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Sample records for expedient antibiotics production

  1. Expedient antibiotics production: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bienkowski, P.R.; Byers, C.H.; Lee, D.D.

    1988-05-01

    The literature on the manufacture, separation and purification, and clinical uses of antibiotics was reviewed, and a bibliography of the pertinent material was completed. Five antimicrobial drugs, penicillin V and G, (and amoxicillin with clavulanic acid), Cephalexin (a cephalosporin), tetracycline and oxytetracycline, Bacitracin (topical), and sulfonamide (chemically produced) were identified for emergency production. Plants that manufacture antibiotics in the continental United States, Mexico, and Puerto Rico have been identified along with potential alternate sites such as those where SCP, enzyme, and fermentation ethanol are produced. Detailed process flow sheets and process descriptions have been derived from the literature and documented. This investigation revealed that a typical antibiotic-manufacturing facility is composed of two main sections: (1) a highly specialized, but generic, fermentation unit and (2) a multistep, complex separation and purification unit which is specific to a particular antibiotic product. The fermentation section requires specialized equipment for operation in a sterile environment which is not usually available in other industries. The emergency production of antibiotics under austere conditions will be feasible only if a substantial reduction in the complexity and degree of separation and purity normally required can be realized. Detailed instructions were developed to assist state and federal officials who would be directing the resumption of antibiotic production after a nuclear attack. 182 refs., 54 figs., 26 tabs.

  2. Expedient

    Directory of Open Access Journals (Sweden)

    Fernando de Assis Rodrigues

    2017-07-01

    Full Text Available Expedient of Volume 3, Issue 1 from the year 2017EDITORIAL STAFFEditorsDiana Vilas Boas Souto AleixoFernando de Assis RodriguesEditorial ComissionDiana Vilas Boas Souto AleixoFernando de Assis RodriguesRicardo César Gonçalves Sant’AnaExecutive ComissionPedro Henrique Santos BisiAd hoc peer reviewersAna Carolina Simionato, Universidade Federal de São Carlos (UFSCarDiana Vilas Boas Souto Aleixo, Universidade Estadual Paulista (UNESPElaine Parra Affonso, Faculdade de Tecnologia de Presidente Prudente (FATEC - Universidade Estadual Paulista (UNESPElvio Gilberto da Silva, Universidade do Sagrado Coração (USCFábio Mosso Moreira, Universidade Estadual Paulista (UNESPThais Batista Zanineli, Universidade Estadual de Londrina (UELText reviewersDiana Vilas Boas Souto Aleixo, Universidade Estadual Paulista (UNESPElizabete Cristina de Souza Aguiar Monteiro (UNESP

  3. Antibiotics in Animal Products

    Science.gov (United States)

    Falcão, Amílcar C.

    The administration of antibiotics to animals to prevent or treat diseases led us to be concerned about the impact of these antibiotics on human health. In fact, animal products could be a potential vehicle to transfer drugs to humans. Using appropri ated mathematical and statistical models, one can predict the kinetic profile of drugs and their metabolites and, consequently, develop preventive procedures regarding drug transmission (i.e., determination of appropriate withdrawal periods). Nevertheless, in the present chapter the mathematical and statistical concepts for data interpretation are strictly given to allow understanding of some basic pharma-cokinetic principles and to illustrate the determination of withdrawal periods

  4. An Analysis of the Expediency Social Media for Culinary Products Marketing on Micro and Middle Enterprise in Pekanbaru City

    Science.gov (United States)

    Arisandi, Diki; Sukri

    2017-12-01

    Today, there are many culinary business can be found Pekanbaru city. To increase the benefit, the culinary entrepreneurs are using social media such as Facebook, twitter, instagram, whatsapp and others. This research discussed about the expediency of social media analysis for culinary products marketing on micro and middle enterprise in Pekanbaru by using structural equation modeling method. The Variables were used in this research are the selection of social media, updating information, response to costumers, quality and price as variable x to culinary business marketing as variable y. Data retrieval comes from a questionnaire filled by culinary entrepreneurs who are using social media to sell their product to customer in Pekanbaru. The result of this research displayed that the value of validity to the questionnaire was minimum = 0.083 and maximum = 0.547, RMSEA = 0.08, AGFI = 0.705, CMIN / DF = 1.834, TLI = 0.813 and CFI = 0.843. From the results of these measurements can be concluded that six of seven components of the measurement value can be avowed as acceptable, so the final result in this research is all the x variables have a positive influence on y variable.

  5. Iridium-Catalyzed Dynamic Kinetic Isomerization: Expedient Synthesis of Carbohydrates from Achmatowicz Rearrangement Products.

    Science.gov (United States)

    Wang, Hao-Yuan; Yang, Ka; Bennett, Scott R; Guo, Sheng-rong; Tang, Weiping

    2015-07-20

    A highly stereoselective dynamic kinetic isomerization of Achmatowicz rearrangement products was discovered. This new internal redox isomerization provided ready access to key intermediates for the enantio- and diastereoselective synthesis of a series of naturally occurring sugars. The nature of the de novo synthesis also enables the preparation of both enantiomers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Expediency of application of explosion-relief constructions to ensure explosion resistance of production buildings

    Directory of Open Access Journals (Sweden)

    Lyapin Anton

    2016-01-01

    Full Text Available The article presents a model of economic evaluation and selection of explosion-relief constructions (ERC, as well as determination of explosion protection efficiency of buildings and structures provided on a stage of construction. It has been shown that definition of economic efficiency of ERС is the evaluation of its application for buildings with remote or automatically controlled production. It has been determined that an important role in design of explosive industrial facilities is played by selection of the economically feasible and effective materials for ERC. When selecting materials it is necessary to consider probability and yield of explosions. Necessity to create the methods allow considering such probability has been revealed.

  7. Antibiotics: natural products essential to human health.

    Science.gov (United States)

    Demain, Arnold L

    2009-11-01

    For more than 50 years, natural products have served us well in combating infectious bacteria and fungi. Microbial and plant secondary metabolites helped to double our life span during the 20th century, reduced pain and suffering, and revolutionized medicine. Most antibiotics are either (i) natural products of microorganisms, (ii) semi-synthetically produced from natural products, or (iii) chemically synthesized based on the structure of the natural products. Production of antibiotics began with penicillin in the late 1940s and proceeded with great success until the 1970-1980s when it became harder and harder to discover new and useful products. Furthermore, resistance development in pathogens became a major problem, which is still with us today. In addition, new pathogens are continually emerging and there are still bacteria that are not eliminated by any antibiotic, e.g., Pseudomonas aeruginosa. In addition to these problems, many of the major pharmaceutical companies have abandoned the antibiotic field, leaving much of the discovery efforts to small companies, new companies, and the biotechnology industries. Despite these problems, development of new antibiotics has continued, albeit at a much lower pace than in the last century. We have seen the (i) appearance of newly discovered antibiotics (e.g., candins), (ii) development of old but unutilized antibiotics (e.g., daptomycin), (iii) production of new semi-synthetic versions of old antibiotics (e.g., glycylcyclines, streptogrammins), as well as the (iv) very useful application of old but underutilized antibiotics (e.g., teicoplanin).

  8. The Biogeography of Putative Microbial Antibiotic Production

    Science.gov (United States)

    Bryant, Jessica A.; Charkoudian, Louise K.; Docherty, Kathryn M.; Jones, Evan; Kembel, Steven W.; Green, Jessica L.; Bohannan, Brendan J. M.

    2015-01-01

    Understanding patterns in the distribution and abundance of functional traits across a landscape is of fundamental importance to ecology. Mapping these distributions is particularly challenging for species-rich groups with sparse trait measurement coverage, such as flowering plants, insects, and microorganisms. Here, we use likelihood-based character reconstruction to infer and analyze the spatial distribution of unmeasured traits. We apply this framework to a microbial dataset comprised of 11,732 ketosynthase alpha gene sequences extracted from 144 soil samples from three continents to document the spatial distribution of putative microbial polyketide antibiotic production. Antibiotic production is a key competitive strategy for soil microbial survival and performance. Additionally, novel antibiotic discovery is highly relevant to human health, making natural antibiotic production by soil microorganisms a major target for bioprospecting. Our comparison of trait-based biogeographical patterns to patterns based on taxonomy and phylogeny is relevant to our basic understanding of microbial biogeography as well as the pressing need for new antibiotics. PMID:26102275

  9. The Biogeography of Putative Microbial Antibiotic Production.

    Directory of Open Access Journals (Sweden)

    Hélène Morlon

    Full Text Available Understanding patterns in the distribution and abundance of functional traits across a landscape is of fundamental importance to ecology. Mapping these distributions is particularly challenging for species-rich groups with sparse trait measurement coverage, such as flowering plants, insects, and microorganisms. Here, we use likelihood-based character reconstruction to infer and analyze the spatial distribution of unmeasured traits. We apply this framework to a microbial dataset comprised of 11,732 ketosynthase alpha gene sequences extracted from 144 soil samples from three continents to document the spatial distribution of putative microbial polyketide antibiotic production. Antibiotic production is a key competitive strategy for soil microbial survival and performance. Additionally, novel antibiotic discovery is highly relevant to human health, making natural antibiotic production by soil microorganisms a major target for bioprospecting. Our comparison of trait-based biogeographical patterns to patterns based on taxonomy and phylogeny is relevant to our basic understanding of microbial biogeography as well as the pressing need for new antibiotics.

  10. The Biogeography of Putative Microbial Antibiotic Production.

    Science.gov (United States)

    Morlon, Hélène; O'Connor, Timothy K; Bryant, Jessica A; Charkoudian, Louise K; Docherty, Kathryn M; Jones, Evan; Kembel, Steven W; Green, Jessica L; Bohannan, Brendan J M

    2015-01-01

    Understanding patterns in the distribution and abundance of functional traits across a landscape is of fundamental importance to ecology. Mapping these distributions is particularly challenging for species-rich groups with sparse trait measurement coverage, such as flowering plants, insects, and microorganisms. Here, we use likelihood-based character reconstruction to infer and analyze the spatial distribution of unmeasured traits. We apply this framework to a microbial dataset comprised of 11,732 ketosynthase alpha gene sequences extracted from 144 soil samples from three continents to document the spatial distribution of putative microbial polyketide antibiotic production. Antibiotic production is a key competitive strategy for soil microbial survival and performance. Additionally, novel antibiotic discovery is highly relevant to human health, making natural antibiotic production by soil microorganisms a major target for bioprospecting. Our comparison of trait-based biogeographical patterns to patterns based on taxonomy and phylogeny is relevant to our basic understanding of microbial biogeography as well as the pressing need for new antibiotics.

  11. Chemical ecology of antibiotic production by actinomycetes

    NARCIS (Netherlands)

    Van der Meij, Anne; Worsley, Sarah F.; Hutchings, Matthew I.; van Wezel, Gilles P.

    Actinomycetes are a diverse family of filamentous bacteria that produce a plethora of natural products relevant for agriculture, biotechnology and medicine, including the majority of the antibiotics we use in the clinic. Rather than as free-living bacteria, many actinomycetes have evolved to live in

  12. Antibiotics in Canadian poultry productions and anticipated alternatives

    OpenAIRE

    Moussa Sory Diarra; Francois eMalouin

    2014-01-01

    The use of antibiotics in food-producing animals has significantly increased animal health by lowering mortality and the incidence of diseases. Antibiotics also have largely contributed to increase productivity of farms. However, antibiotic usage in general and relevance of non-therapeutic antibiotics in feed (growth promoters) need to be reevaluated especially because bacterial pathogens of humans and animals have developed and shared a variety of antibiotic resistance mechanisms that can ea...

  13. Environmental impacts of antibiotic use in the animal production industry

    Science.gov (United States)

    Antibiotics are routinely used in the livestock industry to treat and prevent disease. At subtherapeutic concentrations, antibiotics can select for resistant bacteria in the gastrointestinal tract of production animals, providing a potential reservoir for dissemination of drug resistant bacteria int...

  14. Botanical alternatives to antibiotics for use in organic poultry production.

    Science.gov (United States)

    Diaz-Sanchez, Sandra; D'Souza, Doris; Biswas, Debrabrata; Hanning, Irene

    2015-06-01

    The development of antibiotic resistant pathogens has resulted from the use of sub-therapeutic concentrations of antibiotics delivered in poultry feed. Furthermore, there are a number of consumer concerns regarding the use of antibiotics in food animals including residue contamination of poultry products and antibiotic resistant bacterial pathogens. These issues have resulted in recommendations to reduce the use of antibiotics as growth promoters in livestock in the United States. Unlike conventional production, organic systems are not permitted to use antibiotics. Thus, both conventional and organic poultry production need alternative methods to improve growth and performance of poultry. Herbs, spices, and various other plant extracts are being evaluated as alternatives to antibiotics and some do have growth promoting effects, antimicrobial properties, and other health-related benefits. This review aims to provide an overview of herbs, spices, and plant extracts, currently defined as phytobiotics as potential feed additives. © 2015 Poultry Science Association Inc.

  15. Antibiotics in Canadian poultry productions and anticipated alternatives.

    Science.gov (United States)

    Diarra, Moussa S; Malouin, François

    2014-01-01

    The use of antibiotics in food-producing animals has significantly increased animal health by lowering mortality and the incidence of diseases. Antibiotics also have largely contributed to increase productivity of farms. However, antibiotic usage in general and relevance of non-therapeutic antibiotics (growth promoters) in feed need to be reevaluated especially because bacterial pathogens of humans and animals have developed and shared a variety of antibiotic resistance mechanisms that can easily be spread within microbial communities. In Canada, poultry production involves more than 2600 regulated chicken producers who have access to several antibiotics approved as feed additives for poultry. Feed recipes and mixtures vary greatly geographically and from one farm to another, making links between use of a specific antibiotic feed additive and production yields or selection of specific antibiotic-resistant bacteria difficult to establish. Many on-farm studies have revealed the widespread presence of antibiotic-resistant bacteria in broiler chickens. While some reports linked the presence of antibiotic-resistant organisms to the use of feed supplemented with antibiotics, no recent studies could clearly demonstrate the benefit of antimicrobial growth promoters on performance and production yields. With modern biosecurity and hygienic practices, there is a genuine concern that intensive utilization of antibiotics or use of antimicrobial growth promoters in feed might no longer be useful. Public pressure and concerns about food and environmental safety (antibiotic residues, antibiotic-resistant pathogens) have driven researchers to actively look for alternatives to antibiotics. Some of the alternatives include pre- and probiotics, organic acids and essential oils. We will describe here the properties of some bioactive molecules, like those found in cranberry, which have shown interesting polyvalent antibacterial and immuno-stimulatory activities.

  16. Antibiotics in Canadian poultry productions and anticipated alternatives

    Directory of Open Access Journals (Sweden)

    Moussa Sory Diarra

    2014-06-01

    Full Text Available The use of antibiotics in food-producing animals has significantly increased animal health by lowering mortality and the incidence of diseases. Antibiotics also have largely contributed to increase productivity of farms. However, antibiotic usage in general and relevance of non-therapeutic antibiotics in feed (growth promoters need to be reevaluated especially because bacterial pathogens of humans and animals have developed and shared a variety of antibiotic resistance mechanisms that can easily spread within microbial communities. In Canada, poultry production involves more than 2,600 regulated chicken producers. There are several antibiotics approved as feed additives available for poultry farmers. Feed recipes and mixtures greatly vary geographically and from one farm to another, making links between use of a specific antibiotic feed additive and production yields or selection of specific antibiotic-resistant bacteria difficult to establish. Many on-farm studies have revealed the widespread presence of antibiotic-resistant bacteria in broiler chickens. While sporadic reports linked the presence of antibiotic-resistant organisms to the use of feed supplemented with antibiotics, no recent studies could clearly demonstrate the benefit of antimicrobial growth promoters on performance and production yields. With modern biosecurity and hygienic practices, there is a genuine concern that intensive utilization of antibiotics or use of antimicrobial growth promoters in feed might no longer be useful. Public pressure and concerns about food and environmental safety (antibiotic residues, antibiotic-resistant pathogens have driven researchers to actively look for alternatives to antibiotics. Some of the alternatives include pre- and probiotics, organic acids and essential oils. We will describe here the properties of some bioactive molecules, like those found in cranberry, which have shown interesting polyvalent antibacterial and immuno

  17. Listeria monocytogenes: antibiotic resistance in food production.

    Science.gov (United States)

    Lungu, Bwalya; O'Bryan, Corliss A; Muthaiyan, Arunachalam; Milillo, Sara R; Johnson, Michael G; Crandall, Philip G; Ricke, Steven C

    2011-05-01

    Listeria monocytogenes is an opportunistic human pathogen that causes listeriosis, a disease that mainly affects the immunocompromised, the elderly, infants, and pregnant women. Listeriosis has become increasingly common in the last 25 years since the first foodborne outbreak was noted. Treatment for listeriosis currently consists primarily of supportive therapy in conjunction with the use of intravenous antibiotics. Antibiotics have been commercially available for over 60 years for treatment of a myriad of clinical diseases. Bacteria resistant to antibiotics have been developing over this same period. This review seeks to elucidate the extent of antibiotic resistance in L. monocytogenes, the possible transmission mechanisms, and contributing factors to distribution of antibiotic resistance among Listeria species, and possible control strategies.

  18. Genetic analysis of antibiotic production and other phenotypic traits ...

    African Journals Online (AJOL)

    So, the present study made an attempt to study the genetics of production of antibiotic and other phenotypic properties was demonstrated by plasmid DNA curing analysis. The DNA-intercalating agent ethidium bromide was used to eliminate plasmid DNA from streptomycetes and effects of curing agent (EB) on the antibiotic ...

  19. Toyota production system quality improvement initiative improves perioperative antibiotic therapy.

    Science.gov (United States)

    Burkitt, Kelly H; Mor, Maria K; Jain, Rajiv; Kruszewski, Matthew S; McCray, Ellesha E; Moreland, Michael E; Muder, Robert R; Obrosky, David Scott; Sevick, Mary Ann; Wilson, Mark A; Fine, Michael J

    2009-09-01

    To assess the role of a Toyota production system (TPS) quality improvement (QI) intervention on appropriateness of perioperative antibiotic therapy and in length of hospital stay (LOS) among surgical patients. Pre-post quasi-experimental study using local and national retrospective cohorts. We used TPS methods to implement a multifaceted intervention to reduce nosocomial methicillin-resistant Staphylococcus aureus infections on a Veterans Affairs surgical unit, which led to a QI intervention targeting appropriate perioperative antibiotic prophylaxis. Appropriate perioperative antibiotic therapy was defined as selection of the recommended antibiotic agents for a duration not exceeding 24 hours from the time of the operation. The local computerized medical record system was used to identify patients undergoing the 25 most common surgical procedures and to examine changes in appropriate antibiotic therapy and LOS over time. Overall, 2550 surgical admissions were identified from the local computerized medical records. The proportion of surgical admissions receiving appropriate perioperative antibiotics was significantly higher (P <.01) in 2004 after initiation of the TPS intervention (44.0%) compared with the previous 4 years (range, 23.4%-29.8%) primarily because of improvements in compliance with antibiotic therapy duration rather than appropriate antibiotic selection. There was no statistically significant decrease in LOS over time. The use of TPS methods resulted in a QI intervention that was associated with an increase in appropriate perioperative antibiotic therapy among surgical patients, without affecting LOS.

  20. Biofilm production and antibiotic susceptibility profiles of ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    Oct 24, 2011 ... determining the biofilm producing capability and antibiotic resistance profiles of the S. aureus isolated from drinking water and clinical samples from HIV patients in the Limpopo Province. S. aureus strains isolated from clinical samples including urine, sputum, and stools obtained from HIV and AIDS patients.

  1. Antibiotic production by bacterial biocontrol agents

    NARCIS (Netherlands)

    Raaijmakers, J.M.; Vlami, M.; Souza, de J.T.

    2002-01-01

    Interest in biological control of plant pathogens has been stimulated in recent years by trends in agriculture towards greater sustainability and public concern about the use of hazardous pesticides. There is now unequivocal evidence that antibiotics play a key role in the suppression of various

  2. Biofilm production and antibiotic susceptibility profiles of ...

    African Journals Online (AJOL)

    Staphylococcus aureus is a common pathogen associated with nosocomial as well as community acquired infections. Despite multiple reports on the severity and recurrent nature of S. aureus infection, the pathogenesis as well as antibiotic susceptibility profiles of S. aureus infecting HIV and AIDS patients has not been well ...

  3. Antibiotic use in Brazilian broiler and pig production: an indication and forecast of trends

    NARCIS (Netherlands)

    Bokma-Bakker, M.H.; Bondt, N.; Neijenhuis, F.; Mevius, D.J.; Ruiter, S.J.M.

    2014-01-01

    To gain insight in antibiotic use in relation to imported products the current use of antibiotics in pork and broiler production in Brazil are identified and trend forecasting of antibiotic use in the coming 3-5 years is performed.

  4. Control of fluxes towards antibiotics and the role of primary metabolism in production of antibiotics

    DEFF Research Database (Denmark)

    Gunnarsson, Nina; Eliasson Lantz, Anna; Nielsen, Jacob

    2004-01-01

    Yield improvements in antibiotic-producing strains have classically been obtained through random mutagenesis and screening. An attractive alternative to this strategy is the rational design of producer strains via metabolic engineering, an approach that offers the possibility to increase yields...... in the metabolic network. Here we describe and discuss available methods for identification of these steps, both in antibiotic biosynthesis pathways and in the primary metabolism, which serves as the supplier of precursors and cofactors for the secondary metabolism. Finally, the importance of precursor...... and cofactor supply from primary metabolism in the biosynthesis of different types of antibiotics is discussed and recent developments in metabolic engineering towards increased product yields in antibiotic producing strains are reviewed....

  5. 21 CFR 333.150 - Labeling of first aid antibiotic drug products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Labeling of first aid antibiotic drug products... First Aid Antibiotic Drug Products § 333.150 Labeling of first aid antibiotic drug products. (a... identifies the product as a “first aid antibiotic.” (b) Indications. The labeling of the product states...

  6. Counteraction of antibiotic production and degradation stabilizes microbial communities

    Science.gov (United States)

    Kelsic, Eric D.; Zhao, Jeffrey; Vetsigian, Kalin; Kishony, Roy

    2015-01-01

    Summary A major challenge in theoretical ecology is understanding how natural microbial communities support species diversity1-8, and in particular how antibiotic producing, sensitive and resistant species coexist9-15. While cyclic “rock-paper-scissors” interactions can stabilize communities in spatial environments9-11, coexistence in unstructured environments remains an enigma12,16. Here, using simulations and analytical models, we show that the opposing actions of antibiotic production and degradation enable coexistence even in well-mixed environments. Coexistence depends on 3-way interactions where an antibiotic degrading species attenuates the inhibitory interactions between two other species. These 3-way interactions enable coexistence that is robust to substantial differences in inherent species growth rates and to invasion by “cheating” species that cease producing or degrading antibiotics. At least two antibiotics are required for stability, with greater numbers of antibiotics enabling more complex communities and diverse dynamical behaviors ranging from stable fixed-points to limit cycles and chaos. Together, these results show how multi-species antibiotic interactions can generate ecological stability in both spatial and mixed microbial communities, suggesting strategies for engineering synthetic ecosystems and highlighting the importance of toxin production and degradation for microbial biodiversity. PMID:25992546

  7. Expedient Road Construction Over Soft Soils

    National Research Council Canada - National Science Library

    Santoni, Rosa

    2001-01-01

    This report describes field experiments conducted using a combination of crushed limestone, wood chips, sand, geosynthetics, fiberglass mats, plastic mats, and wood mats for expedient road construction over soft soils...

  8. Metabolic engineering of antibiotic factories: New tools for antibiotic production in actinomycetes

    DEFF Research Database (Denmark)

    Weber, Tilmann; Charusanti, Pep; Musiol-Kroll, Ewa Maria

    2015-01-01

    Actinomycetes are excellent sources for novel bioactive compounds, which serve as potential drug candidates for antibiotics development. While industrial efforts to find and develop novel antimicrobials have been severely reduced during the past two decades, the increasing threat of multidrug...... them, and to express them in heterologous hosts in much higher throughput than before. These technologies now enable metabolic engineering approaches to optimize production yields and to directly manipulate the pathways to generate modified products....

  9. Production of Antibiotics from Soil-Isolated Actinomycetes and ...

    African Journals Online (AJOL)

    Purpose: To investigate the production of antibiotic from actinomycetes isolated from soil and evaluate its antimicrobial activities. Methods: In a medium formulation study, A-4 and A-4 actinomycete mutant strains (out of the six strains selected from the nine actinomycetes that were screened) were evaluated for maximum ...

  10. Antibiotic Susceptibility Pattern and Beta-Lactamase Production of ...

    African Journals Online (AJOL)

    Nigerian Journal of Biomedical Sciences Vol.3(2) 2004: The study was to determine the antibiotic susceptibility patterns and beta-lactamase production of Campylobacter jejuni/coli isolates obtained from stool specimens from children with diarrhoea at the Obafemi Awolowo University Teaching Hospital Complex ...

  11. Environmental and metabolomic study of antibiotic production by actinomycetes

    NARCIS (Netherlands)

    Zhu, Hua

    2014-01-01

    This thesis may be regarded as a concept work, to see how feasible drug discovery approaches still are. For this, a strain collection was built up consisting of actinomycetes from soil in the Qinling and Himalaya mountains, which were subsequently tested for antibiotic production against multi-drug

  12. Growth promoting antibiotics in food animal production: an economic analysis.

    Science.gov (United States)

    Graham, Jay P; Boland, John J; Silbergeld, Ellen

    2007-01-01

    Considerable controversy persists regarding the use of human antibiotics to promote growth in animals raised for food. The authors examined the economic effect of removing antibiotics used for growth promotion in commercial broiler chickens. The authors utilized data published by the Perdue company, the fourth largest poultry producer in the United States, in which a non-randomized controlled trial of growth-promoting antibiotic (GPA) use was conducted with seven million broiler chickens to evaluate the impact of removing GPAs on production. Positive production changes were associated with GPA use, but were insufficient to offset the cost of the antibiotics. The net effect of using GPAs was a lost value of 0.0093 dollars per chicken (about 0.45% of total cost). Based upon these data, the authors found no basis for the claim that the use of GPAs lowers the cost of production. Note that this study does not include veterinary cost changes or changes in performance variability associated with the removal of GPAs. This economic analysis is the first study to the authors' knowledge utilizing large-scale empirical data collected by U.S. industry, in which it is demonstrated that the use of GPAs in poultry production is associated with economic losses to the producers. These data are of considerable importance in the ongoing national debate concerning the continued use of antibiotics for growth promotion of food animals. Based on the industry study and the resulting economic impact, the use of GPAs in U.S. poultry production should be reconsidered.

  13. From Discovery to Production: Biotechnology of Marine Fungi for the Production of New Antibiotics

    Science.gov (United States)

    Silber, Johanna; Kramer, Annemarie; Labes, Antje; Tasdemir, Deniz

    2016-01-01

    Filamentous fungi are well known for their capability of producing antibiotic natural products. Recent studies have demonstrated the potential of antimicrobials with vast chemodiversity from marine fungi. Development of such natural products into lead compounds requires sustainable supply. Marine biotechnology can significantly contribute to the production of new antibiotics at various levels of the process chain including discovery, production, downstream processing, and lead development. However, the number of biotechnological processes described for large-scale production from marine fungi is far from the sum of the newly-discovered natural antibiotics. Methods and technologies applied in marine fungal biotechnology largely derive from analogous terrestrial processes and rarely reflect the specific demands of the marine fungi. The current developments in metabolic engineering and marine microbiology are not yet transferred into processes, but offer numerous options for improvement of production processes and establishment of new process chains. This review summarises the current state in biotechnological production of marine fungal antibiotics and points out the enormous potential of biotechnology in all stages of the discovery-to-development pipeline. At the same time, the literature survey reveals that more biotechnology transfer and method developments are needed for a sustainable and innovative production of marine fungal antibiotics. PMID:27455283

  14. Screening of Bacillus Species with Potentials of Antibiotics Production

    Directory of Open Access Journals (Sweden)

    Faruk Adamu KUTA

    2009-07-01

    Full Text Available Sixteen soil samples were collected from different refuse dump sites in Minna, the capital Niger State, and analysed for the presence of Bacillus species. Physical-chemical analysis of the soil samples revealed the followings: PH value 6.89-8.47; moisture content 1.58 – 21.21% and temperature 27-28ºC. Using both pour plate and streak method of inoculation, total bacterial count in the soil samples ranged from 3.8×104 cfu/g 16.0×104 cfu/g. The identified Bacillus species included: Bacillus cereus (30.8%, Bacillus brevis (1.9% Bacillus polymyxa (3.8%, Bacillus lichenifomis (13.5%, Bacillus spherericus (7.7%, Bacillus mycoides (13.5%, Bacillus pumilus (7.7%, Bacillus subtilis (3.8%, Bacillus alvei (1.9%, Bacillus laterosporous (1.9%, Bacillus firmus (9.6% and Bacillus circulars (3.8%. Antibiotic production tests indicated that nine Bacillus species out of twelve isolated in this study could be used to produce antibiotics that had effect on the test organisms. However, Bacillus polymyxa, Bacillus sphaericus and Bacillus laterosporous had little or no effect on the tested organisms. This study suggests that some Bacillus species have potential to produce high quality antibiotics that can be use to control microbial growth in future.

  15. Managing neurobehavioral capability when social expediency trumps biological imperatives

    Science.gov (United States)

    Spaeth, Andrea M.; Goel, Namni; Dinges, David F.

    2013-01-01

    Sleep, which is evolutionarily conserved across species, is a biological imperative that cannot be ignored or replaced. However, the percentage of habitually sleep-restricted adults has increased in recent decades. Extended work hours and commutes, shift work schedules, and television viewing are particularly potent social factors that influence sleep duration. Chronic partial sleep restriction, a product of these social expediencies, leads to the accumulation of sleep debt over time and consequently increases sleep propensity, decreases alertness, and impairs critical aspects of cognitive functioning. Significant interindividual variability in the neurobehavioral responses to sleep restriction exists—this variability is stable and phenotypic—suggesting a genetic basis. Identifying vulnerability to sleep loss is essential as many adults cannot accurately judge their level of impairment in response to sleep restriction. Indeed, the consequences of impaired performance and the lack of insight due to sleep loss can be catastrophic. In order to cope with the effects of social expediencies on biological imperatives, identification of biological (including genetic) and behavioral markers of sleep loss vulnerability as well as development of technological approaches for fatigue management are critical. PMID:22877676

  16. Report: antibiotic production by thermophilic Bacillus specie SAT-4.

    Science.gov (United States)

    Muhammad, Syed Aun; Ahmad, Safia; Hameed, Abdul

    2009-07-01

    Production of antimicrobial compounds seems to be a general phenomenon for most bacteria. The prevalence of antimicrobial resistance among key microbial pathogens is increasing at an alarming rate worldwide. Current solutions involve development of a more rationale approach to antibiotic use and discover of new antimicrobials. Bacillus species produce a large number of biological compounds active against bacteria, fungi, protozoa and viruses. The process of production usually involves screening of wide range of microorganisms, testing and modification. Production is carried out using fermentation. Thermophilic spore-forming, gram positive, motile rod bacterial strains were isolated from the Thar Desserts, Sindh Province, Pakistan. These strains were screened and checked for antibacterial activity. The best activity was observed by SAT4 against Micrococcus luteus, Staphylococcus aureus and Pseudomonas aeroginosa. The activity was only observed against gram positive bacteria and no activity was seen against Pseudomonas aeroginosa. Thermophilic Bacillus specie SAT4 was found to be active in the fermentation process to produce the antimicrobial agents. Further optimizations of different conditions (time of incubation, media, pH, glucose concentrations, nitrogen concentrations, and temperature) for antimicrobial production by the selected bacterial strain was performed. Agar diffusion assay was performed to evaluate the antibacterial activity. Optimum conditions for the production of antimicrobials by selected isolate were observed to be 48 hour, pH 5, temperature 55 degrees C, 2% glucose and 1.5% nitrogen concentration. This newly isolated bacterial strain has great potential for antimicrobial production at industrial scale.

  17. Dietary risk ranking for residual antibiotics in cultured aquatic products around Tai Lake, China.

    Science.gov (United States)

    Song, Chao; Li, Le; Zhang, Cong; Qiu, Liping; Fan, Limin; Wu, Wei; Meng, Shunlong; Hu, Gengdong; Chen, Jiazhang; Liu, Ying; Mao, Aimin

    2017-10-01

    Antibiotics are widely used in aquaculture and therefore may be present as a dietary risk in cultured aquatic products. Using the Tai Lake Basin as a study area, we assessed the presence of 15 antibiotics in 5 widely cultured aquatic species using a newly developed dietary risk ranking approach. By assigning scores to each factor involved in the ranking matrices, the scores of dietary risks per antibiotic and per aquatic species were calculated. The results indicated that fluoroquinolone antibiotics posed the highest dietary risk in all aquatic species. Then, the total scores per aquatic species were summed by all 15 antibiotic scores of antibiotics, it was found that Crab (Eriocheir sinensis) had the highest dietary risks. Finally, the most concerned antibiotic category and aquatic species were selected. This study highlighted the importance of dietary risk ranking in the production and consumption of cultured aquatic products around Tai Lake. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Antibiotic Susceptibility Pattern and Beta-lactamase Production in ...

    African Journals Online (AJOL)

    Of the 102 isolates, 30(29.4%) strains possessed β-lactamase and the minimum inhibitory concentration (MIC) of selected antibiotics was in the range of 3.95– 250μg/ml. The multiple drug resistance as evident in high MICs of the antibiotics tested could probably be due to abuse/misuse of antibiotics resulting in recurrence ...

  19. [Influence of personal attitude of the manager on antibiotic use in pig production].

    Science.gov (United States)

    Malik, J; Kaufmann, G; Hirsiger, P; Kümmerlen, D; Arnold, C; Spring, P; Sidler, X

    2015-12-01

    The attitude as well as the expertise of a person affect the behavior and actions in daily life. To investigate the influence of attitude and knowledge of pig producers on the use of antibiotics in farms, 220 Swiss pig producers were questioned on health awareness, attitude towards sustainable production, risk behavior, intrinsic motivation and knowledge about antibiotics and resistance development. In addition, the strategy of antibiotic use (therapeutic or prophylactic) and the business practice (single or group therapy) for the amount of antibiotics on one hand and for the risk of antibiotic resistance development on the other hand, were determined in a personal interview. Farmers using antibiotics only therapeutically had a better business practice. A direct link between the personal attitude and the antibiotic use or a higher risk of development of antibiotic resistance was not found in this investigation.

  20. Consumer Demand for a Ban on Antibiotic Drug Use in Pork Production

    OpenAIRE

    Jayson L. Lusk; Norwood, F. Bailey; Pruitt, J. Ross

    2006-01-01

    Consumer demand for a ban on subtherapeutic antibiotic use in pork production is measured using non-hypothetical choice experiments in a grocery store setting. Consumers are asked to choose between a regular pork chop plus a grocery coupon and an antibiotic-friendly pork chop without a coupon. Other consumers are asked to choose between a donation towards reducing antibiotic resistance and grocery coupons. These experiments reveal the private and public value consumers place on a ban, which i...

  1. Complementary or alternative? The use of homeopathic products and antibiotics amongst pre-school children

    Directory of Open Access Journals (Sweden)

    Bishop Jackie

    2008-01-01

    Full Text Available Abstract Background Any intervention to reduce the inappropriate use of antibiotics for infections in children has the potential to reduce the selective pressure on antimicrobial resistance and minimise the medicalisation of self-limiting illness. Little is known about whether homeopathic products might be used by some families as an alternative to antibiotics or the characteristics of such families. We used the Avon Longitudinal Study of Parents and Children (ALSPAC observational dataset to explore the hypothesis that the use of homeopathic products is associated with reduced antibiotic use in pre-school children and to identify characteristics of the families of pre-school children given homeopathic products. Methods Questionnaires data were completed by the parents of 9723 children while aged between 3–4.5 years in Bristol UK. Univariable and multivariable analyses were used to explore the relationships between antibiotic and homeopathic product use. Results Six percent of children had received one or more homeopathic products and 62% one or more antibiotics between the ages of 3 and 4.5 years. After adjustment for factors associated with antibiotic use, there was no association between homeopathic product and antibiotic use (adjusted OR = 1.02, 95% CI 0.84, 1.24. Factors independently associated with child homeopathic product use were: higher maternal education, maternal use of homeopathic products, maternal lack of confidence in doctors, mothers reporting that they were less likely to see doctor when the child was ill, children being given vitamins, watching less television and suffering from wheeze and food allergies. Conclusion In this observational study, the use of homeopathic products was not associated with decreased antibiotic consumption, suggesting the use of homeopathic product complements rather than competes with the use of antibiotics in pre-school children. The characteristics of mothers giving homeopathic products to their

  2. Mobile antibiotic resistance – the spread of genes determining the resistance of bacteria through food products

    Directory of Open Access Journals (Sweden)

    Jolanta Godziszewska

    2016-07-01

    Full Text Available In recent years, more and more antibiotics have become ineffective in the treatment of bacterial nfections. The acquisition of antibiotic resistance by bacteria is associated with circulation of genes in the environment. Determinants of antibiotic resistance may be transferred to pathogenic bacteria. It has been shown that conjugation is one of the key mechanisms responsible for spread of antibiotic resistance genes, which is highly efficient and allows the barrier to restrictions and modifications to be avoided. Some conjugative modules enable the transfer of plasmids even between phylogenetically distant bacterial species. Many scientific reports indicate that food is one of the main reservoirs of these genes. Antibiotic resistance genes have been identified in meat products, milk, fruits and vegetables. The reason for such a wide spread of antibiotic resistance genes is the overuse of antibiotics by breeders of plants and animals, as well as by horizontal gene transfer. It was shown, that resistance determinants located on mobile genetic elements, which are isolated from food products, can easily be transferred to another niche. The antibiotic resistance genes have been in the environment for 30 000 years. Their removal from food products is not possible, but the risks associated with the emergence of multiresistant pathogenic strains are very large. The only option is to control the emergence, selection and spread of these genes. Therefore measures are sought to prevent horizontal transfer of genes. Promising concepts involve the combination of developmental biology, evolution and ecology in the fight against the spread of antibiotic resistance.

  3. Limited bacterial diversity within a treatment plant receiving antibiotic containing waste from bulk drug production

    NARCIS (Netherlands)

    Marathe, Nachiket P.; Shetty, Sudarshan A.; Shouche, Yogesh S.; Larsson, D.G.J.

    2016-01-01

    Biological treatment of waste water from bulk drug production, contaminated with high levels of fluoroquinolone antibiotics, can lead to massive enrichment of antibiotic resistant bacteria, resistance genes and associated mobile elements, as previously shown. Such strong selection may be boosted

  4. Antibiotics production by bacterial agents and its role in biological control

    NARCIS (Netherlands)

    Wang, G.; Raaijmakers, J.M.

    2004-01-01

    Using bacteria to control plant diseases is one of the main strategies in plant protection, and its mechanism is commonly thought to be the production of antibiotics by bacteria. The produced antibiotics not only have structural diversity, but also have broad-spectrum activity against many

  5. Antibiotic resistance--consequences for animal health, welfare, and food production.

    Science.gov (United States)

    Bengtsson, Björn; Greko, Christina

    2014-05-01

    Most of the literature on the consequences of emergence and spread of bacteria resistant to antibiotics among animals relate to the potential impact on public health. But antibiotics are used to treat sick animals, and resistance in animal pathogens may lead to therapy failure. This has received little scientific attention, and therefore, in this article, we discuss examples that illustrate the possible impact of resistance on animal health and consequences thereof. For all animals, there may be a negative effect on health and welfare when diseases cannot be treated. Other consequences will vary depending on why and how different animal species are kept. Animals kept as companions or for sports often receive advanced care, and antibiotic resistance can lead to negative social and economic consequences for the owners. Further, spread of hospital-acquired infections can have an economic impact on the affected premises. As to animals kept for food production, antibiotics are not needed to promote growth, but, if infectious diseases cannot be treated when they occur, this can have a negative effect on the productivity and economy of affected businesses. Antibiotic resistance in animal bacteria can also have positive consequences by creating incentives for adoption of alternative regimes for treatment and prevention. It is probable that new antibiotic classes placed on the market in the future will not reach veterinary medicine, which further emphasizes the need to preserve the efficacy of currently available antibiotics through antibiotic stewardship. A cornerstone in this work is prevention, as healthy animals do not need antibiotics.

  6. Genome Engineering and Modification Toward Synthetic Biology for the Production of Antibiotics.

    Science.gov (United States)

    Zou, Xuan; Wang, Lianrong; Li, Zhiqiang; Luo, Jie; Wang, Yunfu; Deng, Zixin; Du, Shiming; Chen, Shi

    2017-03-15

    Antibiotic production is often governed by large gene clusters composed of genes related to antibiotic scaffold synthesis, tailoring, regulation, and resistance. With the expansion of genome sequencing, a considerable number of antibiotic gene clusters has been isolated and characterized. The emerging genome engineering techniques make it possible towards more efficient engineering of antibiotics. In addition to genomic editing, multiple synthetic biology approaches have been developed for the exploration and improvement of antibiotic natural products. Here, we review the progress in the development of these genome editing techniques used to engineer new antibiotics, focusing on three aspects of genome engineering: direct cloning of large genomic fragments, genome engineering of gene clusters, and regulation of gene cluster expression. This review will not only summarize the current uses of genomic engineering techniques for cloning and assembly of antibiotic gene clusters or for altering antibiotic synthetic pathways but will also provide perspectives on the future directions of rebuilding biological systems for the design of novel antibiotics. © 2017 Wiley Periodicals, Inc.

  7. Antibiotic-free selection in E. coli: new considerations for optimal design and improved production

    Directory of Open Access Journals (Sweden)

    Peubez Isabelle

    2010-09-01

    Full Text Available Abstract Background The increasing regulatory requirements to which biological agents are subjected will have a great impact in the field of industrial protein expression and production. There is an expectation that in a near future, there may be "zero tolerance" towards antibiotic-based selection and production systems. Besides the antibiotic itself, the antibiotic resistance gene is an important consideration. The complete absence of antibiotic-resistance gene being the only way to ensure that there is no propagation in the environment or transfer of resistance to pathogenic strains. Results In a first step, we have designed a series of vectors, containing a stabilization element allowing a complete elimination of antibiotics during fermentation. Vectors were further improved in order to include alternative selection means such as the well known poison/antidote stabilization system. Eventually we propose an elegant positive pressure of selection ensuring the elimination of the antibiotic-resistance gene through homologous recombination. In addition, we have shown that the presence of an antibiotic resistance gene can indirectly reduce the amount of expressed protein, since even in absence of selection pressure the gene would be transcribed and account for an additional stress for the host during the fermentation process. Conclusions We propose a general strategy combining plasmid stabilization and antibiotic-free selection. The proposed host/vector system, completely devoid of antibiotic resistance gene at the end of construction, has the additional advantage of improving recombinant protein expression and/or plasmid recovery.

  8. Attitude of broiler breeders toward the production of antibiotics-free chickens (case study: Tehran province

    Directory of Open Access Journals (Sweden)

    A Behrouzi

    2016-01-01

    Full Text Available Abstract: This research aimed to investigate the attitude of broiler breeders toward the production of antibiotics-free chickens in Tehran province. The statistical population in this study included all broiler breeders (N=450 in Tehran province. Using stratified-random-sampling method 136 breeders were selected. The main tool for data gathering was a questionnaire contained 44 questions and items. Results showed that 52.9% of the respondents had “positive” or “relatively positive” viewpoints about the production of antibiotic-free chicken. The results also indicated that there were a significant (p < 0.05 positive relationship between the attitude of  production of antibiotic-free chicken with the education level, job satisfaction, second job as well as having technical supervisor. Moreover, a significant (p < 0.01 positive relationship was observed between the participation in training courses related to the production of antibiotic-free chicken and the viewpoint of studied broiler producers. On the other hand, no significant correlation was observed between the “viewpoint of chicken producers” and the variables such as: “age”, “job background”, “frequency of progeny”, “production/non-production of antibiotic-free chicken”, “consumption/non-consumption of antibiotic-free chicken” and “knowledge on breeding the antibiotic-free chicken”.

  9. A competitive trade-off limits the selective advantage of increased antibiotic production.

    Science.gov (United States)

    Gerardin, Ylaine; Springer, Michael; Kishony, Roy

    2016-09-26

    In structured environments, antibiotic-producing microorganisms can gain a selective advantage by inhibiting nearby competing species 1 . However, despite their genetic potential 2,3 , natural isolates often make only small amounts of antibiotics, and laboratory evolution can lead to loss rather than enhancement of antibiotic production 4 . Here, we show that, due to competition with antibiotic-resistant cheater cells, increased levels of antibiotic production can actually decrease the selective advantage to producers. Competing fluorescently labelled Escherichia coli colicin producers with non-producing resistant and sensitive strains on solid media, we found that although producer colonies can greatly benefit from the inhibition of nearby sensitive colonies, this benefit is shared with resistant colonies growing in their vicinity. A simple model, which accounts for such local competitive and inhibitory interactions, suggests that the advantage of producers varies non-monotonically with the amount of production. Indeed, experimentally varying the amount of production shows a peak in selection for producers, reflecting a trade-off between benefit gained by inhibiting sensitive competitors and loss due to an increased contribution to resistant cheater colonies. These results help explain the low level of antibiotic production observed for natural species and can help direct laboratory evolution experiments selecting for increased or novel production of antibiotics.

  10. Dalton Highway 9 to 11 Mile expedient resistivity permafrost investigation.

    Science.gov (United States)

    2014-01-01

    This project performed capacitive coupled resistivity surveys over a roadway reconstruction project in Interior Alaska, for the determination of permafrost extent. The : objective was to ascertain the ability of an expedient earth resistivity survey ...

  11. Evaluation of Expedient Surfaces for Remote Piloted Aircraft

    Science.gov (United States)

    2017-12-01

    ER D C/ G SL T R- 17 -2 7 Rapid Airfield Damage Recovery Program Evaluation of Expedient Surfaces for Remote Piloted Aircraft G eo te...Recovery Program ERDC/GSL TR-17-27 December 2017 Evaluation of Expedient Surfaces for Remote Piloted Aircraft Lyan Garcia and Timothy W. Rushing...flooring. This report describes the evaluation of four commercially available airfield matting systems that were investigated to determine their

  12. Termite usage associated with antibiotic therapy: enhancement of aminoglycoside antibiotic activity by natural products of Nasutitermes corniger (Motschulsky 1855

    Directory of Open Access Journals (Sweden)

    Almeida-Filho Geraldo G

    2009-09-01

    Full Text Available Abstract Background Several species from Insecta are used as remedies. Among these species, the termite Nasutitermes corniger is commonly used in traditional medicine in Northeast Brazil. The present work tests the modifying antibiotic activity of Nasutitermes corniger, a termite used in folk medicine in Northeastern region of Brazil. Methods Chlorpromazine and decocts of N. corniger were collected from two different plant species used in the traditional medicine were tested for their antimicrobial activity against strains of Escherichia coli resistant to aminoglycosides. The growth of two bacterial strains of E. coli was tested using decocts and chlorpromazine alone or associeted with aminogycosides. Results The MIC and MBC values were ≥1024 μg/ml for both strains of E. coli assayed. A significant synergism was observed between both decocts and chlorpromazine when assyed with neomycin. This synergism with neomycin indicates the involvement of an efflux system in the resistance to this aminoglycoside. Conclusion Therefore it is suggested that natural products from N. corniger could be used as a source of zoo-derived natural products with modifying antibiotic activity to aminoglycosides, being a new weapon against the bacterial resistance to antibiotics.

  13. Expedient protocol for solid-phase synthesis of secondary and tertiary amines

    DEFF Research Database (Denmark)

    Olsen, Christian A; Witt, Matthias; Jaroszewski, Jerzy W

    2004-01-01

    [reaction: see text] An expedient solid-phase synthetic approach to secondary and tertiary amines was developed. The protocol employs conversion of resin-bound amino alcohols to the corresponding iodides, followed by iodide displacement with primary or secondary amines or with unprotected amino...... alcohols. This two-step procedure, affording products in good to excellent yields, is suitable for solid-phase synthesis of polyamines....

  14. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Science.gov (United States)

    2010-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological product. (a) If a determination is made pursuant to § 1.750 that a patent for a human drug, antibiotic...

  15. The transport of antibiotic resistance genes and residues in groundwater near swine production facilities

    Science.gov (United States)

    Lin, Y. F.; Yannarell, A. C.; Mackie, R. I.; Krapac, I. G.; Chee-Sanford, J. S.; Koike, S.

    2008-12-01

    The use of antibiotics at concentrated animal feeding operations (CAFOs) for disease prevention, disease treatment, and growth promotion can contribute to the spread of antibiotic compounds, their breakdown products, and antibiotic resistant bacteria and/or the genes that confer resistance. In addition, constitutive use of antibiotics at sub-therapeutic levels can select for antibiotic resistance among the bacteria that inhabit animal intestinal tracts, onsite manure treatment facilities, and any environments receiving significant inputs of manure (e.g. through waste lagoon leakage or fertilizer amendments to farm soils). If the antibiotic resistant organisms persist in these new environments, or if they participate in genetic exchanges with the native microflora, then CAFOs may constitute a significant reservoir for the spread of antibiotic resistance to the environment at large. Our results have demonstrated that leakage from waste treatment lagoons can influence the presence and persistence of tetracycline resistance genes in the shallow aquifer adjacent to swine CAFOs, and molecular phylogeny allowed us to distinguish "native" tetracycline resistance genes in control groundwater wells from manure-associated genes introduced from the lagoon. We have also been able to detect the presence of erythromycin resistance genes in CAFO surface and groundwater even though erythromycin is strictly reserved for use in humans and thus is not utilized at any of these sites. Ongoing research, including modeling of particle transport in groundwater, will help to determine the potential spatial and temporal extent of CAFO-derived antibiotic resistance.

  16. Alternatives to antibiotics: a symposium on the challenges and solutions for animal production.

    Science.gov (United States)

    Seal, Bruce S; Lillehoj, Hyun S; Donovan, David M; Gay, Cyril G

    2013-06-01

    Antibiotics are one of the most important medical discoveries of the 20th century and will remain an essential tool for treating animal and human diseases in the 21st century. However, antibiotic resistance among bacterial pathogens and concerns over their extensive use in food animals has garnered global interest in limiting antibiotic use in animal agriculture. Yet, limiting the availability of medical interventions to prevent and control animal diseases on the farm will directly impact global food security and safety as well as animal and human health. Insufficient attention has been given to the scientific breakthroughs and novel technologies that provide alternatives to antibiotics. The objectives of the symposium 'Alternatives to Antibiotics' were to highlight promising research results and novel technologies that could potentially lead to alternatives to conventional antibiotics, and assess challenges associated with their commercialization, and provide actionable strategies to support development of alternative antimicrobials. The symposium focused on the latest scientific breakthroughs and technologies that could provide new options and alternative strategies for preventing and treating diseases of animals. Some of these new technologies have direct applications as medical interventions for human health, but the focus of the symposium was animal production, animal health and food safety during food-animal production. Five subject areas were explored in detail through scientific presentations and expert panel discussions, including: (1) alternatives to antibiotics, lessons from nature; (2) immune modulation approaches to enhance disease resistance and to treat animal diseases; (3) gut microbiome and immune development, health and diseases; (4) alternatives to antibiotics for animal production; and (5) regulatory pathways to enable the licensure of alternatives to antibiotics.

  17. Suppression of methanogenesis for hydrogen production in single-chamber microbial electrolysis cells using various antibiotics.

    Science.gov (United States)

    Catal, Tunc; Lesnik, Keaton Larson; Liu, Hong

    2015-01-01

    Methanogens can utilize the hydrogen produced in microbial electrolysis cells (MECs), thereby decreasing the hydrogen generation efficiency. However, various antibiotics have previously been shown to inhibit methanogenesis. In the present study antibiotics, including neomycin sulfate, 2-bromoethane sulfonate, 2-chloroethane sulfonate, 8-aza-hypoxanthine, were examined to determine if hydrogen production could be improved through inhibition of methanogenesis but not hydrogen production in MECs. 1.1mM neomycin sulfate inhibited both methane and hydrogen production while 2-chloroethane sulfonate (20mM), 2-bromoethane sulfonate (20mM), and 8-aza-hypoxanthine (3.6mM) can inhibited methane generation and with concurrent increases in hydrogen production. Our results indicated that adding select antibiotics to the mixed species community in MECs could be a suitable method to enhance hydrogen production efficiency. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Occurrence of antibiotics and their impacts to primary productivity in fishponds around Tai Lake, China.

    Science.gov (United States)

    Song, Chao; Zhang, Cong; Fan, Limin; Qiu, Liping; Wu, Wei; Meng, Shunlong; Hu, Gengdong; Kamira, Barry; Chen, Jiazhang

    2016-10-01

    Antibiotics are widely used to improve the health and yields of farmed animals, including fish, but their use is accompanied by undesirable ecological effects. Relatively little is known about the water-body burden of antibiotics and their influence on primary productivity in aquaculture ecosystem. In this study, antibiotics usage within 24 fishponds, covering 4 areas, sampled 5 times, and having 5 fish species, was investigated surrounding Tai Lake in China. The study analyzed 15 antibiotics (including 5 sulfonamides, 2 quinolones, 3 β-lactams, 3 tetracyclines, 1 amphenicol, and 1 macrolide), and all of them were detected in water samples, with a detection frequency of 2-60%. Sulfonamides were the most prevalent, and concentrations of sulfamethoxazole, sulfamonomethoxine, and florfenicol being over 2000 ng L(-1) in some samples, while the other antibiotics levels ranged from ND (no detection) to 551.18 ng L(-1). Significant differences were observed in antibiotic burden among different regions for total antibiotics, sulfonamides, quinolones, and amphenicols; among time points for quinolones, β-lactams, and tetracyclines; and among species for quinolones and macrolides. Furthermore, basing on the risk quotient (RQ) method, the assessment revealed that florfenicol was of highest risk to algae with RQ values exceeding 0.1, while macrolide erythromycin posed the second highest risk. The partial correlation coefficient between total antibiotics and chlorophyll (a) was -0.035 that clearly indicated total antibiotics were detrimental to green algae growth, while the nutrient input and other physical - chemical factors were much more beneficial. Overall, holistic far-reaching measures of antibiotics control are recommended to preserve aquaculture ecosystem health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. MUTATION ON Bacillus subtilis BAC4 USING ACRIDINE ORANGE AS AN EFFORT FOR INCREASING ANTIBIOTIC PRODUCTION

    Directory of Open Access Journals (Sweden)

    Supartono Supartono

    2010-06-01

    Full Text Available The efforts to get a new antibiotic require to be done continuously, because infection diseases still become the main health problems in Indonesia. A new local strain of Bacillus subtilis BAC4 has been known producing an antibiotic that inhibites Serratia marcescens ATCC 27117 growth. Nevertheless, the optimum conditions have not been studied seriously. The objective of this research was to conduct mutation on B. subtilis BAC4 in order to obtain a mutant cell that overproduct in producing antibiotic. The mutation process was performed by using acridine orange of 1 g.L-1 randomly at various volumes. The production of antibiotic was conducted using batch fermentation and antibiotic assay was performed with agar absorption method using S.  marcescens ATCC 27117 as bacteria assay. Research result provided a B. subtilis M10 mutant with overproduction of antibiotic. Characterization of B. subtilis M10 mutant showed that the mutant cell has size of (0.5-1.0 µm x (1.85-2.5 µm; spore has the form of ellipse with thick wavy wall, positive reaction for catalase, and forming acid from glucose and xylose.   Keywords: mutant, Bacillus, acridin, and antibiotics

  20. Identification and manipulation of the pleuromutilin gene cluster from Clitopilus passeckerianus for increased rapid antibiotic production

    Science.gov (United States)

    Bailey, Andy M.; Alberti, Fabrizio; Kilaru, Sreedhar; Collins, Catherine M.; de Mattos-Shipley, Kate; Hartley, Amanda J.; Hayes, Patrick; Griffin, Alison; Lazarus, Colin M.; Cox, Russell J.; Willis, Christine L.; O'Dwyer, Karen; Spence, David W.; Foster, Gary D.

    2016-05-01

    Semi-synthetic derivatives of the tricyclic diterpene antibiotic pleuromutilin from the basidiomycete Clitopilus passeckerianus are important in combatting bacterial infections in human and veterinary medicine. These compounds belong to the only new class of antibiotics for human applications, with novel mode of action and lack of cross-resistance, representing a class with great potential. Basidiomycete fungi, being dikaryotic, are not generally amenable to strain improvement. We report identification of the seven-gene pleuromutilin gene cluster and verify that using various targeted approaches aimed at increasing antibiotic production in C. passeckerianus, no improvement in yield was achieved. The seven-gene pleuromutilin cluster was reconstructed within Aspergillus oryzae giving production of pleuromutilin in an ascomycete, with a significant increase (2106%) in production. This is the first gene cluster from a basidiomycete to be successfully expressed in an ascomycete, and paves the way for the exploitation of a metabolically rich but traditionally overlooked group of fungi.

  1. Enabling Passive Immunization as an Alternative to Antibiotics for Controlling Enteric Infections in Production Animals

    DEFF Research Database (Denmark)

    Heegaard, Peter M. H.; Hald, Birthe; Madsen, M.

    . To control enteric infections by passive immunization a bolus of immunoglobulin may simply be administered orally. For this to work, large amounts of active immunoglobulins are needed. To be a real alternative to antibiotics the price of the immunoglobulin product needs to be low. We combined an efficient......Enteric infections cause major problems in most intensive animal production sectors, including poultry, pigs and cattle, leading to disease, reduced production and compromised welfare. In addition some of these infections are zoonotic, and they are to a large extent responsible for the continued...... massive use of antibiotics in food animals. Thus there is a pressing need for economically feasible, efficient, non-antibiotics based means for controlling the problem. Passive immunization has been known for decades as an efficient way of endowing humans or animals with short-term (weeks) immunity...

  2. Reproducible and expedient rice regeneration system using in vitro ...

    African Journals Online (AJOL)

    Yomi

    2012-01-03

    Jan 3, 2012 ... Inevitable prerequisite for expedient regeneration in rice is the selection of totipotent explant and developing an apposite combination of growth hormones. Here, we reported a reproducible regeneration protocol in which basal segments of the stem of the in vitro grown rice plants were used as ex-plant.

  3. Two expedient 'one-pot'methods for synthesis of -aryl- ...

    Indian Academy of Sciences (India)

    Keywords. -aryl--mercaptoketones; anhydrous potassium carbonate; amberlyst-15; chalcones; thia-Michael addition. Abstract. Two expedient one-pot methods have been developed for synthesis of -aryl--mercaptoketones using acetophenones, benzaldehydes and thiols as starting materials. The methods involve ...

  4. Reproducible and expedient rice regeneration system using in vitro ...

    African Journals Online (AJOL)

    Inevitable prerequisite for expedient regeneration in rice is the selection of totipotent explant and developing an apposite combination of growth hormones. Here, we reported a reproducible regeneration protocol in which basal segments of the stem of the in vitro grown rice plants were used as ex-plant. Using the protocol ...

  5. Expediency of Study of the Scientists' Biographies in Physics Course

    Science.gov (United States)

    Korsun, Igor

    2017-01-01

    The aim of this article is a justification of the expediency of study of the scientists' biographies in physics course. Study of the biographic materials is one of the ways of motivation of learning and development of morality, humanity, internationalism. The selection criteria of biographic material have been allocated and method of study of the…

  6. Prevalence of veterinary antibiotics and antibiotic-resistant Escherichia coli in the surface water of a livestock production region in northern China.

    Science.gov (United States)

    Zhang, Xuelian; Li, Yanxia; Liu, Bei; Wang, Jing; Feng, Chenghong; Gao, Min; Wang, Lina

    2014-01-01

    This study investigated the occurrence of 12 veterinary antibiotics (VAs) and the susceptibility of Escherichia coli (E. coli) in a rural water system that was affected by livestock production in northern China. Each of the surveyed sites was determined with at least eight antibiotics with maximum concentration of up to 450 ng L(-1). The use of VAs in livestock farming probably was a primary source of antibiotics in the rivers. Increasing total antibiotics were measured from up- to mid- and downstream in the two tributaries. Eighty-eight percent of the 218 E. coli isolates that were derived from the study area exhibited, in total, 48 resistance profiles against the eight examined drugs. Significant correlations were found among the resistance rates of sulfamethoxazole-trimethoprim, chloromycetin and ampicillin as well as between tetracycline and chlortetracycline, suggesting a possible cross-selection for resistance among these drugs. The E. coli resistance frequency also increased from up- to midstream in the three rivers. E. coli isolates from different water systems showed varying drug numbers of resistance. No clear relationship was observed in the antibiotic resistance frequency with corresponding antibiotic concentration, indicating that the antibiotic resistance for E. coli in the aquatic environment might be affected by factors besides antibiotics. High numbers of resistant E. coli were also isolated from the conserved reservoir. These results suggest that rural surface water may become a large pool of VAs and resistant bacteria. This study contributes to current information on VAs and resistant bacteria contamination in aquatic environments particularly in areas under intensive agriculture. Moreover, this study indicates an urgent need to monitor the use of VAs in animal production, and to control the release of animal-originated antibiotics into the environment.

  7. Prevalence of Veterinary Antibiotics and Antibiotic-Resistant Escherichia coli in the Surface Water of a Livestock Production Region in Northern China

    Science.gov (United States)

    Zhang, Xuelian; Li, Yanxia; Liu, Bei; Wang, Jing; Feng, Chenghong; Gao, Min; Wang, Lina

    2014-01-01

    This study investigated the occurrence of 12 veterinary antibiotics (VAs) and the susceptibility of Escherichia coli (E. coli) in a rural water system that was affected by livestock production in northern China. Each of the surveyed sites was determined with at least eight antibiotics with maximum concentration of up to 450 ng L−1. The use of VAs in livestock farming probably was a primary source of antibiotics in the rivers. Increasing total antibiotics were measured from up- to mid- and downstream in the two tributaries. Eighty-eight percent of the 218 E. coli isolates that were derived from the study area exhibited, in total, 48 resistance profiles against the eight examined drugs. Significant correlations were found among the resistance rates of sulfamethoxazole-trimethoprim, chloromycetin and ampicillin as well as between tetracycline and chlortetracycline, suggesting a possible cross-selection for resistance among these drugs. The E. coli resistance frequency also increased from up- to midstream in the three rivers. E. coli isolates from different water systems showed varying drug numbers of resistance. No clear relationship was observed in the antibiotic resistance frequency with corresponding antibiotic concentration, indicating that the antibiotic resistance for E. coli in the aquatic environment might be affected by factors besides antibiotics. High numbers of resistant E. coli were also isolated from the conserved reservoir. These results suggest that rural surface water may become a large pool of VAs and resistant bacteria. This study contributes to current information on VAs and resistant bacteria contamination in aquatic environments particularly in areas under intensive agriculture. Moreover, this study indicates an urgent need to monitor the use of VAs in animal production, and to control the release of animal-originated antibiotics into the environment. PMID:25372873

  8. Prevalence of veterinary antibiotics and antibiotic-resistant Escherichia coli in the surface water of a livestock production region in northern China.

    Directory of Open Access Journals (Sweden)

    Xuelian Zhang

    Full Text Available This study investigated the occurrence of 12 veterinary antibiotics (VAs and the susceptibility of Escherichia coli (E. coli in a rural water system that was affected by livestock production in northern China. Each of the surveyed sites was determined with at least eight antibiotics with maximum concentration of up to 450 ng L(-1. The use of VAs in livestock farming probably was a primary source of antibiotics in the rivers. Increasing total antibiotics were measured from up- to mid- and downstream in the two tributaries. Eighty-eight percent of the 218 E. coli isolates that were derived from the study area exhibited, in total, 48 resistance profiles against the eight examined drugs. Significant correlations were found among the resistance rates of sulfamethoxazole-trimethoprim, chloromycetin and ampicillin as well as between tetracycline and chlortetracycline, suggesting a possible cross-selection for resistance among these drugs. The E. coli resistance frequency also increased from up- to midstream in the three rivers. E. coli isolates from different water systems showed varying drug numbers of resistance. No clear relationship was observed in the antibiotic resistance frequency with corresponding antibiotic concentration, indicating that the antibiotic resistance for E. coli in the aquatic environment might be affected by factors besides antibiotics. High numbers of resistant E. coli were also isolated from the conserved reservoir. These results suggest that rural surface water may become a large pool of VAs and resistant bacteria. This study contributes to current information on VAs and resistant bacteria contamination in aquatic environments particularly in areas under intensive agriculture. Moreover, this study indicates an urgent need to monitor the use of VAs in animal production, and to control the release of animal-originated antibiotics into the environment.

  9. ARS Research Review on "Recent progress in developing alternative strategies to antibiotics in poultry production"

    Science.gov (United States)

    The global animal industry needs to address the increasing regulatory restrictions on the use of antibiotic growth promoters (AGPs) in animal production. Many AGPs have already been restricted by animal farms in the European Union and soon other countries are expected to be under increasing scrutin...

  10. Chitin stimulates production of the antibiotic andrimid in a Vibrio corallilyticus strain

    DEFF Research Database (Denmark)

    Wietz, Matthias; Månsson, Maria; Gram, Lone

    2011-01-01

    per cell was twofold higher. In cultures with Artemia as live chitin model system, S2052 reached up to 108 cells ml-1, produced andrimid and showed attachment to the exoskeleton and chitinous exuviae. The metabolic focus on andrimid production with chitin indicates that the antibiotic could serve...

  11. ABC transporters from Aspergillus nidulans are involved in protection against cytotoxic agents and antibiotic production

    NARCIS (Netherlands)

    Andrade, A.C.; Nistelrooy, van J.G.M.; Peery, R.B.; Skatrud, P.L.; Waard, de M.A.

    2000-01-01

    This paper describes the characterization of atrC and atrD (ABC transporters C and D), two novel ABC transporter-encoding genes from the filamentous fungus Aspergillus nidulans, and provides evidence for the involvement of atrD in multidrug transport and antibiotic production. BLAST analysis of the

  12. Biosynthetic concepts for the production of beta-lactam antibiotics in Penicillium chrysogenum

    NARCIS (Netherlands)

    Weber, Stefan S.; Bovenberg, Roel A. L.; Driessen, Arnold J. M.

    Industrial production of beta-lactam antibiotics by the filamentous fungus Penicillium chrysogenum is based on successive classical strain improvement cycles. This review summarizes our current knowledge on the results of this classical strain improvement process, and discusses avenues to improve

  13. [Enterobacteria isolated from different pathological products and their sensitivity to antibiotics].

    Science.gov (United States)

    Idomir, Mihaela; Taus, Nicoleta; Burducea, Smaranda; Stan, Daniela; Dumitru, Laura; Drilea, Andreea; Törok, Cristina

    2002-01-01

    The objectives of the study we have enhanced have focused on identifying the etiological implication of the Enterobacteria isolated from different pathological products and determining their sensitivity to the main antibiotics. We observed that from pharyngeal exudate and sputum the Enterobacter spp. strains were isolated the most frequently while from purulent secretion, urine, puncture liquids and blood, E. coli strains were the most frequently implicated. For all the categories etiologically implicated, there were selected strains resistant to one or more of the antibiotics tested, showing once again the importance of antibiogram in the initiation and control of infections disease treatment.

  14. Production of peptide antibiotics by Bacillus sp: GU 057 indigenously isolated from saline soil

    Directory of Open Access Journals (Sweden)

    Adnan Amin

    2012-12-01

    Full Text Available A total of 112 soil samples were taken from differents areas of district D.I.Khan and Kohat (KPK Pakistan and screened for production of antibiotics against the Micrococcus luteus and Staphylococcus aureus. Widest zone of inhibition (18mm was produced by microorganism isolated from saline soil. The strain was later identified as Bacillus GU057 by standard biochemical assays. Maximum activity (18mm inhibition zone was observed against Staphylococcus aureus after 48 hours of incubation at pH 8 and 4% concentration of glucose. The antibiotic was identified by autobiography as bacitracin. The Bacillus strain GU057 was confirmed as good peptide antibiotic producer and can effectively be indulged as biocontrol agent.

  15. A turning point for natural product discovery - ESF-EMBO research conference : synthetic biology of antibiotic production

    NARCIS (Netherlands)

    Takano, Eriko; Bovenberg, Roel A. L.; Breitling, Rainer

    Synthetic Biology is in a critical phase of its development: it has finally reached the point where it can move from proof-of-principle studies to real-world applications. Secondary metabolite biosynthesis, especially the discovery and production of antibiotics, is a particularly relevant target

  16. The effect of antibiotics on associated bacterial community of stored product mites.

    Directory of Open Access Journals (Sweden)

    Jan Kopecky

    Full Text Available Bacteria are associated with the gut, fat bodies and reproductive organs of stored product mites (Acari: Astigmata. The mites are pests due to the production of allergens. Addition of antibiotics to diets can help to characterize the association between mites and bacteria.Ampicillin, neomycin and streptomycin were added to the diets of mites and the effects on mite population growth (Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae and associated bacterial community structure were assessed. Mites were treated by antibiotic supplementation (1 mg g(-1 of diet for 21 days and numbers of mites and bacterial communities were analyzed and compared to the untreated control. Bacterial quantities, determined by real-time PCR, significantly decreased in antibiotic treated specimens from 5 to 30 times in A. siro and T. putrescentiae, while no decline was observed in L. destructor. Streptomycin treatment eliminated Bartonella-like bacteria in the both A. siro and T. putrescentiae and Cardinium in T. putrescentiae. Solitalea-like bacteria proportion increased in the communities of neomycin and streptomycin treated A. siro specimens. Kocuria proportion increased in the bacterial communities of ampicillin and streptomycin treated A. siro and neomycin and streptomycin treated L. destructor.The work demonstrated the changes of mite associated bacterial community under antibiotic pressure in pests of medical importance. Pre-treatment of mites by 1 mg g(-1 antibiotic diets improved mite fitness as indicated accelerated population growth of A. siro pretreated streptomycin and neomycin and L. destructor pretreated by neomycin. All tested antibiotics supplemented to diets caused the decrease of mite growth rate in comparison to the control diet.

  17. Nature's combinatorial biosynthesis and recently engineered production of nucleoside antibiotics in Streptomyces.

    Science.gov (United States)

    Chen, Shawn; Kinney, William A; Van Lanen, Steven

    2017-04-01

    Modified nucleosides produced by Streptomyces and related actinomycetes are widely used in agriculture and medicine as antibacterial, antifungal, anticancer and antiviral agents. These specialized small-molecule metabolites are biosynthesized by complex enzymatic machineries encoded within gene clusters in the genome. The past decade has witnessed a burst of reports defining the key metabolic processes involved in the biosynthesis of several distinct families of nucleoside antibiotics. Furthermore, genome sequencing of various Streptomyces species has dramatically increased over recent years. Potential biosynthetic gene clusters for novel nucleoside antibiotics are now apparent by analysis of these genomes. Here we revisit strategies for production improvement of nucleoside antibiotics that have defined mechanisms of action, and are in clinical or agricultural use. We summarize the progress for genetically manipulating biosynthetic pathways for structural diversification of nucleoside antibiotics. Microorganism-based biosynthetic examples are provided and organized under genetic principles and metabolic engineering guidelines. We show perspectives on the future of combinatorial biosynthesis, and present a working model for discovery of novel nucleoside natural products in Streptomyces.

  18. Increasing antibiotic resistance in preservative-tolerant bacterial strains isolated from cosmetic products.

    Science.gov (United States)

    Orús, Pilar; Gomez-Perez, Laura; Leranoz, Sonia; Berlanga, Mercedes

    2015-03-01

    To ensure the microbiological quality, consumer safety and organoleptic properties of cosmetic products, manufacturers need to comply with defined standards using several preservatives and disinfectants. A drawback regarding the use of these preservatives is the possibility of generating cross-insusceptibility to other disinfectants or preservatives, as well as cross resistance to antibiotics. Therefore, the objective of this study was to understand the adaptive mechanisms of Enterobacter gergoviae, Pseudomonas putida and Burkholderia cepacia that are involved in recurrent contamination in cosmetic products containing preservatives. Diminished susceptibility to formaldehyde-donors was detected in isolates but not to other preservatives commonly used in the cosmetics industry, although increasing resistance to different antibiotics (β-lactams, quinolones, rifampicin, and tetracycline) was demonstrated in these strains when compared with the wild-type strain. The outer membrane protein modifications and efflux mechanism activities responsible for the resistance trait were evaluated. The development of antibiotic-resistant microorganisms due to the selective pressure from preservatives included in cosmetic products could be a risk for the emergence and spread of bacterial resistance in the environment. Nevertheless, the large contribution of disinfection and preservation cannot be denied in cosmetic products. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  19. Production of nanaomycin and other antibiotics by phosphate-depressed fermentation using phosphate-trapping agents.

    Science.gov (United States)

    Masuma, R; Tanaka, Y; Tanaka, H; Omura, S

    1986-11-01

    Nanaomycin production by Streptomyces rosa subsp. notoensis in complex media was inhibited by exogenously supplied inorganic phosphate. The inhibition was reversed by phosphate-trapping agents such as allophane and aluminum oxide. Under such condition nanaomycin production increased to the control level, and the phosphate content dropped down to the unsupplemented level. When allophane was added to conventional complex media containing nutrient-derived inorganic phosphate, the production of nanaomycin and several other antibiotics, which are subject to phosphate regulation, was enhanced several fold with the simultaneous reduction of free phosphate. The term "phosphate-depressed fermentation" is proposed for this technique.

  20. Antibiotic resistance modulation by natural products obtained from Nasutitermes corniger (Motschulsky, 1855) and its nest.

    Science.gov (United States)

    Chaves, Thiago P; Clementino, Elaine L C; Felismino, Delcio C; Alves, Rômulo R N; Vasconcellos, Alexandre; Coutinho, Henrique D M; Medeiros, Ana Cláudia D

    2015-07-01

    Insects and their products are included in the traditional pharmacopoeia of various ethnic groups worldwide. In the Brazilian semiarid region can be highlighted the use of the termite Nasutitermes corniger for the treatment of various diseases. This study evaluated the ethanol extract of N. corniger and its nest as an antimicrobial agent and as a modulator of bacterial resistance against multidrug strains. The Minimum Inhibitory Concentration (MIC) of the extract on Staphylococcus aureus and Escherichia coli by microdilution was determined, as well as MIC of antibiotics in the presence and absence of extract. Despite having no significant antimicrobial activity (MIC ⩾ 1000 μg mL(-1)), the extract showed additive activity to the antibiotic efficacy, significantly reducing its MIC. These results suggest that N. corniger and its nest are promising natural products for use in antimicrobial therapy.

  1. Antibiotic pollution in the Katari subcatchment of the Titicaca Lake: Major transformation products and occurrence of resistance genes.

    Science.gov (United States)

    Archundia, D; Duwig, C; Lehembre, F; Chiron, S; Morel, M-C; Prado, B; Bourdat-Deschamps, M; Vince, E; Aviles, G Flores; Martins, J M F

    2017-01-15

    An increasing number of studies pointed out the ubiquitous presence of medical residues in surface and ground water as well as in soil compartments. Not only antibiotics can be found in the environment but also their transformation products about which little information is generally available. The development of bacterial resistance to antibiotics is particularly worrying as it can lead to sanitary and health problems. Studies about the dissemination of antibiotics and associated resistances in the Bolivian Altiplano are scarce. We provide baseline information on the occurrence of Sulfamethoxazole (SMX) and Trimethoprim (TMP) antibiotics as well as on the most common human SMX transformation products (TP) and on the occurrence of sulfonamide resistance genes. The studied water and soil compartments presented high levels of antibiotic pollution. This situation was shown to be mainly linked with uncontrolled discharges of treated and untreated wastewaters, resulting on the presence of antibiotics in the Titicaca Lake. SMX TPs were detected in surface waters and on soil sampled next to the wastewater treatment plant (WWTP). SMX resistance genes sulI and sulII were widely detected in the basin hydrological network, even in areas unpolluted with antibiotics. Mechanisms of co-selection of antibiotic- and metal- resistance may be involved in the prevalence of ARG's in pristine areas with no anthropogenic activity and free of antibiotic pollution. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. [Simultaneous determination of polyether antibiotics and macrolide anthelmintics in livestock products by liquid chromatography/tandem mass spectrometry].

    Science.gov (United States)

    Yamaguchi, Mizuka; Kakimoto, Kensaku; Yamaguchi, Takahiro; Obana, Hirotaka

    2011-01-01

    A method using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous determination of polyether antibiotics and macrolide anthelmintics in livestock products. The polyether antibiotics and macrolide anthelmintics were extracted from livestock products with acetonitrile and cleaned up with dispersive solid-phase extractions and a silica gel column. The quantification limits of polyether antibiotics and macrolide anthelmintics were 0.00005-0.0005 µg/g. Except for narasin and lasalocid in bovine liver and milk, the recoveries were 70 to 117%. The relative standard deviations met the required guideline. The developed method was applied to six kinds of livestock products.

  3. Macroalgal Endophytes from the Atlantic Coast of Canada: A Potential Source of Antibiotic Natural Products?

    Directory of Open Access Journals (Sweden)

    Andrew J. Flewelling

    2013-12-01

    Full Text Available As the need for new and more effective antibiotics increases, untapped sources of biodiversity are being explored in an effort to provide lead structures for drug discovery. Endophytic fungi from marine macroalgae have been identified as a potential source of biologically active natural products, although data to support this is limited. To assess the antibiotic potential of temperate macroalgal endophytes we isolated endophytic fungi from algae collected in the Bay of Fundy, Canada and screened fungal extracts for the presence of antimicrobial compounds. A total of 79 endophytes were isolated from 7 species of red, 4 species of brown, and 3 species of green algae. Twenty of the endophytes were identified to the genus or species level, with the remaining isolates designated codes according to their morphology. Bioactivity screening assays performed on extracts of the fermentation broths and mycelia of the isolates revealed that 43 endophytes exhibited antibacterial activity, with 32 displaying antifungal activity. Endophytic fungi from Bay of Fundy macroalgae therefore represent a significant source of antibiotic natural products and warrant further detailed investigation.

  4. BIOCIDAL PRODUCTS – IMPLICATIONS OF THEIR USAGE IN THE ANTIBIOTIC RESISTANCE INITIATION

    Directory of Open Access Journals (Sweden)

    Mariana Dumitrache

    2016-12-01

    Full Text Available Biocidal products are necessary in our lives in order to protect us against pathogenic microorganisms. But their use must be subject to a strict regulation because their harmful potential on human and animal health and environment is huge. Biocidal products must be authorized by a competent authority before placing them on the market and all active substances from their composition must be tested and certified to ensure they are in compliance with regulatory requirements in the field. Also biocides, with antimicrobials, may be involved in causing the phenomenon of antibiotic resistance. Their misuse can lead to the emergence of resistant organisms, through mechanisms similar to those that appear in incorrect treatment with antibiotics. We should, therefore, be aware of this aspect particularly important to prevent unwanted effects of cross resistance to antibiotics and biocides. The more so as, lately, there are pulled many alarm signals about the fact that, in a very short time, mankind is in danger of remaining without the main arsenal for fighting harmful microorganisms.

  5. Chloroform extract of turmeric inhibits biofilm formation, EPS production and motility in antibiotic resistant bacteria.

    Science.gov (United States)

    Hayat, Sumreen; Sabri, Anjum N; McHugh, Timothy D

    2018-01-15

    In the form of biofilms, bacteria exhibit more resistance to antibiotics. Biofilm formers can withstand severe conditions and the host's defense system. Therefore, it is necessary to search for effective biofilm inhibitors. In this study, we investigated the effect of a chloroform extract of turmeric on biofilm formation against antibiotic resistant bacteria. The extract exhibited its antibiofilm effect by altering adherence, motility, extracellular polymeric substance (EPS) production and cell surface hydrophobicity; important attributes of biofilm formation. Cell attachment assays indicated that a chloroform extract resulted in a 38.9-60.2% inhibition of cell adherence to a polystyrene surface, and a 44.5-58.3% inhibition to a glass surface. Static biofilm formation assays indicated that a chloroform extract resulted in a 23-74.5% reduction in biofilm formation. The chloroform extract inhibited flagella-directed swarming and swimming motility and pilus-directed twitching motility in a dose-dependent manner. In addition to repression of motility, a chloroform extract also significantly (p extract, as compared with control cells. The presence of the extract also significantly (p extract. Gas chromatography mass spectrometry (GC-MS) analysis indicated the presence of many phytochemical constituents, mainly sesquiterpenes and fatty acid groups. These results clearly suggested that turmeric could affect multiple cellular activities in biofilm formers exhibiting antibiotic resistance by modulating adherence, EPS production, motility and surface hydrophobicity.

  6. Games of life and death: antibiotic resistance and production through the lens of evolutionary game theory.

    Science.gov (United States)

    Conlin, Peter L; Chandler, Josephine R; Kerr, Benjamin

    2014-10-01

    In this review, we demonstrate how game theory can be a useful first step in modeling and understanding interactions among bacteria that produce and resist antibiotics. We introduce the basic features of evolutionary game theory and explore model microbial systems that correspond to some classical games. Each game discussed defines a different category of social interaction with different resulting population dynamics (exclusion, coexistence, bistability, cycling). We then explore how the framework can be extended to incorporate some of the complexity of natural microbial communities. Overall, the game theoretical perspective helps to guide our expectations about the evolution of some forms of antibiotic resistance and production because it makes clear the precise nature of social interaction in this context. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. 60Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    Science.gov (United States)

    Tsuji, K.; Kane, M. P.; Rahn, P. D.; Steindler, K. A.

    Effects of 60Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 × 10 -15 assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of the following antibiotics and steroids were developed. They were: dihydrostreptomycin, neomycin, novobiocin, penicillin G, hydrocortisone acetate, hydrocortisone sodium succinate, and prednisolone. The rates of degradation and radiolytic degradation schemes for the majority of these compounds were elucidated. Formation of new compounds was not observed in these antibiotics and steroids upon 60Co irradiation. The compounds that increased by irradiation were inherently present in commercially available non-irradiated lots and/or can easily be formed by either acidic, basic, or thermal treatment.

  8. /sup 60/Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, K.; Kane, M.P.; Rahn, P.D.; Steindler, K.A. (Upjohn Co., Kalamazoo, MI (USA))

    1981-01-01

    Effects of /sup 60/Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 x 10/sup -15/ assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of several of the antibiotics and steroids were developed. The rates of degradation and radiolytic degradation schemes for the majority of the compounds were elucidated.

  9. Prevalence and antibiotic resistance of Salmonella spp. in meat products, meat preparations and minced meat

    Science.gov (United States)

    Rašeta, M.; Mrdović, B.; Janković, V.; Bečkei, Z.; Lakićević, B.; Vidanović, D.; Polaček, V.

    2017-09-01

    This study aimed to determine Salmonella spp. prevalence in meat products, meat preparations and minced meat. Over a period of three years, a total of 300 samples were taken (100 RTE meat products, 100 meat preparations and 100 minced meat) and examined for the presence of Salmonella spp. Sampling was carried out at the warehouses of the food manufacturers. Salmonella spp. were not detected in RTE meat products, while 7% of semi-finished meat products (fresh sausages, grill meat formed and unformed) contained Salmonella, as did 18% of minced meats (minced pork II category, minced beef II category, mixed minced meat). The 25 Salmonella isolates obtained were examined for antibiotic resistance by the disk diffusion test, according to the NCCLS and CLSI guidelines. Isolates showed resistance to ampicillin and nalidixic acid (80%), tetracycline (72%), cefotaxime/clavulanic acid (48%), but not to gentamicin (8%) or trimethoprim/sulfamethoxazole (0%).

  10. Production of novel antibiotics zeamines through optimizing Dickeya zeae fermentation conditions.

    Science.gov (United States)

    Liao, Lisheng; Cheng, Yingying; Liu, Shiyin; Zhou, Jianuan; An, Shuwen; Lv, Mingfa; Chen, Yufan; Gu, Yanfang; Chen, Shaohua; Zhang, Lian-Hui

    2014-01-01

    Dickeya zeae strain EC1 was recently shown to produce a new type of phytotoxins designated as zeamine and zeamine II, which are potent wide-spectrum antibiotics against Gram-positive and Gram-negative bacterial pathogens, suggesting their promising potential as clinical medicines. In this study, the optimized medium composition and culture conditions for biosynthesis of novel antibiotics zeamines have been established by using response surface methodology, largely increasing the yield of zeamines from original about 7.35 µg · mL(-1) in minimal medium to about 150 µg · mL(-1) in LS5 medium. The study identified the major factors contributing to zeamines production, which include nitrate, sucrose, asparaginate, mineral elements Mg2+ and K+, and optimized amount of phosphate. In addition, the results showed that overexpression of zmsK in D. zeae strain EC1 could further increase zeamines yield to about 180 µg · mL(-1) in LS5 medium. The findings from this study could facilitate further characterization and utilization of these two novel antibiotics, and also provide useful clues for understanding the regulatory mechanisms that govern D. zeae virulence.

  11. Production of novel antibiotics zeamines through optimizing Dickeya zeae fermentation conditions.

    Directory of Open Access Journals (Sweden)

    Lisheng Liao

    Full Text Available Dickeya zeae strain EC1 was recently shown to produce a new type of phytotoxins designated as zeamine and zeamine II, which are potent wide-spectrum antibiotics against Gram-positive and Gram-negative bacterial pathogens, suggesting their promising potential as clinical medicines. In this study, the optimized medium composition and culture conditions for biosynthesis of novel antibiotics zeamines have been established by using response surface methodology, largely increasing the yield of zeamines from original about 7.35 µg · mL(-1 in minimal medium to about 150 µg · mL(-1 in LS5 medium. The study identified the major factors contributing to zeamines production, which include nitrate, sucrose, asparaginate, mineral elements Mg2+ and K+, and optimized amount of phosphate. In addition, the results showed that overexpression of zmsK in D. zeae strain EC1 could further increase zeamines yield to about 180 µg · mL(-1 in LS5 medium. The findings from this study could facilitate further characterization and utilization of these two novel antibiotics, and also provide useful clues for understanding the regulatory mechanisms that govern D. zeae virulence.

  12. Antibiotic susceptibility and antimicrobial activity of autochthonous starter cultures as safety parameters for fresh cheese production

    Directory of Open Access Journals (Sweden)

    Dora Bučan

    2013-11-01

    Full Text Available The antibiotic susceptibility and antimicrobial activity, as food safety parameters important for application of autochthonous lactic acid bacteria (LAB, that previously satisfied technological criteria for functional starter cultures in fresh cheese production were examined. Soluble whole cell protein patterns of autochthonous LAB strains from fresh cheese, obtained by SDS-PAGE, revealed the presence of two predominant strains, which were identified as Lactobacillus fermentum A8 and Enterococcus faecium A7. These strains were not resistant and shown susceptibility to antibiotics: ampicillin, bacitracin, penicillin G, azithromycin, chloramphenicol, clarithromycin, clindamycin, spiramycin, tetracycline, streptomycin, neomycin, gentamicin, erythromycin, rifampicin and novobiocin. Lb. fermentum A8 strain displayed phenotypic resistance to vancomycin, but this resistance is intrinsic, not transferable and it is acceptable from the safety aspect. The capacity of Lb. fermentum A8 and Ec. faecium A7 to inhibit growth of test-microorganisms Listeria monocytogenes ATCC 11911, Escherichia coli 3014, Salmonella enterica serovar Typhimurium FP1 and Staphylococcus aureus 3048, was also analysed. According to obtained results, Lb. fermentum A8 and Ec. faecium A7 are safe from the aspect of spreading antibiotic resistance and could be useful as bioprotective cultures that inhibit common bacterial food contaminants, including L. monocytogenes.

  13. Determination of fibrin glue with antibiotics on collagen production in colon anastomosis

    Directory of Open Access Journals (Sweden)

    Stanojković Zoran

    2008-01-01

    Full Text Available Background/Aim. Fibrin glue is used as a matrix for local application of antibiotics. The aim of this study was to determine whether application of fibrin glue in combination with antibiotics can strengthen collagen production, prevent dehiscence of colon anastomoses due to infection, and reduce frequency of mortality and morbidity comparing to the control group and the group with fibrin glue application. Methods. The adult male Wistar rats divided into three groups were used in the experiment. The group 1 was the control one (after partial colon resection, colonic anastomoses performed were not treated, while to the group 2 and the group 3 were applied fibrin glue and fibrin glue with antibiotics (clindamycin and ceftriaxon on the site of anastomoses, respectively. Quality of colonic anastomoses were estimated by means of determination of collagen (L-hydroxyproline amount in the collon wall with anastomoses and histological analysis of this colon segment using light and electronic microscope on the days 5, 7 and 13 postoperatively. Results. The highest morbidity rate was registered in the group 1 (30%, then in the group 2 (13.3% and the lowest one in the group 3 (3.33%; p < 0,05 vs group 1. Mortality rate was significantly higher in the group 1 than in the group 3 (20% and 0%, respectively; p < 0,05. In the postoperative course, the highest concentrations of collagen in the colon wall on the site of anastomoses, which was confirmed by both light and electronic microscopy, were found in the group 3. Conclusion. The application of fibrin glue with antibiotics on colon anastomoses reduces the number of dehiscence, provides good mechanical protection and shorten the time of anastomoses healing.

  14. Degradation of fluoroquinolone antibiotics by ferrate(VI): Effects of water constituents and oxidized products.

    Science.gov (United States)

    Feng, Mingbao; Wang, Xinghao; Chen, Jing; Qu, Ruijuan; Sui, Yunxia; Cizmas, Leslie; Wang, Zunyao; Sharma, Virender K

    2016-10-15

    The degradation of five fluoroquinolone (FQ) antibiotics (flumequine (FLU), enrofloxacin (ENR), norfloxacin (NOR), ofloxacin (OFL) and marbofloxacin (MAR)) by ferrate(VI) (Fe(VI)O4(2-), Fe(VI)) was examined to demonstrate the potential of this iron-based chemical oxidant to treat antibiotics in water. Experiments were conducted at different molar ratios of Fe(VI) to FQs at pH 7.0. All FQs, except FLU, were degraded within 2 min at [Fe(VI)]:[FQ] ≤ 20.0. Multiple additions of Fe(VI) improved the degradation efficiency, and provided greater degradation than a single addition of Fe(VI). The effects of anions, cations, and humic acid (HA), usually present in source waters and wastewaters, on the removal of FLU were investigated. Anions (Cl(-), SO4(2-), NO3(-), and HCO3(-)) and monovalent cations (Na(+) and K(+)) had no influence on the removal of FLU. However, multivalent cations (Ca(2+), Mg(2+), Cu(2+), and Fe(3+)) in water decreased the efficiency of FLU removal by Fe(VI). An increase in the ionic strength of the solution, and the presence of HA in the water, also decreased the percentage of FLU removed by Fe(VI). Experiments on the removal of selected FQs, present as co-existing antibiotics in pure water, river water, synthetic water and wastewater, were also conducted to demonstrate the practical application of Fe(VI) to remove the antibiotics during water treatment. The seventeen oxidized products (OPs) of FLU were identified using solid phase extraction-liquid chromatography-high-resolution mass spectrometry. The reaction pathways are proposed, and are theoretically confirmed by molecular orbital calculations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Potentiation of antibiotic activity of aminoglycosides by natural products from Cordia verbenacea DC.

    Science.gov (United States)

    Matias, Edinardo F F; Alves, Erivania F; Silva, Maria K N; Carvalho, Victoria R A; Medeiros, Cassio R; Santos, Francisco A V; Bitu, Vanessa C N; Souza, Celestina E S; Figueredo, Fernando G; Boligon, Aline A; Athayde, Margareth L; Costa, José G M; Coutinho, Henrique D M

    2016-06-01

    Medicinal plants are often the only therapeutic resource for many communities and ethnic groups. Cordia verbenacea DC., "Erva-baleeira," is one of the species of plants currently used to produce a phytotherapeutic product extracted from its leaves. The present study aimed to establish its chemical profile, antibacterial activity and resistance-modulating potential. The C. verbenacea extracts were prepared from fresh leaves using solvents as methanol and hexane. Ethyl Acetate was used for the preparation of the fraction. Phytochemical screening was carried out using HPLC-DAD for determination and quantification of the secondary metabolites present in the fractions. Antibacterial and resistance-modulation assays were performed to determine minimum inhibitory concentration (MIC) using a microdilution assay. The data were subjected to statistical analysis with two-way ANOVA and Bonferroni posttests. Results of phytochemical prospecting and HPLC analysis of the fractions were in agreement with the literature. The natural products presented moderate antibacterial activity when considering the clinical relevance of a MIC of 256 μg/mL against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, and 512 μg/mL against P. aeruginosa. However, when the fractions were combined with antibiotics we observed a synergic effect, as natural products enhanced the antibacterial effect of aminoglycosides, significantly decreasing the MIC of antibiotics at 12.5%-98.4%. We believe that the data obtained from phytochemical analysis and from antibacterial and resistance modulation assays of C. verbenacea extracts new can open perspectives in the search for new alternatives for the treatment of bacterial infections and stimulate the renewed use of antibiotics with reduced effectiveness due to resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Production of fungal antibiotics using polymeric solid supports in solid-state and liquid fermentation.

    Science.gov (United States)

    Bigelis, Ramunas; He, Haiyin; Yang, Hui Y; Chang, Li-Ping; Greenstein, Michael

    2006-10-01

    The use of inert absorbent polymeric supports for cellular attachment in solid-state fungal fermentation influenced growth, morphology, and production of bioactive secondary metabolites. Two filamentous fungi exemplified the utility of this approach to facilitate the discovery of new antimicrobial compounds. Cylindrocarpon sp. LL-Cyan426 produced pyrrocidines A and B and Acremonium sp. LL-Cyan416 produced acremonidins A-E when grown on agar bearing moist polyester-cellulose paper and generated distinctly different metabolite profiles than the conventional shaken or stationary liquid fermentations. Differences were also apparent when tenfold concentrated methanol extracts from these fermentations were tested against antibiotic-susceptible and antibiotic-resistant Gram-positive bacteria, and zones of inhibition were compared. Shaken broth cultures of Acremonium sp. or Cylindrocarpon sp. showed complex HPLC patterns, lower levels of target compounds, and high levels of unwanted compounds and medium components, while agar/solid support cultures showed significantly increased yields of pyrrocidines A and B and acremonidins A-E, respectively. This method, mixed-phase fermentation (fermentation with an inert solid support bearing liquid medium), exploited the increase in surface area available for fungal growth on the supports and the tendency of some microorganisms to adhere to solid surfaces, possibly mimicking their natural growth habits. The production of dimeric anthraquinones by Penicillium sp. LL-WF159 was investigated in liquid fermentation using various inert polymeric immobilization supports composed of polypropylene, polypropylene cellulose, polyester-cellulose, or polyurethane. This culture produced rugulosin, skyrin, flavomannin, and a new bisanthracene, WF159-A, after fermentation in the presence and absence of polymeric supports for mycelial attachment. The physical nature of the different support systems influenced culture morphology and relative

  17. ANTIBIOTIC RESISTANCE OF LACTOBACILLI STRAINS ISOLATED FROM MILK AND MILK PRODUCTS FROM MIDDLE SLOVAKIA

    Directory of Open Access Journals (Sweden)

    Lukáš Hleba

    2012-08-01

    Full Text Available The aim of this study was to determine the antibiotic susceptibility of lactobacilli strains isolated from milk and milk products from middle Slovakia. The 42 samples of milk and milk products were collected from sheep farming from middle Slovakia. MRS agar was used for this cultivation. It was done at 37 °C during 36-48 hours in CO2 box with 10 % CO2. Identification of lactobacilli strains was done by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with Biotyper software – MALDI TOF MS Biotyper. Four anitibiotics M.I.C. We used four anitibiotics M.I.C. evaluators strips for antibiotic susceptibility testing. These antibiotics were used in this experiment: erythromycin (E 256 – 0.015 µg/ml, ampicillin (AMP 256 – 0.015 µg/ml, gentamycin (CN 256 – 0.015 µg/ml and tetracycline (TE 256 – 0.015 µg/ml. We isolated 42 lactobacilli strains and identified them as Lactobacillus plantarum and Lactobacillus spp. We isolated 7 strains of Lactobacillus plantarum and 35 isolates were Lactobacillus spp. From the seven isolates of Lactobacillus plantarum 3 isolates were resistant to ampicillin (MIC 16 µg/ml in 2 isolates and MIC 12 µg/ml in one isolate and one resistant to tetracycline (MIC 16 µg/ml. From 35 isolates of Lactobacillus spp. 9 isolates were resistant to erytromycin (32 µg/ml, 10 isolates resistant to ampicillin (MIC 16 µg/ml in 4 isolates, MIC 12 µg/ml in 5 isolates and MIC 4 µg/ml in one isolate, 5 isolates resistant to tetracycline (16 µg/ml. Resistance to gentamycin was not detected. Lactobacilli isolated from milk and milk products were resistant to erytromycin (resistanece was 21.42 %, ampicillin (resistance was 30.95 % and tetracycline (resistance was 14.28 % and were sensitive in 100 % to gentamycin.

  18. Antibiotic-resistant bacteria associated with retail aquaculture products from Guangzhou, China.

    Science.gov (United States)

    Ye, Lei; Lu, Zhang; Li, Xinhui; Shi, Lei; Huang, Ying; Wang, Hua H

    2013-02-01

    This study examined the prevalence of antibiotic-resistant (ART) bacteria and representative antibiotic resistance (AR)-encoding genes associated with several aquaculture products from retail markets in Guangzhou, China. ART commensal bacteria were found in 100% of the products examined. Among 505 multidrug-resistant isolates examined, close to one-fourth contained intI and sul1 genes: 15% contained sul2 and 5% contained tet (E). Incidences of β-lactamase-encoding genes bla(TEM), bla(CMY) and erythromycin resistance determinants ermB and ermC were 4.5, 1.7, 1.3, and 0.3%, respectively. Most of the ART isolates identified from the rinse water were Aeromonas spp.; those from intestines belonged to the Enterobacteriaceae. Plasmid-associated intI and AR-encoding genes were identified in several ART isolates by Southern hybridization. Three multidrug resistance-encoding plasmids were transferred into Escherichia coli DH5 a by chemical transformation and led to acquired AR in the transformants. In addition, the AR traits in many isolates were quite stable, even in the absence of selective pressure. Further studies are needed to reveal risk factors associated with the aquaculture production chain for targeted AR mitigation.

  19. Current status and prospects for in-feed antibiotics in the different stages of pork production — A review

    Directory of Open Access Journals (Sweden)

    Junyou Li

    2017-12-01

    Full Text Available Antibiotics have long been of great benefit for people, both in the medical treatment of human disease and in animal food where they improve the growth performance and feed utilization during animal production. Antibiotics as in-feed supplements affect all stages of pork production, including the gestation, nursing, growing, and finishing stages, although the effects show stage-dependent differences. However, the use of antibiotics in animal feed has become a worldwide concern. This review describes why sub-therapeutic levels of antibiotic additives in animal feed have become an integral part of animal feeding programs for more than 70 years, particularly in pork production. It also discusses the threat of the long-term use of sub-therapeutic levels of antibiotics in pork production. In recent years, the effectiveness of in-feed antibiotics has tended to decrease. This review analyzes this change from various perspectives. First, the equipment used at pig farms has improved dramatically and is more sanitary. Worldwide, more pig farms use pig farrowing crates, gestation crates, piglet nursery crates, flooring devices, piggery ventilation and cooler systems, automatic pig feeders, piggery heating equipment, and artificial insemination systems. In addition, scientists have replaced the use of antibiotics with organic acids, fermented mash, probiotics, prebiotics, minerals, oligosaccharides, enzymes, herbs/flavors, and protein/amino acids, and have improved management and husbandry techniques. In addition, animal welfare legislation has been aimed at improving the quality of the floors and living space, ensuring that animals have permanent access to fresh water, and setting a minimum weaning age. Finally, the prospects and the possibility of replacing antibiotics in pork production are described, in line with recent research results.

  20. Biotechnological production and application of the antibiotic pimaricin: biosynthesis and its regulation.

    Science.gov (United States)

    Aparicio, Jesús F; Barreales, Eva G; Payero, Tamara D; Vicente, Cláudia M; de Pedro, Antonio; Santos-Aberturas, Javier

    2016-01-01

    Pimaricin (natamycin) is a small polyene macrolide antibiotic used worldwide. This efficient antimycotic and antiprotozoal agent, produced by several soil bacterial species of the genus Streptomyces, has found application in human therapy, in the food and beverage industries and as pesticide. It displays a broad spectrum of activity, targeting ergosterol but bearing a particular mode of action different to other polyene macrolides. The biosynthesis of this only antifungal agent with a GRAS status has been thoroughly studied, which has permitted the manipulation of producers to engineer the biosynthetic gene clusters in order to generate several analogues. Regulation of its production has been largely unveiled, constituting a model for other polyenes and setting the leads for optimizing the production of these valuable compounds. This review describes and discusses the molecular genetics, uses, mode of action, analogue generation, regulation and strategies for increasing pimaricin production yields.

  1. Enzyme production and antibiotic susceptibility of propionibacterium acnes and p. Granulosum from acne vulgaris patients and healthy persons

    OpenAIRE

    Al Hadithi, H. T. [هـ. ت. الحديثي; Khudaier, B. Y.

    1996-01-01

    Seventeen strains of Propionibacterium acnes and ten strains of P. granulosum were isolated from acne patients, in addition to ten isolates of each species from healthy persons. All strains were examined for their enzymatic activity and antibiotic susceptibility to ten antibiotics. Percentage of lipase, lecithinase and casenase production by strains of both species from acne lesions was higher than that from healthy persons in contrast to gelatinase. Haemolysin was produced almost by all stra...

  2. Broad-spectrum antibiotic activity of the arylomycin natural products is masked by natural target mutations.

    Science.gov (United States)

    Smith, Peter A; Roberts, Tucker C; Romesberg, Floyd E

    2010-11-24

    Novel classes of broad-spectrum antibiotics are needed to treat multidrug-resistant pathogens. The arylomycin class of natural products inhibits a promising antimicrobial target, type I signal peptidase (SPase), but upon initial characterization appeared to lack whole-cell activity against most pathogens. Here, we show that Staphylococcus epidermidis, which is sensitive to the arylomycins, evolves resistance via mutations in SPase and that analogous mutations are responsible for the natural resistance of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. We identify diverse bacteria lacking these mutations and demonstrate that most are sensitive to the arylomycins. The results illustrate that the arylomycins have a broad-spectrum of activity and are viable candidates for development into therapeutics. The results also raise the possibility that naturally occurring resistance may have masked other natural product scaffolds that might be developed into therapeutics. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Broad Spectrum Antibiotic Activity of the Arylomycin Natural Products is Masked by Natural Target Mutations

    Science.gov (United States)

    Smith, Peter A.; Roberts, Tucker C.; Romesberg, Floyd E.

    2010-01-01

    Summary Novel classes of broad-spectrum antibiotics are needed to treat multidrug resistant pathogens. The arylomycin class of natural products inhibits a promising antimicrobial target, type I signal peptidase (SPase), but upon initial characterization appeared to lack whole cell activity against most pathogens. Here, we show that Staphylococcus epidermidis, which is sensitive to the arylomycins, evolves resistance via mutations in SPase and that analogous mutations are responsible for the natural resistance of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. We identify diverse bacteria lacking these mutations and demonstrate that most are sensitive to the arylomycins. The results illustrate that the arylomycins have a broad-spectrum of activity and are viable candidates for development into therapeutics. The results also raise the possibility that naturally occurring resistance may have masked other natural product scaffolds that might be developed into therapeutics. PMID:21095572

  4. Multi-objective optimization of glycopeptide antibiotic production in batch and fed batch processes

    DEFF Research Database (Denmark)

    Maiti, Soumen K.; Eliasson Lantz, Anna; Bhushan, Mani

    2011-01-01

    as pareto optimal solutions. These solutions gives flexibility in evaluating the trade-offs and selecting the most suitable operating policy. Here, ε-constraint approach was used to generate the pareto solutions for two objectives: product concentration and product per unit cost of media, for batch and fed...... batch operations using process model for Amycolatopsis balhimycina, a glycopeptide antibiotic producer. This resulted in a set of several pareto optimal solutions with the two objectives ranging from (0.75gl−1, 3.97g$-1) to (0.44gl−1, 5.19g$-1) for batch and from (1.5gl−1, 5.46g$-1) to (1.1gl−1, 6.34g......$-1) for fed batch operations. One pareto solution each for batch and for fed batch mode was experimentally validated....

  5. Contribution of beta-lactamase production to the resistance of mycobacteria to beta-lactam antibiotics.

    Science.gov (United States)

    Quinting, B; Reyrat, J M; Monnaie, D; Amicosante, G; Pelicic, V; Gicquel, B; Frère, J M; Galleni, M

    1997-04-14

    Mycobacterium fallax (M. fallax) is naturally sensitive to many beta-lactam antibiotics (MIC < 2 microg/ml) and devoid of beta-lactamase activity. In this paper, we show that the production of the beta-lactamase of Mycobacterium fortuitum by M. fallax significantly increased the MIC values for good substrates of the enzyme, whereas the potency of poor substrates or transient inactivators was not modified. The rates of diffusion of beta-lactams through the mycolic acid layer were low, but for all studied compounds the half-equilibration times were such that they would only marginally affect the MIC values in the absence of beta-lactamase production. These results emphasize the importance of enzymatic degradation as a major factor in the resistance of mycobacteria to penicillins.

  6. Recombinant Streptomyces clavuligerus strain including cas2 gene production and analysis its antibiotic overproduction by bioassay

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    Zohreh Hojati

    2014-03-01

    Full Text Available Background: Streptomyces clavuligerus is one of the most important strain that produce clavulanic acid that wildly used in combination of strong but sensitive to β-lactamase antibiotics in clinics. The cas2 is one of the important genes in the biosynthesis pathway of clavulanic acid. Materials and Methods: The recombinant construct pMTcas2 which contain cas2 gene is obtained from Isfahan University. Recombinant plasmid extracts from streptomyces lividans and confirm by enzyme digestion. The streptomyces clavuligerus protoplast was prepared and transformation was done by using polyethylene glycol. Transformation was confirmed by plasmid extraction and PCR using cas2 specific primers. Finally, bioassay method was used to survey the effect of extra copy of cas2 on clavulanic acid production. Result: Plasmid extraction was initially carried out and the structure of plasmid was confirmed by digestion. The typical white colony was seen on protoplast recovery culture containing thiostrepton antibiotic and gray spores were detected after one week. Plasmid extraction was done from transformed strain and transformation was confirmed by PCR. The results of the bioassay show that amplification of the cas2 gene in multicopy plasmids resulted in a 4.1 fold increase in clavulanic acid production. Conclusion: The bioassay was done and the diameters of zone of inhibition in control and sample were compared. The results of the bioassay show that amplification of the cas2 gene in multicopy plasmids resulted in a 4.1 fold increase in clavulanic acid production. Overproduction of clavulanic acid decreases the cost of its dependent drug production.

  7. Antibiotics and sweeteners in the aquatic environment: biodegradability, formation of phototransformation products, and in vitro toxicity.

    Science.gov (United States)

    Bergheim, Marlies; Gminski, Richard; Spangenberg, Bernd; Debiak, Malgorzata; Bürkle, Alexander; Mersch-Sundermann, Volker; Kümmerer, Klaus; Gieré, Reto

    2015-11-01

    In the present study, in vitro toxicity as well as biopersistence and photopersistence of four artificial sweeteners (acesulfame, cyclamate, saccharine, and sucralose) and five antibiotics (levofloxacin, lincomycin, linezolid, marbofloxacin, and sarafloxacin) and of their phototransformation products (PTPs) were investigated. Furthermore, antibiotic activity was evaluated after UV irradiation and after exposure to inocula of a sewage treatment plant. The study reveals that most of the tested compounds and their PTPs were neither readily nor inherently biodegradable in the Organisation for Economic Co-operation and Development (OECD)-biodegradability tests. The study further demonstrates that PTPs are formed upon irradiation with an Hg lamp (UV light) and, to a lesser extent, upon irradiation with a Xe lamp (mimics sunlight). Comparing the nonirradiated with the corresponding irradiated solutions, a higher chronic toxicity against bacteria was found for the irradiated solutions of linezolid. Neither cytotoxicity nor genotoxicity was found in human cervical (HeLa) and liver (Hep-G2) cells for any of the investigated compounds or their PTPs. Antimicrobial activity of the tested fluoroquinolones was reduced after UV treatment, but it was not reduced after a 28-day exposure to inocula of a sewage treatment plant. This comparative study shows that PTPs can be formed as a result of UV treatment. The study further demonstrated that UV irradiation can be effective in reducing the antimicrobial activity of antibiotics, and consequently may help to reduce antimicrobial resistance in wastewaters. Nevertheless, the study also highlights that some PTPs may exhibit a higher ecotoxicity than the respective parent compounds. Consequently, UV treatment does not transform all micropollutants into harmless compounds and may not be a large-scale effluent treatment option.

  8. A study on device-related infections with special reference to biofilm production and antibiotic resistance

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    Monil Singhai

    2012-01-01

    Full Text Available Background: Indwelling medical devices (IMDs in critical patients are vulnerable to colonization by biofilm producing bacteria. Complex characteristics of bacterial biofilms promote antibiotic resistance, leading to the emergence of resistant device-related infections (DRI, which pose new challenges in their management. Materials and Methods : The study was done on 135 hospitalized (Intensive care units pediatric patients with IMDs (intravascular catheter, urinary catheter, and endotracheal tube to determine the device-specific infection rates. Biofilm formations were demonstrated by the tube method and by scanning electron microscopy (SEM. Bacteria in biofilms were identified by the standard conventional methods and tested for antibiotic resistance. We also detected the presence of extended spectrum β-lactamases (ESβLs, particularly, blaCTX-M, in gram-negative isolates. Results: The rates of biofilm-based catheter-related blood stream infections (CRBSI, catheter-associated urinary tract infections (CAUTI, and Ventilator Associated Pneumonia (VAP, in our study, were 10.4, 26.6, and 20%. Biofilm formation by the tube method correlated well with the SEM findings. A majority of infections were caused by Klebsiella pneumoniae followed by Staphylococcal biofilms. A high percentage (85.7%, 95% confidence interval 64.5 to 95.8% of biofilm producing bacterial isolates, causing infection, were multidrug resistant. Many biofilm producing gram-negative isolates were ESβLs producers, and a majority particularly harbored blaCTX-M, among the ESβLs genotypes. Conclusion: The incidence of resistant device-related infections, predominantly caused by biofilm producing bacteria, is rising. The tube method is an effective screening method to test biofilm production, where sophisticated microscopy facilities are not available. The varying resistance pattern of organisms isolated in our setup, emphasizes the importance of studying the pattern of infection in

  9. Limited Bacterial Diversity within a Treatment Plant Receiving Antibiotic-Containing Waste from Bulk Drug Production.

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    Nachiket P Marathe

    Full Text Available Biological treatment of waste water from bulk drug production, contaminated with high levels of fluoroquinolone antibiotics, can lead to massive enrichment of antibiotic resistant bacteria, resistance genes and associated mobile elements, as previously shown. Such strong selection may be boosted by the use of activated sludge (AS technology, where microbes that are able to thrive on the chemicals within the wastewater are reintroduced at an earlier stage of the process to further enhance degradation of incoming chemicals. The microbial community structure within such a treatment plant is, however, largely unclear. In this study, Illumina-based 16S rRNA amplicon sequencing was applied to investigate the bacterial communities of different stages from an Indian treatment plant operated by Patancheru Environment Technology Limited (PETL in Hyderabad, India. The plant receives waste water with high levels of fluoroquinolones and applies AS technology. A total of 1,019,400 sequences from samples of different stages of the treatment process were analyzed. In total 202, 303, 732, 652, 947 and 864 operational taxonomic units (OTUs were obtained at 3% distance cutoff in the equilibrator, aeration tanks 1 and 2, settling tank, secondary sludge and old sludge samples from PETL, respectively. Proteobacteria was the most dominant phyla in all samples with Gammaproteobacteria and Betaproteobacteria being the dominant classes. Alcaligenaceae and Pseudomonadaceae, bacterial families from PETL previously reported to be highly multidrug resistant, were the dominant families in aeration tank samples. Despite regular addition of human sewage (approximately 20% to uphold microbial activity, the bacterial diversity within aeration tanks from PETL was considerably lower than corresponding samples from seven, regular municipal waste water treatment plants. The strong selection pressure from antibiotics present may be one important factor in structuring the microbial

  10. Limited Bacterial Diversity within a Treatment Plant Receiving Antibiotic-Containing Waste from Bulk Drug Production.

    Science.gov (United States)

    Marathe, Nachiket P; Shetty, Sudarshan A; Shouche, Yogesh S; Larsson, D G Joakim

    2016-01-01

    Biological treatment of waste water from bulk drug production, contaminated with high levels of fluoroquinolone antibiotics, can lead to massive enrichment of antibiotic resistant bacteria, resistance genes and associated mobile elements, as previously shown. Such strong selection may be boosted by the use of activated sludge (AS) technology, where microbes that are able to thrive on the chemicals within the wastewater are reintroduced at an earlier stage of the process to further enhance degradation of incoming chemicals. The microbial community structure within such a treatment plant is, however, largely unclear. In this study, Illumina-based 16S rRNA amplicon sequencing was applied to investigate the bacterial communities of different stages from an Indian treatment plant operated by Patancheru Environment Technology Limited (PETL) in Hyderabad, India. The plant receives waste water with high levels of fluoroquinolones and applies AS technology. A total of 1,019,400 sequences from samples of different stages of the treatment process were analyzed. In total 202, 303, 732, 652, 947 and 864 operational taxonomic units (OTUs) were obtained at 3% distance cutoff in the equilibrator, aeration tanks 1 and 2, settling tank, secondary sludge and old sludge samples from PETL, respectively. Proteobacteria was the most dominant phyla in all samples with Gammaproteobacteria and Betaproteobacteria being the dominant classes. Alcaligenaceae and Pseudomonadaceae, bacterial families from PETL previously reported to be highly multidrug resistant, were the dominant families in aeration tank samples. Despite regular addition of human sewage (approximately 20%) to uphold microbial activity, the bacterial diversity within aeration tanks from PETL was considerably lower than corresponding samples from seven, regular municipal waste water treatment plants. The strong selection pressure from antibiotics present may be one important factor in structuring the microbial community in PETL

  11. A probabilistic approach to assess antibiotic resistance development risks in environmental compartments and its application to an intensive aquaculture production scenario.

    Science.gov (United States)

    Rico, Andreu; Jacobs, Rianne; Van den Brink, Paul J; Tello, Alfredo

    2017-12-01

    Estimating antibiotic pollution and antibiotic resistance development risks in environmental compartments is important to design management strategies that advance our stewardship of antibiotics. In this study we propose a modelling approach to estimate the risk of antibiotic resistance development in environmental compartments and demonstrate its application in aquaculture production systems. We modelled exposure concentrations for 12 antibiotics used in Vietnamese Pangasius catfish production using the ERA-AQUA model. Minimum selective concentration (MSC) distributions that characterize the selective pressure of antibiotics on bacterial communities were derived from the European Committee on Antimicrobial Susceptibility Testing (EUCAST) Minimum Inhibitory Concentration dataset. The antibiotic resistance development risk (RDR) for each antibiotic was calculated as the probability that the antibiotic exposure distribution exceeds the MSC distribution representing the bacterial community. RDRs in pond sediments were nearly 100% for all antibiotics. Median RDR values in pond water were high for the majority of the antibiotics, with rifampicin, levofloxacin and ampicillin having highest values. In the effluent mixing area, RDRs were low for most antibiotics, with the exception of amoxicillin, ampicillin and trimethoprim, which presented moderate risks, and rifampicin and levofloxacin, which presented high risks. The RDR provides an efficient means to benchmark multiple antibiotics and treatment regimes in the initial phase of a risk assessment with regards to their potential to develop resistance in different environmental compartments, and can be used to derive resistance threshold concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Does the Recent Growth of Aquaculture Create Antibiotic Resistance Threats Different from those Associated with Land Animal Production in Agriculture?

    Science.gov (United States)

    Done, Hansa Y; Venkatesan, Arjun K; Halden, Rolf U

    2015-05-01

    Important antibiotics in human medicine have been used for many decades in animal agriculture for growth promotion and disease treatment. Several publications have linked antibiotic resistance development and spread with animal production. Aquaculture, the newest and fastest growing food production sector, may promote similar or new resistance mechanisms. This review of 650+ papers from diverse sources examines parallels and differences between land-based agriculture of swine, beef, and poultry and aquaculture. Among three key findings was, first, that of 51 antibiotics commonly used in aquaculture and agriculture, 39 (or 76%) are also of importance in human medicine; furthermore, six classes of antibiotics commonly used in both agriculture and aquaculture are also included on the World Health Organization's (WHO) list of critically important/highly important/important antimicrobials. Second, various zoonotic pathogens isolated from meat and seafood were observed to feature resistance to multiple antibiotics on the WHO list, irrespective of their origin in either agriculture or aquaculture. Third, the data show that resistant bacteria isolated from both aquaculture and agriculture share the same resistance mechanisms, indicating that aquaculture is contributing to the same resistance issues established by terrestrial agriculture. More transparency in data collection and reporting is needed so the risks and benefits of antibiotic usage can be adequately assessed.

  13. Production of polypeptide antibiotic from Streptomyces parvulus and its antibacterial activity

    Directory of Open Access Journals (Sweden)

    Prakasham Reddy Shetty

    2014-01-01

    Full Text Available A highly potent secondary metabolite producing actinomycetes strain is isolated from marine soil sediments of Visakhapatnam sea coast, Bay of Bengal. Over all ten strains are isolated from the collected soil sediments. Among the ten actinomycetes strains the broad spectrum strain RSPSN2 was selected for molecular characterization, antibiotic production and its purification. The nucleotide sequence of the 1 rRNA gene (1261 base pairs of the most potent strain evidenced a 96% similarity with Streptomyces parvulus 1044 strain, Streptomyces parvulus NBRC 13193 and Streptomyces parvulus BY-F. From the taxonomic features, the actinomycetes isolate RSPSN2 matches with Streptomyces parvulus in the morphological, physiological and biochemical characters. Thus, it was given the suggested name Streptomyces parvulus RSPSN2. The active metabolite was extracted using ethyl acetate (1:3, v/v at pH 7.0. The separation of active ingredient and its purification was performed by using both thin layer chromatography (TLC and column chromatography (CC techniques. Spectrometric studies such as UV-visible, FTIR, and NMR and mass were performed. The antibacterial activity of pure compound was performed by cup plate method against some pathogenic bacteria including of streptomycin resistant bacteria like (Pseudomonas mirabilis. Pseudomonas putida and Bacillus cereus. In conclusion, the collected data emphasized the fact that a polypeptide antibiotic (Actinomycin D was produced by Streptomyces parvulus RSPSN2.

  14. Biochemical studies on antibiotic production from Streptomyces sp.: Taxonomy, fermentation, isolation and biological properties

    Directory of Open Access Journals (Sweden)

    Houssam M. Atta

    2015-01-01

    Full Text Available Tunicamycin is a nucleotide antibiotic which was isolated from the fermentation broth of a Streptomyces strain No. T-4. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain T-4 was identified as Streptomyces torulosus. It is active in vitro against some microbial pathogenic viz: Staphylococcus aureus, NCTC 7447; Micrococcus lutea, ATCC 9341; Bacillus subtilis, NCTC 10400; B. pumilus, NCTC; Klebsiella pneumonia, NCIMB 9111; Escherichia coli, NCTC 10416; Pseudomonas aeruginosa, ATCC 10145; Saccharomyces cerevisiae ATCC 9763; Candida albicans, IMRU 3669; Aspergillus flavus, IMI 111023; Aspergillus niger IMI 31276; Aspergillus fumigatus ATCC 16424; Fusarium oxysporum; Rhizoctonia solani; Alternaria alternata; Botrytis fabae and Penicillium chrysogenium. The production media were optimized for maximum yield of secondary metabolites. The metabolites were extracted using n-butanol (1:1, v/v at pH 7.0. The chemical structural analysis with UV, IR, and MS spectral analyses confirmed that the compound produced by Streptomyces torulosus, T-4 is tunicamycin antibiotic.

  15. New insights about antibiotic production by Pseudomonas aeruginosa: a gene expression analysis

    Science.gov (United States)

    Gionco, Bárbara; Tavares, Eliandro R.; de Oliveira, Admilton G.; Yamada-Ogatta, Sueli F.; do Carmo, Anderson O.; Pereira, Ulisses de Pádua; Chideroli, Roberta T.; Simionato, Ane S.; Navarro, Miguel O. P.; Chryssafidis, Andreas L.; Andrade, Galdino

    2017-09-01

    The bacterial resistance for antibiotics is one of the most important problems in public health and only a small number of new products are in development. Antagonistic microorganisms from soil are a promising source of new candidate molecules. Products of secondary metabolism confer adaptive advantages for their producer, in the competition for nutrients in the microbial community. The biosynthesis process of compounds with antibiotic activity is the key to optimize their production and the transcriptomic study of microorganisms is of great benefit for the discovery of these metabolic pathways. Pseudomonas aeruginosa LV strain growing in the presence of copper chloride produces a bioactive organometallic compound, which has a potent antimicrobial activity against various microorganisms. The objective of this study was to verify overexpressed genes and evaluate their relation to the organometallic biosynthesis in this microorganism. P. aeruginosa LV strain was cultured in presence and absence of copper chloride. Two methods were used for transcriptomic analysis, genome reference-guided assembly and de novo assembly. The genome referenced analysis identified nine upregulated genes when bacteria were exposed to copper chloride, while the De Novo Assembly identified twelve upregulated genes. Nineteen genes can be related to an increased microbial metabolism for the extrusion process of exceeding intracellular copper. Two important genes are related to the biosynthesis of phenazine and tetrapyrroles compounds, which can be involved in the bioremediation of intracellular copper and biosynthesis of the organometallic compound. Additional studies are being carried out to further prove the function of the described genes and relate them to the biosynthetic pathway of the organometallic compound.

  16. New Insights about Antibiotic Production by Pseudomonas aeruginosa: A Gene Expression Analysis

    Directory of Open Access Journals (Sweden)

    Bárbara Gionco

    2017-09-01

    Full Text Available The bacterial resistance for antibiotics is one of the most important problems in public health and only a small number of new products are in development. Antagonistic microorganisms from soil are a promising source of new candidate molecules. Products of secondary metabolism confer adaptive advantages for their producer, in the competition for nutrients in the microbial community. The biosynthesis process of compounds with antibiotic activity is the key to optimize their production and the transcriptomic study of microorganisms is of great benefit for the discovery of these metabolic pathways. Pseudomonas aeruginosa LV strain growing in the presence of copper chloride produces a bioactive organometallic compound, which has a potent antimicrobial activity against various microorganisms. The objective of this study was to verify overexpressed genes and evaluate their relation to the organometallic biosynthesis in this microorganism. P. aeruginosa LV strain was cultured in presence and absence of copper chloride. Two methods were used for transcriptomic analysis, genome reference-guided assembly and de novo assembly. The genome referenced analysis identified nine upregulated genes when bacteria were exposed to copper chloride, while the De Novo Assembly identified 12 upregulated genes. Nineteen genes can be related to an increased microbial metabolism for the extrusion process of exceeding intracellular copper. Two important genes are related to the biosynthesis of phenazine and tetrapyrroles compounds, which can be involved in the bioremediation of intracellular copper and we suggesting that may involve in the biosynthesis of the organometallic compound. Additional studies are being carried out to further prove the function of the described genes and relate them to the biosynthetic pathway of the organometallic compound.

  17. Anaerobic treatment of antibiotic production wastewater pretreated with enhanced hydrolysis: Simultaneous reduction of COD and ARGs.

    Science.gov (United States)

    Yi, Qizhen; Zhang, Yu; Gao, Yingxin; Tian, Zhe; Yang, Min

    2017-03-01

    The presence of high concentration antibiotics in wastewater can disturb the stability of biological wastewater treatment systems and promote generation of antibiotic resistance genes (ARGs) during the treatment. To solve this problem, a pilot system consisting of enhanced hydrolysis pretreatment and an up-flow anaerobic sludge bed (UASB) reactor in succession was constructed for treating oxytetracycline production wastewater, and the performance was evaluated in a pharmaceutical factory in comparison with a full-scale anaerobic system operated in parallel. After enhanced hydrolysis under conditions of pH 7 and 85 °C for 6 h, oxytetracycline production wastewater with an influent chemical oxygen demand (COD) of 11,086 ± 602 mg L -1 was directly introduced into the pilot UASB reactor. With the effective removal of oxytetracycline and its antibacterial potency (from 874 mg L -1 to less than 0.61 mg L -1 and from 900 mg L -1 to less than 0.84 mg L -1 , respectively) by the enhanced hydrolysis pretreatment, an average COD removal rate of 83.2%, 78.5% and 68.9% was achieved at an organic loading rate of 3.3, 4.8 and 5.9 kg COD m -3  d -1 , respectively. At the same time, the relative abundances of the total tetracycline (tet) genes and a mobile element (Class 1 integron (intI1)) in anaerobic sludge on day 96 were one order of magnitude lower than those in inoculated sludge on day 0 (P gene abundance in sludge was five times higher than the pilot-scale system (P < 0.01). The above result demonstrated that enhanced hydrolysis as a pretreatment method could enable efficient anaerobic treatment of oxytetracycline production wastewater containing high concentrations of oxytetracycline with significantly lower generation of ARGs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Prevalence, genetic diversity, and antibiotic resistance of Bacillus cereus isolated from Korean fermented soybean products.

    Science.gov (United States)

    Kim, Cheol-Woo; Cho, Seung-Hak; Kang, Suk-Ho; Park, Yong-Bae; Yoon, Mi-Hye; Lee, Jong-Bok; No, Wan-Seob; Kim, Jung-Beom

    2015-01-01

    Bacillus cereus contamination is a major food safety problem for Korean fermented soybean products, but few studies have assessed its potential to cause foodborne illness. The objectives of this study were to investigate the prevalence and characteristics of B. cereus isolated from Korean fermented soybean products. B. cereus was detected in 110 of 162 (67.9%) samples. The highest B. cereus frequency was observed in deonjang (68 of 93 samples, 73.1%) and cheonggukjang (18 of 25, 72.0%); however, nonhemolytic enterotoxin was detected only in 22 of 162 samples (13.6%). Although the tested B. cereus isolates showed diverse pulsotypes according to repetitive sequence-PCR banding patterns, they displayed similar antibiotic sensitivity spectra. The low frequency of enterotoxin detection suggests that the potential risk of B. cereus foodborne illness associated with Korean fermented soybean products is lower than generally presumed. However, considering the prevalence of B. cereus and the high content of fermented soybean products in the Korean diet, it is necessary to constantly monitor the level of contamination with B. cereus and its toxins in such Korean food products. © 2014 Institute of Food Technologists®

  19. Screening of antibiotics and chemical analysis of penicillin residue in fresh milk and traditional dairy products in Oyo state, Nigeria.

    Science.gov (United States)

    Olatoye, Isaac Olufemi; Daniel, Oluwayemisi Folashade; Ishola, Sunday Ayobami

    2016-09-01

    There are global public health and economic concerns on chemical residues in food of animal origin. The use of antibiotics in dairy cattle for the treatment of diseases such as mastitis has contributed to the presence of residues in dairy products. Penicillin residues as low as 1 ppb can lead to allergic reactions and shift of resistance patterns in microbial population as well as interfere with the processing of several dairy products. Antibiotic monitoring is an essential quality control measure in safe milk production. This study was aimed at determining antibiotic residue contamination and the level of penicillin in dairy products from Fulani cattle herds in Oyo State. The presence of antibiotic residues in 328 samples of fresh milk, 180 local cheese (wara), and 90 fermented milk (nono) from Southwest, Nigeria were determined using Premi® test kit (R-Biopharm AG, Germany) followed by high-performance liquid chromatography analysis of penicillin-G residue. Antibiotic residues were obtained in 40.8%, 24.4% and 62.3% fresh milk, wara and nono, respectively. Penicillin-G residue was also detected in 41.1% fresh milk, 40.2% nono and 24.4% wara at mean concentrations of 15.22±0.61, 8.24±0.50 and 7.6±0.60 μg/L with 39.3%, 36.7% and 21.1%, respectively, containing penicillin residue above recommended Codex maximum residue limit (MRL) of 5 μg/L in dairy. There was no significant difference between the mean penicillin residues in all the dairy products in this study. The results are of food safety concern since the bulk of the samples and substantial quantities of dairy products in Oyo state contained violative levels of antibiotic residues including penicillin residues in concentrations above the MRL. This could be due to indiscriminate and unregulated administration of antibiotics to dairy cattle. Regulatory control of antibiotic use, rapid screening of milk and dairy farmers' extension education on alternatives to antibiotic prophylaxis, veterinary prescriptions

  20. Screening of antibiotics and chemical analysis of penicillin residue in fresh milk and traditional dairy products in Oyo state, Nigeria

    Directory of Open Access Journals (Sweden)

    Isaac Olufemi Olatoye

    2016-09-01

    Full Text Available Background and Aim: There are global public health and economic concerns on chemical residues in food of animal origin. The use of antibiotics in dairy cattle for the treatment of diseases such as mastitis has contributed to the presence of residues in dairy products. Penicillin residues as low as 1 ppb can lead to allergic reactions and shift of resistance patterns in microbial population as well as interfere with the processing of several dairy products. Antibiotic monitoring is an essential quality control measure in safe milk production. This study was aimed at determining antibiotic residue contamination and the level of penicillin in dairy products from Fulani cattle herds in Oyo State. Materials and Methods: The presence of antibiotic residues in 328 samples of fresh milk, 180 local cheese (wara, and 90 fermented milk (nono from Southwest, Nigeria were determined using Premi® test kit (R-Biopharm AG, Germany followed by high-performance liquid chromatography analysis of penicillin-G residue. Results: Antibiotic residues were obtained in 40.8%, 24.4% and 62.3% fresh milk, wara and nono, respectively. Penicillin-G residue was also detected in 41.1% fresh milk, 40.2% nono and 24.4% wara at mean concentrations of 15.22±0.61, 8.24±0.50 and 7.6±0.60 μg/L with 39.3%, 36.7% and 21.1%, respectively, containing penicillin residue above recommended Codex maximum residue limit (MRL of 5 μg/L in dairy. There was no significant difference between the mean penicillin residues in all the dairy products in this study. Conclusion: The results are of food safety concern since the bulk of the samples and substantial quantities of dairy products in Oyo state contained violative levels of antibiotic residues including penicillin residues in concentrations above the MRL. This could be due to indiscriminate and unregulated administration of antibiotics to dairy cattle. Regulatory control of antibiotic use, rapid screening of milk and dairy farmers

  1. Decreased antibiotic susceptibility and enhanced probiotic production potential of goat milk fermented curd in comparison with cow and buffalo milk

    Directory of Open Access Journals (Sweden)

    Jyoti Lakhanpal

    2017-07-01

    Full Text Available The present study was carried out to characterize and compare the production potential and antibiotic susceptibility of probiotics isolated from goat, cow and buffalo milk. The probiotics isolated from milk fermented curd were compared with regard to their number, morphology, gram staining, motility, bile salt tolerance, pH-resistance, catalase activity, oxidase production and antibiotic resistance. We demonstrated that the probiotics isolated from milk fermented curd of all three species were gram positive, motile, catalase negative, and oxidase negative and were able to produce lactic acid. Further, we observed that buffalo milk is more potent in forming curd with the highest count of probiotics per ml (3.53 × 10!5 as compared to cow (5.8 × 10!6 and goat milk (7×10!7; moreover, goat milk bacterial isolates were more tolerant to acidic pH but were less bile-salt tolerant than cow milk. Also, probiotics isolated from goat milk curd were more resistant to antibiotics (resistant to 12 out of 15 screened antibiotics than those from cow and buffalo milk (resistant to 8-9 antibiotics. This report shows that goat milk fermented products possess the highest antibacterial potential and are highly acid-tolerant.

  2. Conformational control of the bacterial Clp protease by natural product antibiotics.

    Science.gov (United States)

    Malik, I T; Brötz-Oesterhelt, H

    2017-07-06

    Covering: up to 2017The bacterial Clp protease is a highly conserved and structurally versatile machine. It has gained a lot of recognition during the last decade as a novel antibacterial drug target with an unprecedented mechanism of action. Due to its complexity, there are distinct means of interfering with its natural functions and several compounds targeting this machine have been identified. In this review, we summarize the current state of knowledge about natural products deregulating Clp proteolysis, a crucial and delicate process within the cell. Among those, acyldepsipeptide antibiotics of the ADEP class (ADEPs) are characterized best. The molecular mechanism of ADEP-mediated deregulation sheds light on the inner workings of the Clp protease.

  3. Effect of prepartum dry cow antibiotic treatment in dairy heifers on udder health and milk production.

    Science.gov (United States)

    Sampimon, O C; De Vliegher, S; Barkema, H W; Sol, J; Lam, T J G M

    2009-09-01

    A high percentage of heifers calve with intramammary infections. One of the measures available to control intramammary infections is treatment with antibiotics before calving. In this study, the effects of prepartum treatment of nonlactating heifers with a 600-mg cloxacillin dry cow treatment on the prevalence of culture-positive milk samples at calving and 10 to 14 d in milk (DIM), the incidence of clinical mastitis, somatic cell count (SCC), and milk production during first lactation were quantified. A total of 184 heifers on 13 dairy farms were treated with antibiotics 8 to 10 wk before the expected calving date. Another 185 heifers served as untreated controls. Coagulase-negative staphylococci were the most frequently isolated group of bacteria in the treatment and control groups at calving (32 and 42%), and at 10 to 14 DIM (15 and 19%), respectively. The prevalence of minor pathogens at calving was lower in the treatment group compared with the control group (34 and 43%, respectively). Staphylococcus aureus was the most frequently isolated major pathogen in the treated and control heifers at calving (4 and 5%) and at 10 to 14 DIM (2 and 3%), respectively. The prevalence of major pathogens was lower in the treated heifers at 10 to 14 DIM compared with the control group (4 and 6%, respectively). Cumulative incidence risk of clinical mastitis during the lactation was 9 and 18% in the treatment and control groups, respectively. Treatment with cloxacillin 8 to 10 wk before calving resulted in a lower prevalence of culture-positive milk samples at calving and lower quarter milk SCC in early lactation [30,000 +/- 4,600 (standard deviation) cells/mL in treated heifers versus 40,000 +/- 4,600 cells/mL in control heifers], and was associated with lower average test-day SCC (55,000 +/- 1,400 cells/mL in treated heifers versus 71,000 +/- 1,500 cells/mL in control heifers) and lower incidence of clinical mastitis throughout lactation. The improved udder health resulted in

  4. Resistance to colistin: what is the fate for this antibiotic in pig production?

    Science.gov (United States)

    Rhouma, Mohamed; Beaudry, Francis; Letellier, Ann

    2016-08-01

    Colistin, a cationic polypeptide antibiotic, has reappeared in human medicine as a last-line treatment option for multidrug-resistant Gram-negative bacteria (MDR-GNB). Colistin is widely used in veterinary medicine for the treatment of gastrointestinal infections caused by Enterobacteriaceae. GNB resistant to colistin owing to chromosomal mutations have already been reported both in human and veterinary medicine, however several recent studies have just identified a plasmid-mediated mcr-1 gene encoding for colistin resistance in Escherichia coli colistin resistance. The discovery of a non-chromosomal mechanism of colistin resistance in E. coli has led to strong reactions in the scientific community and to concern among physicians and veterinarians. Colistin use in food animals and particularly in pig production has been singled out as responsible for the emergence of colistin resistance. The present review will focus mainly on the possible link between colistin use in pigs and the spread of colistin resistance in Enterobacteriaceae. First we demonstrate a possible link between Enterobacteriaceae resistance emergence and oral colistin pharmacokinetics/pharmacodynamics and its administration modalities in pigs. We then discuss the potential impact of colistin use in pigs on public health with respect to resistance. We believe that colistin use in pig production should be re-evaluated and its dosing and usage optimised. Moreover, the search for competitive alternatives to using colistin with swine is of paramount importance to preserve the effectiveness of this antibiotic for the treatment of MDR-GNB infections in human medicine. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  5. Fouling analysis of membrane bioreactor treating antibiotic production wastewater at different hydraulic retention times.

    Science.gov (United States)

    Yu, Dawei; Chen, Yutao; Wei, Yuansong; Wang, Jianxing; Wang, Yawei; Li, Kun

    2017-04-01

    Membrane fouling, including foulants and factors, was investigated during hydraulic retention time (HRT) optimization of a membrane bioreactor (MBR) that treated wastewater from the production of antibiotics. The results showed that HRT played an important role in membrane fouling. Trans-membrane pressure (TMP), membrane flux, and resistance were stable at -6 kPa, 76 L m(-2) h(-1) bar(-1), and 4.5 × 10(12) m(-1) when HRT was at 60, 48, and 36 h, respectively. Using Fourier transform infrared spectroscopy, foulants were identified as carbohydrates and proteins, which correlated with effluent organic matter and effluent chemical oxygen demand (COD) compounds. Therefore, membrane fouling trends would benefit from low supernatant COD (378 mg L(-1)) and a low membrane removal rate (26 %) at a HRT of 36 h. Serious membrane fouling at 72 and 24 h was related to soluble microbial products and extracellular polymeric substances in mixed liquor, respectively. Based on the TMP decrease and flux recovery after physical and chemical cleaning, irremovable fouling aggravation was related to extracellular polymeric substances' increase and soluble microbial products' decrease. According to changes in the specific oxygen uptake rate (SOUR) and mixed liquor suspended solids (MLSSs) during HRT optimization in this study, antibiotic production wastewater largely inhibited MLSS growth, which only increased from 4.5 to 5.0 g L(-1) when HRT was decreased from 72 to 24 h, but did not limit sludge activity. The results of a principal component analysis highlighted both proteins and carbohydrates in extracellular polymeric substances as the primary foulants. Membrane fouling associated with the first principal component was positively related to extracellular polymeric substances and negatively related to soluble microbial products. Principal component 2 was primarily related to proteins in the influent. Additional membrane fouling factors included biomass

  6. Production of the glycopeptide antibiotic A40926 by Nonomuraea sp ATCC 39727: influence of medium composition in batch fermentation

    DEFF Research Database (Denmark)

    Gunnarsson, Nina; Bruheim, Per; Nielsen, Jens

    2003-01-01

    Nonomuraea sp. ATCC 39727 is a novel actinomycete species and the producer of A40926, a glycopeptide antibiotic structurally similar to teichoplanin. In the present study, a defined minimal medium was designed for Nonomuraea fermentation. The influence of initial phosphate, glucose and ammonium...... concentrations on antibiotic productivity was investigated in batch fermentation and the effect of glucose limitation was studied in fed-batch fermentation. It was found that low initial concentrations of phosphate and ammonium are beneficial for A40926 production and that productivity is not enhanced during...... glucose limitation. Furthermore, the initiation of A40926 production was not governed by residual ammonium and phosphate concentrations, although the level of these nutrients strongly influenced A40926 production rates and final titers....

  7. Stationary-phase production of the antibiotic actinorhodin in Streptomyces coelicolor A3(2) is transcriptionally regulated

    NARCIS (Netherlands)

    Gramajo, Hugo C.; Takano, Eriko; Bibb, Mervyn J.

    1993-01-01

    Production of actinorhodin, a polyketide antibiotic made by Streptomyces coelicolor A3(2), normally occurs only in stationary-phase cultures. S1 nuclease protection experiments showed that transcription of actII-ORF4, the activator gene required for expression of the biosynthetic structural genes,

  8. Prevalence, virulence factor genes and antibiotic resistance of Bacillus cereus sensu lato isolated from dairy farms and traditional dairy products

    DEFF Research Database (Denmark)

    Owusu-Kwarteng, James; Wuni, Alhassan; Akabanda, Fortune

    2017-01-01

    Background: B. cereus are of particular interest in food safety and public health because of their capacity to cause food spoilage and disease through the production of various toxins. The aim of this study was to determine the prevalence, virulence factor genes and antibiotic resistance profile...

  9. Production of antibiotics by Collybia nivalis, Omphalotus olearis, a Favolaschia and a Pterula species on natural substrates.

    Science.gov (United States)

    Engler, M; Anke, T; Sterner, O

    1998-01-01

    Collybia nivalis, Favolaschia sp. 87129, Pterula sp. 82168 and Omphalotus olearius were cultivated on natural substrates. The antibiotic metabolites oudemansin A. strobilurins A, D, illudin S and pterulone were isolated and identified. A new antifungal metabolite, pterulone B, was described from cultures of Pterula sp. 82168 on wood. Collybia nivalis was found to be the first species of this genus to produce strobilurins and oudemansin A. As compared to rich media the cultivation on natural substrates resulted in the production of fewer metabolites. The concentrations of the antibiotics, however, were sufficient to inhibit other saprophytic fungi.

  10. Will Duct Tape and Plastic Really Work? Issues Related to Expedient Shelter-In-Place

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, J.H.

    2002-08-30

    Expedient sheltering involves the use of common materials to enhance the safety of a room inside a building against the impacts of a chemical plume. The central premise behind taping and sealing with duct tape and plastic is to reduce airflow into a room. This paper reviews issues associated with the use of expedient sheltering materials and the effectiveness of this strategy. Expedient sheltering provides additional protection to people sheltering in place beyond that provided by the house and by a safe room without expedient measures. The materials chosen for taping and sealing--duct tape and plastic--are appropriate because they effectively reduce infiltration and the materials should withstand a vapor challenge. Taping is essential to reduce air infiltration. Plastic sheeting is not a critical element for reducing air infiltration, but it makes sealing off large windows easier.

  11. Advances in biosensor development for the screening of antibiotic residues in food products of animal origin - A comprehensive review.

    Science.gov (United States)

    Gaudin, Valérie

    2017-04-15

    Antibiotic residues may be found in food of animal origin, since veterinary drugs are used for preventive and curative purposes to treat animals. The control of veterinary drug residues in food is necessary to ensure consumer safety. Screening methods are the first step in the control of antibiotic residues in food of animal origin. Conventional screening methods are based on different technologies, microbiological methods, immunological methods or physico-chemical methods (e.g. thin-layer chromatography, HPLC, LC-MS/MS). Screening methods should be simple, quick, inexpensive and specific, with low detection limits and high sample throughput. Biosensors can meet some of these requirements. Therefore, the development of biosensors for the screening of antibiotic residues has been increasing since the 1980s. The present review provides extensive and up-to-date findings on biosensors for the screening of antibiotic residues in food products of animal origin. Biosensors are constituted of a bioreceptor and a transducer. In the detection of antibiotic residues, even though antibodies were the first bioreceptors to be used, new kinds of bioreceptors are being developed more and more (enzymes, aptamers, MIPs); their advantages and drawbacks are discussed in this review. The different categories of transducers (electrochemical, mass-based biosensors, optical and thermal) and their potential applications for the screening of antibiotic residues in food are presented. Moreover, the advantages and drawbacks of the different types of transducers are discussed. Lastly, outlook and the future development of biosensors for the control of antibiotic residues in food are highlighted. Copyright © 2016. Published by Elsevier B.V.

  12. Slime production and antibiotic susceptibility in staphylococci isolated from clinical samples

    Directory of Open Access Journals (Sweden)

    Seza Arslan

    2007-02-01

    Full Text Available A total of 187 isolates from several clinical specimens were identified to species level as 129 Staphylococcus aureus strains and 58 coagulase-negative staphylococci (CNS strains by the API Staph System (Biomerieux. Slime production was detected both by the conventional Christensen's method as well as by the Congo red agar method. Seventy-two strains of staphylococci isolates (38.5% were found to be slime producers by Christensen's test tube method whereas 58 strains (31% were slime positive with Congo red agar method. There was no statistically significant difference between the two methods for the detection of slime production (P > 0.05. Susceptibility of isolates against antimicrobial agents was tested by the disk diffusion method. Staphylococcal species had resistance to one or more antibiotics. Among the various antimicrobial agents, oxacillin (71.1% and erythromycin (47.1% showed higher resistance than most of the agents used against all isolates. Oxacillin resistant S. aureus (ORSA and oxacillin resistant coagulase-negative staphylococci (ORCNS, 97 (75.2% and 36 (62.1% respectively were frequently observed in strains isolated from clinical materials. Among the ORSA strains, two strains were resistant to vancomycin. Moreover, 96 (74.4% of 129 S. aureus strains were positive for blactamase enzyme. However, 78 (81.25% of 96 b-lactamase positive S. aureus strains were b-lactamase positive ORSA isolates, but none of them had vancomycin resistance.

  13. Antibiotic resistance in lactic acid bacteria isolated from some pharmaceutical and dairy products

    Directory of Open Access Journals (Sweden)

    Gamal Fadl M. Gad

    2014-01-01

    Full Text Available A total of 244 lactic acid bacteria (LAB strains were isolated from 180 dairy and pharmaceutical products that were collected from different areas in Minia governorate, Egypt. LAB were identified phenotypically on basis of morphological, physiological and biochemical characteristics. Lactobacillus isolates were further confirmed using PCR-based assay. By combination of phenotypic with molecular identification Lactobacillus spp. were found to be the dominant genus (138, 76.7% followed by Streptococcus spp. (65, 36.1% and Lactococcus spp. (27, 15%. Some contaminant organisms such as (Staphylococcus spp., Escherichia coli, Salmonella spp., mould and yeast were isolated from the collected dairy samples but pharmaceutical products were free of such contaminants. Susceptibility of LAB isolates to antibiotics representing all major classes was tested by agar dilution method. Generally, LAB were highly susceptible to Beta-lactams except penicillin. Lactobacilli were resistant to vancomycin, however lactococci and streptococci proved to be very susceptible. Most strains were susceptible to tetracycline and showed a wide range of streptomycin MICs. The MICs of erythromycin and clindamycin for most of the LAB were within the normal range of susceptibility. Sixteen Lactobacillus,8 Lactococcus and 8 Streptococcus isolates including all tetracycline and/or erythromycin resistant strains were tested for the presence of tetracycline and/or erythromycin resistant genes [tet(M and/or erm(B]. PCR assays shows that some resistant strains harbor tet(M and/or erm(B resistance genes.

  14. Chlorination and chloramination of tetracycline antibiotics: disinfection by-products formation and influential factors.

    Science.gov (United States)

    Zhou, Shiqing; Shao, Yisheng; Gao, Naiyun; Zhu, Shumin; Ma, Yan; Deng, Jing

    2014-09-01

    Formation of disinfection by-products (DBPs) from chlorination and chloramination of tetracycline antibiotics (TCs) was comprehensively investigated. It was demonstrated that a connection existed between the transformation of TCs and the formation of chloroform (CHCl3), carbon tetrachloride (CCl4), dichloroacetonitrile (DCAN) and dichloroacetone (DCAce). Factors evaluated included chlorine (Cl2) and chloramine(NH2Cl) dosage, reaction time, solution pH and disinfection modes. Increased Cl2/NH2Cl dosage and reaction time improved the formation of CHCl3 and DCAce. Formation of DCAN followed an increasing and then decreasing pattern with increasing Cl2 dosage and prolonged reaction time. pH affected DBPs formation differently, with CHCl3 and DCAN decreasing in chlorination, and having maximum concentrations at pH 7 in chloramination. The total concentrations of DBPs obeyed the following order: chlorination>chloramination>pre-chlorination (0.5h)>pre-chlorination (1h)>pre-chlorination (2h). Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Molecular characterization and antibiotic resistance profiles ofSalmonellaisolated from fecal matter of domestic animals and animal products in Nairobi.

    Science.gov (United States)

    Nyabundi, Diana; Onkoba, Nyamongo; Kimathi, Rinter; Nyachieo, Atunga; Juma, Gerald; Kinyanjui, Peter; Kamau, Joseph

    2017-01-01

    Salmonella has significant public health implications causing food borne and zoonotic diseases in humans. Treatment of infections due to Salmonella is becoming difficult due to emergence of drug resistant strains. There is therefore need to characterize the circulating non-typhoidal Salmonella (NTS) serovars in domestic animals and animal products in Kenya as well as determine their antibiotic resistance profiles. A total of 740 fecal samples were collected from cows ( n  = 150), pigs ( n  = 182), chicken ( n  = 191) and chicken eggs ( n  = 217) from various markets and abattoirs in Nairobi. The prevalence of NTS serovars using culture techniques and biochemical tests, antimicrobial sensitivity testing using disc diffusion method of the commonly prescribed antibiotics and phylogenetic relationships using 16S rRNA were determined. The results showed that the overall prevalence of Salmonella was 3.8, 3.6, 5.9 and 2.6% for pigs, chicken, eggs and cows respectively. Two serovars were isolated S. Typhimurium (85%) and S. Enteritidis (15%) and these two serovars formed distinct clades on the phylogenetic tree. Forty percent of the isolates were resistant to one or more antibiotics. The isolation of Salmonella Typhimurium and Salmonella Enteritidis that are resistant to commonly used antibiotics from seemingly healthy animals and animal products poses a significant public health threat. This points to the need for regular surveillance to be carried out and the chain of transmission should be viewed to ascertain sources of contamination.

  16. Effects of salinity on antibiotic production in sponge-derived Salinispora actinobacteria.

    Science.gov (United States)

    Ng, Y K; Hodson, M P; Hewavitharana, A K; Bose, U; Shaw, P N; Fuerst, J A

    2014-07-01

    To investigate the effects of growth conditions related to marine habitat on antibiotic production in sponge-derived Salinispora actinobacteria. Media with varying salt concentration were used to investigate the effects of salinity in relation to Salinispora growth and rifamycin production. The chemotypic profiles of the model strain Salinispora arenicola M413 was then assessed using metabolomic fingerprints from high-pressure liquid chromatography with diode array detection (HPLC-DAD) and multivariate data analysis, before extending this approach to two other strains of S. arenicola. Fingerprint data were generated from extracts of S. arenicola broth cultures grown in media of varying salt (NaCl) concentrations. These fingerprints were then compared using multivariate analysis methods such as principal components analysis (PCA) and orthogonal projection to latent structures discriminant analysis (OPLS-DA). From the analysis, a low-sodium growth condition (1% NaCl) was found to delay the onset of growth of the model S. arenicola M413 strain when compared to growth in media with either 3% artificial sea salt or 3% NaCl. However, low-sodium growth conditions also increased cell mass yield and contributed to at least a significant twofold increase in rifamycin yield when compared to growth in 3% artificial sea salt and 3% NaCl. The integration of HPLC-DAD and multivariate analysis proved to be an effective method of assessing chemotypic variations in Salinispora grown in different salt conditions, with clear differences between strain-related chemotypes apparent due to varying salt concentrations. The observed variation in S. arenicola chemotypic profiles further suggests diversity in secondary metabolites in this actinomycete in response to changes in the salinity of its environment. © 2014 The Society for Applied Microbiology.

  17. Characterization of Antibiotic Resistance Genes from Lactobacillus Isolated from Traditional Dairy Products.

    Science.gov (United States)

    Guo, Huiling; Pan, Lin; Li, Lina; Lu, Jie; Kwok, Laiyu; Menghe, Bilige; Zhang, Heping; Zhang, Wenyi

    2017-03-01

    Lactobacilli are widely used as starter cultures or probiotics in yoghurt, cheese, beer, wine, pickles, preserved food, and silage. They are generally recognized as safe (GRAS). However, recent studies have shown that some lactic acid bacteria (LAB) strains carry antibiotic resistance genes and are resistant to antibiotics. Some of them may even transfer their intrinsic antibiotic resistance genes to other LAB or pathogens via horizontal gene transfer, thus threatening human health. A total of 33 Lactobacillus strains was isolated from fermented milk collected from different areas of China. We analyzed (1) their levels of antibiotic resistance using a standardized dilution method, (2) their antibiotic resistance gene profiles by polymerase chain reaction (PCR) using gene-specific primers, and (3) the transferability of some of the detected resistance markers by a filter mating assay. All Lactobacillus strains were found to be resistant to vancomycin, but susceptible to gentamicin, linezolid, neomycin, erythromycin, and clindamycin. Their susceptibilities to tetracycline, kanamycin, ciprofloxacin, streptomycin, quinupristin/dalfopristin, trimethoprim, ampicillin, rifampicin, and chloramphenicol was different. Results from our PCR analysis revealed 19 vancomycin, 10 ciprofloxacin, and 1 tetracycline-resistant bacteria that carried the van(X), van(E), gyr(A), and tet(M) genes, respectively. Finally, no transferal of the monitored antibiotic resistance genes was observed in the filter mating assay. Taken together, our study generated the antibiotic resistance profiles of some milk-originated lactobacilli isolates and preliminarily assessed their risk of transferring antibiotic gene to other bacteria. The study may provide important data concerning the safe use of LAB. © 2017 Institute of Food Technologists®.

  18. Synergistic effect of 14-alpha-lipoyl andrographolide and various antibiotics on the formation of biofilms and production of exopolysaccharide and pyocyanin by Pseudomonas aeruginosa.

    Science.gov (United States)

    Zeng, Xiangping; Liu, Xiangyang; Bian, Jiang; Pei, Gang; Dai, Huanqin; Polyak, Steven W; Song, Fuhang; Ma, Li; Wang, Yuqiang; Zhang, Lixin

    2011-06-01

    Pseudomonas aeruginosa produces a biofilm that provides the bacteria with an effective barrier against antibiotics. Here, we investigated the synergy of various antibiotics with 14-alpha-lipoyl andrographolide (AL-1), focusing upon synthesis of the biofilm. AL-1 also inhibited the production of the exopolysaccharide and pyocyanin components. We propose that AL-1 may potentially serve as a cotherapy to combat P. aeruginosa.

  19. Prepartum antibiotic treatment of heifers: milk production, milk quality and economic benefit.

    Science.gov (United States)

    Oliver, S P; Lewis, M J; Gillespie, B E; Dowlen, H H; Jaenicke, E C; Roberts, R K

    2003-04-01

    Prepartum intramammary antibiotic infusion of heifer mammary glands at 7 or 14 d before expected parturition is an effective procedure for eliminating many infections in heifers during late gestation and for reducing the prevalence of mastitis in heifers during early lactation and throughout lactation. Mastitis pathogens were isolated from 76% of samples obtained from untreated control quarters 7 d before expected calving, from 47% of samples obtained 3 d after calving, and from 29% of samples obtained 10 d postpartum. Mastitis pathogens were isolated from about 30% of control quarters through 240 d of lactation. A similar percentage of samples (70%) was positive for mastitis pathogens at C-7 before antibiotic treatment. However, only 8% of samples obtained at 3 d after calving and 4% of samples obtained at 10 d postpartum from quarters of antibiotic-treated heifers contained mastitis pathogens. Throughout the remainder of lactation, mastitis pathogens were isolated from an average of about 11% of quarters. The percentage of samples with mastitis pathogens was higher in untreated controls than in antibiotic-treated quarters at all sampling intervals during lactation. A similar response was observed in heifers that were treated with antibiotics at 14 d before expected parturition. Prepartum antibiotic-treated heifers produced significantly more milk than control heifers and had significantly lower somatic cell count scores than untreated control heifers. These observations are likely associated with or due to the lower prevalence of mastitis pathogen isolation in prepartum antibiotic-treated heifers throughout lactation. Prepartum antibiotic-treated heifers produced 531 kg more milk than heifers in the untreated control group. Multiplying this increase by a milk price of 0.407 dollars/kg yielded a 216.24 dollars per-heifer increase in gross revenue. The cost of treatment, including the cost of testing for antibiotic residues, was estimated at 15.60 dollars for a net

  20. Prevalence, characterization, and antibiotic susceptibility of Vibrio parahaemolyticus isolated from retail aquatic products in North China.

    Science.gov (United States)

    Xu, Xiaoke; Cheng, Jianheng; Wu, Qingping; Zhang, Jumei; Xie, Tengfei

    2016-03-09

    Vibrio parahaemolyticus is a major foodborne pathogen, particularly in Asian countries. Increased occurrence of outbreaks of V. parahaemolyticus gastroenteritis in China indicates the need to evaluation of the prevalence of this pathogenic species. V. parahaemolyticus distribution in shellfish from the eastern coast of China has been reported previously. However, to date, the prevalence of V. parahaemolyticus in retail aquatic products in North China has not been determined. To investigate the prevalence of V. parahaemolyticus in aquatic products in North China, 260 aquatic product samples were obtained from retail markets in 6 provinces of North China from November to December in 2012 and July to August in 2013. V. parahaemolyticus was detected in 94 (36.2%) of the samples by the most probable number method. The density of V. parahaemolyticus ranged from 1.50 to 1100 MPN/g. V. parahaemolyticus was detected at a rate of 50.0% and 22.7% in summer and in winter, respectively. The density of V. parahaemolyticus was significantly higher in summer than in winter, with mean levels of 16.5 MPN/g and 5.0 MPN/g, respectively. Among 145 V. parahaemolyticus isolates examined, none of the isolates possessed tdh and trh. In multiplex PCR-based O-antigen serotyping of these 145 isolates, all serotypes, other than O6, O7, and O9, were detected, and serotype O2 was found to be the most prevalent (detected in 54 isolates). The 145 isolates were grouped into 7 clusters by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) at a similarity coefficient of 0.66. The antimicrobial resistance patterns of these 145 isolates to 12 antimicrobial agents revealed that most of the isolates were resistant to streptomycin (86.2%), while fewer were resistant to ampicillin (49.6%), cefazolin (43.5%), cephalothin (35.9%), and kanamycin (22.1%). All of the examined isolates were susceptible to azithromycin and chloramphenicol. The findings of this study will help

  1. Degradation of 2,4-dichlorophenoxyacetic acid by a halotolerant strain of Penicillium chrysogenum: antibiotic production.

    Science.gov (United States)

    Ferreira-Guedes, Sumaya; Mendes, Benilde; Leitão, Ana Lúcia

    2012-01-01

    The extensive use of pesticides in agriculture has prompted intensive research on chemical and biological methods in order to protect contamination of water and soil resources. In this paper the degradation of the pesticide 2,4-dichlorophenoxyacetic acid by a Penicillium chrysogenum strain previously isolated from a salt mine was studied in batch cultures. Co-degradation of 2,4-dichlorophenoxyacetic acid with additives such as sugar and intermediates of pesticide metabolism was also investigated. Penicillium chrysogenum in solid medium was able to grow at concentrations up to 1000 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) with sucrose. Meanwhile, supplementation of the solid medium with glucose and lactose led to fungal growth at concentrations up to 500 mg/L of herbicide. Batch cultures of 2,4-D at 100 mg/L were developed under aerobic conditions with the addition of glucose, lactose and sucrose, showing sucrose as the best additional carbon source. The 2,4-D removal was quantified by liquid chromatography. The fungus was able to use 2,4-D as the sole carbon and energy source under 0%, 2% and 5.9% NaCl. The greatest 2,4-D degradation efficiency was found using alpha-ketoglutarate and ascorbic acid as co-substrates under 2% NaCl at pH 7. Penicillin production was evaluated in submerged cultures by bioassay, and higher amounts of beta-lactam antibiotic were produced when the herbicide was alone. Taking into account the ability of P. chrysogenum CLONA2 to degrade aromatic compounds, this strain could be an interesting tool for 2,4-D herbicide remediation in saline environments.

  2. Antibiotic Resistance

    Science.gov (United States)

    ... But there is a growing problem of antibiotic resistance. It happens when bacteria change and become able ... of an antibiotic. Using antibiotics can lead to resistance. Each time you take antibiotics, sensitive bacteria are ...

  3. ANTIBIOTIC RESISTANCE IN LACTIC ACID BACTERIA ISOLATED FROM FERMENTED DAIRY PRODUCTS AND BOZA

    Directory of Open Access Journals (Sweden)

    Gamze Başbülbül

    2015-06-01

    Full Text Available In this study, the resistance of 83 strains of lactic acid bacteria isolated from Turkish cheese, yogurt, kefir and boza samples to 6 antibiotics (gentamicin, tetracycline, chloramphenicol, erythromycin, vancomycin and ciprofloxacin was evaluated. The 83 isolates were identified by 16S rRNA gene sequencing and according to BLAST comparisons with sequences in the data banks, those strains showing the highest similarities with the isolates were Enterococcus faecium (10, Lactococcus lactis subsp. Lactis (10, Lactobacillus fermentum (6, Lactobacillus plantarum (6, Lactobacillus coryniformis (7, Lactobacillus casei (13, Leuconostoc mesenteroides (14, Pediococcus pentosaceus (10, Weisella confusa (7. Antimicrobial resistance of strains to 6 antibiotics was determined using the agar dilution method. The antibiotic resistance among all the isolates was detected against chloramphenicol (31,3 % of the isolates, tetracycline (30,1 %, erythromycin (2,4 %, ciprofloxacin (2,41%, vancomycin (73,5 %, intrinsic resistance. Overall 19,3 % of the isolates showed resistance against multiple antibiotics. Antibiotic resistance genes were studied by PCR and the following genes were detected; tet(M gene in Lactobacillus fermentum (1, Lactobacillus plantarum (1, Pediococcus pentosaceus (5, Enterococcus faecium (2, Weisella confusa (4 and the vancomycin resistance gene van(A in one Weisella confusa strain.

  4. Potential for Bacteriophage Endolysins to Supplement or Replace Antibiotics in Food Production and Clinical Care

    Directory of Open Access Journals (Sweden)

    Michael J. Love

    2018-02-01

    Full Text Available There is growing concern about the emergence of bacterial strains showing resistance to all classes of antibiotics commonly used in human medicine. Despite the broad range of available antibiotics, bacterial resistance has been identified for every antimicrobial drug developed to date. Alarmingly, there is also an increasing prevalence of multidrug-resistant bacterial strains, rendering some patients effectively untreatable. Therefore, there is an urgent need to develop alternatives to conventional antibiotics for use in the treatment of both humans and food-producing animals. Bacteriophage-encoded lytic enzymes (endolysins, which degrade the cell wall of the bacterial host to release progeny virions, are potential alternatives to antibiotics. Preliminary studies show that endolysins can disrupt the cell wall when applied exogenously, though this has so far proven more effective in Gram-positive bacteria compared with Gram-negative bacteria. Their potential for development is furthered by the prospect of bioengineering, and aided by the modular domain structure of many endolysins, which separates the binding and catalytic activities into distinct subunits. These subunits can be rearranged to create novel, chimeric enzymes with optimized functionality. Furthermore, there is evidence that the development of resistance to these enzymes may be more difficult compared with conventional antibiotics due to their targeting of highly conserved bonds.

  5. Bakery by-products based feeds borne-Saccharomyces cerevisiae strains with probiotic and antimycotoxin effects plus antibiotic resistance properties for use in animal production.

    Science.gov (United States)

    Poloni, Valeria; Salvato, Lauranne; Pereyra, Carina; Oliveira, Aguida; Rosa, Carlos; Cavaglieri, Lilia; Keller, Kelly Moura

    2017-09-01

    The aim of this study was to select S. cerevisiae strains able to exert probiotic and antimycotoxin effects plus antibiotics resistance properties for use in animal production. S. cerevisiae LL74 and S. cerevisiae LL83 were isolated from bakery by-products intended for use in animal feed and examined for phenotypic characteristics and nutritional profile. Resistance to antibiotic, tolerance to gastrointestinal conditions, autoaggregation and coaggregation assay, antagonism to animal pathogens and aflatoxin B 1 binding were studied. S. cerevisiae LL74 and S. cerevisiae LL83 showed resistance to all the antibiotics assayed (ampicillin, streptomycin, neomycin, norfloxacin, penicillin G, sulfonamide and trimethoprim). The analysis showed that exposure time to acid pH had a significant impact onto the viable cell counts onto both yeast strains. Presence of bile 0.5% increased significantly the growth of the both yeast strains. Moreover, they were able to tolerate the simulated gastrointestinal conditions assayed. In general, the coaggregation was positive whereas the autoaggregation capacity was not observed. Both strains were able to adsorb AFB 1 . In conclusion, selected S. cerevisiae LL74 and S. cerevisiae LL83 have potential application to be used as a biological method in animal feed as antibiotic therapy replacement in, reducing the adverse effects of AFB 1 and giving probiotic properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Toward steadfast growth of antibiotic research in China: from natural products to engineered biosynthesis.

    Science.gov (United States)

    Kang, Qianjin; Bai, Linquan; Deng, Zixin

    2012-01-01

    Antibiotics are widely used for clinical treatment and preventing or curing diseases in agriculture. Cloning and studies of their biosynthetic gene clusters are vital for yield enhancement and engineering new derivatives with new and prominent activities. In recent years, research in this aspect is impressively active in China. This article reviews biosynthetic progress on 28 antibiotics, including polyketides, nonribosomal peptides, hybrid polyketide-nonribosomal peptides, peptidyl nucleoside, nucleoside, and others. Their biosynthetic mechanisms were disclosed, and their derivatives with new structures/activities were obtained by gene inactivation, mutasynthesis and combinatorial biosynthesis. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Gene Sequence Based Clustering Assists in Dereplication of Pseudoalteromonas luteoviolacea Strains with Identical Inhibitory Activity and Antibiotic Production

    DEFF Research Database (Denmark)

    Vynne, Nikolaj Grønnegaard; Månsson, Maria; Gram, Lone

    2012-01-01

    Some microbial species are chemically homogenous, and the same secondary metabolites are found in all strains. In contrast, we previously found that five strains of P. luteoviolacea were closely related by 16S rRNA gene sequence but produced two different antibiotic profiles. The purpose of the p......Some microbial species are chemically homogenous, and the same secondary metabolites are found in all strains. In contrast, we previously found that five strains of P. luteoviolacea were closely related by 16S rRNA gene sequence but produced two different antibiotic profiles. The purpose...... of the present study was to determine whether such bioactivity differences could be linked to genotypes allowing methods from phylogenetic analysis to aid in selection of strains for biodiscovery. Thirteen P. luteoviolacea strains divided into three chemotypes based on production of known antibiotics and four...... correlation to chemotypes and inhibition profiles, while clustering based on concatenated 16S rRNA, gyrB, and recA gene sequences resulted in three clusters, two of which uniformly consisted of strains of identical chemotype and inhibition profile. A major time sink in natural products discovery is the effort...

  8. Access the toxic effect of the antibiotic cefradine and its UV light degradation products on two freshwater algae.

    Science.gov (United States)

    Chen, J Q; Guo, R X

    2012-03-30

    Two common freshwater algae Microcystis aeruginosa and Scenedesmus obliquus were employed as test organism to evaluate the toxic effects of the widely used antibiotic, cefradine. In general, cefradine had significantly toxic effect on population growth and chlorophyll-a accumulation of two algae and the cyanophyceae was more sensitive than the chlorophyceae. In addition, cefradine UV light degraded products had adverse effect on M. aeruginosa's growth and chlorophyll-a accumulation. In comparison, even if S. obliquus had growth ability when exposed to cefradine UV light-degradation products, the algal photosynthesis function was also disrupted. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Bioprocess intensification of antibiotic production by Streptomyces coelicolor A3(2) in micro-porous culture

    Energy Technology Data Exchange (ETDEWEB)

    Ndlovu, T.M., E-mail: tm.ndlovu@nutriss.com [NUTRISS Limited, INEX, Herschel Annex, Kings Road, Newcastle upon Tyne NE1 7RU (United Kingdom); Ward, A.C. [School of Biology, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Department of Microbiology, Chung-Ang University, College of Medicine, Seoul, Republic of Korea 156-756 (Korea, Republic of); Glassey, J. [School of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Eskildsen, J. [NUTRISS Limited, INEX, Herschel Annex, Kings Road, Newcastle upon Tyne NE1 7RU (United Kingdom); Akay, G. [School of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2015-04-01

    A novel functionalized micro-porous matrix was developed with well-controlled physicochemical proprieties such as pore size and surface chemistry. The matrix was used as a solid support in the growth of “Streptomyces coelicolor” A3(2) to enhance the production of antibiotics. The results shown support a higher production of prodigiosin and actinorhodin with overall production increase of 2–5 and 6–17, respectively, compared to conventional submerged liquid culture, offering a potential improvement in volumetric productivity. Scanning Electron Microscopy was used to evaluate pore size as well as bacterial adhesion, penetration, proliferation and migration within the micro-porous matrix. - Highlights: • Preparation of novel micro-porous matrix with different physiochemical proprieties • S. coelicolor A3(2) was cultured in those micro-porous and antibiotics was enhanced. • Matrix pore sizes and surface chemistry influenced bacterial signalling. • Bacterial signalling has a profound effect in the overproduction of Prodigiosin and actinorhodin. • Prodigiosin and actinorhodin production within micro-porous was 5–17 times higher compared with liquid growth.

  10. Prevalence, antibiotic resistance, and molecular characterization of Salmonella serovars in retail meat products.

    Science.gov (United States)

    Hyeon, Ji-Yeon; Chon, Jung-Whan; Hwang, In-Gyun; Kwak, Hyo-Sun; Kim, Moo-Sang; Kim, Soo-Ki; Choi, In-Soo; Song, Chang-Seon; Park, Chankyu; Seo, Kun-Ho

    2011-01-01

    The prevalence of Salmonella was determined in chicken meat (n = 26), beef (n = 49), and pork (n = 56) collected from wholesale markets, retail stores, and traditional markets in Seoul, South Korea, in 2009. Antibiotic resistance was assessed, and the molecular subtypes of Salmonella isolates were ascertained using an automated repetitive sequence-based PCR (rep-PCR) system (DiversiLab). A total of 18 Salmonella strains were isolated from 17 of 131 samples: 16 strains from each of 16 samples and 2 strains from the same pork sample. The prevalence of Salmonella from the retail meats was 2.0% in beef, 8.9% in pork, and 42.3% in chicken meat. Among 10 different serotypes, Salmonella enterica Panama was recovered from a beef sample, and Salmonella London and Salmonella Montevideo were the predominant serotypes from pork and chicken meat, respectively. The highest antibiotic resistance observed was to erythromycin (100%) followed by streptomycin (22.2%) and tetracycline and chloramphenicol (16.7%). Of the 18 isolates, 5 (27.8%) were resistant to two or more antibiotics, and 1 isolate from chicken meat was resistant to eight antibiotics, including cephalosporins. Differentiation between all of the Salmonella isolates except between Salmonella Montevideo and Salmonella London was successfully performed with the automated rep-PCR system, indicating that it can be added to the toolbox for source tracking of foodborne pathogens associated with outbreaks.

  11. Alternatives to antibiotics as growth promoters for use in swine production: a review.

    Science.gov (United States)

    Thacker, Philip A

    2013-09-14

    In the past two decades, an intensive amount of research has been focused on the development of alternatives to antibiotics to maintain swine health and performance. The most widely researched alternatives include probiotics, prebiotics, acidifiers, plant extracts and neutraceuticals such as copper and zinc. Since these additives have been more than adequately covered in previous reviews, the focus of this review will be on less traditional alternatives. The potential of antimicrobial peptides, clay minerals, egg yolk antibodies, essential oils, eucalyptus oil-medium chain fatty acids, rare earth elements and recombinant enzymes are discussed. Based on a thorough review of the literature, it is evident that a long and growing list of compounds exist which have been tested for their ability to replace antibiotics as feed additives in diets fed to swine. Unfortunately, the vast majority of these compounds produce inconsistent results and rarely equal antibiotics in their effectiveness. Therefore, it would appear that research is still needed in this area and that the perfect alternative to antibiotics does not yet exist.

  12. Coevolution of antibiotic production and counter-resistance in soil bacteria.

    Science.gov (United States)

    Laskaris, Paris; Tolba, Sahar; Calvo-Bado, Leo; Wellington, Elizabeth M; Wellington, Liz

    2010-03-01

    We present evidence for the coexistence and coevolution of antibiotic resistance and biosynthesis genes in soil bacteria. The distribution of the streptomycin (strA) and viomycin (vph) resistance genes was examined in Streptomyces isolates. strA and vph were found either within a biosynthetic gene cluster or independently. Streptomyces griseus strains possessing the streptomycin cluster formed part of a clonal complex. All S. griseus strains possessing solely strA belonged to two clades; both were closely related to the streptomycin producers. Other more distantly related S. griseus strains did not contain strA. S. griseus strains with only vph also formed two clades, but they were more distantly related to the producers and to one another. The expression of the strA gene was constitutive in a resistance-only strain whereas streptomycin producers showed peak strA expression in late log phase that correlates with the switch on of streptomycin biosynthesis. While there is evidence that antibiotics have diverse roles in nature, our data clearly support the coevolution of resistance in the presence of antibiotic biosynthetic capability within closely related soil dwelling bacteria. This reinforces the view that, for some antibiotics at least, the primary role is one of antibiosis during competition in soil for resources.

  13. Abundance and distribution of antibiotic resistance genes in a full-scale anaerobic-aerobic system alternately treating ribostamycin, spiramycin and paromomycin production wastewater.

    Science.gov (United States)

    Tang, Mei; Dou, Xiaomin; Wang, Chunyan; Tian, Zhe; Yang, Min; Zhang, Yu

    2017-12-01

    The occurrence of antibiotic-resistant bacteria and antibiotic resistance genes (ARGs) has been intensively investigated for wastewater treatment systems treating single class of antibiotic in recent years. However, the impacts of alternately occurring antibiotics in antibiotic production wastewater on the behavior of ARGs in biological treatment systems were not well understood yet. Herein, techniques including high-capacity quantitative PCR and quantitative PCR (qPCR) were used to investigate the behavior of ARGs in an anaerobic-aerobic full-scale system. The system alternately treated three kinds of antibiotic production wastewater including ribostamycin, spiramycin and paromomycin, which referred to stages 1, 2 and 3. The aminoglycoside ARGs (52.1-79.3%) determined using high-capacity quantitative PCR were the most abundant species in all sludge samples of the three stages. The total relative abundances of macrolide-lincosamide-streptogramin (MLS) resistance genes and aminoglycoside resistance genes measured using qPCR were significantly higher (P sludge than in sewage sludge. However, the comparison of ARGs acquired from three alternate stages revealed that MLS genes and the aminoglycoside ARGs did not vary significantly (P > 0.05) in both aerobic and anaerobic sludge samples. In aerobic sludge, one acetyltransferase gene (aacA4) and the other three nucleotidyltransferase genes (aadB, aadA and aadE) exhibited positive correlations with intI1 (r 2  = 0.83-0.94; P antibiotic production wastewater treatment systems.

  14. Antibiotic resistance patterns of Escherichia coli strains isolated from surface water and groundwater samples in a pig production area

    Directory of Open Access Journals (Sweden)

    Roger Neto Schneider

    2009-09-01

    Full Text Available The use of antibiotics, so excessive and indiscriminate in intensive animal production, has triggered an increase in the number of resistant microorganisms which can be transported to aquatic environments. The aim of this study was to determine the profile of the antimicrobial resistance of samples of Escherichia coli isolated from groundwater and surface water in a region of pig breeding. Through the test of antimicrobial susceptibility, we analyzed 205 strains of E. coli. A high rate of resistance to cefaclor was observed, both in surface water (51.9% and groundwater (62.9%, while all samples were sensitive to amikacin. The percentages of multi-resistant samples were 25.96% and 26.73% in surface water and groundwater, respectively, while 19.23% and 13.86% were sensitive to all antibiotics tested. It was determined that the rate of multiple antibiotic resistance (MAR was 0.164 for surface water and 0.184 for groundwater. No significant differences were found in the profile of the antimicrobial resistance in strains of E. coli isolated in surface water and groundwater, but the index MAR calculated in certain points of groundwater may offer a potential risk of transmission of resistant genes.

  15. Comparison of antibiotic resistance between ecological and conventional breeding in Enterobacteriaceae genera isolated from milk and milk products

    Directory of Open Access Journals (Sweden)

    Lukáš Hleba

    2011-01-01

    Full Text Available The aim of this study was to determine and compare antibiotic resistance of Enterobacteriaceae ­genera isolated from milk and milk products like cheese, bryndza, srvátka and parenica from ecological and conventional breeding from different regions of Slovakia. Distance between breedings was about 20 km. In the both breeding were not used antibiotics. The Enterobacteriaceae isolates were tested for susceptibility to three antibiotics ampicillin (AMP, nalixid acid (NA 30 and chloramphenicol (C 30. In our study, we determined that the highest resistance of Enterobacteriaceae strains was to ampicillin (100 % in conventional breeding. The higher resistance in conventional breeding is probably due to greater anthropogenic influences. In ecological breeding we determined 84.61% resistance to ampicillin. The highest susceptibility was to chloramphenicol and nalixid acid (100 % in conventional breeding. In the ecological breeding resistance to chloramphenicol was 15.38 % and resistance to nalixid acid 7.69 % from all tested isolates. Conversely, higher resistance to chloramphenicol and nalixid acid in the ecological breeding may be due to the persistence of resistant genes in environment. The lowest resistance to chloramphenicol and nalixid acid in conventional breeding may be due to the prohibition of the use of antibiotics as growth promoters. From this genera, we identified Klebsiella oxytoca, Serratia odorifera bv.1, Serratia odorifera bv. 2, Citrobacter braakii and Escherichia coli from conventional breeding which were resistant to ampicillin and isolated from cheese, bryndza and parenica. In the ecological breeding we identified this strains: Raoultella ornithinolytica resistant to ampicillin, Serratia rubidaea, which was resistant to all of used antibiotics and this strains were isolated from milk samples and Klebsiella pneumoniae, Escherichia coli, Klebsiella oxytoca which were resistant to ampicillin and were isolated from cheese

  16. Modulation of the gut microbiota with antibiotic treatment suppresses whole body urea production in neonatal pigs

    DEFF Research Database (Denmark)

    Puiman, Patrycja; Stoll, Barbara; Mølbak, Lars

    2013-01-01

    We examined whether changes in the gut microbiota induced by clinically relevant interventions would impact the bioavailability of dietary amino acids in neonates. We tested the hypothesis that modulation of the gut microbiota in neonatal pigs receiving no treatment (control), intravenously...... in the proximal SI but not in other tissues. In conclusion, modulation of the gut microbiota by antibiotics and probiotics reduced hepatic ureagenesis and intestinal protein synthesis, but neither altered whole body net threonine balance. These findings suggest that changes in amino acid and nitrogen metabolism...... resulting from antibiotic- or probiotic-induced shifts in the microbiota are localized to the gut and liver and have limited impact on whole body growth and anabolism in neonatal piglets....

  17. Expedient Access to an N-phenylpyrrolidin-2-yl Heterocycle via a ...

    African Journals Online (AJOL)

    NICO

    Expedient Access to an N-phenylpyrrolidin-2-yl Heterocycle via a Base-Induced Intramolecular aza-Michael Reaction. Josierika A. Ferreira Ramos, Tanus J. Nagem and Jason G. Taylor*. Departamento de Química, ICEB, Universidade Federal de Ouro Preto, Campus Universitário Morro do Cruzeiro,. 35400-000, Ouro ...

  18. Radical fluorination powered expedient synthesis of 3-fluorobicyclo[1.1.1]pentan-1-amine.

    Science.gov (United States)

    Goh, Yi Ling; Adsool, Vikrant A

    2015-12-28

    Exploration of novel chemical space, a modern trend in medicinal chemistry, is heavily reliant on synthetic access to new and interesting building blocks. In this direction, the following work describes an expedient synthesis of one such moiety, 3-fluorobicyclo[1.1.1]pentan-1-amine, by employing radical fluorination.

  19. Manipulation of metabolic pathways controlled by signaling molecules, inducers of antibiotic production, for genome mining in Streptomyces spp.

    Science.gov (United States)

    Arakawa, Kenji

    2018-02-23

    Streptomyces is well characterized by an ability to produce a wide variety of secondary metabolites including antibiotics, whose expression is strictly controlled by small diffusible signaling molecules at nano-molar concentrations. The signaling molecules identified to date are classified into three skeletons; γ-butyrolactones, furans, and γ-butenolides. Accumulated data suggest the structural diversity of the signaling molecules in Streptomyces species and their potential in activating cryptic secondary metabolite biosynthetic pathways. Several genome mining approaches to activate silent biosynthetic gene clusters have been reported for natural product discovery. This review updates recent examples on genetic manipulation including blockage of metabolic pathways together with inactivation of transcriptional repressor genes.

  20. Use of Tn5lac to study expression of genes required for production of the antibiotic TA.

    OpenAIRE

    Tolchinsky, S; Fuchs, N; Varon, M; Rosenberg, E

    1992-01-01

    The beta-galactosidase activities arising from Tn5lac insertions in several genes required for antibiotic TA production were measured under different growth conditions. In all of the non-TA-producing mutants, the beta-galactosidase specific activity was higher when the cells were grown in nutrient-limited 0.5CTS medium (0.5% Casitone plus alanine, serine, and glucose) than in rich 2CT medium (2% Casitone). One of the mutants, 420, had low beta-galactosidase specific activity in both media. Th...

  1. Antibiotic alternatives: the substitution of antibiotics in animal husbandry?

    OpenAIRE

    Cheng, Guyue; Hao, Haihong; Xie, Shuyu; Wang, Xu; Dai, Menghong; Huang, Lingli; Yuan, Zonghui

    2014-01-01

    It is a common practice for decades to use of sub-therapeutic dose of antibiotics in food-animal feeds to prevent animals from diseases and to improve production performance in modern animal husbandry. In the meantime, concerns over the increasing emergence of antibiotic-resistant bacteria due to the unreasonable use of antibiotics and an appearance of less novelty antibiotics have prompted efforts to develop so-called alternatives to antibiotics. Whether or not the alternatives could really ...

  2. Comparison of NF membrane fouling and cleaning by two pretreatment strategies for the advanced treatment of antibiotic production wastewater.

    Science.gov (United States)

    Wang, Jianxing; Li, Kun; Yu, Dawei; Zhang, Junya; Wei, Yuansong; Chen, Meixue; Shan, Baoqing

    2016-01-01

    The nanofiltration (NF) membrane fouling characteristics and cleaning strategies were investigated and compared for treating membrane bioreactor (MBR) effluent and MBR-granular activated carbon (GAC) effluent of an antibiotic production wastewater by DK membrane. Results showed that the fouling of treating MBR effluent was more severe than that of treating MBR-GAC effluent. After filtering for 216 h, the difference of membrane flux decline was obvious between MBR effluent and MBR-GAC effluent, with 14.9% and 10.3% flux decline, respectively. Further study showed that organic fouling is the main NF membrane fouling in the advanced treatment of antibiotic production wastewater for both of the two different effluents. Soluble microbial by-product like and tyrosine-like substances were the dominant components in the foulants, whereas humic-like substances existing in the effluents had little contribution to the NF membrane fouling. A satisfactory efficiency of NF chemical cleaning could be obtained using combination of acid (HCl, pH 2.0-2.5) and alkali (NaOH + 0.3 wt% NaDS, pH 10.0-10.5). The favorable cleaning strategy is acid-alkali for treating the MBR-GAC effluent, while it is alkali-acid for treating the MBR effluent.

  3. Fractionation and analysis of veterinary antibiotics and their related degradation products in agricultural soils and drainage waters following swine manure amendment.

    Science.gov (United States)

    Solliec, Morgan; Roy-Lachapelle, Audrey; Gasser, Marc-Olivier; Coté, Caroline; Généreux, Mylène; Sauvé, Sébastien

    2016-02-01

    The fate of antimicrobial active compound residues in the environment, and especially antibiotics used in swine husbandry are of particular interest for their potential toxicity and contribution to antibiotic resistance. The presence of relatively high concentrations of bioactive compounds has been reported in agricultural areas but few information is available on their degradation products. Veterinary antibiotics reach terrestrial environments through many routes, including application of swine manure to soils. The objectives of this project were first, to develop an analytical method able to quantify and identify veterinary antibiotics and their degradation products in manure, soil and water samples; and second, to study the distribution of these target compounds in soils and drainage waters. A brief evaluation of their potential toxicity in the environment was also made. In order to achieve these objectives, liquid chromatography coupled to high-resolution mass spectrometry was used for its ability to quantify contaminants with sensitivity and selectivity, and its capacity to identify degradation products. Samples of manure, soil and water came from a long-term experimental site where swine manure containing veterinary antibiotics has been applied for many years. In this study, tetracycline antibiotics were found at several hundred μg L(-1) in the swine manure slurry used for fertilization, several hundred of ng L(-1) in drainage waters and several ng g(-1) in soils, while degradation products were sometimes found at concentrations higher than the parent compounds. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Finding alternatives to antibiotics.

    Science.gov (United States)

    Allen, Heather K; Trachsel, Julian; Looft, Torey; Casey, Thomas A

    2014-09-01

    The spread of antibiotic-resistant pathogens requires new treatments. As the rate of development of new antibiotics has severely declined, alternatives to antibiotics must be considered in both animal agriculture and human medicine. Products for disease prevention are different from those for disease treatment, and examples of both are discussed here. For example, modulating the gut microbial community, either through feed additives or fecal transplantation, could be a promising way to prevent certain diseases; for disease treatment, non-antibiotic approaches include phage therapy, phage lysins, bacteriocins, and predatory bacteria. Interestingly, several of these methods augment antibiotic efficacy by improving bacterial killing and decreasing antibiotic resistance selection. Because bacteria can ultimately evolve resistance to almost any therapeutic agent, it is important to continue to use both antibiotics and their alternatives judiciously. © 2014 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals Inc. on behalf of The New York Academy of Sciences.

  5. Degradation of fluoroquinolone antibiotics and identification of metabolites/transformation products by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Maia, Alexandra S; Ribeiro, Ana R; Amorim, Catarina L; Barreiro, Juliana C; Cass, Quezia B; Castro, Paula M L; Tiritan, Maria Elizabeth

    2014-03-14

    Antibiotics are a therapeutic class widely found in environmental matrices and extensively studied due to its persistence and implications for multi-resistant bacteria development. This work presents an integrated approach of analytical multi-techniques on assessing biodegradation of fluorinated antibiotics at a laboratory-scale microcosmos to follow removal and formation of intermediate compounds. Degradation of four fluoroquinolone antibiotics, namely Ofloxacin (OFL), Norfloxacin (NOR), Ciprofloxacin (CPF) and Moxifloxacin (MOX), at 10 mg L(-1) using a mixed bacterial culture, was assessed for 60 days. The assays were followed by a developed and validated analytical method of LC with fluorescence detection (LC-FD) using a Luna Pentafluorophenyl (2) 3 μm column. The validated method demonstrated good selectivity, linearity (r(2)>0.999), intra-day and inter-day precisions (RSD<2.74%) and accuracy. The quantification limits were 5 μg L(-1) for OFL, NOR and CPF and 20 μg L(-1) for MOX. The optimized conditions allowed picturing metabolites/transformation products formation and accumulation during the process, stating an incomplete mineralization, also shown by fluoride release. OFL and MOX presented the highest (98.3%) and the lowest (80.5%) extent of degradation after 19 days of assay, respectively. A representative number of samples was selected and analyzed by LC-MS/MS with triple quadrupole and the molecular formulas were confirmed by a quadruple time of flight analyzer (QqTOF). Most of the intermediates were already described as biodegradation and/or photodegradation products in different conditions; however unknown metabolites were also identified. The microbial consortium, even when exposed to high levels of FQ, presented high percentages of degradation, never reported before for these compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Antibiotic production by a Roseobacter clade-affiliated species from the German Wadden Sea and its antagonistic effects on indigenous isolates.

    Science.gov (United States)

    Brinkhoff, Thorsten; Bach, Gabriela; Heidorn, Thorsten; Liang, Lanfang; Schlingloff, Andrea; Simon, Meinhard

    2004-04-01

    A strain affiliated with the Roseobacter clade and producing a new antibiotic named tropodithietic acid (L. Liang, Ph.D. thesis, University of Göttingen, Göttingen, Germany, 2003) was isolated from the German Wadden Sea. The compound showed strong inhibiting properties with respect to marine bacteria of various taxa and marine algae. Antibiotic production was found to occur during the complete growth phase. Strain mutants without antagonistic properties appeared several times spontaneously.

  7. Antibiotic Production by a Roseobacter Clade-Affiliated Species from the German Wadden Sea and Its Antagonistic Effects on Indigenous Isolates†

    OpenAIRE

    Brinkhoff, Thorsten; Bach, Gabriela; Heidorn, Thorsten; Liang, Lanfang; Schlingloff, Andrea; Simon, Meinhard

    2004-01-01

    A strain affiliated with the Roseobacter clade and producing a new antibiotic named tropodithietic acid (L. Liang, Ph.D. thesis, University of Göttingen, Göttingen, Germany, 2003) was isolated from the German Wadden Sea. The compound showed strong inhibiting properties with respect to marine bacteria of various taxa and marine algae. Antibiotic production was found to occur during the complete growth phase. Strain mutants without antagonistic properties appeared several times spontaneously.

  8. Alkaline thermal pretreatment at mild temperatures for biogas production from anaerobic digestion of antibiotic mycelial residue.

    Science.gov (United States)

    Li, Chunxing; Zhang, Guangyi; Zhang, Zhikai; Ma, Dachao; Xu, Guangwen

    2016-05-01

    This paper aims at lowering the temperature for thermal pretreatment (TPT) of antibiotic mycelial residue (AMR) by alkali addition but without significantly worsening subsequent anaerobic digestion (AD) for biogas. Batch TPT and AD experiments were conducted in a bench-scale autoclave and several bench-scale anaerobic digesters, respectively. The results showed that the methane yield (small amounts of alkali. It was more convenient and economical to implement AD of AMR in combination with alkaline TPT at mild temperatures for biogas. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Incidence, Antibiotic Susceptibility, and Toxin Profiles of Bacillus cereus sensu lato Isolated from Korean Fermented Soybean Products.

    Science.gov (United States)

    Yim, Jin-Hyeok; Kim, Kwang-Yeop; Chon, Jung-Whan; Kim, Dong-Hyeon; Kim, Hong-Seok; Choi, Da-Som; Choi, In-Soo; Seo, Kun-Ho

    2015-06-01

    Korean fermented soybean products, such as doenjang, kochujang, ssamjang, and cho-kochujang, can harbor foodborne pathogens such as Bacillus cereus sensu lato (B. cereus sensu lato). The aim of this study was to characterize the toxin gene profiles, biochemical characteristics, and antibiotic resistance patterns of B. cereus sensu lato strains isolated from Korean fermented soybean products. Eighty-eight samples of Korean fermented soybean products purchased from retails in Seoul were tested. Thirteen of 26 doenjang samples, 13 of 23 kochujang samples, 16 of 30 ssamjang samples, and 5 of 9 cho-kochujang samples were positive for B. cereus sensu lato strains. The contamination level of all positive samples did not exceed 4 log CFU/g of food (maximum levels of Korea Food Code). Eighty-seven B. cereus sensu lato strains were isolated from 47 positive samples, and all isolates carried at least one enterotoxin gene. The detection rates of hblCDA, nheABC, cytK, and entFM enterotoxin genes among all isolates were 34.5%, 98.9%, 57.5%, and 100%, respectively. Fifteen strains (17.2%) harbored the emetic toxin gene. Most strains tested positive for salicin fermentation (62.1%), starch hydrolysis (66.7%), hemolysis (98.9%), motility test (100%), and lecithinase production (96.6%). The B. cereus sensu lato strains were highly resistant to β-lactam antibiotics such as ampicillin, penicillin, cefepime, imipenem, and oxacillin. Although B. cereus sensu lato levels in Korean fermented soybean products did not exceed the maximum levels permitted in South Korea (<10(4) CFU/g), these results indicate that the bacterial isolates have the potential to cause diarrheal or emetic gastrointestinal diseases. © 2015 Institute of Food Technologists®

  10. Evaluation and validation of a multi-residue method based on biochip technology for the simultaneous screening of six families of antibiotics in muscle and aquaculture products.

    Science.gov (United States)

    Gaudin, Valérie; Hedou, Celine; Soumet, Christophe; Verdon, Eric

    2016-01-01

    The Evidence Investigator™ system (Randox, UK) is a biochip and semi-automated system. The microarray kit II (AM II) is capable of detecting several compounds belonging to different families of antibiotics: quinolones, ceftiofur, thiamphenicol, streptomycin, tylosin and tetracyclines. The performance of this innovative system was evaluated for the detection of antibiotic residues in new matrices, in muscle of different animal species and in aquaculture products. The method was validated according to the European Decision No. EC/2002/657 and the European guideline for the validation of screening methods, which represents a complete initial validation. The false-positive rate was equal to 0% in muscle and in aquaculture products. The detection capabilities CCβ for 12 validated antibiotics (enrofloxacin, difloxacin, ceftiofur, desfuroyl ceftiofur cysteine disulfide, thiamphenicol, florfenicol, tylosin, tilmicosin, streptomycin, dihydrostreptomycin, tetracycline, doxycycline) were all lower than the respective maximum residue limits (MRLs) in muscle from different animal origins (bovine, ovine, porcine, poultry). No cross-reactions were observed with other antibiotics, neither with the six detected families nor with other families of antibiotics. The AM II kit could be applied to aquaculture products but with higher detection capabilities from those in muscle. The detection capabilities CCβ in aquaculture products were respectively at 0.25, 0.10 and 0.5 of the respective MRL in aquaculture products for enrofloxacin, tylosin and oxytetracycline. The performance of the AM II kit has been compared with other screening methods and with the performance characteristics previously determined in honey.

  11. Functional characterization of a three-component regulatory system involved in quorum sensing-based regulation of peptide antibiotic production in Carnobacterium maltaromaticum

    Directory of Open Access Journals (Sweden)

    Quadri Luis EN

    2006-10-01

    Full Text Available Abstract Background Quorum sensing is a form of cell-to-cell communication that allows bacteria to control a wide range of physiological processes in a population density-dependent manner. Production of peptide antibiotics is one of the processes regulated by quorum sensing in several species of Gram-positive bacteria, including strains of Carnobacterium maltaromaticum. This bacterium and its peptide antibiotics are of interest due to their potential applications in food preservation. The molecular bases of the quorum sensing phenomenon controlling peptide antibiotic production in C. maltaromaticum remain poorly understood. The present study was aimed at gaining a deeper insight into the molecular mechanism involved in quorum sensing-mediated regulation of peptide antibiotic (bacteriocin production by C. maltaromaticum. We report the functional analyses of the CS (autoinducer-CbnK (histidine protein kinase-CbnR (response regulator three-component regulatory system and the three regulated promoters involved in peptide antibiotic production in C. maltaromaticum LV17B. Results CS-CbnK-CbnR system-dependent activation of carnobacterial promoters was demonstrated in both homologous and heterologous hosts using a two-plasmid system with a β-glucuronidase (GusA reporter read-out. The results of our analyses support a model in which the CbnK-CbnR two-component signal transduction system is necessary and sufficient to transduce the signal of the peptide autoinducer CS into the activation of the promoters that drive the expression of the genes required for production of the carnobacterial peptide antibiotics and the immunity proteins that protect the producer bacterium. Conclusions The CS-CbnK-CbnR triad forms a three-component regulatory system by which production of peptide antibiotics by C. maltaromaticum LV17B is controlled in a population density-dependent (or cell proximity-dependent manner. This regulatory mechanism would permit the bacterial

  12. Biofilm formation and antibiotic production in Ruegeria mobilis are influenced by intracellular concentrations of cyclic dimeric guanosinmonophosphate

    DEFF Research Database (Denmark)

    D'Alvise, Paul; Magdenoska, Olivera; Melchiorsen, Jette

    2014-01-01

    formation and production of the potent antibiotic tropodithietic acid (TDA). An introduced phosphodiesterase gene decreased c-di-GMP and reduced biofilm formation and TDA production. tdaC, a key gene for TDA biosynthesis, was expressed only in attached or biofilm-forming cells, and expression was induced...

  13. Insights into solar TiO2-assisted photocatalytic oxidation of two antibiotics employed in aquatic animal production, oxolinic acid and oxytetracycline.

    Science.gov (United States)

    Pereira, João H O S; Reis, Ana C; Queirós, Daniel; Nunes, Olga C; Borges, Maria T; Vilar, Vítor J P; Boaventura, Rui A R

    2013-10-01

    In this study, solar driven TiO2-assisted heterogeneous photocatalytic experiments in a pilot-plant with compound parabolic collectors (CPCs) were carried out to study the degradation of two authorized veterinary antibiotics with particular relevance in finfish aquaculture, oxolinic acid (OXA) and oxytetracycline (OTC), using pure solutions of individual or mixed antibiotics. Firstly, the influence of natural solar photolysis was assessed for each antibiotic. Secondly, photocatalytic degradation kinetic rate constants for individual and mixed antibiotics were compared, using a catalyst load of 0.5 g L(-1) and an initial pH around 7.5. Thirdly, for individually photocatalytic-treated OXA and OTC in the same conditions, the growth inhibition of Escherichia coli DSM 1103 was followed, and the mineralization extent was assessed by the residual dissolved organic carbon (DOC), low-molecular-weight carboxylate anions and inorganic ions concentration. Finally, the effect of inorganic ions, such as chlorides, sulfates, nitrates, phosphates, ammonium and bicarbonates, on the photocatalytic degradation of individual solutions of OXA and OTC was also evaluated and the formation of different reactive oxygen species were probed using selective scavengers. The removal profiles of each antibiotic, both as single component or in mixture were similar, being necessary 2.5 kJ L(-1) of solar UV energy to fully remove them, and 18 kJ(UV) L(-1) to achieve 73% and 81% mineralization, for OXA and OTC, respectively. The remaining organic carbon content was mainly due to low-molecular-weight carboxylate anions. After complete removal of the antibiotics, the remaining degradation by-products no longer showed antibacterial activity. Also, 10% and 55% of the nitrogen content of each antibiotic was converted to ammonium, while no conversion to nitrite or nitrate was detected. The presence of phosphates hindered considerably the removal of both antibiotics, whereas the presence of other inorganic

  14. INVOLVEMENT OF THE INSTITUTE FOR CONTROL OF BIOLOGICAL PRODUCTS AND VETERINARY MEDICINES TO REDUCE THE INCIDENCE AND SPREAD OF ANTIBIOTIC RESISTANCE

    Directory of Open Access Journals (Sweden)

    Alina Draghici

    2016-12-01

    Full Text Available Antibiotics are one of the most important therapeutic discoveries in medical history. They have revolutionized the way we treat patients with bacterial infections and have contributed to reducing the mortality and morbidity from bacterial diseases. Unfortunately, antibiotics have been liable to misuse which leads to the emergence and selection of resistant bacteria. Doctors in Europe and worldwide now are sometimes facing situations where infected patients cannot be treated adequately because the responsible bacterium is totally resistant to available antibiotics. The correct use of antimicrobials is one of the most important tools which could limit the spread of this phenomenon - resistance to antimicrobials. Specialists from Institute for Control of Biological Products and Veterinary Medicines understood to involve in this fight against antibioresistance, by tacking appropriate measures according to the european approches concerning reducing of the antibiotic consumption, correct usage and responsible of them.

  15. [Effect of antibiotics on hemolysin production by bacteria causing mastitis in cattle].

    Science.gov (United States)

    Kurek, C

    1975-01-01

    Effect of six antibiotics on the hemolysin formation by 320 strains of Staphylococcus (including 112 S. aureus) and 100 strains of S. agalactiae isolated from cow udders, have been determined. Tests were performed on plates containing 5% horse red cells, but the hemolytic strains were tested on blood agar plates supplemented with 5% sheep, rabbit and calf cells in addition. One strain of S. aureus produced the rings of hemolysis around the zones of growth inhibition on the media containing the discs of penicillin, erythromycin, oxyterramycin and chloramphenicol. Another strain of S. agalactiae produced similar rings, but only on the medium supplemented with penicillin. On the calf blood agar plate, S. aureus produced the hemolytic rings only in association with streptomycin and neomycin. After five times of propagation on the nutrient agar, the hemolytic phenomenon was not reproducible. It may be suggested that in cow milk there are some inhibitors for hemolysin formation by Staphylococcus and S. agalactiae.

  16. Antibiotic growth promoters enhance animal production by targeting intestinal bile salt hydrolase and its producers

    Directory of Open Access Journals (Sweden)

    Jun eLin

    2014-02-01

    Full Text Available The growth-promoting effect of antibiotic growth promoters (AGPs was correlated with the decreased activity of bile salt hydrolase (BSH, an intestinal bacteria-produced enzyme that exerts negative impact on host fat digestion and utilization. Consistent with this finding, independent chicken studies have demonstrated that AGP usage significantly reduced population of Lactobacillus species, the major BSH-producers in the intestine. Recent finding also demonstrated that some AGPs, such as tetracycline and roxarsone, display direct inhibitory effect on BSH activity. Therefore, BSH is a promising microbiome target for developing novel alternatives to AGPs. Specifically, dietary supplementation of BSH inhibitor may promote host lipid metabolism and energy harvest, consequently enhancing feed efficiency and body weight gain in food animals.

  17. In vitro activities of arylomycin natural-product antibiotics against Staphylococcus epidermidis and other coagulase-negative staphylococci.

    Science.gov (United States)

    Smith, Peter A; Powers, Michael E; Roberts, Tucker C; Romesberg, Floyd E

    2011-03-01

    The arylomycins are a class of natural-product antibiotics that act via the inhibition of type I signal peptidase (SPase), and we have found in diverse bacteria that their activity is limited by the presence of a resistance-conferring Pro residue in SPase that reduces inhibitor binding. We have also demonstrated that Staphylococcus epidermidis, which lacks this Pro residue, is extremely susceptible to the arylomycins. Here, to further explore the potential utility of the arylomycins, we report an analysis of the activity of a synthetic arylomycin derivative, arylomycin C₁₆, against clinical isolates of S. epidermidis and other coagulase-negative staphylococci (CoNS) from distinct geographical locations. Against many important species of CoNS, including S. epidermidis, S. haemolyticus, S. lugdunensis, and S. hominis, we find that arylomycin C₁₆ exhibits activity equal to or greater than that of vancomycin, the antibiotic most commonly used to treat CoNS infections. While the susceptibility was generally correlated with the absence of the previously identified Pro residue, several cases were identified where additional factors also appear to contribute.

  18. BLANKET REPRESENTATION AND EXPEDIENT OF DISINFECTING WATER USING PULSING ELECTROMAGNETIC FIELD

    Directory of Open Access Journals (Sweden)

    Ibragimova Ozoda

    2013-11-01

    Full Text Available ABSTRACT:  The paper deals with comparative analysis of existing expedients and devices of disinfecting water, spots ways of the solution and a new method of  water purification using electromagnetic field applied in a cross wise direction. ABSTRAK: Dalam operasi, analisis perbandingan dijalankan bagi menentukan  kesesuaian yang sedia ada dan alatan untuk menyahjangkit air. Dengan mengaplikasikan medan magnet lintang, penyelesaian masalah dikenal pasti dengan meningkatkan kemagnetan terhadap medan elektromagnet ke atas air.

  19. Antimicrobial Activity and Antibiotic Sensitivity of Three Isolates of Lactic Acid Bacteria From Fermented Fish Product, Budu

    Directory of Open Access Journals (Sweden)

    Liasi, S. A.

    2009-01-01

    Full Text Available Three isolates of lactic acid bacteria (LAB from the fermented food product, Budu, were identified as genus lactobacillus (Lactobacillus casei LA17, Lactobacillus plantarum LA22 and L. paracasei LA02, and the highest population was Lb. paracasei LA02. The antibacterial agent produced by the isolates inhibited the growth of a range of gram-positive and gram-negative microorganisms. Antimicrobial sensitivity test to 18 different types of antibiotic were evaluated using the disc diffusion method. Inhibition zone diameter was measured and calculated from the means of five determinations and expressed in terms of resistance or susceptibility. All the LAB isolates were resistant to colestin sulphate, streptomycin, amikacin, norfloxacin, nalidixic acid, mecillinam, sulphanethoxazole/ trimethoprim, kanamycin, neomycin, bacitracin and gentamycin but susceptible to erythromycin, penicillin G, chloramphenicol, tetracycline, ampicillin and nitrofurantion.

  20. Complex marine natural products as potential epigenetic and production regulators of antibiotics from a marine Pseudomonas aeruginosa

    Science.gov (United States)

    Marine microbes are capable of producing secondary metabolites for defense and competition. Factors exerting an impact on secondary metabolite production of microbial communities included bioactive natural products and co-culturing. These external influences may have practical applications such as ...

  1. Increasing antibiotic resistance in preservative-tolerant bacterial strains isolated from cosmetic products

    National Research Council Canada - National Science Library

    Orús, Pilar; Gomez-Perez, Laura; Leranoz, Sonia; Berlanga, Mercedes

    2015-01-01

    To ensure the microbiological quality, consumer safety and organoleptic properties of cosmetic products, manufacturers need to comply with defined standards using several preservatives and disinfectants...

  2. In Search of the E. coli Compounds that Change the Antibiotic Production Pattern of Streptomyces coelicolor During Inter-species Interaction.

    Science.gov (United States)

    Mavituna, Ferda; Luti, Khalid Jaber Kadhum; Gu, Lixing

    2016-08-01

    The aim of this work was to investigate the interaction between E.coli and Streptomyces coelicolor A3 (2) for the increased production of undecylprodigiosin and identify the E. coli actives mediating this inter-species interaction. The antibiotics of interest were the red-pigmented undecylprodigiosin and blue-pigmented actinorhodin. Pure cultures of S. coelicolor in a defined medium produced higher concentrations of actinorhodin compared to those of undecylprodigiosin. The latter however, is more important due to its immunosuppressive and antitumor properties. As a strategy to increase undecylprodigiosin production, we added separately, live cells and heat-killed cells of E. coli C600, and the cell-free supernatant of E. coli culture to S. coelicolor cultures in shake flasks. The interaction with live cells of E. coli altered the antibiotic production pattern and undecylprodigiosin production was enhanced by 3.5-fold compared to the pure cultures of S. coelicolor and actinorhodin decreased by 15-fold. The heat-killed cells of E. coli however, had no effect on antibiotic production. In all cases, growth and glucose consumption of S. coelicolor remained almost the same as those observed in the pure culture indicating that the changes in antibiotic production were not due to nutritional stress. Results with cell-free supernatant of E. coli culture indicated that the interaction between S. coelicolor and E. coli was mediated via diffusible molecule(s). Using a set of extraction procedures and agar-well diffusion bioassays, we isolated and preliminarily identified a class of compounds. For the preliminary verification, we added the compound which was the common chemical structural moiety in this class of compounds to the pure S. coelicolor cultures. We observed similar effects on antibiotic production as with the live E. coli cells and their supernatant indicating that this class of compounds secreted by E. coli indeed could act as actives during interspecies

  3. Diversity, distribution and quantification of antibiotic resistance genes in goat and lamb slaughterhouse surfaces and meat products.

    Science.gov (United States)

    Lavilla Lerma, Leyre; Benomar, Nabil; Knapp, Charles W; Correa Galeote, David; Gálvez, Antonio; Abriouel, Hikmate

    2014-01-01

    The distribution and quantification of tetracycline, sulfonamide and beta-lactam resistance genes were assessed in slaughterhouse zones throughout meat chain production and the meat products; this study represents the first to report quantitatively monitor antibiotic resistance genes (ARG) in goat and lamb slaughterhouse using a culture independent approach, since most studies focused on individual bacterial species and their specific resistance types. Quantitative PCR (qPCR) revealed a high prevalence of tetracycline resistance genes tetA and tetB in almost all slaughterhouse zones. Sulfonamide resistance genes were largely distributed, while beta-lactam resistance genes were less predominant. Statistical analysis revealed that resistant bacteria, in most cases, were spread by the same route in almost all slaughterhouse zones, except for tetB, blaCTX and blaTEM genes, which occurred in few zones as isolated 'hot spots.' The sum of all analyzed ARG indicated that slaughterhouse surfaces and end products act as reservoirs of ARG, mainly tet genes, which were more prevalent in slaughtering room (SR), cutting room (CR) and commercial meat products (MP). Resistance gene patterns suggest they were disseminated throughout slaughterhouse zones being also detected in commercial meat products, with significant correlations between different sampling zones/end products and total resistance in SR, CR and white room (WR) zones, and also refrigerator 4 (F4) and MP were observed. Strategically controlling key zones in slaughterhouse (SR, CR and WR) by adequate disinfection methods could strategically reduce the risks of ARG transmission and minimize the issues of food safety and environment contamination.

  4. Diversity, distribution and quantification of antibiotic resistance genes in goat and lamb slaughterhouse surfaces and meat products.

    Directory of Open Access Journals (Sweden)

    Leyre Lavilla Lerma

    Full Text Available The distribution and quantification of tetracycline, sulfonamide and beta-lactam resistance genes were assessed in slaughterhouse zones throughout meat chain production and the meat products; this study represents the first to report quantitatively monitor antibiotic resistance genes (ARG in goat and lamb slaughterhouse using a culture independent approach, since most studies focused on individual bacterial species and their specific resistance types. Quantitative PCR (qPCR revealed a high prevalence of tetracycline resistance genes tetA and tetB in almost all slaughterhouse zones. Sulfonamide resistance genes were largely distributed, while beta-lactam resistance genes were less predominant. Statistical analysis revealed that resistant bacteria, in most cases, were spread by the same route in almost all slaughterhouse zones, except for tetB, blaCTX and blaTEM genes, which occurred in few zones as isolated 'hot spots.' The sum of all analyzed ARG indicated that slaughterhouse surfaces and end products act as reservoirs of ARG, mainly tet genes, which were more prevalent in slaughtering room (SR, cutting room (CR and commercial meat products (MP. Resistance gene patterns suggest they were disseminated throughout slaughterhouse zones being also detected in commercial meat products, with significant correlations between different sampling zones/end products and total resistance in SR, CR and white room (WR zones, and also refrigerator 4 (F4 and MP were observed. Strategically controlling key zones in slaughterhouse (SR, CR and WR by adequate disinfection methods could strategically reduce the risks of ARG transmission and minimize the issues of food safety and environment contamination.

  5. Diversity, Distribution and Quantification of Antibiotic Resistance Genes in Goat and Lamb Slaughterhouse Surfaces and Meat Products

    Science.gov (United States)

    Lavilla Lerma, Leyre; Benomar, Nabil; Knapp, Charles W.; Correa Galeote, David; Gálvez, Antonio; Abriouel, Hikmate

    2014-01-01

    The distribution and quantification of tetracycline, sulfonamide and beta-lactam resistance genes were assessed in slaughterhouse zones throughout meat chain production and the meat products; this study represents the first to report quantitatively monitor antibiotic resistance genes (ARG) in goat and lamb slaughterhouse using a culture independent approach, since most studies focused on individual bacterial species and their specific resistance types. Quantitative PCR (qPCR) revealed a high prevalence of tetracycline resistance genes tetA and tetB in almost all slaughterhouse zones. Sulfonamide resistance genes were largely distributed, while beta-lactam resistance genes were less predominant. Statistical analysis revealed that resistant bacteria, in most cases, were spread by the same route in almost all slaughterhouse zones, except for tetB, blaCTX and blaTEM genes, which occurred in few zones as isolated ‘hot spots.’ The sum of all analyzed ARG indicated that slaughterhouse surfaces and end products act as reservoirs of ARG, mainly tet genes, which were more prevalent in slaughtering room (SR), cutting room (CR) and commercial meat products (MP). Resistance gene patterns suggest they were disseminated throughout slaughterhouse zones being also detected in commercial meat products, with significant correlations between different sampling zones/end products and total resistance in SR, CR and white room (WR) zones, and also refrigerator 4 (F4) and MP were observed. Strategically controlling key zones in slaughterhouse (SR, CR and WR) by adequate disinfection methods could strategically reduce the risks of ARG transmission and minimize the issues of food safety and environment contamination. PMID:25479100

  6. Validation approach for a fast and simple targeted screening method for 75 antibiotics in meat and aquaculture products using LC-MS/MS.

    Science.gov (United States)

    Dubreil, Estelle; Gautier, Sophie; Fourmond, Marie-Pierre; Bessiral, Mélaine; Gaugain, Murielle; Verdon, Eric; Pessel, Dominique

    2017-04-01

    An approach is described to validate a fast and simple targeted screening method for antibiotic analysis in meat and aquaculture products by LC-MS/MS. The strategy of validation was applied for a panel of 75 antibiotics belonging to different families, i.e., penicillins, cephalosporins, sulfonamides, macrolides, quinolones and phenicols. The samples were extracted once with acetonitrile, concentrated by evaporation and injected into the LC-MS/MS system. The approach chosen for the validation was based on the Community Reference Laboratory (CRL) guidelines for the validation of screening qualitative methods. The aim of the validation was to prove sufficient sensitivity of the method to detect all the targeted antibiotics at the level of interest, generally the maximum residue limit (MRL). A robustness study was also performed to test the influence of different factors. The validation showed that the method is valid to detect and identify 73 antibiotics of the 75 antibiotics studied in meat and aquaculture products at the validation levels.

  7. Effects of ionophores and antibiotics on in vitro hydrogen sulfide production, dry matter disappearance, and total gas production in cultures with a steam-flaked corn-based substrate with or without added sulfur.

    Science.gov (United States)

    Quinn, M J; May, M L; Hales, K E; DiLorenzo, N; Leibovich, J; Smith, D R; Galyean, M L

    2009-05-01

    Effects of 3 ionophores and 2 antibiotics on in vitro H(2)S production, IVDMD, total gas production, and VFA profile with or without added S were examined. In Exp. 1, ruminal fluid from 2 ruminally cannulated steers fed a steam-flaked corn-based diet (75% concentrate) without ionophore and antibiotics for 28 d before collection was used to inoculate in vitro cultures. Treatments were control (no ionophore or antibiotic), 3 ionophores (lasalocid sodium and monensin sodium at 5 mg/L or laidlomycin propionate at 1.65 mg/L), and 2 antibiotics (chlortetracycline hydrochloride at 5 mg/L and tylosin tartarate at 1.25 mg/L). Cultures also had 0 or 1.75 mg of S/L (from sodium sulfate). No S x ionophore-antibiotic treatment interactions were noted (P > 0.53) for IVDMD, total gas production, and H(2)S production. Hydrogen sulfide (mumol/g of fermentable DM) was increased (P ionophores or antibiotics (P > 0.18). On average, IVDMD (P = 0.05) was greater for ionophores than for antibiotics, whereas total gas production was less for ionophores than for control (P ionophore treatments when no S was added, but when S was added there were no differences (P > 0.20) in acetate, propionate, or acetate:propionate between ionophores and control (S x treatment interaction, P = 0.03). In Exp. 2, the effects of ionophore-antibiotic combinations with added S were examined using the same procedures as in Exp. 1. Treatments were control, monensin plus tylosin (MT), and lasalocid plus chlortetracycline (LCTC), with concentrations of the ionophores and antibiotics as in Exp. 1. No differences were observed among treatments for H(2)S production (P > 0.55). Treatments MT and LCTC tended (P = 0.06) to increase IVDMD and decreased (P = 0.02) gas production vs. control. Proportion of acetate (P = 0.01) and acetate:propionate (P ionophores and 2 antibiotics we evaluated did not affect production of H(2)S gas in an in vitro rumen culture system.

  8. Transcriptional regulation of the redD transcriptional activator gene accounts for growth-phase-dependent production of the antibiotic undecylprodigiosin in Streptomyces coelicolor A3(2)

    NARCIS (Netherlands)

    Takano, E.; Gramajo, H.C.; Strauch, E.; White, J.; Bibb, M.J.

    1992-01-01

    Transcription of redD, the activator gene required for production of the red-pigmented antibiotic undecylprodigiosin by Streptomyces coelicolor A3(2), showed a dramatic increase during the transition from exponential to stationary phase. The increase in redD expression was followed by transcription

  9. Halogenated furanones from the red alga, Delisea pulchra, inhibit carbapenem antibiotic synthesis and exoenzyme virulence factor production in the phytopathogen Erwinia carotovora

    DEFF Research Database (Denmark)

    Manefield, M.; Welch, M.; Givskov, Michael Christian

    2001-01-01

    The plant pathogen Erwinia carotovora regulates expression of virulence factors and antibiotic production via an N-3- oxohexanoyl-L-homoserine lactone (3-oxo-C6-HSL) dependent quorum sensing mechanism. The marine alga Delisea pulchra produces halogenated furanones known to antagonise 3-oxo-C6-HSL...

  10. Antibiotic Susceptibility Profiles of Listeria monocytogenes Strains Isolated from Food Products and Clinical Samples

    Directory of Open Access Journals (Sweden)

    Caplan Marius Eduard

    2014-06-01

    Full Text Available Listeria monocytogenes are o distribuţie ubiquitară în natură şi poate contamina produsele alimentare de origine animală, provocând infecţii severe la om. Până în prezent există foarte puține date cu privire la profilurile de rezistenţă ale tulpinilor circulante în România. Scopul acestui studiu a fost determinarea pattern-urilor de rezistenţă la antibiotice ale unor tulpini de L. monocytogenes (n=37 izolate din produse alimentare de origine animală şi din probe clinice. Probele din alimente (carne şi produse lactate, au fost colectate în perioada 2009-2013. Probele clinice au fost recoltate de la pacienţi cu septicemie, meningită/meningo-encefalită, cazuri de avort spontan şi nou-născuţi, spitalizaţi în perioada Aprilie 2010 - Aprilie 2013 în trei Instituţii Medicale din Bucureşti: Spitalul Elias, Spitalul Victor Babes si Institutul Naţional de Boli Infecţioase (INBI Matei Bals. Toate tulpinile testate au prezentat rezistenţă la cefalosporine şi acidul nalidixic; o tulpină izolată din melci fierţi a fost rezistentă la Trimetoprim/sulfametoxazol. Rezistenţa unora dintre tulpinile analizate la ampicilina, antibiotic de elecţie pentru terapia infecţiilor cauzate de L. monocytogenes, subliniază necesitatea testării in vitro a sensibilitatii la antibiotice a fiecarui izolat clinic pentru a stabili eficienţa diferitelor antibiotice, precum şi a unor studii epidemiologice extinse în scopul stabilirii profilurilor de rezistenţă ale tulpinilor de L. monocytogenes circulante în ţara noastră.

  11. ANTIBIOTIC RESISTANCE OF ENTEROBACTERIACEAE GENERA AND SALMONELLA SPP., SALMONELLA ENTERICA SER. TYPHIMURIUM AND ENTERITIDIS ISOLATED FROM MILK, CHEESE AND OTHER DAIRY PRODUCTS FROM CONVENTIONAL FARM IN SLOVAKIA

    Directory of Open Access Journals (Sweden)

    Simona Kunová

    2011-08-01

    Full Text Available Antibiotic resistance was investigated in 67 samples of Enterobacteriaceae genera isolates from milk, cheese and other dairy products in this work. The samples were obtained from conventional farms in Slovakia. Four samples of isolates were positive for Salmonella spp., Salmonella enterica ser. typhimurium and enteritidis. A great proportion of resistant strain from Enterobacteriaceae genera was found. There was detected a high resistance in milk samples to ampicillin (57.14%, to streptomycin and tetracycline (14.28%, to chloramphenicol (9.52%. Bacteria from the cheese samples were resistant to ampicillin (84.0%, to tetracycline (24.0%. In the samples of other dairy products was found resistance to ampicillin (66.66%, to tetracycline (52.38% and to streptomycin (14.28%. Among all samples observed, it was found resistance to ampicillin (69.26%, tetracycline (30.22%, streptomycin (9.52% and to chloramphenicol (3.17%. Resistance to other antibiotics was not detected. From all observed samples we detected Salmonella spp. in 5.97 %, Salmonella spp. was found in dairy samples in 19.04 %. Antibiotic resistance was investigated in 13 colonies of Salmonella spp. as well. The highest resistance was to tetracycline (30.76 %, ampicillin and tigecycline (23.07 %, to piperacillin (15.38 % and chloramphenicol (7.69 %. Resistance to the other monitored antibiotics was not detected. High number of antibiotic resistant Enterobacteriaceae genera and Salmonella spp. was found in milk, cheese and other dairy products from conventional breeding and it is indicating the need for prudent drugs using to diminish development and to avoid spread of antibiotic resistance.

  12. The Impact of Efflux Pump Inhibitors on the Activity of Selected Non-Antibiotic Medicinal Products against Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Agnieszka E. Laudy

    2017-01-01

    Full Text Available The potential role of non-antibiotic medicinal products in the treatment of multidrug-resistant Gram-negative bacteria has recently been investigated. It is highly likely that the presence of efflux pumps may be one of the reasons for the weak activity of non-antibiotics, as in the case of some non-steroidal anti-inflammatory drugs (NSAIDs, against Gram-negative rods. The activity of eight drugs of potential non-antibiotic activity, active substance standards, and relevant medicinal products were analysed with and without of efflux pump inhibitors against 180 strains of five Gram-negative rod species by minimum inhibitory concentration (MIC value determination in the presence of 1 mM MgSO4. Furthermore, the influence of non-antibiotics on the susceptibility of clinical strains to quinolones with or without PAβN (Phe-Arg-β-naphthylamide was investigated. The impacts of PAβN on the susceptibility of bacteria to non-antibiotics suggests that amitriptyline, alendronate, nicergoline, and ticlopidine are substrates of efflux pumps in Gram-negative rods. Amitriptyline/Amitriptylinum showed the highest direct antibacterial activity, with MICs ranging 100–800 mg/L against all studied species. Significant decreases in the MIC values of other active substances (acyclovir, atorvastatin, and famotidine tested with pump inhibitors were not observed. The investigated non-antibiotic medicinal products did not alter the MICs of quinolones in the absence and in the presence of PAβN to the studied clinical strains of five groups of species.

  13. [Effect of the gene for bacterial hemoglobin vhb on the effectiveness of the process of Escherichia coli-Streptomyces interspecies conjugation and production of antibiotics in streptomycetes].

    Science.gov (United States)

    Tabakov, V Iu; Emel'ianova, L K; Antonova, S V; Voeĭkova, T A

    2001-03-01

    The bacterial hemoglobin vhb gene was cloned from sliding bacterium Vitreoscilla sp. as an element of the system ensuring survival of this microorganism in an environment that contains insufficient amount of oxygen. The vhb gene was transferred from Escherichia coli to some Streptomyces strains, producers of antibiotics, by the method of intergeneric conjugation using conjugative-integrative plasmid vectors pIH1 and pCH2. The stability of plasmid DNA inheritance was analyzed in the genomes of exconjugants. A positive effect of the vhb gene on processes of conjugation and antibiotic production in a number of examined strains was shown.

  14. Reducing the variability of antibiotic production in Streptomyces by cultivation in 24-square deepwell plates

    DEFF Research Database (Denmark)

    Siebenberg, S.; Bapat, Prashant Madhusudhan; Eliasson Lantz, Anna

    2010-01-01

    of time. Originally, novobiocin titers in the deepwell plate (5-12 mg l(-1)) were lower than in Erlenmeyer flasks (24 mg Optimization of the inoculation procedure as well as addition of a siloxylated ethylene oxide/propylene oxide copolymer, acting as oxygen carrier, to the production medium increased...

  15. Impact of "raised without antibiotics" beef cattle production practices on occurrences of antimicrobial resistance

    Science.gov (United States)

    The specific antimicrobial resistance (AMR) decreases that can be expected from reducing antimicrobial (AM) use in U.S. beef production have not been defined. To address this data gap, feces were recovered from 36 lots of “raised without antibiotics” (RWA) and 36 lots of “conventional” (CONV) beef c...

  16. TARSyn: Tunable Antibiotic Resistance Devices Enabling Bacterial Synthetic Evolution and Protein Production

    DEFF Research Database (Denmark)

    Rennig, Maja; Martinez, Virginia; Mirzadeh, Kiavash

    2018-01-01

    Evolution can be harnessed to optimize synthetic biology designs. A prominent example is recombinant protein production-a dominating theme in biotechnology for more than three decades. Typically, a protein coding sequence (cds) is recombined with genetic elements, such as promoters, ribosome bind...

  17. Substrate uptake, phosphorus repression, and effect of seed culture on glycopeptide antibiotic production

    DEFF Research Database (Denmark)

    Maiti, Soumen K.; Singh, Kamaleshwar P.; Eliasson Lantz, Anna

    2010-01-01

    may experience catabolite repression by one or more of the substrates. Availability of reliable process models is a key bottleneck in optimization of such processes. Here we present a structured kinetic model to describe the growth, substrate uptake and product formation for the glycopeptide...

  18. Low molecular weight protein tyrosine phosphatases control antibiotic production in Streptomyces coelicolor A3(2)

    DEFF Research Database (Denmark)

    Sohoni, Sujata Vijay; Lieder, Sarah; Bapat, Prashant Madhusudhan

    2014-01-01

    Streptomyces coelicolor A3(2) possesses a low molecular weight protein tyrosine phosphatase (LMW-PTP),PtpA, that affects the production of undecylprodigionsin (RED) and actinorhodin (ACT). In this study we identifiedanother LMW-PTP called sco3700. Tyrosine phosphatase activity of the purified Sco...

  19. Enhanced Production of a Novel Cyclic Hexapeptide Antibiotic (NW-G01 by Streptomyces alboflavus 313 Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Wenjun Wu

    2012-04-01

    Full Text Available NW-G01, produced by Streptomyces alboflavus 313, is a novel cyclic hexapeptide antibiotic with many potential applications, including antimicrobial activity and antitumor agents. This study developed a system for optimizing medium components in order to enhance NW-G01 production. In this study, Plackett-Burman design (PBD was used to find the key ingredients of medium components, and then response surface methodology (RSM was implemented to determine their optimal concentrations. The results of PBD revealed that the crucial ingredients related to the production of NW-G01 were (NH42SO4, peptone and CaCO3. A prediction model has been built in the experiments of central composite design and response surface methodology, and its validation has been further verified. The optimal medium composition was determined (g/L: corn starch 15, glucose 15, peptone 3.80, (NH42SO4 0.06, NaCl 1.5, CaCO3 1.30, MgSO4·7H2O 0.015, K2HPO4·3H2O 0.015, MnCl2·4H2O 0.015, FeSO4·7H2O 0.015, and ZnSO4·7H2O 0.015. Compared with NW-G01 production (5.707 mg/L in non-optimized fermentation medium, the production of NW-G01 (15.564 mg/L in optimized fermentation medium had a 2.73-fold increase.

  20. Monitoring and determination of sulfonamide antibiotics (sulfamethoxydiazine, sulfamethazine, sulfamethoxazole and sulfadiazine) in imported Pangasius catfish products in Thailand using liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Jansomboon, Worawat; Boontanon, Suwanna Kitpati; Boontanon, Narin; Polprasert, Chongrak; Thi Da, Chau

    2016-12-01

    This research aimed to monitor the concentrations of sulfamethoxydiazine (SMD), sulfamethazine (SMT), sulfamethoxazole (SMX) and sulfadiazine (SDZ) in imported Pangasius catfish products in Thailand. The residues of the four sulfonamides (SAs) were analyzed by extraction process and liquid chromatography coupled with tandem mass spectrometry. The highest concentrations found were 10.97ng/g for SMD, 6.23ng/g for SMT, 11.13ng/g for SDZ and 245.91ng/g for SMX, which was higher than the European Union (EU) standard (100ng/g). Moreover, all samples contaminated with SMX also contained SMT, indicating that more than one antibiotic was used for production in the country of origin. Because Thai standards for antibiotics in food have not been completely set, all contaminated discovered would not be considered to be an illegal food, in which antibiotic residues may affect human health in the long term. Therefore, antibiotic residues in Pangasius catfish products should be continually regulated and monitored. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Simultaneous production of alkaline lipase and protease by antibiotic and heavy metal tolerant Pseudomonas aeruginosa.

    Science.gov (United States)

    Bisht, Deepali; Yadav, Santosh Kumar; Gautam, Pallavi; Darmwal, Nandan Singh

    2013-09-01

    An efficient bacterial strain capable of simultaneous production of lipase and protease in a single production medium was isolated. Thirty six bacterial strains, isolated from diverse habitats, were screened for their lipolytic and proteolytic activity. Of these, only one bacterial strain was found to be lipase and protease producer. The 16S rDNA sequencing and phylogenetic analyses revealed that strain (NSD-09) was in close identity to Pseudomonas aeruginosa. The maximum lipase (221.4 U/ml) and protease (187.9 U/ml) activities were obtained after 28 and 24 h of incubation, respectively at pH 9.0 and 37 °C. Castor oil and wheat bran were found to be the best substrate for lipase and protease production, respectively. The strain also exhibited high tolerance to lead (1450 µg/ml) and chromium (1000 µg/ml) in agar plates. It also showed tolerance to other heavy metals, such as Co(+2) , Zn(+2) , Hg(+2) , Ni(+2) and Cd(+2) . Therefore, this strain has scope for tailing bioremediation. Presumably, this is the first attempt on P. aeruginosa to explore its potential for both industrial and environmental applications. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. The multifaceted roles of antibiotics and antibiotic resistance in nature

    Directory of Open Access Journals (Sweden)

    Saswati eSengupta

    2013-03-01

    Full Text Available Antibiotics are chemotherapeutic agents, which have been a very powerful tool in the clinical management of bacterial diseases since the 1940s. However, benefits offered by these magic bullets have been substantially lost in subsequent days following the widespread emergence and dissemination of antibiotic resistant strains. While it is obvious that excessive and imprudent use of antibiotics significantly contributes to the emergence of resistant strains, antibiotic-resistance is also observed in natural bacteria of remote places unlikely to be impacted by human intervention. Both antibiotic biosynthetic genes and resistance-conferring genes have been known to evolve billions of years ago, long before clinical use of antibiotics. Hence it appears that antibiotics and antibiotics resistance determinants have some other roles in nature, which often elude our attention because of overemphasis on the therapeutic importance of antibiotics and the crisis imposed by the antibiotic-resistance in pathogens. In the natural milieu, antibiotics are often found to be present in subinhibitory concentrations acting as signalling molecules supporting quorum sensing and biofilm formation. They also play an important role in the production of virulence factors and influence host-parasite interactions (e.g., phagocytosis, adherence to the target cell and so on. The evolutionary and ecological aspects of antibiotics and antibiotic-resistance in the naturally occurring microbial community are little understood. Therefore, the actual role of antibiotics in nature warrants in-depth investigations. Studies on such an intriguing behaviour of the microorganisms promise insight into the intricacies of the microbial physiology and are likely to provide some lead in controlling the emergence and subsequent dissemination of antibiotic resistance. This article highlights some of the recent findings on the role of antibiotics and genes that confer resistance to antibiotics in

  3. Expedient Syntheses of Neutral and Cationic Au(I)–NHC Complexes

    KAUST Repository

    Veenboer, Richard M. P.

    2017-09-08

    The synthesis and isolation of gold(I) precatalysts often requires the generation of several isolable intermediates as well as numerous purification steps. New protocols for the expedient synthesis of neutral [Au(OH)(NHC)] and [Au(CH2COCH3)(NHC)] species from [AuCl(NHC)] or [AuCl(DMS)] precursors bearing a variety of N-heterocyclic carbene (NHC) ligands are presented. These methods can be employed in a telescoping manner for the synthesis of catalytically relevant [Au(NTf2)(NHC)] and [Au(NHC)(NCCH3)][BF4] complexes. These attractive methods are straightforward and practical leading to various complexes in high isolated yields and purity.

  4. A probabilistic approach to assess antibiotic resistance development risks in environmental compartments and its application to an intensive aquaculture production scenario

    NARCIS (Netherlands)

    Rico, Andreu; Jacobs, Rianne; Brink, Van den Paul J.; Tello, Alfredo

    2017-01-01

    Estimating antibiotic pollution and antibiotic resistance development risks in environmental compartments is important to design management strategies that advance our stewardship of antibiotics. In this study we propose a modelling approach to estimate the risk of antibiotic resistance development

  5. A probabilistic approach to assess antibiotic resistance development risks in environmental compartments and its application to an intensive aquaculture production scenario.

    NARCIS (Netherlands)

    Rico, Andreu; Jacobs, Rianne; Van den Brink, Paul J; Tello, Alfredo

    2017-01-01

    Estimating antibiotic pollution and antibiotic resistance development risks in environmental compartments is important to design management strategies that advance our stewardship of antibiotics. In this study we propose a modelling approach to estimate the risk of antibiotic resistance development

  6. Biosensors, antibiotics and food.

    Science.gov (United States)

    Virolainen, Nina; Karp, Matti

    2014-01-01

    Antibiotics are medicine's leading asset for fighting microbial infection, which is one of the leading causes of death worldwide. However, the misuse of antibiotics has led to the rapid spread of antibiotic resistance among bacteria and the development of multiple resistant pathogens. Therefore, antibiotics are rapidly losing their antimicrobial value. The use of antibiotics in food production animals is strictly controlled by the European Union (EU). Veterinary use is regulated to prevent the spread of resistance. EU legislation establishes maximum residue limits for veterinary medicinal products in foodstuffs of animal origin and enforces the establishment and execution of national monitoring plans. Among samples selected for monitoring, suspected noncompliant samples are screened and then subjected to confirmatory analysis to establish the identity and concentration of the contaminant. Screening methods for antibiotic residues are typically based on microbiological growth inhibition, whereas physico-chemical methods are used for confirmatory analysis. This chapter discusses biosensors, especially whole-cell based biosensors, as emerging screening methods for antibiotic residues. Whole-cell biosensors can offer highly sensitive and specific detection of residues. Applications demonstrating quantitative analysis and specific analyte identification further improve their potential as screening methods.

  7. Influence of zinc on biogas production and antibiotic resistance gene profiles during anaerobic digestion of swine manure.

    Science.gov (United States)

    Zhang, Ranran; Wang, Xiaojuan; Gu, Jie; Zhang, Yajun

    2017-11-01

    This study determined the accumulated biogas, methane content, and absolute abundances (AAs) of 14 common antibiotic resistance genes (ARGs) and two integrons during the anaerobic digestion of swine manure for 52days with different amounts of added zinc. The accumulated biogas increased by 51.2% and 56.0% with 125mgL-1 (L) and 1250mgL-1 (H) zinc, respectively, compared with the control with no added zinc (CK), but there was no significant difference between L and H. Compared with CK, excluding tetW and tetC, all the other ARGs detected in this study increased in the L and H reactors. However, the low concentration of zinc (L reactor) caused greater increases in the AAs of ARGs in the AD products. Redundancy analysis showed that NO3-N and bio-zinc significantly explained the changes in genes, where they accounted for 60.9% and 20.3% of the total variation in the environmental factors, respectively. Copyright © 2017. Published by Elsevier Ltd.

  8. Streptovirudins, new antibiotics with antibacterial and antiviral activity. I. Culture taxonomy, fermentation and production of streptovirudin complex.

    Science.gov (United States)

    Thrum, H; Eckardt, K; Bradler, G; Fügner, R; Tonew, E; Tonew, M

    1975-07-01

    A new antibiotic complex has been isolated from cultures of Streptomyces strain No. JA 10124. On the basis of taxonomic studies, the producing microorganism is described as Streptomyces griseoflavus (Krainsky, 1914) Waksman et Henrici, 1948, subsp. thuringiensis subsp. nov., type strain JA 10124. The antibiotic complex, designated as streptovirudin, was isolated from extracts of both mycelium and culture filtrate. It is a white amorphous material which consists of ten closely related components including streptovirudins A, B, C, D and E. The streptovirudin complex exhibits antibiotic activity against Gram-positive bacteria, mycobacteria, and various DNA- and RNA-viruses.

  9. 9 CFR 114.10 - Antibiotics as preservatives.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Antibiotics as preservatives. 114.10... BIOLOGICAL PRODUCTS § 114.10 Antibiotics as preservatives. Antibiotics are authorized for use as... section. (a) When an antibiotic or combination of antibiotics, with or without a fungistat is to be used...

  10. History of Antibiotics Research.

    Science.gov (United States)

    Mohr, Kathrin I

    2016-01-01

    For thousands of years people were delivered helplessly to various kinds of infections, which often reached epidemic proportions and have cost the lives of millions of people. This is precisely the age since mankind has been thinking of infectious diseases and the question of their causes. However, due to a lack of knowledge, the search for strategies to fight, heal, and prevent the spread of communicable diseases was unsuccessful for a long time. It was not until the discovery of the healing effects of (antibiotic producing) molds, the first microscopic observations of microorganisms in the seventeenth century, the refutation of the abiogenesis theory, and the dissolution of the question "What is the nature of infectious diseases?" that the first milestones within the history of antibiotics research were set. Then new discoveries accelerated rapidly: Bacteria could be isolated and cultured and were identified as possible agents of diseases as well as producers of bioactive metabolites. At the same time the first synthetic antibiotics were developed and shortly thereafter, thousands of synthetic substances as well as millions of soil borne bacteria and fungi were screened for bioactivity within numerous microbial laboratories of pharmaceutical companies. New antibiotic classes with different targets were discovered as on assembly line production. With the beginning of the twentieth century, many of the diseases which reached epidemic proportions at the time-e.g., cholera, syphilis, plague, tuberculosis, or typhoid fever, just to name a few, could be combatted with new discovered antibiotics. It should be considered that hundred years ago the market launch of new antibiotics was significantly faster and less complicated than today (where it takes 10-12 years in average between the discovery of a new antibiotic until the launch). After the first euphoria it was quickly realized that bacteria are able to develop, acquire, and spread numerous resistance mechanisms

  11. High resolution mass spectrometry in the identification of transformation products and metabolites from β-lactam antibiotics in thermally treated milk.

    Science.gov (United States)

    Junza, A; Montané, A; Barbosa, J; Minguillón, C; Barrón, D

    2014-11-14

    Antibiotics such as β-lactam derivatives (penicillins and cephalosporins) are frequently used in veterinary medicine. The presence of these antibiotics together with their metabolites and/or products produced in subsequent treatments at which milk is submitted (sterilization, pasteurization), may be responsible for bacterial resistance, allergy and/or toxicity on sensitive individuals. In this study, liquid chromatography coupled with high resolution mass spectrometry (LC-HRMS) is used to identify transformation products (TPs) from four β-lactam antibiotics (amoxicillin (AMOX), cephapirin (PIR), ceftiofur (TIO) and penicillin G (PENG)) in thermally treated cow milk. In addition, milk from cows medicated with PENG has also been analogously treated and studied. The detected TPs come mainly from hydrolysis and decarboxylation reactions. Products more strongly degraded respect to parent compounds (of lower molecular weight) were obtained after treating milk at higher temperatures. Products identified in milk from cows medicated with PENG have been classified as TPs when coming from chemical/thermal degradation, and metabolites when resulting from the biological drug metabolism. While TPs are the result of hydrolysis and decarboxylation processes, as already indicated, an enzymatic conjugation with amino acids is suggested to be involved in the formation of metabolites. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Antibiotics and Resistance: Glossary

    Science.gov (United States)

    ... antibiotic resistance? When and how to take antibiotics Antibacterial agents Bioterrorism & stockpiling antibiotics The Cost of Resistance Science of Resistance Ecology Antibiotics in Agriculture Antibacterial ...

  13. Projecto - XIV Expedição Científica do Departamento de Biologia - Santa Maria 2009.

    OpenAIRE

    Tavares, João; Furtado, Duarte

    2009-01-01

    XIV Expedição Científica do Departamento de Biologia - Santa Maria 2009 (Projecto). Na XIV Expedição Científica do DB à ilha de Santa Maria, pretendemos desenvolver uma série de estudos para aprofundar o conhecimento sobre a vida e o ambiente, com planos de trabalho diversos, dos quais destacamos: (i) Estudo da Flora da ilha de Santa Maria: actualização do catálogo das plantas vasculares, recolha de sementes, dados fenológicos e imagens digitais a integrar o Herbário Virtual dos Açores; (i...

  14. Prescribing Antibiotics

    DEFF Research Database (Denmark)

    Pedersen, Inge Kryger; Jepsen, Kim Sune

    2018-01-01

    The medical professions will lose an indispensable tool in clinical practice if even simple infections cannot be cured because antibiotics have lost effectiveness. This article presents results from an exploratory enquiry into “good doctoring” in the case of antibiotic prescribing at a time when...

  15. Zinc Improves Biocontrol of Fusarium Crown and Root Rot of Tomato by Pseudomonas fluorescens and Represses the Production of Pathogen Metabolites Inhibitory to Bacterial Antibiotic Biosynthesis.

    Science.gov (United States)

    Duffy, B K; Défago, G

    1997-12-01

    ABSTRACT Crown and root rot of tomato caused by Fusarium oxysporum f. sp. radicis-lycopersici is an increasing problem in Europe, Israel, Japan, and North America. The biocontrol agent Pseudomonas fluorescens strain CHA0 provides only moderate control of this disease. A one-time amendment of zinc EDTA at 33 mug of Zn(2+)/ml to hydroponic nutrient solution in soilless rockwool culture did not reduce disease when used alone, but did reduce disease by 25% in the presence of CHA0. In in vitro studies with the pathogen, zinc at concentrations as low as 10 mug/ml abolished production of the phytotoxin fusaric acid, a Fusarium pathogenicity factor, and increased production of microconidia over 100-fold, but reduced total biomass. Copper EDTA at 33 mug of Cu(2+)/ml had a similar effect as zinc on the pathogen in vitro; it reduced disease when used alone, and increased the biocontrol activity of CHA0 in soilless culture. Ammonium-molybdate neither improved the biocontrol activity of CHA0 nor affected production of fusaric acid or microconidia. Strain CHA0 did not degrade fusaric acid. Fusaric acid at concentrations as low as 0.12 mug/ml repressed production by CHA0 of the antibiotic 2,4-diacetylphloroglucinol, a key factor in the biocontrol activity of this strain. Production of pyoluteorin by CHA0 was also reduced, but production of hydrogen cyanide and protease was not affected, suggesting that fusaric acid affects biosynthesis at a regulatory level downstream of gacA and apdA genes. Fusaric acid did not affect the recovery of preformed antibiotics nor did it affect bacterial growth even at concentrations as high as 200 mug/ml. When microbial meta-bolite production was measured in the rockwool bioassay, zinc amendments reduced fusaric acid production and enhanced 2,4-diacetylphloro-glucinol production. We suggest that zinc, which did not alleviate the repression of antibiotic biosynthesis by fusaric acid, improved biocontrol activity by reducing fusaric acid production by

  16. Antibiotic alternatives: the substitution of antibiotics in animal husbandry?

    Science.gov (United States)

    Cheng, Guyue; Hao, Haihong; Xie, Shuyu; Wang, Xu; Dai, Menghong; Huang, Lingli; Yuan, Zonghui

    2014-01-01

    It is a common practice for decades to use of sub-therapeutic dose of antibiotics in food-animal feeds to prevent animals from diseases and to improve production performance in modern animal husbandry. In the meantime, concerns over the increasing emergence of antibiotic-resistant bacteria due to the unreasonable use of antibiotics and an appearance of less novelty antibiotics have prompted efforts to develop so-called alternatives to antibiotics. Whether or not the alternatives could really replace antibiotics remains a controversial issue. This review summarizes recent development and perspectives of alternatives to antibiotics. The mechanism of actions, applications, and prospectives of the alternatives such as immunity modulating agents, bacteriophages and their lysins, antimicrobial peptides, pro-, pre-, and synbiotics, plant extracts, inhibitors targeting pathogenicity (bacterial quorum sensing, biofilm, and virulence), and feeding enzymes are thoroughly discussed. Lastly, the feasibility of alternatives to antibiotics is deeply analyzed. It is hard to conclude that the alternatives might substitute antibiotics in veterinary medicine in the foreseeable future. At the present time, prudent use of antibiotics and the establishment of scientific monitoring systems are the best and fastest way to limit the adverse effects of the abuse of antibiotics and to ensure the safety of animal-derived food and environment.

  17. Antibiotic Alternatives: The Substitution of Antibiotics in Animal Husbandry?

    Directory of Open Access Journals (Sweden)

    Guyue eCheng

    2014-05-01

    Full Text Available It is a common practice for decades to use of sub-therapeutic dose of antibiotics in food-animal feeds to prevent animals from diseases and to improve production performance in modern animal husbandry. In the meantime, concerns over the increasing emergence of antibiotic-resistant bacteria due to the unreasonable use of antibiotics and an appearance of less novelty antibiotics have prompted efforts to develop so-called alternatives to antibiotics. Whether or not the alternatives could relly replace antibiotics remains a controversial issue. This review summarizes recent development and perspectives of alternatives to antibiotics. The mechanism of actions, applications, and prospectives of the alternatives such as immunity modulating agents, bacteriophages and their lysins, antimicrobial peptides, pro-, pre- and synbiotics, plant extracts, inhibitors targeting pathogenicity (bacterial quorum sensing, biofilm and virulence, and feeding enzymes are thoroughly discussed. Lastly, the feasibility of alternatives to antibiotics is deeply analyzed. It is hard to conclude that the alternatives might substitute antibiotics in veterinary medicine in the foreseeable future. At the present time, prudent use of antibiotics and the establishment of scientific monitoring systems are the best and fastest way to limit the adverse effects of the abuse of antibiotics and to ensure the safety of animal-derived food and environment.

  18. Correlation between antibiotic and biocide resistance in mesophilic and psychrotrophic Pseudomonas spp. isolated from slaughterhouse surfaces throughout meat chain production.

    Science.gov (United States)

    Lavilla Lerma, Leyre; Benomar, Nabil; Casado Muñoz, María del Carmen; Gálvez, Antonio; Abriouel, Hikmate

    2015-10-01

    The aim of this study was to evaluate biocide susceptibility in mesophilic and psychrotrophic pseudomonads isolated from surfaces of a goat and lamb slaughterhouse, which was representative of the region. To determine biocide resistance in pseudomonads, we determined for the first time the epidemiological cut-off values (ECOFFs) of benzalkonium, cetrimide, chlorhexidine, hexachlorophene, P3 oxonia, polyhexamethylene guanidine hydrochloride (PHMG), topax 66 and triclosan being generally very similar in different Pseudomonas spp. with some exceptions. Thus, resistance of pseudomonads was mainly shown to triclosan, and in lesser extent to cetrimide and benzalkonium chloride depending on the species, however they were highly susceptible to industrial formulations of biocides. By means of statistical analysis, positive correlations between antibiotics, biocides and both antimicrobials in pseudomonads were detected suggesting a co- or cross resistance between different antimicrobials in goat and lamb slaughterhouse environment. Cross-resistance between biocides and antibiotics in pseudomonads were especially detected between PHMG or triclosan and different antibiotics depending on the biocide and the population type. Thus, the use of those biocides as disinfectant in slaughterhouse zones must be carefully evaluated because of the selection pressure effect of antimicrobials on the emergence of resistant bacteria which could be spread to the consumer. It is noteworthy that specific industrial formulations such as topax 66 and oxonia P3 showed few correlations with antibiotics (none or 1-2 antibiotics) which should be taken into consideration for disinfection practices in goat and lamb slaughterhouse. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Antibiotic Therapy for Acute Infiltrate-Complicated Calculous Cholecystitis

    Directory of Open Access Journals (Sweden)

    Yu. A. Nesterenko

    2007-01-01

    Full Text Available Objective: to summarize the results of treatment in 442 patients of various ages with acute calculous cholecystitis complicated by a compact perivesical infiltrate.Materials and methods. Bile from all the patients was bacteriologically studied. The implication of various antibiotics in limiting perivesical fat inflammation was determined.Results. The importance of decompressive treatments for complicated calculous cholecystitis has been ascertained. The advantages of microcholecystostomy have been revealed. There is evidence that it is expedient to use third-forth-generation cephalosporins, fluoroquinolones, and dioxidine in the combined treatment of destructive calculous cholecystitis complicated by an infiltrate. 

  20. Forgotten antibiotics

    DEFF Research Database (Denmark)

    Pulcini, Céline; Bush, Karen; Craig, William A

    2012-01-01

    available in fewer than 20 of 38 countries. Economic motives were the major cause for discontinuation of marketing of these antibiotics. Fourteen of 33 antibiotics are potentially active against either resistant Gram-positive or Gram-negative bacteria. Urgent measures are then needed to ensure better...... disease specialists in Europe, the United States, Canada, and Australia. An international expert panel selected systemic antibacterial drugs for their potential to treat infections caused by resistant bacteria or their unique value for specific criteria. Twenty-two of the 33 selected antibiotics were...

  1. Cephamycins, a New Family of β-Lactam Antibiotics I. Production by Actinomycetes, Including Streptomyces lactamdurans sp. n1

    Science.gov (United States)

    Stapley, E. O.; Jackson, M.; Hernandez, S.; Zimmerman, S. B.; Currie, S. A.; Mochales, S.; Mata, J. M.; Woodruff, H. B.; Hendlin, D.

    1972-01-01

    A number of actinomycetes isolated from soil were found to produce one or more members of a new family of antibiotics, the cephamycins, which are structurally related to cephalosporin C. The cephamycins were produced in submerged fermentation in a wide variety of media by one or more of eight different species of Streptomyces, including a newly described species, S. lactamdurans. These antibiotics exhibit antibacterial activity against a broad spectrum of bacteria which includes many that are resistant to the cephalosporins and penicillins. PMID:4790552

  2. Safely coupling livestock and crop production systems: how rapidly do antibiotic resistance genes dissipate in soil following a commercial application of swine or dairy manure?

    Science.gov (United States)

    Marti, Romain; Tien, Yuan-Ching; Murray, Roger; Scott, Andrew; Sabourin, Lyne; Topp, Edward

    2014-05-01

    Animal manures recycled onto crop production land carry antibiotic-resistant bacteria. The present study evaluated the fate in soil of selected genes associated with antibiotic resistance or genetic mobility in field plots cropped to vegetables and managed according to normal farming practice. Referenced to unmanured soil, fertilization with swine or dairy manure increased the relative abundance of the gene targets sul1, erm(B), str(B), int1, and IncW repA. Following manure application in the spring of 2012, gene copy number decayed exponentially, reaching background levels by the fall of 2012. In contrast, gene copy number following manure application in the fall of 2012 or spring of 2013 increased significantly in the weeks following application and then declined. In both cases, the relative abundance of gene copy numbers had not returned to background levels by the fall of 2013. Overall, these results suggest that under conditions characteristic of agriculture in a humid continental climate, a 1-year period following a commercial application of raw manure is sufficient to ensure that an additional soil burden of antibiotic resistance genes approaches background. The relative abundance of several gene targets exceeded background during the growing season following a spring application or an application done the previous fall. Results from the present study reinforce the advisability of treating manure prior to use in crop production systems.

  3. Bacteriocin production, antibiotic susceptibility and prevalence of haemolytic and gelatinase activity in faecal lactic acid bacteria isolated from healthy Ethiopian infants.

    Science.gov (United States)

    Birri, Dagim Jirata; Brede, Dag Anders; Tessema, Girum Tadesse; Nes, Ingolf F

    2013-02-01

    The objective of this study was to characterise lactic acid bacteria (LAB) isolated from faecal samples of healthy Ethiopian infants, with emphasis on bacteriocin production and antibiotic susceptibility. One hundred fifty LAB were obtained from 28 healthy Ethiopian infants. The isolates belonged to Lactobacillus (81/150), Enterococcus (54/150) and Streptococcus (15/150) genera. Lactobacillus species were more abundant in the breast-fed infants while Enterococcus dominated the mixed-fed population. Bacteriocin-producing LAB species were isolated from eight of the infants. Many different bacteriocins were identified, including one new bacteriocin from Streptococcus salivarius, avicin A (class IIa) from Enterococcus avium, one class IIa bacteriocin from Enterococcus faecalis strains, one unknown bacteriocin from E. faecalis and two unknown bacteriocins from Lactobacillus fermentum strains and the two-peptide gassericin T from Lactobacillus gasseri isolate. Susceptibility tests performed for nine antibiotics suggest that some lactobacilli might have acquired resistance to erythromycin (3 %) and tetracycline (4 %) only. The streptococci were generally antibiotic sensitive except for penicillin, to which they showed intermediate resistance. All enterococci were susceptible to ampicillin while 13 % showed penicillin resistance. Only one E. faecalis isolate was vancomycin-resistant. Tetracycline (51 %) and erythromycin (26 %) resistance was prevalent among the enterococci, but multidrug resistance was confined to E. faecalis (47 %) and Enterococcus faecium (33 %). Screening of enterococcal virulence traits revealed that 2 % were β-haemolytic. The structural genes of cytolysin were detected in 28 % of the isolates in five enterococcal species, the majority being E. faecalis and Enterococcus raffinosus. This study shows that bacteriocin production and antibiotic resistance is a common trait of faecal LAB of Ethiopian infants while virulence factors occur at low levels.

  4. Contribution of Enterococci to the Spread of Antibiotic Resistance in the Production Chain of Swine Meat Commodities

    National Research Council Canada - National Science Library

    Rizzotti, Lucia; Simeoni, Desj; Cocconcelli, Piersandro; Gazzola, Simona; Dellaglio, Franco; Torriani, Sandra

    2005-01-01

    ... and analyzed for the presence of 11 antibiotic resistance (AR) genes. Specific PCR assays carried out on DNA extracted directly from the samples revealed a high incidence of the genes tet(K) (80.5%), ermB (66.7%), and tet(M) (66.7...

  5. Laboratory and Field Evaluation of Dust Abatement Products for Expedient Helipads

    Science.gov (United States)

    2010-09-01

    performed by Lulu Edwards, Jeb Tingle, Quint Mason, Chase Bradley, and Jim Cole of the GSL Airfield and Pavements Branch (APB); Stacy Washington and Leroy...particles to form brittle physical bonds. They are generally polymer -based solutions with surfactants and normally have to be diluted with water...Once they are applied, the polymer particles begin to coalesce as the water evaporates from the system, leaving a soil- polymer matrix that prevents

  6. Chemical Composition, Antibacterial Activity, and Synergistic Effects with Conventional Antibiotics and Nitric Oxide Production Inhibitory Activity of Essential Oil from Geophila repens (L.) I.M. Johnst.

    Science.gov (United States)

    Rao, Huijuanzi; Lai, Pengxiang; Gao, Yang

    2017-09-17

    Geophila repens (L.) I.M. Johnst, a perennial herb, belongs to the Rubiaceae family. In this study, we identified the chemical composition of the Geophila repens essential oil (GR-EO) for the first time. Totally, seventy-seven compounds were identified according to GC and GC-MS, which represent 98.0% of the oil. And the major components of GR-EO were β-caryophyllene (23.3%), β-elemene (8.0%), farnesyl butanoate (7.4%), myrcene (3.5%), and trans-nerolidol (3.3%). Then we evaluated the antibacterial activities of GR-EO and the synergistic effects of GR-EO in combination with commercial antibiotics using the microdilution and Checkerboard method. The results demonstrated that GR-EO possessed an excellent broad spectrum antibacterial activity, especially against Pseudomonas aeruginosa and Bacillus subtilis. It also showed that the combined application of GR-EO with antibiotics led to synergistic effects in most cases. And the most prominent synergistic effect was noticed when GR-EO was in combination with Streptomycin and tested against Escherichia coli (fractional inhibitory concentration indices (FICI) of 0.13). Additionally, the results of a Griess assay revealed that GR-EO exhibited a potent inhibitory effect on NO production in lipopolysaccharide (LPS)-activated RAW 264.7 (murine macrophage) cells. In conclusion, the combination of GR-EO and the commercial antibiotics has significant potential for the development of new antimicrobial treatment and reduction of drug resistance.

  7. Comprehensive determination of macrolide antibiotics, their synthesis intermediates and transformation products in wastewater effluents and ambient waters by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Senta, Ivan; Krizman-Matasic, Ivona; Terzic, Senka; Ahel, Marijan

    2017-08-04

    Macrolide antibiotics are a prominent group of emerging contaminants frequently found in wastewater effluents and wastewater-impacted aquatic environments. In this work, a novel analytical method for simultaneous determination of parent macrolide antibiotics (azithromycin, erythromycin, clarithromycin and roxithromycin), along with their synthesis intermediates, byproducts, metabolites and transformation products in wastewater and surface water was developed and validated. Samples were enriched using solid-phase extraction on Oasis HLB cartridges and analyzed by reversed-phase liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The target macrolide compounds were separated on an ACE C18 PFP column and detected using multiple reaction monitoring in positive ionization polarity. The optimized method, which included an additional extract clean-up on strong anion-exchange cartridges (SAX), resulted in high recoveries and accuracies, low matrix effects and improved chromatographic separation of the target compounds, even in highly complex matrices, such as raw wastewater. The developed method was applied to the analysis of macrolide compounds in wastewater and river water samples from Croatia. In addition to parent antibiotics, several previously unreported macrolide transformation products and/or synthesis intermediates were detected in municipal wastewater, some of them reaching μg/L levels. Moreover, extremely high concentrations of macrolides up to mg/L level were found in pharmaceutical industry effluents, indicating possible importance of this source to the total loads into ambient waters. The results revealed a significant contribution of synthesis intermediates and transformation products to the overall mass balance of macrolides in the aquatic environment. Copyright © 2017. Published by Elsevier B.V.

  8. Genomic characterization of a new endophytic Streptomyces kebangsaanensis identifies biosynthetic pathway gene clusters for novel phenazine antibiotic production

    Directory of Open Access Journals (Sweden)

    Juwairiah Remali

    2017-11-01

    Full Text Available Background Streptomyces are well known for their capability to produce many bioactive secondary metabolites with medical and industrial importance. Here we report a novel bioactive phenazine compound, 6-((2-hydroxy-4-methoxyphenoxy carbonyl phenazine-1-carboxylic acid (HCPCA extracted from Streptomyces kebangsaanensis, an endophyte isolated from the ethnomedicinal Portulaca oleracea. Methods The HCPCA chemical structure was determined using nuclear magnetic resonance spectroscopy. We conducted whole genome sequencing for the identification of the gene cluster(s believed to be responsible for phenazine biosynthesis in order to map its corresponding pathway, in addition to bioinformatics analysis to assess the potential of S. kebangsaanensis in producing other useful secondary metabolites. Results The S. kebangsaanensis genome comprises an 8,328,719 bp linear chromosome with high GC content (71.35% consisting of 12 rRNA operons, 81 tRNA, and 7,558 protein coding genes. We identified 24 gene clusters involved in polyketide, nonribosomal peptide, terpene, bacteriocin, and siderophore biosynthesis, as well as a gene cluster predicted to be responsible for phenazine biosynthesis. Discussion The HCPCA phenazine structure was hypothesized to derive from the combination of two biosynthetic pathways, phenazine-1,6-dicarboxylic acid and 4-methoxybenzene-1,2-diol, originated from the shikimic acid pathway. The identification of a biosynthesis pathway gene cluster for phenazine antibiotics might facilitate future genetic engineering design of new synthetic phenazine antibiotics. Additionally, these findings confirm the potential of S. kebangsaanensis for producing various antibiotics and secondary metabolites.

  9. Organic Acid Salt from Complete Feed Silage Corn Based by Product as an Alternative to Substitute Antibiotic Function as a Growth Promotor for Broiler

    Directory of Open Access Journals (Sweden)

    W Negara

    2009-11-01

    Full Text Available This study was designed to evaluate the efficacy of organic acid salt Zn from complete feed silage based on corn by product as an alternative to subtitute antibiotic function as a growth promotor for broiler. Ninety day old commercial Cobb broiler chickens were randomly distributed into six groups having three replicates of five birds in each group. Negative control (R0 birds were offered standard basal diet and no challenged, positive control (R1 birds were offered standard basal diet and challenged with 107 Salmonella typhimurium. Treatment R2, R3, R4 and R5 were challenged by 107 CFU of Salmonella typhimurium which added in feed with 0.1% flouroquinolone, 0.1%, 0.2%, and 0.3% of organic acid salts. The result showed that dietary of organic acid salts affect consumption, weight gain, and final body weight (P<0.05. Meanwhile, feed conversion (FCR was not affected by antibiotics nor organic acids. Our conclusion, Dietary organic acid salt from complete feed silage corn based by product until dose 0.2% can improve the performance of broiler chickens infected Salmonella typhimurium. (Animal Production 11(3: 170-175 (2009 Key Words: broiler, organic acid, Salmonella typhimurium

  10. Nucleoside antibiotics: biosynthesis, regulation, and biotechnology.

    Science.gov (United States)

    Niu, Guoqing; Tan, Huarong

    2015-02-01

    The alarming rise in antibiotic-resistant pathogens has coincided with a decline in the supply of new antibiotics. It is therefore of great importance to find and create new antibiotics. Nucleoside antibiotics are a large family of natural products with diverse biological functions. Their biosynthesis is a complex process through multistep enzymatic reactions and is subject to hierarchical regulation. Genetic and biochemical studies of the biosynthetic machinery have provided the basis for pathway engineering and combinatorial biosynthesis to create new or hybrid nucleoside antibiotics. Dissection of regulatory mechanisms is leading to strategies to increase the titer of bioactive nucleoside antibiotics. Copyright © 2014. Published by Elsevier Ltd.

  11. Antibiotic Resistance

    DEFF Research Database (Denmark)

    Hansen, Malene Plejdrup; Hoffmann, Tammy C; McCullough, Amanda R

    2015-01-01

    Numerous opportunities are available in primary care for alleviating the crisis of increasing antibiotic resistance. Preventing patients from developing an acute respiratory infection (ARI) will obviate any need for antibiotic use downstream. Hygiene measures such as physical barriers and hand...... hygiene, and possibly vaccination and exercise, may be effective. Also, a large range of complementary and alternative medicines (e.g. zinc, vitamin C and probiotics) are proposed for preventing and treating ARIs, but evidence for efficacy is scarce. General practitioners' (GPs) attitudes towards...

  12. Antibiotics for acute bronchitis.

    Science.gov (United States)

    Smith, Susan M; Fahey, Tom; Smucny, John; Becker, Lorne A

    2017-06-19

    The benefits and risks of antibiotics for acute bronchitis remain unclear despite it being one of the most common illnesses seen in primary care. To assess the effects of antibiotics in improving outcomes and to assess adverse effects of antibiotic therapy for people with a clinical diagnosis of acute bronchitis. We searched CENTRAL 2016, Issue 11 (accessed 13 January 2017), MEDLINE (1966 to January week 1, 2017), Embase (1974 to 13 January 2017), and LILACS (1982 to 13 January 2017). We searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov on 5 April 2017. Randomised controlled trials comparing any antibiotic therapy with placebo or no treatment in acute bronchitis or acute productive cough, in people without underlying pulmonary disease. At least two review authors extracted data and assessed trial quality. We did not identify any new trials for inclusion in this 2017 update. We included 17 trials with 5099 participants in the primary analysis. The quality of trials was generally good. At follow-up there was no difference in participants described as being clinically improved between the antibiotic and placebo groups (11 studies with 3841 participants, risk ratio (RR) 1.07, 95% confidence interval (CI) 0.99 to 1.15). Participants given antibiotics were less likely to have a cough (4 studies with 275 participants, RR 0.64, 95% CI 0.49 to 0.85; number needed to treat for an additional beneficial outcome (NNTB) 6) and a night cough (4 studies with 538 participants, RR 0.67, 95% CI 0.54 to 0.83; NNTB 7). Participants given antibiotics had a shorter mean cough duration (7 studies with 2776 participants, mean difference (MD) -0.46 days, 95% CI -0.87 to -0.04). The differences in presence of a productive cough at follow-up and MD of productive cough did not reach statistical significance.Antibiotic-treated participants were more likely to be improved according to clinician's global assessment (6 studies

  13. Expedient total synthesis of small to medium-sized membrane proteins via Fmoc chemistry.

    Science.gov (United States)

    Zheng, Ji-Shen; Yu, Mu; Qi, Yun-Kun; Tang, Shan; Shen, Fei; Wang, Zhi-Peng; Xiao, Liang; Zhang, Longhua; Tian, Chang-Lin; Liu, Lei

    2014-03-05

    Total chemical synthesis provides a unique approach for the access to uncontaminated, monodisperse, and more importantly, post-translationally modified membrane proteins. In the present study we report a practical procedure for expedient and cost-effective synthesis of small to medium-sized membrane proteins in multimilligram scale through the use of automated Fmoc chemistry. The key finding of our study is that after the attachment of a removable arginine-tagged backbone modification group, the membrane protein segments behave almost the same as ordinary water-soluble peptides in terms of Fmoc solid-phase synthesis, ligation, purification, and mass spectrometry characterization. The efficiency and practicality of the new method is demonstrated by the successful preparation of Ser64-phosphorylated M2 proton channel from influenza A virus and the membrane-embedded domain of an inward rectifier K(+) channel protein Kir5.1. Functional characterizations of these chemically synthesized membrane proteins indicate that they provide useful and otherwise-difficult-to-access materials for biochemistry and biophysics studies.

  14. Expedient synthesis of C-aryl carbohydrates by consecutive biocatalytic benzoin and aldol reactions.

    Science.gov (United States)

    Hernández, Karel; Parella, Teodor; Joglar, Jesús; Bujons, Jordi; Pohl, Martina; Clapés, Pere

    2015-02-16

    The introduction of aromatic residues connected by a C-C bond into the non-reducing end of carbohydrates is highly significant for the development of innovative structures with improved binding affinity and selectivity (e.g., C-aril-sLex). In this work, an expedient asymmetric "de novo" synthetic route to new aryl carbohydrate derivatives based on two sequential stereoselectively biocatalytic carboligation reactions is presented. First, the benzoin reaction of aromatic aldehydes to dimethoxyacetaldehyde is conducted, catalyzed by benzaldehyde lyase from Pseudomonas fluorescens biovar I. Then, the α-hydroxyketones formed are reduced by using NaBH4 yielding the anti diol. After acetal hydrolysis, the aldol addition of dihydroxyacetone, hydroxyacetone, or glycolaldehyde catalyzed by the stereocomplementary D-fructose-6-phosphate aldolase and L-rhamnulose-1-phosphate aldolase is performed. Both aldolases accept unphosphorylated donor substrates, avoiding the need of handling the phosphate group that the dihydroxyacetone phosphate-dependent aldolases require. In this way, 6-C-aryl-L-sorbose, 6-C-aryl-L-fructose, 6-C-aryl-L-tagatose, and 5-C-aryl-L-xylose derivatives are prepared by using this methodology. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Justification of the Expediency of Creating Circular Intersections in Modern Cities

    Science.gov (United States)

    Vasilyeva, Elena; Sazonova, Tatiana

    2017-10-01

    The article resumes the principles of driving on Circular Intersections, which causes difficulties for some road users. Referring to certain foreign Traffic regulations, the author points out that such intersections are still stated imprecisely in Traffic regulations. Advantages and disadvantages of circular intersections as well as the expediency of their creation in the cities are considered in the article. The author offers to distinguish several types of circular intersections and claims that the most part of disadvantages listed in the article belong to circular intersections of the old type. On the contrary, the author presumes that creation of modern circular intersections will allow to regulate the planning of cities, make heavy traffic of transport possible while increasing the traffic safety at the same time, to improve the ecological situation of the city as well as its appearance, to carry out energy saving in the transport infrastructure of the city. All these aims could be feasible due to the creation of modern intersections of the Roundabout type.

  16. Antibiotic resistance in wild birds

    National Research Council Canada - National Science Library

    Bonnedahl, Jonas; Järhult, Josef D

    2014-01-01

    .... Antibiotic-resistant bacteria have been isolated from a multitude of wild bird species. Several studies strongly indicate transmission of resistant bacteria from human rest products to wild birds...

  17. Gene Sequence Based Clustering Assists in Dereplication of Pseudoalteromonas luteoviolacea Strains with Identical Inhibitory Activity and Antibiotic Production

    Directory of Open Access Journals (Sweden)

    Lone Gram

    2012-08-01

    Full Text Available Some microbial species are chemically homogenous, and the same secondary metabolites are found in all strains. In contrast, we previously found that five strains of P. luteoviolacea were closely related by 16S rRNA gene sequence but produced two different antibiotic profiles. The purpose of the present study was to determine whether such bioactivity differences could be linked to genotypes allowing methods from phylogenetic analysis to aid in selection of strains for biodiscovery. Thirteen P. luteoviolacea strains divided into three chemotypes based on production of known antibiotics and four antibacterial profiles based on inhibition assays against Vibrio anguillarum and Staphylococcus aureus. To determine whether chemotype and inhibition profile are reflected by phylogenetic clustering we sequenced 16S rRNA, gyrB and recA genes. Clustering based on 16S rRNA gene sequences alone showed little correlation to chemotypes and inhibition profiles, while clustering based on concatenated 16S rRNA, gyrB, and recA gene sequences resulted in three clusters, two of which uniformly consisted of strains of identical chemotype and inhibition profile. A major time sink in natural products discovery is the effort spent rediscovering known compounds, and this study indicates that phylogeny clustering of bioactive species has the potential to be a useful dereplication tool in biodiscovery efforts.

  18. The Logic, Experimental Steps, and Potential of Heterologous Natural Product Biosynthesis Featuring the Complex Antibiotic Erythromycin A Produced Through E. coli

    Science.gov (United States)

    Jiang, Ming; Zhang, Haoran; Pfeifer, Blaine A.

    2013-01-01

    The heterologous production of complex natural products is an approach designed to address current limitations and future possibilities. It is particularly useful for those compounds which possess therapeutic value but cannot be sufficiently produced or would benefit from an improved form of production. The experimental procedures involved can be subdivided into three components: 1) genetic transfer; 2) heterologous reconstitution; and 3) product analysis. Each experimental component is under continual optimization to meet the challenges and anticipate the opportunities associated with this emerging approach. Heterologous biosynthesis begins with the identification of a genetic sequence responsible for a valuable natural product. Transferring this sequence to a heterologous host is complicated by the biosynthetic pathway complexity responsible for product formation. The antibiotic erythromycin A is a good example. Twenty genes (totaling >50 kb) are required for eventual biosynthesis. In addition, three of these genes encode megasynthases, multi-domain enzymes each ~300 kDa in size. This genetic material must be designed and transferred to E. coli for reconstituted biosynthesis. The use of PCR isolation, operon construction, multi-cystronic plasmids, and electro-transformation will be described in transferring the erythromycin A genetic cluster to E. coli. Once transferred, the E. coli cell must support eventual biosynthesis. This process is also challenging given the substantial differences between E. coli and most original hosts responsible for complex natural product formation. The cell must provide necessary substrates to support biosynthesis and coordinately express the transferred genetic cluster to produce active enzymes. In the case of erythromycin A, the E. coli cell had to be engineered to provide the two precursors (propionyl-CoA and (2S)-methylmalonyl-CoA) required for biosynthesis. In addition, gene sequence modifications, plasmid copy number

  19. The logic, experimental steps, and potential of heterologous natural product biosynthesis featuring the complex antibiotic erythromycin A produced through E. coli.

    Science.gov (United States)

    Jiang, Ming; Zhang, Haoran; Pfeifer, Blaine A

    2013-01-13

    The heterologous production of complex natural products is an approach designed to address current limitations and future possibilities. It is particularly useful for those compounds which possess therapeutic value but cannot be sufficiently produced or would benefit from an improved form of production. The experimental procedures involved can be subdivided into three components: 1) genetic transfer; 2) heterologous reconstitution; and 3) product analysis. Each experimental component is under continual optimization to meet the challenges and anticipate the opportunities associated with this emerging approach. Heterologous biosynthesis begins with the identification of a genetic sequence responsible for a valuable natural product. Transferring this sequence to a heterologous host is complicated by the biosynthetic pathway complexity responsible for product formation. The antibiotic erythromycin A is a good example. Twenty genes (totaling >50 kb) are required for eventual biosynthesis. In addition, three of these genes encode megasynthases, multi-domain enzymes each ~300 kDa in size. This genetic material must be designed and transferred to E. coli for reconstituted biosynthesis. The use of PCR isolation, operon construction, multi-cystronic plasmids, and electro-transformation will be described in transferring the erythromycin A genetic cluster to E. coli. Once transferred, the E. coli cell must support eventual biosynthesis. This process is also challenging given the substantial differences between E. coli and most original hosts responsible for complex natural product formation. The cell must provide necessary substrates to support biosynthesis and coordinately express the transferred genetic cluster to produce active enzymes. In the case of erythromycin A, the E. coli cell had to be engineered to provide the two precursors (propionyl-CoA and (2S)-methylmalonyl-CoA) required for biosynthesis. In addition, gene sequence modifications, plasmid copy number

  20. Rapid synthesis of long chain fatty acid esters of steroids in ionic liquids with microwave irradiation: expedient one-pot procedure for estradiol monoesters.

    Science.gov (United States)

    Deb, Somdatta; Wähälä, Kristiina

    2010-10-01

    We report the rapid synthesis (1min) in high yield of fatty acid ester (FAE) derivatives of several steroids under microwave irradiation in an ionic liquid (IL). An expedient regioselective hydrolysis at C-3 of estradiol diesters is also reported.

  1. Study on isolation, molecular detection of virulence gene and antibiotic sensitivity pattern of Escherichia coli isolated from milk and milk products

    Directory of Open Access Journals (Sweden)

    M. N. Brahmbhatt

    2013-06-01

    Full Text Available Aim: The study was undertaken to isolate pathogenic E. coli from milk and various milk products, detection of virulence gene using Polymerase chain reaction (PCR and investigate their antibiotic sensitivity pattern. Materials and Methods: Altogether 250 milk and various milk products samples consisting of raw milk (50, cheese (50, ice-cream (50, mawa (50 and dahi (50 were collected from milk vendors, retail shops located in Anand city, under aseptic precautions. For the enrichment of the organism from the collected samples, MacConkey broth was used and inoculation was carried out on MacConkey agar and EMB agar. Later on, to confirm the isolates, various biochemical tests such as IMViC test, Urease test were performed. Evaluation of antibiotic sensitivity pattern of E. coli was assessed by disk diffusion method. Finally the E. coli isolates were screened for the presence of virulence associated genes by PCR . Results: The prevalence of E. coli was observed 32 % in the samples comprising of milk (52.00%, cheese (28.00%, icecream (20.00%, mawa (44.00%, and dahi (16.00%. Antibiotic sensitivity was recorded high for Co-trimoxazole (100% followed by Gentamicin (96.73%, Trimithoprime (93.47% and Doxycycline hydochloride (92.39%. Least sensitivity was recorded for Ampicillin (8.69%. In this study, out of 80 E. coli isolates, 25 isolates (31.25% were positive for stx genes, of which 7 (8.75% isolates were positive for stx1 gene only, while 12 (15.00% isolates were positive for stx2 gene only and 5 (6.25% isolates were positive for both stx1 and stx2, 7 isolates (8.75% were positive for eaeA gene and all the isolate were negetive for rfb O157 gene. Conclusions: Current study supports the finding that raw milk and various milk products can be regarded as critical source of pathogenic E. coli This explains the need of strict monitoring and surveillance for effective measures of hygiene and sanitary practice during production of milk and various milk

  2. Chemical Composition, Antibacterial Activity, and Synergistic Effects with Conventional Antibiotics and Nitric Oxide Production Inhibitory Activity of Essential Oil from Geophila repens (L. I.M. Johnst

    Directory of Open Access Journals (Sweden)

    Huijuanzi Rao

    2017-09-01

    Full Text Available Geophila repens (L. I.M. Johnst, a perennial herb, belongs to the Rubiaceae family. In this study, we identified the chemical composition of the Geophila repens essential oil (GR-EO for the first time. Totally, seventy-seven compounds were identified according to GC and GC-MS, which represent 98.0% of the oil. And the major components of GR-EO were β-caryophyllene (23.3%, β-elemene (8.0%, farnesyl butanoate (7.4%, myrcene (3.5%, and trans-nerolidol (3.3%. Then we evaluated the antibacterial activities of GR-EO and the synergistic effects of GR-EO in combination with commercial antibiotics using the microdilution and Checkerboard method. The results demonstrated that GR-EO possessed an excellent broad spectrum antibacterial activity, especially against Pseudomonas aeruginosa and Bacillus subtilis. It also showed that the combined application of GR-EO with antibiotics led to synergistic effects in most cases. And the most prominent synergistic effect was noticed when GR-EO was in combination with Streptomycin and tested against Escherichia coli (fractional inhibitory concentration indices (FICI of 0.13. Additionally, the results of a Griess assay revealed that GR-EO exhibited a potent inhibitory effect on NO production in lipopolysaccharide (LPS-activated RAW 264.7 (murine macrophage cells. In conclusion, the combination of GR-EO and the commercial antibiotics has significant potential for the development of new antimicrobial treatment and reduction of drug resistance.

  3. Antibiotic Resistance

    DEFF Research Database (Denmark)

    Munck, Christian

    of antimicrobial resistance: (1) adaptive mutations and (2) horizontal acquisition of resistance genes from antibiotic gene reservoirs. By studying the geno- and phenotypic changes of E. coli in response to single and drug-pair exposures, I uncover the evolutionary trajectories leading to adaptive resistance. I......Bacteria can avoid extinction during antimicrobial exposure by becoming resistant. They achieve this either via adaptive mutations or horizontally acquired resistance genes. If resistance emerges in clinical relevant species, it can lead to treatment failure and ultimately result in increasing...... morbidity and mortality as well as an increase in the cost of treatment. Understanding how bacteria respond to antibiotic exposure gives the foundations for a rational approach to counteract antimicrobial resistance. In the work presented in this thesis, I explore the two fundamental sources...

  4. Antibiotic resistance, virulence determinants and production of biogenic amines among enterococci from ovine, feline, canine, porcine and human milk.

    Science.gov (United States)

    Jiménez, Esther; Ladero, Victor; Chico, Irene; Maldonado-Barragán, Antonio; López, María; Martín, Virginia; Fernández, Leonides; Fernández, María; Álvarez, Miguel A; Torres, Carmen; Rodríguez, Juan M

    2013-12-10

    Recent studies have shown that mammalian milk represents a continuous supply of commensal bacteria, including enterococci. The objectives of this study were to evaluate the presence of enterococci in milk of different species and to screen them for several genetic and phenotypic traits of clinical significance among enterococci. Samples were obtained from, at least, nine porcine, canine, ovine, feline and human healthy hosts. Enterococci could be isolated, at a concentration of 1.00 × 10(2) -1.16 × 10(3) CFU/ml, from all the porcine samples and, also from 85, 50, 25 and 25% of the human, canine, feline and ovine ones, respectively. They were identified as Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Enterococcus casseliflavus and Enterococcus durans. Among the 120 initial enterococcal isolates, 36 were selected on the basis of their different PFGE profiles and further characterized. MLST analysis revealed a wide diversity of STs among the E. faecalis and E. faecium strains, including some frequently associated to hospital infections and novel STs. All the E. faecalis strains possessed some of the potential virulence determinants (cad, ccf, cob, cpd, efaA(fs), agg2, gelE, cylA, esp(fs)) assayed while the E. faecium ones only harboured the efaA(fm) gene. All the tested strains were susceptible to tigecycline, linezolid and vancomycin, and produced tyramine. Their susceptibility to the rest of the antimicrobials and their ability to produce other biogenic amines varied depending on the strain. Enterococci strains isolated from porcine samples showed the widest spectrum of antibiotic resistance. Enterococci isolated from milk of different mammals showed a great genetic diversity. The wide distribution of virulence genes and/or antibiotic resistance among the E. faecalis and E. faecium isolates indicates that they can constitute a reservoir of such traits and a risk to animal and human health.

  5. Extracts of Canadian first nations medicinal plants, used as natural products, inhibit neisseria gonorrhoeae isolates with different antibiotic resistance profiles.

    Science.gov (United States)

    Cybulska, Paulina; Thakur, Sidharath D; Foster, Brian C; Scott, Ian M; Leduc, Renée I; Arnason, John T; Dillon, Jo-Anne R

    2011-07-01

    Neisseria gonorrhoeae (Ng) has developed resistance to most antimicrobial agents and the antibiotics recommended for therapy are restricted, for the most part, to third generation cephalosporins. In order to investigate new potential sources of antimicrobial agents, the antibacterial properties of 14 Canadian plants used in traditional First Nations' medicine were tested against Ng isolates having differing antimicrobial susceptibility profiles. Ethanolic extracts of 14 Canadian botanicals, analyzed by high-performance liquid chromatography, were tested for their antimicrobial activity (disc diffusion and/or agar dilution assays) against susceptible Ng reference strains and a panel of 28 Ng isolates with various antimicrobial resistance profiles. Extracts of Arctostaphylos uva ursi (kinnikinnick or bearberry), Hydrastis canadensis (goldenseal), Prunus serotina (black cherry), and Rhodiola rosea (roseroot) inhibited the growth of all Ng isolates with minimum inhibitory concentrations of 32 μg/mL, 4 to 32 μg/mL, 16 to >32 μg/mL, and 32 to 64 μg/mL, respectively. Extracts of Acorus americanus (sweet flag), Berberis vulgaris (barberry), Cimicifuga racemosa (black cohosh), Equisetum arvense (field horsetail), Gaultheria procumbens (wintergreen), Ledum groenlandicum (Labrador tea), Ledum palustre (marsh Labrador tea), Oenothera biennis (common evening primrose), Sambucus nigra (elderberry), and Zanthoxylum americanum (prickly ash) had weak or no antimicrobial activity against the Ng isolates with minimum inhibitory concentrations ≥256 μg/mL. The phytochemical berberine from H. canadensis inhibited the growth of all Ng isolates. The phytochemicals, salidroside and rosavin, present in R. rosea, also showed inhibitory activity against Ng strains. Canadian botanicals represent a potential source of novel compounds which inhibit Ng, including isolates resistant to antibiotics.

  6. Unraveling the physiological complexities of antibiotic lethality.

    Science.gov (United States)

    Dwyer, Daniel J; Collins, James J; Walker, Graham C

    2015-01-01

    We face an impending crisis in our ability to treat infectious disease brought about by the emergence of antibiotic-resistant pathogens and a decline in the development of new antibiotics. Urgent action is needed. This review focuses on a less well-understood aspect of antibiotic action: the complex metabolic events that occur subsequent to the interaction of antibiotics with their molecular targets and play roles in antibiotic lethality. Independent lines of evidence from studies of the action of bactericidal antibiotics on diverse bacteria collectively suggest that the initial interactions of drugs with their targets cannot fully account for the antibiotic lethality and that these interactions elicit the production of reactive oxidants including reactive oxygen species that contribute to bacterial cell death. Recent challenges to this concept are considered in the context of the broader literature of this emerging area of research. Possible ways that this new knowledge might be exploited to improve antibiotic therapy are also considered.

  7. Evolving medicinal chemistry strategies in antibiotic discovery.

    Science.gov (United States)

    Pawlowski, Andrew C; Johnson, Jarrod W; Wright, Gerard D

    2016-12-01

    Chemical modification of synthetic or natural product antibiotic scaffolds to expand potency and spectrum and to bypass mechanisms of resistance has dominated antibiotic drug discovery and proven immensely successful. However, the inexorable evolution of drug resistance coupled with a drought in innovation in antibiotic discovery contribute to a dearth of new drugs entering to market. Better understanding of the physicochemical properties of antibiotic chemical space is required to inform new antibiotic discovery. Innovations such as the development of antibiotic adjuvants to preserve efficacy of existing drugs together with expanding antibiotic chemical diversity through synthetic biology or new techniques to mine antibiotic producing organisms, are required to bridge the growing gap between the need for new drugs and their discovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Collective antibiotic tolerance: mechanisms, dynamics and intervention.

    Science.gov (United States)

    Meredith, Hannah R; Srimani, Jaydeep K; Lee, Anna J; Lopatkin, Allison J; You, Lingchong

    2015-03-01

    Bacteria have developed resistance against every antibiotic at a rate that is alarming considering the timescale at which new antibiotics are developed. Thus, there is a critical need to use antibiotics more effectively, extend the shelf life of existing antibiotics and minimize their side effects. This requires understanding the mechanisms underlying bacterial drug responses. Past studies have focused on survival in the presence of antibiotics by individual cells, as genetic mutants or persisters. Also important, however, is the fact that a population of bacterial cells can collectively survive antibiotic treatments lethal to individual cells. This tolerance can arise by diverse mechanisms, including resistance-conferring enzyme production, titration-mediated bistable growth inhibition, swarming and interpopulation interactions. These strategies can enable rapid population recovery after antibiotic treatment and provide a time window during which otherwise susceptible bacteria can acquire inheritable genetic resistance. Here, we emphasize the potential for targeting collective antibiotic tolerance behaviors as an antibacterial treatment strategy.

  9. Establishing motives for committing crimes: criminalistic possibilities and criminal procedure expediency

    Directory of Open Access Journals (Sweden)

    Kornakova S.V.

    2014-12-01

    Full Text Available The lack of unanimity on the motive understanding by psychologists studying the motivation of goal-oriented behavior and lawyers analyzing the crime causes and mechanisms is stated. The possibility of unconscious motives of criminal behavior is admitted. The practical problems of es-tablishing and proving the motives for specific crimes, which can be judged only presumably, by studying actus reus and perpetrator’s testimony, are shown. Establishing the motive for crime is complicated by the fact that the guilty person is often not aware of it, conceals or distorts it. The authors acknowledge that crime is impossible without a motive (talking about mentally healthy person. Consequently, they state the inevitable difficulties in establishing any motive and the lack of objective need for its establishing to find a person guilty of committing a crime. The expediency of establishing cognition limits of crime psychology by the subject of proof is argued. It’s concluded that the preliminary investigation bodies and courts must fully, comprehensively and objectively investigate the circumstances that determine the conclusion about the presence or absence of guilty motive in perpetrator’s actions. They must justify this conclusion in the indictment and sentence by bringing evidence only in case if this motive is provided by criminal law as element of crime. It’s argued that the list of circumstances to be proved in every criminal case, provided by article 73 of the RF Criminal Procedure Code, can’t be considered satisfactory, if practical possibilities of their establishing aren’t taken into account. It’s proposed to exclude the motives for crime from this list.

  10. Antibiotic multiresistance analysis of mesophilic and psychrotrophic Pseudomonas spp. isolated from goat and lamb slaughterhouse surfaces throughout the meat production process.

    Science.gov (United States)

    Lavilla Lerma, Leyre; Benomar, Nabil; Casado Muñoz, María del Carmen; Gálvez, Antonio; Abriouel, Hikmate

    2014-11-01

    The aim of this study was to investigate the phenotypic and genotypic antibiotic resistance profiles of pseudomonads isolated from surfaces of a goat and lamb slaughterhouse, which were representative of areas that are possible sources of meat contamination. Mesophilic (85 isolates) and psychrotrophic (37 isolates) pseudomonads identified at the species level generally were resistant to sulfamethoxazole, erythromycin, amoxicillin, ampicillin, chloramphenicol, trimethoprim, rifampin, and ceftazidime (especially mesophiles), as well as colistin and tetracycline (especially psychrotrophes). However, they generally were sensitive to ciprofloxacin, gentamicin, imipenem, and kanamycin regardless of species identity. Worryingly, in the present study, we found multidrug resistance (MDR) to up to 13 antibiotics, which was related to intrinsic and acquired resistance mechanisms. Furthermore, a link between various antimicrobial resistance genes was shown for beta-lactams and tetracycline, trimethoprim, and sulfonamides. The distribution and resistome-based analysis of MDR pseudomonads in different slaughterhouse zones indicated that the main sources of the identical or related pseudomonad strains were the animals (feet and wool) and the slaughterhouse environment, being disseminated from the beginning, or entrance environment, to the environment of the finished meat products. Those facts must be taken into consideration to avoid cross-contamination with the subsequent flow of mobile resistance determinants throughout all slaughterhouse zones and then to humans and the environment by the application of adequate practices of hygiene and disinfection measures, including those for animal wool and feet and also the entrance environment. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  11. Scale-up bioprocess development for production of the antibiotic valinomycin in Escherichia coli based on consistent fed-batch cultivations.

    Science.gov (United States)

    Li, Jian; Jaitzig, Jennifer; Lu, Ping; Süssmuth, Roderich D; Neubauer, Peter

    2015-06-12

    Heterologous production of natural products in Escherichia coli has emerged as an attractive strategy to obtain molecules of interest. Although technically feasible most of them are still constrained to laboratory scale production. Therefore, it is necessary to develop reasonable scale-up strategies for bioprocesses aiming at the overproduction of targeted natural products under industrial scale conditions. To this end, we used the production of the antibiotic valinomycin in E. coli as a model system for scalable bioprocess development based on consistent fed-batch cultivations. In this work, the glucose limited fed-batch strategy based on pure mineral salt medium was used throughout all scales for valinomycin production. The optimal glucose feed rate was initially detected by the use of a biocatalytically controlled glucose release (EnBase® technology) in parallel cultivations in 24-well plates with continuous monitoring of pH and dissolved oxygen. These results were confirmed in shake flasks, where the accumulation of valinomycin was highest when the specific growth rate decreased below 0.1 h(-1). This correlation was also observed for high cell density fed-batch cultivations in a lab-scale bioreactor. The bioreactor fermentation produced valinomycin with titers of more than 2 mg L(-1) based on the feeding of a concentrated glucose solution. Valinomycin production was not affected by oscillating conditions (i.e. glucose and oxygen) in a scale-down two-compartment reactor, which could mimic similar situations in industrial bioreactors, suggesting that the process is very robust and a scaling of the process to a larger industrial scale appears a realistic scenario. Valinomycin production was scaled up from mL volumes to 10 L with consistent use of the fed-batch technology. This work presents a robust and reliable approach for scalable bioprocess development and represents an example for the consistent development of a process for a heterologously expressed natural

  12. Broad-Host-Range Expression Reveals Native and Host Regulatory Elements That Influence Heterologous Antibiotic Production in Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Jia Jia Zhang

    2017-09-01

    Full Text Available Heterologous expression has become a powerful tool for studying microbial biosynthetic gene clusters (BGCs. Here, we extend the transformation-associated recombination cloning and heterologous expression platform for microbial BGCs to include Gram-negative proteobacterial expression hosts. Using a broad-host-range expression platform, we test the implicit assumption that biosynthetic pathways are more successfully expressed in more closely related heterologous hosts. Cloning and expression of the violacein BGC from Pseudoalteromonas luteoviolacea 2ta16 revealed robust production in two proteobacterial hosts, Pseudomonas putida KT2440 and Agrobacterium tumefaciens LBA4404, but very little production of the antibiotic in various laboratory strains of Escherichia coli, despite their closer phylogenetic relationship. We identified a nonclustered LuxR-type quorum-sensing receptor from P. luteoviolacea 2ta16, PviR, that increases pathway transcription and violacein production in E. coli by ∼60-fold independently of acyl-homoserine lactone autoinducers. Although E. coli harbors the most similar homolog of PviR identified from all of the hosts tested, overexpression of various E. coli transcription factors did not result in a statistically significant increase in violacein production, while overexpression of two A. tumefaciens PviR homologs significantly increased production. Thus, this work not only introduces a new genetic platform for the heterologous expression of microbial BGCs, it also challenges the assumption that host phylogeny is an accurate predictor of host compatibility.

  13. Resistance to Antibiotics Mediated by Target Alterations

    Science.gov (United States)

    Spratt, Brian G.

    1994-04-01

    The development of resistance to antibiotics by reductions in the affinities of their enzymatic targets occurs most rapidly for antibiotics that inactivate a single target and that are not analogs of substrate. In these cases of resistance (for example, resistance to rifampicin), numerous single amino acid substitutions may provide large decreases in the affinity of the target for the antibiotic, leading to clinically significant levels of resistance. Resistance due to target alterations should occur much more slowly for those antibiotics (penicillin, for example) that inactivate multiple targets irreversibly by acting as close analogs of substrate. Resistance to penicillin because of target changes has emerged, by unexpected mechanisms, only in a limited number of species. However, inactivating enzymes commonly provide resistance to antibiotics that, like penicillin, are derived from natural products, although such enzymes have not been found for synthetic antibiotics. Thus, the ideal antibiotic would be produced by rational design, rather than by the modification of a natural product.

  14. Beyond Antibiotics?

    Directory of Open Access Journals (Sweden)

    LE Nicolle

    2006-01-01

    Full Text Available The AMMI Canada meeting in March 2006 hosted a symposium exploring the potential alternatives to antibiotics for the prevention and treatment of infection. Four papers summarizing talks from that session are published in this issue of the Journal (1-4. These reviews address the scientific underpinnings for a number of proposed concepts, and summarize the current status of clinical use. The approaches - probiotics, bacteriophage therapy, and manipulation of innate immunity - are all intriguing but are still removed from immediate practical applications.

  15. The LacI–Family Transcription Factor, RbsR, Is a Pleiotropic Regulator of Motility, Virulence, Siderophore and Antibiotic Production, Gas Vesicle Morphogenesis and Flotation in Serratia

    Directory of Open Access Journals (Sweden)

    Chin M. Lee

    2017-09-01

    Full Text Available Gas vesicles (GVs are proteinaceous, gas-filled organelles used by some bacteria to enable upward movement into favorable air/liquid interfaces in aquatic environments. Serratia sp. ATCC39006 (S39006 was the first enterobacterium discovered to produce GVs naturally. The regulation of GV assembly in this host is complex and part of a wider regulatory network affecting various phenotypes, including antibiotic biosynthesis. To identify new regulators of GVs, a comprehensive mutant library containing 71,000 insertion mutants was generated by random transposon mutagenesis and 311 putative GV-defective mutants identified. Three of these mutants were found to have a transposon inserted in a LacI family transcription regulator gene (rbsR of the putative ribose operon. Each of these rbsR mutants was GV-defective; no GVs were visible by phase contrast microscopy (PCM or transmission electron microscopy (TEM. GV deficiency was caused by the reduction of gvpA1 and gvrA transcription (the first genes of the two contiguous operons in the GV gene locus. Our results also showed that a mutation in rbsR was highly pleiotropic; the production of two secondary metabolites (carbapenem and prodigiosin antibiotics was abolished. Interestingly, the intrinsic resistance to the carbapenem antibiotic was not affected by the rbsR mutation. In addition, the production of a siderophore, cellulase and plant virulence was reduced in the mutant, whereas it exhibited increased swimming and swarming motility. The RbsR protein was predicted to bind to regions upstream of at least 18 genes in S39006 including rbsD (the first gene of the ribose operon and gvrA. Electrophoretic mobility shift assays (EMSA confirmed that RbsR bound to DNA sequences upstream of rbsD, but not gvrA. The results of this study indicate that RbsR is a global regulator that affects the modulation of GV biogenesis, but also with complex pleiotropic physiological impacts in S39006.

  16. 21 CFR 333.110 - First aid antibiotic active ingredients.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false First aid antibiotic active ingredients. 333.110... (CONTINUED) DRUGS FOR HUMAN USE TOPICAL ANTIMICROBIAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE First Aid Antibiotic Drug Products § 333.110 First aid antibiotic active ingredients. The product consists of any of...

  17. As expedições da Liverpool School of Tropical Medicine e a Amazônia Brasileira

    OpenAIRE

    MIRANDA, Aristóteles Guilliod de; ABREU JUNIOR, José Maria de Castro

    2011-01-01

    O artigo relata os primeiros anos de funcionamento da Escola de Medicina Tropical de Liverpool e as expedições enviadas para a Amazônia brasileira, para as Cidades de Belém e Manaus, descrevendo o que aconteceu com os pesquisadores envolvidos, Herbert Durhan, Walter Myers e Harold Wolferstan Thomas. ABSTRACT: This paper describe the early years of the Liverpool School of Tropical Medicine, and the expeditions to Brasilian Amazon, to the Cities of Belém and Manaus describing also what happe...

  18. Staphylococcus aureus from milk and milk products in Ethiopia : prevalence, enterotoxigenic potential, antibiotic resistance and spa types

    OpenAIRE

    Tarekgne, Enquebaher Kassaye

    2017-01-01

    Milk production in Ethiopia is increasing. However, due to unhygienic and traditional milk production and processing practices the issue of milk safety remains a challenge. If these safety issues are not properly addressed, the high nutritional composition and neutral pH of milk may convey many milk-borne pathogens, including Staphylococcus aureus, which imposes health risks to the consumer. S. aureus is an important food-borne pathogen globally as it can cause staphylococcal food poisoning (...

  19. The Double Life of Antibiotics

    Science.gov (United States)

    Yap, Mee-Ngan F.

    2013-01-01

    Antibiotic resistance is a persistent health care problem worldwide. Evidence for the negative consequences of subtherapeutic feeding in livestock production has been mounting while the antibiotic pipeline is drying up. In recent years, there has been a paradigm shift in our perception of antibiotics. Apart from its roles in self-defense, antibiotics also serve as inter-microbial signaling molecules, regulators of gene expression, microbial food sources, and as mediators of host immune response. “The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily under-dose himself and by exposing his microbes to nonlethal quantities of the drug make them resistant.”~Alexander Fleming PMID:24003650

  20. Combating Antibiotic Resistance

    Science.gov (United States)

    ... that could be performed to evaluate how an antibacterial drug works for the treatment of different types of infections. Updated: ... More Information Antibiotics and Antibiotic Resistance Antimicrobial ...

  1. Immune modulation of innate immunity as alternatives-to-antibiotics strategies to mitigate the use of drugs in poultry production

    National Research Council Canada - National Science Library

    Lillehoj, H. S; Lee, K. W

    2012-01-01

    ... of…” delivered July 16, 2011, at the Poultry Science Association’s 100th annual meeting, St. Louis, Missouri. The symposium examined various aspects that will impact the future of poultry production over the next 10 to 20 yr...

  2. Antibiotic production improvement in the rare actinomycete Planobispora rosea by selection of mutants resistant to the aminoglycosides streptomycin and gentamycin and to rifamycin.

    Science.gov (United States)

    Beltrametti, Fabrizio; Rossi, Roberta; Selva, Enrico; Marinelli, Flavia

    2006-04-01

    During a strain improvement program, spontaneous mutants with single or combined resistance to streptomycin (Str(r)), gentamycin (Gen(r)) or rifamycin (Rif(r)) were selected from the industrial strain of Planobispora rosea, which is the producer of thiazolylpeptide GE2270. Among the mutants resistant to each single antibiotic, higher producers occurred more frequently (60%) among Gen(r) than in Rif(r) (10%) and Str(r) (24%) populations. Two Gen(r) mutants showed up to 1.5-fold improvement in GE2270 production while single resistant mutants Str(r) and Rif(r) produced slightly more than the parental strains. The combination of Str(r) and Rif(r) in the same strain improved GE2270 yield up to 1.7-fold. Finally, a higher GE2270 producing strain (1.8-fold improvement with respect to the parental strain) was selected among those mutants with triple resistance to streptomycin, rifamycin and gentamycin. A hierarchical increase in aerial mycelium and spore formation was observed which paralleled GE2270 production improvement.

  3. The effects of replacement of antibiotics with by-products of oriental medicinal plants on growth performance and meat qualities in fattening pigs.

    Science.gov (United States)

    Kang, Suk Nam; Chu, Gyo Moon; Song, Young Min; Jin, Sang Keun; Hwang, In Ho; Kim, Il Suk

    2012-03-01

    The effect of by-products of oriental medicinal plants (OMP; T1) containing 0.03% herb extracts (T2) or 0.1% aminolevulinic acid (T3) on the production performance of swine during the finishing period and on its meat quality were investigated. No significant differences were found in the weight gain, feed intake and feed conversion rate among the tested groups (P > 0.05). But the treated group showed higher (P meat cholesterol content (38.42 mg/100 g) compared to the other groups (P vitamin E content of the muscle in the treated groups was higher compared to the control group. No antibiotic content was detected in all treated and control samples. The values of the volatile basic nitrogen (VBN) and thiobarbituric acid reactive substance (TBARS) of the treated groups were significantly lower (P < 0.01) than the control group. The treated groups had significantly better (P < 0.05) sensory-test scores for color, flavor, off-flavor and total acceptability compared to the control group. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

  4. Immune modulation of innate immunity as alternatives-to-antibiotics strategies to mitigate the use of drugs in poultry production.

    Science.gov (United States)

    Lillehoj, H S; Lee, K W

    2012-06-01

    Following is invited commentary on the symposium "A Crystal Ball Look into the Future of…" delivered July 16, 2011, at the Poultry Science Association's 100th annual meeting, St. Louis, Missouri. The symposium examined various aspects that will impact the future of poultry production over the next 10 to 20 yr. Topics included genetics, nutrition, incubation, and bird health. This paper deals with various aspects of future issues affecting global feeding and nutrition of poultry.

  5. Comparative efficacy of three antibiotic products for the treatment and prevention of subclinical mastitis during the dry period.

    Science.gov (United States)

    Ziv, G; Storper, M; Saran, A

    1981-04-01

    The comparative efficacy of a product containing 500 mg benzathine cloxacillin (Orbenin D.C.). another product containing 100 mg nafcillin, 300 mg procaine benzylpenicillin and 100 mg dihydrostreptomycin (Nafpenzal D.C.) and a third product containing 250 mg cephalonium (Cepravin D.C.), in the elimination and prevention of mastitis due to gram-positive microorganisms during the dry period was investigated in 1253 cows located in 14 herds in Israël. Although more uniform results were observed after treatment with Nafpenzal D.C. differences among herds were rather large. The mean cure rate for Staphylococcus aureus quarter infections was 81.4 per cent. New S. aureus infections which occurred between drying off and post calving sampling time were found in 7.0 per cent of the quarters. Dry period therapy reduced infection level with S. aureus from 13.5 per cent of quarters to 8.0 per cent. A similar proportional decrease was found in infection level due to non-agalactiae Streptococcus quarter infections.

  6. Inferring relationships between clinical mastitis, productivity and fertility: a recursive model application including genetics, farm associated herd management, and cow-specific antibiotic treatments.

    Science.gov (United States)

    Rehbein, Pia; Brügemann, Kerstin; Yin, Tong; V Borstel, U König; Wu, Xiao-Lin; König, Sven

    2013-10-01

    respect to the previous LCM was close to zero. Estimated recursive effects between SCS and CM were positive, implying strong phenotypic impacts between both traits. Structural equation coefficients explained a detrimental impact of CM on female fertility traits CTFS and SFI. The cow-specific CM treatment had no significant impact on performance traits in the ongoing lactation. For most treatments, beta-lactam-antibiotics were used, but test-day SCS and production traits after the beta-lactam-treatment were comparable to those after other antibiotic as well as homeopathic treatments. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Tetracycline antibiotics transfer from contaminated milk to dairy products and the effect of the skimming step and pasteurisation process on residue concentrations.

    Science.gov (United States)

    Gajda, Anna; Nowacka-Kozak, Ewelina; Gbylik-Sikorska, Malgorzata; Posyniak, Andrzej

    2018-01-01

    The presence of antibiotics in raw milk and milk derivatives poses a threat to human health and can negatively affect the dairy industry. Therefore, the main object of this study was to investigate the transfer of oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC) and doxycycline (DC) from raw, experimental milk contaminated with tetracyclines (TCs) to different dairy products: cream, butter, buttermilk, sour milk, whey, curd and cheese. Additionally the effect of the skimming process on TCs concentrations was tested, as well as the influence of low-temperature long-time pasteurisation. The analyses of TCs in milk and dairy products were performed by an LC-MS/MS method. In order to determine TCs residues in dairy products, an analytical method was developed with the same extraction step for all matrices. TCs molecules were inhomogenously distributed between the milk derivative fractions. The highest concentrations were determined in curd and cheese in the ranges 320-482 µg/kg and 280-561 µg/kg, respectively. Low levels of TCs in butter and whey were observed (11.8-41.2 µg/kg). TCs were found in sour milk (66.0-111 µg/kg), cream (85.0-115 µg/kg) and buttermilk (196-221 µg/kg) at much higher levels than in butter and whey, but lower than in curd and cheese. During the skimming process, the highest yield of cream was obtained after the raw milk was held at 2-8°C for 24 h. The differences in concentrations of TCs between whole milk and skimmed milk, expressed as percentages of recovery, were below 19% (recoveries in excess of 81%). The highest content was observed in milk and cream skimmed at 2-8°C. The degradation percentages for TCs during the pasteurisation process (63°C for 30 min) were below 19%.

  8. Prevalence and antibiotic resistance pattern of Salmonella serovars in integrated crop-livestock farms and their products sold in local markets.

    Science.gov (United States)

    Peng, Mengfei; Salaheen, Serajus; Almario, Jose Alejandro; Tesfaye, Bezait; Buchanan, Robert; Biswas, Debabrata

    2016-05-01

    Major concern in the Mixed Crop-Livestock (MCL) farms, in which livestock and vegetables grown closely in the same facility, is cross-contamination of zoonotic bacterial pathogens especially Salmonella. To investigate the distribution of Salmonella serovars in MCL and their products, a total of 1287 pre-harvest samples from various farms and 1377 post-harvest samples from retail supermarkets in Maryland and Washington D.C. areas were collected and analysed. A total of 315 Salmonella isolates were recovered, with 17.44% and 5.88%, from MCL and conventional farms samples (P < 0.001). At post-harvest level, the prevalence of Salmonella was 30.95%, 19.83%, and 8.38% in chicken meat (P < 0.001) from farmers, organic, and conventional retail markets respectively, and 16.81% and 6.06% in produce products (P < 0.001) from farmers and organic retail markets, but none from conventional retail markets. From the isolated Salmonella, 34.50% was confirmed S. Typhimurium, followed by S. Heidelberg (10.86%) and S. Enteritidis (9.90%). The overall multi-antibiotic resistance in recovered Salmonella was 23.81% versus 4.55% in conventional and MCL farms (P = 0.004) and 66.67% versus 7.76% in conventional and farmers markets (P < 0.001). Overall the data reveals higher Salmonella risks in MCL farms' environment and their products sold in farmers markets and warrants taking necessary measures to limit Salmonella transmission. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  9. Use of organic acids and competitive exclusion product as an alternative to antibiotic as a growth promoter in the raising of commercial turkeys.

    Science.gov (United States)

    Milbradt, E L; Okamoto, A S; Rodrigues, J C Z; Garcia, E A; Sanfelice, C; Centenaro, L P; Andreatti Filho, R L

    2014-07-01

    A study was conducted to investigate the effects of organic acids (OA) and competitive exclusion product (CE) on growth performance, intestinal morphology, and concentration of volatile fatty acids in the cecal content. The experiment lasted for 10 wk. Four hundred twenty 1-d-old female commercial cross turkey poults (British United Turkeys, BUT Big 9) were distributed into 4 treatments with 5 replicates/pen of 21 birds each. The birds were fed a basal diet without growth promoter (control), diet with lincomycin (44 mg/kg), diet with organic acids (2 g/kg), and diet with product of CE (10(9) cfu/kg). Dietary levels of other nutrients, housing, and general management practices were similar for all treatments. On the first week (d 0-7), the BW and BW gain of the birds that fed diets with OA were lower than in the control group. In the fattening phase (d 28-70), the feed intake of the OA-treated group was lower than compared with the control. The birds that received diet with OA and CE product presented higher concentrations of propionic acid, at 14 d, and butyric acid in cecal content at 28, 56, and 70 d, compared with the control. Dietary inclusion of additives had no significant effects on intestinal villus height, crypt depth, and villus:crypt ratio. Organic acids had negative effects either on early gain or feed intake throughout the study. Because the test was conducted under controlled experimental conditions, the additives that showed results similar to those found by using antibiotics should be studied further in commercial farms to obtain results that can be incorporated into practice. © 2014 Poultry Science Association Inc.

  10. Identification of staphylococci from bovine mastitis and an examination of their susceptibility to antibiotics and beta-lactamase production.

    Science.gov (United States)

    Matsunaga, T; Yoshida, T; Kamata, S; Uchida, K

    1990-12-01

    Strains of Staphylococcus species isolated from bovine mastitic milk at 66 dairy farms in Japan during the period from November 1988 to May 1989 were identified, and examined for their drug susceptibility and beta-lactamase production in order to clarify an epidemiological aspect of bovine mastitis caused by staphylococci. The results of bacteriological identification showed that the most predominant species was S. xylosus. Other major species isolated were S. aureus, S. sciuri and S. hyicus. Thirty-eight (71.7%) isolates of S. xylosus, 21 (45.7%) of S. aureus and 5 (71.4%) of S. epidermidis were positive for beta-lactamase production. Most of the beta-lactamase-producers of S. aureus were classified as high producers, although all of the beta-lactamase-positive S. xylosus isolates remained to be low producers. All isolates of S. aureus were sensitive to methicillin and cloxacillin at 6.25 micrograms/ml and 1.56 micrograms/ml, respectively, and none of methicillin-resistant S. aureus were detected. Isolates of other species were considered to be susceptible to 6 beta-lactams, in contrast to human isolates, but antibacterial activities of penicillin G and ampicillin were affected more strongly by beta-lactamase than those of methicillin, cloxacillin, cefazolin and cefoperazone.

  11. Demographics of antibiotic persistence

    DEFF Research Database (Denmark)

    Kollerova, Silvia; Jouvet, Lionel; Steiner, Ulrich

    Persister cells, cells that can survive antibiotic exposure but lack heritable antibiotic resistance, are assumed to play a crucial role for the evolution of antibiotic resistance. Persistence is a stage associated with reduced metabolic activity. Most previous studies have been done on batch...... even play a more prominent role for the evolution of resistance and failures of medical treatment by antibiotics as currently assumed....

  12. Antibiotics from predatory bacteria

    Directory of Open Access Journals (Sweden)

    Juliane Korp

    2016-03-01

    Full Text Available Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.

  13. Metabolic activity, urease production, antibiotic resistance and virulence in dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus.

    Science.gov (United States)

    Vandecandelaere, Ilse; Van Nieuwerburgh, Filip; Deforce, Dieter; Coenye, Tom

    2017-01-01

    In this paper, the metabolic activity in single and dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus isolates was investigated. Our results demonstrated that there was less metabolic activity in dual species biofilms compared to S. aureus biofilms. However, this was not observed if S. aureus and S. epidermidis were obtained from the same sample. The largest effect on metabolic activity was observed in biofilms of S. aureus Mu50 and S. epidermidis ET-024. A transcriptomic analysis of these dual species biofilms showed that urease genes and genes encoding proteins involved in metabolism were downregulated in comparison to monospecies biofilms. These results were subsequently confirmed by phenotypic assays. As metabolic activity is related to acid production, the pH in dual species biofilms was slightly higher compared to S. aureus Mu50 biofilms. Our results showed that S. epidermidis ET-024 in dual species biofilms inhibits metabolic activity of S. aureus Mu50, leading to less acid production. As a consequence, less urease activity is required to compensate for low pH. Importantly, this effect was biofilm-specific. Also S. aureus Mu50 genes encoding virulence-associated proteins (Spa, SplF and Dps) were upregulated in dual species biofilms compared to monospecies biofilms and using Caenorhabditis elegans infection assays, we demonstrated that more nematodes survived when co-infected with S. epidermidis ET-024 and S. aureus mutants lacking functional spa, splF or dps genes, compared to nematodes infected with S. epidermidis ET-024 and wild- type S. aureus. Finally, S. epidermidis ET-024 genes encoding resistance to oxacillin, erythromycin and tobramycin were upregulated in dual species biofilms and increased resistance was subsequently confirmed. Our data indicate that both species in dual species biofilms of S. epidermidis and S. aureus influence each other's behavior, but additional studies are required necessary to elucidate the exact

  14. Marine Myxobacteria as a Source of Antibiotics—Comparison of Physiology, Polyketide-Type Genes and Antibiotic Production of Three New Isolates of Enhygromyxa salina

    Directory of Open Access Journals (Sweden)

    Gabriele Bierbaum

    2010-09-01

    Full Text Available Three myxobacterial strains, designated SWB004, SWB005 and SWB006, were obtained from beach sand samples from the Pacific Ocean and the North Sea. The strains were cultivated in salt water containing media and subjected to studies to determine their taxonomic status, the presence of genes for the biosynthesis of polyketides and antibiotic production. 16S rDNA sequence analysis revealed the type strain Enhygromyxa salina SHK-1T as their closest homolog, displaying between 98% (SWB005 and 99% (SWB004 and SWB006 sequence similarity. All isolates were rod-shaped cells showing gliding motility and fruiting body formation as is known for myxobacteria. They required NaCl for growth, with an optimum concentration of around 2% [w/v]. The G + C-content of genomic DNA ranged from 63.0 to 67.3 mol%. Further, the strains were analyzed for their potential to produce polyketide-type structures. PCR amplified ketosynthase-like gene fragments from all three isolates enhances the assumption that these bacteria produce polyketides. SWB005 was shown to produce metabolites with prominent antibacterial activity, including activity towards methicillin resistant Staphylococcus aureus (MRSA and Staphylococcus epidermidis (MRSE.

  15. Natural bioactive compounds: antibiotics | Dezfully | Journal of ...

    African Journals Online (AJOL)

    Antibiotics are powerful therapeutic agents that are produced by diverse living organisms. Over the last several decades, natural bioactive products particularly antibiotics have continued to play a significant role in drug discovery and has expanded the process for developing drugs with high degree of therapeutic index and ...

  16. Departamento de Biologia : 40 Anos de atividades 1976 - 2016 : 4- Expedições Científicas

    OpenAIRE

    Tavares, João

    2016-01-01

    4º Cartaz exposto no Hall do Complexo Científico durante a Jornada do Departamento de Biologia, no âmbito das Comemorações do 40º Aniversário da Universidade dos Açores (24-11-2016) As Expedições Científicas do Departamento de Biologia remontam ao início da atividade da Instituição, tendo sido efetuadas em todas as ilhas dos Açores e da Madeira. Foram desenvolvidas em períodos de pausa letiva e contaram com o apoio logístico das instituições e comunidades visitadas. Os relatórios dos tr...

  17. Combating antibiotic resistance - A Policy Roadmap to Reduce Use of Medically Important Antibiotics in Livestock

    DEFF Research Database (Denmark)

    Price, Lance B.; Newland, Jason; Bole, Aparna

    edical and public health organizations around the world agree that more prudent use of antibiotics in human medicine and in livestock production is paramount to slow the spread of antibiotic resistance. Of particular concern is the widespread use of antibiotics important to human medicine in food...... roadmap to help move the U.S. forward in addressing the contribution of livestock antibiotic use to the growing global threat of antibiotic resistance. The policy roadmap consists of 11 core policy recommendations that are aimed at a broad set of stakeholders: federal, state and local policymakers, food...... companies, institutional food purchasers (i.e. hospitals, schools and universities), and medical groups. The recommendations are split into three key areas: 1) decreasing livestock use of medically important antibiotics; 2) monitoring livestock antibiotic use, and 3) enhancing surveillance and data...

  18. Regulation of the AbrA1/A2 two-component system in Streptomyces coelicolor and the potential of its deletion strain as a heterologous host for antibiotic production.

    Directory of Open Access Journals (Sweden)

    Sergio Rico

    Full Text Available The Two-Component System (TCS AbrA1/A2 from Streptomyces coelicolor M145 is a negative regulator of antibiotic production and morphological differentiation. In this work we show that it is able to auto-regulate its expression, exerting a positive induction of its own operon promoter, and that its activation is dependent on the presence of iron. The overexpression of the abrA2 response regulator (RR gene in the mutant ΔabrA1/A2 results in a toxic phenotype. The reason is an excess of phosphorylated AbrA2, as shown by phosphoablative and phosphomimetic AbrA2 mutants. Therefore, non-cognate histidine kinases (HKs or small phospho-donors may be responsible for AbrA2 phosphorylation in vivo. The results suggest that in the parent strain S. coelicolor M145 the correct amount of phosphorylated AbrA2 is adjusted through the phosphorylation-dephosphorylation activity rate of the HK AbrA1. Furthermore, the ABC transporter system, which is part of the four-gene operon comprising AbrA1/A2, is necessary to de-repress antibiotic production in the TCS null mutant. Finally, in order to test the possible biotechnological applications of the ΔabrA1/A2 strain, we demonstrate that the production of the antitumoral antibiotic oviedomycin is duplicated in this strain as compared with the production obtained in the wild type, showing that this strain is a good host for heterologous antibiotic production. Thus, this genetically modified strain could be interesting for the biotechnology industry.

  19. Detection of Tox A Gene in Pseudomonas aeruginosa Strains Isolated from Dairy Products Using PCR and Determining the Antibiotic Resistance Pattern

    Directory of Open Access Journals (Sweden)

    Faeze Zadsafar

    2017-08-01

    Conclusion: Due to high presence of Pseudomonas aeruginosa in raw milk and existence of antibiotic resistance genes in this bacterium, applying appropriate strategies for hygiene control in animal husbandries, is necessary to prevent the spread of bacteria.

  20. Antibiotic multiresistance analysis of mesophilic and psychrotrophic Pseudomonas spp. isolated from goat and lamb slaughterhouse surfaces throughout the meat production process

    National Research Council Canada - National Science Library

    Lavilla Lerma, Leyre; Benomar, Nabil; Casado Muñoz, María del Carmen; Gálvez, Antonio; Abriouel, Hikmate

    2014-01-01

    The aim of this study was to investigate the phenotypic and genotypic antibiotic resistance profiles of pseudomonads isolated from surfaces of a goat and lamb slaughterhouse, which were representative...

  1. Antibiotic resistance and biofilm production among the strains of Staphylococcus aureus isolated from pus/wound swab samples in a tertiary care hospital in Nepal.

    Science.gov (United States)

    Belbase, Ankit; Pant, Narayan Dutt; Nepal, Krishus; Neupane, Bibhusan; Baidhya, Rikesh; Baidya, Reena; Lekhak, Binod

    2017-03-23

    The increasing drug resistance along with inducible clindamycin resistance, methicillin resistance and biofilm production among the strains of Staphylococcus aureus are present as the serious problems to the successful treatment of the infections caused by S. aureus. So, the main objectives of this study were to determine the antimicrobial susceptibility patterns along with the rates of inducible clindamycin resistance, methicillin resistance and biofilm production among the strains of S. aureus isolated from pus/wound swab samples. A total of 830 non-repeated pus/wound swab samples were processed using standard microbiological techniques. The colonies grown were identified on the basis of colony morphology, Gram's stain and biochemical tests. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique. Detection of inducible clindamycin resistance was performed by D test, while detection of methicillin resistant S. aureus (MRSA) was performed by determination of minimum inhibitory concentration of oxacillin by agar dilution method. Similarly, detection of biofilm formation was performed by microtiter plate method. Strains showing resistance to three or more than three different classes of antibiotics were considered multidrug resistant. Total 76 samples showed the growth of S. aureus, among which 36 (47.4%) contained MRSA and 17 (22.4%) samples were found to have S. aureus showing inducible clindamycin resistance. Among the S. aureus isolated from outpatients, 41.9% were MRSA. Highest rates of susceptibility of S. aureus were seen toward linezolid (100%) and vancomycin (100%). Similarly, S. aureus isolated from 35 (46.1%) samples were found to be biofilm producers. Higher rate of inducible clindamycin resistance was seen among MRSA in comparison to methicillin susceptible S. aureus (MSSA). Similarly, higher rates of multidrug resistance and methicillin resistance were found among biofilm producing strains in comparison to biofilm non

  2. The two kinases, AbrC1 and AbrC2, of the atypical two-component system AbrC are needed to regulate antibiotic production and differentiation in Streptomyces coelicolor.

    Directory of Open Access Journals (Sweden)

    Héctor eRodríguez

    2015-05-01

    Full Text Available Two-component systems (TCSs are the most important sensing mechanisms in bacteria. In Streptomyces, Two-component systems (TCSs are the most important sensing mechanisms in bacteria. In Streptomyces, TCSs-mediated responses to environmental stimuli are involved in the regulation of antibiotic production. This study examines the individual role of two histidine kinases (HKs, AbrC1 and AbrC2, which form part of an atypical TCS in Streptomyces coelicolor. qRT-PCR analysis of the expression of both kinases demonstrated that both are expressed at similar levels in NB and NMMP media. Single deletion of abrC1 elicited a significant increase in antibiotic production, while deletion of abrC2 did not have any clear effect. The origin of this phenotype, probably related to the differential phosphorylation ability of the two kinases, was also explored indirectly, analyzing the toxic phenotypes associated with high levels of phosphorylated RR. The higher the AbrC3 regulator phosphorylation rate, the greater the cell toxicity. For the first time, the present work shows in Streptomyces the combined involvement of two different HKs in the response of a regulator to environmental signals. Regarding the possible applications of this research, the fact that an abrC1 deletion mutant overproduces three of the S. coelicolor antibiotics makes this strain an excellent candidate as a host for the heterologous production of secondary metabolites.

  3. Sublethal Concentrations of Antibiotics Cause Shift to Anaerobic Metabolism in Listeria monocytogenes and Induce Phenotypes Linked to Antibiotic Tolerance

    DEFF Research Database (Denmark)

    Knudsen, Gitte Maegaard; Fromberg, Arvid; Ng, Yin

    2016-01-01

    The human pathogenic bacterium Listeria monocytogenes is exposed to antibiotics both during clinical treatment and in its saprophytic lifestyle. As one of the keys to successful treatment is continued antibiotic sensitivity, the purpose of this study was to determine if exposure to sublethal...... antibiotic concentrations would affect the bacterial physiology and induce antibiotic tolerance. Transcriptomic analyses demonstrated that each of the four antibiotics tested caused an antibiotic-specific gene expression pattern related to mode-of-action of the particular antibiotic. All four antibiotics...... caused the same changes in expression of several metabolic genes indicating a shift from aerobic to anaerobic metabolism and higher ethanol production. A mutant in the bifunctional acetaldehyde-CoA/alcohol dehydrogenase encoded by Imo1634 did not have altered antibiotic tolerance. However, a mutant...

  4. The efficacy of immediate versus delayed antibiotic administration on bacterial growth and biofilm production of selected strains of uropathogenic Escherichia coli and Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Leah Gandee

    2015-02-01

    Full Text Available Purpose The treatment of urinary tract infections (UTI with antibiotics is commonly used, but recurrence and antibiotic resistance have been growing and concerning clinicians. We studied whether the rapid onset of a protective biofilm may be responsible for the lack of effectiveness of antibiotics against selected bacteria. Materials and Methods Two established uropathogenic Escherichia coli strains, UTI89 and CFT073, and two Pseudomonas aeruginosa strains, PA01 and Boston-41501, were studied to establish a reliable biofilm formation process. Bacterial growth (BG was determined by optical density at 600 nm (OD 600 using a spectrophotometer, while biofilm formation (BF using crystal violet staining was measured at OD 550. Next, these bacterial strains were treated with clinically relevant antibiotics, ciprofloxacin HCl (200 ng/mL and 2 μg/mL, nitrofurantoin (20 μg/mL and 40 μg/mL and ampicillin (50 μg/mL at time points of 0 (T0 or after 6 hours of culture (T6. All measurements, including controls (bacteria -1% DMSO, were done in triplicates and repeated three times for consistency. Results The tested antibiotics effectively inhibited both BG and BF when administered at T0 for UPEC strains, but not when the antibiotic administration started 6 hours later. For Pseudomonas strains, only Ciprofloxacin was able to significantly inhibit bacterial growth at T0 but only at the higher concentration of 2 μg/mL for T6. Conclusion When established UPEC and Pseudomonas bacteria were allowed to culture for 6 hours before initialization of treatment, the therapeutic effect of selected antibiotics was greatly suppressed when compared to immediate treatment, probably as a result of the protective nature of the biofilm.

  5. The Shared Antibiotic Resistome of Soil Bacteria and Human Pathogens

    DEFF Research Database (Denmark)

    Forsberg, Kevin J.; Reyes, Alejandro; Wang, Bin

    2012-01-01

    From Farm to Clinic?Soil organisms have long been assumed to be an important source of antibiotic resistance genes, in part because of antibiotic-treated livestock and in part because of the natural ecology of antibiotic production in the soil. Forsberg et al. (p. 1107) developed a metagenomic...

  6. Antibiotic like-substances produced by some trichophytic ...

    African Journals Online (AJOL)

    Antibiotic production by dermatophytic fungi was demonstrated. Among 10 anthropophilic dermatophytes strains tested for their ability to produce antibiotics, four were found to be producers. The outcome for a qualitative identification of the produced antibiotics reveals four types ; a penicillin-like substance produced by ...

  7. Antibiotics and antibiotic resistance in water environments.

    Science.gov (United States)

    Baquero, Fernando; Martínez, José-Luis; Cantón, Rafael

    2008-06-01

    Antibiotic-resistant organisms enter into water environments from human and animal sources. These bacteria are able to spread their genes into water-indigenous microbes, which also contain resistance genes. On the contrary, many antibiotics from industrial origin circulate in water environments, potentially altering microbial ecosystems. Risk assessment protocols for antibiotics and resistant bacteria in water, based on better systems for antibiotics detection and antibiotic-resistance microbial source tracking, are starting to be discussed. Methods to reduce resistant bacterial load in wastewaters, and the amount of antimicrobial agents, in most cases originated in hospitals and farms, include optimization of disinfection procedures and management of wastewater and manure. A policy for preventing mixing human-originated and animal-originated bacteria with environmental organisms seems advisable.

  8. Bacteriocins ? Exploring Alternatives to Antibiotics in Mastitis Treatment

    OpenAIRE

    Pieterse, Rene?; Todorov, Svetoslav D.

    2010-01-01

    Mastitis is considered to be the most costly disease affecting the dairy industry. Management strategies involve the extensive use of antibiotics to treat and prevent this disease. Prophylactic dosages of antibiotics used in mastitis control programmes could select for strains with resistance to antibiotics. In addition, a strong drive towards reducing antibiotic residues in animal food products has lead to research in finding alternative antimicrobial agents. In this review we have focus on ...

  9. Revisiting Antibiotic Resistance Spreading in Wastewater Treatment Plants – Bacteriophages as a Much Neglected Potential Transmission Vehicle

    National Research Council Canada - National Science Library

    Rolf Lood; Gizem Ertürk; Bo Mattiasson

    2017-01-01

    .... Focus to limit the spread of antibiotic resistance by reducing the usage of antibiotics in health care, veterinary applications, and meat production, have been implemented, limiting the exposure...

  10. Identification and molecular phylogeny of coagulase-negative staphylococci isolates from Minas Frescal cheese in southeastern Brazil: Superantigenic toxin production and antibiotic resistance.

    Science.gov (United States)

    Casaes Nunes, Raquel Soares; Pires de Souza, Camilla; Pereira, Karen Signori; Del Aguila, Eduardo Mere; Flosi Paschoalin, Vânia Margaret

    2016-04-01

    Minas Frescal is a typical Brazilian fresh cheese and one of the most popular dairy products in the country. This white soft, semiskimmed, nonripened cheese with high moisture content is obtained by enzymatic coagulation of cow milk using calf rennet or coagulants, usually in industrial dairy plants, but is also manufactured in small farms. Contamination of Minas Frescal by several staphylococci has been frequently reported. Coagulase-negative staphylococci (CNS) strains are maybe the most harmful, as they are able to produce heat-stable enterotoxins with super antigenic activities in food matrices, especially in dairy products such as soft cheeses. The aim of the present study was to investigate the presence of CNS strains in Minas Frescal marketed in southeastern Brazil concerning the risk of staphylococci food poisoning by the consumption of improperly manufactured cheese and the possibility of these food matrices being a reservoir of staphylococcal resistance to antimicrobials. Ten distinct CNS strains were found in 6 cheeses from distinct brands. The most frequent species were Staphylococcus saprophyticus (40%), Staphylococcus xylosus (30%), Staphylococcus sciuri (20%), and Staphylococcus piscifermentans (10%). Three strains were identified to the Staphylococcus genera. Three major species groups composed of 3 refined clusters were grouped by phylogenetic analyses with similarities over to 90%. All CNS strains carried multiple enterotoxin genes, with high incidence of sea and seb (90 and 70%, respectively), followed by sec/see, seh/sei, and sed with intermediate incidence (60, 50, and 40%, respectively), and, finally, seg/selk/selq/selr and selu with the lowest incidence (20 and 10%, respectively). Real-time reverse transcription PCR and ELISA assays confirmed the enteroxigenic character of the CNS strains, which expressed and produced the enterotoxins in vitro. The CNS strains showed multiresistance to antimicrobial agents such as β-lactams, vancomycin, and

  11. Know When Antibiotics Work

    Centers for Disease Control (CDC) Podcasts

    2015-04-15

    This podcast provides a brief background about antibiotics and quick tips to help prevent antibiotic resistance.  Created: 4/15/2015 by Division of Bacterial Diseases (DBD), National Center for Immunization and Respiratory Disease (NCIRD), Get Smart: Know When Antibiotics Work Program.   Date Released: 4/16/2015.

  12. Prevalence of antibiotic-resistant E. coli in retail chicken: comparing conventional, organic, kosher, and raised without antibiotics

    OpenAIRE

    Millman, Jack M; Waits, Kara; Grande, Heidi; Marks, Ann R; Marks, Jane C; Price, Lance B; Hungate, Bruce A

    2013-01-01

    Retail poultry products are known sources of antibiotic-resistant Escherichia coli, a major human health concern. Consumers have a range of choices for poultry, including conventional, organic, kosher, and raised without antibiotics (RWA) – designations that are perceived to indicate differences in quality and safety. However, whether these categories vary in the frequency of contamination with antibiotic-resistant E. coli is unknown. We examined the occurrence of antibiotic-resistant E. coli...

  13. Inducing optimal substitution between antibiotics under open access to the resource of antibiotic susceptibility.

    Science.gov (United States)

    Herrmann, Markus; Nkuiya, Bruno

    2017-06-01

    This paper designs a bio-economic model to examine the use of substitute antibiotic drugs (analogs) sold by an industry that has open access to the resource of the antibiotic class's susceptibility (treatment effectiveness). Antibiotics are characterized by different expected recovery rates and production costs, which in conjunction with the class's treatment susceptibility determines their relative effectiveness. Our analysis reveals that the high-quality antibiotic drug loses its comparative advantage over time making the low-quality drug the treatment of last resort in the market equilibrium and the social optimum when antibiotic susceptibility cannot replenish. However, when antibiotic susceptibility is renewable, both antibiotics may be used in the long run, and the comparative advantage of the high-quality drug may be restored in the social optimum that allows lowering infection in the long run. We develop the optimal tax/subsidy scheme that would induce antibiotic producers under open access to behave optimally and account for the social cost of infection and value of antibiotic susceptibility. We show that the welfare loss associated with the uncorrected open-access allocation is highest; when the resource of antibiotic susceptibility is non-renewable, high morbidity costs are incurred by individuals, and low social discount rates apply. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Molecular Regulation of Antibiotic Biosynthesis in Streptomyces

    Science.gov (United States)

    Liu, Gang; Chandra, Govind; Niu, Guoqing

    2013-01-01

    SUMMARY Streptomycetes are the most abundant source of antibiotics. Typically, each species produces several antibiotics, with the profile being species specific. Streptomyces coelicolor, the model species, produces at least five different antibiotics. We review the regulation of antibiotic biosynthesis in S. coelicolor and other, nonmodel streptomycetes in the light of recent studies. The biosynthesis of each antibiotic is specified by a large gene cluster, usually including regulatory genes (cluster-situated regulators [CSRs]). These are the main point of connection with a plethora of generally conserved regulatory systems that monitor the organism's physiology, developmental state, population density, and environment to determine the onset and level of production of each antibiotic. Some CSRs may also be sensitive to the levels of different kinds of ligands, including products of the pathway itself, products of other antibiotic pathways in the same organism, and specialized regulatory small molecules such as gamma-butyrolactones. These interactions can result in self-reinforcing feed-forward circuitry and complex cross talk between pathways. The physiological signals and regulatory mechanisms may be of practical importance for the activation of the many cryptic secondary metabolic gene cluster pathways revealed by recent sequencing of numerous Streptomyces genomes. PMID:23471619

  15. Laboratory Evaluation of Expedient Low-Temperature Concrete Admixtures for Repairing Blast Holes in Cold Weather

    Science.gov (United States)

    2013-01-08

    ambient temperature ranges of −10 to 0°C. 2. use admixtures available through the Army supply system in Afghani- stan (existing supplies in area of...Price: $13.25 Calcium Nitrate Fertilizer Pellets: Atlantis Hydroponics www.atlantishydroponics.com 888.305.4450 Product info: “Calcium

  16. Differential resistance and the importance of antibiotic production in Acromyrmex echinatior leaf-cutting ant castes towards the entomopathogenic fungus Aspergillus nomius

    DEFF Research Database (Denmark)

    Poulsen, Michael; Hughes, William Owen Hamar; Boomsma, Jacobus Jan

    2006-01-01

    Paired exocrine metapleural glands are present in almost all ants and produce compounds with antibiotic properties towards a variety of pathogenic fungi and bacteria. In Acromyrmex leaf-cutting ants, small workers have relatively large metapleural glands compared to large workers, and thus harbour...

  17. Quantitative targeted and retrospective data analysis of relevant pesticides, antibiotics and mycotoxins in bakery products by liquid chromatography-single-stage Orbitrap mass spectrometry.

    Science.gov (United States)

    De Dominicis, Emiliano; Commissati, Italo; Gritti, Elisa; Catellani, Dante; Suman, Michele

    2015-01-01

    In addition to 'traditional' multi-residue and multi-contaminant multiple reaction monitoring (MRM) mass spectrometric techniques devoted to quantifying a list of targeted compounds, the global food industry requires non-targeted methods capable of detecting other possible potentially hazardous compounds. Ultra-high-performance liquid chromatography combined with a single-stage Orbitrap high-resolution mass spectrometer (UHPLC-HRMS Exactive™-Orbitrap Technology) was successfully exploited for the complete selective and quantitative determination of 33 target compounds within three major cross categories (pesticides, antibiotics and mycotoxins) in bakery matrices (specifically milk, wheat flour and mini-cakes). Resolution was set at 50 000 full width at half maximum (FWHM) to achieve the right compromise between an adequate scan speed and selectivity, allowing for the limitations related to the necessary generic sample preparation approach. An exact mass with tolerance of 5 ppm and minimum peak threshold of 10 000 units were fixed as the main identification conditions, including retention time and isotopic pattern as additional criteria devoted to greatly reducing the risk of false-positive findings. The full validation for all the target analytes was performed: linearity, intermediate repeatability and recovery (28 analytes within 70-120%) were positively assessed; furthermore, limits of quantification between 5 and 100 µg kg(-1) (with most of the analytes having a limit of detection below 6 µg kg(-1)) indicate good performance, which is compatible with almost all the regulatory needs. Naturally contaminated and fortified mini-cakes, prepared through combined use of industrial and pilot plant production lines, were analysed at two different concentration levels, obtaining good overall quantitative results and providing preliminary indications of the potential of full-scan HRMS cluster analysis. The effectiveness of this analytical approach was also tested in

  18. Ribosomal Antibiotics: Contemporary Challenges

    Directory of Open Access Journals (Sweden)

    Tamar Auerbach-Nevo

    2016-06-01

    Full Text Available Most ribosomal antibiotics obstruct distinct ribosomal functions. In selected cases, in addition to paralyzing vital ribosomal tasks, some ribosomal antibiotics are involved in cellular regulation. Owing to the global rapid increase in the appearance of multi-drug resistance in pathogenic bacterial strains, and to the extremely slow progress in developing new antibiotics worldwide, it seems that, in addition to the traditional attempts at improving current antibiotics and the intensive screening for additional natural compounds, this field should undergo substantial conceptual revision. Here, we highlight several contemporary issues, including challenging the common preference of broad-range antibiotics; the marginal attention to alterations in the microbiome population resulting from antibiotics usage, and the insufficient awareness of ecological and environmental aspects of antibiotics usage. We also highlight recent advances in the identification of species-specific structural motifs that may be exploited for the design and the creation of novel, environmental friendly, degradable, antibiotic types, with a better distinction between pathogens and useful bacterial species in the microbiome. Thus, these studies are leading towards the design of “pathogen-specific antibiotics,” in contrast to the current preference of broad range antibiotics, partially because it requires significant efforts in speeding up the discovery of the unique species motifs as well as the clinical pathogen identification.

  19. Antibiotics and the burn patient.

    Science.gov (United States)

    Ravat, François; Le-Floch, Ronan; Vinsonneau, Christophe; Ainaud, Pierre; Bertin-Maghit, Marc; Carsin, Hervé; Perro, Gérard

    2011-02-01

    Infection is a major problem in burn care and especially when it is due to bacteria with hospital-acquired multi-resistance to antibiotics. Moreover, when these bacteria are Gram-negative organisms, the most effective molecules are 20 years old and there is little hope of any new product available even in the distant future. Therefore, it is obvious that currently available antibiotics should not be misused. With this aim in mind, the following review was conducted by a group of experts from the French Society for Burn Injuries (SFETB). It examined key points addressing the management of antibiotics for burn patients: when to use or not, time of onset, bactericidia, combination, adaptation, de-escalation, treatment duration and regimen based on pharmacokinetic and pharmacodynamic characteristics of these compounds. The authors also considered antibioprophylaxis and some other key points such as: infection diagnosis criteria, bacterial inoculae and local treatment. French guidelines for the use of antibiotics in burn patients have been designed up from this work. Copyright © 2009 Elsevier Ltd and ISBI. All rights reserved.

  20. An overview of advanced technologies for selection of probiotics and their expediency: A review.

    Science.gov (United States)

    Yadav, Ruby; Shukla, Pratyoosh

    2017-10-13

    It has become easy to identify and select an appropriate microorganism with the advancement in various molecular biology and analytical techniques. The majority of the novel techniques are being implemented for the identification and characterization of microorganisms used for probiotic application. Standard microbial techniques such as biochemical testing and culture techniques routinely used for probiotic microbes screening, identification and selection. However, these standard techniques may not give complete information on the microbes that can be used for probiotic production. Furthermore, alternative molecular and analytical techniques such as 16S and 23S ribosomal DNA sequencing, RNA analysis by reverse transcriptase (RT-PCR), fluorescent in situ hybridization (FISH), quantitative analysis by real time PCR (RT-PCR or qPCR) and fluorescent activated cell sorting (FACS) are potentially used to confirm and select all types of lactic acid microorganism. All these approaches can be employed in the screening and selection of appropriate lactic acid bacteria which can be potentially used for the production of human use probiotics in large scale fermentation. This review mainly focuses on various tools and techniques used for effective screening and selection of a better candidate bacterium for probiotic applications.

  1. Prevalence of antibiotic-resistant E. coli in retail chicken: comparing conventional, organic, kosher, and raised without antibiotics

    Science.gov (United States)

    Price, Lance B; Hungate, Bruce A

    2013-01-01

    Retail poultry products are known sources of antibiotic-resistant Escherichia coli, a major human health concern. Consumers have a range of choices for poultry, including conventional, organic, kosher, and raised without antibiotics (RWA) – designations that are perceived to indicate differences in quality and safety. However, whether these categories vary in the frequency of contamination with antibiotic-resistant E. coli is unknown. We examined the occurrence of antibiotic-resistant E. coli on raw chicken marketed as conventional, organic, kosher and RWA. From April – June 2012, we purchased 213 samples of raw chicken from 15 locations in the New York City metropolitan area. We screened E. coli isolates from each sample for resistance to 12 common antibiotics. Although the organic and RWA labels restrict the use of antibiotics, the frequency of antibiotic-resistant E. coli tended to be only slightly lower for RWA, and organic chicken was statistically indistinguishable from conventional products that have no restrictions. Kosher chicken had the highest frequency of antibiotic-resistant E. coli, nearly twice that of conventional products, a result that belies the historical roots of kosher as a means to ensure food safety. These results indicate that production methods influence the frequency of antibiotic-resistant E. coli on poultry products available to consumers. Future research to identify the specific practices that cause the high frequency of antibiotic-resistant E. coli in kosher chicken could promote efforts to reduce consumer exposure to this potential pathogen. PMID:24555073

  2. Prevalence of antibiotic-resistant E. coli in retail chicken: comparing conventional, organic, kosher, and raised without antibiotics.

    Science.gov (United States)

    Millman, Jack M; Waits, Kara; Grande, Heidi; Marks, Ann R; Marks, Jane C; Price, Lance B; Hungate, Bruce A

    2013-01-01

    Retail poultry products are known sources of antibiotic-resistant Escherichia coli, a major human health concern. Consumers have a range of choices for poultry, including conventional, organic, kosher, and raised without antibiotics (RWA) - designations that are perceived to indicate differences in quality and safety. However, whether these categories vary in the frequency of contamination with antibiotic-resistant E. coli is unknown. We examined the occurrence of antibiotic-resistant E. coli on raw chicken marketed as conventional, organic, kosher and RWA. From April - June 2012, we purchased 213 samples of raw chicken from 15 locations in the New York City metropolitan area. We screened E. coli isolates from each sample for resistance to 12 common antibiotics. Although the organic and RWA labels restrict the use of antibiotics, the frequency of antibiotic-resistant E. coli tended to be only slightly lower for RWA, and organic chicken was statistically indistinguishable from conventional products that have no restrictions. Kosher chicken had the highest frequency of antibiotic-resistant E. coli, nearly twice that of conventional products, a result that belies the historical roots of kosher as a means to ensure food safety. These results indicate that production methods influence the frequency of antibiotic-resistant E. coli on poultry products available to consumers. Future research to identify the specific practices that cause the high frequency of antibiotic-resistant E. coli in kosher chicken could promote efforts to reduce consumer exposure to this potential pathogen.

  3. [Rational use of antibiotics].

    Science.gov (United States)

    Walger, P

    2016-06-01

    International and national campaigns draw attention worldwide to the rational use of the available antibiotics. This has been stimulated by the high prevalence rates of drug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), a threatening spread of development of resistance in Gram-negative rod-shaped bacteria and the selection of Clostridium difficile with a simultaneous clear reduction in the development of new antibiotics. The implementation of antibiotic stewardship programs aims to maintain their effectiveness by a rational use of the available antibiotics. The essential target of therapy with antibiotics is successful treatment of individual patients with bacterial infections. The optimal clinical treatment results can only be achieved when the toxicity, selection of pathogens and development of resistance are minimized. This article presents the principles of a rational antibiotic therapy.

  4. Antibiotics and Breastfeeding.

    Science.gov (United States)

    de Sá Del Fiol, Fernando; Barberato-Filho, Silvio; de Cássia Bergamaschi, Cristiane; Lopes, Luciane Cruz; Gauthier, Timothy P

    2016-01-01

    During the breastfeeding period, bacterial infections can occur in the nursing mother, requiring the use of antibiotics. A lack of accurate information may lead health care professionals and mothers to suspend breastfeeding, which may be unnecessary. This article provides information on the main antibiotics that are appropriate for clinical use and the interference of these antibiotics with the infant to support medical decisions regarding the discontinuation of breastfeeding. We aim to provide information on the pharmacokinetic factors that interfere with the passage of antibiotics into breast milk and the toxicological implications of absorption by the infant. Publications related to the 20 most frequently employed antibiotics and their transfer into breast milk were evaluated. The results demonstrate that most antibiotics in clinical use are considered suitable during breastfeeding; however, the pharmacokinetic profile of each drug must be observed to ensure the resolution of the maternal infection and the safety of the infant. © 2016 S. Karger AG, Basel.

  5. High Antibiotic Consumption

    DEFF Research Database (Denmark)

    Malo, Sara; José Rabanaque, María; Feja, Cristina

    2014-01-01

    Heavy antibiotic users are those individuals with the highest exposure to antibiotics. They play an important role as contributors to the increasing risk of antimicrobial resistance. We applied different methods to identify and characterize the group of heavy antibiotic users in Spain as well...... as their exposure to antibiotics. Data on outpatient prescribing of antimicrobials (ATC J01) in 2010 were obtained from a prescription database covering Aragón (northeastern Spain). The antimicrobial consumption at the individual level was analysed both according to the volume of DDD and the number of packages...... purchased per year. Heavy antibiotic users were identified according to Lorenz curves and characterized by age, gender, and their antimicrobial prescription profile. Lorenz curves demonstrated substantial differences in the individual use of antimicrobials. Heavy antibiotic users (5% of individuals...

  6. An expedient route to substituted furans via olefin cross-metathesis

    Science.gov (United States)

    Donohoe, Timothy J.; Bower, John F.

    2010-01-01

    The olefin cross-metathesis (CM) reaction is used extensively in organic chemistry and represents a powerful method for the selective synthesis of differentially substituted alkene products. Surprisingly, efforts to integrate this remarkable process into strategies for aromatic and heteroaromatic construction have not been reported. Such structures represent key elements of the majority of small molecule drug compounds; methods for the controlled preparation of highly substituted derivatives are essential to medicinal chemistry. Here we show that the olefin CM reaction, in combination with an acid cocatalyst or subsequent Heck arylation, provides a concise and flexible entry to 2,5-di- or 2,3,5-tri-substituted furans. These cascade processes portend further opportunities for the regiocontrolled preparation of other highly substituted aromatic and heteroaromatic classes. PMID:20142508

  7. A Kinetic Dearomatization Strategy for an Expedient Biomimetic Route to the Bielschowskysin Skeleton.

    Science.gov (United States)

    Scesa, Paul; Wangpaichitr, Medhi; Savaraj, Niramol; West, Lyndon; Roche, Stéphane P

    2018-01-26

    Bielschowskysin (1), the flagship of the furanocembranoid diterpene family, has attracted attention from chemists owing to its intriguing and daunting polycyclic architecture and medicinal potential against lung cancer. The high level of functionalization of 1 poses a considerable challenge to synthesis. Herein, a stereoselective furan dearomatization strategy of furanocembranoids was achieved via the intermediacy of chlorohydrins. The stereochemical course of the kinetic dearomatization was established, and the C3 configuration of the resulting exo-enol ether intermediates proved to be essential to complete the late-stage transannular [2+2] photocycloaddition. Overall, this biomimetic strategy starting from the natural product acerosolide (9) featured an unprecedented regio- and highly stereoselective furan dearomatization, which provided rapid access to the pivotal exo-enol ethers en route to the intricate bielschowskyane skeleton. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Bacteriocins: exploring alternatives to antibiotics in mastitis treatment

    Directory of Open Access Journals (Sweden)

    Reneé Pieterse

    2010-10-01

    Full Text Available Mastitis is considered to be the most costly disease affecting the dairy industry. Management strategies involve the extensive use of antibiotics to treat and prevent this disease. Prophylactic dosages of antibiotics used in mastitis control programmes could select for strains with resistance to antibiotics. In addition, a strong drive towards reducing antibiotic residues in animal food products has lead to research in finding alternative antimicrobial agents. In this review we have focus on the pathogenesis of the mastitis in dairy cows, existing antibiotic treatments and possible alternative for application of bacteriocins from lactic acid bacteria in the treatment and prevention of this disease.

  9. Analysis of 27 antibiotic residues in raw cow's milk and milk-based products--validation of Delvotest® T.

    Science.gov (United States)

    Bion, Cindy; Beck Henzelin, Andrea; Qu, Yajuan; Pizzocri, Giuseppe; Bolzoni, Giuseppe; Buffoli, Elena

    2016-01-01

    Delvotest® T was evaluated for its capability at detecting residues of 27 antibiotics in raw cow's milk and in some dairy ingredients (skimmed and full-cream milk powders). The kit was used as a screening tool for the qualitative determination of antibiotics from different families in a single test. Results delivered by such a method are expressed as 'positive' or 'negative', referring to the claimed screening target concentration (STC). Validation was conducted according to the European Community Reference Laboratories' (CRLs) residues guidelines of 20 January 2010 and performed by two laboratories, one located in Europe and the other in Asia. Five criteria were evaluated including detection capability at STC, false-positive (FP) rate, false-negative (FN) rate, robustness and cross-reactivity using visual reading and Delvoscan®. STCs were set at or below the corresponding maximum residue limit (MRL), as fixed by European Regulation EC No. 37/2010. Four antibiotics (nafcillin, oxytetracycline, tetracycline and rifaximin) out of 27 had a false-negative rate ranging from 1.7% to 4.9%; however, it was still compliant with the CRLs' requirements. Globally, Delvotest T can be recommended for the analysis of the surveyed antibiotics in raw cow's milk, skimmed and full-cream milk powders. Additional compounds were tested such as sulfamethazine, spiramycin and erythromycin; however, detection at the corresponding MRL was not achievable and these compounds were removed from the validation. Other drugs from the sulfonamide, aminoglycoside or macrolide families not detected by the test at the MRL were not evaluated in this study. Regarding the reliability of this rapid test to milk-based preparations, additional experiments should be performed on a larger range of compounds and samples to validate the Delvotest T in such matrices.

  10. A QSAR approach for virtual screening of lead-like molecules en route to antitumor and antibiotic drugs from marine and microbial natural products

    Directory of Open Access Journals (Sweden)

    Florbela Pereira

    2014-05-01

    Figure 1. The unreported 15 lead antibiotic MNPs and MbNPs from AntiMarin database, using the best Rfs antibiotic model with a probability of being antibiotic greater than or equal to 0.8. Figure 2. The selected 4 lead antitumor MNPs and MbNPs from the AntiMarin database, using the best Rfs antitumor model with a probability of being antitumor greater than or equal to 0.8. The present work corroborates by one side the results of our previous work6 and enables the presentation of a new set of possible lead like bioactive compounds. Additionally, it is shown the usefulness of quantum-chemical descriptors in the discrimination of biological active and inactive compounds. The use of the εHOMO quantum-chemical descriptor in the discrimination of large scale data sets of lead-like or drug-like compounds has never been reported. This approach results in the reduction, in great extent, of the number of compounds used in real screens, and it reinforces the results of our previous work. Furthermore, besides the virtual screening, the computational methods can be very useful to build appropriate databases, allowing for effective shortcuts of NP extracts dereplication procedures, which will certainly result in increasing the efficiency of drug discovery.

  11. Antibiotics: Miracle Drugs

    Centers for Disease Control (CDC) Podcasts

    2015-04-16

    The overuse of antibiotics has led to the development of resistance among bacteria, making antibiotics ineffective in treating certain conditions. This podcast discusses the importance of talking to your healthcare professional about whether or not antibiotics will be beneficial if you’ve been diagnosed with an infectious disease.  Created: 4/16/2015 by Division of Bacterial Diseases (DBD), National Center for Immunization and Respiratory Disease (NCIRD), Get Smart: Know When Antibiotics Work Program.   Date Released: 4/16/2015.

  12. When and How to Take Antibiotics

    Science.gov (United States)

    ... antibiotic resistance? When and how to take antibiotics Antibacterial agents Bioterrorism & stockpiling antibiotics The Cost of Resistance Science of Resistance Ecology Antibiotics in Agriculture Antibacterial ...

  13. Handling Time-dependent Variables : Antibiotics and Antibiotic Resistance

    NARCIS (Netherlands)

    Munoz-Price, L. Silvia; Frencken, Jos F.; Tarima, Sergey; Bonten, Marc

    2016-01-01

    Elucidating quantitative associations between antibiotic exposure and antibiotic resistance development is important. In the absence of randomized trials, observational studies are the next best alternative to derive such estimates. Yet, as antibiotics are prescribed for varying time periods,

  14. Antibiotic use and antibiotic resistance in dental practice

    OpenAIRE

    Ytreland, Kristian J.

    2016-01-01

    Antibiotic resistance in bacteria is an increasing problem in health care settings worldwide. After approximately 70 years of antibiotic use, the bacteria have developed mechanisms that let them survive antibiotic treatment. The use of antibiotics is an important factor in resistance development. Norwegian dentists prescribe approximately 5.3% of the total antibiotics consumed in the country. Dentists tend to use mostly β-Lactam antibiotics, metronidazoles, macrolides, lincosamides and te...

  15. EDITORIAL: Ongoing climatic change in Northern Eurasia: justification for expedient research

    Science.gov (United States)

    Groisman, Pavel; Soja, Amber J.

    2009-12-01

    A brief overview of the ongoing climatic and environmental changes in Northern Eurasia serves as an editorial introduction to this, the second, special Northern Eurasia Earth Science Partnership Initiative (NEESPI) focus issue of Environmental Research Letters. Climatic changes in Northern Eurasia over the last hundred years are reflected in numerous atmospheric and terrestrial variables. Many of these are noticeably significant above the confidence level for 'weather' or other (fire regime, ecosystem change) noise and thus should be further investigated in order to adapt to their impacts. In this focus issue, we introduce assorted studies of different aspects of contemporary change in Northern Eurasia. Most of these have been presented at one of the NEESPI workshops (for more information see neespi.org) and/or American Geophysical Union and European Geosciences Union NEESPI open sessions during the past year. These studies are diverse, representing the diversity of climates and ecosystems across Northern Eurasia. Some of these are focused on smaller spatial scales and/or address only specific aspects of the global change implications across the subcontinent. But the feeling (and observational evidence) that these changes have already been quite rapid and can have global implications inspires us to bring this suite of papers to the readers' attention. See the PDF for the full text of the editorial. Focus on Climatic and Environmental Change in Northern Eurasia Contents Preface Northern Eurasia Earth Science Partnership Initiative Pavel Groisman and Amber J Soja Editorial Siberia integrated regional study: Multidisciplinary investigations of interrelation between Siberia environment dynamics and global climate change E P Gordov and E A Vaganov Studies of the energy and water cycles in Northern Eurasia Comparison and evaluation of gridded radiation products across northern Eurasia T J Troy and E F Wood Reanalysis data underestimate significant changes in growing

  16. Antibiotic resistance in bacteria

    African Journals Online (AJOL)

    antibiotic in the body and its concentration at the site of infec- tion, and the immune ... Several pathogens” are increasingly developing resistance, particularly to first-line ... and spread of antimicrobial resistance due to exposure of heavy antibiotic use in a ..... cephalosporins South Korea, Portugal, Croatia 19. France, USA ...

  17. The future of antibiotics

    Science.gov (United States)

    2014-01-01

    Antibiotic resistance continues to spread even as society is experiencing a market failure of new antibiotic research and development (R&D). Scientific, economic, and regulatory barriers all contribute to the antibiotic market failure. Scientific solutions to rekindle R&D include finding new screening strategies to identify novel antibiotic scaffolds and transforming the way we think about treating infections, such that the goal is to disarm the pathogen without killing it or modulate the host response to the organism without targeting the organism for destruction. Future economic strategies are likely to focus on ‘push’ incentives offered by public-private partnerships as well as increasing pricing by focusing development on areas of high unmet need. Such strategies can also help protect new antibiotics from overuse after marketing. Regulatory reform is needed to re-establish feasible and meaningful traditional antibiotic pathways, to create novel limited-use pathways that focus on highly resistant infections, and to harmonize regulatory standards across nations. We need new antibiotics with which to treat our patients. But we also need to protect those new antibiotics from misuse when they become available. If we want to break the cycle of resistance and change the current landscape, disruptive approaches that challenge long-standing dogma will be needed. PMID:25043962

  18. Nonmedical Uses of Antibiotics: Time to Restrict Their Use?

    Directory of Open Access Journals (Sweden)

    Richard William Meek

    2015-10-01

    Full Text Available The global crisis of antibiotic resistance has reached a point where, if action is not taken, human medicine will enter a postantibiotic world and simple injuries could once again be life threatening. New antibiotics are needed urgently, but better use of existing agents is just as important. More appropriate use of antibiotics in medicine is vital, but the extensive use of antibiotics outside medical settings is often overlooked. Antibiotics are commonly used in animal husbandry, bee-keeping, fish farming and other forms of aquaculture, ethanol production, horticulture, antifouling paints, food preservation, and domestically. This provides multiple opportunities for the selection and spread of antibiotic-resistant bacteria. Given the current crisis, it is vital that the nonmedical use of antibiotics is critically examined and that any nonessential use halted.

  19. Nonmedical Uses of Antibiotics: Time to Restrict Their Use?

    Science.gov (United States)

    Meek, Richard William; Vyas, Hrushi; Piddock, Laura Jane Violet

    2015-10-01

    The global crisis of antibiotic resistance has reached a point where, if action is not taken, human medicine will enter a postantibiotic world and simple injuries could once again be life threatening. New antibiotics are needed urgently, but better use of existing agents is just as important. More appropriate use of antibiotics in medicine is vital, but the extensive use of antibiotics outside medical settings is often overlooked. Antibiotics are commonly used in animal husbandry, bee-keeping, fish farming and other forms of aquaculture, ethanol production, horticulture, antifouling paints, food preservation, and domestically. This provides multiple opportunities for the selection and spread of antibiotic-resistant bacteria. Given the current crisis, it is vital that the nonmedical use of antibiotics is critically examined and that any nonessential use halted.

  20. Synthetic and Mechanistic Studies with Lipopeptide Antibiotics

    NARCIS (Netherlands)

    Kleijn, L.H.J.

    2018-01-01

    The cyclic lipopeptides comprise a number of clinically relevant classes of antibiotics that date back from the discovery of the polymyxins in 1947 to the recent introduction of the lipoglycopeptides. These natural products and natural product derivatives generally originate from soil-inhabiting

  1. antibiotic susceptibility pattern and multiple antibiotic resistance

    African Journals Online (AJOL)

    pg, gentamicin 10 pg, streptomycin 30 pg, erythromycin 30 ug and chloramphenicol 20 tlg. Pseudomonas aeruginosa NCTC 10662 served as control. Determination of MAR index. The MAR index was determined for each isolate by dividing the number of antibiotics to which the isolate is resistant by the total number of ...

  2. Strategies to Minimize Antibiotic Resistance

    OpenAIRE

    Sang Hee Lee; Ill Hwan Cho; Byeong Chul Jeong; Chang-Ro Lee

    2013-01-01

    Antibiotic resistance can be reduced by using antibiotics prudently based on guidelines of antimicrobial stewardship programs (ASPs) and various data such as pharmacokinetic (PK) and pharmacodynamic (PD) properties of antibiotics, diagnostic testing, antimicrobial susceptibility testing (AST), clinical response, and effects on the microbiota, as well as by new antibiotic developments. The controlled use of antibiotics in food animals is another cornerstone among efforts to reduce antibiotic r...

  3. Aerosolized antibiotics in cystic fibrosis: an update.

    Science.gov (United States)

    Fiel, Stanley B

    2014-06-01

    Inhaled antibiotic therapy, targeting Pseudomonas aeruginosa, is a fundamental component of cystic fibrosis (CF) management. Tobramycin inhalation solution (TIS) was approved in the United States (US) in 1998. Subsequent research efforts focused on developing products with a reduced treatment time burden. Aztreonam for inhalation solution (AZLI), administered via a more efficient nebulizer than TIS, was approved in the US in 2010. Dry powder for inhalation (DPI) formulations provide alternatives to nebulized therapy: tobramycin powder for inhalation (also known as TIP™) was approved in the US in 2013, and colistimethate sodium DPI received European approval in 2012. Other aerosolized antibiotics and regimens combining inhaled antibiotics are in development. Inhaled antibiotic rotation (e.g., TIS alternating with AZLI) is an important concept being actively tested in CF.

  4. Antibiotic Application and Emergence of Multiple Antibiotic Resistance (MAR) in Global Catfish Aquaculture.

    Science.gov (United States)

    Chuah, Li-Oon; Effarizah, M E; Goni, Abatcha Mustapha; Rusul, Gulam

    2016-06-01

    Catfish is one of the most cultivated species worldwide. Antibiotics are usually used in catfish farming as therapeutic and prophylactic agents. In the USA, only oxytetracycline, a combination of sulfadimethoxine and ormetoprim, and florfenicol are approved by the Food Drug Administration for specific fish species (e.g., catfish and salmonids) and their specific diseases. Misuse of antibiotics as prophylactic agents in disease prevention, however, is common and contributes in the development of antibiotic resistance. Various studies had reported on antibiotic residues and/or resistance in farmed species, feral fish, water column, sediments, and, in a lesser content, among farm workers. Ninety percent of the world aquaculture production is carried out in developing countries, which lack regulations and enforcement on the use of antibiotics. Hence, efforts are needed to promote the development and enforcement of such a regulatory structure. Alternatives to antibiotics such as antibacterial vaccines, bacteriophages and their lysins, and probiotics have been applied to curtail the increasing emergence of antibiotic-resistant bacteria due to the imprudent application of antibiotics in aquaculture.

  5. Historic perspective: prebiotics, probiotics, and other alternatives to antibiotics.

    Science.gov (United States)

    Hume, M E

    2011-11-01

    Applications of antimicrobials in food production and human health have found favor throughout human history. Antibiotic applications in agricultural and human medical arenas have resulted in tremendous increases in food animal production and historically unprecedented gains in human health protection. Successes attributed to widespread antibiotic use have been accompanied by the inadvertent emergence of antibiotic-resistant bacteria. A major problem associated with this emerging resistance is the crossover use of some antibiotics in agricultural settings as well as in the prevention and treatment of human disease. This outcome led to calls to restrict the use of human health-related antibiotics in food animal production. Calls for restricted antibiotic use have heightened existing searches for alternatives to antibiotics that give similar or enhanced production qualities as highly reliable as the antibiotics currently provided to food animals. Agricultural and scientific advances, mainly within the last 100 yr, have given us insights into sources, structures, and actions of materials that have found widespread application in our modern world. The purpose of this presentation is to provide a historic perspective on the search for what are generally known as antibiotics and alternative antimicrobials, probiotics, prebiotics, bacteriophages, bacteriocins, and phytotherapeutics.

  6. Solving the Antibiotic Crisis.

    Science.gov (United States)

    Wright, Gerard D

    2015-02-13

    Antibiotics are essential for both treating and preventing infectious diseases. Paradoxically, despite their importance as pillars of modern medicine, we are in danger of losing antibiotics because of the evolution and dissemination of resistance mechanisms throughout all pathogenic microbes. This fact, coupled with an inability to bring new drugs to market at a pace that matches resistance, has resulted in a crisis of global proportion. Solving this crisis requires the actions of many stakeholders, but chemists, chemical biologists, and microbiologists must drive the scientific innovation that is required to maintain our antibiotic arsenal. This innovation requires (1) a deep understanding of the evolution and reservoirs of resistance; (2) full knowledge of the molecular mechanisms of antibiotic action and resistance; (3) the discovery of chemical and genetic probes of antibiotic action and resistance; (4) the integration of systems biology into antibiotic discovery; and (5) the discovery of new antimicrobial chemical matter. Addressing these pressing scientific gaps will ensure that we can meet the antibiotic crisis with creativity and purpose.

  7. Economic issues and antibiotic resistance in the community.

    Science.gov (United States)

    Reed, Shelby D; Laxminarayan, Ramanan; Black, Doug J; Sullivan, Sean D

    2002-01-01

    Inappropriate antibiotic use is generally considered to be the primary cause of antibiotic resistance in the community. Multiple economic factors, at the level of physicians, patients, healthcare organizations, and pharmaceutical companies, foster poor antibiotic use. To describe the influence of economic factors on the use and development of antibiotics and to evaluate the extent to which the cost of resistance is important in the economic evaluation of antibiotic products. Literature identified through MEDLINE (1966-May 2001), bibliographies from relevant articles, government reports, and proceedings from conferences about antibiotic resistance. Economic factors at all levels of the healthcare system contribute to the inappropriate use of antibiotics in the community setting. Relatively little economic research has been published on antibiotic resistance, and very few cost-effectiveness analyses of antibiotic treatment alternatives have explicitly included the cost of resistance. A better understanding of economic factors that influence the prescribing, marketing, and development of antibiotics could lead to more successful efforts at curtailing the growth of antibiotic resistance in the community setting.

  8. Rediscovering the antibiotics of the hive.

    Science.gov (United States)

    Boukraâ, Laïd; Sulaiman, Siti A

    2009-11-01

    Honey and other bee products were subjected to laboratory and clinical investigations during the past few decades and the most remarkable discovery was their antibacterial activity. Honey has been used since ancient times for the treatment of some diseases and for the healing of wounds but its use as an anti-infective agent was superseded by modern dressings and antibiotic therapy. However, the emergence of antibiotic resistant strains of bacteria has confounded the current use of antibiotic therapy leading to the re-examination of former remedies. Honey, propolis, royal jelly and bee venom have a strong antibacterial activity. Even antibiotic-resistant strains such as epidemic strains of methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycine resistant Enterococcus (VRE) have been found to be as sensitive to honey as the antibiotic-sensitive strains of the same species. Sensitivity of bacteria to bee products varies considerably within the product and the varieties of the same product. Botanical origin plays a major role in its antibacterial activity. Propolis has been found to have the strongest action against bacteria. This is probably due to its richness in flavonoids. The most challenging problems of using hive products for medical purposes are dosage and safety. Honey and royal jelly produced as a food often are not well filtered, and may contain various particles. Processed for use in wound care, they are passed through fine filters which remove most of the pollen and other impurities to prevent allergies. Also, although honey does not allow vegetative bacteria to survive, it does contain viable spores, including clostridia. With the increased availability of licensed medical stuffs containing bee products, clinical use is expected to increase and further evidence will become available. Their use in professional care centres should be limited to those which are safe and with certified antibacterial activities. The present article is a short review

  9. The importance of antibiotic residues presence detection in milk

    Directory of Open Access Journals (Sweden)

    Dubravka Samaržija

    2002-01-01

    Full Text Available Antibiotic residues are the most present inhibitory substances in milkhaving undesirable effect on human health, technological characteristics and the quality of milk and dairy products. In order to protect consumer's health and to ensure high quality milk production, European Union (EU regulation 2377/90 sets a maximum permitted levels for antibiotic residues in milk. Although the presence of antibiotic residues in milk can be due to animal diseases treatment, and in the case of milking animals, they are mostly present after mastitis treatment. The aim of this work is to stress the importance of the continuous control on antibiotic residues presence in milk, due to the role that milk and dairy products have in human nutrition. In this paper, different groups of antibiotics, mechanisms of theirs action, mistakes occurring in dairy products manufacture as well as the methods for theirs detection are described.

  10. Alternatives to Antibiotics in Semen Extenders: A Review

    OpenAIRE

    Morrell, Jane M.; Wallgren, Margareta

    2014-01-01

    Antibiotics are added to semen extenders to be used for artificial insemination (AI) in livestock breeding to control bacterial contamination in semen arising during collection and processing. The antibiotics to be added and their concentrations for semen for international trade are specified by government directives. Since the animal production industry uses large quantities of semen for artificial insemination, large amounts of antibiotics are currently used in semen extenders. Possible alt...

  11. An alternative for antibiotic se in poultry: probiotics

    OpenAIRE

    FW Edens

    2003-01-01

    Over the past 50 years, there has been increasing amounts of antibiotics used prophylactically and as growth promoters. Today, there is a consumer and governmental outcry to eliminate that practice from poultry and livestock production. Evidence has been accumulated to show that there is a link between risk of zoonotic disease and growth promoting antibiotic usage in livestock and poultry. Therefore, alternatives to the use of growth promoting antibiotics must be found to promote growth or pr...

  12. Addressing resistance to antibiotics in systematic reviews of antibiotic interventions

    NARCIS (Netherlands)

    Leibovici, Leonard; Paul, Mical; Garner, Paul; Sinclair, David J; Afshari, Arash; Pace, Nathan Leon; Cullum, Nicky; Williams, Hywel C; Smyth, Alan; Skoetz, Nicole; Del Mar, Chris; Schilder, Anne G M; Yahav, Dafna; Tovey, David

    Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies. This

  13. Fighting antibiotic resistance in the intensive care unit using antibiotics.

    Science.gov (United States)

    Plantinga, Nienke L; Wittekamp, Bastiaan H J; van Duijn, Pleun J; Bonten, Marc J M

    2015-01-01

    Antibiotic resistance is a global and increasing problem that is not counterbalanced by the development of new therapeutic agents. The prevalence of antibiotic resistance is especially high in intensive care units with frequently reported outbreaks of multidrug-resistant organisms. In addition to classical infection prevention protocols and surveillance programs, counterintuitive interventions, such as selective decontamination with antibiotics and antibiotic rotation have been applied and investigated to control the emergence of antibiotic resistance. This review provides an overview of selective oropharyngeal and digestive tract decontamination, decolonization of methicillin-resistant Staphylococcus aureus and antibiotic rotation as strategies to modulate antibiotic resistance in the intensive care unit.

  14. The Survey for AmpC beta-lactamase Production and Characterization of Antibiotic Resistance Profile in Clinical Isolates of Klebsiella oxytoca

    Directory of Open Access Journals (Sweden)

    Mahbobeh Nassari

    2016-05-01

    beta-lactamase producing. Among examined antimicrobials, imipenem (100% and colistin (100% were most effective drugs against isolates. Respectively, 88.6%, 88.6%, 85.7% and 85.7% isolates were resistant to amikacin, cefoxitin, ciprofloxacin and cefepime. Strains showed the most frequent resistance to ceftazidime (20%. All AmpC beta-lactamase positive isolates were sensitive to amikacin, imipenem and colistin. Conclusion: Results of current study showed third-gerneration cephalosprins are not effective against 20% of infections caused by Klebsiella oxytoca. Resistance to two major classes of antibiotics (aminoglycosides and beta-lactams was seen among studied strains and treatment of infections causing by this isolates are major problem in future.

  15. Antibiotics for uncomplicated diverticulitis

    DEFF Research Database (Denmark)

    Shabanzadeh, Daniel M; Wille-Jørgensen, Peer

    2012-01-01

    Diverticulitis is an inflammatory complication to the very common condition diverticulosis. Uncomplicated diverticulitis has traditionally been treated with antibiotics with reference to the microbiology, extrapolation from trials on complicated intra-abdominal infections and clinical experience....

  16. [Antibiotics in primary care].

    Science.gov (United States)

    Steciwko, Andrzej; Lubieniecka, Małgorzata; Muszyńska, Agnieszka

    2011-05-01

    Discovered in the forties of the twentieth century antimicrobial agents have changed the world. Currently, due to their overuse, we are threatened by the increasing resistance of bacteria to antibiotics, and soon we may face a threat of inability to fight these pathogens. For that reason, the world, European and national organizations introduce antibiotics protection programs. In Poland since 2004, the National Program of Protection of Antibiotics is being held. The concept of rational antibiotic therapy is associated not only with the appropriate choice of therapy or antimicrobial dosage but also with a reduction in costs associated with a refund of medicines. Antibiotics are prescribed mostly by primary care physicians (GP), and about one fifth of visits to family doctor's office ends with prescribing antimicrobial drug. These trends are probably related to both the difficulty in applying the differential diagnosis of viral and bacterial infection in a primary care doctor's office, as well as patient's conviction about the effectiveness of antibiotic therapy in viral infections. However, although patients often want to influence the therapeutic decisions and ask their doctor for prescribing antimicrobial drug, the right conversation with a doctor alone is the critical component in satisfaction with medical care. Many countries have established standards to clarify the indications for use of antibiotics and thereby reduce their consumption. The next step is to monitor the prescribing and use of these drugs and to assess the rise of drug resistance in the area. In Poland, the recommendations regarding outpatient respiratory tract infections treatment were published and usage of antimicrobial agents monitoring has begun. However, lack of publications covering a broad analysis of antibiotic therapy and drug resistance on Polish territory is still a problem. Modem medicine has yet another tool in the fight against bacteria--they are bacteriophages. Phage therapy is

  17. FTMS structure elucidation of natural products: application to muraymycin antibiotics using ESI multi-CHEF SORI-CID FTMS(n), the top-down/bottom-up approach, and HPLC ESI capillary-skimmer CID FTMS.

    Science.gov (United States)

    McDonald, Leonard A; Barbieri, Laurel R; Carter, Guy T; Kruppa, Gary; Feng, Xidong; Lotvin, Jason A; Siegel, Marshall M

    2003-06-01

    The molecular formulas for the structures and substructures of muraymycin antibiotics A1 (C52H90N14O19, MW 1214) and B1 (C49H83N11O18, MW 1113) were determined using electrospray ionization (ESI) Fourier transform mass spectrometry (FTMS). The muraymycin A1 and B1 structures were elucidated by utilizing capillary-skimmer fragmentation with up to five stages of mass spectrometry (MS5). Multi-CHEF, a multiple ion isolation method, was used at each stage of MS(n) to isolate a parent ion and up to four reference ions, for exact-mass calibration. The parent ions were fragmented by SORI-CID and the product ions internally calibrated with average absolute mass errors less than 1 ppm at each stage in the fragmentation processes. Using the top-down/bottom-up approach, the molecular formulas for the antibiotics were determined by summing the elemental formulas of the neutral losses, obtained by measuring the mass differences (skimmer CID FTMS by correlating their fragmentation patterns with those of muraymycins A1 and B1. Sequential neutral losses of an aminosugar, a valine, a uridine, and an ester fatty acid from the muraymycin parent ions provided diagnostic fragments for characterization.

  18. Immunostimulation asa method limiting unnecessary antibiotic therapy

    Directory of Open Access Journals (Sweden)

    Agnieszka Szczukocka-Zych

    2015-12-01

    Full Text Available Recurring respiratory tract infections are typical of childhood. This results from the fact that children are exposed to pathogens, usually in groups of people, and from the immaturity of the immune system. Most upper and lower respiratory tract infections are caused by viruses. Nevertheless, antibiotics, which target bacteria, are often prescribed. Antibiotic overuse leads to increased microbial resistance to these drugs, resulting in their inefficacy. Improper treatment of respiratory infections with antibiotics ultimately leads to treatment failure. An increase in antibiotic resistance of many bacterial strains is becoming a serious global problem and makes treatment much more difficult. It is a responsibility of each physician to use antibiotics properly and implement adequate prevention of recurring respiratory tract infections. For many years, it has been attempted to find effective agents that improve immunity in children. The pharmaceutical market offers various preparations advertised as immunostimulants, such as bacterial lysates, vitamins, dietary supplements, probiotics or herbal, animal and homeopathic products. The role of immunomodulatory substances is to promote the immune system to fight pathogens, reduce the frequency of infections and decrease the demand for antibiotics. Unfortunately, most immunomodulators do not have sufficiently reliable clinical trials that would confirm their efficacy.

  19. [The history of antibiotics].

    Science.gov (United States)

    Yazdankhah, Siamak; Lassen, Jørgen; Midtvedt, Tore; Solberg, Claus Ola

    2013-12-10

    The development of chemical compounds for the treatment of infectious diseases may be divided into three phases: a) the discovery in the 1600s in South America of alkaloid extracts from the bark of the cinchona tree and from the dried root of the ipecacuanha bush, which proved effective against, respectively, malaria (quinine) and amoebic dysentery (emetine); b) the development of synthetic drugs, which mostly took place in Germany, starting with Paul Ehrlich's (1854-1915) discovery of salvarsan (1909), and crowned with Gerhard Domagk's (1895-1964) discovery of the sulfonamides (1930s); and c) the discovery of antibiotics. The prime example of the latter is the development of penicillin in the late 1920s following a discovery by a solitary research scientist who never worked in a team and never as part of a research programme. It took another ten years or so before drug-quality penicillin was produced, with research now dependent on being conducted in large collaborative teams, frequently between universities and wealthy industrial companies. The search for new antibiotics began in earnest in the latter half of the 1940s and was mostly based on soil microorganisms. Many new antibiotics were discovered in this period, which may be termed «the golden age of antibiotics». Over the past three decades, the development of new antibiotics has largely stalled, while antibiotic resistance has increased. This situation may require new strategies for the treatment of infectious diseases.

  20. Strategies to Minimize Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Sang Hee Lee

    2013-09-01

    Full Text Available Antibiotic resistance can be reduced by using antibiotics prudently based on guidelines of antimicrobial stewardship programs (ASPs and various data such as pharmacokinetic (PK and pharmacodynamic (PD properties of antibiotics, diagnostic testing, antimicrobial susceptibility testing (AST, clinical response, and effects on the microbiota, as well as by new antibiotic developments. The controlled use of antibiotics in food animals is another cornerstone among efforts to reduce antibiotic resistance. All major resistance-control strategies recommend education for patients, children (e.g., through schools and day care, the public, and relevant healthcare professionals (e.g., primary-care physicians, pharmacists, and medical students regarding unique features of bacterial infections and antibiotics, prudent antibiotic prescribing as a positive construct, and personal hygiene (e.g., handwashing. The problem of antibiotic resistance can be minimized only by concerted efforts of all members of society for ensuring the continued efficiency of antibiotics.

  1. Strategies to minimize antibiotic resistance.

    Science.gov (United States)

    Lee, Chang-Ro; Cho, Ill Hwan; Jeong, Byeong Chul; Lee, Sang Hee

    2013-09-12

    Antibiotic resistance can be reduced by using antibiotics prudently based on guidelines of antimicrobial stewardship programs (ASPs) and various data such as pharmacokinetic (PK) and pharmacodynamic (PD) properties of antibiotics, diagnostic testing, antimicrobial susceptibility testing (AST), clinical response, and effects on the microbiota, as well as by new antibiotic developments. The controlled use of antibiotics in food animals is another cornerstone among efforts to reduce antibiotic resistance. All major resistance-control strategies recommend education for patients, children (e.g., through schools and day care), the public, and relevant healthcare professionals (e.g., primary-care physicians, pharmacists, and medical students) regarding unique features of bacterial infections and antibiotics, prudent antibiotic prescribing as a positive construct, and personal hygiene (e.g., handwashing). The problem of antibiotic resistance can be minimized only by concerted efforts of all members of society for ensuring the continued efficiency of antibiotics.

  2. Death Becomes Them: Bacterial Community Dynamics and Stilbene Antibiotic Production in Cadavers of Galleria mellonella Killed by Heterorhabditis and Photorhabdus spp.

    Science.gov (United States)

    Wollenberg, Amanda C; Jagdish, Tanush; Slough, Greg; Hoinville, Megan E; Wollenberg, Michael S

    2016-10-01

    Insect larvae killed by entomopathogenic nematodes are thought to contain bacterial communities dominated by a single bacterial genus, that of the nematode's bacterial symbiont. In this study, we used next-generation sequencing to profile bacterial community dynamics in greater wax moth (Galleria mellonella) larvae cadavers killed by Heterorhabditis nematodes and their Photorhabdus symbionts. We found that, although Photorhabdus strains did initially displace an Enterococcus-dominated community present in uninfected G. mellonella insect larvae, the cadaver community was not static. Twelve days postinfection, Photorhabdus shared the cadaver with Stenotrophomonas species. Consistent with this result, Stenotrophomonas strains isolated from infected cadavers were resistant to Photorhabdus-mediated toxicity in solid coculture assays. We isolated and characterized a Photorhabdus-produced antibiotic from G. mellonella cadavers, produced it synthetically, and demonstrated that both the natural and synthetic compounds decreased G. mellonella-associated Enterococcus growth, but not Stenotrophomonas growth, in vitro Finally, we showed that the Stenotrophomonas strains described here negatively affected Photorhabdus growth in vitro Our results add an important dimension to a broader understanding of Heterorhabditis-Photorhabdus biology and also demonstrate that interspecific bacterial competition likely characterizes even a theoretically monoxenic environment, such as a Heterorhabditis-Photorhabdus-parasitized insect cadaver. Understanding, and eventually manipulating, both human and environmental health depends on a complete accounting of the forces that act on and shape microbial communities. One of these underlying forces is hypothesized to be resource competition. A resource that has received little attention in the general microbiological literature, but likely has ecological and evolutionary importance, is dead/decaying multicellular organisms. Metazoan cadavers

  3. Composting swine slurry to reduce indicators and antibiotic resistance genes

    Science.gov (United States)

    Over the last twenty years there have been considerable increases in the incidence of human infections with bacteria that are resistant to commonly used antibiotics. This has precipitated concerns about the use of antibiotics in livestock production. Composting of swine manure has several advantages...

  4. Antibiotic Resistance and Antibiotic Resistance Genes in Escherichia coli Isolates from Hospital Wastewater in Vietnam.

    Science.gov (United States)

    Lien, La Thi Quynh; Lan, Pham Thi; Chuc, Nguyen Thi Kim; Hoa, Nguyen Quynh; Nhung, Pham Hong; Thoa, Nguyen Thi Minh; Diwan, Vishal; Tamhankar, Ashok J; Stålsby Lundborg, Cecilia

    2017-06-29

    The environmental spread of antibiotic-resistant bacteria has been recognised as a growing public health threat for which hospitals play a significant role. The aims of this study were to investigate the prevalence of antibiotic resistance and antibiotic resistance genes (ARGs) in Escherichia coli isolates from hospital wastewater in Vietnam. Wastewater samples before and after treatment were collected using continuous sampling every month over a year. Standard disk diffusion and E-test were used for antibiotic susceptibility testing. Extended-spectrum beta-lactamase (ESBL) production was tested using combined disk diffusion. ARGs were detected by polymerase chain reactions. Resistance to at least one antibiotic was detected in 83% of isolates; multidrug resistance was found in 32%. The highest resistance prevalence was found for co-trimoxazole (70%) and the lowest for imipenem (1%). Forty-three percent of isolates were ESBL-producing, with the bla TEM gene being more common than bla CTX-M . Co-harbouring of the bla CTX-M , bla TEM and qepA genes was found in 46% of isolates resistant to ciprofloxacin. The large presence of antibiotic-resistant E. coli isolates combined with ARGs in hospital wastewater, even post-treatment, poses a threat to public health. It highlights the need to develop effective processes for hospital wastewater treatment plants to eliminate antibiotic resistant bacteria and ARGs.

  5. Antibiotics may act as growth/obesity promoters in humans as an inadvertent result of antibiotic pollution?

    Science.gov (United States)

    Ternak, Gabor

    2005-01-01

    The growth promoting effects of antibiotics were first discovered in the 1940s. Since then, many antimicrobials have been found to improve average daily weight gain and feed efficiency. The total production of antibiotics can be estimated between 100,000-200,000 tons annually and the human population is being influenced, directly or indirectly (from the environment) by this amount of drug. The twentieth-century increase in human height and the obesity of the population is roughly observed since the mass consumption of antibiotics 40-50 years ago. The association between antibiotic consumption and the increase of human growth/obesity is suspected.

  6. A QSAR approach for virtual screening of lead-like molecules en route to antitumor and antibiotic drugs from marine and microbial natural products

    OpenAIRE

    Florbela Pereira; Diogo A. R. S. Latino

    2014-01-01

    Natural products (NPs), or synthetic products inspired by NPs, have been the single most productive source of leads for drug development. In fact, more than half of the approved drugs from 1981 to 2010 were based on NPs.1 At the turn of the 21st century, a new branch of NPs chemistry was fully established – Marine Natural Products (MNPs). The future seems very promising for this new NP subfield, since MNPs chemists have already elucidated the chemical structure of over 22,000 novel compounds....

  7. The Antibiotic Resistant Target Seeker (ARTS), an exploration engine for antibiotic cluster prioritization and novel drug target discovery

    DEFF Research Database (Denmark)

    Alanjary, Mohammad; Kronmiller, Brent; Adamek, Martina

    2017-01-01

    With the rise of multi-drug resistant pathogens and the decline in number of potential new antibiotics in development there is a fervent need to reinvigorate the natural products discovery pipeline. Most antibiotics are derived from secondary metabolites produced by microorganisms and plants....... To avoid suicide, an antibiotic producer harbors resistance genes often found within the same biosynthetic gene cluster (BGC) responsible for manufacturing the antibiotic. Existing mining tools are excellent at detecting BGCs or resistant genes in general, but provide little help in prioritizing...... and identifying gene clusters for compounds active against specific and novel targets. Here we introduce the 'Antibiotic Resistant Target Seeker' (ARTS) available at https://arts.ziemertlab.com. ARTS allows for specific and efficient genome mining for antibiotics with interesting and novel targets. The aim...

  8. Towards new β-lactam antibiotics

    NARCIS (Netherlands)

    Andersson, I.; Terwisscha van Scheltinga, A.C.; Valegård, K.

    2001-01-01

    Antibiotics have had a profound impact on human health and belong to one of the largest-selling classes of drugs worldwide. Introduced into industrial production only some half century ago, these miracle drugs have been the main contributors to the recent increase in human life expectancy. However,

  9. Enabling techniques in the search for new antibiotics: Combinatorial biosynthesis of sugar-containing antibiotics.

    Science.gov (United States)

    Park, Je Won; Nam, Sang-Jip; Yoon, Yeo Joon

    2017-06-15

    Nature has a talent for inventing a vast number of natural products, including hybrids generated by blending different scaffolds, resulting in a myriad of bioactive chemical entities. Herein, we review the highlights and recent trends (2010-2016) in the combinatorial biosynthesis of sugar-containing antibiotics where nature's structural diversification capabilities are exploited to enable the creation of new anti-infective and anti-proliferative drugs. In this review, we describe the modern combinatorial biosynthetic approaches for polyketide synthase-derived complex and aromatic polyketides, non-ribosomal peptide synthetase-directed lipo-/glycopeptides, aminoglycosides, nucleoside antibiotics, and alkaloids, along with their therapeutic potential. Finally, we present the feasible nexus between combinatorial biosynthesis, systems biology, and synthetic biology as a toolbox to provide new antibiotics that will be indispensable in the post-antibiotic era. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. 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.

  11. Lysobacter species: a potential source of novel antibiotics.

    Science.gov (United States)

    Panthee, Suresh; Hamamoto, Hiroshi; Paudel, Atmika; Sekimizu, Kazuhisa

    2016-11-01

    Infectious diseases threaten global health due to the ability of microbes to acquire resistance against clinically used antibiotics. Continuous discovery of antibiotics with a novel mode of action is thus required. Actinomycetes and fungi are currently the major sources of antibiotics, but the decreasing rate of discovery of novel antibiotics suggests that the focus should be changed to previously untapped groups of microbes. Lysobacter species have a genome size of ~6 Mb with a relatively high G + C content of 61-70 % and are characterized by their ability to produce peptides that damage the cell walls or membranes of other microbes. Genome sequence analysis revealed that each Lysobacter species has gene clusters for the production of 12-16 secondary metabolites, most of which are peptides, thus making them 'peptide production specialists'. Given that the number of antibiotics isolated is much lower than the number of gene clusters harbored, further intensive studies of Lysobacter are likely to unearth novel antibiotics with profound biomedical applications. In this review, we summarize the structural diversity, activity and biosynthesis of lysobacterial antibiotics and highlight the importance of Lysobacter species for antibiotic production.

  12. Environmental adaptation and vertical dissemination of ESBL-/pAmpC-producing Escherichia coli in an integrated broiler production chain in the absence of an antibiotic treatment.

    Science.gov (United States)

    Projahn, Michaela; Daehre, Katrin; Semmler, Torsten; Guenther, Sebastian; Roesler, Uwe; Friese, Anika

    2018-01-17

    High prevalence numbers of extended-spectrum beta-lactamase- (ESBL-)/plasmid-mediated AmpC beta-lactamase- (pAmpC-) producing Escherichia coli in broiler chicken and their distribution along the broiler production chain is an ongoing problem in food production. We, therefore, investigated resistant isolates along the broiler production chain to determine whether there is a constantly occurring direct vertical transmission of the ESBL-/pAmpC-producing E. coli from the parent flocks to their offspring or not. We, furthermore, analysed the isolates concerning the occurrence of virulence factors and their ability to form biofilms to estimate their potential to effectively colonize broiler chickens and/or persist and survive in the environment of the broiler production facilities. Using whole genome sequencing, we could show that ESBL-/pAmpC-producing E. coli were likely transferred in a step-wise process along the broiler production chain but not directly from the parent flock to the fattening flock with every single batch of offspring chickens. Additionally, resistant E. coli strains showing an extraintestinal pathogenic genotype as well as high numbers of virulence-associated genes including the production of curli fibres and cellulose have high capabilities to persist and spread in the broiler production chain. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  13. Sub-lethal antibiotic treatment leads to multidrug resistance via radical-induced mutagenesis

    Science.gov (United States)

    Kohanski, Michael A.; DePristo, Mark A.; Collins, James J.

    2010-01-01

    Summary Antibiotic resistance arises through mechanisms such as selection of naturally occurring resistant mutants and horizontal gene transfer. Recently, oxidative stress has been implicated as one of the mechanisms whereby bactericidal antibiotics kill bacteria. Here we show that sub-lethal levels of bactericidal antibiotics induce mutagenesis, resulting in heterogeneous increases in the minimum inhibitory concentration for a range of antibiotics, irrespective of the drug target. This increase in mutagenesis correlates with an increase in ROS, and is prevented by the ROS scavenger thiourea and by anaerobic conditions, indicating that sub-lethal concentrations of antibiotics induce mutagenesis by stimulating the production of ROS. We demonstrate that these effects can lead to mutant strains that are sensitive to the applied antibiotic but resistant to other antibiotics. This work establishes a radical-based molecular mechanism whereby sub-lethal levels of antibiotics can lead to multidrug resistance, which has important implications for the widespread use and misuse of antibiotics. PMID:20159551

  14. Actinomycetes: still a source of novel antibiotics.

    Science.gov (United States)

    Genilloud, Olga

    2017-10-18

    Covering: 2006 to 2017Actinomycetes have been, for decades, one of the most important sources for the discovery of new antibiotics with an important number of drugs and analogs successfully introduced in the market and still used today in clinical practice. The intensive antibacterial discovery effort that generated the large number of highly potent broad-spectrum antibiotics, has seen a dramatic decline in the large pharma industry in the last two decades resulting in a lack of new classes of antibiotics with novel mechanisms of action reaching the clinic. Whereas the decline in the number of new chemical scaffolds and the rediscovery problem of old known molecules has become a hurdle for industrial natural products discovery programs, new actinomycetes compounds and leads have continued to be discovered and developed to the preclinical stages. Actinomycetes are still one of the most important sources of chemical diversity and a reservoir to mine for novel structures that is requiring the integration of diverse disciplines. These can range from novel strategies to isolate species previously not cultivated, innovative whole cell screening approaches and on-site analytical detection and dereplication tools for novel compounds, to in silico biosynthetic predictions from whole gene sequences and novel engineered heterologous expression, that have inspired the isolation of new NPs and shown their potential application in the discovery of novel antibiotics. This review will address the discovery of antibiotics from actinomycetes from two different perspectives including: (1) an update of the most important antibiotics that have only reached the clinical development in the recent years despite their early discovery, and (2) an overview of the most recent classes of antibiotics described from 2006 to 2017 in the framework of the different strategies employed to untap novel compounds previously overlooked with traditional approaches.

  15. Opportunities for synthetic biology in antibiotics: expanding glycopeptide chemical diversity.

    Science.gov (United States)

    Thaker, Maulik N; Wright, Gerard D

    2015-03-20

    Synthetic biology offers a new path for the exploitation and improvement of natural products to address the growing crisis in antibiotic resistance. All antibiotics in clinical use are facing eventual obsolesce as a result of the evolution and dissemination of resistance mechanisms, yet there are few new drug leads forthcoming from the pharmaceutical sector. Natural products of microbial origin have proven over the past 70 years to be the wellspring of antimicrobial drugs. Harnessing synthetic biology thinking and strategies can provide new molecules and expand chemical diversity of known antibiotic scaffolds to provide much needed new drug leads. The glycopeptide antibiotics offer paradigmatic scaffolds suitable for such an approach. We review these strategies here using the glycopeptides as an example and demonstrate how synthetic biology can expand antibiotic chemical diversity to help address the growing resistance crisis.

  16. ANTIBIOTIC-ASSOCIATED DIARRHEA AND ANTIBIOTIC-ASSOCIATED COLITIS

    Directory of Open Access Journals (Sweden)

    E. A. Belousova

    2014-01-01

    Full Text Available The article presents most recent data on antibiotic-associated intestinal disorders. The author reviews epidemiology and causative microorganisms in antibiotic-induced diarrhea and pseudomembranous colitis as well as clinical variants of antibiotic-associated disorders. Diagnosis methods are decribed at length with special attention to most sensitive and informative tests. Treatment of different clinical variants of antibiotic-induced disorders is discussed in detail.

  17. Antibiotics: Responding to a Global Challenge

    Directory of Open Access Journals (Sweden)

    Christopher C. Butler

    2012-06-01

    Full Text Available The miracle of antibiotics is hard to exaggerate. Each day, in every corner of the world, antibiotics improve, or could be improving outcomes in the septic neonate, the child with pneumonia, the new mother after a complicated delivery, the patient undergoing surgery, the nursing home resident with a urinary tract infection, the patient being treated of cancer, or the trauma patient on life support. The miracle also keeps our animals healthy for effective food production. But the miracle of these ‘wonder drugs’ is under threat and may be short lived: antimicrobial resistance is relentlessly increasing, especially for Gram negative organisms, prompting the oft expressed concern that we are plummeting head-long back into the pre-antibiotics era where clinicians and families once again will have to stand by and watch patients and loved ones die from once easily-treated infections. [...

  18. Properties of immobilised penicillin G Acylase in beta-lactam antibiotic synthesis

    NARCIS (Netherlands)

    Janssen, M.H.A.

    2006-01-01

    The beta-lactam antibiotics are the most important class of antibiotics used today. In the last decade the production routes of these antibiotics have shifted from chemical routes to more environmentally benign routes using the enzyme penicillin G acylase. For both practical and economical reasons

  19. Improving antibiotic use in daily hospital practice : The antibiotic checklist

    NARCIS (Netherlands)

    van Daalen, F.V.

    2018-01-01

    Better use of current antibiotic agents is necessary to help control antimicrobial resistance (AMR). Antibiotic stewardship programs (ASPs) are introduced to coordinate activities to measure and improve appropriate antibiotic use in daily hospital practice. This thesis shows how the introduction of

  20. Resistance-resistant antibiotics.

    Science.gov (United States)

    Oldfield, Eric; Feng, Xinxin

    2014-12-01

    New antibiotics are needed because drug resistance is increasing while the introduction of new antibiotics is decreasing. We discuss here six possible approaches to develop 'resistance-resistant' antibiotics. First, multitarget inhibitors in which a single compound inhibits more than one target may be easier to develop than conventional combination therapies with two new drugs. Second, inhibiting multiple targets in the same metabolic pathway is expected to be an effective strategy owing to synergy. Third, discovering multiple-target inhibitors should be possible by using sequential virtual screening. Fourth, repurposing existing drugs can lead to combinations of multitarget therapeutics. Fifth, targets need not be proteins. Sixth, inhibiting virulence factor formation and boosting innate immunity may also lead to decreased susceptibility to resistance. Although it is not possible to eliminate resistance, the approaches reviewed here offer several possibilities for reducing the effects of mutations and, in some cases, suggest that sensitivity to existing antibiotics may be restored in otherwise drug-resistant organisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Antibiotic resistance in Salmonella

    NARCIS (Netherlands)

    Vo, A.T.T.

    2007-01-01

    Immediately after their introduction in the beginning of the fourties of the previous century, the agents used to combat infectious diseases caused by bacteria were regarded with suspicion, but not long thereafter antibiotics had the status of miracle drugs. For decades mankind has lived under the

  2. Antibiotics in laboratory medicine

    National Research Council Canada - National Science Library

    Lorian, Victor

    2005-01-01

    ... in critical articles and reviews. Materials appearing in this book prepared by individuals as part of their official duties as U.S. government employees are not covered by the above-mentioned copyright. Printed in the USA Library of Congress Cataloging-in-Publication Data Antibiotics in laboratory medicine / [edited by] Victor Lorian. - 5th ed...

  3. Antibiotic resistance reservoirs

    NARCIS (Netherlands)

    Versluis, Dennis

    2016-01-01

    One of the major threats to human health in the 21st century is the emergence of pathogenic bacteria that are resistant to multiple antibiotics, thereby limiting treatment options. An important route through which pathogens become resistant is via acquisition of resistance genes from environmental

  4. Mechanisms of Antibiotic Resistance

    Science.gov (United States)

    Munita, Jose M.; Arias, Cesar A.

    2015-01-01

    Emergence of resistance among the most important bacterial pathogens is recognized as a major public health threat affecting humans worldwide. Multidrug-resistant organisms have emerged not only in the hospital environment but are now often identified in community settings, suggesting that reservoirs of antibiotic-resistant bacteria are present outside the hospital. The bacterial response to the antibiotic “attack” is the prime example of bacterial adaptation and the pinnacle of evolution. “Survival of the fittest” is a consequence of an immense genetic plasticity of bacterial pathogens that trigger specific responses that result in mutational adaptations, acquisition of genetic material or alteration of gene expression producing resistance to virtually all antibiotics currently available in clinical practice. Therefore, understanding the biochemical and genetic basis of resistance is of paramount importance to design strategies to curtail the emergence and spread of resistance and devise innovative therapeutic approaches against multidrug-resistant organisms. In this chapter, we will describe in detail the major mechanisms of antibiotic resistance encountered in clinical practice providing specific examples in relevant bacterial pathogens. PMID:27227291

  5. Bacterial cheating limits antibiotic resistance

    Science.gov (United States)

    Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff

    2012-02-01

    The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.

  6. Mission Critical: Preventing Antibiotic Resistance

    Science.gov (United States)

    ... this? Submit Button Past Emails Mission Critical: Preventing Antibiotic Resistance Recommend on Facebook Tweet Share Compartir Can you ... spp. So, what can we do to prevent antibiotic resistance in healthcare settings? Patients, healthcare providers, healthcare facility ...

  7. Type II thioesterase gene (ECO-orf27) from Amycolatopsis orientalis influences production of the polyketide antibiotic, ECO-0501 (LW01).

    Science.gov (United States)

    Shen, Yang; Huang, He; Zhu, Li; Luo, Minyu; Chen, Daijie

    2012-11-01

    ECO-orf27 associated with the cluster of ECO-0501 (LW01) from Amycolatopsis orientalis is deduced to encode a type II thioesterase. Disruption of ECO-orf27 reduced LW01 production by 95 %. Complementation of the disrupted mutant with intact ECO-orf27 restored the production of LW01 suggesting that ECO-orf27 is crucial for LW01 biosynthesis. ECO-TE I, the gene encoding type I thioesterase from LW01 polyketide synthases, cannot complement ECO-orf27 deficient mutant distinguishing ECO-orf27 from type I thioesterase gene. Type II thioesterase gene pikAV from Streptomyces venezuelae could complement ECO-orf27 in A. orientalis indicating that the two genes are equivalent in their function. Overexpression of ECO-orf27 resulted in a 20 % increase in LW01 production providing an alternative approach for yield improvement.

  8. Initial efforts toward the optimization of arylomycins for antibiotic activity.

    Science.gov (United States)

    Roberts, Tucker C; Schallenberger, Mark A; Liu, Jian; Smith, Peter A; Romesberg, Floyd E

    2011-07-28

    While most clinically used antibiotics were derived from natural products, the isolation of new broad-spectrum natural products has become increasingly rare and narrow-spectrum agents are typically deemed unsuitable for development because of intrinsic limitations of their scaffold or target. However, it is possible that the spectrum of a natural product antibiotic might be limited by specific resistance mechanisms in some bacteria, such as target mutations, and the spectra of such "latent" antibiotics might be reoptimized by derivatization, just as has been done with clinically deployed antibiotics. We recently showed that the spectrum of the arylomycin natural product antibiotics, which act via the novel mechanism of inhibiting type I signal peptidase, is broader than previously believed and that resistance in several key human pathogens is due to the presence of a specific Pro residue in the target peptidase that disrupts interactions with the lipopeptide tail of the antibiotic. To begin to test whether this natural resistance might be overcome by derivatization, we synthesized analogues with altered lipopeptide tails and identified several with an increased spectrum of activity against S. aureus. The data support the hypothesis that the arylomycins are latent antibiotics, suggest that their spectrum may be optimized by derivatization, and identify a promising scaffold upon which future optimization efforts might focus.

  9. Natural and engineered biosynthesis of nucleoside antibiotics in Actinomycetes.

    Science.gov (United States)

    Chen, Wenqing; Qi, Jianzhao; Wu, Pan; Wan, Dan; Liu, Jin; Feng, Xuan; Deng, Zixin

    2016-03-01

    Nucleoside antibiotics constitute an important family of microbial natural products bearing diverse bioactivities and unusual structural features. Their biosynthetic logics are unique with involvement of complex multi-enzymatic reactions leading to the intricate molecules from simple building blocks. Understanding how nature builds this family of antibiotics in post-genomic era sets the stage for rational enhancement of their production, and also paves the way for targeted persuasion of the cell factories to make artificial designer nucleoside drugs and leads via synthetic biology approaches. In this review, we discuss the recent progress and perspectives on the natural and engineered biosynthesis of nucleoside antibiotics.

  10. Restricted use of antibiotics in organic pig farming

    DEFF Research Database (Denmark)

    Aabo, Søren; Jensen, Annette Nygaard

    2013-01-01

    Can the restricted use of antibiotics in organic pig farming be documented to provide a safer, high quality meat product with less antibiotic resistant bacteria? The project SafeOrganic aims to document that the restricted use of antimicrobials in organic pig production leads to lower levels...... of antibiotic resistant bacteria compared with the level in conventional pigs. However, the project will also address the risk of losing this quality parameter, due to a widespread practice of slaughtering organic pigs together with conventional pigs, implying a risk of cross-contamination....

  11. Off-label abuse of antibiotics by bacteria.

    Science.gov (United States)

    Viswanathan, V K

    2014-01-01

    Antibiotics and antibiotic resistance made news on several fronts in the past year. Many public health organizations, including the CDC, used terms such as "crisis", "catastrophic consequences", and "nightmare scenario" to highlight the rapid emergence and spread of antibiotic resistance. A report from the Pew Commission on Industrial Farm Animal Production, on the fifth anniversary of the publication of its landmark 2008 report, noted that state and federal legislative efforts to limit non-therapeutic use of antibiotics in animal production were thwarted by drug and food animal industries. In its lobbying disclosures, the Farm Bureau stated that such efforts to limit use of animal antibiotics were "based on emotion and no credible peer reviewed science." Meanwhile, there have been inexorable advances in our understanding of the molecular mechanisms by which antibiotics induce diversity and resistance in bacteria. This article reviews one study that probed the role of the bacterial general stress response in sub-inhibitory antibiotic-induced mutagenesis and antibiotic resistance.

  12. Bio-based production of fuels and industrial chemicals by repurposing antibiotic-producing type I modular polyketide synthases: opportunities and challenges

    DEFF Research Database (Denmark)

    Yuzawa, Satoshi; Keasling, Jay D.; Katz, Leonard

    2017-01-01

    Complex polyketides comprise a large number of natural products that have broad application in medicine and agriculture. They are produced in bacteria and fungi from large enzyme complexes named type I modular polyketide synthases (PKSs) that are composed of multifunctional polypeptides containin...... have applications as fuels or industrial chemicals....

  13. An expedient reverse-phase high-performance chromatography (RP-HPLC) based method for high-throughput analysis of deferoxamine and ferrioxamine in urine.

    Science.gov (United States)

    Arshad, Bushra; Iqbal, Tahira; Akram, Sumia; Mushtaq, Muhammad

    2017-02-01

    The present study was planned to optimize and validate an expedient reverse-phase high chromatography (RP-HPLC) based protocol for the analysis of deferoxamine (DFO) and ferrioxamine (FO) in urinary execration of patients suffering β-thalassemia major. The optimized RP-HPLC method was found to be linear over the wide range of DFO and FO concentration (1-90 μg/mL) with appreciable recovery rates (79.64-97.30%) of quality controls at improved detection and quantitation limits and acceptable inter and intraday variability. Real-time analysis of DFO and FO in the urine of thalassemic patients (male and female) at different intervals of Desferal®(Novartis Pharmaceuticals Corporation) injection revealed DFO and FO excretion at significantly (p < 0) different rates. The maximum concentrations of DFO (76.7 ± 3.06 μg/mL) and FO (74.2 ± 3.25 μg/mL) were found in urine samples, collected after 6 h of drug infusion while the minimum levels of DFO (1.10 ± 0.12 μg/mL) and FO (2.97 ± 0.13 μg/mL) were excreted by patients after 24 h. The present paper offers balanced conditions for an expedient, reliable and quick determination of DFO and FO in urine samples. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Addressing resistance to antibiotics in systematic reviews of antibiotic interventions

    DEFF Research Database (Denmark)

    Leibovici, Leonard; Paul, Mical; Garner, Paul

    2016-01-01

    Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies....... This omission creates a skewed view, which emphasizes short-term efficacy and ignores the long-term consequences to the patient and other people. We offer a framework for addressing antibiotic resistance in systematic reviews. We suggest that the data on background resistance in the original trials should...... controlled trials or systematic reviews....

  15. Environmental pollution by antibiotics and by antibiotic resistance determinants

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Jose Luis, E-mail: jlmtnez@cnb.csic.e [Departamento de Biotecnologia Microbiana, Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Darwin 3, Cantoblanco, 28049 Madrid, and CIBERESP (Spain)

    2009-11-15

    Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.

  16. Handling Time-dependent Variables: Antibiotics and Antibiotic Resistance.

    Science.gov (United States)

    Munoz-Price, L Silvia; Frencken, Jos F; Tarima, Sergey; Bonten, Marc

    2016-06-15

    Elucidating quantitative associations between antibiotic exposure and antibiotic resistance development is important. In the absence of randomized trials, observational studies are the next best alternative to derive such estimates. Yet, as antibiotics are prescribed for varying time periods, antibiotics constitute time-dependent exposures. Cox regression models are suited for determining such associations. After explaining the concepts of hazard, hazard ratio, and proportional hazards, the effects of treating antibiotic exposure as fixed or time-dependent variables are illustrated and discussed. Wider acceptance of these techniques will improve quantification of the effects of antibiotics on antibiotic resistance development and provide better evidence for guideline recommendations. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  17. Methodological aspects of accounting production cost of public sector entities

    Directory of Open Access Journals (Sweden)

    Людмила Геннадіївна Ловінська

    2015-09-01

    Full Text Available The necessity of obtaining objective information about the activities of the public sector in various areas of the production is defined. It is proved an expediency of development the Project of «Guidelines for the structure of production costs» on the basis of the approved in the public sector NP(SAPS 135 "Costs". The need for accounting costs by type of activity (operational, financial and investment is marked. The composition of production costs is defined

  18. Bio-based production of fuels and industrial chemicals by repurposing antibiotic-producing type I modular polyketide synthases: opportunities and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Yuzawa, Satoshi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Biological Systems and Engineering Division; Keasling, Jay D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Biological Systems and Engineering Division; Univ. of California, Berkeley, CA (United States). QB3 Inst.; Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States). Dept. of Bioengineering; Univ. of California, Berkeley, CA (United States). Dept. of Chemical and Biomolecular Engineering; Technical Univ. of Denmark, Horsholm (Denmark). Novo Nordisk Foundation Center for Biosustainability; Katz, Leonard [Univ. of California, Berkeley, CA (United States). QB3 Inst.

    2016-11-16

    Complex polyketides comprise a large number of natural products that have broad application in medicine and agriculture. They are produced in bacteria and fungi from large enzyme complexes named type I modular polyketide synthases (PKSs) that are composed of multifunctional polypeptides containing discrete enzymatic domains organized into modules. The modular nature of PKSs has enabled a multitude of efforts to engineer the PKS genes to produce novel polyketides of predicted structure. Finally, we have repurposed PKSs to produce a number of short-chain mono- and di-carboxylic acids and ketones that could have applications as fuels or industrial chemicals.

  19. Bio-based production of fuels and industrial chemicals by repurposing antibiotic-producing type I modular polyketide synthases: opportunities and challenges.

    Science.gov (United States)

    Yuzawa, Satoshi; Keasling, Jay D; Katz, Leonard

    2017-04-01

    Complex polyketides comprise a large number of natural products that have broad application in medicine and agriculture. They are produced in bacteria and fungi from large enzyme complexes named type I modular polyketide synthases (PKSs) that are composed of multifunctional polypeptides containing discrete enzymatic domains organized into modules. The modular nature of PKSs has enabled a multitude of efforts to engineer the PKS genes to produce novel polyketides of predicted structure. We have repurposed PKSs to produce a number of short-chain mono- and di-carboxylic acids and ketones that could have applications as fuels or industrial chemicals.

  20. Antibiotic use and microbiome function.

    Science.gov (United States)

    Ferrer, Manuel; Méndez-García, Celia; Rojo, David; Barbas, Coral; Moya, Andrés

    2017-06-15

    Our microbiome should be understood as one of the most complex components of the human body. The use of β-lactam antibiotics is one of the microbiome covariates that influence its composition. The extent to which our microbiota changes after an antibiotic intervention depends not only on the chemical nature of the antibiotic or cocktail of antibiotics used to treat specific infections, but also on the type of administration, duration and dose, as well as the level of resistance that each microbiota develops. We have begun to appreciate that not all bacteria within our microbiota are vulnerable or reactive to different antibiotic interventions, and that their influence on both microbial composition and metabolism may differ. Antibiotics are being used worldwide on a huge scale and the prescription of antibiotics is continuing to rise; however, their effects on our microbiota have been reported for only a limited number of them. This article presents a critical review of the antibiotics or antibiotic cocktails whose use in humans has been linked to changes in the composition of our microbial communities, with a particular focus on the gut, oral, respiratory, skin and vaginal microbiota, and on their molecular agents (genes, proteins and metabolites). We review the state of the art as of June 2016, and cover a total of circa 68 different antibiotics. The data herein are the first to compile information about the bacteria, fungi, archaea and viruses most influenced by the main antibiotic treatments prescribed nowadays. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Gut Microbiome and Antibiotics.

    Science.gov (United States)

    Iizumi, Tadasu; Battaglia, Thomas; Ruiz, Victoria; Perez Perez, Guillermo I

    2017-12-05

    Despite that the human gastrointestinal tract is the most populated ecological niche by bacteria in the human body, much is still unknown about its characteristics. This site is highly susceptible to the effects of many external factors that may affect in the quality and the quantity of the microbiome. Specific factors such as diet, personal hygiene, pharmacological drugs and the use of antibiotics can produce a significant impact on the gut microbiota. The effect of these factors is more relevant early in life, when the gut microbiota has not yet fully established. In this review, we discussed the effect of type and doses of the antibiotics on the gut microbiota and what the major consequences in the use and abuse of these antimicrobial agents. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  2. Alternatives to Antibiotics in Semen Extenders: A Review

    Directory of Open Access Journals (Sweden)

    Jane M. Morrell

    2014-12-01

    Full Text Available Antibiotics are added to semen extenders to be used for artificial insemination (AI in livestock breeding to control bacterial contamination in semen arising during collection and processing. The antibiotics to be added and their concentrations for semen for international trade are specified by government directives. Since the animal production industry uses large quantities of semen for artificial insemination, large amounts of antibiotics are currently used in semen extenders. Possible alternatives to antibiotics are discussed, including physical removal of the bacteria during semen processing, as well as the development of novel antimicrobials. Colloid centrifugation, particularly Single Layer Centrifugation, when carried out with a strict aseptic technique, offers a feasible method for reducing bacterial contamination in semen and is a practical method for semen processing laboratories to adopt. However, none of these alternatives to antibiotics should replace strict attention to hygiene during semen collection and handling.

  3. Dosage Form Data Used for Estimating Pediatric Antibiotic Use.

    Science.gov (United States)

    Matuz, Maria; Benko, Ria; Elseviers, Monique; Hajdu, Edit; Doro, Peter; Viola, Reka; Soos, Gyongyver

    2015-01-01

    We aimed to report a simple estimation method to enable quantification of pediatric antibiotic exposure in large aggregated datasets. Secondly, we aimed to quantify and benchmark Hungarian pediatric antibiotic use. First we intended to examine whether a correlation existed between dosage form data and the patient's age. Therefore, issued prescriptions were analyzed in pharmacies. As a correlation was found between the share of liquid oral antibacterial products and the rate of pediatric antibiotic prescriptions (R=0.884; pdosage form data and patients' age. Based on this association, massive pediatric antibiotic exposure was found. Due to the general availability of dosage form data and the ease of the estimation method, the reported concept can be used to quantify pediatric antibiotic use in large aggregated datasets or when age stratification is absent.

  4. Antibiotic modulation of capsular exopolysaccharide and virulence in Acinetobacter baumannii.

    Directory of Open Access Journals (Sweden)

    Edward Geisinger

    2015-02-01

    Full Text Available Acinetobacter baumannii is an opportunistic pathogen of increasing importance due to its propensity for intractable multidrug-resistant infections in hospitals. All clinical isolates examined contain a conserved gene cluster, the K locus, which determines the production of complex polysaccharides, including an exopolysaccharide capsule known to protect against killing by host serum and to increase virulence in animal models of infection. Whether the polysaccharides determined by the K locus contribute to intrinsic defenses against antibiotics is unknown. We demonstrate here that mutants deficient in the exopolysaccharide capsule have lowered intrinsic resistance to peptide antibiotics, while a mutation affecting sugar precursors involved in both capsule and lipopolysaccharide synthesis sensitizes the bacterium to multiple antibiotic classes. We observed that, when grown in the presence of certain antibiotics below their MIC, including the translation inhibitors chloramphenicol and erythromycin, A. baumannii increases production of the K locus exopolysaccharide. Hyperproduction of capsular exopolysaccharide is reversible and non-mutational, and occurs concomitantly with increased resistance to the inducing antibiotic that is independent of the presence of the K locus. Strikingly, antibiotic-enhanced capsular exopolysaccharide production confers increased resistance to killing by host complement and increases virulence in a mouse model of systemic infection. Finally, we show that augmented capsule production upon antibiotic exposure is facilitated by transcriptional increases in K locus gene expression that are dependent on a two-component regulatory system, bfmRS. These studies reveal that the synthesis of capsule, a major pathogenicity determinant, is regulated in response to antibiotic stress. Our data are consistent with a model in which gene expression changes triggered by ineffectual antibiotic treatment cause A. baumannii to transition

  5. ANTIBIOTIC PROPHYLAXIS ON ESTOMATOLOGY

    OpenAIRE

    Rodríguez Alfaro, Miguel; Responsable de la cátedra de Farmacología de la Facultad de Odontología UNMSM.; Burga Sánchez, Jonny; Catedrático de Farmacología de la Facultad de Odontología UNMSM.; Chumpitaz Cerrate, Víctor; Catedrático de Farmacología de la Facultad de Odontología UNMSM.; Varas Hilario, Roberto; Catedrático de Farmacología de la Facultad de Odontología UNMSM.; Guerra Sanguinetti, Jaime; Cirujano Dentista de la Facultad de Odontología UNMSM.; López Bellido, Roger; Bachiller de la Facultad de Odontología UNMSM.; Zegarra Cuya, Juan; Interno de la Facultad de OdontoIogia UNMSM.

    2014-01-01

    Surgical antibiotic prophylaxis consists in the use of an antimicrobial drug in a preventive way, that must be active against microorganisms that in high frequency causes posterior infections of our surgical wounds and maintain effective tissue concentrations along the surgery procedure and the posterior time when appears the bacteremia. To reach a successful treatment is necessary to have the knowledge of the resident bactemial flora and the pathogenous flora that infects our surgical wounds...

  6. Rapid optical determination of β-lactamase and antibiotic activity

    Science.gov (United States)

    2014-01-01

    Background The absence of rapid tests evaluating antibiotic susceptibility results in the empirical prescription of antibiotics. This can lead to treatment failures due to escalating antibiotic resistance, and also furthers the emergence of drug-resistant bacteria. This study reports a rapid optical method to detect β-lactamase and thereby assess activity of β-lactam antibiotics, which could provide an approach for targeted prescription of antibiotics. The methodology is centred on a fluorescence quenching based probe (β-LEAF – β-Lactamase Enzyme Activated Fluorophore) that mimics the structure of β-lactam antibiotics. Results The β-LEAF assay was performed for rapid determination of β-lactamase production and activity of β-lactam antibiotic (cefazolin) on a panel of Staphylococcus aureus ATCC strains and clinical isolates. Four of the clinical isolates were determined to be lactamase producers, with the capacity to inactivate cefazolin, out of the twenty-five isolates tested. These results were compared against gold standard methods, nitrocefin disk test for β-lactamase detection and disk diffusion for antibiotic susceptibility, showing results to be largely consistent. Furthermore, in the sub-set of β-lactamase producers, it was demonstrated and validated that multiple antibiotics (cefazolin, cefoxitin, cefepime) could be assessed simultaneously to predict the antibiotic that would be most active for a given bacterial isolate. Conclusions The study establishes the rapid β-LEAF assay for β-lactamase detection and prediction of antibiotic activity using S. aureus clinical isolates. Although the focus in the current study is β-lactamase-based resistance, the overall approach represents a broad diagnostic platform. In the long-term, these studies form the basis for the development of assays utilizing a broader variety of targets, pathogens and drugs. PMID:24708478

  7. Surveillance of antibiotic resistance

    Science.gov (United States)

    Johnson, Alan P.

    2015-01-01

    Surveillance involves the collection and analysis of data for the detection and monitoring of threats to public health. Surveillance should also inform as to the epidemiology of the threat and its burden in the population. A further key component of surveillance is the timely feedback of data to stakeholders with a view to generating action aimed at reducing or preventing the public health threat being monitored. Surveillance of antibiotic resistance involves the collection of antibiotic susceptibility test results undertaken by microbiology laboratories on bacteria isolated from clinical samples sent for investigation. Correlation of these data with demographic and clinical data for the patient populations from whom the pathogens were isolated gives insight into the underlying epidemiology and facilitates the formulation of rational interventions aimed at reducing the burden of resistance. This article describes a range of surveillance activities that have been undertaken in the UK over a number of years, together with current interventions being implemented. These activities are not only of national importance but form part of the international response to the global threat posed by antibiotic resistance. PMID:25918439

  8. National hospital antibiotic timing measures for pneumonia and antibiotic overuse.

    Science.gov (United States)

    Drake, Douglas E; Cohen, Abigail; Cohn, Jeffrey

    2007-01-01

    The development of drug-resistant bacteria from the overuse of antibiotics is a serious problem, with overutilization threatening to disarm caregivers and their patients even as together they face increasingly virulent strains of microbes. On the other hand, the speedy treatment of pneumonia with antibiotics is a firmly established, evidence-based practice, enshrined in Joint Commission on Accreditation for Healthcare Organizations Core Measures used in hospital accrediting and public reporting, and in Centers for Medicare and Medicaid Services (CMS) public-reporting and pay-for-performance hospital measures. This sets the stage for a potential conflict between (a) not doing the wrong thing by overprescribing antibiotics and (b) prescribing antibiotics on time for pneumonia. In November 2005, pneumonia antibiotic timing results were announced for the 133 top-performing hospitals in the first year of the 3-year CMS Hospital Quality Incentive Demonstration (HQID) pay-for-performance project, conducted in collaboration with Premier Inc, a hospital purchasing and informatics alliance. Premier client hospitals participating in the HQID also submit drug utilization and other comparative data to Premier for client access for benchmarking purposes; this makes it possible to see how the antibiotics specified for pneumonia are used by Premier hospitals for other conditions. In this study we look at where increased success in meeting the HQID pneumonia antibiotic timing measure is tied to an increase in antibiotic use for conditions where antibiotics are unwarranted--with the potential for promoting antibiotic resistance.

  9. Silver enhances antibiotic activity against gram-negative bacteria.

    Science.gov (United States)

    Morones-Ramirez, J Ruben; Winkler, Jonathan A; Spina, Catherine S; Collins, James J

    2013-06-19

    A declining pipeline of clinically useful antibiotics has made it imperative to develop more effective antimicrobial therapies, particularly against difficult-to-treat Gram-negative pathogens. Silver has been used as an antimicrobial since antiquity, yet its mechanism of action remains unclear. We show that silver disrupts multiple bacterial cellular processes, including disulfide bond formation, metabolism, and iron homeostasis. These changes lead to increased production of reactive oxygen species and increased membrane permeability of Gram-negative bacteria that can potentiate the activity of a broad range of antibiotics against Gram-negative bacteria in different metabolic states, as well as restore antibiotic susceptibility to a resistant bacterial strain. We show both in vitro and in a mouse model of urinary tract infection that the ability of silver to induce oxidative stress can be harnessed to potentiate antibiotic activity. Additionally, we demonstrate in vitro and in two different mouse models of peritonitis that silver sensitizes Gram-negative bacteria to the Gram-positive-specific antibiotic vancomycin, thereby expanding the antibacterial spectrum of this drug. Finally, we used silver and antibiotic combinations in vitro to eradicate bacterial persister cells, and show both in vitro and in a mouse biofilm infection model that silver can enhance antibacterial action against bacteria that produce biofilms. This work shows that silver can be used to enhance the action of existing antibiotics against Gram-negative bacteria, thus strengthening the antibiotic arsenal for fighting bacterial infections.

  10. Suppression of antibiotic resistance acquisition by combined use of antibiotics.

    Science.gov (United States)

    Suzuki, Shingo; Horinouchi, Takaaki; Furusawa, Chikara

    2015-10-01

    We analyzed the effect of combinatorial use of antibiotics with a trade-off relationship of resistance, i.e., resistance acquisition to one drug causes susceptibility to the other drug, and vice versa, on the evolution of antibiotic resistance. We demonstrated that this combinatorial use of antibiotics significantly suppressed the acquisition of resistance. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. Functional Repertoire of Antibiotic Resistance Genes in Antibiotic Manufacturing Effluents and Receiving Freshwater Sediments.

    Science.gov (United States)

    González-Plaza, Juan J; Šimatović, Ana; Milaković, Milena; Bielen, Ana; Wichmann, Fabienne; Udiković-Kolić, Nikolina

    2017-01-01

    Environments polluted by direct discharges of effluents from antibiotic manufacturing are important reservoirs for antibiotic resistance genes (ARGs), which could potentially be transferred to human pathogens. However, our knowledge about the identity and diversity of ARGs in such polluted environments remains limited. We applied functional metagenomics to explore the resistome of two Croatian antibiotic manufacturing effluents and sediments collected upstream of and at the effluent discharge sites. Metagenomic libraries built from an azithromycin-production site were screened for resistance to macrolide antibiotics, whereas the libraries from a site producing veterinary antibiotics were screened for resistance to sulfonamides, tetracyclines, trimethoprim, and beta-lactams. Functional analysis of eight libraries identified a total of 82 unique, often clinically relevant ARGs, which were frequently found in clusters and flanked by mobile genetic elements. The majority of macrolide resistance genes identified from matrices exposed to high levels of macrolides were similar to known genes encoding ribosomal protection proteins, macrolide phosphotransferases, and transporters. Potentially novel macrolide resistance genes included one most similar to a 23S rRNA methyltransferase from Clostridium and another, derived from upstream unpolluted sediment, to a GTPase HflX from Emergencia . In libraries deriving from sediments exposed to lower levels of veterinary antibiotics, we found 8 potentially novel ARGs, including dihydrofolate reductases and beta-lactamases from classes A, B, and D. In addition, we detected 7 potentially novel ARGs in upstream sediment, including thymidylate synthases, dihydrofolate reductases, and class D beta-lactamase. Taken together, in addition to finding known gene types, we report the discovery of novel and diverse ARGs in antibiotic-polluted industrial effluents and sediments, providing a qualitative basis for monitoring the dispersal of ARGs

  12. Ready for a world without antibiotics? The Pensières Antibiotic Resistance Call to Action

    Directory of Open Access Journals (Sweden)

    Carlet Jean

    2012-02-01

    Full Text Available Abstract Resistance to antibiotics has increased dramatically over the past few years and has now reached a level that places future patients in real danger. Microorganisms such as Escherichia coli and Klebsiella pneumoniae, which are commensals and pathogens for humans and animals, have become increasingly resistant to third-generation cephalosporins. Moreover, in certain countries, they are also resistant to carbapenems and therefore susceptible only to tigecycline and colistin. Resistance is primarily attributed to the production of beta-lactamase genes located on mobile genetic elements, which facilitate their transfer between different species. In some rare cases, Gram-negative rods are resistant to virtually all known antibiotics. The causes are numerous, but the role of the overuse of antibiotics in both humans and animals is essential, as well as the transmission of these bacteria in both the hospital and the community, notably via the food chain, contaminated hands, and between animals and humans. In addition, there are very few new antibiotics in the pipeline, particularly for Gram-negative bacilli. The situation is slightly better for Gram-positive cocci as some potent and novel antibiotics have been made available in recent years. A strong and coordinated international programme is urgently needed. To meet this challenge, 70 internationally recognized experts met for a two-day meeting in June 2011 in Annecy (France and endorsed a global call to action ("The Pensières Antibiotic Resistance Call to Action". Bundles of measures that must be implemented simultaneously and worldwide are presented in this document. In particular, antibiotics, which represent a treasure for humanity, must be protected and considered as a special class of drugs.

  13. Mass loading and removal of pharmaceuticals and personal care products including psychoactives, antihypertensives, and antibiotics in two sewage treatment plants in southern India.

    Science.gov (United States)

    Subedi, Bikram; Balakrishna, Keshava; Joshua, Derrick Ian; Kannan, Kurunthachalam

    2017-01-01

    Environmental contamination by pharmaceuticals and personal care products (PPCPs) is barely studied in India despite being one of the largest global producers and consumers of pharmaceuticals. In this study, 29 pharmaceuticals and six metabolites were determined in sewage treatment plants (STPs) in Udupi (STPU: population served ∼150,000) and Mangalore (STPM: population served ∼450,000); the measured mean concentrations ranged from 12 to 61,000 ng/L and 5.0 to 31,000 ng/L, respectively. Atorvastatin (the most prescribed antihypercholesterolemic in India), mefenamic acid, and paraxanthine were found for the first time in wastewater in India at the mean concentrations of 395 ng/L, 1100 ng/L, and 13,000 ng/L, respectively. Select pharmaceutical metabolites (norverapamil and clopidogrel carboxylic acid) were found at concentrations of upto 7 times higher than their parent drugs in wastewater influent and effluent. This is the first study in India to report mass loading and emission of PPCPs and their select metabolites in STPs. The total mass load of all PPCPs analyzed in this study at STPU (4.97 g/d/1000 inhabitants) was 3.6 times higher than calculated for STPM. Select recalcitrant PPCPs (carbamazepine, diazepam, and clopidogrel) were found to have negative or no removal from STPU while additional treatment with upflow anaerobic sludge blanket reactor at STPM removed (up to 95%) these PPCPs from STPM. Overall, 5.1 kg of caffeine, 4.1 kg of atenolol, 2.7 kg of ibuprofen, and 1.9 kg of triclocarban were discharged annually from STPU. The PPCP contamination profile in the Indian STP was compared with a similar study in the USA. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Contamination of organic nutrient sources with potentially toxic elements, antibiotics and pathogen microorganisms in relation to P fertilizer potential and treatment options for the production of sustainable fertilizers: A review.

    Science.gov (United States)

    Bloem, E; Albihn, A; Elving, J; Hermann, L; Lehmann, L; Sarvi, M; Schaaf, T; Schick, J; Turtola, E; Ylivainio, K

    2017-12-31

    Organic nutrient sources such as farmyard manure, sewage sludge, their biogas digestates or other animal by-products can be valuable fertilizers delivering organic matter to the soil. Currently, especially phosphorus (P) is in the focus of research since it is an essential plant nutrient with finite resources, estimated to last only for some more decades. Efficient utilization of organic P sources in agriculture will help to preserve P resources and thereby has the potential to close nutrient cycles and prevent unwanted P-losses to the environment, one of the major causes for eutrophication of water bodies. Unfortunately, organic P sources usually contain also various detrimental substances, such as potentially toxic elements or organic contaminants like pharmaceuticals as well as pathogenic microorganisms. Additionally, the utilization of some of these substrates such as sewage sludge or animal by-products is legally limited in agriculture because of the potential risk to contaminate sites with potentially toxic elements and organic contaminants. Thus, to close nutrient cycles it is important to develop solutions for the responsible use of organic nutrient sources. The aim of this review is to give an overview of the contamination of the most important organic nutrient sources with potentially toxic elements, antibiotics (as one important organic contaminant) and pathogenic microorganisms. Changes in manure and sewage sludge management as well as the increasing trend to use such substrates in biogas plants will be discussed with respect to potential risks posed to soils and water bodies. Some examples for abatement options by which contamination can be reduced to produce P fertilizers with high amounts of plant available P forms are presented. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Optimization of media for production of bioactive compounds by ...

    African Journals Online (AJOL)

    Streptomyces are economically and biotechnologically valuable prokaryotes responsible for production of bioactive secondary metabolites, notably antibiotics, ... create a great potential for upscaling secondary metabolites such as antibiotics and might remain an area of research interest in the future antibiotic discovery.

  16. The macrolide antibiotic renaissance.

    Science.gov (United States)

    Dinos, George P

    2017-09-01

    Macrolides represent a large family of protein synthesis inhibitors of great clinical interest due to their applicability to human medicine. Macrolides are composed of a macrocyclic lactone of different ring sizes, to which one or more deoxy-sugar or amino sugar residues are attached. Macrolides act as antibiotics by binding to bacterial 50S ribosomal subunit and interfering with protein synthesis. The high affinity of macrolides for bacterial ribosomes, together with the highly conserved structure of ribosomes across virtually all of the bacterial species, is consistent with their broad-spectrum activity. Since the discovery of the progenitor macrolide, erythromycin, in 1950, many derivatives have been synthesised, leading to compounds with better bioavailability and acid stability and improved pharmacokinetics. These efforts led to the second generation of macrolides, including well-known members such as azithromycin and clarithromycin. Subsequently, in order to address increasing antibiotic resistance, a third generation of macrolides displaying improved activity against many macrolide resistant strains was developed. However, these improvements were accompanied with serious side effects, leading to disappointment and causing many researchers to stop working on macrolide derivatives, assuming that this procedure had reached the end. In contrast, a recent published breakthrough introduced a new chemical platform for synthesis and discovery of a wide range of diverse macrolide antibiotics. This chemical synthesis revolution, in combination with reduction in the side effects, namely, 'Ketek effects', has led to a macrolide renaissance, increasing the hope for novel and safe therapeutic agents to combat serious human infectious diseases. © 2017 The British Pharmacological Society.

  17. Antibiotics in late clinical development.

    Science.gov (United States)

    Fernandes, Prabhavathi; Martens, Evan

    2017-06-01

    Most pharmaceutical companies have stopped or have severely limited investments to discover and develop new antibiotics to treat the increasing prevalence of infections caused by multi-drug resistant bacteria, because the return on investment has been mostly negative for antibiotics that received marketing approved in the last few decades. In contrast, a few small companies have taken on this challenge and are developing new antibiotics. This review describes those antibiotics in late-stage clinical development. Most of them belong to existing antibiotic classes and a few with a narrow spectrum of activity are novel compounds directed against novel targets. The reasons for some of the past failures to find new molecules and a path forward to help attract investments to fund discovery of new antibiotics are described. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Antibiotic prescribing for acute bronchitis.

    Science.gov (United States)

    Llor, Carl; Bjerrum, Lars

    2016-07-01

    Acute bronchitis is a self-limiting infectious disease characterized by acute cough with or without sputum but without signs of pneumonia. About 90% of cases are caused by viruses. Antibiotics for acute bronchitis have been associated with an approximately half-day reduction in duration of cough. However, at follow-up there are no significant differences in overall clinical improvement inpatients treated with antibiotics compared with those receiving placebo. Despite this, antibiotics are administered to approximately two thirds of these patients. This review discusses the reason for this antibiotic overprescription. Other therapies targeted to control symptoms have also demonstrated a marginal or no effect. Expert commentary: Clinicians should be aware of the marginal effectiveness of antibiotic therapy. Some strategies like the use of rapid tests, delayed prescribing of antibiotics and the use of leaflets for patients have been associated with a reduction of their unnecessary utilization.

  19. Antibiotic prevention of postcataract endophthalmitis

    DEFF Research Database (Denmark)

    Kessel, Line; Flesner, Per; Andresen, Jens

    2015-01-01

    Endophthalmitis is one of the most feared complications after cataract surgery. The aim of this systematic review was to evaluate the effect of intracameral and topical antibiotics on the prevention of endophthalmitis after cataract surgery. A systematic literature review in the MEDLINE, CINAHL......, Cochrane Library and EMBASE databases revealed one randomized trial and 17 observational studies concerning the prophylactic effect of intracameral antibiotic administration on the rate of endophthalmitis after cataract surgery. The effect of topical antibiotics on endophthalmitis rate was reported by one...... with the use of intracameral antibiotic administration of cefazolin, cefuroxime and moxifloxacin, whereas no effect was found with the use of topical antibiotics or intracameral vancomycin. Endophthalmitis occurred on average in one of 2855 surgeries when intracameral antibiotics were used compared to one...

  20. A study of antibiotic prescribing

    DEFF Research Database (Denmark)

    Jaruseviciene, L.; Radzeviciene-Jurgute, R.; Jurgutis, A.

    2012-01-01

    Background. Globally, general practitioners (GPs) write more than 90% of all antibiotic prescriptions. This study examines the experiences of Lithuanian and Russian GPs in antibiotic prescription for upper respiratory tract infections, including their perceptions of when it is not indicated...... clinically or pharmacologically. Methods. 22 Lithuanian and 29 Russian GPs participated in five focus group discussions. Thematic analysis was used to analyse the data. Results. We identified four main thematic categories: patients' faith in antibiotics as medication for upper respiratory tract infections......; patient potential to influence a GP's decision to prescribe antibiotics for upper respiratory tract infections; impediments perceived by GPs in advocating clinically grounded antibiotic prescribing with their patients, and strategies applied in physician-patient negotiation about antibiotic prescribing...

  1. The Prevalence of Multiple Antibiotic Resistance in Campylobacter spp. From Retail Poultry Meat

    OpenAIRE

    Marija Kurinčič; Ingrid Berce; Tina Zorman; Sonja Smole Možina

    2005-01-01

    Macrolides and fluoroquinolones are regarded as drugs of choice for the treatment of human Campylobacter infections. The use of antimicrobials for this purpose as well as in food animal production has resulted in the resistance of Campylobacter spp. to selected antibiotics. Since poultry is one of the most important sources of human Campylobacter infections the use of antibiotics in animal production can shorten the effective therapeutic life of antibiotics for human use. During 2001–2003, ov...

  2. Antibiotic Resistance in Nephrological Practice

    Directory of Open Access Journals (Sweden)

    O.I. Taran

    2017-03-01

    Full Text Available The problem of antibiotic resistance is a serious threat to the global public health and requires action by both the state and the public. The World Health Organization identified 15 most dangerous and prevalent superbugs, which it ranked based on three levels of threat they present to the public health. At the heart of the fight against antibiotic resistance lies the increased awareness of the health professionals and general public that incorrect and excessive use of antibiotics amid poor practices in infection prevention and control contributes to the acceleration of antibiotic resistance.

  3. [Usage of antibiotics in hospitals].

    Science.gov (United States)

    Ternák, G; Almási, I

    1996-12-29

    The authors publish the results of a survey conducted among hospital records of patients discharged from eight inpatient's institutes between 1-31st of January 1995 to gather information on the indications and usage of antibiotics. The institutes were selected from different part of the country to represent the hospital structure as much as possible. Data from the 13,719 documents were recorded and analysed by computer program. It was found that 27.6% of the patients (3749 cases) received antibiotic treatment. 407 different diagnosis and 365 different surgical procedures (as profilaxis) were considered as indications of antibiotic treatment (total: 4450 indications for 5849 antibiotic treatment). The largest group of patients receiving antibiotics was of antibiotic profilaxis (24.56%, 1093 cases), followed by lower respiratory tract infections (19.89%, 849 cases), uroinfections (10.53%, 469 cases) and upper respiratory tract infections. Relatively large group of patients belonged to those who had fever or subfebrility without known reason (7.35%, 327 cases) and to those who did not have any proof in their document indicating the reasons of antibiotic treatment (6.4%, 285 cases). We can not consider the antibiotic indications well founded in those groups of patients (every sixth or every fifth cases). The most frequently used antibiotics were of [2-nd] generation cefalosporins. The rate of nosocomial infections were found as 6.78% average. The results are demonstrated on diagrams and table.

  4. The antibiotic resistome: what's new?

    Science.gov (United States)

    Perry, Julie Ann; Westman, Erin Louise; Wright, Gerard D

    2014-10-01

    The antibiotic resistome is dynamic and ever expanding, yet its foundations were laid long before the introduction of antibiotics into clinical practice. Here, we revisit our theoretical framework for the resistome concept and consider the many factors that influence the evolution of novel resistance genes, the spread of mobile resistance elements, and the ramifications of these processes for clinical practice. Observing the trends and prevalence of genes within the antibiotic resistome is key to maintaining the efficacy of antibiotics in the clinic. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Antibiotic resistance of Neisseria gonorrhoeae isolated from gonorrhoeae patients

    OpenAIRE

    Mohammad Bokaeian; Mazhar Iqbal-Qureshi; Soroush Dabiri

    2010-01-01

    Background: The objective of this study was to determine antibiotic susceptibility and penicillinase production by Neisseria gonorrhoeae strains isolated from gonorrhoeae patients in Zahedan.Materials and methods: In a descriptive study during 2005-2008 years, 400 suspected patients were studied by history review, medical examination, gram staining and culture in Thayer-Martin medium. Antibiotic susceptibility and penicillinase tests of isolated strains were done by disk diffusion method and ...

  6. Antibiotics can ameliorate circulatory complications of liver cirrhosis

    DEFF Research Database (Denmark)

    Madsen, Bjørn Stæhr; Schaffalitzky de Muckadell, Ove B

    2011-01-01

    Livercirrhosis can be complicated by a hyperdynamic circulatory syndrome. This is due to translocation of bacteria and bacterial product (bacterial DNA and endotoxins), which stimulate the splanchnic nitric oxide synthase and leads to splanchnic vasodilatation and haemodynamic derangement....... This review focuses on how broad spectrum antibiotics can ameliorate the haemodynamic consequences of bacterial translocation. It is possible that the use of broad spectrum antibiotics in the future may be used to prevent other complications of liver cirrhosis than spontaneous bacterial peritonitis...

  7. Inhibition of Paramecium caudatum by an Alteromonas luteoviolacea antibiotic.

    Science.gov (United States)

    Kamei, Y; McCarthy, S A; Kakimoto, D; Johnson, R M

    1986-01-01

    An antibiotic factor obtained from Alteromonas luteoviolacea was shown to kill Paramecium caudatum. This substance was shown to be destroyed by boiling, sonication, or freezing. It passed through a 0.45-micron-pore-size filter and was not precipitated from a culture supernatant with ethyl alcohol. Its production varied with A. luteoviolacea strains and medium constituents. It was also shown to be distinct from the A. luteoviolacea antibiotic that affects bacterial cells. PMID:3767343

  8. Fighting antibiotic resistance in the intensive care unit using antibiotics

    NARCIS (Netherlands)

    Plantinga, Nienke L.; Wittekamp, Bastiaan H J; Van Duijn, Pleun J.; Bonten, Marc J M|info:eu-repo/dai/nl/123144337

    2015-01-01

    Antibiotic resistance is a global and increasing problem that is not counterbalanced by the development of new therapeutic agents. The prevalence of antibiotic resistance is especially high in intensive care units with frequently reported outbreaks of multidrug-resistant organisms. In addition to

  9. [Early Results of Adjuvant Topical Treatment of Recurrent Osteomyelitis with Absorbable Antibiotic Carriers].

    Science.gov (United States)

    Gramlich, Y; Walter, G; Gils, J; Hoffmann, R

    2017-02-01

    arbitrary, water-soluble antibiotic. Systemic administration of antibiotics was carried out in parallel in accordance with the resistogram. Results The most common clinical entities were femoral (36 %) and tibial (29 %) osteitis. Vancomycin (38 %) and tobramycin (38 %) were the most frequently used topical antibiotics, followed by gentamycin (17 %), ceftriaxone (4 %), fosfomycin (2 %) and colistin (1 %). Systemic administration of antibiotics was carried out in parallel, in accordance with the resistogram. In 85 % of all patients, remission was achieved. Infections with methicillin-resistant Staphylococcus aureus (MRSA; 62 %) and Pseudomonas aeruginosa (43 %) showed significantly poorer remission rates. The bacterial spectrum was primarily composed of Staphylococcus aureus (28 %), Staphylococcus epidermidis (22 %), Pseudomonas aeruginosa (7 %) and Enterococcus faecalis (5 %), as well as Escherichia coli and Klebsiella oxytoca (4 %). Conclusion Topical adjuvant antibiotic therapy based on an absorbable carrier system offers an expedient extension of the treatment of osteomyelitis. The remission rate of 85 % for recurrent infections encouraged the use of a therapeutic alternative for many patients. We developed an algorithm for the treatment of osteomyelitis, which includes the application of local antibiotics with different compositions and absorbable carriers. We present early results of successful treatment of patients with recurrent osteomyelitis, after futile topical therapy with non-absorbable antibiotic chains. Georg Thieme Verlag KG Stuttgart · New York.

  10. Antibiotic adjuvants - A strategy to unlock bacterial resistance to antibiotics.

    Science.gov (United States)

    González-Bello, Concepción

    2017-09-15

    Resistance to available antibiotics in pathogenic bacteria is currently a global challenge since the number of strains that are resistant to multiple types of antibiotics has increased dramatically each year and has spread worldwide. To unlock this problem, the use of an 'antibiotic adjuvant' in combination with an antibiotic is now being exploited. This approach enables us to prolong the lifespan of these life-saving drugs. This digests review provides an overview of the main types of antibiotic adjuvants, the basis of their operation and the remaining issues to be tackled in this field. Particular emphasis is placed on those compounds that are already in clinical development, namely β-lactamase inhibitors. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  11. Monitoring Antibiotic Use and Residue in Freshwater Aquaculture for Domestic Use in Vietnam.

    Science.gov (United States)

    Pham, Dang Kim; Chu, Jacqueline; Do, Nga Thuy; Brose, François; Degand, Guy; Delahaut, Philippe; De Pauw, Edwin; Douny, Caroline; Nguyen, Kinh Van; Vu, Ton Dinh; Scippo, Marie-Louise; Wertheim, Heiman F L

    2015-09-01

    Vietnam is an important producer of aquaculture products, and aquatic products are essential to the Vietnamese diet. However, Vietnam also has very little enforced regulation pertaining to antibiotic usage in domestic aquaculture, which raises concerns for antibiotic resistance in pathogenic bacteria. In this study, analysis was conducted on the presence of antibiotic residues in domestically sold fish and shrimp raised in freshwater farms in Vietnam, and an assessment of farmers' knowledge of proper antibiotics usage was performed. The results indicated that a quarter of tested aquaculture products were antibiotic screening test positive, and there is a general lack of knowledge about the purpose and proper usage of antibiotics by aquaculture producers. Farmers' decision-making processes about antimicrobial use are influenced by biased sources of information, such as drug manufacturers and sellers, and by financial incentives.

  12. Administrative Expedience and the Avoidance of Scandal: Ireland’s Industrial and Reformatory Schools and the Inter-Departmental Committee of 1962-3

    Directory of Open Access Journals (Sweden)

    Anthony Keating

    2015-03-01

    Full Text Available This article utilises the surviving working papers of the Irish, Inter-Departmental Committee on the Prevention of Crime and Treatment of Offenders of 1962-3 (IDC to critically evaluate its work on the industrial and reformatory schools. The industrial and reformatory schools were populated by vulnerable children, from largely poor backgrounds, who were not well regarded by Irish society. The work of the IDC in regard to adult prisoners is argued by academics and politicians to have been a turning point in Irish penal policy; representing the point at which a more enlightened approach to the treatment of offenders began to feed through into the penal system. This positive assessment of the IDC’s impact on adult penal policy is demonstrated to stand in stark contrast to its actions in regard to the children detained in the industrial and reformatory schools. Children, against whose interests, the IDC and its political masters chose to place economic expediency and the perceived interests of departmental and religio-political sensibilities. The actions of the IDC left these children exposed to the worst excesses of abusive institutions despite clear evidence of their plight. It was not until the years after the publication of the Kennedy Report in 1970 that the Irish State took it first hesitant steps in reforming the rotten and abusive system.

  13. Feed additive strategies for replacement of antimicrobial growth promoters and a responsible use of antibiotics

    NARCIS (Netherlands)

    Hartog, den L.A.; Smits, C.H.M.; Hendriks, W.H.

    2016-01-01

    The rapid development of antimicrobial resistance (AMR) in human health care urges the need for effective strategies to reduce antibiotic use in animal production. The Netherlands and Denmark have already implemented successful strategies to reduce antibiotic usage in animal production. Part of the

  14. Alternatives to antibiotics-a pipeline portfolio review.

    Science.gov (United States)

    Czaplewski, Lloyd; Bax, Richard; Clokie, Martha; Dawson, Mike; Fairhead, Heather; Fischetti, Vincent A; Foster, Simon; Gilmore, Brendan F; Hancock, Robert E W; Harper, David; Henderson, Ian R; Hilpert, Kai; Jones, Brian V; Kadioglu, Aras; Knowles, David; Ólafsdóttir, Sigríður; Payne, David; Projan, Steve; Shaunak, Sunil; Silverman, Jared; Thomas, Christopher M; Trust, Trevor J; Warn, Peter; Rex, John H

    2016-02-01

    Antibiotics have saved countless lives and enabled the development of modern medicine over the past 70 years. However, it is clear that the success of antibiotics might only have been temporary and we now expect a long-term and perhaps never-ending challenge to find new therapies to combat antibiotic-resistant bacteria. A broader approach to address bacterial infection is needed. In this Review, we discuss alternatives to antibiotics, which we defined as non-compound approaches (products other than classic antibacterial agents) that target bacteria or any approaches that target the host. The most advanced approaches are antibodies, probiotics, and vaccines in phase 2 and phase 3 trials. This first wave of alternatives to antibiotics will probably best serve as adjunctive or preventive therapies, which suggests that conventional antibiotics are still needed. Funding of more than £1·5 billion is needed over 10 years to test and develop these alternatives to antibiotics. Investment needs to be partnered with translational expertise and targeted to support the validation of these approaches in phase 2 trials, which would be a catalyst for active engagement and investment by the pharmaceutical and biotechnology industry. Only a sustained, concerted, and coordinated international effort will provide the solutions needed for the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Antibiotic Prophylaxis in Pediatric Dentistry

    Directory of Open Access Journals (Sweden)

    Davydova N.V.

    2011-03-01

    Full Text Available Identify options for the indications for antibiotic prophylaxis in children's dental reception. The analysis of publications shows that the basis of current trends prevention of postoperative wound infection in pediatric surgery should be measures aimed at eliminating or reducing the influence of risk factors, as well as the use of antibiotic prophylaxis

  16. The Antibiotic Resistance Problem Revisited

    Science.gov (United States)

    Lawson, Michael A.

    2008-01-01

    The term "antibiotic" was first proposed by Vuillemin in 1889 but was first used in the current sense by Walksman in 1941. An antibiotic is defined as a "derivative produced by the metabolism of microorganisms that possess antibacterial activity at low concentrations and is not toxic to the host." In this article, the author describes how…

  17. Antibiotics, pediatric dysbiosis, and disease.

    Science.gov (United States)

    Vangay, Pajau; Ward, Tonya; Gerber, Jeffrey S; Knights, Dan

    2015-05-13

    Antibiotics are by far the most common medications prescribed for children. Recent epidemiological data suggests an association between early antibiotic use and disease phenotypes in adulthood. Antibiotic use during infancy induces imbalances in gut microbiota, called dysbiosis. The gut microbiome's responses to antibiotics and its potential link to disease development are especially complex to study in the changing infant gut. Here, we synthesize current knowledge linking antibiotics, dysbiosis, and disease and propose a framework for studying antibiotic-related dysbiosis in children. We recommend future studies into the microbiome-mediated effects of antibiotics focused on four types of dysbiosis: loss of keystone taxa, loss of diversity, shifts in metabolic capacity, and blooms of pathogens. Establishment of a large and diverse baseline cohort to define healthy infant microbiome development is essential to advancing diagnosis, interpretation, and eventual treatment of pediatric dysbiosis. This approach will also help provide evidence-based recommendations for antibiotic usage in infancy. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. STREPTOMYCINOID ANTIBIOTICS: SYNERGISM BY PUROMYCIN.

    Science.gov (United States)

    WHITE, J R; WHITE, H L

    1964-11-06

    Puromycin synergizes the lethal action of streptomycin and related antibiotics. This is interpreted to mean that puromycin action uncovers a sensitive site (or sites) on the 30S ribosome. The streptomycinoid antibiotics can then associate more readily with the ribosome and inhibit further synthesis of valid protein.

  19. Enteropathogens and antibiotics.

    Science.gov (United States)

    González-Torralba, Ana; García-Esteban, Coral; Alós, Juan-Ignacio

    2018-01-01

    Infectious gastroenteritis remains a public health problem. The most severe cases are of bacterial origin. In Spain, Campylobacter and Salmonella are the most prevalent bacterial genus, while Yersinia and Shigella are much less frequent. Most cases are usually self-limiting and antibiotic therapy is not generally indicated, unless patients have risk factors for severe infection and shigellosis. Ciprofloxacin, third generation cephalosporins, azithromycin, ampicillin, cotrimoxazole and doxycycline are the most recommended drugs. The susceptibility pattern of the different bacteria determines the choice of the most appropriate treatment. The aim of this review is to analyse the current situation, developments, and evolution of resistance and multidrug resistance in these 4 enteric pathogens. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  20. Systemic antibiotics in periodontal therapy.

    Science.gov (United States)

    Heitz-Mayfield, L J A

    2009-09-01

    Periodontitis is a biofilm infection with a mixed microbial aetiology. Periodontitis is generally treated by non-surgical mechanical debridement and regular periodontal maintenance care. Periodontal surgery may be indicated for some patients to improve access to the root surface for mechanical debridement. A range of systemic antibiotics for treatment of periodontitis has been documented, with some studies showing superior clinical outcomes following adjunctive antibiotics while others do not. This has resulted in controversy as to the role of systemic antibiotics in the treatment of periodontal diseases. Recent systematic reviews have provided an evidence-based assessment of the possible benefits of adjunctive antibiotics in periodontal therapy. This review aims to provide an update on clinical issues of when and how to prescribe systemic antibiotics in periodontal therapy.

  1. New approaches to antibiotic discovery.

    Science.gov (United States)

    Kealey, C; Creaven, C A; Murphy, C D; Brady, C B

    2017-06-01

    New antibiotics are urgently required by human medicine as pathogens emerge with developed resistance to almost all antibiotic classes. Pioneering approaches, methodologies and technologies have facilitated a new era in antimicrobial discovery. Innovative culturing techniques such as iChip and co-culturing methods which use 'helper' strains to produce bioactive molecules have had notable success. Exploiting antibiotic resistance to identify antibacterial producers performed in tandem with diagnostic PCR based identification approaches has identified novel candidates. Employing powerful metagenomic mining and metabolomic tools has identified the antibiotic'ome, highlighting new antibiotics from underexplored environments and silent gene clusters enabling researchers to mine for scaffolds with both a novel mechanism of action and also few clinically established resistance determinants. Modern biotechnological approaches are delivering but will require support from government initiatives together with changes in regulation to pave the way for valuable, efficacious, highly targeted, pathogen specific antimicrobial therapies.

  2. Antibiotics for acute maxillary sinusitis

    DEFF Research Database (Denmark)

    Ahovuo-Saloranta, Anneli; Borisenko, Oleg V; Kovanen, Niina

    2008-01-01

    BACKGROUND: Expert opinions vary on the appropriate role of antibiotics for sinusitis, one of the most commonly diagnosed conditions among adults in ambulatory care. OBJECTIVES: We examined whether antibiotics are effective in treating acute sinusitis, and if so, which antibiotic classes...... are the most effective. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2007, Issue 3); MEDLINE (1950 to May 2007) and EMBASE (1974 to June 2007). SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing antibiotics with placebo...... or antibiotics from different classes for acute maxillary sinusitis in adults. We included trials with clinically diagnosed acute sinusitis, whether or not confirmed by radiography or bacterial culture. DATA COLLECTION AND ANALYSIS: At least two review authors independently screened search results, extracted...

  3. Antibiotic treatment of biofilm infections

    DEFF Research Database (Denmark)

    Ciofu, Oana; Rojo-Molinero, Estrella; Macià, María D.

    2017-01-01

    Bacterial biofilms are associated with a wide range of infections, from those related to exogenous devices, such as catheters or prosthetic joints, to chronic tissue infections such as those occurring in the lungs of cystic fibrosis patients. Biofilms are recalcitrant to antibiotic treatment due...... to multiple tolerance mechanisms (phenotypic resistance). This causes persistence of biofilm infections in spite of antibiotic exposure which predisposes to antibiotic resistance development (genetic resistance). Understanding the interplay between phenotypic and genetic resistance mechanisms acting...... on biofilms, as well as appreciating the diversity of environmental conditions of biofilm infections which influence the effect of antibiotics are required in order to optimize the antibiotic treatment of biofilm infections. Here, we review the current knowledge on phenotypic and genetic resistance...

  4. Antibiotic prescribing for acute bronchitis

    DEFF Research Database (Denmark)

    Llor, Carl; Bjerrum, Lars

    2016-01-01

    INTRODUCTION: Acute bronchitis is a self-limiting infectious disease characterized by acute cough with or without sputum but without signs of pneumonia. About 90% of cases are caused by viruses. AREAS COVERED: Antibiotics for acute bronchitis have been associated with an approximately half......-day reduction in duration of cough. However, at follow-up there are no significant differences in overall clinical improvement inpatients treated with antibiotics compared with those receiving placebo. Despite this, antibiotics are administered to approximately two thirds of these patients. This review...... discusses the reason for this antibiotic overprescription. Other therapies targeted to control symptoms have also demonstrated a marginal or no effect. EXPERT COMMENTARY: Clinicians should be aware of the marginal effectiveness of antibiotic therapy. Some strategies like the use of rapid tests, delayed...

  5. Antibiotic tolerance and microbial biofilms

    DEFF Research Database (Denmark)

    Folkesson, Anders

    Increased tolerance to antimicrobial agents is thought to be an important feature of microbes growing in biofilms. We study the dynamics of antibiotic action within hydrodynamic flow chamber biofilms of Escherichia coli and Pseudomonas aeruginosa using isogenic mutants and fluorescent gene...... expression reporters and we address the question of how biofilm organization affects antibiotic susceptibility. The dynamics of microbial killing is monitored by viable count determination, and confocal laser microscopy. Our work shows that the apparent increased antibiotic tolerance is due to the formation...... of antibiotic tolerant subpopulations within the biofilm. The formation of these subpopulations is highly variable and dependent on the antibiotic used, the biofilm structural organization and the induction of specific tolerance mechanisms....

  6. Development of Methods for Genetic Assessment of Antibiotic Resistance In Animal Herds

    DEFF Research Database (Denmark)

    Schmidt, Gunilla Veslemøy

    -time PCR (qPCR) assays that supply an easy and rapid method for quantifying antibiotic resistance levels in animal herds. The pig production is accountable for a large portion of the antibiotics used for food producing animals in Denmark. Therefore, the antibiotic resistance genes included in this study...... from the Danish pig production. Fecal samples from wildlife and Massai cattle in Tanzania were screened for the presence of the 14 antibiotic resistance genes using the qPCR assays. The wildlife and cattle samples were collected in the Ngorongoro Conservational Area (NCA) (wildlife and cattle...

  7. Transformation products of antibiotic and cytostatic drugs in the aquatic cycle that result from effluent treatment and abiotic/biotic reactions in the environment: an increasing challenge calling for higher emphasis on measures at the beginning of the pipe.

    Science.gov (United States)

    Haddad, Tarek; Baginska, Ewelina; Kümmerer, Klaus

    2015-04-01

    Pharmaceuticals may undergo transformation into new products during almost all possible processes along their life-cycle. This could either take place in the natural water environment and/or during water treatment processes. Numerous studies that address the issue of such transformation products (TPs) have been published, describing selected aspects of TPs in the environment and their formation within effluent and water treatment processes. In order to exemplify the number and quality of information published on TPs, we selected 21 active pharmaceutical ingredients from the groups of antibiotics and antineoplastics, and assessed the knowledge about their TPs that has been published until the end of May 2012. The goal of this work was to demonstrate, that the quality of data on pharmaceutical TPs greatly differs in terms of the availability of chemical structures for each TP, rather than to provide an exhaustive database of available TPs. The aim was to point out the challenge going along with so many TPs formed under different treatment and environmental conditions. An extensive review in the form of a table showing the existing data on 158 TPs for 15 compounds, out of 21 investigated, was presented. Numerous TPs are the result of different treatments and environmental processes. However, also numerous different TPs may be formed within only one type of treatment, applied under sometimes even very similar treatment conditions and treatments times. In general, the growing number of elucidated TPs is rationalized by ineffective removal treatments. Our results demonstrate a severe risk of drowning in much unrelated and non-assessable data, both from a scientific and from a technical treatment-related point of view. Therefore, limiting the input of pharmaceuticals into effluents as well as improving their (bio) degradability and elimination behavior, instead of only relying on advanced effluent treatments, is urgently needed. Solutions that focus on this "beginning of

  8. Alternatives to antibiotics in poultry feed: molecular perspectives.

    Science.gov (United States)

    Suresh, Gayatri; Das, Ratul Kumar; Kaur Brar, Satinder; Rouissi, Tarek; Avalos Ramirez, Antonio; Chorfi, Younes; Godbout, Stephane

    2017-09-11

    The discovery of the growth promoting property of antibiotics led to their use as antibiotic feed additives (AFAs) in animal feed at sub-therapeutic doses. Although this has been beneficial for animal health and productivity, it has been, essentially, a double-edged sword. The continued and non-judicious use of AFAs has led to the selection and dissemination of antibiotic-resistant strains of poultry pathogens such as Salmonella, Campylobacter and Escherichia coli. The rapid spread of drug-resistant pathogens as well as emergence of antibiotic-related environmental pollutants is of global concern. Hence, the identification and development of new and effective alternatives to antibiotics that do not hinder productivity is imperative. For this, it is essential to understand not only the molecular basis of development of resistance to AFAs but also the mechanisms of action of AFA alternatives and how they differ from AFAs. This review provides a molecular perspective on the alternatives to antibiotics that have been proposed till date and their current trends, as well as novel approaches such as development of improved delivery systems.

  9. Detection of antibiotic resistance in probiotics of dietary supplements

    KAUST Repository

    Wong, Aloysius Tze

    2015-09-14

    Background Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive. Findings Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers. Conclusions This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.

  10. Detection of antibiotic resistance in probiotics of dietary supplements.

    Science.gov (United States)

    Wong, Aloysius; Ngu, Davey Yueh Saint; Dan, Lydia Annabel; Ooi, Amanda; Lim, Renee Lay Hong

    2015-09-14

    Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive. Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers. This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.

  11. Antibiotic-resistant bacteria: a challenge for the food industry.

    Science.gov (United States)

    Capita, Rosa; Alonso-Calleja, Carlos

    2013-01-01

    Antibiotic-resistant bacteria were first described in the 1940s, but whereas new antibiotics were being discovered at a steady rate, the consequences of this phenomenon were slow to be appreciated. At present, the paucity of new antimicrobials coming into the market has led to the problem of antibiotic resistance fast escalating into a global health crisis. Although the selective pressure exerted by the use of antibiotics (particularly overuse or misuse) has been deemed the major factor in the emergence of bacterial resistance to these antimicrobials, concerns about the role of the food industry have been growing in recent years and have been raised at both national and international levels. The selective pressure exerted by the use of antibiotics (primary production) and biocides (e.g., disinfectants, food and feed preservatives, or decontaminants) is the main driving force behind the selection and spread of antimicrobial resistance throughout the food chain. Genetically modified (GM) crops with antibiotic resistance marker genes, microorganisms added intentionally to the food chain (probiotic or technological) with potentially transferable antimicrobial resistance genes, and food processing technologies used at sub-lethal doses (e.g., alternative non-thermal treatments) are also issues for concern. This paper presents the main trends in antibiotic resistance and antibiotic development in recent decades, as well as their economic and health consequences, current knowledge concerning the generation, dissemination, and mechanisms of antibacterial resistance, progress to date on the possible routes for emergence of resistance throughout the food chain and the role of foods as a vehicle for antibiotic-resistant bacteria. The main approaches to prevention and control of the development, selection, and spread of antibacterial resistance in the food industry are also addressed.

  12. An Antibiotic Selection System For Protein Overproducing Bacteria

    DEFF Research Database (Denmark)

    Rennig, Maja; Nørholm, Morten

    2015-01-01

    membrane proteins of Escherichia coli can be used as a fast and simple selection system for protein overproduction.Methods: We designed an expression plasmid encoding the gene of interest and an additional, inducible antibiotic resistance marker. Both genes were linked by a hairpin structure...... that translationally couples the genes. Consequently, high expressing gene variants also allow for higher production of the coupled antibiotic resistance marker. Therefore, high expressing gene variants in a library can be determined either by plating the expression library on selection plates or by growing...... sequence and the start codon, an integral part of the translation initiation region. We successfully tested the expression of these libraries with the antibiotic selection system on plates and in liquid cultures.Conclusions: We successfully implemented the antibiotic selection system and confirmed enhanced...

  13. Dynamic energy budget approach to evaluate antibiotic effects on biofilms

    Science.gov (United States)

    Birnir, Bjorn; Carpio, Ana; Cebrián, Elena; Vidal, Perfecto

    2018-01-01

    Quantifying the action of antibiotics on biofilms is essential to devise therapies against chronic infections. Biofilms are bacterial communities attached to moist surfaces, sheltered from external aggressions by a polymeric matrix. Coupling a dynamic energy budget based description of cell metabolism to surrounding concentration fields, we are able to approximate survival curves measured for different antibiotics. We reproduce numerically stratified distributions of cell types within the biofilm and introduce ways to incorporate different resistance mechanisms. Qualitative predictions follow that are in agreement with experimental observations, such as higher survival rates of cells close to the substratum when employing antibiotics targeting active cells or enhanced polymer production when antibiotics are administered. The current computational model enables validation and hypothesis testing when developing therapies.

  14. Usage, residue, and human health risk of antibiotics in Chinese aquaculture: A review.

    Science.gov (United States)

    Liu, Xiao; Steele, Joshua Caleb; Meng, Xiang-Zhou

    2017-04-01

    Aquaculture is a booming industry in the world and China is the largest producer and exporter of aquatic products. To prevent and treat diseases occurred in aquaculture, antibiotics are widely applied. However, the information of antibiotics used in Chinese aquaculture is still limited. Based on peer-reviewed papers, documents, reports, and even farmer surveys, this review summarized antibiotics used in Chinese aquaculture. In 2014, more than 47.4 million tonnes of farmed aquatic products were produced in mainland China. The outputs in the east and south parts of China can reach as much as 600 times higher than those in the northwest areas, which is clearly separated by the "Hu Line" - a line that marks a striking difference in the distribution of population. A total of 20 antibiotics belonging to eight categories have been reported for use, mainly via oral administration. However, only 13 antibiotics have been authorized for application in Chinese aquaculture and 12 antibiotics used are not authorized. Totally, 234 cases on antibiotic residues in Chinese aquatic products were recorded, including 24 fish species, eight crustacean species, and four mollusk species. Thirty-two antibiotics have been detected in aquatic products; quinolones and sulfonamides were the dominated residual chemicals. For specific compound, ciprofloxacin, norfloxacin, and sulfisoxazole have the highest concentrations. Except for a few cases, all residual concentrations were lower than the maximum residue limits. Through the consumption of aquatic products tainted by antibiotics, humans may acquire adverse drug reactions or antibiotic-resistant bacteria. However, the risk of antimicrobial resistance in human body, when exposed to antibiotics at sub-inhibitory concentrations, has not been exhaustively considered in the risk assessment. In addition, a national comprehensive investigation on the amount of antibiotics used in Chinese aquaculture is still needed in future studies. Copyright

  15. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes

    KAUST Repository

    Hong, Pei-Ying

    2013-07-31

    Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.

  16. The consequences of generic marketing on antibiotic consumption and the spread of microbial resistance: the need for new antibiotics.

    Science.gov (United States)

    Toutain, P-L; Bousquet-Melou, A

    2013-10-01

    In both human and veterinary medicine, it has been shown that flooding the market with different generics and/or 'me-too' branded drugs has increased overall antibiotic consumption correlating with the emergence and spread of bacterial resistance to antibiotics. Another possible undesirable consequence of the promotion of generics is the promotion of an economic incentive that encourages the use of old drug products with very poor oral bioavailability, marketed with historical dosage regimens and extensively excreted in the environment. What veterinary medicine rather needs is new innovative and 'ecofriendly' antibiotics to actually enforce a more prudent use of antibiotics. For a pharmaceutical company, generics are inexpensive to manufacture and on a short-term basis, the generic market is very appealing. However, on a long-term basis, this marketing orientation provides a disincentive to the development of new and innovative products that will be required to meet the therapeutic needs of the veterinary community while being consistent with public health concerns. Indeed, for veterinary medicine, the key issue surrounding antibiotics is public health. It is the opinion of the authors that veterinary antibiotics and/or veterinary drug formulations should be innovative in terms of selectivity (no or minimal impact on the commensal gut flora), biodegradable (with minimal environmental disruption), and more expensive, with a strictly regulated market rather than unselective, cheap, and freely available drugs. © 2013 John Wiley & Sons Ltd.

  17. Putrescine reduces antibiotic-induced oxidative stress as a mechanism of modulation of antibiotic resistance in Burkholderia cenocepacia.

    Science.gov (United States)

    El-Halfawy, Omar M; Valvano, Miguel A

    2014-07-01

    Communication of antibiotic resistance among bacteria via small molecules is implicated in transient reduction of bacterial susceptibility to antibiotics, which could lead to therapeutic failures aggravating the problem of antibiotic resistance. Released putrescine from the extremely antibiotic-resistant bacterium Burkholderia cenocepacia protects less-resistant cells from different species against the antimicrobial peptide polymyxin B (PmB). Exposure of B. cenocepacia to sublethal concentrations of PmB and other bactericidal antibiotics induces reactive oxygen species (ROS) production and expression of the oxidative stress response regulator OxyR. We evaluated whether putrescine alleviates antibiotic-induced oxidative stress. The accumulation of intracellular ROS, such as superoxide ion and hydrogen peroxide, was assessed fluorometrically with dichlorofluorescein diacetate, while the expression of OxyR and putrescine synthesis enzymes was determined in luciferase assays using chromosomal promoter-lux reporter system fusions. We evaluated wild-type and isogenic deletion mutant strains with defects in putrescine biosynthesis after exposure to sublethal concentrations of PmB and other bactericidal antibiotics. Exogenous putrescine protected against oxidative stress induced by PmB and other antibiotics, whereas reduced putrescine synthesis resulted in increased ROS generation and a parallel increased sensitivity to PmB. Of the 3 B. cenocepacia putrescine-synthesizing enzymes, PmB induced only BCAL2641, an ornithine decarboxylase. This study reveals BCAL2641 as a critical component of the putrescine-mediated communication of antibiotic resistance and as a plausible target for designing inhibitors that would block the communication of such resistance among different bacteria, ultimately reducing the window of therapeutic failure in treating bacterial infections. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Antibiotic treatment of biofilm infections.

    Science.gov (United States)

    Ciofu, Oana; Rojo-Molinero, Estrella; Macià, María D; Oliver, Antonio

    2017-04-01

    Bacterial biofilms are associated with a wide range of infections, from those related to exogenous devices, such as catheters or prosthetic joints, to chronic tissue infections such as those occurring in the lungs of cystic fibrosis patients. Biofilms are recalcitrant to antibiotic treatment due to multiple tolerance mechanisms (phenotypic resistance). This causes persistence of biofilm infections in spite of antibiotic exposure which predisposes to antibiotic resistance development (genetic resistance). Understanding the interplay between phenotypic and genetic resistance mechanisms acting on biofilms, as well as appreciating the diversity of environmental conditions of biofilm infections which influence the effect of antibiotics are required in order to optimize the antibiotic treatment of biofilm infections. Here, we review the current knowledge on phenotypic and genetic resistance in biofilms and describe the potential strategies for the antibiotic treatment of biofilm infections. Of note is the optimization of PK/PD parameters in biofilms, high-dose topical treatments, combined and sequential/alternate therapies or the use antibiotic adjuvants. © 2017 APMIS. Published by John Wiley & Sons Ltd.

  19. Alternatives to antibiotics for the control of bacterial disease in aquaculture.

    Science.gov (United States)

    Defoirdt, Tom; Sorgeloos, Patrick; Bossier, Peter

    2011-06-01

    The wide and frequent use of antibiotics in aquaculture has resulted in the development and spread of antibiotic resistance. Because of the health risks associated with the use of antibiotics in animal production, there is a growing awareness that antibiotics should be used with more care. This is reflected in the recent implementation of more strict regulations on the prophylactic use of antibiotics and the presence of antibiotic residues in aquaculture products. For a sustainable further development of the aquaculture industry, novel strategies to control bacterial infections are needed. This review evaluates several alternative biocontrol measures that have emerged recently. Most of these methods are still in research phase; few have been tested in real aquaculture settings. It is important to further develop different strategies that could be combined or used in rotation in order to maximise the chance of successfully protecting the animals and to prevent resistance development. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Antibiotics and the resistant microbiome

    DEFF Research Database (Denmark)

    Sommer, Morten; Dantas, Gautam

    2011-01-01

    Since the discovery and clinical application of antibiotics, pathogens and the human microbiota have faced a near continuous exposure to these selective agents. A well-established consequence of this exposure is the evolution of multidrug-resistant pathogens, which can become virtually untreatable....... Less appreciated are the concomitant changes in the human microbiome in response to these assaults and their contribution to clinical resistance problems. Studies have shown that pervasive changes to the human microbiota result from antibiotic treatment and that resistant strains can persist for years...... expand our understanding of the interplay between antibiotics and the microbiome....

  1. Antibiotic resistance: A current epilogue.

    Science.gov (United States)

    Dodds, David R

    2017-06-15

    The history of the first commercial antibiotics is briefly reviewed, together with data from the US and WHO, showing the decrease in death due to infectious diseases over the 20th century, from just under half of all deaths, to less than 10%. The second half of the 20th century saw the new use of antibiotics as growth promoters for food animals in the human diet, and the end of the 20th century and beginning of the 21st saw the beginning and rapid rise of advanced microbial resistance to antibiotics. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Antibiotics as CECs: An Overview of the Hazards Posed by Antibiotics and Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Geoffrey Ivan Scott

    2016-04-01

    Full Text Available ABSTRACTMonitoring programs have traditionally monitored legacy contaminants but are shifting focus to Contaminants of Emerging Concern (CECs. CECs present many challenges for monitoring and assessment, because measurement methods don't always exist nor have toxicological studies been fully conducted to place results in proper context. Also some CECs affect metabolic pathways to produce adverse outcomes that are not assessed through traditional toxicological evaluations. Antibiotics are CECs that pose significant environmental risks including development of both toxic effects at high doses and antibiotic resistance at doses well below the Minimum Inhibitory Concentration (MIC which kill bacteria and have been found in nearly half of all sites monitored in the US. Antimicrobial resistance has generally been attributed to the use of antibiotics in medicine for humans and livestock as well as aquaculture operations. The objective of this study was to assess the extent and magnitude of antibiotics in the environment and estimate their potential hazards in the environment. Antibiotics concentrations were measured in a number of monitoring studies which included Waste Water Treatment Plants (WWTP effluent, surface waters, sediments and biota. A number of studies reported levels of Antibiotic Resistant Microbes (ARM in surface waters and some studies found specific ARM genes (e.g. the blaM-1 gene in E. coli which may pose additional environmental risk. High levels of this gene were found to survive WWTP disinfection and accumulated in sediment at levels 100-1000 times higher than in the sewerage effluent, posing potential risks for gene transfer to other bacteria.in aquatic and marine ecosystems. Antibiotic risk assessment approaches were developed based on the use of MICs and MIC Ratios [High (Antibiotic Resistant/Low (Antibiotic Sensitive MIC] for each antibiotic indicating the range of bacterial adaptability to each antibiotic to help define the No

  3. Masculinidades em jogo na América Portuguesa: a expedição de Pero Coelho de Sousa em 1603

    Directory of Open Access Journals (Sweden)

    Mário Martins Viana Júnior

    2013-12-01

    Full Text Available Neste artigo buscamos investigar algumas das contingências, transformações e invenções acerca dos aspectos de masculinidades envoltos nas trajetórias dos indivíduos que se lançaram nas atividades de conquista e colonização das capitanias do Norte da América portuguesa, durante o final do século XVI e início do século XVII, conferindo atenção especial à capitania do Siará e à expedição do capitão mor Pero Coelho Sousa, iniciada em 1603. Para tanto, analisamos relações, expectativas e comportamentos de alguns dos homens que ocuparam os principais ofícios de Sua Majestade e desenvolveram práticas de governança no Estado do Brasil, principalmente quando deliberaram sobre os avanços pelo Rio Grande, Paraíba, Siará, Piauí e Maranhão. Sob uma matriz teórica dos estudos de gênero e de masculinidades, intentamos analisar a invenção de identidades masculinas para o contexto assinalado, problematizando os elementos de identificação e diferenciação existentes entre os homens. Metodologicamente, procedemos à investigação de fontes oficiais, a exemplo de cartas, decretos e chancelas régias, além de regimentos, autos e certidões salvaguardados tanto em equipamentos brasileiros como em instituições portuguesas. Realizamos ainda a análise de livros de crônicas e memórias de religiosos e de alguns dos próprios sujeitos que se aventuraram nas atividades de conquista.

  4. Mass spectrometry methods for predicting antibiotic resistance.

    Science.gov (United States)

    Charretier, Yannick; Schrenzel, Jacques

    2016-10-01

    Developing elaborate techniques for clinical applications can be a complicated process. Whole-cell MALDI-TOF MS revolutionized reliable microorganism identification in clinical microbiology laboratories and is now replacing phenotypic microbial identification. This technique is a generic, accurate, rapid, and cost-effective growth-based method. Antibiotic resistance keeps emerging in environmental and clinical microorganisms, leading to clinical therapeutic challenges, especially for Gram-negative bacteria. Antimicrobial susceptibility testing is used to reliably predict antimicrobial success in treating infection, but it is inherently limited by the need to isolate and grow cultures, delaying the application of appropriate therapies. Antibiotic resistance prediction by growth-independent methods is expected to reduce the turnaround time. Recently, the potential of next-generation sequencing and microarrays in predicting microbial resistance has been demonstrated, and this review evaluates the potential of MS in this field. First, technological advances are described, and the possibility of predicting antibiotic resistance by MS is then illustrated for three prototypical human pathogens: Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Clearly, MS methods can identify antimicrobial resistance mediated by horizontal gene transfers or by mutations that affect the quantity of a gene product, whereas antimicrobial resistance mediated by target mutations remains difficult to detect. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Alternatives to antibiotics to control bacterial infections: luminescent vibriosis in aquaculture as an example.

    Science.gov (United States)

    Defoirdt, Tom; Boon, Nico; Sorgeloos, Patrick; Verstraete, Willy; Bossier, Peter

    2007-10-01

    The massive (mis)use of antibiotics to control infections in aquaculture has resulted in the development of resistant strains, which have rendered antibiotic treatments ineffective. Moreover, the horizontal transfer of resistance determinants to human pathogens and the presence of antibiotic residues in aquaculture products for human consumption constitute important threats to public health. Therefore, to make the aquaculture industry more sustainable, new strategies to control infections are urgently needed.

  6. Addressing resistance to antibiotics in systematic reviews of antibiotic interventions.

    Science.gov (United States)

    Leibovici, Leonard; Paul, Mical; Garner, Paul; Sinclair, David J; Afshari, Arash; Pace, Nathan Leon; Cullum, Nicky; Williams, Hywel C; Smyth, Alan; Skoetz, Nicole; Del Mar, Chris; Schilder, Anne G M; Yahav, Dafna; Tovey, David

    2016-09-01

    Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies. This omission creates a skewed view, which emphasizes short-term efficacy and ignores the long-term consequences to the patient and other people. We offer a framework for addressing antibiotic resistance in systematic reviews. We suggest that the data on background resistance in the original trials should be reported and taken into account when interpreting results. Data on emergence of resistance (whether in the body reservoirs or in the bacteria causing infection) are important outcomes. Emergence of resistance should be taken into account when interpreting the evidence on antibiotic treatment in randomized controlled trials or systematic reviews. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Prophylactic antibiotics versus post- operative antibiotics in herniorraphy

    Directory of Open Access Journals (Sweden)

    Abedulla Khan Kayamkani

    2015-07-01

    Full Text Available Postoperative surgical site infections are a major source of illness.  Infection results in longer hospital stay and higher costs.  Uses of preoperative antibiotics have been standardized and are being used routinely in most clinical surgeries and include controversial areas like breast surgery and herniorraphy. Objective of the study is to find out the benefit of prophylactic use of antibiotics in the management of herniorraphy.This project was carried out in a multispeciality tertiary care teaching hospital from 1st-30th April in 2002. Group 1 patients were treated prophylactically half an hour before surgery with single dose of I.V. antibiotics (injection.  Ampicillin 1gm + injection.  Gentamicin 80mg. Group 2 patients were treated post surgery with capsule. Ampicillin 500mg 4 times a day for 7 days and injection. Gentamicin twice a day for first 4 days. In case of group 1 patients only one out of 20 patients (5% was infected.  Whereas in-group 2 patients 5 out of 20 patients (25% were infected. The cost of prophylactic antibiotic treatment was Rs. 25.56 per patient.  The postoperative antibiotic treatment cost was Rs. 220.4 per patient.  That means postoperative treatment is around 8.62 times costlier than prophylactic treatment.             From this study it is evident that prophylactic (preoperative treatment is better than postoperative treatment with antibiotics.

  8. Commercialisation of Innovation Products in the Real Sector of Economy

    OpenAIRE

    Firsova Svetlana G.; Makhinich Anna A.; Spirina Inna G.

    2013-01-01

    The article generalises practical experience of functioning of a domestic company in the market of Ukraine, studies effective combination of marketing and innovation activity of this company. It justifies expediency of identification of the strategy of managing innovations in the trade policy, assessment of results of marketing testing of innovation products by specific indicators. It offers methods of formation of a complex indicator of assessment of results of marketing testing of a new pro...

  9. Antibiotic-free selection in biotherapeutics: now and forever.

    Science.gov (United States)

    Mignon, Charlotte; Sodoyer, Régis; Werle, Bettina

    2015-04-03

    The continuously improving sophistication of molecular engineering techniques gives access to novel classes of bio-therapeutics and new challenges for their production in full respect of the strengthening regulations. Among these biologic agents are DNA based vaccines or gene therapy products and to a lesser extent genetically engineered live vaccines or delivery vehicles. The use of antibiotic-based selection, frequently associated with genetic manipulation of microorganism is currently undergoing a profound metamorphosis with the implementation and diversification of alternative selection means. This short review will present examples of alternatives to antibiotic selection and their context of application to highlight their ineluctable invasion of the bio-therapeutic world.

  10. Antibiotic-Free Selection in Biotherapeutics: Now and Forever

    Directory of Open Access Journals (Sweden)

    Charlotte Mignon

    2015-04-01

    Full Text Available The continuously improving sophistication of molecular engineering techniques gives access to novel classes of bio-therapeutics and new challenges for their production in full respect of the strengthening regulations. Among these biologic agents are DNA based vaccines or gene therapy products and to a lesser extent genetically engineered live vaccines or delivery vehicles. The use of antibiotic-based selection, frequently associated with genetic manipulation of microorganism is currently undergoing a profound metamorphosis with the implementation and diversification of alternative selection means. This short review will present examples of alternatives to antibiotic selection and their context of application to highlight their ineluctable invasion of the bio-therapeutic world.

  11. Antibiotic Cycling and Antibiotic Mixing: Which One Best Mitigates Antibiotic Resistance?

    Science.gov (United States)

    Peña-Miller, Rafael; Gori, Fabio; Iredell, Jonathan

    2017-01-01

    Abstract Can we exploit our burgeoning understanding of molecular evolution to slow the progress of drug resistance? One role of an infection clinician is exactly that: to foresee trajectories to resistance during antibiotic treatment and to hinder that evolutionary course. But can this be done at a hospital-wide scale? Clinicians and theoreticians tried to when they proposed two conflicting behavioral strategies that are expected to curb resistance evolution in the clinic, these are known as “antibiotic cycling” and “antibiotic mixing.” However, the accumulated data from clinical trials, now approaching 4 million patient days of treatment, is too variable for cycling or mixing to be deemed successful. The former implements the restriction and prioritization of different antibiotics at different times in hospitals in a manner said to “cycle” between them. In antibiotic mixing, appropriate antibiotics are allocated to patients but randomly. Mixing results in no correlation, in time or across patients, in the drugs used for treatment which is why theorists saw this as an optimal behavioral strategy. So while cycling and mixing were proposed as ways of controlling evolution, we show there is good reason why clinical datasets cannot choose between them: by re-examining the theoretical literature we show prior support for the theoretical optimality of mixing was misplaced. Our analysis is consistent with a pattern emerging in data: neither cycling or mixing is a priori better than the other at mitigating selection for antibiotic resistance in the clinic. Key words: antibiotic cycling, antibiotic mixing, optimal control, stochastic models. PMID:28096304

  12. Prescribing antibiotics in general practice:

    DEFF Research Database (Denmark)

    Sydenham, Rikke Vognbjerg; Pedersen, Line Bjørnskov; Plejdrup Hansen, Malene

    -2019. The hypotheses and anticipated perspectives will be discussed at the conference. Conclusion This project will contribute with solid knowledge on diagnostic approaches for management of infections in Danish general practice. The results will create a base for targeted interventions aiming to optimize diagnostic......Objectives The majority of antibiotics are prescribed from general practice. The use of broad-spectrum antibiotics increases the risk of development of bacteria resistant to antibiotic treatment. In spite of guidelines aiming to minimize the use of broad-spectrum antibiotics we see an increase....... A questionnaire comprising a discrete choice experiment will allow us to investigate the relative importance of selected factors (e.g. microbiological diagnostics, point-of-care tests, patients' expectations) in the management of infectious diseases. Results This PhD project is scheduled to be carried out in 2016...

  13. EDITORIAL THE TREASURE CALLED ANTIBIOTICS

    African Journals Online (AJOL)

    communicable diseases. (cardiovascular disease, cancer, and stroke), the average ... to control since this is one of the natural coping mechanisms for their survival. However, the majority of the acquired antibiotics resistances are promoted.

  14. Antibiotic-Resistant Gonorrhea (ARG)

    Science.gov (United States)

    ... Search Form Controls Cancel Submit Search the CDC Gonorrhea Note: Javascript is disabled or is not supported ... on Facebook Sexually Transmitted Diseases (STDs) Antibiotic-Resistant Gonorrhea Basic Information Recommend on Facebook Tweet Share Compartir ...

  15. Minocycline: far beyond an antibiotic

    National Research Council Canada - National Science Library

    Garrido‐Mesa, N; Zarzuelo, A; Gálvez, J

    2013-01-01

    Minocycline is a second‐generation, semi‐synthetic tetracycline that has been in therapeutic use for over 30 years because of its antibiotic properties against both gram‐positive and gram‐negative bacteria...

  16. Macrolide antibiotics for cystic fibrosis.

    Science.gov (United States)

    Southern, K W; Barker, P M; Solis, A

    2003-01-01

    The antibiotic treatment of chest infections which characterise cystic fibrosis (CF) has significantly improved prospects for people with CF. The nature of organisms causing these infections has restricted antibiotic choice. Pseudomonas aeruginosa, especially, is resistant to most oral antibiotics. There is evidence from the laboratory and from other disease processes that macrolide antibiotics, whilst not directly active against Pseudomonas aeruginosa, may have indirect actions against this organism. We aimed to test the hypotheses that macrolide antibiotics:(1) improve clinical status compared to placebo or another antibiotic;(2) have no unacceptable adverse effects. If benefit was demonstrated, we aimed to assess the optimal type, dose and duration of macrolide therapy. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group trials register comprising references identified from comprehensive electronic database searches, handsearching relevant journals and abstract books of conference proceedings.We contacted principal investigators known to work in the field, previous authors and pharmaceutical companies who manufacture macrolide antibiotics for unpublished or follow-up data (December 2002). Date of the most recent search of the Group's register: March 2003. Published or unpublished randomised controlled trials of macrolide antibiotics compared to placebo, another class of antibiotic or another macrolide antibiotic. Studies comparing regimens of the same macrolide antibiotic at different doses will also be included. Two reviewers independently extracted data and assessed study quality. Two groups were contacted for missing data, but these were unavailable for the review. Searches identified eleven studies, two were included in this review (101 participants). One study enrolled adults and the other children (a significant number of whom were not colonised with Pseudomonas aeruginosa). Both studies report small but significant changes in respiratory

  17. [Antibiotics and aquaculture in Chile: implications for human and animal health].

    Science.gov (United States)

    Cabello, Felipe C

    2004-08-01

    Industrial antibiotic usage in agribusinesses and aquaculture is the force that drives the evolution of antibiotic resistant bacteria that produce human and animal disease in many countries. Several studies have demonstrated that most of the industrial use of antibiotics is unnecessary, and that modernization and hygienic changes can reduce this use of antibiotics without negative economic impact. In Chile, industrial aquaculture of salmon has expanded rapidly in the last 20 years becoming a major export business. The exponential growth of this industry has been accompanied by an unrestricted heavy usage of antibiotics in the aquatic environments of lakes, rivers and the ocean, and its impact is being felt in the emergence of antibiotic-resistant bacteria around aquaculture sites and a decrease in the plancktonic diversity in the same areas. The passage of antibiotic resistance genes from aquatic bacteria to human and animal pathogens has been demonstrated, indicating that industrial use of antibiotics in aquaculture affects negatively the antibiotic therapy of human and animal bacterial infections. The Chilean situation triggers important concerns because it includes the use of fluoroquinolones in aquaculture, that are not biodegradable and are able to remain in the environment for years as well as being still effective in treating human infections. The use of large volumes of a wide spectrum of antibiotics in an aquatic environment heavily contaminated with human and animal pathogens also amplifies the opportunities for gene transfer among bacteria, facilitating the emergence of antibiotic resistance and more pathogenic bacterial recombinants. The detection of residual antibiotics in salmons marketed for human consumption that can modify the normal flora of the population also suggests the need for controls on this antibiotic usage and on the presence of residual antibiotics in aquaculture food products. This important problem of public health demands an active

  18. Chemical Countermeasures for Antibiotic Resistance

    Science.gov (United States)

    2015-01-01

    New Antibacterial Discover and Development, Lucca Italy, April 15-20, 2012. • Poster: Small Molecule Suppression of Oxacillin Resistance in MRSA...1 Award Number: W81XWH-11-2-0115 TITLE: Chemical Countermeasures for Antibiotic Resistance PRINCIPAL INVESTIGATOR: Christian Melander...Countermeasures for Antibiotic Resistance 5a. CONTRACT NUMBER W81XWH-11-2-0115 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER

  19. Antibiotic prophylaxis for abdominal hysterectomy.

    Science.gov (United States)

    Mele, G; Loizzi, P; Greco, P; Gargano, G; Varcaccio Garofalo, G; Belsanti, A

    1988-01-01

    Three different regimens of antibiotic treatment have been employed in order to evaluate their efficacy as a profilaxis for abdominal hysterectomy. Two short term administrations (Cephtriaxone and Cephamandole plus Tobramycine) and a conventional full dose treatment (Cephazoline) have been compared over a group of homogeneous patients. No significant differences, except a reduction in postoperative time spent in hospital, have been found among the groups. A reduction in urinary tract infection has also been reported with a single-dose antibiotic prophylaxis.

  20. Antibiotic resistance of Neisseria gonorrhoeae isolated from gonorrhoeae patients

    Directory of Open Access Journals (Sweden)

    Mohammad Bokaeian

    2010-06-01

    Full Text Available Background: The objective of this study was to determine antibiotic susceptibility and penicillinase production by Neisseria gonorrhoeae strains isolated from gonorrhoeae patients in Zahedan.Materials and methods: In a descriptive study during 2005-2008 years, 400 suspected patients were studied by history review, medical examination, gram staining and culture in Thayer-Martin medium. Antibiotic susceptibility and penicillinase tests of isolated strains were done by disk diffusion method and aciodometric method, respectively.Results: Cultures were positive in 77(19.2% patients. The resistanat rate against antibiotics were as follow: penicillin (79.2%, ciprofloxacin (53.2%, ceftriaxone(3.8%, spectinomycin(2.5%, cefixime(12.9%, co-trimoxazole(93.5%, tetracycline(88.3% and gentamicin(29.8%. In the meanwhile, 83.1 percent of penicillin resistant isolates produced penicillinase enzyme. Discussion: Ceftriaxone, spectinomycin and cefixime are the sole antibiotics that could be considered as selective drugs. Quinolones which were regarded as an effective group of antibiotics recently have lost their importance. Resistance against other antibiotics is rapidly developing, thus, conducting experimental tests and determination of minimum inhibitory concentration and clinical trial studies at fixed intervals can contribute to diagnosis of resistance of gonococci and rapid and successful treatment of their infections in Zahedan region.

  1. Sublethal Concentrations Of Antibiotics Cause Shift To Anaerobic Metabolism In Listeria Monocytogenes And Induce Phenotypes Linked To Antibiotic Tolerance

    DEFF Research Database (Denmark)

    Knudsen, Gitte Maegaard; Ng, Yin; Gram, Lone

    2015-01-01

    Introduction: The foodborne pathogen Listeria monocytogenes can cause the severe infection listeriosis, which have up to 20-30% mortality, but if discovered in time, it can be treated with antibiotics. Most antibiotics are bacteriostatic against L. monocytogenes. This could be due...... dehydrogenase gene lmo1634 and repression of alsA and lmo1992, which are involved in acetoin production leading to more ethanol and less acetoin production. This shift in central metabolism indicates a shift from aerobic to anaerobic metabolism, that could reduce oxidative stress and be a survival strategy...

  2. [Self-medication with antibiotics in Poland

    NARCIS (Netherlands)

    Olczak, A.; Grzesiowski, P.; Hryniewicz, W.; Haaijer-Ruskamp, F.M.

    2006-01-01

    Antibiotic resistance, the important public health threat, depends on antibiotic overuse/misuse. Self-medication with antibiotics is of serious medical concern. The aim of the study, as a part of SAR project (Self-medication with antibiotic in Europe) was to survey the incidence of this phenomenon.

  3. Assessment of antibiotic susceptibilities, genotypic characteristics ...

    African Journals Online (AJOL)

    This study was designed to evaluate the antibiotic susceptibilities, genotypic characteristics and biofilm formation abilities of antibiotic-sensitive Staphylococcus aureus KACC 13236 (SAS), multiple antibiotic-resistant S. aureus CCARM 3080 (SAR), antibiotic-sensitive Salmonella Typhimurium KCCM 40253 (STS) and ...

  4. Highly sensitive and selective colorimetric sensing of antibiotics in milk.

    Science.gov (United States)

    Zhang, Xiaofang; Zhang, Yang; Zhao, Hong; He, Yujian; Li, Xiangjun; Yuan, Zhuobin

    2013-05-17

    Antibiotics residues in foods are very harmful to human beings. Determination of antibiotics residues relies largely on the availability of adequate analytical techniques. Currently, there is an urgent need for on site and real time detection of antibiotics in food. In this work, a novel one step synthesis of gold nanoparticles (AuNPs) was proposed using pyrocatechol violet (PCV) as a reducer agent. Highly sensitive and selective colorimetric detection of four antibiotics kanamycin mono sulfate (KA), neomycin sulfate (NE), streptomycin sulfate (ST) and bleomycin sulfate (BL) was realized during the formation of AuNPs. PCV has -OH groups and these antibiotics have -OH, -NH2, -NH- groups, so there may be some special hydrogen-bonding interactions between PCV and these antibiotics. Therefore, the presence of KA, NE, ST and BL would influence the synthesis of AuNPs, then the color and state of AuNPs would change, which could be observed with the naked eye or a UV-vis spectrophotometer. Results showed that A670 was linear with the logarithm of KA concentration in the range from 1.0×10(-8) to 5.0×10(-7)M and 5.0×10(-7) to 5.5×10(-5)M. The detection limit of KA was 1.0×10(-9)M (S/N=3). The coexisting substances including 1.0×10(-5)M phenylalanine, alanine, glycerol, glucose, Mg(2+), Ca(2+), Na(+), K(+), CO3(2-), SO4(2-), NO3(-), Cl(-) and Br(-) did not affect the determination of 1.0×10(-7)M antibiotics. In particular, the proposed method could be applied successfully to the detection of antibiotics in the pretreated liquid milk products. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Antibiotic resistance and virulence genes in coliform water isolates.

    Science.gov (United States)

    Stange, C; Sidhu, J P S; Tiehm, A; Toze, S

    2016-11-01

    Widespread fecal pollution of surface water may present a major health risk and a significant pathway for dissemination of antibiotic resistance bacteria. The River Rhine is one of the longest and most important rivers in Europe and an important raw water source for drinking water production. A total of 100 coliform isolates obtained from River Rhine (Germany) were examined for their susceptibility to seven antimicrobial agents. Resistances against amoxicillin, trimethoprim/sulfamethoxazole and tetracycline were detected in 48%, 11% and 9% of isolates respectively. The antibiotic resistance could be traced back to the resistance genes blaTEM, blaSHV, ampC, sul1, sul2, dfrA1, tet(A) and tet(B). Whereby, the ampC gene represents a special case, because its presence is not inevitably linked to a phenotypic antibiotic resistance. Multiple antibiotics resistance was often accompanied by the occurrence of class 1 or 2 integrons. E. coli isolates belonging to phylogenetic groups A and B1 (commensal) were more predominant (57%) compared to B2 and D groups (43%) which are known to carry virulent genes. Additionally, six E. coli virulence genes were also detected. However, the prevalence of virulence genes in the E. coli isolates was low (not exceeding 4.3% per gene) and no diarrheagenic E. coli pathotypes were detected. This study demonstrates that surface water is an important reservoir of ARGs for a number of antibiotic classes such as sulfonamide, trimethoprim, beta-lactam-antibiotics and tetracycline. The occurrence of antibiotic resistance in coliform bacteria isolated from River Rhine provides evidence for the need to develop management strategies to limit the spread of antibiotic resistant bacteria in aquatic environment. Copyright © 2016 Elsevier GmbH. All rights reserved.

  6. Prevalence of antibiotic-resistant E. coli in retail chicken: comparing conventional, organic, kosher, and raised without antibiotics [v2; ref status: indexed, http://f1000r.es/1pu

    Directory of Open Access Journals (Sweden)

    Jack M Millman

    2013-09-01

    Full Text Available Retail poultry products are known sources of antibiotic-resistant Escherichia coli, a major human health concern. Consumers have a range of choices for poultry, including conventional, organic, kosher, and raised without antibiotics (RWA – designations that are perceived to indicate differences in quality and safety. However, whether these categories vary in the frequency of contamination with antibiotic-resistant E. coli is unknown. We examined the occurrence of antibiotic-resistant E. coli on raw chicken marketed as conventional, organic, kosher and RWA. From April – June 2012, we purchased 213 samples of raw chicken from 15 locations in the New York City metropolitan area. We screened E. coli isolates from each sample for resistance to 12 common antibiotics. Although the organic and RWA labels restrict the use of antibiotics, the frequency of antibiotic-resistant E. coli tended to be only slightly lower for RWA, and organic chicken was statistically indistinguishable from conventional products that have no restrictions. Kosher chicken had the highest frequency of antibiotic-resistant E. coli, nearly twice that of conventional products, a result that belies the historical roots of kosher as a means to ensure food safety. These results indicate that production methods influence the frequency of antibiotic-resistant E. coli on poultry products available to consumers. Future research to identify the specific practices that cause the high frequency of antibiotic-resistant E. coli in kosher chicken could promote efforts to reduce consumer exposure to this potential pathogen.

  7. Biosynthesis of the antibiotic nonribosomal peptide penicillin in baker's yeast.

    Science.gov (United States)

    Awan, Ali R; Blount, Benjamin A; Bell, David J; Shaw, William M; Ho, Jack C H; McKiernan, Robert M; Ellis, Tom

    2017-05-04

    Fungi are a valuable source of enzymatic diversity and therapeutic natural products including antibiotics. Here we engineer the baker's yeast Saccharomyces cerevisiae to produce and secrete the antibiotic penicillin, a beta-lactam nonribosomal peptide, by taking genes from a filamentous fungus and directing their efficient expression and subcellular localization. Using synthetic biology tools combined with long-read DNA sequencing, we optimize productivity by 50-fold to produce bioactive yields that allow spent S. cerevisiae growth media to have antibacterial action against Streptococcus bacteria. This work demonstrates that S. cerevisiae can be engineered to perform the complex biosynthesis of multicellular fungi, opening up the possibility of using yeast to accelerate rational engineering of nonribosomal peptide antibiotics.

  8. Use of antibiotics is associated with lower enterolactone plasma concentration

    DEFF Research Database (Denmark)

    Bolvig, Anne Katrine; Kyrø, Cecilie; Nørskov, Natalja

    2016-01-01

    Scope High enterolactone levels may have health benefits in relation to risk of noncommunicable diseases. Enterolactone is produced by the colonic microbiota after intake of lignans and treatment with antimicrobials may result in altered enterolactone production. This study investigates the assoc......Scope High enterolactone levels may have health benefits in relation to risk of noncommunicable diseases. Enterolactone is produced by the colonic microbiota after intake of lignans and treatment with antimicrobials may result in altered enterolactone production. This study investigates...... with cancer. At enrollment, participants had blood drawn and completed a food frequency questionnaire and lifestyle questionnaire. Antibiotic use was assessed as reimbursed antibiotic prescriptions up to 12 months before enrollment. Antibiotic use ≤3 months before enrollment was associated with a 41% (Δcrude...

  9. Macrolide antibiotics and the airway: antibiotic or non-antibiotic effects?

    LENUS (Irish Health Repository)

    Murphy, D M

    2010-03-01

    The macrolides are a class of antibiotics widely prescribed in infectious disease. More recently, there has been considerable interest in potential indications for these agents, in addition to their simple antibacterial indications, in a number of lung pathophysiologies.

  10. Chitin Oligosaccharide (COS Reduces Antibiotics Dose and Prevents Antibiotics-Caused Side Effects in Adolescent Idiopathic Scoliosis (AIS Patients with Spinal Fusion Surgery

    Directory of Open Access Journals (Sweden)

    Yang Qu

    2017-03-01

    Full Text Available Antibiotics are always considered for surgical site infection (SSI in adolescent idiopathic scoliosis (AIS surgery. However, the use of antibiotics often causes the antibiotic resistance of pathogens and side effects. Thus, it is necessary to explore natural products as drug candidates. Chitin Oligosaccharide (COS has anti-inflammation and anti-bacteria functions. The effects of COS on surgical infection in AIS surgery were investigated. A total of 312 AIS patients were evenly and randomly assigned into control group (CG, each patient took one-gram alternative Azithromycin/Erythromycin/Cloxacillin/Aztreonam/Ceftazidime or combined daily, experiment group (EG, each patient took 20 mg COS and half-dose antibiotics daily, and placebo group (PG, each patient took 20 mg placebo and half-dose antibiotics daily. The average follow-up was one month, and infection severity and side effects were analyzed. The effects of COS on isolated pathogens were analyzed. SSI rates were 2%, 3% and 8% for spine wounds and 1%, 2% and 7% for iliac wound in CG, EG and PG (p < 0.05, respectively. COS reduces the side effects caused by antibiotics (p < 0.05. COS improved biochemical indexes and reduced the levels of interleukin (IL-6 and tumor necrosis factor (TNF alpha. COS reduced the antibiotics dose and antibiotics-caused side effects in AIS patients with spinal fusion surgery by improving antioxidant and anti-inflammatory activities. COS should be developed as potential adjuvant for antibiotics therapies.

  11. Chitin Oligosaccharide (COS) Reduces Antibiotics Dose and Prevents Antibiotics-Caused Side Effects in Adolescent Idiopathic Scoliosis (AIS) Patients with Spinal Fusion Surgery.

    Science.gov (United States)

    Qu, Yang; Xu, Jinyu; Zhou, Haohan; Dong, Rongpeng; Kang, Mingyang; Zhao, Jianwu

    2017-03-14

    Antibiotics are always considered for surgical site infection (SSI) in adolescent idiopathic scoliosis (AIS) surgery. However, the use of antibiotics often causes the antibiotic resistance of pathogens and side effects. Thus, it is necessary to explore natural products as drug candidates. Chitin Oligosaccharide (COS) has anti-inflammation and anti-bacteria functions. The effects of COS on surgical infection in AIS surgery were investigated. A total of 312 AIS patients were evenly and randomly assigned into control group (CG, each patient took one-gram alternative Azithromycin/Erythromycin/Cloxacillin/Aztreonam/Ceftazidime or combined daily), experiment group (EG, each patient took 20 mg COS and half-dose antibiotics daily), and placebo group (PG, each patient took 20 mg placebo and half-dose antibiotics daily). The average follow-up was one month, and infection severity and side effects were analyzed. The effects of COS on isolated pathogens were analyzed. SSI rates were 2%, 3% and 8% for spine wounds and 1%, 2% and 7% for iliac wound in CG, EG and PG (p antibiotics (p antibiotics dose and antibiotics-caused side effects in AIS patients with spinal fusion surgery by improving antioxidant and anti-inflammatory activities. COS should be developed as potential adjuvant for antibiotics therapies.

  12. The effect of antibiotics on diatom communities

    Digital Repository Service at National Institute of Oceanography (India)

    DeCosta, P.M.; Anil, A.C.

    of antibiotics 21 . Antibiotic concentration in sediments tends to be comparatively high due to adsorp- tion processes 22 , and is also highly locally concentrated 21 . Antibiotic stability To test the extent of antibiotic degradation during the experiment..., the stability of penicillin, streptomycin and chloramphenicol was analysed, individually and in com- bination, in the absence and presence of autoclaved sedi- ment, collected from the study area (sandy, 83% sand). Antibiotic stability was assessed in f/2...

  13. Antibiotics: Use and misuse in pediatric dentistry

    Directory of Open Access Journals (Sweden)

    F C Peedikayil

    2011-01-01

    Full Text Available Antibiotics are commonly used in dentistry for prophylactic as well as for therapeutic purposes. Most often antibiotics are used in unwarranted situations, which may give rise to resistant bacterial strains. Dentists want to make their patients well and to prevent unpleasant complications. These desires, coupled with the belief that many oral problems are infectious, stimulate the prescribing of antibiotics. Good knowledge about the indications of antibiotics is the need of the hour in prescribing antibiotics for dental conditions.

  14. Dielectrophoretic assay of bacterial resistance to antibiotics

    Energy Technology Data Exchange (ETDEWEB)

    Johari, Juliana [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Huebner, Yvonne [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Hull, Judith C [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Dale, Jeremy W [School of Biomedical and Life Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Hughes, Michael P [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom)

    2003-07-21

    The dielectrophoretic collection spectra of antibiotic-sensitive and antibiotic-resistant strains of Staphylococcus epidermidis have been determined. These indicate that in the absence of antibiotic treatment there is a strong similarity between the dielectric properties of sensitive and resistant strains, and that there is a significant difference between the sensitive strains before and after treatment with the antibiotic streptomycin after 24 h exposure. This method offers possibilities for the assessment of bacterial resistance to antibiotics. (note)

  15. Sedimentary record of antibiotic accumulation in Minnesota Lakes.

    Science.gov (United States)

    Kerrigan, Jill F; Sandberg, Kyle D; Engstrom, Daniel R; LaPara, Timothy M; Arnold, William A

    2017-10-23

    The widespread detection of antibiotics in the environment is concerning because antibiotics are designed to be effective at small doses. The objective of this work was to quantify the accumulation rates of antibiotics used by humans and animals, spanning several major antibiotic classes (sulfonamides, tetracyclines, fluoroquinolones, and macrolides), in Minnesota lake-sediment cores. Our goal was to determine temporal trends, the major anthropogenic source to these lacustrine systems, and the importance of natural production. A historical record of usage trends for ten human and/or animal-use antibiotics (four sulfonamides, three fluoroquinolones, one macrolide, trimethoprim, and lincomycin) was faithfully captured in the sediment cores. Nine other antibiotics were not detected. Ofloxacin, trimethoprim, sulfapyridine, and sulfamethazine were detected in all of the anthropogenically-impacted studied lakes. Maximum sediment fluxes reached 20.5ngcm(-2)yr(-1) (concentration 66.1ng/g) for ofloxacin, 1.2ngcm(-2)yr(-1) (1.2ng/g) for trimethoprim, 3.3ngcm(-2)yr(-1) (11.3ng/g) for sulfapyridine, and 1.0ngcm(-2)yr(-1) (1.6ng/g) for sulfamethazine, respectively. Natural production of lincomycin may have occurred in one lake at fluxes ranging from 0.4 to 1.8ngcm(-2)yr(-1) (0.1 to 5.8ng/g). Wastewater effluent appears to be the primary source of antibiotics in the studied lakes, with lesser inputs from agricultural activities. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Interrogating the plasmidome to determine antibiotic resistance gene mobility within the swine fecal microbiota

    Science.gov (United States)

    The use of antibiotics in animal production has been highlighted as a key contributor to the increasing prevalence of antibiotic resistance in agroecosystems. Gram negative bacteria, such as the Enterobacteriaceae, are important facilitators for resistance gene dissemination in the environment and i...

  17. Shotcrete for Expedient Structural Repair

    Science.gov (United States)

    1991-12-01

    compressive strengths of 3000 psi in 8 hours). With the use of Type III cement , even higher early strengths have been...serious problem for the dry-mix process, and can lead to localized areas of too high and/or too low water / cement ratios for proper strength gains. In...environmental conditions, and (6) establishment of standard tests for rebound quantity, early strength , correct water / cement ratio , and bond

  18. Expedient Repair of Structural Facilities

    Science.gov (United States)

    1992-05-01

    in the latter case, suitable and adequate deviators and anchoring devices must . provided (Figure 67b). The external tendons can be covered with...Jara, M., Hernandez, C., Garcia, R., Robles, F., Casos Tipicos de Reparacion y Refuerzo de r d~ Concreto, First Edition, Universidad Autonoma

  19. Bactericidal Antibiotics Do Not Appear To Cause Oxidative Stress in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Feld, Louise; Knudsen, Gitte Maegaard; Gram, Lone

    2012-01-01

    Oxidative stress can be an important contributor to the lethal effect of bactericidal antibiotics in some bacteria, such as Escherichia coli and Staphylococcus aureus. Thus, despite the different target-specific actions of bactericidal antibiotics, they have a common mechanism leading to bacterial...... self-destruction by internal production of hydroxyl radicals. The purpose of the present study was to determine if a similar mechanism is involved in antibiotic killing of the infectious human pathogen, Listeria monocytogenes. We treated wild-type L. monocytogenes and oxidative stress mutants (Δsod...... and Δfri) with three different bactericidal antibiotics and found no difference in killing kinetics. In contrast, wild-type E. coli and an oxidative stress mutant (ΔsodA ΔsodB) differed significantly in their sensitivity to bactericidal antibiotics. We conclude that bactericidal antibiotics did not appear...

  20. ANTIBIOTIC COMPOUND FROM MARINE ACTINOMYCETES (Streptomyces sp A11: ISOLATION AND STRUCTURE ELUCIDATON

    Directory of Open Access Journals (Sweden)

    Rofiq Sunaryanto

    2010-07-01

    Full Text Available Purification and structure elucidation of antibiotic produced by marine actinomycetes (Streptomyces sp A11 was conducted. Production of antibiotic was carried out by liquid fermentation using yeast and peptone medium for 5 days fermentation. Purification of antibiotic was carried out by silica gel 60 (Merck, 0.063-0.200 mm column chromatography and preparative HPLC. Structure elucidation was carried out using ESI-MS, 1H NMR, 13C NMR, DEPT 13C NMR, and FTIR. This antibiotic was identified as cyclo (tyrosyl-prolyl / (C14H16N2O3. This antibiotic had biological activity to Escherichia coli ATCC 25922, Staphylococcus aureus ATCC25923, Bacillus subtilis ATCC 66923, Pseudomonas aeruginosa ATCC27853, and produced by extracellular secretion.   Keywords: antibiotic, actinomycetes, purification, structure elucidation

  1. Delayed antibiotic prescriptions for respiratory infections.

    Science.gov (United States)

    Spurling, Geoffrey Kp; Del Mar, Chris B; Dooley, Liz; Foxlee, Ruth; Farley, Rebecca

    2017-09-07

    Concerns exist regarding antibiotic prescribing for respiratory tract infections (RTIs) owing to adverse reactions, cost, and antibacterial resistance. One proposed strategy to reduce antibiotic prescribing is to provide prescriptions, but to advise delay in antibiotic use with the expectation that symptoms will resolve first. This is an update of a Cochrane Review originally published in 2007, and updated in 2010 and 2013. To evaluate the effects on clinical outcomes, antibiotic use, antibiotic resistance, and patient satisfaction of advising a delayed prescription of antibiotics in respiratory tract infections. For this 2017 update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, Issue 4, 2017), which includes the Cochrane Acute Respiratory Infection Group's Specialised Register; Ovid MEDLINE (2013 to 25 May 2017); Ovid Embase (2013 to 2017 Week 21); EBSCO CINAHL Plus (1984 to 25 May 2017); Web of Science (2013 to 25 May 2017); WHO International Clinical Trials Registry Platform (1 September 2017); and ClinicalTrials.gov (1 September 2017). Randomised controlled trials involving participants of all ages defined as having an RTI, where delayed antibiotics were compared to immediate antibiotics or no antibiotics. We defined a delayed antibiotic as advice to delay the filling of an antibiotic prescription by at least 48 hours. We considered all RTIs regardless of whether antibiotics were recommended or not. We used standard Cochrane methodological procedures. Three review authors independently extracted and collated data. We assessed the risk of bias of all included trials. We contacted trial authors to obtain missing information. For this 2017 update we added one new trial involving 405 participants with uncomplicated acute respiratory infection. Overall, this review included 11 studies with a total of 3555 participants. These 11 studies involved acute respiratory infections including acute otitis media (three studies

  2. The effects of antibiotic cycling and mixing on antibiotic resistance in intensive care units: a cluster-randomised crossover trial.

    Science.gov (United States)

    van Duijn, Pleun Joppe; Verbrugghe, Walter; Jorens, Philippe Germaine; Spöhr, Fabian; Schedler, Dirk; Deja, Maria; Rothbart, Andreas; Annane, Djillali; Lawrence, Christine; Nguyen Van, Jean-Claude; Misset, Benoit; Jereb, Matjaz; Seme, Katja; Šifrer, Franc; Tomiç, Viktorija; Estevez, Francisco; Carneiro, Jandira; Harbarth, Stephan; Eijkemans, Marinus Johannes Cornelis; Bonten, Marc

    2018-01-25

    Whether antibiotic rotation strategies reduce prevalence of antibiotic-resistant, Gram-negative bacteria in intensive care units (ICUs) has not been accurately established. We aimed to assess whether cycling of antibiotics compared with a mixing strategy (changing antibiotic to an alternative class for each consecutive patient) would reduce the prevalence of antibiotic-resistant, Gram-negative bacteria in European intensive care units (ICUs). In a cluster-randomised crossover study, we randomly assigned ICUs to use one of three antibiotic groups (third-generation or fourth-generation cephalosporins, piperacillin-tazobactam, and carbapenems) as preferred empirical treatment during 6-week periods (cycling) or to change preference after every consecutively treated patient (mixing). Computer-based randomisation of intervention and rotated antibiotic sequence was done centrally. Cycling or mixing was applied for 9 months; then, following a washout period, the alternative strategy was implemented. We defined antibiotic-resistant, Gram-negative bacteria as Enterobacteriaceae with extended-spectrum β-lactamase production or piperacillin-tazobactam resistance, and Acinetobacter spp and Pseudomonas aeruginosa with piperacillin-tazobactam or carbapenem resistance. Data were collected for all admissions during the study. The primary endpoint was average, unit-wide, monthly point prevalence of antibiotic-resistant, Gram-negative bacteria in respiratory and perineal swabs with adjustment for potential confounders. This trial is registered with ClinicalTrials.gov, number NCT01293071. Eight ICUs (from Belgium, France, Germany, Portugal, and Slovenia) were randomly assigned and patients enrolled from June 27, 2011, to Feb 16, 2014. 4069 patients were admitted during the cycling periods in total and 4707 were admitted during the mixing periods. Of these, 745 patients during cycling and 853 patients during mixing were present during the monthly point-prevalence surveys, and were

  3. Application of veterinary antibiotics in China's aquaculture industry and their potential human health risks.

    Science.gov (United States)

    Mo, Wing Yin; Chen, Zhanting; Leung, Ho Man; Leung, Anna Oi Wah

    2017-04-01

    China contributes to more than 60 % of the global aquaculture production, and its aquaculture industry has become one of the main players in food security. A large amount of antibiotics is believed to be used in fish cultivation for ensuring adequate production. The use of antibiotics as disease control agents and growth promoter in aquaculture in China has raised significant concerns recently because of the potential threats to human health. The extensive use of antibiotics in aquaculture may result in water and sediment contamination and the development of antibiotic resistance genes. In this review, the role of aquaculture in antibiotic contamination of the environment as well as the emerging concern of antibiotic resistance genes in China is discussed. Based on this review, it has been concluded that more information regarding the types and quantities of antibiotics used by Chinese fish farmers is required. Studies about the contribution of antibiotic usage in aquaculture to environmental levels in surface water, their potential risks on environment and human health, and the existence and spread of antibiotic resistance genes in aquaculture are needed.

  4. Where are all the new antibiotics? The new antibiotic paradox

    Directory of Open Access Journals (Sweden)

    JM Conly

    2005-01-01

    Full Text Available At the beginning of the 20th century, illnesses caused by infectious agents ranked among the most common causes of death in North America and, indeed, worldwide. By the middle of the century, dramatic advances in the diagnosis, management and prevention of infectious diseases had occurred, and hopes were raised that many infectious diseases would be eliminated by the end of the 20th century. Much of this success in the management of infectious diseases was related to a continuous new armamentarium of antibiotics. The discovery of penicillin by Fleming in 1928 followed by the discovery and clinical use of sulphonamides in the 1930s heralded the age of modern antibiotherapy (1,2. Penicillin came into widespread use during the early 1940s. By the 1950s, the 'golden era' of antibiotic development and use was well underway, and multiple new classes of antibiotics were introduced over the next two decades (Table 1 (3.

  5. Dissemination of antibiotic resistance genes from antibiotic producers to pathogens

    DEFF Research Database (Denmark)

    Jiang, Xinglin; Ellabaan, Mostafa M Hashim; Charusanti, Pep

    2017-01-01

    , that appear to be closely related to actinobacterial ARGs known to confer resistance against clinically important antibiotics. Furthermore, we identify two potential examples of recent horizontal transfer of actinobacterial ARGs to proteobacterial pathogens. Based on this bioinformatic evidence, we propose......It has been hypothesized that some antibiotic resistance genes (ARGs) found in pathogenic bacteria derive from antibiotic-producing actinobacteria. Here we provide bioinformatic and experimental evidence supporting this hypothesis. We identify genes in proteobacteria, including some pathogens...... and experimentally test a 'carry-back' mechanism for the transfer, involving conjugative transfer of a carrier sequence from proteobacteria to actinobacteria, recombination of the carrier sequence with the actinobacterial ARG, followed by natural transformation of proteobacteria with the carrier-sandwiched ARG. Our...

  6. Reducing Vibrio load in Artemia nauplii using antimicrobial photodynamic therapy: a promising strategy to reduce antibiotic application in shrimp larviculture

    Digital Repository Service at National Institute of Oceanography (India)

    Aparna, A.; Arshad, E.; Jasmin, C.; Pai, S.S.; BrightSingh, I.S.; Mohandas, A.; Anas, A.

    PDT is hypothesized to target microorganisms via photosensitized production of reactive oxygen species (Wainwright, 1998, 2010). It has been shown effective, in killing bacterial pathogens isolated from clinical settings (Komerik et al., 2003; O'Riordan et al.../restricted the application of antibiotics in aquaculture and multilevel monitoring of the produce for antibiotic residues prevents antibiotic-containing products from reaching consumers (Johnston and Santillo, 2002). In this backdrop, the present study proposes...

  7. Improvement in Timing of Antibiotic Administration by Using a Prophylactic Antibiotic Record Form

    Directory of Open Access Journals (Sweden)

    Sung-Ching Pan

    2008-03-01

    Conclusion: The prophylactic antibiotic form effectively decreased the inappropriate use of prophylactic antibiotics. Due to its high degree of reliability, this infection control measure can be used as a continuous monitoring system for prophylactic antibiotic use.

  8. Management Options For Reducing The Release Of Antibiotics And Antibiotic Resistance Genes To The Environment

    Science.gov (United States)

    Background: There is growing concern worldwide about the role of polluted soil and water - 77 environments in the development and dissemination of antibiotic resistance. 78 Objective: To identify management options for reducing the spread of antibiotics and 79 antibiotic resist...

  9. Occurrence and Dissipation of the Antibiotics Sulfamethoxazole, Sulfadiazine, Trimethoprim, and Enrofloxacin in the Mekong Delta, Vietnam.

    Directory of Open Access Journals (Sweden)

    Chau Nguyen Dang Giang

    Full Text Available The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews for antibiotic use. Different water sources, including surface water, groundwater and piped water (164 water samples were systematically screened for antibiotic residues. To better understand antibiotic fate under tropical conditions, the dissipation behavior of selected antibiotics in the aquatic environment was investigated for the first time in mesocosm experiments. None of the investigated antibiotics were detected in groundwater and piped water samples. Surface water, which is still often used for drinking and domestic purposes by local populations, contained median concentrations of 21 ng L-1 sulfamethoxazole (SMX, 4 ng L-1 sulfadiazine (SDZ, 17 ng L-1 trimethoprim (TRIM, and 12 ng L-1 enrofloxacin (ENRO. These concentrations were lower than the predicted no effect concentrations (PNECs and minimum inhibitory concentrations (MICs, suggesting limited antibiotic-related risk to aquatic ecosystems in the monitored systems. The dissipation half-lives of the studied antibiotics ranged from <1 to 44 days, depending on the availability of sunlight and sediment. Among the studied antibiotics TRIM was the most persistent in water systems. TRIM was not susceptible to photodegradation, while the dissipation of ENRO and SDZ was influenced by photolysis. The recorded dissipation models gave good predictions of the occurrence and concentrations of TRIM, ENRO and SDZ in surface water. In summary, the currently measured concentrations of the investigated antibiotics are unlikely to cause immediate risks

  10. Expedient Protocols for the Installation of Pyrimidine Based Privileged Templates on 2-Position of Pyrrolo[2,1-c][1,4]-benzodiazepine Nucleus Linked Through a p-phenoxyl Spacer

    Directory of Open Access Journals (Sweden)

    Anshu Agarwal

    2012-01-01

    Full Text Available Exceedingly facile single step expedient protocols based on the versatility and reactivity of corresponding intermediates : [2-(dimethylaminomethylene ketone] (5 and chalcone (6, derived from 2-(p-acetyl phenoxyl substituted analogue of pyrrolo[2,1-c][1,4]-benzodiazepine (4, have been developed to provide an easy installation of the pyrimidine based privileged templates at 2-position of pyrrolo[2,1-c][1,4]-benzodiazepine through a p-phenoxyl spacer, by utilizing the synthetic strategy depicted in schemes-1 and 2.

  11. An Expedient Study on Back-Propagation (BPN) Neural Networks for Modeling Automated Evaluation of the Answers and Progress of Deaf Students' That Possess Basic Knowledge of the English Language and Computer Skills

    Science.gov (United States)

    Vrettaros, John; Vouros, George; Drigas, Athanasios S.

    This article studies the expediency of using neural networks technology and the development of back-propagation networks (BPN) models for modeling automated evaluation of the answers and progress of deaf students' that possess basic knowledge of the English language and computer skills, within a virtual e-learning environment. The performance of the developed neural models is evaluated with the correlation factor between the neural networks' response values and the real value data as well as the percentage measurement of the error between the neural networks' estimate values and the real value data during its training process and afterwards with unknown data that weren't used in the training process.

  12. [Antibiotic resistance: A global crisis].

    Science.gov (United States)

    Alós, Juan-Ignacio

    2015-12-01

    The introduction of antibiotics into clinical practice represented one of the most important interventions for the control of infectious diseases. Antibiotics have saved millions of lives and have also brought a revolution in medicine. However, an increasing threat has deteriorated the effectiveness of these drugs, that of bacterial resistance to antibiotics, which is defined here as the ability of bacteria to survive in antibiotic concentrations that inhibit/kill others of the same species. In this review some recent and important examples of resistance in pathogens of concern for mankind are mentioned. It is explained, according to present knowledge, the process that led to the current situation in a short time, evolutionarily speaking. It begins with the resistance genes, continues with clones and genetic elements involved in the maintenance and dissemination, and ends with other factors that contribute to its spread. Possible responses to the problem are also reviewed, with special reference to the development of new antibiotics. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  13. Antibiotic Resistance in Modern World

    Directory of Open Access Journals (Sweden)

    Leyla S. Namazova-Baranova

    2017-01-01

    Full Text Available The article brings up the topic not only vital and urgent for further development of modern medical science, but also affecting the interests of mankind as a whole and of every inhabitant of the Earth in particular: that is the irrational use of antibiotics and antibiotic resistance which rate is growing rapidly. We investigate the reasons for the epidemic of antibiotic resistance and discuss in detail all the necessary measures in order to cope with this problem. The shocking data on the almost universal irrational use of antibiotics by both medical workers and parents is provided. We demonstrate the microbiome changes that follow antibacterial drugs application resulting in the development of severe chronic pediatric diseases which cause severe disability or life-threatening conditions in children with long-term results in adult age. In conclusion, we summarize the evidence-based research in phytomedicine that present the phytopreparations as a serious alternative to antibiotics in a number of clinical settings. 

  14. Multiplex biosensor immunoassays for antibiotics in the food chain

    NARCIS (Netherlands)

    Haasnoot, W.

    2009-01-01

    The use of antibiotics in food-producing animals may result in unwanted residues in food products. The main objective of the present research was to study the development and application of fast and automated multiplex surface plasmon resonance (SPR)-based biosensor immunoassays (BIAs), based on

  15. Antibiotic Resistant Salmonella And Escherichia Coli Isolated From ...

    African Journals Online (AJOL)

    Our investigation revealed that Escherichia coli and Salmonella organisms were isolated in the outbreaks. A pattern of antibiotic resistance that seems to be increasing was also found. Considering the role of chickens and its products in the human food chain in Nigeria; and the close interaction between poultry and man, ...

  16. Endodontic-periodontal locally delivered antibiotics.

    Science.gov (United States)

    Lacević, Amela; Vranić, Edina; Zulić, Irfan

    2004-02-01

    Endodontic pathology is a bacterial disease. It is well established that periapical disease is the result of bacteria, their product, and the host response to them. Periradicular disease will occur after microorganisms and their metabolic products affect the periradicular tissue. Aim of using antibiotics as part of a treatment regimen is to achieve, within the periodontal environment, a concentration of the drug that is sufficient either to kill (bactericidal) or arrest the growth (bacteriostatic) of pathogenic microorganisms. There are two possible approaches to improve the drug action: sustained and controlled drug release to reduce or eliminate side effects by improving the therapeutic index and site-specific drug delivery to minimize systemic effects. These two strategies have been explored by the association of drugs with different vehicles, either naturals or synthetics. A wide variety of specialized local delivery systems (i.e.intrapocket devices) have been designed to maintain the antibiotic in the GCF (gingival crevicular fluid) at a concentration higher than the MIC (minimum inhibitory concentration). Fibres, films, strips and microparticles made of biodegradable or non-biodegradable polymers have been reported as effective methods to administer antibacterial agents for periodontal therapy. Together with these solid devices, semisolid adhesive or non-adhesive formulations have also been proposed.

  17. [Rational use of antibiotics in hospitals].

    Science.gov (United States)

    Berild, Dag; Haug, Jon Birger

    2008-10-23

    The Norwegian antibiotic policy emphasises use of narrow-spectrum antibiotics and has been regarded as successful. We have a low occurrence of antibiotic resistance, but hospital use of antibiotics in general, and broad-spectrum antibiotics specifically, has increased substantially the last 10 years. We now see a trend towards increasing antibiotic resistance, which will inevitably lead to the same serious resistance problems in Norway as abroad. We have assessed resistance profiles for the most common human pathogens in Norway in the light of literature retrieved through a non-systematic search of PubMed and Norwegian literature on rational antibiotic use. The article emphasises pharmacodynamic and pharmacokinetic aspects, as well as ecological side effects of antibiotics and discusses rational treatment of the most common infections in Norwegian hospitals. Most research in this context is performed in settings with different antibiotic resistance patterns and attitudes towards antibiotic treatment than in Norway; few studies have focused on rational antibiotic use in Norwegian hospitals. We conclude that "old-fashioned" narrow-spectrum antibiotics can still be used in Norwegian hospitals, as there is little resistance to these agents. It is still possible to treat most infections in Norwegian hospitals with narrow-spectrum antibiotics. We encourage physicians to adhere to the Norwegian antibiotic therapy tradition.

  18. Antibiotic resistance of bacterial biofilms

    DEFF Research Database (Denmark)

    Hoiby, N.; Bjarnsholt, T.; Givskov, M.

    2010-01-01

    A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis....... Characteristically, gradients of nutrients and oxygen exist from the top to the bottom of biofilms and these gradients are associated with decreased bacterial metabolic activity and increased doubling times of the bacterial cells; it is these more or less dormant cells that are responsible for some of the tolerance...... to antibiotics. Biofilm growth is associated with an increased level of mutations as well as with quorum-sensing-regulated mechanisms. Conventional resistance mechanisms such as chromosomal beta-lactamase, upregulated efflux pumps and mutations in antibiotic target molecules in bacteria also contribute...

  19. Use of Antibiotics in Children

    DEFF Research Database (Denmark)

    Pottegård, Anton; Broe, Anne; Aabenhus, Rune

    2015-01-01

    Background: We aimed to describe the use of systemic antibiotics among children in Denmark. Methods: National data on drug use in Denmark were extracted from the Danish National Prescription Database. We used prescription data for all children in Denmark aged 0 to 11 years from January 1, 2000...... to December 31, 2012. Results: We obtained data on 5,884,301 prescriptions for systemic antibiotics issued to 1,206,107 children. The most used single substances were phenoxymethylpenicillin (45%), amoxicillin (34%) and erythromycin (6%). The highest incidence rate of antibiotic treatment episodes...... was observed among children younger than 2 at 827 per 1000 children in 2012. Incidence rates were relatively stable throughout the study period. One-year prevalences in 2012 were 485, 363 and 190 per 1000 children among children aged 0–1, 2–4 and 5–11, respectively. A gradual shift from narrow...

  20. Benchmarking inappropriate empirical antibiotic treatment.

    Science.gov (United States)

    Kariv, G; Paul, M; Shani, V; Muchtar, E; Leibovici, L

    2013-07-01

    Inappropriate empirical antibiotic treatment for severe infections is associated with increased mortality. Superfluous treatment is associated with resistance induction. We aimed to define acceptable rates of inappropriate empirical antibiotic treatment. We included all prospective cohort studies published between 1975 and 2009 reporting the proportion of appropriate and inappropriate empirical antibiotic treatment of microbiologically documented infections. Studies were identified in PubMed and in reference lists of included studies. Funnel plots were drawn using the proportion of inappropriate empirical treatment as the effect size. A pooled estimate of inappropriate empirical antibiotic treatment was calculated using a β-binomial model. Control limits were calculated with the overdispersion factor technique and 20% winsorized data. Heterogeneity was assessed through subgroup analysis for categorical moderators and meta-regression for continuous variables. Eighty-seven studies, comprising 92 study groups, with 27 628 patients met inclusion criteria. The pooled rate of inappropriate empirical antibiotic treatment was 28.6% (95% CI 25.4-31.8). Funnel plot analysis yielded a dispersed graph with only 37 (40%) studies falling within the control limits. Using the overdispersion factor technique with 20% winsorizing, 79 (86%) studies fell within the control limits. None of the clinical or methodological factors could explain the large heterogeneity observed. The funnel plot presented can be used to benchmark rates of inappropriate empirical antibiotic treatment. Based on the control limits found, at least 500 patients should be evaluated before establishing a local rate. Lower and higher than expected rates might indicate overly aggressive treatment or poor performance, respectively. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.