Elimination of Listeria inoculated in ready-to-eat carrots by combination of antimicrobial coating and γ-irradiation

International Nuclear Information System (INIS)

Turgis, Mélanie; Millette, Mathieu; Salmieri, Stéphane; Lacroix, Monique

2012-01-01

A combined treatment of an edible coating composed of trans-cinnamaldehyde (TCN; 0.5% p/p) with γ-irradiation was investigated against Listeria inoculated in peeled mini-carrots. First, the D 10 value (γ-irradiation dose required to eliminate 90% of the bacterial population) of TCN was evaluated under air. This treatment resulted in a 3.66-fold increase in relative bacterial radiosensitivity (RBR) as compared to the control without antimicrobial coating. Secondly, the shelf life of mini-carrots during 21 day of storage at 4 °C was studied. Antimicrobial coating containing TCN was assayed in combination with two irradiation doses (0.25 and 0.5 kGy). Results suggested that the inactive coating did not have any antimicrobial effect against Listeria while the coating containing TCN resulted in a 1.29 log reduction in carrots packed under air after 21 days of storage. Hence, these observations indicated that the combination of irradiation with antimicrobial coating played an important role in enhancing the radiosensitization of Listeria to γ-irradiation. - Highlights: ► Synergistic effect of essential oils and γ-radiation against food pathogens. ► Reducing any undesirable organoleptic impact due to high concentration of EOs. ► Potential in controlling food pathogens and food spoilage bacteria in food. ► Elimination of Listeria monocytogenes in the carrots during the storage.

Coping with antibiotic resistance: combining nanoparticles with antibiotics and other antimicrobial agents.

Science.gov (United States)

Allahverdiyev, Adil M; Kon, Kateryna Volodymyrivna; Abamor, Emrah Sefik; Bagirova, Malahat; Rafailovich, Miriam

2011-11-01

The worldwide escalation of bacterial resistance to conventional medical antibiotics is a serious concern for modern medicine. High prevalence of multidrug-resistant bacteria among bacteria-based infections decreases effectiveness of current treatments and causes thousands of deaths. New improvements in present methods and novel strategies are urgently needed to cope with this problem. Owing to their antibacterial activities, metallic nanoparticles represent an effective solution for overcoming bacterial resistance. However, metallic nanoparticles are toxic, which causes restrictions in their use. Recent studies have shown that combining nanoparticles with antibiotics not only reduces the toxicity of both agents towards human cells by decreasing the requirement for high dosages but also enhances their bactericidal properties. Combining antibiotics with nanoparticles also restores their ability to destroy bacteria that have acquired resistance to them. Furthermore, nanoparticles tagged with antibiotics have been shown to increase the concentration of antibiotics at the site of bacterium-antibiotic interaction, and to facilitate binding of antibiotics to bacteria. Likewise, combining nanoparticles with antimicrobial peptides and essential oils generates genuine synergy against bacterial resistance. In this article, we aim to summarize recent studies on interactions between nanoparticles and antibiotics, as well as other antibacterial agents to formulate new prospects for future studies. Based on the promising data that demonstrated the synergistic effects of antimicrobial agents with nanoparticles, we believe that this combination is a potential candidate for more research into treatments for antibiotic-resistant bacteria.

Acinetobacter baumannii: Evolution of Antimicrobial Resistance—Treatment Options

Science.gov (United States)

Doi, Yohei; Murray, Gerald L.; Peleg, Anton Y.

2015-01-01

The first decade of the 20th century witnessed a surge in the incidence of infections due to several highly antimicrobial-resistant bacteria in hospitals worldwide. Acinetobacter baumannii is one such organism that turned from an occasional respiratory pathogen into a major nosocomial pathogen. An increasing number of A. baumannii genome sequences have broadened our understanding of the genetic makeup of these bacteria and highlighted the extent of horizontal transfer of DNA. Animal models of disease combined with bacterial mutagenesis have provided some valuable insights into mechanisms of A. baumannii pathogenesis. Bacterial factors known to be important for disease include outer membrane porins, surface structures including capsule and lipopolysaccharide, enzymes such as phospholipase D, iron acquisition systems, and regulatory proteins. A. baumannii has a propensity to accumulate resistance to various groups of antimicrobial agents. In particular, carbapenem resistance has become commonplace, accounting for the majority of A. baumannii strains in many hospitals today. Carbapenem-resistant strains are often resistant to all other routinely tested agents. Treatment of carbapenem-resistant A. baumannii infection therefore involves the use of combinations of last resort agents such as colistin and tigecycline, but the efficacy and safety of these approaches are yet to be defined. Antimicrobial-resistant A. baumannii has high potential to spread among ill patients in intensive care units. Early recognition and timely implementation of appropriate infection control measures is crucial in preventing outbreaks. PMID:25643273

Antimicrobial treatments to control Listeria monocytogenes in queso fresco.

Science.gov (United States)

Lourenço, António; Kamnetz, Mary B; Gadotti, Camila; Diez-Gonzalez, Francisco

2017-06-01

Queso fresco, is a Hispanic non-fermented cheese highly susceptible to contamination with L. monocytogenes. This research was aimed to determine the effect of GRAS antimicrobial ingredients to control L. monocytogenes. Antimicrobials included caprylic acid (CA), Nisaplin ® (N, 2.5% nisin), a mixture of sodium lactate and sodium diacetate (SL/SD), Lactococcus lactis sbp. lactis DPC 3147, monolaurin, and lactic acid (LA). Batches of queso fresco curds were inoculated with 10 4  CFU/g and stored at 4 °C for three weeks. During storage the count of L. monocytogenes reached 7 to 8 Log CFU/g in control samples. Most individual antimicrobial treatments resulted in less than 1 Log CFU/g reductions in final counts, with the exception of N (0.5 g/kg) and CA (2.9 g/kg) that caused more than 3 and 5 Log CFU/g differences with controls, respectively. Mixtures of ingredients were more effective in inhibiting L. monocytogenes growth, and treatments with N and CA consistently delivered 6 Log CFU/g less counts than controls. Supplementation of 12 g/kg LA to treatments with SL/SD (3%/0.22%) caused differences of more than 4 Log CFU/g in final Listeria populations. Samples treated with the binary mixtures of N and CA (0.5 and 0.7 g/kg, respectively) were evaluated in a consumer panel (n = 67). Panelists slightly preferred control and commercial over treated samples, but all samples were in average rated between "slightly liking" and "moderately liking." These experiments indicated that combined use of antimicrobial ingredients may be an effective way to control the population of Listeria monocytogenes in queso fresco. Copyright © 2016 Elsevier Ltd. All rights reserved.

Irradiation in combined treatments and food safety

International Nuclear Information System (INIS)

Lacroix Monique; Dussault Dominic; Turgis Melanie; Salmieri Stephane; Perlette Takala; Vu Dang Khanh; Ayari Samia

2013-01-01

Irradiation combined with other processes can contribute to insuring food safety to consumers and controlling severe losses during transportation and commercialisation. We have demonstrated that using in synergy with other treatments; a lower dose could be used to eliminate pathogenic bacteria and permit a better protection of the sensorial quality and to prolong the shelf life of foods. Results indicated that some bacteria are more sensitive to irradiation under modified atmosphere (MAP) and the presence of active compound can increase the bacterial radiosensitivity by more than 4 times under air and by more than 10 times under MAP. Mild heat treatment or addition of natural antimicrobial compounds before irradiation treatment has also permitted an increase of Bacillus cereus radiosensitization. An increase of the bacterial radiosensitization of 1.5 and 1.56 was respectively observed. The effectiveness of the use of edible coating containing natural antimicrobial compounds, modified atmosphere packaging (MAP) or mild treatment before irradiation treatment was demonstrated in order to inactivate Listeria monocytogenes, Salmonella typhimurium, Escherichia coli and Bacillus cereus growth or B. cereus spore germination, to increase the bacterial sensitivity to irradiation, to reduce the water loss and to extend the shelf life of the food when stored at 4 deg C. Also, the use of edible coating previously crosslinked by irradiation have permitted a better control of the active compounds release. Studies of combined treatments were used in ready to eat vegetables, fruits and meat products. (author)

In vitro susceptibilities of zygomycetes to combinations of antimicrobial agents.

NARCIS (Netherlands)

Danaoui, E.; Afeltra, J.; Meis, J.F.G.M.; Verweij, P.E.

2002-01-01

Combinations of antimicrobial agents were tested against 35 strains of zygomycetes. The interaction between amphotericin B and rifampin was synergistic or additive. Flucytosine alone was inactive and, upon combination with amphotericin B, synergy was not achieved. The combination of amphotericin B

Fixed-dose combinations of antimicrobials: A need for special attention

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N Shafiq

2016-01-01

Full Text Available Objective: To highlight the issue of freely available fixed-dose combinations (FDCs of antimicrobials. Methods: A critique of two such antimicrobial FDCs was undertaken wherein the following aspects were assessed - rational and regulatory issues and justification for clinical use. Available in vitro, in vivo (animals and humans evidence from published literature was analysed. Conclusions: There are several inadequately addressed aspects of the considered FDCs which are available in Indian market. In view of the growing problem of antimicrobial resistance, this issue must get the required attention.

Antimicrobial activity of the imipenem/rifampicin combination against clinical isolates of Acinetobacter baumannii grown in planktonic and biofilm cultures.

Science.gov (United States)

Wang, Yang; Bao, Wanguo; Guo, Na; Chen, Haiying; Cheng, Wei; Jin, Kunqi; Shen, Fengge; Xu, Jiancheng; Zhang, Qiaoli; Wang, Chao; An, Yanan; Zhang, Kaiyu; Wang, Feng; Yu, Lu

2014-12-01

To investigate the antimicrobial activity of imipenem and rifampicin alone and in combination against clinical isolates of Acinetobacter baumannii grown in planktonic and biofilm cultures. Minimum inhibitory concentrations were determined for each isolate grown in suspension and in biofilm using a microbroth dilution method. Chequerboard assays and the agar disk diffusion assay were used to determine synergistic, indifferent or antagonistic interactions between imipenem and rifampicin. We used the tissue culture plate method for A. baumannii biofilm formation to measure the percentage of biofilm inhibition and the amount of extracellular DNA after the treatment. To understand the synergistic mechanisms, we conducted hydroxyl radical formation assays. The results were verified by confocal laser scanning microscopy. Imipenem and rifampicin showed effective antimicrobial activity against suspensions and biofilm cultures of A. baumannii, respectively. Synergistic antimicrobial effects between imipenem and rifampicin were observed in 13 and 17 of the 20 clinical isolates when in suspension and in biofilms, respectively. Imipenem and rifampicin alone and in combination generated hydroxyl radicals, which are highly reactive oxygen forms and the major components of bactericidal agents. Furthermore, treatment with imipenem and rifampicin individually or in combination has obvious antibiofilm effects. The synergistic activity of imipenem and rifampicin against clinical isolates of A. baumannii (in suspension and in biofilms) was observed in vitro. Therefore, we conclude that imipenem combined with rifampicin has the potential to be used as a combinatorial therapy for the treatment of infectious diseases caused by A. baumannii.

Antimicrobial combinations: Bliss independence and Loewe additivity derived from mechanistic multi-hit models

Science.gov (United States)

Yu, Guozhi; Hozé, Nathanaël; Rolff, Jens

2016-01-01

Antimicrobial peptides (AMPs) and antibiotics reduce the net growth rate of bacterial populations they target. It is relevant to understand if effects of multiple antimicrobials are synergistic or antagonistic, in particular for AMP responses, because naturally occurring responses involve multiple AMPs. There are several competing proposals describing how multiple types of antimicrobials add up when applied in combination, such as Loewe additivity or Bliss independence. These additivity terms are defined ad hoc from abstract principles explaining the supposed interaction between the antimicrobials. Here, we link these ad hoc combination terms to a mathematical model that represents the dynamics of antimicrobial molecules hitting targets on bacterial cells. In this multi-hit model, bacteria are killed when a certain number of targets are hit by antimicrobials. Using this bottom-up approach reveals that Bliss independence should be the model of choice if no interaction between antimicrobial molecules is expected. Loewe additivity, on the other hand, describes scenarios in which antimicrobials affect the same components of the cell, i.e. are not acting independently. While our approach idealizes the dynamics of antimicrobials, it provides a conceptual underpinning of the additivity terms. The choice of the additivity term is essential to determine synergy or antagonism of antimicrobials. This article is part of the themed issue ‘Evolutionary ecology of arthropod antimicrobial peptides’. PMID:27160596

Antimicrobial combinations: Bliss independence and Loewe additivity derived from mechanistic multi-hit models.

Science.gov (United States)

Baeder, Desiree Y; Yu, Guozhi; Hozé, Nathanaël; Rolff, Jens; Regoes, Roland R

2016-05-26

Antimicrobial peptides (AMPs) and antibiotics reduce the net growth rate of bacterial populations they target. It is relevant to understand if effects of multiple antimicrobials are synergistic or antagonistic, in particular for AMP responses, because naturally occurring responses involve multiple AMPs. There are several competing proposals describing how multiple types of antimicrobials add up when applied in combination, such as Loewe additivity or Bliss independence. These additivity terms are defined ad hoc from abstract principles explaining the supposed interaction between the antimicrobials. Here, we link these ad hoc combination terms to a mathematical model that represents the dynamics of antimicrobial molecules hitting targets on bacterial cells. In this multi-hit model, bacteria are killed when a certain number of targets are hit by antimicrobials. Using this bottom-up approach reveals that Bliss independence should be the model of choice if no interaction between antimicrobial molecules is expected. Loewe additivity, on the other hand, describes scenarios in which antimicrobials affect the same components of the cell, i.e. are not acting independently. While our approach idealizes the dynamics of antimicrobials, it provides a conceptual underpinning of the additivity terms. The choice of the additivity term is essential to determine synergy or antagonism of antimicrobials.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).

Antimicrobial and cold plasma treatments for inactivation of listeria monocytogenes on whole apple surface

Science.gov (United States)

Introduction: Produce and bacterial cell surface structure play an important role as to where and how bacteria attach to produce surfaces. The efficacy of a novel antimicrobial solution developed in our laboratory was investigated in combination with cold plasma treatments for inactivation of Liste...

In vitro antimicrobial efficacy of a fixed-dose combination of RHZE against M. tuberculosis

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Vanessa Albertina Agertt

Full Text Available ABSTRACT The use of drugs in fixed-dose combination (FDC is now recommended by the World Health Organization (WHO due to the emergence of multidrug-resistant strains of Mycobacterium tuberculosis. FDC uses different drugs against tuberculosis (TB in a single tablet for phase-intensive therapeutic intervention. This therapy aims to optimize treatment, to prevent inappropriate use of drugs, and to prevent the emergence of new resistant strains. This study aims to evaluate the susceptibility of clinical isolates of M. tuberculosis against rifampicin, isoniazid, ethambutol, and pyrazinamide. The antimicrobials were tested separately and in associations according to FDC. This was used for broth microdilution method, which was compared to the proportions method previously considered as the gold standard. In antimicrobials testing alone, several strains were resistant to one, two, or three drugs. However, when applied to association of drugs in FDC, there was no antimicrobial resistance. The results strengthen the FDC's concept, which aims to unite the four anti-TB drugs to combat bacterial resistance.

Microbiological surveillance and antimicrobial stewardship minimise ...

African Journals Online (AJOL)

Microbiological surveillance and antimicrobial stewardship minimise the need for ultrabroad-spectrum combination therapy for treatment of nosocomial infections in a trauma intensive care unit: An audit of an evidence-based empiric antimicrobial policy.

Chemical analysis of plasma-assisted antimicrobial treatment on cotton

International Nuclear Information System (INIS)

Kan, C W; Lam, Y L; Yuen, C W M; Luximon, A; Lau, K W; Chen, K S

2013-01-01

This paper explores the use of plasma treatment as a pretreatment process to assist the application of antimicrobial process on cotton fabric with good functional effect. In this paper, antimicrobial finishing agent, Microfresh Liquid Formulation 9200-200 (MF), and a binder (polyurethane dispersion, Microban Liquid Formulation R10800-0, MB) will be used for treating the cotton fabric for improving the antimicrobial property and pre-treatment of cotton fabric by plasma under atmospheric pressure will be employed to improve loading of chemical agents. The chemical analysis of the treated cotton fabric will be conducted by Fourier transform Infrared Spectroscopy.

Occurrence of antimicrobials and antimicrobial resistance genes in beef cattle storage ponds and swine treatment lagoons

International Nuclear Information System (INIS)

Zhang, Yuping; Zhang, Chiqian; Parker, David B.; Snow, Daniel D.; Zhou, Zhi; Li, Xu

2013-01-01

Livestock manure treatment and storage structures are potential environmental sources of antimicrobials and antimicrobial resistance genes (ARGs). In this study, the occurrence of antimicrobials and ARGs was investigated in the water and the sludge compartments of beef cattle storage ponds and swine lagoons. Analysis was focused on two families of antimicrobials (sulfonamide and tetracycline) and the corresponding ARGs (sul1, sul2, tetO, tetQ and tetX). Results showed that the pseudo-partitioning coefficients of tetracyclines were higher than those of sulfonamides, suggesting different distributions of these two classes of antimicrobials between water and sludge. The ARGs tested were detected in nearly all ponds and lagoons, with the highest relative abundance in sul2 at 6.3 × 10 −1 copies per 16S rRNA gene. A positive correlation was observed between total sul genes and total sulfonamides in water while the correlation was negative in sludge. No significant correlation was found between total tet genes and total tetracyclines in either water or sludge, but significant correlations were observed for certain individual tet genes. Ammonia concentrations strongly correlated with all ARGs except tetX. This study provided quantitative information on the occurrence of antimicrobials and ARGs in the liquid and solid compartments of typical manure treatment and storage structures. - Highlights: • Partitioning of antimicrobials between water and sludge is compound specific. • Antimicrobial resistance genes occurred in both water and sludge. • The ARG abundance varied more substantially in swine lagoons than in cattle ponds. • Correlations between ARGs and antimicrobials are system dependent

Occurrence of antimicrobials and antimicrobial resistance genes in beef cattle storage ponds and swine treatment lagoons

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yuping; Zhang, Chiqian [Department of Civil Engineering, University of Nebraska-Lincoln, Lincoln, NE (United States); Parker, David B. [USDA Meat Animal Research Center, Clay Center, NE (United States); Snow, Daniel D. [Water Sciences Laboratory, University of Nebraska-Lincoln, Lincoln, NE (United States); Zhou, Zhi [Department of Civil and Environmental Engineering, National University of Singapore (Singapore); Li, Xu, E-mail: xuli@unl.edu [Department of Civil Engineering, University of Nebraska-Lincoln, Lincoln, NE (United States)

2013-10-01

Livestock manure treatment and storage structures are potential environmental sources of antimicrobials and antimicrobial resistance genes (ARGs). In this study, the occurrence of antimicrobials and ARGs was investigated in the water and the sludge compartments of beef cattle storage ponds and swine lagoons. Analysis was focused on two families of antimicrobials (sulfonamide and tetracycline) and the corresponding ARGs (sul1, sul2, tetO, tetQ and tetX). Results showed that the pseudo-partitioning coefficients of tetracyclines were higher than those of sulfonamides, suggesting different distributions of these two classes of antimicrobials between water and sludge. The ARGs tested were detected in nearly all ponds and lagoons, with the highest relative abundance in sul2 at 6.3 × 10{sup −1} copies per 16S rRNA gene. A positive correlation was observed between total sul genes and total sulfonamides in water while the correlation was negative in sludge. No significant correlation was found between total tet genes and total tetracyclines in either water or sludge, but significant correlations were observed for certain individual tet genes. Ammonia concentrations strongly correlated with all ARGs except tetX. This study provided quantitative information on the occurrence of antimicrobials and ARGs in the liquid and solid compartments of typical manure treatment and storage structures. - Highlights: • Partitioning of antimicrobials between water and sludge is compound specific. • Antimicrobial resistance genes occurred in both water and sludge. • The ARG abundance varied more substantially in swine lagoons than in cattle ponds. • Correlations between ARGs and antimicrobials are system dependent.

Antimicrobial use on Canadian dairy farms.

Science.gov (United States)

Saini, V; McClure, J T; Léger, D; Dufour, S; Sheldon, A G; Scholl, D T; Barkema, H W

2012-03-01

Antimicrobial use (AMU) data are critical for formulating policies for containing antimicrobial resistance. The present study determined AMU on Canadian dairy farms and characterized variation in AMU based on herd-level factors such as milk production, somatic cell count, herd size, geographic region and housing type. Drug use data were collected on 89 dairy herds in 4 regions of Canada, Alberta, Ontario, Québec, and the Maritime provinces (Prince Edward Island, New Brunswick, and Nova Scotia) for an average of 540 d per herd. Dairy producers and farm personnel were asked to deposit empty drug containers into specially provided receptacles. Antimicrobial use was measured as antimicrobial drug use rate (ADUR), with the unit being number of animal defined-daily doses (ADD)/1,000 cow-days. Antimicrobial drug use rates were determined at farm, region, and national level. Combined ADUR of all antimicrobial classes was 14.35 ADD/1,000 cow-days nationally. National level ADUR of the 6 most commonly used antimicrobial drug classes, cephalosporins, penicillins, penicillin combinations, tetracyclines, trimethoprim-sulfonamide combinations, and lincosamides were 3.05, 2.56, 2.20, 1.83, 0.87, and 0.84 ADD/1,000 cow-days, respectively. Dairy herds in Ontario were higher users of third-generation cephalosporins (ceftiofur) than in Québec. Alberta dairy herds were higher users of tetracyclines in comparison to Maritimes. Antimicrobial drug use rate was higher via systemic route as compared with intramammary and other routes of administration (topical, oral, and intrauterine). The ADUR of antimicrobials used intramammarily was higher for clinical mastitis treatment than dry cow therapy. For dry cow therapy, penicillin ADUR was greater than ADUR of first-generation cephalosporins. For clinical mastitis treatment, ADUR of intramammary penicillin combinations was greater than ADUR of cephapirin. Herd-level milk production was positively associated with overall ADUR, ADUR of

Effect of different oral oxytetracycline treatment regimes on selection of antimicrobial resistant coliforms in nursery pigs

DEFF Research Database (Denmark)

Fresno, Ana Herrero; Zachariasen, Camilla; Norholm, Nanna

2017-01-01

A major concern derived from using antimicrobials in pig production is the development of resistance. This study aimed to assess the impact of selected combinations of oral dose and duration of treatment with oxytetracycline (OTC) on selection of tetracycline resistant (TET-R) coliforms recovered...

Combined antibacterial effects of tissue-tolerable plasma and a modern conventional liquid antiseptic on chronic wound treatment.

Science.gov (United States)

Klebes, Martin; Ulrich, Christin; Kluschke, Franziska; Patzelt, Alexa; Vandersee, Staffan; Richter, Heike; Bob, Adrienne; von Hutten, Johanna; Krediet, Jorien T; Kramer, Axel; Lademann, Jürgen; Lange-Asschenfeld, Bernhard

2015-05-01

Potential antimicrobial effects of sequential applications of tissue-tolerable plasma (TTP) and the conventional liquid antiseptic octenidine dihydrochloride (ODC) were investigated. 34 patients with chronic leg ulcers were treated with TTP, ODC or a combination of both. The bacterial colonization was measured semi-quantitatively before and immediately after treatment and changes in the microbial strains' compositions before and after antiseptic treatments were analyzed. All antiseptic procedures reduced the bacterial counts significantly. The sequential application of TTP and ODC displayed the highest antimicrobial efficacy. Me combined use of TTP and conventional antiseptics might represent the most efficient strategy for antiseptic treatment of chronic wounds. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Combination antibiotic therapy for the treatment of infective endocarditis due to enterococci.

Science.gov (United States)

Leone, Sebastiano; Noviello, Silvana; Esposito, Silvano

2016-06-01

Enterococci are common causes of infective endocarditis (IE) in both health care and community-based setting. Enterococcal IE requires bactericidal therapy for an optimal outcome. For decades, cell-wall-active antimicrobial agents (penicillins or vancomycin) in combination with aminoglycosides were the cornerstone of the treatment; however, the emergence of antibiotic resistance has significantly reduced the efficacy of these regimens. Data for this review were identified by searches of MEDLINE and references from relevant articles on antibiotic combination regimens for the treatment of enterococcal IE. Abstracts presented in scientific conferences were not searched for. New effective and safe combination treatments, including double-β-lactam and daptomycin/β-lactam combination, are proving useful for the management of IE due to enterococci.

A comparison of methods to assess the antimicrobial activity of nanoparticle combinations on bacterial cells

OpenAIRE

Bankier, Claire; Cheong, Yuen; Mahalingam, Suntharavathanan; Edirisinghe, Mohan; Ren, Guogang; Cloutman-Green, Elaine; Ciric, Lena

2018-01-01

Background Bacterial cell quantification after exposure to antimicrobial compounds varies widely throughout industry and healthcare. Numerous methods are employed to quantify these antimicrobial effects. With increasing demand for new preventative methods for disease control, we aimed to compare and assess common analytical methods used to determine antimicrobial effects of novel nanoparticle combinations on two different pathogens. Methods Plate counts of total viable cells, flow cytometry (...

Antimicrobial compounds targeting Gram-negative bacteria in food: Their mode of action and combinational effects

DEFF Research Database (Denmark)

Hyldgaard, Morten

2015-01-01

compromising food shelf-life or safety. Natural antimicrobial compounds have therefore gained increased interest as a label-friendly alternative that can be added directly to food products. Although natural antimicrobials constitute an interesting source of compounds, it is often not understood how...... they interact with bacterial cells to exert their mechanism of inhibition or killing. Furthermore, natural antimicrobials are often not potent enough as single compounds, and may cause unwanted sensory side-effects, which limit the quantities that can be applied to food. These problems might be circumvented...... by combining antimicrobials to decrease the concentrations needed without compromising their antimicrobial activity. The work described in this dissertation presents two projects concerning the mechanism of action of selected natural antimicrobial compounds primarily against Gram-negative bacteria, and two...

Use and Misuse of Antimicrobial Drugs in Poultry and Livestock: Mechanisms of Antimicrobial Resistance

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Toni Poole* and Cynthia Sheffield

2013-07-01

Full Text Available Food safety begins on the farm with management practices that contribute to an abundant, safe, and affordable food supply. To attain this goal antimicrobials have been used in all stages of food animal production in the United States and elsewhere around the world at one time or another. Among food–production animals antimicrobials are used for growth promotion, disease prophylaxis or disease treatment, and are generally administered to the entire flock or herd. Over many decades bacteria have become resistant to multiple antimicrobial classes in a cumulative manner. Bacteria exhibit a number of well characterized mechanisms of resistance to antimicrobials that include: 1 modification of the antimicrobial; 2 alteration of the drug target; 3 decreased access of drug to target; and 4 implementation of an alternative metabolic pathway not affected by the drug. The mechanisms of resistance are complex and depend on the type of bacterium involved (e.g. Gram–positive or Gram–negative and the class of drug. Some bacterial species have accumulated resistance to nearly all antimicrobial classes due to a combination of intrinsic and acquired processes. This has and will continue to lead to clinical failures of antimicrobial treatment in both human and animal medicine.

Risk Factors for Antimicrobial Resistance in Escherichia coli in Pigs Receiving Oral Antimicrobial Treatment: A Systematic Review.

Science.gov (United States)

Burow, Elke; Käsbohrer, Annemarie

2017-03-01

The aim of this literature review was to identify risk factors in addition to antimicrobial treatment for antimicrobial resistance (AMR) occurrence in commensal Escherichia coli in pigs. A variety of studies were searched in 2014 and 2015. Studies identified as potentially relevant were assessed against eligibility criteria such as observation or experiment (no review), presentation of risk factors in addition to (single dosage) antimicrobial use, risk factors for but not resulting from AMR, and the same antimicrobial used and tested. Thirteen articles (nine on observational, four on experimental studies) were finally selected as relevant. It was reported that space allowance, production size/stage, cleanliness, entry of animals and humans into herds, dosage/frequency/route of administration, time span between treatment and sampling date, herd size, distance to another farm, coldness, and season had an impact on AMR occurrence. Associations were shown by one to four studies per factor and differed in magnitude, direction, and level of significance. The risk of bias was unclear in nearly half of the information of observational studies and in most of the information from experimental studies. Further research on the effects of specific management practices is needed to develop well-founded management advice.

Insights on antimicrobial resistance, biofilms and the use of phytochemicals as new antimicrobial agents.

Science.gov (United States)

Borges, Anabela; Saavedra, Maria J; Simões, Manuel

2015-01-01

Antimicrobial resistance is one of the most serious public health problems. This is of particular concern when bacteria become resistant to various antimicrobial agents simultaneously and when they form biofilms. Consequently, therapeutic options for the treatment of infections have become limited, leading frequently to recurrent infections, treatment failure and increase of morbidity and mortality. Both, persistence and spread of antibiotic resistance, in combination with decreased effectiveness and increased toxicity of current antibiotics have emphasized the urgent need to search alternative sources of antimicrobial substances. Plants are recognized as a source of unexplored chemical structures with high therapeutic potential, including antimicrobial activity against clinically important microorganisms. Additionally, phytochemicals (plant secondary metabolites) present several advantages over synthetic molecules, including green status and different mechanisms of action from antibiotics which could help to overcome the resistance problem. In this study, an overview of the main classes of phytochemicals with antimicrobial properties and their mode of action is presented. A revision about the application of phytochemicals for biofilm prevention and control is also done. Moreover, the use of phytochemicals as scaffolds of new functional molecules to expand the antibiotics pipeline is reviewed.

A Novel Topical Combination Ointment with Antimicrobial Activity against Methicillin-Resistant Staphylococcus aureus, Gram-Negative Superbugs, Yeasts, and Dermatophytic Fungi

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Kenneth S. Thomson, B.Ag.Sc, MS, PhD

2016-01-01

Conclusions: The results of this study suggest that this combination ointment has a broad in vitro spectrum of antimicrobial activity against both more common bacterial and fungal pathogens and may be particularly useful for treatment of infections by multidrug-resistant organisms. Additional studies are warranted to investigate the full clinical utility as a therapeutic agent and also for possible infection control interventions.

An antimicrobial evaluation of plants used for the treatment of respiratory infections in rural Maputaland, KwaZulu-Natal, South Africa.

Science.gov (United States)

York, T; van Vuuren, S F; de Wet, H

2012-10-31

, with ∑FIC values of 0.34 and 0.28 respectively. Various ratios of these two plants also demonstrated a predominantly synergistic profile. Although this in vitro study supports the traditional use of some plants independently and in combination for the treatment of respiratory ailments in rural Maputaland, results demonstrate that the traditional selection of plants in higher frequency do not necessarily correlate with higher antimicrobial efficacy. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

"Salvage microbiology": detection of bacteria directly from clinical specimens following initiation of antimicrobial treatment.

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John J Farrell

Full Text Available PCR coupled with electrospray ionization mass spectrometry (ESI-MS is a diagnostic approach that has demonstrated the capacity to detect pathogenic organisms from culture negative clinical samples after antibiotic treatment has been initiated. [1] We describe the application of PCR/ESI-MS for detection of bacteria in original patient specimens that were obtained after administration of antibiotic treatment in an open investigation analysis.We prospectively identified cases of suspected bacterial infection in which cultures were not obtained until after the initiation of antimicrobial treatment. PCR/ESI-MS was performed on 76 clinical specimens that were submitted for conventional microbiology testing from 47 patients receiving antimicrobial treatment.In our series, 72% (55/76 of cultures obtained following initiation of antimicrobial treatment were non-diagnostic (45 negative cultures; and 10 respiratory specimens with normal flora (5, yeast (4, or coagulase-negative staphylococcus (1. PCR/ESR-MS detected organisms in 83% (39/47 of cases and 76% (58/76 of the specimens. Bacterial pathogens were detected by PCR/ESI-MS in 60% (27/45 of the specimens in which cultures were negative. Notably, in two cases of relapse of prosthetic knee infections in patients on chronic suppressive antibiotics, the previous organism was not recovered in tissue cultures taken during extraction of the infected knee prostheses, but was detected by PCR/ESI-MS.Molecular methods that rely on nucleic acid amplification may offer a unique advantage in the detection of pathogens collected after initiation of antimicrobial treatment and may provide an opportunity to target antimicrobial therapy and "salvage" both individual treatment regimens as well as, in select cases, institutional antimicrobial stewardship efforts.

Effects of treatment with antimicrobial agents on the human colonic microflora

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Fatemeh Rafii

2008-12-01

Full Text Available Fatemeh Rafii, John B Sutherland, Carl E CernigliaDivision of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR, USAAbstract: Antimicrobial agents are the most valuable means available for treating bacterial infections. However, the administration of therapeutic doses of antimicrobial agents to patients is a leading cause of disturbance of the normal gastrointestinal microflora. This disturbance results in diminishing the natural defense mechanisms provided by the colonic microbial ecosystem, making the host vulnerable to infection by commensal microorganisms or nosocomial pathogens. In this minireview, the impacts of antimicrobials, individually and in combinations, on the human colonic microflora are discussed.Keywords: antibiotics, intestinal bacteria

Mastitis prevention and control practices and mastitis treatment strategies associated with the consumption of (critically important) antimicrobials on dairy herds in Flanders, Belgium.

Science.gov (United States)

Stevens, M; Piepers, S; De Vliegher, S

2016-04-01

The main objectives of this study were to evaluate to what extent variations in herd-level antimicrobial consumption (AMC) can be explained by differences in management practices that are consistently effective in the prevention of (sub)clinical mastitis, on the one hand, and by differences in mastitis treatment strategies, on the other hand. Antimicrobial consumption data were obtained during 2012 and 2013 by "garbage can audits" and expressed as antimicrobial treatment incidences (ATI) for all compounds combined (total ATI) and for the critically important antimicrobials for human health separately. Data on mastitis prevention and control practices were obtained via face-to-face interviews performed during herd visits in March 2013. Some management practices and treatment strategies related to udder health were associated with the total AMC. However, the results demonstrated that implementing effective udder health management practices does not necessarily imply a low AMC and vice versa. Herds participating in a veterinary herd health management program and herds selectively drying off cows used fewer antimicrobials compared with herds not participating in such a program or applying blanket dry-cow therapy. Moreover, herds treating (some) (sub)clinical mastitis cases with intramammary homeopathic substances consumed fewer antimicrobials than herds not applying such homeopathic treatments. Besides these factors, no other direct association was found between effective udder health management practices on the one hand and AMC on the other hand. Also, the use of critically important antimicrobials was only associated with the way in which subclinical mastitis cases were treated. The latter indicates that the AMC of critically important antimicrobials is potentially driven by factors other than those included in this study such as those related to the "mindset" of the veterinarians and their farmers. Future research should therefore aim to unravel the reasoning of

Treatment practices and quantification of antimicrobial drug usage in conventional and organic dairy farms in Wisconsin.

Science.gov (United States)

Pol, M; Ruegg, P L

2007-01-01

The objective of this study was to develop a method to quantify antimicrobial drug usage and treatment practices on conventional and organic dairy farms that had been recruited to represent a broad spectrum of potential exposure to antimicrobial drugs. Data on disease prevalence and treatment practices of organic (n = 20) and conventional (n = 20) farms were obtained during a farm visit using a survey instrument. A standardized estimate of antimicrobial drug usage was developed using a defined daily dose (DDD) of selected compounds. Density of antimicrobial drug usage was expressed as the number of DDD per adult cow per year. Differences in prevalence and management of selected diseases between conventional and organic farms were identified. The overall estimated prevalence of selected diseases was greater for conventional farms compared with organic farms. Organic farmers reported use of a variety of nonantimicrobial compounds for treatment and prevention of disease. Conventional farmers reported that penicillin was the compound most commonly used for dry cow therapy and cephapirin was most commonly used for treatment of clinical mastitis. On conventional farms, the estimated overall exposure to antimicrobial drugs was 5.43 DDD per cow per year composed of 3.58 and 1.85 DDD of intramammary and parenteral antimicrobial drugs, respectively. Of total intramammary antimicrobial drug usage, treatment of clinical mastitis contributed 2.02 DDD compared with 1.56 DDD attributed to the use of dry cow therapy. Of total parenteral treatments, the distribution of exposure was 0.52 (dry cow therapy), 1.43 (clinical mastitis treatment), 0.39 (treatment of foot disease), 0.14 (treatment of respiratory disease), and 0.32 (treatment of metritis) DDD. For treatments of foot infections (0.33 DDD), respiratory infections (0.07 DDD), and metritis (0.19 DDD), the mean density of ceftiofur usage was significantly greater compared with other compounds.

Adaptive Laboratory Evolution Of Escherichia Coli Reveals Arduous Resistance Development To A Combination Of Three Novel Antimicrobial Compounds And To The Short Amp P9-4

DEFF Research Database (Denmark)

Citterio, Linda; Franzyk, Henrik; Gram, Lone

2015-01-01

Antimicrobial peptides (AMPs) were for long considered as promising new antimicrobials since resistance was not expected. However, adaptive evolution experiments have demonstrated that bacteria may indeed develop resistance also to AMPs. However, we and others hypothesize that the risk...... of resistance development decreases when two or more compounds are combined as compared to single-drug treatments. The purpose of this study was to determine if resistance could develop in Escherichia coli ATCC 25922 to the peptidomimetic HF-1002 2 and the AMPs novicidin and P9-4. The mentioned compounds were...... adaptation to 32 x MIC. This shows that resistance to novicidin and HF-1002 2, administered alone, developed more easily than it occurred in lineages exposed to the combination of three drugs. This result further supports combinatorial treatment as a way to circumvent resistance development. Surprisingly...

Antimicrobial use Guidelines for Treatment of Respiratory Tract Disease in Dogs and Cats

DEFF Research Database (Denmark)

Lappin, M. R.; Blondeau, J.; Boothe, D.

2017-01-01

Respiratory tract disease can be associated with primary or secondary bacterial infections in dogs and cats and is a common reason for use and potential misuse, improper use, and overuse of antimicrobials. There is a lack of comprehensive treatment guidelines such as those that are available...... veterinarians in making antimicrobial treatment choices for use in the management of bacterial respiratory diseases in dogs and cats....

Inhibition of Bacillus cereus and Bacillus weihenstephanensis in raw vegetables by application of washing solutions containing enterocin AS-48 alone and in combination with other antimicrobials.

Science.gov (United States)

Cobo Molinos, Antonio; Abriouel, Hikmate; Lucas López, Rosario; Ben Omar, Nabil; Valdivia, Eva; Gálvez, Antonio

2008-09-01

Enterocin AS-48 is a broad-spectrum cyclic antimicrobial peptide produced by Enterococcus faecalis. In the present study, the bacteriocin was tested alone and in combination with other antimicrobials for decontamination of Bacillus inoculated on alfalfa, soybean sprouts and green asparagus. Washing with enterocin AS-48 solutions reduced viable cell counts of Bacillus cereus and Bacillus weihenstephanensis by 1.0-1.5 and by 1.5-2.38 log units right after application of treatment, respectively. In both cases, the bacteriocin was effective in reducing the remaining viable population below detection levels during further storage of the samples at 6 degrees C, but failed to prevent regrowth in samples stored at 15 or 22 degrees C. Application of washing treatments containing enterocin AS-48 in combination with several other antimicrobials and sanitizers (cinnamic and hydrocinnamic acids, carvacrol, polyphosphoric acid, peracetic acid, hexadecylpyridinium chloride and sodium hypochlorite) greatly enhanced the bactericidal effects. The combinations of AS-48 and sodium hypochlorite, peracetic acid or hexadecylpyridinium chloride provided the best results. After application of the combined treatments on alfalfa sprouts contaminated with B. cereus or with B. weihenstephanensis, viable bacilli were not detected or remained at very low concentrations in the treated samples during a 1-week storage period at 15 degrees C. Inhibition of B. cereus by in situ produced bacteriocin was tested by cocultivation with the AS-48 producer strain E. faecalis A-48-32 inoculated on soybean sprouts. Strain A-48-32 was able to grow and produce bacteriocin on sprouts both at 15 and 22 degrees C. At 15 degrees C, growth of B. cereus was completely inhibited in the cocultures, while a much more limited effect was observed at 22 degrees C. The results obtained for washing treatments are very encouraging for the application of enterocin AS-48 in the decontamination of sprouts. Application of washing

Reduction of Salmonella on chicken meat and chicken skin by combined or sequential application of lytic bacteriophage with chemical antimicrobials.

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Sukumaran, Anuraj T; Nannapaneni, Rama; Kiess, Aaron; Sharma, Chander Shekhar

2015-08-17

The effectiveness of recently approved Salmonella lytic bacteriophage preparation (SalmoFresh™) in reducing Salmonella in vitro and on chicken breast fillets was examined in combination with lauric arginate (LAE) or cetylpyridinium chloride (CPC). In another experiment, a sequential spray application of this bacteriophage (phage) solution on Salmonella inoculated chicken skin after a 20s dip in chemical antimicrobials (LAE, CPC, peracetic acid, or chlorine) was also examined in reducing Salmonella counts on chicken skin. The application of phage in combination with CPC or LAE reduced S. Typhimurium, S. Heidelberg, and S. Enteritidis up to 5 log units in vitro at 4 °C. On chicken breast fillets, phage in combination with CPC or LAE resulted in significant (p<0.05) reductions of Salmonella ranging from 0.5 to 1.3 log CFU/g as compared to control up to 7 days of refrigerated storage. When phage was applied sequentially with chemical antimicrobials, all the treatments resulted in significant reductions of Salmonella. The application of chlorine (30 ppm) and PAA (400 ppm) followed by phage spray (10(9)PFU/ml) resulted in highest Salmonella reductions of 1.6-1.7 and 2.2-2.5l og CFU/cm(2), respectively. In conclusion, the surface applications of phage in combination with LAE or CPC significantly reduced Salmonella counts on chicken breast fillets. However, higher reductions in Salmonella counts were achieved on chicken skin by the sequential application of chemical antimicrobials followed by phage spray. The sequential application of chlorine, PAA, and phage can provide additional hurdles to reduce Salmonella on fresh poultry carcasses or cut up parts. Copyright © 2015 Elsevier B.V. All rights reserved.

Antimicrobial drug use and risk factors associated with treatment incidence and mortality in Swiss veal calves reared under improved welfare conditions.

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Lava, M; Schüpbach-Regula, G; Steiner, A; Meylan, M

2016-04-01

Ninety-one Swiss veal farms producing under a label with improved welfare standards were visited between August and December 2014 to investigate risk factors related to antimicrobial drug use and mortality. All herds consisted of own and purchased calves, with a median of 77.4% of purchased calves. The calves' mean age was 29±15days at purchasing and the fattening period lasted at average 120±28 days. The mean carcass weight was 125±12kg. A mean of 58±33 calves were fattened per farm and year, and purchased calves were bought from a mean of 20±17 farms of origin. Antimicrobial drug treatment incidence was calculated with the defined daily dose methodology. The mean treatment incidence (TIADD) was 21±15 daily doses per calf and year. The mean mortality risk was 4.1%, calves died at a mean age of 94±50 days, and the main causes of death were bovine respiratory disease (BRD, 50%) and gastro-intestinal disease (33%). Two multivariable models were constructed, for antimicrobial drug treatment incidence (53 farms) and mortality (91 farms). No quarantine, shared air space for several groups of calves, and no clinical examination upon arrival at the farm were associated with increased antimicrobial treatment incidence. Maximum group size and weight differences >100kg within a group were associated with increased mortality risk, while vaccination and beef breed were associated with decreased mortality risk. The majority of antimicrobial treatments (84.6%) were given as group treatments with oral powder fed through an automatic milk feeding system. Combination products containing chlortetracycline with tylosin and sulfadimidine or with spiramycin were used for 54.9%, and amoxicillin for 43.7% of the oral group treatments. The main indication for individual treatment was BRD (73%). The mean age at the time of treatment was 51 days, corresponding to an estimated weight of 80-100kg. Individual treatments were mainly applied through injections (88.5%), and included

Prospective study on quantitative and qualitative antimicrobial and anti-inflammatory drug use in white veal calves.

Science.gov (United States)

Pardon, Bart; Catry, Boudewijn; Dewulf, Jeroen; Persoons, Davy; Hostens, Miel; De Bleecker, Koen; Deprez, Piet

2012-04-01

To document and quantify drug use in white veal calves, an intensive livestock production system where multidrug resistance is abundantly present. Drug consumption data were prospectively collected on 15 white veal production cohorts (n = 5853 calves) in Belgium (2007-09). Treatment incidences (TIs) based on animal defined daily dose (ADD), prescribed daily dose (PDD) and used daily dose (UDD) were calculated. Risk factors were identified by linear regression. The average TI(ADD) of antimicrobial treatments was 416.8 ADD per 1000 animals at risk. Predominantly, oral group antimicrobial treatments were used (95.8%). Of the oral group antimicrobial treatments, 12% and 88% were used for prophylactic or metaphylactic indications, respectively. The main indication for group and individual drug use was respiratory disease. The most frequently used antimicrobials (group treatments) were oxytetracycline (23.7%), amoxicillin (18.5%), tylosin (17.2%) and colistin (15.2%). Deviations from the leaflet dosage recommendations were frequently encountered, with 43.7% of the group treatments underdosed (often oxytetracycline and tylosin to treat dysbacteriosis). In 33.3% of the oral antimicrobial group treatments a combination of two antimicrobial preparations was used. Smaller integrations used more antimicrobials in group treatments than larger ones (P < 0.05); an integration is defined as a company that combines all steps of the production chain by having its own feed plant and slaughterhouse and by placing its calves in veal herds owned by producers that fatten these calves for this integration on contract. Producers used higher dosages than prescribed by the veterinarian in cohorts with a single caretaker (P < 0.01). The present study provided detailed information on the intensive antimicrobial use in the white veal industry. Reduction can only be achieved by reducing the number of oral group treatments.

Treatment of Clostridium difficile infection in mice with vancomycin alone is as effective as treatment with vancomycin and metronidazole in combination

DEFF Research Database (Denmark)

Erikstrup, Lise Tornvig; Aarup, Mie; Hagemann-Madsen, Rikke

2015-01-01

OBJECTIVE: Clostridium difficile is a major cause of nosocomial infectious diarrhoea. Treatment of C. difficile infection (CDI) depends on disease severity. A combination of vancomycin and metronidazole is often recommended in severe cases. The aim of this study was to examine, in a murine model....... difficile toxins. RESULTS: None of the mice in the vancomycin-treated group died during the treatment phase compared to a mortality of 17%, 33% and 55% in the combination, metronidazole and infected control group, respectively. Mice treated with vancomycin alone or in combination with metronidazole...... of CDI, if mice treated with a combination of vancomycin and metronidazole had a better clinical outcome than mice treated with vancomycin or metronidazole alone. DESIGN: C57BL/6J mice pretreated with an antimicrobial mixture were challenged with C. difficile VPI 10463 or phosphate-buffered saline...

Assessment of Antimicrobial Treatment Strategies in Pig Production Using Mathematical Models

DEFF Research Database (Denmark)

Ahmad, Amais

strategies. Dosing factors, along with the in vivo epidemiological parameters, govern the relation between resistance and antimicrobial use. Mathematical modeling and simulation techniques have been used over the past two decades to evaluate the effect of these factors on the development of resistance......, and are considered to be powerful tools in designing treatment strategies. The overall aim of the thesis was to develop an in vivo bacterial growth model to predict and assess the effect of dosing factor on resistance growth in order to optimize treatment strategies. Specific aims were to a) estimate pharmacodynamic...... concentration (MIC). These parameters along with MIC should be taken into account when studying the effect of antimicrobials on the bacterial growth. These parameters were used as an input to the in vivo growth model of multiple bacterial strains. For almost all treatments, high resistance levels were found...

Antimicrobial treatment for early, limited Mycobacterium ulcerans infection : a randomised controlled trial

NARCIS (Netherlands)

Nienhuis, Willemien A.; Stienstra, Ymkje; Thompson, William A.; Awuah, Peter C.; Abass, K. Mohammed; Tuah, Wilson; Awua-Boateng, Nana Yaa; Ampadu, Edwin O.; Siegmund, Vera; Schouten, Jan P.; Adjei, Ohene; Bretzel, Gisela; van der Werf, Tjip S.

2010-01-01

Background Surgical debridement was the standard treatment for Mycobacterium ulcerans infection (Buruli ulcer disease) until WHO issued provisional guidelines in 2004 recommending treatment with antimicrobial drugs (streptomycin and rifampicin) in addition to surgery. These recommendations were

Study on Antimicrobial Effects of Phytotherapy in the Treatment of Children with Pyelonephritis

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Natal’ya I. Averyanova

2017-01-01

Full Text Available Background. Improvement of treatment methods and relapse prevention of pyelonephritis in children is relevant to pediatrics. The study of the antibacterial possibilities of herbal medicines (HM provoke great interest for researches . The aim of the survey was to investigate the antimicrobial properties of combined phytotherapy in vitro. Methods. Two microbiological researches were performed in vitro. One of them was conducted using the microtechnique for serial dilution-antibiotic sensitivity testing of 62 cultures (genera Escherichia, Klebsiella, Proteus and Pseudomonas, Staphylococcus, Streptococcus isolated in significantly diagnostic concentration from the urine of children in the acute phase of pyelonephritis. The antibacterial effect of RLP was detected using the microtechnique for serial dilution. To exclude the antibacterial effect of the alcohol present in the phytopreparations, a number of analogous dilutions were placed in 19.5% solution of ethyl alcohol. At the same time, the sterility of the reaction components was monitored. The second research studied the concentration changes of the microbial suspension of Escherichia coli isolated from the urine of children before the treatment onset with incubation of different concentrations of phytopreparations and at a different exposure periods. Results. Studies on the antimicrobial activity of HM in vitro demonstrated the antimicrobial effect of HM on 58% of the examined cultures. The highest drug sensitivity was revealed in the genera Klebsiella (80%, Staphylococcus (77%, and E. coli (51.5%. Studies on the concentration changes of microbial suspension of E. coli detected 100% activity of undiluted HM at a 24-hour exposure period (sample D. A significant decrease in the pathogen growth was also obtained with HM with the dilution ratio 1:1 at a 24-hour exposure period. Conclusion. The microbiological analyses demonstrated and confirmed the antibacterial characteristics of HM. 

Herd-level association between antimicrobial use and antimicrobial resistance in bovine mastitis Staphylococcus aureus isolates on Canadian dairy farms.

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Saini, V; McClure, J T; Scholl, D T; DeVries, T J; Barkema, H W

2012-04-01

Surveillance of antimicrobial use and resistance is needed to manage antimicrobial resistance in bacteria. In this study, data were collected on antimicrobial use and resistance in Staphylococcus aureus (n=562), isolated from intramammary infections and (sub)clinical mastitis cases on 89 dairy farms in 4 regions of Canada [Alberta, Ontario, Québec, and the Maritime Provinces (Prince Edward Island, Nova Scotia, and New Brunswick)]. Dairy producers were asked to deposit empty drug containers into specially provided receptacles, and antimicrobial drug use rate was calculated to quantify antimicrobial use. Minimum inhibitory concentrations were determined using the Sensititer bovine mastitis plate system (TREK Diagnostic Systems Inc., Cleveland, OH), containing antimicrobials commonly used for mastitis treatment and control. Multivariable logistic regression models were built to determine herd-level risk factors of penicillin, ampicillin, pirlimycin, penicillin-novobiocin combination, tetracycline and sulfadimethoxine resistance in Staph. aureus isolates. Intramammary administration of the penicillin-novobiocin combination for dry cow therapy was associated with penicillin and ampicillin resistance [odds ratio (OR): 2.17 and 3.10, respectively]. Systemic administration of penicillin was associated with penicillin resistance (OR: 1.63). Intramammary administration of pirlimycin for lactating cow mastitis treatment was associated with pirlimycin resistance as well (OR: 2.07). Average herd parity was associated with ampicillin and tetracycline resistance (OR: 3.88 and 0.02, respectively). Average herd size was also associated with tetracycline resistance (OR: 1.02). Dairy herds in the Maritime region had higher odds of penicillin and lower odds of ampicillin resistance than dairy herds in Québec (OR: 2.18 and 0.19, respectively). Alberta dairy herds had lower odds of ampicillin and sulfadimethoxine resistance than dairy herds in Québec (OR: 0.04 and 0.08, respectively

Antimicrobial resistance challenged with metal-based antimicrobial macromolecules.

Science.gov (United States)

Abd-El-Aziz, Alaa S; Agatemor, Christian; Etkin, Nola

2017-02-01

Antimicrobial resistance threatens the achievements of science and medicine, as it deactivates conventional antimicrobial therapeutics. Scientists respond to the threat by developing new antimicrobial platforms to prevent and treat infections from these resistant strains. Metal-based antimicrobial macromolecules are emerging as an alternative to conventional platforms because they combine multiple mechanisms of action into one platform due to the distinctive properties of metals. For example, metals interact with intracellular proteins and enzymes, and catalyse various intracellular processes. The macromolecular architecture offers a means to enhance antimicrobial activity since several antimicrobial moieties can be conjugated to the scaffold. Further, these macromolecules can be fabricated into antimicrobial materials for contact-killing medical implants, fabrics, and devices. As volatilization or leaching out of the antimicrobial moieties from the macromolecular scaffold is reduced, these medical implants, fabrics, and devices can retain their antimicrobial activity over an extended period. Recent advances demonstrate the potential of metal-based antimicrobial macromolecules as effective platforms that prevent and treat infections from resistant strains. In this review these advances are thoroughly discussed within the context of examples of metal-based antimicrobial macromolecules, their mechanisms of action and biocompatibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antimicrobial therapy for the treatment of opportunistic infections in HIV/AIDS patients: a critical appraisal

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Seddon J

2011-04-01

Full Text Available Jo Seddon1, Sanjay Bhagani21Department of Infectious Diseases, Imperial College Healthcare NHS Trust, London, UK; 2Department of Infection and Immunity, Royal Free Hospital NHS Trust, London, UKAbstract: The widespread use of antiretroviral therapy (ART has entirely changed the management of human immunodeficiency virus (HIV infection and dramatically reduced the rates of opportunistic infections (OI. However, OI continue to cause significant morbidity and mortality in both developed countries, where presentation with advanced HIV infection is common, and also in developing countries where ART is less widely available. Evidence to direct OI guidelines is partly limited by the fact that many large-scale studies date from the pre-ART era and more recent studies are sometimes poorly powered due to the falling rates of OI. Treatment of OI is now known to be as much about antimicrobials as about immune reconstitution with ART, and recent studies help guide the timing of initiation of ART in different infections. OI have also become complicated by the immune reconstitution inflammatory syndrome phenomenon which may occur once successful immune recovery begins. Trimethoprim-sulfamethoxazole has long been one of the most important antibiotics in the treatment and prevention of OI and remains paramount. It has a broad spectrum of activity against Pneumocystis jiroveci, toxoplasmosis, and bacterial infections and has an important role to play in preventing life-threatening OI. New advances in treating OI are coming from a variety of quarters: in cytomegalovirus eye disease, the use of oral rather than intravenous drugs is changing the face of therapy; in cryptococcal meningitis, improved drug formulations and combination therapy is improving clearance rates and reducing drug toxicities; and in gut disease, the possibility of rapid immune restitution with ART is replacing the need for antimicrobials against cryptosporidia and microsporidia.Keywords: HIV

Antimicrobial consumption on Austrian dairy farms: an observational study of udder disease treatments based on veterinary medication records.

Science.gov (United States)

Firth, Clair L; Käsbohrer, Annemarie; Schleicher, Corina; Fuchs, Klemens; Egger-Danner, Christa; Mayerhofer, Martin; Schobesberger, Hermann; Köfer, Josef; Obritzhauser, Walter

2017-01-01

Antimicrobial use in livestock production is an important contemporary issue, which is of public interest worldwide. Antimicrobials are not freely available to Austrian farmers and can only be administered to livestock by veterinarians, or by farmers who are trained members of the Animal Health Service. Since 2015, veterinarians have been required by law to report antimicrobials dispensed to farmers for use in food-producing animals. The study presented here went further than the statutory framework, and collected data on antimicrobials dispensed to farmers and those administered by veterinarians. Seventeen veterinary practices were enrolled in the study via convenience sampling. These veterinarians were asked to contact interested dairy farmers regarding participation in the study (respondent-driven sampling). Data were collected from veterinary practice software between 1st October 2015 and 30th September 2016. Electronic data (89.4%) were transferred via an online interface and paper records (10.6%) were entered by the authors. Antimicrobial treatments with respect to udder disease were analysed by number of defined daily doses per cow and year (nDDD vet /cow/year), based on the European Medicines Agency technical unit, Defined Daily Dose for animals (DDD vet ). Descriptive statistics and the Wilcoxon rank sum test were used to analyse the results. Antimicrobial use data from a total of 248 dairy farms were collected during the study, 232 of these farms treated cows with antibiotics; dry cow therapy was excluded from the current analysis. The mean number of DDD vet /cow/year for the antimicrobial treatment of all udder disease was 1.33 DDD vet /cow/year. Of these treatments, 0.73 DDD vet /cow/year were classed as highest priority critically important antimicrobials (HPCIAs), according to the World Health Organization (WHO) definition. The Wilcoxon rank sum test determined a statistically significant difference between the median number of DDD vet /cow/year for

Antimicrobial consumption on Austrian dairy farms: an observational study of udder disease treatments based on veterinary medication records

Directory of Open Access Journals (Sweden)

Clair L. Firth

2017-11-01

Full Text Available Background Antimicrobial use in livestock production is an important contemporary issue, which is of public interest worldwide. Antimicrobials are not freely available to Austrian farmers and can only be administered to livestock by veterinarians, or by farmers who are trained members of the Animal Health Service. Since 2015, veterinarians have been required by law to report antimicrobials dispensed to farmers for use in food-producing animals. The study presented here went further than the statutory framework, and collected data on antimicrobials dispensed to farmers and those administered by veterinarians. Methods Seventeen veterinary practices were enrolled in the study via convenience sampling. These veterinarians were asked to contact interested dairy farmers regarding participation in the study (respondent-driven sampling. Data were collected from veterinary practice software between 1st October 2015 and 30th September 2016. Electronic data (89.4% were transferred via an online interface and paper records (10.6% were entered by the authors. Antimicrobial treatments with respect to udder disease were analysed by number of defined daily doses per cow and year (nDDDvet/cow/year, based on the European Medicines Agency technical unit, Defined Daily Dose for animals (DDDvet. Descriptive statistics and the Wilcoxon rank sum test were used to analyse the results. Results Antimicrobial use data from a total of 248 dairy farms were collected during the study, 232 of these farms treated cows with antibiotics; dry cow therapy was excluded from the current analysis. The mean number of DDDvet/cow/year for the antimicrobial treatment of all udder disease was 1.33 DDDvet/cow/year. Of these treatments, 0.73 DDDvet/cow/year were classed as highest priority critically important antimicrobials (HPCIAs, according to the World Health Organization (WHO definition. The Wilcoxon rank sum test determined a statistically significant difference between the median

Antimicrobial treatment to impair expansion of abdominal aortic aneurysm (AAA)

DEFF Research Database (Denmark)

Bergqvist, David; Lindeman, Johannes H N; Lindholt, Jes S

2013-01-01

Antimicrobial treatment to attenuate expansion of abdominal aortic aneurysm has been suggested, especially with the focus on Chlamydophila. In this systematic literature review only four randomized trials were identified. In two small studies there is an indication of an effect of roxithromycin. ...

Veterinarians' attitudes toward antimicrobial use and selective dry cow treatment in the Netherlands.

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Scherpenzeel, C G M; Santman-Berends, I M G A; Lam, T J G M

2018-03-28

In the Netherlands, regulations have been in place since 2008 to reduce the overall use of antimicrobials to mitigate antimicrobial resistance. As part of these regulations, a ban on the preventive use of antimicrobials, such as applying blanket dry cow treatment, was introduced and alternative measures such as selective dry cow treatment (SDCT) were implemented. Both farmers and veterinarians play an important role in implementing these measures and have a shared responsibility with respect to prudent antimicrobial use (AMU). The attitude of Dutch dairy veterinarians toward restricted AMU and toward SDCT is unknown, but a favorable attitude toward this approach seems crucial for successful implementation. In 2015, an online questionnaire was collected from 181 veterinarians that contained questions with regard to their attitude and behavior toward reduction of AMU and toward SDCT. Descriptive statistics were used to describe the data, and multivariable logistic regression models with a logit link function were applied to evaluate potential associations between veterinarians' attitudes toward AMU and SDCT and the rationale behind their mindset, based on positive and negative aspects of reduction in AMU. The veterinarians were divided into 3 groups based on their opinion on 4 statements with regard to AMU and SDCT: veterinarians with an unfavorable, a neutral, and a favorable attitude toward reduction of AMU and toward SDCT. For the multivariable logistic regression analysis, the first 2 groups were combined and compared with the veterinarians with a favorable attitude. The general attitude of Dutch dairy veterinarians toward reduction of AMU was positive, and most expressed the belief that they can still be a good veterinarian when they prescribe less antimicrobials. Veterinarians indicated they progressively promoted SDCT beginning in 2013. Most veterinarians see the advice they provide to farmers on SDCT as the best possible approach and are convinced that their

Chemical composition and antioxidant properties of Laurus nobilis L. and Myrtus communis L. essential oils from Morocco and evaluation of their antimicrobial activity acting alone or in combined processes for food preservation.

Science.gov (United States)

Cherrat, Lamia; Espina, Laura; Bakkali, Mohammed; García-Gonzalo, Diego; Pagán, Rafael; Laglaoui, Amin

2014-04-01

This study describes the antioxidant and antimicrobial activity of Laurus nobilis L. and Myrtus communis L. essential oils (EOs). This is the first report of the synergistic antimicrobial effect of these EOs in combination with physical food preservation treatments. EOs obtained by steam distillation from aerial parts of Laurus nobilis and Myrtus communis were analysed by using gas chromatography-mass spectrometry. The main compounds were 1,8-cineole and 2-carene (L. nobilis EO); and myrtenyl acetate, 1,8-cineole and α-pinene (M. communis EO). L. nobilis EO showed higher antioxidant activity than M. communis EO in three complementary antioxidant tests. Although antimicrobial activity tests demonstrated the effectiveness of L. nobilis EO and the lack of bactericidal effect of M. communis EO, synergistic lethal effects were observed when combining each EO (0.2 µL mL(-1)) with mild heat (54°C for 10 min) or high hydrostatic pressure (175-400 MPa for 20 min). In contrast, combination of EOs with pulsed electric fields (30 kV cm(-1) for 25 pulses) showed no additional effects. This study shows the great potential of these EOs in combined treatments with mild heat and high hydrostatic pressure to obtain a higher inactivation of foodborne pathogens, which might help in the design of safe processes applied at low intensity. © 2013 Society of Chemical Industry.

Combined effect of antimicrobial coating and gamma irradiation on shelf-life extension of pre-cooked shrimp (Penaeus spp.)

International Nuclear Information System (INIS)

Ouattara, B.; Sabato, S.F.; Lacroix, M.

2001-01-01

The present study was conducted to evaluate the combined effect of low-dose gamma irradiation and antimicrobial coating on the shelf life of pre-cooked shrimp (Penaeus spp.). Antimicrobial coatings were obtained by incorporating various concentrations of thyme oil and trans-cinnamaldehyde in coating formulations prepared from soy or whey protein isolates. Coated shrimps were stored at 4±1°C under aerobic conditions and were periodically evaluated for aerobic plate counts (APCs) and Pseudomonas putida. Sensory evaluations were performed for appearance, odor, and taste using a hedonic test. Results showed that gamma irradiation and coating treatments had synergistic effects (p < = 0.05) in reducing the APCs and P. putida with at least a 12-day extension of shelf life. Without irradiation, the inhibitory effects of the coating solutions were closely related to the concentration of thyme oil and trans-cinnamaldehyde. No detrimental effects of gamma irradiation on organoleptic parameters (appearance, odor, and taste) were observed. However, incorporation of thyme oil and trans-cinnamaldehyde reduced the acceptability scores for taste and odor

Antimicrobial Resistance and Reduced Susceptibility in Clostridium difficile: Potential Consequences for Induction, Treatment, and Recurrence of C. difficile Infection

Science.gov (United States)

Baines, Simon D.; Wilcox, Mark H.

2015-01-01

Clostridium difficile infection (CDI) remains a substantial burden on healthcare systems and is likely to remain so given our reliance on antimicrobial therapies to treat bacterial infections, especially in an aging population in whom multiple co-morbidities are common. Antimicrobial agents are a key component in the aetiology of CDI, both in the establishment of the infection and also in its treatment. The purpose of this review is to summarise the role of antimicrobial agents in primary and recurrent CDI; assessing why certain antimicrobial classes may predispose to the induction of CDI according to a balance between antimicrobial activity against the gut microflora and C. difficile. Considering these aspects of CDI is important in both the prevention of the infection and in the development of new antimicrobial treatments. PMID:27025625

Oral antimicrobials increase antimicrobial resistance in porcine E. coli--a systematic review.

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Burow, E; Simoneit, C; Tenhagen, B-A; Käsbohrer, A

2014-03-01

Administration of antimicrobials to livestock increases the risk of antimicrobial resistance (AMR) in commensal bacteria. Antimicrobials in pig production are usually administered per pen via feed which implies treatment of sick alongside with healthy animals. The objective of this systematic literature review was to investigate the effect of orally administered antimicrobials on AMR in Escherichia coli of swine. Studies published in peer reviewed journals were retrieved from the international online databases ISI Web of Knowledge, PubMed, Scopus and the national electronic literature data base of Deutsches Institut für Medizinische Dokumentation und Information. The studies were assessed using the eligibility criteria English or German language, access to full paper version, defined treatment and control group (initial value or non-treatment) as well as administration and resistance testing of the same antimicrobial class. In the qualitative synthesis, only studies were included presenting the summary measures odds ratio or prevalence of resistance, the category of the applied antimicrobial and the dosage. An effect of the antimicrobial on AMR in E. coli was evaluated as an "increase", "no effect" or "decrease" if the odds or alternatively the prevalence ratio were >1.0, 1.0 or antimicrobial substance and dosage was missing in 4 and 5 of the 11 finally selected studies. The 36 identified trials were inhomogenous in usage and provision of information on sample size. Oral administration of antimicrobials increases the risk of AMR in E. coli from swine. There is however a lack of studies on the impact of dosage and longitudinal effects of treatment. The published studies have a number of issues concerning their scientific quality. More high quality research is needed to better address and quantifiy the effect of orally administered antimicrobials on AMR in swine. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparing antimicrobial exposure based on sales data

DEFF Research Database (Denmark)

Bondt, Nico; Jensen, Vibeke Frøkjær; Puister-Jansen, Linda F.

2013-01-01

with information about estimated average dosages, to make model calculations of the average number of treatment days per average animal per year, at first based on the assumption that the treatment incidence is the same in all species and production types. Secondly, the exposure in respectively animals for meat......This paper explores the possibilities of making meaningful comparisons of the veterinary use of antimicrobial agents among countries, based on national total sales data. Veterinary antimicrobial sales data on country level and animal census data in both Denmark and the Netherlands were combined...... production and dairy and other cattle (excluding veal and young beef) was estimated, assuming zero use in the dairy and other cattle, and thirdly by assuming respectively 100% oral and 100% parenteral administration. Subsequently, the outcomes of these model calculations were compared with treatment...

Addition of antimicrobial/antimold feature and antistatic treatment by electron beam

International Nuclear Information System (INIS)

Kinoshita, Shinobu

1996-01-01

A plastic which has a high insulation resistance and is apt to build up static causes an electrostatic problem during the process or other problem like an attraction of dust or small particle. Bacteria and fungus are suspended in the air by sticking to the dust/small particle/waterdrop or in the form of spore, and are apt to stick to the substance bearing the static electricity, which may lead to a microbial problem. In order to avoid these problems, an antistatic agent is mixed in a plastic so that the insulation resistance is decreased to prevent the static electricity. Also for the addition of antimicrobial/antimold feature to a plastic, a mixing-in of antimicrobial/antimold agent is adopted. However, problems still remain in the antistatic treatment, such as that an antistatic effect finally becomes invalid due to the loss of the antistatic agent after some time or the surface of the substance becomes viscous and consequently can not maintain the hardness. As to the antimicrobial/antimold treatment, a difficulty remains in selecting a suitable antimicrobial/antimold agent which must be resistant to high temperature during a mixing-in of the agent. In our test, an electron beam-induced technology (EB) by which a non-solvent resin can be hardened at room temperature and provided with a surface hardening is evaluated. An antimicrobial effect was tested by using Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. No live bacteria was observed in a bacteria solution which had been kept overnight in contact with the test film, and the result was proved to successful. As to the antimold effect, a drop of a suspension of 5 different spores including Aspergillus niger was applied to a culture medium, and it was kept in contact with the test film for culturing. On the untreated sample, a growth of the mold was observed approx. 2 weeks later, but on the test film, a growth of the mold was not observed, and the result was proved to be successful. (J.P.N.)

Active edible coating and γ-irradiation as cold combined treatments to assure the safety of broccoli florets (Brassica oleracea L.).

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Ben-Fadhel, Yosra; Saltaji, Sabrina; Khlifi, Mohamed Ali; Salmieri, Stephane; Dang Vu, Khanh; Lacroix, Monique

2017-01-16

The antimicrobial activity of essential oils (EOs), organic acid (OA) salts and natamycin, a natural antifungal produced during fermentation by the bacterium Streptomyces natalensis, was assessed against four pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium and Aspergillus niger). The Minimum Inhibitory Concentration (MIC) of each antimicrobial (AM) was assessed to determine their efficiency on tested microbial species in order to select the most efficient. Then, the interactions between different antimicrobial compounds showing the lowest MIC were determined by the checkerboard method. The most effective antimicrobial formulation showing synergistic or additive effects was then encapsulated in an alginate matrix to protect the antimicrobial efficiency during storage. The effectiveness of the formulation was then evaluated in situ using broccoli as a food model. A combined treatment of active coating and γ-irradiation (0.4 and 0.8kGy) was also done in order to evaluate the possible synergistic effect between treatments. The results of this study allowed the selection of 4 EOs, one OA salt and the natamycin as an antifungal agent exhibiting lower MIC values. The interactive antimicrobial effects between them showed that an antimicrobial formulation composed of 300ppm of lemongrass EO, 5000ppm of sodium diacetate and 80ppm of natamycin resulted in an additive effect against A. niger, E. coli and S. Typhimurium and showing synergistic effect against L. monocytogenes. Finally, in situ analyses showed a synergistic antimicrobial activity between active coating and γ-irradiation and allowed the extension of the shelf-life of ready-to-eat (RTE) broccoli during storage at 4°C. Copyright © 2016 Elsevier B.V. All rights reserved.

Antimicrobial efficacy of the combinations of Acacia nilotica, Murraya koenigii L. sprengel, Eucalyptus hybrid and Psidium guajava on primary plaque colonizers.

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Chandra Shekar, B R; Nagarajappa, Ramesh; Singh, Rupal; Thaku, Roopesh

2014-09-01

There is an urgent need for innovative strategies to combat the two most common dental diseases of mankind namely dental caries and periodontitis. The aim was to assess the antimicrobial efficacy of the double combinations of Acacia nilotica (AN), Murraya koenigii L. Sprengel (MKL), Eucalyptus hybrid and Psidium guajava on primary plaque colonizers. The plant extracts of AN, MKL. Sprengel, Eucalyptus hybrid and P. guajava were prepared using Soxhlet apparatus. The stock solutions of individual plant extracts (100 mg/ml) were prepared. Equal quantities of stock solutions were mixed to obtain six double combinations of herbal extracts. The antimicrobial efficacy testing was done against three primary plaque colonizers using agar well-diffusion method. 0.2% chlorhexidine and dimethyl sulfoxide were used as positive and as negative controls. The mean inhibition zone between the categories was compared using one-way Analysis of Variance and Tukey's post hoc test. The combination of AN and P. guajava produced the highest mean diameter of inhibition zone (21.08 mm ± 2.11) against Streptococcus mutans. The chlorhexidine produced the least inhibition zone against S. mutans (14.50 ± 2.07). The combination of AN and P. guajava produced the maximum antimicrobial efficacy against Streptococcus sanguis (19.67 ± 1.03) and Streptococcus salivarius (20.33 ± 1.86). All the combinations of plant extracts have the potential to be used as antiplaque and anticaries agents. The combinations of herbal extracts offer enhanced antimicrobial efficacy due to the synergistic effects besides slowing the development of resistance.

VECTOR THEORY AND OPTIMAL CHOICE OF ANTIMICROBIAL DRUG FOR LOCAL WOUND TREATMENT

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Boyko N. N

2016-12-01

Full Text Available Introduction. One of important problems in the field of medicine and pharmacy is an optimal choice among several alternatives. For example, the choice of drugs for treatment among several analogs, selection of excipients among analogs for development of pharmaceutical forms with optimal pharmacological, technological and economical parameters, etc.The aim of the work is to show the possibility of vector theory use for optimal choice of antimicrobial drugs for local wound treatment among analogs taking into account several criteria at the same time. Materials and methods. For our investigation we have chosen ten drugs with antimicrobial properties for local wound treatment in different pharmaceutical forms (ointment, liniment, water and glycerin solution, tincture. We have determined antibacterial activity of drugs by agar well diffusion method on six test-stain microorganisms: Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Proteus vulgaris ATCC 4636, Bacillus subtilis ATCC 6633, and Candida albicans ATCC 885-653. Well diameter was 10 mm, the volume of drug in the well was 0.27±0.02 ml, microbial burden of agar upper layer was 107 CFU/ml, and total layer height in Petri dish was 4.0±0.5 mm. In order to integrate various qualitative and quantitative parameters into one index (vector object in multidimensional factors’ space we modify these parameters to non-dimensional normalized values. For this purpose we use a desirability theory. We have chosen the following criteria for optimal choice of the drug: antimicrobial activity (integrated index of drug’s antimicrobial activity, drug’s price, pharmacological and technological index, spectrum of drug’s action on test strains of microorganisms studied. Results and their discussions. Using vector and desirability theory, we have obtained the following range of drugs in decreasing order: Laevomecol ointment, Ioddicerinum, Tincture of Sophora

The Antimicrobial Photodynamic Therapy in the Treatment of Peri-Implantitis

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Umberto Romeo

2016-01-01

Full Text Available Introduction. The aim of this study is to demonstrate the effectiveness of addition of the antimicrobial photodynamic therapy to the conventional approach in the treatment of peri-implantitis. Materials and Methods. Forty patients were randomly assigned to test or control groups. Patients were assessed at baseline and at six (T1, twelve (T2, and twenty-four (T3 weeks recording plaque index (PlI, probing pocket depth (PPD, and bleeding on probing (BOP; control group received conventional periodontal therapy, while test group received photodynamic therapy in addition to it. Result. Test group showed a 70% reduction in the plaque index values and a 60% reduction in PD values compared to the baseline. BOP and suppuration were not detectable. Control group showed a significative reduction in plaque index and PD. Discussion. Laser therapy has some advantages in comparison to traditional therapy, with faster and greater healing of the wound. Conclusion. Test group showed after 24 weeks a better value in terms of PPD, BOP, and PlI, with an average pocket depth value of 2 mm, if compared with control group (3 mm. Our results suggest that antimicrobial photodynamic therapy with diode laser and phenothiazine chloride represents a reliable adjunctive treatment to conventional therapy. Photodynamic therapy should, however, be considered a coadjuvant in the treatment of peri-implantitis associated with mechanical (scaling and surgical (grafts treatments.

A combination of grapefruit seed extract and concentrated cranberry juice as a potential antimicrobial preservative for the improvement of microbiological stability of hypromellose gel.

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Bernatoniene, Jurga; Keraitė, Rasa; Masteiková, Ruta; Pavilonis, Alvydas; Savickas, Arūnas

2013-10-01

Aqueous hypromellose gels are not microbiologically stable - they show signs of microorganism growth during storage. To extend the shelf-life of the gels, antimicrobial preservatives are needed. Some substances of plant origin are known for their antimicrobial properties, and thus they may be used as an alternative to synthetic preservatives. Therefore, the aim of this study was to evaluate the microbiological stability of aqueous hypromellose gel and the effectiveness of natural substances - grapefruit seed extract (GSE), concentrated cranberry juice, and a combination thereof - on the antimicrobial protection of the gel. The evaluation of the antimicrobial activity of GSE and cranberry juice showed that their antimicrobial effects differed. Both cranberry juice and GSE inhibited the growth of the standard gram-positive and gram-negative bacteria, but the effect of GSE was significantly stronger. Candida albicans was sensitive only to GSE. For this reason, in order to affect all the microorganisms studied, either a combination of 0.7% GSE and 10% cranberry juice, or 5% GSE alone may be used. The combination of GSE and cranberry juice was effective only in acidic medium (pH being 2.5-5), while the antimicrobial effect of GSE was not dependent on the pH value.

Antistaphylococcal effect of enterocin AS-48 in bakery ingredients of vegetable origin, alone and in combination with selected antimicrobials.

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Viedma, Pilar Martinez; Abriouel, Hikmate; Omar, Nabil Ben; López, Rosario Lucas; Gálvez, Antonio

2009-09-01

The inhibitory effect of enterocin AS-48 against Staphylococcus aureus was investigated in various types of bakery ingredients. Antibacterial activity greatly depended on the food substrate, ranging from complete inactivation of S. aureus in liquid caramel (in which the bacterium survived poorly) to no significant inhibition (as in vanilla or chocolate creams). Significant reductions of viable counts in the range of 1.8 to 2.7 log units (P enterocin AS-48 was tested in combination with other antimicrobials. Bactericidal activity increased markedly for the combinations of AS-48 and 0.1% eugenol (v/v), 0.5% 2-nitropropanol (v/v), or 3% Nisaplin (w/v). Enterocin AS-48 could be applied in combination with other antimicrobials for preservation of bakery ingredients against S. aureus.

In vitro and in vivo analysis of antimicrobial agents alone and in combination against multi-drug resistant Acinetobacter baumannii

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Songzhe eHE

2015-05-01

Full Text Available Objective To investigate the in vitro and in vivo antibacterial activities of tigecycline and other 13 common antimicrobial agents, alone or in combination, against multi-drug resistant Acinetobacter baumannii.MethodsAn in vitro susceptibility test of 101 Acinetobacter baumannii was used to detect minimal inhibitory concentrations (MICs. A mouse lung infection model of multi-drug resistant Acinetobacter baumannii,established by the ultrasonic atomization method, was used to define in vivo antimicrobial activities.Results Multi-drug resistant Acinetobacter baumannii showed high sensitivity to tigecycline (98% inhibition, polymyxin B (78.2% inhibition, and minocycline (74.2% inhibition. However, the use of these antimicrobial agents in combination with other antimicrobial agents produced synergistic or additive effects. In vivo data showed that white blood cell (WBC counts in drug combination groups C (minocycline + amikacin and D (minocycline + rifampicin were significantly higher than in groups A (tigecycline and B (polymyxin B (P < 0.05, after administration of the drugs 24h post-infection. Lung tissue inflammation gradually increased in the model group during the first 24h after ultrasonic atomization infection; vasodilation, congestion with hemorrhage were observed 48h post infection. After three days of anti-infective therapy in groups A, B, C and D, lung tissue inflammation in each group gradually recovered with clear structures. The mortality rates in drug combination groups (groups C and D were much lower than in groups A and B.ConclusionThe combination of minocycline with either rifampicin or amikacin is more effective against multidrug-resistant Acinetobacter baumannii than single-agent tigecycline or polymyxin B. In addition, the mouse lung infection by ultrasonic atomization is a suitable model for drug screening and analysis of infection mechanism.

Effects of Plant-Derived Extracts, Other Antimicrobials, and Their Combinations against Escherichia coli O157:H7 in Beef Systems.

Science.gov (United States)

Ko, Kyung Yuk; Geornaras, Ifigenia; Paik, Hyun-Dong; Kim, Kee-Tae; Sofos, John N

2015-06-01

The antimicrobial effects of thyme oil (TO), grapefruit seed extract (GSE), and basil essential oil, alone or in combination with cetylpyridinium chloride (CPC), sodium diacetate, or lactic acid, were evaluated against Escherichia coli O157:H7 in a moisture-enhanced beef model system. The model system was composed of a nonsterile beef homogenate to which NaCl (0.5%) and sodium tripolyphosphate (0.25%) were added, together with the tested antimicrobial ingredients. Beef homogenate treatments were inoculated (ca. 3 log CFU/ml) with rifampin-resistant E. coli O157:H7 (eight-strain mixture) and incubated at 15 °C (48 h). The most effective individual treatments were TO (0.25 or 0.5%) and GSE (0.5 or 1.0%), which immediately reduced (P extracts with CPC (0.02 or 0.04%) and sodium diacetate (0.25%) had an additive effect with respect to antibacterial activity. In a second study, antimicrobial interventions were evaluated for their efficacy in reducing surface contamination of E. coli O157:H7 on beef cuts and to determine the effect of these surface treatments on subsequent internalization of the pathogen during blade tenderization. Beef cuts (10 by 8 by 3.5 cm) were inoculated (ca. 4 log CFU/g) on one side with the rifampin-resistant E. coli O157:H7 strain mixture and were then spray treated (20 lb/in(2), 10 s) with water, GSE (5 and 10%), lactic acid (5%), or CPC (5%). Untreated (control) and spray-treated surfaces were then subjected to double-pass blade tenderization. Surface contamination (4.4 log CFU/g) of E. coli O157:H7 was reduced (P < 0.05) to 3.4 (5% CPC) to 4.1 (water or 5% GSE) log CFU/g following spray treatment. The highest and lowest transfer rates of pathogen cells from the surface to deeper tissues of blade-tenderized sections were obtained in the untreated control and CPC-treated samples, respectively.

Antimicrobial activity of southern African medicinal plants with dermatological relevance: From an ethnopharmacological screening approach, to combination studies and the isolation of a bioactive compound.

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Mabona, Unathi; Viljoen, Alvaro; Shikanga, Emmanual; Marston, Andrew; Van Vuuren, Sandy

2013-06-21

Ethnobotanical reports on more than 100 southern African medicinal plants with dermatological relevance have been highlighted, yet there is still limited scientific data to support claims for their antimicrobial effectiveness against skin pathogens. Guided by ethnobotanical data, this paper explores the antimicrobial efficacies of southern African medicinal plants used to treat skin ailments. To investigate the antimicrobial properties of southern African medicinal plants against dermatologically relevant pathogens. The study also aimed at providing a scientific rationale for the traditional use of plant combinations to treat skin diseases and the isolation of the bio-active compound from the most active species, Aristea ecklonii (Iridaceae). Organic and aqueous extracts (132) were prepared from 47 plant species and screened for antimicrobial properties against dermatologically relevant pathogens using the micro-titre plate dilution method. Four different plant combinations were investigated for interactive properties and the sum of the fractional inhibitory concentration (ƩFIC) calculated. Isobolograms were used to further investigate the antimicrobial interactive properties of Pentanisia prunelloides combined with Elephantorrhiza elephantina at varied ratios. A bioactivity-guided fractionation process was adopted to fractionate the organic leaf extract of Aristea ecklonii. Plants demonstrating notable broad-spectrum activities (MIC values ≤1.00mg/ml) against the tested pathogens included extracts from Aristea ecklonii, Chenopodium ambrosioides, Diospyros mespiliformis, Elephantorrhiza elephantina, Eucalyptus camaldulensis, Gunnera perpensa, Harpephyllum caffrum, Hypericum perforatum, Melianthus comosus, Terminalia sericea and Warburgia salutaris. The organic extract of Elephantorrhiza elephantina, a plant reportedly used to treat acne vulgaris, demonstrated noteworthy antimicrobial activity (MIC value of 0.05mg/ml) against Propionibacterium acnes. Similarly

Rationality of Antimicrobial Prescriptions in Community Pharmacy Users.

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Sara I V C Lima

Full Text Available Although there is a conflict between the treatment benefits for a single individual and society, restrictions on antibiotic use are needed to reduce the prevalence of resistance to these drugs, which is the main result of irrational use. Brazil, cataloged as a pharmemerging market, has implemented restrictive measures for the consumption of antibiotics. The objective of this study was to investigate the quality of antimicrobial prescriptions and user knowledge of their treatment with these drugs.A two-stage cross-sectional, combined and stratified survey of pharmacy users holding an antimicrobial prescription was conducted in the community between May and November 2014. A pharmacist analyzed each prescription for legibility and completeness, and applied a structured questionnaire to the users or their caregivers on their knowledge regarding treatment and user sociodemographic data. An estimated 29.3% of prescriptions had one or more illegible items, 91.3% had one or more missing items, and 29.0% had both illegible and missing items. Dosing schedule and patient identification were the most commonly unreadable items in prescriptions, 18.81% and 12.14%, respectively. The lack of complete patient identification occurred in 90.53% of the prescriptions. It is estimated that 40.3% of users have used antimicrobials without prescription and that 46.49% did not receive any guidance on the administration of the drug.Despite the measures taken by health authorities to restrict the misuse of antimicrobials, it was observed that prescribers still do not follow the criteria of current legislation, particularly relating to items needed for completion of the prescription. Moreover, users receive little information about their antimicrobial treatment.

The In Vitro Antimicrobial Activity of Lavandula angustifolia Essential Oil in Combination with Other Aroma-Therapeutic Oils

Science.gov (United States)

de Rapper, Stephanie; Kamatou, Guy; Viljoen, Alvaro

2013-01-01

The antimicrobial activity of Lavandula angustifolia essential oil was assessed in combination with 45 other oils to establish possible interactive properties. The composition of the selected essential oils was confirmed using GC-MS with a flame ionization detector. The microdilution minimum inhibitory concentration (MIC) assay was undertaken, whereby the fractional inhibitory concentration (ΣFIC) was calculated for the oil combinations. When lavender oil was assayed in 1 : 1 ratios with other oils, synergistic (26.7%), additive (48.9%), non-interactive (23.7%), and antagonistic (0.7%) interactions were observed. When investigating different ratios of the two oils in combination, the most favourable interactions were when L. angustifolia was combined with Cinnamomum zeylanicum or with Citrus sinensis, against C. albicans and S. aureus, respectively. In 1 : 1 ratios, 75.6% of the essential oils investigated showed either synergistic or additive results, lending in vitro credibility to the use of essential oil blends in aroma-therapeutic practices. Within the field of aromatherapy, essential oils are commonly employed in mixtures for the treatment of infectious diseases; however, very little evidence exists to support the use in combination. This study lends some credence to the concomitant use of essential oils blended with lavender. PMID:23737850

The In Vitro Antimicrobial Activity of Lavandula angustifolia Essential Oil in Combination with Other Aroma-Therapeutic Oils

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Stephanie de Rapper

2013-01-01

Full Text Available The antimicrobial activity of Lavandula angustifolia essential oil was assessed in combination with 45 other oils to establish possible interactive properties. The composition of the selected essential oils was confirmed using GC-MS with a flame ionization detector. The microdilution minimum inhibitory concentration (MIC assay was undertaken, whereby the fractional inhibitory concentration (ΣFIC was calculated for the oil combinations. When lavender oil was assayed in 1 : 1 ratios with other oils, synergistic (26.7%, additive (48.9%, non-interactive (23.7%, and antagonistic (0.7% interactions were observed. When investigating different ratios of the two oils in combination, the most favourable interactions were when L. angustifolia was combined with Cinnamomum zeylanicum or with Citrus sinensis, against C. albicans and S. aureus, respectively. In 1 : 1 ratios, 75.6% of the essential oils investigated showed either synergistic or additive results, lending in vitro credibility to the use of essential oil blends in aroma-therapeutic practices. Within the field of aromatherapy, essential oils are commonly employed in mixtures for the treatment of infectious diseases; however, very little evidence exists to support the use in combination. This study lends some credence to the concomitant use of essential oils blended with lavender.

Combining nonthermal technologies to control foodborne microorganisms.

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Ross, Alexander I V; Griffiths, Mansel W; Mittal, Gauri S; Deeth, Hilton C

2003-12-31

Novel nonthermal processes, such as high hydrostatic pressure (HHP), pulsed electric fields (PEFs), ionizing radiation and ultrasonication, are able to inactivate microorganisms at ambient or sublethal temperatures. Many of these processes require very high treatment intensities, however, to achieve adequate microbial destruction in low-acid foods. Combining nonthermal processes with conventional preservation methods enhances their antimicrobial effect so that lower process intensities can be used. Combining two or more nonthermal processes can also enhance microbial inactivation and allow the use of lower individual treatment intensities. For conventional preservation treatments, optimal microbial control is achieved through the hurdle concept, with synergistic effects resulting from different components of the microbial cell being targeted simultaneously. The mechanisms of inactivation by nonthermal processes are still unclear; thus, the bases of synergistic combinations remain speculative. This paper reviews literature on the antimicrobial efficiencies of nonthermal processes combined with conventional and novel nonthermal technologies. Where possible, the proposed mechanisms of synergy is mentioned.

Oral administration of antimicrobials increase antimicrobial resistance in E. coli from chicken--a systematic review.

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Simoneit, C; Burow, E; Tenhagen, B-A; Käsbohrer, A

2015-01-01

Antimicrobials play an important role in animal and human health care. It was the aim of this systematic review to assess the effects of oral administration of antimicrobials on the development of antimicrobial resistance (AMR) in Escherichia coli (E. coli) from chickens. Moreover, the effects of the administration of more than one antimicrobial and of different dosages were studied. Literature was searched in November 2012 from the electronic databases ISI Web of Science, PubMed, Scopus and a national literature database (DIMDI) as well as the database ProQuest LLC. The search was updated in March 2014. Original studies describing a treatment (A) and a control group of either non-treatment (C) or initial value (0) and determining AMR in E. coli at different sample points (SP) were included. The literature search resulted in 35 full text articles on the topic, seven (20%) of which contained sufficient information on the administered antimicrobial and the impact of treatment on AMR. Most papers described the use of more than one antimicrobial, several dosages, controls (non-treatment or pre-treatment) and measured AMR at different SPs leading to a total of 227 SPs on the impact of the use of antimicrobials on AMR in chickens. 74% of the SPs (168/227) described a higher AMR-rate in E. coli from treated animals than from controls. After the administration of a single antimicrobial, AMR increased at 72% of the SPs. Administration of more than one antimicrobial increased AMR at 82% of the SPs. Higher dosages were associated with similar or higher AMR rates. The limited number of studies for each antimicrobial agent and the high variability in the resistance effect call for more well designed studies on the impact of oral administration on AMR development and spread. Copyright © 2014 Elsevier B.V. All rights reserved.

Inactivation of E.coli O157:H7 and Salmonella on fresh strawberries by antimicrobial washing and coating

Science.gov (United States)

Antimicrobial washing, antimicrobial coating, and a combination of both treatments were evaluated for their ability to inactivate artificially inoculated foodborne pathogens and native microflora on strawberries stored at 4 degrees C. Strawberries were inoculated with a six-strain composite of E. co...

Inhalable Antimicrobials for Treatment of Bacterial Biofilm-Associated Sinusitis in Cystic Fibrosis Patients

DEFF Research Database (Denmark)

Klodzinska, Sylvia Natalie; Priemel, Petra Alexandra; Rades, Thomas

2016-01-01

Bacterial biofilm-associated chronic sinusitis in cystic fibrosis (CF) patients caused by Pseudomonas aeruginosa infections and the lack of available treatments for such infections constitute a critical aspect of CF disease management. Currently, inhalation therapies to combat P. aeruginosa infec...... and management of biofilm infections caused by P. aeruginosa and discusses critical issues related to novel antimicrobial drug formulation design approaches.......Bacterial biofilm-associated chronic sinusitis in cystic fibrosis (CF) patients caused by Pseudomonas aeruginosa infections and the lack of available treatments for such infections constitute a critical aspect of CF disease management. Currently, inhalation therapies to combat P. aeruginosa....... aeruginosa from the respiratory tract after a first infection has been shown to delay chronic pulmonary infection with the bacteria for up to two years. The challenges with providing a suitable treatment for bacterial sinusitis include: (i) identifying a suitable antimicrobial compound; (ii) selecting...

In vitro activity of colistin in antimicrobial combination against carbapenem-resistant Acinetobacter baumannii isolated from patients with ventilator-associated pneumonia in Vietnam.

Science.gov (United States)

Le Minh, Vien; Thi Khanh Nhu, Nguyen; Vinh Phat, Voong; Thompson, Corinne; Huong Lan, Nguyen Phu; Thieu Nga, Tran Vu; Thanh Tam, Pham Thi; Tuyen, Ha Thanh; Hoang Nhu, Tran Do; Van Hao, Nguyen; Thi Loan, Huynh; Minh Yen, Lam; Parry, Christopher M; Trung Nghia, Ho Dang; Campbell, James I; Hien, Tran Tinh; Thwaites, Louise; Thwaites, Guy; Van Vinh Chau, Nguyen; Baker, Stephen

2015-10-01

Acinetobacter baumannii has become one of the major infection threats in intensive care units (ICUs) globally. Since 2008, A. baumannii has been the leading cause of ventilator-associated pneumonia (VAP) in our ICU at an infectious disease hospital in southern Vietnam. The emergence of this pathogen in our setting is consistent with the persistence of a specific clone exhibiting resistance to carbapenems. Antimicrobial combinations may be a strategy to treat infections caused by these carbapenem-resistant A. baumannii. Therefore, we assessed potential antimicrobial combinations against local carbapenem-resistant A. baumannii by measuring in vitro interactions of colistin with four antimicrobials that are locally certified for treating VAP. We first performed antimicrobial susceptibility testing and multilocus variable number tandem repeat analysis (MLVA) genotyping on 74 A. baumannii isolated from quantitative tracheal aspirates from patients with VAP over an 18-month period. These 74 isolates could be subdivided into 21 main clusters by MLVA and >80 % were resistant to carbapenems. We selected 56 representative isolates for in vitro combination synergy testing. Synergy was observed in four (7 %), seven (13 %), 20 (36 %) and 38 (68 %) isolates with combinations of colistin with ceftazidime, ceftriaxone, imipenem and meropenem, respectively. Notably, more carbapenem-resistant A. baumannii isolates (36/43; 84 %) exhibited synergistic activity with a combination of colistin and meropenem than carbapenem-susceptible A. baumannii isolates (2/13; 15 %) (P = 0.023; Fisher's exact test). Our findings suggest that combinations of colistin and meropenem should be considered when treating carbapenem-resistant A. baumannii infections in Vietnam, and we advocate clinical trials investigating combination therapy for VAP.

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

DEFF Research Database (Denmark)

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

2015-01-01

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

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

DEFF Research Database (Denmark)

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

2015-01-01

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

Antimicrobial activity of different filling pastes for deciduous tooth treatment

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Bruna Feltrin ANTONIAZZI

2015-01-01

Full Text Available Guedes-Pinto paste is the filling material most employed in Brazil for endodontic treatment of deciduous teeth; however, the Rifocort® ointment has been removed. Thus, the aim of this study was to investigate the antimicrobial potential of filling pastes, by proposing three new pharmacological associations to replace Rifocort® ointment with drugs of already established antimicrobial power: Nebacetin® ointment, 2% Chlorhexidine Gluconate gel, and Maxitrol® ointment. A paste composed of Iodoform, Rifocort® ointment and Camphorated Paramonochlorophenol (CPC was employed as the gold standard (G1. The other associations were: Iodoform, Nebacetin® ointment and CPC (G2; Iodoform, 2% Chlorhexidine Digluconate gel and CPC (G3; Iodoform, Maxitrol® ointment and CPC (G4. The associations were tested for Staphylococcus aureus (S. aureus, Streptococcus mutans (S. mutans, Streptococcus oralis (S. oralis, Enterococcus faecalis (E. faecalis, Escherichia coli (E. coli, and Bacillus subtilis (B. subtilis, using the methods of dilution on solid medium – orifice agar – and broth dilution. The results were tested using statistical analysis ANOVA and Kruskal-Wallis. They showed that all the pastes had a bacteriostatic effect on all the microorganisms, without any statistically significant difference, compared with G1. S. aureus was statistically significant (multiple comparison test of Tukey, insofar as G2 and G3 presented the worst and the best performance, respectively. All associations were bactericidal for E. coli, S. aureus, S. mutans and S. oralis. Only G3 and G4 were bactericidal for E. faecalis, whereas no product was bactericidal for B. subtilis. Thus, the tested pastes have antimicrobial potential and have proved acceptable for endodontic treatment of primary teeth.

Mastitis therapy and antimicrobial susceptibility: a multispecies review with a focus on antibiotic treatment of mastitis in dairy cattle.

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Barlow, John

2011-12-01

Mastitis occurs in numerous species. Antimicrobial agents are used for treatment of infectious mastitis in dairy cattle, other livestock, companion animals, and humans. Mastitis is an economically important disease of dairy cattle and most mastitis research has focused on epidemiology and control of bovine mastitis. Antibiotic treatment of clinical and subclinical mastitis in dairy cattle is an established component of mastitis control programs. Research on the treatment of clinical and subclinical mastitis in other dairy species such as sheep and goats has been less frequent, although the general principles of mastitis therapy in small ruminants are similar to those of dairy cattle. Research on treatment of clinical mastitis in humans is limited and as for other species empirical treatment of mastitis appears to be common. While antimicrobial susceptibility testing is recommended to direct treatment decisions in many clinical settings, the use of susceptibility testing for antibiotic selection for mastitis treatments of dairy cattle has been challenged in a number of publications. The principle objective of this review is to summarize the literature evaluating the question, "Does antimicrobial susceptibility predict treatment outcome for intramammary infections caused by common bacterial pathogens?" This review also addresses current issues related to antimicrobial use and treatment decisions for mastitis in dairy cattle. Information on treatment of mastitis in other species, including humans, is included although research appears to be limited. Issues related to study design, gaps in current knowledge and opportunities for future research are identified for bovine mastitis therapy.

Mechanisms of antimicrobial resistance among hospital-associated pathogens.

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Khan, Ayesha; Miller, William R; Arias, Cesar A

2018-04-01

The introduction of antibiotics revolutionized medicine in the 20th-century permitting the treatment of once incurable infections. Widespread use of antibiotics, however, has led to the development of resistant organisms, particularly in the healthcare setting. Today, the clinician is often faced with pathogens carrying a cadre of resistance determinants that severely limit therapeutic options. The genetic plasticity of microbes allows them to adapt to stressors via genetic mutations, acquisition or sharing of genetic material and modulation of genetic expression leading to resistance to virtually any antimicrobial used in clinical practice. Areas covered: This is a comprehensive review that outlines major mechanisms of resistance in the most common hospital-associated pathogens including bacteria and fungi. Expert commentary: Understanding the genetic and biochemical mechanisms of such antimicrobial adaptation is crucial to tackling the rapid spread of resistance, can expose unconventional therapeutic targets to combat multidrug resistant pathogens and lead to more accurate prediction of antimicrobial susceptibility using rapid molecular diagnostics. Clinicians making treatment decisions based on the molecular basis of resistance may design therapeutic strategies that include de-escalation of broad spectrum antimicrobial usage, more focused therapies or combination therapies. These strategies are likely to improve patient outcomes and decrease the risk of resistance in hospital settings.

Testing the efficacy of antimicrobial peptides in the topical treatment of induced osteomyelitis in rats.

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Melicherčík, Pavel; Čeřovský, Václav; Nešuta, Ondřej; Jahoda, David; Landor, Ivan; Ballay, Rastislav; Fulín, Petr

2018-01-01

Joint replacement infections and osteomyelitis are among the most serious complications in orthopaedics and traumatology. The risk factors for these infections are often bacterial resistance to antimicrobials. One of the few solutions available to control bacterial resistance involves antimicrobials, which have a different mechanism of action from traditional antibiotics. Antimicrobial peptides (AMP) appear to be highly promising candidates in the treatment of resistant infections. We have identified several AMP in the venom of various wild bees and designed analogues that show potent antimicrobial activity and low toxicity against eukaryotic cells. The aim of the present study was to test the efficacy of one of those synthetic peptide analogues for the treatment of acute osteomyelitis invoked in laboratory rats. Femoral cavities of 20 laboratory Wistar rats were infected with Staphylococcus aureus. After 1 week, eight rats received an injectable calcium phosphate carrier alone, another eight rats were treated with a calcium phosphate mixed with AMP, and four rats were left without any further treatment. After another week, all rats were euthanized and radiographs were made of both the operated and healthy limbs. The animals with the carrier alone exhibited more severe acute osteomyelitis on radiographs in comparison to the recipients of the calcium phosphate carrier loaded AMP and untreated infected individuals. Based on the results of the above mentioned experiment, it was concluded that when injected directly into the site of femoral acute osteomyelitis, the calcium phosphate carrier mixed with AMP reduced osteomyelitis signs visible on radiographs.

Diversity of fecal coliforms and their antimicrobial resistance patterns in wastewater treatment model plant.

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Luczkiewicz, A; Fudala-Ksiazek, S; Jankowska, K; Quant, B; Olańczuk-Neyman, K

2010-01-01

The occurrence of resistance patterns among wastewater fecal coliforms was determined in the study. Susceptibility of the isolates was tested against 19 antimicrobial agents: aminoglycosides, aztreonam, carbapenems, cephalosporines, beta-lactam/beta-lactamase inhibitors, penicillines, tetracycline, trimethoprim/sulfamethoxazole, and fluoroquinolones. Additionally the removal of resistant isolates was evaluated in the laboratory-scale wastewater treatment model plant (M-WWTP), continuously supplied with the wastewater obtained from the full-scale WWTP. Number of fecal coliforms in raw (after mechanical treatment) and treated wastewater, as well as in aerobic chamber effluent was determined using selective medium. The selected strains were identified and examined for antibiotic resistance using Phoenix Automated Microbiology System (BD Biosciences, USA). The strains were identified as Escherichia coli (n=222), Klebsiella pneumoniae ssp. ozaenae (n=9), and Pantoea agglomerans (n=1). The isolate of P. agglomerans as well as 48% of E. coli isolates were sensitive to all antimicrobials tested. The most frequent resistance patterns were found for ampicillin: 100% of K. pneumoniae ssp. ozaenae and 41% of E. coli isolates. Among E. coli isolates 12% was regarded as multiple antimicrobial resistant (MAR). In the studied M-WWTP, the applied activated sludge processes reduced considerably the number of fecal coliforms, but increased the ratio of antimicrobial-resistant E. coli isolates to sensitive ones, especially among strains with MAR patterns.

New antimicrobial combinations: substituted chalcones- oxacillin against methicillin resistant Staphylococcus aureus

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Juan Manuel Talia

2011-06-01

Full Text Available Staphylococcus aureus, the most virulent Staphylococcus species, is also the prevalent pathogen isolated from hospitalized patients and the second most common from patients in outpatient settings. In general, bacteria have the genetic ability to transmit and acquire resistance to drugs, which are utilized as therapeutic agents. Related studies of antimicrobial activity indicate that crude extracts containing flavonoids, triterpenes and steroids have showed significative activity against several Staphylococcus aureus strains. Combination effects between flavonoids and antibiotics also have been reported. The aim of the present work was to investigate in vitro synergism between several chalcones substituted in combination with oxacillin, an antibiotic used conventionally against S. aureus ATCC 43 300 that is resistant to meticillin, using the kinetic turbidimetric method developed earlier. The results were satisfactory for all assayed combinations and in accordance with the mechanism of bacteriostatic inhibition previously proposed, except for 2´,4´-dihydroxy-3´-methoxychalcone - oxacillin. The best combination was 2´,3´-dihydroxychalcone - oxacillin (MIC: 11.2 μg/mL. Further investigations are needed to characterize the interaction mechanism with antibiotics. Thus, chalcones - oxacillin combination could lead to the development of new antibiotics against methicillin resistant S. aureus infection.

Suggested guidelines for using systemic antimicrobials in bacterial skin infections: part?2? antimicrobial choice, treatment regimens and compliance

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Beco, L.; Guagu?re, E.; M?ndez, C. Lorente; Noli, C.; Nuttall, T.; Vroom, M.

2013-01-01

Systemic antimicrobials are critically important in veterinary healthcare, and resistance is a major concern. Antimicrobial stewardship will be important in maintaining clinical efficacy by reducing the development and spread of antimicrobial resistance. Bacterial skin infections are one of the most common reasons for using systemic antimicrobials in dogs and cats. Appropriate management of these infections is, therefore, crucial in any policy for responsible antimicrobial use. The goals of t...

Emerging Gram negative resistance to last-line antimicrobial agents fosfomycin, colistin and ceftazidime-avibactam - epidemiology, laboratory detection and treatment implications.

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Sherry, Norelle; Howden, Benjamin

2018-04-01

Multidrug-resistant (MDR) and extensively-drug-resistant (XDR) Gram-negative bacteria have emerged as a major threat to human health globally. This has resulted in the 're-discovery' of some older antimicrobials and development of new agents, however resistance has also rapidly emerged to these agents. Areas covered: Here we describe recent developments in resistance to three of the most important last-line antimicrobials for treatment of MDR and XDR Gram negatives: fosfomycin, colistin and ceftazidime-avibactam. Expert commentary: A key challenge for microbiologists and clinicians using these agents for treating patients with MDR and XDR Gram negative infections is the need to ensure appropriate reference methods are being used to test susceptibility to these agents, especially colistin and fosfomycin. These methods are not available in all laboratories meaning accurate results are either delayed, or potentially inaccurate as non-reference methods are employed. Combination therapy for MDR and XDR Gram negatives is likely to become more common, and future studies should focus on the clinical effects of monotherapy vs combination therapy, as well as validation of synergy testing methods. Effective national and international surveillance systems to detect and respond to resistance to these last line agents are also critical.

In vitro evaluation of the antimicrobial effect of a raw bacteriocin extract in combination with chemical preservatives employed in meat industry

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Luis A. Aguado Bautista

2010-12-01

Full Text Available Biopreservation can be defined as the foods shelf life extension employing antibacterial products like bacteriocins. The objective of this work was to determinate the efficacy of E. faecium MXVK29 bacteriocin in combination with chemical preservatives against spoilage and pathogens microorganisms. Bacteriocin raw extrac antimicrobial activity was 46.34 UA/g of protein. Growth of Pseudomonas putida was not affected by the preservatives employed at the conditions employed. Antimicrobial response was different for other microorganisms since a synergetic effect of the preservatives combination inhibited Brochothrix thermosphacta and Escherichia coli growth. Sodium lactate had additive effect only against Listeria innocua.

Antimicrobial Stewardship and Urinary Tract Infections

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Lilian M. Abbo

2014-05-01

Full Text Available Urinary tract infections are the most common bacterial infections encountered in ambulatory and long-term care settings in the United States. Urine samples are the largest single category of specimens received by most microbiology laboratories and many such cultures are collected from patients who have no or questionable urinary symptoms. Unfortunately, antimicrobials are often prescribed inappropriately in such patients. Antimicrobial use, whether appropriate or inappropriate, is associated with the selection for antimicrobial-resistant organisms colonizing or infecting the urinary tract. Infections caused by antimicrobial-resistant organisms are associated with higher rates of treatment failures, prolonged hospitalizations, increased costs and mortality. Antimicrobial stewardship consists of avoidance of antimicrobials when appropriate and, when antimicrobials are indicated, use of strategies to optimize the selection, dosing, route of administration, duration and timing of antimicrobial therapy to maximize clinical cure while limiting the unintended consequences of antimicrobial use, including toxicity and selection of resistant microorganisms. This article reviews successful antimicrobial stewardship strategies in the diagnosis and treatment of urinary tract infections.

Antimicrobial Activity of Individual and Combined Essential Oils against Foodborne Pathogenic Bacteria.

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Reyes-Jurado, Fatima; López-Malo, Aurelio; Palou, Enrique

2016-02-01

The antimicrobial activities of essential oils from Mexican oregano (Lippia berlandieri Schauer), mustard (Brassica nigra), and thyme (Thymus vulgaris) were evaluated alone and in binary combinations against Listeria monocytogenes, Staphylococcus aureus, or Salmonella Enteritidis. Chemical compositions of the essential oils were analyzed by gas chromatography-mass spectrometry. The MICs of the evaluated essential oils ranged from 0.05 to 0.50% (vol/vol). Mustard essential oil was the most effective, likely due to the presence of allyl isothiocyanate, identified as its major component. Furthermore, mustard essential oil exhibited synergistic effects when combined with either Mexican oregano or thyme essential oils (fractional inhibitory concentration indices of 0.75); an additive effect was obtained by combining thyme and Mexican oregano essential oils (fractional inhibitory concentration index = 1.00). These results suggest the potential of studied essential oil mixtures to inhibit microbial growth and preserve foods; however, their effect on sensory quality in selected foods compatible with their flavor needs to be assessed.

The Structure Characteristics and Air Permeability of PA and PES Plain and Plated Knits Influenced of Antimicrobial Treatment Conditions

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Agne MICKEVIČIENĖ

2014-09-01

Full Text Available Textile materials are usually exposed to thermal, physical and mechanical effects during treatment processes. These influence the changes of material dimensions. Designing knitted products it is important to predict direction and rate of dimensions change, because this can affect physical properties such as air permeability of knits. The objective of this research was to investigate the influence of antimicrobial treatment conditions on the structure characteristics, thickness and air permeability of plain and plaited knits. The investigations were carried out with two groups of plain and plated single jersey knits. The face yarns of these groups were cotton, bamboo viscose yarn and polyester (Dacron® thread. 10 tex × 2 textured polyamide (PA and 20 tex textured polyester (PES threads were used as the base threads in plated knits. Knitted samples were treated with antimicrobial material Isys AG and organic-inorganic binder Isys MTX (CHT, Germany. It was established that blank and antimicrobial treated knits changed structure parameters, thickness and air permeability. The changes of structure parameters, thickness and air permeability were more associated with conditions of treatment (temperature, treatment in solution, mechanical action rather than with antimicrobial and sol-gel substances used in treatment. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.3196

Antimicrobial Activity of Bee Venom and Melittin against Borrelia burgdorferi.

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Socarras, Kayla M; Theophilus, Priyanka A S; Torres, Jason P; Gupta, Khusali; Sapi, Eva

2017-11-29

Lyme disease is a tick-borne, multi-systemic disease, caused by the bacterium Borrelia burgdorferi. Though antibiotics are used as a primary treatment, relapse often occurs after the discontinuation of antimicrobial agents. The reason for relapse remains unknown, however previous studies suggest the possible presence of antibiotic resistant Borrelia round bodies, persisters and attached biofilm forms. Thus, there is an urgent need to find antimicrobial agents suitable to eliminate all known forms of B. burgdorferi . In this study, natural antimicrobial agents such as Apis mellifera venom and a known component, melittin, were tested using SYBR Green I/PI, direct cell counting, biofilm assays combined with LIVE/DEAD and atomic force microscopy methods. The obtained results were compared to standalone and combinations of antibiotics such as Doxycycline, Cefoperazone, Daptomycin, which were recently found to be effective against Borrelia persisters. Our findings showed that both bee venom and melittin had significant effects on all the tested forms of B. burgdorferi. In contrast, the control antibiotics when used individually or even in combinations had limited effects on the attached biofilm form. These findings strongly suggest that whole bee venom or melittin could be effective antimicrobial agents for B. burgdorferi; however, further research is necessary to evaluate their effectiveness in vivo, as well as their safe and effective delivery method for their therapeutic use.

Antimicrobial resistance mechanisms among Campylobacter.

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Wieczorek, Kinga; Osek, Jacek

2013-01-01

Campylobacter jejuni and Campylobacter coli are recognized as the most common causative agents of bacterial gastroenteritis in the world. Humans most often become infected by ingesting contaminated food, especially undercooked chicken, but also other sources of bacteria have been described. Campylobacteriosis is normally a self-limiting disease. Antimicrobial treatment is needed only in patients with more severe disease and in those who are immunologically compromised. The most common antimicrobial agents used in the treatment of Campylobacter infections are macrolides, such as erythromycin, and fluoroquinolones, such as ciprofloxacin. Tetracyclines have been suggested as an alternative choice in the treatment of clinical campylobacteriosis but in practice are not often used. However, during the past few decades an increasing number of resistant Campylobacter isolates have developed resistance to fluoroquinolones and other antimicrobials such as macrolides, aminoglycosides, and beta-lactams. Trends in antimicrobial resistance have shown a clear correlation between use of antibiotics in the veterinary medicine and animal production and resistant isolates of Campylobacter in humans. In this review, the patterns of emerging resistance to the antimicrobial agents useful in treatment of the disease are presented and the mechanisms of resistance to these drugs in Campylobacter are discussed.

Antimicrobial drug use and related management practices among Ontario swine producers.

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Dunlop, R H; McEwen, S A; Meek, A H; Friendship, R A; Clarke, R C; Black, W D

1998-02-01

A mail survey of swine producers in Ontario was undertaken during 1991 to describe the types, frequency, and motives for antimicrobial use. Two hundred operations that marketed fewer than 350 hogs per year, and 800 that marketed more than 350 per year were sent questionnaires, 63% of which were completed and returned. Most operations (86%) added antimicrobials to starter (weanling pig) rations, while fewer (29%) added these drugs to finisher pig rations. The most commonly used antimicrobials were tylosin, carbadox, and furazolidone in weanling pigs, and tylosin, lincomycin, and tetracycline in finishers. Water medication of grower-finisher pigs was practised on 25% of farms; 80% of farms had injected at least some grower-finisher pigs with antimicrobials in the 12 mo preceding the survey. Approximately 20% of operations that added antimicrobials to finisher rations did so for growth promotion purposes only, while others used them for disease treatment, prevention, control, or a combination of reasons. Among those not using antimicrobials in finisher rations, 83% did not believe they were necessary and 37% were concerned about the potential for residues in marketed hogs.

Novel natural food antimicrobials.

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Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

2012-01-01

Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry.

The Rising Tide of Antimicrobial Resistance in Aquaculture: Sources, Sinks and Solutions.

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Watts, Joy E M; Schreier, Harold J; Lanska, Lauma; Hale, Michelle S

2017-06-01

As the human population increases there is an increasing reliance on aquaculture to supply a safe, reliable, and economic supply of food. Although food production is essential for a healthy population, an increasing threat to global human health is antimicrobial resistance. Extensive antibiotic resistant strains are now being detected; the spread of these strains could greatly reduce medical treatment options available and increase deaths from previously curable infections. Antibiotic resistance is widespread due in part to clinical overuse and misuse; however, the natural processes of horizontal gene transfer and mutation events that allow genetic exchange within microbial populations have been ongoing since ancient times. By their nature, aquaculture systems contain high numbers of diverse bacteria, which exist in combination with the current and past use of antibiotics, probiotics, prebiotics, and other treatment regimens-singularly or in combination. These systems have been designated as "genetic hotspots" for gene transfer. As our reliance on aquaculture grows, it is essential that we identify the sources and sinks of antimicrobial resistance, and monitor and analyse the transfer of antimicrobial resistance between the microbial community, the environment, and the farmed product, in order to better understand the implications to human and environmental health.

Evaluación de la eficacia in vitro e in vivo del tratamiento antimicrobiano combinado por el tablero de damas Effectiveness of a combined antimicrobial treatment by means of the draughtboard. In vitro and in vivo assessment

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María Espino Hernández

2009-08-01

Full Text Available El presente trabajo tuvo como objetivo, evaluar la eficacia clínica del tratamiento antimicrobiano combinado mediante pruebas de sinergismo in vitro y determinar la eficacia del procedimiento empleado para orientar la aplicación de estas formas de tratamiento en el paciente con sepsis por bacterias con resistencia variada. Se evaluó el tratamiento aplicado a 163 recién nacidos con sepsis corroborada por hemocultivo positivo en el Hospital Ginecobstétrico Universitario "América Arias", durante el periodo de enero de 1993 a diciembre de 2000, por el método tablero de damas (checkerboard en placas de microtitulación. Las combinaciones de fármacos sinérgicas in vitro presentaron una alta probabilidad de eficacia clínica, independiente del patrón de susceptibilidad del microorganismo aun frente a cepas resistentes a los 2 antimicrobianos utilizados en el tratamiento. Todos los resultados antagónicos in vitro se correspondieron con un fallo clínico terapéutico. El procedimiento utilizado puede constituir una valiosa herramienta para orientar la terapéutica en pacientes con sepsis por microorganismos resistentes.The aim of present paper was to evaluate clinical effectiveness of combined antimicrobial treatment by means of in vitro synergism tests and to determine effectiveness of used procedure to direct applications of these treatment strategies in patient presenting with sepsis from varied resistance bacteria. Treatment applied was assessed in 163 newborn patients presenting with sepsis from positive hemoculture in "America Arias" University Gynecology-Obstetrics Hospital from January 1993 to December 2000, by checkerboard method in microtritate plates. In vitro synergic drug combinations showed a high probability of clinical effectiveness, independently of susceptibility pattern of microorganism event versus resistant strains to both antimicrobials used in treatment. All in vitro antagonistic results correspond both with a

Effect of different oral oxytetracycline treatment regimes on selection of antimicrobial resistant coliforms in nursery pigs.

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Herrero-Fresno, Ana; Zachariasen, Camilla; Nørholm, Nanna; Holm, Anders; Christiansen, Lasse Engbo; Olsen, John Elmerdahl

2017-09-01

A major concern derived from using antimicrobials in pig production is the development of resistance. This study aimed to assess the impact of selected combinations of oral dose and duration of treatment with oxytetracycline (OTC) on selection of tetracycline resistant (TET-R) coliforms recovered from swine feces. The work encompassed two studies: 1) OTC 5mg/kg and 20mg/kg were administered to nursery pigs for 3 and 10days, respectively, under controlled experimental conditions, and 2) 10mg/kg, 20mg/kg and 30mg/kg OTC were given to a higher number of pigs for 6, 3 and 2days, respectively, under field conditions. Statistical modeling was applied to analyze trends in the proportion of TET-R coliforms. In the experimental study, no statistical difference in proportion of TET-R coliforms was observed between treatments at the end of the trial (day 18) and compared to day 0. In the field study, treatment had a significant effect on the proportion of TET-R bacteria two days after the end of treatment (2dAT) with the regimes "low dose-six days" and "medium dose-three days" yielding the highest and lowest proportions of TET-R strains, respectively. No indication of co-selection for ampicillin- and sulphonamide -R bacteria was observed for any treatment at 2dAT. By the end of the nursery period, the proportion of TET-R bacteria was not significantly different between treatments and compared to day 0. Our results suggest that similar resistance levels might be obtained by using different treatment regimes regardless of the combinations of oral dose-duration of treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Impregnation of silver sulfadiazine into bacterial cellulose for antimicrobial and biocompatible wound dressing

International Nuclear Information System (INIS)

Luan, Jiabin; Wu, Jian; Zheng, Yudong; Wang, Guojie; Guo, Jia; Ding, Xun; Song, Wenhui

2012-01-01

Silver sulfadiazine (SSD) is a useful antimicrobial agent for wound treatment. However, recent findings indicate that conventional SSD cream has several drawbacks for use in treatments. Bacterial cellulose (BC) is a promising material for wound dressing due to its outstanding properties of holding water, strength and degradability. Unfortunately, BC itself exhibits no antimicrobial activity. A combination of SSD and BC is envisaged to form a new class of wound dressing with both antimicrobial activity and biocompatibility, which has not been reported to date. To achieve antimicrobial activity, SSD particles were impregnated into BC by immersing BC into SSD suspension after ultrasonication, namely SSD–BC. Parameters influencing SSD–BC impregnation were systematically studied. Optimized conditions of sonication time for no less than 90 min and the proper pH value between 6.6 and 9.0 were suggested. The absorption of SSD onto the BC nanofibrous network was revealed by XRD and SEM analyses. The SSD–BC membranes exhibited significant antimicrobial activities against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus evaluated by the disc diffusion method. In addition, the favorable biocompatibility of SSD–BC was verified by MTT colorimetry, epidermal cell counting method and optical microscopy. The results demonstrate the potential of SSD–BC membranes as a new class of antimicrobial and biocompatible wound dressing. (paper)

Modeling of combined effects of citral, linalool and beta-pinene used against Saccharomyces cerevisiae in citrus-based beverages subjected to a mild heat treatment.

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Belletti, Nicoletta; Kamdem, Sylvain Sado; Tabanelli, Giulia; Lanciotti, Rosalba; Gardini, Fausto

2010-01-01

The aim of this work was to evaluate the antimicrobial activity of three terpenes (citral, linalool and beta-pinene), in combination with a mild heat treatment (55 degrees C, 15 min). The study has been carried out on an orange based soft drink inoculated using a wild strain of Saccharomyces cerevisiae. The results, expressed as growth/no-growth data, were analyzed with the logistic regression. A model comprising only of significant individual parameters (p < or = 0.05) and describing the relationships between terpene concentrations and the probability of having stable beverages was obtained. When citral and beta-pinene were combined, the citral concentration required to achieve a 50% probability of having stable bottles (P=0.5) dropped from 100.9 microL/L in the absence of beta-pinene to 49.3 microL/L in the presence of 20 microL/L of beta-pinene. The mixture of citral and linalool was less effective, in fact, the same probability (P=0.5) was obtained combining 60 microL/L of linalool with 35.1 microL/L of citral. The addition of 20 microL/L of linalool and beta-pinene reinforced citral bioactivity and the concentration of citral needed to reach P=0.5 fell from 100.9 microL/L in the presence of citral alone to 42.0 microL/L. The presence of both linalool and beta-pinene at a concentration of 40 or 60 microL/L in the absence of citral led to a lower spoilage probability (P=0.58 and P=0.93, respectively). It can be concluded that the antimicrobial potential of the three terpenes alone can be strengthened combining appropriate concentrations of each of them. This study confirmed also the potentiating effect of a mild temperature treatment on the antimicrobial efficacy of the molecules. Neither the thermal treatment alone nor the presence of the terpenes at their maximum concentrations (without thermal treatment) were able to guarantee the microbial stability of the beverages. 2009 Elsevier B.V. All rights reserved.

The synthetic human beta-defensin-3 C15 peptide exhibits antimicrobial activity against Streptococcus mutans, both alone and in combination with dental disinfectants.

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Ahn, Ki Bum; Kim, A Reum; Kum, Kee-Yeon; Yun, Cheol-Heui; Han, Seung Hyun

2017-10-01

Streptococcus mutans is a major etiologic agent of human dental caries that forms biofilms on hard tissues in the human oral cavity, such as tooth and dentinal surfaces. Human β-defensin-3 (HBD3) is a 45-amino-acid natural antimicrobial peptide that has broad spectrum antimicrobial activity against bacteria and fungi. A synthetic peptide consisting of the C-terminal 15 amino acids of HBD3 (HBD3-C15) was recently shown to be sufficient for its antimicrobial activity. Thus, clinical applications of this peptide have garnered attention. In this study, we investigated whether HBD3-C15 inhibits the growth of the representative cariogenic pathogen Streptococcus mutans and its biofilm formation. HBD3-C15 inhibited bacterial growth, exhibited bactericidal activity, and attenuated bacterial biofilm formation in a dose-dependent manner. HBD3-C15 potentiated the bactericidal and anti-biofilm activity of calcium hydroxide (CH) and chlorhexidine digluconate (CHX), which are representative disinfectants used in dental clinics, against S. mutans. Moreover, HBD3-C15 showed antimicrobial activity by inhibiting biofilm formation by S. mutans and other dentinophilic bacteria such as Enterococcus faecalis and Streptococcus gordonii, which are associated with dental caries and endodontic infection, on human dentin slices. These effects were observed for HBD3-C15 alone and for HBD3-C15 in combination with CH or CHX. Therefore, we suggest that HBD3-C15 is a potential alternative or additive disinfectant that can be used for the treatment of oral infectious diseases, including dental caries and endodontic infections.

Antimicrobial activity of thyme oil co-nanoemulsified with sodium caseinate and lecithin.

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Xue, Jia; Michael Davidson, P; Zhong, Qixin

2015-10-01

Emulsions of essential oils are investigated as potential intervention strategies to improve food safety and are preferably prepared from generally-recognized-as-safe emulsifiers. Stable thyme oil nanoemulsions can be prepared using combinations of sodium caseinate (NaCas) and soy lecithin. The objective of the present research was to study the antimicrobial activity of these nanoemulsions and understand the impacts of emulsifier concentrations. 10 g/L thyme oil was emulsified using combinations of (A) 4% w/v NaCas and 0.5% w/v lecithin or (B) 2% w/v NaCas and 0.25% w/v lecithin by high shear homogenization. Combination A resulted in a transparent emulsion with a mean droplet diameter of 82.5 nm, while it was turbid for the Combination B with an average diameter of 125.5 nm. Nanoemulsified thyme oil exhibited quicker initial reductions of bacteria than free thyme oil in tryptic soy broth (TSB) and 2% reduced fat milk at 21 °C, due to the improved dispersibility of thyme oil. In TSB with 0.3 g/L thyme oil, it took less than 4 and 8 h for two nanoemulsions and free oil, respectively, to reduce Escherichia coli O157:H7 and Listeria monocytogenes to be below the detection limit. The emulsified thyme oil also demonstrated more significant reductions of bacteria initially (4 and 8 h) in 2% reduced fat milk than free thyme oil. Especially, with 4 g/L thyme oil, the nanoemulsion prepared with Combination A reduced L. monocytogenes to be below the detection limit after 72 h, while the free thyme oil treatment was only bacteriostatic and the turbid nanoemulsion treatment with Combination B resulted in about 1 log CFU/mL reduction. However, E. coli O157:H7 treated with 3 g/L emulsified thyme oil and Salmonella Enteritidis treated with 4 g/L emulsified thyme oil recovered to a higher extent in milk than free thyme oil treatments. The increased concentration of emulsifiers in Combination A apparently reduced the antimicrobials available to alter bacteria membrane permeability

Enhanced bactericidal effect of enterocin AS-48 in combination with high-intensity pulsed-electric field treatment against Salmonella enterica in apple juice.

Science.gov (United States)

Martínez Viedma, Pilar; Sobrino López, Angel; Ben Omar, Nabil; Abriouel, Hikmate; Lucas López, Rosario; Valdivia, Eva; Martín Belloso, Olga; Gálvez, Antonio

2008-12-10

The effect of the broad spectrum cyclic antimicrobial peptide enterocin AS-48 combination with high-intensity pulsed-electric field (HIPEF) treatment (35 kV/cm, 150 Hz, 4 micros and bipolar mode) was tested on Salmonella enterica CECT 915 in apple juice. A response surface methodology was applied to study the bactericidal effects of the combined treatment. The process variables were AS-48 concentration, temperature, and HIPEF treatment time. While treatment with enterocin AS-48 alone up to 60 microg/ml had no effect on the viability of S. enterica in apple juice, an increased bactericidal activity was observed in combination with HIPEF treatments. Survival fraction was affected by treatment time, enterocin AS48 concentration and treatment temperature. The combination of 100 micros of HIPEF treatment, 30 microg/ml of AS-48, and temperature of 20 degrees C resulted in the lowest inactivation, with only a 1.2-log reduction. The maximum inactivation of 4.5-log cycles was achieved with HIPEF treatment for 1000 micros in combination with 60 microg/ml of AS-48 and a treatment temperature of 40 degrees C. Synergism between enterocin AS-48 and HIPEF treatment depended on the sequence order application, since it was observed only when HIPEF was applied in the presence of previously-added bacteriocin. The combined treatment could improve the safety of freshly-made apple juice against S. enterica transmission.

Comparison of treatment records and inventory of empty drug containers to quantify antimicrobial usage in dairy herds.

Science.gov (United States)

Nobrega, Diego B; De Buck, Jeroen; Naqvi, S Ali; Liu, Gang; Naushad, Sohail; Saini, Vineet; Barkema, Herman W

2017-12-01

Assessment of antimicrobial use (AMU) is vital for interpreting the origin of changes in antimicrobial resistance (AMR). The objectives of the present study were to estimate the association between AMU determined using on-farm treatment records (TR) and inventory of empty drug containers (INV). Herds were selected to represent Canadian dairy farms. Producers were asked to record animal health events and treatments on a standard General Health Event form. For inventory data, 40-L receptacles were placed at various locations considered convenient to deposit all empty drug containers. Antimicrobial defined-daily dosages (ADD) were calculated for 51 Canadian herds using the 2 methods. Estimation of AMU was 31,840 ADD using the INV and 14,487 ADD using the TR, indicating that for every TR entry, 2.20 times more treatments were observed using the INV. Mastitis, reproductive conditions, and dry cow therapy were the most frequent reasons for antimicrobial therapy when assessing TR. For all antimicrobials evaluated, mean ADD was higher using the INV versus TR. Regardless, a strong positive correlation (0.80) was observed between the 2 methods, indicating that herds with increased number of ADD recorded using the INV also had increased number of ADD recorded using TR. Furthermore, a positive association was observed for the 6 most commonly used antimicrobials. In comparison to methods used in surveillance programs on AMU in livestock that assume a constant use in all herds (i.e., sales data), INV provided a herd-level specific quantity of AMU positively correlated with AMU recorded at the animal level in general. The INV was easy to implement and provided a measure of total AMU in the herd. Availability of such information would be valuable for interpreting changes in AMR at the herd level and enabling evaluation of interventions for decreasing AMR. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Polymyxins: Antimicrobial susceptibility concerns and therapeutic options

Directory of Open Access Journals (Sweden)

V Balaji

2011-01-01

Full Text Available The increasing prevalence of multidrug-resistant nosocomial pathogens such as Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae poses a great challenge to the treating physicians. The paucity of newer effective antimicrobials has led to renewed interest in the polymyxin group of drugs, as a last resort for treatment of gram-negative bacterial infections. There is a dearth of information on the pharmacological properties of colistin, leading to difficulties in selecting the right dose, dosing interval, and route of administration for treatment, especially in critically-ill patients. The increasing use of colistin over the last few years necessitates the need for accurate and reliable in vitro susceptibility testing methods. Development of heteroresistant strains as a result of colistin monotherapy is also a growing concern. There is a compelling need from the clinicians to provide options for probable and possible colistin combination therapy for multidrug-resistant bacterial infections in the ICU setting. Newer combination drug synergy determination tests are being developed and reported. There are no standardized recommendations from antimicrobial susceptibility testing reference agencies for the testing and interpretation of these drug combinations. Comparison and analysis of these reported methodologies may help to understand and assist the microbiologist to choose the best method that produces accurate results at the earliest. This will help clinicians to select the appropriate combination therapy. In this era of multidrug resistance it is important for the microbiology laboratory to be prepared, by default, to provide timely synergistic susceptibility results in addition to routine susceptibility, if warranted. Not as a favour or at request, but as a responsibility.

Porous CS based membranes with improved antimicrobial properties for the treatment of infected wound in veterinary applications

International Nuclear Information System (INIS)

Tonda-Turo, C.; Ruini, F.; Argentati, M.; Di Girolamo, N.; Robino, P.; Nebbia, P.; Ciardelli, G.

2016-01-01

Recently, much attention has been given to the use of innovative solution for the treatment of infected wounds in animals. Current applied treatments are often un-effective leading to infection propagation and animal death. Novel engineered membranes based on chitosan (CS) can be prepared to combine local antimicrobial effect, high flexibility and easy manipulation. In this work, CS crosslinked porous membranes with improved antimicrobial properties were prepared via freeze-drying technique to promote wound healing and to reduce the bacterial proliferation in infected injuries. Silver nanoparticles (AgNPs) and gentamicin sulfate (GS) were incorporated into the CS matrices to impart antibacterial properties on a wild range of strains. CS based porous membranes were tested for their physicochemical, thermal, mechanical as well as swelling and degradation behavior at physiological condition. Additionally, GS release profile was investigated, showing a moderate burst effect in the first days followed by a decreasing release rate which it was maintained for at least 56 days. Moreover, porous membranes loaded with GS or AgNPs showed good bactericidal activity against both of Gram-positive and Gram-negative bacteria. The bacterial strains used in this work were collected in chelonians after carapace injuries to better mimic the environment after trauma. - Highlights: • Innovative scaffolds for wound healing in veterinary applications • Novel engineered membranes based on chitosan with improved antibacterial properties • Highly flexible and versatile membranes for infected wounds

Porous CS based membranes with improved antimicrobial properties for the treatment of infected wound in veterinary applications

Energy Technology Data Exchange (ETDEWEB)

Tonda-Turo, C., E-mail: chiara.tondaturo@polito.it [Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin (Italy); Ruini, F. [Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin (Italy); Argentati, M. [Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin (Italy); Clinic for Exotic Animals, CVS, Via Sandro Giovannini 53, 00137 Rome (Italy); Di Girolamo, N. [Clinic for Exotic Animals, CVS, Via Sandro Giovannini 53, 00137 Rome (Italy); Robino, P.; Nebbia, P. [Department of Veterinary Sciences, University of Turin, Largo Braccini 2, 10095 Grugliasco, Turin (Italy); Ciardelli, G. [Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin (Italy)

2016-03-01

Recently, much attention has been given to the use of innovative solution for the treatment of infected wounds in animals. Current applied treatments are often un-effective leading to infection propagation and animal death. Novel engineered membranes based on chitosan (CS) can be prepared to combine local antimicrobial effect, high flexibility and easy manipulation. In this work, CS crosslinked porous membranes with improved antimicrobial properties were prepared via freeze-drying technique to promote wound healing and to reduce the bacterial proliferation in infected injuries. Silver nanoparticles (AgNPs) and gentamicin sulfate (GS) were incorporated into the CS matrices to impart antibacterial properties on a wild range of strains. CS based porous membranes were tested for their physicochemical, thermal, mechanical as well as swelling and degradation behavior at physiological condition. Additionally, GS release profile was investigated, showing a moderate burst effect in the first days followed by a decreasing release rate which it was maintained for at least 56 days. Moreover, porous membranes loaded with GS or AgNPs showed good bactericidal activity against both of Gram-positive and Gram-negative bacteria. The bacterial strains used in this work were collected in chelonians after carapace injuries to better mimic the environment after trauma. - Highlights: • Innovative scaffolds for wound healing in veterinary applications • Novel engineered membranes based on chitosan with improved antibacterial properties • Highly flexible and versatile membranes for infected wounds.

Synthesis and characterization of core-shell bimetallic nanoparticles for synergistic antimicrobial effect studies in combination with doxycycline on burn specific pathogens.

Science.gov (United States)

Fakhri, Ali; Tahami, Shiva; Naji, Mahsa

2017-04-01

Nano-medicine is a breakthrough discovery in the healthcare sector. Doxycycline is a new generation antibiotic which is proved to be a boon in the treatment of patients with complicated skin infections. We have tried to explore the benefits of synthesized bimetallic silver-gold nanoparticles in combination with new generation antibiotic for burn infections. The bimetallic nanoparticles synthesized by core-shell method were characterized using scanning electron microscopy equipped with an energy dispersive spectrometer, transmission electron microscopy, X-ray diffraction and UV-Vis spectroscopy. The calculated average particle sizes of the Ag-Au NPs were found to be 27.5nm. The Ag-Au core-shell BNPs show a characteristic Plasmon peak at 525nm which is broad and red shifted. The synergistic antimicrobial activity of doxycycline conjugated bimetallic nanoparticles was investigated against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Micrococcus luteus. This combined therapeutic agent showed greater bactericidal activity. Synergy of antibiotic with bimetallic nanoparticles is quite promising for significant application in burn healing therapy. The mechanism of the antibacterial activity was studied through the formation of reactive oxygen species (ROS) that was later suppressed with antioxidant to establish correlation with the Ag-Au NPs antimicrobial activity. Ag-Au NPs showed effective antiproliferative activity toward A549 human lung cancer (CCL-185) and MCF-7 human breast cancer (HTB-22) cell lines. Copyright © 2017 Elsevier B.V. All rights reserved.

Relationship between antimicrobial susceptibility of clinical mastitis pathogens and treatment outcome in cows.

Science.gov (United States)

Hoe, Fernanda G H; Ruegg, Pamela L

2005-11-01

To determine whether there was any association between results of in vitro antimicrobial susceptibility testing of pathogens isolated from cows with mild or moderate clinical mastitis and outcome of treatment. Observational study. 133 cows with mild or moderate mastitis in a single quarter. Cows were treated by means of intramammary infusion of pirlimycin (50 mg) in the affected quarter once daily for 2 days; additional intramammary treatments with the same product were administered if the milk continued to appear abnormal. Duration of treatment and days until clinical cure were recorded. Bacterial isolates were tested for antimicrobial susceptibility by means of a broth micro-dilution technique. Environmental streptococci, coliforms, and coagulase-negative Staphylococcus spp were the most commonly isolated pathogens. Duration of treatment and days until clinical cure were not significantly different for cows from which pathogens that were susceptible or resistant to pirlimycin were isolated. Bacteriologic cure rates 14 and 21 days after treatment were not significantly different for cows with mastitis caused by susceptible or resistant bacteria. Similar results were found when data only from cows with mastitis caused by gram-positive isolates were analyzed. In the present study, differences in clinical outcome for cows with mild or moderate mastitis that could be attributed to differences in results of in vitro susceptibility testing were not identified. The use of in vitro susceptibility testing to guide intramammary mastitis treatment cannot be recommended on the basis of results of this study.

Antimicrobial use in Belgian broiler production.

Science.gov (United States)

Persoons, Davy; Dewulf, Jeroen; Smet, Annemieke; Herman, Lieve; Heyndrickx, Marc; Martel, An; Catry, Boudewijn; Butaye, Patrick; Haesebrouck, Freddy

2012-08-01

The use of antimicrobials in production animals has become a worldwide concern in the face of rising resistance levels in commensal, pathogenic and zoonotic bacteria. In the years 2007 and 2008 antimicrobial consumption records were collected during two non consecutive production cycles in 32 randomly selected Belgian broiler farms. Antimicrobials were used in 48 of the 64 monitored production cycles, 7 farms did not use any antimicrobials in both production cycles, 2 farms only administered antimicrobials in one of the two production cycles, the other 23 farms applied antimicrobial treatment in both production cycles. For the quantification of antimicrobial drug use, the treatment incidences (TI) based on the defined daily doses (the dose as it should be applied: DDD) and used daily doses (the actual dose applied: UDD) were calculated. A mean antimicrobial treatment incidence per 1000 animals of 131.8 (standard deviation 126.8) animals treated daily with one DDD and 121.4 (SD 106.7) animals treated daily with one UDD was found. The most frequently used compounds were amoxicillin, tylosin and trimethoprim-sulphonamide with a mean TI(UDD) of 37.9, 34.8, and 21.7, respectively. The ratio of the UDD/DDD gives an estimate on correctness of dosing. Tylosin was underdosed in most of the administrations whereas amoxicillin and trimethoprim-sulphonamide were slightly overdosed in the average flock. Copyright © 2012 Elsevier B.V. All rights reserved.

Cow-specific treatment of clinical mastitis: an economic approach.

Science.gov (United States)

Steeneveld, W; van Werven, T; Barkema, H W; Hogeveen, H

2011-01-01

Under Dutch circumstances, most clinical mastitis (CM) cases of cows on dairy farms are treated with a standard intramammary antimicrobial treatment. Several antimicrobial treatments are available for CM, differing in antimicrobial compound, route of application, duration, and cost. Because cow factors (e.g., parity, stage of lactation, and somatic cell count history) and the causal pathogen influence the probability of cure, cow-specific treatment of CM is often recommended. The objective of this study was to determine if cow-specific treatment of CM is economically beneficial. Using a stochastic Monte Carlo simulation model, 20,000 CM cases were simulated. These CM cases were caused by Streptococcus uberis and Streptococcus dysgalactiae (40%), Staphylococcus aureus (30%), or Escherichia coli (30%). For each simulated CM case, the consequences of using different antimicrobial treatment regimens (standard 3-d intramammary, extended 5-d intramammary, combination 3-d intramammary+systemic, combination 3-d intramammary+systemic+1-d nonsteroidal antiinflammatory drugs, and combination extended 5-d intramammary+systemic) were simulated simultaneously. Finally, total costs of the 5 antimicrobial treatment regimens were compared. Some inputs for the model were based on literature information and assumptions made by the authors were used if no information was available. Bacteriological cure for each individual cow depended on the antimicrobial treatment regimen, the causal pathogen, and the cow factors parity, stage of lactation, somatic cell count history, CM history, and whether the cow was systemically ill. Total costs for each case depended on treatment costs for the initial CM case (including costs for antibiotics, milk withdrawal, and labor), treatment costs for follow-up CM cases, costs for milk production losses, and costs for culling. Average total costs for CM using the 5 treatments were (US) $224, $247, $253, $260, and $275, respectively. Average probabilities

Commercial Essential Oils as Potential Antimicrobials to Treat Skin Diseases

Science.gov (United States)

Orchard, Ané

2017-01-01

Essential oils are one of the most notorious natural products used for medical purposes. Combined with their popular use in dermatology, their availability, and the development of antimicrobial resistance, commercial essential oils are often an option for therapy. At least 90 essential oils can be identified as being recommended for dermatological use, with at least 1500 combinations. This review explores the fundamental knowledge available on the antimicrobial properties against pathogens responsible for dermatological infections and compares the scientific evidence to what is recommended for use in common layman's literature. Also included is a review of combinations with other essential oils and antimicrobials. The minimum inhibitory concentration dilution method is the preferred means of determining antimicrobial activity. While dermatological skin pathogens such as Staphylococcus aureus have been well studied, other pathogens such as Streptococcus pyogenes, Propionibacterium acnes, Haemophilus influenzae, and Brevibacterium species have been sorely neglected. Combination studies incorporating oil blends, as well as interactions with conventional antimicrobials, have shown that mostly synergy is reported. Very few viral studies of relevance to the skin have been made. Encouragement is made for further research into essential oil combinations with other essential oils, antimicrobials, and carrier oils. PMID:28546822

Antimicrobial treatment of infective endocarditis caused by viridans streptococci highly susceptible to penicillin: historic overview and future considerations

NARCIS (Netherlands)

Verhagen, D. W. M.; Vedder, A. C.; Speelman, P.; van der Meer, J. T. M.

2006-01-01

In this article we present the path that led to current concepts regarding antimicrobial treatment of endocarditis caused by viridans streptococci highly susceptible to penicillin. Early treatment trials indicate that some patients with subacute endocarditis can be cured with shorter treatment

The Rising Tide of Antimicrobial Resistance in Aquaculture: Sources, Sinks and Solutions

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Joy E. M. Watts

2017-06-01

Full Text Available As the human population increases there is an increasing reliance on aquaculture to supply a safe, reliable, and economic supply of food. Although food production is essential for a healthy population, an increasing threat to global human health is antimicrobial resistance. Extensive antibiotic resistant strains are now being detected; the spread of these strains could greatly reduce medical treatment options available and increase deaths from previously curable infections. Antibiotic resistance is widespread due in part to clinical overuse and misuse; however, the natural processes of horizontal gene transfer and mutation events that allow genetic exchange within microbial populations have been ongoing since ancient times. By their nature, aquaculture systems contain high numbers of diverse bacteria, which exist in combination with the current and past use of antibiotics, probiotics, prebiotics, and other treatment regimens—singularly or in combination. These systems have been designated as “genetic hotspots” for gene transfer. As our reliance on aquaculture grows, it is essential that we identify the sources and sinks of antimicrobial resistance, and monitor and analyse the transfer of antimicrobial resistance between the microbial community, the environment, and the farmed product, in order to better understand the implications to human and environmental health.

The Rising Tide of Antimicrobial Resistance in Aquaculture: Sources, Sinks and Solutions

Science.gov (United States)

Watts, Joy E. M.; Schreier, Harold J.; Lanska, Lauma; Hale, Michelle S.

2017-01-01

As the human population increases there is an increasing reliance on aquaculture to supply a safe, reliable, and economic supply of food. Although food production is essential for a healthy population, an increasing threat to global human health is antimicrobial resistance. Extensive antibiotic resistant strains are now being detected; the spread of these strains could greatly reduce medical treatment options available and increase deaths from previously curable infections. Antibiotic resistance is widespread due in part to clinical overuse and misuse; however, the natural processes of horizontal gene transfer and mutation events that allow genetic exchange within microbial populations have been ongoing since ancient times. By their nature, aquaculture systems contain high numbers of diverse bacteria, which exist in combination with the current and past use of antibiotics, probiotics, prebiotics, and other treatment regimens—singularly or in combination. These systems have been designated as “genetic hotspots” for gene transfer. As our reliance on aquaculture grows, it is essential that we identify the sources and sinks of antimicrobial resistance, and monitor and analyse the transfer of antimicrobial resistance between the microbial community, the environment, and the farmed product, in order to better understand the implications to human and environmental health. PMID:28587172

antimicrobial properties of some natural and synthetic fabrics modified by radiation treatments

International Nuclear Information System (INIS)

Mohamed, R.M.A.

2008-01-01

natural and synthetic fabrics have been treated with different antimicrobial metal complexes under the effect of gamma radiation . in this regard, cotton, cotton/PET blend and PET were grafted with acrylic acid by gamma radiation and this grafted fabrics were complexed with Cu(ll),Ni(ll)and Co(ll) metal ions . the antimicrobial properties were evaluated by the measurement of tensile strength of fabrics after burring in a soil for one and two weeks as well as the effect of this treatment on the growth of certain bacteria and fungi incubated on a culture for 48 hours. the results showed that the highest protection to cotton, cotton/PET blend and PET fabrics by using Cu(ll) ion in the complexation process, where the order of protection by metals is Cu(ll) > Co(ll)> Ni(ll), moreover, the more grafted fabrics the more complexed fabrics with metal ions and is higher protection against microorganisms . the treatment with the metal ions has nearly no effect on the chemical and physical properties of the natural or the synthetic fabrics as indicated from the analysis by TGA, sem, ion exchange testing and wettability testing.

Impact of broad-spectrum antimicrobial treatment on the ecology of intestinal flora.

Science.gov (United States)

Yang, Jen-Jia; Wang, Jann-Tay; Cheng, Aristine; Chuang, Yu-Chung; Sheng, Wang-Huei

2017-06-28

Suppression of intestinal flora by broad-spectrum antimicrobial agents facilitated risk of colonization or infection with resistant pathogen. We aimed to investigate the changes in bowel carriage of target resistant microorganisms (TRO) among patients treated with three different classes of Pseudomonas-sparing broad-spectrum antimicrobial agents (ertapenem, moxifloxacin and flomoxef) with anaerobic coverage. Risk factors for developing colonization of TRO were also analyzed. We prospectively enrolled the adult hospitalized patients (>20 years old) who were indicated for at least 7-day course with either of ertapenem, moxifloxacin or flomoxef. Rectal swabs were performed for the patients who received at least 1-day course of study antibiotics during the treatment duration. The TROs included Pseudomonas aeruginosa, Enterobacteriaceae, and Acinetobacter baumannii. MacConkey agars with study antibiotics were used to isolate the TROs and evaluate the antimicrobial resistance. The mean age of our study population was 61.6 years, and 58.8% were males. The rates of rectal colonization for Pseudomonas aeruginosa was similar among the study medications (ertapenem 13.2%, flomoxef 20%, moxifloxacin 14.3%, p = 0.809). Compared with ertapenem, flomoxef (odds ratio [OR], 4.30; 95% confidence interval [95% CI], 1.28-14.48, p = 0.019) and moxifloxacin (OR, 6.95; 95% CI, 1.36-35.52, p = 0.019) had higher risk for colonization of ertapenem-resistant Escherichiacoli colonization. The patients who received treatment of ertapenem may have a lower risk of rectal colonization for ertapenem resistant Escherichia coli than those who received flomoxef or moxifloxacin. The rate of Pseudomonas colonization did not differ between the three study Pseudomonas-sparing agents. Copyright © 2017. Published by Elsevier B.V.

Dexamethasone abrogates the antimicrobial and antibiofilm activities of different drugs against clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa

Directory of Open Access Journals (Sweden)

Aquila Rodrigues

2017-01-01

Full Text Available Staphylococcus aureus and Pseudomonas aeruginosa are part of the human microbiota and are also important bacterial pathogens, for which therapeutic options are lacking nowadays. The combined administration of corticosteroids and antimicrobials is commonly used in the treatment of infectious diseases to control inflammatory processes and to minimize potential toxicity of antimicrobials, avoiding sequelae. Although different pharmaceutical dosage forms of antimicrobials combined to corticosteroids are available, studies on the interference of corticosteroids on the pharmacological activity of antimicrobials are scarce and controversial. Here, we provide evidence of the interference of dexamethasone on the pharmacological activity of clinically important antimicrobial drugs against biofilms and planktonic cells of S. aureus and P. aeruginosa. Broth microdilution assays of minimal inhibitory concentration (MIC, minimum bactericidal concentration (MBC, and minimum biofilm eradication concentration (MBEC of gentamicin, chloramphenicol, oxacillin, ceftriaxone and meropenem were conducted with and without the addition of dexamethasone. The effect of all drugs was abrogated by dexamethasone in their MIC, MBC, and MBEC, except gentamicin and meropenem, for which the MBC was not affected in some strains. The present study opens doors for more investigations on in vitro and in vivo effects and safety of the combination of antimicrobials and glucocorticoids.

Efficacy of Local and Systemic Antimicrobials in the Non-Surgical Treatment of Smokers With Chronic Periodontitis: A Systematic Review.

Science.gov (United States)

Chambrone, Leandro; Vargas, Miguel; Arboleda, Silie; Serna, Maritza; Guerrero, Marcela; de Sousa, Jose; Lafaurie, Gloria Inés

2016-11-01

The aim of this systematic review is to evaluate whether use of local or systemic antimicrobials would improve clinical results of non-surgical periodontal therapy for smokers with chronic periodontitis (CP). Medical Literature Analysis and Retrieval System Online, Excerpta Medica Database, and The Cochrane Central Register of Controlled Trials were searched up to and including March 2016. Randomized clinical trials of duration of at least 6 months were included if they reported on treatment of smokers (≥10 cigarettes per day for minimum 12 months) with CP with non-surgical periodontal therapy either alone or associated with local or systemic antimicrobials. Random-effects meta-analyses were undertaken to evaluate mean differences in probing depth (PD) and clinical attachment level (CAL). Of 108 potentially eligible articles, seven were included. Most individual studies (75%) testing locally delivered antibiotics reported that smokers benefited from this treatment approach. Pooled estimates found additional PD reduction of 0.81 mm (P = 0.01) and CAL gain of 0.91 mm (P = 0.01) at sites with baseline PD ≥5 mm. Conversely, meta-analysis on systemic use of antimicrobials failed to detect significant differences in mean changes from baseline, and only one trial supported their use. In smokers with CP, adjunctive use of local antimicrobials improved efficacy of non-surgical periodontal therapy in reducing PD and improving CAL at sites presenting PD ≥5 mm before treatment. Current evidence does not demonstrate similar gains when scaling and root planing plus systemic antimicrobial/antibiotics were associated with therapy.

Antimicrobial activity of Eucalyptus camaldulensis essential oils and their interactions with conventional antimicrobial agents against multi-drug resistant Acinetobacter baumannii.

Science.gov (United States)

Knezevic, Petar; Aleksic, Verica; Simin, Natasa; Svircev, Emilija; Petrovic, Aleksandra; Mimica-Dukic, Neda

2016-02-03

Traditional herbal medicine has become an important issue on the global scale during the past decade. Among drugs of natural origin, special place belongs to essential oils, known as strong antimicrobial agents that can be used to combat antibiotic-resistant bacteria. Eucalyptus camaldulensis leaves are traditional herbal remedy used for various purposes, including treatment of infections. The aim of this study was to determine antimicrobial potential of two E. camaldulensis essential oils against multi-drug resistant (MDR) Acinetobacter baumannii wound isolates and to examine possible interactions of essential oils with conventional antimicrobial agents. Chemical composition of essential oils was determined by gas chromatography-mass spectrometry analysis (GC-MS). MIC values of essential oils against A. baumannii strains were estimated by modified broth microdilution method. The components responsible for antimicrobial activity were detected by bioautographic analysis. The potential synergy between the essential oils and antibiotics (ciprofloxacin, gentamicin and polymyxin B) was examined by checkerboard method and time kill curve. The dominant components of both essential oils were spatulenol, cryptone, p-cimene, 1,8-cineole, terpinen-4-ol and β-pinene. The detected MICs for the E. camaldulensis essential oils were in range from 0.5 to 2 μl mL(-1). The bioautographic assay confirmed antibacterial activity of polar terpene compounds. In combination with conventional antibiotics (ciprofloxacin, gentamicin and polymyxin B), the examined essential oils showed synergistic antibacterial effect in most of the cases, while in some even re-sensitized MDR A. baumannii strains. The synergistic interaction was confirmed by time-kill curves for E. camaldulensis essential oil and polymyxin B combination which reduced bacterial count under detection limit very fast, i.e. after 6h of incubation. The detected anti-A. baumannii activity of E. camaldulensis essential oils

Antimicrobial stewardship: Limits for implementation

NARCIS (Netherlands)

Sinha, Bhanu

2014-01-01

Antibiotic stewardship programme (ASP) is a multifaceted approach to improve patients' clinical outcomes, prevent the emergence of antimicrobial resistance, and reduce hospital costs by prudent and focused antimicrobial use. Development of local treatment guidelines according to local ecology, rapid

Novel food packaging systems with natural antimicrobial agents.

Science.gov (United States)

Irkin, Reyhan; Esmer, Ozlem Kizilirmak

2015-10-01

A new type of packaging that combines food packaging materials with antimicrobial substances to control microbial surface contamination of foods to enhance product microbial safety and to extend shelf-life is attracting interest in the packaging industry. Several antimicrobial compounds can be combined with different types of packaging materials. But in recent years, since consumer demand for natural food ingredients has increased because of safety and availability, these natural compounds are beginning to replace the chemical additives in foods and are perceived to be safer and claimed to alleviate safety concerns. Recent research studies are mainly focused on the application of natural antimicrobials in food packaging system. Biologically derived compounds like bacteriocins, phytochemicals, enzymes can be used in antimicrobial food packaging. The aim of this review is to give an overview of most important knowledge about application of natural antimicrobial packagings with model food systems and their antimicrobial effects on food products.

Comparative evaluation of antimicrobials for textile applications.

Science.gov (United States)

Windler, Lena; Height, Murray; Nowack, Bernd

2013-03-01

Many antimicrobial technologies are available for textiles. They may be used in many different textile applications to prevent the growth of microorganisms. Due to the biological activity of the antimicrobial compounds, the assessment of the safety of these substances is an ongoing subject of research and regulatory scrutiny. This review aims to give an overview on the main compounds used today for antimicrobial textile functionalization. Based on an evaluation of scientific publications, market data as well as regulatory documents, the potential effects of antimicrobials on the environment and on human health were considered and also life cycle perspectives were taken into account. The characteristics of each compound were summarized according to technical, environmental and human health criteria. Triclosan, silane quaternary ammonium compounds, zinc pyrithione and silver-based compounds are the main antimicrobials used in textiles. The synthetic organic compounds dominate the antimicrobials market on a weight basis. On the technical side the application rates of the antimicrobials used to functionalize a textile product are an important parameter with treatments requiring lower dosage rates offering clear benefits in terms of less active substance required to achieve the functionality. The durability of the antimicrobial treatment has a strong influence on the potential for release and subsequent environmental effects. In terms of environmental criteria, all compounds were rated similarly in effective removal in wastewater treatment processes. The extent of published information about environmental behavior for each compound varies, limiting the possibility for an in-depth comparison of all textile-relevant parameters across the antimicrobials. Nevertheless the comparative evaluation showed that each antimicrobial technology has specific risks and benefits that should be taken into account in evaluating the suitability of different antimicrobial products. The

Antimicrobial Lemongrass Essential Oil—Copper Ferrite Cellulose Acetate Nanocapsules

Directory of Open Access Journals (Sweden)

Ioannis L. Liakos

2016-04-01

Full Text Available Cellulose acetate (CA nanoparticles were combined with two antimicrobial agents, namely lemongrass (LG essential oil and Cu-ferrite nanoparticles. The preparation method of CA nanocapsules (NCs, with the two antimicrobial agents, was based on the nanoprecipitation method using the solvent/anti-solvent technique. Several physical and chemical analyses were performed to characterize the resulting NCs and to study their formation mechanism. The size of the combined antimicrobial NCs was found to be ca. 220 nm. The presence of Cu-ferrites enhanced the attachment of LG essential oil into the CA matrix. The magnetic properties of the combined construct were weak, due to the shielding of Cu-ferrites from the polymeric matrix, making them available for drug delivery applications where spontaneous magnetization effects should be avoided. The antimicrobial properties of the NCs were significantly enhanced with respect to CA/LG only. This work opens novel routes for the development of organic/inorganic nanoparticles with exceptional antimicrobial activities.

Antimicrobial Lemongrass Essential Oil-Copper Ferrite Cellulose Acetate Nanocapsules.

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Liakos, Ioannis L; Abdellatif, Mohamed H; Innocenti, Claudia; Scarpellini, Alice; Carzino, Riccardo; Brunetti, Virgilio; Marras, Sergio; Brescia, Rosaria; Drago, Filippo; Pompa, Pier Paolo

2016-04-20

Cellulose acetate (CA) nanoparticles were combined with two antimicrobial agents, namely lemongrass (LG) essential oil and Cu-ferrite nanoparticles. The preparation method of CA nanocapsules (NCs), with the two antimicrobial agents, was based on the nanoprecipitation method using the solvent/anti-solvent technique. Several physical and chemical analyses were performed to characterize the resulting NCs and to study their formation mechanism. The size of the combined antimicrobial NCs was found to be ca. 220 nm. The presence of Cu-ferrites enhanced the attachment of LG essential oil into the CA matrix. The magnetic properties of the combined construct were weak, due to the shielding of Cu-ferrites from the polymeric matrix, making them available for drug delivery applications where spontaneous magnetization effects should be avoided. The antimicrobial properties of the NCs were significantly enhanced with respect to CA/LG only. This work opens novel routes for the development of organic/inorganic nanoparticles with exceptional antimicrobial activities.

Antimicrobial Treatment of Polymeric Medical Devices by Silver Nanomaterials and Related Technology.

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Polívková, Markéta; Hubáček, Tomáš; Staszek, Marek; Švorčík, Václav; Siegel, Jakub

2017-02-15

Antimicrobial biocompatible polymers form a group of highly desirable materials in medicinal technology that exhibit interesting thermal and mechanical properties, and high chemical resistance. There are numerous types of polymers with antimicrobial activity or antimicrobial properties conferred through their proper modification. In this review, we focus on the second type of polymers, especially those whose antimicrobial activity is conferred by nanotechnology. Nanotechnology processing is a developing area that exploits the antibacterial effects of broad-scale compounds, both organic and inorganic, to form value-added medical devices. This work gives an overview of nanostructured antimicrobial agents, especially silver ones, used together with biocompatible polymers as effective antimicrobial composites in healthcare. The bactericidal properties of non-conventional antimicrobial agents are compared with those of conventional ones and the advantages and disadvantages are discussed.

Antimicrobial Treatment of Polymeric Medical Devices by Silver Nanomaterials and Related Technology

Directory of Open Access Journals (Sweden)

Markéta Polívková

2017-02-01

Full Text Available Antimicrobial biocompatible polymers form a group of highly desirable materials in medicinal technology that exhibit interesting thermal and mechanical properties, and high chemical resistance. There are numerous types of polymers with antimicrobial activity or antimicrobial properties conferred through their proper modification. In this review, we focus on the second type of polymers, especially those whose antimicrobial activity is conferred by nanotechnology. Nanotechnology processing is a developing area that exploits the antibacterial effects of broad-scale compounds, both organic and inorganic, to form value-added medical devices. This work gives an overview of nanostructured antimicrobial agents, especially silver ones, used together with biocompatible polymers as effective antimicrobial composites in healthcare. The bactericidal properties of non-conventional antimicrobial agents are compared with those of conventional ones and the advantages and disadvantages are discussed.

Antimicrobial Peptides in 2014

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Guangshun Wang

2015-03-01

Full Text Available This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms.

Underlying mechanism of antimicrobial activity of chitosan microparticles and implications for the treatment of infectious diseases.

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Soo Jin Jeon

Full Text Available The emergence of antibiotic resistant microorganisms is a great public health concern and has triggered an urgent need to develop alternative antibiotics. Chitosan microparticles (CM, derived from chitosan, have been shown to reduce E. coli O157:H7 shedding in a cattle model, indicating potential use as an alternative antimicrobial agent. However, the underlying mechanism of CM on reducing the shedding of this pathogen remains unclear. To understand the mode of action, we studied molecular mechanisms of antimicrobial activity of CM using in vitro and in vivo methods. We report that CM are an effective bactericidal agent with capability to disrupt cell membranes. Binding assays and genetic studies with an ompA mutant strain demonstrated that outer membrane protein OmpA of E. coli O157:H7 is critical for CM binding, and this binding activity is coupled with a bactericidal effect of CM. This activity was also demonstrated in an animal model using cows with uterine diseases. CM treatment effectively reduced shedding of intrauterine pathogenic E. coli (IUPEC in the uterus compared to antibiotic treatment. Since Shiga-toxins encoded in the genome of bacteriophage is often overexpressed during antibiotic treatment, antibiotic therapy is generally not recommended because of high risk of hemolytic uremic syndrome. However, CM treatment did not induce bacteriophage or Shiga-toxins in E. coli O157:H7; suggesting that CM can be a potential candidate to treat infections caused by this pathogen. This work establishes an underlying mechanism whereby CM exert antimicrobial activity in vitro and in vivo, providing significant insight for the treatment of diseases caused by a broad spectrum of pathogens including antibiotic resistant microorganisms.

Antimicrobial effect and shelf-life extension by combined thermal and pulsed electric field treatment of milk.

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Walkling-Ribeiro, M; Noci, F; Cronin, D A; Lyng, J G; Morgan, D J

2009-01-01

The impact of a combined hurdle treatment of heat and pulsed electric fields (PEF) was studied on native microbiota used for the inoculation of low-fat ultra-high temperature (UHT) milk and whole raw milk. Microbiological shelf-life of the latter following hurdle treatment or thermal pasteurization was also investigated. UHT milk was preheated to 30 degrees C, 40 degrees C or 50 degrees C over a 60-s period, pulsed for 50 micros or 60 micros at a field strength of 40 kV cm(-1) or for 33 micros at 50 kV cm(-1). Heat and PEF reduced the microbial count by a maximum of 6.4 log in UHT milk (50 degrees C; 50 kV cm(-1), 33 micros) compared to 6.0 log (P > or = 0.05) obtained by thermal pasteurization (26 s, 72 degrees C). When raw milk was treated with a combination of hurdles (50 degrees C; 40 kV cm(-1), 60 micros) a 6.0 log inactivation of microbiota was achieved and microbiological milk shelf-life was extended to 21 days under refrigeration (4 degrees C) vs 14 days in thermally pasteurized milk. Native microbiota was decreased by 6.7 log following conventional pasteurization. The findings suggest that heat and PEF achieved similar inactivation of native microbiota in milk and longer stabilization of microbiological shelf-life than thermal pasteurization. A hurdle approach of heat and PEF could represent a valid milk processing alternative to conventional pasteurization. Hurdle treatment might also preserve native milk quality better due to less thermal exposure.

In vitro pharmacokinetics of antimicrobial cationic peptides alone and in combination with antibiotics against methicillin resistant Staphylococcus aureus biofilms.

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Dosler, Sibel; Mataraci, Emel

2013-11-01

Antibiotic therapy for methicillin-resistant Staphylococcus aureus (MRSA) infections is becoming more difficult in hospitals and communities because of strong biofilm-forming properties and multidrug resistance. Biofilm-associated MRSA is not affected by therapeutically achievable concentrations of antibiotics. Therefore, we investigated the in vitro pharmacokinetic activities of antimicrobial cationic peptides (AMPs; indolicidin, cecropin [1-7]-melittin A [2-9] amide [CAMA], and nisin), either alone or in combination with antibiotics (daptomycin, linezolid, teicoplanin, ciprofloxacin, and azithromycin), against standard and 2 clinically obtained MRSA biofilms. The minimum inhibitory concentrations (MIC) and minimum biofilm-eradication concentrations (MBEC) were determined by microbroth dilution technique. The time-kill curve (TKC) method was used to determine the bactericidal activities of the AMPs alone and in combination with the antibiotics against standard and clinically obtained MRSA biofilms. The MIC values of the AMPs and antibiotics ranged between 2 to 16 and 0.25 to 512 mg/L, and their MBEC values were 640 and 512 to 5120 mg/L, respectively. The TKC studies demonstrated that synergistic interactions occurred most frequently when using nisin+daptomycin/ciprofloxacin, indolicidin+teicoplanin, and CAMA+ciprofloxacin combinations. No antagonism was observed with any combination. AMPs appear to be good candidates for the treatment of MRSA biofilms, as they act as both enhancers of anti-biofilm activities and help to prevent or delay the emergence of resistance when used either alone or in combination with antibiotics. Copyright © 2013 Elsevier Inc. All rights reserved.

Tolerance to the antimicrobial peptide colistin in Pseudomonas aeruginosa biofilms is linked to metabolically active cells, and depends on the pmr and mexAB-oprM genes

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Pamp, Sünje Johanna; Gjermansen, Morten; Johansen, Helle Krogh

2008-01-01

-mediated killing in biofilms, conventional antimicrobial compounds such as ciprofloxacin and tetracycline were found to specifically kill the subpopulation of metabolically active biofilm cells, whereas the subpopulation exhibiting low metabolic activity survived the treatment. Consequently, targeting the two...... physiologically distinct subpopulations by combined antimicrobial treatment with either ciprofloxacin and colistin or tetracycline and colistin almost completely eradicated all biofilm cells....

Antimicrobial Activity and Modulatory Effect of Essential Oil from the Leaf of Rhaphiodon echinus (Nees & Mart) Schauer on Some Antimicrobial Drugs.

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Duarte, Antonia Eliene; de Menezes, Irwin Rose Alencar; Bezerra Morais Braga, Maria Flaviana; Leite, Nadghia Figueiredo; Barros, Luiz Marivando; Waczuk, Emily Pansera; Pessoa da Silva, Maria Arlene; Boligon, Aline; Teixeira Rocha, João Batista; Souza, Diogo Onofre; Kamdem, Jean Paul; Melo Coutinho, Henrique Douglas; Escobar Burger, Marilise

2016-06-08

Rhaphiodon echinus is a weed plant used in the Brazilian folk medicinal for the treatment of infectious diseases. In this study, the essential oil of R. echinus leaf was investigated for its antimicrobial properties. The chemical constituents of the essential oil were characterized by GC-MS. The antimicrobial properties were determined by studying by the microdilution method the effect of the oil alone, and in combination with antifungal or antibiotic drugs against the fungi Candida albicans, Candida krusei and Candida tropicalis and the microbes Escherichia coli, Staphylococcus aureus and Pseudomonas. In addition, the iron (II) chelation potential of the oil was determined. The results showed the presence of β-caryophyllene and bicyclogermacrene in major compounds, and revealed a low antifungal and antibacterial activity of the essential oil, but a strong modulatory effect on antimicrobial drugs when associated with the oil. The essential oil showed iron (II) chelation activity. The GC-MS characterization revealed the presence of monoterpenes and sesquiterpenes in the essential oil and metal chelation potential, which may be responsible in part for the modulatory effect of the oil. These findings suggest that essential oil of R. echinus is a natural product capable of enhancing the antibacterial and antifungal activity of antimicrobial drugs.

Antimicrobial drugs for treating cholera.

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Leibovici-Weissman, Ya'ara; Neuberger, Ami; Bitterman, Roni; Sinclair, David; Salam, Mohammed Abdus; Paul, Mical

2014-06-19

Cholera is an acute watery diarrhoea caused by infection with the bacterium Vibrio cholerae, which if severe can cause rapid dehydration and death. Effective management requires early diagnosis and rehydration using oral rehydration salts or intravenous fluids. In this review, we evaluate the additional benefits of treating cholera with antimicrobial drugs. To quantify the benefit of antimicrobial treatment for patients with cholera, and determine whether there are differences between classes of antimicrobials or dosing schedules. We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; African Index Medicus; LILACS; Science Citation Index; metaRegister of Controlled Trials; WHO International Clinical Trials Registry Platform; conference proceedings; and reference lists to March 2014. Randomized and quasi-randomized controlled clinical trials in adults and children with cholera that compared: 1) any antimicrobial treatment with placebo or no treatment; 2) different antimicrobials head-to-head; or 3) different dosing schedules or different durations of treatment with the same antimicrobial. Two reviewers independently applied inclusion and exclusion criteria, and extracted data from included trials. Diarrhoea duration and stool volume were defined as primary outcomes. We calculated mean difference (MD) or ratio of means (ROM) for continuous outcomes, with 95% confidence intervals (CI), and pooled data using a random-effects meta-analysis. The quality of evidence was assessed using the GRADE approach. Thirty-nine trials were included in this review with 4623 participants. Antimicrobials versus placebo or no treatment Overall, antimicrobial therapy shortened the mean duration of diarrhoea by about a day and a half compared to placebo or no treatment (MD -36.77 hours, 95% CI -43.51 to -30.03, 19 trials, 1013 participants, moderate quality evidence). Antimicrobial therapy also

Evaluation of the decision support system for antimicrobial treatment, TREAT, in an acute medical ward of a university hospital

DEFF Research Database (Denmark)

Arboe, Bente; Laub, Rasmus Rude; Kronborg, Gitte

2014-01-01

OBJECTIVES: TREAT, a decision support system for antimicrobial therapy, was implemented in an acute medical ward. METHODS: Patients admitted on suspicion of infection were included in the study. The evaluation of TREAT was done both retrospectively and prospectively. Coverage of empirical...... antimicrobial treatments was compared to recommendations from TREAT and the optimal use of local guidelines. RESULTS: Five hundred and eleven patients were included, of whom 162 had a microbiologically documented infection. In the retrospective part of the study, TREAT, physician, and guideline antimicrobial.......247). The coverage of TREAT advice for the bacteraemia patients was non-inferior to the physicians (p=1.00). CONCLUSIONS: TREAT can potentially improve the ecological costs of empirical antimicrobial therapy for patients in acute medical wards, but provided lower coverage than local guidelines....

Combined physico-chemical treatments based on enterocin AS-48 for inactivation of Gram-negative bacteria in soybean sprouts.

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Cobo Molinos, Antonio; Abriouel, Hikmate; López, Rosario Lucas; Valdivia, Eva; Omar, Nabil Ben; Gálvez, Antonio

2008-08-01

Enterocin AS-48 was tested for decontamination of soybean sprouts against Gram-negative bacteria. Although treatment with bacteriocin alone had no effect on Salmonella enterica, a synergistic antimicrobial effect was detected at pH 9.0 and in combination with moderate heat treatment. Greatest inactivation was achieved for sprouts heated for 5 min at 65 degrees C in an alkaline (pH 9.0) enterocin AS-48 solution of 25 microg/ml. Bactericidal activity against S. enterica increased greatly when enterocin AS-48 was used in washing solutions in combination with several chemical compounds: EDTA, lactic acid, peracetic acid, polyphosphoric acid, sodium hypochlorite, hexadecylpyridinium chloride, propyl-p-hydroxybenzoate, and hydrocinnamic acid. The combined treatment of enterocin AS-48 and polyphosphoric acid was tested against several other Gram-negative bacteria inoculated on sprouts. The bacteria tested showed great differences in sensitivity to polyphosphoric acid, but synergism with enterocin AS-48 was confirmed in all cases. Combinations of enterocin AS-48 (25 microg/ml) and polyphosphoric acid in a concentration range of 0.1 to 2.0% significantly reduced or inhibited growth of the populations of S. enterica, Escherichia coli O157:H7, Shigella spp., Enterobacter aerogenes, Yersinia enterocolitica, Aeromonas hydrophila and Pseudomonas fluorescens in sprout samples stored at 6 degrees C and 15 degrees C. The combined treatment could therefore be applied to reduce the risks of Gram-negative pathogenic as well as spoilage bacteria on sprouts.

Antimicrobial use and antimicrobial susceptibility in Escherichia coli on small- and medium-scale pig farms in north-eastern Thailand

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G. Ström

2017-07-01

Full Text Available Abstract Background Intensification of livestock production seen in many low- and middle-income countries is often believed to be associated with increased use of antimicrobials, and may hence contribute to the emergence of antimicrobial resistance. The aim of this study was to map antimicrobial use on small- (n = 25 and medium-scale (n = 27 pig farms in north-eastern Thailand, and to compare antimicrobial susceptibility of commensal Escherichia coli isolated from sows on these farms. Methods Information regarding pig husbandry and antimicrobial treatment regimens was obtained by the use of semi-structured questionnaires. Faecal samples were collected from three healthy sows at each farm, and Escherichia coli was cultured and analysed for antimicrobial susceptibility using the broth microdilution method. Multilevel regression models were used to compare antimicrobial susceptibility between isolates from small- and medium-scale farms. Results All farms included in the study administered antimicrobials to their sows. Small-scale farmers most commonly (64% decided themselves when to give antimicrobials and the majority (60% bought the medicines at the local store or pharmacy, whereas farmers on medium-scale farms always discussed antimicrobial treatment with a veterinarian. Medium-scale farms used a greater diversity of antimicrobials than small-scale farms and did also administer antimicrobials in feed to a higher extent. High levels of antimicrobial resistance to several critically important antimicrobials for human medicine (including ciprofloxacin, streptomycin and ampicillin were found in isolates from both small- and medium-scale farms. Resistance levels were significantly (P < 0.05 higher in isolates from medium-scale farms for several of the antimicrobials tested, as well as the level of multidrug-resistance (P = 0.026. Conclusion The routines regarding access and administration of antimicrobials differed between the small- and

Effect of mixed antimicrobial agents and flavors in active packaging films.

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Gutiérrez, Laura; Escudero, Ana; Batlle, Ramón; Nerín, Cristina

2009-09-23

Active packaging is an emerging food technology to improve the quality and safety of food products. Many works have been developed to study the antimicrobial activity of essential oils. Essential oils have been traditionally used as flavorings in food, so they have an important odor impact but they have as well antimicrobial properties that could be used to protect the food. Recent developments in antimicrobial active packaging showed the efficiency of essential oils versus bread and bakery products among other applications. However, one of the main problems to face is the odor and taste they could provide to the packaged food. Using some aromas to mask the odor could be a good approach. That is why the main objective of this paper is to develop an antimicrobial packaging material based on the combination of the most active compounds of essential oils (hydrocinnamaldehyde, oregano essential oil, cinnamaldehyde, thymol, and carvacrol) together with some aromas commonly used in the food industry. A study of the concentration required to get the antimicrobial properties, the organoleptic compatibility with typical aroma present in many food systems (vanilla, banana, and strawberry), and the right combination of both systems has been carried out. Antimicrobial tests of both the mentioned aromas, the main components of some essential oils, and the combination of both groups were carried out against bacteria (Enterococcus faecalis, Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Salmonella choleraesuis, Yersinia enterocolitica, Escherichia coli), yeasts (Candida albicans, Debaryomyces hansenii, Zygosaccharomyces rouxii), and molds (Botrytis cinerae, Aspergillus flavus, Penicillium roqueforti, Eurotium repens, Penicillium islandicum, Penicillium commune, Penicillium nalgiovensis). The sensory properties of the combinations were evaluated with a triangular test and classification was by an order test; the odor threshold of the aroma compounds was also

Antidepressants, antimicrobials or both? Gut microbiota dysbiosis in depression and possible implications of the antimicrobial effects of antidepressant drugs for antidepressant effectiveness.

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Macedo, Danielle; Filho, Adriano José Maia Chaves; Soares de Sousa, Caren Nádia; Quevedo, João; Barichello, Tatiana; Júnior, Hélio Vitoriano Nobre; Freitas de Lucena, David

2017-01-15

The first drug repurposed for the treatment of depression was the tuberculostatic iproniazid. At present, drugs belonging to new classes of antidepressants still have antimicrobial effects. Dysbiosis of gut microbiota was implicated in the development or exacerbation of mental disorders, such as major depressive disorder (MDD). Based on the current interest in the gut-brain axis, the focus of this narrative review is to compile the available studies regarding the influences of gut microbiota in behavior and depression and to show the antimicrobial effect of antidepressant drugs. A discussion regarding the possible contribution of the antimicrobial effect of antidepressant drugs to its effectiveness/resistance is included. The search included relevant articles from PubMed, SciELO, LILACS, PsycINFO, and ISI Web of Knowledge. MDD is associated with changes in gut permeability and microbiota composition. In this respect, antidepressant drugs present antimicrobial effects that could also be related to the effectiveness of these drugs for MDD treatment. Conversely, some antimicrobials present antidepressant effects. Both antidepressants and antimicrobials present neuroprotective/antidepressant and antimicrobial effects. Further studies are needed to evaluate the participation of antimicrobial mechanisms of antidepressants in MDD treatment as well as to determine the contribution of this effect to antidepressant resistance. Copyright © 2016 Elsevier B.V. All rights reserved.

Antimicrobial evaluation of plants used for the treatment of diarrhoea in a rural community in northern Maputaland, KwaZulu-Natal, South Africa.

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van Vuuren, Sandy F; Nkwanyana, Mduduzi N; de Wet, Helene

2015-03-10

Zulu people living in the rural area of Maputaland (KwaZulu-Natal, South Africa) rely heavily on medicinal plants for the treatment of diarrhoea. Abundant availability of medicinal plants in the study area offers low cost health care, but scientific validation is needed in order to lend credibility to the traditional use against many ailments including diarrhoeal infections. With this in mind a study was designed to test the in vitro antimicrobial efficacy of 23 plant species which are used for the treatment of diarrhoea in rural Maputaland. Four 1:1 plant combinations were also evaluated to determine their interactive effects against seven diarrhoea-related bacterial pathogens. Minimum inhibitory concentration (MIC) assays were undertaken on dichloromethane-methanol (CH2Cl2: MeOH) and aqueous crude extracts. The following micro-organisms were selected for this study and were tested based on their association with stomach ailments and diarrhoea; Bacillus cereus (ATCC 11778), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 8739), Proteus vulgaris (ATCC 33420), Salmonella typhimurium (ATCC 14028), Shigella flexneri (ATCC 25875) and Staphylococcus aureus (ATCC 12600). The fractional inhibitory concentration index (ΣFIC) was determined for plants traditionally used in combination. Shigella flexneri proved to be the most susceptible pathogen, where the organic extract of Terminalia sericea showed the most prominent noteworthy antibacterial activity (mean MIC value of 0.04 mg/mL). The aqueous extracts generally showed poorer antimicrobial activity with some exceptions i.e. Acacia burkei, Brachylaena transvaalensis against B. cereus and B. transvaalensis against S. flexneri. In the combination studies, synergy was predominant with mean (across all pathogens) ΣFIC values of 0.30 for Acanthospermum glabratum with Krauseola mosambicina; ΣFIC values of 0.46 for A. glabratum with Psidium guajava; ΣFIC values of 0.39 for B. transvaalensis with P. guajava and �

Exploring Post-Treatment Reversion of Antimicrobial Resistance in Enteric Bacteria of Food Animals as a Resistance Mitigation Strategy.

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Volkova, Victoriya V; KuKanich, Butch; Riviere, Jim E

2016-11-01

Antimicrobial drug use in food animals is associated with an elevation in relative abundance of bacteria resistant to the drug among the animal enteric bacteria. Some of these bacteria are potential foodborne pathogens. Evidence suggests that at least in the enteric nontype-specific Escherichia coli, after treatment the resistance abundance reverts to the background pre-treatment levels, without further interventions. We hypothesize that it is possible to define the distribution of the time period after treatment within which resistance to the administered drug, and possibly other drugs in case of coselection, in fecal bacteria of the treated animals returns to the background pre-treatment levels. Furthermore, it is possible that a novel resistance mitigation strategy for microbiological food safety could be developed based on this resistance reversion phenomenon. The strategy would be conceptually similar to existing antimicrobial drug withdrawal periods, which is a well-established and accepted mitigation strategy for avoiding violative drug residues in the edible products from the treated animals. For developing resistance-relevant withdrawals, a mathematical framework can be used to join the necessary pharmacological, microbiological, and animal production components to project the distributions of the post-treatment resistance reversion periods in the production animal populations for major antimicrobial drug classes in use. The framework can also help guide design of empirical studies into the resistance-relevant withdrawal periods and development of mitigation approaches to reduce the treatment-associated elevation of resistance in animal enteric bacteria. We outline this framework, schematically and through exemplar equations, and how its components could be formulated.

Invited review: A systematic review and qualitative analysis of treatments other than conventional antimicrobials for clinical mastitis in dairy cows.

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Francoz, D; Wellemans, V; Dupré, J P; Roy, J P; Labelle, F; Lacasse, P; Dufour, S

2017-10-01

Clinical mastitis is an important disease in dairies. Its treatment is mainly based on the use of antimicrobial drugs. Numerous non-antimicrobial drugs and treatment strategies have already been reported for clinical mastitis treatment, but data on their efficacy have never been collated in a systematic way. The objective of this systematic review was to identify treatments other than conventional antimicrobials for the treatment of clinical mastitis in lactating dairy cows. A systematic review was performed with studies written in English or French selected from CAB Abstracts, PubMed, and Web of Science from January 1970 to June 2014. Controlled clinical trials, observational studies, and experimental challenges were retained. Lactating dairy cows with clinical mastitis were the participant of interest. All treatments other than conventional antimicrobials for clinical mastitis during lactation were retained. Only studies comparing the treatment under investigation to a negative or positive control, or both, were included. Outcomes evaluated were clinical and bacteriological cure rates and milk production. Selection of the study, data extraction, and assessment of risk of bias was performed by 3 reviewers. Assessment of risk of bias was evaluated using the Cochrane Collaboration tool for systematic review of interventions. A total of 2,451 manuscripts were first identified and 39 manuscripts corresponding to 41 studies were included. Among these, 22 were clinical trials, 18 were experimental studies, and 1 was an observational study. The treatments evaluated were conventional anti-inflammatory drugs (n = 14), oxytocin with or without frequent milk out (n = 5), biologics (n = 9), homeopathy (n = 5), botanicals (n = 4), probiotics (n = 2), and other alternative products (n = 2). All trials had at least one unclear or high risk of bias. Most trials (n = 13) did not observe significant differences in clinical or bacteriological cure rates in comparison with negative

Stepwise impact of urban wastewater treatment on the bacterial community structure, antibiotic contents, and prevalence of antimicrobial resistance.

Science.gov (United States)

Wang, Mingyu; Shen, Weitao; Yan, Lei; Wang, Xin-Hua; Xu, Hai

2017-12-01

Bacteria, antibiotics, and antibiotic resistance determinants are key biological pollutants in aquatic systems, which may lead to bacterial infections or prevent the cure of bacterial infections. In this study, we investigated how the wastewater treatment processes in wastewater treatment plants (WWTPs) affect these pollutants. We found that the addition of oxygen, polyaluminum chloride (PAC), and polyacrylamide (PAM), as well as ultraviolet (UV) disinfection could significantly alter the bacterial communities in the water samples. An overall shift from Gram-negative bacteria to Gram-positive bacteria was observed throughout the wastewater treatment steps, but the overall bacterial biomass was not reduced in the WWTP samples. The antibiotic contents were reduced by the WWTP, but the size of the reduction and the step when antibiotic degradation occurred differed among antibiotics. Ciprofloxacin, sulfamethoxazole and erythromycin could be removed completely by the WWTP, whereas cephalexin could not. The removal of ciprofloxacin, cephalexin, and erythromycin occurred in the anaerobic digester, whereas the removal of sulfamethoxazole occurred after the addition of PAC and PAM, and UV disinfection. Antimicrobial resistance determinants were highly prevalent in all of the samples analyzed, except for those targeting vancomycin and colistin. However, wastewater treatment was ineffective at removing antimicrobial resistance determinants from wastewater. There were strong correlations between intI1, floR, sul1, and ermB, thereby suggesting the importance of integrons for the spread of these antimicrobial resistance genes. In general, this study comprised a stepwise analysis of the impact of WWTPs on three biological pollutants: bacteria, antibiotics, and antimicrobial resistance determinants, where our results suggest that the design of WWTPs needs to be improved to address the threats due to these pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antimicrobial properties of analgesic kyotorphin peptides unraveled through atomic force microscopy

International Nuclear Information System (INIS)

Ribeiro, Marta M.B.; Franquelim, Henri G.; Torcato, Inês M.; Ramu, Vasanthakumar G.; Heras, Montserrat; Bardaji, Eduard R.; Castanho, Miguel A.R.B.

2012-01-01

Highlights: ► New kyotorphin derivatives have antimicrobial properties against S. aureus. ► Atomic force microscopy show membrane disturbing effects of KTP–NH 2 and IbKTP–NH 2 . ► None of the KTP derivatives are hemolytic. ► The minimal peptidic sequence with antimicrobial activity is Tyr-Arg, if amidated. -- Abstract: Antimicrobial peptides (AMPs) are promising candidates as alternatives to conventional antibiotics for the treatment of resistant pathogens. In the last decades, new AMPs have been found from the cleavage of intact proteins with no antibacterial activity themselves. Bovine hemoglobin hydrolysis, for instance, results in AMPs and the minimal antimicrobial peptide sequence was defined as Tyr-Arg plus a positively charged amino acid residue. The Tyr-Arg dipeptide alone, known as kyotorphin (KTP), is an endogenous analgesic neuropeptide but has no antimicrobial activity itself. In previous studies new KTP derivatives combining C-terminal amidation and Ibuprofen (Ib) – KTP–NH 2 , IbKTP, IbKTP–NH 2 – were designed in order to improve KTP brain targeting. Those modifications succeeded in enhancing peptide-cell membrane affinity towards fluid anionic lipids and higher analgesic activity after systemic injection resulted therefrom. Here, we investigated if this affinity for anionic lipid membranes also translates into antimicrobial activity because bacteria have anionic membranes. Atomic force microscopy revealed that KTP derivatives perturbed Staphylococcus aureus membrane structure by inducing membrane blebbing, disruption and lysis. In addition, these peptides bind to red blood cells but are non-hemolytic. From the KTP derivatives tested, amidated KTP proves to be the most active antibacterial agent. The combination of analgesia and antibacterial activities with absence of toxicity is highly appealing from the clinical point of view and broadens the therapeutic potential and application of kyotorphin peptides.

Antimicrobial properties of analgesic kyotorphin peptides unraveled through atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, Marta M.B.; Franquelim, Henri G.; Torcato, Ines M. [Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Av. Professor Egas Moniz, 1649-028 Lisboa (Portugal); Ramu, Vasanthakumar G.; Heras, Montserrat; Bardaji, Eduard R. [Laboratori d' Innovacio en Processos i Productes de Sintesi Organica (LIPPSO), Departament de Quimica, Universitat de Girona, Campus Montilivi, 17071 Girona (Spain); Castanho, Miguel A.R.B., E-mail: macastanho@fm.ul.pt [Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Av. Professor Egas Moniz, 1649-028 Lisboa (Portugal)

2012-04-13

Highlights: Black-Right-Pointing-Pointer New kyotorphin derivatives have antimicrobial properties against S. aureus. Black-Right-Pointing-Pointer Atomic force microscopy show membrane disturbing effects of KTP-NH{sub 2} and IbKTP-NH{sub 2}. Black-Right-Pointing-Pointer None of the KTP derivatives are hemolytic. Black-Right-Pointing-Pointer The minimal peptidic sequence with antimicrobial activity is Tyr-Arg, if amidated. -- Abstract: Antimicrobial peptides (AMPs) are promising candidates as alternatives to conventional antibiotics for the treatment of resistant pathogens. In the last decades, new AMPs have been found from the cleavage of intact proteins with no antibacterial activity themselves. Bovine hemoglobin hydrolysis, for instance, results in AMPs and the minimal antimicrobial peptide sequence was defined as Tyr-Arg plus a positively charged amino acid residue. The Tyr-Arg dipeptide alone, known as kyotorphin (KTP), is an endogenous analgesic neuropeptide but has no antimicrobial activity itself. In previous studies new KTP derivatives combining C-terminal amidation and Ibuprofen (Ib) - KTP-NH{sub 2}, IbKTP, IbKTP-NH{sub 2} - were designed in order to improve KTP brain targeting. Those modifications succeeded in enhancing peptide-cell membrane affinity towards fluid anionic lipids and higher analgesic activity after systemic injection resulted therefrom. Here, we investigated if this affinity for anionic lipid membranes also translates into antimicrobial activity because bacteria have anionic membranes. Atomic force microscopy revealed that KTP derivatives perturbed Staphylococcus aureus membrane structure by inducing membrane blebbing, disruption and lysis. In addition, these peptides bind to red blood cells but are non-hemolytic. From the KTP derivatives tested, amidated KTP proves to be the most active antibacterial agent. The combination of analgesia and antibacterial activities with absence of toxicity is highly appealing from the clinical point of view

Antimicrobial stewardship: Strategies for a global response

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Jenny Grunwald

2014-01-01

Full Text Available The increasing antimicrobial resistance worldwide, combined with dwindling antimicrobial armamentarium, has resulted in a critical threat to the public health and safety of patients. To combat this hazard, antimicrobial stewardship programs (ASPs have emerged. Antimicrobial stewardship programs prevent or slow the emergence of antimicrobial resistance by coordinated interventions designed to optimize antimicrobial use to achieve the best clinical outcomes and limiting selective pressures that drive the emergence of resistance. This also reduces excessive costs attributable to suboptimal antimicrobial use. Even though an ideal effective ASP should incorporate more than one element simultaneously, it also requires a multidisciplinary team, which should include an infectious diseases physician, a clinical pharmacist with infectious diseases training, infection control professionals, hospital epidemiologist, a clinical microbiologist and an information specialist. However, for antimicrobial stewardship (AMS programs to be successful, they must address the specific needs of individual institutions, must be built on available resources, the limitations and advantages of each institution, and the available staffing and technological infrastructure.

The effect of adding antimicrobial peptides to milk inoculated with Staphylococcus aureus and processed by high-intensity pulsed-electric field.

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Sobrino-Lopez, A; Viedma-Martínez, P; Abriouel, H; Valdivia, E; Gálvez, A; Martin-Belloso, O

2009-06-01

The use of high-intensity pulsed-electric field (HIPEF) and antimicrobial substances of natural origin, such as enterocin AS-48 (AS-48), nisin, and lysozyme, are among the most important nonthermal preservation methods. Thus, the purpose of this study was to evaluate the combined effect on milk inoculated with Staphylococcus aureus of the addition of AS-48 with nisin or lysozyme, or both, together with the use of HIPEF. Synergy was observed in the reduction of Staph. aureus counts with the following combination methods: i) addition of AS-48 and nisin, ii) addition of AS-48 plus use of HIPEF, and iii) addition of AS-48 and nisin plus use of HIPEF. Specifically, when 28 arbitrary units/mL of AS-48 and 20 IU/mL of nisin were added to the milk, and it was treated with HIPEF for 800 mus, over 6 log reductions were observed in the microorganism. In general, Staph. aureus inactivation was dependent on HIPEF treatment time, antimicrobial doses, and medium pH. During storage of the treated milk, survivor population was related to peptide concentration and temperature. Final cell viability was influenced by the sequence in which the treatments were applied: the addition of AS-48 or AS-48 and nisin was more effective before than after HIPEF treatment. The results obtained indicate that the combination of HIPEF and antimicrobials could be of great interest to the dairy industry, although it is necessary to study further the way in which the combined treatments act.

Antimicrobial use in swine production and its effect on the swine gut microbiota and antimicrobial resistance.

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Holman, Devin B; Chénier, Martin R

2015-11-01

Antimicrobials have been used in swine production at subtherapeutic levels since the early 1950s to increase feed efficiency and promote growth. In North America, a number of antimicrobials are available for use in swine. However, the continuous administration of subtherapeutic, low concentrations of antimicrobials to pigs also provides selective pressure for antimicrobial-resistant bacteria and resistance determinants. For this reason, subtherapeutic antimicrobial use in livestock remains a source of controversy and concern. The swine gut microbiota demonstrates a number of changes in response to antimicrobial administration depending on the dosage, duration of treatment, age of the pigs, and gut location that is sampled. Both culture-independent and -dependent studies have also shown that the swine gut microbiota contains a large number of antimicrobial resistance determinants even in the absence of antimicrobial exposure. Heavy metals, such as zinc and copper, which are often added at relatively high doses to swine feed, may also play a role in maintaining antimicrobial resistance and in the stability of the swine gut microbiota. This review focuses on the use of antimicrobials in swine production, with an emphasis on the North American regulatory context, and their effect on the swine gut microbiota and on antimicrobial resistance determinants in the gut microbiota.

Homeopathy in the Age of Antimicrobial Resistance: Is It a Viable Treatment for Upper Respiratory Tract Infections?

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Fixsen, Alison

2018-05-01

 Acute upper respiratory tract infections (URTIs) and their complications are the most frequent cause of antibiotic prescribing in primary care. With multi-resistant organisms proliferating, appropriate alternative treatments to these conditions are urgently required. Homeopathy presents one solution; however, there are many methods of homeopathic prescribing. This review of the literature considers firstly whether homeopathy offers a viable alternative therapeutic solution for acute URTIs and their complications, and secondly how such homeopathic intervention might take place.  Critical review of post 1994 clinical studies featuring homeopathic treatment of acute URTIs and their complications. Study design, treatment intervention, cohort group, measurement and outcome were considered. Discussion focused on the extent to which homeopathy is used to treat URTIs, rate of improvement and tolerability of the treatment, complications of URTIs, prophylactic and long-term effects, and the use of combination versus single homeopathic remedies.  Multiple peer-reviewed studies were found in which homeopathy had been used to treat URTIs and associated symptoms (cough, pharyngitis, tonsillitis, otitis media, acute sinusitis, etc.). Nine randomised controlled trials (RCTs) and 8 observational/cohort studies were analysed, 7 of which were paediatric studies. Seven RCTs used combination remedies with multiple constituents. Results for homeopathy treatment were positive overall, with faster resolution, reduced use of antibiotics and possible prophylactic and longer-term benefits.  Variations in size, location, cohort and outcome measures make comparisons and generalisations concerning homeopathic clinical trials for URTIs problematic. Nevertheless, study findings suggest at least equivalence between homeopathy and conventional treatment for uncomplicated URTI cases, with fewer adverse events and potentially broader therapeutic outcomes. The use of non

Development and Sequential Analysis of a New Multi-Agent, Anti-Acne Formulation Based on Plant-Derived Antimicrobial and Anti-Inflammatory Compounds

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Crina Saviuc

2017-01-01

Full Text Available The antibacterial and anti-inflammatory potential of natural, plant-derived compounds has been reported in many studies. Emerging evidence indicates that plant-derived essential oils and/or their major compounds may represent a plausible alternative treatment for acne, a prevalent skin disorder in both adolescent and adult populations. Therefore, the purpose of this study was to develop and subsequently analyze the antimicrobial activity of a new multi-agent, synergic formulation based on plant-derived antimicrobial compounds (i.e., eugenol, β-pinene, eucalyptol, and limonene and anti-inflammatory agents for potential use in the topical treatment of acne and other skin infections. The optimal antimicrobial combinations selected in this study were eugenol/β-pinene/salicylic acid and eugenol/β-pinene/2-phenoxyethanol/potassium sorbate. The possible mechanisms of action revealed by flow cytometry were cellular permeabilization and inhibition of efflux pumps activity induced by concentrations corresponding to sub-minimal inhibitory (sub-MIC values. The most active antimicrobial combination represented by salycilic acid/eugenol/β-pinene/2-phenoxyethanol/potassium sorbate was included in a cream base, which demonstrated thermodynamic stability and optimum microbiological characteristics.

Synergistic effects of antimicrobial peptide DP7 combined with antibiotics against multidrug-resistant bacteria

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Wu X

2017-03-01

Full Text Available Xiaozhe Wu,1 Zhan Li,1 Xiaolu Li,2,3 Yaomei Tian,1 Yingzi Fan,1 Chaoheng Yu,1 Bailing Zhou,1 Yi Liu,4 Rong Xiang,5 Li Yang1 1State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, 2International Center for Translational Chinese Medicine, Sichuan Academy of Chinese Medicine Sciences, Chengdu, 3Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, Luzhou, 4Department of Microbial Examination, Sichuan Center for Disease Control and Prevention, Chengdu, 5Nankai University School of Medicine, Tianjin, People’s Republic of China Abstract: Antibiotic-resistant bacteria present a great threat to public health. In this study, the synergistic effects of antimicrobial peptides (AMPs and antibiotics on several multidrug-resistant bacterial strains were studied, and their synergistic effects on azithromycin (AZT-resistance genes were analyzed to determine the relationships between antimicrobial resistance and these synergistic effects. A checkerboard method was used to evaluate the synergistic effects of AMPs (DP7 and CLS001 and several antibiotics (gentamicin, vancomycin [VAN], AZT, and amoxicillin on clinical bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli. The AZT-resistance genes (ermA, ermB, ermC, mefA, and msrA were identified in the resistant strains using quantitative polymerase chain reaction. For all the clinical isolates tested that were resistant to different antibiotics, DP7 had high antimicrobial activity (≤32 mg/L. When DP7 was combined with VAN or AZT, the effect was most frequently synergistic. When we studied the resistance genes of the AZT-resistant isolates, the synergistic effect of DP7–AZT occurred most frequently in highly resistant strains or strains carrying more than two AZT-resistance genes. A transmission electron microscopic analysis of the S. aureus

The Antimicrobial Activity of Aliquidambar orientalis mill. Against ...

African Journals Online (AJOL)

Background: Medicinal plants are an important source of substances which are claimed to induce antimicrobial, antimutagenic and antioxidant effects. Many plants have been used due to their antimicrobial treatments. Antimicrobial and antioxidant activities of L. orientalis have not been reported to the present day. The aim ...

TESTING ANTIMICROBIAL EFFICACY ON POROUS MATERIALS

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The efficacy of antimicrobial treatments to eliminate or control biological growth in the indoor environment can easily be tested on nonporous surfaces. However, the testing of antimicrobial efficacy on porous surfaces, such as those found in the indoor environment [i.e., gypsum ...

Antimicrobial peptides for the treatment of pulmonary tuberculosis, allies or foes?

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Rivas-Santiago, Bruno; Torres-Juarez, Flor

2018-03-27

Tuberculosis is an ancient disease that has become a serious public health issue in recent years, although increasing incidence has been controlled, deaths caused by Mycobacterium tuberculosis have been accentuated due to the emerging of multi-drug resistant strains and the comorbidity with diabetes mellitus and HIV. This situation is threatening the goals of world health organization (WHO) to eradicate tuberculosis in 2035. WHO has called for the creation of new drugs as an alternative for the treatment of pulmonary tuberculosis, among the plausible molecules that can be used are the antimicrobial peptides (AMPs). These peptides have demonstrated remarkable efficacy to kill mycobacteria in vitro and in vivo in experimental models, nevertheless, these peptides not only have antimicrobial activity but also have a wide variety of functions such as angiogenesis, wound healing, immunomodulation and other well-described roles into the human physiology. Therapeutic strategies for tuberculosis using AMPs must be well thought prior to their clinical use; evaluating comorbidities, family history and risk factors to other diseases, since the wide function of AMPs, they could lead to collateral undesirable effects. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Hyperosmotic nanoemulsions: Development and application of a new antimicrobial treatment for wound care

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Connell, Sean

Wound healing is the intricate process that restores function to damaged skin. The process consists of the inflammatory, proliferative and remodeling phases that orchestrate dynamic cellular responses to regenerate the cutaneous barrier. However, microbial contamination of the wound site stimulates a deleterious inflammatory response with the production of endotoxins, exotoxins and proteases that result in secondary injury. The end result is delayed healing, protracted debilitation and increased health care costs. Controlling contamination is critical for proper wound management and reduced burden on the healthcare system. Based on this concern, we developed and applied a new antimicrobial therapeutic that relies on hyperosmotic nanoemulsions (HNE). The biomechanical process consists of a high-energy nanoemulsion component that permeates the protective microbial membrane and a (ii) nonionic hyperosmoticum that facilitates intracellular water extraction to critically dehydrate the pathogen. HNE was shown to be effective against a multitude of pathogens including bacteria, antibiotic-resistant variants, fungi and viruses. Reported non-clinical studies demonstrate that the membrane disrupting nanoemulsion and hyperosmotic component act synergistically to enhance microbicidal activity. Further, results illustrate that pathogen inactivation was rapid as determined by ion and macromolecule leakage assays. Application of HNE in a pre-clinical animal model of wound healing demonstrated the treatment actively promoted healing to reduce treatment times. HNE mitigated wound infection to reduce the inflammatory response and mechanically debrided the wound to facilitate wound closure. Recent work further enhanced the stability of the nanoemulsion component with the addition of surfactant stabilizers using a low-energy spontaneous emulsification process. The refined nanoemulsion composition was stable against physical stressors and long-term storage without disrupting the

antimicrobial susceptibility pattern of Salmonella species

African Journals Online (AJOL)

user

ABSTRACT. Treatment of enteric fever is increasingly becoming very challenging due to the increasing wave of antibiotic resistance. This study is a review of the contemporary antimicrobial susceptibility pattern of. Salmonella species. The antimicrobial susceptibility pattern of Salmonella species to a wide range of.

[Measurement of antimicrobial consumption using DDD per 100 bed-days versus DDD per 100 discharges after the implementation of an antimicrobial stewardship program].

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Collado, Roberto; Losa, Juan Emilio; Álvaro, Elena Alba; Toro, Piedad; Moreno, Leonor; Pérez, Montserrat

2015-12-01

Monitoring antimicrobial consumption in hospitals is a necessary measure. The indicators commonly employed do not clearly reflect the antibiotic selection pressure. The objective of this study is to evaluate two different methods that analyze antimicrobial consumption based on DDD, per stay and per discharge, before and after the implementation an antimicrobial stewardship program. Comparative pre-post study of antimicrobial consumption with the implementation of an antimicrobial stewardship program using DDD per 100 bed-days and DDD per 100 discharges as indicators. Hospital bed days remained stable and discharges increased slightly along the period of study Antibiotic consumption in DDD per 100 bed-days decreased by 2.5% versus 3.8% when expressed as DDD per 100 discharges. Antifungal consumption decreased by more than 50%. When average hospital stay decreases, reductions in the consumption of antimicrobials with an antimicrobial stewardship program system occur at the expense of reducing the number of patients receiving treatment, while increases occur due to longer durations of treatment.

Antimicrobial efficacy of the combinations of Acacia nilotica, Murraya koenigii (Linn. Sprengel, Eucalyptus, and Psidium guajava on primary plaque colonizers: An in vitro study

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Byalakere Rudraiah Chandra Shekar

2016-01-01

Conclusion: All the triple and quadruple combinations of the plant extracts offered antimicrobial benefits either superior or comparable to 0.2% chlorhexidine against S. mutans, S. sanguis, and S. salivarius.

Antimicrobial resistance of mastitis pathogens.

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Oliver, Stephen P; Murinda, Shelton E

2012-07-01

Antibiotics are used extensively in the dairy industry to combat disease and to improve animal performance. Antibiotics such as penicillin, cephalosporin, streptomycin, and tetracycline are used for the treatment and prevention of diseases affecting dairy cows caused by a variety of gram-positive and gram-negative bacteria. Antibiotics are often administrated routinely to entire herds to prevent mastitis during the dry period. An increase in the incidence of disease in a herd generally results in increased use of antimicrobials, which in turn increases the potential for antibiotic residues in milk and the potential for increased bacterial resistance to antimicrobials. Continued use of antibiotics in the treatment and prevention of diseases of dairy cows will continue to be scrutinized. It is clear that strategies employing the prudent use of antimicrobials are needed. This clearly illustrates the importance of effective herd disease prevention and control programs. Based on studies published to date, scientific evidence does not support widespread, emerging resistance among mastitis pathogens to antibacterial drugs even though many of these antibiotics have been used in the dairy industry for treatment and prevention of disease for several decades. However, it is clear that use of antibiotics in dairy cows can contribute to increased antimicrobial resistance. While antimicrobial resistance does occur, we are of the opinion that the advantages of using antibiotics for the treatment of mastitis far outweigh the disadvantages. The clinical consequences of antimicrobial resistance of dairy pathogens affecting humans appear small. Antimicrobial resistance among dairy pathogens, particularly those found in milk, is likely not a human health concern as long as the milk is pasteurized. However, there are an increasing number of people who choose to consume raw milk. Transmission of an antimicrobial-resistant mastitis pathogen and/or foodborne pathogen to humans could occur

Antimicrobial-Resistant Bacterial Populations and Antimicrobial Resistance Genes Obtained from Environments Impacted by Livestock and Municipal Waste.

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Getahun E Agga

Full Text Available This study compared the populations of antimicrobial-resistant bacteria and the repertoire of antimicrobial resistance genes in four environments: effluent of three municipal wastewater treatment facilities, three cattle feedlot runoff catchment ponds, three swine waste lagoons, and two "low impact" environments (an urban lake and a relict prairie. Multiple liquid and solid samples were collected from each environment. The prevalences and concentrations of antimicrobial-resistant (AMR Gram-negative (Escherichia coli and Salmonella enterica and Gram-positive (enterococci bacteria were determined from individual samples (n = 174. The prevalences of 84 antimicrobial resistance genes in metagenomic DNA isolated from samples pooled (n = 44 by collection date, location, and sample type were determined. The prevalences and concentrations of AMR E. coli and Salmonella were similar among the livestock and municipal sample sources. The levels of erythromycin-resistant enterococci were significantly higher in liquid samples from cattle catchment ponds and swine waste lagoons than in liquid samples from municipal wastewater treatment facilities, but solid samples from these environments did not differ significantly. Similarly, trimethoprim/sulfamethoxazole-resistant E. coli concentrations were significantly higher in swine liquid than in municipal liquid samples, but there was no difference in solid samples. Multivariate analysis of the distribution of antimicrobial resistance genes using principal coordinate analysis showed distinct clustering of samples with livestock (cattle and swine, low impact environment and municipal samples forming three separate clusters. The numbers of class A beta-lactamase, class C beta-lactamase, and fluoroquinolone resistance genes detected were significantly higher (P < 0.05 in municipal samples than in cattle runoff or swine lagoon samples. In conclusion, we report that AMR is a very widespread phenomenon and that similar

Impact of prenatal antimicrobial treatment on fetal brain damage due to autogenous fecal peritonitis in Wistar rats: A Histomorphometric Study

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Neylane Gadelha

2017-10-01

Full Text Available Purpose: To investigate brain neuronal density in newborn rats whose mothers were subjected to fecal peritonitis and compare findings between rats born to mothers treated and not treated with antimicrobials. Methods: Peritonitis was induced with a 10% fecal suspension (4mL/kg in 2 pregnant rats. Of these, 1 received antimicrobial treatment 24 hours after peritonitis induction: moxifloxacin and dexamethasone plus 2 mL of the inner bark of the Schinus terebinthifolius raddi extract. One pregnant rat underwent no intervention and served as a control. Results: The newborn brains of rats born to mothers with fecal peritonitis were significantly smaller and of less firm consistency. Brain neuronal density was lower in the untreated group than in the control and treated groups (P<0.01. Conclusions: Untreated peritonitis caused brain damage in the offspring, which was averted by effective early antimicrobial treatment. This approach may provide an early avenue for translation of such therapy in humans. Keywords: peritonitis, brain injuries, rats

Evaluating the antimicrobial activity of Nisin, Lysozyme and Ethylenediaminetetraacetate incorporated in starch based active food packaging film.

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Bhatia, Sugandha; Bharti, Anoop

2015-06-01

The pleothera of micro organisms obtained from contaminated food cultured in a starch broth was effectively tested against antibacterial agents, i.e. nisin, lysozyme and chelating agent EDTA. A variety of combination treatments of these antimicrobial agents and their incorporation in Starch based active packaging film according to their permissibility standards was done. 4 variables of Nisin concentration (ranging from 0 to 750 IU/ml), 3 variables of lysozyme concentration (ranging from 0 to 500 IU/ml) and 3 variables of EDTA concentration from (0 to 20 μM) were chosen. Bacterial inhibition by combination of different levels of different factors without antimicrobial films was evaluated using a liquid incubation method. The samples were assayed for turbidity at interval of 2, 4 and 24 h to check effectiveness of combined effects of antimicrobial agents which proved a transitory bactericidal effect for short incubation times. Zone of Inhibition was observed in the antimicrobial films prepared by agar diffusion method. Statistical analysis of experimental data for their antimicrobial spectrum was carried out by multi regression analysis and ANOVA using Design-Expert software to plot the final equation in terms of coded factors as antimicrobial agents. The experimental data indicated that the model was highly significant. Results were also evaluated graphically using response surface showing interactions between two factors, keeping other factor fixed at values at the center of domain. Synergy was also determined among antibacterial agents using the fractional inhibitory concentration (FIC) index which was observed to be 0.56 supporting the hypothesis that nisin and EDTA function as partial synergistically. The presented work aimed to screen in quick fashion the combinatorial effect of three antimicrobial agents and evaluating their efficacy in anti microbial film development.

A Novel Teaching Tool Combined With Active-Learning to Teach Antimicrobial Spectrum Activity.

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MacDougall, Conan

2017-03-25

Objective. To design instructional methods that would promote long-term retention of knowledge of antimicrobial pharmacology, particularly the spectrum of activity for antimicrobial agents, in pharmacy students. Design. An active-learning approach was used to teach selected sessions in a required antimicrobial pharmacology course. Students were expected to review key concepts from the course reader prior to the in-class sessions. During class, brief concept reviews were followed by active-learning exercises, including a novel schematic method for learning antimicrobial spectrum of activity ("flower diagrams"). Assessment. At the beginning of the next quarter (approximately 10 weeks after the in-class sessions), 360 students (three yearly cohorts) completed a low-stakes multiple-choice examination on the concepts in antimicrobial spectrum of activity. When data for students was pooled across years, the mean number of correct items was 75.3% for the items that tested content delivered with the active-learning method vs 70.4% for items that tested content delivered via traditional lecture (mean difference 4.9%). Instructor ratings on student evaluations of the active-learning approach were high (mean scores 4.5-4.8 on a 5-point scale) and student comments were positive about the active-learning approach and flower diagrams. Conclusion. An active-learning approach led to modestly higher scores in a test of long-term retention of pharmacology knowledge and was well-received by students.

Determinants of antimicrobial treatment for udder health in Danish dairy cattle herds

DEFF Research Database (Denmark)

Gussmann, Maya Katrin; Græsbøll, Kaare; Toft, Nils

2017-01-01

Societal pressure to limit the use of antibiotics in livestock production systems, including dairy cattle systems, is consistently increasing. To motivate farmers to reduce antibiotic usage, it is important to understand the factors that determine whether a cow will be treated with antibiotics...... or not. If farmers' usual practices regarding antibiotic treatments are taken into account, they may be motivated to adopt control measures that can facilitate prudent use of antibiotics and are at the same time cost-effective. In this study, we analyzed database recordings of milk yield and somatic cell...... count from the routine milk recording scheme, clinical registrations of mastitis and PCR results, and cow factors such as days in milk and parity in relation to antibiotic treatments for 518 dairy herds in Denmark. Farm-wise logistic regressions were used to predict antimicrobial treatment based...

Recommendations for the empirical treatment of complicated urinary tract infections using surveillance data on antimicrobial resistance in the Netherlands

NARCIS (Netherlands)

Koningstein, Maike; van der Bij, Akke K.; de Kraker, Marlieke E. A.; Monen, Jos C.; Muilwijk, Jan; de Greeff, Sabine C.; Geerlings, Suzanne E.; van Hall, Maurine A. Leverstein-; Vlaspolder, F.; Cohen Stuart, J. W. T.; van Hees, B. C.; Wintermans, R. G. F.; Altorf-van der Kuil, W.; Alblas, J.; van der Bij, A. K.; Frentz, D.; Leenstra, T.; Monen, J. C.; Muilwijk, J.; Notermans, D. W.; de Greeff, S. C.; van Keulen, P. H. J.; Kluytmans, J. A. J. W.; Mattsson, E. E.; Sebens, F. W.; Frenay, H. M. E.; Maraha, B.; Heilmann, F. G. C.; Halaby, T.; Versteeg, D.; Hendrix, R.; Schellekens, J. F. P.; Diederen, B. M. W.; de Brauwer, E. I. G. B.; Stals, F. S.; Bakker, L. J.; Dorigo-Zetsma, J. W.; van Zeijl, J. H.; Bernards, A. T.; de Jongh, B. M.; Vlaminckx, B. J. M.; Horrevorts, A.; Kuipers, S.; Moffie, B.; Brimicombe, R. W.; Jansen, C. L.; Renders, N. H. M.; Hendrickx, B. G. A.; Buiting, A. G. M.; Kaan, J. A.

2014-01-01

Complicated urinary tract infections (c-UTIs) are among the most common nosocomial infections and a substantial part of the antimicrobial agents used in hospitals is for the treatment of c-UTIs. Data from surveillance can be used to guide the empirical treatment choices of clinicians when treating

Insect antimicrobial peptides act synergistically to inhibit a trypanosome parasite.

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Marxer, Monika; Vollenweider, Vera; Schmid-Hempel, Paul

2016-05-26

The innate immune system provides protection from infection by producing essential effector molecules, such as antimicrobial peptides (AMPs) that possess broad-spectrum activity. This is also the case for bumblebees, Bombus terrestris, when infected by the trypanosome, Crithidia bombi Furthermore, the expressed mixture of AMPs varies with host genetic background and infecting parasite strain (genotype). Here, we used the fact that clones of C. bombi can be cultivated and kept as strains in medium to test the effect of various combinations of AMPs on the growth rate of the parasite. In particular, we used pairwise combinations and a range of physiological concentrations of three AMPs, namely Abaecin, Defensin and Hymenoptaecin, synthetized from the respective genomic sequences. We found that these AMPs indeed suppress the growth of eight different strains of C. bombi, and that combinations of AMPs were typically more effective than the use of a single AMP alone. Furthermore, the most effective combinations were rarely those consisting of maximum concentrations. In addition, the AMP combination treatments revealed parasite strain specificity, such that strains varied in their sensitivity towards the same mixtures. Hence, variable expression of AMPs could be an alternative strategy to combat highly variable infections.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).

Blue light enhances the antimicrobial activity of honey against Pseudomonas aeruginosa

Science.gov (United States)

Orlandi, Viviana Teresa; Bolognese, Fabrizio; Barbieri, Paola

2018-02-01

Pseudomonas aeruginosa may be isolated from skin wounds of burn patients, bedsore and diabetic ulcers. The healing of wounds is often impaired by the intrinsic antibiotic resistance, the tolerance to many antimicrobials and the ability to form biofilm of this opportunistic pathogen. Finding new topical treatments to combine with antibiotics is thus essential. Among natural products, the antimicrobial properties of honeys have been known for millennia. In this study honey and visible light have been combined to control the growth of P. aeruginosa PAO1. The irradiation by a broad spectrum light source of bacteria inoculated onto 2 % w/v fir and forest honeydew (HD) honeys caused a killing effect that the honeys alone or the light alone did not show. This antimicrobial activity was light energy-dose and honey-concentration dependent. Among the tested honeys, the fir and forest HD honeys were the most efficient ones. In particular, the irradiation by blue LED (λmax = 466 nm) yielded good rates of killing, that were significantly higher in comparison to irradiation alone and honey alone. Interestingly, a similar effect was obtained by plating bacteria on blue LED pre-irradiated HD honeys. The combined use of honey and blue light was also successful in inhibiting the biofilm formation of P. aeruginosa. The blue LED irradiation of PAO1 administered with 10 % w/v forest HD honey significantly enhanced the inhibition of biofilm formation in comparison to dark incubated honey.

Microencapsulated antimicrobial compounds as a means to enhance electron beam irradiation treatment for inactivation of pathogens on fresh spinach leaves.

Science.gov (United States)

Gomes, Carmen; Moreira, Rosana G; Castell-Perez, Elena

2011-08-01

Recent outbreaks associated to the consumption of raw or minimally processed vegetable products that have resulted in several illnesses and a few deaths call for urgent actions aimed at improving the safety of those products. Electron beam irradiation can extend shelf-life and assure safety of fresh produce. However, undesirable effects on the organoleptic quality at doses required to achieve pathogen inactivation limit irradiation. Ways to increase pathogen radiation sensitivity could reduce the dose required for a certain level of microbial kill. The objective of this study was to evaluate the effectiveness of using natural antimicrobials when irradiating fresh produce. The minimum inhibitory concentration of 5 natural compounds and extracts (trans-cinnamaldehyde, eugenol, garlic extract, propolis extract, and lysozyme with ethylenediaminetetraacetate acid (disodium salt dihydrate) was determined against Salmonella spp. and Listeria spp. In order to mask odor and off-flavor inherent of several compounds, and to increase their solubility, complexes of these compounds and extracts with β-cyclodextrin were prepared by the freeze-drying method. All compounds showed bacteriostatic effect at different levels for both bacteria. The effectiveness of the microencapsulated compounds was tested by spraying them on the surface of baby spinach inoculated with Salmonella spp. The dose (D₁₀ value) required to reduce the bacterial population by 1 log was 0.190 kGy without antimicrobial addition. The increase in radiation sensitivity (up to 40%) varied with the antimicrobial compound. These results confirm that the combination of spraying microencapsulated antimicrobials with electron beam irradiation was effective in increasing the killing effect of irradiation. Foodborne illness outbreaks attributed to fresh produce consumption have increased and present new challenges to food safety. Current technologies (water washing or treating with 200 ppm chlorine) cannot

Extended antimicrobial treatment of bacterial vaginosis combined with human lactobacilli to find the best treatment and minimize the risk of relapses

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Hammarström Lennart

2011-08-01

Full Text Available Abstract Background The primary objective of this study was to investigate if extended antibiotic treatment against bacterial vaginosis (BV together with adjuvant lactobacilli treatment could cure BV and, furthermore, to investigate factors that could cause relapse. Methods In all, 63 consecutive women with bacterial vaginosis diagnosed by Amsel criteria were offered a much more aggressive treatment of BV than used in normal clinical practice with repeated antibiotic treatment with clindamycin and metronidazole together with vaginal gelatine capsules containing different strains of lactobacilli both newly characterised and a commercial one (109 freeze-dried bacteria per capsule. Oral clindamycin treatment was also given to the patient's sexual partner. Results The cure rate was 74.6% after 6 months. The patients were then followed as long as possible or until a relapse. The cure rate was 65.1% at 12 months and 55.6% after 24 months. There was no significant difference in cure rate depending on which Lactobacillus strains were given to the women or if the women were colonised by lactobacilli. The most striking factor was a new sex partner during the follow up period where the Odds Ratio of having a relapse was 9.3 (2.8-31.2 if the patients had a new sex partner during the observation period. Conclusions The study shows that aggressive treatment of the patient with antibiotics combined with specific Lactobacillus strain administration and partner treatment can provide long lasting cure. A striking result of our study is that change of partner is strongly associated with relapse of BV. Trial registration ClinicalTrials.gov: NCT01245322

Macromolecular agents with antimicrobial potentialities: A drive to combat antimicrobial resistance.

Science.gov (United States)

Bilal, Muhammad; Rasheed, Tahir; Iqbal, Hafiz M N; Hu, Hongbo; Wang, Wei; Zhang, Xuehong

2017-10-01

In recent years, the antimicrobial resistance (AMR) or multidrug resistance (MDR) has become a serious health concern and major challenging issue, worldwide. After decades of negligence, the AMR has now captured global attention. The increasing number of antibiotic-resistant strains has threatened the achievements of science and medicine since it inactivates conventional antimicrobial therapeutics. Scientists are trying to respond to AMR/MDR threat by exploring innovative platforms and new therapeutic strategies to tackle infections from these resistant strains and bypass treatment limitations related to these pathologies. The present review focuses on the utilization of bio-inspired novel constructs and their potential applications as novel antimicrobial agents. The first part of the review describes plant-based biological macromolecules containing an immense variety of secondary metabolites, which could be potentially used as alternative strategies to combat antimicrobial resistance. The second part discusses the potential of metal-based macromolecules as effective antimicrobial platforms for preventing infections from resistant strains. The third part comprehensively elucidates how nanoparticles, in particular, metal-integrated nanoparticles can overcome this AMR or MDR issue. Towards the end, information is given with critical concluding remarks, gaps, and finally envisioned with future considerations. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinical Application of Antimicrobial Bone Graft Substitute in Osteomyelitis Treatment: A Systematic Review of Different Bone Graft Substitutes Available in Clinical Treatment of Osteomyelitis

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T. A. G. van Vugt

2016-01-01

Full Text Available Osteomyelitis is a common occurrence in orthopaedic surgery, which is caused by different bacteria. Treatment of osteomyelitis patients aims to eradicate infection by debridement surgery and local and systemic antibiotic therapy. Local treatment increases success rates and can be performed with different antimicrobial bone graft substitutes. This review is performed to assess the level of evidence of synthetic bone graft substitutes in osteomyelitis treatment. According to the PRISMA statement for reporting systematic reviews, different types of clinical studies concerning treatment of osteomyelitis with bone graft substitutes are included. These studies are assessed on their methodological quality as level of evidence and bias and their clinical outcomes as eradication of infection. In the fifteen included studies, the levels of evidence were weak and in ten out of the fifteen studies there was a moderate to high risk of bias. However, first results of the eradication of infection in these studies showed promising results with their relatively high success rates and low complication rates. Due to the low levels of evidence and high risks of bias of the included studies, these results are inconclusive and no conclusions regarding the performed clinical studies of osteomyelitis treatment with antimicrobial bone graft substitutes can be drawn.

Antimicrobial Resistance Trend of Bacteria from Clinical Isolates: An ...

African Journals Online (AJOL)

For decades, antimicrobials have proven useful for the treatment of bacterial infections. However, the immergence of antimicrobial resistance has become a major challenge to public health in many countries. The aim of this study was to investigate the antimicrobial susceptibility of bacterial isolates from clinical sources.

Combined Medical Treatment Of Chronic Pancreatitis

Directory of Open Access Journals (Sweden)

Umnova Larisa

2015-04-01

Full Text Available The aim of the study was to determine the most effective medical treatment of patients with chronic pancreatitis, by using either pancreatin alone or in combination with proton pump inhibitor (PPI or PPI and non-steroidal anti-inflammatory drug (NSAID. Patients with chronic pancreatitis, who did not require a surgical treatment, received medical treatment for a one–month period: 20 patients received pancreatin monotherapy; 48 patients were given a combination of pancreatin and PPI; 38 patients were treated with a combination of pancreatin, PPI and NSAID (PNP therapy group. In comparison with other groups, patients in the PNP therapy group showed improvement in body mass index, abdominal pain, bowel movements, chronic pancreatitis severity, as well as their quality of life assessment (p < 0.05. The combination of pancreatin, PPI and NSAID was the most effective among those applied in chronic pancreatitis patient treatment. A one–month long course of this therapy was safe and did not cause any significant adverse effects. The combination of pancreatin, PPI and NSAID for treatment of chronic pancreatitis can be recommended, as it is based on pathogenesis of the disease, effective, safe and economically advantageous.

Elimination of Listeria monocytogenes in sausage meat by combination treatment: Radiation and radiation-resistant bacteriocins

International Nuclear Information System (INIS)

Turgis, Mélanie; Stotz, Viviane; Dupont, Claude; Salmieri, Stéphane; Khan, Ruhul A.; Lacroix, Monique

2012-01-01

Two new bacteria were isolated from human feces and were designated MT 104 and MT 162. They were able to produce bacteriocins that are active against five strains of Listeria monocytogenes. Bacteriocins produced by these isolated strains had 100% and 82.35% residual activity when they were treated by gamma radiation at doses of 4 and 40 kGy, respectively. A reduction of 1.0, 1.5 and 3 log CFU/g of L. monocytogenes was observed in sausage meat when treated with bacteriocins from MT 104, MT 162, and nisin, respectively. For synergic effect, the D 10 value in presence of the bacteriocins produced by MT 104 showed a 1.08 fold increased relative sensitivity of L. monocytogenes as compared to control after 5 days. The highest synergic effect was observed in presence of nisin which led to 1.61 fold increased relative sensitivity. Combined treatments with nisin and γ-irradiation showed a synergic antimicrobial effect in meat after 24 h and 5 days of storage. A synergic effect was observed only after 5 days at 4 °C for the bacteriocin from MT 104, as compared to the bacteriocin produced by MT 162 that had only an additive antimicrobial effect in all conditions.

Elimination of Listeria monocytogenes in sausage meat by combination treatment: Radiation and radiation-resistant bacteriocins

Science.gov (United States)

Turgis, Mélanie; Stotz, Viviane; Dupont, Claude; Salmieri, Stéphane; Khan, Ruhul A.; Lacroix, Monique

2012-08-01

Two new bacteria were isolated from human feces and were designated MT 104 and MT 162. They were able to produce bacteriocins that are active against five strains of Listeria monocytogenes. Bacteriocins produced by these isolated strains had 100% and 82.35% residual activity when they were treated by gamma radiation at doses of 4 and 40 kGy, respectively. A reduction of 1.0, 1.5 and 3 log CFU/g of L. monocytogenes was observed in sausage meat when treated with bacteriocins from MT 104, MT 162, and nisin, respectively. For synergic effect, the D10 value in presence of the bacteriocins produced by MT 104 showed a 1.08 fold increased relative sensitivity of L. monocytogenes as compared to control after 5 days. The highest synergic effect was observed in presence of nisin which led to 1.61 fold increased relative sensitivity. Combined treatments with nisin and γ-irradiation showed a synergic antimicrobial effect in meat after 24 h and 5 days of storage. A synergic effect was observed only after 5 days at 4 °C for the bacteriocin from MT 104, as compared to the bacteriocin produced by MT 162 that had only an additive antimicrobial effect in all conditions.

Shedding of cephalosporin resistant Escherichia coli in pigs from conventional farms after early treatment with antimicrobials.

Science.gov (United States)

Cameron-Veas, Karla; Moreno, Miguel A; Fraile, Lorenzo; Migura-Garcia, Lourdes

2016-05-01

This study assessed the dynamics of cephalosporin resistant (CR) E. coli populations during the life cycle of pigs treated early in life with ceftiofur or tulathromycin. The study was conducted at eight conventional pig farms; four for each treatment with ceftiofur or tulathromycin. At each farm, 70 7-day-old piglets were divided into two groups: a control group (n = 30) and a treatment group (n = 40). Faecal samples were collected on day 0 and on days 2, 7 and 180 post-treatment. Sows were also sampled on day 0. CR E. coli were selected on MacConkey agar with ceftriaxone. On five farms, 7-day-old piglets excreted CR E. coli before treatment associated with the presence of CR E. coli in sows. The occurrence of CR E. coli positive animals decreased with increasing piglet age. The remaining three farms tested negative for CR E. coli during the study period. Results demonstrated great variability in the frequency of CR E. coli positive animals between farms, independent of treatment. Treatment with ceftiofur resulted in a transitory increase in the counts of CR E. coli after 48 h. However, other risk factors including the presence of CR E. coli in sows and animal age were more important than antimicrobial treatment. Accordingly, intervention strategies targeting sows would likely have a beneficial effect in reducing the occurrence of antimicrobial resistance in primary pig production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cross-sectional prospective survey to study indication-based usage of antimicrobials in animals: Results of use in cattle

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Pyörälä Satu

2008-04-01

Full Text Available Abstract Background Indication-based data on the use of antimicrobials in animals were collected using a prospective cross-sectional survey, similarly as for surveys carried out in human medicine, but adapting the questionnaire to include veterinary-specific issues. The participating veterinarians were randomly selected from a sample population of practising veterinarians. The sampling was stratified to take into account the proportions of different types of veterinary practice in the country. All patients consulting the veterinary practice during a 1-week period were included in the study and veterinarians returned a completed questionnaire for each patient receiving antimicrobial treatment. As cattle received most of the treatments, results from the survey are given using cattle as an example species. Results The survey was sent to 681 veterinarians, of whom 262 (39% responded. In total 2850 questionnaires were completed. The largest quantities of antimicrobials, measured in kilograms, were used for cattle, followed by pigs, dogs and horses. The species that were treated most were cattle (n = 1308, dogs (n = 989 and cats (n = 311. For cattle, the most common reason for treatment was acute mastitis (52%, followed by dry-cow therapy (21%, subclinical mastitis (6% and treatment for acute enteritis (4%. The remaining treatments covered 17% of cattle patients and 15 different indications. For acute mastitis, parenteral or intramammary treatment was used in 36% and 34% of the cases, respectively. The remaining 30% received both treatments simultaneously. Of the parenteral treatments (n = 459, benzyl penicillin was used in 83% of the treated animals (n = 379, while fluoroquinolones were used in 49 cases (11%. Of the 433 cows receiving intramammary treatment, ampicillin combined with cloxacillin was most commonly used (n = 157; 36%, followed by cephalexin+streptomycin (n = 113; 26%. Conclusion This cross-sectional prospective survey provided a useful

Cross-sectional prospective survey to study indication-based usage of antimicrobials in animals: results of use in cattle.

Science.gov (United States)

Thomson, Katariina; Rantala, Merja; Hautala, Maria; Pyörälä, Satu; Kaartinen, Liisa

2008-04-14

Indication-based data on the use of antimicrobials in animals were collected using a prospective cross-sectional survey, similarly as for surveys carried out in human medicine, but adapting the questionnaire to include veterinary-specific issues. The participating veterinarians were randomly selected from a sample population of practising veterinarians. The sampling was stratified to take into account the proportions of different types of veterinary practice in the country. All patients consulting the veterinary practice during a 1-week period were included in the study and veterinarians returned a completed questionnaire for each patient receiving antimicrobial treatment. As cattle received most of the treatments, results from the survey are given using cattle as an example species. The survey was sent to 681 veterinarians, of whom 262 (39%) responded. In total 2850 questionnaires were completed. The largest quantities of antimicrobials, measured in kilograms, were used for cattle, followed by pigs, dogs and horses. The species that were treated most were cattle (n = 1308), dogs (n = 989) and cats (n = 311). For cattle, the most common reason for treatment was acute mastitis (52%), followed by dry-cow therapy (21%), subclinical mastitis (6%) and treatment for acute enteritis (4%). The remaining treatments covered 17% of cattle patients and 15 different indications. For acute mastitis, parenteral or intramammary treatment was used in 36% and 34% of the cases, respectively. The remaining 30% received both treatments simultaneously. Of the parenteral treatments (n = 459), benzyl penicillin was used in 83% of the treated animals (n = 379), while fluoroquinolones were used in 49 cases (11%). Of the 433 cows receiving intramammary treatment, ampicillin combined with cloxacillin was most commonly used (n = 157; 36%), followed by cephalexin+streptomycin (n = 113; 26%). This cross-sectional prospective survey provided a useful method for the collection of information on

Combination treatment of neuropathic pain

DEFF Research Database (Denmark)

Holbech, Jakob Vormstrup; Jung, Anne; Jonsson, Torsten

2017-01-01

BACKGROUND: Current Danish treatment algorithms for pharmacological treatment of neuropathic pain (NeP) are tricyclic antidepressants (TCA), gabapentin and pregabalin as first-line treatment for the most common NeP conditions. Many patients have insufficient pain relief on monotherapy, but combin...

Antimicrobial stewardship in long term care facilities: what is effective?

Science.gov (United States)

Nicolle, Lindsay E

2014-02-12

Intense antimicrobial use in long term care facilities promotes the emergence and persistence of antimicrobial resistant organisms and leads to adverse effects such as C. difficile colitis. Guidelines recommend development of antimicrobial stewardship programs for these facilities to promote optimal antimicrobial use. However, the effectiveness of these programs or the contribution of any specific program component is not known. For this review, publications describing evaluation of antimicrobial stewardship programs for long term care facilities were identified through a systematic literature search. Interventions included education, guidelines development, feedback to practitioners, and infectious disease consultation. The studies reviewed varied in types of facilities, interventions used, implementation, and evaluation. Comprehensive programs addressing all infections were reported to have improved antimicrobial use for at least some outcomes. Targeted programs for treatment of pneumonia were minimally effective, and only for indicators of uncertain relevance for stewardship. Programs focusing on specific aspects of treatment of urinary infection - limiting treatment of asymptomatic bacteriuria or prophylaxis of urinary infection - were reported to be effective. There were no reports of cost-effectiveness, and the sustainability of most of the programs is unclear. There is a need for further evaluation to characterize effective antimicrobial stewardship for long term care facilities.

Prophylactic and metaphylactic antimicrobial use in Belgian fattening pig herds.

Science.gov (United States)

Callens, Bénédicte; Persoons, Davy; Maes, Dominiek; Laanen, Maria; Postma, Merel; Boyen, Filip; Haesebrouck, Freddy; Butaye, Patrick; Catry, Boudewijn; Dewulf, Jeroen

2012-09-01

The monitoring of antimicrobial use is an essential step to control the selection and spread of antimicrobial resistance. Between January and October 2010 data on prophylactic and metaphylactic antimicrobial use were collected retrospectively on 50 closed or semi-closed pig herds. Ninety-three percent of the group treatments were prophylactic whereas only 7% were methaphylactic. The most frequently used antimicrobials orally applied at group level were colistin (30.7%), amoxicillin (30.0%), trimethoprim-sulfonamides (13.1%), doxycycline (9.9%) and tylosin (8.1%). The most frequently applied injectable antimicrobials were tulathromycin (45.0%), long acting ceftiofur (40.1%) and long acting amoxicillin (8.4%). The treatment incidences (TI) based on the used daily dose pig (UDD(pig) or the actually administered dose per day per kg pig of a drug) for all oral and injectable antimicrobial drugs was on average 200.7 per 1000 pigs at risk per day (min=0, max=699.0), while the TI based on the animal daily dose pig (ADD(pig) or the national defined average maintenance dose per day per kg pig of a drug used for its main indication) was slightly higher (average=235.8, min=0, max=1322.1). This indicates that in reality fewer pigs were treated with the same amount of antimicrobials than theoretically possible. Injectable products were generally overdosed (79.5%), whereas oral treatments were often underdosed (47.3%). In conclusion, this study shows that prophylactic group treatment was applied in 98% of the visited herds and often includes the use of critically important and broad-spectrum antimicrobials. In Belgium, the guidelines for prudent use of antimicrobials are not yet implemented. Copyright © 2012 Elsevier B.V. All rights reserved.

Relation between antimicrobial use and resistance in Belgian pig herds

OpenAIRE

Callens, Benedicte; Boyen, Filip; Maes, Dominiek; Haesebrouck, Freddy; Butaye, Patrick; Dewulf, Jeroen

2011-01-01

The aim of this study was to determine the link between the characteristics of antimicrobial therapy and occurrence of antimicrobial resistance in Escherichia coli of clinically healthy pigs exposed to antimicrobial treatments. A total of 918 Escherichia coli isolates were obtained from faecal samples, collected from 50 pig herds at the end of the fattening period and susceptibility was tested towards 15 different antimicrobial agents, using the disk diffusion method. The Antimicrobial Resist...

Antimicrobial and biophysical properties of surfactant supplemented with an antimicrobial peptide for treatment of bacterial pneumonia.

Science.gov (United States)

Banaschewski, Brandon J H; Veldhuizen, Edwin J A; Keating, Eleonora; Haagsman, Henk P; Zuo, Yi Y; Yamashita, Cory M; Veldhuizen, Ruud A W

2015-01-01

Antibiotic-resistant bacterial infections represent an emerging health concern in clinical settings, and a lack of novel developments in the pharmaceutical pipeline is creating a "perfect storm" for multidrug-resistant bacterial infections. Antimicrobial peptides (AMPs) have been suggested as future therapeutics for these drug-resistant bacteria, since they have potent broad-spectrum activity, with little development of resistance. Due to the unique structure of the lung, bacterial pneumonia has the additional problem of delivering antimicrobials to the site of infection. One potential solution is coadministration of AMPs with exogenous surfactant, allowing for distribution of the peptides to distal airways and opening of collapsed lung regions. The objective of this study was to test various surfactant-AMP mixtures with regard to maintaining pulmonary surfactant biophysical properties and bactericidal functions. We compared the properties of four AMPs (CATH-1, CATH-2, CRAMP, and LL-37) suspended in bovine lipid-extract surfactant (BLES) by assessing surfactant-AMP mixture biophysical and antimicrobial functions. Antimicrobial activity was tested against methillicin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. All AMP/surfactant mixtures exhibited an increase of spreading compared to a BLES control. BLES+CATH-2 mixtures had no significantly different minimum surface tension versus the BLES control. Compared to the other cathelicidins, CATH-2 retained the most bactericidal activity in the presence of BLES. The BLES+CATH-2 mixture appears to be an optimal surfactant-AMP mixture based on in vitro assays. Future directions involve investigating the potential of this mixture in animal models of bacterial pneumonia. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Local and systemic antimicrobial therapy in periodontics.

Science.gov (United States)

Herrera, David; Matesanz, Paula; Bascones-Martínez, Antonio; Sanz, Mariano

2012-09-01

This review aimed to update the current evidence on the efficacy of the adjunctive use of local and systemic antimicrobials in the treatment of periodontitis and to assess whether it might improve the clinical limitations and shortcomings of standard nonsurgical treatment in the management of periodontitis. Relevant randomized clinical trials (RCT) with more than 3 months of follow-up, published from 2010 to 2012 for systemic antimicrobials and from 2008 to 2012 for local antimicrobials, were searched in Medline and critically analyzed. Scientific evidence evaluated in different systematic reviews and reviews presented at European and World Workshops were also included. Only adjunctive therapies were considered in the present review: articles comparing debridement alone or plus placebo, versus debridement plus systemic or local antimicrobials were included. Adjunctive systemic antimicrobials have been evaluated both in aggressive and chronic periodontitis: in aggressive periodontitis, amoxicillin and metronidazole have been extensively studied, reporting clinical and microbiological benefits; in chronic periodontitis, different products are under scrutiny, such as azithromycin. The clinical efficacy of local antimicrobials, although extensively demonstrated, is still surrounded by a constant debate on the cost-effectiveness evaluation and on its adequate indications. Despite the clinical efficacy of the adjunctive use of local and systemic antimicrobials, demonstrated in RCTs and in systematic reviews, there is a lack of evidence to support well-defined clinical protocols, including products and dosages. Copyright © 2012 Elsevier Inc. All rights reserved.

Antimicrobial Approaches for Textiles: From Research to Market

Directory of Open Access Journals (Sweden)

Diana Santos Morais

2016-06-01

Full Text Available The large surface area and ability to retain moisture of textile structures enable microorganisms’ growth, which causes a range of undesirable effects, not only on the textile itself, but also on the user. Due to the public health awareness of the pathogenic effects on personal hygiene and associated health risks, over the last few years, intensive research has been promoted in order to minimize microbes’ growth on textiles. Therefore, to impart an antimicrobial ability to textiles, different approaches have been studied, being mainly divided into the inclusion of antimicrobial agents in the textile polymeric fibers or their grafting onto the polymer surface. Regarding the antimicrobial agents, different types have been used, such as quaternary ammonium compounds, triclosan, metal salts, polybiguanides or even natural polymers. Any antimicrobial treatment performed on a textile, besides being efficient against microorganisms, must be non-toxic to the consumer and to the environment. This review mainly intends to provide an overview of antimicrobial agents and treatments that can be performed to produce antimicrobial textiles, using chemical or physical approaches, which are under development or already commercially available in the form of isolated agents or textile fibers or fabrics.

Polylactic Acid?Lemongrass Essential Oil Nanocapsules with Antimicrobial Properties

OpenAIRE

Liakos, Ioannis L.; Grumezescu, Alexandru Mihai; Holban, Alina Maria; Florin, Iordache; D?Autilia, Francesca; Carzino, Riccardo; Bianchini, Paolo; Athanassiou, Athanassia

2016-01-01

Polylactic acid was combined with lemongrass essential oil (EO) to produce functional nanocapsules (NCs). The obtained polylactic acid nanoparticles showed antimicrobial activity both with and without the presence of lemongrass oil; however, the presence of EO improved the activity of the NCs. The presence of lemongrass assisted the formation of well-separated NCs and also provided enhanced antimicrobial properties, since lemongrass is known for its antimicrobial character. Fluorescence micro...

Enhancing safety and aroma appealing of fresh-cut fruits and vegetables using the antimicrobial and aromatic power of essential oils.

Science.gov (United States)

Ayala-Zavala, J Fernando; González-Aguilar, Gustavo A; del-Toro-Sánchez, L

2009-09-01

Microbial and aroma attributes are within the most decisive factors limiting safety and sensory appealing of fresh-cut fruits and vegetables. Alternatively, several plant essential oils (EOs) are constituted of several volatile active compounds and most of them present antimicrobial potential and had different aroma profile. Considering these premises, this hypothesis article states that safety and aroma appealing of fresh-cut produce could be improved with EO treatment. EOs could prevent fresh-cut fruit decay; however, their volatile constituents could be sorbed by the produce, and according to the aroma notes of the antimicrobial oil, sensorial appealing of odor, and flavor of the treated produce might be affected positively or negatively. Specifically, garlic oil is a natural antimicrobial constituted by sulfur compounds, which are responsible for its odor and antimicrobial properties. Besides, fresh-cut tomato is a highly perishable product that needs antimicrobial agents to preserve its quality and safety for a longer period of time. From the sensorial point of view, aroma combination of garlic and tomato is a common seasoning practice in Europe and America and well accepted by consumers. Once the right combination of flavors between the EOs and the fresh-cut produce has been selected, safety and quality of the treated fruit could be improved by adding antimicrobial protection and extra aroma. Therefore, other combinations between EOs and fresh-cut produce are discussed. This approximation could reinforce the trends of natural food preservation, accomplishing the demands of the increasing sector of consumers demanding tasty and convenient fresh-cut produce, containing only natural ingredients.

In Vitro Synergism between Azithromycin or Terbinafine and Topical Antimicrobial Agents against Pythium insidiosum

Science.gov (United States)

Itaqui, Sabrina R.; Verdi, Camila M.; Tondolo, Juliana S. M.; da Luz, Thaisa S.; Alves, Sydney H.; Santurio, Janio M.

2016-01-01

We describe here in vitro activity for the combination of azithromycin or terbinafine and benzalkonium, cetrimide, cetylpyridinium, mupirocin, triclosan, or potassium permanganate. With the exception of potassium permanganate, the remaining antimicrobial drugs were active and had an MIC90 between 2 and 32 μg∕ml. The greatest synergism was observed for the combination of terbinafine and cetrimide (71.4%). In vivo experimental evaluations will clarify the potential of these drugs for the topical treatment of lesions caused by Pythium insidiosum. PMID:27216049

Antimicrobial susceptibility testing before first-line treatment for Helicobacter pylori infection in patients with dual or triple antibiotic resistance.

Science.gov (United States)

Cosme, Angel; Montes, Milagrosa; Ibarra, Begoña; Tamayo, Esther; Alonso, Horacio; Mendarte, Usua; Lizasoan, Jacobo; Herreros-Villanueva, Marta; Bujanda, Luis

2017-05-14

To evaluate the efficacy of antimicrobial susceptibility-guided therapy before first-line treatment for infection in patients with dual or triple antibiotic resistance. A total of 1034 patients infected by Helicobacter pylori ( H. pylori ) during 2013-2014 were tested for antimicrobial susceptibility. 157 of 1034 (15%) patients showed resistance to two (127/1034; 12%) and to three (30/1034; 3%) antibiotics. Sixty-eight patients with dual H. pylori -resistance (clarithromycin, metronidazole or levofloxacin) were treated for 10 d with triple therapies: OAL (omeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and levofloxacin 500 mg b.i.d.) 43 cases, OAM (omeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d., and metronidazole 500 mg b.i.d.) 12 cases and OAC (omeprazole 20 mg b.id., amoxicillin 1 g b.i.d., and clarithromycin 500 mg b.i.d.) 13 cases based on the antimicrobial susceptibility testing. Twelve patients showed triple H. pylori -resistance (clarithromycin, metronidazole and levofloxacin) and received for 10 d triple therapy with OAR (omeprazole 20 mg b.id., amoxicillin 1 g b.i.d., and rifabutin 150 mg b.i.d.). Eradication was confirmed by 13C-urea breath test. Adverse effects and compliance were assessed by a questionnaire. Intention-to-treat eradication rates were: OAL (97.6%), OAM (91.6%), OAC (92.3%) and OAR (58.3%). Cure rate was significantly higher in naïve patients treated with OAR-10 compared to patients who had two or three previous treatment failures (83% vs 33%). Adverse events rates for OAL, OAM, OAC and OAR were 22%, 25%, 23% and 17%, respectively, all of them mild-moderate. Antimicrobial susceptibility-guided triple therapies during 10 d for first-line treatment leads to an eradication rate superior to 90% in patients with dual antibiotic H. pylori resistance.

Antibiofilm Efficacy of DispersinB Wound Spray Used in Combination with a Silver Wound Dressing

Directory of Open Access Journals (Sweden)

Purushottam V. Gawande

2014-01-01

Full Text Available Chronic wounds including diabetic foot ulcers, pressure ulcers, and venous leg ulcers are a worldwide health problem. As the traditional methods of treatment have proven ineffective against chronic wounds involving biofilms, there is an unmet clinical need for developing products with an antibiofilm component that inhibits and/or disrupts biofilms and thus make the biofilm-embedded bacteria more susceptible to antimicrobial therapy. We developed a DispersinB® antibiofilm enzyme-based wound spray for treating chronic wounds in conjunction with an antimicrobial. Under in vitro conditions, the DispersinB® and Acticoat™ combination performed significantly better ( P < 0.05 than Acticoat™ alone, indicating the synergy between the two compounds because of DispersinB® enhancing the antimicrobial activity of Acticoat™. Furthermore, DispersinB® wound spray enhanced the antimicrobial activity of Acticoat™ in a chronic wound mouse model of methicillin-resistant Staphylococcus aureus (MRSA infection. Thus, this novel combination of DispersinB® and Acticoat™, an antimicrobial dressing, prompts clinical evaluation for potential applications in biofilm-based chronic wound management.

Controlling Listeria monocytogenes and Leuconostoc mesenteroides in Uncured Deli-style Turkey Breast Using a Clean Label Antimicrobial.

Science.gov (United States)

Weyker, Robert E; Glass, Kathleen A; Milkowski, Andrew L; Seman, Dennis L; Sindelar, Jeffrey J

2016-03-01

Interest in natural/organic meat products has resulted in the need to validate the effectiveness of clean label antimicrobials to increase safety and shelf life of these products. A Response Surface Methodology (RSM) was used to investigate the effects of varying levels of moisture, pH, and a commercial "clean-label" antimicrobial (cultured sugar-vinegar blend; CSVB) on the growth rate of Listeria monocytogenes and Leuconostoc mesenteroides in uncured turkey stored at 4 °C for 16 wk. Twenty treatment combinations of moisture (60% to 80%), pH (5.8 to 6.4), and CSVB (2.5% to 5.0%) were evaluated during phase I to develop growth curves for both microbe types, whereas the interactive effects of pH (5.8 to 6.4) and CSVB (0.0 to 4.75) were tested in 16 treatment combinations during Phase II at a single moisture level using L. monocytogenes only. CSVB inhibited L. monocytogenes growth in 14 of the 20 treatments tested in Phase I and in 12 of the 16 treatments in Phase II through 16 and 8 wk, respectively. In contrast, CSVB had little effect on L. mesenteroides, with growth inhibited in only 4 of 20 treatments in Phase I and was therefore not tested further in Phase II. Significant interactions of the RSM design coefficients yielded a predictive model for L. mesenteroides growth rate, but due to lack of growth, no growth rate model was developed for L. monocytogenes. CSVB was found to be an effective antilisteral antimicrobial, while having little effect on a spoilage microorganism. © 2016 Institute of Food Technologists®

Estimation of the clinical and economic consequences of non-compliance with antimicrobial treatment of canine skin infections.

Science.gov (United States)

Van Vlaenderen, Ilse; Nautrup, Barbara Poulsen; Gasper, Sabina M

2011-05-01

The goal of this study was to estimate the health and economic consequences of non-compliance with oral antimicrobial treatment in dogs with superficial pyoderma, wounds or abscesses in the US. A mathematical model (Markov model) which simulated treatment with long-term injectable cefovecin versus oral amoxicillin/clavulanic acid was developed and accounted for the effect of non-compliance on clinical outcomes and mean total treatment costs per patient. Efficacy parameters considered in the model were derived from clinical studies. Treatment failure due to oral antimicrobial treatment non-compliance was approximated from published data at 13.6%. US cost data for 2009 were derived from public sources. When non-compliance was considered as a cause of treatment failure with oral medication, the long-term injectable antibiotic was more effective than oral comparator (162 versus 158 days without clinical signs). Mean total treatment costs were lower with cefovecin (USD 376.74) versus amoxicillin/clavulanic acid (USD 382.34) in dogs of 25 kg; and cefovecin remained cost-saving up to a body weight of 31 kg. In large dogs, cefovecin was more costly; however, total therapy costs were less than 6% greater than with amoxicillin/clavulanic acid. Accordingly the higher drug and administration costs of the long-term injectable antibiotic were totally or substantially offset when non-compliance was considered as reason for treatment failure with oral medication. The model also allowed for the estimation of the impact of various non-compliance scenarios. Copyright © 2011 Elsevier B.V. All rights reserved.

Antimicrobial resistance of Pseudomonas spp. isolated from wastewater and wastewater-impacted marine coastal zone.

Science.gov (United States)

Luczkiewicz, Aneta; Kotlarska, Ewa; Artichowicz, Wojciech; Tarasewicz, Katarzyna; Fudala-Ksiazek, Sylwia

2015-12-01

In this study, species distribution and antimicrobial susceptibility of cultivated Pseudomonas spp. were studied in influent (INF), effluent (EFF), and marine outfall (MOut) of wastewater treatment plant (WWTP). The susceptibility was tested against 8 antimicrobial classes, active against Pseudomonas spp.: aminoglycosides, carbapenems, broad-spectrum cephalosporins from the 3rd and 4th generation, extended-spectrum penicillins, as well as their combination with the β-lactamase inhibitors, monobactams, fluoroquinolones, and polymyxins. Among identified species, resistance to all antimicrobials but colistin was shown by Pseudomonas putida, the predominant species in all sampling points. In other species, resistance was observed mainly against ceftazidime, ticarcillin, ticarcillin-clavulanate, and aztreonam, although some isolates of Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas pseudoalcaligenes, and Pseudomonas protegens showed multidrug-resistance (MDR) phenotype. Among P. putida, resistance to β-lactams and to fluoroquinolones as well as multidrug resistance become more prevalent after wastewater treatment, but the resistance rate decreased in marine water samples. Obtained data, however, suggests that Pseudomonas spp. are equipped or are able to acquire a wide range of antibiotic resistance mechanisms, and thus should be monitored as possible source of resistance genes.

The effect of heat treatment on the antimicrobial properties of honey

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Cuilan eChen

2012-07-01

Full Text Available There is increasing interest in the antimicrobial properties of honey. In most honey samples, antimicrobial activity is due to the generation of hydrogen peroxide (H2O2 by the bee-derived enzyme glucose oxidase, however the amount of H2O2 produced can vary greatly among samples. In addition, honey is a complex product, and other components may contribute to or modulate this activity, which may be further affected by processing procedures used in large-scale commercial production. In this study we examined honey derived from three native Australian floral sources that had previously been associated with H2O2-dependent activity: spotted gum (Eucalyptus maculata, red stringybark (Eucalyptus macrorrhyncha and yellowbox (Eucalyptus melliodora. Antimicrobial activity was measured using standardized assays against the bacterial pathogen Staphylococcus aureus and the fungal pathogen Candida albicans. Antibacterial activity was only seen in four of the six red stringybark samples and ranged from 12-21.1% phenol equivalence. No antibacterial activity was detected in the spotted gum or yellowbox samples. Antifungal activity ranged from MIC values of 19-38.3 % (w/v, and although all samples were significantly more active than an osmotically equivalent sugar solution, most had relatively low activity. All honey samples were provided unprocessed and underwent standard heating and filtration procedures (45˚C for 8 hours followed by filtration with a 100 µm filter, allowing the effects of commercial heating and filtration methods on antimicrobial activity and H2O2 levels to be assessed. Average antibacterial and antifungal activities decreased, but while processing was usually detrimental, occasionally the reverse was seen and antimicrobial activity increased. Significant activity was eliminated from all samples by the addition of catalase, indicating that H2O2 was chiefly responsible for their antimicrobial action, and H2O2 production was measured in the

Scottish Antimicrobial Prescribing Group (SAPG): development and impact of the Scottish National Antimicrobial Stewardship Programme.

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Nathwani, Dilip; Sneddon, Jacqueline; Malcolm, William; Wiuff, Camilla; Patton, Andrea; Hurding, Simon; Eastaway, Anne; Seaton, R Andrew; Watson, Emma; Gillies, Elizabeth; Davey, Peter; Bennie, Marion

2011-07-01

In 2008, the Scottish Management of Antimicrobial Resistance Action Plan (ScotMARAP) was published by the Scottish Government. One of the key actions was initiation of the Scottish Antimicrobial Prescribing Group (SAPG), hosted within the Scottish Medicines Consortium, to take forward national implementation of the key recommendations of this action plan. The primary objective of SAPG is to co-ordinate and deliver a national framework or programme of work for antimicrobial stewardship. This programme, led by SAPG, is delivered by NHS National Services Scotland (Health Protection Scotland and Information Services Division), NHS Quality Improvement Scotland, and NHS National Education Scotland as well as NHS board Antimicrobial Management Teams. Between 2008 and 2010, SAPG has achieved a number of early successes, which are the subject of this review: (i) through measures to optimise prescribing in hospital and primary care, combined with infection prevention measures, SAPG has contributed significantly to reducing Clostridium difficile infection rates in Scotland; (ii) there has been engagement of all key stakeholders at local and national levels to ensure an integrated approach to antimicrobial stewardship within the wider healthcare-associated infection agenda; (iii) development and implementation of data management systems to support quality improvement; (iv) development of training materials on antimicrobial stewardship for healthcare professionals; and (v) improving clinical management of infections (e.g. community-acquired pneumonia) through quality improvement methodology. The early successes achieved by SAPG demonstrate that this delivery model is effective and provides the leadership and focus required to implement antimicrobial stewardship to improve antimicrobial prescribing and infection management across NHS Scotland. Copyright © 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Combination treatment of chlorine dioxide gas and aerosolized sanitizer for inactivating foodborne pathogens on spinach leaves and tomatoes.

Science.gov (United States)

Park, Sang-Hyun; Kang, Dong-Hyun

2015-08-17

The objective of this study was to evaluate the antimicrobial effect of chlorine dioxide (ClO2) gas and aerosolized sanitizer, when applied alone or in combination, on the survival of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes inoculated onto spinach leaves and tomato surfaces. Spinach leaves and tomatoes were inoculated with a cocktail of three strains each of the three foodborne pathogens. ClO2 gas (5 or 10 ppmv) and aerosolized peracetic acid (PAA) (80 ppm) were applied alone or in combination for 20 min. Exposure to 10 ppmv of ClO2 gas for 20 min resulted in 3.4, 3.3, and 3.4 log reductions of E. coli O157:H7, S. Typhimurium, and L. monocytogenes on spinach leaves, respectively. Treatment with 80 ppm of aerosolized PAA for 20 min caused 2.3, 1.9, and 0.8 log reductions of E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively. Combined treatment of ClO2 gas (10 ppmv) and aerosolized PAA (80 ppm) for 20 min caused 5.4, 5.1, and 4.1 log reductions of E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively. E. coli O157:H7, S. Typhimurium, and L. monocytogenes on tomatoes experienced similar reduction patterns to those on spinach leaves. As treatment time increased, most combinations of ClO2 gas and aerosolized PAA showed additive effects in the inactivation of the three pathogens. Combined treatment of ClO2 gas and aerosolized PAA produced injured cells of three pathogens on spinach leaves while generally did not produce injured cells of these pathogens on tomatoes. Combined treatment of ClO2 gas (10 ppmv) and aerosolized PAA (80 ppm) did not significantly (p>0.05) affect the color and texture of samples during 7 days of storage. Copyright © 2015. Published by Elsevier B.V.

Antimicrobial resistance of thermophilic Campylobacter

DEFF Research Database (Denmark)

Aarestrup, Frank Møller; Engberg, J.

2001-01-01

Campylobacter has become the leading cause of zoonotic enteric infections in developed and developing countries world-wide. Antimicrobial resistance has emerged among Campylobacter mainly as a consequence of the use of antimicrobial agents in food animal production. Resistance to drugs of choice...... for the treatment of infections, macrolides and fluoroquinolones has emerged as a clinical problem and interventions to reduce this are recommended. Resistance to fluoroquinolones and macrolides is mediated by chromosomal mutations. Resistance to other relevant antimicrobial agents, mediated by acquired resistance...... genes, has not become widespread so far. However, resistance genes originating from both Gram-positive and Gram-negative bacterial species have been found, showing the potential for acquired resistance to emerge in Campylobacter....

USING OF COMBINED TREATMENT BETWEEN PROPOLIS (BEE GLUE) AND GAMMA RADIATION FOR EXTENDING SHELF-LIFE OF CHICKEN BURGER

International Nuclear Information System (INIS)

MATTAR, Z.A.; ABDELDAIEM, M.H.

2008-01-01

This investigation was carried out to extend the shelf-life of chicken burger using ethanol extract of propolis (EEP) at different concentrations (1 and 2%) as individual treatment using gamma irradiation at doses of 1.5, 3 and 4.5 kGy as individual treatment and combined treatments. The untreated and treated samples of chicken burger were divided into three groups, the first was control, the second group was chicken burger samples treated with 1% EEP then irradiated at doses of 1.5, 3 and 4.5 kGy and the third group was chicken burger samples treated with 2 % EEP then irradiated at doses of 1.5, 3 and 4.5 kGy. The effects of these treatments on the microbiological, chemical and sensory characteristics of chicken burger samples were studied post-treatment and during cold storage (4±1 0 C). The results showed that concentrations of EEP at 1 and 2% reduced the total bacterial count, lactic acid bacteria, Enterobacteriaceae total mold and yeast count, Staphylococcus aureus, Enterococccus faecalis and Bacillus cereus, and the growth of Salmonella spp, was not detected in all treated samples. Also, shelf-life periods were increased up to 27 days for chicken burger treated by 2% EEP and gamma radiation at dose of 4.5 kGy and these combined treatment were more effective as antimicrobial, consequently may be useful as natural food preservative

The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria

DEFF Research Database (Denmark)

Guardabassi, L.; Wong, Danilo Lo Fo; Dalsgaard, A.

2002-01-01

and anaerobically digested sludge by bacteriological counts on media selective for coliforms (MacConkey agar) and Acinetobacter spp. (Baumann agar). In addition, the level of antimicrobial susceptibility was determined by the disc-diffusion method in 442 Acinetobacter isolates identified by colony hybridisation......-resistant presumptive coliforms and Acinetobacter spp. in treated sewage and digested sludge were not significantly higher compared with raw sewage. On the contrary at one plant, statistically significant decreases were observed in the prevalence of ampicillin-resistant presumptive Acinetobacter spp. (p = 0.......0188) following sewage treatment, and in the prevalence of either ampicillin-resistant presumptive Acinetobacter spp. (p = 0.0013) or ampicillin- and gentamicin-resistant presumptive coliforms (p = 0.0273 and p = 0.0186) following sludge treatment. The results obtained by bacteriological counts were confirmed...

THE STRATEGY OF ANTIMICROBIAL THERAPY OF ACUTE UNCOMPLICATED PYELONEPHRITIS FROM THE POSITION OF ETIOLOGICAL DATA

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A. D. Kaprin

2015-01-01

Full Text Available Abstract:Acute pyelonephritis is one of the common diseases both in outpatient and in the hospital practice. The leading causative agent of this disease is E. coli. Obstructive uropathy, foreign body, vesicoureteral reflux, sexual activity, use of local contraceptives contribute to the upward development of urinary infection. The goals of antimicrobial therapy for acute uncomplicated pyelonephritis are: relief of symptoms, restoration of social activity, prevention of complications and relapse prevention. The choice of an antimicrobial agent in most cases is carried out empirically based on the data on the dominant pathogens and their regional resistance. In acute uncomplicated pyelonephritis duration of antimicrobial therapy should be 7–14 days. The drugs of choice for treatment of acute uncomplicated pyelonephritis non-severe in adults are ciprofloxacin and levofloxacin, ceftibuten and cefixime. Patients with acute uncomplicated pyelonephritis severe emergency hospitalization is shown in urological outpatient and parenteral antimicrobial therapy (carbapenems or protected aminopenicillins combined with or without amikacin with subsequent conversion to oral drugs and infusion therapy.

Combined treatment for complex intracranial aneurysm

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Chiriac A.

2015-06-01

Full Text Available Complex aneurysms often cannot be completely excluded by a single approaches. Today successful treatment of these lesions requires a combination between microsurgical and endovascular techniques. Planning of combined treatment require a very good understanding of aneurysm anatomy and a close collaboration between neurosurgeon and neuroendovascular interventionist. Endovascular coiling can usually be used as early treatment for a partially aneurysm occlusion including the ruptured area and followed by definitive clipping. On the other hand microsurgical clipping also can be used as first treatment for complex aneurysm neck reconstruction, allowing successful secondary placement of coils inside the remnant aneurysm sac

Towards a compatible probiotic-antibiotic combination therapy: assessment of antimicrobial resistance in the Japanese probiotics.

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Hammad, A M; Shimamoto, T

2010-10-01

To determine the antimicrobial resistance of the Japanese probiotics available in the market without a pharmacist's supervision. A total of 43 isolates were obtained from 40 samples of probiotics (30 dairy products and 10 products in tablet form). Isolates were identified using 16S rRNA gene sequencing and tested for their susceptibility to 14 antimicrobials. They were screened using PCR for some antibiotic resistance genes. Inactivation of cefepime, clarithromycin and vancomycin by different inocula of 11 strains was evaluated using the antibiotic inactivation bioassay. None of the dairy probiotics showed a level of constitutive resistance or carried inducible resistance genes, making them suitable to be administrated with macrolides. Among the probiotics in tablet form only Enterococcus faecium strains carrying the msrC gene showed an MIC(90) of 4 μg ml(-1). Extended-spectrum β-lactams, tetracyclines and ampicillin exhibited powerful germicidal activity against the vast majority of the probiotic strains. There is a limited choice of the Japanese probiotics that can be administered with clinically used antibiotics. Japanese probiotics are widely distributed all over the world. Through the findings of our study, we have attempted to provide guidance for clinicians interested in using the Japanese probiotics in combination with antibiotics. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

Biofilm disruption with rotating microrods enhances antimicrobial efficacy

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Mair, Lamar O.; Nacev, Aleksandar; Hilaman, Ryan; Stepanov, Pavel Y.; Chowdhury, Sagar; Jafari, Sahar; Hausfeld, Jeffrey; Karlsson, Amy J.; Shirtliff, Mark E.; Shapiro, Benjamin; Weinberg, Irving N.

2017-04-01

Biofilms are a common and persistent cause of numerous illnesses. Compared to planktonic microbes, biofilm residing cells often demonstrate significant resistance to antimicrobial agents. Thus, methods for dislodging cells from the biofilm may increase the antimicrobial susceptibility of such cells, and serve as a mechanical means of increasing antimicrobial efficacy. Using Aspergillus fumigatus as a model microbe, we magnetically rotate microrods in and around biofilm. We show that such rods can improve the efficacy of antimicrobial Amphotericin B treatments in vitro. This work represents a first step in using kinetic magnetic particle therapy for disrupting fungal biofilms.

Assessment of in vitro antitumoral and antimicrobial activities of ...

African Journals Online (AJOL)

ONOS

2010-07-05

Jul 5, 2010 ... cell line, and it showed less than 10% cell viability after treatment. Antimicrobial ... marine macro algae have also been studied extensively. Antimicrobial ... Algae samples were washed twice with distilled water and air-dried.

Overcoming Antimicrobial Resistance in Bacteria Using Bioactive Magnetic Nanoparticles and Pulsed Electromagnetic Fields

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Vitalij Novickij

2018-01-01

Full Text Available Nisin is a known bacteriocin, which exhibits a wide spectrum of antimicrobial activity, while commonly being inefficient against Gram-negative bacteria. In this work, we present a proof of concept of novel antimicrobial methodology using targeted magnetic nisin-loaded nano-carriers [iron oxide nanoparticles (NPs (11–13 nm capped with citric, ascorbic, and gallic acids], which are activated by high pulsed electric and electromagnetic fields allowing to overcome the nisin-resistance of bacteria. As a cell model the Gram-positive bacteria Bacillus subtilis and Gram-negative Escherichia coli were used. We have applied 10 and 30 kV cm-1 electric field pulses (100 μs × 8 separately and in combination with two pulsed magnetic field protocols: (1 high dB/dt 3.3 T × 50 and (2 10 mT, 100 kHz, 2 min protocol to induce additional permeabilization and local magnetic hyperthermia. We have shown that the high dB/dt pulsed magnetic fields increase the antimicrobial efficiency of nisin NPs similar to electroporation or magnetic hyperthermia methods and a synergistic treatment is also possible. The results of our work are promising for the development of new methods for treatment of the drug-resistant foodborne pathogens to minimize the risks of invasive infections.

Biofilm disruption with rotating microrods enhances antimicrobial efficacy

Energy Technology Data Exchange (ETDEWEB)

Mair, Lamar O., E-mail: Lamar.Mair@gmail.com [Weinberg Medical Physics, Inc., North Bethesda, MD (United States); Nacev, Aleksandar; Hilaman, Ryan; Stepanov, Pavel Y.; Chowdhury, Sagar; Jafari, Sahar [Weinberg Medical Physics, Inc., North Bethesda, MD (United States); Hausfeld, Jeffrey [School of Medicine and Health Sciences, George Washington University, WA (United States); Karlsson, Amy J. [Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD (United States); Shirtliff, Mark E. [School of Dentistry, University of Maryland, Baltimore, MD (United States); Shapiro, Benjamin [Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); Weinberg, Irving N. [Weinberg Medical Physics, Inc., North Bethesda, MD (United States)

2017-04-01

Biofilms are a common and persistent cause of numerous illnesses. Compared to planktonic microbes, biofilm residing cells often demonstrate significant resistance to antimicrobial agents. Thus, methods for dislodging cells from the biofilm may increase the antimicrobial susceptibility of such cells, and serve as a mechanical means of increasing antimicrobial efficacy. Using Aspergillus fumigatus as a model microbe, we magnetically rotate microrods in and around biofilm. We show that such rods can improve the efficacy of antimicrobial Amphotericin B treatments in vitro. This work represents a first step in using kinetic magnetic particle therapy for disrupting fungal biofilms. - Highlights: • Fungal biofilms have been implicated in a variety of medical ailments. • Magnetic microrods, grown via electroplating, were rotated in and around fungal biofilms. • Rotating microrods potentiate the effectiveness of antimicrobial drug. • Antimicrobial efficacy may be enhanced due to increased mixing.

Biofilm disruption with rotating microrods enhances antimicrobial efficacy

International Nuclear Information System (INIS)

Mair, Lamar O.; Nacev, Aleksandar; Hilaman, Ryan; Stepanov, Pavel Y.; Chowdhury, Sagar; Jafari, Sahar; Hausfeld, Jeffrey; Karlsson, Amy J.; Shirtliff, Mark E.; Shapiro, Benjamin; Weinberg, Irving N.

2017-01-01

Biofilms are a common and persistent cause of numerous illnesses. Compared to planktonic microbes, biofilm residing cells often demonstrate significant resistance to antimicrobial agents. Thus, methods for dislodging cells from the biofilm may increase the antimicrobial susceptibility of such cells, and serve as a mechanical means of increasing antimicrobial efficacy. Using Aspergillus fumigatus as a model microbe, we magnetically rotate microrods in and around biofilm. We show that such rods can improve the efficacy of antimicrobial Amphotericin B treatments in vitro. This work represents a first step in using kinetic magnetic particle therapy for disrupting fungal biofilms. - Highlights: • Fungal biofilms have been implicated in a variety of medical ailments. • Magnetic microrods, grown via electroplating, were rotated in and around fungal biofilms. • Rotating microrods potentiate the effectiveness of antimicrobial drug. • Antimicrobial efficacy may be enhanced due to increased mixing.

Photodynamic antimicrobial therapy in the treatment of denture stomatitis

International Nuclear Information System (INIS)

Senna, Andre Machado de

2012-01-01

Denture stomatitis (DS), also called chronic atrophic candidiasis, is the most common oral fungal infection in denture wearers. It has a multifactorial etiology, but the presence of Candida spp. biofilm on the denture is considered the most important factor for the establishment of the DS. This study aimed to evaluate the treatment of DS through the use of photodynamic antimicrobial therapy (PAT), mediated by methylene blue. For this purpose, preclinical studies and clinical trials were performed. Simulators prototypes dentures were made of methyl methacrylate polymer to serve as a basis for biofilm growth of the following species of Candida: C. albicans, C. glabrata, C. dubliniensis, C. krusei, C. tropicalis, C. parapsilosis and C. guilliermondii. Methylene blue solution at a concentration of 450 μg/mL was used as a photosensitizer. The prototypes and biofilms were irradiated with a laser of wavelength of 660 nm, potency of 100 mW, for 80 seconds. For the clinical study, subjects were divided into two groups. The first group received conventional treatment based on the use of antifungal Miconazole. The second group received the treatment by PAT. The preclinical results showed that all species of the genus Candida were susceptible to PAT, with a reduction in colonies that ranged from 2.48 to 3.93 log 10 . Clinical outcomes were evaluated for the reduction of colonies of Candida spp. located in the mucosa and in the prosthesis and relative to the improvement of the clinical aspect of the affected mucosa. Both the conventional therapy and PAT were effective in treating DS. There was no significant statistical difference between PAT and conventional treatment for any of the factors evaluated. Thus, it was concluded that PAT is effective in the treatment of denture stomatitis. (author)

Use of cryopoor plasma for albumin replacement and continuous antimicrobial infusion for treatment of septic peritonitis in a dog.

Science.gov (United States)

Ropski, Meaghan K; Guillaumin, Julien; Monnig, Andrea A; Townsend, Katy; McLoughlin, Mary A

2017-05-01

To report the successful management of a dog with septic peritonitis and septic shock secondary to enterectomy dehiscence using novel techniques for identification of intestinal dehiscence and for septic shock treatment. A 5-year-old castrated male Bernese Mountain Dog presented for lethargy 6 days following enterotomy for foreign body obstruction. Septic peritonitis was identified due to dehiscence of the enterotomy site, and resection and anastomosis were performed using a gastrointestinal anastomosis and thoracoabdominal stapling device. Postoperatively the patient experienced severe hypotension, which responded to norepinephrine constant rate infusion (CRI) after failing to improve with fluid therapy or dopamine CRI. Further treatment included antimicrobial CRI and supportive care including careful fluid therapy. Due to low effective circulating volume paired with intersititial fluid overload and large volume abdominal effusion, fluid therapy consisted of a combination of human serum albumin, canine albumin, synthetic colloids, and isotonic crystalloids. Cryopoor plasma (CPP) was used as a source of canine albumin and intravascular volume. On Day 4, food dye was given through a nasogastric tube due to suspicion of dehiscence of the anastomosis site. Dehiscence was confirmed during abdominal exploratory, and a second resection and anastomosis was performed. Abdominal partial closure with vacuum-assisted closure device was performed. Supportive care was continued with CPP CRI and imipenem CRI. Planned relaparotomy to change the vacuum-assisted closure device was performed 48 hours later, with abdominal closure 96 hours after anastomosis. The patient was discharged on Day 15. Recheck 12 months later was normal. This case includes novel techniques such food dye via nasogastric tube to identify anastomosis dehiscence, use of CPP as a source of canine albumin, and antimicrobial CRI in a dog with septic peritonitis. © Veterinary Emergency and Critical Care Society

Antimicrobial activity and mechanism of the human milk-sourced peptide Casein201

International Nuclear Information System (INIS)

Zhang, Fan; Cui, Xianwei; Fu, Yanrong; Zhang, Jun; Zhou, Yahui; Sun, Yazhou; Wang, Xing; Li, Yun; Liu, Qianqi; Chen, Ting

2017-01-01

Introduction: Casein201 is one of the human milk sourced peptides that differed significantly in preterm and full-term mothers. This study is designed to demonstrate the biological characteristics, antibacterial activity and mechanisms of Casein201 against common pathogens in neonatal infection. Methodology: The analysis of biological characteristics was done by bioinformatics. Disk diffusion method and flow cytometry were used to detect the antimicrobial activity of Casein201. Killing kinetics of Casein201 was measured using microplate reader. The antimicrobial mechanism of Casein201 was studied by electron microscopy and electrophoresis. Results: Bioinformatics analysis indicates that Casein201 derived from β-casein and showed significant sequence overlap. Antibacterial assays showed Casein201 inhibited the growth of S taphylococcus aureus and Y ersinia enterocolitica. Ultrastructural analyses revealed that the antibacterial activity of Casein201 is through cytoplasmic structures disintegration and bacterial cell envelope alterations but not combination with DNA. Conclusion: We conclude the antimicrobial activity and mechanism of Casein201. Our data demonstrate that Casein201 has potential therapeutic value for the prevention and treatment of pathogens in neonatal infection.

Antimicrobial peptide capsids of de novo design.

Science.gov (United States)

De Santis, Emiliana; Alkassem, Hasan; Lamarre, Baptiste; Faruqui, Nilofar; Bella, Angelo; Noble, James E; Micale, Nicola; Ray, Santanu; Burns, Jonathan R; Yon, Alexander R; Hoogenboom, Bart W; Ryadnov, Maxim G

2017-12-22

The spread of bacterial resistance to antibiotics poses the need for antimicrobial discovery. With traditional search paradigms being exhausted, approaches that are altogether different from antibiotics may offer promising and creative solutions. Here, we introduce a de novo peptide topology that-by emulating the virus architecture-assembles into discrete antimicrobial capsids. Using the combination of high-resolution and real-time imaging, we demonstrate that these artificial capsids assemble as 20-nm hollow shells that attack bacterial membranes and upon landing on phospholipid bilayers instantaneously (seconds) convert into rapidly expanding pores causing membrane lysis (minutes). The designed capsids show broad antimicrobial activities, thus executing one primary function-they destroy bacteria on contact.

Antimicrobial susceptibility of porcine brachyspira hyodysenteriae isolates from Switzerland

OpenAIRE

Kirchgässner, Constanze

2016-01-01

The anaerobic spirochaete Brachyspira (B.) hyodysenteriae is the causative agent of swine dysentery (SD), a severe mucohaemorrhagic diarrheal disease in pigs worldwide. Currently, no data for antimicrobial susceptibility of B. hyodysenteriae from Switzerland are available and though antimicrobial treatment is the main therapy, no standardised methods for antimicrobial susceptibility testing are established. Therefore, a broth microdilution test was performed for 30 Swiss porcine field isolate...

Effects of treatment with antimicrobial agents on the human colonic microflora

OpenAIRE

Rafii, Fatemeh

2008-01-01

Fatemeh Rafii, John B Sutherland, Carl E CernigliaDivision of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR, USAAbstract: Antimicrobial agents are the most valuable means available for treating bacterial infections. However, the administration of therapeutic doses of antimicrobial agents to patients is a leading cause of disturbance of the normal gastrointestinal microflora. This disturbance results in diminishing the natural defense mechanisms provided by the c...

Quantitative single-vesicle analysis of antimicrobial peptide-induced leakage

DEFF Research Database (Denmark)

Kristensen, Kasper; Ehrlich, Nicky; Henriksen, Jonas Rosager

2013-01-01

Although the research field of antimicrobial peptides has attracted considerable scientific attention in the past decades, the microbicidal mechanisms of antimicrobial peptides still remain elusive. One of the keys to a more profound comprehension of the function of these peptides is a deeper...... was combined with fluorescence correlation spectroscopy to quantify leakage from a bulk collection of lipid vesicles in aqueous solution. Quantitative correlation between the two techniques was achieved through a detailed experimental protocol. The potential of combining the two techniques was tested using...

Purification and characterization of ribosomal proteins L27 and L30 having antimicrobial activity produced by the Lactobacillus salivarius SGL 03.

Science.gov (United States)

Pidutti, P; Federici, F; Brandi, J; Manna, L; Rizzi, E; Marini, U; Cecconi, D

2018-02-01

The aim of this study was to investigate the antimicrobial potential of proteins secreted by a new strain of Lactobacillus salivarius. The secretome of L. salivarius SGL 03 strain was analysed by gel-assisted fractionation and MS/MS to identify low-molecular-mass proteins. This strategy allowed us to identify 10 secreted proteins. Then, a combination of heterologous expression and agar well diffusion was used to characterize them as to their antimicrobial activity, mechanisms of action and stability. Our findings indicate that L27 and L30 proteins of the 50S ribosomal subunit have antimicrobial activity against Streptococcus pyogenes, Streptococcus uberis and Enterococcus faecium. In addition, both proteins are bactericidal against S. pyogenes and maintain their antimicrobial activity after different protease treatments, at acidic pH, after heat treatment, and if stored in a refrigerated ambient at least at 4°C. The overall results demonstrated that the L27 and L30 ribosomal proteins are of interest as new antimicrobial molecules to prevent the growth of S. pyogenes, S. uberis and E. faecium. Our results provide the first insight into the extra-ribosomal activity of L27 and L30 secreted proteins of L. salivarius. This study demonstrated the capacity of L. salivarius SGL 03 to produce antimicrobial molecules and suggested this strain as a promising probiotic candidate. © 2017 The Society for Applied Microbiology.

Antimicrobial stewardship in wound care

DEFF Research Database (Denmark)

Lipsky, Benjamin A; Dryden, Matthew; Gottrup, Finn

2016-01-01

BACKGROUND: With the growing global problem of antibiotic resistance it is crucial that clinicians use antibiotics wisely, which largely means following the principles of antimicrobial stewardship (AMS). Treatment of various types of wounds is one of the more common reasons for prescribing...... of experts in infectious diseases/clinical microbiology (from the British Society for Antimicrobial Chemotherapy) and wound management (from the European Wound Management Association) who, after thoroughly reviewing the available literature and holding teleconferences, jointly produced this guidance document...

Antimicrobial drugs for treating cholera

Science.gov (United States)

Leibovici-Weissman, Ya'ara; Neuberger, Ami; Bitterman, Roni; Sinclair, David; Salam, Mohammed Abdus; Paul, Mical

2014-01-01

Background Cholera is an acute watery diarrhoea caused by infection with the bacterium Vibrio cholerae, which if severe can cause rapid dehydration and death. Effective management requires early diagnosis and rehydration using oral rehydration salts or intravenous fluids. In this review, we evaluate the additional benefits of treating cholera with antimicrobial drugs. Objectives To quantify the benefit of antimicrobial treatment for patients with cholera, and determine whether there are differences between classes of antimicrobials or dosing schedules. Search methods We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; African Index Medicus; LILACS; Science Citation Index; metaRegister of Controlled Trials; WHO International Clinical Trials Registry Platform; conference proceedings; and reference lists to March 2014. Selection criteria Randomized and quasi-randomized controlled clinical trials in adults and children with cholera that compared: 1) any antimicrobial treatment with placebo or no treatment; 2) different antimicrobials head-to-head; or 3) different dosing schedules or different durations of treatment with the same antimicrobial. Data collection and analysis Two reviewers independently applied inclusion and exclusion criteria, and extracted data from included trials. Diarrhoea duration and stool volume were defined as primary outcomes. We calculated mean difference (MD) or ratio of means (ROM) for continuous outcomes, with 95% confidence intervals (CI), and pooled data using a random-effects meta-analysis. The quality of evidence was assessed using the GRADE approach. Main results Thirty-nine trials were included in this review with 4623 participants. Antimicrobials versus placebo or no treatment Overall, antimicrobial therapy shortened the mean duration of diarrhoea by about a day and a half compared to placebo or no treatment (MD -36.77 hours, 95% CI -43

Antimicrobial susceptibilities of Listeria monocytogenes human strains isolated from 1970 to 2008 in Brazil

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Cristhiane Moura Falavina dos Reis

2011-04-01

Full Text Available INTRODUCTION: Listeria monocytogenes is the causative agent of listeriosis, a foodborne illness that affects mainly pregnant women, the elderly and immunocompromised patients. The primary treatment is a combination of ampicillin with an aminoglycoside, in addition to a second-choice drug represented by chloramphenicol, erythromycin, tetracycline and rifampicin. The aim of this study was to analyze the antimicrobial susceptibility profile of strains isolated from human sources in the last four decades. METHODS: Sixty-eight strains were selected from the culture collection of the Laboratory of Bacterial Zoonoses/LABZOO/FIOCRUZ isolated in different regions of Brazil from 1970 to 2008 and primarily isolated from cerebrospinal fluid and blood culture. Susceptibility tests to antimicrobials drugs were evaluated using the criteria established by Soussy using the Kirby-Bauer method and E-Test strips were used to determine the minimum inhibitory concentration (MIC. RESULTS: Among the strains tested, serovar L4b (60.3% was the most prevalent, followed by serovar 1/2a (20.6%, 1/2b (13.2% and the more uncommon serovars 1/2c, 3b and 4ab (5.9%. All strains were susceptible to ampicillin, cephalothin, erythromycin, gentamicin, teicoplanin and vancomycin. Only one strain (1.5% showed resistance to rifampin, and two (3% were resistant to trimethoprim-sulfamethoxazole. MICs with values up to 2μg/ml reinforce the need for microbiological surveillance. CONCLUSIONS: The study demonstrated low prevalence of strains resistant to the antimicrobial drugs indicated in the treatment of human listeriosis. Monitoring antimicrobial resistance profile is still very important to determine adequate treatment, especially in immunocompromised patients.

Combined Surgical Treatment of Gynecomastia

Directory of Open Access Journals (Sweden)

Yordanov Y.

2015-05-01

Full Text Available Surgical treatment of gynecomastia could present unique challenges for the plastic surgeon. Achieving a good balance between effectiveness of the selected approach and the satisfactory aesthetic outcome often is a difficult endeavor. Optimal surgical treatment involves a combination of liposuction and direct excision. In the present study the charts of 11 patients treated with suction-assisted liposuction and direct surgical excision were retrospectively reviewed; a special emphasis is placed on the surgical technique. The mean follow-up period of the patients was 11.6 months. No infection, hematoma, nipple-areola complex necrosis and nipple retraction was encountered in this series. The combined surgical treatment of gynecomastia has shown to be a reliable technique in both small and moderate breast enlargement including those with skin excess.

Antimicrobial Drugs in Fighting against Antimicrobial Resistance

OpenAIRE

Cheng, Guyue; Dai, Menghong; Ahmed, Saeed; Hao, Haihong; Wang, Xu; Yuan, Zonghui

2016-01-01

The outbreak of antimicrobial resistance, together with the lack of newly developed antimicrobial drugs, represents an alarming signal for both human and animal healthcare worldwide. Selection of rational dosage regimens for traditional antimicrobial drugs based on pharmacokinetic/pharmacodynamic principles as well as development of novel antimicrobials targeting new bacterial targets or resistance mechanisms are key approaches in tackling AMR. In addition to the cellular level resistance (i....

Rising prevalence of antimicrobial resistance in urinary tract infections during pregnancy: Necessity for exploring newer treatment options

Directory of Open Access Journals (Sweden)

Meher Rizvi

2011-01-01

antimicrobial susceptibility with safe drugs in pregnant women so that these can be used for the treatment. For empirical treatment cefoperazone-sulbactum can be recommended, which is a safe drug, covering both gram positive and gram negative organisms and with a good sensitivity.

Antimicrobial Activity of Bacteriophage Endolysin Produced in Nicotiana benthamiana Plants.

Science.gov (United States)

Kovalskaya, Natalia; Foster-Frey, Juli; Donovan, David M; Bauchan, Gary; Hammond, Rosemarie W

2016-01-01

The increasing spread of antibiotic-resistant pathogens has raised the interest in alternative antimicrobial treatments. In our study, the functionally active gram-negative bacterium bacteriophage CP933 endolysin was produced in Nicotiana benthamiana plants by a combination of transient expression and vacuole targeting strategies, and its antimicrobial activity was investigated. Expression of the cp933 gene in E. coli led to growth inhibition and lysis of the host cells or production of trace amounts of CP933. Cytoplasmic expression of the cp933 gene in plants using Potato virus X-based transient expression vectors (pP2C2S and pGR107) resulted in death of the apical portion of experimental plants. To protect plants against the toxic effects of the CP933 protein, the cp933 coding region was fused at its Nterminus to an N-terminal signal peptide from the potato proteinase inhibitor I to direct CP933 to the delta-type vacuoles. Plants producing the CP933 fusion protein did not exhibit the severe toxic effects seen with the unfused protein and the level of expression was 0.16 mg/g of plant tissue. Antimicrobial assays revealed that, in contrast to gram-negative bacterium E. coli (BL21(DE3)), the gram-positive plant pathogenic bacterium Clavibacter michiganensis was more susceptible to the plant-produced CP933, showing 18% growth inhibition. The results of our experiments demonstrate that the combination of transient expression and protein targeting to the delta vacuoles is a promising approach to produce functionally active proteins that exhibit toxicity when expressed in plant cells.

Antimicrobial activity of lemongrass oil against Salmonella enterica on organic leafy greens

Science.gov (United States)

In an effort to discover new and natural antimicrobial treatments against Salmonella Newport on organic produce, we evaluated the antimicrobial effect of lemongrass essential oil on four different types of organic leafy greens inoculated with S. Newport. The effects of lemongrass treatment exposure...

Antimicrobial resistance in Acinetobacter baumannii: From bench to bedside

Science.gov (United States)

Lin, Ming-Feng; Lan, Chung-Yu

2014-01-01

Acinetobacter baumannii (A. baumannii) is undoubtedly one of the most successful pathogens in the modern healthcare system. With invasive procedures, antibiotic use and immunocompromised hosts increasing in recent years, A. baumannii has become endemic in hospitals due to its versatile genetic machinery, which allows it to quickly evolve resistance factors, and to its remarkable ability to tolerate harsh environments. Infections and outbreaks caused by multidrug-resistant A. baumannii (MDRAB) are prevalent and have been reported worldwide over the past twenty or more years. To address this problem effectively, knowledge of species identification, typing methods, clinical manifestations, risk factors, and virulence factors is essential. The global epidemiology of MDRAB is monitored by persistent surveillance programs. Because few effective antibiotics are available, clinicians often face serious challenges when treating patients with MDRAB. Therefore, a deep understanding of the resistance mechanisms used by MDRAB can shed light on two possible strategies to combat the dissemination of antimicrobial resistance: stringent infection control and antibiotic treatments, of which colistin-based combination therapy is the mainstream strategy. However, due to the current unsatisfying therapeutic outcomes, there is a great need to develop and evaluate the efficacy of new antibiotics and to understand the role of other potential alternatives, such as antimicrobial peptides, in the treatment of MDRAB infections. PMID:25516853

Delivery systems for antimicrobial peptides

DEFF Research Database (Denmark)

Nordström, Randi; Malmsten, Martin

2017-01-01

Due to rapidly increasing resistance development against conventional antibiotics, finding novel approaches for the treatment of infections has emerged as a key health issue. Antimicrobial peptides (AMPs) have attracted interest in this context, and there is by now a considerable literature...... on the identification such peptides, as well as on their optimization to reach potent antimicrobial and anti-inflammatory effects at simultaneously low toxicity against human cells. In comparison, delivery systems for antimicrobial peptides have attracted considerably less interest. However, such delivery systems...... are likely to play a key role in the development of potent and safe AMP-based therapeutics, e.g., through reducing chemical or biological degradation of AMPs either in the formulation or after administration, by reducing adverse side-effects, by controlling AMP release rate, by promoting biofilm penetration...

Photocatalytic and antimicrobial Ag/ZnO nanocomposites for functionalization of textile fabrics

Energy Technology Data Exchange (ETDEWEB)

Ibănescu, Mariana [Centre of Nanostructures and Functional Materials-CNMF, Faculty of Materials and Environment Engineering, “Dunărea de Jos” University of Galaţi, 111 Domnească Street, 800201 Galaţi (Romania); Muşat, Viorica, E-mail: viorica.musat@ugal.ro [Centre of Nanostructures and Functional Materials-CNMF, Faculty of Materials and Environment Engineering, “Dunărea de Jos” University of Galaţi, 111 Domnească Street, 800201 Galaţi (Romania); Textor, Torsten [Deutsches Textilforschungszentrum Nord-West gGmbH, DTNW, Adlerstr. 1, 47798 Krefeld (Germany); CENIDE, Center for Nanointegration Duisburg-Essen (Germany); Badilita, Viorel [National R and D Institute for Non-ferrous and Rare Metals Nanostructured Materials Laboratory, Ilfov (Romania); Mahltig, Boris [Niederrhein University of Applied Sciences, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany)

2014-10-15

Highlights: • Higher silver doping smaller nanoparticles size and weaker agglomeration. • Higher silver concentration higher optical absorbance and band gap energy. • Small amouts of silver have considerably increased the antimicobial activity. • The photocatalytic activity is consistent with the increase of antimicrobial activity. - Abstract: The utilization of ZnO nanoparticles with photocatalytic and antimicrobial activity for textile treatment has received much attention in recent years. Since silver is a well-known but more expensive antibacterial material, it is of interest to study the extent to which a small amount of silver increases the photocatalytic and antimicrobial activity of the less expensive zinc oxide nanoparticles. This paper reports on the preparation of Ag/ZnO composite nanoparticles by reducing silver on the surface of commercial ZnO nanoparticles dispersed in isopropanol. Crystalline structure, particle size and band gap energy of as-prepared composite nanoparticles were investigated by X-ray diffraction and UV–Vis absorption measurements. Long term stable sols of ZnO and Ag/ZnO nanoparticles were prepared and applied as liquid coating agent for textile treatment, in combination with inorganic–organic hybrid polymer binder sols prepared from the precursors 3-glycidyloxypropyltrimethoxysilane (GPTMS) and tetraethoxysilane (TEOS). The coating process was carried out on cotton fabrics and cotton/polyester blended fabrics using the pad–dry–cure method. The photocatalytic activity of the nanoparticles, as prepared or applied on textile fabrics, was studied through the degradation of the dye methylene blue (MB) in water under the UV irradiation. The antimicrobial activity of the nanoparticles applied on textile fabrics, was tested against the Gram-negative bacterium Escherichia coli and Gram-positive Micrococcus luteus.

Photocatalytic and antimicrobial Ag/ZnO nanocomposites for functionalization of textile fabrics

International Nuclear Information System (INIS)

Ibănescu, Mariana; Muşat, Viorica; Textor, Torsten; Badilita, Viorel; Mahltig, Boris

2014-01-01

Highlights: • Higher silver doping smaller nanoparticles size and weaker agglomeration. • Higher silver concentration higher optical absorbance and band gap energy. • Small amouts of silver have considerably increased the antimicobial activity. • The photocatalytic activity is consistent with the increase of antimicrobial activity. - Abstract: The utilization of ZnO nanoparticles with photocatalytic and antimicrobial activity for textile treatment has received much attention in recent years. Since silver is a well-known but more expensive antibacterial material, it is of interest to study the extent to which a small amount of silver increases the photocatalytic and antimicrobial activity of the less expensive zinc oxide nanoparticles. This paper reports on the preparation of Ag/ZnO composite nanoparticles by reducing silver on the surface of commercial ZnO nanoparticles dispersed in isopropanol. Crystalline structure, particle size and band gap energy of as-prepared composite nanoparticles were investigated by X-ray diffraction and UV–Vis absorption measurements. Long term stable sols of ZnO and Ag/ZnO nanoparticles were prepared and applied as liquid coating agent for textile treatment, in combination with inorganic–organic hybrid polymer binder sols prepared from the precursors 3-glycidyloxypropyltrimethoxysilane (GPTMS) and tetraethoxysilane (TEOS). The coating process was carried out on cotton fabrics and cotton/polyester blended fabrics using the pad–dry–cure method. The photocatalytic activity of the nanoparticles, as prepared or applied on textile fabrics, was studied through the degradation of the dye methylene blue (MB) in water under the UV irradiation. The antimicrobial activity of the nanoparticles applied on textile fabrics, was tested against the Gram-negative bacterium Escherichia coli and Gram-positive Micrococcus luteus

An in-vitro antimicrobial effect of 405 nm laser diode combined with chlorophylls of alfalfa (Medicago sativa L. on Enterococcus faecalis

Directory of Open Access Journals (Sweden)

Suryani Dyah Astuti

2018-03-01

Full Text Available Background: Enterococcus faecalis (E. faecalis is a bacterium commonly detected in the root canals of teeth with post-treatment apical periodontitis or advanced marginal periodontitis. It has the ability to live in an extreme environment and survive as an organism with its virulence factor possibly contributing to the pathogenesis of post-treatment apical and marginal periodontitis. Photodynamic therapy (PDT is an urgently required alternative method of improving therapy effectiveness. Photodynamic therapy combined with conventional endodontic treatment decreases the number of antibioticresistant bacteria and biofilms. Chlorophyll is one of the photosensitizers added to enhance the absorption of light in photodynamic therapy. Purpose: The purpose of this study was to determine the antimicrobial effect of the combination of photodynamic laser therapy and Alfalfa chlorophyll in E. faecalis. Methods: In vitro study using E. faecalis distributed between negative control (C- and positive control (C+, treatment groups using various energy doses of a 405 nm diode laser (2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20 J/cm2 with (G1 and without alfalfa chlorophyll as organic photosensitizer (G2. The suspension was inoculated on Tryptocase Soy Agar (TSA and incubated at 37° C for 24 hours. The number of colonyforming units per milliliter (CFU/ml was determined. The results were analyzed by ANOVA with p value ≤0.05. Results: A 405 nm irradiating laser with or without a photosensitizer can decrease E. faecalis viability percentage through the administering of various energy doses. The highest decrease (42% was obtained in the group without a photosensitizer using 20 J/cm2, while 10 J/cm2 in the group with a photosensitizer proved the most effective dose (25%. Conclusion: The results of this study showed a decrease in the viability of E. faecalis exposed to a 405 nm (40 mW laser. An irradiating process using a 405 nm laser without a photosensitizer (Alfalfa

Antimicrobial Stewardship in Daily Practice: Managing an Important Resource

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Nicole Le Saux

2014-01-01

Full Text Available Antimicrobial stewardship is a recent concept that embodies the practical, judicious use of antimicrobials to decrease adverse outcomes from antimicrobials while optimizing the treatment of bacterial infections to reduce the emergence of resistant pathogens. The objectives of the present statement are to illustrate the principles of antimicrobial stewardship and to offer practical examples of how to make antimicrobial stewardship part of everyday hospital and outpatient practice. Vital components of antimicrobial stewardship include appropriate testing to diagnose whether infections are viral or bacterial, and using clinical follow-up rather than antibiotics in cases in which the child is not very ill and uncertainty exists. Other specific, important actions include questioning whether positive urine cultures are contaminated when there is no evidence of pyuria or inflammatory changes, and obtaining a chest radiograph to support a diagnosis of bacterial pneumonia. Optimizing the choice and dosage of antimicrobials also reduces the probability of clinical failures and subsequent courses of antimicrobials. A list of common clinical scenarios to promote stewardship is included.

Neisseria gonorrhoeae: testing, typing and treatment in an era of increased antimicrobial resistance

NARCIS (Netherlands)

Wind, C.M.

2017-01-01

This thesis discusses the management of Neisseria gonorrhoeae infections while under threat of emerging antimicrobial resistance. It focuses on improved diagnostics, and antimicrobial resistance to current and future therapies. We describe a new method of targeted deferred culture, using nucleic

Synthesis, characterization, antimicrobial activity and molecular ...

African Journals Online (AJOL)

Synthesis, characterization, antimicrobial activity and molecular docking studies of combined pyrazol-barbituric acid pharmacophores. Assem Barakat, Bandar M. Al-Qahtani, Abdullah M. Al-Majid, M. Ali Mohammed Rafi Shaik, Mohamed H.M. Al-Agamy, Abdul Wadood ...

Antimicrobial residual effects of irrigation regimens with maleic acid in infected root canals

OpenAIRE

Ferrer-Luque, Carmen Mar?a; Gonz?lez-Castillo, Silvia; Ruiz-Linares, Matilde; Arias-Moliz, Mar?a Teresa; Rodr?guez-Archilla, Alberto; Baca, Pilar

2015-01-01

Background The success of endodontic treatment depends largely on the control of microorganisms present in infected root canals. The aim of this study was to determine the residual antimicrobial activity of several final irrigation protocols with 7% maleic acid (MA) alone and combined with chlorhexidine (CHX), cetrimide (CTR) or both, in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown in uniradicular roots for 4 weeks. A total of 72 specimens were divided i...

Treatment of mastitis during lactation.

Science.gov (United States)

Pyörälä, S

2009-04-01

Treatment of mastitis should be based on bacteriological diagnosis and take national and international guidelines on prudent use of antimicrobials into account. In acute mastitis, where bacteriological diagnosis is not available, treatment should be initiated based on herd data and personal experience. Rapid bacteriological diagnosis would facilitate the proper selection of the antimicrobial. Treating subclinical mastitis with antimicrobials during lactation is seldom economical, because of high treatment costs and generally poor efficacy. All mastitis treatment should be evidence-based, i.e., the efficacy of each product and treatment length should be demonstrated by scientific studies. Use of on-farm written protocols for mastitis treatment promotes a judicious use of antimicrobials and reduces the use of antimicrobials.

Combined therapeutic use of oral alitretinoin and narrowband ultraviolet-B therapy in the treatment of Hailey-Hailey disease

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Kaitlin A. Vanderbeck

2014-11-01

Full Text Available Hailey-Hailey disease (HHD is a chronic familial bullous disease characterized by recurrent blisters and erosions typically at friction-prone areas of the body accompanied by acantholysis upon histologic examination. There are a number of therapies used in the management of HHD. Its symptoms have been effectively treated with antimicrobial therapies, corticosteroids and other agents such as cyclosporine and prednisone. However, such treatments are not always effective. Therefore, there is a need for new treatments for the management of HHD. In this report, a patient with long-standing HHD responsive only to high levels of prednisone is described. After the successful tapering and cessation of oral prednisone the patient began a new combination therapy of complementary doses of oral alitretinoin, and narrowband UVB therapy, which yielded a favorable response within 2-3 weeks. After 6 weeks, a mono-therapy of daily (30 mg oral alitretinoin was sufficient to maintain successful near-complete remission of the disease.

Novel Antimicrobial Titanium Dioxide Nanotubes Obtained through a Combination of Atomic Layer Deposition and Electrospinning Technologies

Science.gov (United States)

Patiño, Cristian; Galotto, María Jose; Palma, Juan Luis; Alburquenque, Daniela

2018-01-01

The search for new antimicrobial substances has increased in recent years. Antimicrobial nanostructures are one of the most promising alternatives. In this work, titanium dioxide nanotubes were obtained by an atomic layer deposition (ALD) process over electrospun polyvinyl alcohol nanofibers (PVN) at different temperatures with the purpose of obtaining antimicrobial nanostructures with a high specific area. Electrospinning and ALD parameters were studied in order to obtain PVN with smallest diameter and highest deposition rate, respectively. Chamber temperature was a key factor during ALD process and an appropriate titanium dioxide deposition performance was achieved at 200 °C. Subsequently, thermal and morphological analysis by SEM and TEM microscopies revealed hollow nanotubes were obtained after calcination process at 600 °C. This temperature allowed complete polymer removal and influenced the resulting anatase crystallographic structure of titanium dioxide that positively affected their antimicrobial activities. X-ray analysis confirmed the change of titanium dioxide crystallographic structure from amorphous phase of deposited PVN to anatase crystalline structure of nanotubes. These new nanostructures with very large surface areas resulted in interesting antimicrobial properties against Gram-positive and Gram-negative bacteria. Titanium dioxide nanotubes presented the highest activity against Escherichia coli with 5 log cycles reduction at 200 μg/mL concentration. PMID:29495318

Antimicrobial and Biophysical Properties of Surfactant Supplemented with an Antimicrobial Peptide for Treatment of Bacterial Pneumonia

NARCIS (Netherlands)

Banaschewski, Brandon J H; Veldhuizen, Edwin J A; Keating, Eleonora; Haagsman, Henk P; Zuo, Yi Y; Yamashita, Cory M; Veldhuizen, Ruud A W

2015-01-01

BACKGROUND: Antibiotic resistant bacterial infections represent an emerging health concern in clinical settings, and a lack of novel developments in the pharmaceutical pipeline is creating a "perfect storm" for multi-drug resistant bacterial infections. Antimicrobial peptides (AMPs) have been

Use of the Antimicrobial Peptide Sublancin with Combined Antibacterial and Immunomodulatory Activities To Protect against Methicillin-Resistant Staphylococcus aureus Infection in Mice.

Science.gov (United States)

Wang, Shuai; Wang, Qingwei; Zeng, Xiangfang; Ye, Qianhong; Huang, Shuo; Yu, Haitao; Yang, Tianren; Qiao, Shiyan

2017-10-04

Methicillin-resistant Staphylococcus aureus (MRSA) is the major pathogen causing serious hospital infections worldwide. With the emergence and rapid spread of drug-resistant bacteria, there is extraordinary interest in antimicrobial peptides (AMPs) as promising candidates for the treatment of antibiotic-resistant bacterial infections. Sublancin, a glycosylated AMP produced by Bacillus subtilis 168, has been reported to possess protective activity against bacterial infection. This study was performed to evaluate the efficacy of sublancin in the prevention of MRSA ATCC43300 intraperitoneal infection in mice. We determined that sublancin had a minimal inhibitory concentration of 15 μM against MRSA ATCC43300. The antimicrobial action of sublancin involved the destruction of the bacterial cell wall. Dosing of mice with sublancin greatly alleviated (p resistant infections and sepsis.

Statistical metamodeling for revealing synergistic antimicrobial interactions.

Directory of Open Access Journals (Sweden)

Hsiang Chia Chen

2010-11-01

Full Text Available Many bacterial pathogens are becoming drug resistant faster than we can develop new antimicrobials. To address this threat in public health, a metamodel antimicrobial cocktail optimization (MACO scheme is demonstrated for rapid screening of potent antibiotic cocktails using uropathogenic clinical isolates as model systems. With the MACO scheme, only 18 parallel trials were required to determine a potent antimicrobial cocktail out of hundreds of possible combinations. In particular, trimethoprim and gentamicin were identified to work synergistically for inhibiting the bacterial growth. Sensitivity analysis indicated gentamicin functions as a synergist for trimethoprim, and reduces its minimum inhibitory concentration for 40-fold. Validation study also confirmed that the trimethoprim-gentamicin synergistic cocktail effectively inhibited the growths of multiple strains of uropathogenic clinical isolates. With its effectiveness and simplicity, the MACO scheme possesses the potential to serve as a generic platform for identifying synergistic antimicrobial cocktails toward management of bacterial infection in the future.

In vitro methods for the evaluation of antimicrobial surface designs

NARCIS (Netherlands)

Sjollema, Jelmer; Zaat, Sebastian A. J.; Fontaine, Veronique; Ramstedt, Madeleine; Luginbuehl, Reto; Thevissen, Karin; Li, Jiuyi; van der Mei, Henny C.; Busscher, Henk J.

2018-01-01

Bacterial adhesion and subsequent biofilm formation on biomedical implants and devices are a major cause of their failure. As systemic antibiotic treatment is often ineffective, there is an urgent need for antimicrobial biomaterials and coatings. The term "antimicrobial" can encompass different

Etiología bacteriana de la neumonía nosocomial y resistencia a los antimicrobianos en pacientes con y sin tratamiento antimicrobiano previo Bacterial etiology of nosocomial pneumonia and antimicrobial resistance in patients with and without antimicrobial treatment

Directory of Open Access Journals (Sweden)

Beatriz Weyland

2011-03-01

Full Text Available La neumonía nosocomial (NN se asocia a una elevada morbimortalidad y es la segunda causa de infección intrahospitalaria después de la infección urinaria. El objetivo de este trabajo fue conocer la etiología de la NN en adultos y evaluar el perfil de resistencia a los antimicrobianos de los microorganismos aislados teniendo en cuenta si los pacientes recibieron o no tratamiento antimicrobiano previo. Desde el año 2000 hasta el 2005 se analizaron 430 lavados broncoalveolares provenientes de 430 pacientes adultos con diagnóstico de neumonía internados en la unidad de cuidados intensivos del Hospital de Clínicas "José de San Martín". El 74% (199/ 269 de los pacientes con tratamiento previo tuvieron cultivos positivos, mientras que en el grupo sin tratamiento previo esta proporción fue del 83% (134/161 (p = 0,03. Los microorganismos prevalentes fueron Acinetobacter spp., Staphylococcus aureus y Pseudomonas aeruginosa (37,9% ; 21,3% y 20,9% vs. 36,1%; 26,6% y 17,7% en los pacientes con tratamiento previo o sin él, respectivamente; p > 0,05. La resistencia a los antimicrobianos de los citados microorganismos cuando los aislamientos provinieron de pacientes que recibieron antes tratamiento antibiótico fue superior a la encontrada en el grupo de pacientes que no recibió tratamiento previo (p Nosocomial pneumonia (NP is associated with high morbimortality, representing the second cause of nosocomial infection after urinary tract infection. The objective of this work was to become acquainted with the etiology of NP and to evaluate the antimicrobial resistance profile of the isolated microorganisms from adult patients with and without previous antimicrobial treatment admitted in the intensive care unit (ICU. From 2000 to 2005, 430 bronchoalveolar lavages from 430 adult patients diagnosed with pneumonia admitted in the ICU were analyzed. Seventy-four percent (199/ 269 of the patients with previous treatment had positive cultures, whereas in

Antimicrobial Resistance in the Food Chain: A Review

Science.gov (United States)

Verraes, Claire; Van Boxstael, Sigrid; Van Meervenne, Eva; Van Coillie, Els; Butaye, Patrick; Catry, Boudewijn; de Schaetzen, Marie-Athénaïs; Van Huffel, Xavier; Imberechts, Hein; Dierick, Katelijne; Daube, George; Saegerman, Claude; De Block, Jan; Dewulf, Jeroen; Herman, Lieve

2013-01-01

Antimicrobial resistant zoonotic pathogens present on food constitute a direct risk to public health. Antimicrobial resistance genes in commensal or pathogenic strains form an indirect risk to public health, as they increase the gene pool from which pathogenic bacteria can pick up resistance traits. Food can be contaminated with antimicrobial resistant bacteria and/or antimicrobial resistance genes in several ways. A first way is the presence of antibiotic resistant bacteria on food selected by the use of antibiotics during agricultural production. A second route is the possible presence of resistance genes in bacteria that are intentionally added during the processing of food (starter cultures, probiotics, bioconserving microorganisms and bacteriophages). A last way is through cross-contamination with antimicrobial resistant bacteria during food processing. Raw food products can be consumed without having undergone prior processing or preservation and therefore hold a substantial risk for transfer of antimicrobial resistance to humans, as the eventually present resistant bacteria are not killed. As a consequence, transfer of antimicrobial resistance genes between bacteria after ingestion by humans may occur. Under minimal processing or preservation treatment conditions, sublethally damaged or stressed cells can be maintained in the food, inducing antimicrobial resistance build-up and enhancing the risk of resistance transfer. Food processes that kill bacteria in food products, decrease the risk of transmission of antimicrobial resistance. PMID:23812024

Antimicrobially Treated Projects for Military Use

National Research Council Canada - National Science Library

Swofford, Wayne; Hanrahan, William; Centola, Duane; Isenhour, Crystal; Smith, Hoshus; Ramey, David; Chandler, Jeff

2007-01-01

... desired in combat environments. The objective of this research was to identify, incorporate, and evaluate emerging and promising, commercially available antimicrobial treatments/technologies on military items to provide...

Evaluation of the Combined Therapy of DA-7218, a New Oxazolidinone, and Trimethoprim/ Sulfamethoxazole in the Treatment of Experimental Actinomycetoma by Nocardia brasiliensis.

Science.gov (United States)

Espinoza-Gonzalez, N A; Welsh, O; Ocampo-Candiani, J; Said-Fernandez, S; Lozano-Garza, G; Choi, S H; Vera-Cabrera, L

2010-07-01

Currently, for actinomycetoma, combined antimicrobial therapy is preferred to the use of a single compound. This is in order to provide a broader-spectrum coverage due to a combinatory or synergistic effect between the drugs, and to decrease the possibility of emergence of natural resistant strains. A new oxazolidinone pro-drug, DA-7218 [(R)-3-(4-(2-(2-methyltetrazol-5-yl)-pyridin-5-yl)-3-fluorophenyl)-2-oxo-5-oxazolidinyl) methyl-disodium-phosphate] (recently re-named TR-701), has shown very good in vitro and in vivo activities against several gram-positive bacteria including Nocardia spp. In the present work we evaluated the effect of DA-7218 at two different doses, alone and combined with trimethoprim/ sulfamethoxazole (SXT), in an experimental Nocardia brasiliensis actinomycetoma murine model. We also included a negative and a positive control group (linezolid and saline solution respectively). At the end of the treatment period, we observed a clinically and statistically significant difference among the drug receiving groups (combined, alone and linezolid) and the control group (P=0.004). The difference was higher (P= 0.004) between the groups receiving DA-7218 (25mg/kg) alone or combined with SXT, and the control group (saline solution). In this work we proved that DA-7218 alone and combined with SXT is effective in the treatment of experimental actinomycetoma by Nocardia brasiliensis and that it could be potentially useful in the treatment of human actinomycetoma.

Antimicrobial agents from Licaria puchuri-major and their synergistic effect with polygodial.

Science.gov (United States)

Himejima, M; Kubo, I

1992-05-01

The resistance of the seeds of Licaria puchuri-major (Lauraceae) to decomposition in nature seems to be due largely to chemical defense, since its n-hexane extract contains antimicrobial principles in quantity, with a broad antimicrobial spectrum. In order to identify the active principles, the n-hexane extract was steam-distilled to yield a distillate and a residue. Subsequent bioassay indicated that the distillate retained the original broad antimicrobial activity, while the residue exhibited almost no activity. Gc-ms analysis showed that the distillate contained four phenolic compounds, seven monoterpenes, and one sesquiterpene. In contrast, the residue contained, almost exclusively, lauric acid. In the detailed antimicrobial assay with the pure compounds identified, most of them showed broad, but moderate, antimicrobial activity. Some of the components identified in the distillate were combined with polygodial [1] in order to enhance their antifungal activity. Unexpectedly, while polygodial did not synergize the antifungal activity of any of the compounds tested, the antifungal activity of polygodial was significantly increased when combined with aromatic substances such as anethole, safrole, or methyleugenol.

What Happens When "Germs Don't Get Killed and They Attack Again and Again": Perceptions of Antimicrobial Resistance in the Context of Diarrheal Disease Treatment Among Laypersons and Health-Care Providers in Karachi, Pakistan.

Science.gov (United States)

Joseph, Heather A; Agboatwalla, Mubina; Hurd, Jacqueline; Jacobs-Slifka, Kara; Pitz, Adam; Bowen, Anna

2016-07-06

In south Asia, where diarrhea is common and antibiotics are accessible without prescription, antimicrobial resistance is an emerging and serious problem. However, beliefs and behaviors related to antimicrobial resistance are poorly understood. We explored laypersons' and health-care providers' (HCP) awareness and perceptions of antimicrobial resistance in the context of treatment of adult diarrheal disease in Karachi, Pakistan. In-depth, open-ended interviews were conducted with 40 laypersons and 45 HCPs in a lower-middle-class urban neighborhood. Interviews conducted in Urdu were audiotaped, transcribed, translated, and coded using applied thematic analysis. Slightly over half of laypersons and two-thirds of HCPs were aware that antimicrobial medication could lose effectiveness, but misperceptions were common. Laypersons and HCPs often believed that "the body becomes immune" or "bacteria attack more strongly" if medications are taken "improperly." Another prevalent theme was that causes and effects of antimicrobial resistance are limited to the individual taking the antimicrobial medication and to the specific diarrheal episode. Participants often attributed antimicrobial resistance to patient behaviors; HCP behavior was rarely discussed. Less than half of the HCPs were aware of treatment guidelines. To combat antimicrobial resistance in urban Pakistan, a health systems strategy and community-supported outreach campaigns on appropriate antimicrobial use are needed. © The American Society of Tropical Medicine and Hygiene.

Inhibition of toxinogenesis of type a Clostridium botulinum in beef using combined treatments

International Nuclear Information System (INIS)

Lasta, J.A.; Rodriguez, H.R.; Pensel, N.A.; Margaria, C.A.; Gallinger, M.M.; Artuso, C.A.; Masana, M.O.; Suarez-Rebollo, M.P.

1998-01-01

A shelf stable beef product was developed on the basis of combined treatments involving a reduction in water activity and using specific anti-microbial agents, thermal processing, vacuum packaging and irradiation. Beef foreshanks were cured, thermally processed and irradiated at 7.5 and 15 kGy. Sensory analysis and microbiological, chemical and lipid stability studies were carried out on the non-inoculated samples. In addition, challenge studies involving samples inoculated with 10 3 or 10 5 spores of Clostridium botulinum/g were performed. The samples challenged with 10 3 spores of C. botulinum and irradiated with 15 kGy did not show toxin production during a storage time of 8 months at 28 deg. C. The non-challenged samples showed low 2-thiobarbituric acid numbers and a significant decrease in residual nitrite during storage. Sensory studies carried out by a trained panel indicated that these samples developed some mild off-flavours, which diminished as the storage time increased, and showed good overall acceptance. Studies to introduce a further safety factor, by adding sodium propionate, are currently in progress. (author)

Global trends in antimicrobial use in food animals

Science.gov (United States)

Van Boeckel, Thomas P.; Brower, Charles; Gilbert, Marius; Grenfell, Bryan T.; Levin, Simon A.; Robinson, Timothy P.; Teillant, Aude; Laxminarayan, Ramanan

2015-01-01

Demand for animal protein for human consumption is rising globally at an unprecedented rate. Modern animal production practices are associated with regular use of antimicrobials, potentially increasing selection pressure on bacteria to become resistant. Despite the significant potential consequences for antimicrobial resistance, there has been no quantitative measurement of global antimicrobial consumption by livestock. We address this gap by using Bayesian statistical models combining maps of livestock densities, economic projections of demand for meat products, and current estimates of antimicrobial consumption in high-income countries to map antimicrobial use in food animals for 2010 and 2030. We estimate that the global average annual consumption of antimicrobials per kilogram of animal produced was 45 mg⋅kg−1, 148 mg⋅kg−1, and 172 mg⋅kg−1 for cattle, chicken, and pigs, respectively. Starting from this baseline, we estimate that between 2010 and 2030, the global consumption of antimicrobials will increase by 67%, from 63,151 ± 1,560 tons to 105,596 ± 3,605 tons. Up to a third of the increase in consumption in livestock between 2010 and 2030 is imputable to shifting production practices in middle-income countries where extensive farming systems will be replaced by large-scale intensive farming operations that routinely use antimicrobials in subtherapeutic doses. For Brazil, Russia, India, China, and South Africa, the increase in antimicrobial consumption will be 99%, up to seven times the projected population growth in this group of countries. Better understanding of the consequences of the uninhibited growth in veterinary antimicrobial consumption is needed to assess its potential effects on animal and human health. PMID:25792457

Antimicrobial activity of PVP from an Antarctic bacterium, Janthinobacterium sp. Ant5-2, on multi-drug and methicillin resistant Staphylococcus aureus

KAUST Repository

Huang, Jonathan P.

2012-04-11

Multiple drug resistant (MDR) and methicillin-resistant Staphylococcus aureus (MRSA) have become increasingly prevalent as a community acquired infection. As a result limited treatment options are available with conventional synthetic antibiotics. Bioprospecting natural products with potent antimicrobial activity show promise for developing new drugs against this pathogen. In this study, we have investigated the antimicrobial activity of a purple violet pigment (PVP) from an Antarctic bacterium, Janthinobacterium sp. Ant5-2 on 15 clinical MDR and MRSA strains. The colorimetric resazurin assay was employed to determine the minimum inhibitory concentration (MIC90) of PVP against MDR and MRSA. The MIC90 ranged between 1.57 µg/mL and 3.13 µg/mL, which are significantly lower than many antimicrobials tested from natural sources against this pathogen. The spectrophotometrically determined growth analysis and total microscopic counts using Live/dead® BacLight™ fluorescent stain exhibited a steady decrease in viability of both MDR and MRSA cultures following treatment with PVP at the MIC levels. In silico predictive molecular docking study revealed that PVP could be a DNA-targeting minor groove binding antimicrobial compound. The continued development of novel antimicrobials derived from natural sources with the combination of a suite of conventional antibiotics could stem the rising pandemic of MDR and MRSA along with other deadly microbial pathogens.

Antimicrobial activity of PVP from an Antarctic bacterium, Janthinobacterium sp. Ant5-2, on multi-drug and methicillin resistant Staphylococcus aureus

KAUST Repository

Huang, Jonathan P.; Mojib, Nazia; Goli, Rakesh R.; Watkins, Samantha; Waites, Ken B.; Ravindra, Rasik; Andersen, Dale T.; Bej, Asim K.

2012-01-01

Multiple drug resistant (MDR) and methicillin-resistant Staphylococcus aureus (MRSA) have become increasingly prevalent as a community acquired infection. As a result limited treatment options are available with conventional synthetic antibiotics. Bioprospecting natural products with potent antimicrobial activity show promise for developing new drugs against this pathogen. In this study, we have investigated the antimicrobial activity of a purple violet pigment (PVP) from an Antarctic bacterium, Janthinobacterium sp. Ant5-2 on 15 clinical MDR and MRSA strains. The colorimetric resazurin assay was employed to determine the minimum inhibitory concentration (MIC90) of PVP against MDR and MRSA. The MIC90 ranged between 1.57 µg/mL and 3.13 µg/mL, which are significantly lower than many antimicrobials tested from natural sources against this pathogen. The spectrophotometrically determined growth analysis and total microscopic counts using Live/dead® BacLight™ fluorescent stain exhibited a steady decrease in viability of both MDR and MRSA cultures following treatment with PVP at the MIC levels. In silico predictive molecular docking study revealed that PVP could be a DNA-targeting minor groove binding antimicrobial compound. The continued development of novel antimicrobials derived from natural sources with the combination of a suite of conventional antibiotics could stem the rising pandemic of MDR and MRSA along with other deadly microbial pathogens.

Antimicrobial activity of Agave sisalana

African Journals Online (AJOL)

STORAGESEVER

2009-11-16

Nov 16, 2009 ... cancer treatment, transplantation or are immuno- suppressed for ... machine after the decortication process of the leaves of A. sisalana in a sisal .... Composition and antimicrobial activity of the essential oils of two Origanum ...

Treatment of mastitis during lactation

Directory of Open Access Journals (Sweden)

Pyörälä S

2009-04-01

Full Text Available Abstract Treatment of mastitis should be based on bacteriological diagnosis and take national and international guidelines on prudent use of antimicrobials into account. In acute mastitis, where bacteriological diagnosis is not available, treatment should be initiated based on herd data and personal experience. Rapid bacteriological diagnosis would facilitate the proper selection of the antimicrobial. Treating subclinical mastitis with antimicrobials during lactation is seldom economical, because of high treatment costs and generally poor efficacy. All mastitis treatment should be evidence-based, i.e., the efficacy of each product and treatment length should be demonstrated by scientific studies. Use of on-farm written protocols for mastitis treatment promotes a judicious use of antimicrobials and reduces the use of antimicrobials.

Antimicrobially Treated Projects for Military Use

National Research Council Canada - National Science Library

Swofford, Wayne; Hanrahan, William; Centola, Duane; Isenhour, Crystal; Smith, Hoshus; Ramey, David; Chandler, Jeff

2007-01-01

Antimicrobial treatment of clothing and other textile gear is intended to provide advanced protection to the Warfighter in the field by controlling microorganisms that cause problems ranging from odor...

Evaluation of natural antimicrobials on typical meat spoilage bacteria in vitro and in vacuum-packed pork meat.

Science.gov (United States)

Schirmer, Bjørn Christian; Langsrud, Solveig

2010-03-01

The aim of this study was to investigate the inhibitory effect of natural antimicrobials on the growth of typical spoilage bacteria from marinated pork. Minimum inhibitory concentrations (MIC) of thymol, cinnamaldehyde, allyl isothiocyanate, citric acid, ascorbic acid, a rosemary extract, and a grapefruit seed extract against Lactobacillus algidus, Leuconostoc mesenteroides, Leuconostoc carnosum, Carnobacterium maltaromaticum, Carnobacterium divergens, Brochothrix thermosphacta, and Serratia proteamaculans were determined in a microplate assay. Combinations of antimicrobials were tested and several combinations showed synergistic effects in inhibiting bacterial growth. Single and combined antimicrobials were added to vacuum-packed pork meat to evaluate preserving effects. Antimicrobial concentrations of up to 10 times the MIC values showed no effect on total bacterial growth in vacuum packed pork meaning that although most antimicrobials inhibited the growth of spoilage bacteria in vitro, results from the microplate assay could not be transferred to the meat system. Most natural antimicrobials possess strong odor and flavor that limit their use as a food preservative. In conclusion, this study showed that the use of natural antimicrobials in meat products is limited and that bacterial quality and shelf life was not enhanced under the chosen conditions.

Susceptibility of Pediococcus isolates to antimicrobial compounds in relation to hop-resistance and beer-spoilage.

Science.gov (United States)

Haakensen, Monique; Vickers, David M; Ziola, Barry

2009-09-07

Though important in the context of food microbiology and as potential pathogens in immuno-compromised humans, bacterial isolates belonging to the genus Pediococcus are best known for their association with contamination of ethanol fermentation processes (beer, wine, or fuel ethanol). Use of antimicrobial compounds (e.g., hop-compounds, Penicillin) by some industries to combat Pediococcus contaminants is long-standing, yet knowledge about the resistance of pediococci to antimicrobial agents is minimal. Here we examined Pediococcus isolates to determine whether antibiotic resistance is associated with resistance to hops, presence of genes known to correlate with beer spoilage, or with ability to grow in beer. Lactic acid bacteria susceptibility test broth medium (LSM) used in combination with commercially available GPN3F antimicrobial susceptibility plates was an effective method for assessing antimicrobial susceptibility of Pediococcus isolates. We report the finding of Vancomycin-susceptible Pediococcus isolates from four species. Interestingly, we found that hop-resistant, beer-spoilage, and beer-spoilage gene-harbouring isolates had a tendency to be more susceptible, rather than more resistant, to antimicrobial compounds. Our findings indicate that the mechanisms involved in conferring hop-resistance or ability to spoil beer by Pediococcus isolates are not associated with resistance to antibiotics commonly used for treatment of human infections. Also, Vancomycin-resistance was found to be isolate-specific and not intrinsic to the genus as previously believed.

Antimicrobial activity of tempeh gembus hydrolyzate

Science.gov (United States)

Noviana, A.; Dieny, F. F.; Rustanti, N.; Anjani, G.; Afifah, D. N.

2018-02-01

Tropical disease can be prevented by consumming fermented foods that have antimicrobial activity. One of them is tempeh gembus that has short shelf life. It can be overcome by processing it into hydrolyzate. This study aimed to determine antimicrobial activity of tempeh gembus hydrolyzate. Tempeh gembus was made of local soybean from Grobogan. They were added 5,000 ppm, 8,000 ppm, and 10,000 ppm of bromelain enzyme (TGH BE). Antimicrobial effects of TGH BE were tested against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Steptococcus mutans. Antimicrobial test was carried out using Kirby-Bauer Disc Diffussion method. Soluble protein test used Bradford method. The largest inhibition zone against S. aureus and S. mutans were shown by TGH BE 8,000 ppm, 0.89±0.53 mm and 2.40±0.72 mm. The largest inhibition zone of B. subtilis, 7.33±2,25 mm, was shown by TGH BE 5,000 ppm. There wasn’t antimicrobial effect of TGH BE against E. coli. There weren’t significant differences of soluble protein (P=0.293) and the inhibition zones againt S. aureus (P = 0.967), E. coli (P = 1.000), B. subtilis (P = 0.645), S. mutans (P=0.817) of all treatments. There were antimicrobial activities of TGH BE against S. aureus, B. subtilis, and S. mutans.

Primary care treatment guidelines for skin infections in Europe: congruence with antimicrobial resistance found in commensal Staphylococcus aureus in the community

NARCIS (Netherlands)

van Bijnen, E.M.E.; Paget, W.J.; den Heijer, C.D.J.; Stobberingh, E.E.; Bruggeman, C.A.; Schellevis, F.G.

2014-01-01

Background: Over 90% of antibiotics for human use in Europe are prescribed in primary care. We assessed the congruence between primary care treatment guidelines for skin infections and commensal Staphylococcus aureus (S. aureus) antimicrobial resistance levels in community-dwelling persons. Methods:

Primary care treatment guidelines for skin infections in Europe: congruence with antimicrobial resistance found in commensal Staphylococcus aureus in the community.

NARCIS (Netherlands)

Bijnen, E.M.E. van; Paget, W.J.; Heijer, C.D.J. den; Stobberingh, E.E.; Bruggeman, C.A.; Schellevis, F.G.

2014-01-01

Background: Over 90% of antibiotics for human use in Europe are prescribed in primary care. We assessed the congruence between primary care treatment guidelines for skin infections and commensal Staphylococcus aureus (S. aureus) antimicrobial resistance levels in community-dwelling persons. Methods:

Antimicrobial prescribing behaviour in dogs and cats by Belgian veterinarians.

Science.gov (United States)

Van Cleven, Alexia; Sarrazin, Steven; de Rooster, Hilde; Paepe, Dominique; Van der Meeren, Sofie; Dewulf, Jeroen

2018-03-17

The objective of this study is to survey general prescribing behaviour by Belgian companion animal veterinarians and to assess agreement of these practices with current treatment guidelines. Therefore an online survey was administered with five realistic and frequently occurring first-line cases to primary-care veterinary practitioners. For each case a predefined pattern of questions were asked about whether or not they would prescribe antimicrobials, if they would prescribe a non-antimicrobial treatment and if they would perform additional diagnostic steps. The responses were compared with recommendations in national guidelines and recent literature. The overall most prescribed antimicrobials were potentiated amoxicillin (43.0 per cent), fluoroquinolones (14.7 per cent), third-generation and fourth-generation cephalosporins (10.9 per cent) and tetracyclines (10.9 per cent). Only 48.3 per cent of the veterinarians complied with the guidelines in nearly all of the clinical scenarios (ie, prescribing antimicrobials when indicated, not prescribing antimicrobials when it is not indicated). Moreover, when prescribing highest priority critically important antimicrobials, susceptibility testing on bacterial cultures was performed in only 12.4 per cent of the prescriptions. The results showed that the prescribing behaviour of antimicrobial compounds by primary-care veterinary practitioners in dogs and cats is often not in agreement with national guidelines. Focus in improvement of this prescribing behaviour should be on performing the appropriate diagnostic steps and decreasing the use of highest priority critically important antimicrobials. © British Veterinary Association (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Advances in pharmacovigilance initiatives surrounding antimicrobial resistance-Indian perspective.

Science.gov (United States)

Bairy, Laxminarayana Kurady; Nayak, Veena; A, Avinash; Kunder, Sushil Kiran

2016-08-01

In recent years the development of antimicrobial resistance has been accelerating, the discovery of new antimicrobial agents has slowed substantially in past decades. This review mainly focuses on the problem of antimicrobial resistance(AMR); the various contributor mechanisms, consequences and future of AMR. The review also highlights the irrational use of antimicrobials, improving their usage and problems associated with pharmacovigilance of antimicrobial resistance. Pharmacovigilance in the form of surveillance of antibiotic use is being done in 90% of the countries worldwide through the WHONET program developed by WHO. However, the data comes from a limited area of the globe. Data from every part of the world is required, so that there is geographical representation of every region. A major hurdle in quantifying the extent of antimicrobial resistance is the fact that there are several known microbes, that may turn out to be resistant to one or more of the several known antimicrobial agents. The global action plan initiated by WHO, if implemented successfully will definitely reduce AMR and will help in evaluating treatment interventions.

Miniaturized Antimicrobial Susceptibility Test by Combining Concentration Gradient Generation and Rapid Cell Culturing

Directory of Open Access Journals (Sweden)

Samuel C. Kim

2015-10-01

Full Text Available Effective treatment of bacterial infection relies on timely diagnosis and proper prescription of antibiotic drugs. The antimicrobial susceptibility test (AST is one of the most crucial experimental procedures, providing the baseline information for choosing effective antibiotic agents and their dosages. Conventional methods, however, require long incubation times or significant instrumentation costs to obtain test results. We propose a lab-on-a-chip approach to perform AST in a simple, economic, and rapid manner. Our assay platform miniaturizes the standard broth microdilution method on a microfluidic device (20 × 20 mm that generates an antibiotic concentration gradient and delivers antibiotic-containing culture media to eight 30-nL chambers for cell culture. When tested with 20 μL samples of a model bacterial strain (E. coli ATCC 25922 treated with ampicillin or streptomycin, our method allows for the determination of minimum inhibitory concentrations consistent with the microdilution test in three hours, which is almost a factor of ten more rapid than the standard method.

Biodegradable polylactic acid polymer with nisin for use in antimicrobial food packaging.

Science.gov (United States)

Jin, T; Zhang, H

2008-04-01

Biodegradable polylactic acid (PLA) polymer was evaluated for its application as a material for antimicrobial food packaging. PLA films were incorporated with nisin to for control of foodborne pathogens. Antimicrobial activity of PLA/nisin films against Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Enteritidis were evaluated in culture media and liquid foods (orange juice and liquid egg white). Scanned electron micrograph and confocal laser microscopy revealed that nisin particles were evenly distributed in PLA polymer matrix on the surface and inside of the PLA/nisin films. PLA/nisin significantly inhibited growth of L. monocytogenes in culture medium and liquid egg white. The greatest inhibition occurred at 24 h when the cell counts of L. monocytogenes in the PLA/nisin samples were 4.5 log CFU/mL less than the controls. PLA/nisin reduced the cell population of E. coli O157:H7 in orange juice from 7.5 to 3.5 log at 72 h whereas the control remained at about 6 log CFU/mL. PLA/nisin treatment resulted in a 2 log reduction of S. Enteritidis in liquid egg white at 24 degrees C. After 21 d at 4 degrees C the S. Enteritidis population from PLA/nisin treated liquid egg white (3.5 log CFU/mL) was significantly less than the control (6.8 log CFU/mL). E. coli O157:H7 in orange juice was more sensitive to PLA/nisin treatments than in culture medium. The results of this research demonstrated the retention of nisin activity when incorporated into the PLA polymer and its antimicrobial effectiveness against foodborne pathogens. The combination of a biopolymer and natural bacteriocin has potential for use in antimicrobial food packaging.

Novel Treatment of Staphylococcus aureus Device-Related Infections Using Fibrinolytic Agents.

Science.gov (United States)

Hogan, S; O'Gara, J P; O'Neill, E

2018-02-01

Staphylococcal infections involving biofilms represent a significant challenge in the treatment of patients with device-related infections. Staphylococcus aureus biofilms have been shown to be SaeRS regulated and dependent on the coagulase-catalyzed conversion of fibrinogen into fibrin on surfaces coated with human plasma. Here we investigated the treatment of staphylococcal biofilm device-related infections by digesting the fibrin biofilm matrix with and without existing antimicrobials. The fibrinolytic agents plasmin, streptokinase, and nattokinase, and TrypLE, a recombinant trypsin-like protease, were used to digest and treat S. aureus biofilms grown in vitro using in vivo -like static biofilm assays with and without antimicrobials. Cytotoxicity, the potential to induce a cytokine response in whole human blood, and the risk of induction of tolerance to fibrinolytic agents were investigated. A rat model of intravascular catheter infection was established to investigate the efficacy of selected fibrinolytic agents in vivo Under biomimetic conditions, the fibrinolytic agents effectively dispersed established S. aureus biofilms and, in combination with common antistaphylococcal antimicrobials, effectively killed bacterial cells being released from the biofilm. These fibrinolytic agents were not cytotoxic and did not affect the host immune response. The rat model of infection successfully demonstrated the activity of the selected fibrinolytic agents alone and in combination with antimicrobials on established biofilms in vivo TrypLE and nattokinase most successfully removed adherent cells from plasma-coated surfaces and significantly improved the efficacy of existing antimicrobials against S. aureus biofilms in vitro and in vivo These biofilm dispersal agents represent a viable future treatment option for S. aureus device-related infections. Copyright © 2018 American Society for Microbiology.

[Etiology of urinary tract infections and antimicrobial susceptibility of urinary pathogens].

Science.gov (United States)

Correia, Carlos; Costa, Elísio; Peres, António; Alves, Madalena; Pombo, Graça; Estevinho, Letícia

2007-01-01

With the objective of knowing the common etiological agents in urinary infection and comparing its antimicrobial susceptibility in nosocomial and community-acquired urinary infections, we analyse all the urine bacteriological exams from the Serviço de Patologia Clínica do Centro Hospitalar do Nordeste, EPE - Unidade Hospitalar de Bragança, during a two years period (April 2004 to March 2006). During this period, 4018 urine bacteriological exams were made. The cultural exam was positive in 572 samples (144 from nosocomial infections and 428 from community-acquired urinary infections). The Escherichia coli was the more isolated strain (68,4 %), followed by Klebsiella spp (7,9%), Pseudomonas aeruginosa (6,1%) and Proteus mirabilis (5,2%). Concerning to antimicrobial susceptibility, Escherichia coli and Klebsiella spp showed a high resistance to the antimicrobials Amoxicillin, Piperacillin, Cephalothin, Ceftazidim and Quinolones. For Enterobacteriaceae Imipenem, Amikacin and Netilmicin were the antimicrobials with more level of susceptibility. Imipenem and Amikacin were the more efficient antimicrobials against Pseudomonas aeruginosa. Concerning to the susceptibility for the same etiological agent, in nosocomial and community-acquired urinary infections, we founded statistical significant differences in the antimicrobials Ticarcillin-clavulanic acid and Collistin for Pseudomonas aeruginosa and in the group of antimicrobials from Quinolones for the Proteus mirabilis. In the other identified agents there were no statistical significant differences for antimicrobials. This study it allows making use of data necessary for the knowledge of etiologic urinary infection agents in Bragança and provides the information about the antimicrobials resistance, which were necessary to initiate an adequate empirical treatment and to elaborate treatment guides.

A bioengineered nisin derivative, M21A, in combination with food grade additives eradicates biofilms of Listeria monocytogenes.

Directory of Open Access Journals (Sweden)

Lorraine Anne Draper

2016-11-01

Full Text Available The burden of foodborne disease has large economic and social consequences worldwide. Despite strict regulations, a number of pathogens persist within the food environment, which is greatly contributed to by a build-up of resistance mechanisms and also through the formation of biofilms. Biofilms have been shown to be highly resistant to a number of antimicrobials and can be extremely difficult to remove once they are established. In parallel, the growing concern of consumers regarding the use of chemically derived antimicrobials within food has led to a drive towards more natural products. As a consequence, the use of naturally derived antimicrobials has become of particular interest. In this study we investigated the efficacy of nisin A and its bioengineered derivative M21A in combination with food grade additives to treat biofilms of a representative strain of Listeria monocytogenes. Investigations revealed the enhanced antimicrobial effects, in liquid culture, of M21A in combination with citric acid or cinnamaldehyde over its wild type nisin A counterpart. Subsequently, an investigation was conducted into the effects of these combinations on an established biofilm of the same strain. Nisin M21A (0.1 µg/ml alone or in combination with cinnamaldehyde (35 µg/ml or citric acid (175 µg/ml performed significantly better than combinations involving nisin A. All combinations of M21A with either citric acid or cinnamaldehyde eradicated the L. monocytogenes biofilm (in relation to a non-biofilm control. We conclude that M21A in combination with available food additives could further enhance the antimicrobial treatment of biofilms within the food industry, simply by substituting nisin A with M21A in current commercial products such as Nisaplin (Danisco, DuPont.

A Novel Trp-rich Model Antimicrobial Peptoid with Increased Protease Stability

International Nuclear Information System (INIS)

Bang, Jeong Kyu; Nan, Yong Hai; Lee, Eun Kyu; Shin, Song Yub

2010-01-01

In order to increase protease stability of a novel Trp-rich model antimicrobial peptide, K 6 L 2 W 3 (KLWKKWKKWLKNH 2 ) and investigate the effect of L-amino acid to peptoid residue conversion on biological functions, we synthesized its antimicrobial peptoid, k 6 l 2 w 3 . Peptoid k 6 l 2 w 3 had similar bacterial selectivity compared to peptide K 6 L 2 W 3 . The bactericidal rate of k 6 l 2 w 3 was somewhat slower than that of K 6 L 2 W 3 . Peptoid k 6 l 2 w 3 exhibited very little dye leakage from bacterial outer-membrane mimicking PE/PG liposomes, as observed in K 6 L 2 W 3 , indicating that the major target site of K 6 L 2 W 3 and k 6 l 2 w 3 may be not the cell membrane but the cytoplasm of bacteria. Trypsin treatment of K 6 L 2 W 3 completely abolished antimicrobial activities against Escherichia coli and Staphylococcus aureus. In contrast, the antimicrobial activity of k 6 l 2 w 3 was completely preserved after trypsin treatment. Taken together, our results suggested that antimicrobial peptoid k 6 l 2 w 3 can potentially serves as a promising therapeutic agent for the treatment of microbial infection

Antimicrobial commodities. 7. Biocide for water treatment; Kokin seikatsu yohin. 7. Suraimu control zai no kokin bo kabi sayo

Energy Technology Data Exchange (ETDEWEB)

Sugi, T. [Kurita Water Industries Ltd., Tokyo (Japan)

1998-10-01

Outlined in this report are microbe-caused troubles that happen in manufacturing processes particularly in water treatment systems, measures for dealing with such troubles, and the antimicrobial and fungicidal functions presented by slime inhibiting agents. In heat exchangers in production lines in chemical and iron-making industries, and in paper making processes in paper and pulp industry, deposits, called slime and composed mainly of microbes, occur to cause various troubles such as reduction in production efficiency. In general, vermicides and multiplication depressants are used for the prevention and removal of slime deposition. They include chlorine gas, sodium hypochlorite, chlorinated isocyanuric acid, and dibromohydantoin, which are used for slime control mainly in cooling water systems. Slime inhibitors are needed for paper pulp, antiseptic agents with its effect lasting long are required for industrial production, and, in small cooling towers where chlorine management is demanding, antimicrobial agents of the organic nature are used. In case water treatment is inappropriately performed, troubles may be caused by Legionella microbes, for whose destruction chemical-aided washing is necessary. (NEDO)

Human Health Hazards from Antimicrobial-Resistant Escherichia coli of Animal Origin

DEFF Research Database (Denmark)

Hammerum, A. M.; Heuer, Ole Eske

2009-01-01

of antimicrobial agents in food animals may add to the burden of antimicrobial resistance in humans. Bacteria from the animal reservoir that carry resistance to antimicrobial agents that are regarded as highly or critically important in human therapy (e.g., aminoglycosides, fluoroquinolones, and third- and fourth......Because of the intensive use of antimicrobial agents in food animal production, meat is frequently contaminated with antimicrobial-resistant Escherichia coli. Humans can be colonized with E. coli of animal origin, and because of resistance to commonly used antimicrobial agents, these bacteria may...... cause infections for which limited therapeutic options are available. This may lead to treatment failure and can have serious consequences for the patient. Furthermore, E. coli of animal origin may act as a donor of antimicrobial resistance genes for other pathogenic E. coli. Thus, the intensive use...

Inactivation of Listeria in Foods Packed in Films Activated with Enterocin AS-48 plus Thymol Singly or in Combination with High-Hydrostatic Pressure Treatment

Directory of Open Access Journals (Sweden)

Irene Ortega Blázquez

2017-11-01

Full Text Available The aim of the present study was to determine the efficacy of films activated with enterocin AS-48 plus thymol singly, or in combination with high-hydrostatic pressure (HHP on the inactivation of Listeria innocua in sea bream fillets and in fruit puree stored under refrigeration for 10 days. L. innocua proliferated in control fish fillets during storage. The activated film reduced viable Listeria counts in fillets by 1.76 log cycles and prevented growth of survivors until mid-storage. Application of HHP treatment to fillets packed in films without antimicrobials reduced Listeria counts by 1.83 log cycles, but did not prevent the growth of survivors during storage. The combined treatment reduced viable counts by 1.88 log cycles and delayed growth of survivors during the whole storage period. L. innocua survived in puree during storage. The activated film reduced Listeria counts by 1.80 and 2.0 log cycles at days 0 and 3. After that point, Listeria were below the detection limit. No viable Listeria were detected in the purees after application of HHP treatment singly, or in combination with the activated film. Results from the study indicate that the efficacy of activated films against Listeria is markedly influenced by the food type.

IMPLICATION OF THE FIXED COMBINATIONS IN THE HYPERTENSION TREATMENT

Directory of Open Access Journals (Sweden)

Z. D. Kobalava

2010-01-01

Full Text Available The role of fixed combinations in the hypertension (HT treatment is discussed. Theoretical and practical aspects of combination therapy, principles of rational combination therapy are present. Current guidelines on the use of fixed dose combinations, including start antihypertensive therapy are analyzed. Classification of combinations, advantages and limitations of some of them implementation are also presented. Significance of beta-blocker bisoprolol and thiazide diuretic hydrochlorothiazide fixed combination (Lodoz is shown in HT treatment.

Evaluation of antimicrobial activity of the stem bark of Cylicodiscus ...

African Journals Online (AJOL)

The greater and remarkable antimicrobial activity of the (EA) extract of CG was recorded with Staphylococcus aureus, Proteus vulgaris and Bacillus cereus T. These results provide a rationalization for the traditional use of this plant for the treatment of infections diseases. Keywords: Antimicrobial activity; Cylicodiscus ...

Testing methods for antimicrobial activity of TiO2 photocatalyst

Directory of Open Access Journals (Sweden)

Markov Siniša L.

2014-01-01

Full Text Available In recent years, a lot of commercial TiO2 photocatalyst products have been developed and extensively studied for prospective and safe antimicrobial application in daily life, medicine, laboratories, food and pharmaceutical industry, waste water treatments and in development of new self-cleaning and antimicrobial materials, surfaces and paints. This paper reviews the studies published worldwide on killing microorganisms, methods for testing the antimicrobial activity, light sources and intensities, as well as calculation methods usually used when evaluating the antimicrobial properties of the TiO2-based products. Additionally, some strengths and weaknesses of the available methods for testing the antimicrobial activity of TiO2 photocatalyst products have been pointed out.[Projekat Ministarstva nauke Republike Srbije, br. III45008

Saccharomyces boulardii viability and efficacy in horses with antimicrobial-induced diarrhoea.

Science.gov (United States)

Boyle, A G; Magdesian, K G; Durando, M M; Gallop, R; Sigdel, S

2013-02-02

Saccharomyces boulardii has been successfully used in the prevention and treatment of antimicrobial-associated diarrhoea in humans. We hypothesised that a viable, dried lyophilised preparation of S boulardii would survive in the gastrointestinal tract of horses with antimicrobial-associated enterocolitis, and significantly decrease the duration of diarrhoea. Twenty-one horses, over one year of age, with antimicrobial-associated diarrhoea of up to 72 hours duration, were consecutively randomised in a controlled prospective study. The treatment group received S boulardii (25 g, orally, every 12 hours) until the cessation of clinical signs. S boulardii was successfully cultured in 58.3 per cent of treatment horses on day 3. No statistically significant differences were found in days to return to normal faecal consistency; resolution of watery diarrhoea; return to normal heart rate, respiratory rate and temperature; resolution of leucopaenia; attitude improvement; appetite improvement; and survival at discharge. This is the first study to demonstrate survival of S boulardii in horses with gastrointestinal illness. Further study of the efficacy and safety of S boulardii in horses with antimicrobial-associated diarrhoea in a larger group is warranted.

Antimicrobial Properties of Mesenchymal Stem Cells: Therapeutic Potential for Cystic Fibrosis Infection, and Treatment

Directory of Open Access Journals (Sweden)

Morgan T. Sutton

2016-01-01

Full Text Available Cystic fibrosis (CF is a genetic disease in which the battle between pulmonary infection and inflammation becomes the major cause of morbidity and mortality. We have previously shown that human MSCs (hMSCs decrease inflammation and infection in the in vivo murine model of CF. The studies in this paper focus on the specificity of the hMSC antimicrobial effectiveness using Pseudomonas aeruginosa (gram negative bacteria and Staphylococcus aureus (gram positive bacteria. Our studies show that hMSCs secrete bioactive molecules which are antimicrobial in vitro against Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pneumonia, impacting the rate of bacterial growth and transition into colony forming units regardless of the pathogen. Further, we show that the hMSCs have the capacity to enhance antibiotic sensitivity, improving the capacity to kill bacteria. We present data which suggests that the antimicrobial effectiveness is associated with the capacity to slow bacterial growth and the ability of the hMSCs to secrete the antimicrobial peptide LL-37. Lastly, our studies demonstrate that the tissue origin of the hMSCs (bone marrow or adipose tissue derived, the presence of functional cystic fibrosis transmembrane conductance regulator (CFTR: human, Cftr: mouse activity, and response to effector cytokines can impact both hMSC phenotype and antimicrobial potency and efficacy. These studies demonstrate, the unique capacity of the hMSCs to manage different pathogens and the significance of their phenotype in both the antimicrobial and antibiotic enhancing activities.

Clinicopathological studies on three preoperative combined treatments for rectal cancer

International Nuclear Information System (INIS)

Yoshioka, Yuji; Ichikawa, Daisuke; Iizuka, Ryouji; Hagiwara, Akeo; Sawai, Kiyoshi; Yamaguchi, Toshiharu; Takahashi, Toshio

1995-01-01

To prevent postoperative local recurrence of rectal cancer, we treated patients using preoperative hyperthermia (5-6 times), irradiation (total 30 Gy) and 5-fluorouracil suppository (2,000-2,500 mg). The subjects were 31 patients given combined treatments and 28 patients given surgery alone. The results were as follows: Histologically, therapeutic effects were recognized in 80.6% of patients receiving combined treatments. The mean distance from the adventitia to the site of cancer infiltration was 6.54 mm in the combined treatments group and 3.35 mm in the surgery alone group. The difference between the two was significant (p<0.05). The rate of local recurrence in the combined treatments group was less than that in the surgery alone group. No systemic side effects nor severe complications were observed during hospitalization in the combined treatments group. The survival rate of the combined treatments group was higher than that of the surgery alone group. It was considered that combined preoperative treatments for rectal cancer were beneficial to survival and local control. (author)

Effects of pharmaceutical counselling on antimicrobial use in surgical wards: intervention study with historical control group.

Science.gov (United States)

Grill, Eva; Weber, Alexandra; Lohmann, Stefanie; Vetter-Kerkhoff, Cornelia; Strobl, Ralf; Jauch, Karl-Walter

2011-07-01

The objective of this study was to assess the impact of pharmaceutical consulting on the quality of antimicrobial use in a surgical hospital department in a prospective controlled intervention study. Patients receiving pharmaceutical intervention (intervention group, IG, n = 317) were compared with a historical control group (control group, CG, n = 321). During the control period, antimicrobial use was monitored without intervention. During the subsequent intervention period, a clinical pharmacist reviewed the prescriptions and gave advice on medication. Intervention reduced the length of antimicrobial courses (IG = 10 days, CG = 11 days, incidence rate ratio for i.v. versus o.p. = 0.88, 95% confidence interval 0.84 to 0.93) and shortened i.v. administration (IG = 8 days, CG = 10 days, hazard rate = 1.76 in favour of switch from i.v. to p.o., 95% confidence interval 1.23 to 2.52). Intervention also helped to avoid useless combination therapy and reduced total costs for antimicrobials. A clinical pharmacist who reviews prescriptions can promote an increase in efficiency, for example, by shortening the course of treatment. Counselling by ward-based clinical pharmacists was shown to be effective to streamline antimicrobial therapy in surgical units and to increase drug safety. Copyright © 2011 John Wiley & Sons, Ltd.

Evaluation of the synergistic potential of vancomycin combined with other antimicrobial agents against methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus spp strains

Directory of Open Access Journals (Sweden)

Lívia Viganor da Silva

2011-02-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA and coagulase-negative Staphylococcus spp (CNS are the most common pathogens that cause serious long term infections in patients. Despite the existence of new antimicrobial agents, such as linezolid, vancomycin (VAN remains the standard therapy for the treatment of infections caused by these multidrug-resistant strains. However, the use of VAN has been associated with a high frequency of therapeutic failures in some clinical scenarios, mainly with decreasing concentration of VAN. This work aims to evaluate the synergic potential of VAN plus sulfamethoxazole/trimethoprim (SXT, VAN plus rifampin (RIF and VAN plus imipenem (IPM in sub-minimum inhibitory concentrations against 22 clinical strains of MRSA and CNS. The checkerboard method showed synergism of VAN/RIF and VAN/SXT against two and three of the 22 strains, respectively. The combination of VAN with IPM showed synergistic effects against 21 out of 22 strains by the E-test method. Four strains were analyzed by the time-kill curve method and synergistic activity was observed with VAN/SXT, VAN/RIF and especially VAN/IPM in sub-inhibitory concentrations. It would be interesting to determine if synergy occurs in vivo. Evidence of in vivo synergy could lead to a reduction of the standard VAN dosage or treatment time.

Enrofloxacin and Macrolides Alone or in Combination with Rifampicin as Antimicrobial Treatment in a Bovine Model of Acute Chlamydia psittaci Infection

Science.gov (United States)

Prohl, Annette; Lohr, Markus; Ostermann, Carola; Liebler-Tenorio, Elisabeth; Berndt, Angela; Schroedl, Wieland; Rothe, Michael; Schubert, Evelyn; Sachse, Konrad; Reinhold, Petra

2015-01-01

Chlamydia psittaci is a zoonotic bacterium with a wide host range that can cause respiratory disease in humans and cattle. In the present study, effects of treatment with macrolides and quinolones applied alone or in combination with rifampicin were tested in a previously established bovine model of respiratory C. psittaci infection. Fifty animals were inoculated intrabronchially at the age of 6–8 weeks. Seven served as untreated controls, the others were assigned to seven treatment groups: (i) rifampicin, (ii) enrofloxacin, (iii) enrofloxacin + rifampicin, (iv) azithromycin, (v) azithromycin + rifampicin, (vi) erythromycin, and (vii) erythromycin + rifampicin. Treatment started 30 hours after inoculation and continued until 14 days after inoculation (dpi), when all animals were necropsied. The infection was successful in all animals and sufficient antibiotic levels were detected in blood plasma and tissue of the treated animals. Reisolation of the pathogen was achieved more often from untreated animals than from other groups. Nevertheless, pathogen detection by PCR was possible to the same extent in all animals and there were no significant differences between treated and untreated animals in terms of local (i.e. cell count and differentiation of BALF-cells) and systemic inflammation (i.e. white blood cells and concentration of acute phase protein LBP), clinical signs, and pathological findings at necropsy. Regardless of the reduced reisolation rate in treated animals, the treatment of experimentally induced respiratory C. psittaci infection with enrofloxacin, azithromycin or erythromycin alone or in combination with rifampicin was without obvious benefit for the host, since no significant differences in clinical and pathological findings or inflammatory parameters were detected and all animals recovered clinically within two weeks. PMID:25768665

Antimicrobial efficacy of granulysin-derived synthetic peptides in acne vulgaris.

Science.gov (United States)

Lim, Hee-Sun; Chun, Seung-Min; Soung, Min-Gyu; Kim, Jenny; Kim, Seong-Jin

2015-07-01

Antimicrobial peptides are considered as a potential alternative to antibiotic treatment in acne vulgaris because the development of a resistant strain of Propionibacterium acnes is problematic. Granulysin can be regarded as an ideal substance with which to treat acne because it has antimicrobial and anti-inflammatory effects. This study was performed to explore the effectiveness of granulysin-derived peptides (GDPs) in killing P. acnes in vitro under a standard microbiologic assay and to evaluate their potential use in a topical agent for the treatment of acne vulgaris. Twenty different peptides based on the known sequence of a GDP were synthesized and tested in vitro for antimicrobial activity. Thirty patients with facial acne vulgaris were instructed to apply a topical formulation containing synthetic GDP to acne lesions twice per day for 12 weeks. A newly synthesized peptide in which aspartic acid was substituted with arginine, and methionine was substituted with cysteine, showed the highest antimicrobial activity against P. acnes. Moreover, it was effective against both Gram-positive and Gram-negative bacteria in vitro. After treatment with the topical formulation containing 50 ppm of synthetic peptide for 12 weeks, a significant reduction in the number of pustules was observed, regardless of the increase in the number of comedones. In addition, a significant reduction in the clinical grade of acne based on the Korean Acne Grading System (KAGS) was evident. Synthesized GDP shows strong antimicrobial activity against P. acnes in vitro. The clinical improvement observed suggests a topical formulation containing the GDP has therapeutic potential for the improvement of inflammatory-type acne vulgaris by its antimicrobial activity. © 2015 The International Society of Dermatology.

Combined modality treatment with radiotherapy and chemotherapy

International Nuclear Information System (INIS)

Tannock, I.F.; Toronto Univ., ON

1989-01-01

The present paper discusses some of the methodological issues which can confound the interpretation of clinical trials of combined modality treatment. It reviews some of the larger randomized trials which have evaluated combined modality treatment in cancers of the head and neck, lung, gastrointestinal tract and bladder. It concludes that adequate trials have yet to be performed in many of thses sites, but that at present, evidence for long-term benefit from adjunctivechemotherapy is meagre. Finally, it suggests some possible mechanisms which might heve limited the benefit of chemotherapy when added to radiation treatment. (Author). 87 refs.; 4 figs.; 4 tabs

Antimicrobial Use Guidelines for Treatment of Urinary Tract Disease in Dogs and Cats: Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases

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J. Scott Weese

2011-01-01

Full Text Available Urinary tract disease is a common reason for use (and likely misuse, improper use, and overuse of antimicrobials in dogs and cats. There is a lack of comprehensive treatment guidelines such as those that are available for human medicine. Accordingly, guidelines for diagnosis and management of urinary tract infections were created by a Working Group of the International Society for Companion Animal Infectious Diseases. While objective data are currently limited, these guidelines provide information to assist in the diagnosis and management of upper and lower urinary tract infections in dogs and cats.

Mycobacterial r32-kDa antigen-specific T-cell responses correlate with successful treatment and a heightened anti-microbial response in human leprosy patients.

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Neela, Venkata Sanjeev Kumar; Devalraju, Kamakshi Prudhula; Pydi, Satya Sudheer; Sunder, Sharada Ramaseri; Adiraju, Kameswara Rao; Singh, Surya Satyanarayana; Anandaraj, M P J S; Valluri, Vijaya Lakshmi

2016-09-01

Immunological characterization of mycobacterial peptides may help not only in the preparation of a vaccine for leprosy but also in developing in vitro T-cell assays that could perhaps be used as an in vitro correlate for treatment outcome. The main goal of this study was to evaluate the use of Mycobacterium bovis recombinant 32-kDa protein (r32-kDa) antigen-stimulated T-cell assay as a surrogate marker for treatment outcome and monitor vitamin D receptor (VDR)-mediated anti-microbial responses during multidrug therapy (MDT) in leprosy. Newly diagnosed tuberculoid and lepromatous leprosy patients were enrolled and followed up during their course of MDT at 6 and 12 months. IFN-γ, IL-10, IL-17 and IL-23 levels in culture supernatants and expression of VDR, TLR2, LL37 and DEFB in r32-kDa-stimulated PBMCs were measured. Controls comprised household contacts (HHCs) and healthy endemic subjects (HCs). Significant differences were observed in the levels of IFN-γ, IL-17, IL-23, VDR and anti-microbial peptides LL37 and DEFB after treatment and when compared with that of HHCs and HCs, respectively. These findings suggest that responses to r32-kDa antigen reflect an improved immunological and anti-microbial response in leprosy patients during therapy, thereby indicating its potential use as an immune correlate in the treatment of leprosy patients. © The Japanese Society for Immunology. 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Increased Risk for ESBL-Producing Bacteria from Co-administration of Loperamide and Antimicrobial Drugs for Travelers' Diarrhea.

Science.gov (United States)

Kantele, Anu; Mero, Sointu; Kirveskari, Juha; Lääveri, Tinja

2016-01-01

Antimicrobial drug treatment of travelers' diarrhea is known to increase the risk for colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae. Among 288 travelers with travelers' diarrhea, the colonization rate without medications was 21%. For treatment with loperamide only, the rate was 20%; with antimicrobial drugs alone, 40%; and with loperamide and antimicrobial drugs, 71%.

Synthetic biology platform technologies for antimicrobial applications.

Science.gov (United States)

Braff, Dana; Shis, David; Collins, James J

2016-10-01

The growing prevalence of antibiotic resistance calls for new approaches in the development of antimicrobial therapeutics. Likewise, improved diagnostic measures are essential in guiding the application of targeted therapies and preventing the evolution of therapeutic resistance. Discovery platforms are also needed to form new treatment strategies and identify novel antimicrobial agents. By applying engineering principles to molecular biology, synthetic biologists have developed platforms that improve upon, supplement, and will perhaps supplant traditional broad-spectrum antibiotics. Efforts in engineering bacteriophages and synthetic probiotics demonstrate targeted antimicrobial approaches that can be fine-tuned using synthetic biology-derived principles. Further, the development of paper-based, cell-free expression systems holds promise in promoting the clinical translation of molecular biology tools for diagnostic purposes. In this review, we highlight emerging synthetic biology platform technologies that are geared toward the generation of new antimicrobial therapies, diagnostics, and discovery channels. Copyright © 2016 Elsevier B.V. All rights reserved.

Protein-only, antimicrobial peptide-containing recombinant nanoparticles with inherent built-in antibacterial activity.

Science.gov (United States)

Serna, Naroa; Sánchez-García, Laura; Sánchez-Chardi, Alejandro; Unzueta, Ugutz; Roldán, Mónica; Mangues, Ramón; Vázquez, Esther; Villaverde, Antonio

2017-09-15

The emergence of bacterial antibiotic resistances is a serious concern in human and animal health. In this context, naturally occurring cationic antimicrobial peptides (AMPs) might play a main role in a next generation of drugs against bacterial infections. Taking an innovative approach to design self-organizing functional proteins, we have generated here protein-only nanoparticles with intrinsic AMP microbicide activity. Using a recombinant version of the GWH1 antimicrobial peptide as building block, these materials show a wide antibacterial activity spectrum in absence of detectable toxicity on mammalian cells. The GWH1-based nanoparticles combine clinically appealing properties of nanoscale materials with full biocompatibility, structural and functional plasticity and biological efficacy exhibited by proteins. Because of the largely implemented biological fabrication of recombinant protein drugs, the protein-based platform presented here represents a novel and scalable strategy in antimicrobial drug design, that by solving some of the limitations of AMPs offers a promising alternative to conventional antibiotics. The low molecular weight antimicrobial peptide GWH1 has been engineered to oligomerize as self-assembling protein-only nanoparticles of around 50nm. In this form, the peptide exhibits potent and broad antibacterial activities against both Gram-positive and Gram-negative bacteria, without any harmful effect over mammalian cells. As a solid proof-of-concept, this finding strongly supports the design and biofabrication of nanoscale antimicrobial materials with in-built functionalities. The protein-based homogeneous composition offer advantages over alternative materials explored as antimicrobial agents, regarding biocompatibility, biodegradability and environmental suitability. Beyond the described prototype, this transversal engineering concept has wide applicability in the design of novel nanomedicines for advanced treatments of bacterial infections

Synthesis, spectroscopic and antimicrobial properties of Co(II), Ni (II ...

African Journals Online (AJOL)

The objective of this study is to investigate the antimicrobial activity of novel Schiff base metal complexes. The resistance of micro-organisms to classical antimicrobial compounds poses a challenge to effective management and treatment of some diseases. In line with this, copper (II), nickel (II) and cobalt (II) complexes of ...

Spectrum of antimicrobial activity associated with ionic colloidal silver.

Science.gov (United States)

Morrill, Kira; May, Kathleen; Leek, Daniel; Langland, Nicole; Jeane, La Deana; Ventura, Jose; Skubisz, Corey; Scherer, Sean; Lopez, Eric; Crocker, Ephraim; Peters, Rachel; Oertle, John; Nguyen, Krystine; Just, Scott; Orian, Michael; Humphrey, Meaghan; Payne, David; Jacobs, Bertram; Waters, Robert; Langland, Jeffrey

2013-03-01

Silver has historically and extensively been used as a broad-spectrum antimicrobial agent. However, the Food and Drug Administration currently does not recognize colloidal silver as a safe and effective antimicrobial agent. The goal of this study was to further evaluate the antimicrobial efficacy of colloidal silver. Several strains of bacteria, fungi, and viruses were grown under multicycle growth conditions in the presence or absence of ionic colloidal silver in order to assess the antimicrobial activity. For bacteria grown under aerobic or anaerobic conditions, significant growth inhibition was observed, although multiple treatments were typically required. For fungal cultures, the effects of ionic colloidal silver varied significantly between different genera. No viral growth inhibition was observed with any strains tested. The study data support ionic colloidal silver as a broad-spectrum antimicrobial agent against aerobic and anaerobic bacteria, while having a more limited and specific spectrum of activity against fungi.

Monitoring of antimicrobial resistance among food animals: Principles and limitations

DEFF Research Database (Denmark)

Aarestrup, Frank Møller

2004-01-01

Large amounts of antimicrobial agents are in the production of food animals used for therapy and prophylactics of bacterial infections and in feed to promote growth. The use of antimicrobial agents causes problems in the therapy of infections through the selection for resistance among bacteria...... pathogenic for animals or humans. Current knowledge regarding the occurrence of antimicrobial resistance in food animals, the quantitative impact of the use of different antimicrobial agents on selection for resistance and the most appropriate treatment regimes to limit the development of resistance......, there are major differences between programmes designed to detect changes in a national population, individual herds or groups of animals. In addition, programmes have to be designed differently according to whether the aim is to determine changes in resistance for all antimicrobial agents or only...

A new anti-microbial combination prolongs the latency period, reduces acute histologic chorioamnionitis as well as funisitis, and improves neonatal outcomes in preterm PROM.

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Lee, JoonHo; Romero, Roberto; Kim, Sun Min; Chaemsaithong, Piya; Park, Chan-Wook; Park, Joong Shin; Jun, Jong Kwan; Yoon, Bo Hyun

2016-03-01

Antibiotic administration is a standard practice in preterm premature rupture of membranes (PROM). Specific anti-microbial agents often include ampicillin and/or erythromycin. Anaerobes and genital mycoplasmas are frequently involved in preterm PROM, but are not adequately covered by antibiotics routinely used in clinical practice. Our objective was to compare outcomes of PROM treated with standard antibiotic administration versus a new combination more effective against these bacteria. A retrospective study compared perinatal outcomes in 314 patients with PROM 23 ng/mL). (1) Patients treated with regimen 2 had a longer median antibiotic-to-delivery interval than those with regimen 1 [median (interquartile range) 23 d (10-51 d) versus 12 d (5-52 d), p acute histologic chorioamnionitis (50.5% versus 66.7%, p hemorrhage (IVH) and cerebral palsy (CP) were significantly lower in patients allocated to regimen 2 than regimen 1 (IVH: 2.1% versus 19.0%, p acute histologic chorioamnionitis/funisitis, and improved neonatal outcomes in patients with preterm PROM. These findings suggest that the combination of anti-microbial agents (ceftriaxone, clarithromycin, and metronidazole) may improve perinatal outcome in preterm PROM.

Susceptibility of Pediococcus isolates to antimicrobial compounds in relation to hop-resistance and beer-spoilage

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Ziola Barry

2009-09-01

Full Text Available Abstract Background Though important in the context of food microbiology and as potential pathogens in immuno-compromised humans, bacterial isolates belonging to the genus Pediococcus are best known for their association with contamination of ethanol fermentation processes (beer, wine, or fuel ethanol. Use of antimicrobial compounds (e.g., hop-compounds, Penicillin by some industries to combat Pediococcus contaminants is long-standing, yet knowledge about the resistance of pediococci to antimicrobial agents is minimal. Here we examined Pediococcus isolates to determine whether antibiotic resistance is associated with resistance to hops, presence of genes known to correlate with beer spoilage, or with ability to grow in beer. Results Lactic acid bacteria susceptibility test broth medium (LSM used in combination with commercially available GPN3F antimicrobial susceptibility plates was an effective method for assessing antimicrobial susceptibility of Pediococcus isolates. We report the finding of Vancomycin-susceptible Pediococcus isolates from four species. Interestingly, we found that hop-resistant, beer-spoilage, and beer-spoilage gene-harbouring isolates had a tendency to be more susceptible, rather than more resistant, to antimicrobial compounds. Conclusion Our findings indicate that the mechanisms involved in conferring hop-resistance or ability to spoil beer by Pediococcus isolates are not associated with resistance to antibiotics commonly used for treatment of human infections. Also, Vancomycin-resistance was found to be isolate-specific and not intrinsic to the genus as previously believed.

Patterns Of Antimicrobial Use For Respiratory Tract Infections In Elderly Patients

International Nuclear Information System (INIS)

Taha, H.M.; Rasheedy, D.; Mahmoud, A.H.

2013-01-01

Background: Elderly patients are prone to respiratory tract infections (RTIs) both; acute bronchitis and pneumonia. A large proportion of the antibiotics prescribed are unlikely to provide clinical benefit to patients. There is an increased need to decrease excess antibiotic use in elderly to minimize antibiotic resistance. Objective: To describe patterns of antimicrobial use for respiratory tract infections (RTIs) among elderly Patients and methods: A cross sectional study was conducted on one hundred elderly patients, aged > 60 years, both males and females to describe patterns of antimicrobial use for respiratory tract infections (RTIs) among elderly patients. RTIs, categorized as acute bronchitis, and pneumonia, were studied for appropriateness of antimicrobial use, type of antibiotics used, and factors associated with their use. We rated antibiotic use as appropriate (when an effective drug was used), inappropriate (when a more effective drug was indicated), or unjustified (when use of any antimicrobial was not indicated). Results: Of 100 patients with RTI, overall treatment was appropriate in 79% of episodes, inappropriate in 9%, and unjustified in 12%. For acute bronchitis, treatment was appropriate in 85% and unjustified in 15% of cases. For pneumonia, treatment was appropriate in 55% of episodes. Among the most commonly used antimicrobials, B.Lactam + macrolides their use were unjustified in 41% of cases. There were statistical significant differences in the patterns of antibiotic use when stratified by age, gender, and co- morbid conditions including chronic obstructive pulmonary disease. Conclusion: Antimicrobials are unjustifiably used for 12% of RTIs and 15% of cases of acute bronchitis, thus suggesting a need for programs to improve antibiotic prescribing at hospitals.

Antimicrobial synergy between carprofen and doxycycline against methicillin-resistant Staphylococcus pseudintermedius ST71.

Science.gov (United States)

Brochmann, Rikke Prejh; Helmfrid, Alexandra; Jana, Bimal; Magnowska, Zofia; Guardabassi, Luca

2016-06-24

New therapeutic strategies are needed to face the rapid spread of multidrug-resistant staphylococci in veterinary medicine. The objective of this study was to identify synergies between antimicrobial and non-antimicrobial drugs commonly used in companion animals as a possible strategy to restore antimicrobial susceptibility in methicillin-resistant Staphylococcus pseudintermedius (MRSP). A total of 216 antimicrobial/non-antimicrobial drug combinations were screened by disk diffusion using a clinical MRSP sequence type (ST) 71 strain resistant to all six antimicrobials tested (ampicillin, ciprofloxacin, clindamycin, doxycycline, oxacillin and trimethoprim/sulfamethoxazole). The most promising drug combination (doxycycline-carprofen) was further assessed by checkerboard testing extended to four additional MRSP strains belonging to ST71 or ST68, and by growth inhibition experiments. Seven non-antimicrobial drugs (bromhexine, acepromazine, amitriptyline, clomipramine, carprofen, fluoxetine and ketoconazole) displayed minimum inhibitory concentrations (MICs) ranging between 32 and >4096 mg/L, and enhanced antimicrobial activity of one or more antimicrobials. Secondary screening by checkerboard assay revealed a synergistic antimicrobial effect between carprofen and doxycycline, with the sum of the fractional inhibitory concentration indexes (ΣFICI) ranging between 0.3 and 0.5 depending on drug concentration. Checkerboard testing of multiple MRSP strains revealed a clear association between synergy and carriage of tetK, which is a typical feature of MRSP ST71. An increased growth inhibition was observed when MRSP ST71 cells in exponential phase were exposed to 0.5/32 mg/L of doxycycline/carprofen compared to individual drug exposure. Carprofen restores in vitro susceptibility to doxycycline in S. pseudintermedius strains carrying tetK such as MRSP ST71. Further research is warranted to elucidate the molecular mechanism behind the identified synergy and its linkage to

Antimicrobial efficacy of Acacia nilotica, Murraya koenigii (L.) Sprengel, Eucalyptus hybrid, Psidium guajava extracts and their combination on Streptococcus mutans and Lactobacillus acidophilus.

Science.gov (United States)

Chandra Shekar, B R; Nagarajappa, Ramesh; Jain, Richa; Singh, Rupal; Thakur, Rupesh; Shekar, Suma

2016-01-01

The aim of this in vitro study was to assess antimicrobial efficacy of Acacia nilotica, Murraya koenigii (L.) Sprengel, Eucalyptus hybrid, Psidium guajava extracts, and their combination on Streptococcus mutans and Lactobacillus acidophilus. The branches of four plants were collected, identified, and authenticated by a taxonomist. The plants were rinsed in water, healthy leaves were separated and shade dried over a period of 3-4 weeks. Soxhlet apparatus using ethanol was employed for extraction procedure. The combinations of plant extracts were prepared by mixing equal quantities of 10% solutions of each of these extracts. 0.2% chlorhexidine and dimethyl sulfoxide were used as positive and negative controls, respectively. The antimicrobial efficacy testing was done using agar well-diffusion method under anaerobic conditions. The mean diameter of inhibition zone was computed and compared between different categories using one-way analysis of variance and Tukey's post-hoc test. A qualitative assay was carried out to identify the various phytochemical constituents in the plants. The data was assessed by SPSS version 20. The statistical significance was fixed at 0.05. All the plants extracts and their combinations inhibited S. mutans and L. acidophilus. However, the quadruple combination of A. nilotica + M. koenigii (L.) Sprengel + Eucalyptus hybrid + P. guajava produced the maximum inhibition zone (23.5 ± 2.2 mm) against S. mutans. Although, 0.2% chlorhexidine produced the highest inhibition zone against L. acidophilus (18.8 ± 1.2 mm), A. nilotica extract produced maximum inhibition among the various plant extracts and their combinations (14.1 ± 1.8 mm). All the individual plant extracts and their combinations were effective against S. mutans and L. acidophilus. These could be tried as herbal alternates to chlorhexidine. However, these in vitro results have to be further evaluated for any toxicity of the polyherbal combinations in animal models and effectiveness

Surface-Adaptive, Antimicrobially Loaded, Micellar Nanocarriers with Enhanced Penetration and Killing Efficiency in Staphylococcal Biofilms

NARCIS (Netherlands)

Liu, Yong; Busscher, Henk J; Zhao, Bingran; Li, Yuanfeng; Zhang, Zhenkun; van der Mei, Henny C; Ren, Yijin; Shi, Linqi

Biofilms cause persistent bacterial infections and are extremely recalcitrant to antimicrobials, due in part to reduced penetration of antimicrobials into biofilms that allows bacteria residing in the depth of a biofilm to survive antimicrobial treatment. Here, we describe the preparation of

Cellulose nanocrystals from Actinidia deliciosa pruning residues combined with carvacrol in PVA_CH films with antioxidant/antimicrobial properties for packaging applications.

Science.gov (United States)

Luzi, Francesca; Fortunati, Elena; Giovanale, Geremia; Mazzaglia, Angelo; Torre, Luigi; Balestra, Giorgio Mariano

2017-11-01

Kiwi Actinidia deliciosa pruning residues were here used for the first time as precursors for the extraction of high performing cellulose nanocrystals (CNC) by applying a bleaching treatment followed by an acidic hydrolysis. The resultant cellulosic nanostructures, obtained by an optimize extraction procedure (0.7% wt/v two times of sodium chlorite NaClO 2 ) followed by an hydrolysis step, were then used as reinforcements phases in poly(vinyl alcohol) (PVA) blended with natural chitosan (CH) based films and also combined, for the first time, with carvacrol used here as active agent. Morphological and optical characteristics, mechanical response, thermal and migration properties, moisture content and antioxidant and antimicrobial assays were conducted. The morphological, optical and colorimetric results underlined that no particular alterations were induced on the transparency and color of PVA and PVA_CH blend by the presence of CNC and carvacrol, while they were able to modulate the mechanical responses, to induce antioxidant activities maintaining the migration levels below the permitted limits and suggesting the possible application in industrial sectors. Finally, inhibitions on bacterial development were detected for multifunctional systems, suggesting their protective function against microorganisms contamination. Copyright © 2017 Elsevier B.V. All rights reserved.

Synergistic antimicrobial therapy using nanoparticles and antibiotics for the treatment of multidrug-resistant bacterial infection

Science.gov (United States)

Gupta, Akash; Saleh, Neveen M.; Das, Riddha; Landis, Ryan F.; Bigdeli, Arafeh; Motamedchaboki, Khatereh; Rosa Campos, Alexandre; Pomeroy, Kenneth; Mahmoudi, Morteza; Rotello, Vincent M.

2017-06-01

Infections caused by multidrug-resistant (MDR) bacteria pose a serious global burden of mortality, causing thousands of deaths each year. Antibiotic treatment of resistant infections further contributes to the rapidly increasing number of antibiotic-resistant species and strains. Synthetic macromolecules such as nanoparticles (NPs) exhibit broad-spectrum activity against MDR species, however lack of specificity towards bacteria relative to their mammalian hosts limits their widespread therapeutic application. Here, we demonstrate synergistic antimicrobial therapy using hydrophobically functionalized NPs and fluoroquinolone antibiotics for treatment of MDR bacterial strains. An 8-16-fold decrease in antibiotic dosage is achieved in presence of engineered NPs to combat MDR strains. This strategy demonstrates the potential of using NPs to ‘revive’ antibiotics that have been rendered ineffective due to the development of resistance by pathogenic bacteria.

Antimicrobial Activity and Stability of Short and Long Based Arachnid Synthetic Peptides in the Presence of Commercial Antibiotics.

Science.gov (United States)

Arenas, Ivan; Villegas, Elba; Walls, Oliver; Barrios, Humberto; Rodríguez, Ramon; Corzo, Gerardo

2016-02-17

Four antimicrobial peptides (AMPs) named Pin2[G], Pin2[14], P18K and FA1 were chemically synthesized and purified. The four peptides were evaluated in the presence of eight commercial antibiotics against four microorganisms of medical importance: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. The commercial antibiotics used were amoxicillin, azithromycin, ceftriaxone, gentamicin, levofloxacin, sulfamethoxazole, trimethoprim and vancomycin. The best AMP against P. aeruginosa was the peptide FA1, and the best AMP against S. aureus was Pin2[G]. Both FA1 and Pin2[G] were efficient against E. coli, but they were not effective against K. pneumoniae. As K. pneumoniae was resistant to most of the commercial antibiotics, combinations of the AMPs FA1 and Pin2[G] were prepared with these antibiotics. According to the fractional inhibitory concentration (FIC) index, the best antimicrobial combinations were obtained with concomitant applications of mixtures of FA1 with levofloxacin and sulfamethoxazole. However, combinations of FA1 or Pin2[G] with other antibiotics showed that total inhibitory effect of the combinations were greater than the sum of the individual effects of either the antimicrobial peptide or the antibiotic. We also evaluated the stability of the AMPs. The AMP Pin2[G] manifested the best performance in saline buffer, in supernatants of bacterial growth and in human blood plasma. Nevertheless, all AMPs were cleaved using endoproteolytic enzymes. These data show advantages and disadvantages of AMPs for potential clinical treatments of bacterial infections, using them in conjunction with commercial antibiotics.

Antimicrobial Activity and Stability of Short and Long Based Arachnid Synthetic Peptides in the Presence of Commercial Antibiotics

Directory of Open Access Journals (Sweden)

Ivan Arenas

2016-02-01

Full Text Available Four antimicrobial peptides (AMPs named Pin2[G], Pin2[14], P18K and FA1 were chemically synthesized and purified. The four peptides were evaluated in the presence of eight commercial antibiotics against four microorganisms of medical importance: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. The commercial antibiotics used were amoxicillin, azithromycin, ceftriaxone, gentamicin, levofloxacin, sulfamethoxazole, trimethoprim and vancomycin. The best AMP against P. aeruginosa was the peptide FA1, and the best AMP against S. aureus was Pin2[G]. Both FA1 and Pin2[G] were efficient against E. coli, but they were not effective against K. pneumoniae. As K. pneumoniae was resistant to most of the commercial antibiotics, combinations of the AMPs FA1 and Pin2[G] were prepared with these antibiotics. According to the fractional inhibitory concentration (FIC index, the best antimicrobial combinations were obtained with concomitant applications of mixtures of FA1 with levofloxacin and sulfamethoxazole. However, combinations of FA1 or Pin2[G] with other antibiotics showed that total inhibitory effect of the combinations were greater than the sum of the individual effects of either the antimicrobial peptide or the antibiotic. We also evaluated the stability of the AMPs. The AMP Pin2[G] manifested the best performance in saline buffer, in supernatants of bacterial growth and in human blood plasma. Nevertheless, all AMPs were cleaved using endoproteolytic enzymes. These data show advantages and disadvantages of AMPs for potential clinical treatments of bacterial infections, using them in conjunction with commercial antibiotics.

Place of Colistin-Rifampicin Association in the Treatment of Multidrug-Resistant Acinetobacter Baumannii Meningitis: A Case Study

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Dahraoui Souhail

2016-01-01

Full Text Available Treatment of Acinetobacter baumannii meningitis is an important challenge due to the accumulation of resistance of this bacteria and low meningeal diffusion of several antimicrobial requiring use of an antimicrobial effective combination to eradicate these species. We report a case of Acinetobacter baumannii multidrug-resistant nosocomial meningitis which was successfully treated with intravenous and intrathecal colistin associated with rifampicin.

Efficacy of antimicrobial photodynamic therapy as an adjuvant in periodontal treatment in Down syndrome patients.

Science.gov (United States)

Martins, Fabiana; Simões, Alyne; Oliveira, Marcio; Luiz, Ana Claudia; Gallottini, Marina; Pannuti, Claudio

2016-12-01

Down syndrome (DS) has characteristics that include mental retardation, a characteristic phenotype, congenital heart defects, immune disorders, and increased risk of periodontal disease (PD). Antimicrobial photodynamic therapy (aPDT) is the combined use of photosensitizers associated with low-level laser (LLL) and oxygen, leading to singlet oxygen formation, which contributes to the antibacterial activity of the phagocytes, killing bacteria. The objective of this study was to evaluate the efficacy of aPDT as an adjuvant to conventional periodontal treatment of PD in DS patients. A double-blinded, controlled, randomized, split-mouth study was conducted. A total of 13 DS subjects who were 18 years or older and who presented at least one tooth in each quadrant of the mouth with probing pocket depth (PPD) equal to or greater than 5 mm were included. The patients were evaluated at three different times: at the baseline, PPD were obtained. After 1 week, conventional scaling and root planing (SRP) was performed, and two randomly selected quadrants also received aPDT. One month after SRP, all the patients were reevaluated. Periodontal conditions were improved among all the participants. The PDT-with-SRP group presented a nonsignificant reduction in PPD (mean = 1.27 mm, median = 1.17 mm) relative to that of the SRP group (mean = 1.00 mm, median = 0.95 mm). Changes over time were compared using the Wilcoxon test. A significant reduction in median PPD was observed in both groups (p = 0.001). Both types of periodontal treatment, with and without PDT, were similarly effective and were associated with good clinical response.

Adjunctive Application of Antimicrobial Photodynamic Therapy in Nonsurgical Periodontal Treatment: A Review of Literature

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Takeshi Kikuchi

2015-10-01

Full Text Available Periodontal disease is caused by dental plaque biofilms, and the removal of these biofilms from the root surface of teeth plays a central part in its treatment. The conventional treatment for periodontal disease fails to remove periodontal infection in a subset of cases, such as those with complicated root morphology. Adjunctive antimicrobial photodynamic therapy (aPDT has been proposed as an additional treatment for this infectious disease. Many periodontal pathogenic bacteria are susceptible to low-power lasers in the presence of dyes, such as methylene blue, toluidine blue O, malachite green, and indocyanine green. aPDT uses these light-activated photosensitizer that is incorporated selectively by bacteria and absorbs a low-power laser/light with an appropriate wavelength to induce singlet oxygen and free radicals, which are toxic to bacteria. While this technique has been evaluated by many clinical studies, some systematic reviews and meta-analyses have reported controversial results about the benefits of aPDT for periodontal treatment. In the light of these previous reports, the aim of this review is to provide comprehensive information about aPDT and help extend knowledge of advanced laser therapy.

Use of antimicrobial growth promoters in food animals and Enterococcus faecium resistance to therapeutic antimicrobial drugs in Europe

DEFF Research Database (Denmark)

Wegener, Henrik Caspar; Aarestrup, Frank Møller; Jensen, Lars Bogø

1999-01-01

on the Tn1546 transposon. Furthermore, glycopeptide-resistant strains, as well as resistance determinants, can be transmitted from animals to humans. Two antimicrobial classes expected to provide the future therapeutic options for treatment of infections with vancomycin-resistant enterococci have analogues......Supplementing animal feed with antimicrobial agents to enhance growth has been common practice for more than 30 years and is estimated to constitute more than half the total antimicrobial use worldwide. The potential public health consequences of this use have been debated; however, until recently......, clear evidence of a health risk was not available. Accumulating evidence now indicates that the use of the glycopeptide avoparcin as a growth promoter has created in food animals a major reservoir of Enterococcus faecium, which contains the high level glycopeptide resistance determinant vanA, located...

Antimicrobial agents of plant origin for the treatment of phlogistic-infectious diseases of the lower female genital tract

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Francesco Gon

2012-12-01

Full Text Available The phlogistic-infectious diseases of the lower female genital tract are one of the most widespread obstetricgynecologic issues, due to treatment failures that cause frequent relapses and to the adverse effects of some commonly used drugs.The most common vaginal syndromes are due to uncontrolled growth of bacteria or fungi which replace the normal vaginal flora, causing phlogistic and infectious based diseases. These infections are treated with anti-inflammatory and antibiotic therapy; however, the emergence of resistant strains and the ability of many microorganisms to grow inside biofilms severely reduce the repertoire of useful agents.Thus, in the last years increasing interest has been focused toward compounds of plant origin with anti-microbial properties. In the present work, we studied the antimicrobial activity of fractions obtained from endemic plants of Sardinia towards microorganisms that frequently are involved in vaginal infectious diseases: Streptococcus agalactiae, Gardnerella vaginalis and Candida albicans.

Prevalence, Risk Factors and Antimicrobial Resistance of ...

African Journals Online (AJOL)

Mubeen

Background: Asymptomatic bacteriuria (ABU) in antenatal women is microbiological diagnosis ... 287 asymptomatic pregnant women who attended the antenatal clinic at a tertiary care ... that antimicrobial treatment of ABU during pregnancy.

Invitro antimicrobial susceptibility pattern of bacterial isolates from ...

African Journals Online (AJOL)

... of bacterial isolates from wound infections in university of Ilorin Teaching Hospital. ... The Fluoroquino lones are the favoured antimicrobial agents nowadays, ... In our environment however, a combination of Cloxacillin and Gentamicin is an ...

Therapeutic Potential of Plants as Anti-Microbials for Drug Discovery

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Ramar Perumal Samy

2010-01-01

Full Text Available The uses of traditional medicinal plants for primary health care have steadily increased worldwide in recent years. Scientists are in search of new phytochemicals that could be developed as useful anti-microbials for treatment of infectious diseases. Currently, out of 80% of pharmaceuticals derived from plants, very few are now being used as anti-microbials. Plants are rich in a wide variety of secondary metabolites that have found anti-microbial properties. This review highlights the current status of traditional medicine, its contribution to modern medicine, recent trends in the evaluation of anti-microbials with a special emphasis upon some tribal medicine, in vitro and in vivo experimental design for screening, and therapeutic efficacy in safety and human clinical trails for commercial outlet. Many of these commercially available compounds are crude preparations administered without performing human clinical trials. Recent methods are useful to standardize the extraction for scientific investigation of new phytochemicals and anti-microbials of traditionally used plants. It is concluded that once the local ethnomedical preparations of traditional sources are scientifically evaluated before dispensing they should replace existing drugs commonly used for the therapeutic treatment of infection. This method should be put into practice for future investigations in the field of ethnopharmacology, phytochemistry, ethnobotany and other biological fields for drug discovery.

Impact of ertapenem on antimicrobial resistance in a sentinel group of Gram-negative bacilli: a 6 year antimicrobial resistance surveillance study.

Science.gov (United States)

Rodriguez-Osorio, Carlos A; Sanchez-Martinez, Cesar O; Araujo-Melendez, Javier; Criollo, Elia; Macias-Hernandez, Alejandro E; Ponce-de-Leon, Alfredo; Ponce-de-Leon, Sergio; Sifuentes-Osornio, Jose

2015-03-01

To determine the association between ertapenem and resistance of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii-calcoaceticus complex to different antimicrobials while adjusting for relevant hospital factors. This was a retrospective time-series study conducted at a tertiary care centre from September 2002 to August 2008. The specific impact of ertapenem on the resistance of these Gram-negative bacilli (GNB) was assessed by multiple linear regression analysis, adjusting for the average length of stay, rate of hospital-acquired infections and use of 10 other antimicrobials, including type 2 carbapenems. Unadjusted analyses revealed significant increases over the duration of the study in the number of GNB resistant to meropenem/imipenem among 1000 isolates each of E. coli (0.46 ± 0.22, P  0.05) with changes in resistance for any pathogen/antimicrobial combination. After controlling for confounders, ertapenem was not associated with changes in resistance in a group of sentinel GNB, although significant variations in resistance to different antimicrobials were observed in the unadjusted analyses. These results emphasize the importance of implementation of local resistance surveillance platforms and stewardship programmes to combat the global emergence and spread of antimicrobial resistance. © The Author 2014. 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.

Antimicrobial stewardship in a Gastroenterology Department: Impact on antimicrobial consumption, antimicrobial resistance and clinical outcome.

Science.gov (United States)

Bedini, Andrea; De Maria, Nicola; Del Buono, Mariagrazia; Bianchini, Marcello; Mancini, Mauro; Binda, Cecilia; Brasacchio, Andrea; Orlando, Gabriella; Franceschini, Erica; Meschiari, Marianna; Sartini, Alessandro; Zona, Stefano; Paioli, Serena; Villa, Erica; Gyssens, Inge C; Mussini, Cristina

2016-10-01

A major cause of the increase in antimicrobial resistance is the inappropriate use of antimicrobials. To evaluate the impact on antimicrobial consumption and clinical outcome of an antimicrobial stewardship program in an Italian Gastroenterology Department. Between October 2014 and September 2015 (period B), a specialist in infectious diseases (ID) controlled all antimicrobial prescriptions and decided about the therapy in agreement with gastroenterologists. The defined daily doses of antimicrobials (DDDs), incidence of MDR-infections, mean length of stay and overall in-hospital mortality rate were compared with those of the same period in the previous 12-months (period A). During period B, the ID specialist performed 304 consultations: antimicrobials were continued in 44.4% of the cases, discontinued in 13.8%, not recommended in 12.1%, de-escalated 9.9%, escalated in 7.9%, and started in 4.0%. Comparing the 2 periods, we observed a decreased of antibiotics consumption (from 109.81 to 78.45 DDDs/100 patient-days, p=0.0005), antifungals (from 41.28 to 24.75 DDDs/100pd, p=0.0004), carbapenems (from 15.99 to 6.80 DDDsx100pd, p=0.0032), quinolones (from 35.79 to 17.82 DDDsx100pd, p=0.0079). No differences were observed in incidence of MDR-infections, length of hospital stay (LOS), and mortality rate. ASP program had a positive impact on reducing the consumption of antimicrobials, without an increase in LOS and mortality. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Synergistic Efficacy of Aedes aegypti Antimicrobial Peptide Cecropin A2 and Tetracycline against Pseudomonas aeruginosa

Science.gov (United States)

Zheng, Zhaojun; Tharmalingam, Nagendran; Liu, Qingzhong; Kim, Wooseong; Fuchs, Beth Burgwyn; Zhang, Rijun; Vilcinskas, Andreas

2017-01-01

ABSTRACT The increasing prevalence of antibiotic resistance has created an urgent need for alternative drugs with new mechanisms of action. Antimicrobial peptides (AMPs) are promising candidates that could address the spread of multidrug-resistant bacteria, either alone or in combination with conventional antibiotics. We studied the antimicrobial efficacy and bactericidal mechanism of cecropin A2, a 36-residue α-helical cationic peptide derived from Aedes aegypti cecropin A, focusing on the common pathogen Pseudomonas aeruginosa. The peptide showed little hemolytic activity and toxicity toward mammalian cells, and the MICs against most clinical P. aeruginosa isolates were 32 to 64 μg/ml, and its MICs versus other Gram-negative bacteria were 2 to 32 μg/ml. Importantly, cecropin A2 demonstrated synergistic activity against P. aeruginosa when combined with tetracycline, reducing the MICs of both agents by 8-fold. The combination was also effective in vivo in the P. aeruginosa/Galleria mellonella model (P < 0.001). We found that cecropin A2 bound to P. aeruginosa lipopolysaccharides, permeabilized the membrane, and interacted with the bacterial genomic DNA, thus facilitating the translocation of tetracycline into the cytoplasm. In summary, the combination of cecropin A2 and tetracycline demonstrated synergistic antibacterial activity against P. aeruginosa in vitro and in vivo, offering an alternative approach for the treatment of P. aeruginosa infections. PMID:28483966

Sucralose Increases Antimicrobial Resistance and Stimulates Recovery of Escherichia coli Mutants.

Science.gov (United States)

Qu, Yilin; Li, Rongyan; Jiang, Mingshan; Wang, Xiuhong

2017-07-01

Because of heavy use of antimicrobials, antimicrobial resistance in bacteria has become of great concern. The effect of some widely used food additives such as sucralose on bacteria in the gut and the environment has also drawn increasing attention. In this study, we investigated the interaction between antimicrobials and sucralose impacting antimicrobial resistance and mutation of Escherichia coli (E. coli). To examine antimicrobial resistance and mutation frequency, different subinhibitory concentrations of sucralose were added to cultures of E.coli BW25113 that were then treated with antimicrobials, oxolinic acid, or moxifloxacin. Then the E.coli were assayed for bacterial survival and recovery of mutants resistant to an unrelated antimicrobial, rifampicin. Pre-treatment of E.coli BW25113 with 1/2 minimal inhibitory concentration (MIC) of sucralose increased the survival rate in oxolinic acid or moxifloxacin. A 1/3 MIC of sucralose increased rifampicin-resistant mutation rate of E.coli BW25113 after 72 h, while rifampicin-resistant mutation rate was increased when co-treated with 1/8 MIC, 1/4 MIC, 1/3 MIC sucralose, and oxolinic acid after 24 h. Sucralose can increase the antimicrobial resistance and mutation frequency of E.coli to some antimicrobials.

Animation of Antimicrobial Resistance

Medline Plus

Full Text Available ... Animal & Veterinary Safety & Health Antimicrobial Resistance Animation of Antimicrobial Resistance Share Tweet Linkedin Pin it More sharing options ... of Animation of Antimicrobial Resistance More in Antimicrobial ... Antimicrobial Resistance Monitoring System About NARMS 2015 NARMS Integrated ...

Machine learning: novel bioinformatics approaches for combating antimicrobial resistance.

Science.gov (United States)

Macesic, Nenad; Polubriaginof, Fernanda; Tatonetti, Nicholas P

2017-12-01

Antimicrobial resistance (AMR) is a threat to global health and new approaches to combating AMR are needed. Use of machine learning in addressing AMR is in its infancy but has made promising steps. We reviewed the current literature on the use of machine learning for studying bacterial AMR. The advent of large-scale data sets provided by next-generation sequencing and electronic health records make applying machine learning to the study and treatment of AMR possible. To date, it has been used for antimicrobial susceptibility genotype/phenotype prediction, development of AMR clinical decision rules, novel antimicrobial agent discovery and antimicrobial therapy optimization. Application of machine learning to studying AMR is feasible but remains limited. Implementation of machine learning in clinical settings faces barriers to uptake with concerns regarding model interpretability and data quality.Future applications of machine learning to AMR are likely to be laboratory-based, such as antimicrobial susceptibility phenotype prediction.

Combined effect of ultrasound and essential oils to reduce Listeria monocytogenes on fresh produce.

Science.gov (United States)

Özcan, Gülçin; Demirel Zorba, Nükhet Nilüfer

2016-06-01

Salads prepared from contaminated fresh produce have a high risk of causing food-borne illnesses. Essential oils obtained from plants have antimicrobial activity and may provide a natural approach to reduce the pathogens on fresh produce. Additionally, ultrasound treatments have been shown to reduce the microbial counts on different foods. The objective of this study was to investigate the antimicrobial activities of cinnamon and lemon essential oils in vitro and in food applications. Mixtures of lettuce, parsley and dill were inoculated with Listeria monocytogenes and then dip-treated for 5 min in one of the following treatments: sterile tap water, chlorinated water, 1% lemon essential oil, 2% cinnamon essential oil or 2% cinnamon essential oil + ultrasound. The samples were stored at 4 ℃ and collected at d 0, 1, 3, 5, 7 and 9 post inoculation. The 1% lemon (4 log) and 2% cinnamon (2 log) essential oil washes provided partial inhibition against L. monocytogenes by d 1. The combined application of 2% cinnamon oil and ultrasound resulted in only 0.85 log inhibition by d 1; however, the number of L. monocytogenes increased during storage and became nearly equal to the control at d 9. Therefore, different combinations of essential oils with other antimicrobials or novel technologies are required. © The Author(s) 2015.

Direct and indirect antimicrobial effects and antioxidant activity of Cordia gilletii De Wild (Boraginaceae).

Science.gov (United States)

Okusa, P N; Penge, O; Devleeschouwer, M; Duez, P

2007-07-25

Cordia gilletii De Wild (Boraginaceae) root bark is traditionally used in Democratic Republic of Congo (DRC) for the treatment of various disorders, including malaria, diarrhea, wounds and skin diseases; part of these activities may rely on antimicrobial and antioxidant properties. Successive extracts of root barks powder with n-hexane, dichloromethane, ethyl acetate, methanol and water were tested for antimicrobial activity, both direct and indirect (antibiotic resistance reversal), against 10 strains of bacteria and 1 strain of fungi by broth microdilution and agar diffusion methods. The eventual synergy between plant extracts and antibiotics was investigated by the determination of the fractional inhibitory concentration index (FIC index). The methanol extract showed direct antimicrobial activity against all tested microorganisms with minimum inhibitory concentrations (MIC) ranging between 125 and 1000 microg/ml, whereas the ethyl acetate and the dichloromethane extracts showed activity on four and three strains, respectively. 200 microg/ml of n-hexane and dichloromethane extracts decreased the MICs of penicillin and streptomycin 4-64-fold for methicillin-resistant Staphylococcus aureus. A synergistic effect was found between the methanol extract and tetracycline, whereas additive effects were observed for the other combinations tested. The methanol and dichloromethane extracts showed the greater antioxidant activity by scavenging the free radical DPPH with IC(50) values of 3.2 and 8.1 microg/ml, respectively. These results support the use of the plant in the treatment of infectious diseases and wounds; they warrant further studies as to the nature of active compounds.

Antimicrobial susceptibility of Clostridium difficile isolated in Thailand

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Papanin Putsathit

2017-06-01

Full Text Available Abstract Background Exposure to antimicrobials is the major risk factor associated with Clostridium difficile infection (CDI. Paradoxically, treatment of CDI with antimicrobials remains the preferred option. To date, only three studies have investigated the antimicrobial susceptibility of C. difficile from Thailand, two of which were published in the 1990s. This study aimed to investigate the contemporary antibiotic susceptibility of C. difficile isolated from patients in Thailand. Methods A collection of 105 C. difficile isolated from inpatients admitted at Siriraj Hospital in Bangkok in 2015 was tested for their susceptibility to nine antimicrobials via an agar incorporation method. Results All isolates were susceptible to vancomycin, metronidazole, amoxicillin/clavulanate and meropenem. Resistance to clindamycin, erythromycin and moxifloxacin was observed in 73.3%, 35.2% and 21.0% of the isolates, respectively. The in vitro activity of fidaxomicin (MIC50/MIC90 0.06/0.25 mg/L was superior to first-line therapies vancomycin (MIC50/MIC90 1/2 mg/L and metronidazole (MIC50/MIC90 0.25/0.25 mg/L. Rifaximin exhibited potent activity against 85.7% of the isolates (MIC ≤0.03 mg/L, and its MIC50 (0.015 mg/L was the lowest among all antimicrobials tested. The prevalence of multi-drug resistant C. difficile, defined by resistance to ≥3 antimicrobials, was 21.9% (23/105. Conclusions A high level of resistance against multiple classes of antimicrobial was observed, emphasising the need for enhanced antimicrobial stewardship and educational programmes to effectively disseminate information regarding C. difficile awareness and appropriate use of antimicrobials to healthcare workers and the general public.

The antimicrobial resistance crisis: causes, consequences, and management.

Science.gov (United States)

Michael, Carolyn Anne; Dominey-Howes, Dale; Labbate, Maurizio

2014-01-01

The antimicrobial resistance (AMR) crisis is the increasing global incidence of infectious diseases affecting the human population, which are untreatable with any known antimicrobial agent. This crisis will have a devastating cost on human society as both debilitating and lethal diseases increase in frequency and scope. Three major factors determine this crisis: (1) the increasing frequency of AMR phenotypes among microbes is an evolutionary response to the widespread use of antimicrobials; (2) the large and globally connected human population allows pathogens in any environment access to all of humanity; and (3) the extensive and often unnecessary use of antimicrobials by humanity provides the strong selective pressure that is driving the evolutionary response in the microbial world. Of these factors, the size of the human population is least amenable to rapid change. In contrast, the remaining two factors may be affected, so offering a means of managing the crisis: the rate at which AMR, as well as virulence factors evolve in microbial world may be slowed by reducing the applied selective pressure. This may be accomplished by radically reducing the global use of current and prospective antimicrobials. Current management measures to legislate the use of antimicrobials and to educate the healthcare world in the issues, while useful, have not comprehensively addressed the problem of achieving an overall reduction in the human use of antimicrobials. We propose that in addition to current measures and increased research into new antimicrobials and diagnostics, a comprehensive education program will be required to change the public paradigm of antimicrobial usage from that of a first line treatment to that of a last resort when all other therapeutic options have failed.

The antimicrobial resistance crisis: causes, consequences and management.

Directory of Open Access Journals (Sweden)

Carolyn Anne Michael

2014-09-01

Full Text Available The Antimicrobial Resistance (AMR crisis is the increasing global incidence of infectious diseases affecting the human population, which are untreatable with any known antimicrobial agent. This crisis will have a devastating cost on human society as both debilitating and lethal diseases increase in frequency and scope. Three major factors determine this crisis: 1/ The increasing frequency of AMR phenotypes amongst microbes is an evolutionary response to the widespread use of antimicrobials. 2/ The large and globally connected human population allows pathogens in any environment access to all of humanity. 3/ The extensive and often unnecessary use of antimicrobials by humanity provides the strong selective pressure that is driving the evolutionary response in the microbial world. Of these factors, the size of the human population is least amenable to rapid change. In contrast the remaining two factors may be affected, so offering a means of managing the crisis: The rate at which AMR, as well as virulence factors evolve in microbial world may be slowed by reducing the applied selective pressure. This may be accomplished by radically reducing the global use of current and prospective antimicrobials. Current management measures to legislate the use of antimicrobials and to educate the healthcare world in the issues, while useful, have not comprehensively addressed the problem of achieving an overall reduction in the human use of antimicrobials. We propose that in addition to current measures and increased research into new antimicrobials and diagnostics, a comprehensive education programme will be required to change the public paradigm of antimicrobial usage from that of a first line treatment to that of a last resort when all other therapeutic options have failed.

Synthesis and characterization of antimicrobial nanosilver/diatomite nanocomposites and its water treatment application

Energy Technology Data Exchange (ETDEWEB)

Xia, Yijie [Institute of Materials Research and Engineering (IMRE), Agency of Science, Technology, and Research - A*STAR, 3 Research Link, 117602 (Singapore); School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Jiang, Xiaoyu; Zhang, Jing [AGplus Technologies Pte Ltd, 10 Jalan Besar #10-06 Sim Lim Tower, 208787 (Singapore); Lin, Ming [Institute of Materials Research and Engineering (IMRE), Agency of Science, Technology, and Research - A*STAR, 3 Research Link, 117602 (Singapore); Tang, Xiaosheng [AGplus Technologies Pte Ltd, 10 Jalan Besar #10-06 Sim Lim Tower, 208787 (Singapore); Zhang, Jie, E-mail: zhangj@imre.a-star.edu.sg [Institute of Materials Research and Engineering (IMRE), Agency of Science, Technology, and Research - A*STAR, 3 Research Link, 117602 (Singapore); Liu, Hongjun, E-mail: hjliu@henu.edu.cn [Key Laboratory of Natural Medicine and Immuno-Engineering of Henan Province, Henan University, Kaifeng, Henan 475004 (China); AGplus Technologies Pte Ltd, 10 Jalan Besar #10-06 Sim Lim Tower, 208787 (Singapore)

2017-02-28

Highlights: • Nanosilver diatomite has been developed with a facile, easy and effective in–situ reduction method. • The nanosilver diatomite demonstrated great antibacterial properties to gram positive and gram–negative bacterial. • A small amount of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. • Low cost nano–composite antimicrobial material for water purification industry. - Abstract: Nanotechnology for water disinfection application gains increasing attention. Diatomite is one kind of safe natural material, which has been widely used as absorbent, filtration agents, mineral fillers, especially in water treatment industry. Nanosilver/diatomite nanocomposites were developed in this publication with a facile, effective in-situ reduction method. The as-prepared nanosilver/diatomite nanocomposites demonstrated amazing antibacterial properties to gram-positive and gram-negative bacteria. The corresponding property has been characterized by UV–vis absorbance, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). Moreover, the detailed bacteria killing experiments further displayed that 0.5 g of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. And the silver leaching test demonstrated that the concentrations of silver in the filtered water under varies pH environment were below the limit for silver level of WHO standard. Considering the low price of natural diatomite, it is believed that the nanosilver/diatomite nanocomposites have potential application in water purification industry due to its excellent antimicrobial property.

Synthesis and characterization of antimicrobial nanosilver/diatomite nanocomposites and its water treatment application

International Nuclear Information System (INIS)

Xia, Yijie; Jiang, Xiaoyu; Zhang, Jing; Lin, Ming; Tang, Xiaosheng; Zhang, Jie; Liu, Hongjun

2017-01-01

Highlights: • Nanosilver diatomite has been developed with a facile, easy and effective in–situ reduction method. • The nanosilver diatomite demonstrated great antibacterial properties to gram positive and gram–negative bacterial. • A small amount of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. • Low cost nano–composite antimicrobial material for water purification industry. - Abstract: Nanotechnology for water disinfection application gains increasing attention. Diatomite is one kind of safe natural material, which has been widely used as absorbent, filtration agents, mineral fillers, especially in water treatment industry. Nanosilver/diatomite nanocomposites were developed in this publication with a facile, effective in-situ reduction method. The as-prepared nanosilver/diatomite nanocomposites demonstrated amazing antibacterial properties to gram-positive and gram-negative bacteria. The corresponding property has been characterized by UV–vis absorbance, Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). Moreover, the detailed bacteria killing experiments further displayed that 0.5 g of the nanosilver diatomite could kill >99.999% of E. Coli within half an hour time. And the silver leaching test demonstrated that the concentrations of silver in the filtered water under varies pH environment were below the limit for silver level of WHO standard. Considering the low price of natural diatomite, it is believed that the nanosilver/diatomite nanocomposites have potential application in water purification industry due to its excellent antimicrobial property.

Presentation and antimicrobial treatment of acute orofacial infections in general dental practice.

Science.gov (United States)

Lewis, M A; Meechan, C; MacFarlane, T W; Lamey, P J; Kay, E

1989-01-21

Information on the presentation of orofacial infections and the use of antimicrobial agents in general dental practice in the United Kingdom was obtained using a postal questionnaire. Six hundred dentists were randomly selected and a total of 340 replies were received, giving a response rate of 57%. The dental practitioners estimated that acute infection was present in only a minority (approximately 5%) of patients. A total of seven different antibiotics were prescribed, in a variety of regimens, for the treatment of bacterial infection. However, the majority of dentists (46-62%) preferred a 5-day course of penicillin (250 mg, qid) for bacterial conditions other than acute ulcerative gingivitis, for which most practitioners (89%) prescribed 3 days of metronidazole (200 mg, tid). Nystatin was the most frequently selected anticandidal agent and topical acyclovir the most popular therapy for Herpes simplex infection.

Comparison of antimicrobial efficacy of chlorhexidine and combination mouth rinse in reducing the Mutans streptococcus count in plaque

Directory of Open Access Journals (Sweden)

Laxmi S Lakade

2014-01-01

Full Text Available Background: The removal of plaque is utmost important to control dental caries. But in children, factors like lack of dexterity, individual motivation and monitoring limit the effectiveness of tooth brushing. This necessitates the use of chemotherapeutic agents for control of plaque. Aims: To compare the antimicrobial efficacy of 0.2% chlorhexidine mouth rinse and mouth rinse containing 0.03% triclosan, 0.05% sodium fluoride, and 5% xylitol in reducing the Mutans streptococcus count in plaque. Materials and Methods: Thirty healthy children aged 8-10 years with dmft (decay component of three or four were selected. They were divided randomly into two groups: The control or chlorhexidine group and the study group or combination mouth rinse. Both the groups practiced rinsing with respective mouth wash for 1 min for 15 d twice a day. The plaque samples were collected and after incubation Mutans streptococcus count was estimated on the strips from the Dentocult SM kit and evaluated using manufacture′s chart. Statistical Analysis Used: Wilcoxon matched pairs signed ranks test and Mann-Whitney U test were used to analyze the findings. Results: Statistically significant reduction in the Mutans streptococci count in the plaque was seen in the control and study group from baseline level. But when both the groups were compared, the antimicrobial effect of chlorhexidine was more.

Searching for new strategies against biofilm infections: Colistin-AMP combinations against Pseudomonas aeruginosa and Staphylococcus aureus single- and double-species biofilms.

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Paula Jorge

Full Text Available Antimicrobial research is being pressured to look for more effective therapeutics for the ever-growing antibiotic-resistant infections, and antimicrobial peptides (AMP and antimicrobial combinations are promising solutions. This work evaluates colistin-AMP combinations against two major pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, encompassing non- and resistant strains. Colistin (CST combined with the AMP temporin A (TEMP-A, citropin 1.1 (CIT-1.1 and tachyplesin I linear analogue (TP-I-L was tested against planktonic, single- and double-species biofilm cultures. Overall synergy for planktonic P. aeruginosa and synergy/additiveness for planktonic S. aureus were observed. Biofilm growth prevention was achieved with synergy and additiveness. Pre-established 24 h-old biofilms were harder to eradicate, especially for S. aureus and double-species biofilms; still, some synergy and addictiveness was observed for higher concentrations, including for the biofilms of resistant strains. Different treatment times and growth media did not greatly influence AMP activity. CST revealed low toxicity compared with the other AMP but its combinations were toxic for high concentrations. Overall, combinations reduced effective AMP concentrations, mainly in prevention scenarios. Improvement of effectiveness and toxicity of therapeutic strategies will be further investigated.

Effect of Antimicrobial Dosage Regimen on Salmonella and Escherichia coli Isolates from Feeder Swine▿

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Wagner, Bruce A.; Straw, Barbara E.; Fedorka-Cray, Paula J.; Dargatz, David A.

2008-01-01

A body of evidence exists that suggests that antimicrobial use in food animals leads to resistance in both pathogenic and commensal bacteria. This study focused on the impact of three different antimicrobial regimes (low-level continuous, pulse, and no antimicrobial) for two antimicrobials (chlortetracycline and tylosin) on the presence of Salmonella spp. and on the prevalence of antimicrobial resistance of both Salmonella spp. and nonspecific Escherichia coli in fecal samples from feeder swine. The prevalence of fecal samples positive for Salmonella spp. significantly decreased between the samples taken at feeder placement compared to samples taken when the animals were close to market weight. Differences in resistance of Salmonella spp. did not appear to be influenced by dosing treatment including the control. Analysis of antimicrobial resistance examining both susceptibility and resistance, as well as MIC outcomes, demonstrated that only resistance to cephalothin increased in E. coli under the pulse chlortetracycline treatment. These results suggest that the dosing regimes examined in this study did not lead to an increase in either the prevalence of Salmonella spp. or the prevalence of antimicrobial resistance in isolates of Salmonella spp. or E. coli. PMID:18223115

Metabolic network analysis-based identification of antimicrobial drug targets in category A bioterrorism agents.

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Yong-Yeol Ahn

Full Text Available The 2001 anthrax mail attacks in the United States demonstrated the potential threat of bioterrorism, hence driving the need to develop sophisticated treatment and diagnostic protocols to counter biological warfare. Here, by performing flux balance analyses on the fully-annotated metabolic networks of multiple, whole genome-sequenced bacterial strains, we have identified a large number of metabolic enzymes as potential drug targets for each of the three Category A-designated bioterrorism agents including Bacillus anthracis, Francisella tularensis and Yersinia pestis. Nine metabolic enzymes- belonging to the coenzyme A, folate, phosphatidyl-ethanolamine and nucleic acid pathways common to all strains across the three distinct genera were identified as targets. Antimicrobial agents against some of these enzymes are available. Thus, a combination of cross species-specific antibiotics and common antimicrobials against shared targets may represent a useful combinatorial therapeutic approach against all Category A bioterrorism agents.

Effect of combined treatments on viscosity of whey dispersions

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Camillo, A.; Sabato, S.F.

2004-01-01

Whey proteins, enriched protein fractions from milk, are of great interest as ingredients due to nutritional value associated with its functional properties. These proteins could have their structural properties improved when some treatments are applied, such as thermal and gamma irradiation or when some compounds are added. The current work aimed to study the viscometer behavior of whey dispersions submitted to two different combined treatments: (1) thermal plus irradiation and (2) thermal plus vacuum and N 2 plus irradiation. Dispersions of whey protein in water (5% and 8% protein (w/v) base) and containing proteins and glycerol at ratios 1:1 and 2:1 (protein:glycerol) were submitted to both combined treatments. The irradiation doses were 0, 5, 15 and 25 kGy. The viscosity of the two combined treatments and for four levels of absorbed doses is presented and the combined effects are discussed. The thermal treatment combined with gamma irradiation contributed to increase the viscosity as irradiation doses increases for both (5% and 8%) concentrations of proteins (p<0.05). For protein and glycerol solutions, the irradiation dose seemed to result in a slightly increase. The vacuum applied before the irradiation showed a small contribution

Effect of combined treatments on viscosity of whey dispersions

Energy Technology Data Exchange (ETDEWEB)

Camillo, A.; Sabato, S.F. E-mail: sfsabato@ipen.br

2004-10-01

Whey proteins, enriched protein fractions from milk, are of great interest as ingredients due to nutritional value associated with its functional properties. These proteins could have their structural properties improved when some treatments are applied, such as thermal and gamma irradiation or when some compounds are added. The current work aimed to study the viscometer behavior of whey dispersions submitted to two different combined treatments: (1) thermal plus irradiation and (2) thermal plus vacuum and N{sub 2} plus irradiation. Dispersions of whey protein in water (5% and 8% protein (w/v) base) and containing proteins and glycerol at ratios 1:1 and 2:1 (protein:glycerol) were submitted to both combined treatments. The irradiation doses were 0, 5, 15 and 25 kGy. The viscosity of the two combined treatments and for four levels of absorbed doses is presented and the combined effects are discussed. The thermal treatment combined with gamma irradiation contributed to increase the viscosity as irradiation doses increases for both (5% and 8%) concentrations of proteins (p<0.05). For protein and glycerol solutions, the irradiation dose seemed to result in a slightly increase. The vacuum applied before the irradiation showed a small contribution.

Synergistic antimicrobial activity between pentacyclic triterpenoids and antibiotics against Staphylococcus aureus strains

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Navaratnam Parasakthi

2011-06-01

Full Text Available Abstract Background There has been considerable effort to discover plant-derived antibacterials against methicillin-resistant strains of Staphylococcus aureus (MRSA which have developed resistance to most existing antibiotics, including the last line of defence, vancomycin. Pentacyclic triterpenoid, a biologically diverse plant-derived natural product, has been reported to show anti-staphylococcal activities. The objective of this study is to evaluate the interaction between three pentacyclic triterpenoid and standard antibiotics (methicillin and vancomycin against reference strains of Staphylococcus aureus. Methods and Results The activity of the standard antibiotics and compounds on reference methicillin-sensitive and resistant strains of S. aureus were determined using the macrodilution broth method. The minimum inhibitory concentration (MIC of the compounds was compared with that of the standard antibiotics. The interaction between any two antimicrobial agents was estimated by calculating the fractional inhibitory concentration (FIC index of the combination. The various combinations of antibiotics and compounds reduced the MIC to a range of 0.05 to 50%. Conclusion Pentacyclic triterpenoids have shown anti-staphylococcal activities and although individually weaker than common antibiotics produced from bacteria and fungi, synergistically these compounds may use different mechanism of action or pathways to exert their antimicrobial effects, as implicated in the lowered MICs. Therefore, the use of current antibiotics could be maintained in their combination with plant-derived antibacterial agents as a therapeutic option in the treatment of S. aureus infections.

Cancer treatment: the combination of vaccination with other therapies

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Andersen, M.H.; Sorensen, R.B.; Schrama, D.

2008-01-01

approach to fight cancer, the combination with additional therapy could create a number of synergistic effects. Herein we discuss the possibilities and prospects of vaccination when combined with other treatments. In this regard, cell death upon drug exposure may be immunogenic or non-immunogenic depending...... and endothelial cells. The efficacy of therapeutic vaccination against cancer will over the next few years be studied in settings taking advantage of strategies in which vaccination is combined with other treatment modalities. These combinations should be based on current knowledge not only regarding the biology...... of the cancer cell per se, but also considering how treatment may influence the malignant cell population as well as the immune system Udgivelsesdato: 2008/11...

Antimicrobial Activity of Hippurate Nano composite and Its Cytotoxicity Effect in Combination with Cytarabine against HL-60

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Al Ali, S.H.H.; Al-Qubaisi, M.; Ismail, M.; El Zowalaty, M.; Hussein, M.Z.; Ismail, M.

2013-01-01

Hippuric acid (HA) was intercalated into a zinc-layered hydroxide (ZLH) by direct reaction of an aqueous suspension of zinc oxide with an aqueous solution of hippuric acid to obtain hippurate nano composite (HAN). Various concentrations of hippuric acid (0.05, 0.2, and 0.4 molar) were used for the synthesis of the nano composite. The as-synthesized HAN using 0.2 molar was found to give a well-ordered layered nano composite material with an increase in the basal spacing to 21.3 Å which indicated the insertion of hippurate organic moiety into the ZLH interlayers. The cytotoxicity of HAN in combination with cytarabine against human promyelocytic leukemia cells (HL-60) was tested using MTT cell viability assay and trypan blue dye exclusion assay. The combination of cytarabine with HAN showed higher tumor suppression efficiency as compared to that of cytarabine alone. The IC 50 values of HAN/cytarabine combination and cytarabine alone were μg/mL and μg/mL, respectively. DNA fragmentation was also studied, and the exposure of HL-60 cells to cytarabine produced % DNA fragmentation compared to % when cells were exposed to combination of cytarabine with HAN. The antimicrobial activity of hippuric acid and HAN nano composite was carried out against Gram-positive bacteria, Gram-negative bacteria, and yeasts. It was found that Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus were more sensitive to HAN compared to Bacillus subtilis and Salmonella choleraesuis

Antimicrobial effects of photodynamic therapy on patients with necrotic pulps and periapical lesion.

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Garcez, Aguinaldo Silva; Nuñez, Silvia Cristina; Hamblin, Michael R; Ribeiro, Martha Simões

2008-02-01

This study analyzed the antimicrobial effect of photodynamic therapy (PDT) in association with endodontic treatment. Twenty patients were selected. Microbiological samples were taken after accessing the canal, endodontic therapy, and PDT. At the end of the first session, the root canal was filled with Ca(OH)(2), and after 1 week, a second session of the therapies was performed. Endodontic therapy gave a mean reduction of 1.08 log. The combination with PDT significantly enhanced the reduction (1.83 log, p = 0.00002). The second endodontic session gave a similar diminution to the first (1.14 log), and the second PDT was significantly more effective than the first (p = 0.002). The second total reduction was significantly higher than the second endodontic therapy (p = 0.0000005). The total first + second reduction (3.19 log) was significantly different from the first combination (p = 0.00006). Results suggest that the use of PDT added to endodontic treatment leads to an enhanced decrease of bacterial load and may be an appropriate approach for the treatment of oral infections.

[The antibiotic policy. The Infection Committee and antimicrobial use].

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Cisneros, José Miguel; Pérez-Moreno, M Antonia; Gil-Navarro, M Victoria

2014-10-01

The antibiotic policy is the set of strategies and activities undertaken to organize the antimicrobial treatment in the hospital, and achieve health outcomes for patients. The basic principles are to be direct evidence-based medicine, local epidemiology and freedom for prescribing physicians. An antibiotic policy is now more necessary than ever for clinical, epidemiological and economic reasons. The Infection Committee is responsible for the antibiotics policy in hospitals. Its functions as an advisory body to the medical directorate are the analysis of the epidemiology of the infections in the center, measures for its prevention and control, improving the appropriate use of antimicrobials, training, and knowledge production. To achieve clinical, environmental and economic policy objectives of antibiotics is not easy. The agreement of hundreds of professionals for recommendations on indications, dosage and duration of antibiotic treatment, based on the best scientific evidence and local guides is complex, but it can be done. The key to this is that the Infection Committee develops antimicrobial stewardship through a multidisciplinary team and professional leadership, and has the institutional support to ensure that the proper use of antimicrobials is a priority for the center, and therefore of each of the services involved, and that the team has the resources for antimicrobial stewardship. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Radiation and combined treatment of Itsenko -Cushing's disease

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Barkanov, A.I.; Morozov, A.I.; Pirogov, A.I.; Postnikov, D.A.; Shadyeva, M.M.; Roshchina, V.S.; Devyatykh, Yu.N.

1980-01-01

The authors made observations of 123 patients with the Itsenko - Cushing disease. The mild form of the disease was diagnosed in 27.7 per cent of the patients; moderate in 52 percent, and severe in 20.3 per cent of the patients. A total of 78 patients underwent tele-gamma-therapy in doses of 40-45 Gy, and 45 patients underwent combined treatment consisting in unilateral adrenalectomy and irradiation with the same doses. Protracted remissions with a reverse development of the symptoms of the disease were reached in 69.2 per cent of the patients who had undergone radiation treatment and in 64.4 per cent of the patients who had undergone combined treatment. Radiotherapy was most effective in patients with mild and moderate forms of Itsenko-Cushing's disease, in case of a severe form combined treatment is indicated. Optimal single focal doses are 1.6-1.8 Gy, and cumulative ones 40-45 Gy

Increased use of antimicrobial medication in bulimia nervosa and binge-eating disorder prior to the eating disorder treatment.

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Raevuori, Anu; Lukkariniemi, Laura; Suokas, Jaana T; Gissler, Mika; Suvisaari, Jaana M; Haukka, Jari

2016-06-01

We examined the use of antimicrobial medication as a proxy for infections in large patient cohort treated for binge-eating disorder (BED), bulimia nervosa (BN), and anorexia nervosa (AN) over the five-year period preceding eating disorder treatment. Patients (N = 1592) at the Eating Disorder Unit of Helsinki University Central Hospital between 2000 and 2010 were compared with matched general population controls (N = 6368). The study population was linked to the prescription data of antibacterial, antifungal and antiviral medication from the Register on Reimbursed Prescription Medicine. Data were analyzed using regression models. Individuals with BN and BED had received more often antimicrobial medication prescriptions compared to their controls (OR: 1.7, 95% CI: 1.3-2.1; OR: 2.6, 95% CI: 1.4-4.6, respectively), while no significant difference emerged in AN (OR: 0.9, 95% CI: 0.7-1.0, p = 0.10). Of the main drug categories, the respective pattern was seen in antibacterial and antifungal medication, while increased use for antivirals appeared only in BN (OR: 1.6, 95% CI: 1.1-2.3). Measured with the mean number of prescriptions or mean Defined Daily Doses per individual, patients with BN, BED and males with AN had also higher total antimicrobial medication use. Indicating increased infections, we found elevated use of antimicrobial medication in BN, BED and in males with AN. Infections may be consequence of hyperglycemia, weight gain, or dysregulation of intestinal microbiota associated with core eating disorder behaviors. Or the other way round; changes in intestinal microbiota due to infections, inflammation, or antibacterial medications might contribute to eating disorders in multiple ways. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:542-552). © 2016 Wiley Periodicals, Inc.

Polylactic Acid-Lemongrass Essential Oil Nanocapsules with Antimicrobial Properties.

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Liakos, Ioannis L; Grumezescu, Alexandru Mihai; Holban, Alina Maria; Florin, Iordache; D'Autilia, Francesca; Carzino, Riccardo; Bianchini, Paolo; Athanassiou, Athanassia

2016-07-07

Polylactic acid was combined with lemongrass essential oil (EO) to produce functional nanocapsules (NCs). The obtained polylactic acid nanoparticles showed antimicrobial activity both with and without the presence of lemongrass oil; however, the presence of EO improved the activity of the NCs. The presence of lemongrass assisted the formation of well-separated NCs and also provided enhanced antimicrobial properties, since lemongrass is known for its antimicrobial character. Fluorescence microscopy was used to optically observe the nanoparticles and NCs and revealed the attachment of lemongrass oil with the polylactic acid NCs. Dynamic light scattering was used to determine their size. UV absorption was used to determine the exact amount of lemongrass oil found in the polylactic acid-lemongrass oil NCs, which was important for understanding the minimum inhibitory concentration for the antimicrobial experiments. A series of clinically important microbial species were used in the study and the obtained NCs proved to have very good antimicrobial properties against all tested strains. Such NCs can be used for the design of ecological strategies, based on natural alternatives, which may be efficient against severe infections, including those that involve resistant pathogens and biofilms or those with difficult to reach localization.

Polylactic Acid—Lemongrass Essential Oil Nanocapsules with Antimicrobial Properties

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Ioannis L. Liakos

2016-07-01

Full Text Available Polylactic acid was combined with lemongrass essential oil (EO to produce functional nanocapsules (NCs. The obtained polylactic acid nanoparticles showed antimicrobial activity both with and without the presence of lemongrass oil; however, the presence of EO improved the activity of the NCs. The presence of lemongrass assisted the formation of well-separated NCs and also provided enhanced antimicrobial properties, since lemongrass is known for its antimicrobial character. Fluorescence microscopy was used to optically observe the nanoparticles and NCs and revealed the attachment of lemongrass oil with the polylactic acid NCs. Dynamic light scattering was used to determine their size. UV absorption was used to determine the exact amount of lemongrass oil found in the polylactic acid—lemongrass oil NCs, which was important for understanding the minimum inhibitory concentration for the antimicrobial experiments. A series of clinically important microbial species were used in the study and the obtained NCs proved to have very good antimicrobial properties against all tested strains. Such NCs can be used for the design of ecological strategies, based on natural alternatives, which may be efficient against severe infections, including those that involve resistant pathogens and biofilms or those with difficult to reach localization.

Antimicrobial activity and phytochemical characterization of Carya illinoensis.

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Bottari, Nathieli Bianchin; Lopes, Leonardo Quintana Soares; Pizzuti, Kauana; Filippi Dos Santos Alves, Camilla; Corrêa, Marcos Saldanha; Bolzan, Leandro Perger; Zago, Adriana; de Almeida Vaucher, Rodrigo; Boligon, Aline Augusti; Giongo, Janice Luehring; Baldissera, Matheus Dellaméa; Santos, Roberto Christ Vianna

2017-03-01

Carya illinoensis is a widespread species, belonging to the Juglandaceae family, commonly known as Pecan. Popularly, the leaves have been used in the treatment of smoking as a hypoglycemic, cleansing, astringent, keratolytic, antioxidant, and antimicrobial agent. The following research aimed to identify for the first time the phytochemical compounds present in the leaves of C. illinoensis and carry out the determination of antimicrobial activity of aqueous and ethanolic extracts. The antimicrobial activity was tested against 20 microorganisms by determining the minimum inhibitory concentration (MIC). Phenolic acids (gallic acid and ellagic acid), flavonoids (rutin), and tannins (catechins and epicatechins) were identified by HPLC-DAD and may be partially responsible for the antimicrobial activity against Gram-positive, Gram-negative, and yeast. The results showed MIC values between 25 mg/mL and 0.78 mg/mL. The extracts were also able to inhibit the production of germ tubes by Candida albicans. Copyright © 2017 Elsevier Ltd. All rights reserved.

Screening of some Malay medicated oils for antimicrobial activity

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Khalid Khalisanni

2010-01-01

Full Text Available Oils from six Malay medicated oils, used traditionally in the treatment of infectious and septic diseases in humans, were tested for their antimicrobial property. The aim was to evaluate the antimicrobial properties of six Malay medicated oils against certain microbial isolates. Locally available Malay medicated oils were checked for their antimicrobial activities using six species of bacteria: E. coli, Salmonella spp., Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus, Bacillus subtilis and 2 fungi with 1 yeast (Aspergillus niger, Penicillum spp. and Candida albicans. Clove oil showed the highest antibacterial activity followed, respectively, by 'bunga merah', cajaput, nutmeg, lemon grass and 'gamat' oil. Clove oil and lemon grass showed anticandidal activity. The Malay medicated oil studies did not show any antifungal activity. The study shows that Malay medicated oils, like antibiotics, have antimicrobial activities against some microorganisms.

Antimicrobial Activity and Chemical Composition of Essential Oils from Verbenaceae Species Growing in South America

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Cristina M. Pérez Zamora

2018-03-01

Full Text Available The Verbenaceae family includes 2600 species grouped into 100 genera with a pantropical distribution. Many of them are important elements of the floras of warm-temperature and tropical regions of America. This family is known in folk medicine, and its species are used as digestive, carminative, antipyretic, antitussive, antiseptic, and healing agents. This review aims to collect information about the essential oils from the most reported species of the Verbenaceae family growing in South America, focusing on their chemical composition, antimicrobial activity, and synergism with commercial antimicrobials. The information gathered comprises the last twenty years of research within the South American region and is summarized taking into consideration the most representative species in terms of their essential oils. These species belong to Aloysia, Lantana, Lippia, Phyla, and Stachytarpheta genera, and the main essential oils they contain are monoterpenes and sesquiterpenes, such as β-caryophyllene, thymol, citral, 1,8-cineole, carvone, and limonene. These compounds have been found to possess antimicrobial activities. The synergism of these essential oils with antibiotics is being studied by several research groups. It constitutes a resource of interest for the potential use of combinations of essential oils and antibiotics in infection treatments.

Lessons Learned from Surveillance of Antimicrobial Susceptibilities of Pseudomonas aeruginosa at a Large Academic Medical Center

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Brett H. Heintz

2010-04-01

Full Text Available This research report assessed the differences in resistance rates and antimicrobial usage-versus-susceptibility relationships of Pseudomonas aeruginosa found in various hospital patient care areas. A simplified case control study was also performed to identify patient-specific risk factors associated with cefepime-resistant P. aeruginosa isolates. Last, we determined the consequence of combining mucoid and non-mucoid derived antimicrobial susceptibilities of P. aeruginosa into hospital antibiograms. Overall, susceptibility rates remained lower in the intensive care units (ICUs compared to the non-ICU patient care areas, except for cefepime over the last time period. Cefepime utilization and antimicrobial-resistance rates among P. aeruginosa isolates had a significant relationship. Decreased meropenem exposure was associated with lower resistance rates relative to cefepime. Risk factors independently associated with cefepime-resistant P. aeruginosa were structural lung disease, ICU admission, recent third generation cephalosporin use, frequent hospital admission and non-urine isolates. Large and statistically significant differences were observed between non-mucoid and combined percent susceptibility data for aminoglycosides. To control antimicrobial resistance and optimize initial empiric antimicrobial therapy, antimicrobial susceptibility and utilization patterns in specific patient care areas should be monitored and risk factors for antimicrobial resistance should be assessed. Mucoid strains of P. aeruginosa should not be included into antimicrobial susceptibility data as this may underestimate activity of most antipseudomonal agents.

Ursolic and oleanolic acids as antimicrobial and immunomodulatory compounds for tuberculosis treatment.

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Jiménez-Arellanes, Adelina; Luna-Herrera, Julieta; Cornejo-Garrido, Jorge; López-García, Sonia; Castro-Mussot, María Eugenia; Meckes-Fischer, Mariana; Mata-Espinosa, Dulce; Marquina, Brenda; Torres, Javier; Hernández-Pando, Rogelio

2013-10-07

New alternatives for the treatment of Tuberculosis (TB) are urgently needed and medicinal plants represent a potential option. Chamaedora tepejilote and Lantana hispida are medicinal plants from Mexico and their hexanic extracts have shown antimycobacterial activity. Bioguided investigation of these extracts showed that the active compounds were ursolic acid (UA) and oleanolic acid (OA). The activity of UA and OA against Mycobacterium tuberculosis H37Rv, four monoresistant strains, and two drug-resistant clinical isolates were determined by MABA test. The intracellular activity of UA and OA against M. tuberculosis H37Rv and a MDR clinical isolate were evaluated in a macrophage cell line. Finally, the antitubercular activity of UA and OA was tested in BALB/c mice infected with M. tuberculosis H37Rv or a MDR strain, by determining pulmonary bacilli loads, tissue damage by automated histomorphometry, and expression of IFN-γ, TNF-α, and iNOS by quantitative RT-PCR. The in vitro assay showed that the UA/OA mixture has synergistic activity. The intracellular activity of these compounds against M. tuberculosis H37Rv and a MDR clinical isolate in a macrophage cell line showed that both compounds, alone and in combination, were active against intracellular mycobacteria even at low doses. Moreover, when both compounds were used to treat BALB/c mice with TB induced by H37Rv or MDR bacilli, a significant reduction of bacterial loads and pneumonia were observed compared to the control. Interestingly, animals treated with UA and OA showed a higher expression of IFN-γ and TNF-α in their lungs, than control animals. UA and OA showed antimicrobial activity plus an immune-stimulatory effect that permitted the control of experimental pulmonary TB.

Development of antimicrobial films for microbiological control of packaged salad.

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Muriel-Galet, Virginia; Cerisuelo, Josep P; López-Carballo, Gracia; Lara, Marta; Gavara, Rafael; Hernández-Muñoz, Pilar

2012-07-02

The aim of the present work was to characterize the antimicrobial efficiency of films consisting of PP/EVOH structures with oregano essential oil and citral. Both substances are known for their antimicrobial activity based on their interaction with the cell membrane. The films developed were used to pack minimally processed salads, combining modified atmosphere technology to extend shelf-life and active packaging technology to reduce possible microbiological risks. The antimicrobial activity of the films against the pathogenic microorganisms Escherichia coli, Salmonella enterica and Listeria monocytogenes and natural microflora was investigated "in vitro" and also on the food itself. The effect of release of the antimicrobial agent on the sensory characteristics of the salad was also studied. The results showed that antimicrobial activity reduced spoilage flora on the salad as well as inhibited the growth of pathogens in contaminated salads. This effect was greater against Gram-negative bacteria. Sensory studies showed that the package that was most effective and most accepted by customers was the one containing 5% oregano essential oil. Copyright © 2012 Elsevier B.V. All rights reserved.

A survey of antimicrobial usage in animals in South Africa with specific reference to food animals

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Hayley Eagar

2012-08-01

Results showed that 68.5% of the antimicrobials surveyed were administered as in-feed medications. 17.5% of the total volume of antimicrobials utilised were parenteral antimicrobials, whereas antimicrobials for water medication constituted 12% of the total and ’other‘ dosage forms, for example the topical and aural dosage forms, constituted 1.5% of the total. Intramammary antimicrobials represented 0.04% of the total. The surveillance systems for veterinary antimicrobials used by other countries were scrutinised and compared. It was concluded that a combination of the surveillance systems applied by Australia and the United Kingdom is the best model (with modifications to apply to the animal health industry in South Africa. Such a surveillance system, of the volumes of veterinary antimicrobials consumed, should ideally be implemented in conjunction with a veterinary antimicrobial resistance surveillance and monitoring programme. This will generate meaningful data that will contribute to the rational administration of antimicrobials in order to preserve the efficacy of the existing antimicrobials in South Africa.

Antimicrobial resistance in the 21st century: a multifaceted challenge.

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Nolte, O

2014-04-01

Antimicrobial resistance, the ability of (pathogenic) bacteria to withstand the action of antibiotic drugs, has recently been rated of having an impact on humans similar to that of global climate change. Indeed, during the last years medicine has faced the development of highly resistant bacterial strains, which were, as a consequence of worldwide travel activity, dispersed all over the globe. This is even more astonishing if taking into account that antibiotics were introduced into human medicine not even hundred years ago. Resistance covers different principle aspects, natural resistance, acquired resistance and clinical resistance. In the modern microbiology laboratory, antimicrobial resistance is determined by measuring the susceptibility of micro-organisms in vitro in the presence of antimicrobials. However, since the efficacy of an antibiotic depends on its pharmacokinetic and pharmacodynamics properties, breakpoints are provided to translate minimal inhibitory concentration to categorical efficacy (i.e. susceptible or resistant). Resistance in one microorganism against one particular drug may drive treatment decisions of clinicians, thereby fostering selection pressure to resistance development against another antibiotic. Thereby, bacteria may acquire more and more resistance traits, ending up with multi-resistance. To this end, antimicrobial resistance becomes a public health concern, not only in terms of limited treatment options but also due to its economic burden. The current paper provides a summary of the main topics associated with antimicrobial resistance as an introduction to this special issue.

Therapeutic effects of antimicrobial treatment during lactation of recently acquired bovine subclinical mastitis: two linked randomized field trials.

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van den Borne, B H P; van Schaik, G; Lam, T J G M; Nielen, M

2010-01-01

Two linked randomized field trials were performed on 39 herds in the Netherlands to 1) determine therapeutic effects of antimicrobial treatment of recently acquired subclinical mastitis (RASCM) during lactation, 2) evaluate the effect of duration of subclinical mastitis on therapeutic outcome, and 3) identify factors related to the therapeutic success of RASCM. Cows with a first elevated composite somatic cell count (CSCC) after 2 consecutive low CSCC measurements were eligible for enrollment in trial 1 (treatment at the first elevated CSCC). Quarter milk samples were collected to determine bacteriological status for major pathogens and coagulase-negative staphylococci. Cows with one or more culture-positive quarters with a quarter somatic cell count (QSCC) >or=100,000 cells/mL were defined to have RASCM and were randomly assigned treatment or control (no treatment). Untreated cows from trial 1 that had a second elevated CSCC at the next milk recording were eligible for enrollment in trial 2 (treatment at the second elevated CSCC). In trial 2, staphylococci-positive cows (Staphylococcus aureus and coagulase-negative staphylococci) were randomly assigned to treatment or control. Farmers used their own treatment protocols to treat quarters in both trials. Bacteriological cure was defined as absence of the pathogen identified pre-intervention in 2 samples post-intervention; QSCC, CSCC, and milk yield were also analyzed. Hierarchical logistic and linear models were used to determine therapeutic effects and to identify factors related to therapy outcome. Treated quarters had a higher bacteriological cure rate than control quarters for all pathogens in both trials. Treatment resulted in lower QSCC and CSCC, whereas milk yield was not affected by treatment. Bacteriological cure of RASCM was better in quarters with a low QSCC pre-intervention and in coagulase-negative staphylococci-positive quarters. Control quarters with a single culture-positive sample pre

Risk factors associated with the antimicrobial resistance of Staphylococcus aureus isolated from bovine mastitis

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Daniele C. Beuron

2014-10-01

Full Text Available The objective of this study was to evaluate herd management practices and mastitis treatment procedures as risk factors associated with Staphylococcus aureus antimicrobial resistance. For this study, 13 herds were selected to participate in the study to evaluate the association between their management practices and mastitis treatment procedures and in vitro antimicrobial susceptibility. A total of 1069 composite milk samples were collected aseptically from the selected cows in four different periods over two years. The samples were used for microbiological culturing of S. aureus isolates and evaluation of their antimicrobial susceptibility. A total of 756 samples (70.7% were culture-positive, and S. aureus comprised 27.77% (n=210 of the isolates. The S. aureus isolates were tested using the disk-diffusion susceptibility assay with the following antimicrobials: ampicillin 10mg; clindamycin 2μg; penicillin 1mg; ceftiofur 30μg; gentamicin 10mg; sulfa-trimethoprim 25μg; enrofloxacin 5μg; sulfonamide 300μg; tetracycline 30μg; oxacillin 1mg; cephalothin 30μg and erythromycin 5μg. The variables that were significantly associated with S. aureus resistance were as follows: the treatment of clinical mastitis for ampicillin (OR=2.18, dry cow treatment for enrofloxacin (OR=2.11 and not sending milk samples for microbiological culture and susceptibility tests, for ampicillin (OR=2.57 and penicillin (OR=4.69. In conclusion, the identification of risk factors for S. aureus resistance against various mastitis antimicrobials is an important information that may help in practical recommendations for prudent use of antimicrobial in milk production.

Effect of Ultrasonic Treatment Combined with Peracetic Acid Treatment Reduces Decay and Maintains Quality in Loquat Fruit

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Chen Ling

2018-01-01

Full Text Available The effects of ultrasonic treatment (UT, 400 watts for 6 min combined with peracetic acid (PA, 0.4% (W/W treatment on fruit decay, browning, and quality and physiological changes in loquat fruit stored at 20°C were investigated. The results showed that treatment with UT or PA alone significantly reduced both decay and browning index in loquat fruit compared with the control. The combined treatment was more effective in decreasing decay and browning index and maintaining higher quality parameters than UT or PA treatment alone. Loquat fruits treated with the combined treatment maintained higher activities of polyphenol oxidase (PPO and peroxidase (POD than those treated with other treatments. In addition, UT combined with PA treatment significantly reduced the increase of firmness and increased fruit extractable juice, total soluble solid (TSS, and ascorbic acid content in loquat fruit. Moreover, the contents of total phenolics and total flavonoids were enhanced by the combination of UT and PA treatment. The combination of UT and PA treatment could be a useful method to reduce decay and browning in loquat fruit stored at room temperature, which has potential for application in the loquat industry.

Bio-inspired crosslinking and matrix-drug interactions for advanced wound dressings with long-term antimicrobial activity.

Science.gov (United States)

Dhand, Chetna; Venkatesh, Mayandi; Barathi, Veluchami Amutha; Harini, Sriram; Bairagi, Samiran; Goh Tze Leng, Eunice; Muruganandham, Nandhakumar; Low, Kenny Zhi Wei; Fazil, Mobashar Hussain Urf Turabe; Loh, Xian Jun; Srinivasan, Dinesh Kumar; Liu, Shou Ping; Beuerman, Roger W; Verma, Navin Kumar; Ramakrishna, Seeram; Lakshminarayanan, Rajamani

2017-09-01

There is a growing demand for durable advanced wound dressings for the management of persistent infections after deep burn injuries. Herein, we demonstrated the preparation of durable antimicrobial nanofiber mats, by taking advantage of strong interfacial interactions between polyhydroxy antibiotics (with varying number of OH groups) and gelatin and their in-situ crosslinking with polydopamine (pDA) using ammonium carbonate diffusion method. Polydopamine crosslinking did not interfere with the antimicrobial efficacy of the loaded antibiotics. Interestingly, incorporation of antibiotics containing more number of alcoholic OH groups (N OH  ≥ 5) delayed the release kinetics with complete retention of antimicrobial activity for an extended period of time (20 days). The antimicrobials-loaded mats displayed superior mechanical and thermal properties than gelatin or pDA-crosslinked gelatin mats. Mats containing polyhydroxy antifungals showed enhanced aqueous stability and retained nanofibrous morphology under aqueous environment for more than 4 weeks. This approach can be expanded to produce mats with broad spectrum antimicrobial properties by incorporating the combination of antibacterial and antifungal drugs. Direct electrospinning of vancomycin-loaded electrospun nanofibers onto a bandage gauze and subsequent crosslinking produced non-adherent durable advanced wound dressings that could be easily applied to the injured sites and readily detached after treatment. In a partial thickness burn injury model in piglets, the drug-loaded mats displayed comparable wound closure to commercially available silver-based dressings. This prototype wound dressing designed for easy handling and with long-lasting antimicrobial properties represents an effective option for treating life-threatening microbial infections due to thermal injuries. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Antimicrobial consumption at Auckland City Hospital: 2006-2009.

Science.gov (United States)

Ticehurst, Rob; Thomast, Mark

2011-04-15

We aimed to determine the level of antimicrobial consumption by adult inpatients at Auckland City Hospital (Auckland, New Zealand) and to compare our findings with those in other developed nations. We used the computerised records of the central Auckland District Health Board (ADHB) pharmacy to measure the amount of antimicrobials dispensed to inpatients (excluding psychiatric units, day stay units and outpatient clinics) during 2006 to 2009. The total weight of each antimicrobial dispensed was used to determine the number of defined daily doses (DDDs) dispensed. The Information Management and Technical Services department of ADHB provided data on the number of admissions and inpatient days, and these data, together with information from the 2006 census, were used to calculate antimicrobial consumption for adult inpatients measured in DDDs/100 admissions, DDDs/100 inpatient days and DDDs/1000 population. Total antimicrobial consumption by adult inpatients increased from 74 DDDs/100 inpatient days in 2006 to 80.3 DDDs/100 inpatient days in 2009. The level of consumption did not vary greatly with the season. The total level of consumption was very similar to that seen in adult inpatients in hospitals in Australia and Scandinavian countries. The level of consumption of fluoroquinolones, third or fourth generation cephalosporins, carbapenems and vancomycin (antimicrobial classes that are not available for unrestricted use in Auckland City Hospital) was comparable to or less than that seen in adult inpatients in hospitals in Australia or Scandinavian countries. Beta-lactamase susceptible penicillins (such as benzyl penicillin and phenoxymethylpenicillin) comprised a relatively small proportion of total penicillin use and beta-lactamase inhibitor combinations (predominantly amoxicillin/clavulanate) a relatively large proportion of total penicillin use, when compared with Scandinavian hospitals. The antimicrobial stewardship programme at Auckland City Hospital has

Antimicrobial resistance in community and nosocomial Escherichia coli urinary tract isolates, London 2005 – 2006

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Wareham David W

2008-06-01

Full Text Available Abstract Background Escherichia coli is the commonest cause of community and nosocomial urinary tract infection (UTI. Antibiotic treatment is usually empirical relying on susceptibility data from local surveillance studies. We therefore set out to determine levels of resistance to 8 commonly used antimicrobial agents amongst all urinary isolates obtained over a 12 month period. Methods Antimicrobial susceptibility to ampicillin, amoxicillin/clavulanate, cefalexin, ciprofloxacin, gentamicin, nitrofurantoin, trimethoprim and cefpodoxime was determined for 11,865 E. coli urinary isolates obtained from community and hospitalised patients in East London. Results Nitrofurantoin was the most active agent (94% susceptible, followed by gentamicin and cefpodoxime. High rates of resistance to ampicillin (55% and trimethoprim (40%, often in combination were observed in both sets of isolates. Although isolates exhibiting resistance to multiple drug classes were rare, resistance to cefpodoxime, indicative of Extended spectrum β-lactamase production, was observed in 5.7% of community and 21.6% of nosocomial isolates. Conclusion With the exception of nitrofurantoin, resistance to agents commonly used as empirical oral treatments for UTI was extremely high. Levels of resistance to trimethoprim and ampicillin render them unsuitable for empirical use. Continued surveillance and investigation of other oral agents for treatment of UTI in the community is required.

Systemic combination treatment for psoriasis: a review

DEFF Research Database (Denmark)

Jensen, Peter; Skov, Lone; Zachariae, Claus

2010-01-01

Psoriasis is a chronic inflammatory skin disease, which affects approximately 2.6% of the population in Northern Europe and Scandinavia. In order to achieve disease control, combinations of systemic treatments are sometimes needed for variable time periods. However, no evidence-based guidelines...... exist for the use of systemic combination therapy. Therefore, our aim was to review the current literature on systemic anti-psoriatic combination regimens. We searched PubMed and identified 98 papers describing 116 studies (23 randomized) reporting on the effect of various systemic combination...

In Vitro Antimicrobial Photodynamic Therapy Against Trichophyton mentagrophytes Using New Methylene Blue as the Photosensitizer.

Science.gov (United States)

López-Chicón, P; Gulías, Ò; Nonell, S; Agut, M

2016-11-01

Antimicrobial photodynamic therapy combines the use of a photosensitizing drug with light and oxygen to eradicate pathogens. Trichophyton mentagrophytes is a dermatophytic fungus able to invade the skin and keratinized tissues. We have investigated the use of new methylene blue as the photosensitizing agent for antimicrobial photodynamic therapy to produce the in vitro inactivation of T mentagrophytes. A full factorial design was employed to optimize the parameters for photoinactivation of the dermatophyte. The parameters studied were new methylene blue concentration, contact time between the photosensitizing agent and the fungus prior to light treatment, and the fluence of red light (wavelength, 620-645nm) applied. The minimum concentration of new methylene blue necessary to induce the death of all T. mentagrophytes cells in the initial suspension (approximate concentration, 10 6 colony forming units per milliliter) was 50μM for a fluence of 81J/cm 2 after a contact time of 10minutes with the photosensitizing-agent. Increasing the concentration to 100μM allowed the fluence to be decreased to 9J/cm 2 . Comparison of our data with other published data shows that the susceptibility of T. mentagrophytes to antimicrobial photodynamic therapy with new methylene blue is strain-dependent. New methylene blue is a photosensitizing agent that should be considered for the treatment of fungal skin infections caused by this dermatophyte. Copyright © 2016 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Combined endoscopic approaches to the cardiac sphincter achalasia treatment

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V. N. Klimenko

2015-12-01

Full Text Available Aim. To assess combined endoscopic approaches to the cardiac sphincter achalasia treatment. Results. There are preliminary results of treatment and methods of carrying out of combined endoscopic pneumocardiodilatation and injections of botulotoxin type A ‘Disport’ at achalasia cardia are described in the article. Aethio-pathogenetic aspects in the development of achalasia cardia, action of botulotoxin type A and balloon pneumocardiodilatation of the esophagus, were described. And modern roentgen-endoscopic classification of achalasia cardia was given. Prognostic estimation scale of possibility to implement further combined endoscopic or surgical treatment is defined and is being in subsequent working out. Conclusion. Described clinical cases most brightly demonstrate variety of clinical achalasia cardia manifestations and also determine of the earlier display of surgical treatment.

Real-Time Optical Antimicrobial Susceptibility Testing

DEFF Research Database (Denmark)

Fredborg, Marlene; Andersen, Klaus R; Jørgensen, Erik

2013-01-01

Rapid antibiotic susceptibility testing is in highly demand in health-care fields as antimicrobial resistant bacterial strains emerge and spread. Here we describe an optical screening system (oCelloScope), which based on time-lapse imaging of 96 bacteria-antibiotic combinations at a time......, introduces real-time detection of bacterial growth and antimicrobial susceptibility, with imaging material to support the automatically generated graphs. Automated antibiotic susceptibility tests of a monoculture showed statistically significant antibiotic effect within 6 minutes and within 30 minutes...... from multidrug-resistant pathogenic bacteria. The oCelloScope system can be employed for a broad range of applications within bacteriology and may present new vistas as a point-of-care instrument in both clinical and veterinarian settings....

Synergistic effect of high pressure processing and Lactobacillus casei antimicrobial activity against pressure resistant Listeria monocytogenes.

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Chung, Hyun-Jung; Yousef, Ahmed E

2010-09-30

The purpose of this study was to evaluate combinations of high pressure processing (HPP) and Lactobacillus casei antimicrobial activity against Listeria monocytogenes strains with variation in pressure resistance in culture and in a food model. In culture, combination of HPP (350 MPa, for 1-20 min) and Lb. casei cell extract (CE, 32 CEAU/ml) showed a significant synergistic bactericidal effect (P5 log(10)CFU/ml. Synergy between CE and HPP was most evident in the pressure-resistant strain, OSY-8578. Similar result was observed in meat products where high pressure (500 MPa for 1 min), and high-activity CE (100 CEAU/g) caused >5 log reduction in the viability of L. monocytogenes Scott A. The combination treatment resulted in the absence of peaks associated with cellular components in DSC thermogram suggesting that the presence of CE may have caused a considerable damage to cellular components during the high pressure treatment. Copyright 2010 Elsevier B.V. All rights reserved.

Silver nanoparticles: Antimicrobial activity, cytotoxicity, and synergism with N-acetyl cysteine.

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Hamed, Selwan; Emara, Mohamed; Shawky, Riham M; El-Domany, Ramadan A; Youssef, Tareq

2017-08-01

The fast progression of nanotechnology has led to novel therapeutic interventions. Antimicrobial activities of silver nanoparticles (Ag NPs) were tested against standard ATCC strains of Staphylococcus aureus (ATCC 9144), Escherichia coli (O157:H7), Pseudomonas aeruginosa (ATCC 27853), and Candida albicans (ATCC 90028) in addition to 60 clinical isolates collected from cancer patients. Antimicrobial activity was tested by disk diffusion method and MIC values for Ag NPs alone and in combination with N-acetylcysteine (NAC) against tested pathogens were determined by broth microdilution method. Ag NPs showed a robust antimicrobial activity against all tested pathogens and NAC substantially enhanced the antimicrobial activity of Ag NPs against all tested pathogens. Synergism between Ag NPs and NAC has been confirmed by checkerboard assay. The effect of Ag NPs on tested pathogens was further scrutinized by Transmission Electron Microscope (TEM) which showed disruption of cell wall in both bacteria and fungi. Ag NPs abrogated the activity of respiratory chain dehydrogenase of all tested pathogens and released muramic acid content from S. aureus in culture. The cytotoxic effect of Ag NPs alone and in combination with NAC was examined using human HepG2 cells and this revealed no cytotoxicity at MIC values of Ag NPs and interestingly, NAC reduced the cytotoxic effect of Ag NPs at concentrations higher than their MIC values. Taken together, Ag NPs have robust antimicrobial activity and NAC substantially enhances their antimicrobial activities against MDR pathogens which would provide a novel safe, effective, and inexpensive therapeutic approach to control the prevalence of MDR pathogens. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectroscopic and antimicrobial studies of polystyrene films under ...

Indian Academy of Sciences (India)

Spectroscopic and antimicrobial studies of polystyrene films under air plasma and He-Ne laser treatment ... The parameters such as (1) surface area by contact angle measurements, (2) quality of material before and after treatment by SEM and FTIR spectra and (3) material characterization by UV-vis spectra were studied.

Same day identification and full panel antimicrobial susceptibility testing of bacteria from positive blood culture bottles made possible by a combined lysis-filtration method with MALDI-TOF VITEK mass spectrometry and the VITEK2 system.

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Alexandra Machen

Full Text Available Rapid identification and antimicrobial susceptibility testing of microorganisms causing bloodstream infections or sepsis have the potential to improve patient care. This proof-of-principle study evaluates the Lysis-Filtration Method for identification as well as antimicrobial susceptibility testing of bacteria directly from positive blood culture bottles in a clinical setting. A total of 100 non-duplicated positive blood cultures were tested and 1012 microorganism-antimicrobial combinations were assessed. An aliquot of non-charcoal blood culture broth was incubated with lysis buffer briefly before being filtered and washed. Microorganisms recovered from the filter membrane were first identified by using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight VITEK® Mass Spectrometry (VITEK MS. After quick identification from VITEK MS, filtered microorganisms were inoculated to VITEK®2 system for full panel antimicrobial susceptibility testing analysis. Of 100 bottles tested, the VITEK MS resulted in 94.0% correct organism identification to the species level. Compared to the conventional antimicrobial susceptibility testing methods, direct antimicrobial susceptibility testing from VITEK®2 resulted in 93.5% (946/1012 category agreement of antimicrobials tested, with 3.6% (36/1012 minor error, 1.7% (7/1012 major error, and 1.3% (13/1012 very major error of antimicrobials. The average time to identification and antimicrobial susceptibility testing was 11.4 hours by using the Lysis-Filtration method for both VITEK MS and VITEK®2 compared to 56.3 hours by using conventional methods (p<0.00001. Thus, the same-day results of microorganism identification and antimicrobial susceptibility testing directly from positive blood culture can be achieved and can be used for appropriate antibiotic therapy and antibiotic stewardship.

Same Day Identification and Full Panel Antimicrobial Susceptibility Testing of Bacteria from Positive Blood Culture Bottles Made Possible by a Combined Lysis-Filtration Method with MALDI-TOF VITEK Mass Spectrometry and the VITEK2 System

Science.gov (United States)

Machen, Alexandra; Drake, Tim; Wang, Yun F. (Wayne)

2014-01-01

Rapid identification and antimicrobial susceptibility testing of microorganisms causing bloodstream infections or sepsis have the potential to improve patient care. This proof-of-principle study evaluates the Lysis-Filtration Method for identification as well as antimicrobial susceptibility testing of bacteria directly from positive blood culture bottles in a clinical setting. A total of 100 non-duplicated positive blood cultures were tested and 1012 microorganism-antimicrobial combinations were assessed. An aliquot of non-charcoal blood culture broth was incubated with lysis buffer briefly before being filtered and washed. Microorganisms recovered from the filter membrane were first identified by using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight VITEK® Mass Spectrometry (VITEK MS). After quick identification from VITEK MS, filtered microorganisms were inoculated to VITEK®2 system for full panel antimicrobial susceptibility testing analysis. Of 100 bottles tested, the VITEK MS resulted in 94.0% correct organism identification to the species level. Compared to the conventional antimicrobial susceptibility testing methods, direct antimicrobial susceptibility testing from VITEK®2 resulted in 93.5% (946/1012) category agreement of antimicrobials tested, with 3.6% (36/1012) minor error, 1.7% (7/1012) major error, and 1.3% (13/1012) very major error of antimicrobials. The average time to identification and antimicrobial susceptibility testing was 11.4 hours by using the Lysis-Filtration method for both VITEK MS and VITEK®2 compared to 56.3 hours by using conventional methods (p<0.00001). Thus, the same-day results of microorganism identification and antimicrobial susceptibility testing directly from positive blood culture can be achieved and can be used for appropriate antibiotic therapy and antibiotic stewardship. PMID:24551067

Synthesis, Characterization, and In Vivo Efficacy of Shell Cross-Linked Nanoparticle Formulations Carrying Silver Antimicrobials as Aerosolized Therapeutics

Science.gov (United States)

2014-01-01

The use of nebulizable, nanoparticle-based antimicrobial delivery systems can improve efficacy and reduce toxicity for treatment of multi-drug-resistant bacteria in the chronically infected lungs of cystic fibrosis patients. Nanoparticle vehicles are particularly useful for applying broad-spectrum silver-based antimicrobials, for instance, to improve the residence time of small-molecule silver carbene complexes (SCCs) within the lung. Therefore, we have synthesized multifunctional, shell cross-linked knedel-like polymeric nanoparticles (SCK NPs) and capitalized on the ability to independently load the shell and core with silver-based antimicrobial agents. We formulated three silver-loaded variants of SCK NPs: shell-loaded with silver cations, core-loaded with SCC10, and combined loading of shell silver cations and core SCC10. All three formulations provided a sustained delivery of silver over the course of at least 2–4 days. The two SCK NP formulations with SCC10 loaded in the core each exhibited excellent antimicrobial activity and efficacy in vivo in a mouse model of Pseudomonas aeruginosa pneumonia. SCK NPs with shell silver cation-load only, while efficacious in vitro, failed to demonstrate efficacy in vivo. However, a single dose of core SCC10-loaded SCK NPs (0.74 ± 0.16 mg Ag) provided a 28% survival advantage over sham treatment, and administration of two doses (0.88 mg Ag) improved survival to 60%. In contrast, a total of 14.5 mg of Ag+ delivered over 5 doses at 12 h intervals was necessary to achieve a 60% survival advantage with a free-drug (SCC1) formulation. Thus, SCK NPs show promise for clinical impact by greatly reducing antimicrobial dosage and dosing frequency, which could minimize toxicity and improve patient adherence. PMID:23718195

Novel method to identify the optimal antimicrobial peptide in a combination matrix, using anoplin as an example

DEFF Research Database (Denmark)

Munk, Jens; Ritz, Christian; Fliedner, Frederikke Petrine

2014-01-01

retention time data, we construct analysis of variance models that describe the relationship between these properties and structural characteristics of the analogs. We show that the mathematical models derived from the training set data can be used to predict the properties of other analogs in the chemical......Microbial resistance is an increasing health concern and a true danger to human wellbeing. A worldwide search for new compounds is ongoing and antimicrobial peptides are promising lead candidates for tomorrow's antibiotics. The decapeptide anoplin, GLLKRIKTLL-NH2, is an especially interesting...... candidate because of its small size as well as its antimicrobial and nonhemolytic properties. Optimization of the properties of an antimicrobial peptide such as anoplin requires multidimensional searching in a complex chemical space. Typically such optimization is performed by labor-intensive and costly...

Chemical compositions and antimicrobial activities of Athrixia phylicoides DC. (bush tea), Monsonia burkeana (special tea) and synergistic effects of both combined herbal teas.

Science.gov (United States)

Tshivhandekano, Itani; Ntushelo, Khayalethu; Ngezimana, Wonder; Tshikalange, Thilivhali Emmanuel; Mudau, Fhatuwani Nixwell

2014-09-01

To determine the chemical compositions and evaluate the antimicrobial activity of bush tea (Athrixia phylicoides DC.), special tea (Monsonia burkeana) and synergy (combination of bush tea and special tea). Total polyphenols were determined using the methods reported by Singleton and Rossi (1965) and modified by Waterman and Mole (1994). Tannins were determined using vanillin HCL methods described by Prince et al. (1978). Total antioxidants were determined using the methods described by Awika et al. (2004). The micro dilution technique using 96-well micro-plates, as described by Eloff (1998) was used to obtain the minimum inhibition concentration (MIC) and minimum microbicidal concentration (MMC) values of the ethanol extracts against the microorganisms under study. The microbes strain used was Gram negative bacteria such as Escherichia coli, Klebsiella oxytoca, Proteus vulgaris, Serratia marcescens, Salmonella typhi, Klebsiella pneumonia; Gram positive bacteria such as Bacillus cereus, Staphylococcus aureus and a fungus Candida albicans. The results demonstrated that special tea contains significantly higher content of total polyphenols (8.34 mg/100 g) and total antioxidant (0.83 mg/100 g) as compared to bush tea [total polyphenols (6.41 mg/100g) and total antioxidant (0.63 mg/100g)] and combination of bush tea and special tea [total polyphenols (6.42 mg/100 g) and total antioxidant (0.64 mg/100 g)]. There was no significant difference in tannins between bush tea, special tea and synergy. The results of antimicrobial activity (MIC and MMC) demonstrated that the ethanol extracts of bush tea, special tea and synergy possessed antimicrobial activity against all microorganisms at different zones. The MIC of bush tea ranged from 1.56 to 12.50 mg/mL while the MMC ranged from 0.78 to 12.50 mg/mL. Special tea's MIC ranged from 0.39 to 12.50 mg/mL while the MMC ranged from 0.01 to 12.50 mg/mL. The MIC of synergy ranged from 3.13 to 12.50 mg/mL while the MMC ranged from 3

Electrofabrication of functional materials: Chloramine-based antimicrobial film for infectious wound treatment.

Science.gov (United States)

Qu, Xue; Liu, Huan; Zhang, Chuchu; Lei, Yu; Lei, Miao; Xu, Miao; Jin, Dawei; Li, Peng; Yin, Meng; Payne, Gregory F; Liu, Changsheng

2018-06-01

Electrical signals can be imposed with exquisite spatiotemporal control and provide exciting opportunities to create structure and confer function. Here, we report the use of electrical signals to program the fabrication of a chloramine wound dressing with high antimicrobial activity. This method involves two electrofabrication steps: (i) a cathodic electrodeposition of an aminopolysaccharide chitosan triggered by a localized region of high pH; and (ii) an anodic chlorination of the deposited film in the presence of chloride. This electrofabrication process is completed within several minutes and the chlorinated chitosan can be peeled from the electrode to yield a free-standing film. The presence of active NCl species in this electrofabricated film was confirmed with chlorination occurring first on the amine groups and then on the amide groups when large anodic charges were used. Electrofabrication is quantitatively controllable as the cathodic input controls film growth during deposition and the anodic input controls film chlorination. In vitro studies demonstrate that the chlorinated chitosan film has antimicrobial activities that depend on the chlorination degree. In vivo studies with a MRSA infected wound healing model indicate that the chlorinated chitosan film inhibited bacterial growth, induced less inflammation, developed reorganized epithelial and dermis structures, and thus promoted wound healing compared to a bare wound or wound treated with unmodified chitosan. These results demonstrate the fabrication of advanced functional materials (i.e., antimicrobial wound dressings) using controllable electrical signals to both organize structure through non-covalent interactions (i.e., induce chitosan's reversible self-assembly) and to initiate function-conferring covalent modifications (i.e., generate chloramine bonds). Potentially, electrofabrication may provide a simple, low cost and sustainable alternative for materials fabrication. We believe this work is

Same day identification and full panel antimicrobial susceptibility testing of bacteria from positive blood culture bottles made possible by a combined lysis-filtration method with MALDI-TOF VITEK mass spectrometry and the VITEK2 system.

Science.gov (United States)

Machen, Alexandra; Drake, Tim; Wang, Yun F Wayne

2014-01-01

Rapid identification and antimicrobial susceptibility testing of microorganisms causing bloodstream infections or sepsis have the potential to improve patient care. This proof-of-principle study evaluates the Lysis-Filtration Method for identification as well as antimicrobial susceptibility testing of bacteria directly from positive blood culture bottles in a clinical setting. A total of 100 non-duplicated positive blood cultures were tested and 1012 microorganism-antimicrobial combinations were assessed. An aliquot of non-charcoal blood culture broth was incubated with lysis buffer briefly before being filtered and washed. Microorganisms recovered from the filter membrane were first identified by using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight VITEK® Mass Spectrometry (VITEK MS). After quick identification from VITEK MS, filtered microorganisms were inoculated to VITEK®2 system for full panel antimicrobial susceptibility testing analysis. Of 100 bottles tested, the VITEK MS resulted in 94.0% correct organism identification to the species level. Compared to the conventional antimicrobial susceptibility testing methods, direct antimicrobial susceptibility testing from VITEK®2 resulted in 93.5% (946/1012) category agreement of antimicrobials tested, with 3.6% (36/1012) minor error, 1.7% (7/1012) major error, and 1.3% (13/1012) very major error of antimicrobials. The average time to identification and antimicrobial susceptibility testing was 11.4 hours by using the Lysis-Filtration method for both VITEK MS and VITEK®2 compared to 56.3 hours by using conventional methods (pdirectly from positive blood culture can be achieved and can be used for appropriate antibiotic therapy and antibiotic stewardship.

Microbiological aspects of an in situ model to study effects of antimicrobial agents on dental plaque ecology.

Science.gov (United States)

Giertsen, E; Guggenheim, B; Thurnheer, T; Gmür, R

2000-10-01

This study validates an in situ model for ecological studies of dental plaque exposed to various antimicrobial agents with different modes of action on plaque bacteria. Eleven subjects wore two acrylic appliances, each containing two bovine enamel discs, during two 1-wk test periods. Using a split-mouth crossover design, the appliances were dipped twice daily for 1 min into water (control; treatment A), fluoride (26.3 mM NaF; B), zinc acetate (20.0 mM; C), or fluoride plus zinc acetate (D). Four of the subjects used also chlorhexidine diacetate (2.2 mM; E) and chlorhexidine plus fluoride (F). At the end of each period, plaque was collected from the discs, after which the microbiota were analyzed by culture, automated quantitative immunofluorescence, and a viability fluorescence stain. As compared to control, treatments B, C, and D resulted in a significant reduction of individual taxa as detected by immunofluorescence, whereas similar bacterial viability and total bacterial numbers were observed. In contrast, chlorhexidine significantly reduced bacterial viability, total cell numbers, and the abundance of most of the enumerated taxa. We conclude that this in situ model is well suited to study effects of antimicrobial agents on dental plaque ecology. Combined with viability testing, immunofluorescence is obviously superior to culture in detecting taxa-specific shifts caused by antimicrobial agents.

Metal oxide nanoparticles as antimicrobial agents: a promise for the future.

Science.gov (United States)

Raghunath, Azhwar; Perumal, Ekambaram

2017-02-01

Microbial infectious diseases are a global threat to human health. Excess and improper use of antibiotics has created antimicrobial-resistant microbes that can defy clinical treatment. The hunt for safe and alternate antimicrobial agents is on in order to overcome such resistant micro-organisms, and the birth of nanotechnology offers promise to combat infectious organisms. Over the past two decades, metal oxide nanoparticles (MeO-NPs) have become an attractive alternative source to combat microbes that are highly resistant to various classes of antibiotics. Their vast array of physicochemical properties enables MeO-NPs to act as antimicrobial agents through various mechanisms. Apart from exhibiting antimicrobial properties, MeO-NPs also serve as carriers of drugs, thus barely providing a chance for micro-organisms to develop resistance. These immense multiple properties exhibited by MeO-NPs will have an impact on the treatment of deadly infectious diseases. This review discusses the mechanisms of action of MeO-NPs against micro-organisms, safety concerns, challenges and future perspectives. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Eradication of Salmonella Typhimurium infection in a murine model of typhoid fever with the combination of probiotic Lactobacillus fermentum ME-3 and ofloxacin

Directory of Open Access Journals (Sweden)

Karki Tõnis

2008-08-01

Full Text Available Abstract Background The aim of the study was to detect whether in experimental Salmonella enterica Typhimurium infection the probiotic Lactobacillus fermentum ME-3 in combination with fluoroquinolone therapy would eradicate S. Typhimurium, prevent the development of liver and spleen granulomas and improve the indices of oxidative stress in the ileum mucosa. The selected bacteriological, histological and biochemical methods were applied. Results Combined treatment with L. fermentum ME-3 and ofloxacin eradicated Salmonella Typhimurium from blood, ileum and liver, decreased the number of animals with liver and spleen granulomas and reduced the value of lipid peroxides in the ileum mucosa. Higher total counts of intestinal lactobacilli in all experimental groups were associated with the absence of liver granulomas. Conclusion The antimicrobial and antioxidative probiotic L. fermentum ME-3 combined with ofloxacin enhances the eradication of experimental S. Typhimurium infection. These observations on probiotic and antimicrobial co-action may serve as basis to develop new strategies for treatment of invasive bacterial infections of the gut.

The antimicrobial resistance containment and surveillance approach--a public health tool.

Science.gov (United States)

Simonsen, Gunnar S.; Tapsall, John W.; Allegranzi, Benedetta; Talbot, Elizabeth A.; Lazzari, Stefano

2004-01-01

Antimicrobial drug resistance (AMR) is widely recognized as a global public health threat because it endangers the effectiveness of treatment of infectious diseases. In 2001 WHO issued the Global Strategy for Containment of Antimicrobial Resistance, but it has proved difficult to translate the recommendations of the Global Strategy into effective public health actions. The purpose of the Antimicrobial Resistance Containment and Surveillance (ARCS) approach is to facilitate the formulation of public health programmes and the mobilization of human and financial resources for the containment of AMR. The ARCS approach highlights the fundamental link between rational drug use and containment of AMR. Clinical management of human and animal infections should be improved through better disease control and prevention, high quality diagnostic testing, appropriate treatment regimens and consumer health education. At the same time, systems for supplying antimicrobial drugs should include appropriate regulations, lists of essential drugs, and functional mechanisms for the approval and delivery of drugs. Containment of AMR is defined in the ARCS approach as the continuous application of this package of core interventions. Surveillance of the extent and trends of antimicrobial resistance as well as the supply, selection and use of antimicrobial drugs should be established to monitor the process and outcome of containment of AMR. The ARCS approach is represented in the ARCS diagram (Fig. 2) which provides a simplified, but comprehensive illustration of the complex problem of containment and monitoring of AMR. PMID:15654407

Surgical and Antimicrobial Treatment of Prosthetic Vascular Graft Infections at Different Surgical Sites: A Retrospective Study of Treatment Outcomes

Science.gov (United States)

Elzi, Luigia; Gurke, Lorenz; Battegay, Manuel; Widmer, Andreas F.; Weisser, Maja

2014-01-01

Objective Little is known about optimal management of prosthetic vascular graft infections, which are a rare but serious complication associated with graft implants. The goal of this study was to compare and characterize these infections with respect to the location of the graft and to identify factors associated with outcome. Methods This was a retrospective study over more than a decade at a tertiary care university hospital that has an established multidisciplinary approach to treating graft infections. Cases of possible prosthetic vascular graft infection were identified from the hospital's infectious diseases database and evaluated against strict diagnostic criteria. Patients were divided into groups according to the locations of their grafts: thoracic-aortic, abdominal-aortic, or peripheral-arterial. Statistical analyses included evaluation of patient and infection characteristics, time to treatment failure, and factors associated specifically with cure rates in aortic graft infections. The primary endpoint was cure at one year after diagnosis of the infection. Results Characterization of graft infections according to the graft location did show that these infections differ in terms of their characteristics and that the prognosis for treatment seems to be influenced by the location of the infection. Cure rate and all-cause mortality at one year were 87.5% and 12.5% in 24 patients with thoracic-aortic graft infections, 37.0% and 55.6% in 27 patients with abdominal-aortic graft infections, and 70.0% and 30.0% in 10 patients with peripheral-arterial graft infections. In uni- and multivariate analysis, the type of surgical intervention used in managing infections (graft retention versus graft replacement) did not affect primary outcome, whereas a rifampicin-based antimicrobial regimen was associated with a higher cure rate. Conclusions We recommend that future prospective studies differentiate prosthetic vascular graft infections according to the location of the

Importance of antimicrobial stewardship to the English National Health Service

Directory of Open Access Journals (Sweden)

Dixon J

2014-05-01

priorities include establishing novel approaches to antimicrobial management (eg, duration of therapy, combination regimens to protect against resistance and working with the pharmaceutical industry to promote the development of new antimicrobials. Keywords: antimicrobial resistance, antibiotics, National Health Service, methicillin-resistant Staphylococcus aureus, Clostridium difficile, prescribing

Alternative Antimicrobial Approach: Nano-Antimicrobial Materials

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Nurit Beyth

2015-01-01

Full Text Available Despite numerous existing potent antibiotics and other antimicrobial means, bacterial infections are still a major cause of morbidity and mortality. Moreover, the need to develop additional bactericidal means has significantly increased due to the growing concern regarding multidrug-resistant bacterial strains and biofilm associated infections. Consequently, attention has been especially devoted to new and emerging nanoparticle-based materials in the field of antimicrobial chemotherapy. The present review discusses the activities of nanoparticles as an antimicrobial means, their mode of action, nanoparticle effect on drug-resistant bacteria, and the risks attendant on their use as antibacterial agents. Factors contributing to nanoparticle performance in the clinical setting, their unique properties, and mechanism of action as antibacterial agents are discussed in detail.

Increased Pathogen Identification in Vascular Graft Infections by the Combined Use of Tissue Cultures and 16S rRNA Gene Polymerase Chain Reaction

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Evelyne Ajdler-Schaeffler

2018-06-01

Full Text Available Background: Vascular graft infections (VGI are difficult to diagnose and treat, and despite redo surgery combined with antimicrobial treatment, outcomes are often poor. VGI diagnosis is based on a combination of clinical, radiological, laboratory and microbiological criteria. However, as many of the VGI patients are already under antimicrobial treatment at the time of redo surgery, microbiological identification is often difficult and bacterial cultures often remain negative rendering targeted treatment impossible. We aimed to assess the benefit of 16S rRNA gene polymerase chain reaction (broad-range PCR for better microbiological identification in patients with VGI.Methods: We prospectively analyzed the clinical, microbiological, and treatment data of patients enrolled in the observational Vascular Graft Cohort Study (VASGRA, University Hospital Zurich, Switzerland. The routine diagnostic work-up involved microbiological cultures of minced tissue samples, and the use of molecular techniques in parallel. Patient-related and microbiological data were assessed in descriptive analyses, and we calculated sensitivity, specificity, negative and positive predictive value for broad-range 16S rRNA gene PCR versus culture (considered as gold standard.Results: We investigated 60 patients (median age 66 years (Interquartile range [IQR] 59–75 with confirmed VGI between May 2013 and July 2017. The prevalence of antimicrobial pretreatment at the time of sampling was high [91%; median days of antibiotics 7 days (IQR 1–18]. We investigated 226 microbiological specimens. Thereof, 176 (78% were culture-negative and 50 (22% were culture-positive. There was a concordance of 70% (158/226 between conventional culture and broad-range PCR (sensitivity 58% (95% CI 43–72; specificity 74% (67–80%. Among the group of 176 culture-negative specimens, 46 specimens were broad-range PCR-positive resulting in identification of overall 69 species. Among the culture and

Antimicrobial activity of human prion protein is mediated by its N-terminal region.

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Mukesh Pasupuleti

Full Text Available BACKGROUND: Cellular prion-related protein (PrP(c is a cell-surface protein that is ubiquitously expressed in the human body. The multifunctionality of PrP(c, and presence of an exposed cationic and heparin-binding N-terminus, a feature characterizing many antimicrobial peptides, made us hypothesize that PrP(c could exert antimicrobial activity. METHODOLOGY AND PRINCIPAL FINDINGS: Intact recombinant PrP exerted antibacterial and antifungal effects at normal and low pH. Studies employing recombinant PrP and N- and C-terminally truncated variants, as well as overlapping peptide 20mers, demonstrated that the antimicrobial activity is mediated by the unstructured N-terminal part of the protein. Synthetic peptides of the N-terminus of PrP killed the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, and the Gram-positive Bacillus subtilis and Staphylococcus aureus, as well as the fungus Candida parapsilosis. Fluorescence studies of peptide-treated bacteria, paired with analysis of peptide effects on liposomes, showed that the peptides exerted membrane-breaking effects similar to those seen after treatment with the "classical" human antimicrobial peptide LL-37. In contrast to LL-37, however, no marked helix induction was detected for the PrP-derived peptides in presence of negatively charged (bacteria-mimicking liposomes. PrP furthermore showed an inducible expression during wounding of human skin ex vivo and in vivo, as well as stimulation of keratinocytes with TGF-alpha in vitro. CONCLUSIONS: The demonstration of an antimicrobial activity of PrP, localisation of its activity to the N-terminal and heparin-binding region, combined with results showing an increased expression of PrP during wounding, indicate that PrPs could have a previously undisclosed role in host defense.

Treatment of premature ejaculation: a new combined approach

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Adel Kurkar

2015-01-01

Causes of PE differ considerably. In this paper, we compared the outcomes of two single treatment lines together with a combination of both. The combination therapy was more effective than either line alone.

Solvent exchange-induced in situ forming gel comprising ethyl cellulose-antimicrobial drugs.

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Phaechamud, Thawatchai; Mahadlek, Jongjan

2015-10-15

Solvent-exchanged in situ forming gel is a drug delivery system which is in sol form before administration. When it contacts with the body fluid, then the water miscible organic solvent dissipates and water penetrates into the system, leading the polymer precipitation as in situ gel at the site of injection. The aim of this research was to study the parameters affecting the gel properties, drug release and antimicrobial activities of the in situ forming gels prepared from ethyl cellulose (EC) dissolved in N-methyl pyrrolidone (NMP) to deliver the antimicrobial agents (doxycycline hyclate, metronidazole and benzyl peroxide) for periodontitis treatment. The gel appearance, pH, viscosity, rheology, syringeability, gel formation, rate of water diffusion into the gels, in vitro degradation, drug release behavior and antimicrobial activities against Staphylococcus aureus, Escherichia coli, Candida albicans, Streptococcus mutans and Porphyrommonas gingivalis were determined. Increasing the amount of EC increased the viscosity of system while still exhibiting Newtonian flow and increased the work of syringeability whereas decreased the releasing of drug. The system transformed into the rigid gel formation after being injected into the simulated gingival crevicular fluid. The developed systems containing 5% w/w antimicrobial agent showed the antimicrobial activities against all test bacteria. Thus the developed solvent exchange-induced in situ forming gels comprising EC-antimicrobial drugs exhibited potential use for periodontitis treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

In vitro evaluation of the root canal cleaning ability of plant extracts and their antimicrobial action

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Edja Maria Melo de Brito Costa

2012-06-01

Full Text Available This in vitro study evaluated both the antimicrobial activity and the root canal cleaning ability of plant extracts used in irrigation solutions. The antimicrobial activities of the aroeira-da-praia (Schinus terebintifolius Raddi and the quixabeira (Syderoxylum obtusifolium Roem & Schult hydroalcoholic extracts, of 2.5% sodium hypochlorite (NaOCl and of 0.12% chlorhexidine (positive control against Enterococcus faecalis were tested with the agar well diffusion method. The level of root canal cleanliness was examined by scanning electron microscopy (SEM. Twenty one single-rooted human teeth were divided into three groups according to the irrigation solution applied: 1 50% aroeira-da-praia; 2 50% quixabeira and 3 a combination of 2.5% sodium hypochlorite + 17% EDTA. All solutions tested demonstrated antimicrobial activity against Enterococcus faecalis. The SEM analysis revealed that higher and lower degrees of surface cleaning were observed, in the three groups, respectively for the coronal and apical thirds, in that quixabeira showed the greatest efficiency in removing the smear layer in the apical third. All the agents tested presented antimicrobial activity against E. faecalis. None, however, was able to completely remove the smear layer of the dentinal surface in the different thirds of the root canal. The results suggest that the analyzed plant extracts may represent a new therapeutic option in the list of alternative agents available for endodontic treatment.

Chitosan based metallic nanocomposite scaffolds as antimicrobial wound dressings.

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Mohandas, Annapoorna; Deepthi, S; Biswas, Raja; Jayakumar, R

2018-09-01

Chitosan based nanocomposite scaffolds have attracted wider applications in medicine, in the area of drug delivery, tissue engineering and wound healing. Chitosan matrix incorporated with nanometallic components has immense potential in the area of wound dressings due to its antimicrobial properties. This review focuses on the different combinations of Chitosan metal nanocomposites such as Chitosan/nAg, Chitosan/nAu, Chitosan/nCu, Chitosan/nZnO and Chitosan/nTiO 2 towards enhancement of healing or infection control with special reference to the antimicrobial mechanism of action and toxicity.

NATURAL ANTIMICROBIAL AGENT USE IN THE PRESERVATION OF FRUITS AND VEGETABLES

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Elvia Nereyda Rodríguez Sauceda

2011-01-01

Full Text Available Today has been a need to find alternatives of conservation, because it has been associated with consumption of poison chemical preservatives. The demand for minimally processed fresh products is increasing, and interest in natural antimicrobial agents (derived from plants, so now looking for the combination of two or more factors that interact additively or synergistically controlling population microbial, allowing it to fresh produce similar products with less additives, it should be noted that the rate of microbial spoilage depends not only on microorganisms but also the chemical combination of product and type of initial microbial load. That is why the main aim of food processing is to provide comfort to humans through a safe, nutritionally adequate and meet the expectations of taste, aroma and appearance, so the use of natural food additives involves the isolation, purification, stabilization and incorporation of these compounds to food antimicrobial purposes, without adversely affecting the sensory characteristics. In general, every time we discover more plants or parts thereof which contain natural antimicrobials, such as including phenolic compounds from bark, stems, leaves, flowers, organic acids present in fruits and phytoalexins produced in plants, so as will not only safer, but better food quality and type of antimicrobials that are regarded as potentially safer sources.

Combinations of drugs in the Treatment of Obesity

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Marcio C. Mancini

2010-07-01

Full Text Available Obesity is a chronic disease associated with excess morbidity and mortality. Clinical treatment, however, currently offers disappointing results, with very high rates of weight loss failure or weight regain cycles, and only two drugs (orlistat and sibutramine approved for long-term use. Drugs combinations can be an option for its treatment but, although widely used in clinical practice, very few data are available in literature for its validation. Our review focuses on the rationale for their use, with advantages and disadvantages; on combinations often used, with or without studies; and on new perspectives of combinations being studied mainly by the pharmaceutical industry.

Silica-Gentamicin Nanohybrids: Synthesis and Antimicrobial Action

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Dina Ahmed Mosselhy

2016-03-01

Full Text Available Orthopedic applications commonly require the administration of systemic antibiotics. Gentamicin is one of the most commonly used aminoglycosides in the treatment and prophylaxis of infections associated with orthopedic applications, but gentamicin has a short half-life. However, silica nanoparticles (SiO2 NPs can be used as elegant carriers for antibiotics to prolong their release. Our goal is the preparation and characterization of SiO2-gentamicin nanohybrids for their potential antimicrobial administration in orthopedic applications. In vitro gentamicin release profile from the nanohybrids (gentamicin-conjugated SiO2 NPs prepared by the base-catalyzed precipitation exhibited fast release (21.4% during the first 24 h and further extension with 43.9% release during the five-day experiment. Antimicrobial studies of the SiO2-gentamicin nanohybrids versus native SiO2 NPs and free gentamicin were performed against Bacillus subtilis (B. subtilis, Pseudomonas fluorescens (P. fluorescens and Escherichia coli (E. coli. SiO2-gentamicin nanohybrids were most effective against B. subtilis. SiO2 NPs play no antimicrobial role. Parallel antimicrobial studies for the filter-sterilized gentamicin were performed to assess the effect of ultraviolet (UV-irradiation on gentamicin. In summary, the initial fast gentamicin release fits the need for high concentration of antibiotics after orthopedic surgical interventions. Moreover, the extended release justifies the promising antimicrobial administration of the nanohybrids in bone applications.

Antimicrobial-impregnated dressing combined with negative-pressure wound therapy increases split-thickness skin graft engraftment: a simple effective technique.

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Wu, Cheng-Chun; Chew, Khong-Yik; Chen, Chien-Chang; Kuo, Yur-Ren

2015-01-01

Immobilization and adequate surface contact to wounds are critical for skin graft take. Techniques such as the tie-over dressing, cotton bolster, and vacuum-assisted closure are used to address this, but each has its limitations. This study is designed to assess the effect of antimicrobial-impregnated dressing (AMD) combined with negative-pressure wound therapy (NPWT) on skin graft survival. Retrospective case-control study : Patients with chronic or contaminated wounds treated with split-thickness skin graft. A broad spectrum of wounds was included, from causes such as trauma, burns, chronic diabetic ulcers, and infection. Antimicrobial-impregnated dressing, which contains 0.2% polyhexamethylene biguanide, with NPWT MAIN OUTCOME MEASURE:: Success of skin graft : In the AMD group, all skin grafts achieved 100% take without secondary intervention. No infection or graft failure was observed in any patients, and no complications, such as hematoma or seroma formation, were noted, although in the control group partial loss of skin grafts was noted in 3 patients. Infection and inadequate immobilization were thought to be the main reasons. There were no hematoma or seroma formations in the control group. Use of an AMD dressing with NPWT after split-thickness skin grafting can be an effective method to ensure good graft to wound contact and enhances skin graft take in chronic and contaminated wounds.

Characterization of shallot, an antimicrobial extract of allium ascalonicum

International Nuclear Information System (INIS)

Amin, M.; Montazeri, E.A.; Mashhadizadeh, M.A.; Sheikh, A.F.

2009-01-01

Objective: The objective of this study was characterization of antimicrobial extract of shallot in terms of its stability at different pH, Heat, enzymes and detergents and also determination of its MIC and shelf life. Methodology: Active fraction was determined by column chromatography and agar diffusion test. The amount of carbohydrate and protein in different forms of shallot extract were estimated. Stability of antimicrobial activity of shallot extract at different pH and temperature, solubility in different solvent, determination of shelf life and susceptibility to enzymes and detergents were evaluated. Results: Shallot extract was active against microbes at pH 4-8. Relative activities of shallot extract at temperature -7 to 121 deg. C were 88 to 100 %. Extract of shallot only was soluble in dimethyl sulphoxide, dimethyl formamide and water. The enzymes and detergents used in this study had no effect on antimicrobial activity on water extract of shallot. Relative antimicrobial activity at incubation times of one hour to 6 mounts were 94 to 100 %. Conclusion: In this study antimicrobial properties of shallot were investigated for discovery of a new antibiotic. Based on this the antimicrobial compound can be an effective medicine for treatment of dermatomycosis and other infectious diseases. (author)

Alternative Antimicrobial Approach: Nano-Antimicrobial Materials

OpenAIRE

Nurit Beyth; Yael Houri-Haddad; Avi Domb; Wahid Khan; Ronen Hazan

2015-01-01

Despite numerous existing potent antibiotics and other antimicrobial means, bacterial infections are still a major cause of morbidity and mortality. Moreover, the need to develop additional bactericidal means has significantly increased due to the growing concern regarding multidrug-resistant bacterial strains and biofilm associated infections. Consequently, attention has been especially devoted to new and emerging nanoparticle-based materials in the field of antimicrobial chemotherapy. The ...

Application of Nanofibrillated Cellulose on BOPP/LDPE Film as Oxygen Barrier and Antimicrobial Coating Based on Cold Plasma Treatment

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Peng Lu

2018-05-01

Full Text Available The application of nanofibrillated cellulose (NC films in packaging industry has been hindered by its lack of heat-sealing ability. Incorporation of NC films with the biaxially oriented polypropylene/low density polyethylene (BOPP/LDPE laminates can take advantage of each material and endow the films with novel functions for food packaging applications. In this study, a coating that consists of NC and nisin was applied onto a cold plasma treated BOPP/LDPE film to fabricate a novel active packaging with an improved oxygen barrier performance and an added antimicrobial effect. The results showed that cold plasma treatment improved the surface hydrophilicity of BOPP/LDPE films for better attachment of the coatings. NC coatings significantly enhanced oxygen barrier property of the BOPP/LDPE film, with an oxygen transmission rate as low as 24.02 cc/m2·day as compared to that of the non-coated one (67.03 cc/m2·day. The addition of nisin in the coating at a concentration of 5 mg/g caused no significant change in barrier properties but imparted the film excellent antimicrobial properties, with a growth inhibition of L. monocytogenes by 94%. All films exhibit satisfying mechanical properties and transparency, and this new film has the potential to be used as antimicrobial and oxygen barrier packaging.

Impetigo: A need for new therapies in a world of increasing antimicrobial resistance.

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D'Cunha, N M; Peterson, G M; Baby, K E; Thomas, J

2018-02-01

Impetigo is a highly contagious bacterial skin infection and is one of the most common skin infections in children. Antibiotics are the first-line treatment when multiple lesions exist, but with an increasing prevalence of antibiotic-resistant bacteria the successful management of impetigo in the future is an area of concern. Current treatment options that favour the use of oral antibiotic therapy are increasingly problematic. Widespread use of these agents contributes to antimicrobial resistance and has adverse consequences for individuals and communities. There is a need for new topical antimicrobials and antiseptics as an alternative treatment strategy. To successfully treat impetigo into the future and ensure that therapy does not contribute to bacterial resistance, additional research is required to ascertain the usefulness of alternative agents, including new topical antimicrobials and antiseptics. © 2017 John Wiley & Sons Ltd.

Antimicrobial Effects of 7,8-Dihydroxy-6-Methoxycoumarin and 7-Hydroxy-6-Methoxycoumarin Analogues against Foodborne Pathogens and the Antimicrobial Mechanisms Associated with Membrane Permeability.

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Yang, Ji-Yeon; Park, Jun-Hwan; Lee, Myung-Ji; Lee, Ji-Hoon; Lee, Hoi-Seon

2017-10-03

The antimicrobial effects of 7,8-dihydroxy-6-methoxycoumarin and 7-hydroxy-6-methoxycoumarin isolated from Fraxinus rhynchophylla bark and of their structural analogues were determined in an attempt to develop natural antimicrobial agents against the foodborne pathogens Escherichia coli, Bacillus cereus, Staphylococcus intermedius, and Listeria monocytogenes. To elucidate the relationship between structure and antimicrobial activity for the coumarin analogues, isolated constituents and their structural analogues were evaluated against foodborne pathogens. Based on the culture plate inhibition zones and MICs, 6,7-dimethoxycoumarin, 7,8-dihydroxy-6-methoxycoumarin, 7-hydroxy-6-methoxycoumarin, and 7-methoxycoumarin, containing a methoxy functional group on the coumarin skeleton, had the notable antimicrobial activity against foodborne pathogens. However, 7-hydroxycoumarin and 6,7-dihydroxycoumarin, which contained a hydroxyl functional group on the coumarin skeleton, had no antimicrobial activity against these pathogens. An increase in cell membrane permeability was confirmed by electron microscopy observations, and release of extracellular ATP and cell constituents followed treatment with the ethyl acetate fraction of F. rhynchophylla extract. These findings indicate that F. rhynchophylla extract and coumarin analogues have potential for use as antimicrobial agents against foodborne pathogens and that the antimicrobial mechanisms are associated with the loss of cell membrane integrity.

Biosynthesis, characterization and antimicrobial study of silver ...

African Journals Online (AJOL)

Both the characterization and antimicrobial activity test were very successful and could lead to significant economic viability, as well as being environmentally friendly for treatment of some infectious diseases. Keywords: Syzygium guineenses, Green Chemistry, Spectroscopy, Optoelectronics, Biomedical Sensors ...

Sewage sludge disintegration by combined treatment of alkaline+high pressure homogenization.

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Zhang, Yuxuan; Zhang, Panyue; Zhang, Guangming; Ma, Weifang; Wu, Hao; Ma, Boqiang

2012-11-01

Alkaline pretreatment combined with high pressure homogenization (HPH) was applied to promote sewage sludge disintegration. For sewage sludge with a total solid content of 1.82%, sludge disintegration degree (DD(COD)) with combined treatment was higher than the sum of DD(COD) with single alkaline and single HPH treatment. NaOH dosage ⩽0.04mol/L, homogenization pressure ⩽60MPa and a single homogenization cycle were the suitable conditions for combined sludge treatment. The combined sludge treatment showed a maximum DD(COD) of 59.26%. By regression analysis, the combined sludge disintegration model was established as 11-DD(COD)=0.713C(0.334)P(0.234)N(0.119), showing that the effect of operating parameters on sludge disintegration followed the order: NaOH dosage>homogenization pressure>number of homogenization cycle. The energy efficiency with combined sludge treatment significantly increased compared with that with single HPH treatment, and the high energy efficiency was achieved at low homogenization pressure with a single homogenization cycle. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of antimicrobial compounds tylosin and chlortetracycline during batch anaerobic swine manure digestion.

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Stone, James J; Clay, Sharon A; Zhu, Zhenwei; Wong, Kwok L; Porath, Laura R; Spellman, Garth M

2009-10-01

Tylosin and chlortetracycline (CTC) are antimicrobial chemicals that are fed to >45% of the US swine herds at therapeutic and sub-therapeutic dosages to enhance growth rates and treat swine health problems. These compounds are poorly absorbed during digestion so that the bioactive compound or metabolites are excreted. This study investigated the degradation and stabilization of swine manure that contained no additives and compared the observed processes with those of manure containing either tylosin or CTC. The batch anaerobic incubation lasted 216 days. The breakdown of insoluble organic matter through anaerobic hydrolysis reactions was faster for manure containing CTC compared with tylosin or no-antimicrobial treatments. Volatile fatty acid (VFA) accumulation, including acetate, butyrate, and propionate, was greater for CTC-containing manure compared to tylosin and no-antimicrobial treatments. The relative abundance of two aceticlastic methanogens, Methanosaetaceae and Methanosarcinaceae spp., were less for CTC manure than manure with no-antimicrobial treatment. In addition, generation of methane and carbon dioxide was inhibited by 27.8% and 28.4%, respectively, due to the presence of CTC. Tylosin effects on manure degradation were limited, however the relative abundance of Methanosarcinaceae spp. was greater than found in the CTC or no-antimicrobial manures. These data suggest that acetate and other C-1 VFA compounds would be effectively utilized during methanogenesis in the presence of tylosin.

Antimicrobial topical agents used in the vagina.

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Frey Tirri, Brigitte

2011-01-01

Vaginally applied antimicrobial agents are widely used in the vagina in women with lower genital tract infections. An 'antimicrobial' is a general term that refers to a group of drugs that are effective against bacteria, fungi, viruses and protozoa. Topical treatments can be prescribed for a wide variety of vaginal infections. Many bacterial infections, such as bacterial vaginosis, desquamative inflammatory vaginitis or, as some European authors call it, aerobic vaginitis as well as infection with Staphylococcus aureus or group A streptococci, may be treated in this way. Candida vulvovaginitis is a fungal infection that is very amenable to topical treatment. The most common viral infections which can be treated with topical medications are condylomata acuminata and herpes simplex. The most often encountered protozoal vaginitis, which is caused by Trichomonas vaginalis, may be susceptible to topical medications, although this infection is treated systemically. This chapter covers the wide variety of commonly used topical antimicrobial agents for these diseases and focuses on the individual therapeutic agents and their clinical efficacy. In addition, potential difficulties that can occur in practice, as well as the usage of these medications in the special setting of pregnancy, are described in this chapter. Copyright © 2011 S. Karger AG, Basel.

The combined use of virtual reality exposure in the treatment of agoraphobia.

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Pitti, Carmen T; Peñate, Wenceslao; de la Fuente, Juan; Bethencourt, Juan M; Roca-Sánchez, María J; Acosta, Leopoldo; Villaverde, María L; Gracia, Ramón

2015-01-01

This study compares the differential efficacy of three groups of treatments for agoraphobia: paroxetine combined with cognitive-behavioral therapy, paroxetine combined with cognitive-behavioral therapy and virtual reality exposure, and a group with only paroxetine. 99 patients with agoraphobia were finally selected. Both combined treatment groups received 11 sessions of cognitive-behavioral therapy, and one of the groups was also exposed to 4 sessions of virtual reality treatment. Treatments were applied in individual sessions once a week for 3 months. The three treatment groups showed statistically significant improvements. In some measures, combined treatment groups showed greater improvements. The virtual reality exposure group showed greater improvement confronting phobic stimuli. Treatments combining psychopharmacological and psychological therapy showed greater efficacy. Although the use of new technologies led to greater improvement, treatment adherence problems still remain.

Antimicrobial susceptibility of Brachyspira hyodysenteriae in Switzerland.

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Kirchgässner, C; Schmitt, S; Borgström, A; Wittenbrink, M M

2016-06-01

Brachyspira (B.) hyodysenteriae is the causative agent of swine dysentery (SD), a severe mucohaemorrhagic diarrheal disease in pigs worldwide. So far, the antimicrobial susceptibility patterns of B. hyodysenteriae in Switzerland have not been investigated. Therefore, a panel of 30 porcine B. hyodysenteriae isolates were tested against 6 antimicrobial agents by using the VetMIC Brachy panel, a broth microdilution test. Tiamulin and valnemulin showed high antimicrobial activity inhibiting all isolates at low concentrations. The susceptibility testing of doxycycline revealed values from ≤0.25 μg/ ml (47%) to 2 μg/ml (10%). The MIC values of lincomycin ranged between ≤0.5 μg/ml (30%) and 32 μg/ml (43%). For tylosin, 57% of the isolates could not be inhibited at the highest concentration of ≥128 μg/ml. The MIC values for tylvalosin were between ≤0.25 μg/ml (10%) and 8 μg/ml (20%). These findings reveal Switzerland's favourable situation compared to other European countries. Above all, tiamulin and valnemulin are still effective antimicrobial agents and can be further used for the treatment of SD.

Antimicrobial photodynamic therapy combined with periodontal treatment for metabolic control in patients with type 2 diabetes mellitus: study protocol for a randomized controlled trial.

Science.gov (United States)

Evangelista, Erika Elisabeth; França, Cristiane Miranda; Veni, Priscila; de Oliveira Silva, Tamires; Gonçalves, Rafael Moredo; de Carvalho, Verônica Franco; Deana, Alessandro Melo; Fernandes, Kristianne P S; Mesquita-Ferrari, Raquel A; Camacho, Cleber P; Bussadori, Sandra Kalil; Alvarenga, Letícia Heineck; Prates, Renato Araujo

2015-05-27

The relationship between diabetes mellitus (DM) and periodontal disease is bidirectional. DM is a predisposing and modifying factor of periodontitis, which, in turn, worsens glycemic control and increases proteins found in the acute phase of inflammation, such as C-reactive protein. The gold standard for the treatment of periodontal disease is oral hygiene orientation, scaling and planing. Moreover, systemic antibiotic therapy may be employed in some cases. In an effort to minimize the prescription of antibiotics, photodynamic therapy (PDT) has been studied as an antimicrobial technique and has demonstrated promising results. The aim of the proposed study is to determine whether PDT as a complement to periodontal therapy (PT) is helpful in the metabolic control of individuals with type 2 diabetes and the reduction of acute-phase inflammatory markers. The patients will be randomized using a proper software program into two groups: 1) PT + placebo PDT or 2) PT + active PDT. All patients will first be examined by a specialist, followed by PT performed by two other healthcare professionals. At the end of each session, PDT (active or placebo) will be administered by a fourth healthcare professional. The following will be the PDT parameters: diode laser (660 nm); power output = 110 mW; exposure time = 90 s per point (9 J/point); and energy density = 22 J/cm(2). The photosensitizer will be methylene blue (50 μg/mL). The patients will be re-evaluated 15, 30, 90 and 180 days after treatment. Serological examinations with complete blood count, fasting glucose, glycated hemoglobin and salivary examinations to screen for tumor necrosis factor alpha, interleukin 1, interleukin 6, ostelocalcin, and osteoprotegerin/RANKL will be performed at each evaluation. The data will be statistically evaluated using the most appropriate tests. The results of this study will determine the efficacy of photodynamic therapy as an adjuvant to periodontal treatment in diabetic patients. The