradation pathways of tetracycline were proposed based on the identified reaction intermediates.

  1. Enacting Culturally Relevant Pedagogy: Asset Mapping in Urban Classrooms

    Science.gov (United States)

    Borrero, Noah; Sanchez, Gabriel

    2017-01-01

    In an attempt to confront monolithic perceptions of achievement and an educational narrative that defines communities of Color by their supposed deficits, the current study presents asset mapping as an example of culturally relevant pedagogy in action. Asset mapping is a pedagogical tool for students to visually represent personalized stories of…

  2. A relevance theory of induction.

    Science.gov (United States)

    Medin, Douglas L; Coley, John D; Storms, Gert; Hayes, Brett K

    2003-09-01

    A framework theory, organized around the principle of relevance, is proposed for category-based reasoning. According to the relevance principle, people assume that premises are informative with respect to conclusions. This idea leads to the prediction that people will use causal scenarios and property reinforcement strategies in inductive reasoning. These predictions are contrasted with both existing models and normative logic. Judgments of argument strength were gathered in three different countries, and the results showed the importance of both causal scenarios and property reinforcement in category-based inferences. The relation between the relevance framework and existing models of category-based inductive reasoning is discussed in the light of these findings.

  3. Profiles of Dialogue for Relevance

    Directory of Open Access Journals (Sweden)

    Douglas Walton

    2016-12-01

    Full Text Available This paper uses argument diagrams, argumentation schemes, and some tools from formal argumentation systems developed in artificial intelligence to build a graph-theoretic model of relevance shown to be applicable (with some extensions as a practical method for helping a third party judge issues of relevance or irrelevance of an argument in real examples. Examples used to illustrate how the method works are drawn from disputes about relevance in natural language discourse, including a criminal trial and a parliamentary debate.

  4. Efficient Temporal Action Localization in Videos

    KAUST Repository

    Alwassel, Humam

    2018-04-17

    State-of-the-art temporal action detectors inefficiently search the entire video for specific actions. Despite the encouraging progress these methods achieve, it is crucial to design automated approaches that only explore parts of the video which are the most relevant to the actions being searched. To address this need, we propose the new problem of action spotting in videos, which we define as finding a specific action in a video while observing a small portion of that video. Inspired by the observation that humans are extremely efficient and accurate in spotting and finding action instances in a video, we propose Action Search, a novel Recurrent Neural Network approach that mimics the way humans spot actions. Moreover, to address the absence of data recording the behavior of human annotators, we put forward the Human Searches dataset, which compiles the search sequences employed by human annotators spotting actions in the AVA and THUMOS14 datasets. We consider temporal action localization as an application of the action spotting problem. Experiments on the THUMOS14 dataset reveal that our model is not only able to explore the video efficiently (observing on average 17.3% of the video) but it also accurately finds human activities with 30.8% mAP (0.5 tIoU), outperforming state-of-the-art methods

  5. Relevance theory and pragmatic impairment.

    Science.gov (United States)

    Leinonen, E; Kerbel, D

    1999-01-01

    This paper summarizes aspects of relevance theory that are useful for exploring impairment of pragmatic comprehension in children. It explores data from three children with pragmatic language difficulties within this framework. Relevance theory is seen to provide a means of explaining why, in a given context, a particular utterance is problematic. It thus enables one to move on from mere description of problematic behaviours towards their explanation. The theory provides a clearer delineation between the explicit and the implicit, and hence between semantics and pragmatics. This enables one to place certain difficulties more firmly within semantics and others within pragmatics. Relevance, and its maximization in communication, are squarely placed within human cognition, which suggests a close connection between pragmatic and cognitive (dis)functioning. Relevance theory thus emerges as a powerful tool in the exploration and understanding of pragmatic language difficulties in children and offers therapeutically valuable insight into the nature of interactions involving individuals with such impairments.

  6. Relevance theory: pragmatics and cognition.

    Science.gov (United States)

    Wearing, Catherine J

    2015-01-01

    Relevance Theory is a cognitively oriented theory of pragmatics, i.e., a theory of language use. It builds on the seminal work of H.P. Grice(1) to develop a pragmatic theory which is at once philosophically sensitive and empirically plausible (in both psychological and evolutionary terms). This entry reviews the central commitments and chief contributions of Relevance Theory, including its Gricean commitment to the centrality of intention-reading and inference in communication; the cognitively grounded notion of relevance which provides the mechanism for explaining pragmatic interpretation as an intention-driven, inferential process; and several key applications of the theory (lexical pragmatics, metaphor and irony, procedural meaning). Relevance Theory is an important contribution to our understanding of the pragmatics of communication. © 2014 John Wiley & Sons, Ltd.

  7. Clinical relevance in anesthesia journals

    DEFF Research Database (Denmark)

    Lauritsen, Jakob; Møller, Ann M

    2006-01-01

    The purpose of this review is to present the latest knowledge and research on the definition and distribution of clinically relevant articles in anesthesia journals. It will also discuss the importance of the chosen methodology and outcome of articles....

  8. Application of nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, UV-Visible spectroscopy and kinetic modeling for elucidation of adsorption chemistry in uptake of tetracycline by zeolite beta.

    Science.gov (United States)

    Kang, Jin; Liu, Huijuan; Zheng, Yu-Ming; Qu, Jiuhui; Chen, J Paul

    2011-02-01

    Extensive usage of tetracycline has resulted in its contamination in surface water and groundwater. The adsorption of tetracycline on zeolite beta was systematically investigated for the decontamination of the antibiotic polluted water in this study. Ninety percent of uptake by the zeolite beta occured in 0.25h, and the adsorption equilibrium was obtained within 3h, which was well described by an intraparticle diffusion model. The adsorption generally increased when pH was increased from 4.0 to 5.0, and then decreased significantly as the pH was further increased, which was caused by the pH-dependent speciation of tetracycline and surface charge of zeolite beta. Both Freundlich and Langmuir equations well described the adsorption isotherm. A thermodynamic analysis showed that the sorption process was spontaneous and endothermic. Aluminum atoms in the zeolite played a crucial role in the uptake; the adsorption increased with the increasing aluminum content in zeolite. The UV-Visible spectroscopy study showed that the spectra of tetracycline changed upon the interaction with zeolite beta, which could be ascribed to the formation of complexes of tetracycline and aluminum atoms in the zeolite surface. Nuclear magnetic resonance spectroscopy study further confirmed the participation of Al in the tetracycline adsorption. Fourier transform infrared spectroscopy studies showed that the amino functional groups in tetracycline were involved in the complexation with the zeolite surface. Copyright © 2010 Elsevier Inc. All rights reserved.

  9. Clinical relevance in anesthesia journals

    DEFF Research Database (Denmark)

    Lauritsen, Jakob; Møller, Ann M

    2006-01-01

    The purpose of this review is to present the latest knowledge and research on the definition and distribution of clinically relevant articles in anesthesia journals. It will also discuss the importance of the chosen methodology and outcome of articles.......The purpose of this review is to present the latest knowledge and research on the definition and distribution of clinically relevant articles in anesthesia journals. It will also discuss the importance of the chosen methodology and outcome of articles....

  10. Evaluation of the Charm maximum residue limit β-lactam and tetracycline test for the detection of antibiotics in ewe and goat milk.

    Science.gov (United States)

    Beltrán, M C; Romero, T; Althaus, R L; Molina, M P

    2013-05-01

    The Charm maximum residue limit β-lactam and tetracycline test (Charm MRL BLTET; Charm Sciences Inc., Lawrence, MA) is an immunoreceptor assay utilizing Rapid One-Step Assay lateral flow technology that detects β-lactam or tetracycline drugs in raw commingled cow milk at or below European Union maximum residue levels (EU-MRL). The Charm MRL BLTET test procedure was recently modified (dilution in buffer and longer incubation) by the manufacturers to be used with raw ewe and goat milk. To assess the Charm MRL BLTET test for the detection of β-lactams and tetracyclines in milk of small ruminants, an evaluation study was performed at Instituto de Ciencia y Tecnologia Animal of Universitat Politècnica de València (Spain). The test specificity and detection capability (CCβ) were studied following Commission Decision 2002/657/EC. Specificity results obtained in this study were optimal for individual milk free of antimicrobials from ewes (99.2% for β-lactams and 100% for tetracyclines) and goats (97.9% for β-lactams and 100% for tetracyclines) along the entire lactation period regardless of whether the results were visually or instrumentally interpreted. Moreover, no positive results were obtained when a relatively high concentration of different substances belonging to antimicrobial families other than β-lactams and tetracyclines were present in ewe and goat milk. For both types of milk, the CCβ calculated was lower or equal to EU-MRL for amoxicillin (4 µg/kg), ampicillin (4 µg/kg), benzylpenicillin (≤ 2 µg/kg), dicloxacillin (30 µg/kg), oxacillin (30 µg/kg), cefacetrile (≤ 63 µg/kg), cefalonium (≤ 10 µg/kg), cefapirin (≤ 30 µg/kg), desacetylcefapirin (≤ 30 µg/kg), cefazolin (≤ 25 µg/kg), cefoperazone (≤ 25 µg/kg), cefquinome (20 µg/kg), ceftiofur (≤ 50 µg/kg), desfuroylceftiofur (≤ 50µg/kg), and cephalexin (≤ 50 µg/kg). However, this test could neither detect cloxacillin nor nafcillin at or below EU-MRL (CCβ >30 µg/kg). The

  11. Significant NRC Enforcement Actions

    Data.gov (United States)

    Nuclear Regulatory Commission — This dataset provides a list of Nuclear Regulartory Commission (NRC) issued significant enforcement actions. These actions, referred to as "escalated", are issued by...

  12. Controlled-release of tetracycline and lovastatin by poly(D,L-lactide-co-glycolide acid-chitosan nanoparticles enhances periodontal regeneration in dogs

    Directory of Open Access Journals (Sweden)

    Lee BS

    2016-01-01

    Full Text Available Bor-Shiunn Lee,1 Chien-Chen Lee,2 Yi-Ping Wang,2 Hsiao-Jan Chen,3 Chern-Hsiung Lai,4 Wan-Ling Hsieh,1 Yi-Wen Chen2 1Graduate Institute of Oral Biology, 2Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University and National Taiwan University Hospital, 3Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, 4College of Life Science, Kaohsiung Medical University, Kaohsiung, Taiwan Abstract: Chronic periodontitis is characterized by inflammation of periodontal tissues, leading to bone resorption and tooth loss. The goal of treatment is to regenerate periodontal tissues including bone and cementum lost as a consequence of disease. The local delivery of tetracycline was proven to be effective in controlling localized periodontal infection without apparent side effects. Previous studies suggested that lovastatin has a significant role in new bone formation; however, the local delivery of lovastatin might enhance its therapeutic effects. A number of local delivery devices have been developed recently, including poly(D,L-lactide-co-glycolide acid (PLGA nanoparticles. The aim of this study was to develop a local delivery device, PLGA-lovastatin-chitosan-tetracycline nanoparticles, which allows the sequential release of tetracycline and lovastatin to effectively control local infection and promote bone regeneration in periodontitis. The size and microstructure of nanoparticles were examined by transmission electron microscopy, Nanoparticle Size Analyzer, and Fourier transform infrared spectroscopy. The release of tetracycline and lovastatin was quantified using a UV-Vis spectrophotometer. Furthermore, the cytotoxic effect and alkaline phosphatase activity of the nanoparticles in osteoblast cell cultures as well as antibacterial activity against periodontal pathogens were investigated. Finally, the bone regeneration potential of PLGA nanoparticles in

  13. Behavioral and socioeconomic risk factors associated with probable resistance to ceftriaxone and resistance to penicillin and tetracycline in Neisseria gonorrhoeae in Shanghai.

    Directory of Open Access Journals (Sweden)

    Molly A Trecker

    Full Text Available Globally, incidence of Neisseria gonorrhoeae infection is once again the highest of the bacterial sexually transmitted infections. The bacterium can produce serious complications in those infected, and emerging resistance to third generation cephalosporins could usher in an era of potentially untreatable gonorrhea. This research aimed to identify risk factors for antibiotic resistant gonorrhea infection among clients at a Shanghai sexually transmitted infection clinic over two time periods, 2004-2005 and 2008-2011. Demographic and risk factor behavior data, and biological samples for antimicrobial resistance analysis, were collected. Statistical models were built to identify risk factors associated with probable resistance to ceftriaxone and resistance to penicillin and tetracycline. High levels of ciprofloxacin resistance (98% in our sample precluded examining its risk factors; all isolates were susceptible to spectinomycin. Overall (P<0.001, chromosomal (P<0.001, and plasmid-mediated (P = 0.01 penicillin resistance decreased from the first to second period of the study. For tetracycline, chromosomal resistance decreased (P = 0.01 and plasmid-mediated resistance increased (P<0.001 between the first and second periods of study. In multi-level multivariable regression models, male gender (P = 0.03 and older age (P = 0.01 were associated with increased minimum inhibitory concentrations to ceftriaxone. Male gender (P = 0.03 and alcohol use (P = 0.02 were associated with increased odds of overall tetracycline resistance. Male gender was associated with increased odds of chromosomally-mediated tetracycline resistance (P = 0.04, and alcohol use was associated with increased odds of plasmid-mediated tetracycline resistance (P = 0.02. Additionally, individuals in middle-salary categories were found to have lower odds of plasmid-mediated resistance to tetracycline compared with those in the lowest salary category (P≤0

  14. Seasonal dynamics of tetracycline resistance gene transport in the Sumas River agricultural watershed of British Columbia, Canada.

    Science.gov (United States)

    Keen, Patricia L; Knapp, Charles W; Hall, Kenneth J; Graham, David W

    2018-07-01

    Environmental transport of contaminants that can influence the development of antibiotic resistance in bacteria is an important concern in the management of ecological and human health risks. Agricultural regions are locales where practices linked to food crop and livestock production can introduce contaminants that could alter the selective pressures for the development of antibiotic resistance in microbiota. This is important in regions where the use of animal manure or municipal biosolids as waste and/or fertilizer could influence selection for antibiotic resistance in pathogenic bacterial species. To investigate the environmental transport of contaminants that could lead to the development of antibiotic resistance in bacteria, a watershed with one of the highest levels of intensity of agricultural activity in Canada was studied; the Sumas River located 60 km east of Vancouver, British Columbia. This two-year assessment monitored four selected tetracycline resistance genes (tet(O), tet(M), tet(Q), tet(W)) and water quality parameters (temperature, specific conductivity, turbidity, suspended solids, nitrate, phosphate and chloride) at eight locations across the watershed. The tetracycline resistance genes (Tc r ) abundances in the Sumas River network ranged between 1.47 × 10 2 and 3.49 × 10 4  copies/mL and ranged between 2.3 and 6.9 copies/mL in a control stream (located far from agricultural activities) for the duration of the study. Further, Tc r abundances that were detected in the wet season months ranged between 1.3 × 10 3 and 2.29 × 10 4  copies/mL compared with dry season months (ranging between 0.6 and 31.2 copies/mL). Highest transport rates between 1.67 × 10 11 and 1.16 × 10 12  copies/s were observed in November 2005 during periods of high rainfall. The study showed that elevated concentrations of antibiotic resistance genes in the order of 10 2 -10 4  copies/mL can move through stream networks in an

  15. Detection and Diversity evaluation of tetracycline resistance genes in grassland-based production systems in Colombia, South America

    Directory of Open Access Journals (Sweden)

    Johanna eSantamaría

    2011-12-01

    Full Text Available Grassland-based production systems use approximately 26 percent of land surface on earth. However, there are no evaluations of these systems as a source of antibiotic pollution. This study was conducted to evaluate the presence, diversity, and distribution of tetracycline resistance genes in the grasslands of the Colombian Andes, where administration of antibiotics to animals is limited to treat disease and growth promoters are not included in animals’ diet. Animal (ruminal fluid and feces and environmental (soil and water samples were collected from six different dairy cattle farms and evaluated by PCR for the genes encoding ribosomal protection proteins (RPPs tet(M, tet(O, tetB(P, tet(Q tet(W, tet(S, tet(T, tet(A, and tetracycline efflux pumps tet(A, tet(B, tet(D, tet(H, tet(J, tet(Z, and tet(D. A wide distribution and high frequency for genes tet(W and tet(Q were found in both sample types. Other genes encoding RPPs ( tetB(P, tet(O, tet(M, tet(S and tet(T were detected at lower frequencies and more restricted distributions. Genes encoding efflux pumps were not common in this region, and only two of them, tet(B and tet(Z, were detected. DGGE-PCR followed by comparative sequence analysis of tet(W and tet(Q showed that the sequences detected in animals did not differ from those coming from soil and water, suggesting the transmission of tet genes from animal reservoirs to the environment. Additionally, there seems to be a differential flow of tet genes from one reservoir to the other because gene tet(O and tetB(P, detected in high frequencies in feces, were detected in low frequencies or not detected at all in the environment. Finally, the farms sampled in this study showed more than 50% similarity in relation to the tet genes detected and their frequencies. However, farms closer in space and under the influence of the same hydrographic network were significantly more similar to each other.

  16. Glass substrates crosslinked with tetracycline-imprinted polymeric silicate and CdTe quantum dots as fluorescent sensors

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Mu-Rong [Department of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Hu, Chiung-Wen [Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Chen, Jian-Lian, E-mail: cjl@mail.cmu.edu.tw [School of Pharmacy, China Medical University, No. 91 Hsueh-Shih Road, Taichung 40402, Taiwan (China)

    2016-06-21

    A fluorescence-based sensor that combines the merits of quantum dots (QDs) and molecularly imprinted polymers (MIPs) was first fabricated on a glass substrate via a sol–gel route. Some of the key performance factors, including silane selection, substrate etching, the reaction times of glass silanization and sol–gel polymerization, and the times and methods used for template stripping and loading, were discussed and determined. After fabricating the sensor on either a 3-aminopropyltriethoxysilane (APS) or a 3-mercaptopropyltriethoxysilane (MPS) modified glass substrate, APS showed a much better performance than MPS as both the capping reagent of QDs and the functional monomer of tetracycline-templated MIPs. The APS-QDs on APS-modified glass had a higher imprinted factor (IF = 5.6), a lower LOD (2.1 μM, 3σ), and a more stable signal (2.8%, n = 10 at 70 μM) than those on the MPS-modified glass (IF = 5.2, LOD = 6.5 μM, stability = 6.2%). Furthermore, the recoveries of tetracycline (70 μM) from BSA (133 μg/mL) and FBS (0.66 ppt) by the APS-modified glass were 98% (RSD = 3.5%, n = 5) and 97% (RSD = 5.7%), respectively. For the MPS-modified glass, recoveries of 95% (RSD = 7.2%) and 89% (RSD = 8.7%) were observed at 67 μg/mL of BSA and 0.33 ppt of FBS, respectively. - Highlights: • QD-MIP composites were first built on a glass substrate through a sol–gel route. • Two silanes were evaluated as both a surface modifier and a functional capping monomer. • Fluorescence enhancement by template on glass was different from quenching in solution.

  17. Hybrid Action Systems

    DEFF Research Database (Denmark)

    Rönnkö, M.; Ravn, Anders Peter; Sere, K.

    2003-01-01

    In this paper we investigate the use of action systems with differential actions in the specifcation of hybrid systems. As the main contribution we generalize the definition of a differential action, allowing the use of arbitrary relations over model variables and their time-derivatives in modell......In this paper we investigate the use of action systems with differential actions in the specifcation of hybrid systems. As the main contribution we generalize the definition of a differential action, allowing the use of arbitrary relations over model variables and their time...... to the differential action, thus, allowing stepwise development of hybrid systems Udgivelsesdato: JAN 1...

  18. Prevalence of tetracycline resistance and genotypic analysis of populations of Escherichia coli from animals, carcasses and cuts processed at a pig slaughterhouse

    DEFF Research Database (Denmark)

    Shuyu, Wu; Dalsgaard, Anders; Vieira, Antonio R

    2009-01-01

    A Danish pig slaughterhouse was visited in this study to investigate the impact of carcass processing on prevalence of tetracycline-resistant Escherichia coli, and to identify the origins of carcass contaminations with E. coli by assessing genetic diversity of E. coli populations on carcasses...... carcasses (87%) were contaminated with E. coli that were also isolated from faeces of either the same or other pigs slaughtered on the same day; and 80% of stunned carcasses shared the same E. coli PFGE subtypes. The results suggest that some carcass processing steps in the slaughterhouse were effective...... in reducing both E. coli numbers and the tetracycline resistance prevalence in E. coli on carcasses. Faeces from the same or other pigs slaughtered on the same day were likely to be an important source of E. coli carcass contamination. Combined data from E. coli enumeration, PFGE typing and antimicrobial...

  19. Screening for tetracycline residues in food products of animal origin in the State of Kuwait using Charm II radio-immunoassay and LC/MS/MS methods.

    Science.gov (United States)

    Al-Mazeedi, Hani M; Abbas, Alaa B; Alomirah, Hussam F; Al-Jouhar, Wafaa Y; Al-Mufty, Siham A; Ezzelregal, Mohamed M; Al-Owaish, Rashed A

    2010-03-01

    This study surveyed tetracycline residues in foods marketed in Kuwait using various techniques to determine their prevalence above the threshold level. A total of 1517 locally produced and imported food samples of animal origin were collected for analyses, comprising dairy products, eggs and tissue samples (meat, poultry and fish) to give a representative picture of the current use and/or misuse of the drug in Kuwait. Screening was carried out using the Charm II test for tetracycline residues. Positive and suspect positive samples were confirmed by LC/MS/MS. Negative and positive controls, in triplicate, were applied to each method and showed 80-100% agreement. The results showed that 100% of tested eggs, meat, fish, ice cream and cheese were within the limit, while 5% of poultry and 18% of milk samples were above the permitted limit.

  20. [Evaluation of the Epsilometer (Etest) method for the detection of tetracycline susceptibility in Paenibacillus larvae, the causal agent of American foulbrood disease of honeybees].

    Science.gov (United States)

    Alippi, Adriana M; Reynaldi, Francisco J; López, Ana C

    2013-01-01

    American foulbrood (AFB) is a bacterial disease caused by the spore-forming, grampositive bacterium Paenibacillus larvae, which affects honeybee broods worldwide. The aim of this work was to compare the Epsilometer test (Etest) to the agar dilution method for testing a collection of 22 P. larvae strains to tetracycline by using MYPGP and Iso- Sensitest agars. Results showed that a categorical agreement of 100% was found when using Iso-Sensitest, while a categorical agreement of 86.36% was found (with 3 minor errors) when MYPGP was tested. In conclusion, the Etest could be a rapid and reliable method for testing MIC values of tetracycline in P. larvae only when used in combination with Iso-Sensitest agar. Nevertheless, these results should be confirmed with future studies involving a larger number of isolates. Copyright © 2013 Asociación Argentina de Microbiología. Publicado por Elsevier España. All rights reserved.

  1. Incidence, distribution, and spread of tetracycline resistance determinants and integron-associated antibiotic resistance genes among motile aeromonads from a fish farming environment

    DEFF Research Database (Denmark)

    Schmidt, Anja S.; Bruun, Morten Sichlau; Dalsgaard, Inger

    2001-01-01

    isolates). In addition, 23 isolates had "empty" integrons without inserted gene cassettes. As far as OTC resistance was concerned, only 66 (30%) out of 216 resistant aeromonads could be assigned to resistance determinant class A (19 isolates), D (n = 6), or E (n = 39); three isolates contained two...... tetracycline resistance determinants (AD, AE, and DE). Forty OTC-resistant isolates containing large plasmids were selected as donors in a conjugation assay, 27 of which also contained a class I integron. Out of 17 successful R- plasmid transfers to Escherichia coli recipients, the respective integrons were...... cotransferred along with the tetracycline resistance determinants in 15 matings. Transconjugants were predominantly tetA positive (10 of 17) and contained class I integrons with two or more inserted antibiotic resistance genes. While there appeared to be a positive correlation between conjugative R...

  2. Solr in action

    CERN Document Server

    Grainger, Trey

    2014-01-01

    Whether handling big data, building cloud-based services, or developing multi-tenant web applications, it's vital to have a fast, reliable search solution. Apache Solr is a scalable and ready-to-deploy open-source full-text search engine powered by Lucene. It offers key features like multi-lingual keyword searching, faceted search, intelligent matching, and relevancy weighting right out of the box. Solr in Action is the definitive guide to implementing fast and scalable search using Apache Solr 4. It uses well-documented examples ranging from basic keyword searching to scaling a system for billions of documents and queries. Readers will gain a deep understanding of how to implement core Solr capabilities such as faceted navigation through search results, matched snippet highlighting, field collapsing and search results grouping, spell checking, query auto-complete, querying by functions, and more. RETAIL SELLING POINTS Clearly-written comprehensive guide In-depth coverage of Solr 4 Uses real-world examples ba...

  3. Hybrid Action Systems

    DEFF Research Database (Denmark)

    Ronkko, Mauno; Ravn, Anders P.

    1997-01-01

    a differential action, which allows differential equations as primitive actions. The extension allows us to model hybrid systems with both continuous and discrete behaviour. The main result of this paper is an extension of such a hybrid action system with parallel composition. The extension does not change...... the original meaning of the parallel composition, and therefore also the ordinary action systems can be composed in parallel with the hybrid action systems....

  4. 3H-tetracycline as a proxy for 41Ca for measuring dietary perturbations of bone resorption

    International Nuclear Information System (INIS)

    Weaver, Connie; Cheong, Jennifer; Jackson, George; Elmore, David; McCabe, George; Martin, Berdine

    2007-01-01

    Our group is interested in evaluating early effects of dietary interventions on bone loss. Postmenopausal women lose bone following reduction in estrogen which leads to increased risk of fracture. Traditional means of monitoring bone loss and effectiveness of treatments include changes in bone density, which takes 6 months to years to observe effects, and changes in biochemical markers of bone turnover, which are highly variable and lack specificity. Prelabeling bone with 41 Ca and measuring urinary 41 Ca excretion with accelerator mass spectrometry provides a sensitive, specific, and rapid approach to evaluating effectiveness of treatment. To better understand 41 Ca technology as a tool for measuring effective treatments on reducing bone resorption, we perturbed bone resorption by manipulating dietary calcium in rats. We used 3 H-tetracycline ( 3 H-TC) as a proxy for 41 Ca and found that a single dose is feasible to study bone resorption. Suppression of bone resorption, as measured by urinary 3 H-TC, by dietary calcium was observed in rats stabilized after ovariectomy, but not in recently ovariectomized rats

  5. A comparative study of interaction of tetracycline with several proteins using time resolved anisotropy, phosphorescence, docking and FRET.

    Directory of Open Access Journals (Sweden)

    Manini Mukherjee

    Full Text Available A comparative study of the interaction of an antibiotic Tetracycline hydrochloride (TC with two albumins, Human serum albumin (HSA and Bovine serum albumin (BSA along with Escherichia Coli Alkaline Phosphatase (AP has been presented exploiting the enhanced emission and anisotropy of the bound drug. The association constant at 298 K is found to be two orders of magnitude lower in BSA/HSA compared to that in AP with number of binding site being one in each case. Fluorescence resonance energy transfer (FRET and molecular docking studies have been employed for the systems containing HSA and BSA to find out the particular tryptophan (Trp residue and the other residues in the proteins involved in the binding process. Rotational correlation time (θc of the bound TC obtained from time resolved anisotropy of TC in all the protein-TC complexes has been compared to understand the binding mechanism. Low temperature (77 K phosphorescence (LTP spectra of Trp residues in the free proteins (HSA/BSA and in the complexes of HSA/BSA have been used to specify the role of Trp residues in FRET and in the binding process. The results have been compared with those obtained for the complex of AP with TC. The photophysical behaviour (viz., emission maximum, quantum yield, lifetime and θc of TC in various protic and aprotic polar solvents has been determined to address the nature of the microenvironment of TC in the protein-drug complexes.

  6. Removal of tetracycline from aqueous solutions using polyvinylpyrrolidone (PVP-K30) modified nanoscale zero valent iron

    International Nuclear Information System (INIS)

    Chen Hua; Luo Hanjin; Lan Yuecun; Dong Tingting; Hu Bingjie; Wang Yiping

    2011-01-01

    The interactions of tetracycline (TC) with nanoscale zerovalent iron (NZVI) modified by polyvinylpyrrolidone (PVP-K30) were investigated using batch experiments as a function of reactant concentration, pH, temperature, and competitive anions. Transmission electron micrographs (TEM), BET surface area and Zeta (ζ)-potential analyses indicated that the mean particle size was 10-40 nm with a surface area of 36.90 m 2 /g, and a iso-electric point of PVP-NZVI was 7.2. The results of X-ray diffraction (XRD) and high-resolution X-ray photoelectron spectroscopy (HR-XPS) of modified nanoscale zerovalent iron (PVP-NZVI) revealed that the iron nanoparticles likely have a core of zero-valent iron (Fe 0 ), while a shell is largely made of iron oxides. Degradation of TC was strongly dependent on pH and temperature. The presence of silicate and phosphate strongly inhibited the removal of TC, whereas acetate and sulfate only caused slight inhibition. LC-MS analysis of the treated solution showed that the degradation products from TC resulted from the removal of functional groups from the TC ring. The degradation products were detected both in the treated solution (initial pH of 3.0 and 6.5) and on the surface of PVP-NZVI after 4-h interaction, indicating that PVP-NZVI can adsorb both TC and its degradation products.

  7. Interaction of residue tetracycline hydrochloride in milk with β-galactosidase protein by multi-spectrum methods and molecular docking

    Science.gov (United States)

    Gao, Xin; Bi, Hongna; Zuo, Huijun; Jia, Jingjing; Tang, Lin

    2017-08-01

    The purpose of this study was to explore the effect of residue tetracycline hydrochloride (TCH) in milk on molecular structure and activity of β-Gal. Inhibition kinetics assay showed the TCH inhibited β-Gal activity reversibly in a competitive manner. In addition, differences in the activity of β-Gal in the absence and presence of TCH as a function of pH and temperature were found although the optimum pH and temperature of β-Gal remained similar. Fluorescence experiment results showed that TCH effectively quenched the intrinsic fluorescence of β-Gal via static quenching. Thermodynamic parameters delineated the major roles of electrostatic forces played between β-Gal and TCH. Additionally, synchronous fluorescence and circular dichroism spectra (CD spectra) results indicated the secondary structure of β-Gal was changed due to the formation of β-Gal-TCH complexes. The molecular docking further revealed that TCH interacted with some amino acid residues of β-Gal, affecting the active site of the enzyme and thus leading to change in enzyme activity. These alterations in conformation and activity of β-Gal should be taken into consideration while using β-Gal for producing oligosaccharide prebiotics on dairy industries.

  8. Dynamics of copper and tetracyclines during composting of water hyacinth biomass amended with peat or pig manure.

    Science.gov (United States)

    Lu, Xin; Liu, Lizhu; Fan, Ruqin; Luo, Jia; Yan, Shaohua; Rengel, Zed; Zhang, Zhenhua

    2017-10-01

    Composting is one of the post-treatment methods for phytoremediation plants. Due to a high potential of water hyacinth to accumulate pollutants, the physicochemical parameters, microbial activity as well as fates of copper (Cu) and tetracyclines (TCs) were investigated for the different amended water hyacinth biomass harvested from intensive livestock and poultry wastewater, including unamended water hyacinth (W), water hyacinth amended with peat (WP), and water hyacinth amended with pig manure (WPM) during the composting process. Pig manure application accelerated the composting process as evidenced by an increase of temperature, electrical conductivity (EC), NH 4 -N, as well as functional diversity of microbial communities compared to W and WP treatments. Composting process was slowed down by high Cu, but not by TCs. The addition of peat significantly increased the residual fraction of Cu, while pig manure addition increased available Cu concentration in the final compost. Cu could be effectively transformed into low available (oxidizable) and residual fractions after fermentation. In contrast, less than 0.5% of initial concentrations of TCs were determined at the end of 60-day composting for all treatments in the final composts. The dissipation of TCs was accelerated by the high Cu concentration during composting. Therefore, composting is an effective method for the post-treatment and resource utilization of phytoremediation plants containing Cu and/or TCs.

  9. Comparison of ozone and thermal hydrolysis combined with anaerobic digestion for municipal and pharmaceutical waste sludge with tetracycline resistance genes.

    Science.gov (United States)

    Pei, Jin; Yao, Hong; Wang, Hui; Ren, Jia; Yu, Xiaohua

    2016-08-01

    Biosolids from wastewater treatment plant (WWTP) are environmental reservoirs of antibiotic resistance genes, which attract great concerns on their efficient treatments. Anaerobic digestion (AD) is widely used for sewage sludge treatment but its effectiveness is limited due to the slow hydrolysis. Ozone and thermal hydrolysis pre-treatment were employed to improve AD efficiency and reduce antibiotic-resistant genes in municipal and pharmaceutical waste sludge (MWS and PWS, respectively) in this study. Sludge solubilization achieved 15.75-25.09% and 14.85-33.92% after ozone and thermal hydrolysis, respectively. Both pre-treatments improved cumulative methane production and the enhancements were greater on PWS than MWS. Five tetracycline-resistant genes (tet(A), tet(G), tet(Q), tet(W), tet(X)) and one mobile element (intI1) were qPCR to assess pre-treatments. AD of pre-treated sludge reduced more tet genes than raw sludge for both ozonation and thermal hydrolysis in PWS and MWS. Thermal hydrolysis pre-treatment was more efficient than ozone for reduction after AD. Results of this study help support management options for reducing the spread of antibiotic resistance from biosolids. Copyright © 2016. Published by Elsevier Ltd.

  10. Activity of translation system and abundance of tmRNA during development of Streptomyces aureofaciens producing tetracycline.

    Science.gov (United States)

    Palecková, P; Bobek, J; Felsberg, J; Mikulík, K

    2006-01-01

    Transition from exponential phase of growth to stationary phase in Streptomyces aureofaciens is characterized by a decrease in the rate of translation and induction of tetracycline (Ttc) biosynthesis. In exponential phase, no significant changes were found in the activity of ribosomes at binding of ternary complex Phe-tRNA.EF-Tu.GTP to the A-site on ribosomes. Overexpression of Ttc in stationary phase is accompanied by a decrease in the binding of the ternary complex Phe-tRNA.EF-Tu.GTP to the A-site of ribosome and a formation of an aggregate with Ttc by part of the ribosomes. Antibiotics that cause ribosome to stall or pause could increase the requirement for tmRNA in the process called trans-translation. We found differences in the level of tmRNA during the development of S. aureofaciens. Subinhibitory concentrations of Ttc, streptomycin and chloramphenicol induced an increase in the tmRNA level in cells from the exponential phase of growth. In vitro trans-translation system of S. aureofaciens was sensitive to Ttc at a concentration of > 15 micromol/L; the trans-translation system can thus be considered to contribute to resistance against Ttc produced only at sublethal concentrations. These experiments suggest that the main role of the rising tmRNA level at the beginning of the Ttc production is connected with ribosome rescue.

  11. Fluorescence Based Turn-on Probe for the Determination of Caffeine Using Europium-Tetracycline as Energy Transfer Complex.

    Science.gov (United States)

    Nanjundaiah, Shwetha; Krishna, Honnur; Bhatt, Praveena

    2016-05-01

    The study describes a simple and sensitive fluorometric sensor based on the enhancement of fluorescence intensity of Europium ion (Eu(3+)) - tetracycline (TC) charge transfer complex on addition of caffeine. The Eu(3+)-TC ternary complex has a characteristic emission peak at 615 nm (λex = 375 nm), the intensity of which increases with increase in concentration of caffeine. The caffeine sensor assay was found to be linear in the range of 0.0515 mM to 51.5 mM. The limit of detection and quantification were found to be 0.0515 mM and 0.382 mM, respectively. A caffeine recovery of 90 to 110 % in biological samples (serum and urine) indicated minimal interference by commonly present excipients in the samples. Rosenthal plots to calculate the binding capacity of caffeine with the Eu(3+)- TC complex revealed an association constant (K) of 238 x 10(3) L/mol and binding number (N) of 1.9. Bland-Altman plot comparing the developed assay and HPLC showed good agreement between values obtained by both the methods. The proposed fluorescent chemical sensor is a rapid and convenient method to determine caffeine with excellent recovery and low detection limit. The probable reaction mechanism for the formation of the turn on fluorescent probe enhancer is discussed.

  12. Changes in tetracycline partitioning and bacteria/phage-comediated ARGs in microplastic-contaminated greenhouse soil facilitated by sophorolipid.

    Science.gov (United States)

    Sun, Mingming; Ye, Mao; Jiao, Wentao; Feng, Yanfang; Yu, Pingfeng; Liu, Manqiang; Jiao, Jiaguo; He, Xiaojia; Liu, Kuan; Zhao, Yuanchao; Wu, Jun; Jiang, Xin; Hu, Feng

    2018-03-05

    The emerging mixed contamination of antibiotics and microplastics in greenhouse soil has made the control of antibiotic resistant gene (ARG) transmission a novel challenge. In this work, surfactant sophorolipid was applied to enhance the dissipation of tetracycline (TC) and tet genes in the presence of microplastics in greenhouse soil. During 49days of incubation, soil bacteria and phages were both found to be the crucial reservoirs of ARGs. Meanwhile, microplastic's presence significantly inhibited the dissipation of TC and ARGs in the soil. However, sophorolipid application was proved to outweigh the negative impact caused by microplastic existence, and lead to the highest dissipation of soil TC and ARGs. Significant positive correlation was detected between the dissipation rate of water-soluble and exchangeable TC content and bacteria/phage co-mediated ARG levels. This also held true between the two fractions of soil TC and the ratio of ARG level in the bacteria to that in the phages (B ARGs /P ARGs ). The opposite impacts of microplastic presence and sophorolipid amendment on the TC/ARG dissipation found in this work provides new information for understanding ARG transmission between bacteria and phages in the mixed contaminated greenhouse soil. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Application of molecularly imprinted polymer based matrix solid phase dispersion for determination of fluoroquinolones, tetracyclines and sulfonamides in meat.

    Science.gov (United States)

    Wang, Geng Nan; Zhang, Lei; Song, Yi Ping; Liu, Ju Xiang; Wang, Jian Ping

    2017-10-15

    In this study, a type of novel mixed-template molecularly imprinted polymer was synthesized that was able to recognize 8 fluoroquinolones, 8 sulfonamides and 4 tetracyclines simultaneously with recoveries higher than 92%. Then the polymer was used to develop a matrix solid phase dispersion method for simultaneous extraction of the 20 drugs in pork followed by determination with ultra performance liquid chromatography. During the experiments, the MMIP amount, washing solvent and elution solvent were optimized respectively. The limits of detection of this method for the 20 drugs in pork were in the range of 0.5-3.0ngg -1 , and the intra-day and inter-day recoveries from the fortified blank samples were in the range of 74.5%-102.7%. Therefore, this method could be used as a rapid, simple, specific and sensitive method for multi-determination of the residues of the three classes of drugs in meat. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Prevalence and Antibiotic Resistance against Tetracycline in Campylobacter jejuni and C. coli in Cattle and Beef Meat from Selangor, Malaysia

    Science.gov (United States)

    Premarathne, Jayasekara M. K. J. K.; Anuar, Aimi S.; Thung, Tze Young; Satharasinghe, Dilan A.; Jambari, Nuzul Noorahya; Abdul-Mutalib, Noor-Azira; Huat, John Tang Yew; Basri, Dayang F.; Rukayadi, Yaya; Nakaguchi, Yoshitsugu; Nishibuchi, Mitsuaki; Radu, Son

    2017-01-01

    Campylobacter is a major foodborne pathogen frequently associated with human bacterial gastroenteritis in the world. This study was conducted to determine the prevalence and antibiotic resistance of Campylobacter spp. in the beef food system in Malaysia. A total of 340 samples consisting of cattle feces (n = 100), beef (n = 120) from wet markets and beef (n = 120) from hypermarkets were analyzed for Campylobacter spp. The overall prevalence of Campylobacter was 17.4%, consisting of 33% in cattle fecal samples, 14.2% in raw beef from wet market and 7.5% in raw beef from the hypermarket. The multiplex-polymerase chain reaction (PCR) identified 55% of the strains as C. jejuni, 26% as C. coli, and 19% as other Campylobacter spp. A high percentage of Campylobacter spp. were resistant to tetracycline (76.9%) and ampicillin (69.2%), whilst low resistance was exhibited to chloramphenicol (7.6%). The MAR Index of Campylobacter isolates from this study ranged from 0.09 to 0.73. The present study indicates the potential public health risk associated with the beef food system, hence stringent surveillance, regulatory measures, and appropriate interventions are required to minimize Campylobacter contamination and prudent antibiotic usage that can ensure consumer safety. PMID:29255448

  15. Prevalence and Antibiotic Resistance against Tetracycline in Campylobacter jejuni and C. coli in Cattle and Beef Meat from Selangor, Malaysia

    Directory of Open Access Journals (Sweden)

    Jayasekara M. K. J. K. Premarathne

    2017-12-01

    Full Text Available Campylobacter is a major foodborne pathogen frequently associated with human bacterial gastroenteritis in the world. This study was conducted to determine the prevalence and antibiotic resistance of Campylobacter spp. in the beef food system in Malaysia. A total of 340 samples consisting of cattle feces (n = 100, beef (n = 120 from wet markets and beef (n = 120 from hypermarkets were analyzed for Campylobacter spp. The overall prevalence of Campylobacter was 17.4%, consisting of 33% in cattle fecal samples, 14.2% in raw beef from wet market and 7.5% in raw beef from the hypermarket. The multiplex-polymerase chain reaction (PCR identified 55% of the strains as C. jejuni, 26% as C. coli, and 19% as other Campylobacter spp. A high percentage of Campylobacter spp. were resistant to tetracycline (76.9% and ampicillin (69.2%, whilst low resistance was exhibited to chloramphenicol (7.6%. The MAR Index of Campylobacter isolates from this study ranged from 0.09 to 0.73. The present study indicates the potential public health risk associated with the beef food system, hence stringent surveillance, regulatory measures, and appropriate interventions are required to minimize Campylobacter contamination and prudent antibiotic usage that can ensure consumer safety.

  16. Adsorption of tetracycline on soil and sediment: Effects of pH and the presence of Cu(II)

    International Nuclear Information System (INIS)

    Zhang Zheyun; Sun Ke; Gao Bo; Zhang Guixiang; Liu Xitao; Zhao Ye

    2011-01-01

    Tetracycline (TC) is frequently detected in the environment, however, knowledge on the environmental fate and transport of TC is still limited. Batch adsorption experiments of TC by soil and sediment samples were conducted. The distribution of charge and electrostatic potential of individual atoms of various TC species in the aqueous solution were determined using MOPAC version 0.034 W program in ChemBio3D Ultra software. Most of the adsorption isotherms on the soil, river and marine sediments were well fitted with the Freundlich and Polanyi-Manes (PMM) models. The single point organic carbon (OC)-normalized adsorption distribution coefficients (K OC ) and PMM saturated adsorption capacity (Q OC 0 ) values of TC were associated with the mesopore volume and clay content to a greater extent, indicating the mesopore volume of the soil and sediments and their clay content possibly influenced the fate and transport of TC in the natural environment. The adsorption of TC on soil and sediments strongly depended on the pH and presence of Cu(II). The presence of Cu(II) facilitated TC adsorption on soil and sediments at low pH (pH < 5), possibly due to the metallic complexation and surface-bridging mechanism by Cu(II) adsorption on soil and sediments. The cation exchange interaction, metallic complexation and Coulombic interaction of mechanisms for adsorption of TC to soils and sediments were further supported by quantum chemical calculation of various TC species in different pH.

  17. Real-time PCR methods for quantitative monitoring of streptomycin and tetracycline resistance genes in agricultural ecosystems.

    Science.gov (United States)

    Walsh, F; Ingenfeld, A; Zampicolli, M; Hilber-Bodmer, M; Frey, J E; Duffy, B

    2011-08-01

    Antibiotic application in plant agriculture is primarily used to control fire blight caused by Erwinia amylovora in pome fruit orchards. In order to facilitate environmental impact assessment for antibiotic applications, we developed and validated culture-independent quantitative real-time PCR multiplex assays for streptomycin (strA, strB, aadA and insertion sequence IS1133) and tetracycline (tetB, tetM and tetW) resistance elements in plant and soil samples. The qPCR were reproducible and consistent whether the DNA was extracted directly from bacteria, plant and soil samples inoculated with bacteria or soil samples prior to and after manure slurry treatment. The genes most frequently identified in soils pre- and post-slurry treatment were strB, aadA, tetB and tetM. All genes tested were detected in soils pre-slurry treatment, and a decrease in relative concentrations of tetB and the streptomycin resistance genes was observed in samples taken post-slurry treatment. These multiplex qPCR assays offer a cost-effective, reliable method for simultaneous quantification of antibiotic resistance genes in complex, environmental sample matrices. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Hungarian climate change action plan

    Energy Technology Data Exchange (ETDEWEB)

    Molnar, S.; Takacs, T. [Systemexpert Consulting Ltd., Budapest (Hungary); Arpasi, M. [MOL, Budapest (Hungary); Farago, T.; Palvoelgyi, T. [Ministry for Environment and Regional Policy, Budapest (Hungary); Harnos, Z. [Univ. of Horticulture, Budapest (Hungary); Lontay, Z. [EGI-Contracting Engineering Co. Ltd., Budapest (Hungary); Somogyi, Z. [Forest Research Inst., Budapest (Hungary); Tajthy, T. [Univ. of Technology, Budapest (Hungary)

    1998-12-31

    In 1994--1996, within the framework of the US Country Studies Program, the Hungarian Country Study Team developed the national greenhouse gas emission inventory, and elaborated the mitigation options for the different sectors of the economy. In 1997, the development of a National Action Plan was begun as the continuation of this work. Results of the inventory study showed that greenhouse gas emissions decreased from the selected base level (i.e., from the yearly average emissions of 1985--1987) until 1994 by cca. 25%. However, this decrease was primarily caused by the deep economic recession. Therefore the policy makers have to face the problem of economic recovery without a relevant increase of greenhouse gas emissions in the near future. This is the main focus of the mitigation analysis and the National Action Plan.

  19. Managing Normative Criteria in Action Research

    DEFF Research Database (Denmark)

    Boulus-Rødje, Nina

    2014-01-01

    experiences from an action research project in a healthcare infrastructural setting. I use these experiences as a basis for appraising the normative crite- ria for rigor and relevance that are enacted in IS action research literature. I argue that while these criteria originally had important contributions......, there are also weaknesses with norma- tive approaches. Specifically, these norms of action research leave relatively little space for understanding and managing emerging empirical uncertainties. These norms are important because they have implications not only on how we conduct action research in practice...... frameworks found in some IS action research literature with a reflexive framework that encourages researchers to investigate critically how their methods are enacted and practiced in the field. The contribution of this paper lies in pro- viding a reflexive analysis of the situated and emergent challenges...

  20. Effects of a tetracycline blended polylactic and polyglycolic acid membrane on the healing of one-wall intrabony defects in beagle dogs

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Il-Young [Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-752l (Korea, Republic of); Jung, Ui-Won [Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-752l (Korea, Republic of); Kim, Chang-Sung [Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-752l (Korea, Republic of); Lee, Yong-Keun [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-750 (Korea, Republic of); Cho, Kyoo-Sung [Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-752l (Korea, Republic of); Chai, Jung-Kiu [Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-752l (Korea, Republic of); Kim, Chong-Kwan [Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-752l (Korea, Republic of); Choi, Seong-Ho [Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-752l (Korea, Republic of)

    2007-09-15

    The purpose of this study was to evaluate the regenerative effects of a tetracycline blended polylactic and polyglycolic acid (TC-PLGA) and non-blended polylactic and polyglycolic acid (PLGA) barrier membrane on one-wall intrabony defects in beagle dogs. It can be concluded that when used for guided tissue regeneration TC-PLGA membranes show a beneficial effect on one-wall intrabony defects in beagle dogs.